1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/*
* Copyright (C) 2017 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.
*/
#define ATRACE_TAG ATRACE_TAG_RESOURCES
#include "androidfw/Idmap.h"
#include "android-base/logging.h"
#include "android-base/stringprintf.h"
#include "utils/ByteOrder.h"
#include "utils/Trace.h"
#ifdef _WIN32
#ifdef ERROR
#undef ERROR
#endif
#endif
#include "androidfw/ResourceTypes.h"
using ::android::base::StringPrintf;
namespace android {
constexpr static inline bool is_valid_package_id(uint16_t id) {
return id != 0 && id <= 255;
}
constexpr static inline bool is_valid_type_id(uint16_t id) {
// Type IDs and package IDs have the same constraints in the IDMAP.
return is_valid_package_id(id);
}
bool LoadedIdmap::Lookup(const IdmapEntry_header* header, uint16_t input_entry_id,
uint16_t* output_entry_id) {
if (input_entry_id < dtohs(header->entry_id_offset)) {
// After applying the offset, the entry is not present.
return false;
}
input_entry_id -= dtohs(header->entry_id_offset);
if (input_entry_id >= dtohs(header->entry_count)) {
// The entry is not present.
return false;
}
uint32_t result = dtohl(header->entries[input_entry_id]);
if (result == 0xffffffffu) {
return false;
}
*output_entry_id = static_cast<uint16_t>(result);
return true;
}
static bool is_word_aligned(const void* data) {
return (reinterpret_cast<uintptr_t>(data) & 0x03) == 0;
}
static bool IsValidIdmapHeader(const StringPiece& data) {
if (!is_word_aligned(data.data())) {
LOG(ERROR) << "Idmap header is not word aligned.";
return false;
}
if (data.size() < sizeof(Idmap_header)) {
LOG(ERROR) << "Idmap header is too small.";
return false;
}
const Idmap_header* header = reinterpret_cast<const Idmap_header*>(data.data());
if (dtohl(header->magic) != kIdmapMagic) {
LOG(ERROR) << StringPrintf("Invalid Idmap file: bad magic value (was 0x%08x, expected 0x%08x)",
dtohl(header->magic), kIdmapMagic);
return false;
}
if (dtohl(header->version) != kIdmapCurrentVersion) {
// We are strict about versions because files with this format are auto-generated and don't need
// backwards compatibility.
LOG(ERROR) << StringPrintf("Version mismatch in Idmap (was 0x%08x, expected 0x%08x)",
dtohl(header->version), kIdmapCurrentVersion);
return false;
}
if (!is_valid_package_id(dtohs(header->target_package_id))) {
LOG(ERROR) << StringPrintf("Target package ID in Idmap is invalid: 0x%02x",
dtohs(header->target_package_id));
return false;
}
if (dtohs(header->type_count) > 255) {
LOG(ERROR) << StringPrintf("Idmap has too many type mappings (was %d, max 255)",
(int)dtohs(header->type_count));
return false;
}
return true;
}
LoadedIdmap::LoadedIdmap(const Idmap_header* header) : header_(header) {
size_t length = strnlen(reinterpret_cast<const char*>(header_->overlay_path),
arraysize(header_->overlay_path));
overlay_apk_path_.assign(reinterpret_cast<const char*>(header_->overlay_path), length);
}
std::unique_ptr<const LoadedIdmap> LoadedIdmap::Load(const StringPiece& idmap_data) {
ATRACE_CALL();
if (!IsValidIdmapHeader(idmap_data)) {
return {};
}
const Idmap_header* header = reinterpret_cast<const Idmap_header*>(idmap_data.data());
// Can't use make_unique because LoadedImpl constructor is private.
std::unique_ptr<LoadedIdmap> loaded_idmap = std::unique_ptr<LoadedIdmap>(new LoadedIdmap(header));
const uint8_t* data_ptr = reinterpret_cast<const uint8_t*>(idmap_data.data()) + sizeof(*header);
size_t data_size = idmap_data.size() - sizeof(*header);
size_t type_maps_encountered = 0u;
while (data_size >= sizeof(IdmapEntry_header)) {
if (!is_word_aligned(data_ptr)) {
LOG(ERROR) << "Type mapping in Idmap is not word aligned";
return {};
}
// Validate the type IDs.
const IdmapEntry_header* entry_header = reinterpret_cast<const IdmapEntry_header*>(data_ptr);
if (!is_valid_type_id(dtohs(entry_header->target_type_id)) || !is_valid_type_id(dtohs(entry_header->overlay_type_id))) {
LOG(ERROR) << StringPrintf("Invalid type map (0x%02x -> 0x%02x)",
dtohs(entry_header->target_type_id),
dtohs(entry_header->overlay_type_id));
return {};
}
// Make sure there is enough space for the entries declared in the header.
if ((data_size - sizeof(*entry_header)) / sizeof(uint32_t) <
static_cast<size_t>(dtohs(entry_header->entry_count))) {
LOG(ERROR) << StringPrintf("Idmap too small for the number of entries (%d)",
(int)dtohs(entry_header->entry_count));
return {};
}
// Only add a non-empty overlay.
if (dtohs(entry_header->entry_count != 0)) {
loaded_idmap->type_map_[static_cast<uint8_t>(dtohs(entry_header->overlay_type_id))] =
entry_header;
}
const size_t entry_size_bytes =
sizeof(*entry_header) + (dtohs(entry_header->entry_count) * sizeof(uint32_t));
data_ptr += entry_size_bytes;
data_size -= entry_size_bytes;
type_maps_encountered++;
}
// Verify that we parsed all the type maps.
if (type_maps_encountered != static_cast<size_t>(dtohs(header->type_count))) {
LOG(ERROR) << "Parsed " << type_maps_encountered << " type maps but expected "
<< (int)dtohs(header->type_count);
return {};
}
return std::move(loaded_idmap);
}
uint8_t LoadedIdmap::TargetPackageId() const {
return static_cast<uint8_t>(dtohs(header_->target_package_id));
}
const IdmapEntry_header* LoadedIdmap::GetEntryMapForType(uint8_t type_id) const {
auto iter = type_map_.find(type_id);
if (iter != type_map_.end()) {
return iter->second;
}
return nullptr;
}
} // namespace android
|
