1 /* update.c
2 *
3 * Functions for RFC 2136 Dynamic Update
4 *
5 * Copyright (c) 2005-2008, NLnet Labs. All rights reserved.
6 *
7 * See LICENSE for the license.
8 */
9
10 #include <ldns/config.h>
11
12 #include <ldns/ldns.h>
13
14 #include <strings.h>
15 #include <stdlib.h>
16 #include <limits.h>
17
18 /*
19 * RFC 2136 sections mapped to RFC 1035:
20 * zone/ZO -- QD/question
21 * prerequisites/PR -- AN/answers
22 * updates/UP -- NS/authority records
23 * additional data/AD -- AR/additional records
24 */
25
26 ldns_pkt *
ldns_update_pkt_new(ldns_rdf * zone_rdf,ldns_rr_class c,const ldns_rr_list * pr_rrlist,const ldns_rr_list * up_rrlist,const ldns_rr_list * ad_rrlist)27 ldns_update_pkt_new(ldns_rdf *zone_rdf, ldns_rr_class c,
28 const ldns_rr_list *pr_rrlist, const ldns_rr_list *up_rrlist, const ldns_rr_list *ad_rrlist)
29 {
30 ldns_pkt *p;
31
32 if (!zone_rdf || !up_rrlist) {
33 return NULL;
34 }
35
36 if (c == 0) {
37 c = LDNS_RR_CLASS_IN;
38 }
39
40 /* Create packet, fill in Zone Section. */
41 p = ldns_pkt_query_new(zone_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
42 if (!p) {
43 return NULL;
44 }
45 zone_rdf = NULL; /* No longer safe to use. */
46
47 ldns_pkt_set_opcode(p, LDNS_PACKET_UPDATE);
48
49 ldns_rr_list_deep_free(p->_authority);
50
51 ldns_pkt_set_authority(p, ldns_rr_list_clone(up_rrlist));
52
53 ldns_update_set_upcount(p, ldns_rr_list_rr_count(up_rrlist));
54
55 if (pr_rrlist) {
56 ldns_rr_list_deep_free(p->_answer); /*XXX access function */
57 ldns_pkt_set_answer(p, ldns_rr_list_clone(pr_rrlist));
58 ldns_update_set_prcount(p, ldns_rr_list_rr_count(pr_rrlist));
59 }
60
61 if (ad_rrlist) {
62 ldns_rr_list_deep_free(p->_additional);
63 ldns_pkt_set_additional(p, ldns_rr_list_clone(ad_rrlist));
64 ldns_update_set_adcount(p, ldns_rr_list_rr_count(ad_rrlist));
65 }
66 return p;
67 }
68
69 ldns_status
ldns_update_pkt_tsig_add(ldns_pkt * p,const ldns_resolver * r)70 ldns_update_pkt_tsig_add(ldns_pkt *p, const ldns_resolver *r)
71 {
72 #ifdef HAVE_SSL
73 uint16_t fudge = 300; /* Recommended fudge. [RFC2845 6.4] */
74 if (ldns_resolver_tsig_keyname(r) && ldns_resolver_tsig_keydata(r))
75 return ldns_pkt_tsig_sign(p, ldns_resolver_tsig_keyname(r),
76 ldns_resolver_tsig_keydata(r), fudge,
77 ldns_resolver_tsig_algorithm(r), NULL);
78 #else
79 /* do nothing */
80 (void)p;
81 (void)r;
82 #endif /* HAVE_SSL */
83 /* No TSIG to do. */
84 return LDNS_STATUS_OK;
85 }
86
87 /* Move to higher.c or similar? */
88 /* XXX doc */
89 ldns_status
ldns_update_soa_mname(ldns_rdf * zone,ldns_resolver * r,ldns_rr_class c,ldns_rdf ** mname)90 ldns_update_soa_mname(ldns_rdf *zone, ldns_resolver *r,
91 ldns_rr_class c, ldns_rdf **mname)
92 {
93 ldns_rr *soa_rr;
94 ldns_pkt *query, *resp;
95
96 /* Nondestructive, so clone 'zone' here */
97 query = ldns_pkt_query_new(ldns_rdf_clone(zone), LDNS_RR_TYPE_SOA,
98 c, LDNS_RD);
99 if (!query) {
100 return LDNS_STATUS_ERR;
101 }
102
103 ldns_pkt_set_random_id(query);
104 if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
105 ldns_pkt_free(query);
106 return LDNS_STATUS_ERR;
107 }
108 ldns_pkt_free(query);
109 if (!resp) {
110 return LDNS_STATUS_ERR;
111 }
112
113 /* Expect a SOA answer. */
114 *mname = NULL;
115 while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_answer(resp)))) {
116 if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
117 || ldns_rr_rdf(soa_rr, 0) == NULL)
118 continue;
119 /* [RFC1035 3.3.13] */
120 *mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
121 break;
122 }
123 ldns_pkt_free(resp);
124
125 return *mname ? LDNS_STATUS_OK : LDNS_STATUS_ERR;
126 }
127
128 /* Try to get zone and MNAME from SOA queries. */
129 ldns_status
ldns_update_soa_zone_mname(const char * fqdn,ldns_resolver * r,ldns_rr_class c,ldns_rdf ** zone_rdf,ldns_rdf ** mname_rdf)130 ldns_update_soa_zone_mname(const char *fqdn, ldns_resolver *r,
131 ldns_rr_class c, ldns_rdf **zone_rdf, ldns_rdf **mname_rdf)
132 {
133 ldns_rr *soa_rr, *rr;
134 ldns_rdf *soa_zone = NULL, *soa_mname = NULL;
135 ldns_rdf *ipaddr, *fqdn_rdf, *tmp;
136 ldns_rdf **nslist;
137 ldns_pkt *query, *resp;
138 ldns_resolver *tmp_r;
139 size_t i;
140
141 /*
142 * XXX Ok, this cannot be the best way to find this...?
143 * XXX (I run into weird cache-related stuff here)
144 */
145
146 /* Step 1 - first find a nameserver that should know *something* */
147 fqdn_rdf = ldns_dname_new_frm_str(fqdn);
148 query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
149 if (!query) {
150 return LDNS_STATUS_ERR;
151 }
152 fqdn_rdf = NULL;
153
154 ldns_pkt_set_random_id(query);
155 if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
156 ldns_pkt_free(query);
157 return LDNS_STATUS_ERR;
158 }
159 ldns_pkt_free(query);
160 if (!resp) {
161 return LDNS_STATUS_ERR;
162 }
163
164 /* XXX Is it safe to only look in authority section here? */
165 while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) {
166 if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
167 || ldns_rr_rdf(soa_rr, 0) == NULL)
168 continue;
169 /* [RFC1035 3.3.13] */
170 soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
171 break;
172 }
173 ldns_pkt_free(resp);
174 if (!soa_rr) {
175 return LDNS_STATUS_ERR;
176 }
177
178 /* Step 2 - find SOA MNAME IP address, add to resolver */
179 query = ldns_pkt_query_new(soa_mname, LDNS_RR_TYPE_A, c, LDNS_RD);
180 if (!query) {
181 return LDNS_STATUS_ERR;
182 }
183 soa_mname = NULL;
184
185 ldns_pkt_set_random_id(query);
186 if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
187 ldns_pkt_free(query);
188 return LDNS_STATUS_ERR;
189 }
190 ldns_pkt_free(query);
191 if (!resp) {
192 return LDNS_STATUS_ERR;
193 }
194
195 if (ldns_pkt_ancount(resp) == 0) {
196 ldns_pkt_free(resp);
197 return LDNS_STATUS_ERR;
198 }
199
200 /* XXX There may be more than one answer RR here. */
201 rr = ldns_rr_list_pop_rr(ldns_pkt_answer(resp));
202 ipaddr = ldns_rr_rdf(rr, 0);
203
204 /* Put the SOA mname IP first in the nameserver list. */
205 if (!(tmp_r = ldns_resolver_clone(r))) {
206 return LDNS_STATUS_MEM_ERR;
207 }
208 nslist = ldns_resolver_nameservers(tmp_r);
209 for (i = 0; i < ldns_resolver_nameserver_count(tmp_r); i++) {
210 if (ldns_rdf_compare(ipaddr, nslist[i]) == 0) {
211 if (i) {
212 tmp = nslist[0];
213 nslist[0] = nslist[i];
214 nslist[i] = tmp;
215 }
216 break;
217 }
218 }
219 if (i >= ldns_resolver_nameserver_count(tmp_r)) {
220 /* SOA mname was not part of the resolver so add it first. */
221 (void) ldns_resolver_push_nameserver(tmp_r, ipaddr);
222 nslist = ldns_resolver_nameservers(tmp_r);
223 i = ldns_resolver_nameserver_count(tmp_r) - 1;
224 tmp = nslist[0];
225 nslist[0] = nslist[i];
226 nslist[i] = tmp;
227 }
228 ldns_pkt_free(resp);
229
230 /* Make sure to ask the first in the list, i.e SOA mname */
231 ldns_resolver_set_random(tmp_r, false);
232
233 /* Step 3 - Redo SOA query, sending to SOA MNAME directly. */
234 fqdn_rdf = ldns_dname_new_frm_str(fqdn);
235 query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
236 if (!query) {
237 ldns_resolver_free(tmp_r);
238 return LDNS_STATUS_ERR;
239 }
240 fqdn_rdf = NULL;
241
242 ldns_pkt_set_random_id(query);
243 if (ldns_resolver_send_pkt(&resp, tmp_r, query) != LDNS_STATUS_OK) {
244 ldns_pkt_free(query);
245 ldns_resolver_free(tmp_r);
246 return LDNS_STATUS_ERR;
247 }
248 ldns_resolver_free(tmp_r);
249 ldns_pkt_free(query);
250 if (!resp) {
251 return LDNS_STATUS_ERR;
252 }
253
254 /* XXX Is it safe to only look in authority section here, too? */
255 while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) {
256 if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
257 || ldns_rr_rdf(soa_rr, 0) == NULL)
258 continue;
259 /* [RFC1035 3.3.13] */
260 soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
261 soa_zone = ldns_rdf_clone(ldns_rr_owner(soa_rr));
262 break;
263 }
264 ldns_pkt_free(resp);
265 if (!soa_rr) {
266 return LDNS_STATUS_ERR;
267 }
268
269 /* That seems to have worked, pass results to caller. */
270 *zone_rdf = soa_zone;
271 *mname_rdf = soa_mname;
272 return LDNS_STATUS_OK;
273 }
274
275 /*
276 * ldns_update_{get,set}_{zo,pr,up,ad}count
277 */
278
279 uint16_t
ldns_update_zocount(const ldns_pkt * p)280 ldns_update_zocount(const ldns_pkt *p)
281 {
282 return ldns_pkt_qdcount(p);
283 }
284
285 uint16_t
ldns_update_prcount(const ldns_pkt * p)286 ldns_update_prcount(const ldns_pkt *p)
287 {
288 return ldns_pkt_ancount(p);
289 }
290
291 uint16_t
ldns_update_upcount(const ldns_pkt * p)292 ldns_update_upcount(const ldns_pkt *p)
293 {
294 return ldns_pkt_nscount(p);
295 }
296
297 uint16_t
ldns_update_ad(const ldns_pkt * p)298 ldns_update_ad(const ldns_pkt *p)
299 {
300 return ldns_pkt_arcount(p);
301 }
302
303 void
ldns_update_set_zo(ldns_pkt * p,uint16_t v)304 ldns_update_set_zo(ldns_pkt *p, uint16_t v)
305 {
306 ldns_pkt_set_qdcount(p, v);
307 }
308
309 void
ldns_update_set_prcount(ldns_pkt * p,uint16_t v)310 ldns_update_set_prcount(ldns_pkt *p, uint16_t v)
311 {
312 ldns_pkt_set_ancount(p, v);
313 }
314
315 void
ldns_update_set_upcount(ldns_pkt * p,uint16_t v)316 ldns_update_set_upcount(ldns_pkt *p, uint16_t v)
317 {
318 ldns_pkt_set_nscount(p, v);
319 }
320
321 void
ldns_update_set_adcount(ldns_pkt * p,uint16_t v)322 ldns_update_set_adcount(ldns_pkt *p, uint16_t v)
323 {
324 ldns_pkt_set_arcount(p, v);
325 }
326