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