Linux Sequence Number Generation

Hello,
Can anybody tell me about Linux 2.6 sequence number
generation???
Suppose i caught a packet using PRE_ROUTING hook and i want to modify
the packet that will be response for our caught packet.. So how can I
map an outgoing packet (a reply) to a recieved packet..

Regards,
Sunny

Re: Linux Sequence Number Generation

"Sunny" writes:

> Hello,
> Can anybody tell me about Linux 2.6 sequence number
> generation???
> Suppose i caught a packet using PRE_ROUTING hook and i want to modify
> the packet that will be response for our caught packet.. So how can I
> map an outgoing packet (a reply) to a recieved packet..

What sequence numbers are you talking about? TCP sequence numbers?

The mapping of the reply to the request is done by taking the ACK
value of the incoming packet and using that for the sequence number
for the reply packet.

More on the topic of tcp spoofing here and other places
http://www.signaltonoise.net/library/ipsp00f.htm


Best Regards,
--
Todd H.
http://www.toddh.net/