[PATCH] socket: enable nanosecond resolution receive timestamp on FreeBSD
Josef 'Jeff' Sipek <[email protected]>
| Newsgroups | gmane.comp.time.chrony.user |
|---|---|
| Message-ID | <ZNOEghRB9xvueVKc@satis> |
This is just a quick patch to get better resolution receive timestamps from the kernel. As far as I can tell, the timestamps are supposed to be using the unix epoch. If not, I can switch it up from SO_TS_REALTIME to SO_TS_MONOTONIC which does marginally less work but its epoch isn't January 1, 1970 - it's essentially the uptime. Let me know if I missed anything. Jeff.
0001-socket-enable-nanosecond-resolution-receive-timestam.patch
(text/x-diff, 1.8 KB)
From a5a967a270233afcbdb7e5374ad9990362a884f8 Mon Sep 17 00:00:00 2001 From: Josef 'Jeff' Sipek <[email protected]> Date: Wed, 9 Aug 2023 07:58:38 -0400 Subject: [PATCH] socket: enable nanosecond resolution receive timestamp on FreeBSD FreeBSD allows switching the receive timestamp format to struct timespec by setting the SO_TS_CLOCK socket option to SO_TS_REALTIME after enabling SO_TIMESTAMP. If successful, the kernel then starts adding SCM_REALTIME control messages instead of SCM_TIMESTAMP. --- socket.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/socket.c b/socket.c index 8a5d046..f4bae6d 100644 --- a/socket.c +++ b/socket.c @@ -869,6 +869,11 @@ process_header(struct msghdr *msg, int msg_length, int sock_fd, int flags, memcpy(&message->timestamp.kernel, CMSG_DATA(cmsg), sizeof (message->timestamp.kernel)); } #endif +#ifdef SCM_REALTIME + else if (match_cmsg(cmsg, SOL_SOCKET, SCM_REALTIME, sizeof (message->timestamp.kernel))) { + memcpy(&message->timestamp.kernel, CMSG_DATA(cmsg), sizeof (message->timestamp.kernel)); + } +#endif #ifdef HAVE_LINUX_TIMESTAMPING #ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO else if (match_cmsg(cmsg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO, @@ -1386,8 +1391,16 @@ SCK_EnableKernelRxTimestamping(int sock_fd) return 1; #endif #ifdef SO_TIMESTAMP - if (SCK_SetIntOption(sock_fd, SOL_SOCKET, SO_TIMESTAMP, 1)) + if (SCK_SetIntOption(sock_fd, SOL_SOCKET, SO_TIMESTAMP, 1)) { +#if defined(SO_TS_CLOCK) && defined(SO_TS_REALTIME) + /* + * We don't care about the return value - we'll get either a + * SCM_REALTIME (if we succeded) or a SCM_TIMESTAMP (if we failed). + */ + SCK_SetIntOption(sock_fd, SOL_SOCKET, SO_TS_CLOCK, SO_TS_REALTIME); +#endif return 1; + } #endif return 0; -- 2.41.0