1/* $OpenBSD: getrrsetbyname.c,v 1.10 2005/03/30 02:58:28 tedu Exp $ */
2
3/*
4 * Copyright (c) 2007 Simon Vallet / Genoscope <svallet@genoscope.cns.fr>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/*
30 * Portions Copyright (c) 1999-2001 Internet Software Consortium.
31 *
32 * Permission to use, copy, modify, and distribute this software for any
33 * purpose with or without fee is hereby granted, provided that the above
34 * copyright notice and this permission notice appear in all copies.
35 *
36 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
37 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
39 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
40 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
41 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
42 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
43 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
44 */
45
46#include "includes.h"
47
48#if !defined (HAVE_GETRRSETBYNAME) && defined (HAVE_LDNS)
49
50#include <stdlib.h>
51#include <string.h>
52
53#include <ldns/ldns.h>
54
55#include "getrrsetbyname.h"
56#include "log.h"
57#include "xmalloc.h"
58
59#define malloc(x)	(xmalloc(x))
60#define calloc(x, y)	(xcalloc((x),(y)))
61
62int
63getrrsetbyname(const char *hostname, unsigned int rdclass,
64	       unsigned int rdtype, unsigned int flags,
65	       struct rrsetinfo **res)
66{
67	int result;
68	unsigned int i, j, index_ans, index_sig;
69	struct rrsetinfo *rrset = NULL;
70	struct rdatainfo *rdata;
71	size_t len;
72	ldns_resolver *ldns_res = NULL;
73	ldns_rdf *domain = NULL;
74	ldns_pkt *pkt = NULL;
75	ldns_rr_list *rrsigs = NULL, *rrdata = NULL;
76	ldns_status err;
77	ldns_rr *rr;
78
79	/* check for invalid class and type */
80	if (rdclass > 0xffff || rdtype > 0xffff) {
81		result = ERRSET_INVAL;
82		goto fail;
83	}
84
85	/* don't allow queries of class or type ANY */
86	if (rdclass == 0xff || rdtype == 0xff) {
87		result = ERRSET_INVAL;
88		goto fail;
89	}
90
91	/* don't allow flags yet, unimplemented */
92	if (flags) {
93		result = ERRSET_INVAL;
94		goto fail;
95	}
96
97	/* Initialize resolver from resolv.conf */
98	domain = ldns_dname_new_frm_str(hostname);
99	if ((err = ldns_resolver_new_frm_file(&ldns_res, NULL)) != \
100	    LDNS_STATUS_OK) {
101		result = ERRSET_FAIL;
102		goto fail;
103	}
104
105#ifdef LDNS_DEBUG
106	ldns_resolver_set_debug(ldns_res, true);
107#endif /* LDNS_DEBUG */
108
109	ldns_resolver_set_dnssec(ldns_res, true); /* Use DNSSEC */
110
111	/* make query */
112	pkt = ldns_resolver_query(ldns_res, domain, rdtype, rdclass, LDNS_RD);
113
114	/*** TODO: finer errcodes -- see original **/
115	if (!pkt || ldns_pkt_ancount(pkt) < 1) {
116		result = ERRSET_FAIL;
117		goto fail;
118	}
119
120	/* initialize rrset */
121	rrset = calloc(1, sizeof(struct rrsetinfo));
122	if (rrset == NULL) {
123		result = ERRSET_NOMEMORY;
124		goto fail;
125	}
126
127	rrdata = ldns_pkt_rr_list_by_type(pkt, rdtype, LDNS_SECTION_ANSWER);
128	rrset->rri_nrdatas = ldns_rr_list_rr_count(rrdata);
129	if (!rrset->rri_nrdatas) {
130		result = ERRSET_NODATA;
131		goto fail;
132	}
133
134	/* copy name from answer section */
135	len = ldns_rdf_size(ldns_rr_owner(ldns_rr_list_rr(rrdata, 0)));
136	if ((rrset->rri_name = malloc(len)) == NULL) {
137		result = ERRSET_NOMEMORY;
138		goto fail;
139	}
140	memcpy(rrset->rri_name,
141	    ldns_rdf_data(ldns_rr_owner(ldns_rr_list_rr(rrdata, 0))), len);
142
143	rrset->rri_rdclass = ldns_rr_get_class(ldns_rr_list_rr(rrdata, 0));
144	rrset->rri_rdtype = ldns_rr_get_type(ldns_rr_list_rr(rrdata, 0));
145	rrset->rri_ttl = ldns_rr_ttl(ldns_rr_list_rr(rrdata, 0));
146
147	debug2("ldns: got %u answers from DNS", rrset->rri_nrdatas);
148
149	/* Check for authenticated data */
150	if (ldns_pkt_ad(pkt)) {
151		rrset->rri_flags |= RRSET_VALIDATED;
152	} else { /* AD is not set, try autonomous validation */
153		ldns_rr_list * trusted_keys = ldns_rr_list_new();
154
155		debug2("ldns: trying to validate RRset");
156		/* Get eventual sigs */
157		rrsigs = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_RRSIG,
158		    LDNS_SECTION_ANSWER);
159
160		rrset->rri_nsigs = ldns_rr_list_rr_count(rrsigs);
161		debug2("ldns: got %u signature(s) (RRTYPE %u) from DNS",
162		       rrset->rri_nsigs, LDNS_RR_TYPE_RRSIG);
163
164		if ((err = ldns_verify_trusted(ldns_res, rrdata, rrsigs,
165		     trusted_keys)) == LDNS_STATUS_OK) {
166			rrset->rri_flags |= RRSET_VALIDATED;
167			debug2("ldns: RRset is signed with a valid key");
168		} else {
169			debug2("ldns: RRset validation failed: %s",
170			    ldns_get_errorstr_by_id(err));
171		}
172
173		ldns_rr_list_deep_free(trusted_keys);
174	}
175
176	/* allocate memory for answers */
177	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
178	   sizeof(struct rdatainfo));
179
180	if (rrset->rri_rdatas == NULL) {
181		result = ERRSET_NOMEMORY;
182		goto fail;
183	}
184
185	/* allocate memory for signatures */
186	if (rrset->rri_nsigs > 0) {
187		rrset->rri_sigs = calloc(rrset->rri_nsigs,
188		    sizeof(struct rdatainfo));
189
190		if (rrset->rri_sigs == NULL) {
191			result = ERRSET_NOMEMORY;
192			goto fail;
193		}
194	}
195
196	/* copy answers & signatures */
197	for (i=0, index_ans=0, index_sig=0; i< pkt->_header->_ancount; i++) {
198		rdata = NULL;
199		rr = ldns_rr_list_rr(ldns_pkt_answer(pkt), i);
200
201		if (ldns_rr_get_class(rr) == rrset->rri_rdclass &&
202		    ldns_rr_get_type(rr) == rrset->rri_rdtype) {
203			rdata = &rrset->rri_rdatas[index_ans++];
204		}
205
206		if (rr->_rr_class == rrset->rri_rdclass &&
207		    rr->_rr_type == LDNS_RR_TYPE_RRSIG &&
208		    rrset->rri_sigs) {
209			rdata = &rrset->rri_sigs[index_sig++];
210		}
211
212		if (rdata) {
213			size_t rdata_offset = 0;
214
215			rdata->rdi_length = 0;
216			for (j=0; j< rr->_rd_count; j++) {
217				rdata->rdi_length +=
218				    ldns_rdf_size(ldns_rr_rdf(rr, j));
219			}
220
221			rdata->rdi_data = malloc(rdata->rdi_length);
222			if (rdata->rdi_data == NULL) {
223				result = ERRSET_NOMEMORY;
224				goto fail;
225			}
226
227			/* Re-create the raw DNS RDATA */
228			for (j=0; j< rr->_rd_count; j++) {
229				len = ldns_rdf_size(ldns_rr_rdf(rr, j));
230				memcpy(rdata->rdi_data + rdata_offset,
231				       ldns_rdf_data(ldns_rr_rdf(rr, j)), len);
232				rdata_offset += len;
233			}
234		}
235	}
236
237	*res = rrset;
238	result = ERRSET_SUCCESS;
239
240fail:
241	/* freerrset(rrset); */
242	ldns_rdf_deep_free(domain);
243	ldns_pkt_free(pkt);
244	ldns_rr_list_deep_free(rrsigs);
245	ldns_rr_list_deep_free(rrdata);
246	ldns_resolver_deep_free(ldns_res);
247
248	return result;
249}
250
251
252void
253freerrset(struct rrsetinfo *rrset)
254{
255	u_int16_t i;
256
257	if (rrset == NULL)
258		return;
259
260	if (rrset->rri_rdatas) {
261		for (i = 0; i < rrset->rri_nrdatas; i++) {
262			if (rrset->rri_rdatas[i].rdi_data == NULL)
263				break;
264			free(rrset->rri_rdatas[i].rdi_data);
265		}
266		free(rrset->rri_rdatas);
267	}
268
269	if (rrset->rri_sigs) {
270		for (i = 0; i < rrset->rri_nsigs; i++) {
271			if (rrset->rri_sigs[i].rdi_data == NULL)
272				break;
273			free(rrset->rri_sigs[i].rdi_data);
274		}
275		free(rrset->rri_sigs);
276	}
277
278	if (rrset->rri_name)
279		free(rrset->rri_name);
280	free(rrset);
281}
282
283
284#endif /* !defined (HAVE_GETRRSETBYNAME) && defined (HAVE_LDNS) */
285