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 <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         free(path);
 215         if (mkdir(base, S_IRWXU) != 0 && errno != EEXIST) {
 216                 xasprintf(cause, "couldn't create directory %s (%s)", base,
 217                     strerror(errno));
 218                 goto fail;
 219         }
 220         if (lstat(base, &sb) != 0) {
 221                 xasprintf(cause, "couldn't read directory %s (%s)", base,
 222                     strerror(errno));
 223                 goto fail;
 224         }
 225         if (!S_ISDIR(sb.st_mode)) {
 226                 xasprintf(cause, "%s is not a directory", base);
 227                 goto fail;
 228         }
 229         if (sb.st_uid != uid || (sb.st_mode & TMUX_SOCK_PERM) != 0) {
 230                 xasprintf(cause, "directory %s has unsafe permissions", base);
 231                 goto fail;
 232         }
 233         xasprintf(&path, "%s/%s", base, label);
 234         free(base);
 235         return (path);
 236
 237 fail:
 238         free(base);
 239         return (NULL);
 240 }
 241
 242 char *
 243 shell_argv0(const char *shell, int is_login)
 244 {
 245         const char      *slash, *name;
 246         char            *argv0;
 247
 248         slash = strrchr(shell, '/');
 249         if (slash != NULL && slash[1] != '\0')
 250                 name = slash + 1;
 251         else
 252                 name = shell;
 253         if (is_login)
 254                 xasprintf(&argv0, "-%s", name);
 255         else
 256                 xasprintf(&argv0, "%s", name);
 257         return (argv0);
 258 }
 259
 260 void
 261 setblocking(int fd, int state)
 262 {
 263         int mode;
 264
 265         if ((mode = fcntl(fd, F_GETFL)) != -1) {
 266                 if (!state)
 267                         mode |= O_NONBLOCK;
 268                 else
 269                         mode &= ~O_NONBLOCK;
 270                 fcntl(fd, F_SETFL, mode);
 271         }
 272 }
 273
 274 uint64_t
 275 get_timer(void)
 276 {
 277         struct timespec ts;
 278
 279         /*
 280          * We want a timestamp in milliseconds suitable for time measurement,
 281          * so prefer the monotonic clock.
 282          */
 283         if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
 284                 clock_gettime(CLOCK_REALTIME, &ts);
 285         return ((ts.tv_sec * 1000ULL) + (ts.tv_nsec / 1000000ULL));
 286 }
 287
 288 const char *
 289 sig2name(int signo)
 290 {
 291      static char        s[11];
 292
 293      if (signo > 0 && signo < NSIG)
 294              return (sys_signame[signo]);
 295      xsnprintf(s, sizeof s, "%d", signo);
 296      return (s);
 297 }
 298
 299 const char *
 300 find_cwd(void)
 301 {
 302         char             resolved1[PATH_MAX], resolved2[PATH_MAX];
 303         static char      cwd[PATH_MAX];
 304         const char      *pwd;
 305
 306         if (getcwd(cwd, sizeof cwd) == NULL)
 307                 return (NULL);
 308         if ((pwd = getenv("PWD")) == NULL || *pwd == '\0')
 309                 return (cwd);
 310
 311         /*
 312          * We want to use PWD so that symbolic links are maintained,
 313          * but only if it matches the actual working directory.
 314          */
 315         if (realpath(pwd, resolved1) == NULL)
 316                 return (cwd);
 317         if (realpath(cwd, resolved2) == NULL)
 318                 return (cwd);
 319         if (strcmp(resolved1, resolved2) != 0)
 320                 return (cwd);
 321         return (pwd);
 322 }
 323
 324 const char *
 325 find_home(void)
 326 {
 327         struct passwd           *pw;
 328         static const char       *home;
 329
 330         if (home != NULL)
 331                 return (home);
 332
 333         home = getenv("HOME");
 334         if (home == NULL || *home == '\0') {
 335                 pw = getpwuid(getuid());
 336                 if (pw != NULL)
 337                         home = pw->pw_dir;
 338                 else
 339                         home = NULL;
 340         }
 341
 342         return (home);
 343 }
 344
 345 const char *
 346 getversion(void)
 347 {
 348         static char     *version;
 349         struct utsname   u;
 350
 351         if (version == NULL) {
 352                 if (uname(&u) < 0)
 353                         fatalx("uname failed");
 354                 xasprintf(&version, "openbsd-%s", u.release);
 355         }
 356         return (version);
 357 }
 358
 359 int
 360 main(int argc, char **argv)
 361 {
 362         char                                    *path = NULL, *label = NULL;
 363         char                                    *cause, **var;
 364         const char                              *s, *cwd;
 365         int                                      opt, keys, feat = 0, fflag = 0;
 366         uint64_t                                 flags = 0;
 367         const struct options_table_entry        *oe;
 368         u_int                                    i;
 369
 370         if (setlocale(LC_CTYPE, "en_US.UTF-8") == NULL &&
 371             setlocale(LC_CTYPE, "C.UTF-8") == NULL) {
 372                 if (setlocale(LC_CTYPE, "") == NULL)
 373                         errx(1, "invalid LC_ALL, LC_CTYPE or LANG");
 374                 s = nl_langinfo(CODESET);
 375                 if (strcasecmp(s, "UTF-8") != 0 && strcasecmp(s, "UTF8") != 0)
 376                         errx(1, "need UTF-8 locale (LC_CTYPE) but have %s", s);
 377         }
 378
 379         setlocale(LC_TIME, "");
 380         tzset();
 381
 382         if (**argv == '-')
 383                 flags = CLIENT_LOGIN;
 384
 385         global_environ = environ_create();
 386         for (var = environ; *var != NULL; var++)
 387                 environ_put(global_environ, *var, 0);
 388         if ((cwd = find_cwd()) != NULL)
 389                 environ_set(global_environ, "PWD", 0, "%s", cwd);
 390         expand_paths(TMUX_CONF, &cfg_files, &cfg_nfiles, 1);
 391
 392         while ((opt = getopt(argc, argv, "2c:CDdf:lL:NqS:T:uUvV")) != -1) {
 393                 switch (opt) {
 394                 case '2':
 395                         tty_add_features(&feat, "256", ":,");
 396                         break;
 397                 case 'c':
 398                         shell_command = optarg;
 399                         break;
 400                 case 'D':
 401                         flags |= CLIENT_NOFORK;
 402                         break;
 403                 case 'C':
 404                         if (flags & CLIENT_CONTROL)
 405                                 flags |= CLIENT_CONTROLCONTROL;
 406                         else
 407                                 flags |= CLIENT_CONTROL;
 408                         break;
 409                 case 'f':
 410                         if (!fflag) {
 411                                 fflag = 1;
 412                                 for (i = 0; i < cfg_nfiles; i++)
 413                                         free(cfg_files[i]);
 414                                 cfg_nfiles = 0;
 415                         }
 416                         cfg_files = xreallocarray(cfg_files, cfg_nfiles + 1,
 417                             sizeof *cfg_files);
 418                         cfg_files[cfg_nfiles++] = xstrdup(optarg);
 419                         cfg_quiet = 0;
 420                         break;
 421                 case 'V':
 422                         printf("tmux %s\n", getversion());
 423                         exit(0);
 424                 case 'l':
 425                         flags |= CLIENT_LOGIN;
 426                         break;
 427                 case 'L':
 428                         free(label);
 429                         label = xstrdup(optarg);
 430                         break;
 431                 case 'N':
 432                         flags |= CLIENT_NOSTARTSERVER;
 433                         break;
 434                 case 'q':
 435                         break;
 436                 case 'S':
 437                         free(path);
 438                         path = xstrdup(optarg);
 439                         break;
 440                 case 'T':
 441                         tty_add_features(&feat, optarg, ":,");
 442                         break;
 443                 case 'u':
 444                         flags |= CLIENT_UTF8;
 445                         break;
 446                 case 'v':
 447                         log_add_level();
 448                         break;
 449                 default:
 450                         usage();
 451                 }
 452         }
 453         argc -= optind;
 454         argv += optind;
 455
 456         if (shell_command != NULL && argc != 0)
 457                 usage();
 458         if ((flags & CLIENT_NOFORK) && argc != 0)
 459                 usage();
 460
 461         if ((ptm_fd = getptmfd()) == -1)
 462                 err(1, "getptmfd");
 463         if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
 464             "recvfd proc exec tty ps", NULL) != 0)
 465                 err(1, "pledge");
 466
 467         /*
 468          * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
 469          * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
 470          * UTF-8, it is a safe assumption that either they are using a UTF-8
 471          * terminal, or if not they know that output from UTF-8-capable
 472          * programs may be wrong.
 473          */
 474         if (getenv("TMUX") != NULL)
 475                 flags |= CLIENT_UTF8;
 476         else {
 477                 s = getenv("LC_ALL");
 478                 if (s == NULL || *s == '\0')
 479                         s = getenv("LC_CTYPE");
 480                 if (s == NULL || *s == '\0')
 481                         s = getenv("LANG");
 482                 if (s == NULL || *s == '\0')
 483                         s = "";
 484                 if (strcasestr(s, "UTF-8") != NULL ||
 485                     strcasestr(s, "UTF8") != NULL)
 486                         flags |= CLIENT_UTF8;
 487         }
 488
 489         global_options = options_create(NULL);
 490         global_s_options = options_create(NULL);
 491         global_w_options = options_create(NULL);
 492         for (oe = options_table; oe->name != NULL; oe++) {
 493                 if (oe->scope & OPTIONS_TABLE_SERVER)
 494                         options_default(global_options, oe);
 495                 if (oe->scope & OPTIONS_TABLE_SESSION)
 496                         options_default(global_s_options, oe);
 497                 if (oe->scope & OPTIONS_TABLE_WINDOW)
 498                         options_default(global_w_options, oe);
 499         }
 500
 501         /*
 502          * The default shell comes from SHELL or from the user's passwd entry
 503          * if available.
 504          */
 505         options_set_string(global_s_options, "default-shell", 0, "%s",
 506             getshell());
 507
 508         /* Override keys to vi if VISUAL or EDITOR are set. */
 509         if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
 510                 options_set_string(global_options, "editor", 0, "%s", s);
 511                 if (strrchr(s, '/') != NULL)
 512                         s = strrchr(s, '/') + 1;
 513                 if (strstr(s, "vi") != NULL)
 514                         keys = MODEKEY_VI;
 515                 else
 516                         keys = MODEKEY_EMACS;
 517                 options_set_number(global_s_options, "status-keys", keys);
 518                 options_set_number(global_w_options, "mode-keys", keys);
 519         }
 520
 521         /*
 522          * If socket is specified on the command-line with -S or -L, it is
 523          * used. Otherwise, $TMUX is checked and if that fails "default" is
 524          * used.
 525          */
 526         if (path == NULL && label == NULL) {
 527                 s = getenv("TMUX");
 528                 if (s != NULL && *s != '\0' && *s != ',') {
 529                         path = xstrdup(s);
 530                         path[strcspn(path, ",")] = '\0';
 531                 }
 532         }
 533         if (path == NULL) {
 534                 if ((path = make_label(label, &cause)) == NULL) {
 535                         if (cause != NULL) {
 536                                 fprintf(stderr, "%s\n", cause);
 537                                 free(cause);
 538                         }
 539                         exit(1);
 540                 }
 541                 flags |= CLIENT_DEFAULTSOCKET;
 542         }
 543         socket_path = path;
 544         free(label);
 545
 546         /* Pass control to the client. */
 547         exit(client_main(event_init(), argc, argv, flags, feat));
 548 }