Better IPv6 support/fallback. Support RpcError in response to an API returning an array

.github/ci.yml

@@ -2,7 +2,7 @@ pr: none
 trigger:
 - master
 
-name: 1.0.0-ci.$(Rev:r)
+name: 1.0.1-ci.$(Rev:r)
 
 pool:
   vmImage: ubuntu-latest

.github/release.yml

@@ -1,7 +1,7 @@
 pr: none
 trigger: none
 
-name: 1.0.0
+name: 1.0.$(Rev:r)
 
 pool:
   vmImage: ubuntu-latest

src/Client.cs

@@ -26,6 +26,7 @@ namespace WTelegram
 		public Config TLConfig { get; private set; }
 		public int MaxAutoReconnects { get; set; } = 5; // number of automatic reconnections on connection/reactor failure
 		public bool IsMainDC => (_dcSession?.DataCenter?.id ?? 0) == _session.MainDC;
+		public bool Connected => _tcpClient?.Connected ?? false;
 
 		private readonly Func<string, string> _config;
 		private readonly int _apiId;
@@ -121,12 +122,19 @@ namespace WTelegram
 		// disconnect and eventually forget user and disconnect other sessions
 		public void Reset(bool resetUser = true, bool resetSessions = true)
 		{
-			if (CheckMsgsToAck() is MsgsAck msgsAck)
-				SendAsync(MakeFunction(msgsAck), false).Wait(1000);
+			try
+			{
+				if (CheckMsgsToAck() is MsgsAck msgsAck)
+					SendAsync(MakeFunction(msgsAck), false).Wait(1000);
+			}
+			catch (Exception)
+			{
+			}
 			_cts?.Cancel();
 			_sendSemaphore = new(0);
 			_reactorTask = null;
 			_tcpClient?.Dispose();
+			_tcpClient = null;
 			_connecting = null;
 			if (resetSessions)
 			{
@@ -154,8 +162,49 @@ namespace WTelegram
 		{
 			var endpoint = _dcSession?.EndPoint ?? Compat.IPEndPoint_Parse(Config("server_address"));
 			Helpers.Log(2, $"Connecting to {endpoint}...");
-			_tcpClient = new TcpClient(endpoint.AddressFamily);
-			await _tcpClient.ConnectAsync(endpoint.Address, endpoint.Port);
+			_tcpClient = new TcpClient(AddressFamily.InterNetworkV6) { Client = { DualMode = true } }; // this allows both IPv4 & IPv6
+			try
+			{
+				await _tcpClient.ConnectAsync(endpoint.Address, endpoint.Port);
+			}
+			catch (SocketException ex) // cannot connect to target endpoint, try to find an alternate
+			{
+				Helpers.Log(4, $"SocketException {ex.SocketErrorCode} ({ex.ErrorCode}): {ex.Message}");
+				if (_dcSession?.DataCenter == null) throw;
+				var triedEndpoints = new HashSet<IPEndPoint> { endpoint };
+				if (_session.DcOptions != null)
+				{
+					var altOptions = _session.DcOptions.Where(dco => dco.id == _dcSession.DataCenter.id && dco.flags != _dcSession.DataCenter.flags
+						&& (dco.flags & (DcOption.Flags.cdn | DcOption.Flags.tcpo_only | DcOption.Flags.media_only)) == 0)
+						.OrderBy(dco => dco.flags);
+					// try alternate addresses for this DC
+					foreach (var dcOption in altOptions)
+					{
+						endpoint = new(IPAddress.Parse(dcOption.ip_address), dcOption.port);
+						if (!triedEndpoints.Add(endpoint)) continue;
+						Helpers.Log(2, $"Connecting to {endpoint}...");
+						try
+						{
+							await _tcpClient.ConnectAsync(endpoint.Address, endpoint.Port);
+							_dcSession.DataCenter = dcOption;
+							break;
+						}
+						catch (SocketException) { }
+					}
+				}
+				if (!_tcpClient.Connected)
+				{
+					endpoint = Compat.IPEndPoint_Parse(Config("server_address")); // re-ask callback for an address
+					if (!triedEndpoints.Add(endpoint)) throw;
+					_dcSession.Client = null;
+					// is it address for a known DCSession?
+					_dcSession = _session.DCSessions.Values.FirstOrDefault(dcs => dcs.EndPoint.Equals(endpoint));
+					_dcSession ??= new() { Id = Helpers.RandomLong() };
+					_dcSession.Client = this;
+					Helpers.Log(2, $"Connecting to {endpoint}...");
+					await _tcpClient.ConnectAsync(endpoint.Address, endpoint.Port);
+				}
+			}
 			_networkStream = _tcpClient.GetStream();
 			await _networkStream.WriteAsync(IntermediateHeader, 0, 4);
 			_cts = new();
@@ -178,10 +227,11 @@ namespace WTelegram
 						Config("lang_pack"),
 						Config("lang_code"),
 						Schema.Help_GetConfig));
+				_session.DcOptions = TLConfig.dc_options;
 				_saltChangeCounter = 0;
 				if (_dcSession.DataCenter == null)
 				{
-					_dcSession.DataCenter = TLConfig.dc_options.Where(dc => dc.id == TLConfig.this_dc)
+					_dcSession.DataCenter = _session.DcOptions.Where(dc => dc.id == TLConfig.this_dc)
 						.OrderByDescending(dc => dc.ip_address == endpoint.Address.ToString())
 						.ThenByDescending(dc => dc.port == endpoint.Port).First();
 					_session.DCSessions[TLConfig.this_dc] = _dcSession;
@@ -195,13 +245,14 @@ namespace WTelegram
 			Helpers.Log(2, $"Connected to {(TLConfig.test_mode ? "Test DC" : "DC")} {TLConfig.this_dc}... {TLConfig.flags & (Config.Flags)~0xE00}");
 		}
 
-		public async Task<Client> GetClientForDC(int dcId, bool connect = true)
+		public async Task<Client> GetClientForDC(int dcId, bool media_only = true, bool connect = true)
 		{
 			if (_dcSession.DataCenter?.id == dcId) return this;
 			Session.DCSession altSession;
 			lock (_session)
 			{
-				altSession = GetOrCreateDCSession(dcId);
+				altSession = GetOrCreateDCSession(dcId, _dcSession.DataCenter.flags | (media_only ? DcOption.Flags.media_only : 0));
+				if (!altSession.Client.Connected) { altSession.Client.Dispose(); altSession.Client = null; }
 				altSession.Client ??= new Client(this, altSession);
 			}
 			Helpers.Log(2, $"Requested connection to DC {dcId}...");
@@ -231,18 +282,17 @@ namespace WTelegram
 			return altSession.Client;
 		}
 
-		private Session.DCSession GetOrCreateDCSession(int dcId)
+		private Session.DCSession GetOrCreateDCSession(int dcId, DcOption.Flags flags)
 		{
 			if (_session.DCSessions.TryGetValue(dcId, out var dcSession))
-				return dcSession;
-			var prevFamily = _tcpClient.Client.RemoteEndPoint.AddressFamily;
-			var dcOptions = TLConfig.dc_options.Where(dc => dc.id == dcId && (dc.flags & (DcOption.Flags.media_only | DcOption.Flags.cdn)) == 0);
-			if (prevFamily == AddressFamily.InterNetworkV6) // try to stay in the same connectivity
-				dcOptions = dcOptions.OrderByDescending(dc => dc.flags & DcOption.Flags.ipv6);  // list ipv6 first
-			else
-				dcOptions = dcOptions.OrderBy(dc => dc.flags & DcOption.Flags.ipv6);            // list ipv4 first
+				if (dcSession.Client != null || dcSession.DataCenter.flags == flags)
+					return dcSession; // if we have already a session with this DC and we are connected or it is a perfect match, use it
+			// try to find the most appropriate DcOption for this DC
+			var dcOptions = _session.DcOptions.Where(dc => dc.id == dcId).OrderBy(dc => dc.flags ^ flags);
 			var dcOption = dcOptions.FirstOrDefault() ?? throw new ApplicationException($"Could not find adequate dc_option for DC {dcId}");
-			return dcSession = _session.DCSessions[dcId] = new Session.DCSession { DataCenter = dcOption, Id = Helpers.RandomLong() };
+			dcSession ??= new Session.DCSession { Id = Helpers.RandomLong() }; // create new session only if not already existing
+			dcSession.DataCenter = dcOption;
+			return _session.DCSessions[dcId] = dcSession;
 		}
 
 		internal DateTime MsgIdToStamp(long serverMsgId)
@@ -587,7 +637,15 @@ namespace WTelegram
 			object result;
 			if (tcs != null)
 			{
-				result = reader.ReadTLValue(type);
+				if (!type.IsArray)
+					result = reader.ReadTLValue(type);
+				else if (reader.ReadUInt32() == Layer.RpcErrorCtor)
+					result = reader.ReadTLObject(Layer.RpcErrorCtor);
+				else
+				{
+					reader.BaseStream.Position -= 4;
+					result = reader.ReadTLValue(type);
+				}
 				if (type.IsEnum) result = Enum.ToObject(type, result);
 				Log(1, "");
 				tcs.SetResult(result);
@@ -652,7 +710,7 @@ namespace WTelegram
 							// this is a hack to migrate _dcSession in-place (staying in same Client):
 							Session.DCSession dcSession;
 							lock (_session)
-								dcSession = GetOrCreateDCSession(number);
+								dcSession = GetOrCreateDCSession(number, _dcSession.DataCenter.flags);
 							Reset(false, false);
 							_session.MainDC = number;
 							_dcSession.Client = null;
@@ -1060,7 +1118,7 @@ namespace WTelegram
 			const int ChunkSize = 128 * 1024;
 			int fileSize = 0;
 			Upload_File fileData;
-			var client = fileDC == 0 ? this : await GetClientForDC(fileDC);
+			var client = fileDC == 0 ? this : await GetClientForDC(fileDC, true);
 			do
 			{
 				Upload_FileBase fileBase;
@@ -1072,7 +1130,7 @@ namespace WTelegram
 				catch (RpcException ex) when (ex.Code == 303 && ex.Message.StartsWith("FILE_MIGRATE_"))
 				{
 					var dcId = int.Parse(ex.Message[13..]);
-					client = await GetClientForDC(dcId);
+					client = await GetClientForDC(dcId, true);
 					fileBase = await client.Upload_GetFile(fileLocation, fileSize, ChunkSize);
 				}
 				fileData = fileBase as Upload_File;

src/Compat.cs

@@ -50,7 +50,7 @@ namespace WTelegram
 
 		internal static IPEndPoint IPEndPoint_Parse(string addr)
 		{
-			int colon = addr.IndexOf(':');
+			int colon = addr.LastIndexOf(':');
 			return new IPEndPoint(IPAddress.Parse(addr[0..colon]), int.Parse(addr[(colon + 1)..]));
 		}
 

src/Helpers.TL.cs

@@ -24,6 +24,7 @@ namespace TL
 		public override string Title => null;
 		public override bool IsBanned(ChatBannedRights.Flags flags = 0) => true;
 		protected override InputPeer ToInputPeer() => null;
+		public override string ToString() => $"ChatEmpty {id}";
 	}
 	partial class Chat
 	{
@@ -31,6 +32,7 @@ namespace TL
 		public override string Title => title;
 		public override bool IsBanned(ChatBannedRights.Flags flags = 0) => ((default_banned_rights?.flags ?? 0) & flags) != 0;
 		protected override InputPeer ToInputPeer() => new InputPeerChat { chat_id = id };
+		public override string ToString() => $"Chat \"{title}\"";
 	}
 	partial class ChatForbidden
 	{
@@ -38,6 +40,7 @@ namespace TL
 		public override string Title => title;
 		public override bool IsBanned(ChatBannedRights.Flags flags = 0) => true;
 		protected override InputPeer ToInputPeer() => new InputPeerChat { chat_id = id };
+		public override string ToString() => $"ChatForbidden {id} \"{title}\"";
 	}
 	partial class Channel
 	{
@@ -46,6 +49,8 @@ namespace TL
 		public override bool IsBanned(ChatBannedRights.Flags flags = 0) => ((banned_rights?.flags ?? 0) & flags) != 0 || ((default_banned_rights?.flags ?? 0) & flags) != 0;
 		protected override InputPeer ToInputPeer() => new InputPeerChannel { channel_id = id, access_hash = access_hash };
 		public static implicit operator InputChannel(Channel channel) => new() { channel_id = channel.id, access_hash = channel.access_hash };
+		public override string ToString() =>
+			(flags.HasFlag(Flags.broadcast) ? "Channel " : "Group ") + (username != null ? '@' + username : $"\"{title}\"");
 	}
 	partial class ChannelForbidden
 	{
@@ -53,6 +58,7 @@ namespace TL
 		public override string Title => title;
 		public override bool IsBanned(ChatBannedRights.Flags flags = 0) => true;
 		protected override InputPeer ToInputPeer() => new InputPeerChannel { channel_id = id, access_hash = access_hash };
+		public override string ToString() => $"ChannelForbidden {id} \"{title}\"";
 	}
 
 	partial class UserBase

src/Session.cs

@@ -14,6 +14,7 @@ namespace WTelegram
 		public TL.User User;
 		public int MainDC;
 		public Dictionary<int, DCSession> DCSessions = new();
+		public TL.DcOption[] DcOptions;
 
 		public class DCSession
 		{

src/TL.Table.cs

@@ -10,6 +10,7 @@ namespace TL
 		internal const uint VectorCtor = 0x1CB5C415;
 		internal const uint NullCtor = 0x56730BCC;
 		internal const uint RpcResultCtor = 0xF35C6D01;
+		internal const uint RpcErrorCtor = 0x2144CA19;
 		internal const uint MsgContainerCtor = 0x73F1F8DC;
 
 		internal readonly static Dictionary<uint, Type> Table = new()