From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Martin Wilck <mwilck@suse.com>
Date: Fri, 14 Feb 2025 21:57:02 +0100
Subject: [PATCH] multipath-tools: add helper mpath_fill_sockaddr__()

Create a static new helper function which is used by both libmpathcmd
and libmpathutil and fills in the socket address name from the compile-time
default. The function is able to handle both abstract and pathname sockets,
but more changes are needed to make the latter actually work.

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 Makefile.inc                      |  2 +-
 libmpathcmd/mpath_cmd.c           | 11 +++--------
 libmpathcmd/mpath_fill_sockaddr.c | 30 ++++++++++++++++++++++++++++++
 libmultipath/uxsock.c             | 15 ++++++---------
 4 files changed, 40 insertions(+), 18 deletions(-)
 create mode 100644 libmpathcmd/mpath_fill_sockaddr.c

diff --git a/Makefile.inc b/Makefile.inc
index 3746ceee..308f0da0 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -82,7 +82,7 @@ includedir	= $(prefix)/usr/include
 pkgconfdir	= $(usrlibdir)/pkgconfig
 runtimedir	= /$(RUN)
 
-abstract_socket := /org/kernel/linux/storage/multipathd
+abstract_socket := @/org/kernel/linux/storage/multipathd
 
 GZIP		= gzip -9 -c
 RM		= rm -f
diff --git a/libmpathcmd/mpath_cmd.c b/libmpathcmd/mpath_cmd.c
index 60b2d965..146e790d 100644
--- a/libmpathcmd/mpath_cmd.c
+++ b/libmpathcmd/mpath_cmd.c
@@ -24,11 +24,13 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <poll.h>
+#include <stddef.h>
 #include <string.h>
 #include <errno.h>
 #include <fcntl.h>
 
 #include "mpath_cmd.h"
+#include "mpath_fill_sockaddr.c"
 
 /*
  * keep reading until its all read
@@ -101,14 +103,6 @@ int __mpath_connect(int nonblocking)
 	struct sockaddr_un addr;
 	int flags = 0;
 
-	memset(&addr, 0, sizeof(addr));
-	addr.sun_family = AF_LOCAL;
-	addr.sun_path[0] = '\0';
-	strncpy(&addr.sun_path[1], DEFAULT_SOCKET, sizeof(addr.sun_path) - 1);
-	len = strlen(DEFAULT_SOCKET) + 1 + sizeof(sa_family_t);
-	if (len > sizeof(struct sockaddr_un))
-		len = sizeof(struct sockaddr_un);
-
 	fd = socket(AF_LOCAL, SOCK_STREAM, 0);
 	if (fd == -1)
 		return -1;
@@ -119,6 +113,7 @@ int __mpath_connect(int nonblocking)
 			(void)fcntl(fd, F_SETFL, flags|O_NONBLOCK);
 	}
 
+	len = mpath_fill_sockaddr__(&addr, DEFAULT_SOCKET);
 	if (connect(fd, (struct sockaddr *)&addr, len) == -1) {
 		int err = errno;
 
diff --git a/libmpathcmd/mpath_fill_sockaddr.c b/libmpathcmd/mpath_fill_sockaddr.c
new file mode 100644
index 00000000..86c118d4
--- /dev/null
+++ b/libmpathcmd/mpath_fill_sockaddr.c
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2025 SUSE LLC
+ * SPDX-license-identifier: LGPL-2.1-or-newer
+ */
+
+static size_t mpath_fill_sockaddr__(struct sockaddr_un *addr, const char *name)
+{
+	size_t len;
+
+	addr->sun_family = AF_LOCAL;
+
+	if (name[0] != '@') {
+		/* Pathname socket. This should be NULL-terminated. */
+		strncpy(&addr->sun_path[0], name, sizeof(addr->sun_path) - 1);
+		addr->sun_path[sizeof(addr->sun_path) - 1] = '\0';
+		len = offsetof(struct sockaddr_un, sun_path) + strlen(name) + 1;
+	} else {
+		addr->sun_path[0] = '\0';
+		/*
+		 * The abstract socket's name doesn't need to be NULL terminated.
+		 * Actually, a trailing NULL would be considered part of the socket name.
+		 */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstringop-truncation"
+		strncpy(&addr->sun_path[1], &name[1], sizeof(addr->sun_path) - 1);
+#pragma GCC diagnostic pop
+		len = offsetof(struct sockaddr_un, sun_path) + strlen(name);
+	}
+	return len > sizeof(*addr) ? sizeof(*addr) : len;
+}
diff --git a/libmultipath/uxsock.c b/libmultipath/uxsock.c
index 6adeedfc..de1a21a3 100644
--- a/libmultipath/uxsock.c
+++ b/libmultipath/uxsock.c
@@ -6,12 +6,15 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <stddef.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
 #include <sys/un.h>
 #include <poll.h>
 #include <signal.h>
@@ -34,6 +37,8 @@
 static int _recv_packet(int fd, char **buf, unsigned int timeout,
 			ssize_t limit);
 
+#include "../libmpathcmd/mpath_fill_sockaddr.c"
+
 /*
  * create a unix domain socket and start listening on it
  * return a file descriptor open on the socket
@@ -64,15 +69,7 @@ int ux_socket_listen(const char *name)
 		return -1;
 	}
 
-	memset(&addr, 0, sizeof(addr));
-	addr.sun_family = AF_LOCAL;
-	addr.sun_path[0] = '\0';
-	len = strlen(name) + 1;
-	if (len >= sizeof(addr.sun_path))
-		len = sizeof(addr.sun_path) - 1;
-	memcpy(&addr.sun_path[1], name, len);
-
-	len += sizeof(sa_family_t);
+	len = mpath_fill_sockaddr__(&addr, name);
 	if (bind(fd, (struct sockaddr *)&addr, len) == -1) {
 		condlog(3, "Couldn't bind to ux_socket, error %d", errno);
 		close(fd);