1 files changed, 66 insertions, 0 deletions
diff --git a/src/wallet/walletutil.cpp b/src/wallet/walletutil.cpp
index 34c76ec4c4..6db4c63acb 100644
--- a/src/wallet/walletutil.cpp
+++ b/src/wallet/walletutil.cpp
@@ -4,6 +4,8 @@
 
 #include <wallet/walletutil.h>
 
+#include <util/system.h>
+
 fs::path GetWalletDir()
 {
     fs::path path;
@@ -25,3 +27,67 @@ fs::path GetWalletDir()
 
     return path;
 }
+
+static bool IsBerkeleyBtree(const fs::path& path)
+{
+    // A Berkeley DB Btree file has at least 4K.
+    // This check also prevents opening lock files.
+    boost::system::error_code ec;
+    if (fs::file_size(path, ec) < 4096) return false;
+
+    fs::ifstream file(path.string(), std::ios::binary);
+    if (!file.is_open()) return false;
+
+    file.seekg(12, std::ios::beg); // Magic bytes start at offset 12
+    uint32_t data = 0;
+    file.read((char*) &data, sizeof(data)); // Read 4 bytes of file to compare against magic
+
+    // Berkeley DB Btree magic bytes, from:
+    //  https://github.com/file/file/blob/5824af38469ec1ca9ac3ffd251e7afe9dc11e227/magic/Magdir/database#L74-L75
+    //  - big endian systems - 00 05 31 62
+    //  - little endian systems - 62 31 05 00
+    return data == 0x00053162 || data == 0x62310500;
+}
+
+std::vector<fs::path> ListWalletDir()
+{
+    const fs::path wallet_dir = GetWalletDir();
+    const size_t offset = wallet_dir.string().size() + 1;
+    std::vector<fs::path> paths;
+
+    for (auto it = fs::recursive_directory_iterator(wallet_dir); it != fs::recursive_directory_iterator(); ++it) {
+        // Get wallet path relative to walletdir by removing walletdir from the wallet path.
+        // This can be replaced by boost::filesystem::lexically_relative once boost is bumped to 1.60.
+        const fs::path path = it->path().string().substr(offset);
+
+        if (it->status().type() == fs::directory_file && IsBerkeleyBtree(it->path() / "wallet.dat")) {
+            // Found a directory which contains wallet.dat btree file, add it as a wallet.
+            paths.emplace_back(path);
+        } else if (it.level() == 0 && it->symlink_status().type() == fs::regular_file && IsBerkeleyBtree(it->path())) {
+            if (it->path().filename() == "wallet.dat") {
+                // Found top-level wallet.dat btree file, add top level directory ""
+                // as a wallet.
+                paths.emplace_back();
+            } else {
+                // Found top-level btree file not called wallet.dat. Current bitcoin
+                // software will never create these files but will allow them to be
+                // opened in a shared database environment for backwards compatibility.
+                // Add it to the list of available wallets.
+                paths.emplace_back(path);
+            }
+        }
+    }
+
+    return paths;
+}
+
+WalletLocation::WalletLocation(const std::string& name)
+    : m_name(name)
+    , m_path(fs::absolute(name, GetWalletDir()))
+{
+}
+
+bool WalletLocation::Exists() const
+{
+    return fs::symlink_status(m_path).type() != fs::file_not_found;
+}