Re: Re-routing packets via netfilter (ip_rt_bug)

From: Patrick McHardy
Date: Mon Apr 25 2005 - 10:48:20 EST

Herbert Xu wrote:
You'll still BUG if the destination is multicast/broadcast. I'm also
unsure whether ipt_REJECT isn't susceptible to the same problem.
Luckily ipt_MIRROR is no more :)

ipt_REJECT is fine, ip_route_input() is only used in NF_IP_FORWARD.
But you're right about multicast/broadcast still causing problems,
I'll have another look.

What are the issues with getting rid of the ip_route_input path

The only thing we gain over calling ip_route_output is the ability
to set the input device. But even that is just a fake derived from
the source address in a deterministic way. Therefore any effects
achievable through using ip_route_input can also be done by simply
reconfiguring the policy routing table to look at the local source
addresses instead of (or in conjunction with) the input device.

No, ip_route_me_harder() can be called for packets with non-local
source. ip_route_output_slow() rejects non-local source addresses,
so the only way to use them for policy routing is by using

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