FD.io VPP  v18.01.2-1-g9b554f3
Vector Packet Processing
dns.h
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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;
70 
71  /** Cached dns response */
73 
74  /** Clients / peers awaiting responses */
77 
78 #define DNS_CACHE_ENTRY_FLAG_VALID (1<<0) /**< we have Actual Data */
79 #define DNS_CACHE_ENTRY_FLAG_STATIC (1<<1) /**< static entry */
80 #define DNS_CACHE_ENTRY_FLAG_CNAME (1<<2) /**< CNAME (indirect) entry */
81 
82 #define DNS_RETRIES_PER_SERVER 3
83 
84 #define DNS_RESOLVER_EVENT_RESOLVED 1
85 #define DNS_RESOLVER_EVENT_PENDING 2
86 
87 
88 typedef struct
89 {
90  /** Pool of cache entries */
92 
93  /** Pool indices of unresolved entries */
95 
96  /** Find cached record by name */
99 
100  /** enable / disable flag */
102 
103  /** upstream name servers, e.g. 8.8.8.8 */
106 
107  /** config parameters */
111 
112  /* convenience */
115 } dns_main_t;
116 
117 extern dns_main_t dns_main;
118 
123 
124 #define foreach_dns46_request_error \
125 _(NONE, "No error") \
126 _(UNIMPLEMENTED, "Unimplemented") \
127 _(PROCESSED, "DNS request pkts processed") \
128 _(IP_OPTIONS, "DNS pkts with ip options (dropped)") \
129 _(BAD_REQUEST, "DNS pkts with serious discrepanices (dropped)") \
130 _(TOO_MANY_REQUESTS, "DNS pkts asking too many questions") \
131 _(RESOLUTION_REQUIRED, "DNS pkts pending upstream name resolution")
132 
133 typedef enum
134 {
135 #define _(sym,str) DNS46_REQUEST_ERROR_##sym,
137 #undef _
140 
141 #define foreach_dns46_reply_error \
142 _(DISABLED, "DNS pkts punted (feature disabled)") \
143 _(PROCESSED, "DNS reply pkts processed") \
144 _(NO_ELT, "No DNS pool element") \
145 _(FORMAT_ERROR, "DNS format errors") \
146 _(TEST_DROP, "DNS reply pkt dropped for test purposes")
147 
148 typedef enum
149 {
150 #define _(sym,str) DNS46_REPLY_ERROR_##sym,
152 #undef _
155 
157 int
158 vnet_dns_cname_indirection_nolock (dns_main_t * dm, u32 ep_index, u8 * reply);
159 
161 
162 int
164  dns_cache_entry_t ** retp);
165 
167  dns_cache_entry_t * ep, vlib_buffer_t * b0);
168 
170  dns_cache_entry_t * ep, vlib_buffer_t * b0);
171 
172 u8 *vnet_dns_labels_to_name (u8 * label, u8 * full_text,
173  u8 ** parse_from_here);
174 
176 
177 static inline void
179 {
180  if (dm->cache_lock)
181  {
182  while (__sync_lock_test_and_set (dm->cache_lock, 1))
183  ;
184  }
185 }
186 
187 static inline void
189 {
190  if (dm->cache_lock)
191  {
193  *dm->cache_lock = 0;
194  }
195 }
196 
197 #endif /* included_dns_h */
198 
199 /*
200  * fd.io coding-style-patch-verification: ON
201  *
202  * Local Variables:
203  * eval: (c-set-style "gnu")
204  * End:
205  */
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:2652
ip6_address_t * ip6_name_servers
Definition: dns.h:105
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
vlib_node_registration_t dns4_request_node
(constructor) VLIB_REGISTER_NODE (dns4_request_node)
Definition: request_node.c:287
u8 * dns_response
Cached dns response.
Definition: dns.h:72
int retry_count
Retry parameters.
Definition: dns.h:66
struct _vlib_node_registration vlib_node_registration_t
int vnet_dns_resolve_name(dns_main_t *dm, u8 *name, dns_pending_request_t *t, dns_cache_entry_t **retp)
Definition: dns.c:766
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
u32 client_context
Definition: dns.h:31
vlib_main_t * vlib_main
Definition: dns.h:113
u8 * dns_request
Cached dns request, for sending retries.
Definition: dns.h:63
f64 retry_timer
Definition: dns.h:69
u32 * unresolved_entries
Pool indices of unresolved entries.
Definition: dns.h:94
dns_pending_request_t * pending_requests
Clients / peers awaiting responses.
Definition: dns.h:75
ip4_address_t * ip4_name_servers
upstream name servers, e.g.
Definition: dns.h:104
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
#define foreach_dns46_reply_error
Definition: dns.h:141
dns46_reply_error_t
Definition: dns.h:148
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:919
dns_pending_request_type_t
Definition: dns.h:40
static void dns_cache_unlock(dns_main_t *dm)
Definition: dns.h:188
int vnet_dns_delete_entry_by_index_nolock(dns_main_t *dm, u32 index)
Definition: dns.c:620
static void dns_cache_lock(dns_main_t *dm)
Definition: dns.h:178
uword * cache_lock
Definition: dns.h:98
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:2644
volatile u8 flags
flags
Definition: dns.h:51
unsigned int u32
Definition: types.h:88
vnet_main_t * vnet_main
Definition: dns.h:114
uword * cache_entry_by_name
Find cached record by name.
Definition: dns.h:97
u64 uword
Definition: types.h:112
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:314
unsigned short u16
Definition: types.h:57
u32 max_ttl_in_seconds
Definition: dns.h:109
double f64
Definition: types.h:142
unsigned char u8
Definition: types.h:56
u32 name_cache_size
config parameters
Definition: dns.h:108
format_function_t format_dns_reply
Definition: dns.h:175
Definition: dns.h:88
void vnet_send_dns_request(dns_main_t *dm, dns_cache_entry_t *ep)
Definition: dns.c:515
u32 random_seed
Definition: dns.h:110
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:124
dns46_request_error_t
Definition: dns.h:133
int is_enabled
enable / disable flag
Definition: dns.h:101
dns_cache_entry_t * entries
Pool of cache entries.
Definition: dns.h:91