NETCONF Server message handler. More...

Collaboration diagram for libyumapro_agt:

Modules
	Agent Profile
	The agent profile is used to store most of the configuration settings.

	Agent Support for YANG Schema Mount

	Agent Utilities
	Contains many general utilities useful for SIL and SIL-SA code to use.

	CLI and .conf File Parameters
	CLI utilities to process the CLI parameters at boot-time.

	Configuration Edit Transactions
	Configuration editing transaction management.

	Constants and Data Types
	Constants and data types used for NETCONF and YANG details.

	Core Agent Functions
	Contains Library entry points and handles init and cleanup.

	Global SIL callbacks
	Global Server callbacks to integrate vendor instrumentation into the YANG module processing.

	Library Mode
	Handle Library mode if it is configured.

	Protocols
	Server Protocol Handlers.

	SIL and SIL-SA Callbacks
	Server callbacks to integrate vendor instrumentation into the YANG module processing.

	Security Features
	YUMA-NACM is obsolete and not supported.

	Sessions
	NCX server sessions allow clients and subsystems to connect to the server.

	Signal Handler
	Processess software interrupts from the operating system.

	yp-system Library
	The optional yp-system library provides system-wide vendor hooks into the server.

Detailed Description

NETCONF Server message handler.

NETCONF PDUs
- PDU instance document parsing
- Object instance syntax validation
- Basic object-level referential integrity
- Value instance document parsing
- Value instance document syntax validation
- Value instance count validation
- Value instance default value insertion

The netconfd server <edit-config> handler registers callbacks with the agt_val module that can be called IN ADDITION to the automated callback, for referential integrity checking, resource reservation, etc.

NCX Write Model

netconfd uses a 3 pass callback model to process <edit-config> PDUs.

Pass 1: Validation : AGT_CB_VALIDATE

The target database is not touched during this phase.

XML parsing
data type validation
pattern and regular expression matching
dynamic instance validation
instance count validation
choice and choice group validation
insertion by default validation
nested 'operation' attribute validation

If any errors occur within a value node (within the /config/ container) then that entire value node is considered unusable and it is not applied.

If continue-on-error is requested, then all sibling nodes will be processed if the validation tests all pass.

Pass 2: Apply : AGT_CB_APPLY

On a per-node granularity, an operation is processed only if no errors occurred during the validation phase.

The target database is modified. User callbacks should not emit external PDUs (e.g., BGP changes) until the COMMIT phase. The automated PDU processing will make non-destructive edits during this phase, even if the 'rollback-on-error' error-option is not requested (in order to simplify the code).

If an error-option other than continue-on-error is requested, then any error returned during this phase will cause further 'apply' phase processing to be terminated.

If error-option is 'stop-on-error' then phase 3 is not executed if this phase terminates with an error.

Pass 3-OK: Commit (Positive Outcome) : AGT_CB_COMMIT

The database edits are automatically completed during this phase. The user callbacks must not edit the database – only modify their own data structures, send PDUs, etc.

Pass 3-ERR: Rollback (Negative Outcome) : AGT_CB_ROLLBACK