On Wed, 2019-09-11 at 19:48 +0000, Alan Somers wrote: > Author: asomers > Date: Wed Sep 11 19:48:32 2019 > New Revision: 352231 > URL: https://svnweb.freebsd.org/changeset/base/352231 > > Log: > getsockopt.2: clarify that SO_TIMESTAMP is not 100% reliable > > When SO_TIMESTAMP is set, the kernel will attempt to attach a timestamp as > ancillary data to each IP datagram that is received on the socket. However, > it may fail, for example due to insufficient memory. In that case the > packet will still be received but not timestamp will be attached. > > Reviewed by: kib > MFC after: 3 days > Differential Revision: https://reviews.freebsd.org/D21607 > > Modified: > head/lib/libc/sys/getsockopt.2 > > Modified: head/lib/libc/sys/getsockopt.2 > ============================================================================== > --- head/lib/libc/sys/getsockopt.2 Wed Sep 11 19:29:40 2019 > (r352230) > +++ head/lib/libc/sys/getsockopt.2 Wed Sep 11 19:48:32 2019 > (r352231) > @@ -28,7 +28,7 @@ > .\" @(#)getsockopt.2 8.4 (Berkeley) 5/2/95 > .\" $FreeBSD$ > .\" > -.Dd February 10, 2019 > +.Dd September 11, 2019 > .Dt GETSOCKOPT 2 > .Os > .Sh NAME > @@ -431,7 +431,8 @@ option is enabled on a > .Dv SOCK_DGRAM > socket, the > .Xr recvmsg 2 > -call will return a timestamp corresponding to when the datagram was received. > +call may return a timestamp corresponding to when the datagram was received. > +However, it may not, for example due to a resource shortage. > The > .Va msg_control > field in the >
So I guess this actually happened to someone... is it a common thing for the timestamp to fail? I ask because ntpd relies on SO_TIMESTAMP and if this situation really happens and can persist for a long time, ntpd would effectively stop working. -- Ian _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
