src/resolve/resolved-dns-query.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include "in-addr-util.h"
   5 #include "list.h"
   6 #include "resolved-dns-packet.h"
   7 #include "resolved-dns-transaction.h"
   8 #include "resolved-forward.h"
   9
  10 typedef struct DnsQueryCandidate {
  11         unsigned n_ref;
  12         int error_code;
  13         uint64_t generation;
  14
  15         DnsQuery *query;
  16         DnsScope *scope;
  17
  18         DnsSearchDomain *search_domain;
  19
  20         Set *transactions;
  21         sd_event_source *timeout_event_source;
  22
  23         LIST_FIELDS(DnsQueryCandidate, candidates_by_query);
  24         LIST_FIELDS(DnsQueryCandidate, candidates_by_scope);
  25 } DnsQueryCandidate;
  26
  27 typedef struct DnsQuery {
  28         Manager *manager;
  29
  30         /* The question, formatted in IDNA for use on classic DNS, and as UTF8 for use in LLMNR or mDNS. Note
  31          * that even on classic DNS some labels might use UTF8 encoding. Specifically, DNS-SD service names
  32          * (in contrast to their domain suffixes) use UTF-8 encoding even on DNS. Thus, the difference
  33          * between these two fields is mostly relevant only for explicit *hostname* lookups as well as the
  34          * domain suffixes of service lookups.
  35          *
  36          * Note that questions may consist of multiple RR keys at once, but they must be for the same domain
  37          * name. This is used for A+AAAA and TXT+SRV lookups: we'll allocate a single DnsQuery object for
  38          * them instead of two separate ones. That allows us minor optimizations with response handling:
  39          * CNAME/DNAMEs of the first reply we get can already be used to follow the CNAME/DNAME chain for
  40          * both, and we can take benefit of server replies that oftentimes put A responses into AAAA queries
  41          * and vice versa (in the additional section). */
  42         DnsQuestion *question_idna;
  43         DnsQuestion *question_utf8;
  44
  45         /* If this is not a question by ourselves, but a "bypass" request, we propagate the original packet
  46          * here, and use that instead. */
  47         DnsPacket *question_bypass;
  48
  49         /* When we follow a CNAME redirect, we save the original question here, for informational/monitoring
  50          * purposes. We'll keep adding to this whenever we go one step in the redirect, so that in the end
  51          * this will contain the complete set of CNAME questions. */
  52         DnsQuestion *collected_questions;
  53
  54         uint64_t flags;
  55         int ifindex;
  56
  57         /* When resolving a service, we first create a TXT+SRV query, and then for the hostnames we discover
  58          * auxiliary A+AAAA queries. This pointer always points from the auxiliary queries back to the
  59          * TXT+SRV query. */
  60         int auxiliary_result;
  61         DnsQuery *auxiliary_for;
  62         LIST_HEAD(DnsQuery, auxiliary_queries);
  63
  64         LIST_HEAD(DnsQueryCandidate, candidates);
  65         sd_event_source *timeout_event_source;
  66
  67         /* Discovered data */
  68         DnsAnswer *answer;
  69         int answer_rcode;
  70         int answer_ede_rcode;
  71         char *answer_ede_msg;
  72         DnssecResult answer_dnssec_result;
  73         uint64_t answer_query_flags;
  74         DnsProtocol answer_protocol;
  75         int answer_family;
  76         DnsPacket *answer_full_packet;
  77         DnsSearchDomain *answer_search_domain;
  78
  79         DnsTransactionState state;
  80         int answer_errno; /* if state is DNS_TRANSACTION_ERRNO */
  81
  82         unsigned block_ready;
  83
  84         uint8_t n_auxiliary_queries;
  85         uint8_t n_cname_redirects;
  86
  87         bool previous_redirect_unauthenticated:1;
  88         bool previous_redirect_non_confidential:1;
  89         bool previous_redirect_non_synthetic:1;
  90         bool request_address_valid:1;
  91
  92         /* Bus + Varlink client information */
  93         sd_bus_message *bus_request;
  94         sd_varlink *varlink_request;
  95         int request_family;
  96         union in_addr_union request_address;
  97         unsigned block_all_complete;
  98         char *request_address_string;
  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 } DnsQuery;
 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 int validate_and_mangle_query_flags(Manager *manager, uint64_t *flags, const char *name, uint64_t ok);
 155
 156 uint64_t dns_query_reply_flags_make(DnsQuery *q);