1 files changed, 443 insertions, 0 deletions
diff --git a/cmds/idmap2/libidmap2/Idmap.cpp b/cmds/idmap2/libidmap2/Idmap.cpp
new file mode 100644
index 000000000000..5a47e301b66c
--- /dev/null
+++ b/cmds/idmap2/libidmap2/Idmap.cpp
@@ -0,0 +1,443 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#include <algorithm>
+#include <iostream>
+#include <iterator>
+#include <limits>
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "android-base/macros.h"
+#include "android-base/stringprintf.h"
+#include "androidfw/AssetManager2.h"
+#include "utils/String16.h"
+#include "utils/String8.h"
+
+#include "idmap2/Idmap.h"
+#include "idmap2/ResourceUtils.h"
+#include "idmap2/ZipFile.h"
+
+namespace android {
+namespace idmap2 {
+
+#define EXTRACT_TYPE(resid) ((0x00ff0000 & (resid)) >> 16)
+
+#define EXTRACT_ENTRY(resid) (0x0000ffff & (resid))
+
+struct MatchingResources {
+  void Add(ResourceId target_resid, ResourceId overlay_resid) {
+    TypeId target_typeid = EXTRACT_TYPE(target_resid);
+    if (map.find(target_typeid) == map.end()) {
+      map.emplace(target_typeid, std::set<std::pair<ResourceId, ResourceId>>());
+    }
+    map[target_typeid].insert(std::make_pair(target_resid, overlay_resid));
+  }
+
+  // target type id -> set { pair { overlay entry id, overlay entry id } }
+  std::map<TypeId, std::set<std::pair<ResourceId, ResourceId>>> map;
+};
+
+static bool WARN_UNUSED Read16(std::istream& stream, uint16_t* out) {
+  uint16_t value;
+  if (stream.read(reinterpret_cast<char*>(&value), sizeof(uint16_t))) {
+    *out = dtohl(value);
+    return true;
+  }
+  return false;
+}
+
+static bool WARN_UNUSED Read32(std::istream& stream, uint32_t* out) {
+  uint32_t value;
+  if (stream.read(reinterpret_cast<char*>(&value), sizeof(uint32_t))) {
+    *out = dtohl(value);
+    return true;
+  }
+  return false;
+}
+
+// a string is encoded as a kIdmapStringLength char array; the array is always null-terminated
+static bool WARN_UNUSED ReadString(std::istream& stream, char out[kIdmapStringLength]) {
+  char buf[kIdmapStringLength];
+  memset(buf, 0, sizeof(buf));
+  if (!stream.read(buf, sizeof(buf))) {
+    return false;
+  }
+  if (buf[sizeof(buf) - 1] != '\0') {
+    return false;
+  }
+  memcpy(out, buf, sizeof(buf));
+  return true;
+}
+
+static ResourceId NameToResid(const AssetManager2& am, const std::string& name) {
+  return am.GetResourceId(name);
+}
+
+// TODO(martenkongstad): scan for package name instead of assuming package at index 0
+//
+// idmap version 0x01 naively assumes that the package to use is always the first ResTable_package
+// in the resources.arsc blob. In most cases, there is only a single ResTable_package anyway, so
+// this assumption tends to work out. That said, the correct thing to do is to scan
+// resources.arsc for a package with a given name as read from the package manifest instead of
+// relying on a hard-coded index. This however requires storing the package name in the idmap
+// header, which in turn requires incrementing the idmap version. Because the initial version of
+// idmap2 is compatible with idmap, this will have to wait for now.
+static const LoadedPackage* GetPackageAtIndex0(const LoadedArsc& loaded_arsc) {
+  const std::vector<std::unique_ptr<const LoadedPackage>>& packages = loaded_arsc.GetPackages();
+  if (packages.empty()) {
+    return nullptr;
+  }
+  int id = packages[0]->GetPackageId();
+  return loaded_arsc.GetPackageById(id);
+}
+
+std::unique_ptr<const IdmapHeader> IdmapHeader::FromBinaryStream(std::istream& stream) {
+  std::unique_ptr<IdmapHeader> idmap_header(new IdmapHeader());
+
+  if (!Read32(stream, &idmap_header->magic_) || !Read32(stream, &idmap_header->version_) ||
+      !Read32(stream, &idmap_header->target_crc_) || !Read32(stream, &idmap_header->overlay_crc_) ||
+      !ReadString(stream, idmap_header->target_path_) ||
+      !ReadString(stream, idmap_header->overlay_path_)) {
+    return nullptr;
+  }
+
+  return std::move(idmap_header);
+}
+
+bool IdmapHeader::IsUpToDate(std::ostream& out_error) const {
+  if (magic_ != kIdmapMagic) {
+    out_error << base::StringPrintf("error: bad magic: actual 0x%08x, expected 0x%08x", magic_,
+                                    kIdmapMagic)
+              << std::endl;
+    return false;
+  }
+
+  if (version_ != kIdmapCurrentVersion) {
+    out_error << base::StringPrintf("error: bad version: actual 0x%08x, expected 0x%08x", version_,
+                                    kIdmapCurrentVersion)
+              << std::endl;
+    return false;
+  }
+
+  const std::unique_ptr<const ZipFile> target_zip = ZipFile::Open(target_path_);
+  if (!target_zip) {
+    out_error << "error: failed to open target " << target_path_ << std::endl;
+    return false;
+  }
+
+  bool status;
+  uint32_t target_crc;
+  std::tie(status, target_crc) = target_zip->Crc("resources.arsc");
+  if (!status) {
+    out_error << "error: failed to get target crc" << std::endl;
+    return false;
+  }
+
+  if (target_crc_ != target_crc) {
+    out_error << base::StringPrintf(
+                     "error: bad target crc: idmap version 0x%08x, file system version 0x%08x",
+                     target_crc_, target_crc)
+              << std::endl;
+    return false;
+  }
+
+  const std::unique_ptr<const ZipFile> overlay_zip = ZipFile::Open(overlay_path_);
+  if (!overlay_zip) {
+    out_error << "error: failed to open overlay " << overlay_path_ << std::endl;
+    return false;
+  }
+
+  uint32_t overlay_crc;
+  std::tie(status, overlay_crc) = overlay_zip->Crc("resources.arsc");
+  if (!status) {
+    out_error << "error: failed to get overlay crc" << std::endl;
+    return false;
+  }
+
+  if (overlay_crc_ != overlay_crc) {
+    out_error << base::StringPrintf(
+                     "error: bad overlay crc: idmap version 0x%08x, file system version 0x%08x",
+                     overlay_crc_, overlay_crc)
+              << std::endl;
+    return false;
+  }
+
+  return true;
+}
+
+std::unique_ptr<const IdmapData::Header> IdmapData::Header::FromBinaryStream(std::istream& stream) {
+  std::unique_ptr<IdmapData::Header> idmap_data_header(new IdmapData::Header());
+
+  uint16_t target_package_id16;
+  if (!Read16(stream, &target_package_id16) || !Read16(stream, &idmap_data_header->type_count_)) {
+    return nullptr;
+  }
+  idmap_data_header->target_package_id_ = target_package_id16;
+
+  return std::move(idmap_data_header);
+}
+
+std::unique_ptr<const IdmapData::TypeEntry> IdmapData::TypeEntry::FromBinaryStream(
+    std::istream& stream) {
+  std::unique_ptr<IdmapData::TypeEntry> data(new IdmapData::TypeEntry());
+
+  uint16_t target_type16, overlay_type16, entry_count;
+  if (!Read16(stream, &target_type16) || !Read16(stream, &overlay_type16) ||
+      !Read16(stream, &entry_count) || !Read16(stream, &data->entry_offset_)) {
+    return nullptr;
+  }
+  data->target_type_id_ = target_type16;
+  data->overlay_type_id_ = overlay_type16;
+  for (uint16_t i = 0; i < entry_count; i++) {
+    ResourceId resid;
+    if (!Read32(stream, &resid)) {
+      return nullptr;
+    }
+    data->entries_.push_back(resid);
+  }
+
+  return std::move(data);
+}
+
+std::unique_ptr<const IdmapData> IdmapData::FromBinaryStream(std::istream& stream) {
+  std::unique_ptr<IdmapData> data(new IdmapData());
+  data->header_ = IdmapData::Header::FromBinaryStream(stream);
+  if (!data->header_) {
+    return nullptr;
+  }
+  for (size_t type_count = 0; type_count < data->header_->GetTypeCount(); type_count++) {
+    std::unique_ptr<const TypeEntry> type = IdmapData::TypeEntry::FromBinaryStream(stream);
+    if (!type) {
+      return nullptr;
+    }
+    data->type_entries_.push_back(std::move(type));
+  }
+  return std::move(data);
+}
+
+std::string Idmap::CanonicalIdmapPathFor(const std::string& absolute_dir,
+                                         const std::string& absolute_apk_path) {
+  assert(absolute_dir.size() > 0 && absolute_dir[0] == "/");
+  assert(absolute_apk_path.size() > 0 && absolute_apk_path[0] == "/");
+  std::string copy(++absolute_apk_path.cbegin(), absolute_apk_path.cend());
+  replace(copy.begin(), copy.end(), '/', '@');
+  return absolute_dir + "/" + copy + "@idmap";
+}
+
+std::unique_ptr<const Idmap> Idmap::FromBinaryStream(std::istream& stream,
+                                                     std::ostream& out_error) {
+  std::unique_ptr<Idmap> idmap(new Idmap());
+
+  idmap->header_ = IdmapHeader::FromBinaryStream(stream);
+  if (!idmap->header_) {
+    out_error << "error: failed to parse idmap header" << std::endl;
+    return nullptr;
+  }
+
+  // idmap version 0x01 does not specify the number of data blocks that follow
+  // the idmap header; assume exactly one data block
+  for (int i = 0; i < 1; i++) {
+    std::unique_ptr<const IdmapData> data = IdmapData::FromBinaryStream(stream);
+    if (!data) {
+      out_error << "error: failed to parse data block " << i << std::endl;
+      return nullptr;
+    }
+    idmap->data_.push_back(std::move(data));
+  }
+
+  return std::move(idmap);
+}
+
+std::unique_ptr<const Idmap> Idmap::FromApkAssets(const std::string& target_apk_path,
+                                                  const ApkAssets& target_apk_assets,
+                                                  const std::string& overlay_apk_path,
+                                                  const ApkAssets& overlay_apk_assets,
+                                                  std::ostream& out_error) {
+  AssetManager2 target_asset_manager;
+  if (!target_asset_manager.SetApkAssets({&target_apk_assets}, true, false)) {
+    out_error << "error: failed to create target asset manager" << std::endl;
+    return nullptr;
+  }
+
+  AssetManager2 overlay_asset_manager;
+  if (!overlay_asset_manager.SetApkAssets({&overlay_apk_assets}, true, false)) {
+    out_error << "error: failed to create overlay asset manager" << std::endl;
+    return nullptr;
+  }
+
+  const LoadedArsc* target_arsc = target_apk_assets.GetLoadedArsc();
+  if (!target_arsc) {
+    out_error << "error: failed to load target resources.arsc" << std::endl;
+    return nullptr;
+  }
+
+  const LoadedArsc* overlay_arsc = overlay_apk_assets.GetLoadedArsc();
+  if (!overlay_arsc) {
+    out_error << "error: failed to load overlay resources.arsc" << std::endl;
+    return nullptr;
+  }
+
+  const LoadedPackage* target_pkg = GetPackageAtIndex0(*target_arsc);
+  if (!target_pkg) {
+    out_error << "error: failed to load target package from resources.arsc" << std::endl;
+    return nullptr;
+  }
+
+  const LoadedPackage* overlay_pkg = GetPackageAtIndex0(*overlay_arsc);
+  if (!overlay_pkg) {
+    out_error << "error: failed to load overlay package from resources.arsc" << std::endl;
+    return nullptr;
+  }
+
+  const std::unique_ptr<const ZipFile> target_zip = ZipFile::Open(target_apk_path);
+  if (!target_zip) {
+    out_error << "error: failed to open target as zip" << std::endl;
+    return nullptr;
+  }
+
+  const std::unique_ptr<const ZipFile> overlay_zip = ZipFile::Open(overlay_apk_path);
+  if (!overlay_zip) {
+    out_error << "error: failed to open overlay as zip" << std::endl;
+    return nullptr;
+  }
+
+  std::unique_ptr<IdmapHeader> header(new IdmapHeader());
+  header->magic_ = kIdmapMagic;
+  header->version_ = kIdmapCurrentVersion;
+  bool crc_status;
+  std::tie(crc_status, header->target_crc_) = target_zip->Crc("resources.arsc");
+  if (!crc_status) {
+    out_error << "error: failed to get zip crc for target" << std::endl;
+    return nullptr;
+  }
+  std::tie(crc_status, header->overlay_crc_) = overlay_zip->Crc("resources.arsc");
+  if (!crc_status) {
+    out_error << "error: failed to get zip crc for overlay" << std::endl;
+    return nullptr;
+  }
+
+  if (target_apk_path.size() > sizeof(header->target_path_)) {
+    out_error << "error: target apk path \"" << target_apk_path << "\" longer that maximum size "
+              << sizeof(header->target_path_) << std::endl;
+    return nullptr;
+  }
+  memset(header->target_path_, 0, sizeof(header->target_path_));
+  memcpy(header->target_path_, target_apk_path.data(), target_apk_path.size());
+
+  if (overlay_apk_path.size() > sizeof(header->overlay_path_)) {
+    out_error << "error: overlay apk path \"" << overlay_apk_path << "\" longer that maximum size "
+              << sizeof(header->overlay_path_) << std::endl;
+    return nullptr;
+  }
+  memset(header->overlay_path_, 0, sizeof(header->overlay_path_));
+  memcpy(header->overlay_path_, overlay_apk_path.data(), overlay_apk_path.size());
+
+  std::unique_ptr<Idmap> idmap(new Idmap());
+  idmap->header_ = std::move(header);
+
+  // find the resources that exist in both packages
+  MatchingResources matching_resources;
+  const auto end = overlay_pkg->end();
+  for (auto iter = overlay_pkg->begin(); iter != end; ++iter) {
+    const ResourceId overlay_resid = *iter;
+    bool lookup_ok;
+    std::string name;
+    std::tie(lookup_ok, name) = utils::ResToTypeEntryName(overlay_asset_manager, overlay_resid);
+    if (!lookup_ok) {
+      continue;
+    }
+    // prepend "<package>:" to turn name into "<package>:<type>/<name>"
+    name = base::StringPrintf("%s:%s", target_pkg->GetPackageName().c_str(), name.c_str());
+    const ResourceId target_resid = NameToResid(target_asset_manager, name);
+    if (target_resid == 0) {
+      continue;
+    }
+    matching_resources.Add(target_resid, overlay_resid);
+  }
+
+  // encode idmap data
+  std::unique_ptr<IdmapData> data(new IdmapData());
+  const auto types_end = matching_resources.map.cend();
+  for (auto ti = matching_resources.map.cbegin(); ti != types_end; ++ti) {
+    auto ei = ti->second.cbegin();
+    std::unique_ptr<IdmapData::TypeEntry> type(new IdmapData::TypeEntry());
+    type->target_type_id_ = EXTRACT_TYPE(ei->first);
+    type->overlay_type_id_ = EXTRACT_TYPE(ei->second);
+    type->entry_offset_ = EXTRACT_ENTRY(ei->first);
+    EntryId last_target_entry = kNoEntry;
+    for (; ei != ti->second.cend(); ++ei) {
+      if (last_target_entry != kNoEntry) {
+        int count = EXTRACT_ENTRY(ei->first) - last_target_entry - 1;
+        type->entries_.insert(type->entries_.end(), count, kNoEntry);
+      }
+      type->entries_.push_back(EXTRACT_ENTRY(ei->second));
+      last_target_entry = EXTRACT_ENTRY(ei->first);
+    }
+    data->type_entries_.push_back(std::move(type));
+  }
+
+  std::unique_ptr<IdmapData::Header> data_header(new IdmapData::Header());
+  data_header->target_package_id_ = target_pkg->GetPackageId();
+  data_header->type_count_ = data->type_entries_.size();
+  data->header_ = std::move(data_header);
+
+  idmap->data_.push_back(std::move(data));
+
+  return std::move(idmap);
+}
+
+void IdmapHeader::accept(Visitor* v) const {
+  assert(v != nullptr);
+  v->visit(*this);
+}
+
+void IdmapData::Header::accept(Visitor* v) const {
+  assert(v != nullptr);
+  v->visit(*this);
+}
+
+void IdmapData::TypeEntry::accept(Visitor* v) const {
+  assert(v != nullptr);
+  v->visit(*this);
+}
+
+void IdmapData::accept(Visitor* v) const {
+  assert(v != nullptr);
+  v->visit(*this);
+  header_->accept(v);
+  auto end = type_entries_.cend();
+  for (auto iter = type_entries_.cbegin(); iter != end; ++iter) {
+    (*iter)->accept(v);
+  }
+}
+
+void Idmap::accept(Visitor* v) const {
+  assert(v != nullptr);
+  v->visit(*this);
+  header_->accept(v);
+  auto end = data_.cend();
+  for (auto iter = data_.cbegin(); iter != end; ++iter) {
+    (*iter)->accept(v);
+  }
+}
+
+}  // namespace idmap2
+}  // namespace android