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 /* Streams are used by three subsystems:
  19  *
  20  *   1. The normal transaction logic when doing a DNS or LLMNR lookup via TCP
  21  *   2. The LLMNR logic when accepting a TCP-based lookup
  22  *   3. The DNS stub logic when accepting a TCP-based lookup
  23  */
  24
  25 struct DnsStream {
  26         Manager *manager;
  27         int n_ref;
  28
  29         DnsProtocol protocol;
  30
  31         int fd;
  32         union sockaddr_union peer;
  33         socklen_t peer_salen;
  34         union sockaddr_union local;
  35         socklen_t local_salen;
  36         int ifindex;
  37         uint32_t ttl;
  38         bool identified;
  39
  40         /* only when using TCP fast open */
  41         union sockaddr_union tfo_address;
  42         socklen_t tfo_salen;
  43
  44         sd_event_source *io_event_source;
  45         sd_event_source *timeout_event_source;
  46
  47         be16_t write_size, read_size;
  48         DnsPacket *write_packet, *read_packet;
  49         size_t n_written, n_read;
  50         OrderedSet *write_queue;
  51
  52         int (*on_packet)(DnsStream *s);
  53         int (*complete)(DnsStream *s, int error);
  54
  55         LIST_HEAD(DnsTransaction, transactions); /* when used by the transaction logic */
  56         DnsServer *server;                       /* when used by the transaction logic */
  57         DnsQuery *query;             /* when used by the DNS stub logic */
  58
  59         LIST_FIELDS(DnsStream, streams);
  60 };
  61
  62 int dns_stream_new(Manager *m, DnsStream **s, DnsProtocol protocol, int fd, const union sockaddr_union *tfo_address);
  63 DnsStream *dns_stream_unref(DnsStream *s);
  64 DnsStream *dns_stream_ref(DnsStream *s);
  65
  66 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
  67
  68 int dns_stream_write_packet(DnsStream *s, DnsPacket *p);
  69
  70 static inline bool DNS_STREAM_QUEUED(DnsStream *s) {
  71         assert(s);
  72
  73         if (s->fd < 0) /* already stopped? */
  74                 return false;
  75
  76         return !!s->write_packet;
  77 }