[esp8266][api] Store error strings in PROGMEM to reduce RAM usage

esphome/components/api/api_connection.cpp

@@ -112,7 +112,7 @@ void APIConnection::start() {
   APIError err = this->helper_->init();
   if (err != APIError::OK) {
     on_fatal_error();
-    this->log_warning_("Helper init failed", err);
+    this->log_warning_(LOG_STR("Helper init failed"), err);
     return;
   }
   this->client_info_.peername = helper_->getpeername();
@@ -159,7 +159,7 @@ void APIConnection::loop() {
         break;
       } else if (err != APIError::OK) {
         on_fatal_error();
-        this->log_warning_("Reading failed", err);
+        this->log_warning_(LOG_STR("Reading failed"), err);
         return;
       } else {
         this->last_traffic_ = now;
@@ -1565,7 +1565,7 @@ bool APIConnection::send_buffer(ProtoWriteBuffer buffer, uint8_t message_type) {
     return false;
   if (err != APIError::OK) {
     on_fatal_error();
-    this->log_warning_("Packet write failed", err);
+    this->log_warning_(LOG_STR("Packet write failed"), err);
     return false;
   }
   // Do not set last_traffic_ on send
@@ -1752,7 +1752,7 @@ void APIConnection::process_batch_() {
                                                        std::span<const PacketInfo>(packet_info, packet_count));
   if (err != APIError::OK && err != APIError::WOULD_BLOCK) {
     on_fatal_error();
-    this->log_warning_("Batch write failed", err);
+    this->log_warning_(LOG_STR("Batch write failed"), err);
   }
 
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -1830,11 +1830,14 @@ void APIConnection::process_state_subscriptions_() {
 }
 #endif  // USE_API_HOMEASSISTANT_STATES
 
-void APIConnection::log_warning_(const char *message, APIError err) {
+void APIConnection::log_warning_(const LogString *message, APIError err) {
-  ESP_LOGW(TAG, "%s: %s %s errno=%d", this->get_client_combined_info().c_str(), message, api_error_to_str(err), errno);
+  ESP_LOGW(TAG, "%s: %s %s errno=%d", this->get_client_combined_info().c_str(), LOG_STR_ARG(message),
+           LOG_STR_ARG(api_error_to_logstr(err)), errno);
 }
 
-void APIConnection::log_socket_operation_failed_(APIError err) { this->log_warning_("Socket operation failed", err); }
+void APIConnection::log_socket_operation_failed_(APIError err) {
+  this->log_warning_(LOG_STR("Socket operation failed"), err);
+}
 
 }  // namespace esphome::api
 #endif

esphome/components/api/api_connection.h

@@ -732,7 +732,7 @@ class APIConnection final : public APIServerConnection {
   }
 
   // Helper function to log API errors with errno
-  void log_warning_(const char *message, APIError err);
+  void log_warning_(const LogString *message, APIError err);
   // Specific helper for duplicated error message
   void log_socket_operation_failed_(APIError err);
 };

esphome/components/api/api_frame_helper.cpp

@@ -23,59 +23,59 @@ static const char *const TAG = "api.frame_helper";
 #define LOG_PACKET_SENDING(data, len) ((void) 0)
 #endif
 
-const char *api_error_to_str(APIError err) {
+const LogString *api_error_to_logstr(APIError err) {
   // not using switch to ensure compiler doesn't try to build a big table out of it
   if (err == APIError::OK) {
-    return "OK";
+    return LOG_STR("OK");
   } else if (err == APIError::WOULD_BLOCK) {
-    return "WOULD_BLOCK";
+    return LOG_STR("WOULD_BLOCK");
   } else if (err == APIError::BAD_INDICATOR) {
-    return "BAD_INDICATOR";
+    return LOG_STR("BAD_INDICATOR");
   } else if (err == APIError::BAD_DATA_PACKET) {
-    return "BAD_DATA_PACKET";
+    return LOG_STR("BAD_DATA_PACKET");
   } else if (err == APIError::TCP_NODELAY_FAILED) {
-    return "TCP_NODELAY_FAILED";
+    return LOG_STR("TCP_NODELAY_FAILED");
   } else if (err == APIError::TCP_NONBLOCKING_FAILED) {
-    return "TCP_NONBLOCKING_FAILED";
+    return LOG_STR("TCP_NONBLOCKING_FAILED");
   } else if (err == APIError::CLOSE_FAILED) {
-    return "CLOSE_FAILED";
+    return LOG_STR("CLOSE_FAILED");
   } else if (err == APIError::SHUTDOWN_FAILED) {
-    return "SHUTDOWN_FAILED";
+    return LOG_STR("SHUTDOWN_FAILED");
   } else if (err == APIError::BAD_STATE) {
-    return "BAD_STATE";
+    return LOG_STR("BAD_STATE");
   } else if (err == APIError::BAD_ARG) {
-    return "BAD_ARG";
+    return LOG_STR("BAD_ARG");
   } else if (err == APIError::SOCKET_READ_FAILED) {
-    return "SOCKET_READ_FAILED";
+    return LOG_STR("SOCKET_READ_FAILED");
   } else if (err == APIError::SOCKET_WRITE_FAILED) {
-    return "SOCKET_WRITE_FAILED";
+    return LOG_STR("SOCKET_WRITE_FAILED");
   } else if (err == APIError::OUT_OF_MEMORY) {
-    return "OUT_OF_MEMORY";
+    return LOG_STR("OUT_OF_MEMORY");
   } else if (err == APIError::CONNECTION_CLOSED) {
-    return "CONNECTION_CLOSED";
+    return LOG_STR("CONNECTION_CLOSED");
   }
 #ifdef USE_API_NOISE
   else if (err == APIError::BAD_HANDSHAKE_PACKET_LEN) {
-    return "BAD_HANDSHAKE_PACKET_LEN";
+    return LOG_STR("BAD_HANDSHAKE_PACKET_LEN");
   } else if (err == APIError::HANDSHAKESTATE_READ_FAILED) {
-    return "HANDSHAKESTATE_READ_FAILED";
+    return LOG_STR("HANDSHAKESTATE_READ_FAILED");
   } else if (err == APIError::HANDSHAKESTATE_WRITE_FAILED) {
-    return "HANDSHAKESTATE_WRITE_FAILED";
+    return LOG_STR("HANDSHAKESTATE_WRITE_FAILED");
   } else if (err == APIError::HANDSHAKESTATE_BAD_STATE) {
-    return "HANDSHAKESTATE_BAD_STATE";
+    return LOG_STR("HANDSHAKESTATE_BAD_STATE");
   } else if (err == APIError::CIPHERSTATE_DECRYPT_FAILED) {
-    return "CIPHERSTATE_DECRYPT_FAILED";
+    return LOG_STR("CIPHERSTATE_DECRYPT_FAILED");
   } else if (err == APIError::CIPHERSTATE_ENCRYPT_FAILED) {
-    return "CIPHERSTATE_ENCRYPT_FAILED";
+    return LOG_STR("CIPHERSTATE_ENCRYPT_FAILED");
   } else if (err == APIError::HANDSHAKESTATE_SETUP_FAILED) {
-    return "HANDSHAKESTATE_SETUP_FAILED";
+    return LOG_STR("HANDSHAKESTATE_SETUP_FAILED");
   } else if (err == APIError::HANDSHAKESTATE_SPLIT_FAILED) {
-    return "HANDSHAKESTATE_SPLIT_FAILED";
+    return LOG_STR("HANDSHAKESTATE_SPLIT_FAILED");
   } else if (err == APIError::BAD_HANDSHAKE_ERROR_BYTE) {
-    return "BAD_HANDSHAKE_ERROR_BYTE";
+    return LOG_STR("BAD_HANDSHAKE_ERROR_BYTE");
   }
 #endif
-  return "UNKNOWN";
+  return LOG_STR("UNKNOWN");
 }
 
 // Default implementation for loop - handles sending buffered data

esphome/components/api/api_frame_helper.h

@@ -66,7 +66,7 @@ enum class APIError : uint16_t {
 #endif
 };
 
-const char *api_error_to_str(APIError err);
+const LogString *api_error_to_logstr(APIError err);
 
 class APIFrameHelper {
  public:

esphome/components/api/api_frame_helper_noise.cpp

@@ -27,42 +27,42 @@ static constexpr size_t PROLOGUE_INIT_LEN = 12;  // strlen("NoiseAPIInit")
 #endif
 
 /// Convert a noise error code to a readable error
-std::string noise_err_to_str(int err) {
+const LogString *noise_err_to_logstr(int err) {
   if (err == NOISE_ERROR_NO_MEMORY)
-    return "NO_MEMORY";
+    return LOG_STR("NO_MEMORY");
   if (err == NOISE_ERROR_UNKNOWN_ID)
-    return "UNKNOWN_ID";
+    return LOG_STR("UNKNOWN_ID");
   if (err == NOISE_ERROR_UNKNOWN_NAME)
-    return "UNKNOWN_NAME";
+    return LOG_STR("UNKNOWN_NAME");
   if (err == NOISE_ERROR_MAC_FAILURE)
-    return "MAC_FAILURE";
+    return LOG_STR("MAC_FAILURE");
   if (err == NOISE_ERROR_NOT_APPLICABLE)
-    return "NOT_APPLICABLE";
+    return LOG_STR("NOT_APPLICABLE");
   if (err == NOISE_ERROR_SYSTEM)
-    return "SYSTEM";
+    return LOG_STR("SYSTEM");
   if (err == NOISE_ERROR_REMOTE_KEY_REQUIRED)
-    return "REMOTE_KEY_REQUIRED";
+    return LOG_STR("REMOTE_KEY_REQUIRED");
   if (err == NOISE_ERROR_LOCAL_KEY_REQUIRED)
-    return "LOCAL_KEY_REQUIRED";
+    return LOG_STR("LOCAL_KEY_REQUIRED");
   if (err == NOISE_ERROR_PSK_REQUIRED)
-    return "PSK_REQUIRED";
+    return LOG_STR("PSK_REQUIRED");
   if (err == NOISE_ERROR_INVALID_LENGTH)
-    return "INVALID_LENGTH";
+    return LOG_STR("INVALID_LENGTH");
   if (err == NOISE_ERROR_INVALID_PARAM)
-    return "INVALID_PARAM";
+    return LOG_STR("INVALID_PARAM");
   if (err == NOISE_ERROR_INVALID_STATE)
-    return "INVALID_STATE";
+    return LOG_STR("INVALID_STATE");
   if (err == NOISE_ERROR_INVALID_NONCE)
-    return "INVALID_NONCE";
+    return LOG_STR("INVALID_NONCE");
   if (err == NOISE_ERROR_INVALID_PRIVATE_KEY)
-    return "INVALID_PRIVATE_KEY";
+    return LOG_STR("INVALID_PRIVATE_KEY");
   if (err == NOISE_ERROR_INVALID_PUBLIC_KEY)
-    return "INVALID_PUBLIC_KEY";
+    return LOG_STR("INVALID_PUBLIC_KEY");
   if (err == NOISE_ERROR_INVALID_FORMAT)
-    return "INVALID_FORMAT";
+    return LOG_STR("INVALID_FORMAT");
   if (err == NOISE_ERROR_INVALID_SIGNATURE)
-    return "INVALID_SIGNATURE";
+    return LOG_STR("INVALID_SIGNATURE");
-  return to_string(err);
+  return LOG_STR("UNKNOWN");
 }
 
 /// Initialize the frame helper, returns OK if successful.
@@ -83,18 +83,18 @@ APIError APINoiseFrameHelper::init() {
 // Helper for handling handshake frame errors
 APIError APINoiseFrameHelper::handle_handshake_frame_error_(APIError aerr) {
   if (aerr == APIError::BAD_INDICATOR) {
-    send_explicit_handshake_reject_("Bad indicator byte");
+    send_explicit_handshake_reject_(LOG_STR("Bad indicator byte"));
   } else if (aerr == APIError::BAD_HANDSHAKE_PACKET_LEN) {
-    send_explicit_handshake_reject_("Bad handshake packet len");
+    send_explicit_handshake_reject_(LOG_STR("Bad handshake packet len"));
   }
   return aerr;
 }
 
 // Helper for handling noise library errors
-APIError APINoiseFrameHelper::handle_noise_error_(int err, const char *func_name, APIError api_err) {
+APIError APINoiseFrameHelper::handle_noise_error_(int err, const LogString *func_name, APIError api_err) {
   if (err != 0) {
     state_ = State::FAILED;
-    HELPER_LOG("%s failed: %s", func_name, noise_err_to_str(err).c_str());
+    HELPER_LOG("%s failed: %s", LOG_STR_ARG(func_name), LOG_STR_ARG(noise_err_to_logstr(err)));
     return api_err;
   }
   return APIError::OK;
@@ -279,11 +279,11 @@ APIError APINoiseFrameHelper::state_action_() {
       }
 
       if (frame.empty()) {
-        send_explicit_handshake_reject_("Empty handshake message");
+        send_explicit_handshake_reject_(LOG_STR("Empty handshake message"));
         return APIError::BAD_HANDSHAKE_ERROR_BYTE;
       } else if (frame[0] != 0x00) {
         HELPER_LOG("Bad handshake error byte: %u", frame[0]);
-        send_explicit_handshake_reject_("Bad handshake error byte");
+        send_explicit_handshake_reject_(LOG_STR("Bad handshake error byte"));
         return APIError::BAD_HANDSHAKE_ERROR_BYTE;
       }
 
@@ -293,8 +293,10 @@ APIError APINoiseFrameHelper::state_action_() {
       err = noise_handshakestate_read_message(handshake_, &mbuf, nullptr);
       if (err != 0) {
         // Special handling for MAC failure
-        send_explicit_handshake_reject_(err == NOISE_ERROR_MAC_FAILURE ? "Handshake MAC failure" : "Handshake error");
+        send_explicit_handshake_reject_(err == NOISE_ERROR_MAC_FAILURE ? LOG_STR("Handshake MAC failure")
-        return handle_noise_error_(err, "noise_handshakestate_read_message", APIError::HANDSHAKESTATE_READ_FAILED);
+                                                                       : LOG_STR("Handshake error"));
+        return handle_noise_error_(err, LOG_STR("noise_handshakestate_read_message"),
+                                   APIError::HANDSHAKESTATE_READ_FAILED);
       }
 
       aerr = check_handshake_finished_();
@@ -307,8 +309,8 @@ APIError APINoiseFrameHelper::state_action_() {
       noise_buffer_set_output(mbuf, buffer + 1, sizeof(buffer) - 1);
 
       err = noise_handshakestate_write_message(handshake_, &mbuf, nullptr);
-      APIError aerr_write =
+      APIError aerr_write = handle_noise_error_(err, LOG_STR("noise_handshakestate_write_message"),
-          handle_noise_error_(err, "noise_handshakestate_write_message", APIError::HANDSHAKESTATE_WRITE_FAILED);
+                                                APIError::HANDSHAKESTATE_WRITE_FAILED);
       if (aerr_write != APIError::OK)
         return aerr_write;
       buffer[0] = 0x00;  // success
@@ -331,15 +333,31 @@ APIError APINoiseFrameHelper::state_action_() {
   }
   return APIError::OK;
 }
-void APINoiseFrameHelper::send_explicit_handshake_reject_(const std::string &reason) {
+void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reason) {
+#ifdef USE_STORE_LOG_STR_IN_FLASH
+  // On ESP8266 with flash strings, we need to use PROGMEM-aware functions
+  size_t reason_len = strlen_P(reinterpret_cast<PGM_P>(reason));
   std::vector<uint8_t> data;
-  data.resize(reason.length() + 1);
+  data.resize(reason_len + 1);
+  data[0] = 0x01;  // failure
+
+  // Copy error message from PROGMEM
+  if (reason_len > 0) {
+    memcpy_P(data.data() + 1, reinterpret_cast<PGM_P>(reason), reason_len);
+  }
+#else
+  // Normal memory access
+  const char *reason_str = LOG_STR_ARG(reason);
+  size_t reason_len = strlen(reason_str);
+  std::vector<uint8_t> data;
+  data.resize(reason_len + 1);
   data[0] = 0x01;  // failure
 
   // Copy error message in bulk
-  if (!reason.empty()) {
+  if (reason_len > 0) {
-    std::memcpy(data.data() + 1, reason.c_str(), reason.length());
+    std::memcpy(data.data() + 1, reason_str, reason_len);
   }
+#endif
 
   // temporarily remove failed state
   auto orig_state = state_;
@@ -368,7 +386,8 @@ APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {
   noise_buffer_init(mbuf);
   noise_buffer_set_inout(mbuf, frame.data(), frame.size(), frame.size());
   err = noise_cipherstate_decrypt(recv_cipher_, &mbuf);
-  APIError decrypt_err = handle_noise_error_(err, "noise_cipherstate_decrypt", APIError::CIPHERSTATE_DECRYPT_FAILED);
+  APIError decrypt_err =
+      handle_noise_error_(err, LOG_STR("noise_cipherstate_decrypt"), APIError::CIPHERSTATE_DECRYPT_FAILED);
   if (decrypt_err != APIError::OK)
     return decrypt_err;
 
@@ -450,7 +469,8 @@ APIError APINoiseFrameHelper::write_protobuf_packets(ProtoWriteBuffer buffer, st
                            4 + packet.payload_size + frame_footer_size_);
 
     int err = noise_cipherstate_encrypt(send_cipher_, &mbuf);
-    APIError aerr = handle_noise_error_(err, "noise_cipherstate_encrypt", APIError::CIPHERSTATE_ENCRYPT_FAILED);
+    APIError aerr =
+        handle_noise_error_(err, LOG_STR("noise_cipherstate_encrypt"), APIError::CIPHERSTATE_ENCRYPT_FAILED);
     if (aerr != APIError::OK)
       return aerr;
 
@@ -504,25 +524,27 @@ APIError APINoiseFrameHelper::init_handshake_() {
   nid_.modifier_ids[0] = NOISE_MODIFIER_PSK0;
 
   err = noise_handshakestate_new_by_id(&handshake_, &nid_, NOISE_ROLE_RESPONDER);
-  APIError aerr = handle_noise_error_(err, "noise_handshakestate_new_by_id", APIError::HANDSHAKESTATE_SETUP_FAILED);
+  APIError aerr =
+      handle_noise_error_(err, LOG_STR("noise_handshakestate_new_by_id"), APIError::HANDSHAKESTATE_SETUP_FAILED);
   if (aerr != APIError::OK)
     return aerr;
 
   const auto &psk = ctx_->get_psk();
   err = noise_handshakestate_set_pre_shared_key(handshake_, psk.data(), psk.size());
-  aerr = handle_noise_error_(err, "noise_handshakestate_set_pre_shared_key", APIError::HANDSHAKESTATE_SETUP_FAILED);
+  aerr = handle_noise_error_(err, LOG_STR("noise_handshakestate_set_pre_shared_key"),
+                             APIError::HANDSHAKESTATE_SETUP_FAILED);
   if (aerr != APIError::OK)
     return aerr;
 
   err = noise_handshakestate_set_prologue(handshake_, prologue_.data(), prologue_.size());
-  aerr = handle_noise_error_(err, "noise_handshakestate_set_prologue", APIError::HANDSHAKESTATE_SETUP_FAILED);
+  aerr = handle_noise_error_(err, LOG_STR("noise_handshakestate_set_prologue"), APIError::HANDSHAKESTATE_SETUP_FAILED);
   if (aerr != APIError::OK)
     return aerr;
   // set_prologue copies it into handshakestate, so we can get rid of it now
   prologue_ = {};
 
   err = noise_handshakestate_start(handshake_);
-  aerr = handle_noise_error_(err, "noise_handshakestate_start", APIError::HANDSHAKESTATE_SETUP_FAILED);
+  aerr = handle_noise_error_(err, LOG_STR("noise_handshakestate_start"), APIError::HANDSHAKESTATE_SETUP_FAILED);
   if (aerr != APIError::OK)
     return aerr;
   return APIError::OK;
@@ -540,7 +562,8 @@ APIError APINoiseFrameHelper::check_handshake_finished_() {
     return APIError::HANDSHAKESTATE_BAD_STATE;
   }
   int err = noise_handshakestate_split(handshake_, &send_cipher_, &recv_cipher_);
-  APIError aerr = handle_noise_error_(err, "noise_handshakestate_split", APIError::HANDSHAKESTATE_SPLIT_FAILED);
+  APIError aerr =
+      handle_noise_error_(err, LOG_STR("noise_handshakestate_split"), APIError::HANDSHAKESTATE_SPLIT_FAILED);
   if (aerr != APIError::OK)
     return aerr;
 

esphome/components/api/api_frame_helper_noise.h

@@ -32,9 +32,9 @@ class APINoiseFrameHelper final : public APIFrameHelper {
   APIError write_frame_(const uint8_t *data, uint16_t len);
   APIError init_handshake_();
   APIError check_handshake_finished_();
-  void send_explicit_handshake_reject_(const std::string &reason);
+  void send_explicit_handshake_reject_(const LogString *reason);
   APIError handle_handshake_frame_error_(APIError aerr);
-  APIError handle_noise_error_(int err, const char *func_name, APIError api_err);
+  APIError handle_noise_error_(int err, const LogString *func_name, APIError api_err);
 
   // Pointers first (4 bytes each)
   NoiseHandshakeState *handshake_{nullptr};