socket.7: Add some SO_TIMESTAMPNS details.

Note the kernel version that added SO_TIMESTAMPNS,
and (from the kernel commit) note tha SO_TIMESTAMPNS and
SO_TIMESTAMP are mutually exclusive.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man7/socket.7 b/man7/socket.7
index ee551dbcfdf76376f21ef316180771d6a6902d9e..87a4c2364d8257278af43b30a9b53056ffe118d8 100644 (file)
--- a/man7/socket.7
+++ b/man7/socket.7
@@ -941,7 +941,8 @@ See
 .BR cmsg (3)
 for details on control messages.
 .TP
-.B SO_TIMESTAMPNS
+.BR SO_TIMESTAMPNS " (since Linux 2.6.22)"
+.\" commit 92f37fd2ee805aa77925c1e64fd56088b46094fc
 Enable or disable the receiving of the
 .B SO_TIMESTAMPNS
 control message.
@@ -958,6 +959,12 @@ The clock used for the timestamp is
 See
 .BR cmsg (3)
 for details on control messages.
+.IP
+A socket cannot mix
+.B SO_TIMESTAMP
+and
+.BR SO_TIMESTAMPNS:
+the two modes are mutually exclusive.
 .TP
 .B SO_TYPE
 Gets the socket type as an integer (e.g.,