xref: /openbsd-src/usr.bin/tmux/tmux.c (revision 40b64c4112b26486ce77e4a02f4b24b5c562936e)
1 /* $OpenBSD: tmux.c,v 1.118 2013/03/27 11:24:18 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 <errno.h>
23 #include <event.h>
24 #include <fcntl.h>
25 #include <paths.h>
26 #include <pwd.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 
31 #include "tmux.h"
32 
33 #ifdef DEBUG
34 extern char	*malloc_options;
35 #endif
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 event_base *ev_base;
43 
44 char		*cfg_file;
45 char		*shell_cmd;
46 int		 debug_level;
47 time_t		 start_time;
48 char		 socket_path[MAXPATHLEN];
49 int		 login_shell;
50 char		*environ_path;
51 pid_t		 environ_pid = -1;
52 int		 environ_session_id = -1;
53 
54 __dead void	 usage(void);
55 void	 	 parseenvironment(void);
56 char 		*makesocketpath(const char *);
57 
58 __dead void
59 usage(void)
60 {
61 	fprintf(stderr,
62 	    "usage: %s [-28lquv] [-c shell-command] [-f file] [-L socket-name]\n"
63 	    "            [-S socket-path] [command [flags]]\n",
64 	    __progname);
65 	exit(1);
66 }
67 
68 void
69 logfile(const char *name)
70 {
71 	char	*path;
72 
73 	if (debug_level > 0) {
74 		xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
75 		log_open(debug_level, path);
76 		free(path);
77 	}
78 }
79 
80 const char *
81 getshell(void)
82 {
83 	struct passwd	*pw;
84 	const char	*shell;
85 
86 	shell = getenv("SHELL");
87 	if (checkshell(shell))
88 		return (shell);
89 
90 	pw = getpwuid(getuid());
91 	if (pw != NULL && checkshell(pw->pw_shell))
92 		return (pw->pw_shell);
93 
94 	return (_PATH_BSHELL);
95 }
96 
97 int
98 checkshell(const char *shell)
99 {
100 	if (shell == NULL || *shell == '\0' || *shell != '/')
101 		return (0);
102 	if (areshell(shell))
103 		return (0);
104 	if (access(shell, X_OK) != 0)
105 		return (0);
106 	return (1);
107 }
108 
109 int
110 areshell(const char *shell)
111 {
112 	const char	*progname, *ptr;
113 
114 	if ((ptr = strrchr(shell, '/')) != NULL)
115 		ptr++;
116 	else
117 		ptr = shell;
118 	progname = __progname;
119 	if (*progname == '-')
120 		progname++;
121 	if (strcmp(ptr, progname) == 0)
122 		return (1);
123 	return (0);
124 }
125 
126 const char*
127 get_full_path(const char *wd, const char *path)
128 {
129 	static char	newpath[MAXPATHLEN];
130 	char		oldpath[MAXPATHLEN];
131 
132 	if (getcwd(oldpath, sizeof oldpath) == NULL)
133 		return (NULL);
134 	if (chdir(wd) != 0)
135 		return (NULL);
136 	if (realpath(path, newpath) != 0)
137 		return (NULL);
138 	chdir(oldpath);
139 	return (newpath);
140 }
141 
142 void
143 parseenvironment(void)
144 {
145 	char	*env, path[256];
146 	long	 pid;
147 	int	 id;
148 
149 	if ((env = getenv("TMUX")) == NULL)
150 		return;
151 
152 	if (sscanf(env, "%255[^,],%ld,%d", path, &pid, &id) != 3)
153 		return;
154 	environ_path = xstrdup(path);
155 	environ_pid = pid;
156 	environ_session_id = id;
157 }
158 
159 char *
160 makesocketpath(const char *label)
161 {
162 	char		base[MAXPATHLEN], realbase[MAXPATHLEN], *path, *s;
163 	struct stat	sb;
164 	u_int		uid;
165 
166 	uid = getuid();
167 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
168 		xsnprintf(base, sizeof base, "%s/", s);
169 	else if ((s = getenv("TMPDIR")) != NULL && *s != '\0')
170 		xsnprintf(base, sizeof base, "%s/tmux-%u", s, uid);
171 	else
172 		xsnprintf(base, sizeof base, "%s/tmux-%u", _PATH_TMP, uid);
173 
174 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
175 		return (NULL);
176 
177 	if (lstat(base, &sb) != 0)
178 		return (NULL);
179 	if (!S_ISDIR(sb.st_mode)) {
180 		errno = ENOTDIR;
181 		return (NULL);
182 	}
183 	if (sb.st_uid != uid || (sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
184 		errno = EACCES;
185 		return (NULL);
186 	}
187 
188 	if (realpath(base, realbase) == NULL)
189 		strlcpy(realbase, base, sizeof realbase);
190 
191 	xasprintf(&path, "%s/%s", realbase, label);
192 	return (path);
193 }
194 
195 void
196 setblocking(int fd, int state)
197 {
198 	int mode;
199 
200 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
201 		if (!state)
202 			mode |= O_NONBLOCK;
203 		else
204 			mode &= ~O_NONBLOCK;
205 		fcntl(fd, F_SETFL, mode);
206 	}
207 }
208 
209 __dead void
210 shell_exec(const char *shell, const char *shellcmd)
211 {
212 	const char	*shellname, *ptr;
213 	char		*argv0;
214 
215 	ptr = strrchr(shell, '/');
216 	if (ptr != NULL && *(ptr + 1) != '\0')
217 		shellname = ptr + 1;
218 	else
219 		shellname = shell;
220 	if (login_shell)
221 		xasprintf(&argv0, "-%s", shellname);
222 	else
223 		xasprintf(&argv0, "%s", shellname);
224 	setenv("SHELL", shell, 1);
225 
226 	setblocking(STDIN_FILENO, 1);
227 	setblocking(STDOUT_FILENO, 1);
228 	setblocking(STDERR_FILENO, 1);
229 	closefrom(STDERR_FILENO + 1);
230 
231 	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
232 	fatal("execl failed");
233 }
234 
235 int
236 main(int argc, char **argv)
237 {
238 	struct passwd	*pw;
239 	char		*s, *path, *label, *home, **var;
240 	int	 	 opt, flags, quiet, keys;
241 
242 #ifdef DEBUG
243 	malloc_options = (char *) "AFGJPX";
244 #endif
245 
246 	quiet = flags = 0;
247 	label = path = NULL;
248 	login_shell = (**argv == '-');
249 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) {
250 		switch (opt) {
251 		case '2':
252 			flags |= IDENTIFY_256COLOURS;
253 			break;
254 		case 'c':
255 			free(shell_cmd);
256 			shell_cmd = xstrdup(optarg);
257 			break;
258 		case 'C':
259 			if (flags & IDENTIFY_CONTROL)
260 				flags |= IDENTIFY_TERMIOS;
261 			else
262 				flags |= IDENTIFY_CONTROL;
263 			break;
264 		case 'f':
265 			free(cfg_file);
266 			cfg_file = xstrdup(optarg);
267 			break;
268 		case 'l':
269 			login_shell = 1;
270 			break;
271 		case 'L':
272 			free(label);
273 			label = xstrdup(optarg);
274 			break;
275 		case 'q':
276 			quiet = 1;
277 			break;
278 		case 'S':
279 			free(path);
280 			path = xstrdup(optarg);
281 			break;
282 		case 'u':
283 			flags |= IDENTIFY_UTF8;
284 			break;
285 		case 'v':
286 			debug_level++;
287 			break;
288 		default:
289 			usage();
290 		}
291 	}
292 	argc -= optind;
293 	argv += optind;
294 
295 	if (shell_cmd != NULL && argc != 0)
296 		usage();
297 
298 	if (!(flags & IDENTIFY_UTF8)) {
299 		/*
300 		 * If the user has set whichever of LC_ALL, LC_CTYPE or LANG
301 		 * exist (in that order) to contain UTF-8, it is a safe
302 		 * assumption that either they are using a UTF-8 terminal, or
303 		 * if not they know that output from UTF-8-capable programs may
304 		 * be wrong.
305 		 */
306 		if ((s = getenv("LC_ALL")) == NULL || *s == '\0') {
307 			if ((s = getenv("LC_CTYPE")) == NULL || *s == '\0')
308 				s = getenv("LANG");
309 		}
310 		if (s != NULL && (strcasestr(s, "UTF-8") != NULL ||
311 		    strcasestr(s, "UTF8") != NULL))
312 			flags |= IDENTIFY_UTF8;
313 	}
314 
315 	environ_init(&global_environ);
316 	for (var = environ; *var != NULL; var++)
317 		environ_put(&global_environ, *var);
318 
319 	options_init(&global_options, NULL);
320 	options_table_populate_tree(server_options_table, &global_options);
321 	options_set_number(&global_options, "quiet", quiet);
322 
323 	options_init(&global_s_options, NULL);
324 	options_table_populate_tree(session_options_table, &global_s_options);
325 	options_set_string(&global_s_options, "default-shell", "%s", getshell());
326 
327 	options_init(&global_w_options, NULL);
328 	options_table_populate_tree(window_options_table, &global_w_options);
329 
330 	/* Enable UTF-8 if the first client is on UTF-8 terminal. */
331 	if (flags & IDENTIFY_UTF8) {
332 		options_set_number(&global_s_options, "status-utf8", 1);
333 		options_set_number(&global_s_options, "mouse-utf8", 1);
334 		options_set_number(&global_w_options, "utf8", 1);
335 	}
336 
337 	/* Override keys to vi if VISUAL or EDITOR are set. */
338 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
339 		if (strrchr(s, '/') != NULL)
340 			s = strrchr(s, '/') + 1;
341 		if (strstr(s, "vi") != NULL)
342 			keys = MODEKEY_VI;
343 		else
344 			keys = MODEKEY_EMACS;
345 		options_set_number(&global_s_options, "status-keys", keys);
346 		options_set_number(&global_w_options, "mode-keys", keys);
347 	}
348 
349 	/* Locate the configuration file. */
350 	if (cfg_file == NULL) {
351 		home = getenv("HOME");
352 		if (home == NULL || *home == '\0') {
353 			pw = getpwuid(getuid());
354 			if (pw != NULL)
355 				home = pw->pw_dir;
356 		}
357 		xasprintf(&cfg_file, "%s/%s", home, DEFAULT_CFG);
358 		if (access(cfg_file, R_OK) != 0 && errno == ENOENT) {
359 			free(cfg_file);
360 			cfg_file = NULL;
361 		}
362 	}
363 
364 	/*
365 	 * Figure out the socket path. If specified on the command-line with -S
366 	 * or -L, use it, otherwise try $TMUX or assume -L default.
367 	 */
368 	parseenvironment();
369 	if (path == NULL) {
370 		/* If no -L, use the environment. */
371 		if (label == NULL) {
372 			if (environ_path != NULL)
373 				path = xstrdup(environ_path);
374 			else
375 				label = xstrdup("default");
376 		}
377 
378 		/* -L or default set. */
379 		if (label != NULL) {
380 			if ((path = makesocketpath(label)) == NULL) {
381 				fprintf(stderr, "can't create socket\n");
382 				exit(1);
383 			}
384 		}
385 	}
386 	free(label);
387 	strlcpy(socket_path, path, sizeof socket_path);
388 	free(path);
389 
390 	/* Set process title. */
391 	setproctitle("%s (%s)", __progname, socket_path);
392 
393 	/* Pass control to the client. */
394 	ev_base = event_init();
395 	exit(client_main(argc, argv, flags));
396 }
397