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From: Stephen Clark <sclark46@earthlink•net>
To: Bruce Curtis <brutus@google•com>
Cc: Eric Dumazet <eric.dumazet@gmail•com>,
	David Miller <davem@davemloft•net>,
	edumazet@google•com, netdev@vger•kernel.org
Subject: Re: [PATCH v3] net-tcp: TCP/IP stack bypass for loopback connections
Date: Thu, 20 Sep 2012 07:28:41 -0400	[thread overview]
Message-ID: <505AFDE9.4080602@earthlink.net> (raw)
In-Reply-To: <CAEkNxbEJjAu3+3yDGPGSzzee-LY_797RdNbBgcC6=-aDHfEAJQ@mail.gmail.com>

On 09/19/2012 05:19 PM, Bruce Curtis wrote:
> On Wed, Sep 19, 2012 at 2:03 PM, Eric Dumazet<eric.dumazet@gmail•com>  wrote:
>    
>> On Wed, 2012-09-19 at 16:34 -0400, David Miller wrote:
>>
>>      
>>> I have an idea on how to handle this.
>>>
>>> In drivers/net/loopback.c:loopback_tx(), skip the SKB orphan operation
>>> if there is a friend socket at skb->friend.
>>>
>>> When sending such friend SKBs out at connection startup, arrange it
>>> such that the skb->destructor will zap the skb->friend pointer to
>>> NULL.
>>>
>>> Also, in skb_orphan*(), if necessary, set skb->friend to NULL.
>>>
>>> skb->sk will hold a reference to the socket, and since skb->friend
>>> will be equal, this will make sure a pointer to an unreferenced
>>> socket does not escape.
>>>        
>> I now am wondering if we still need skb->friend field.
>>
>> If skb->sk is not zeroed by a premature skb_orphan(), then
>>
>> skb->sk->sk_friend gives the friend ?
>>
>>
>>      
Does this mean traffic on the loopback interface will not traverse 
netfilter?

-- 

"They that give up essential liberty to obtain temporary safety,
deserve neither liberty nor safety."  (Ben Franklin)

"The course of history shows that as a government grows, liberty
decreases."  (Thomas Jefferson)

  reply	other threads:[~2012-09-20 11:28 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-17 18:58 [PATCH v3] net-tcp: TCP/IP stack bypass for loopback connections Bruce "Brutus" Curtis
2012-09-17 20:20 ` Eric Dumazet
2012-09-17 23:08   ` Bruce Curtis
2012-09-19 20:34   ` David Miller
2012-09-19 21:03     ` Eric Dumazet
2012-09-19 21:17       ` David Miller
2012-09-19 21:19       ` Bruce Curtis
2012-09-20 11:28         ` Stephen Clark [this message]
2012-09-20 11:51           ` Eric Dumazet
2012-09-20 16:21             ` Bill Fink
2012-09-20 17:24             ` Rick Jones
2012-09-20 19:41               ` David Miller
2012-09-20 19:30           ` David Miller

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