diff -r a579325b79dd -r 1422c6cd3f0c networkprotocols/iphook/inhook6/include/in_pkt_platform.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/networkprotocols/iphook/inhook6/include/in_pkt_platform.h Sat Feb 20 00:22:11 2010 +0200 @@ -0,0 +1,488 @@ +// 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 the License "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: +// in_pkt.h - packet handling routines +// Generic packet handling utility for mapping packet handling to the RMBufChain. +// + + + +/** + @file in_pkt_partner.h + @publishedPartner + @released +*/ + +#ifndef __IN_PKTPARTNER_H__ +#define __IN_PKTPARTNER_H__ + +#include + +// RMBufPacketPeek +// *************** +class RMBufPacketPeek : public RMBufChain + /** + Extends RMBufChain to add functions to read packet data as a descriptor + and as an IP header. + + The RMBufChain is assumed to contain the raw packet, without + the info block prepended (e.g. if this class is used for RMBufPacketBase + derived handle, it must be in "unpacked" state). + + @since v7.0 + @publishedAll + @released + */ + { +public: + IMPORT_C TPtr8 Access(TInt aSize, TUint aOffset = 0); + IMPORT_C TIpHeader *GetIpHeader(); + }; + +// TPacketHead +// *********** +class TPacketHead + /** + Storage for some precomputed information for an outbound packet flow. + + The outbound TPacketHead is part of the flow context (CFlowContext). + + The CFlowContext::Connect initializes the content from the parameters + of the flow (TFlowInfo) and runs the connection process.. The connection + process (MIp6Hook::OpenL and MFlowHook::ReadyL phases) completes the + information. After this, as long as the flow is connected, the content + is mostly frozen and must not be modified by anyone. + + When there is a need to change any flow information, the changes must + be done to the flow parameters (and not to TPacketHead). The change of + flow parameters also sets the CFlowContext::iChanged flag, and this + eventually causes a new CFlowContext::Connect, which re-initializes + the TPacketHead with the new information. + + For each field in the TPacketHead, the hook writer must follow the + basic rule (only for fields that it intends to change): + + - if some field is changed in MIp6Hook::OpenL, then the previous + value should be restored in the MFlowHook::ReadyL. + - an exeception: the hook must omit the restore, if the + previous value was unspecified value (for example, the source + address). + - the content of #iPacket (and #iOffset) are special: they cannot + be modified in the MIp6Hook::OpenL phase. A hook can + modify them only in the MFlowHook::ReadyL phase. And, if the hook + is adding an IP header for tunneling, it must save the current content + of these fields in the ReadyL function, and then clear out the fields + (it must make the iPacket empty and zero iOffset). The hook must add + the saved iPacket content below the added tunnel header in + MFlowHook::ApplyL . + + @since v7.0 + @publishedAll + @released + */ + { +public: + IMPORT_C TBool ExtHdrGet(TInt aType, TInt& aOfs, TInt& aLen); + IMPORT_C TBool ExtHdrGetOrPrependL(TInt aType, TInt& aOfs, TInt& aLen); + IMPORT_C TBool ExtHdrGetOrAppendL(TInt aType, TInt& aOfs, TInt& aLen); + IMPORT_C void AddDestinationOptionL(const TPtrC8& aOption, TUint8 aAlign=0, TUint8 aModulo=4); + IMPORT_C void AddDestinationOptionL(const TUint8* aOption, TUint8 aLen, TUint8 aAlign=0, TUint8 aModulo=4); + +public: + /** + "Virtual" IP header. The IPv6 header stucture is used, but the same + format is also used for the IPv4 destinations (Version() == 4, + even though the header format is still IPv6!) + + This header is initialized in the beginning of the OpenL phase + as follows: + @li Version = 0 + @li Traffic Class, copied from the flow iOptions.iTrafficClass + @li Flow Label = 0 + @li Payload Length = 0 (dummy field, not used) + @li Next Header, copied from the flow iProtocol + @li Hop Limit, copied from the flow iOptions.iHopLimit + @li Src Address, copied from the flow Local Address (usually unspecified) + @li Dst Address, copied from the flow Remote Address + + At beginning of the ReadyL phase (= at end of OpenL), the destination + address (and iDstId) are used to find a route on the interface. Depending + on whether this address is IPv4 (mapped) or IPv6, the Version field is set + accordingly to either 4 or 6. + + After succesfull completion of the ReadyL, this used for *each* packet + which needs an IP header to be generated on send. The Version() determines + whether IPv4 or IPv6 frame is to be generated (this is the initial + header in the packet, *before* running outbound ApplyL hooks): + + @verbatim + IPv6 IPv4 + Version == 6 ==4 + Traffic Class used as is used as TOS + Flow Label used as is ignored + Payload Length ignored ignored + Next Header used as is used as Protocol + Hop Limit used as is used as TTL + Src Address used as is used as IPv4 mapped + Dst Address used as is used as IPv4 mapped + @endverbatim + */ + TInet6HeaderIP ip6; + /** + Contains the scope id associated with the destination address + which is stored in #ip6 Dst Address. This id and address must + always be considered as a unit. Logically, any change changes + both values. + + iDstId is initialized from the flow context TFlowInfo::iRemote.Scope() at + beginning of the flow connect phase. If application does not define + this scope id, then the system will attempt to choose a default value + at beginning of the connect phase. If the default cannot be determined, + the flow is put into pending state (and no connect happens). + + @par MIp6Hook::OpenL + On entry to the OpenL, the iDstId is always non-zero and destination + address is specified. If a hook changes the destination address in + OpenL method, it must provide the correct id value + which goes with the new destination. If it cannot do this, it + must either abort the connect by leaving with an error state, or it + can leave with PENDING (> 0) status to signal there is no route + for the new destination. + If the stack cannot find suitable interface for the destination, then + it aborts the connect phase, and the flow is placed into holding state. + + @note + Only a tunneling hook can safely change the destination + address (a use of routing header can also be a kind of + tunneling). + + @par MFlowHook::ReadyL + If the hook changed the destination address (or id) in the OpenL, + the ReadyL must restore the original values back. + + */ + TUint32 iDstId; + /** + Contains the scope id associated with the source address + which is stored in #ip6 Src address. This is defined when the source + address is defined, and otherwise undefined. + + iSrcId is initialized from TFlowInfo::iLocal.Scope() at beginning of the + flow connect phase. If application defines the source address, + but does not specify this scope id, then the system chooses + the id based on the interface defined by the source address. + If scope and address are both specified, they must match the + selected interface. + + @par MIp6Hook::OpenL + On entry to the OpenL, the iSrcId (and source address) may be + undefined (#iSourceSet = 0). If defined (iSourceSet = 1), then + both address and iSrcId are defined (iSrcId != 0). A hook may + force a reselection of the source just by zeroing the + iSourceSet. + + @par MFlowHook::ReadyL + If the hook changed the source address (or id) in the OpenL, + the ReadyL must restore the original values back, but only + if the original value was defined (#iSourceSet = 1 in OpenL). + */ + TUint32 iSrcId; + /** + The source address has been set. + + This bit indicates whether the value stored in #ip6 src field + and #iSrcId is to be used as a source address as is. + + Initialized from TFlowInfo::iLocalSet, which tells whether user + specified tbe source address or not (e.g used RSocket Bind method). + The stack checks the value after each MIp6Hook::OpenL call, and + if the flag is set, the source in ip6 is used as is. If the flag + is zero, then the stack performs the normal source address selection + based on the current destination address (#iSrcId and destination + address). + + @par MIp6Hook::OpenL + On entry, this flag is always set and source address is defined. + A hook may clear this flag, if it wants the + stack choose the source address based on current destination. + The clearing operation is normally needed only by a tunneling + hook. + + @note + If the hook specifies the source address, it must be either + a valid source address for the interface or unspecified + address. + + @par MFlowHook::ReadyL + Upon entry to the ReadyL, the source address is always fully + known (the hook can assume that #iSrcId and the #ip6 source + addresses are valid). + If the source address was set before the OpenL, then this + must restore the original value (along with the #iSrcId + and source address). + */ + TUint iSourceSet:1; +#ifdef TPACKETHEAD_FRAGMENT + /** + The fragment processing alredy done. + + This bit is meaningful only in OpenL phase. If already set, + then some ealier hook has requested that the packet must + be fragmented to fit the mtu. + + A tunneling hook can set this bit in OpenL, if it needs + the fragmenting to happen before the ApplyL is called (e.g. + the fragments are tunneled instead of fragmenting the + tunneling). + + This bit can only be set or left as is. It cannot be cleared + once set. + */ + TUint iFragment:1; +#endif + /** + Selector info, the upper layer protocol. + + iProtocol has the same value as ip6.NextHeader() when iPacket is empty, + and otherwise it is the same as NextHeader() of the last extension + header in the iPacket. + + The values of the other selector fields: #iIcmpType, #iIcmpCode + #iSrcPort and #iDstPort depend on iProtocol. Whenever iProtocol + is changed, the other fields must be updated accordingly. + + @par MIp6Hook::OpenL + Because iPacket cannot be modified during the OpenL phase, the + content of this field and the Next Header (protocol) field in + the #ip6 pseudoheader must always be the same. This field should + be considered as read-only, unless the hook intends to + apply IP-in-IP tunneling, in which case the hook must + change the value to the appropriate tunneling protocol + (#KProtocolInet6Ipip or #KProtocolInetIpip). + + @par MFlowHook::ReadyL + Only a tunneling hook needs to restore the value here to match + the original upper layer protocol. See #iPacket for + more detailed information. + */ + TUint8 iProtocol; + /** + Selector field whose value depends on #iProtocol. + + If this field does not have meaning with the protocol, + the field content should be set to ZERO. + */ + TUint8 iIcmpType; + /** + Selector field whose value depends on #iProtocol. + + If this field does not have meaning with the protocol, + the field content should be set to ZERO. + */ + TUint8 iIcmpCode; + /** + Selector field whose value depends on #iProtocol. + + If this field does not have meaning with the protocol, + the field content should be set to ZERO. + */ + TUint16 iSrcPort; + /** + Selector field whose value depends on #iProtocol. + + If this field does not have meaning with the protocol, + the field content should be set to ZERO. + */ + TUint16 iDstPort; + /** + The amount of pre-computed IPv6 extension headers in iPacket which + are copied to the beginning of each outgoing packet + + If iOffset > 0, then #iPacket includes that much of extension + headers that are copied in front of each packet. + */ + TInt iOffset; + /** + Pre-computed extension headers for all packets in this flow. + + These can only be added in the ReadyL phase. If any of the + ReadyL's adds extension headers into this, it must take care + of maintaining the correct Next Header in the virtual IP header + (and the original upper layer protocol must be placed in the + next header of the last extension header added. + + Stack copies the content of this to each outgoing packet, just below + the IP header, before running the ApplyL functions of the outbound + flow hooks. + + @par MIp6Hook::OpenL + The iPacket must not be modified during the OpenL phase. + + @par MFlowHook::ReadyL + A non-tunneling hook may add extension headers into the current + iPacket. A tunneling hook has more complex requirements: + it must save the current iPacket and #iOffset and initialize + iOffset = 0, and iPacket as empty. + + @par MFlowHook::ApplyL + When a tunneling hook adds the tunneling IP header, it + must also copy the saved iPacket below the added IP header. + */ + RMBufPacketPeek iPacket; + /** + The received packet which caused an ICMP error reply to be sent. + + This is only used for ICMP error repply flows, and should be + ignored by others -- mainly for IPSEC hook. The packet, if + present, is in unpacked state. + */ + RMBufPacketBase iIcmp; + /** + The current destination interface. + + This is ONLY used during connect/OpenL phase. + + The value is maintained by the stack, and is intended as + read-only information for the hooks that have a use for + it (for example, IPSEC implementing VPN specific policies). + + A hook must not modify this value (the stack will recompute + the value after each OpenL, based on the possibly changed + address parameters in the TPacketHead) + + @par MIp6Hook::OpenL + read-only + @par MFlowHook::ReadyL + read-only + */ + TUint32 iInterfaceIndex; + }; + +// TPacketPoker +// ************ +class TPacketPoker + /** + Provides a utility for linear scanning of a chain of RMBuf objects (an RMBufChain). + + An object of this type maintains a current point in the RMBufChain. This point + can only move forward, and a leave occurs if the point advances beyond the + end of the chain. + + Any pointers and aligns arranged before the current point, remain valid: for + example, you can save a reference and advance the pointer, and the reference + remains usable. + + If instead you need to go to a single specified offset, then use + RMBufChain::Goto() or RMBufPacketPeek::Access(). + + @post + A Generic implementation assert: + after construct, iTail == 0 iff iCurrent == 0 (all scanned), or + in other words: as long as there are bytes after current point, + iTail will be non-zero (and More() returns ETrue). + All methods maintain this invariant or leave, if impossible. + + Some other utility methods, not directly related to scanning, are also included. + @since v7.0 + @publishedAll + @released + */ + { +public: + IMPORT_C TPacketPoker(RMBufChain &aChain); + + inline void SkipL(TInt aSize) + /** + Moves the current point forward a specified number of bytes. + + @param aSize Number of bytes to move forward + @leave KErrEof + if the request cannot be satisfied. + */ + { if (aSize < iTail) { iTail -= aSize; iOffset += aSize; } else OverL(aSize); } + + inline TUint8 *Ptr() const + /** + Raw pointer to the current point (can be invalid, if iTail = 0). + + @note Internal "unsafe" method + */ + {return iCurrent->Ptr() + iOffset; } + + inline TUint8 *ReferenceL(TInt aSize = 1) + /** + Gets a pointer to the current point, such that + at least the specified minimum number of bytes can be read. + + @param aSize + Specified minimum number of bytes to be read through + the returned pointer. + @return Raw data pointer + @leave KErrEof + if the request cannot be satisfied. + */ + { if (iTail >= aSize) return Ptr(); else return AdjustL(aSize); } + + inline TUint8 *ReferenceAndSkipL(TInt aSize) + /** + Gets a pointer to the current point, such that at least the + specified minimum number of bytes can be read, + and moves the point the specified number of bytes forward. + + @param aSize + Specified minimum number of bytes to be read through the returned + pointer, and the number of bytes to move forward + @return + Raw data pointer + @leave KErrEof + if the request cannot be satisfied. + */ + { TUint8 *x = ReferenceL(aSize); SkipL(aSize); return x; } + + inline TInt Remainder() const + /** + Gets the length of the contiguous space after the current point. + + @return Length after the current point + */ + { return iTail; } + + inline TBool AtBegin() const + /** + Tests whether the current point is at the beginning of an RMBuf. + + @return ETrue if current point is at the beginning + */ + { return iOffset == 0; } + + inline TBool More() const + /** + Tests whether there is more data to scan. + + @return ETrue if there is more data to scan + */ + { return iTail > 0; } + + IMPORT_C static TBool IsExtensionHeader(TInt aProtocolId); +private: + IMPORT_C void OverL(TInt aSize); + IMPORT_C TUint8 *AdjustL(TInt aSize); + /** The RMBuf of the current point. */ + RMBuf *iCurrent; + /** The offset of the current point in the RMBuf. */ + TInt iOffset; + /** Remaining bytes starting from the current point in the RMBuf. */ + TInt iTail; + }; + +#endif