1 /* $OpenBSD: tmux.c,v 1.212 2024/05/15 09:59:12 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 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 * 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 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 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 * 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 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 * 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 & S_IRWXO) != 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 * 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 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 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 * 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 * 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 * 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 * 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 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