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

104 Chapter3
NetIPC Intrinsics
IPCRECV
X.25 Considerations
In receiving a response to a connection request, the option field returns
the facility field and the call user data (CUD) field. With fast select, up
to 128 bytes of call user data may be returned in the call user data
receive buffer (
opt 5).
A single IPCRECV call returns data for one message only. If the “more
data” flag is set, the complete message has not been received. The
remaining part of the message can be received by subsequent calls to
IPCRECV, unless the destroy flag (29) is set.
If the destroy flag is set, the remaining part of the message is
destroyed. The end of message is indicated by the “more data” flag not
being set.
If an interrupt packet is received in the middle of a data packet stream,
IPCRECV returns no data. The
result parameter indicates that an
interrupt event has occurred. The interrupt user data field can be
retrieved by calling IPCCONTROL, request 12 (reason for error or event).
The next call to IPCRECV returns the whole data message.
If a reset packet is received in the middle of a data packet stream, all
previously received packets are discarded. IPCRECV returns no data.
The
result parameter indicates a reset has occurred. Use the
IPCCONTROL request 12 (reason for error or event) to retrieve the cause
and diagnostic fields for the reset.
Common errors returned by IPCRECV in
result are:
SOCKERR 0 Request complete successfully.
SOCKERR 59 Socket timeout.
SOCKERR 65 Connection aborted by local protocol module.
SOCKERR 67 Connection failure detected.
SOCKERR 107 Transport is going down.
SOCKERR 117 Attempt to establish connection failed.
SOCKERR 146 Reset event occurred on X.25 connection.
SOCKERR 156 Interrupt event occurred on X.25
connection.
SOCKERR 158 Connection request rejected by remote.
A complete table of SOCKERRs is include in Appendix C ,
“Error Messages.”
TCP
The urgent data bit indicates that urgent data has been received. Table
3-8 demonstrates the meaning of urgent data and more data. Use these
bits in combination to determine the status of data received.