contrib/bind-9.2.4rc7/lib/dns/include/dns/lookup.h

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000, 2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: lookup.h,v 1.5.2.1 2004/03/09 06:11:17 marka Exp $ */
  19
  20 #ifndef DNS_LOOKUP_H
  21 #define DNS_LOOKUP_H 1
  22
  23 /*****
  24  ***** Module Info
  25  *****/
  26
  27 /*
  28  * DNS Lookup
  29  *
  30  * The lookup module performs simple DNS lookups.  It implements
  31  * the full resolver algorithm, both looking for local data and
  32  * resoving external names as necessary.
  33  *
  34  * MP:
  35  *      The module ensures appropriate synchronization of data structures it
  36  *      creates and manipulates.
  37  *
  38  * Reliability:
  39  *      No anticipated impact.
  40  *
  41  * Resources:
  42  *      <TBS>
  43  *
  44  * Security:
  45  *      No anticipated impact.
  46  *
  47  * Standards:
  48  *      RFCs:   1034, 1035, 2181, <TBS>
  49  *      Drafts: <TBS>
  50  */
  51
  52 #include <isc/lang.h>
  53 #include <isc/event.h>
  54
  55 #include <dns/types.h>
  56
  57 ISC_LANG_BEGINDECLS
  58
  59 /*
  60  * A 'dns_lookupevent_t' is returned when a lookup completes.
  61  * The sender field will be set to the lookup that completed.  If 'result'
  62  * is ISC_R_SUCCESS, then 'names' will contain a list of names associated
  63  * with the address.  The recipient of the event must not change the list
  64  * and must not refer to any of the name data after the event is freed.
  65  */
  66 typedef struct dns_lookupevent {
  67         ISC_EVENT_COMMON(struct dns_lookupevent);
  68         isc_result_t                    result;
  69         dns_name_t                      *name;
  70         dns_rdataset_t                  *rdataset;
  71         dns_rdataset_t                  *sigrdataset;
  72         dns_db_t                        *db;
  73         dns_dbnode_t                    *node;
  74 } dns_lookupevent_t;
  75
  76 isc_result_t
  77 dns_lookup_create(isc_mem_t *mctx, dns_name_t *name, dns_rdatatype_t type,
  78                   dns_view_t *view, unsigned int options, isc_task_t *task,
  79                   isc_taskaction_t action, void *arg, dns_lookup_t **lookupp);
  80 /*
  81  * Finds the rrsets matching 'name' and 'type'.
  82  *
  83  * Requires:
  84  *
  85  *      'mctx' is a valid mctx.
  86  *
  87  *      'name' is a valid name.
  88  *
  89  *      'view' is a valid view which has a resolver.
  90  *
  91  *      'task' is a valid task.
  92  *
  93  *      lookupp != NULL && *lookupp == NULL
  94  *
  95  * Returns:
  96  *
  97  *      ISC_R_SUCCESS
  98  *      ISC_R_NOMEMORY
  99  *
 100  *      Any resolver-related error (e.g. ISC_R_SHUTTINGDOWN) may also be
 101  *      returned.
 102  */
 103
 104 void
 105 dns_lookup_cancel(dns_lookup_t *lookup);
 106 /*
 107  * Cancel 'lookup'.
 108  *
 109  * Notes:
 110  *
 111  *      If 'lookup' has not completed, post its LOOKUPDONE event with a
 112  *      result code of ISC_R_CANCELED.
 113  *
 114  * Requires:
 115  *
 116  *      'lookup' is a valid lookup.
 117  */
 118
 119 void
 120 dns_lookup_destroy(dns_lookup_t **lookupp);
 121 /*
 122  * Destroy 'lookup'.
 123  *
 124  * Requires:
 125  *
 126  *      '*lookupp' is a valid lookup.
 127  *
 128  *      The caller has received the LOOKUPDONE event (either because the
 129  *      lookup completed or because dns_lookup_cancel() was called).
 130  *
 131  * Ensures:
 132  *
 133  *      *lookupp == NULL.
 134  */
 135
 136 ISC_LANG_ENDDECLS
 137
 138 #endif /* DNS_LOOKUP_H */