xref: /netbsd-src/external/bsd/tmux/dist/tmux.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
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 <event.h>
25 #include <fcntl.h>
26 #include <langinfo.h>
27 #include <locale.h>
28 #include <pwd.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 const char	*getshell(void);
50 static int		 checkshell(const char *);
51 
52 static __dead void
53 usage(void)
54 {
55 	fprintf(stderr,
56 	    "usage: %s [-2CluvV] [-c shell-command] [-f file] [-L socket-name]\n"
57 	    "            [-S socket-path] [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 static 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 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 make_label(const char *label, char **cause)
110 {
111 	char		*base, resolved[PATH_MAX], *path, *s;
112 	struct stat	 sb;
113 	uid_t		 uid;
114 
115 	*cause = NULL;
116 
117 	if (label == NULL)
118 		label = "default";
119 	uid = getuid();
120 
121 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
122 		xasprintf(&base, "%s/tmux-%ld", s, (long)uid);
123 	else
124 		xasprintf(&base, "%s/tmux-%ld", _PATH_TMP, (long)uid);
125 	if (realpath(base, resolved) == NULL &&
126 	    strlcpy(resolved, base, sizeof resolved) >= sizeof resolved) {
127 		errno = ERANGE;
128 		free(base);
129 		goto fail;
130 	}
131 	free(base);
132 
133 	if (mkdir(resolved, S_IRWXU) != 0 && errno != EEXIST)
134 		goto fail;
135 	if (lstat(resolved, &sb) != 0)
136 		goto fail;
137 	if (!S_ISDIR(sb.st_mode)) {
138 		errno = ENOTDIR;
139 		goto fail;
140 	}
141 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
142 		errno = EACCES;
143 		goto fail;
144 	}
145 	xasprintf(&path, "%s/%s", resolved, label);
146 	return (path);
147 
148 fail:
149 	xasprintf(cause, "error creating %s (%s)", resolved, strerror(errno));
150 	return (NULL);
151 }
152 
153 void
154 setblocking(int fd, int state)
155 {
156 	int mode;
157 
158 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
159 		if (!state)
160 			mode |= O_NONBLOCK;
161 		else
162 			mode &= ~O_NONBLOCK;
163 		fcntl(fd, F_SETFL, mode);
164 	}
165 }
166 
167 const char *
168 find_cwd(void)
169 {
170 	char		 resolved1[PATH_MAX], resolved2[PATH_MAX];
171 	static char	 cwd[PATH_MAX];
172 	const char	*pwd;
173 
174 	if (getcwd(cwd, sizeof cwd) == NULL)
175 		return (NULL);
176 	if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
177 		return (cwd);
178 
179 	/*
180 	 * We want to use PWD so that symbolic links are maintained,
181 	 * but only if it matches the actual working directory.
182 	 */
183 	if (realpath(pwd, resolved1) == NULL)
184 		return (cwd);
185 	if (realpath(cwd, resolved2) == NULL)
186 		return (cwd);
187 	if (strcmp(resolved1, resolved2) != 0)
188 		return (cwd);
189 	return (pwd);
190 }
191 
192 const char *
193 find_home(void)
194 {
195 	struct passwd		*pw;
196 	static const char	*home;
197 
198 	if (home != NULL)
199 		return (home);
200 
201 	home = getenv("HOME");
202 	if (home == NULL || *home == '\0') {
203 		pw = getpwuid(getuid());
204 		if (pw != NULL)
205 			home = pw->pw_dir;
206 		else
207 			home = NULL;
208 	}
209 
210 	return (home);
211 }
212 
213 const char *
214 getversion(void)
215 {
216 	return TMUX_VERSION;
217 }
218 
219 int
220 main(int argc, char **argv)
221 {
222 	char					*path, *label, *cause, **var;
223 	const char				*s, *shell, *cwd;
224 	int					 opt, flags, keys;
225 	const struct options_table_entry	*oe;
226 
227 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
228 	    setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
229 		if (setlocale(LC_CTYPE, "") == NULL)
230 			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
231 		s = nl_langinfo(CODESET);
232 		if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
233 			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
234 	}
235 
236 	setlocale(LC_TIME, "");
237 	tzset();
238 
239 	if (**argv == '-')
240 		flags = CLIENT_LOGIN;
241 	else
242 		flags = 0;
243 
244 	label = path = NULL;
245 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUvV")) != -1) {
246 		switch (opt) {
247 		case '2':
248 			flags |= CLIENT_256COLOURS;
249 			break;
250 		case 'c':
251 			shell_command = optarg;
252 			break;
253 		case 'C':
254 			if (flags & CLIENT_CONTROL)
255 				flags |= CLIENT_CONTROLCONTROL;
256 			else
257 				flags |= CLIENT_CONTROL;
258 			break;
259 		case 'f':
260 			set_cfg_file(optarg);
261 			break;
262  		case 'V':
263 			printf("%s %s\n", getprogname(), getversion());
264  			exit(0);
265 		case 'l':
266 			flags |= CLIENT_LOGIN;
267 			break;
268 		case 'L':
269 			free(label);
270 			label = xstrdup(optarg);
271 			break;
272 		case 'q':
273 			break;
274 		case 'S':
275 			free(path);
276 			path = xstrdup(optarg);
277 			break;
278 		case 'u':
279 			flags |= CLIENT_UTF8;
280 			break;
281 		case 'v':
282 			log_add_level();
283 			break;
284 		default:
285 			usage();
286 		}
287 	}
288 	argc -= optind;
289 	argv += optind;
290 
291 	if (shell_command != NULL && argc != 0)
292 		usage();
293 
294 	if ((ptm_fd = getptmfd()) == -1)
295 		err(1, "getptmfd");
296 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
297 	    "recvfd proc exec tty ps", NULL) != 0)
298 		err(1, "pledge");
299 
300 	/*
301 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
302 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
303 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
304 	 * terminal, or if not they know that output from UTF-8-capable
305 	 * programs may be wrong.
306 	 */
307 	if (getenv("TMUX") != NULL)
308 		flags |= CLIENT_UTF8;
309 	else {
310 		s = getenv("LC_ALL");
311 		if (s == NULL || *s == '\0')
312 			s = getenv("LC_CTYPE");
313 		if (s == NULL || *s == '\0')
314 			s = getenv("LANG");
315 		if (s == NULL || *s == '\0')
316 			s = "";
317 		if (strcasestr(s, "UTF-8") != NULL ||
318 		    strcasestr(s, "UTF8") != NULL)
319 			flags |= CLIENT_UTF8;
320 	}
321 
322 	global_environ = environ_create();
323 	for (var = environ; *var != NULL; var++)
324 		environ_put(global_environ, *var);
325 	if ((cwd = find_cwd()) != NULL)
326 		environ_set(global_environ, "PWD", "%s", cwd);
327 
328 	global_options = options_create(NULL);
329 	global_s_options = options_create(NULL);
330 	global_w_options = options_create(NULL);
331 	for (oe = options_table; oe->name != NULL; oe++) {
332 		if (oe->scope & OPTIONS_TABLE_SERVER)
333 			options_default(global_options, oe);
334 		if (oe->scope & OPTIONS_TABLE_SESSION)
335 			options_default(global_s_options, oe);
336 		if (oe->scope & OPTIONS_TABLE_WINDOW)
337 			options_default(global_w_options, oe);
338 	}
339 
340 	/*
341 	 * The default shell comes from SHELL or from the user's passwd entry
342 	 * if available.
343 	 */
344 	shell = getshell();
345 	options_set_string(global_s_options, "default-shell", 0, "%s", shell);
346 
347 	/* Override keys to vi if VISUAL or EDITOR are set. */
348 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
349 		if (strrchr(s, '/') != NULL)
350 			s = strrchr(s, '/') + 1;
351 		if (strstr(s, "vi") != NULL)
352 			keys = MODEKEY_VI;
353 		else
354 			keys = MODEKEY_EMACS;
355 		options_set_number(global_s_options, "status-keys", keys);
356 		options_set_number(global_w_options, "mode-keys", keys);
357 	}
358 
359 	/*
360 	 * If socket is specified on the command-line with -S or -L, it is
361 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
362 	 * used.
363 	 */
364 	if (path == NULL && label == NULL) {
365 		s = getenv("TMUX");
366 		if (s != NULL && *s != '\0' && *s != ',') {
367 			path = xstrdup(s);
368 			path[strcspn(path, ",")] = '\0';
369 		}
370 	}
371 	if (path == NULL && (path = make_label(label, &cause)) == NULL) {
372 		if (cause != NULL) {
373 			fprintf(stderr, "%s\n", cause);
374 			free(cause);
375 		}
376 		exit(1);
377 	}
378 	socket_path = path;
379 	free(label);
380 
381 	/* Pass control to the client. */
382 	exit(client_main(osdep_event_init(), argc, argv, flags));
383 }
384