Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Net/net/PeerToPeer/SystemNetHelpers.cs

@@ -0,0 +1,90 @@
+namespace System.Net.PeerToPeer
+{
+    using System;
+    using System.Net;
+    using System.Net.Sockets;
+    using System.Collections.Generic;
+    using System.Text;
+    using System.Security.Permissions;
+
+    internal static class SystemNetHelpers
+    {
+        internal const int IPv6AddressSize = 28;
+        internal const int IPv4AddressSize = 16;
+        internal static byte[] SOCKADDRFromIPEndPoint(IPEndPoint ipEndPoint)
+        {
+            byte[] buffer = new byte[ipEndPoint.AddressFamily == AddressFamily.InterNetworkV6 ? IPv6AddressSize : IPv4AddressSize];
+#if BIGENDIAN
+            buffer[0] = unchecked((byte)((int)family>>8));
+            buffer[1] = unchecked((byte)((int)family   ));
+#else
+            buffer[0] = unchecked((byte)((int)ipEndPoint.AddressFamily));
+            buffer[1] = unchecked((byte)((int)ipEndPoint.AddressFamily >> 8));
+#endif
+            if (ipEndPoint.AddressFamily == AddressFamily.InterNetworkV6)
+            {
+                buffer[2] = (byte)(ipEndPoint.Port >> 8);
+                buffer[3] = (byte)ipEndPoint.Port;
+
+                buffer[4] = (byte)0;
+                buffer[5] = (byte)0;
+                buffer[6] = (byte)0;
+                buffer[7] = (byte)0;
+
+                long scope = ipEndPoint.Address.ScopeId;
+                buffer[24] = (byte)scope;
+                buffer[25] = (byte)(scope >> 8);
+                buffer[26] = (byte)(scope >> 16);
+                buffer[27] = (byte)(scope >> 24);
+
+                byte[] addressBytes = ipEndPoint.Address.GetAddressBytes();
+                for (int i = 0; i < addressBytes.Length; i++)
+                {
+                    buffer[8 + i] = addressBytes[i];
+                }
+            }
+            else
+            {
+                buffer[2] = unchecked((byte)(ipEndPoint.Port >> 8));
+                buffer[3] = unchecked((byte)(ipEndPoint.Port));
+                byte[] addressBytes = ipEndPoint.Address.GetAddressBytes();
+                for (int i = 0; i < addressBytes.Length; i++)
+                {
+                    buffer[4 + i] = addressBytes[i];
+                }
+            }
+            return buffer;
+        }
+        internal static IPEndPoint IPEndPointFromSOCKADDRBuffer(byte[] buffer)
+        {
+            IPAddress ip = null;
+            int addressFamily = 0;
+#if BIGENDIAN
+            addressFamily = buffer[1] + ((int)buffer[0] << 8);
+#else
+            addressFamily = buffer[0] + ((int)buffer[1] << 8);
+#endif
+            //Get port
+            int port = buffer[3] + ((int)buffer[2] << 8);
+
+            if ((AddressFamily)addressFamily == AddressFamily.InterNetwork)
+            {
+                byte[] v4bytes = new byte[] { buffer[4], buffer[5], buffer[6], buffer[7] };
+                ip = new IPAddress(v4bytes);
+            }
+            else if ((AddressFamily)addressFamily == AddressFamily.InterNetworkV6)
+            {
+                byte[] v6Bytes = new byte[16];
+                for (int i = 0; i < 16; i++)
+                    v6Bytes[i] = buffer[8 + i];
+                long scope = ((long)(long)buffer[24] + ((long)buffer[25] << 8) + ((long)buffer[26] << 16) + ((long)buffer[27] << 24));
+                ip = new IPAddress(v6Bytes);
+                ip.ScopeId = scope;
+            }
+
+            return new IPEndPoint(ip, port);
+
+        }
+    }
+}
+