badcache.h File Reference

Defines dns_badcache_t, the "bad cache" object. More...

#include <dns/types.h>

Go to the source code of this file.

Defines
#define	DNS_BADCACHE_H   1
Functions
ISC_LANG_BEGINDECLS isc_result_t	dns_badcache_init (isc_mem_t *mctx, unsigned int size, dns_badcache_t **bcp)
void	dns_badcache_destroy (dns_badcache_t **bcp)
	Allocate and initialize a badcache and store it in '*bcp'.
void	dns_badcache_add (dns_badcache_t *bc, dns_name_t *name, dns_rdatatype_t type, isc_boolean_t update, isc_uint32_t flags, isc_time_t *expire)
	Flush and then free badcache in 'bcp'. '*bcp' is set to NULL on return.
isc_boolean_t	dns_badcache_find (dns_badcache_t *bc, dns_name_t *name, dns_rdatatype_t type, isc_uint32_t *flagp, isc_time_t *now)
	Adds a badcache entry to the badcache 'bc' for name 'name' and type 'type'. If an entry already exists, then it will be updated if 'update' is ISC_TRUE. The entry will be stored with flags 'flags' and expiration date 'expire'.
void	dns_badcache_flush (dns_badcache_t *bc)
	Returns ISC_TRUE if a record is found in the badcache 'bc' matching 'name' and 'type', with an expiration date later than 'now'. If 'flagp' is not NULL, then '*flagp' is updated to the flags that were stored in the badcache entry. Returns ISC_FALSE if no matching record is found.
void	dns_badcache_flushname (dns_badcache_t *bc, dns_name_t *name)
	Flush the entire bad cache.
void	dns_badcache_flushtree (dns_badcache_t *bc, dns_name_t *name)
	Flush the bad cache of all entries at 'name'.
void	dns_badcache_print (dns_badcache_t *bc, const char *cachename, FILE *fp)
	Flush the bad cache of all entries at or below 'name'.

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Detailed Description

Defines dns_badcache_t, the "bad cache" object.

Notes:

• A bad cache object is a hash table of name/type tuples, indicating whether a given tuple known to be "bad" in some sense (e.g., queries for that name and type have been returning SERVFAIL). This is used for both the "bad server cache" in the resolver and for the "servfail cache" in the view.

Reliability:

Resources:

Security:

Standards:

Definition in file badcache.h.

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Define Documentation

#define DNS_BADCACHE_H   1

Definition at line 18 of file badcache.h.

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Function Documentation

ISC_LANG_BEGINDECLS isc_result_t dns_badcache_init	(	isc_mem_t *	mctx,
		unsigned int	size,
		dns_badcache_t **	bcp
	)

Definition at line 67 of file badcache.c.

References BADCACHE_MAGIC, cleanup(), dns_badcache::count, DESTROYLOCK, isc_mem_attach(), isc_mem_get, isc_mem_putanddetach, isc_mutex_init, ISC_R_NOMEMORY, ISC_R_SUCCESS, dns_badcache::lock, dns_badcache::magic, dns_badcache::mctx, dns_badcache::minsize, REQUIRE, dns_badcache::size, dns_badcache::sweep, and dns_badcache::table.

Referenced by dns_resolver_create(), and dns_view_create().

void dns_badcache_destroy

(

dns_badcache_t **

bcp

)

Allocate and initialize a badcache and store it in '*bcp'.

Requires:

• mctx != NULL
• bcp != NULL
• *bcp == NULL

Definition at line 108 of file badcache.c.

References DESTROYLOCK, dns_badcache_flush(), isc_mem_put, isc_mem_putanddetach, dns_badcache::lock, dns_badcache::magic, dns_badcache::mctx, REQUIRE, dns_badcache::size, and dns_badcache::table.

Referenced by destroy().

void dns_badcache_add	(	dns_badcache_t *	bc,
		dns_name_t *	name,
		dns_rdatatype_t	type,
		isc_boolean_t	update,
		isc_uint32_t	flags,
		isc_time_t *	expire
	)

Flush and then free badcache in 'bcp'. '*bcp' is set to NULL on return.

Requires:

• '*bcp' to be a valid badcache

Definition at line 161 of file badcache.c.

References badcache_resize(), buffer, cleanup(), dns_badcache::count, dns_name_copy(), dns_name_equal(), dns_name_hash(), dns_name_init(), dns_bcentry::expire, dns_bcentry::flags, dns_bcentry::hashval, isc_buffer_init, ISC_FALSE, isc_mem_get, isc_mem_put, ISC_R_SUCCESS, isc_time_compare(), isc_time_now(), isc_time_settoepoch(), ISC_TRUE, dns_name::length, dns_badcache::lock, LOCK, dns_badcache::mctx, dns_badcache::minsize, dns_bcentry::name, dns_bcentry::next, now, REQUIRE, dns_badcache::size, dns_badcache::table, dns_bcentry::type, UNLOCK, and VALID_BADCACHE.

Referenced by dns_resolver_addbadcache(), and ns_client_error().

isc_boolean_t dns_badcache_find	(	dns_badcache_t *	bc,
		dns_name_t *	name,
		dns_rdatatype_t	type,
		isc_uint32_t *	flagp,
		isc_time_t *	now
	)

Adds a badcache entry to the badcache 'bc' for name 'name' and type 'type'. If an entry already exists, then it will be updated if 'update' is ISC_TRUE. The entry will be stored with flags 'flags' and expiration date 'expire'.

Requires:

• bc to be a valid badcache.
• name != NULL
• expire != NULL

Definition at line 231 of file badcache.c.

References answer, dns_badcache::count, dns_name_equal(), dns_name_hash(), dns_bcentry::expire, dns_bcentry::flags, ISC_FALSE, isc_mem_put, isc_time_compare(), ISC_TRUE, dns_name::length, dns_badcache::lock, LOCK, dns_badcache::mctx, dns_bcentry::name, dns_bcentry::next, REQUIRE, dns_badcache::size, dns_badcache::sweep, dns_badcache::table, dns_bcentry::type, UNLOCK, and VALID_BADCACHE.

Referenced by dns_resolver_getbadcache(), and query_find().

void dns_badcache_flush

(

dns_badcache_t *

bc

)

Returns ISC_TRUE if a record is found in the badcache 'bc' matching 'name' and 'type', with an expiration date later than 'now'. If 'flagp' is not NULL, then '*flagp' is updated to the flags that were stored in the badcache entry. Returns ISC_FALSE if no matching record is found.

Requires:

• bc to be a valid badcache.
• name != NULL
• now != NULL

Definition at line 292 of file badcache.c.

References dns_badcache::count, isc_mem_put, dns_name::length, dns_badcache::mctx, dns_bcentry::name, dns_bcentry::next, REQUIRE, dns_badcache::size, dns_badcache::table, and VALID_BADCACHE.

Referenced by dns_badcache_destroy(), dns_resolver_flushbadcache(), and dns_view_flushcache2().

void dns_badcache_flushname	(	dns_badcache_t *	bc,
		dns_name_t *	name
	)

Flush the entire bad cache.

Requires:

• bc to be a valid badcache

Definition at line 310 of file badcache.c.

References dns_badcache::count, dns_name_equal(), dns_name_hash(), dns_bcentry::expire, ISC_FALSE, isc_mem_put, ISC_R_SUCCESS, isc_time_compare(), isc_time_now(), isc_time_settoepoch(), dns_name::length, dns_badcache::lock, LOCK, dns_badcache::mctx, dns_bcentry::name, dns_bcentry::next, now, REQUIRE, dns_badcache::size, dns_badcache::table, UNLOCK, and VALID_BADCACHE.

Referenced by dns_resolver_flushbadcache(), and dns_view_flushnode().

void dns_badcache_flushtree	(	dns_badcache_t *	bc,
		dns_name_t *	name
	)

Flush the bad cache of all entries at 'name'.

Requires:

• bc to be a valid badcache
• name != NULL

Definition at line 347 of file badcache.c.

References dns_badcache::count, dns_name_issubdomain(), dns_bcentry::expire, isc_mem_put, ISC_R_SUCCESS, isc_time_compare(), isc_time_now(), isc_time_settoepoch(), dns_name::length, dns_badcache::lock, LOCK, dns_badcache::mctx, dns_bcentry::name, dns_bcentry::next, now, REQUIRE, dns_badcache::size, dns_badcache::table, UNLOCK, and VALID_BADCACHE.

Referenced by dns_resolver_flushbadnames(), and dns_view_flushnode().

void dns_badcache_print	(	dns_badcache_t *	bc,
		const char *	cachename,
		FILE *	fp
	)

Flush the bad cache of all entries at or below 'name'.

Requires:

• bc to be a valid badcache
• name != NULL

Definition at line 387 of file badcache.c.

References dns_badcache::count, dns_name_format(), DNS_NAME_FORMATSIZE, dns_rdatatype_format(), DNS_RDATATYPE_FORMATSIZE, dns_bcentry::expire, isc_mem_put, ISC_PLATFORM_QUADFORMAT, isc_time_compare(), isc_time_microdiff(), dns_name::length, dns_badcache::lock, LOCK, dns_badcache::mctx, dns_bcentry::name, namebuf, dns_bcentry::next, now, REQUIRE, dns_badcache::size, dns_badcache::table, TIME_NOW, dns_bcentry::type, UNLOCK, and VALID_BADCACHE.

Referenced by dns_resolver_printbadcache(), dns_view_dumpdbtostream(), and dumpdone().

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