summaryrefslogtreecommitdiff
path: root/lib/dns/include/dns/lookup.h
blob: e825e00ba4e554cc4d1d90520d5ff18c55efc2ad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/*
 * Copyright (C) 2004-2007, 2009  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: lookup.h,v 1.14 2009/01/17 23:47:43 tbox Exp $ */

#ifndef DNS_LOOKUP_H
#define DNS_LOOKUP_H 1

/*****
 ***** Module Info
 *****/

/*! \file dns/lookup.h
 * \brief
 * The lookup module performs simple DNS lookups.  It implements
 * the full resolver algorithm, both looking for local data and
 * resolving external names as necessary.
 *
 * MP:
 *\li	The module ensures appropriate synchronization of data structures it
 *	creates and manipulates.
 *
 * Reliability:
 *\li	No anticipated impact.
 *
 * Resources:
 *\li	TBS
 *
 * Security:
 *\li	No anticipated impact.
 *
 * Standards:
 *\li	RFCs:	1034, 1035, 2181, TBS
 *\li	Drafts:	TBS
 */

#include <isc/lang.h>
#include <isc/event.h>

#include <dns/types.h>

ISC_LANG_BEGINDECLS

/*%
 * A 'dns_lookupevent_t' is returned when a lookup completes.
 * The sender field will be set to the lookup that completed.  If 'result'
 * is ISC_R_SUCCESS, then 'names' will contain a list of names associated
 * with the address.  The recipient of the event must not change the list
 * and must not refer to any of the name data after the event is freed.
 */
typedef struct dns_lookupevent {
	ISC_EVENT_COMMON(struct dns_lookupevent);
	isc_result_t			result;
	dns_name_t			*name;
	dns_rdataset_t			*rdataset;
	dns_rdataset_t			*sigrdataset;
	dns_db_t			*db;
	dns_dbnode_t			*node;
} dns_lookupevent_t;

isc_result_t
dns_lookup_create(isc_mem_t *mctx, dns_name_t *name, dns_rdatatype_t type,
		  dns_view_t *view, unsigned int options, isc_task_t *task,
		  isc_taskaction_t action, void *arg, dns_lookup_t **lookupp);
/*%<
 * Finds the rrsets matching 'name' and 'type'.
 *
 * Requires:
 *
 *\li	'mctx' is a valid mctx.
 *
 *\li	'name' is a valid name.
 *
 *\li	'view' is a valid view which has a resolver.
 *
 *\li	'task' is a valid task.
 *
 *\li	lookupp != NULL && *lookupp == NULL
 *
 * Returns:
 *
 *\li	ISC_R_SUCCESS
 *\li	ISC_R_NOMEMORY
 *
 *\li	Any resolver-related error (e.g. ISC_R_SHUTTINGDOWN) may also be
 *	returned.
 */

void
dns_lookup_cancel(dns_lookup_t *lookup);
/*%<
 * Cancel 'lookup'.
 *
 * Notes:
 *
 *\li	If 'lookup' has not completed, post its LOOKUPDONE event with a
 *	result code of ISC_R_CANCELED.
 *
 * Requires:
 *
 *\li	'lookup' is a valid lookup.
 */

void
dns_lookup_destroy(dns_lookup_t **lookupp);
/*%<
 * Destroy 'lookup'.
 *
 * Requires:
 *
 *\li	'*lookupp' is a valid lookup.
 *
 *\li	The caller has received the LOOKUPDONE event (either because the
 *	lookup completed or because dns_lookup_cancel() was called).
 *
 * Ensures:
 *
 *\li	*lookupp == NULL.
 */

ISC_LANG_ENDDECLS

#endif /* DNS_LOOKUP_H */