(usagi-users 02112) Re: multiproto bind() ?

[Abdul Basit <basit@xxxxxxxx>]

i thought the same, but unaware of such a macro,
thanks for identifying the macro though

definately this helps.

-- basit

On Sun, 19 Jan 2003, Eva M. Castro wrote:

> Abdul Basit wrote:
>
> > i want to distinguish between clients coming to ipv4 or ipv6
> > and print client address ? if i would get sa_family correct
> > i can switch(family) { and case for AF_INET and AF_INET6 and
> > use inet_ntop to print address ? but i am getting same family
> > always (28c/bsd and 10c/linux --> AF_INET6)
> >
> > any hints?
>
> When an IPv4 client connects to your server, the connection is established
> using an IPv4-mapped IPv6 address, for instance, if your IPv4 client
> is running at host using a.b.c.d IPv4 address, the IPv4-mapped IPv6
> address will be:
> ::FFFF:a.b.c.d
>
> Then, your IPv6 server will always use IPv6 addresses,
> IPv6 addresses when connections come from IPv6 hosts and
> IPv4-mapped IPv6 addresses when connections come from IPv4 hosts.
> This is the reason you always print AF_INET6.
>
> You can see how it works:
> http://jungla.dit.upm.es/~ecastro/IPv6-web/ipv6.html
> in the figure "IPv6 server on dual stack".
>
> There is a macro definition to check if an address is IPv4-mapped IPv6
> address:
>
> IN6_IS_ADDR_V4MAPPED
>
> Using this macro you can check if the client connections come from
> IPv4 or IPv6 host.
>
> I hope it helps,
>
> eva
>
>
>
>