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 * 27 ldns_update_pkt_new(ldns_rdf *zone_rdf, ldns_rr_class c, 28 ldns_rr_list *pr_rrlist, ldns_rr_list *up_rrlist, 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 70 ldns_update_pkt_tsig_add(ldns_pkt *p, 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 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 continue; 118 /* [RFC1035 3.3.13] */ 119 *mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0)); 120 break; 121 } 122 ldns_pkt_free(resp); 123 124 return *mname ? LDNS_STATUS_OK : LDNS_STATUS_ERR; 125 } 126 127 /* Try to get zone and MNAME from SOA queries. */ 128 ldns_status 129 ldns_update_soa_zone_mname(const char *fqdn, ldns_resolver *r, 130 ldns_rr_class c, ldns_rdf **zone_rdf, ldns_rdf **mname_rdf) 131 { 132 ldns_rr *soa_rr, *rr; 133 ldns_rdf *soa_zone = NULL, *soa_mname = NULL; 134 ldns_rdf *ipaddr, *fqdn_rdf, *tmp; 135 ldns_rdf **nslist; 136 ldns_pkt *query, *resp; 137 size_t i; 138 139 /* 140 * XXX Ok, this cannot be the best way to find this...? 141 * XXX (I run into weird cache-related stuff here) 142 */ 143 144 /* Step 1 - first find a nameserver that should know *something* */ 145 fqdn_rdf = ldns_dname_new_frm_str(fqdn); 146 query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD); 147 if (!query) { 148 return LDNS_STATUS_ERR; 149 } 150 fqdn_rdf = NULL; 151 152 ldns_pkt_set_random_id(query); 153 if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) { 154 ldns_pkt_free(query); 155 return LDNS_STATUS_ERR; 156 } 157 ldns_pkt_free(query); 158 if (!resp) { 159 return LDNS_STATUS_ERR; 160 } 161 162 /* XXX Is it safe to only look in authority section here? */ 163 while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) { 164 if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA) 165 continue; 166 /* [RFC1035 3.3.13] */ 167 soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0)); 168 break; 169 } 170 ldns_pkt_free(resp); 171 if (!soa_rr) { 172 return LDNS_STATUS_ERR; 173 } 174 175 /* Step 2 - find SOA MNAME IP address, add to resolver */ 176 query = ldns_pkt_query_new(soa_mname, LDNS_RR_TYPE_A, c, LDNS_RD); 177 if (!query) { 178 return LDNS_STATUS_ERR; 179 } 180 soa_mname = NULL; 181 182 ldns_pkt_set_random_id(query); 183 if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) { 184 ldns_pkt_free(query); 185 return LDNS_STATUS_ERR; 186 } 187 ldns_pkt_free(query); 188 if (!resp) { 189 return LDNS_STATUS_ERR; 190 } 191 192 if (ldns_pkt_ancount(resp) == 0) { 193 ldns_pkt_free(resp); 194 return LDNS_STATUS_ERR; 195 } 196 197 /* XXX There may be more than one answer RR here. */ 198 rr = ldns_rr_list_pop_rr(ldns_pkt_answer(resp)); 199 ipaddr = ldns_rr_rdf(rr, 0); 200 201 /* Put the SOA mname IP first in the nameserver list. */ 202 nslist = ldns_resolver_nameservers(r); 203 for (i = 0; i < ldns_resolver_nameserver_count(r); i++) { 204 if (ldns_rdf_compare(ipaddr, nslist[i]) == 0) { 205 if (i) { 206 tmp = nslist[0]; 207 nslist[0] = nslist[i]; 208 nslist[i] = tmp; 209 } 210 break; 211 } 212 } 213 if (i >= ldns_resolver_nameserver_count(r)) { 214 /* SOA mname was not part of the resolver so add it first. */ 215 (void) ldns_resolver_push_nameserver(r, ipaddr); 216 nslist = ldns_resolver_nameservers(r); 217 i = ldns_resolver_nameserver_count(r) - 1; 218 tmp = nslist[0]; 219 nslist[0] = nslist[i]; 220 nslist[i] = tmp; 221 } 222 ldns_pkt_free(resp); 223 224 /* Make sure to ask the first in the list, i.e SOA mname */ 225 ldns_resolver_set_random(r, false); 226 227 /* Step 3 - Redo SOA query, sending to SOA MNAME directly. */ 228 fqdn_rdf = ldns_dname_new_frm_str(fqdn); 229 query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD); 230 if (!query) { 231 return LDNS_STATUS_ERR; 232 } 233 fqdn_rdf = NULL; 234 235 ldns_pkt_set_random_id(query); 236 if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) { 237 ldns_pkt_free(query); 238 return LDNS_STATUS_ERR; 239 } 240 ldns_pkt_free(query); 241 if (!resp) { 242 return LDNS_STATUS_ERR; 243 } 244 245 /* XXX Is it safe to only look in authority section here, too? */ 246 while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) { 247 if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA) 248 continue; 249 /* [RFC1035 3.3.13] */ 250 soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0)); 251 soa_zone = ldns_rdf_clone(ldns_rr_owner(soa_rr)); 252 break; 253 } 254 ldns_pkt_free(resp); 255 if (!soa_rr) { 256 return LDNS_STATUS_ERR; 257 } 258 259 /* That seems to have worked, pass results to caller. */ 260 *zone_rdf = soa_zone; 261 *mname_rdf = soa_mname; 262 return LDNS_STATUS_OK; 263 } 264 265 /* 266 * ldns_update_{get,set}_{zo,pr,up,ad}count 267 */ 268 269 uint16_t 270 ldns_update_zocount(const ldns_pkt *p) 271 { 272 return ldns_pkt_qdcount(p); 273 } 274 275 uint16_t 276 ldns_update_prcount(const ldns_pkt *p) 277 { 278 return ldns_pkt_ancount(p); 279 } 280 281 uint16_t 282 ldns_update_upcount(const ldns_pkt *p) 283 { 284 return ldns_pkt_nscount(p); 285 } 286 287 uint16_t 288 ldns_update_ad(const ldns_pkt *p) 289 { 290 return ldns_pkt_arcount(p); 291 } 292 293 void 294 ldns_update_set_zo(ldns_pkt *p, uint16_t v) 295 { 296 ldns_pkt_set_qdcount(p, v); 297 } 298 299 void 300 ldns_update_set_prcount(ldns_pkt *p, uint16_t v) 301 { 302 ldns_pkt_set_ancount(p, v); 303 } 304 305 void 306 ldns_update_set_upcount(ldns_pkt *p, uint16_t v) 307 { 308 ldns_pkt_set_nscount(p, v); 309 } 310 311 void 312 ldns_update_set_adcount(ldns_pkt *p, uint16_t v) 313 { 314 ldns_pkt_set_arcount(p, v); 315 } 316