src/resolve/resolved-dns-query.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include "sd-bus.h"
   5
   6 #include "set.h"
   7 #include "varlink.h"
   8
   9 typedef struct DnsQueryCandidate DnsQueryCandidate;
  10 typedef struct DnsQuery DnsQuery;
  11 typedef struct DnsStubListenerExtra DnsStubListenerExtra;
  12
  13 #include "resolved-dns-answer.h"
  14 #include "resolved-dns-question.h"
  15 #include "resolved-dns-search-domain.h"
  16 #include "resolved-dns-transaction.h"
  17
  18 struct DnsQueryCandidate {
  19         unsigned n_ref;
  20         int error_code;
  21
  22         DnsQuery *query;
  23         DnsScope *scope;
  24
  25         DnsSearchDomain *search_domain;
  26
  27         Set *transactions;
  28
  29         LIST_FIELDS(DnsQueryCandidate, candidates_by_query);
  30         LIST_FIELDS(DnsQueryCandidate, candidates_by_scope);
  31 };
  32
  33 struct DnsQuery {
  34         Manager *manager;
  35
  36         /* The question, formatted in IDNA for use on classic DNS, and as UTF8 for use in LLMNR or mDNS. Note
  37          * that even on classic DNS some labels might use UTF8 encoding. Specifically, DNS-SD service names
  38          * (in contrast to their domain suffixes) use UTF-8 encoding even on DNS. Thus, the difference
  39          * between these two fields is mostly relevant only for explicit *hostname* lookups as well as the
  40          * domain suffixes of service lookups.
  41          *
  42          * Note that questions may consist of multiple RR keys at once, but they must be for the same domain
  43          * name. This is used for A+AAAA and TXT+SRV lookups: we'll allocate a single DnsQuery object for
  44          * them instead of two separate ones. That allows us minor optimizations with response handling:
  45          * CNAME/DNAMEs of the first reply we get can already be used to follow the CNAME/DNAME chain for
  46          * both, and we can take benefit of server replies that oftentimes put A responses into AAAA queries
  47          * and vice versa (in the additional section). */
  48         DnsQuestion *question_idna;
  49         DnsQuestion *question_utf8;
  50
  51         /* If this is not a question by ourselves, but a "bypass" request, we propagate the original packet
  52          * here, and use that instead. */
  53         DnsPacket *question_bypass;
  54
  55         uint64_t flags;
  56         int ifindex;
  57
  58         /* When resolving a service, we first create a TXT+SRV query, and then for the hostnames we discover
  59          * auxiliary A+AAAA queries. This pointer always points from the auxiliary queries back to the
  60          * TXT+SRV query. */
  61         int auxiliary_result;
  62         DnsQuery *auxiliary_for;
  63         LIST_HEAD(DnsQuery, auxiliary_queries);
  64
  65         LIST_HEAD(DnsQueryCandidate, candidates);
  66         sd_event_source *timeout_event_source;
  67
  68         /* Discovered data */
  69         DnsAnswer *answer;
  70         int answer_rcode;
  71         DnssecResult answer_dnssec_result;
  72         uint64_t answer_query_flags;
  73         DnsProtocol answer_protocol;
  74         int answer_family;
  75         DnsPacket *answer_full_packet;
  76         DnsSearchDomain *answer_search_domain;
  77
  78         DnsTransactionState state;
  79         int answer_errno; /* if state is DNS_TRANSACTION_ERRNO */
  80
  81         unsigned block_ready;
  82
  83         uint8_t n_auxiliary_queries;
  84         uint8_t n_cname_redirects;
  85
  86         bool previous_redirect_unauthenticated:1;
  87         bool previous_redirect_non_confidential:1;
  88         bool previous_redirect_non_synthetic:1;
  89         bool request_address_valid:1;
  90
  91         /* Bus + Varlink client information */
  92         sd_bus_message *bus_request;
  93         Varlink *varlink_request;
  94         int request_family;
  95         union in_addr_union request_address;
  96         unsigned block_all_complete;
  97         char *request_address_string;
  98         char *request_name;
  99
 100         /* DNS stub information */
 101         DnsPacket *request_packet;
 102         DnsStream *request_stream;
 103         DnsAnswer *reply_answer;
 104         DnsAnswer *reply_authoritative;
 105         DnsAnswer *reply_additional;
 106         DnsStubListenerExtra *stub_listener_extra;
 107
 108         /* Completion callback */
 109         void (*complete)(DnsQuery* q);
 110
 111         sd_bus_track *bus_track;
 112
 113         LIST_FIELDS(DnsQuery, queries);
 114         LIST_FIELDS(DnsQuery, auxiliary_queries);
 115
 116         /* Note: fields should be ordered to minimize alignment gaps. Use pahole! */
 117 };
 118
 119 enum {
 120         DNS_QUERY_MATCH,
 121         DNS_QUERY_NOMATCH,
 122         DNS_QUERY_CNAME,
 123 };
 124
 125 DnsQueryCandidate* dns_query_candidate_ref(DnsQueryCandidate*);
 126 DnsQueryCandidate* dns_query_candidate_unref(DnsQueryCandidate*);
 127 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQueryCandidate*, dns_query_candidate_unref);
 128
 129 void dns_query_candidate_notify(DnsQueryCandidate *c);
 130
 131 int dns_query_new(Manager *m, DnsQuery **q, DnsQuestion *question_utf8, DnsQuestion *question_idna, DnsPacket *question_bypass, int family, uint64_t flags);
 132 DnsQuery *dns_query_free(DnsQuery *q);
 133
 134 int dns_query_make_auxiliary(DnsQuery *q, DnsQuery *auxiliary_for);
 135
 136 int dns_query_go(DnsQuery *q);
 137 void dns_query_ready(DnsQuery *q);
 138
 139 int dns_query_process_cname_one(DnsQuery *q);
 140 int dns_query_process_cname_many(DnsQuery *q);
 141
 142 void dns_query_complete(DnsQuery *q, DnsTransactionState state);
 143
 144 DnsQuestion* dns_query_question_for_protocol(DnsQuery *q, DnsProtocol protocol);
 145
 146 const char *dns_query_string(DnsQuery *q);
 147
 148 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuery*, dns_query_free);
 149
 150 bool dns_query_fully_authenticated(DnsQuery *q);
 151 bool dns_query_fully_confidential(DnsQuery *q);
 152 bool dns_query_fully_authoritative(DnsQuery *q);
 153
 154 static inline uint64_t dns_query_reply_flags_make(DnsQuery *q) {
 155         assert(q);
 156
 157         return SD_RESOLVED_FLAGS_MAKE(q->answer_protocol,
 158                                       q->answer_family,
 159                                       dns_query_fully_authenticated(q),
 160                                       dns_query_fully_confidential(q)) |
 161                 (q->answer_query_flags & (SD_RESOLVED_FROM_MASK|SD_RESOLVED_SYNTHETIC));
 162 }