SO_REUSEADDR / SO_REUSE is implemented and safe to use

src/core/init.c

@@ -206,11 +206,6 @@
 #ifdef ETHARP_ALWAYS_INSERT
   #error "ETHARP_ALWAYS_INSERT option is deprecated. Remove it from your lwipopts.h."
 #endif
-#if SO_REUSE
-/* I removed the lot since this was an ugly hack. It broke the raw-API.
-   It also came with many ugly goto's, Christiaan Simons. */
-  #error "SO_REUSE currently unavailable, this was a hack"
-#endif
 
 #ifdef LWIP_DEBUG
 static void
@@ -237,6 +232,29 @@ lwip_sanity_check(void)
   if (TCP_WND < TCP_MSS)
     LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: TCP_WND is smaller than MSS\n"));
 #endif /* LWIP_TCP */
+#if LWIP_SOCKET
+  /* Check that the SO_* socket options and SOF_* lwIP-internal flags match */
+  if (SO_DEBUG != SOF_DEBUG)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_DEBUG != SOF_DEBUG\n"));
+  if (SO_ACCEPTCONN != SOF_ACCEPTCONN)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_ACCEPTCONN != SOF_ACCEPTCONN\n"));
+  if (SO_REUSEADDR != SOF_REUSEADDR)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_REUSEADDR != SOF_REUSEADDR\n"));
+  if (SO_KEEPALIVE != SOF_KEEPALIVE)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_KEEPALIVE != SOF_KEEPALIVE\n"));
+  if (SO_DONTROUTE != SOF_DONTROUTE)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_DONTROUTE != SOF_DONTROUTE\n"));
+  if (SO_BROADCAST != SOF_BROADCAST)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_BROADCAST != SOF_BROADCAST\n"));
+  /*if (SO_USELOOPBACK != SOF_USELOOPBACK)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_USELOOPBACK != SOF_USELOOPBACK\n"));*/
+  if (SO_LINGER != SOF_LINGER)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_LINGER != SOF_LINGER\n"));
+  if (SO_OOBINLINE != SOF_OOBINLINE)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_OOBINLINE != SOF_OOBINLINE\n"));
+  /*if (SO_REUSEPORT != SOF_REUSEPORT)
+    LWIP_PLATFORM_DIAG(("lwip_sanity_check: WARNING: SO_REUSEPORT != SOF_REUSEPORT\n"));*/
+#endif /* LWIP_SOCKET */
 }
 #else  /* LWIP_DEBUG */
 #define lwip_sanity_check()

src/include/lwip/sockets.h

@@ -72,11 +72,11 @@ struct sockaddr {
 #define SOCK_RAW        3
 
 /*
- * Option flags per-socket. These must match the SOF_ flags in ip.h!
+ * Option flags per-socket. These must match the SOF_ flags in ip.h (checked in init.c)
  */
 #define  SO_DEBUG       0x0001 /* Unimplemented: turn on debugging info recording */
 #define  SO_ACCEPTCONN  0x0002 /* socket has had listen() */
-#define  SO_REUSEADDR   0x0004 /* Unimplemented: allow local address reuse */
+#define  SO_REUSEADDR   0x0004 /* Allow local address reuse */
 #define  SO_KEEPALIVE   0x0008 /* keep connections alive */
 #define  SO_DONTROUTE   0x0010 /* Unimplemented: just use interface addresses */
 #define  SO_BROADCAST   0x0020 /* permit to send and to receive broadcast messages (see IP_SOF_BROADCAST option) */