===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/server.c,v
retrieving revision 1.177
retrieving revision 1.178
diff -u -r1.177 -r1.178
--- src/usr.bin/tmux/server.c	2017/10/12 11:32:27	1.177
+++ src/usr.bin/tmux/server.c	2017/12/19 15:00:39	1.178
@@ -1,4 +1,4 @@
-/* $OpenBSD: server.c,v 1.177 2017/10/12 11:32:27 nicm Exp $ */
+/* $OpenBSD: server.c,v 1.178 2017/12/19 15:00:39 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -50,7 +50,6 @@
 
 struct cmd_find_state	 marked_pane;
 
-static int	server_create_socket(void);
 static int	server_loop(void);
 static void	server_send_exit(void);
 static void	server_accept(int, short, void *);
@@ -99,41 +98,64 @@
 
 /* Create server socket. */
 static int
-server_create_socket(void)
+server_create_socket(char **cause)
 {
 	struct sockaddr_un	sa;
 	size_t			size;
 	mode_t			mask;
-	int			fd;
+	int			fd, saved_errno;
 
 	memset(&sa, 0, sizeof sa);
 	sa.sun_family = AF_UNIX;
 	size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path);
 	if (size >= sizeof sa.sun_path) {
 		errno = ENAMETOOLONG;
-		return (-1);
+		goto fail;
 	}
 	unlink(sa.sun_path);
 
 	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
-		return (-1);
+		goto fail;
 
 	mask = umask(S_IXUSR|S_IXGRP|S_IRWXO);
-	if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) == -1) {
+	if (bind(fd, (struct sockaddr *)&sa, sizeof sa) == -1) {
+		saved_errno = errno;
 		close(fd);
-		return (-1);
+		errno = saved_errno;
+		goto fail;
 	}
 	umask(mask);
 
 	if (listen(fd, 128) == -1) {
+		saved_errno = errno;
 		close(fd);
-		return (-1);
+		errno = saved_errno;
+		goto fail;
 	}
 	setblocking(fd, 0);
 
 	return (fd);
+
+fail:
+	if (cause != NULL) {
+		xasprintf(cause, "error creating %s (%s)", socket_path,
+		    strerror(errno));
+	}
+	return (-1);
 }
 
+/* Server error callback. */
+static enum cmd_retval
+server_start_error(struct cmdq_item *item, void *data)
+{
+	char	*error = data;
+
+	cmdq_error(item, "%s", error);
+	free(error);
+
+	return (CMD_RETURN_NORMAL);
+}
+
 /* Fork new server. */
 int
 server_start(struct tmuxproc *client, struct event_base *base, int lockfd,
@@ -142,6 +164,8 @@
 	int		 pair[2];
 	struct job	*job;
 	sigset_t	 set, oldset;
+	struct client	*c;
+	char		*cause = NULL;
 
 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
 		fatal("socketpair failed");
@@ -183,11 +207,10 @@
 
 	gettimeofday(&start_time, NULL);
 
-	server_fd = server_create_socket();
-	if (server_fd == -1)
-		fatal("couldn't create socket");
-	server_update_socket();
-	server_client_create(pair[1]);
+	server_fd = server_create_socket(&cause);
+	if (server_fd != -1)
+		server_update_socket();
+	c = server_client_create(pair[1]);
 
 	if (lockfd >= 0) {
 		unlink(lockfile);
@@ -195,6 +218,11 @@
 		close(lockfd);
 	}
 
+	if (cause != NULL) {
+		cmdq_append(c, cmdq_get_callback(server_start_error, cause));
+		c->flags |= CLIENT_EXIT;
+	}
+
 	start_cfg();
 
 	server_add_accept(0);
@@ -375,7 +403,7 @@
 		break;
 	case SIGUSR1:
 		event_del(&server_ev_accept);
-		fd = server_create_socket();
+		fd = server_create_socket(NULL);
 		if (fd != -1) {
 			close(server_fd);
 			server_fd = fd;