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,  /* Item has been authenticated */
  19         DNS_ANSWER_CACHEABLE     = 2,  /* Item is subject to caching */
  20         DNS_ANSWER_SHARED_OWNER  = 4,  /* For mDNS: RRset may be owner by multiple peers */
  21         DNS_ANSWER_CACHE_FLUSH   = 8,  /* For mDNS: sets cache-flush bit in the rrclass of response records */
  22         DNS_ANSWER_GOODBYE       = 16, /* 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_rr(DnsAnswer *a, DnsResourceRecord *rr, DnsAnswerFlags *combined_flags);
  47 int dns_answer_contains_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags);
  48 int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a);
  49 int dns_answer_contains_zone_nsec3(DnsAnswer *answer, const char *zone);
  50
  51 int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags);
  52 int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags);
  53
  54 int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret);
  55 int dns_answer_extend(DnsAnswer **a, DnsAnswer *b);
  56
  57 void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local);
  58
  59 int dns_answer_reserve(DnsAnswer **a, size_t n_free);
  60 int dns_answer_reserve_or_clone(DnsAnswer **a, size_t n_free);
  61
  62 int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key);
  63 int dns_answer_remove_by_rr(DnsAnswer **a, DnsResourceRecord *rr);
  64
  65 int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key, DnsAnswerFlags or_flags);
  66 int dns_answer_move_by_key(DnsAnswer **to, DnsAnswer **from, const DnsResourceKey *key, DnsAnswerFlags or_flags);
  67
  68 bool dns_answer_has_dname_for_cname(DnsAnswer *a, DnsResourceRecord *cname);
  69
  70 static inline size_t dns_answer_size(DnsAnswer *a) {
  71         return a ? a->n_rrs : 0;
  72 }
  73
  74 static inline bool dns_answer_isempty(DnsAnswer *a) {
  75         return dns_answer_size(a) <= 0;
  76 }
  77
  78 void dns_answer_dump(DnsAnswer *answer, FILE *f);
  79
  80 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref);
  81
  82 #define _DNS_ANSWER_FOREACH(q, kk, a)                                   \
  83         for (size_t UNIQ_T(i, q) = ({                                   \
  84                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
  85                                 0;                                      \
  86                         });                                             \
  87              (a) && (UNIQ_T(i, q) < (a)->n_rrs);                        \
  88              UNIQ_T(i, q)++, (kk) = (UNIQ_T(i, q) < (a)->n_rrs ? (a)->items[UNIQ_T(i, q)].rr : NULL))
  89
  90 #define DNS_ANSWER_FOREACH(kk, a) _DNS_ANSWER_FOREACH(UNIQ, kk, a)
  91
  92 #define _DNS_ANSWER_FOREACH_IFINDEX(q, kk, ifi, a)                      \
  93         for (size_t UNIQ_T(i, q) = ({                                   \
  94                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
  95                                 (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \
  96                                 0;                                      \
  97                         });                                             \
  98              (a) && (UNIQ_T(i, q) < (a)->n_rrs);                        \
  99              UNIQ_T(i, q)++,                                            \
 100                      (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \
 101                      (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0))
 102
 103 #define DNS_ANSWER_FOREACH_IFINDEX(kk, ifindex, a) _DNS_ANSWER_FOREACH_IFINDEX(UNIQ, kk, ifindex, a)
 104
 105 #define _DNS_ANSWER_FOREACH_FLAGS(q, kk, fl, a)                         \
 106         for (size_t UNIQ_T(i, q) = ({                                   \
 107                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
 108                                 (fl) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].flags : 0; \
 109                                 0;                                      \
 110                         });                                             \
 111              (a) && (UNIQ_T(i, q) < (a)->n_rrs);                        \
 112              UNIQ_T(i, q)++,                                            \
 113                      (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \
 114                      (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0))
 115
 116 #define DNS_ANSWER_FOREACH_FLAGS(kk, flags, a) _DNS_ANSWER_FOREACH_FLAGS(UNIQ, kk, flags, a)
 117
 118 #define _DNS_ANSWER_FOREACH_FULL(q, kk, ifi, fl, a)                     \
 119         for (size_t UNIQ_T(i, q) = ({                                   \
 120                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
 121                                 (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \
 122                                 (fl) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].flags : 0; \
 123                                 0;                                      \
 124                         });                                             \
 125              (a) && (UNIQ_T(i, q) < (a)->n_rrs);                        \
 126              UNIQ_T(i, q)++,                                            \
 127                      (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \
 128                      (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0), \
 129                      (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0))
 130
 131 #define DNS_ANSWER_FOREACH_FULL(kk, ifindex, flags, a) _DNS_ANSWER_FOREACH_FULL(UNIQ, kk, ifindex, flags, a)