feat(lwip): Hardcode NETIF_API=1 to support POSIX netif API

Author: david-cermak

components/lwip/CMakeLists.txt

@@ -100,11 +100,8 @@ if(CONFIG_LWIP_ENABLE)
         "port/hooks/lwip_default_hooks.c"
         "port/debug/lwip_debug.c"
         "port/sockets_ext.c"
-        "port/freertos/sys_arch.c")
-
-    if(CONFIG_LWIP_NETIF_API)
-        list(APPEND srcs "port/if_index.c")
-    endif()
+        "port/freertos/sys_arch.c"
+        "port/if_index.c")
 
     if(CONFIG_LWIP_PPP_SUPPORT)
         list(APPEND srcs

components/lwip/Kconfig

@@ -18,14 +18,6 @@ menu "LWIP"
             The default name this device will report to other devices on the network.
             Could be updated at runtime with esp_netif_set_hostname()
 
-    config LWIP_NETIF_API
-        bool "Enable usage of standard POSIX APIs in LWIP"
-        default n
-        help
-            If this feature is enabled, standard POSIX APIs: if_indextoname(), if_nametoindex()
-            could be used to convert network interface index to name
-            instead of IDF specific esp-netif APIs (such as esp_netif_get_netif_impl_name())
-
     config LWIP_TCPIP_TASK_PRIO
         int "LWIP TCP/IP Task Priority"
         default 18

components/lwip/port/include/lwipopts.h

@@ -709,18 +709,11 @@ static inline uint32_t timeout_from_offered(uint32_t lease, uint32_t min)
  * LWIP_DHCP_DISCOVER_ADD_HOSTNAME==1: include hostname opt in discover packets.
  * If the hostname is not set in the DISCOVER packet, then some servers might issue
  * an OFFER with hostname configured and consequently reject the REQUEST with any other hostname.
+ * LWIP_NETIF_API==1: Support netif APIs (if_nametoindex and if_indextoname)
  */
 #define LWIP_NETIF_HOSTNAME             1
 #define LWIP_DHCP_DISCOVER_ADD_HOSTNAME 1
-
-/**
-  * LWIP_NETIF_API==1: Support netif api (in netifapi.c)
- */
-#ifdef CONFIG_LWIP_NETIF_API
 #define LWIP_NETIF_API                  1
-#else
-#define LWIP_NETIF_API                  0
-#endif
 
 /**
  * LWIP_NETIF_STATUS_CALLBACK==1: Support a callback function whenever an interface

components/lwip/port/linux/include/net/if.h

@@ -1,6 +1,26 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 #pragma once
+
+// Need to provide declarations of if_nametoindex and if_indextoname functions
+// as we don't want to bring lwip specific defines
+// (since we're on linux target and likely using linux tcp/ip stack)
+
+/**
+ * @brief Get the interface index for the given interface name.
+ * @param ifname The interface name.
+ * @return The interface index.
+ */
+unsigned int if_nametoindex(const char *ifname);
+
+/**
+ * @brief Get the interface name for the given interface index.
+ *
+ * @param ifindex   The interface index.
+ * @param ifname    The buffer to store the interface name.
+ * @return char*    The interface name.
+ */
+char *if_indextoname(unsigned int ifindex, char *ifname);