src/resolve/resolved-dns-stream.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2014 Lennart Poettering
   8 ***/
   9
  10 #include "socket-util.h"
  11
  12 typedef struct DnsStream DnsStream;
  13
  14 #include "resolved-dns-packet.h"
  15 #include "resolved-dns-transaction.h"
  16 #include "resolved-manager.h"
  17
  18 #if HAVE_GNUTLS
  19 #include <gnutls/gnutls.h>
  20 #endif
  21
  22 /* Streams are used by three subsystems:
  23  *
  24  *   1. The normal transaction logic when doing a DNS or LLMNR lookup via TCP
  25  *   2. The LLMNR logic when accepting a TCP-based lookup
  26  *   3. The DNS stub logic when accepting a TCP-based lookup
  27  */
  28
  29 struct DnsStream {
  30         Manager *manager;
  31         int n_ref;
  32
  33         DnsProtocol protocol;
  34
  35         int fd;
  36         union sockaddr_union peer;
  37         socklen_t peer_salen;
  38         union sockaddr_union local;
  39         socklen_t local_salen;
  40         int ifindex;
  41         uint32_t ttl;
  42         bool identified;
  43
  44         /* only when using TCP fast open */
  45         union sockaddr_union tfo_address;
  46         socklen_t tfo_salen;
  47
  48 #if HAVE_GNUTLS
  49         gnutls_session_t tls_session;
  50         int tls_handshake;
  51         bool tls_bye;
  52 #endif
  53
  54         sd_event_source *io_event_source;
  55         sd_event_source *timeout_event_source;
  56
  57         be16_t write_size, read_size;
  58         DnsPacket *write_packet, *read_packet;
  59         size_t n_written, n_read;
  60         OrderedSet *write_queue;
  61
  62         int (*on_connection)(DnsStream *s);
  63         int (*on_packet)(DnsStream *s);
  64         int (*complete)(DnsStream *s, int error);
  65
  66         LIST_HEAD(DnsTransaction, transactions); /* when used by the transaction logic */
  67         DnsServer *server;                       /* when used by the transaction logic */
  68         DnsQuery *query;             /* when used by the DNS stub logic */
  69
  70         /* used when DNS-over-TLS is enabled */
  71         bool encrypted:1;
  72
  73         LIST_FIELDS(DnsStream, streams);
  74 };
  75
  76 int dns_stream_new(Manager *m, DnsStream **s, DnsProtocol protocol, int fd, const union sockaddr_union *tfo_address);
  77 #if HAVE_GNUTLS
  78 int dns_stream_connect_tls(DnsStream *s, gnutls_session_t tls_session);
  79 #endif
  80 DnsStream *dns_stream_unref(DnsStream *s);
  81 DnsStream *dns_stream_ref(DnsStream *s);
  82
  83 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
  84
  85 int dns_stream_write_packet(DnsStream *s, DnsPacket *p);
  86
  87 static inline bool DNS_STREAM_QUEUED(DnsStream *s) {
  88         assert(s);
  89
  90         if (s->fd < 0) /* already stopped? */
  91                 return false;
  92
  93         return !!s->write_packet;
  94 }