From patchwork Tue Mar 19 06:52:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fernando Luis Vazquez Cao X-Patchwork-Id: 228923 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4021E2C00AE for ; Tue, 19 Mar 2013 17:56:02 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756841Ab3CSGz4 (ORCPT ); Tue, 19 Mar 2013 02:55:56 -0400 Received: from tama500.ecl.ntt.co.jp ([129.60.39.148]:51070 "EHLO tama500.ecl.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754763Ab3CSGz4 (ORCPT ); Tue, 19 Mar 2013 02:55:56 -0400 Received: from mfs5.rdh.ecl.ntt.co.jp (mfs5.rdh.ecl.ntt.co.jp [129.60.39.144]) by tama500.ecl.ntt.co.jp (8.13.8/8.13.8) with ESMTP id r2J6qeMM003426; Tue, 19 Mar 2013 15:52:40 +0900 Received: from mfs5.rdh.ecl.ntt.co.jp (localhost.localdomain [127.0.0.1]) by mfs5.rdh.ecl.ntt.co.jp (Postfix) with ESMTP id 97A21E015F; Tue, 19 Mar 2013 15:52:40 +0900 (JST) Received: from imail1.m.ecl.ntt.co.jp (imail1.m.ecl.ntt.co.jp [129.60.5.246]) by mfs5.rdh.ecl.ntt.co.jp (Postfix) with ESMTP id 81510E0161; Tue, 19 Mar 2013 15:52:40 +0900 (JST) Received: from [129.60.240.190] (nexus.sic.ecl.ntt.co.jp [129.60.240.190]) by imail1.m.ecl.ntt.co.jp (8.13.8/8.13.8) with ESMTP id r2J6qetn002625; Tue, 19 Mar 2013 15:52:40 +0900 Message-ID: <1363675960.4767.10.camel@nexus> Subject: [PATCH 2/2] man/send(2): document a long standing bug that can cause spurious EPERM errors From: Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao To: Michael Kerrisk Cc: linux-man@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, Pablo Neira Ayuso , Patrick McHardy , Hirotaka Sasaki Date: Tue, 19 Mar 2013 15:52:40 +0900 In-Reply-To: <1363675513.4767.6.camel@nexus> References: <1363675513.4767.6.camel@nexus> Organization: NTT Open Source Software Center X-Mailer: Evolution 3.4.4-2 Mime-Version: 1.0 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Subject: [PATCH 2/2] man/send(2): document a long standing bug that can cause spurious EPERM errors This bug has been known since early 2009 (the latest) and discussed in netdev before: http://marc.info/?l=linux-netdev&w=2&r=1&s=Possible+race+condition+in+conntracking+&q=b It seems that a proper fix would be non trivial, so document the bug in the meantime. Reported-by: Hirotaka Sasaki Signed-off-by: Fernando Luis Vazquez Cao --- -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff -urNp man-pages-3.50-orig/man2/send.2 man-pages-3.50/man2/send.2 --- man-pages-3.50-orig/man2/send.2 2013-03-19 15:18:03.784306647 +0900 +++ man-pages-3.50/man2/send.2 2013-03-19 15:30:40.788060426 +0900 @@ -420,6 +420,11 @@ Linux may return .B EPIPE instead of .BR ENOTCONN . + +Linux may return spurious +.B EPERM +errors when netfilter's conntrack module is loaded and two or more +UDP packets belonging to the same connection are processed in parallel. .SH EXAMPLE An example of the use of .BR sendto ()