Bitcoin Core  22.99.0
P2P Digital Currency
db.cpp
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1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2020 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 
6 #include <chainparams.h>
7 #include <fs.h>
8 #include <logging.h>
9 #include <wallet/db.h>
10 
11 #include <string>
12 
13 std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
14 {
15  const size_t offset = wallet_dir.string().size() + (wallet_dir == wallet_dir.root_name() ? 0 : 1);
16  std::vector<fs::path> paths;
17  boost::system::error_code ec;
18 
19  for (auto it = fs::recursive_directory_iterator(wallet_dir, ec); it != fs::recursive_directory_iterator(); it.increment(ec)) {
20  if (ec) {
21  if (fs::is_directory(*it)) {
22  it.no_push();
23  LogPrintf("%s: %s %s -- skipping.\n", __func__, ec.message(), it->path().string());
24  } else {
25  LogPrintf("%s: %s %s\n", __func__, ec.message(), it->path().string());
26  }
27  continue;
28  }
29 
30  try {
31  // Get wallet path relative to walletdir by removing walletdir from the wallet path.
32  // This can be replaced by boost::filesystem::lexically_relative once boost is bumped to 1.60.
33  const fs::path path = it->path().string().substr(offset);
34 
35  if (it->status().type() == fs::directory_file &&
36  (IsBDBFile(BDBDataFile(it->path())) || IsSQLiteFile(SQLiteDataFile(it->path())))) {
37  // Found a directory which contains wallet.dat btree file, add it as a wallet.
38  paths.emplace_back(path);
39  } else if (it.level() == 0 && it->symlink_status().type() == fs::regular_file && IsBDBFile(it->path())) {
40  if (it->path().filename() == "wallet.dat") {
41  // Found top-level wallet.dat btree file, add top level directory ""
42  // as a wallet.
43  paths.emplace_back();
44  } else {
45  // Found top-level btree file not called wallet.dat. Current bitcoin
46  // software will never create these files but will allow them to be
47  // opened in a shared database environment for backwards compatibility.
48  // Add it to the list of available wallets.
49  paths.emplace_back(path);
50  }
51  }
52  } catch (const std::exception& e) {
53  LogPrintf("%s: Error scanning %s: %s\n", __func__, it->path().string(), e.what());
54  it.no_push();
55  }
56  }
57 
58  return paths;
59 }
60 
61 fs::path BDBDataFile(const fs::path& wallet_path)
62 {
63  if (fs::is_regular_file(wallet_path)) {
64  // Special case for backwards compatibility: if wallet path points to an
65  // existing file, treat it as the path to a BDB data file in a parent
66  // directory that also contains BDB log files.
67  return wallet_path;
68  } else {
69  // Normal case: Interpret wallet path as a directory path containing
70  // data and log files.
71  return wallet_path / "wallet.dat";
72  }
73 }
74 
75 fs::path SQLiteDataFile(const fs::path& path)
76 {
77  return path / "wallet.dat";
78 }
79 
80 bool IsBDBFile(const fs::path& path)
81 {
82  if (!fs::exists(path)) return false;
83 
84  // A Berkeley DB Btree file has at least 4K.
85  // This check also prevents opening lock files.
86  boost::system::error_code ec;
87  auto size = fs::file_size(path, ec);
88  if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), path.string());
89  if (size < 4096) return false;
90 
91  fsbridge::ifstream file(path, std::ios::binary);
92  if (!file.is_open()) return false;
93 
94  file.seekg(12, std::ios::beg); // Magic bytes start at offset 12
95  uint32_t data = 0;
96  file.read((char*) &data, sizeof(data)); // Read 4 bytes of file to compare against magic
97 
98  // Berkeley DB Btree magic bytes, from:
99  // https://github.com/file/file/blob/5824af38469ec1ca9ac3ffd251e7afe9dc11e227/magic/Magdir/database#L74-L75
100  // - big endian systems - 00 05 31 62
101  // - little endian systems - 62 31 05 00
102  return data == 0x00053162 || data == 0x62310500;
103 }
104 
105 bool IsSQLiteFile(const fs::path& path)
106 {
107  if (!fs::exists(path)) return false;
108 
109  // A SQLite Database file is at least 512 bytes.
110  boost::system::error_code ec;
111  auto size = fs::file_size(path, ec);
112  if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), path.string());
113  if (size < 512) return false;
114 
115  fsbridge::ifstream file(path, std::ios::binary);
116  if (!file.is_open()) return false;
117 
118  // Magic is at beginning and is 16 bytes long
119  char magic[16];
120  file.read(magic, 16);
121 
122  // Application id is at offset 68 and 4 bytes long
123  file.seekg(68, std::ios::beg);
124  char app_id[4];
125  file.read(app_id, 4);
126 
127  file.close();
128 
129  // Check the magic, see https://sqlite.org/fileformat2.html
130  std::string magic_str(magic, 16);
131  if (magic_str != std::string("SQLite format 3", 16)) {
132  return false;
133  }
134 
135  // Check the application id matches our network magic
136  return memcmp(Params().MessageStart(), app_id, 4) == 0;
137 }
fsbridge::ifstream
fs::ifstream ifstream
Definition: fs.h:101
fs.h
IsSQLiteFile
bool IsSQLiteFile(const fs::path &path)
Definition: db.cpp:105
chainparams.h
db.h
IsBDBFile
bool IsBDBFile(const fs::path &path)
Definition: db.cpp:80
LogPrintf
#define LogPrintf(...)
Definition: logging.h:184
BDBDataFile
fs::path BDBDataFile(const fs::path &wallet_path)
Definition: db.cpp:61
SQLiteDataFile
fs::path SQLiteDataFile(const fs::path &path)
Definition: db.cpp:75
logging.h
Params
const CChainParams & Params()
Return the currently selected parameters.
Definition: chainparams.cpp:535
ListDatabases
std::vector< fs::path > ListDatabases(const fs::path &wallet_dir)
Recursively list database paths in directory.
Definition: db.cpp:13