From c85b1b8609f1a7d4545b2ed40c74eb8dca7afacc Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 14 Dec 2025 13:31:19 -0600
Subject: [PATCH] [web_server_idf] Always enable LRU purge to prevent socket
 exhaustion (#12481)

---
 .../captive_portal/captive_portal.cpp         |  6 ------
 .../captive_portal/captive_portal.h           |  4 ----
 .../web_server_idf/web_server_idf.cpp         | 19 +++++--------------
 .../web_server_idf/web_server_idf.h           |  2 --
 4 files changed, 5 insertions(+), 26 deletions(-)

diff --git a/esphome/components/captive_portal/captive_portal.cpp b/esphome/components/captive_portal/captive_portal.cpp
index 4eb00835b..e1f92d2d2 100644
--- a/esphome/components/captive_portal/captive_portal.cpp
+++ b/esphome/components/captive_portal/captive_portal.cpp
@@ -65,12 +65,6 @@ void CaptivePortal::start() {
   this->base_->init();
   if (!this->initialized_) {
     this->base_->add_handler(this);
-#ifdef USE_ESP32
-    // Enable LRU socket purging to handle captive portal detection probe bursts
-    // OS captive portal detection makes many simultaneous HTTP requests which can
-    // exhaust sockets. LRU purging automatically closes oldest idle connections.
-    this->base_->get_server()->set_lru_purge_enable(true);
-#endif
   }
 
   network::IPAddress ip = wifi::global_wifi_component->wifi_soft_ap_ip();
diff --git a/esphome/components/captive_portal/captive_portal.h b/esphome/components/captive_portal/captive_portal.h
index ae9b9dfba..f48c286f0 100644
--- a/esphome/components/captive_portal/captive_portal.h
+++ b/esphome/components/captive_portal/captive_portal.h
@@ -40,10 +40,6 @@ class CaptivePortal : public AsyncWebHandler, public Component {
   void end() {
     this->active_ = false;
     this->disable_loop();  // Stop processing DNS requests
-#ifdef USE_ESP32
-    // Disable LRU socket purging now that captive portal is done
-    this->base_->get_server()->set_lru_purge_enable(false);
-#endif
     this->base_->deinit();
     if (this->dns_server_ != nullptr) {
       this->dns_server_->stop();
diff --git a/esphome/components/web_server_idf/web_server_idf.cpp b/esphome/components/web_server_idf/web_server_idf.cpp
index af99b85e5..8c3ad288c 100644
--- a/esphome/components/web_server_idf/web_server_idf.cpp
+++ b/esphome/components/web_server_idf/web_server_idf.cpp
@@ -117,18 +117,6 @@ void AsyncWebServer::end() {
   }
 }
 
-void AsyncWebServer::set_lru_purge_enable(bool enable) {
-  if (this->lru_purge_enable_ == enable) {
-    return;  // No change needed
-  }
-  this->lru_purge_enable_ = enable;
-  // If server is already running, restart it with new config
-  if (this->server_) {
-    this->end();
-    this->begin();
-  }
-}
-
 void AsyncWebServer::begin() {
   if (this->server_) {
     this->end();
@@ -136,8 +124,11 @@ void AsyncWebServer::begin() {
   httpd_config_t config = HTTPD_DEFAULT_CONFIG();
   config.server_port = this->port_;
   config.uri_match_fn = [](const char * /*unused*/, const char * /*unused*/, size_t /*unused*/) { return true; };
-  // Enable LRU purging if requested (e.g., by captive portal to handle probe bursts)
-  config.lru_purge_enable = this->lru_purge_enable_;
+  // Always enable LRU purging to handle socket exhaustion gracefully.
+  // When max sockets is reached, the oldest connection is closed to make room for new ones.
+  // This prevents "httpd_accept_conn: error in accept (23)" errors.
+  // See: https://github.com/esphome/esphome/issues/12464
+  config.lru_purge_enable = true;
   // Use custom close function that shuts down before closing to prevent lwIP race conditions
   config.close_fn = AsyncWebServer::safe_close_with_shutdown;
   if (httpd_start(&this->server_, &config) == ESP_OK) {
diff --git a/esphome/components/web_server_idf/web_server_idf.h b/esphome/components/web_server_idf/web_server_idf.h
index a139e9e4d..5f9f59838 100644
--- a/esphome/components/web_server_idf/web_server_idf.h
+++ b/esphome/components/web_server_idf/web_server_idf.h
@@ -199,13 +199,11 @@ class AsyncWebServer {
     return *handler;
   }
 
-  void set_lru_purge_enable(bool enable);
   httpd_handle_t get_server() { return this->server_; }
 
  protected:
   uint16_t port_{};
   httpd_handle_t server_{};
-  bool lru_purge_enable_{false};
   static esp_err_t request_handler(httpd_req_t *r);
   static esp_err_t request_post_handler(httpd_req_t *r);
   esp_err_t request_handler_(AsyncWebServerRequest *request) const;