On Sun, 16 Mar 2008, Phil Blundell wrote:

> It seems that recent versions of libc-ares have tolerably good support
> for IPv6 lookups. But a couple of curl changes are needed to make this
> work properly:
>
> - ares doesn't support IP literals, so Curl_addrinfo() needs to detect
> this and handle the conversion itself, just as for IPv4
>
> - Curl_he2ai is currently hardcoded for AF_INET addresses. It needs to
> be able to convert both IPv4 and IPv6.
>
> I've attached a patch that works for me.

Thanks! This is something we've been wanting...

First, you should try building after having done "./configure --enable-debug"
and gcc will point out a few nits in your patch. They're easily fixed though.

Some other concerns about the patch:

o - Using getaddrinfo to check for and convert an IP6-only address to a struct
     addrinfo result. Is that really an effective way? We do have a inet_pton()
     function in use in the code already?

o - I'm a bit concerned about the returning of the result directly from what
     getaddrinfo() returns as that requires a call to freeaddrinfo() while data
     that c-ares returns will not. I sense that there's either a memory leak or
     a memory mixup somewhere in there. Did you valgrind your tests?

o - The uncondtional use of "struct sockaddr_in6" in the ip4-code will cause
     grief on systems that truly have no ipv6 support whatsoever. It needs some
     crafty #ifdefs or other magic to make it build on such systems as well.

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