public override bool ProcessPDU(LLCP_Link link, LLCP_PDU recv_pdu)
{
/* Server action */
/* ------------- */
link.RemotePort = recv_pdu.SSAP;
link.LocalPort = (byte)(_server_port & 0x3F);
switch (recv_pdu.PTYPE)
{
case LLCP_PDU.PTYPE_CONNECT:
Trace.WriteLine("> CONNECT");
/* The client wants to connect us */
link.State = LLCP_Link.StateActive;
if (!OnConnect(link, recv_pdu.Payload))
{
/* Failed */
link.Send_DM(LLCP_DM_PDU.REASON_REJECTED); /* 03 */
/* Drop the link */
return(false);
}
else
if (!link.Answered)
{
/* Confirm we agree (CC) */
link.Send_CC();
}
break;
case LLCP_PDU.PTYPE_DISC:
Trace.WriteLine("> DISC");
/* The client is leaving us */
if (link.State == LLCP_Link.StateActive)
{
OnDisconnect(link);
link.Send_DM(LLCP_DM_PDU.REASON_DISC_OK); /* 00 */
}
else
{
link.Send_DM(LLCP_DM_PDU.REASON_NO_CONNECTION); /* 01 */
}
/* Drop the link */
return(false);
case LLCP_PDU.PTYPE_I:
Trace.WriteLine("> I");
/* The client is talking to us */
if (link.State == LLCP_Link.StateActive)
{
byte nr = (byte)(recv_pdu.Sequence & 0x0F);
byte ns = (byte)((recv_pdu.Sequence >> 4) & 0x0F);
link.SetRemoteSequence((byte)((ns + 1) & 0x0F));
OnInformation(link, recv_pdu.Payload);
if (!link.Answered)
{
/* No frame -> ACK */
link.Send_RR();
}
}
else
{
link.Send_DM(LLCP_DM_PDU.REASON_NO_CONNECTION); /* 01 */
}
break;
case LLCP_PDU.PTYPE_RR:
Trace.WriteLine("> RR");
/* The client is acknowledging */
if (link.State == LLCP_Link.StateActive)
{
byte nr = (byte)(recv_pdu.Sequence & 0x0F);
OnAcknowledge(link);
}
else
{
link.Send_DM(LLCP_DM_PDU.REASON_NO_CONNECTION); /* 01 */
}
break;
default:
Trace.WriteLine("Unsupported LLCP frame client->server");
link.Send_FRMR(0x80, recv_pdu.PTYPE, 0x00);
/* Drop the link */
return(false);
}
/* Keep the link OK */
return(true);
}
protected bool HandleRecvPDU(LLCP_PDU recv_pdu)
{
LLCP_Link link;
if ((recv_pdu.DSAP == 0) && (recv_pdu.SSAP == 0))
{
/* Management PDUs */
/* --------------- */
return(HandleManagementPDU(recv_pdu));
}
SymmCount = 0;
if (recv_pdu.PTYPE == LLCP_PDU.PTYPE_CONNECT)
{
/* Handle CONNECT */
/* -------------- */
Trace.WriteLine("> CONNECT");
/* Name server is listening on address 01 */
if (recv_pdu.DSAP == ADDR_NAME_SERVER)
{
/* Using name server */
string server_name = FindParameterStr(recv_pdu.Payload, LLCP.PARAM_SERVICE_NAME);
if (server_name != null)
{
Trace.WriteLine("Looking for server '" + server_name + "'");
/* Looking for a server by its name */
for (int i = 0; i < _servers.Count; i++)
{
if (_servers[i].ServerName == server_name)
{
link = new LLCP_Link(this, _servers[i], recv_pdu);
link.LocalPort = _servers[i].ServerPort;
if (link.ProcessPDU(recv_pdu))
{
_links.Add(link);
}
return(true);
}
}
}
}
else
{
/* Using server address */
Trace.WriteLine("Looking for server " + recv_pdu.DSAP);
for (int i = 0; i < _servers.Count; i++)
{
if (_servers[i].ServerPort == recv_pdu.DSAP)
{
link = new LLCP_Link(this, _servers[i], recv_pdu);
if (link.ProcessPDU(recv_pdu))
{
_links.Add(link);
}
return(true);
}
}
}
}
/* Looking for an already-connected Server, or already instancied Client */
/* --------------------------------------------------------------------- */
for (int i = 0; i < _links.Count; i++)
{
if (_links[i].LocalPort == recv_pdu.DSAP)
{
if (!_links[i].ProcessPDU(recv_pdu))
{
/* Drop the link */
_links.RemoveAt(i);
}
return(true);
}
}
/* No client, no server, and DSAP or SSAP != 0 */
link = new LLCP_Link(this, null, recv_pdu);
switch (recv_pdu.PTYPE)
{
case LLCP_PDU.PTYPE_CONNECT:
/* Peer is trying to connect to a non-existing service */
Trace.WriteLine("CONNECT to non existing server");
link.Send_DM(LLCP_DM_PDU.REASON_NO_SERVICE);
break;
case LLCP_PDU.PTYPE_RR:
case LLCP_PDU.PTYPE_I:
Trace.WriteLine("I or RR to non active service");
link.Send_DM(LLCP_DM_PDU.REASON_NO_CONNECTION); /* 01 */
break;
default:
Trace.WriteLine("No client, no server, bad PTYPE");
break;
}
return(true);
}
