[socket] Zero lwip address struct and narrow dual-stack bind promotion

esphome/components/socket/bsd_sockets_impl.h

@@ -144,6 +144,9 @@ class BSDSocketImpl {
 
   int get_fd() const { return this->fd_; }
 
+  /// UDP rx drop counter parity with LWIPRawUDPImpl; drops are not counted here.
+  uint16_t get_rx_dropped() const { return 0; }
+
  protected:
   // fd_ < 0 means "not open" — used both pre-open (initial state) and post-close. This
   // replaces a separate closed_ flag: close() sets fd_ = -1 after ::close(), and the

esphome/components/socket/lwip_raw_common_impl.cpp

@@ -51,6 +51,8 @@ bool sockaddr_to_lwip(const struct sockaddr *addr, socklen_t addrlen, ip_addr_t
   // headers.h defines sockaddr and sockaddr_in with the same size, so this covers AF_INET
   if (addrlen < sizeof(struct sockaddr))
     return false;
+  // Zero the whole struct — the IPv6 zone byte would otherwise be stack garbage
+  memset(ip, 0, sizeof(*ip));
   if (addr->sa_family == AF_INET) {
     auto *addr4 = reinterpret_cast<const sockaddr_in *>(addr);
     *port = ntohs(addr4->sin_port);
@@ -77,7 +79,8 @@ bool sockaddr_to_lwip_bind(sa_family_t family, const struct sockaddr *addr, sock
   if (!sockaddr_to_lwip(addr, addrlen, ip, port))
     return false;
 #if LWIP_IPV6
-  if (family == AF_INET6)
+  // Only promote wildcard binds — a specific address must keep filtering
+  if (family == AF_INET6 && ip_addr_isany_val(*ip))
     IP_SET_TYPE_VAL(*ip, IPADDR_TYPE_ANY);
 #endif
   return true;

esphome/components/socket/lwip_raw_common_impl.h

@@ -31,10 +31,7 @@ namespace esphome::socket {
 // This is a per-TU convenience macro, not defined here to avoid macro leaking.
 
 /// Convert lwip ip_addr_t + host-order port to sockaddr, based on the socket's address family.
-/// @param port_host Port in host byte order. TCP callers must convert from network order first
-///                  (tcp_pcb stores ports in network byte order); UDP callers can pass directly
-///                  (lwip udp_recv callback provides port in host byte order).
-/// Shared by both TCP (LWIPRawCommon) and UDP (LWIPRawUDPImpl) implementations.
+/// TCP callers pass ntohs(pcb port) to preserve historical getpeername/getsockname output.
 int lwip_ip_to_sockaddr(sa_family_t family, const ip_addr_t *ip, uint16_t port_host, struct sockaddr *name,
                         socklen_t *addrlen);
 

esphome/components/socket/lwip_sockets_impl.h

@@ -84,6 +84,9 @@ class LwIPSocketImpl {
 
   int get_fd() const { return this->fd_; }
 
+  /// UDP rx drop counter parity with LWIPRawUDPImpl; drops are not counted here.
+  uint16_t get_rx_dropped() const { return 0; }
+
  protected:
   // fd_ < 0 means "not open" — used both pre-open (initial state) and post-close. This
   // replaces a separate closed_ flag: close() sets fd_ = -1 after lwip_close(), and the