From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4A0DC433C1 for ; Fri, 19 Mar 2021 18:51:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F50E6194A for ; Fri, 19 Mar 2021 18:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230049AbhCSSuv (ORCPT ); Fri, 19 Mar 2021 14:50:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229925AbhCSSum (ORCPT ); Fri, 19 Mar 2021 14:50:42 -0400 Received: from mail-pg1-x533.google.com (mail-pg1-x533.google.com [IPv6:2607:f8b0:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4493BC06174A for ; Fri, 19 Mar 2021 11:50:42 -0700 (PDT) Received: by mail-pg1-x533.google.com with SMTP id f8so865648pgi.9 for ; Fri, 19 Mar 2021 11:50:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:subject:message-id:mime-version :content-transfer-encoding; bh=6pOFYk2WAqSs2z2QkgB8UJEp0rKmYY0L3UJjWNMKXVk=; b=AHE1PpzjY0JAMQ2tO6W9VFeq/t2DucfvDVMPZ6m3/HKEJRVNMnzuO0cfFO7VDj4KWe yspxPGJWkhy00fcjrqQ52uKOxGM/N9NokdenSqIvnaOn7/zOFq0LXKosy8/6WqdC5pyU 4IKqSbBNdmecH/wLzlNbYmaF7LjfPKyDMXL7mlajEYdtkcYRUc6hpFibQnbDFu7t8Slu cNseHzxKT7nU2+sgtD5FkSJhC53muok1MdqID/4uB5GNLhVNqWNfC3+g8m8jtACLrrrr OE+MbEWNvzonRq+n8uQFUtgv+dc0ipWwnd/FO123j07VUrKTsVc11gBByzWN0dEEH6th Rmrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-transfer-encoding; bh=6pOFYk2WAqSs2z2QkgB8UJEp0rKmYY0L3UJjWNMKXVk=; b=Ni3cuOgPHeoH0qkdT7Lav4SSAI6uKWZ0sIsLjCHw9xS2V9bASJsL3cNQsyC4S5J3bu 0p9Honp5n0lQEyz65UCJt0c8S+WOuK08ZL9t544Y4opIqZ3ItM4zYKnMeK12RDiroM7m 9L08rRgE+ERGyfo+idHuzASv46TBNF3YcLhW32yW+QYfRrItgoYqp2TtVVkQlphOIv7/ Q9y0INxkB9q94RmM/TrFfxdgFVLwOb6+MkDoXuR6K7FMd4spUSl69LK/8ghjZ24dVY10 xq4hk+GDSfxcMlqTNfgJQIKTZGv9VbuBpP8WO0NrmMIKmssQESOGZfu8LDeR54ZTbjq7 XhrQ== X-Gm-Message-State: AOAM530aFnPonZyLKHLdhY0GBaIhnYAxz+JJHLju6H8kLyOK1wgdGVEs sJdJd93g3208Jlzyed0aJfjoWCpGcp+diQ== X-Google-Smtp-Source: ABdhPJypbn1Or5A5X9hNIM8W/Ck2VbH8g55ea7ZiqxfMBRb5ConHVqOXICSgkXhRtEjlsa3XEMQDTw== X-Received: by 2002:a65:6a4b:: with SMTP id o11mr12700384pgu.138.1616179838828; Fri, 19 Mar 2021 11:50:38 -0700 (PDT) Received: from hermes.local (76-14-218-44.or.wavecable.com. [76.14.218.44]) by smtp.gmail.com with ESMTPSA id q5sm5929246pfk.219.2021.03.19.11.50.38 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Mar 2021 11:50:38 -0700 (PDT) Date: Fri, 19 Mar 2021 11:50:35 -0700 From: Stephen Hemminger To: netdev@vger.kernel.org Subject: Fw: [Bug 212353] New: Requesting IP_RECVTTL via setsockopt returns IP_TTL via recvmsg()'s cmsghdr Message-ID: <20210319115035.11272a9c@hermes.local> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Begin forwarded message: Date: Fri, 19 Mar 2021 07:04:12 +0000 From: bugzilla-daemon@bugzilla.kernel.org To: stephen@networkplumber.org Subject: [Bug 212353] New: Requesting IP_RECVTTL via setsockopt returns IP_TTL via recvmsg()'s cmsghdr https://bugzilla.kernel.org/show_bug.cgi?id=212353 Bug ID: 212353 Summary: Requesting IP_RECVTTL via setsockopt returns IP_TTL via recvmsg()'s cmsghdr Product: Networking Version: 2.5 Kernel Version: 4.12.14-122.63-default (SLES12 SP5) Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Other Assignee: stephen@networkplumber.org Reporter: Ulrich.Windl@rz.uni-regensburg.de Regression: No Trying to get IP_RECVTTL, I noticed that recvmsg() returns IP_TTL, not IP_RECVTTL in struct cmsghdr. Example xode being used was similar to https://stackoverflow.com/a/49308499/6607497 that checks for IP_RECVTTL in struct cmsghdr: ... int yes = 1; setsockopt(soc, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)); ... int ttl = -1; struct cmsghdr * cmsg = CMSG_FIRSTHDR(&hdr); for (; cmsg; cmsg = CMSG_NXTHDR(&hdr, cmsg)) { if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IP_RECVTTL ) { uint8_t * ttlPtr = (uint8_t *)CMSG_DATA(cmsg); ttl = *ttlPtr; break; } } // ttl is now either the real ttl or -1 if something went wrong -- You may reply to this email to add a comment. You are receiving this mail because: You are the assignee for the bug.