/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "init.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef RECOVERY #include #endif #include "action_parser.h" #include "boringssl_self_test.h" #include "epoll.h" #include "first_stage_mount.h" #include "import_parser.h" #include "keychords.h" #include "mount_handler.h" #include "mount_namespace.h" #include "property_service.h" #include "reboot.h" #include "reboot_utils.h" #include "security.h" #include "selinux.h" #include "sigchld_handler.h" #include "util.h" using namespace std::chrono_literals; using namespace std::string_literals; using android::base::boot_clock; using android::base::GetProperty; using android::base::ReadFileToString; using android::base::StringPrintf; using android::base::Timer; using android::base::Trim; using android::fs_mgr::AvbHandle; namespace android { namespace init { static int property_triggers_enabled = 0; static char qemu[32]; std::string default_console = "/dev/console"; static int signal_fd = -1; static std::unique_ptr waiting_for_prop(nullptr); static std::string wait_prop_name; static std::string wait_prop_value; static bool shutting_down; static std::string shutdown_command; static bool do_shutdown = false; static bool load_debug_prop = false; std::vector late_import_paths; static std::vector* subcontexts; void DumpState() { ServiceList::GetInstance().DumpState(); ActionManager::GetInstance().DumpState(); } Parser CreateParser(ActionManager& action_manager, ServiceList& service_list) { Parser parser; parser.AddSectionParser("service", std::make_unique(&service_list, subcontexts)); parser.AddSectionParser("on", std::make_unique(&action_manager, subcontexts)); parser.AddSectionParser("import", std::make_unique(&parser)); return parser; } // parser that only accepts new services Parser CreateServiceOnlyParser(ServiceList& service_list) { Parser parser; parser.AddSectionParser("service", std::make_unique(&service_list, subcontexts)); return parser; } static void LoadBootScripts(ActionManager& action_manager, ServiceList& service_list) { Parser parser = CreateParser(action_manager, service_list); std::string bootscript = GetProperty("ro.boot.init_rc", ""); if (bootscript.empty()) { parser.ParseConfig("/init.rc"); if (!parser.ParseConfig("/system/etc/init")) { late_import_paths.emplace_back("/system/etc/init"); } if (!parser.ParseConfig("/product/etc/init")) { late_import_paths.emplace_back("/product/etc/init"); } if (!parser.ParseConfig("/product_services/etc/init")) { late_import_paths.emplace_back("/product_services/etc/init"); } if (!parser.ParseConfig("/odm/etc/init")) { late_import_paths.emplace_back("/odm/etc/init"); } if (!parser.ParseConfig("/vendor/etc/init")) { late_import_paths.emplace_back("/vendor/etc/init"); } } else { parser.ParseConfig(bootscript); } } bool start_waiting_for_property(const char *name, const char *value) { if (waiting_for_prop) { return false; } if (GetProperty(name, "") != value) { // Current property value is not equal to expected value wait_prop_name = name; wait_prop_value = value; waiting_for_prop.reset(new Timer()); } else { LOG(INFO) << "start_waiting_for_property(\"" << name << "\", \"" << value << "\"): already set"; } return true; } void ResetWaitForProp() { wait_prop_name.clear(); wait_prop_value.clear(); waiting_for_prop.reset(); } void property_changed(const std::string& name, const std::string& value) { // If the property is sys.powerctl, we bypass the event queue and immediately handle it. // This is to ensure that init will always and immediately shutdown/reboot, regardless of // if there are other pending events to process or if init is waiting on an exec service or // waiting on a property. // In non-thermal-shutdown case, 'shutdown' trigger will be fired to let device specific // commands to be executed. if (name == "sys.powerctl") { // Despite the above comment, we can't call HandlePowerctlMessage() in this function, // because it modifies the contents of the action queue, which can cause the action queue // to get into a bad state if this function is called from a command being executed by the // action queue. Instead we set this flag and ensure that shutdown happens before the next // command is run in the main init loop. // TODO: once property service is removed from init, this will never happen from a builtin, // but rather from a callback from the property service socket, in which case this hack can // go away. shutdown_command = value; do_shutdown = true; } if (property_triggers_enabled) ActionManager::GetInstance().QueuePropertyChange(name, value); if (waiting_for_prop) { if (wait_prop_name == name && wait_prop_value == value) { LOG(INFO) << "Wait for property '" << wait_prop_name << "=" << wait_prop_value << "' took " << *waiting_for_prop; ResetWaitForProp(); } } } static std::optional HandleProcessActions() { std::optional next_process_action_time; for (const auto& s : ServiceList::GetInstance()) { if ((s->flags() & SVC_RUNNING) && s->timeout_period()) { auto timeout_time = s->time_started() + *s->timeout_period(); if (boot_clock::now() > timeout_time) { s->Timeout(); } else { if (!next_process_action_time || timeout_time < *next_process_action_time) { next_process_action_time = timeout_time; } } } if (!(s->flags() & SVC_RESTARTING)) continue; auto restart_time = s->time_started() + s->restart_period(); if (boot_clock::now() > restart_time) { if (auto result = s->Start(); !result) { LOG(ERROR) << "Could not restart process '" << s->name() << "': " << result.error(); } } else { if (!next_process_action_time || restart_time < *next_process_action_time) { next_process_action_time = restart_time; } } } return next_process_action_time; } static Result DoControlStart(Service* service) { return service->Start(); } static Result DoControlStop(Service* service) { service->Stop(); return Success(); } static Result DoControlRestart(Service* service) { service->Restart(); return Success(); } enum class ControlTarget { SERVICE, // function gets called for the named service INTERFACE, // action gets called for every service that holds this interface }; struct ControlMessageFunction { ControlTarget target; std::function(Service*)> action; }; static const std::map& get_control_message_map() { // clang-format off static const std::map control_message_functions = { {"sigstop_on", {ControlTarget::SERVICE, [](auto* service) { service->set_sigstop(true); return Success(); }}}, {"sigstop_off", {ControlTarget::SERVICE, [](auto* service) { service->set_sigstop(false); return Success(); }}}, {"start", {ControlTarget::SERVICE, DoControlStart}}, {"stop", {ControlTarget::SERVICE, DoControlStop}}, {"restart", {ControlTarget::SERVICE, DoControlRestart}}, {"interface_start", {ControlTarget::INTERFACE, DoControlStart}}, {"interface_stop", {ControlTarget::INTERFACE, DoControlStop}}, {"interface_restart", {ControlTarget::INTERFACE, DoControlRestart}}, }; // clang-format on return control_message_functions; } void HandleControlMessage(const std::string& msg, const std::string& name, pid_t pid) { const auto& map = get_control_message_map(); const auto it = map.find(msg); if (it == map.end()) { LOG(ERROR) << "Unknown control msg '" << msg << "'"; return; } std::string cmdline_path = StringPrintf("proc/%d/cmdline", pid); std::string process_cmdline; if (ReadFileToString(cmdline_path, &process_cmdline)) { std::replace(process_cmdline.begin(), process_cmdline.end(), '\0', ' '); process_cmdline = Trim(process_cmdline); } else { process_cmdline = "unknown process"; } LOG(INFO) << "Received control message '" << msg << "' for '" << name << "' from pid: " << pid << " (" << process_cmdline << ")"; const ControlMessageFunction& function = it->second; Service* svc = nullptr; switch (function.target) { case ControlTarget::SERVICE: svc = ServiceList::GetInstance().FindService(name); break; case ControlTarget::INTERFACE: svc = ServiceList::GetInstance().FindInterface(name); break; default: LOG(ERROR) << "Invalid function target from static map key '" << msg << "': " << static_cast::type>(function.target); return; } if (svc == nullptr) { LOG(ERROR) << "Could not find '" << name << "' for ctl." << msg; return; } if (auto result = function.action(svc); !result) { LOG(ERROR) << "Could not ctl." << msg << " for '" << name << "': " << result.error(); } } static Result wait_for_coldboot_done_action(const BuiltinArguments& args) { Timer t; LOG(VERBOSE) << "Waiting for " COLDBOOT_DONE "..."; // Historically we had a 1s timeout here because we weren't otherwise // tracking boot time, and many OEMs made their sepolicy regular // expressions too expensive (http://b/19899875). // Now we're tracking boot time, just log the time taken to a system // property. We still panic if it takes more than a minute though, // because any build that slow isn't likely to boot at all, and we'd // rather any test lab devices fail back to the bootloader. if (wait_for_file(COLDBOOT_DONE, 60s) < 0) { LOG(FATAL) << "Timed out waiting for " COLDBOOT_DONE; } property_set("ro.boottime.init.cold_boot_wait", std::to_string(t.duration().count())); return Success(); } static Result console_init_action(const BuiltinArguments& args) { std::string console = GetProperty("ro.boot.console", ""); if (!console.empty()) { default_console = "/dev/" + console; } return Success(); } static Result SetupCgroupsAction(const BuiltinArguments&) { // Have to create using make_dir function // for appropriate sepolicy to be set for it make_dir(android::base::Dirname(CGROUPS_RC_PATH), 0711); if (!CgroupSetup()) { return ErrnoError() << "Failed to setup cgroups"; } return Success(); } static void import_kernel_nv(const std::string& key, const std::string& value, bool for_emulator) { if (key.empty()) return; if (for_emulator) { // In the emulator, export any kernel option with the "ro.kernel." prefix. property_set("ro.kernel." + key, value); return; } if (key == "qemu") { strlcpy(qemu, value.c_str(), sizeof(qemu)); } else if (android::base::StartsWith(key, "androidboot.")) { property_set("ro.boot." + key.substr(12), value); } } static void export_oem_lock_status() { if (!android::base::GetBoolProperty("ro.oem_unlock_supported", false)) { return; } import_kernel_cmdline( false, [](const std::string& key, const std::string& value, bool in_qemu) { if (key == "androidboot.verifiedbootstate") { property_set("ro.boot.flash.locked", value == "orange" ? "0" : "1"); } }); } static void export_kernel_boot_props() { constexpr const char* UNSET = ""; struct { const char *src_prop; const char *dst_prop; const char *default_value; } prop_map[] = { { "ro.boot.serialno", "ro.serialno", UNSET, }, { "ro.boot.mode", "ro.bootmode", "unknown", }, { "ro.boot.baseband", "ro.baseband", "unknown", }, { "ro.boot.bootloader", "ro.bootloader", "unknown", }, { "ro.boot.hardware", "ro.hardware", "unknown", }, { "ro.boot.revision", "ro.revision", "0", }, }; for (const auto& prop : prop_map) { std::string value = GetProperty(prop.src_prop, prop.default_value); if (value != UNSET) property_set(prop.dst_prop, value); } } static void process_kernel_dt() { if (!is_android_dt_value_expected("compatible", "android,firmware")) { return; } std::unique_ptr dir(opendir(get_android_dt_dir().c_str()), closedir); if (!dir) return; std::string dt_file; struct dirent *dp; while ((dp = readdir(dir.get())) != NULL) { if (dp->d_type != DT_REG || !strcmp(dp->d_name, "compatible") || !strcmp(dp->d_name, "name")) { continue; } std::string file_name = get_android_dt_dir() + dp->d_name; android::base::ReadFileToString(file_name, &dt_file); std::replace(dt_file.begin(), dt_file.end(), ',', '.'); property_set("ro.boot."s + dp->d_name, dt_file); } } static void process_kernel_cmdline() { // The first pass does the common stuff, and finds if we are in qemu. // The second pass is only necessary for qemu to export all kernel params // as properties. import_kernel_cmdline(false, import_kernel_nv); if (qemu[0]) import_kernel_cmdline(true, import_kernel_nv); } static Result property_enable_triggers_action(const BuiltinArguments& args) { /* Enable property triggers. */ property_triggers_enabled = 1; return Success(); } static Result queue_property_triggers_action(const BuiltinArguments& args) { ActionManager::GetInstance().QueueBuiltinAction(property_enable_triggers_action, "enable_property_trigger"); ActionManager::GetInstance().QueueAllPropertyActions(); return Success(); } static Result InitBinder(const BuiltinArguments& args) { // init's use of binder is very limited. init cannot: // - have any binder threads // - receive incoming binder calls // - pass local binder services to remote processes // - use death recipients // The main supported usecases are: // - notifying other daemons (oneway calls only) // - retrieving data that is necessary to boot // Also, binder can't be used by recovery. #ifndef RECOVERY android::ProcessState::self()->setThreadPoolMaxThreadCount(0); android::ProcessState::self()->setCallRestriction( ProcessState::CallRestriction::ERROR_IF_NOT_ONEWAY); #endif return Success(); } // Set the UDC controller for the ConfigFS USB Gadgets. // Read the UDC controller in use from "/sys/class/udc". // In case of multiple UDC controllers select the first one. static void set_usb_controller() { std::unique_ptrdir(opendir("/sys/class/udc"), closedir); if (!dir) return; dirent* dp; while ((dp = readdir(dir.get())) != nullptr) { if (dp->d_name[0] == '.') continue; property_set("sys.usb.controller", dp->d_name); break; } } static void HandleSigtermSignal(const signalfd_siginfo& siginfo) { if (siginfo.ssi_pid != 0) { // Drop any userspace SIGTERM requests. LOG(DEBUG) << "Ignoring SIGTERM from pid " << siginfo.ssi_pid; return; } HandlePowerctlMessage("shutdown,container"); } static void HandleSignalFd() { signalfd_siginfo siginfo; ssize_t bytes_read = TEMP_FAILURE_RETRY(read(signal_fd, &siginfo, sizeof(siginfo))); if (bytes_read != sizeof(siginfo)) { PLOG(ERROR) << "Failed to read siginfo from signal_fd"; return; } switch (siginfo.ssi_signo) { case SIGCHLD: ReapAnyOutstandingChildren(); break; case SIGTERM: HandleSigtermSignal(siginfo); break; default: PLOG(ERROR) << "signal_fd: received unexpected signal " << siginfo.ssi_signo; break; } } static void UnblockSignals() { const struct sigaction act { .sa_handler = SIG_DFL }; sigaction(SIGCHLD, &act, nullptr); sigset_t mask; sigemptyset(&mask); sigaddset(&mask, SIGCHLD); sigaddset(&mask, SIGTERM); if (sigprocmask(SIG_UNBLOCK, &mask, nullptr) == -1) { PLOG(FATAL) << "failed to unblock signals for PID " << getpid(); } } static void InstallSignalFdHandler(Epoll* epoll) { // Applying SA_NOCLDSTOP to a defaulted SIGCHLD handler prevents the signalfd from receiving // SIGCHLD when a child process stops or continues (b/77867680#comment9). const struct sigaction act { .sa_handler = SIG_DFL, .sa_flags = SA_NOCLDSTOP }; sigaction(SIGCHLD, &act, nullptr); sigset_t mask; sigemptyset(&mask); sigaddset(&mask, SIGCHLD); if (!IsRebootCapable()) { // If init does not have the CAP_SYS_BOOT capability, it is running in a container. // In that case, receiving SIGTERM will cause the system to shut down. sigaddset(&mask, SIGTERM); } if (sigprocmask(SIG_BLOCK, &mask, nullptr) == -1) { PLOG(FATAL) << "failed to block signals"; } // Register a handler to unblock signals in the child processes. const int result = pthread_atfork(nullptr, nullptr, &UnblockSignals); if (result != 0) { LOG(FATAL) << "Failed to register a fork handler: " << strerror(result); } signal_fd = signalfd(-1, &mask, SFD_CLOEXEC); if (signal_fd == -1) { PLOG(FATAL) << "failed to create signalfd"; } if (auto result = epoll->RegisterHandler(signal_fd, HandleSignalFd); !result) { LOG(FATAL) << result.error(); } } void HandleKeychord(const std::vector& keycodes) { // Only handle keychords if adb is enabled. std::string adb_enabled = android::base::GetProperty("init.svc.adbd", ""); if (adb_enabled != "running") { LOG(WARNING) << "Not starting service for keychord " << android::base::Join(keycodes, ' ') << " because ADB is disabled"; return; } auto found = false; for (const auto& service : ServiceList::GetInstance()) { auto svc = service.get(); if (svc->keycodes() == keycodes) { found = true; LOG(INFO) << "Starting service '" << svc->name() << "' from keychord " << android::base::Join(keycodes, ' '); if (auto result = svc->Start(); !result) { LOG(ERROR) << "Could not start service '" << svc->name() << "' from keychord " << android::base::Join(keycodes, ' ') << ": " << result.error(); } } } if (!found) { LOG(ERROR) << "Service for keychord " << android::base::Join(keycodes, ' ') << " not found"; } } static void GlobalSeccomp() { import_kernel_cmdline(false, [](const std::string& key, const std::string& value, bool in_qemu) { if (key == "androidboot.seccomp" && value == "global" && !set_global_seccomp_filter()) { LOG(FATAL) << "Failed to globally enable seccomp!"; } }); } static void UmountDebugRamdisk() { if (umount("/debug_ramdisk") != 0) { LOG(ERROR) << "Failed to umount /debug_ramdisk"; } } int SecondStageMain(int argc, char** argv) { if (REBOOT_BOOTLOADER_ON_PANIC) { InstallRebootSignalHandlers(); } SetStdioToDevNull(argv); InitKernelLogging(argv); LOG(INFO) << "init second stage started!"; // Set init and its forked children's oom_adj. if (auto result = WriteFile("/proc/1/oom_score_adj", "-1000"); !result) { LOG(ERROR) << "Unable to write -1000 to /proc/1/oom_score_adj: " << result.error(); } // Enable seccomp if global boot option was passed (otherwise it is enabled in zygote). GlobalSeccomp(); // Set up a session keyring that all processes will have access to. It // will hold things like FBE encryption keys. No process should override // its session keyring. keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 1); // Indicate that booting is in progress to background fw loaders, etc. close(open("/dev/.booting", O_WRONLY | O_CREAT | O_CLOEXEC, 0000)); property_init(); // If arguments are passed both on the command line and in DT, // properties set in DT always have priority over the command-line ones. process_kernel_dt(); process_kernel_cmdline(); // Propagate the kernel variables to internal variables // used by init as well as the current required properties. export_kernel_boot_props(); // Make the time that init started available for bootstat to log. property_set("ro.boottime.init", getenv("INIT_STARTED_AT")); property_set("ro.boottime.init.selinux", getenv("INIT_SELINUX_TOOK")); // Set libavb version for Framework-only OTA match in Treble build. const char* avb_version = getenv("INIT_AVB_VERSION"); if (avb_version) property_set("ro.boot.avb_version", avb_version); // See if need to load debug props to allow adb root, when the device is unlocked. const char* force_debuggable_env = getenv("INIT_FORCE_DEBUGGABLE"); if (force_debuggable_env && AvbHandle::IsDeviceUnlocked()) { load_debug_prop = "true"s == force_debuggable_env; } // Clean up our environment. unsetenv("INIT_STARTED_AT"); unsetenv("INIT_SELINUX_TOOK"); unsetenv("INIT_AVB_VERSION"); unsetenv("INIT_FORCE_DEBUGGABLE"); // Now set up SELinux for second stage. SelinuxSetupKernelLogging(); SelabelInitialize(); SelinuxRestoreContext(); Epoll epoll; if (auto result = epoll.Open(); !result) { PLOG(FATAL) << result.error(); } InstallSignalFdHandler(&epoll); property_load_boot_defaults(load_debug_prop); UmountDebugRamdisk(); fs_mgr_vendor_overlay_mount_all(); export_oem_lock_status(); StartPropertyService(&epoll); MountHandler mount_handler(&epoll); set_usb_controller(); const BuiltinFunctionMap function_map; Action::set_function_map(&function_map); if (!SetupMountNamespaces()) { PLOG(FATAL) << "SetupMountNamespaces failed"; } subcontexts = InitializeSubcontexts(); ActionManager& am = ActionManager::GetInstance(); ServiceList& sm = ServiceList::GetInstance(); LoadBootScripts(am, sm); // Turning this on and letting the INFO logging be discarded adds 0.2s to // Nexus 9 boot time, so it's disabled by default. if (false) DumpState(); // Make the GSI status available before scripts start running. if (android::gsi::IsGsiRunning()) { property_set("ro.gsid.image_running", "1"); } else { property_set("ro.gsid.image_running", "0"); } am.QueueBuiltinAction(SetupCgroupsAction, "SetupCgroups"); am.QueueEventTrigger("early-init"); // Queue an action that waits for coldboot done so we know ueventd has set up all of /dev... am.QueueBuiltinAction(wait_for_coldboot_done_action, "wait_for_coldboot_done"); // ... so that we can start queuing up actions that require stuff from /dev. am.QueueBuiltinAction(MixHwrngIntoLinuxRngAction, "MixHwrngIntoLinuxRng"); am.QueueBuiltinAction(SetMmapRndBitsAction, "SetMmapRndBits"); am.QueueBuiltinAction(SetKptrRestrictAction, "SetKptrRestrict"); Keychords keychords; am.QueueBuiltinAction( [&epoll, &keychords](const BuiltinArguments& args) -> Result { for (const auto& svc : ServiceList::GetInstance()) { keychords.Register(svc->keycodes()); } keychords.Start(&epoll, HandleKeychord); return Success(); }, "KeychordInit"); am.QueueBuiltinAction(console_init_action, "console_init"); // Trigger all the boot actions to get us started. am.QueueEventTrigger("init"); // Starting the BoringSSL self test, for NIAP certification compliance. am.QueueBuiltinAction(StartBoringSslSelfTest, "StartBoringSslSelfTest"); // Repeat mix_hwrng_into_linux_rng in case /dev/hw_random or /dev/random // wasn't ready immediately after wait_for_coldboot_done am.QueueBuiltinAction(MixHwrngIntoLinuxRngAction, "MixHwrngIntoLinuxRng"); // Initialize binder before bringing up other system services am.QueueBuiltinAction(InitBinder, "InitBinder"); // Don't mount filesystems or start core system services in charger mode. std::string bootmode = GetProperty("ro.bootmode", ""); if (bootmode == "charger") { am.QueueEventTrigger("charger"); } else { am.QueueEventTrigger("late-init"); } // Run all property triggers based on current state of the properties. am.QueueBuiltinAction(queue_property_triggers_action, "queue_property_triggers"); while (true) { // By default, sleep until something happens. auto epoll_timeout = std::optional{}; if (do_shutdown && !shutting_down) { do_shutdown = false; if (HandlePowerctlMessage(shutdown_command)) { shutting_down = true; } } if (!(waiting_for_prop || Service::is_exec_service_running())) { am.ExecuteOneCommand(); } if (!(waiting_for_prop || Service::is_exec_service_running())) { if (!shutting_down) { auto next_process_action_time = HandleProcessActions(); // If there's a process that needs restarting, wake up in time for that. if (next_process_action_time) { epoll_timeout = std::chrono::ceil( *next_process_action_time - boot_clock::now()); if (*epoll_timeout < 0ms) epoll_timeout = 0ms; } } // If there's more work to do, wake up again immediately. if (am.HasMoreCommands()) epoll_timeout = 0ms; } if (auto result = epoll.Wait(epoll_timeout); !result) { LOG(ERROR) << result.error(); } } return 0; } } // namespace init } // namespace android