Network Buffer

Network buffer support. More...

Collaboration diagram for Network Buffer:

Data Structures
struct	_NBDATA
	Data part of a network buffer structure. More...
struct	_NETBUF
	Network buffer structure. More...
Defines
#define	NBAF_REFCNT   0x07
	Reference count mask.
#define	NBAF_UNICAST   0x08
	Unicast address.
#define	NBAF_DATALINK   0x10
	Datalink buffer allocated flag.
#define	NBAF_NETWORK   0x20
	Network buffer allocated flag.
#define	NBAF_TRANSPORT   0x40
	Transport buffer allocated flag.
#define	NBAF_APPLICATION   0x80
	Application buffer allocated flag.
#define	NBAF_ALL   0xf0
	Masks allocated buffer flags flag.
Typedefs
typedef struct _NETBUF	NETBUF
	Network buffer type.
typedef struct _NBDATA	NBDATA
	Network buffer data type.
Functions
NETBUF *	NutNetBufAlloc (NETBUF *nb, uint8_t type, int size)
	Allocate or re-allocate a network buffer part.
NETBUF *	NutNetBufClonePart (NETBUF *nb, uint8_t inserts)
	Create a referencing copy of an existing network buffer structure.
NETBUF *	NutNetBufClone (NETBUF *nb)
	Create a copy of an existing network buffer structure.
void	NutNetBufFree (NETBUF *nb)
	Release a network buffer structure.
int	NutNetBufCollect (NETBUF *nbq, int total)
	Collect linked list of network buffers.

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Detailed Description

Network buffer support.

The network buffer handling is designed to make life easy when it comes to handling ISO-layered communications. By this we're thinking about communications structures that are hierarchically organized.

The idea is that network buffer structures are allocated every time a new packet is either received or ready for sending. The various fields of the network buffer are then handled by matching layers within the appropriate protocol stack.

Linked list of NETBUF structures:

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Define Documentation

#define NBAF_REFCNT   0x07

Reference count mask.

Definition at line 127 of file netbuf.h.

Referenced by NutNetBufClonePart(), and NutNetBufFree().

#define NBAF_UNICAST   0x08

Unicast address.

Definition at line 129 of file netbuf.h.

Referenced by NutIpInput(), NutTcpInput(), and NutUdpInput().

#define NBAF_DATALINK   0x10

Datalink buffer allocated flag.

Definition at line 131 of file netbuf.h.

Referenced by AhdlcRx(), CSNICrx(), NutEtherOutput(), NutNetBufAlloc(), NutNetBufClonePart(), NutNetBufFree(), and NutPppOutput().

#define NBAF_NETWORK   0x20

Network buffer allocated flag.

Definition at line 132 of file netbuf.h.

Referenced by NutArpAllocNetBuf(), NutIpcpOutput(), NutIpOutput(), NutLcpOutput(), NutNetBufAlloc(), NutNetBufClonePart(), NutNetBufFree(), and NutPapOutput().

#define NBAF_TRANSPORT   0x40

Transport buffer allocated flag.

Definition at line 133 of file netbuf.h.

Referenced by NutIcmpReply(), NutIgmpOutput(), NutNetBufAlloc(), NutNetBufClonePart(), NutNetBufFree(), NutTcpOutput(), and NutUdpOutput().

#define NBAF_APPLICATION   0x80

Application buffer allocated flag.

Definition at line 134 of file netbuf.h.

Referenced by IpcpTxConfReq(), LcpTxConfReq(), LcpTxProtRej(), NutIcmpResponse(), NutNetBufAlloc(), NutNetBufClonePart(), NutNetBufCollect(), NutNetBufFree(), NutTcpOutput(), NutUdpSendTo(), and PapTxAuthReq().

#define NBAF_ALL   0xf0

Masks allocated buffer flags flag.

Definition at line 135 of file netbuf.h.

Referenced by NutNetBufClone(), and NutNetBufClonePart().

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Typedef Documentation

typedef struct _NETBUF NETBUF

Network buffer type.

Definition at line 140 of file netbuf.h.

typedef struct _NBDATA NBDATA

Network buffer data type.

Definition at line 145 of file netbuf.h.

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Function Documentation

NETBUF* NutNetBufAlloc	(	NETBUF *	nb,
		uint8_t	type,
		int	size
	)

Allocate or re-allocate a network buffer part.

Parameters:

nb	Points to an existing network buffer structure or NULL, if a new structure should be created. An existing buffer must not be used any further if this function returns a null pointer.
type	Part of the buffer to be allocated. This can be any of the following: NBAF_DATALINK NBAF_NETWORK NBAF_TRANSPORT NBAF_APPLICATION
size	Size of the part to be allocated.

Returns:

Pointer to the allocated network buffer structure. A null pointer is returned if not enough memory is available and the whole structure is released.

Definition at line 173 of file netbuf.c.

References _NETBUF::nb_ap, _NETBUF::nb_dl, _NETBUF::nb_flags, _NETBUF::nb_nw, _NETBUF::nb_tp, NBAF_APPLICATION, NBAF_DATALINK, NBAF_NETWORK, NBAF_TRANSPORT, NUTASSERT, NutHeapAllocClear, NutHeapFree, NutNetBufFree(), _NBDATA::sz, and _NBDATA::vp.

Referenced by AhdlcRx(), CSNICrx(), IpcpTxConfReq(), LcpTxConfReq(), LcpTxProtRej(), NutArpAllocNetBuf(), NutEtherOutput(), NutIcmpReply(), NutIcmpResponse(), NutIgmpOutput(), NutIpcpOutput(), NutIpOutput(), NutLcpOutput(), NutPapOutput(), NutPppOutput(), NutTcpOutput(), NutUdpOutput(), NutUdpSendTo(), and PapTxAuthReq().

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NETBUF* NutNetBufClonePart	(	NETBUF *	nb,
		uint8_t	inserts
	)

Create a referencing copy of an existing network buffer structure.

Parameters:

nb	Points to an existing network buffer structure, previously allocated by NutNetBufAlloc().
type	Part of the buffer to be additionally allocated. This can be any combination of the following flags: NBAF_DATALINK NBAF_NETWORK NBAF_TRANSPORT NBAF_APPLICATION

Returns:

Pointer to a newly allocated copy.

Definition at line 255 of file netbuf.c.

References memcpy(), _NETBUF::nb_ap, _NETBUF::nb_dl, _NETBUF::nb_flags, _NETBUF::nb_nw, _NETBUF::nb_ref, _NETBUF::nb_tp, NBAF_ALL, NBAF_APPLICATION, NBAF_DATALINK, NBAF_NETWORK, NBAF_REFCNT, NBAF_TRANSPORT, NUTASSERT, NutHeapAllocClear, NutNetBufFree(), _NBDATA::sz, and _NBDATA::vp.

Referenced by NutIpOutput(), NutNetBufClone(), and NutTcpOutput().

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NETBUF* NutNetBufClone

(

NETBUF *

nb

)

Create a copy of an existing network buffer structure.

Parameters:

nb	Points to an existing network buffer structure, previously allocated by NutNetBufAlloc().

Returns:

Pointer to a newly allocated copy.

Definition at line 349 of file netbuf.c.

References NBAF_ALL, and NutNetBufClonePart().

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void NutNetBufFree

(

NETBUF *

nb

)

Release a network buffer structure.

Returns all memory previously allocated by a network buffer to the available heap space.

Parameters:

nb	Points to an existing network buffer structure, previously allocated by NutNetBufAlloc().

Definition at line 364 of file netbuf.c.

References _NETBUF::nb_ap, _NETBUF::nb_dl, _NETBUF::nb_flags, _NETBUF::nb_nw, _NETBUF::nb_ref, _NETBUF::nb_tp, NBAF_APPLICATION, NBAF_DATALINK, NBAF_NETWORK, NBAF_REFCNT, NBAF_TRANSPORT, NUTASSERT, NutHeapFree, NutNetBufFree(), and _NBDATA::vp.

Referenced by EmacRxThread(), IpcpRxConfAck(), IpcpRxConfReq(), IpcpRxTermReq(), LcpTxProtRej(), NicRxLanc(), NutArpCacheQuery(), NutArpInput(), NutEtherInput(), NutEtherOutput(), NutIcmpInput(), NutIgmpInput(), NutIpcpInput(), NutIpcpOutput(), NutIpInput(), NutIpOutput(), NutLcpInput(), NutLcpOutput(), NutNetBufAlloc(), NutNetBufClonePart(), NutNetBufCollect(), NutNetBufFree(), NutPapInput(), NutPapOutput(), NutPppInput(), NutPppOutput(), NutTcpDiscardBuffers(), NutTcpInput(), NutTcpOutput(), NutTcpReceive(), NutTcpReject(), NutTcpStateMachine(), NutUdpDestroySocket(), NutUdpInput(), NutUdpReceiveFrom(), and NutUdpSendTo().

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int NutNetBufCollect	(	NETBUF *	nbq,
		int	total
	)

Collect linked list of network buffers.

Parameters:

nbq	Points to an existing network buffer queue.

Returns:

Number of released network buffers.

Definition at line 397 of file netbuf.c.

References memcpy(), _NETBUF::nb_ap, _NETBUF::nb_flags, _NETBUF::nb_next, NBAF_APPLICATION, NutHeapFree, NutNetBufFree(), _NBDATA::sz, and _NBDATA::vp.

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