Added GETTER method max_stations to wifi Radio objects, returning the

maximum number of stations that can be associated in AP mode

Added GETTER method stations_ap to wifi Radio objects, returning
a list of dicts with the MAC address, RSSI and IPV4 address of
each associated station. IPV4 addresses may be None if
the DHCP server hasn't yet assigned an address or if the station
hasn't requested one (for instance if it has a self-assigned or static
IP address, or isn't running TCP/IP).

Supports Espressif CPUS and the Raspberry Pi Pico W

The Pico W doesn't report RSSI values

Author: romkey

ports/espressif/common-hal/wifi/Radio.c

@@ -250,6 +250,47 @@ void common_hal_wifi_radio_stop_ap(wifi_radio_obj_t *self) {
     set_mode_ap(self, false);
 }
 
+mp_obj_t common_hal_wifi_radio_get_stations_ap(wifi_radio_obj_t *self) {
+    wifi_sta_list_t esp_sta_list;
+    esp_netif_pair_mac_ip_t mac_ip_pair[ESP_WIFI_MAX_CONN_NUM];
+    esp_err_t result;
+
+    result = esp_wifi_ap_get_sta_list(&esp_sta_list);
+    if (result == ESP_OK) {
+        for (int i = 0; i < esp_sta_list.num; i++) {
+            memcpy(mac_ip_pair[i].mac, esp_sta_list.sta[i].mac, MAC_ADDRESS_LENGTH);
+            mac_ip_pair[i].ip.addr = 0;
+        }
+
+        result = esp_netif_dhcps_get_clients_by_mac(self->ap_netif, esp_sta_list.num, mac_ip_pair);
+    }
+
+    if (!self->ap_mode || result != ESP_OK) {
+        mp_raise_RuntimeError(MP_ERROR_TEXT("Interface must be in access point mode"));
+    }
+
+    mp_obj_t mp_sta_list = mp_obj_new_list(0, NULL);
+    for (int i = 0; i < esp_sta_list.num; i++) {
+        mp_obj_dict_t *dict = MP_OBJ_TO_PTR(mp_obj_new_dict(3));
+
+        mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_mac), mp_obj_new_bytes(esp_sta_list.sta[i].mac, MAC_ADDRESS_LENGTH));
+        mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_rssi), MP_OBJ_NEW_SMALL_INT(esp_sta_list.sta[i].rssi));
+        if (mac_ip_pair[i].ip.addr) {
+            mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_ipv4_address), common_hal_ipaddress_new_ipv4address(mac_ip_pair[i].ip.addr));
+        } else {
+            mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_ipv4_address), mp_const_none);
+        }
+
+        mp_obj_list_append(mp_sta_list, dict);
+    }
+
+    return mp_sta_list;
+}
+
+mp_obj_t common_hal_wifi_radio_get_max_stations_ap(wifi_radio_obj_t *self) {
+    return MP_OBJ_NEW_SMALL_INT(ESP_WIFI_MAX_CONN_NUM);
+}
+
 wifi_radio_error_t common_hal_wifi_radio_connect(wifi_radio_obj_t *self, uint8_t *ssid, size_t ssid_len, uint8_t *password, size_t password_len, uint8_t channel, mp_float_t timeout, uint8_t *bssid, size_t bssid_len) {
     if (!common_hal_wifi_radio_get_enabled(self)) {
         mp_raise_RuntimeError(MP_ERROR_TEXT("wifi is not enabled"));

ports/raspberrypi/common-hal/wifi/Radio.c

@@ -244,6 +244,60 @@ void common_hal_wifi_radio_stop_ap(wifi_radio_obj_t *self) {
     bindings_cyw43_wifi_enforce_pm();
 }
 
+// There's no published API for the DHCP server to retrieve lease information
+// This code depends on undocumented internal structures and is likely to break in the future
+static uint32_t cyw43_dhcps_get_ip_addr(dhcp_server_t *dhcp_server, uint8_t *mac_address) {
+    for (int i = 0; i < DHCPS_MAX_IP; i++) {
+        if (memcmp(dhcp_server->lease[i].mac, mac_address, MAC_ADDRESS_LENGTH) == 0) {
+            return (dhcp_server->ip.addr & 0x00FFFFFF) + ((DHCPS_BASE_IP + i) << 24);
+        }
+    }
+
+    return 0;
+}
+
+mp_obj_t common_hal_wifi_radio_get_stations_ap(wifi_radio_obj_t *self) {
+    int max_stas;
+    int num_stas;
+
+    if (cyw43_tcpip_link_status(&cyw43_state, CYW43_ITF_AP) != CYW43_LINK_UP) {
+        mp_raise_RuntimeError(MP_ERROR_TEXT("Interface must be in access point mode"));
+    }
+
+    cyw43_wifi_ap_get_max_stas(&cyw43_state, &max_stas);
+
+    uint8_t macs[max_stas * MAC_ADDRESS_LENGTH];
+
+    cyw43_wifi_ap_get_stas(&cyw43_state, &num_stas, macs);
+
+    mp_obj_t mp_sta_list = mp_obj_new_list(0, NULL);
+    for (int i = 0; i < num_stas; i++) {
+        mp_obj_dict_t *dict = MP_OBJ_TO_PTR(mp_obj_new_dict(3));
+
+        mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_mac), mp_obj_new_bytes(&macs[i * MAC_ADDRESS_LENGTH], MAC_ADDRESS_LENGTH));
+        mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_rssi), mp_const_none);
+
+        uint32_t ipv4_addr = cyw43_dhcps_get_ip_addr(&cyw43_state.dhcp_server, &macs[i * MAC_ADDRESS_LENGTH]);
+        if (ipv4_addr) {
+            mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_ipv4_address), common_hal_ipaddress_new_ipv4address(ipv4_addr));
+        } else {
+            mp_obj_dict_store(dict, MP_OBJ_NEW_QSTR(MP_QSTR_ipv4_address), mp_const_none);
+        }
+
+        mp_obj_list_append(mp_sta_list, dict);
+    }
+
+    return mp_sta_list;
+}
+
+mp_obj_t common_hal_wifi_radio_get_max_stations_ap(wifi_radio_obj_t *self) {
+    int max_stas;
+
+    cyw43_wifi_ap_get_max_stas(&cyw43_state, &max_stas);
+
+    return MP_OBJ_NEW_SMALL_INT(max_stas);
+}
+
 static bool connection_unchanged(wifi_radio_obj_t *self, const uint8_t *ssid, size_t ssid_len) {
     if (cyw43_tcpip_link_status(&cyw43_state, CYW43_ITF_STA) != CYW43_LINK_UP) {
         return false;

shared-bindings/wifi/Radio.c

@@ -661,6 +661,34 @@ STATIC mp_obj_t wifi_radio_get_ap_info(mp_obj_t self) {
 }
 MP_DEFINE_CONST_FUN_OBJ_1(wifi_radio_get_ap_info_obj, wifi_radio_get_ap_info);
 
+//|     stations_ap: None
+//|     """In AP mode, returns list of objects (read-only)
+//|      mac: bytearray
+//|      rssi: int
+//|      ipv4_address: ipv4_address  (0.0.0.0 if station connected but no address assigned yet or self-assigned address)
+//|
+//|         .. note::
+//|
+//|             The raspberrypi port (RP2040 CYW43) does not report rssi, so the value will be None"""
+STATIC mp_obj_t wifi_radio_get_stations_ap(mp_obj_t self) {
+    return common_hal_wifi_radio_get_stations_ap(self);
+}
+
+MP_DEFINE_CONST_FUN_OBJ_1(wifi_radio_get_stations_ap_obj, wifi_radio_get_stations_ap);
+
+MP_PROPERTY_GETTER(wifi_radio_stations_ap_obj,
+    (mp_obj_t)&wifi_radio_get_stations_ap_obj);
+
+//|     max_stations_ap: Optional[Network]
+//|     """In AP mode, returns the maximum possible number of connected stations (read-only)"""
+STATIC mp_obj_t wifi_radio_get_max_stations_ap(mp_obj_t self) {
+    return common_hal_wifi_radio_get_max_stations_ap(self);
+}
+MP_DEFINE_CONST_FUN_OBJ_1(wifi_radio_get_max_stations_ap_obj, wifi_radio_get_max_stations_ap);
+
+MP_PROPERTY_GETTER(wifi_radio_max_stations_ap_obj,
+    (mp_obj_t)&wifi_radio_get_max_stations_ap_obj);
+
 //|     def start_dhcp(self) -> None:
 //|         """Starts the station DHCP client."""
 //|         ...
@@ -750,6 +778,8 @@ STATIC const mp_rom_map_elem_t wifi_radio_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_start_ap),    MP_ROM_PTR(&wifi_radio_start_ap_obj) },
     { MP_ROM_QSTR(MP_QSTR_stop_ap),    MP_ROM_PTR(&wifi_radio_stop_ap_obj) },
     { MP_ROM_QSTR(MP_QSTR_ap_active),   MP_ROM_PTR(&wifi_radio_ap_active_obj) },
+    { MP_ROM_QSTR(MP_QSTR_stations_ap),   MP_ROM_PTR(&wifi_radio_stations_ap_obj) },
+    { MP_ROM_QSTR(MP_QSTR_max_stations_ap),   MP_ROM_PTR(&wifi_radio_max_stations_ap_obj) },
 
     { MP_ROM_QSTR(MP_QSTR_start_dhcp),    MP_ROM_PTR(&wifi_radio_start_dhcp_client_obj) },
     { MP_ROM_QSTR(MP_QSTR_stop_dhcp),    MP_ROM_PTR(&wifi_radio_stop_dhcp_client_obj) },

shared-bindings/wifi/Radio.h

@@ -96,6 +96,8 @@ extern void common_hal_wifi_radio_stop_station(wifi_radio_obj_t *self);
 extern void common_hal_wifi_radio_start_ap(wifi_radio_obj_t *self, uint8_t *ssid, size_t ssid_len, uint8_t *password, size_t password_len, uint8_t channel, uint32_t authmode, uint8_t max_connections);
 extern void common_hal_wifi_radio_stop_ap(wifi_radio_obj_t *self);
 extern bool common_hal_wifi_radio_get_ap_active(wifi_radio_obj_t *self);
+extern mp_obj_t common_hal_wifi_radio_get_stations_ap(wifi_radio_obj_t *self);
+extern mp_obj_t common_hal_wifi_radio_get_max_stations_ap(wifi_radio_obj_t *self);
 
 extern void common_hal_wifi_radio_start_dhcp_client(wifi_radio_obj_t *self);
 extern void common_hal_wifi_radio_stop_dhcp_client(wifi_radio_obj_t *self);