2 * dns64/dns64.c - DNS64 module
4 * Copyright (c) 2009, Viagénie. All rights reserved.
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39 * This file contains a module that performs DNS64 query processing.
43 #include "dns64/dns64.h"
44 #include "services/cache/dns.h"
45 #include "services/cache/rrset.h"
46 #include "util/config_file.h"
47 #include "util/data/msgreply.h"
48 #include "util/fptr_wlist.h"
49 #include "util/net_help.h"
50 #include "util/regional.h"
51 #include "util/storage/dnstree.h"
52 #include "util/data/dname.h"
53 #include "sldns/str2wire.h"
55 /******************************************************************************
59 ******************************************************************************/
62 * This is the default DNS64 prefix that is used whent he dns64 module is listed
63 * in module-config but when the dns64-prefix variable is not present.
65 static const char DEFAULT_DNS64_PREFIX[] = "64:ff9b::/96";
68 * Maximum length of a domain name in a PTR query in the .in-addr.arpa tree.
70 #define MAX_PTR_QNAME_IPV4 30
73 * State of DNS64 processing for a query.
76 DNS64_INTERNAL_QUERY, /**< Internally-generated query, no DNS64
78 DNS64_NEW_QUERY, /**< Query for which we're the first module in
80 DNS64_SUBQUERY_FINISHED /**< Query for which we generated a sub-query, and
81 for which this sub-query is finished. */
85 * Per-query module-specific state. For the DNS64 module.
88 /** State of the DNS64 module. */
89 enum dns64_state state;
90 /** If the dns64 module started with no_cache bool set in the qstate,
91 * a message to tell it to not modify the cache contents, then this
92 * is true. The dns64 module is then free to modify that flag for
94 * Otherwise, it is false, the dns64 module was not told to no_cache */
95 int started_no_cache_store;
98 /******************************************************************************
102 ******************************************************************************/
105 * This structure contains module configuration information. One instance of
106 * this structure exists per instance of the module. Normally there is only one
107 * instance of the module.
111 * DNS64 prefix address. We're using a full sockaddr instead of just an
112 * in6_addr because we can reuse Unbound's generic string parsing functions.
113 * It will always contain a sockaddr_in6, and only the sin6_addr member will
116 struct sockaddr_storage prefix_addr;
119 * This is always sizeof(sockaddr_in6).
121 socklen_t prefix_addrlen;
124 * This is the CIDR length of the prefix. It needs to be between 0 and 96.
129 * Tree of names for which AAAA is ignored. always synthesize from A.
131 rbtree_type ignore_aaaa;
135 /******************************************************************************
137 * UTILITY FUNCTIONS *
139 ******************************************************************************/
142 * Generic macro for swapping two variables.
144 * \param t Type of the variables. (e.g. int)
145 * \param a First variable.
146 * \param b Second variable.
148 * \warning Do not attempt something foolish such as swap(int,a++,b++)!
150 #define swap(t,a,b) do {t x = a; a = b; b = x;} while(0)
155 * \param begin Points to the first character of the string.
156 * \param end Points one past the last character of the string.
159 reverse(char* begin, char* end)
161 while ( begin < --end ) {
162 swap(char, *begin, *end);
168 * Convert an unsigned integer to a string. The point of this function is that
169 * of being faster than sprintf().
171 * \param n The number to be converted.
172 * \param s The result will be written here. Must be large enough, be careful!
174 * \return The number of characters written.
177 uitoa(unsigned n, char* s)
181 *ss++ = '0' + n % 10;
188 * Extract an IPv4 address embedded in the IPv6 address \a ipv6 at offset \a
189 * offset (in bits). Note that bits are not necessarily aligned on bytes so we
190 * need to be careful.
192 * \param ipv6 IPv6 address represented as a 128-bit array in big-endian
194 * \param offset Index of the MSB of the IPv4 address embedded in the IPv6
198 extract_ipv4(const uint8_t ipv6[16], const int offset)
200 uint32_t ipv4 = (uint32_t)ipv6[offset/8+0] << (24 + (offset%8))
201 | (uint32_t)ipv6[offset/8+1] << (16 + (offset%8))
202 | (uint32_t)ipv6[offset/8+2] << ( 8 + (offset%8))
203 | (uint32_t)ipv6[offset/8+3] << ( 0 + (offset%8));
205 ipv4 |= (uint32_t)ipv6[offset/8+4] >> (8 - offset%8);
210 * Builds the PTR query name corresponding to an IPv4 address. For example,
211 * given the number 3,464,175,361, this will build the string
212 * "\03206\03123\0231\011\07in-addr\04arpa".
214 * \param ipv4 IPv4 address represented as an unsigned 32-bit number.
215 * \param ptr The result will be written here. Must be large enough, be
218 * \return The number of characters written.
221 ipv4_to_ptr(uint32_t ipv4, char ptr[MAX_PTR_QNAME_IPV4])
223 static const char IPV4_PTR_SUFFIX[] = "\07in-addr\04arpa";
227 for (i = 0; i < 4; ++i) {
228 *c = uitoa((unsigned int)(ipv4 % 256), c + 1);
233 memmove(c, IPV4_PTR_SUFFIX, sizeof(IPV4_PTR_SUFFIX));
235 return c + sizeof(IPV4_PTR_SUFFIX) - ptr;
239 * Converts an IPv6-related domain name string from a PTR query into an IPv6
240 * address represented as a 128-bit array.
242 * \param ptr The domain name. (e.g. "\011[...]\010\012\016\012\03ip6\04arpa")
243 * \param ipv6 The result will be written here, in network byte order.
245 * \return 1 on success, 0 on failure.
248 ptr_to_ipv6(const char* ptr, uint8_t ipv6[16])
252 for (i = 0; i < 64; i++) {
258 if (ptr[i] >= '0' && ptr[i] <= '9') {
260 } else if (ptr[i] >= 'a' && ptr[i] <= 'f') {
261 x = ptr[i] - 'a' + 10;
262 } else if (ptr[i] >= 'A' && ptr[i] <= 'F') {
263 x = ptr[i] - 'A' + 10;
268 ipv6[15-i/4] |= x << (2 * ((i-1) % 4));
275 * Synthesize an IPv6 address based on an IPv4 address and the DNS64 prefix.
277 * \param prefix_addr DNS64 prefix address.
278 * \param prefix_net CIDR length of the DNS64 prefix. Must be between 0 and 96.
279 * \param a IPv4 address.
280 * \param aaaa IPv6 address. The result will be written here.
283 synthesize_aaaa(const uint8_t prefix_addr[16], int prefix_net,
284 const uint8_t a[4], uint8_t aaaa[16])
286 memcpy(aaaa, prefix_addr, 16);
287 aaaa[prefix_net/8+0] |= a[0] >> (0+prefix_net%8);
288 aaaa[prefix_net/8+1] |= a[0] << (8-prefix_net%8);
289 aaaa[prefix_net/8+1] |= a[1] >> (0+prefix_net%8);
290 aaaa[prefix_net/8+2] |= a[1] << (8-prefix_net%8);
291 aaaa[prefix_net/8+2] |= a[2] >> (0+prefix_net%8);
292 aaaa[prefix_net/8+3] |= a[2] << (8-prefix_net%8);
293 aaaa[prefix_net/8+3] |= a[3] >> (0+prefix_net%8);
294 if (prefix_net/8+4 < 16) /* <-- my beautiful symmetry is destroyed! */
295 aaaa[prefix_net/8+4] |= a[3] << (8-prefix_net%8);
299 /******************************************************************************
301 * DNS64 MODULE FUNCTIONS *
303 ******************************************************************************/
306 * insert ignore_aaaa element into the tree
307 * @param dns64_env: module env.
308 * @param str: string with domain name.
309 * @return false on failure.
312 dns64_insert_ignore_aaaa(struct dns64_env* dns64_env, char* str)
314 /* parse and insert element */
315 struct name_tree_node* node;
316 node = (struct name_tree_node*)calloc(1, sizeof(*node));
318 log_err("out of memory");
321 node->name = sldns_str2wire_dname(str, &node->len);
324 log_err("cannot parse dns64-ignore-aaaa: %s", str);
327 node->labs = dname_count_labels(node->name);
328 node->dclass = LDNS_RR_CLASS_IN;
329 if(!name_tree_insert(&dns64_env->ignore_aaaa, node,
330 node->name, node->len, node->labs, node->dclass)) {
331 /* ignore duplicate element */
340 * This function applies the configuration found in the parsed configuration
341 * file \a cfg to this instance of the dns64 module. Currently only the DNS64
342 * prefix (a.k.a. Pref64) is configurable.
344 * \param dns64_env Module-specific global parameters.
345 * \param cfg Parsed configuration file.
348 dns64_apply_cfg(struct dns64_env* dns64_env, struct config_file* cfg)
350 struct config_strlist* s;
351 verbose(VERB_ALGO, "dns64-prefix: %s", cfg->dns64_prefix);
352 if (!netblockstrtoaddr(cfg->dns64_prefix ? cfg->dns64_prefix :
353 DEFAULT_DNS64_PREFIX, 0, &dns64_env->prefix_addr,
354 &dns64_env->prefix_addrlen, &dns64_env->prefix_net)) {
355 log_err("cannot parse dns64-prefix netblock: %s", cfg->dns64_prefix);
358 if (!addr_is_ip6(&dns64_env->prefix_addr, dns64_env->prefix_addrlen)) {
359 log_err("dns64_prefix is not IPv6: %s", cfg->dns64_prefix);
362 if (dns64_env->prefix_net < 0 || dns64_env->prefix_net > 96) {
363 log_err("dns64-prefix length it not between 0 and 96: %s",
367 for(s = cfg->dns64_ignore_aaaa; s; s = s->next) {
368 if(!dns64_insert_ignore_aaaa(dns64_env, s->str))
371 name_tree_init_parents(&dns64_env->ignore_aaaa);
376 * Initializes this instance of the dns64 module.
378 * \param env Global state of all module instances.
379 * \param id This instance's ID number.
382 dns64_init(struct module_env* env, int id)
384 struct dns64_env* dns64_env =
385 (struct dns64_env*)calloc(1, sizeof(struct dns64_env));
387 log_err("malloc failure");
390 env->modinfo[id] = (void*)dns64_env;
391 name_tree_init(&dns64_env->ignore_aaaa);
392 if (!dns64_apply_cfg(dns64_env, env->cfg)) {
393 log_err("dns64: could not apply configuration settings.");
399 /** free ignore AAAA elements */
401 free_ignore_aaaa_node(rbnode_type* node, void* ATTR_UNUSED(arg))
403 struct name_tree_node* n = (struct name_tree_node*)node;
410 * Deinitializes this instance of the dns64 module.
412 * \param env Global state of all module instances.
413 * \param id This instance's ID number.
416 dns64_deinit(struct module_env* env, int id)
418 struct dns64_env* dns64_env;
421 dns64_env = (struct dns64_env*)env->modinfo[id];
423 traverse_postorder(&dns64_env->ignore_aaaa, free_ignore_aaaa_node,
426 free(env->modinfo[id]);
427 env->modinfo[id] = NULL;
431 * Handle PTR queries for IPv6 addresses. If the address belongs to the DNS64
432 * prefix, we must do a PTR query for the corresponding IPv4 address instead.
434 * \param qstate Query state structure.
435 * \param id This module instance's ID number.
437 * \return The new state of the query.
439 static enum module_ext_state
440 handle_ipv6_ptr(struct module_qstate* qstate, int id)
442 struct dns64_env* dns64_env = (struct dns64_env*)qstate->env->modinfo[id];
443 struct module_qstate* subq = NULL;
444 struct query_info qinfo;
445 struct sockaddr_in6 sin6;
447 /* Convert the PTR query string to an IPv6 address. */
448 memset(&sin6, 0, sizeof(sin6));
449 sin6.sin6_family = AF_INET6;
450 if (!ptr_to_ipv6((char*)qstate->qinfo.qname, sin6.sin6_addr.s6_addr))
451 return module_wait_module; /* Let other module handle this. */
454 * If this IPv6 address is not part of our DNS64 prefix, then we don't need
455 * to do anything. Let another module handle the query.
457 if (addr_in_common((struct sockaddr_storage*)&sin6, 128,
458 &dns64_env->prefix_addr, dns64_env->prefix_net,
459 (socklen_t)sizeof(sin6)) != dns64_env->prefix_net)
460 return module_wait_module;
462 verbose(VERB_ALGO, "dns64: rewrite PTR record");
465 * Create a new PTR query info for the domain name corresponding to the IPv4
466 * address corresponding to the IPv6 address corresponding to the original
467 * PTR query domain name.
469 qinfo = qstate->qinfo;
470 if (!(qinfo.qname = regional_alloc(qstate->region, MAX_PTR_QNAME_IPV4)))
472 qinfo.qname_len = ipv4_to_ptr(extract_ipv4(sin6.sin6_addr.s6_addr,
473 dns64_env->prefix_net), (char*)qinfo.qname);
475 /* Create the new sub-query. */
476 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
477 if(!(*qstate->env->attach_sub)(qstate, &qinfo, qstate->query_flags, 0, 0,
482 subq->ext_state[id] = module_state_initial;
483 subq->minfo[id] = NULL;
486 return module_wait_subquery;
489 static enum module_ext_state
490 generate_type_A_query(struct module_qstate* qstate, int id)
492 struct module_qstate* subq = NULL;
493 struct query_info qinfo;
495 verbose(VERB_ALGO, "dns64: query A record");
497 /* Create a new query info. */
498 qinfo = qstate->qinfo;
499 qinfo.qtype = LDNS_RR_TYPE_A;
501 /* Start the sub-query. */
502 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
503 if(!(*qstate->env->attach_sub)(qstate, &qinfo, qstate->query_flags, 0,
506 verbose(VERB_ALGO, "dns64: sub-query creation failed");
511 subq->ext_state[id] = module_state_initial;
512 subq->minfo[id] = NULL;
515 return module_wait_subquery;
519 * See if query name is in the always synth config.
520 * The ignore-aaaa list has names for which the AAAA for the domain is
521 * ignored and the A is always used to create the answer.
522 * @param qstate: query state.
523 * @param id: module id.
524 * @return true if the name is covered by ignore-aaaa.
527 dns64_always_synth_for_qname(struct module_qstate* qstate, int id)
529 struct dns64_env* dns64_env = (struct dns64_env*)qstate->env->modinfo[id];
530 int labs = dname_count_labels(qstate->qinfo.qname);
531 struct name_tree_node* node = name_tree_lookup(&dns64_env->ignore_aaaa,
532 qstate->qinfo.qname, qstate->qinfo.qname_len, labs,
533 qstate->qinfo.qclass);
534 return (node != NULL);
538 * Handles the "pass" event for a query. This event is received when a new query
539 * is received by this module. The query may have been generated internally by
540 * another module, in which case we don't want to do any special processing
541 * (this is an interesting discussion topic), or it may be brand new, e.g.
542 * received over a socket, in which case we do want to apply DNS64 processing.
544 * \param qstate A structure representing the state of the query that has just
545 * received the "pass" event.
546 * \param id This module's instance ID.
548 * \return The new state of the query.
550 static enum module_ext_state
551 handle_event_pass(struct module_qstate* qstate, int id)
553 struct dns64_qstate* iq = (struct dns64_qstate*)qstate->minfo[id];
554 if (iq && iq->state == DNS64_NEW_QUERY
555 && qstate->qinfo.qtype == LDNS_RR_TYPE_PTR
556 && qstate->qinfo.qname_len == 74
557 && !strcmp((char*)&qstate->qinfo.qname[64], "\03ip6\04arpa"))
558 /* Handle PTR queries for IPv6 addresses. */
559 return handle_ipv6_ptr(qstate, id);
561 if (qstate->env->cfg->dns64_synthall &&
562 iq && iq->state == DNS64_NEW_QUERY
563 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA)
564 return generate_type_A_query(qstate, id);
566 if(dns64_always_synth_for_qname(qstate, id) &&
567 iq && iq->state == DNS64_NEW_QUERY
568 && !(qstate->query_flags & BIT_CD)
569 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
570 verbose(VERB_ALGO, "dns64: ignore-aaaa and synthesize anyway");
571 return generate_type_A_query(qstate, id);
574 /* We are finished when our sub-query is finished. */
575 if (iq && iq->state == DNS64_SUBQUERY_FINISHED)
576 return module_finished;
578 /* Otherwise, pass request to next module. */
579 verbose(VERB_ALGO, "dns64: pass to next module");
580 return module_wait_module;
584 * Handles the "done" event for a query. We need to analyze the response and
585 * maybe issue a new sub-query for the A record.
587 * \param qstate A structure representing the state of the query that has just
588 * received the "pass" event.
589 * \param id This module's instance ID.
591 * \return The new state of the query.
593 static enum module_ext_state
594 handle_event_moddone(struct module_qstate* qstate, int id)
596 struct dns64_qstate* iq = (struct dns64_qstate*)qstate->minfo[id];
598 * In many cases we have nothing special to do. From most to least common:
600 * - An internal query.
601 * - A query for a record type other than AAAA.
602 * - CD FLAG was set on querier
603 * - An AAAA query for which an error was returned.(qstate.return_rcode)
604 * -> treated as servfail thus synthesize (sec 5.1.3 6147), thus
605 * synthesize in (sec 5.1.2 of RFC6147).
606 * - A successful AAAA query with an answer.
608 if((!iq || iq->state != DNS64_INTERNAL_QUERY)
609 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA
610 && !(qstate->query_flags & BIT_CD)
611 && !(qstate->return_msg &&
612 qstate->return_msg->rep &&
613 reply_find_answer_rrset(&qstate->qinfo,
614 qstate->return_msg->rep)))
615 /* not internal, type AAAA, not CD, and no answer RRset,
616 * So, this is a AAAA noerror/nodata answer */
617 return generate_type_A_query(qstate, id);
619 if((!iq || iq->state != DNS64_INTERNAL_QUERY)
620 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA
621 && !(qstate->query_flags & BIT_CD)
622 && dns64_always_synth_for_qname(qstate, id)) {
623 /* if it is not internal, AAAA, not CD and listed domain,
624 * generate from A record and ignore AAAA */
625 verbose(VERB_ALGO, "dns64: ignore-aaaa and synthesize anyway");
626 return generate_type_A_query(qstate, id);
629 /* Store the response in cache. */
630 if ( (!iq || !iq->started_no_cache_store) &&
631 qstate->return_msg && qstate->return_msg->rep &&
632 !dns_cache_store(qstate->env, &qstate->qinfo, qstate->return_msg->rep,
633 0, 0, 0, NULL, qstate->query_flags))
634 log_err("out of memory");
637 return module_finished;
641 * This is the module's main() function. It gets called each time a query
642 * receives an event which we may need to handle. We respond by updating the
643 * state of the query.
645 * \param qstate Structure containing the state of the query.
646 * \param event Event that has just been received.
647 * \param id This module's instance ID.
648 * \param outbound State of a DNS query on an authoritative server. We never do
649 * our own queries ourselves (other modules do it for us), so
653 dns64_operate(struct module_qstate* qstate, enum module_ev event, int id,
654 struct outbound_entry* outbound)
656 struct dns64_qstate* iq;
658 verbose(VERB_QUERY, "dns64[module %d] operate: extstate:%s event:%s",
659 id, strextstate(qstate->ext_state[id]),
660 strmodulevent(event));
661 log_query_info(VERB_QUERY, "dns64 operate: query", &qstate->qinfo);
664 case module_event_new:
665 /* Tag this query as being new and fall through. */
666 iq = (struct dns64_qstate*)regional_alloc(
667 qstate->region, sizeof(*iq));
668 qstate->minfo[id] = iq;
669 iq->state = DNS64_NEW_QUERY;
670 iq->started_no_cache_store = qstate->no_cache_store;
671 qstate->no_cache_store = 1;
673 case module_event_pass:
674 qstate->ext_state[id] = handle_event_pass(qstate, id);
676 case module_event_moddone:
677 qstate->ext_state[id] = handle_event_moddone(qstate, id);
680 qstate->ext_state[id] = module_finished;
683 if(qstate->ext_state[id] == module_finished) {
684 iq = (struct dns64_qstate*)qstate->minfo[id];
685 if(iq && iq->state != DNS64_INTERNAL_QUERY)
686 qstate->no_cache_store = iq->started_no_cache_store;
691 dns64_synth_aaaa_data(const struct ub_packed_rrset_key* fk,
692 const struct packed_rrset_data* fd,
693 struct ub_packed_rrset_key *dk,
694 struct packed_rrset_data **dd_out, struct regional *region,
695 struct dns64_env* dns64_env )
697 struct packed_rrset_data *dd;
700 * Create synthesized AAAA RR set data. We need to allocated extra memory
701 * for the RRs themselves. Each RR has a length, TTL, pointer to wireformat
702 * data, 2 bytes of data length, and 16 bytes of IPv6 address.
704 if(fd->count > RR_COUNT_MAX) {
706 return; /* integer overflow protection in alloc */
708 if (!(dd = *dd_out = regional_alloc(region,
709 sizeof(struct packed_rrset_data)
710 + fd->count * (sizeof(size_t) + sizeof(time_t) +
711 sizeof(uint8_t*) + 2 + 16)))) {
712 log_err("out of memory");
716 /* Copy attributes from A RR set. */
718 dd->count = fd->count;
720 dd->trust = fd->trust;
721 dd->security = fd->security;
724 * Synthesize AAAA records. Adjust pointers in structure.
727 (size_t*)((uint8_t*)dd + sizeof(struct packed_rrset_data));
728 dd->rr_data = (uint8_t**)&dd->rr_len[dd->count];
729 dd->rr_ttl = (time_t*)&dd->rr_data[dd->count];
730 for(i = 0; i < fd->count; ++i) {
731 if (fd->rr_len[i] != 6 || fd->rr_data[i][0] != 0
732 || fd->rr_data[i][1] != 4) {
738 (uint8_t*)&dd->rr_ttl[dd->count] + 18*i;
739 dd->rr_data[i][0] = 0;
740 dd->rr_data[i][1] = 16;
742 ((struct sockaddr_in6*)&dns64_env->prefix_addr)->sin6_addr.s6_addr,
743 dns64_env->prefix_net, &fd->rr_data[i][2],
744 &dd->rr_data[i][2] );
745 dd->rr_ttl[i] = fd->rr_ttl[i];
749 * Create synthesized AAAA RR set key. This is mostly just bookkeeping,
750 * nothing interesting here.
758 dk->rk.dname = (uint8_t*)regional_alloc_init(region,
759 fk->rk.dname, fk->rk.dname_len);
762 log_err("out of memory");
767 dk->rk.type = htons(LDNS_RR_TYPE_AAAA);
768 memset(&dk->entry, 0, sizeof(dk->entry));
770 dk->entry.hash = rrset_key_hash(&dk->rk);
776 * Synthesize an AAAA RR set from an A sub-query's answer and add it to the
777 * original empty response.
779 * \param id This module's instance ID.
780 * \param super Original AAAA query.
781 * \param qstate A query.
784 dns64_adjust_a(int id, struct module_qstate* super, struct module_qstate* qstate)
786 struct dns64_env* dns64_env = (struct dns64_env*)super->env->modinfo[id];
787 struct reply_info *rep, *cp;
789 struct packed_rrset_data* fd, *dd;
790 struct ub_packed_rrset_key* fk, *dk;
792 verbose(VERB_ALGO, "converting A answers to AAAA answers");
794 log_assert(super->region);
795 log_assert(qstate->return_msg);
796 log_assert(qstate->return_msg->rep);
798 /* If dns64-synthall is enabled, return_msg is not initialized */
799 if(!super->return_msg) {
800 super->return_msg = (struct dns_msg*)regional_alloc(
801 super->region, sizeof(struct dns_msg));
802 if(!super->return_msg)
804 memset(super->return_msg, 0, sizeof(*super->return_msg));
805 super->return_msg->qinfo = super->qinfo;
808 rep = qstate->return_msg->rep;
811 * Build the actual reply.
813 cp = construct_reply_info_base(super->region, rep->flags, rep->qdcount,
814 rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl,
815 rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
816 rep->rrset_count, rep->security);
820 /* allocate ub_key structures special or not */
821 if(!reply_info_alloc_rrset_keys(cp, NULL, super->region)) {
825 /* copy everything and replace A by AAAA */
826 for(i=0; i<cp->rrset_count; i++) {
829 fd = (struct packed_rrset_data*)fk->entry.data;
833 if(i<rep->an_numrrsets && fk->rk.type == htons(LDNS_RR_TYPE_A)) {
834 /* also sets dk->entry.hash */
835 dns64_synth_aaaa_data(fk, fd, dk, &dd, super->region, dns64_env);
838 /* Delete negative AAAA record from cache stored by
839 * the iterator module */
840 rrset_cache_remove(super->env->rrset_cache, dk->rk.dname,
841 dk->rk.dname_len, LDNS_RR_TYPE_AAAA,
842 LDNS_RR_CLASS_IN, 0);
843 /* Delete negative AAAA in msg cache for CNAMEs,
844 * stored by the iterator module */
845 if(i != 0) /* if not the first RR */
846 msg_cache_remove(super->env, dk->rk.dname,
847 dk->rk.dname_len, LDNS_RR_TYPE_AAAA,
848 LDNS_RR_CLASS_IN, 0);
850 dk->entry.hash = fk->entry.hash;
851 dk->rk.dname = (uint8_t*)regional_alloc_init(super->region,
852 fk->rk.dname, fk->rk.dname_len);
857 s = packed_rrset_sizeof(fd);
858 dd = (struct packed_rrset_data*)regional_alloc_init(
859 super->region, fd, s);
865 packed_rrset_ptr_fixup(dd);
866 dk->entry.data = (void*)dd;
869 /* Commit changes. */
870 super->return_msg->rep = cp;
874 * Generate a response for the original IPv6 PTR query based on an IPv4 PTR
875 * sub-query's response.
877 * \param qstate IPv4 PTR sub-query.
878 * \param super Original IPv6 PTR query.
881 dns64_adjust_ptr(struct module_qstate* qstate, struct module_qstate* super)
883 struct ub_packed_rrset_key* answer;
885 verbose(VERB_ALGO, "adjusting PTR reply");
887 /* Copy the sub-query's reply to the parent. */
888 if (!(super->return_msg = (struct dns_msg*)regional_alloc(super->region,
889 sizeof(struct dns_msg))))
891 super->return_msg->qinfo = super->qinfo;
892 super->return_msg->rep = reply_info_copy(qstate->return_msg->rep, NULL,
896 * Adjust the domain name of the answer RR set so that it matches the
897 * initial query's domain name.
899 answer = reply_find_answer_rrset(&qstate->qinfo, super->return_msg->rep);
901 answer->rk.dname = super->qinfo.qname;
902 answer->rk.dname_len = super->qinfo.qname_len;
907 * This function is called when a sub-query finishes to inform the parent query.
909 * We issue two kinds of sub-queries: PTR and A.
911 * \param qstate State of the sub-query.
912 * \param id This module's instance ID.
913 * \param super State of the super-query.
916 dns64_inform_super(struct module_qstate* qstate, int id,
917 struct module_qstate* super)
919 struct dns64_qstate* super_dq = (struct dns64_qstate*)super->minfo[id];
920 log_query_info(VERB_ALGO, "dns64: inform_super, sub is",
922 log_query_info(VERB_ALGO, "super is", &super->qinfo);
925 * Signal that the sub-query is finished, no matter whether we are
926 * successful or not. This lets the state machine terminate.
929 super_dq = (struct dns64_qstate*)regional_alloc(super->region,
931 super->minfo[id] = super_dq;
932 memset(super_dq, 0, sizeof(*super_dq));
933 super_dq->started_no_cache_store = super->no_cache_store;
935 super_dq->state = DNS64_SUBQUERY_FINISHED;
937 /* If there is no successful answer, we're done. */
938 if (qstate->return_rcode != LDNS_RCODE_NOERROR
939 || !qstate->return_msg
940 || !qstate->return_msg->rep) {
944 /* Use return code from A query in response to client. */
945 if (super->return_rcode != LDNS_RCODE_NOERROR)
946 super->return_rcode = qstate->return_rcode;
948 /* Generate a response suitable for the original query. */
949 if (qstate->qinfo.qtype == LDNS_RR_TYPE_A) {
950 dns64_adjust_a(id, super, qstate);
952 log_assert(qstate->qinfo.qtype == LDNS_RR_TYPE_PTR);
953 dns64_adjust_ptr(qstate, super);
956 /* Store the generated response in cache. */
957 if ( (!super_dq || !super_dq->started_no_cache_store) &&
958 !dns_cache_store(super->env, &super->qinfo, super->return_msg->rep,
959 0, 0, 0, NULL, super->query_flags))
960 log_err("out of memory");
964 * Clear module-specific data from query state. Since we do not allocate memory,
965 * it's just a matter of setting a pointer to NULL.
967 * \param qstate Query state.
968 * \param id This module's instance ID.
971 dns64_clear(struct module_qstate* qstate, int id)
973 qstate->minfo[id] = NULL;
977 * Returns the amount of global memory that this module uses, not including
980 * \param env Module environment.
981 * \param id This module's instance ID.
984 dns64_get_mem(struct module_env* env, int id)
986 struct dns64_env* dns64_env = (struct dns64_env*)env->modinfo[id];
989 return sizeof(*dns64_env);
993 * The dns64 function block.
995 static struct module_func_block dns64_block = {
997 &dns64_init, &dns64_deinit, &dns64_operate, &dns64_inform_super,
998 &dns64_clear, &dns64_get_mem
1002 * Function for returning the above function block.
1004 struct module_func_block *
1005 dns64_get_funcblock(void)
1007 return &dns64_block;