When is the TCP Timestamp set?

Hello,

I'm programming on a version of TCP-AP for the linux-kernel which delays the TCP-Packets so there is a little space inbetween the sent packets... The delaying of the packages is working as expected. Unfortunately I seem to be delaying the packets after the point where the timestamp is set for the calculation of the roundtrip time. Since I also need the correct RTT-values for the packets, I need to fix this problem.

Until now, I haven't been able to find the point in the TCP-Code where the timestamp for the RTT calculation is set, so I was hoping someone on the Mailinglist could give me a hint which function is setting the timestamp.

Thank you for your help!

Tim Schneider