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Message-ID: <1430512894.3711.140.camel@edumazet-glaptop2.roam.corp.google.com>
Subject: Re: [PATCH] Allow TCP connections to cache SYN packet for userspace
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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Eric B Munson <emunson@akamai.com>
Cc: Tom Herbert <tom@herbertland.com>, "David S. Miller" <davem@davemloft.net>,
        Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
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        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        Patrick McHardy <kaber@trash.net>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        linux-api@vger.kernel.org, linux-kernel@vger.kernel.org
Date: Fri, 01 May 2015 13:41:34 -0700
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On Fri, 2015-05-01 at 16:29 -0400, Eric B Munson wrote:

>  
> 
> As long as your implementation provides the IP and TCP headers, I would
> be happy with that.  I am also happy to rework my implementation to
> extract and cache information when the request structure is built.  If
> you all have an implementation that you want to post, I will add my ack
> if it meets our needs as well.

Yes, I believe it will be easier we provide our implementation instead
of reviewing yours ;)

For example you had :

+       case TCP_SAVED_SYN:
+               if (!((1 << sk->sk_state) & TCPF_LISTEN))
+                       err = -EINVAL;
+               tp->saved_syn = !!(val);
+               break;


But if you return an error, tp->saved_syn should be left unchanged.