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Date: Tue, 27 Apr 2004 18:09:01 +0200
From: Mark Santcroos <marks@ripe.net>
To: net@freebsd.org
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Subject: udp checksum on raw sockets
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* I'm sending UDP packets on a raw socket.

* iphdr->ip_src.s_addr = INADDR_ANY;
  So I don't know the IP address that will be used as src address.
  So as far as I can see, I have a problem generating the checksum in
  userspace.

Suggestion:

Would it make sense that if:
sysctl net.udp.checksum=1
and
udphdr->uh_sum = 0;
in a UDP packet created on a raw socket, to do the checksum in the kernel
instead of leaving it zero? If it does, I can create a patch.

Any other hints as how to do the checksum in userland are welcome too. As
that is the "ultimate" problem I try to fix.

Thanks

Mark