On Thursday 20 November 2008 14:00:11 Randall Stewart wrote:
> On Nov 19, 2008, at 5:33 PM, Julian Elischer wrote:
> >> Its not new, its the same ip header..
> >> Its just you go into the mbuf chain and take out
> >> the udp header...
> > well you can't do that at the socket buffer becasue you've discarded
> > the IP header. It may not even be in the mbufs you have. (though it's
> > unlikely). After you've processed the UDP part the IP part is gone so
> > you'd need to intercept the packet way earlier and then do your
> > own UDP processing, (or maybe attach the IP header onto it with a
> > tag).
> One would definitely have to do some work in udp_input() not a lot from
> what I can tell... but it would take some work.
> Maybe good course is to use the socket(9) stuff, but add an option
> that can set a "by-pass function" if the socket is udp... right
> after you establish the INP the packet goes to, if the function is
> set, you engage the bypass...
This sounds reasonable. One would only have to replace calls to udp_append in
udp_input with the by-pass function et voila. Should be clean enough. There
might be some problems with holding the socket lock, though.
For the record, I don't like all the UDP-tunneling madness either, but it
seems that we are stuck with it ... so we should at least try to come up with
a somewhat reasonable implementation for this hackery.
/"\ Best regards, | firstname.lastname@example.org
\ / Max Laier | ICQ #67774661
X http://pf4freebsd.love2party.net/ | mlaier@EFnet
/ \ ASCII Ribbon Campaign | Against HTML Mail and News