1 /* $OpenBSD: tmux.c,v 1.208 2021/07/06 08:26:00 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 if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) { 215 xasprintf(cause, "couldn't create directory %s (%s)", base, 216 strerror(errno)); 217 goto fail; 218 } 219 if (lstat(base, &sb) != 0) { 220 xasprintf(cause, "couldn't read directory %s (%s)", base, 221 strerror(errno)); 222 goto fail; 223 } 224 if (!S_ISDIR(sb.st_mode)) { 225 xasprintf(cause, "%s is not a directory", base); 226 goto fail; 227 } 228 if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) { 229 xasprintf(cause, "directory %s has unsafe permissions", base); 230 goto fail; 231 } 232 xasprintf(&path, "%s/%s", base, label); 233 free(base); 234 return (path); 235 236 fail: 237 free(base); 238 return (NULL); 239 } 240 241 void 242 setblocking(int fd, int state) 243 { 244 int mode; 245 246 if ((mode = fcntl(fd, F_GETFL)) != -1) { 247 if (!state) 248 mode |= O_NONBLOCK; 249 else 250 mode &= ~O_NONBLOCK; 251 fcntl(fd, F_SETFL, mode); 252 } 253 } 254 255 uint64_t 256 get_timer(void) 257 { 258 struct timespec ts; 259 260 /* 261 * We want a timestamp in milliseconds suitable for time measurement, 262 * so prefer the monotonic clock. 263 */ 264 if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) 265 clock_gettime(CLOCK_REALTIME, &ts); 266 return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL)); 267 } 268 269 const char * 270 sig2name(int signo) 271 { 272 static char s[11]; 273 274 if (signo > 0 && signo < NSIG) 275 return (sys_signame[signo]); 276 xsnprintf(s, sizeof s, "%d", signo); 277 return (s); 278 } 279 280 const char * 281 find_cwd(void) 282 { 283 char resolved1[PATH_MAX], resolved2[PATH_MAX]; 284 static char cwd[PATH_MAX]; 285 const char *pwd; 286 287 if (getcwd(cwd, sizeof cwd) == NULL) 288 return (NULL); 289 if ((pwd = getenv("PWD")) == NULL || *pwd == '\0') 290 return (cwd); 291 292 /* 293 * We want to use PWD so that symbolic links are maintained, 294 * but only if it matches the actual working directory. 295 */ 296 if (realpath(pwd, resolved1) == NULL) 297 return (cwd); 298 if (realpath(cwd, resolved2) == NULL) 299 return (cwd); 300 if (strcmp(resolved1, resolved2) != 0) 301 return (cwd); 302 return (pwd); 303 } 304 305 const char * 306 find_home(void) 307 { 308 struct passwd *pw; 309 static const char *home; 310 311 if (home != NULL) 312 return (home); 313 314 home = getenv("HOME"); 315 if (home == NULL || *home == '\0') { 316 pw = getpwuid(getuid()); 317 if (pw != NULL) 318 home = pw->pw_dir; 319 else 320 home = NULL; 321 } 322 323 return (home); 324 } 325 326 const char * 327 getversion(void) 328 { 329 static char *version; 330 struct utsname u; 331 332 if (version == NULL) { 333 if (uname(&u) < 0) 334 fatalx("uname failed"); 335 xasprintf(&version, "openbsd-%s", u.release); 336 } 337 return (version); 338 } 339 340 int 341 main(int argc, char **argv) 342 { 343 char *path = NULL, *label = NULL; 344 char *cause, **var; 345 const char *s, *cwd; 346 int opt, keys, feat = 0, fflag = 0; 347 uint64_t flags = 0; 348 const struct options_table_entry *oe; 349 u_int i; 350 351 if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL && 352 setlocale(LC_CTYPE, "C.UTF-8") == NULL) { 353 if (setlocale(LC_CTYPE, "") == NULL) 354 errx(1, "invalid LC_ALL, LC_CTYPE or LANG"); 355 s = nl_langinfo(CODESET); 356 if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0) 357 errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s); 358 } 359 360 setlocale(LC_TIME, ""); 361 tzset(); 362 363 if (**argv == '-') 364 flags = CLIENT_LOGIN; 365 366 global_environ = environ_create(); 367 for (var = environ; *var != NULL; var++) 368 environ_put(global_environ, *var, 0); 369 if ((cwd = find_cwd()) != NULL) 370 environ_set(global_environ, "PWD", 0, "%s", cwd); 371 expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1); 372 373 while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) { 374 switch (opt) { 375 case '2': 376 tty_add_features(&feat, "256", ":,"); 377 break; 378 case 'c': 379 shell_command = optarg; 380 break; 381 case 'D': 382 flags |= CLIENT_NOFORK; 383 break; 384 case 'C': 385 if (flags & CLIENT_CONTROL) 386 flags |= CLIENT_CONTROLCONTROL; 387 else 388 flags |= CLIENT_CONTROL; 389 break; 390 case 'f': 391 if (!fflag) { 392 fflag = 1; 393 for (i = 0; i < cfg_nfiles; i++) 394 free(cfg_files[i]); 395 cfg_nfiles = 0; 396 } 397 cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1, 398 sizeof *cfg_files); 399 cfg_files[cfg_nfiles++] = xstrdup(optarg); 400 cfg_quiet = 0; 401 break; 402 case 'V': 403 printf("%s %s\n", getprogname(), getversion()); 404 exit(0); 405 case 'l': 406 flags |= CLIENT_LOGIN; 407 break; 408 case 'L': 409 free(label); 410 label = xstrdup(optarg); 411 break; 412 case 'N': 413 flags |= CLIENT_NOSTARTSERVER; 414 break; 415 case 'q': 416 break; 417 case 'S': 418 free(path); 419 path = xstrdup(optarg); 420 break; 421 case 'T': 422 tty_add_features(&feat, optarg, ":,"); 423 break; 424 case 'u': 425 flags |= CLIENT_UTF8; 426 break; 427 case 'v': 428 log_add_level(); 429 break; 430 default: 431 usage(); 432 } 433 } 434 argc -= optind; 435 argv += optind; 436 437 if (shell_command != NULL && argc != 0) 438 usage(); 439 if ((flags & CLIENT_NOFORK) && argc != 0) 440 usage(); 441 442 if ((ptm_fd = getptmfd()) == -1) 443 err(1, "getptmfd"); 444 if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd " 445 "recvfd proc exec tty ps", NULL) != 0) 446 err(1, "pledge"); 447 448 /* 449 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8. 450 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain 451 * UTF-8, it is a safe assumption that either they are using a UTF-8 452 * terminal, or if not they know that output from UTF-8-capable 453 * programs may be wrong. 454 */ 455 if (getenv("TMUX") != NULL) 456 flags |= CLIENT_UTF8; 457 else { 458 s = getenv("LC_ALL"); 459 if (s == NULL || *s == '\0') 460 s = getenv("LC_CTYPE"); 461 if (s == NULL || *s == '\0') 462 s = getenv("LANG"); 463 if (s == NULL || *s == '\0') 464 s = ""; 465 if (strcasestr(s, "UTF-8") != NULL || 466 strcasestr(s, "UTF8") != NULL) 467 flags |= CLIENT_UTF8; 468 } 469 470 global_options = options_create(NULL); 471 global_s_options = options_create(NULL); 472 global_w_options = options_create(NULL); 473 for (oe = options_table; oe->name != NULL; oe++) { 474 if (oe->scope & OPTIONS_TABLE_SERVER) 475 options_default(global_options, oe); 476 if (oe->scope & OPTIONS_TABLE_SESSION) 477 options_default(global_s_options, oe); 478 if (oe->scope & OPTIONS_TABLE_WINDOW) 479 options_default(global_w_options, oe); 480 } 481 482 /* 483 * The default shell comes from SHELL or from the user's passwd entry 484 * if available. 485 */ 486 options_set_string(global_s_options, "default-shell", 0, "%s", 487 getshell()); 488 489 /* Override keys to vi if VISUAL or EDITOR are set. */ 490 if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) { 491 options_set_string(global_options, "editor", 0, "%s", s); 492 if (strrchr(s, '/') != NULL) 493 s = strrchr(s, '/') + 1; 494 if (strstr(s, "vi") != NULL) 495 keys = MODEKEY_VI; 496 else 497 keys = MODEKEY_EMACS; 498 options_set_number(global_s_options, "status-keys", keys); 499 options_set_number(global_w_options, "mode-keys", keys); 500 } 501 502 /* 503 * If socket is specified on the command-line with -S or -L, it is 504 * used. Otherwise, $TMUX is checked and if that fails "default" is 505 * used. 506 */ 507 if (path == NULL && label == NULL) { 508 s = getenv("TMUX"); 509 if (s != NULL && *s != '\0' && *s != ',') { 510 path = xstrdup(s); 511 path[strcspn(path, ",")] = '\0'; 512 } 513 } 514 if (path == NULL) { 515 if ((path = make_label(label, &cause)) == NULL) { 516 if (cause != NULL) { 517 fprintf(stderr, "%s\n", cause); 518 free(cause); 519 } 520 exit(1); 521 } 522 flags |= CLIENT_DEFAULTSOCKET; 523 } 524 socket_path = path; 525 free(label); 526 527 /* Pass control to the client. */ 528 exit(client_main(event_init(), argc, argv, flags, feat)); 529 } 530