1 /* $OpenBSD: tmux.c,v 1.190 2019/10/14 08:38:07 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 22 #include <err.h> 23 #include <errno.h> 24 #include <event.h> 25 #include <fcntl.h> 26 #include <langinfo.h> 27 #include <locale.h> 28 #include <paths.h> 29 #include <pwd.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #include <time.h> 33 #include <unistd.h> 34 #include <util.h> 35 36 #include "tmux.h" 37 38 struct options *global_options; /* server options */ 39 struct options *global_s_options; /* session options */ 40 struct options *global_w_options; /* window options */ 41 struct environ *global_environ; 42 43 struct timeval start_time; 44 const char *socket_path; 45 int ptm_fd = -1; 46 const char *shell_command; 47 48 static __dead void usage(void); 49 static char *make_label(const char *, char **); 50 51 static const char *getshell(void); 52 static int checkshell(const char *); 53 54 static __dead void 55 usage(void) 56 { 57 fprintf(stderr, 58 "usage: %s [-2Cluv] [-c shell-command] [-f file] [-L socket-name]\n" 59 " [-S socket-path] [command [flags]]\n", 60 getprogname()); 61 exit(1); 62 } 63 64 static const char * 65 getshell(void) 66 { 67 struct passwd *pw; 68 const char *shell; 69 70 shell = getenv("SHELL"); 71 if (checkshell(shell)) 72 return (shell); 73 74 pw = getpwuid(getuid()); 75 if (pw != NULL && checkshell(pw->pw_shell)) 76 return (pw->pw_shell); 77 78 return (_PATH_BSHELL); 79 } 80 81 static int 82 checkshell(const char *shell) 83 { 84 if (shell == NULL || *shell != '/') 85 return (0); 86 if (areshell(shell)) 87 return (0); 88 if (access(shell, X_OK) != 0) 89 return (0); 90 return (1); 91 } 92 93 int 94 areshell(const char *shell) 95 { 96 const char *progname, *ptr; 97 98 if ((ptr = strrchr(shell, '/')) != NULL) 99 ptr++; 100 else 101 ptr = shell; 102 progname = getprogname(); 103 if (*progname == '-') 104 progname++; 105 if (strcmp(ptr, progname) == 0) 106 return (1); 107 return (0); 108 } 109 110 static char * 111 make_label(const char *label, char **cause) 112 { 113 char *base, resolved[PATH_MAX], *path, *s; 114 struct stat sb; 115 uid_t uid; 116 117 *cause = NULL; 118 119 if (label == NULL) 120 label = "default"; 121 uid = getuid(); 122 123 if ((s = getenv("TMUX_TMPDIR")) != NULL && *s != '\0') 124 xasprintf(&base, "%s/tmux-%ld", s, (long)uid); 125 else 126 xasprintf(&base, "%s/tmux-%ld", _PATH_TMP, (long)uid); 127 if (realpath(base, resolved) == NULL && 128 strlcpy(resolved, base, sizeof resolved) >= sizeof resolved) { 129 errno = ERANGE; 130 free(base); 131 goto fail; 132 } 133 free(base); 134 135 if (mkdir(resolved, S_IRWXU) != 0 && errno != EEXIST) 136 goto fail; 137 if (lstat(resolved, &sb) != 0) 138 goto fail; 139 if (!S_ISDIR(sb.st_mode)) { 140 errno = ENOTDIR; 141 goto fail; 142 } 143 if (sb.st_uid != uid || (sb.st_mode & S_IRWXO) != 0) { 144 errno = EACCES; 145 goto fail; 146 } 147 xasprintf(&path, "%s/%s", resolved, label); 148 return (path); 149 150 fail: 151 xasprintf(cause, "error creating %s (%s)", resolved, strerror(errno)); 152 return (NULL); 153 } 154 155 void 156 setblocking(int fd, int state) 157 { 158 int mode; 159 160 if ((mode = fcntl(fd, F_GETFL)) != -1) { 161 if (!state) 162 mode |= O_NONBLOCK; 163 else 164 mode &= ~O_NONBLOCK; 165 fcntl(fd, F_SETFL, mode); 166 } 167 } 168 169 const char * 170 find_cwd(void) 171 { 172 char resolved1[PATH_MAX], resolved2[PATH_MAX]; 173 static char cwd[PATH_MAX]; 174 const char *pwd; 175 176 if (getcwd(cwd, sizeof cwd) == NULL) 177 return (NULL); 178 if ((pwd = getenv("PWD")) == NULL || *pwd == '\0') 179 return (cwd); 180 181 /* 182 * We want to use PWD so that symbolic links are maintained, 183 * but only if it matches the actual working directory. 184 */ 185 if (realpath(pwd, resolved1) == NULL) 186 return (cwd); 187 if (realpath(cwd, resolved2) == NULL) 188 return (cwd); 189 if (strcmp(resolved1, resolved2) != 0) 190 return (cwd); 191 return (pwd); 192 } 193 194 const char * 195 find_home(void) 196 { 197 struct passwd *pw; 198 static const char *home; 199 200 if (home != NULL) 201 return (home); 202 203 home = getenv("HOME"); 204 if (home == NULL || *home == '\0') { 205 pw = getpwuid(getuid()); 206 if (pw != NULL) 207 home = pw->pw_dir; 208 else 209 home = NULL; 210 } 211 212 return (home); 213 } 214 215 int 216 main(int argc, char **argv) 217 { 218 char *path, *label, *cause, **var; 219 const char *s, *shell, *cwd; 220 int opt, flags, keys; 221 const struct options_table_entry *oe; 222 223 if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL && 224 setlocale(LC_CTYPE, "C.UTF-8") == NULL) { 225 if (setlocale(LC_CTYPE, "") == NULL) 226 errx(1, "invalid LC_ALL, LC_CTYPE or LANG"); 227 s = nl_langinfo(CODESET); 228 if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0) 229 errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s); 230 } 231 232 setlocale(LC_TIME, ""); 233 tzset(); 234 235 if (**argv == '-') 236 flags = CLIENT_LOGIN; 237 else 238 flags = 0; 239 240 label = path = NULL; 241 while ((opt = getopt(argc, argv, "2c:Cdf:lL:qS:uUv")) != -1) { 242 switch (opt) { 243 case '2': 244 flags |= CLIENT_256COLOURS; 245 break; 246 case 'c': 247 shell_command = optarg; 248 break; 249 case 'C': 250 if (flags & CLIENT_CONTROL) 251 flags |= CLIENT_CONTROLCONTROL; 252 else 253 flags |= CLIENT_CONTROL; 254 break; 255 case 'f': 256 set_cfg_file(optarg); 257 break; 258 case 'l': 259 flags |= CLIENT_LOGIN; 260 break; 261 case 'L': 262 free(label); 263 label = xstrdup(optarg); 264 break; 265 case 'q': 266 break; 267 case 'S': 268 free(path); 269 path = xstrdup(optarg); 270 break; 271 case 'u': 272 flags |= CLIENT_UTF8; 273 break; 274 case 'v': 275 log_add_level(); 276 break; 277 default: 278 usage(); 279 } 280 } 281 argc -= optind; 282 argv += optind; 283 284 if (shell_command != NULL && argc != 0) 285 usage(); 286 287 if ((ptm_fd = getptmfd()) == -1) 288 err(1, "getptmfd"); 289 if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd " 290 "recvfd proc exec tty ps", NULL) != 0) 291 err(1, "pledge"); 292 293 /* 294 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8. 295 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain 296 * UTF-8, it is a safe assumption that either they are using a UTF-8 297 * terminal, or if not they know that output from UTF-8-capable 298 * programs may be wrong. 299 */ 300 if (getenv("TMUX") != NULL) 301 flags |= CLIENT_UTF8; 302 else { 303 s = getenv("LC_ALL"); 304 if (s == NULL || *s == '\0') 305 s = getenv("LC_CTYPE"); 306 if (s == NULL || *s == '\0') 307 s = getenv("LANG"); 308 if (s == NULL || *s == '\0') 309 s = ""; 310 if (strcasestr(s, "UTF-8") != NULL || 311 strcasestr(s, "UTF8") != NULL) 312 flags |= CLIENT_UTF8; 313 } 314 315 global_environ = environ_create(); 316 for (var = environ; *var != NULL; var++) 317 environ_put(global_environ, *var); 318 if ((cwd = find_cwd()) != NULL) 319 environ_set(global_environ, "PWD", "%s", cwd); 320 321 global_options = options_create(NULL); 322 global_s_options = options_create(NULL); 323 global_w_options = options_create(NULL); 324 for (oe = options_table; oe->name != NULL; oe++) { 325 if (oe->scope & OPTIONS_TABLE_SERVER) 326 options_default(global_options, oe); 327 if (oe->scope & OPTIONS_TABLE_SESSION) 328 options_default(global_s_options, oe); 329 if (oe->scope & OPTIONS_TABLE_WINDOW) 330 options_default(global_w_options, oe); 331 } 332 333 /* 334 * The default shell comes from SHELL or from the user's passwd entry 335 * if available. 336 */ 337 shell = getshell(); 338 options_set_string(global_s_options, "default-shell", 0, "%s", shell); 339 340 /* Override keys to vi if VISUAL or EDITOR are set. */ 341 if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) { 342 if (strrchr(s, '/') != NULL) 343 s = strrchr(s, '/') + 1; 344 if (strstr(s, "vi") != NULL) 345 keys = MODEKEY_VI; 346 else 347 keys = MODEKEY_EMACS; 348 options_set_number(global_s_options, "status-keys", keys); 349 options_set_number(global_w_options, "mode-keys", keys); 350 } 351 352 /* 353 * If socket is specified on the command-line with -S or -L, it is 354 * used. Otherwise, $TMUX is checked and if that fails "default" is 355 * used. 356 */ 357 if (path == NULL && label == NULL) { 358 s = getenv("TMUX"); 359 if (s != NULL && *s != '\0' && *s != ',') { 360 path = xstrdup(s); 361 path[strcspn(path, ",")] = '\0'; 362 } 363 } 364 if (path == NULL && (path = make_label(label, &cause)) == NULL) { 365 if (cause != NULL) { 366 fprintf(stderr, "%s\n", cause); 367 free(cause); 368 } 369 exit(1); 370 } 371 socket_path = path; 372 free(label); 373 374 /* Pass control to the client. */ 375 exit(client_main(event_init(), argc, argv, flags)); 376 } 377