void Receive_Ping(G2ReceivedPacket packet)
{
Core.ServiceBandwidth[Core.DhtServiceID].InPerSec += packet.Root.Data.Length;
Ping ping = Ping.Decode(packet);
bool lanIP = Utilities.IsLocalIP(packet.Source.IP);
bool validSource = (!lanIP || LanMode && lanIP);
// set local IP
SetLocalIP(ping.RemoteIP, packet);
// check loop back
if (ping.Source != null && Local.Equals(ping.Source))
{
if (packet.ReceivedTcp)
{
packet.Tcp.CleanClose("Loopback connection");
}
return;
}
// dont send back pong if received tunneled and no longer need to use lookup proxies
// remote would only send tunneled ping if UseGlobalProxies published info on network
// let our lookup address expire from remote's routing table
if (packet.Tunneled && !UseLookupProxies)
{
return;
}
// setup pong reply
Pong pong = new Pong();
if (ping.Source != null)
{
pong.Source = GetLocalSource();
}
if (ping.RemoteIP != null)
{
pong.RemoteIP = packet.Source.IP;
}
if (!IsLookup && Core.Context.SignedUpdate != null && Core.Context.SignedUpdate.Loaded)
{
pong.Version = Core.Context.SignedUpdate.SequentialVersion;
}
int sentBytes = 0;
// received tcp
if (packet.ReceivedTcp)
{
if (ping.Source == null)
{
packet.Tcp.SendPacket(pong);
return;
}
if (validSource)
{
if (ping.Source.Firewall == FirewallType.Open)
{
Routing.Add(new DhtContact(ping.Source, packet.Source.IP));
}
// received incoming tcp means we are not firewalled
if (!packet.Tcp.Outbound)
{
// done here to prevent setting open for loopback tcp connection
Core.SetFirewallType(FirewallType.Open);
pong.Source.Firewall = FirewallType.Open;
}
}
// check if already connected
if (packet.Tcp.Proxy == ProxyType.Unset && TcpControl.GetProxy(ping.Source) != null)
{
packet.Tcp.CleanClose("Dupelicate Connection");
return;
}
packet.Tcp.UserID = ping.Source.UserID;
packet.Tcp.ClientID = ping.Source.ClientID;
packet.Tcp.TcpPort = ping.Source.TcpPort;
packet.Tcp.UdpPort = ping.Source.UdpPort;
// if inbound connection, to our open host, and haven't checked fw yet
if (!packet.Tcp.Outbound &&
ping.Source.Firewall != FirewallType.Open &&
!packet.Tcp.CheckedFirewall)
{
TcpControl.MakeOutbound(packet.Source, ping.Source.TcpPort, "check firewall");
packet.Tcp.CheckedFirewall = true;
}
pong.Direct = true;
sentBytes = packet.Tcp.SendPacket(pong);
// dont send close if proxies maxxed yet, because their id might be closer than current proxies
}
// ping received udp or tunneled
else
{
if (validSource)
{
// received udp traffic, we must be behind a NAT at least
if (Core.Firewall == FirewallType.Blocked && !packet.Tunneled)
{
Core.SetFirewallType(FirewallType.NAT);
}
Routing.TryAdd(packet, ping.Source);
}
// if received over lan, the port isn't set
if (packet.Source.UdpPort == 0)
{
packet.Source.UdpPort = ping.Source.UdpPort;
}
// send pong
sentBytes = SendPacket(packet.Source, pong);
}
Core.ServiceBandwidth[Core.DhtServiceID].OutPerSec += sentBytes;
}