NetIPC 3000/XL Programmer's Reference Manual (5958-8600)

Chapter 3 101
NetIPC Intrinsics
IPCRECV
opt (input)
Record or byte array, by reference. A list of options,
with associated information. The following options are
defined:
• call user data receive (code 5, len=n; n bytes)
(output). This option provides a buffer for the return
of the call user data (CUD) field if you are using the
fast select facility. If call user data is present, but
this option is not supplied, then the discarded flag
(
flags bit 25) will be set. If the buffer supplied is
not long enough to contain all the data, the data is
truncated and the discarded flag is set. To ensure
receiving all the CUD, this buffer should be at least
128 bytes long.
• data offset (code=8, length=2; 2-byte integer)
(input/output). This option is valid for non-vectored
compatibility mode data only. This option specifies
an offset in bytes from the data parameter’s address.
The received data are to be written into memory
beginning at this location.
• protocol flags (code=144, length=4; 4-byte buffer)
(output). This option contains 32 bits of
protocol-specific flags. The following flags are
currently defined:
— end-to-end acknowledgment (bit 18, output).
(X.25 only.) This flag indicates that the D bit is
set in the X.25 packet associated with this call.
— qualifier bit (bit 19, output). (X.25 only.) This
flag indicates that the Q bit is set in the X.25
packet associated with this call.
— urgent data (bit 27, output). (TCP only.) This
flag indicates that urgent data has been received
on an established connection.
• Facility field (code=145, length=n, n bytes)
(output). (X.25 only). This option provides a buffer
for the return of the facility field. If the buffer is not
long enough to contain all of the data, then the data
is truncated and the discarded flag (bit 25) is set.
This buffer should be at least 109 bytes long to
ensure receipt of the facility field (for more
information, see Chapter 1 , “NetIPC
Fundamentals.”)