xref: /openbsd-src/usr.bin/tmux/tmux.c (revision 0b7734b3d77bb9b21afec6f4621cae6c805dbd45)
1 /* $OpenBSD: tmux.c,v 1.170 2016/05/27 17:05:42 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 __dead void	 usage(void);
48 static char	*make_label(const char *);
49 
50 __dead void
51 usage(void)
52 {
53 	fprintf(stderr,
54 	    "usage: %s [-2Cluv] [-c shell-command] [-f file] [-L socket-name]\n"
55 	    "            [-S socket-path] [command [flags]]\n",
56 	    getprogname());
57 	exit(1);
58 }
59 
60 const char *
61 getshell(void)
62 {
63 	struct passwd	*pw;
64 	const char	*shell;
65 
66 	shell = getenv("SHELL");
67 	if (checkshell(shell))
68 		return (shell);
69 
70 	pw = getpwuid(getuid());
71 	if (pw != NULL && checkshell(pw->pw_shell))
72 		return (pw->pw_shell);
73 
74 	return (_PATH_BSHELL);
75 }
76 
77 int
78 checkshell(const char *shell)
79 {
80 	if (shell == NULL || *shell == '\0' || *shell != '/')
81 		return (0);
82 	if (areshell(shell))
83 		return (0);
84 	if (access(shell, X_OK) != 0)
85 		return (0);
86 	return (1);
87 }
88 
89 int
90 areshell(const char *shell)
91 {
92 	const char	*progname, *ptr;
93 
94 	if ((ptr = strrchr(shell, '/')) != NULL)
95 		ptr++;
96 	else
97 		ptr = shell;
98 	progname = getprogname();
99 	if (*progname == '-')
100 		progname++;
101 	if (strcmp(ptr, progname) == 0)
102 		return (1);
103 	return (0);
104 }
105 
106 static char *
107 make_label(const char *label)
108 {
109 	char		*base, resolved[PATH_MAX], *path, *s;
110 	struct stat	 sb;
111 	u_int		 uid;
112 	int		 saved_errno;
113 
114 	if (label == NULL)
115 		label = "default";
116 
117 	uid = getuid();
118 
119 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
120 		xasprintf(&base, "%s/tmux-%u", s, uid);
121 	else
122 		xasprintf(&base, "%s/tmux-%u", _PATH_TMP, uid);
123 
124 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
125 		goto fail;
126 
127 	if (lstat(base, &sb) != 0)
128 		goto fail;
129 	if (!S_ISDIR(sb.st_mode)) {
130 		errno = ENOTDIR;
131 		goto fail;
132 	}
133 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
134 		errno = EACCES;
135 		goto fail;
136 	}
137 
138 	if (realpath(base, resolved) == NULL)
139 		strlcpy(resolved, base, sizeof resolved);
140 	xasprintf(&path, "%s/%s", resolved, label);
141 	return (path);
142 
143 fail:
144 	saved_errno = errno;
145 	free(base);
146 	errno = saved_errno;
147 	return (NULL);
148 }
149 
150 void
151 setblocking(int fd, int state)
152 {
153 	int mode;
154 
155 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
156 		if (!state)
157 			mode |= O_NONBLOCK;
158 		else
159 			mode &= ~O_NONBLOCK;
160 		fcntl(fd, F_SETFL, mode);
161 	}
162 }
163 
164 const char *
165 find_home(void)
166 {
167 	struct passwd		*pw;
168 	static const char	*home;
169 
170 	if (home != NULL)
171 		return (home);
172 
173 	home = getenv("HOME");
174 	if (home == NULL || *home == '\0') {
175 		pw = getpwuid(getuid());
176 		if (pw != NULL)
177 			home = pw->pw_dir;
178 		else
179 			home = NULL;
180 	}
181 
182 	return (home);
183 }
184 
185 int
186 main(int argc, char **argv)
187 {
188 	char		*path, *label, **var, tmp[PATH_MAX], *shellcmd = NULL;
189 	const char	*s;
190 	int		 opt, flags, keys;
191 
192 	if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL) {
193 		if (setlocale(LC_CTYPE, "") == NULL)
194 			errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
195 		s = nl_langinfo(CODESET);
196 		if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
197 			errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
198 	}
199 
200 	setlocale(LC_TIME, "");
201 	tzset();
202 
203 	if (**argv == '-')
204 		flags = CLIENT_LOGIN;
205 	else
206 		flags = 0;
207 
208 	label = path = NULL;
209 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) {
210 		switch (opt) {
211 		case '2':
212 			flags |= CLIENT_256COLOURS;
213 			break;
214 		case 'c':
215 			free(shellcmd);
216 			shellcmd = xstrdup(optarg);
217 			break;
218 		case 'C':
219 			if (flags & CLIENT_CONTROL)
220 				flags |= CLIENT_CONTROLCONTROL;
221 			else
222 				flags |= CLIENT_CONTROL;
223 			break;
224 		case 'f':
225 			set_cfg_file(optarg);
226 			break;
227 		case 'l':
228 			flags |= CLIENT_LOGIN;
229 			break;
230 		case 'L':
231 			free(label);
232 			label = xstrdup(optarg);
233 			break;
234 		case 'q':
235 			break;
236 		case 'S':
237 			free(path);
238 			path = xstrdup(optarg);
239 			break;
240 		case 'u':
241 			flags |= CLIENT_UTF8;
242 			break;
243 		case 'v':
244 			log_add_level();
245 			break;
246 		default:
247 			usage();
248 		}
249 	}
250 	argc -= optind;
251 	argv += optind;
252 
253 	if (shellcmd != NULL && argc != 0)
254 		usage();
255 
256 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
257 	    "recvfd proc exec tty ps", NULL) != 0)
258 		err(1, "pledge");
259 
260 	/*
261 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
262 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
263 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
264 	 * terminal, or if not they know that output from UTF-8-capable
265 	 * programs may be wrong.
266 	 */
267 	if (getenv("TMUX") != NULL)
268 		flags |= CLIENT_UTF8;
269 	else {
270 		s = getenv("LC_ALL");
271 		if (s == NULL || *s == '\0')
272 			s = getenv("LC_CTYPE");
273 		if (s == NULL || *s == '\0')
274 			s = getenv("LANG");
275 		if (s == NULL || *s == '\0')
276 			s = "";
277 		if (strcasestr(s, "UTF-8") != NULL ||
278 		    strcasestr(s, "UTF8") != NULL)
279 			flags |= CLIENT_UTF8;
280 	}
281 
282 	global_hooks = hooks_create(NULL);
283 
284 	global_environ = environ_create();
285 	for (var = environ; *var != NULL; var++)
286 		environ_put(global_environ, *var);
287 	if (getcwd(tmp, sizeof tmp) != NULL)
288 		environ_set(global_environ, "PWD", "%s", tmp);
289 
290 	global_options = options_create(NULL);
291 	options_table_populate_tree(OPTIONS_TABLE_SERVER, global_options);
292 
293 	global_s_options = options_create(NULL);
294 	options_table_populate_tree(OPTIONS_TABLE_SESSION, global_s_options);
295 	options_set_string(global_s_options, "default-shell", "%s", getshell());
296 
297 	global_w_options = options_create(NULL);
298 	options_table_populate_tree(OPTIONS_TABLE_WINDOW, global_w_options);
299 
300 	/* Override keys to vi if VISUAL or EDITOR are set. */
301 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
302 		if (strrchr(s, '/') != NULL)
303 			s = strrchr(s, '/') + 1;
304 		if (strstr(s, "vi") != NULL)
305 			keys = MODEKEY_VI;
306 		else
307 			keys = MODEKEY_EMACS;
308 		options_set_number(global_s_options, "status-keys", keys);
309 		options_set_number(global_w_options, "mode-keys", keys);
310 	}
311 
312 	/*
313 	 * If socket is specified on the command-line with -S or -L, it is
314 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
315 	 * used.
316 	 */
317 	if (path == NULL && label == NULL) {
318 		s = getenv("TMUX");
319 		if (s != NULL && *s != '\0' && *s != ',') {
320 			path = xstrdup(s);
321 			path[strcspn (path, ",")] = '\0';
322 		}
323 	}
324 	if (path == NULL && (path = make_label(label)) == NULL) {
325 		fprintf(stderr, "can't create socket: %s\n", strerror(errno));
326 		exit(1);
327 	}
328 	socket_path = path;
329 	free(label);
330 
331 	/* Pass control to the client. */
332 	exit(client_main(event_init(), argc, argv, flags, shellcmd));
333 }
334