tmux.c

   1 /* $OpenBSD$ */
   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 <errno.h>
  24 #include <fcntl.h>
  25 #include <langinfo.h>
  26 #include <locale.h>
  27 #include <pwd.h>
  28 #include <signal.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <time.h>
  32 #include <unistd.h>
  33
  34 #include "tmux.h"
  35
  36 struct options  *global_options;        /* server options */
  37 struct options  *global_s_options;      /* session options */
  38 struct options  *global_w_options;      /* window options */
  39 struct environ  *global_environ;
  40
  41 struct timeval   start_time;
  42 const char      *socket_path;
  43 int              ptm_fd = -1;
  44 const char      *shell_command;
  45
  46 static __dead void       usage(void);
  47 static char             *make_label(const char *, char **);
  48
  49 static int               areshell(const char *);
  50 static const char       *getshell(void);
  51
  52 static __dead void
  53 usage(void)
  54 {
  55         fprintf(stderr,
  56             "usage: %s [-2CDlNuVv] [-c shell-command] [-f file] [-L socket-name]\n"
  57             "            [-S socket-path] [-T features] [command [flags]]\n",
  58             getprogname());
  59         exit(1);
  60 }
  61
  62 static const char *
  63 getshell(void)
  64 {
  65         struct passwd   *pw;
  66         const char      *shell;
  67
  68         shell = getenv("SHELL");
  69         if (checkshell(shell))
  70                 return (shell);
  71
  72         pw = getpwuid(getuid());
  73         if (pw != NULL && checkshell(pw->pw_shell))
  74                 return (pw->pw_shell);
  75
  76         return (_PATH_BSHELL);
  77 }
  78
  79 int
  80 checkshell(const char *shell)
  81 {
  82         if (shell == NULL || *shell != '/')
  83                 return (0);
  84         if (areshell(shell))
  85                 return (0);
  86         if (access(shell, X_OK) != 0)
  87                 return (0);
  88         return (1);
  89 }
  90
  91 static int
  92 areshell(const char *shell)
  93 {
  94         const char      *progname, *ptr;
  95
  96         if ((ptr = strrchr(shell, '/')) != NULL)
  97                 ptr++;
  98         else
  99                 ptr = shell;
 100         progname = getprogname();
 101         if (*progname == '-')
 102                 progname++;
 103         if (strcmp(ptr, progname) == 0)
 104                 return (1);
 105         return (0);
 106 }
 107
 108 static char *
 109 expand_path(const char *path, const char *home)
 110 {
 111         char                    *expanded, *name;
 112         const char              *end;
 113         struct environ_entry    *value;
 114
 115         if (strncmp(path, "~/", 2) == 0) {
 116                 if (home == NULL)
 117                         return (NULL);
 118                 xasprintf(&expanded, "%s%s", home, path + 1);
 119                 return (expanded);
 120         }
 121
 122         if (*path == '$') {
 123                 end = strchr(path, '/');
 124                 if (end == NULL)
 125                         name = xstrdup(path + 1);
 126                 else
 127                         name = xstrndup(path + 1, end - path - 1);
 128                 value = environ_find(global_environ, name);
 129                 free(name);
 130                 if (value == NULL)
 131                         return (NULL);
 132                 if (end == NULL)
 133                         end = "";
 134                 xasprintf(&expanded, "%s%s", value->value, end);
 135                 return (expanded);
 136         }
 137
 138         return (xstrdup(path));
 139 }
 140
 141 static void
 142 expand_paths(const char *s, char ***paths, u_int *n, int ignore_errors)
 143 {
 144         const char      *home = find_home();
 145         char            *copy, *next, *tmp, resolved[PATH_MAX], *expanded;
 146         char            *path;
 147         u_int            i;
 148
 149         *paths = NULL;
 150         *n = 0;
 151
 152         copy = tmp = xstrdup(s);
 153         while ((next = strsep(&tmp, ":")) != NULL) {
 154                 expanded = expand_path(next, home);
 155                 if (expanded == NULL) {
 156                         log_debug("%s: invalid path: %s", __func__, next);
 157                         continue;
 158                 }
 159                 if (realpath(expanded, resolved) == NULL) {
 160                         log_debug("%s: realpath(\"%s\") failed: %s", __func__,
 161                             expanded, strerror(errno));
 162                         if (ignore_errors) {
 163                                 free(expanded);
 164                                 continue;
 165                         }
 166                         path = expanded;
 167                 } else {
 168                         path = xstrdup(resolved);
 169                         free(expanded);
 170                 }
 171                 for (i = 0; i < *n; i++) {
 172                         if (strcmp(path, (*paths)[i]) == 0)
 173                                 break;
 174                 }
 175                 if (i != *n) {
 176                         log_debug("%s: duplicate path: %s", __func__, path);
 177                         free(path);
 178                         continue;
 179                 }
 180                 *paths = xreallocarray(*paths, (*n) + 1, sizeof *paths);
 181                 (*paths)[(*n)++] = path;
 182         }
 183         free(copy);
 184 }
 185
 186 static char *
 187 make_label(const char *label, char **cause)
 188 {
 189         char            **paths, *path, *base;
 190         u_int             i, n;
 191         struct stat       sb;
 192         uid_t             uid;
 193
 194         *cause = NULL;
 195         if (label == NULL)
 196                 label = "default";
 197         uid = getuid();
 198
 199         expand_paths(TMUX_SOCK, &paths, &n, 1);
 200         if (n == 0) {
 201                 xasprintf(cause, "no suitable socket path");
 202                 return (NULL);
 203         }
 204         path = paths[0]; /* can only have one socket! */
 205         for (i = 1; i < n; i++)
 206                 free(paths[i]);
 207         free(paths);
 208
 209         xasprintf(&base, "%s/tmux-%ld", path, (long)uid);
 210         free(path);
 211         if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
 212                 xasprintf(cause, "couldn't create directory %s (%s)", base,
 213                     strerror(errno));
 214                 goto fail;
 215         }
 216         if (lstat(base, &sb) != 0) {
 217                 xasprintf(cause, "couldn't read directory %s (%s)", base,
 218                     strerror(errno));
 219                 goto fail;
 220         }
 221         if (!S_ISDIR(sb.st_mode)) {
 222                 xasprintf(cause, "%s is not a directory", base);
 223                 goto fail;
 224         }
 225         if (sb.st_uid != uid || (sb.st_mode & TMUX_SOCK_PERM) != 0) {
 226                 xasprintf(cause, "directory %s has unsafe permissions", base);
 227                 goto fail;
 228         }
 229         xasprintf(&path, "%s/%s", base, label);
 230         free(base);
 231         return (path);
 232
 233 fail:
 234         free(base);
 235         return (NULL);
 236 }
 237
 238 char *
 239 shell_argv0(const char *shell, int is_login)
 240 {
 241         const char      *slash, *name;
 242         char            *argv0;
 243
 244         slash = strrchr(shell, '/');
 245         if (slash != NULL && slash[1] != '\0')
 246                 name = slash + 1;
 247         else
 248                 name = shell;
 249         if (is_login)
 250                 xasprintf(&argv0, "-%s", name);
 251         else
 252                 xasprintf(&argv0, "%s", name);
 253         return (argv0);
 254 }
 255
 256 void
 257 setblocking(int fd, int state)
 258 {
 259         int mode;
 260
 261         if ((mode = fcntl(fd, F_GETFL)) != -1) {
 262                 if (!state)
 263                         mode |= O_NONBLOCK;
 264                 else
 265                         mode &= ~O_NONBLOCK;
 266                 fcntl(fd, F_SETFL, mode);
 267         }
 268 }
 269
 270 uint64_t
 271 get_timer(void)
 272 {
 273         struct timespec ts;
 274
 275         /*
 276          * We want a timestamp in milliseconds suitable for time measurement,
 277          * so prefer the monotonic clock.
 278          */
 279         if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
 280                 clock_gettime(CLOCK_REALTIME, &ts);
 281         return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL));
 282 }
 283
 284 const char *
 285 sig2name(int signo)
 286 {
 287      static char        s[11];
 288
 289 #ifdef HAVE_SYS_SIGNAME
 290      if (signo > 0 && signo < NSIG)
 291              return (sys_signame[signo]);
 292 #endif
 293      xsnprintf(s, sizeof s, "%d", signo);
 294      return (s);
 295 }
 296
 297 const char *
 298 find_cwd(void)
 299 {
 300         char             resolved1[PATH_MAX], resolved2[PATH_MAX];
 301         static char      cwd[PATH_MAX];
 302         const char      *pwd;
 303
 304         if (getcwd(cwd, sizeof cwd) == NULL)
 305                 return (NULL);
 306         if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
 307                 return (cwd);
 308
 309         /*
 310          * We want to use PWD so that symbolic links are maintained,
 311          * but only if it matches the actual working directory.
 312          */
 313         if (realpath(pwd, resolved1) == NULL)
 314                 return (cwd);
 315         if (realpath(cwd, resolved2) == NULL)
 316                 return (cwd);
 317         if (strcmp(resolved1, resolved2) != 0)
 318                 return (cwd);
 319         return (pwd);
 320 }
 321
 322 const char *
 323 find_home(void)
 324 {
 325         struct passwd           *pw;
 326         static const char       *home;
 327
 328         if (home != NULL)
 329                 return (home);
 330
 331         home = getenv("HOME");
 332         if (home == NULL || *home == '\0') {
 333                 pw = getpwuid(getuid());
 334                 if (pw != NULL)
 335                         home = pw->pw_dir;
 336                 else
 337                         home = NULL;
 338         }
 339
 340         return (home);
 341 }
 342
 343 const char *
 344 getversion(void)
 345 {
 346         return (TMUX_VERSION);
 347 }
 348
 349 int
 350 main(int argc, char **argv)
 351 {
 352         char                                    *path = NULL, *label = NULL;
 353         char                                    *cause, **var;
 354         const char                              *s, *cwd;
 355         int                                      opt, keys, feat = 0, fflag = 0;
 356         uint64_t                                 flags = 0;
 357         const struct options_table_entry        *oe;
 358         u_int                                    i;
 359
 360         if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
 361             setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
 362                 if (setlocale(LC_CTYPE, "") == NULL)
 363                         errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
 364                 s = nl_langinfo(CODESET);
 365                 if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
 366                         errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
 367         }
 368
 369         setlocale(LC_TIME, "");
 370         tzset();
 371
 372         if (**argv == '-')
 373                 flags = CLIENT_LOGIN;
 374
 375         global_environ = environ_create();
 376         for (var = environ; *var != NULL; var++)
 377                 environ_put(global_environ, *var, 0);
 378         if ((cwd = find_cwd()) != NULL)
 379                 environ_set(global_environ, "PWD", 0, "%s", cwd);
 380         expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1);
 381
 382         while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) {
 383                 switch (opt) {
 384                 case '2':
 385                         tty_add_features(&feat, "256", ":,");
 386                         break;
 387                 case 'c':
 388                         shell_command = optarg;
 389                         break;
 390                 case 'D':
 391                         flags |= CLIENT_NOFORK;
 392                         break;
 393                 case 'C':
 394                         if (flags & CLIENT_CONTROL)
 395                                 flags |= CLIENT_CONTROLCONTROL;
 396                         else
 397                                 flags |= CLIENT_CONTROL;
 398                         break;
 399                 case 'f':
 400                         if (!fflag) {
 401                                 fflag = 1;
 402                                 for (i = 0; i < cfg_nfiles; i++)
 403                                         free(cfg_files[i]);
 404                                 cfg_nfiles = 0;
 405                         }
 406                         cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1,
 407                             sizeof *cfg_files);
 408                         cfg_files[cfg_nfiles++] = xstrdup(optarg);
 409                         cfg_quiet = 0;
 410                         break;
 411                 case 'V':
 412                         printf("tmux %s\n", getversion());
 413                         exit(0);
 414                 case 'l':
 415                         flags |= CLIENT_LOGIN;
 416                         break;
 417                 case 'L':
 418                         free(label);
 419                         label = xstrdup(optarg);
 420                         break;
 421                 case 'N':
 422                         flags |= CLIENT_NOSTARTSERVER;
 423                         break;
 424                 case 'q':
 425                         break;
 426                 case 'S':
 427                         free(path);
 428                         path = xstrdup(optarg);
 429                         break;
 430                 case 'T':
 431                         tty_add_features(&feat, optarg, ":,");
 432                         break;
 433                 case 'u':
 434                         flags |= CLIENT_UTF8;
 435                         break;
 436                 case 'v':
 437                         log_add_level();
 438                         break;
 439                 default:
 440                         usage();
 441                 }
 442         }
 443         argc -= optind;
 444         argv += optind;
 445
 446         if (shell_command != NULL && argc != 0)
 447                 usage();
 448         if ((flags & CLIENT_NOFORK) && argc != 0)
 449                 usage();
 450
 451         if ((ptm_fd = getptmfd()) == -1)
 452                 err(1, "getptmfd");
 453         if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
 454             "recvfd proc exec tty ps", NULL) != 0)
 455                 err(1, "pledge");
 456
 457         /*
 458          * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
 459          * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
 460          * UTF-8, it is a safe assumption that either they are using a UTF-8
 461          * terminal, or if not they know that output from UTF-8-capable
 462          * programs may be wrong.
 463          */
 464         if (getenv("TMUX") != NULL)
 465                 flags |= CLIENT_UTF8;
 466         else {
 467                 s = getenv("LC_ALL");
 468                 if (s == NULL || *s == '\0')
 469                         s = getenv("LC_CTYPE");
 470                 if (s == NULL || *s == '\0')
 471                         s = getenv("LANG");
 472                 if (s == NULL || *s == '\0')
 473                         s = "";
 474                 if (strcasestr(s, "UTF-8") != NULL ||
 475                     strcasestr(s, "UTF8") != NULL)
 476                         flags |= CLIENT_UTF8;
 477         }
 478
 479         global_options = options_create(NULL);
 480         global_s_options = options_create(NULL);
 481         global_w_options = options_create(NULL);
 482         for (oe = options_table; oe->name != NULL; oe++) {
 483                 if (oe->scope & OPTIONS_TABLE_SERVER)
 484                         options_default(global_options, oe);
 485                 if (oe->scope & OPTIONS_TABLE_SESSION)
 486                         options_default(global_s_options, oe);
 487                 if (oe->scope & OPTIONS_TABLE_WINDOW)
 488                         options_default(global_w_options, oe);
 489         }
 490
 491         /*
 492          * The default shell comes from SHELL or from the user's passwd entry
 493          * if available.
 494          */
 495         options_set_string(global_s_options, "default-shell", 0, "%s",
 496             getshell());
 497
 498         /* Override keys to vi if VISUAL or EDITOR are set. */
 499         if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
 500                 options_set_string(global_options, "editor", 0, "%s", s);
 501                 if (strrchr(s, '/') != NULL)
 502                         s = strrchr(s, '/') + 1;
 503                 if (strstr(s, "vi") != NULL)
 504                         keys = MODEKEY_VI;
 505                 else
 506                         keys = MODEKEY_EMACS;
 507                 options_set_number(global_s_options, "status-keys", keys);
 508                 options_set_number(global_w_options, "mode-keys", keys);
 509         }
 510
 511         /*
 512          * If socket is specified on the command-line with -S or -L, it is
 513          * used. Otherwise, $TMUX is checked and if that fails "default" is
 514          * used.
 515          */
 516         if (path == NULL && label == NULL) {
 517                 s = getenv("TMUX");
 518                 if (s != NULL && *s != '\0' && *s != ',') {
 519                         path = xstrdup(s);
 520                         path[strcspn(path, ",")] = '\0';
 521                 }
 522         }
 523         if (path == NULL) {
 524                 if ((path = make_label(label, &cause)) == NULL) {
 525                         if (cause != NULL) {
 526                                 fprintf(stderr, "%s\n", cause);
 527                                 free(cause);
 528                         }
 529                         exit(1);
 530                 }
 531                 flags |= CLIENT_DEFAULTSOCKET;
 532         }
 533         socket_path = path;
 534         free(label);
 535
 536         /* Pass control to the client. */
 537         exit(client_main(osdep_event_init(), argc, argv, flags, feat));
 538 }