From 9d967b01c870716a2aaca116582604cc2295b2b3 Mon Sep 17 00:00:00 2001
From: Joakim Plate <elupus@ecce.se>
Date: Wed, 21 Jan 2026 21:32:39 +0100
Subject: [PATCH] Expose sockaddr to string formatter (#12351)

---
 esphome/components/socket/socket.cpp | 14 +++++++-------
 esphome/components/socket/socket.h   |  3 +++
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/esphome/components/socket/socket.cpp b/esphome/components/socket/socket.cpp
index bb94ecb675..fd8725b363 100644
--- a/esphome/components/socket/socket.cpp
+++ b/esphome/components/socket/socket.cpp
@@ -46,15 +46,15 @@ static inline const char *esphome_inet_ntop6(const void *addr, char *buf, size_t
 #endif
 
 // Format sockaddr into caller-provided buffer, returns length written (excluding null)
-static size_t format_sockaddr_to(const struct sockaddr_storage &storage, std::span<char, SOCKADDR_STR_LEN> buf) {
-  if (storage.ss_family == AF_INET) {
-    const auto *addr = reinterpret_cast<const struct sockaddr_in *>(&storage);
+size_t format_sockaddr_to(const struct sockaddr *addr_ptr, socklen_t len, std::span<char, SOCKADDR_STR_LEN> buf) {
+  if (addr_ptr->sa_family == AF_INET && len >= sizeof(const struct sockaddr_in)) {
+    const auto *addr = reinterpret_cast<const struct sockaddr_in *>(addr_ptr);
     if (esphome_inet_ntop4(&addr->sin_addr, buf.data(), buf.size()) != nullptr)
       return strlen(buf.data());
   }
 #if USE_NETWORK_IPV6
-  else if (storage.ss_family == AF_INET6) {
-    const auto *addr = reinterpret_cast<const struct sockaddr_in6 *>(&storage);
+  else if (addr_ptr->sa_family == AF_INET6 && len >= sizeof(sockaddr_in6)) {
+    const auto *addr = reinterpret_cast<const struct sockaddr_in6 *>(addr_ptr);
 #ifndef USE_SOCKET_IMPL_LWIP_TCP
     // Format IPv4-mapped IPv6 addresses as regular IPv4 (not supported on ESP8266 raw TCP)
     if (addr->sin6_addr.un.u32_addr[0] == 0 && addr->sin6_addr.un.u32_addr[1] == 0 &&
@@ -78,7 +78,7 @@ size_t Socket::getpeername_to(std::span<char, SOCKADDR_STR_LEN> buf) {
     buf[0] = '\0';
     return 0;
   }
-  return format_sockaddr_to(storage, buf);
+  return format_sockaddr_to(reinterpret_cast<struct sockaddr *>(&storage), len, buf);
 }
 
 size_t Socket::getsockname_to(std::span<char, SOCKADDR_STR_LEN> buf) {
@@ -88,7 +88,7 @@ size_t Socket::getsockname_to(std::span<char, SOCKADDR_STR_LEN> buf) {
     buf[0] = '\0';
     return 0;
   }
-  return format_sockaddr_to(storage, buf);
+  return format_sockaddr_to(reinterpret_cast<struct sockaddr *>(&storage), len, buf);
 }
 
 std::unique_ptr<Socket> socket_ip(int type, int protocol) {
diff --git a/esphome/components/socket/socket.h b/esphome/components/socket/socket.h
index d74804fdb0..e8b0948acd 100644
--- a/esphome/components/socket/socket.h
+++ b/esphome/components/socket/socket.h
@@ -102,6 +102,9 @@ 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);
 
+/// 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);
+
 #if defined(USE_ESP8266) && defined(USE_SOCKET_IMPL_LWIP_TCP)
 /// Delay that can be woken early by socket activity.
 /// On ESP8266, lwip callbacks set a flag and call esp_schedule() to wake the delay.