src/resolve/resolved-dns-stream.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include "sd-event.h"
   5
   6 #include "ordered-set.h"
   7 #include "socket-util.h"
   8
   9 typedef struct DnsServer DnsServer;
  10 typedef struct DnsStream DnsStream;
  11 typedef struct DnsTransaction DnsTransaction;
  12 typedef struct Manager Manager;
  13 typedef struct DnsStubListenerExtra DnsStubListenerExtra;
  14
  15 #include "resolved-dns-packet.h"
  16 #include "resolved-dnstls.h"
  17
  18 typedef enum DnsStreamType {
  19         DNS_STREAM_LOOKUP,        /* Outgoing connection to a classic DNS server */
  20         DNS_STREAM_LLMNR_SEND,    /* Outgoing LLMNR TCP lookup */
  21         DNS_STREAM_LLMNR_RECV,    /* Incoming LLMNR TCP lookup */
  22         DNS_STREAM_STUB,          /* Incoming DNS stub connection */
  23         _DNS_STREAM_TYPE_MAX,
  24         _DNS_STREAM_TYPE_INVALID = -1,
  25 } DnsStreamType;
  26
  27 #define DNS_STREAM_WRITE_TLS_DATA 1
  28
  29 /* Streams are used by three subsystems:
  30  *
  31  *   1. The normal transaction logic when doing a DNS or LLMNR lookup via TCP
  32  *   2. The LLMNR logic when accepting a TCP-based lookup
  33  *   3. The DNS stub logic when accepting a TCP-based lookup
  34  */
  35
  36 struct DnsStream {
  37         Manager *manager;
  38         unsigned n_ref;
  39
  40         DnsStreamType type;
  41         DnsProtocol protocol;
  42
  43         int fd;
  44         union sockaddr_union peer;
  45         socklen_t peer_salen;
  46         union sockaddr_union local;
  47         socklen_t local_salen;
  48         int ifindex;
  49         uint32_t ttl;
  50         bool identified;
  51
  52         /* only when using TCP fast open */
  53         union sockaddr_union tfo_address;
  54         socklen_t tfo_salen;
  55
  56 #if ENABLE_DNS_OVER_TLS
  57         DnsTlsStreamData dnstls_data;
  58         int dnstls_events;
  59 #endif
  60
  61         sd_event_source *io_event_source;
  62         sd_event_source *timeout_event_source;
  63
  64         be16_t write_size, read_size;
  65         DnsPacket *write_packet, *read_packet;
  66         size_t n_written, n_read;
  67         OrderedSet *write_queue;
  68
  69         int (*on_packet)(DnsStream *s);
  70         int (*complete)(DnsStream *s, int error);
  71
  72         LIST_HEAD(DnsTransaction, transactions); /* when used by the transaction logic */
  73         DnsServer *server;                       /* when used by the transaction logic */
  74         Set *queries;                            /* when used by the DNS stub logic */
  75
  76         /* used when DNS-over-TLS is enabled */
  77         bool encrypted:1;
  78
  79         DnsStubListenerExtra *stub_listener_extra;
  80
  81         LIST_FIELDS(DnsStream, streams);
  82 };
  83
  84 int dns_stream_new(Manager *m, DnsStream **s, DnsStreamType type, DnsProtocol protocol, int fd, const union sockaddr_union *tfo_address);
  85 #if ENABLE_DNS_OVER_TLS
  86 int dns_stream_connect_tls(DnsStream *s, void *tls_session);
  87 #endif
  88 DnsStream *dns_stream_unref(DnsStream *s);
  89 DnsStream *dns_stream_ref(DnsStream *s);
  90
  91 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
  92
  93 int dns_stream_write_packet(DnsStream *s, DnsPacket *p);
  94 ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags);
  95
  96 static inline bool DNS_STREAM_QUEUED(DnsStream *s) {
  97         assert(s);
  98
  99         if (s->fd < 0) /* already stopped? */
 100                 return false;
 101
 102         return !!s->write_packet;
 103 }
 104
 105 DnsPacket *dns_stream_take_read_packet(DnsStream *s);
 106
 107 void dns_stream_detach(DnsStream *s);