1 /*
2  * Copyright (C) 2018 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 "idmap2/BinaryStreamVisitor.h"
18 
19 #include <algorithm>
20 #include <cstring>
21 #include <string>
22 
23 #include "android-base/macros.h"
24 
25 namespace android::idmap2 {
26 
Write8(uint8_t value)27 void BinaryStreamVisitor::Write8(uint8_t value) {
28   stream_.write(reinterpret_cast<char*>(&value), sizeof(uint8_t));
29 }
30 
Write16(uint16_t value)31 void BinaryStreamVisitor::Write16(uint16_t value) {
32   uint16_t x = htodl(value);
33   stream_.write(reinterpret_cast<char*>(&x), sizeof(uint16_t));
34 }
35 
Write32(uint32_t value)36 void BinaryStreamVisitor::Write32(uint32_t value) {
37   uint32_t x = htodl(value);
38   stream_.write(reinterpret_cast<char*>(&x), sizeof(uint32_t));
39 }
40 
WriteString(const StringPiece & value)41 void BinaryStreamVisitor::WriteString(const StringPiece& value) {
42   // pad with null to nearest word boundary;
43   size_t padding_size = CalculatePadding(value.size());
44   Write32(value.size());
45   stream_.write(value.data(), value.size());
46   stream_.write("\0\0\0\0", padding_size);
47 }
48 
visit(const Idmap & idmap ATTRIBUTE_UNUSED)49 void BinaryStreamVisitor::visit(const Idmap& idmap ATTRIBUTE_UNUSED) {
50   // nothing to do
51 }
52 
visit(const IdmapHeader & header)53 void BinaryStreamVisitor::visit(const IdmapHeader& header) {
54   Write32(header.GetMagic());
55   Write32(header.GetVersion());
56   Write32(header.GetTargetCrc());
57   Write32(header.GetOverlayCrc());
58   Write32(header.GetFulfilledPolicies());
59   Write32(static_cast<uint8_t>(header.GetEnforceOverlayable()));
60   WriteString(header.GetTargetPath());
61   WriteString(header.GetOverlayPath());
62   WriteString(header.GetOverlayName());
63   WriteString(header.GetDebugInfo());
64 }
65 
visit(const IdmapData & data)66 void BinaryStreamVisitor::visit(const IdmapData& data) {
67   for (const auto& target_entry : data.GetTargetEntries()) {
68     Write32(target_entry.target_id);
69     Write32(target_entry.overlay_id);
70   }
71 
72   static constexpr uint16_t kValueSize = 8U;
73   for (const auto& target_entry : data.GetTargetInlineEntries()) {
74     Write32(target_entry.target_id);
75     Write16(kValueSize);
76     Write8(0U);  // padding
77     Write8(target_entry.value.data_type);
78     Write32(target_entry.value.data_value);
79   }
80 
81   for (const auto& overlay_entry : data.GetOverlayEntries()) {
82     Write32(overlay_entry.overlay_id);
83     Write32(overlay_entry.target_id);
84   }
85 
86   WriteString(data.GetStringPoolData());
87 }
88 
visit(const IdmapData::Header & header)89 void BinaryStreamVisitor::visit(const IdmapData::Header& header) {
90   Write32(header.GetTargetEntryCount());
91   Write32(header.GetTargetInlineEntryCount());
92   Write32(header.GetOverlayEntryCount());
93   Write32(header.GetStringPoolIndexOffset());
94 }
95 
96 }  // namespace android::idmap2
97