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/*
* Copyright (C) 2021 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.
*/
#include <snapuserd/snapuserd_buffer.h>
#include <snapuserd/snapuserd_kernel.h>
namespace android {
namespace snapshot {
void BufferSink::Initialize(size_t size) {
buffer_size_ = size;
buffer_offset_ = 0;
buffer_ = std::make_unique<uint8_t[]>(size);
}
void* BufferSink::GetPayloadBuffer(size_t size) {
if ((buffer_size_ - buffer_offset_) < size) return nullptr;
char* buffer = reinterpret_cast<char*>(GetBufPtr());
struct dm_user_message* msg = (struct dm_user_message*)(&(buffer[0]));
return (char*)msg->payload.buf + buffer_offset_;
}
void* BufferSink::GetBuffer(size_t requested, size_t* actual) {
void* buf = GetPayloadBuffer(requested);
if (!buf) {
*actual = 0;
return nullptr;
}
*actual = requested;
return buf;
}
struct dm_user_header* BufferSink::GetHeaderPtr() {
if (!(sizeof(struct dm_user_header) <= buffer_size_)) {
return nullptr;
}
char* buf = reinterpret_cast<char*>(GetBufPtr());
struct dm_user_header* header = (struct dm_user_header*)(&(buf[0]));
return header;
}
void* BufferSink::GetPayloadBufPtr() {
char* buffer = reinterpret_cast<char*>(GetBufPtr());
struct dm_user_message* msg = reinterpret_cast<struct dm_user_message*>(&(buffer[0]));
return msg->payload.buf;
}
void XorSink::Initialize(BufferSink* sink, size_t size) {
bufsink_ = sink;
buffer_size_ = size;
returned_ = 0;
buffer_ = std::make_unique<uint8_t[]>(size);
}
void XorSink::Reset() {
returned_ = 0;
}
void* XorSink::GetBuffer(size_t requested, size_t* actual) {
if (requested > buffer_size_) {
*actual = buffer_size_;
} else {
*actual = requested;
}
return buffer_.get();
}
bool XorSink::ReturnData(void* buffer, size_t len) {
uint8_t* xor_data = reinterpret_cast<uint8_t*>(buffer);
uint8_t* buff = reinterpret_cast<uint8_t*>(bufsink_->GetPayloadBuffer(len + returned_));
if (buff == nullptr) {
return false;
}
for (size_t i = 0; i < len; i++) {
buff[returned_ + i] ^= xor_data[i];
}
returned_ += len;
return true;
}
} // namespace snapshot
} // namespace android