From 5b5cb1958062e4bad3f724437ef7448272a2f2ba Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Sun, 8 Jul 2018 22:06:51 +0200 Subject: [PATCH] unix.7: When sending ancillary data, only one item of each type may be sent Verified by experiment and reading the source code (although the SCM_RIGHTS case is not so clear to me in the source code). Signed-off-by: Michael Kerrisk --- man7/unix.7 | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/man7/unix.7 b/man7/unix.7 index c08218702..cbc0b314d 100644 --- a/man7/unix.7 +++ b/man7/unix.7 @@ -436,6 +436,10 @@ message, the .B SO_PASSCRED option must be enabled on the socket. .PP +When sending ancillary data with +.BR sendmsg (2), +only one item of each of the above types may be included in the sent message. +.PP If the space allocated for receiving incoming ancillary data is too small, then the ancillary data is truncated to the number of headers that will fit in the supplied buffer (or, in the case of an