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