src/resolve/resolved-dns-answer.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include "ordered-set.h"
   5 #include "resolved-forward.h"
   6
   7 /* A simple array of resource records. We keep track of the originating ifindex for each RR where that makes
   8  * sense, so that we can qualify A and AAAA RRs referring to a local link with the right ifindex.
   9  *
  10  * Note that we usually encode the empty DnsAnswer object as a simple NULL. */
  11
  12 typedef enum DnsAnswerFlags {
  13         DNS_ANSWER_AUTHENTICATED       = 1 << 0, /* Item has been authenticated */
  14         DNS_ANSWER_CACHEABLE           = 1 << 1, /* Item is subject to caching */
  15         DNS_ANSWER_SHARED_OWNER        = 1 << 2, /* For mDNS: RRset may be owner by multiple peers */
  16         DNS_ANSWER_CACHE_FLUSH         = 1 << 3, /* For mDNS: sets cache-flush bit in the rrclass of response records */
  17         DNS_ANSWER_GOODBYE             = 1 << 4, /* For mDNS: item is subject to disappear */
  18         DNS_ANSWER_SECTION_ANSWER      = 1 << 5, /* When parsing: RR originates from answer section */
  19         DNS_ANSWER_SECTION_AUTHORITY   = 1 << 6, /* When parsing: RR originates from authority section */
  20         DNS_ANSWER_SECTION_ADDITIONAL  = 1 << 7, /* When parsing: RR originates from additional section */
  21         DNS_ANSWER_REFUSE_TTL_NO_MATCH = 1 << 8, /* For mDNS; refuse to merge a zero TTL RR with a nonzero TTL RR */
  22
  23         DNS_ANSWER_MASK_SECTIONS      = DNS_ANSWER_SECTION_ANSWER|
  24                                         DNS_ANSWER_SECTION_AUTHORITY|
  25                                         DNS_ANSWER_SECTION_ADDITIONAL,
  26 } DnsAnswerFlags;
  27
  28 typedef struct DnsAnswerItem {
  29         unsigned n_ref;
  30         DnsResourceRecord *rr;
  31         DnsResourceRecord *rrsig; /* Optionally, also store RRSIG RR that successfully validates this item */
  32         int ifindex;
  33         DnsAnswerFlags flags;
  34 } DnsAnswerItem;
  35
  36 typedef struct DnsAnswer {
  37         unsigned n_ref;
  38         OrderedSet *items;
  39 } DnsAnswer;
  40
  41 DnsAnswer *dns_answer_new(size_t n);
  42 DnsAnswer *dns_answer_ref(DnsAnswer *a);
  43 DnsAnswer *dns_answer_unref(DnsAnswer *a);
  44
  45 #define DNS_ANSWER_REPLACE(a, b)                \
  46         do {                                    \
  47                 typeof(a)* _a = &(a);           \
  48                 typeof(b) _b = (b);             \
  49                 dns_answer_unref(*_a);          \
  50                 *_a = _b;                       \
  51         } while(0)
  52
  53 int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags, DnsResourceRecord *rrsig);
  54 int dns_answer_add_extend(DnsAnswer **a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags, DnsResourceRecord *rrsig);
  55 int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl, int ifindex);
  56
  57 int dns_answer_match_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *ret_flags);
  58 bool dns_answer_contains_nsec_or_nsec3(DnsAnswer *a);
  59 int dns_answer_contains_zone_nsec3(DnsAnswer *answer, const char *zone);
  60 bool dns_answer_contains(DnsAnswer *answer, DnsResourceRecord *rr);
  61
  62 int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *ret_flags);
  63 int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *ret_flags);
  64
  65 int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret);
  66 int dns_answer_extend(DnsAnswer **a, DnsAnswer *b);
  67
  68 void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local);
  69
  70 int dns_answer_reserve(DnsAnswer **a, size_t n_free);
  71 int dns_answer_reserve_or_clone(DnsAnswer **a, size_t n_free);
  72
  73 int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key);
  74 int dns_answer_remove_by_rr(DnsAnswer **a, DnsResourceRecord *rr);
  75 int dns_answer_remove_by_answer_keys(DnsAnswer **a, DnsAnswer *b);
  76
  77 int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key, DnsAnswerFlags or_flags, DnsResourceRecord *rrsig);
  78 int dns_answer_move_by_key(DnsAnswer **to, DnsAnswer **from, const DnsResourceKey *key, DnsAnswerFlags or_flags, DnsResourceRecord *rrsig);
  79
  80 int dns_answer_has_dname_for_cname(DnsAnswer *a, DnsResourceRecord *cname);
  81
  82 static inline size_t dns_answer_size(DnsAnswer *a) {
  83         return a ? ordered_set_size(a->items) : 0;
  84 }
  85
  86 static inline bool dns_answer_isempty(DnsAnswer *a) {
  87         return dns_answer_size(a) <= 0;
  88 }
  89
  90 void dns_answer_dump(DnsAnswer *answer, FILE *f);
  91
  92 void dns_answer_randomize(DnsAnswer *a);
  93
  94 uint32_t dns_answer_min_ttl(DnsAnswer *a);
  95
  96 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref);
  97
  98 typedef struct DnsAnswerIterator {
  99         Iterator iterator;
 100         DnsAnswer *answer;
 101         DnsAnswerItem *item;
 102 } DnsAnswerIterator;
 103
 104 #define _DNS_ANSWER_FOREACH(kk, a, i)                                   \
 105         for (DnsAnswerIterator i = { .iterator = ITERATOR_FIRST, .answer = (a) };  \
 106              i.answer &&                                                \
 107              ordered_set_iterate(i.answer->items, &i.iterator, (void**) &(i.item)) && \
 108              (kk = i.item->rr, true); )
 109
 110 #define DNS_ANSWER_FOREACH(rr, a) _DNS_ANSWER_FOREACH(rr, a, UNIQ_T(i, UNIQ))
 111
 112 #define _DNS_ANSWER_FOREACH_IFINDEX(kk, ifi, a, i)                      \
 113         for (DnsAnswerIterator i = { .iterator = ITERATOR_FIRST, .answer = (a) };  \
 114              i.answer &&                                                \
 115              ordered_set_iterate(i.answer->items, &i.iterator, (void**) &(i.item)) && \
 116              (kk = i.item->rr, ifi = i.item->ifindex, true); )
 117
 118 #define DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, a) _DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, a, UNIQ_T(i, UNIQ))
 119
 120 #define _DNS_ANSWER_FOREACH_FLAGS(kk, fl, a, i)                         \
 121         for (DnsAnswerIterator i = { .iterator = ITERATOR_FIRST, .answer = (a) };  \
 122              i.answer &&                                                \
 123              ordered_set_iterate(i.answer->items, &i.iterator, (void**) &(i.item)) && \
 124              (kk = i.item->rr, fl = i.item->flags, true); )
 125
 126 #define DNS_ANSWER_FOREACH_FLAGS(rr, flags, a) _DNS_ANSWER_FOREACH_FLAGS(rr, flags, a, UNIQ_T(i, UNIQ))
 127
 128 #define _DNS_ANSWER_FOREACH_ITEM(it, a, i)                            \
 129         for (DnsAnswerIterator i = { .iterator = ITERATOR_FIRST, .answer = (a) };  \
 130              i.answer &&                                                \
 131              ordered_set_iterate(i.answer->items, &i.iterator, (void**) &(i.item)) && \
 132              (it = i.item, true); )
 133
 134 #define DNS_ANSWER_FOREACH_ITEM(item, a) _DNS_ANSWER_FOREACH_ITEM(item, a, UNIQ_T(i, UNIQ))