How to modify TCP/IP mechanism?

[TimeSync2]

Please help！

I am doing an experiment on client-server TCP mechanism. I wanted to modify the client and server exchange of message. Is there anyone there who can give me a hint on how to do it, what kernel module should I modify and other related things that I should know?

Thank you very much.

AJ

[RobinVossen]

Hello,
Well If I understand your Question you dont have to mod your kernel atall.
Since TCP/IP is used since 19(long ago) by all OSes.
So, well I guess you want to do Package Forging.
But I dont know for sure you have the power to do real intresting stuff with that... (Its really really hard )
Well, if that is what you want check scapy and hping.

If you want to check the TCP data stream check TCPdump and Wireshark.

Well, hope that helped abit..

If I didnt help, can you please rephrase the Question?

[TimeSync2]

Thank you for the quick reply. My real purpose is to modify how the client and server exchange the messages in TCP connection, and at the same time, be able to modify the IP header and do some functions. I know that it is a violation to already-defined protocols, but what I am supposed to do is an experiment for my research study. My problem is i dont know where to start as I am not an expert linux kernel programmer.

I have used packet capturing softwares used for checking the data stream and they're a great help.

Thank you again.