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#define free(x)		(xfree(x))
62
63int
64getrrsetbyname(const char *hostname, unsigned int rdclass,
65	       unsigned int rdtype, unsigned int flags,
66	       struct rrsetinfo **res)
67{
68	int result;
69	unsigned int i, j, index_ans, index_sig;
70	struct rrsetinfo *rrset = NULL;
71	struct rdatainfo *rdata;
72	size_t len;
73	ldns_resolver *ldns_res;
74	ldns_rdf *domain = NULL;
75	ldns_pkt *pkt = NULL;
76	ldns_rr_list *rrsigs = NULL, *rrdata = NULL;
77	ldns_status err;
78	ldns_rr *rr;
79
80	/* check for invalid class and type */
81	if (rdclass > 0xffff || rdtype > 0xffff) {
82		result = ERRSET_INVAL;
83		goto fail;
84	}
85
86	/* don't allow queries of class or type ANY */
87	if (rdclass == 0xff || rdtype == 0xff) {
88		result = ERRSET_INVAL;
89		goto fail;
90	}
91
92	/* don't allow flags yet, unimplemented */
93	if (flags) {
94		result = ERRSET_INVAL;
95		goto fail;
96	}
97
98	/* Initialize resolver from resolv.conf */
99	domain = ldns_dname_new_frm_str(hostname);
100	if ((err = ldns_resolver_new_frm_file(&ldns_res, NULL)) != \
101	    LDNS_STATUS_OK) {
102		result = ERRSET_FAIL;
103		goto fail;
104	}
105
106#ifdef LDNS_DEBUG
107	ldns_resolver_set_debug(ldns_res, true);
108#endif /* LDNS_DEBUG */
109
110	ldns_resolver_set_dnssec(ldns_res, true); /* Use DNSSEC */
111
112	/* make query */
113	pkt = ldns_resolver_query(ldns_res, domain, rdtype, rdclass, LDNS_RD);
114
115	/*** TODO: finer errcodes -- see original **/
116	if (!pkt || ldns_pkt_ancount(pkt) < 1) {
117		result = ERRSET_FAIL;
118		goto fail;
119	}
120
121	/* initialize rrset */
122	rrset = calloc(1, sizeof(struct rrsetinfo));
123	if (rrset == NULL) {
124		result = ERRSET_NOMEMORY;
125		goto fail;
126	}
127
128	rrdata = ldns_pkt_rr_list_by_type(pkt, rdtype, LDNS_SECTION_ANSWER);
129	rrset->rri_nrdatas = ldns_rr_list_rr_count(rrdata);
130	if (!rrset->rri_nrdatas) {
131		result = ERRSET_NODATA;
132		goto fail;
133	}
134
135	/* copy name from answer section */
136	len = ldns_rdf_size(ldns_rr_owner(ldns_rr_list_rr(rrdata, 0)));
137	if ((rrset->rri_name = malloc(len)) == NULL) {
138		result = ERRSET_NOMEMORY;
139		goto fail;
140	}
141	memcpy(rrset->rri_name,
142	    ldns_rdf_data(ldns_rr_owner(ldns_rr_list_rr(rrdata, 0))), len);
143
144	rrset->rri_rdclass = ldns_rr_get_class(ldns_rr_list_rr(rrdata, 0));
145	rrset->rri_rdtype = ldns_rr_get_type(ldns_rr_list_rr(rrdata, 0));
146	rrset->rri_ttl = ldns_rr_ttl(ldns_rr_list_rr(rrdata, 0));
147
148	debug2("ldns: got %u answers from DNS", rrset->rri_nrdatas);
149
150	/* Check for authenticated data */
151	if (ldns_pkt_ad(pkt)) {
152		rrset->rri_flags |= RRSET_VALIDATED;
153	} else { /* AD is not set, try autonomous validation */
154		ldns_rr_list * trusted_keys = ldns_rr_list_new();
155
156		debug2("ldns: trying to validate RRset");
157		/* Get eventual sigs */
158		rrsigs = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_RRSIG,
159		    LDNS_SECTION_ANSWER);
160
161		rrset->rri_nsigs = ldns_rr_list_rr_count(rrsigs);
162		debug2("ldns: got %u signature(s) (RRTYPE %u) from DNS",
163		       rrset->rri_nsigs, LDNS_RR_TYPE_RRSIG);
164
165		if ((err = ldns_verify_trusted(ldns_res, rrdata, rrsigs,
166		     trusted_keys)) == LDNS_STATUS_OK) {
167			rrset->rri_flags |= RRSET_VALIDATED;
168			debug2("ldns: RRset is signed with a valid key");
169		} else {
170			debug2("ldns: RRset validation failed: %s",
171			    ldns_get_errorstr_by_id(err));
172		}
173
174		ldns_rr_list_deep_free(trusted_keys);
175	}
176
177	/* allocate memory for answers */
178	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
179	   sizeof(struct rdatainfo));
180
181	if (rrset->rri_rdatas == NULL) {
182		result = ERRSET_NOMEMORY;
183		goto fail;
184	}
185
186	/* allocate memory for signatures */
187	if (rrset->rri_nsigs > 0) {
188		rrset->rri_sigs = calloc(rrset->rri_nsigs,
189		    sizeof(struct rdatainfo));
190
191		if (rrset->rri_sigs == NULL) {
192			result = ERRSET_NOMEMORY;
193			goto fail;
194		}
195	}
196
197	/* copy answers & signatures */
198	for (i=0, index_ans=0, index_sig=0; i< pkt->_header->_ancount; i++) {
199		rdata = NULL;
200		rr = ldns_rr_list_rr(ldns_pkt_answer(pkt), i);
201
202		if (ldns_rr_get_class(rr) == rrset->rri_rdclass &&
203		    ldns_rr_get_type(rr) == rrset->rri_rdtype) {
204			rdata = &rrset->rri_rdatas[index_ans++];
205		}
206
207		if (rr->_rr_class == rrset->rri_rdclass &&
208		    rr->_rr_type == LDNS_RR_TYPE_RRSIG &&
209		    rrset->rri_sigs) {
210			rdata = &rrset->rri_sigs[index_sig++];
211		}
212
213		if (rdata) {
214			size_t rdata_offset = 0;
215
216			rdata->rdi_length = 0;
217			for (j=0; j< rr->_rd_count; j++) {
218				rdata->rdi_length +=
219				    ldns_rdf_size(ldns_rr_rdf(rr, j));
220			}
221
222			rdata->rdi_data = malloc(rdata->rdi_length);
223			if (rdata->rdi_data == NULL) {
224				result = ERRSET_NOMEMORY;
225				goto fail;
226			}
227
228			/* Re-create the raw DNS RDATA */
229			for (j=0; j< rr->_rd_count; j++) {
230				len = ldns_rdf_size(ldns_rr_rdf(rr, j));
231				memcpy(rdata->rdi_data + rdata_offset,
232				       ldns_rdf_data(ldns_rr_rdf(rr, j)), len);
233				rdata_offset += len;
234			}
235		}
236	}
237
238	*res = rrset;
239	result = ERRSET_SUCCESS;
240
241fail:
242	/* freerrset(rrset); */
243	ldns_rdf_deep_free(domain);
244	ldns_pkt_free(pkt);
245	ldns_rr_list_deep_free(rrsigs);
246	ldns_rr_list_deep_free(rrdata);
247	ldns_resolver_deep_free(ldns_res);
248
249	return result;
250}
251
252
253void
254freerrset(struct rrsetinfo *rrset)
255{
256	u_int16_t i;
257
258	if (rrset == NULL)
259		return;
260
261	if (rrset->rri_rdatas) {
262		for (i = 0; i < rrset->rri_nrdatas; i++) {
263			if (rrset->rri_rdatas[i].rdi_data == NULL)
264				break;
265			free(rrset->rri_rdatas[i].rdi_data);
266		}
267		free(rrset->rri_rdatas);
268	}
269
270	if (rrset->rri_sigs) {
271		for (i = 0; i < rrset->rri_nsigs; i++) {
272			if (rrset->rri_sigs[i].rdi_data == NULL)
273				break;
274			free(rrset->rri_sigs[i].rdi_data);
275		}
276		free(rrset->rri_sigs);
277	}
278
279	if (rrset->rri_name)
280		free(rrset->rri_name);
281	free(rrset);
282}
283
284
285#endif /* !defined (HAVE_GETRRSETBYNAME) && defined (HAVE_LDNS) */
286