/**
* Implements the EdgeListener function to
* create edges of this type.
*/
public override void CreateEdgeTo(TransportAddress ta, EdgeCreationCallback ecb)
{
Edge e = null;
Exception ex = null;
if (!IsStarted)
{
ex = new EdgeException("UdpEdgeListener is not started");
}
else if (ta.TransportAddressType != this.TAType)
{
ex = new EdgeException(ta.TransportAddressType.ToString()
+ " is not my type: " + this.TAType.ToString());
}
else if (_ta_auth.Authorize(ta) == TAAuthorizer.Decision.Deny)
{
ex = new EdgeException(ta.ToString() + " is not authorized");
}
else
{
IPAddress first_ip = ((IPTransportAddress)ta).GetIPAddress();
IPEndPoint end = new IPEndPoint(first_ip, ((IPTransportAddress)ta).Port);
/* We have to keep our mapping of end point to edges up to date */
lock ( _id_ht ) {
//Get a random ID for this edge:
int id;
do
{
id = _rand.Next();
//Make sure we don't have negative ids
if (id < 0)
{
id = ~id;
}
} while(_id_ht.Contains(id) || id == 0);
e = new UdpEdge(this, false, end, _local_ep, id, 0);
_id_ht[id] = e;
}
NatDataPoint dp = new NewEdgePoint(DateTime.UtcNow, e);
Interlocked.Exchange <NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange <IEnumerable>(ref _nat_tas, new NatTAs(_tas, _nat_hist));
try {
/* Tell me when you close so I can clean up the table */
e.CloseEvent += this.CloseHandler;
} catch (Exception x) {
e = null;
ex = x;
}
}
if (e != null)
{
ecb(true, e, null);
}
else
{
ecb(false, null, ex);
}
}
protected void SendControlPacket(EndPoint end, int remoteid, int localid,
ControlCode c, object state)
{
using (MemoryStream ms = new MemoryStream()) {
NumberSerializer.WriteInt((int)c, ms);
if (c == ControlCode.EdgeDataAnnounce)
{
UdpEdge e = (UdpEdge)_id_ht[localid];
if ((e != null) && (e.RemoteID == remoteid))
{
Hashtable t = new Hashtable();
t["RemoteTA"] = e.RemoteTA.ToString();
t["LocalTA"] = e.LocalTA.ToString();
AdrConverter.Serialize(t, ms);
}
else
{
if (ProtocolLog.UdpEdge.Enabled)
{
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Problem sending EdgeData: EndPoint: {0}, remoteid: {1}, " +
"localid: {2}, Edge: {3}", end, remoteid, localid, e));
}
}
}
_send_queue.Enqueue(new UdpMessage(localid, ~remoteid, MemBlock.Reference(ms.ToArray()), end));
if (ProtocolLog.UdpEdge.Enabled)
{
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Sending control {1} to: {0}", end, c));
}
}
}
/**
* When a new Connection is added, we may need to update the list
* of TAs to make sure it is not too long, and that the it is sorted
* from most likely to least likely to be successful
* @param e the new Edge
* @param ta the TransportAddress our TA according to our peer
*/
public override void UpdateLocalTAs(Edge e, TransportAddress ta)
{
if (e.TAType == this.TAType)
{
UdpEdge ue = (UdpEdge)e;
ue.PeerViewOfLocalTA = ta;
NatDataPoint dp = new LocalMappingChangePoint(DateTime.UtcNow, e, ta);
Interlocked.Exchange <NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange <IEnumerable>(ref _nat_tas, new NatTAs(_tas, _nat_hist));
}
}
/**
* When UdpEdge objects call Send, it calls this packet callback:
*/
public void HandleEdgeSend(Edge from, ICopyable p)
{
if (_send_queue.Count > 1024)
{
Console.WriteLine("Send queue too big: " + _send_queue.Count);
// This may be causing the memory leak ... not certain
return;
// throw new EdgeException(true, "Could not send on: " + from);
}
UdpEdge edge = from as UdpEdge;
_send_queue.Enqueue(new UdpMessage(edge.ID, edge.RemoteID, p, edge.End));
}
/**
* When UdpEdge objects call Send, it calls this packet
* callback:
* @todo The previous interface did not throw an exception to a user
* since the send was called in another thread. All code that calls this
* could be updated to handle exceptions that the socket might throw.
*/
public void HandleEdgeSend(Edge from, ICopyable p)
{
UdpEdge sender = (UdpEdge)from;
lock (_send_sync) {
//Write the IDs of the edge:
//[local id 4 bytes][remote id 4 bytes][packet]
NumberSerializer.WriteInt(sender.ID, _send_buffer, 0);
NumberSerializer.WriteInt(sender.RemoteID, _send_buffer, 4);
int plength = p.CopyTo(_send_buffer, 8);
try {
_s.SendTo(_send_buffer, 8 + plength, SocketFlags.None, sender.End);
}
catch (Exception x) {
bool transient = (1 == _running);
throw new SendException(transient, String.Format("Problem sending on: {0}", sender), x);
}
}
}
/**
* When a UdpEdge closes we need to remove it from
* our table, so we will know it is new if it comes
* back.
*/
public void CloseHandler(object edge, EventArgs args)
{
UdpEdge e = (UdpEdge)edge;
lock ( _id_ht ) {
if (_id_ht.Contains(e.ID))
{
_id_ht.Remove(e.ID);
object re = _remote_id_ht[e.RemoteID];
if (re == e)
{
//_remote_id_ht only keeps track of incoming edges,
//so, there could be two edges with the same remoteid
//that are not equivalent.
_remote_id_ht.Remove(e.RemoteID);
}
NatDataPoint dp = new EdgeClosePoint(DateTime.UtcNow, e);
Interlocked.Exchange <NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange <IEnumerable>(ref _nat_tas, new NatTAs(_tas, _nat_hist));
}
}
}
/**
* Implements the EdgeListener function to
* create edges of this type.
*/
public override void CreateEdgeTo(TransportAddress ta, EdgeCreationCallback ecb)
{
Edge e = null;
Exception ex = null;
if( !IsStarted ) {
ex = new EdgeException("UdpEdgeListener is not started");
} else if( ta.TransportAddressType != this.TAType ) {
ex = new EdgeException(ta.TransportAddressType.ToString()
+ " is not my type: " + this.TAType.ToString() );
} else if( _ta_auth.Authorize(ta) == TAAuthorizer.Decision.Deny ) {
ex = new EdgeException( ta.ToString() + " is not authorized");
} else {
IPAddress first_ip = ((IPTransportAddress) ta).GetIPAddress();
IPEndPoint end = new IPEndPoint(first_ip, ((IPTransportAddress) ta).Port);
/* We have to keep our mapping of end point to edges up to date */
lock( _id_ht ) {
//Get a random ID for this edge:
int id;
do {
id = _rand.Next();
//Make sure we don't have negative ids
if( id < 0 ) { id = ~id; }
} while( _id_ht.Contains(id) || id == 0 );
e = new UdpEdge(this, false, end, _local_ep, id, 0);
_id_ht[id] = e;
}
NatDataPoint dp = new NewEdgePoint(DateTime.UtcNow, e);
Interlocked.Exchange<NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange<IEnumerable>(ref _nat_tas, new NatTAs( _tas, _nat_hist ));
try {
/* Tell me when you close so I can clean up the table */
e.CloseEvent += this.CloseHandler;
} catch (Exception x) {
e = null;
ex = x;
}
}
if(e != null) {
ecb(true, e, null);
} else {
ecb(false, null, ex);
}
}
/**
* This reads a packet from buf which came from end, with
* the given ids
*/
protected void HandleDataPacket(int remoteid, int localid,
MemBlock packet, EndPoint end, object state)
{
bool read_packet = true;
bool is_new_edge = false;
//It is threadsafe to read from Hashtable
UdpEdge edge = (UdpEdge)_id_ht[localid];
if( localid == 0 ) {
//This is a potentially a new incoming edge
is_new_edge = true;
//Check to see if it is a dup:
UdpEdge e_dup = (UdpEdge)_remote_id_ht[remoteid];
if( e_dup != null ) {
//Lets check to see if this is a true dup:
if( e_dup.End.Equals( end ) ) {
//Same id from the same endpoint, looks like a dup...
is_new_edge = false;
//Reuse the existing edge:
edge = e_dup;
}
else {
//This is just a coincidence.
}
}
if( is_new_edge ) {
TransportAddress rta = TransportAddressFactory.CreateInstance(this.TAType,(IPEndPoint)end);
if( _ta_auth.Authorize(rta) == TAAuthorizer.Decision.Deny ) {
//This is bad news... Ignore it...
///@todo perhaps we should send a control message... I don't know
is_new_edge= false;
read_packet = false;
if(ProtocolLog.UdpEdge.Enabled)
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Denying: {0}", rta));
}
else {
//We need to assign it a local ID:
lock( _id_ht ) {
/*
* Now we need to lock the table so that it cannot
* be written to by anyone else while we work
*/
do {
localid = _rand.Next();
//Make sure not to use negative ids
if( localid < 0 ) { localid = ~localid; }
} while( _id_ht.Contains(localid) || localid == 0 );
/*
* We copy the endpoint because (I think) .Net
* overwrites it each time. Since making new
* edges is rare, this is better than allocating
* a new endpoint each time
*/
IPEndPoint this_end = (IPEndPoint)end;
IPEndPoint my_end = new IPEndPoint(this_end.Address,
this_end.Port);
edge = new UdpEdge(_send_handler, true, my_end,
_local_ep, localid, remoteid);
_id_ht[localid] = edge;
_remote_id_ht[remoteid] = edge;
}
}
}
}
else if ( edge == null ) {
/*
* This is the case where the Edge is not a new edge,
* but we don't know about it. It is probably an old edge
* that we have closed. We can ignore this packet
*/
read_packet = false;
//Send a control packet
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
}
else if ( edge.RemoteID == 0 ) {
/* This is the response to our edge creation */
edge.RemoteID = remoteid;
}
else if( edge.RemoteID != remoteid ) {
/*
* This could happen as a result of packet loss or duplication
* on the first packet. We should ignore any packet that
* does not have both ids matching.
*/
read_packet = false;
//Tell the other guy to close this ignored edge
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
edge = null;
}
if( (edge != null) && !edge.End.Equals(end) ) {
//This happens when a NAT mapping changes
if(ProtocolLog.UdpEdge.Enabled)
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Remote NAT Mapping changed on Edge: {0}\n{1} -> {2}",
edge, edge.End, end));
//Actually update:
TransportAddress rta = TransportAddressFactory.CreateInstance(this.TAType,(IPEndPoint)end);
if( _ta_auth.Authorize(rta) != TAAuthorizer.Decision.Deny ) {
IPEndPoint this_end = (IPEndPoint) end;
edge.End = new IPEndPoint(this_end.Address, this_end.Port);
NatDataPoint dp = new RemoteMappingChangePoint(DateTime.UtcNow, edge);
Interlocked.Exchange<NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange<IEnumerable>(ref _nat_tas, new NatTAs( _tas, _nat_hist ));
//Tell the other guy:
SendControlPacket(end, remoteid, localid, ControlCode.EdgeDataAnnounce, state);
}
else {
/*
* Looks like the new TA is no longer authorized.
*/
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
RequestClose(edge);
CloseHandler(edge, null);
}
}
if( is_new_edge ) {
try {
NatDataPoint dp = new NewEdgePoint(DateTime.UtcNow, edge);
Interlocked.Exchange<NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange<IEnumerable>(ref _nat_tas, new NatTAs( _tas, _nat_hist ));
edge.CloseEvent += this.CloseHandler;
//If we make it here, the edge wasn't closed, go ahead and process it.
SendEdgeEvent(edge);
// Stun support
SendControlPacket(end, remoteid, localid, ControlCode.EdgeDataAnnounce, state);
}
catch {
//Make sure this edge is closed and we are done with it.
RequestClose(edge);
CloseHandler(edge, null);
read_packet = false;
//This was a new edge, so the other node has our id as zero, send
//with that localid:
SendControlPacket(end, remoteid, 0, ControlCode.EdgeClosed, state);
}
}
if( read_packet ) {
//We have the edge, now tell the edge to announce the packet:
try {
edge.ReceivedPacketEvent(packet);
}
catch(EdgeClosedException) {
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
//Make sure we record that this edge has been closed
CloseHandler(edge, null);
}
}
}
/**
* This reads a packet from buf which came from end, with
* the given ids
*/
protected void HandleDataPacket(int remoteid, int localid,
MemBlock packet, EndPoint end, object state)
{
bool read_packet = true;
bool is_new_edge = false;
//It is threadsafe to read from Hashtable
UdpEdge edge = (UdpEdge)_id_ht[localid];
if (localid == 0)
{
//This is a potentially a new incoming edge
is_new_edge = true;
//Check to see if it is a dup:
UdpEdge e_dup = (UdpEdge)_remote_id_ht[remoteid];
if (e_dup != null)
{
//Lets check to see if this is a true dup:
if (e_dup.End.Equals(end))
{
//Same id from the same endpoint, looks like a dup...
is_new_edge = false;
//Reuse the existing edge:
edge = e_dup;
}
else
{
//This is just a coincidence.
}
}
if (is_new_edge)
{
TransportAddress rta = TransportAddressFactory.CreateInstance(this.TAType, (IPEndPoint)end);
if (_ta_auth.Authorize(rta) == TAAuthorizer.Decision.Deny)
{
//This is bad news... Ignore it...
///@todo perhaps we should send a control message... I don't know
is_new_edge = false;
read_packet = false;
if (ProtocolLog.UdpEdge.Enabled)
{
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Denying: {0}", rta));
}
}
else
{
//We need to assign it a local ID:
lock ( _id_ht ) {
/*
* Now we need to lock the table so that it cannot
* be written to by anyone else while we work
*/
do
{
localid = _rand.Next();
//Make sure not to use negative ids
if (localid < 0)
{
localid = ~localid;
}
} while(_id_ht.Contains(localid) || localid == 0);
/*
* We copy the endpoint because (I think) .Net
* overwrites it each time. Since making new
* edges is rare, this is better than allocating
* a new endpoint each time
*/
IPEndPoint this_end = (IPEndPoint)end;
IPEndPoint my_end = new IPEndPoint(this_end.Address,
this_end.Port);
edge = new UdpEdge(_send_handler, true, my_end,
_local_ep, localid, remoteid);
_id_ht[localid] = edge;
_remote_id_ht[remoteid] = edge;
}
}
}
}
else if (edge == null)
{
/*
* This is the case where the Edge is not a new edge,
* but we don't know about it. It is probably an old edge
* that we have closed. We can ignore this packet
*/
read_packet = false;
//Send a control packet
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
}
else if (edge.RemoteID == 0)
{
/* This is the response to our edge creation */
edge.RemoteID = remoteid;
}
else if (edge.RemoteID != remoteid)
{
/*
* This could happen as a result of packet loss or duplication
* on the first packet. We should ignore any packet that
* does not have both ids matching.
*/
read_packet = false;
//Tell the other guy to close this ignored edge
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
edge = null;
}
if ((edge != null) && !edge.End.Equals(end))
{
//This happens when a NAT mapping changes
if (ProtocolLog.UdpEdge.Enabled)
{
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Remote NAT Mapping changed on Edge: {0}\n{1} -> {2}",
edge, edge.End, end));
}
//Actually update:
TransportAddress rta = TransportAddressFactory.CreateInstance(this.TAType, (IPEndPoint)end);
if (_ta_auth.Authorize(rta) != TAAuthorizer.Decision.Deny)
{
IPEndPoint this_end = (IPEndPoint)end;
edge.End = new IPEndPoint(this_end.Address, this_end.Port);
NatDataPoint dp = new RemoteMappingChangePoint(DateTime.UtcNow, edge);
Interlocked.Exchange <NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange <IEnumerable>(ref _nat_tas, new NatTAs(_tas, _nat_hist));
//Tell the other guy:
SendControlPacket(end, remoteid, localid, ControlCode.EdgeDataAnnounce, state);
}
else
{
/*
* Looks like the new TA is no longer authorized.
*/
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
RequestClose(edge);
CloseHandler(edge, null);
}
}
if (is_new_edge)
{
try {
NatDataPoint dp = new NewEdgePoint(DateTime.UtcNow, edge);
Interlocked.Exchange <NatHistory>(ref _nat_hist, _nat_hist + dp);
Interlocked.Exchange <IEnumerable>(ref _nat_tas, new NatTAs(_tas, _nat_hist));
edge.CloseEvent += this.CloseHandler;
//If we make it here, the edge wasn't closed, go ahead and process it.
SendEdgeEvent(edge);
// Stun support
SendControlPacket(end, remoteid, localid, ControlCode.EdgeDataAnnounce, state);
}
catch {
//Make sure this edge is closed and we are done with it.
RequestClose(edge);
CloseHandler(edge, null);
read_packet = false;
//This was a new edge, so the other node has our id as zero, send
//with that localid:
SendControlPacket(end, remoteid, 0, ControlCode.EdgeClosed, state);
}
}
if (read_packet)
{
//We have the edge, now tell the edge to announce the packet:
try {
edge.ReceivedPacketEvent(packet);
}
catch (EdgeClosedException) {
SendControlPacket(end, remoteid, localid, ControlCode.EdgeClosed, state);
//Make sure we record that this edge has been closed
CloseHandler(edge, null);
}
}
}
/**
* This handles lightweight control messages that may be sent
* by UDP
*/
protected void HandleControlPacket(int remoteid, int n_localid,
MemBlock buffer, object state)
{
int local_id = ~n_localid;
UdpEdge e = _id_ht[local_id] as UdpEdge;
if (e == null)
{
return;
}
if (e.RemoteID == 0)
{
try {
e.RemoteID = remoteid;
} catch {
return;
}
}
if (e.RemoteID != remoteid)
{
return;
}
try {
ControlCode code = (ControlCode)NumberSerializer.ReadInt(buffer, 0);
if (ProtocolLog.UdpEdge.Enabled)
{
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Got control {1} from: {0}", e, code));
}
if (code == ControlCode.EdgeClosed)
{
//The edge has been closed on the other side
RequestClose(e);
CloseHandler(e, null);
}
else if (code == ControlCode.EdgeDataAnnounce)
{
//our NAT mapping may have changed:
IDictionary info =
(IDictionary)AdrConverter.Deserialize(buffer.Slice(4));
string our_local_ta = (string)info["RemoteTA"]; //his remote is our local
if (our_local_ta != null)
{
//Update our list:
TransportAddress new_ta = TransportAddressFactory.CreateInstance(our_local_ta);
TransportAddress old_ta = e.PeerViewOfLocalTA;
if (!new_ta.Equals(old_ta))
{
if (ProtocolLog.UdpEdge.Enabled)
{
ProtocolLog.Write(ProtocolLog.UdpEdge, String.Format(
"Local NAT Mapping changed on Edge: {0}\n{1} => {2}",
e, old_ta, new_ta));
}
//Looks like matters have changed:
this.UpdateLocalTAs(e, new_ta);
/**
* @todo, maybe we should ping the other edges sharing this
* EndPoint, but we need to be careful not to do some O(E^2)
* operation, which could easily happen if each EdgeDataAnnounce
* triggered E packets to be sent
*/
}
}
}
else if (code == ControlCode.Null)
{
//Do nothing in this case
}
}
catch (Exception x) {
//This could happen if this is some control message we don't understand
if (ProtocolLog.Exceptions.Enabled)
{
ProtocolLog.Write(ProtocolLog.Exceptions, x.ToString());
}
}
}
