Packet Buffer
[Framework]

For background & high-level information on what the active packet buffer is see The Active Packet Buffer. More...

Collaboration diagram for Packet Buffer:


Data Structures
struct	fip_packet_t
	Hold the current active packet. More...
Modules
	IPv6 Specific Packet Handling
	ICMPv6 Specific Packet Handling
Files
file	fip_packet.c
	Active Packet Interface.
Defines
#define	fip_packet_getFromIP6Hdr_isSrcMulticast() (*(fip_packet_getIPBufPtr() + 8) == 0xFF)
	Optimised function to check for IPv6 Multicast in source address.
#define	fip_packet_getFromIP6Hdr_isDestMulticast() (*(fip_packet_getIPBufPtr() + 24) == 0xFF)
	Optimized function to check for IPv6 Multicast in dest address.
#define	fip_packet_getFromIP6Hdr_isDestLinkLocal() (*(fip_packet_getIPBufPtr() + 24) == 0xFE)
#define	fip_packet_getBufPtr(bufNum) (fip_packet_get().buf[bufNum].ptr)
	Get a pointer to a specific buffer, such as the L2 buffer, IP buffer, etc.
#define	fip_packet_getBufMaxSize(bufNum) (fip_packet_get().buf[bufNum].allocSize)
	Get the allocated (maximum) size of a buffer.
#define	fip_packet_getBufSize(bufNum) (fip_packet_get().buf[bufNum].usedSize)
	Get the size of data currently written into the buffer.
#define	fip_packet_setBufSize(bufNum, size) (fip_packet_get().buf[bufNum].usedSize = size)
	Set the size of data currently written into the buffer.
#define	fip_packet_getAttr(attr) fip_packet_get().attr
	Get the value of an attribute from the active packet buffer.
#define	fip_packet_setAttr(attr, value) fip_packet_get().attr = (value)
	Set the value of an attribute to the active packet buffer.
#define	fip_packet_setLLSrcAddr(addr, len)
	Set the LL source address, you must have set the srcLLAddrOffset attribute before calling this!
#define	fip_packet_setLLDestAddr(addr, len)
	Set the LL dest address, you must have set the destLLAddrOffset attribute before calling this!
#define	fip_packet_setAddrFlags(type, flag, value) (fip_packet_get().type.flag = value)
	Set the address flags.
#define	fip_packet_getAddrFlags(type, flag) fip_packet_get().type.flag
	Get the address flags.
#define	fip_packet_spGetPtr(type) ((type *)(fip_packet_get().scratchPad))
	Get a pointer to the 'scratchpad', and cast it to a pointer of the type passed.
#define	fip_packet_getFromBuf_Uint8Unaligned(offset, bufNum)
#define	fip_packet_getIfNum() fip_packet_getAttr(IFNum)
	Get the interface number, available as a separate macro as single-interface systems can replace this with a constant.
Enumerations
enum	fip_packetstate_t { PS_UNUSED, PS_EMPTY, PS_RECEIVINGLL, PS_PROCESSIP, PS_WAITING_AR, PS_SEND, PS_IPFRAG, PS_STARTLLSEND, PS_LLSENDING }
	Valid states the active packet buffer can be in. More...
Functions
fip_return_t	fip_packet_activeNew (fip_bufnum_t bufnum, uint16_t length, fip_ifnum_t ifnum)
	Allocate a new packet & make active.
fip_return_t	fip_packet_ptrBufCpyFromActive (fip_packet_t packetPtr, unsigned int destOffset, uint8_t srcData, unsigned int dataLen)
	Copy srcLen bytes from srcData to the FIP_IPHDRBUF of fragLocation offset from the start, extending the buffer if required to fit the data in.
fip_return_t	fip_packet_activeUnqueuePacket (void)
	If current packet is PS_UNUSED, swap it with something else.
void	fip_packet_activeQueuePacket (void)
	Push the active packet into the queue if supported, if not supported this just frees the packet.
void	fip_packet_activeDrop (void)
	Deallocate the active packet.
fip_return_t	fip_packet_activeResponsePacket (fip_bufnum_t bufnum, unsigned int length)
	Deallocate the current buffer, and allocate a new buffer.
void	fip_packet_activeBufSplit (fip_bufnum_t original, fip_bufnum_t new)
	Takes the specified origin buffer, and splits off all the free space (between allocSize and Size) and moves it to the new buffer, before using this function be SURE allocSize is set correctly in the 'original' buffer, and you don't have free space at the end.
unsigned int	fip_packet_getBufSizes (fip_bufnum_t first, fip_bufnum_t last)
	Returns the total size of all buffers specified, starting at 'first' up to but NOT INCLUDING 'last'.
void	fip_packet_copyToIP6Hdr_destAddr (const uint8_t *const address)
	Copies 16 bytes from the pointer to the IPv6 Destination Address and resets all associated flags containing attributes about the address.
void	fip_packet_copyToIP6Hdr_srcAddr (const uint8_t *const address)
	Copies 16 bytes from the pointer to the IPv6 Source Address and resets all associated flags containing attributes about the address .
void	fip_packet_setToIP6Hdr_srcAddrUnspecified (void)
	Sets the IPv6 Source Address as the Unspecified Address.
void	fip_packet_setToIP6Hdr_destAddrAllNodes (void)
	Sets the IPv6 Destination Address as the All Nodes Address.
void	fip_packet_setToIP6Hdr_destAddrAllRouters (void)
	Sets the IPv6 Destination Address as the All Routers Address.
Variables
uint8_t	fip_activePacket_buffer [FIP_STATIC_BUF_SIZE]
	NB: There are two methods allowed to access the global fip_activePacket structure and directory.

Detailed Description

For background & high-level information on what the active packet buffer is see The Active Packet Buffer.

The active packet could contain a number of different buffers to store information such as Link-Layer Headers, IP Headers, IP Data, UDP Data, etc. The buffers are flexible themselves in that they can be just be statically or dynamically allocated depending on your available resources.

The configuration file will define possible buffers you can use. They must be configured as a number indicating the order in which the packets will be sent, although adding data can occur in any order. Thus you can fill in buffer 0, 3, 2, 4 in that order. When the packet is sent the message will look like [0][2][3][4]. Note buffer 1 had nothing in it, so was omitted from the final message. This configuration allows you to for example define IPv6 Extension Header buffers, and when you need to insert one there is no need to actually move anything, you just insert a pointer to where the extension header is stored.

An example configuration file might look like:

//Link-layer Buffer
#define FIP_LLBUF       0

//IPv6 Header Buffer
#define FIP_IPHDRBUF    1

//IPv6 Hop-By-Hop Buffer
#define FIP_IPHBHBUF    2

//IPv6 Routing Header Buffer
#define FIP_IPRHBUF     3

//IPv6 Additional Header Space
#define FIP_IPAHBUF     4

//Transport Layer Buffer
#define FIP_TLBUF       5

//Application Layer Buffer
#define FIP_APPBUF      6

//Total of 7 buffer types defined (0-6)
#define FIP_NUMBUFS     7

You don't need to use every buffer type you define, but you can't use any type more than once on any packet. If you required multiple of the same type (e.g. for tunnelling, multiple extension headers) you need to define things like FIP_IPHBH1, etc. Each buffer has the following properties:

Ptr A pointer to the buffer

AllocSize The allocated size of the buffer

UsedSize The actual space used in the buffer

In addition the 'link-layer' buffer has additional properties. They are:

srcLLAddrOffset Offset of the source LL Address from start of LL buffer

srcLLAddrLen Length of the source LL address in bytes

destLLAddrOffset Offset of the destination LL Address from start of LL buffer

destLLAddrLen Length of the destination LL address in bytes

Addresses are stored MSB first, if the link-layer provides them another order you are required to flip the addresses around.

Define Documentation

#define fip_packet_getAddrFlags	(	type,
		flag		)	fip_packet_get().type.flag

Get the address flags.

Parameters:

	type	Either 'srcFlags' or 'destFlags'
	flag	See fip_ip6addr_flags_t for flags

Referenced by fip_isDestUnspecified(), fip_isSrcUnspecified(), and fip_nd6_processNS().

#define fip_packet_getAttr ( attr ) fip_packet_get().attr

Get the value of an attribute from the active packet buffer.

Parameters:

attr

The attribute to get. Valid values are elements of the fip_packet_t struct.

Referenced by fip_console(), fip_if6_isDestMyMulticast(), fip_if6_selectSrcAddress(), fip_if6_shortenLLAOLength(), fip_if_newPacketSetup(), fip_ip_process(), fip_ip_send(), fip_nd6_processNS(), fip_packet_activeNew(), fip_packet_activeResponsePacket(), fip_packet_activeUnqueuePacket(), fip_route6_getNextHop(), fip_sixlowpan_llInput(), fip_sixlowpan_process(), and fip_task().

#define fip_packet_getBufMaxSize ( bufNum ) (fip_packet_get().buf[bufNum].allocSize)

Get the allocated (maximum) size of a buffer.

Parameters:

bufNum

Buffer to get the max size of

Referenced by fip_if_newPacketSetup(), fip_ip_process(), and fip_packet_activeBufSplit().

#define fip_packet_getBufPtr ( bufNum ) (fip_packet_get().buf[bufNum].ptr)

Get a pointer to a specific buffer, such as the L2 buffer, IP buffer, etc.

Parameters:

bufNum

Buffer to get a pointer to

Referenced by fip_icmp6_generateEchoRequest(), fip_icmp6_generateError(), fip_icmp6_process(), fip_ip_process(), fip_ipUtils_checksum_tl(), fip_nd6_6lowpan_addRAOptions(), fip_nd6_6lowpan_processNA(), fip_nd6_addLLAO(), fip_nd6_generateNA(), fip_nd6_generateNS(), fip_nd6_generateRA(), fip_nd6_generateRS(), fip_nd6_processLLAO(), fip_nd6_processNA(), fip_nd6_processNS(), fip_nd6_processRA(), fip_nd6_processRS(), fip_packet_activeBufSplit(), fip_sixlowpan_process(), fip_sixlowpanhc_compress(), and fip_udp_sendFinish().

#define fip_packet_getBufSize ( bufNum ) (fip_packet_get().buf[bufNum].usedSize)

Get the size of data currently written into the buffer.

Parameters:

bufNum

Buffer to get size of

Referenced by fip_icmp6_process(), fip_ip_process(), fip_ipUtils_checksum_tl(), fip_nd6_process(), fip_packet_activeBufSplit(), fip_packet_getBufSizes(), fip_sixlowpan_process(), and fip_sixlowpanhc_compress().

#define fip_packet_getFromBuf_Uint8Unaligned	(	offset,
		bufNum		)

Todo:: make this safe

#define fip_packet_getFromIP6Hdr_isDestLinkLocal ( ) (*(fip_packet_getIPBufPtr() + 24) == 0xFE)

Todo:: : technically this includes site-local too

Referenced by fip_if6_selectSrcAddress(), fip_route6_getNextHop(), and fip_route6_process().

#define fip_packet_setAddrFlags	(	type,
		flag,
		value	)	(fip_packet_get().type.flag = value)

Set the address flags.

Parameters:

	type	Either 'srcFlags' or 'destFlags'
	flag	See fip_ip6addr_flags_t for flags
	value	Value to set

Referenced by fip_if6_isDestMyMulticast(), fip_ip_process(), fip_isDestUnspecified(), fip_isSrcUnspecified(), fip_nd6_generateNS(), and fip_packet_setToIP6Hdr_srcAddrUnspecified().

#define fip_packet_setAttr	(	attr,
		value		)	fip_packet_get().attr = (value)

Set the value of an attribute to the active packet buffer.

Parameters:

	attr	The attribute to set. Valid values are elements of the fip_packet_t struct.
	value	The value to set this attribute to.

Referenced by fip_icmp6_finalize(), fip_icmp6_process(), fip_if6_isDestMyUnicast(), fip_if_newPacketSetup(), fip_ip_process(), fip_ip_send(), fip_llgeneric_input(), fip_packet_activeDrop(), fip_packet_activeNew(), fip_packet_activeResponsePacket(), fip_route6_getNextHop(), fip_route6_process(), fip_sixlowpan_llInput(), fip_sixlowpan_process(), fip_task(), and fip_udp_sendFinish().

#define fip_packet_setBufSize	(	bufNum,
		size		)	(fip_packet_get().buf[bufNum].usedSize = size)

Set the size of data currently written into the buffer.

Parameters:

	bufNum	Buffer to get size of
	size	Size of data to write

Referenced by fip_icmp6_generateEchoRequest(), fip_icmp6_generateError(), fip_icmp6_process(), fip_if_newPacketSetup(), fip_ip_process(), fip_llgeneric_input(), fip_nd6_generateNA(), fip_nd6_generateNS(), fip_nd6_generateRA(), fip_nd6_generateRS(), fip_packet_activeBufSplit(), fip_sixlowpan_llInput(), fip_sixlowpanhc_compress(), and fip_udp_sendFinish().

#define fip_packet_setLLDestAddr	(	addr,
		len		)

Value:

{fip_packet_get().destLLAddrLen = len;         \
                                                     memcpy(fip_packet_get().destLLAddrOffset + fip_packet_getBufPtr(FIP_LLBUF), addr, len);}

Set the LL dest address, you must have set the destLLAddrOffset attribute before calling this!

Todo:: PH.4: Improve performance for fixed LL header lengths.

Referenced by fip_ip_send(), fip_llgeneric_input(), fip_nd6_processNS(), fip_nd6_processRS(), fip_route6_getNextHop(), and fip_sixlowpan_llInput().

#define fip_packet_setLLSrcAddr	(	addr,
		len		)

Value:

{fip_packet_get().srcLLAddrLen = len;         \
                                                    memcpy(fip_packet_get().srcLLAddrOffset + fip_packet_getBufPtr(FIP_LLBUF), addr, len);}

Set the LL source address, you must have set the srcLLAddrOffset attribute before calling this!

Todo:: PH.4: Improve performance for fixed LL header lengths.

Referenced by fip_ip_send(), fip_llgeneric_input(), and fip_sixlowpan_llInput().

Enumeration Type Documentation

enum fip_packetstate_t

Valid states the active packet buffer can be in.

Enumerator:

PS_UNUSED	This packet is not allocated.
PS_EMPTY	Packet is allocated, but nothing done with it yet.
PS_RECEIVINGLL	LL is not done receiving data yet.
PS_PROCESSIP	Packet is ready for IP-level processing.
PS_WAITING_AR	Packet's dest IP address is awaiting address resolution to complete.
PS_SEND	Packet is ready to be sent.
PS_IPFRAG	IP Fragmented received/transmit in progress.
PS_STARTLLSEND	Start Link-Layer Transmit.
PS_LLSENDING	Link-Layer Transmit in Progress.

Function Documentation

void fip_packet_activeBufSplit	(	fip_bufnum_t	original,
		fip_bufnum_t	new
	)

Takes the specified origin buffer, and splits off all the free space (between allocSize and Size) and moves it to the new buffer, before using this function be SURE allocSize is set correctly in the 'original' buffer, and you don't have free space at the end.

Parameters:

	original	Buffer to be split
	new	Buffer to split free space into

References fip_packet_getBufMaxSize, fip_packet_getBufPtr, fip_packet_getBufSize, and fip_packet_setBufSize.

Referenced by fip_ip_process().

void fip_packet_activeDrop ( void )

Deallocate the active packet.

Note that calling this when there is no active packet, or the active packet has already been deallocated is safe.

References fip_packet_setAttr, and PS_UNUSED.

Referenced by fip_icmp6_generateError(), fip_icmp6_process(), fip_ip_process(), fip_ip_send(), fip_nd6_6lowpan_processNA(), fip_nd6_generateRA(), fip_nd6_generateRS(), fip_nd6_process(), fip_nd6_processNA(), fip_nd6_processNS(), fip_nd6_processRA(), fip_nd6_processRS(), fip_packet_activeQueuePacket(), fip_packet_activeResponsePacket(), fip_route6_getNextHop(), fip_route6_process(), fip_sixlowpan_process(), and fip_task().

fip_return_t fip_packet_activeNew	(	fip_bufnum_t	bufnum,
		uint16_t	length,
		fip_ifnum_t	ifnum
	)

Allocate a new packet & make active.

Parameters:

	bufnum	The buffer number which you are specifying the length for, any buffer greater than bufnum will have AllocSize of zero, any buffer smaller than bufnum will have the default AllocSize setup at interface intilization for this ifnum
	length	Length of the buffer bufnum to allocate
	ifnum	Interface number to generate packet on

Returns:: fip_return_t indicating status.

References fip_activePacket_buffer, fip_if_newPacketSetup(), fip_packet_activeQueuePacket(), fip_packet_getAttr, fip_packet_setAttr, PS_EMPTY, PS_UNUSED, RV_MEMORY_ERROR, RV_OK, RV_PARAMETER_ERROR, TRACE, TRACE_ADDRET, and TRACE_ADDVARH.

Referenced by fip_icmp6_generateEchoRequest(), fip_llgeneric_input(), fip_nd6_periodicIf(), fip_nd6_periodicUnicast(), fip_nd6_processNS(), fip_packet_activeResponsePacket(), and fip_sixlowpan_llInput().

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fip_return_t fip_packet_activeResponsePacket	(	fip_bufnum_t	bufnum,
		unsigned int	length
	)

Deallocate the current buffer, and allocate a new buffer.

The new buffer takes the source IP address and sets it as the destination.

Parameters:

length

Length of the IP part of the packet to allocate.

Returns:: fip_return_t indicating status.

References fip_ip6addr_t::addr, fip_activePacket_buffer, fip_if_newPacketSetup(), fip_ip6addr_cpy, fip_packet_activeDrop(), fip_packet_activeNew(), fip_packet_getAttr, fip_packet_getFromIP6Hdr_destPtr, fip_packet_getFromIP6Hdr_srcPtr, fip_packet_resetAddrFlags, fip_packet_setAttr, PS_EMPTY, RV_OK, RV_PARAMETER_ERROR, TRACE, TRACE_ADDRET, and TRACE_ADDVARH.

Referenced by fip_icmp6_generateError(), fip_nd6_processNS(), and fip_nd6_processRS().

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void fip_packet_copyToIP6Hdr_destAddr ( const uint8_t *const address )

Copies 16 bytes from the pointer to the IPv6 Destination Address and resets all associated flags containing attributes about the address.

Parameters:

address

Pointer to address to copy from

References fip_packet_getFromIP6Hdr_destPtr, and fip_packet_resetAddrFlags.

Referenced by fip_icmp6_generateEchoRequest(), and fip_nd6_generateNS().

void fip_packet_copyToIP6Hdr_srcAddr ( const uint8_t *const address )

Copies 16 bytes from the pointer to the IPv6 Source Address and resets all associated flags containing attributes about the address .

Parameters:

address

Pointer to address to copy from

References fip_packet_getFromIP6Hdr_srcPtr, and fip_packet_resetAddrFlags.

Referenced by fip_if6_selectSrcAddress(), fip_nd6_generateNS(), fip_nd6_generateRA(), fip_nd6_generateRS(), fip_nd6_periodicUnicast(), and fip_nd6_processNS().

unsigned int fip_packet_getBufSizes	(	fip_bufnum_t	first,
		fip_bufnum_t	last
	)

Returns the total size of all buffers specified, starting at 'first' up to but NOT INCLUDING 'last'.

Parameters:

	first
	last

Returns:

References fip_packet_getBufSize.

Referenced by fip_icmp6_finalize(), fip_ipUtils_checksum_pseudo6hdr(), and fip_sixlowpan_process().

fip_return_t fip_packet_ptrBufCpyFromActive	(	fip_packet_t *	packetPtr,
		unsigned int	destOffset,
		uint8_t *	srcData,
		unsigned int	dataLen
	)

Copy srcLen bytes from srcData to the FIP_IPHDRBUF of fragLocation offset from the start, extending the buffer if required to fit the data in.

Parameters:

	fragLocation	Pointer to the packet to copy to
	destOffset	Offset from the start of the buffer to write the bytes at
	srcData	Source data
	dataLen	Data length to copy

Returns:: A value indicating success (RV_OK) or failure, failure may occur if the destination buffer could not be extended to the required size

References fip_packet_t::buf, RV_MEMORY_ERROR, and RV_OK.

Referenced by fip_ip_process().

Variable Documentation

uint8_t fip_activePacket_buffer[FIP_STATIC_BUF_SIZE]

NB: There are two methods allowed to access the global fip_activePacket structure and directory.

Functions in this file, and macros that start with fip_packet(). You should NEVER access the structure directly, and if you feel compelled to do so it means either you are using something incorrectly, or fip is missing some function. The all-important active packet state.

Referenced by fip_packet_activeNew(), and fip_packet_activeResponsePacket().

Packet Buffer [Framework]

Data Structures

Modules

Files

Defines

Enumerations

Functions

Variables

Detailed Description

Define Documentation

Enumeration Type Documentation

Function Documentation

Variable Documentation

Packet Buffer
[Framework]