telephonyprotocols/rawipnif/version1/src/IPv4ProtocolIf.cpp
changeset 0 3553901f7fa8
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/telephonyprotocols/rawipnif/version1/src/IPv4ProtocolIf.cpp	Tue Feb 02 01:41:59 2010 +0200
@@ -0,0 +1,776 @@
+// Copyright (c) 2002-2009 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:
+// This file implements the CIPv4ProtocolIf class, which handles the transmission
+// of IPv4 data to and from the TCP/IP stack.
+// 
+//
+
+/**
+ @file
+*/
+
+#include <etelpckt.h>
+#include <in_iface.h>
+#include "RawIPNifMain.h"
+#include "IPv4ProtocolIf.h"
+#ifdef WCDMA_STUB
+#include <UMTSNifControlIf.h>
+#endif
+#define LOG_IP_ADDRESS(desc,addr) _LOG_L2C5(_L8("    " desc " = %d.%d.%d.%d from context"), \
+			addr >> 24, (addr >> 16) & 0xFF, (addr >> 8) & 0xFF, addr & 0xFF);
+
+CIPv4ProtocolIf::CIPv4ProtocolIf(CRawIPNifMain& aNifMain, CBttLogger* aTheLogger)
+/**
+ * Constructor
+ */ 
+	: CProtocolIfBase(aNifMain,aTheLogger),
+	  iTheLogger(aTheLogger), 
+	  iSpeedMetric(KDefaultSpeedMetric)
+	{
+	}
+
+CIPv4ProtocolIf::~CIPv4ProtocolIf()
+/**
+ *	Destructor
+ */
+	{
+	}
+
+void CIPv4ProtocolIf::BindL(TAny* aId)
+/**
+ *	Binds protocol to the Nif
+ *
+ *	@param aId A point the the protocol(TCP/IP)
+ */
+	{
+	_LOG_L1C2(_L8("CIPv4ProtocolIf::BindL [aId=%X]"), aId);
+
+	CProtocolIfBase::BindL(aId); // Call the superclass's method.
+	iNotify = iNifMain.Notify();
+	}
+
+TInt CIPv4ProtocolIf::Control(TUint aLevel, TUint aName, TDes8& aOption,
+							TAny* /*aSource*/)
+/**
+ * The main function called by the TCP/IP protocol to control the interface.
+ * Can perform a variety of general IP tasks (such as getting IP config)
+ * and "3G" specific tasks (such as deleting the context).
+ *
+ * @param aLevel The level of the interface to control - always KSOLInterface
+ * @param aName The command to perform
+ * @param aOption Data to be input/output as a result of the command
+ * @param aSource The source of the command (unused)
+ * @return Standard error codes
+ */
+	{
+	_LOG_L1C3(_L8("CIPv4ProtocolIf::Control [aLevel=%d, aName=%d]"),
+		aLevel, aName);
+
+	if (aLevel == KSOLInterface)
+		{
+		switch (aName)
+			{
+		// General IP configuration commands are below this point.
+
+		case KSoIfInfo:
+			// Gets information about the interface, such as name and MTU.
+			return WriteIfInfo(aOption);
+
+		case KSoIfConfig:
+			// Gets interface configuration, eg. IP address and DNS servers.
+			return WriteIfConfig(aOption);
+
+		case KSoIfGetConnectionInfo:
+			// Gets IAP and network information.
+			return WriteConnectionInfo(aOption);
+
+		case KSoIfHardwareAddr:
+			// unsupported because we don't have a h/w address
+		case KSoIfCompareAddr:
+			// this never actually appears to be called
+			break;
+
+		// 3G-specific configuration commands are below this point.
+#ifdef WCDMA_STUB
+		case KRegisterEventHandler:
+			// Raw IP NIF Events are not supported
+		case KContextSetEvents:
+			// Raw IP NIF Events are not supported
+			break;
+
+		case KContextCreate:
+			// We don't support creating new secondary contexts.
+			break;
+
+		case KContextDelete:
+			// Deletes the primary PDP context. This will shut down the Nif.
+			return DeleteContext(aOption);
+
+		case KContextActivate:
+			// If the IPv4 interface is up, then the context will already have
+			// been activated. So this command should fail with 
+			// KErrAlreadyExists
+			{
+			TUint8* ptr = CONST_CAST(TUint8*, aOption.Ptr()); 
+			TContextParameters* contextParams =
+				REINTERPRET_CAST(TContextParameters*, ptr);
+
+			if (contextParams->iContextInfo.iContextId != 
+				STATIC_CAST(TInt8, GetNifMain().GetBcaController()->Nsapi()))
+				{
+				contextParams->iReasonCode = KErrNotFound;
+				}
+			else
+				{
+				contextParams->iContextInfo.iStatus =
+					GetNifMain().GetContextStatus();
+				contextParams->iReasonCode = KErrAlreadyExists;
+				}
+			return KErrNone;
+			}
+
+		case KNifSetDefaultQoS:
+		case KContextQoSSet:
+			// Setting the QoS is meaningless over GPRS, so we just return that
+			// we don't support these operations.
+			break;
+
+		case KContextTFTModify:
+			// As we only have one primary context, we don't support anything
+			// to do with traffic flow templates, which are used by secondary
+			// contexts.
+			break;
+
+		case KContextModifyActive:
+			// This command is only valid aftermodifying TFT/QoS parameters. 
+			// As we don't support any of these operations,
+			// this command is never valid.
+			break;
+#endif
+		default:
+			break;
+			}
+		}
+	return KErrNotSupported;
+	}
+
+TInt CIPv4ProtocolIf::WriteIfConfig(TDes8& aIfConfig)
+/**
+ * Writes the configuration of the interface (eg. IP address, DNS servers)
+ * into the supplied descriptor.
+ *
+ * @param aIfConfig Will contain the interface configuration
+ * @return KErrNotSupported if an incorrect structure is passed, 
+ * otherwise KErrNone
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::WriteIfConfig"));
+
+	if (aIfConfig.Length() != sizeof(TSoInetIfConfig))
+		{
+		return KErrArgument;
+		}
+
+	TUint8* ptr = CONST_CAST(TUint8*, aIfConfig.Ptr());
+	TSoInetIfConfig* config = REINTERPRET_CAST(TSoInetIfConfig*, ptr);
+
+	if (config->iFamily != KAfInet)
+		{
+		return KErrNotSupported;
+		}
+
+	TInetAddr::Cast(config->iConfig.iAddress).SetAddress(iSettings.iLocalAddr);
+	TInetAddr::Cast(config->iConfig.iNetMask).SetAddress(iSettings.iNetMask);
+	TInetAddr::Cast(config->iConfig.iBrdAddr).
+		SetAddress(iSettings.iBroadcastAddr);
+	TInetAddr::Cast(config->iConfig.iDefGate).SetAddress(iSettings.iDefGateway);
+	TInetAddr::Cast(config->iConfig.iNameSer1).
+		SetAddress(iSettings.iPrimaryDns);
+	TInetAddr::Cast(config->iConfig.iNameSer2).
+		SetAddress(iSettings.iSecondaryDns);
+
+	return KErrNone;
+	}
+
+TInt CIPv4ProtocolIf::WriteIfInfo(TDes8& aIfInfo)
+/**
+ * Writes information about the interface into the supplied descriptor.
+ *
+ * @param aIfInfo Will contain the interface information
+ * @return KErrArgument if an incorrect structure is passed, otherwise KErrNone
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::WriteIfInfo"));
+
+	if (aIfInfo.Length() != sizeof(TSoIfInfo))
+		{
+		return KErrArgument;
+		}
+
+	TSoIfInfo* info = (TSoIfInfo*) aIfInfo.Ptr();
+	info->iFeatures = KIfCanBroadcast | KIfCanMulticast;
+	info->iSpeedMetric = iSpeedMetric;
+	info->iMtu = KDefaultMtu;
+	WriteIfName(info->iName);
+
+	return KErrNone;
+	}
+
+TInt CIPv4ProtocolIf::WriteConnectionInfo(TDes8& aConnectionInfo)
+/**
+ * Writes information about the IAP and network we're associated with. This
+ * is used to route data in a multi-homing environment.
+ *
+ * @param aConnectionInfo Will contain the connection information
+ * @return Standard CommDB error codes
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::WriteConnectionInfo"));
+
+	TSoIfConnectionInfo* connectionInfo =
+		(TSoIfConnectionInfo*) aConnectionInfo.Ptr();
+
+	TInt err;
+	// Append the 2 commdb filed into this descriptor
+	TBuf<2*KCommsDbSvrMaxColumnNameLength+1> fieldName;
+
+	fieldName.Copy(TPtrC(IAP));
+	fieldName.Append(KSlashChar);
+	fieldName.Append(TPtrC(COMMDB_ID));
+	err = GetNifMain().GetAgent()->ReadInt(fieldName, connectionInfo->iIAPId);
+	if (err != KErrNone)
+		{
+		return err;
+		}
+
+	fieldName.Copy(TPtrC(IAP));
+	fieldName.Append(KSlashChar);
+	fieldName.Append(TPtrC(IAP_NETWORK));
+	err = GetNifMain().GetAgent()->ReadInt(fieldName, connectionInfo->iNetworkId);
+	if (err != KErrNone)
+		{
+		return err;
+		}
+
+	return KErrNone;
+	}
+#ifdef WCDMA_STUB
+
+TInt CIPv4ProtocolIf::DeleteContext(TDes8& aContextParameters)
+/**
+ * Deletes a context. As the NIF is responsible for one primary context,
+ * this is equivalent to closing down the NIF.
+ *
+ * @param aContextParameters Parameters of the context to delete
+ * @return KErrArgument if an incorrect structure is passed, otherwise KErrNone
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::DeleteContext"));
+
+	if (aContextParameters.Length() != sizeof(TContextParameters))
+		{
+		return KErrArgument;
+		}
+
+	TUint8* ptr = CONST_CAST(TUint8*, aContextParameters.Ptr());
+	TContextParameters* params = REINTERPRET_CAST(TContextParameters*, ptr);
+
+	if (params->iContextInfo.iContextId != 
+		STATIC_CAST(TInt8, GetNifMain().GetBcaController()->Nsapi()))
+		{
+		params->iReasonCode = KErrBadName;
+		}
+	else
+		{
+		params->iReasonCode = KErrNone; 
+		GetNifMain().Stop(KErrNone, MNifIfNotify::EDisconnect);
+		}
+
+	return KErrNone;
+	}
+
+#endif
+
+void CIPv4ProtocolIf::ReadCommDbGprsSettingsL()
+/**
+ * Reads GPRS IP settings from CommDB via the agent.
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::ReadCommDbGprsSettings"));
+
+	// Read the IP address settings from CommDB.
+	ReadIPv4SettingL(TPtrC(GPRS_IP_ADDR), iSettings.iLocalAddr);
+	ReadIPv4SettingL(TPtrC(GPRS_IP_NETMASK), iSettings.iNetMask);
+	ReadIPv4SettingL(TPtrC(GPRS_IP_NAME_SERVER1), iSettings.iPrimaryDns);
+	ReadIPv4SettingL(TPtrC(GPRS_IP_NAME_SERVER2), iSettings.iSecondaryDns);
+	ReadIPv4SettingL(TPtrC(GPRS_IP_GATEWAY), iSettings.iDefGateway);
+
+	// Read whether to get the gateway IP address from the server.
+	_BTT_LEAVEIFERROR(GetNifMain().GetAgent()->ReadBool(
+		TPtrC(GPRS_IP_ADDR_FROM_SERVER),
+		iSettings.iGetGatewayFromServer));
+
+	// Read whether to get the DNS addresses from the server.
+	_BTT_LEAVEIFERROR(GetNifMain().GetAgent()->ReadBool(
+		TPtrC(GPRS_IP_DNS_ADDR_FROM_SERVER),
+		iSettings.iGetDnsFromServer));
+
+	// Because CommDB doesn't define a Broadcast Address field, we must
+	// calculate the broadcast address. This is based on the localAddr
+	// and the netMask.
+	TInetAddr localAddr(iSettings.iLocalAddr, 0);
+	TInetAddr netMask(iSettings.iNetMask, 0);
+	TInetAddr broadcast;
+	broadcast.SubNetBroadcast(localAddr, netMask);
+	iSettings.iBroadcastAddr = broadcast.Address();
+	}
+
+void CIPv4ProtocolIf::UpdateContextConfigL(const
+										  RPacketContext::TContextConfigGPRS&
+										  aConfig)
+/**
+ * Called when the context has been activated to set our IP address and get
+ * any other required settings from CommDB.
+ *
+ * @param aConfig The new context config
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::UpdateContextConfig"));
+
+	// Get the settings which are stored in CommDB.
+	ReadCommDbGprsSettingsL();
+
+	// Get our IP address from the GPRS context config.
+	TInetAddr address;
+	
+	TBuf<RPacketContext::KMaxPDPAddressLength> tempAddr;
+	tempAddr.Copy(aConfig.iPdpAddress);
+	TInt ret = address.Input(tempAddr);
+
+	// We've got our IP address! Let's save it.
+	if (ret == KErrNone)
+		{
+		iSettings.iLocalAddr = address.Address();
+		LOG_IP_ADDRESS("Got local IP address", iSettings.iLocalAddr);
+		}
+	else
+		{
+		_LOG_L2C2(_L8("Couldn't get IP address from GPRS config (err: %d)"),
+			ret);
+
+		// Don't leave on this error: we may still be OK if we read some
+		// settings from CommDB.
+		}
+
+	// @todo - is this correct. We can only get the DNS addresses
+	// from the TSY using the iProtocolConfigOption data. Yet a client could
+	// access those DNS config details without knowing about the state of the
+	// iSettings.iGetDnsFromServer flag.
+
+	if ((iSettings.iGetDnsFromServer) ||
+		((iSettings.iPrimaryDns == 0) &&
+		 (iSettings.iSecondaryDns == 0)) ) 
+		{
+		TBuf<RPacketContext::KMaxPDPAddressLength> tempAddr;
+		tempAddr.Copy(aConfig.iProtocolConfigOption.iDnsAddresses.iPrimaryDns);
+		ret = address.Input(tempAddr);
+
+		if (ret == KErrNone)
+			{
+			iSettings.iPrimaryDns = address.Address();
+			LOG_IP_ADDRESS("Got primary DNS", iSettings.iPrimaryDns);
+			}
+		else
+			{
+			_LOG_L2C2(_L8("Couldn't get primary DNS address from GPRS config (err: %d)"),
+				ret);
+
+			// Don't leave on this error: we may still be OK if we read some
+			// settings from CommDB.
+			}
+
+		tempAddr.Copy(aConfig.iProtocolConfigOption.iDnsAddresses.iSecondaryDns);
+		ret = address.Input(tempAddr);
+
+		if (ret == KErrNone)
+			{
+			iSettings.iSecondaryDns = address.Address();
+			LOG_IP_ADDRESS("Got secondary DNS", iSettings.iPrimaryDns);
+			}
+		else
+			{
+			_LOG_L2C2(_L8("Couldn't get secondary DNS address from GPRS config (err: %d)"),
+				ret);
+
+			// Don't leave on this error: we may still be OK if we read some
+			// settings from CommDB.
+			}
+		}
+	else
+		{
+		LOG_IP_ADDRESS("Using CommDB DNS address - Primary ", iSettings.iPrimaryDns);
+		LOG_IP_ADDRESS("                         - Secondary ", iSettings.iSecondaryDns);
+		}
+
+
+	// TProtocolConfigOptionV2::iMiscBuffer is not the correct way to pass a gateway
+	// address - data needs to be passed in TLV format but there are no TLV content tags
+	// defined for a gateway address and any UMTS/GPRS hardware which claims to be able
+	// to supply this address is erroneous (3gpp standard 24.008, section 10.5.6.3).
+	// This misuse of iMiscBuffer was preventing other correctly formed parameters from
+	// being passed (INC113612).
+/*	if (iSettings.iGetGatewayFromServer)
+		{
+		tempAddr.Copy(aConfig.iProtocolConfigOption.iMiscBuffer);
+		ret = address.Input(tempAddr);
+
+		if (ret == KErrNone)
+			{
+			iSettings.iDefGateway = address.Address();
+			LOG_IP_ADDRESS("Got default gateway", iSettings.iDefGateway);
+			}
+		else
+			{
+			_LOG_L2C2(_L8("Couldn't get default gateway from GPRS config (err: %d)"),
+				ret);
+			}
+		}*/
+	}
+
+void CIPv4ProtocolIf::UpdateConnectionSpeed(TUint aConnectionSpeed)
+/**
+ * Sets the speed metric to return to TCP/IP, based on what the TSY tells us.
+ *
+ * @param aConnectionSpeed Our connection speed
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::UpdateConnectionSpeed"));
+
+	iSpeedMetric = aConnectionSpeed;
+	}
+
+void CIPv4ProtocolIf::ReadIPv4SettingL(const TDesC& aFieldName,
+									   TUint32& aIpAddr)
+/**
+ * Reads an IPv4 address from CommDB, via the TRP agent. It leaves if an error
+ * other than KErrNotFound occurs.
+ *
+ * @param aFieldName The name of the field to read
+ * @param aIpAddr Will contain the IP address
+ */
+	{
+#ifdef __BTT_LOGGING__
+	TBuf8<256> debugBuffer;
+	debugBuffer.Copy(aFieldName);
+	_LOG_L1C2(_L8("CIPv4ProtocolIf::ReadIp4Setting [aFieldName=%S]"),
+		&debugBuffer);
+#endif
+
+	TBuf<KCommsDbSvrMaxFieldLength> name;
+	TInetAddr ip4Addr;
+
+	TInt ret = GetNifMain().GetAgent()->ReadDes(aFieldName, name);
+
+	if (ret == KErrNone)
+		{
+		// We've successfully read an IP address, so convert it into a number.
+		ip4Addr.Input(name);
+		aIpAddr = ip4Addr.Address();
+		}
+	else
+		{
+		// We couldn't get the IP address, so set it to 0.0.0.0. Note that we
+		// only leave here if we got a more serious error than "not found".
+		aIpAddr = 0;
+		if (ret != KErrNotFound)
+			{
+			_BTT_LEAVEIFERROR(ret);
+			}
+		}
+	}
+
+TInt CIPv4ProtocolIf::Send(RMBufChain& aPdu, TAny* aSource)
+/**
+ * Called by the protocol to send an outgoing IP packet to the network.
+ *
+ * @param aPdu The outgoing packet
+ * @param aSource The source of the packet
+ * @return Standard error codes
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::Send"));
+
+#ifdef __BTT_LOGGING__
+	LogPacket(aPdu);
+#endif
+
+	// Return <0: an error occurred
+	// Return  0: no error, but don't send any more packets
+
+	return GetNifMain().SendPacket(aPdu, aSource, KIp4FrameType);
+	}
+
+void CIPv4ProtocolIf::Info(TNifIfInfo& aInfo) const
+/**
+ * Called by the protocol to get information about the NIF.
+ *
+ * @param aInfo Will contain NIF information
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::Info"));
+
+	// The parent class sets everything except the name...
+	CProtocolIfBase::Info(aInfo);
+	// ...which we set here.
+	WriteIfName(aInfo.iName);
+	}
+
+TInt CIPv4ProtocolIf::Notification(TAgentToNifEventType /*aEvent*/, 
+	void* /*aInfo*/)
+/**
+ * The Nif will ignore any notification sent
+ *
+ * @param aEvent Not used
+ * @param aInfo Not used 
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::Notification"));
+
+	return KErrNone;
+	}
+
+void CIPv4ProtocolIf::StartSending(CProtocolBase* aProtocol)
+/**
+ * Indicates to the protocol layer that the NIF is ready to send packets.
+ *
+ * @param aProtocol A pointer to a protocol
+ */
+	{
+	_LOG_L1C2(_L8("CIPv4ProtocolIf::StartSending [aProtocol=%X]"), aProtocol);
+
+	CProtocolIfBase::StartSending(aProtocol);
+	}
+
+TBool CIPv4ProtocolIf::WantsProtocol(TUint16 aProtocolCode)
+/**
+ * Indicates the type of protocol implemented by this class.
+ *
+ * @param aProtocolCode The protocol type
+ */
+	{
+	_LOG_L1C2(_L8("CIPv4ProtocolIf::WantsProtocol [aProtocolCode=%X]"),
+		aProtocolCode);
+
+#ifdef RAWIP_HEADER_APPENDED_TO_PACKETS
+	return ((aProtocolCode & 0x00FF) == KIp4FrameType);
+#else
+	(void) aProtocolCode; // disable compiler warning
+	return ETrue;
+#endif // RAWIP_HEADER_APPENDED_TO_PACKETS
+	}
+
+void CIPv4ProtocolIf::Process(RMBufChain& aPdu)
+/**
+ * Called when an incoming IP packet has arrived. Send packets up to the
+ * TCP/IP stack.
+ *
+ * @param aPdu The incoming packet
+ */
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::Process"));
+
+#ifdef __BTT_LOGGING__
+	LogPacket(aPdu);
+#endif
+
+	// Pass incoming packets up to the protocol, unless it hasn't
+	// been bound yet.
+	if (iProtocol)
+		{
+		_LOG_L1C1(_L8("CIPv4ProtocolIf: Packet Sent to TCP/IP Protocol!!!"));
+		iProtocol->Process(aPdu, reinterpret_cast<CProtocolBase*>(this));
+		}
+	else 
+		{
+		_LOG_L2C1(_L8("WARNING: dumping incoming packet, no protocol bound"));
+		aPdu.Free();
+		}
+	}
+
+#ifdef __BTT_LOGGING__
+void CIPv4ProtocolIf::LogPacket(const RMBufChain& aPacket)
+/**
+* Logs packet information into log file.
+*
+* @param aPacket The packet 
+*/
+	{
+	_LOG_L1C1(_L8("CIPv4ProtocolIf::LogPacket"));
+
+	TInt mBufLength = aPacket.Length() - aPacket.First()->Length();
+
+	_LOG_L3C2(_L8("Analysis of %d byte packet:"), mBufLength);
+
+	//Note: All the constants used on this method are a pragmatic guess of the
+	//IP header fields. The only porpose of this method is logging.
+
+	if (mBufLength < 20)
+		{
+		_LOG_L3C2(_L8(" -doesn't appear to be a valid IPv4 packet (length=%d)")
+			, mBufLength);
+		return;
+		}
+
+	// Get a pointer to the packet's payload.
+	const TUint8* payloadPtr = aPacket.First()->Next()->Ptr();
+
+	if ((payloadPtr[0] & 0xF0) != 0x40)
+		{
+		_LOG_L3C2(_L8(" - doesn't appear to be an IPv4 packet (version=0x%X)"),
+			(payloadPtr[0] & 0xF0) >> 4);
+		return;
+		}
+
+	if ((payloadPtr[0] & 0xF) != 0x5)
+		{
+		_LOG_L3C2(_L8(" - doesn't have a standard IP header (length=0x%X)"),
+			payloadPtr[0] & 0xF);
+		return;
+		}
+
+	_LOG_L3C5(_L8(" - src addr: %d.%d.%d.%d"), payloadPtr[12], payloadPtr[13],
+		payloadPtr[14], payloadPtr[15]);
+	_LOG_L3C5(_L8(" - dst addr: %d.%d.%d.%d"), payloadPtr[16], payloadPtr[17],
+		payloadPtr[18], payloadPtr[19]);
+
+	if (payloadPtr[9] == 0x06)
+		{
+		_LOG_L3C1(_L8(" - appears to be a TCP packet"));
+		if (mBufLength < 40)
+			{
+			_LOG_L3C2(_L8(" - but is too short (length=0x%X)"), mBufLength);
+			return;
+			}
+		_LOG_L3C3(_L8(" - src port: %d, dst port: %d"),
+			(payloadPtr[20] << 8) + payloadPtr[21],
+			(payloadPtr[22] << 8) + payloadPtr[23]);
+		_LOG_L3C3(_L8(" - seq #: 0x%08X, ack #: 0x%08X"),
+			(payloadPtr[24] << 24) + (payloadPtr[25] << 16) +
+			(payloadPtr[26] << 8) + payloadPtr[27],
+			(payloadPtr[28] << 24) + (payloadPtr[29] << 16) +
+			(payloadPtr[30] << 8) + payloadPtr[31]);
+
+		TBuf8<100> flagsSet;
+		flagsSet.Copy(_L8(" - flags set: "));
+
+		// Write description of payload's flags to "flagsSet"
+		if (payloadPtr[33] & 0x01)
+			{
+			flagsSet.Append(_L8("FIN "));
+			}
+		if (payloadPtr[33] & 0x02)
+			{
+			flagsSet.Append(_L8("SYN "));
+			}
+		if (payloadPtr[33] & 0x04)
+			{
+			flagsSet.Append(_L8("RST "));
+			}
+		if (payloadPtr[33] & 0x08)
+			{
+			flagsSet.Append(_L8("PSH "));
+			}
+		if (payloadPtr[33] & 0x10)
+			{
+			flagsSet.Append(_L8("ACK "));
+			}
+		if (payloadPtr[33] & 0x20)
+			{
+			flagsSet.Append(_L8("URG "));
+			}
+		_LOG_L3C1(flagsSet);
+
+		TInt dataOffset = payloadPtr[32] >> 2; // in bytes
+		if ((dataOffset > 0) && (mBufLength > dataOffset + 30))
+			{
+			TBuf8<100> data;
+			data.Copy(_L8(" - data begins: "));
+			for (TInt i = dataOffset + 20; i < dataOffset + 100; i++)
+				{
+				// We skip some bytes at the end of the MBuf, as they're junk.
+				if (i >= (mBufLength - 10))
+					{
+					break;
+					}
+				if (TChar(payloadPtr[i]).IsPrint())
+					{
+					data.Append(TChar(payloadPtr[i]));
+					}
+				else
+					{
+					data.Append(TChar('?'));
+					}
+				}
+			_LOG_L3C1(data);
+			}
+		}
+	else if (payloadPtr[9] == 0x01)
+		{
+		_LOG_L3C1(_L8(" - appears to be an ICMP packet"));
+		if (mBufLength < 24)
+			{
+			_LOG_L3C2(_L8(" - but is too short (length=0x%X)"), mBufLength);
+			return;
+			}
+
+		if (payloadPtr[20] == 0x8)
+			{
+			_LOG_L3C1(_L8(" - is an echo request"));
+			}
+		else if (payloadPtr[20] == 0x0)
+			{
+			_LOG_L3C1(_L8(" - is an echo reply"));
+			}
+		else
+			{
+			_LOG_L3C2(_L8(" - unknown type (0x%02X)"), payloadPtr[20]);
+			return;
+			}
+
+		if (mBufLength >= 28)
+			{
+			_LOG_L3C3(_L8(" - ID: 0x%04X, seq #: 0x%04X"),
+				(payloadPtr[24] << 8) + payloadPtr[25],
+				(payloadPtr[26] << 8) + payloadPtr[27]);
+			}
+		}
+	else if (payloadPtr[9] == 0x11)
+		{
+		_LOG_L3C1(_L8(" - appears to be a UDP packet"));
+		if (mBufLength < 28)
+			{
+			_LOG_L3C2(_L8(" - but is too short (length=0x%X)"), mBufLength);
+			return;
+			}
+		_LOG_L3C3(_L8(" - src port: %d, dst port: %d"),
+			(payloadPtr[20] << 8) + payloadPtr[21],
+			(payloadPtr[22] << 8) + payloadPtr[23]);
+		}
+	else
+		{
+		_LOG_L3C2(_L8(" - appears to be for an unknown protocol (0x%X)"),
+			payloadPtr[9]);
+		}
+	}
+#endif // __BTT_LOGGING__