xref: /openbsd-src/usr.bin/tmux/tmux.c (revision e5157e49389faebcb42b7237d55fbf096d9c2523)
1 /* $OpenBSD: tmux.c,v 1.132 2014/10/20 23:27:14 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 <getopt.h>
26 #include <locale.h>
27 #include <paths.h>
28 #include <pwd.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32 
33 #include "tmux.h"
34 
35 #ifdef DEBUG
36 extern char	*malloc_options;
37 #endif
38 
39 struct options	 global_options;	/* server options */
40 struct options	 global_s_options;	/* session options */
41 struct options	 global_w_options;	/* window options */
42 struct environ	 global_environ;
43 
44 struct event_base *ev_base;
45 
46 char		*cfg_file;
47 char		*shell_cmd;
48 int		 debug_level;
49 time_t		 start_time;
50 char		 socket_path[PATH_MAX];
51 int		 login_shell;
52 char		*environ_path;
53 
54 __dead void	 usage(void);
55 char 		*makesocketpath(const char *);
56 
57 __dead void
58 usage(void)
59 {
60 	fprintf(stderr,
61 	    "usage: %s [-2lquv] [-c shell-command] [-f file] [-L socket-name]\n"
62 	    "            [-S socket-path] [command [flags]]\n",
63 	    __progname);
64 	exit(1);
65 }
66 
67 void
68 logfile(const char *name)
69 {
70 	char	*path;
71 
72 	if (debug_level > 0) {
73 		xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
74 		log_open(path);
75 		free(path);
76 	}
77 }
78 
79 const char *
80 getshell(void)
81 {
82 	struct passwd	*pw;
83 	const char	*shell;
84 
85 	shell = getenv("SHELL");
86 	if (checkshell(shell))
87 		return (shell);
88 
89 	pw = getpwuid(getuid());
90 	if (pw != NULL && checkshell(pw->pw_shell))
91 		return (pw->pw_shell);
92 
93 	return (_PATH_BSHELL);
94 }
95 
96 int
97 checkshell(const char *shell)
98 {
99 	if (shell == NULL || *shell == '\0' || *shell != '/')
100 		return (0);
101 	if (areshell(shell))
102 		return (0);
103 	if (access(shell, X_OK) != 0)
104 		return (0);
105 	return (1);
106 }
107 
108 int
109 areshell(const char *shell)
110 {
111 	const char	*progname, *ptr;
112 
113 	if ((ptr = strrchr(shell, '/')) != NULL)
114 		ptr++;
115 	else
116 		ptr = shell;
117 	progname = __progname;
118 	if (*progname == '-')
119 		progname++;
120 	if (strcmp(ptr, progname) == 0)
121 		return (1);
122 	return (0);
123 }
124 
125 char *
126 makesocketpath(const char *label)
127 {
128 	char		base[PATH_MAX], realbase[PATH_MAX], *path, *s;
129 	struct stat	sb;
130 	u_int		uid;
131 
132 	uid = getuid();
133 	if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0')
134 		xsnprintf(base, sizeof base, "%s/", s);
135 	else if ((s = getenv("TMPDIR")) != NULL && *s != '\0')
136 		xsnprintf(base, sizeof base, "%s/tmux-%u", s, uid);
137 	else
138 		xsnprintf(base, sizeof base, "%s/tmux-%u", _PATH_TMP, uid);
139 
140 	if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST)
141 		return (NULL);
142 
143 	if (lstat(base, &sb) != 0)
144 		return (NULL);
145 	if (!S_ISDIR(sb.st_mode)) {
146 		errno = ENOTDIR;
147 		return (NULL);
148 	}
149 	if (sb.st_uid != uid || (!S_ISDIR(sb.st_mode) &&
150 		sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
151 		errno = EACCES;
152 		return (NULL);
153 	}
154 
155 	if (realpath(base, realbase) == NULL)
156 		strlcpy(realbase, base, sizeof realbase);
157 
158 	xasprintf(&path, "%s/%s", realbase, label);
159 	return (path);
160 }
161 
162 void
163 setblocking(int fd, int state)
164 {
165 	int mode;
166 
167 	if ((mode = fcntl(fd, F_GETFL)) != -1) {
168 		if (!state)
169 			mode |= O_NONBLOCK;
170 		else
171 			mode &= ~O_NONBLOCK;
172 		fcntl(fd, F_SETFL, mode);
173 	}
174 }
175 
176 __dead void
177 shell_exec(const char *shell, const char *shellcmd)
178 {
179 	const char	*shellname, *ptr;
180 	char		*argv0;
181 
182 	ptr = strrchr(shell, '/');
183 	if (ptr != NULL && *(ptr + 1) != '\0')
184 		shellname = ptr + 1;
185 	else
186 		shellname = shell;
187 	if (login_shell)
188 		xasprintf(&argv0, "-%s", shellname);
189 	else
190 		xasprintf(&argv0, "%s", shellname);
191 	setenv("SHELL", shell, 1);
192 
193 	setblocking(STDIN_FILENO, 1);
194 	setblocking(STDOUT_FILENO, 1);
195 	setblocking(STDERR_FILENO, 1);
196 	closefrom(STDERR_FILENO + 1);
197 
198 	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
199 	fatal("execl failed");
200 }
201 
202 int
203 main(int argc, char **argv)
204 {
205 	struct passwd	*pw;
206 	char		*s, *path, *label, **var, tmp[PATH_MAX];
207 	char		 in[256];
208 	const char	*home;
209 	long long	 pid;
210 	int	 	 opt, flags, keys, session;
211 
212 #ifdef DEBUG
213 	malloc_options = (char *) "AFGJPX";
214 #endif
215 
216 	setlocale(LC_TIME, "");
217 
218 	flags = 0;
219 	label = path = NULL;
220 	login_shell = (**argv == '-');
221 	while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) {
222 		switch (opt) {
223 		case '2':
224 			flags |= CLIENT_256COLOURS;
225 			break;
226 		case 'c':
227 			free(shell_cmd);
228 			shell_cmd = xstrdup(optarg);
229 			break;
230 		case 'C':
231 			if (flags & CLIENT_CONTROL)
232 				flags |= CLIENT_CONTROLCONTROL;
233 			else
234 				flags |= CLIENT_CONTROL;
235 			break;
236 		case 'f':
237 			free(cfg_file);
238 			cfg_file = xstrdup(optarg);
239 			break;
240 		case 'l':
241 			login_shell = 1;
242 			break;
243 		case 'L':
244 			free(label);
245 			label = xstrdup(optarg);
246 			break;
247 		case 'q':
248 			break;
249 		case 'S':
250 			free(path);
251 			path = xstrdup(optarg);
252 			break;
253 		case 'u':
254 			flags |= CLIENT_UTF8;
255 			break;
256 		case 'v':
257 			debug_level++;
258 			break;
259 		default:
260 			usage();
261 		}
262 	}
263 	argc -= optind;
264 	argv += optind;
265 
266 	if (shell_cmd != NULL && argc != 0)
267 		usage();
268 
269 	if (!(flags & CLIENT_UTF8)) {
270 		/*
271 		 * If the user has set whichever of LC_ALL, LC_CTYPE or LANG
272 		 * exist (in that order) to contain UTF-8, it is a safe
273 		 * assumption that either they are using a UTF-8 terminal, or
274 		 * if not they know that output from UTF-8-capable programs may
275 		 * be wrong.
276 		 */
277 		if ((s = getenv("LC_ALL")) == NULL || *s == '\0') {
278 			if ((s = getenv("LC_CTYPE")) == NULL || *s == '\0')
279 				s = getenv("LANG");
280 		}
281 		if (s != NULL && (strcasestr(s, "UTF-8") != NULL ||
282 		    strcasestr(s, "UTF8") != NULL))
283 			flags |= CLIENT_UTF8;
284 	}
285 
286 	environ_init(&global_environ);
287 	for (var = environ; *var != NULL; var++)
288 		environ_put(&global_environ, *var);
289 	if (getcwd(tmp, sizeof tmp) != NULL)
290 		environ_set(&global_environ, "PWD", tmp);
291 
292 	options_init(&global_options, NULL);
293 	options_table_populate_tree(server_options_table, &global_options);
294 
295 	options_init(&global_s_options, NULL);
296 	options_table_populate_tree(session_options_table, &global_s_options);
297 	options_set_string(&global_s_options, "default-shell", "%s",
298 	    getshell());
299 
300 	options_init(&global_w_options, NULL);
301 	options_table_populate_tree(window_options_table, &global_w_options);
302 
303 	/* Enable UTF-8 if the first client is on UTF-8 terminal. */
304 	if (flags & CLIENT_UTF8) {
305 		options_set_number(&global_s_options, "status-utf8", 1);
306 		options_set_number(&global_s_options, "mouse-utf8", 1);
307 		options_set_number(&global_w_options, "utf8", 1);
308 	}
309 
310 	/* Override keys to vi if VISUAL or EDITOR are set. */
311 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
312 		if (strrchr(s, '/') != NULL)
313 			s = strrchr(s, '/') + 1;
314 		if (strstr(s, "vi") != NULL)
315 			keys = MODEKEY_VI;
316 		else
317 			keys = MODEKEY_EMACS;
318 		options_set_number(&global_s_options, "status-keys", keys);
319 		options_set_number(&global_w_options, "mode-keys", keys);
320 	}
321 
322 	/* Locate the configuration file. */
323 	if (cfg_file == NULL) {
324 		home = getenv("HOME");
325 		if (home == NULL || *home == '\0') {
326 			pw = getpwuid(getuid());
327 			if (pw != NULL)
328 				home = pw->pw_dir;
329 			else
330 				home = NULL;
331 		}
332 		if (home != NULL) {
333 			xasprintf(&cfg_file, "%s/.tmux.conf", home);
334 			if (access(cfg_file, R_OK) != 0 && errno == ENOENT) {
335 				free(cfg_file);
336 				cfg_file = NULL;
337 			}
338 		}
339 	}
340 
341 	/* Get path from environment. */
342 	s = getenv("TMUX");
343 	if (s != NULL && sscanf(s, "%255[^,],%lld,%d", in, &pid, &session) == 3)
344 		environ_path = xstrdup(in);
345 
346 	/*
347 	 * Figure out the socket path. If specified on the command-line with -S
348 	 * or -L, use it, otherwise try $TMUX or assume -L default.
349 	 */
350 	if (path == NULL) {
351 		/* If no -L, use the environment. */
352 		if (label == NULL) {
353 			if (environ_path != NULL)
354 				path = xstrdup(environ_path);
355 			else
356 				label = xstrdup("default");
357 		}
358 
359 		/* -L or default set. */
360 		if (label != NULL) {
361 			if ((path = makesocketpath(label)) == NULL) {
362 				fprintf(stderr, "can't create socket: %s\n",
363 					strerror(errno));
364 				exit(1);
365 			}
366 		}
367 	}
368 	free(label);
369 
370 	if (strlcpy(socket_path, path, sizeof socket_path) >= sizeof socket_path) {
371 		fprintf(stderr, "socket path too long: %s\n", path);
372 		exit(1);
373 	}
374 	free(path);
375 
376 	/* Set process title. */
377 	setproctitle("%s (%s)", __progname, socket_path);
378 
379 	/* Pass control to the client. */
380 	ev_base = event_init();
381 	exit(client_main(argc, argv, flags));
382 }
383