[[ Bug 19598 ]] Allow the same local port to be used for multiple connections on all platforms

livecodemichael · livecodemichael · commit 259e4998c3d3 · 2017-05-09T17:26:57.000+01:00
On some platforms, the SO_REUSEADDR is insufficient to allow the same local port to be used for multiple connections. On these platforms, the SO_REUSEPORT option is now set. More info can be found here: http://stackoverflow.com/questions/14388706/socket-options-so-reuseaddr-and-so-reuseport-how-do-they-differ-do-they-mean-t/14388707#14388707 An assertion failure on socket read has also been fixed.
diff --git a/docs/notes/bugfix-19598.md b/docs/notes/bugfix-19598.md
@@ -0,0 +1 @@
+# Cannot accept and open sockets using the same local port on certain platforms
diff --git a/engine/src/opensslsocket.cpp b/engine/src/opensslsocket.cpp
@@ -720,6 +720,17 @@ bool MCS_connect_socket(MCSocket *p_socket, struct sockaddr_in *p_addr)
                 return false;
             }
 
+#ifdef SO_REUSEPORT
+            // some platforms also require the SO_REUSEPORT option to be set in order to use the same local port for multiple connections
+            t_port_reuse = 1;
+            if (setsockopt(p_socket->fd, SOL_SOCKET, SO_REUSEPORT, (const char *)&t_port_reuse, sizeof(t_port_reuse)) != 0)
+            {
+                p_socket->error = strclone("can't use the local port");
+                p_socket->doclose();
+                return false;
+            }
+#endif
+
             if (bind(p_socket->fd, (struct sockaddr *)&t_bind_addr, sizeof(struct sockaddr_in)) != 0)
             {
                 p_socket->error = strclone("can't bind to local host and port");
@@ -1133,6 +1144,15 @@ MCSocket *MCS_accept(uint2 port, MCObject *object, MCNameRef message, Boolean da
 	int on = 1;
 	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on));
 
+#ifdef SO_REUSEPORT
+    on = 1;
+    if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, (const char *)&on, sizeof(on)) != 0)
+    {
+        MCresult->sets("can't reuse port");
+        return NULL;
+    }
+#endif
+
 	mc_sockaddr_in_t addr;
 
 	memset((char *)&addr, 0, sizeof(addr));
@@ -1591,7 +1611,7 @@ void MCSocket::readsome()
 				MCAutoStringRef n;
 				MCNewAutoNameRef t_name;
 				/* UNCHECKED */ MCStringCreateMutable(strlen(t) + U2L, &n);
-				/* UNCHECKED */ MCStringAppendFormat(&n, "%s:%d", t, MCSwapInt16NetworkToHost(addr.sin_port));
+				/* UNCHECKED */ MCStringAppendFormat(*n, "%s:%d", t, MCSwapInt16NetworkToHost(addr.sin_port));
 				/* UNCHECKED */ MCNameCreate(*n, &t_name);
 				uindex_t index;
 				if (accepting && !IO_findsocket(*t_name, index))

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+# Cannot accept and open sockets using the same local port on certain platforms`