1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
#include "sd-event.h"
#include "ordered-set.h"
#include "socket-util.h"
typedef struct DnsServer DnsServer;
typedef struct DnsStream DnsStream;
typedef struct DnsTransaction DnsTransaction;
typedef struct Manager Manager;
typedef struct DnsStubListenerExtra DnsStubListenerExtra;
#include "resolved-dns-packet.h"
#include "resolved-dnstls.h"
/* Various timeouts for establishing TCP connections. First the default time-out for that. */
#define DNS_STREAM_DEFAULT_TIMEOUT_USEC (10 * USEC_PER_SEC)
/* In the DNS stub, be more friendly for incoming connections, than we are to ourselves for outgoing ones */
#define DNS_STREAM_STUB_TIMEOUT_USEC (30 * USEC_PER_SEC)
/* In opportunistic TLS mode, lower timeouts */
#define DNS_STREAM_OPPORTUNISTIC_TLS_TIMEOUT_USEC (3 * USEC_PER_SEC)
/* Once connections are established apply this timeout once nothing happens anymore */
#define DNS_STREAM_ESTABLISHED_TIMEOUT_USEC (10 * USEC_PER_SEC)
typedef enum DnsStreamType {
DNS_STREAM_LOOKUP, /* Outgoing connection to a classic DNS server */
DNS_STREAM_LLMNR_SEND, /* Outgoing LLMNR TCP lookup */
DNS_STREAM_LLMNR_RECV, /* Incoming LLMNR TCP lookup */
DNS_STREAM_STUB, /* Incoming DNS stub connection */
_DNS_STREAM_TYPE_MAX,
_DNS_STREAM_TYPE_INVALID = -EINVAL,
} DnsStreamType;
#define DNS_STREAM_WRITE_TLS_DATA 1
/* Streams are used by three subsystems:
*
* 1. The normal transaction logic when doing a DNS or LLMNR lookup via TCP
* 2. The LLMNR logic when accepting a TCP-based lookup
* 3. The DNS stub logic when accepting a TCP-based lookup
*/
struct DnsStream {
Manager *manager;
unsigned n_ref;
DnsStreamType type;
DnsProtocol protocol;
int fd;
union sockaddr_union peer;
socklen_t peer_salen;
union sockaddr_union local;
socklen_t local_salen;
int ifindex;
uint32_t ttl;
bool identified;
bool packet_received; /* At least one packet is received. Used by LLMNR. */
/* only when using TCP fast open */
union sockaddr_union tfo_address;
socklen_t tfo_salen;
#if ENABLE_DNS_OVER_TLS
DnsTlsStreamData dnstls_data;
int dnstls_events;
#endif
sd_event_source *io_event_source;
sd_event_source *timeout_event_source;
be16_t write_size, read_size;
DnsPacket *write_packet, *read_packet;
size_t n_written, n_read;
OrderedSet *write_queue;
int (*on_packet)(DnsStream *s, DnsPacket *p);
int (*complete)(DnsStream *s, int error);
LIST_HEAD(DnsTransaction, transactions); /* when used by the transaction logic */
DnsServer *server; /* when used by the transaction logic */
Set *queries; /* when used by the DNS stub logic */
/* used when DNS-over-TLS is enabled */
bool encrypted:1;
DnsStubListenerExtra *stub_listener_extra;
LIST_FIELDS(DnsStream, streams);
};
int dns_stream_new(
Manager *m,
DnsStream **ret,
DnsStreamType type,
DnsProtocol protocol,
int fd,
const union sockaddr_union *tfo_address,
int (on_packet)(DnsStream*, DnsPacket*),
int (complete)(DnsStream*, int), /* optional */
usec_t connect_timeout_usec);
#if ENABLE_DNS_OVER_TLS
int dns_stream_connect_tls(DnsStream *s, void *tls_session);
#endif
DnsStream *dns_stream_unref(DnsStream *s);
DnsStream *dns_stream_ref(DnsStream *s);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
int dns_stream_write_packet(DnsStream *s, DnsPacket *p);
ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags);
static inline bool DNS_STREAM_QUEUED(DnsStream *s) {
assert(s);
if (s->fd < 0) /* already stopped? */
return false;
return !!s->write_packet;
}
void dns_stream_detach(DnsStream *s);
|
