public static MSDU ParseMSDU(byte[] data)
{
MSDU msdu = new MSDU {
PrimaryHeader = data.Take(6).ToArray()
};
byte[] ob = data.Take(2).ToArray();
if (BitConverter.IsLittleEndian)
{
Array.Reverse(ob);
}
UInt16 o = BitConverter.ToUInt16(ob, 0);
msdu.Version = (o & 0xE000) >> 13;
msdu.Type = (o & 0x1000) >> 12;
msdu.HasSecondHeader = ((o & 0x800) >> 11) > 0;
msdu.APID = o & 0x7FF;
ob = data.Skip(2).Take(2).ToArray();
if (BitConverter.IsLittleEndian)
{
Array.Reverse(ob);
}
o = BitConverter.ToUInt16(ob, 0);
msdu.Sequence = (SequenceType)((o & 0xC000) >> 14);
msdu.PacketNumber = (o & 0x3FFF);
msdu.TemporaryFilename = $"{msdu.APID}.grbtmp";
ob = data.Skip(4).Take(2).ToArray();
if (BitConverter.IsLittleEndian)
{
Array.Reverse(ob);
}
msdu.PacketLength = BitConverter.ToUInt16(ob, 0) + 1;
data = data.Skip(6).ToArray();
if (data.Length > msdu.PacketLength)
{
msdu.RemainingData = data.Skip(msdu.PacketLength).ToArray();
data = data.Take(msdu.PacketLength).ToArray();
}
else
{
msdu.RemainingData = new byte[0];
}
msdu.Data = data.ToArray();
msdu.FrameLost = false;
return(msdu);
}
public void FinishMSDU(OpenSatelliteProject.GRB.MSDU msdu)
{
if (running)
{
if (packets.Count >= MAX_QUEUE_LENGTH)
{
OpenSatelliteProject.GRB.MSDU lmsdu;
UIConsole.Warn("MSDU Manager Queue is full!!!! Some MSDU might be discarded!");
packets.TryDequeue(out lmsdu);
}
packets.Enqueue(msdu);
}
}
void ProcessMSDU(OpenSatelliteProject.GRB.MSDU msdu)
{
try {
if (msdu.APID == 2047)
{
// Skip fill packet
return;
}
bool firstOrSinglePacket = msdu.Sequence == SequenceType.FIRST_SEGMENT || msdu.Sequence == SequenceType.SINGLE_DATA;
Packets++;
if (!msdu.Valid || !msdu.Full)
{
if (msdu.FrameLost)
{
UIConsole.Error($"Lost some frames on MSDU, the file will be corrupted. CRC Match: {msdu.Valid} - Size Match: {msdu.Full}");
}
else
{
UIConsole.Error($"Corrupted MSDU. CRC Match: {msdu.Valid} - Size Match: {msdu.Full}");
}
}
if (!msdu.Valid)
{
CRCFails++;
return;
}
var payloadType = EnumHelpers.APID2Type(msdu.APID);
if (msdu.Sequence == SequenceType.FIRST_SEGMENT || msdu.Sequence == SequenceType.SINGLE_DATA)
{
if (msduCache.ContainsKey(msdu.APID))
{
var minfo = msduCache[msdu.APID];
UIConsole.Warn($"Received First Segment for {msdu.APID:X3} but last data wasn't saved to disk yet! Forcing dump.");
// This can only happen for multi-segment file.
string msduFile = Path.Combine(FileHandler.TemporaryFileFolder, minfo.FileName);
string target = Path.Combine(FileHandler.TemporaryFileFolder, $"{msdu.APID:X3}-{LLTools.TimestampMS()}-{Tools.RandomString(8)}");
File.Move(msduFile, target);
if (payloadType == PayloadType.Generic)
{
fileHandleManager.NewFile(new Tuple <string, object>(target, minfo.GenericHeader));
}
else
{
fileHandleManager.NewFile(new Tuple <string, object>(target, minfo.ImageHeader));
}
msduCache.Remove(msdu.APID);
}
var msInfo = new MSDUInfo()
{
APID = msdu.APID,
FileName = msdu.TemporaryFilename,
GenericHeader = payloadType == PayloadType.Generic ? new GRBGenericHeader(msdu.APID, msdu.Data.Skip(8).Take(21).ToArray()) : null,
ImageHeader = payloadType == PayloadType.ImageData ? new GRBImageHeader(msdu.APID, msdu.Data.Skip(8).Take(34).ToArray()) : null,
};
msduCache.Add(msdu.APID, msInfo);
}
else if (msdu.Sequence == SequenceType.LAST_SEGMENT || msdu.Sequence == SequenceType.CONTINUED_SEGMENT)
{
if (!msduCache.ContainsKey(msdu.APID))
{
UIConsole.Warn("Orphan Packet!");
return;
}
}
var msduInfo = msduCache[msdu.APID];
msduInfo.Refresh();
string path = FileHandler.TemporaryFileFolder;
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
string filename = Path.Combine(FileHandler.TemporaryFileFolder, msduInfo.FileName);
int totalOffset;
if (firstOrSinglePacket)
{
totalOffset = 8;
if (payloadType == PayloadType.Generic)
{
totalOffset += 21;
}
else
{
totalOffset += 34;
}
}
else
{
totalOffset = 8;
}
byte[] dataToSave = msdu.Data.Skip(totalOffset).ToArray();
dataToSave = dataToSave.Take(dataToSave.Length - 4).ToArray(); // Remove CRC
using (FileStream fs = new FileStream(filename, firstOrSinglePacket ? FileMode.Create : FileMode.Append, FileAccess.Write)) {
using (BinaryWriter sw = new BinaryWriter(fs)) {
sw.Write(dataToSave);
sw.Flush();
}
}
if (msdu.Sequence == SequenceType.LAST_SEGMENT || msdu.Sequence == SequenceType.SINGLE_DATA)
{
string target = Path.Combine(FileHandler.TemporaryFileFolder, $"{msdu.APID:X3}-{LLTools.TimestampMS()}-{Tools.RandomString(8)}");
File.Move(filename, target);
if (payloadType == PayloadType.Generic)
{
fileHandleManager.NewFile(new Tuple <string, object>(target, msduInfo.GenericHeader));
}
else
{
fileHandleManager.NewFile(new Tuple <string, object>(target, msduInfo.ImageHeader));
}
msduCache.Remove(msdu.APID);
}
} catch (Exception e) {
UIConsole.Error(String.Format("Exception on FinishMSDU: {0}", e));
}
}