resolver.h File Reference

This is the BIND 9 resolver, the module responsible for resolving DNS requests by iteratively querying authoritative servers and following referrals. This is a "full resolver", not to be confused with the stub resolvers most people associate with the word "resolver". The full resolver is part of the caching name server or resolver daemon the stub resolver talks to. More...

#include <isc/lang.h>
#include <isc/socket.h>
#include <dns/types.h>
#include <dns/fixedname.h>

Go to the source code of this file.

Data Structures
struct	dns_fetchevent
	A dns_fetchevent_t is sent when a 'fetch' completes. Any of 'db', 'node', 'rdataset', and 'sigrdataset' may be bound. It is the receiver's responsibility to detach before freeing the event. More...
Defines
#define	DNS_RESOLVER_H   1
#define	DNS_FETCHOPT_TCP   0x001
	Use TCP.
#define	DNS_FETCHOPT_UNSHARED   0x002
	See below.
#define	DNS_FETCHOPT_RECURSIVE   0x004
	Set RD?
#define	DNS_FETCHOPT_NOEDNS0   0x008
	Do not use EDNS.
#define	DNS_FETCHOPT_FORWARDONLY   0x010
	Only use forwarders.
#define	DNS_FETCHOPT_NOVALIDATE   0x020
	Disable validation.
#define	DNS_FETCHOPT_EDNS512   0x040
	Advertise a 512 byte UDP buffer.
#define	DNS_FETCHOPT_WANTNSID   0x080
	Request NSID.
#define	DNS_FETCHOPT_PREFETCH   0x100
	Do prefetch.
#define	DNS_FETCHOPT_NOCDFLAG   0x200
	Don't set CD flag.
#define	DNS_FETCHOPT_NONTA   0x400
	Ignore NTA table.
#define	DNS_FETCHOPT_EDNSVERSIONSET   0x00800000
#define	DNS_FETCHOPT_EDNSVERSIONMASK   0xff000000
#define	DNS_FETCHOPT_EDNSVERSIONSHIFT   24
#define	DNS_RESOLVER_QRYRTTCLASS0   10
#define	DNS_RESOLVER_QRYRTTCLASS0STR   "10"
#define	DNS_RESOLVER_QRYRTTCLASS1   100
#define	DNS_RESOLVER_QRYRTTCLASS1STR   "100"
#define	DNS_RESOLVER_QRYRTTCLASS2   500
#define	DNS_RESOLVER_QRYRTTCLASS2STR   "500"
#define	DNS_RESOLVER_QRYRTTCLASS3   800
#define	DNS_RESOLVER_QRYRTTCLASS3STR   "800"
#define	DNS_RESOLVER_QRYRTTCLASS4   1600
#define	DNS_RESOLVER_QRYRTTCLASS4STR   "1600"
#define	DNS_RESOLVER_CHECKNAMES   0x01
#define	DNS_RESOLVER_CHECKNAMESFAIL   0x02
Typedefs
typedef ISC_LANG_BEGINDECLS struct dns_fetchevent	dns_fetchevent_t
Functions
isc_result_t	dns_resolver_create (dns_view_t *view, isc_taskmgr_t *taskmgr, unsigned int ntasks, unsigned int ndisp, isc_socketmgr_t *socketmgr, isc_timermgr_t *timermgr, unsigned int options, dns_dispatchmgr_t *dispatchmgr, dns_dispatch_t *dispatchv4, dns_dispatch_t *dispatchv6, dns_resolver_t **resp)
	Create a resolver.
void	dns_resolver_freeze (dns_resolver_t *res)
	Freeze resolver.
void	dns_resolver_prime (dns_resolver_t *res)
	Prime resolver.
void	dns_resolver_whenshutdown (dns_resolver_t *res, isc_task_t *task, isc_event_t **eventp)
	Send '*eventp' to 'task' when 'res' has completed shutdown.
void	dns_resolver_shutdown (dns_resolver_t *res)
	Start the shutdown process for 'res'.
void	dns_resolver_attach (dns_resolver_t *source, dns_resolver_t **targetp)
void	dns_resolver_detach (dns_resolver_t **resp)
isc_result_t	dns_resolver_createfetch (dns_resolver_t *res, dns_name_t *name, dns_rdatatype_t type, dns_name_t *domain, dns_rdataset_t *nameservers, dns_forwarders_t *forwarders, unsigned int options, isc_task_t *task, isc_taskaction_t action, void *arg, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset, dns_fetch_t **fetchp)
isc_result_t	dns_resolver_createfetch2 (dns_resolver_t *res, dns_name_t *name, dns_rdatatype_t type, dns_name_t *domain, dns_rdataset_t *nameservers, dns_forwarders_t *forwarders, isc_sockaddr_t *client, isc_uint16_t id, unsigned int options, isc_task_t *task, isc_taskaction_t action, void *arg, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset, dns_fetch_t **fetchp)
isc_result_t	dns_resolver_createfetch3 (dns_resolver_t *res, dns_name_t *name, dns_rdatatype_t type, dns_name_t *domain, dns_rdataset_t *nameservers, dns_forwarders_t *forwarders, isc_sockaddr_t *client, isc_uint16_t id, unsigned int options, unsigned int depth, isc_counter_t *qc, isc_task_t *task, isc_taskaction_t action, void *arg, dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset, dns_fetch_t **fetchp)
	Recurse to answer a question.
void	dns_resolver_cancelfetch (dns_fetch_t *fetch)
	Cancel 'fetch'.
void	dns_resolver_destroyfetch (dns_fetch_t **fetchp)
	Destroy 'fetch'.
void	dns_resolver_logfetch (dns_fetch_t *fetch, isc_log_t *lctx, isc_logcategory_t *category, isc_logmodule_t *module, int level, isc_boolean_t duplicateok)
	Dump a log message on internal state at the completion of given 'fetch'. 'lctx', 'category', 'module', and 'level' are used to write the log message. By default, only one log message is written even if the corresponding fetch context serves multiple clients; if 'duplicateok' is true the suppression is disabled and the message can be written every time this function is called.
dns_dispatchmgr_t *	dns_resolver_dispatchmgr (dns_resolver_t *resolver)
dns_dispatch_t *	dns_resolver_dispatchv4 (dns_resolver_t *resolver)
dns_dispatch_t *	dns_resolver_dispatchv6 (dns_resolver_t *resolver)
isc_socketmgr_t *	dns_resolver_socketmgr (dns_resolver_t *resolver)
isc_taskmgr_t *	dns_resolver_taskmgr (dns_resolver_t *resolver)
isc_uint32_t	dns_resolver_getlamettl (dns_resolver_t *resolver)
	Get the resolver's lame-ttl. zero => no lame processing.
void	dns_resolver_setlamettl (dns_resolver_t *resolver, isc_uint32_t lame_ttl)
	Set the resolver's lame-ttl. zero => no lame processing.
unsigned int	dns_resolver_nrunning (dns_resolver_t *resolver)
	Return the number of currently running resolutions in this resolver. This is may be less than the number of outstanding fetches due to multiple identical fetches, or more than the number of of outstanding fetches due to the fact that resolution can continue even though a fetch has been canceled.
isc_result_t	dns_resolver_addalternate (dns_resolver_t *resolver, isc_sockaddr_t *alt, dns_name_t *name, in_port_t port)
	Add alternate addresses to be tried in the event that the nameservers for a zone are not available in the address families supported by the operating system.
void	dns_resolver_setudpsize (dns_resolver_t *resolver, isc_uint16_t udpsize)
	Set the EDNS UDP buffer size advertised by the server.
isc_uint16_t	dns_resolver_getudpsize (dns_resolver_t *resolver)
	Get the current EDNS UDP buffer size.
void	dns_resolver_reset_algorithms (dns_resolver_t *resolver)
	Clear the disabled DNSSEC algorithms.
void	dns_resolver_reset_ds_digests (dns_resolver_t *resolver)
	Clear the disabled DS/DLV digest types.
isc_result_t	dns_resolver_disable_algorithm (dns_resolver_t *resolver, dns_name_t *name, unsigned int alg)
	Mark the given DNSSEC algorithm as disabled and below 'name'. Valid algorithms are less than 256.
isc_result_t	dns_resolver_disable_ds_digest (dns_resolver_t *resolver, dns_name_t *name, unsigned int digest_type)
	Mark the given DS/DLV digest type as disabled and below 'name'. Valid types are less than 256.
isc_boolean_t	dns_resolver_algorithm_supported (dns_resolver_t *resolver, dns_name_t *name, unsigned int alg)
	Check if the given algorithm is supported by this resolver. This checks whether the algorithm has been disabled via dns_resolver_disable_algorithm(), then checks the underlying crypto libraries if it was not specifically disabled.
isc_boolean_t	dns_resolver_ds_digest_supported (dns_resolver_t *resolver, dns_name_t *name, unsigned int digest_type)
	Check if the given digest type is supported by this resolver. This checks whether the digest type has been disabled via dns_resolver_disable_ds_digest(), then checks the underlying crypto libraries if it was not specifically disabled.
void	dns_resolver_resetmustbesecure (dns_resolver_t *resolver)
isc_result_t	dns_resolver_setmustbesecure (dns_resolver_t *resolver, dns_name_t *name, isc_boolean_t value)
isc_boolean_t	dns_resolver_getmustbesecure (dns_resolver_t *resolver, dns_name_t *name)
void	dns_resolver_settimeout (dns_resolver_t *resolver, unsigned int seconds)
	Set the length of time the resolver will work on a query, in seconds.
unsigned int	dns_resolver_gettimeout (dns_resolver_t *resolver)
	Get the current length of time the resolver will work on a query, in seconds.
void	dns_resolver_setclientsperquery (dns_resolver_t *resolver, isc_uint32_t min, isc_uint32_t max)
void	dns_resolver_getclientsperquery (dns_resolver_t *resolver, isc_uint32_t *cur, isc_uint32_t *min, isc_uint32_t *max)
isc_boolean_t	dns_resolver_getzeronosoattl (dns_resolver_t *resolver)
void	dns_resolver_setzeronosoattl (dns_resolver_t *resolver, isc_boolean_t state)
unsigned int	dns_resolver_getoptions (dns_resolver_t *resolver)
void	dns_resolver_addbadcache (dns_resolver_t *resolver, dns_name_t *name, dns_rdatatype_t type, isc_time_t *expire)
	Add a entry to the bad cache for <name,type> that will expire at 'expire'.
isc_boolean_t	dns_resolver_getbadcache (dns_resolver_t *resolver, dns_name_t *name, dns_rdatatype_t type, isc_time_t *now)
	Check to see if there is a unexpired entry in the bad cache for <name,type>.
void	dns_resolver_flushbadcache (dns_resolver_t *resolver, dns_name_t *name)
	Flush the bad cache of all entries at 'name' if 'name' is non NULL. Flush the entire bad cache if 'name' is NULL.
void	dns_resolver_flushbadnames (dns_resolver_t *resolver, dns_name_t *name)
	Flush the bad cache of all entries at or below 'name'.
void	dns_resolver_printbadcache (dns_resolver_t *resolver, FILE *fp)
void	dns_resolver_setquerydscp4 (dns_resolver_t *resolver, isc_dscp_t dscp)
	Print out the contents of the bad cache to 'fp'.
isc_dscp_t	dns_resolver_getquerydscp4 (dns_resolver_t *resolver)
void	dns_resolver_setquerydscp6 (dns_resolver_t *resolver, isc_dscp_t dscp)
isc_dscp_t	dns_resolver_getquerydscp6 (dns_resolver_t *resolver)
void	dns_resolver_setmaxdepth (dns_resolver_t *resolver, unsigned int maxdepth)
	Get and set the DSCP values for the resolver's IPv4 and IPV6 query sources.
unsigned int	dns_resolver_getmaxdepth (dns_resolver_t *resolver)
void	dns_resolver_setmaxqueries (dns_resolver_t *resolver, unsigned int queries)
	Get and set how many NS indirections will be followed when looking for nameserver addresses.
unsigned int	dns_resolver_getmaxqueries (dns_resolver_t *resolver)

---

Detailed Description

This is the BIND 9 resolver, the module responsible for resolving DNS requests by iteratively querying authoritative servers and following referrals. This is a "full resolver", not to be confused with the stub resolvers most people associate with the word "resolver". The full resolver is part of the caching name server or resolver daemon the stub resolver talks to.

MP:

• The module ensures appropriate synchronization of data structures it creates and manipulates.

Reliability:

• No anticipated impact.

Resources:

• TBS

Security:

• No anticipated impact.

Standards:

• RFCs: 1034, 1035, 2181, TBS
• Drafts: TBS

Definition in file resolver.h.

---

Define Documentation

#define DNS_RESOLVER_H   1

Definition at line 21 of file resolver.h.

#define DNS_FETCHOPT_TCP   0x001

Use TCP.

Definition at line 90 of file resolver.h.

Referenced by fctx_query(), notify_send_toaddr(), resquery_response(), resquery_send(), and start_fetch().

#define DNS_FETCHOPT_UNSHARED   0x002

See below.

Definition at line 91 of file resolver.h.

Referenced by dns_resolver_createfetch3(), fetch_name(), findname(), and resquery_response().

#define DNS_FETCHOPT_RECURSIVE   0x004

Set RD?

Definition at line 92 of file resolver.h.

Referenced by resquery_send().

#define DNS_FETCHOPT_NOEDNS0   0x008

Do not use EDNS.

Definition at line 93 of file resolver.h.

Referenced by fctx_cancelquery(), resquery_response(), and resquery_send().

#define DNS_FETCHOPT_FORWARDONLY   0x010

Only use forwarders.

Definition at line 94 of file resolver.h.

#define DNS_FETCHOPT_NOVALIDATE   0x020

Disable validation.

Definition at line 95 of file resolver.h.

Referenced by cache_name(), fetch_name(), ncache_message(), ns_query_start(), resquery_send(), start_fetch(), and zone_refreshkeys().

#define DNS_FETCHOPT_EDNS512   0x040

Advertise a 512 byte UDP buffer.

Definition at line 96 of file resolver.h.

Referenced by resquery_send().

#define DNS_FETCHOPT_WANTNSID   0x080

Request NSID.

Definition at line 98 of file resolver.h.

Referenced by process_opt(), and resquery_send().

#define DNS_FETCHOPT_PREFETCH   0x100

Do prefetch.

Definition at line 99 of file resolver.h.

Referenced by cache_name(), and query_prefetch().

#define DNS_FETCHOPT_NOCDFLAG   0x200

Don't set CD flag.

Definition at line 100 of file resolver.h.

Referenced by cache_name(), create_fetch(), ncache_message(), resquery_send(), and start_fetch().

#define DNS_FETCHOPT_NONTA   0x400

Ignore NTA table.

Definition at line 101 of file resolver.h.

Referenced by cache_name(), checkbogus(), create_fetch(), ncache_message(), and resquery_send().

#define DNS_FETCHOPT_EDNSVERSIONSET   0x00800000

Definition at line 104 of file resolver.h.

Referenced by resquery_response(), and resquery_send().

#define DNS_FETCHOPT_EDNSVERSIONMASK   0xff000000

Definition at line 105 of file resolver.h.

Referenced by resquery_response(), and resquery_send().

#define DNS_FETCHOPT_EDNSVERSIONSHIFT   24

Definition at line 106 of file resolver.h.

Referenced by resquery_response(), and resquery_send().

#define DNS_RESOLVER_QRYRTTCLASS0   10

Definition at line 112 of file resolver.h.

Referenced by fctx_cancelquery().

#define DNS_RESOLVER_QRYRTTCLASS0STR   "10"

Definition at line 113 of file resolver.h.

Referenced by init_desc().

#define DNS_RESOLVER_QRYRTTCLASS1   100

Definition at line 114 of file resolver.h.

Referenced by fctx_cancelquery().

#define DNS_RESOLVER_QRYRTTCLASS1STR   "100"

Definition at line 115 of file resolver.h.

Referenced by init_desc().

#define DNS_RESOLVER_QRYRTTCLASS2   500

Definition at line 116 of file resolver.h.

Referenced by fctx_cancelquery().

#define DNS_RESOLVER_QRYRTTCLASS2STR   "500"

Definition at line 117 of file resolver.h.

Referenced by init_desc().

#define DNS_RESOLVER_QRYRTTCLASS3   800

Definition at line 118 of file resolver.h.

Referenced by fctx_cancelquery().

#define DNS_RESOLVER_QRYRTTCLASS3STR   "800"

Definition at line 119 of file resolver.h.

Referenced by init_desc().

#define DNS_RESOLVER_QRYRTTCLASS4   1600

Definition at line 120 of file resolver.h.

Referenced by fctx_cancelquery().

#define DNS_RESOLVER_QRYRTTCLASS4STR   "1600"

Definition at line 121 of file resolver.h.

Referenced by init_desc().

#define DNS_RESOLVER_CHECKNAMES   0x01

Definition at line 128 of file resolver.h.

Referenced by configure_view(), and resquery_response().

#define DNS_RESOLVER_CHECKNAMESFAIL   0x02

Definition at line 129 of file resolver.h.

Referenced by cache_name(), and configure_view().

---

Typedef Documentation

typedef ISC_LANG_BEGINDECLS struct dns_fetchevent dns_fetchevent_t

---

Function Documentation

isc_result_t dns_resolver_create	(	dns_view_t *	view,
		isc_taskmgr_t *	taskmgr,
		unsigned int	ntasks,
		unsigned int	ndisp,
		isc_socketmgr_t *	socketmgr,
		isc_timermgr_t *	timermgr,
		unsigned int	options,
		dns_dispatchmgr_t *	dispatchmgr,
		dns_dispatch_t *	dispatchv4,
		dns_dispatch_t *	dispatchv6,
		dns_resolver_t **	resp
	)

Create a resolver.

Notes:

• Generally, applications should not create a resolver directly, but should instead call dns_view_createresolver().

Requires:

• 'view' is a valid view.

• 'taskmgr' is a valid task manager.

• 'ntasks' > 0.

• 'socketmgr' is a valid socket manager.

• 'timermgr' is a valid timer manager.

• 'dispatchv4' is a dispatch with an IPv4 UDP socket, or is NULL. If not NULL, 'ndisp' clones of it will be created by the resolver.

• 'dispatchv6' is a dispatch with an IPv6 UDP socket, or is NULL. If not NULL, 'ndisp' clones of it will be created by the resolver.

• resp != NULL && *resp == NULL.

Returns:

• ISC_R_SUCCESS On success.

• Anything else Failure.

Definition at line 8374 of file resolver.c.

References dns_resolver::buckets, DEFAULT_MAX_QUERIES, DEFAULT_QUERY_TIMEOUT, DEFAULT_RECURSION_DEPTH, DESTROYLOCK, dns_resolver::dispatches4, dns_resolver::dispatches6, dns_resolver::dispatchmgr, dns_badcache_init(), dns_dispatch_getattributes(), DNS_DISPATCHATTR_EXCLUSIVE, dns_dispatchset_create(), dns_dispatchset_destroy(), DNS_RESOLVER_BADCACHESIZE, dns_resstatscounter_buckets, DNS_VIEW_VALID, dns_resolver::exclusivev4, dns_resolver::exclusivev6, dns_resolver::frozen, ISC_FALSE, ISC_LIST_INIT, isc_mem_attach(), isc_mem_create(), isc_mem_detach(), isc_mem_get, isc_mem_put, isc_mem_setname(), isc_mutex_init, ISC_R_NOMEMORY, ISC_R_SUCCESS, isc_rwlock_destroy(), isc_rwlock_init(), isc_stats_set(), isc_task_create(), isc_task_detach(), isc_task_setname(), isc_task_shutdown(), ISC_TF, isc_timer_create(), isc_timer_detach(), isc_timertype_inactive, dns_resolver::lame_ttl, dns_resolver::lock, fctxbucket::lock, dns_resolver::magic, dns_resolver::mctx, dns_view::mctx, dns_resolver::nbuckets, dns_resolver::nlock, dns_resolver::options, dns_resolver::primelock, dns_resolver::querydscp4, dns_resolver::querydscp6, dns_view::rdclass, dns_resolver::rdclass, RECV_BUFFER_SIZE, REQUIRE, RES_MAGIC, dns_view::resstats, RTRACE, dns_resolver::socketmgr, spillattimer_countdown(), fctxbucket::task, dns_resolver::taskmgr, dns_resolver::timermgr, and dns_resolver::view.

Referenced by dns_view_createresolver().

void dns_resolver_freeze

(

dns_resolver_t *

res

)

Freeze resolver.

Notes:

• Certain configuration changes cannot be made after the resolver is frozen. Fetches cannot be created until the resolver is frozen.

Requires:

• 'res' is a valid resolver.

Ensures:

• 'res' is frozen.

Definition at line 8695 of file resolver.c.

References dns_resolver::frozen, ISC_TRUE, REQUIRE, and VALID_RESOLVER.

Referenced by dns_view_freeze().

void dns_resolver_prime

(

dns_resolver_t *

res

)

Prime resolver.

Notes:

• Resolvers which have a forwarding policy other than dns_fwdpolicy_only need to be primed with the root nameservers, otherwise the root nameserver hints data may be used indefinitely. This function requests that the resolver start a priming fetch, if it isn't already priming.

Requires:

• 'res' is a valid, frozen resolver.

Definition at line 8635 of file resolver.c.

References dns_resolver::buckets, dns_rdataset_init(), dns_resolver_createfetch(), dns_rootname, dns_resolver::frozen, INSIST, ISC_FALSE, isc_mem_get, ISC_R_SUCCESS, ISC_TRUE, dns_resolver::lock, LOCK, dns_resolver::mctx, prime_done(), dns_resolver::primelock, REQUIRE, RTRACE, fctxbucket::task, UNLOCK, and VALID_RESOLVER.

Referenced by dns_view_find2().

void dns_resolver_whenshutdown	(	dns_resolver_t *	res,
		isc_task_t *	task,
		isc_event_t **	eventp
	)

Send '*eventp' to 'task' when 'res' has completed shutdown.

Notes:

• It is not safe to detach the last reference to 'res' until shutdown is complete.

Requires:

• 'res' is a valid resolver.

• 'task' is a valid task.

• *eventp is a valid event.

Ensures:

• *eventp == NULL.

Definition at line 8723 of file resolver.c.

References ISC_LIST_APPEND, isc_task_attach(), isc_task_send(), dns_resolver::lock, LOCK, REQUIRE, UNLOCK, and VALID_RESOLVER.

Referenced by dns_view_createresolver().

void dns_resolver_shutdown

(

dns_resolver_t *

res

)

Start the shutdown process for 'res'.

Notes:

• This call has no effect if the resolver is already shutting down.

Requires:

• 'res' is a valid resolver.

Definition at line 8754 of file resolver.c.

References dns_resolver::buckets, dns_resolver::dispatches4, dns_resolver::dispatches6, dns_dispatchset_cancelall(), dns_resolver::exclusivev4, dns_resolver::exclusivev6, fctx_shutdown(), INSIST, ISC_LIST_EMPTY, ISC_LIST_HEAD, ISC_LIST_NEXT, ISC_R_SUCCESS, isc_timer_reset(), isc_timertype_inactive, ISC_TRUE, fctxbucket::lock, dns_resolver::lock, LOCK, dns_resolver::nbuckets, REQUIRE, RTRACE, RUNTIME_CHECK, send_shutdown_events(), fctxbucket::task, UNLOCK, and VALID_RESOLVER.

Referenced by dns_view_createresolver(), and view_flushanddetach().

void dns_resolver_attach	(	dns_resolver_t *	source,
		dns_resolver_t **	targetp
	)

Definition at line 8706 of file resolver.c.

References INSIST, dns_resolver::lock, LOCK, REQUIRE, RRTRACE, UNLOCK, and VALID_RESOLVER.

void dns_resolver_detach

(

dns_resolver_t **

resp

)

Definition at line 8802 of file resolver.c.

References destroy(), INSIST, ISC_FALSE, ISC_TRUE, dns_resolver::lock, LOCK, REQUIRE, RTRACE, UNLOCK, and VALID_RESOLVER.

Referenced by destroy().

isc_result_t dns_resolver_createfetch	(	dns_resolver_t *	res,
		dns_name_t *	name,
		dns_rdatatype_t	type,
		dns_name_t *	domain,
		dns_rdataset_t *	nameservers,
		dns_forwarders_t *	forwarders,
		unsigned int	options,
		isc_task_t *	task,
		isc_taskaction_t	action,
		void *	arg,
		dns_rdataset_t *	rdataset,
		dns_rdataset_t *	sigrdataset,
		dns_fetch_t **	fetchp
	)

Definition at line 8867 of file resolver.c.

References dns_resolver_createfetch3().

Referenced by checkbogus(), create_fetch(), dns_resolver_prime(), resquery_response(), resume_dslookup(), start_fetch(), and zone_refreshkeys().

isc_result_t dns_resolver_createfetch2	(	dns_resolver_t *	res,
		dns_name_t *	name,
		dns_rdatatype_t	type,
		dns_name_t *	domain,
		dns_rdataset_t *	nameservers,
		dns_forwarders_t *	forwarders,
		isc_sockaddr_t *	client,
		isc_uint16_t	id,
		unsigned int	options,
		isc_task_t *	task,
		isc_taskaction_t	action,
		void *	arg,
		dns_rdataset_t *	rdataset,
		dns_rdataset_t *	sigrdataset,
		dns_fetch_t **	fetchp
	)

isc_result_t dns_resolver_createfetch3	(	dns_resolver_t *	res,
		dns_name_t *	name,
		dns_rdatatype_t	type,
		dns_name_t *	domain,
		dns_rdataset_t *	nameservers,
		dns_forwarders_t *	forwarders,
		isc_sockaddr_t *	client,
		isc_uint16_t	id,
		unsigned int	options,
		unsigned int	depth,
		isc_counter_t *	qc,
		isc_task_t *	task,
		isc_taskaction_t	action,
		void *	arg,
		dns_rdataset_t *	rdataset,
		dns_rdataset_t *	sigrdataset,
		dns_fetch_t **	fetchp
	)

Recurse to answer a question.

Notes:

• This call starts a query for 'name', type 'type'.

• The 'domain' is a parent domain of 'name' for which a set of name servers 'nameservers' is known. If no such name server information is available, set 'domain' and 'nameservers' to NULL.

• 'forwarders' is unimplemented, and subject to change when we figure out how selective forwarding will work.

• When the fetch completes (successfully or otherwise), a DNS_EVENT_FETCHDONE event with action 'action' and arg 'arg' will be posted to 'task'.

• The values of 'rdataset' and 'sigrdataset' will be returned in the FETCHDONE event.

• 'client' and 'id' are used for duplicate query detection. '*client' must remain stable until after 'action' has been called or dns_resolver_cancelfetch() is called.

Requires:

• 'res' is a valid resolver that has been frozen.

• 'name' is a valid name.

• 'type' is not a meta type other than ANY.

• 'domain' is a valid name or NULL.

• 'nameservers' is a valid NS rdataset (whose owner name is 'domain') iff. 'domain' is not NULL.

• 'forwarders' is NULL.

• 'client' is a valid sockaddr or NULL.

• 'options' contains valid options.

• 'rdataset' is a valid, disassociated rdataset.

• 'sigrdataset' is NULL, or is a valid, disassociated rdataset.

• fetchp != NULL && *fetchp == NULL.

Returns:

• ISC_R_SUCCESS Success
• DNS_R_DUPLICATE
• DNS_R_DROP

• Many other values are possible, all of which indicate failure.

Referenced by dns_resolver_createfetch(), dns_resolver_createfetch2(), fetch_name(), query_prefetch(), and query_recurse().

void dns_resolver_cancelfetch

(

dns_fetch_t *

fetch

)

Cancel 'fetch'.

Notes:

• If 'fetch' has not completed, post its FETCHDONE event with a result code of ISC_R_CANCELED.

Requires:

• 'fetch' is a valid fetch.

Definition at line 9048 of file resolver.c.

References fetchctx::bucketnum, dns_resolver::buckets, DNS_FETCH_VALID, fetchstate_done, FTRACE, ISC_EVENT_PTR, ISC_LIST_HEAD, ISC_LIST_NEXT, ISC_LIST_UNLINK, ISC_R_CANCELED, isc_task_sendanddetach(), fctxbucket::lock, LOCK, dns_fetch::private, REQUIRE, fetchctx::res, fetchctx::state, UNLOCK, and VALID_FCTX.

Referenced by cancel_fetches_at_name(), checkbogus(), dns_client_cancelresolve(), dns_lookup_cancel(), dns_validator_cancel(), fctx_doshutdown(), ns_query_cancel(), and nta_detach().

void dns_resolver_destroyfetch

(

dns_fetch_t **

fetchp

)

Destroy 'fetch'.

Requires:

• '*fetchp' is a valid fetch.

• The caller has received the FETCHDONE event (either because the fetch completed or because dns_resolver_cancelfetch() was called).

Ensures:

• *fetchp == NULL.

Definition at line 9095 of file resolver.c.

References fetchctx::bucketnum, dns_resolver::buckets, DNS_FETCH_VALID, empty_bucket(), fctx_decreference(), fetchstate_done, FTRACE, ISC_LIST_HEAD, ISC_LIST_NEXT, isc_mem_putanddetach, fctxbucket::lock, LOCK, dns_fetch::mctx, dns_fetch::private, REQUIRE, fetchctx::res, RUNTIME_CHECK, fetchctx::state, UNLOCK, and VALID_FCTX.

Referenced by client_resfind(), dlvfetched(), dns_validator_cancel(), dsfetched(), dsfetched2(), fetch_callback(), fetch_callback_validator(), fetch_done(), keyfetch_done(), lookup_find(), nta_detach(), prefetch_done(), prime_done(), query_resume(), and resume_dslookup().

void dns_resolver_logfetch	(	dns_fetch_t *	fetch,
		isc_log_t *	lctx,
		isc_logcategory_t *	category,
		isc_logmodule_t *	module,
		int	level,
		isc_boolean_t	duplicateok
	)

Dump a log message on internal state at the completion of given 'fetch'. 'lctx', 'category', 'module', and 'level' are used to write the log message. By default, only one log message is written even if the corresponding fetch context serves multiple clients; if 'duplicateok' is true the suppression is disabled and the message can be written every time this function is called.

Requires:

• 'fetch' is a valid fetch, and has completed.

Definition at line 9141 of file resolver.c.

References fetchctx::bucketnum, dns_resolver::buckets, DNS_FETCH_VALID, dns_name_format(), DNS_NAME_FORMATSIZE, fetchctx::info, INSIST, isc_log_write(), ISC_PRINT_QUADFORMAT, isc_result_totext(), ISC_TRUE, fctxbucket::lock, LOCK, dns_fetch::private, REQUIRE, fetchctx::res, UNLOCK, US_PER_SEC, and VALID_FCTX.

Referenced by query_resume().

dns_dispatchmgr_t* dns_resolver_dispatchmgr

(

dns_resolver_t *

resolver

)

Definition at line 9182 of file resolver.c.

References dns_resolver::dispatchmgr, REQUIRE, and VALID_RESOLVER.

Referenced by dns_view_createresolver().

dns_dispatch_t* dns_resolver_dispatchv4

(

dns_resolver_t *

resolver

)

Definition at line 9188 of file resolver.c.

References dns_resolver::dispatches4, dns_dispatchset_get(), REQUIRE, and VALID_RESOLVER.

Referenced by fctx_query().

dns_dispatch_t* dns_resolver_dispatchv6

(

dns_resolver_t *

resolver

)

Definition at line 9194 of file resolver.c.

References dns_resolver::dispatches6, dns_dispatchset_get(), REQUIRE, and VALID_RESOLVER.

Referenced by adjust_interfaces(), and fctx_query().

isc_socketmgr_t* dns_resolver_socketmgr

(

dns_resolver_t *

resolver

)

Definition at line 9200 of file resolver.c.

References REQUIRE, dns_resolver::socketmgr, and VALID_RESOLVER.

isc_taskmgr_t* dns_resolver_taskmgr

(

dns_resolver_t *

resolver

)

Definition at line 9206 of file resolver.c.

References REQUIRE, dns_resolver::taskmgr, and VALID_RESOLVER.

Referenced by dns_view_createresolver().

isc_uint32_t dns_resolver_getlamettl

(

dns_resolver_t *

resolver

)

Get the resolver's lame-ttl. zero => no lame processing.

Requires:

• 'resolver' to be valid.

Definition at line 9212 of file resolver.c.

References dns_resolver::lame_ttl, REQUIRE, and VALID_RESOLVER.

void dns_resolver_setlamettl	(	dns_resolver_t *	resolver,
		isc_uint32_t	lame_ttl
	)

Set the resolver's lame-ttl. zero => no lame processing.

Requires:

• 'resolver' to be valid.

Definition at line 9218 of file resolver.c.

References dns_resolver::lame_ttl, REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

unsigned int dns_resolver_nrunning

(

dns_resolver_t *

resolver

)

Return the number of currently running resolutions in this resolver. This is may be less than the number of outstanding fetches due to multiple identical fetches, or more than the number of of outstanding fetches due to the fact that resolution can continue even though a fetch has been canceled.

Definition at line 9224 of file resolver.c.

References LOCK, dns_resolver::nlock, and UNLOCK.

isc_result_t dns_resolver_addalternate	(	dns_resolver_t *	resolver,
		isc_sockaddr_t *	alt,
		dns_name_t *	name,
		in_port_t	port
	)

Add alternate addresses to be tried in the event that the nameservers for a zone are not available in the address families supported by the operating system.

Require:

• only one of 'name' or 'alt' to be valid.

Definition at line 9233 of file resolver.c.

References alternate::_n, alternate::_u, alternate::addr, dns_name_dup(), dns_name_init(), dns_resolver::frozen, alternate::isaddress, ISC_FALSE, ISC_LINK_INIT, ISC_LIST_APPEND, isc_mem_get, isc_mem_put, ISC_R_NOMEMORY, ISC_R_SUCCESS, ISC_TRUE, dns_resolver::mctx, REQUIRE, and VALID_RESOLVER.

Referenced by configure_alternates().

void dns_resolver_setudpsize	(	dns_resolver_t *	resolver,
		isc_uint16_t	udpsize
	)

Set the EDNS UDP buffer size advertised by the server.

Definition at line 9265 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

isc_uint16_t dns_resolver_getudpsize

(

dns_resolver_t *

resolver

)

Get the current EDNS UDP buffer size.

Definition at line 9271 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

Referenced by ns_client_addopt(), ns_query(), and soa_query().

void dns_resolver_reset_algorithms

(

dns_resolver_t *

resolver

)

Clear the disabled DNSSEC algorithms.

Definition at line 9318 of file resolver.c.

References dns_rbt_destroy(), isc_rwlocktype_write, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by configure_view(), and destroy().

void dns_resolver_reset_ds_digests

(

dns_resolver_t *

resolver

)

Clear the disabled DS/DLV digest types.

Definition at line 9450 of file resolver.c.

References dns_rbt_destroy(), isc_rwlocktype_write, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by configure_view(), and destroy().

isc_result_t dns_resolver_disable_algorithm	(	dns_resolver_t *	resolver,
		dns_name_t *	name,
		unsigned int	alg
	)

Mark the given DNSSEC algorithm as disabled and below 'name'. Valid algorithms are less than 256.

Returns:

• ISC_R_SUCCESS
• ISC_R_RANGE
• ISC_R_NOMEMORY

Definition at line 9333 of file resolver.c.

References algorithms, cleanup(), dns_rbtnode::data, dns_rbt_addnode(), dns_rbt_create(), free_algorithm(), isc_mem_get, isc_mem_put, ISC_R_EXISTS, ISC_R_NOMEMORY, ISC_R_RANGE, ISC_R_SUCCESS, isc_rwlocktype_write, dns_resolver::mctx, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by disable_algorithms().

isc_result_t dns_resolver_disable_ds_digest	(	dns_resolver_t *	resolver,
		dns_name_t *	name,
		unsigned int	digest_type
	)

Mark the given DS/DLV digest type as disabled and below 'name'. Valid types are less than 256.

Returns:

• ISC_R_SUCCESS
• ISC_R_RANGE
• ISC_R_NOMEMORY

Definition at line 9465 of file resolver.c.

References cleanup(), dns_rbtnode::data, dns_rbt_addnode(), dns_rbt_create(), free_digest(), isc_mem_get, isc_mem_put, ISC_R_EXISTS, ISC_R_NOMEMORY, ISC_R_RANGE, ISC_R_SUCCESS, isc_rwlocktype_write, dns_resolver::mctx, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by disable_ds_digests().

isc_boolean_t dns_resolver_algorithm_supported	(	dns_resolver_t *	resolver,
		dns_name_t *	name,
		unsigned int	alg
	)

Check if the given algorithm is supported by this resolver. This checks whether the algorithm has been disabled via dns_resolver_disable_algorithm(), then checks the underlying crypto libraries if it was not specifically disabled.

Definition at line 9408 of file resolver.c.

References algorithms, DNS_R_PARTIALMATCH, dns_rbt_findname(), dst_algorithm_supported(), ISC_FALSE, ISC_R_SUCCESS, isc_rwlocktype_read, ISC_TRUE, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by check_ds(), dlv_algorithm_supported(), dlv_validatezonekey(), validate(), and validatezonekey().

isc_boolean_t dns_resolver_ds_digest_supported	(	dns_resolver_t *	resolver,
		dns_name_t *	name,
		unsigned int	digest_type
	)

Check if the given digest type is supported by this resolver. This checks whether the digest type has been disabled via dns_resolver_disable_ds_digest(), then checks the underlying crypto libraries if it was not specifically disabled.

Definition at line 9536 of file resolver.c.

References DNS_R_PARTIALMATCH, dns_rbt_findname(), dst_ds_digest_supported(), ISC_FALSE, ISC_R_SUCCESS, isc_rwlocktype_read, ISC_TRUE, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by check_ds(), dlv_algorithm_supported(), dlv_validatezonekey(), and validatezonekey().

void dns_resolver_resetmustbesecure

(

dns_resolver_t *

resolver

)

Definition at line 9570 of file resolver.c.

References dns_rbt_destroy(), isc_rwlocktype_write, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by configure_view(), and destroy().

isc_result_t dns_resolver_setmustbesecure	(	dns_resolver_t *	resolver,
		dns_name_t *	name,
		isc_boolean_t	value
	)

Definition at line 9587 of file resolver.c.

References cleanup(), dns_rbt_addname(), dns_rbt_create(), ISC_R_SUCCESS, isc_rwlocktype_write, dns_resolver::mctx, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by mustbesecure().

isc_boolean_t dns_resolver_getmustbesecure	(	dns_resolver_t *	resolver,
		dns_name_t *	name
	)

Definition at line 9613 of file resolver.c.

References DNS_R_PARTIALMATCH, dns_rbt_findname(), ISC_FALSE, ISC_R_SUCCESS, isc_rwlocktype_read, REQUIRE, RWLOCK, RWUNLOCK, and VALID_RESOLVER.

Referenced by dns_validator_create().

void dns_resolver_settimeout	(	dns_resolver_t *	resolver,
		unsigned int	seconds
	)

Set the length of time the resolver will work on a query, in seconds.

If timeout is 0, the default timeout will be applied.

Requires:

• resolver to be valid.

Definition at line 9692 of file resolver.c.

References DEFAULT_QUERY_TIMEOUT, MAXIMUM_QUERY_TIMEOUT, MINIMUM_QUERY_TIMEOUT, REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

unsigned int dns_resolver_gettimeout

(

dns_resolver_t *

resolver

)

Get the current length of time the resolver will work on a query, in seconds.

Requires:

• resolver to be valid.

Definition at line 9685 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

void dns_resolver_setclientsperquery	(	dns_resolver_t *	resolver,
		isc_uint32_t	min,
		isc_uint32_t	max
	)

Definition at line 9652 of file resolver.c.

References dns_resolver::lock, LOCK, REQUIRE, UNLOCK, and VALID_RESOLVER.

Referenced by configure_view().

void dns_resolver_getclientsperquery	(	dns_resolver_t *	resolver,
		isc_uint32_t *	cur,
		isc_uint32_t *	min,
		isc_uint32_t *	max
	)

Definition at line 9636 of file resolver.c.

References dns_resolver::lock, LOCK, REQUIRE, UNLOCK, and VALID_RESOLVER.

isc_boolean_t dns_resolver_getzeronosoattl

(

dns_resolver_t *

resolver

)

Definition at line 9664 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

Referenced by cache_reusable().

void dns_resolver_setzeronosoattl	(	dns_resolver_t *	resolver,
		isc_boolean_t	state
	)

Definition at line 9671 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

unsigned int dns_resolver_getoptions

(

dns_resolver_t *

resolver

)

Definition at line 9678 of file resolver.c.

References dns_resolver::options, REQUIRE, and VALID_RESOLVER.

void dns_resolver_addbadcache	(	dns_resolver_t *	resolver,
		dns_name_t *	name,
		dns_rdatatype_t	type,
		isc_time_t *	expire
	)

Add a entry to the bad cache for <name,type> that will expire at 'expire'.

Requires:

• resolver to be valid.
• name to be valid.

Definition at line 9290 of file resolver.c.

References dns_badcache_add(), and ISC_FALSE.

Referenced by fctx_getaddresses().

isc_boolean_t dns_resolver_getbadcache	(	dns_resolver_t *	resolver,
		dns_name_t *	name,
		dns_rdatatype_t	type,
		isc_time_t *	now
	)

Check to see if there is a unexpired entry in the bad cache for <name,type>.

Requires:

• resolver to be valid.
• name to be valid.

Definition at line 9298 of file resolver.c.

References dns_badcache_find().

Referenced by view_find().

void dns_resolver_flushbadcache	(	dns_resolver_t *	resolver,
		dns_name_t *	name
	)

Flush the bad cache of all entries at 'name' if 'name' is non NULL. Flush the entire bad cache if 'name' is NULL.

Requires:

• resolver to be valid.

Definition at line 9277 of file resolver.c.

References dns_badcache_flush(), and dns_badcache_flushname().

Referenced by dns_view_flushcache2(), and dns_view_flushnode().

void dns_resolver_flushbadnames	(	dns_resolver_t *	resolver,
		dns_name_t *	name
	)

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

Requires:

• resolver to be valid.
• name != NULL

Definition at line 9285 of file resolver.c.

References dns_badcache_flushtree().

Referenced by dns_view_flushnode().

void dns_resolver_printbadcache	(	dns_resolver_t *	resolver,
		FILE *	fp
	)

Definition at line 9305 of file resolver.c.

References dns_badcache_print().

Referenced by dns_view_dumpdbtostream(), and dumpdone().

void dns_resolver_setquerydscp4	(	dns_resolver_t *	resolver,
		isc_dscp_t	dscp
	)

Print out the contents of the bad cache to 'fp'.

Requires:

• resolver to be valid.

Definition at line 9706 of file resolver.c.

References dns_resolver::querydscp4, REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

isc_dscp_t dns_resolver_getquerydscp4

(

dns_resolver_t *

resolver

)

Definition at line 9713 of file resolver.c.

References dns_resolver::querydscp4, REQUIRE, and VALID_RESOLVER.

Referenced by fctx_query().

void dns_resolver_setquerydscp6	(	dns_resolver_t *	resolver,
		isc_dscp_t	dscp
	)

Definition at line 9719 of file resolver.c.

References dns_resolver::querydscp6, REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

isc_dscp_t dns_resolver_getquerydscp6

(

dns_resolver_t *

resolver

)

Definition at line 9726 of file resolver.c.

References dns_resolver::querydscp6, REQUIRE, and VALID_RESOLVER.

Referenced by fctx_query().

void dns_resolver_setmaxdepth	(	dns_resolver_t *	resolver,
		unsigned int	maxdepth
	)

Get and set the DSCP values for the resolver's IPv4 and IPV6 query sources.

Requires:

• resolver to be valid.

Definition at line 9732 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

unsigned int dns_resolver_getmaxdepth

(

dns_resolver_t *

resolver

)

Definition at line 9738 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

void dns_resolver_setmaxqueries	(	dns_resolver_t *	resolver,
		unsigned int	queries
	)

Get and set how many NS indirections will be followed when looking for nameserver addresses.

Requires:

• resolver to be valid.

Definition at line 9744 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

Referenced by configure_view().

unsigned int dns_resolver_getmaxqueries

(

dns_resolver_t *

resolver

)

Definition at line 9750 of file resolver.c.

References REQUIRE, and VALID_RESOLVER.

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