From 29374837c68d8643c61b35803130b829eca84268 Mon Sep 17 00:00:00 2001 From: "J. Nick Koston" Date: Tue, 18 Nov 2025 17:06:34 -0600 Subject: [PATCH] [wifi, captive_portal, web_server, wifi_info] Use stack allocation for MAC address formatting (#11963) --- esphome/components/captive_portal/captive_portal.cpp | 6 ++++-- esphome/components/web_server/web_server.cpp | 4 ++-- esphome/components/wifi/wifi_component.cpp | 6 ++++-- esphome/components/wifi_info/wifi_info_text_sensor.h | 5 ++++- esphome/core/helpers.cpp | 12 +++++++++--- esphome/core/helpers.h | 5 +++++ 6 files changed, 28 insertions(+), 10 deletions(-) diff --git a/esphome/components/captive_portal/captive_portal.cpp b/esphome/components/captive_portal/captive_portal.cpp index 459ac557c..4eb00835b 100644 --- a/esphome/components/captive_portal/captive_portal.cpp +++ b/esphome/components/captive_portal/captive_portal.cpp @@ -13,14 +13,16 @@ static const char *const TAG = "captive_portal"; void CaptivePortal::handle_config(AsyncWebServerRequest *request) { AsyncResponseStream *stream = request->beginResponseStream(ESPHOME_F("application/json")); stream->addHeader(ESPHOME_F("cache-control"), ESPHOME_F("public, max-age=0, must-revalidate")); + char mac_s[18]; + const char *mac_str = get_mac_address_pretty_into_buffer(mac_s); #ifdef USE_ESP8266 stream->print(ESPHOME_F("{\"mac\":\"")); - stream->print(get_mac_address_pretty().c_str()); + stream->print(mac_str); stream->print(ESPHOME_F("\",\"name\":\"")); stream->print(App.get_name().c_str()); stream->print(ESPHOME_F("\",\"aps\":[{}")); #else - stream->printf(R"({"mac":"%s","name":"%s","aps":[{})", get_mac_address_pretty().c_str(), App.get_name().c_str()); + stream->printf(R"({"mac":"%s","name":"%s","aps":[{})", mac_str, App.get_name().c_str()); #endif for (auto &scan : wifi::global_wifi_component->get_scan_result()) { diff --git a/esphome/components/web_server/web_server.cpp b/esphome/components/web_server/web_server.cpp index 5a8128ba4..cc51463fe 100644 --- a/esphome/components/web_server/web_server.cpp +++ b/esphome/components/web_server/web_server.cpp @@ -359,8 +359,8 @@ void WebServer::handle_pna_cors_request(AsyncWebServerRequest *request) { AsyncWebServerResponse *response = request->beginResponse(200, ""); response->addHeader(HEADER_CORS_ALLOW_PNA, "true"); response->addHeader(HEADER_PNA_NAME, App.get_name().c_str()); - std::string mac = get_mac_address_pretty(); - response->addHeader(HEADER_PNA_ID, mac.c_str()); + char mac_s[18]; + response->addHeader(HEADER_PNA_ID, get_mac_address_pretty_into_buffer(mac_s)); request->send(response); } #endif diff --git a/esphome/components/wifi/wifi_component.cpp b/esphome/components/wifi/wifi_component.cpp index 30340601f..6f698bc2a 100644 --- a/esphome/components/wifi/wifi_component.cpp +++ b/esphome/components/wifi/wifi_component.cpp @@ -341,10 +341,11 @@ void WiFiComponent::setup() { } void WiFiComponent::start() { + char mac_s[18]; ESP_LOGCONFIG(TAG, "Starting\n" " Local MAC: %s", - get_mac_address_pretty().c_str()); + get_mac_address_pretty_into_buffer(mac_s)); this->last_connected_ = millis(); uint32_t hash = this->has_sta() ? fnv1_hash(App.get_compilation_time()) : 88491487UL; @@ -826,7 +827,8 @@ void WiFiComponent::print_connect_params_() { char bssid_s[18]; format_mac_addr_upper(bssid.data(), bssid_s); - ESP_LOGCONFIG(TAG, " Local MAC: %s", get_mac_address_pretty().c_str()); + char mac_s[18]; + ESP_LOGCONFIG(TAG, " Local MAC: %s", get_mac_address_pretty_into_buffer(mac_s)); if (this->is_disabled()) { ESP_LOGCONFIG(TAG, " Disabled"); return; diff --git a/esphome/components/wifi_info/wifi_info_text_sensor.h b/esphome/components/wifi_info/wifi_info_text_sensor.h index 04889d6bb..0814336c4 100644 --- a/esphome/components/wifi_info/wifi_info_text_sensor.h +++ b/esphome/components/wifi_info/wifi_info_text_sensor.h @@ -126,7 +126,10 @@ class BSSIDWiFiInfo : public PollingComponent, public text_sensor::TextSensor { class MacAddressWifiInfo : public Component, public text_sensor::TextSensor { public: - void setup() override { this->publish_state(get_mac_address_pretty()); } + void setup() override { + char mac_s[18]; + this->publish_state(get_mac_address_pretty_into_buffer(mac_s)); + } void dump_config() override; }; diff --git a/esphome/core/helpers.cpp b/esphome/core/helpers.cpp index 568acb9f1..50af71649 100644 --- a/esphome/core/helpers.cpp +++ b/esphome/core/helpers.cpp @@ -638,9 +638,8 @@ std::string get_mac_address() { } std::string get_mac_address_pretty() { - uint8_t mac[6]; - get_mac_address_raw(mac); - return format_mac_address_pretty(mac); + char buf[18]; + return std::string(get_mac_address_pretty_into_buffer(buf)); } void get_mac_address_into_buffer(std::span buf) { @@ -649,6 +648,13 @@ void get_mac_address_into_buffer(std::span buf) { format_mac_addr_lower_no_sep(mac, buf.data()); } +const char *get_mac_address_pretty_into_buffer(std::span buf) { + uint8_t mac[6]; + get_mac_address_raw(mac); + format_mac_addr_upper(mac, buf.data()); + return buf.data(); +} + #ifndef USE_ESP32 bool has_custom_mac_address() { return false; } #endif diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h index 16eab8b8f..d8c1f4647 100644 --- a/esphome/core/helpers.h +++ b/esphome/core/helpers.h @@ -1052,6 +1052,11 @@ std::string get_mac_address_pretty(); /// Assumes buffer length is 13 (12 digits for hexadecimal representation followed by null terminator). void get_mac_address_into_buffer(std::span buf); +/// Get the device MAC address into the given buffer, in colon-separated uppercase hex notation. +/// Buffer must be exactly 18 bytes (17 for "XX:XX:XX:XX:XX:XX" + null terminator). +/// Returns pointer to the buffer for convenience. +const char *get_mac_address_pretty_into_buffer(std::span buf); + #ifdef USE_ESP32 /// Set the MAC address to use from the provided byte array (6 bytes). void set_mac_address(uint8_t *mac);