Merge bitcoin#12220: Error if relative -walletdir is specified

ec527c6 Don't allow relative -walletdir paths (Russell Yanofsky)

Pull request description:

  This makes it an error to explicitly specify a non-absolute -walletdir path, and also adds a debug.log warning if a relative rather than absolute -datadir path is configured.

  Specifying paths relative to the current working directory in a daemon process can be dangerous, because files can fail to be located even if the configuration doesn't change, but the daemon is started up differently.

  Specifying a relative -datadir now adds a warning to the debug log. It would not be backwards-compatible to forbid relative -datadir paths entirely, and it could also be inconvenient for command line testing.

  Specifying a relative -walletdir now results in a startup error. But since the -walletdir option is new in 0.16.0, there should be no compatibility issues. Another reason not to use working directory paths for -walletdir specifically is that the default -walletdir is a "wallets" subdirectory inside the datadir, so it could be surprising that setting -walletdir manually would choose a directory rooted in a completely different location.

Tree-SHA512: 67cbdae677f82487a9031c5ec96b0205a488ab08718a0f4f49365e025119f3d7f6cfc88ba1eba04c1ecd8b9561a5b2c42e2e1a267af7c08c76b83e5e361f5a31

src/init.cpp

@@ -1528,6 +1528,15 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
     LogPrintf("Using config file %s\n", GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME)).string());
     LogPrintf("Using at most %i automatic connections (%i file descriptors available)\n", nMaxConnections, nFD);
 
+    // Warn about relative -datadir path.
+    if (gArgs.IsArgSet("-datadir") && !fs::path(gArgs.GetArg("-datadir", "")).is_absolute()) {
+        LogPrintf("Warning: relative datadir option '%s' specified, which will be interpreted relative to the "
+                  "current working directory '%s'. This is fragile, because if bitcoin is started in the future "
+                  "from a different location, it will be unable to locate the current data files. There could "
+                  "also be data loss if bitcoin is started while in a temporary directory.\n",
+            gArgs.GetArg("-datadir", ""), fs::current_path().string());
+    }
+
     InitSignatureCache();
     InitScriptExecutionCache();
 

src/wallet/init.cpp

@@ -212,8 +212,15 @@ bool VerifyWallets()
         return true;
     }
 
-    if (gArgs.IsArgSet("-walletdir") && !fs::is_directory(GetWalletDir())) {
-        return InitError(strprintf(_("Error: Specified wallet directory \"%s\" does not exist."), gArgs.GetArg("-walletdir", "").c_str()));
+    if (gArgs.IsArgSet("-walletdir")) {
+        fs::path wallet_dir = gArgs.GetArg("-walletdir", "");
+        if (!fs::exists(wallet_dir)) {
+            return InitError(strprintf(_("Specified -walletdir \"%s\" does not exist"), wallet_dir.string()));
+        } else if (!fs::is_directory(wallet_dir)) {
+            return InitError(strprintf(_("Specified -walletdir \"%s\" is not a directory"), wallet_dir.string()));
+        } else if (!wallet_dir.is_absolute()) {
+            return InitError(strprintf(_("Specified -walletdir \"%s\" is a relative path"), wallet_dir.string()));
+        }
     }
 
     LogPrintf("Using wallet directory %s\n", GetWalletDir().string());

src/wallet/walletutil.cpp

@@ -9,7 +9,7 @@ fs::path GetWalletDir()
     fs::path path;
 
     if (gArgs.IsArgSet("-walletdir")) {
-        path = fs::system_complete(gArgs.GetArg("-walletdir", ""));
+        path = gArgs.GetArg("-walletdir", "");
         if (!fs::is_directory(path)) {
             // If the path specified doesn't exist, we return the deliberately
             // invalid empty string.

test/functional/multiwallet.py

@@ -23,6 +23,10 @@ def run_test(self):
 
         self.stop_node(0)
 
+        self.assert_start_raises_init_error(0, ['-walletdir=wallets'], 'Error: Specified -walletdir "wallets" does not exist')
+        self.assert_start_raises_init_error(0, ['-walletdir=wallets'], 'Error: Specified -walletdir "wallets" is a relative path', cwd=data_dir())
+        self.assert_start_raises_init_error(0, ['-walletdir=debug.log'], 'Error: Specified -walletdir "debug.log" is not a directory', cwd=data_dir())
+
         # should not initialize if there are duplicate wallets
         self.assert_start_raises_init_error(0, ['-wallet=w1', '-wallet=w1'], 'Error loading wallet w1. Duplicate -wallet filename specified.')
 

test/functional/test_framework/test_framework.py

@@ -249,26 +249,26 @@ def add_nodes(self, num_nodes, extra_args=None, rpchost=None, timewait=None, bin
         for i in range(num_nodes):
             self.nodes.append(TestNode(old_num_nodes + i, self.options.tmpdir, extra_args[i], rpchost, timewait=timewait, binary=binary[i], stderr=stderr, mocktime=self.mocktime, coverage_dir=self.options.coveragedir))
 
-    def start_node(self, i, extra_args=None, stderr=None):
+    def start_node(self, i, *args, **kwargs):
         """Start a dashd"""
 
         node = self.nodes[i]
 
-        node.start(extra_args, stderr)
+        node.start(*args, **kwargs)
         node.wait_for_rpc_connection()
 
         if self.options.coveragedir is not None:
             coverage.write_all_rpc_commands(self.options.coveragedir, node.rpc)
 
-    def start_nodes(self, extra_args=None, stderr=None):
+    def start_nodes(self, extra_args=None, stderr=None, *args, **kwargs):
         """Start multiple dashds"""
 
         if extra_args is None:
             extra_args = [None] * self.num_nodes
         assert_equal(len(extra_args), self.num_nodes)
         try:
             for i, node in enumerate(self.nodes):
-                node.start(extra_args[i], stderr)
+                node.start(extra_args[i], *args, **kwargs)
             for node in self.nodes:
                 node.wait_for_rpc_connection()
         except:
@@ -300,10 +300,10 @@ def restart_node(self, i, extra_args=None):
         self.stop_node(i)
         self.start_node(i, extra_args)
 
-    def assert_start_raises_init_error(self, i, extra_args=None, expected_msg=None):
+    def assert_start_raises_init_error(self, i, extra_args=None, expected_msg=None, *args, **kwargs):
         with tempfile.SpooledTemporaryFile(max_size=2**16) as log_stderr:
             try:
-                self.start_node(i, extra_args, stderr=log_stderr)
+                self.start_node(i, extra_args, stderr=log_stderr, *args, **kwargs)
                 self.stop_node(i)
             except Exception as e:
                 assert 'dashd exited' in str(e)  # node must have shutdown

test/functional/test_framework/test_node.py

@@ -77,13 +77,13 @@ def __getattr__(self, name):
         assert self.rpc_connected and self.rpc is not None, "Error: no RPC connection"
         return getattr(self.rpc, name)
 
-    def start(self, extra_args=None, stderr=None):
+    def start(self, extra_args=None, stderr=None, *args, **kwargs):
         """Start the node."""
         if extra_args is None:
             extra_args = self.extra_args
         if stderr is None:
             stderr = self.stderr
-        self.process = subprocess.Popen(self.args + extra_args, stderr=stderr)
+        self.process = subprocess.Popen(self.args + extra_args, stderr=stderr, *args, **kwargs)
         self.running = True
         self.log.debug("dashd started, waiting for RPC to come up")