C# Definition:

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    internal struct sockaddr
    {
        internal EnumLib.ADDRESS_FAMILIES sa_family;

        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)] internal String sa_data;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    internal unsafe struct sockaddr_UNSAFE
    {
        internal EnumLib.ADDRESS_FAMILIES sa_family;
        internal fixed char sa_data [14];

        internal string Name
        {
        get
        {
            var result = string.Empty;
            fixed (char* str = sa_data)
            {
            result = new string(str);
            }
            return result;
        }
        }
    }

Notes:

None.

Conversion of sockaddr to IPAddress:

public enum SockAddrFamily

{

  Inet = 2,
  Inet6 = 23

}

[StructLayout(LayoutKind.Sequential)]

public struct SockAddr

{

  public ushort Family;
  [MarshalAs(UnmanagedType.ByValArray, SizeConst = 14)]
  public byte[] Data;

};

[StructLayout(LayoutKind.Sequential)]

public struct SockAddrIn

{

  public ushort Family;
  public ushort Port;
  public uint Addr;
  [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
  public byte[] Zero;

}

[StructLayout(LayoutKind.Sequential)]

public struct SockAddrIn6

{

  public ushort Family;
  public ushort Port;
  public uint FlowInfo;
  [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
  public byte[] Addr;
  public uint ScopeId;

};

public IPAddress ConvertSockAddrPtrToIPAddress(IntPtr sockAddrPtr)

{

  SockAddr sockAddr = (SockAddr)Marshal.PtrToStructure(sockAddrPtr, typeof(SockAddr));
  switch ((SockAddrFamily)sockAddr.Family)
  {
    case SockAddrFamily.Inet:
    {
      SockAddrIn sockAddrIn = (SockAddrIn)Marshal.PtrToStructure(sockAddrPtr, typeof(SockAddrIn));
      return new IPAddress(sockAddrIn.Addr);
    }
    case SockAddrFamily.Inet6:
    {
      SockAddrIn6 sockAddrIn6 = (SockAddrIn6)Marshal.PtrToStructure(sockAddrPtr, typeof(SockAddrIn6));
      return new IPAddress(sockAddrIn6.Addr);
    }
    default:
      throw new Exception(string.Format("Non-IP address family: {0}", sockAddr.Family));
  }

}