1 /* $OpenBSD: tmux.c,v 1.200 2020/05/16 15:24:28 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 [-2CluvV] [-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 void 146 expand_paths(const char *s, char ***paths, u_int *n) 147 { 148 const char *home = find_home(); 149 char *copy, *next, *tmp, resolved[PATH_MAX], *expanded; 150 u_int i; 151 152 *paths = NULL; 153 *n = 0; 154 155 copy = tmp = xstrdup(s); 156 while ((next = strsep(&tmp, ":")) != NULL) { 157 expanded = expand_path(next, home); 158 if (expanded == NULL) { 159 log_debug("%s: invalid path: %s", __func__, next); 160 continue; 161 } 162 if (realpath(expanded, resolved) == NULL) { 163 log_debug("%s: realpath(\"%s\") failed: %s", __func__, 164 expanded, strerror(errno)); 165 free(expanded); 166 continue; 167 } 168 free(expanded); 169 for (i = 0; i < *n; i++) { 170 if (strcmp(resolved, (*paths)[i]) == 0) 171 break; 172 } 173 if (i != *n) { 174 log_debug("%s: duplicate path: %s", __func__, resolved); 175 continue; 176 } 177 *paths = xreallocarray(*paths, (*n) + 1, sizeof *paths); 178 (*paths)[(*n)++] = xstrdup(resolved); 179 } 180 free(copy); 181 } 182 183 static char * 184 make_label(const char *label, char **cause) 185 { 186 char **paths, *path, *base; 187 u_int i, n; 188 struct stat sb; 189 uid_t uid; 190 191 *cause = NULL; 192 if (label == NULL) 193 label = "default"; 194 uid = getuid(); 195 196 expand_paths(TMUX_SOCK, &paths, &n); 197 if (n == 0) { 198 xasprintf(cause, "no suitable socket path"); 199 return (NULL); 200 } 201 path = paths[0]; /* can only have one socket! */ 202 for (i = 1; i < n; i++) 203 free(paths[i]); 204 free(paths); 205 206 xasprintf(&base, "%s/tmux-%ld", path, (long)uid); 207 if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) 208 goto fail; 209 if (lstat(base, &sb) != 0) 210 goto fail; 211 if (!S_ISDIR(sb.st_mode)) { 212 errno = ENOTDIR; 213 goto fail; 214 } 215 if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) { 216 errno = EACCES; 217 goto fail; 218 } 219 xasprintf(&path, "%s/%s", base, label); 220 free(base); 221 return (path); 222 223 fail: 224 xasprintf(cause, "error creating %s (%s)", base, strerror(errno)); 225 free(base); 226 return (NULL); 227 } 228 229 void 230 setblocking(int fd, int state) 231 { 232 int mode; 233 234 if ((mode = fcntl(fd, F_GETFL)) != -1) { 235 if (!state) 236 mode |= O_NONBLOCK; 237 else 238 mode &= ~O_NONBLOCK; 239 fcntl(fd, F_SETFL, mode); 240 } 241 } 242 243 const char * 244 sig2name(int signo) 245 { 246 static char s[11]; 247 248 if (signo > 0 && signo < NSIG) 249 return (sys_signame[signo]); 250 xsnprintf(s, sizeof s, "%d", signo); 251 return (s); 252 } 253 254 const char * 255 find_cwd(void) 256 { 257 char resolved1[PATH_MAX], resolved2[PATH_MAX]; 258 static char cwd[PATH_MAX]; 259 const char *pwd; 260 261 if (getcwd(cwd, sizeof cwd) == NULL) 262 return (NULL); 263 if ((pwd = getenv("PWD")) == NULL || *pwd == '\0') 264 return (cwd); 265 266 /* 267 * We want to use PWD so that symbolic links are maintained, 268 * but only if it matches the actual working directory. 269 */ 270 if (realpath(pwd, resolved1) == NULL) 271 return (cwd); 272 if (realpath(cwd, resolved2) == NULL) 273 return (cwd); 274 if (strcmp(resolved1, resolved2) != 0) 275 return (cwd); 276 return (pwd); 277 } 278 279 const char * 280 find_home(void) 281 { 282 struct passwd *pw; 283 static const char *home; 284 285 if (home != NULL) 286 return (home); 287 288 home = getenv("HOME"); 289 if (home == NULL || *home == '\0') { 290 pw = getpwuid(getuid()); 291 if (pw != NULL) 292 home = pw->pw_dir; 293 else 294 home = NULL; 295 } 296 297 return (home); 298 } 299 300 const char * 301 getversion(void) 302 { 303 static char *version; 304 struct utsname u; 305 306 if (version == NULL) { 307 if (uname(&u) < 0) 308 fatalx("uname failed"); 309 xasprintf(&version, "openbsd-%s", u.release); 310 } 311 return (version); 312 } 313 314 int 315 main(int argc, char **argv) 316 { 317 char *path = NULL, *label = NULL; 318 char *cause, **var; 319 const char *s, *shell, *cwd; 320 int opt, flags = 0, keys; 321 int feat = 0; 322 const struct options_table_entry *oe; 323 324 if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL && 325 setlocale(LC_CTYPE, "C.UTF-8") == NULL) { 326 if (setlocale(LC_CTYPE, "") == NULL) 327 errx(1, "invalid LC_ALL, LC_CTYPE or LANG"); 328 s = nl_langinfo(CODESET); 329 if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0) 330 errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s); 331 } 332 333 setlocale(LC_TIME, ""); 334 tzset(); 335 336 if (**argv == '-') 337 flags = CLIENT_LOGIN; 338 339 while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:T:uUvV")) != -1) { 340 switch (opt) { 341 case '2': 342 tty_add_features(&feat, "256", ":,"); 343 break; 344 case 'c': 345 shell_command = optarg; 346 break; 347 case 'C': 348 if (flags & CLIENT_CONTROL) 349 flags |= CLIENT_CONTROLCONTROL; 350 else 351 flags |= CLIENT_CONTROL; 352 break; 353 case 'f': 354 set_cfg_file(optarg); 355 break; 356 case 'V': 357 printf("%s %s\n", getprogname(), getversion()); 358 exit(0); 359 case 'l': 360 flags |= CLIENT_LOGIN; 361 break; 362 case 'L': 363 free(label); 364 label = xstrdup(optarg); 365 break; 366 case 'q': 367 break; 368 case 'S': 369 free(path); 370 path = xstrdup(optarg); 371 break; 372 case 'T': 373 tty_add_features(&feat, optarg, ":,"); 374 break; 375 case 'u': 376 flags |= CLIENT_UTF8; 377 break; 378 case 'v': 379 log_add_level(); 380 break; 381 default: 382 usage(); 383 } 384 } 385 argc -= optind; 386 argv += optind; 387 388 if (shell_command != NULL && argc != 0) 389 usage(); 390 391 if ((ptm_fd = getptmfd()) == -1) 392 err(1, "getptmfd"); 393 if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd " 394 "recvfd proc exec tty ps", NULL) != 0) 395 err(1, "pledge"); 396 397 /* 398 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8. 399 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain 400 * UTF-8, it is a safe assumption that either they are using a UTF-8 401 * terminal, or if not they know that output from UTF-8-capable 402 * programs may be wrong. 403 */ 404 if (getenv("TMUX") != NULL) 405 flags |= CLIENT_UTF8; 406 else { 407 s = getenv("LC_ALL"); 408 if (s == NULL || *s == '\0') 409 s = getenv("LC_CTYPE"); 410 if (s == NULL || *s == '\0') 411 s = getenv("LANG"); 412 if (s == NULL || *s == '\0') 413 s = ""; 414 if (strcasestr(s, "UTF-8") != NULL || 415 strcasestr(s, "UTF8") != NULL) 416 flags |= CLIENT_UTF8; 417 } 418 419 global_environ = environ_create(); 420 for (var = environ; *var != NULL; var++) 421 environ_put(global_environ, *var, 0); 422 if ((cwd = find_cwd()) != NULL) 423 environ_set(global_environ, "PWD", 0, "%s", cwd); 424 425 global_options = options_create(NULL); 426 global_s_options = options_create(NULL); 427 global_w_options = options_create(NULL); 428 for (oe = options_table; oe->name != NULL; oe++) { 429 if (oe->scope & OPTIONS_TABLE_SERVER) 430 options_default(global_options, oe); 431 if (oe->scope & OPTIONS_TABLE_SESSION) 432 options_default(global_s_options, oe); 433 if (oe->scope & OPTIONS_TABLE_WINDOW) 434 options_default(global_w_options, oe); 435 } 436 437 /* 438 * The default shell comes from SHELL or from the user's passwd entry 439 * if available. 440 */ 441 shell = getshell(); 442 options_set_string(global_s_options, "default-shell", 0, "%s", shell); 443 444 /* Override keys to vi if VISUAL or EDITOR are set. */ 445 if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) { 446 options_set_string(global_options, "editor", 0, "%s", s); 447 if (strrchr(s, '/') != NULL) 448 s = strrchr(s, '/') + 1; 449 if (strstr(s, "vi") != NULL) 450 keys = MODEKEY_VI; 451 else 452 keys = MODEKEY_EMACS; 453 options_set_number(global_s_options, "status-keys", keys); 454 options_set_number(global_w_options, "mode-keys", keys); 455 } 456 457 /* 458 * If socket is specified on the command-line with -S or -L, it is 459 * used. Otherwise, $TMUX is checked and if that fails "default" is 460 * used. 461 */ 462 if (path == NULL && label == NULL) { 463 s = getenv("TMUX"); 464 if (s != NULL && *s != '\0' && *s != ',') { 465 path = xstrdup(s); 466 path[strcspn(path, ",")] = '\0'; 467 } 468 } 469 if (path == NULL) { 470 if ((path = make_label(label, &cause)) == NULL) { 471 if (cause != NULL) { 472 fprintf(stderr, "%s\n", cause); 473 free(cause); 474 } 475 exit(1); 476 } 477 flags |= CLIENT_DEFAULTSOCKET; 478 } 479 socket_path = path; 480 free(label); 481 482 /* Pass control to the client. */ 483 exit(client_main(event_init(), argc, argv, flags, feat)); 484 } 485