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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 747F3C282D7 for ; Sat, 2 Feb 2019 15:36:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41DF12086C for ; Sat, 2 Feb 2019 15:36:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="EnsM8p3z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728489AbfBBPgC (ORCPT ); Sat, 2 Feb 2019 10:36:02 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:41601 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728329AbfBBPgA (ORCPT ); Sat, 2 Feb 2019 10:36:00 -0500 Received: by mail-pl1-f195.google.com with SMTP id u6so4761569plm.8; Sat, 02 Feb 2019 07:35:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=0ep5fptQz+b8fID220B+upt0jj7H31zdPE/L67ZyhXc=; b=EnsM8p3zLK0L9damTbvV+8WeEHiGL6rfBUHB8u3Gk74AD1tNY8A+Fo+7nZ8EXu5wxw Oh2xzkUDidyzCwA7TYYtHom0Y0yWhpzpBpDK9IDN3m/6ORdfJueGGvoWd1h4CFoLEy4P CXQSg0gVV+TVgrjDKhP8v/EhpaHzLjZbRwcZqNPVeAVtJgEr7/IYrnuEc9DpZYJ+NK4G tf1RWXKd7w0BCuTREbFVNjpFwIwqPDO7ufG8f5gNMnx/hUutxB0rI5dk0LqQHT9pJa6y McZONevgKHZbdPitC9h+7ccksRZQLLumRKjH2MCJb4VwQzMWLe2gF2G1XLrT+evlplwc dKhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=0ep5fptQz+b8fID220B+upt0jj7H31zdPE/L67ZyhXc=; b=soV74BmzlIjG5lTrtBPp2hhp2qKmWZQHv3FlF3Ptz1HHVzXkM50bBdL+0bgfHxoD30 aVSFejmKE6GBbsqmKXAWJ0EtCV5RRmvwKE+qukmdUdadCCsonChy/uSU8Qx9XgOehPUF emw+7ANkq9aWpKha3ISip5g8+q3ddn6A8WSxYE7A/zotnde9iN+DBaEXSV+gBKnfRBZt wzM14vgG/4Eohqdq24eRU9LNT6KX13Bs4vI0+nz5wSYj/MxWq4IOhWCmY81abzlaBPmq tnQR+PIpDYVs+a8F0NvuLsc/MG8+H5s68UxtodAuB8D3PAPWK7n9Q/UIIWPU1E4fRtJz +DVg== X-Gm-Message-State: AJcUukervEFh/bLBCjP34c6c7fuexyBmRNazXPHlzo/l9bN6YI7azAWo Vk4Bi1Ct0kErvpc/riGbGp8OXoms9uw= X-Google-Smtp-Source: ALg8bN7XGV2l5/gwt7d+SdPfduXfVqUyuDmu+olZrqp5NHkZjCzEfm0cMZSQ6UQhfyTFqhEeFyDMnA== X-Received: by 2002:a17:902:2bc5:: with SMTP id l63mr45034188plb.107.1549121759525; Sat, 02 Feb 2019 07:35:59 -0800 (PST) Received: from localhost.localdomain ([49.206.15.111]) by smtp.gmail.com with ESMTPSA id m20sm16221611pgb.56.2019.02.02.07.35.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 02 Feb 2019 07:35:58 -0800 (PST) From: Deepa Dinamani To: davem@davemloft.net, linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org, arnd@arndb.de, y2038@lists.linaro.org Subject: [PATCH net-next v5 10/12] socket: Update timestamping Documentation Date: Sat, 2 Feb 2019 07:34:52 -0800 Message-Id: <20190202153454.7121-11-deepa.kernel@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190202153454.7121-1-deepa.kernel@gmail.com> References: <20190202153454.7121-1-deepa.kernel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With the new y2038 safe timestamping options added, update the documentation to reflect the changes. Signed-off-by: Deepa Dinamani Acked-by: Willem de Bruijn --- Documentation/networking/timestamping.txt | 43 ++++++++++++++++++++--- 1 file changed, 38 insertions(+), 5 deletions(-) diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 9d1432e0aaa8..bbdaf8990031 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -6,11 +6,21 @@ The interfaces for receiving network packages timestamps are: * SO_TIMESTAMP Generates a timestamp for each incoming packet in (not necessarily monotonic) system time. Reports the timestamp via recvmsg() in a - control message as struct timeval (usec resolution). + control message in usec resolution. + SO_TIMESTAMP is defined as SO_TIMESTAMP_NEW or SO_TIMESTAMP_OLD + based on the architecture type and time_t representation of libc. + Control message format is in struct __kernel_old_timeval for + SO_TIMESTAMP_OLD and in struct __kernel_sock_timeval for + SO_TIMESTAMP_NEW options respectively. * SO_TIMESTAMPNS Same timestamping mechanism as SO_TIMESTAMP, but reports the - timestamp as struct timespec (nsec resolution). + timestamp as struct timespec in nsec resolution. + SO_TIMESTAMPNS is defined as SO_TIMESTAMPNS_NEW or SO_TIMESTAMPNS_OLD + based on the architecture type and time_t representation of libc. + Control message format is in struct timespec for SO_TIMESTAMPNS_OLD + and in struct __kernel_timespec for SO_TIMESTAMPNS_NEW options + respectively. * IP_MULTICAST_LOOP + SO_TIMESTAMP[NS] Only for multicast:approximate transmit timestamp obtained by @@ -22,7 +32,7 @@ The interfaces for receiving network packages timestamps are: timestamps for stream sockets. -1.1 SO_TIMESTAMP: +1.1 SO_TIMESTAMP (also SO_TIMESTAMP_OLD and SO_TIMESTAMP_NEW): This socket option enables timestamping of datagrams on the reception path. Because the destination socket, if any, is not known early in @@ -31,15 +41,25 @@ same is true for all early receive timestamp options. For interface details, see `man 7 socket`. +Always use SO_TIMESTAMP_NEW timestamp to always get timestamp in +struct __kernel_sock_timeval format. -1.2 SO_TIMESTAMPNS: +SO_TIMESTAMP_OLD returns incorrect timestamps after the year 2038 +on 32 bit machines. + +1.2 SO_TIMESTAMPNS (also SO_TIMESTAMPNS_OLD and SO_TIMESTAMPNS_NEW): This option is identical to SO_TIMESTAMP except for the returned data type. Its struct timespec allows for higher resolution (ns) timestamps than the timeval of SO_TIMESTAMP (ms). +Always use SO_TIMESTAMPNS_NEW timestamp to always get timestamp in +struct __kernel_timespec format. + +SO_TIMESTAMPNS_OLD returns incorrect timestamps after the year 2038 +on 32 bit machines. -1.3 SO_TIMESTAMPING: +1.3 SO_TIMESTAMPING (also SO_TIMESTAMPING_OLD and SO_TIMESTAMPING_NEW): Supports multiple types of timestamp requests. As a result, this socket option takes a bitmap of flags, not a boolean. In @@ -323,10 +343,23 @@ SO_TIMESTAMP and SO_TIMESTAMPNS records can be retrieved. These timestamps are returned in a control message with cmsg_level SOL_SOCKET, cmsg_type SCM_TIMESTAMPING, and payload of type +For SO_TIMESTAMPING_OLD: + struct scm_timestamping { struct timespec ts[3]; }; +For SO_TIMESTAMPING_NEW: + +struct scm_timestamping64 { + struct __kernel_timespec ts[3]; + +Always use SO_TIMESTAMPING_NEW timestamp to always get timestamp in +struct scm_timestamping64 format. + +SO_TIMESTAMPING_OLD returns incorrect timestamps after the year 2038 +on 32 bit machines. + The structure can return up to three timestamps. This is a legacy feature. At least one field is non-zero at any time. Most timestamps are passed in ts[0]. Hardware timestamps are passed in ts[2]. -- 2.17.1