lkml.org 
[lkml]   [1999]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: seq numbers and checksum in tcp
   Date: 	Sun, 17 Jan 1999 23:51:41 -0600
From: Ayman El-Khashab <ayman@ccwf.cc.utexas.edu>

for some research that i am working on, i am doing some experiments
with the linux kernel and some tcpip stuff in particular. In any
case, in the tcp_rcv function, i have been able to get most of the
information that i need. Now i need to modify the sequence number
of the packet and then recompute the checksum, but i am not sure
how to go about this. I have expermimented for a while and turned
up nothing.

basically, i want to just modify the th->seq and then recompute
the tcp checksum and i suspect the skb checksum.

Why do you need to recompute the checksum on incoming packets, at
tcp_rcv() the checksum has already been validated as correct and is
never checked again? ie. nobody else cares about the checksum

Later,
David S. Miller
davem@dm.cobaltmicro.com


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:49    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site