allow enabling socket API without (public) netconn API - netconn API is still used by sockets, but keeping it private (static) should allow better compiler optimizations

src/api/sockets.c

@@ -59,6 +59,18 @@
 
 #include <string.h>
 
+/* If the netconn API is not required publicly, then we include the necessary
+   files here to get the implementation */
+#if !LWIP_NETCONN
+#undef LWIP_NETCONN
+#define LWIP_NETCONN 1
+#include "api_msg.c"
+#include "api_lib.c"
+#include "netbuf.c"
+#undef LWIP_NETCONN
+#define LWIP_NETCONN 0
+#endif
+
 #define IP4ADDR_PORT_TO_SOCKADDR(sin, ipXaddr, port) do { \
       (sin)->sin_len = sizeof(struct sockaddr_in); \
       (sin)->sin_family = AF_INET; \

src/api/tcpip.c

@@ -99,12 +99,12 @@ tcpip_thread(void *arg)
       continue;
     }
     switch (msg->type) {
-#if LWIP_NETCONN
+#if LWIP_NETCONN || LWIP_SOCKET
     case TCPIP_MSG_API:
       LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: API message %p\n", (void *)msg));
       msg->msg.apimsg->function(&(msg->msg.apimsg->msg));
       break;
-#endif /* LWIP_NETCONN */
+#endif /* LWIP_NETCONN || LWIP_SOCKET */
 
 #if !LWIP_TCPIP_CORE_LOCKING_INPUT
     case TCPIP_MSG_INPKT:
@@ -316,7 +316,7 @@ tcpip_untimeout(sys_timeout_handler h, void *arg)
 }
 #endif /* LWIP_TCPIP_TIMEOUT */
 
-#if LWIP_NETCONN
+#if LWIP_NETCONN || LWIP_SOCKET
 /**
  * Call the lower part of a netconn_* function
  * This function is then running in the thread context
@@ -351,7 +351,7 @@ tcpip_apimsg(struct api_msg *apimsg)
   return ERR_VAL;
 }
 
-#endif /* LWIP_NETCONN */
+#endif /* LWIP_NETCONN || LWIP_SOCKET */
 
 #if LWIP_NETIF_API
 #if !LWIP_TCPIP_CORE_LOCKING