xref: /netbsd-src/external/bsd/tmux/dist/tmux.c (revision 154bfe8e089c1a0a4e9ed8414f08d3da90949162)
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 
22 #include <errno.h>
23 #include <event.h>
24 #include <fcntl.h>
25 #include <langinfo.h>
26 #include <locale.h>
27 #include <pwd.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <time.h>
31 #include <unistd.h>
32 
33 #include "tmux.h"
34 
35 struct options	*global_options;	/* server options */
36 struct options	*global_s_options;	/* session options */
37 struct options	*global_w_options;	/* window options */
38 struct environ	*global_environ;
39 
40 struct timeval	 start_time;
41 const char	*socket_path;
42 int		 ptm_fd = -1;
43 const char	*shell_command;
44 
45 static __dead void	 usage(void);
46 static char		*make_label(const char *, char **);
47 
48 static const char	*getshell(void);
49 static int		 checkshell(const char *);
50 
51 static __dead void
52 usage(void)
53 {
54 	fprintf(stderr,
55 	    "usage: %s [-2CluvV] [-c shell-command] [-f file] [-L socket-name]\n"
56 	    "            [-S socket-path] [command [flags]]\n",
57 	    getprogname());
58 	exit(1);
59 }
60 
61 static const char *
62 getshell(void)
63 {
64 	struct passwd	*pw;
65 	const char	*shell;
66 
67 	shell = getenv("SHELL");
68 	if (checkshell(shell))
69 		return (shell);
70 
71 	pw = getpwuid(getuid());
72 	if (pw != NULL && checkshell(pw->pw_shell))
73 		return (pw->pw_shell);
74 
75 	return (_PATH_BSHELL);
76 }
77 
78 static int
79 checkshell(const char *shell)
80 {
81 	if (shell == NULL || *shell != '/')
82 		return (0);
83 	if (areshell(shell))
84 		return (0);
85 	if (access(shell, X_OK) != 0)
86 		return (0);
87 	return (1);
88 }
89 
90 int
91 areshell(const char *shell)
92 {
93 	const char	*progname, *ptr;
94 
95 	if ((ptr = strrchr(shell, '/')) != NULL)
96 		ptr++;
97 	else
98 		ptr = shell;
99 	progname = getprogname();
100 	if (*progname == '-')
101 		progname++;
102 	if (strcmp(ptr, progname) == 0)
103 		return (1);
104 	return (0);
105 }
106 
107 static char *
108 make_label(const char *label, char **cause)
109 {
110 	char		*base, resolved[PATH_MAX], *path, *s;
111 	struct stat	 sb;
112 	uid_t		 uid;
113 
114 	*cause = NULL;
115 
116 	if (label == NULL)
117 		label = "default";
118 	uid = getuid();
119 
120 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
121 		xasprintf(&base, "%s/tmux-%ld", s, (long)uid);
122 	else
123 		xasprintf(&base, "%s/tmux-%ld", _PATH_TMP, (long)uid);
124 	if (realpath(base, resolved) == NULL &&
125 	    strlcpy(resolved, base, sizeof resolved) >= sizeof resolved) {
126 		errno = ERANGE;
127 		free(base);
128 		goto fail;
129 	}
130 
131 	if (mkdir(resolved, S_IRWXU) != 0 && errno != EEXIST)
132 		goto fail;
133 	if (lstat(resolved, &sb) != 0)
134 		goto fail;
135 	if (!S_ISDIR(sb.st_mode)) {
136 		errno = ENOTDIR;
137 		goto fail;
138 	}
139 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
140 		errno = EACCES;
141 		goto fail;
142 	}
143 	xasprintf(&path, "%s/%s", resolved, label);
144 	return (path);
145 
146 fail:
147 	xasprintf(cause, "error creating %s (%s)", resolved, strerror(errno));
148 	return (NULL);
149 }
150 
151 void
152 setblocking(int fd, int state)
153 {
154 	int mode;
155 
156 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
157 		if (!state)
158 			mode |= O_NONBLOCK;
159 		else
160 			mode &= ~O_NONBLOCK;
161 		fcntl(fd, F_SETFL, mode);
162 	}
163 }
164 
165 const char *
166 find_cwd(void)
167 {
168 	char		 resolved1[PATH_MAX], resolved2[PATH_MAX];
169 	static char	 cwd[PATH_MAX];
170 	const char	*pwd;
171 
172 	if (getcwd(cwd, sizeof cwd) == NULL)
173 		return (NULL);
174 	if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
175 		return (cwd);
176 
177 	/*
178 	 * We want to use PWD so that symbolic links are maintained,
179 	 * but only if it matches the actual working directory.
180 	 */
181 	if (realpath(pwd, resolved1) == NULL)
182 		return (cwd);
183 	if (realpath(cwd, resolved2) == NULL)
184 		return (cwd);
185 	if (strcmp(resolved1, resolved2) != 0)
186 		return (cwd);
187 	return (pwd);
188 }
189 
190 const char *
191 find_home(void)
192 {
193 	struct passwd		*pw;
194 	static const char	*home;
195 
196 	if (home != NULL)
197 		return (home);
198 
199 	home = getenv("HOME");
200 	if (home == NULL || *home == '\0') {
201 		pw = getpwuid(getuid());
202 		if (pw != NULL)
203 			home = pw->pw_dir;
204 		else
205 			home = NULL;
206 	}
207 
208 	return (home);
209 }
210 
211 int
212 main(int argc, char **argv)
213 {
214 	char					*path, *label, *cause, **var;
215 	const char				*s, *shell, *cwd;
216 	int					 opt, flags, keys;
217 	const struct options_table_entry	*oe;
218 
219 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
220 	    setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
221 		if (setlocale(LC_CTYPE, "") == NULL)
222 			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
223 		s = nl_langinfo(CODESET);
224 		if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
225 			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
226 	}
227 
228 	setlocale(LC_TIME, "");
229 	tzset();
230 
231 	if (**argv == '-')
232 		flags = CLIENT_LOGIN;
233 	else
234 		flags = 0;
235 
236 	label = path = NULL;
237 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUVv")) != -1) {
238 		switch (opt) {
239 		case '2':
240 			flags |= CLIENT_256COLOURS;
241 			break;
242 		case 'c':
243 			shell_command = optarg;
244 			break;
245 		case 'C':
246 			if (flags & CLIENT_CONTROL)
247 				flags |= CLIENT_CONTROLCONTROL;
248 			else
249 				flags |= CLIENT_CONTROL;
250 			break;
251 		case 'V':
252 			printf("%s %s\n", getprogname(), VERSION);
253 			exit(0);
254 		case 'f':
255 			set_cfg_file(optarg);
256 			break;
257 		case 'l':
258 			flags |= CLIENT_LOGIN;
259 			break;
260 		case 'L':
261 			free(label);
262 			label = xstrdup(optarg);
263 			break;
264 		case 'q':
265 			break;
266 		case 'S':
267 			free(path);
268 			path = xstrdup(optarg);
269 			break;
270 		case 'u':
271 			flags |= CLIENT_UTF8;
272 			break;
273 		case 'v':
274 			log_add_level();
275 			break;
276 		default:
277 			usage();
278 		}
279 	}
280 	argc -= optind;
281 	argv += optind;
282 
283 	if (shell_command != NULL && argc != 0)
284 		usage();
285 
286 	if ((ptm_fd = getptmfd()) == -1)
287 		err(1, "getptmfd");
288 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
289 	    "recvfd proc exec tty ps", NULL) != 0)
290 		err(1, "pledge");
291 
292 	/*
293 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
294 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
295 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
296 	 * terminal, or if not they know that output from UTF-8-capable
297 	 * programs may be wrong.
298 	 */
299 	if (getenv("TMUX") != NULL)
300 		flags |= CLIENT_UTF8;
301 	else {
302 		s = getenv("LC_ALL");
303 		if (s == NULL || *s == '\0')
304 			s = getenv("LC_CTYPE");
305 		if (s == NULL || *s == '\0')
306 			s = getenv("LANG");
307 		if (s == NULL || *s == '\0')
308 			s = "";
309 		if (strcasestr(s, "UTF-8") != NULL ||
310 		    strcasestr(s, "UTF8") != NULL)
311 			flags |= CLIENT_UTF8;
312 	}
313 
314 	global_environ = environ_create();
315 	for (var = environ; *var != NULL; var++)
316 		environ_put(global_environ, *var);
317 	if ((cwd = find_cwd()) != NULL)
318 		environ_set(global_environ, "PWD", "%s", cwd);
319 
320 	global_options = options_create(NULL);
321 	global_s_options = options_create(NULL);
322 	global_w_options = options_create(NULL);
323 	for (oe = options_table; oe->name != NULL; oe++) {
324 		if (oe->scope & OPTIONS_TABLE_SERVER)
325 			options_default(global_options, oe);
326 		if (oe->scope & OPTIONS_TABLE_SESSION)
327 			options_default(global_s_options, oe);
328 		if (oe->scope & OPTIONS_TABLE_WINDOW)
329 			options_default(global_w_options, oe);
330 	}
331 
332 	/*
333 	 * The default shell comes from SHELL or from the user's passwd entry
334 	 * if available.
335 	 */
336 	shell = getshell();
337 	options_set_string(global_s_options, "default-shell", 0, "%s", shell);
338 
339 	/* Override keys to vi if VISUAL or EDITOR are set. */
340 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
341 		if (strrchr(s, '/') != NULL)
342 			s = strrchr(s, '/') + 1;
343 		if (strstr(s, "vi") != NULL)
344 			keys = MODEKEY_VI;
345 		else
346 			keys = MODEKEY_EMACS;
347 		options_set_number(global_s_options, "status-keys", keys);
348 		options_set_number(global_w_options, "mode-keys", keys);
349 	}
350 
351 	/*
352 	 * If socket is specified on the command-line with -S or -L, it is
353 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
354 	 * used.
355 	 */
356 	if (path == NULL && label == NULL) {
357 		s = getenv("TMUX");
358 		if (s != NULL && *s != '\0' && *s != ',') {
359 			path = xstrdup(s);
360 			path[strcspn(path, ",")] = '\0';
361 		}
362 	}
363 	if (path == NULL && (path = make_label(label, &cause)) == NULL) {
364 		if (cause != NULL) {
365 			fprintf(stderr, "%s\n", cause);
366 			free(cause);
367 		}
368 		exit(1);
369 	}
370 	socket_path = path;
371 	free(label);
372 
373 	/* Pass control to the client. */
374 	exit(client_main(osdep_event_init(), argc, argv, flags));
375 }
376