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 "format/binary/ResChunkPullParser.h" 18 19 #include <inttypes.h> 20 #include <cstddef> 21 22 #include "android-base/logging.h" 23 #include "android-base/stringprintf.h" 24 #include "androidfw/ResourceTypes.h" 25 26 #include "util/Util.h" 27 28 namespace aapt { 29 30 using android::ResChunk_header; 31 using android::base::StringPrintf; 32 33 static std::string ChunkHeaderDump(const ResChunk_header* header) { 34 return StringPrintf("(type=%02" PRIx16 " header_size=%" PRIu16 " size=%" PRIu32 ")", 35 util::DeviceToHost16(header->type), util::DeviceToHost16(header->headerSize), 36 util::DeviceToHost32(header->size)); 37 } 38 39 ResChunkPullParser::Event ResChunkPullParser::Next() { 40 if (!IsGoodEvent(event_)) { 41 return event_; 42 } 43 44 if (event_ == Event::kStartDocument) { 45 current_chunk_ = data_; 46 } else { 47 current_chunk_ = (const ResChunk_header*)(((const char*)current_chunk_) + 48 util::DeviceToHost32(current_chunk_->size)); 49 } 50 51 const std::ptrdiff_t diff = (const char*)current_chunk_ - (const char*)data_; 52 CHECK(diff >= 0) << "diff is negative"; 53 const size_t offset = static_cast<const size_t>(diff); 54 55 if (offset == len_) { 56 current_chunk_ = nullptr; 57 return (event_ = Event::kEndDocument); 58 } else if (offset + sizeof(ResChunk_header) > len_) { 59 error_ = "chunk is past the end of the document"; 60 current_chunk_ = nullptr; 61 return (event_ = Event::kBadDocument); 62 } 63 64 if (util::DeviceToHost16(current_chunk_->headerSize) < sizeof(ResChunk_header)) { 65 error_ = "chunk has too small header"; 66 current_chunk_ = nullptr; 67 return (event_ = Event::kBadDocument); 68 } else if (util::DeviceToHost32(current_chunk_->size) < 69 util::DeviceToHost16(current_chunk_->headerSize)) { 70 error_ = "chunk's total size is smaller than header " + ChunkHeaderDump(current_chunk_); 71 current_chunk_ = nullptr; 72 return (event_ = Event::kBadDocument); 73 } else if (offset + util::DeviceToHost32(current_chunk_->size) > len_) { 74 error_ = "chunk's data extends past the end of the document " + ChunkHeaderDump(current_chunk_); 75 current_chunk_ = nullptr; 76 return (event_ = Event::kBadDocument); 77 } 78 return (event_ = Event::kChunk); 79 } 80 81 } // namespace aapt 82
