iter_hints.h File Reference

This file contains functions to assist the iterator module. More...

#include "util/storage/dnstree.h"
#include "util/locks.h"

Data Structures
struct	iter_hints
	Iterator hints structure. More...
struct	iter_hints_stub
	Iterator hints for a particular stub. More...

Functions
struct iter_hints *	hints_create (void)
	Create hints.
void	hints_delete (struct iter_hints *hints)
	Delete hints.
int	hints_apply_cfg (struct iter_hints *hints, struct config_file *cfg)
	Process hints config.
struct delegpt *	hints_find (struct iter_hints *hints, uint8_t *qname, uint16_t qclass, int nolock)
	Find hints for the given class.
struct delegpt *	hints_find_root (struct iter_hints *hints, uint16_t qclass, int nolock)
	Same as hints_lookup, but for the root only.
int	hints_next_root (struct iter_hints *hints, uint16_t *qclass, int nolock)
	Find next root hints (to cycle through all root hints).
struct iter_hints_stub *	hints_lookup_stub (struct iter_hints *hints, uint8_t *qname, uint16_t qclass, struct delegpt *dp, int nolock)
	Given a qname/qclass combination, and the delegation point from the cache for this qname/qclass, determine if this combination indicates that a stub hint exists and must be primed.
size_t	hints_get_mem (struct iter_hints *hints)
	Get memory in use by hints Locks and unlocks the structure.
int	hints_add_stub (struct iter_hints *hints, uint16_t c, struct delegpt *dp, int noprime, int nolock)
	Add stub to hints structure.
void	hints_delete_stub (struct iter_hints *hints, uint16_t c, uint8_t *nm, int nolock)
	Remove stub from hints structure.
void	hints_swap_tree (struct iter_hints *hints, struct iter_hints *data)
	Swap internal tree with preallocated entries.

Detailed Description

This file contains functions to assist the iterator module.

Keep track of stub and root hints, and read those from config.

Function Documentation

hints_create()

struct iter_hints * hints_create

(

void

)

Create hints.

Returns

new hints or NULL on error.

References iter_hints::lock, and iter_hints::tree.

Referenced by check_hints(), context_finalize(), daemon_fork(), and fr_construct_from_config().

hints_delete()

void hints_delete

(

struct iter_hints *

hints

)

Delete hints.

Parameters

hints

to delete.

References iter_hints::lock.

Referenced by check_hints(), daemon_cleanup(), fr_construct_clear(), and ub_ctx_delete().

hints_apply_cfg()

int hints_apply_cfg	(	struct iter_hints *	hints,
		struct config_file *	cfg
	)

Process hints config.

Sets default values for root hints if no config.

Parameters

hints	where to store.
cfg	config options.

Returns

0 on error.

References compile_time_root_prime(), config_file::do_ip4, config_file::do_ip6, hints_find_root(), hints_insert(), LDNS_RR_CLASS_IN, iter_hints::lock, name_tree_init(), name_tree_init_parents(), read_root_hints_list(), read_stubs(), iter_hints::tree, VERB_ALGO, and verbose().

Referenced by check_hints(), context_finalize(), daemon_fork(), and fr_construct_from_config().

hints_find()

struct delegpt * hints_find	(	struct iter_hints *	hints,
		uint8_t *	qname,
		uint16_t	qclass,
		int	nolock
	)

Find hints for the given class.

The return value is contents of the hints structure. Caller should lock and unlock a readlock on the hints structure if nolock is set. Otherwise caller should unlock the readlock on the hints structure if a value was returned.

Parameters

hints	hint storage.
qname	the qname that generated the delegation point.
qclass	class for which root hints are requested. host order.
nolock	Skip locking, locking is handled by the caller.

Returns

: NULL if no hints, or a ptr to stored hints.

References dname_count_size_labels(), iter_hints_stub::dp, iter_hints::lock, name_tree_find(), and iter_hints::tree.

Referenced by can_have_last_resort(), and hints_find_root().

hints_find_root()

struct delegpt * hints_find_root	(	struct iter_hints *	hints,
		uint16_t	qclass,
		int	nolock
	)

Same as hints_lookup, but for the root only.

Parameters

hints	hint storage.
qclass	class for which root hints are requested. host order.
nolock	Skip locking, locking is handled by the caller.

Returns

: NULL if no hints, or a ptr to stored hints.

References hints_find().

Referenced by hints_apply_cfg(), prime_root(), processInitRequest(), and processLastResort().

hints_next_root()

int hints_next_root	(	struct iter_hints *	hints,
		uint16_t *	qclass,
		int	nolock
	)

Find next root hints (to cycle through all root hints).

Handles its own locking unless nolock is set. In that case the caller should lock and unlock a readlock on the hints structure.

Parameters

hints	hint storage
qclass	class for which root hints are sought. 0 means give the first available root hints class. x means, give class x or a higher class if any. returns the found class in this variable.
nolock	Skip locking, locking is handled by the caller.

Returns

true if a root hint class is found. false if not root hint class is found (qclass may have been changed).

References iter_hints::lock, name_tree_next_root(), and iter_hints::tree.

Referenced by iter_get_next_root().

hints_lookup_stub()

struct iter_hints_stub * hints_lookup_stub	(	struct iter_hints *	hints,
		uint8_t *	qname,
		uint16_t	qclass,
		struct delegpt *	dp,
		int	nolock
	)

Given a qname/qclass combination, and the delegation point from the cache for this qname/qclass, determine if this combination indicates that a stub hint exists and must be primed.

The return value is contents of the hints structure. Caller should lock and unlock a readlock on the hints structure if nolock is set. Otherwise caller should unlock the readlock on the hints structure if a value was returned.

Parameters

hints	hint storage.
qname	The qname that generated the delegation point.
qclass	The qclass that generated the delegation point.
dp	The cache generated delegation point.
nolock	Skip locking, locking is handled by the caller.

Returns

: A priming delegation point if there is a stub hint that must be primed, otherwise null.

References dname_count_size_labels(), dname_strict_subdomain(), iter_hints_stub::dp, iter_hints::lock, delegpt::name, name_tree_lookup(), delegpt::namelabs, iter_hints_stub::noprime, query_dname_compare(), and iter_hints::tree.

Referenced by iter_stub_fwd_no_cache(), prime_stub(), and processInitRequest2().

hints_get_mem()

size_t hints_get_mem

(

struct iter_hints *

hints

)

Get memory in use by hints Locks and unlocks the structure.

Parameters

hints

hint storage.

Returns

bytes in use

References delegpt_get_mem(), iter_hints_stub::dp, iter_hints::lock, RBTREE_FOR, and iter_hints::tree.

Referenced by fr_printmem(), and worker_mem_report().

hints_add_stub()

int hints_add_stub	(	struct iter_hints *	hints,
		uint16_t	c,
		struct delegpt *	dp,
		int	noprime,
		int	nolock
	)

Add stub to hints structure.

For external use since it recalcs the tree parents. Handles its own locking unless nolock is set. In that case the caller should lock and unlock a writelock on the hints structure.

Parameters

hints	the hints data structure
c	class of zone
dp	delegation point with name and target nameservers for new hints stub. malloced.
noprime	set noprime option to true or false on new hint stub.
nolock	Skip locking, locking is handled by the caller.

Returns

false on failure (out of memory);

References iter_hints_stub::dp, hints_insert(), iter_hints::lock, delegpt::name, name_tree_find(), name_tree_init_parents(), delegpt::namelabs, delegpt::namelen, iter_hints_stub::node, iter_hints_stub::noprime, rbtree_delete(), and iter_hints::tree.

Referenced by do_stub_add().

hints_delete_stub()

void hints_delete_stub	(	struct iter_hints *	hints,
		uint16_t	c,
		uint8_t *	nm,
		int	nolock
	)

Remove stub from hints structure.

For external use since it recalcs the tree parents. Handles its own locking unless nolock is set. In that case the caller should lock and unlock a writelock on the hints structure.

Parameters

hints	the hints data structure
c	class of stub zone
nm	name of stub zone (in uncompressed wireformat).
nolock	Skip locking, locking is handled by the caller.

References dname_count_size_labels(), iter_hints::lock, name_tree_find(), name_tree_init_parents(), iter_hints_stub::node, rbtree_delete(), and iter_hints::tree.

Referenced by do_stub_remove().

hints_swap_tree()

void hints_swap_tree	(	struct iter_hints *	hints,
		struct iter_hints *	data
	)

Swap internal tree with preallocated entries.

Caller should manage the locks.

Parameters

hints	the hints data structure.
data	the data structure used to take elements from. This contains the old elements on return.

References rbtree_type::count, rbtree_type::root, and iter_hints::tree.

Referenced by fr_reload_config().