4 NOF Indications

This chapter provides the following information for each NOF indication:

Description of the indication's purpose and usage
Verb control block (VCB) structure, as defined in the NOF API header file /usr/include/sna/nof_c.h
Explanations of the parameters returned to the application in the VCB

For information about how the application registers to receive NOF indications, see REGISTER_INDICATION_SINK.

4.1 CONFIG_INDICATION

This indication is generated when another NOF application or a SNAP-IX administration tool makes a change to the target configuration, when the target node is stopped or started, or when a DLC, port, or LS owned by the target node is stopped or started. The target can be the domain configuration file, a running node, or an inactive node on a server where the SNAP-IX software is running. The target is identified by the target_handle parameter on the REGISTER_INDICATION_SINK verb that registers to receive this indication.

4.1.1 VCB Structure

No specific VCB structure is associated with this indication. To register for configuration indications, the application specifies the value AP_CONFIG_INDICATION as the indication_opcode parameter on REGISTER_INDICATION_SINK. When a change is made, SNAP-IX then reports this to the application's callback routine by sending a copy of the VCB from the NOF verb that made the change. For example, if the configuration was modified by a DEFINE_DLC verb, SNAP-IX sends a copy of the DEFINE_DLC VCB to the application's callback routine.

To enable the application to distinguish between configuration indications and asynchronous responses to its own NOF verbs, SNAP-IX changes the primary_rc parameter in the VCB for a configuration indication. The value AP_INDICATION identifies a VCB associated with a configuration indication; the value AP_OK, or any other value, indicates an asynchronous response to one of the application's own NOF verbs.

The following events are not reported as configuration indications:

Changes to the SNA network file sna.net. To receive indications of these changes, the application must register for the indication type AP_SNA_NET_INDICATION. For more information, see SNA_NET_INDICATION.
Starting and stopping the SNA software on other servers. To receive indications of these changes, the application must register for the indication type AP_SERVER_INDICATION. For more information, see SERVER_INDICATION.

The range of VCBs that can be returned as configuration indications depends on the type of target handle specified on REGISTER_INDICATION_SINK:

Domain configuration file: The application can receive VCBs for any verbs that modify domain resources but not node resources (verbs that can be issued to the domain configuration file).
Node configuration file: The application can receive VCBs for any verbs that modify node resources.
Running node: The application can receive VCBs for any verbs that modify node resources, TERM_NODE VCBs, and START_* and STOP_* VCBs for DLCs, ports, and LSs.
Inactive node: The application can receive VCBs for any verbs that modify node resources and also INIT_NODE VCBs.