mDNS updates (#4399)

esphome/components/mdns/mdns_esp32.cpp

@@ -0,0 +1,59 @@
+#ifdef USE_ESP32
+
+#include <mdns.h>
+#include <cstring>
+#include "esphome/core/hal.h"
+#include "esphome/core/log.h"
+#include "mdns_component.h"
+
+namespace esphome {
+namespace mdns {
+
+static const char *const TAG = "mdns";
+
+void MDNSComponent::setup() {
+  this->compile_records_();
+
+  esp_err_t err = mdns_init();
+  if (err != ESP_OK) {
+    ESP_LOGW(TAG, "mDNS init failed: %s", esp_err_to_name(err));
+    this->mark_failed();
+    return;
+  }
+
+  mdns_hostname_set(this->hostname_.c_str());
+  mdns_instance_name_set(this->hostname_.c_str());
+
+  for (const auto &service : this->services_) {
+    std::vector<mdns_txt_item_t> txt_records;
+    for (const auto &record : service.txt_records) {
+      mdns_txt_item_t it{};
+      // dup strings to ensure the pointer is valid even after the record loop
+      it.key = strdup(record.key.c_str());
+      it.value = strdup(record.value.c_str());
+      txt_records.push_back(it);
+    }
+    err = mdns_service_add(nullptr, service.service_type.c_str(), service.proto.c_str(), service.port,
+                           txt_records.data(), txt_records.size());
+
+    // free records
+    for (const auto &it : txt_records) {
+      delete it.key;    // NOLINT(cppcoreguidelines-owning-memory)
+      delete it.value;  // NOLINT(cppcoreguidelines-owning-memory)
+    }
+
+    if (err != ESP_OK) {
+      ESP_LOGW(TAG, "Failed to register mDNS service %s: %s", service.service_type.c_str(), esp_err_to_name(err));
+    }
+  }
+}
+
+void MDNSComponent::on_shutdown() {
+  mdns_free();
+  delay(40);  // Allow the mdns packets announcing service removal to be sent
+}
+
+}  // namespace mdns
+}  // namespace esphome
+
+#endif  // USE_ESP32