xref: /netbsd-src/external/bsd/tmux/dist/tmux.c (revision 890b6d91a44b7fcb2dfbcbc1e93463086e462d2d)
1 /* $OpenBSD$ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
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 #include <sys/utsname.h>
22 
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <langinfo.h>
26 #include <locale.h>
27 #include <pwd.h>
28 #include <signal.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <time.h>
32 #include <unistd.h>
33 
34 #include "tmux.h"
35 
36 struct options	*global_options;	/* server options */
37 struct options	*global_s_options;	/* session options */
38 struct options	*global_w_options;	/* window options */
39 struct environ	*global_environ;
40 
41 struct timeval	 start_time;
42 const char	*socket_path;
43 int		 ptm_fd = -1;
44 const char	*shell_command;
45 
46 static __dead void	 usage(void);
47 static char		*make_label(const char *, char **);
48 
49 static int		 areshell(const char *);
50 static const char	*getshell(void);
51 
52 static __dead void
53 usage(void)
54 {
55 	fprintf(stderr,
56 	    "usage: %s [-2CDlNuVv] [-c shell-command] [-f file] [-L socket-name]\n"
57 	    "            [-S socket-path] [-T features] [command [flags]]\n",
58 	    getprogname());
59 	exit(1);
60 }
61 
62 static const char *
63 getshell(void)
64 {
65 	struct passwd	*pw;
66 	const char	*shell;
67 
68 	shell = getenv("SHELL");
69 	if (checkshell(shell))
70 		return (shell);
71 
72 	pw = getpwuid(getuid());
73 	if (pw != NULL && checkshell(pw->pw_shell))
74 		return (pw->pw_shell);
75 
76 	return (_PATH_BSHELL);
77 }
78 
79 int
80 checkshell(const char *shell)
81 {
82 	if (shell == NULL || *shell != '/')
83 		return (0);
84 	if (areshell(shell))
85 		return (0);
86 	if (access(shell, X_OK) != 0)
87 		return (0);
88 	return (1);
89 }
90 
91 static int
92 areshell(const char *shell)
93 {
94 	const char	*progname, *ptr;
95 
96 	if ((ptr = strrchr(shell, '/')) != NULL)
97 		ptr++;
98 	else
99 		ptr = shell;
100 	progname = getprogname();
101 	if (*progname == '-')
102 		progname++;
103 	if (strcmp(ptr, progname) == 0)
104 		return (1);
105 	return (0);
106 }
107 
108 static char *
109 expand_path(const char *path, const char *home)
110 {
111 	char			*expanded, *name;
112 	const char		*end;
113 	struct environ_entry	*value;
114 
115 	if (strncmp(path, "~/", 2) == 0) {
116 		if (home == NULL)
117 			return (NULL);
118 		xasprintf(&expanded, "%s%s", home, path + 1);
119 		return (expanded);
120 	}
121 
122 	if (*path == '$') {
123 		end = strchr(path, '/');
124 		if (end == NULL)
125 			name = xstrdup(path + 1);
126 		else
127 			name = xstrndup(path + 1, end - path - 1);
128 		value = environ_find(global_environ, name);
129 		free(name);
130 		if (value == NULL)
131 			return (NULL);
132 		if (end == NULL)
133 			end = "";
134 		xasprintf(&expanded, "%s%s", value->value, end);
135 		return (expanded);
136 	}
137 
138 	return (xstrdup(path));
139 }
140 
141 static void
142 expand_paths(const char *s, char ***paths, u_int *n, int ignore_errors)
143 {
144 	const char	*home = find_home();
145 	char		*copy, *next, *tmp, resolved[PATH_MAX], *expanded;
146 	char		*path;
147 	u_int		 i;
148 
149 	*paths = NULL;
150 	*n = 0;
151 
152 	copy = tmp = xstrdup(s);
153 	while ((next = strsep(&tmp, ":")) != NULL) {
154 		expanded = expand_path(next, home);
155 		if (expanded == NULL) {
156 			log_debug("%s: invalid path: %s", __func__, next);
157 			continue;
158 		}
159 		if (realpath(expanded, resolved) == NULL) {
160 			log_debug("%s: realpath(\"%s\") failed: %s", __func__,
161 			    expanded, strerror(errno));
162 			if (ignore_errors) {
163 				free(expanded);
164 				continue;
165 			}
166 			path = expanded;
167 		} else {
168 			path = xstrdup(resolved);
169 			free(expanded);
170 		}
171 		for (i = 0; i < *n; i++) {
172 			if (strcmp(path, (*paths)[i]) == 0)
173 				break;
174 		}
175 		if (i != *n) {
176 			log_debug("%s: duplicate path: %s", __func__, path);
177 			free(path);
178 			continue;
179 		}
180 		*paths = xreallocarray(*paths, (*n) + 1, sizeof *paths);
181 		(*paths)[(*n)++] = path;
182 	}
183 	free(copy);
184 }
185 
186 static char *
187 make_label(const char *label, char **cause)
188 {
189 	char		**paths, *path, *base;
190 	u_int		  i, n;
191 	struct stat	  sb;
192 	uid_t		  uid;
193 
194 	*cause = NULL;
195 	if (label == NULL)
196 		label = "default";
197 	uid = getuid();
198 
199 	expand_paths(TMUX_SOCK, &paths, &n, 1);
200 	if (n == 0) {
201 		xasprintf(cause, "no suitable socket path");
202 		return (NULL);
203 	}
204 	path = paths[0]; /* can only have one socket! */
205 	for (i = 1; i < n; i++)
206 		free(paths[i]);
207 	free(paths);
208 
209 	xasprintf(&base, "%s/tmux-%ld", path, (long)uid);
210 	free(path);
211 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
212 		xasprintf(cause, "couldn't create directory %s (%s)", base,
213 		    strerror(errno));
214 		goto fail;
215 	}
216 	if (lstat(base, &sb) != 0) {
217 		xasprintf(cause, "couldn't read directory %s (%s)", base,
218 		    strerror(errno));
219 		goto fail;
220 	}
221 	if (!S_ISDIR(sb.st_mode)) {
222 		xasprintf(cause, "%s is not a directory", base);
223 		goto fail;
224 	}
225 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
226 		xasprintf(cause, "directory %s has unsafe permissions", base);
227 		goto fail;
228 	}
229 	xasprintf(&path, "%s/%s", base, label);
230 	free(base);
231 	return (path);
232 
233 fail:
234 	free(base);
235 	return (NULL);
236 }
237 
238 char *
239 shell_argv0(const char *shell, int is_login)
240 {
241 	const char	*slash, *name;
242 	char		*argv0;
243 
244 	slash = strrchr(shell, '/');
245 	if (slash != NULL && slash[1] != '\0')
246 		name = slash + 1;
247 	else
248 		name = shell;
249 	if (is_login)
250 		xasprintf(&argv0, "-%s", name);
251 	else
252 		xasprintf(&argv0, "%s", name);
253 	return (argv0);
254 }
255 
256 void
257 setblocking(int fd, int state)
258 {
259 	int mode;
260 
261 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
262 		if (!state)
263 			mode |= O_NONBLOCK;
264 		else
265 			mode &= ~O_NONBLOCK;
266 		fcntl(fd, F_SETFL, mode);
267 	}
268 }
269 
270 uint64_t
271 get_timer(void)
272 {
273 	struct timespec	ts;
274 
275 	/*
276 	 * We want a timestamp in milliseconds suitable for time measurement,
277 	 * so prefer the monotonic clock.
278 	 */
279 	if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
280 		clock_gettime(CLOCK_REALTIME, &ts);
281 	return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL));
282 }
283 
284 const char *
285 sig2name(int signo)
286 {
287      static char	s[11];
288 
289 #ifdef HAVE_SYS_SIGNAME
290      if (signo > 0 && signo < NSIG)
291 	     return (sys_signame[signo]);
292 #endif
293      xsnprintf(s, sizeof s, "%d", signo);
294      return (s);
295 }
296 
297 const char *
298 find_cwd(void)
299 {
300 	char		 resolved1[PATH_MAX], resolved2[PATH_MAX];
301 	static char	 cwd[PATH_MAX];
302 	const char	*pwd;
303 
304 	if (getcwd(cwd, sizeof cwd) == NULL)
305 		return (NULL);
306 	if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
307 		return (cwd);
308 
309 	/*
310 	 * We want to use PWD so that symbolic links are maintained,
311 	 * but only if it matches the actual working directory.
312 	 */
313 	if (realpath(pwd, resolved1) == NULL)
314 		return (cwd);
315 	if (realpath(cwd, resolved2) == NULL)
316 		return (cwd);
317 	if (strcmp(resolved1, resolved2) != 0)
318 		return (cwd);
319 	return (pwd);
320 }
321 
322 const char *
323 find_home(void)
324 {
325 	struct passwd		*pw;
326 	static const char	*home;
327 
328 	if (home != NULL)
329 		return (home);
330 
331 	home = getenv("HOME");
332 	if (home == NULL || *home == '\0') {
333 		pw = getpwuid(getuid());
334 		if (pw != NULL)
335 			home = pw->pw_dir;
336 		else
337 			home = NULL;
338 	}
339 
340 	return (home);
341 }
342 
343 const char *
344 getversion(void)
345 {
346 	return (TMUX_VERSION);
347 }
348 
349 int
350 main(int argc, char **argv)
351 {
352 	char					*path = NULL, *label = NULL;
353 	char					*cause, **var;
354 	const char				*s, *cwd;
355 	int					 opt, keys, feat = 0, fflag = 0;
356 	uint64_t				 flags = 0;
357 	const struct options_table_entry	*oe;
358 	u_int					 i;
359 
360 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
361 	    setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
362 		if (setlocale(LC_CTYPE, "") == NULL)
363 			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
364 		s = nl_langinfo(CODESET);
365 		if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
366 			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
367 	}
368 
369 	setlocale(LC_TIME, "");
370 	tzset();
371 
372 	if (**argv == '-')
373 		flags = CLIENT_LOGIN;
374 
375 	global_environ = environ_create();
376 	for (var = environ; *var != NULL; var++)
377 		environ_put(global_environ, *var, 0);
378 	if ((cwd = find_cwd()) != NULL)
379 		environ_set(global_environ, "PWD", 0, "%s", cwd);
380 	expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1);
381 
382 	while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) {
383 		switch (opt) {
384 		case '2':
385 			tty_add_features(&feat, "256", ":,");
386 			break;
387 		case 'c':
388 			shell_command = optarg;
389 			break;
390 		case 'D':
391 			flags |= CLIENT_NOFORK;
392 			break;
393 		case 'C':
394 			if (flags & CLIENT_CONTROL)
395 				flags |= CLIENT_CONTROLCONTROL;
396 			else
397 				flags |= CLIENT_CONTROL;
398 			break;
399 		case 'f':
400 			if (!fflag) {
401 				fflag = 1;
402 				for (i = 0; i < cfg_nfiles; i++)
403 					free(cfg_files[i]);
404 				cfg_nfiles = 0;
405 			}
406 			cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1,
407 			    sizeof *cfg_files);
408 			cfg_files[cfg_nfiles++] = xstrdup(optarg);
409 			cfg_quiet = 0;
410 			break;
411 		case 'V':
412 			printf("tmux %s\n", getversion());
413 			exit(0);
414 		case 'l':
415 			flags |= CLIENT_LOGIN;
416 			break;
417 		case 'L':
418 			free(label);
419 			label = xstrdup(optarg);
420 			break;
421 		case 'N':
422 			flags |= CLIENT_NOSTARTSERVER;
423 			break;
424 		case 'q':
425 			break;
426 		case 'S':
427 			free(path);
428 			path = xstrdup(optarg);
429 			break;
430 		case 'T':
431 			tty_add_features(&feat, optarg, ":,");
432 			break;
433 		case 'u':
434 			flags |= CLIENT_UTF8;
435 			break;
436 		case 'v':
437 			log_add_level();
438 			break;
439 		default:
440 			usage();
441 		}
442 	}
443 	argc -= optind;
444 	argv += optind;
445 
446 	if (shell_command != NULL && argc != 0)
447 		usage();
448 	if ((flags & CLIENT_NOFORK) && argc != 0)
449 		usage();
450 
451 	if ((ptm_fd = getptmfd()) == -1)
452 		err(1, "getptmfd");
453 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
454 	    "recvfd proc exec tty ps", NULL) != 0)
455 		err(1, "pledge");
456 
457 	/*
458 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
459 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
460 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
461 	 * terminal, or if not they know that output from UTF-8-capable
462 	 * programs may be wrong.
463 	 */
464 	if (getenv("TMUX") != NULL)
465 		flags |= CLIENT_UTF8;
466 	else {
467 		s = getenv("LC_ALL");
468 		if (s == NULL || *s == '\0')
469 			s = getenv("LC_CTYPE");
470 		if (s == NULL || *s == '\0')
471 			s = getenv("LANG");
472 		if (s == NULL || *s == '\0')
473 			s = "";
474 		if (strcasestr(s, "UTF-8") != NULL ||
475 		    strcasestr(s, "UTF8") != NULL)
476 			flags |= CLIENT_UTF8;
477 	}
478 
479 	global_options = options_create(NULL);
480 	global_s_options = options_create(NULL);
481 	global_w_options = options_create(NULL);
482 	for (oe = options_table; oe->name != NULL; oe++) {
483 		if (oe->scope & OPTIONS_TABLE_SERVER)
484 			options_default(global_options, oe);
485 		if (oe->scope & OPTIONS_TABLE_SESSION)
486 			options_default(global_s_options, oe);
487 		if (oe->scope & OPTIONS_TABLE_WINDOW)
488 			options_default(global_w_options, oe);
489 	}
490 
491 	/*
492 	 * The default shell comes from SHELL or from the user's passwd entry
493 	 * if available.
494 	 */
495 	options_set_string(global_s_options, "default-shell", 0, "%s",
496 	    getshell());
497 
498 	/* Override keys to vi if VISUAL or EDITOR are set. */
499 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
500 		options_set_string(global_options, "editor", 0, "%s", s);
501 		if (strrchr(s, '/') != NULL)
502 			s = strrchr(s, '/') + 1;
503 		if (strstr(s, "vi") != NULL)
504 			keys = MODEKEY_VI;
505 		else
506 			keys = MODEKEY_EMACS;
507 		options_set_number(global_s_options, "status-keys", keys);
508 		options_set_number(global_w_options, "mode-keys", keys);
509 	}
510 
511 	/*
512 	 * If socket is specified on the command-line with -S or -L, it is
513 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
514 	 * used.
515 	 */
516 	if (path == NULL && label == NULL) {
517 		s = getenv("TMUX");
518 		if (s != NULL && *s != '\0' && *s != ',') {
519 			path = xstrdup(s);
520 			path[strcspn(path, ",")] = '\0';
521 		}
522 	}
523 	if (path == NULL) {
524 		if ((path = make_label(label, &cause)) == NULL) {
525 			if (cause != NULL) {
526 				fprintf(stderr, "%s\n", cause);
527 				free(cause);
528 			}
529 			exit(1);
530 		}
531 		flags |= CLIENT_DEFAULTSOCKET;
532 	}
533 	socket_path = path;
534 	free(label);
535 
536 	/* Pass control to the client. */
537 	exit(client_main(osdep_event_init(), argc, argv, flags, feat));
538 }
539