ApkAssets.cpp revision ec7f06cc372a7298c85bf96cb4133d7dc8807419 
1/*
2 * Copyright (C) 2016 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#define ATRACE_TAG ATRACE_TAG_RESOURCES
18
19#include "androidfw/ApkAssets.h"
20
21#include <algorithm>
22
23#include "android-base/errors.h"
24#include "android-base/file.h"
25#include "android-base/logging.h"
26#include "android-base/unique_fd.h"
27#include "android-base/utf8.h"
28#include "utils/Compat.h"
29#include "utils/FileMap.h"
30#include "utils/Trace.h"
31#include "ziparchive/zip_archive.h"
32
33#include "androidfw/Asset.h"
34#include "androidfw/Idmap.h"
35#include "androidfw/ResourceTypes.h"
36#include "androidfw/Util.h"
37
38namespace android {
39
40using base::SystemErrorCodeToString;
41using base::unique_fd;
42
43static const std::string kResourcesArsc("resources.arsc");
44
45ApkAssets::ApkAssets(void* unmanaged_handle, const std::string& path)
46    : zip_handle_(unmanaged_handle, ::CloseArchive), path_(path) {
47}
48
49std::unique_ptr<const ApkAssets> ApkAssets::Load(const std::string& path, bool system) {
50  return LoadImpl({} /*fd*/, path, nullptr, nullptr, system, false /*load_as_shared_library*/);
51}
52
53std::unique_ptr<const ApkAssets> ApkAssets::LoadAsSharedLibrary(const std::string& path,
54                                                                bool system) {
55  return LoadImpl({} /*fd*/, path, nullptr, nullptr, system, true /*load_as_shared_library*/);
56}
57
58std::unique_ptr<const ApkAssets> ApkAssets::LoadOverlay(const std::string& idmap_path,
59                                                        bool system) {
60  std::unique_ptr<Asset> idmap_asset = CreateAssetFromFile(idmap_path);
61  if (idmap_asset == nullptr) {
62    return {};
63  }
64
65  const StringPiece idmap_data(
66      reinterpret_cast<const char*>(idmap_asset->getBuffer(true /*wordAligned*/)),
67      static_cast<size_t>(idmap_asset->getLength()));
68  std::unique_ptr<const LoadedIdmap> loaded_idmap = LoadedIdmap::Load(idmap_data);
69  if (loaded_idmap == nullptr) {
70    LOG(ERROR) << "failed to load IDMAP " << idmap_path;
71    return {};
72  }
73  return LoadImpl({} /*fd*/, loaded_idmap->OverlayApkPath(), std::move(idmap_asset),
74                  std::move(loaded_idmap), system, false /*load_as_shared_library*/);
75}
76
77std::unique_ptr<const ApkAssets> ApkAssets::LoadFromFd(unique_fd fd,
78                                                       const std::string& friendly_name,
79                                                       bool system, bool force_shared_lib) {
80  return LoadImpl(std::move(fd), friendly_name, nullptr /*idmap_asset*/, nullptr /*loaded_idmap*/,
81                  system, force_shared_lib);
82}
83
84std::unique_ptr<Asset> ApkAssets::CreateAssetFromFile(const std::string& path) {
85  unique_fd fd(base::utf8::open(path.c_str(), O_RDONLY | O_BINARY | O_CLOEXEC));
86  if (fd == -1) {
87    LOG(ERROR) << "Failed to open file '" << path << "': " << SystemErrorCodeToString(errno);
88    return {};
89  }
90
91  const off64_t file_len = lseek64(fd, 0, SEEK_END);
92  if (file_len < 0) {
93    LOG(ERROR) << "Failed to get size of file '" << path << "': " << SystemErrorCodeToString(errno);
94    return {};
95  }
96
97  std::unique_ptr<FileMap> file_map = util::make_unique<FileMap>();
98  if (!file_map->create(path.c_str(), fd, 0, static_cast<size_t>(file_len), true /*readOnly*/)) {
99    LOG(ERROR) << "Failed to mmap file '" << path << "': " << SystemErrorCodeToString(errno);
100    return {};
101  }
102  return Asset::createFromUncompressedMap(std::move(file_map), Asset::AccessMode::ACCESS_RANDOM);
103}
104
105std::unique_ptr<const ApkAssets> ApkAssets::LoadImpl(
106    unique_fd fd, const std::string& path, std::unique_ptr<Asset> idmap_asset,
107    std::unique_ptr<const LoadedIdmap> loaded_idmap, bool system, bool load_as_shared_library) {
108  ATRACE_CALL();
109
110  ::ZipArchiveHandle unmanaged_handle;
111  int32_t result;
112  if (fd >= 0) {
113    result =
114        ::OpenArchiveFd(fd.release(), path.c_str(), &unmanaged_handle, true /*assume_ownership*/);
115  } else {
116    result = ::OpenArchive(path.c_str(), &unmanaged_handle);
117  }
118
119  if (result != 0) {
120    LOG(ERROR) << "Failed to open APK '" << path << "' " << ::ErrorCodeString(result);
121    return {};
122  }
123
124  // Wrap the handle in a unique_ptr so it gets automatically closed.
125  std::unique_ptr<ApkAssets> loaded_apk(new ApkAssets(unmanaged_handle, path));
126
127  // Find the resource table.
128  ::ZipString entry_name(kResourcesArsc.c_str());
129  ::ZipEntry entry;
130  result = ::FindEntry(loaded_apk->zip_handle_.get(), entry_name, &entry);
131  if (result != 0) {
132    // There is no resources.arsc, so create an empty LoadedArsc and return.
133    loaded_apk->loaded_arsc_ = LoadedArsc::CreateEmpty();
134    return std::move(loaded_apk);
135  }
136
137  if (entry.method == kCompressDeflated) {
138    LOG(WARNING) << kResourcesArsc << " in APK '" << path << "' is compressed.";
139  }
140
141  // Open the resource table via mmap unless it is compressed. This logic is taken care of by Open.
142  loaded_apk->resources_asset_ = loaded_apk->Open(kResourcesArsc, Asset::AccessMode::ACCESS_BUFFER);
143  if (loaded_apk->resources_asset_ == nullptr) {
144    LOG(ERROR) << "Failed to open '" << kResourcesArsc << "' in APK '" << path << "'.";
145    return {};
146  }
147
148  // Must retain ownership of the IDMAP Asset so that all pointers to its mmapped data remain valid.
149  loaded_apk->idmap_asset_ = std::move(idmap_asset);
150
151  const StringPiece data(
152      reinterpret_cast<const char*>(loaded_apk->resources_asset_->getBuffer(true /*wordAligned*/)),
153      loaded_apk->resources_asset_->getLength());
154  loaded_apk->loaded_arsc_ =
155      LoadedArsc::Load(data, loaded_idmap.get(), system, load_as_shared_library);
156  if (loaded_apk->loaded_arsc_ == nullptr) {
157    LOG(ERROR) << "Failed to load '" << kResourcesArsc << "' in APK '" << path << "'.";
158    return {};
159  }
160
161  // Need to force a move for mingw32.
162  return std::move(loaded_apk);
163}
164
165std::unique_ptr<Asset> ApkAssets::Open(const std::string& path, Asset::AccessMode mode) const {
166  ATRACE_CALL();
167  CHECK(zip_handle_ != nullptr);
168
169  ::ZipString name(path.c_str());
170  ::ZipEntry entry;
171  int32_t result = ::FindEntry(zip_handle_.get(), name, &entry);
172  if (result != 0) {
173    return {};
174  }
175
176  if (entry.method == kCompressDeflated) {
177    std::unique_ptr<FileMap> map = util::make_unique<FileMap>();
178    if (!map->create(path_.c_str(), ::GetFileDescriptor(zip_handle_.get()), entry.offset,
179                     entry.compressed_length, true /*readOnly*/)) {
180      LOG(ERROR) << "Failed to mmap file '" << path << "' in APK '" << path_ << "'";
181      return {};
182    }
183
184    std::unique_ptr<Asset> asset =
185        Asset::createFromCompressedMap(std::move(map), entry.uncompressed_length, mode);
186    if (asset == nullptr) {
187      LOG(ERROR) << "Failed to decompress '" << path << "'.";
188      return {};
189    }
190    return asset;
191  } else {
192    std::unique_ptr<FileMap> map = util::make_unique<FileMap>();
193    if (!map->create(path_.c_str(), ::GetFileDescriptor(zip_handle_.get()), entry.offset,
194                     entry.uncompressed_length, true /*readOnly*/)) {
195      LOG(ERROR) << "Failed to mmap file '" << path << "' in APK '" << path_ << "'";
196      return {};
197    }
198
199    std::unique_ptr<Asset> asset = Asset::createFromUncompressedMap(std::move(map), mode);
200    if (asset == nullptr) {
201      LOG(ERROR) << "Failed to mmap file '" << path << "' in APK '" << path_ << "'";
202      return {};
203    }
204    return asset;
205  }
206}
207
208bool ApkAssets::ForEachFile(const std::string& root_path,
209                            const std::function<void(const StringPiece&, FileType)>& f) const {
210  CHECK(zip_handle_ != nullptr);
211
212  std::string root_path_full = root_path;
213  if (root_path_full.back() != '/') {
214    root_path_full += '/';
215  }
216
217  ::ZipString prefix(root_path_full.c_str());
218  void* cookie;
219  if (::StartIteration(zip_handle_.get(), &cookie, &prefix, nullptr) != 0) {
220    return false;
221  }
222
223  ::ZipString name;
224  ::ZipEntry entry;
225
226  // We need to hold back directories because many paths will contain them and we want to only
227  // surface one.
228  std::set<std::string> dirs;
229
230  int32_t result;
231  while ((result = ::Next(cookie, &entry, &name)) == 0) {
232    StringPiece full_file_path(reinterpret_cast<const char*>(name.name), name.name_length);
233    StringPiece leaf_file_path = full_file_path.substr(root_path_full.size());
234    auto iter = std::find(leaf_file_path.begin(), leaf_file_path.end(), '/');
235    if (iter != leaf_file_path.end()) {
236      dirs.insert(
237          leaf_file_path.substr(0, std::distance(leaf_file_path.begin(), iter)).to_string());
238    } else if (!leaf_file_path.empty()) {
239      f(leaf_file_path, kFileTypeRegular);
240    }
241  }
242  ::EndIteration(cookie);
243
244  // Now present the unique directories.
245  for (const std::string& dir : dirs) {
246    f(dir, kFileTypeDirectory);
247  }
248
249  // -1 is end of iteration, anything else is an error.
250  return result == -1;
251}
252
253}  // namespace android
254