//
// System.Net.NetworkInformation.IPv4InterfaceProperties
//
// Authors:
//	Gonzalo Paniagua Javier (gonzalo@novell.com)
//	Atsushi Enomoto (atsushi@ximian.com)
//      Marek Habersack (mhabersack@novell.com)
//
// Copyright (c) 2006-2007 Novell, Inc. (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System.IO;
using System.Runtime.InteropServices;

namespace System.Net.NetworkInformation {
	public abstract class IPv4InterfaceProperties {
		protected IPv4InterfaceProperties ()
		{
		}

		public abstract int Index { get; }
		public abstract bool IsAutomaticPrivateAddressingActive { get; }
		public abstract bool IsAutomaticPrivateAddressingEnabled { get; }
		public abstract bool IsDhcpEnabled { get; }
		public abstract bool IsForwardingEnabled { get; }
		public abstract int Mtu { get; }
		public abstract bool UsesWins { get; }
	}

	abstract class UnixIPv4InterfaceProperties : IPv4InterfaceProperties
	{
		protected UnixNetworkInterface iface;
		
		public UnixIPv4InterfaceProperties (UnixNetworkInterface iface)
		{
			this.iface = iface;
		}
		
		public override int Index {
			get { return UnixNetworkInterface.IfNameToIndex (iface.Name); }
		}

		// TODO: how to discover that?
		public override bool IsAutomaticPrivateAddressingActive {
			get { return false; }
		}

		// TODO: how to discover that?
		public override bool IsAutomaticPrivateAddressingEnabled {
			get { return false; }
		}

		// TODO: how to discover that? The only way is distribution-specific...
		public override bool IsDhcpEnabled {
			get { return false; }
		}
	
		public override bool UsesWins {
			get { return false; }
		}
	}
	
	sealed class LinuxIPv4InterfaceProperties : UnixIPv4InterfaceProperties
	{
		public LinuxIPv4InterfaceProperties (LinuxNetworkInterface iface)
			: base (iface)
		{
		}
		
		public override bool IsForwardingEnabled {
			get {
				string iface_path = "/proc/sys/net/ipv4/conf/" + iface.Name + "/forwarding";

				if (File.Exists (iface_path)) {
					string val = NetworkInterface.ReadLine (iface_path);

					return val != "0";
				}

				return false;
			}
		}

		public override int Mtu {
			get {
				string iface_path = (iface as LinuxNetworkInterface).IfacePath + "mtu";
				int ret = 0;

				if (File.Exists (iface_path)) {
					string val = NetworkInterface.ReadLine (iface_path);
					
					try {
						ret = Int32.Parse (val);
					} catch {
					}
				}

				return ret;
						
			}
		}
	}

	sealed class MacOsIPv4InterfaceProperties : UnixIPv4InterfaceProperties
	{
		public MacOsIPv4InterfaceProperties (MacOsNetworkInterface iface)
			: base (iface)
		{
		}

		// dummy
		public override bool IsForwardingEnabled {
			get { return false; }
		}

		// dummy
		public override int Mtu {
			get { return 0; }
		}
	}
	
	sealed class Win32IPv4InterfaceProperties : IPv4InterfaceProperties
	{
		[DllImport ("iphlpapi.dll")]
		static extern int GetPerAdapterInfo (int IfIndex, Win32_IP_PER_ADAPTER_INFO pPerAdapterInfo, ref int pOutBufLen);

		Win32_IP_ADAPTER_INFO ainfo;
		Win32_IP_PER_ADAPTER_INFO painfo;
		Win32_MIB_IFROW mib;

		public Win32IPv4InterfaceProperties (Win32_IP_ADAPTER_INFO ainfo, Win32_MIB_IFROW mib)
		{
			this.ainfo = ainfo;
			this.mib = mib;

			// get per-adapter info.
			int size = 0;
			GetPerAdapterInfo (mib.Index, null, ref size);
			painfo = new Win32_IP_PER_ADAPTER_INFO ();
			int ret = GetPerAdapterInfo (mib.Index, painfo, ref size);
			if (ret != 0)
				throw new NetworkInformationException (ret);
		}

		public override int Index {
			get { return mib.Index; }
		}

		public override bool IsAutomaticPrivateAddressingActive {
			get { return painfo.AutoconfigActive != 0; }
		}

		public override bool IsAutomaticPrivateAddressingEnabled {
			get { return painfo.AutoconfigEnabled != 0; }
		}

		public override bool IsDhcpEnabled {
			get { return ainfo.DhcpEnabled != 0; }
		}

		public override bool IsForwardingEnabled {
			// Is it the right answer? In Vista there is MIB_IPINTERFACEROW.ForwardingEnabled, but not in former versions.
			get { return Win32_FIXED_INFO.Instance.EnableRouting != 0; }
		}

		public override int Mtu {
			get { return mib.Mtu; }
		}

		public override bool UsesWins {
			get { return ainfo.HaveWins; }
		}
	}

	[StructLayout (LayoutKind.Sequential)]
	class Win32_IP_PER_ADAPTER_INFO
	{
		public uint AutoconfigEnabled;
		public uint AutoconfigActive;
		public IntPtr CurrentDnsServer; // to Win32_IP_ADDR_STRING
		public Win32_IP_ADDR_STRING DnsServerList;
	}
}