In TCP, I need to modify the checksum and data fields of every 5th packet. I don't believe the Netfilter lets me do this, and would rather work straight in the kernel itself. The packets are generated through the tcp_write-xmit function in TCP_OUTPUT. I have successfully modified the checksum for ALL packets (by playing with tcp_v4_send_check in TCP_IPV4), but, need to whittle it down to every 5th packet only. Any suggestions on how to implement such a counter? Also, any ideas on replacing the entire TCP data field of every 5th packet? Thanks in advance. Get 250 color business cards for FREE! http://businesscards.lycos.com/vp/fastpath/ - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org
