Enable DNS info

Author: astrobokonon

ports/esp32s2/common-hal/wifi/Radio.c

@@ -192,6 +192,20 @@ mp_obj_t common_hal_wifi_radio_get_ipv4_address(wifi_radio_obj_t *self) {
     return common_hal_ipaddress_new_ipv4address(self->ip_info.ip.addr);
 }
 
+mp_obj_t common_hal_wifi_radio_get_ipv4_dns(wifi_radio_obj_t *self) {
+    if (!esp_netif_is_netif_up(self->netif)) {
+        return mp_const_none;
+    }
+
+    esp_netif_get_dns_info(self->netif, ESP_NETIF_DNS_MAIN, &self->dns_info);
+
+    // dns_info is of type esp_netif_dns_info_t, which is just ever so slightly
+    // different than esp_netif_ip_info_t used for
+    // common_hal_wifi_radio_get_ipv4_address (includes both ipv4 and 6),
+    // so some extra jumping is required to get to the actual address
+    return common_hal_ipaddress_new_ipv4address(self->dns_info.ip.u_addr.ip4.addr);
+}
+
 mp_int_t common_hal_wifi_radio_ping(wifi_radio_obj_t *self, mp_obj_t ip_address, mp_float_t timeout) {
     esp_ping_config_t ping_config = ESP_PING_DEFAULT_CONFIG();
     ipaddress_ipaddress_to_esp_idf(ip_address, &ping_config.target_addr);

ports/esp32s2/common-hal/wifi/Radio.h

@@ -48,6 +48,7 @@ typedef struct {
     wifi_config_t sta_config;
     wifi_ap_record_t ap_info;
     esp_netif_ip_info_t ip_info;
+    esp_netif_dns_info_t dns_info;
     esp_netif_t *netif;
     bool started;
     bool ap_mode;

shared-bindings/wifi/Radio.c

@@ -227,6 +227,22 @@ const mp_obj_property_t wifi_radio_ipv4_address_obj = {
                (mp_obj_t)&mp_const_none_obj },
 };
 
+//|     ipv4_dns: Optional[ipaddress.IPv4Address]
+//|     """IP v4 Address of the DNS server in use when connected to an access point. None otherwise."""
+//|
+STATIC mp_obj_t wifi_radio_get_ipv4_dns(mp_obj_t self) {
+    return common_hal_wifi_radio_get_ipv4_dns(self);
+
+}
+MP_DEFINE_CONST_FUN_OBJ_1(wifi_radio_get_ipv4_dns_obj, wifi_radio_get_ipv4_dns);
+
+const mp_obj_property_t wifi_radio_ipv4_dns_obj = {
+    .base.type = &mp_type_property,
+    .proxy = { (mp_obj_t)&wifi_radio_get_ipv4_dns_obj,
+               (mp_obj_t)&mp_const_none_obj,
+               (mp_obj_t)&mp_const_none_obj },
+};
+
 //|     def ping(self, ip, *, timeout: float = 0.5) -> float:
 //|         """Ping an IP to test connectivity. Returns echo time in seconds.
 //|            Returns None when it times out."""
@@ -268,6 +284,7 @@ STATIC const mp_rom_map_elem_t wifi_radio_locals_dict_table[] = {
     // { MP_ROM_QSTR(MP_QSTR_connect_to_enterprise),    MP_ROM_PTR(&wifi_radio_connect_to_enterprise_obj) },
 
     { MP_ROM_QSTR(MP_QSTR_ap_rssi),    MP_ROM_PTR(&wifi_radio_ap_rssi_obj) },
+    { MP_ROM_QSTR(MP_QSTR_ipv4_dns),    MP_ROM_PTR(&wifi_radio_ipv4_dns_obj) },
     { MP_ROM_QSTR(MP_QSTR_ipv4_gateway),    MP_ROM_PTR(&wifi_radio_ipv4_gateway_obj) },
     { MP_ROM_QSTR(MP_QSTR_ipv4_subnet),    MP_ROM_PTR(&wifi_radio_ipv4_subnet_obj) },
     { MP_ROM_QSTR(MP_QSTR_ipv4_address),    MP_ROM_PTR(&wifi_radio_ipv4_address_obj) },

shared-bindings/wifi/Radio.h

@@ -54,6 +54,7 @@ extern void common_hal_wifi_radio_stop_scanning_networks(wifi_radio_obj_t *self)
 extern 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);
 
 extern mp_obj_t common_hal_wifi_radio_get_ap_rssi(wifi_radio_obj_t *self);
+extern mp_obj_t common_hal_wifi_radio_get_ipv4_dns(wifi_radio_obj_t *self);
 extern mp_obj_t common_hal_wifi_radio_get_ipv4_gateway(wifi_radio_obj_t *self);
 extern mp_obj_t common_hal_wifi_radio_get_ipv4_subnet(wifi_radio_obj_t *self);
 extern mp_obj_t common_hal_wifi_radio_get_ipv4_address(wifi_radio_obj_t *self);