lib » dns » include » dns

client.h File Reference

The DNS client module provides convenient programming interfaces to various DNS services, such as name resolution with or without DNSSEC validation or dynamic DNS update. This module is primarily expected to be used by other applications than BIND9-related ones that need such advanced DNS features. More...

#include <isc/event.h>
#include <isc/sockaddr.h>
#include <dns/tsig.h>
#include <dns/types.h>
#include <dst/dst.h>

Go to the source code of this file.

Data Structures

struct dns_clientresevent

A dns_clientresevent_t is sent when name resolution performed by a client completes. 'result' stores the result code of the entire resolution procedure. 'vresult' specifically stores the result code of DNSSEC validation if it is performed. When name resolution successfully completes, 'answerlist' is typically non empty, containing answer names along with RRsets. It is the receiver's responsibility to free this list by calling dns_client_freeresanswer() before freeing the event structure. More...

struct dns_clientreqevent

A dns_clientreqevent_t is sent when a DNS request is completed by a client. 'result' stores the result code of the entire transaction. If the transaction is successfully completed but the response packet cannot be parsed, 'result' will store the result code of dns_message_parse(). If the response packet is received, 'rmessage' will contain the response message, whether it is successfully parsed or not. More...

struct dns_clientupdateevent

A dns_clientupdateevent_t is sent when dynamic update performed by a client completes. 'result' stores the result code of the entire update procedure. 'state' specifies the status of the update procedure when this event is sent. This can be used as a hint by the receiver to determine whether the update attempt was ever made. In particular, if the state is dns_clientupdatestate_prepare, the receiver can be sure that the requested update was not applied. More...

Defines

#define DNS_CLIENT_H   1

#define DNS_CLIENTCREATEOPT_USECACHE   0x8000

Optional flags for dns_client_create(x).

#define DNS_CLIENTRESOPT_NODNSSEC   0x01

Optional flags for dns_client_(start)resolve.

#define DNS_CLIENTRESOPT_ALLOWRUN   0x02

Don't validate responses.

#define DNS_CLIENTRESOPT_NOVALIDATE   0x04

Don't set the CD flag on upstream queries.

#define DNS_CLIENTRESOPT_NOCDFLAG   0x08

Use TCP transport.

#define DNS_CLIENTRESOPT_TCP   0x10

#define DNS_CLIENTREQOPT_ALLOWRUN   0x01

Optional flags for dns_client_(start)request.

#define DNS_CLIENTREQOPT_TCP   0x02

#define DNS_CLIENTUPDOPT_ALLOWRUN   0x01

Optional flags for dns_client_(start)update.

#define DNS_CLIENTUPDOPT_TCP   0x02

Typedefs

typedef struct dns_clientresevent dns_clientresevent_t

typedef struct dns_clientreqevent dns_clientreqevent_t

typedef struct
dns_clientupdateevent dns_clientupdateevent_t

Enumerations

enum dns_client_updateop_t {
  updateop_none = 0, updateop_add = 1, updateop_delete = 2, updateop_exist = 3,
  updateop_notexist = 4, updateop_max = 5
}

enum dns_clientupdatestate_t { dns_clientupdatestate_prepare, dns_clientupdatestate_sent, dns_clientupdatestate_done }

Status of a dynamic update procedure. More...

Functions

isc_result_t dns_client_create (dns_client_t **clientp, unsigned int options)

isc_result_t dns_client_createx (isc_mem_t *mctx, isc_appctx_t *actx, isc_taskmgr_t *taskmgr, isc_socketmgr_t *socketmgr, isc_timermgr_t *timermgr, unsigned int options, dns_client_t **clientp)

isc_result_t dns_client_createx2 (isc_mem_t *mctx, isc_appctx_t *actx, isc_taskmgr_t *taskmgr, isc_socketmgr_t *socketmgr, isc_timermgr_t *timermgr, unsigned int options, dns_client_t **clientp, isc_sockaddr_t *localaddr4, isc_sockaddr_t *localaddr6)

Create a DNS client. These functions create a new client object with minimal internal resources such as the default 'view' for the IN class and IPv4/IPv6 dispatches for the view.

void dns_client_destroy (dns_client_t **clientp)

Destroy 'client'.

isc_result_t dns_client_setservers (dns_client_t *client, dns_rdataclass_t rdclass, dns_name_t *namespace, isc_sockaddrlist_t *addrs)

Specify a list of addresses of recursive name servers that the client will use for name resolution. A view for the 'rdclass' class must be created beforehand. If 'namespace' is non NULL, the specified server will be used if and only if the query name is a subdomain of 'namespace'. When servers for multiple 'namespace's are provided, and a query name is covered by more than one 'namespace', the servers for the best (longest) matching namespace will be used. If 'namespace' is NULL, it works as if dns_rootname (.) were specified.

isc_result_t dns_client_clearservers (dns_client_t *client, dns_rdataclass_t rdclass, dns_name_t *namespace)

Remove configured recursive name servers for the 'rdclass' and 'namespace' from the client. See the description of dns_client_setservers() for the requirements about 'rdclass' and 'namespace'.

isc_result_t dns_client_setdlv (dns_client_t *client, dns_rdataclass_t rdclass, const char *dlvname)

Specify a name to use for DNSSEC lookaside validation (e.g., "dlv.isc.org"). If a trusted key has been added for that name, then DLV will be used during validation. If 'dlvname' is NULL, then DLV will no longer be used for this client.

isc_result_t dns_client_resolve (dns_client_t *client, dns_name_t *name, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int options, dns_namelist_t *namelist)

isc_result_t dns_client_startresolve (dns_client_t *client, dns_name_t *name, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int options, isc_task_t *task, isc_taskaction_t action, void *arg, dns_clientrestrans_t **transp)

Perform name resolution for 'name', 'rdclass', and 'type'.

void dns_client_cancelresolve (dns_clientrestrans_t *trans)

Cancel an ongoing resolution procedure started via dns_client_startresolve().

void dns_client_destroyrestrans (dns_clientrestrans_t **transp)

Destroy name resolution transaction state identified by '*transp'.

void dns_client_freeresanswer (dns_client_t *client, dns_namelist_t *namelist)

Free resources allocated for the content of 'namelist'.

isc_result_t dns_client_addtrustedkey (dns_client_t *client, dns_rdataclass_t rdclass, dns_name_t *keyname, isc_buffer_t *keydatabuf)

Add a DNSSEC trusted key for the 'rdclass' class. A view for the 'rdclass' class must be created beforehand. 'keyname' is the DNS name of the key, and 'keydatabuf' stores the resource data of the key.

isc_result_t dns_client_request (dns_client_t *client, dns_message_t *qmessage, dns_message_t *rmessage, isc_sockaddr_t *server, unsigned int options, unsigned int parseoptions, dns_tsec_t *tsec, unsigned int timeout, unsigned int udptimeout, unsigned int udpretries)

isc_result_t dns_client_startrequest (dns_client_t *client, dns_message_t *qmessage, dns_message_t *rmessage, isc_sockaddr_t *server, unsigned int options, unsigned int parseoptions, dns_tsec_t *tsec, unsigned int timeout, unsigned int udptimeout, unsigned int udpretries, isc_task_t *task, isc_taskaction_t action, void *arg, dns_clientreqtrans_t **transp)

Send a DNS request containig a query message 'query' to 'server'.

void dns_client_cancelrequest (dns_clientreqtrans_t *transp)

Cancel an ongoing DNS request procedure started via dns_client_startrequest().

void dns_client_destroyreqtrans (dns_clientreqtrans_t **transp)

isc_result_t dns_client_update (dns_client_t *client, dns_rdataclass_t rdclass, dns_name_t *zonename, dns_namelist_t *prerequisites, dns_namelist_t *updates, isc_sockaddrlist_t *servers, dns_tsec_t *tsec, unsigned int options)

Destroy DNS request transaction state identified by '*transp'.

isc_result_t dns_client_startupdate (dns_client_t *client, dns_rdataclass_t rdclass, dns_name_t *zonename, dns_namelist_t *prerequisites, dns_namelist_t *updates, isc_sockaddrlist_t *servers, dns_tsec_t *tsec, unsigned int options, isc_task_t *task, isc_taskaction_t action, void *arg, dns_clientupdatetrans_t **transp)

Perform DNS dynamic update for 'updates' of the 'rdclass' class with optional 'prerequisites'.

void dns_client_cancelupdate (dns_clientupdatetrans_t *trans)

Cancel an ongoing dynamic update procedure started via dns_client_startupdate().

void dns_client_destroyupdatetrans (dns_clientupdatetrans_t **transp)

Destroy dynamic update transaction identified by '*transp'.

isc_result_t dns_client_updaterec (dns_client_updateop_t op, dns_name_t *owner, dns_rdatatype_t type, dns_rdata_t *source, dns_ttl_t ttl, dns_name_t *target, dns_rdataset_t *rdataset, dns_rdatalist_t *rdatalist, dns_rdata_t *rdata, isc_mem_t *mctx)

TBD.

void dns_client_freeupdate (dns_name_t **namep)

TBD.

isc_mem_t * dns_client_mctx (dns_client_t *client)

Detailed Description

MP:

In the typical usage of this module, application threads will not share the same data structures created and manipulated in this module. However, the module still ensures appropriate synchronization of such data structures.

Resources:

Security:

This module does not handle any low-level data directly, and so no security issue specific to this module is anticipated.

Definition in file client.h.

Define Documentation

#define DNS_CLIENT_H 1

Definition at line 20 of file client.h.

#define DNS_CLIENTCREATEOPT_USECACHE 0x8000

Optional flags for dns_client_create(x).

< Enable caching resolution results (experimental).

Definition at line 75 of file client.h.

Referenced by createview().

#define DNS_CLIENTRESOPT_NODNSSEC 0x01

Optional flags for dns_client_(start)resolve.

< Do not return DNSSEC data (e.g. RRSIGS) with response. Allow running external context.

Definition at line 81 of file client.h.

Referenced by dns_client_startresolve().

#define DNS_CLIENTRESOPT_ALLOWRUN 0x02

Don't validate responses.

Definition at line 83 of file client.h.

Referenced by dns_client_resolve().

#define DNS_CLIENTRESOPT_NOVALIDATE 0x04

Don't set the CD flag on upstream queries.

Definition at line 85 of file client.h.

Referenced by dns_client_startresolve().

#define DNS_CLIENTRESOPT_NOCDFLAG 0x08

Use TCP transport.

Definition at line 87 of file client.h.

Referenced by dns_client_startresolve().

#define DNS_CLIENTRESOPT_TCP 0x10

Definition at line 89 of file client.h.

Referenced by dns_client_startresolve(), dns_client_startupdate(), process_soa(), and resolvesoa_done().

#define DNS_CLIENTREQOPT_ALLOWRUN 0x01

Optional flags for dns_client_(start)request.

< Allow running external context. Use TCP transport.

Definition at line 95 of file client.h.

Referenced by dns_client_request().

#define DNS_CLIENTREQOPT_TCP 0x02

Definition at line 97 of file client.h.

Referenced by dns_client_startrequest().

#define DNS_CLIENTUPDOPT_ALLOWRUN 0x01

Optional flags for dns_client_(start)update.

< Allow running external context. Use TCP transport.

Definition at line 103 of file client.h.

Referenced by dns_client_update().

#define DNS_CLIENTUPDOPT_TCP 0x02

Definition at line 105 of file client.h.

Referenced by dns_client_startupdate().

Typedef Documentation

typedef struct dns_clientresevent dns_clientresevent_t

typedef struct dns_clientreqevent dns_clientreqevent_t

typedef struct dns_clientupdateevent dns_clientupdateevent_t

Enumeration Type Documentation

enum dns_client_updateop_t

Enumerator:

updateop_none
updateop_add
updateop_delete
updateop_exist
updateop_notexist
updateop_max

Definition at line 56 of file client.h.

enum dns_clientupdatestate_t

Status of a dynamic update procedure.

Enumerator:

dns_clientupdatestate_prepare	no updates have been sent
dns_clientupdatestate_sent	updates were sent, no response
dns_clientupdatestate_done	update was sent and succeeded

Definition at line 126 of file client.h.

Function Documentation

isc_result_t dns_client_create	(	dns_client_t **	clientp,
		unsigned int	options
	)

isc_result_t dns_client_createx	(	isc_mem_t *	mctx,
		isc_appctx_t *	actx,
		isc_taskmgr_t *	taskmgr,
		isc_socketmgr_t *	socketmgr,
		isc_timermgr_t *	timermgr,
		unsigned int	options,
		dns_client_t **	clientp
	)

Definition at line 436 of file client.c.

References dns_client_createx2().

Referenced by dns_client_create().

isc_result_t dns_client_createx2	(	isc_mem_t *	mctx,
		isc_appctx_t *	actx,
		isc_taskmgr_t *	taskmgr,
		isc_socketmgr_t *	socketmgr,
		isc_timermgr_t *	timermgr,
		unsigned int	options,
		dns_client_t **	clientp,
		isc_sockaddr_t *	localaddr4,
		isc_sockaddr_t *	localaddr6
	)

Create a DNS client. These functions create a new client object with minimal internal resources such as the default 'view' for the IN class and IPv4/IPv6 dispatches for the view.

dns_client_createx() takes 'manager' arguments so that the caller can control the behavior of the client through the underlying event framework. On the other hand, dns_client_create() simplifies the interface and creates the managers internally. A DNS client object created via dns_client_create() is expected to be used by an application that only needs simple synchronous services or by a thread-based application.

dns_client_createx2 takes two additional parameters, 'localaddr4' and 'localaddr6', to specify the local address to use for each family. If both are set to NULL, then wildcard addresses will be used for both families. If only one is NULL, then the other address will be used as the local address, and the other protocol family will not be used.

If the DNS_CLIENTCREATEOPT_USECACHE flag is set in 'options', dns_client_create(x) will create a cache database with the view.

Requires:

'mctx' is a valid memory context.

'actx' is a valid application context.

'taskmgr' is a valid task manager.

'socketmgr' is a valid socket manager.

'timermgr' is a valid timer manager.

clientp != NULL && *clientp == NULL.

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Definition at line 447 of file client.c.

References dns_client::actx, AF_INET6, dns_client::attributes, cleanup(), createview(), DEF_FIND_TIMEOUT, DEF_FIND_UDPRETRIES, DEF_UPDATE_TIMEOUT, DEF_UPDATE_UDPRETRIES, DEF_UPDATE_UDPTIMEOUT, dns_client::dispatchmgr, dns_client::dispatchv4, dns_client::dispatchv6, DNS_CLIENT_MAGIC, dns_dispatch_detach(), dns_dispatchmgr_create(), dns_dispatchmgr_destroy(), dns_view_freeze(), dns_client::find_timeout, dns_client::find_udpretries, getudpdispatch(), INSIST, ISC_LIST_APPEND, ISC_LIST_INIT, isc_mem_attach(), isc_mem_get, isc_mem_put, isc_mutex_init, ISC_R_NOMEMORY, ISC_R_SUCCESS, isc_task_create(), isc_task_detach(), ISC_TRUE, dns_client::lock, dns_client::magic, dns_client::mctx, dns_client::references, REQUIRE, RESOLVER_NTASKS, dns_client::socketmgr, dns_client::task, dns_client::taskmgr, dns_client::timermgr, dns_client::update_timeout, dns_client::update_udpretries, dns_client::update_udptimeout, and dns_client::viewlist.

Referenced by dns_client_createx().

void dns_client_destroy ( dns_client_t ** clientp )

Destroy 'client'.

Requires:

'*clientp' is a valid client.

Ensures:

*clientp == NULL.

Definition at line 606 of file client.c.

References destroyclient(), DNS_CLIENT_VALID, ISC_FALSE, ISC_LIST_EMPTY, ISC_TRUE, dns_client::lock, LOCK, dns_client::references, REQUIRE, and UNLOCK.

isc_result_t dns_client_setservers	(	dns_client_t *	client,
		dns_rdataclass_t	rdclass,
		dns_name_t *	namespace,
		isc_sockaddrlist_t *	addrs
	)

Specify a list of addresses of recursive name servers that the client will use for name resolution. A view for the 'rdclass' class must be created beforehand. If 'namespace' is non NULL, the specified server will be used if and only if the query name is a subdomain of 'namespace'. When servers for multiple 'namespace's are provided, and a query name is covered by more than one 'namespace', the servers for the best (longest) matching namespace will be used. If 'namespace' is NULL, it works as if dns_rootname (.) were specified.

Requires:

'client' is a valid client.

'namespace' is NULL or a valid name.

'addrs' != NULL.

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Definition at line 630 of file client.c.

References DNS_CLIENT_VALID, DNS_CLIENTVIEW_NAME, dns_fwdpolicy_only, dns_fwdtable_add(), dns_rootname, dns_view_detach(), dns_viewlist_find(), dns_view::fwdtable, ISC_R_SUCCESS, dns_client::lock, LOCK, REQUIRE, UNLOCK, and dns_client::viewlist.

isc_result_t dns_client_clearservers	(	dns_client_t *	client,
		dns_rdataclass_t	rdclass,
		dns_name_t *	namespace
	)

Remove configured recursive name servers for the 'rdclass' and 'namespace' from the client. See the description of dns_client_setservers() for the requirements about 'rdclass' and 'namespace'.

Requires:

'client' is a valid client.

'namespace' is NULL or a valid name.

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Definition at line 660 of file client.c.

References DNS_CLIENT_VALID, DNS_CLIENTVIEW_NAME, dns_fwdtable_delete(), dns_rootname, dns_view_detach(), dns_viewlist_find(), dns_view::fwdtable, ISC_R_SUCCESS, dns_client::lock, LOCK, REQUIRE, UNLOCK, and dns_client::viewlist.

isc_result_t dns_client_setdlv	(	dns_client_t *	client,
		dns_rdataclass_t	rdclass,
		const char *	dlvname
	)

Specify a name to use for DNSSEC lookaside validation (e.g., "dlv.isc.org"). If a trusted key has been added for that name, then DLV will be used during validation. If 'dlvname' is NULL, then DLV will no longer be used for this client.

Requires:

'client' is a valid client.

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Definition at line 688 of file client.c.

References cleanup(), dns_view::dlv, dns_view::dlv_fixed, DNS_CLIENT_VALID, DNS_CLIENTVIEW_NAME, dns_fixedname_name, DNS_NAME_DOWNCASE, dns_name_fromtext(), dns_rootname, dns_view_detach(), dns_viewlist_find(), isc_buffer_add, isc_buffer_constinit, ISC_R_SUCCESS, dns_client::lock, LOCK, REQUIRE, UNLOCK, and dns_client::viewlist.

isc_result_t dns_client_resolve	(	dns_client_t *	client,
		dns_name_t *	name,
		dns_rdataclass_t	rdclass,
		dns_rdatatype_t	type,
		unsigned int	options,
		dns_namelist_t *	namelist
	)

isc_result_t dns_client_startresolve	(	dns_client_t *	client,
		dns_name_t *	name,
		dns_rdataclass_t	rdclass,
		dns_rdatatype_t	type,
		unsigned int	options,
		isc_task_t *	task,
		isc_taskaction_t	action,
		void *	arg,
		dns_clientrestrans_t **	transp
	)

Perform name resolution for 'name', 'rdclass', and 'type'.

If any trusted keys are configured and the query name is considered to belong to a secure zone, these functions also validate the responses using DNSSEC by default. If the DNS_CLIENTRESOPT_NOVALIDATE flag is set in 'options', DNSSEC validation is disabled regardless of the configured trusted keys or the query name. With DNS_CLIENTRESOPT_NODNSSEC DNSSEC data is not returned with response. DNS_CLIENTRESOPT_NOCDFLAG disables the CD flag on queries, DNS_CLIENTRESOPT_TCP switches to the TCP (vs. UDP) transport.

dns_client_resolve() provides a synchronous service. This function starts name resolution internally and blocks until it completes. On success, 'namelist' will contain a list of answer names, each of which has corresponding RRsets. The caller must provide a valid empty list, and is responsible for freeing the list content via dns_client_freeresanswer(). If the name resolution fails due to an error in DNSSEC validation, dns_client_resolve() returns the result code indicating the validation error. Otherwise, it returns the result code of the entire resolution process, either success or failure.

It is typically expected that the client object passed to dns_client_resolve() was created via dns_client_create() and has its own managers and contexts. However, if the DNS_CLIENTRESOPT_ALLOWRUN flag is set in 'options', this function performs the synchronous service even if it does not have its own manager and context structures.

dns_client_startresolve() is an asynchronous version of dns_client_resolve() and does not block. When name resolution is completed, 'action' will be called with the argument of a 'dns_clientresevent_t' object, which contains the resulting list of answer names (on success). On return, '*transp' is set to an opaque transaction ID so that the caller can cancel this resolution process.

Requires:

'client' is a valid client.

'addrs' != NULL.

'name' is a valid name.

'namelist' != NULL and is not empty.

'task' is a valid task.

'transp' != NULL && *transp == NULL;

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Definition at line 1325 of file client.c.

References resctx::canceled, cleanup(), resctx::client, client_resfind(), DESTROYLOCK, DNS_CLIENT_VALID, DNS_CLIENTRESOPT_NOCDFLAG, DNS_CLIENTRESOPT_NODNSSEC, DNS_CLIENTRESOPT_NOVALIDATE, DNS_CLIENTRESOPT_TCP, DNS_CLIENTVIEW_NAME, DNS_EVENT_CLIENTRESDONE, dns_fixedname_init, dns_fixedname_name, dns_name_copy(), DNS_R_SERVFAIL, dns_view_detach(), dns_viewlist_find(), resctx::event, resctx::fetch, getrdataset(), isc_event_allocate(), isc_event_free(), ISC_EVENT_PTR, ISC_FALSE, ISC_LINK_INIT, ISC_LIST_APPEND, ISC_LIST_INIT, isc_mem_get, isc_mem_put, isc_mutex_init, ISC_R_NOMEMORY, ISC_R_SUCCESS, isc_task_attach(), isc_task_detach(), ISC_TF, resctx::lock, dns_client::lock, LOCK, resctx::magic, dns_client::mctx, resctx::name, resctx::namelist, putrdataset(), RCTX_MAGIC, resctx::rdataset, REQUIRE, resctx::restarts, resctx::sigrdataset, dns_client::task, resctx::task, resctx::type, UNLOCK, resctx::view, dns_client::viewlist, resctx::want_cdflag, resctx::want_dnssec, resctx::want_tcp, and resctx::want_validation.

Referenced by dns_client_resolve(), dns_client_startupdate(), process_soa(), and resolvesoa_done().

void dns_client_cancelresolve ( dns_clientrestrans_t * trans )

Cancel an ongoing resolution procedure started via dns_client_startresolve().

Notes:

If the resolution procedure has not completed, post its CLIENTRESDONE event with a result code of ISC_R_CANCELED.

Requires:

'trans' is a valid transaction ID.

Definition at line 1447 of file client.c.

References resctx::canceled, dns_resolver_cancelfetch(), resctx::fetch, ISC_TRUE, resctx::lock, LOCK, RCTX_VALID, REQUIRE, and UNLOCK.

Referenced by dns_client_cancelupdate(), dns_client_request(), and dns_client_resolve().

void dns_client_destroyrestrans ( dns_clientrestrans_t ** transp )

Destroy name resolution transaction state identified by '*transp'.

Requires:

'*transp' is a valid transaction ID.

The caller has received the CLIENTRESDONE event (either because the resolution completed or because dns_client_cancelresolve() was called).

Ensures:

*transp == NULL.

Definition at line 1485 of file client.c.

References resctx::client, destroyclient(), DESTROYLOCK, DNS_CLIENT_VALID, dns_view_detach(), resctx::event, resctx::fetch, INSIST, ISC_FALSE, ISC_LINK_LINKED, ISC_LIST_EMPTY, ISC_LIST_UNLINK, isc_mem_put, ISC_TRUE, resctx::lock, dns_client::lock, LOCK, resctx::magic, dns_client::mctx, resctx::namelist, RCTX_VALID, dns_client::references, REQUIRE, UNLOCK, and resctx::view.

Referenced by resolve_done(), resolveaddr_done(), and resolvesoa_done().

void dns_client_freeresanswer	(	dns_client_t *	client,
		dns_namelist_t *	namelist
	)

Free resources allocated for the content of 'namelist'.

Requires:

'client' is a valid client.

'namelist' != NULL.

Definition at line 1466 of file client.c.

References DNS_CLIENT_VALID, dns_name_free(), ISC_LIST_HEAD, ISC_LIST_UNLINK, isc_mem_put, dns_client::mctx, name, putrdataset(), and REQUIRE.

Referenced by resolveaddr_done(), and resolvesoa_done().

isc_result_t dns_client_addtrustedkey	(	dns_client_t *	client,
		dns_rdataclass_t	rdclass,
		dns_name_t *	keyname,
		isc_buffer_t *	keydatabuf
	)

Add a DNSSEC trusted key for the 'rdclass' class. A view for the 'rdclass' class must be created beforehand. 'keyname' is the DNS name of the key, and 'keydatabuf' stores the resource data of the key.

Requires:

'client' is a valid client.

'keyname' is a valid name.

'keydatabuf' is a valid buffer.

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Definition at line 1528 of file client.c.

References cleanup(), DNS_CLIENT_VALID, DNS_CLIENTVIEW_NAME, dns_keytable_add(), dns_keytable_detach(), dns_view_detach(), dns_view_getsecroots(), dns_viewlist_find(), dst_key_free(), dst_key_fromdns(), ISC_FALSE, ISC_R_SUCCESS, dns_client::lock, LOCK, dns_client::mctx, REQUIRE, UNLOCK, and dns_client::viewlist.

isc_result_t dns_client_request	(	dns_client_t *	client,
		dns_message_t *	qmessage,
		dns_message_t *	rmessage,
		isc_sockaddr_t *	server,
		unsigned int	options,
		unsigned int	parseoptions,
		dns_tsec_t *	tsec,
		unsigned int	timeout,
		unsigned int	udptimeout,
		unsigned int	udpretries
	)

isc_result_t dns_client_startrequest	(	dns_client_t *	client,
		dns_message_t *	qmessage,
		dns_message_t *	rmessage,
		isc_sockaddr_t *	server,
		unsigned int	options,
		unsigned int	parseoptions,
		dns_tsec_t *	tsec,
		unsigned int	timeout,
		unsigned int	udptimeout,
		unsigned int	udpretries,
		isc_task_t *	task,
		isc_taskaction_t	action,
		void *	arg,
		dns_clientreqtrans_t **	transp
	)

Send a DNS request containig a query message 'query' to 'server'.

'parseoptions' will be used when the response packet is parsed, and will be passed to dns_message_parse() via dns_request_getresponse(). See dns_message_parse() for more details.

'tsec' is a transaction security object containing, e.g. a TSIG key for authenticating the request/response transaction. This is optional and can be NULL, in which case this library performs the transaction without any transaction authentication.

'timeout', 'udptimeout', and 'udpretries' are passed to dns_request_createvia3(). See dns_request_createvia3() for more details.

dns_client_request() provides a synchronous service. This function sends the request and blocks until a response is received. On success, 'rmessage' will contain the response message. The caller must provide a valid initialized message.

It is usually expected that the client object passed to dns_client_request() was created via dns_client_create() and has its own managers and contexts. However, if the DNS_CLIENTREQOPT_ALLOWRUN flag is set in 'options', this function performs the synchronous service even if it does not have its own manager and context structures.

dns_client_startrequest() is an asynchronous version of dns_client_request() and does not block. When the transaction is completed, 'action' will be called with the argument of a 'dns_clientreqevent_t' object, which contains the response message (on success). On return, '*transp' is set to an opaque transaction ID so that the caller can cancel this request.

DNS_CLIENTREQOPT_TCP switches to the TCP (vs. UDP) transport.

Requires:

'client' is a valid client.

'qmessage' and 'rmessage' are valid initialized message.

'server' is a valid socket address structure.

'task' is a valid task.

'transp' != NULL && *transp == NULL;

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Any result that dns_message_parse() can return.

Definition at line 1722 of file client.c.

References reqctx::canceled, cleanup(), reqctx::client, DESTROYLOCK, DNS_CLIENT_VALID, DNS_CLIENTREQOPT_TCP, DNS_CLIENTVIEW_NAME, DNS_EVENT_CLIENTREQDONE, dns_request_createvia3(), DNS_REQUESTOPT_TCP, dns_tsec_getkey(), dns_tsec_gettype(), dns_tsectype_none, dns_tsectype_tsig, dns_view_detach(), dns_viewlist_find(), reqctx::event, isc_event_allocate(), isc_event_free(), ISC_EVENT_PTR, ISC_FALSE, ISC_LINK_INIT, ISC_LIST_APPEND, ISC_LIST_UNLINK, isc_mem_get, isc_mem_put, isc_mutex_init, ISC_R_NOMEMORY, ISC_R_NOTIMPLEMENTED, ISC_R_SUCCESS, isc_task_attach(), isc_task_detach(), reqctx::lock, dns_client::lock, LOCK, reqctx::magic, dns_client::mctx, reqctx::parseoptions, dns_message::rdclass, REQCTX_MAGIC, reqctx::request, request_done(), dns_view::requestmgr, REQUIRE, dns_clientreqevent::rmessage, dns_client::task, reqctx::tsigkey, UNLOCK, and dns_client::viewlist.

Referenced by dns_client_request().

void dns_client_cancelrequest ( dns_clientreqtrans_t * transp )

Cancel an ongoing DNS request procedure started via dns_client_startrequest().

Notes:

If the request procedure has not completed, post its CLIENTREQDONE event with a result code of ISC_R_CANCELED.

Requires:

'trans' is a valid transaction ID.

Definition at line 1829 of file client.c.

References reqctx::canceled, dns_request_cancel(), ISC_TRUE, reqctx::lock, LOCK, REQCTX_VALID, reqctx::request, REQUIRE, and UNLOCK.

void dns_client_destroyreqtrans ( dns_clientreqtrans_t ** transp )

Definition at line 1848 of file client.c.

References reqctx::client, destroyclient(), DESTROYLOCK, DNS_CLIENT_VALID, dns_request_destroy(), reqctx::event, INSIST, ISC_FALSE, ISC_LINK_LINKED, ISC_LIST_EMPTY, ISC_LIST_UNLINK, isc_mem_put, ISC_TRUE, reqctx::lock, dns_client::lock, LOCK, reqctx::magic, dns_client::mctx, dns_client::references, REQCTX_VALID, reqctx::request, REQUIRE, and UNLOCK.

Referenced by localrequest_done().

isc_result_t dns_client_update	(	dns_client_t *	client,
		dns_rdataclass_t	rdclass,
		dns_name_t *	zonename,
		dns_namelist_t *	prerequisites,
		dns_namelist_t *	updates,
		isc_sockaddrlist_t *	servers,
		dns_tsec_t *	tsec,
		unsigned int	options
	)

Destroy DNS request transaction state identified by '*transp'.

Requires:

'*transp' is a valid transaction ID.

The caller has received the CLIENTREQDONE event (either because the request completed or because dns_client_cancelrequest() was called).

Ensures:

*transp == NULL.

Definition at line 2686 of file client.c.

References updatearg::actx, dns_client::actx, dns_client::attributes, updatearg::canceled, updatearg::client, DESTROYLOCK, dns_client_cancelupdate(), dns_client_startupdate(), DNS_CLIENT_VALID, DNS_CLIENTATTR_OWNCTX, DNS_CLIENTUPDOPT_ALLOWRUN, internal_update_callback(), isc_app_ctxrun(), ISC_FALSE, isc_mem_get, isc_mem_put, isc_mutex_init, ISC_R_FAILURE, ISC_R_NOMEMORY, ISC_R_NOTIMPLEMENTED, ISC_R_SUCCESS, ISC_R_SUSPEND, ISC_TRUE, LOCK, updatearg::lock, dns_client::mctx, REQUIRE, updatearg::result, dns_client::task, updatearg::trans, and UNLOCK.

isc_result_t dns_client_startupdate	(	dns_client_t *	client,
		dns_rdataclass_t	rdclass,
		dns_name_t *	zonename,
		dns_namelist_t *	prerequisites,
		dns_namelist_t *	updates,
		isc_sockaddrlist_t *	servers,
		dns_tsec_t *	tsec,
		unsigned int	options,
		isc_task_t *	task,
		isc_taskaction_t	action,
		void *	arg,
		dns_clientupdatetrans_t **	transp
	)

Perform DNS dynamic update for 'updates' of the 'rdclass' class with optional 'prerequisites'.

'updates' are a list of names with associated RRsets to be updated.

'prerequisites' are a list of names with associated RRsets corresponding to the prerequisites of the updates. This is optional and can be NULL, in which case the prerequisite section of the update message will be empty.

Both 'updates' and 'prerequisites' must be constructed as specified in RFC2136.

'zonename' is the name of the zone in which the updated names exist. This is optional and can be NULL. In this case, these functions internally identify the appropriate zone through some queries for the SOA RR starting with the first name in prerequisites or updates.

'servers' is a list of authoritative servers to which the update message should be sent. This is optional and can be NULL. In this case, these functions internally identify the appropriate primary server name and its addresses through some queries for the SOA RR (like the case of zonename) and supplemental A/AAAA queries for the server name. Note: The client module generally assumes the given addresses are of the primary server of the corresponding zone. It will work even if a secondary server address is specified as long as the server allows update forwarding, it is generally discouraged to include secondary server addresses unless there's strong reason to do so.

'tsec' is a transaction security object containing, e.g. a TSIG key for authenticating the update transaction (and the supplemental query/response transactions if the server is specified). This is optional and can be NULL, in which case the library tries the update without any transaction authentication.

It is typically expected that the client object passed to dns_client_update() was created via dns_client_create() and has its own managers and contexts. However, if the DNS_CLIENTUPDOPT_ALLOWRUN flag is set in 'options', this function performs the synchronous service even if it does not have its own manager and context structures.

dns_client_update() provides a synchronous service. This function blocks until the entire update procedure completes, including the additional queries when necessary.

dns_client_startupdate() is an asynchronous version of dns_client_update(). It immediately returns (typically with *transp being set to a non-NULL pointer), and performs the update procedure through a set of internal events. All transactions including the additional query exchanges are performed as a separate event, so none of these events cause blocking operation. When the update procedure completes, the specified function 'action' will be called with the argument of a 'dns_clientupdateevent_t' structure. On return, '*transp' is set to an opaque transaction ID so that the caller can cancel this update process.

DNS_CLIENTUPDOPT_TCP switches to the TCP (vs. UDP) transport.

Requires:

'client' is a valid client.

'updates' != NULL.

'task' is a valid task.

'transp' != NULL && *transp == NULL;

Returns:

ISC_R_SUCCESS On success.

Anything else Failure.

Definition at line 2767 of file client.c.

References updatectx::bp4, updatectx::bp6, updatectx::canceled, updatectx::client, copy_name(), updatectx::currentserver, DESTROYLOCK, dns_client_startresolve(), DNS_CLIENT_VALID, DNS_CLIENTRESOPT_TCP, dns_clientupdatestate_prepare, DNS_CLIENTUPDOPT_TCP, DNS_CLIENTVIEW_NAME, DNS_EVENT_UPDATEDONE, dns_fixedname_init, dns_fixedname_name, dns_message_addname(), dns_message_create(), dns_message_currentname(), dns_message_destroy(), dns_message_firstname(), DNS_MESSAGE_INTENTRENDER, dns_name_clone(), dns_name_copy(), dns_name_init(), dns_opcode_update, DNS_SECTION_PREREQUISITE, DNS_SECTION_UPDATE, dns_tsec_getkey(), dns_tsec_gettype(), dns_tsectype_none, dns_tsectype_tsig, dns_tsigkey_detach(), dns_view_detach(), dns_viewlist_find(), updatectx::event, updatectx::firstname, isc_event_allocate(), isc_event_free(), ISC_EVENT_PTR, ISC_FALSE, ISC_LINK_INIT, ISC_LINK_LINKED, ISC_LIST_APPEND, ISC_LIST_HEAD, ISC_LIST_INIT, ISC_LIST_NEXT, ISC_LIST_UNLINK, isc_mem_get, isc_mem_put, isc_mutex_init, ISC_R_NOMEMORY, ISC_R_NOMORE, ISC_R_NOTIMPLEMENTED, ISC_R_SUCCESS, isc_task_attach(), isc_task_detach(), ISC_TF, isc_sockaddr::length, updatectx::lock, dns_client::lock, LOCK, updatectx::magic, dns_client::mctx, name, updatectx::nservers, dns_message::opcode, updatectx::rdclass, request_soa(), REQUIRE, resolvesoa_done(), updatectx::restrans, updatectx::restrans2, send_update(), updatectx::servers, updatectx::sig0key, updatectx::soaqname, updatectx::soaquery, updatectx::soareq, updatectx::state, dns_client::task, updatectx::tsigkey, isc_sockaddr::type, UCTX_MAGIC, UNLOCK, UNUSED, updatectx::updatemsg, updatectx::updatereq, updatectx::view, dns_client::viewlist, updatectx::want_tcp, updatectx::zonefname, and updatectx::zonename.

Referenced by dns_client_update().

void dns_client_cancelupdate ( dns_clientupdatetrans_t * trans )

Cancel an ongoing dynamic update procedure started via dns_client_startupdate().

Notes:

If the update procedure has not completed, post its UPDATEDONE event with a result code of ISC_R_CANCELED.

Requires:

'trans' is a valid transaction ID.

Definition at line 2971 of file client.c.

References updatectx::canceled, dns_client_cancelresolve(), dns_request_cancel(), ISC_TRUE, updatectx::lock, LOCK, REQUIRE, updatectx::restrans, updatectx::restrans2, updatectx::soareq, UCTX_VALID, UNLOCK, and updatectx::updatereq.

Referenced by dns_client_update().

void dns_client_destroyupdatetrans ( dns_clientupdatetrans_t ** transp )

Destroy dynamic update transaction identified by '*transp'.

Requires:

'*transp' is a valid transaction ID.

The caller has received the UPDATEDONE event (either because the update completed or because dns_client_cancelupdate() was called).

Ensures:

*transp == NULL.

Definition at line 2996 of file client.c.

References updatectx::client, destroyclient(), DESTROYLOCK, DNS_CLIENT_VALID, dns_view_detach(), updatectx::event, INSIST, ISC_FALSE, ISC_LINK_LINKED, ISC_LIST_EMPTY, ISC_LIST_HEAD, ISC_LIST_UNLINK, isc_mem_put, ISC_TRUE, updatectx::lock, dns_client::lock, LOCK, updatectx::magic, dns_client::mctx, dns_client::references, REQUIRE, updatectx::servers, updatectx::sig0key, updatectx::soaquery, updatectx::soareq, updatectx::tsigkey, UCTX_VALID, UNLOCK, updatectx::updatemsg, updatectx::updatereq, and updatectx::view.

Referenced by internal_update_callback().

isc_result_t dns_client_updaterec	(	dns_client_updateop_t	op,
		dns_name_t *	owner,
		dns_rdatatype_t	type,
		dns_rdata_t *	source,
		dns_ttl_t	ttl,
		dns_name_t *	target,
		dns_rdataset_t *	rdataset,
		dns_rdatalist_t *	rdatalist,
		dns_rdata_t *	rdata,
		isc_mem_t *	mctx
	)

TBD.

Definition at line 3061 of file client.c.

References dns_name::attributes, dns_client_updaterec_t::buffer, dns_rdatalist::covers, dns_rdata::data, dns_client_updaterec_t::data, dns_name_copy(), dns_name_setbuffer(), DNS_NAMEATTR_HASUPDATEREC, DNS_NAMEATTR_PREREQUISITE, DNS_NAMEATTR_UPDATE, dns_rdata_clone(), dns_rdata_covers(), dns_rdata_deleterrset(), dns_rdata_exists(), dns_rdata_init(), dns_rdata_makedelete(), dns_rdata_notexist(), dns_rdata_toregion(), dns_rdatalist_init(), dns_rdatalist_tordataset(), dns_rdataset_init(), INSIST, isc_buffer_copyregion(), isc_buffer_init, isc_buffer_used, ISC_LIST_APPEND, isc_mem_attach(), isc_mem_get, ISC_R_NOMEMORY, ISC_R_SUCCESS, dns_rdata::length, dns_name::length, dns_client_updaterec_t::mctx, r, dns_client_updaterec_t::rdata, dns_client_updaterec_t::rdatalist, dns_client_updaterec_t::rdataset, dns_rdata::rdclass, dns_rdatalist::rdclass, REQUIRE, dns_rdatalist::ttl, dns_rdatalist::type, dns_rdata::type, updateop_add, updateop_delete, updateop_exist, updateop_max, updateop_none, and updateop_notexist.

void dns_client_freeupdate ( dns_name_t ** namep )

TBD.

Definition at line 3159 of file client.c.

References dns_name::attributes, dns_name::buffer, DNS_NAMEATTR_HASUPDATEREC, dns_rdatalist_fromrdataset(), dns_rdataset_disassociate(), INSIST, ISC_LIST_HEAD, ISC_LIST_UNLINK, isc_mem_putanddetach, dns_client_updaterec_t::mctx, name, REQUIRE, and dns_client_updaterec_t::size.

isc_mem_t* dns_client_mctx ( dns_client_t * client )

Definition at line 3044 of file client.c.

References DNS_CLIENT_VALID, dns_client::mctx, and REQUIRE.

Generated on Tue Apr 28 17:41:09 2015 by Doxygen 1.5.4 for BIND9 Internals 9.11.0pre-alpha


Data Structures
struct	dns_clientresevent
	A dns_clientresevent_t is sent when name resolution performed by a client completes. 'result' stores the result code of the entire resolution procedure. 'vresult' specifically stores the result code of DNSSEC validation if it is performed. When name resolution successfully completes, 'answerlist' is typically non empty, containing answer names along with RRsets. It is the receiver's responsibility to free this list by calling dns_client_freeresanswer() before freeing the event structure. More...
struct	dns_clientreqevent
	A dns_clientreqevent_t is sent when a DNS request is completed by a client. 'result' stores the result code of the entire transaction. If the transaction is successfully completed but the response packet cannot be parsed, 'result' will store the result code of dns_message_parse(). If the response packet is received, 'rmessage' will contain the response message, whether it is successfully parsed or not. More...
struct	dns_clientupdateevent
	A dns_clientupdateevent_t is sent when dynamic update performed by a client completes. 'result' stores the result code of the entire update procedure. 'state' specifies the status of the update procedure when this event is sent. This can be used as a hint by the receiver to determine whether the update attempt was ever made. In particular, if the state is dns_clientupdatestate_prepare, the receiver can be sure that the requested update was not applied. More...
Defines
#define	DNS_CLIENT_H 1
#define	DNS_CLIENTCREATEOPT_USECACHE 0x8000
	Optional flags for dns_client_create(x).
#define	DNS_CLIENTRESOPT_NODNSSEC 0x01
	Optional flags for dns_client_(start)resolve.
#define	DNS_CLIENTRESOPT_ALLOWRUN 0x02
	Don't validate responses.
#define	DNS_CLIENTRESOPT_NOVALIDATE 0x04
	Don't set the CD flag on upstream queries.
#define	DNS_CLIENTRESOPT_NOCDFLAG 0x08
	Use TCP transport.
#define	DNS_CLIENTRESOPT_TCP 0x10
#define	DNS_CLIENTREQOPT_ALLOWRUN 0x01
	Optional flags for dns_client_(start)request.
#define	DNS_CLIENTREQOPT_TCP 0x02
#define	DNS_CLIENTUPDOPT_ALLOWRUN 0x01
	Optional flags for dns_client_(start)update.
#define	DNS_CLIENTUPDOPT_TCP 0x02
Typedefs
typedef struct dns_clientresevent	dns_clientresevent_t
typedef struct dns_clientreqevent	dns_clientreqevent_t
typedef struct dns_clientupdateevent	dns_clientupdateevent_t
Enumerations
enum	dns_client_updateop_t { updateop_none = 0, updateop_add = 1, updateop_delete = 2, updateop_exist = 3, updateop_notexist = 4, updateop_max = 5 }
enum	dns_clientupdatestate_t { dns_clientupdatestate_prepare, dns_clientupdatestate_sent, dns_clientupdatestate_done }
	Status of a dynamic update procedure. More...
Functions
isc_result_t	dns_client_create (dns_client_t **clientp, unsigned int options)
isc_result_t	dns_client_createx (isc_mem_t mctx, isc_appctx_t actx, isc_taskmgr_t taskmgr, isc_socketmgr_t socketmgr, isc_timermgr_t timermgr, unsigned int options, dns_client_t *clientp)
isc_result_t	dns_client_createx2 (isc_mem_t mctx, isc_appctx_t actx, isc_taskmgr_t taskmgr, isc_socketmgr_t socketmgr, isc_timermgr_t timermgr, unsigned int options, dns_client_t clientp, isc_sockaddr_t localaddr4, isc_sockaddr_t *localaddr6)
	Create a DNS client. These functions create a new client object with minimal internal resources such as the default 'view' for the IN class and IPv4/IPv6 dispatches for the view.
void	dns_client_destroy (dns_client_t **clientp)
	Destroy 'client'.
isc_result_t	dns_client_setservers (dns_client_t client, dns_rdataclass_t rdclass, dns_name_t namespace, isc_sockaddrlist_t *addrs)
	Specify a list of addresses of recursive name servers that the client will use for name resolution. A view for the 'rdclass' class must be created beforehand. If 'namespace' is non NULL, the specified server will be used if and only if the query name is a subdomain of 'namespace'. When servers for multiple 'namespace's are provided, and a query name is covered by more than one 'namespace', the servers for the best (longest) matching namespace will be used. If 'namespace' is NULL, it works as if dns_rootname (.) were specified.
isc_result_t	dns_client_clearservers (dns_client_t client, dns_rdataclass_t rdclass, dns_name_t namespace)
	Remove configured recursive name servers for the 'rdclass' and 'namespace' from the client. See the description of dns_client_setservers() for the requirements about 'rdclass' and 'namespace'.
isc_result_t	dns_client_setdlv (dns_client_t client, dns_rdataclass_t rdclass, const char dlvname)
	Specify a name to use for DNSSEC lookaside validation (e.g., "dlv.isc.org"). If a trusted key has been added for that name, then DLV will be used during validation. If 'dlvname' is NULL, then DLV will no longer be used for this client.
isc_result_t	dns_client_resolve (dns_client_t client, dns_name_t name, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int options, dns_namelist_t *namelist)
isc_result_t	dns_client_startresolve (dns_client_t client, dns_name_t name, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int options, isc_task_t task, isc_taskaction_t action, void arg, dns_clientrestrans_t **transp)
	Perform name resolution for 'name', 'rdclass', and 'type'.
void	dns_client_cancelresolve (dns_clientrestrans_t *trans)
	Cancel an ongoing resolution procedure started via dns_client_startresolve().
void	dns_client_destroyrestrans (dns_clientrestrans_t **transp)
	Destroy name resolution transaction state identified by '*transp'.
void	dns_client_freeresanswer (dns_client_t client, dns_namelist_t namelist)
	Free resources allocated for the content of 'namelist'.
isc_result_t	dns_client_addtrustedkey (dns_client_t client, dns_rdataclass_t rdclass, dns_name_t keyname, isc_buffer_t *keydatabuf)
	Add a DNSSEC trusted key for the 'rdclass' class. A view for the 'rdclass' class must be created beforehand. 'keyname' is the DNS name of the key, and 'keydatabuf' stores the resource data of the key.
isc_result_t	dns_client_request (dns_client_t client, dns_message_t qmessage, dns_message_t rmessage, isc_sockaddr_t server, unsigned int options, unsigned int parseoptions, dns_tsec_t *tsec, unsigned int timeout, unsigned int udptimeout, unsigned int udpretries)
isc_result_t	dns_client_startrequest (dns_client_t client, dns_message_t qmessage, dns_message_t rmessage, isc_sockaddr_t server, unsigned int options, unsigned int parseoptions, dns_tsec_t tsec, unsigned int timeout, unsigned int udptimeout, unsigned int udpretries, isc_task_t task, isc_taskaction_t action, void arg, dns_clientreqtrans_t *transp)
	Send a DNS request containig a query message 'query' to 'server'.
void	dns_client_cancelrequest (dns_clientreqtrans_t *transp)
	Cancel an ongoing DNS request procedure started via dns_client_startrequest().
void	dns_client_destroyreqtrans (dns_clientreqtrans_t **transp)
isc_result_t	dns_client_update (dns_client_t client, dns_rdataclass_t rdclass, dns_name_t zonename, dns_namelist_t prerequisites, dns_namelist_t updates, isc_sockaddrlist_t servers, dns_tsec_t tsec, unsigned int options)
	Destroy DNS request transaction state identified by '*transp'.
isc_result_t	dns_client_startupdate (dns_client_t client, dns_rdataclass_t rdclass, dns_name_t zonename, dns_namelist_t prerequisites, dns_namelist_t updates, isc_sockaddrlist_t servers, dns_tsec_t tsec, unsigned int options, isc_task_t task, isc_taskaction_t action, void arg, dns_clientupdatetrans_t **transp)
	Perform DNS dynamic update for 'updates' of the 'rdclass' class with optional 'prerequisites'.
void	dns_client_cancelupdate (dns_clientupdatetrans_t *trans)
	Cancel an ongoing dynamic update procedure started via dns_client_startupdate().
void	dns_client_destroyupdatetrans (dns_clientupdatetrans_t **transp)
	Destroy dynamic update transaction identified by '*transp'.
isc_result_t	dns_client_updaterec (dns_client_updateop_t op, dns_name_t owner, dns_rdatatype_t type, dns_rdata_t source, dns_ttl_t ttl, dns_name_t target, dns_rdataset_t rdataset, dns_rdatalist_t rdatalist, dns_rdata_t rdata, isc_mem_t *mctx)
	TBD.
void	dns_client_freeupdate (dns_name_t **namep)
	TBD.
isc_mem_t *	dns_client_mctx (dns_client_t *client)