feat(lwip): Add DNS external hook in TCPIP context(v5.2)

components/lwip/Kconfig

@@ -1265,6 +1265,21 @@ menu "LWIP"
 
         endchoice
 
+        choice LWIP_HOOK_DNS_EXTERNAL_RESOLVE
+            prompt "DNS external resolve Hook"
+            default LWIP_HOOK_DNS_EXT_RESOLVE_NONE
+            help
+                Enables custom DNS resolve hook.
+                Setting this to "custom" provides hook's declaration
+                only and expects the application to implement it.
+
+            config LWIP_HOOK_DNS_EXT_RESOLVE_NONE
+                bool "No hook declared"
+            config LWIP_HOOK_DNS_EXT_RESOLVE_CUSTOM
+                bool "Custom implementation"
+
+        endchoice
+
         choice LWIP_HOOK_IP6_INPUT
             prompt "IPv6 packet input"
             depends on LWIP_IPV6

components/lwip/port/include/lwip_default_hooks.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2020-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -9,6 +9,7 @@
 #include "lwip/ip_addr.h"
 #include "lwip/arch.h"
 #include "lwip/err.h"
+#include "lwip/dns.h"
 #include "lwip/pbuf.h"
 #include "netif/dhcp_state.h"
 
@@ -55,6 +56,14 @@ int lwip_hook_netconn_external_resolve(const char *name, ip_addr_t *addr, u8_t a
 #define LWIP_HOOK_NETCONN_EXTERNAL_RESOLVE lwip_hook_netconn_external_resolve
 #endif /* CONFIG_LWIP_HOOK_NETCONN_EXTERNAL_RESOLVE... */
 
+#if defined(CONFIG_LWIP_HOOK_DNS_EXT_RESOLVE_CUSTOM)
+int lwip_hook_dns_external_resolve(const char *name, ip_addr_t *addr, dns_found_callback found, void *callback_arg,
+                                   u8_t addrtype, err_t *err);
+
+#define LWIP_HOOK_DNS_EXTERNAL_RESOLVE lwip_hook_dns_external_resolve
+#endif /* CONFIG_LWIP_HOOK_DNS_EXT_RESOLVE_CUSTOM */
+
+
 #if defined(CONFIG_LWIP_HOOK_IP6_INPUT_CUSTOM) || defined(CONFIG_LWIP_HOOK_IP6_INPUT_DEFAULT)
 int lwip_hook_ip6_input(struct pbuf *p, struct netif *inp);