xref: /openbsd-src/usr.sbin/nsd/answer.c (revision 217deabe9c0353a6e19da5eca70e5a1b8b90b063)
1 /*
2  * answer.c -- manipulating query answers and encoding them.
3  *
4  * Copyright (c) 2001-2011, NLnet Labs. All rights reserved.
5  *
6  * See LICENSE for the license.
7  *
8  */
9 
10 #include <config.h>
11 
12 #include <string.h>
13 
14 #include "answer.h"
15 #include "packet.h"
16 #include "query.h"
17 
18 void
19 answer_init(answer_type *answer)
20 {
21 	answer->rrset_count = 0;
22 }
23 
24 int
25 answer_add_rrset(answer_type *answer, rr_section_type section,
26 		 domain_type *domain, rrset_type *rrset)
27 {
28 	size_t i;
29 
30 	assert(section >= ANSWER_SECTION && section < RR_SECTION_COUNT);
31 	assert(domain);
32 	assert(rrset);
33 
34 	/* Don't add an RRset multiple times.  */
35 	for (i = 0; i < answer->rrset_count; ++i) {
36 		if (answer->rrsets[i] == rrset) {
37 			if (section < answer->section[i]) {
38 				answer->section[i] = section;
39 				return 1;
40 			} else {
41 				return 0;
42 			}
43 		}
44 	}
45 
46 	if (answer->rrset_count >= MAXRRSPP) {
47 		/* XXX: Generate warning/error? */
48 		return 0;
49 	}
50 
51 	answer->section[answer->rrset_count] = section;
52 	answer->domains[answer->rrset_count] = domain;
53 	answer->rrsets[answer->rrset_count] = rrset;
54 	++answer->rrset_count;
55 
56 	return 1;
57 }
58 
59 void
60 encode_answer(query_type *q, const answer_type *answer)
61 {
62 	uint16_t counts[RR_SECTION_COUNT];
63 	rr_section_type section;
64 	size_t i;
65 
66 	for (section = ANSWER_SECTION; section < RR_SECTION_COUNT; ++section) {
67 		counts[section] = 0;
68 	}
69 
70 	for (section = ANSWER_SECTION;
71 	     !TC(q->packet) && section < RR_SECTION_COUNT;
72 	     ++section)
73 	{
74 		for (i = 0; !TC(q->packet) && i < answer->rrset_count; ++i) {
75 			if (answer->section[i] == section) {
76 				counts[section] += packet_encode_rrset(
77 					q,
78 					answer->domains[i],
79 					answer->rrsets[i],
80 					section);
81 			}
82 		}
83 	}
84 
85 	ANCOUNT_SET(q->packet, counts[ANSWER_SECTION]);
86 	NSCOUNT_SET(q->packet, counts[AUTHORITY_SECTION]);
87 	ARCOUNT_SET(q->packet,
88 		    counts[ADDITIONAL_A_SECTION]
89 		    + counts[ADDITIONAL_AAAA_SECTION]
90 		    + counts[ADDITIONAL_OTHER_SECTION]);
91 }
92