[PATCH 22/24] man/man7/unix.7: Remove mentions of unsupported out-of-band messaging

["Günther Noack" <gnoack3000@gmail.com>]

Limited support for MSG_OOB was added in linux.git 314001f0bf92
(2021-08-04; "af_unix: Add OOB support").

Its removal was discussed in [1] but has so far not happened.

The support is conditional on the CONFIG_AF_UNIX_OOB kconfig option,
so stating that it is supported would also be wrong.

Link: [1] <https://lore.kernel.org/all/20240409225209.58102-1-kuniyu@amazon.com/>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
---

Notes:
    This one is authored from scratch by hand; in the initial version, the
    LLM spotted the inaccuracy and then proceeded to document the feature
    in full glory -- I think it would be the wrong call to propagate the
    use of a feature whose removal has been discussed already due to low
    usage and security issues. (See cover letter as well)

 man/man7/unix.7 | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/man/man7/unix.7 b/man/man7/unix.7
index 8d1a53948f5b..bcb58336a1d8 100644
--- a/man/man7/unix.7
+++ b/man/man7/unix.7
@@ -401,14 +401,6 @@ The change to 5 bytes came in Linux 2.3.15.)
 The following paragraphs describe domain-specific details and
 unsupported features of the sockets API for UNIX domain sockets on Linux.
 .P
-UNIX domain sockets do not support the transmission of
-out-of-band data (the
-.B MSG_OOB
-flag for
-.BR send (2)
-and
-.BR recv (2)).
-.P
 The
 .BR send (2)
 .B MSG_MORE
@@ -780,7 +772,8 @@ Socket operation needs a target address, but the socket is not connected.
 .TP
 .B EOPNOTSUPP
 Stream operation called on non-stream oriented socket or tried to
-use the out-of-band data option.
+use the out-of-band data option
+when it isn't supported.
 .TP
 .B EPERM
 The sender passed invalid credentials in the
@@ -883,8 +876,6 @@ at least one byte of nonancillary data in the same
 or
 .BR recvmsg (2)
 call.
-.P
-UNIX domain stream sockets do not support the notion of out-of-band data.
 .\"
 .SH BUGS
 When binding a socket to an address,
-- 
2.56.0