chrome/utility/safe_browsing/mac/udif.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_
   6 #define CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_
   7
   8 #include <CoreFoundation/CoreFoundation.h>
   9
  10 #include <string>
  11 #include <vector>
  12
  13 #include <sys/types.h>
  14
  15 #include "base/mac/scoped_cftyperef.h"
  16 #include "base/macros.h"
  17 #include "base/memory/scoped_ptr.h"
  18 #include "base/memory/scoped_vector.h"
  19
  20 namespace safe_browsing {
  21 namespace dmg {
  22
  23 class ReadStream;
  24 class UDIFBlock;
  25 struct UDIFBlockChunk;
  26
  27 // UDIFParser parses a Universal Disk Image Format file, allowing access to the
  28 // name, types, and data of the partitions held within the file. There is no
  29 // canonical documentation for UDIF, and not all disk images use UDIF (though
  30 // the majority do). Note that this implementation only handles UDIF and SPARSE
  31 // image types, not SPARSEBUNDLE.
  32 //
  33 // No guarantees are made about the position of ReadStream when using an
  34 // instance of this class.
  35 //
  36 // Note that this implementation relies on the UDIF blkx table to provide
  37 // accurate partition information. Otherwise, Apple Partition Map and
  38 // GUID would need to be parsed. See:
  39 //   - http://opensource.apple.com/source/IOStorageFamily/IOStorageFamily-182.1.1/IOApplePartitionScheme.h
  40 //   - http://opensource.apple.com/source/IOStorageFamily/IOStorageFamily-182.1.1/IOGUIDPartitionScheme.h
  41 //
  42 // The following references are useful for understanding the UDIF format:
  43 //   - http://newosxbook.com/DMG.html
  44 //   - http://www.macdisk.com/dmgen.php
  45 class UDIFParser {
  46  public:
  47   // Constructs an instance from a stream.
  48   explicit UDIFParser(ReadStream* stream);
  49   ~UDIFParser();
  50
  51   // Parses the UDIF file. This method must be called before any other method.
  52   // If this returns false, it is not legal to call any other methods.
  53   bool Parse();
  54
  55   // Returns the number of partitions in this UDIF image.
  56   size_t GetNumberOfPartitions();
  57
  58   // Returns the partition name for a given partition number, in the range of
  59   // [0,GetNumberOfPartitions()). This will include the number, name, and type
  60   // of partition. E.g., "disk image (Apple_HFS : 2)".
  61   std::string GetPartitionName(size_t part_number);
  62
  63   // Returns the partition type as a string for the given partition number.
  64   // E.g., "Apple_HFS" and "Apple_Free".
  65   std::string GetPartitionType(size_t part_number);
  66
  67   // Returns the size of the partition in bytes.
  68   size_t GetPartitionSize(size_t part_number);
  69
  70   // Returns a stream of the raw partition data for the given partition
  71   // number.
  72   scoped_ptr<ReadStream> GetPartitionReadStream(size_t part_number);
  73
  74  private:
  75   // Parses the blkx plist trailer structure.
  76   bool ParseBlkx();
  77
  78   // Reads the data pointed to by the block |chunk|, decompressing it as
  79   // necessary, into the out-buffer |decompressed_data|.
  80   bool ReadBlockChunk(const UDIFBlockChunk* chunk,
  81                       std::vector<uint8_t>* decompressed_data);
  82
  83   ReadStream* const stream_;  // The stream backing the UDIF image. Weak.
  84   std::vector<std::string> partition_names_;  // The names of all partitions.
  85   ScopedVector<const UDIFBlock> blocks_;  // All blocks in the UDIF image.
  86   uint16_t block_size_;  // The image's block size, in bytes.
  87
  88   DISALLOW_COPY_AND_ASSIGN(UDIFParser);
  89 };
  90
  91 }  // namespace dmg
  92 }  // namespace safe_browsing
  93
  94 #endif  // CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_