libipq

James Morris jmorris@intercode.com.au
Sat, 27 Oct 2001 15:39:22 +1000 (EST)


On 26 Oct 2001, Crg wrote:

> Yes, I modified both the ip & tcp headers, both fields relating to
> lengths, and correctly computed the new checksum.  The problem I am
> seeing is unrelated to the checksum.  The modified packet is smaller
> than the original one, and I am seeing some of the original data being
> sent out, even though the ip/tcp lengths and the data_len passed back to
> ipq_set_verdict are correct (ie the new packet size).  for example say
> the original packet was
>
> IPHDRTCPHDRDATAAAAAAAAAAAAAAAAAAAAAAAAA and I change it to
> IpHdrTcpHdrDatabbbbbbbbbbbbbb           what I see on the network is
> IpHdrTcpHdrDatabbbbbbbbbbbbbbAAAAAAAAAA
>
> Possibly this is the way its supposed to work, ie the packet has to stay
> the same size.  Just wondering if anyone knows?

This should work as you expect.  Can you post some code which demonstrates
the problem?


- James
-- 
James Morris
<jmorris@intercode.com.au>