FD.io VPP  v18.07-rc0-415-g6c78436
Vector Packet Processing
dns.h
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2017 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef included_dns_h
17 #define included_dns_h
18 
19 #include <vppinfra/time.h>
20 #include <vppinfra/cache.h>
21 #include <vppinfra/error.h>
22 
23 #include <vppinfra/hash.h>
24 #include <vnet/dns/dns_packet.h>
25 #include <vnet/ip/ip.h>
26 
27 typedef struct
28 {
36  u8 dst_address[16];
37  u8 *name;
39 
40 typedef enum
41 {
47 
48 typedef struct
49 {
50  /** flags */
51  volatile u8 flags;
52 
53  /** The name in "normal human being" notation, e.g. www.foobar.com */
54  u8 *name;
55 
56  /** For CNAME records, the "next name" to resolve */
58 
59  /** Expiration time */
61 
62  /** Cached dns request, for sending retries */
64 
65  /** Retry parameters */
68  int server_af;
71 
72  /** Cached dns response */
74 
75  /** Clients / peers awaiting responses */
78 
79 #define DNS_CACHE_ENTRY_FLAG_VALID (1<<0) /**< we have Actual Data */
80 #define DNS_CACHE_ENTRY_FLAG_STATIC (1<<1) /**< static entry */
81 #define DNS_CACHE_ENTRY_FLAG_CNAME (1<<2) /**< CNAME (indirect) entry */
82 
83 #define DNS_RETRIES_PER_SERVER 3
84 
85 #define DNS_RESOLVER_EVENT_RESOLVED 1
86 #define DNS_RESOLVER_EVENT_PENDING 2
87 
88 
89 typedef struct
90 {
91  /** Pool of cache entries */
93 
94  /** Pool indices of unresolved entries */
96 
97  /** Find cached record by name */
100 
101  /** enable / disable flag */
103 
104  /** upstream name servers, e.g. 8.8.8.8 */
107 
108  /** config parameters */
112 
113  /* convenience */
116 } dns_main_t;
117 
118 extern dns_main_t dns_main;
119 
124 
125 #define foreach_dns46_request_error \
126 _(NONE, "No error") \
127 _(UNIMPLEMENTED, "Unimplemented") \
128 _(PROCESSED, "DNS request pkts processed") \
129 _(IP_OPTIONS, "DNS pkts with ip options (dropped)") \
130 _(BAD_REQUEST, "DNS pkts with serious discrepanices (dropped)") \
131 _(TOO_MANY_REQUESTS, "DNS pkts asking too many questions") \
132 _(RESOLUTION_REQUIRED, "DNS pkts pending upstream name resolution")
133 
134 typedef enum
135 {
136 #define _(sym,str) DNS46_REQUEST_ERROR_##sym,
138 #undef _
141 
142 #define foreach_dns46_reply_error \
143 _(DISABLED, "DNS pkts punted (feature disabled)") \
144 _(PROCESSED, "DNS reply pkts processed") \
145 _(NO_ELT, "No DNS pool element") \
146 _(FORMAT_ERROR, "DNS format errors") \
147 _(TEST_DROP, "DNS reply pkt dropped for test purposes")
148 
149 typedef enum
150 {
151 #define _(sym,str) DNS46_REPLY_ERROR_##sym,
153 #undef _
156 
158 int
159 vnet_dns_cname_indirection_nolock (dns_main_t * dm, u32 ep_index, u8 * reply);
160 
162 
163 int
165  dns_cache_entry_t ** retp);
166 
167 void
169  dns_cache_entry_t * ep, ip6_address_t * server);
170 void
172  dns_cache_entry_t * ep, ip4_address_t * server);
173 
175  dns_cache_entry_t * ep, vlib_buffer_t * b0);
176 
178  dns_cache_entry_t * ep, vlib_buffer_t * b0);
179 
180 u8 *vnet_dns_labels_to_name (u8 * label, u8 * full_text,
181  u8 ** parse_from_here);
182 
184 
185 static inline void
187 {
188  if (dm->cache_lock)
189  {
190  while (__sync_lock_test_and_set (dm->cache_lock, 1))
191  ;
192  }
193 }
194 
195 static inline void
197 {
198  if (dm->cache_lock)
199  {
201  *dm->cache_lock = 0;
202  }
203 }
204 
205 #endif /* included_dns_h */
206 
207 /*
208  * fd.io coding-style-patch-verification: ON
209  *
210  * Local Variables:
211  * eval: (c-set-style "gnu")
212  * End:
213  */
Definition: dns.h:48
void vnet_send_dns4_reply(dns_main_t *dm, dns_pending_request_t *t, dns_cache_entry_t *ep, vlib_buffer_t *b0)
Definition: dns.c:2728
ip6_address_t * ip6_name_servers
Definition: dns.h:106
dns_main_t dns_main
Definition: dns.c:42
u8 * vnet_dns_labels_to_name(u8 *label, u8 *full_text, u8 **parse_from_here)
arc-function for the above.
Definition: dns.c:473
vlib_node_registration_t dns46_reply_node
(constructor) VLIB_REGISTER_NODE (dns46_reply_node)
Definition: reply_node.c:42
void vnet_dns_send_dns4_request(dns_main_t *dm, dns_cache_entry_t *ep, ip4_address_t *server)
Definition: dns.c:201
vlib_node_registration_t dns4_request_node
(constructor) VLIB_REGISTER_NODE (dns4_request_node)
Definition: request_node.c:293
u8 * dns_response
Cached dns response.
Definition: dns.h:73
int retry_count
Retry parameters.
Definition: dns.h:66
int vnet_dns_resolve_name(dns_main_t *dm, u8 *name, dns_pending_request_t *t, dns_cache_entry_t **retp)
Definition: dns.c:784
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
u32 client_context
Definition: dns.h:31
void vnet_dns_send_dns6_request(dns_main_t *dm, dns_cache_entry_t *ep, ip6_address_t *server)
Definition: dns.c:317
unsigned char u8
Definition: types.h:56
double f64
Definition: types.h:142
vlib_main_t * vlib_main
Definition: dns.h:114
u8 * dns_request
Cached dns request, for sending retries.
Definition: dns.h:63
f64 retry_timer
Definition: dns.h:70
u32 * unresolved_entries
Pool indices of unresolved entries.
Definition: dns.h:95
unsigned int u32
Definition: types.h:88
dns_pending_request_t * pending_requests
Clients / peers awaiting responses.
Definition: dns.h:76
ip4_address_t * ip4_name_servers
upstream name servers, e.g.
Definition: dns.h:105
u8 * cname
For CNAME records, the "next name" to resolve.
Definition: dns.h:57
u8 * name
The name in "normal human being" notation, e.g.
Definition: dns.h:54
unsigned short u16
Definition: types.h:57
#define foreach_dns46_reply_error
Definition: dns.h:142
dns46_reply_error_t
Definition: dns.h:149
int server_rotor
Definition: dns.h:67
int vnet_dns_cname_indirection_nolock(dns_main_t *dm, u32 ep_index, u8 *reply)
Handle cname indirection.
Definition: dns.c:937
dns_pending_request_type_t
Definition: dns.h:40
static void dns_cache_unlock(dns_main_t *dm)
Definition: dns.h:196
int vnet_dns_delete_entry_by_index_nolock(dns_main_t *dm, u32 index)
Definition: dns.c:638
static void dns_cache_lock(dns_main_t *dm)
Definition: dns.h:186
uword * cache_lock
Definition: dns.h:99
void vnet_send_dns6_reply(dns_main_t *dm, dns_pending_request_t *t, dns_cache_entry_t *ep, vlib_buffer_t *b0)
Definition: dns.c:2720
volatile u8 flags
flags
Definition: dns.h:51
vnet_main_t * vnet_main
Definition: dns.h:115
uword * cache_entry_by_name
Find cached record by name.
Definition: dns.h:98
vlib_node_registration_t dns_resolver_node
(constructor) VLIB_REGISTER_NODE (dns_resolver_node)
vlib_node_registration_t dns6_request_node
(constructor) VLIB_REGISTER_NODE (dns6_request_node)
Definition: request_node.c:320
struct _vlib_node_registration vlib_node_registration_t
u32 max_ttl_in_seconds
Definition: dns.h:110
u32 name_cache_size
config parameters
Definition: dns.h:109
u64 uword
Definition: types.h:112
format_function_t format_dns_reply
Definition: dns.h:183
Definition: dns.h:89
int server_fails
Definition: dns.h:69
void vnet_send_dns_request(dns_main_t *dm, dns_cache_entry_t *ep)
Definition: dns.c:515
u32 random_seed
Definition: dns.h:111
int server_af
Definition: dns.h:68
#define CLIB_MEMORY_BARRIER()
Definition: clib.h:109
f64 expiration_time
Expiration time.
Definition: dns.h:60
#define foreach_dns46_request_error
Definition: dns.h:125
dns46_request_error_t
Definition: dns.h:134
int is_enabled
enable / disable flag
Definition: dns.h:102
dns_cache_entry_t * entries
Pool of cache entries.
Definition: dns.h:92