Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 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/TypeWrappers.h> |
| 18 | |
Adam Lesinski | c8f71aa | 2017-02-08 07:03:50 -0800 | [diff] [blame] | 19 | #include <algorithm> |
| 20 | |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 21 | namespace android { |
| 22 | |
Adam Lesinski | c8f71aa | 2017-02-08 07:03:50 -0800 | [diff] [blame] | 23 | TypeVariant::TypeVariant(const ResTable_type* data) : data(data), mLength(dtohl(data->entryCount)) { |
| 24 | if (data->flags & ResTable_type::FLAG_SPARSE) { |
| 25 | const uint32_t entryCount = dtohl(data->entryCount); |
| 26 | const uintptr_t containerEnd = reinterpret_cast<uintptr_t>(data) + dtohl(data->header.size); |
| 27 | const uint32_t* const entryIndices = reinterpret_cast<const uint32_t*>( |
| 28 | reinterpret_cast<uintptr_t>(data) + dtohs(data->header.headerSize)); |
| 29 | if (reinterpret_cast<uintptr_t>(entryIndices) + (sizeof(uint32_t) * entryCount) |
| 30 | > containerEnd) { |
| 31 | ALOGE("Type's entry indices extend beyond its boundaries"); |
| 32 | mLength = 0; |
| 33 | } else { |
| 34 | mLength = ResTable_sparseTypeEntry{entryIndices[entryCount - 1]}.idx + 1; |
| 35 | } |
| 36 | } |
| 37 | } |
| 38 | |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 39 | TypeVariant::iterator& TypeVariant::iterator::operator++() { |
| 40 | mIndex++; |
Adam Lesinski | c8f71aa | 2017-02-08 07:03:50 -0800 | [diff] [blame] | 41 | if (mIndex > mTypeVariant->mLength) { |
| 42 | mIndex = mTypeVariant->mLength; |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 43 | } |
| 44 | return *this; |
| 45 | } |
| 46 | |
Adam Lesinski | c8f71aa | 2017-02-08 07:03:50 -0800 | [diff] [blame] | 47 | static bool keyCompare(uint32_t entry, uint16_t index) { |
| 48 | return dtohs(ResTable_sparseTypeEntry{entry}.idx) < index; |
| 49 | } |
| 50 | |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 51 | const ResTable_entry* TypeVariant::iterator::operator*() const { |
| 52 | const ResTable_type* type = mTypeVariant->data; |
Adam Lesinski | c8f71aa | 2017-02-08 07:03:50 -0800 | [diff] [blame] | 53 | if (mIndex >= mTypeVariant->mLength) { |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 54 | return NULL; |
| 55 | } |
| 56 | |
Adam Lesinski | c8f71aa | 2017-02-08 07:03:50 -0800 | [diff] [blame] | 57 | const uint32_t entryCount = dtohl(mTypeVariant->data->entryCount); |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 58 | const uintptr_t containerEnd = reinterpret_cast<uintptr_t>(type) |
| 59 | + dtohl(type->header.size); |
| 60 | const uint32_t* const entryIndices = reinterpret_cast<const uint32_t*>( |
| 61 | reinterpret_cast<uintptr_t>(type) + dtohs(type->header.headerSize)); |
| 62 | if (reinterpret_cast<uintptr_t>(entryIndices) + (sizeof(uint32_t) * entryCount) > containerEnd) { |
| 63 | ALOGE("Type's entry indices extend beyond its boundaries"); |
| 64 | return NULL; |
| 65 | } |
| 66 | |
Adam Lesinski | c8f71aa | 2017-02-08 07:03:50 -0800 | [diff] [blame] | 67 | uint32_t entryOffset; |
| 68 | if (type->flags & ResTable_type::FLAG_SPARSE) { |
| 69 | auto iter = std::lower_bound(entryIndices, entryIndices + entryCount, mIndex, keyCompare); |
| 70 | if (iter == entryIndices + entryCount |
| 71 | || dtohs(ResTable_sparseTypeEntry{*iter}.idx) != mIndex) { |
| 72 | return NULL; |
| 73 | } |
| 74 | |
| 75 | entryOffset = static_cast<uint32_t>(dtohs(ResTable_sparseTypeEntry{*iter}.offset)) * 4u; |
| 76 | } else { |
| 77 | entryOffset = dtohl(entryIndices[mIndex]); |
| 78 | } |
| 79 | |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 80 | if (entryOffset == ResTable_type::NO_ENTRY) { |
| 81 | return NULL; |
| 82 | } |
| 83 | |
| 84 | if ((entryOffset & 0x3) != 0) { |
Adam Lesinski | fb600d6 | 2014-06-18 12:56:28 -0700 | [diff] [blame] | 85 | ALOGE("Index %u points to entry with unaligned offset 0x%08x", mIndex, entryOffset); |
Adam Lesinski | f90f2f8d | 2014-06-06 14:27:00 -0700 | [diff] [blame] | 86 | return NULL; |
| 87 | } |
| 88 | |
| 89 | const ResTable_entry* entry = reinterpret_cast<const ResTable_entry*>( |
| 90 | reinterpret_cast<uintptr_t>(type) + dtohl(type->entriesStart) + entryOffset); |
| 91 | if (reinterpret_cast<uintptr_t>(entry) > containerEnd - sizeof(*entry)) { |
| 92 | ALOGE("Entry offset at index %u points outside the Type's boundaries", mIndex); |
| 93 | return NULL; |
| 94 | } else if (reinterpret_cast<uintptr_t>(entry) + dtohs(entry->size) > containerEnd) { |
| 95 | ALOGE("Entry at index %u extends beyond Type's boundaries", mIndex); |
| 96 | return NULL; |
| 97 | } else if (dtohs(entry->size) < sizeof(*entry)) { |
| 98 | ALOGE("Entry at index %u is too small (%u)", mIndex, dtohs(entry->size)); |
| 99 | return NULL; |
| 100 | } |
| 101 | return entry; |
| 102 | } |
| 103 | |
| 104 | } // namespace android |