1 /* $OpenBSD: tmux.c,v 1.197 2020/04/16 07:28:36 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] [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 make_label(const char *label, char **cause) 114 { 115 char *base, resolved[PATH_MAX], *path, *s; 116 struct stat sb; 117 uid_t uid; 118 119 *cause = NULL; 120 121 if (label == NULL) 122 label = "default"; 123 uid = getuid(); 124 125 if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0') 126 xasprintf(&base, "%s/tmux-%ld", s, (long)uid); 127 else 128 xasprintf(&base, "%s/tmux-%ld", _PATH_TMP, (long)uid); 129 if (realpath(base, resolved) == NULL && 130 strlcpy(resolved, base, sizeof resolved) >= sizeof resolved) { 131 errno = ERANGE; 132 free(base); 133 goto fail; 134 } 135 free(base); 136 137 if (mkdir(resolved, S_IRWXU) != 0 && errno != EEXIST) 138 goto fail; 139 if (lstat(resolved, &sb) != 0) 140 goto fail; 141 if (!S_ISDIR(sb.st_mode)) { 142 errno = ENOTDIR; 143 goto fail; 144 } 145 if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) { 146 errno = EACCES; 147 goto fail; 148 } 149 xasprintf(&path, "%s/%s", resolved, label); 150 return (path); 151 152 fail: 153 xasprintf(cause, "error creating %s (%s)", resolved, strerror(errno)); 154 return (NULL); 155 } 156 157 void 158 setblocking(int fd, int state) 159 { 160 int mode; 161 162 if ((mode = fcntl(fd, F_GETFL)) != -1) { 163 if (!state) 164 mode |= O_NONBLOCK; 165 else 166 mode &= ~O_NONBLOCK; 167 fcntl(fd, F_SETFL, mode); 168 } 169 } 170 171 const char * 172 sig2name(int signo) 173 { 174 static char s[11]; 175 176 if (signo > 0 && signo < NSIG) 177 return (sys_signame[signo]); 178 xsnprintf(s, sizeof s, "%d", signo); 179 return (s); 180 } 181 182 const char * 183 find_cwd(void) 184 { 185 char resolved1[PATH_MAX], resolved2[PATH_MAX]; 186 static char cwd[PATH_MAX]; 187 const char *pwd; 188 189 if (getcwd(cwd, sizeof cwd) == NULL) 190 return (NULL); 191 if ((pwd = getenv("PWD")) == NULL || *pwd == '\0') 192 return (cwd); 193 194 /* 195 * We want to use PWD so that symbolic links are maintained, 196 * but only if it matches the actual working directory. 197 */ 198 if (realpath(pwd, resolved1) == NULL) 199 return (cwd); 200 if (realpath(cwd, resolved2) == NULL) 201 return (cwd); 202 if (strcmp(resolved1, resolved2) != 0) 203 return (cwd); 204 return (pwd); 205 } 206 207 const char * 208 find_home(void) 209 { 210 struct passwd *pw; 211 static const char *home; 212 213 if (home != NULL) 214 return (home); 215 216 home = getenv("HOME"); 217 if (home == NULL || *home == '\0') { 218 pw = getpwuid(getuid()); 219 if (pw != NULL) 220 home = pw->pw_dir; 221 else 222 home = NULL; 223 } 224 225 return (home); 226 } 227 228 const char * 229 getversion(void) 230 { 231 static char *version; 232 struct utsname u; 233 234 if (version == NULL) { 235 if (uname(&u) < 0) 236 fatalx("uname failed"); 237 xasprintf(&version, "openbsd-%s", u.release); 238 } 239 return (version); 240 } 241 242 int 243 main(int argc, char **argv) 244 { 245 char *path, *label, *cause, **var; 246 const char *s, *shell, *cwd; 247 int opt, flags, keys; 248 const struct options_table_entry *oe; 249 250 if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL && 251 setlocale(LC_CTYPE, "C.UTF-8") == NULL) { 252 if (setlocale(LC_CTYPE, "") == NULL) 253 errx(1, "invalid LC_ALL, LC_CTYPE or LANG"); 254 s = nl_langinfo(CODESET); 255 if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0) 256 errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s); 257 } 258 259 setlocale(LC_TIME, ""); 260 tzset(); 261 262 if (**argv == '-') 263 flags = CLIENT_LOGIN; 264 else 265 flags = 0; 266 267 label = path = NULL; 268 while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUvV")) != -1) { 269 switch (opt) { 270 case '2': 271 flags |= CLIENT_256COLOURS; 272 break; 273 case 'c': 274 shell_command = optarg; 275 break; 276 case 'C': 277 if (flags & CLIENT_CONTROL) 278 flags |= CLIENT_CONTROLCONTROL; 279 else 280 flags |= CLIENT_CONTROL; 281 break; 282 case 'f': 283 set_cfg_file(optarg); 284 break; 285 case 'V': 286 printf("%s %s\n", getprogname(), getversion()); 287 exit(0); 288 case 'l': 289 flags |= CLIENT_LOGIN; 290 break; 291 case 'L': 292 free(label); 293 label = xstrdup(optarg); 294 break; 295 case 'q': 296 break; 297 case 'S': 298 free(path); 299 path = xstrdup(optarg); 300 break; 301 case 'u': 302 flags |= CLIENT_UTF8; 303 break; 304 case 'v': 305 log_add_level(); 306 break; 307 default: 308 usage(); 309 } 310 } 311 argc -= optind; 312 argv += optind; 313 314 if (shell_command != NULL && argc != 0) 315 usage(); 316 317 if ((ptm_fd = getptmfd()) == -1) 318 err(1, "getptmfd"); 319 if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd " 320 "recvfd proc exec tty ps", NULL) != 0) 321 err(1, "pledge"); 322 323 /* 324 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8. 325 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain 326 * UTF-8, it is a safe assumption that either they are using a UTF-8 327 * terminal, or if not they know that output from UTF-8-capable 328 * programs may be wrong. 329 */ 330 if (getenv("TMUX") != NULL) 331 flags |= CLIENT_UTF8; 332 else { 333 s = getenv("LC_ALL"); 334 if (s == NULL || *s == '\0') 335 s = getenv("LC_CTYPE"); 336 if (s == NULL || *s == '\0') 337 s = getenv("LANG"); 338 if (s == NULL || *s == '\0') 339 s = ""; 340 if (strcasestr(s, "UTF-8") != NULL || 341 strcasestr(s, "UTF8") != NULL) 342 flags |= CLIENT_UTF8; 343 } 344 345 global_environ = environ_create(); 346 for (var = environ; *var != NULL; var++) 347 environ_put(global_environ, *var, 0); 348 if ((cwd = find_cwd()) != NULL) 349 environ_set(global_environ, "PWD", 0, "%s", cwd); 350 351 global_options = options_create(NULL); 352 global_s_options = options_create(NULL); 353 global_w_options = options_create(NULL); 354 for (oe = options_table; oe->name != NULL; oe++) { 355 if (oe->scope & OPTIONS_TABLE_SERVER) 356 options_default(global_options, oe); 357 if (oe->scope & OPTIONS_TABLE_SESSION) 358 options_default(global_s_options, oe); 359 if (oe->scope & OPTIONS_TABLE_WINDOW) 360 options_default(global_w_options, oe); 361 } 362 363 /* 364 * The default shell comes from SHELL or from the user's passwd entry 365 * if available. 366 */ 367 shell = getshell(); 368 options_set_string(global_s_options, "default-shell", 0, "%s", shell); 369 370 /* Override keys to vi if VISUAL or EDITOR are set. */ 371 if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) { 372 if (strrchr(s, '/') != NULL) 373 s = strrchr(s, '/') + 1; 374 if (strstr(s, "vi") != NULL) 375 keys = MODEKEY_VI; 376 else 377 keys = MODEKEY_EMACS; 378 options_set_number(global_s_options, "status-keys", keys); 379 options_set_number(global_w_options, "mode-keys", keys); 380 } 381 382 /* 383 * If socket is specified on the command-line with -S or -L, it is 384 * used. Otherwise, $TMUX is checked and if that fails "default" is 385 * used. 386 */ 387 if (path == NULL && label == NULL) { 388 s = getenv("TMUX"); 389 if (s != NULL && *s != '\0' && *s != ',') { 390 path = xstrdup(s); 391 path[strcspn(path, ",")] = '\0'; 392 } 393 } 394 if (path == NULL) { 395 if ((path = make_label(label, &cause)) == NULL) { 396 if (cause != NULL) { 397 fprintf(stderr, "%s\n", cause); 398 free(cause); 399 } 400 exit(1); 401 } 402 flags |= CLIENT_DEFAULTSOCKET; 403 } 404 socket_path = path; 405 free(label); 406 407 /* Pass control to the client. */ 408 exit(client_main(event_init(), argc, argv, flags)); 409 } 410