private void Send_IAC(IAC command, Byte option)
{
Debug.WriteLine("Send IAC {0} {1} (255 {2:D0} {3:D0})", command, (Telnet.Option)option, (Byte)command, option);
Byte[] buf = new Byte[3];
buf[0] = (Byte)IAC.IAC;
buf[1] = (Byte)command;
buf[2] = option;
_Send(buf, 0, 3);
}
public static Token NOP(IAC command)
{
Byte[] buf = new Byte[1];
buf[0] = (Byte)command;
return(new Token(TokenType.NOP, buf, 0, 1));
}
private Token GetToken(ref Int32 p, Byte[] buffer, ref Int32 q)
{
Int32 op = p; // original value of index into mRecvBuf
Int32 oq = q; // original value of index into buffer
Int32 state = 0;
Int32 n;
while ((n = PeekTokenByte(p, buffer, q)) != -1)
{
IAC b = (IAC)n;
switch (state)
{
case 0: // start
if (b == IAC.IAC)
{
state = 3;
}
else if (n == '\r')
{
state = 2;
}
else
{
state = 1;
}
ReadTokenByte(ref p, buffer, ref q);
break;
case 1: // data
if ((b == IAC.IAC) || (n == '\r'))
{
return(new Token(TokenType.Data, buffer, oq, q - oq));
}
ReadTokenByte(ref p, buffer, ref q);
break;
case 2: // CR
if ((n == '\n') || (n == 0))
{
ReadTokenByte(ref p, buffer, ref q);
if ((mRecvBuf != null) && (p == mRecvBuf.Length) && (p != op) && (q != oq))
{
// recopy if this token was split across 2 buffers
n = (p - op) + (q - oq);
Byte[] buf = new Byte[n];
n = 0;
for (Int32 i = op; i < p; i++)
{
buf[n++] = mRecvBuf[i];
}
for (Int32 i = oq; i < q; i++)
{
buf[n++] = buffer[i];
}
return(new Token(TokenType.Data, buf, 0, n));
}
return(new Token(TokenType.Data, buffer, oq, q - oq));
}
if (q == oq)
{
return(new Token(TokenType.Data, mRecvBuf, op, p - op));
}
return(new Token(TokenType.Data, buffer, oq, q - oq));
case 3: // IAC
if (b == IAC.IAC)
{
Token t = (q == oq) ? new Token(TokenType.Data, mRecvBuf, op, 1) : new Token(TokenType.Data, buffer, oq, 1);
ReadTokenByte(ref p, buffer, ref q);
return(t);
}
if ((b == IAC.GA) || (b == IAC.BRK) || (b == IAC.IP) || (b == IAC.AO) || (b == IAC.AYT) || (b == IAC.EC) || (b == IAC.EL) || (b == IAC.EOR) || (b == IAC.EOF) || (b == IAC.SUSP) || (b == IAC.ABORT))
{
ReadTokenByte(ref p, buffer, ref q);
return(new Token(TokenType.Command, buffer, q - 1, 1));
}
if (b == IAC.DM)
{
ReadTokenByte(ref p, buffer, ref q);
if (q == oq)
{
return(new Token(TokenType.DM, mRecvBuf, p - 1, 1));
}
return(new Token(TokenType.DM, buffer, q - 1, 1));
}
ReadTokenByte(ref p, buffer, ref q);
if (b == IAC.DO)
{
state = 4;
}
else if (b == IAC.DONT)
{
state = 5;
}
else if (b == IAC.WILL)
{
state = 6;
}
else if (b == IAC.WONT)
{
state = 7;
}
else if (b == IAC.SB)
{
state = 8;
}
else if (q == oq)
{
return(new Token(TokenType.NOP, mRecvBuf, p - 1, 1));
}
else
{
return(new Token(TokenType.NOP, buffer, q - 1, 1));
}
break;
case 4: // IAC DO
ReadTokenByte(ref p, buffer, ref q);
return(new Token(TokenType.DO, buffer, q - 1, 1));
case 5: // IAC DONT
ReadTokenByte(ref p, buffer, ref q);
return(new Token(TokenType.DONT, buffer, q - 1, 1));
case 6: // IAC WILL
ReadTokenByte(ref p, buffer, ref q);
return(new Token(TokenType.WILL, buffer, q - 1, 1));
case 7: // IAC WONT
ReadTokenByte(ref p, buffer, ref q);
return(new Token(TokenType.WONT, buffer, q - 1, 1));
case 8: // IAC SB
ReadTokenByte(ref p, buffer, ref q);
state = 9;
break;
case 9: // IAC SB OPT ...
if (b == IAC.IAC)
{
state = 10;
}
ReadTokenByte(ref p, buffer, ref q);
break;
case 10: // IAC SB OPT ... IAC
ReadTokenByte(ref p, buffer, ref q);
if (b == IAC.SE)
{
if ((mRecvBuf != null) && (p == mRecvBuf.Length) && (p != op) && (q != oq))
{
// recopy if this token was split across 2 buffers
n = (p - op) + (q - oq);
Byte[] buf = new Byte[n];
n = 0;
for (Int32 i = op; i < p; i++)
{
buf[n++] = mRecvBuf[i];
}
for (Int32 i = oq; i < q; i++)
{
buf[n++] = buffer[i];
}
return(new Token(TokenType.SB, buf, 2, n - 4));
}
return(new Token(TokenType.SB, buffer, oq + 2, q - oq - 4));
}
if (b == IAC.IAC)
{
state = 11;
}
else
{
state = 9;
}
break;
case 11: // IAC SB OPT ... IAC IAC ...
if (b == IAC.IAC)
{
state = 12;
}
ReadTokenByte(ref p, buffer, ref q);
break;
case 12: // IAC SB OPT ... IAC IAC ... IAC
ReadTokenByte(ref p, buffer, ref q);
if (b == IAC.SE)
{
if ((mRecvBuf != null) && (p == mRecvBuf.Length) && (p != op) && (q != oq))
{
// recopy if this token was split across 2 buffers (undoubling IACs)
n = (p - op) + (q - oq);
Byte[] buf = new Byte[n];
n = 0;
for (Int32 i = op; i < p; i++)
{
buf[n++] = mRecvBuf[i];
}
for (Int32 i = oq; i < q; i++)
{
buf[n++] = buffer[i];
}
for (Int32 i = 0; i < n; i++)
{
if (buf[i] != (Byte)IAC.IAC)
{
continue;
}
if (buf[i] == buf[i + 1])
{
n--;
for (Int32 j = i; j < n; j++)
{
buf[j] = buf[j + 1];
}
}
}
return(new Token(TokenType.SB, buf, 2, n - 4));
}
// undouble embedded IACs
n = q;
for (Int32 i = oq; i < n; i++)
{
if (buffer[i] != (Byte)IAC.IAC)
{
continue;
}
if (buffer[i] == buffer[i + 1])
{
n--;
for (Int32 j = i; j < n; j++)
{
buffer[j] = buffer[j + 1];
}
}
}
return(new Token(TokenType.SB, buffer, oq + 2, n - oq - 4));
}
state = 11;
break;
}
}
if (state == 0)
{
return(new Token(TokenType.None, null, 0, 0));
}
if (state == 1)
{
return(new Token(TokenType.Data, buffer, oq, q - oq));
}
return(new Token(TokenType.Invalid, null, 0, 0));
}
private void Send_IAC(IAC command)
{
Send_IAC((Byte)command);
}
