[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [lwip-users] add ICMP Destination unreachable
From: |
Leon Woestenberg |
Subject: |
Re: [lwip-users] add ICMP Destination unreachable |
Date: |
Fri, 28 Jan 2005 21:07:53 +0100 |
User-agent: |
Mozilla Thunderbird 1.0 (Windows/20041206) |
Hello Andreas,
Andreas Becker wrote:
Hi all,
I'm thinking about to extend LWIP with the processing of a
ICMP-destination-unreachable Message.
Just to make sure we understand: you mean handling incoming
ICMP destination unreachable messages?
I would really investigate how the BSD stack handles this.
My first idea would be to have a route cache (identical to
the ARP cache) that holds IP addresses that got ICMP
unreachable, with entries like these:
<dest address>,<dest port>,<flags>
flags = { dest_unreachable, port_unreachable }
<dest port> only is used if (flags & port_unreachable)
I was already thinking about how to add outgoing ICMP
dest unreachable messages BTW.
I dislike implementing callbacks into user space for things that
the stack should handle, btw. This burdens a lot of complexity
on the application, whereas unreachable destinations can be
as simple as a return code indicating so.
Regards,
Leon.