mdns_esp32.cpp

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#include "esphome/core/defines.h"
#if defined(USE_ESP32) && defined(USE_MDNS)
 
#include <mdns.h>
#include "esphome/core/application.h"
#include "esphome/core/hal.h"
#include "esphome/core/log.h"
#include "mdns_component.h"
 
namespace esphome::mdns {
 
static const char *const TAG = "mdns";
 
static void register_esp32(MDNSComponent *comp, StaticVector<MDNSService, MDNS_SERVICE_COUNT> &services) {
#ifdef USE_OPENTHREAD
  // OpenThread handles service registration via SRP client
  // Services are compiled by MDNSComponent::compile_records_() and consumed by OpenThreadSrpComponent
#else
  esp_err_t err = mdns_init();
  if (err != ESP_OK) {
    ESP_LOGW(TAG, "Init failed: %s", esp_err_to_name(err));
    comp->mark_failed();
    return;
  }
 
  const char *hostname = App.get_name().c_str();
  mdns_hostname_set(hostname);
  mdns_instance_name_set(hostname);
 
  for (const auto &service : services) {
    // Stack buffer for up to 16 txt records, heap fallback for more
    SmallBufferWithHeapFallback<16, mdns_txt_item_t> txt_records(service.txt_records.size());
    for (size_t i = 0; i < service.txt_records.size(); i++) {
      const auto &record = service.txt_records[i];
      // key and value are either compile-time string literals in flash or pointers to dynamic_txt_values_
      // Both remain valid for the lifetime of this function, and ESP-IDF makes internal copies
      txt_records.get()[i].key = MDNS_STR_ARG(record.key);
      txt_records.get()[i].value = MDNS_STR_ARG(record.value);
    }
    uint16_t port = const_cast<TemplatableValue<uint16_t> &>(service.port).value();
    err = mdns_service_add(nullptr, MDNS_STR_ARG(service.service_type), MDNS_STR_ARG(service.proto), port,
                           txt_records.get(), service.txt_records.size());
 
    if (err != ESP_OK) {
      ESP_LOGW(TAG, "Failed to register service %s: %s", MDNS_STR_ARG(service.service_type), esp_err_to_name(err));
    }
  }
#endif
}
 
void MDNSComponent::setup() { this->setup_buffers_and_register_(register_esp32); }
 
void MDNSComponent::on_shutdown() {
#ifndef USE_OPENTHREAD
  mdns_free();
  delay(40);  // Allow the mdns packets announcing service removal to be sent
#endif
}
 
}  // namespace esphome::mdns
 
#endif  // USE_ESP32