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From: David Miller <davem@davemloft.net>
To: shemminger@vyatta.com
Cc: dada1@cosmosbay.com, herbert@gondor.apana.org.au, netdev@vger.kernel.org
Subject: Re: GTSM and TCP accept problem
Date: Sat, 14 Aug 2010 22:12:58 -0700 (PDT)	[thread overview]
Message-ID: <20100814.221258.35029372.davem@davemloft.net> (raw)
In-Reply-To: <20100814214634.24a87715@s6510>

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Sat, 14 Aug 2010 21:46:34 -0400

> The implementation of Generalized TTL Security has a problem
> on the TCP accept side. Since there can be different number of
> hops for each peer, the listener ends up doing
> 
>    socket
>    bind
>    set TTL to 255
>    listen
>    while (nfd = accept(peer)) {
>      info = lookup(peer)
>      set MINTTL to 255 - info->ttl_hops

Surely when creating the initial listening socket we should use the
minimum TTL over the set of peers right?

That surely takes most of the fun out of this problem for the
attacker.

  reply	other threads:[~2010-08-15  5:12 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-15  1:46 GTSM and TCP accept problem Stephen Hemminger
2010-08-15  5:12 ` David Miller [this message]
2010-08-15 16:38   ` Stephen Hemminger
2010-08-16  9:43 ` Eric Dumazet
2010-08-18 21:39   ` Stephen Hemminger
2010-08-18 21:48     ` David Miller
2011-10-03  1:46       ` venkatesh natarajan

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