sandboxed-api/sandboxed_api/sandbox2/buffer.h

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// Copyright 2019 Google LLC
//
// 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 SANDBOXED_API_SANDBOX2_BUFFER_H_
#define SANDBOXED_API_SANDBOX2_BUFFER_H_
#include <cstddef>
#include <cstdint>
#include <memory>
#include "sandboxed_api/util/statusor.h"
namespace sandbox2 {
// Buffer provides a way for executor and sandboxee to share data.
// It is useful to share large buffers instead of communicating and copying.
// The executor must distrust the content of this buffer, like everything
// else that comes under control of the sandboxee.
class Buffer final {
public:
~Buffer();
Buffer(const Buffer&) = delete;
Buffer& operator=(const Buffer&) = delete;
// Creates a new Buffer that is backed by the specified file descriptor.
// The Buffer takes ownership of the descriptor and will close it when
// destroyed.
static sapi::StatusOr<std::unique_ptr<Buffer>> CreateFromFd(int fd);
// Creates a new Buffer of the specified size, backed by a temporary file that
// will be immediately deleted.
static sapi::StatusOr<std::unique_ptr<Buffer>> CreateWithSize(int64_t size);
// Returns a pointer to the buffer, which is read/write.
uint8_t* data() const { return buf_; }
// Gets the size of the buffer in bytes.
size_t size() const { return size_; }
// Gets the file descriptor backing the buffer.
int fd() const { return fd_; }
private:
Buffer() = default;
uint8_t* buf_ = nullptr;
int fd_ = -1;
size_t size_ = 0;
};
} // namespace sandbox2
#endif // SANDBOXED_API_SANDBOX2_BUFFER_H_