Sockets in /tmp are now created in a subdirectory named, tmux-UID, eg

tmux-1000. The default socket is thus /tmp/tmux-UID/default. To start a
separate server, the new -L command line option should be used: this creates a
socket in the same directory with a different name ("-L main" will create
socket called "main"). -S should only be used to place the socket outside
/tmp. This makes sockets a little more secure and a bit more convenient to use
multiple servers.

CHANGES

@@ -1,3 +1,13 @@
+27 March 2009
+
+* Sockets in /tmp are now created in a subdirectory named, tmux-UID, eg
+  tmux-1000. The default socket is thus /tmp/tmux-UID/default. To start a
+  separate server, the new -L command line option should be used: this creates
+  a socket in the same directory with a different name ("-L main" will create
+  socket called "main"). -S should only be used to place the socket outside
+  /tmp. This makes sockets a little more secure and a bit more convenient to
+  use multiple servers.
+
 21 March 2009
 
 * New session flag "set-remain-on-exit" to set remain-on-exit flag for new
@@ -1132,7 +1142,7 @@
   (including mutt, emacs). No status bar yet and no key remapping or other
   customisation.
 
-$Id: CHANGES,v 1.259 2009-03-21 12:44:05 nicm Exp $
+$Id: CHANGES,v 1.260 2009-03-27 15:57:09 nicm Exp $
 
  LocalWords:  showw utf UTF fulvio ciriaco joshe OSC APC gettime abc DEF OA clr
  LocalWords:  rivo nurges lscm Erdely eol smysession mysession ek dstname RB ms

TODO

@@ -96,3 +96,4 @@
 - refer to windows by name etc (duplicates? fnmatch?)
 - n/p repeat is annoying, turn off
 - repeat should be a key flag and should be configurable (bind -r)
+- document -L and update socket path bits in tmux.1

server.c

@@ -1,4 +1,4 @@
-/* $Id: server.c,v 1.127 2009-03-27 08:46:02 nicm Exp $ */
+/* $Id: server.c,v 1.128 2009-03-27 15:57:10 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -43,7 +43,7 @@
 /* Client list. */
 struct clients	 clients;
 
-int		 server_main(const char *, int);
+int		 server_main(int);
 void		 server_shutdown(void);
 void		 server_child_signal(void);
 void		 server_fill_windows(struct pollfd **);
@@ -59,7 +59,7 @@ void		 server_check_redraw(struct client *);
 void		 server_redraw_locked(struct client *);
 void		 server_check_timers(struct client *);
 void		 server_second_timers(void);
-int		 server_update_socket(const char *);
+int		 server_update_socket(void);
 
 /* Create a new client. */
 struct client *
@@ -127,6 +127,9 @@ server_start(const char *path)
 	mode_t			mask;
 	int		   	n, fd, pair[2], mode;
 	char		       *cause;
+#ifndef NO_SETPROCTITLE
+	char			rpathbuf[MAXPATHLEN];
+#endif
 
 	/* The first client is special and gets a socketpair; create it. */
 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
@@ -170,17 +173,20 @@ server_start(const char *path)
 		log_warnx("%s", cause);
 		exit(1);
 	}
-
 	logfile("server");
-#ifndef NO_SETPROCTITLE
+
-	setproctitle("server (%s)", path);
-#endif
 	log_debug("server started, pid %ld", (long) getpid());
 	log_debug("socket path %s", socket_path);
+
+#ifndef NO_SETPROCTITLE
+	if (realpath(socket_path, rpathbuf) == NULL)
+		strlcpy(rpathbuf, socket_path, sizeof rpathbuf);
+	setproctitle("server (%s)", rpathbuf);
+#endif
 	
 	memset(&sa, 0, sizeof sa);
 	sa.sun_family = AF_UNIX;
-	size = strlcpy(sa.sun_path, path, sizeof sa.sun_path);
+	size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path);
 	if (size >= sizeof sa.sun_path) {
 		errno = ENAMETOOLONG;
 		fatal("socket failed");
@@ -207,7 +213,7 @@ server_start(const char *path)
 
 	server_create_client(pair[1]);
 
-	n = server_main(path, fd);
+	n = server_main(fd);
 #ifdef DEBUG
 	xmalloc_report(getpid(), "server");
 #endif
@@ -216,7 +222,7 @@ server_start(const char *path)
 
 /* Main server loop. */
 int
-server_main(const char *srv_path, int srv_fd)
+server_main(int srv_fd)
 {
 	struct window	*w;
 	struct pollfd	*pfds, *pfd;
@@ -263,7 +269,7 @@ server_main(const char *srv_path, int srv_fd)
 
 		/* Update socket permissions. */
 		xtimeout = INFTIM;
-		if (sigterm || server_update_socket(srv_path) != 0)
+		if (sigterm || server_update_socket() != 0)
 			xtimeout = 100;
 
 		/* Do the poll. */
@@ -337,7 +343,9 @@ server_main(const char *srv_path, int srv_fd)
 	key_bindings_free();
 
 	close(srv_fd);
-	unlink(srv_path);
+
+	unlink(socket_path);
+	xfree(socket_path);
 
 	options_free(&global_options);
 	options_free(&global_window_options);
@@ -996,7 +1004,7 @@ server_second_timers(void)
 
 /* Update socket execute permissions based on whether sessions are attached. */
 int
-server_update_socket(const char *path)
+server_update_socket()
 {
 	struct session	*s;
 	u_int		 i;
@@ -1015,9 +1023,9 @@ server_update_socket(const char *path)
 	if (n != last) {
 		last = n;
 		if (n != 0)
-			chmod(path, S_IRWXU);
+			chmod(socket_path, S_IRWXU);
 		else
-			chmod(path, S_IRUSR|S_IWUSR);
+			chmod(socket_path, S_IRUSR|S_IWUSR);
 	}
 
 	return (n);

tmux.c

@@ -1,4 +1,4 @@
-/* $Id: tmux.c,v 1.109 2009-03-21 12:44:06 nicm Exp $ */
+/* $Id: tmux.c,v 1.110 2009-03-27 15:57:10 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -17,6 +17,7 @@
  */
 
 #include <sys/types.h>
+#include <sys/stat.h>
 
 #include <errno.h>
 #include <pwd.h>
@@ -58,9 +59,10 @@ time_t		 server_activity;
 int		 debug_level;
 int		 be_quiet;
 time_t		 start_time;
-const char	*socket_path;
+char		*socket_path;
 
 __dead void	 usage(void);
+char 		*makesockpath(const char *);
 
 #ifdef NO_PROGNAME
 const char      *__progname = "tmux";
@@ -173,6 +175,34 @@ sigreset(void)
 		fatal("sigaction failed");
 }
 
+char *
+makesockpath(const char *label)
+{
+	char		base[MAXPATHLEN], *path;
+	struct stat	sb;
+	u_int		uid;
+
+	uid = getuid();
+	xsnprintf(base, MAXPATHLEN, "%s/%s-%d", _PATH_TMP, __progname, uid);
+
+	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
+		return (NULL);
+
+	if (lstat(base, &sb) != 0)
+		return (NULL);
+	if (!S_ISDIR(sb.st_mode) || sb.st_uid != uid) {
+		errno = EACCES;
+		return (NULL);
+	}
+	if ((sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
+		errno = EACCES;
+		return (NULL);
+	}
+
+	xasprintf(&path, "%s/%s", base, label);
+	return (path);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -185,13 +215,13 @@ main(int argc, char **argv)
 	struct hdr	 	 hdr;
 	const char		*shell;
 	struct passwd		*pw;
-	char			*path, *cause, *home, *pass = NULL;
+	char			*path, *label, *cause, *home, *pass = NULL;
-	char			 rpath[MAXPATHLEN], cwd[MAXPATHLEN];
+	char			 cwd[MAXPATHLEN]; 
 	int	 		 retcode, opt, flags, unlock, start_server;
 
 	unlock = flags = 0;
-	path = NULL;
+	label = path = NULL;
-        while ((opt = getopt(argc, argv, "28df:qS:uUVv")) != -1) {
+        while ((opt = getopt(argc, argv, "28df:L:qS:uUVv")) != -1) {
                 switch (opt) {
 		case '2':
 			flags |= IDENTIFY_256COLOURS;
@@ -204,7 +234,22 @@ main(int argc, char **argv)
 		case 'f':
 			cfg_file = xstrdup(optarg);
 			break;
+		case 'L':
+			if (path != NULL) {
+				log_warnx("-L and -S cannot be used together");
+				exit(1);
+			}
+			if (label != NULL)
+				xfree(label);
+			label = xstrdup(optarg);
+			break;
 		case 'S':
+			if (label != NULL) {
+				log_warnx("-L and -S cannot be used together");
+				exit(1);
+			}
+			if (path != NULL)
+				xfree(path);
 			path = xstrdup(optarg);
 			break;
 		case 'q':
@@ -299,26 +344,13 @@ main(int argc, char **argv)
 		}
 	}
 
-	if (path == NULL) {
+	if (label == NULL)
-		xasprintf(&path,
+		label = xstrdup("default");
-		    "%s/%s-%lu", _PATH_TMP, __progname, (u_long) getuid());
+	if (path == NULL && (path = makesockpath(label)) == NULL) {
+		log_warn("can't create socket");
+		exit(1);
 	}
-	if (realpath(path, rpath) == NULL) {
+	xfree(label);
-		if (errno != ENOENT) {
-			log_warn("%s", path);
-			exit(1);
-		}
-		/*
-		 * Linux appears to fill in the buffer fine but then returns
-		 * ENOENT if the file doesn't exist. But since it returns an
-		 * error, we can't rely on the buffer. Grr.
-		 */
-		if (strlcpy(rpath, path, sizeof rpath) >= sizeof rpath) {
-			log_warnx("%s: %s", path, strerror(ENAMETOOLONG));
-			exit(1);
-		}
-	}
-	xfree(path);
 
 	shell = getenv("SHELL");
 	if (shell == NULL || *shell == '\0') {
@@ -374,8 +406,9 @@ main(int argc, char **argv)
 	}
 	
  	memset(&cctx, 0, sizeof cctx);
-	if (client_init(rpath, &cctx, start_server, flags) != 0)
+	if (client_init(path, &cctx, start_server, flags) != 0)
 		exit(1);
+	xfree(path);
 
 	b = buffer_create(BUFSIZ);
 	if (unlock) {

tmux.h

@@ -1,4 +1,4 @@
-/* $Id: tmux.h,v 1.280 2009-03-21 12:44:06 nicm Exp $ */
+/* $Id: tmux.h,v 1.281 2009-03-27 15:57:10 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -1022,7 +1022,7 @@ extern time_t	 server_activity;
 extern int	 debug_level;
 extern int	 be_quiet;
 extern time_t	 start_time;
-extern const char *socket_path;
+extern char 	*socket_path;
 void		 logfile(const char *);
 void		 siginit(void);
 void		 sigreset(void);