1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_UTILITY_SAFE_BROWSING_MAC_HFS_H_
#define CHROME_UTILITY_SAFE_BROWSING_MAC_HFS_H_
#include <hfs/hfs_format.h>
#include <stdint.h>
#include <memory>
#include <string>
#include "base/memory/raw_ptr.h"
namespace safe_browsing {
namespace dmg {
class ReadStream;
class HFSBTreeIterator;
class HFSForkReadStream;
// HFSIterator is a read-only iterator over an HFS+ file system. It provides
// access to the data fork of all files on the system, as well as the path. This
// implementation has several deliberate limitations:
// - Only HFS+ and HFSX are supported.
// - The journal file is ignored. As this is intended to be used for HFS+ in
// a DMG, replaying the journal should not typically be required.
// - The extents overflow file is not consulted. In a DMG, the file system
// should not be fragmented, and so consulting this should not typically be
// required.
// - No access is provided to resource forks.
// - Getting the ReadStream for hard linked files is not supported.
// - Files in hard linked directories are ignored.
// - No content will be returned for files that are decmpfs compressed.
// For information on the HFS format, see
// <https://developer.apple.com/legacy/library/technotes/tn/tn1150.html>.
class HFSIterator {
public:
// Constructs an iterator from a stream.
explicit HFSIterator(ReadStream* stream);
HFSIterator(const HFSIterator&) = delete;
HFSIterator& operator=(const HFSIterator&) = delete;
~HFSIterator();
// Opens the filesystem and initializes the iterator. The iterator is
// initialized to an invalid item before the first entry. Use Next() to
// advance the iterator. This method must be called before any other
// method. If this returns false, it is not legal to call any other methods.
bool Open();
// Advances the iterator to the next item. If this returns false, then it
// is not legal to call any other methods.
bool Next();
// Returns true if the current iterator item is a directory and false if it
// is a file.
bool IsDirectory();
// Returns true if the current iterator item is a symbolic link.
bool IsSymbolicLink();
// Returns true if the current iterator item is a hard link.
bool IsHardLink();
// Returns true if the current iterator item is decmpfs-compressed.
bool IsDecmpfsCompressed();
// Returns the full filesystem path of the current iterator item.
std::u16string GetPath();
// Returns a stream for the data fork of the current iterator item. This may
// only be called if IsDirectory() and IsHardLink() returns false.
std::unique_ptr<ReadStream> GetReadStream();
private:
friend class HFSForkReadStream;
// Moves the |stream_| position to a specific HFS+ |block|.
bool SeekToBlock(uint64_t block);
// Reads the catalog file to initialize the iterator.
bool ReadCatalogFile();
uint32_t block_size() const { return volume_header_.blockSize; }
ReadStream* stream() const { return stream_; }
const raw_ptr<ReadStream> stream_; // The stream backing the filesystem.
HFSPlusVolumeHeader volume_header_;
std::unique_ptr<HFSForkReadStream>
catalog_file_; // Data of the catalog file.
std::unique_ptr<HFSBTreeIterator>
catalog_; // Iterator over the catalog file.
};
} // namespace dmg
} // namespace safe_browsing
#endif // CHROME_UTILITY_SAFE_BROWSING_MAC_HFS_H_
|
