macro: add LXC_AUDS_ADDR_LEN

src/lxc/commands.c

@@ -1239,7 +1239,7 @@ out_close:
 int lxc_cmd_init(const char *name, const char *lxcpath, const char *suffix)
 {
 	int fd, len, ret;
-	char path[sizeof(((struct sockaddr_un *)0)->sun_path)] = {0};
+	char path[LXC_AUDS_ADDR_LEN] = {0};
 	char *offset = &path[1];
 
 	/* -2 here because this is an abstract unix socket so it needs a

src/lxc/commands_utils.c

@@ -162,7 +162,7 @@ int lxc_cmd_connect(const char *name, const char *lxcpath,
 		    const char *hashed_sock_name, const char *suffix)
 {
 	int ret, client_fd;
-	char path[sizeof(((struct sockaddr_un *)0)->sun_path)] = {0};
+	char path[LXC_AUDS_ADDR_LEN] = {0};
 	char *offset = &path[1];
 
 	/* -2 here because this is an abstract unix socket so it needs a

src/lxc/macro.h

@@ -30,6 +30,7 @@
 #include <string.h>
 #include <sys/mount.h>
 #include <sys/socket.h>
+#include <sys/un.h>
 
 /* Define __S_ISTYPE if missing from the C library. */
 #ifndef __S_ISTYPE
@@ -238,6 +239,9 @@ extern int __build_bug_on_failed;
 #define MACVLAN_MODE_PASSTHRU 8
 #endif
 
+/* Length of abstract unix domain socket socket address. */
+#define LXC_AUDS_ADDR_LEN sizeof(((struct sockaddr_un *)0)->sun_path)
+
 /* mount */
 #ifndef MS_REC
 #define MS_REC 16384