Maintain a registry of MIB subtrees, together with related information regarding mibmodule, sessions, etc
[The Net-SNMP agent]

データ構造
struct	lookup_cache_s
struct	lookup_cache_context_s
マクロ定義
#define	IN_SNMP_VARS_C
#define	SUBTREE_DEFAULT_CACHE_SIZE   8
#define	SUBTREE_MAX_CACHE_SIZE   32
型定義
typedef lookup_cache_s	lookup_cache
typedef lookup_cache_context_s	lookup_cache_context
関数
NETSNMP_STATIC_INLINE void	invalidate_lookup_cache (const char *context)
void	netsnmp_set_lookup_cache_size (int newsize)
	set the lookup cache size for optimized agent registration performance.
int	netsnmp_get_lookup_cache_size (void)
	retrieves the current value of the lookup cache size
void	netsnmp_subtree_free (netsnmp_subtree *a)
netsnmp_subtree *	netsnmp_subtree_deepcopy (netsnmp_subtree *a)
subtree_context_cache *	get_top_context_cache (void)
netsnmp_subtree *	netsnmp_subtree_find_first (const char *context_name)
netsnmp_subtree *	add_subtree (netsnmp_subtree *new_tree, const char *context_name)
netsnmp_subtree *	netsnmp_subtree_replace_first (netsnmp_subtree *new_tree, const char *context_name)
NETSNMP_INLINE void	netsnmp_subtree_change_next (netsnmp_subtree *ptr, netsnmp_subtree *thenext)
NETSNMP_INLINE void	netsnmp_subtree_change_prev (netsnmp_subtree *ptr, netsnmp_subtree *theprev)
int	netsnmp_subtree_compare (const netsnmp_subtree *ap, const netsnmp_subtree *bp)
void	netsnmp_subtree_join (netsnmp_subtree *root)
netsnmp_subtree *	netsnmp_subtree_split (netsnmp_subtree *current, oid name[], int name_len)
int	netsnmp_subtree_load (netsnmp_subtree *new_sub, const char *context_name)
int	netsnmp_register_mib (const char *moduleName, struct variable *var, size_t varsize, size_t numvars, oid *mibloc, size_t mibloclen, int priority, int range_subid, oid range_ubound, netsnmp_session *ss, const char *context, int timeout, int flags, netsnmp_handler_registration *reginfo, int perform_callback)
void	register_mib_reattach (void)
void	register_mib_detach (void)
int	register_mib_context (const char *moduleName, struct variable *var, size_t varsize, size_t numvars, oid *mibloc, size_t mibloclen, int priority, int range_subid, oid range_ubound, netsnmp_session *ss, const char *context, int timeout, int flags)
int	register_mib_range (const char *moduleName, struct variable *var, size_t varsize, size_t numvars, oid *mibloc, size_t mibloclen, int priority, int range_subid, oid range_ubound, netsnmp_session *ss)
int	register_mib_priority (const char *moduleName, struct variable *var, size_t varsize, size_t numvars, oid *mibloc, size_t mibloclen, int priority)
int	register_mib (const char *moduleName, struct variable *var, size_t varsize, size_t numvars, oid *mibloc, size_t mibloclen)
void	netsnmp_subtree_unload (netsnmp_subtree *sub, netsnmp_subtree *prev, const char *context)
int	unregister_mib_context (oid *name, size_t len, int priority, int range_subid, oid range_ubound, const char *context)
	Unregisters an OID that has an associated context name value.
int	netsnmp_unregister_mib_table_row (oid *name, size_t len, int priority, int var_subid, oid range_ubound, const char *context)
int	unregister_mib_range (oid *name, size_t len, int priority, int range_subid, oid range_ubound)
int	unregister_mib_priority (oid *name, size_t len, int priority)
int	unregister_mib (oid *name, size_t len)
void	unregister_mibs_by_session (netsnmp_session *ss)
int	in_a_view (oid *name, size_t *namelen, netsnmp_pdu *pdu, int type)
int	check_access (netsnmp_pdu *pdu)
int	netsnmp_acm_check_subtree (netsnmp_pdu *pdu, oid *name, size_t namelen)
	checks to see if everything within a given subtree is either: in view, not in view, or possibly both.
NETSNMP_STATIC_INLINE lookup_cache_context *	get_context_lookup_cache (const char *context)
NETSNMP_STATIC_INLINE void	lookup_cache_add (const char *context, netsnmp_subtree *next, netsnmp_subtree *previous)
NETSNMP_STATIC_INLINE void	lookup_cache_replace (lookup_cache *ptr, netsnmp_subtree *next, netsnmp_subtree *previous)
NETSNMP_STATIC_INLINE lookup_cache *	lookup_cache_find (const char *context, oid *name, size_t name_len, int *retcmp)
netsnmp_subtree *	netsnmp_subtree_find_prev (oid *name, size_t len, netsnmp_subtree *subtree, const char *context_name)
netsnmp_subtree *	netsnmp_subtree_find_next (oid *name, size_t len, netsnmp_subtree *subtree, const char *context_name)
netsnmp_subtree *	netsnmp_subtree_find (oid *name, size_t len, netsnmp_subtree *subtree, const char *context_name)
netsnmp_session *	get_session_for_oid (oid *name, size_t len, const char *context_name)
void	setup_tree (void)
int	remove_tree_entry (oid *name, size_t len)
void	shutdown_tree (void)
void	clear_subtree (netsnmp_subtree *sub)
void	clear_lookup_cache (void)
void	clear_context (void)
void	dump_idx_registry (void)
void	dump_registry (void)
RETSIGTYPE	agent_SIGCHLD_handler (int sig)
int	register_signal (int sig, void(*func)(int))
int	unregister_signal (int sig)
変数
subtree_context_cache *	context_subtrees = NULL
int	lookup_cache_size = 0
int	external_signal_scheduled [NUM_EXTERNAL_SIGS]
void(*[NUM_EXTERNAL_SIGS])	external_signal_handler (int)

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関数

int netsnmp_acm_check_subtree	(	netsnmp_pdu *	pdu,
		oid *	name,
		size_t	namelen
	)

checks to see if everything within a given subtree is either: in view, not in view, or possibly both.

If the entire subtree is not-in-view we can use this information to skip calling the sub-handlers entirely.

戻り値:

0 if entire subtree is accessible, 5 if not and 7 if portions are both. 1 on error (illegal pdu version).

agent_registry.c の 1298 行で定義されています。

参照先 view_parameters::check_subtree・view_parameters::errorcode・snmp_pdu::flags・view_parameters::name・view_parameters::namelen・view_parameters::pdu・snmp_call_callbacks()・snmp_pdu::version.

参照元 netsnmp_add_varbind_to_cache().

int netsnmp_get_lookup_cache_size

(

void

)

retrieves the current value of the lookup cache size

戻り値:

the current lookup cache size

agent_registry.c の 1371 行で定義されています。

参照元 netsnmp_register_mib()・unregister_mib_context().

void netsnmp_set_lookup_cache_size

(

int

newsize

)

set the lookup cache size for optimized agent registration performance.

引数:

newsize

set to the maximum size of a cache for a given context. Set to 0 to completely disable caching, or to -1 to set to the default cache size (8), or to a number of your chosing. The rough guide is that it should be equal to the maximum number of simultanious managers you expect to talk to the agent (M) times 80% (or so, he says randomly) the average number (N) of varbinds you expect to receive in a given request for a manager. ie, M times N. Bigger does NOT necessarily mean better. Certainly 16 should be an upper limit. 32 is the hard coded limit.

agent_registry.c の 1358 行で定義されています。

参照先 SUBTREE_DEFAULT_CACHE_SIZE・SUBTREE_MAX_CACHE_SIZE.

参照元 init_master_agent()・netsnmp_register_mib()・unregister_mib_context().

int unregister_mib_context	(	oid *	name,
		size_t	len,
		int	priority,
		int	range_subid,
		oid	range_ubound,
		const char *	context
	)

Unregisters an OID that has an associated context name value.

Typically used when a module has multiple contexts defined. The parameters priority, range_subid, and range_ubound should be used in conjunction with agentx, see RFC 2741, otherwise these values should always be 0.

引数:

	name	the specific OID to unregister if it conatins the associated context.
	len	the length of the OID, use OID_LENGTH macro.
	priority	a value between 1 and 255, used to achieve a desired configuration when different sessions register identical or overlapping regions. Subagents with no particular knowledge of priority should register with the default value of 127.
	range_subid	permits specifying a range in place of one of a subtree sub-identifiers. When this value is zero, no range is being specified.
	range_ubound	the upper bound of a sub-identifier's range. This field is present only if range_subid is not 0.
	context	a context name that has been created

戻り値:

agent_registry.c の 964 行で定義されています。

参照先 netsnmp_subtree_s::children・netsnmp_get_lookup_cache_size()・netsnmp_oid_equals()・netsnmp_set_lookup_cache_size()・netsnmp_subtree_find()・netsnmp_subtree_find_first()・NULL.

参照元 netsnmp_register_mib()・netsnmp_unregister_handler()・remove_tree_entry()・unregister_mib_range().

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