Hi lartc users, When a packet arrived to a network device it was stored on a skb structure and then enqueue on a network stack. One of the tests that I want to do is modify the TCP window size and verify the changes on the bandwidth between two hosts. To do that I need to know how to modify de packet window size and maybe recalculate the checksum value of the TCP packet. All I can do is read the information of the packet stored on the skb structure. Do you have any ideas? I''ll need to be enlighted Ricardo _________________________________________________________________ MSN Messenger: converse com os seus amigos online. http://messenger.msn.com.br _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
Ricardo Leite wrote:> Hi lartc users, > > When a packet arrived to a network device it was stored on a skb > structure and then enqueue on a network stack. > > One of the tests that I want to do is modify the TCP window size and > verify the changes on the bandwidth between two hosts. > To do that I need to know how to modify de packet window size and > maybe recalculate the checksum value of the TCP packet. > > All I can do is read the information of the packet stored on the skb > structure.I think I saw a patch in patchomatic for iptables to modify window size. Perhaps have a look at that and see if it offers you some clues. I seem to remember the answer is in the ACK packets sent back to the server? Ed W _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/