test/zdtm/sockets_dgram: check the length of path used

Path generated in the test is copied into sun_path attribute in
struct sockaddr_un. Additional check on whether sun_path can
contain the whole path is added. It is useful because if sun_path
can only contain the first part of the path, all sockadd_un
will point to the same location, which leads to error.
Signed-off-by: Yicheng Qin <yichengq@google.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/sockets_dgram.c

@@ -73,18 +73,30 @@ int main(int argc, char *argv[])
 
 	snprintf(path, sizeof(path), "%s/%s.bound", cwd, filename);
 	unlink(path);
+	if (strlen(path) >= sizeof(name_bound.sun_path)) {
+		fail("too long path");
+		exit(1);
+	}
 
 	name_bound.sun_family = AF_UNIX;
 	strncpy(name_bound.sun_path, path, sizeof(name_bound.sun_path));
 
 	snprintf(path, sizeof(path), "%s/%s.conn", cwd, filename);
 	unlink(path);
+	if (strlen(path) >= sizeof(name_conn.sun_path)) {
+		fail("too long path");
+		exit(1);
+	}
 
 	name_conn.sun_family = AF_UNIX;
 	strncpy(name_conn.sun_path, path, sizeof(name_conn.sun_path));
 
 	snprintf(path, sizeof(path), "%s/%s.bound-conn", cwd, filename);
 	unlink(path);
+       if (strlen(path) >= sizeof(name_bound_conn.sun_path)) {
+               fail("too long path");
+               exit(1);
+       }
 
 	name_bound_conn.sun_family = AF_UNIX;
 	strncpy(name_bound_conn.sun_path, path, sizeof(name_bound_conn.sun_path));