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=-9.1 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=ham 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 31D29C282D8 for ; Fri, 1 Feb 2019 15:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0086B218EA for ; Fri, 1 Feb 2019 15:45:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QfCvIWSC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730336AbfBAPpk (ORCPT ); Fri, 1 Feb 2019 10:45:40 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:34223 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727308AbfBAPpj (ORCPT ); Fri, 1 Feb 2019 10:45:39 -0500 Received: by mail-pg1-f195.google.com with SMTP id j10so3120606pga.1; Fri, 01 Feb 2019 07:45:38 -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=QfCvIWSCQe9vkmpDAxpIxtQS5UYzGfBuSAfzSJINgIjA4pJGondlsYFs82fyZ2jmfQ z6JnIB+qoHDZbFwksqaobuwyxZ6JPfnmi4vUuyZ2P49LMlL9ninwjUU4Y1bOCZtllgf5 3d6fvHoB+Kp996kKUh5eHYbNs1yPMg4ee+8c9jcq7s+Tsl1ASHJ2ALHHaS5ngA6dDm3L ZSD3ig6yOqgMgpEOc/QU50zgXMDObTdyqeN/pUWjV1C9r9ia+wWDL7wOE1qMtvBoK4Lv imGPxbUbcuZnEGfIzAWW/msqGHjYjogzHkmLiuFhKSluaqnWBV1PqLBJw1eAOXKhSbSH lD7w== 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=DNJlOS5vDt7qQeY7JSzwIi79ZG4Huh+YEg+4B5FN4Dgrh88vZlltQ425UvOl4qBD0H Dk9li/YA2C96ITjrFiOKy4H9eeshPy4Ff6PwbX3R+bmnGeRM7mdKX3GOyMpzkjWeuJAR McC6+vMRxoKKl4XxxR8LMZv3ymQ7uzM+2/jncZTNwx1uXw6Naulv6QQo3rEnxGbeFLLh C0M0NHoG8QOKrsKf+XB1UuHNVjsjIoXTvIOkJv/C8UBHFBTuPGKzpdqtiodWYv84qpEG WJjX0ve3D1pQaYkwno+daTPtzX4om5ctsMeO+/EA+/RX04PFaG14b+JcErFjtQ28CUpw Z4CA== X-Gm-Message-State: AHQUAuZ8t8sPIM8MtYn5PfSL+qOCMS+ysbbMUTWlZM+5Fg3rQHtj9EJ1 z91EqZCJl6iOwQlunpB/ouI= X-Google-Smtp-Source: AHgI3Iabc/40oIPeu+P0yAT5SRDnInJ2cggyhTtIuDo8cX1nHNBmrpWL4B+6ABqmy+TAo3LZq8plRQ== X-Received: by 2002:a63:2263:: with SMTP id t35mr2747064pgm.69.1549035938377; Fri, 01 Feb 2019 07:45:38 -0800 (PST) Received: from localhost.localdomain ([49.206.15.111]) by smtp.gmail.com with ESMTPSA id z9sm25886959pfd.99.2019.02.01.07.45.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Feb 2019 07:45:37 -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 v4 10/12] socket: Update timestamping Documentation Date: Fri, 1 Feb 2019 07:43:54 -0800 Message-Id: <20190201154356.15536-11-deepa.kernel@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190201154356.15536-1-deepa.kernel@gmail.com> References: <20190201154356.15536-1-deepa.kernel@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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