| /* |
| * Copyright (C) 2014 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 <androidfw/TypeWrappers.h> |
| |
| #include <algorithm> |
| |
| namespace android { |
| |
| TypeVariant::TypeVariant(const ResTable_type* data) : data(data), mLength(dtohl(data->entryCount)) { |
| if (data->flags & ResTable_type::FLAG_SPARSE) { |
| const uint32_t entryCount = dtohl(data->entryCount); |
| const uintptr_t containerEnd = reinterpret_cast<uintptr_t>(data) + dtohl(data->header.size); |
| const uint32_t* const entryIndices = reinterpret_cast<const uint32_t*>( |
| reinterpret_cast<uintptr_t>(data) + dtohs(data->header.headerSize)); |
| if (reinterpret_cast<uintptr_t>(entryIndices) + (sizeof(uint32_t) * entryCount) |
| > containerEnd) { |
| ALOGE("Type's entry indices extend beyond its boundaries"); |
| mLength = 0; |
| } else { |
| mLength = ResTable_sparseTypeEntry{entryIndices[entryCount - 1]}.idx + 1; |
| } |
| } |
| } |
| |
| TypeVariant::iterator& TypeVariant::iterator::operator++() { |
| mIndex++; |
| if (mIndex > mTypeVariant->mLength) { |
| mIndex = mTypeVariant->mLength; |
| } |
| return *this; |
| } |
| |
| static bool keyCompare(uint32_t entry, uint16_t index) { |
| return dtohs(ResTable_sparseTypeEntry{entry}.idx) < index; |
| } |
| |
| const ResTable_entry* TypeVariant::iterator::operator*() const { |
| const ResTable_type* type = mTypeVariant->data; |
| if (mIndex >= mTypeVariant->mLength) { |
| return NULL; |
| } |
| |
| const uint32_t entryCount = dtohl(mTypeVariant->data->entryCount); |
| const uintptr_t containerEnd = reinterpret_cast<uintptr_t>(type) |
| + dtohl(type->header.size); |
| const uint32_t* const entryIndices = reinterpret_cast<const uint32_t*>( |
| reinterpret_cast<uintptr_t>(type) + dtohs(type->header.headerSize)); |
| if (reinterpret_cast<uintptr_t>(entryIndices) + (sizeof(uint32_t) * entryCount) > containerEnd) { |
| ALOGE("Type's entry indices extend beyond its boundaries"); |
| return NULL; |
| } |
| |
| uint32_t entryOffset; |
| if (type->flags & ResTable_type::FLAG_SPARSE) { |
| auto iter = std::lower_bound(entryIndices, entryIndices + entryCount, mIndex, keyCompare); |
| if (iter == entryIndices + entryCount |
| || dtohs(ResTable_sparseTypeEntry{*iter}.idx) != mIndex) { |
| return NULL; |
| } |
| |
| entryOffset = static_cast<uint32_t>(dtohs(ResTable_sparseTypeEntry{*iter}.offset)) * 4u; |
| } else { |
| entryOffset = dtohl(entryIndices[mIndex]); |
| } |
| |
| if (entryOffset == ResTable_type::NO_ENTRY) { |
| return NULL; |
| } |
| |
| if ((entryOffset & 0x3) != 0) { |
| ALOGE("Index %u points to entry with unaligned offset 0x%08x", mIndex, entryOffset); |
| return NULL; |
| } |
| |
| const ResTable_entry* entry = reinterpret_cast<const ResTable_entry*>( |
| reinterpret_cast<uintptr_t>(type) + dtohl(type->entriesStart) + entryOffset); |
| if (reinterpret_cast<uintptr_t>(entry) > containerEnd - sizeof(*entry)) { |
| ALOGE("Entry offset at index %u points outside the Type's boundaries", mIndex); |
| return NULL; |
| } else if (reinterpret_cast<uintptr_t>(entry) + dtohs(entry->size) > containerEnd) { |
| ALOGE("Entry at index %u extends beyond Type's boundaries", mIndex); |
| return NULL; |
| } else if (dtohs(entry->size) < sizeof(*entry)) { |
| ALOGE("Entry at index %u is too small (%u)", mIndex, dtohs(entry->size)); |
| return NULL; |
| } |
| return entry; |
| } |
| |
| } // namespace android |