Merge pull request #1758 from laanwj/2012_08_uiconsole_parsing

Fix RPC console parser to handle escaped arguments more like bash

src/qt/rpcconsole.cpp

@@ -13,7 +13,6 @@
 #include <QUrl>
 #include <QScrollBar>
 
-#include <boost/tokenizer.hpp>
 #include <openssl/crypto.h>
 
 // TODO: make it possible to filter out categories (esp debug messages when implemented)
@@ -54,34 +53,114 @@ void RPCExecutor::start()
    // Nothing to do
 }
 
-void RPCExecutor::request(const QString &command)
+/**
+ * Split shell command line into a list of arguments. Aims to emulate \c bash and friends.
+ * 
+ * - Arguments are delimited with whitespace
+ * - Extra whitespace at the beginning and end and between arguments will be ignored
+ * - Arguments can be "double" or 'single' quoted. Those are treated the same.
+ * - The backslash '\' is used as escape character
+ *   - Outside quotes, any character can be escaped
+ *   - Within double quotes, only escape double quotes with \" and backslashes with \\
+ *   - Within single quotes, only escape single quotes with \' and backslashes with \\
+ *
+ * @param[out]   args        Parsed arguments will be appended to this list
+ * @param[in]    strCommand  Command line to split
+ */
+bool parseCommandLine(std::vector<std::string> &args, const std::string &strCommand)
 {
-    // Parse shell-like command line into separate arguments
+    enum CmdParseState
-    std::string strMethod;
+    {
-    std::vector<std::string> strParams;
+        STATE_EATING_SPACES,
-    try {
+        STATE_ARGUMENT,
-        boost::escaped_list_separator<char> els('\\',' ','\"');
+        STATE_SINGLEQUOTED,
-        std::string strCommand = command.toStdString();
+        STATE_DOUBLEQUOTED,
-        boost::tokenizer<boost::escaped_list_separator<char> > tok(strCommand, els);
+        STATE_ESCAPE_OUTER,
-
+        STATE_ESCAPE_SINGLEQUOTED,
-        int n = 0;
+        STATE_ESCAPE_DOUBLEQUOTED
-        for(boost::tokenizer<boost::escaped_list_separator<char> >::iterator beg=tok.begin(); beg!=tok.end();++beg,++n)
+    } state = STATE_EATING_SPACES;
+    std::string curarg;
+    foreach(char ch, strCommand)
+    {
+        switch(state)
         {
-            if(n == 0) // First parameter is the command
+        case STATE_ARGUMENT: // After argument
-                strMethod = *beg;
+        case STATE_EATING_SPACES: // Handle runs of spaces
-            else
+            switch(ch)
-                strParams.push_back(*beg);
+            {
+            case '"': state = STATE_DOUBLEQUOTED; break;
+            case '\'': state = STATE_SINGLEQUOTED; break;
+            case '\\': state = STATE_ESCAPE_OUTER; break;
+            case ' ': case '\n': case '\t':
+                if(state == STATE_ARGUMENT) // Space ends argument
+                {
+                    args.push_back(curarg);
+                    curarg.clear();
+                }
+                state = STATE_EATING_SPACES;
+                break;
+            default: curarg += ch; state = STATE_ARGUMENT;
+            }
+            break;
+        case STATE_SINGLEQUOTED: // Single-quoted string
+            switch(ch)
+            {
+            case '\'': state = STATE_ARGUMENT; break;
+            case '\\': state = STATE_ESCAPE_SINGLEQUOTED; break;
+            default: curarg += ch;
+            }
+            break;
+        case STATE_DOUBLEQUOTED: // Double-quoted string
+            switch(ch)
+            {
+            case '"': state = STATE_ARGUMENT; break;
+            case '\\': state = STATE_ESCAPE_DOUBLEQUOTED; break;
+            default: curarg += ch;
+            }
+            break;
+        case STATE_ESCAPE_OUTER: // '\' outside quotes
+            curarg += ch; state = STATE_ARGUMENT;
+            break;
+        case STATE_ESCAPE_SINGLEQUOTED: // '\' in single-quoted text
+            if(ch != '\'') curarg += '\\'; // keep '\' for everything but the quote
+            curarg += ch; state = STATE_SINGLEQUOTED;
+            break;
+        case STATE_ESCAPE_DOUBLEQUOTED: // '\' in double-quoted text
+            if(ch != '"') curarg += '\\'; // keep '\' for everything but the quote
+            curarg += ch; state = STATE_DOUBLEQUOTED;
+            break;
         }
     }
-    catch(boost::escaped_list_error &e)
+    switch(state) // final state
     {
-        emit reply(RPCConsole::CMD_ERROR, QString("Parse error"));
+    case STATE_EATING_SPACES:
-        return;
+        return true;
+    case STATE_ARGUMENT:
+        args.push_back(curarg);
+        return true;
+    default: // ERROR to end in one of the other states
+        return false;
     }
+}
 
-    try {
+void RPCExecutor::request(const QString &command)
+{
+    std::vector<std::string> args;
+    if(!parseCommandLine(args, command.toStdString()))
+    {
+        emit reply(RPCConsole::CMD_ERROR, QString("Parse error: unbalanced ' or \""));
+        return;
+    }
+    if(args.empty())
+        return; // Nothing to do
+    try
+    {
         std::string strPrint;
-        json_spirit::Value result = tableRPC.execute(strMethod, RPCConvertValues(strMethod, strParams));
+        // Convert argument list to JSON objects in method-dependent way,
+        // and pass it along with the method name to the dispatcher.
+        json_spirit::Value result = tableRPC.execute(
+            args[0],
+            RPCConvertValues(args[0], std::vector<std::string>(args.begin() + 1, args.end())));
 
         // Format result reply
         if (result.type() == json_spirit::null_type)
@@ -95,7 +174,17 @@ void RPCExecutor::request(const QString &command)
     }
     catch (json_spirit::Object& objError)
     {
-        emit reply(RPCConsole::CMD_ERROR, QString::fromStdString(write_string(json_spirit::Value(objError), false)));
+        try // Nice formatting for standard-format error
+        {
+            int code = find_value(objError, "code").get_int();
+            std::string message = find_value(objError, "message").get_str();
+            emit reply(RPCConsole::CMD_ERROR, QString::fromStdString(message) + " (code " + QString::number(code) + ")");
+        }
+        catch(std::runtime_error &) // raised when converting to invalid type, i.e. missing code or message
+        {
+            // Show raw JSON object
+            emit reply(RPCConsole::CMD_ERROR, QString::fromStdString(write_string(json_spirit::Value(objError), false)));
+        }
     }
     catch (std::exception& e)
     {