adding span version of ReceiveMessageFrom

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }

src/libraries/System.Net.Sockets/ref/System.Net.Sockets.cs

@@ -388,6 +388,7 @@ public void Listen(int backlog) { }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveFromResult> ReceiveFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) { throw null; }
  public bool ReceiveFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }
  public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
+ public int ReceiveMessageFrom(System.Span<byte> buffer, ref System.Net.Sockets.SocketFlags socketFlags, ref System.Net.EndPoint remoteEP, out System.Net.Sockets.IPPacketInformation ipPacketInformation) { throw null; }
  public System.Threading.Tasks.Task<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.ArraySegment<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint) { throw null; }
  public System.Threading.Tasks.ValueTask<System.Net.Sockets.SocketReceiveMessageFromResult> ReceiveMessageFromAsync(System.Memory<byte> buffer, System.Net.Sockets.SocketFlags socketFlags, System.Net.EndPoint remoteEndPoint, System.Threading.CancellationToken cancellationToken = default) { throw null; }
  public bool ReceiveMessageFromAsync(System.Net.Sockets.SocketAsyncEventArgs e) { throw null; }

src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs

@@ -1603,6 +1603,100 @@ public int ReceiveMessageFrom(byte[] buffer, int offset, int size, ref SocketFla
  return bytesTransferred;
  }
 
+ /// <summary>
+ /// Receives the specified number of bytes of data into the specified location of the data buffer,
+ /// using the specified <paramref name="socketFlags"/>, and stores the endpoint and packet information.
+ /// </summary>
+ /// <param name="buffer">
+ /// An <see cref="Span{T}"/> of type <see cref="byte"/> that is the storage location for received data.
+ /// </param>
+ /// <param name="socketFlags">
+ /// A bitwise combination of the <see cref="SocketFlags"/> values.
+ /// </param>
+ /// <param name="remoteEP">
+ /// An <see cref="EndPoint"/>, passed by reference, that represents the remote server.
+ /// </param>
+ /// <param name="ipPacketInformation">
+ /// An <see cref="IPPacketInformation"/> holding address and interface information.
+ /// </param>
+ /// <returns>
+ /// The number of bytes received.
+ /// </returns>
+ /// <exception cref="ObjectDisposedException">The <see cref="Socket"/> object has been closed.</exception>
+ /// <exception cref="ArgumentNullException">The <see cref="EndPoint"/> remoteEP is null.</exception>
+ /// <exception cref="ArgumentException">The <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in
+ /// <see cref="Socket.ReceiveMessageFrom(Span{byte}, ref SocketFlags, ref EndPoint, out IPPacketInformation)"/>
+ /// needs to match the <see cref="AddressFamily"/> of the <see cref="EndPoint"/> used in SendTo.</exception>
+ /// <exception cref="InvalidOperationException">
+ /// <para>The <see cref="Socket"/> object is not in blocking mode and cannot accept this synchronous call.</para>
+ /// <para>You must call the Bind method before performing this operation.</para></exception>
+ public int ReceiveMessageFrom(Span<byte> buffer, ref SocketFlags socketFlags, ref EndPoint remoteEP, out IPPacketInformation ipPacketInformation)
+ {
+ ThrowIfDisposed();
+
+ if (remoteEP == null)
+ {
+ throw new ArgumentNullException(nameof(remoteEP));
+ }
+ if (!CanTryAddressFamily(remoteEP.AddressFamily))
+ {
+ throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), nameof(remoteEP));
+ }
+ if (_rightEndPoint == null)
+ {
+ throw new InvalidOperationException(SR.net_sockets_mustbind);
+ }
+
+ SocketPal.CheckDualModeReceiveSupport(this);
+ ValidateBlockingMode();
+
+ // We don't do a CAS demand here because the contents of remoteEP aren't used by
+ // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
+ // with the right address family.
+ EndPoint endPointSnapshot = remoteEP;
+ Internals.SocketAddress socketAddress = Serialize(ref endPointSnapshot);
+
+ // Save a copy of the original EndPoint.
+ Internals.SocketAddress socketAddressOriginal = IPEndPointExtensions.Serialize(endPointSnapshot);
+
+ SetReceivingPacketInformation();
+
+ Internals.SocketAddress receiveAddress;
+ int bytesTransferred;
+ SocketError errorCode = SocketPal.ReceiveMessageFrom(this, _handle, buffer, ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+
+ UpdateReceiveSocketErrorForDisposed(ref errorCode, bytesTransferred);
+ // Throw an appropriate SocketException if the native call fails.
+ if (errorCode != SocketError.Success && errorCode != SocketError.MessageSize)
+ {
+ UpdateStatusAfterSocketErrorAndThrowException(errorCode);
+ }
+ else if (SocketsTelemetry.Log.IsEnabled())
+ {
+ SocketsTelemetry.Log.BytesReceived(bytesTransferred);
+ if (errorCode == SocketError.Success && SocketType == SocketType.Dgram) SocketsTelemetry.Log.DatagramReceived();
+ }
+
+ if (!socketAddressOriginal.Equals(receiveAddress))
+ {
+ try
+ {
+ remoteEP = endPointSnapshot.Create(receiveAddress);
+ }
+ catch
+ {
+ }
+ if (_rightEndPoint == null)
+ {
+ // Save a copy of the EndPoint so we can use it for Create().
+ _rightEndPoint = endPointSnapshot;
+ }
+ }
+
+ if (NetEventSource.Log.IsEnabled()) NetEventSource.Error(this, errorCode);
+ return bytesTransferred;
+ }
+
  // Receives a datagram into a specific location in the data buffer and stores
  // the end point.
  public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncContext.Unix.cs

@@ -565,6 +565,31 @@ public override void InvokeCallback(bool allowPooling) =>
  Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
  }
 
+ private sealed unsafe class BufferPtrReceiveMessageFromOperation : ReadOperation
+ {
+ public byte* BufferPtr;
+ public int Length;
+ public SocketFlags Flags;
+ public int BytesTransferred;
+ public SocketFlags ReceivedFlags;
+
+ public bool IsIPv4;
+ public bool IsIPv6;
+ public IPPacketInformation IPPacketInformation;
+
+ public BufferPtrReceiveMessageFromOperation(SocketAsyncContext context) : base(context) { }
+
+ protected sealed override void Abort() { }
+
+ public Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError>? Callback { get; set; }
+
+ protected override bool DoTryComplete(SocketAsyncContext context) =>
+ SocketPal.TryCompleteReceiveMessageFrom(context._socket, new Span<byte>(BufferPtr, Length), null, Flags, SocketAddress!, ref SocketAddressLen, IsIPv4, IsIPv6, out BytesTransferred, out ReceivedFlags, out IPPacketInformation, out ErrorCode);
+
+ public override void InvokeCallback(bool allowPooling) =>
+ Callback!(BytesTransferred, SocketAddress!, SocketAddressLen, ReceivedFlags, IPPacketInformation, ErrorCode);
+ }
+
  private sealed class AcceptOperation : ReadOperation
  {
  public IntPtr AcceptedFileDescriptor;
@@ -1696,15 +1721,15 @@ public SocketError ReceiveFromAsync(IList<ArraySegment<byte>> buffers, SocketFla
  }
 
  public SocketError ReceiveMessageFrom(
- Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ Memory<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
  {
  Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
 
  SocketFlags receivedFlags;
  SocketError errorCode;
  int observedSequenceNumber;
  if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
- (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, buffers, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer.Span, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
  !ShouldRetrySyncOperation(out errorCode)))
  {
  flags = receivedFlags;
@@ -1714,7 +1739,7 @@ public SocketError ReceiveMessageFrom(
  var operation = new ReceiveMessageFromOperation(this)
  {
  Buffer = buffer,
- Buffers = buffers,
+ Buffers = null,
  Flags = flags,
  SocketAddress = socketAddress,
  SocketAddressLen = socketAddressLen,
@@ -1731,6 +1756,45 @@ public SocketError ReceiveMessageFrom(
  return operation.ErrorCode;
  }
 
+ public unsafe SocketError ReceiveMessageFrom(
+ Span<byte> buffer, ref SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, int timeout, out IPPacketInformation ipPacketInformation, out int bytesReceived)
+ {
+ Debug.Assert(timeout == -1 || timeout > 0, $"Unexpected timeout: {timeout}");
+
+ SocketFlags receivedFlags;
+ SocketError errorCode;
+ int observedSequenceNumber;
+ if (_receiveQueue.IsReady(this, out observedSequenceNumber) &&
+ (SocketPal.TryCompleteReceiveMessageFrom(_socket, buffer, null, flags, socketAddress, ref socketAddressLen, isIPv4, isIPv6, out bytesReceived, out receivedFlags, out ipPacketInformation, out errorCode) ||
+ !ShouldRetrySyncOperation(out errorCode)))
+ {
+ flags = receivedFlags;
+ return errorCode;
+ }
+
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
+ {
+ var operation = new BufferPtrReceiveMessageFromOperation(this)
+ {
+ BufferPtr = bufferPtr,
+ Length = buffer.Length,
+ Flags = flags,
+ SocketAddress = socketAddress,
+ SocketAddressLen = socketAddressLen,
+ IsIPv4 = isIPv4,
+ IsIPv6 = isIPv6,
+ };
+
+ PerformSyncOperation(ref _receiveQueue, operation, timeout, observedSequenceNumber);
+
+ socketAddressLen = operation.SocketAddressLen;
+ flags = operation.ReceivedFlags;
+ ipPacketInformation = operation.IPPacketInformation;
+ bytesReceived = operation.BytesTransferred;
+ return operation.ErrorCode;
+ }
+ }
+
  public SocketError ReceiveMessageFromAsync(Memory<byte> buffer, IList<ArraySegment<byte>>? buffers, SocketFlags flags, byte[] socketAddress, ref int socketAddressLen, bool isIPv4, bool isIPv6, out int bytesReceived, out SocketFlags receivedFlags, out IPPacketInformation ipPacketInformation, Action<int, byte[], int, SocketFlags, IPPacketInformation, SocketError> callback, CancellationToken cancellationToken = default)
  {
  SetNonBlocking();

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs

@@ -1172,7 +1172,7 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  SocketError errorCode;
  if (!handle.IsNonBlocking)
  {
- errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), null, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(new Memory<byte>(buffer, offset, count), ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
  }
  else
  {
@@ -1187,6 +1187,33 @@ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle han
  return errorCode;
  }
 
+
+ public static SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ byte[] socketAddressBuffer = socketAddress.Buffer;
+ int socketAddressLen = socketAddress.Size;
+
+ bool isIPv4, isIPv6;
+ Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out isIPv4, out isIPv6);
+
+ SocketError errorCode;
+ if (!handle.IsNonBlocking)
+ {
+ errorCode = handle.AsyncContext.ReceiveMessageFrom(buffer, ref socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, handle.ReceiveTimeout, out ipPacketInformation, out bytesTransferred);
+ }
+ else
+ {
+ if (!TryCompleteReceiveMessageFrom(handle, buffer, null, socketFlags, socketAddressBuffer, ref socketAddressLen, isIPv4, isIPv6, out bytesTransferred, out socketFlags, out ipPacketInformation, out errorCode))
+ {
+ errorCode = SocketError.WouldBlock;
+ }
+ }
+
+ socketAddress.InternalSize = socketAddressLen;
+ receiveAddress = socketAddress;
+ return errorCode;
+ }
+
  public static SocketError ReceiveFrom(SafeSocketHandle handle, byte[] buffer, int offset, int count, SocketFlags socketFlags, byte[] socketAddress, ref int socketAddressLen, out int bytesTransferred)
  {
  if (!handle.IsNonBlocking)

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Windows.cs

@@ -451,14 +451,19 @@ public static unsafe IPPacketInformation GetIPPacketInformation(Interop.Winsock.
  }
 
  public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, byte[] buffer, int offset, int size, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
+ {
+ return ReceiveMessageFrom(socket, handle, new Span<byte>(buffer, offset, size), ref socketFlags, socketAddress, out receiveAddress, out ipPacketInformation, out bytesTransferred);
+ }
+
+ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHandle handle, Span<byte> buffer, ref SocketFlags socketFlags, Internals.SocketAddress socketAddress, out Internals.SocketAddress receiveAddress, out IPPacketInformation ipPacketInformation, out int bytesTransferred)
  {
  bool ipv4, ipv6;
  Socket.GetIPProtocolInformation(socket.AddressFamily, socketAddress, out ipv4, out ipv6);
 
  bytesTransferred = 0;
  receiveAddress = socketAddress;
  ipPacketInformation = default(IPPacketInformation);
- fixed (byte* ptrBuffer = buffer)
+ fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
  fixed (byte* ptrSocketAddress = socketAddress.Buffer)
  {
  Interop.Winsock.WSAMsg wsaMsg;
@@ -467,8 +472,8 @@ public static unsafe SocketError ReceiveMessageFrom(Socket socket, SafeSocketHan
  wsaMsg.flags = socketFlags;
 
  WSABuffer wsaBuffer;
- wsaBuffer.Length = size;
- wsaBuffer.Pointer = (IntPtr)(ptrBuffer + offset);
+ wsaBuffer.Length = buffer.Length;
+ wsaBuffer.Pointer = (IntPtr)bufferPtr;
  wsaMsg.buffers = (IntPtr)(&wsaBuffer);
  wsaMsg.count = 1;
 

src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs

@@ -54,6 +54,8 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
  [InlineData(true)]
  public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  {
+ // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
+ int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
  const int DatagramSize = 256;
  const int DatagramsToSend = 16;
 
@@ -69,7 +71,9 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  sender.BindToAnonymousPort(address);
 
  byte[] sendBuffer = new byte[DatagramSize];
- byte[] receiveBuffer = new byte[DatagramSize];
+ var receiveInternalBuffer = new byte[DatagramSize + Offset];
+ var emptyBuffer = new byte[Offset];
+ ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
  Random rnd = new Random(0);
 
  IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
@@ -83,7 +87,8 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
  IPPacketInformation packetInformation = result.PacketInformation;
 
  Assert.Equal(DatagramSize, result.ReceivedBytes);
- AssertExtensions.SequenceEqual(sendBuffer, receiveBuffer);
+ AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+ AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
  Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
  Assert.Equal(((IPEndPoint)sender.LocalEndPoint).Address, packetInformation.Address);
  }