/* Instance management */
public void Read(BinaryReader br)
{
name = DNS.ReadName(br);
qtype = br.ReadUInt16();
qclass = br.ReadUInt16();
ntoh();
}
public void Write(BinaryWriter bw)
{
hton();
DNS.WriteName(bw, name);
bw.Write(qtype);
bw.Write(qclass);
ntoh();
}
/* Instance management */
public void Read(BinaryReader br)
{
name = DNS.ReadName(br);
atype = br.ReadUInt16();
aclass = br.ReadUInt16();
ttl = br.ReadUInt32();
rdlen = br.ReadUInt16();
ntoh();
rdata = br.ReadBytes((int)rdlen);
}
public void Write(BinaryWriter bw)
{
hton();
DNS.WriteName(bw, name);
bw.Write(atype);
bw.Write(aclass);
bw.Write(ttl);
bw.Write(rdlen);
ntoh();
bw.Write(rdata, 0, (int)rdlen);
}
public static bool resolve(string name, ref byte[] address)
{
IPEndPoint broadcast_ep = new IPEndPoint(IPAddress.Parse("255.255.255.255"), 15000);
UdpClient client = new UdpClient();
client.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
client.Client.ExclusiveAddressUse = false;
MemoryStream ms = new MemoryStream();
BinaryWriter bw = new BinaryWriter(ms);
Random r = new Random();
UInt32 id = (UInt32)r.Next();
bw.Write(id);
bw.Write((byte)1); // isRequest
DNS.WriteName(bw, name);
byte[] packet = ms.ToArray();
client.Send(packet, packet.Length, broadcast_ep);
ArrayList packets = new ArrayList();
client.Client.ReceiveTimeout = 10;
try
{
while (true)
{
IPEndPoint recv_ipep = new IPEndPoint(IPAddress.Any, _P2P_PORT);
byte[] packet_recv = client.Receive(ref recv_ipep);
#if DEBUG
Console.WriteLine("Received P2P from {0}", recv_ipep.ToString());
#endif
if (packet_recv.Length < 6)
{
continue;
}
MemoryStream ms_r = new MemoryStream(packet_recv);
BinaryReader br = new BinaryReader(ms_r);
UInt32 id_r = br.ReadUInt32();
if (id_r == id)
{
if (br.ReadByte() == 0)
{
packets.Add(packet_recv);
}
}
}
} catch (SocketException ex)
{
}
// If no information was received, fail early
if (packets.Count < 1)
{
return(false);
}
// Collate received addresses
Dictionary <byte[], int> addresses = new Dictionary <byte[], int>();
foreach (byte[] buf in packets)
{
MemoryStream ms_b = new MemoryStream(buf);
BinaryReader br = new BinaryReader(ms_b);
// Skip ID, we already checked this
br.ReadUInt32();
// Skip isRequest, we already checked this
br.ReadByte();
byte exists = br.ReadByte();
UInt32 ttl = br.ReadUInt32();
byte[] addr = br.ReadBytes(4);
if (exists == 0)
{
addr = new byte[] { 0, 0, 0, 0 };
}
if (addresses.ContainsKey(addr))
{
addresses[addr]++;
}
else
{
addresses.Add(addr, 1);
}
}
// Choose most likely address based on which was reported the most
byte[] addr_picked = null;
int max = 0;
foreach (KeyValuePair <byte[], int> kvp in addresses)
{
if (kvp.Value > max)
{
addr_picked = kvp.Key;
}
}
if (addr_picked.Equals(new byte[] { 0, 0, 0, 0 }))
{
return(false);
}
address = addr_picked;
return(true);
}
public static void Run()
{
UdpClient udpClient = new UdpClient();
udpClient.EnableBroadcast = true;
IPEndPoint recv_groupep = new IPEndPoint(IPAddress.Any, _P2P_PORT);
udpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
udpClient.ExclusiveAddressUse = false;
udpClient.Client.Bind(recv_groupep);
while (true)
{
IPEndPoint recv_ipep = null;
try
{
byte[] packet = udpClient.Receive(ref recv_ipep);
MemoryStream ms = new MemoryStream(packet);
BinaryReader br = new BinaryReader(ms);
UInt32 id = br.ReadUInt32();
byte isRequest = br.ReadByte();
if (isRequest == 1)
{
string name = DNS.ReadName(br);
DNScache.clean();
lock (DNScache._lock_cache)
{
if (DNScache._cache.ContainsKey(name))
{
MemoryStream ms_res = new MemoryStream();
BinaryWriter bw = new BinaryWriter(ms_res);
bw.Write(id);
bw.Write((byte)0);
DNScache.cache_entry ce = DNScache._cache[name];
if (ce.success)
{
bw.Write((byte)1);
UInt32 ttl = (UInt32)((ce.expiry - DateTime.Now).TotalSeconds);
bw.Write((UInt32)IPAddress.HostToNetworkOrder((int)ttl));
bw.Write(ce.address, 0, 4);
}
else
{
bw.Write((byte)0);
UInt32 ttl = (UInt32)((ce.expiry - DateTime.Now).TotalSeconds);
bw.Write((UInt32)IPAddress.HostToNetworkOrder((int)ttl));
bw.Write((byte)0);
bw.Write((byte)0);
bw.Write((byte)0);
bw.Write((byte)0);
}
byte[] packet_res = ms_res.ToArray();
udpClient.Send(packet_res, packet_res.Length, recv_ipep);
}
}
}
} catch (ThreadInterruptedException ex) {
return;
}
}
}
