1 /* $OpenBSD: tmux.c,v 1.214 2024/10/02 11:48:16 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 #include <sys/utsname.h>
22
23 #include <err.h>
24 #include <errno.h>
25 #include <event.h>
26 #include <fcntl.h>
27 #include <langinfo.h>
28 #include <locale.h>
29 #include <paths.h>
30 #include <pwd.h>
31 #include <signal.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <time.h>
35 #include <unistd.h>
36 #include <util.h>
37
38 #include "tmux.h"
39
40 struct options *global_options; /* server options */
41 struct options *global_s_options; /* session options */
42 struct options *global_w_options; /* window options */
43 struct environ *global_environ;
44
45 struct timeval start_time;
46 const char *socket_path;
47 int ptm_fd = -1;
48 const char *shell_command;
49
50 static __dead void usage(void);
51 static char *make_label(const char *, char **);
52
53 static int areshell(const char *);
54 static const char *getshell(void);
55
56 static __dead void
usage(void)57 usage(void)
58 {
59 fprintf(stderr,
60 "usage: %s [-2CDlNuVv] [-c shell-command] [-f file] [-L socket-name]\n"
61 " [-S socket-path] [-T features] [command [flags]]\n",
62 getprogname());
63 exit(1);
64 }
65
66 static const char *
getshell(void)67 getshell(void)
68 {
69 struct passwd *pw;
70 const char *shell;
71
72 shell = getenv("SHELL");
73 if (checkshell(shell))
74 return (shell);
75
76 pw = getpwuid(getuid());
77 if (pw != NULL && checkshell(pw->pw_shell))
78 return (pw->pw_shell);
79
80 return (_PATH_BSHELL);
81 }
82
83 int
checkshell(const char * shell)84 checkshell(const char *shell)
85 {
86 if (shell == NULL || *shell != '/')
87 return (0);
88 if (areshell(shell))
89 return (0);
90 if (access(shell, X_OK) != 0)
91 return (0);
92 return (1);
93 }
94
95 static int
areshell(const char * shell)96 areshell(const char *shell)
97 {
98 const char *progname, *ptr;
99
100 if ((ptr = strrchr(shell, '/')) != NULL)
101 ptr++;
102 else
103 ptr = shell;
104 progname = getprogname();
105 if (*progname == '-')
106 progname++;
107 if (strcmp(ptr, progname) == 0)
108 return (1);
109 return (0);
110 }
111
112 static char *
expand_path(const char * path,const char * home)113 expand_path(const char *path, const char *home)
114 {
115 char *expanded, *name;
116 const char *end;
117 struct environ_entry *value;
118
119 if (strncmp(path, "~/", 2) == 0) {
120 if (home == NULL)
121 return (NULL);
122 xasprintf(&expanded, "%s%s", home, path + 1);
123 return (expanded);
124 }
125
126 if (*path == '$') {
127 end = strchr(path, '/');
128 if (end == NULL)
129 name = xstrdup(path + 1);
130 else
131 name = xstrndup(path + 1, end - path - 1);
132 value = environ_find(global_environ, name);
133 free(name);
134 if (value == NULL)
135 return (NULL);
136 if (end == NULL)
137 end = "";
138 xasprintf(&expanded, "%s%s", value->value, end);
139 return (expanded);
140 }
141
142 return (xstrdup(path));
143 }
144
145 static void
expand_paths(const char * s,char *** paths,u_int * n,int ignore_errors)146 expand_paths(const char *s, char ***paths, u_int *n, int ignore_errors)
147 {
148 const char *home = find_home();
149 char *copy, *next, *tmp, resolved[PATH_MAX], *expanded;
150 char *path;
151 u_int i;
152
153 *paths = NULL;
154 *n = 0;
155
156 copy = tmp = xstrdup(s);
157 while ((next = strsep(&tmp, ":")) != NULL) {
158 expanded = expand_path(next, home);
159 if (expanded == NULL) {
160 log_debug("%s: invalid path: %s", __func__, next);
161 continue;
162 }
163 if (realpath(expanded, resolved) == NULL) {
164 log_debug("%s: realpath(\"%s\") failed: %s", __func__,
165 expanded, strerror(errno));
166 if (ignore_errors) {
167 free(expanded);
168 continue;
169 }
170 path = expanded;
171 } else {
172 path = xstrdup(resolved);
173 free(expanded);
174 }
175 for (i = 0; i < *n; i++) {
176 if (strcmp(path, (*paths)[i]) == 0)
177 break;
178 }
179 if (i != *n) {
180 log_debug("%s: duplicate path: %s", __func__, path);
181 free(path);
182 continue;
183 }
184 *paths = xreallocarray(*paths, (*n) + 1, sizeof *paths);
185 (*paths)[(*n)++] = path;
186 }
187 free(copy);
188 }
189
190 static char *
make_label(const char * label,char ** cause)191 make_label(const char *label, char **cause)
192 {
193 char **paths, *path, *base;
194 u_int i, n;
195 struct stat sb;
196 uid_t uid;
197
198 *cause = NULL;
199 if (label == NULL)
200 label = "default";
201 uid = getuid();
202
203 expand_paths(TMUX_SOCK, &paths, &n, 1);
204 if (n == 0) {
205 xasprintf(cause, "no suitable socket path");
206 return (NULL);
207 }
208 path = paths[0]; /* can only have one socket! */
209 for (i = 1; i < n; i++)
210 free(paths[i]);
211 free(paths);
212
213 xasprintf(&base, "%s/tmux-%ld", path, (long)uid);
214 free(path);
215 if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
216 xasprintf(cause, "couldn't create directory %s (%s)", base,
217 strerror(errno));
218 goto fail;
219 }
220 if (lstat(base, &sb) != 0) {
221 xasprintf(cause, "couldn't read directory %s (%s)", base,
222 strerror(errno));
223 goto fail;
224 }
225 if (!S_ISDIR(sb.st_mode)) {
226 xasprintf(cause, "%s is not a directory", base);
227 goto fail;
228 }
229 if (sb.st_uid != uid || (sb.st_mode & TMUX_SOCK_PERM) != 0) {
230 xasprintf(cause, "directory %s has unsafe permissions", base);
231 goto fail;
232 }
233 xasprintf(&path, "%s/%s", base, label);
234 free(base);
235 return (path);
236
237 fail:
238 free(base);
239 return (NULL);
240 }
241
242 char *
shell_argv0(const char * shell,int is_login)243 shell_argv0(const char *shell, int is_login)
244 {
245 const char *slash, *name;
246 char *argv0;
247
248 slash = strrchr(shell, '/');
249 if (slash != NULL && slash[1] != '\0')
250 name = slash + 1;
251 else
252 name = shell;
253 if (is_login)
254 xasprintf(&argv0, "-%s", name);
255 else
256 xasprintf(&argv0, "%s", name);
257 return (argv0);
258 }
259
260 void
setblocking(int fd,int state)261 setblocking(int fd, int state)
262 {
263 int mode;
264
265 if ((mode = fcntl(fd, F_GETFL)) != -1) {
266 if (!state)
267 mode |= O_NONBLOCK;
268 else
269 mode &= ~O_NONBLOCK;
270 fcntl(fd, F_SETFL, mode);
271 }
272 }
273
274 uint64_t
get_timer(void)275 get_timer(void)
276 {
277 struct timespec ts;
278
279 /*
280 * We want a timestamp in milliseconds suitable for time measurement,
281 * so prefer the monotonic clock.
282 */
283 if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
284 clock_gettime(CLOCK_REALTIME, &ts);
285 return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL));
286 }
287
288 const char *
sig2name(int signo)289 sig2name(int signo)
290 {
291 static char s[11];
292
293 if (signo > 0 && signo < NSIG)
294 return (sys_signame[signo]);
295 xsnprintf(s, sizeof s, "%d", signo);
296 return (s);
297 }
298
299 const char *
find_cwd(void)300 find_cwd(void)
301 {
302 char resolved1[PATH_MAX], resolved2[PATH_MAX];
303 static char cwd[PATH_MAX];
304 const char *pwd;
305
306 if (getcwd(cwd, sizeof cwd) == NULL)
307 return (NULL);
308 if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
309 return (cwd);
310
311 /*
312 * We want to use PWD so that symbolic links are maintained,
313 * but only if it matches the actual working directory.
314 */
315 if (realpath(pwd, resolved1) == NULL)
316 return (cwd);
317 if (realpath(cwd, resolved2) == NULL)
318 return (cwd);
319 if (strcmp(resolved1, resolved2) != 0)
320 return (cwd);
321 return (pwd);
322 }
323
324 const char *
find_home(void)325 find_home(void)
326 {
327 struct passwd *pw;
328 static const char *home;
329
330 if (home != NULL)
331 return (home);
332
333 home = getenv("HOME");
334 if (home == NULL || *home == '\0') {
335 pw = getpwuid(getuid());
336 if (pw != NULL)
337 home = pw->pw_dir;
338 else
339 home = NULL;
340 }
341
342 return (home);
343 }
344
345 const char *
getversion(void)346 getversion(void)
347 {
348 static char *version;
349 struct utsname u;
350
351 if (version == NULL) {
352 if (uname(&u) < 0)
353 fatalx("uname failed");
354 xasprintf(&version, "openbsd-%s", u.release);
355 }
356 return (version);
357 }
358
359 int
main(int argc,char ** argv)360 main(int argc, char **argv)
361 {
362 char *path = NULL, *label = NULL;
363 char *cause, **var;
364 const char *s, *cwd;
365 int opt, keys, feat = 0, fflag = 0;
366 uint64_t flags = 0;
367 const struct options_table_entry *oe;
368 u_int i;
369
370 if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
371 setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
372 if (setlocale(LC_CTYPE, "") == NULL)
373 errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
374 s = nl_langinfo(CODESET);
375 if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
376 errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
377 }
378
379 setlocale(LC_TIME, "");
380 tzset();
381
382 if (**argv == '-')
383 flags = CLIENT_LOGIN;
384
385 global_environ = environ_create();
386 for (var = environ; *var != NULL; var++)
387 environ_put(global_environ, *var, 0);
388 if ((cwd = find_cwd()) != NULL)
389 environ_set(global_environ, "PWD", 0, "%s", cwd);
390 expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1);
391
392 while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) {
393 switch (opt) {
394 case '2':
395 tty_add_features(&feat, "256", ":,");
396 break;
397 case 'c':
398 shell_command = optarg;
399 break;
400 case 'D':
401 flags |= CLIENT_NOFORK;
402 break;
403 case 'C':
404 if (flags & CLIENT_CONTROL)
405 flags |= CLIENT_CONTROLCONTROL;
406 else
407 flags |= CLIENT_CONTROL;
408 break;
409 case 'f':
410 if (!fflag) {
411 fflag = 1;
412 for (i = 0; i < cfg_nfiles; i++)
413 free(cfg_files[i]);
414 cfg_nfiles = 0;
415 }
416 cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1,
417 sizeof *cfg_files);
418 cfg_files[cfg_nfiles++] = xstrdup(optarg);
419 cfg_quiet = 0;
420 break;
421 case 'V':
422 printf("tmux %s\n", getversion());
423 exit(0);
424 case 'l':
425 flags |= CLIENT_LOGIN;
426 break;
427 case 'L':
428 free(label);
429 label = xstrdup(optarg);
430 break;
431 case 'N':
432 flags |= CLIENT_NOSTARTSERVER;
433 break;
434 case 'q':
435 break;
436 case 'S':
437 free(path);
438 path = xstrdup(optarg);
439 break;
440 case 'T':
441 tty_add_features(&feat, optarg, ":,");
442 break;
443 case 'u':
444 flags |= CLIENT_UTF8;
445 break;
446 case 'v':
447 log_add_level();
448 break;
449 default:
450 usage();
451 }
452 }
453 argc -= optind;
454 argv += optind;
455
456 if (shell_command != NULL && argc != 0)
457 usage();
458 if ((flags & CLIENT_NOFORK) && argc != 0)
459 usage();
460
461 if ((ptm_fd = getptmfd()) == -1)
462 err(1, "getptmfd");
463 if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
464 "recvfd proc exec tty ps", NULL) != 0)
465 err(1, "pledge");
466
467 /*
468 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
469 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
470 * UTF-8, it is a safe assumption that either they are using a UTF-8
471 * terminal, or if not they know that output from UTF-8-capable
472 * programs may be wrong.
473 */
474 if (getenv("TMUX") != NULL)
475 flags |= CLIENT_UTF8;
476 else {
477 s = getenv("LC_ALL");
478 if (s == NULL || *s == '\0')
479 s = getenv("LC_CTYPE");
480 if (s == NULL || *s == '\0')
481 s = getenv("LANG");
482 if (s == NULL || *s == '\0')
483 s = "";
484 if (strcasestr(s, "UTF-8") != NULL ||
485 strcasestr(s, "UTF8") != NULL)
486 flags |= CLIENT_UTF8;
487 }
488
489 global_options = options_create(NULL);
490 global_s_options = options_create(NULL);
491 global_w_options = options_create(NULL);
492 for (oe = options_table; oe->name != NULL; oe++) {
493 if (oe->scope & OPTIONS_TABLE_SERVER)
494 options_default(global_options, oe);
495 if (oe->scope & OPTIONS_TABLE_SESSION)
496 options_default(global_s_options, oe);
497 if (oe->scope & OPTIONS_TABLE_WINDOW)
498 options_default(global_w_options, oe);
499 }
500
501 /*
502 * The default shell comes from SHELL or from the user's passwd entry
503 * if available.
504 */
505 options_set_string(global_s_options, "default-shell", 0, "%s",
506 getshell());
507
508 /* Override keys to vi if VISUAL or EDITOR are set. */
509 if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
510 options_set_string(global_options, "editor", 0, "%s", s);
511 if (strrchr(s, '/') != NULL)
512 s = strrchr(s, '/') + 1;
513 if (strstr(s, "vi") != NULL)
514 keys = MODEKEY_VI;
515 else
516 keys = MODEKEY_EMACS;
517 options_set_number(global_s_options, "status-keys", keys);
518 options_set_number(global_w_options, "mode-keys", keys);
519 }
520
521 /*
522 * If socket is specified on the command-line with -S or -L, it is
523 * used. Otherwise, $TMUX is checked and if that fails "default" is
524 * used.
525 */
526 if (path == NULL && label == NULL) {
527 s = getenv("TMUX");
528 if (s != NULL && *s != '\0' && *s != ',') {
529 path = xstrdup(s);
530 path[strcspn(path, ",")] = '\0';
531 }
532 }
533 if (path == NULL) {
534 if ((path = make_label(label, &cause)) == NULL) {
535 if (cause != NULL) {
536 fprintf(stderr, "%s\n", cause);
537 free(cause);
538 }
539 exit(1);
540 }
541 flags |= CLIENT_DEFAULTSOCKET;
542 }
543 socket_path = path;
544 free(label);
545
546 /* Pass control to the client. */
547 exit(client_main(event_init(), argc, argv, flags, feat));
548 }
549