platform_system_core/init/service.h
Tom Cherry 33838b1156 init: change kill order and fix error reporting in KillProcessGroup()
First kill the process group before killing the cgroup to catch
the hopeful case that killing the cgroup becomes a no-op as all of its
processes have already been killed.

Do not report an error if kill fails due to ESRCH, as this happens
often when reaping processes due to the order in which we call
waitpid() and kill().

Do not call killProcessGroup in libprocessgroup if we have already
successfully killed and removed a process group.

Bug: 36661364
Bug: 36701253
Bug: 37540956

Test: Reboot bullhead
Test: Start and stop services
Test: Init unit tests
Change-Id: I172acf0f8e00189f910f865f4635a7b1782fc7e3
2017-05-04 12:33:19 -07:00

239 lines
9.4 KiB
C++

/*
* 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.
*/
#ifndef _INIT_SERVICE_H
#define _INIT_SERVICE_H
#include <sys/types.h>
#include <memory>
#include <set>
#include <string>
#include <vector>
#include <android-base/chrono_utils.h>
#include <cutils/iosched_policy.h>
#include "action.h"
#include "capabilities.h"
#include "descriptors.h"
#include "init_parser.h"
#include "keyword_map.h"
#include "util.h"
#define SVC_DISABLED 0x001 // do not autostart with class
#define SVC_ONESHOT 0x002 // do not restart on exit
#define SVC_RUNNING 0x004 // currently active
#define SVC_RESTARTING 0x008 // waiting to restart
#define SVC_CONSOLE 0x010 // requires console
#define SVC_CRITICAL 0x020 // will reboot into recovery if keeps crashing
#define SVC_RESET 0x040 // Use when stopping a process,
// but not disabling so it can be restarted with its class.
#define SVC_RC_DISABLED 0x080 // Remember if the disabled flag was set in the rc script.
#define SVC_RESTART 0x100 // Use to safely restart (stop, wait, start) a service.
#define SVC_DISABLED_START 0x200 // A start was requested but it was disabled at the time.
#define SVC_EXEC 0x400 // This service was started by either 'exec' or 'exec_start' and stops
// init from processing more commands until it completes
#define SVC_SHUTDOWN_CRITICAL 0x800 // This service is critical for shutdown and
// should not be killed during shutdown
#define SVC_TEMPORARY 0x1000 // This service was started by 'exec' and should be removed from the
// service list once it is reaped.
#define NR_SVC_SUPP_GIDS 12 // twelve supplementary groups
class Action;
class ServiceManager;
struct ServiceEnvironmentInfo {
ServiceEnvironmentInfo();
ServiceEnvironmentInfo(const std::string& name, const std::string& value);
std::string name;
std::string value;
};
class Service {
public:
Service(const std::string& name, const std::vector<std::string>& args);
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);
bool IsRunning() { return (flags_ & SVC_RUNNING) != 0; }
bool ParseLine(const std::vector<std::string>& args, std::string* err);
bool ExecStart(std::unique_ptr<Timer>* exec_waiter);
bool Start();
bool StartIfNotDisabled();
bool Enable();
void Reset();
void Stop();
void Terminate();
void Restart();
void RestartIfNeeded(time_t* process_needs_restart_at);
void Reap();
void DumpState() const;
void SetShutdownCritical() { flags_ |= SVC_SHUTDOWN_CRITICAL; }
bool IsShutdownCritical() const { return (flags_ & SVC_SHUTDOWN_CRITICAL) != 0; }
const std::string& name() const { return name_; }
const std::set<std::string>& classnames() const { return classnames_; }
unsigned flags() const { return flags_; }
pid_t pid() const { return pid_; }
int crash_count() const { return crash_count_; }
uid_t uid() const { return uid_; }
gid_t gid() const { return gid_; }
unsigned namespace_flags() const { return namespace_flags_; }
const std::vector<gid_t>& supp_gids() const { return supp_gids_; }
const std::string& seclabel() const { return seclabel_; }
const std::vector<int>& keycodes() const { return keycodes_; }
int keychord_id() const { return keychord_id_; }
void set_keychord_id(int keychord_id) { keychord_id_ = keychord_id; }
IoSchedClass ioprio_class() const { return ioprio_class_; }
int ioprio_pri() const { return ioprio_pri_; }
int priority() const { return priority_; }
int oom_score_adjust() const { return oom_score_adjust_; }
bool process_cgroup_empty() const { return process_cgroup_empty_; }
const std::vector<std::string>& args() const { return args_; }
private:
using OptionParser = bool (Service::*) (const std::vector<std::string>& args,
std::string* err);
class OptionParserMap;
void NotifyStateChange(const std::string& new_state) const;
void StopOrReset(int how);
void ZapStdio() const;
void OpenConsole() const;
void KillProcessGroup(int signal);
void SetProcessAttributes();
bool ParseCapabilities(const std::vector<std::string>& args, std::string *err);
bool ParseClass(const std::vector<std::string>& args, std::string* err);
bool ParseConsole(const std::vector<std::string>& args, std::string* err);
bool ParseCritical(const std::vector<std::string>& args, std::string* err);
bool ParseDisabled(const std::vector<std::string>& args, std::string* err);
bool ParseGroup(const std::vector<std::string>& args, std::string* err);
bool ParsePriority(const std::vector<std::string>& args, std::string* err);
bool ParseIoprio(const std::vector<std::string>& args, std::string* err);
bool ParseKeycodes(const std::vector<std::string>& args, std::string* err);
bool ParseOneshot(const std::vector<std::string>& args, std::string* err);
bool ParseOnrestart(const std::vector<std::string>& args, std::string* err);
bool ParseOomScoreAdjust(const std::vector<std::string>& args, std::string* err);
bool ParseNamespace(const std::vector<std::string>& args, std::string* err);
bool ParseSeclabel(const std::vector<std::string>& args, std::string* err);
bool ParseSetenv(const std::vector<std::string>& args, std::string* err);
bool ParseSocket(const std::vector<std::string>& args, std::string* err);
bool ParseFile(const std::vector<std::string>& args, std::string* err);
bool ParseUser(const std::vector<std::string>& args, std::string* err);
bool ParseWritepid(const std::vector<std::string>& args, std::string* err);
template <typename T>
bool AddDescriptor(const std::vector<std::string>& args, std::string* err);
std::string name_;
std::set<std::string> classnames_;
std::string console_;
unsigned flags_;
pid_t pid_;
android::base::boot_clock::time_point time_started_; // time of last start
android::base::boot_clock::time_point time_crashed_; // first crash within inspection window
int crash_count_; // number of times crashed within window
uid_t uid_;
gid_t gid_;
std::vector<gid_t> supp_gids_;
CapSet capabilities_;
unsigned namespace_flags_;
std::string seclabel_;
std::vector<std::unique_ptr<DescriptorInfo>> descriptors_;
std::vector<ServiceEnvironmentInfo> envvars_;
Action onrestart_; // Commands to execute on restart.
std::vector<std::string> writepid_files_;
// keycodes for triggering this service via /dev/keychord
std::vector<int> keycodes_;
int keychord_id_;
IoSchedClass ioprio_class_;
int ioprio_pri_;
int priority_;
int oom_score_adjust_;
bool process_cgroup_empty_ = false;
std::vector<std::string> args_;
};
class ServiceManager {
public:
static ServiceManager& GetInstance();
// Exposed for testing
ServiceManager();
void AddService(std::unique_ptr<Service> service);
Service* MakeExecOneshotService(const std::vector<std::string>& args);
bool Exec(const std::vector<std::string>& args);
bool ExecStart(const std::string& name);
bool IsWaitingForExec() const;
Service* FindServiceByName(const std::string& name) const;
Service* FindServiceByPid(pid_t pid) const;
Service* FindServiceByKeychord(int keychord_id) const;
void ForEachService(const std::function<void(Service*)>& callback) const;
void ForEachServiceInClass(const std::string& classname,
void (*func)(Service* svc)) const;
void ForEachServiceWithFlags(unsigned matchflags,
void (*func)(Service* svc)) const;
void ReapAnyOutstandingChildren();
void RemoveService(const Service& svc);
void DumpState() const;
private:
// Cleans up a child process that exited.
// Returns true iff a children was cleaned up.
bool ReapOneProcess();
static int exec_count_; // Every service needs a unique name.
std::unique_ptr<Timer> exec_waiter_;
std::vector<std::unique_ptr<Service>> services_;
};
class ServiceParser : public SectionParser {
public:
ServiceParser(ServiceManager* service_manager)
: service_manager_(service_manager), service_(nullptr) {}
bool ParseSection(std::vector<std::string>&& args, const std::string& filename, int line,
std::string* err) override;
bool ParseLineSection(std::vector<std::string>&& args, int line, std::string* err) override;
void EndSection() override;
private:
bool IsValidName(const std::string& name) const;
ServiceManager* service_manager_;
std::unique_ptr<Service> service_;
};
#endif