feat(examples): Support simple PPP connect in multinet example

examples/esp_netif/multiple_netifs/main/ppp_connect_simple.c

@@ -0,0 +1,122 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <string.h>
+#include "esp_netif.h"
+#include "esp_log.h"
+#include "esp_event.h"
+#include "sdkconfig.h"
+#include "iface_info.h"
+#include "ppp_connect.h"
+#include "driver/uart.h"
+
+static const char *TAG = "ppp_connect_simple";
+
+static esp_err_t transmit(void *h, void *buffer, size_t len)
+{
+    ESP_LOG_BUFFER_HEXDUMP("ppp_connect_tx", buffer, len, ESP_LOG_VERBOSE);
+    uart_write_bytes(UART_NUM_1, buffer, len);
+    return ESP_OK;
+}
+
+static esp_netif_driver_ifconfig_t driver_cfg = {
+    .handle = (void *)1,    // singleton driver, just to != NULL
+    .transmit = transmit,
+};
+
+const esp_netif_driver_ifconfig_t *ppp_driver_cfg = &driver_cfg;
+
+#define BUF_SIZE (1024)
+#define CONNECTED "CONNECT 115200"
+
+void ppp_task(void *args)
+{
+    struct ppp_info_t *ppp_info = args;
+    uart_config_t uart_config = {
+        .baud_rate = 115200,
+        .data_bits = UART_DATA_8_BITS,
+        .parity    = UART_PARITY_DISABLE,
+        .stop_bits = UART_STOP_BITS_1,
+        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
+        .source_clk = UART_SCLK_DEFAULT,
+    };
+
+    QueueHandle_t event_queue;
+    ESP_ERROR_CHECK(uart_driver_install(UART_NUM_1, BUF_SIZE, 0, 16, &event_queue, 0));
+    ESP_ERROR_CHECK(uart_param_config(UART_NUM_1, &uart_config));
+    ESP_ERROR_CHECK(uart_set_pin(UART_NUM_1, CONFIG_EXAMPLE_PPP_UART_TX_PIN, CONFIG_EXAMPLE_PPP_UART_RX_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
+    ESP_ERROR_CHECK(uart_set_rx_timeout(UART_NUM_1, 1));
+
+    char *buffer = malloc(BUF_SIZE);
+    ppp_info->context = buffer;
+    const struct seq_t {
+        const char *cmd;
+        const char *expect;
+        bool allow_fail;
+    } init_sequence[] = {
+        { .cmd = "AT\r\n", .expect = "OK" },
+        { .cmd = "AT+CGDCONT=1,\"IP\",\"" CONFIG_EXAMPLE_MODEM_PPP_APN "\"\r\n", .expect = "OK" },
+        { .cmd = "ATD*99##\r\n", .expect = "CONNECT", .allow_fail = true },
+        { .cmd = "ATO\r\n", .expect = "CONNECT" },
+    };
+    int cmd_i = 0;
+    int retry = 0;
+    char *reply = buffer;
+    const int max_retries = 3;
+    uart_event_t event;
+    uart_write_bytes(UART_NUM_1, "+++", 3);
+    vTaskDelay(pdMS_TO_TICKS(1000));
+    while (retry < max_retries) {
+        ESP_LOGD(TAG, "Sending command: %s", init_sequence[cmd_i].cmd);
+        uart_write_bytes(UART_NUM_1, init_sequence[cmd_i].cmd, strlen(init_sequence[cmd_i].cmd));
+        xQueueReceive(event_queue, &event, pdMS_TO_TICKS(pdMS_TO_TICKS(1000)));
+        size_t len;
+        uart_get_buffered_data_len(UART_NUM_1, &len);
+        if (!len) {
+            continue;
+        }
+        len = uart_read_bytes(UART_NUM_1, reply, BUF_SIZE, 0);
+        ESP_LOGD(TAG, "Received: %.*s", len, reply);
+        if (strstr(reply, init_sequence[cmd_i].expect) || init_sequence[cmd_i].allow_fail) {
+            if (strstr(reply, CONNECTED)) { // are we connected already?
+                break;
+            }
+            cmd_i++;
+            continue;
+        }
+        ++retry;
+        vTaskDelay(pdMS_TO_TICKS(retry * 1000));
+    }
+    if (retry >= max_retries) {
+        ESP_LOGE(TAG, "Failed to perform initial modem connection");
+        vTaskDelete(NULL);
+    }
+    ESP_LOGI(TAG, "Modem configured correctly, switching to PPP protocol");
+    esp_event_handler_register(IP_EVENT, IP_EVENT_PPP_GOT_IP, esp_netif_action_connected, ppp_info->parent.netif);
+    esp_netif_action_start(ppp_info->parent.netif, 0, 0, 0);
+    while (!ppp_info->stop_task) {
+        xQueueReceive(event_queue, &event, pdMS_TO_TICKS(pdMS_TO_TICKS(1000)));
+        if (event.type == UART_DATA) {
+            size_t len;
+            uart_get_buffered_data_len(UART_NUM_1, &len);
+            if (len) {
+                len = uart_read_bytes(UART_NUM_1, buffer, BUF_SIZE, 0);
+                ESP_LOG_BUFFER_HEXDUMP("ppp_uart_recv", buffer, len, ESP_LOG_VERBOSE);
+                esp_netif_receive(ppp_info->parent.netif, buffer, len, NULL);
+            }
+        } else {
+            ESP_LOGW(TAG, "Received UART event: %d", event.type);
+        }
+    }
+}
+
+void ppp_destroy_context(struct ppp_info_t *ppp_info)
+{
+    char *buffer = ppp_info->context;
+    ppp_info->stop_task = true;
+    vTaskDelay(pdMS_TO_TICKS(1000));
+    free(buffer);
+    uart_driver_delete(UART_NUM_1);
+}