Telent protocol Nasal command

src/Main/main.cxx

@@ -386,6 +386,26 @@ void fgResetIdleState()
     fgRegisterIdleHandler( &fgIdleFunction );
 }
 
+void fgInitSecureMode()
+{
+    bool secureMode = true;
+    if (Options::sharedInstance()->isOptionSet("allow-nasal-from-sockets")) {
+        SG_LOG(SG_GENERAL, SG_ALERT, "\n!! Network connections allowed to use Nasal !!\n"
+       "Network connections will be allowed full access to the simulator \n"
+       "including running arbitrary scripts. Ensure you have adequate security\n"
+        "(such as a firewall which blocks external connections).\n");
+        secureMode = false;
+    }
+    
+    // it's by design that we overwrite any existing property tree value
+    // here - this prevents an aircraft or add-on setting the property
+    // value underneath us, eg in their -set.xml
+    SGPropertyNode_ptr secureFlag = fgGetNode("/sim/secure-flag", true);
+    secureFlag->setBoolValue(secureMode);
+    secureFlag->setAttributes(SGPropertyNode::READ |
+                              SGPropertyNode::PRESERVE |
+                              SGPropertyNode::PROTECTED);
+}
 
 static void upper_case_property(const char *name)
 {
@@ -470,8 +490,7 @@ int fgMainInit( int argc, char **argv )
     }
 
     std::string version(FLIGHTGEAR_VERSION);
-    SG_LOG( SG_GENERAL, SG_INFO, "FlightGear:  Version "
+    SG_LOG( SG_GENERAL, SG_INFO, "FlightGear:  Version " << version );
-            << version );
     SG_LOG( SG_GENERAL, SG_INFO, "FlightGear:  Build Type " << FG_BUILD_TYPE );
     SG_LOG( SG_GENERAL, SG_INFO, "Built with " << SG_COMPILER_STR);
 	SG_LOG( SG_GENERAL, SG_INFO, "Jenkins number/ID " << HUDSON_BUILD_NUMBER << ":"
@@ -529,9 +548,11 @@ int fgMainInit( int argc, char **argv )
     }
 #else
     if (showLauncher) {
-        SG_LOG(SG_GENERAL, SG_ALERT, "\n!Launcher requested, but FlightGear was compiled without Qt support!");
+        SG_LOG(SG_GENERAL, SG_ALERT, "\n!Launcher requested, but FlightGear was compiled without Qt support!\n");
     }
 #endif
+    
+    fgInitSecureMode();
     fgInitAircraftPaths(false);
 
     configResult = fgInitAircraft(false);

src/Main/options.cxx

@@ -1621,6 +1621,7 @@ struct OptionDesc {
     {"language",                     true,  OPTION_IGNORE, "", false, "", 0 },
 	{"console",                      false, OPTION_FUNC,   "", false, "", fgOptConsole },
     {"launcher",                     false, OPTION_IGNORE,   "", false, "", 0 },
+    {"allow-nasal-from-sockets",     false, OPTION_IGNORE,   "", false, "", 0 },
     {"disable-rembrandt",            false, OPTION_BOOL,   "/sim/rendering/rembrandt/enabled", false, "", 0 },
     {"enable-rembrandt",             false, OPTION_BOOL,   "/sim/rendering/rembrandt/enabled", true, "", 0 },
     {"renderer",                     true,  OPTION_STRING, "/sim/rendering/rembrandt/renderer", false, "", 0 },

src/Network/props.cxx

@@ -40,9 +40,11 @@
 #include <iostream>
 #include <errno.h>
 #include <algorithm>
+#include <functional>
 
 #include <Main/globals.hxx>
 #include <Viewer/viewmgr.hxx>
+#include <Scripting/NasalSys.hxx>
 
 #include <simgear/io/sg_netChat.hxx>
 
@@ -73,13 +75,13 @@ class FGProps::PropsChannel : public simgear::NetChat, public SGPropertyChangeLi
     /**
      * Current property node name.
      */
-    string path;
+    string path= "/";
 
     enum Mode {
         PROMPT,
         DATA
     };
-    Mode mode;
+    Mode mode = PROMPT;
 
 public:
     /**
@@ -136,22 +138,23 @@ private:
     // callback implementations:
     void subscribe(const ParameterList &p);
     void unsubscribe(const ParameterList &p);
+    void beginNasal(const ParameterList &p);
 
     FGProps* _owner = nullptr;
+    bool _colletingNasal = false;
 };
 
 /**
  *
  */
 FGProps::PropsChannel::PropsChannel(FGProps* owner)
-    : buffer(8192),
+    : buffer(8192)
-      path("/"),
+    , _owner(owner)
-      mode(PROMPT),
-      _owner(owner)
 {
     setTerminator( "\r\n" );
     callback_map["subscribe"] 	= 	&PropsChannel::subscribe;
     callback_map["unsubscribe"]	=	&PropsChannel::unsubscribe;
+    callback_map["nasal"] =         &PropsChannel::beginNasal;
 }
 
 FGProps::PropsChannel::~PropsChannel()
@@ -204,6 +207,18 @@ void FGProps::PropsChannel::unsubscribe(const ParameterList &param) {
   }
 }
 
+void FGProps::PropsChannel::beginNasal(const ParameterList &param)
+{
+    std::string eofMarker = "##EOF##";
+    if (param.size() > 1) {
+        if ((param.at(1) == "eof") && (param.size() >= 3)) {
+            eofMarker = param.at(2);
+        }
+    } // of optional argument parsing
+    
+    _colletingNasal = true;
+    setTerminator(eofMarker);
+}
 
 //TODO: provide support for different types of subscriptions MODES ? (child added/removed, thesholds, min/max)
   void FGProps::PropsChannel::valueChanged(SGPropertyNode* ptr)
@@ -276,8 +291,35 @@ getValueTypeString( const SGPropertyNode *node )
 void
 FGProps::PropsChannel::foundTerminator()
 {
+    if (_colletingNasal) {
+        std::string nasalSource = buffer.getData(); // make a copy
+        _colletingNasal = false;
+        setTerminator("\r\n");
+        buffer.remove(); // safe since we copied the source above
+
+        if (globals->get_props()->getBoolValue("sim/secure-flag", true) == true) {
+            SG_LOG(SG_IO, SG_ALERT, "Telnet connection trying to run Nasal, blocked it.\n"
+                   "Run the simulator with --allow-nasal-from-sockets to allow this.");
+            error("Simulator running in secure mode, Nasal execution blocked.");
+        } else {
+            auto nasal = globals->get_subsystem<FGNasalSys>();
+            if (nasal) {
+                std::string errors, output;
+                bool ok = nasal->parseAndRunWithOutput(nasalSource, output, errors);
+                if (!ok) {
+                    error("Nasal error" + errors);
+                } else if (!output.empty()) {
+                    // success and we have output: push it
+                    push(output.c_str());
+                }
+            }
+        }
+        
+        return;
+    }
+    
     const char* cmd = buffer.getData();
-    SG_LOG( SG_IO, SG_INFO, "processing command = \"" << cmd << "\"" );
+    SG_LOG( SG_IO, SG_DEBUG, "processing command = \"" << cmd << "\"" );
 
     ParameterList tokens = simgear::strutils::split( cmd );
 
@@ -506,12 +548,12 @@ FGProps::PropsChannel::foundTerminator()
             } else if ( command == "prompt" ) {
                 mode = PROMPT;
             } else if (callback_map.find(command) != callback_map.end() ) {
-		   TelnetCallback t = callback_map[ command ];
+                TelnetCallback t = callback_map[ command ];
-		   if (t)
+                if (t)
-		     	   (this->*t) (tokens);
+                    (this->*t) (tokens);
-		   else
+                else
-			   error("No matching callback found for command:"+command);
+                    error("No matching callback found for command:"+command);
-	    }
+            }
       else if ( command == "seti" ) {
         string value, tmp;
         if (tokens.size() == 3) {
@@ -604,7 +646,9 @@ setf <var> <val>   alias for setd\r\n\
 seti <var> <val>   set Int <var> to a new <val>\r\n\
 del <var> <nod>    delete <nod> in <var>\r\n\
 subscribe <var>	   subscribe to property changes \r\n\
-unscubscribe <var>  unscubscribe from property changes (var must be the property name/path used by subscribe)\r\n";
+unsubscribe <var>  unscubscribe from property changes (var must be the property name/path used by subscribe)\r\n\
+nasal [EOF <marker>]  execute arbitrary Nasal code (simulator must be running with Nasal allowed from sockets)\r\n\
+";
                 push( msg );
             }
         }
@@ -615,7 +659,7 @@ unscubscribe <var>  unscubscribe from property changes (var must be the property
         push( getTerminator() );
     }
 
-    if ( mode == PROMPT ) {
+    if ( (mode == PROMPT) && !_colletingNasal) {
         string prompt = node->getPath();
         if (prompt.empty()) {
             prompt = "/";

src/Network/props.hxx

@@ -49,7 +49,7 @@ private:
     /**
      * Server port to listen on.
      */
-    int port;
+    int port = 5501;
     simgear::NetChannelPoller poller;
 
     std::vector<PropsChannel*> _activeChannels;
@@ -69,22 +69,22 @@ public:
     /**
      * Start the telnet server.
      */
-    bool open();
+    bool open() override;
 
     /**
      * Process network activity.
      */
-    bool process();
+    bool process() override;
 
     /**
      * 
      */
-    bool close();
+    bool close() override;
 
     /**
      * Accept a new client connection.
      */
-    void handleAccept();
+    void handleAccept() override;
 
     void removeChannel(PropsChannel* channel);
 };

src/Scripting/NasalSys.cxx

@@ -298,20 +298,37 @@ FGNasalSys::~FGNasalSys()
     nasalSys = 0;
 }
 
-bool FGNasalSys::parseAndRun(const char* sourceCode)
+bool FGNasalSys::parseAndRunWithOutput(const std::string& source, std::string& output, std::string& errors)
 {
     naContext ctx = naNewContext();
-    naRef code = parse(ctx, "FGNasalSys::parseAndRun()", sourceCode,
+    naRef code = parse(ctx, "FGNasalSys::parseAndRun()", source.c_str(),
-                       strlen(sourceCode));
+                       source.size(), errors);
     if(naIsNil(code)) {
         naFreeContext(ctx);
         return false;
     }
-    callWithContext(ctx, code, 0, 0, naNil());
+    naRef result = callWithContext(ctx, code, 0, 0, naNil());
+    
+    // if there was a result value, try to convert it to a string
+    // value.
+    if (!naIsNil(result)) {
+        naRef s = naStringValue(ctx, result);
+        if (!naIsNil(s)) {
+            output = naStr_data(s);
+        }
+    }
+    
     naFreeContext(ctx);
     return true;
 }
 
+bool FGNasalSys::parseAndRun(const std::string& source)
+{
+    std::string errors;
+    std::string output;
+    return parseAndRunWithOutput(source, output, errors);
+}
+
 #if 0
 FGNasalScript* FGNasalSys::parseScript(const char* src, const char* name)
 {
@@ -1208,7 +1225,8 @@ bool FGNasalSys::createModule(const char* moduleName, const char* fileName,
                               int argc, naRef* args)
 {
     naContext ctx = naNewContext();
-    naRef code = parse(ctx, fileName, src, len);
+    std::string errors;
+    naRef code = parse(ctx, fileName, src, len, errors);
     if(naIsNil(code)) {
         naFreeContext(ctx);
         return false;
@@ -1257,16 +1275,21 @@ naRef FGNasalSys::getModule(const char* moduleName)
     return mod;
 }
 
-naRef FGNasalSys::parse(naContext ctx, const char* filename, const char* buf, int len)
+naRef FGNasalSys::parse(naContext ctx, const char* filename,
+                        const char* buf, int len,
+                        std::string& errors)
 {
     int errLine = -1;
     naRef srcfile = naNewString(ctx);
     naStr_fromdata(srcfile, (char*)filename, strlen(filename));
     naRef code = naParseCode(ctx, srcfile, 1, (char*)buf, len, &errLine);
     if(naIsNil(code)) {
-        SG_LOG(SG_NASAL, SG_ALERT,
+        std::ostringstream errorMessageStream;
-               "Nasal parse error: " << naGetError(ctx) <<
+        errorMessageStream << "Nasal parse error: " << naGetError(ctx) <<
-               " in "<< filename <<", line " << errLine);
+            " in "<< filename <<", line " << errLine;
+        errors = errorMessageStream.str();
+        SG_LOG(SG_NASAL, SG_ALERT, errors);
+               
         return naNil();
     }
 
@@ -1281,7 +1304,8 @@ bool FGNasalSys::handleCommand( const char* moduleName,
                                 SGPropertyNode* root)
 {
     naContext ctx = naNewContext();
-    naRef code = parse(ctx, fileName, src, strlen(src));
+    std::string errorMessage;
+    naRef code = parse(ctx, fileName, src, strlen(src), errorMessage);
     if(naIsNil(code)) {
         naFreeContext(ctx);
         return false;

src/Scripting/NasalSys.hxx

@@ -48,8 +48,12 @@ public:
     // indicate successful execution.  Does *not* return any Nasal
     // values, because handling garbage-collected objects from C space
     // is deep voodoo and violates the "simple hook" idea.
-    bool parseAndRun(const char* sourceCode);
+    bool parseAndRun(const std::string& source);
 
+    bool parseAndRunWithOutput(const std::string& source,
+                     std::string& output,
+                     std::string& errors);
+    
     // Slightly more complicated hook to get a handle to a precompiled
     // Nasal script that can be invoked via a call() method.  The
     // caller is expected to delete the FGNasalScript returned from
@@ -191,7 +195,8 @@ private:
     void loadScriptDirectory(simgear::Dir nasalDir);
     void addModule(std::string moduleName, simgear::PathList scripts);
     static void logError(naContext);
-    naRef parse(naContext ctx, const char* filename, const char* buf, int len);
+    naRef parse(naContext ctx, const char* filename, const char* buf, int len,
+                std::string& errors);
     naRef genPropsModule();
 
     bool _inited;