private static void AddTunnelMessage(List <TunnelMessage> result, TunnelDataFragment initialfragment, byte[] buf)
{
switch (initialfragment.Delivery)
{
case TunnelMessage.DeliveryTypes.Local:
result.Add(new TunnelMessageLocal(I2NPMessage.ReadHeader16(new BufRef(buf))));
break;
case TunnelMessage.DeliveryTypes.Router:
result.Add(new TunnelMessageRouter(I2NPMessage.ReadHeader16(new BufRef(buf)),
new I2PIdentHash((BufRefLen)initialfragment.ToHash)));
break;
case TunnelMessage.DeliveryTypes.Tunnel:
result.Add(new TunnelMessageTunnel(I2NPMessage.ReadHeader16(new BufRef(buf)),
new I2PIdentHash((BufRefLen)initialfragment.ToHash), initialfragment.Tunnel));
break;
}
}
public IEnumerable <TunnelMessage> Process(IEnumerable <TunnelDataMessage> tdmsgs)
{
var result = new List <TunnelMessage>();
RemoveUnmatchedFragments.Do(() =>
{
lock ( MessageFragments )
{
var remove = MessageFragments.Where(p => p.Value.Created.DeltaToNow.ToMinutes > RememberUnmatchedFragmentsForMinutes).
Select(p => p.Key).ToArray();
foreach (var key in remove)
{
Logging.LogDebug("TunnelDataFragmentReassembly: Removing old unmatched fragment for " + key.ToString());
MessageFragments.Remove(key);
}
}
});
foreach (var msg in tdmsgs)
{
var hash = I2PHashSHA256.GetHash(msg.TunnelDataPayload, msg.IV);
var eq = BufUtils.Equal(msg.Checksum.PeekB(0, 4), 0, hash, 0, 4);
if (!eq)
{
// Do not stop processing, just throw away faulty data
// throw new SignatureCheckFailureException( "TunnelDataFragmentReassembly: SHA256 check failed in TunnelData" );
Logging.LogDebug("TunnelDataFragmentReassembly: SHA256 check failed in TunnelData");
continue;
}
var reader = (BufRefLen)msg.TunnelDataPayload;
while (reader.Length > 0)
{
var frag = new TunnelDataFragment(reader);
if (frag.FollowOnFragment)
{
List <TunnelDataFragment> fragments;
if (!MessageFragments.ContainsKey(frag.MessageId))
{
fragments = new List <TunnelDataFragment>();
MessageFragments[frag.MessageId] = new TunnelDataFragmentList(fragments);
}
else
{
fragments = MessageFragments[frag.MessageId].List;
}
if (fragments.Count <= frag.FragmentNumber)
{
fragments.AddRange(new TunnelDataFragment[frag.FragmentNumber - fragments.Count + 1]);
}
fragments[frag.FragmentNumber] = frag;
CheckForAllFragmentsFound(result, frag.MessageId, fragments);
}
else
{
if (frag.Fragmented)
{
List <TunnelDataFragment> fragments;
if (!MessageFragments.ContainsKey(frag.MessageId))
{
fragments = new List <TunnelDataFragment>();
MessageFragments[frag.MessageId] = new TunnelDataFragmentList(fragments);
}
else
{
fragments = MessageFragments[frag.MessageId].List;
}
if (fragments.Count == 0)
{
fragments.AddRange(new TunnelDataFragment[1]);
}
fragments[0] = frag;
CheckForAllFragmentsFound(result, frag.MessageId, fragments);
}
else
{
AddTunnelMessage(result, frag, frag.Payload.ToByteArray());
}
}
}
}
return(result);
}