Le lundi 29 novembre 2010 à 18:29 +0000, John Haxby a écrit :

Sorry,  I think I phrased my question badly.

inet_csk_get_port() starts its search for a free port with

     smallest_rover = rover = net_random() % remaining + low;

whereas __inet_hash_connect() basically misses out that call to 
net_random() so you get a predictable port number.

Is there any good reason why that is the case?

It seems random select was done at bind() time only in commit
6df716340da3a6f ([TCP/DCCP]: Randomize port selection)

It probably should be done in autobind too.