src/resolve/resolved-dns-answer.h

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