Add configurable Wi-Fi station mDNS hostname support. Mini-Feature #1

src/mdns_service.c

@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-3.0-only */
+/* mDNS runtime service; its lifecycle is owned by wifi_manager. */
+
+#include "mdns_service.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/semphr.h"
+#include "mdns.h"
+
+static SemaphoreHandle_t s_mutex;
+static mdns_config_t s_config;
+static bool s_announced;
+static esp_err_t s_last_error;
+
+static void lock_service(void)
+{
+    (void)xSemaphoreTake(s_mutex, portMAX_DELAY);
+}
+
+static void unlock_service(void)
+{
+    (void)xSemaphoreGive(s_mutex);
+}
+
+static void make_hostname(const mdns_config_t *config, char *hostname, size_t size)
+{
+    (void)snprintf(hostname, size, "sak-%s", config->suffix);
+}
+
+esp_err_t mdns_service_init(const mdns_config_t *config)
+{
+    if (mdns_config_validate(config) != ESP_OK) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    if (s_mutex != NULL) {
+        return ESP_ERR_INVALID_STATE;
+    }
+    s_mutex = xSemaphoreCreateMutex();
+    if (s_mutex == NULL) {
+        return ESP_ERR_NO_MEM;
+    }
+    s_config = *config;
+    s_last_error = ESP_OK;
+    return ESP_OK;
+}
+
+esp_err_t mdns_service_get_config(mdns_config_t *config)
+{
+    if (config == NULL || s_mutex == NULL) {
+        return ESP_ERR_INVALID_STATE;
+    }
+    lock_service();
+    *config = s_config;
+    unlock_service();
+    return ESP_OK;
+}
+
+esp_err_t mdns_service_set_config(const mdns_config_t *config)
+{
+    if (s_mutex == NULL || mdns_config_validate(config) != ESP_OK) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    lock_service();
+    s_config = *config;
+    unlock_service();
+    return ESP_OK;
+}
+
+esp_err_t mdns_service_get_snapshot(mdns_service_snapshot_t *snapshot)
+{
+    if (snapshot == NULL || s_mutex == NULL) {
+        return ESP_ERR_INVALID_STATE;
+    }
+    lock_service();
+    memset(snapshot, 0, sizeof(*snapshot));
+    snapshot->initialized = true;
+    snapshot->announced = s_announced;
+    memcpy(snapshot->suffix, s_config.suffix, s_config.suffix_len);
+    make_hostname(&s_config, snapshot->hostname, sizeof(snapshot->hostname));
+    snapshot->last_error = s_last_error;
+    unlock_service();
+    return ESP_OK;
+}
+
+esp_err_t mdns_service_start(void)
+{
+    if (s_mutex == NULL) {
+        return ESP_ERR_INVALID_STATE;
+    }
+    lock_service();
+    if (s_announced) {
+        unlock_service();
+        return ESP_OK;
+    }
+    mdns_config_t config = s_config;
+    unlock_service();
+
+    esp_err_t error = mdns_init();
+    if (error == ESP_OK) {
+        char hostname[MDNS_CONFIG_SUFFIX_MAX_LEN + 5U] = {0};
+        make_hostname(&config, hostname, sizeof(hostname));
+        error = mdns_hostname_set(hostname);
+        if (error == ESP_OK) {
+            error = mdns_instance_name_set("ESP32 Serial Swiss Army Knife");
+        }
+        if (error != ESP_OK) {
+            mdns_free();
+        }
+    }
+
+    lock_service();
+    s_announced = error == ESP_OK;
+    s_last_error = error;
+    unlock_service();
+    return error;
+}
+
+void mdns_service_stop(void)
+{
+    if (s_mutex == NULL) {
+        return;
+    }
+    lock_service();
+    bool announced = s_announced;
+    s_announced = false;
+    unlock_service();
+    if (announced) {
+        mdns_free();
+    }
+}