diff options
Diffstat (limited to 'libs/androidfw/TypeWrappers.cpp')
-rw-r--r-- | libs/androidfw/TypeWrappers.cpp | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/libs/androidfw/TypeWrappers.cpp b/libs/androidfw/TypeWrappers.cpp new file mode 100644 index 0000000..8929b66 --- /dev/null +++ b/libs/androidfw/TypeWrappers.cpp @@ -0,0 +1,70 @@ +/* + * 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> + +namespace android { + +TypeVariant::iterator& TypeVariant::iterator::operator++() { + mIndex++; + if (mIndex > dtohl(mTypeVariant->data->entryCount)) { + mIndex = dtohl(mTypeVariant->data->entryCount); + } + return *this; +} + +const ResTable_entry* TypeVariant::iterator::operator*() const { + const ResTable_type* type = mTypeVariant->data; + const uint32_t entryCount = dtohl(type->entryCount); + if (mIndex >= entryCount) { + return NULL; + } + + 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; + } + + const uint32_t 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 %p", mIndex, (void*) 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 |