From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965388Ab0COQUm (ORCPT ); Mon, 15 Mar 2010 12:20:42 -0400 Received: from mail-bw0-f209.google.com ([209.85.218.209]:39049 "EHLO mail-bw0-f209.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965346Ab0COQUg (ORCPT ); Mon, 15 Mar 2010 12:20:36 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=MD8ayYraTRZUc5l/Vvlzq/Xvl/RiEWTfOFvf+3U3Wq+x7pH7ShE2vmr7U4186N5WGb 7IzTMa50klxzbnFaSic8tSGq7ZIJTroakjwrXpkZvS1g6J5/wxqnJLX0gHDY+Kz9GFLJ oSQM6S69Dzvg0uMEBJ/hT4wJCHtXJBhNR067k= Subject: Re: Seeing TCP socket options (nodelay, cork, etc) in Linux procfs or elsewhere? From: Eric Dumazet To: "MacCana, Mike" Cc: linux-kernel@vger.kernel.org In-Reply-To: <5608FA8A997F1A46B7E985494F8478DD07930AF1@ELON17P32003A.csfb.cs-group.com> References: <5608FA8A997F1A46B7E985494F8478DD07930AF1@ELON17P32003A.csfb.cs-group.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 15 Mar 2010 17:20:31 +0100 Message-ID: <1268670031.3154.35.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le lundi 15 mars 2010 à 15:49 +0000, MacCana, Mike a écrit : > Hi kernel folks, > > I was wondering if there was a standard location to see TCP socket > options (eg, nodelay, cork, etc), perhaps via procfs or some other > means? I'd like to check whether arbitrary apps (for which I don't have > code) are using particular TCP options. > > Wandering round /proc/net hasn't turned up anything yet, and after a > quick: > socket.setsockopt(0, 1, 1) > to enable NODELAY I can't see any obvious difference in procfs or > netstat output (where other Unixes seem to put this info). hat's the > best way to see TCP options on sockets created by others' code? > There is limited support given by ss command (part of iproute2) : ss -emoi ESTAB 0 0 55.225.18.5:4900 55.225.18.5:50000 uid:501 ino:135421 sk:c3b405c0 mem:(r0,w0,f4096,t0) ts bic wscale:6,6 rto:201 rtt:1/0.5 ato:40 cwnd:3 send 393.2Mbps rcv_space:32768 But CORK flag is not exported yet (its usually a volatile flag, at least with Apache server)