Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756156AbYAHXq2 (ORCPT ); Tue, 8 Jan 2008 18:46:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753331AbYAHXqS (ORCPT ); Tue, 8 Jan 2008 18:46:18 -0500 Received: from py-out-1112.google.com ([64.233.166.182]:10491 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753087AbYAHXqR (ORCPT ); Tue, 8 Jan 2008 18:46:17 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=edxLj2Spp7daOQ6awjzBq4tK55ppGz/Z/BkiXx2qfQXtDMt6FRBorXKT8pwvPT7YlayjlcV2BCEwPaBNzXoBTiPprkcY60xZzWZ1ee9SeWIw4PH/UKdcguX9w6vt9cwEyDKiszdfsfNTA/Qsbr3xKAmsMloTeSeezwSTQpu2fUQ= Message-ID: <7b9198260801081546u50f11e9ck32ec6f071efa300d@mail.gmail.com> Date: Tue, 8 Jan 2008 23:46:15 +0000 From: "Tom Spink" To: "Brent Casavant" Subject: Re: AF_UNIX MSG_PEEK bug? Cc: "Rick Jones" , netdev@vger.kernel.org, "David Miller" , linux-kernel@vger.kernel.org In-Reply-To: <7b9198260801081539x7aee72fbm53b5f298c5faf56@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <4783FBD6.1000004@hp.com> <7b9198260801081453s198af7efycc7c35668c65eaf1@mail.gmail.com> <7b9198260801081539x7aee72fbm53b5f298c5faf56@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1717 Lines: 53 On 08/01/2008, Tom Spink wrote: > On 08/01/2008, Brent Casavant wrote: > > On Tue, 8 Jan 2008, Tom Spink wrote: > > > > > Where in the code is the message length being sent across the socket? > > > > In do_producer(), there are the following lines in the main loop: > > > > /* Send random lengths of data */ > > messages[i].length = (rand() % MAXLEN) + sizeof(size_t); > > iov[i].iov_len = messages[i].length; > > > > The entire "struct sockmsg" is sent across the socket, so the first > > size_t in each message contains the length of the entire message > > (including the size_t). This size gets picked up at the > > recv(...,MSG_PEEK) line in do_consumer(). > > > > Thanks, > > Brent > > > > -- > > Brent Casavant All music is folk music. I ain't > > bcasavan@sgi.com never heard a horse sing a song. > > Silicon Graphics, Inc. -- Louis Armstrong > > > > Hi, > > But you're not consuming the size_t on the other end. You're only > peeking it, i.e. you're doing the recv to peek at the message, but > never calling recv to remove that data from the queue... or am I > missing something? > > -- > Regards, > Tom Spink > University of Edinburgh > Ach. I *am* missing something... and what I'm missing is my understanding of the sendmsg and recvmsg calls. A quick Google has sorted me out. -- Regards, Tom Spink University of Edinburgh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/