diff mbox series

[v3,03/10] libmpathutil: add support for Unix pathname sockets

Message ID 20250214221011.136762-4-mwilck@suse.com (mailing list archive)
State New
Headers show
Series multipath-tools: provide pathname and abstract sockets | expand

Commit Message

Martin Wilck Feb. 14, 2025, 10:10 p.m. UTC
Pathname sockets need to be world read/writable in order to allow regular
users to read information from multipathd. Our SO_PEERCRED permission check
will make sure that they can't make configuration changes. Also, SO_REUSEADDR
doesn't work for pathname sockets as it does for abstract Unix sockets. A
possibly pre-existing socket file must be removed before trying to recreate it.

Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 libmpathutil/uxsock.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
diff mbox series

Patch

diff --git a/libmpathutil/uxsock.c b/libmpathutil/uxsock.c
index 12c4608..889d7a1 100644
--- a/libmpathutil/uxsock.c
+++ b/libmpathutil/uxsock.c
@@ -62,6 +62,11 @@  int ux_socket_listen(const char *name)
 		return fd;
 	}
 #endif
+
+	/* This is after the PID check, so unlinking should be fine */
+	if (name[0] != '@' && unlink(name) == -1 && errno != ENOENT)
+		condlog(1, "Failed to unlink %s", name);
+
 	fd = socket(AF_LOCAL, SOCK_STREAM, 0);
 	if (fd == -1) {
 		condlog(3, "Couldn't create ux_socket, error %d", errno);
@@ -75,6 +80,14 @@  int ux_socket_listen(const char *name)
 		return -1;
 	}
 
+	/*
+	 * Socket needs to have rw permissions for everone.
+	 * SO_PEERCRED makes sure that only root can modify things.
+	 */
+	if (name[0] != '@' &&
+	    chmod(name, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH) == -1)
+		condlog(3, "failed to set permissions on %s: %s", name, strerror(errno));
+
 	if (listen(fd, 10) == -1) {
 		condlog(3, "Couldn't listen to ux_socket, error %d", errno);
 		close(fd);