// Copyright (c) 2006-2009 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:

// tcp.cpp - TCP protocol for IPv6/IPv4

//

#include "tcp.h"

#include <icmp6_hdr.h>

#include <ip4_hdr.h>

#include "tcpip_ini.h"

// Copied from ip6.cpp. Should move to some common definition file?

static const TLitC8<sizeof(TInt)> KInetOptionDisable = {sizeof(TInt), {0}};

//

// TCP Protocol Description

//

void CProtocolTCP6::Describe(TServerProtocolDesc &aDesc)

	{

	aDesc.iName		  = _S("tcp");

	aDesc.iAddrFamily	  = KAfInet;

	aDesc.iSockType	  = KSockStream;

	aDesc.iProtocol	  = KProtocolInetTcp;

	aDesc.iVersion	  = TVersion(KInet6MajorVersionNumber,

		KInet6MinorVersionNumber,

		KInet6BuildVersionNumber);

	aDesc.iByteOrder	  = EBigEndian;

	aDesc.iServiceInfo	  = KSIStreamBased | KSIInOrder | KSIReliable |

		KSIGracefulClose | KSIPeekData | KSIUrgentData |

		KSIRequiresOwnerInfo;

	aDesc.iNamingServices	  = KNSNameResolution | KNSRequiresConnectionStartup;

	aDesc.iSecurity	  = KSocketNoSecurity;

	aDesc.iMessageSize	  = KSocketMessageSizeIsStream;

	aDesc.iServiceTypeInfo  = ESocketSupport | ETransport | EPreferMBufChains | ENeedMBufs | EUseCanSend;

	aDesc.iNumSockets	  = KUnlimitedSockets;

	}

CProtocolTCP6::CProtocolTCP6()

	{

	__DECLARE_NAME(_S("CProtocolTCP6"));

	}

CProtocolTCP6::~CProtocolTCP6()

	{

	LOG(Log::Printf(_L("\ttcp Deleted")));

	}

CServProviderBase* CProtocolTCP6::NewSAPL(TUint aSockType)

	{

	LOG(Log::Printf(_L("NewSAPL\ttcp SockType=%d)"), aSockType));

	if (aSockType!=KSockStream)

		User::Leave(KErrNotSupported);

	CProviderTCP6 *sap = new (ELeave) CProviderTCP6(this);

	CleanupStack::PushL(sap);

	sap->InitL();

	CleanupStack::Pop();

	LOG(Log::Printf(_L("NewSAPL\ttcp SAP[%u] OK"), (TInt)sap));

	return sap;

	}

void CProtocolTCP6::InitL(TDesC& aTag)

	{

	CProtocolInet6Transport::InitL(aTag);

	iRandomIncrement = 0;

	UserHal::TickPeriod((TTimeIntervalMicroSeconds32&)iClockGranularity);

	}

void CProtocolTCP6::StartL()

	{

	CProtocolInet6Transport::StartL();

	iMSS = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_MSS,

			KTcpDefaultMSS, KTcpMinimumMSS, 65535, ETrue);

	iRecvBuf = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RECV_BUF,

			KTcpDefaultRcvWnd, KTcpMinimumWindow, KTcpMaximumWindow, ETrue); 

#ifdef SYMBIAN_ADAPTIVE_TCP_RECEIVE_WINDOW

	iRecvBufFromIniFile = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RECV_BUF,

            KTcpDefaultRcvWnd, KTcpMinimumWindow, KTcpMaximumWindow, ETrue); 

#endif //SYMBIAN_ADAPTIVE_TCP_RECEIVE_WINDOW

	iSendBuf = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_SEND_BUF,

			KTcpDefaultSndWnd, KTcpMinimumWindow, KTcpMaximumWindow, ETrue);

	// Argh: ini is in millisecs, but CProtocolTCP6 member is in microsecs.

	iMinRTO = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_MIN_RTO,

			KTcpMinRTO/1000, iClockGranularity/1000, KTcpMaxRTO/1000, ETrue) * 1000;

	iMaxRTO = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_MAX_RTO,

			KTcpMaxRTO/1000, iMinRTO/1000, KTcpMaxRTO/1000, ETrue) * 1000;

	iInitialRTO = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_INITIAL_RTO,

			KTcpInitialRTO/1000, iMinRTO/1000, iMaxRTO/1000, ETrue) * 1000;

	iSrttSmooth = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_SRTT_SMOOTH,

			KTcpSrttSmooth, 1, KMaxTInt, ETrue);

	iMdevSmooth = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RTTVAR_SMOOTH,

			KTcpMdevSmooth, 1, KMaxTInt, ETrue);

	iRTO_K = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RTO_K,

			KTcpRTO_K, 1, KMaxTInt, ETrue);

	iRTO_G = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RTO_G,

			iClockGranularity/1000, iClockGranularity/1000, KMaxTInt, ETrue) * 1000;

	iMaxBurst = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_MAX_BURST,

			KTcpMaxTransmit, 1, KMaxTInt, ETrue);

	iAckDelay = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_ACK_DELAY,

			KTcpAckDelay/1000, iClockGranularity/1000, KMaxTInt/1000, ETrue) * 1000;

	iSynRetries = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_SYN_RETRIES,

			KTcpSynRetries, 0, KMaxTInt, ETrue);

	iRetries1 = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RETRIES1,

			KTcpMaxRetries1, 0, KMaxTInt, ETrue);

	iRetries2 = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RETRIES2,

			KTcpMaxRetries2, iRetries1, KMaxTInt, ETrue);

	iProbeStyle = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_PROBE_STYLE,	2, 0, 2, EFalse);

	iMsl2Delay = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_MSL2,

			KTcpMsl2Delay/1000, 1, KMaxTInt/1000, ETrue) * 1000;

	iReordering = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_REORDERING,

			KTcpReordering, 0, KMaxTInt, ETrue);

	iInitialCwnd = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_INITIAL_CWND,

			KTcpInitialCwnd, 0, KMaxTInt, ETrue);

	iLtxWindow = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_LTX_WINDOW,

			KTcpLtxWindow, 0, KMaxTInt, ETrue);

	iKeepAliveIntv = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_KEEPALIVE_INTV,

			KTcpKeepAliveIntv, 0, KMaxTInt, ETrue);

	iNumKeepAlives = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_NUM_KEEPALIVES,

			KTcpNumKeepAlives, 0, KMaxTInt, ETrue);

	// keepalive retransmission timer cannot be longer than 30 min, because timers are in microseconds.

	iKeepAliveRxmt = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_KEEPALIVE_RXMT,

			KTcpKeepAliveRxmt, 0, 1800, ETrue);

	iFinPersistency = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_FIN_PERSISTENCY,

			KTcpFinPersistency, 0, iRetries2, ETrue);

	// ECN settings: 0 = disabled, 1 = enabled with ECT(1), 2 = enabled with ECT(0)

	iEcn = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_ECN, 0, 0, 2, EFalse);

	iSpuriousRtoResponse = GetIniValue(TCPIP_INI_TCP,

			TCPIP_INI_TCP_SPURIOUS_RTO_RESPONSE, 1, 1, 3, EFalse);

	iWinScale = (TInt8)GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_WINSCALE, 0, -1, 7, ETrue);

	// Flags enabled by default

	iTimeStamps = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_TIMESTAMPS, 1, 0, 1);

	iSack = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_SACK, 1, 0, 1);

	iRFC2414 = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RFC2414, 1, 0, 1);

	iDSack = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_DSACK, 1, 0, 1);

	iFRTO = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_FRTO, 1, 0, 1);

	// Flags disabled by default

	iLocalTimeWait = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_LOCAL_TIMEWAIT, 0, 0, 1);

	iStrictNagle = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_STRICT_NAGLE, 0, 0, 1);

	iPushAck = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_PUSH_ACK, 0, 0, 1);

	iAlignOpt = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_ALIGNOPT, 0, 0, 1);

	// Note: 'dstcache' is in [ip] section, because it is not necessarily TCP specific

	iDstCache = GetIniValue(TCPIP_INI_IP, TCPIP_INI_DSTCACHE, 0, 0, 1);

#ifdef SYMBIAN_ADAPTIVE_TCP_RECEIVE_WINDOW

	iTcpMaxRecvWin = GetIniValue(TCPIP_INI_TCP, TCPIP_INI_TCP_RECV_MAX_WND,

				KTcpDefaultRcvMaxWnd, KTcpMinimumWindow, KTcpMaximumWindow, ETrue);

#endif //SYMBIAN_ADAPTIVE_TCP_RECEIVE_WINDOW

	}

void CProtocolTCP6::Identify(TServerProtocolDesc *aInfo) const

	{

	Describe(*aInfo);

	}

TInt CProtocolTCP6::Send(RMBufChain& aPacket,CProtocolBase* /*aSourceProtocol=NULL*/)

	{

#ifdef _LOGx

	RMBufSendPacket seg;

	seg.Assign(aPacket);

	RMBufSendInfo *info = seg.Unpack();

	LOG(LogPacket('>', seg, info));

	seg.Pack();

	aPacket.Assign(seg);

#endif

	return iNetwork->Send(aPacket);

	}

void CProtocolTCP6::Process(RMBufChain& aPacket, CProtocolBase* /*aSourceProtocol*/)

	{

	RMBufRecvPacket seg;

	seg.Assign(aPacket);

	//  RMBufRecvPacket& seg = (RMBufRecvPacket&)aPacket;

	RMBufRecvInfo* info = seg.Unpack();

#ifdef _LOG

	TBuf<50> src, dst;

	LOG(Log::Printf(_L("\ttcp Process(%d bytes)"), seg.Length()));

#endif

	ASSERT(info->iLength == seg.Length());

	TTcpPacket pkt;

	TInet6Packet<TInet6HeaderIP4> ip4;

	TInet6Packet<TInet6HeaderIP>  ip6;

	TInt err = KErrNone, errMask = MSocketNotify::EErrorAllOperations;

	CProviderTCP6 *sap;

	TInetAddr icmpSender;

	switch (info->iIcmp)

		{

	case 0:

		// Check source and destination addresses

		if (!(TInetAddr::Cast(info->iDstAddr).IsUnicast() && TInetAddr::Cast(info->iSrcAddr).IsUnicast()))

			{

			LOG(Log::Printf(_L("\ttcpProcess() Invalid source or destination address. Packet discarded")));

			seg.Free();

			break;

			}

		pkt.Set(seg, info->iOffset, KTcpMinHeaderLength);

		// Verify header length.

		if (!pkt.iHdr || info->iLength < pkt.iHdr->HeaderLength())

			{

			LOG(Log::Printf(_L("\ttcp Process() Invalid header. Packet discarded")));

			seg.Free();

			return;

			}

		// Get port numbers from header

		info->iSrcAddr.SetPort(pkt.iHdr->SrcPort());

		info->iDstAddr.SetPort(pkt.iHdr->DstPort());

#ifdef _LOG

		LogPacket('<', seg, info, info->iOffset);

		pkt.Set(seg, info->iOffset, pkt.iHdr->HeaderLength()); // LogPacket() may have realigned the header.

#endif

		// Verify TCP checksum

		if (!pkt.VerifyChecksum(seg, info, info->iOffset))

			{

			LOG(Log::Printf(_L("\ttcp Process() Bad checksum. Packet discarded")));

			seg.Free();

			break;

			}

#ifdef _LOGx

		TInetAddr(info->iSrcAddr).OutputWithScope(src); TInetAddr(info->iDstAddr).Output(dst);

		LOG(Log::Printf(_L("\ttcp Process(%d bytes): {%S,%d} -> {%S,%d}"),

			seg.Length(), &src, info->iSrcAddr.Port(), &dst, info->iDstAddr.Port()));

#endif

		// More sanity checking.

		if (info->iSrcAddr.Port() == KInetPortNone ||

			info->iDstAddr.Port() == KInetPortNone)

			{

			LOG(Log::Printf(_L("\ttcp Process() Illegal port number. Packet discarded")));

			seg.Free();

			break;

			}

		sap = (CProviderTCP6*)LocateSap(EMatchServerUnspecAddr,

			info->iVersion == 4 ? KAfInet : KAfInet6,

#ifndef SYMBIAN_STRICT_EXPLICIT_SOCKET_BINDING

			info->iDstAddr, info->iSrcAddr);

#else

			info->iDstAddr, info->iSrcAddr, NULL, info->iInterfaceIndex);

#endif //SYMBIAN_STRICT_EXPLICIT_SOCKET_BINDING

		if (sap == NULL)

			{

			LOG(Log::Printf(_L("\ttcp Process() No socket. Packet discarded")));

			if (!pkt.iHdr->RST())

				{

				//

				// Send RST.

				//

				if (NetworkService()->Interfacer()->LocalScope(TInetAddr::Cast(info->iDstAddr).Ip6Address(),

					info->iInterfaceIndex, EScopeType_IF))

					{

					if (pkt.iHdr->ACK())

						{

						SendControlSegment(NULL, info->iDstAddr, info->iSrcAddr, KTcpCtlRST,

							pkt.iHdr->Acknowledgment(), 0);

						}

					else

						{

						//TTcpSeqNum seq = pkt.iHdr->Sequence() + aPacket.Length() - pkt.iHdr->HeaderLength();

						TTcpSeqNum seq = pkt.iHdr->Sequence() + seg.Length() -

							pkt.iHdr->HeaderLength() - info->iOffset;

						// Adjust for SYN and FIN

						if (pkt.iHdr->SYN() || pkt.iHdr->FIN())

							seq++;

						SendControlSegment(NULL, info->iDstAddr, info->iSrcAddr, KTcpCtlRST|KTcpCtlACK, 0, seq);

						}

					}

				}

			seg.Free();

			break;

			}

		// Bump it to the SAP.

		seg.Pack();

		sap->Process(seg);

		break;

	case KProtocolInetIcmp:

	case KProtocolInet6Icmp:

        /* From RFC1122:

        4.2.3.9  ICMP Messages

            TCP MUST act on an ICMP error message passed up from the IP

            layer, directing it to the connection that created the

            error.  The necessary demultiplexing information can be

            found in the IP header contained within the ICMP message.

            o    Source Quench

                 TCP MUST react to a Source Quench by slowing

                 transmission on the connection.  The RECOMMENDED

                 procedure is for a Source Quench to trigger a "slow

                 start," as if a retransmission timeout had occurred.

            o    Destination Unreachable -- codes 0, 1, 5

                 Since these Unreachable messages indicate soft error

                 conditions, TCP MUST NOT abort the connection, and it

                 SHOULD make the information available to the

                 application.

                 DISCUSSION:

                      TCP could report the soft error condition directly

                      to the application layer with an upcall to the

                      ERROR_REPORT routine, or it could merely note the

                      message and report it to the application only when

                      and if the TCP connection times out.

            o    Destination Unreachable -- codes 2-4

                 These are hard error conditions, so TCP SHOULD abort

                 the connection.

            o    Time Exceeded -- codes 0, 1

                 This should be handled the same way as Destination

                 Unreachable codes 0, 1, 5 (see above).

            o    Parameter Problem

                 This should be handled the same way as Destination

		Unreachable codes 0, 1, 5 (see above).*/

		//

		// Map the first 8 bytes of TCP segment header

		// (8 bytes is all there is in an ICMPv4 packet)

		//

		// WARNING!!!   Any attempt to access fields other than

		//              SrcPort, DstPort, or Sequence WILL CAUSE

		//              BAD THINGS TO HAPPEN!

		//

		//

		pkt.Set(seg, info->iOffset, 8);

		if (!pkt.iHdr)

			{

			LOG(Log::Printf(_L("\ttcp Process() Invalid TCP header in ICMP")));

			seg.Free();

			break;

			}

		// Get port numbers from header

		info->iSrcAddr.SetPort(pkt.iHdr->SrcPort());

		info->iDstAddr.SetPort(pkt.iHdr->DstPort());

#ifdef _LOG

		TInetAddr(info->iSrcAddr).OutputWithScope(src); TInetAddr(info->iDstAddr).OutputWithScope(dst);

		LOG(Log::Printf(_L("\ttcp Process() ICMP reply to TCP segment {%S,%d} -> {%S,%d}"),

			&src, info->iSrcAddr.Port(), &dst, info->iDstAddr.Port()));

		LOG(Log::Printf(_L("\ttcp Process() ICMP type=%d code=%d param=%d received"),

			info->iType, info->iCode, info->iParameter));

#endif

		sap = (CProviderTCP6*)LocateSap(EMatchServerUnspecAddr,

			info->iVersion == 4 ? KAfInet : KAfInet6,

			info->iSrcAddr, info->iDstAddr);

		if (sap == NULL)

			{

			LOG(Log::Printf(_L("\ttcp Process() No socket. Discarding ICMP message")));

			seg.Free();

			break;

			}

		if (info->iIcmp == KProtocolInetIcmp)

			{

			//

			// ICMPv4 message processing

			//

			ip4.Set(seg, 0, TInet6HeaderIP4::MinHeaderLength());

			if (!ip4.iHdr)

				{

				LOG(Log::Printf(_L("\ttcp SAP[%u] Invalid IPv4 header in ICMP"), (TInt)sap));

				seg.Free();

				break;

				}

			icmpSender.SetAddress(ip4.iHdr->SrcAddr());

			switch (info->iType)

				{

			case KInet4ICMP_Unreachable:

/*

   Code           0 = net unreachable

                  1 = host unreachable

                  2 = protocol unreachable

                  3 = port unreachable

                  4 = fragmentation needed and DF set

                  5 = source route failed

                  6 = destination network unknown

                  7 = destination host unknown

                  8 = source host isolated

                  9 = communication with destination network administratively prohibited

                 10 = communication with destination host administratively prohibited

                 11 = network unreachable for type of service

                 12 = host unreachable for type of service

				*/

				switch (info->iCode)

					{

				case 2:

					err = KErrNoProtocolOpt;

					break;

				case 3:

					err = KErrCouldNotConnect;

					break;

				case 0:                          // Transient condition

					errMask = 0;

					// Fall through

				case 5: case 6: case 8: case 9:  // Persistent conditions

					err = KErrNetUnreach;

					break;

				case 1:                          // Transient condition

					errMask = 0;

					// Fall through

				case 7: case 10: case 12:        // Persistent conditions

					err = KErrHostUnreach;

					break;

				default:

					break;

					}

				break;

			case KInet4ICMP_SourceQuench:        // Do a slow start

				sap->SourceQuench();

				break;

			case KInet4ICMP_TimeExceeded:

				err = KErrNetUnreach;

				errMask = 0;

				break;

			case KInet4ICMP_ParameterProblem:

				err = KErrArgument;

				errMask = 0;

				break;

			default:

				break;

				}

			}

		else

			{

			//

			// ICMPv6 message processing

			//

			ip6.Set(seg, 0, TInet6HeaderIP::MinHeaderLength());

			if (!ip6.iHdr)

				{

				LOG(Log::Printf(_L("\ttcp SAP[%u] Invalid IPv6 header in ICMP"), (TInt)sap));

				seg.Free();

				break;

				}

			icmpSender.SetAddress(ip6.iHdr->SrcAddr());

			switch (info->iType)

				{

			case KInet6ICMP_Unreachable:

/*

   Code           0 - no route to destination