Add esp32 example

.travis.yml

@@ -9,15 +9,12 @@ os:
 compiler:
   - clang
   - gcc
-script: make test test++ ex
+script: make test test++
 matrix:
   include:
     - os: osx
       compiler: clang
-      script: make mg_prefix
-    - os: linux
-      compiler: msvc98
-      script: make vc98 vc2017
+      script: make mg_prefix vc98 vc2017 ex
       sudo: required
       services:
         - docker

examples/esp32/CMakeLists.txt

@@ -0,0 +1,6 @@
+# The following lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(mongoose-esp32-example)

examples/esp32/Makefile

@@ -0,0 +1,10 @@
+THISDIR = $(realpath $(CURDIR))
+ROOTDIR = $(realpath $(CURDIR)/../..)
+
+all: example
+
+example:
+	docker run --rm -v $(ROOTDIR):$(ROOTDIR) -w $(THISDIR) espressif/idf idf.py build
+
+clean:
+	rm -rf $(PROG) *.o *.dSYM *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb mongoose mongoose_* mongoose.* build sdkconfig

examples/esp32/main/CMakeLists.txt

@@ -0,0 +1,4 @@
+idf_component_register(SRCS "main.c"
+                            "wifi.c"
+                            "../../../mongoose.c"
+                       INCLUDE_DIRS "../../..")

examples/esp32/main/main.c

@@ -0,0 +1,36 @@
+// Copyright (c) 2020 Cesanta Software Limited
+// All rights reserved
+
+#include "mongoose.h"
+
+#define WIFI_SSID "MY_WIFI_NETWORK"
+#define WIFI_PASS "MY_WIFI_PASSWORD"
+#define LISTENING_ADDR "http://0.0.0.0:80"
+
+// Event handler for an accepted connection
+static void cb(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
+  if (ev == MG_EV_HTTP_MSG) {
+    mg_http_reply(c, 200, "Hello from ESP32!");
+  }
+}
+
+// Called after we're connected to WiFi network
+static void start_server(void) {
+  struct mg_mgr mgr;
+  mg_log_set("3");
+  mg_mgr_init(&mgr);
+  mg_http_listen(&mgr, LISTENING_ADDR, cb, &mgr);
+  LOG(LL_INFO, ("Starting Mongoose web server v%s", MG_VERSION));
+  for (;;) mg_mgr_poll(&mgr, 1000);
+  mg_mgr_free(&mgr);
+}
+
+void app_main(void) {
+  // Setup wifi. This function is implemented in wifi.c
+  // It blocks until connected to the configured WiFi network
+  void wifi_init(const char *ssid, const char *pass);
+  wifi_init(WIFI_SSID, WIFI_PASS);
+
+  // Done connecting to WiFi, now start HTTP server
+  start_server();
+}

examples/esp32/main/wifi.c

@@ -0,0 +1,103 @@
+// Code taken from the ESP32 IDF WiFi station Example
+
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/event_groups.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "esp_event.h"
+#include "esp_log.h"
+#include "nvs_flash.h"
+
+#include "lwip/err.h"
+#include "lwip/sys.h"
+
+#include "mongoose.h"
+
+static EventGroupHandle_t s_wifi_event_group;
+
+/* The event group allows multiple bits for each event, but we only care about two events:
+ * - we are connected to the AP with an IP
+ * - we failed to connect after the maximum amount of retries */
+#define WIFI_CONNECTED_BIT BIT0
+#define WIFI_FAIL_BIT      BIT1
+
+static int s_retry_num = 0;
+
+static void event_handler(void *arg, esp_event_base_t event_base,
+                          int32_t event_id, void *event_data) {
+  if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+    esp_wifi_connect();
+  } else if (event_base == WIFI_EVENT &&
+             event_id == WIFI_EVENT_STA_DISCONNECTED) {
+    if (s_retry_num < 3) {
+      esp_wifi_connect();
+      s_retry_num++;
+      LOG(LL_INFO, ("retry to connect to the AP"));
+    } else {
+      xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
+    }
+    LOG(LL_ERROR, ("connect to the AP fail"));
+  } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
+    ip_event_got_ip_t *event = (ip_event_got_ip_t *) event_data;
+    LOG(LL_INFO, ("got ip:" IPSTR, IP2STR(&event->ip_info.ip)));
+    s_retry_num = 0;
+    xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+  }
+}
+
+void wifi_init(const char *ssid, const char *pass, void (*fn)(void)) {
+  esp_err_t ret = nvs_flash_init();
+  if (ret == ESP_ERR_NVS_NO_FREE_PAGES ||
+      ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+    ESP_ERROR_CHECK(nvs_flash_erase());
+    ret = nvs_flash_init();
+  }
+  ESP_ERROR_CHECK(ret);
+
+  s_wifi_event_group = xEventGroupCreate();
+
+  ESP_ERROR_CHECK(esp_netif_init());
+
+  ESP_ERROR_CHECK(esp_event_loop_create_default());
+  esp_netif_create_default_wifi_sta();
+
+  wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+  ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+
+  esp_event_handler_instance_t instance_any_id;
+  esp_event_handler_instance_t instance_got_ip;
+  ESP_ERROR_CHECK(esp_event_handler_instance_register(
+      WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL, &instance_any_id));
+  ESP_ERROR_CHECK(esp_event_handler_instance_register(
+      IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler, NULL, &instance_got_ip));
+
+  wifi_config_t c = {.sta = {.threshold = {.authmode = WIFI_AUTH_WPA2_PSK},
+                             .pmf_cfg = {.capable = true, .required = false}}};
+  snprintf((char *) c.sta.ssid, sizeof(c.sta.ssid), "%s", ssid);
+  snprintf((char *) c.sta.password, sizeof(c.sta.password), "%s", pass);
+  ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+  ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &c));
+  ESP_ERROR_CHECK(esp_wifi_start());
+  LOG(LL_DEBUG, ("wifi_init_sta finished."));
+
+  EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group,
+                                         WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
+                                         pdFALSE, pdFALSE, portMAX_DELAY);
+
+  if (bits & WIFI_CONNECTED_BIT) {
+    LOG(LL_INFO, ("connected to ap SSID:%s password:%s", ssid, pass));
+  } else if (bits & WIFI_FAIL_BIT) {
+    LOG(LL_ERROR, ("Failed to connect to SSID:%s, password:%s", ssid, pass));
+  } else {
+    LOG(LL_ERROR, ("UNEXPECTED EVENT"));
+  }
+
+  /* The event will not be processed after unregister */
+  ESP_ERROR_CHECK(esp_event_handler_instance_unregister(
+      IP_EVENT, IP_EVENT_STA_GOT_IP, instance_got_ip));
+  ESP_ERROR_CHECK(esp_event_handler_instance_unregister(
+      WIFI_EVENT, ESP_EVENT_ANY_ID, instance_any_id));
+  vEventGroupDelete(s_wifi_event_group);
+}