ESP Thread BR in Wi-Fi AP mode (TZ-1397)

[walker2398]

Checklist

• Checked the issue tracker for similar issues to ensure this is not a duplicate.
• Described the feature in detail and justified the reason for the request.
• Provided specific use cases and examples.

Feature description

As mentioned in this post,Raspberry pies can build a thread BR in its AP mode.Can ESP Thread BR make this work?

Use cases

In my use case, I want to allow user to build a thread network with the ESP Thread BR only,without any outer AP. So connecting to the board by its Wi-Fi AP mode is a must.

Alternatives

Maybe using bluetooth communication might work?

Additional context

No response

[chshu]

@walker2398 In your use case, will the ESP Thread BR connect to Ethernet? Or is it a purely local network where only Thread devices (connected to the BR's Thread network) and Wi-Fi devices (connected to the BR's AP) can communicate with each other, with no access from external devices?

[walker2398]

@chshu 原谅我英语不好，只能写中文。
是的，我的Thread网络应该不连接到外网，只是一个本地网络，手机通过连接Border Router控制网络内设备。

[chshu]

好的，我们看一下这个场景怎么支持，有进展会及时给你更新。

[gytxxsy]

@walker2398 For a border router using Wi-Fi AP mode, the underlying principle is similar to that of a border router using Wi-Fi station mode. However, our current extension command does not support enabling Wi-Fi AP mode directly on the border router. Therefore, you will need to follow the steps below:

1. Implement a function to start the Wi-Fi AP, and ensure that you have registered an event handler to add the IPv6 link-local address. An example is provided below:

#include "esp_netif_types.h"
#include "esp_netif_defaults.h"
#define SSIDKEY "ssid"
#define PASSWORDKEY "password"
#define SSIDMAXLEN 32
#define PASSWORDMAXLEN 64
#define TAG "esp_border_router"

static void esp_ot_wifi_ap_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
{
    if (event_id == WIFI_EVENT_AP_START) {
        ESP_LOGI(TAG, "wifi ap start");
        if (esp_netif_create_ip6_linklocal(esp_netif_get_handle_from_ifkey("WIFI_AP_DEF")) != ESP_OK) {
            ESP_LOGE(TAG, "Fail to create a linklocal addr for wifi ap");
        }
    } if (event_id == WIFI_EVENT_AP_STACONNECTED) {
        wifi_event_ap_staconnected_t *event = (wifi_event_ap_staconnected_t *)event_data;
        ESP_LOGI(TAG, "station " MACSTR " join, AID=%d", MAC2STR(event->mac), event->aid);
    } else if (event_id == WIFI_EVENT_AP_STADISCONNECTED) {
        wifi_event_ap_stadisconnected_t *event = (wifi_event_ap_stadisconnected_t *)event_data;
        ESP_LOGI(TAG, "station " MACSTR " leave, AID=%d, reason=%d", MAC2STR(event->mac), event->aid,
                 event->reason);
    }
}

esp_err_t esp_ot_wifi_ap_start(const char *ssid, const char *password)
{
    esp_netif_inherent_config_t ap_config_base = ESP_NETIF_INHERENT_DEFAULT_WIFI_AP();
    ap_config_base.flags |= ESP_NETIF_FLAG_IPV6_AUTOCONFIG_ENABLED;
    esp_netif_config_t netif_cfg = {
        .base = &ap_config_base,
        .driver = NULL,
        .stack = ESP_NETIF_NETSTACK_DEFAULT_WIFI_AP,
    };
    esp_netif_t *netif = esp_netif_new(&netif_cfg);
    assert(netif);
    ESP_ERROR_CHECK(esp_netif_attach_wifi_ap(netif));
    ESP_ERROR_CHECK(esp_wifi_set_default_wifi_ap_handlers());

    wifi_init_config_t wifi_cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&wifi_cfg));

    ESP_ERROR_CHECK(
        esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &esp_ot_wifi_ap_event_handler, NULL, NULL));
    wifi_config_t wifi_config = {
        .ap =
            {
                .ssid = "",
                .ssid_len = 0,
                .channel = 1,
                .password = "",
                .max_connection = 4,
#ifdef CONFIG_ESP_WIFI_SOFTAP_SAE_SUPPORT
                .authmode = WIFI_AUTH_WPA3_PSK,
                .sae_pwe_h2e = WPA3_SAE_PWE_BOTH,
#else /* CONFIG_ESP_WIFI_SOFTAP_SAE_SUPPORT */
                .authmode = WIFI_AUTH_WPA2_PSK,
#endif
                .pmf_cfg =
                    {
                        .required = true,
                    },
            },
    };
    uint8_t ssid_len = strnlen(ssid, SSIDMAXLEN);
    uint8_t password_len = strnlen(password, PASSWORDMAXLEN);
    if (ssid_len < SSIDMAXLEN && password_len < PASSWORDMAXLEN) {
        wifi_config.ap.ssid_len = ssid_len;
        memcpy(wifi_config.sta.ssid, (void *)ssid, ssid_len + 1);
        memcpy(wifi_config.sta.password, (void *)password, password_len + 1);
    } else {
        ESP_LOGE(TAG, "Invalid ssid or password");
        return ESP_ERR_INVALID_ARG;
    }
    if (password_len == 0) {
        wifi_config.ap.authmode = WIFI_AUTH_OPEN;
    }

    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_AP, &wifi_config));
    ESP_ERROR_CHECK(esp_wifi_start());

    return ESP_OK;
}

2. After calling esp_ot_wifi_ap_start to start the Wi-Fi AP, you need to set the Wi-Fi AP netif as the backbone netif, and then initialize the border router. For example:：

ESP_ERROR_CHECK(esp_ot_wifi_ap_start("OTBRAP", "espressif"));
esp_openthread_lock_acquire(portMAX_DELAY);
esp_openthread_set_backbone_netif(esp_netif_get_handle_from_ifkey("WIFI_AP_DEF"));
if (esp_openthread_border_router_init() != ESP_OK) {
    ESP_LOGE(OT_EXT_CLI_TAG, "Fail to initialize border router");
}
esp_openthread_lock_release();

3. Next, enable the Thread network. You can use the configured SSID and password to connect the host device to the Border Router, allowing it to communicate with devices within the Thread network.

[walker2398]

这太酷了！感谢你们的付出。