1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <ctype.h> 18 #include <dirent.h> 19 #include <errno.h> 20 #include <fcntl.h> 21 #include <libgen.h> 22 #include <paths.h> 23 #include <signal.h> 24 #include <stdarg.h> 25 #include <stdio.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <sys/epoll.h> 29 #include <sys/mount.h> 30 #include <sys/socket.h> 31 #include <sys/stat.h> 32 #include <sys/types.h> 33 #include <sys/un.h> 34 #include <sys/wait.h> 35 #include <termios.h> 36 #include <unistd.h> 37 38 #include <mtd/mtd-user.h> 39 40 #include <selinux/selinux.h> 41 #include <selinux/label.h> 42 #include <selinux/android.h> 43 44 #include <base/file.h> 45 #include <base/stringprintf.h> 46 #include <cutils/android_reboot.h> 47 #include <cutils/fs.h> 48 #include <cutils/iosched_policy.h> 49 #include <cutils/list.h> 50 #include <cutils/sockets.h> 51 #include <private/android_filesystem_config.h> 52 53 #include <memory> 54 55 #include "devices.h" 56 #include "init.h" 57 #include "log.h" 58 #include "property_service.h" 59 #include "bootchart.h" 60 #include "signal_handler.h" 61 #include "keychords.h" 62 #include "init_parser.h" 63 #include "util.h" 64 #include "ueventd.h" 65 #include "watchdogd.h" 66 67 struct selabel_handle *sehandle; 68 struct selabel_handle *sehandle_prop; 69 70 static int property_triggers_enabled = 0; 71 72 static char qemu[32]; 73 74 static struct action *cur_action = NULL; 75 static struct command *cur_command = NULL; 76 77 static int have_console; 78 static char console_name[PROP_VALUE_MAX] = "/dev/console"; 79 static time_t process_needs_restart; 80 81 static const char *ENV[32]; 82 83 bool waiting_for_exec = false; 84 85 static int epoll_fd = -1; 86 87 void register_epoll_handler(int fd, void (*fn)()) { 88 epoll_event ev; 89 ev.events = EPOLLIN; 90 ev.data.ptr = reinterpret_cast<void*>(fn); 91 if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) { 92 ERROR("epoll_ctl failed: %s\n", strerror(errno)); 93 } 94 } 95 96 void service::NotifyStateChange(const char* new_state) { 97 if (!properties_initialized()) { 98 // If properties aren't available yet, we can't set them. 99 return; 100 } 101 102 if ((flags & SVC_EXEC) != 0) { 103 // 'exec' commands don't have properties tracking their state. 104 return; 105 } 106 107 char prop_name[PROP_NAME_MAX]; 108 if (snprintf(prop_name, sizeof(prop_name), "init.svc.%s", name) >= PROP_NAME_MAX) { 109 // If the property name would be too long, we can't set it. 110 ERROR("Property name \"init.svc.%s\" too long; not setting to %s\n", name, new_state); 111 return; 112 } 113 114 property_set(prop_name, new_state); 115 } 116 117 /* add_environment - add "key=value" to the current environment */ 118 int add_environment(const char *key, const char *val) 119 { 120 size_t n; 121 size_t key_len = strlen(key); 122 123 /* The last environment entry is reserved to terminate the list */ 124 for (n = 0; n < (ARRAY_SIZE(ENV) - 1); n++) { 125 126 /* Delete any existing entry for this key */ 127 if (ENV[n] != NULL) { 128 size_t entry_key_len = strcspn(ENV[n], "="); 129 if ((entry_key_len == key_len) && (strncmp(ENV[n], key, entry_key_len) == 0)) { 130 free((char*)ENV[n]); 131 ENV[n] = NULL; 132 } 133 } 134 135 /* Add entry if a free slot is available */ 136 if (ENV[n] == NULL) { 137 char* entry; 138 asprintf(&entry, "%s=%s", key, val); 139 ENV[n] = entry; 140 return 0; 141 } 142 } 143 144 ERROR("No env. room to store: '%s':'%s'\n", key, val); 145 146 return -1; 147 } 148 149 void zap_stdio(void) 150 { 151 int fd; 152 fd = open("/dev/null", O_RDWR); 153 dup2(fd, 0); 154 dup2(fd, 1); 155 dup2(fd, 2); 156 close(fd); 157 } 158 159 static void open_console() 160 { 161 int fd; 162 if ((fd = open(console_name, O_RDWR)) < 0) { 163 fd = open("/dev/null", O_RDWR); 164 } 165 ioctl(fd, TIOCSCTTY, 0); 166 dup2(fd, 0); 167 dup2(fd, 1); 168 dup2(fd, 2); 169 close(fd); 170 } 171 172 static void publish_socket(const char *name, int fd) 173 { 174 char key[64] = ANDROID_SOCKET_ENV_PREFIX; 175 char val[64]; 176 177 strlcpy(key + sizeof(ANDROID_SOCKET_ENV_PREFIX) - 1, 178 name, 179 sizeof(key) - sizeof(ANDROID_SOCKET_ENV_PREFIX)); 180 snprintf(val, sizeof(val), "%d", fd); 181 add_environment(key, val); 182 183 /* make sure we don't close-on-exec */ 184 fcntl(fd, F_SETFD, 0); 185 } 186 187 void service_start(struct service *svc, const char *dynamic_args) 188 { 189 // Starting a service removes it from the disabled or reset state and 190 // immediately takes it out of the restarting state if it was in there. 191 svc->flags &= (~(SVC_DISABLED|SVC_RESTARTING|SVC_RESET|SVC_RESTART|SVC_DISABLED_START)); 192 svc->time_started = 0; 193 194 // Running processes require no additional work --- if they're in the 195 // process of exiting, we've ensured that they will immediately restart 196 // on exit, unless they are ONESHOT. 197 if (svc->flags & SVC_RUNNING) { 198 return; 199 } 200 201 bool needs_console = (svc->flags & SVC_CONSOLE); 202 if (needs_console && !have_console) { 203 ERROR("service '%s' requires console\n", svc->name); 204 svc->flags |= SVC_DISABLED; 205 return; 206 } 207 208 struct stat s; 209 if (stat(svc->args[0], &s) != 0) { 210 ERROR("cannot find '%s', disabling '%s'\n", svc->args[0], svc->name); 211 svc->flags |= SVC_DISABLED; 212 return; 213 } 214 215 if ((!(svc->flags & SVC_ONESHOT)) && dynamic_args) { 216 ERROR("service '%s' must be one-shot to use dynamic args, disabling\n", 217 svc->args[0]); 218 svc->flags |= SVC_DISABLED; 219 return; 220 } 221 222 char* scon = NULL; 223 if (is_selinux_enabled() > 0) { 224 if (svc->seclabel) { 225 scon = strdup(svc->seclabel); 226 if (!scon) { 227 ERROR("Out of memory while starting '%s'\n", svc->name); 228 return; 229 } 230 } else { 231 char *mycon = NULL, *fcon = NULL; 232 233 INFO("computing context for service '%s'\n", svc->args[0]); 234 int rc = getcon(&mycon); 235 if (rc < 0) { 236 ERROR("could not get context while starting '%s'\n", svc->name); 237 return; 238 } 239 240 rc = getfilecon(svc->args[0], &fcon); 241 if (rc < 0) { 242 ERROR("could not get context while starting '%s'\n", svc->name); 243 freecon(mycon); 244 return; 245 } 246 247 rc = security_compute_create(mycon, fcon, string_to_security_class("process"), &scon); 248 if (rc == 0 && !strcmp(scon, mycon)) { 249 ERROR("Warning! Service %s needs a SELinux domain defined; please fix!\n", svc->name); 250 } 251 freecon(mycon); 252 freecon(fcon); 253 if (rc < 0) { 254 ERROR("could not get context while starting '%s'\n", svc->name); 255 return; 256 } 257 } 258 } 259 260 NOTICE("Starting service '%s'...\n", svc->name); 261 262 pid_t pid = fork(); 263 if (pid == 0) { 264 struct socketinfo *si; 265 struct svcenvinfo *ei; 266 char tmp[32]; 267 int fd, sz; 268 269 umask(077); 270 if (properties_initialized()) { 271 get_property_workspace(&fd, &sz); 272 snprintf(tmp, sizeof(tmp), "%d,%d", dup(fd), sz); 273 add_environment("ANDROID_PROPERTY_WORKSPACE", tmp); 274 } 275 276 for (ei = svc->envvars; ei; ei = ei->next) 277 add_environment(ei->name, ei->value); 278 279 for (si = svc->sockets; si; si = si->next) { 280 int socket_type = ( 281 !strcmp(si->type, "stream") ? SOCK_STREAM : 282 (!strcmp(si->type, "dgram") ? SOCK_DGRAM : SOCK_SEQPACKET)); 283 int s = create_socket(si->name, socket_type, 284 si->perm, si->uid, si->gid, si->socketcon ?: scon); 285 if (s >= 0) { 286 publish_socket(si->name, s); 287 } 288 } 289 290 freecon(scon); 291 scon = NULL; 292 293 if (svc->writepid_files_) { 294 std::string pid_str = android::base::StringPrintf("%d", pid); 295 for (auto& file : *svc->writepid_files_) { 296 if (!android::base::WriteStringToFile(pid_str, file)) { 297 ERROR("couldn't write %s to %s: %s\n", 298 pid_str.c_str(), file.c_str(), strerror(errno)); 299 } 300 } 301 } 302 303 if (svc->ioprio_class != IoSchedClass_NONE) { 304 if (android_set_ioprio(getpid(), svc->ioprio_class, svc->ioprio_pri)) { 305 ERROR("Failed to set pid %d ioprio = %d,%d: %s\n", 306 getpid(), svc->ioprio_class, svc->ioprio_pri, strerror(errno)); 307 } 308 } 309 310 if (needs_console) { 311 setsid(); 312 open_console(); 313 } else { 314 zap_stdio(); 315 } 316 317 if (false) { 318 for (size_t n = 0; svc->args[n]; n++) { 319 INFO("args[%zu] = '%s'\n", n, svc->args[n]); 320 } 321 for (size_t n = 0; ENV[n]; n++) { 322 INFO("env[%zu] = '%s'\n", n, ENV[n]); 323 } 324 } 325 326 setpgid(0, getpid()); 327 328 // As requested, set our gid, supplemental gids, and uid. 329 if (svc->gid) { 330 if (setgid(svc->gid) != 0) { 331 ERROR("setgid failed: %s\n", strerror(errno)); 332 _exit(127); 333 } 334 } 335 if (svc->nr_supp_gids) { 336 if (setgroups(svc->nr_supp_gids, svc->supp_gids) != 0) { 337 ERROR("setgroups failed: %s\n", strerror(errno)); 338 _exit(127); 339 } 340 } 341 if (svc->uid) { 342 if (setuid(svc->uid) != 0) { 343 ERROR("setuid failed: %s\n", strerror(errno)); 344 _exit(127); 345 } 346 } 347 if (svc->seclabel) { 348 if (is_selinux_enabled() > 0 && setexeccon(svc->seclabel) < 0) { 349 ERROR("cannot setexeccon('%s'): %s\n", svc->seclabel, strerror(errno)); 350 _exit(127); 351 } 352 } 353 354 if (!dynamic_args) { 355 if (execve(svc->args[0], (char**) svc->args, (char**) ENV) < 0) { 356 ERROR("cannot execve('%s'): %s\n", svc->args[0], strerror(errno)); 357 } 358 } else { 359 char *arg_ptrs[INIT_PARSER_MAXARGS+1]; 360 int arg_idx = svc->nargs; 361 char *tmp = strdup(dynamic_args); 362 char *next = tmp; 363 char *bword; 364 365 /* Copy the static arguments */ 366 memcpy(arg_ptrs, svc->args, (svc->nargs * sizeof(char *))); 367 368 while((bword = strsep(&next, " "))) { 369 arg_ptrs[arg_idx++] = bword; 370 if (arg_idx == INIT_PARSER_MAXARGS) 371 break; 372 } 373 arg_ptrs[arg_idx] = NULL; 374 execve(svc->args[0], (char**) arg_ptrs, (char**) ENV); 375 } 376 _exit(127); 377 } 378 379 freecon(scon); 380 381 if (pid < 0) { 382 ERROR("failed to start '%s'\n", svc->name); 383 svc->pid = 0; 384 return; 385 } 386 387 svc->time_started = gettime(); 388 svc->pid = pid; 389 svc->flags |= SVC_RUNNING; 390 391 if ((svc->flags & SVC_EXEC) != 0) { 392 INFO("SVC_EXEC pid %d (uid %d gid %d+%zu context %s) started; waiting...\n", 393 svc->pid, svc->uid, svc->gid, svc->nr_supp_gids, 394 svc->seclabel ? : "default"); 395 waiting_for_exec = true; 396 } 397 398 svc->NotifyStateChange("running"); 399 } 400 401 /* The how field should be either SVC_DISABLED, SVC_RESET, or SVC_RESTART */ 402 static void service_stop_or_reset(struct service *svc, int how) 403 { 404 /* The service is still SVC_RUNNING until its process exits, but if it has 405 * already exited it shoudn't attempt a restart yet. */ 406 svc->flags &= ~(SVC_RESTARTING | SVC_DISABLED_START); 407 408 if ((how != SVC_DISABLED) && (how != SVC_RESET) && (how != SVC_RESTART)) { 409 /* Hrm, an illegal flag. Default to SVC_DISABLED */ 410 how = SVC_DISABLED; 411 } 412 /* if the service has not yet started, prevent 413 * it from auto-starting with its class 414 */ 415 if (how == SVC_RESET) { 416 svc->flags |= (svc->flags & SVC_RC_DISABLED) ? SVC_DISABLED : SVC_RESET; 417 } else { 418 svc->flags |= how; 419 } 420 421 if (svc->pid) { 422 NOTICE("Service '%s' is being killed...\n", svc->name); 423 kill(-svc->pid, SIGKILL); 424 svc->NotifyStateChange("stopping"); 425 } else { 426 svc->NotifyStateChange("stopped"); 427 } 428 } 429 430 void service_reset(struct service *svc) 431 { 432 service_stop_or_reset(svc, SVC_RESET); 433 } 434 435 void service_stop(struct service *svc) 436 { 437 service_stop_or_reset(svc, SVC_DISABLED); 438 } 439 440 void service_restart(struct service *svc) 441 { 442 if (svc->flags & SVC_RUNNING) { 443 /* Stop, wait, then start the service. */ 444 service_stop_or_reset(svc, SVC_RESTART); 445 } else if (!(svc->flags & SVC_RESTARTING)) { 446 /* Just start the service since it's not running. */ 447 service_start(svc, NULL); 448 } /* else: Service is restarting anyways. */ 449 } 450 451 void property_changed(const char *name, const char *value) 452 { 453 if (property_triggers_enabled) 454 queue_property_triggers(name, value); 455 } 456 457 static void restart_service_if_needed(struct service *svc) 458 { 459 time_t next_start_time = svc->time_started + 5; 460 461 if (next_start_time <= gettime()) { 462 svc->flags &= (~SVC_RESTARTING); 463 service_start(svc, NULL); 464 return; 465 } 466 467 if ((next_start_time < process_needs_restart) || 468 (process_needs_restart == 0)) { 469 process_needs_restart = next_start_time; 470 } 471 } 472 473 static void restart_processes() 474 { 475 process_needs_restart = 0; 476 service_for_each_flags(SVC_RESTARTING, 477 restart_service_if_needed); 478 } 479 480 static void msg_start(const char *name) 481 { 482 struct service *svc = NULL; 483 char *tmp = NULL; 484 char *args = NULL; 485 486 if (!strchr(name, ':')) 487 svc = service_find_by_name(name); 488 else { 489 tmp = strdup(name); 490 if (tmp) { 491 args = strchr(tmp, ':'); 492 *args = '\0'; 493 args++; 494 495 svc = service_find_by_name(tmp); 496 } 497 } 498 499 if (svc) { 500 service_start(svc, args); 501 } else { 502 ERROR("no such service '%s'\n", name); 503 } 504 if (tmp) 505 free(tmp); 506 } 507 508 static void msg_stop(const char *name) 509 { 510 struct service *svc = service_find_by_name(name); 511 512 if (svc) { 513 service_stop(svc); 514 } else { 515 ERROR("no such service '%s'\n", name); 516 } 517 } 518 519 static void msg_restart(const char *name) 520 { 521 struct service *svc = service_find_by_name(name); 522 523 if (svc) { 524 service_restart(svc); 525 } else { 526 ERROR("no such service '%s'\n", name); 527 } 528 } 529 530 void handle_control_message(const char *msg, const char *arg) 531 { 532 if (!strcmp(msg,"start")) { 533 msg_start(arg); 534 } else if (!strcmp(msg,"stop")) { 535 msg_stop(arg); 536 } else if (!strcmp(msg,"restart")) { 537 msg_restart(arg); 538 } else { 539 ERROR("unknown control msg '%s'\n", msg); 540 } 541 } 542 543 static struct command *get_first_command(struct action *act) 544 { 545 struct listnode *node; 546 node = list_head(&act->commands); 547 if (!node || list_empty(&act->commands)) 548 return NULL; 549 550 return node_to_item(node, struct command, clist); 551 } 552 553 static struct command *get_next_command(struct action *act, struct command *cmd) 554 { 555 struct listnode *node; 556 node = cmd->clist.next; 557 if (!node) 558 return NULL; 559 if (node == &act->commands) 560 return NULL; 561 562 return node_to_item(node, struct command, clist); 563 } 564 565 static int is_last_command(struct action *act, struct command *cmd) 566 { 567 return (list_tail(&act->commands) == &cmd->clist); 568 } 569 570 571 void build_triggers_string(char *name_str, int length, struct action *cur_action) { 572 struct listnode *node; 573 struct trigger *cur_trigger; 574 575 list_for_each(node, &cur_action->triggers) { 576 cur_trigger = node_to_item(node, struct trigger, nlist); 577 if (node != cur_action->triggers.next) { 578 strlcat(name_str, " " , length); 579 } 580 strlcat(name_str, cur_trigger->name , length); 581 } 582 } 583 584 void execute_one_command() { 585 Timer t; 586 587 char cmd_str[256] = ""; 588 char name_str[256] = ""; 589 590 if (!cur_action || !cur_command || is_last_command(cur_action, cur_command)) { 591 cur_action = action_remove_queue_head(); 592 cur_command = NULL; 593 if (!cur_action) { 594 return; 595 } 596 597 build_triggers_string(name_str, sizeof(name_str), cur_action); 598 599 INFO("processing action %p (%s)\n", cur_action, name_str); 600 cur_command = get_first_command(cur_action); 601 } else { 602 cur_command = get_next_command(cur_action, cur_command); 603 } 604 605 if (!cur_command) { 606 return; 607 } 608 609 int result = cur_command->func(cur_command->nargs, cur_command->args); 610 if (klog_get_level() >= KLOG_INFO_LEVEL) { 611 for (int i = 0; i < cur_command->nargs; i++) { 612 strlcat(cmd_str, cur_command->args[i], sizeof(cmd_str)); 613 if (i < cur_command->nargs - 1) { 614 strlcat(cmd_str, " ", sizeof(cmd_str)); 615 } 616 } 617 char source[256]; 618 if (cur_command->filename) { 619 snprintf(source, sizeof(source), " (%s:%d)", cur_command->filename, cur_command->line); 620 } else { 621 *source = '\0'; 622 } 623 INFO("Command '%s' action=%s%s returned %d took %.2fs\n", 624 cmd_str, cur_action ? name_str : "", source, result, t.duration()); 625 } 626 } 627 628 static int wait_for_coldboot_done_action(int nargs, char **args) { 629 Timer t; 630 631 NOTICE("Waiting for %s...\n", COLDBOOT_DONE); 632 // Any longer than 1s is an unreasonable length of time to delay booting. 633 // If you're hitting this timeout, check that you didn't make your 634 // sepolicy regular expressions too expensive (http://b/19899875). 635 if (wait_for_file(COLDBOOT_DONE, 1)) { 636 ERROR("Timed out waiting for %s\n", COLDBOOT_DONE); 637 } 638 639 NOTICE("Waiting for %s took %.2fs.\n", COLDBOOT_DONE, t.duration()); 640 return 0; 641 } 642 643 /* 644 * Writes 512 bytes of output from Hardware RNG (/dev/hw_random, backed 645 * by Linux kernel's hw_random framework) into Linux RNG's via /dev/urandom. 646 * Does nothing if Hardware RNG is not present. 647 * 648 * Since we don't yet trust the quality of Hardware RNG, these bytes are not 649 * mixed into the primary pool of Linux RNG and the entropy estimate is left 650 * unmodified. 651 * 652 * If the HW RNG device /dev/hw_random is present, we require that at least 653 * 512 bytes read from it are written into Linux RNG. QA is expected to catch 654 * devices/configurations where these I/O operations are blocking for a long 655 * time. We do not reboot or halt on failures, as this is a best-effort 656 * attempt. 657 */ 658 static int mix_hwrng_into_linux_rng_action(int nargs, char **args) 659 { 660 int result = -1; 661 int hwrandom_fd = -1; 662 int urandom_fd = -1; 663 char buf[512]; 664 ssize_t chunk_size; 665 size_t total_bytes_written = 0; 666 667 hwrandom_fd = TEMP_FAILURE_RETRY( 668 open("/dev/hw_random", O_RDONLY | O_NOFOLLOW | O_CLOEXEC)); 669 if (hwrandom_fd == -1) { 670 if (errno == ENOENT) { 671 ERROR("/dev/hw_random not found\n"); 672 /* It's not an error to not have a Hardware RNG. */ 673 result = 0; 674 } else { 675 ERROR("Failed to open /dev/hw_random: %s\n", strerror(errno)); 676 } 677 goto ret; 678 } 679 680 urandom_fd = TEMP_FAILURE_RETRY( 681 open("/dev/urandom", O_WRONLY | O_NOFOLLOW | O_CLOEXEC)); 682 if (urandom_fd == -1) { 683 ERROR("Failed to open /dev/urandom: %s\n", strerror(errno)); 684 goto ret; 685 } 686 687 while (total_bytes_written < sizeof(buf)) { 688 chunk_size = TEMP_FAILURE_RETRY( 689 read(hwrandom_fd, buf, sizeof(buf) - total_bytes_written)); 690 if (chunk_size == -1) { 691 ERROR("Failed to read from /dev/hw_random: %s\n", strerror(errno)); 692 goto ret; 693 } else if (chunk_size == 0) { 694 ERROR("Failed to read from /dev/hw_random: EOF\n"); 695 goto ret; 696 } 697 698 chunk_size = TEMP_FAILURE_RETRY(write(urandom_fd, buf, chunk_size)); 699 if (chunk_size == -1) { 700 ERROR("Failed to write to /dev/urandom: %s\n", strerror(errno)); 701 goto ret; 702 } 703 total_bytes_written += chunk_size; 704 } 705 706 INFO("Mixed %zu bytes from /dev/hw_random into /dev/urandom", 707 total_bytes_written); 708 result = 0; 709 710 ret: 711 if (hwrandom_fd != -1) { 712 close(hwrandom_fd); 713 } 714 if (urandom_fd != -1) { 715 close(urandom_fd); 716 } 717 return result; 718 } 719 720 static int keychord_init_action(int nargs, char **args) 721 { 722 keychord_init(); 723 return 0; 724 } 725 726 static int console_init_action(int nargs, char **args) 727 { 728 char console[PROP_VALUE_MAX]; 729 if (property_get("ro.boot.console", console) > 0) { 730 snprintf(console_name, sizeof(console_name), "/dev/%s", console); 731 } 732 733 int fd = open(console_name, O_RDWR | O_CLOEXEC); 734 if (fd >= 0) 735 have_console = 1; 736 close(fd); 737 738 fd = open("/dev/tty0", O_WRONLY | O_CLOEXEC); 739 if (fd >= 0) { 740 const char *msg; 741 msg = "\n" 742 "\n" 743 "\n" 744 "\n" 745 "\n" 746 "\n" 747 "\n" // console is 40 cols x 30 lines 748 "\n" 749 "\n" 750 "\n" 751 "\n" 752 "\n" 753 "\n" 754 "\n" 755 " A N D R O I D "; 756 write(fd, msg, strlen(msg)); 757 close(fd); 758 } 759 760 return 0; 761 } 762 763 static void import_kernel_nv(char *name, bool for_emulator) 764 { 765 char *value = strchr(name, '='); 766 int name_len = strlen(name); 767 768 if (value == 0) return; 769 *value++ = 0; 770 if (name_len == 0) return; 771 772 if (for_emulator) { 773 /* in the emulator, export any kernel option with the 774 * ro.kernel. prefix */ 775 char buff[PROP_NAME_MAX]; 776 int len = snprintf( buff, sizeof(buff), "ro.kernel.%s", name ); 777 778 if (len < (int)sizeof(buff)) 779 property_set( buff, value ); 780 return; 781 } 782 783 if (!strcmp(name,"qemu")) { 784 strlcpy(qemu, value, sizeof(qemu)); 785 } else if (!strncmp(name, "androidboot.", 12) && name_len > 12) { 786 const char *boot_prop_name = name + 12; 787 char prop[PROP_NAME_MAX]; 788 int cnt; 789 790 cnt = snprintf(prop, sizeof(prop), "ro.boot.%s", boot_prop_name); 791 if (cnt < PROP_NAME_MAX) 792 property_set(prop, value); 793 } 794 } 795 796 static void export_kernel_boot_props() { 797 struct { 798 const char *src_prop; 799 const char *dst_prop; 800 const char *default_value; 801 } prop_map[] = { 802 { "ro.boot.serialno", "ro.serialno", "", }, 803 { "ro.boot.mode", "ro.bootmode", "unknown", }, 804 { "ro.boot.baseband", "ro.baseband", "unknown", }, 805 { "ro.boot.bootloader", "ro.bootloader", "unknown", }, 806 { "ro.boot.hardware", "ro.hardware", "unknown", }, 807 { "ro.boot.revision", "ro.revision", "0", }, 808 }; 809 for (size_t i = 0; i < ARRAY_SIZE(prop_map); i++) { 810 char value[PROP_VALUE_MAX]; 811 int rc = property_get(prop_map[i].src_prop, value); 812 property_set(prop_map[i].dst_prop, (rc > 0) ? value : prop_map[i].default_value); 813 } 814 } 815 816 static void process_kernel_dt(void) 817 { 818 static const char android_dir[] = "/proc/device-tree/firmware/android"; 819 820 std::string file_name = android::base::StringPrintf("%s/compatible", android_dir); 821 822 std::string dt_file; 823 android::base::ReadFileToString(file_name, &dt_file); 824 if (!dt_file.compare("android,firmware")) { 825 ERROR("firmware/android is not compatible with 'android,firmware'\n"); 826 return; 827 } 828 829 std::unique_ptr<DIR, int(*)(DIR*)>dir(opendir(android_dir), closedir); 830 if (!dir) 831 return; 832 833 struct dirent *dp; 834 while ((dp = readdir(dir.get())) != NULL) { 835 if (dp->d_type != DT_REG || !strcmp(dp->d_name, "compatible")) 836 continue; 837 838 file_name = android::base::StringPrintf("%s/%s", android_dir, dp->d_name); 839 840 android::base::ReadFileToString(file_name, &dt_file); 841 std::replace(dt_file.begin(), dt_file.end(), ',', '.'); 842 843 std::string property_name = android::base::StringPrintf("ro.boot.%s", dp->d_name); 844 property_set(property_name.c_str(), dt_file.c_str()); 845 } 846 } 847 848 static void process_kernel_cmdline(void) 849 { 850 /* don't expose the raw commandline to nonpriv processes */ 851 chmod("/proc/cmdline", 0440); 852 853 /* first pass does the common stuff, and finds if we are in qemu. 854 * second pass is only necessary for qemu to export all kernel params 855 * as props. 856 */ 857 import_kernel_cmdline(false, import_kernel_nv); 858 if (qemu[0]) 859 import_kernel_cmdline(true, import_kernel_nv); 860 } 861 862 static int queue_property_triggers_action(int nargs, char **args) 863 { 864 queue_all_property_triggers(); 865 /* enable property triggers */ 866 property_triggers_enabled = 1; 867 return 0; 868 } 869 870 static void selinux_init_all_handles(void) 871 { 872 sehandle = selinux_android_file_context_handle(); 873 selinux_android_set_sehandle(sehandle); 874 sehandle_prop = selinux_android_prop_context_handle(); 875 } 876 877 enum selinux_enforcing_status { SELINUX_DISABLED, SELINUX_PERMISSIVE, SELINUX_ENFORCING }; 878 879 static selinux_enforcing_status selinux_status_from_cmdline() { 880 selinux_enforcing_status status = SELINUX_ENFORCING; 881 882 std::function<void(char*,bool)> fn = [&](char* name, bool in_qemu) { 883 char *value = strchr(name, '='); 884 if (value == nullptr) { return; } 885 *value++ = '\0'; 886 if (strcmp(name, "androidboot.selinux") == 0) { 887 if (strcmp(value, "disabled") == 0) { 888 status = SELINUX_DISABLED; 889 } else if (strcmp(value, "permissive") == 0) { 890 status = SELINUX_PERMISSIVE; 891 } 892 } 893 }; 894 import_kernel_cmdline(false, fn); 895 896 return status; 897 } 898 899 900 static bool selinux_is_disabled(void) 901 { 902 if (ALLOW_DISABLE_SELINUX) { 903 if (access("/sys/fs/selinux", F_OK) != 0) { 904 // SELinux is not compiled into the kernel, or has been disabled 905 // via the kernel command line "selinux=0". 906 return true; 907 } 908 return selinux_status_from_cmdline() == SELINUX_DISABLED; 909 } 910 911 return false; 912 } 913 914 static bool selinux_is_enforcing(void) 915 { 916 if (ALLOW_DISABLE_SELINUX) { 917 return selinux_status_from_cmdline() == SELINUX_ENFORCING; 918 } 919 return true; 920 } 921 922 int selinux_reload_policy(void) 923 { 924 if (selinux_is_disabled()) { 925 return -1; 926 } 927 928 INFO("SELinux: Attempting to reload policy files\n"); 929 930 if (selinux_android_reload_policy() == -1) { 931 return -1; 932 } 933 934 if (sehandle) 935 selabel_close(sehandle); 936 937 if (sehandle_prop) 938 selabel_close(sehandle_prop); 939 940 selinux_init_all_handles(); 941 return 0; 942 } 943 944 static int audit_callback(void *data, security_class_t /*cls*/, char *buf, size_t len) { 945 snprintf(buf, len, "property=%s", !data ? "NULL" : (char *)data); 946 return 0; 947 } 948 949 static void security_failure() { 950 ERROR("Security failure; rebooting into recovery mode...\n"); 951 android_reboot(ANDROID_RB_RESTART2, 0, "recovery"); 952 while (true) { pause(); } // never reached 953 } 954 955 static void selinux_initialize(bool in_kernel_domain) { 956 Timer t; 957 958 selinux_callback cb; 959 cb.func_log = selinux_klog_callback; 960 selinux_set_callback(SELINUX_CB_LOG, cb); 961 cb.func_audit = audit_callback; 962 selinux_set_callback(SELINUX_CB_AUDIT, cb); 963 964 if (selinux_is_disabled()) { 965 return; 966 } 967 968 if (in_kernel_domain) { 969 INFO("Loading SELinux policy...\n"); 970 if (selinux_android_load_policy() < 0) { 971 ERROR("failed to load policy: %s\n", strerror(errno)); 972 security_failure(); 973 } 974 975 bool is_enforcing = selinux_is_enforcing(); 976 security_setenforce(is_enforcing); 977 978 if (write_file("/sys/fs/selinux/checkreqprot", "0") == -1) { 979 security_failure(); 980 } 981 982 NOTICE("(Initializing SELinux %s took %.2fs.)\n", 983 is_enforcing ? "enforcing" : "non-enforcing", t.duration()); 984 } else { 985 selinux_init_all_handles(); 986 } 987 } 988 989 int main(int argc, char** argv) { 990 if (!strcmp(basename(argv[0]), "ueventd")) { 991 return ueventd_main(argc, argv); 992 } 993 994 if (!strcmp(basename(argv[0]), "watchdogd")) { 995 return watchdogd_main(argc, argv); 996 } 997 998 // Clear the umask. 999 umask(0); 1000 1001 add_environment("PATH", _PATH_DEFPATH); 1002 1003 bool is_first_stage = (argc == 1) || (strcmp(argv[1], "--second-stage") != 0); 1004 1005 // Get the basic filesystem setup we need put together in the initramdisk 1006 // on / and then we'll let the rc file figure out the rest. 1007 if (is_first_stage) { 1008 mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755"); 1009 mkdir("/dev/pts", 0755); 1010 mkdir("/dev/socket", 0755); 1011 mount("devpts", "/dev/pts", "devpts", 0, NULL); 1012 mount("proc", "/proc", "proc", 0, NULL); 1013 mount("sysfs", "/sys", "sysfs", 0, NULL); 1014 } 1015 1016 // We must have some place other than / to create the device nodes for 1017 // kmsg and null, otherwise we won't be able to remount / read-only 1018 // later on. Now that tmpfs is mounted on /dev, we can actually talk 1019 // to the outside world. 1020 open_devnull_stdio(); 1021 klog_init(); 1022 klog_set_level(KLOG_NOTICE_LEVEL); 1023 1024 NOTICE("init%s started!\n", is_first_stage ? "" : " second stage"); 1025 1026 if (!is_first_stage) { 1027 // Indicate that booting is in progress to background fw loaders, etc. 1028 close(open("/dev/.booting", O_WRONLY | O_CREAT | O_CLOEXEC, 0000)); 1029 1030 property_init(); 1031 1032 // If arguments are passed both on the command line and in DT, 1033 // properties set in DT always have priority over the command-line ones. 1034 process_kernel_dt(); 1035 process_kernel_cmdline(); 1036 1037 // Propogate the kernel variables to internal variables 1038 // used by init as well as the current required properties. 1039 export_kernel_boot_props(); 1040 } 1041 1042 // Set up SELinux, including loading the SELinux policy if we're in the kernel domain. 1043 selinux_initialize(is_first_stage); 1044 1045 // If we're in the kernel domain, re-exec init to transition to the init domain now 1046 // that the SELinux policy has been loaded. 1047 if (is_first_stage) { 1048 if (restorecon("/init") == -1) { 1049 ERROR("restorecon failed: %s\n", strerror(errno)); 1050 security_failure(); 1051 } 1052 char* path = argv[0]; 1053 char* args[] = { path, const_cast<char*>("--second-stage"), nullptr }; 1054 if (execv(path, args) == -1) { 1055 ERROR("execv(\"%s\") failed: %s\n", path, strerror(errno)); 1056 security_failure(); 1057 } 1058 } 1059 1060 // These directories were necessarily created before initial policy load 1061 // and therefore need their security context restored to the proper value. 1062 // This must happen before /dev is populated by ueventd. 1063 INFO("Running restorecon...\n"); 1064 restorecon("/dev"); 1065 restorecon("/dev/socket"); 1066 restorecon("/dev/__properties__"); 1067 restorecon_recursive("/sys"); 1068 1069 epoll_fd = epoll_create1(EPOLL_CLOEXEC); 1070 if (epoll_fd == -1) { 1071 ERROR("epoll_create1 failed: %s\n", strerror(errno)); 1072 exit(1); 1073 } 1074 1075 signal_handler_init(); 1076 1077 property_load_boot_defaults(); 1078 start_property_service(); 1079 1080 init_parse_config_file("/init.rc"); 1081 1082 action_for_each_trigger("early-init", action_add_queue_tail); 1083 1084 // Queue an action that waits for coldboot done so we know ueventd has set up all of /dev... 1085 queue_builtin_action(wait_for_coldboot_done_action, "wait_for_coldboot_done"); 1086 // ... so that we can start queuing up actions that require stuff from /dev. 1087 queue_builtin_action(mix_hwrng_into_linux_rng_action, "mix_hwrng_into_linux_rng"); 1088 queue_builtin_action(keychord_init_action, "keychord_init"); 1089 queue_builtin_action(console_init_action, "console_init"); 1090 1091 // Trigger all the boot actions to get us started. 1092 action_for_each_trigger("init", action_add_queue_tail); 1093 1094 // Repeat mix_hwrng_into_linux_rng in case /dev/hw_random or /dev/random 1095 // wasn't ready immediately after wait_for_coldboot_done 1096 queue_builtin_action(mix_hwrng_into_linux_rng_action, "mix_hwrng_into_linux_rng"); 1097 1098 // Don't mount filesystems or start core system services in charger mode. 1099 char bootmode[PROP_VALUE_MAX]; 1100 if (property_get("ro.bootmode", bootmode) > 0 && strcmp(bootmode, "charger") == 0) { 1101 action_for_each_trigger("charger", action_add_queue_tail); 1102 } else { 1103 action_for_each_trigger("late-init", action_add_queue_tail); 1104 } 1105 1106 // Run all property triggers based on current state of the properties. 1107 queue_builtin_action(queue_property_triggers_action, "queue_property_triggers"); 1108 1109 while (true) { 1110 if (!waiting_for_exec) { 1111 execute_one_command(); 1112 restart_processes(); 1113 } 1114 1115 int timeout = -1; 1116 if (process_needs_restart) { 1117 timeout = (process_needs_restart - gettime()) * 1000; 1118 if (timeout < 0) 1119 timeout = 0; 1120 } 1121 1122 if (!action_queue_empty() || cur_action) { 1123 timeout = 0; 1124 } 1125 1126 bootchart_sample(&timeout); 1127 1128 epoll_event ev; 1129 int nr = TEMP_FAILURE_RETRY(epoll_wait(epoll_fd, &ev, 1, timeout)); 1130 if (nr == -1) { 1131 ERROR("epoll_wait failed: %s\n", strerror(errno)); 1132 } else if (nr == 1) { 1133 ((void (*)()) ev.data.ptr)(); 1134 } 1135 } 1136 1137 return 0; 1138 } 1139