This is my fixed version of the tcp_probe.c kernel module for linux. The version that ships with the vanilla kernel was not suitable for me as it only writes to /proc/net/tcpprobe in large buffer bursts, whereas I needed to monitor short lived HTTP connections.

This version uses and EVENT_BUF value of 1 by default, which means every event is written to /proc/net/tcpprobe immediately. An event can be either the reception of a tcp segment of an established connection, or the change of the snd_cwnd (depending on whether or not the full module parameter is given).

Additionally, the timestamp is reset on every fopen of the /proc/net/tcp_probe file for easier plotting.

For more information and documentation on original tcp_probe, see:

<http://www.linuxfoundation.org/collaborate/workgroups/networking/tcpprobe>

The sample_plot folder contains a sample gnuplot plus two samples collected via this kernel modules that show congestion behaviour using tcp reno and linux' tcp_cubic.

Get and install matching linux-header package for your kernel and run make.

Usage: Same as the original tcp_probe module. I.e:

insmod tcp_probe_fixed.ko port=8080 full=1

Timo Dörr: [email protected]