From d16c422b118846221c6ec2af06954da722d5d4f4 Mon Sep 17 00:00:00 2001
From: David Cermak <cermak@espressif.com>
Date: Mon, 2 Jan 2023 16:49:37 +0100
Subject: [PATCH] esp_netif: Allow set_dns_info() for PPP netifs

esp_netif_set_dns_info() was available only for standard interfaces, not
for Point to point types (PPP, SLIP), but it should be normally
supported. Moreover DNS servers are global in lwip, so it doesn't really
depend on type of the interface.

Also added some minor fixes to the esp_netif_get_dns_info() to allow for
NULL parameters (as it's a public API) and hardcode the IPv4 type in
case of DHCP server capable interface.

Updated logs and added error checks to the original API, before we
launch the lwIP counterpart.

Closes https://github.com/espressif/esp-idf/issues/8648
---
 components/esp_netif/lwip/esp_netif_lwip.c | 59 +++++++++-------------
 1 file changed, 23 insertions(+), 36 deletions(-)

diff --git a/components/esp_netif/lwip/esp_netif_lwip.c b/components/esp_netif/lwip/esp_netif_lwip.c
index da38687314..dbc78b34ff 100644
--- a/components/esp_netif/lwip/esp_netif_lwip.c
+++ b/components/esp_netif/lwip/esp_netif_lwip.c
@@ -1692,23 +1692,7 @@ static esp_err_t esp_netif_set_dns_info_api(esp_netif_api_msg_t *msg)
     esp_netif_dns_type_t type = dns_param->dns_type;
     esp_netif_dns_info_t *dns = dns_param->dns_info;
 
-    ESP_LOGD(TAG, "%s esp_netif:%p", __func__, esp_netif);
-
-    if (esp_netif == NULL) {
-        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
-    }
-
-    if (!dns) {
-        ESP_LOGD(TAG, "set dns null dns");
-        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
-    }
-
-    if (ip4_addr_isany_val(dns->ip.u_addr.ip4)) {
-        ESP_LOGD(TAG, "set dns invalid dns");
-        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
-    }
-
-    ESP_LOGD(TAG, "set dns if=%p type=%d dns=%x", esp_netif, type, dns->ip.u_addr.ip4.addr);
+    ESP_LOGD(TAG, "esp_netif_set_dns_info: if=%p type=%d dns=%x", esp_netif, type, dns->ip.u_addr.ip4.addr);
 
     ip_addr_t *lwip_ip = (ip_addr_t*)&dns->ip;
 #if CONFIG_LWIP_IPV6 && LWIP_IPV4
@@ -1737,9 +1721,20 @@ static esp_err_t esp_netif_set_dns_info_api(esp_netif_api_msg_t *msg)
 
 esp_err_t esp_netif_set_dns_info(esp_netif_t *esp_netif, esp_netif_dns_type_t type, esp_netif_dns_info_t *dns)
 {
-    if (_IS_NETIF_ANY_POINT2POINT_TYPE(esp_netif)) {
-        return ESP_ERR_NOT_SUPPORTED;
+    if (esp_netif == NULL) {
+        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
     }
+
+    if (dns == NULL) {
+        ESP_LOGD(TAG, "set dns null dns");
+        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
+    }
+
+    if (ip4_addr_isany_val(dns->ip.u_addr.ip4)) {
+        ESP_LOGD(TAG, "set dns invalid dns");
+        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
+    }
+
     esp_netif_dns_param_t dns_param = {
         .dns_type = type,
         .dns_info = dns
@@ -1754,18 +1749,14 @@ static esp_err_t esp_netif_get_dns_info_api(esp_netif_api_msg_t *msg)
     esp_netif_dns_type_t type = dns_param->dns_type;
     esp_netif_dns_info_t *dns = dns_param->dns_info;
 
-    ESP_LOGD(TAG, "%s esp_netif:%p", __func__, esp_netif);
-
-    if (!dns) {
-        ESP_LOGE(TAG, "%s: dns_info cannot be NULL", __func__);
-        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
-    }
+    ESP_LOGD(TAG, "esp_netif_get_dns_info: esp_netif=%p type=%d", esp_netif, type);
 
     if (esp_netif->flags & ESP_NETIF_DHCP_SERVER) {
 #if ESP_DHCPS
         ip4_addr_t dns_ip;
         dhcps_dns_getserver(esp_netif->dhcps, &dns_ip);
         memcpy(&dns->ip.u_addr.ip4, &dns_ip, sizeof(ip4_addr_t));
+        dns->ip.type = ESP_IPADDR_TYPE_V4;
 #else
         LOG_NETIF_DISABLED_AND_DO("DHCP Server", return ESP_ERR_NOT_SUPPORTED);
 #endif
@@ -1782,17 +1773,13 @@ static esp_err_t esp_netif_get_dns_info_api(esp_netif_api_msg_t *msg)
 
 esp_err_t esp_netif_get_dns_info(esp_netif_t *esp_netif, esp_netif_dns_type_t type, esp_netif_dns_info_t *dns)
 {
-    if (_IS_NETIF_ANY_POINT2POINT_TYPE(esp_netif)) {
-        const ip_addr_t *dns_ip = dns_getserver(type);
-        if (dns_ip == IP_ADDR_ANY) {
-            return ESP_ERR_ESP_NETIF_DNS_NOT_CONFIGURED;
-        }
-#if CONFIG_LWIP_IPV6
-        memcpy(&dns->ip.u_addr.ip4, &dns_ip->u_addr.ip4, sizeof(ip4_addr_t));
-#else
-        memcpy(&dns->ip.u_addr.ip4, &dns_ip->addr, sizeof(ip4_addr_t));
-#endif
-        return ESP_OK;
+    if (esp_netif == NULL) {
+        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
+    }
+
+    if (dns == NULL) {
+        ESP_LOGE(TAG, "%s: dns_info cannot be NULL", __func__);
+        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
     }
 
     esp_netif_dns_param_t dns_param = {