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android_system_core/init/service.cpp
Tom Cherry 70a5ed49ef init: move killing of process groups to libprocessgroup 
libprocessgroup kills the cgroup associated with a given pid and uid,
but not the POSIX process group associated with it.  This means that
to kill both, two of the same signals must be sent, which may cause
some issues.

This change kills all POSIX process groups whose group leaders are
found within a cgroup.  It only then kills processes in the cgroup
that are not part of the POSIX process groups that have been killed.

Bug: 37853905
Bug: 62418791
Test: Boot, kill zygote, reboot
Change-Id: Id1d96935745899b4c454c36c351ec16a0b1d3827
2017-06-07 13:20:21 -07:00

1176 lines
38 KiB
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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/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/system_properties.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 <processgroup/processgroup.h>
#include <selinux/selinux.h>
#include <system/thread_defs.h>
#include "init.h"
#include "property_service.h"
#include "util.h"
using android::base::boot_clock;
using android::base::ParseInt;
using android::base::StringPrintf;
using android::base::WriteStringToFile;
static std::string ComputeContextFromExecutable(std::string& service_name,
const std::string& service_path) {
std::string computed_context;
char* raw_con = nullptr;
char* raw_filecon = nullptr;
if (getcon(&raw_con) == -1) {
LOG(ERROR) << "could not get context while starting '" << service_name << "'";
return "";
}
std::unique_ptr<char> mycon(raw_con);
if (getfilecon(service_path.c_str(), &raw_filecon) == -1) {
LOG(ERROR) << "could not get file context while starting '" << service_name << "'";
return "";
}
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()) {
LOG(ERROR) << "service " << service_name << " does not have a SELinux domain defined";
return "";
}
if (rc < 0) {
LOG(ERROR) << "could not get context while starting '" << service_name << "'";
return "";
}
return computed_context;
}
static void SetUpPidNamespace(const std::string& service_name) {
constexpr unsigned int kSafeFlags = MS_NODEV | MS_NOEXEC | MS_NOSUID;
// It's OK to LOG(FATAL) in this function since it's running in the first
// child process.
if (mount("", "/proc", "proc", kSafeFlags | MS_REMOUNT, "") == -1) {
PLOG(FATAL) << "couldn't remount(/proc) for " << service_name;
}
if (prctl(PR_SET_NAME, service_name.c_str()) == -1) {
PLOG(FATAL) << "couldn't set name for " << service_name;
}
pid_t child_pid = fork();
if (child_pid == -1) {
PLOG(FATAL) << "couldn't fork init inside the PID namespace for " << service_name;
}
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));
}
}
static void ExpandArgs(const std::vector<std::string>& args, std::vector<char*>* strs) {
std::vector<std::string> expanded_args;
expanded_args.resize(args.size());
strs->push_back(const_cast<char*>(args[0].c_str()));
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] << "'";
}
strs->push_back(const_cast<char*>(expanded_args[i].c_str()));
}
strs->push_back(nullptr);
}
ServiceEnvironmentInfo::ServiceEnvironmentInfo() {
}
ServiceEnvironmentInfo::ServiceEnvironmentInfo(const std::string& name,
const std::string& value)
: name(name), value(value) {
}
Service::Service(const std::string& name, const std::vector<std::string>& args)
: name_(name),
classnames_({"default"}),
flags_(0),
pid_(0),
crash_count_(0),
uid_(0),
gid_(0),
namespace_flags_(0),
seclabel_(""),
onrestart_(false, "<Service '" + name + "' onrestart>", 0),
keychord_id_(0),
ioprio_class_(IoSchedClass_NONE),
ioprio_pri_(0),
priority_(0),
oom_score_adjust_(-1000),
args_(args) {
onrestart_.InitSingleTrigger("onrestart");
}
Service::Service(const std::string& name, unsigned flags, uid_t uid, gid_t gid,
const std::vector<gid_t>& supp_gids, const CapSet& capabilities,
unsigned namespace_flags, const std::string& seclabel,
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),
capabilities_(capabilities),
namespace_flags_(namespace_flags),
seclabel_(seclabel),
onrestart_(false, "<Service '" + name + "' onrestart>", 0),
keychord_id_(0),
ioprio_class_(IoSchedClass_NONE),
ioprio_pri_(0),
priority_(0),
oom_score_adjust_(-1000),
args_(args) {
onrestart_.InitSingleTrigger("onrestart");
}
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 = StringPrintf("init.svc.%s", name_.c_str());
property_set(prop_name.c_str(), new_state.c_str());
if (new_state == "running") {
uint64_t start_ns = time_started_.time_since_epoch().count();
property_set(StringPrintf("ro.boottime.%s", name_.c_str()).c_str(),
StringPrintf("%" PRIu64, start_ns).c_str());
}
}
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() {
// Keep capabilites on uid change.
if (capabilities_.any() && uid_) {
if (prctl(PR_SET_SECUREBITS, SECBIT_KEEP_CAPS | SECBIT_KEEP_CAPS_LOCKED) != 0) {
PLOG(FATAL) << "prtcl(PR_SET_KEEPCAPS) 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_.any()) {
if (!SetCapsForExec(capabilities_)) {
LOG(FATAL) << "cannot set capabilities for " << name_;
}
}
}
void Service::Reap() {
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));
if (flags_ & SVC_TEMPORARY) {
return;
}
pid_ = 0;
flags_ &= (~SVC_RUNNING);
// Oneshot processes go into the disabled state on exit,
// except when manually restarted.
if ((flags_ & SVC_ONESHOT) && !(flags_ & SVC_RESTART)) {
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, reboot into recovery.
boot_clock::time_point now = boot_clock::now();
if ((flags_ & SVC_CRITICAL) && !(flags_ & SVC_RESTART)) {
if (now < time_crashed_ + 4min) {
if (++crash_count_ > 4) {
LOG(ERROR) << "critical process '" << name_ << "' exited 4 times in 4 minutes";
panic();
}
} 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 '" << android::base::Join(classnames_, " ") << "'";
LOG(INFO) << " exec "<< android::base::Join(args_, " ");
std::for_each(descriptors_.begin(), descriptors_.end(),
[] (const auto& info) { LOG(INFO) << *info; });
}
bool Service::ParseCapabilities(const std::vector<std::string>& args, std::string* err) {
capabilities_ = 0;
if (!CapAmbientSupported()) {
*err = "capabilities requested but the kernel does not support ambient capabilities";
return false;
}
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) {
*err = StringPrintf("invalid capability '%s'", arg.c_str());
return false;
}
unsigned int cap = static_cast<unsigned int>(res); // |res| is >= 0.
if (cap > last_valid_cap) {
*err = StringPrintf("capability '%s' not supported by the kernel", arg.c_str());
return false;
}
capabilities_[cap] = true;
}
return true;
}
bool Service::ParseClass(const std::vector<std::string>& args, std::string* err) {
classnames_ = std::set<std::string>(args.begin() + 1, args.end());
return true;
}
bool Service::ParseConsole(const std::vector<std::string>& args, std::string* err) {
flags_ |= SVC_CONSOLE;
console_ = args.size() > 1 ? "/dev/" + args[1] : "";
return true;
}
bool Service::ParseCritical(const std::vector<std::string>& args, std::string* err) {
flags_ |= SVC_CRITICAL;
return true;
}
bool Service::ParseDisabled(const std::vector<std::string>& args, std::string* err) {
flags_ |= SVC_DISABLED;
flags_ |= SVC_RC_DISABLED;
return true;
}
bool Service::ParseGroup(const std::vector<std::string>& args, std::string* err) {
std::string decode_uid_err;
if (!DecodeUid(args[1], &gid_, &decode_uid_err)) {
*err = "Unable to find GID for '" + args[1] + "': " + decode_uid_err;
return false;
}
for (std::size_t n = 2; n < args.size(); n++) {
gid_t gid;
if (!DecodeUid(args[n], &gid, &decode_uid_err)) {
*err = "Unable to find GID for '" + args[n] + "': " + decode_uid_err;
return false;
}
supp_gids_.emplace_back(gid);
}
return true;
}
bool Service::ParsePriority(const std::vector<std::string>& args, std::string* err) {
priority_ = 0;
if (!ParseInt(args[1], &priority_,
static_cast<int>(ANDROID_PRIORITY_HIGHEST), // highest is negative
static_cast<int>(ANDROID_PRIORITY_LOWEST))) {
*err = StringPrintf("process priority value must be range %d - %d",
ANDROID_PRIORITY_HIGHEST, ANDROID_PRIORITY_LOWEST);
return false;
}
return true;
}
bool Service::ParseIoprio(const std::vector<std::string>& args, std::string* err) {
if (!ParseInt(args[2], &ioprio_pri_, 0, 7)) {
*err = "priority value must be range 0 - 7";
return false;
}
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 {
*err = "ioprio option usage: ioprio <rt|be|idle> <0-7>";
return false;
}
return true;
}
bool Service::ParseKeycodes(const std::vector<std::string>& args, std::string* err) {
for (std::size_t i = 1; i < args.size(); i++) {
int code;
if (ParseInt(args[i], &code)) {
keycodes_.emplace_back(code);
} else {
LOG(WARNING) << "ignoring invalid keycode: " << args[i];
}
}
return true;
}
bool Service::ParseOneshot(const std::vector<std::string>& args, std::string* err) {
flags_ |= SVC_ONESHOT;
return true;
}
bool Service::ParseOnrestart(const std::vector<std::string>& args, std::string* err) {
std::vector<std::string> str_args(args.begin() + 1, args.end());
int line = onrestart_.NumCommands() + 1;
onrestart_.AddCommand(str_args, line, err);
return true;
}
bool Service::ParseNamespace(const std::vector<std::string>& args, std::string* err) {
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 {
*err = "namespace must be 'pid' or 'mnt'";
return false;
}
}
return true;
}
bool Service::ParseOomScoreAdjust(const std::vector<std::string>& args, std::string* err) {
if (!ParseInt(args[1], &oom_score_adjust_, -1000, 1000)) {
*err = "oom_score_adjust value must be in range -1000 - +1000";
return false;
}
return true;
}
bool Service::ParseSeclabel(const std::vector<std::string>& args, std::string* err) {
seclabel_ = args[1];
return true;
}
bool Service::ParseSetenv(const std::vector<std::string>& args, std::string* err) {
envvars_.emplace_back(args[1], args[2]);
return true;
}
template <typename T>
bool Service::AddDescriptor(const std::vector<std::string>& args, std::string* err) {
int perm = args.size() > 3 ? std::strtoul(args[3].c_str(), 0, 8) : -1;
uid_t uid = 0;
gid_t gid = 0;
std::string context = args.size() > 6 ? args[6] : "";
std::string decode_uid_err;
if (args.size() > 4) {
if (!DecodeUid(args[4], &uid, &decode_uid_err)) {
*err = "Unable to find UID for '" + args[4] + "': " + decode_uid_err;
return false;
}
}
if (args.size() > 5) {
if (!DecodeUid(args[5], &gid, &decode_uid_err)) {
*err = "Unable to find GID for '" + args[5] + "': " + decode_uid_err;
return false;
}
}
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()) {
*err = "duplicate descriptor " + args[1] + " " + args[2];
return false;
}
descriptors_.emplace_back(std::move(descriptor));
return true;
}
// name type perm [ uid gid context ]
bool Service::ParseSocket(const std::vector<std::string>& args, std::string* err) {
if (!android::base::StartsWith(args[2], "dgram") &&
!android::base::StartsWith(args[2], "stream") &&
!android::base::StartsWith(args[2], "seqpacket")) {
*err = "socket type must be 'dgram', 'stream' or 'seqpacket'";
return false;
}
return AddDescriptor<SocketInfo>(args, err);
}
// name type perm [ uid gid context ]
bool Service::ParseFile(const std::vector<std::string>& args, std::string* err) {
if (args[2] != "r" && args[2] != "w" && args[2] != "rw") {
*err = "file type must be 'r', 'w' or 'rw'";
return false;
}
if ((args[1][0] != '/') || (args[1].find("../") != std::string::npos)) {
*err = "file name must not be relative";
return false;
}
return AddDescriptor<FileInfo>(args, err);
}
bool Service::ParseUser(const std::vector<std::string>& args, std::string* err) {
std::string decode_uid_err;
if (!DecodeUid(args[1], &uid_, &decode_uid_err)) {
*err = "Unable to find UID for '" + args[1] + "': " + decode_uid_err;
return false;
}
return true;
}
bool Service::ParseWritepid(const std::vector<std::string>& args, std::string* err) {
writepid_files_.assign(args.begin() + 1, args.end());
return true;
}
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",
{1, kMax, &Service::ParseCapabilities}},
{"class", {1, kMax, &Service::ParseClass}},
{"console", {0, 1, &Service::ParseConsole}},
{"critical", {0, 0, &Service::ParseCritical}},
{"disabled", {0, 0, &Service::ParseDisabled}},
{"group", {1, NR_SVC_SUPP_GIDS + 1, &Service::ParseGroup}},
{"ioprio", {2, 2, &Service::ParseIoprio}},
{"priority", {1, 1, &Service::ParsePriority}},
{"keycodes", {1, kMax, &Service::ParseKeycodes}},
{"oneshot", {0, 0, &Service::ParseOneshot}},
{"onrestart", {1, kMax, &Service::ParseOnrestart}},
{"oom_score_adjust",
{1, 1, &Service::ParseOomScoreAdjust}},
{"namespace", {1, 2, &Service::ParseNamespace}},
{"seclabel", {1, 1, &Service::ParseSeclabel}},
{"setenv", {2, 2, &Service::ParseSetenv}},
{"socket", {3, 6, &Service::ParseSocket}},
{"file", {2, 2, &Service::ParseFile}},
{"user", {1, 1, &Service::ParseUser}},
{"writepid", {1, kMax, &Service::ParseWritepid}},
};
// clang-format on
return option_parsers;
}
bool Service::ParseLine(const std::vector<std::string>& args, std::string* err) {
static const OptionParserMap parser_map;
auto parser = parser_map.FindFunction(args, err);
if (!parser) {
return false;
}
return (this->*parser)(args, err);
}
bool Service::ExecStart(std::unique_ptr<Timer>* exec_waiter) {
flags_ |= SVC_EXEC | SVC_ONESHOT;
exec_waiter->reset(new Timer);
if (!Start()) {
exec_waiter->reset();
return false;
}
return true;
}
bool Service::Start() {
// 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.
if (flags_ & SVC_RUNNING) {
return false;
}
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) {
PLOG(ERROR) << "service '" << name_ << "' couldn't open console '" << console_ << "'";
flags_ |= SVC_DISABLED;
return false;
}
close(console_fd);
}
struct stat sb;
if (stat(args_[0].c_str(), &sb) == -1) {
PLOG(ERROR) << "cannot find '" << args_[0] << "', disabling '" << name_ << "'";
flags_ |= SVC_DISABLED;
return false;
}
std::string scon;
if (!seclabel_.empty()) {
scon = seclabel_;
} else {
scon = ComputeContextFromExecutable(name_, args_[0]);
if (scon == "") {
return false;
}
}
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 (namespace_flags_ & CLONE_NEWPID) {
// This will fork again to run an init process inside the PID
// namespace.
SetUpPidNamespace(name_);
}
for (const auto& ei : envvars_) {
add_environment(ei.name.c_str(), ei.value.c_str());
}
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 /dev/cpuset/.
auto cpuset_predicate = [](const std::string& path) {
return android::base::StartsWith(path, "/dev/cpuset/");
};
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 = android::base::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("/dev/cpuset%stasks", default_cpuset.c_str()));
}
}
std::string pid_str = StringPrintf("%d", 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();
std::vector<char*> strs;
ExpandArgs(args_, &strs);
if (execve(strs[0], (char**) &strs[0], (char**) ENV) < 0) {
PLOG(ERROR) << "cannot execve('" << strs[0] << "')";
}
_exit(127);
}
if (pid < 0) {
PLOG(ERROR) << "failed to fork for '" << name_ << "'";
pid_ = 0;
return false;
}
if (oom_score_adjust_ != -1000) {
std::string oom_str = StringPrintf("%d", 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: " << strerror(errno);
}
}
time_started_ = boot_clock::now();
pid_ = pid;
flags_ |= SVC_RUNNING;
process_cgroup_empty_ = false;
errno = -createProcessGroup(uid_, pid_);
if (errno != 0) {
PLOG(ERROR) << "createProcessGroup(" << uid_ << ", " << pid_ << ") failed for service '"
<< name_ << "'";
}
if ((flags_ & SVC_EXEC) != 0) {
LOG(INFO) << android::base::StringPrintf(
"SVC_EXEC pid %d (uid %d gid %d+%zu context %s) started; waiting...", pid_, uid_, gid_,
supp_gids_.size(), !seclabel_.empty() ? seclabel_.c_str() : "default");
}
NotifyStateChange("running");
return true;
}
bool Service::StartIfNotDisabled() {
if (!(flags_ & SVC_DISABLED)) {
return Start();
} else {
flags_ |= SVC_DISABLED_START;
}
return true;
}
bool Service::Enable() {
flags_ &= ~(SVC_DISABLED | SVC_RC_DISABLED);
if (flags_ & SVC_DISABLED_START) {
return Start();
}
return true;
}
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::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. */
Start();
} /* else: Service is restarting anyways. */
}
void Service::RestartIfNeeded(time_t* process_needs_restart_at) {
boot_clock::time_point now = boot_clock::now();
boot_clock::time_point next_start = time_started_ + 5s;
if (now > next_start) {
flags_ &= (~SVC_RESTARTING);
Start();
return;
}
time_t next_start_time_t = time(nullptr) +
time_t(std::chrono::duration_cast<std::chrono::seconds>(next_start - now).count());
if (next_start_time_t < *process_needs_restart_at || *process_needs_restart_at == 0) {
*process_needs_restart_at = next_start_time_t;
}
}
// 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;
}
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);
}
int ServiceManager::exec_count_ = 0;
ServiceManager::ServiceManager() {
}
ServiceManager& ServiceManager::GetInstance() {
static ServiceManager instance;
return instance;
}
void ServiceManager::AddService(std::unique_ptr<Service> service) {
services_.emplace_back(std::move(service));
}
bool ServiceManager::Exec(const std::vector<std::string>& args) {
Service* svc = MakeExecOneshotService(args);
if (!svc) {
LOG(ERROR) << "Could not create exec service";
return false;
}
if (!svc->ExecStart(&exec_waiter_)) {
LOG(ERROR) << "Could not start exec service";
ServiceManager::GetInstance().RemoveService(*svc);
return false;
}
return true;
}
bool ServiceManager::ExecStart(const std::string& name) {
Service* svc = FindServiceByName(name);
if (!svc) {
LOG(ERROR) << "ExecStart(" << name << "): Service not found";
return false;
}
if (!svc->ExecStart(&exec_waiter_)) {
LOG(ERROR) << "ExecStart(" << name << "): Could not start Service";
return false;
}
return true;
}
bool ServiceManager::IsWaitingForExec() const { return exec_waiter_ != nullptr; }
Service* ServiceManager::MakeExecOneshotService(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());
exec_count_++;
std::string name =
"exec " + std::to_string(exec_count_) + " (" + android::base::Join(str_args, " ") + ")";
unsigned flags = SVC_EXEC | SVC_ONESHOT | SVC_TEMPORARY;
CapSet no_capabilities;
unsigned namespace_flags = 0;
std::string seclabel = "";
if (command_arg > 2 && args[1] != "-") {
seclabel = args[1];
}
uid_t uid = 0;
if (command_arg > 3) {
std::string decode_uid_err;
if (!DecodeUid(args[2], &uid, &decode_uid_err)) {
LOG(ERROR) << "Unable to find UID for '" << args[2] << "': " << decode_uid_err;
return nullptr;
}
}
gid_t gid = 0;
std::vector<gid_t> supp_gids;
if (command_arg > 4) {
std::string decode_uid_err;
if (!DecodeUid(args[3], &gid, &decode_uid_err)) {
LOG(ERROR) << "Unable to find GID for '" << args[3] << "': " << decode_uid_err;
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) {
gid_t supp_gid;
if (!DecodeUid(args[4 + i], &supp_gid, &decode_uid_err)) {
LOG(ERROR) << "Unable to find UID for '" << args[4 + i] << "': " << decode_uid_err;
return nullptr;
}
supp_gids.push_back(supp_gid);
}
}
auto svc_p = std::make_unique<Service>(name, flags, uid, gid, supp_gids, no_capabilities,
namespace_flags, seclabel, str_args);
Service* svc = svc_p.get();
services_.emplace_back(std::move(svc_p));
return svc;
}
Service* ServiceManager::FindServiceByName(const std::string& name) const {
auto svc = std::find_if(services_.begin(), services_.end(),
[&name] (const std::unique_ptr<Service>& s) {
return name == s->name();
});
if (svc != services_.end()) {
return svc->get();
}
return nullptr;
}
Service* ServiceManager::FindServiceByPid(pid_t pid) const {
auto svc = std::find_if(services_.begin(), services_.end(),
[&pid] (const std::unique_ptr<Service>& s) {
return s->pid() == pid;
});
if (svc != services_.end()) {
return svc->get();
}
return nullptr;
}
Service* ServiceManager::FindServiceByKeychord(int keychord_id) const {
auto svc = std::find_if(services_.begin(), services_.end(),
[&keychord_id] (const std::unique_ptr<Service>& s) {
return s->keychord_id() == keychord_id;
});
if (svc != services_.end()) {
return svc->get();
}
return nullptr;
}
void ServiceManager::ForEachService(const std::function<void(Service*)>& callback) const {
for (const auto& s : services_) {
callback(s.get());
}
}
void ServiceManager::ForEachServiceInClass(const std::string& classname,
void (*func)(Service* svc)) const {
for (const auto& s : services_) {
if (s->classnames().find(classname) != s->classnames().end()) {
func(s.get());
}
}
}
void ServiceManager::ForEachServiceWithFlags(unsigned matchflags,
void (*func)(Service* svc)) const {
for (const auto& s : services_) {
if (s->flags() & matchflags) {
func(s.get());
}
}
}
void ServiceManager::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 ServiceManager::DumpState() const {
for (const auto& s : services_) {
s->DumpState();
}
}
bool ServiceManager::ReapOneProcess() {
int status;
pid_t pid = TEMP_FAILURE_RETRY(waitpid(-1, &status, WNOHANG));
if (pid == 0) {
return false;
} else if (pid == -1) {
PLOG(ERROR) << "waitpid failed";
return false;
}
Service* svc = FindServiceByPid(pid);
std::string name;
std::string wait_string;
if (svc) {
name = android::base::StringPrintf("Service '%s' (pid %d)",
svc->name().c_str(), pid);
if (svc->flags() & SVC_EXEC) {
wait_string =
android::base::StringPrintf(" waiting took %f seconds", exec_waiter_->duration_s());
}
} else {
name = android::base::StringPrintf("Untracked pid %d", pid);
}
if (WIFEXITED(status)) {
LOG(INFO) << name << " exited with status " << WEXITSTATUS(status) << wait_string;
} else if (WIFSIGNALED(status)) {
LOG(INFO) << name << " killed by signal " << WTERMSIG(status) << wait_string;
} else if (WIFSTOPPED(status)) {
LOG(INFO) << name << " stopped by signal " << WSTOPSIG(status) << wait_string;
} else {
LOG(INFO) << name << " state changed" << wait_string;
}
if (!svc) {
return true;
}
svc->Reap();
if (svc->flags() & SVC_EXEC) {
exec_waiter_.reset();
}
if (svc->flags() & SVC_TEMPORARY) {
RemoveService(*svc);
}
return true;
}
void ServiceManager::ReapAnyOutstandingChildren() {
while (ReapOneProcess()) {
}
}
bool ServiceParser::ParseSection(std::vector<std::string>&& args, const std::string& filename,
int line, std::string* err) {
if (args.size() < 3) {
*err = "services must have a name and a program";
return false;
}
const std::string& name = args[1];
if (!IsValidName(name)) {
*err = StringPrintf("invalid service name '%s'", name.c_str());
return false;
}
Service* old_service = service_manager_->FindServiceByName(name);
if (old_service) {
*err = "ignored duplicate definition of service '" + name + "'";
return false;
}
std::vector<std::string> str_args(args.begin() + 2, args.end());
service_ = std::make_unique<Service>(name, str_args);
return true;
}
bool ServiceParser::ParseLineSection(std::vector<std::string>&& args, int line, std::string* err) {
return service_ ? service_->ParseLine(std::move(args), err) : false;
}
void ServiceParser::EndSection() {
if (service_) {
service_manager_->AddService(std::move(service_));
}
}
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 is_legal_property_name("init.svc." + name) && name.size() <= PROP_VALUE_MAX;
}
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