xref: /openbsd-src/usr.bin/tmux/tmux.c (revision cafa7ad7114db288b66668a13cf68b29c09293fd)
1 /* $OpenBSD: tmux.c,v 1.124 2013/10/10 12:12:08 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/stat.h>
21 
22 #include <errno.h>
23 #include <event.h>
24 #include <fcntl.h>
25 #include <locale.h>
26 #include <paths.h>
27 #include <pwd.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <unistd.h>
31 
32 #include "tmux.h"
33 
34 #ifdef DEBUG
35 extern char	*malloc_options;
36 #endif
37 
38 struct options	 global_options;	/* server options */
39 struct options	 global_s_options;	/* session options */
40 struct options	 global_w_options;	/* window options */
41 struct environ	 global_environ;
42 
43 struct event_base *ev_base;
44 
45 char		*cfg_file;
46 char		*shell_cmd;
47 int		 debug_level;
48 time_t		 start_time;
49 char		 socket_path[MAXPATHLEN];
50 int		 login_shell;
51 char		*environ_path;
52 pid_t		 environ_pid = -1;
53 int		 environ_session_id = -1;
54 
55 __dead void	 usage(void);
56 void	 	 parseenvironment(void);
57 char 		*makesocketpath(const char *);
58 
59 __dead void
60 usage(void)
61 {
62 	fprintf(stderr,
63 	    "usage: %s [-28lquv] [-c shell-command] [-f file] [-L socket-name]\n"
64 	    "            [-S socket-path] [command [flags]]\n",
65 	    __progname);
66 	exit(1);
67 }
68 
69 void
70 logfile(const char *name)
71 {
72 	char	*path;
73 
74 	if (debug_level > 0) {
75 		xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
76 		log_open(debug_level, path);
77 		free(path);
78 	}
79 }
80 
81 const char *
82 getshell(void)
83 {
84 	struct passwd	*pw;
85 	const char	*shell;
86 
87 	shell = getenv("SHELL");
88 	if (checkshell(shell))
89 		return (shell);
90 
91 	pw = getpwuid(getuid());
92 	if (pw != NULL && checkshell(pw->pw_shell))
93 		return (pw->pw_shell);
94 
95 	return (_PATH_BSHELL);
96 }
97 
98 int
99 checkshell(const char *shell)
100 {
101 	if (shell == NULL || *shell == '\0' || *shell != '/')
102 		return (0);
103 	if (areshell(shell))
104 		return (0);
105 	if (access(shell, X_OK) != 0)
106 		return (0);
107 	return (1);
108 }
109 
110 int
111 areshell(const char *shell)
112 {
113 	const char	*progname, *ptr;
114 
115 	if ((ptr = strrchr(shell, '/')) != NULL)
116 		ptr++;
117 	else
118 		ptr = shell;
119 	progname = __progname;
120 	if (*progname == '-')
121 		progname++;
122 	if (strcmp(ptr, progname) == 0)
123 		return (1);
124 	return (0);
125 }
126 
127 const char*
128 get_full_path(const char *wd, const char *path)
129 {
130 	int		 fd;
131 	static char	 newpath[MAXPATHLEN];
132 	const char	*retval;
133 
134 	fd = open(".", O_RDONLY);
135 	if (fd == -1)
136 		return (NULL);
137 
138 	retval = NULL;
139 	if (chdir(wd) == 0) {
140 		if (realpath(path, newpath) == 0)
141 			retval = newpath;
142 	}
143 
144 	if (fchdir(fd) != 0)
145 		chdir("/");
146 	close(fd);
147 
148 	return (retval);
149 }
150 
151 void
152 parseenvironment(void)
153 {
154 	char	*env, path[256];
155 	long	 pid;
156 	int	 id;
157 
158 	if ((env = getenv("TMUX")) == NULL)
159 		return;
160 
161 	if (sscanf(env, "%255[^,],%ld,%d", path, &pid, &id) != 3)
162 		return;
163 	environ_path = xstrdup(path);
164 	environ_pid = pid;
165 	environ_session_id = id;
166 }
167 
168 char *
169 makesocketpath(const char *label)
170 {
171 	char		base[MAXPATHLEN], realbase[MAXPATHLEN], *path, *s;
172 	struct stat	sb;
173 	u_int		uid;
174 
175 	uid = getuid();
176 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
177 		xsnprintf(base, sizeof base, "%s/", s);
178 	else if ((s = getenv("TMPDIR")) != NULL && *s != '\0')
179 		xsnprintf(base, sizeof base, "%s/tmux-%u", s, uid);
180 	else
181 		xsnprintf(base, sizeof base, "%s/tmux-%u", _PATH_TMP, uid);
182 
183 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
184 		return (NULL);
185 
186 	if (lstat(base, &sb) != 0)
187 		return (NULL);
188 	if (!S_ISDIR(sb.st_mode)) {
189 		errno = ENOTDIR;
190 		return (NULL);
191 	}
192 	if (sb.st_uid != uid || (!S_ISDIR(sb.st_mode) &&
193 		sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
194 		errno = EACCES;
195 		return (NULL);
196 	}
197 
198 	if (realpath(base, realbase) == NULL)
199 		strlcpy(realbase, base, sizeof realbase);
200 
201 	xasprintf(&path, "%s/%s", realbase, label);
202 	return (path);
203 }
204 
205 void
206 setblocking(int fd, int state)
207 {
208 	int mode;
209 
210 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
211 		if (!state)
212 			mode |= O_NONBLOCK;
213 		else
214 			mode &= ~O_NONBLOCK;
215 		fcntl(fd, F_SETFL, mode);
216 	}
217 }
218 
219 __dead void
220 shell_exec(const char *shell, const char *shellcmd)
221 {
222 	const char	*shellname, *ptr;
223 	char		*argv0;
224 
225 	ptr = strrchr(shell, '/');
226 	if (ptr != NULL && *(ptr + 1) != '\0')
227 		shellname = ptr + 1;
228 	else
229 		shellname = shell;
230 	if (login_shell)
231 		xasprintf(&argv0, "-%s", shellname);
232 	else
233 		xasprintf(&argv0, "%s", shellname);
234 	setenv("SHELL", shell, 1);
235 
236 	setblocking(STDIN_FILENO, 1);
237 	setblocking(STDOUT_FILENO, 1);
238 	setblocking(STDERR_FILENO, 1);
239 	closefrom(STDERR_FILENO + 1);
240 
241 	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
242 	fatal("execl failed");
243 }
244 
245 int
246 main(int argc, char **argv)
247 {
248 	struct passwd	*pw;
249 	char		*s, *path, *label, *home, **var;
250 	int	 	 opt, flags, quiet, keys;
251 
252 #ifdef DEBUG
253 	malloc_options = (char *) "AFGJPX";
254 #endif
255 
256 	setlocale(LC_TIME, "");
257 
258 	quiet = flags = 0;
259 	label = path = NULL;
260 	login_shell = (**argv == '-');
261 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) {
262 		switch (opt) {
263 		case '2':
264 			flags |= CLIENT_256COLOURS;
265 			break;
266 		case 'c':
267 			free(shell_cmd);
268 			shell_cmd = xstrdup(optarg);
269 			break;
270 		case 'C':
271 			if (flags & CLIENT_CONTROL)
272 				flags |= CLIENT_CONTROLCONTROL;
273 			else
274 				flags |= CLIENT_CONTROL;
275 			break;
276 		case 'f':
277 			free(cfg_file);
278 			cfg_file = xstrdup(optarg);
279 			break;
280 		case 'l':
281 			login_shell = 1;
282 			break;
283 		case 'L':
284 			free(label);
285 			label = xstrdup(optarg);
286 			break;
287 		case 'q':
288 			quiet = 1;
289 			break;
290 		case 'S':
291 			free(path);
292 			path = xstrdup(optarg);
293 			break;
294 		case 'u':
295 			flags |= CLIENT_UTF8;
296 			break;
297 		case 'v':
298 			debug_level++;
299 			break;
300 		default:
301 			usage();
302 		}
303 	}
304 	argc -= optind;
305 	argv += optind;
306 
307 	if (shell_cmd != NULL && argc != 0)
308 		usage();
309 
310 	if (!(flags & CLIENT_UTF8)) {
311 		/*
312 		 * If the user has set whichever of LC_ALL, LC_CTYPE or LANG
313 		 * exist (in that order) to contain UTF-8, it is a safe
314 		 * assumption that either they are using a UTF-8 terminal, or
315 		 * if not they know that output from UTF-8-capable programs may
316 		 * be wrong.
317 		 */
318 		if ((s = getenv("LC_ALL")) == NULL || *s == '\0') {
319 			if ((s = getenv("LC_CTYPE")) == NULL || *s == '\0')
320 				s = getenv("LANG");
321 		}
322 		if (s != NULL && (strcasestr(s, "UTF-8") != NULL ||
323 		    strcasestr(s, "UTF8") != NULL))
324 			flags |= CLIENT_UTF8;
325 	}
326 
327 	environ_init(&global_environ);
328 	for (var = environ; *var != NULL; var++)
329 		environ_put(&global_environ, *var);
330 
331 	options_init(&global_options, NULL);
332 	options_table_populate_tree(server_options_table, &global_options);
333 	options_set_number(&global_options, "quiet", quiet);
334 
335 	options_init(&global_s_options, NULL);
336 	options_table_populate_tree(session_options_table, &global_s_options);
337 	options_set_string(&global_s_options, "default-shell", "%s", getshell());
338 
339 	options_init(&global_w_options, NULL);
340 	options_table_populate_tree(window_options_table, &global_w_options);
341 
342 	/* Enable UTF-8 if the first client is on UTF-8 terminal. */
343 	if (flags & CLIENT_UTF8) {
344 		options_set_number(&global_s_options, "status-utf8", 1);
345 		options_set_number(&global_s_options, "mouse-utf8", 1);
346 		options_set_number(&global_w_options, "utf8", 1);
347 	}
348 
349 	/* Override keys to vi if VISUAL or EDITOR are set. */
350 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
351 		if (strrchr(s, '/') != NULL)
352 			s = strrchr(s, '/') + 1;
353 		if (strstr(s, "vi") != NULL)
354 			keys = MODEKEY_VI;
355 		else
356 			keys = MODEKEY_EMACS;
357 		options_set_number(&global_s_options, "status-keys", keys);
358 		options_set_number(&global_w_options, "mode-keys", keys);
359 	}
360 
361 	/* Locate the configuration file. */
362 	if (cfg_file == NULL) {
363 		home = getenv("HOME");
364 		if (home == NULL || *home == '\0') {
365 			pw = getpwuid(getuid());
366 			if (pw != NULL)
367 				home = pw->pw_dir;
368 		}
369 		xasprintf(&cfg_file, "%s/.tmux.conf", home);
370 		if (access(cfg_file, R_OK) != 0 && errno == ENOENT) {
371 			free(cfg_file);
372 			cfg_file = NULL;
373 		}
374 	}
375 
376 	/*
377 	 * Figure out the socket path. If specified on the command-line with -S
378 	 * or -L, use it, otherwise try $TMUX or assume -L default.
379 	 */
380 	parseenvironment();
381 	if (path == NULL) {
382 		/* If no -L, use the environment. */
383 		if (label == NULL) {
384 			if (environ_path != NULL)
385 				path = xstrdup(environ_path);
386 			else
387 				label = xstrdup("default");
388 		}
389 
390 		/* -L or default set. */
391 		if (label != NULL) {
392 			if ((path = makesocketpath(label)) == NULL) {
393 				fprintf(stderr, "can't create socket: %s\n",
394 					strerror(errno));
395 				exit(1);
396 			}
397 		}
398 	}
399 	free(label);
400 	strlcpy(socket_path, path, sizeof socket_path);
401 	free(path);
402 
403 	/* Set process title. */
404 	setproctitle("%s (%s)", __progname, socket_path);
405 
406 	/* Pass control to the client. */
407 	ev_base = event_init();
408 	exit(client_main(argc, argv, flags));
409 }
410