[packet_interface] Add session and XXTEA encryption layers (#21088)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

CODEOWNERS

@@ -697,6 +697,7 @@ esphome/components/uart/packet_transport/* @clydebarrow
 esphome/components/uart_mux/* @kbx81
 esphome/components/uart_tcp/* @Bascht74
 esphome/components/udp/* @clydebarrow
+esphome/components/udp/packet_interface/* @clydebarrow
 esphome/components/ufire_ec/* @pvizeli
 esphome/components/ufire_ise/* @pvizeli
 esphome/components/ufm01/* @ljungqvist

esphome/components/as7341/as7341.cpp

@@ -110,12 +110,12 @@ bool AS7341Component::read_channels(uint16_t *data) {
   this->set_smux_low_channels(true);
   this->enable_spectral_measurement(true);
   this->wait_for_data();
-  bool low_success = this->read_bytes_16(AS7341_CH0_DATA_L, data, 6);
+  bool low_success = this->read_bytes_16_le(AS7341_CH0_DATA_L, data, 6);
 
   this->set_smux_low_channels(false);
   this->enable_spectral_measurement(true);
   this->wait_for_data();
-  bool high_sucess = this->read_bytes_16(AS7341_CH0_DATA_L, &data[6], 6);
+  bool high_sucess = this->read_bytes_16_le(AS7341_CH0_DATA_L, &data[6], 6);
 
   return low_success && high_sucess;
 }

esphome/components/const/__init__.py

@@ -19,6 +19,7 @@ CONF_BITRATE = "bitrate"
 CONF_BLUE_CHANNEL = "blue_channel"
 CONF_BORDER_ROUTER = "border_router"
 CONF_BREATH_VOC_EQUIVALENT = "breath_voc_equivalent"
+CONF_BUTTONS = "buttons"
 CONF_BYTE_ORDER = "byte_order"
 CONF_CHANNEL_COLORS = "channel_colors"
 CONF_CLEAR_CHANNEL = "clear_channel"

esphome/components/demo/__init__.py

@@ -18,6 +18,7 @@ from esphome.components import (
     text_sensor,
     valve,
 )
+from esphome.components.const import CONF_BUTTONS
 import esphome.config_validation as cv
 from esphome.const import (
     CONF_ACCURACY_DECIMALS,
@@ -167,7 +168,6 @@ VALVE_TYPES = {
 
 
 CONF_ALARM_CONTROL_PANELS = "alarm_control_panels"
-CONF_BUTTONS = "buttons"
 CONF_CLIMATES = "climates"
 CONF_COVERS = "covers"
 CONF_DATETIMES = "datetimes"

esphome/components/http_request/__init__.py

@@ -56,6 +56,7 @@ CONF_HTTP_REQUEST_ID = "http_request_id"
 CONF_USERAGENT = "useragent"
 CONF_FOLLOW_REDIRECTS = "follow_redirects"
 CONF_REDIRECT_LIMIT = "redirect_limit"
+CONF_MAX_CONCURRENT_REQUESTS = "max_concurrent_requests"
 CONF_BUFFER_SIZE_RX = "buffer_size_rx"
 CONF_BUFFER_SIZE_TX = "buffer_size_tx"
 CONF_TLS_BUFFER_SIZE_RX = "tls_buffer_size_rx"
@@ -144,6 +145,10 @@ CONFIG_SCHEMA = cv.All(
             ): cv.string,
             cv.Optional(CONF_FOLLOW_REDIRECTS, True): cv.boolean,
             cv.Optional(CONF_REDIRECT_LIMIT, 3): cv.int_,
+            # Each request holds a client, and a TLS client about 40 kB
+            cv.Optional(CONF_MAX_CONCURRENT_REQUESTS, default=1): cv.int_range(
+                min=1, max=4
+            ),
             cv.Optional(
                 CONF_TIMEOUT, default="4.5s"
             ): cv.positive_time_period_milliseconds,
@@ -193,6 +198,8 @@ async def to_code(config: ConfigType) -> None:
     cg.add(var.set_useragent(config[CONF_USERAGENT]))
     cg.add(var.set_follow_redirects(config[CONF_FOLLOW_REDIRECTS]))
     cg.add(var.set_redirect_limit(config[CONF_REDIRECT_LIMIT]))
+    if (max_concurrent := config[CONF_MAX_CONCURRENT_REQUESTS]) != 1:
+        cg.add(var.set_max_concurrent_requests(max_concurrent))
 
     if CORE.is_esp8266 and not config[CONF_ESP8266_DISABLE_SSL_SUPPORT]:
         cg.add_define("USE_HTTP_REQUEST_ESP8266_HTTPS")
@@ -312,19 +319,19 @@ HTTP_REQUEST_SEND_ACTION_SCHEMA = HTTP_REQUEST_ACTION_SCHEMA.extend(
     "http_request.get",
     HttpRequestSendAction,
     HTTP_REQUEST_GET_ACTION_SCHEMA,
-    synchronous=True,
+    synchronous=False,
 )
 @automation.register_action(
     "http_request.post",
     HttpRequestSendAction,
     HTTP_REQUEST_POST_ACTION_SCHEMA,
-    synchronous=True,
+    synchronous=False,
 )
 @automation.register_action(
     "http_request.send",
     HttpRequestSendAction,
     HTTP_REQUEST_SEND_ACTION_SCHEMA,
-    synchronous=True,
+    synchronous=False,
 )
 async def http_request_action_to_code(
     config: ConfigType,

esphome/components/http_request/http_request.cpp

@@ -1,5 +1,7 @@
 #include "http_request.h"
 
+#include "esphome/core/application.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 
 #include <cinttypes>
@@ -14,8 +16,10 @@ void HttpRequestComponent::dump_config() {
                 "  Timeout: %" PRIu32 "ms\n"
                 "  User-Agent: %s\n"
                 "  Follow redirects: %s\n"
-                "  Redirect limit: %d",
-                this->timeout_, this->useragent_, YESNO(this->follow_redirects_), this->redirect_limit_);
+                "  Redirect limit: %d\n"
+                "  Max concurrent requests: %u",
+                this->timeout_, this->useragent_, YESNO(this->follow_redirects_), this->redirect_limit_,
+                this->max_concurrent_);
   if (this->watchdog_timeout_ > 0) {
     ESP_LOGCONFIG(TAG, "  Watchdog Timeout: %" PRIu32 "ms", this->watchdog_timeout_);
   }
@@ -32,4 +36,209 @@ std::string HttpContainer::get_response_header(const std::string &header_name) {
   return "";
 }
 
+void PendingRequest::free_buffer() {
+  if (this->buf != nullptr)
+    RAMAllocator<uint8_t>().deallocate(this->buf, this->buf_size);
+  this->buf = nullptr;
+}
+
+void HttpRequestComponent::setup() {
+  // An on_boot automation may already have queued a request
+  if (this->requests_ == nullptr)
+    this->disable_loop();
+}
+
+void HttpRequestComponent::loop() {
+  if (!this->process_())
+    this->disable_loop();
+}
+
+void HttpRequestComponent::on_safe_shutdown() {
+  // Called before any on_shutdown(). Drop the requests already made, so that they do not hold up the reboot;
+  // only the ones that on_shutdown automations make are sent.
+  this->shutting_down_ = true;
+  this->busy_++;
+  unsigned dropped = 0;
+  for (PendingRequest *request = this->requests_; request != nullptr; request = request->next) {
+    if (request->finished || request->cancelled)
+      continue;
+    dropped++;
+    request->cancelled = true;
+    // As script.stop would, so that a script that was waiting for it can run again from on_shutdown
+    request->handler(request, RequestEvent::REQUEST_EVENT_ABANDON);
+  }
+  this->busy_--;
+  if (dropped != 0) {
+    ESP_LOGW(TAG, "Shutting down; %u requests dropped", dropped);
+  }
+  if (this->busy_ == 0)
+    this->remove_dead_();
+}
+
+void HttpRequestComponent::on_shutdown() {
+  // Shutdown runs no loop(), so finish the requests here, blocking as they did before. A forced reboot calls
+  // only this, so it also finishes the requests made before it.
+  this->shutting_down_ = true;
+  this->drain_();
+}
+
+void HttpRequestComponent::submit(PendingRequest *request) {
+  this->busy_++;
+  uint8_t running = 0;
+  uint8_t waiting = 0;
+  PendingRequest **link = &this->requests_;
+  for (; *link != nullptr; link = &(*link)->next) {
+    const PendingRequest *other = *link;
+    if (other->finished || other->cancelled)
+      continue;
+    if (other->container == nullptr) {
+      waiting++;
+    } else {
+      running++;
+    }
+  }
+  *link = request;
+  this->enable_loop();
+  if (waiting >= MAX_QUEUED) {
+    ESP_LOGW(TAG, "Too many requests waiting; request dropped");
+    request->failed = true;
+    this->finish_(request);
+  } else if (waiting == 0 && running < this->max_concurrent_) {
+    // Start at once; one that cannot start is reported at once
+    this->begin_request_(request);
+    if (request->failed)
+      this->finish_(request);
+  }
+  this->busy_--;
+  if (this->busy_ != 0)
+    return;
+  if (this->shutting_down_) {
+    this->drain_();
+  } else {
+    this->remove_dead_();
+  }
+}
+
+void HttpRequestComponent::cancel(void *owner) {
+  for (PendingRequest *request = this->requests_; request != nullptr; request = request->next) {
+    if (request->owner == owner)
+      request->cancelled = true;
+  }
+  if (this->busy_ == 0)
+    this->remove_dead_();
+}
+
+bool HttpRequestComponent::process_() {
+  this->busy_++;
+  // The first max_concurrent_ live requests run; a request finished here frees its slot on the next pass
+  uint8_t slots = this->max_concurrent_;
+  for (PendingRequest *request = this->requests_; request != nullptr && slots != 0; request = request->next) {
+    if (request->finished || request->cancelled)
+      continue;
+    slots--;
+    if (request->container == nullptr)
+      this->begin_request_(request);
+    if (!request->cancelled && (request->failed || this->advance_(request)))
+      this->finish_(request);
+  }
+  this->busy_--;
+  if (this->busy_ == 0)
+    this->remove_dead_();
+  return this->requests_ != nullptr;
+}
+
+void HttpRequestComponent::drain_() {
+  // A call further up holds request pointers, and runs the new requests itself
+  if (this->busy_ != 0)
+    return;
+  while (this->process_()) {
+    App.feed_wdt();
+    delay(1);
+  }
+}
+
+void HttpRequestComponent::begin_request_(PendingRequest *request) {
+  request->start_time = millis();
+  request->handler(request, RequestEvent::REQUEST_EVENT_START);
+  // Stopped from the request's own lambdas: it is removed without being polled
+  if (!request->cancelled && request->container == nullptr)
+    request->failed = true;
+}
+
+bool HttpRequestComponent::advance_(PendingRequest *request) {
+  if (!request->reading) {
+    auto progress = request->container->poll();
+    if (progress == HttpRequestProgress::HTTP_REQUEST_PROGRESS_PENDING)
+      return false;
+    if (progress == HttpRequestProgress::HTTP_REQUEST_PROGRESS_FAILED) {
+      request->failed = true;
+      return true;
+    }
+    if (!request->capture)
+      return true;
+    request->buf = RAMAllocator<uint8_t>().allocate(request->buf_size);
+    if (request->buf == nullptr) {
+      // As before, on_response still fires, with an empty body
+      ESP_LOGW(TAG, "Could not allocate %zu bytes for the response body", request->buf_size);
+      return true;
+    }
+    request->reading = true;
+    // millis(), not the loop time: poll() may have blocked earlier in this pass
+    request->last_data_time = millis();
+  }
+  // NOTE: HttpContainer::read() has non-BSD socket semantics - see http_request.h
+  // millis(), not the loop time: the budget is shorter than one pass of the loop
+  const uint32_t start = millis();
+  while (request->read_index < request->buf_size) {
+    int read_or_error =
+        request->container->read_available(request->buf + request->read_index, request->buf_size - request->read_index);
+    const uint32_t now = millis();
+    // As before, a body that is cut off still fires on_response with what was read
+    if (read_or_error < 0) {
+      ESP_LOGW(TAG, "Response body read failed after %zu bytes", request->read_index);
+      return true;
+    }
+    if (read_or_error == 0) {
+      if (request->container->is_read_complete())
+        return true;
+      if (now - request->last_data_time < request->timeout)
+        return false;
+      ESP_LOGW(TAG, "Response body timed out after %zu bytes", request->read_index);
+      return true;
+    }
+    request->read_index += read_or_error;
+    request->last_data_time = now;
+    if (now - start >= READ_BUDGET_MS)
+      return false;
+  }
+  // As before, on_response still fires, with the part that fitted
+  if (!request->container->is_read_complete()) {
+    ESP_LOGW(TAG, "Response body is larger than max_response_buffer_size; kept the first %zu bytes", request->buf_size);
+  }
+  return true;
+}
+
+void HttpRequestComponent::finish_(PendingRequest *request) {
+  request->finished = true;
+  // The body was read over several passes, so time it from the start, as a blocking read would
+  if (request->reading && request->container != nullptr)
+    request->container->duration_ms = millis() - request->start_time;
+  request->handler(request, RequestEvent::REQUEST_EVENT_FINISH);
+}
+
+void HttpRequestComponent::remove_dead_() {
+  PendingRequest **link = &this->requests_;
+  while (PendingRequest *request = *link) {
+    if (!request->finished && !request->cancelled) {
+      link = &request->next;
+      continue;
+    }
+    *link = request->next;
+    if (request->container != nullptr)
+      request->container->end();
+    request->free_buffer();
+    request->handler(request, RequestEvent::REQUEST_EVENT_DESTROY);
+  }
+}
+
 }  // namespace esphome::http_request

esphome/components/http_request/http_request.h

@@ -12,6 +12,7 @@
 #include "esphome/core/component.h"
 #include "esphome/core/defines.h"
 #include "esphome/core/alloc_helpers.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
@@ -186,6 +187,13 @@ enum class HttpReadLoopResult : uint8_t {
   TIMEOUT,   ///< Timeout waiting for data, caller should exit loop
 };
 
+/// Progress of a request started with HttpRequestComponent::begin()
+enum class HttpRequestProgress : uint8_t {
+  HTTP_REQUEST_PROGRESS_PENDING,  ///< Still connecting, sending, or waiting for the response headers
+  HTTP_REQUEST_PROGRESS_DONE,     ///< Response headers received; status_code is set and the body can be read
+  HTTP_REQUEST_PROGRESS_FAILED,   ///< No response; the container must still be ended
+};
+
 /// Process a read result with timeout tracking and delay handling
 /// @param bytes_read_or_error Return value from read() - positive for bytes read, negative for error
 /// @param last_data_time Time of last successful read, updated when data received
@@ -249,8 +257,15 @@ class HttpContainer : public Parented<HttpRequestComponent> {
    *   - http_read_fully(): for simple "read N bytes" operations
    */
   virtual int read(uint8_t *buf, size_t max_len) = 0;
+  /// Like read(), but returns 0 at once when no data has arrived yet, where read() may wait for it.
+  virtual int read_available(uint8_t *buf, size_t max_len) { return this->read(buf, max_len); }
   virtual void end() = 0;
 
+  /// Advance a request started with HttpRequestComponent::begin(); call from the main loop until it is no
+  /// longer pending. Containers from start() are already done. Most calls return quickly, but on ESP-IDF the
+  /// first call for each host waits for the name lookup and the TCP connection, up to the whole timeout.
+  virtual HttpRequestProgress poll() { return HttpRequestProgress::HTTP_REQUEST_PROGRESS_DONE; }
+
   void set_secure(bool secure) { this->secure_ = secure; }
   void set_watchdog_timeout(uint32_t watchdog_timeout) { this->watchdog_timeout_ = watchdog_timeout; }
   uint32_t get_watchdog_timeout() const { return this->watchdog_timeout_; }
@@ -332,10 +347,56 @@ class HttpRequestResponseTrigger final : public Trigger<std::shared_ptr<HttpCont
   }
 };
 
+/// What HttpRequestComponent asks of the action that owns a request
+enum class RequestEvent : uint8_t {
+  REQUEST_EVENT_START,    ///< Build the request and call begin()
+  REQUEST_EVENT_FINISH,   ///< Fire the triggers and continue the action chain
+  REQUEST_EVENT_DESTROY,  ///< Free the request
+  REQUEST_EVENT_ABANDON,  ///< Dropped at shutdown: stop the action, so that it can run again
+};
+
+/// A request from an HttpRequestSendAction, run from HttpRequestComponent::loop().
+/// The action derives from it to add the trigger arguments.
+struct PendingRequest {
+  using Handler = void (*)(PendingRequest *request, RequestEvent event);
+  PendingRequest(Handler handler, void *owner) : handler(handler), owner(owner) {}
+  PendingRequest(const PendingRequest &) = delete;
+  PendingRequest &operator=(const PendingRequest &) = delete;
+  void free_buffer();
+
+  PendingRequest *next{nullptr};
+  Handler handler;
+  // The action, so that a stop of it can find its requests
+  void *owner;
+  // nullptr until the request has started
+  std::shared_ptr<HttpContainer> container;
+  uint8_t *buf{nullptr};
+  size_t buf_size{0};
+  size_t read_index{0};
+  uint32_t last_data_time{0};
+  uint32_t timeout{0};
+  uint32_t start_time{0};
+  bool capture{false};
+  bool reading{false};
+  bool failed{false};
+  bool finished{false};
+  bool cancelled{false};
+};
+
 class HttpRequestComponent : public Component {
  public:
   void dump_config() override;
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; }
+  void setup() override;
+  void loop() override;
+  void on_safe_shutdown() override;
+  void on_shutdown() override;
+
+  /// For HttpRequestSendAction: queue a request and take ownership of it. Requests start in order, up to
+  /// max_concurrent_requests at a time; one that can start at once is started here.
+  void submit(PendingRequest *request);
+  /// For HttpRequestSendAction: drop the requests of a stopped action without firing their triggers.
+  void cancel(void *owner);
 
   void set_useragent(const char *useragent) { this->useragent_ = useragent; }
   void set_timeout(uint32_t timeout) { this->timeout_ = timeout; }
@@ -349,6 +410,7 @@ class HttpRequestComponent : public Component {
   }
   void set_follow_redirects(bool follow_redirects) { this->follow_redirects_ = follow_redirects; }
   void set_redirect_limit(uint16_t limit) { this->redirect_limit_ = limit; }
+  void set_max_concurrent_requests(uint8_t max_concurrent) { this->max_concurrent_ = max_concurrent; }
 
   std::shared_ptr<HttpContainer> get(const char *url) { return this->start(url, "GET", "", std::vector<Header>{}); }
   std::shared_ptr<HttpContainer> get(const char *url, const std::vector<Header> &request_headers) {
@@ -491,16 +553,44 @@ class HttpRequestComponent : public Component {
     return this->start(url.c_str(), method.c_str(), body, request_headers, lower_case_collect_headers);
   }
 
+  /// Start a request without waiting for the response, then poll() the container until it is not pending.
+  /// Returns nullptr when the request cannot be started. Platforms without a non-blocking client complete
+  /// the request here.
+  virtual std::shared_ptr<HttpContainer> begin(const char *url, const char *method, std::string &&body,
+                                               const std::vector<Header> &request_headers,
+                                               const std::vector<std::string> &lower_case_collect_headers,
+                                               uint32_t timeout_ms) {
+    return this->perform(url, method, body, request_headers, lower_case_collect_headers, timeout_ms);
+  }
+
  protected:
   virtual std::shared_ptr<HttpContainer> perform(const char *url, const char *method, const std::string &body,
                                                  const std::vector<Header> &request_headers,
                                                  const std::vector<std::string> &lower_case_collect_headers,
                                                  uint32_t timeout_ms) = 0;
+  /// Longest time one loop() pass spends reading a response body
+  static constexpr uint32_t READ_BUDGET_MS = 10;
+  /// Requests that wait for a free slot; more are dropped with on_error
+  static constexpr uint8_t MAX_QUEUED = 4;
+
+  bool process_();
+  void drain_();
+  void begin_request_(PendingRequest *request);
+  bool advance_(PendingRequest *request);
+  void finish_(PendingRequest *request);
+  void remove_dead_();
+
   const char *useragent_{nullptr};
   bool follow_redirects_{};
   uint16_t redirect_limit_{};
   uint32_t timeout_{4500};
   uint32_t watchdog_timeout_{0};
+  // Oldest first; the first max_concurrent_ live requests run
+  PendingRequest *requests_{nullptr};
+  // Depth of calls that hold request pointers; finished and cancelled requests are freed when it returns to 0
+  uint8_t busy_{0};
+  uint8_t max_concurrent_{1};
+  bool shutting_down_{false};
 };
 
 template<typename... Ts> class HttpRequestSendAction final : public Action<Ts...> {
@@ -542,7 +632,42 @@ template<typename... Ts> class HttpRequestSendAction final : public Action<Ts...
     this->max_response_buffer_size_ = max_response_buffer_size;
   }
 
-  void play(const Ts &...x) override {
+  void play_complex(const Ts &...x) override {
+    this->num_running_++;
+    this->parent_->submit(new Request(this, x...));  // NOLINT(cppcoreguidelines-owning-memory)
+  }
+
+  void play(const Ts &...x) override { /* see play_complex */ }
+
+ protected:
+  struct Request final : PendingRequest {
+    Request(HttpRequestSendAction *action, const Ts &...x)
+        : PendingRequest(&HttpRequestSendAction::handle_event, action), args(x...) {}
+    std::tuple<stored_trigger_arg_t<Ts>...> args;
+  };
+
+  static void handle_event(PendingRequest *request, RequestEvent event) {
+    auto *self = static_cast<Request *>(request);
+    auto *action = static_cast<HttpRequestSendAction *>(request->owner);
+    switch (event) {
+      case RequestEvent::REQUEST_EVENT_START:
+        std::apply([action, self](auto &...x) { action->start_request_(*self, x...); }, self->args);
+        break;
+      case RequestEvent::REQUEST_EVENT_FINISH:
+        action->finish_(*self);
+        break;
+      case RequestEvent::REQUEST_EVENT_DESTROY:
+        delete self;  // NOLINT(cppcoreguidelines-owning-memory)
+        break;
+      case RequestEvent::REQUEST_EVENT_ABANDON:
+        action->stop_complex();
+        break;
+    }
+  }
+
+  void stop() override { this->parent_->cancel(this); }
+
+  void start_request_(Request &request, const Ts &...x) {
     std::string body;
     if (this->body_.has_value()) {
       body = this->body_.value(x...);
@@ -559,62 +684,47 @@ template<typename... Ts> class HttpRequestSendAction final : public Action<Ts...
       request_headers.push_back({header.name, header.value(x...)});
     }
 
-    const uint32_t timeout = this->timeout_.has_value() ? this->timeout_.value(x...) : this->parent_->get_timeout();
-    auto container = this->parent_->start(this->url_.value(x...).c_str(), this->method_.value(x...), body,
-                                          request_headers, this->lower_case_collect_headers_, timeout);
-
-    auto captured_args = std::make_tuple(x...);
-
-    if (container == nullptr) {
-      std::apply([this](Ts... captured_args_inner) { this->error_trigger_.trigger(captured_args_inner...); },
-                 captured_args);
-      return;
-    }
-
+    request.timeout = this->timeout_.has_value() ? this->timeout_.value(x...) : this->parent_->get_timeout();
 #ifdef USE_HTTP_REQUEST_RESPONSE
-    if (this->capture_response_.value(x...)) {
-      size_t max_length = this->max_response_buffer_size_;
-      std::string response_body;
-      RAMAllocator<uint8_t> allocator;
-      uint8_t *buf = allocator.allocate(max_length);
-      if (buf != nullptr) {
-        // NOTE: HttpContainer::read() has non-BSD socket semantics - see top of this file
-        // Use http_read_loop_result() helper instead of checking return values directly
-        size_t read_index = 0;
-        uint32_t last_data_time = millis();
-        const uint32_t read_timeout = timeout;
-        while (container->get_bytes_read() < max_length) {
-          int read_or_error = container->read(buf + read_index, std::min<size_t>(max_length - read_index, 512));
-          App.feed_wdt();
-          yield();
-          auto result =
-              http_read_loop_result(read_or_error, last_data_time, read_timeout, container->is_read_complete());
-          if (result == HttpReadLoopResult::RETRY)
-            continue;
-          if (result != HttpReadLoopResult::DATA)
-            break;  // COMPLETE, ERROR, or TIMEOUT
-          read_index += read_or_error;
-        }
-        response_body.reserve(read_index);
-        response_body.assign((char *) buf, read_index);
-        allocator.deallocate(buf, max_length);
-      }
-      std::apply(
-          [this, &container, &response_body](Ts... captured_args_inner) {
-            this->success_trigger_with_response_.trigger(container, response_body, captured_args_inner...);
-          },
-          captured_args);
-    } else
+    request.capture = this->capture_response_.value(x...);
 #endif
-    {
-      std::apply([this, &container](
-                     Ts... captured_args_inner) { this->success_trigger_.trigger(container, captured_args_inner...); },
-                 captured_args);
+    request.buf_size = this->max_response_buffer_size_;
+    request.container = this->parent_->begin(this->url_.value(x...).c_str(), this->method_.value(x...), std::move(body),
+                                             request_headers, this->lower_case_collect_headers_, request.timeout);
+  }
+
+  void finish_(Request &request) {
+    auto &container = request.container;
+    if (request.failed) {
+      std::apply([this](auto &...args) { this->error_trigger_.trigger(args...); }, request.args);
     }
-    container->end();
+#ifdef USE_HTTP_REQUEST_RESPONSE
+    else if (request.capture) {
+      std::string response_body;
+      if (request.buf != nullptr)
+        response_body.assign(reinterpret_cast<char *>(request.buf), request.read_index);
+      request.free_buffer();
+      std::apply(
+          [this, &container, &response_body](auto &...args) {
+            this->success_trigger_with_response_.trigger(container, response_body, args...);
+          },
+          request.args);
+    }
+#endif
+    else {
+      std::apply([this, &container](auto &...args) { this->success_trigger_.trigger(container, args...); },
+                 request.args);
+    }
+    // End it before the chain can start another request, so that one client is held at a time
+    if (container != nullptr) {
+      container->end();
+      container.reset();
+    }
+    // A stop from the triggers ended this run; a run started after it continues the chain instead
+    if (!request.cancelled)
+      std::apply([this](auto &...args) { this->play_next_(args...); }, request.args);
   }
 
- protected:
   void encode_json_(Ts... x, JsonObject root) {
     for (const auto &item : this->json_) {
       auto val = item.second;

esphome/components/http_request/http_request_idf.cpp

@@ -2,8 +2,13 @@
 
 #ifdef USE_ESP32
 
+#include <algorithm>
+#include <cerrno>
 #include <cstring>
 
+#include <fcntl.h>
+#include <sys/select.h>
+
 #include "esphome/components/network/util.h"
 #include "esphome/components/watchdog/watchdog.h"
 
@@ -20,6 +25,10 @@
 namespace esphome::http_request {
 
 ESPHOME_LOG_TAG(TAG, "http_request");
+
+// Request body sent per esp_http_client_write() call, and the time one poll() spends sending it
+static constexpr size_t SEND_CHUNK_SIZE = 1024;
+static constexpr uint32_t SEND_BUDGET_MS = 10;
 static constexpr uint32_t ERROR_DURATION_MS = 1000;
 
 void HttpRequestIDF::dump_config() {
@@ -51,10 +60,9 @@ esp_err_t HttpRequestIDF::http_event_handler(esp_http_client_event_t *evt) {
   return ESP_OK;
 }
 
-std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const char *url, const char *method, const std::string &body,
-                                                       const std::vector<Header> &request_headers,
-                                                       const std::vector<std::string> &lower_case_collect_headers,
-                                                       uint32_t timeout_ms) {
+std::shared_ptr<HttpContainerIDF> HttpRequestIDF::create_container_(
+    const char *url, const char *method, const std::vector<Header> &request_headers,
+    const std::vector<std::string> &lower_case_collect_headers, uint32_t timeout_ms, [[maybe_unused]] bool async) {
   if (!network::is_connected()) {
     this->status_momentary_error(ERROR_DURATION_MS);
     ESP_LOGE(TAG, "HTTP Request failed; Not connected to network");
@@ -106,11 +114,12 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const char *url, const ch
   config.buffer_size = this->buffer_size_rx_;
   config.buffer_size_tx = this->buffer_size_tx_;
 
-  const uint32_t start = millis();
-  const uint32_t watchdog_timeout = this->get_watchdog_timeout(timeout_ms);
-  watchdog::WatchdogManager wdm(watchdog_timeout);
-
   config.event_handler = http_event_handler;
+#ifdef USE_HTTP_REQUEST_IDF_SOCKET_POLL
+  // Only TLS has a non-blocking connect worth having: the handshake. A plain connection waits for
+  // the TCP connection either way.
+  config.is_async = async && secure;
+#endif
 
   esp_http_client_handle_t client = esp_http_client_init(&config);
   if (client == nullptr) {
@@ -121,7 +130,9 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const char *url, const ch
 
   std::shared_ptr<HttpContainerIDF> container = std::make_shared<HttpContainerIDF>(client);
   container->set_parent(this);
-  container->set_watchdog_timeout(watchdog_timeout);
+  container->set_watchdog_timeout(this->get_watchdog_timeout(timeout_ms));
+  container->timeout_ms_ = timeout_ms;
+  container->async_ = config.is_async;
 
   container->set_secure(secure);
 
@@ -132,101 +143,229 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const char *url, const ch
     esp_http_client_set_header(client, header.name.c_str(), header.value.c_str());
   }
 
-  const int body_len = body.length();
+  return container;
+}
 
-  esp_err_t err = esp_http_client_open(client, body_len);
-  if (err != ESP_OK) {
-    this->status_momentary_error(ERROR_DURATION_MS);
-    ESP_LOGE(TAG, "HTTP Request failed: %s", esp_err_to_name(err));
-    esp_http_client_cleanup(client);
+std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const char *url, const char *method, const std::string &body,
+                                                       const std::vector<Header> &request_headers,
+                                                       const std::vector<std::string> &lower_case_collect_headers,
+                                                       uint32_t timeout_ms) {
+  std::shared_ptr<HttpContainerIDF> container = this->start_container_(url, method, std::string(body), request_headers,
+                                                                       lower_case_collect_headers, timeout_ms, false);
+  if (container == nullptr) {
     return nullptr;
   }
+  // The same stages as begin(), run here until the response headers are in
+  watchdog::WatchdogManager wdm(container->get_watchdog_timeout());
+  HttpRequestProgress progress;
+  while ((progress = container->poll()) == HttpRequestProgress::HTTP_REQUEST_PROGRESS_PENDING) {
+    container->feed_wdt();
+    delay(1);
+  }
+  if (progress == HttpRequestProgress::HTTP_REQUEST_PROGRESS_FAILED) {
+    container->end();
+    return nullptr;
+  }
+  return container;
+}
 
-  if (body_len > 0) {
-    int write_left = body_len;
-    int write_index = 0;
-    const char *buf = body.c_str();
-    while (write_left > 0) {
-      int written = esp_http_client_write(client, buf + write_index, write_left);
-      if (written <= 0) {
-        err = ESP_FAIL;
+std::shared_ptr<HttpContainer> HttpRequestIDF::begin(const char *url, const char *method, std::string &&body,
+                                                     const std::vector<Header> &request_headers,
+                                                     const std::vector<std::string> &lower_case_collect_headers,
+                                                     uint32_t timeout_ms) {
+  return this->start_container_(url, method, std::move(body), request_headers, lower_case_collect_headers, timeout_ms,
+                                true);
+}
+
+std::shared_ptr<HttpContainerIDF> HttpRequestIDF::start_container_(
+    const char *url, const char *method, std::string &&body, const std::vector<Header> &request_headers,
+    const std::vector<std::string> &lower_case_collect_headers, uint32_t timeout_ms, bool async) {
+  std::shared_ptr<HttpContainerIDF> container =
+      this->create_container_(url, method, request_headers, lower_case_collect_headers, timeout_ms, async);
+  if (container == nullptr) {
+    return nullptr;
+  }
+  container->body_ = std::move(body);
+  container->start_time_ = millis();
+  container->progress_time_ = container->start_time_;
+  container->redirects_left_ = this->follow_redirects_ ? this->redirect_limit_ : 0;
+  container->stage_ = HttpContainerIDF::Stage::STAGE_CONNECT;
+  return container;
+}
+
+HttpRequestIDF *HttpContainerIDF::idf_parent_() { return static_cast<HttpRequestIDF *>(this->parent_); }
+
+HttpRequestProgress HttpContainerIDF::fail_(esp_err_t err) {
+  ESP_LOGE(TAG, "HTTP Request failed: %s", esp_err_to_name(err));
+  this->parent_->status_momentary_error(ERROR_DURATION_MS);
+  this->stage_ = Stage::STAGE_FAILED;
+  return HttpRequestProgress::HTTP_REQUEST_PROGRESS_FAILED;
+}
+
+HttpRequestProgress HttpContainerIDF::wait_() {
+  // millis(), not the loop time: progress_time_ is set after calls that block within this pass
+  if (millis() - this->progress_time_ >= this->timeout_ms_) {
+    return this->fail_(ESP_ERR_TIMEOUT);
+  }
+  return HttpRequestProgress::HTTP_REQUEST_PROGRESS_PENDING;
+}
+
+bool HttpContainerIDF::socket_ready_(bool write) {
+#ifdef USE_HTTP_REQUEST_IDF_SOCKET_POLL
+  const int fd = esp_http_client_get_socket(this->client_);
+  if (fd < 0) {
+    return true;
+  }
+  fd_set fds;
+  FD_ZERO(&fds);
+  FD_SET(fd, &fds);
+  timeval no_wait{};
+  // An error also counts as ready, so that the call that follows reports it
+  // Qualified: esphome::select is a namespace
+  return ::select(fd + 1, write ? nullptr : &fds, write ? &fds : nullptr, nullptr, &no_wait) != 0;
+#else
+  return true;
+#endif
+}
+
+// Each stage either finishes, or returns PENDING after a call that did not wait. The waits left are
+// the name lookup and TCP connection in the first esp_http_client_open() of each hop: a non-blocking
+// esp-tls connect that times out once never completes, as select() clears the sets it keeps.
+HttpRequestProgress HttpContainerIDF::poll() {
+  while (true) {
+    switch (this->stage_) {
+      case Stage::STAGE_DONE:
+        return HttpRequestProgress::HTTP_REQUEST_PROGRESS_DONE;
+
+      case Stage::STAGE_FAILED:
+        return HttpRequestProgress::HTTP_REQUEST_PROGRESS_FAILED;
+
+      case Stage::STAGE_CONNECT: {
+        // Only the first call of a hop waits
+        watchdog::WatchdogManager wdm(this->connecting_ ? 0 : this->get_watchdog_timeout());
+        esp_http_client_set_timeout_ms(this->client_, this->connecting_ ? 1 : this->timeout_ms_);
+        this->feed_wdt();
+        esp_err_t err = esp_http_client_open(this->client_, this->body_.size());
+        this->feed_wdt();
+        if (err == ESP_ERR_HTTP_EAGAIN) {
+          this->connecting_ = true;
+          return this->wait_();
+        }
+        this->connecting_ = false;
+        if (err != ESP_OK) {
+          return this->fail_(err);
+        }
+#ifdef USE_HTTP_REQUEST_IDF_SOCKET_POLL
+        if (this->async_) {
+          // Back to a blocking socket, so that mbedtls waits for the rest of a record instead of
+          // failing; reads only start once the socket is readable
+          const int fd = esp_http_client_get_socket(this->client_);
+          const int flags = fd < 0 ? -1 : fcntl(fd, F_GETFL, 0);
+          if (flags < 0 || fcntl(fd, F_SETFL, flags & ~O_NONBLOCK) < 0) {
+            ESP_LOGE(TAG, "Could not make the socket blocking: fd %d, errno %d", fd, errno);
+            return this->fail_(ESP_FAIL);
+          }
+        }
+#endif
+        esp_http_client_set_timeout_ms(this->client_, this->timeout_ms_);
+        this->progress_time_ = millis();
+        this->stage_ = this->body_sent_ < this->body_.size() ? Stage::STAGE_SEND_BODY : Stage::STAGE_HEADERS;
         break;
       }
-      write_left -= written;
-      write_index += written;
-      container->feed_wdt();
-    }
-  }
 
-  if (err != ESP_OK) {
-    this->status_momentary_error(ERROR_DURATION_MS);
-    ESP_LOGE(TAG, "HTTP Request failed: %s", esp_err_to_name(err));
-    esp_http_client_cleanup(client);
-    return nullptr;
-  }
-
-  container->feed_wdt();
-  // esp_http_client_fetch_headers() returns 0 for chunked transfer encoding (no Content-Length header).
-  // The read() method handles content_length == 0 specially to support chunked responses.
-  container->content_length = esp_http_client_fetch_headers(client);
-  container->set_chunked(esp_http_client_is_chunked_response(client));
-  container->feed_wdt();
-  container->status_code = esp_http_client_get_status_code(client);
-  container->feed_wdt();
-  container->duration_ms = millis() - start;
-  if (is_success(container->status_code)) {
-    return container;
-  }
-
-  if (this->follow_redirects_) {
-    auto num_redirects = this->redirect_limit_;
-    while (is_redirect(container->status_code) && num_redirects > 0) {
-      err = esp_http_client_set_redirection(client);
-      if (err != ESP_OK) {
-        ESP_LOGE(TAG, "esp_http_client_set_redirection failed: %s", esp_err_to_name(err));
-        this->status_momentary_error(ERROR_DURATION_MS);
-        esp_http_client_cleanup(client);
-        return nullptr;
+      case Stage::STAGE_SEND_BODY: {
+        // esp_http_client_write() returns only once all it was given is sent, so give it a piece at a time
+        watchdog::WatchdogManager wdm(this->get_watchdog_timeout());
+        const uint32_t start = millis();
+        while (this->body_sent_ < this->body_.size()) {
+          if (!this->socket_ready_(true)) {
+            return this->wait_();
+          }
+          const size_t len = std::min(this->body_.size() - this->body_sent_, SEND_CHUNK_SIZE);
+          int written = esp_http_client_write(this->client_, this->body_.data() + this->body_sent_, len);
+          this->feed_wdt();
+          if (written < 0) {
+            return this->fail_(ESP_FAIL);
+          }
+          if (written == 0) {
+            return this->wait_();
+          }
+          this->body_sent_ += written;
+          this->progress_time_ = millis();
+          if (this->progress_time_ - start >= SEND_BUDGET_MS && this->body_sent_ < this->body_.size()) {
+            return HttpRequestProgress::HTTP_REQUEST_PROGRESS_PENDING;
+          }
+        }
+        this->body_ = std::string();
+        this->stage_ = Stage::STAGE_HEADERS;
+        break;
       }
+
+      case Stage::STAGE_HEADERS: {
+        if (!this->socket_ready_(false)) {
+          if (millis() - this->progress_time_ < this->timeout_ms_) {
+            return HttpRequestProgress::HTTP_REQUEST_PROGRESS_PENDING;
+          }
+          // As perform(), where esp_http_client_fetch_headers() times out: no response is status -1
+          return this->response_failed_(-1);
+        }
+        // The response has begun to arrive, so this waits only for the rest of the headers, or over TLS
+        // the rest of the record that holds them
+        watchdog::WatchdogManager wdm(this->get_watchdog_timeout());
+        this->feed_wdt();
+        // esp_http_client_fetch_headers() returns 0 for chunked transfer encoding (no Content-Length header)
+        const int64_t length = esp_http_client_fetch_headers(this->client_);
+        this->feed_wdt();
+        this->duration_ms = millis() - this->start_time_;
+        if (length < 0) {
+          return this->response_failed_(-1);
+        }
+        this->content_length = length;
+        this->set_chunked(esp_http_client_is_chunked_response(this->client_));
+        this->status_code = esp_http_client_get_status_code(this->client_);
+        if (is_success(this->status_code)) {
+          this->stage_ = Stage::STAGE_DONE;
+          break;
+        }
+        if (this->redirects_left_ > 0 && is_redirect(this->status_code)) {
+          esp_err_t err = esp_http_client_set_redirection(this->client_);
+          if (err != ESP_OK) {
+            ESP_LOGE(TAG, "esp_http_client_set_redirection failed: %s", esp_err_to_name(err));
+            return this->fail_(err);
+          }
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
-      char redirect_url[256]{};
-      if (esp_http_client_get_url(client, redirect_url, sizeof(redirect_url) - 1) == ESP_OK) {
-        ESP_LOGV(TAG, "redirecting to url: %s", redirect_url);
-      }
+          char redirect_url[256]{};
+          if (esp_http_client_get_url(this->client_, redirect_url, sizeof(redirect_url) - 1) == ESP_OK) {
+            ESP_LOGV(TAG, "redirecting to url: %s", redirect_url);
+          }
 #endif
-      err = esp_http_client_open(client, 0);
-      if (err != ESP_OK) {
-        ESP_LOGE(TAG, "esp_http_client_open failed: %s", esp_err_to_name(err));
-        this->status_momentary_error(ERROR_DURATION_MS);
-        esp_http_client_cleanup(client);
-        return nullptr;
+          this->redirects_left_--;
+          // Collect only the final response's headers; redirects do not resend the body
+          this->response_headers_.clear();
+          this->body_ = std::string();
+          this->body_sent_ = 0;
+          this->progress_time_ = millis();
+          this->stage_ = Stage::STAGE_CONNECT;
+          break;
+        }
+        if (is_redirect(this->status_code) && this->idf_parent_()->follow_redirects_) {
+          ESP_LOGW(TAG, "Reach redirect limit count=%d", this->idf_parent_()->redirect_limit_);
+        }
+        return this->response_failed_(this->status_code);
       }
-
-      container->feed_wdt();
-      // IDF is the only backend reusing the container across redirect hops;
-      // drop the previous hop's headers (Arduino/host collect only the final response)
-      container->response_headers_.clear();
-      container->content_length = esp_http_client_fetch_headers(client);
-      container->set_chunked(esp_http_client_is_chunked_response(client));
-      container->feed_wdt();
-      container->status_code = esp_http_client_get_status_code(client);
-      container->feed_wdt();
-      container->duration_ms = millis() - start;
-      if (is_success(container->status_code)) {
-        return container;
-      }
-
-      num_redirects--;
-    }
-
-    if (num_redirects == 0) {
-      ESP_LOGW(TAG, "Reach redirect limit count=%d", this->redirect_limit_);
     }
   }
+}
 
-  ESP_LOGE(TAG, "HTTP Request failed; URL: %s; Code: %d", url, container->status_code);
-  this->status_momentary_error(ERROR_DURATION_MS);
-  return container;
+HttpRequestProgress HttpContainerIDF::response_failed_(int status_code) {
+  this->status_code = status_code;
+  this->duration_ms = millis() - this->start_time_;
+  char url[256]{};
+  esp_http_client_get_url(this->client_, url, sizeof(url) - 1);
+  ESP_LOGE(TAG, "HTTP Request failed; URL: %s; Code: %d", url, this->status_code);
+  this->parent_->status_momentary_error(ERROR_DURATION_MS);
+  this->stage_ = Stage::STAGE_DONE;
+  return HttpRequestProgress::HTTP_REQUEST_PROGRESS_DONE;
 }
 
 bool HttpContainerIDF::is_read_complete() const {
@@ -265,8 +404,21 @@ bool HttpContainerIDF::is_read_complete() const {
 // after its internal transport timeout (configured via timeout_ms) expires.
 // This is passed through as a negative return value, which callers treat as an error.
 int HttpContainerIDF::read(uint8_t *buf, size_t max_len) {
-  const uint32_t start = millis();
   watchdog::WatchdogManager wdm(this->get_watchdog_timeout());
+  esp_http_client_set_timeout_ms(this->client_, this->timeout_ms_);
+  return this->read_(buf, max_len);
+}
+
+int HttpContainerIDF::read_available(uint8_t *buf, size_t max_len) {
+  // A zero timeout only polls; TLS still waits for the rest of a record that has begun to arrive
+  watchdog::WatchdogManager wdm(this->get_watchdog_timeout());
+  esp_http_client_set_timeout_ms(this->client_, 0);
+  int read_len_or_error = this->read_(buf, max_len);
+  return read_len_or_error == -ESP_ERR_HTTP_EAGAIN ? 0 : read_len_or_error;
+}
+
+int HttpContainerIDF::read_(uint8_t *buf, size_t max_len) {
+  const uint32_t start = millis();
 
   // Check if we've already read all expected content (non-chunked and no-body only).
   // Use the base class check here, NOT the override: esp_http_client_is_complete_data_received()

esphome/components/http_request/http_request_idf.h

@@ -5,30 +5,71 @@
 #ifdef USE_ESP32
 
 #include <esp_event.h>
+#include <esp_idf_version.h>
 #include <esp_http_client.h>
 #include <esp_netif.h>
 #include <esp_tls.h>
 
+// The socket is needed to wait for the response without blocking; esp_http_client_get_socket() is new in 5.5.3
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 5, 3)
+#define USE_HTTP_REQUEST_IDF_SOCKET_POLL
+#endif
+
 namespace esphome::http_request {
 
+class HttpRequestIDF;
+
 class HttpContainerIDF : public HttpContainer {
  public:
   HttpContainerIDF(esp_http_client_handle_t client) : client_(client) {}
   int read(uint8_t *buf, size_t max_len) override;
+  int read_available(uint8_t *buf, size_t max_len) override;
   void end() override;
   bool is_read_complete() const override;
+  HttpRequestProgress poll() override;
 
   /// @brief Feeds the watchdog timer if the executing task has one attached
   void feed_wdt();
 
  protected:
   friend class HttpRequestIDF;
+  enum class Stage : uint8_t {
+    STAGE_CONNECT,
+    STAGE_SEND_BODY,
+    STAGE_HEADERS,
+    STAGE_DONE,
+    STAGE_FAILED,
+  };
+
+  int read_(uint8_t *buf, size_t max_len);
+  /// True when the socket can be read or written without waiting; always true when it cannot be checked
+  bool socket_ready_(bool write);
+  HttpRequestProgress wait_();
+  HttpRequestProgress fail_(esp_err_t err);
+  /// Finish with an unsuccessful status, which is reported through on_response like a success
+  HttpRequestProgress response_failed_(int status_code);
+  HttpRequestIDF *idf_parent_();
+
   esp_http_client_handle_t client_;
   // Owned copy (not a reference): must outlive perform() for the response-header event handler
   std::vector<std::string> collect_headers_;
+  // Request body for begin(), released once sent
+  std::string body_;
+  size_t body_sent_{0};
+  uint32_t timeout_ms_{0};
+  // Time of the last step forward, for the request timeout of begin()
+  uint32_t progress_time_{0};
+  uint32_t start_time_{0};
+  uint16_t redirects_left_{0};
+  Stage stage_{Stage::STAGE_DONE};
+  // An esp_http_client_open() of a non-blocking client returned ESP_ERR_HTTP_EAGAIN
+  bool connecting_{false};
+  bool async_{false};
 };
 
 class HttpRequestIDF final : public HttpRequestComponent {
+  friend class HttpContainerIDF;
+
  public:
   // User provided, not "= default": `new(p) HttpRequestIDF()` would zero-fill .bss that is already zero.
   HttpRequestIDF() {}
@@ -40,7 +81,21 @@ class HttpRequestIDF final : public HttpRequestComponent {
   void set_verify_ssl(bool verify_ssl) { this->verify_ssl_ = verify_ssl; }
   void set_ca_certificate(const char *ca_certificate) { this->ca_certificate_ = ca_certificate; }
 
+  std::shared_ptr<HttpContainer> begin(const char *url, const char *method, std::string &&body,
+                                       const std::vector<Header> &request_headers,
+                                       const std::vector<std::string> &lower_case_collect_headers,
+                                       uint32_t timeout_ms) override;
+
  protected:
+  /// A container that poll() takes from the connect through to the response headers
+  std::shared_ptr<HttpContainerIDF> start_container_(const char *url, const char *method, std::string &&body,
+                                                     const std::vector<Header> &request_headers,
+                                                     const std::vector<std::string> &lower_case_collect_headers,
+                                                     uint32_t timeout_ms, bool async);
+  std::shared_ptr<HttpContainerIDF> create_container_(const char *url, const char *method,
+                                                      const std::vector<Header> &request_headers,
+                                                      const std::vector<std::string> &lower_case_collect_headers,
+                                                      uint32_t timeout_ms, bool async);
   std::shared_ptr<HttpContainer> perform(const char *url, const char *method, const std::string &body,
                                          const std::vector<Header> &request_headers,
                                          const std::vector<std::string> &lower_case_collect_headers,

esphome/components/lvgl/defines.py

@@ -729,7 +729,6 @@ CONF_DISP_BG_COLOR = "disp_bg_color"
 CONF_DISP_BG_IMAGE = "disp_bg_image"
 CONF_DISP_BG_OPA = "disp_bg_opa"
 CONF_BODY = "body"
-CONF_BUTTONS = "buttons"
 CONF_CHANGE_RATE = "change_rate"
 CONF_CLICKABLE = "clickable"
 CONF_CLOSE_BUTTON = "close_button"

esphome/components/lvgl/widgets/buttonmatrix.py

@@ -1,6 +1,6 @@
 from esphome import automation
 import esphome.codegen as cg
-from esphome.components.const import CONF_ROWS
+from esphome.components.const import CONF_BUTTONS, CONF_ROWS
 from esphome.components.key_provider import KeyProvider
 import esphome.config_validation as cv
 from esphome.const import CONF_ID, CONF_ITEMS, CONF_TEXT, CONF_WIDTH
@@ -10,7 +10,6 @@ from esphome.types import Expression
 from ..automation import action_to_code
 from ..defines import (
     BUTTONMATRIX_CTRLS,
-    CONF_BUTTONS,
     CONF_CONTROL,
     CONF_KEY_CODE,
     CONF_MAIN,

esphome/components/lvgl/widgets/msgbox.py

@@ -1,4 +1,5 @@
 from esphome import codegen as cg, config_validation as cv
+from esphome.components.const import CONF_BUTTONS
 from esphome.const import CONF_BUTTON, CONF_HIDDEN, CONF_ID, CONF_TEXT
 from esphome.core import ID
 from esphome.cpp_generator import MockObjClass
@@ -7,7 +8,6 @@ from esphome.cpp_types import nullptr
 from ..defines import (
     CONF_BODY,
     CONF_BUTTON_STYLE,
-    CONF_BUTTONS,
     CONF_CLOSE_BUTTON,
     CONF_HEADER_BUTTONS,
     CONF_MAIN,

esphome/components/mqtt/__init__.py

@@ -87,6 +87,11 @@ from esphome.core import CORE, CoroPriority, coroutine_with_priority
 from esphome.cpp_generator import MockObjClass
 import esphome.final_validate as fv
 from esphome.helpers import sanitize, snake_case
+from esphome.mqtt_topics import (
+    DEFAULT_TOPIC_SUFFIXES,
+    per_board_suffix,
+    prefix_gets_mac_suffix,
+)
 from esphome.types import ConfigType
 
 DEPENDENCIES = ["network"]
@@ -266,6 +271,31 @@ def _validate_transport(value: str) -> str:
     return value
 
 
+# (config key, extra fields when defaulted from the topic prefix, (setter, disabler))
+_MESSAGES = (
+    (
+        CONF_BIRTH_MESSAGE,
+        {CONF_PAYLOAD: "online"},
+        lambda var: (var.set_birth_message, var.disable_birth_message),
+    ),
+    (
+        CONF_WILL_MESSAGE,
+        {CONF_PAYLOAD: "offline"},
+        lambda var: (var.set_last_will, var.disable_last_will),
+    ),
+    (
+        CONF_SHUTDOWN_MESSAGE,
+        {CONF_PAYLOAD: "offline"},
+        lambda var: (var.set_shutdown_message, var.disable_shutdown_message),
+    ),
+    (
+        CONF_LOG_TOPIC,
+        {},
+        lambda var: (var.set_log_message_template, var.disable_log_message),
+    ),
+)
+
+
 def validate_config(value):
     if (
         value.get(CONF_TRANSPORT) not in (MQTT_TRANSPORT_WS, MQTT_TRANSPORT_WSS)
@@ -280,45 +310,19 @@ def validate_config(value):
     topic_prefix = value[CONF_TOPIC_PREFIX]
     # If the topic prefix is not null and these messages are not configured, then set them to the default
     # If the topic prefix is null and these messages are not configured, then set them to null
-    if CONF_BIRTH_MESSAGE not in value:
-        if topic_prefix != "":
-            out[CONF_BIRTH_MESSAGE] = {
-                CONF_TOPIC: f"{topic_prefix}/status",
-                CONF_PAYLOAD: "online",
+    for key, extra, _ in _MESSAGES:
+        if key in value:
+            continue
+        out[key] = (
+            {}
+            if topic_prefix == ""
+            else {
+                CONF_TOPIC: f"{topic_prefix}{DEFAULT_TOPIC_SUFFIXES[key]}",
+                **extra,
                 CONF_QOS: 0,
                 CONF_RETAIN: True,
             }
-        else:
-            out[CONF_BIRTH_MESSAGE] = {}
-    if CONF_WILL_MESSAGE not in value:
-        if topic_prefix != "":
-            out[CONF_WILL_MESSAGE] = {
-                CONF_TOPIC: f"{topic_prefix}/status",
-                CONF_PAYLOAD: "offline",
-                CONF_QOS: 0,
-                CONF_RETAIN: True,
-            }
-        else:
-            out[CONF_WILL_MESSAGE] = {}
-    if CONF_SHUTDOWN_MESSAGE not in value:
-        if topic_prefix != "":
-            out[CONF_SHUTDOWN_MESSAGE] = {
-                CONF_TOPIC: f"{topic_prefix}/status",
-                CONF_PAYLOAD: "offline",
-                CONF_QOS: 0,
-                CONF_RETAIN: True,
-            }
-        else:
-            out[CONF_SHUTDOWN_MESSAGE] = {}
-    if CONF_LOG_TOPIC not in value:
-        if topic_prefix != "":
-            out[CONF_LOG_TOPIC] = {
-                CONF_TOPIC: f"{topic_prefix}/debug",
-                CONF_QOS: 0,
-                CONF_RETAIN: True,
-            }
-        else:
-            out[CONF_LOG_TOPIC] = {}
+        )
     return out
 
 
@@ -558,7 +562,7 @@ def _subscriptions(config: ConfigType) -> Iterator[tuple[tuple[str, ...], ...]]:
         for device in esphome_config.get(CONF_DEVICES, [])
     }
     topic_prefix = config[CONF_TOPIC_PREFIX]
-    if mac_suffix and topic_prefix == CORE.name:
+    if prefix_gets_mac_suffix(topic_prefix, CORE.name, mac_suffix):
         topic_prefix += MAC_SUFFIX
     # Entities can sit at any depth (a platform can declare its own switches), so find them by mqtt_id
     for id_, path in iter_ids(full_config):
@@ -607,12 +611,14 @@ def _validate_topic_lengths(config: ConfigType) -> ConfigType:
 FINAL_VALIDATE_SCHEMA = _validate_topic_lengths
 
 
-def exp_mqtt_message(config):
+def exp_mqtt_message(
+    config: ConfigType | None, topic: cg.MockObj | None = None
+) -> cg.Expression:
     if config is None:
         return cg.optional(cg.TemplateArguments(MQTTMessage))
     return cg.StructInitializer(
         MQTTMessage,
-        ("topic", config[CONF_TOPIC]),
+        ("topic", config[CONF_TOPIC] if topic is None else topic),
         ("payload", config.get(CONF_PAYLOAD, "")),
         ("qos", config[CONF_QOS]),
         ("retain", config[CONF_RETAIN]),
@@ -696,37 +702,33 @@ async def to_code(config):
             )
         )
 
-    cg.add(var.set_topic_prefix(config[CONF_TOPIC_PREFIX], CORE.name))
+    topic_prefix = config[CONF_TOPIC_PREFIX]
+    # The MAC suffix is only known at runtime, so the prefix and the topics defaulted from it
+    # are built from App.get_name(); topics written out by hand stay literal
+    mac_suffix = CORE.config[CONF_ESPHOME].get(CONF_NAME_ADD_MAC_SUFFIX, False)
+    mac_prefix = prefix_gets_mac_suffix(topic_prefix, CORE.name, mac_suffix)
+    cg.add(var.set_topic_prefix(cg.App.get_name() if mac_prefix else topic_prefix))
 
     if config[CONF_USE_ABBREVIATIONS]:
         cg.add_define("USE_MQTT_ABBREVIATIONS")
 
-    birth_message = config[CONF_BIRTH_MESSAGE]
-    if not birth_message:
-        cg.add(var.disable_birth_message())
-    else:
-        cg.add(var.set_birth_message(exp_mqtt_message(birth_message)))
-    will_message = config[CONF_WILL_MESSAGE]
-    if not will_message:
-        cg.add(var.disable_last_will())
-    else:
-        cg.add(var.set_last_will(exp_mqtt_message(will_message)))
-    shutdown_message = config[CONF_SHUTDOWN_MESSAGE]
-    if not shutdown_message:
-        cg.add(var.disable_shutdown_message())
-    else:
-        cg.add(var.set_shutdown_message(exp_mqtt_message(shutdown_message)))
+    for key, _, methods in _MESSAGES:
+        set_message, disable_message = methods(var)
+        if not (message := config[key]):
+            cg.add(disable_message())
+            continue
+        topic = (
+            cg.App.get_name() + suffix
+            if (suffix := per_board_suffix(config, key, CORE.name, mac_suffix))
+            else None
+        )
+        cg.add(set_message(exp_mqtt_message(message, topic)))
 
-    log_topic = config[CONF_LOG_TOPIC]
-    if not log_topic:
-        cg.add(var.disable_log_message())
-    else:
-        cg.add(var.set_log_message_template(exp_mqtt_message(log_topic)))
+    if log_topic := config[CONF_LOG_TOPIC]:
         # Request a log listener slot only when log topic is enabled
         logger.request_log_listener()
-
-        if CONF_LEVEL in log_topic:
-            cg.add(var.set_log_level(logger.LOG_LEVELS[log_topic[CONF_LEVEL]]))
+        if (level := log_topic.get(CONF_LEVEL)) is not None:
+            cg.add(var.set_log_level(logger.LOG_LEVELS[level]))
 
     cg.add(var.set_keep_alive(config[CONF_KEEPALIVE]))
 

esphome/components/mqtt/mqtt_client.cpp

@@ -737,14 +737,7 @@ void MQTTClientComponent::register_mqtt_component(MQTTComponent *component) { th
 void MQTTClientComponent::set_keep_alive(uint16_t keep_alive_s) { this->mqtt_backend_.set_keep_alive(keep_alive_s); }
 void MQTTClientComponent::set_log_message_template(MQTTMessage &&message) { this->log_message_ = std::move(message); }
 const MQTTDiscoveryInfo &MQTTClientComponent::get_discovery_info() const { return this->discovery_info_; }
-void MQTTClientComponent::set_topic_prefix(const std::string &topic_prefix, const std::string &check_topic_prefix) {
-  if (App.is_name_add_mac_suffix_enabled() && (topic_prefix == check_topic_prefix)) {
-    char buf[ESPHOME_DEVICE_NAME_MAX_LEN + 1];
-    this->topic_prefix_ = str_sanitize_to(buf, App.get_name().c_str());
-  } else {
-    this->topic_prefix_ = topic_prefix;
-  }
-}
+void MQTTClientComponent::set_topic_prefix(std::string topic_prefix) { this->topic_prefix_ = std::move(topic_prefix); }
 const std::string &MQTTClientComponent::get_topic_prefix() const { return this->topic_prefix_; }
 void MQTTClientComponent::disable_birth_message() {
   this->birth_message_.topic = "";

esphome/components/mqtt/mqtt_client.h

@@ -201,7 +201,7 @@ class MQTTClientComponent final : public Component {
    *
    * @param topic_prefix The topic prefix. The last "/" is appended automatically.
    */
-  void set_topic_prefix(const std::string &topic_prefix, const std::string &check_topic_prefix);
+  void set_topic_prefix(std::string topic_prefix);
   /// Get the topic prefix of this device, using default if necessary
   const std::string &get_topic_prefix() const;
 

esphome/components/online_image/online_image.cpp

@@ -231,30 +231,47 @@ void OnlineImage::loop() {
       this->end_connection_();
       this->download_error_callback_.call();
       return;
-    } else if (this->downloader_->is_read_complete()) {
-      // The response has ended, so data left in the buffer can never be completed
-      size_t unread = this->download_buffer_.unread();
-      if (unread == 0 && this->downloader_->get_bytes_read() > 0) {
-        // A decoder that counts pixels knows the image was cut off; PNG cannot tell, so it passes
-        if (this->is_decode_finished() || !this->decoder_knows_end()) {
-          this->finish_download_();
+    } else {
+      // Nothing new arrived. The decoder works for a limited time per call, so it may still have data to use.
+      if (this->download_buffer_.unread() != 0) {
+        auto consumed = this->feed_data(this->download_buffer_.data(), this->download_buffer_.unread());
+        if (consumed < 0) {
+          ESP_LOGE(TAG, "Error decoding image: %s", esphome::runtime_image::decode_error_to_string(consumed));
+          this->end_connection_();
+          this->download_error_callback_.call();
+          return;
+        }
+        if (consumed > 0) {
+          this->download_buffer_.read(consumed);
+          this->last_data_time_ = App.get_loop_component_start_time();
           return;
         }
-        ESP_LOGE(TAG, "Download ended before the image was complete");
-      } else if (unread == 0) {
-        ESP_LOGE(TAG, "Server sent an empty response");
-      } else {
-        ESP_LOGE(TAG, "Download ended with %zu bytes the decoder could not use", unread);
       }
-      this->end_connection_();
-      this->download_error_callback_.call();
-      return;
-    } else if (App.get_loop_component_start_time() - this->last_data_time_ >= this->parent_->get_timeout()) {
-      // ESP-IDF keeps returning 0 after the server closes the connection early
-      ESP_LOGE(TAG, "No data received for %" PRIu32 " ms", this->parent_->get_timeout());
-      this->end_connection_();
-      this->download_error_callback_.call();
-      return;
+      if (this->downloader_->is_read_complete()) {
+        // The response has ended, so data left in the buffer can never be completed
+        size_t unread = this->download_buffer_.unread();
+        if (unread == 0 && this->downloader_->get_bytes_read() > 0) {
+          // A decoder that counts pixels knows the image was cut off; PNG cannot tell, so it passes
+          if (this->is_decode_finished() || !this->decoder_knows_end()) {
+            this->finish_download_();
+            return;
+          }
+          ESP_LOGE(TAG, "Download ended before the image was complete");
+        } else if (unread == 0) {
+          ESP_LOGE(TAG, "Server sent an empty response");
+        } else {
+          ESP_LOGE(TAG, "Download ended with %zu bytes the decoder could not use", unread);
+        }
+        this->end_connection_();
+        this->download_error_callback_.call();
+        return;
+      } else if (App.get_loop_component_start_time() - this->last_data_time_ >= this->parent_->get_timeout()) {
+        // ESP-IDF keeps returning 0 after the server closes the connection early
+        ESP_LOGE(TAG, "No data received for %" PRIu32 " ms", this->parent_->get_timeout());
+        this->end_connection_();
+        this->download_error_callback_.call();
+        return;
+      }
     }
   } else {
     // Buffer is full, need to decode some data first

esphome/components/packet_interface/__init__.py

@@ -1,3 +1,5 @@
+import importlib
+import pkgutil
 from typing import Any
 
 import esphome.codegen as cg
@@ -7,14 +9,27 @@ from esphome.const import CONF_ID
 from esphome.cpp_generator import MockObj, MockObjClass
 from esphome.types import ConfigType
 
+from . import layers
+from .layers import (
+    PacketInterface,
+    build_stack,
+    check_session,
+    packet_interface_ns,
+    stack_auto_load,
+    stack_schema,
+)
+
 CODEOWNERS = ["@clydebarrow"]
 DOMAIN = "packet_interface"
 IS_PLATFORM_COMPONENT = True
 
 CONF_PACKET_INTERFACE = "packet_interface"
 
-packet_interface_ns = cg.esphome_ns.namespace("packet_interface")
-PacketInterface = packet_interface_ns.class_("PacketInterface", cg.Component)
+# Each module in layers registers a layer type; import them all before building the schemas from the registry
+for module_info in pkgutil.iter_modules(layers.__path__):
+    importlib.import_module(f".layers.{module_info.name}", package=__package__)
+
+LINK_LAYER_SCHEMAS = stack_schema()
 
 __all__ = [
     "CONF_MAX_PACKET_SIZE",
@@ -26,24 +41,47 @@ __all__ = [
 ]
 
 
+def AUTO_LOAD(config: list[ConfigType] | None = None) -> list[str]:
+    """Load only what the configured layers use.
+
+    Without a config, as tooling that lists dependencies calls it, everything a layer could load.
+    """
+    if config is None:
+        return ["binary_sensor", "xxtea"]
+    loads: set[str] = set()
+    for interface in config:
+        loads |= stack_auto_load(interface)
+    return sorted(loads)
+
+
+def _validate_layers(config: ConfigType) -> ConfigType:
+    check_session(config)
+    return config
+
+
 def packet_interface_schema(
     class_: MockObjClass,
     default_max_packet_size: int,
     max_packet_size_limit: int = 4096,
 ) -> cv.Schema:
-    """Schema for a link platform."""
-    return cv.Schema(
-        {
-            cv.GenerateID(): cv.declare_id(class_),
-            cv.Optional(
-                CONF_MAX_PACKET_SIZE, default=default_max_packet_size
-            ): cv.int_range(16, max_packet_size_limit),
-        }
-    ).extend(cv.COMPONENT_SCHEMA)
+    """Schema for a link platform, with the layers that can be stacked on it."""
+    return (
+        cv.Schema(
+            {
+                cv.GenerateID(): cv.declare_id(class_),
+                cv.Optional(
+                    CONF_MAX_PACKET_SIZE, default=default_max_packet_size
+                ): cv.int_range(16, max_packet_size_limit),
+                **LINK_LAYER_SCHEMAS,
+            }
+        )
+        .extend(cv.COMPONENT_SCHEMA)
+        .add_extra(_validate_layers)
+    )
 
 
 async def new_packet_interface(config: ConfigType, *args: Any) -> MockObj:
-    """Create the link layer.
+    """Create the link layer and the layers configured on it, from the bottom up.
 
     The link's constructor takes its maximum packet size, usually as a std::span over a buffer that code generation
     sized from the configuration, so the two cannot differ.
@@ -53,4 +91,5 @@ async def new_packet_interface(config: ConfigType, *args: Any) -> MockObj:
     var = cg.new_Pvariable(config[CONF_ID], *args)
     cg.add(var.set_name(config[CONF_ID].id))
     await cg.register_component(var, config)
+    await build_stack(config, var)
     return var

esphome/components/packet_interface/basic_session.cpp

@@ -0,0 +1,135 @@
+#include "basic_session.h"
+#ifdef USE_PACKET_INTERFACE_BASIC_SESSION
+#include "esphome/core/application.h"
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
+
+namespace esphome::packet_interface {
+
+ESPHOME_LOG_TAG(TAG, "packet_interface.session");
+
+static constexpr uint8_t PACKET_TYPE_DATA = 0x00;
+static constexpr uint8_t PACKET_TYPE_KEEP_ALIVE = 0x01;
+// Type byte and the 32-bit boot id, little endian
+static constexpr size_t KEEP_ALIVE_SIZE = 5;
+
+BasicSession::BasicSession(PacketInterface *lower)
+    : PacketInterface(remaining_packet_size(lower->get_max_packet_size(), HEADER_SIZE)), lower_(lower) {
+  this->stack_on_(lower, CAPABILITY_SESSION);
+  // Data lost by a reliability layer below must be sent again, as after a restart of the peer
+  if (lower->has_capability(CAPABILITY_RELIABILITY)) {
+    lower->add_on_session_state_callback([this](bool connected) {
+      if (!connected && this->connected_)
+        this->set_connected_(false);
+    });
+  }
+}
+
+void BasicSession::setup() {
+  if (this->lower_->get_max_packet_size() < KEEP_ALIVE_SIZE) {
+    this->mark_failed(LOG_STR("max_packet_size too small for the configured layers"));
+    return;
+  }
+  this->boot_id_ = random_uint32();
+#ifdef USE_BINARY_SENSOR
+  if (this->connected_sensor_ != nullptr)
+    this->connected_sensor_->publish_initial_state(false);
+#endif
+  this->lower_->add_packet_interface_listener(
+      [this](const PacketBuffer &data, const PacketMetaData &meta_data) { this->receive_(data, meta_data); });
+  // A reliability layer below queues this until its link is up, so the peer hears of a restart straight away
+  this->send_keep_alive_();
+  this->set_interval(this->keep_alive_ms_, [this] { this->on_interval_(); });
+}
+
+void BasicSession::dump_config() {
+  ESP_LOGCONFIG(TAG,
+                "Basic Session on '%s':\n"
+                "  Max Packet Size: %zu\n"
+                "  Keep Alive: %" PRIu32 "ms\n"
+                "  Timeout: %" PRIu32 "ms",
+                this->name_, this->max_packet_size_, this->keep_alive_ms_, this->timeout_ms_);
+#ifdef USE_BINARY_SENSOR
+  LOG_BINARY_SENSOR("  ", "Connected", this->connected_sensor_);
+#endif
+}
+
+bool BasicSession::send_to_interface(const PacketBuffer &data, const PacketMetaData &meta_data) {
+  if (this->is_failed())
+    return false;
+  uint8_t header = PACKET_TYPE_DATA;
+  PacketBuffer packet(&header, HEADER_SIZE, &data, nullptr, 0);
+  return this->lower_->send_to_interface(packet, meta_data);
+}
+
+void BasicSession::send_keep_alive_() {
+  uint8_t packet[KEEP_ALIVE_SIZE] = {
+      PACKET_TYPE_KEEP_ALIVE, static_cast<uint8_t>(this->boot_id_), static_cast<uint8_t>(this->boot_id_ >> 8),
+      static_cast<uint8_t>(this->boot_id_ >> 16), static_cast<uint8_t>(this->boot_id_ >> 24)};
+  if (!this->lower_->send_to_interface(PacketBuffer(packet, sizeof(packet)), {}))
+    ESP_LOGV(TAG, "%s: Lower layer did not accept keep-alive", this->name_);
+}
+
+void BasicSession::on_interval_() {
+  this->send_keep_alive_();
+  if (this->connected_ && App.get_loop_component_start_time() - this->last_receive_ms_ > this->timeout_ms_) {
+    ESP_LOGW(TAG, "%s: Peer not heard for %" PRIu32 "ms", this->name_, this->timeout_ms_);
+    this->set_connected_(false);
+  }
+}
+
+void BasicSession::set_connected_(bool connected) {
+  this->connected_ = connected;
+  ESP_LOGD(TAG, "%s: Session %s", this->name_, connected ? LOG_STR_LITERAL("connected") : LOG_STR_LITERAL("lost"));
+#ifdef USE_BINARY_SENSOR
+  if (this->connected_sensor_ != nullptr)
+    this->connected_sensor_->publish_state(connected);
+#endif
+  this->session_callback_.call(connected);
+}
+
+void BasicSession::receive_(const PacketBuffer &data, const PacketMetaData &meta_data) {
+  // Lower layers deliver packets in one piece; the payload is passed up without copying
+  if (!data.is_contiguous()) {
+    ESP_LOGW(TAG, "%s: Packet split across buffers is not supported", this->name_);
+    return;
+  }
+  auto packet = data.as_span();
+  if (packet.empty()) {
+    this->note_received_(false);
+    return;
+  }
+  uint8_t type = packet[0];
+  if (type == PACKET_TYPE_KEEP_ALIVE) {
+    if (packet.size() != KEEP_ALIVE_SIZE) {
+      ESP_LOGV(TAG, "%s: Keep-alive of %zu bytes dropped", this->name_, packet.size());
+      this->note_received_(false);
+      return;
+    }
+    uint32_t boot_id = encode_uint32(packet[4], packet[3], packet[2], packet[1]);
+    if (!this->peer_known_ || boot_id != this->peer_boot_id_) {
+      // Data may arrive before the first keep-alive, so only a changed id means a restart
+      if (this->connected_ && this->peer_known_) {
+        ESP_LOGD(TAG, "%s: Peer has restarted", this->name_);
+        this->set_connected_(false);
+      }
+      this->peer_boot_id_ = boot_id;
+      this->peer_known_ = true;
+      // Answer a new peer at once; it answers only if our id is new to it, so this cannot repeat
+      this->send_keep_alive_();
+    }
+  } else if (type != PACKET_TYPE_DATA) {
+    ESP_LOGV(TAG, "%s: Unknown packet type 0x%02X dropped", this->name_, type);
+    this->note_received_(false);
+    return;
+  }
+  this->note_received_(true);
+  this->last_receive_ms_ = App.get_loop_component_start_time();
+  if (!this->connected_)
+    this->set_connected_(true);
+  if (type == PACKET_TYPE_DATA)
+    this->on_receive_from_interface_(PacketBuffer(packet.data() + HEADER_SIZE, packet.size() - HEADER_SIZE), meta_data);
+}
+
+}  // namespace esphome::packet_interface
+#endif

esphome/components/packet_interface/basic_session.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include "esphome/core/defines.h"
+#ifdef USE_PACKET_INTERFACE_BASIC_SESSION
+#include "packet_interface.h"
+#ifdef USE_BINARY_SENSOR
+#include "esphome/components/binary_sensor/binary_sensor.h"
+#endif
+
+namespace esphome::packet_interface {
+
+/**
+ * A session layer that reports whether the peer can be reached.
+ *
+ * Every packet starts with a type byte. A data packet carries the payload of the layer above. A keep-alive packet
+ * carries a random number chosen at boot, so that a restart of the peer is noticed even if it is quicker than the
+ * timeout. A keep-alive is sent every keep_alive interval, and at once when a new peer is heard. The peer is
+ * considered gone when nothing has been received from it for the timeout; this is checked every keep_alive interval.
+ * A restart of the peer is reported as a disconnect followed by a connect. So is a reset of a reliability layer below,
+ * which discards data: the session is reported lost, and connected again when the peer is next heard.
+ */
+class BasicSession : public PacketInterface {
+ public:
+  /// The packet type byte.
+  static constexpr size_t HEADER_SIZE = 1;
+
+  explicit BasicSession(PacketInterface *lower);
+
+  void setup() override;
+  void dump_config() override;
+  bool send_to_interface(const PacketBuffer &data, const PacketMetaData &meta_data) override;
+
+  void set_keep_alive(uint32_t keep_alive_ms) { this->keep_alive_ms_ = keep_alive_ms; }
+  void set_session_timeout(uint32_t timeout_ms) { this->timeout_ms_ = timeout_ms; }
+#ifdef USE_BINARY_SENSOR
+  void set_connected_sensor(binary_sensor::BinarySensor *sensor) { this->connected_sensor_ = sensor; }
+#endif
+
+  bool is_connected() const { return this->connected_; }
+
+ protected:
+  void receive_(const PacketBuffer &data, const PacketMetaData &meta_data);
+  void on_interval_();
+  void send_keep_alive_();
+  void set_connected_(bool connected);
+
+  PacketInterface *lower_;
+#ifdef USE_BINARY_SENSOR
+  binary_sensor::BinarySensor *connected_sensor_{nullptr};
+#endif
+  uint32_t keep_alive_ms_{10000};
+  uint32_t timeout_ms_{30000};
+  uint32_t last_receive_ms_{0};
+  uint32_t boot_id_{0};
+  uint32_t peer_boot_id_{0};
+  bool peer_known_{false};
+  bool connected_{false};
+};
+
+}  // namespace esphome::packet_interface
+#endif

esphome/components/packet_interface/hdlc_reliability.cpp

@@ -0,0 +1,365 @@
+#include "hdlc_reliability.h"
+#ifdef USE_PACKET_INTERFACE_HDLC
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
+
+namespace esphome::packet_interface {
+
+ESPHOME_LOG_TAG(TAG, "packet_interface.hdlc");
+
+static constexpr uint32_t RETRANSMIT_TIMER_ID = 0;
+static constexpr uint32_t ACK_TIMER_ID = 1;
+static constexpr uint32_t SEND_RETRY_TIMER_ID = 2;
+// A frame or acknowledgement the lower layer refused, for example while a radio was receiving, is sent again after this
+static constexpr uint32_t SEND_RETRY_MS = 50;
+// SABM is repeated at this interval, or the timeout if longer, until the peer answers
+static constexpr uint32_t RESET_INTERVAL_MS = 1000;
+
+// Control byte formats, with the poll/final bit (0x10) ignored
+static constexpr uint8_t POLL_FINAL_BIT = 0x10;
+static constexpr uint8_t SUPERVISORY_FRAME = 0x01;
+static constexpr uint8_t SUPERVISORY_RR = 0x00;
+static constexpr uint8_t SUPERVISORY_REJ = 0x02;
+static constexpr uint8_t UNNUMBERED_SABM = 0x2F;
+static constexpr uint8_t UNNUMBERED_UA = 0x63;
+
+static uint16_t frame_crc(uint8_t control, const uint8_t *payload, size_t length) {
+  uint16_t crc = crc16(&control, 1);
+  return crc16(payload, length, crc);
+}
+
+HdlcReliability::HdlcReliability(PacketInterface *lower)
+    : PacketInterface(remaining_packet_size(lower->get_max_packet_size(), FRAME_OVERHEAD)), lower_(lower) {
+  this->stack_on_(lower, CAPABILITY_RELIABILITY);
+}
+
+void HdlcReliability::setup() {
+  if (this->max_packet_size_ == 0) {
+    this->mark_failed(LOG_STR("max_packet_size too small for the configured layers"));
+    return;
+  }
+  RAMAllocator<uint8_t> allocator;
+  this->tx_slots_ = allocator.allocate(size_t{this->max_queue_length_} * this->max_packet_size_);
+  if (this->tx_slots_ == nullptr) {
+    this->mark_failed(LOG_STR("Not enough memory for the send queue"));
+    return;
+  }
+  this->lower_->add_packet_interface_listener(
+      [this](const PacketBuffer &data, const PacketMetaData &meta_data) { this->receive_(data, meta_data); });
+}
+
+void HdlcReliability::dump_config() {
+  ESP_LOGCONFIG(TAG,
+                "HDLC Reliability on '%s':\n"
+                "  Max Packet Size: %zu\n"
+                "  Timeout: %" PRIu32 "ms\n"
+                "  Ack Delay: %" PRIu32 "ms\n"
+                "  Max Queue Length: %u\n"
+                "  Max Retries: %u",
+                this->name_, this->max_packet_size_, this->timeout_ms_, this->ack_delay_ms_, this->max_queue_length_,
+                this->max_retries_);
+}
+
+void HdlcReliability::loop() {
+  // Disabled first, as sending may deliver a reply to this layer and request the loop again
+  this->disable_loop();
+  if (this->state_ == LinkState::LINK_STATE_RESET_PENDING) {
+    this->state_ = LinkState::LINK_STATE_RESETTING;
+    this->start_timer_();
+    this->send_frame_(UNNUMBERED_SABM, nullptr, 0);
+  }
+  if (this->state_ != LinkState::LINK_STATE_CONNECTED)
+    return;
+  // Queued frames go first, as each carries the acknowledgement
+  if (this->send_pending_() && this->ack_due_ && !this->send_supervisory_(SUPERVISORY_RR))
+    this->retry_send_();
+}
+
+void HdlcReliability::retry_send_() {
+  this->set_timeout(SEND_RETRY_TIMER_ID, SEND_RETRY_MS, [this]() { this->request_loop_(); });
+}
+
+void HdlcReliability::owe_ack_(bool now) {
+  if (now || this->ack_delay_ms_ == 0) {
+    this->ack_due_ = true;
+    this->request_loop_();
+  } else if (!this->ack_pending_) {
+    // Waiting lets one acknowledgement cover several frames, or a reply carry it
+    this->set_timeout(ACK_TIMER_ID, this->ack_delay_ms_, [this]() {
+      this->ack_due_ = true;
+      this->request_loop_();
+    });
+  }
+  this->ack_pending_ = true;
+}
+
+void HdlcReliability::ack_sent_() {
+  this->ack_pending_ = false;
+  this->ack_due_ = false;
+  this->cancel_timeout(ACK_TIMER_ID);
+}
+
+void HdlcReliability::request_loop_() { this->enable_loop(); }
+
+bool HdlcReliability::send_to_interface(const PacketBuffer &data, const PacketMetaData &meta_data) {
+  if (this->tx_slots_ == nullptr)
+    return false;
+  size_t size = data.size();
+  if (size > this->max_packet_size_) {
+    ESP_LOGW(TAG, "%s: Packet of %zu bytes is larger than %zu", this->name_, size, this->max_packet_size_);
+    return false;
+  }
+  uint8_t outstanding = this->outstanding_();
+  if (outstanding >= this->max_queue_length_) {
+    if (this->state_ == LinkState::LINK_STATE_CONNECTED) {
+      ESP_LOGV(TAG, "%s: Send queue full", this->name_);
+    } else if (!this->reset_wait_logged_) {
+      // Once for each reset; the layers above keep trying while the peer is away
+      this->reset_wait_logged_ = true;
+      ESP_LOGD(TAG, "%s: Send queue full, waiting for the peer to answer the link reset", this->name_);
+    }
+    return false;
+  }
+  uint8_t seq = this->vs_;
+  data.copy_to(this->slot_(seq), size);
+  this->tx_lengths_[this->slot_index_(seq)] = size;
+  this->vs_ = (seq + 1) & 7;
+  // While the link is being reset, the frame waits in the queue and is sent when UA arrives
+  if (this->state_ == LinkState::LINK_STATE_CONNECTED) {
+    this->send_pending_();
+    if (outstanding == 0)
+      this->start_timer_();
+  }
+  return true;
+}
+
+bool HdlcReliability::send_frame_(uint8_t control, const uint8_t *payload, size_t length) {
+  uint16_t crc = frame_crc(control, payload, length);
+  uint8_t trailer[2] = {static_cast<uint8_t>(crc), static_cast<uint8_t>(crc >> 8)};
+  PacketBuffer body(payload, length);
+  PacketBuffer frame(&control, 1, length != 0 ? &body : nullptr, trailer, sizeof(trailer));
+  if (this->lower_->send_to_interface(frame, {}))
+    return true;
+  ESP_LOGV(TAG, "%s: Lower layer did not accept frame 0x%02X", this->name_, control);
+  return false;
+}
+
+bool HdlcReliability::send_supervisory_(uint8_t type) {
+  if (!this->send_frame_(SUPERVISORY_FRAME | (type << 2) | (this->vr_ << 5), nullptr, 0))
+    return false;
+  this->ack_sent_();
+  return true;
+}
+
+// Sends the next queued frame not yet sent, and returns true if none are left. One frame per loop pass lets other
+// components run between frames: on a radio, sending blocks, and the peer's frames are received in between. If the
+// lower layer refuses the frame, it is sent again shortly.
+bool HdlcReliability::send_pending_() {
+  if (this->vn_ == this->vs_)
+    return true;
+  uint8_t control = (this->vn_ << 1) | (this->vr_ << 5);
+  if (!this->send_frame_(control, this->slot_(this->vn_), this->tx_lengths_[this->slot_index_(this->vn_)])) {
+    this->retry_send_();
+    return false;
+  }
+  // Every I-frame carries an acknowledgement, so a pending RR is no longer needed
+  this->ack_sent_();
+  this->vn_ = (this->vn_ + 1) & 7;
+  if (this->vn_ == this->vs_)
+    return true;
+  this->request_loop_();
+  return false;
+}
+
+void HdlcReliability::resend_outstanding_() {
+  this->vn_ = this->va_;
+  this->send_pending_();
+}
+
+void HdlcReliability::start_timer_() {
+  uint32_t interval = this->timeout_ms_;
+  if (this->state_ != LinkState::LINK_STATE_CONNECTED && interval < RESET_INTERVAL_MS)
+    interval = RESET_INTERVAL_MS;
+  // Up to a quarter longer at random, so devices whose frames collided on a shared channel do not resend together
+  interval += random_uint32() % (interval / 4 + 1);
+  this->set_timeout(RETRANSMIT_TIMER_ID, interval, [this]() { this->on_timeout_(); });
+}
+
+void HdlcReliability::on_timeout_() {
+  if (this->state_ != LinkState::LINK_STATE_CONNECTED) {
+    // Counted up to max_retries_ only, so the warning is logged once until the link comes up
+    if (this->retries_ < this->max_retries_) {
+      this->retries_++;
+      if (this->retries_ == this->max_retries_) {
+        ESP_LOGW(TAG, "%s: No answer to the link reset after %u tries; check that the peer has a reliability layer",
+                 this->name_, this->max_retries_);
+      }
+    }
+    this->send_frame_(UNNUMBERED_SABM, nullptr, 0);
+    this->start_timer_();
+    return;
+  }
+  if (this->outstanding_() == 0)
+    return;
+  if (this->retries_ == this->max_retries_) {
+    ESP_LOGW(TAG, "%s: No acknowledgement after %u retries, resetting link", this->name_, this->max_retries_);
+    this->start_reset_();
+    return;
+  }
+  this->retries_++;
+  ESP_LOGV(TAG, "%s: Timeout, resending %u frames", this->name_, this->outstanding_());
+  this->resend_outstanding_();
+  this->start_timer_();
+}
+
+// Unacknowledged frames are discarded; frames queued from now on are numbered from 0 and sent once the link is up.
+// Resetting a connected link can lose data both ways, which is reported to the layers above.
+void HdlcReliability::start_reset_() {
+  bool was_connected = this->state_ == LinkState::LINK_STATE_CONNECTED;
+  this->state_ = LinkState::LINK_STATE_RESET_PENDING;
+  this->va_ = this->vs_ = this->vn_ = 0;
+  this->head_ = 0;
+  this->vr_ = 0;
+  this->retries_ = 0;
+  this->rej_sent_ = false;
+  this->ack_sent_();
+  this->cancel_timeout(RETRANSMIT_TIMER_ID);
+  this->request_loop_();
+  if (was_connected)
+    this->session_callback_.call(false);
+}
+
+void HdlcReliability::link_up_() {
+  ESP_LOGD(TAG, "%s: Link connected", this->name_);
+  this->state_ = LinkState::LINK_STATE_CONNECTED;
+  this->reset_wait_logged_ = false;
+  this->peer_frame_seen_ = false;
+  this->retries_ = 0;
+  this->cancel_timeout(RETRANSMIT_TIMER_ID);
+  if (this->outstanding_() != 0) {
+    this->resend_outstanding_();
+    this->start_timer_();
+  }
+}
+
+void HdlcReliability::process_ack_(uint8_t nr) {
+  uint8_t acked = (nr - this->va_) & 7;
+  if (acked > this->outstanding_()) {
+    ESP_LOGV(TAG, "%s: Ignoring invalid N(R) %u", this->name_, nr);
+    return;
+  }
+  if (acked == 0)
+    return;
+  // The peer may have had frames that were refused when last resent
+  if (acked > ((this->vn_ - this->va_) & 7))
+    this->vn_ = nr;
+  this->head_ = (this->head_ + acked) % this->max_queue_length_;
+  this->va_ = nr;
+  this->retries_ = 0;
+  if (this->outstanding_() == 0) {
+    this->cancel_timeout(RETRANSMIT_TIMER_ID);
+  } else {
+    this->start_timer_();
+  }
+}
+
+void HdlcReliability::receive_(const PacketBuffer &data, const PacketMetaData &meta_data) {
+  // Lower layers deliver packets in one piece; the payload is passed up without copying
+  if (!data.is_contiguous()) {
+    ESP_LOGW(TAG, "%s: Packet split across buffers is not supported", this->name_);
+    return;
+  }
+  auto frame = data.as_span();
+  if (frame.size() < FRAME_OVERHEAD) {
+    this->note_received_(false);
+    return;
+  }
+  size_t length = frame.size() - FRAME_OVERHEAD;
+  uint8_t control = frame[0];
+  const uint8_t *payload = frame.data() + 1;
+  uint16_t crc = frame[length + 1] | (frame[length + 2] << 8);
+  if (frame_crc(control, payload, length) != crc) {
+    ESP_LOGV(TAG, "%s: CRC error, frame dropped", this->name_);
+    this->note_received_(false);
+    return;
+  }
+  // The peer's packets may only be larger if it has a larger max_packet_size, which the layers above cannot take
+  if (length > this->max_packet_size_) {
+    if (!this->oversize_warned_) {
+      this->oversize_warned_ = true;
+      ESP_LOGW(TAG,
+               "%s: Frame of %zu bytes is larger than %zu, dropped; check that both devices use the same "
+               "max_packet_size",
+               this->name_, length, this->max_packet_size_);
+    } else {
+      ESP_LOGV(TAG, "%s: Frame of %zu bytes is larger than %zu, dropped", this->name_, length, this->max_packet_size_);
+    }
+    this->note_received_(false);
+    return;
+  }
+  this->note_received_(true);
+
+  uint8_t command = control & ~POLL_FINAL_BIT;
+  if (command == UNNUMBERED_SABM) {
+    // A peer that has not heard our UA repeats its SABM, and cannot have sent a numbered frame meanwhile; answering
+    // again keeps this side connected, and the queued frames, instead of treating the repeat as a restart.
+    if (this->state_ == LinkState::LINK_STATE_CONNECTED && this->peer_frame_seen_) {
+      // The peer has restarted, so frames it has not acknowledged are lost
+      ESP_LOGD(TAG, "%s: Link reset by peer", this->name_);
+      this->start_reset_();
+    }
+    this->vr_ = 0;
+    this->rej_sent_ = false;
+    this->send_frame_(UNNUMBERED_UA, nullptr, 0);
+    // Both sides now start from 0, so the link is up even if our own SABM is unanswered
+    this->link_up_();
+    return;
+  }
+  if (command == UNNUMBERED_UA) {
+    if (this->state_ == LinkState::LINK_STATE_RESETTING)
+      this->link_up_();
+    return;
+  }
+  // Numbered frames are ignored until the link is reset; the peer answers our SABM first
+  if (this->state_ != LinkState::LINK_STATE_CONNECTED)
+    return;
+  this->peer_frame_seen_ = true;
+
+  uint8_t nr = control >> 5;
+  if ((control & 1) == 0) {
+    this->process_ack_(nr);
+    this->receive_info_(control, payload, length, meta_data);
+    return;
+  }
+  if ((control & 3) != SUPERVISORY_FRAME)
+    return;
+  this->process_ack_(nr);
+  if (((control >> 2) & 3) == SUPERVISORY_REJ && this->outstanding_() != 0) {
+    ESP_LOGV(TAG, "%s: Peer rejected from %u", this->name_, nr);
+    this->resend_outstanding_();
+    this->start_timer_();
+  }
+}
+
+void HdlcReliability::receive_info_(uint8_t control, const uint8_t *payload, size_t length,
+                                    const PacketMetaData &meta_data) {
+  uint8_t ns = (control >> 1) & 7;
+  if (ns != this->vr_) {
+    // A gap or a duplicate; ask once for a resend from the expected frame, then just acknowledge at once
+    if (!this->rej_sent_) {
+      this->rej_sent_ = this->send_supervisory_(SUPERVISORY_REJ);
+      if (this->rej_sent_)
+        return;
+    }
+    this->owe_ack_(true);
+    return;
+  }
+  this->vr_ = (this->vr_ + 1) & 7;
+  this->rej_sent_ = false;
+  // The acknowledgement is sent from loop(), so a reply sent from the callback can carry it instead
+  this->owe_ack_(false);
+  this->on_receive_from_interface_(PacketBuffer(payload, length), meta_data);
+}
+
+}  // namespace esphome::packet_interface
+#endif

esphome/components/packet_interface/hdlc_reliability.h

@@ -0,0 +1,99 @@
+#pragma once
+
+#include "esphome/core/defines.h"
+#ifdef USE_PACKET_INTERFACE_HDLC
+#include <array>
+
+#include "packet_interface.h"
+
+namespace esphome::packet_interface {
+
+/**
+ * A reliability layer that delivers packets in order, without loss or duplicates, between two peers.
+ *
+ * It follows HDLC asynchronous balanced mode, with sequence numbers modulo 8 and go-back-N retransmission:
+ * - I-frames carry a payload, the sequence number N(S) and an acknowledgement N(R) of the peer's frames.
+ * - RR frames acknowledge without a payload; REJ frames ask the peer to resend from N(R).
+ * - SABM resets both peers' sequence numbers, and UA answers it.
+ *
+ * Each frame is the HDLC control byte, the payload, then a CRC-16 of both in little endian order.
+ * Unacknowledged frames are resent after the timeout; after max_retries the link is reset.
+ */
+class HdlcReliability : public PacketInterface {
+ public:
+  /// Most frames that can be unacknowledged at once, set by the 3 bit sequence numbers.
+  static constexpr uint8_t MAX_WINDOW = 7;
+  /// Control byte plus CRC-16.
+  static constexpr size_t FRAME_OVERHEAD = 3;
+
+  explicit HdlcReliability(PacketInterface *lower);
+
+  void setup() override;
+  void loop() override;
+  void dump_config() override;
+  bool send_to_interface(const PacketBuffer &data, const PacketMetaData &meta_data) override;
+  /// No room while the layer has no send queue: before setup(), or when setup() failed.
+  size_t get_send_capacity() const override {
+    return this->tx_slots_ == nullptr ? 0 : this->max_queue_length_ - this->outstanding_();
+  }
+
+  void set_ack_timeout(uint32_t timeout_ms) { this->timeout_ms_ = timeout_ms; }
+  void set_ack_delay(uint32_t ack_delay_ms) { this->ack_delay_ms_ = ack_delay_ms; }
+  void set_max_queue_length(uint8_t length) { this->max_queue_length_ = length; }
+  void set_max_retries(uint8_t retries) { this->max_retries_ = retries; }
+
+  bool is_connected() const { return this->state_ == LinkState::LINK_STATE_CONNECTED; }
+
+ protected:
+  enum class LinkState : uint8_t {
+    LINK_STATE_RESET_PENDING,  // SABM to be sent from loop()
+    LINK_STATE_RESETTING,      // SABM sent, waiting for UA
+    LINK_STATE_CONNECTED,
+  };
+
+  void receive_(const PacketBuffer &data, const PacketMetaData &meta_data);
+  void receive_info_(uint8_t control, const uint8_t *payload, size_t length, const PacketMetaData &meta_data);
+  bool send_frame_(uint8_t control, const uint8_t *payload, size_t length);
+  bool send_supervisory_(uint8_t type);
+  bool send_pending_();
+  void resend_outstanding_();
+  void retry_send_();
+  /// An RR is owed: at once, or after the ack delay unless an I-frame carries it first.
+  void owe_ack_(bool now);
+  void ack_sent_();
+  void process_ack_(uint8_t nr);
+  void on_timeout_();
+  void start_reset_();
+  void link_up_();
+  void start_timer_();
+  void request_loop_();
+  uint8_t outstanding_() const { return (this->vs_ - this->va_) & 7; }
+  uint8_t slot_index_(uint8_t seq) const { return (this->head_ + ((seq - this->va_) & 7)) % this->max_queue_length_; }
+  uint8_t *slot_(uint8_t seq) { return this->tx_slots_ + this->slot_index_(seq) * this->max_packet_size_; }
+
+  PacketInterface *lower_;
+  // max_queue_length_ slots of max_packet_size_ bytes, a ring starting at head_ which holds frame va_; allocated in
+  // setup() and never freed
+  uint8_t *tx_slots_{nullptr};
+  std::array<uint16_t, MAX_WINDOW> tx_lengths_{};  // indexed like the slots
+  uint32_t timeout_ms_{200};
+  uint32_t ack_delay_ms_{0};
+  uint8_t max_queue_length_{4};
+  uint8_t max_retries_{5};
+  uint8_t retries_{0};
+  uint8_t head_{0};
+  uint8_t vs_{0};  // sequence number of the next new frame
+  uint8_t vn_{0};  // next frame to send; frames from va_ up to it have been sent
+  uint8_t va_{0};  // oldest unacknowledged frame
+  uint8_t vr_{0};  // next frame expected from the peer
+  LinkState state_{LinkState::LINK_STATE_RESET_PENDING};
+  bool ack_pending_{false};  // an RR is owed
+  bool ack_due_{false};      // and should be sent now
+  bool rej_sent_{false};
+  bool peer_frame_seen_{false};  // a numbered frame has arrived since the link came up
+  bool oversize_warned_{false};
+  bool reset_wait_logged_{false};  // the queue filled while waiting for this reset to be answered
+};
+
+}  // namespace esphome::packet_interface
+#endif

esphome/components/packet_interface/layers/__init__.py

@@ -0,0 +1,155 @@
+"""The kinds of layer that can be stacked on a packet interface, and the registry of their implementations.
+
+Each module in this package implements one layer type and registers it with its kind, for example:
+
+    @RELIABILITY.register("hdlc", schema=HDLC_SCHEMA)
+    async def build_hdlc(config: ConfigType, lower: MockObj) -> MockObj:
+        ...
+
+The packet_interface component imports every module here before it builds its schemas, so a new layer type needs
+only a new module. The kinds, and the order in which they are stacked, are fixed here.
+"""
+
+from collections.abc import Awaitable, Callable
+from dataclasses import dataclass
+from typing import Any
+
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.const import CONF_ENCRYPTION, CONF_KEY, CONF_TYPE
+from esphome.cpp_generator import MockObj
+from esphome.types import ConfigType
+
+packet_interface_ns = cg.esphome_ns.namespace("packet_interface")
+PacketInterface = packet_interface_ns.class_("PacketInterface", cg.Component)
+
+CONF_RELIABILITY = "reliability"
+CONF_SESSION = "session"
+
+# Builds a layer above lower and returns it
+LayerBuilder = Callable[[ConfigType, MockObj], Awaitable[Any]]
+
+
+def _never(config: ConfigType) -> bool:
+    return False
+
+
+def _nothing(config: ConfigType) -> list[str]:
+    return []
+
+
+@dataclass(frozen=True)
+class LayerType:
+    """One implementation of a kind of layer."""
+
+    schema: Any
+    build: LayerBuilder
+    # True if this configuration works only when the peer sends packets back, which a session layer makes sure of
+    needs_session: Callable[[ConfigType], bool]
+    # The components this configuration needs loaded
+    auto_load: Callable[[ConfigType], list[str]]
+
+
+class LayerKind:
+    """A kind of layer, such as encryption, with the types that implement it."""
+
+    def __init__(
+        self, key: str, default_type: str, shorthand: str | None = None
+    ) -> None:
+        self.key = key
+        self.default_type = default_type
+        # The option that a plain string value sets, as in `encryption: my key`
+        self.shorthand = shorthand
+        self.types: dict[str, LayerType] = {}
+        # Set once the schema is built, as types registered after that would not be in it
+        self.frozen = False
+
+    def register(
+        self,
+        name: str,
+        *,
+        schema: Any,
+        needs_session: Callable[[ConfigType], bool] = _never,
+        auto_load: Callable[[ConfigType], list[str]] = _nothing,
+    ) -> Callable[[LayerBuilder], LayerBuilder]:
+        """Register a type with its schema."""
+
+        def decorator(build: LayerBuilder) -> LayerBuilder:
+            if self.frozen:
+                raise ValueError(
+                    f"{self.key} layer type '{name}' is registered after the schemas were built; register it "
+                    "before the packet_interface component is imported"
+                )
+            if name in self.types:
+                raise ValueError(
+                    f"{self.key} layer type '{name}' is already registered"
+                )
+            self.types[name] = LayerType(schema, build, needs_session, auto_load)
+            return build
+
+        return decorator
+
+    def _expand(self, value: Any) -> Any:
+        """Allow a layer to be enabled with no options, as in `reliability:`, or with its shorthand."""
+        if value is None:
+            return {}
+        if self.shorthand is not None and isinstance(value, str):
+            return {self.shorthand: value}
+        return value
+
+    def schema(self) -> Callable[[Any], ConfigType]:
+        """The schema for this kind; no type can be registered after this."""
+        self.frozen = True
+        return cv.All(
+            self._expand,
+            cv.typed_schema(
+                {name: layer.schema for name, layer in self.types.items()},
+                default_type=self.default_type,
+            ),
+        )
+
+    def get_type(self, config: ConfigType) -> LayerType:
+        return self.types[config[CONF_TYPE]]
+
+
+ENCRYPTION = LayerKind(CONF_ENCRYPTION, "xxtea", shorthand=CONF_KEY)
+RELIABILITY = LayerKind(CONF_RELIABILITY, "hdlc")
+SESSION = LayerKind(CONF_SESSION, "basic")
+# The kinds stacked above the link, from the bottom up
+STACK_ORDER = (ENCRYPTION, RELIABILITY, SESSION)
+
+
+def stack_schema() -> dict:
+    """Schema entries for the layers of one stack; call only once all layer types are registered."""
+    return {cv.Optional(kind.key): kind.schema() for kind in STACK_ORDER}
+
+
+def check_session(config: ConfigType) -> None:
+    """Layers that need packets back from the peer need a session layer, whose keep-alives send them."""
+    if CONF_SESSION in config:
+        return
+    for kind in STACK_ORDER:
+        if (layer := config.get(kind.key)) is not None and kind.get_type(
+            layer
+        ).needs_session(layer):
+            raise cv.Invalid(
+                f"This '{kind.key}' needs packets from the peer, so it needs a '{CONF_SESSION}' layer, whose "
+                "keep-alives make sure they are sent",
+                path=[kind.key],
+            )
+
+
+def stack_auto_load(config: ConfigType) -> set[str]:
+    """The components that the layers configured in config need loaded."""
+    loads: set[str] = set()
+    for kind in STACK_ORDER:
+        if (layer := config.get(kind.key)) is not None:
+            loads.update(kind.get_type(layer).auto_load(layer))
+    return loads
+
+
+async def build_stack(config: ConfigType, lower: MockObj) -> None:
+    """Create the layers configured in config, from the bottom up, above lower."""
+    for kind in STACK_ORDER:
+        if (layer := config.get(kind.key)) is not None:
+            lower = await kind.get_type(layer).build(layer, lower)

esphome/components/packet_interface/layers/basic_session.py

@@ -0,0 +1,70 @@
+"""Session layer that sends keep-alives and reports whether the peer can be reached."""
+
+import esphome.codegen as cg
+from esphome.components import binary_sensor
+import esphome.config_validation as cv
+from esphome.const import (
+    CONF_BINARY_SENSOR,
+    CONF_ID,
+    CONF_TIMEOUT,
+    DEVICE_CLASS_CONNECTIVITY,
+    ENTITY_CATEGORY_DIAGNOSTIC,
+)
+from esphome.cpp_generator import MockObj
+from esphome.types import ConfigType
+
+from . import SESSION, PacketInterface, packet_interface_ns
+
+CONF_KEEP_ALIVE = "keep_alive"
+
+BasicSession = packet_interface_ns.class_("BasicSession", PacketInterface)
+
+
+def _session_timeout(config: ConfigType) -> ConfigType:
+    """Default the timeout to three keep-alive intervals, and require it to be longer than one."""
+    keep_alive = config[CONF_KEEP_ALIVE].total_milliseconds
+    if (timeout := config.get(CONF_TIMEOUT)) is None:
+        config[CONF_TIMEOUT] = cv.positive_time_period_milliseconds(
+            f"{keep_alive * 3}ms"
+        )
+    elif timeout.total_milliseconds <= keep_alive:
+        raise cv.Invalid("Must be longer than keep_alive", path=[CONF_TIMEOUT])
+    return config
+
+
+BASIC_SESSION_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(BasicSession),
+            cv.Optional(CONF_KEEP_ALIVE, default="10s"): cv.All(
+                cv.positive_time_period_milliseconds,
+                cv.Range(min=cv.TimePeriod(seconds=1), max=cv.TimePeriod(hours=1)),
+            ),
+            cv.Optional(CONF_TIMEOUT): cv.All(
+                cv.positive_time_period_milliseconds,
+                cv.Range(max=cv.TimePeriod(hours=3)),
+            ),
+            cv.Optional(CONF_BINARY_SENSOR): binary_sensor.binary_sensor_schema(
+                device_class=DEVICE_CLASS_CONNECTIVITY,
+                entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+            ),
+        }
+    ).extend(cv.COMPONENT_SCHEMA),
+    _session_timeout,
+)
+
+
+@SESSION.register(
+    "basic",
+    schema=BASIC_SESSION_SCHEMA,
+    auto_load=lambda config: ["binary_sensor"] if CONF_BINARY_SENSOR in config else [],
+)
+async def build_basic_session(config: ConfigType, lower: MockObj) -> MockObj:
+    cg.add_define("USE_PACKET_INTERFACE_BASIC_SESSION")
+    var = cg.new_Pvariable(config[CONF_ID], lower)
+    cg.add(var.set_keep_alive(config[CONF_KEEP_ALIVE]))
+    cg.add(var.set_session_timeout(config[CONF_TIMEOUT]))
+    await cg.register_component(var, config)
+    binary_sensors = binary_sensor.sub_binary_sensors(config)
+    await binary_sensors(CONF_BINARY_SENSOR, var.set_connected_sensor)
+    return var

esphome/components/packet_interface/layers/hdlc_reliability.py

@@ -0,0 +1,59 @@
+"""Reliability layer using HDLC style acknowledgement and go-back-N retransmission."""
+
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.const import CONF_ID, CONF_TIMEOUT
+from esphome.cpp_generator import MockObj
+from esphome.types import ConfigType
+
+from . import RELIABILITY, PacketInterface, packet_interface_ns
+
+CONF_ACK_DELAY = "ack_delay"
+CONF_MAX_QUEUE_LENGTH = "max_queue_length"
+CONF_MAX_RETRIES = "max_retries"
+
+HdlcReliability = packet_interface_ns.class_("HdlcReliability", PacketInterface)
+
+
+def _ack_delay_within_timeout(config: ConfigType) -> ConfigType:
+    """The peer, configured the same, must hear the acknowledgement before its timeout."""
+    if (
+        config[CONF_ACK_DELAY].total_milliseconds
+        >= config[CONF_TIMEOUT].total_milliseconds
+    ):
+        raise cv.Invalid(
+            f"Must be shorter than '{CONF_TIMEOUT}'", path=[CONF_ACK_DELAY]
+        )
+    return config
+
+
+HDLC_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(HdlcReliability),
+            # Retransmitting more often than the main loop runs would exhaust the retries at once
+            cv.Optional(CONF_TIMEOUT, default="200ms"): cv.All(
+                cv.positive_time_period_milliseconds,
+                cv.Range(min=cv.TimePeriod(milliseconds=50)),
+            ),
+            cv.Optional(
+                CONF_ACK_DELAY, default="0ms"
+            ): cv.positive_time_period_milliseconds,
+            cv.Optional(CONF_MAX_QUEUE_LENGTH, default=4): cv.int_range(1, 7),
+            cv.Optional(CONF_MAX_RETRIES, default=5): cv.int_range(1, 255),
+        }
+    ).extend(cv.COMPONENT_SCHEMA),
+    _ack_delay_within_timeout,
+)
+
+
+@RELIABILITY.register("hdlc", schema=HDLC_SCHEMA)
+async def build_hdlc(config: ConfigType, lower: MockObj) -> MockObj:
+    cg.add_define("USE_PACKET_INTERFACE_HDLC")
+    var = cg.new_Pvariable(config[CONF_ID], lower)
+    cg.add(var.set_ack_timeout(config[CONF_TIMEOUT]))
+    cg.add(var.set_ack_delay(config[CONF_ACK_DELAY]))
+    cg.add(var.set_max_queue_length(config[CONF_MAX_QUEUE_LENGTH]))
+    cg.add(var.set_max_retries(config[CONF_MAX_RETRIES]))
+    await cg.register_component(var, config)
+    return var

esphome/components/packet_interface/layers/xxtea_encryption.py

@@ -0,0 +1,50 @@
+"""Encryption layer using XXTEA, with an optional rolling code."""
+
+import hashlib
+
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.const import CONF_ID, CONF_KEY
+from esphome.cpp_generator import MockObj
+from esphome.types import ConfigType
+
+from . import ENCRYPTION, PacketInterface, packet_interface_ns
+
+CONF_ROLLING_CODE_ENABLE = "rolling_code_enable"
+
+# A captured packet lets a guessed key be checked offline, so the key text is stretched to make each guess costly.
+# Both ends derive the same key from the same text, so the salt is fixed; it keeps tables built for other uses of
+# PBKDF2 from applying here.
+KEY_SALT = b"esphome packet_interface xxtea"
+KEY_ITERATIONS = 600_000
+
+XxteaEncryption = packet_interface_ns.class_("XxteaEncryption", PacketInterface)
+
+XXTEA_SCHEMA = cv.Schema(
+    {
+        cv.GenerateID(): cv.declare_id(XxteaEncryption),
+        cv.Required(CONF_KEY): cv.All(cv.sensitive(cv.string), cv.Length(min=1)),
+        cv.Optional(CONF_ROLLING_CODE_ENABLE, default=False): cv.boolean,
+    }
+).extend(cv.COMPONENT_SCHEMA)
+
+
+def derive_key(text: str) -> list[int]:
+    """The 256-bit key for the key text, as 32-bit words in little endian order."""
+    digest = hashlib.pbkdf2_hmac("sha256", text.encode(), KEY_SALT, KEY_ITERATIONS)
+    return [int.from_bytes(digest[i : i + 4], "little") for i in range(0, 32, 4)]
+
+
+@ENCRYPTION.register(
+    "xxtea",
+    schema=XXTEA_SCHEMA,
+    # The rolling code accepts a packet only once the peer has sent back this device's boot number
+    needs_session=lambda config: config[CONF_ROLLING_CODE_ENABLE],
+    auto_load=lambda config: ["xxtea"],
+)
+async def build_xxtea(config: ConfigType, lower: MockObj) -> MockObj:
+    cg.add_define("USE_PACKET_INTERFACE_XXTEA")
+    var = cg.new_Pvariable(config[CONF_ID], lower, config[CONF_ROLLING_CODE_ENABLE])
+    cg.add(var.set_key(derive_key(config[CONF_KEY])))
+    await cg.register_component(var, config)
+    return var

esphome/components/packet_interface/xxtea_encryption.cpp

@@ -0,0 +1,182 @@
+#include "xxtea_encryption.h"
+#ifdef USE_PACKET_INTERFACE_XXTEA
+#include <algorithm>
+#include <cstring>
+#include "esphome/components/xxtea/xxtea.h"
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
+
+namespace esphome::packet_interface {
+
+ESPHOME_LOG_TAG(TAG, "packet_interface.xxtea");
+
+static constexpr uint32_t PREF_HASH = fnv1a_hash("packet_interface.xxtea");
+// Different for each mode, so devices set up differently drop each other's packets
+static constexpr uint8_t CHECK_BYTES[3] = {0x58, 0x54, 0x45};
+static constexpr uint8_t ROLLING_CHECK_BYTES[3] = {0x58, 0x54, 0x52};
+static constexpr size_t CHECK_SIZE = 4;
+// Boot number, counter, and the echo of the receiver's boot number
+static constexpr size_t ROLLING_SIZE = 12;
+// XXTEA needs at least two words
+static constexpr size_t MIN_LENGTH = 8;
+static constexpr size_t MAX_PADDING = 4;
+
+static void put_uint32(uint8_t *buf, uint32_t value) {
+  buf[0] = value;
+  buf[1] = value >> 8;
+  buf[2] = value >> 16;
+  buf[3] = value >> 24;
+}
+
+static uint32_t get_uint32(const uint8_t *buf) { return encode_uint32(buf[3], buf[2], buf[1], buf[0]); }
+
+static constexpr size_t trailer_size(bool rolling_code) {
+  return rolling_code ? ROLLING_SIZE + CHECK_SIZE : CHECK_SIZE;
+}
+
+XxteaEncryption::XxteaEncryption(PacketInterface *lower, bool rolling_code)
+    // XXTEA works on whole 32-bit words
+    : PacketInterface(remaining_packet_size(lower->get_max_packet_size() & ~size_t{3}, trailer_size(rolling_code))),
+      lower_(lower),
+      trailer_size_(trailer_size(rolling_code)),
+      rolling_code_(rolling_code) {
+  this->stack_on_(lower, CAPABILITY_ENCRYPTION);
+}
+
+void XxteaEncryption::set_key(std::initializer_list<uint32_t> key) {
+  std::copy_n(key.begin(), std::min(key.size(), this->key_.size()), this->key_.begin());
+}
+
+void XxteaEncryption::setup() {
+  if (this->max_packet_size_ == 0) {
+    this->mark_failed(LOG_STR("max_packet_size too small for the configured layers"));
+    return;
+  }
+  size_t words = this->lower_->get_max_packet_size() / 4;
+  RAMAllocator<uint32_t> allocator;
+  this->tx_buffer_ = allocator.allocate(words * 2);
+  if (this->tx_buffer_ == nullptr) {
+    this->mark_failed(LOG_STR("Not enough memory for the packet buffers"));
+    return;
+  }
+  this->rx_buffer_ = this->tx_buffer_ + words;
+  if (this->rolling_code_) {
+    this->pref_ = global_preferences->make_preference<uint32_t>(fnv1a_hash_extend(PREF_HASH, this->name_), true);
+    this->pref_.load(&this->boot_);
+    this->next_boot_();
+  }
+  this->lower_->add_packet_interface_listener(
+      [this](const PacketBuffer &data, const PacketMetaData &meta_data) { this->receive_(data, meta_data); });
+}
+
+void XxteaEncryption::dump_config() {
+  ESP_LOGCONFIG(TAG,
+                "XXTEA Encryption on '%s':\n"
+                "  Max Packet Size: %zu\n"
+                "  Rolling Code: %s",
+                this->name_, this->max_packet_size_, YESNO(this->rolling_code_));
+  if (this->rolling_code_) {
+    ESP_LOGCONFIG(TAG, "  Boot Number: %" PRIu32, this->boot_);
+  }
+}
+
+// A new boot number must be saved before it is used, or a crash could make the peer see it again
+void XxteaEncryption::next_boot_() {
+  this->boot_++;
+  this->counter_ = 0;
+  if (!this->pref_.save(&this->boot_) || !global_preferences->sync()) {
+    ESP_LOGW(TAG, "%s: Could not save the boot number, so a restart could reuse it", this->name_);
+  }
+}
+
+bool XxteaEncryption::send_to_interface(const PacketBuffer &data, const PacketMetaData &meta_data) {
+  if (this->tx_buffer_ == nullptr)
+    return false;
+  size_t size = data.size();
+  if (size > this->max_packet_size_) {
+    ESP_LOGW(TAG, "%s: Packet of %zu bytes is larger than %zu", this->name_, size, this->max_packet_size_);
+    return false;
+  }
+  size_t padding = (4 - (size + this->trailer_size_) % 4) % 4;
+  if (size + padding + this->trailer_size_ < MIN_LENGTH)
+    padding += 4;
+  size_t length = size + padding + this->trailer_size_;
+  auto *buf = reinterpret_cast<uint8_t *>(this->tx_buffer_);
+  data.copy_to(buf, size);
+  memset(buf + size, 0, padding);
+  uint8_t *check = buf + length - CHECK_SIZE;
+  if (this->rolling_code_) {
+    put_uint32(check - ROLLING_SIZE, this->boot_);
+    put_uint32(check - ROLLING_SIZE + 4, this->counter_);
+    put_uint32(check - ROLLING_SIZE + 8, this->echo_boot_);
+    memcpy(check, ROLLING_CHECK_BYTES, sizeof(ROLLING_CHECK_BYTES));
+    if (++this->counter_ == 0)
+      this->next_boot_();
+  } else {
+    memcpy(check, CHECK_BYTES, sizeof(CHECK_BYTES));
+  }
+  check[CHECK_SIZE - 1] = padding;
+  xxtea::encrypt(this->tx_buffer_, length / 4, this->key_.data());
+  return this->lower_->send_to_interface(PacketBuffer(buf, length), meta_data);
+}
+
+bool XxteaEncryption::accept_counter_(uint32_t boot, uint32_t counter) {
+  if (this->peer_seen_ && (boot < this->peer_boot_ || (boot == this->peer_boot_ && counter <= this->peer_counter_)))
+    return false;
+  this->peer_seen_ = true;
+  this->peer_boot_ = boot;
+  this->peer_counter_ = counter;
+  return true;
+}
+
+void XxteaEncryption::receive_(const PacketBuffer &data, const PacketMetaData &meta_data) {
+  size_t length = data.size();
+  if (length % 4 != 0 || length < std::max(MIN_LENGTH, this->trailer_size_) ||
+      length > this->lower_->get_max_packet_size()) {
+    ESP_LOGV(TAG, "%s: Packet of %zu bytes dropped", this->name_, length);
+    this->note_received_(false);
+    return;
+  }
+  auto *buf = reinterpret_cast<uint8_t *>(this->rx_buffer_);
+  data.copy_to(buf, length);
+  xxtea::decrypt(this->rx_buffer_, length / 4, this->key_.data());
+  const uint8_t *check = buf + length - CHECK_SIZE;
+  const uint8_t *expected = this->rolling_code_ ? ROLLING_CHECK_BYTES : CHECK_BYTES;
+  size_t padding = check[CHECK_SIZE - 1];
+  if (memcmp(check, expected, sizeof(CHECK_BYTES)) != 0 || padding > MAX_PADDING ||
+      padding > length - this->trailer_size_) {
+    ESP_LOGV(TAG, "%s: Packet failed authentication", this->name_);
+    this->note_received_(false);
+    return;
+  }
+  this->note_received_(true);
+  if (this->rolling_code_) {
+    uint32_t boot = get_uint32(check - ROLLING_SIZE);
+    uint32_t counter = get_uint32(check - ROLLING_SIZE + 4);
+    uint32_t echo = get_uint32(check - ROLLING_SIZE + 8);
+    // Learn the peer's boot number even from a packet that is then dropped, so both sides can catch up
+    if (boot > this->echo_boot_)
+      this->echo_boot_ = boot;
+    // A packet recorded before this boot cannot carry this boot's number
+    if (echo != this->boot_) {
+      ESP_LOGV(TAG, "%s: Packet for boot %" PRIu32 " dropped", this->name_, echo);
+      return;
+    }
+    if (!this->accept_counter_(boot, counter)) {
+      // A boot number lower than one already heard means the peer lost its saved boot number, or a replay
+      if (boot < this->peer_boot_ && !this->old_boot_warned_) {
+        this->old_boot_warned_ = true;
+        ESP_LOGW(TAG,
+                 "%s: Packets from an older boot %" PRIu32 " of the peer are dropped; if its flash was erased, "
+                 "restart this device",
+                 this->name_, boot);
+      }
+      ESP_LOGV(TAG, "%s: Old packet %" PRIu32 ":%" PRIu32 " dropped", this->name_, boot, counter);
+      return;
+    }
+  }
+  this->on_receive_from_interface_(PacketBuffer(buf, length - this->trailer_size_ - padding), meta_data);
+}
+
+}  // namespace esphome::packet_interface
+#endif

esphome/components/packet_interface/xxtea_encryption.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include "esphome/core/defines.h"
+#ifdef USE_PACKET_INTERFACE_XXTEA
+#include <array>
+#include <initializer_list>
+
+#include "esphome/core/preferences.h"
+#include "packet_interface.h"
+
+namespace esphome::packet_interface {
+
+/**
+ * An encryption layer that encrypts and authenticates each packet with XXTEA and a 256-bit shared key.
+ *
+ * The packet is padded with zeros and followed by a trailer, then the whole is encrypted as one block. With the
+ * rolling code enabled, the trailer starts with:
+ * - a 32-bit boot number, saved in flash and increased at every boot;
+ * - a 32-bit packet counter, starting at 0 at every boot;
+ * - the highest boot number heard from the peer, echoed back to it.
+ * The trailer always ends with 3 fixed check bytes and the number of padding bytes. XXTEA mixes the whole block, so
+ * a packet that was changed or encrypted with another key fails the check.
+ * With the rolling code, a packet is dropped as a replay unless it echoes this device's current boot number, and its
+ * boot number and counter are higher than those of the last packet accepted from the peer. A boot number is never
+ * reused, so the echo acts as a fresh challenge after every restart.
+ */
+class XxteaEncryption : public PacketInterface {
+ public:
+  XxteaEncryption(PacketInterface *lower, bool rolling_code);
+
+  void setup() override;
+  void dump_config() override;
+  bool send_to_interface(const PacketBuffer &data, const PacketMetaData &meta_data) override;
+
+  void set_key(std::initializer_list<uint32_t> key);
+
+ protected:
+  void receive_(const PacketBuffer &data, const PacketMetaData &meta_data);
+  bool accept_counter_(uint32_t boot, uint32_t counter);
+  void next_boot_();
+
+  PacketInterface *lower_;
+  const size_t trailer_size_;
+  std::array<uint32_t, 8> key_{};
+  // Separate buffers, as a layer above may send a reply while a received packet is being passed up; both are in one
+  // block allocated in setup(), and tx_buffer_ stays null if that fails
+  uint32_t *tx_buffer_{nullptr};
+  uint32_t *rx_buffer_{nullptr};
+  ESPPreferenceObject pref_;
+  uint32_t boot_{0};
+  uint32_t counter_{0};
+  uint32_t peer_boot_{0};
+  uint32_t peer_counter_{0};
+  uint32_t echo_boot_{0};  // highest boot number heard from the peer
+  bool peer_seen_{false};
+  bool old_boot_warned_{false};
+  const bool rolling_code_;
+};
+
+}  // namespace esphome::packet_interface
+#endif

esphome/components/runtime_image/bmp_decoder.cpp

@@ -3,6 +3,7 @@
 #ifdef USE_RUNTIME_IMAGE_BMP
 
 #include "esphome/components/display/display.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
@@ -12,6 +13,9 @@ namespace esphome::runtime_image {
 
 ESPHOME_LOG_TAG(TAG, "image_decoder.bmp");
 
+// BMP has no alpha. Every pixel is drawn opaque, or a transparent image would hide it
+static constexpr Color OPAQUE_BLACK(0, 0, 0, 0xFF);
+
 void BmpDecoder::reset() {
   ImageDecoder::reset();
   this->bits_per_pixel_ = 0;
@@ -142,23 +146,31 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
     this->current_index_ = this->data_offset_;
     index = this->data_offset_;
   }
+  // A call that has run for DECODE_TIME_LIMIT_MS stops, and the caller passes the rest again later
+  const uint32_t start = millis();
+  uint32_t steps = 0;
+  auto out_of_time = [start, &steps]() {
+    return ++steps % DECODE_TIME_CHECK_STEPS == 0 && millis() - start >= DECODE_TIME_LIMIT_MS;
+  };
+  // Bytes after the last pixel are used up without drawing anything
+  const size_t total_pixels = static_cast<size_t>(this->width_) * this->height_;
   switch (this->bits_per_pixel_) {
     case 1: {
       size_t width = static_cast<size_t>(this->width_);
-      while (index < size) {
+      while (index < size && this->paint_index_ < total_pixels) {
         size_t x = this->paint_index_ % width;
         size_t y = static_cast<size_t>(this->height_ - 1) - (this->paint_index_ / width);
         size_t remaining_in_row = width - x;
         uint8_t pixels_in_byte = std::min<size_t>(remaining_in_row, 8);
         bool end_of_row = remaining_in_row <= 8;
         size_t needed = 1 + (end_of_row ? this->padding_bytes_ : 0);
-        if (index + needed > size) {
+        if (index + needed > size || out_of_time()) {
           this->decoded_bytes_ += index;
           return index;
         }
         uint8_t current_byte = buffer[index];
         for (uint8_t i = 0; i < pixels_in_byte; i++) {
-          Color c = (current_byte & (1 << (7 - i))) ? display::COLOR_ON : display::COLOR_OFF;
+          Color c = (current_byte & (1 << (7 - i))) ? display::COLOR_ON : OPAQUE_BLACK;
           this->draw(x + i, y, 1, 1, c);
         }
         this->paint_index_ += pixels_in_byte;
@@ -175,11 +187,11 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
     case 8: {
       size_t width = static_cast<size_t>(this->width_);
       size_t last_col = width - 1;
-      while (index < size) {
+      while (index < size && this->paint_index_ < total_pixels) {
         size_t x = this->paint_index_ % width;
         size_t y = static_cast<size_t>(this->height_ - 1) - (this->paint_index_ / width);
         size_t needed = 1 + ((x == last_col) ? this->padding_bytes_ : 0);
-        if (index + needed > size) {
+        if (index + needed > size || out_of_time()) {
           this->decoded_bytes_ += index;
           return index;
         }
@@ -194,7 +206,7 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
         uint8_t b = rgb & 0xff;
         uint8_t g = (rgb >> 8) & 0xff;
         uint8_t r = (rgb >> 16) & 0xff;
-        this->draw(x, y, 1, 1, Color(r, g, b));
+        this->draw(x, y, 1, 1, Color(r, g, b, 0xFF));
         this->paint_index_++;
         this->current_index_++;
         index++;
@@ -208,18 +220,18 @@ int HOT BmpDecoder::decode(uint8_t *buffer, size_t size) {
     case 24: {
       size_t width = static_cast<size_t>(this->width_);
       size_t last_col = width - 1;
-      while (index < size) {
+      while (index < size && this->paint_index_ < total_pixels) {
         size_t x = this->paint_index_ % width;
         size_t y = static_cast<size_t>(this->height_ - 1) - (this->paint_index_ / width);
         size_t needed = 3 + ((x == last_col) ? this->padding_bytes_ : 0);
-        if (index + needed > size) {
+        if (index + needed > size || out_of_time()) {
           this->decoded_bytes_ += index;
           return index;
         }
         uint8_t b = buffer[index];
         uint8_t g = buffer[index + 1];
         uint8_t r = buffer[index + 2];
-        this->draw(x, y, 1, 1, Color(r, g, b));
+        this->draw(x, y, 1, 1, Color(r, g, b, 0xFF));
         this->paint_index_++;
         this->current_index_ += 3;
         index += 3;

esphome/components/runtime_image/image_decoder.cpp

@@ -1,29 +1,106 @@
 #include "image_decoder.h"
 #include "runtime_image.h"
+#include "esphome/components/display/display_color_utils.h"
 #include "esphome/core/log.h"
 #include <algorithm>
-#include <cmath>
 
 namespace esphome::runtime_image {
 
 ESPHOME_LOG_TAG(TAG, "image_decoder");
 
 bool ImageDecoder::set_size(int width, int height) {
-  bool success = this->image_->resize(width, height) > 0;
-  this->size_valid_ = success;
-  this->x_scale_ = static_cast<double>(this->image_->get_buffer_width()) / width;
-  this->y_scale_ = static_cast<double>(this->image_->get_buffer_height()) / height;
-  return success;
+  if (!this->resize_image_(width, height))
+    return false;
+  this->prepare_draw_(width, height);
+  return true;
+}
+
+bool ImageDecoder::resize_image_(int width, int height) {
+  this->size_valid_ = this->image_->resize(width, height) > 0;
+  return this->size_valid_;
+}
+
+void ImageDecoder::prepare_draw_(int width, int height) {
+  this->draw_width_ = width;
+  this->draw_height_ = height;
+  this->direct_rgb565_ = this->image_->get_type() == image::IMAGE_TYPE_RGB565 && !this->image_->has_transparency();
+  if (!this->direct_rgb565_)
+    return;
+  if ((this->x_boundaries_.capacity() < static_cast<size_t>(width + 1) && !this->x_boundaries_.try_init(width + 1)) ||
+      (this->y_boundaries_.capacity() < static_cast<size_t>(height + 1) && !this->y_boundaries_.try_init(height + 1))) {
+    ESP_LOGW(TAG, "No memory to draw straight into the buffer; drawing pixel by pixel");
+    this->direct_rgb565_ = false;
+    // Free the table that did fit, as nothing uses it
+    this->x_boundaries_.release();
+    this->y_boundaries_.release();
+    return;
+  }
+  this->x_boundaries_.clear();
+  this->y_boundaries_.clear();
+  const int buffer_width = this->image_->get_buffer_width();
+  const int buffer_height = this->image_->get_buffer_height();
+  // The same boundaries as draw() uses, so both paths paint the same pixels
+  for (int x = 0; x <= width; x++) {
+    this->x_boundaries_.push_back(static_cast<uint16_t>(scale_boundary(x, width, buffer_width)));
+  }
+  for (int y = 0; y <= height; y++) {
+    this->y_boundaries_.push_back(static_cast<uint16_t>(scale_boundary(y, height, buffer_height)));
+  }
+}
+
+void ImageDecoder::draw_rgb565_(int x, int y, int w, int h, uint16_t rgb565) {
+  const int x_end = std::min(x + w, this->draw_width_);
+  const int y_end = std::min(y + h, this->draw_height_);
+  x = std::max(x, 0);
+  y = std::max(y, 0);
+  if (x >= x_end || y >= y_end)
+    return;
+  // A block of source pixels lands on one block of the buffer
+  const uint16_t x1 = this->x_boundaries_[x];
+  const uint16_t x2 = this->x_boundaries_[x_end];
+  const uint16_t y1 = this->y_boundaries_[y];
+  const uint16_t y2 = this->y_boundaries_[y_end];
+  const bool big_endian = this->image_is_big_endian_();
+  const uint8_t first = big_endian ? rgb565 >> 8 : rgb565 & 0xFF;
+  const uint8_t second = big_endian ? rgb565 & 0xFF : rgb565 >> 8;
+  uint8_t *const buffer = this->image_buffer_();
+  const uint32_t buffer_width = this->image_->get_buffer_width();
+  for (uint32_t row = y1; row < y2; row++) {
+    uint8_t *destination = buffer + (row * buffer_width + x1) * 2;
+    for (uint32_t col = x1; col < x2; col++) {
+      destination[0] = first;
+      destination[1] = second;
+      destination += 2;
+    }
+  }
 }
 
 void ImageDecoder::draw(int x, int y, int w, int h, const Color &color) {
   if (!this->size_valid_) {
     return;
   }
-  auto width = std::min(this->image_->get_buffer_width(), static_cast<int>(std::ceil((x + w) * this->x_scale_)));
-  auto height = std::min(this->image_->get_buffer_height(), static_cast<int>(std::ceil((y + h) * this->y_scale_)));
-  for (int i = x * this->x_scale_; i < width; i++) {
-    for (int j = y * this->y_scale_; j < height; j++) {
+  if (this->direct_rgb565_) {
+    this->draw_rgb565_(x, y, w, h, display::ColorUtil::color_to_565(color));
+    return;
+  }
+  // When shrinking, each target pixel is painted once, by the first source pixel that reaches it, rather than by every
+  // pixel that lands on it. Integer maths: the S3 has no double FPU.
+  const int buffer_width = this->image_->get_buffer_width();
+  const int buffer_height = this->image_->get_buffer_height();
+  int x1 = x;
+  int y1 = y;
+  int x2 = x + w;
+  int y2 = y + h;
+  if (buffer_width != this->draw_width_ || buffer_height != this->draw_height_) {
+    x1 = scale_boundary(x, this->draw_width_, buffer_width);
+    y1 = scale_boundary(y, this->draw_height_, buffer_height);
+    x2 = scale_boundary(x + w, this->draw_width_, buffer_width);
+    y2 = scale_boundary(y + h, this->draw_height_, buffer_height);
+  }
+  x2 = std::min(buffer_width, x2);
+  y2 = std::min(buffer_height, y2);
+  for (int i = x1; i < x2; i++) {
+    for (int j = y1; j < y2; j++) {
       this->image_->draw_pixel(i, j, color);
     }
   }

esphome/components/runtime_image/image_decoder.h

@@ -2,10 +2,20 @@
 #include <cstdint>
 
 #include "esphome/core/color.h"
+#include "esphome/core/helpers.h"
 #include "image_format.h"
 
 namespace esphome::runtime_image {
 
+/// The first of `target` pixels that pixel n of `source` paints, rounded up: ceil(n * target / source). The spans of
+/// neighbouring pixels meet without overlapping, so a shrunk image paints each target pixel once.
+inline int scale_boundary(int n, int source, int target) {
+  if (source <= 0)
+    return 0;
+  return static_cast<int>((static_cast<uint32_t>(n) * static_cast<uint32_t>(target) + source - 1) /
+                          static_cast<uint32_t>(source));
+}
+
 enum DecodeError : int {
   DECODE_ERROR_INVALID_TYPE = -1,
   DECODE_ERROR_UNSUPPORTED_FORMAT = -2,
@@ -38,6 +48,11 @@ constexpr const char *decode_error_to_string(int error) {
   }
 }
 
+// The longest one decode() call works before it returns, leaving the rest of the data for the next call
+static constexpr uint32_t DECODE_TIME_LIMIT_MS = 15;
+// Pixel loops read the clock once per this many steps
+static constexpr uint32_t DECODE_TIME_CHECK_STEPS = 64;
+
 class RuntimeImage;
 
 /// Input that a decoder reads itself as it goes, so the whole image never has to be in memory at once
@@ -83,8 +98,9 @@ class ImageDecoder {
     this->expected_size_ = 0;
     this->decoded_bytes_ = 0;
     this->size_valid_ = true;
-    this->x_scale_ = 1.0;
-    this->y_scale_ = 1.0;
+    this->draw_width_ = 0;
+    this->draw_height_ = 0;
+    this->direct_rgb565_ = false;
   }
 
   /**
@@ -179,19 +195,37 @@ class ImageDecoder {
   /// Whether is_finished() can tell a complete image from a cut-off one
   virtual bool knows_end() const { return this->expected_size_ > 0; }
 
+  /// The image is opaque RGB565, so draw() writes it straight into the buffer
+  bool uses_direct_rgb565() const { return this->direct_rgb565_; }
+
  protected:
+  /// Resize the image for a width x height source, without preparing to draw. prepare_draw_() must follow.
+  bool resize_image_(int width, int height);
+  /**
+   * Draw a source of width x height over the whole buffer from now on. For an opaque RGB565 image this builds the
+   * tables of where each source column and row lands; without the memory for them it draws pixel by pixel instead.
+   */
+  void prepare_draw_(int width, int height);
+  /// Paint a block of source pixels in one color straight into the buffer. Only while uses_direct_rgb565().
+  void draw_rgb565_(int x, int y, int w, int h, uint16_t rgb565);
+
   /// The image's pixel buffer, for decoders that write their output straight into it
   uint8_t *image_buffer_() const;
   bool image_is_big_endian_() const;
 
-  double x_scale_ = 1.0;
-  double y_scale_ = 1.0;
+  // Size of the image as the decoder draws it, which draw() spreads over the buffer
+  int draw_width_ = 0;
+  int draw_height_ = 0;
+  // Boundary n is the first buffer column, or row, that source column, or row, n paints
+  FixedVector<uint16_t> x_boundaries_{};
+  FixedVector<uint16_t> y_boundaries_{};
   RuntimeImage *image_;
   size_t expected_size_ = 0;  // Expected data size (0 if unknown)
   size_t decoded_bytes_ = 0;  // Bytes processed so far
   const ImageFormat format_;
   bool active_ = false;     // A decoding session is in progress
   bool size_valid_ = true;  // Last set_size() result; draw() no-ops while false
+  bool direct_rgb565_ = false;
 };
 
 }  // namespace esphome::runtime_image

esphome/components/runtime_image/jpeg_decoder.cpp

@@ -16,32 +16,6 @@ ESPHOME_LOG_TAG(TAG, "image_decoder.jpeg");
 
 namespace esphome::runtime_image {
 
-bool JpegDecoder::prepare_rgb565_scaling_(int width, int height) {
-  if (this->x_boundaries_.capacity() < static_cast<size_t>(width + 1) && !this->x_boundaries_.try_init(width + 1)) {
-    return false;
-  }
-  if (this->y_boundaries_.capacity() < static_cast<size_t>(height + 1) && !this->y_boundaries_.try_init(height + 1)) {
-    return false;
-  }
-
-  this->source_width_ = width;
-  this->source_height_ = height;
-  this->x_boundaries_.clear();
-  this->y_boundaries_.clear();
-  const uint32_t target_width = this->image_->get_buffer_width();
-  const uint32_t target_height = this->image_->get_buffer_height();
-  // Boundary n is the first target pixel source pixel n covers, rounded up. When shrinking, the source
-  // pixel whose span lands on a target pixel paints it, so an 8 to 4 scale keeps columns 0, 2, 4 and 6;
-  // the generic draw() path rounds down and keeps the odd ones instead
-  for (uint32_t x = 0; x <= static_cast<uint32_t>(width); x++) {
-    this->x_boundaries_.push_back(static_cast<uint16_t>((x * target_width + width - 1) / width));
-  }
-  for (uint32_t y = 0; y <= static_cast<uint32_t>(height); y++) {
-    this->y_boundaries_.push_back(static_cast<uint16_t>((y * target_height + height - 1) / height));
-  }
-  return true;
-}
-
 void JpegDecoder::draw_rgb565(int x, int y, int w, int h, const uint8_t *pixels) {
   if (pixels == nullptr) {
     return;
@@ -52,14 +26,14 @@ void JpegDecoder::draw_rgb565(int x, int y, int w, int h, const uint8_t *pixels)
   const uint8_t first = this->image_is_big_endian_() ? 1 : 0;
   for (int source_y = 0; source_y < h; source_y++) {
     const int absolute_y = y + source_y;
-    if (absolute_y < 0 || absolute_y >= this->source_height_) {
+    if (absolute_y < 0 || absolute_y >= this->draw_height_) {
       continue;
     }
     const uint16_t y1 = this->y_boundaries_[absolute_y];
     const uint16_t y2 = this->y_boundaries_[absolute_y + 1];
     for (int source_x = 0; source_x < w; source_x++) {
       const int absolute_x = x + source_x;
-      if (absolute_x < 0 || absolute_x >= this->source_width_) {
+      if (absolute_x < 0 || absolute_x >= this->draw_width_) {
         continue;
       }
       const uint16_t x1 = this->x_boundaries_[absolute_x];
@@ -157,17 +131,10 @@ int JpegDecoder::start_() {
   ESP_LOGD(TAG, "Image size: %d x %d, bpp: %d", this->jpeg_.getWidth(), this->jpeg_.getHeight(), this->jpeg_.getBpp());
 
   this->jpeg_.setUserPointer(this);
-  this->direct_rgb565_ = this->image_->get_type() == image::IMAGE_TYPE_RGB565 && !this->image_->has_transparency();
-  if (this->direct_rgb565_) {
-    // JPEGDEC's RGB565_BIG_ENDIAN output is not byte swapped on every build (the x86 host build
-    // returns little-endian words for it), so the byte order is applied in draw_rgb565 instead
-    this->jpeg_.setPixelType(RGB565_LITTLE_ENDIAN);
-  } else {
-    this->jpeg_.setPixelType(RGB8888);
-  }
   const int width = this->jpeg_.getWidth();
   const int height = this->jpeg_.getHeight();
-  if (!this->set_size(width, height)) {
+  // The tables for drawing are only built once the decoded size is known, below
+  if (!this->resize_image_(width, height)) {
     return DECODE_ERROR_OUT_OF_MEMORY;
   }
   // JPEGDEC can decode at 1/2, 1/4 or 1/8 size for much less work. Use the smallest size that still has at least as
@@ -181,13 +148,16 @@ int JpegDecoder::start_() {
   }
   const int decoded_width = (width + this->scale_ - 1) / this->scale_;
   const int decoded_height = (height + this->scale_ - 1) / this->scale_;
-  this->x_scale_ = static_cast<double>(buffer_width) / decoded_width;
-  this->y_scale_ = static_cast<double>(buffer_height) / decoded_height;
   if (this->scale_ != 1) {
     ESP_LOGD(TAG, "Decoding at 1/%d size, %d x %d", this->scale_, decoded_width, decoded_height);
   }
-  if (this->direct_rgb565_ && !this->prepare_rgb565_scaling_(decoded_width, decoded_height)) {
-    return DECODE_ERROR_OUT_OF_MEMORY;
+  this->prepare_draw_(decoded_width, decoded_height);
+  if (this->direct_rgb565_) {
+    // JPEGDEC's RGB565_BIG_ENDIAN output is not byte swapped on every build (the x86 host build
+    // returns little-endian words for it), so the byte order is applied in draw_rgb565 instead
+    this->jpeg_.setPixelType(RGB565_LITTLE_ENDIAN);
+  } else {
+    this->jpeg_.setPixelType(RGB8888);
   }
   return 0;
 }

esphome/components/runtime_image/jpeg_decoder.h

@@ -30,13 +30,11 @@ class JpegDecoder : public ImageDecoder {
   /// Decodes one row of MCUs (8 or 16 pixel rows), or waits part way through one for more of the source
   int HOT decode_step() override;
 
-  bool uses_direct_rgb565() const { return this->direct_rgb565_; }
   /// JPEGDEC decodes the image at 1/get_scale() of its size: 1, 2, 4 or 8
   int get_scale() const { return this->scale_; }
   void draw_rgb565(int x, int y, int w, int h, const uint8_t *pixels);
 
  protected:
-  bool prepare_rgb565_scaling_(int width, int height);
   /// Set up an opened image for decoding. Returns 0, or a DecodeError.
   int start_();
   /// The JPEGDEC option for scale_: JPEG_SCALE_HALF, _QUARTER and _EIGHTH are the divisors themselves
@@ -49,13 +47,8 @@ class JpegDecoder : public ImageDecoder {
   static void source_close(void *handle) {}
 
   JPEGDEC jpeg_{};
-  FixedVector<uint16_t> x_boundaries_{};
-  FixedVector<uint16_t> y_boundaries_{};
-  int source_width_{0};
-  int source_height_{0};
   int scale_{1};                   // JPEGDEC decodes at 1/scale_ of the image size
   DecodeSource *source_{nullptr};  // Set while a begin_source() decode is in progress
-  bool direct_rgb565_{false};
   bool source_failed_{false};
 };
 

esphome/components/runtime_image/png_decoder.cpp

@@ -6,10 +6,15 @@
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
+#include <algorithm>
+
 ESPHOME_LOG_TAG(TAG, "image_decoder.png");
 
 namespace esphome::runtime_image {
 
+// Compressed bytes handed to pngle at a time
+static constexpr size_t FEED_PIECE_SIZE = 64;
+
 /**
  * @brief Callback method that will be called by the PNGLE engine when the basic
  * data of the image is received (i.e. width and height);
@@ -93,16 +98,26 @@ int HOT PngDecoder::decode(uint8_t *buffer, size_t size) {
     ESP_LOGD(TAG, "Waiting for more data");
     return 0;
   }
-  auto fed = pngle_feed(this->pngle_, buffer, size);
-  if (fed < 0) {
-    ESP_LOGE(TAG, "Error decoding image: %s", pngle_error(this->pngle_));
-    return DECODE_ERROR_INTERNAL_DECODER_ERROR;
-  } else if (!this->size_valid_) {
-    return DECODE_ERROR_OUT_OF_MEMORY;
-  } else {
+  // A few compressed bytes can hold many rows of pixels, so feed small pieces and stop once the call has run for
+  // DECODE_TIME_LIMIT_MS; the caller passes the rest again later
+  const uint32_t start = millis();
+  size_t total = 0;
+  while (total < size) {
+    const size_t piece = std::min(FEED_PIECE_SIZE, size - total);
+    const int fed = pngle_feed(this->pngle_, buffer + total, piece);
+    if (fed < 0) {
+      ESP_LOGE(TAG, "Error decoding image: %s", pngle_error(this->pngle_));
+      return DECODE_ERROR_INTERNAL_DECODER_ERROR;
+    }
+    if (!this->size_valid_)
+      return DECODE_ERROR_OUT_OF_MEMORY;
     this->decoded_bytes_ += fed;
+    total += fed;
+    // pngle takes less than the piece when a chunk header or CRC runs past its end; that is no reason to stop
+    if (fed == 0 || millis() - start >= DECODE_TIME_LIMIT_MS)
+      break;
   }
-  return fed;
+  return total;
 }
 
 }  // namespace esphome::runtime_image

esphome/components/runtime_image/qoi_decoder.cpp

@@ -3,9 +3,11 @@
 #ifdef USE_RUNTIME_IMAGE_QOI
 
 #include "esphome/components/display/display.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
+#include <algorithm>
 #include <cinttypes>
 
 namespace esphome::runtime_image {
@@ -102,12 +104,17 @@ int HOT QoiDecoder::decode(uint8_t *buffer, size_t size) {
 
   Color color;
   const size_t total_pixels = this->width_ * this->height_;
+  // A call that has run for DECODE_TIME_LIMIT_MS stops, and the caller passes the rest again later
+  const uint32_t start = millis();
+  uint32_t steps = 0;
   while (index < size && this->paint_index_ < total_pixels) {
+    if (++steps % DECODE_TIME_CHECK_STEPS == 0 && millis() - start >= DECODE_TIME_LIMIT_MS)
+      break;
     color = this->last_pixel_;
     uint8_t byte = buffer[index];
     if (byte == QOI_OP_RGB) {
       if (size < index + QOI_RGB_CHUNK_SIZE) {
-        return index;  // Need more data for RGB chunk
+        break;  // Need more data for RGB chunk
       }
       index++;
       color.r = buffer[index++];
@@ -117,7 +124,7 @@ int HOT QoiDecoder::decode(uint8_t *buffer, size_t size) {
       this->paint_index_++;
     } else if (byte == QOI_OP_RGBA) {
       if (size < index + QOI_RGBA_CHUNK_SIZE) {
-        return index;  // Need more data for RGBA chunk
+        break;  // Need more data for RGBA chunk
       }
       index++;
       color.r = buffer[index++];
@@ -129,15 +136,18 @@ int HOT QoiDecoder::decode(uint8_t *buffer, size_t size) {
     } else if ((byte & QOI_MASK_OP) == QOI_OP_RUN) {
       // QOI run chunk
       size_t run_length = (byte & QOI_MASK_VALUE) + 1;  // run length is encoded in the lower 6 bits, plus one
-      for (size_t i = 0; i < run_length; i++) {
-        // TODO: optimize by drawing runs of pixels at once instead of one by one
-        this->draw(this->paint_index_ % this->width_, this->paint_index_ / this->width_, 1, 1, color);
-        this->paint_index_++;
+      // Draw the part of the run in each row it covers at once
+      while (run_length > 0) {
+        const size_t x = this->paint_index_ % this->width_;
+        const size_t count = std::min(run_length, this->width_ - x);
+        this->draw(x, this->paint_index_ / this->width_, count, 1, color);
+        this->paint_index_ += count;
+        run_length -= count;
       }
       index++;
     } else if ((byte & QOI_MASK_OP) == QOI_OP_LUMA) {
       if (size < index + QOI_LUMA_CHUNK_SIZE) {
-        return index;  // Need more data for LUMA chunk
+        break;  // Need more data for LUMA chunk
       }
       index++;
       uint8_t byte2 = buffer[index++];
@@ -165,8 +175,10 @@ int HOT QoiDecoder::decode(uint8_t *buffer, size_t size) {
     this->last_pixel_ = color;
     this->color_table_[qoi_color_table_index(color)] = color;
   }
-  this->decoded_bytes_ += size;
-  return size;
+  if (this->paint_index_ >= total_pixels)
+    index = size;  // All that follows the last pixel is the end marker
+  this->decoded_bytes_ += index;
+  return index;
 }
 
 }  // namespace esphome::runtime_image

esphome/components/runtime_image/runtime_image.cpp

@@ -113,7 +113,9 @@ void RuntimeImage::draw_pixel(int x, int y, const Color &color) {
     }
     case image::IMAGE_TYPE_GRAYSCALE: {
       uint32_t pos = this->get_position_(x, y);
-      auto gray = static_cast<uint8_t>(0.2125 * color.r + 0.7154 * color.g + 0.0721 * color.b);
+      // 0.2125, 0.7154 and 0.0721 in 1/256ths, summing to 256 so white stays 255. Integer maths: the S3 has no
+      // double FPU
+      auto gray = static_cast<uint8_t>((54 * color.r + 183 * color.g + 19 * color.b) >> 8);
       if (this->transparency_ == image::TRANSPARENCY_CHROMA_KEY) {
         if (gray == 1) {
           gray = 0;

esphome/components/udp/packet_interface/__init__.py

@@ -0,0 +1,40 @@
+import esphome.codegen as cg
+from esphome.components import packet_interface
+from esphome.components.packet_interface import (
+    CONF_MAX_PACKET_SIZE,
+    new_packet_interface,
+    packet_interface_schema,
+)
+from esphome.const import CONF_ID
+from esphome.types import ConfigType
+
+from .. import CONF_UDP_ID, UDP_SCHEMA, udp_ns
+
+CODEOWNERS = ["@clydebarrow"]
+
+DEPENDENCIES = ["udp"]
+
+# Size of the receive buffer of the udp component
+MAX_PACKET_SIZE = 508
+
+UdpPacketInterface = udp_ns.class_(
+    "UdpPacketInterface",
+    packet_interface.PacketInterface,
+)
+
+CONFIG_SCHEMA = packet_interface_schema(
+    UdpPacketInterface, MAX_PACKET_SIZE, MAX_PACKET_SIZE
+).extend(UDP_SCHEMA)
+
+
+async def to_code(config: ConfigType) -> None:
+    udp_var = await cg.get_variable(config[CONF_UDP_ID])
+    cg.add(udp_var.set_should_listen())
+    # The udp component sends to its addresses through its broadcast socket
+    cg.add(udp_var.set_should_broadcast())
+    # The copy buffer's size is known here, so it is a static array rather than allocated at run time
+    tx_buffer = f"{config[CONF_ID].id}__tx_buffer"
+    cg.add_global(
+        cg.RawStatement(f"static uint8_t {tx_buffer}[{config[CONF_MAX_PACKET_SIZE]}];")
+    )
+    await new_packet_interface(config, udp_var, cg.RawExpression(tx_buffer))

esphome/components/udp/packet_interface/udp_packet_interface.cpp

@@ -0,0 +1,43 @@
+#include "udp_packet_interface.h"
+#ifdef USE_NETWORK
+#include "esphome/components/network/util.h"
+#include "esphome/core/log.h"
+
+namespace esphome::udp {
+
+using packet_interface::PacketBuffer;
+using packet_interface::PacketMetaData;
+
+ESPHOME_LOG_TAG(TAG, "udp.packet_interface");
+
+void UdpPacketInterface::setup() {
+  this->parent_->add_listener([this](std::span<const uint8_t> data) { this->receive_(data); });
+}
+
+void UdpPacketInterface::receive_(std::span<const uint8_t> data) {
+  if (data.size() > this->max_packet_size_) {
+    ESP_LOGV(TAG, "%s: Packet of %zu bytes is larger than %zu, dropped", this->name_, data.size(),
+             this->max_packet_size_);
+    return;
+  }
+  this->on_receive_from_interface_(PacketBuffer(data.data(), data.size()), {});
+}
+
+bool UdpPacketInterface::send_to_interface(const PacketBuffer &data, const PacketMetaData &meta_data) {
+  size_t size = data.size();
+  if (size > this->max_packet_size_) {
+    ESP_LOGW(TAG, "%s: Packet of %zu bytes is larger than %zu", this->name_, size, this->max_packet_size_);
+    return false;
+  }
+  if (!network::is_connected())
+    return false;
+  if (data.is_contiguous()) {
+    auto span = data.as_span();
+    return this->parent_->send_packet(span.data(), span.size());
+  }
+  data.copy_to(this->tx_buffer_.data(), size);
+  return this->parent_->send_packet(this->tx_buffer_.data(), size);
+}
+
+}  // namespace esphome::udp
+#endif

esphome/components/udp/packet_interface/udp_packet_interface.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "esphome/core/defines.h"
+
+// udp_component.h declares nothing without USE_NETWORK
+#ifdef USE_NETWORK
+#include <span>
+
+#include "esphome/components/packet_interface/packet_interface.h"
+#include "../udp_component.h"
+
+namespace esphome::udp {
+
+/**
+ * A packet interface link over UDP: each packet is one datagram, sent to every address of the UDP component.
+ *
+ * Every datagram received on the listen port is passed up, from any sender, so on a shared network an addressing
+ * or encryption layer is needed to tell the peer's packets from others.
+ */
+class UdpPacketInterface : public packet_interface::PacketInterface {
+ public:
+  /// @param tx_buffer Joins packets split across buffers; its size is the largest packet, and it must outlive the link
+  UdpPacketInterface(UDPComponent *udp_component, std::span<uint8_t> tx_buffer)
+      : packet_interface::PacketInterface(tx_buffer.size()), parent_(udp_component), tx_buffer_(tx_buffer) {}
+
+  void setup() override;
+  bool send_to_interface(const packet_interface::PacketBuffer &data,
+                         const packet_interface::PacketMetaData &meta_data) override;
+
+ protected:
+  void receive_(std::span<const uint8_t> data);
+
+  UDPComponent *parent_;
+  const std::span<uint8_t> tx_buffer_;
+};
+}  // namespace esphome::udp
+#endif

esphome/components/udp/packet_transport/udp_transport.cpp

@@ -1,12 +1,9 @@
-#include "esphome/core/log.h"
 #include "esphome/core/application.h"
 #include "esphome/components/network/util.h"
 #include "udp_transport.h"
 
 namespace esphome::udp {
 
-ESPHOME_LOG_TAG(TAG, "udp_transport");
-
 bool UDPTransport::should_send() { return network::is_connected(); }
 void UDPTransport::setup() {
   PacketTransport::setup();

esphome/components/udp/udp_component.cpp

@@ -205,18 +205,25 @@ void UDPComponent::set_poll_warning_(PollStep step, const LogString *what) {
 }
 
 void UDPComponent::loop() {
-  if (this->should_listen_) {
-    std::array<uint8_t, MAX_PACKET_SIZE> buf;
-    for (;;) {
-      if (!this->listen_socket_->ready())
-        break;
-      auto len = this->listen_socket_->read(buf.data(), buf.size());
-      if (len <= 0)
-        break;
-      size_t packet_len = static_cast<size_t>(len);
-      ESP_LOGV(TAG, "Received packet of length %zu", packet_len);
-      this->packet_listeners_.call(std::span<const uint8_t>(buf.data(), packet_len));
+  if (!this->should_listen_) {
+    this->disable_loop();
+    return;
+  }
+  // One byte more than the largest packet, as a read cuts a longer datagram to fit and so cannot report it
+  std::array<uint8_t, MAX_PACKET_SIZE + 1> buf;
+  for (;;) {
+    if (!this->listen_socket_->ready())
+      break;
+    auto len = this->listen_socket_->read(buf.data(), buf.size());
+    if (len <= 0)
+      break;
+    size_t packet_len = static_cast<size_t>(len);
+    if (packet_len > MAX_PACKET_SIZE) {
+      ESP_LOGV(TAG, "Packet longer than %zu bytes dropped", MAX_PACKET_SIZE);
+      continue;
     }
+    ESP_LOGV(TAG, "Received packet of length %zu", packet_len);
+    this->packet_listeners_.call(std::span<const uint8_t>(buf.data(), packet_len));
   }
 }
 
@@ -239,9 +246,10 @@ void UDPComponent::dump_config() {
                 YESNO(this->should_broadcast_), YESNO(this->should_listen_));
 }
 
-void UDPComponent::send_packet(const uint8_t *data, size_t size) {
+bool UDPComponent::send_packet(const uint8_t *data, size_t size) {
   if (this->is_failed())
-    return;  // a send socket may be missing
+    return false;  // a send socket may be missing
+  bool sent = true;
   for (const auto &entry : this->sockaddrs_) {
 #ifdef USE_UDP_IPV6_SEND
     const bool v6 = entry.sa.sa_family == AF_INET6;
@@ -256,11 +264,23 @@ void UDPComponent::send_packet(const uint8_t *data, size_t size) {
     socket::UDPSendSocket *sock = this->broadcast_socket_.get();
     socklen_t sockaddr_size = sizeof(sockaddr_in);
 #endif
+    if (sock == nullptr) {
+      ESP_LOGW(TAG, "Broadcast socket not initialized");
+      return false;
+    }
     auto result = sock->sendto(data, size, 0, &entry.sa, sockaddr_size);
     if (result < 0) {
-      ESP_LOGW(TAG, "sendto() error %d", errno);
+      // lwIP refuses a packet with ENOMEM while the destination's ARP lookup is pending and its queue is full;
+      // the packet can be sent again later
+      if (errno == ENOMEM) {
+        ESP_LOGV(TAG, "sendto() out of memory");
+      } else {
+        ESP_LOGW(TAG, "sendto() error %d", errno);
+      }
+      sent = false;
     }
   }
+  return sent;
 }
 }  // namespace esphome::udp
 

esphome/components/udp/udp_component.h

@@ -35,8 +35,9 @@ class UDPComponent final : public Component {
   void setup() override;
   void loop() override;
   void dump_config() override;
-  void send_packet(const uint8_t *data, size_t size);
-  void send_packet(const std::vector<uint8_t> &buf) { this->send_packet(buf.data(), buf.size()); }
+  /// Returns false if the packet could not be sent to every destination.
+  bool send_packet(const uint8_t *data, size_t size);
+  bool send_packet(const std::vector<uint8_t> &buf) { return this->send_packet(buf.data(), buf.size()); }
   float get_setup_priority() const override { return setup_priority::AFTER_WIFI; };
 
  protected:
@@ -53,7 +54,7 @@ class UDPComponent final : public Component {
   bool network_poll_();
   void set_poll_warning_(PollStep step, const LogString *what);
 
-  CallbackManager<void(std::span<const uint8_t>)> packet_listeners_{};
+  LazyCallbackManager<void(std::span<const uint8_t>)> packet_listeners_{};
   std::unique_ptr<socket::UDPSendSocket> broadcast_socket_ = nullptr;
   std::unique_ptr<socket::UDPSocket> listen_socket_ = nullptr;
 #ifdef USE_UDP_IPV6_SEND

esphome/core/defines.h

@@ -273,6 +273,9 @@
 #define USE_OTA_STATE_LISTENER
 #define USE_OUTPUT
 #define USE_OUTPUT_FLOAT_POWER_SCALING
+#define USE_PACKET_INTERFACE_BASIC_SESSION
+#define USE_PACKET_INTERFACE_HDLC
+#define USE_PACKET_INTERFACE_XXTEA
 #define USE_PCA9554_PCAL
 #define USE_POWER_SUPPLY
 // Only defined by key-lookup preference backends; the slot-based platforms

esphome/espidf/sbom.py

@@ -296,7 +296,9 @@ def _external_manifests() -> list[dict[str, Any]]:
                 found[component_dir] = source
                 break
         else:
-            if not component_dir.is_relative_to(loader.CORE_COMPONENTS_PATH):
+            # Built in means anywhere in the package: the esphome domain itself
+            # is esphome/core, not under esphome/components
+            if not component_dir.is_relative_to(loader.CORE_COMPONENTS_PATH.parent):
                 _LOGGER.warning(
                     "SBOM: component '%s' in %s matches no external component "
                     "source and is listed as part of ESPHome",

esphome/mqtt.py

@@ -5,6 +5,7 @@ from datetime import datetime
 import json
 import logging
 from pathlib import Path
+import re
 import ssl
 import tempfile
 import time
@@ -23,6 +24,7 @@ from esphome.const import (
     CONF_LOG_TOPIC,
     CONF_MQTT,
     CONF_NAME,
+    CONF_NAME_ADD_MAC_SUFFIX,
     CONF_PASSWORD,
     CONF_PAYLOAD,
     CONF_PORT,
@@ -34,6 +36,7 @@ from esphome.const import (
 )
 from esphome.core import EsphomeError
 from esphome.helpers import get_int_env, get_str_env
+from esphome.mqtt_topics import per_board_suffix
 from esphome.types import ConfigType
 from esphome.util import safe_print
 
@@ -394,48 +397,101 @@ def show_logs(
     password: str | None = None,
     client_id: str | None = None,
 ) -> int:
-    if topic is not None:
-        pass  # already have topic
-    elif CONF_MQTT in config:
-        conf = config[CONF_MQTT]
-        if CONF_LOG_TOPIC in conf:
-            if config[CONF_MQTT][CONF_LOG_TOPIC] is None:
-                _LOGGER.error("MQTT log topic set to null, can't start MQTT logs")
-                return 1
-            if CONF_TOPIC not in config[CONF_MQTT][CONF_LOG_TOPIC]:
-                _LOGGER.error("MQTT log topic not available, can't start MQTT logs")
-                return 1
-            topic = config[CONF_MQTT][CONF_LOG_TOPIC][CONF_TOPIC]
-        elif CONF_TOPIC_PREFIX in config[CONF_MQTT]:
-            topic = f"{config[CONF_MQTT][CONF_TOPIC_PREFIX]}/debug"
+    # Where the device publishes its logs, also needed to match a topic given on the command line
+    config_topic: str | None = None
+    error: str | None = None
+    mqtt_conf = config.get(CONF_MQTT, {})
+    if CONF_MQTT not in config:
+        error = "MQTT isn't setup, can't start MQTT logs"
+    elif CONF_LOG_TOPIC in mqtt_conf:
+        if mqtt_conf[CONF_LOG_TOPIC] is None:
+            error = "MQTT log topic set to null, can't start MQTT logs"
+        elif CONF_TOPIC not in mqtt_conf[CONF_LOG_TOPIC]:
+            error = "MQTT log topic not available, can't start MQTT logs"
         else:
-            topic = f"{config[CONF_ESPHOME][CONF_NAME]}/debug"
+            config_topic = mqtt_conf[CONF_LOG_TOPIC][CONF_TOPIC]
+    elif CONF_TOPIC_PREFIX in mqtt_conf:
+        config_topic = f"{mqtt_conf[CONF_TOPIC_PREFIX]}/debug"
     else:
-        _LOGGER.error("MQTT isn't setup, can't start MQTT logs")
-        return 1
-    _LOGGER.info("Starting log output from %s", topic)
-
-    logs_topic = f"esphome/logs/{config[CONF_ESPHOME][CONF_NAME]}"
+        config_topic = f"{config[CONF_ESPHOME][CONF_NAME]}/debug"
+    # A topic given on the command line is followed as written
+    topic_from_cli = topic is not None
+    if not topic_from_cli:
+        if error is not None:
+            _LOGGER.error(error)
+            return 1
+        topic = config_topic
+    esphome_conf = config[CONF_ESPHOME]
+    name = esphome_conf[CONF_NAME]
+    # With the MAC suffix every board listens on esphome/logs/<name>-<mac>, which only its birth message names
+    mac_suffix = esphome_conf.get(CONF_NAME_ADD_MAC_SUFFIX, False)
     # Ask when the retained birth message reports online: a request sent while the device is down is
     # lost, and only a retained message tells a CLI that connects later that the device is already up.
     # An empty payload deletes the retained message instead, so it counts as no birth message.
-    birth = config.get(CONF_MQTT, {}).get(CONF_BIRTH_MESSAGE) or {}
+    birth = mqtt_conf.get(CONF_BIRTH_MESSAGE) or {}
     birth_payload = birth.get(CONF_PAYLOAD)
     birth_topic = birth.get(CONF_TOPIC) if birth_payload else None
-    ask_on_connect = birth_topic is None or not birth[CONF_RETAIN]
+    ask_on_connect = not mac_suffix and (birth_topic is None or not birth[CONF_RETAIN])
 
-    def request_crash_log(client: mqtt.Client) -> None:
+    def per_board(present: str | None, key: str) -> re.Pattern[str] | None:
+        # Topics the firmware builds from <name>-<mac>, which the CLI cannot know
+        if present is None or not (
+            suffix := per_board_suffix(mqtt_conf, key, name, mac_suffix)
+        ):
+            return None
+        return re.compile(rf"({re.escape(name)}-[0-9a-f]{{6}}){re.escape(suffix)}")
+
+    board_log_pattern = per_board(config_topic, CONF_LOG_TOPIC)
+    board_logs = board_log_pattern is not None
+    log_pattern = None if topic_from_cli else board_log_pattern
+    birth_pattern = per_board(birth_topic, CONF_BIRTH_MESSAGE)
+    _LOGGER.info(
+        "Starting log output from %s",
+        f"{name}-<mac>/debug of every device built from this config"
+        if log_pattern
+        else topic,
+    )
+
+    def request_crash_log(client: mqtt.Client, board: str = name) -> None:
+        logs_topic = f"esphome/logs/{board}"
         _LOGGER.debug("Requesting the crash log via topic: %s", logs_topic)
         client.publish(logs_topic, None, retain=False)
 
+    def shows_board_logs(board: str) -> bool:
+        board_topic = f"{board}/debug" if board_logs else config_topic
+        return board_topic is not None and mqtt.topic_matches_sub(topic, board_topic)
+
+    def board_to_ask(birth_msg_topic: str) -> str | None:
+        if birth_pattern is None:
+            return name if birth_msg_topic == birth_topic and not mac_suffix else None
+        if (match := birth_pattern.fullmatch(birth_msg_topic)) and (
+            # Replaying clears the stored crash, so with a --topic only ask the boards it shows
+            not topic_from_cli or shows_board_logs(match[1])
+        ):
+            return match[1]
+        return None
+
     def on_message(client: mqtt.Client, userdata: Any, msg: mqtt.MQTTMessage) -> None:
-        payload = msg.payload.decode(errors="backslashreplace")
-        if msg.topic == birth_topic and payload == birth_payload:
-            request_crash_log(client)
+        t = msg.topic
         # The birth topic may sit inside the log subscription, so print by what was asked for
-        if mqtt.topic_matches_sub(topic, msg.topic):
-            time_ = datetime.now().astimezone().time().strftime("[%H:%M:%S]")
-            safe_print(time_ + payload)
+        shown = (
+            log_pattern.fullmatch(t)
+            if log_pattern
+            else mqtt.topic_matches_sub(topic, t)
+        )
+        board = board_to_ask(t)
+        if not (shown or board):
+            return
+        payload = msg.payload.decode(errors="backslashreplace")
+        if board and payload == birth_payload:
+            request_crash_log(client, board)
+        if not shown:
+            return
+        if log_pattern:
+            # Several boards can run this config, so name the one that logged
+            payload = f"[{shown[1]}]{payload}"
+        time_ = datetime.now().astimezone().time().strftime("[%H:%M:%S]")
+        safe_print(time_ + payload)
 
     def on_connect(
         client: mqtt.Client,
@@ -447,7 +503,9 @@ def show_logs(
         if ask_on_connect:
             request_crash_log(client)
 
-    subscriptions = [topic] if birth_topic is None else [topic, birth_topic]
+    subscriptions = ["+/debug" if log_pattern else topic]
+    if birth_topic is not None:
+        subscriptions.append("+/status" if birth_pattern else birth_topic)
     return initialize(
         config, subscriptions, on_message, on_connect, username, password, client_id
     )

esphome/mqtt_topics.py

@@ -0,0 +1,43 @@
+"""MQTT topic rules shared by code generation and the MQTT log viewer."""
+
+from esphome.const import (
+    CONF_BIRTH_MESSAGE,
+    CONF_LOG_TOPIC,
+    CONF_SHUTDOWN_MESSAGE,
+    CONF_TOPIC,
+    CONF_TOPIC_PREFIX,
+    CONF_WILL_MESSAGE,
+)
+from esphome.types import ConfigType
+
+# Topic suffix of each message whose topic defaults to one under the topic prefix
+DEFAULT_TOPIC_SUFFIXES = {
+    CONF_BIRTH_MESSAGE: "/status",
+    CONF_WILL_MESSAGE: "/status",
+    CONF_SHUTDOWN_MESSAGE: "/status",
+    CONF_LOG_TOPIC: "/debug",
+}
+
+
+def prefix_gets_mac_suffix(topic_prefix: str, name: str, mac_suffix: bool) -> bool:
+    """Whether the firmware appends the MAC suffix to this topic prefix at runtime."""
+    return mac_suffix and topic_prefix == name
+
+
+def per_board_suffix(
+    mqtt_config: ConfigType, key: str, name: str, mac_suffix: bool
+) -> str | None:
+    """Topic suffix of a message the firmware sends on App.get_name() + suffix, else None.
+
+    A message missing from the config counts as the one defaulted from the topic prefix.
+    """
+    topic_prefix = mqtt_config.get(CONF_TOPIC_PREFIX, name)
+    if not prefix_gets_mac_suffix(topic_prefix, name, mac_suffix):
+        return None
+    suffix = DEFAULT_TOPIC_SUFFIXES[key]
+    if (
+        key in mqtt_config
+        and (mqtt_config[key] or {}).get(CONF_TOPIC) != f"{topic_prefix}{suffix}"
+    ):
+        return None
+    return suffix

tests/component_tests/http_request/config/max_concurrent.yaml

@@ -0,0 +1,12 @@
+esphome:
+  name: test
+
+esp32:
+  board: nodemcu-32s
+
+wifi:
+  ssid: test
+  password: testtest
+
+http_request:
+  max_concurrent_requests: 3

tests/component_tests/http_request/test_max_concurrent.py

@@ -0,0 +1,20 @@
+"""max_concurrent_requests is set only when it differs from the default of 1."""
+
+from collections.abc import Callable
+from pathlib import Path
+
+
+def test_max_concurrent_requests_default_is_not_set(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    main_cpp = generate_main(component_config_path("test_esp32_stock.yaml"))
+    assert "set_max_concurrent_requests" not in main_cpp
+
+
+def test_max_concurrent_requests_is_set(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    main_cpp = generate_main(component_config_path("max_concurrent.yaml"))
+    assert "->set_max_concurrent_requests(3);" in main_cpp

tests/component_tests/mqtt/config/mac_suffix_custom_prefix.yaml

@@ -0,0 +1,15 @@
+---
+esphome:
+  name: test-device
+  name_add_mac_suffix: true
+
+esp8266:
+  board: d1_mini_lite
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+mqtt:
+  broker: 192.168.1.2
+  topic_prefix: custom

tests/component_tests/mqtt/config/mac_suffix_default_topics.yaml

@@ -0,0 +1,14 @@
+---
+esphome:
+  name: test-device
+  name_add_mac_suffix: true
+
+esp8266:
+  board: d1_mini_lite
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+mqtt:
+  broker: 192.168.1.2

tests/component_tests/mqtt/config/mac_suffix_default_written_out.yaml

@@ -0,0 +1,18 @@
+---
+esphome:
+  name: test-device
+  name_add_mac_suffix: true
+
+esp8266:
+  board: d1_mini_lite
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+mqtt:
+  broker: 192.168.1.2
+  log_topic: test-device/debug
+  birth_message:
+    topic: test-device/status
+    payload: online

tests/component_tests/mqtt/config/mac_suffix_explicit_topics.yaml

@@ -0,0 +1,18 @@
+---
+esphome:
+  name: test-device
+  name_add_mac_suffix: true
+
+esp8266:
+  board: d1_mini_lite
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+mqtt:
+  broker: 192.168.1.2
+  log_topic: test-device/log
+  birth_message:
+    topic: test-device
+    payload: online

tests/component_tests/mqtt/config/no_mac_suffix.yaml

@@ -0,0 +1,13 @@
+---
+esphome:
+  name: test-device
+
+esp8266:
+  board: d1_mini_lite
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+mqtt:
+  broker: 192.168.1.2

tests/component_tests/mqtt/config/no_topic_prefix.yaml

@@ -0,0 +1,15 @@
+---
+esphome:
+  name: test-device
+  name_add_mac_suffix: true
+
+esp8266:
+  board: d1_mini_lite
+
+wifi:
+  ssid: MySSID
+  password: password1
+
+mqtt:
+  broker: 192.168.1.2
+  topic_prefix:

tests/component_tests/mqtt/test_mqtt_topics.py

@@ -0,0 +1,82 @@
+"""Tests for MQTT topic generation with name_add_mac_suffix."""
+
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+
+
+@pytest.mark.parametrize(
+    ("config_file", "present", "absent"),
+    [
+        pytest.param(
+            "mac_suffix_default_topics.yaml",
+            (
+                "set_topic_prefix(App.get_name())",
+                '(App.get_name() + "/status")',
+                '(App.get_name() + "/debug")',
+            ),
+            ('"test-device/status"', '"test-device/debug"'),
+            id="default topics follow the MAC suffix",
+        ),
+        pytest.param(
+            "mac_suffix_explicit_topics.yaml",
+            (
+                "set_topic_prefix(App.get_name())",
+                # will and shutdown are still defaulted from the prefix
+                '(App.get_name() + "/status")',
+                '.topic = "test-device/log",',
+                '.topic = "test-device",',
+            ),
+            ('App.get_name() + "/log"', 'App.get_name() + "/debug"'),
+            id="explicit topics stay literal",
+        ),
+        pytest.param(
+            "mac_suffix_default_written_out.yaml",
+            ('(App.get_name() + "/status")', '(App.get_name() + "/debug")'),
+            ('"test-device/status"', '"test-device/debug"'),
+            id="topics written out as the default follow the MAC suffix",
+        ),
+        pytest.param(
+            "mac_suffix_custom_prefix.yaml",
+            ('set_topic_prefix("custom")', '"custom/status"', '"custom/debug"'),
+            ("App.get_name()",),
+            id="custom prefix stays literal",
+        ),
+        pytest.param(
+            "no_mac_suffix.yaml",
+            (
+                'set_topic_prefix("test-device")',
+                '"test-device/status"',
+                '"test-device/debug"',
+            ),
+            ("App.get_name()",),
+            id="no MAC suffix",
+        ),
+        pytest.param(
+            "no_topic_prefix.yaml",
+            (
+                'set_topic_prefix("")',
+                "disable_birth_message()",
+                "disable_last_will()",
+                "disable_shutdown_message()",
+                "disable_log_message()",
+            ),
+            (),
+            id="null prefix disables default messages",
+        ),
+    ],
+)
+def test_topics(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+    config_file: str,
+    present: tuple[str, ...],
+    absent: tuple[str, ...],
+) -> None:
+    main_cpp = generate_main(component_config_path(config_file))
+
+    for text in present:
+        assert text in main_cpp
+    for text in absent:
+        assert text not in main_cpp

tests/components/as7341/__init__.py

@@ -0,0 +1,6 @@
+from tests.testing_helpers import ComponentManifestOverride
+
+
+def override_manifest(manifest: ComponentManifestOverride) -> None:
+    # The driver lives in the sensor platform, so pull in what it builds against.
+    manifest.dependencies = manifest.dependencies + ["i2c", "sensor"]

tests/components/as7341/test_as7341.cpp

@@ -0,0 +1,57 @@
+#include <gtest/gtest.h>
+
+#include <array>
+
+#include "esphome/components/as7341/as7341.h"
+
+namespace esphome::as7341::testing {
+
+static constexpr uint8_t ADDRESS = 0x39;
+static constexpr uint8_t SMUXEN = 1 << 4;
+static constexpr uint8_t AVALID = 1 << 6;
+static constexpr uint8_t NUM_ADC_CHANNELS = 6;
+
+// The chip's registers behind an address pointer that moves on after every byte.
+// SMUX commands finish at once and spectral data is always valid.
+class RegisterBus final : public i2c::I2CBus {
+ public:
+  i2c::ErrorCode write_readv(uint8_t address, const uint8_t *data, size_t size, uint8_t *out,
+                             size_t out_size) override {
+    EXPECT_EQ(address, ADDRESS);
+    if (size != 0) {
+      this->pointer_ = data[0];
+      for (size_t i = 1; i < size; i++)
+        this->registers[this->pointer_++] = data[i];
+    }
+    this->registers[AS7341_ENABLE] &= ~SMUXEN;
+    for (size_t i = 0; i < out_size; i++)
+      out[i] = this->registers[this->pointer_++];
+    return i2c::ERROR_OK;
+  }
+
+  std::array<uint8_t, 256> registers{};
+
+ protected:
+  uint8_t pointer_{0};
+};
+
+TEST(AS7341Test, ReadChannelsDecodesLowByteFirst) {
+  RegisterBus bus;
+  AS7341Component sensor;
+  sensor.set_i2c_bus(&bus);
+  sensor.set_i2c_address(ADDRESS);
+  bus.registers[AS7341_STATUS2] = AVALID;
+
+  // CHn_DATA_L holds the low byte and CHn_DATA_H, one address up, the high byte.
+  for (uint8_t channel = 0; channel < NUM_ADC_CHANNELS; channel++) {
+    bus.registers[AS7341_CH0_DATA_L + 2 * channel] = 0x34 + channel;
+    bus.registers[AS7341_CH0_DATA_H + 2 * channel] = 0x12;
+  }
+
+  std::array<uint16_t, 2 * NUM_ADC_CHANNELS> data{};
+  ASSERT_TRUE(sensor.read_channels(data.data()));
+  for (size_t i = 0; i < data.size(); i++)
+    EXPECT_EQ(data[i], 0x1234 + i % NUM_ADC_CHANNELS) << "value " << unsigned(i);
+}
+
+}  // namespace esphome::as7341::testing

tests/components/http_request/__init__.py

@@ -0,0 +1,11 @@
+import esphome.codegen as cg
+from tests.testing_helpers import ComponentManifestOverride
+
+
+def override_manifest(manifest: ComponentManifestOverride) -> None:
+    # The send action tests read the response body, which the real to_code enables for
+    # configs that capture it.
+    async def to_code_testing(config):
+        cg.add_define("USE_HTTP_REQUEST_RESPONSE")
+
+    manifest.to_code = to_code_testing

tests/components/http_request/http_request.yaml

@@ -87,6 +87,7 @@ esphome:
 http_request:
   useragent: esphome/tagreader
   timeout: 10s
+  max_concurrent_requests: 2
   verify_ssl: ${verify_ssl}
 
 output:

tests/components/http_request/test_http_request_send_action.cpp

@@ -0,0 +1,612 @@
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <cstring>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "esphome/components/http_request/http_request.h"
+#include "esphome/core/base_automation.h"
+
+namespace esphome::http_request::testing {
+
+// A response that stays pending for a number of polls, then serves its body in fixed chunks
+class FakeContainer : public HttpContainer {
+ public:
+  HttpRequestProgress poll() override {
+    this->polls++;
+    if (this->poll_delay_ms > 0)
+      delay(this->poll_delay_ms);
+    if (this->pending_polls > 0) {
+      this->pending_polls--;
+      return HttpRequestProgress::HTTP_REQUEST_PROGRESS_PENDING;
+    }
+    return this->result;
+  }
+  int read(uint8_t *buf, size_t max_len) override { return this->read_available(buf, max_len); }
+  int read_available(uint8_t *buf, size_t max_len) override {
+    if (this->stall)
+      return 0;
+    if (this->bytes_read_ >= this->fail_at)
+      return -1;
+    size_t len = std::min({max_len, this->chunk, this->body.size() - this->bytes_read_});
+    std::memcpy(buf, this->body.data() + this->bytes_read_, len);
+    this->bytes_read_ += len;
+    return static_cast<int>(len);
+  }
+  void end() override { this->ends++; }
+
+  int pending_polls{0};
+  // Time each poll() blocks, like the first connect on ESP-IDF
+  uint32_t poll_delay_ms{0};
+  HttpRequestProgress result{HttpRequestProgress::HTTP_REQUEST_PROGRESS_DONE};
+  std::string body;
+  size_t chunk{512};
+  bool stall{false};
+  // Reads fail once this many bytes have been read
+  size_t fail_at{SIZE_MAX};
+  int polls{0};
+  int ends{0};
+};
+
+class FakeHttpRequest : public HttpRequestComponent {
+ public:
+  std::shared_ptr<HttpContainer> begin(const char *url, const char *method, std::string &&body,
+                                       const std::vector<Header> &request_headers,
+                                       const std::vector<std::string> &lower_case_collect_headers,
+                                       uint32_t timeout_ms) override {
+    this->begins++;
+    if (this->refuse)
+      return nullptr;
+    auto container = std::make_shared<FakeContainer>();
+    container->status_code = 200;
+    container->pending_polls = this->pending_polls;
+    container->poll_delay_ms = this->poll_delay_ms;
+    container->body = this->response_body;
+    container->content_length = this->response_body.size();
+    this->containers.push_back(container);
+    return container;
+  }
+
+  int begins{0};
+  bool refuse{false};
+  int pending_polls{2};
+  uint32_t poll_delay_ms{0};
+  std::string response_body;
+  std::vector<std::shared_ptr<FakeContainer>> containers;
+
+ protected:
+  std::shared_ptr<HttpContainer> perform(const char *url, const char *method, const std::string &body,
+                                         const std::vector<Header> &request_headers,
+                                         const std::vector<std::string> &lower_case_collect_headers,
+                                         uint32_t timeout_ms) override {
+    return nullptr;
+  }
+};
+
+// The URL lambda must be stateless, so the stop it makes is set up through this
+struct UrlStop {
+  Automation<> *target{nullptr};
+  int calls{0};
+  int stop_at_call{0};
+};
+
+UrlStop &url_stop() {
+  static UrlStop state;
+  return state;
+}
+
+const char *url_that_can_stop() {
+  UrlStop &state = url_stop();
+  if (++state.calls == state.stop_at_call)
+    state.target->stop();
+  return "http://example.invalid/";
+}
+
+class CountAction : public Action<> {
+ public:
+  explicit CountAction(int *count) : count_(count) {}
+
+ protected:
+  void play() override { (*this->count_)++; }
+  int *count_;
+};
+
+class HttpRequestSendActionTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    this->action_.set_url([]() -> std::string { return "http://example.invalid/"; });
+    this->action_.set_method([]() -> const char * { return "GET"; });
+    this->action_.set_max_response_buffer_size(1024);
+    this->automation_.add_actions({&this->action_, &this->next_});
+    url_stop() = UrlStop{&this->automation_};
+  }
+
+  // One pass of the main loop
+  void loop_() {
+    LoopBlockingGuard guard{nullptr, nullptr, millis()};
+    this->http_.loop();
+  }
+
+  void run_until_idle_() {
+    for (int i = 0; i != 100 && this->automation_.is_running(); i++)
+      this->loop_();
+  }
+
+  void capture_response_() {
+    this->action_.set_capture_response([]() { return true; });
+    this->with_body_.add_action(&this->store_body_);
+  }
+
+  FakeHttpRequest http_;
+  HttpRequestSendAction<> action_{&this->http_};
+  int next_count_{0};
+  CountAction next_{&this->next_count_};
+  Trigger<> trigger_;
+  Automation<> automation_{&this->trigger_};
+
+  int responses_{0};
+  int errors_{0};
+  std::string body_;
+  Automation<std::shared_ptr<HttpContainer>> on_response_{this->action_.get_success_trigger()};
+  LambdaAction<std::shared_ptr<HttpContainer>> count_response_{
+      [this](const std::shared_ptr<HttpContainer> &) { this->responses_++; }};
+  Automation<> on_error_{this->action_.get_error_trigger()};
+  CountAction count_error_{&this->errors_};
+  Automation<std::shared_ptr<HttpContainer>, std::string &> with_body_{
+      this->action_.get_success_trigger_with_response()};
+  LambdaAction<std::shared_ptr<HttpContainer>, std::string &> store_body_{
+      [this](const std::shared_ptr<HttpContainer> &, std::string &body) {
+        this->responses_++;
+        this->body_ = body;
+      }};
+
+ public:
+  HttpRequestSendActionTest() {
+    this->on_response_.add_action(&this->count_response_);
+    this->on_error_.add_action(&this->count_error_);
+  }
+};
+
+TEST_F(HttpRequestSendActionTest, ChainWaitsForTheResponse) {
+  this->trigger_.trigger();
+  EXPECT_EQ(this->http_.begins, 1);
+  EXPECT_TRUE(this->automation_.is_running());
+  EXPECT_EQ(this->next_count_, 0);
+
+  this->loop_();
+  this->loop_();
+  EXPECT_EQ(this->next_count_, 0);
+  EXPECT_EQ(this->responses_, 0);
+
+  this->loop_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->errors_, 0);
+  EXPECT_EQ(this->next_count_, 1);
+  EXPECT_EQ(this->http_.containers[0]->ends, 1);
+  EXPECT_FALSE(this->automation_.is_running());
+}
+
+TEST_F(HttpRequestSendActionTest, RequestThatCannotStartFiresOnErrorAtOnce) {
+  this->http_.refuse = true;
+  this->trigger_.trigger();
+  EXPECT_EQ(this->errors_, 1);
+  EXPECT_EQ(this->responses_, 0);
+  EXPECT_EQ(this->next_count_, 1);
+  EXPECT_FALSE(this->automation_.is_running());
+}
+
+TEST_F(HttpRequestSendActionTest, FailedRequestFiresOnError) {
+  this->trigger_.trigger();
+  this->http_.containers[0]->result = HttpRequestProgress::HTTP_REQUEST_PROGRESS_FAILED;
+  this->run_until_idle_();
+  EXPECT_EQ(this->errors_, 1);
+  EXPECT_EQ(this->responses_, 0);
+  EXPECT_EQ(this->next_count_, 1);
+  EXPECT_EQ(this->http_.containers[0]->ends, 1);
+}
+
+TEST_F(HttpRequestSendActionTest, SecondTriggerWaitsForTheFirstRequest) {
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  EXPECT_EQ(this->http_.begins, 1);
+
+  this->loop_();
+  this->loop_();
+  EXPECT_EQ(this->http_.begins, 1);
+
+  // The first finishes, and the second starts on the next pass
+  this->loop_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->http_.begins, 1);
+  this->loop_();
+  EXPECT_EQ(this->http_.begins, 2);
+
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 2);
+  EXPECT_EQ(this->next_count_, 2);
+}
+
+TEST_F(HttpRequestSendActionTest, TriggersBeyondTheQueueAreDropped) {
+  for (int i = 0; i != 7; i++)
+    this->trigger_.trigger();
+  // One running, four waiting, two dropped with on_error
+  EXPECT_EQ(this->http_.begins, 1);
+  EXPECT_EQ(this->errors_, 2);
+  EXPECT_EQ(this->next_count_, 2);
+
+  this->run_until_idle_();
+  EXPECT_EQ(this->http_.begins, 5);
+  EXPECT_EQ(this->responses_, 5);
+  EXPECT_EQ(this->next_count_, 7);
+}
+
+TEST_F(HttpRequestSendActionTest, WaitingRequestThatCannotStartFiresOnError) {
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  this->http_.refuse = true;
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->errors_, 1);
+  EXPECT_EQ(this->next_count_, 2);
+}
+
+TEST_F(HttpRequestSendActionTest, StopEndsRequestsWithoutTriggers) {
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  this->automation_.stop();
+  EXPECT_FALSE(this->automation_.is_running());
+  EXPECT_EQ(this->http_.containers[0]->ends, 1);
+
+  this->loop_();
+  this->loop_();
+  this->loop_();
+  EXPECT_EQ(this->http_.begins, 1);
+  EXPECT_EQ(this->responses_, 0);
+  EXPECT_EQ(this->errors_, 0);
+  EXPECT_EQ(this->next_count_, 0);
+
+  // The action is usable again after a stop
+  this->trigger_.trigger();
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->next_count_, 1);
+}
+
+TEST_F(HttpRequestSendActionTest, StopFromOnResponseDropsTheRest) {
+  LambdaAction<std::shared_ptr<HttpContainer>> stop{
+      [this](const std::shared_ptr<HttpContainer> &) { this->automation_.stop(); }};
+  this->on_response_.add_action(&stop);
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->http_.begins, 1);
+  EXPECT_EQ(this->next_count_, 0);
+  EXPECT_FALSE(this->automation_.is_running());
+}
+
+// A script in mode restart that executes itself from on_response
+TEST_F(HttpRequestSendActionTest, RestartFromOnResponseContinuesOnlyTheNewRun) {
+  int restarts = 0;
+  LambdaAction<std::shared_ptr<HttpContainer>> restart{[this, &restarts](const std::shared_ptr<HttpContainer> &) {
+    if (restarts++ == 0) {
+      this->automation_.stop();
+      this->trigger_.trigger();
+    }
+  }};
+  this->on_response_.add_action(&restart);
+  this->trigger_.trigger();
+  this->loop_();
+  this->loop_();
+  this->loop_();
+  EXPECT_EQ(this->http_.begins, 2);
+  EXPECT_EQ(this->http_.containers[0]->ends, 1);
+  EXPECT_EQ(this->next_count_, 0);
+  EXPECT_TRUE(this->automation_.is_running());
+
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 2);
+  EXPECT_EQ(this->next_count_, 1);
+  EXPECT_FALSE(this->automation_.is_running());
+}
+
+TEST_F(HttpRequestSendActionTest, RestartFromOnErrorContinuesOnlyTheNewRun) {
+  LambdaAction<> restart{[this]() {
+    if (this->http_.refuse) {
+      this->http_.refuse = false;
+      this->automation_.stop();
+      this->trigger_.trigger();
+    }
+  }};
+  this->on_error_.add_action(&restart);
+  this->http_.refuse = true;
+  this->trigger_.trigger();
+  EXPECT_EQ(this->errors_, 1);
+  EXPECT_EQ(this->http_.begins, 2);
+  EXPECT_EQ(this->next_count_, 0);
+  EXPECT_TRUE(this->automation_.is_running());
+
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->next_count_, 1);
+  EXPECT_FALSE(this->automation_.is_running());
+}
+
+TEST_F(HttpRequestSendActionTest, TriggerFromOnResponseStartsAtOnce) {
+  int retriggers = 0;
+  LambdaAction<std::shared_ptr<HttpContainer>> again{[this, &retriggers](const std::shared_ptr<HttpContainer> &) {
+    if (retriggers++ == 0)
+      this->trigger_.trigger();
+  }};
+  this->on_response_.add_action(&again);
+  this->trigger_.trigger();
+  this->loop_();
+  this->loop_();
+  this->loop_();
+  EXPECT_EQ(this->http_.begins, 2);
+
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 2);
+  EXPECT_EQ(this->next_count_, 2);
+}
+
+TEST_F(HttpRequestSendActionTest, CapturedBodyIsReadAcrossPasses) {
+  this->capture_response_();
+  this->http_.pending_polls = 0;
+  this->http_.response_body = std::string(900, 'a');
+  this->trigger_.trigger();
+  this->http_.containers[0]->chunk = 100;
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->body_, std::string(900, 'a'));
+  EXPECT_EQ(this->next_count_, 1);
+}
+
+TEST_F(HttpRequestSendActionTest, CapturedBodyStopsAtTheBufferSize) {
+  this->capture_response_();
+  this->action_.set_max_response_buffer_size(300);
+  this->http_.response_body = std::string(1000, 'b');
+  this->trigger_.trigger();
+  this->run_until_idle_();
+  EXPECT_EQ(this->body_, std::string(300, 'b'));
+}
+
+TEST_F(HttpRequestSendActionTest, StalledBodyEndsAtTheTimeout) {
+  this->capture_response_();
+  this->action_.set_timeout([]() -> uint32_t { return 20; });
+  this->http_.response_body = std::string(1000, 'c');
+  this->trigger_.trigger();
+  this->http_.containers[0]->stall = true;
+  this->loop_();
+  this->loop_();
+  this->loop_();
+  EXPECT_TRUE(this->automation_.is_running());
+
+  delay(30);
+  this->loop_();
+  EXPECT_FALSE(this->automation_.is_running());
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_TRUE(this->body_.empty());
+}
+
+// A url lambda that stops the action while the request is being started
+TEST_F(HttpRequestSendActionTest, StopFromLambdaWhileStartingEndsTheRequest) {
+  this->action_.set_url([]() -> std::string { return url_that_can_stop(); });
+  url_stop().stop_at_call = 1;
+  this->trigger_.trigger();
+  EXPECT_FALSE(this->automation_.is_running());
+  ASSERT_EQ(this->http_.begins, 1);
+  EXPECT_EQ(this->http_.containers[0]->ends, 1);
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 0);
+  EXPECT_EQ(this->errors_, 0);
+  EXPECT_EQ(this->next_count_, 0);
+
+  this->trigger_.trigger();
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->next_count_, 1);
+}
+
+TEST_F(HttpRequestSendActionTest, StopFromLambdaOfAWaitingRequestEndsIt) {
+  this->action_.set_url([]() -> std::string { return url_that_can_stop(); });
+  url_stop().stop_at_call = 2;
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  this->run_until_idle_();
+  EXPECT_FALSE(this->automation_.is_running());
+  ASSERT_EQ(this->http_.begins, 2);
+  EXPECT_EQ(this->http_.containers[1]->polls, 0);
+  EXPECT_EQ(this->http_.containers[1]->ends, 1);
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->next_count_, 1);
+
+  // The slot counts survived the stop, so a new trigger starts at once
+  this->trigger_.trigger();
+  EXPECT_EQ(this->http_.begins, 3);
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 2);
+  EXPECT_EQ(this->next_count_, 2);
+}
+
+TEST_F(HttpRequestSendActionTest, ReadErrorKeepsTheBodyReadSoFar) {
+  this->capture_response_();
+  this->http_.response_body = std::string(800, 'd');
+  this->trigger_.trigger();
+  this->http_.containers[0]->chunk = 100;
+  this->http_.containers[0]->fail_at = 300;
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->errors_, 0);
+  EXPECT_EQ(this->body_, std::string(300, 'd'));
+  EXPECT_EQ(this->next_count_, 1);
+}
+
+TEST_F(HttpRequestSendActionTest, BufferThatCannotBeAllocatedGivesAnEmptyBody) {
+  this->capture_response_();
+  this->action_.set_max_response_buffer_size(SIZE_MAX);
+  this->http_.response_body = "unread";
+  this->body_ = "not set";
+  this->trigger_.trigger();
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_TRUE(this->body_.empty());
+  EXPECT_EQ(this->next_count_, 1);
+}
+
+// A forced reboot calls only on_shutdown(), which finishes the requests in progress
+TEST_F(HttpRequestSendActionTest, ShutdownFinishesTheRequestInProgress) {
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  EXPECT_EQ(this->responses_, 0);
+  this->http_.on_shutdown();
+  EXPECT_EQ(this->responses_, 2);
+  EXPECT_EQ(this->next_count_, 2);
+  EXPECT_FALSE(this->automation_.is_running());
+}
+
+// An on_shutdown automation that runs after the component's on_shutdown()
+TEST_F(HttpRequestSendActionTest, RequestAfterShutdownFinishesAtOnce) {
+  this->http_.on_shutdown();
+  this->trigger_.trigger();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->next_count_, 1);
+  EXPECT_FALSE(this->automation_.is_running());
+}
+
+TEST_F(HttpRequestSendActionTest, BodyTimeoutStartsAfterABlockingPoll) {
+  this->capture_response_();
+  this->action_.set_timeout([]() -> uint32_t { return 20; });
+  this->http_.pending_polls = 0;
+  this->http_.poll_delay_ms = 30;
+  this->http_.response_body = std::string(100, 'e');
+  this->trigger_.trigger();
+  this->http_.containers[0]->stall = true;
+  this->loop_();
+  EXPECT_TRUE(this->automation_.is_running());
+
+  this->http_.containers[0]->stall = false;
+  this->run_until_idle_();
+  EXPECT_EQ(this->body_, std::string(100, 'e'));
+}
+
+TEST_F(HttpRequestSendActionTest, DurationCoversTheWholeBody) {
+  this->capture_response_();
+  this->http_.pending_polls = 0;
+  this->http_.response_body = std::string(100, 'f');
+  this->trigger_.trigger();
+  auto container = this->http_.containers[0];
+  container->duration_ms = 1;
+  container->stall = true;
+  this->loop_();
+  delay(30);
+  container->stall = false;
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_GE(container->duration_ms, 30u);
+}
+
+// The limit is per http_request component, so that one client is held at a time
+TEST_F(HttpRequestSendActionTest, TwoActionsTakeTurns) {
+  HttpRequestSendAction<> other{&this->http_};
+  other.set_url([]() -> std::string { return "http://example.invalid/other"; });
+  other.set_method([]() -> const char * { return "GET"; });
+  int other_next = 0;
+  CountAction count_other{&other_next};
+  Trigger<> other_trigger;
+  Automation<> other_automation{&other_trigger};
+  other_automation.add_actions({&other, &count_other});
+
+  this->trigger_.trigger();
+  other_trigger.trigger();
+  EXPECT_EQ(this->http_.begins, 1);
+  this->loop_();
+  this->loop_();
+  this->loop_();
+  EXPECT_EQ(this->next_count_, 1);
+  EXPECT_EQ(other_next, 0);
+  EXPECT_EQ(this->http_.begins, 1);
+
+  for (int i = 0; i != 10 && other_automation.is_running(); i++)
+    this->loop_();
+  EXPECT_EQ(this->http_.begins, 2);
+  EXPECT_EQ(other_next, 1);
+}
+
+// Stopping one action leaves the requests of another alone
+TEST_F(HttpRequestSendActionTest, StopEndsOnlyThatActionsRequests) {
+  HttpRequestSendAction<> other{&this->http_};
+  other.set_url([]() -> std::string { return "http://example.invalid/other"; });
+  other.set_method([]() -> const char * { return "GET"; });
+  int other_next = 0;
+  CountAction count_other{&other_next};
+  Trigger<> other_trigger;
+  Automation<> other_automation{&other_trigger};
+  other_automation.add_actions({&other, &count_other});
+
+  other_trigger.trigger();
+  this->trigger_.trigger();
+  this->automation_.stop();
+  for (int i = 0; i != 10 && other_automation.is_running(); i++)
+    this->loop_();
+  EXPECT_EQ(other_next, 1);
+  EXPECT_EQ(this->next_count_, 0);
+  EXPECT_EQ(this->http_.begins, 1);
+}
+
+// A safe shutdown drops the requests already made, so they do not hold up the reboot,
+// and still sends the ones that on_shutdown automations make
+TEST_F(HttpRequestSendActionTest, SafeShutdownSendsOnlyTheShutdownRequests) {
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  this->http_.on_safe_shutdown();
+  EXPECT_EQ(this->http_.containers[0]->ends, 1);
+  EXPECT_EQ(this->responses_, 0);
+  EXPECT_EQ(this->errors_, 0);
+  // Stopped like script.stop, so a mode single script could run it again from on_shutdown
+  EXPECT_FALSE(this->automation_.is_running());
+
+  this->trigger_.trigger();
+  EXPECT_EQ(this->responses_, 1);
+  this->http_.on_shutdown();
+  EXPECT_EQ(this->http_.begins, 2);
+  EXPECT_EQ(this->responses_, 1);
+  EXPECT_EQ(this->next_count_, 1);
+}
+
+TEST_F(HttpRequestSendActionTest, MaxConcurrentRequestsRunTogether) {
+  this->http_.set_max_concurrent_requests(2);
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  this->trigger_.trigger();
+  EXPECT_EQ(this->http_.begins, 2);
+
+  // Both finish on the third pass; the third request takes a free slot on the next
+  this->loop_();
+  this->loop_();
+  this->loop_();
+  EXPECT_EQ(this->responses_, 2);
+  EXPECT_EQ(this->http_.begins, 2);
+  this->loop_();
+  EXPECT_EQ(this->http_.begins, 3);
+
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 3);
+  EXPECT_EQ(this->next_count_, 3);
+}
+
+TEST_F(HttpRequestSendActionTest, MaxConcurrentRequestsKeepsTheQueueLimit) {
+  this->http_.set_max_concurrent_requests(2);
+  for (int i = 0; i != 8; i++)
+    this->trigger_.trigger();
+  // Two running, four waiting, two dropped
+  EXPECT_EQ(this->http_.begins, 2);
+  EXPECT_EQ(this->errors_, 2);
+  this->run_until_idle_();
+  EXPECT_EQ(this->responses_, 6);
+  EXPECT_EQ(this->next_count_, 8);
+}
+
+}  // namespace esphome::http_request::testing

tests/components/online_image/test_download_end.cpp

@@ -12,8 +12,10 @@
 
 #include "esphome/components/http_request/http_request.h"
 #include "esphome/components/online_image/online_image.h"
+#include "esphome/components/runtime_image/png_decoder.h"
 #include "esphome/core/application.h"
 #include "esphome/core/hal.h"
+#include "pngle.h"
 
 namespace esphome::online_image::testing {
 
@@ -135,6 +137,153 @@ static constexpr std::array<uint8_t, 69> PNG_1X1{
     0x0C, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9C, 0x63, 0xF8, 0xCF, 0xC0, 0x00, 0x00, 0x03, 0x01, 0x01, 0x00, 0xC9,
     0xFE, 0x92, 0xEF, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82};
 
+// 800x600 RGB PNG of a single color, 2312 bytes: the decoder needs several calls to draw it.
+// The same bytes are in tests/components/runtime_image/test_png_time_limit.cpp.
+static const uint8_t PNG_SOLID[] = {
+    0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x03,
+    0x20, 0x00, 0x00, 0x02, 0x58, 0x08, 0x02, 0x00, 0x00, 0x00, 0x15, 0x14, 0x15, 0x27, 0x00, 0x00, 0x08, 0xCF, 0x49,
+    0x44, 0x41, 0x54, 0x78, 0xDA, 0xED, 0xD6, 0x31, 0x11, 0x00, 0x30, 0x08, 0x00, 0xB1, 0x52, 0x21, 0xE8, 0x44, 0x22,
+    0xB2, 0x30, 0xC1, 0x31, 0x25, 0x12, 0x7E, 0xFA, 0xC8, 0xEA, 0x07, 0x00, 0xC0, 0x9E, 0x2F, 0x01, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58,
+    0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80,
+    0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x83, 0x25, 0x01, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80,
+    0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00,
+    0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80,
+    0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x25, 0x01, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0xDC, 0x19, 0x79, 0xA5, 0x06, 0x0E, 0x33, 0xD4, 0xAF,
+    0xF2, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82,
+};
+
+// Draws that take a millisecond every fourth row, so decoding PNG_SOLID always outlasts the time limit of one call
+class SlowDraws : public runtime_image::PngDecoder, public runtime_image::RuntimeImage {
+ public:
+  static void install(runtime_image::RuntimeImage &image) {
+    auto *decoder = static_cast<runtime_image::PngDecoder *>((image.*&SlowDraws::decoder_).get());
+    pngle_set_draw_callback(decoder->*&SlowDraws::pngle_, draw);
+  }
+
+ private:
+  static void draw(pngle_t *pngle, uint32_t x, uint32_t y, uint32_t w, uint32_t h, const uint8_t rgba[4]) {
+    if (x == 0 && y % 4 == 0) {
+      const uint32_t until = millis() + 2;
+      while (millis() < until) {
+      }
+    }
+    static_cast<runtime_image::PngDecoder *>(pngle_get_user_data(pngle))
+        ->draw(x, y, w, h, Color(rgba[0], rgba[1], rgba[2], rgba[3]));
+  }
+};
+
 // 8x8 progressive JPEG, 521 bytes
 static const uint8_t JPEG_PROGRESSIVE[] = {
     0xFF, 0xD8, 0xFF, 0xE0, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46, 0x00, 0x01, 0x01, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00,
@@ -458,6 +607,30 @@ TEST_F(OnlineImageDownloadEnd, JpegBufferAllocationFailureReportsError) {
   EXPECT_EQ(this->finished_, 0);
 }
 
+// The whole PNG arrives in one read, but the decoder stops after a short time per call: the rest is decoded on
+// later passes, not reported as data the decoder could not use
+TEST_F(OnlineImageDownloadEnd, PngDecodedOverSeveralPassesAfterTheDownloadEnds) {
+  for (bool chunked : {false, true}) {
+    this->finished_ = 0;
+    this->errors_ = 0;
+    auto image = this->make_image_(runtime_image::PNG, 4096);
+    auto container = std::make_shared<FakeContainer>(std::vector<uint8_t>(PNG_SOLID, PNG_SOLID + sizeof(PNG_SOLID)),
+                                                     sizeof(PNG_SOLID), chunked);
+    this->start_(*image, container);
+    SlowDraws::install(*image);
+
+    int passes = 0;
+    for (; passes < 1000 && this->finished_ + this->errors_ == 0; passes++)
+      image->loop();
+
+    EXPECT_EQ(this->finished_, 1) << (chunked ? "chunked" : "with Content-Length");
+    EXPECT_EQ(this->errors_, 0);
+    EXPECT_GT(passes, 2);
+    EXPECT_EQ(image->get_width(), 800);
+    EXPECT_EQ(image->get_pixel(400, 300).b, 200);
+  }
+}
+
 // The JPEG decoded with all of it in memory at once, to compare the downloaded images with
 static std::vector<uint8_t> reference_jpeg_pixels() {
   runtime_image::RuntimeImage ref(runtime_image::JPEG, image::IMAGE_TYPE_RGB, image::TRANSPARENCY_OPAQUE);

tests/components/packet_interface/__init__.py

@@ -0,0 +1,11 @@
+import esphome.codegen as cg
+from tests.testing_helpers import ComponentManifestOverride
+
+
+def override_manifest(manifest: ComponentManifestOverride) -> None:
+    async def to_code_testing(config: object) -> None:
+        cg.add_define("USE_PACKET_INTERFACE_BASIC_SESSION")
+        cg.add_define("USE_PACKET_INTERFACE_HDLC")
+        cg.add_define("USE_PACKET_INTERFACE_XXTEA")
+
+    manifest.to_code = to_code_testing

tests/components/packet_interface/basic_session.cpp

@@ -0,0 +1,252 @@
+#include <gtest/gtest.h>
+#include <cstdint>
+#include <memory>
+#include <vector>
+#include "esphome/components/packet_interface/basic_session.h"
+#include "esphome/core/application.h"
+
+namespace esphome::packet_interface::session_testing {
+
+// Copies a packet into a vector, for comparing in tests
+static std::vector<uint8_t> to_vector(const esphome::packet_interface::PacketBuffer &data) {
+  std::vector<uint8_t> result(data.size());
+  data.copy_to(result.data(), result.size());
+  return result;
+}
+
+using Packet = std::vector<uint8_t>;
+
+// A link layer that records what is sent, so a test can deliver it to the peer
+class MockLink : public PacketInterface {
+ public:
+  explicit MockLink(size_t max_packet_size = 64) : PacketInterface(max_packet_size) {}
+  bool send_to_interface(const PacketBuffer &data, const PacketMetaData &) override {
+    if (!this->accept)
+      return false;
+    this->sent.push_back(to_vector(data));
+    return true;
+  }
+  void inject(const Packet &packet) { this->on_receive_from_interface_(PacketBuffer(packet), {}); }
+  // Act as a reliability layer that resets and discards data
+  void set_reliable() { this->capabilities_ = CAPABILITY_RELIABILITY; }
+  void report_data_lost() { this->session_callback_.call(false); }
+
+  std::vector<Packet> sent;
+  bool accept{true};
+};
+
+class TestSession : public BasicSession {
+ public:
+  using BasicSession::BasicSession;
+  using BasicSession::on_interval_;
+  unsigned get_not_understood_count() const { return this->not_understood_count_; }
+};
+
+struct Peer {
+  Peer() {
+    this->session = std::make_unique<TestSession>(&this->link);
+    this->session->set_keep_alive(1000);
+    this->session->set_session_timeout(3000);
+    this->session->add_packet_interface_listener(
+        [this](const PacketBuffer &data, const PacketMetaData &) { this->received.push_back(to_vector(data)); });
+    this->session->add_on_session_state_callback([this](bool connected) { this->states.push_back(connected); });
+    this->session->setup();
+  }
+  bool send(const Packet &data) { return this->session->send_to_interface(PacketBuffer(data), {}); }
+
+  MockLink link;
+  std::unique_ptr<TestSession> session;
+  std::vector<Packet> received;
+  std::vector<bool> states;
+};
+
+static bool is_keep_alive(const Packet &packet) { return !packet.empty() && packet[0] == 0x01; }
+
+// Move packets between the peers until nothing more is sent
+static void pump(Peer &a, Peer &b) {
+  for (int i = 0; i != 20; i++) {
+    if (a.link.sent.empty() && b.link.sent.empty())
+      return;
+    auto from_a = std::move(a.link.sent);
+    auto from_b = std::move(b.link.sent);
+    a.link.sent.clear();
+    b.link.sent.clear();
+    for (auto &packet : from_a)
+      b.link.inject(packet);
+    for (auto &packet : from_b)
+      a.link.inject(packet);
+  }
+  FAIL() << "Peers did not go quiet";
+}
+
+// Each test replaces App with a fresh one; the keep-alive interval needs its scheduler
+class BasicSessionTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    App.~Application();
+    new (&App) Application();
+    static char name[] = "session-tests";
+    static char friendly_name[] = "";
+    App.pre_setup(name, sizeof(name) - 1, friendly_name, 0);
+  }
+  void TearDown() override {
+    App.~Application();
+    new (&App) Application();  // later tests and the test listener use App
+  }
+
+  static void set_time(uint32_t now) { LoopBlockingGuard guard{nullptr, nullptr, now}; }
+};
+
+TEST_F(BasicSessionTest, MaxPacketSizeAllowsForHeader) {
+  Peer a;
+  EXPECT_EQ(a.session->get_max_packet_size(), 64 - BasicSession::HEADER_SIZE);
+  EXPECT_EQ(a.link.top(), a.session.get());
+  EXPECT_EQ(a.session->get_capabilities(), CAPABILITY_SESSION);
+}
+
+TEST_F(BasicSessionTest, KeepAliveSentAtSetup) {
+  Peer a;
+  ASSERT_EQ(a.link.sent.size(), 1);
+  EXPECT_TRUE(is_keep_alive(a.link.sent[0]));
+  EXPECT_EQ(a.link.sent[0].size(), 5);
+  EXPECT_FALSE(a.session->is_connected());
+}
+
+TEST_F(BasicSessionTest, BothConnectWithoutRepeatedAnswers) {
+  Peer a, b;
+  pump(a, b);
+  EXPECT_TRUE(a.session->is_connected());
+  EXPECT_TRUE(b.session->is_connected());
+  EXPECT_EQ(a.states, std::vector<bool>{true});
+  EXPECT_EQ(b.states, std::vector<bool>{true});
+}
+
+TEST_F(BasicSessionTest, OneSideStartsLater) {
+  Peer a;
+  a.link.sent.clear();  // a's first keep-alive is lost
+  Peer b;
+  pump(a, b);
+  EXPECT_TRUE(a.session->is_connected());
+  EXPECT_TRUE(b.session->is_connected());
+}
+
+TEST_F(BasicSessionTest, DataPassesThroughWithHeader) {
+  Peer a, b;
+  pump(a, b);
+  ASSERT_TRUE(a.send({0x10, 0x11}));
+  ASSERT_EQ(a.link.sent.size(), 1);
+  EXPECT_EQ(a.link.sent[0], (Packet{0x00, 0x10, 0x11}));
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Packet>{{0x10, 0x11}}));
+  EXPECT_TRUE(a.received.empty());
+}
+
+TEST_F(BasicSessionTest, NotUnderstoodPacketsCountedUntilOneIsUnderstood) {
+  Peer a;
+  for (int i = 0; i != 20; i++)
+    a.link.inject({0x7F, 0x00});
+  // The count stops where the mismatch is logged, so it is logged once
+  EXPECT_EQ(a.session->get_not_understood_count(), 10);
+  a.link.inject({0x00, 0x55});
+  EXPECT_EQ(a.session->get_not_understood_count(), 0);
+}
+
+TEST_F(BasicSessionTest, DataMarksPeerConnected) {
+  Peer a;
+  a.link.inject({0x00, 0x42});
+  EXPECT_TRUE(a.session->is_connected());
+  EXPECT_EQ(a.received, (std::vector<Packet>{{0x42}}));
+}
+
+TEST_F(BasicSessionTest, DataBeforeFirstKeepAliveIsNotARestart) {
+  Peer a, b;
+  a.link.sent.clear();
+  b.link.sent.clear();  // b's first keep-alive is lost
+  b.send({0x42});
+  pump(a, b);
+  b.session->on_interval_();
+  pump(a, b);
+  EXPECT_EQ(a.states, std::vector<bool>{true});
+}
+
+TEST_F(BasicSessionTest, SendFailureIsReturned) {
+  Peer a;
+  a.link.accept = false;
+  EXPECT_FALSE(a.send({0x01}));
+}
+
+TEST_F(BasicSessionTest, IntervalSendsKeepAlive) {
+  Peer a;
+  a.link.sent.clear();
+  a.session->on_interval_();
+  ASSERT_EQ(a.link.sent.size(), 1);
+  EXPECT_TRUE(is_keep_alive(a.link.sent[0]));
+}
+
+TEST_F(BasicSessionTest, PeerLostAfterTimeout) {
+  Peer a, b;
+  set_time(1000);
+  pump(a, b);
+  set_time(4000);
+  a.session->on_interval_();
+  EXPECT_TRUE(a.session->is_connected());
+  set_time(4001);
+  a.session->on_interval_();
+  EXPECT_FALSE(a.session->is_connected());
+  EXPECT_EQ(a.states, (std::vector<bool>{true, false}));
+  // Heard again
+  b.session->on_interval_();
+  pump(a, b);
+  EXPECT_TRUE(a.session->is_connected());
+  EXPECT_EQ(a.states, (std::vector<bool>{true, false, true}));
+}
+
+TEST_F(BasicSessionTest, PeerRestartIsReported) {
+  Peer a;
+  auto b = std::make_unique<Peer>();
+  pump(a, *b);
+  b = std::make_unique<Peer>();
+  pump(a, *b);
+  EXPECT_TRUE(a.session->is_connected());
+  EXPECT_EQ(a.states, (std::vector<bool>{true, false, true}));
+  EXPECT_EQ(b->states, std::vector<bool>{true});
+}
+
+TEST_F(BasicSessionTest, MalformedPacketsDropped) {
+  Peer a;
+  a.link.inject({});
+  a.link.inject({0x02, 0x00});
+  a.link.inject({0x01, 0x00, 0x00});
+  EXPECT_FALSE(a.session->is_connected());
+  EXPECT_TRUE(a.received.empty());
+}
+
+TEST_F(BasicSessionTest, DataLostBelowReportedAsSessionLost) {
+  MockLink link;
+  link.set_reliable();
+  TestSession session(&link);
+  std::vector<bool> states;
+  session.add_on_session_state_callback([&states](bool connected) { states.push_back(connected); });
+  session.setup();
+  // Not yet connected, so nothing to report
+  link.report_data_lost();
+  EXPECT_TRUE(states.empty());
+  link.inject({0x00, 0x55});
+  link.report_data_lost();
+  EXPECT_FALSE(session.is_connected());
+  // Connected again when the peer is next heard
+  link.inject({0x00, 0x56});
+  EXPECT_EQ(states, (std::vector<bool>{true, false, true}));
+}
+
+TEST_F(BasicSessionTest, LinkTooSmallForKeepAliveFailsSetup) {
+  MockLink link(4);
+  TestSession session(&link);
+  session.setup();
+  EXPECT_TRUE(session.is_failed());
+  EXPECT_TRUE(link.sent.empty());
+  Packet packet{1};
+  EXPECT_FALSE(session.send_to_interface(PacketBuffer(packet), {}));
+}
+
+}  // namespace esphome::packet_interface::session_testing

tests/components/packet_interface/common.yaml

@@ -1,7 +1,33 @@
+wifi:
+  ssid: MySSID
+  password: password1
+
+udp:
+  - id: packet_interface_udp
+
 packet_interface:
   - platform: uart
     id: packet_interface_uart
     max_packet_size: 256
+    reliability:
+      timeout: 300ms
+      ack_delay: 50ms
+      max_queue_length: 3
+      max_retries: 4
+    encryption:
+      key: Johnny Cash
+      rolling_code_enable: true
+    session:
+      keep_alive: 5s
+      timeout: 12s
+      binary_sensor:
+        name: UART session
+  - platform: udp
+    id: packet_interface_network
+    udp_id: packet_interface_udp
+    encryption: Johnny Cash
+    reliability:
+    session:
 
 sensor:
   - platform: template
@@ -13,3 +39,7 @@ packet_transport:
     packet_interface: packet_interface_uart
     sensors:
       - packet_interface_sensor
+  - platform: packet_interface
+    packet_interface: packet_interface_network
+    sensors:
+      - packet_interface_sensor

tests/components/packet_interface/hdlc_reliability.cpp

@@ -0,0 +1,464 @@
+#include <gtest/gtest.h>
+#include <cstdint>
+#include <functional>
+#include <memory>
+#include <vector>
+#include "esphome/components/packet_interface/hdlc_reliability.h"
+#include "esphome/core/application.h"
+#include "esphome/core/hal.h"
+#include "esphome/core/helpers.h"
+
+namespace esphome::packet_interface::testing {
+
+// Copies a packet into a vector, for comparing in tests
+static std::vector<uint8_t> to_vector(const esphome::packet_interface::PacketBuffer &data) {
+  std::vector<uint8_t> result(data.size());
+  data.copy_to(result.data(), result.size());
+  return result;
+}
+
+using Frame = std::vector<uint8_t>;
+
+// A link layer that records what is sent, so a test can deliver it to the peer
+class MockLink : public PacketInterface {
+ public:
+  explicit MockLink(size_t max_packet_size = 64) : PacketInterface(max_packet_size) {}
+  bool send_to_interface(const PacketBuffer &data, const PacketMetaData &) override {
+    if (this->budget == 0) {
+      this->refused++;
+      return false;
+    }
+    this->budget--;
+    this->sent.push_back(to_vector(data));
+    return true;
+  }
+  void inject(const Frame &frame) { this->on_receive_from_interface_(PacketBuffer(frame), {}); }
+
+  std::vector<Frame> sent;
+  size_t budget{SIZE_MAX};  // frames accepted before the link refuses, like a full network stack
+  size_t refused{0};
+};
+
+class TestHdlc : public HdlcReliability {
+ public:
+  using HdlcReliability::HdlcReliability;
+  using HdlcReliability::on_timeout_;
+  using HdlcReliability::outstanding_;
+};
+
+struct Peer {
+  explicit Peer(uint8_t queue_length = 4) {
+    this->hdlc = std::make_unique<TestHdlc>(&this->link);
+    this->hdlc->set_max_queue_length(queue_length);
+    this->hdlc->set_max_retries(3);
+    this->hdlc->setup();
+    this->hdlc->add_packet_interface_listener(
+        [this](const PacketBuffer &data, const PacketMetaData &) { this->received.push_back(to_vector(data)); });
+    this->hdlc->add_on_session_state_callback([this](bool connected) { this->states.push_back(connected); });
+  }
+  bool send(const Frame &data) { return this->hdlc->send_to_interface(PacketBuffer(data), {}); }
+
+  MockLink link;
+  std::unique_ptr<TestHdlc> hdlc;
+  std::vector<Frame> received;
+  std::vector<bool> states;
+};
+
+// Returns true to drop a frame on its way from one peer to the other
+using DropFilter = std::function<bool(const Frame &)>;
+
+static bool is_info(const Frame &frame) { return (frame[0] & 1) == 0; }
+static bool is_ack(const Frame &frame) { return (frame[0] & 0x0F) == 0x01; }
+
+// Runs a layer's loop only while it has asked for it, as the main loop does
+static void run_loop(TestHdlc &hdlc) {
+  if (!hdlc.is_idle())
+    hdlc.loop();
+}
+
+// Move frames between the peers and run their loops until nothing more is sent
+static void pump(Peer &a, Peer &b, const DropFilter &drop_a_to_b = nullptr, const DropFilter &drop_b_to_a = nullptr) {
+  for (int i = 0; i != 50; i++) {
+    run_loop(*a.hdlc);
+    run_loop(*b.hdlc);
+    if (a.link.sent.empty() && b.link.sent.empty())
+      return;
+    auto from_a = std::move(a.link.sent);
+    auto from_b = std::move(b.link.sent);
+    a.link.sent.clear();
+    b.link.sent.clear();
+    for (auto &frame : from_a) {
+      if (!drop_a_to_b || !drop_a_to_b(frame))
+        b.link.inject(frame);
+    }
+    for (auto &frame : from_b) {
+      if (!drop_b_to_a || !drop_b_to_a(frame))
+        a.link.inject(frame);
+    }
+  }
+  FAIL() << "Peers did not go quiet";
+}
+
+static Frame make_frame(uint8_t control, const Frame &payload) {
+  Frame frame{control};
+  frame.insert(frame.end(), payload.begin(), payload.end());
+  uint16_t crc = crc16(frame.data(), frame.size());
+  frame.push_back(crc & 0xFF);
+  frame.push_back(crc >> 8);
+  return frame;
+}
+
+// Each test replaces App with a fresh one; the retransmit timer needs its scheduler
+class HdlcReliabilityTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    App.~Application();
+    new (&App) Application();
+    static char name[] = "hdlc-tests";
+    static char friendly_name[] = "";
+    App.pre_setup(name, sizeof(name) - 1, friendly_name, 0);
+  }
+  void TearDown() override {
+    App.~Application();
+    new (&App) Application();  // later tests and the test listener use App
+  }
+};
+
+TEST_F(HdlcReliabilityTest, MaxPacketSizeAllowsForOverhead) {
+  Peer a;
+  EXPECT_EQ(a.hdlc->get_send_capacity(), 4);
+  EXPECT_EQ(a.hdlc->get_max_packet_size(), 64 - HdlcReliability::FRAME_OVERHEAD);
+  EXPECT_EQ(a.link.top(), a.hdlc.get());
+  EXPECT_EQ(a.hdlc->get_capabilities(), CAPABILITY_RELIABILITY);
+}
+
+TEST_F(HdlcReliabilityTest, ResetHandshake) {
+  Peer a, b;
+  a.hdlc->loop();
+  ASSERT_EQ(a.link.sent.size(), 1);
+  EXPECT_EQ(a.link.sent[0], make_frame(0x2F, {}));  // SABM
+  pump(a, b);
+  EXPECT_TRUE(a.hdlc->is_connected());
+  EXPECT_TRUE(b.hdlc->is_connected());
+}
+
+TEST_F(HdlcReliabilityTest, RepeatedSabmBeforeNumberedFramesKeepsQueue) {
+  Peer a, b;
+  pump(a, b);
+  // A frame is queued and sent, but has not reached A, so A has sent no numbered frame
+  ASSERT_TRUE(b.send({0x42}));
+  auto held = std::move(b.link.sent);
+  b.link.sent.clear();
+  EXPECT_EQ(b.hdlc->get_send_capacity(), 3);
+
+  // A repeats its SABM because it did not hear the UA; that is not a restart
+  b.link.inject(make_frame(0x2F, {}));  // SABM
+  EXPECT_TRUE(b.hdlc->is_connected());
+  EXPECT_TRUE(b.states.empty());              // no session lost reported
+  EXPECT_EQ(b.hdlc->get_send_capacity(), 3);  // the queued frame was kept
+  ASSERT_FALSE(b.link.sent.empty());
+  EXPECT_EQ(b.link.sent[0], make_frame(0x63, {}));  // UA, then the frame is sent again
+
+  // The frame is still delivered when it reaches A
+  for (auto &frame : held)
+    a.link.inject(frame);
+  EXPECT_EQ(a.received, std::vector<Frame>{{0x42}});
+}
+
+TEST_F(HdlcReliabilityTest, SabmAfterNumberedFramesIsARestart) {
+  Peer a, b;
+  pump(a, b);
+  // B has heard a numbered frame, so a SABM now means A has started again
+  ASSERT_TRUE(a.send({0x10}));
+  pump(a, b);
+  b.link.inject(make_frame(0x2F, {}));  // SABM
+  EXPECT_TRUE(b.hdlc->is_connected());
+  EXPECT_EQ(b.states, std::vector<bool>{false});
+}
+
+TEST_F(HdlcReliabilityTest, QueuedBeforeConnectIsSentAfter) {
+  Peer a, b;
+  ASSERT_TRUE(a.send({0x01}));
+  ASSERT_TRUE(a.send({0x02}));
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0x01}, {0x02}}));
+}
+
+TEST_F(HdlcReliabilityTest, DeliversInOrderBothWays) {
+  Peer a, b;
+  pump(a, b);
+  a.send({0x10});
+  b.send({0x20});
+  a.send({0x11});
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0x10}, {0x11}}));
+  EXPECT_EQ(a.received, (std::vector<Frame>{{0x20}}));
+}
+
+TEST_F(HdlcReliabilityTest, SequenceNumbersWrap) {
+  Peer a(3), b(3);
+  pump(a, b);
+  std::vector<Frame> expected;
+  for (uint8_t i = 0; i != 20; i++) {
+    expected.push_back({i, static_cast<uint8_t>(i * 3)});
+    ASSERT_TRUE(a.send(expected.back()));
+    if (i % 2 == 1)
+      pump(a, b);
+  }
+  pump(a, b);
+  EXPECT_EQ(b.received, expected);
+}
+
+TEST_F(HdlcReliabilityTest, GapRecoveredByReject) {
+  Peer a, b;
+  pump(a, b);
+  bool dropped = false;
+  a.send({0x01});
+  a.send({0x02});
+  a.send({0x03});
+  pump(a, b, [&dropped](const Frame &frame) {
+    if (dropped || !is_info(frame))
+      return false;
+    dropped = true;
+    return true;
+  });
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0x01}, {0x02}, {0x03}}));
+}
+
+TEST_F(HdlcReliabilityTest, LossRecoveredByTimeout) {
+  Peer a, b;
+  pump(a, b);
+  a.send({0x42});
+  pump(a, b, [](const Frame &frame) { return is_info(frame); });
+  EXPECT_TRUE(b.received.empty());
+  a.hdlc->on_timeout_();
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0x42}}));
+}
+
+TEST_F(HdlcReliabilityTest, LostAckDoesNotDuplicate) {
+  Peer a, b;
+  pump(a, b);
+  a.send({0x42});
+  pump(a, b, nullptr, [](const Frame &frame) { return is_ack(frame); });
+  ASSERT_EQ(b.received.size(), 1);
+  a.hdlc->on_timeout_();
+  pump(a, b);
+  EXPECT_EQ(b.received.size(), 1);
+  // The resend was acknowledged, so the full queue is available again
+  for (int i = 0; i != 4; i++)
+    EXPECT_TRUE(a.send({0x01}));
+}
+
+TEST_F(HdlcReliabilityTest, QueueFull) {
+  Peer a(2), b(2);
+  pump(a, b);
+  EXPECT_TRUE(a.send({0x01}));
+  EXPECT_TRUE(a.send({0x02}));
+  EXPECT_FALSE(a.send({0x03}));
+}
+
+TEST_F(HdlcReliabilityTest, OversizedPacketRejected) {
+  Peer a;
+  EXPECT_FALSE(a.send(Frame(a.hdlc->get_max_packet_size() + 1)));
+}
+
+TEST_F(HdlcReliabilityTest, CrcErrorDropped) {
+  Peer a, b;
+  pump(a, b);
+  Frame frame = make_frame(0x00, {0x55});  // I-frame N(S)=0 N(R)=0
+  frame[1] ^= 0xFF;
+  b.link.inject(frame);
+  EXPECT_TRUE(b.received.empty());
+  b.link.inject(make_frame(0x00, {0x55}));
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0x55}}));
+}
+
+TEST_F(HdlcReliabilityTest, RetriesExhaustedResetsLink) {
+  Peer a, b;
+  pump(a, b);
+  // One frame is delivered first, so b can tell a reset from a repeated SABM
+  ASSERT_TRUE(a.send({0x00}));
+  pump(a, b);
+  ASSERT_EQ(b.received, std::vector<Frame>{{0x00}});
+  a.send({0x01});
+  pump(a, b, [](const Frame &frame) { return is_info(frame); });
+  for (int i = 0; i != 4; i++) {
+    a.hdlc->on_timeout_();
+    pump(a, b, [](const Frame &frame) { return is_info(frame); });
+  }
+  // The unacknowledged frame was discarded and the link was reset, which both report as data lost
+  EXPECT_EQ(b.received, std::vector<Frame>{{0x00}});
+  EXPECT_TRUE(a.hdlc->is_connected());
+  EXPECT_EQ(a.states, std::vector<bool>{false});
+  EXPECT_EQ(b.states, std::vector<bool>{false});
+  a.send({0x02});
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0x00}, {0x02}}));
+}
+
+TEST_F(HdlcReliabilityTest, PeerRestart) {
+  Peer a;
+  auto b = std::make_unique<Peer>();
+  pump(a, *b);
+  a.send({0x01});
+  pump(a, *b);
+  // The peer restarts with fresh sequence numbers
+  b = std::make_unique<Peer>();
+  pump(a, *b);
+  a.send({0x02});
+  b->send({0x03});
+  pump(a, *b);
+  EXPECT_EQ(b->received, (std::vector<Frame>{{0x02}}));
+  EXPECT_EQ(a.received, (std::vector<Frame>{{0x03}}));
+  // The restarted peer's reset discarded what a had not yet had acknowledged
+  EXPECT_EQ(a.states, std::vector<bool>{false});
+  EXPECT_TRUE(b->states.empty());
+}
+
+// Waits past the retry after a refused send, servicing timers as the main loop does
+static void run_send_retry() {
+  const uint32_t start = millis();
+  while (millis() - start < 60) {
+    App.scheduler.call(millis());
+    delay(1);
+  }
+  App.scheduler.call(millis());
+}
+
+TEST_F(HdlcReliabilityTest, RefusedFramesSentAgainWithoutTimeout) {
+  Peer a, b;
+  // Only the retry of a refused send can fire while the test runs, not a retransmit
+  a.hdlc->set_ack_timeout(10000);
+  b.hdlc->set_ack_timeout(10000);
+  for (uint8_t i = 0; i != 3; i++)
+    ASSERT_TRUE(a.send({i}));
+  a.link.budget = 3;  // SABM, UA to the peer's SABM, and the first queued frame
+  pump(a, b);
+  EXPECT_GE(a.link.refused, 1);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0}}));
+  a.link.budget = SIZE_MAX;  // the lower layer accepts again, as when a radio stops receiving
+  // The layer waits for its retry rather than running every loop
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0}}));
+  run_send_retry();
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{0}, {1}, {2}}));
+  EXPECT_EQ(a.hdlc->outstanding_(), 0);
+}
+
+TEST_F(HdlcReliabilityTest, RefusedAckSentAgain) {
+  Peer a, b;
+  a.hdlc->set_ack_timeout(10000);
+  b.hdlc->set_ack_timeout(10000);
+  pump(a, b);
+  a.send({1});
+  for (auto &frame : a.link.sent)
+    b.link.inject(frame);
+  a.link.sent.clear();
+  b.link.budget = 0;
+  b.hdlc->loop();
+  EXPECT_TRUE(b.link.sent.empty());
+  b.link.budget = SIZE_MAX;
+  pump(a, b);
+  EXPECT_EQ(a.hdlc->outstanding_(), 1);  // the RR waits for the retry
+  run_send_retry();
+  pump(a, b);
+  EXPECT_EQ(a.hdlc->outstanding_(), 0);
+}
+
+TEST_F(HdlcReliabilityTest, AckDelayLetsReplyCarryAck) {
+  Peer a, b;
+  b.hdlc->set_ack_delay(100);
+  pump(a, b);
+  a.send({1});
+  for (auto &frame : a.link.sent)
+    b.link.inject(frame);
+  a.link.sent.clear();
+  b.hdlc->loop();
+  EXPECT_TRUE(b.link.sent.empty());  // no RR yet
+  b.send({2});
+  ASSERT_EQ(b.link.sent.size(), 1);
+  EXPECT_TRUE(is_info(b.link.sent[0]));
+  EXPECT_EQ(b.link.sent[0][0] >> 5, 1);  // N(R) acknowledges the frame from a
+  b.link.sent.clear();
+  b.hdlc->loop();
+  EXPECT_TRUE(b.link.sent.empty());  // the RR is no longer owed
+}
+
+TEST_F(HdlcReliabilityTest, MaxRetriesOf255ResetsLink) {
+  Peer a, b;
+  a.hdlc->set_max_retries(255);
+  pump(a, b);
+  a.send({0x01});
+  a.link.sent.clear();
+  for (int i = 0; i != 255; i++) {
+    a.hdlc->on_timeout_();
+    a.link.sent.clear();
+  }
+  EXPECT_TRUE(a.states.empty());
+  a.hdlc->on_timeout_();
+  EXPECT_EQ(a.states, std::vector<bool>{false});
+}
+
+TEST_F(HdlcReliabilityTest, OversizedFrameDropped) {
+  Peer a, b;
+  pump(a, b);
+  // An I-frame, N(S) 0 and N(R) 0, one byte larger than this layer's packets
+  b.link.inject(make_frame(0x00, Frame(b.hdlc->get_max_packet_size() + 1, 0x55)));
+  EXPECT_TRUE(b.received.empty());
+  b.link.inject(make_frame(0x00, Frame(b.hdlc->get_max_packet_size(), 0x55)));
+  EXPECT_EQ(b.received.size(), 1);
+}
+
+TEST_F(HdlcReliabilityTest, LinkTooSmallFailsSetup) {
+  MockLink link(HdlcReliability::FRAME_OVERHEAD);
+  TestHdlc hdlc(&link);
+  EXPECT_EQ(hdlc.get_max_packet_size(), 0);
+  hdlc.setup();
+  EXPECT_TRUE(hdlc.is_failed());
+  Frame packet{1};
+  EXPECT_FALSE(hdlc.send_to_interface(PacketBuffer(packet), {}));
+  EXPECT_EQ(hdlc.get_send_capacity(), 0);
+}
+
+TEST_F(HdlcReliabilityTest, AckDelayTimerSendsAck) {
+  Peer a, b;
+  b.hdlc->set_ack_delay(5);
+  pump(a, b);
+  a.send({1});
+  for (auto &frame : a.link.sent)
+    b.link.inject(frame);
+  a.link.sent.clear();
+  b.hdlc->loop();
+  EXPECT_TRUE(b.link.sent.empty());
+  delay(10);
+  App.scheduler.call(millis());
+  b.hdlc->loop();
+  ASSERT_EQ(b.link.sent.size(), 1);
+  EXPECT_TRUE(is_ack(b.link.sent[0]));
+  EXPECT_EQ(b.link.sent[0][0] >> 5, 1);  // N(R) acknowledges the frame from a
+}
+
+TEST_F(HdlcReliabilityTest, RefusedRejectFallsBackToAck) {
+  Peer a, b;
+  pump(a, b);
+  a.send({1});
+  a.send({2});
+  ASSERT_EQ(a.link.sent.size(), 2);
+  // The first frame is lost, and the REJ for the gap is refused
+  b.link.budget = 0;
+  b.link.inject(a.link.sent[1]);
+  a.link.sent.clear();
+  EXPECT_EQ(b.link.refused, 1);
+  b.link.budget = SIZE_MAX;
+  b.hdlc->loop();
+  ASSERT_EQ(b.link.sent.size(), 1);
+  EXPECT_TRUE(is_ack(b.link.sent[0]));
+  EXPECT_EQ(b.link.sent[0][0] >> 5, 0);
+  a.hdlc->on_timeout_();
+  pump(a, b);
+  EXPECT_EQ(b.received, (std::vector<Frame>{{1}, {2}}));
+}
+
+}  // namespace esphome::packet_interface::testing

tests/components/packet_interface/xxtea_encryption.cpp

@@ -0,0 +1,282 @@
+#include <gtest/gtest.h>
+#include <algorithm>
+#include <cstdint>
+#include <memory>
+#include <vector>
+#include "esphome/components/packet_interface/xxtea_encryption.h"
+#include "esphome/core/application.h"
+
+namespace esphome::packet_interface::encryption_testing {
+
+// Copies a packet into a vector, for comparing in tests
+static std::vector<uint8_t> to_vector(const esphome::packet_interface::PacketBuffer &data) {
+  std::vector<uint8_t> result(data.size());
+  data.copy_to(result.data(), result.size());
+  return result;
+}
+
+using Packet = std::vector<uint8_t>;
+
+// A link layer that records what is sent, so a test can deliver it to the peer
+class MockLink : public PacketInterface {
+ public:
+  explicit MockLink(size_t max_packet_size = 64) : PacketInterface(max_packet_size) {}
+  bool send_to_interface(const PacketBuffer &data, const PacketMetaData &) override {
+    this->sent.push_back(to_vector(data));
+    return true;
+  }
+  void inject(const Packet &packet) { this->on_receive_from_interface_(PacketBuffer(packet), {}); }
+
+  std::vector<Packet> sent;
+};
+
+static constexpr size_t ROLLING_TRAILER_SIZE = 16;
+static constexpr size_t TRAILER_SIZE = 4;
+
+class TestEncryption : public XxteaEncryption {
+ public:
+  using XxteaEncryption::XxteaEncryption;
+  uint32_t get_boot() const { return this->boot_; }
+  void set_counter(uint32_t counter) { this->counter_ = counter; }
+};
+
+struct Peer {
+  explicit Peer(uint32_t key_word = 0x12345678, size_t max_packet_size = 64, bool rolling_code = true)
+      : link(max_packet_size) {
+    this->link.set_name("test_link");
+    this->encryption = std::make_unique<TestEncryption>(&this->link, rolling_code);
+    this->encryption->set_key({key_word, 2, 3, 4, 5, 6, 7, 8});
+    this->encryption->add_packet_interface_listener(
+        [this](const PacketBuffer &data, const PacketMetaData &) { this->received.push_back(to_vector(data)); });
+    this->encryption->setup();
+  }
+  bool send(const Packet &data) { return this->encryption->send_to_interface(PacketBuffer(data), {}); }
+  // Deliver everything sent so far to the peer
+  void deliver_to(Peer &peer) {
+    for (auto &packet : this->link.sent)
+      peer.link.inject(packet);
+    this->link.sent.clear();
+  }
+  // Exchange a packet each way so that each peer echoes the other's boot number
+  void introduce(Peer &peer) {
+    this->send({});
+    this->deliver_to(peer);
+    peer.send({});
+    peer.deliver_to(*this);
+    this->send({});
+    this->deliver_to(peer);
+    this->received.clear();
+    peer.received.clear();
+  }
+
+  MockLink link;
+  std::unique_ptr<TestEncryption> encryption;
+  std::vector<Packet> received;
+};
+
+// Each test replaces App with a fresh one
+class XxteaEncryptionTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    App.~Application();
+    new (&App) Application();
+    static char name[] = "xxtea-tests";
+    static char friendly_name[] = "";
+    App.pre_setup(name, sizeof(name) - 1, friendly_name, 0);
+  }
+  void TearDown() override {
+    App.~Application();
+    new (&App) Application();  // later tests and the test listener use App
+  }
+};
+
+TEST_F(XxteaEncryptionTest, MaxPacketSizeAllowsForTrailerAndWords) {
+  Peer a;
+  EXPECT_EQ(a.encryption->get_max_packet_size(), 64 - ROLLING_TRAILER_SIZE);
+  EXPECT_EQ(a.link.top(), a.encryption.get());
+  EXPECT_TRUE(a.encryption->has_capability(CAPABILITY_ENCRYPTION));
+  EXPECT_FALSE(a.encryption->has_capability(CAPABILITY_SESSION));
+  Peer b(0x12345678, 63);
+  EXPECT_EQ(b.encryption->get_max_packet_size(), 60 - ROLLING_TRAILER_SIZE);
+  Peer c(0x12345678, 64, false);
+  EXPECT_EQ(c.encryption->get_max_packet_size(), 64 - TRAILER_SIZE);
+}
+
+static void round_trip_all_sizes(bool rolling_code, size_t trailer_size) {
+  Peer a(0x12345678, 64, rolling_code), b(0x12345678, 64, rolling_code);
+  a.introduce(b);
+  std::vector<Packet> expected;
+  for (size_t size = 0; size <= a.encryption->get_max_packet_size(); size++) {
+    Packet packet(size);
+    for (size_t i = 0; i != size; i++)
+      packet[i] = static_cast<uint8_t>(size + i);
+    expected.push_back(packet);
+    ASSERT_TRUE(a.send(packet));
+    ASSERT_EQ(a.link.sent.back().size() % 4, 0);
+    ASSERT_GE(a.link.sent.back().size(), std::max<size_t>(8, size + trailer_size));
+  }
+  a.deliver_to(b);
+  EXPECT_EQ(b.received, expected);
+}
+
+TEST_F(XxteaEncryptionTest, RoundTripAllSizes) { round_trip_all_sizes(true, ROLLING_TRAILER_SIZE); }
+
+TEST_F(XxteaEncryptionTest, RoundTripAllSizesWithoutRollingCode) { round_trip_all_sizes(false, TRAILER_SIZE); }
+
+TEST_F(XxteaEncryptionTest, WithoutRollingCodeReplayAccepted) {
+  Peer a(0x12345678, 64, false), b(0x12345678, 64, false);
+  a.send({1});
+  b.link.inject(a.link.sent[0]);
+  b.link.inject(a.link.sent[0]);
+  EXPECT_EQ(b.received, (std::vector<Packet>{{1}, {1}}));
+}
+
+TEST_F(XxteaEncryptionTest, RollingCodeSettingMustMatch) {
+  Peer a(0x12345678, 64, true), b(0x12345678, 64, false);
+  a.send({1, 2, 3, 4, 5, 6, 7, 8});
+  b.send({1, 2, 3, 4, 5, 6, 7, 8});
+  a.deliver_to(b);
+  b.deliver_to(a);
+  EXPECT_TRUE(a.received.empty());
+  EXPECT_TRUE(b.received.empty());
+}
+
+TEST_F(XxteaEncryptionTest, SamePacketEncryptsDifferently) {
+  Peer a;
+  a.send({1, 2, 3, 4});
+  a.send({1, 2, 3, 4});
+  ASSERT_EQ(a.link.sent.size(), 2);
+  EXPECT_NE(a.link.sent[0], a.link.sent[1]);
+}
+
+TEST_F(XxteaEncryptionTest, OversizedPacketRefused) {
+  Peer a;
+  EXPECT_FALSE(a.send(Packet(a.encryption->get_max_packet_size() + 1)));
+  EXPECT_TRUE(a.link.sent.empty());
+}
+
+TEST_F(XxteaEncryptionTest, WrongKeyDropped) {
+  Peer a, b(0x87654321);
+  a.send({1, 2, 3});
+  a.deliver_to(b);
+  EXPECT_TRUE(b.received.empty());
+}
+
+TEST_F(XxteaEncryptionTest, ChangedPacketDropped) {
+  Peer a, b;
+  a.send({1, 2, 3});
+  a.link.sent[0][2] ^= 0x01;
+  a.deliver_to(b);
+  EXPECT_TRUE(b.received.empty());
+}
+
+TEST_F(XxteaEncryptionTest, BadLengthDropped) {
+  Peer a, b;
+  a.send({1, 2, 3});
+  Packet packet = a.link.sent[0];
+  b.link.inject(Packet(packet.begin(), packet.end() - 1));
+  b.link.inject(Packet(8));
+  EXPECT_TRUE(b.received.empty());
+}
+
+TEST_F(XxteaEncryptionTest, ReplayDropped) {
+  Peer a, b;
+  a.introduce(b);
+  a.send({1});
+  Packet first = a.link.sent[0];
+  a.send({2});
+  a.deliver_to(b);
+  b.link.inject(first);
+  EXPECT_EQ(b.received, (std::vector<Packet>{{1}, {2}}));
+}
+
+TEST_F(XxteaEncryptionTest, OlderPacketDropped) {
+  Peer a, b;
+  a.introduce(b);
+  a.send({1});
+  a.send({2});
+  b.link.inject(a.link.sent[1]);
+  b.link.inject(a.link.sent[0]);
+  EXPECT_EQ(b.received, (std::vector<Packet>{{2}}));
+}
+
+TEST_F(XxteaEncryptionTest, BootNumberIncreasesAndPeerRestartAccepted) {
+  Peer b;
+  auto a = std::make_unique<Peer>();
+  uint32_t boot = a->encryption->get_boot();
+  a->introduce(b);
+  a->send({1});
+  a->send({2});
+  a->deliver_to(b);
+  EXPECT_EQ(b.received, (std::vector<Packet>{{1}, {2}}));
+  a = std::make_unique<Peer>();  // the peer restarts, and its counter starts again from 0
+  EXPECT_EQ(a->encryption->get_boot(), boot + 1);
+  a->introduce(b);
+  a->send({3});
+  a->deliver_to(b);
+  EXPECT_EQ(b.received, std::vector<Packet>{{3}});
+}
+
+TEST_F(XxteaEncryptionTest, FirstPacketsDroppedUntilEchoed) {
+  Peer a, b;
+  a.send({1});
+  a.deliver_to(b);
+  EXPECT_TRUE(b.received.empty());  // a does not know b's boot number yet
+  b.send({2});
+  b.deliver_to(a);
+  EXPECT_EQ(a.received, std::vector<Packet>{{2}});  // b learnt a's from the dropped packet
+  a.send({3});
+  a.deliver_to(b);
+  EXPECT_EQ(b.received, std::vector<Packet>{{3}});
+}
+
+TEST_F(XxteaEncryptionTest, PacketsFromBeforeRestartDropped) {
+  Peer a;
+  auto b = std::make_unique<Peer>();
+  a.introduce(*b);
+  a.send({1});
+  a.send({2});
+  std::vector<Packet> recorded = a.link.sent;
+  a.link.sent.clear();
+  b = std::make_unique<Peer>();  // b restarts and forgets a's counter
+  for (auto &packet : recorded)
+    b->link.inject(packet);
+  EXPECT_TRUE(b->received.empty());
+  a.introduce(*b);
+  a.send({3});
+  a.deliver_to(*b);
+  EXPECT_EQ(b->received, std::vector<Packet>{{3}});
+}
+
+TEST_F(XxteaEncryptionTest, LinkTooSmallFailsSetup) {
+  MockLink link(ROLLING_TRAILER_SIZE + 3);
+  TestEncryption encryption(&link, true);
+  EXPECT_EQ(encryption.get_max_packet_size(), 0);
+  encryption.setup();
+  EXPECT_TRUE(encryption.is_failed());
+  Packet packet{1};
+  EXPECT_FALSE(encryption.send_to_interface(PacketBuffer(packet), {}));
+}
+
+TEST_F(XxteaEncryptionTest, SendWithoutBuffersRefused) {
+  MockLink link(64);
+  TestEncryption encryption(&link, false);
+  Packet packet{1};
+  EXPECT_FALSE(encryption.send_to_interface(PacketBuffer(packet), {}));
+  EXPECT_TRUE(link.sent.empty());
+}
+
+TEST_F(XxteaEncryptionTest, CounterWrapStartsNewBoot) {
+  Peer a, b(0x12345678);
+  a.introduce(b);
+  uint32_t boot = a.encryption->get_boot();
+  a.encryption->set_counter(UINT32_MAX);
+  ASSERT_TRUE(a.send({1}));
+  EXPECT_EQ(a.encryption->get_boot(), boot + 1);
+  ASSERT_TRUE(a.send({2}));
+  a.deliver_to(b);
+  // Both were accepted: the last packet of the old boot, then the first of the new one
+  EXPECT_EQ(b.received, (std::vector<Packet>{{1}, {2}}));
+}
+
+}  // namespace esphome::packet_interface::encryption_testing

tests/components/packet_transport/common.yaml

@@ -3,12 +3,14 @@ wifi:
   password: password1
 
 udp:
-  listen_address: 239.0.60.53
-  addresses: ["239.0.60.53"]
+  - id: transport_udp_component
+    listen_address: 239.0.60.53
+    addresses: ["239.0.60.53"]
 
 packet_transport:
   - platform: udp
     id: transport_udp
+    udp_id: transport_udp_component
     update_interval: 5s
     encryption: "our key goes here"
     rolling_code_enable: true

tests/components/runtime_image/test_decode_time_limit.cpp

@@ -0,0 +1,151 @@
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <utility>
+#include <vector>
+
+#include "esphome/components/runtime_image/qoi_decoder.h"
+#include "esphome/components/runtime_image/runtime_image.h"
+
+namespace esphome::runtime_image::testing {
+
+// Big enough that decoding it takes well over DECODE_TIME_LIMIT_MS, little enough to build quickly
+static constexpr uint32_t WIDTH = 4096;
+static constexpr uint32_t HEIGHT = 2048;
+
+static void put_le32(std::vector<uint8_t> &data, size_t offset, uint32_t value) {
+  for (size_t i = 0; i < 4; i++)
+    data[offset + i] = (value >> (8 * i)) & 0xFF;
+}
+
+static void put_be32(std::vector<uint8_t> &data, size_t offset, uint32_t value) {
+  for (size_t i = 0; i < 4; i++)
+    data[offset + i] = (value >> (24 - 8 * i)) & 0xFF;
+}
+
+// A 1-bit BMP with the left half of every row set: eight pixels for each byte read
+static std::vector<uint8_t> make_mono_bmp() {
+  constexpr size_t data_offset = 14 + 40 + 2 * 4;
+  constexpr size_t row_bytes = WIDTH / 8;
+  std::vector<uint8_t> bmp(data_offset + row_bytes * HEIGHT, 0);
+  bmp[0] = 'B';
+  bmp[1] = 'M';
+  put_le32(bmp, 2, bmp.size());
+  put_le32(bmp, 10, data_offset);
+  put_le32(bmp, 14, 40);  // DIB header size
+  put_le32(bmp, 18, WIDTH);
+  put_le32(bmp, 22, HEIGHT);
+  bmp[26] = 1;  // color planes
+  bmp[28] = 1;  // bits per pixel
+  for (size_t row = 0; row < HEIGHT; row++) {
+    for (size_t i = 0; i < row_bytes / 2; i++)
+      bmp[data_offset + row * row_bytes + i] = 0xFF;
+  }
+  return bmp;
+}
+
+// A QOI image of one color: an RGB chunk, then runs of 62 pixels, each run a single byte
+static std::vector<uint8_t> make_solid_qoi() {
+  std::vector<uint8_t> qoi(14, 0);
+  qoi[0] = 'q';
+  qoi[1] = 'o';
+  qoi[2] = 'i';
+  qoi[3] = 'f';
+  put_be32(qoi, 4, WIDTH);
+  put_be32(qoi, 8, HEIGHT);
+  qoi[12] = 3;  // channels
+  qoi.insert(qoi.end(), {0xFE, 30, 120, 200});
+  for (size_t left = WIDTH * HEIGHT - 1; left > 0;) {
+    const size_t run = std::min<size_t>(left, 62);
+    qoi.push_back(0xC0 | (run - 1));
+    left -= run;
+  }
+  qoi.insert(qoi.end(), {0, 0, 0, 0, 0, 0, 0, 1});
+  return qoi;
+}
+
+// Feed the whole image as often as it takes, and return how many calls that was
+static int decode_in_calls(RuntimeImage &img, std::vector<uint8_t> &data) {
+  EXPECT_TRUE(img.begin_decode(data.size()));
+  size_t offset = 0;
+  int calls = 0;
+  while (offset < data.size() && calls < 10000) {
+    const int consumed = img.feed_data(data.data() + offset, data.size() - offset);
+    EXPECT_GT(consumed, 0);
+    if (consumed <= 0)
+      break;
+    offset += consumed;
+    calls++;
+  }
+  EXPECT_EQ(offset, data.size());
+  EXPECT_TRUE(img.end_decode());
+  return calls;
+}
+
+TEST(DecodeTimeLimit, BmpIsDecodedOverSeveralCalls) {
+  RuntimeImage img(BMP, image::IMAGE_TYPE_GRAYSCALE, image::TRANSPARENCY_OPAQUE);
+  auto data = make_mono_bmp();
+  EXPECT_GT(decode_in_calls(img, data), 1) << "the whole image was decoded in one call";
+  ASSERT_EQ(img.get_width(), static_cast<int>(WIDTH));
+  ASSERT_EQ(img.get_height(), static_cast<int>(HEIGHT));
+  for (auto [col, row] : {std::pair{0, 0}, std::pair{1000, 1000}, std::pair{4095, 2047}}) {
+    const uint8_t expected = col < static_cast<int>(WIDTH / 2) ? 255 : 0;
+    EXPECT_EQ(img.get_pixel(col, row).r, expected) << col << "," << row;
+  }
+}
+
+// Bytes after the pixel data are used up, not drawn; here they would be colour indexes past the end of the table
+TEST(DecodeTimeLimit, BmpIgnoresBytesAfterThePixels) {
+  RuntimeImage img(BMP, image::IMAGE_TYPE_RGB, image::TRANSPARENCY_OPAQUE);
+  constexpr size_t data_offset = 14 + 40 + 2 * 4;
+  std::vector<uint8_t> data(data_offset, 0);
+  data[0] = 'B';
+  data[1] = 'M';
+  put_le32(data, 10, data_offset);
+  put_le32(data, 14, 40);  // DIB header size
+  put_le32(data, 18, 2);   // width
+  put_le32(data, 22, 1);   // height
+  data[26] = 1;            // color planes
+  data[28] = 8;            // bits per pixel
+  data[46] = 2;            // colors in the table
+  put_le32(data, 54, 0xFF0000);
+  put_le32(data, 58, 0x0000FF);
+  data.insert(data.end(), {0, 1, 0, 0, 0xFF, 0xFF, 0xFF, 0xFF});
+  put_le32(data, 2, data.size());
+
+  ASSERT_TRUE(img.begin_decode(data.size()));
+  EXPECT_EQ(img.feed_data(data.data(), data.size()), static_cast<int>(data.size()));
+  ASSERT_TRUE(img.end_decode());
+  EXPECT_EQ(img.get_pixel(0, 0).r, 255);
+  EXPECT_EQ(img.get_pixel(1, 0).b, 255);
+}
+
+TEST(DecodeTimeLimit, QoiIsDecodedOverSeveralCalls) {
+  RuntimeImage img(QOI, image::IMAGE_TYPE_RGB, image::TRANSPARENCY_OPAQUE);
+  auto data = make_solid_qoi();
+  EXPECT_GT(decode_in_calls(img, data), 1) << "the whole image was decoded in one call";
+  for (auto [col, row] : {std::pair{0, 0}, std::pair{2000, 1000}, std::pair{4095, 2047}}) {
+    const Color pixel = img.get_pixel(col, row);
+    EXPECT_EQ(pixel.r, 30);
+    EXPECT_EQ(pixel.g, 120);
+    EXPECT_EQ(pixel.b, 200);
+  }
+}
+
+// A chunk split across two calls: the bytes used before the split count towards the decoded total
+TEST(DecodeTimeLimit, QoiCountsTheBytesBeforeASplitChunk) {
+  RuntimeImage img(QOI, image::IMAGE_TYPE_RGB, image::TRANSPARENCY_OPAQUE);
+  std::vector<uint8_t> data = {'q', 'o', 'i', 'f', 0, 0, 0, 2, 0, 0, 0, 1, 3, 0};
+  data.insert(data.end(), {0xFE, 10, 20, 30, 0xFE, 40, 50, 60, 0, 0, 0, 0, 0, 0, 0, 1});
+  QoiDecoder decoder(&img);
+  ASSERT_EQ(decoder.prepare(data.size()), 0);
+
+  // The header and the first chunk, and half of the second
+  EXPECT_EQ(decoder.decode(data.data(), 20), 18);
+  EXPECT_EQ(decoder.get_decoded_bytes(), 18u);
+  EXPECT_EQ(decoder.decode(data.data() + 18, data.size() - 18), static_cast<int>(data.size() - 18));
+  EXPECT_EQ(decoder.get_decoded_bytes(), data.size());
+  EXPECT_TRUE(decoder.is_finished());
+}
+
+}  // namespace esphome::runtime_image::testing

tests/components/runtime_image/test_decoder_reuse.cpp

@@ -5,9 +5,11 @@
 #include <array>
 #include <cstdlib>
 #include <cstring>
+#include <tuple>
 #include <utility>
 #include <vector>
 
+#include "esphome/components/display/display_color_utils.h"
 #include "esphome/components/runtime_image/image_decoder.h"
 #include "esphome/components/runtime_image/jpeg_decoder.h"
 #include "esphome/components/runtime_image/runtime_image.h"
@@ -365,6 +367,23 @@ static std::vector<uint8_t> pixel_bytes(TestableRuntimeImage &img) {
   return std::vector<uint8_t>(start, start + img.get_width_stride() * img.get_height());
 }
 
+// Shrinking a PNG keeps the first source pixel of each span, as the JPEG path does: the even rows and columns
+TEST(RuntimeImageDecoder, ShrunkPngKeepsTheFirstPixelOfEachSpan) {
+  TestableRuntimeImage img(PNG, image::IMAGE_TYPE_RGB, false, 2, 2);
+  ASSERT_TRUE(decode_all(img, PNG_RGB, sizeof(PNG_RGB), PNG));
+  ASSERT_EQ(img.get_width(), 2);
+  ASSERT_EQ(img.get_height(), 2);
+  for (int row = 0; row < 2; row++) {
+    for (int col = 0; col < 2; col++) {
+      const Color pixel = img.get_pixel(col, row);
+      const uint8_t *expected = PNG_RGB_EXPECTED[row * 2][col * 2];
+      EXPECT_EQ(pixel.r, expected[0]) << col << "," << row;
+      EXPECT_EQ(pixel.g, expected[1]) << col << "," << row;
+      EXPECT_EQ(pixel.b, expected[2]) << col << "," << row;
+    }
+  }
+}
+
 TEST(RuntimeImageDecoder, JpegDecoderStaysWarmAcrossDecodes) {
   TestableRuntimeImage img(JPEG);
 
@@ -453,9 +472,37 @@ TEST(RuntimeImageDecoder, JpegDecodesToScaledRgb) {
 }
 
 // Target pixel index each source pixel paints when `source` pixels map onto `target`, the way
-// prepare_rgb565_scaling_ rounds: source n covers targets ceil(n * target / source) up to the next start
+// prepare_draw_ rounds: source n covers targets ceil(n * target / source) up to the next start
 static uint16_t scaled_boundary(int n, int source, int target) { return (n * target + source - 1) / source; }
 
+// Every target pixel of a PNG drawn at a size that is not a whole multiple: enlarged with spans 1 or 2 pixels wide, and
+// shrunk with spans of 0 or 1 pixels
+TEST(RuntimeImageDecoder, ScaledPngPaintsEachSourcePixelOverItsSpan) {
+  // A fixed size keeps the aspect ratio, so both are square
+  for (auto [width, height] : {std::pair{6, 6}, std::pair{3, 3}}) {
+    TestableRuntimeImage img(PNG, image::IMAGE_TYPE_RGB, false, width, height);
+    ASSERT_TRUE(decode_all(img, PNG_RGB, sizeof(PNG_RGB), PNG));
+    ASSERT_EQ(img.get_width(), width);
+    ASSERT_EQ(img.get_height(), height);
+    int painted = 0;
+    for (int m = 0; m < 4; m++) {
+      for (int n = 0; n < 4; n++) {
+        const uint8_t *expected = PNG_RGB_EXPECTED[m][n];
+        for (int y = scaled_boundary(m, 4, height); y < scaled_boundary(m + 1, 4, height); y++) {
+          for (int x = scaled_boundary(n, 4, width); x < scaled_boundary(n + 1, 4, width); x++) {
+            const Color pixel = img.get_pixel(x, y);
+            EXPECT_EQ(pixel.r, expected[0]) << width << "x" << height << " at " << x << "," << y;
+            EXPECT_EQ(pixel.g, expected[1]) << width << "x" << height << " at " << x << "," << y;
+            EXPECT_EQ(pixel.b, expected[2]) << width << "x" << height << " at " << x << "," << y;
+            painted++;
+          }
+        }
+      }
+    }
+    EXPECT_EQ(painted, width * height);
+  }
+}
+
 // JPEGDEC decodes at the smallest of full, 1/2, 1/4 and 1/8 size that still covers the buffer
 TEST(RuntimeImageDecoder, JpegDecodesAtTheSmallestSizeThatCoversTheBuffer) {
   for (auto [size, scale] :
@@ -549,4 +596,152 @@ TEST(RuntimeImageDecoder, SessionFlagsTrackLifecycle) {
   EXPECT_FALSE(img.is_decode_finished()) << "no session means nothing is 'finished'";
 }
 
+// 5x3 QOI whose runs carry on from one row into the next
+static const uint8_t QOI_RUNS[] = {
+    'q',  'o', 'i', 'f', 0, 0, 0, 5, 0, 0, 0, 3, 3, 0,  // header
+    0xFE, 10,  20,  30,                                 // 1 pixel
+    0xC5,                                               // a run of 6
+    0xFE, 200, 100, 50,                                 // 1 pixel
+    0xC6,                                               // a run of 7
+    0,    0,   0,   0,   0, 0, 0, 1,                    // end marker
+};
+
+/// Decode a whole image into img
+static void decode_into(RuntimeImage &img, ImageFormat format, const uint8_t *data, size_t len) {
+  std::vector<uint8_t> buffer(data, data + len);
+  ASSERT_TRUE(img.begin_decode(len, format));
+  size_t offset = 0;
+  while (offset < len) {
+    const int consumed = img.feed_data(buffer.data() + offset, len - offset);
+    ASSERT_GT(consumed, 0);
+    offset += consumed;
+  }
+  ASSERT_TRUE(img.end_decode());
+}
+
+// An opaque RGB565 image is written straight into the buffer. It must hold the same pixels, in the same places, as an
+// RGB image filled through draw_pixel(), at the image's own size and scaled.
+TEST(RuntimeImageDecoder, DirectRgb565MatchesTheGenericPath) {
+  const std::tuple<ImageFormat, const uint8_t *, size_t> images[] = {
+      {BMP, BMP_24BPP, sizeof(BMP_24BPP)},
+      {BMP, BMP_8BPP, sizeof(BMP_8BPP)},
+      {PNG, PNG_RGB, sizeof(PNG_RGB)},
+      {QOI, QOI_RUNS, sizeof(QOI_RUNS)},
+  };
+  for (auto [format, data, len] : images) {
+    for (auto [width, height] : {std::pair{0, 0}, std::pair{7, 5}, std::pair{2, 2}, std::pair{9, 2}}) {
+      RuntimeImage reference(format, image::IMAGE_TYPE_RGB, image::TRANSPARENCY_OPAQUE, nullptr, false, width, height);
+      decode_into(reference, format, data, len);
+      for (bool big_endian : {false, true}) {
+        RuntimeImage img(format, image::IMAGE_TYPE_RGB565, image::TRANSPARENCY_OPAQUE, nullptr, big_endian, width,
+                         height);
+        decode_into(img, format, data, len);
+        ASSERT_EQ(img.get_width(), reference.get_width());
+        ASSERT_EQ(img.get_height(), reference.get_height());
+        const uint8_t *pixels = img.get_data_start();
+        for (int i = 0; i < img.get_width() * img.get_height(); i++) {
+          const Color color = reference.get_pixel(i % img.get_width(), i / img.get_width());
+          const uint16_t expected = display::ColorUtil::color_to_565(color);
+          const uint16_t actual =
+              big_endian ? (pixels[i * 2] << 8 | pixels[i * 2 + 1]) : (pixels[i * 2] | pixels[i * 2 + 1] << 8);
+          EXPECT_EQ(actual, expected) << "image of " << len << " bytes into " << width << "x" << height
+                                      << (big_endian ? " big-endian" : " little-endian") << ", pixel " << i;
+        }
+      }
+    }
+  }
+}
+
+// The runs fill the rows they carry on into
+TEST(RuntimeImageDecoder, QoiRunsCrossRows) {
+  TestableRuntimeImage img(QOI);
+  ASSERT_TRUE(decode_all(img, QOI_RUNS, sizeof(QOI_RUNS)));
+  for (int i = 0; i < 15; i++) {
+    const Color pixel = img.get_pixel(i % 5, i / 5);
+    const bool second = i >= 7;
+    EXPECT_EQ(pixel.r, second ? 200 : 10) << "pixel " << i;
+    EXPECT_EQ(pixel.g, second ? 100 : 20) << "pixel " << i;
+    EXPECT_EQ(pixel.b, second ? 50 : 30) << "pixel " << i;
+  }
+}
+
+// 8x2 1bpp BMP: the top row has its right half set, the bottom row its left half (rows padded to 4 bytes)
+static const uint8_t BMP_1BPP[] = {
+    0x42, 0x4D, 0x46, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3E, 0x00, 0x00, 0x00, 0x28, 0x00, 0x00, 0x00,
+    0x08, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00,
+    0x00, 0x00, 0x13, 0x0B, 0x00, 0x00, 0x13, 0x0B, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0x00, 0xF0, 0x00, 0x00, 0x00, 0x0F, 0x00, 0x00, 0x00,
+};
+
+// BMP has no alpha, so no pixel may come out transparent, whatever transparency the image has
+TEST(RuntimeImageDecoder, BmpPixelsAreOpaque) {
+  const std::pair<const uint8_t *, size_t> images[] = {
+      {BMP_24BPP, sizeof(BMP_24BPP)},
+      {BMP_8BPP, sizeof(BMP_8BPP)},
+      {BMP_1BPP, sizeof(BMP_1BPP)},
+  };
+  for (auto transparency : {image::TRANSPARENCY_ALPHA_CHANNEL, image::TRANSPARENCY_CHROMA_KEY}) {
+    for (auto type : {image::IMAGE_TYPE_RGB, image::IMAGE_TYPE_RGB565}) {
+      for (auto [data, len] : images) {
+        RuntimeImage img(BMP, type, transparency, nullptr, false, 0, 0);
+        decode_into(img, BMP, data, len);
+        for (int y = 0; y < img.get_height(); y++) {
+          for (int x = 0; x < img.get_width(); x++) {
+            EXPECT_EQ(img.get_pixel(x, y).w, 0xFF) << "image of " << len << " bytes, type " << type << ", transparency "
+                                                   << transparency << ", pixel (" << x << "," << y << ")";
+          }
+        }
+      }
+    }
+  }
+}
+
+TEST(RuntimeImageDecoder, Bmp1BppPixels) {
+  TestableRuntimeImage img(BMP, image::TRANSPARENCY_ALPHA_CHANNEL);
+  ASSERT_TRUE(decode_all(img, BMP_1BPP, sizeof(BMP_1BPP)));
+  ASSERT_EQ(img.get_width(), 8);
+  ASSERT_EQ(img.get_height(), 2);
+  for (int x = 0; x < 8; x++) {
+    EXPECT_EQ(img.get_pixel(x, 0).r, x >= 4 ? 0xFF : 0x00) << "pixel (" << x << ",0)";
+    EXPECT_EQ(img.get_pixel(x, 1).r, x < 4 ? 0xFF : 0x00) << "pixel (" << x << ",1)";
+  }
+}
+
+/// Reads a decoder's protected boundary tables
+struct BoundaryTables : ImageDecoder {
+  static size_t x_capacity(const ImageDecoder &decoder) {
+    return (decoder.*(&BoundaryTables::x_boundaries_)).capacity();
+  }
+  static size_t y_capacity(const ImageDecoder &decoder) {
+    return (decoder.*(&BoundaryTables::y_boundaries_)).capacity();
+  }
+  static bool size_valid(const ImageDecoder &decoder) { return decoder.*(&BoundaryTables::size_valid_); }
+  static void prepare_draw(ImageDecoder &decoder, int width, int height) {
+    (decoder.*(&BoundaryTables::prepare_draw_))(width, height);
+  }
+};
+
+// A JPEG decoded at reduced size builds its tables once, for the decoded size, not first for the full size
+TEST(RuntimeImageDecoder, JpegTablesAreBuiltForTheDecodedSize) {
+  TestableRuntimeImage img(JPEG, image::IMAGE_TYPE_RGB565, false, 1, 1);
+  ASSERT_TRUE(decode_all(img, JPEG_GRADIENT, sizeof(JPEG_GRADIENT)));
+  ASSERT_EQ(static_cast<JpegDecoder *>(img.decoder())->get_scale(), 8);
+  EXPECT_EQ(BoundaryTables::x_capacity(*img.decoder()), 2u);
+  EXPECT_EQ(BoundaryTables::y_capacity(*img.decoder()), 2u);
+}
+
+// Without memory for the tables an RGB565 image is drawn pixel by pixel, rather than failing the decode
+TEST(RuntimeImageDecoder, DirectDrawFallsBackWhenTablesCannotBeAllocated) {
+  TestableRuntimeImage img(BMP, image::IMAGE_TYPE_RGB565, false, 0, 0);
+  ASSERT_TRUE(img.begin_decode(sizeof(BMP_24BPP)));
+  BoundaryTables::prepare_draw(*img.decoder(), 3, 2);
+  ASSERT_TRUE(img.decoder()->uses_direct_rgb565());
+  // The x table already fits; a y table of SIZE_MAX entries can never be allocated
+  BoundaryTables::prepare_draw(*img.decoder(), 3, -2);
+  EXPECT_FALSE(img.decoder()->uses_direct_rgb565());
+  EXPECT_TRUE(BoundaryTables::size_valid(*img.decoder())) << "draw() would paint nothing";
+  EXPECT_EQ(BoundaryTables::x_capacity(*img.decoder()), 0u) << "the unused x table must be freed";
+  EXPECT_EQ(BoundaryTables::y_capacity(*img.decoder()), 0u);
+}
+
 }  // namespace esphome::runtime_image::testing

tests/components/runtime_image/test_grayscale_pixel.cpp

@@ -0,0 +1,35 @@
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <cstdlib>
+
+#include "esphome/components/runtime_image/runtime_image.h"
+
+namespace esphome::runtime_image::testing {
+
+class GrayscaleImage : public RuntimeImage {
+ public:
+  GrayscaleImage() : RuntimeImage(BMP, image::IMAGE_TYPE_GRAYSCALE, image::TRANSPARENCY_OPAQUE) {}
+  uint8_t pixel(int x) const { return this->buffer_[x]; }
+};
+
+// The integer weights stay within one step of the floating point formula they replace, and keep white at 255
+TEST(GrayscalePixel, MatchesTheFloatingPointWeights) {
+  GrayscaleImage img;
+  ASSERT_GT(img.resize(256, 1), 0);
+  for (int r = 0; r < 256; r += 5) {
+    for (int g = 0; g < 256; g += 5) {
+      for (int b = 0; b < 256; b += 5) {
+        img.draw_pixel(0, 0, Color(r, g, b));
+        const int expected = static_cast<int>(0.2125 * r + 0.7154 * g + 0.0721 * b);
+        ASSERT_LE(std::abs(img.pixel(0) - expected), 1) << "r=" << r << " g=" << g << " b=" << b;
+      }
+    }
+  }
+  img.draw_pixel(1, 0, Color(255, 255, 255));
+  EXPECT_EQ(img.pixel(1), 255);
+  img.draw_pixel(2, 0, Color(0, 0, 0));
+  EXPECT_EQ(img.pixel(2), 0);
+}
+
+}  // namespace esphome::runtime_image::testing

tests/components/runtime_image/test_png_time_limit.cpp

@@ -0,0 +1,204 @@
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <utility>
+#include <vector>
+
+#include "esphome/components/runtime_image/png_decoder.h"
+#include "esphome/components/runtime_image/runtime_image.h"
+#include "esphome/core/hal.h"
+#include "pngle.h"
+
+namespace esphome::runtime_image::testing {
+
+// 800x600 RGB PNG of a single color (30, 120, 200), 2312 bytes: little data, but many pixels to draw.
+// The same bytes are in tests/components/online_image/test_download_end.cpp.
+static const uint8_t PNG_SOLID[] = {
+    0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x03,
+    0x20, 0x00, 0x00, 0x02, 0x58, 0x08, 0x02, 0x00, 0x00, 0x00, 0x15, 0x14, 0x15, 0x27, 0x00, 0x00, 0x08, 0xCF, 0x49,
+    0x44, 0x41, 0x54, 0x78, 0xDA, 0xED, 0xD6, 0x31, 0x11, 0x00, 0x30, 0x08, 0x00, 0xB1, 0x52, 0x21, 0xE8, 0x44, 0x22,
+    0xB2, 0x30, 0xC1, 0x31, 0x25, 0x12, 0x7E, 0xFA, 0xC8, 0xEA, 0x07, 0x00, 0xC0, 0x9E, 0x2F, 0x01, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58,
+    0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80,
+    0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x83, 0x25, 0x01, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80,
+    0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00,
+    0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16,
+    0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00,
+    0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80,
+    0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30,
+    0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1,
+    0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58,
+    0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02,
+    0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00,
+    0x00, 0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00,
+    0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00,
+    0x06, 0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0,
+    0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x25, 0x01, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06,
+    0x0B, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60,
+    0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B,
+    0x00, 0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01,
+    0x00, 0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00,
+    0x00, 0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00,
+    0x18, 0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00,
+    0x83, 0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18,
+    0x2C, 0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83,
+    0x05, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0,
+    0x00, 0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05,
+    0x00, 0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00,
+    0x00, 0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0x30, 0x58, 0x00, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00,
+    0x60, 0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00,
+    0x0C, 0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x18, 0x2C, 0x00, 0x00, 0x83, 0x05, 0x00, 0x60,
+    0xB0, 0x00, 0x00, 0x30, 0x58, 0x00, 0x00, 0x06, 0x0B, 0x00, 0xC0, 0x60, 0x01, 0x00, 0x60, 0xB0, 0x00, 0x00, 0x0C,
+    0x16, 0x00, 0x80, 0xC1, 0x02, 0x00, 0xC0, 0x60, 0x01, 0x00, 0xDC, 0x19, 0x79, 0xA5, 0x06, 0x0E, 0x33, 0xD4, 0xAF,
+    0xF2, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82,
+};
+
+// A 1x1 RGB PNG whose IEND chunk header crosses the end of the first 64 byte piece
+static const uint8_t PNG_1X1[] = {0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D, 0x49, 0x48,
+                                  0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x08, 0x02, 0x00, 0x00,
+                                  0x00, 0x90, 0x77, 0x53, 0xDE, 0x00, 0x00, 0x00, 0x0C, 0x49, 0x44, 0x41, 0x54, 0x78,
+                                  0x9C, 0x63, 0xF8, 0xCF, 0xC0, 0x00, 0x00, 0x03, 0x01, 0x01, 0x00, 0xC9, 0xFE, 0x92,
+                                  0xEF, 0x00, 0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82};
+
+// Draws that take a millisecond every fourth row, so decoding PNG_SOLID always outlasts the time limit of one call
+class SlowDraws : public PngDecoder, public RuntimeImage {
+ public:
+  static void install(RuntimeImage &image) {
+    auto *decoder = static_cast<PngDecoder *>((image.*&SlowDraws::decoder_).get());
+    pngle_set_draw_callback(decoder->*&SlowDraws::pngle_, draw);
+  }
+
+ private:
+  static void draw(pngle_t *pngle, uint32_t x, uint32_t y, uint32_t w, uint32_t h, const uint8_t rgba[4]) {
+    if (x == 0 && y % 4 == 0) {
+      const uint32_t until = millis() + 2;
+      while (millis() < until) {
+      }
+    }
+    static_cast<PngDecoder *>(pngle_get_user_data(pngle))->draw(x, y, w, h, Color(rgba[0], rgba[1], rgba[2], rgba[3]));
+  }
+};
+
+// One feed_data() call stops after a short time, so a large image is decoded over several calls
+TEST(PngTimeLimit, LargeImageIsDecodedOverSeveralCalls) {
+  RuntimeImage img(PNG, image::IMAGE_TYPE_RGB, image::TRANSPARENCY_OPAQUE);
+  std::vector<uint8_t> data(PNG_SOLID, PNG_SOLID + sizeof(PNG_SOLID));
+  ASSERT_TRUE(img.begin_decode(data.size()));
+  SlowDraws::install(img);
+
+  size_t offset = 0;
+  int calls = 0;
+  while (offset < data.size() && calls < 1000) {
+    const int consumed = img.feed_data(data.data() + offset, data.size() - offset);
+    ASSERT_GT(consumed, 0);
+    offset += consumed;
+    calls++;
+  }
+  EXPECT_GT(calls, 1) << "the whole image was decoded in one call";
+  ASSERT_EQ(offset, data.size());
+  ASSERT_TRUE(img.end_decode());
+
+  ASSERT_EQ(img.get_width(), 800);
+  ASSERT_EQ(img.get_height(), 600);
+  for (auto [col, row] : {std::pair{0, 0}, std::pair{400, 300}, std::pair{799, 599}}) {
+    const Color pixel = img.get_pixel(col, row);
+    EXPECT_EQ(pixel.r, 30);
+    EXPECT_EQ(pixel.g, 120);
+    EXPECT_EQ(pixel.b, 200);
+  }
+}
+
+// A chunk header that crosses the end of a piece does not end the call
+TEST(PngTimeLimit, ChunkAcrossAPieceDoesNotEndTheCall) {
+  RuntimeImage img(PNG, image::IMAGE_TYPE_RGB, image::TRANSPARENCY_OPAQUE);
+  std::vector<uint8_t> data(PNG_1X1, PNG_1X1 + sizeof(PNG_1X1));
+  ASSERT_TRUE(img.begin_decode(data.size()));
+  EXPECT_EQ(img.feed_data(data.data(), data.size()), static_cast<int>(data.size()));
+}
+
+}  // namespace esphome::runtime_image::testing

tests/components/udp/__init__.py

@@ -0,0 +1,6 @@
+from tests.testing_helpers import ComponentManifestOverride
+
+
+def override_manifest(manifest: ComponentManifestOverride) -> None:
+    # benchmark.yaml configures a udp packet_interface, whose to_code waits on the udp component variable.
+    manifest.enable_codegen()

tests/components/udp/benchmark.yaml

@@ -0,0 +1,5 @@
+udp:
+  addresses: ["192.168.1.255"]
+
+packet_interface:
+  - platform: udp

tests/components/udp/udp_packet_interface.cpp

@@ -0,0 +1,78 @@
+#include <gtest/gtest.h>
+
+#include <cstdint>
+#include <vector>
+
+#include "esphome/components/udp/packet_interface/udp_packet_interface.h"
+
+#ifdef USE_NETWORK
+
+namespace esphome::udp::testing {
+
+// Copies a packet into a vector, for comparing in tests
+static std::vector<uint8_t> to_vector(const esphome::packet_interface::PacketBuffer &data) {
+  std::vector<uint8_t> result(data.size());
+  data.copy_to(result.data(), result.size());
+  return result;
+}
+
+using packet_interface::PacketBuffer;
+using packet_interface::PacketMetaData;
+using Packet = std::vector<uint8_t>;
+
+// The copy buffer is a base, so it is set up before the link's constructor sees it
+struct UdpBufferStorage {
+  uint8_t tx_buffer_storage[8]{};
+};
+
+class TestUdp : public UdpBufferStorage, public UdpPacketInterface {
+ public:
+  explicit TestUdp(UDPComponent *udp) : UdpPacketInterface(udp, this->tx_buffer_storage) {
+    this->add_packet_interface_listener(
+        [this](const PacketBuffer &data, const PacketMetaData &) { this->received.push_back(to_vector(data)); });
+  }
+  using UdpPacketInterface::receive_;
+
+  std::vector<Packet> received;
+};
+
+// The udp component is not set up, so it has no destinations and a send does nothing
+class UdpPacketInterfaceTest : public ::testing::Test {
+ protected:
+  UDPComponent udp_;
+  TestUdp link_{&this->udp_};
+};
+
+TEST_F(UdpPacketInterfaceTest, ReceivedPacketsUpToMaxPassedUp) {
+  Packet packet{1, 2, 3, 4, 5, 6, 7, 8};
+  this->link_.receive_(packet);
+  Packet oversized{1, 2, 3, 4, 5, 6, 7, 8, 9};
+  this->link_.receive_(oversized);
+  EXPECT_EQ(this->link_.received, std::vector<Packet>{packet});
+}
+
+TEST_F(UdpPacketInterfaceTest, SendsContiguousAndSplitPackets) {
+  this->link_.setup();
+  Packet packet{1, 2, 3, 4};
+  EXPECT_TRUE(this->link_.send_to_interface(PacketBuffer(packet), {}));
+  uint8_t header = 0;
+  PacketBuffer body(packet);
+  EXPECT_TRUE(this->link_.send_to_interface(PacketBuffer(&header, 1, &body, nullptr, 0), {}));
+  // A packet split across buffers is joined in the copy buffer before it is sent
+  const auto *storage = this->link_.tx_buffer_storage;
+  EXPECT_EQ(Packet(storage, storage + 5), (Packet{0, 1, 2, 3, 4}));
+}
+
+TEST_F(UdpPacketInterfaceTest, OversizedPacketNotSent) {
+  this->link_.setup();
+  Packet packet{1, 2, 3, 4, 5, 6, 7, 8, 9};
+  EXPECT_FALSE(this->link_.send_to_interface(PacketBuffer(packet), {}));
+  uint8_t header = 0;
+  Packet body_data{1, 2, 3, 4, 5, 6, 7, 8};
+  PacketBuffer body(body_data);
+  EXPECT_FALSE(this->link_.send_to_interface(PacketBuffer(&header, 1, &body, nullptr, 0), {}));
+}
+
+}  // namespace esphome::udp::testing
+
+#endif

tests/unit_tests/test_espidf_sbom.py

@@ -386,7 +386,7 @@ def test_external_manifests_skip_other_components(
     components_dir = tmp_path / "components"
     get_sources().append(ExternalSource(components_dir=components_dir))
     _add_external_component(components_dir, "widget")
-    _add_external_component(tmp_path / "builtin", "wifi")
+    _add_external_component(tmp_path / "pkg" / "components", "wifi")
     CORE.loaded_integrations.update({"missing", "namespace"})
     sbom.loader._COMPONENT_CACHE["namespace"] = SimpleNamespace(
         module=SimpleNamespace()
@@ -399,7 +399,9 @@ def test_external_manifests_skip_other_components(
             side_effect=sbom.loader._COMPONENT_CACHE.get,
         ),
         patch.object(
-            sbom.loader, "CORE_COMPONENTS_PATH", (tmp_path / "builtin").resolve()
+            sbom.loader,
+            "CORE_COMPONENTS_PATH",
+            (tmp_path / "pkg" / "components").resolve(),
         ),
     ):
         manifests = sbom._external_manifests()
@@ -703,3 +705,12 @@ def test_checkout_remote_detached(tmp_path: Path) -> None:
             "https://user:token@github.com/someone/esphome.git",
         )
     assert not any(call.args[0][1] == "config" for call in run.call_args_list)
+
+
+def test_external_manifests_esphome_core_is_built_in(
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """The esphome domain resolves to esphome/core, which is still part of ESPHome."""
+    CORE.loaded_integrations.add("esphome")
+    assert sbom._external_manifests() == []
+    assert "SBOM" not in caplog.text

tests/unit_tests/test_mqtt.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from collections.abc import Callable
 import json
 import logging
 from pathlib import Path
@@ -24,13 +25,16 @@ from esphome.const import (
     CONF_CLIENT_CERTIFICATE,
     CONF_CLIENT_CERTIFICATE_KEY,
     CONF_ESPHOME,
+    CONF_LOG_TOPIC,
     CONF_MQTT,
     CONF_NAME,
+    CONF_NAME_ADD_MAC_SUFFIX,
     CONF_PAYLOAD,
     CONF_PORT,
     CONF_RETAIN,
     CONF_SKIP_CERT_CN_CHECK,
     CONF_TOPIC,
+    CONF_TOPIC_PREFIX,
 )
 from esphome.core import EsphomeError
 from esphome.mqtt import (
@@ -99,6 +103,10 @@ def test_show_logs_requests_crash_log_when_device_reports_online(
 
     on_message(client, None, MagicMock(topic="test-device/status", payload=b"offline"))
     client.publish.assert_not_called()
+    # The birth payload on another topic is only a log line
+    on_message(client, None, MagicMock(topic="test-device/debug", payload=b"online"))
+    client.publish.assert_not_called()
+    mock_print.reset_mock()
     on_message(client, None, MagicMock(topic="test-device/status", payload=b"online"))
     client.publish.assert_called_once_with(
         "esphome/logs/test-device", None, retain=False
@@ -136,6 +144,184 @@ def test_show_logs_prints_a_birth_message_inside_the_log_subscription(
     assert mock_print.call_args.args[0].endswith("online")
 
 
+@patch("esphome.mqtt.safe_print")
+@patch("esphome.mqtt.initialize")
+def test_show_logs_follows_the_mac_suffix_of_default_topics(
+    mock_initialize: MagicMock, mock_print: MagicMock
+) -> None:
+    """With name_add_mac_suffix the default topics carry a MAC the CLI cannot know, so any suffix matches."""
+    show_logs(_mac_config(log_topic="test-device/debug"))
+
+    assert mock_initialize.call_args.args[1] == ["+/debug", "+/status"]
+    on_message = mock_initialize.call_args.args[2]
+    client = MagicMock()
+    for topic in (
+        "other-device/status",
+        "test-device/status",
+        "test-device-abc/status",
+    ):
+        _online(on_message, client, topic)
+    client.publish.assert_not_called()
+    _online(on_message, client, "test-device-a1b2c3/status")
+    client.publish.assert_called_once_with(
+        "esphome/logs/test-device-a1b2c3", None, retain=False
+    )
+
+    on_message(client, None, MagicMock(topic="other-device/debug", payload=b"no"))
+    mock_print.assert_not_called()
+    on_message(
+        client, None, MagicMock(topic="test-device-a1b2c3/debug", payload=b"[I]: hi")
+    )
+    assert mock_print.call_args.args[0].endswith("[test-device-a1b2c3][I]: hi")
+
+
+@pytest.mark.parametrize(
+    ("mac_suffix", "options", "cli_topic", "subscriptions"),
+    [
+        pytest.param(
+            True,
+            {"log_topic": "custom/debug", "birth_topic": None},
+            None,
+            ["custom/debug"],
+            id="custom log topic with the mac suffix",
+        ),
+        pytest.param(
+            True,
+            {"birth_topic": None},
+            "test-device/debug",
+            ["test-device/debug"],
+            id="command line topic as written",
+        ),
+        pytest.param(
+            False,
+            {"prefix": "custom", "birth_topic": None},
+            None,
+            ["custom/debug"],
+            id="logs under the topic prefix",
+        ),
+        pytest.param(
+            True,
+            {"prefix": "custom", "log_topic": "test-device/debug"},
+            None,
+            ["test-device/debug", "test-device/status"],
+            id="written out topics under a custom prefix",
+        ),
+    ],
+)
+@patch("esphome.mqtt.initialize")
+def test_show_logs_subscribes_to_literal_topics(
+    mock_initialize: MagicMock,
+    mac_suffix: bool,
+    options: dict,
+    cli_topic: str | None,
+    subscriptions: list[str],
+) -> None:
+    """Topics the firmware does not build from the MAC-suffixed name are subscribed to as written."""
+    config = _mac_config(**options)
+    config[CONF_ESPHOME][CONF_NAME_ADD_MAC_SUFFIX] = mac_suffix
+
+    show_logs(config, topic=cli_topic)
+
+    assert mock_initialize.call_args.args[1] == subscriptions
+
+
+@patch("esphome.mqtt.initialize")
+def test_show_logs_asks_only_the_board_a_command_line_topic_shows(
+    mock_initialize: MagicMock,
+) -> None:
+    """Replaying a crash clears it, so boards whose logs are not shown are left alone."""
+    show_logs(_mac_config(), topic="test-device-a1b2c3/debug")
+
+    assert mock_initialize.call_args.args[1] == [
+        "test-device-a1b2c3/debug",
+        "+/status",
+    ]
+    on_message = mock_initialize.call_args.args[2]
+    client = MagicMock()
+    _online(on_message, client, "test-device-d4e5f6/status")
+    client.publish.assert_not_called()
+    _online(on_message, client, "test-device-a1b2c3/status")
+    client.publish.assert_called_once_with(
+        "esphome/logs/test-device-a1b2c3", None, retain=False
+    )
+
+
+@pytest.mark.parametrize(
+    ("cli_topic", "asked"),
+    [
+        pytest.param(None, True, id="no command line topic"),
+        pytest.param("custom/debug", True, id="the shared custom topic"),
+        pytest.param(
+            "test-device-a1b2c3/debug", False, id="a topic the board never uses"
+        ),
+    ],
+)
+@patch("esphome.mqtt.initialize")
+def test_show_logs_matches_a_command_line_topic_to_the_custom_log_topic(
+    mock_initialize: MagicMock, cli_topic: str | None, asked: bool
+) -> None:
+    """Every board's crash replay goes to the custom log topic, so --topic must show it for a board to be asked."""
+    show_logs(_mac_config(log_topic="custom/debug"), topic=cli_topic)
+
+    assert mock_initialize.call_args.args[1] == [
+        cli_topic or "custom/debug",
+        "+/status",
+    ]
+    on_message = mock_initialize.call_args.args[2]
+    client = MagicMock()
+    _online(on_message, client, "test-device-a1b2c3/status")
+    if asked:
+        client.publish.assert_called_once_with(
+            "esphome/logs/test-device-a1b2c3", None, retain=False
+        )
+    else:
+        client.publish.assert_not_called()
+
+
+@pytest.mark.parametrize(
+    ("mqtt_config", "message"),
+    [
+        pytest.param(None, "MQTT isn't setup", id="no mqtt"),
+        pytest.param({CONF_LOG_TOPIC: None}, "set to null", id="null log topic"),
+        pytest.param(
+            {CONF_LOG_TOPIC: {}}, "not available", id="log topic without topic"
+        ),
+    ],
+)
+@patch("esphome.mqtt.initialize")
+def test_show_logs_without_a_log_topic(
+    mock_initialize: MagicMock,
+    mqtt_config: dict | None,
+    message: str,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Without a log topic there is nothing to follow."""
+    config = _discovery_config()
+    if mqtt_config is None:
+        del config[CONF_MQTT]
+    else:
+        config[CONF_MQTT].update(mqtt_config)
+
+    assert show_logs(config) == 1
+    assert message in caplog.text
+    mock_initialize.assert_not_called()
+
+
+@patch("esphome.mqtt.initialize")
+def test_show_logs_skips_crash_log_requests_no_suffixed_board_hears(
+    mock_initialize: MagicMock,
+) -> None:
+    """A board with the MAC suffix only hears requests named after its own birth message."""
+    show_logs(_mac_config(birth_topic="custom/status", retain=False))
+
+    on_message = mock_initialize.call_args.args[2]
+    on_connect = mock_initialize.call_args.args[3]
+    client = MagicMock()
+    on_connect(client, None, None, 0, None)
+    _online(on_message, client, "custom/status")
+    client.publish.assert_not_called()
+
+
 def test_get_esphome_device_ip_empty_broker() -> None:
     """Test that get_esphome_device_ip raises EsphomeError when broker is empty."""
     config = {
@@ -218,6 +404,34 @@ def test_get_esphome_device_ip_missing_name() -> None:
         get_esphome_device_ip(config)
 
 
+def _mac_config(
+    log_topic: str | None = None,
+    birth_topic: str | None = "test-device/status",
+    retain: bool = True,
+    prefix: str | None = None,
+) -> dict:
+    """A config with name_add_mac_suffix on and the given mqtt topics."""
+    config = _discovery_config()
+    config[CONF_ESPHOME][CONF_NAME_ADD_MAC_SUFFIX] = True
+    mqtt_conf = config[CONF_MQTT]
+    if prefix is not None:
+        mqtt_conf[CONF_TOPIC_PREFIX] = prefix
+    if log_topic is not None:
+        mqtt_conf[CONF_LOG_TOPIC] = {CONF_TOPIC: log_topic}
+    if birth_topic is not None:
+        mqtt_conf[CONF_BIRTH_MESSAGE] = {
+            CONF_TOPIC: birth_topic,
+            CONF_PAYLOAD: "online",
+            CONF_RETAIN: retain,
+        }
+    return config
+
+
+def _online(on_message: Callable[..., None], client: MagicMock, topic: str) -> None:
+    """Deliver the birth payload on a topic."""
+    on_message(client, None, MagicMock(topic=topic, payload=b"online"))
+
+
 def _discovery_config() -> dict:
     return {
         CONF_MQTT: {

tests/unit_tests/test_packet_interface.py

@@ -1,17 +1,35 @@
 """Unit tests for the packet_interface component."""
 
+import hashlib
+from typing import Any
+
 import pytest
 
 from esphome import config_validation as cv
 from esphome.components import packet_interface
 from esphome.components.packet_interface import CONF_MAX_PACKET_SIZE
+from esphome.components.packet_interface.layers import (
+    CONF_RELIABILITY,
+    CONF_SESSION,
+    RELIABILITY,
+    STACK_ORDER,
+    LayerKind,
+    xxtea_encryption,
+)
+from esphome.components.packet_interface.layers.basic_session import CONF_KEEP_ALIVE
+from esphome.components.packet_interface.layers.hdlc_reliability import (
+    CONF_MAX_QUEUE_LENGTH,
+)
 from esphome.components.uart import packet_interface as uart_packet_interface
+from esphome.components.udp import packet_interface as udp_packet_interface
+from esphome.const import CONF_ENCRYPTION
 
 
 @pytest.mark.parametrize(
     ("schema", "default", "limit"),
     [
         (uart_packet_interface.CONFIG_SCHEMA, 508, 4096),
+        (udp_packet_interface.CONFIG_SCHEMA, 508, 508),
     ],
 )
 def test_platform_max_packet_size(
@@ -32,3 +50,167 @@ def test_schema_default(setup_core) -> None:
         packet_interface.PacketInterface, 100
     )
     assert schema({})[CONF_MAX_PACKET_SIZE] == 100
+
+
+def test_reliability_defaults(setup_core) -> None:
+    """An empty reliability key selects the HDLC layer with its defaults."""
+    config = uart_packet_interface.CONFIG_SCHEMA({CONF_RELIABILITY: None})
+    reliability = config[CONF_RELIABILITY]
+    assert reliability["type"] == "hdlc"
+    assert reliability["timeout"].total_milliseconds == 200
+    assert reliability[CONF_MAX_QUEUE_LENGTH] == 4
+    assert reliability["max_retries"] == 5
+
+
+def test_reliability_queue_length_limit(setup_core) -> None:
+    """The queue cannot hold more frames than 3 bit sequence numbers allow."""
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA(
+            {CONF_RELIABILITY: {CONF_MAX_QUEUE_LENGTH: 8}}
+        )
+
+
+def test_reliability_timeout_minimum(setup_core) -> None:
+    """A timeout shorter than a few loop passes cannot work."""
+    uart_packet_interface.CONFIG_SCHEMA({CONF_RELIABILITY: {"timeout": "50ms"}})
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA({CONF_RELIABILITY: {"timeout": "40ms"}})
+
+
+def test_ack_delay_shorter_than_timeout(setup_core) -> None:
+    """The acknowledgement must not wait longer than the peer's timeout."""
+    reliability = uart_packet_interface.CONFIG_SCHEMA(
+        {CONF_RELIABILITY: {"timeout": "500ms", "ack_delay": "100ms"}}
+    )[CONF_RELIABILITY]
+    assert reliability["ack_delay"].total_milliseconds == 100
+    with pytest.raises(cv.Invalid, match="shorter"):
+        uart_packet_interface.CONFIG_SCHEMA(
+            {CONF_RELIABILITY: {"timeout": "500ms", "ack_delay": "500ms"}}
+        )
+
+
+def test_layer_types_registered() -> None:
+    """Importing packet_interface registers the built-in layer types."""
+    assert {kind.key: set(kind.types) for kind in STACK_ORDER} == {
+        CONF_ENCRYPTION: {"xxtea"},
+        CONF_RELIABILITY: {"hdlc"},
+        CONF_SESSION: {"basic"},
+    }
+
+
+async def _build(config: dict, lower: Any) -> Any:
+    return lower
+
+
+def test_registered_type_selectable(setup_core) -> None:
+    """A newly registered layer type can be selected with type."""
+    kind = LayerKind("test_kind", "test")
+    kind.register("test", schema=cv.Schema({}))(_build)
+    config = kind.schema()({"type": "test"})
+    assert config["type"] == "test"
+    assert kind.get_type(config).build is _build
+
+
+def test_duplicate_layer_type_rejected(setup_core) -> None:
+    """Registering a type under a name already in use is an error, not a silent replacement."""
+    kind = LayerKind("test_kind", "test")
+    kind.register("test", schema=cv.Schema({}))(_build)
+    with pytest.raises(ValueError, match="already registered"):
+        kind.register("test", schema=cv.Schema({}))(_build)
+
+
+def test_late_registration_rejected(setup_core) -> None:
+    """A type registered after the schemas were built would be missing from them, so it is an error."""
+    with pytest.raises(ValueError, match="after the schemas were built"):
+        RELIABILITY.register("late", schema=cv.Schema({}))(_build)
+
+
+def test_session_defaults(setup_core) -> None:
+    """An empty session key selects the basic session, timing out after three keep-alives."""
+    session = uart_packet_interface.CONFIG_SCHEMA({CONF_SESSION: None})[CONF_SESSION]
+    assert session["type"] == "basic"
+    assert session[CONF_KEEP_ALIVE].total_milliseconds == 10000
+    assert session["timeout"].total_milliseconds == 30000
+
+
+def test_session_timeout(setup_core) -> None:
+    """The timeout follows keep_alive unless given, and must be longer than it."""
+    session = uart_packet_interface.CONFIG_SCHEMA(
+        {CONF_SESSION: {CONF_KEEP_ALIVE: "2s"}}
+    )[CONF_SESSION]
+    assert session["timeout"].total_milliseconds == 6000
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA(
+            {CONF_SESSION: {CONF_KEEP_ALIVE: "5s", "timeout": "5s"}}
+        )
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA({CONF_SESSION: {CONF_KEEP_ALIVE: "500ms"}})
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA({CONF_SESSION: {CONF_KEEP_ALIVE: "2h"}})
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA({CONF_SESSION: {"timeout": "4h"}})
+
+
+def test_encryption_key_only(setup_core) -> None:
+    """The key can be given on its own, and selects XXTEA."""
+    encryption = uart_packet_interface.CONFIG_SCHEMA({CONF_ENCRYPTION: "secret"})[
+        CONF_ENCRYPTION
+    ]
+    assert encryption["type"] == "xxtea"
+    assert encryption["key"] == "secret"
+    assert encryption["rolling_code_enable"] is False
+
+
+def test_encryption_requires_key(setup_core) -> None:
+    """An encryption layer without a key is rejected."""
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA({CONF_ENCRYPTION: {}})
+    with pytest.raises(cv.Invalid):
+        uart_packet_interface.CONFIG_SCHEMA({CONF_ENCRYPTION: ""})
+
+
+def test_rolling_code_requires_session(setup_core) -> None:
+    """The rolling code needs the session's keep-alives, so the peer sends this device's boot number back."""
+    rolling = {CONF_ENCRYPTION: {"key": "secret", "rolling_code_enable": True}}
+    with pytest.raises(cv.Invalid, match="session"):
+        uart_packet_interface.CONFIG_SCHEMA(rolling)
+    uart_packet_interface.CONFIG_SCHEMA({**rolling, CONF_SESSION: None})
+    uart_packet_interface.CONFIG_SCHEMA({CONF_ENCRYPTION: "secret"})
+
+
+@pytest.mark.parametrize(
+    ("config", "loads"),
+    [
+        ({}, []),
+        ({CONF_RELIABILITY: None, CONF_SESSION: None}, []),
+        ({CONF_SESSION: {"binary_sensor": {"name": "Link"}}}, ["binary_sensor"]),
+        ({CONF_ENCRYPTION: "secret"}, ["xxtea"]),
+    ],
+)
+def test_auto_load_follows_layers(
+    setup_core, config: dict[str, Any], loads: list[str]
+) -> None:
+    """Only the components that the configured layers use are loaded."""
+    validated = uart_packet_interface.CONFIG_SCHEMA(config)
+    assert packet_interface.AUTO_LOAD([validated]) == loads
+
+
+def test_auto_load_without_config() -> None:
+    """Tooling that lists dependencies gets everything a layer could load."""
+    assert packet_interface.AUTO_LOAD() == ["binary_sensor", "xxtea"]
+
+
+def test_xxtea_key_stretched() -> None:
+    """The key comes from PBKDF2 of the key text, not a single hash a captured packet could check guesses against."""
+    key = xxtea_encryption.derive_key("Johnny Cash")
+    digest = hashlib.pbkdf2_hmac(
+        "sha256",
+        b"Johnny Cash",
+        b"esphome packet_interface xxtea",
+        600_000,
+    )
+    assert key == [int.from_bytes(digest[i : i + 4], "little") for i in range(0, 32, 4)]
+    assert len(key) == 8 and all(0 <= word < 2**32 for word in key)
+    assert key != xxtea_encryption.derive_key("Johnny Cash ")
+    sha = hashlib.sha256(b"Johnny Cash").digest()
+    assert key[0] != int.from_bytes(sha[:4], "little")