Hi,

I'm doing some kernel hacking to evaluate different TCP congestion
control algorithms in a WLAN mesh network.

I need to output some TCP parameters (such as window sizes et al) over
time; what I'd wish to do is outputting them to a character device
whenever a packet comes in/is sent.

I've written the device code, now I just need to output the parameters
using that device. The easiest way would be simply outputting the whole
tcp_sock structure to the device, and then reading it in from user space.

The problem is that I don't know where exactly in the TCP implementation
the packets are transmitted/received, i.e. where I should send the data
over to the device implementation.

The ideal case would of course be some kind of callback/hook function; I
imagine there might be something like this for the netfilter modules,
but I have no idea.

Can anybody help me with this?

Thank you,
Aaron
-- 
Aaron Isotton | http://www.isotton.com/
I'll give you a definite maybe. --Samuel Goldwyn