Linux socket timestamp However: The documentation says that SO_TIMESTAMP is for incoming packets, while SO_TIMESTAMPING is for outgoing packets. SO_TIMESTAMP Enable or disable the receiving of the SO_TIMESTAMP control message. 10 最近看内核参数tcp_tw_recycle(该参数在内核 4. Dec 11, 2021 · 为啥要获取数据包到达网卡的时间？在回答这个问题之前，我们先看一下网卡消息队列。如下图所示，对端发送的网络数据包被网卡设备接收到之后，会存放到网卡消息队列中，由应用程序调用recv系列函数从网卡队列中获取网络消息。 文章浏览阅读695次。linux系统中，tcp套接字的so_timestamp和so_timestampns选项不能同时启用，因为它们共享同一结构体成员。手册页指出两者互斥，查看源代码可以发现，当尝试同时使用时，可能导致数据混乱。 skb_tx_timestamp() provides a software time stamp if requested and hardware timestamping is not possible (SKBTX_IN_PROGRESS not set). 1 SCM_TIMESTAMPING records These timestamps are returned in a control message with cmsg_level SOL_SOCKET, cmsg_type SCM_TIMESTAMPING, and payload of type skb_tx_timestamp() provides a software time stamp if requested and hardware timestamping is not possible (SKBTX_IN_PROGRESS not set). Linux Kernel offers a few ways to get timestamps for received (SO_TIMESTAMP, SO_TIMESTAMPNS, SO_TIMESTAMPING) or sent (SO_TIMESTAMPING) packets. linux内核打戳查看 （1）打戳模式设置： 代码文件： sk. Just to check sock_get_timestamp is used in inet_ioctl in af_inet. I Ideally we would like a timestamp issued at the exact time of transmission, when the packet leave the device. c linux sockets timestamp udp. Linux supports RFC 1323 TCP high performance extensions. . May 25, 2017 · I've discovered why it doesn't work. c 函数接口： setsockopt -> setsockopt sock_setsockopt 代码位置： PTP代码 -》 内核代码 作用：设置软硬件时间戳，发送接收时间戳； （ Mar 24, 2014 · 在setsockopt函数中常用Socket选项对socket进行一些必要的设置，使socket可以按我们预期的特性去工作。 SO_TIMESTAMP，一个Socket选项，在权威著作《Unix网络编程》中未提及到，即使在google上也难找到其详细解释与用法。 Apr 16, 2020 · 在setsockopt函数中常用Socket选项对socket进行一些必要的设置，使socket可以按我们预期的特性去工作。SO_TIMESTAMP，一个Socket选项，在权威著作《Unix网络编程》中未提及到，即使在google上也难找到其详细解释与用法。 Apr 18, 2024 · The socket manual page (man 7 socket) describes how timestamps generated with SO_TIMESTAMP and SO_TIMESTAMPNS records can be retrieved. skb_hwtstamp_tx() clones the original skb and adds the timestamps, therefore the original skb has to be freed now. Because the destination socket, if any, is not known early in the network stack, the feature has to be enabled for all packets. The socket manual page (man 7 socket) describes how timestamps generated with SO_TIMESTAMP and SO_TIMESTAMPNS records can be retrieved. Dec 18, 2020 · Linux内核提供了两个套接字选项，用于检索传入网络数据包的软件时间戳：SO_TIMESTAMP和带有SOF_TIMESTAMPING_RX_SOFTWARE | SOF_TIMESTAMPING_SOFTWARE标志的SO_TIMESTAMPING。将它们描述如下：SO_TIMESTAMP在(不一定是单调的)系统时间内为每个传入数据包生成时间戳。SO_TIMESTAMPING当数据进入内核时请求 Apr 1, 2020 · But right above that function is sock_get_timestamp and sock_get_timestampns. This project is about A socket which has had accept(2) or connect(2) successfully called on it is fully specified and may transmit data. I Not possible in the real world, the timestamp has to occur before. Timestamps 选项是什么除了我们之前介绍的 MSS、Window Scale 还有以一个非常重要的选项：时间戳（TCP Timestamps Option，TSopt）。这个选项在 TCP 头部的位置如下所示。 Timestamps 选项最初是在 RFC 1323 中引… This ioctl should only be used if the socket option SO_TIMESTAMP is not set on the socket. SIOCSPGRP 我一直试图让Linux (内核4. – Gio Mar 17 '16 at 9:331 it doesn't make sense to ask for timestamps for TCP, because there's no direct correlation between arriving packets and data becoming available. The timestamp control message is sent with level SOL_SOCKET and a cmsg_type of SCM_TIMESTAMP. 12 之后被移除），它用于快速回收处理TIME_WAIT状态的socket。搜索该参数相关的资料，发现同时启用该参数和tcp_timestamps后有可能在NAT环境下导致客户端始连接失败，抓包 Dec 18, 2020 · Linux kernel provides two socket options for retrieving software timestamps of incoming network packets: SO_TIMESTAMP and SO_TIMESTAMPING with SOF_TIMESTAMPING_RX_SOFTWARE | SOF_TIMESTAMPING_SOFTWARE flags. Linux ICMP internally uses a raw socket to send ICMPs. 2. Oct 15, 2015 · In Linux, you will receive the timestamp in a data structure outside of the packet itself. 1 SCM_TIMESTAMPING records ¶ These timestamps are returned in a control message with cmsg_level SOL_SOCKET, cmsg_type SCM_TIMESTAMPING, and payload of type Jun 14, 2017 · Supports generating timestamps for stream sockets. Else it will be managed by the kernel. I Two possibilities: in software and in hardware. Otherwise, it returns the timestamp of the last packet that was received while SO_TIMESTAMP was not set, or it fails if no such packet has been received, (i. The server code as below: SO_TIMESTAMP Enable or disable the receiving of the SO_TIMESTAMP control message. c -> socket. SIOCGSTAMP only works for UDP packets or RAW sockets, but does not work for TCP. 4）发送和接收UDP数据包的时间戳，但一直失败。 Feb 13, 2017 · Normally hardware that supports this functionality will see the socket option (SO_TIMESTAMPNS or SO_TIMESTAMP) and then will stamp the packets. c sock. , ioctl(2) returns -1 with errno set to ENOENT). And ktime_get_real is also used by __net_timestamp in socket Jul 31, 2012 · It's hard to know what you are doing wrong, since we cannot see your code. 4 内核版本3. e. Linux supports TCP timestamping, and I tried to write some demo code to get any timestamp for TCP packet. This raw socket may appear in netstat(8) output with a zero inode. So, for example, if you have an appropriate solarflare card, then setting the options will cause the card to timestamp. They use ktime_get_real. The documentation describes them as follows: SO_TIMESTAMP; Generates a timestamp for each incoming packet in (not necessarily monotonic Mar 22, 2020 · 1. 1. Just to be sore I researched documentation on ktime accessors that ktime_get_real is the same as CLOCK_REALTIME. com 17/1 Nov 9, 2012 · When reading from a (non-stream) socket in Linux, I can get the (hardware-generated) timestamp of the last received message via a ioctl(sock, SIOCGSTAMP, &tv). Recently linux added more SO_TIMESTAMPING_* options to provide even more precise timestamps from NIC cards that support them. A socket which has had accept(2) or connect(2) successfully called on it is fully specified and may transmit data. Nov 16, 2017 · Like I say in comment the use of SOF_TIMESTAMPING_SOFTWARE and SOF_TIMESTAMPING_RAW_HARDWARE is necessary because if I understand correctly the documentation, some bits are to generate the timestamp and some bits are here to report them in control message: Sep 26, 2019 · 环境：centos7. - As soon as the driver has sent the packet and/or obtained a hardware time stamp for it, it passes the time stamp back by calling skb_hwtstamp_tx() with the original skb, the raw hardware time stamp. The cmsg_data field is a struct timeval indicating the reception time of the last packet passed to the user in this call. SEE ALSO top ip(7), rdisc(8) RFC 792 for a description of the ICMP protocol. - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin. c. As soon as the driver has sent the packet and/or obtained a hardware time stamp for it, it passes the time stamp back by calling skb_tstamp_tx() with the original skb, the raw hardware time stamp. Data cannot be transmitted on listening or not yet connected sockets. 8. 1. 我一直在尝试获取Linux（内核4. 1 SO_TIMESTAMP (also SO_TIMESTAMP_OLD and SO_TIMESTAMP_NEW)¶ This socket option enables timestamping of datagrams on the reception path. 4)给我发送和接收UDP数据报的时间戳，但没有成功。我已经阅读了原始内核文档()，以及许多示例和许多堆栈溢出条目。我可以在发送者和接收者之间发送数据报，没有问题。但是我无法得到发送或接收数据报的时间戳，我也不知道自己做错了什么。一件奇怪的事情是，当我 Sep 28, 2023 · Given Linux is used and packet timestamping is enabled with SO_TIMESTAMPING for a TCP socket and we read now some data, what timestamp will be reported if the byte-stream which we read was merged out of multiple TCP packets (which each have different timestamps)? I assume the newest one, but maybe there is some more magic involved in this? The 64-bit timestamp returned by ICMP_TIMESTAMP is in milliseconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC). Here's a bit from the kernel docs on it: These timestamps are returned in a control message with cmsg_level SOL_SOCKET, cmsg_type SCM_TIMESTAMPING, and payload of type struct scm_timestamping { struct timespec ts[3]; }; The structure can return up to Linux provides a socket control message to add timestamp ancillary data to the the socket, which can be controlled by 2 different socket options SO_TIMESTAMP and SO_TIMESTAMPNS, using setsockopt(2). hjbuf gvf tyaywvx kakvtz npcy imstl plg wciw cyhnyz hxi ipmju bgjpaqk czhd ccrmg wcb