[v3,09/10] libmpathcmd: honor MULTIPATH_SOCKET_NAME environment variable

Commit Message

Martin Wilck Feb. 14, 2025, 10:10 p.m. UTC

In systemd installments, users can already override the socket names
that systemd listens on. With this patch, clients using libmpathcmd
can be customized to use a non-standard socket by setting an environment
variable.

Signed-off-by: Martin Wilck <[e-mail]>
---
 libmpathcmd/mpath_cmd.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

Patch

diff --git a/libmpathcmd/mpath_cmd.c b/libmpathcmd/mpath_cmd.c
index ba5bb31..405267f 100644
--- a/libmpathcmd/mpath_cmd.c
+++ b/libmpathcmd/mpath_cmd.c
@@ -20,6 +20,7 @@ 
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
@@ -104,6 +105,7 @@  int mpath_connect__(int nonblocking)
 	int flags = 0;
 	const char *names[2] = {PATHNAME_SOCKET, ABSTRACT_SOCKET};
 	int name_idx = 0;
+	const char *env_name = getenv("MULTIPATH_SOCKET_NAME"), *name;
 
 retry:
 	fd = socket(AF_LOCAL, SOCK_STREAM, 0);
@@ -116,12 +118,13 @@  retry:
 			(void)fcntl(fd, F_SETFL, flags|O_NONBLOCK);
 	}
 
-	len = mpath_fill_sockaddr__(&addr, names[name_idx]);
+	name = env_name ? env_name : names[name_idx];
+	len = mpath_fill_sockaddr__(&addr, name);
 	if (connect(fd, (struct sockaddr *)&addr, len) == -1) {
 		int err = errno;
 
 		close(fd);
-		if (err == ECONNREFUSED && ++name_idx == 1)
+		if (name != env_name && err == ECONNREFUSED && ++name_idx == 1)
 			goto retry;
 		else {
 			errno = err;