add ReceiveFromAsync and SendToAsync with SocketAddress overload

src/libraries/Common/src/System/Net/IPEndPointExtensions.cs

@@ -58,5 +58,34 @@ public static void Serialize(this IPEndPoint endPoint, Span<byte> destination)
             SetIPAddress(destination, endPoint.Address);
             SocketAddressPal.SetPort(destination, (ushort)endPoint.Port);
         }
+
+        public static bool Equals(this IPEndPoint endPoint, ReadOnlySpan<byte> socketAddressBuffer)
+        {
+            if (socketAddressBuffer.Length >= SocketAddress.GetMaximumAddressSize(endPoint.AddressFamily) &&
+                endPoint.AddressFamily == SocketAddressPal.GetAddressFamily(socketAddressBuffer) &&
+                endPoint.Port == (int)SocketAddressPal.GetPort(socketAddressBuffer))
+            {
+                if (endPoint.AddressFamily == AddressFamily.InterNetwork)
+                {
+#pragma warning disable CS0618
+                    return endPoint.Address.Address == (long)SocketAddressPal.GetIPv4Address(socketAddressBuffer);
+#pragma warning restore CS0618
+                }
+                else
+                {
+                    Span<byte> addressBuffer1 = stackalloc byte[IPAddressParserStatics.IPv6AddressBytes];
+                    Span<byte> addressBuffer2 = stackalloc byte[IPAddressParserStatics.IPv6AddressBytes];
+                    SocketAddressPal.GetIPv6Address(socketAddressBuffer, addressBuffer1, out uint scopeid);
+                    if (endPoint.Address.ScopeId != (long)scopeid)
+                    {
+                        return false;
+                    }
+                    endPoint.Address.TryWriteBytes(addressBuffer2, out _);
+                    return addressBuffer1.SequenceEqual(addressBuffer2);
+                }
+            }
+
+            return false;
+        }
     }
 }

src/libraries/Common/src/System/Net/SocketAddress.cs

@@ -1,26 +1,14 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Buffers.Binary;
 using System.Diagnostics;
-using System.Globalization;
 using System.Net.Sockets;
-using System.Text;
 
-#if SYSTEM_NET_PRIMITIVES_DLL
 namespace System.Net
-#else
-namespace System.Net.Internals
-#endif
 {
     // This class is used when subclassing EndPoint, and provides indication
     // on how to format the memory buffers that the platform uses for network addresses.
-#if SYSTEM_NET_PRIMITIVES_DLL
-    public
-#else
-    internal sealed
-#endif
-    class SocketAddress : System.IEquatable<SocketAddress>
+    public class SocketAddress : IEquatable<SocketAddress>
     {
 #pragma warning disable CA1802 // these could be const on Windows but need to be static readonly for Unix
         internal static readonly int IPv6AddressSize = SocketAddressPal.IPv6AddressSize;
@@ -52,7 +40,7 @@ public int Size
             set
             {
                 ArgumentOutOfRangeException.ThrowIfGreaterThan(value, _buffer.Length);
-                ArgumentOutOfRangeException.ThrowIfLessThan(value, MinSize);
+                ArgumentOutOfRangeException.ThrowIfLessThan(value, 0);
                 _size = value;
             }
         }
@@ -137,13 +125,6 @@ internal SocketAddress(IPAddress ipaddress, int port)
             SocketAddressPal.SetPort(_buffer, unchecked((ushort)port));
         }
 
-        internal SocketAddress(AddressFamily addressFamily, ReadOnlySpan<byte> buffer)
-        {
-            _buffer = buffer.ToArray();
-            _size = _buffer.Length;
-            SocketAddressPal.SetAddressFamily(_buffer, addressFamily);
-        }
-
         /// <summary>This represents underlying memory that can be passed to native OS calls.</summary>
         /// <remarks>
         /// Content of the memory can be invalidated if <see cref="Size"/> is changed or if the SocketAddress is used in another receive call.
@@ -152,44 +133,10 @@ public Memory<byte> Buffer
         {
             get
             {
-                return new Memory<byte>(_buffer, 0, _size);
-            }
-        }
-
-        internal IPAddress GetIPAddress()
-        {
-            if (Family == AddressFamily.InterNetworkV6)
-            {
-                Debug.Assert(Size >= IPv6AddressSize);
-
-                Span<byte> address = stackalloc byte[IPAddressParserStatics.IPv6AddressBytes];
-                uint scope;
-                SocketAddressPal.GetIPv6Address(_buffer, address, out scope);
-
-                return new IPAddress(address, (long)scope);
-            }
-            else if (Family == AddressFamily.InterNetwork)
-            {
-                Debug.Assert(Size >= IPv4AddressSize);
-                long address = (long)SocketAddressPal.GetIPv4Address(_buffer) & 0x0FFFFFFFF;
-                return new IPAddress(address);
-            }
-            else
-            {
-#if SYSTEM_NET_PRIMITIVES_DLL
-                throw new SocketException(SocketError.AddressFamilyNotSupported);
-#else
-                throw new SocketException((int)SocketError.AddressFamilyNotSupported);
-#endif
+                return new Memory<byte>(_buffer);
             }
         }
 
-        internal int GetPort() => (int)SocketAddressPal.GetPort(_buffer);
-
-        internal IPEndPoint GetIPEndPoint()
-        {
-            return new IPEndPoint(GetIPAddress(), GetPort());
-        }
 
         public override bool Equals(object? comparand) =>
             comparand is SocketAddress other && Equals(other);

src/libraries/Common/src/System/Net/SocketAddressExtensions.cs

@@ -0,0 +1,37 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics;
+using System.Net;
+
+namespace System.Net.Sockets
+{
+    internal static partial class SocketAddressExtensions
+    {
+        public static IPAddress GetIPAddress(this SocketAddress socketAddress) => IPEndPointExtensions.GetIPAddress(socketAddress.Buffer.Span);
+        public static int GetPort(this SocketAddress socketAddress)
+        {
+            Debug.Assert(socketAddress.Family == AddressFamily.InterNetwork || socketAddress.Family == AddressFamily.InterNetworkV6);
+            return (int)SocketAddressPal.GetPort(socketAddress.Buffer.Span);
+        }
+
+        public static IPEndPoint GetIPEndPoint(this SocketAddress socketAddress)
+        {
+            return new IPEndPoint(socketAddress.GetIPAddress(), socketAddress.GetPort());
+        }
+
+        public static bool Equals(this SocketAddress socketAddress, EndPoint? endPoint)
+        {
+            if (socketAddress.Family == endPoint?.AddressFamily && endPoint is IPEndPoint ipe)
+            {
+                return ipe.Equals(socketAddress.Buffer.Span);
+            }
+
+            // We could serialize other EndPoints and compare socket addresses.
+            // But that would do two allocations and is probably as expensive as
+            // allocating new EndPoint.
+            // This may change if https://github.com/dotnet/runtime/issues/78993 is done
+            return false;
+        }
+    }
+}

src/libraries/Common/src/System/Net/SocketProtocolSupportPal.Unix.cs

@@ -8,6 +8,8 @@ namespace System.Net
 {
     internal static partial class SocketProtocolSupportPal
     {
+        private const int DgramSocketType = 2;
+
         private static unsafe bool IsSupported(AddressFamily af)
         {
             // Check for AF_UNIX on iOS/tvOS. The OS claims to support this, but returns EPERM on bind.

src/libraries/Common/src/System/Net/SocketProtocolSupportPal.Windows.cs

@@ -10,13 +10,14 @@ internal static partial class SocketProtocolSupportPal
     {
         private static bool IsSupported(AddressFamily af)
         {
+            const int StreamSocketType = 1;
             Interop.Winsock.EnsureInitialized();
 
             IntPtr INVALID_SOCKET = (IntPtr)(-1);
             IntPtr socket = INVALID_SOCKET;
             try
             {
-                socket = Interop.Winsock.WSASocketW(af, DgramSocketType, 0, IntPtr.Zero, 0, (int)Interop.Winsock.SocketConstructorFlags.WSA_FLAG_NO_HANDLE_INHERIT);
+                socket = Interop.Winsock.WSASocketW(af, StreamSocketType, 0, IntPtr.Zero, 0, (int)Interop.Winsock.SocketConstructorFlags.WSA_FLAG_NO_HANDLE_INHERIT);
                 return
                     socket != INVALID_SOCKET ||
                     (SocketError)Marshal.GetLastPInvokeError() != SocketError.AddressFamilyNotSupported;

src/libraries/Common/src/System/Net/SocketProtocolSupportPal.cs

@@ -14,8 +14,6 @@ internal static partial class SocketProtocolSupportPal
         public static bool OSSupportsIPv4 { get; } = IsSupported(AddressFamily.InterNetwork);
         public static bool OSSupportsUnixDomainSockets { get; } = IsSupported(AddressFamily.Unix);
 
-        private const int DgramSocketType = 2;
-
         private static bool IsIPv6Disabled()
         {
             // First check for the AppContext switch, giving it priority over the environment variable.

src/libraries/Common/src/System/Net/Sockets/ProtocolType.cs

@@ -1,15 +1,9 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-#if SYSTEM_NET_SOCKETS_DLL
 namespace System.Net.Sockets
 {
     public
-#else
-namespace System.Net.Internals
-{
-    internal
-#endif
     // Specifies the protocols that the Socket class supports.
     enum ProtocolType
     {

src/libraries/Common/src/System/Net/Sockets/SocketType.cs

@@ -1,15 +1,9 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-#if SYSTEM_NET_SOCKETS_DLL
 namespace System.Net.Sockets
 {
     public
-#else
-namespace System.Net.Internals
-{
-    internal
-#endif
     // Specifies the type of socket an instance of the System.Net.Sockets.Socket class represents.
     enum SocketType
     {

src/libraries/System.Net.Primitives/src/System.Net.Primitives.csproj

@@ -60,6 +60,8 @@
              Link="Common\System\Net\CookieParser.cs" />
     <Compile Include="$(CommonPath)System\Net\IPAddressParserStatics.cs"
              Link="Common\System\Net\IPAddressParserStatics.cs" />
+    <Compile Include="$(CommonPath)System\Net\IPEndPointExtensions.cs"
+                 Link="Common\System\Net\IPEndPointExtensions.cs" />
     <Compile Include="$(CommonPath)System\Net\HttpKnownHeaderNames.cs"
              Link="Common\System\Net\HttpKnownHeaderNames.cs" />
     <Compile Include="$(CommonPath)System\Net\TcpValidationHelpers.cs"
@@ -68,6 +70,8 @@
              Link="Common\System\Net\UriScheme.cs" />
     <Compile Include="$(CommonPath)System\Net\SocketAddress.cs"
              Link="Common\System\Net\SocketAddress.cs" />
+    <Compile Include="$(CommonPath)System\Net\SocketAddressExtensions.cs"
+             Link="Common\System\Net\SocketAddressExtensions.cs" />
     <Compile Include="$(CommonPath)System\Net\NegotiationInfoClass.cs"
              Link="Common\System\Net\NegotiationInfoClass.cs" />
     <Compile Include="$(CommonPath)System\Net\NetworkInformation\HostInformation.cs"

src/libraries/System.Net.Primitives/tests/FunctionalTests/SocketAddressTest.cs

@@ -48,9 +48,8 @@ public static void AddressFamily_Size_Correct()
         {
             SocketAddress sa = new SocketAddress(AddressFamily.InterNetwork);
             Assert.Throws<ArgumentOutOfRangeException>(() => sa.Size = sa.Size + 1);
-
-            sa.Size = 4;
-            Assert.Equal(4, sa.Buffer.Length);
+            sa.Size = 0;
+            Assert.Throws<ArgumentOutOfRangeException>(() => sa.Size = - 1);
         }
 
         [Fact]

src/libraries/System.Net.Primitives/tests/PalTests/System.Net.Primitives.Pal.Tests.csproj

@@ -39,6 +39,10 @@
              Link="Common\System\HexConverter.cs" />
     <Compile Include="$(CommonPath)System\Obsoletions.cs"
              Link="Common\System\Obsoletions.cs" />
+    <Compile Include="$(CommonPath)System\Net\IPEndPointExtensions.cs"
+             Link="Common\System\Net\IPEndPointExtensions.cs" />
+    <Compile Include="$(CommonPath)System\Net\SocketAddressExtensions.cs"
+             Link="Common\System\Net\SocketAddressExtensions.cs" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="HostInformationPalTest.cs" />

src/libraries/System.Net.Primitives/tests/UnitTests/System.Net.Primitives.UnitTests.Tests.csproj

@@ -50,6 +50,10 @@
              Link="Common\System\HexConverter.cs" />
     <Compile Include="$(CommonPath)System\Obsoletions.cs"
              Link="Common\System\Obsoletions.cs" />
+    <Compile Include="$(CommonPath)System\Net\IPEndPointExtensions.cs"
+             Link="Common\System\Net\IPEndPointExtensions.cs" />
+    <Compile Include="$(CommonPath)System\Net\SocketAddressExtensions.cs"
+             Link="Common\System\Net\SocketAddressExtensions.cs" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CookieCollectionTest.cs" />