[SLUG] kernel code for client ephemeral port allocation?

[Sonia Hamilton <sonia@xxxxxxxxxxxx>]

When a tcp (or udp) connection is setup, the client is allocated a
source port - a so-called ephemeral port (this can be seen in the Local
Address column of netstat).

Out of interest, I wouldn't mind looking at the code that
pseudo-randomly allocates this port number. Can anyone point me in the
direction of the directory (or even file) I should look at? I'm not 
very familiar with the layout of the kernel code.

-- 
Thanks,

Sonia Hamilton
http://soniahamilton.wordpress.com
http://www.linkedin.com/in/soniahamilton