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From: Eric Dumazet <eric.dumazet@gmail.com>
To: John Haxby <john.haxby@oracle.com>
Cc: NetDev <netdev@vger.kernel.org>,
	Stephen Hemminger <shemminger@vyatta.com>
Subject: Re: inet_hash_connect: source port allocation
Date: Mon, 29 Nov 2010 19:46:03 +0100	[thread overview]
Message-ID: <1291056363.3435.1338.camel@edumazet-laptop> (raw)
In-Reply-To: <4CF3F114.2070108@oracle.com>

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.




  reply	other threads:[~2010-11-29 18:46 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-29 17:04 inet_hash_connect: source port allocation John Haxby
2010-11-29 17:26 ` Eric Dumazet
2010-11-29 18:29   ` John Haxby
2010-11-29 18:46     ` Eric Dumazet [this message]
2010-11-29 19:07       ` Eric Dumazet
2010-11-29 19:21         ` Eric Dumazet
2010-11-29 19:38         ` Stephen Hemminger

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