xref: /openbsd-src/usr.bin/tmux/tmux.c (revision 348c998d4bcf878c63affeafd7473e1f6ca69ace)
1 /* $OpenBSD: tmux.c,v 1.57 2009/11/10 18:53:11 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 <paths.h>
25 #include <pwd.h>
26 #include <signal.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <syslog.h>
30 #include <unistd.h>
31 
32 #include "tmux.h"
33 
34 #ifdef DEBUG
35 extern char	*malloc_options;
36 #endif
37 
38 char		*cfg_file;
39 struct options	 global_s_options;	/* session options */
40 struct options	 global_w_options;	/* window options */
41 struct environ	 global_environ;
42 
43 int		 debug_level;
44 int		 be_quiet;
45 time_t		 start_time;
46 char		*socket_path;
47 int		 login_shell;
48 
49 __dead void	 usage(void);
50 void	 	 fill_session(struct msg_command_data *);
51 char 		*makesockpath(const char *);
52 __dead void	 shell_exec(const char *, const char *);
53 
54 struct imsgbuf	*main_ibuf;
55 struct event	 main_ev_sigterm;
56 int	         main_exitval;
57 
58 void		 main_set_signals(void);
59 void		 main_clear_signals(void);
60 void		 main_signal(int, short, unused void *);
61 void		 main_callback(int, short, void *);
62 void		 main_dispatch(const char *);
63 
64 __dead void
65 usage(void)
66 {
67 	fprintf(stderr,
68 	    "usage: %s [-28lquv] [-c shell-command] [-f file] [-L socket-name]\n"
69 	    "            [-S socket-path] [command [flags]]\n",
70 	    __progname);
71 	exit(1);
72 }
73 
74 void
75 logfile(const char *name)
76 {
77 	char	*path;
78 
79 	log_close();
80 	if (debug_level > 0) {
81 		xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
82 		log_open_file(debug_level, path);
83 		xfree(path);
84 	}
85 }
86 
87 const char *
88 getshell(void)
89 {
90 	struct passwd	*pw;
91 	const char	*shell;
92 
93 	shell = getenv("SHELL");
94 	if (checkshell(shell))
95 		return (shell);
96 
97 	pw = getpwuid(getuid());
98 	if (pw != NULL && checkshell(pw->pw_shell))
99 		return (pw->pw_shell);
100 
101 	return (_PATH_BSHELL);
102 }
103 
104 int
105 checkshell(const char *shell)
106 {
107 	if (shell == NULL || *shell == '\0' || areshell(shell))
108 		return (0);
109 	if (access(shell, X_OK) != 0)
110 		return (0);
111 	return (1);
112 }
113 
114 int
115 areshell(const char *shell)
116 {
117 	const char	*progname, *ptr;
118 
119 	if ((ptr = strrchr(shell, '/')) != NULL)
120 		ptr++;
121 	else
122 		ptr = shell;
123 	progname = __progname;
124 	if (*progname == '-')
125 		progname++;
126 	if (strcmp(ptr, progname) == 0)
127 		return (1);
128 	return (0);
129 }
130 
131 void
132 fill_session(struct msg_command_data *data)
133 {
134 	char		*env, *ptr1, *ptr2, buf[256];
135 	size_t		 len;
136 	const char	*errstr;
137 	long long	 ll;
138 
139 	data->pid = -1;
140 	if ((env = getenv("TMUX")) == NULL)
141 		return;
142 
143 	if ((ptr2 = strrchr(env, ',')) == NULL || ptr2 == env)
144 		return;
145 	for (ptr1 = ptr2 - 1; ptr1 > env && *ptr1 != ','; ptr1--)
146 		;
147 	if (*ptr1 != ',')
148 		return;
149 	ptr1++;
150 	ptr2++;
151 
152 	len = ptr2 - ptr1 - 1;
153 	if (len > (sizeof buf) - 1)
154 		return;
155 	memcpy(buf, ptr1, len);
156 	buf[len] = '\0';
157 
158 	ll = strtonum(buf, 0, LONG_MAX, &errstr);
159 	if (errstr != NULL)
160 		return;
161 	data->pid = ll;
162 
163 	ll = strtonum(ptr2, 0, UINT_MAX, &errstr);
164 	if (errstr != NULL)
165 		return;
166 	data->idx = ll;
167 }
168 
169 char *
170 makesockpath(const char *label)
171 {
172 	char		base[MAXPATHLEN], *path;
173 	struct stat	sb;
174 	u_int		uid;
175 
176 	uid = getuid();
177 	xsnprintf(base, MAXPATHLEN, "%s/tmux-%d", _PATH_TMP, uid);
178 
179 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
180 		return (NULL);
181 
182 	if (lstat(base, &sb) != 0)
183 		return (NULL);
184 	if (!S_ISDIR(sb.st_mode)) {
185 		errno = ENOTDIR;
186 		return (NULL);
187 	}
188 	if (sb.st_uid != uid || (sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
189 		errno = EACCES;
190 		return (NULL);
191 	}
192 
193 	xasprintf(&path, "%s/%s", base, label);
194 	return (path);
195 }
196 
197 __dead void
198 shell_exec(const char *shell, const char *shellcmd)
199 {
200 	const char	*shellname, *ptr;
201 	char		*argv0;
202 
203 	ptr = strrchr(shell, '/');
204 	if (ptr != NULL && *(ptr + 1) != '\0')
205 		shellname = ptr + 1;
206 	else
207 		shellname = shell;
208 	if (login_shell)
209 		xasprintf(&argv0, "-%s", shellname);
210 	else
211 		xasprintf(&argv0, "%s", shellname);
212 	setenv("SHELL", shell, 1);
213 
214 	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
215 	fatal("execl failed");
216 }
217 
218 int
219 main(int argc, char **argv)
220 {
221 	struct cmd_list		*cmdlist;
222  	struct cmd		*cmd;
223 	enum msgtype		 msg;
224 	struct passwd		*pw;
225 	struct options		*so, *wo;
226 	struct keylist		*keylist;
227 	struct msg_command_data	 cmddata;
228 	char			*s, *shellcmd, *path, *label, *home, *cause;
229 	char			 cwd[MAXPATHLEN], **var;
230 	void			*buf;
231 	size_t			 len;
232 	int	 		 opt, flags, cmdflags = 0;
233 	short		 	 events;
234 
235 #ifdef DEBUG
236 	malloc_options = (char *) "AFGJPX";
237 #endif
238 
239 	flags = 0;
240 	shellcmd = label = path = NULL;
241 	login_shell = (**argv == '-');
242 	while ((opt = getopt(argc, argv, "28c:df:lL:qS:uUv")) != -1) {
243 		switch (opt) {
244 		case '2':
245 			flags |= IDENTIFY_256COLOURS;
246 			flags &= ~IDENTIFY_88COLOURS;
247 			break;
248 		case '8':
249 			flags |= IDENTIFY_88COLOURS;
250 			flags &= ~IDENTIFY_256COLOURS;
251 			break;
252 		case 'c':
253 			if (shellcmd != NULL)
254 				xfree(shellcmd);
255 			shellcmd = xstrdup(optarg);
256 			break;
257 		case 'f':
258 			if (cfg_file != NULL)
259 				xfree(cfg_file);
260 			cfg_file = xstrdup(optarg);
261 			break;
262 		case 'l':
263 			login_shell = 1;
264 			break;
265 		case 'L':
266 			if (label != NULL)
267 				xfree(label);
268 			label = xstrdup(optarg);
269 			break;
270 		case 'q':
271 			be_quiet = 1;
272 			break;
273 		case 'S':
274 			if (path != NULL)
275 				xfree(path);
276 			path = xstrdup(optarg);
277 			break;
278 		case 'u':
279 			flags |= IDENTIFY_UTF8;
280 			break;
281 		case 'v':
282 			debug_level++;
283 			break;
284 		default:
285 			usage();
286 		}
287 	}
288 	argc -= optind;
289 	argv += optind;
290 
291 	if (shellcmd != NULL && argc != 0)
292 		usage();
293 
294 	log_open_tty(debug_level);
295 
296 	if (!(flags & IDENTIFY_UTF8)) {
297 		/*
298 		 * If the user has set whichever of LC_ALL, LC_CTYPE or LANG
299 		 * exist (in that order) to contain UTF-8, it is a safe
300 		 * assumption that either they are using a UTF-8 terminal, or
301 		 * if not they know that output from UTF-8-capable programs may
302 		 * be wrong.
303 		 */
304 		if ((s = getenv("LC_ALL")) == NULL) {
305 			if ((s = getenv("LC_CTYPE")) == NULL)
306 				s = getenv("LANG");
307 		}
308 		if (s != NULL && (strcasestr(s, "UTF-8") != NULL ||
309 		    strcasestr(s, "UTF8") != NULL))
310 			flags |= IDENTIFY_UTF8;
311 	}
312 
313 	environ_init(&global_environ);
314  	for (var = environ; *var != NULL; var++)
315 		environ_put(&global_environ, *var);
316 
317 	options_init(&global_s_options, NULL);
318 	so = &global_s_options;
319 	options_set_number(so, "base-index", 0);
320 	options_set_number(so, "bell-action", BELL_ANY);
321 	options_set_number(so, "buffer-limit", 9);
322 	options_set_string(so, "default-command", "%s", "");
323 	options_set_string(so, "default-shell", "%s", getshell());
324 	options_set_string(so, "default-terminal", "screen");
325 	options_set_number(so, "display-panes-colour", 4);
326 	options_set_number(so, "display-panes-time", 1000);
327 	options_set_number(so, "display-time", 750);
328 	options_set_number(so, "history-limit", 2000);
329 	options_set_number(so, "lock-after-time", 0);
330 	options_set_string(so, "lock-command", "lock -np");
331 	options_set_number(so, "lock-server", 1);
332 	options_set_number(so, "message-attr", 0);
333 	options_set_number(so, "message-bg", 3);
334 	options_set_number(so, "message-fg", 0);
335 	options_set_number(so, "mouse-select-pane", 0);
336 	options_set_number(so, "repeat-time", 500);
337 	options_set_number(so, "set-remain-on-exit", 0);
338 	options_set_number(so, "set-titles", 0);
339 	options_set_string(so, "set-titles-string", "#S:#I:#W - \"#T\"");
340 	options_set_number(so, "status", 1);
341 	options_set_number(so, "status-attr", 0);
342 	options_set_number(so, "status-bg", 2);
343 	options_set_number(so, "status-fg", 0);
344 	options_set_number(so, "status-interval", 15);
345 	options_set_number(so, "status-justify", 0);
346 	options_set_number(so, "status-keys", MODEKEY_EMACS);
347 	options_set_string(so, "status-left", "[#S]");
348 	options_set_number(so, "status-left-attr", 0);
349 	options_set_number(so, "status-left-bg", 8);
350 	options_set_number(so, "status-left-fg", 8);
351 	options_set_number(so, "status-left-length", 10);
352 	options_set_string(so, "status-right", "\"#22T\" %%H:%%M %%d-%%b-%%y");
353 	options_set_number(so, "status-right-attr", 0);
354 	options_set_number(so, "status-right-bg", 8);
355 	options_set_number(so, "status-right-fg", 8);
356 	options_set_number(so, "status-right-length", 40);
357 	options_set_string(so, "terminal-overrides",
358 	    "*88col*:colors=88,*256col*:colors=256");
359 	options_set_string(so, "update-environment", "DISPLAY "
360 	    "WINDOWID SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION");
361 	options_set_number(so, "visual-activity", 0);
362 	options_set_number(so, "visual-bell", 0);
363 	options_set_number(so, "visual-content", 0);
364 
365 	keylist = xmalloc(sizeof *keylist);
366 	ARRAY_INIT(keylist);
367 	ARRAY_ADD(keylist, '\002');
368 	options_set_data(so, "prefix", keylist, xfree);
369 
370 	options_init(&global_w_options, NULL);
371 	wo = &global_w_options;
372 	options_set_number(wo, "aggressive-resize", 0);
373 	options_set_number(wo, "automatic-rename", 1);
374 	options_set_number(wo, "clock-mode-colour", 4);
375 	options_set_number(wo, "clock-mode-style", 1);
376 	options_set_number(wo, "force-height", 0);
377 	options_set_number(wo, "force-width", 0);
378 	options_set_number(wo, "main-pane-height", 24);
379 	options_set_number(wo, "main-pane-width", 81);
380 	options_set_number(wo, "mode-attr", 0);
381 	options_set_number(wo, "mode-bg", 3);
382 	options_set_number(wo, "mode-fg", 0);
383 	options_set_number(wo, "mode-keys", MODEKEY_EMACS);
384 	options_set_number(wo, "mode-mouse", 0);
385 	options_set_number(wo, "monitor-activity", 0);
386 	options_set_string(wo, "monitor-content", "%s", "");
387 	options_set_number(wo, "window-status-attr", 0);
388 	options_set_number(wo, "window-status-bg", 8);
389 	options_set_number(wo, "window-status-current-attr", 0);
390 	options_set_number(wo, "window-status-current-bg", 8);
391 	options_set_number(wo, "window-status-current-fg", 8);
392 	options_set_number(wo, "window-status-fg", 8);
393 	options_set_number(wo, "xterm-keys", 1);
394  	options_set_number(wo, "remain-on-exit", 0);
395 	options_set_number(wo, "synchronize-panes", 0);
396 
397  	if (flags & IDENTIFY_UTF8) {
398 		options_set_number(so, "status-utf8", 1);
399 		options_set_number(wo, "utf8", 1);
400 	} else {
401 		options_set_number(so, "status-utf8", 0);
402 		options_set_number(wo, "utf8", 0);
403 	}
404 
405 	if (getcwd(cwd, sizeof cwd) == NULL) {
406 		pw = getpwuid(getuid());
407 		if (pw->pw_dir != NULL && *pw->pw_dir != '\0')
408 			strlcpy(cwd, pw->pw_dir, sizeof cwd);
409 		else
410 			strlcpy(cwd, "/", sizeof cwd);
411 	}
412 	options_set_string(so, "default-path", "%s", cwd);
413 
414 	if (cfg_file == NULL) {
415 		home = getenv("HOME");
416 		if (home == NULL || *home == '\0') {
417 			pw = getpwuid(getuid());
418 			if (pw != NULL)
419 				home = pw->pw_dir;
420 		}
421 		xasprintf(&cfg_file, "%s/%s", home, DEFAULT_CFG);
422 		if (access(cfg_file, R_OK) != 0) {
423 			xfree(cfg_file);
424 			cfg_file = NULL;
425 		}
426 	} else {
427 		if (access(cfg_file, R_OK) != 0) {
428 			log_warn("%s", cfg_file);
429 			exit(1);
430 		}
431 	}
432 
433 	if (label == NULL)
434 		label = xstrdup("default");
435 	if (path == NULL && (path = makesockpath(label)) == NULL) {
436 		log_warn("can't create socket");
437 		exit(1);
438 	}
439 	xfree(label);
440 
441 	if (shellcmd != NULL) {
442 		msg = MSG_SHELL;
443 		buf = NULL;
444 		len = 0;
445 	} else {
446 		fill_session(&cmddata);
447 
448 		cmddata.argc = argc;
449 		if (cmd_pack_argv(
450 		    argc, argv, cmddata.argv, sizeof cmddata.argv) != 0) {
451 			log_warnx("command too long");
452 			exit(1);
453 		}
454 
455 		msg = MSG_COMMAND;
456 		buf = &cmddata;
457 		len = sizeof cmddata;
458 	}
459 
460 	if (shellcmd != NULL)
461 		cmdflags |= CMD_STARTSERVER;
462 	else if (argc == 0)	/* new-session is the default */
463 		cmdflags |= CMD_STARTSERVER|CMD_SENDENVIRON;
464 	else {
465 		/*
466 		 * It sucks parsing the command string twice (in client and
467 		 * later in server) but it is necessary to get the start server
468 		 * flag.
469 		 */
470 		if ((cmdlist = cmd_list_parse(argc, argv, &cause)) == NULL) {
471 			log_warnx("%s", cause);
472 			exit(1);
473 		}
474 		cmdflags &= ~CMD_STARTSERVER;
475 		TAILQ_FOREACH(cmd, cmdlist, qentry) {
476 			if (cmd->entry->flags & CMD_STARTSERVER)
477 				cmdflags |= CMD_STARTSERVER;
478 			if (cmd->entry->flags & CMD_SENDENVIRON)
479 				cmdflags |= CMD_SENDENVIRON;
480 		}
481 		cmd_list_free(cmdlist);
482 	}
483 
484 	if ((main_ibuf = client_init(path, cmdflags, flags)) == NULL)
485 		exit(1);
486 	xfree(path);
487 
488 	event_init();
489 
490  	imsg_compose(main_ibuf, msg, PROTOCOL_VERSION, -1, -1, buf, len);
491 
492 	main_set_signals();
493 
494 	events = EV_READ;
495 	if (main_ibuf->w.queued > 0)
496 		events |= EV_WRITE;
497 	event_once(main_ibuf->fd, events, main_callback, shellcmd, NULL);
498 
499 	main_exitval = 0;
500 	event_dispatch();
501 
502 	main_clear_signals();
503 
504 	client_main();	/* doesn't return */
505 }
506 
507 void
508 main_set_signals(void)
509 {
510 	struct sigaction	sigact;
511 
512 	memset(&sigact, 0, sizeof sigact);
513 	sigemptyset(&sigact.sa_mask);
514 	sigact.sa_flags = SA_RESTART;
515 	sigact.sa_handler = SIG_IGN;
516 	if (sigaction(SIGINT, &sigact, NULL) != 0)
517 		fatal("sigaction failed");
518 	if (sigaction(SIGPIPE, &sigact, NULL) != 0)
519 		fatal("sigaction failed");
520 	if (sigaction(SIGUSR1, &sigact, NULL) != 0)
521 		fatal("sigaction failed");
522 	if (sigaction(SIGUSR2, &sigact, NULL) != 0)
523 		fatal("sigaction failed");
524 	if (sigaction(SIGTSTP, &sigact, NULL) != 0)
525 		fatal("sigaction failed");
526 
527 	signal_set(&main_ev_sigterm, SIGTERM, main_signal, NULL);
528 	signal_add(&main_ev_sigterm, NULL);
529 }
530 
531 void
532 main_clear_signals(void)
533 {
534 	struct sigaction	sigact;
535 
536 	memset(&sigact, 0, sizeof sigact);
537 	sigemptyset(&sigact.sa_mask);
538 	sigact.sa_flags = SA_RESTART;
539 	sigact.sa_handler = SIG_DFL;
540 	if (sigaction(SIGINT, &sigact, NULL) != 0)
541 		fatal("sigaction failed");
542 	if (sigaction(SIGPIPE, &sigact, NULL) != 0)
543 		fatal("sigaction failed");
544 	if (sigaction(SIGUSR1, &sigact, NULL) != 0)
545 		fatal("sigaction failed");
546 	if (sigaction(SIGUSR2, &sigact, NULL) != 0)
547 		fatal("sigaction failed");
548 	if (sigaction(SIGTSTP, &sigact, NULL) != 0)
549 		fatal("sigaction failed");
550 
551 	event_del(&main_ev_sigterm);
552 }
553 
554 void
555 main_signal(int sig, unused short events, unused void *data)
556 {
557 	switch (sig) {
558 	case SIGTERM:
559 		exit(1);
560 	}
561 }
562 
563 void
564 main_callback(unused int fd, short events, void *data)
565 {
566 	char	*shellcmd = data;
567 
568 	if (events & EV_READ)
569 		main_dispatch(shellcmd);
570 
571 	if (events & EV_WRITE) {
572 		if (msgbuf_write(&main_ibuf->w) < 0)
573 			fatalx("msgbuf_write failed");
574 	}
575 
576 	events = EV_READ;
577 	if (main_ibuf->w.queued > 0)
578 		events |= EV_WRITE;
579 	event_once(main_ibuf->fd, events, main_callback, shellcmd, NULL);
580 }
581 
582 void
583 main_dispatch(const char *shellcmd)
584 {
585 	struct imsg		imsg;
586 	ssize_t			n, datalen;
587 	struct msg_print_data	printdata;
588 	struct msg_shell_data	shelldata;
589 
590 	if ((n = imsg_read(main_ibuf)) == -1 || n == 0)
591 		fatalx("imsg_read failed");
592 
593 	for (;;) {
594 		if ((n = imsg_get(main_ibuf, &imsg)) == -1)
595 			fatalx("imsg_get failed");
596 		if (n == 0)
597 			return;
598 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
599 
600 		switch (imsg.hdr.type) {
601 		case MSG_EXIT:
602 		case MSG_SHUTDOWN:
603 			if (datalen != 0)
604 				fatalx("bad MSG_EXIT size");
605 
606 			exit(main_exitval);
607 		case MSG_ERROR:
608 		case MSG_PRINT:
609 			if (datalen != sizeof printdata)
610 				fatalx("bad MSG_PRINT size");
611 			memcpy(&printdata, imsg.data, sizeof printdata);
612 			printdata.msg[(sizeof printdata.msg) - 1] = '\0';
613 
614 			log_info("%s", printdata.msg);
615 			if (imsg.hdr.type == MSG_ERROR)
616 				main_exitval = 1;
617 			break;
618 		case MSG_READY:
619 			if (datalen != 0)
620 				fatalx("bad MSG_READY size");
621 
622 			event_loopexit(NULL);	/* move to client_main() */
623 			break;
624 		case MSG_VERSION:
625 			if (datalen != 0)
626 				fatalx("bad MSG_VERSION size");
627 
628 			log_warnx("protocol version mismatch (client %u, "
629 			    "server %u)", PROTOCOL_VERSION, imsg.hdr.peerid);
630 			exit(1);
631 		case MSG_SHELL:
632 			if (datalen != sizeof shelldata)
633 				fatalx("bad MSG_SHELL size");
634 			memcpy(&shelldata, imsg.data, sizeof shelldata);
635 			shelldata.shell[(sizeof shelldata.shell) - 1] = '\0';
636 
637 			main_clear_signals();
638 
639 			shell_exec(shelldata.shell, shellcmd);
640 		default:
641 			fatalx("unexpected message");
642 		}
643 
644 		imsg_free(&imsg);
645 	}
646 }
647