src/resolve/resolved-dns-answer.h

   1 #pragma once
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2014 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 typedef struct DnsAnswer DnsAnswer;
  23 typedef struct DnsAnswerItem DnsAnswerItem;
  24
  25 #include "macro.h"
  26 #include "resolved-dns-rr.h"
  27
  28 /* A simple array of resource records. We keep track of the
  29  * originating ifindex for each RR where that makes sense, so that we
  30  * can qualify A and AAAA RRs referring to a local link with the
  31  * right ifindex.
  32  *
  33  * Note that we usually encode the empty DnsAnswer object as a simple NULL. */
  34
  35 typedef enum DnsAnswerFlags {
  36         DNS_ANSWER_AUTHENTICATED = 1, /* Item has been authenticated */
  37         DNS_ANSWER_CACHEABLE     = 2, /* Item is subject to caching */
  38         DNS_ANSWER_SHARED_OWNER  = 4, /* For mDNS: RRset may be owner by multiple peers */
  39 } DnsAnswerFlags;
  40
  41 struct DnsAnswerItem {
  42         DnsResourceRecord *rr;
  43         int ifindex;
  44         DnsAnswerFlags flags;
  45 };
  46
  47 struct DnsAnswer {
  48         unsigned n_ref;
  49         unsigned n_rrs, n_allocated;
  50         DnsAnswerItem items[0];
  51 };
  52
  53 DnsAnswer *dns_answer_new(unsigned n);
  54 DnsAnswer *dns_answer_ref(DnsAnswer *a);
  55 DnsAnswer *dns_answer_unref(DnsAnswer *a);
  56
  57 int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags);
  58 int dns_answer_add_extend(DnsAnswer **a, DnsResourceRecord *rr, int ifindex, DnsAnswerFlags flags);
  59 int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl, int ifindex);
  60
  61 int dns_answer_match_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags);
  62 int dns_answer_contains_rr(DnsAnswer *a, DnsResourceRecord *rr, DnsAnswerFlags *combined_flags);
  63 int dns_answer_contains_key(DnsAnswer *a, const DnsResourceKey *key, DnsAnswerFlags *combined_flags);
  64 int dns_answer_contains_nsec_or_nsec3(DnsAnswer *a);
  65 int dns_answer_contains_zone_nsec3(DnsAnswer *answer, const char *zone);
  66
  67 int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags);
  68 int dns_answer_find_cname_or_dname(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret, DnsAnswerFlags *flags);
  69
  70 int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret);
  71 int dns_answer_extend(DnsAnswer **a, DnsAnswer *b);
  72
  73 void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local);
  74
  75 int dns_answer_reserve(DnsAnswer **a, unsigned n_free);
  76 int dns_answer_reserve_or_clone(DnsAnswer **a, unsigned n_free);
  77
  78 int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key);
  79 int dns_answer_remove_by_rr(DnsAnswer **a, DnsResourceRecord *rr);
  80
  81 int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key, DnsAnswerFlags or_flags);
  82 int dns_answer_move_by_key(DnsAnswer **to, DnsAnswer **from, const DnsResourceKey *key, DnsAnswerFlags or_flags);
  83
  84 bool dns_answer_has_dname_for_cname(DnsAnswer *a, DnsResourceRecord *cname);
  85
  86 static inline unsigned dns_answer_size(DnsAnswer *a) {
  87         return a ? a->n_rrs : 0;
  88 }
  89
  90 void dns_answer_dump(DnsAnswer *answer, FILE *f);
  91
  92 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref);
  93
  94 #define _DNS_ANSWER_FOREACH(q, kk, a)                                   \
  95         for (unsigned UNIQ_T(i, q) = ({                                 \
  96                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
  97                                 0;                                      \
  98                         });                                             \
  99              (a) && (UNIQ_T(i, q) < (a)->n_rrs);                        \
 100              UNIQ_T(i, q)++, (kk) = (UNIQ_T(i, q) < (a)->n_rrs ? (a)->items[UNIQ_T(i, q)].rr : NULL))
 101
 102 #define DNS_ANSWER_FOREACH(kk, a) _DNS_ANSWER_FOREACH(UNIQ, kk, a)
 103
 104 #define _DNS_ANSWER_FOREACH_IFINDEX(q, kk, ifi, a)                      \
 105         for (unsigned UNIQ_T(i, q) = ({                                 \
 106                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
 107                                 (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \
 108                                 0;                                      \
 109                         });                                             \
 110              (a) && (UNIQ_T(i, q) < (a)->n_rrs);                        \
 111              UNIQ_T(i, q)++,                                            \
 112                      (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \
 113                      (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0))
 114
 115 #define DNS_ANSWER_FOREACH_IFINDEX(kk, ifindex, a) _DNS_ANSWER_FOREACH_IFINDEX(UNIQ, kk, ifindex, a)
 116
 117 #define _DNS_ANSWER_FOREACH_FLAGS(q, kk, fl, a)                         \
 118         for (unsigned UNIQ_T(i, q) = ({                                 \
 119                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
 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                      (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0))
 127
 128 #define DNS_ANSWER_FOREACH_FLAGS(kk, flags, a) _DNS_ANSWER_FOREACH_FLAGS(UNIQ, kk, flags, a)
 129
 130 #define _DNS_ANSWER_FOREACH_FULL(q, kk, ifi, fl, a)                     \
 131         for (unsigned UNIQ_T(i, q) = ({                                 \
 132                                 (kk) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].rr : NULL; \
 133                                 (ifi) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].ifindex : 0; \
 134                                 (fl) = ((a) && (a)->n_rrs > 0) ? (a)->items[0].flags : 0; \
 135                                 0;                                      \
 136                         });                                             \
 137              (a) && (UNIQ_T(i, q) < (a)->n_rrs);                        \
 138              UNIQ_T(i, q)++,                                            \
 139                      (kk) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].rr : NULL), \
 140                      (ifi) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].ifindex : 0), \
 141                      (fl) = ((UNIQ_T(i, q) < (a)->n_rrs) ? (a)->items[UNIQ_T(i, q)].flags : 0))
 142
 143 #define DNS_ANSWER_FOREACH_FULL(kk, ifindex, flags, a) _DNS_ANSWER_FOREACH_FULL(UNIQ, kk, ifindex, flags, a)