src/resolve/resolved-dns-stream.h

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