From 6e0c8e1ae292e567ba6260d9a6c0b771629a89e3 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Mon, 3 Aug 2020 22:13:02 +0000
Subject: [PATCH] Add SOL_LOCAL symbolic constant for unix socket option level.

The constant seems to exists on MacOS X >= 10.8.

Requested by:	swills
Reviewed by:	allanjude, kevans
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D25933
---
 lib/libc/gen/getpeereid.c | 2 +-
 share/man/man4/unix.4     | 6 ++++--
 sys/kern/uipc_usrreq.c    | 2 +-
 sys/sys/un.h              | 2 ++
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/libc/gen/getpeereid.c b/lib/libc/gen/getpeereid.c
index 530ae0e6100e..86396d359ba3 100644
--- a/lib/libc/gen/getpeereid.c
+++ b/lib/libc/gen/getpeereid.c
@@ -47,7 +47,7 @@ getpeereid(int s, uid_t *euid, gid_t *egid)
 	int error;
 
 	xuclen = sizeof(xuc);
-	error = _getsockopt(s, 0, LOCAL_PEERCRED, &xuc, &xuclen);
+	error = _getsockopt(s, SOL_LOCAL, LOCAL_PEERCRED, &xuc, &xuclen);
 	if (error != 0)
 		return (error);
 	if (xuc.cr_version != XUCRED_VERSION) {
diff --git a/share/man/man4/unix.4 b/share/man/man4/unix.4
index 8832e5eff870..569e6dd25208 100644
--- a/share/man/man4/unix.4
+++ b/share/man/man4/unix.4
@@ -28,7 +28,7 @@
 .\"     @(#)unix.4	8.1 (Berkeley) 6/9/93
 .\" $FreeBSD$
 .\"
-.Dd August 19, 2018
+.Dd August 3, 2020
 .Dt UNIX 4
 .Os
 .Sh NAME
@@ -195,7 +195,9 @@ The sending process could have exited and its process ID already been
 reused for a new process.
 .Sh SOCKET OPTIONS
 .Tn UNIX
-domain sockets support a number of socket options which can be set with
+domain sockets support a number of socket options for the options level
+.Dv SOL_LOCAL ,
+which can be set with
 .Xr setsockopt 2
 and tested with
 .Xr getsockopt 2 :
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index efd592f82fe2..6261135f64ad 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -1470,7 +1470,7 @@ uipc_ctloutput(struct socket *so, struct sockopt *sopt)
 	struct xucred xu;
 	int error, optval;
 
-	if (sopt->sopt_level != 0)
+	if (sopt->sopt_level != SOL_LOCAL)
 		return (EINVAL);
 
 	unp = sotounpcb(so);
diff --git a/sys/sys/un.h b/sys/sys/un.h
index 3c408628ce0a..3a011aeef635 100644
--- a/sys/sys/un.h
+++ b/sys/sys/un.h
@@ -62,6 +62,8 @@ struct sockaddr_un {
 
 #if __BSD_VISIBLE
 
+#define	SOL_LOCAL		0	/* Options for local socket */
+
 /* Socket options. */
 #define	LOCAL_PEERCRED		1	/* retrieve peer credentials */
 #define	LOCAL_CREDS		2	/* pass credentials to receiver */