Callout from @BeipDev on an incorrect reading of the CHARSET RFC. Adj…

…usted Unit Test and Code.
HarryCordewener · Jan 2, 2024 · 12da8b5 · 12da8b5
1 parent 5bbecc6
commit 12da8b5
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Showing 3 changed files with 74 additions and 13 deletions.
diff --git a/TelnetNegotiationCore/Interpretors/TelnetCharsetInterpretor.cs b/TelnetNegotiationCore/Interpretors/TelnetCharsetInterpretor.cs
@@ -238,20 +238,12 @@ private async Task CompleteAcceptedCharsetAsync(StateMachine<State, Trigger>.Tra
 		{
 			try
 			{
-				CurrentEncoding = Encoding.GetEncoding(ascii.GetString(_acceptedCharsetByteState, 1, _acceptedCharsetByteIndex - 1).Trim());
+				CurrentEncoding = Encoding.GetEncoding(ascii.GetString(_acceptedCharsetByteState, 0, _acceptedCharsetByteIndex).Trim());
 			}
-			catch (Exception ex1)
+			catch (Exception ex)
 			{
-				_Logger.Warning(ex1, "Potentially expected error during Accepting Charset Negotiation. Seperator not passed back. Trying without seperator.");
-				try
-				{
-					CurrentEncoding = Encoding.GetEncoding(ascii.GetString(_acceptedCharsetByteState, 0, _acceptedCharsetByteIndex).Trim());
-				}
-				catch (Exception ex2)
-				{
-					_Logger.Warning(ex2, "Unexpected error during Accepting Charset Negotiation. Could not find charset: {charset}", ascii.GetString(_acceptedCharsetByteState, 0, _acceptedCharsetByteIndex));
-					await CallbackNegotiation(new byte[] { (byte)Trigger.IAC, (byte)Trigger.SB, (byte)Trigger.CHARSET, (byte)Trigger.REJECTED, (byte)Trigger.IAC, (byte)Trigger.SE });
-				}
+				_Logger.Error(ex, "Unexpected error during Accepting Charset Negotiation. Could not find charset: {charset}", ascii.GetString(_acceptedCharsetByteState, 0, _acceptedCharsetByteIndex));
+				await CallbackNegotiation(new byte[] { (byte)Trigger.IAC, (byte)Trigger.SB, (byte)Trigger.CHARSET, (byte)Trigger.REJECTED, (byte)Trigger.IAC, (byte)Trigger.SE });
 			}
 			_Logger.Information("Connection: Accepted Charset Negotiation for: {charset}", CurrentEncoding.WebName);
 			charsetoffered = false;

diff --git a/TelnetNegotiationCore/Interpretors/TelnetMSSPInterpretor.cs b/TelnetNegotiationCore/Interpretors/TelnetMSSPInterpretor.cs
@@ -14,6 +14,9 @@ public partial class TelnetInterpretor
 	{
 		private MSSPConfig _msspConfig;
 
+		private List<byte> _currentVariable;
+		private List<byte> _currentValue;
+
 		/// <summary>
 		/// Mud Server Status Protocol will provide information to the requestee about the server's contents.
 		/// </summary>
@@ -55,12 +58,72 @@ private StateMachine<State, Trigger> SetupMSSPNegotiation(StateMachine<State, Tr
 					.SubstateOf(State.Accepting)
 					.OnEntry(() => _Logger.Debug("Connection: {connectionStatus}", "Server won't do MSSP - do nothing"));
 
-				/// TODO: Accept MSSP and interpret it into a structure.
+				tsm.Configure(State.SubNegotiation)
+					.Permit(Trigger.MSSP, State.AlmostNegotiatingMSSP)
+					.OnEntry(() => {
+						_currentValue = new List<byte>();
+						_currentVariable = new List<byte>();
+					});
+
+				tsm.Configure(State.AlmostNegotiatingMSSP)
+					.Permit(Trigger.MSSP_VAR, State.EvaluatingMSSPVar);
+
+				tsm.Configure(State.EvaluatingMSSPVar)
+					.Permit(Trigger.MSSP_VAL, State.EvaluatingMSSPVal)
+					.Permit(Trigger.IAC, State.EscapingMSSPVar);
+
+				tsm.Configure(State.EscapingMSSPVar)
+					.Permit(Trigger.IAC, State.EvaluatingMSSPVar);
+
+				tsm.Configure(State.EvaluatingMSSPVal)
+					.Permit(Trigger.MSSP_VAR, State.EvaluatingMSSPVar)
+					.Permit(Trigger.IAC, State.EscapingMSSPVal);
+
+				tsm.Configure(State.EscapingMSSPVal)
+					.Permit(Trigger.IAC, State.EvaluatingMSSPVal)
+					.Permit(Trigger.SE, State.CompletingMSSP);
+
+				tsm.Configure(State.CompletingMSSP)
+					.SubstateOf(State.Accepting)
+					.OnEntryAsync(ReadMSSPValues);
+
+				TriggerHelper.ForAllTriggers(t => tsm.Configure(State.EvaluatingMSSPVal).OnEntryFrom(ParametarizedTrigger(t), CaptureValue));
+				TriggerHelper.ForAllTriggers(t => tsm.Configure(State.EvaluatingMSSPVar).OnEntryFrom(ParametarizedTrigger(t), CaptureVariable));
 			}
 
 			return tsm;
 		}
 
+		private async Task ReadMSSPValues()
+		{
+			var variableList = _currentVariable.Split((byte)Trigger.MSSP_VAR);
+			var valueList = _currentVariable.Split((byte)Trigger.MSSP_VAL);
+
+			var vv = variableList.Zip(valueList);
+
+			await Task.CompletedTask;
+		}
+
+		/*
+		 * For ease of parsing, variables and values cannot contain the MSSP_VAL, MSSP_VAR, IAC, or NUL byte. 
+		 * The value can be an empty string unless a numeric value is expected in which case the default value should be 0. 
+		 * If your Mud can't calculate one of the numeric values for the World variables you can use "-1" to indicate that the data is not available. 
+		 * If a list of responses is provided try to pick from the list, unless "Etc" is specified, which means it's open ended.
+		 */
+		private void CaptureVariable(OneOf<byte, Trigger> b)
+		{
+			// We could increment here based on having switched... Somehow?
+			// We need a better state tracking for this, to indicate the transition.
+			_currentVariable.Add(b.AsT0);
+		}
+
+		private void CaptureValue(OneOf<byte, Trigger> b)
+		{
+			// We could increment here based on having switched... Somehow?
+			// We need a better state tracking for this, to indicate the transition.
+			_currentVariable.Add(b.AsT0);
+		}
+
 		/// <summary>
 		/// Announce we do MSSP negotiation to the client.
 		/// </summary>

diff --git a/TelnetNegotiationCore/Models/State.cs b/TelnetNegotiationCore/Models/State.cs
@@ -19,6 +19,12 @@ public enum State : sbyte
 		DontMSSP,
 		WontMSSP,
 		WillMSSP,
+		AlmostNegotiatingMSSP,
+		EvaluatingMSSPVar,
+		EvaluatingMSSPVal,
+		EscapingMSSPVar,
+		EscapingMSSPVal,
+		CompletingMSSP,
 		#endregion MSSP Negotiation
 		#region Window Size Negotiation
 		WillDoNAWS,