1 /*
2 * Copyright (C) 2021 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <snapuserd/snapuserd_buffer.h>
18 #include <snapuserd/snapuserd_kernel.h>
19
20 namespace android {
21 namespace snapshot {
22
Initialize(size_t size)23 void BufferSink::Initialize(size_t size) {
24 buffer_size_ = size;
25 buffer_offset_ = 0;
26 buffer_ = std::make_unique<uint8_t[]>(size);
27 }
28
GetPayloadBuffer(size_t size)29 void* BufferSink::GetPayloadBuffer(size_t size) {
30 if ((buffer_size_ - buffer_offset_) < size) return nullptr;
31
32 char* buffer = reinterpret_cast<char*>(GetBufPtr());
33 struct dm_user_message* msg = (struct dm_user_message*)(&(buffer[0]));
34 return (char*)msg->payload.buf + buffer_offset_;
35 }
36
GetBuffer(size_t requested,size_t * actual)37 void* BufferSink::GetBuffer(size_t requested, size_t* actual) {
38 void* buf = GetPayloadBuffer(requested);
39 if (!buf) {
40 *actual = 0;
41 return nullptr;
42 }
43 *actual = requested;
44 return buf;
45 }
46
GetHeaderPtr()47 struct dm_user_header* BufferSink::GetHeaderPtr() {
48 if (!(sizeof(struct dm_user_header) <= buffer_size_)) {
49 return nullptr;
50 }
51 char* buf = reinterpret_cast<char*>(GetBufPtr());
52 struct dm_user_header* header = (struct dm_user_header*)(&(buf[0]));
53 return header;
54 }
55
GetPayloadBufPtr()56 void* BufferSink::GetPayloadBufPtr() {
57 char* buffer = reinterpret_cast<char*>(GetBufPtr());
58 struct dm_user_message* msg = reinterpret_cast<struct dm_user_message*>(&(buffer[0]));
59 return msg->payload.buf;
60 }
61
Initialize(BufferSink * sink,size_t size)62 void XorSink::Initialize(BufferSink* sink, size_t size) {
63 bufsink_ = sink;
64 buffer_size_ = size;
65 returned_ = 0;
66 buffer_ = std::make_unique<uint8_t[]>(size);
67 }
68
Reset()69 void XorSink::Reset() {
70 returned_ = 0;
71 }
72
GetBuffer(size_t requested,size_t * actual)73 void* XorSink::GetBuffer(size_t requested, size_t* actual) {
74 if (requested > buffer_size_) {
75 *actual = buffer_size_;
76 } else {
77 *actual = requested;
78 }
79 return buffer_.get();
80 }
81
ReturnData(void * buffer,size_t len)82 bool XorSink::ReturnData(void* buffer, size_t len) {
83 uint8_t* xor_data = reinterpret_cast<uint8_t*>(buffer);
84 uint8_t* buff = reinterpret_cast<uint8_t*>(bufsink_->GetPayloadBuffer(len + returned_));
85 if (buff == nullptr) {
86 return false;
87 }
88 for (size_t i = 0; i < len; i++) {
89 buff[returned_ + i] ^= xor_data[i];
90 }
91 returned_ += len;
92 return true;
93 }
94
95 } // namespace snapshot
96 } // namespace android
97