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;
}
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(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 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;
}
