lapReqCount
#include <AppleTalk.h>
typedef struct ATLAPRec { Size Offset Description short abResult; 2 2 Result code
long abUserReference; 4 4 For your use
LAPAdrBlock lapAddress; 4 8 Destination or source node ID short lapReqCount; 2 12 Length of frame data or buffer
size in bytes
short lapActCount; 2 14 Number of frame data bytes
actually received
Ptr lapDataPtr; 4 16 Pointer to frame data or pointer to buffer
typedef ATLAPRec *ATLAPRecPtr;
typedef ATLAPRec **ATLAPRecHandle;
Notes: When an ALAP frame is sent, the lapAddress field indicates the ID of the
destination node. When an ALAP frame is received, lapAddress returns the
ID of the source node. The lapAddress field also indicates the ALAP protocol
type of the frame.
When an ALAP frame is sent, lapReqCount indicates the size of the frame
data in bytes and lapDataPtr points to a buffer containing the frame data to
be sent. When an ALAP frame is received, the lapDataPtr points to a buffer
in which the incoming data can be stored and lapReqCount indicates the size
of the buffer in bytes. The number of bytes actually sent or received is
returned the the lapActCount field.
Each ALAP frame contains an 8-bit ALAP protocol type in the header. ALAP
protocol types 128 through 255 are reserved for internal use by ALAP,
hence the declaration:
typedef Byte ABByte; ALAP protocol type Warning: Do not use ALAP protocol type values 1 and 2; they're reserved
for use by DDP. Values 3 through 15 are reserved for internal use by Apple
and also should not be used.
Using ALAP
Most programs will never need to call ALAP, because higher- level
protocols will automatically call it as necessary. If you do want to send a
frame directly via ALAP, cal the LAPWrite function. If you want to read ALAP frames, you have two choices:
the node's protocol handler table. The ALAP code will examine every
incoming frame and send all those with the correct ALAP protocol type to
your protocol handler. When your program no longer wants to receive
frames with a particular ALAP protocol type value, it can call
the protocol handler table.