src/resolve/resolved-dns-stream.h

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