2 * dns64/dns64.c - DNS64 module
4 * Copyright (c) 2009, Viagénie. All rights reserved.
6 * This software is open source.
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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 * Per-query module-specific state. This is usually a dynamically-allocated
74 * structure, but in our case we only need to store one variable describing the
75 * state the query is in. So we repurpose the minfo pointer by storing an
79 DNS64_INTERNAL_QUERY, /**< Internally-generated query, no DNS64
81 DNS64_NEW_QUERY, /**< Query for which we're the first module in
83 DNS64_SUBQUERY_FINISHED /**< Query for which we generated a sub-query, and
84 for which this sub-query is finished. */
88 /******************************************************************************
92 ******************************************************************************/
95 * This structure contains module configuration information. One instance of
96 * this structure exists per instance of the module. Normally there is only one
97 * instance of the module.
101 * DNS64 prefix address. We're using a full sockaddr instead of just an
102 * in6_addr because we can reuse Unbound's generic string parsing functions.
103 * It will always contain a sockaddr_in6, and only the sin6_addr member will
106 struct sockaddr_storage prefix_addr;
109 * This is always sizeof(sockaddr_in6).
111 socklen_t prefix_addrlen;
114 * This is the CIDR length of the prefix. It needs to be between 0 and 96.
119 * Tree of names for which AAAA is ignored. always synthesize from A.
121 rbtree_type ignore_aaaa;
125 /******************************************************************************
127 * UTILITY FUNCTIONS *
129 ******************************************************************************/
132 * Generic macro for swapping two variables.
134 * \param t Type of the variables. (e.g. int)
135 * \param a First variable.
136 * \param b Second variable.
138 * \warning Do not attempt something foolish such as swap(int,a++,b++)!
140 #define swap(t,a,b) do {t x = a; a = b; b = x;} while(0)
145 * \param begin Points to the first character of the string.
146 * \param end Points one past the last character of the string.
149 reverse(char* begin, char* end)
151 while ( begin < --end ) {
152 swap(char, *begin, *end);
158 * Convert an unsigned integer to a string. The point of this function is that
159 * of being faster than sprintf().
161 * \param n The number to be converted.
162 * \param s The result will be written here. Must be large enough, be careful!
164 * \return The number of characters written.
167 uitoa(unsigned n, char* s)
171 *ss++ = '0' + n % 10;
178 * Extract an IPv4 address embedded in the IPv6 address \a ipv6 at offset \a
179 * offset (in bits). Note that bits are not necessarily aligned on bytes so we
180 * need to be careful.
182 * \param ipv6 IPv6 address represented as a 128-bit array in big-endian
184 * \param offset Index of the MSB of the IPv4 address embedded in the IPv6
188 extract_ipv4(const uint8_t ipv6[16], const int offset)
190 uint32_t ipv4 = (uint32_t)ipv6[offset/8+0] << (24 + (offset%8))
191 | (uint32_t)ipv6[offset/8+1] << (16 + (offset%8))
192 | (uint32_t)ipv6[offset/8+2] << ( 8 + (offset%8))
193 | (uint32_t)ipv6[offset/8+3] << ( 0 + (offset%8));
195 ipv4 |= (uint32_t)ipv6[offset/8+4] >> (8 - offset%8);
200 * Builds the PTR query name corresponding to an IPv4 address. For example,
201 * given the number 3,464,175,361, this will build the string
202 * "\03206\03123\0231\011\07in-addr\04arpa".
204 * \param ipv4 IPv4 address represented as an unsigned 32-bit number.
205 * \param ptr The result will be written here. Must be large enough, be
208 * \return The number of characters written.
211 ipv4_to_ptr(uint32_t ipv4, char ptr[MAX_PTR_QNAME_IPV4])
213 static const char IPV4_PTR_SUFFIX[] = "\07in-addr\04arpa";
217 for (i = 0; i < 4; ++i) {
218 *c = uitoa((unsigned int)(ipv4 % 256), c + 1);
223 memmove(c, IPV4_PTR_SUFFIX, sizeof(IPV4_PTR_SUFFIX));
225 return c + sizeof(IPV4_PTR_SUFFIX) - ptr;
229 * Converts an IPv6-related domain name string from a PTR query into an IPv6
230 * address represented as a 128-bit array.
232 * \param ptr The domain name. (e.g. "\011[...]\010\012\016\012\03ip6\04arpa")
233 * \param ipv6 The result will be written here, in network byte order.
235 * \return 1 on success, 0 on failure.
238 ptr_to_ipv6(const char* ptr, uint8_t ipv6[16])
242 for (i = 0; i < 64; i++) {
248 if (ptr[i] >= '0' && ptr[i] <= '9') {
250 } else if (ptr[i] >= 'a' && ptr[i] <= 'f') {
251 x = ptr[i] - 'a' + 10;
252 } else if (ptr[i] >= 'A' && ptr[i] <= 'F') {
253 x = ptr[i] - 'A' + 10;
258 ipv6[15-i/4] |= x << (2 * ((i-1) % 4));
265 * Synthesize an IPv6 address based on an IPv4 address and the DNS64 prefix.
267 * \param prefix_addr DNS64 prefix address.
268 * \param prefix_net CIDR length of the DNS64 prefix. Must be between 0 and 96.
269 * \param a IPv4 address.
270 * \param aaaa IPv6 address. The result will be written here.
273 synthesize_aaaa(const uint8_t prefix_addr[16], int prefix_net,
274 const uint8_t a[4], uint8_t aaaa[16])
276 memcpy(aaaa, prefix_addr, 16);
277 aaaa[prefix_net/8+0] |= a[0] >> (0+prefix_net%8);
278 aaaa[prefix_net/8+1] |= a[0] << (8-prefix_net%8);
279 aaaa[prefix_net/8+1] |= a[1] >> (0+prefix_net%8);
280 aaaa[prefix_net/8+2] |= a[1] << (8-prefix_net%8);
281 aaaa[prefix_net/8+2] |= a[2] >> (0+prefix_net%8);
282 aaaa[prefix_net/8+3] |= a[2] << (8-prefix_net%8);
283 aaaa[prefix_net/8+3] |= a[3] >> (0+prefix_net%8);
284 if (prefix_net/8+4 < 16) /* <-- my beautiful symmetry is destroyed! */
285 aaaa[prefix_net/8+4] |= a[3] << (8-prefix_net%8);
289 /******************************************************************************
291 * DNS64 MODULE FUNCTIONS *
293 ******************************************************************************/
296 * insert ignore_aaaa element into the tree
297 * @param dns64_env: module env.
298 * @param str: string with domain name.
299 * @return false on failure.
302 dns64_insert_ignore_aaaa(struct dns64_env* dns64_env, char* str)
304 /* parse and insert element */
305 struct name_tree_node* node;
306 node = (struct name_tree_node*)calloc(1, sizeof(*node));
308 log_err("out of memory");
311 node->name = sldns_str2wire_dname(str, &node->len);
314 log_err("cannot parse dns64-ignore-aaaa: %s", str);
317 node->labs = dname_count_labels(node->name);
318 node->dclass = LDNS_RR_CLASS_IN;
319 if(!name_tree_insert(&dns64_env->ignore_aaaa, node,
320 node->name, node->len, node->labs, node->dclass)) {
321 /* ignore duplicate element */
330 * This function applies the configuration found in the parsed configuration
331 * file \a cfg to this instance of the dns64 module. Currently only the DNS64
332 * prefix (a.k.a. Pref64) is configurable.
334 * \param dns64_env Module-specific global parameters.
335 * \param cfg Parsed configuration file.
338 dns64_apply_cfg(struct dns64_env* dns64_env, struct config_file* cfg)
340 struct config_strlist* s;
341 verbose(VERB_ALGO, "dns64-prefix: %s", cfg->dns64_prefix);
342 if (!netblockstrtoaddr(cfg->dns64_prefix ? cfg->dns64_prefix :
343 DEFAULT_DNS64_PREFIX, 0, &dns64_env->prefix_addr,
344 &dns64_env->prefix_addrlen, &dns64_env->prefix_net)) {
345 log_err("cannot parse dns64-prefix netblock: %s", cfg->dns64_prefix);
348 if (!addr_is_ip6(&dns64_env->prefix_addr, dns64_env->prefix_addrlen)) {
349 log_err("dns64_prefix is not IPv6: %s", cfg->dns64_prefix);
352 if (dns64_env->prefix_net < 0 || dns64_env->prefix_net > 96) {
353 log_err("dns64-prefix length it not between 0 and 96: %s",
357 for(s = cfg->dns64_ignore_aaaa; s; s = s->next) {
358 if(!dns64_insert_ignore_aaaa(dns64_env, s->str))
361 name_tree_init_parents(&dns64_env->ignore_aaaa);
366 * Initializes this instance of the dns64 module.
368 * \param env Global state of all module instances.
369 * \param id This instance's ID number.
372 dns64_init(struct module_env* env, int id)
374 struct dns64_env* dns64_env =
375 (struct dns64_env*)calloc(1, sizeof(struct dns64_env));
377 log_err("malloc failure");
380 env->modinfo[id] = (void*)dns64_env;
381 name_tree_init(&dns64_env->ignore_aaaa);
382 if (!dns64_apply_cfg(dns64_env, env->cfg)) {
383 log_err("dns64: could not apply configuration settings.");
389 /** free ignore AAAA elements */
391 free_ignore_aaaa_node(rbnode_type* node, void* ATTR_UNUSED(arg))
393 struct name_tree_node* n = (struct name_tree_node*)node;
400 * Deinitializes this instance of the dns64 module.
402 * \param env Global state of all module instances.
403 * \param id This instance's ID number.
406 dns64_deinit(struct module_env* env, int id)
408 struct dns64_env* dns64_env;
411 dns64_env = (struct dns64_env*)env->modinfo[id];
413 traverse_postorder(&dns64_env->ignore_aaaa, free_ignore_aaaa_node,
416 free(env->modinfo[id]);
417 env->modinfo[id] = NULL;
421 * Handle PTR queries for IPv6 addresses. If the address belongs to the DNS64
422 * prefix, we must do a PTR query for the corresponding IPv4 address instead.
424 * \param qstate Query state structure.
425 * \param id This module instance's ID number.
427 * \return The new state of the query.
429 static enum module_ext_state
430 handle_ipv6_ptr(struct module_qstate* qstate, int id)
432 struct dns64_env* dns64_env = (struct dns64_env*)qstate->env->modinfo[id];
433 struct module_qstate* subq = NULL;
434 struct query_info qinfo;
435 struct sockaddr_in6 sin6;
437 /* Convert the PTR query string to an IPv6 address. */
438 memset(&sin6, 0, sizeof(sin6));
439 sin6.sin6_family = AF_INET6;
440 if (!ptr_to_ipv6((char*)qstate->qinfo.qname, sin6.sin6_addr.s6_addr))
441 return module_wait_module; /* Let other module handle this. */
444 * If this IPv6 address is not part of our DNS64 prefix, then we don't need
445 * to do anything. Let another module handle the query.
447 if (addr_in_common((struct sockaddr_storage*)&sin6, 128,
448 &dns64_env->prefix_addr, dns64_env->prefix_net,
449 (socklen_t)sizeof(sin6)) != dns64_env->prefix_net)
450 return module_wait_module;
452 verbose(VERB_ALGO, "dns64: rewrite PTR record");
455 * Create a new PTR query info for the domain name corresponding to the IPv4
456 * address corresponding to the IPv6 address corresponding to the original
457 * PTR query domain name.
459 qinfo = qstate->qinfo;
460 if (!(qinfo.qname = regional_alloc(qstate->region, MAX_PTR_QNAME_IPV4)))
462 qinfo.qname_len = ipv4_to_ptr(extract_ipv4(sin6.sin6_addr.s6_addr,
463 dns64_env->prefix_net), (char*)qinfo.qname);
465 /* Create the new sub-query. */
466 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
467 if(!(*qstate->env->attach_sub)(qstate, &qinfo, qstate->query_flags, 0, 0,
472 subq->ext_state[id] = module_state_initial;
473 subq->minfo[id] = NULL;
476 return module_wait_subquery;
479 static enum module_ext_state
480 generate_type_A_query(struct module_qstate* qstate, int id)
482 struct module_qstate* subq = NULL;
483 struct query_info qinfo;
485 verbose(VERB_ALGO, "dns64: query A record");
487 /* Create a new query info. */
488 qinfo = qstate->qinfo;
489 qinfo.qtype = LDNS_RR_TYPE_A;
491 /* Start the sub-query. */
492 fptr_ok(fptr_whitelist_modenv_attach_sub(qstate->env->attach_sub));
493 if(!(*qstate->env->attach_sub)(qstate, &qinfo, qstate->query_flags, 0,
496 verbose(VERB_ALGO, "dns64: sub-query creation failed");
501 subq->ext_state[id] = module_state_initial;
502 subq->minfo[id] = NULL;
505 return module_wait_subquery;
509 * See if query name is in the always synth config.
510 * The ignore-aaaa list has names for which the AAAA for the domain is
511 * ignored and the A is always used to create the answer.
512 * @param qstate: query state.
513 * @param id: module id.
514 * @return true if the name is covered by ignore-aaaa.
517 dns64_always_synth_for_qname(struct module_qstate* qstate, int id)
519 struct dns64_env* dns64_env = (struct dns64_env*)qstate->env->modinfo[id];
520 int labs = dname_count_labels(qstate->qinfo.qname);
521 struct name_tree_node* node = name_tree_lookup(&dns64_env->ignore_aaaa,
522 qstate->qinfo.qname, qstate->qinfo.qname_len, labs,
523 qstate->qinfo.qclass);
524 return (node != NULL);
528 * Handles the "pass" event for a query. This event is received when a new query
529 * is received by this module. The query may have been generated internally by
530 * another module, in which case we don't want to do any special processing
531 * (this is an interesting discussion topic), or it may be brand new, e.g.
532 * received over a socket, in which case we do want to apply DNS64 processing.
534 * \param qstate A structure representing the state of the query that has just
535 * received the "pass" event.
536 * \param id This module's instance ID.
538 * \return The new state of the query.
540 static enum module_ext_state
541 handle_event_pass(struct module_qstate* qstate, int id)
543 if ((uintptr_t)qstate->minfo[id] == DNS64_NEW_QUERY
544 && qstate->qinfo.qtype == LDNS_RR_TYPE_PTR
545 && qstate->qinfo.qname_len == 74
546 && !strcmp((char*)&qstate->qinfo.qname[64], "\03ip6\04arpa"))
547 /* Handle PTR queries for IPv6 addresses. */
548 return handle_ipv6_ptr(qstate, id);
550 if (qstate->env->cfg->dns64_synthall &&
551 (uintptr_t)qstate->minfo[id] == DNS64_NEW_QUERY
552 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA)
553 return generate_type_A_query(qstate, id);
555 if(dns64_always_synth_for_qname(qstate, id) &&
556 (uintptr_t)qstate->minfo[id] == DNS64_NEW_QUERY
557 && !(qstate->query_flags & BIT_CD)
558 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
559 verbose(VERB_ALGO, "dns64: ignore-aaaa and synthesize anyway");
560 return generate_type_A_query(qstate, id);
563 /* We are finished when our sub-query is finished. */
564 if ((uintptr_t)qstate->minfo[id] == DNS64_SUBQUERY_FINISHED)
565 return module_finished;
567 /* Otherwise, pass request to next module. */
568 verbose(VERB_ALGO, "dns64: pass to next module");
569 return module_wait_module;
573 * Handles the "done" event for a query. We need to analyze the response and
574 * maybe issue a new sub-query for the A record.
576 * \param qstate A structure representing the state of the query that has just
577 * received the "pass" event.
578 * \param id This module's instance ID.
580 * \return The new state of the query.
582 static enum module_ext_state
583 handle_event_moddone(struct module_qstate* qstate, int id)
586 * In many cases we have nothing special to do. From most to least common:
588 * - An internal query.
589 * - A query for a record type other than AAAA.
590 * - CD FLAG was set on querier
591 * - An AAAA query for which an error was returned.(qstate.return_rcode)
592 * -> treated as servfail thus synthesize (sec 5.1.3 6147), thus
593 * synthesize in (sec 5.1.2 of RFC6147).
594 * - A successful AAAA query with an answer.
596 if((enum dns64_qstate)qstate->minfo[id] != DNS64_INTERNAL_QUERY
597 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA
598 && !(qstate->query_flags & BIT_CD)
599 && !(qstate->return_msg &&
600 qstate->return_msg->rep &&
601 reply_find_answer_rrset(&qstate->qinfo,
602 qstate->return_msg->rep)))
603 /* not internal, type AAAA, not CD, and no answer RRset,
604 * So, this is a AAAA noerror/nodata answer */
605 return generate_type_A_query(qstate, id);
607 if((enum dns64_qstate)qstate->minfo[id] != DNS64_INTERNAL_QUERY
608 && qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA
609 && !(qstate->query_flags & BIT_CD)
610 && dns64_always_synth_for_qname(qstate, id)) {
611 /* if it is not internal, AAAA, not CD and listed domain,
612 * generate from A record and ignore AAAA */
613 verbose(VERB_ALGO, "dns64: ignore-aaaa and synthesize anyway");
614 return generate_type_A_query(qstate, id);
618 return module_finished;
622 * This is the module's main() function. It gets called each time a query
623 * receives an event which we may need to handle. We respond by updating the
624 * state of the query.
626 * \param qstate Structure containing the state of the query.
627 * \param event Event that has just been received.
628 * \param id This module's instance ID.
629 * \param outbound State of a DNS query on an authoritative server. We never do
630 * our own queries ourselves (other modules do it for us), so
634 dns64_operate(struct module_qstate* qstate, enum module_ev event, int id,
635 struct outbound_entry* outbound)
638 verbose(VERB_QUERY, "dns64[module %d] operate: extstate:%s event:%s",
639 id, strextstate(qstate->ext_state[id]),
640 strmodulevent(event));
641 log_query_info(VERB_QUERY, "dns64 operate: query", &qstate->qinfo);
644 case module_event_new:
645 /* Tag this query as being new and fall through. */
646 qstate->minfo[id] = (void*)DNS64_NEW_QUERY;
648 case module_event_pass:
649 qstate->ext_state[id] = handle_event_pass(qstate, id);
651 case module_event_moddone:
652 qstate->ext_state[id] = handle_event_moddone(qstate, id);
655 qstate->ext_state[id] = module_finished;
661 dns64_synth_aaaa_data(const struct ub_packed_rrset_key* fk,
662 const struct packed_rrset_data* fd,
663 struct ub_packed_rrset_key *dk,
664 struct packed_rrset_data **dd_out, struct regional *region,
665 struct dns64_env* dns64_env )
667 struct packed_rrset_data *dd;
670 * Create synthesized AAAA RR set data. We need to allocated extra memory
671 * for the RRs themselves. Each RR has a length, TTL, pointer to wireformat
672 * data, 2 bytes of data length, and 16 bytes of IPv6 address.
674 if(fd->count > RR_COUNT_MAX) {
676 return; /* integer overflow protection in alloc */
678 if (!(dd = *dd_out = regional_alloc(region,
679 sizeof(struct packed_rrset_data)
680 + fd->count * (sizeof(size_t) + sizeof(time_t) +
681 sizeof(uint8_t*) + 2 + 16)))) {
682 log_err("out of memory");
686 /* Copy attributes from A RR set. */
688 dd->count = fd->count;
690 dd->trust = fd->trust;
691 dd->security = fd->security;
694 * Synthesize AAAA records. Adjust pointers in structure.
697 (size_t*)((uint8_t*)dd + sizeof(struct packed_rrset_data));
698 dd->rr_data = (uint8_t**)&dd->rr_len[dd->count];
699 dd->rr_ttl = (time_t*)&dd->rr_data[dd->count];
700 for(i = 0; i < fd->count; ++i) {
701 if (fd->rr_len[i] != 6 || fd->rr_data[i][0] != 0
702 || fd->rr_data[i][1] != 4) {
708 (uint8_t*)&dd->rr_ttl[dd->count] + 18*i;
709 dd->rr_data[i][0] = 0;
710 dd->rr_data[i][1] = 16;
712 ((struct sockaddr_in6*)&dns64_env->prefix_addr)->sin6_addr.s6_addr,
713 dns64_env->prefix_net, &fd->rr_data[i][2],
714 &dd->rr_data[i][2] );
715 dd->rr_ttl[i] = fd->rr_ttl[i];
719 * Create synthesized AAAA RR set key. This is mostly just bookkeeping,
720 * nothing interesting here.
728 dk->rk.dname = (uint8_t*)regional_alloc_init(region,
729 fk->rk.dname, fk->rk.dname_len);
732 log_err("out of memory");
737 dk->rk.type = htons(LDNS_RR_TYPE_AAAA);
738 memset(&dk->entry, 0, sizeof(dk->entry));
740 dk->entry.hash = rrset_key_hash(&dk->rk);
746 * Synthesize an AAAA RR set from an A sub-query's answer and add it to the
747 * original empty response.
749 * \param id This module's instance ID.
750 * \param super Original AAAA query.
751 * \param qstate A query.
754 dns64_adjust_a(int id, struct module_qstate* super, struct module_qstate* qstate)
756 struct dns64_env* dns64_env = (struct dns64_env*)super->env->modinfo[id];
757 struct reply_info *rep, *cp;
759 struct packed_rrset_data* fd, *dd;
760 struct ub_packed_rrset_key* fk, *dk;
762 verbose(VERB_ALGO, "converting A answers to AAAA answers");
764 log_assert(super->region);
765 log_assert(qstate->return_msg);
766 log_assert(qstate->return_msg->rep);
768 /* If dns64-synthall is enabled, return_msg is not initialized */
769 if(!super->return_msg) {
770 super->return_msg = (struct dns_msg*)regional_alloc(
771 super->region, sizeof(struct dns_msg));
772 if(!super->return_msg)
774 memset(super->return_msg, 0, sizeof(*super->return_msg));
775 super->return_msg->qinfo = super->qinfo;
778 rep = qstate->return_msg->rep;
781 * Build the actual reply.
783 cp = construct_reply_info_base(super->region, rep->flags, rep->qdcount,
784 rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl,
785 rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
786 rep->rrset_count, rep->security);
790 /* allocate ub_key structures special or not */
791 if(!reply_info_alloc_rrset_keys(cp, NULL, super->region)) {
795 /* copy everything and replace A by AAAA */
796 for(i=0; i<cp->rrset_count; i++) {
799 fd = (struct packed_rrset_data*)fk->entry.data;
803 if(i<rep->an_numrrsets && fk->rk.type == htons(LDNS_RR_TYPE_A)) {
804 /* also sets dk->entry.hash */
805 dns64_synth_aaaa_data(fk, fd, dk, &dd, super->region, dns64_env);
808 /* Delete negative AAAA record from cache stored by
809 * the iterator module */
810 rrset_cache_remove(super->env->rrset_cache, dk->rk.dname,
811 dk->rk.dname_len, LDNS_RR_TYPE_AAAA,
812 LDNS_RR_CLASS_IN, 0);
813 /* Delete negative AAAA in msg cache for CNAMEs,
814 * stored by the iterator module */
815 if(i != 0) /* if not the first RR */
816 msg_cache_remove(super->env, dk->rk.dname,
817 dk->rk.dname_len, LDNS_RR_TYPE_AAAA,
818 LDNS_RR_CLASS_IN, 0);
820 dk->entry.hash = fk->entry.hash;
821 dk->rk.dname = (uint8_t*)regional_alloc_init(super->region,
822 fk->rk.dname, fk->rk.dname_len);
827 s = packed_rrset_sizeof(fd);
828 dd = (struct packed_rrset_data*)regional_alloc_init(
829 super->region, fd, s);
835 packed_rrset_ptr_fixup(dd);
836 dk->entry.data = (void*)dd;
839 /* Commit changes. */
840 super->return_msg->rep = cp;
844 * Generate a response for the original IPv6 PTR query based on an IPv4 PTR
845 * sub-query's response.
847 * \param qstate IPv4 PTR sub-query.
848 * \param super Original IPv6 PTR query.
851 dns64_adjust_ptr(struct module_qstate* qstate, struct module_qstate* super)
853 struct ub_packed_rrset_key* answer;
855 verbose(VERB_ALGO, "adjusting PTR reply");
857 /* Copy the sub-query's reply to the parent. */
858 if (!(super->return_msg = (struct dns_msg*)regional_alloc(super->region,
859 sizeof(struct dns_msg))))
861 super->return_msg->qinfo = super->qinfo;
862 super->return_msg->rep = reply_info_copy(qstate->return_msg->rep, NULL,
866 * Adjust the domain name of the answer RR set so that it matches the
867 * initial query's domain name.
869 answer = reply_find_answer_rrset(&qstate->qinfo, super->return_msg->rep);
871 answer->rk.dname = super->qinfo.qname;
872 answer->rk.dname_len = super->qinfo.qname_len;
876 * This function is called when a sub-query finishes to inform the parent query.
878 * We issue two kinds of sub-queries: PTR and A.
880 * \param qstate State of the sub-query.
881 * \param id This module's instance ID.
882 * \param super State of the super-query.
885 dns64_inform_super(struct module_qstate* qstate, int id,
886 struct module_qstate* super)
888 log_query_info(VERB_ALGO, "dns64: inform_super, sub is",
890 log_query_info(VERB_ALGO, "super is", &super->qinfo);
893 * Signal that the sub-query is finished, no matter whether we are
894 * successful or not. This lets the state machine terminate.
896 super->minfo[id] = (void*)DNS64_SUBQUERY_FINISHED;
898 /* If there is no successful answer, we're done. */
899 if (qstate->return_rcode != LDNS_RCODE_NOERROR
900 || !qstate->return_msg
901 || !qstate->return_msg->rep
902 || !reply_find_answer_rrset(&qstate->qinfo,
903 qstate->return_msg->rep))
906 /* Use return code from A query in response to client. */
907 if (super->return_rcode != LDNS_RCODE_NOERROR)
908 super->return_rcode = qstate->return_rcode;
910 /* Generate a response suitable for the original query. */
911 if (qstate->qinfo.qtype == LDNS_RR_TYPE_A) {
912 dns64_adjust_a(id, super, qstate);
914 log_assert(qstate->qinfo.qtype == LDNS_RR_TYPE_PTR);
915 dns64_adjust_ptr(qstate, super);
918 /* Store the generated response in cache. */
919 if (!super->no_cache_store &&
920 !dns_cache_store(super->env, &super->qinfo, super->return_msg->rep,
921 0, 0, 0, NULL, super->query_flags))
922 log_err("out of memory");
926 * Clear module-specific data from query state. Since we do not allocate memory,
927 * it's just a matter of setting a pointer to NULL.
929 * \param qstate Query state.
930 * \param id This module's instance ID.
933 dns64_clear(struct module_qstate* qstate, int id)
935 qstate->minfo[id] = NULL;
939 * Returns the amount of global memory that this module uses, not including
942 * \param env Module environment.
943 * \param id This module's instance ID.
946 dns64_get_mem(struct module_env* env, int id)
948 struct dns64_env* dns64_env = (struct dns64_env*)env->modinfo[id];
951 return sizeof(*dns64_env);
955 * The dns64 function block.
957 static struct module_func_block dns64_block = {
959 &dns64_init, &dns64_deinit, &dns64_operate, &dns64_inform_super,
960 &dns64_clear, &dns64_get_mem
964 * Function for returning the above function block.
966 struct module_func_block *
967 dns64_get_funcblock(void)