platform_system_core/init/service.h
Tom Cherry cb0f9bbc85 init: run vendor commands in a separate SELinux context
One of the major aspects of treble is the compartmentalization of system
and vendor components, however init leaves a huge gap here, as vendor
init scripts run in the same context as system init scripts and thus can
access and modify the same properties, files, etc as the system can.

This change is meant to close that gap.  It forks a separate 'subcontext'
init that runs in a different SELinux context with permissions that match
what vendors should have access to.  Commands get sent over a socket to
this 'subcontext' init that then runs them in this SELinux context and
returns the result.

Note that not all commands run in the subcontext; some commands such as
those dealing with services only make sense in the context of the main
init process.

Bug: 62875318
Test: init unit tests, boot bullhead, boot sailfish

Change-Id: Idf4a4ebf98842d27b8627f901f961ab9eb412aee
2017-09-29 13:06:26 -07:00

260 lines
10 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/resource.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 "keyword_map.h"
#include "parser.h"
#include "subcontext.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
namespace android {
namespace init {
class Service {
public:
Service(const std::string& name, Subcontext* subcontext_for_restart_commands,
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,
Subcontext* subcontext_for_restart_commands, const std::vector<std::string>& args);
static std::unique_ptr<Service> MakeTemporaryOneshotService(const std::vector<std::string>& args);
bool IsRunning() { return (flags_ & SVC_RUNNING) != 0; }
Result<Success> ParseLine(const std::vector<std::string>& args);
Result<Success> ExecStart();
Result<Success> Start();
Result<Success> StartIfNotDisabled();
Result<Success> Enable();
void Reset();
void Stop();
void Terminate();
void Restart();
void Reap();
void DumpState() const;
void SetShutdownCritical() { flags_ |= SVC_SHUTDOWN_CRITICAL; }
bool IsShutdownCritical() const { return (flags_ & SVC_SHUTDOWN_CRITICAL) != 0; }
void UnSetExec() {
is_exec_service_running_ = false;
flags_ &= ~SVC_EXEC;
}
static bool is_exec_service_running() { return is_exec_service_running_; }
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_; }
android::base::boot_clock::time_point time_started() const { return time_started_; }
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_; }
unsigned long start_order() const { return start_order_; }
const std::vector<std::string>& args() const { return args_; }
private:
using OptionParser = Result<Success> (Service::*)(const std::vector<std::string>& args);
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();
Result<Success> ParseCapabilities(const std::vector<std::string>& args);
Result<Success> ParseClass(const std::vector<std::string>& args);
Result<Success> ParseConsole(const std::vector<std::string>& args);
Result<Success> ParseCritical(const std::vector<std::string>& args);
Result<Success> ParseDisabled(const std::vector<std::string>& args);
Result<Success> ParseGroup(const std::vector<std::string>& args);
Result<Success> ParsePriority(const std::vector<std::string>& args);
Result<Success> ParseIoprio(const std::vector<std::string>& args);
Result<Success> ParseKeycodes(const std::vector<std::string>& args);
Result<Success> ParseOneshot(const std::vector<std::string>& args);
Result<Success> ParseOnrestart(const std::vector<std::string>& args);
Result<Success> ParseOomScoreAdjust(const std::vector<std::string>& args);
Result<Success> ParseMemcgLimitInBytes(const std::vector<std::string>& args);
Result<Success> ParseMemcgSoftLimitInBytes(const std::vector<std::string>& args);
Result<Success> ParseMemcgSwappiness(const std::vector<std::string>& args);
Result<Success> ParseNamespace(const std::vector<std::string>& args);
Result<Success> ParseProcessRlimit(const std::vector<std::string>& args);
Result<Success> ParseSeclabel(const std::vector<std::string>& args);
Result<Success> ParseSetenv(const std::vector<std::string>& args);
Result<Success> ParseShutdown(const std::vector<std::string>& args);
Result<Success> ParseSocket(const std::vector<std::string>& args);
Result<Success> ParseFile(const std::vector<std::string>& args);
Result<Success> ParseUser(const std::vector<std::string>& args);
Result<Success> ParseWritepid(const std::vector<std::string>& args);
template <typename T>
Result<Success> AddDescriptor(const std::vector<std::string>& args);
static unsigned long next_start_order_;
static bool is_exec_service_running_;
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<std::pair<std::string, std::string>> environment_vars_;
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_;
int swappiness_;
int soft_limit_in_bytes_;
int limit_in_bytes_;
bool process_cgroup_empty_ = false;
unsigned long start_order_;
std::vector<std::pair<int, rlimit>> rlimits_;
std::vector<std::string> args_;
};
class ServiceList {
public:
static ServiceList& GetInstance();
// Exposed for testing
ServiceList();
void AddService(std::unique_ptr<Service> service);
void RemoveService(const Service& svc);
template <typename T, typename F = decltype(&Service::name)>
Service* FindService(T value, F function = &Service::name) const {
auto svc = std::find_if(services_.begin(), services_.end(),
[&function, &value](const std::unique_ptr<Service>& s) {
return std::invoke(function, s) == value;
});
if (svc != services_.end()) {
return svc->get();
}
return nullptr;
}
void DumpState() const;
auto begin() const { return services_.begin(); }
auto end() const { return services_.end(); }
const std::vector<std::unique_ptr<Service>>& services() const { return services_; }
const std::vector<Service*> services_in_shutdown_order() const;
private:
std::vector<std::unique_ptr<Service>> services_;
};
class ServiceParser : public SectionParser {
public:
ServiceParser(ServiceList* service_list, std::vector<Subcontext>* subcontexts)
: service_list_(service_list), subcontexts_(subcontexts), service_(nullptr) {}
Result<Success> ParseSection(std::vector<std::string>&& args, const std::string& filename,
int line) override;
Result<Success> ParseLineSection(std::vector<std::string>&& args, int line) override;
void EndSection() override;
private:
bool IsValidName(const std::string& name) const;
ServiceList* service_list_;
std::vector<Subcontext>* subcontexts_;
std::unique_ptr<Service> service_;
};
} // namespace init
} // namespace android
#endif