db.cpp raw
1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-present 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 <common/args.h>
8 #include <util/fs.h>
9 #include <util/log.h>
10 #include <wallet/db.h>
11
12 #include <algorithm>
13 #include <exception>
14 #include <fstream>
15 #include <string>
16 #include <system_error>
17 #include <vector>
18
19 namespace wallet {
20 bool operator<(BytePrefix a, std::span<const std::byte> b) { return std::ranges::lexicographical_compare(a.prefix, b.subspan(0, std::min(a.prefix.size(), b.size()))); }
21 bool operator<(std::span<const std::byte> a, BytePrefix b) { return std::ranges::lexicographical_compare(a.subspan(0, std::min(a.size(), b.prefix.size())), b.prefix); }
22
23 std::vector<std::pair<fs::path, std::string>> ListDatabases(const fs::path& wallet_dir)
24 {
25 std::vector<std::pair<fs::path, std::string>> paths;
26 std::error_code ec;
27
28 for (auto it = fs::recursive_directory_iterator(wallet_dir, ec); it != fs::recursive_directory_iterator(); it.increment(ec)) {
29 assert(!ec); // Loop should exit on error.
30 try {
31 const fs::path path{it->path().lexically_relative(wallet_dir)};
32
33 if (it->status().type() == fs::file_type::directory) {
34 if (IsBDBFile(BDBDataFile(it->path()))) {
35 // Found a directory which contains wallet.dat btree file, add it as a wallet with BERKELEY format.
36 paths.emplace_back(path, "bdb");
37 } else if (IsSQLiteFile(SQLiteDataFile(it->path()))) {
38 // Found a directory which contains wallet.dat sqlite file, add it as a wallet with SQLITE format.
39 paths.emplace_back(path, "sqlite");
40 }
41 } else if (it.depth() == 0 && it->symlink_status().type() == fs::file_type::regular && it->path().extension() != ".bak") {
42 if (it->path().filename() == "wallet.dat") {
43 // Found top-level wallet.dat file, add top level directory ""
44 // as a wallet.
45 if (IsBDBFile(it->path())) {
46 paths.emplace_back(fs::path(), "bdb");
47 } else if (IsSQLiteFile(it->path())) {
48 paths.emplace_back(fs::path(), "sqlite");
49 }
50 } else if (IsBDBFile(it->path())) {
51 // Found top-level btree file not called wallet.dat. Current bitcoin
52 // software will never create these files but will allow them to be
53 // opened in a shared database environment for backwards compatibility.
54 // Add it to the list of available wallets.
55 paths.emplace_back(path, "bdb");
56 }
57 }
58 } catch (const std::exception& e) {
59 LogWarning("Error while scanning wallet dir item: %s [%s].", e.what(), fs::PathToString(it->path()));
60 it.disable_recursion_pending();
61 }
62 }
63 if (ec) {
64 // Loop could have exited with an error due to one of:
65 // * wallet_dir itself not being scannable.
66 // * increment() failure. (Observed on Windows native builds when
67 // removing the ACL read permissions of a wallet directory after the
68 // process started).
69 LogWarning("Error scanning directory entries under %s: %s", fs::PathToString(wallet_dir), ec.message());
70 }
71
72 return paths;
73 }
74
75 fs::path BDBDataFile(const fs::path& wallet_path)
76 {
77 if (fs::is_regular_file(wallet_path)) {
78 // Special case for backwards compatibility: if wallet path points to an
79 // existing file, treat it as the path to a BDB data file in a parent
80 // directory that also contains BDB log files.
81 return wallet_path;
82 } else {
83 // Normal case: Interpret wallet path as a directory path containing
84 // data and log files.
85 return wallet_path / "wallet.dat";
86 }
87 }
88
89 fs::path SQLiteDataFile(const fs::path& path)
90 {
91 return path / "wallet.dat";
92 }
93
94 bool IsBDBFile(const fs::path& path)
95 {
96 if (!fs::exists(path)) return false;
97
98 // A Berkeley DB Btree file has at least 4K.
99 // This check also prevents opening lock files.
100 std::error_code ec;
101 auto size = fs::file_size(path, ec);
102 if (ec) LogWarning("Error reading file_size: %s [%s]", ec.message(), fs::PathToString(path));
103 if (size < 4096) return false;
104
105 std::ifstream file{path.std_path(), std::ios::binary};
106 if (!file.is_open()) return false;
107
108 file.seekg(12, std::ios::beg); // Magic bytes start at offset 12
109 uint32_t data = 0;
110 file.read((char*) &data, sizeof(data)); // Read 4 bytes of file to compare against magic
111
112 // Berkeley DB Btree magic bytes, from:
113 // https://github.com/file/file/blob/5824af38469ec1ca9ac3ffd251e7afe9dc11e227/magic/Magdir/database#L74-L75
114 // - big endian systems - 00 05 31 62
115 // - little endian systems - 62 31 05 00
116 return data == 0x00053162 || data == 0x62310500;
117 }
118
119 bool IsSQLiteFile(const fs::path& path)
120 {
121 if (!fs::exists(path)) return false;
122
123 // A SQLite Database file is at least 512 bytes.
124 std::error_code ec;
125 auto size = fs::file_size(path, ec);
126 if (ec) LogWarning("Error reading file_size: %s [%s]", ec.message(), fs::PathToString(path));
127 if (size < 512) return false;
128
129 std::ifstream file{path.std_path(), std::ios::binary};
130 if (!file.is_open()) return false;
131
132 // Magic is at beginning and is 16 bytes long
133 char magic[16];
134 file.read(magic, 16);
135
136 // Application id is at offset 68 and 4 bytes long
137 file.seekg(68, std::ios::beg);
138 char app_id[4];
139 file.read(app_id, 4);
140
141 file.close();
142
143 // Check the magic, see https://sqlite.org/fileformat.html
144 std::string magic_str(magic, 16);
145 if (magic_str != std::string{"SQLite format 3\000", 16}) {
146 return false;
147 }
148
149 // Check the application id matches our network magic
150 return memcmp(Params().MessageStart().data(), app_id, 4) == 0;
151 }
152
153 void ReadDatabaseArgs(const ArgsManager& args, DatabaseOptions& options)
154 {
155 // Override current options with args values, if any were specified
156 options.use_unsafe_sync = args.GetBoolArg("-unsafesqlitesync", options.use_unsafe_sync);
157 }
158
159 } // namespace wallet
160