1 /* 2 * Copyright (C) 2015 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 "unflatten/ResChunkPullParser.h" 18 #include "util/Util.h" 19 20 #include <androidfw/ResourceTypes.h> 21 #include <cstddef> 22 23 namespace aapt { 24 25 using android::ResChunk_header; 26 27 ResChunkPullParser::Event ResChunkPullParser::next() { 28 if (!isGoodEvent(mEvent)) { 29 return mEvent; 30 } 31 32 if (mEvent == Event::StartDocument) { 33 mCurrentChunk = mData; 34 } else { 35 mCurrentChunk = (const ResChunk_header*) 36 (((const char*) mCurrentChunk) + util::deviceToHost32(mCurrentChunk->size)); 37 } 38 39 const std::ptrdiff_t diff = (const char*) mCurrentChunk - (const char*) mData; 40 assert(diff >= 0 && "diff is negative"); 41 const size_t offset = static_cast<const size_t>(diff); 42 43 if (offset == mLen) { 44 mCurrentChunk = nullptr; 45 return (mEvent = Event::EndDocument); 46 } else if (offset + sizeof(ResChunk_header) > mLen) { 47 mLastError = "chunk is past the end of the document"; 48 mCurrentChunk = nullptr; 49 return (mEvent = Event::BadDocument); 50 } 51 52 if (util::deviceToHost16(mCurrentChunk->headerSize) < sizeof(ResChunk_header)) { 53 mLastError = "chunk has too small header"; 54 mCurrentChunk = nullptr; 55 return (mEvent = Event::BadDocument); 56 } else if (util::deviceToHost32(mCurrentChunk->size) < 57 util::deviceToHost16(mCurrentChunk->headerSize)) { 58 mLastError = "chunk's total size is smaller than header"; 59 mCurrentChunk = nullptr; 60 return (mEvent = Event::BadDocument); 61 } else if (offset + util::deviceToHost32(mCurrentChunk->size) > mLen) { 62 mLastError = "chunk's data extends past the end of the document"; 63 mCurrentChunk = nullptr; 64 return (mEvent = Event::BadDocument); 65 } 66 return (mEvent = Event::Chunk); 67 } 68 69 } // namespace aapt 70
