/
UDPClient.cs
978 lines (831 loc) · 37 KB
/
UDPClient.cs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Diagnostics.CodeAnalysis;
using System.Runtime.Versioning;
using System.Threading;
using System.Threading.Tasks;
namespace System.Net.Sockets
{
// The System.Net.Sockets.UdpClient class provides access to UDP services at a higher abstraction
// level than the System.Net.Sockets.Socket class. System.Net.Sockets.UdpClient is used to
// connect to a remote host and to receive connections from a remote client.
public partial class UdpClient : IDisposable
{
private const int MaxUDPSize = 0x10000;
private Socket _clientSocket = null!; // initialized by helper called from ctor
private bool _active;
private readonly byte[] _buffer = new byte[MaxUDPSize];
private AddressFamily _family = AddressFamily.InterNetwork;
// Initializes a new instance of the System.Net.Sockets.UdpClientclass.
public UdpClient() : this(AddressFamily.InterNetwork)
{
}
// Initializes a new instance of the System.Net.Sockets.UdpClientclass.
public UdpClient(AddressFamily family)
{
if (family != AddressFamily.InterNetwork && family != AddressFamily.InterNetworkV6)
{
throw new ArgumentException(SR.Format(SR.net_protocol_invalid_family, "UDP"), nameof(family));
}
_family = family;
CreateClientSocket();
}
// Creates a new instance of the UdpClient class that communicates on the
// specified port number.
//
// NOTE: We should obsolete this. This also breaks IPv6-only scenarios.
// But fixing it has many complications that we have decided not
// to fix it and instead obsolete it later.
public UdpClient(int port) : this(port, AddressFamily.InterNetwork)
{
}
// Creates a new instance of the UdpClient class that communicates on the
// specified port number.
public UdpClient(int port, AddressFamily family)
{
if (!TcpValidationHelpers.ValidatePortNumber(port))
{
throw new ArgumentOutOfRangeException(nameof(port));
}
if (family != AddressFamily.InterNetwork && family != AddressFamily.InterNetworkV6)
{
throw new ArgumentException(SR.Format(SR.net_protocol_invalid_family, "UDP"), nameof(family));
}
IPEndPoint localEP;
_family = family;
if (_family == AddressFamily.InterNetwork)
{
localEP = new IPEndPoint(IPAddress.Any, port);
}
else
{
localEP = new IPEndPoint(IPAddress.IPv6Any, port);
}
CreateClientSocket();
_clientSocket.Bind(localEP);
}
// Creates a new instance of the UdpClient class that communicates on the
// specified end point.
public UdpClient(IPEndPoint localEP)
{
ArgumentNullException.ThrowIfNull(localEP);
// IPv6 Changes: Set the AddressFamily of this object before
// creating the client socket.
_family = localEP.AddressFamily;
CreateClientSocket();
_clientSocket.Bind(localEP);
}
// Used by the class to indicate that a connection to a remote host has been made.
protected bool Active
{
get
{
return _active;
}
set
{
_active = value;
}
}
public int Available
{
get
{
return _clientSocket.Available;
}
}
public Socket Client
{
get
{
return _clientSocket;
}
set
{
_clientSocket = value;
}
}
public short Ttl
{
get
{
return _clientSocket.Ttl;
}
set
{
_clientSocket.Ttl = value;
}
}
public bool DontFragment
{
get
{
return _clientSocket.DontFragment;
}
set
{
_clientSocket.DontFragment = value;
}
}
public bool MulticastLoopback
{
get
{
return _clientSocket.MulticastLoopback;
}
set
{
_clientSocket.MulticastLoopback = value;
}
}
public bool EnableBroadcast
{
get
{
return _clientSocket.EnableBroadcast;
}
set
{
_clientSocket.EnableBroadcast = value;
}
}
public bool ExclusiveAddressUse
{
get
{
return _clientSocket.ExclusiveAddressUse;
}
set
{
_clientSocket.ExclusiveAddressUse = value;
}
}
[SupportedOSPlatform("windows")]
public void AllowNatTraversal(bool allowed)
{
_clientSocket.SetIPProtectionLevel(allowed ? IPProtectionLevel.Unrestricted : IPProtectionLevel.EdgeRestricted);
}
private bool _disposed;
private bool IsAddressFamilyCompatible(AddressFamily family)
{
// Check if the provided address family is compatible with the socket address family
if (family == _family)
{
return true;
}
if (family == AddressFamily.InterNetwork)
{
return _family == AddressFamily.InterNetworkV6 && _clientSocket.DualMode;
}
return false;
}
public void Dispose()
{
Dispose(true);
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
if (NetEventSource.Log.IsEnabled()) NetEventSource.Info(this);
// The only resource we need to free is the network stream, since this
// is based on the client socket, closing the stream will cause us
// to flush the data to the network, close the stream and (in the
// NetoworkStream code) close the socket as well.
if (_disposed)
{
return;
}
Socket chkClientSocket = _clientSocket;
if (chkClientSocket != null)
{
// If the NetworkStream wasn't retrieved, the Socket might
// still be there and needs to be closed to release the effect
// of the Bind() call and free the bound IPEndPoint.
chkClientSocket.InternalShutdown(SocketShutdown.Both);
chkClientSocket.Dispose();
_clientSocket = null!;
}
_disposed = true;
GC.SuppressFinalize(this);
}
}
private bool _isBroadcast;
private void CheckForBroadcast(IPAddress ipAddress)
{
// Here we check to see if the user is trying to use a Broadcast IP address
// we only detect IPAddress.Broadcast (which is not the only Broadcast address)
// and in that case we set SocketOptionName.Broadcast on the socket to allow its use.
// if the user really wants complete control over Broadcast addresses they need to
// inherit from UdpClient and gain control over the Socket and do whatever is appropriate.
if (_clientSocket != null && !_isBroadcast && IsBroadcast(ipAddress))
{
// We need to set the Broadcast socket option.
// Note that once we set the option on the Socket we never reset it.
_isBroadcast = true;
_clientSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);
}
}
private static bool IsBroadcast(IPAddress address)
{
if (address.AddressFamily == AddressFamily.InterNetworkV6)
{
// No such thing as a broadcast address for IPv6.
return false;
}
else
{
return address.Equals(IPAddress.Broadcast);
}
}
public IAsyncResult BeginSend(byte[] datagram, int bytes, AsyncCallback? requestCallback, object? state) =>
BeginSend(datagram, bytes, null, requestCallback, state);
public IAsyncResult BeginSend(byte[] datagram, int bytes, string? hostname, int port, AsyncCallback? requestCallback, object? state) =>
BeginSend(datagram, bytes, GetEndpoint(hostname, port), requestCallback, state);
public IAsyncResult BeginSend(byte[] datagram, int bytes, IPEndPoint? endPoint, AsyncCallback? requestCallback, object? state)
{
ValidateDatagram(datagram, bytes, endPoint);
if (endPoint is null)
{
return _clientSocket.BeginSend(datagram, 0, bytes, SocketFlags.None, requestCallback, state);
}
else
{
CheckForBroadcast(endPoint.Address);
return _clientSocket.BeginSendTo(datagram, 0, bytes, SocketFlags.None, endPoint, requestCallback, state);
}
}
public int EndSend(IAsyncResult asyncResult)
{
ThrowIfDisposed();
return _active ?
_clientSocket.EndSend(asyncResult) :
_clientSocket.EndSendTo(asyncResult);
}
private void ValidateDatagram(byte[] datagram, int bytes, IPEndPoint? endPoint)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(datagram);
ArgumentOutOfRangeException.ThrowIfNegative(bytes);
ArgumentOutOfRangeException.ThrowIfGreaterThan(bytes, datagram.Length);
if (_active && endPoint != null)
{
// Do not allow sending packets to arbitrary host when connected.
throw new InvalidOperationException(SR.net_udpconnected);
}
}
private IPEndPoint? GetEndpoint(string? hostname, int port)
{
if (_active && ((hostname != null) || (port != 0)))
{
// Do not allow sending packets to arbitrary host when connected.
throw new InvalidOperationException(SR.net_udpconnected);
}
IPEndPoint? ipEndPoint = null;
if (hostname != null && port != 0)
{
IPAddress[] addresses = Dns.GetHostAddresses(hostname);
int i = 0;
for (; i < addresses.Length && !IsAddressFamilyCompatible(addresses[i].AddressFamily); i++)
{
}
if (addresses.Length == 0 || i == addresses.Length)
{
throw new ArgumentException(SR.net_invalidAddressList, nameof(hostname));
}
CheckForBroadcast(addresses[i]);
ipEndPoint = new IPEndPoint(addresses[i], port);
}
return ipEndPoint;
}
public IAsyncResult BeginReceive(AsyncCallback? requestCallback, object? state)
{
ThrowIfDisposed();
// Due to the nature of the ReceiveFrom() call and the ref parameter convention,
// we need to cast an IPEndPoint to its base class EndPoint and cast it back down
// to IPEndPoint.
EndPoint tempRemoteEP = _family == AddressFamily.InterNetwork ?
IPEndPointStatics.Any :
IPEndPointStatics.IPv6Any;
return _clientSocket.BeginReceiveFrom(_buffer, 0, MaxUDPSize, SocketFlags.None, ref tempRemoteEP, requestCallback, state);
}
public byte[] EndReceive(IAsyncResult asyncResult, ref IPEndPoint? remoteEP)
{
ThrowIfDisposed();
EndPoint tempRemoteEP = _family == AddressFamily.InterNetwork ?
IPEndPointStatics.Any :
IPEndPointStatics.IPv6Any;
int received = _clientSocket.EndReceiveFrom(asyncResult, ref tempRemoteEP);
remoteEP = (IPEndPoint)tempRemoteEP;
// Because we don't return the actual length, we need to ensure the returned buffer
// has the appropriate length.
if (received < MaxUDPSize)
{
byte[] newBuffer = new byte[received];
Buffer.BlockCopy(_buffer, 0, newBuffer, 0, received);
return newBuffer;
}
return _buffer;
}
// Joins a multicast address group.
public void JoinMulticastGroup(IPAddress multicastAddr)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(multicastAddr);
if (multicastAddr.AddressFamily != _family)
{
// For IPv6, we need to create the correct MulticastOption and must also check for address family compatibility.
// Note: we cannot reliably use IPv4 multicast over IPv6 in DualMode, as such we keep the compatibility explicit between IP stack versions
throw new ArgumentException(SR.Format(SR.net_protocol_invalid_multicast_family, "UDP"), nameof(multicastAddr));
}
if (_family == AddressFamily.InterNetwork)
{
_clientSocket.SetSocketOption(
SocketOptionLevel.IP,
SocketOptionName.AddMembership,
new MulticastOption(multicastAddr));
}
else
{
_clientSocket.SetSocketOption(
SocketOptionLevel.IPv6,
SocketOptionName.AddMembership,
new IPv6MulticastOption(multicastAddr));
}
}
public void JoinMulticastGroup(IPAddress multicastAddr, IPAddress localAddress)
{
ThrowIfDisposed();
if (_family != AddressFamily.InterNetwork)
{
throw new SocketException((int)SocketError.OperationNotSupported);
}
_clientSocket.SetSocketOption(
SocketOptionLevel.IP,
SocketOptionName.AddMembership,
new MulticastOption(multicastAddr, localAddress));
}
// Joins an IPv6 multicast address group.
public void JoinMulticastGroup(int ifindex, IPAddress multicastAddr)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(multicastAddr);
ArgumentOutOfRangeException.ThrowIfNegative(ifindex);
if (_family != AddressFamily.InterNetworkV6)
{
// Ensure that this is an IPv6 client, otherwise throw WinSock
// Operation not supported socked exception.
throw new SocketException((int)SocketError.OperationNotSupported);
}
_clientSocket.SetSocketOption(
SocketOptionLevel.IPv6,
SocketOptionName.AddMembership,
new IPv6MulticastOption(multicastAddr, ifindex));
}
// Joins a multicast address group with the specified time to live (TTL).
public void JoinMulticastGroup(IPAddress multicastAddr, int timeToLive)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(multicastAddr);
if (!RangeValidationHelpers.ValidateRange(timeToLive, 0, 255))
{
throw new ArgumentOutOfRangeException(nameof(timeToLive));
}
// Join the Multicast Group.
JoinMulticastGroup(multicastAddr);
// Set Time To Live (TTL).
_clientSocket.SetSocketOption(
(_family == AddressFamily.InterNetwork) ? SocketOptionLevel.IP : SocketOptionLevel.IPv6,
SocketOptionName.MulticastTimeToLive,
timeToLive);
}
// Leaves a multicast address group.
public void DropMulticastGroup(IPAddress multicastAddr)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(multicastAddr);
if (multicastAddr.AddressFamily != _family)
{
// For IPv6, we need to create the correct MulticastOption and must also check for address family compatibility.
throw new ArgumentException(SR.Format(SR.net_protocol_invalid_multicast_family, "UDP"), nameof(multicastAddr));
}
if (_family == AddressFamily.InterNetwork)
{
_clientSocket.SetSocketOption(
SocketOptionLevel.IP,
SocketOptionName.DropMembership,
new MulticastOption(multicastAddr));
}
else
{
_clientSocket.SetSocketOption(
SocketOptionLevel.IPv6,
SocketOptionName.DropMembership,
new IPv6MulticastOption(multicastAddr));
}
}
// Leaves an IPv6 multicast address group.
public void DropMulticastGroup(IPAddress multicastAddr, int ifindex)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(multicastAddr);
ArgumentOutOfRangeException.ThrowIfNegative(ifindex);
if (_family != AddressFamily.InterNetworkV6)
{
// Ensure that this is an IPv6 client.
throw new SocketException((int)SocketError.OperationNotSupported);
}
_clientSocket.SetSocketOption(
SocketOptionLevel.IPv6,
SocketOptionName.DropMembership,
new IPv6MulticastOption(multicastAddr, ifindex));
}
public Task<int> SendAsync(byte[] datagram, int bytes) =>
SendAsync(datagram, bytes, null);
/// <summary>
/// Sends a UDP datagram asynchronously to a remote host.
/// </summary>
/// <param name="datagram">
/// An <see cref="ReadOnlyMemory{T}"/> of Type <see cref="byte"/> that specifies the UDP datagram that you intend to send.
/// </param>
/// <param name="cancellationToken">
/// The token to monitor for cancellation requests. The default value is None.
/// </param>
/// <returns>A <see cref="ValueTask{T}"/> that represents the asynchronous send operation. The value of its Result property contains the number of bytes sent.</returns>
/// <exception cref="ObjectDisposedException">The <see cref="UdpClient"/> is closed.</exception>
/// <exception cref="SocketException">An error occurred when accessing the socket.</exception>
public ValueTask<int> SendAsync(ReadOnlyMemory<byte> datagram, CancellationToken cancellationToken = default) =>
SendAsync(datagram, null, cancellationToken);
public Task<int> SendAsync(byte[] datagram, int bytes, string? hostname, int port) =>
SendAsync(datagram, bytes, GetEndpoint(hostname, port));
/// <summary>
/// Sends a UDP datagram asynchronously to a remote host.
/// </summary>
/// <param name="datagram">
/// An <see cref="ReadOnlyMemory{T}"/> of Type <see cref="byte"/> that specifies the UDP datagram that you intend to send.
/// </param>
/// <param name="hostname">
/// The name of the remote host to which you intend to send the datagram.
/// </param>
/// <param name="port">
/// The remote port number with which you intend to communicate.
/// </param>
/// <param name="cancellationToken">
/// The token to monitor for cancellation requests. The default value is None.
/// </param>
/// <returns>A <see cref="ValueTask{T}"/> that represents the asynchronous send operation. The value of its Result property contains the number of bytes sent.</returns>
/// <exception cref="InvalidOperationException">The <see cref="UdpClient"/> has already established a default remote host.</exception>
/// <exception cref="ObjectDisposedException">The <see cref="UdpClient"/> is closed.</exception>
/// <exception cref="SocketException">An error occurred when accessing the socket.</exception>
public ValueTask<int> SendAsync(ReadOnlyMemory<byte> datagram, string? hostname, int port, CancellationToken cancellationToken = default) =>
SendAsync(datagram, GetEndpoint(hostname, port), cancellationToken);
public Task<int> SendAsync(byte[] datagram, int bytes, IPEndPoint? endPoint)
{
ValidateDatagram(datagram, bytes, endPoint);
if (endPoint is null)
{
return _clientSocket.SendAsync(new ArraySegment<byte>(datagram, 0, bytes), SocketFlags.None);
}
else
{
CheckForBroadcast(endPoint.Address);
return _clientSocket.SendToAsync(new ArraySegment<byte>(datagram, 0, bytes), SocketFlags.None, endPoint);
}
}
/// <summary>
/// Sends a UDP datagram asynchronously to a remote host.
/// </summary>
/// <param name="datagram">
/// An <see cref="ReadOnlyMemory{T}"/> of Type <see cref="byte"/> that specifies the UDP datagram that you intend to send.
/// </param>
/// <param name="endPoint">
/// An <see cref="IPEndPoint"/> that represents the host and port to which to send the datagram.
/// </param>
/// <param name="cancellationToken">
/// The token to monitor for cancellation requests. The default value is None.
/// </param>
/// <returns>A <see cref="ValueTask{T}"/> that represents the asynchronous send operation. The value of its Result property contains the number of bytes sent.</returns>
/// <exception cref="InvalidOperationException"><see cref="UdpClient"/> has already established a default remote host and <paramref name="endPoint"/> is not <see langword="null"/>.</exception>
/// <exception cref="ObjectDisposedException">The <see cref="UdpClient"/> is closed.</exception>
/// <exception cref="SocketException">An error occurred when accessing the socket.</exception>
public ValueTask<int> SendAsync(ReadOnlyMemory<byte> datagram, IPEndPoint? endPoint, CancellationToken cancellationToken = default)
{
ThrowIfDisposed();
if (endPoint is null)
{
return _clientSocket.SendAsync(datagram, SocketFlags.None, cancellationToken);
}
if (_active)
{
// Do not allow sending packets to arbitrary host when connected.
throw new InvalidOperationException(SR.net_udpconnected);
}
CheckForBroadcast(endPoint.Address);
return _clientSocket.SendToAsync(datagram, SocketFlags.None, endPoint, cancellationToken);
}
public Task<UdpReceiveResult> ReceiveAsync()
{
ThrowIfDisposed();
return WaitAndWrap(_clientSocket.ReceiveFromAsync(
new ArraySegment<byte>(_buffer, 0, MaxUDPSize),
SocketFlags.None,
_family == AddressFamily.InterNetwork ? IPEndPointStatics.Any : IPEndPointStatics.IPv6Any));
async Task<UdpReceiveResult> WaitAndWrap(Task<SocketReceiveFromResult> task)
{
SocketReceiveFromResult result = await task.ConfigureAwait(false);
byte[] buffer = result.ReceivedBytes < MaxUDPSize ?
_buffer.AsSpan(0, result.ReceivedBytes).ToArray() :
_buffer;
return new UdpReceiveResult(buffer, (IPEndPoint)result.RemoteEndPoint);
}
}
/// <summary>
/// Returns a UDP datagram asynchronously that was sent by a remote host.
/// </summary>
/// <param name="cancellationToken">
/// The token to monitor for cancellation requests.
/// </param>
/// <returns>A <see cref="ValueTask{TResult}"/> representing the asynchronous operation.</returns>
/// <exception cref="ObjectDisposedException">The underlying <see cref="Socket"/> has been closed.</exception>
/// <exception cref="SocketException">An error occurred when accessing the socket.</exception>
public ValueTask<UdpReceiveResult> ReceiveAsync(CancellationToken cancellationToken)
{
ThrowIfDisposed();
return WaitAndWrap(_clientSocket.ReceiveFromAsync(
_buffer,
SocketFlags.None,
_family == AddressFamily.InterNetwork ? IPEndPointStatics.Any : IPEndPointStatics.IPv6Any, cancellationToken));
async ValueTask<UdpReceiveResult> WaitAndWrap(ValueTask<SocketReceiveFromResult> task)
{
SocketReceiveFromResult result = await task.ConfigureAwait(false);
byte[] buffer = result.ReceivedBytes < MaxUDPSize ?
_buffer.AsSpan(0, result.ReceivedBytes).ToArray() :
_buffer;
return new UdpReceiveResult(buffer, (IPEndPoint)result.RemoteEndPoint);
}
}
private void CreateClientSocket()
{
// Common initialization code.
//
// IPv6 Changes: Use the AddressFamily of this class rather than hardcode.
_clientSocket = new Socket(_family, SocketType.Dgram, ProtocolType.Udp);
}
public UdpClient(string hostname, int port)
{
ArgumentNullException.ThrowIfNull(hostname);
if (!TcpValidationHelpers.ValidatePortNumber(port))
{
throw new ArgumentOutOfRangeException(nameof(port));
}
// NOTE: Need to create different kinds of sockets based on the addresses
// returned from DNS. As a result, we defer the creation of the
// socket until the Connect method.
Connect(hostname, port);
}
public void Close()
{
Dispose(true);
}
public void Connect(string hostname, int port)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(hostname);
if (!TcpValidationHelpers.ValidatePortNumber(port))
{
throw new ArgumentOutOfRangeException(nameof(port));
}
// We must now look for addresses that use a compatible address family to the client socket. However, in the
// case of the <hostname,port> constructor we will have deferred creating the socket and will do that here
// instead.
IPAddress[] addresses = Dns.GetHostAddresses(hostname);
Exception? lastex = null;
Socket? ipv6Socket = null;
Socket? ipv4Socket = null;
try
{
if (_clientSocket == null)
{
if (Socket.OSSupportsIPv4)
{
ipv4Socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
}
if (Socket.OSSupportsIPv6)
{
ipv6Socket = new Socket(AddressFamily.InterNetworkV6, SocketType.Dgram, ProtocolType.Udp);
}
}
foreach (IPAddress address in addresses)
{
try
{
if (_clientSocket == null)
{
// We came via the <hostname,port> constructor. Set the
// address family appropriately, create the socket and
// try to connect.
if (address.AddressFamily == AddressFamily.InterNetwork && ipv4Socket != null)
{
ipv4Socket.Connect(address, port);
_clientSocket = ipv4Socket;
ipv6Socket?.Close();
}
else if (ipv6Socket != null)
{
ipv6Socket.Connect(address, port);
_clientSocket = ipv6Socket;
ipv4Socket?.Close();
}
_family = address.AddressFamily;
_active = true;
break;
}
else if (IsAddressFamilyCompatible(address.AddressFamily))
{
// Only use addresses with a matching family
Connect(new IPEndPoint(address, port));
_active = true;
break;
}
}
catch (Exception ex)
{
if (ExceptionCheck.IsFatal(ex))
{
throw;
}
lastex = ex;
}
}
}
catch (Exception ex)
{
if (ExceptionCheck.IsFatal(ex))
{
throw;
}
lastex = ex;
}
finally
{
//cleanup temp sockets if failed
//main socket gets closed when tcpclient gets closed
//did we connect?
if (!_active)
{
ipv6Socket?.Close();
ipv4Socket?.Close();
// The connect failed - rethrow the last error we had
if (lastex != null)
{
throw lastex;
}
else
{
throw new SocketException((int)SocketError.NotConnected);
}
}
}
}
public void Connect(IPAddress addr, int port)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(addr);
if (!TcpValidationHelpers.ValidatePortNumber(port))
{
throw new ArgumentOutOfRangeException(nameof(port));
}
IPEndPoint endPoint = new IPEndPoint(addr, port);
Connect(endPoint);
}
public void Connect(IPEndPoint endPoint)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(endPoint);
CheckForBroadcast(endPoint.Address);
Client.Connect(endPoint);
_active = true;
}
public byte[] Receive([NotNull] ref IPEndPoint? remoteEP)
{
ThrowIfDisposed();
// this is a fix due to the nature of the ReceiveFrom() call and the
// ref parameter convention, we need to cast an IPEndPoint to it's base
// class EndPoint and cast it back down to IPEndPoint. ugly but it works.
EndPoint tempRemoteEP = _family == AddressFamily.InterNetwork ?
IPEndPointStatics.Any :
IPEndPointStatics.IPv6Any;
int received = Client.ReceiveFrom(_buffer, MaxUDPSize, 0, ref tempRemoteEP);
remoteEP = (IPEndPoint)tempRemoteEP;
// because we don't return the actual length, we need to ensure the returned buffer
// has the appropriate length.
if (received < MaxUDPSize)
{
byte[] newBuffer = new byte[received];
Buffer.BlockCopy(_buffer, 0, newBuffer, 0, received);
return newBuffer;
}
return _buffer;
}
// Sends a UDP datagram to the host at the remote end point.
public int Send(byte[] dgram, int bytes, IPEndPoint? endPoint)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(dgram);
if (_active && endPoint != null)
{
// Do not allow sending packets to arbitrary host when connected
throw new InvalidOperationException(SR.net_udpconnected);
}
if (endPoint == null)
{
return Client.Send(dgram, 0, bytes, SocketFlags.None);
}
CheckForBroadcast(endPoint.Address);
return Client.SendTo(dgram, 0, bytes, SocketFlags.None, endPoint);
}
/// <summary>
/// Sends a UDP datagram to the host at the specified remote endpoint.
/// </summary>
/// <param name="datagram">
/// An <see cref="ReadOnlySpan{T}"/> of Type <see cref="byte"/> that specifies the UDP datagram that you intend to send.
/// </param>
/// <param name="endPoint">
/// An <see cref="IPEndPoint"/> that represents the host and port to which to send the datagram.
/// </param>
/// <returns>The number of bytes sent.</returns>
/// <exception cref="InvalidOperationException"><see cref="UdpClient"/> has already established a default remote host and <paramref name="endPoint"/> is not <see langword="null"/>.</exception>
/// <exception cref="ObjectDisposedException"><see cref="UdpClient"/> is closed.</exception>
/// <exception cref="SocketException">An error occurred when accessing the socket.</exception>
public int Send(ReadOnlySpan<byte> datagram, IPEndPoint? endPoint)
{
ThrowIfDisposed();
if (_active && endPoint != null)
{
// Do not allow sending packets to arbitrary host when connected
throw new InvalidOperationException(SR.net_udpconnected);
}
if (endPoint == null)
{
return Client.Send(datagram, SocketFlags.None);
}
CheckForBroadcast(endPoint.Address);
return Client.SendTo(datagram, SocketFlags.None, endPoint);
}
// Sends a UDP datagram to the specified port on the specified remote host.
public int Send(byte[] dgram, int bytes, string? hostname, int port) => Send(dgram, bytes, GetEndpoint(hostname, port));
/// <summary>
/// Sends a UDP datagram to a specified port on a specified remote host.
/// </summary>
/// <param name="datagram">
/// An <see cref="ReadOnlySpan{T}"/> of Type <see cref="byte"/> that specifies the UDP datagram that you intend to send.
/// </param>
/// <param name="hostname">
/// The name of the remote host to which you intend to send the datagram.
/// </param>
/// <param name="port">
/// The remote port number with which you intend to communicate.
/// </param>
/// <returns>The number of bytes sent.</returns>
/// <exception cref="InvalidOperationException">The <see cref="UdpClient"/> has already established a default remote host.</exception>
/// <exception cref="ObjectDisposedException">The <see cref="UdpClient"/> is closed.</exception>
/// <exception cref="SocketException">An error occurred when accessing the socket.</exception>
public int Send(ReadOnlySpan<byte> datagram, string? hostname, int port) => Send(datagram, GetEndpoint(hostname, port));
// Sends a UDP datagram to a remote host.
public int Send(byte[] dgram, int bytes)
{
ThrowIfDisposed();
ArgumentNullException.ThrowIfNull(dgram);
if (!_active)
{
// only allowed on connected socket
throw new InvalidOperationException(SR.net_notconnected);
}
return Client.Send(dgram, 0, bytes, SocketFlags.None);
}
/// <summary>
/// Sends a UDP datagram to a remote host.
/// </summary>
/// <param name="datagram">
/// An <see cref="ReadOnlySpan{T}"/> of Type <see cref="byte"/> that specifies the UDP datagram that you intend to send.
/// </param>
/// <returns>The number of bytes sent.</returns>
/// <exception cref="InvalidOperationException">The <see cref="UdpClient"/> has not established a default remote host.</exception>
/// <exception cref="ObjectDisposedException">The <see cref="UdpClient"/> is closed.</exception>
/// <exception cref="SocketException">An error occurred when accessing the socket.</exception>
public int Send(ReadOnlySpan<byte> datagram)
{
ThrowIfDisposed();
if (!_active)
{
// only allowed on connected socket
throw new InvalidOperationException(SR.net_notconnected);
}
return Client.Send(datagram, SocketFlags.None);
}
private void ThrowIfDisposed()
{
ObjectDisposedException.ThrowIf(_disposed, this);
}
}
}