BSP Developer's Guide

VxWorks 5.5
BSP Developer’s Guide
srcAddrOffset
Offset into mBlk structure at which the source address starts.
srcSize
Size of source address.
ctrlAddrOffset
Reserved for future use.
ctrlSize
Reserved for future use.
pktType
Type of packet. For a list of valid packet types, see RFC 1700.
dataOffset
Offset into mBlk structure at which the packet data starts.
Tracking Data That Passes Between the Driver and the Protocol: mBlk
Use mBlk structures as a vehicle for passing packets between the driver and
protocol layers. The mBlk structure is defined in netBufLib.h as follows:
typedef struct mBlk
{
M_BLK_HDR mBlkHdr; /* header */
M_PKT_HDR mBlkPktHdr; /* pkthdr */
CL_BLK * pClBlk; /* pointer to cluster blk */
} M_BLK;
mBlkHdr
Contains a pointer to an mHdr structure. For the most part, you should have
no need to access or set this member directly and can treat it as opaque. The
only exception is when you must chain this mBlk to another. In that case, you
need to set the value of mBlk.mHdr.mNext or mBlk.mBlkHdr.mNextPkt or
both. Use mBlk.mBlkHdr.mNext to point to the next mBlk in a chain of
mBlks. Use mBlk.mHdr.mNextPkt to point to an mBlk that contains the head
of the next packet.
mBlkPktHdr
Contains a pointer to an pktHdr structure. You should have no need to access
or set this member directly and can treat it as opaque.
pClBlk
Contains a pointer to an clBlk structure. You should have no need to access or
set this member directly and can treat it as opaque. However, if you are not
288