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// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef SANDBOX_MAC_SEATBELT_EXEC_H_
#define SANDBOX_MAC_SEATBELT_EXEC_H_
#include <string>
#include "base/compiler_specific.h" //nogncheck
#include "sandbox/mac/seatbelt.pb.h"
#include "sandbox/mac/seatbelt_export.h"
namespace sandbox {
namespace switches {
// This switch is set by the process running the SeatbeltExecClient. It
// specifies the FD number from which the SeatbeltExecServer should read the
// sandbox profile and parameters. This is prefixed with "--" and ends with "="
// for easier processing in C.
SEATBELT_EXPORT extern const char kSeatbeltClient[];
// This is the same as kSeatbeltClient without the prefix and suffix.
SEATBELT_EXPORT extern const char kSeatbeltClientName[];
} // namespace switches
// SeatbeltExecClient is used by the process that is launching another sandboxed
// process. The API allows the launcher process to supply a sandbox profile and
// parameters, which will be communicated to the sandboxed process over IPC.
class SEATBELT_EXPORT SeatbeltExecClient {
public:
SeatbeltExecClient();
~SeatbeltExecClient();
// The Set*Parameter functions return true if the parameter was successfully
// inserted. Check the return value, which indicates if the parameter was
// added successfully.
// Set a boolean parameter in the sandbox profile.
bool SetBooleanParameter(const std::string& key,
bool value) WARN_UNUSED_RESULT;
// Set a string parameter in the sandbox profile.
bool SetParameter(const std::string& key,
const std::string& value) WARN_UNUSED_RESULT;
// Set the actual sandbox profile, using the scheme-like SBPL.
void SetProfile(const std::string& policy);
// This returns the FD used for reading the sandbox profile in the child
// process. The FD should be mapped into the sandboxed child process.
// This must be called before SendProfile() or the returned FD will be -1.
// Callers should check that the returned FD is valid.
int GetReadFD();
// Sends the policy to the SeatbeltExecServer and returns success or failure.
bool SendProfile();
// Returns the underlying protobuf for testing purposes.
const mac::SandboxPolicy& GetPolicyForTesting() { return policy_; }
private:
// This writes a string (the serialized protobuf) to the |pipe_|.
bool WriteString(const std::string& str);
// This is the protobuf which contains the sandbox profile and parameters,
// and is serialized and sent to the other process.
mac::SandboxPolicy policy_;
// A file descriptor pair used for interprocess communication.
int pipe_[2];
};
// SeatbeltExecServer is used by the process that will be sandboxed to receive
// the profile and parameters from the launcher process. It can then initialize
// the profile, sandboxing the process.
class SEATBELT_EXPORT SeatbeltExecServer {
public:
// Creates a server instance with |server_fd| being the pipe returned from
// SeatbeltExecClient::GetReadFD(). To sandbox the process,
// InitializeSandbox() must be called.
explicit SeatbeltExecServer(int sandbox_fd);
~SeatbeltExecServer();
// CreateFromArguments parses the command line arguments for the
// kSeatbeltClient flag. If no flag is present, then |sandbox_required| is
// false and |server| is nullptr. If the flag is present, then
// |sandbox_required| is true. If the SeatbeltExecServer was successfully
// created then |server| will be the result instance, upon which
// InitializeSandbox() must be called. If initialization fails, then |server|
// will be nullptr.
struct CreateFromArgumentsResult {
CreateFromArgumentsResult();
CreateFromArgumentsResult(CreateFromArgumentsResult&&);
~CreateFromArgumentsResult();
bool sandbox_required = false;
std::unique_ptr<SeatbeltExecServer> server;
};
static CreateFromArgumentsResult
CreateFromArguments(const char* executable_path, int argc, char** argv);
// Reads the policy from the client, applies the profile, and returns whether
// or not the operation succeeds.
bool InitializeSandbox();
// Applies the given sandbox policy, and returns whether or not the operation
// succeeds.
bool ApplySandboxProfile(const mac::SandboxPolicy& sandbox_policy);
// Set a string parameter in the sandbox profile. This is present in the
// server because the process about to initialize a sandbox may need to add
// some extra parameters, such as the path to the executable or the current
// PID. This must be called before InitializeSandbox().
bool SetParameter(const std::string& key,
const std::string& value) WARN_UNUSED_RESULT;
private:
// Reads from the |fd_| and stores the data into a string. This does
// not append a NUL terminator as protobuf does not expect one.
bool ReadString(std::string* string);
// The file descriptor used to communicate with the launcher process.
int fd_;
// Extra parameters added by the server process.
std::map<std::string, std::string> extra_params_;
};
} // namespace sandbox
#endif // SANDBOX_MAC_SEATBELT_EXEC_H_