public static void SendISBeacon()
{
APRSIS.SendData(MiniGate.FullCall + ">" + MiniGate.MiniGateDest + ",TCPIP*:" + BText + " " + Toolbox.GetVin() + "\r\n");
}
private static void Parse() // Where most of the packet decoding magic happens
{
if (bytes > 17) // If the packet is less than 18 bytes, it's obviously broken, so don't even bother.
{
ushort CalcFCS = 0xFFFF; // We will check the FCS before going on
for (int i = 0; i < (bytes - 2); i++) // Loop thru all bytes in the packet except the FCS field
{
byte inbyte = indata[i];
for (int k = 0; k < 8; k++) // Loop thru all 8 bits in this byte
{
bool inbit = ((inbyte & 0x01) == 0x01); // Grab the LSB of the current byte
bool fcsbit = ((CalcFCS & 0x0001) == 0x0001); // Grab the LSB of the current FCS value
CalcFCS >>= 1; // Shift the current FCS value one bit right
if (fcsbit != inbit)
{
CalcFCS = (ushort)(CalcFCS ^ 0x8408); // If the LSB of this byte and the bit that was shifted off the FCS don't match, XOR the FCS with 0x8408
}
inbyte >>= 1; // Shift this byte right to get ready for the next bit
}
}
CalcFCS = (ushort)(CalcFCS ^ 0xFFFF); // XOR The FCS with 0xFFFF
if ((indata[bytes - 1] == (CalcFCS >> 8)) && (indata[bytes - 2] == (CalcFCS & 0xFF)))
{
int NumCalls = 0;
byte[][] Callsigns = new byte[10][];
byte[] SSIDs = new byte[10];
bool[] HBit = new bool[10];
string Via = "";
for (int i = 0; i <= 9; i++)
{
Callsigns[i] = new byte[6]; // Initialize "jagged" callsign array
}
for (int a = 0; a <= 9; a++) // Loop through up to 10 callsigns in the address field
{
NumCalls++;
for (int i = 0; i <= 5; i++)
{
Callsigns[a][i] = (byte)(indata[((a * 7) + i)] >> 1); // Get the byte for each letter of this call, and shift it right one bit
}
SSIDs[a] = (byte)((indata[((a + 1) * 7) - 1] & 0x1E) >> 1); // Get the SSID of this call (bits 4-1 of the last octect of this call)
HBit[a] = ((indata[((a + 1) * 7) - 1] & 0x80) == 0x80); // See if the "H bit" of this SSID octet is set (indicates if this digi slot has been used)
if ((indata[((a + 1) * 7) - 1] & 0x01) == 0x01)
{
break; // Exit the loop if this is the last call in the address field
}
}
if ((indata[NumCalls * 7] == 0x03) && (indata[(NumCalls * 7) + 1] == 0xF0)) // Don't bother going on if this isn't a UI packet
{ // We'd check this sooner, but need to know where these bytes are in the packet first
if (NumCalls > 2)
{
Via = ",";
for (int i = 2; i < NumCalls; i++)
{
string Callsign = new String(Toolbox.Bytes2Chars(Callsigns[i]));
Via = Via + Callsign.Trim();
if (SSIDs[i] != 0x00)
{
Via = Via + "-" + SSIDs[i].ToString(); // Only add the SSID if it's not zero
}
if (HBit[i])
{
Via = Via + "*"; // Add a "*" if this digi slot has been used
}
if ((i + 1) < NumCalls)
{
Via = Via + ","; // Add a "," if there are more digi's in the list
}
}
}
string Source = new String(Toolbox.Bytes2Chars(Callsigns[1]));
Source = Source.Trim();
if (SSIDs[1] != 0x00)
{
Source = Source + "-" + SSIDs[1].ToString();
}
string Dest = new String(Toolbox.Bytes2Chars(Callsigns[0]));
Dest = Dest.Trim();
if (SSIDs[0] != 0x00)
{
Dest = Dest + "-" + SSIDs[0].ToString();
}
string Payload = new String(Toolbox.Bytes2Chars(Utility.ExtractRangeFromArray(indata, (NumCalls * 7) + 2, bytes - (NumCalls * 7) - 4)));
if (Via.IndexOf("TCPIP") == -1 && Via.IndexOf("TCPXX") == -1)
{
APRSIS.SendData(Source + ">" + Dest + Via + ",qAR," + MiniGate.FullCall + ":" + Payload + "\r\n");
}
if (TelnetServer.RFMonEnable)
{
TelnetServer.SendData(Source + ">" + Dest + Via + ":" + Payload + "\r\n");
}
}
}
}
Array.Clear(indata, 0, bytes + 1);
bytes = 0;
}