Alters certain defaulted parameters for an extended open (openx) subroutine.
struct dlc_open_ext
{
ulong_t maxsaps;
int (*rcvi_fa)();
int (*rcvx_fa)();
int (*rcvd_fa)();
int (*rcvn_fa)();
int (*excp_fa)();
};
An extended open or openx subroutine can be issued to alter certain defaulted parameters, such as maximum service access points (SAPs) and ring queue depths. Kernel users may change these normally defaulted parameters, but are required to provide additional parameters to notify the dlcopen routine that these callers are to be treated as kernel processes and not as application processes. Additional parameters passed include functional addresses that generic data link control (GDLC) calls to notify about asynchronous events, such as receive data available.
The maxsaps parameter is optional for both the application and the kernel user. The other five parameters are mandatory for kernel users but are ignored by GDLC for application users. There are no default values. Each field must be filled in by the kernel user. All functional entry addresses must be valid. That is, entry points that the kernel user does not wish to support must at least point to a routine which frees the communication's memory buffer (mbuf) passed on the call.
See the /usr/include/sys/gdlextcb.h file for more details on GDLC structures.
| maxsaps | Specifies the maximum number of SAPs the user channel uses to start and run concurrently. Any value from 1 to 127 can be specified. If the default value of 1 is desired, the user must set the field to 0 (zero) before issuing the open subroutine. |
| rcvi_fa | Points to the address of a user I-Frame Data Received routine that handles the sequenced receive data completions. This field is valid for kernel users only and must be set to 0 (zero) by application users. |
| rcvx_fa | Points to the address of a user XID Data Received routine that handles the exchange ID receive data completions. |
| rcvd_fa | Points to the address of a user Datagram Data Received routine that handles the datagram receive data completions. |
| rcvn_fa | Points to the address of a user Network Data Received routine that handles the network receive data completions. |
| excp_fa | Points to the address of a user Exception Condition routine that handles the exception conditions, such as DLC_SAPE_RES (SAP-enabled) or DLC_CONT_RES (LS-contacted). |
These DLC extended parameters for the open subroutine are part of the data link control in BOS Extensions 2 for the device manager you are using.
The open or openx subroutine.
The dlcopen entry point.
List of Kernel Routines for DLC.
Parameter Blocks by ioctl Operation for DLC .
Generic Data Link Control (GDLC) Environment Overview in AIX Version 4.3 Communications Programming Concepts.