[MPlayer-dev-eng] [PATCH] Don't try to connect to AF_INET address with AF_INET6

[Aaron Plattner]

When _BSD_SOURCE isn't defined, gethostbyname2() isn't available.  This causes
HAVE_GETHOSTBYNAME2 to be undefined, making connect2Server_with_af fall back to
gethostbyname(), which always returns an AF_INET address.

Without a check against hp->h_addrtype, this causes the memcpy to stuff the 4
bytes of the AF_INET address into the beginning of the AF_INET6 address field:

 Playing http://www.facebook.com/.
 Resolving www.facebook.com for AF_INET6...
 Connecting to server www.facebook.com[45ab:ed14::]: 80...

 Failed to connect to server with AF_INET6
 Resolving www.facebook.com for AF_INET...
 Connecting to server www.facebook.com[69.171.237.20]: 80...

On systems with real IPv6 connections, this first connection attempt to a bogus
address can take a very long time to time out.

To address this problem, bail out immediately if gethostbyname() returns an
address from an incompatible family.  The caller will immediately fallback to
AF_INET.


This patch is against SVN r36350.


Index: stream/tcp.c
===================================================================
--- stream/tcp.c	(revision 36350)
+++ stream/tcp.c	(working copy)
@@ -160,6 +160,8 @@
 			return TCP_ERROR_FATAL;
 		}
 
+		if (af != hp->h_addrtype) return TCP_ERROR_FATAL;
+
 		memcpy( our_s_addr, hp->h_addr_list[0], hp->h_length );
 	}
 #if HAVE_WINSOCK2_H