A generic callback mechanism
[The Net-SNMP library]

マクロ定義
#define	CALLBACK_NAME_LOGGING   1
#define	LOCK_PER_CALLBACK_SUBID   1
#define	CALLBACK_LOCK(maj, min)   ++_locks[major][minor]
#define	CALLBACK_UNLOCK(maj, min)   --_locks[major][minor]
#define	CALLBACK_LOCK_COUNT(maj, min)   _locks[major][minor]
関数
NETSNMP_STATIC_INLINE int	_callback_lock (int major, int minor, const char *warn, int assert)
NETSNMP_STATIC_INLINE void	_callback_unlock (int major, int minor)
void	init_callbacks (void)
int	snmp_register_callback (int major, int minor, SNMPCallback *new_callback, void *arg)
	This function registers a generic callback function.
int	netsnmp_register_callback (int major, int minor, SNMPCallback *new_callback, void *arg, int priority)
int	snmp_call_callbacks (int major, int minor, void *caller_arg)
	This function calls the callback function for each registered callback of type major and minor.
int	snmp_count_callbacks (int major, int minor)
int	snmp_callback_available (int major, int minor)
int	snmp_unregister_callback (int major, int minor, SNMPCallback *target, void *arg, int matchargs)
	This function unregisters a specified callback function given a major and minor type.
int	netsnmp_callback_clear_client_arg (void *ptr, int i, int j)
	find and clear client args that match ptr
void	clear_callback (void)
snmp_gen_callback *	snmp_callback_list (int major, int minor)

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関数

int netsnmp_callback_clear_client_arg	(	void *	ptr,
		int	i,
		int	j
	)

find and clear client args that match ptr

引数:

	ptr	pointer to search for
	i	callback id to start at
	j	callback subid to start at

callback.c の 462 行で定義されています。

参照先 snmp_gen_callback::next・NULL・snmp_gen_callback::sc_callback・snmp_gen_callback::sc_client_arg.

参照元 clear_callback().

int snmp_call_callbacks	(	int	major,
		int	minor,
		void *	caller_arg
	)

This function calls the callback function for each registered callback of type major and minor.

引数:

	major	is the SNMP callback major type used
	minor	is the SNMP callback minor type used
	caller_arg	is a void pointer which is sent in as the callback's serverarg parameter, if needed.

戻り値:

Returns SNMPERR_GENERR if major is >= MAX_CALLBACK_IDS or minor is >= MAX_CALLBACK_SUBIDS, otherwise SNMPERR_SUCCESS is returned.

参照:

snmp_register_callback

snmp_unregister_callback

callback.c の 286 行で定義されています。

参照先 _callback_lock()・_callback_unlock()・init_callbacks()・snmp_gen_callback::next・NULL・snmp_gen_callback::sc_callback・snmp_gen_callback::sc_client_arg.

参照元 add_trap_session()・check_access()・in_a_view()・log_handler_callback()・netsnmp_acm_check_subtree()・netsnmp_register_mib()・netsnmp_register_mib_table_row()・read_configs()・read_premib_configs()・snmp_shutdown()・snmp_store()・unregister_mibs_by_session().

int snmp_register_callback	(	int	major,
		int	minor,
		SNMPCallback *	new_callback,
		void *	arg
	)

This function registers a generic callback function.

The major and minor values are used to set the new_callback function into a global static multi-dimensional array of type struct snmp_gen_callback. The function makes sure to append this callback function at the end of the link list, snmp_gen_callback->next.

引数:

major

is the SNMP callback major type used SNMP_CALLBACK_LIBRARY

• SNMP_CALLBACK_APPLICATION

引数:

	minor	is the SNMP callback minor type used SNMP_CALLBACK_POST_READ_CONFIG SNMP_CALLBACK_STORE_DATA SNMP_CALLBACK_SHUTDOWN SNMP_CALLBACK_POST_PREMIB_READ_CONFIG SNMP_CALLBACK_LOGGING SNMP_CALLBACK_SESSION_INIT
	new_callback	is the callback function that is registered.
	arg	when not NULL is a void pointer used whenever new_callback function is exercised.

戻り値:

Returns SNMPERR_GENERR if major is >= MAX_CALLBACK_IDS or minor is >= MAX_CALLBACK_SUBIDS or a snmp_gen_callback pointer could not be allocated, otherwise SNMPERR_SUCCESS is returned.

• #define MAX_CALLBACK_IDS 2
• #define MAX_CALLBACK_SUBIDS 16

参照:

snmp_call_callbacks

snmp_unregister_callback

callback.c の 218 行で定義されています。

参照先 netsnmp_register_callback().

参照元 init_snmp_alarm()・netsnmp_init_handler_conf()・netsnmp_register_save_list().

int snmp_unregister_callback	(	int	major,
		int	minor,
		SNMPCallback *	target,
		void *	arg,
		int	matchargs
	)

This function unregisters a specified callback function given a major and minor type.

Note: no bound checking on major and minor.

引数:

	major	is the SNMP callback major type used
	minor	is the SNMP callback minor type used
	target	is the callback function that will be unregistered.
	arg	is a void pointer used for comparison against the registered callback's sc_client_arg variable.
	matchargs	is an integer used to bypass the comparison of arg and the callback's sc_client_arg variable only when matchargs is set to 0.

戻り値:

Returns the number of callbacks that were unregistered.

参照:

snmp_register_callback

snmp_call_callbacks

set cleanup flag?

callback.c の 406 行で定義されています。

参照先 _callback_lock()・_callback_unlock()・CALLBACK_LOCK_COUNT・init_callbacks()・snmp_gen_callback::next・NULL・snmp_gen_callback::sc_callback・snmp_gen_callback::sc_client_arg・SNMP_FREE.

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