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 "file_magic.h" 18 19 #include <fcntl.h> 20 #include <sys/stat.h> 21 #include <sys/types.h> 22 23 #include "base/logging.h" 24 #include "dex_file.h" 25 #include "stringprintf.h" 26 27 namespace art { 28 29 ScopedFd OpenAndReadMagic(const char* filename, uint32_t* magic, std::string* error_msg) { 30 CHECK(magic != nullptr); 31 ScopedFd fd(open(filename, O_RDONLY, 0)); 32 if (fd.get() == -1) { 33 *error_msg = StringPrintf("Unable to open '%s' : %s", filename, strerror(errno)); 34 return ScopedFd(); 35 } 36 int n = TEMP_FAILURE_RETRY(read(fd.get(), magic, sizeof(*magic))); 37 if (n != sizeof(*magic)) { 38 *error_msg = StringPrintf("Failed to find magic in '%s'", filename); 39 return ScopedFd(); 40 } 41 if (lseek(fd.get(), 0, SEEK_SET) != 0) { 42 *error_msg = StringPrintf("Failed to seek to beginning of file '%s' : %s", filename, 43 strerror(errno)); 44 return ScopedFd(); 45 } 46 return fd; 47 } 48 49 bool IsZipMagic(uint32_t magic) { 50 return (('P' == ((magic >> 0) & 0xff)) && 51 ('K' == ((magic >> 8) & 0xff))); 52 } 53 54 bool IsDexMagic(uint32_t magic) { 55 return DexFile::IsMagicValid(reinterpret_cast<const uint8_t*>(&magic)); 56 } 57 58 } // namespace art 59
