1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ 2 /* main.c main() for message bus 3 * 4 * Copyright (C) 2003 Red Hat, Inc. 5 * 6 * Licensed under the Academic Free License version 2.1 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 * 22 */ 23 24 #include <config.h> 25 #include "bus.h" 26 #include "driver.h" 27 #include <dbus/dbus-internals.h> 28 #include <dbus/dbus-watch.h> 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #ifdef HAVE_SIGNAL_H 33 #include <signal.h> 34 #endif 35 #ifdef HAVE_ERRNO_H 36 #include <errno.h> 37 #endif 38 #ifdef HAVE_UNISTD_H 39 #include <unistd.h> /* for write() and STDERR_FILENO */ 40 #endif 41 #include "selinux.h" 42 43 static BusContext *context; 44 45 #ifdef DBUS_UNIX 46 47 static int reload_pipe[2]; 48 #define RELOAD_READ_END 0 49 #define RELOAD_WRITE_END 1 50 51 static void close_reload_pipe (DBusWatch **); 52 53 typedef enum 54 { 55 ACTION_RELOAD = 'r', 56 ACTION_QUIT = 'q' 57 } SignalAction; 58 59 static void 60 signal_handler (int sig) 61 { 62 switch (sig) 63 { 64 #ifdef DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX 65 case SIGIO: 66 /* explicit fall-through */ 67 #endif /* DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX */ 68 #ifdef SIGHUP 69 case SIGHUP: 70 { 71 DBusString str; 72 char action[2] = { ACTION_RELOAD, '\0' }; 73 74 _dbus_string_init_const (&str, action); 75 if ((reload_pipe[RELOAD_WRITE_END] > 0) && 76 !_dbus_write_socket (reload_pipe[RELOAD_WRITE_END], &str, 0, 1)) 77 { 78 /* If we receive SIGHUP often enough to fill the pipe buffer (4096 79 * times on old Linux, 65536 on modern Linux) before it can be 80 * drained, let's just warn and ignore. The configuration will be 81 * reloaded while draining the pipe buffer, which is what we 82 * wanted. It's harmless that it will be reloaded fewer times than 83 * we asked for, since the reload is delayed anyway, so new changes 84 * will be picked up. 85 * 86 * We use write() because _dbus_warn uses vfprintf, which isn't 87 * async-signal-safe. 88 * 89 * This is necessarily Unix-specific, but so are POSIX signals, 90 * so... */ 91 static const char message[] = 92 "Unable to write to reload pipe - buffer full?\n"; 93 94 write (STDERR_FILENO, message, strlen (message)); 95 } 96 } 97 break; 98 #endif 99 100 case SIGTERM: 101 { 102 DBusString str; 103 char action[2] = { ACTION_QUIT, '\0' }; 104 _dbus_string_init_const (&str, action); 105 if ((reload_pipe[RELOAD_WRITE_END] < 0) || 106 !_dbus_write_socket (reload_pipe[RELOAD_WRITE_END], &str, 0, 1)) 107 { 108 /* If we can't write to the socket, dying seems a more 109 * important response to SIGTERM than cleaning up sockets, 110 * so we exit. We'd use exit(), but that's not async-signal-safe, 111 * so we'll have to resort to _exit(). */ 112 static const char message[] = 113 "Unable to write termination signal to pipe - buffer full?\n" 114 "Will exit instead.\n"; 115 116 write (STDERR_FILENO, message, strlen (message)); 117 _exit (1); 118 } 119 } 120 break; 121 } 122 } 123 #endif /* DBUS_UNIX */ 124 125 static void 126 usage (void) 127 { 128 fprintf (stderr, DBUS_DAEMON_NAME " [--version] [--session] [--system] [--config-file=FILE] [--print-address[=DESCRIPTOR]] [--print-pid[=DESCRIPTOR]] [--fork] [--nofork] [--introspect] [--address=ADDRESS] [--systemd-activation] [--nopidfile]\n"); 129 exit (1); 130 } 131 132 static void 133 version (void) 134 { 135 printf ("D-Bus Message Bus Daemon %s\n" 136 "Copyright (C) 2002, 2003 Red Hat, Inc., CodeFactory AB, and others\n" 137 "This is free software; see the source for copying conditions.\n" 138 "There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n", 139 DBUS_VERSION_STRING); 140 exit (0); 141 } 142 143 static void 144 introspect (void) 145 { 146 DBusString xml; 147 const char *v_STRING; 148 149 if (!_dbus_string_init (&xml)) 150 goto oom; 151 152 if (!bus_driver_generate_introspect_string (&xml)) 153 { 154 _dbus_string_free (&xml); 155 goto oom; 156 } 157 158 v_STRING = _dbus_string_get_const_data (&xml); 159 printf ("%s\n", v_STRING); 160 161 exit (0); 162 163 oom: 164 _dbus_warn ("Can not introspect - Out of memory\n"); 165 exit (1); 166 } 167 168 static void 169 check_two_config_files (const DBusString *config_file, 170 const char *extra_arg) 171 { 172 if (_dbus_string_get_length (config_file) > 0) 173 { 174 fprintf (stderr, "--%s specified but configuration file %s already requested\n", 175 extra_arg, _dbus_string_get_const_data (config_file)); 176 exit (1); 177 } 178 } 179 180 static void 181 check_two_addresses (const DBusString *address, 182 const char *extra_arg) 183 { 184 if (_dbus_string_get_length (address) > 0) 185 { 186 fprintf (stderr, "--%s specified but address %s already requested\n", 187 extra_arg, _dbus_string_get_const_data (address)); 188 exit (1); 189 } 190 } 191 192 static void 193 check_two_addr_descriptors (const DBusString *addr_fd, 194 const char *extra_arg) 195 { 196 if (_dbus_string_get_length (addr_fd) > 0) 197 { 198 fprintf (stderr, "--%s specified but printing address to %s already requested\n", 199 extra_arg, _dbus_string_get_const_data (addr_fd)); 200 exit (1); 201 } 202 } 203 204 static void 205 check_two_pid_descriptors (const DBusString *pid_fd, 206 const char *extra_arg) 207 { 208 if (_dbus_string_get_length (pid_fd) > 0) 209 { 210 fprintf (stderr, "--%s specified but printing pid to %s already requested\n", 211 extra_arg, _dbus_string_get_const_data (pid_fd)); 212 exit (1); 213 } 214 } 215 216 #ifdef DBUS_UNIX 217 static dbus_bool_t 218 handle_reload_watch (DBusWatch *watch, 219 unsigned int flags, 220 void *data) 221 { 222 DBusError error; 223 DBusString str; 224 char *action_str; 225 char action = '\0'; 226 227 while (!_dbus_string_init (&str)) 228 _dbus_wait_for_memory (); 229 230 if ((reload_pipe[RELOAD_READ_END] > 0) && 231 _dbus_read_socket (reload_pipe[RELOAD_READ_END], &str, 1) != 1) 232 { 233 _dbus_warn ("Couldn't read from reload pipe.\n"); 234 close_reload_pipe (&watch); 235 return TRUE; 236 } 237 238 action_str = _dbus_string_get_data (&str); 239 if (action_str != NULL) 240 { 241 action = action_str[0]; 242 } 243 _dbus_string_free (&str); 244 245 /* this can only fail if we don't understand the config file 246 * or OOM. Either way we should just stick with the currently 247 * loaded config. 248 */ 249 dbus_error_init (&error); 250 251 switch (action) 252 { 253 case ACTION_RELOAD: 254 if (! bus_context_reload_config (context, &error)) 255 { 256 _DBUS_ASSERT_ERROR_IS_SET (&error); 257 _dbus_assert (dbus_error_has_name (&error, DBUS_ERROR_FAILED) || 258 dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY)); 259 _dbus_warn ("Unable to reload configuration: %s\n", 260 error.message); 261 dbus_error_free (&error); 262 } 263 break; 264 265 case ACTION_QUIT: 266 { 267 DBusLoop *loop; 268 /* 269 * On OSs without abstract sockets, we want to quit 270 * gracefully rather than being killed by SIGTERM, 271 * so that DBusServer gets a chance to clean up the 272 * sockets from the filesystem. fd.o #38656 273 */ 274 loop = bus_context_get_loop (context); 275 if (loop != NULL) 276 { 277 _dbus_loop_quit (loop); 278 } 279 } 280 break; 281 282 default: 283 break; 284 } 285 286 return TRUE; 287 } 288 289 static void 290 setup_reload_pipe (DBusLoop *loop) 291 { 292 DBusError error; 293 DBusWatch *watch; 294 295 dbus_error_init (&error); 296 297 if (!_dbus_full_duplex_pipe (&reload_pipe[0], &reload_pipe[1], 298 TRUE, &error)) 299 { 300 _dbus_warn ("Unable to create reload pipe: %s\n", 301 error.message); 302 dbus_error_free (&error); 303 exit (1); 304 } 305 306 watch = _dbus_watch_new (reload_pipe[RELOAD_READ_END], 307 DBUS_WATCH_READABLE, TRUE, 308 handle_reload_watch, NULL, NULL); 309 310 if (watch == NULL) 311 { 312 _dbus_warn ("Unable to create reload watch: %s\n", 313 error.message); 314 dbus_error_free (&error); 315 exit (1); 316 } 317 318 if (!_dbus_loop_add_watch (loop, watch)) 319 { 320 _dbus_warn ("Unable to add reload watch to main loop: %s\n", 321 error.message); 322 dbus_error_free (&error); 323 exit (1); 324 } 325 326 } 327 328 static void 329 close_reload_pipe (DBusWatch **watch) 330 { 331 _dbus_loop_remove_watch (bus_context_get_loop (context), *watch); 332 _dbus_watch_invalidate (*watch); 333 _dbus_watch_unref (*watch); 334 *watch = NULL; 335 336 _dbus_close_socket (reload_pipe[RELOAD_READ_END], NULL); 337 reload_pipe[RELOAD_READ_END] = -1; 338 339 _dbus_close_socket (reload_pipe[RELOAD_WRITE_END], NULL); 340 reload_pipe[RELOAD_WRITE_END] = -1; 341 } 342 #endif /* DBUS_UNIX */ 343 344 int 345 main (int argc, char **argv) 346 { 347 DBusError error; 348 DBusString config_file; 349 DBusString address; 350 DBusString addr_fd; 351 DBusString pid_fd; 352 const char *prev_arg; 353 DBusPipe print_addr_pipe; 354 DBusPipe print_pid_pipe; 355 int i; 356 dbus_bool_t print_address; 357 dbus_bool_t print_pid; 358 BusContextFlags flags; 359 360 if (!_dbus_string_init (&config_file)) 361 return 1; 362 363 if (!_dbus_string_init (&address)) 364 return 1; 365 366 if (!_dbus_string_init (&addr_fd)) 367 return 1; 368 369 if (!_dbus_string_init (&pid_fd)) 370 return 1; 371 372 print_address = FALSE; 373 print_pid = FALSE; 374 375 flags = BUS_CONTEXT_FLAG_WRITE_PID_FILE; 376 377 prev_arg = NULL; 378 i = 1; 379 while (i < argc) 380 { 381 const char *arg = argv[i]; 382 383 if (strcmp (arg, "--help") == 0 || 384 strcmp (arg, "-h") == 0 || 385 strcmp (arg, "-?") == 0) 386 { 387 usage (); 388 } 389 else if (strcmp (arg, "--version") == 0) 390 { 391 version (); 392 } 393 else if (strcmp (arg, "--introspect") == 0) 394 { 395 introspect (); 396 } 397 else if (strcmp (arg, "--nofork") == 0) 398 { 399 flags &= ~BUS_CONTEXT_FLAG_FORK_ALWAYS; 400 flags |= BUS_CONTEXT_FLAG_FORK_NEVER; 401 } 402 else if (strcmp (arg, "--fork") == 0) 403 { 404 flags &= ~BUS_CONTEXT_FLAG_FORK_NEVER; 405 flags |= BUS_CONTEXT_FLAG_FORK_ALWAYS; 406 } 407 else if (strcmp (arg, "--nopidfile") == 0) 408 { 409 flags &= ~BUS_CONTEXT_FLAG_WRITE_PID_FILE; 410 } 411 else if (strcmp (arg, "--systemd-activation") == 0) 412 { 413 flags |= BUS_CONTEXT_FLAG_SYSTEMD_ACTIVATION; 414 } 415 else if (strcmp (arg, "--system") == 0) 416 { 417 check_two_config_files (&config_file, "system"); 418 419 if (!_dbus_append_system_config_file (&config_file)) 420 exit (1); 421 } 422 else if (strcmp (arg, "--session") == 0) 423 { 424 check_two_config_files (&config_file, "session"); 425 426 if (!_dbus_append_session_config_file (&config_file)) 427 exit (1); 428 } 429 else if (strstr (arg, "--config-file=") == arg) 430 { 431 const char *file; 432 433 check_two_config_files (&config_file, "config-file"); 434 435 file = strchr (arg, '='); 436 ++file; 437 438 if (!_dbus_string_append (&config_file, file)) 439 exit (1); 440 } 441 else if (prev_arg && 442 strcmp (prev_arg, "--config-file") == 0) 443 { 444 check_two_config_files (&config_file, "config-file"); 445 446 if (!_dbus_string_append (&config_file, arg)) 447 exit (1); 448 } 449 else if (strcmp (arg, "--config-file") == 0) 450 { 451 /* wait for next arg */ 452 } 453 else if (strstr (arg, "--address=") == arg) 454 { 455 const char *file; 456 457 check_two_addresses (&address, "address"); 458 459 file = strchr (arg, '='); 460 ++file; 461 462 if (!_dbus_string_append (&address, file)) 463 exit (1); 464 } 465 else if (prev_arg && 466 strcmp (prev_arg, "--address") == 0) 467 { 468 check_two_addresses (&address, "address"); 469 470 if (!_dbus_string_append (&address, arg)) 471 exit (1); 472 } 473 else if (strcmp (arg, "--address") == 0) 474 { 475 /* wait for next arg */ 476 } 477 else if (strstr (arg, "--print-address=") == arg) 478 { 479 const char *desc; 480 481 check_two_addr_descriptors (&addr_fd, "print-address"); 482 483 desc = strchr (arg, '='); 484 ++desc; 485 486 if (!_dbus_string_append (&addr_fd, desc)) 487 exit (1); 488 489 print_address = TRUE; 490 } 491 else if (prev_arg && 492 strcmp (prev_arg, "--print-address") == 0) 493 { 494 check_two_addr_descriptors (&addr_fd, "print-address"); 495 496 if (!_dbus_string_append (&addr_fd, arg)) 497 exit (1); 498 499 print_address = TRUE; 500 } 501 else if (strcmp (arg, "--print-address") == 0) 502 { 503 print_address = TRUE; /* and we'll get the next arg if appropriate */ 504 } 505 else if (strstr (arg, "--print-pid=") == arg) 506 { 507 const char *desc; 508 509 check_two_pid_descriptors (&pid_fd, "print-pid"); 510 511 desc = strchr (arg, '='); 512 ++desc; 513 514 if (!_dbus_string_append (&pid_fd, desc)) 515 exit (1); 516 517 print_pid = TRUE; 518 } 519 else if (prev_arg && 520 strcmp (prev_arg, "--print-pid") == 0) 521 { 522 check_two_pid_descriptors (&pid_fd, "print-pid"); 523 524 if (!_dbus_string_append (&pid_fd, arg)) 525 exit (1); 526 527 print_pid = TRUE; 528 } 529 else if (strcmp (arg, "--print-pid") == 0) 530 { 531 print_pid = TRUE; /* and we'll get the next arg if appropriate */ 532 } 533 else 534 { 535 usage (); 536 } 537 538 prev_arg = arg; 539 540 ++i; 541 } 542 543 if (_dbus_string_get_length (&config_file) == 0) 544 { 545 fprintf (stderr, "No configuration file specified.\n"); 546 usage (); 547 } 548 549 _dbus_pipe_invalidate (&print_addr_pipe); 550 if (print_address) 551 { 552 _dbus_pipe_init_stdout (&print_addr_pipe); 553 if (_dbus_string_get_length (&addr_fd) > 0) 554 { 555 long val; 556 int end; 557 if (!_dbus_string_parse_int (&addr_fd, 0, &val, &end) || 558 end != _dbus_string_get_length (&addr_fd) || 559 val < 0 || val > _DBUS_INT_MAX) 560 { 561 fprintf (stderr, "Invalid file descriptor: \"%s\"\n", 562 _dbus_string_get_const_data (&addr_fd)); 563 exit (1); 564 } 565 566 _dbus_pipe_init (&print_addr_pipe, val); 567 } 568 } 569 _dbus_string_free (&addr_fd); 570 571 _dbus_pipe_invalidate (&print_pid_pipe); 572 if (print_pid) 573 { 574 _dbus_pipe_init_stdout (&print_pid_pipe); 575 if (_dbus_string_get_length (&pid_fd) > 0) 576 { 577 long val; 578 int end; 579 if (!_dbus_string_parse_int (&pid_fd, 0, &val, &end) || 580 end != _dbus_string_get_length (&pid_fd) || 581 val < 0 || val > _DBUS_INT_MAX) 582 { 583 fprintf (stderr, "Invalid file descriptor: \"%s\"\n", 584 _dbus_string_get_const_data (&pid_fd)); 585 exit (1); 586 } 587 588 _dbus_pipe_init (&print_pid_pipe, val); 589 } 590 } 591 _dbus_string_free (&pid_fd); 592 593 if (!bus_selinux_pre_init ()) 594 { 595 _dbus_warn ("SELinux pre-initialization failed\n"); 596 exit (1); 597 } 598 599 dbus_error_init (&error); 600 context = bus_context_new (&config_file, flags, 601 &print_addr_pipe, &print_pid_pipe, 602 _dbus_string_get_length(&address) > 0 ? &address : NULL, 603 &error); 604 _dbus_string_free (&config_file); 605 if (context == NULL) 606 { 607 _dbus_warn ("Failed to start message bus: %s\n", 608 error.message); 609 dbus_error_free (&error); 610 exit (1); 611 } 612 613 /* bus_context_new() closes the print_addr_pipe and 614 * print_pid_pipe 615 */ 616 617 #ifdef DBUS_UNIX 618 setup_reload_pipe (bus_context_get_loop (context)); 619 620 /* POSIX signals are Unix-specific, and _dbus_set_signal_handler is 621 * unimplemented (and probably unimplementable) on Windows, so there's 622 * no point in trying to make the handler portable to non-Unix. */ 623 624 _dbus_set_signal_handler (SIGTERM, signal_handler); 625 #ifdef SIGHUP 626 _dbus_set_signal_handler (SIGHUP, signal_handler); 627 #endif 628 #ifdef DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX 629 _dbus_set_signal_handler (SIGIO, signal_handler); 630 #endif /* DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX */ 631 #endif /* DBUS_UNIX */ 632 633 _dbus_verbose ("We are on D-Bus...\n"); 634 _dbus_loop_run (bus_context_get_loop (context)); 635 636 bus_context_shutdown (context); 637 bus_context_unref (context); 638 bus_selinux_shutdown (); 639 640 return 0; 641 } 642
