iter_fwd.h File Reference

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

#include "util/rbtree.h"
#include "util/locks.h"

Data Structures
struct	iter_forwards
	Iterator forward zones structure. More...
struct	iter_forward_zone
	Iterator forward servers for a particular zone. More...

Functions
struct iter_forwards *	forwards_create (void)
	Create forwards. More...
void	forwards_delete (struct iter_forwards *fwd)
	Delete forwards. More...
int	forwards_apply_cfg (struct iter_forwards *fwd, struct config_file *cfg)
	Process forwards config. More...
struct delegpt *	forwards_find (struct iter_forwards *fwd, uint8_t *qname, uint16_t qclass, int nolock)
	Find forward zone exactly by name The return value is contents of the forwards structure. More...
struct delegpt *	forwards_lookup (struct iter_forwards *fwd, uint8_t *qname, uint16_t qclass, int nolock)
	Find forward zone information For this qname/qclass find forward zone information, returns delegation point with server names and addresses, or NULL if no forwarding is needed. More...
struct delegpt *	forwards_lookup_root (struct iter_forwards *fwd, uint16_t qclass, int nolock)
	Same as forwards_lookup, but for the root only. More...
int	forwards_next_root (struct iter_forwards *fwd, uint16_t *qclass, int nolock)
	Find next root item in forwards lookup tree. More...
size_t	forwards_get_mem (struct iter_forwards *fwd)
	Get memory in use by forward storage Locks and unlocks the structure. More...
int	fwd_cmp (const void *k1, const void *k2)
	compare two fwd entries
int	forwards_add_zone (struct iter_forwards *fwd, uint16_t c, struct delegpt *dp, int nolock)
	Add zone to forward structure. More...
void	forwards_delete_zone (struct iter_forwards *fwd, uint16_t c, uint8_t *nm, int nolock)
	Remove zone from forward structure. More...
int	forwards_add_stub_hole (struct iter_forwards *fwd, uint16_t c, uint8_t *nm, int nolock)
	Add stub hole (empty entry in forward table, that makes resolution skip a forward-zone because the stub zone should override the forward zone). More...
void	forwards_delete_stub_hole (struct iter_forwards *fwd, uint16_t c, uint8_t *nm, int nolock)
	Remove stub hole, if one exists. More...

Detailed Description

This file contains functions to assist the iterator module.

Keep track of forward zones, and read those from config.

Function Documentation

forwards_create()

struct iter_forwards* forwards_create

(

void

)

Create forwards.

Returns

new forwards or NULL on error.

References iter_forwards::lock.

Referenced by check_fwd(), and context_finalize().

forwards_delete()

void forwards_delete

(

struct iter_forwards *

fwd

)

Delete forwards.

Parameters

fwd	to delete.

References iter_forwards::lock.

Referenced by daemon_cleanup().

forwards_apply_cfg()

int forwards_apply_cfg	(	struct iter_forwards *	fwd,
		struct config_file *	cfg
	)

Process forwards config.

Parameters

fwd	where to store.
cfg	config options.

Returns

0 on error.

References iter_forwards::lock, and iter_forwards::tree.

Referenced by check_fwd(), and context_finalize().

forwards_find()

struct delegpt* forwards_find	(	struct iter_forwards *	fwd,
		uint8_t *	qname,
		uint16_t	qclass,
		int	nolock
	)

Find forward zone exactly by name The return value is contents of the forwards structure.

Caller should lock and unlock a readlock on the forwards structure if nolock is set. Otherwise caller should unlock the readlock on the forwards structure if a value was returned.

Parameters

fwd	forward storage.
qname	The qname of the query.
qclass	The qclass of the query.
nolock	Skip locking, locking is handled by the caller.

Returns

: A delegation point or null.

References iter_forward_zone::dclass, dname_count_size_labels(), iter_forward_zone::dp, rbnode_type::key, iter_forwards::lock, iter_forward_zone::name, iter_forward_zone::namelabs, iter_forward_zone::namelen, iter_forward_zone::node, rbtree_search(), and iter_forwards::tree.

forwards_lookup()

struct delegpt* forwards_lookup	(	struct iter_forwards *	fwd,
		uint8_t *	qname,
		uint16_t	qclass,
		int	nolock
	)

Find forward zone information For this qname/qclass find forward zone information, returns delegation point with server names and addresses, or NULL if no forwarding is needed.

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

Parameters

fwd	forward storage.
qname	The qname of the query.
qclass	The qclass of the query.
nolock	Skip locking, locking is handled by the caller.

Returns

: A delegation point if the query has to be forwarded to that list, otherwise null.

References iter_forward_zone::dclass, dname_count_size_labels(), dname_lab_cmp(), iter_forward_zone::dp, rbnode_type::key, iter_forwards::lock, iter_forward_zone::name, iter_forward_zone::namelabs, iter_forward_zone::namelen, iter_forward_zone::node, iter_forward_zone::parent, rbtree_find_less_equal(), and iter_forwards::tree.

Referenced by forward_request(), forwards_lookup_root(), iter_stub_fwd_no_cache(), and print_root_fwds().

forwards_lookup_root()

struct delegpt* forwards_lookup_root	(	struct iter_forwards *	fwd,
		uint16_t	qclass,
		int	nolock
	)

Same as forwards_lookup, but for the root only.

Parameters

fwd	forward storage.
qclass	The qclass of the query.
nolock	Skip locking, locking is handled by the caller.

Returns

: A delegation point if root forward exists, otherwise null.

References forwards_lookup().

forwards_next_root()

int forwards_next_root	(	struct iter_forwards *	fwd,
		uint16_t *	qclass,
		int	nolock
	)

Find next root item in forwards lookup tree.

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

Parameters

fwd	the forward storage
qclass	class to look at next, or higher.
nolock	Skip locking, locking is handled by the caller.

Returns

false if none found, or if true stored in qclass.

References iter_forwards::lock.

Referenced by iter_get_next_root().

forwards_get_mem()

size_t forwards_get_mem

(

struct iter_forwards *

fwd

)

Get memory in use by forward storage Locks and unlocks the structure.

Parameters

fwd	forward storage.

Returns

bytes in use

References delegpt_get_mem(), iter_forward_zone::dp, iter_forwards::lock, iter_forward_zone::namelen, RBTREE_FOR, and iter_forwards::tree.

forwards_add_zone()

int forwards_add_zone	(	struct iter_forwards *	fwd,
		uint16_t	c,
		struct delegpt *	dp,
		int	nolock
	)

Add zone to forward 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 forwards structure.

Parameters

fwd	the forward data structure
c	class of zone
dp	delegation point with name and target nameservers for new forward zone. malloced.
nolock	Skip locking, locking is handled by the caller.

Returns

false on failure (out of memory);

References iter_forwards::lock.

Referenced by do_forward().

forwards_delete_zone()

void forwards_delete_zone	(	struct iter_forwards *	fwd,
		uint16_t	c,
		uint8_t *	nm,
		int	nolock
	)

Remove zone from forward 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 forwards structure.

Parameters

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

References iter_forwards::lock.

Referenced by do_forward().

forwards_add_stub_hole()

int forwards_add_stub_hole	(	struct iter_forwards *	fwd,
		uint16_t	c,
		uint8_t *	nm,
		int	nolock
	)

Add stub hole (empty entry in forward table, that makes resolution skip a forward-zone because the stub zone should override the forward zone).

Does not add one if not necessary. Handles its own locking unless nolock is set. In that case the caller should lock and unlock a writelock on the forwards structure.

Parameters

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

Returns

false on failure (out of memory);

References iter_forwards::lock.

forwards_delete_stub_hole()

void forwards_delete_stub_hole	(	struct iter_forwards *	fwd,
		uint16_t	c,
		uint8_t *	nm,
		int	nolock
	)

Remove stub hole, if one exists.

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

Parameters

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

References iter_forwards::lock.