Subject: Re: Router Alert IPv4 Option
To: None <firstname.lastname@example.org>
From: None <email@example.com>
Date: 07/23/2001 09:28:45
>> hmmm, maybe this is exposing my ignorance about it :) nearly all the
>> Ipv4 options are manipulated in one way or another vis setsockopt &
>> getsockopt. What's required?
>Well, setscokopt would be a good way to have programs set the option.
setsockopt/getsockopt to enable/disable it, correct.
for example - you are a router.
a packet to address X comes in with router alert set.
you need to inspect it as well as forward it.
- which socket will the packet come up? raw, tcp, udp, whatever?
(note that in_laddr won't match as the address X is not on this
- will the packet get forwarded inside the kernel, or will it just
come up to the userland? i guess the latter, as otherwise you
won't have control over forwarding behavior.
- if you need to forward it, then, how do you really forward the
packet? how can you preserve the form of original packet and send
it out? ip_stripoptions() should have stripped the ip options,
there are header field reordering like ip_len (darren you know
we need to think about these gory details, yes.