/// <summary>
/// Initializes the LOC server instance.
/// </summary>
/// <param name="ProfileServer">Associated profile server.</param>
public LocServer(ProfileServer ProfileServer)
{
log = new Logger("NetworkSimulator.LocServer", "[" + ProfileServer.Name + "] ");
log.Trace("()");
this.profileServer = ProfileServer;
ipAddress = ProfileServer.IpAddress;
port = ProfileServer.LocPort;
nodeLocation = ProfileServer.NodeLocation;
listener = new TcpListener(ipAddress, port);
listener.Server.LingerState = new LingerOption(true, 0);
listener.Server.NoDelay = true;
log.Trace("(-)");
}
/// <summary>
/// Processes NeighbourhoodChangedNotificationRequest message from LOC server.
/// <para>Adds, changes, or deletes neighbor and possibly adds new neighborhood action to the database.</para>
/// </summary>
/// <param name="Client">TCP client who received the message.</param>
/// <param name="RequestMessage">Full request message.</param>
/// <returns>Response message to be sent to the client.</returns>
public async Task <LocProtocolMessage> ProcessMessageNeighbourhoodChangedNotificationRequestAsync(LocClient Client, LocProtocolMessage RequestMessage)
{
log.Trace("()");
LocProtocolMessage res = Client.MessageBuilder.CreateErrorInternalResponse(RequestMessage);
bool signalActionProcessor = false;
NeighbourhoodChangedNotificationRequest neighbourhoodChangedNotificationRequest = RequestMessage.Request.LocalService.NeighbourhoodChanged;
using (UnitOfWork unitOfWork = new UnitOfWork())
{
DatabaseLock[] lockObjects = new DatabaseLock[] { UnitOfWork.NeighborLock, UnitOfWork.NeighborhoodActionLock };
using (IDbContextTransaction transaction = await unitOfWork.BeginTransactionWithLockAsync(lockObjects))
{
bool success = false;
bool saveDb = false;
try
{
int neighborhoodSize = await unitOfWork.NeighborRepository.CountAsync();
foreach (NeighbourhoodChange change in neighbourhoodChangedNotificationRequest.Changes)
{
// We do ignore errors here for each individual change and just continue processing the next item from the list.
log.Trace("Neighborhood change type is {0}.", change.ChangeTypeCase);
switch (change.ChangeTypeCase)
{
case NeighbourhoodChange.ChangeTypeOneofCase.AddedNodeInfo:
case NeighbourhoodChange.ChangeTypeOneofCase.UpdatedNodeInfo:
{
bool isAdd = change.ChangeTypeCase == NeighbourhoodChange.ChangeTypeOneofCase.AddedNodeInfo;
NodeInfo nodeInfo = isAdd ? change.AddedNodeInfo : change.UpdatedNodeInfo;
// Check whether a proximity server is running on this node.
// If not, it is not interesting for us at all, skip it.
int proximityServerPort;
byte[] proximityServerId;
if (!HasProximityServerService(nodeInfo, out proximityServerPort, out proximityServerId))
{
break;
}
NodeContact contact = nodeInfo.Contact;
IPAddress ipAddress = new IPAddress(contact.IpAddress.ToByteArray());
Iop.Locnet.GpsLocation location = nodeInfo.Location;
int latitude = location.Latitude;
int longitude = location.Longitude;
AddOrChangeNeighborResult addChangeRes = await AddOrChangeNeighborAsync(unitOfWork, proximityServerId, ipAddress, proximityServerPort, latitude, longitude, neighborhoodSize);
neighborhoodSize = addChangeRes.NeighborhoodSize;
if (addChangeRes.SaveDb)
{
saveDb = true;
}
if (addChangeRes.SignalActionProcessor)
{
signalActionProcessor = true;
}
break;
}
case NeighbourhoodChange.ChangeTypeOneofCase.RemovedNodeId:
{
byte[] serverId = change.RemovedNodeId.ToByteArray();
bool serverIdValid = serverId.Length == ProtocolHelper.NetworkIdentifierLength;
if (!serverIdValid)
{
log.Error("Received invalid neighbor server ID '{0}' from LOC server.", serverId.ToHex());
break;
}
// Data processing.
Neighbor existingNeighbor = (await unitOfWork.NeighborRepository.GetAsync(n => n.NetworkId == serverId)).FirstOrDefault();
if (existingNeighbor != null)
{
log.Trace("Creating neighborhood action to deleting neighbor ID '{0}' from the database.", serverId.ToHex());
string neighborInfo = JsonConvert.SerializeObject(existingNeighbor);
// Delete neighbor completely.
// This will cause our proximity server to erase all activities of the neighbor that has been removed.
bool deleted = await unitOfWork.NeighborRepository.DeleteNeighborAsync(serverId, -1, true);
if (deleted)
{
// Add action that will contact the neighbor and ask it to stop sending updates.
// Note that the neighbor information will be deleted by the time this action
// is executed and this is why we have to fill in AdditionalData.
NeighborhoodAction stopUpdatesAction = new NeighborhoodAction()
{
ServerId = serverId,
Timestamp = DateTime.UtcNow,
Type = NeighborhoodActionType.StopNeighborhoodUpdates,
TargetActivityId = 0,
TargetActivityOwnerId = null,
ExecuteAfter = DateTime.UtcNow,
AdditionalData = neighborInfo
};
await unitOfWork.NeighborhoodActionRepository.InsertAsync(stopUpdatesAction);
signalActionProcessor = true;
saveDb = true;
}
else
{
log.Error("Failed to remove neighbor ID '{0}' from the database.", serverId.ToHex());
// This is actually bad, we failed to remove a record from the database, which should never happen.
// We try to insert action to remove this neighbor later, but adding the action might fail as well.
NeighborhoodAction action = new NeighborhoodAction()
{
ServerId = serverId,
Timestamp = DateTime.UtcNow,
Type = NeighborhoodActionType.RemoveNeighbor,
TargetActivityId = 0,
TargetActivityOwnerId = null,
AdditionalData = null
};
await unitOfWork.NeighborhoodActionRepository.InsertAsync(action);
signalActionProcessor = true;
saveDb = true;
}
}
else
{
log.Debug("Neighbor ID '{0}' not found, can not be removed.", serverId.ToHex());
// It can be the case that this node has not an associated proximity server, so in that case we should ignore it.
// If the node has an associated proximity server, then nothing bad really happens here if we have activities
// of such a neighbor in NeighborActivity table. Those entries will expire and will be deleted.
}
break;
}
default:
log.Error("Invalid neighborhood change type '{0}'.", change.ChangeTypeCase);
break;
}
}
if (saveDb)
{
await unitOfWork.SaveThrowAsync();
transaction.Commit();
}
success = true;
res = Client.MessageBuilder.CreateNeighbourhoodChangedNotificationResponse(RequestMessage);
}
catch (Exception e)
{
log.Error("Exception occurred: {0}", e.ToString());
}
if (!success)
{
log.Warn("Rolling back transaction.");
unitOfWork.SafeTransactionRollback(transaction);
}
unitOfWork.ReleaseLock(lockObjects);
}
}
if (signalActionProcessor)
{
NeighborhoodActionProcessor neighborhoodActionProcessor = (NeighborhoodActionProcessor)Base.ComponentDictionary[NeighborhoodActionProcessor.ComponentName];
neighborhoodActionProcessor.Signal();
}
log.Trace("(-):*.Response.Status={0}", res.Response.Status);
return(res);
}
