xref: /openbsd-src/usr.bin/tmux/tmux.c (revision 89c96e90242a81edf0d9a0550930a11563268b9d)
1 /* $OpenBSD: tmux.c,v 1.175 2017/01/15 20:48:41 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 <getopt.h>
27 #include <langinfo.h>
28 #include <locale.h>
29 #include <paths.h>
30 #include <pwd.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <time.h>
34 #include <unistd.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 
47 static __dead void	 usage(void);
48 static char		*make_label(const char *);
49 
50 static const char	*getshell(void);
51 static int		 checkshell(const char *);
52 
53 static __dead void
54 usage(void)
55 {
56 	fprintf(stderr,
57 	    "usage: %s [-2Cluv] [-c shell-command] [-f file] [-L socket-name]\n"
58 	    "            [-S socket-path] [command [flags]]\n",
59 	    getprogname());
60 	exit(1);
61 }
62 
63 static const char *
64 getshell(void)
65 {
66 	struct passwd	*pw;
67 	const char	*shell;
68 
69 	shell = getenv("SHELL");
70 	if (checkshell(shell))
71 		return (shell);
72 
73 	pw = getpwuid(getuid());
74 	if (pw != NULL && checkshell(pw->pw_shell))
75 		return (pw->pw_shell);
76 
77 	return (_PATH_BSHELL);
78 }
79 
80 static int
81 checkshell(const char *shell)
82 {
83 	if (shell == NULL || *shell == '\0' || *shell != '/')
84 		return (0);
85 	if (areshell(shell))
86 		return (0);
87 	if (access(shell, X_OK) != 0)
88 		return (0);
89 	return (1);
90 }
91 
92 int
93 areshell(const char *shell)
94 {
95 	const char	*progname, *ptr;
96 
97 	if ((ptr = strrchr(shell, '/')) != NULL)
98 		ptr++;
99 	else
100 		ptr = shell;
101 	progname = getprogname();
102 	if (*progname == '-')
103 		progname++;
104 	if (strcmp(ptr, progname) == 0)
105 		return (1);
106 	return (0);
107 }
108 
109 static char *
110 make_label(const char *label)
111 {
112 	char		*base, resolved[PATH_MAX], *path, *s;
113 	struct stat	 sb;
114 	u_int		 uid;
115 	int		 saved_errno;
116 
117 	if (label == NULL)
118 		label = "default";
119 
120 	uid = getuid();
121 
122 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
123 		xasprintf(&base, "%s/tmux-%u", s, uid);
124 	else
125 		xasprintf(&base, "%s/tmux-%u", _PATH_TMP, 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 	return (path);
145 
146 fail:
147 	saved_errno = errno;
148 	free(base);
149 	errno = saved_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_home(void)
169 {
170 	struct passwd		*pw;
171 	static const char	*home;
172 
173 	if (home != NULL)
174 		return (home);
175 
176 	home = getenv("HOME");
177 	if (home == NULL || *home == '\0') {
178 		pw = getpwuid(getuid());
179 		if (pw != NULL)
180 			home = pw->pw_dir;
181 		else
182 			home = NULL;
183 	}
184 
185 	return (home);
186 }
187 
188 int
189 main(int argc, char **argv)
190 {
191 	char					*path, *label, tmp[PATH_MAX];
192 	char					*shellcmd = NULL, **var;
193 	const char				*s, *shell;
194 	int					 opt, flags, keys;
195 	const struct options_table_entry	*oe;
196 
197 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL) {
198 		if (setlocale(LC_CTYPE, "") == NULL)
199 			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
200 		s = nl_langinfo(CODESET);
201 		if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
202 			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
203 	}
204 
205 	setlocale(LC_TIME, "");
206 	tzset();
207 
208 	if (**argv == '-')
209 		flags = CLIENT_LOGIN;
210 	else
211 		flags = 0;
212 
213 	label = path = NULL;
214 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) {
215 		switch (opt) {
216 		case '2':
217 			flags |= CLIENT_256COLOURS;
218 			break;
219 		case 'c':
220 			free(shellcmd);
221 			shellcmd = xstrdup(optarg);
222 			break;
223 		case 'C':
224 			if (flags & CLIENT_CONTROL)
225 				flags |= CLIENT_CONTROLCONTROL;
226 			else
227 				flags |= CLIENT_CONTROL;
228 			break;
229 		case 'f':
230 			set_cfg_file(optarg);
231 			break;
232 		case 'l':
233 			flags |= CLIENT_LOGIN;
234 			break;
235 		case 'L':
236 			free(label);
237 			label = xstrdup(optarg);
238 			break;
239 		case 'q':
240 			break;
241 		case 'S':
242 			free(path);
243 			path = xstrdup(optarg);
244 			break;
245 		case 'u':
246 			flags |= CLIENT_UTF8;
247 			break;
248 		case 'v':
249 			log_add_level();
250 			break;
251 		default:
252 			usage();
253 		}
254 	}
255 	argc -= optind;
256 	argv += optind;
257 
258 	if (shellcmd != NULL && argc != 0)
259 		usage();
260 
261 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
262 	    "recvfd proc exec tty ps", NULL) != 0)
263 		err(1, "pledge");
264 
265 	/*
266 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
267 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
268 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
269 	 * terminal, or if not they know that output from UTF-8-capable
270 	 * programs may be wrong.
271 	 */
272 	if (getenv("TMUX") != NULL)
273 		flags |= CLIENT_UTF8;
274 	else {
275 		s = getenv("LC_ALL");
276 		if (s == NULL || *s == '\0')
277 			s = getenv("LC_CTYPE");
278 		if (s == NULL || *s == '\0')
279 			s = getenv("LANG");
280 		if (s == NULL || *s == '\0')
281 			s = "";
282 		if (strcasestr(s, "UTF-8") != NULL ||
283 		    strcasestr(s, "UTF8") != NULL)
284 			flags |= CLIENT_UTF8;
285 	}
286 
287 	global_hooks = hooks_create(NULL);
288 
289 	global_environ = environ_create();
290 	for (var = environ; *var != NULL; var++)
291 		environ_put(global_environ, *var);
292 	if (getcwd(tmp, sizeof tmp) != NULL)
293 		environ_set(global_environ, "PWD", "%s", tmp);
294 
295 	global_options = options_create(NULL);
296 	global_s_options = options_create(NULL);
297 	global_w_options = options_create(NULL);
298 	for (oe = options_table; oe->name != NULL; oe++) {
299 		if (oe->scope == OPTIONS_TABLE_SERVER)
300 			options_default(global_options, oe);
301 		if (oe->scope == OPTIONS_TABLE_SESSION)
302 			options_default(global_s_options, oe);
303 		if (oe->scope == OPTIONS_TABLE_WINDOW)
304 			options_default(global_w_options, oe);
305 	}
306 
307 	/*
308 	 * The default shell comes from SHELL or from the user's passwd entry
309 	 * if available.
310 	 */
311 	shell = getshell();
312 	options_set_string(global_s_options, "default-shell", 0, "%s", shell);
313 
314 	/* Override keys to vi if VISUAL or EDITOR are set. */
315 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
316 		if (strrchr(s, '/') != NULL)
317 			s = strrchr(s, '/') + 1;
318 		if (strstr(s, "vi") != NULL)
319 			keys = MODEKEY_VI;
320 		else
321 			keys = MODEKEY_EMACS;
322 		options_set_number(global_s_options, "status-keys", keys);
323 		options_set_number(global_w_options, "mode-keys", keys);
324 	}
325 
326 	/*
327 	 * If socket is specified on the command-line with -S or -L, it is
328 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
329 	 * used.
330 	 */
331 	if (path == NULL && label == NULL) {
332 		s = getenv("TMUX");
333 		if (s != NULL && *s != '\0' && *s != ',') {
334 			path = xstrdup(s);
335 			path[strcspn(path, ",")] = '\0';
336 		}
337 	}
338 	if (path == NULL && (path = make_label(label)) == NULL) {
339 		fprintf(stderr, "can't create socket: %s\n", strerror(errno));
340 		exit(1);
341 	}
342 	socket_path = path;
343 	free(label);
344 
345 	/* Pass control to the client. */
346 	exit(client_main(event_init(), argc, argv, flags, shellcmd));
347 }
348