xref: /openbsd-src/usr.bin/tmux/tmux.c (revision da34f2ce7df895d3d5be44aceda6cf76e90a91f5)
1 /* $OpenBSD: tmux.c,v 1.178 2017/03/21 19:28:03 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 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-%u", s, 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 	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 (pty_open(&ptm_fd) != 0)
262 		errx(1, "open(\"/dev/ptm\"");
263 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
264 	    "recvfd proc exec tty ps", NULL) != 0)
265 		err(1, "pledge");
266 
267 	/*
268 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
269 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
270 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
271 	 * terminal, or if not they know that output from UTF-8-capable
272 	 * programs may be wrong.
273 	 */
274 	if (getenv("TMUX") != NULL)
275 		flags |= CLIENT_UTF8;
276 	else {
277 		s = getenv("LC_ALL");
278 		if (s == NULL || *s == '\0')
279 			s = getenv("LC_CTYPE");
280 		if (s == NULL || *s == '\0')
281 			s = getenv("LANG");
282 		if (s == NULL || *s == '\0')
283 			s = "";
284 		if (strcasestr(s, "UTF-8") != NULL ||
285 		    strcasestr(s, "UTF8") != NULL)
286 			flags |= CLIENT_UTF8;
287 	}
288 
289 	global_hooks = hooks_create(NULL);
290 
291 	global_environ = environ_create();
292 	for (var = environ; *var != NULL; var++)
293 		environ_put(global_environ, *var);
294 	if (getcwd(tmp, sizeof tmp) != NULL)
295 		environ_set(global_environ, "PWD", "%s", tmp);
296 
297 	global_options = options_create(NULL);
298 	global_s_options = options_create(NULL);
299 	global_w_options = options_create(NULL);
300 	for (oe = options_table; oe->name != NULL; oe++) {
301 		if (oe->scope == OPTIONS_TABLE_SERVER)
302 			options_default(global_options, oe);
303 		if (oe->scope == OPTIONS_TABLE_SESSION)
304 			options_default(global_s_options, oe);
305 		if (oe->scope == OPTIONS_TABLE_WINDOW)
306 			options_default(global_w_options, oe);
307 	}
308 
309 	/*
310 	 * The default shell comes from SHELL or from the user's passwd entry
311 	 * if available.
312 	 */
313 	shell = getshell();
314 	options_set_string(global_s_options, "default-shell", 0, "%s", shell);
315 
316 	/* Override keys to vi if VISUAL or EDITOR are set. */
317 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
318 		if (strrchr(s, '/') != NULL)
319 			s = strrchr(s, '/') + 1;
320 		if (strstr(s, "vi") != NULL)
321 			keys = MODEKEY_VI;
322 		else
323 			keys = MODEKEY_EMACS;
324 		options_set_number(global_s_options, "status-keys", keys);
325 		options_set_number(global_w_options, "mode-keys", keys);
326 	}
327 
328 	/*
329 	 * If socket is specified on the command-line with -S or -L, it is
330 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
331 	 * used.
332 	 */
333 	if (path == NULL && label == NULL) {
334 		s = getenv("TMUX");
335 		if (s != NULL && *s != '\0' && *s != ',') {
336 			path = xstrdup(s);
337 			path[strcspn(path, ",")] = '\0';
338 		}
339 	}
340 	if (path == NULL && (path = make_label(label)) == NULL) {
341 		fprintf(stderr, "can't create socket: %s\n", strerror(errno));
342 		exit(1);
343 	}
344 	socket_path = path;
345 	free(label);
346 
347 	/* Pass control to the client. */
348 	exit(client_main(event_init(), argc, argv, flags, shellcmd));
349 }
350