From owner-freebsd-current@FreeBSD.ORG Fri Nov 29 18:07:54 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id A82E6E6C for ; Fri, 29 Nov 2013 18:07:54 +0000 (UTC) Received: from mail-pd0-f170.google.com (mail-pd0-f170.google.com [209.85.192.170]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 781B515AF for ; Fri, 29 Nov 2013 18:07:54 +0000 (UTC) Received: by mail-pd0-f170.google.com with SMTP id g10so14302975pdj.1 for ; Fri, 29 Nov 2013 10:07:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:content-type:mime-version:subject:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to; bh=pKqVVysBn4l+j9NkqDgRFfJPrlhXdFJquzctqtecpDA=; b=RSy+bMPiKvjbAHZZYajAr6YPemOUm9gaKpWj/P+KU1JEgHxchNECtR+T7IdZGMQ1It 7VW5CncaQyy4qRm6bNoCmFGcC8PI8Ff0ErVTE/Qif6JNau5nPiM6ApgCCIWGBUYiq1gd 8ivhuOIa5wDNkV1nX4HykBWE/9ef4TYEroEIUTvHkVbEscmg4JCazsJKbPFoxRFCI4O/ xdbNenb0qj5/v8akyXv8RGs2ZMbF4w1GowNZOjnNfAVzsMP+L8qyOAfpzmYrWnv+MXSU QVqJHnh1gzkdxGl16hjRPsF6GlFLsNy4b5vQYpj3IoM3zEKKG4ylEQwW6UX5jN2nu1XV LQpg== X-Gm-Message-State: ALoCoQnwiYMtMb/6vRKraUA3bhL9ygb6tR5D2ob+SmizQ9JeogsvY+UQSKi3ApikRkSz5a0WOyXl X-Received: by 10.68.191.3 with SMTP id gu3mr17101147pbc.142.1385747992101; Fri, 29 Nov 2013 09:59:52 -0800 (PST) Received: from [192.168.2.123] (99-74-169-43.lightspeed.sntcca.sbcglobal.net. [99.74.169.43]) by mx.google.com with ESMTPSA id pu5sm117393195pac.21.2013.11.29.09.59.50 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 29 Nov 2013 09:59:51 -0800 (PST) Sender: Tim Kientzle Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.0 \(1822\)) Subject: Re: [PATCH] SO_REUSEADDR and SO_REUSEPORT behaviour From: Tim Kientzle In-Reply-To: Date: Fri, 29 Nov 2013 09:59:26 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: <4053E074-EDC5-49AB-91A7-E50ABE36602E@freebsd.org> References: To: =?windows-1252?Q?Ermal_Lu=E7i?= X-Mailer: Apple Mail (2.1822) Cc: freebsd-net , "freebsd-current@freebsd.org" X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Nov 2013 18:07:54 -0000 On Nov 29, 2013, at 4:04 AM, Ermal Lu=E7i wrote: > Hello, >=20 > since SO_REUSEADDR and SO_REUSEPORT are supposed to allow two daemons = to > share the same port and possibly listening ip =85 These flags are used with TCP-based servers. I=92ve used them to make software upgrades go more smoothly. Without them, the following often happens: * Old server stops. In the process, all of its TCP connections are = closed. * Connections to old server remain in the TCP connection table until the = remote end can acknowledge. * New server starts. * New server tries to open port but fails because that port is =93still = in use=94 by connections in the TCP connection table. With these flags, the new server can open the port even though it is =93still in use=94 by existing connections. > This is not the case today. > Only multicast sockets seem to have the behaviour of broadcasting the = data > to all sockets sharing the same properties through these options! That is what multicast is for. If you want the same data sent to all listeners, then that is multicast behavior and you should be using a multicast socket. > The patch at [1] implements/corrects the behaviour for UDP sockets. You=92re trying to turn all UDP sockets with those options into multicast sockets. If you want a multicast socket, you should ask for one. Tim