aboutsummaryrefslogtreecommitdiffstats
path: root/src/vnet/dns/dns.h
blob: c55c6f31934641e0ab3467a2bee0208e9ac9df4d (plain)
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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef included_dns_h
#define included_dns_h

#include <vppinfra/time.h>
#include <vppinfra/cache.h>
#include <vppinfra/error.h>

#include <vppinfra/hash.h>
#include <vnet/dns/dns_packet.h>
#include <vnet/ip/ip.h>

typedef struct
{
  /** flags */
  volatile u8 flags;

  /** The name in "normal human being" notation, e.g. www.foobar.com */
  u8 *name;

  /** For CNAME records, the "next name" to resolve */
  u8 *cname;

  /** Expiration time */
  f64 expiration_time;

  /** Cached dns request, for sending retries */
  u8 *dns_request;

  /** Retry parameters */
  int retry_count;
  int server_rotor;
  int server_af;
  f64 retry_timer;

  /** Cached dns response */
  u8 *dns_response;

  /** Clients awaiting responses */
  u32 *api_clients_to_notify;
  u32 *api_client_contexts;
  ip4_address_t *ip4_peers_to_notify;
  ip6_address_t *ip6_peers_to_notify;
} dns_cache_entry_t;

#define DNS_CACHE_ENTRY_FLAG_VALID	(1<<0) /**< we have Actual Data */
#define DNS_CACHE_ENTRY_FLAG_STATIC	(1<<1) /**< static entry */
#define DNS_CACHE_ENTRY_FLAG_CNAME	(1<<2) /**< CNAME (indirect) entry */

#define DNS_RETRIES_PER_SERVER 3

#define DNS_RESOLVER_EVENT_RESOLVED	1
#define DNS_RESOLVER_EVENT_PENDING	2


typedef struct
{
  /** Pool of cache entries */
  dns_cache_entry_t *entries;

  /** Pool indices of unresolved entries */
  u32 *unresolved_entries;

  /** Find cached record by name */
  uword *cache_entry_by_name;
  uword *cache_lock;

  /** enable / disable flag */
  int is_enabled;

  /** upstream name servers, e.g. 8.8.8.8 */
  ip4_address_t *ip4_name_servers;
  ip6_address_t *ip6_name_servers;

  /** config parameters */
  u32 name_cache_size;
  u32 max_ttl_in_seconds;
  u32 random_seed;

  /* convenience */
  vlib_main_t *vlib_main;
  vnet_main_t *vnet_main;
} dns_main_t;

extern dns_main_t dns_main;

extern vlib_node_registration_t dns46_reply_node;
extern vlib_node_registration_t dns_resolver_node;

#define foreach_dns46_reply_error                       \
_(PROCESSED, "DNS reply pkts processed")                \
_(NO_ELT, "No DNS pool element")                        \
_(FORMAT_ERROR, "DNS format errors")                    \
_(TEST_DROP, "DNS reply pkt dropped for test purposes")

typedef enum
{
#define _(sym,str) DNS46_REPLY_ERROR_##sym,
  foreach_dns46_reply_error
#undef _
    DNS46_REPLY_N_ERROR,
} dns46_reply_error_t;

void vnet_send_dns_request (dns_main_t * dm, dns_cache_entry_t * ep);
int
vnet_dns_cname_indirection_nolock (dns_main_t * dm, u32 ep_index, u8 * reply);

int vnet_dns_delete_entry_by_index_nolock (dns_main_t * dm, u32 index);

format_function_t format_dns_reply;

static inline void
dns_cache_lock (dns_main_t * dm)
{
  if (dm->cache_lock)
    {
      while (__sync_lock_test_and_set (dm->cache_lock, 1))
	;
    }
}

static inline void
dns_cache_unlock (dns_main_t * dm)
{
  if (dm->cache_lock)
    {
      CLIB_MEMORY_BARRIER ();
      *dm->cache_lock = 0;
    }
}

#endif /* included_dns_h */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */