platform_system_core/init/subcontext.h
Tom Cherry c49719fc5d init: always expand args in subcontext
Currently init expands properties in arguments only when those
commands are run in a subcontext.  This creates a hole where
properties that should not be accessible from a given subcontext of
init can be accessed when running a command in the main init
executable (for example `start`).

This change creates a callback in subcontext init that simply expands
and returns arguments back to the main init process, to ensure that
only those properties that a subcontext can access get expanded.

Bug: 62875318
Test: boot bullhead, new unit tests
Change-Id: I2850009e70da877c08e4cc83350c727b0ea98796
2018-01-12 10:35:26 -08:00

68 lines
1.9 KiB
C++

/*
* Copyright (C) 2017 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_SUBCONTEXT_H
#define _INIT_SUBCONTEXT_H
#include <signal.h>
#include <string>
#include <vector>
#include <android-base/unique_fd.h>
#include "builtins.h"
#include "system/core/init/subcontext.pb.h"
namespace android {
namespace init {
extern const std::string kInitContext;
extern const std::string kVendorContext;
class Subcontext {
public:
Subcontext(std::string path_prefix, std::string context)
: path_prefix_(std::move(path_prefix)), context_(std::move(context)), pid_(0) {
Fork();
}
Result<Success> Execute(const std::vector<std::string>& args);
Result<std::vector<std::string>> ExpandArgs(const std::vector<std::string>& args);
void Restart();
const std::string& path_prefix() const { return path_prefix_; }
const std::string& context() const { return context_; }
pid_t pid() const { return pid_; }
private:
void Fork();
Result<SubcontextReply> TransmitMessage(const SubcontextCommand& subcontext_command);
std::string path_prefix_;
std::string context_;
pid_t pid_;
android::base::unique_fd socket_;
};
int SubcontextMain(int argc, char** argv, const KeywordFunctionMap* function_map);
std::vector<Subcontext>* InitializeSubcontexts();
bool SubcontextChildReap(pid_t pid);
} // namespace init
} // namespace android
#endif