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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 
62 int
getrrsetbyname(const char * hostname,unsigned int rdclass,unsigned int rdtype,unsigned int flags,struct rrsetinfo ** res)63 getrrsetbyname(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 
240 fail:
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 
252 void
freerrset(struct rrsetinfo * rrset)253 freerrset(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