1/*
2 * Copyright (C) 2004, 2005, 2007, 2009  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000, 2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or 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: soa.c,v 1.12 2009/09/10 02:18:40 each Exp $ */
19
20/*! \file */
21
22#include <config.h>
23#include <string.h>
24
25#include <isc/buffer.h>
26#include <isc/util.h>
27
28#include <dns/rdata.h>
29#include <dns/rdatastruct.h>
30#include <dns/soa.h>
31
32static inline isc_uint32_t
33decode_uint32(unsigned char *p) {
34	return ((p[0] << 24) +
35		(p[1] << 16) +
36		(p[2] <<  8) +
37		(p[3] <<  0));
38}
39
40static inline void
41encode_uint32(isc_uint32_t val, unsigned char *p) {
42	p[0] = (isc_uint8_t)(val >> 24);
43	p[1] = (isc_uint8_t)(val >> 16);
44	p[2] = (isc_uint8_t)(val >>  8);
45	p[3] = (isc_uint8_t)(val >>  0);
46}
47
48static isc_uint32_t
49soa_get(dns_rdata_t *rdata, int offset) {
50	INSIST(rdata->type == dns_rdatatype_soa);
51	/*
52	 * Locate the field within the SOA RDATA based
53	 * on its position relative to the end of the data.
54	 *
55	 * This is a bit of a kludge, but the alternative approach of
56	 * using dns_rdata_tostruct() and dns_rdata_fromstruct() would
57	 * involve a lot of unnecessary work (like building domain
58	 * names and allocating temporary memory) when all we really
59	 * want to do is to get 32 bits of fixed-sized data.
60	 */
61	INSIST(rdata->length >= 20);
62	INSIST(offset >= 0 && offset <= 16);
63	return (decode_uint32(rdata->data + rdata->length - 20 + offset));
64}
65
66isc_result_t
67dns_soa_buildrdata(dns_name_t *origin, dns_name_t *contact,
68		   dns_rdataclass_t rdclass,
69		   isc_uint32_t serial, isc_uint32_t refresh,
70		   isc_uint32_t retry, isc_uint32_t expire,
71		   isc_uint32_t minimum, unsigned char *buffer,
72		   dns_rdata_t *rdata) {
73	dns_rdata_soa_t soa;
74	isc_buffer_t rdatabuf;
75
76	REQUIRE(origin != NULL);
77	REQUIRE(contact != NULL);
78
79	memset(buffer, 0, DNS_SOA_BUFFERSIZE);
80	isc_buffer_init(&rdatabuf, buffer, DNS_SOA_BUFFERSIZE);
81
82	soa.common.rdtype = dns_rdatatype_soa;
83	soa.common.rdclass = rdclass;
84	soa.mctx = NULL;
85	soa.serial = serial;
86	soa.refresh = refresh;
87	soa.retry = retry;
88	soa.expire = expire;
89	soa.minimum = minimum;
90	dns_name_init(&soa.origin, NULL);
91	dns_name_clone(origin, &soa.origin);
92	dns_name_init(&soa.contact, NULL);
93	dns_name_clone(contact, &soa.contact);
94
95	return (dns_rdata_fromstruct(rdata, rdclass, dns_rdatatype_soa,
96				      &soa, &rdatabuf));
97}
98
99isc_uint32_t
100dns_soa_getserial(dns_rdata_t *rdata) {
101	return soa_get(rdata, 0);
102}
103isc_uint32_t
104dns_soa_getrefresh(dns_rdata_t *rdata) {
105	return soa_get(rdata, 4);
106}
107isc_uint32_t
108dns_soa_getretry(dns_rdata_t *rdata) {
109	return soa_get(rdata, 8);
110}
111isc_uint32_t
112dns_soa_getexpire(dns_rdata_t *rdata) {
113	return soa_get(rdata, 12);
114}
115isc_uint32_t
116dns_soa_getminimum(dns_rdata_t *rdata) {
117	return soa_get(rdata, 16);
118}
119
120static void
121soa_set(dns_rdata_t *rdata, isc_uint32_t val, int offset) {
122	INSIST(rdata->type == dns_rdatatype_soa);
123	INSIST(rdata->length >= 20);
124	INSIST(offset >= 0 && offset <= 16);
125	encode_uint32(val, rdata->data + rdata->length - 20 + offset);
126}
127
128void
129dns_soa_setserial(isc_uint32_t val, dns_rdata_t *rdata) {
130	soa_set(rdata, val, 0);
131}
132void
133dns_soa_setrefresh(isc_uint32_t val, dns_rdata_t *rdata) {
134	soa_set(rdata, val, 4);
135}
136void
137dns_soa_setretry(isc_uint32_t val, dns_rdata_t *rdata) {
138	soa_set(rdata, val, 8);
139}
140void
141dns_soa_setexpire(isc_uint32_t val, dns_rdata_t *rdata) {
142	soa_set(rdata, val, 12);
143}
144void
145dns_soa_setminimum(isc_uint32_t val, dns_rdata_t *rdata) {
146	soa_set(rdata, val, 16);
147}
148