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platform_system_core/init/service.cpp
Suren Baghdasaryan 1bd1746447 init: Treat failure to create a process group as fatal 
During process startup, system creates a process group and places the
new process in it. If process group creation fails for some reason, the
new child process will stay in its parent's group. This poses danger
when the child is being frozen because the whole group is affected and
its parent is being frozen as well.
Fix this by treating group creation failure as a fatal error which would
prevent the app from starting.

Bug: 227395690
Test: fake group creation failure and confirm service failure to start
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I83261bef803751759c7fd709bf1ccd33ccad3a0b
2022-04-01 23:32:47 +00:00

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/*
* Copyright (C) 2015 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 "service.h"
#include <fcntl.h>
#include <inttypes.h>
#include <linux/securebits.h>
#include <sched.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <termios.h>
#include <unistd.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/scopeguard.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <cutils/sockets.h>
#include <processgroup/processgroup.h>
#include <selinux/selinux.h>
#include "lmkd_service.h"
#include "service_list.h"
#include "util.h"
#ifdef INIT_FULL_SOURCES
#include <ApexProperties.sysprop.h>
#include <android/api-level.h>
#include "mount_namespace.h"
#include "reboot_utils.h"
#include "selinux.h"
#else
#include "host_init_stubs.h"
#endif
using android::base::boot_clock;
using android::base::GetBoolProperty;
using android::base::GetProperty;
using android::base::Join;
using android::base::make_scope_guard;
using android::base::SetProperty;
using android::base::StartsWith;
using android::base::StringPrintf;
using android::base::WriteStringToFile;
namespace android {
namespace init {
static Result<std::string> ComputeContextFromExecutable(const std::string& service_path) {
std::string computed_context;
char* raw_con = nullptr;
char* raw_filecon = nullptr;
if (getcon(&raw_con) == -1) {
return Error() << "Could not get security context";
}
std::unique_ptr<char, decltype(&freecon)> mycon(raw_con, freecon);
if (getfilecon(service_path.c_str(), &raw_filecon) == -1) {
return Error() << "Could not get file context";
}
std::unique_ptr<char, decltype(&freecon)> filecon(raw_filecon, freecon);
char* new_con = nullptr;
int rc = security_compute_create(mycon.get(), filecon.get(),
string_to_security_class("process"), &new_con);
if (rc == 0) {
computed_context = new_con;
free(new_con);
}
if (rc == 0 && computed_context == mycon.get()) {
return Error() << "File " << service_path << "(labeled \"" << filecon.get()
<< "\") has incorrect label or no domain transition from " << mycon.get()
<< " to another SELinux domain defined. Have you configured your "
"service correctly? https://source.android.com/security/selinux/"
"device-policy#label_new_services_and_address_denials. Note: this "
"error shows up even in permissive mode in order to make auditing "
"denials possible.";
}
if (rc < 0) {
return Error() << "Could not get process context";
}
return computed_context;
}
static bool ExpandArgsAndExecv(const std::vector<std::string>& args, bool sigstop) {
std::vector<std::string> expanded_args;
std::vector<char*> c_strings;
expanded_args.resize(args.size());
c_strings.push_back(const_cast<char*>(args[0].data()));
for (std::size_t i = 1; i < args.size(); ++i) {
auto expanded_arg = ExpandProps(args[i]);
if (!expanded_arg.ok()) {
LOG(FATAL) << args[0] << ": cannot expand arguments': " << expanded_arg.error();
}
expanded_args[i] = *expanded_arg;
c_strings.push_back(expanded_args[i].data());
}
c_strings.push_back(nullptr);
if (sigstop) {
kill(getpid(), SIGSTOP);
}
return execv(c_strings[0], c_strings.data()) == 0;
}
unsigned long Service::next_start_order_ = 1;
bool Service::is_exec_service_running_ = false;
std::chrono::time_point<std::chrono::steady_clock> Service::exec_service_started_;
Service::Service(const std::string& name, Subcontext* subcontext_for_restart_commands,
const std::vector<std::string>& args, bool from_apex)
: Service(name, 0, 0, 0, {}, 0, "", subcontext_for_restart_commands, args, from_apex) {}
Service::Service(const std::string& name, unsigned flags, uid_t uid, gid_t gid,
const std::vector<gid_t>& supp_gids, int namespace_flags,
const std::string& seclabel, Subcontext* subcontext_for_restart_commands,
const std::vector<std::string>& args, bool from_apex)
: name_(name),
classnames_({"default"}),
flags_(flags),
pid_(0),
crash_count_(0),
proc_attr_{.ioprio_class = IoSchedClass_NONE,
.ioprio_pri = 0,
.uid = uid,
.gid = gid,
.supp_gids = supp_gids,
.priority = 0},
namespaces_{.flags = namespace_flags},
seclabel_(seclabel),
subcontext_(subcontext_for_restart_commands),
onrestart_(false, subcontext_for_restart_commands, "<Service '" + name + "' onrestart>", 0,
"onrestart", {}),
oom_score_adjust_(DEFAULT_OOM_SCORE_ADJUST),
start_order_(0),
args_(args),
from_apex_(from_apex) {}
void Service::NotifyStateChange(const std::string& new_state) const {
if ((flags_ & SVC_TEMPORARY) != 0) {
// Services created by 'exec' are temporary and don't have properties tracking their state.
return;
}
std::string prop_name = "init.svc." + name_;
SetProperty(prop_name, new_state);
if (new_state == "running") {
uint64_t start_ns = time_started_.time_since_epoch().count();
std::string boottime_property = "ro.boottime." + name_;
if (GetProperty(boottime_property, "").empty()) {
SetProperty(boottime_property, std::to_string(start_ns));
}
}
// init.svc_debug_pid.* properties are only for tests, and should not be used
// on device for security checks.
std::string pid_property = "init.svc_debug_pid." + name_;
if (new_state == "running") {
SetProperty(pid_property, std::to_string(pid_));
} else if (new_state == "stopped") {
SetProperty(pid_property, "");
}
}
void Service::KillProcessGroup(int signal, bool report_oneshot) {
// If we've already seen a successful result from killProcessGroup*(), then we have removed
// the cgroup already and calling these functions a second time will simply result in an error.
// This is true regardless of which signal was sent.
// These functions handle their own logging, so no additional logging is needed.
if (!process_cgroup_empty_) {
LOG(INFO) << "Sending signal " << signal << " to service '" << name_ << "' (pid " << pid_
<< ") process group...";
int max_processes = 0;
int r;
if (signal == SIGTERM) {
r = killProcessGroupOnce(proc_attr_.uid, pid_, signal, &max_processes);
} else {
r = killProcessGroup(proc_attr_.uid, pid_, signal, &max_processes);
}
if (report_oneshot && max_processes > 0) {
LOG(WARNING)
<< "Killed " << max_processes
<< " additional processes from a oneshot process group for service '" << name_
<< "'. This is new behavior, previously child processes would not be killed in "
"this case.";
}
if (r == 0) process_cgroup_empty_ = true;
}
if (oom_score_adjust_ != DEFAULT_OOM_SCORE_ADJUST) {
LmkdUnregister(name_, pid_);
}
}
void Service::SetProcessAttributesAndCaps() {
// Keep capabilites on uid change.
if (capabilities_ && proc_attr_.uid) {
// If Android is running in a container, some securebits might already
// be locked, so don't change those.
unsigned long securebits = prctl(PR_GET_SECUREBITS);
if (securebits == -1UL) {
PLOG(FATAL) << "prctl(PR_GET_SECUREBITS) failed for " << name_;
}
securebits |= SECBIT_KEEP_CAPS | SECBIT_KEEP_CAPS_LOCKED;
if (prctl(PR_SET_SECUREBITS, securebits) != 0) {
PLOG(FATAL) << "prctl(PR_SET_SECUREBITS) failed for " << name_;
}
}
if (auto result = SetProcessAttributes(proc_attr_); !result.ok()) {
LOG(FATAL) << "cannot set attribute for " << name_ << ": " << result.error();
}
if (!seclabel_.empty()) {
if (setexeccon(seclabel_.c_str()) < 0) {
PLOG(FATAL) << "cannot setexeccon('" << seclabel_ << "') for " << name_;
}
}
if (capabilities_) {
if (!SetCapsForExec(*capabilities_)) {
LOG(FATAL) << "cannot set capabilities for " << name_;
}
} else if (proc_attr_.uid) {
// Inheritable caps can be non-zero when running in a container.
if (!DropInheritableCaps()) {
LOG(FATAL) << "cannot drop inheritable caps for " << name_;
}
}
}
void Service::Reap(const siginfo_t& siginfo) {
if (!(flags_ & SVC_ONESHOT) || (flags_ & SVC_RESTART)) {
KillProcessGroup(SIGKILL, false);
} else {
// Legacy behavior from ~2007 until Android R: this else branch did not exist and we did not
// kill the process group in this case.
if (SelinuxGetVendorAndroidVersion() >= __ANDROID_API_R__) {
// The new behavior in Android R is to kill these process groups in all cases. The
// 'true' parameter instructions KillProcessGroup() to report a warning message where it
// detects a difference in behavior has occurred.
KillProcessGroup(SIGKILL, true);
}
}
// Remove any socket resources we may have created.
for (const auto& socket : sockets_) {
if (socket.persist) {
continue;
}
auto path = ANDROID_SOCKET_DIR "/" + socket.name;
unlink(path.c_str());
}
for (const auto& f : reap_callbacks_) {
f(siginfo);
}
if ((siginfo.si_code != CLD_EXITED || siginfo.si_status != 0) && on_failure_reboot_target_) {
LOG(ERROR) << "Service with 'reboot_on_failure' option failed, shutting down system.";
trigger_shutdown(*on_failure_reboot_target_);
}
if (flags_ & SVC_EXEC) UnSetExec();
if (flags_ & SVC_TEMPORARY) return;
pid_ = 0;
flags_ &= (~SVC_RUNNING);
start_order_ = 0;
// Oneshot processes go into the disabled state on exit,
// except when manually restarted.
if ((flags_ & SVC_ONESHOT) && !(flags_ & SVC_RESTART) && !(flags_ & SVC_RESET)) {
flags_ |= SVC_DISABLED;
}
// Disabled and reset processes do not get restarted automatically.
if (flags_ & (SVC_DISABLED | SVC_RESET)) {
NotifyStateChange("stopped");
return;
}
#if INIT_FULL_SOURCES
static bool is_apex_updatable = android::sysprop::ApexProperties::updatable().value_or(false);
#else
static bool is_apex_updatable = false;
#endif
const bool is_process_updatable = !use_bootstrap_ns_ && is_apex_updatable;
// If we crash > 4 times in 'fatal_crash_window_' minutes or before boot_completed,
// reboot into bootloader or set crashing property
boot_clock::time_point now = boot_clock::now();
if (((flags_ & SVC_CRITICAL) || is_process_updatable) && !(flags_ & SVC_RESTART)) {
bool boot_completed = GetBoolProperty("sys.boot_completed", false);
if (now < time_crashed_ + fatal_crash_window_ || !boot_completed) {
if (++crash_count_ > 4) {
auto exit_reason = boot_completed ?
"in " + std::to_string(fatal_crash_window_.count()) + " minutes" :
"before boot completed";
if (flags_ & SVC_CRITICAL) {
if (!GetBoolProperty("init.svc_debug.no_fatal." + name_, false)) {
// Aborts into `fatal_reboot_target_'.
SetFatalRebootTarget(fatal_reboot_target_);
LOG(FATAL) << "critical process '" << name_ << "' exited 4 times "
<< exit_reason;
}
} else {
LOG(ERROR) << "process with updatable components '" << name_
<< "' exited 4 times " << exit_reason;
// Notifies update_verifier and apexd
SetProperty("sys.init.updatable_crashing_process_name", name_);
SetProperty("sys.init.updatable_crashing", "1");
}
}
} else {
time_crashed_ = now;
crash_count_ = 1;
}
}
flags_ &= (~SVC_RESTART);
flags_ |= SVC_RESTARTING;
// Execute all onrestart commands for this service.
onrestart_.ExecuteAllCommands();
NotifyStateChange("restarting");
return;
}
void Service::DumpState() const {
LOG(INFO) << "service " << name_;
LOG(INFO) << " class '" << Join(classnames_, " ") << "'";
LOG(INFO) << " exec " << Join(args_, " ");
for (const auto& socket : sockets_) {
LOG(INFO) << " socket " << socket.name;
}
for (const auto& file : files_) {
LOG(INFO) << " file " << file.name;
}
}
Result<void> Service::ExecStart() {
auto reboot_on_failure = make_scope_guard([this] {
if (on_failure_reboot_target_) {
trigger_shutdown(*on_failure_reboot_target_);
}
});
if (is_updatable() && !ServiceList::GetInstance().IsServicesUpdated()) {
// Don't delay the service for ExecStart() as the semantic is that
// the caller might depend on the side effect of the execution.
return Error() << "Cannot start an updatable service '" << name_
<< "' before configs from APEXes are all loaded";
}
flags_ |= SVC_ONESHOT;
if (auto result = Start(); !result.ok()) {
return result;
}
flags_ |= SVC_EXEC;
is_exec_service_running_ = true;
exec_service_started_ = std::chrono::steady_clock::now();
LOG(INFO) << "SVC_EXEC service '" << name_ << "' pid " << pid_ << " (uid " << proc_attr_.uid
<< " gid " << proc_attr_.gid << "+" << proc_attr_.supp_gids.size() << " context "
<< (!seclabel_.empty() ? seclabel_ : "default") << ") started; waiting...";
reboot_on_failure.Disable();
return {};
}
static void ClosePipe(const std::array<int, 2>* pipe) {
for (const auto fd : *pipe) {
if (fd >= 0) {
close(fd);
}
}
}
Result<void> Service::CheckConsole() {
if (!(flags_ & SVC_CONSOLE)) {
return {};
}
if (proc_attr_.console.empty()) {
proc_attr_.console = "/dev/" + GetProperty("ro.boot.console", "console");
}
// Make sure that open call succeeds to ensure a console driver is
// properly registered for the device node
int console_fd = open(proc_attr_.console.c_str(), O_RDWR | O_CLOEXEC);
if (console_fd < 0) {
flags_ |= SVC_DISABLED;
return ErrnoError() << "Couldn't open console '" << proc_attr_.console << "'";
}
close(console_fd);
return {};
}
// Configures the memory cgroup properties for the service.
void Service::ConfigureMemcg() {
if (swappiness_ != -1) {
if (!setProcessGroupSwappiness(proc_attr_.uid, pid_, swappiness_)) {
PLOG(ERROR) << "setProcessGroupSwappiness failed";
}
}
if (soft_limit_in_bytes_ != -1) {
if (!setProcessGroupSoftLimit(proc_attr_.uid, pid_, soft_limit_in_bytes_)) {
PLOG(ERROR) << "setProcessGroupSoftLimit failed";
}
}
size_t computed_limit_in_bytes = limit_in_bytes_;
if (limit_percent_ != -1) {
long page_size = sysconf(_SC_PAGESIZE);
long num_pages = sysconf(_SC_PHYS_PAGES);
if (page_size > 0 && num_pages > 0) {
size_t max_mem = SIZE_MAX;
if (size_t(num_pages) < SIZE_MAX / size_t(page_size)) {
max_mem = size_t(num_pages) * size_t(page_size);
}
computed_limit_in_bytes =
std::min(computed_limit_in_bytes, max_mem / 100 * limit_percent_);
}
}
if (!limit_property_.empty()) {
// This ends up overwriting computed_limit_in_bytes but only if the
// property is defined.
computed_limit_in_bytes =
android::base::GetUintProperty(limit_property_, computed_limit_in_bytes, SIZE_MAX);
}
if (computed_limit_in_bytes != size_t(-1)) {
if (!setProcessGroupLimit(proc_attr_.uid, pid_, computed_limit_in_bytes)) {
PLOG(ERROR) << "setProcessGroupLimit failed";
}
}
}
// Enters namespaces, sets environment variables, writes PID files and runs the service executable.
void Service::RunService(const std::optional<MountNamespace>& override_mount_namespace,
const std::vector<Descriptor>& descriptors,
std::unique_ptr<std::array<int, 2>, decltype(&ClosePipe)> pipefd) {
if (auto result = EnterNamespaces(namespaces_, name_, override_mount_namespace); !result.ok()) {
LOG(FATAL) << "Service '" << name_ << "' failed to set up namespaces: " << result.error();
}
for (const auto& [key, value] : environment_vars_) {
setenv(key.c_str(), value.c_str(), 1);
}
for (const auto& descriptor : descriptors) {
descriptor.Publish();
}
if (auto result = WritePidToFiles(&writepid_files_); !result.ok()) {
LOG(ERROR) << "failed to write pid to files: " << result.error();
}
// Wait until the cgroups have been created and until the cgroup controllers have been
// activated.
char byte = 0;
if (read((*pipefd)[0], &byte, 1) < 0) {
PLOG(ERROR) << "failed to read from notification channel";
}
pipefd.reset();
if (!byte) {
LOG(FATAL) << "Service '" << name_ << "' failed to start due to a fatal error";
_exit(EXIT_FAILURE);
}
if (task_profiles_.size() > 0 && !SetTaskProfiles(getpid(), task_profiles_)) {
LOG(ERROR) << "failed to set task profiles";
}
// As requested, set our gid, supplemental gids, uid, context, and
// priority. Aborts on failure.
SetProcessAttributesAndCaps();
if (!ExpandArgsAndExecv(args_, sigstop_)) {
PLOG(ERROR) << "cannot execv('" << args_[0]
<< "'). See the 'Debugging init' section of init's README.md for tips";
}
}
Result<void> Service::Start() {
auto reboot_on_failure = make_scope_guard([this] {
if (on_failure_reboot_target_) {
trigger_shutdown(*on_failure_reboot_target_);
}
});
if (is_updatable() && !ServiceList::GetInstance().IsServicesUpdated()) {
ServiceList::GetInstance().DelayService(*this);
return Error() << "Cannot start an updatable service '" << name_
<< "' before configs from APEXes are all loaded. "
<< "Queued for execution.";
}
bool disabled = (flags_ & (SVC_DISABLED | SVC_RESET));
ResetFlagsForStart();
// Running processes require no additional work --- if they're in the
// process of exiting, we've ensured that they will immediately restart
// on exit, unless they are ONESHOT. For ONESHOT service, if it's in
// stopping status, we just set SVC_RESTART flag so it will get restarted
// in Reap().
if (flags_ & SVC_RUNNING) {
if ((flags_ & SVC_ONESHOT) && disabled) {
flags_ |= SVC_RESTART;
}
// It is not an error to try to start a service that is already running.
reboot_on_failure.Disable();
return {};
}
std::unique_ptr<std::array<int, 2>, decltype(&ClosePipe)> pipefd(new std::array<int, 2>{-1, -1},
ClosePipe);
if (pipe(pipefd->data()) < 0) {
return ErrnoError() << "pipe()";
}
if (Result<void> result = CheckConsole(); !result.ok()) {
return result;
}
struct stat sb;
if (stat(args_[0].c_str(), &sb) == -1) {
flags_ |= SVC_DISABLED;
return ErrnoError() << "Cannot find '" << args_[0] << "'";
}
std::string scon;
if (!seclabel_.empty()) {
scon = seclabel_;
} else {
auto result = ComputeContextFromExecutable(args_[0]);
if (!result.ok()) {
return result.error();
}
scon = *result;
}
// APEXd is always started in the "current" namespace because it is the process to set up
// the current namespace.
const bool is_apexd = args_[0] == "/system/bin/apexd";
if (!IsDefaultMountNamespaceReady() && !is_apexd) {
// If this service is started before APEXes and corresponding linker configuration
// get available, mark it as pre-apexd one. Note that this marking is
// permanent. So for example, if the service is re-launched (e.g., due
// to crash), it is still recognized as pre-apexd... for consistency.
use_bootstrap_ns_ = true;
}
// For pre-apexd services, override mount namespace as "bootstrap" one before starting.
// Note: "ueventd" is supposed to be run in "default" mount namespace even if it's pre-apexd
// to support loading firmwares from APEXes.
std::optional<MountNamespace> override_mount_namespace;
if (name_ == "ueventd") {
override_mount_namespace = NS_DEFAULT;
} else if (use_bootstrap_ns_) {
override_mount_namespace = NS_BOOTSTRAP;
}
post_data_ = ServiceList::GetInstance().IsPostData();
LOG(INFO) << "starting service '" << name_ << "'...";
std::vector<Descriptor> descriptors;
for (const auto& socket : sockets_) {
if (auto result = socket.Create(scon); result.ok()) {
descriptors.emplace_back(std::move(*result));
} else {
LOG(INFO) << "Could not create socket '" << socket.name << "': " << result.error();
}
}
for (const auto& file : files_) {
if (auto result = file.Create(); result.ok()) {
descriptors.emplace_back(std::move(*result));
} else {
LOG(INFO) << "Could not open file '" << file.name << "': " << result.error();
}
}
pid_t pid = -1;
if (namespaces_.flags) {
pid = clone(nullptr, nullptr, namespaces_.flags | SIGCHLD, nullptr);
} else {
pid = fork();
}
if (pid == 0) {
umask(077);
RunService(override_mount_namespace, descriptors, std::move(pipefd));
_exit(127);
}
if (pid < 0) {
pid_ = 0;
return ErrnoError() << "Failed to fork";
}
if (oom_score_adjust_ != DEFAULT_OOM_SCORE_ADJUST) {
std::string oom_str = std::to_string(oom_score_adjust_);
std::string oom_file = StringPrintf("/proc/%d/oom_score_adj", pid);
if (!WriteStringToFile(oom_str, oom_file)) {
PLOG(ERROR) << "couldn't write oom_score_adj";
}
}
time_started_ = boot_clock::now();
pid_ = pid;
flags_ |= SVC_RUNNING;
start_order_ = next_start_order_++;
process_cgroup_empty_ = false;
bool use_memcg = swappiness_ != -1 || soft_limit_in_bytes_ != -1 || limit_in_bytes_ != -1 ||
limit_percent_ != -1 || !limit_property_.empty();
errno = -createProcessGroup(proc_attr_.uid, pid_, use_memcg);
if (errno != 0) {
if (char byte = 0; write((*pipefd)[1], &byte, 1) < 0) {
return ErrnoError() << "sending notification failed";
}
return Error() << "createProcessGroup(" << proc_attr_.uid << ", " << pid_
<< ") failed for service '" << name_ << "'";
}
if (use_memcg) {
ConfigureMemcg();
}
if (oom_score_adjust_ != DEFAULT_OOM_SCORE_ADJUST) {
LmkdRegister(name_, proc_attr_.uid, pid_, oom_score_adjust_);
}
if (char byte = 1; write((*pipefd)[1], &byte, 1) < 0) {
return ErrnoError() << "sending notification failed";
}
NotifyStateChange("running");
reboot_on_failure.Disable();
return {};
}
void Service::SetStartedInFirstStage(pid_t pid) {
LOG(INFO) << "adding first-stage service '" << name_ << "'...";
time_started_ = boot_clock::now(); // not accurate, but doesn't matter here
pid_ = pid;
flags_ |= SVC_RUNNING;
start_order_ = next_start_order_++;
NotifyStateChange("running");
}
void Service::ResetFlagsForStart() {
// Starting a service removes it from the disabled or reset state and
// immediately takes it out of the restarting state if it was in there.
flags_ &= ~(SVC_DISABLED | SVC_RESTARTING | SVC_RESET | SVC_RESTART | SVC_DISABLED_START);
}
Result<void> Service::StartIfNotDisabled() {
if (!(flags_ & SVC_DISABLED)) {
return Start();
} else {
flags_ |= SVC_DISABLED_START;
}
return {};
}
Result<void> Service::Enable() {
flags_ &= ~(SVC_DISABLED | SVC_RC_DISABLED);
if (flags_ & SVC_DISABLED_START) {
return Start();
}
return {};
}
void Service::Reset() {
StopOrReset(SVC_RESET);
}
void Service::Stop() {
StopOrReset(SVC_DISABLED);
}
void Service::Terminate() {
flags_ &= ~(SVC_RESTARTING | SVC_DISABLED_START);
flags_ |= SVC_DISABLED;
if (pid_) {
KillProcessGroup(SIGTERM);
NotifyStateChange("stopping");
}
}
void Service::Timeout() {
// All process state flags will be taken care of in Reap(), we really just want to kill the
// process here when it times out. Oneshot processes will transition to be disabled, and
// all other processes will transition to be restarting.
LOG(INFO) << "Service '" << name_ << "' expired its timeout of " << timeout_period_->count()
<< " seconds and will now be killed";
if (pid_) {
KillProcessGroup(SIGKILL);
NotifyStateChange("stopping");
}
}
void Service::Restart() {
if (flags_ & SVC_RUNNING) {
/* Stop, wait, then start the service. */
StopOrReset(SVC_RESTART);
} else if (!(flags_ & SVC_RESTARTING)) {
/* Just start the service since it's not running. */
if (auto result = Start(); !result.ok()) {
LOG(ERROR) << "Could not restart '" << name_ << "': " << result.error();
}
} /* else: Service is restarting anyways. */
}
// The how field should be either SVC_DISABLED, SVC_RESET, or SVC_RESTART.
void Service::StopOrReset(int how) {
// The service is still SVC_RUNNING until its process exits, but if it has
// already exited it shoudn't attempt a restart yet.
flags_ &= ~(SVC_RESTARTING | SVC_DISABLED_START);
if ((how != SVC_DISABLED) && (how != SVC_RESET) && (how != SVC_RESTART)) {
// An illegal flag: default to SVC_DISABLED.
how = SVC_DISABLED;
}
// If the service has not yet started, prevent it from auto-starting with its class.
if (how == SVC_RESET) {
flags_ |= (flags_ & SVC_RC_DISABLED) ? SVC_DISABLED : SVC_RESET;
} else {
flags_ |= how;
}
// Make sure it's in right status when a restart immediately follow a
// stop/reset or vice versa.
if (how == SVC_RESTART) {
flags_ &= (~(SVC_DISABLED | SVC_RESET));
} else {
flags_ &= (~SVC_RESTART);
}
if (pid_) {
KillProcessGroup(SIGKILL);
NotifyStateChange("stopping");
} else {
NotifyStateChange("stopped");
}
}
Result<std::unique_ptr<Service>> Service::MakeTemporaryOneshotService(
const std::vector<std::string>& args) {
// Parse the arguments: exec [SECLABEL [UID [GID]*] --] COMMAND ARGS...
// SECLABEL can be a - to denote default
std::size_t command_arg = 1;
for (std::size_t i = 1; i < args.size(); ++i) {
if (args[i] == "--") {
command_arg = i + 1;
break;
}
}
if (command_arg > 4 + NR_SVC_SUPP_GIDS) {
return Error() << "exec called with too many supplementary group ids";
}
if (command_arg >= args.size()) {
return Error() << "exec called without command";
}
std::vector<std::string> str_args(args.begin() + command_arg, args.end());
static size_t exec_count = 0;
exec_count++;
std::string name = "exec " + std::to_string(exec_count) + " (" + Join(str_args, " ") + ")";
unsigned flags = SVC_ONESHOT | SVC_TEMPORARY;
unsigned namespace_flags = 0;
std::string seclabel = "";
if (command_arg > 2 && args[1] != "-") {
seclabel = args[1];
}
Result<uid_t> uid = 0;
if (command_arg > 3) {
uid = DecodeUid(args[2]);
if (!uid.ok()) {
return Error() << "Unable to decode UID for '" << args[2] << "': " << uid.error();
}
}
Result<gid_t> gid = 0;
std::vector<gid_t> supp_gids;
if (command_arg > 4) {
gid = DecodeUid(args[3]);
if (!gid.ok()) {
return Error() << "Unable to decode GID for '" << args[3] << "': " << gid.error();
}
std::size_t nr_supp_gids = command_arg - 1 /* -- */ - 4 /* exec SECLABEL UID GID */;
for (size_t i = 0; i < nr_supp_gids; ++i) {
auto supp_gid = DecodeUid(args[4 + i]);
if (!supp_gid.ok()) {
return Error() << "Unable to decode GID for '" << args[4 + i]
<< "': " << supp_gid.error();
}
supp_gids.push_back(*supp_gid);
}
}
return std::make_unique<Service>(name, flags, *uid, *gid, supp_gids, namespace_flags, seclabel,
nullptr, str_args, false);
}
// This is used for snapuserd_proxy, which hands off a socket to snapuserd. It's
// a special case to support the daemon launched in first-stage init. The persist
// feature is not part of the init language and is only used here.
bool Service::MarkSocketPersistent(const std::string& socket_name) {
for (auto& socket : sockets_) {
if (socket.name == socket_name) {
socket.persist = true;
return true;
}
}
return false;
}
} // namespace init
} // namespace android
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