Merge remote-tracking branch 'origin/dev' into socket-lwip-connect

esphome/components/async_tcp/async_tcp_socket.cpp

@@ -6,7 +6,6 @@
 #include "esphome/components/network/util.h"
 #include "esphome/core/log.h"
 #include <cerrno>
-#include <sys/select.h>
 
 namespace esphome::async_tcp {
 
@@ -42,7 +41,15 @@ bool AsyncClient::connect(const char *host, uint16_t port) {
     return false;
   }
 
-  socket_->setblocking(false);
+  if (socket_->setblocking(false) != 0) {
+    // Capture before the log and close() clobber errno
+    const int saved_errno = errno;
+    ESP_LOGE(TAG, "Failed to set nonblocking: errno %d", saved_errno);
+    close();
+    if (error_cb_)
+      error_cb_(error_arg_, this, saved_errno);
+    return false;
+  }
 
   int err = socket_->connect((struct sockaddr *) &addr, addrlen);
   if (err == 0) {
@@ -97,45 +104,22 @@ void AsyncClient::loop() {
     return;
 
   if (connecting_) {
-    // For connecting, we need to check writability, not readability
-    // The Application's select() only monitors read FDs, so we do our own check here
-    // For ESP platforms lwip_select() might be faster, but this code isn't used
-    // on those platforms anyway. If it was, we'd fix the Application select()
-    // to report writability instead of doing it this way.
-    int fd = socket_->get_fd();
-    if (fd < 0) {
-      ESP_LOGW(TAG, "Invalid socket fd");
-      close();
-      return;
-    }
-
-    fd_set writefds;
-    FD_ZERO(&writefds);
-    FD_SET(fd, &writefds);
-
-    struct timeval tv = {0, 0};
-    int ret = select(fd + 1, nullptr, &writefds, nullptr, &tv);
-
-    if (ret > 0 && FD_ISSET(fd, &writefds)) {
-      int error = 0;
-      socklen_t len = sizeof(error);
-      if (socket_->getsockopt(SOL_SOCKET, SO_ERROR, &error, &len) == 0 && error == 0) {
+    int err = 0;
+    switch (socket::poll_connect(*socket_, err)) {
+      case socket::ConnectPollResult::CONNECT_POLL_RESULT_PENDING:
+        break;
+      case socket::ConnectPollResult::CONNECT_POLL_RESULT_CONNECTED:
         connecting_ = false;
         connected_ = true;
         if (connect_cb_)
           connect_cb_(connect_arg_, this);
-      } else {
-        ESP_LOGW(TAG, "Connection failed: %d", error);
+        break;
+      case socket::ConnectPollResult::CONNECT_POLL_RESULT_ERROR:
+        ESP_LOGW(TAG, "Connection failed: %d", err);
         close();
         if (error_cb_)
-          error_cb_(error_arg_, this, error);
-      }
-    } else if (ret < 0) {
-      const int err = errno;
-      ESP_LOGE(TAG, "Select error: %d", err);
-      close();
-      if (error_cb_)
-        error_cb_(error_arg_, this, err);
+          error_cb_(error_arg_, this, err);
+        break;
     }
   } else if (connected_) {
     // For connected sockets, use the Application's select() results

esphome/components/esphome/ota/ota_esphome.cpp

@@ -444,7 +444,10 @@ void ESPHomeOTAComponent::handle_data_() {
   tv.tv_usec = 0;
   this->client_->setsockopt(SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
   this->client_->setsockopt(SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
-  this->client_->setblocking(true);
+  if (this->client_->setblocking(true) != 0) {
+    this->log_socket_error_(LOG_STR("blocking"));
+    goto error;  // NOLINT(cppcoreguidelines-avoid-goto)
+  }
 
   // Acknowledge auth OK - 1 byte
   this->data_write_byte_(ota::OTA_RESPONSE_AUTH_OK);

esphome/components/socket/bsd_sockets_impl.cpp

@@ -59,13 +59,15 @@ int BSDSocketImpl::close() {
 
 int BSDSocketImpl::setblocking(bool blocking) {
   int fl = ::fcntl(this->fd_, F_GETFL, 0);
+  if (fl < 0) {
+    return fl;
+  }
   if (blocking) {
     fl &= ~O_NONBLOCK;
   } else {
     fl |= O_NONBLOCK;
   }
-  ::fcntl(this->fd_, F_SETFL, fl);
-  return 0;
+  return ::fcntl(this->fd_, F_SETFL, fl);
 }
 
 size_t BSDSocketImpl::getpeername_to(std::span<char, SOCKADDR_STR_LEN> buf) {

esphome/components/socket/headers.h

@@ -205,6 +205,13 @@ static constexpr size_t SOCKADDR_STR_LEN = 46;  // INET6_ADDRSTRLEN
 static constexpr size_t SOCKADDR_STR_LEN = 16;  // INET_ADDRSTRLEN
 #endif
 
+/// Outcome of polling a non-blocking connect(); see socket::poll_connect().
+enum class ConnectPollResult : uint8_t {
+  CONNECT_POLL_RESULT_PENDING,
+  CONNECT_POLL_RESULT_CONNECTED,
+  CONNECT_POLL_RESULT_ERROR,
+};
+
 }  // namespace esphome::socket
 
 #endif

esphome/components/socket/lwip_raw_tcp_impl.cpp

@@ -48,8 +48,33 @@ static const char *const TAG = "socket";
 #ifdef USE_ESP8266
 // optimistic_yield() rate limit in microseconds of CONT time; cheap when hot.
 static constexpr uint32_t ESP8266_YIELD_INTERVAL_US = 1000;
+// Let SYS run so queued WiFi traffic reaches lwip; CONT and SYS are cooperative
+static inline void yield_to_sys() { optimistic_yield(ESP8266_YIELD_INTERVAL_US); }
+#else
+static inline void yield_to_sys() {}
 #endif
 
+// errno for a failed tcp_* call
+static int lwip_err_to_errno(err_t err) {
+  switch (err) {
+    case ERR_MEM:
+      return ENOMEM;
+    case ERR_BUF:
+      return EAGAIN;  // transient, e.g. no free local port
+    case ERR_RTE:
+      return EHOSTUNREACH;  // no route, e.g. no address yet
+    case ERR_VAL:
+    case ERR_ARG:
+      return EINVAL;
+    case ERR_USE:
+      return EADDRINUSE;
+    case ERR_ISCONN:
+      return EISCONN;
+    default:
+      return EIO;
+  }
+}
+
 // set to 1 to enable verbose lwip logging
 #if 0  // NOLINT(readability-avoid-unconditional-preprocessor-if)
 #define LWIP_LOG(msg, ...) ESP_LOGVV(TAG, "socket %p: " msg, this, ##__VA_ARGS__)
@@ -62,8 +87,8 @@ static constexpr uint32_t ESP8266_YIELD_INTERVAL_US = 1000;
 // Must be called before destroying the object that tcp_arg points to —
 // tcp_abort() triggers the err callback synchronously, which would
 // otherwise call back into a partially-destroyed object.
-// tcp_sent/tcp_poll are not cleared because this implementation
-// never registers them.
+// tcp_sent/tcp_poll are never registered and the connect callback cannot
+// fire after abort or close, so neither is cleared.
 static void pcb_detach_abort(struct tcp_pcb *pcb) {
   tcp_arg(pcb, nullptr);
   tcp_recv(pcb, nullptr);
@@ -76,8 +101,7 @@ static void pcb_detach_abort(struct tcp_pcb *pcb) {
 // After tcp_close(), the PCB remains alive during the TCP close handshake
 // (FIN_WAIT, TIME_WAIT states). Without clearing callbacks first, LWIP
 // would call recv/err on a destroyed socket object, corrupting the heap.
-// tcp_sent/tcp_poll are not cleared because this implementation
-// never registers them.
+// Callbacks are left as in pcb_detach_abort().
 // Returns ERR_OK on success; on failure the PCB is aborted instead.
 static err_t pcb_detach_close(struct tcp_pcb *pcb) {
   tcp_arg(pcb, nullptr);
@@ -101,67 +125,51 @@ LWIPRawCommon::~LWIPRawCommon() {
   }
 }
 
+bool LWIPRawCommon::sockaddr2ip_(const struct sockaddr *name, socklen_t addrlen, ip_addr_t *ip, uint16_t *port) const {
+  if (name == nullptr) {
+    errno = EINVAL;
+    return false;
+  }
+#if LWIP_IPV6
+  if (this->family_ == AF_INET6) {
+    if (addrlen < sizeof(sockaddr_in6)) {
+      errno = EINVAL;
+      return false;
+    }
+    auto *addr6 = reinterpret_cast<const sockaddr_in6 *>(name);
+    *port = ntohs(addr6->sin6_port);
+    inet6_addr_to_ip6addr(ip_2_ip6(ip), &addr6->sin6_addr);
+    // ANY lets bind() accept both families; connect() picks the concrete type
+    IP_SET_TYPE_VAL(*ip, IPADDR_TYPE_ANY);
+    return true;
+  }
+#endif
+  if (this->family_ != AF_INET || addrlen < sizeof(sockaddr_in)) {
+    errno = EINVAL;
+    return false;
+  }
+  auto *addr4 = reinterpret_cast<const sockaddr_in *>(name);
+  *port = ntohs(addr4->sin_port);
+  ip_addr_set_ip4_u32(ip, addr4->sin_addr.s_addr);
+  return true;
+}
+
 int LWIPRawCommon::bind(const struct sockaddr *name, socklen_t addrlen) {
   LWIP_LOCK();
   if (this->pcb_ == nullptr) {
     errno = EBADF;
     return -1;
   }
-  if (name == nullptr) {
-    errno = EINVAL;
-    return -1;
-  }
   ip_addr_t ip;
-  in_port_t port;
-#if LWIP_IPV6
-  if (this->family_ == AF_INET) {
-    if (addrlen < sizeof(sockaddr_in)) {
-      errno = EINVAL;
-      return -1;
-    }
-    auto *addr4 = reinterpret_cast<const sockaddr_in *>(name);
-    port = ntohs(addr4->sin_port);
-    ip.type = IPADDR_TYPE_V4;
-    ip.u_addr.ip4.addr = addr4->sin_addr.s_addr;
-    LWIP_LOG("tcp_bind(%p ip=%s port=%u)", this->pcb_, ip4addr_ntoa(&ip.u_addr.ip4), port);
-  } else if (this->family_ == AF_INET6) {
-    if (addrlen < sizeof(sockaddr_in6)) {
-      errno = EINVAL;
-      return -1;
-    }
-    auto *addr6 = reinterpret_cast<const sockaddr_in6 *>(name);
-    port = ntohs(addr6->sin6_port);
-    ip.type = IPADDR_TYPE_ANY;
-    memcpy(&ip.u_addr.ip6.addr, &addr6->sin6_addr.un.u8_addr, 16);
-    LWIP_LOG("tcp_bind(%p ip=%s port=%u)", this->pcb_, ip6addr_ntoa(&ip.u_addr.ip6), port);
-  } else {
-    errno = EINVAL;
+  uint16_t port;
+  if (!this->sockaddr2ip_(name, addrlen, &ip, &port)) {
     return -1;
   }
-#else
-  if (this->family_ != AF_INET) {
-    errno = EINVAL;
-    return -1;
-  }
-  auto *addr4 = reinterpret_cast<const sockaddr_in *>(name);
-  port = ntohs(addr4->sin_port);
-  ip.addr = addr4->sin_addr.s_addr;
-  LWIP_LOG("tcp_bind(%p ip=%u port=%u)", this->pcb_, ip.addr, port);
-#endif
+  LWIP_LOG("tcp_bind(%p ip=%s port=%u)", this->pcb_, ipaddr_ntoa(&ip), port);
   err_t err = tcp_bind(this->pcb_, &ip, port);
-  if (err == ERR_USE) {
-    LWIP_LOG("  -> err ERR_USE");
-    errno = EADDRINUSE;
-    return -1;
-  }
-  if (err == ERR_VAL) {
-    LWIP_LOG("  -> err ERR_VAL");
-    errno = EINVAL;
-    return -1;
-  }
   if (err != ERR_OK) {
     LWIP_LOG("  -> err %d", err);
-    errno = EIO;
+    errno = lwip_err_to_errno(err);
     return -1;
   }
   return 0;
@@ -178,7 +186,7 @@ int LWIPRawCommon::close() {
   this->pcb_ = nullptr;
   if (err != ERR_OK) {
     LWIP_LOG("  -> err %d", err);
-    errno = err == ERR_MEM ? ENOMEM : EIO;
+    errno = lwip_err_to_errno(err);
     return -1;
   }
   return 0;
@@ -205,7 +213,7 @@ int LWIPRawCommon::shutdown(int how) {
   err_t err = tcp_shutdown(this->pcb_, shut_rx, shut_tx);
   if (err != ERR_OK) {
     LWIP_LOG("  -> err %d", err);
-    errno = err == ERR_MEM ? ENOMEM : EIO;
+    errno = lwip_err_to_errno(err);
     return -1;
   }
   return 0;
@@ -425,7 +433,82 @@ void LWIPRawImpl::s_err_fn(void *arg, err_t err) {
   // ERR_ABRT: aborted through tcp_abort or TCP timer
   auto *arg_this = reinterpret_cast<LWIPRawImpl *>(arg);
   ESP_LOGVV(TAG, "socket %p: err(err=%d)", arg_this, err);
+  if (arg_this->connect_err_ == EINPROGRESS) {
+    // Refused (RST) or SYN retries exhausted; written before pcb_ so
+    // poll_connect() never sees a dead pcb without its reason
+    arg_this->connect_err_ = err == ERR_RST ? ECONNREFUSED : ETIMEDOUT;
+  }
   arg_this->pcb_ = nullptr;
+  esphome::wake_loop_any_context();
+}
+
+err_t LWIPRawImpl::s_connected_fn(void *arg, struct tcp_pcb *pcb, err_t err) {
+  // LWIP CALLBACK, same constraints as s_err_fn; err is always ERR_OK
+  auto *arg_this = reinterpret_cast<LWIPRawImpl *>(arg);
+  arg_this->connect_err_ = EISCONN;
+  esphome::wake_loop_any_context();
+  return ERR_OK;
+}
+
+int LWIPRawImpl::connect(const struct sockaddr *addr, socklen_t addrlen) {
+  LWIP_LOCK();
+  if (this->pcb_ == nullptr) {
+    errno = EBADF;
+    return -1;
+  }
+  if (this->connect_err_ == EINPROGRESS || this->connect_err_ == EISCONN) {
+    errno = this->connect_err_ == EINPROGRESS ? EALREADY : EISCONN;
+    return -1;
+  }
+  ip_addr_t ip;
+  uint16_t port;
+  if (!this->sockaddr2ip_(addr, addrlen, &ip, &port)) {
+    return -1;
+  }
+#if LWIP_IPV6
+  // tcp_connect needs a concrete type; a remembered IPv4 peer arrives v4-mapped
+  if (IP_IS_ANY_TYPE_VAL(ip)) {
+    if (ip6_addr_isipv4mappedipv6(ip_2_ip6(&ip))) {
+      unmap_ipv4_mapped_ipv6(ip_2_ip4(&ip), ip_2_ip6(&ip));
+      IP_SET_TYPE_VAL(ip, IPADDR_TYPE_V4);
+    } else {
+      IP_SET_TYPE_VAL(ip, IPADDR_TYPE_V6);
+    }
+  }
+#endif
+  LWIP_LOG("tcp_connect(%p ip=%s port=%u)", this->pcb_, ipaddr_ntoa(&ip), port);
+  err_t err = tcp_connect(this->pcb_, &ip, port, LWIPRawImpl::s_connected_fn);
+  if (err != ERR_OK) {
+    LWIP_LOG("  -> err %d", err);
+    errno = lwip_err_to_errno(err);
+    return -1;
+  }
+  this->connect_err_ = EINPROGRESS;
+  errno = EINPROGRESS;
+  return -1;
+}
+
+ConnectPollResult LWIPRawImpl::poll_connect(int &err_out) const {
+  // pcb_ first; see the ordering note on the declaration
+  if (this->pcb_ == nullptr) {
+    // Only a recorded connect failure carries its own reason
+    const bool failed = this->connect_err_ == ECONNREFUSED || this->connect_err_ == ETIMEDOUT;
+    err_out = failed ? this->connect_err_ : ECONNRESET;
+    return ConnectPollResult::CONNECT_POLL_RESULT_ERROR;
+  }
+  switch (this->connect_err_) {
+    case EINPROGRESS:
+      yield_to_sys();  // so the SYN-ACK is processed between polls
+      return ConnectPollResult::CONNECT_POLL_RESULT_PENDING;
+    case EISCONN:
+      return ConnectPollResult::CONNECT_POLL_RESULT_CONNECTED;
+    case 0:
+      err_out = EINVAL;  // no connect was started
+      return ConnectPollResult::CONNECT_POLL_RESULT_ERROR;
+    default:
+      err_out = this->connect_err_;
+      return ConnectPollResult::CONNECT_POLL_RESULT_ERROR;
+  }
 }
 
 err_t LWIPRawImpl::s_recv_fn(void *arg, struct tcp_pcb *pcb, struct pbuf *pb, err_t err) {
@@ -540,14 +623,11 @@ ssize_t LWIPRawImpl::read_locked_(void *buf, size_t len) {
 }
 
 ssize_t LWIPRawImpl::read(void *buf, size_t len) {
-#ifdef USE_ESP8266
-  // Would block: yield to SYS so queued WiFi RX reaches lwip and this read
-  // may succeed. Without this, inbound segments can sit unprocessed for
-  // seconds while the main loop polls (CONT/SYS are cooperative on ESP8266).
+  // Let queued WiFi RX reach lwip first; otherwise inbound segments can
+  // sit unprocessed for seconds while the main loop polls
   if (this->waiting_for_data_()) {
-    optimistic_yield(ESP8266_YIELD_INTERVAL_US);
+    yield_to_sys();
   }
-#endif
   // See waiting_for_data_() for safety of unlocked reads.
   if (this->recv_timeout_cs_ > 0 && this->waiting_for_data_()) {
     this->wait_for_data_();
@@ -636,12 +716,10 @@ int LWIPRawImpl::internal_output_() {
       return -1;
     }
   }
-#ifdef USE_ESP8266
   // Flushed: yield to SYS so the queued segments reach the WiFi driver
   // instead of waiting seconds for an unrelated SYS slot. Callers only get
   // here after a successful tcp_write, so idle paths never yield.
-  optimistic_yield(ESP8266_YIELD_INTERVAL_US);
-#endif
+  yield_to_sys();
   return 0;
 }
 

esphome/components/socket/lwip_raw_tcp_impl.h

@@ -50,6 +50,8 @@ class LWIPRawCommon {
 
  protected:
   int ip2sockaddr_(ip_addr_t *ip, uint16_t port, struct sockaddr *name, socklen_t *addrlen);
+  /// sockaddr of this socket's family to lwip address and port; false with errno on mismatch
+  bool sockaddr2ip_(const struct sockaddr *name, socklen_t addrlen, ip_addr_t *ip, uint16_t *port) const;
 
   // Member ordering optimized to minimize padding on 32-bit systems
   struct tcp_pcb *pcb_;
@@ -58,7 +60,14 @@ class LWIPRawCommon {
   bool nodelay_ = false;
   sa_family_t family_ = 0;
   uint8_t recv_timeout_cs_ = 0;  // SO_RCVTIMEO in centiseconds (0 = no timeout, max 2.55s)
+  // 0 before connect(), EINPROGRESS while pending, EISCONN once established,
+  // else the failure errno the callbacks recorded; fills the padding byte
+  uint8_t connect_err_ = 0;
+  static_assert(EINPROGRESS < 256 && EISCONN < 256 && ECONNREFUSED < 256 && ECONNRESET < 256 && ETIMEDOUT < 256,
+                "connect_err_ stores errno values in a byte");
 };
+// The connect state must stay in the padding so no socket pays RAM for it
+static_assert(sizeof(LWIPRawCommon) == sizeof(struct tcp_pcb *) + 4, "LWIPRawCommon grew past one word of flags");
 
 /// Connected socket implementation for LWIP raw TCP.
 /// No virtual methods — callers always use the concrete type.
@@ -83,6 +92,12 @@ class LWIPRawImpl : public LWIPRawCommon {
     errno = EOPNOTSUPP;
     return -1;
   }
+  /// Non-blocking: returns -1/EINPROGRESS once the SYN is queued, see poll_connect().
+  /// addr must match the socket family; an IPv4 peer on AF_INET6 arrives v4-mapped.
+  int connect(const struct sockaddr *addr, socklen_t addrlen);
+  // Unlocked like ready(): the callbacks write the error byte before pcb_,
+  // so a torn read only costs one extra poll
+  ConnectPollResult poll_connect(int &err_out) const;
   ssize_t read(void *buf, size_t len);
   ssize_t readv(const struct iovec *iov, int iovcnt);
   ssize_t recvfrom(void *, size_t, sockaddr *, socklen_t *) {
@@ -120,6 +135,7 @@ class LWIPRawImpl : public LWIPRawCommon {
 
   static void s_err_fn(void *arg, err_t err);
   static err_t s_recv_fn(void *arg, struct tcp_pcb *pcb, struct pbuf *pb, err_t err);
+  static err_t s_connected_fn(void *arg, struct tcp_pcb *pcb, err_t err);
 
  protected:
   // True when the socket could receive data but none has arrived yet.
@@ -137,6 +153,9 @@ class LWIPRawImpl : public LWIPRawCommon {
   size_t rx_buf_offset_ = 0;
   bool rx_closed_ = false;
 };
+// rx_buf_, rx_buf_offset_, then rx_closed_ padded to a word
+static_assert(sizeof(LWIPRawImpl) == sizeof(LWIPRawCommon) + sizeof(pbuf *) + sizeof(size_t) + 4,
+              "LWIPRawImpl layout changed");
 
 /// Listening socket implementation for LWIP raw TCP.
 /// Separate from LWIPRawImpl — no virtual dispatch needed.

esphome/components/socket/lwip_sockets_impl.cpp

@@ -49,13 +49,15 @@ int LwIPSocketImpl::close() {
 
 int LwIPSocketImpl::setblocking(bool blocking) {
   int fl = lwip_fcntl(this->fd_, F_GETFL, 0);
+  if (fl < 0) {
+    return fl;
+  }
   if (blocking) {
     fl &= ~O_NONBLOCK;
   } else {
     fl |= O_NONBLOCK;
   }
-  lwip_fcntl(this->fd_, F_SETFL, fl);
-  return 0;
+  return lwip_fcntl(this->fd_, F_SETFL, fl);
 }
 
 size_t LwIPSocketImpl::getpeername_to(std::span<char, SOCKADDR_STR_LEN> buf) {

esphome/components/socket/socket.cpp

@@ -2,6 +2,9 @@
 #if defined(USE_SOCKET_IMPL_LWIP_TCP) || defined(USE_SOCKET_IMPL_LWIP_SOCKETS) || defined(USE_SOCKET_IMPL_BSD_SOCKETS)
 #include <cerrno>
 #include <cstring>
+#ifdef USE_SOCKET_IMPL_BSD_SOCKETS
+#include <sys/select.h>
+#endif
 #include <string>
 #include "esphome/core/log.h"
 #include "esphome/core/application.h"
@@ -165,7 +168,10 @@ socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const char *ip_
 #else
     // Use LWIP-specific functions
     ip6_addr_t ip6;
-    inet6_aton(ip_address, &ip6);
+    if (inet6_aton(ip_address, &ip6) == 0) {
+      errno = EINVAL;
+      return 0;
+    }
     memcpy(server->sin6_addr.un.u32_addr, ip6.addr, sizeof(ip6.addr));
 #endif
     return sizeof(sockaddr_in6);
@@ -185,12 +191,58 @@ socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const char *ip_
     return 0;
   }
 #else
-  server->sin_addr.s_addr = inet_addr(ip_address);
+  // Unlike inet_addr(), inet_aton() can signal failure while still
+  // accepting the broadcast address 255.255.255.255
+  if (inet_aton(ip_address, &server->sin_addr) == 0) {
+    errno = EINVAL;
+    return 0;
+  }
 #endif
   server->sin_port = htons(port);
   return sizeof(sockaddr_in);
 }
 
+#if defined(USE_SOCKET_IMPL_BSD_SOCKETS) || defined(USE_SOCKET_IMPL_LWIP_SOCKETS)
+ConnectPollResult poll_connect(Socket &sock, int &err_out) {
+  int fd = sock.get_fd();
+  if (fd < 0 || fd >= FD_SETSIZE) {
+    // FD_SET on either is undefined behavior
+    err_out = EBADF;
+    return ConnectPollResult::CONNECT_POLL_RESULT_ERROR;
+  }
+  // Connect completion is a write event; the main loop only selects on reads
+  fd_set writefds;
+  FD_ZERO(&writefds);
+  FD_SET(fd, &writefds);
+  struct timeval tv = {0, 0};
+#ifdef USE_SOCKET_IMPL_LWIP_SOCKETS
+  // LWIP_COMPAT_SOCKETS may be off (LibreTiny), so use the lwip symbol directly
+  int ret = lwip_select(fd + 1, nullptr, &writefds, nullptr, &tv);
+#else
+  // Global-scope select: the entity namespace esphome::select shadows it here
+  int ret = ::select(fd + 1, nullptr, &writefds, nullptr, &tv);
+#endif
+  if (ret < 0) {
+    err_out = errno;
+    return ConnectPollResult::CONNECT_POLL_RESULT_ERROR;
+  }
+  if (ret == 0) {
+    return ConnectPollResult::CONNECT_POLL_RESULT_PENDING;
+  }
+  int error = 0;
+  socklen_t len = sizeof(error);
+  if (sock.getsockopt(SOL_SOCKET, SO_ERROR, &error, &len) != 0) {
+    err_out = errno;
+    return ConnectPollResult::CONNECT_POLL_RESULT_ERROR;
+  }
+  if (error != 0) {
+    err_out = error;
+    return ConnectPollResult::CONNECT_POLL_RESULT_ERROR;
+  }
+  return ConnectPollResult::CONNECT_POLL_RESULT_CONNECTED;
+}
+#endif
+
 socklen_t set_sockaddr_any(struct sockaddr *addr, socklen_t addrlen, uint16_t port) {
 #if USE_NETWORK_IPV6
   if (addrlen < sizeof(sockaddr_in6)) {

esphome/components/socket/socket.h

@@ -145,6 +145,14 @@ inline socklen_t set_sockaddr(struct sockaddr *addr, socklen_t addrlen, const st
 /// Set a sockaddr to the any address and specified port for the IP version used by socket_ip().
 socklen_t set_sockaddr_any(struct sockaddr *addr, socklen_t addrlen, uint16_t port);
 
+/// Poll a connect() that returned EINPROGRESS. On error, err_out is SO_ERROR (or
+/// errno) on fd implementations and the failure the callbacks recorded on raw lwip.
+#ifdef USE_SOCKET_IMPL_LWIP_TCP
+inline ConnectPollResult poll_connect(Socket &sock, int &err_out) { return sock.poll_connect(err_out); }
+#else
+ConnectPollResult poll_connect(Socket &sock, int &err_out);
+#endif
+
 /// Format sockaddr into caller-provided buffer, returns length written (excluding null)
 size_t format_sockaddr_to(const struct sockaddr *addr_ptr, socklen_t len, std::span<char, SOCKADDR_STR_LEN> buf);
 

esphome/components/udp/udp_component.cpp

@@ -13,7 +13,12 @@ void UDPComponent::setup() {
 #if defined(USE_SOCKET_IMPL_BSD_SOCKETS) || defined(USE_SOCKET_IMPL_LWIP_SOCKETS)
   for (const auto &address : this->addresses_) {
     struct sockaddr saddr {};
-    socket::set_sockaddr(&saddr, sizeof(saddr), address, this->broadcast_port_);
+    if (socket::set_sockaddr(&saddr, sizeof(saddr), address, this->broadcast_port_) == 0) {
+      ESP_LOGW(TAG, "Invalid address %s", address);
+      // A dropped address silently receives nothing; surface the misconfiguration
+      this->status_set_warning(LOG_STR("invalid address"));
+      continue;
+    }
     this->sockaddrs_.push_back(saddr);
   }
   // set up broadcast socket
@@ -94,7 +99,11 @@ void UDPComponent::setup() {
   // 8266 and RP2040 `Duino
   for (const auto &address : this->addresses_) {
     auto ipaddr = IPAddress();
-    ipaddr.fromString(address);
+    if (!ipaddr.fromString(address)) {
+      ESP_LOGW(TAG, "Invalid address %s", address);
+      this->status_set_warning(LOG_STR("invalid address"));
+      continue;
+    }
     this->ipaddrs_.push_back(ipaddr);
   }
   if (this->should_listen_)

esphome/components/wake_on_lan/wake_on_lan.cpp

@@ -34,6 +34,10 @@ void WakeOnLanButton::press_action() {
   struct sockaddr_storage saddr {};
   auto addr_len =
       socket::set_sockaddr(reinterpret_cast<sockaddr *>(&saddr), sizeof(saddr), "255.255.255.255", this->port_);
+  if (addr_len == 0) {
+    ESP_LOGW(TAG, "Invalid broadcast address");
+    return;
+  }
   uint8_t buffer[6 + sizeof this->macaddr_ * 16];
   memcpy(buffer, PREFIX, sizeof(PREFIX));
   for (size_t i = 0; i != 16; i++) {

tests/components/socket/test-ipv6.rp2040-ard.yaml

@@ -0,0 +1,4 @@
+substitutions:
+  network_enable_ipv6: "true"
+
+<<: !include common.yaml

tests/integration/fixtures/socket_set_sockaddr.yaml

@@ -0,0 +1,17 @@
+esphome:
+  name: socket-set-sockaddr
+  on_boot:
+    then:
+      - lambda: |-
+          // 0 for text that is not an address, the length otherwise, broadcast included
+          struct sockaddr_storage addr;
+          auto *sa = reinterpret_cast<struct sockaddr *>(&addr);
+          ESP_LOGI("test", "SET_SOCKADDR invalid=%u valid=%u broadcast=%u",
+                   (unsigned) socket::set_sockaddr(sa, sizeof(addr), "not an address", 1234),
+                   (unsigned) socket::set_sockaddr(sa, sizeof(addr), "192.0.2.1", 1234),
+                   (unsigned) socket::set_sockaddr(sa, sizeof(addr), "255.255.255.255", 1234));
+
+host:
+api:
+logger:
+  level: INFO

tests/integration/fixtures/uart_mock_modbus_mesh.yaml

@@ -17,10 +17,10 @@ uart:
   baud_rate: 115200
   port: /dev/null
 
-# Shared 3-bus mesh (see the shared_yaml markers): addr 1 = typed registers
-# backed by writable globals, addr 5 = the read/write 0x17 target, addr 2/3/6
-# on the second server hub. auto_start everywhere: the controller polls at
-# boot, so the forwarding must already be live or early requests generate warnings.
+# Shared 3-bus mesh (see the shared_yaml markers): addr 1 = typed read-only
+# registers, addr 5 = the read/write 0x17 target, addr 2/3 on the second
+# server hub. auto_start everywhere: the controller polls at boot, so the
+# forwarding must already be live or early requests generate warnings.
 # Every test presses Start Scenario, so all merged actions fire in every test.
 uart_mock:
   - id: virtual_uart_server
@@ -64,54 +64,6 @@ globals:
   - id: stored_1
     type: uint16_t
     initial_value: "0"
-  - id: stored_u_word
-    type: uint16_t
-    initial_value: "99"
-  - id: stored_u_word_s
-    type: uint16_t
-    initial_value: "4660"
-  - id: stored_s_word
-    type: int16_t
-    initial_value: "-99"
-  - id: stored_s_word_s
-    type: int16_t
-    initial_value: "-2"
-  - id: stored_u_dword
-    type: uint32_t
-    initial_value: "16909060"
-  - id: stored_s_dword
-    type: int32_t
-    initial_value: "-16909060"
-  - id: stored_u_dword_r
-    type: uint32_t
-    initial_value: "67305985"
-  - id: stored_s_dword_r
-    type: int32_t
-    initial_value: "-67305985"
-  - id: stored_u_qword
-    type: uint64_t
-    initial_value: "72623859790382856"
-  - id: stored_s_qword
-    type: int64_t
-    initial_value: "-72623859790382856"
-  - id: stored_u_qword_r
-    type: uint64_t
-    initial_value: "578437695752307201"
-  - id: stored_s_qword_r
-    type: int64_t
-    initial_value: "-578437695752307201"
-  - id: stored_fp32
-    type: float
-    initial_value: "3.14"
-  - id: stored_fp32_r
-    type: float
-    initial_value: "2.5"
-  - id: stored_bit_2
-    type: bool
-    initial_value: "false"
-  - id: stored_bit_3
-    type: bool
-    initial_value: "true"
 
 modbus:
   - uart_id: virtual_uart_server
@@ -138,10 +90,6 @@ modbus_controller:
     modbus_id: virtual_modbus_client
     id: modbus_controller_3
     update_interval: 1s
-  - address: 6
-    modbus_id: virtual_modbus_client
-    id: modbus_controller_6
-    update_interval: 1s
 
 modbus_server:
   - address: 1
@@ -149,60 +97,46 @@ modbus_server:
     registers:
       - address: 0x01
         value_type: U_WORD
-        read_lambda: return id(stored_u_word);
-        write_lambda: id(stored_u_word) = x; return true;
+        read_lambda: return 99;
       - address: 0x02
         value_type: U_WORD_S
-        read_lambda: return id(stored_u_word_s);
-        write_lambda: id(stored_u_word_s) = x; return true;
+        read_lambda: return 4660;
       - address: 0x03
         value_type: S_WORD
-        read_lambda: return id(stored_s_word);
-        write_lambda: id(stored_s_word) = x; return true;
+        read_lambda: return -99;
       - address: 0x04
         value_type: S_WORD_S
-        read_lambda: return id(stored_s_word_s);
-        write_lambda: id(stored_s_word_s) = x; return true;
+        read_lambda: return -2;
       - address: 0x05
         value_type: U_DWORD
-        read_lambda: return id(stored_u_dword);
-        write_lambda: id(stored_u_dword) = x; return true;
+        read_lambda: return 16909060;
       - address: 0x08
         value_type: S_DWORD
-        read_lambda: return id(stored_s_dword);
-        write_lambda: id(stored_s_dword) = x; return true;
+        read_lambda: return -16909060;
       - address: 0x0B
         value_type: U_DWORD_R
-        read_lambda: return id(stored_u_dword_r);
-        write_lambda: id(stored_u_dword_r) = x; return true;
+        read_lambda: return 67305985;
       - address: 0x0E
         value_type: S_DWORD_R
-        read_lambda: return id(stored_s_dword_r);
-        write_lambda: id(stored_s_dword_r) = x; return true;
+        read_lambda: return -67305985;
       - address: 0x11
         value_type: U_QWORD
-        read_lambda: return id(stored_u_qword);
-        write_lambda: id(stored_u_qword) = x; return true;
+        read_lambda: return 72623859790382856;
       - address: 0x16
         value_type: S_QWORD
-        read_lambda: return id(stored_s_qword);
-        write_lambda: id(stored_s_qword) = x; return true;
+        read_lambda: return -72623859790382856;
       - address: 0x1B
         value_type: U_QWORD_R
-        read_lambda: return id(stored_u_qword_r);
-        write_lambda: id(stored_u_qword_r) = x; return true;
+        read_lambda: return 578437695752307201;
       - address: 0x20
         value_type: S_QWORD_R
-        read_lambda: return id(stored_s_qword_r);
-        write_lambda: id(stored_s_qword_r) = x; return true;
+        read_lambda: return -578437695752307201;
       - address: 0x25
         value_type: FP32
-        read_lambda: return id(stored_fp32);
-        write_lambda: id(stored_fp32) = x; return true;
+        read_lambda: return 3.14;
       - address: 0x28
         value_type: FP32_R
-        read_lambda: return id(stored_fp32_r);
-        write_lambda: id(stored_fp32_r) = x; return true;
+        read_lambda: return 3.14;
   - address: 5
     modbus_id: virtual_modbus_server
     registers:
@@ -231,19 +165,6 @@ modbus_server:
       - address: 0x01
         value_type: U_WORD
         read_lambda: return 929;
-  - address: 6
-    modbus_id: virtual_modbus_server_2
-    bits:
-      - address: 0x00
-        read_lambda: return true;
-      - address: 0x01
-        read_lambda: return false;
-      - address: 0x02
-        read_lambda: return id(stored_bit_2);
-        write_lambda: id(stored_bit_2) = x; return true;
-      - address: 0x03
-        read_lambda: return id(stored_bit_3);
-        write_lambda: id(stored_bit_3) = x; return true;
 
 sensor:
   - platform: modbus_controller
@@ -359,183 +280,6 @@ sensor:
     name: "client_read_1"
     id: client_read_1
 
-# The number schema caps min/max at 16777215 (float32 integer precision), so
-# the large dword/qword baselines cannot be written back through these numbers.
-number:
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_u_word"
-    address: 0x01
-    register_type: holding
-    value_type: U_WORD
-    min_value: 0
-    max_value: 65535
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_u_word_s"
-    address: 0x02
-    register_type: holding
-    value_type: U_WORD_S
-    min_value: 0
-    max_value: 65535
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_s_word"
-    address: 0x03
-    register_type: holding
-    value_type: S_WORD
-    min_value: -16777215
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_s_word_s"
-    address: 0x04
-    register_type: holding
-    value_type: S_WORD_S
-    min_value: -16777215
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_u_dword"
-    address: 0x05
-    register_type: holding
-    value_type: U_DWORD
-    min_value: 0
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_s_dword"
-    address: 0x08
-    register_type: holding
-    value_type: S_DWORD
-    min_value: -16777215
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_u_dword_r"
-    address: 0x0B
-    register_type: holding
-    value_type: U_DWORD_R
-    min_value: 0
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_s_dword_r"
-    address: 0x0E
-    register_type: holding
-    value_type: S_DWORD_R
-    min_value: -16777215
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_u_qword"
-    address: 0x11
-    register_type: holding
-    value_type: U_QWORD
-    min_value: 0
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_s_qword"
-    address: 0x16
-    register_type: holding
-    value_type: S_QWORD
-    min_value: -16777215
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_u_qword_r"
-    address: 0x1B
-    register_type: holding
-    value_type: U_QWORD_R
-    min_value: 0
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_s_qword_r"
-    address: 0x20
-    register_type: holding
-    value_type: S_QWORD_R
-    min_value: -16777215
-    max_value: 16777215
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_fp32"
-    address: 0x25
-    register_type: holding
-    value_type: FP32
-    min_value: -16777215
-    max_value: 16777215
-    step: 0.01
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_1
-    name: "write_fp32_r"
-    address: 0x28
-    register_type: holding
-    value_type: FP32_R
-    min_value: -16777215
-    max_value: 16777215
-    step: 0.01
-
-# The four bits are read both as coils (FC 0x01) and discrete inputs (FC 0x02);
-# the server serves both from one shared table, so the two views must agree.
-binary_sensor:
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_coil_0"
-    address: 0x00
-    register_type: coil
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_coil_1"
-    address: 0x01
-    register_type: coil
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_coil_2"
-    address: 0x02
-    register_type: coil
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_coil_3"
-    address: 0x03
-    register_type: coil
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_di_0"
-    address: 0x00
-    register_type: discrete_input
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_di_1"
-    address: 0x01
-    register_type: discrete_input
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_di_2"
-    address: 0x02
-    register_type: discrete_input
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "bit_di_3"
-    address: 0x03
-    register_type: discrete_input
-
-# write_bit_2 uses the single-coil write (FC 0x05); write_bit_3 opts into the
-# multiple-coils write (FC 0x0F) so both server write paths are exercised.
-switch:
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "write_bit_2"
-    address: 0x02
-    register_type: coil
-  - platform: modbus_controller
-    modbus_controller_id: modbus_controller_6
-    name: "write_bit_3"
-    address: 0x03
-    register_type: coil
-    use_write_multiple: true
-
 button:
   - platform: template
     name: "Start Scenario"

tests/integration/fixtures/uart_mock_modbus_server_controller_bits.yaml

@@ -0,0 +1,147 @@
+esphome:
+  name: uart-mock-modbus-srv-bits
+
+host:
+api:
+logger:
+  level: VERBOSE
+
+external_components:
+  - source:
+      type: local
+      path: EXTERNAL_COMPONENT_PATH
+
+# Dummy uart entry to satisfy modbus's DEPENDENCIES = ["uart"]
+# The actual UART bus used is the uart_mock component below
+uart:
+  baud_rate: 115200
+  port: /dev/null
+
+uart_mock:
+  - id: virtual_uart_server
+    baud_rate: 9600
+    # auto_start must be true for loopback fixtures: the modbus controller
+    # polls on its update_interval immediately at boot, so the uart_mock
+    # forwarding must already be active or early requests are lost and
+    # generate modbus warnings.
+    auto_start: true
+    debug:
+    on_tx:
+      - then:
+          - uart_mock.inject_rx:
+              id: virtual_uart_controller
+              data: !lambda return data;
+  - id: virtual_uart_controller
+    baud_rate: 9600
+    auto_start: true # See comment on virtual_uart_server above
+    debug:
+    on_tx:
+      - then:
+          - uart_mock.inject_rx:
+              id: virtual_uart_server
+              data: !lambda return data;
+
+globals:
+  - id: stored_bit_2
+    type: bool
+    initial_value: "false"
+  - id: stored_bit_3
+    type: bool
+    initial_value: "true"
+
+modbus:
+  - uart_id: virtual_uart_server
+    id: virtual_modbus_server
+    role: server
+  - uart_id: virtual_uart_controller
+    id: virtual_modbus_controller
+    role: client
+    turnaround_time: 10ms
+
+modbus_controller:
+  - address: 1
+    modbus_id: virtual_modbus_controller
+    update_interval: 1s
+    id: modbus_controller_1
+
+modbus_server:
+  - address: 1
+    modbus_id: virtual_modbus_server
+    id: modbus_server_1
+    bits:
+      - address: 0x00
+        read_lambda: return true;
+      - address: 0x01
+        read_lambda: return false;
+      - address: 0x02
+        read_lambda: return id(stored_bit_2);
+        write_lambda: id(stored_bit_2) = x; return true;
+      - address: 0x03
+        read_lambda: return id(stored_bit_3);
+        write_lambda: id(stored_bit_3) = x; return true;
+
+# The same four bits are read both as coils (FC 0x01) and as discrete inputs
+# (FC 0x02): the server serves both from one shared bit table, so the two
+# views must always agree.
+binary_sensor:
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_coil_0"
+    address: 0x00
+    register_type: coil
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_coil_1"
+    address: 0x01
+    register_type: coil
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_coil_2"
+    address: 0x02
+    register_type: coil
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_coil_3"
+    address: 0x03
+    register_type: coil
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_di_0"
+    address: 0x00
+    register_type: discrete_input
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_di_1"
+    address: 0x01
+    register_type: discrete_input
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_di_2"
+    address: 0x02
+    register_type: discrete_input
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "bit_di_3"
+    address: 0x03
+    register_type: discrete_input
+
+# write_bit_2 uses the single-coil write (FC 0x05); write_bit_3 opts into the
+# multiple-coils write (FC 0x0F) so both server write paths are exercised.
+switch:
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_bit_2"
+    address: 0x02
+    register_type: coil
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_bit_3"
+    address: 0x03
+    register_type: coil
+    use_write_multiple: true
+
+button:
+  - platform: template
+    name: "Start Scenario"
+    id: start_scenario_btn
+    # This test does not have anything to start (mock is autostart)

tests/integration/fixtures/uart_mock_modbus_server_controller_write.yaml

@@ -0,0 +1,371 @@
+esphome:
+  name: uart-mock-modbus-srv-write
+
+host:
+api:
+logger:
+  level: VERBOSE
+
+external_components:
+  - source:
+      type: local
+      path: EXTERNAL_COMPONENT_PATH
+
+# Dummy uart entry to satisfy modbus's DEPENDENCIES = ["uart"]
+# The actual UART bus used is the uart_mock component below
+uart:
+  baud_rate: 115200
+  port: /dev/null
+
+uart_mock:
+  - id: virtual_uart_server
+    baud_rate: 9600
+    # auto_start must be true for loopback fixtures: the modbus controller
+    # polls on its update_interval immediately at boot, so the uart_mock
+    # forwarding must already be active or early requests are lost and
+    # generate modbus warnings.
+    auto_start: true
+    debug:
+    on_tx:
+      - then:
+          - uart_mock.inject_rx:
+              id: virtual_uart_controller
+              data: !lambda return data;
+  - id: virtual_uart_controller
+    baud_rate: 9600
+    auto_start: true # See comment on virtual_uart_server above
+    debug:
+    on_tx:
+      - then:
+          - uart_mock.inject_rx:
+              id: virtual_uart_server
+              data: !lambda return data;
+
+globals:
+  - id: stored_u_word
+    type: uint16_t
+    initial_value: "11"
+  - id: stored_u_word_s
+    type: uint16_t
+    initial_value: "4660"
+  - id: stored_s_word
+    type: int16_t
+    initial_value: "-11"
+  - id: stored_s_word_s
+    type: int16_t
+    initial_value: "-2"
+  - id: stored_u_dword
+    type: uint32_t
+    initial_value: "1001"
+  - id: stored_s_dword
+    type: int32_t
+    initial_value: "-1001"
+  - id: stored_u_dword_r
+    type: uint32_t
+    initial_value: "3003"
+  - id: stored_s_dword_r
+    type: int32_t
+    initial_value: "-3003"
+  - id: stored_u_qword
+    type: uint64_t
+    initial_value: "5005"
+  - id: stored_s_qword
+    type: int64_t
+    initial_value: "-5005"
+  - id: stored_u_qword_r
+    type: uint64_t
+    initial_value: "7007"
+  - id: stored_s_qword_r
+    type: int64_t
+    initial_value: "-7007"
+  - id: stored_fp32
+    type: float
+    initial_value: "1.5"
+  - id: stored_fp32_r
+    type: float
+    initial_value: "2.5"
+
+modbus:
+  - uart_id: virtual_uart_server
+    id: virtual_modbus_server
+    role: server
+  - uart_id: virtual_uart_controller
+    id: virtual_modbus_controller
+    role: client
+    turnaround_time: 10ms
+
+modbus_controller:
+  - address: 1
+    modbus_id: virtual_modbus_controller
+    update_interval: 2s
+    id: modbus_controller_1
+
+modbus_server:
+  - address: 1
+    modbus_id: virtual_modbus_server
+    id: modbus_server_1
+    registers:
+      - address: 0x01
+        value_type: U_WORD
+        read_lambda: return id(stored_u_word);
+        write_lambda: id(stored_u_word) = x; return true;
+      - address: 0x02
+        value_type: U_WORD_S
+        read_lambda: return id(stored_u_word_s);
+        write_lambda: id(stored_u_word_s) = x; return true;
+      - address: 0x03
+        value_type: S_WORD
+        read_lambda: return id(stored_s_word);
+        write_lambda: id(stored_s_word) = x; return true;
+      - address: 0x04
+        value_type: S_WORD_S
+        read_lambda: return id(stored_s_word_s);
+        write_lambda: id(stored_s_word_s) = x; return true;
+      - address: 0x05
+        value_type: U_DWORD
+        read_lambda: return id(stored_u_dword);
+        write_lambda: id(stored_u_dword) = x; return true;
+      - address: 0x08
+        value_type: S_DWORD
+        read_lambda: return id(stored_s_dword);
+        write_lambda: id(stored_s_dword) = x; return true;
+      - address: 0x0B
+        value_type: U_DWORD_R
+        read_lambda: return id(stored_u_dword_r);
+        write_lambda: id(stored_u_dword_r) = x; return true;
+      - address: 0x0E
+        value_type: S_DWORD_R
+        read_lambda: return id(stored_s_dword_r);
+        write_lambda: id(stored_s_dword_r) = x; return true;
+      - address: 0x11
+        value_type: U_QWORD
+        read_lambda: return id(stored_u_qword);
+        write_lambda: id(stored_u_qword) = x; return true;
+      - address: 0x16
+        value_type: S_QWORD
+        read_lambda: return id(stored_s_qword);
+        write_lambda: id(stored_s_qword) = x; return true;
+      - address: 0x1B
+        value_type: U_QWORD_R
+        read_lambda: return id(stored_u_qword_r);
+        write_lambda: id(stored_u_qword_r) = x; return true;
+      - address: 0x20
+        value_type: S_QWORD_R
+        read_lambda: return id(stored_s_qword_r);
+        write_lambda: id(stored_s_qword_r) = x; return true;
+      - address: 0x25
+        value_type: FP32
+        read_lambda: return id(stored_fp32);
+        write_lambda: id(stored_fp32) = x; return true;
+      - address: 0x28
+        value_type: FP32_R
+        read_lambda: return id(stored_fp32_r);
+        write_lambda: id(stored_fp32_r) = x; return true;
+
+sensor:
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_u_word"
+    address: 0x01
+    register_type: holding
+    value_type: U_WORD
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_u_word_s"
+    address: 0x02
+    register_type: holding
+    value_type: U_WORD_S
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_s_word"
+    address: 0x03
+    register_type: holding
+    value_type: S_WORD
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_s_word_s"
+    address: 0x04
+    register_type: holding
+    value_type: S_WORD_S
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_u_dword"
+    address: 0x05
+    register_type: holding
+    value_type: U_DWORD
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_s_dword"
+    address: 0x08
+    register_type: holding
+    value_type: S_DWORD
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_u_dword_r"
+    address: 0x0B
+    register_type: holding
+    value_type: U_DWORD_R
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_s_dword_r"
+    address: 0x0E
+    register_type: holding
+    value_type: S_DWORD_R
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_u_qword"
+    address: 0x11
+    register_type: holding
+    value_type: U_QWORD
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_s_qword"
+    address: 0x16
+    register_type: holding
+    value_type: S_QWORD
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_u_qword_r"
+    address: 0x1B
+    register_type: holding
+    value_type: U_QWORD_R
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_s_qword_r"
+    address: 0x20
+    register_type: holding
+    value_type: S_QWORD_R
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_fp32"
+    address: 0x25
+    register_type: holding
+    value_type: FP32
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "reg_fp32_r"
+    address: 0x28
+    register_type: holding
+    value_type: FP32_R
+
+number:
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_u_word"
+    address: 0x01
+    register_type: holding
+    value_type: U_WORD
+    min_value: 0
+    max_value: 65535
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_u_word_s"
+    address: 0x02
+    register_type: holding
+    value_type: U_WORD_S
+    min_value: 0
+    max_value: 65535
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_s_word"
+    address: 0x03
+    register_type: holding
+    value_type: S_WORD
+    min_value: -16777215
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_s_word_s"
+    address: 0x04
+    register_type: holding
+    value_type: S_WORD_S
+    min_value: -16777215
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_u_dword"
+    address: 0x05
+    register_type: holding
+    value_type: U_DWORD
+    min_value: 0
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_s_dword"
+    address: 0x08
+    register_type: holding
+    value_type: S_DWORD
+    min_value: -16777215
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_u_dword_r"
+    address: 0x0B
+    register_type: holding
+    value_type: U_DWORD_R
+    min_value: 0
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_s_dword_r"
+    address: 0x0E
+    register_type: holding
+    value_type: S_DWORD_R
+    min_value: -16777215
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_u_qword"
+    address: 0x11
+    register_type: holding
+    value_type: U_QWORD
+    min_value: 0
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_s_qword"
+    address: 0x16
+    register_type: holding
+    value_type: S_QWORD
+    min_value: -16777215
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_u_qword_r"
+    address: 0x1B
+    register_type: holding
+    value_type: U_QWORD_R
+    min_value: 0
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_s_qword_r"
+    address: 0x20
+    register_type: holding
+    value_type: S_QWORD_R
+    min_value: -16777215
+    max_value: 16777215
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_fp32"
+    address: 0x25
+    register_type: holding
+    value_type: FP32
+    min_value: -16777215
+    max_value: 16777215
+    step: 0.01
+  - platform: modbus_controller
+    modbus_controller_id: modbus_controller_1
+    name: "write_fp32_r"
+    address: 0x28
+    register_type: holding
+    value_type: FP32_R
+    min_value: -16777215
+    max_value: 16777215
+    step: 0.01
+
+button:
+  - platform: template
+    name: "Start Scenario"
+    id: start_scenario_btn
+    # This test does not have anything to start (mock is autostart)

tests/integration/test_socket_set_sockaddr.py

@@ -0,0 +1,40 @@
+"""Integration test for the socket::set_sockaddr failure contract."""
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_socket_set_sockaddr(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """set_sockaddr reports an invalid address with 0 and accepts broadcast."""
+    loop = asyncio.get_running_loop()
+    result: asyncio.Future[tuple[int, int, int]] = loop.create_future()
+
+    def on_log_line(line: str) -> None:
+        match = re.search(
+            r"SET_SOCKADDR invalid=(\d+) valid=(\d+) broadcast=(\d+)", line
+        )
+        if match and not result.done():
+            result.set_result(tuple(int(g) for g in match.groups()))
+
+    async with (
+        run_compiled(yaml_config, line_callback=on_log_line),
+        api_client_connected() as client,
+    ):
+        assert (await client.device_info()).name == "socket-set-sockaddr"
+        try:
+            invalid, valid, broadcast = await asyncio.wait_for(result, timeout=10.0)
+        except TimeoutError:
+            pytest.fail("SET_SOCKADDR marker never appeared")
+
+    assert invalid == 0
+    assert valid > 0
+    assert broadcast == valid

tests/integration/test_uart_mock_modbus.py

@@ -19,40 +19,23 @@ from __future__ import annotations
 
 import asyncio
 from collections.abc import Callable
+from dataclasses import dataclass
 
 from aioesphomeapi import ButtonInfo, NumberInfo, SwitchInfo, TextSensorState
 import pytest
 
-from .state_utils import SensorTracker, find_entity, require_entity, wait_for_state
+from .state_utils import SensorTracker, find_entity, wait_for_state
 from .types import APIClientConnectedFactory, RunCompiledFunction
 
 
-def _swap16(value: int) -> int:
-    """Byte-swapped view of a 16-bit register as the raw U_WORD wire value."""
-    return ((value & 0xFF) << 8) | (value >> 8)
+@dataclass
+class RegisterTestCase:
+    """Test parameters for a single modbus register write/read round-trip."""
 
-
-# Raw U_WORD view of reg_u_word_s's initial 0x1234
-MESH_RAW_U_WORD_S = _swap16(4660)
-
-# Initial values of the mesh fixture's address 1 registers; the
-# server_controller test reads them and the write test uses them as baseline.
-MESH_INITIAL_VALUES: dict[str, object] = {
-    "reg_u_word": 99,
-    "reg_u_word_s": 4660,
-    "reg_s_word": -99,
-    "reg_s_word_s": -2,
-    "reg_u_dword": 16909060,
-    "reg_s_dword": -16909060,
-    "reg_u_dword_r": pytest.approx(67305985),
-    "reg_s_dword_r": pytest.approx(-67305985),
-    "reg_u_qword": pytest.approx(72623859790382856),
-    "reg_s_qword": pytest.approx(-72623859790382856),
-    "reg_u_qword_r": pytest.approx(578437695752307201),
-    "reg_s_qword_r": pytest.approx(-578437695752307201),
-    "reg_fp32": pytest.approx(3.14),
-    "reg_fp32_r": pytest.approx(2.5),
-}
+    initial_value: object
+    write_number_name: str
+    write_value: float
+    post_write_value: object
 
 
 # ---------------------------------------------------------------------------
@@ -327,7 +310,23 @@ async def test_uart_mock_modbus_server_controller(
 
     line_callback, error_log_lines, warning_log_lines = _make_modbus_line_callback()
 
-    expected_values = MESH_INITIAL_VALUES | {"reg_u_word_s_raw": MESH_RAW_U_WORD_S}
+    expected_values = {
+        "reg_u_word": 99,
+        "reg_u_word_s": 4660,
+        "reg_u_word_s_raw": 13330,
+        "reg_s_word": -99,
+        "reg_s_word_s": -2,
+        "reg_u_dword": 16909060,
+        "reg_s_dword": -16909060,
+        "reg_u_dword_r": pytest.approx(67305985),
+        "reg_s_dword_r": pytest.approx(-67305985),
+        "reg_u_qword": pytest.approx(72623859790382856),
+        "reg_s_qword": pytest.approx(-72623859790382856),
+        "reg_u_qword_r": pytest.approx(578437695752307201),
+        "reg_s_qword_r": pytest.approx(-578437695752307201),
+        "reg_fp32": pytest.approx(3.14),
+        "reg_fp32_r": pytest.approx(3.14),
+    }
     tracker = SensorTracker(list(expected_values.keys()))
     futures = tracker.expect_all(expected_values)
 
@@ -335,12 +334,14 @@ async def test_uart_mock_modbus_server_controller(
         run_compiled(yaml_config, line_callback=line_callback),
         api_client_connected() as client,
     ):
+        # The controller polls from boot, so the first values can already be in
+        # the states the device sends on connect; matching them there saves
+        # waiting for the next poll
         await tracker.setup_and_start_scenario(client, match_initial_states=True)
         await tracker.await_all(futures)
         _assert_no_modbus_errors(error_log_lines, warning_log_lines)
 
 
-@pytest.mark.shared_yaml("uart_mock_modbus_mesh")
 @pytest.mark.asyncio
 async def test_uart_mock_modbus_server_controller_write(
     yaml_config: str,
@@ -356,47 +357,51 @@ async def test_uart_mock_modbus_server_controller_write(
 
     line_callback, error_log_lines, warning_log_lines = _make_modbus_line_callback()
 
-    # Per read-back sensor: the number entity to write through and the value;
-    # floats read back within tolerance, everything else exactly
-    register_writes: dict[str, tuple[str, int | float]] = {
-        "reg_u_word": ("write_u_word", 42),
-        "reg_u_word_s": ("write_u_word_s", 17185),
-        "reg_s_word": ("write_s_word", -42),
-        "reg_s_word_s": ("write_s_word_s", -257),
-        "reg_u_dword": ("write_u_dword", 2002),
-        "reg_s_dword": ("write_s_dword", -2002),
-        "reg_u_dword_r": ("write_u_dword_r", 4004),
-        "reg_s_dword_r": ("write_s_dword_r", -4004),
-        "reg_u_qword": ("write_u_qword", 6006),
-        "reg_s_qword": ("write_s_qword", -6006),
-        "reg_u_qword_r": ("write_u_qword_r", 8008),
-        "reg_s_qword_r": ("write_s_qword_r", -8008),
-        "reg_fp32": ("write_fp32", 6.28),
-        "reg_fp32_r": ("write_fp32_r", 9.42),
+    register_test_cases: dict[str, RegisterTestCase] = {
+        "reg_u_word": RegisterTestCase(11, "write_u_word", 42, 42),
+        "reg_u_word_s": RegisterTestCase(4660, "write_u_word_s", 17185, 17185),
+        "reg_s_word": RegisterTestCase(-11, "write_s_word", -42, -42),
+        "reg_s_word_s": RegisterTestCase(-2, "write_s_word_s", -257, -257),
+        "reg_u_dword": RegisterTestCase(1001, "write_u_dword", 2002, 2002),
+        "reg_s_dword": RegisterTestCase(-1001, "write_s_dword", -2002, -2002),
+        "reg_u_dword_r": RegisterTestCase(3003, "write_u_dword_r", 4004, 4004),
+        "reg_s_dword_r": RegisterTestCase(-3003, "write_s_dword_r", -4004, -4004),
+        "reg_u_qword": RegisterTestCase(5005, "write_u_qword", 6006, 6006),
+        "reg_s_qword": RegisterTestCase(-5005, "write_s_qword", -6006, -6006),
+        "reg_u_qword_r": RegisterTestCase(7007, "write_u_qword_r", 8008, 8008),
+        "reg_s_qword_r": RegisterTestCase(-7007, "write_s_qword_r", -8008, -8008),
+        "reg_fp32": RegisterTestCase(
+            pytest.approx(1.5, abs=0.01),
+            "write_fp32",
+            3.14,
+            pytest.approx(3.14, abs=0.01),
+        ),
+        "reg_fp32_r": RegisterTestCase(
+            pytest.approx(2.5, abs=0.01),
+            "write_fp32_r",
+            6.28,
+            pytest.approx(6.28, abs=0.01),
+        ),
     }
 
-    tracker = SensorTracker([*register_writes, "reg_u_word_s_raw"])
+    tracker = SensorTracker(list(register_test_cases.keys()))
 
-    # The raw U_WORD view of 0x02 pins the byte swap on the write path: the
-    # round trip through write_u_word_s applies the swap an even number of
-    # times, so only the raw sensor can catch a symmetrically dropped swap.
     # Phase 1: expect initial baseline values
     initial_futures = tracker.expect_all(
-        MESH_INITIAL_VALUES | {"reg_u_word_s_raw": MESH_RAW_U_WORD_S}
+        {name: case.initial_value for name, case in register_test_cases.items()}
     )
     # Phase 2: expect post-write values (registered now so on_state can match them)
     written_futures = tracker.expect_all(
-        {
-            name: pytest.approx(value, abs=0.01) if isinstance(value, float) else value
-            for name, (_, value) in register_writes.items()
-        }
-        | {"reg_u_word_s_raw": _swap16(register_writes["reg_u_word_s"][1])}
+        {name: case.post_write_value for name, case in register_test_cases.items()}
     )
 
     async with (
         run_compiled(yaml_config, line_callback=line_callback),
         api_client_connected() as client,
     ):
+        # The controller polls from boot, so the baseline can already be in the
+        # states the device sends on connect; matching it there saves waiting for
+        # the next poll
         entities = await tracker.setup_and_start_scenario(
             client, match_initial_states=True
         )
@@ -405,22 +410,19 @@ async def test_uart_mock_modbus_server_controller_write(
         # connection is working before issuing writes
         await tracker.await_all(initial_futures, timeout=4.0)
 
-        # Issue write commands for all register types; exact object_id match,
-        # since several write_* names are prefixes of a sibling
-        numbers = {
-            e.object_id.lower(): e for e in entities if isinstance(e, NumberInfo)
-        }
-        for number_name, value in register_writes.values():
-            entity = numbers.get(number_name)
-            assert entity is not None, f"{number_name} number entity not found"
-            client.number_command(entity.key, value)
+        # Issue write commands for all register types
+        for case in register_test_cases.values():
+            entity = find_entity(entities, case.write_number_name, NumberInfo)
+            assert entity is not None, (
+                f"{case.write_number_name} number entity not found"
+            )
+            client.number_command(entity.key, case.write_value)
 
         # Wait for sensors to reflect the written values (round-trip write+read)
         await tracker.await_all(written_futures, timeout=4.0)
         _assert_no_modbus_errors(error_log_lines, warning_log_lines)
 
 
-@pytest.mark.shared_yaml("uart_mock_modbus_mesh")
 @pytest.mark.asyncio
 async def test_uart_mock_modbus_server_controller_bits(
     yaml_config: str,
@@ -466,6 +468,8 @@ async def test_uart_mock_modbus_server_controller_bits(
         run_compiled(yaml_config, line_callback=line_callback),
         api_client_connected() as client,
     ):
+        # The controller polls from boot and binary sensors drop repeats, so the
+        # baseline can arrive only in the states the device sends on connect
         entities = await tracker.setup_and_start_scenario(
             client, match_initial_states=True
         )
@@ -476,7 +480,8 @@ async def test_uart_mock_modbus_server_controller_bits(
 
         # Flip both writable bits: 0x02 false -> true, 0x03 true -> false
         for switch_name, value in (("write_bit_2", True), ("write_bit_3", False)):
-            entity = require_entity(entities, switch_name, SwitchInfo)
+            entity = find_entity(entities, switch_name, SwitchInfo)
+            assert entity is not None, f"{switch_name} switch entity not found"
             client.switch_command(entity.key, value)
 
         # Wait for both read views to reflect the written values
@@ -503,6 +508,9 @@ async def test_uart_mock_modbus_server_controller_multiple(
         run_compiled(yaml_config, line_callback=line_callback),
         api_client_connected() as client,
     ):
+        # The controller polls from boot, so the first values can already be in
+        # the states the device sends on connect; matching them there saves
+        # waiting for the next poll
         await tracker.setup_and_start_scenario(client, match_initial_states=True)
         await tracker.await_all(futures)
         _assert_no_modbus_errors(error_log_lines, warning_log_lines)