pppos_client_test.c

/* PPPoS Client Example

   This example code is in the Public Domain (or CC0 licensed, at your option.)

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "esp_netif.h"
#include "esp_netif_ppp.h"
#include "esp_modem.h"
#include "esp_modem_netif.h"
#include "esp_log.h"
#include "lwip/err.h"
#include "lwip/sockets.h"
#include "null_dce.h"

static const char *TAG = "pppos_test";
static EventGroupHandle_t event_group = NULL;
static const int CONNECT_BIT = BIT0;
static const int STOP_BIT = BIT1;
static const int DISCONNECT_BIT = BIT2;

static void modem_event_handler(void *event_handler_arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
{
    switch (event_id) {
    case ESP_MODEM_EVENT_PPP_START:
        ESP_LOGI(TAG, "Modem PPP Started");
        break;
    case ESP_MODEM_EVENT_PPP_STOP:
        ESP_LOGI(TAG, "Modem PPP Stopped");
        xEventGroupSetBits(event_group, STOP_BIT);
        break;
    case ESP_MODEM_EVENT_UNKNOWN:
        ESP_LOGW(TAG, "Unknow line received: %s", (char *)event_data);
        break;
    default:
        break;
    }
}

static void on_ppp_changed(void *arg, esp_event_base_t event_base,
                        int32_t event_id, void *event_data)
{
    ESP_LOGI(TAG, "PPP state changed event %d", event_id);
    if (event_id == NETIF_PPP_PHASE_DISCONNECT) {
        xEventGroupSetBits(event_group, DISCONNECT_BIT);
    }
}


static void on_ip_event(void *arg, esp_event_base_t event_base,
                      int32_t event_id, void *event_data)
{
    if (event_id == IP_EVENT_PPP_GOT_IP) {
        ESP_LOGI(TAG, "GOT ip event!!!");

        ip_event_got_ip_t *event = (ip_event_got_ip_t *)event_data;

        ESP_LOGI(TAG, "PPP client connected to PPP Server");
        ESP_LOGI(TAG, "IP          : " IPSTR, IP2STR(&event->ip_info.ip));
        ESP_LOGI(TAG, "Netmask     : " IPSTR, IP2STR(&event->ip_info.netmask));
        ESP_LOGI(TAG, "Gateway     : " IPSTR, IP2STR(&event->ip_info.gw));
        xEventGroupSetBits(event_group, CONNECT_BIT);

    } else if (event_id == IP_EVENT_PPP_LOST_IP) {
        ESP_LOGI(TAG, "Modem Disconnect from PPP Server");
    } else if (event_id == IP_EVENT_GOT_IP6) {
        ESP_LOGI(TAG, "GOT IPv6 event!");

        ip_event_got_ip6_t *event = (ip_event_got_ip6_t *)event_data;
        ESP_LOGI(TAG, "Got IPv6 address " IPV6STR, IPV62STR(event->ip6_info.ip));
    }
}

void app_main(void) {

    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());
    ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, ESP_EVENT_ANY_ID, &on_ip_event, NULL));
    ESP_ERROR_CHECK(esp_event_handler_register(NETIF_PPP_STATUS, ESP_EVENT_ANY_ID, &on_ppp_changed, NULL));

  while (1) {
      event_group = xEventGroupCreate();
      /* create dte object */
      esp_modem_dte_config_t config = ESP_MODEM_DTE_DEFAULT_CONFIG();
      /* setup UART specific configuration based on kconfig options */
      config.rx_io_num = 26;
      config.tx_io_num = 25;
      modem_dte_t *dte = esp_modem_dte_init(&config);
      /* Register event handler */
      ESP_ERROR_CHECK(esp_modem_set_event_handler(dte, modem_event_handler, ESP_EVENT_ANY_ID, NULL));

      // Init netif object
      esp_netif_config_t cfg = ESP_NETIF_DEFAULT_PPP();
      esp_netif_t *esp_netif = esp_netif_new(&cfg);
      assert(esp_netif);

      void *modem_netif_adapter = esp_modem_netif_setup(dte);
      esp_modem_netif_set_default_handlers(modem_netif_adapter, esp_netif);

      modem_dce_t *dce = null_dce_init(dte);
      /* attach the modem to the network interface */
      esp_netif_attach(esp_netif, modem_netif_adapter);
      /* Wait for IP address */
      xEventGroupWaitBits(event_group, CONNECT_BIT, pdTRUE, pdTRUE, portMAX_DELAY);
      ESP_LOGI(TAG, "CONNECTED!");
      ESP_LOGI(TAG, "STOP");
      ESP_ERROR_CHECK(esp_modem_stop_ppp(dte));
      esp_modem_netif_clear_default_handlers(modem_netif_adapter);
      esp_modem_netif_teardown(modem_netif_adapter);
      esp_netif_destroy(esp_netif);
      ESP_LOGD(TAG, "netif destroyed");
      xEventGroupWaitBits(event_group, STOP_BIT, pdTRUE, pdTRUE, portMAX_DELAY);
      ESP_ERROR_CHECK(dce->deinit(dce));
      ESP_ERROR_CHECK(dte->deinit(dte));
      vEventGroupDelete(event_group);
      event_group = NULL;
      ESP_LOGI(TAG, "All deleted");
  }

}

This work for me but if you add any TCP protocol in between line 110 and 111 then sometime it will crash. For example, create one thread there and connect to mqtt client and after connections try to publish something. It will hang in tcp_ip thread or crash saying that PPP connections can not be started. But it only happens 2-3 times in 30-40 try. I am using Telit MG910 modem with ESP32S2.

This work for me but if you add any TCP protocol in between line 110 and 111 then sometime it will crash. For example, create one thread there and connect to mqtt client and after connections try to publish something. It will hang in tcp_ip thread or crash saying that PPP connections can not be started. But it only happens 2-3 times in 30-40 try. I am using Telit MG910 modem with ESP32S2.

For me, got crash with xQueueGenericSend when I add some TCP between connected and stop as well.

PC: 0x40089fbc: xQueueGenericSend at /Users/chamroeun/.platformio/packages/framework-espidf/components/freertos/queue.c line 821
EXCVADDR: 0x07d21e60

Decoding stack results
0x40089fb9: xQueueGenericSend at /Users/chamroeun/.platformio/packages/framework-espidf/components/freertos/queue.c line 821
0x400d6985: esp_modem_notify_ppp_netif_closed at lib/modem/src/esp_modem.c line 624
0x400d7489: on_ppp_changed at lib/modem/src/esp_modem_netif.c line 36