/*
* 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/input.h>
#include <linux/securebits.h>
#include <sched.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <termios.h>
#include <unistd.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <hidl-util/FQName.h>
#include <processgroup/processgroup.h>
#include <selinux/selinux.h>
#include <system/thread_defs.h>
#include "rlimit_parser.h"
#include "util.h"
#if defined(__ANDROID__)
#include <android/api-level.h>
#include <sys/system_properties.h>
#include "init.h"
#include "mount_namespace.h"
#include "property_service.h"
#include "selinux.h"
#else
#include "host_init_stubs.h"
#endif
using android::base::boot_clock;
using android::base::GetProperty;
using android::base::Join;
using android::base::ParseInt;
using android::base::Split;
using android::base::StartsWith;
using android::base::StringPrintf;
using android::base::unique_fd;
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> mycon(raw_con);
if (getfilecon(service_path.c_str(), &raw_filecon) == -1) {
return Error() << "Could not get file context";
}
std::unique_ptr<char> filecon(raw_filecon);
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";
}
if (rc < 0) {
return Error() << "Could not get process context";
}
return computed_context;
}
Result<Success> Service::SetUpMountNamespace() const {
constexpr unsigned int kSafeFlags = MS_NODEV | MS_NOEXEC | MS_NOSUID;
// Recursively remount / as slave like zygote does so unmounting and mounting /proc
// doesn't interfere with the parent namespace's /proc mount. This will also
// prevent any other mounts/unmounts initiated by the service from interfering
// with the parent namespace but will still allow mount events from the parent
// namespace to propagate to the child.
if (mount("rootfs", "/", nullptr, (MS_SLAVE | MS_REC), nullptr) == -1) {
return ErrnoError() << "Could not remount(/) recursively as slave";
}
// umount() then mount() /proc and/or /sys
// Note that it is not sufficient to mount with MS_REMOUNT.
if (namespace_flags_ & CLONE_NEWPID) {
if (umount("/proc") == -1) {
return ErrnoError() << "Could not umount(/proc)";
}
if (mount("", "/proc", "proc", kSafeFlags, "") == -1) {
return ErrnoError() << "Could not mount(/proc)";
}
}
bool remount_sys = std::any_of(namespaces_to_enter_.begin(), namespaces_to_enter_.end(),
[](const auto& entry) { return entry.first == CLONE_NEWNET; });
if (remount_sys) {
if (umount2("/sys", MNT_DETACH) == -1) {
return ErrnoError() << "Could not umount(/sys)";
}
if (mount("", "/sys", "sysfs", kSafeFlags, "") == -1) {
return ErrnoError() << "Could not mount(/sys)";
}
}
return Success();
}
Result<Success> Service::SetUpPidNamespace() const {
if (prctl(PR_SET_NAME, name_.c_str()) == -1) {
return ErrnoError() << "Could not set name";
}
pid_t child_pid = fork();
if (child_pid == -1) {
return ErrnoError() << "Could not fork init inside the PID namespace";
}
if (child_pid > 0) {
// So that we exit with the right status.
static int init_exitstatus = 0;
signal(SIGTERM, [](int) { _exit(init_exitstatus); });
pid_t waited_pid;
int status;
while ((waited_pid = wait(&status)) > 0) {
// This loop will end when there are no processes left inside the
// PID namespace or when the init process inside the PID namespace
// gets a signal.
if (waited_pid == child_pid) {
init_exitstatus = status;
}
}
if (!WIFEXITED(init_exitstatus)) {
_exit(EXIT_FAILURE);
}
_exit(WEXITSTATUS(init_exitstatus));
}
return Success();
}
Result<Success> Service::EnterNamespaces() const {
for (const auto& [nstype, path] : namespaces_to_enter_) {
auto fd = unique_fd{open(path.c_str(), O_RDONLY | O_CLOEXEC)};
if (fd == -1) {
return ErrnoError() << "Could not open namespace at " << path;
}
if (setns(fd, nstype) == -1) {
return ErrnoError() << "Could not setns() namespace at " << path;
}
}
return Success();
}
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) {
if (!expand_props(args[i], &expanded_args[i])) {
LOG(FATAL) << args[0] << ": cannot expand '" << args[i] << "'";
}
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;
}
static bool IsRuntimeApexReady() {
struct stat buf;
return stat("/apex/com.android.runtime/", &buf) == 0;
}
unsigned long Service::next_start_order_ = 1;
bool Service::is_exec_service_running_ = false;
Service::Service(const std::string& name, Subcontext* subcontext_for_restart_commands,
const std::vector<std::string>& args)
: Service(name, 0, 0, 0, {}, 0, "", subcontext_for_restart_commands, args) {}
Service::Service(const std::string& name, unsigned flags, uid_t uid, gid_t gid,
const std::vector<gid_t>& supp_gids, unsigned namespace_flags,
const std::string& seclabel, Subcontext* subcontext_for_restart_commands,
const std::vector<std::string>& args)
: name_(name),
classnames_({"default"}),
flags_(flags),
pid_(0),
crash_count_(0),
uid_(uid),
gid_(gid),
supp_gids_(supp_gids),
namespace_flags_(namespace_flags),
seclabel_(seclabel),
onrestart_(false, subcontext_for_restart_commands, "<Service '" + name + "' onrestart>", 0,
"onrestart", {}),
ioprio_class_(IoSchedClass_NONE),
ioprio_pri_(0),
priority_(0),
oom_score_adjust_(-1000),
start_order_(0),
args_(args) {}
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_;
property_set(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()) {
property_set(boottime_property, std::to_string(start_ns));
}
}
}
void Service::KillProcessGroup(int signal) {
// 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 r;
if (signal == SIGTERM) {
r = killProcessGroupOnce(uid_, pid_, signal);
} else {
r = killProcessGroup(uid_, pid_, signal);
}
if (r == 0) process_cgroup_empty_ = true;
}
}
void Service::SetProcessAttributes() {
for (const auto& rlimit : rlimits_) {
if (setrlimit(rlimit.first, &rlimit.second) == -1) {
LOG(FATAL) << StringPrintf("setrlimit(%d, {rlim_cur=%ld, rlim_max=%ld}) failed",
rlimit.first, rlimit.second.rlim_cur, rlimit.second.rlim_max);
}
}
// Keep capabilites on uid change.
if (capabilities_ && 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_;
}
}
// TODO: work out why this fails for `console` then upgrade to FATAL.
if (setpgid(0, getpid()) == -1) PLOG(ERROR) << "setpgid failed for " << name_;
if (gid_) {
if (setgid(gid_) != 0) {
PLOG(FATAL) << "setgid failed for " << name_;
}
}
if (setgroups(supp_gids_.size(), &supp_gids_[0]) != 0) {
PLOG(FATAL) << "setgroups failed for " << name_;
}
if (uid_) {
if (setuid(uid_) != 0) {
PLOG(FATAL) << "setuid failed for " << name_;
}
}
if (!seclabel_.empty()) {
if (setexeccon(seclabel_.c_str()) < 0) {
PLOG(FATAL) << "cannot setexeccon('" << seclabel_ << "') for " << name_;
}
}
if (priority_ != 0) {
if (setpriority(PRIO_PROCESS, 0, priority_) != 0) {
PLOG(FATAL) << "setpriority failed for " << name_;
}
}
if (capabilities_) {
if (!SetCapsForExec(*capabilities_)) {
LOG(FATAL) << "cannot set capabilities for " << name_;
}
} else if (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);
}
// Remove any descriptor resources we may have created.
std::for_each(descriptors_.begin(), descriptors_.end(),
std::bind(&DescriptorInfo::Clean, std::placeholders::_1));
for (const auto& f : reap_callbacks_) {
f(siginfo);
}
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 we crash > 4 times in 4 minutes or before boot_completed,
// reboot into bootloader or set crashing property
boot_clock::time_point now = boot_clock::now();
if (((flags_ & SVC_CRITICAL) || !pre_apexd_) && !(flags_ & SVC_RESTART)) {
bool boot_completed = android::base::GetBoolProperty("sys.boot_completed", false);
if (now < time_crashed_ + 4min || !boot_completed) {
if (++crash_count_ > 4) {
if (flags_ & SVC_CRITICAL) {
// Aborts into bootloader
LOG(FATAL) << "critical process '" << name_ << "' exited 4 times "
<< (boot_completed ? "in 4 minutes" : "before boot completed");
} else {
LOG(ERROR) << "updatable process '" << name_ << "' exited 4 times "
<< (boot_completed ? "in 4 minutes" : "before boot completed");
// Notifies update_verifier and apexd
property_set("ro.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_, " ");
std::for_each(descriptors_.begin(), descriptors_.end(),
[] (const auto& info) { LOG(INFO) << *info; });
}
Result<Success> Service::ParseCapabilities(std::vector<std::string>&& args) {
capabilities_ = 0;
if (!CapAmbientSupported()) {
return Error()
<< "capabilities requested but the kernel does not support ambient capabilities";
}
unsigned int last_valid_cap = GetLastValidCap();
if (last_valid_cap >= capabilities_->size()) {
LOG(WARNING) << "last valid run-time capability is larger than CAP_LAST_CAP";
}
for (size_t i = 1; i < args.size(); i++) {
const std::string& arg = args[i];
int res = LookupCap(arg);
if (res < 0) {
return Error() << StringPrintf("invalid capability '%s'", arg.c_str());
}
unsigned int cap = static_cast<unsigned int>(res); // |res| is >= 0.
if (cap > last_valid_cap) {
return Error() << StringPrintf("capability '%s' not supported by the kernel",
arg.c_str());
}
(*capabilities_)[cap] = true;
}
return Success();
}
Result<Success> Service::ParseClass(std::vector<std::string>&& args) {
classnames_ = std::set<std::string>(args.begin() + 1, args.end());
return Success();
}
Result<Success> Service::ParseConsole(std::vector<std::string>&& args) {
flags_ |= SVC_CONSOLE;
console_ = args.size() > 1 ? "/dev/" + args[1] : "";
return Success();
}
Result<Success> Service::ParseCritical(std::vector<std::string>&& args) {
flags_ |= SVC_CRITICAL;
return Success();
}
Result<Success> Service::ParseDisabled(std::vector<std::string>&& args) {
flags_ |= SVC_DISABLED;
flags_ |= SVC_RC_DISABLED;
return Success();
}
Result<Success> Service::ParseEnterNamespace(std::vector<std::string>&& args) {
if (args[1] != "net") {
return Error() << "Init only supports entering network namespaces";
}
if (!namespaces_to_enter_.empty()) {
return Error() << "Only one network namespace may be entered";
}
// Network namespaces require that /sys is remounted, otherwise the old adapters will still be
// present. Therefore, they also require mount namespaces.
namespace_flags_ |= CLONE_NEWNS;
namespaces_to_enter_.emplace_back(CLONE_NEWNET, std::move(args[2]));
return Success();
}
Result<Success> Service::ParseGroup(std::vector<std::string>&& args) {
auto gid = DecodeUid(args[1]);
if (!gid) {
return Error() << "Unable to decode GID for '" << args[1] << "': " << gid.error();
}
gid_ = *gid;
for (std::size_t n = 2; n < args.size(); n++) {
gid = DecodeUid(args[n]);
if (!gid) {
return Error() << "Unable to decode GID for '" << args[n] << "': " << gid.error();
}
supp_gids_.emplace_back(*gid);
}
return Success();
}
Result<Success> Service::ParsePriority(std::vector<std::string>&& args) {
priority_ = 0;
if (!ParseInt(args[1], &priority_,
static_cast<int>(ANDROID_PRIORITY_HIGHEST), // highest is negative
static_cast<int>(ANDROID_PRIORITY_LOWEST))) {
return Error() << StringPrintf("process priority value must be range %d - %d",
ANDROID_PRIORITY_HIGHEST, ANDROID_PRIORITY_LOWEST);
}
return Success();
}
Result<Success> Service::ParseInterface(std::vector<std::string>&& args) {
const std::string& interface_name = args[1];
const std::string& instance_name = args[2];
FQName fq_name;
if (!FQName::parse(interface_name, &fq_name)) {
return Error() << "Invalid fully-qualified name for interface '" << interface_name << "'";
}
if (!fq_name.isFullyQualified()) {
return Error() << "Interface name not fully-qualified '" << interface_name << "'";
}
if (fq_name.isValidValueName()) {
return Error() << "Interface name must not be a value name '" << interface_name << "'";
}
const std::string fullname = interface_name + "/" + instance_name;
for (const auto& svc : ServiceList::GetInstance()) {
if (svc->interfaces().count(fullname) > 0) {
return Error() << "Interface '" << fullname << "' redefined in " << name()
<< " but is already defined by " << svc->name();
}
}
interfaces_.insert(fullname);
return Success();
}
Result<Success> Service::ParseIoprio(std::vector<std::string>&& args) {
if (!ParseInt(args[2], &ioprio_pri_, 0, 7)) {
return Error() << "priority value must be range 0 - 7";
}
if (args[1] == "rt") {
ioprio_class_ = IoSchedClass_RT;
} else if (args[1] == "be") {
ioprio_class_ = IoSchedClass_BE;
} else if (args[1] == "idle") {
ioprio_class_ = IoSchedClass_IDLE;
} else {
return Error() << "ioprio option usage: ioprio <rt|be|idle> <0-7>";
}
return Success();
}
Result<Success> Service::ParseKeycodes(std::vector<std::string>&& args) {
auto it = args.begin() + 1;
if (args.size() == 2 && StartsWith(args[1], "$")) {
std::string expanded;
if (!expand_props(args[1], &expanded)) {
return Error() << "Could not expand property '" << args[1] << "'";
}
// If the property is not set, it defaults to none, in which case there are no keycodes
// for this service.
if (expanded == "none") {
return Success();
}
args = Split(expanded, ",");
it = args.begin();
}
for (; it != args.end(); ++it) {
int code;
if (ParseInt(*it, &code, 0, KEY_MAX)) {
for (auto& key : keycodes_) {
if (key == code) return Error() << "duplicate keycode: " << *it;
}
keycodes_.insert(std::upper_bound(keycodes_.begin(), keycodes_.end(), code), code);
} else {
return Error() << "invalid keycode: " << *it;
}
}
return Success();
}
Result<Success> Service::ParseOneshot(std::vector<std::string>&& args) {
flags_ |= SVC_ONESHOT;
return Success();
}
Result<Success> Service::ParseOnrestart(std::vector<std::string>&& args) {
args.erase(args.begin());
int line = onrestart_.NumCommands() + 1;
if (auto result = onrestart_.AddCommand(std::move(args), line); !result) {
return Error() << "cannot add Onrestart command: " << result.error();
}
return Success();
}
Result<Success> Service::ParseNamespace(std::vector<std::string>&& args) {
for (size_t i = 1; i < args.size(); i++) {
if (args[i] == "pid") {
namespace_flags_ |= CLONE_NEWPID;
// PID namespaces require mount namespaces.
namespace_flags_ |= CLONE_NEWNS;
} else if (args[i] == "mnt") {
namespace_flags_ |= CLONE_NEWNS;
} else {
return Error() << "namespace must be 'pid' or 'mnt'";
}
}
return Success();
}
Result<Success> Service::ParseOomScoreAdjust(std::vector<std::string>&& args) {
if (!ParseInt(args[1], &oom_score_adjust_, -1000, 1000)) {
return Error() << "oom_score_adjust value must be in range -1000 - +1000";
}
return Success();
}
Result<Success> Service::ParseOverride(std::vector<std::string>&& args) {
override_ = true;
return Success();
}
Result<Success> Service::ParseMemcgSwappiness(std::vector<std::string>&& args) {
if (!ParseInt(args[1], &swappiness_, 0)) {
return Error() << "swappiness value must be equal or greater than 0";
}
return Success();
}
Result<Success> Service::ParseMemcgLimitInBytes(std::vector<std::string>&& args) {
if (!ParseInt(args[1], &limit_in_bytes_, 0)) {
return Error() << "limit_in_bytes value must be equal or greater than 0";
}
return Success();
}
Result<Success> Service::ParseMemcgLimitPercent(std::vector<std::string>&& args) {
if (!ParseInt(args[1], &limit_percent_, 0)) {
return Error() << "limit_percent value must be equal or greater than 0";
}
return Success();
}
Result<Success> Service::ParseMemcgLimitProperty(std::vector<std::string>&& args) {
limit_property_ = std::move(args[1]);
return Success();
}
Result<Success> Service::ParseMemcgSoftLimitInBytes(std::vector<std::string>&& args) {
if (!ParseInt(args[1], &soft_limit_in_bytes_, 0)) {
return Error() << "soft_limit_in_bytes value must be equal or greater than 0";
}
return Success();
}
Result<Success> Service::ParseProcessRlimit(std::vector<std::string>&& args) {
auto rlimit = ParseRlimit(args);
if (!rlimit) return rlimit.error();
rlimits_.emplace_back(*rlimit);
return Success();
}
Result<Success> Service::ParseRestartPeriod(std::vector<std::string>&& args) {
int period;
if (!ParseInt(args[1], &period, 5)) {
return Error() << "restart_period value must be an integer >= 5";
}
restart_period_ = std::chrono::seconds(period);
return Success();
}
Result<Success> Service::ParseSeclabel(std::vector<std::string>&& args) {
seclabel_ = std::move(args[1]);
return Success();
}
Result<Success> Service::ParseSigstop(std::vector<std::string>&& args) {
sigstop_ = true;
return Success();
}
Result<Success> Service::ParseSetenv(std::vector<std::string>&& args) {
environment_vars_.emplace_back(std::move(args[1]), std::move(args[2]));
return Success();
}
Result<Success> Service::ParseShutdown(std::vector<std::string>&& args) {
if (args[1] == "critical") {
flags_ |= SVC_SHUTDOWN_CRITICAL;
return Success();
}
return Error() << "Invalid shutdown option";
}
Result<Success> Service::ParseTimeoutPeriod(std::vector<std::string>&& args) {
int period;
if (!ParseInt(args[1], &period, 1)) {
return Error() << "timeout_period value must be an integer >= 1";
}
timeout_period_ = std::chrono::seconds(period);
return Success();
}
template <typename T>
Result<Success> Service::AddDescriptor(std::vector<std::string>&& args) {
int perm = args.size() > 3 ? std::strtoul(args[3].c_str(), 0, 8) : -1;
Result<uid_t> uid = 0;
Result<gid_t> gid = 0;
std::string context = args.size() > 6 ? args[6] : "";
if (args.size() > 4) {
uid = DecodeUid(args[4]);
if (!uid) {
return Error() << "Unable to find UID for '" << args[4] << "': " << uid.error();
}
}
if (args.size() > 5) {
gid = DecodeUid(args[5]);
if (!gid) {
return Error() << "Unable to find GID for '" << args[5] << "': " << gid.error();
}
}
auto descriptor = std::make_unique<T>(args[1], args[2], *uid, *gid, perm, context);
auto old =
std::find_if(descriptors_.begin(), descriptors_.end(),
[&descriptor] (const auto& other) { return descriptor.get() == other.get(); });
if (old != descriptors_.end()) {
return Error() << "duplicate descriptor " << args[1] << " " << args[2];
}
descriptors_.emplace_back(std::move(descriptor));
return Success();
}
// name type perm [ uid gid context ]
Result<Success> Service::ParseSocket(std::vector<std::string>&& args) {
if (!StartsWith(args[2], "dgram") && !StartsWith(args[2], "stream") &&
!StartsWith(args[2], "seqpacket")) {
return Error() << "socket type must be 'dgram', 'stream' or 'seqpacket'";
}
return AddDescriptor<SocketInfo>(std::move(args));
}
// name type perm [ uid gid context ]
Result<Success> Service::ParseFile(std::vector<std::string>&& args) {
if (args[2] != "r" && args[2] != "w" && args[2] != "rw") {
return Error() << "file type must be 'r', 'w' or 'rw'";
}
std::string expanded;
if (!expand_props(args[1], &expanded)) {
return Error() << "Could not expand property in file path '" << args[1] << "'";
}
args[1] = std::move(expanded);
if ((args[1][0] != '/') || (args[1].find("../") != std::string::npos)) {
return Error() << "file name must not be relative";
}
return AddDescriptor<FileInfo>(std::move(args));
}
Result<Success> Service::ParseUser(std::vector<std::string>&& args) {
auto uid = DecodeUid(args[1]);
if (!uid) {
return Error() << "Unable to find UID for '" << args[1] << "': " << uid.error();
}
uid_ = *uid;
return Success();
}
Result<Success> Service::ParseWritepid(std::vector<std::string>&& args) {
args.erase(args.begin());
writepid_files_ = std::move(args);
return Success();
}
Result<Success> Service::ParseUpdatable(std::vector<std::string>&& args) {
updatable_ = true;
return Success();
}
class Service::OptionParserMap : public KeywordMap<OptionParser> {
public:
OptionParserMap() {}
private:
const Map& map() const override;
};
const Service::OptionParserMap::Map& Service::OptionParserMap::map() const {
constexpr std::size_t kMax = std::numeric_limits<std::size_t>::max();
// clang-format off
static const Map option_parsers = {
{"capabilities",
{0, kMax, &Service::ParseCapabilities}},
{"class", {1, kMax, &Service::ParseClass}},
{"console", {0, 1, &Service::ParseConsole}},
{"critical", {0, 0, &Service::ParseCritical}},
{"disabled", {0, 0, &Service::ParseDisabled}},
{"enter_namespace",
{2, 2, &Service::ParseEnterNamespace}},
{"file", {2, 2, &Service::ParseFile}},
{"group", {1, NR_SVC_SUPP_GIDS + 1, &Service::ParseGroup}},
{"interface", {2, 2, &Service::ParseInterface}},
{"ioprio", {2, 2, &Service::ParseIoprio}},
{"keycodes", {1, kMax, &Service::ParseKeycodes}},
{"memcg.limit_in_bytes",
{1, 1, &Service::ParseMemcgLimitInBytes}},
{"memcg.limit_percent",
{1, 1, &Service::ParseMemcgLimitPercent}},
{"memcg.limit_property",
{1, 1, &Service::ParseMemcgLimitProperty}},
{"memcg.soft_limit_in_bytes",
{1, 1, &Service::ParseMemcgSoftLimitInBytes}},
{"memcg.swappiness",
{1, 1, &Service::ParseMemcgSwappiness}},
{"namespace", {1, 2, &Service::ParseNamespace}},
{"oneshot", {0, 0, &Service::ParseOneshot}},
{"onrestart", {1, kMax, &Service::ParseOnrestart}},
{"oom_score_adjust",
{1, 1, &Service::ParseOomScoreAdjust}},
{"override", {0, 0, &Service::ParseOverride}},
{"priority", {1, 1, &Service::ParsePriority}},
{"restart_period",
{1, 1, &Service::ParseRestartPeriod}},
{"rlimit", {3, 3, &Service::ParseProcessRlimit}},
{"seclabel", {1, 1, &Service::ParseSeclabel}},
{"setenv", {2, 2, &Service::ParseSetenv}},
{"shutdown", {1, 1, &Service::ParseShutdown}},
{"sigstop", {0, 0, &Service::ParseSigstop}},
{"socket", {3, 6, &Service::ParseSocket}},
{"timeout_period",
{1, 1, &Service::ParseTimeoutPeriod}},
{"updatable", {0, 0, &Service::ParseUpdatable}},
{"user", {1, 1, &Service::ParseUser}},
{"writepid", {1, kMax, &Service::ParseWritepid}},
};
// clang-format on
return option_parsers;
}
Result<Success> Service::ParseLine(std::vector<std::string>&& args) {
static const OptionParserMap parser_map;
auto parser = parser_map.FindFunction(args);
if (!parser) return parser.error();
return std::invoke(*parser, this, std::move(args));
}
Result<Success> Service::ExecStart() {
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) {
return result;
}
flags_ |= SVC_EXEC;
is_exec_service_running_ = true;
LOG(INFO) << "SVC_EXEC service '" << name_ << "' pid " << pid_ << " (uid " << uid_ << " gid "
<< gid_ << "+" << supp_gids_.size() << " context "
<< (!seclabel_.empty() ? seclabel_ : "default") << ") started; waiting...";
return Success();
}
Result<Success> Service::Start() {
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));
// 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));
// 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.
return Success();
}
bool needs_console = (flags_ & SVC_CONSOLE);
if (needs_console) {
if (console_.empty()) {
console_ = default_console;
}
// Make sure that open call succeeds to ensure a console driver is
// properly registered for the device node
int console_fd = open(console_.c_str(), O_RDWR | O_CLOEXEC);
if (console_fd < 0) {
flags_ |= SVC_DISABLED;
return ErrnoError() << "Couldn't open console '" << console_ << "'";
}
close(console_fd);
}
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) {
return result.error();
}
scon = *result;
}
if (!IsRuntimeApexReady() && !pre_apexd_) {
// If this service is started before the runtime APEX gets 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.
pre_apexd_ = true;
}
post_data_ = ServiceList::GetInstance().IsPostData();
LOG(INFO) << "starting service '" << name_ << "'...";
pid_t pid = -1;
if (namespace_flags_) {
pid = clone(nullptr, nullptr, namespace_flags_ | SIGCHLD, nullptr);
} else {
pid = fork();
}
if (pid == 0) {
umask(077);
if (auto result = EnterNamespaces(); !result) {
LOG(FATAL) << "Service '" << name_ << "' could not enter namespaces: " << result.error();
}
#if defined(__ANDROID__)
if (pre_apexd_) {
if (!SwitchToBootstrapMountNamespaceIfNeeded()) {
LOG(FATAL) << "Service '" << name_ << "' could not enter "
<< "into the bootstrap mount namespace";
}
}
#endif
if (namespace_flags_ & CLONE_NEWNS) {
if (auto result = SetUpMountNamespace(); !result) {
LOG(FATAL) << "Service '" << name_
<< "' could not set up mount namespace: " << result.error();
}
}
if (namespace_flags_ & CLONE_NEWPID) {
// This will fork again to run an init process inside the PID
// namespace.
if (auto result = SetUpPidNamespace(); !result) {
LOG(FATAL) << "Service '" << name_
<< "' could not set up PID namespace: " << result.error();
}
}
for (const auto& [key, value] : environment_vars_) {
setenv(key.c_str(), value.c_str(), 1);
}
std::for_each(descriptors_.begin(), descriptors_.end(),
std::bind(&DescriptorInfo::CreateAndPublish, std::placeholders::_1, scon));
// See if there were "writepid" instructions to write to files under cpuset path.
std::string cpuset_path;
if (CgroupGetControllerPath("cpuset", &cpuset_path)) {
auto cpuset_predicate = [&cpuset_path](const std::string& path) {
return StartsWith(path, cpuset_path + "/");
};
auto iter =
std::find_if(writepid_files_.begin(), writepid_files_.end(), cpuset_predicate);
if (iter == writepid_files_.end()) {
// There were no "writepid" instructions for cpusets, check if the system default
// cpuset is specified to be used for the process.
std::string default_cpuset = GetProperty("ro.cpuset.default", "");
if (!default_cpuset.empty()) {
// Make sure the cpuset name starts and ends with '/'.
// A single '/' means the 'root' cpuset.
if (default_cpuset.front() != '/') {
default_cpuset.insert(0, 1, '/');
}
if (default_cpuset.back() != '/') {
default_cpuset.push_back('/');
}
writepid_files_.push_back(
StringPrintf("%s%stasks", cpuset_path.c_str(), default_cpuset.c_str()));
}
}
} else {
LOG(ERROR) << "cpuset cgroup controller is not mounted!";
}
std::string pid_str = std::to_string(getpid());
for (const auto& file : writepid_files_) {
if (!WriteStringToFile(pid_str, file)) {
PLOG(ERROR) << "couldn't write " << pid_str << " to " << file;
}
}
if (ioprio_class_ != IoSchedClass_NONE) {
if (android_set_ioprio(getpid(), ioprio_class_, ioprio_pri_)) {
PLOG(ERROR) << "failed to set pid " << getpid()
<< " ioprio=" << ioprio_class_ << "," << ioprio_pri_;
}
}
if (needs_console) {
setsid();
OpenConsole();
} else {
ZapStdio();
}
// As requested, set our gid, supplemental gids, uid, context, and
// priority. Aborts on failure.
SetProcessAttributes();
if (!ExpandArgsAndExecv(args_, sigstop_)) {
PLOG(ERROR) << "cannot execve('" << args_[0] << "')";
}
_exit(127);
}
if (pid < 0) {
pid_ = 0;
return ErrnoError() << "Failed to fork";
}
if (oom_score_adjust_ != -1000) {
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(uid_, pid_, use_memcg);
if (errno != 0) {
PLOG(ERROR) << "createProcessGroup(" << uid_ << ", " << pid_ << ") failed for service '"
<< name_ << "'";
} else if (use_memcg) {
if (swappiness_ != -1) {
if (!setProcessGroupSwappiness(uid_, pid_, swappiness_)) {
PLOG(ERROR) << "setProcessGroupSwappiness failed";
}
}
if (soft_limit_in_bytes_ != -1) {
if (!setProcessGroupSoftLimit(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(uid_, pid_, computed_limit_in_bytes)) {
PLOG(ERROR) << "setProcessGroupLimit failed";
}
}
}
NotifyStateChange("running");
return Success();
}
Result<Success> Service::StartIfNotDisabled() {
if (!(flags_ & SVC_DISABLED)) {
return Start();
} else {
flags_ |= SVC_DISABLED_START;
}
return Success();
}
Result<Success> Service::Enable() {
flags_ &= ~(SVC_DISABLED | SVC_RC_DISABLED);
if (flags_ & SVC_DISABLED_START) {
return Start();
}
return Success();
}
void Service::Reset() {
StopOrReset(SVC_RESET);
}
void Service::ResetIfPostData() {
if (post_data_) {
if (flags_ & SVC_RUNNING) {
running_at_post_data_reset_ = true;
}
StopOrReset(SVC_RESET);
}
}
Result<Success> Service::StartIfPostData() {
// Start the service, but only if it was started after /data was mounted,
// and it was still running when we reset the post-data services.
if (running_at_post_data_reset_) {
return Start();
}
return Success();
}
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) {
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");
}
}
void Service::ZapStdio() const {
int fd;
fd = open("/dev/null", O_RDWR);
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
close(fd);
}
void Service::OpenConsole() const {
int fd = open(console_.c_str(), O_RDWR);
if (fd == -1) fd = open("/dev/null", O_RDWR);
ioctl(fd, TIOCSCTTY, 0);
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
close(fd);
}
ServiceList::ServiceList() {}
ServiceList& ServiceList::GetInstance() {
static ServiceList instance;
return instance;
}
void ServiceList::AddService(std::unique_ptr<Service> service) {
services_.emplace_back(std::move(service));
}
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) {
LOG(ERROR) << "exec called with too many supplementary group ids";
return nullptr;
}
if (command_arg >= args.size()) {
LOG(ERROR) << "exec called without command";
return nullptr;
}
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) {
LOG(ERROR) << "Unable to decode UID for '" << args[2] << "': " << uid.error();
return nullptr;
}
}
Result<gid_t> gid = 0;
std::vector<gid_t> supp_gids;
if (command_arg > 4) {
gid = DecodeUid(args[3]);
if (!gid) {
LOG(ERROR) << "Unable to decode GID for '" << args[3] << "': " << gid.error();
return nullptr;
}
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) {
LOG(ERROR) << "Unable to decode GID for '" << args[4 + i]
<< "': " << supp_gid.error();
return nullptr;
}
supp_gids.push_back(*supp_gid);
}
}
return std::make_unique<Service>(name, flags, *uid, *gid, supp_gids, namespace_flags, seclabel,
nullptr, str_args);
}
// Shutdown services in the opposite order that they were started.
const std::vector<Service*> ServiceList::services_in_shutdown_order() const {
std::vector<Service*> shutdown_services;
for (const auto& service : services_) {
if (service->start_order() > 0) shutdown_services.emplace_back(service.get());
}
std::sort(shutdown_services.begin(), shutdown_services.end(),
[](const auto& a, const auto& b) { return a->start_order() > b->start_order(); });
return shutdown_services;
}
void ServiceList::RemoveService(const Service& svc) {
auto svc_it = std::find_if(services_.begin(), services_.end(),
[&svc] (const std::unique_ptr<Service>& s) {
return svc.name() == s->name();
});
if (svc_it == services_.end()) {
return;
}
services_.erase(svc_it);
}
void ServiceList::DumpState() const {
for (const auto& s : services_) {
s->DumpState();
}
}
void ServiceList::MarkPostData() {
post_data_ = true;
}
bool ServiceList::IsPostData() {
return post_data_;
}
void ServiceList::MarkServicesUpdate() {
services_update_finished_ = true;
// start the delayed services
for (const auto& name : delayed_service_names_) {
Service* service = FindService(name);
if (service == nullptr) {
LOG(ERROR) << "delayed service '" << name << "' could not be found.";
continue;
}
if (auto result = service->Start(); !result) {
LOG(ERROR) << result.error_string();
}
}
delayed_service_names_.clear();
}
void ServiceList::DelayService(const Service& service) {
if (services_update_finished_) {
LOG(ERROR) << "Cannot delay the start of service '" << service.name()
<< "' because all services are already updated. Ignoring.";
return;
}
delayed_service_names_.emplace_back(service.name());
}
Result<Success> ServiceParser::ParseSection(std::vector<std::string>&& args,
const std::string& filename, int line) {
if (args.size() < 3) {
return Error() << "services must have a name and a program";
}
const std::string& name = args[1];
if (!IsValidName(name)) {
return Error() << "invalid service name '" << name << "'";
}
filename_ = filename;
Subcontext* restart_action_subcontext = nullptr;
if (subcontexts_) {
for (auto& subcontext : *subcontexts_) {
if (StartsWith(filename, subcontext.path_prefix())) {
restart_action_subcontext = &subcontext;
break;
}
}
}
std::vector<std::string> str_args(args.begin() + 2, args.end());
if (SelinuxGetVendorAndroidVersion() <= __ANDROID_API_P__) {
if (str_args[0] == "/sbin/watchdogd") {
str_args[0] = "/system/bin/watchdogd";
}
}
service_ = std::make_unique<Service>(name, restart_action_subcontext, str_args);
return Success();
}
Result<Success> ServiceParser::ParseLineSection(std::vector<std::string>&& args, int line) {
return service_ ? service_->ParseLine(std::move(args)) : Success();
}
Result<Success> ServiceParser::EndSection() {
if (service_) {
Service* old_service = service_list_->FindService(service_->name());
if (old_service) {
if (!service_->is_override()) {
return Error() << "ignored duplicate definition of service '" << service_->name()
<< "'";
}
if (StartsWith(filename_, "/apex/") && !old_service->is_updatable()) {
return Error() << "cannot update a non-updatable service '" << service_->name()
<< "' with a config in APEX";
}
service_list_->RemoveService(*old_service);
old_service = nullptr;
}
service_list_->AddService(std::move(service_));
}
return Success();
}
bool ServiceParser::IsValidName(const std::string& name) const {
// Property names can be any length, but may only contain certain characters.
// Property values can contain any characters, but may only be a certain length.
// (The latter restriction is needed because `start` and `stop` work by writing
// the service name to the "ctl.start" and "ctl.stop" properties.)
return IsLegalPropertyName("init.svc." + name) && name.size() <= PROP_VALUE_MAX;
}
} // namespace init
} // namespace android