// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// ip6_rth.cpp - default hook for IPv6 routing header

//

#include <ext_hdr.h>

#include "ip6_rth.h"

#include <in_pkt.h>

#include <icmp6_hdr.h>

#include "addr46.h"

//

// CRoutingHeaderHook::InitL

//

void CRoutingHeaderHook::ConstructL()

	{

	iProtocol->BindL(this, BindHookFor(KProtocolInet6RoutingHeader));

	}

//

// CRoutingHeaderHook::ApplyL

//

//

TInt CRoutingHeaderHook::ApplyL(RMBufHookPacket &aPacket, RMBufRecvInfo &aInfo)

	{

	if (aInfo.iVersion == 4)

		{

		//

		// Do not process RTH for IPv4. Returning PASS

		// will cause the main loop eventually to treat this

		// as unknown header, if nothing else handles it.

		//

		return KIp6Hook_PASS;

		}

	for (;;)	// .. just for easy error exits with "break"!

		{

		TInet6Packet<TInet6HeaderRouting> rt(aPacket, aInfo.iOffset);

		if (rt.iHdr == NULL)

			break;			// Not enough for even the basic part, drop packet!

		//

		const TInt hdrlen = aInfo.CheckL(rt.iHdr->HeaderLength());

		const TInt next_header = rt.iHdr->NextHeader();

		//

		// The iIcmp decides whether this is a normal Routing Header or

		// some error report relating to such...

		//

		if (aInfo.iIcmp == 0)

			{

			TInt left = rt.iHdr->SegmentsLeft(); // Always >= 0!

			if (left == 0)

				{

				//

				// Remove routing header

				//

				aInfo.iProtocol = next_header;

				aInfo.iPrevNextHdr = (TUint16)aInfo.iOffset;	// Next Header is at +0 in RTH.

				aInfo.iOffset += hdrlen;

				return KIp6Hook_DONE;

				}

			if (rt.iHdr->RoutingType() != 0)

				{

				// Unknown routing type, with segments left > 0! Must send

				// parameter problem, Code = 0 and point to type.

				//

				iProtocol->Icmp6Send(aPacket, KInet6ICMP_ParameterProblem, 0,

					aInfo.iOffset + TInet6HeaderRouting::O_RoutingType);

				return -1;

				}

			TInt extlen = rt.iHdr->HdrExtLen();	// Always >= 0!

			if (extlen & 1)

				{

				//

				// Odd length, need to send ICMP parameter problem, Code = 0

				// and point to Hdr Ext Len.

				// --- not correct, if we allowed RTH within IPv4! -- msa

				iProtocol->Icmp6Send(aPacket, KInet6ICMP_ParameterProblem, 0,

					aInfo.iOffset + TInet6HeaderRouting::O_HdrExtLen);

				return -1;

				}

			extlen >>= 1;	// = number of addresses

			extlen -= left;	// index of the next address

			if (extlen < 0)

				{

				// --- not correct, if we allowed RTH within IPv4! -- msa

				iProtocol->Icmp6Send(aPacket, KInet6ICMP_ParameterProblem, 0,

					aInfo.iOffset + TInet6HeaderRouting::O_SegmentsLeft);

				return -1;

				}

			rt.iHdr->SetSegmentsLeft(left-1);

			extlen = (extlen << 3) + TInet6HeaderRouting::O_Address;	// = offset to the address.

			TIp6Addr address;

			TPtr8 ptr((TUint8 *)(&address), sizeof(TIp6Addr), sizeof(TIp6Addr));

			aPacket.CopyOut(ptr, aInfo.iOffset + extlen);

			if (ptr.Length() != sizeof(TIp6Addr))

				break;	// Bad Packet

			if (TIp46Addr::Cast(address).IsMulticast() ||

				TIp46Addr::Cast(TInetAddr::Cast(aInfo.iDstAddr).Ip6Address()).IsMulticast())

				break;	// Bad RTH! Send ICMP ?

			//

			// Do the address swap

			// -- update IPv6 header (destination address)

			aPacket.CopyIn(ptr, aInfo.iOffsetIp + TInet6HeaderIP::O_DstAddr);

			// -- swap info dest and routing header

			ptr.Set((TUint8 *)&(TInetAddr::Cast(aInfo.iDstAddr).Ip6Address()), sizeof(TIp6Addr), sizeof(TIp6Addr));

			aPacket.CopyIn(ptr, aInfo.iOffset + extlen);

			TInetAddr::Cast(aInfo.iDstAddr).SetAddress(address);

			// HopLimit decrements from here, because it is automaticly

			// decreased by the forwarding action. However, if the address from

			// the routing header is still for this host, then hoplimit does not

			// affect it. Should it? Does this break any RFC? -- msa

			//

			// All done, resubmit by leaving the header in

			//

			aInfo.iFlags &= ~KIpAddressVerified;	// Force destination address check!

			return KIp6Hook_DONE;

			}

		else if (aInfo.iIcmp == KProtocolInet6Icmp)

			{

			//

			// ICMP6 Error report

			//

			const TInt offset = aInfo.iOffset - aInfo.iOffsetIp;// Relative offset within problem packet

			if (aInfo.iType == KInet6ICMP_ParameterProblem &&	// A parameter problem...

				offset <= (TInt)aInfo.iParameter &&		// after start of this header?

				offset + hdrlen > (TInt)aInfo.iParameter)	// and before end of this header?

				break;	// ICMP Paremeter error in routing header, just drop for now.

			//

			// Remove routing header, pass error processing to the next header

			//

			aInfo.iPrevNextHdr = (TUint16)aInfo.iOffset;	// next_header is at +0 in RTH!

			aInfo.iProtocol = next_header;

			aInfo.iOffset += hdrlen;

			return KIp6Hook_DONE;

			}

		//

		// ICMP4 Error report (or something weird)

		//

		// * just drop it*

		//

		break;

		}

	//

	// On any problem, get here and do the drop packet return

	//

	aPacket.Free();

	return -1;

	};