xref: /openbsd/usr.bin/tmux/tmux.c (revision 6f40fd34)
1 /* $OpenBSD: tmux.c,v 1.183 2017/07/03 08:08:30 nicm Exp $ */
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 <err.h>
23 #include <errno.h>
24 #include <event.h>
25 #include <fcntl.h>
26 #include <langinfo.h>
27 #include <locale.h>
28 #include <paths.h>
29 #include <pwd.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <time.h>
33 #include <unistd.h>
34 #include <util.h>
35 
36 #include "tmux.h"
37 
38 struct options	*global_options;	/* server options */
39 struct options	*global_s_options;	/* session options */
40 struct options	*global_w_options;	/* window options */
41 struct environ	*global_environ;
42 struct hooks	*global_hooks;
43 
44 struct timeval	 start_time;
45 const char	*socket_path;
46 int		 ptm_fd = -1;
47 
48 static __dead void	 usage(void);
49 static char		*make_label(const char *);
50 
51 static const char	*getshell(void);
52 static int		 checkshell(const char *);
53 
54 static __dead void
55 usage(void)
56 {
57 	fprintf(stderr,
58 	    "usage: %s [-2Cluv] [-c shell-command] [-f file] [-L socket-name]\n"
59 	    "            [-S socket-path] [command [flags]]\n",
60 	    getprogname());
61 	exit(1);
62 }
63 
64 static const char *
65 getshell(void)
66 {
67 	struct passwd	*pw;
68 	const char	*shell;
69 
70 	shell = getenv("SHELL");
71 	if (checkshell(shell))
72 		return (shell);
73 
74 	pw = getpwuid(getuid());
75 	if (pw != NULL && checkshell(pw->pw_shell))
76 		return (pw->pw_shell);
77 
78 	return (_PATH_BSHELL);
79 }
80 
81 static int
82 checkshell(const char *shell)
83 {
84 	if (shell == NULL || *shell != '/')
85 		return (0);
86 	if (areshell(shell))
87 		return (0);
88 	if (access(shell, X_OK) != 0)
89 		return (0);
90 	return (1);
91 }
92 
93 int
94 areshell(const char *shell)
95 {
96 	const char	*progname, *ptr;
97 
98 	if ((ptr = strrchr(shell, '/')) != NULL)
99 		ptr++;
100 	else
101 		ptr = shell;
102 	progname = getprogname();
103 	if (*progname == '-')
104 		progname++;
105 	if (strcmp(ptr, progname) == 0)
106 		return (1);
107 	return (0);
108 }
109 
110 static char *
111 make_label(const char *label)
112 {
113 	char		*base, resolved[PATH_MAX], *path, *s;
114 	struct stat	 sb;
115 	uid_t		 uid;
116 	int		 saved_errno;
117 
118 	if (label == NULL)
119 		label = "default";
120 	uid = getuid();
121 
122 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
123 		xasprintf(&base, "%s/tmux-%ld", s, (long)uid);
124 	else
125 		xasprintf(&base, "%s/tmux-%ld", _PATH_TMP, (long)uid);
126 
127 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
128 		goto fail;
129 
130 	if (lstat(base, &sb) != 0)
131 		goto fail;
132 	if (!S_ISDIR(sb.st_mode)) {
133 		errno = ENOTDIR;
134 		goto fail;
135 	}
136 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
137 		errno = EACCES;
138 		goto fail;
139 	}
140 
141 	if (realpath(base, resolved) == NULL)
142 		strlcpy(resolved, base, sizeof resolved);
143 	xasprintf(&path, "%s/%s", resolved, label);
144 
145 	free(base);
146 	return (path);
147 
148 fail:
149 	saved_errno = errno;
150 	free(base);
151 	errno = saved_errno;
152 	return (NULL);
153 }
154 
155 void
156 setblocking(int fd, int state)
157 {
158 	int mode;
159 
160 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
161 		if (!state)
162 			mode |= O_NONBLOCK;
163 		else
164 			mode &= ~O_NONBLOCK;
165 		fcntl(fd, F_SETFL, mode);
166 	}
167 }
168 
169 const char *
170 find_home(void)
171 {
172 	struct passwd		*pw;
173 	static const char	*home;
174 
175 	if (home != NULL)
176 		return (home);
177 
178 	home = getenv("HOME");
179 	if (home == NULL || *home == '\0') {
180 		pw = getpwuid(getuid());
181 		if (pw != NULL)
182 			home = pw->pw_dir;
183 		else
184 			home = NULL;
185 	}
186 
187 	return (home);
188 }
189 
190 int
191 main(int argc, char **argv)
192 {
193 	char					*path, *label, tmp[PATH_MAX];
194 	char					*shellcmd = NULL, **var;
195 	const char				*s, *shell;
196 	int					 opt, flags, keys;
197 	const struct options_table_entry	*oe;
198 
199 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
200 	    setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
201 		if (setlocale(LC_CTYPE, "") == NULL)
202 			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
203 		s = nl_langinfo(CODESET);
204 		if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
205 			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
206 	}
207 
208 	setlocale(LC_TIME, "");
209 	tzset();
210 
211 	if (**argv == '-')
212 		flags = CLIENT_LOGIN;
213 	else
214 		flags = 0;
215 
216 	label = path = NULL;
217 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) {
218 		switch (opt) {
219 		case '2':
220 			flags |= CLIENT_256COLOURS;
221 			break;
222 		case 'c':
223 			free(shellcmd);
224 			shellcmd = xstrdup(optarg);
225 			break;
226 		case 'C':
227 			if (flags & CLIENT_CONTROL)
228 				flags |= CLIENT_CONTROLCONTROL;
229 			else
230 				flags |= CLIENT_CONTROL;
231 			break;
232 		case 'f':
233 			set_cfg_file(optarg);
234 			break;
235 		case 'l':
236 			flags |= CLIENT_LOGIN;
237 			break;
238 		case 'L':
239 			free(label);
240 			label = xstrdup(optarg);
241 			break;
242 		case 'q':
243 			break;
244 		case 'S':
245 			free(path);
246 			path = xstrdup(optarg);
247 			break;
248 		case 'u':
249 			flags |= CLIENT_UTF8;
250 			break;
251 		case 'v':
252 			log_add_level();
253 			break;
254 		default:
255 			usage();
256 		}
257 	}
258 	argc -= optind;
259 	argv += optind;
260 
261 	if (shellcmd != NULL && argc != 0)
262 		usage();
263 
264 	if ((ptm_fd = getptmfd()) == -1)
265 		err(1, "getptmfd");
266 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
267 	    "recvfd proc exec tty ps", NULL) != 0)
268 		err(1, "pledge");
269 
270 	/*
271 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
272 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
273 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
274 	 * terminal, or if not they know that output from UTF-8-capable
275 	 * programs may be wrong.
276 	 */
277 	if (getenv("TMUX") != NULL)
278 		flags |= CLIENT_UTF8;
279 	else {
280 		s = getenv("LC_ALL");
281 		if (s == NULL || *s == '\0')
282 			s = getenv("LC_CTYPE");
283 		if (s == NULL || *s == '\0')
284 			s = getenv("LANG");
285 		if (s == NULL || *s == '\0')
286 			s = "";
287 		if (strcasestr(s, "UTF-8") != NULL ||
288 		    strcasestr(s, "UTF8") != NULL)
289 			flags |= CLIENT_UTF8;
290 	}
291 
292 	global_hooks = hooks_create(NULL);
293 
294 	global_environ = environ_create();
295 	for (var = environ; *var != NULL; var++)
296 		environ_put(global_environ, *var);
297 	if (getcwd(tmp, sizeof tmp) != NULL)
298 		environ_set(global_environ, "PWD", "%s", tmp);
299 
300 	global_options = options_create(NULL);
301 	global_s_options = options_create(NULL);
302 	global_w_options = options_create(NULL);
303 	for (oe = options_table; oe->name != NULL; oe++) {
304 		if (oe->scope == OPTIONS_TABLE_SERVER)
305 			options_default(global_options, oe);
306 		if (oe->scope == OPTIONS_TABLE_SESSION)
307 			options_default(global_s_options, oe);
308 		if (oe->scope == OPTIONS_TABLE_WINDOW)
309 			options_default(global_w_options, oe);
310 	}
311 
312 	/*
313 	 * The default shell comes from SHELL or from the user's passwd entry
314 	 * if available.
315 	 */
316 	shell = getshell();
317 	options_set_string(global_s_options, "default-shell", 0, "%s", shell);
318 
319 	/* Override keys to vi if VISUAL or EDITOR are set. */
320 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
321 		if (strrchr(s, '/') != NULL)
322 			s = strrchr(s, '/') + 1;
323 		if (strstr(s, "vi") != NULL)
324 			keys = MODEKEY_VI;
325 		else
326 			keys = MODEKEY_EMACS;
327 		options_set_number(global_s_options, "status-keys", keys);
328 		options_set_number(global_w_options, "mode-keys", keys);
329 	}
330 
331 	/*
332 	 * If socket is specified on the command-line with -S or -L, it is
333 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
334 	 * used.
335 	 */
336 	if (path == NULL && label == NULL) {
337 		s = getenv("TMUX");
338 		if (s != NULL && *s != '\0' && *s != ',') {
339 			path = xstrdup(s);
340 			path[strcspn(path, ",")] = '\0';
341 		}
342 	}
343 	if (path == NULL && (path = make_label(label)) == NULL) {
344 		fprintf(stderr, "can't create socket: %s\n", strerror(errno));
345 		exit(1);
346 	}
347 	socket_path = path;
348 	free(label);
349 
350 	/* Pass control to the client. */
351 	exit(client_main(event_init(), argc, argv, flags, shellcmd));
352 }
353