xref: /openbsd-src/usr.bin/tmux/tmux.c (revision c4ce9d7a63a0826d937537e91ffee21defc0885e)
1 /* $OpenBSD: tmux.c,v 1.162 2015/11/24 23:46:15 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
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 <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 
35 #include "tmux.h"
36 
37 struct options	*global_options;	/* server options */
38 struct options	*global_s_options;	/* session options */
39 struct options	*global_w_options;	/* window options */
40 struct environ	*global_environ;
41 
42 struct timeval	 start_time;
43 const char	*socket_path;
44 
45 __dead void	 usage(void);
46 static char	*make_label(const char *);
47 
48 __dead void
49 usage(void)
50 {
51 	fprintf(stderr,
52 	    "usage: %s [-2Cluv] [-c shell-command] [-f file] [-L socket-name]\n"
53 	    "            [-S socket-path] [command [flags]]\n",
54 	    __progname);
55 	exit(1);
56 }
57 
58 const char *
59 getshell(void)
60 {
61 	struct passwd	*pw;
62 	const char	*shell;
63 
64 	shell = getenv("SHELL");
65 	if (checkshell(shell))
66 		return (shell);
67 
68 	pw = getpwuid(getuid());
69 	if (pw != NULL && checkshell(pw->pw_shell))
70 		return (pw->pw_shell);
71 
72 	return (_PATH_BSHELL);
73 }
74 
75 int
76 checkshell(const char *shell)
77 {
78 	if (shell == NULL || *shell == '\0' || *shell != '/')
79 		return (0);
80 	if (areshell(shell))
81 		return (0);
82 	if (access(shell, X_OK) != 0)
83 		return (0);
84 	return (1);
85 }
86 
87 int
88 areshell(const char *shell)
89 {
90 	const char	*progname, *ptr;
91 
92 	if ((ptr = strrchr(shell, '/')) != NULL)
93 		ptr++;
94 	else
95 		ptr = shell;
96 	progname = __progname;
97 	if (*progname == '-')
98 		progname++;
99 	if (strcmp(ptr, progname) == 0)
100 		return (1);
101 	return (0);
102 }
103 
104 static char *
105 make_label(const char *label)
106 {
107 	char		*base, resolved[PATH_MAX], *path, *s;
108 	struct stat	 sb;
109 	u_int		 uid;
110 	int		 saved_errno;
111 
112 	if (label == NULL)
113 		label = "default";
114 
115 	uid = getuid();
116 
117 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
118 		xasprintf(&base, "%s/tmux-%u", s, uid);
119 	else
120 		xasprintf(&base, "%s/tmux-%u", _PATH_TMP, uid);
121 
122 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
123 		goto fail;
124 
125 	if (lstat(base, &sb) != 0)
126 		goto fail;
127 	if (!S_ISDIR(sb.st_mode)) {
128 		errno = ENOTDIR;
129 		goto fail;
130 	}
131 	if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) {
132 		errno = EACCES;
133 		goto fail;
134 	}
135 
136 	if (realpath(base, resolved) == NULL)
137 		strlcpy(resolved, base, sizeof resolved);
138 	xasprintf(&path, "%s/%s", resolved, label);
139 	return (path);
140 
141 fail:
142 	saved_errno = errno;
143 	free(base);
144 	errno = saved_errno;
145 	return (NULL);
146 }
147 
148 void
149 setblocking(int fd, int state)
150 {
151 	int mode;
152 
153 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
154 		if (!state)
155 			mode |= O_NONBLOCK;
156 		else
157 			mode &= ~O_NONBLOCK;
158 		fcntl(fd, F_SETFL, mode);
159 	}
160 }
161 
162 const char *
163 find_home(void)
164 {
165 	struct passwd		*pw;
166 	static const char	*home;
167 
168 	if (home != NULL)
169 		return (home);
170 
171 	home = getenv("HOME");
172 	if (home == NULL || *home == '\0') {
173 		pw = getpwuid(getuid());
174 		if (pw != NULL)
175 			home = pw->pw_dir;
176 		else
177 			home = NULL;
178 	}
179 
180 	return (home);
181 }
182 
183 int
184 main(int argc, char **argv)
185 {
186 	char		*path, *label, **var, tmp[PATH_MAX], *shellcmd = NULL;
187 	const char	*s;
188 	int		 opt, flags, keys;
189 
190 	setlocale(LC_TIME, "");
191 	tzset();
192 
193 	if (**argv == '-')
194 		flags = CLIENT_LOGIN;
195 	else
196 		flags = 0;
197 
198 	label = path = NULL;
199 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) {
200 		switch (opt) {
201 		case '2':
202 			flags |= CLIENT_256COLOURS;
203 			break;
204 		case 'c':
205 			free(shellcmd);
206 			shellcmd = xstrdup(optarg);
207 			break;
208 		case 'C':
209 			if (flags & CLIENT_CONTROL)
210 				flags |= CLIENT_CONTROLCONTROL;
211 			else
212 				flags |= CLIENT_CONTROL;
213 			break;
214 		case 'f':
215 			set_cfg_file(optarg);
216 			break;
217 		case 'l':
218 			flags |= CLIENT_LOGIN;
219 			break;
220 		case 'L':
221 			free(label);
222 			label = xstrdup(optarg);
223 			break;
224 		case 'q':
225 			break;
226 		case 'S':
227 			free(path);
228 			path = xstrdup(optarg);
229 			break;
230 		case 'u':
231 			flags |= CLIENT_UTF8;
232 			break;
233 		case 'v':
234 			log_add_level();
235 			break;
236 		default:
237 			usage();
238 		}
239 	}
240 	argc -= optind;
241 	argv += optind;
242 
243 	if (shellcmd != NULL && argc != 0)
244 		usage();
245 
246 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
247 	    "recvfd proc exec tty ps", NULL) != 0)
248 		err(1, "pledge");
249 
250 	/*
251 	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
252 	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
253 	 * UTF-8, it is a safe assumption that either they are using a UTF-8
254 	 * terminal, or if not they know that output from UTF-8-capable
255 	 * programs may be wrong.
256 	 */
257 	if (getenv("TMUX") != NULL)
258 		flags |= CLIENT_UTF8;
259 	else {
260 		s = getenv("LC_ALL");
261 		if (s == NULL || *s == '\0')
262 			s = getenv("LC_CTYPE");
263 		if (s == NULL || *s == '\0')
264 			s = getenv("LANG");
265 		if (s == NULL || *s == '\0')
266 			s = "";
267 		if (strcasestr(s, "UTF-8") != NULL ||
268 		    strcasestr(s, "UTF8") != NULL)
269 			flags |= CLIENT_UTF8;
270 	}
271 
272 	global_environ = environ_create();
273 	for (var = environ; *var != NULL; var++)
274 		environ_put(global_environ, *var);
275 	if (getcwd(tmp, sizeof tmp) != NULL)
276 		environ_set(global_environ, "PWD", "%s", tmp);
277 
278 	global_options = options_create(NULL);
279 	options_table_populate_tree(OPTIONS_TABLE_SERVER, global_options);
280 
281 	global_s_options = options_create(NULL);
282 	options_table_populate_tree(OPTIONS_TABLE_SESSION, global_s_options);
283 	options_set_string(global_s_options, "default-shell", "%s", getshell());
284 
285 	global_w_options = options_create(NULL);
286 	options_table_populate_tree(OPTIONS_TABLE_WINDOW, global_w_options);
287 
288 	/* Override keys to vi if VISUAL or EDITOR are set. */
289 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
290 		if (strrchr(s, '/') != NULL)
291 			s = strrchr(s, '/') + 1;
292 		if (strstr(s, "vi") != NULL)
293 			keys = MODEKEY_VI;
294 		else
295 			keys = MODEKEY_EMACS;
296 		options_set_number(global_s_options, "status-keys", keys);
297 		options_set_number(global_w_options, "mode-keys", keys);
298 	}
299 
300 	/*
301 	 * If socket is specified on the command-line with -S or -L, it is
302 	 * used. Otherwise, $TMUX is checked and if that fails "default" is
303 	 * used.
304 	 */
305 	if (path == NULL && label == NULL) {
306 		s = getenv("TMUX");
307 		if (s != NULL && *s != '\0' && *s != ',') {
308 			path = xstrdup(s);
309 			path[strcspn (path, ",")] = '\0';
310 		}
311 	}
312 	if (path == NULL && (path = make_label(label)) == NULL) {
313 		fprintf(stderr, "can't create socket: %s\n", strerror(errno));
314 		exit(1);
315 	}
316 	socket_path = path;
317 	free(label);
318 
319 	/* Pass control to the client. */
320 	exit(client_main(event_init(), argc, argv, flags, shellcmd));
321 }
322