protected async Task <List <ServerAddress> > RetrieveAsync(int limit, IPEndPoint remote = null, int tried = -1)
{
var cur = -1;
var servers = new List <ServerAddress>();
if (remote == null)
{
var hosts = Dns.GetHostAddresses("hl2master.steampowered.com");
if (tried == -1)
{
cur = new Random().Next(hosts.Length);
}
else
{
cur = (tried + 1) % hosts.Length;
}
var host = hosts[cur];
const int port = 27011;
#if DEBUG
this.Logger().Debug("Contacting master server {0}:{1}", host, port);
#endif
remote = new IPEndPoint(host, port); //TODO: alternate ip and ports availability
}
var e = new IPEndPoint(IPAddress.Any, 0);
var udpClient = new UdpClient(e)
{
Client = { ReceiveTimeout = DefaultReceiveTimeout, SendTimeout = DefaultSendTimeout }
};
udpClient.Connect(remote);
var i = 0;
const int maxIterations = 30;
string lastSeed;
var seed = "0.0.0.0:0";
do
{
lastSeed = seed;
var msg = BuildMessage(seed);
if (await udpClient.SendAsync(msg, msg.Length).ConfigureAwait(false) != msg.Length)
{
throw new Exception("Send failed.");
}
byte[] response = null;
var timedOut = false;
try {
response =
(await udpClient.ReceiveWithTimeoutAfter(DefaultReceiveTimeout).ConfigureAwait(false)).Buffer;
} catch (TimeoutException) {
timedOut = true;
if (cur == -1 || tried != -1 || i != 0)
{
throw new TimeoutException($"Received timeout on try: {(tried == -1 ? 1 : 2)} packet: {i}");
}
}
//only retries when remote was not passed in, on the first try, and when the first packet was never received
if (timedOut)
{
return(await RetrieveAsync(limit, null, cur));
}
seed = ParseResponse(servers, response, limit);
if (seed == null)
{
throw new Exception("Bad packet recieved.");
}
i++;
} while (i < maxIterations && !seed.Equals("0.0.0.0:0") && !seed.Equals(lastSeed));
#if DEBUG
this.Logger().Debug("Found {0} servers in {1} packets.", servers.Count, i);
#endif
return(servers);
}
public async Task <List <IPEndPoint> > GetParsedServers(CancellationToken cancelToken, int limit = -1,
IPEndPoint remote = null, int tried = -1)
{
var cur = -1;
var servers = new List <IPEndPoint>();
if (remote == null)
{
var hosts = await Dns.GetHostAddressesAsync("hl2master.steampowered.com").ConfigureAwait(false);
if (tried == -1)
{
cur = new Random().Next(hosts.Length);
}
else
{
cur = (tried + 1) % hosts.Length;
}
var host = hosts[cur];
const int port = 27011;
remote = new IPEndPoint(host, port); //TODO: alternate ip and ports availability
}
var e = new IPEndPoint(IPAddress.Any, 0);
var udpClient = new UdpClient(e)
{
Client = { ReceiveTimeout = Consts.DefaultReceiveTimeout, SendTimeout = Consts.DefaultSendTimeout }
};
var i = 0;
const int maxIterations = 30;
string lastSeed;
var seed = "0.0.0.0:0";
do
{
cancelToken.ThrowIfCancellationRequested();
lastSeed = seed;
var msg = BuildMessage(seed);
if (await udpClient.SendAsync(msg, msg.Length, remote).ConfigureAwait(false) != msg.Length)
{
throw new Exception("Send failed.");
}
byte[] response = null;
var timedOut = false;
try {
response =
(await
udpClient.ReceiveWithTimeoutAfter(Consts.DefaultReceiveTimeout, cancelToken).ConfigureAwait(false))
.Buffer;
} catch (TimeoutException) {
timedOut = true;
if ((cur == -1) || (tried != -1) || (i != 0))
{
throw new TimeoutException(string.Format("Received timeout on try: {0} packet: {1}",
tried == -1 ? 1 : 2, i));
}
}
//only retries when remote was not passed in, on the first try, and when the first packet was never received
if (timedOut)
{
return(await GetParsedServers(cancelToken, limit, null, cur).ConfigureAwait(false));
}
seed = ParseResponse(servers, response, limit);
if (seed == null)
{
throw new Exception("Bad packet recieved.");
}
i++;
} while ((i < maxIterations) && !seed.Equals("0.0.0.0:0") && !seed.Equals(lastSeed));
return(servers);
}
