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

[Erik Auerswald]

Hi Aaron,

On 07/06/2013 03:19 AM, Aaron Plattner wrote:
> 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.

I have seen this problem for some time, but have not investigated it yet.

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

Great! This patch works for me. No more long timeouts for wrong IPv6 
addresses. :-)

Tested-by Erik Auerswald <auerswal at unix-ag.uni-kl.de>

@MPlayer devs: please accept this patch, it is helpful.

Thanks,
Erik