aaaa-filter-iterator.patch revision 356345
1Index: trunk/doc/unbound.conf.5.in 2=================================================================== 3--- trunk/doc/unbound.conf.5.in (revision 4357) 4+++ trunk/doc/unbound.conf.5.in (working copy) 5@@ -701,6 +701,13 @@ 6 this option in enabled. Only use if you know what you are doing. 7 This option only has effect when qname-minimisation is enabled. Default is off. 8 .TP 9+.B aaaa\-filter: \fI<yes or no> 10+Activate behavior similar to BIND's AAAA-filter. 11+This forces the dropping of all AAAA records, unless in the case of 12+explicit AAAA queries, when no A records have been confirmed. 13+This also causes an additional A query to be sent for each AAAA query. 14+This breaks DNSSEC! 15+.TP 16 .B private\-address: \fI<IP address or subnet> 17 Give IPv4 of IPv6 addresses or classless subnets. These are addresses 18 on your private network, and are not allowed to be returned for 19Index: trunk/iterator/iter_scrub.c 20=================================================================== 21--- trunk/iterator/iter_scrub.c (revision 4357) 22+++ trunk/iterator/iter_scrub.c (working copy) 23@@ -617,6 +617,32 @@ 24 } 25 26 /** 27+ * ASN: Lookup A records from rrset cache. 28+ * @param qinfo: the question originally asked. 29+ * @param env: module environment with config and cache. 30+ * @param ie: iterator environment with private address data. 31+ * @return 0 if no A record found, 1 if A record found. 32+ */ 33+static int 34+asn_lookup_a_record_from_cache(struct query_info* qinfo, 35+ struct module_env* env, struct iter_env* ATTR_UNUSED(ie)) 36+{ 37+ struct ub_packed_rrset_key* akey; 38+ 39+ /* get cached A records for queried name */ 40+ akey = rrset_cache_lookup(env->rrset_cache, qinfo->qname, 41+ qinfo->qname_len, LDNS_RR_TYPE_A, qinfo->qclass, 42+ 0, *env->now, 0); 43+ if(akey) { /* we had some. */ 44+ log_rrset_key(VERB_ALGO, "ASN-AAAA-filter: found A record", 45+ akey); 46+ lock_rw_unlock(&akey->entry.lock); 47+ return 1; 48+ } 49+ return 0; 50+} 51+ 52+/** 53 * Given a response event, remove suspect RRsets from the response. 54 * "Suspect" rrsets are potentially poison. Note that this routine expects 55 * the response to be in a "normalized" state -- that is, all "irrelevant" 56@@ -635,6 +661,7 @@ 57 struct query_info* qinfo, uint8_t* zonename, struct module_env* env, 58 struct iter_env* ie) 59 { 60+ int found_a_record = 0; /* ASN: do we have a A record? */ 61 int del_addi = 0; /* if additional-holding rrsets are deleted, we 62 do not trust the normalized additional-A-AAAA any more */ 63 struct rrset_parse* rrset, *prev; 64@@ -670,6 +697,13 @@ 65 rrset = rrset->rrset_all_next; 66 } 67 68+ /* ASN: Locate any A record we can find */ 69+ if((ie->aaaa_filter) && (qinfo->qtype == LDNS_RR_TYPE_AAAA)) { 70+ found_a_record = asn_lookup_a_record_from_cache(qinfo, 71+ env, ie); 72+ } 73+ /* ASN: End of added code */ 74+ 75 /* At this point, we brutally remove ALL rrsets that aren't 76 * children of the originating zone. The idea here is that, 77 * as far as we know, the server that we contacted is ONLY 78@@ -680,6 +714,24 @@ 79 prev = NULL; 80 rrset = msg->rrset_first; 81 while(rrset) { 82+ 83+ /* ASN: For AAAA records only... */ 84+ if((ie->aaaa_filter) && (rrset->type == LDNS_RR_TYPE_AAAA)) { 85+ /* ASN: If this is not a AAAA query, then remove AAAA 86+ * records, no questions asked. If this IS a AAAA query 87+ * then remove AAAA records if we have an A record. 88+ * Otherwise, leave things be. */ 89+ if((qinfo->qtype != LDNS_RR_TYPE_AAAA) || 90+ (found_a_record)) { 91+ remove_rrset("ASN-AAAA-filter: removing AAAA " 92+ "for record", pkt, msg, prev, &rrset); 93+ continue; 94+ } 95+ log_nametypeclass(VERB_ALGO, "ASN-AAAA-filter: " 96+ "keep AAAA for", zonename, 97+ LDNS_RR_TYPE_AAAA, qinfo->qclass); 98+ } 99+ /* ASN: End of added code */ 100 101 /* remove private addresses */ 102 if( (rrset->type == LDNS_RR_TYPE_A || 103Index: trunk/iterator/iter_utils.c 104=================================================================== 105--- trunk/iterator/iter_utils.c (revision 4357) 106+++ trunk/iterator/iter_utils.c (working copy) 107@@ -175,6 +175,7 @@ 108 } 109 iter_env->supports_ipv6 = cfg->do_ip6; 110 iter_env->supports_ipv4 = cfg->do_ip4; 111+ iter_env->aaaa_filter = cfg->aaaa_filter; 112 return 1; 113 } 114 115Index: trunk/iterator/iterator.c 116=================================================================== 117--- trunk/iterator/iterator.c (revision 4357) 118+++ trunk/iterator/iterator.c (working copy) 119@@ -1847,6 +1847,53 @@ 120 121 return 0; 122 } 123+ 124+/** 125+ * ASN: This event state was added as an intermediary step between 126+ * QUERYTARGETS_STATE and the next step, in order to cast a subquery for the 127+ * purpose of caching A records for the queried name. 128+ * 129+ * @param qstate: query state. 130+ * @param iq: iterator query state. 131+ * @param ie: iterator shared global environment. 132+ * @param id: module id. 133+ * @return true if the event requires more request processing immediately, 134+ * false if not. This state only returns true when it is generating 135+ * a SERVFAIL response because the query has hit a dead end. 136+ */ 137+static int 138+asn_processQueryAAAA(struct module_qstate* qstate, struct iter_qstate* iq, 139+ struct iter_env* ATTR_UNUSED(ie), int id) 140+{ 141+ struct module_qstate* subq = NULL; 142+ 143+ log_assert(iq->fetch_a_for_aaaa == 0); 144+ 145+ /* flag the query properly in order to not loop */ 146+ iq->fetch_a_for_aaaa = 1; 147+ 148+ /* re-throw same query, but with a different type */ 149+ if(!generate_sub_request(iq->qchase.qname, 150+ iq->qchase.qname_len, LDNS_RR_TYPE_A, 151+ iq->qchase.qclass, qstate, id, iq, 152+ INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1)) { 153+ log_nametypeclass(VERB_ALGO, "ASN-AAAA-filter: failed " 154+ "preloading of A record for", 155+ iq->qchase.qname, LDNS_RR_TYPE_A, 156+ iq->qchase.qclass); 157+ return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 158+ } 159+ log_nametypeclass(VERB_ALGO, "ASN-AAAA-filter: " 160+ "preloading records in cache for", 161+ iq->qchase.qname, LDNS_RR_TYPE_A, 162+ iq->qchase.qclass); 163+ 164+ /* set this query as waiting */ 165+ qstate->ext_state[id] = module_wait_subquery; 166+ /* at this point break loop */ 167+ return 0; 168+} 169+/* ASN: End of added code */ 170 171 /** 172 * This is the request event state where the request will be sent to one of 173@@ -1894,6 +1941,13 @@ 174 return error_response(qstate, id, LDNS_RCODE_SERVFAIL); 175 } 176 177+ /* ASN: If we have a AAAA query, then also query for A records */ 178+ if((ie->aaaa_filter) && (iq->qchase.qtype == LDNS_RR_TYPE_AAAA) && 179+ (iq->fetch_a_for_aaaa == 0)) { 180+ return next_state(iq, ASN_FETCH_A_FOR_AAAA_STATE); 181+ } 182+ /* ASN: End of added code */ 183+ 184 /* Make sure we have a delegation point, otherwise priming failed 185 * or another failure occurred */ 186 if(!iq->dp) { 187@@ -3095,6 +3149,61 @@ 188 return 0; 189 } 190 191+/** 192+ * ASN: Do final processing on responses to A queries originated from AAAA 193+ * queries. Events reach this state after the iterative resolution algorithm 194+ * terminates. 195+ * This is required down the road to decide whether to scrub AAAA records 196+ * from the results or not. 197+ * 198+ * @param qstate: query state. 199+ * @param id: module id. 200+ * @param forq: super query state. 201+ */ 202+static void 203+asn_processAAAAResponse(struct module_qstate* qstate, int id, 204+ struct module_qstate* super) 205+{ 206+ /*struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];*/ 207+ struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id]; 208+ struct delegpt_ns* dpns = NULL; 209+ int error = (qstate->return_rcode != LDNS_RCODE_NOERROR); 210+ 211+ log_assert(super_iq->fetch_a_for_aaaa > 0); 212+ 213+ /* let super go to evaluation of targets after this */ 214+ super_iq->state = QUERYTARGETS_STATE; 215+ 216+ log_query_info(VERB_ALGO, "ASN-AAAA-filter: processAAAAResponse", 217+ &qstate->qinfo); 218+ log_query_info(VERB_ALGO, "ASN-AAAA-filter: processAAAAResponse super", 219+ &super->qinfo); 220+ 221+ if(super_iq->dp) 222+ dpns = delegpt_find_ns(super_iq->dp, 223+ qstate->qinfo.qname, qstate->qinfo.qname_len); 224+ if (!dpns) { 225+ /* not interested */ 226+ verbose(VERB_ALGO, "ASN-AAAA-filter: subq: %s, but parent not " 227+ "interested%s", (error ? "error, but" : "success"), 228+ (super_iq->dp ? "anymore" : " (was reset)")); 229+ log_query_info(VERB_ALGO, "ASN-AAAA-filter: superq", &super->qinfo); 230+ if(super_iq->dp && error) 231+ delegpt_log(VERB_ALGO, super_iq->dp); 232+ return; 233+ } else if (error) { 234+ verbose(VERB_ALGO, "ASN-AAAA-filter: mark as failed, " 235+ "and go to target query."); 236+ /* see if the failure did get (parent-lame) info */ 237+ if(!cache_fill_missing(super->env, 238+ super_iq->qchase.qclass, super->region, 239+ super_iq->dp)) 240+ log_err("ASN-AAAA-filter: out of memory adding missing"); 241+ dpns->resolved = 1; /* mark as failed */ 242+ } 243+} 244+/* ASN: End of added code */ 245+ 246 /* 247 * Return priming query results to interested super querystates. 248 * 249@@ -3114,6 +3223,9 @@ 250 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*) 251 super->minfo[id])->state == DSNS_FIND_STATE) 252 processDSNSResponse(qstate, id, super); 253+ else if (super->qinfo.qtype == LDNS_RR_TYPE_AAAA && ((struct iter_qstate*) 254+ super->minfo[id])->state == ASN_FETCH_A_FOR_AAAA_STATE) 255+ asn_processAAAAResponse(qstate, id, super); 256 else if(qstate->return_rcode != LDNS_RCODE_NOERROR) 257 error_supers(qstate, id, super); 258 else if(qstate->is_priming) 259@@ -3151,6 +3263,9 @@ 260 case INIT_REQUEST_3_STATE: 261 cont = processInitRequest3(qstate, iq, id); 262 break; 263+ case ASN_FETCH_A_FOR_AAAA_STATE: 264+ cont = asn_processQueryAAAA(qstate, iq, ie, id); 265+ break; 266 case QUERYTARGETS_STATE: 267 cont = processQueryTargets(qstate, iq, ie, id); 268 break; 269@@ -3460,6 +3575,8 @@ 270 return "INIT REQUEST STATE (stage 2)"; 271 case INIT_REQUEST_3_STATE: 272 return "INIT REQUEST STATE (stage 3)"; 273+ case ASN_FETCH_A_FOR_AAAA_STATE: 274+ return "ASN_FETCH_A_FOR_AAAA_STATE"; 275 case QUERYTARGETS_STATE : 276 return "QUERY TARGETS STATE"; 277 case PRIME_RESP_STATE : 278@@ -3484,6 +3601,7 @@ 279 case INIT_REQUEST_STATE : 280 case INIT_REQUEST_2_STATE : 281 case INIT_REQUEST_3_STATE : 282+ case ASN_FETCH_A_FOR_AAAA_STATE : 283 case QUERYTARGETS_STATE : 284 case COLLECT_CLASS_STATE : 285 return 0; 286Index: trunk/iterator/iterator.h 287=================================================================== 288--- trunk/iterator/iterator.h (revision 4357) 289+++ trunk/iterator/iterator.h (working copy) 290@@ -130,6 +130,9 @@ 291 */ 292 int* target_fetch_policy; 293 294+ /** ASN: AAAA-filter flag */ 295+ int aaaa_filter; 296+ 297 /** lock on ratelimit counter */ 298 lock_basic_type queries_ratelimit_lock; 299 /** number of queries that have been ratelimited */ 300@@ -182,6 +185,14 @@ 301 INIT_REQUEST_3_STATE, 302 303 /** 304+ * This state is responsible for intercepting AAAA queries, 305+ * and launch a A subquery on the same target, to populate the 306+ * cache with A records, so the AAAA filter scrubbing logic can 307+ * work. 308+ */ 309+ ASN_FETCH_A_FOR_AAAA_STATE, 310+ 311+ /** 312 * Each time a delegation point changes for a given query or a 313 * query times out and/or wakes up, this state is (re)visited. 314 * This state is responsible for iterating through a list of 315@@ -364,6 +375,13 @@ 316 * be used when creating the state. A higher one will be attempted. 317 */ 318 int refetch_glue; 319+ 320+ /** 321+ * ASN: This is a flag that, if true, means that this query is 322+ * for fetching A records to populate cache and determine if we must 323+ * return AAAA records or not. 324+ */ 325+ int fetch_a_for_aaaa; 326 327 /** list of pending queries to authoritative servers. */ 328 struct outbound_list outlist; 329Index: trunk/pythonmod/interface.i 330=================================================================== 331--- trunk/pythonmod/interface.i (revision 4357) 332+++ trunk/pythonmod/interface.i (working copy) 333@@ -851,6 +851,7 @@ 334 int harden_dnssec_stripped; 335 int harden_referral_path; 336 int use_caps_bits_for_id; 337+ int aaaa_filter; /* ASN */ 338 struct config_strlist* private_address; 339 struct config_strlist* private_domain; 340 size_t unwanted_threshold; 341Index: trunk/util/config_file.c 342=================================================================== 343--- trunk/util/config_file.c (revision 4357) 344+++ trunk/util/config_file.c (working copy) 345@@ -195,6 +195,7 @@ 346 cfg->harden_referral_path = 0; 347 cfg->harden_algo_downgrade = 0; 348 cfg->use_caps_bits_for_id = 0; 349+ cfg->aaaa_filter = 0; /* ASN: default is disabled */ 350 cfg->caps_whitelist = NULL; 351 cfg->private_address = NULL; 352 cfg->private_domain = NULL; 353Index: trunk/util/config_file.h 354=================================================================== 355--- trunk/util/config_file.h (revision 4357) 356+++ trunk/util/config_file.h (working copy) 357@@ -209,6 +209,8 @@ 358 int harden_algo_downgrade; 359 /** use 0x20 bits in query as random ID bits */ 360 int use_caps_bits_for_id; 361+ /** ASN: enable AAAA filter? */ 362+ int aaaa_filter; 363 /** 0x20 whitelist, domains that do not use capsforid */ 364 struct config_strlist* caps_whitelist; 365 /** strip away these private addrs from answers, no DNS Rebinding */ 366Index: trunk/util/configlexer.lex 367=================================================================== 368--- trunk/util/configlexer.lex (revision 4357) 369+++ trunk/util/configlexer.lex (working copy) 370@@ -279,6 +279,7 @@ 371 use-caps-for-id{COLON} { YDVAR(1, VAR_USE_CAPS_FOR_ID) } 372 caps-whitelist{COLON} { YDVAR(1, VAR_CAPS_WHITELIST) } 373 unwanted-reply-threshold{COLON} { YDVAR(1, VAR_UNWANTED_REPLY_THRESHOLD) } 374+aaaa-filter{COLON} { YDVAR(1, VAR_AAAA_FILTER) } 375 private-address{COLON} { YDVAR(1, VAR_PRIVATE_ADDRESS) } 376 private-domain{COLON} { YDVAR(1, VAR_PRIVATE_DOMAIN) } 377 prefetch-key{COLON} { YDVAR(1, VAR_PREFETCH_KEY) } 378Index: trunk/util/configparser.y 379=================================================================== 380--- trunk/util/configparser.y (revision 4357) 381+++ trunk/util/configparser.y (working copy) 382@@ -95,6 +95,7 @@ 383 %token VAR_STATISTICS_CUMULATIVE VAR_OUTGOING_PORT_PERMIT 384 %token VAR_OUTGOING_PORT_AVOID VAR_DLV_ANCHOR_FILE VAR_DLV_ANCHOR 385 %token VAR_NEG_CACHE_SIZE VAR_HARDEN_REFERRAL_PATH VAR_PRIVATE_ADDRESS 386+%token VAR_AAAA_FILTER 387 %token VAR_PRIVATE_DOMAIN VAR_REMOTE_CONTROL VAR_CONTROL_ENABLE 388 %token VAR_CONTROL_INTERFACE VAR_CONTROL_PORT VAR_SERVER_KEY_FILE 389 %token VAR_SERVER_CERT_FILE VAR_CONTROL_KEY_FILE VAR_CONTROL_CERT_FILE 390@@ -203,6 +204,7 @@ 391 server_dlv_anchor_file | server_dlv_anchor | server_neg_cache_size | 392 server_harden_referral_path | server_private_address | 393 server_private_domain | server_extended_statistics | 394+ server_aaaa_filter | 395 server_local_data_ptr | server_jostle_timeout | 396 server_unwanted_reply_threshold | server_log_time_ascii | 397 server_domain_insecure | server_val_sig_skew_min | 398@@ -1183,6 +1185,15 @@ 399 OUTYY(("P(server_caps_whitelist:%s)\n", $2)); 400 if(!cfg_strlist_insert(&cfg_parser->cfg->caps_whitelist, $2)) 401 yyerror("out of memory"); 402+ } 403+ ; 404+server_aaaa_filter: VAR_AAAA_FILTER STRING_ARG 405+ { 406+ OUTYY(("P(server_aaaa_filter:%s)\n", $2)); 407+ if(strcmp($2, "yes") != 0 && strcmp($2, "no") != 0) 408+ yyerror("expected yes or no."); 409+ else cfg_parser->cfg->aaaa_filter = (strcmp($2, "yes")==0); 410+ free($2); 411 } 412 ; 413 server_private_address: VAR_PRIVATE_ADDRESS STRING_ARG 414