Re: [Sks-devel] Patch (partial): IPv6 support (in progress)

[Phil Pennock]

On 2009-03-02 at 12:55 +0000, Kim Minh Kaplan wrote:
> it is funny that you send this as I was just doing something very
> similar this weekend.  Here is what I did.  I am still experimenting
> with what actually works, what does not and trying to find what I broke.
> I'll have a look at the way you did it when I have some time, probably
> wednesday.

You're using IPv6-mapped IPv4 addresses for IPv4 handling.  This will
break on systems where this is disabled by default; eg, FreeBSD with
net.inet6.ip6.v6only set to 1, as it is by default.

To undo this, the program neets to setsockopt IPV6_V6ONLY at level
IPPROTO_IPV6.  Looking through unix.mli on my system, it looks as though
O'Caml only supports setting some common options at level SOL_SOCKET.

It seems that using !Unix.setsockopt_int you do have access to set the
option (looking at O'Caml otherlibs/unix/sockopt.c) and the value of
IPPROTO_IPV6 is fixed, but the value of IPV6_V6ONLY is, AIUI,
OS-dependent.

Then too there's the fact that I need to bind to specific IP addresses
on my system, instead of 0.0.0.0 so just switching to :: would be bad; I
use recon_address in sksconf and needed some way to set a specific IPv4
address and a specific IPv6 address, so multiple sockets it became.

-Phil

pgpqvrWBchFnH.pgp
Description: PGP signature