xref: /openbsd/usr.bin/tmux/tmux.c (revision 404b540a)
1 /* $OpenBSD: tmux.c,v 1.49 2009/10/10 14:51:16 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 <paths.h>
24 #include <pwd.h>
25 #include <signal.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <syslog.h>
29 #include <unistd.h>
30 
31 #include "tmux.h"
32 
33 #ifdef DEBUG
34 const char	*malloc_options = "AFGJPX";
35 #endif
36 
37 volatile sig_atomic_t sigwinch;
38 volatile sig_atomic_t sigterm;
39 volatile sig_atomic_t sigcont;
40 volatile sig_atomic_t sigchld;
41 volatile sig_atomic_t sigusr1;
42 volatile sig_atomic_t sigusr2;
43 
44 char		*cfg_file;
45 struct options	 global_s_options;	/* session options */
46 struct options	 global_w_options;	/* window options */
47 struct environ	 global_environ;
48 
49 int		 debug_level;
50 int		 be_quiet;
51 time_t		 start_time;
52 char		*socket_path;
53 int		 login_shell;
54 
55 __dead void	 usage(void);
56 char 		*makesockpath(const char *);
57 int		 prepare_cmd(enum msgtype *, void **, size_t *, int, char **);
58 int		 dispatch_imsg(struct client_ctx *, const char *, int *);
59 __dead void	 shell_exec(const char *, const char *);
60 
61 __dead void
62 usage(void)
63 {
64 	fprintf(stderr,
65 	    "usage: %s [-28dlquv] [-c shell-command] [-f file] [-L socket-name]\n"
66 	    "            [-S socket-path] [command [flags]]\n",
67 	    __progname);
68 	exit(1);
69 }
70 
71 void
72 logfile(const char *name)
73 {
74 	char	*path;
75 
76 	log_close();
77 	if (debug_level > 0) {
78 		xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
79 		log_open_file(debug_level, path);
80 		xfree(path);
81 	}
82 }
83 
84 void
85 sighandler(int sig)
86 {
87 	int	saved_errno;
88 
89 	saved_errno = errno;
90 	switch (sig) {
91 	case SIGWINCH:
92 		sigwinch = 1;
93 		break;
94 	case SIGTERM:
95 		sigterm = 1;
96 		break;
97 	case SIGCHLD:
98 		sigchld = 1;
99 		break;
100 	case SIGCONT:
101 		sigcont = 1;
102 		break;
103 	case SIGUSR1:
104 		sigusr1 = 1;
105 		break;
106 	case SIGUSR2:
107 		sigusr2 = 1;
108 		break;
109 	}
110 	errno = saved_errno;
111 }
112 
113 void
114 siginit(void)
115 {
116 	struct sigaction	 act;
117 
118 	memset(&act, 0, sizeof act);
119 	sigemptyset(&act.sa_mask);
120 	act.sa_flags = SA_RESTART;
121 
122 	act.sa_handler = SIG_IGN;
123 	if (sigaction(SIGPIPE, &act, NULL) != 0)
124 		fatal("sigaction failed");
125 	if (sigaction(SIGINT, &act, NULL) != 0)
126 		fatal("sigaction failed");
127 	if (sigaction(SIGTSTP, &act, NULL) != 0)
128 		fatal("sigaction failed");
129 	if (sigaction(SIGQUIT, &act, NULL) != 0)
130 		fatal("sigaction failed");
131 
132 	act.sa_handler = sighandler;
133 	if (sigaction(SIGWINCH, &act, NULL) != 0)
134 		fatal("sigaction failed");
135 	if (sigaction(SIGTERM, &act, NULL) != 0)
136 		fatal("sigaction failed");
137 	if (sigaction(SIGCHLD, &act, NULL) != 0)
138 		fatal("sigaction failed");
139 	if (sigaction(SIGUSR1, &act, NULL) != 0)
140 		fatal("sigaction failed");
141 	if (sigaction(SIGUSR2, &act, NULL) != 0)
142 		fatal("sigaction failed");
143 }
144 
145 void
146 sigreset(void)
147 {
148 	struct sigaction act;
149 
150 	memset(&act, 0, sizeof act);
151 	sigemptyset(&act.sa_mask);
152 
153 	act.sa_handler = SIG_DFL;
154 	if (sigaction(SIGPIPE, &act, NULL) != 0)
155 		fatal("sigaction failed");
156 	if (sigaction(SIGUSR1, &act, NULL) != 0)
157 		fatal("sigaction failed");
158 	if (sigaction(SIGUSR2, &act, NULL) != 0)
159 		fatal("sigaction failed");
160 	if (sigaction(SIGINT, &act, NULL) != 0)
161 		fatal("sigaction failed");
162 	if (sigaction(SIGTSTP, &act, NULL) != 0)
163 		fatal("sigaction failed");
164 	if (sigaction(SIGQUIT, &act, NULL) != 0)
165 		fatal("sigaction failed");
166 	if (sigaction(SIGWINCH, &act, NULL) != 0)
167 		fatal("sigaction failed");
168 	if (sigaction(SIGTERM, &act, NULL) != 0)
169 		fatal("sigaction failed");
170 	if (sigaction(SIGCHLD, &act, NULL) != 0)
171 		fatal("sigaction failed");
172 }
173 
174 const char *
175 getshell(void)
176 {
177 	struct passwd	*pw;
178 	const char	*shell;
179 
180 	shell = getenv("SHELL");
181 	if (checkshell(shell))
182 		return (shell);
183 
184 	pw = getpwuid(getuid());
185 	if (pw != NULL && checkshell(pw->pw_shell))
186 		return (pw->pw_shell);
187 
188 	return (_PATH_BSHELL);
189 }
190 
191 int
192 checkshell(const char *shell)
193 {
194 	if (shell == NULL || *shell == '\0' || areshell(shell))
195 		return (0);
196 	if (access(shell, X_OK) != 0)
197 		return (0);
198 	return (1);
199 }
200 
201 int
202 areshell(const char *shell)
203 {
204 	const char	*progname, *ptr;
205 
206 	if ((ptr = strrchr(shell, '/')) != NULL)
207 		ptr++;
208 	else
209 		ptr = shell;
210 	progname = __progname;
211 	if (*progname == '-')
212 		progname++;
213 	if (strcmp(ptr, progname) == 0)
214 		return (1);
215 	return (0);
216 }
217 
218 char *
219 makesockpath(const char *label)
220 {
221 	char		base[MAXPATHLEN], *path;
222 	struct stat	sb;
223 	u_int		uid;
224 
225 	uid = getuid();
226 	xsnprintf(base, MAXPATHLEN, "%s/tmux-%d", _PATH_TMP, uid);
227 
228 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
229 		return (NULL);
230 
231 	if (lstat(base, &sb) != 0)
232 		return (NULL);
233 	if (!S_ISDIR(sb.st_mode)) {
234 		errno = ENOTDIR;
235 		return (NULL);
236 	}
237 	if (sb.st_uid != uid || (sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
238 		errno = EACCES;
239 		return (NULL);
240 	}
241 
242 	xasprintf(&path, "%s/%s", base, label);
243 	return (path);
244 }
245 
246 int
247 prepare_cmd(enum msgtype *msg, void **buf, size_t *len, int argc, char **argv)
248 {
249 	static struct msg_command_data	 cmddata;
250 
251 	client_fill_session(&cmddata);
252 
253 	cmddata.argc = argc;
254 	if (cmd_pack_argv(argc, argv, cmddata.argv, sizeof cmddata.argv) != 0) {
255 		log_warnx("command too long");
256 		return (-1);
257 	}
258 
259 	*buf = &cmddata;
260 	*len = sizeof cmddata;
261 
262 	*msg = MSG_COMMAND;
263 	return (0);
264 }
265 
266 int
267 main(int argc, char **argv)
268 {
269 	struct client_ctx	 cctx;
270 	struct cmd_list		*cmdlist;
271  	struct cmd		*cmd;
272 	struct pollfd	 	 pfd;
273 	enum msgtype		 msg;
274 	struct passwd		*pw;
275 	struct options		*so, *wo;
276 	struct keylist		*keylist;
277 	char			*s, *shellcmd, *path, *label, *home, *cause;
278 	char			 cwd[MAXPATHLEN], **var;
279 	void			*buf;
280 	size_t			 len;
281 	int	 		 retcode, opt, flags, cmdflags = 0;
282 	int			 nfds;
283 
284 	flags = 0;
285 	shellcmd = label = path = NULL;
286 	login_shell = (**argv == '-');
287 	while ((opt = getopt(argc, argv, "28c:df:lL:qS:uUv")) != -1) {
288 		switch (opt) {
289 		case '2':
290 			flags |= IDENTIFY_256COLOURS;
291 			flags &= ~IDENTIFY_88COLOURS;
292 			break;
293 		case '8':
294 			flags |= IDENTIFY_88COLOURS;
295 			flags &= ~IDENTIFY_256COLOURS;
296 			break;
297 		case 'c':
298 			if (shellcmd != NULL)
299 				xfree(shellcmd);
300 			shellcmd = xstrdup(optarg);
301 			break;
302 		case 'd':
303 			flags |= IDENTIFY_HASDEFAULTS;
304 			break;
305 		case 'f':
306 			if (cfg_file != NULL)
307 				xfree(cfg_file);
308 			cfg_file = xstrdup(optarg);
309 			break;
310 		case 'l':
311 			login_shell = 1;
312 			break;
313 		case 'L':
314 			if (label != NULL)
315 				xfree(label);
316 			label = xstrdup(optarg);
317 			break;
318 		case 'q':
319 			be_quiet = 1;
320 			break;
321 		case 'S':
322 			if (path != NULL)
323 				xfree(path);
324 			path = xstrdup(optarg);
325 			break;
326 		case 'u':
327 			flags |= IDENTIFY_UTF8;
328 			break;
329 		case 'v':
330 			debug_level++;
331 			break;
332                 default:
333 			usage();
334                 }
335         }
336 	argc -= optind;
337 	argv += optind;
338 
339 	if (shellcmd != NULL && argc != 0)
340 		usage();
341 
342 	log_open_tty(debug_level);
343 	siginit();
344 
345 	if (!(flags & IDENTIFY_UTF8)) {
346 		/*
347 		 * If the user has set whichever of LC_ALL, LC_CTYPE or LANG
348 		 * exist (in that order) to contain UTF-8, it is a safe
349 		 * assumption that either they are using a UTF-8 terminal, or
350 		 * if not they know that output from UTF-8-capable programs may
351 		 * be wrong.
352 		 */
353 		if ((s = getenv("LC_ALL")) == NULL) {
354 			if ((s = getenv("LC_CTYPE")) == NULL)
355 				s = getenv("LANG");
356 		}
357 		if (s != NULL && (strcasestr(s, "UTF-8") != NULL ||
358 		    strcasestr(s, "UTF8") != NULL))
359 			flags |= IDENTIFY_UTF8;
360 	}
361 
362 	environ_init(&global_environ);
363  	for (var = environ; *var != NULL; var++)
364 		environ_put(&global_environ, *var);
365 
366 	options_init(&global_s_options, NULL);
367 	so = &global_s_options;
368 	options_set_number(so, "base-index", 0);
369 	options_set_number(so, "bell-action", BELL_ANY);
370 	options_set_number(so, "buffer-limit", 9);
371 	options_set_string(so, "default-command", "%s", "");
372 	options_set_string(so, "default-shell", "%s", getshell());
373 	options_set_string(so, "default-terminal", "screen");
374 	options_set_number(so, "display-panes-colour", 4);
375 	options_set_number(so, "display-panes-time", 1000);
376 	options_set_number(so, "display-time", 750);
377 	options_set_number(so, "history-limit", 2000);
378 	options_set_number(so, "lock-after-time", 0);
379 	options_set_string(so, "lock-command", "lock -np");
380 	options_set_number(so, "lock-server", 1);
381 	options_set_number(so, "message-attr", 0);
382 	options_set_number(so, "message-bg", 3);
383 	options_set_number(so, "message-fg", 0);
384 	options_set_number(so, "mouse-select-pane", 0);
385 	options_set_number(so, "repeat-time", 500);
386 	options_set_number(so, "set-remain-on-exit", 0);
387 	options_set_number(so, "set-titles", 0);
388 	options_set_string(so, "set-titles-string", "#S:#I:#W - \"#T\"");
389 	options_set_number(so, "status", 1);
390 	options_set_number(so, "status-attr", 0);
391 	options_set_number(so, "status-bg", 2);
392 	options_set_number(so, "status-fg", 0);
393 	options_set_number(so, "status-interval", 15);
394 	options_set_number(so, "status-justify", 0);
395 	options_set_number(so, "status-keys", MODEKEY_EMACS);
396 	options_set_string(so, "status-left", "[#S]");
397 	options_set_number(so, "status-left-attr", 0);
398 	options_set_number(so, "status-left-bg", 8);
399 	options_set_number(so, "status-left-fg", 8);
400 	options_set_number(so, "status-left-length", 10);
401 	options_set_string(so, "status-right", "\"#22T\" %%H:%%M %%d-%%b-%%y");
402 	options_set_number(so, "status-right-attr", 0);
403 	options_set_number(so, "status-right-bg", 8);
404 	options_set_number(so, "status-right-fg", 8);
405 	options_set_number(so, "status-right-length", 40);
406 	options_set_string(so, "terminal-overrides",
407 	    "*88col*:colors=88,*256col*:colors=256");
408 	options_set_string(so, "update-environment", "DISPLAY "
409 	    "WINDOWID SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID SSH_CONNECTION");
410 	options_set_number(so, "visual-activity", 0);
411 	options_set_number(so, "visual-bell", 0);
412 	options_set_number(so, "visual-content", 0);
413 
414 	keylist = xmalloc(sizeof *keylist);
415 	ARRAY_INIT(keylist);
416 	ARRAY_ADD(keylist, '\002');
417 	options_set_data(so, "prefix", keylist, xfree);
418 
419 	options_init(&global_w_options, NULL);
420 	wo = &global_w_options;
421 	options_set_number(wo, "aggressive-resize", 0);
422 	options_set_number(wo, "automatic-rename", 1);
423 	options_set_number(wo, "clock-mode-colour", 4);
424 	options_set_number(wo, "clock-mode-style", 1);
425 	options_set_number(wo, "force-height", 0);
426 	options_set_number(wo, "force-width", 0);
427 	options_set_number(wo, "main-pane-height", 24);
428 	options_set_number(wo, "main-pane-width", 81);
429 	options_set_number(wo, "mode-attr", 0);
430 	options_set_number(wo, "mode-bg", 3);
431 	options_set_number(wo, "mode-fg", 0);
432 	options_set_number(wo, "mode-keys", MODEKEY_EMACS);
433 	options_set_number(wo, "mode-mouse", 0);
434 	options_set_number(wo, "monitor-activity", 0);
435 	options_set_string(wo, "monitor-content", "%s", "");
436 	options_set_number(wo, "window-status-attr", 0);
437 	options_set_number(wo, "window-status-bg", 8);
438 	options_set_number(wo, "window-status-current-attr", 0);
439 	options_set_number(wo, "window-status-current-bg", 8);
440 	options_set_number(wo, "window-status-current-fg", 8);
441 	options_set_number(wo, "window-status-fg", 8);
442 	options_set_number(wo, "xterm-keys", 0);
443  	options_set_number(wo, "remain-on-exit", 0);
444 	options_set_number(wo, "synchronize-panes", 0);
445 
446  	if (flags & IDENTIFY_UTF8) {
447 		options_set_number(so, "status-utf8", 1);
448 		options_set_number(wo, "utf8", 1);
449 	} else {
450 		options_set_number(so, "status-utf8", 0);
451 		options_set_number(wo, "utf8", 0);
452 	}
453 
454 	if (getcwd(cwd, sizeof cwd) == NULL) {
455 		pw = getpwuid(getuid());
456 		if (pw->pw_dir != NULL && *pw->pw_dir != '\0')
457 			strlcpy(cwd, pw->pw_dir, sizeof cwd);
458 		else
459 			strlcpy(cwd, "/", sizeof cwd);
460 	}
461 	options_set_string(so, "default-path", "%s", cwd);
462 
463 	if (cfg_file == NULL) {
464 		home = getenv("HOME");
465 		if (home == NULL || *home == '\0') {
466 			pw = getpwuid(getuid());
467 			if (pw != NULL)
468 				home = pw->pw_dir;
469 		}
470 		xasprintf(&cfg_file, "%s/%s", home, DEFAULT_CFG);
471 		if (access(cfg_file, R_OK) != 0) {
472 			xfree(cfg_file);
473 			cfg_file = NULL;
474 		}
475 	} else {
476 		if (access(cfg_file, R_OK) != 0) {
477 			log_warn("%s", cfg_file);
478 			exit(1);
479 		}
480 	}
481 
482 	if (label == NULL)
483 		label = xstrdup("default");
484 	if (path == NULL && (path = makesockpath(label)) == NULL) {
485 		log_warn("can't create socket");
486 		exit(1);
487 	}
488 	xfree(label);
489 
490 	if (shellcmd != NULL) {
491 		msg = MSG_SHELL;
492 		buf = NULL;
493 		len = 0;
494 	} else if (prepare_cmd(&msg, &buf, &len, argc, argv) != 0)
495 		exit(1);
496 
497 	if (shellcmd != NULL)
498 		cmdflags |= CMD_STARTSERVER;
499 	else if (argc == 0)	/* new-session is the default */
500 		cmdflags |= CMD_STARTSERVER|CMD_SENDENVIRON;
501 	else {
502 		/*
503 		 * It sucks parsing the command string twice (in client and
504 		 * later in server) but it is necessary to get the start server
505 		 * flag.
506 		 */
507 		if ((cmdlist = cmd_list_parse(argc, argv, &cause)) == NULL) {
508 			log_warnx("%s", cause);
509 			exit(1);
510 		}
511 		cmdflags &= ~CMD_STARTSERVER;
512 		TAILQ_FOREACH(cmd, cmdlist, qentry) {
513 			if (cmd->entry->flags & CMD_STARTSERVER)
514 				cmdflags |= CMD_STARTSERVER;
515 			if (cmd->entry->flags & CMD_SENDENVIRON)
516 				cmdflags |= CMD_SENDENVIRON;
517 		}
518 		cmd_list_free(cmdlist);
519 	}
520 
521  	memset(&cctx, 0, sizeof cctx);
522 	if (client_init(path, &cctx, cmdflags, flags) != 0)
523 		exit(1);
524 	xfree(path);
525 
526 	client_write_server(&cctx, msg, buf, len);
527 	memset(buf, 0, len);
528 
529 	retcode = 0;
530 	for (;;) {
531 		pfd.fd = cctx.ibuf.fd;
532 		pfd.events = POLLIN;
533 		if (cctx.ibuf.w.queued != 0)
534 			pfd.events |= POLLOUT;
535 
536 		if ((nfds = poll(&pfd, 1, INFTIM)) == -1) {
537 			if (errno == EAGAIN || errno == EINTR)
538 				continue;
539 			fatal("poll failed");
540 		}
541 		if (nfds == 0)
542 			continue;
543 
544 		if (pfd.revents & (POLLERR|POLLHUP|POLLNVAL))
545 			fatalx("socket error");
546 
547                 if (pfd.revents & POLLIN) {
548 			if (dispatch_imsg(&cctx, shellcmd, &retcode) != 0)
549 				break;
550 		}
551 
552 		if (pfd.revents & POLLOUT) {
553 			if (msgbuf_write(&cctx.ibuf.w) < 0)
554 				fatalx("msgbuf_write failed");
555 		}
556 	}
557 
558 	options_free(&global_s_options);
559 	options_free(&global_w_options);
560 
561 	return (retcode);
562 }
563 
564 int
565 dispatch_imsg(struct client_ctx *cctx, const char *shellcmd, int *retcode)
566 {
567 	struct imsg		imsg;
568 	ssize_t			n, datalen;
569 	struct msg_print_data	printdata;
570 	struct msg_shell_data	shelldata;
571 
572         if ((n = imsg_read(&cctx->ibuf)) == -1 || n == 0)
573 		fatalx("imsg_read failed");
574 
575 	for (;;) {
576 		if ((n = imsg_get(&cctx->ibuf, &imsg)) == -1)
577 			fatalx("imsg_get failed");
578 		if (n == 0)
579 			return (0);
580 		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
581 
582 		switch (imsg.hdr.type) {
583 		case MSG_EXIT:
584 		case MSG_SHUTDOWN:
585 			if (datalen != 0)
586 				fatalx("bad MSG_EXIT size");
587 
588 			return (-1);
589 		case MSG_ERROR:
590 			*retcode = 1;
591 			/* FALLTHROUGH */
592 		case MSG_PRINT:
593 			if (datalen != sizeof printdata)
594 				fatalx("bad MSG_PRINT size");
595 			memcpy(&printdata, imsg.data, sizeof printdata);
596 			printdata.msg[(sizeof printdata.msg) - 1] = '\0';
597 
598 			log_info("%s", printdata.msg);
599 			break;
600 		case MSG_READY:
601 			if (datalen != 0)
602 				fatalx("bad MSG_READY size");
603 
604 			*retcode = client_main(cctx);
605 			return (-1);
606 		case MSG_VERSION:
607 			if (datalen != 0)
608 				fatalx("bad MSG_VERSION size");
609 
610 			log_warnx("protocol version mismatch (client %u, "
611 			    "server %u)", PROTOCOL_VERSION, imsg.hdr.peerid);
612 			*retcode = 1;
613 			return (-1);
614 		case MSG_SHELL:
615 			if (datalen != sizeof shelldata)
616 				fatalx("bad MSG_SHELL size");
617 			memcpy(&shelldata, imsg.data, sizeof shelldata);
618 			shelldata.shell[(sizeof shelldata.shell) - 1] = '\0';
619 
620 			shell_exec(shelldata.shell, shellcmd);
621 		default:
622 			fatalx("unexpected message");
623 		}
624 
625 		imsg_free(&imsg);
626 	}
627 }
628 
629 __dead void
630 shell_exec(const char *shell, const char *shellcmd)
631 {
632 	const char	*shellname, *ptr;
633 	char		*argv0;
634 
635 	sigreset();
636 
637 	ptr = strrchr(shell, '/');
638 	if (ptr != NULL && *(ptr + 1) != '\0')
639 		shellname = ptr + 1;
640 	else
641 		shellname = shell;
642 	if (login_shell)
643 		xasprintf(&argv0, "-%s", shellname);
644 	else
645 		xasprintf(&argv0, "%s", shellname);
646 	setenv("SHELL", shell, 1);
647 
648 	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
649 	fatal("execl failed");
650 }
651