[socket] Devirtualize Socket::ready() and implement working ready() for LWIP raw TCP (#13913)

Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

esphome/components/api/api_connection.cpp

@@ -1921,10 +1921,6 @@ bool APIConnection::schedule_batch_() {
 }
 
 void APIConnection::process_batch_() {
-  // Ensure MessageInfo remains trivially destructible for our placement new approach
-  static_assert(std::is_trivially_destructible<MessageInfo>::value,
-                "MessageInfo must remain trivially destructible with this placement-new approach");
-
   if (this->deferred_batch_.empty()) {
     this->flags_.batch_scheduled = false;
     return;
@@ -1949,6 +1945,10 @@ void APIConnection::process_batch_() {
   for (size_t i = 0; i < num_items; i++) {
     total_estimated_size += this->deferred_batch_[i].estimated_size;
   }
+  // Clamp to MAX_BATCH_PACKET_SIZE — we won't send more than that per batch
+  if (total_estimated_size > MAX_BATCH_PACKET_SIZE) {
+    total_estimated_size = MAX_BATCH_PACKET_SIZE;
+  }
 
   this->prepare_first_message_buffer(shared_buf, header_padding, total_estimated_size);
 
@@ -1972,7 +1972,20 @@ void APIConnection::process_batch_() {
     return;
   }
 
-  size_t messages_to_process = std::min(num_items, MAX_MESSAGES_PER_BATCH);
+  // Multi-message path — heavy stack frame isolated in separate noinline function
+  this->process_batch_multi_(shared_buf, num_items, header_padding, footer_size);
+}
+
+// Separated from process_batch_() so the single-message fast path gets a minimal
+// stack frame without the MAX_MESSAGES_PER_BATCH * sizeof(MessageInfo) array.
+void APIConnection::process_batch_multi_(std::vector<uint8_t> &shared_buf, size_t num_items, uint8_t header_padding,
+                                         uint8_t footer_size) {
+  // Ensure MessageInfo remains trivially destructible for our placement new approach
+  static_assert(std::is_trivially_destructible<MessageInfo>::value,
+                "MessageInfo must remain trivially destructible with this placement-new approach");
+
+  const size_t messages_to_process = std::min(num_items, MAX_MESSAGES_PER_BATCH);
+  const uint8_t frame_overhead = header_padding + footer_size;
 
   // Stack-allocated array for message info
   alignas(MessageInfo) char message_info_storage[MAX_MESSAGES_PER_BATCH * sizeof(MessageInfo)];
@@ -1999,7 +2012,7 @@ void APIConnection::process_batch_() {
 
     // Message was encoded successfully
     // payload_size is header_padding + actual payload size + footer_size
-    uint16_t proto_payload_size = payload_size - header_padding - footer_size;
+    uint16_t proto_payload_size = payload_size - frame_overhead;
     // Use placement new to construct MessageInfo in pre-allocated stack array
     // This avoids default-constructing all MAX_MESSAGES_PER_BATCH elements
     // Explicit destruction is not needed because MessageInfo is trivially destructible,
@@ -2015,42 +2028,38 @@ void APIConnection::process_batch_() {
     current_offset = shared_buf.size() + footer_size;
   }
 
-  if (items_processed == 0) {
-    this->deferred_batch_.clear();
-    return;
-  }
+  if (items_processed > 0) {
+    // Add footer space for the last message (for Noise protocol MAC)
+    if (footer_size > 0) {
+      shared_buf.resize(shared_buf.size() + footer_size);
+    }
 
-  // Add footer space for the last message (for Noise protocol MAC)
-  if (footer_size > 0) {
-    shared_buf.resize(shared_buf.size() + footer_size);
-  }
-
-  // Send all collected messages
-  APIError err = this->helper_->write_protobuf_messages(ProtoWriteBuffer{&shared_buf},
-                                                        std::span<const MessageInfo>(message_info, items_processed));
-  if (err != APIError::OK && err != APIError::WOULD_BLOCK) {
-    this->fatal_error_with_log_(LOG_STR("Batch write failed"), err);
-  }
+    // Send all collected messages
+    APIError err = this->helper_->write_protobuf_messages(ProtoWriteBuffer{&shared_buf},
+                                                          std::span<const MessageInfo>(message_info, items_processed));
+    if (err != APIError::OK && err != APIError::WOULD_BLOCK) {
+      this->fatal_error_with_log_(LOG_STR("Batch write failed"), err);
+    }
 
 #ifdef HAS_PROTO_MESSAGE_DUMP
-  // Log messages after send attempt for VV debugging
-  // It's safe to use the buffer for logging at this point regardless of send result
-  for (size_t i = 0; i < items_processed; i++) {
-    const auto &item = this->deferred_batch_[i];
-    this->log_batch_item_(item);
-  }
+    // Log messages after send attempt for VV debugging
+    // It's safe to use the buffer for logging at this point regardless of send result
+    for (size_t i = 0; i < items_processed; i++) {
+      const auto &item = this->deferred_batch_[i];
+      this->log_batch_item_(item);
+    }
 #endif
 
-  // Handle remaining items more efficiently
-  if (items_processed < this->deferred_batch_.size()) {
-    // Remove processed items from the beginning
-    this->deferred_batch_.remove_front(items_processed);
-    // Reschedule for remaining items
-    this->schedule_batch_();
-  } else {
-    // All items processed
-    this->clear_batch_();
+    // Partial batch — remove processed items and reschedule
+    if (items_processed < this->deferred_batch_.size()) {
+      this->deferred_batch_.remove_front(items_processed);
+      this->schedule_batch_();
+      return;
+    }
   }
+
+  // All items processed (or none could be processed)
+  this->clear_batch_();
 }
 
 // Dispatch message encoding based on message_type

esphome/components/api/api_connection.h

@@ -548,8 +548,8 @@ class APIConnection final : public APIServerConnectionBase {
       batch_start_time = 0;
     }
 
-    // Remove processed items from the front
-    void remove_front(size_t count) { items.erase(items.begin(), items.begin() + count); }
+    // Remove processed items from the front — noinline to keep memmove out of warm callers
+    void remove_front(size_t count) __attribute__((noinline)) { items.erase(items.begin(), items.begin() + count); }
 
     bool empty() const { return items.empty(); }
     size_t size() const { return items.size(); }
@@ -621,6 +621,8 @@ class APIConnection final : public APIServerConnectionBase {
 
   bool schedule_batch_();
   void process_batch_();
+  void process_batch_multi_(std::vector<uint8_t> &shared_buf, size_t num_items, uint8_t header_padding,
+                            uint8_t footer_size) __attribute__((noinline));
   void clear_batch_() {
     this->deferred_batch_.clear();
     this->flags_.batch_scheduled = false;

esphome/components/cover/__init__.py

@@ -11,6 +11,7 @@ from esphome.const import (
     CONF_ICON,
     CONF_ID,
     CONF_MQTT_ID,
+    CONF_MQTT_JSON_STATE_PAYLOAD,
     CONF_ON_IDLE,
     CONF_ON_OPEN,
     CONF_POSITION,
@@ -119,6 +120,9 @@ _COVER_SCHEMA = (
     .extend(
         {
             cv.OnlyWith(CONF_MQTT_ID, "mqtt"): cv.declare_id(mqtt.MQTTCoverComponent),
+            cv.Optional(CONF_MQTT_JSON_STATE_PAYLOAD): cv.All(
+                cv.requires_component("mqtt"), cv.boolean
+            ),
             cv.Optional(CONF_DEVICE_CLASS): cv.one_of(*DEVICE_CLASSES, lower=True),
             cv.Optional(CONF_POSITION_COMMAND_TOPIC): cv.All(
                 cv.requires_component("mqtt"), cv.subscribe_topic
@@ -148,6 +152,22 @@ _COVER_SCHEMA = (
 _COVER_SCHEMA.add_extra(entity_duplicate_validator("cover"))
 
 
+def _validate_mqtt_state_topics(config):
+    if config.get(CONF_MQTT_JSON_STATE_PAYLOAD):
+        if CONF_POSITION_STATE_TOPIC in config:
+            raise cv.Invalid(
+                f"'{CONF_POSITION_STATE_TOPIC}' cannot be used with '{CONF_MQTT_JSON_STATE_PAYLOAD}: true'"
+            )
+        if CONF_TILT_STATE_TOPIC in config:
+            raise cv.Invalid(
+                f"'{CONF_TILT_STATE_TOPIC}' cannot be used with '{CONF_MQTT_JSON_STATE_PAYLOAD}: true'"
+            )
+    return config
+
+
+_COVER_SCHEMA.add_extra(_validate_mqtt_state_topics)
+
+
 def cover_schema(
     class_: MockObjClass,
     *,
@@ -195,6 +215,9 @@ async def setup_cover_core_(var, config):
             position_command_topic := config.get(CONF_POSITION_COMMAND_TOPIC)
         ) is not None:
             cg.add(mqtt_.set_custom_position_command_topic(position_command_topic))
+        if config.get(CONF_MQTT_JSON_STATE_PAYLOAD):
+            cg.add_define("USE_MQTT_COVER_JSON")
+            cg.add(mqtt_.set_use_json_format(True))
         if (tilt_state_topic := config.get(CONF_TILT_STATE_TOPIC)) is not None:
             cg.add(mqtt_.set_custom_tilt_state_topic(tilt_state_topic))
         if (tilt_command_topic := config.get(CONF_TILT_COMMAND_TOPIC)) is not None:

esphome/components/esp32/preferences.cpp

@@ -124,14 +124,11 @@ class ESP32Preferences : public ESPPreferences {
       return true;
 
     ESP_LOGV(TAG, "Saving %zu items...", s_pending_save.size());
-    // goal try write all pending saves even if one fails
     int cached = 0, written = 0, failed = 0;
     esp_err_t last_err = ESP_OK;
     uint32_t last_key = 0;
 
-    // go through vector from back to front (makes erase easier/more efficient)
-    for (ssize_t i = s_pending_save.size() - 1; i >= 0; i--) {
-      const auto &save = s_pending_save[i];
+    for (const auto &save : s_pending_save) {
       char key_str[KEY_BUFFER_SIZE];
       snprintf(key_str, sizeof(key_str), "%" PRIu32, save.key);
       ESP_LOGVV(TAG, "Checking if NVS data %s has changed", key_str);
@@ -150,8 +147,9 @@ class ESP32Preferences : public ESPPreferences {
         ESP_LOGV(TAG, "NVS data not changed skipping %" PRIu32 "  len=%zu", save.key, save.len);
         cached++;
       }
-      s_pending_save.erase(s_pending_save.begin() + i);
     }
+    s_pending_save.clear();
+
     ESP_LOGD(TAG, "Writing %d items: %d cached, %d written, %d failed", cached + written + failed, cached, written,
              failed);
     if (failed > 0) {

esphome/components/libretiny/preferences.cpp

@@ -114,14 +114,11 @@ class LibreTinyPreferences : public ESPPreferences {
       return true;
 
     ESP_LOGV(TAG, "Saving %zu items...", s_pending_save.size());
-    // goal try write all pending saves even if one fails
     int cached = 0, written = 0, failed = 0;
     fdb_err_t last_err = FDB_NO_ERR;
     uint32_t last_key = 0;
 
-    // go through vector from back to front (makes erase easier/more efficient)
-    for (ssize_t i = s_pending_save.size() - 1; i >= 0; i--) {
-      const auto &save = s_pending_save[i];
+    for (const auto &save : s_pending_save) {
       char key_str[KEY_BUFFER_SIZE];
       snprintf(key_str, sizeof(key_str), "%" PRIu32, save.key);
       ESP_LOGVV(TAG, "Checking if FDB data %s has changed", key_str);
@@ -141,8 +138,9 @@ class LibreTinyPreferences : public ESPPreferences {
         ESP_LOGD(TAG, "FDB data not changed; skipping %" PRIu32 "  len=%zu", save.key, save.len);
         cached++;
       }
-      s_pending_save.erase(s_pending_save.begin() + i);
     }
+    s_pending_save.clear();
+
     ESP_LOGD(TAG, "Writing %d items: %d cached, %d written, %d failed", cached + written + failed, cached, written,
              failed);
     if (failed > 0) {

esphome/components/mqtt/mqtt_cover.cpp

@@ -67,17 +67,26 @@ void MQTTCoverComponent::dump_config() {
   auto traits = this->cover_->get_traits();
   bool has_command_topic = traits.get_supports_position() || !traits.get_supports_tilt();
   LOG_MQTT_COMPONENT(true, has_command_topic);
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+#ifdef USE_MQTT_COVER_JSON
+  if (this->use_json_format_) {
+    ESP_LOGCONFIG(TAG, "  JSON State Payload: YES");
+  } else {
+#endif
+    if (traits.get_supports_position()) {
+      ESP_LOGCONFIG(TAG, "  Position State Topic: '%s'", this->get_position_state_topic_to(topic_buf).c_str());
+    }
+    if (traits.get_supports_tilt()) {
+      ESP_LOGCONFIG(TAG, "  Tilt State Topic: '%s'", this->get_tilt_state_topic_to(topic_buf).c_str());
+    }
+#ifdef USE_MQTT_COVER_JSON
+  }
+#endif
   if (traits.get_supports_position()) {
-    ESP_LOGCONFIG(TAG,
-                  "  Position State Topic: '%s'\n"
-                  "  Position Command Topic: '%s'",
-                  this->get_position_state_topic().c_str(), this->get_position_command_topic().c_str());
+    ESP_LOGCONFIG(TAG, "  Position Command Topic: '%s'", this->get_position_command_topic_to(topic_buf).c_str());
   }
   if (traits.get_supports_tilt()) {
-    ESP_LOGCONFIG(TAG,
-                  "  Tilt State Topic: '%s'\n"
-                  "  Tilt Command Topic: '%s'",
-                  this->get_tilt_state_topic().c_str(), this->get_tilt_command_topic().c_str());
+    ESP_LOGCONFIG(TAG, "  Tilt Command Topic: '%s'", this->get_tilt_command_topic_to(topic_buf).c_str());
   }
 }
 void MQTTCoverComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
@@ -92,13 +101,33 @@ void MQTTCoverComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConf
   if (traits.get_is_assumed_state()) {
     root[MQTT_OPTIMISTIC] = true;
   }
-  if (traits.get_supports_position()) {
-    root[MQTT_POSITION_TOPIC] = this->get_position_state_topic();
-    root[MQTT_SET_POSITION_TOPIC] = this->get_position_command_topic();
-  }
-  if (traits.get_supports_tilt()) {
-    root[MQTT_TILT_STATUS_TOPIC] = this->get_tilt_state_topic();
-    root[MQTT_TILT_COMMAND_TOPIC] = this->get_tilt_command_topic();
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+#ifdef USE_MQTT_COVER_JSON
+  if (this->use_json_format_) {
+    // JSON mode: all state published to state_topic as JSON, use templates to extract
+    root[MQTT_VALUE_TEMPLATE] = ESPHOME_F("{{ value_json.state }}");
+    if (traits.get_supports_position()) {
+      root[MQTT_POSITION_TOPIC] = this->get_state_topic_to_(topic_buf);
+      root[MQTT_POSITION_TEMPLATE] = ESPHOME_F("{{ value_json.position }}");
+      root[MQTT_SET_POSITION_TOPIC] = this->get_position_command_topic_to(topic_buf);
+    }
+    if (traits.get_supports_tilt()) {
+      root[MQTT_TILT_STATUS_TOPIC] = this->get_state_topic_to_(topic_buf);
+      root[MQTT_TILT_STATUS_TEMPLATE] = ESPHOME_F("{{ value_json.tilt }}");
+      root[MQTT_TILT_COMMAND_TOPIC] = this->get_tilt_command_topic_to(topic_buf);
+    }
+  } else
+#endif
+  {
+    // Standard mode: separate topics for position and tilt
+    if (traits.get_supports_position()) {
+      root[MQTT_POSITION_TOPIC] = this->get_position_state_topic_to(topic_buf);
+      root[MQTT_SET_POSITION_TOPIC] = this->get_position_command_topic_to(topic_buf);
+    }
+    if (traits.get_supports_tilt()) {
+      root[MQTT_TILT_STATUS_TOPIC] = this->get_tilt_state_topic_to(topic_buf);
+      root[MQTT_TILT_COMMAND_TOPIC] = this->get_tilt_command_topic_to(topic_buf);
+    }
   }
   if (traits.get_supports_tilt() && !traits.get_supports_position()) {
     config.command_topic = false;
@@ -111,8 +140,24 @@ const EntityBase *MQTTCoverComponent::get_entity() const { return this->cover_;
 bool MQTTCoverComponent::send_initial_state() { return this->publish_state(); }
 bool MQTTCoverComponent::publish_state() {
   auto traits = this->cover_->get_traits();
-  bool success = true;
   char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+#ifdef USE_MQTT_COVER_JSON
+  if (this->use_json_format_) {
+    return this->publish_json(this->get_state_topic_to_(topic_buf), [this, traits](JsonObject root) {
+      // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+      root[ESPHOME_F("state")] = cover_state_to_mqtt_str(this->cover_->current_operation, this->cover_->position,
+                                                         traits.get_supports_position());
+      if (traits.get_supports_position()) {
+        root[ESPHOME_F("position")] = static_cast<int>(roundf(this->cover_->position * 100));
+      }
+      if (traits.get_supports_tilt()) {
+        root[ESPHOME_F("tilt")] = static_cast<int>(roundf(this->cover_->tilt * 100));
+      }
+      // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
+    });
+  }
+#endif
+  bool success = true;
   if (traits.get_supports_position()) {
     char pos[VALUE_ACCURACY_MAX_LEN];
     size_t len = value_accuracy_to_buf(pos, roundf(this->cover_->position * 100), 0);

esphome/components/mqtt/mqtt_cover.h

@@ -27,12 +27,18 @@ class MQTTCoverComponent : public mqtt::MQTTComponent {
   bool publish_state();
 
   void dump_config() override;
+#ifdef USE_MQTT_COVER_JSON
+  void set_use_json_format(bool use_json_format) { this->use_json_format_ = use_json_format; }
+#endif
 
  protected:
   const char *component_type() const override;
   const EntityBase *get_entity() const override;
 
   cover::Cover *cover_;
+#ifdef USE_MQTT_COVER_JSON
+  bool use_json_format_{false};
+#endif
 };
 
 }  // namespace esphome::mqtt

esphome/components/openthread/openthread_esp.cpp

@@ -104,7 +104,7 @@ void OpenThreadComponent::ot_main() {
   esp_cli_custom_command_init();
 #endif  // CONFIG_OPENTHREAD_CLI_ESP_EXTENSION
 
-  otLinkModeConfig link_mode_config = {0};
+  otLinkModeConfig link_mode_config{};
 #if CONFIG_OPENTHREAD_FTD
   link_mode_config.mRxOnWhenIdle = true;
   link_mode_config.mDeviceType = true;

esphome/components/socket/bsd_sockets_impl.cpp

@@ -16,19 +16,13 @@ namespace esphome::socket {
 
 class BSDSocketImpl final : public Socket {
  public:
-  BSDSocketImpl(int fd, bool monitor_loop = false) : fd_(fd) {
-#ifdef USE_SOCKET_SELECT_SUPPORT
+  BSDSocketImpl(int fd, bool monitor_loop = false) {
+    this->fd_ = fd;
     // Register new socket with the application for select() if monitoring requested
     if (monitor_loop && this->fd_ >= 0) {
       // Only set loop_monitored_ to true if registration succeeds
       this->loop_monitored_ = App.register_socket_fd(this->fd_);
-    } else {
-      this->loop_monitored_ = false;
     }
-#else
-    // Without select support, ignore monitor_loop parameter
-    (void) monitor_loop;
-#endif
   }
   ~BSDSocketImpl() override {
     if (!this->closed_) {
@@ -52,12 +46,10 @@ class BSDSocketImpl final : public Socket {
   int bind(const struct sockaddr *addr, socklen_t addrlen) override { return ::bind(this->fd_, addr, addrlen); }
   int close() override {
     if (!this->closed_) {
-#ifdef USE_SOCKET_SELECT_SUPPORT
       // Unregister from select() before closing if monitored
       if (this->loop_monitored_) {
         App.unregister_socket_fd(this->fd_);
       }
-#endif
       int ret = ::close(this->fd_);
       this->closed_ = true;
       return ret;
@@ -130,23 +122,6 @@ class BSDSocketImpl final : public Socket {
     ::fcntl(this->fd_, F_SETFL, fl);
     return 0;
   }
-
-  int get_fd() const override { return this->fd_; }
-
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  bool ready() const override {
-    if (!this->loop_monitored_)
-      return true;
-    return App.is_socket_ready(this->fd_);
-  }
-#endif
-
- protected:
-  int fd_;
-  bool closed_{false};
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  bool loop_monitored_{false};
-#endif
 };
 
 // Helper to create a socket with optional monitoring

esphome/components/socket/lwip_raw_tcp_impl.cpp

@@ -452,6 +452,8 @@ class LWIPRawImpl : public Socket {
     errno = ENOSYS;
     return -1;
   }
+  bool ready() const override { return this->rx_buf_ != nullptr || this->rx_closed_ || this->pcb_ == nullptr; }
+
   int setblocking(bool blocking) final {
     if (pcb_ == nullptr) {
       errno = ECONNRESET;
@@ -576,6 +578,8 @@ class LWIPRawListenImpl final : public LWIPRawImpl {
     tcp_err(pcb_, LWIPRawImpl::s_err_fn);  // Use base class error handler
   }
 
+  bool ready() const override { return this->accepted_socket_count_ > 0; }
+
   std::unique_ptr<Socket> accept(struct sockaddr *addr, socklen_t *addrlen) override {
     if (pcb_ == nullptr) {
       errno = EBADF;

esphome/components/socket/lwip_sockets_impl.cpp

@@ -11,19 +11,13 @@ namespace esphome::socket {
 
 class LwIPSocketImpl final : public Socket {
  public:
-  LwIPSocketImpl(int fd, bool monitor_loop = false) : fd_(fd) {
-#ifdef USE_SOCKET_SELECT_SUPPORT
+  LwIPSocketImpl(int fd, bool monitor_loop = false) {
+    this->fd_ = fd;
     // Register new socket with the application for select() if monitoring requested
     if (monitor_loop && this->fd_ >= 0) {
       // Only set loop_monitored_ to true if registration succeeds
       this->loop_monitored_ = App.register_socket_fd(this->fd_);
-    } else {
-      this->loop_monitored_ = false;
     }
-#else
-    // Without select support, ignore monitor_loop parameter
-    (void) monitor_loop;
-#endif
   }
   ~LwIPSocketImpl() override {
     if (!this->closed_) {
@@ -49,12 +43,10 @@ class LwIPSocketImpl final : public Socket {
   int bind(const struct sockaddr *addr, socklen_t addrlen) override { return lwip_bind(this->fd_, addr, addrlen); }
   int close() override {
     if (!this->closed_) {
-#ifdef USE_SOCKET_SELECT_SUPPORT
       // Unregister from select() before closing if monitored
       if (this->loop_monitored_) {
         App.unregister_socket_fd(this->fd_);
       }
-#endif
       int ret = lwip_close(this->fd_);
       this->closed_ = true;
       return ret;
@@ -97,23 +89,6 @@ class LwIPSocketImpl final : public Socket {
     lwip_fcntl(this->fd_, F_SETFL, fl);
     return 0;
   }
-
-  int get_fd() const override { return this->fd_; }
-
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  bool ready() const override {
-    if (!this->loop_monitored_)
-      return true;
-    return App.is_socket_ready(this->fd_);
-  }
-#endif
-
- protected:
-  int fd_;
-  bool closed_{false};
-#ifdef USE_SOCKET_SELECT_SUPPORT
-  bool loop_monitored_{false};
-#endif
 };
 
 // Helper to create a socket with optional monitoring

esphome/components/socket/socket.cpp

@@ -10,6 +10,10 @@ namespace esphome::socket {
 
 Socket::~Socket() {}
 
+#ifdef USE_SOCKET_SELECT_SUPPORT
+bool Socket::ready() const { return !this->loop_monitored_ || App.is_socket_ready_(this->fd_); }
+#endif
+
 // Platform-specific inet_ntop wrappers
 #if defined(USE_SOCKET_IMPL_LWIP_TCP)
 // LWIP raw TCP (ESP8266) uses inet_ntoa_r which takes struct by value

esphome/components/socket/socket.h

@@ -63,13 +63,29 @@ class Socket {
   virtual int setblocking(bool blocking) = 0;
   virtual int loop() { return 0; };
 
-  /// Get the underlying file descriptor (returns -1 if not supported)
-  virtual int get_fd() const { return -1; }
+    /// Get the underlying file descriptor (returns -1 if not supported)
+    /// Non-virtual: only one socket implementation is active per build.
+#ifdef USE_SOCKET_SELECT_SUPPORT
+  int get_fd() const { return this->fd_; }
+#else
+  int get_fd() const { return -1; }
+#endif
 
   /// Check if socket has data ready to read
-  /// For loop-monitored sockets, checks with the Application's select() results
-  /// For non-monitored sockets, always returns true (assumes data may be available)
+  /// For select()-based sockets: non-virtual, checks Application's select() results
+  /// For LWIP raw TCP sockets: virtual, checks internal buffer state
+#ifdef USE_SOCKET_SELECT_SUPPORT
+  bool ready() const;
+#else
   virtual bool ready() const { return true; }
+#endif
+
+ protected:
+#ifdef USE_SOCKET_SELECT_SUPPORT
+  int fd_{-1};
+  bool closed_{false};
+  bool loop_monitored_{false};
+#endif
 };
 
 /// Create a socket of the given domain, type and protocol.

esphome/components/web_server_idf/web_server_idf.cpp

@@ -352,7 +352,26 @@ bool AsyncWebServerRequest::authenticate(const char *username, const char *passw
   esp_crypto_base64_encode(reinterpret_cast<uint8_t *>(digest), max_digest_len, &out,
                            reinterpret_cast<const uint8_t *>(user_info), user_info_len);
 
-  return strcmp(digest, auth_str + auth_prefix_len) == 0;
+  // Constant-time comparison to avoid timing side channels.
+  // No early return on length mismatch — the length difference is folded
+  // into the accumulator so any mismatch is rejected.
+  const char *provided = auth_str + auth_prefix_len;
+  size_t digest_len = out;  // length from esp_crypto_base64_encode
+  // Derive provided_len from the already-sized std::string rather than
+  // rescanning with strlen (avoids attacker-controlled scan length).
+  size_t provided_len = auth.value().size() - auth_prefix_len;
+  // Use full-width XOR so any bit difference in the lengths is preserved
+  // (uint8_t truncation would miss differences in higher bytes, e.g.
+  // digest_len vs digest_len + 256).
+  volatile size_t result = digest_len ^ provided_len;
+  // Iterate over the expected digest length only — the full-width length
+  // XOR above already rejects any length mismatch, and bounding the loop
+  // prevents a long Authorization header from forcing extra work.
+  for (size_t i = 0; i < digest_len; i++) {
+    char provided_ch = (i < provided_len) ? provided[i] : 0;
+    result |= static_cast<uint8_t>(digest[i] ^ provided_ch);
+  }
+  return result == 0;
 }
 
 void AsyncWebServerRequest::requestAuthentication(const char *realm) const {

esphome/const.py

@@ -639,6 +639,7 @@ CONF_MOVEMENT_COUNTER = "movement_counter"
 CONF_MOVING_DISTANCE = "moving_distance"
 CONF_MQTT = "mqtt"
 CONF_MQTT_ID = "mqtt_id"
+CONF_MQTT_JSON_STATE_PAYLOAD = "mqtt_json_state_payload"
 CONF_MULTIPLE = "multiple"
 CONF_MULTIPLEXER = "multiplexer"
 CONF_MULTIPLY = "multiply"

esphome/core/application.cpp

@@ -609,15 +609,6 @@ void Application::unregister_socket_fd(int fd) {
   }
 }
 
-bool Application::is_socket_ready(int fd) const {
-  // This function is thread-safe for reading the result of select()
-  // However, it should only be called after select() has been executed in the main loop
-  // The read_fds_ is only modified by select() in the main loop
-  if (fd < 0 || fd >= FD_SETSIZE)
-    return false;
-
-  return FD_ISSET(fd, &this->read_fds_);
-}
 #endif
 
 void Application::yield_with_select_(uint32_t delay_ms) {

esphome/core/application.h

@@ -101,6 +101,10 @@
 #include "esphome/components/update/update_entity.h"
 #endif
 
+namespace esphome::socket {
+class Socket;
+}  // namespace esphome::socket
+
 namespace esphome {
 
 // Teardown timeout constant (in milliseconds)
@@ -491,7 +495,8 @@ class Application {
   void unregister_socket_fd(int fd);
   /// Check if there's data available on a socket without blocking
   /// This function is thread-safe for reading, but should be called after select() has run
-  bool is_socket_ready(int fd) const;
+  /// The read_fds_ is only modified by select() in the main loop
+  bool is_socket_ready(int fd) const { return fd >= 0 && this->is_socket_ready_(fd); }
 
 #ifdef USE_WAKE_LOOP_THREADSAFE
   /// Wake the main event loop from a FreeRTOS task
@@ -503,6 +508,15 @@ class Application {
 
  protected:
   friend Component;
+  friend class socket::Socket;
+
+#ifdef USE_SOCKET_SELECT_SUPPORT
+  /// Fast path for Socket::ready() via friendship - skips negative fd check.
+  /// Safe because: fd was validated in register_socket_fd() at registration time,
+  /// and Socket::ready() only calls this when loop_monitored_ is true (registration succeeded).
+  /// FD_ISSET may include its own upper bounds check depending on platform.
+  bool is_socket_ready_(int fd) const { return FD_ISSET(fd, &this->read_fds_); }
+#endif
 
   void register_component_(Component *comp);
 

esphome/core/defines.h

@@ -145,6 +145,7 @@
 #define USE_MD5
 #define USE_SHA256
 #define USE_MQTT
+#define USE_MQTT_COVER_JSON
 #define USE_NETWORK
 #define USE_ONLINE_IMAGE_BMP_SUPPORT
 #define USE_ONLINE_IMAGE_PNG_SUPPORT

tests/components/mqtt/common.yaml

@@ -219,6 +219,7 @@ cover:
     name: Template Cover
     state_topic: some/topic/cover
     qos: 2
+    mqtt_json_state_payload: true
     lambda: |-
       if (id(some_binary_sensor).state) {
         return COVER_OPEN;
@@ -231,6 +232,53 @@ cover:
     stop_action:
       - logger.log: stop_action
     optimistic: true
+  - platform: template
+    name: Template Cover with Position and Tilt
+    state_topic: some/topic/cover_pt
+    position_state_topic: some/topic/cover_pt/position
+    position_command_topic: some/topic/cover_pt/position/set
+    tilt_state_topic: some/topic/cover_pt/tilt
+    tilt_command_topic: some/topic/cover_pt/tilt/set
+    qos: 2
+    has_position: true
+    lambda: |-
+      if (id(some_binary_sensor).state) {
+        return COVER_OPEN;
+      }
+      return COVER_CLOSED;
+    position_action:
+      - logger.log: position_action
+    tilt_action:
+      - logger.log: tilt_action
+    open_action:
+      - logger.log: open_action
+    close_action:
+      - logger.log: close_action
+    stop_action:
+      - logger.log: stop_action
+    optimistic: true
+  - platform: template
+    name: Template Cover with Position and Tilt JSON
+    state_topic: some/topic/cover_pt_json
+    qos: 2
+    mqtt_json_state_payload: true
+    has_position: true
+    lambda: |-
+      if (id(some_binary_sensor).state) {
+        return COVER_OPEN;
+      }
+      return COVER_CLOSED;
+    position_action:
+      - logger.log: position_action
+    tilt_action:
+      - logger.log: tilt_action
+    open_action:
+      - logger.log: open_action
+    close_action:
+      - logger.log: close_action
+    stop_action:
+      - logger.log: stop_action
+    optimistic: true
 
 datetime:
   - platform: template