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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
16 #include <vnet/dns/dns.h>
17 #include <vlibapi/api.h>
18 #include <vlibmemory/api.h>
20 #include <vlib/vlib.h>
21 #include <vnet/vnet.h>
23 #include <vnet/vnet_msg_enum.h>
25 #define vl_typedefs /* define message structures */
26 #include <vnet/vnet_all_api_h.h>
29 #define vl_endianfun /* define message structures */
30 #include <vnet/vnet_all_api_h.h>
33 /* instantiate all the print functions we know about */
34 #define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
36 #include <vnet/vnet_all_api_h.h>
39 #include <vlibapi/api_helper_macros.h>
41 vlib_node_registration_t dns_resolver_node;
44 vnet_dns_response_to_reply (u8 * response,
45 vl_api_dns_resolve_name_reply_t * rmp,
48 vnet_dns_response_to_name (u8 * response,
49 vl_api_dns_resolve_ip_reply_t * rmp,
53 resolve_event (dns_main_t * dm, f64 now, u8 * reply)
55 vlib_main_t *vm = dm->vlib_main;
56 dns_pending_request_t *pr;
59 dns_cache_entry_t *ep;
66 d = (dns_header_t *) reply;
67 flags = clib_net_to_host_u16 (d->flags);
68 rcode = flags & DNS_RCODE_MASK;
70 /* $$$ u16 limits cache to 65K entries, fix later multiple dst ports */
71 pool_index = clib_net_to_host_u16 (d->id);
74 if (pool_is_free_index (dm->entries, pool_index))
77 vlib_node_increment_counter (vm, dns46_reply_node.index,
78 DNS46_REPLY_ERROR_NO_ELT, 1);
79 dns_cache_unlock (dm);
83 ep = pool_elt_at_index (dm->entries, pool_index);
86 vec_free (ep->dns_response);
88 /* Handle [sic] recursion AKA CNAME indirection */
89 rv = vnet_dns_cname_indirection_nolock (dm, pool_index, reply);
91 /* CNAME found, further resolution pending, we're done here */
94 dns_cache_unlock (dm);
97 /* Server backfire: refused to answer, or sent zero replies */
100 /* Try a different server */
101 if (ep->server_af /* ip6 */ )
104 clib_warning ("Server %U failed to resolve '%s'",
106 dm->ip6_name_servers + ep->server_rotor, ep->name);
107 /* Any more servers to try? */
108 if (ep->server_fails > 1 || vec_len (dm->ip6_name_servers) <= 1)
110 /* No, tell the client to go away */
116 if (ep->server_rotor >= vec_len (dm->ip6_name_servers))
117 ep->server_rotor = 0;
119 clib_warning ("Try server %U", format_ip6_address,
120 dm->ip6_name_servers + ep->server_rotor);
121 vnet_dns_send_dns6_request
122 (dm, ep, dm->ip6_name_servers + ep->server_rotor);
127 clib_warning ("Server %U failed to resolve '%s'",
129 dm->ip4_name_servers + ep->server_rotor, ep->name);
131 if (ep->server_fails > 1 || vec_len (dm->ip4_name_servers) <= 1)
133 /* No, tell the client to go away */
139 if (ep->server_rotor >= vec_len (dm->ip4_name_servers))
140 ep->server_rotor = 0;
142 clib_warning ("Try server %U", format_ip4_address,
143 dm->ip4_name_servers + ep->server_rotor);
144 vnet_dns_send_dns4_request
145 (dm, ep, dm->ip4_name_servers + ep->server_rotor);
147 dns_cache_unlock (dm);
152 /* Save the response */
153 ep->dns_response = reply;
154 /* Pick some sensible default. */
155 ep->expiration_time = now + 600.0;
156 if (vec_len (ep->dns_response))
157 ep->flags |= DNS_CACHE_ENTRY_FLAG_VALID;
159 /* Most likely, send 1 message */
160 for (i = 0; i < vec_len (ep->pending_requests); i++)
162 vl_api_registration_t *regp;
164 pr = vec_elt_at_index (ep->pending_requests, i);
166 switch (pr->request_type)
168 case DNS_API_PENDING_NAME_TO_IP:
170 vl_api_dns_resolve_name_reply_t *rmp;
171 regp = vl_api_client_index_to_registration (pr->client_index);
175 rmp = vl_msg_api_alloc (sizeof (*rmp));
177 clib_host_to_net_u16 (VL_API_DNS_RESOLVE_NAME_REPLY);
178 rmp->context = pr->client_context;
180 rv = vnet_dns_response_to_reply (ep->dns_response, rmp, &min_ttl);
182 ep->expiration_time = now + min_ttl;
183 rmp->retval = clib_host_to_net_u32 (rv);
184 vl_api_send_msg (regp, (u8 *) rmp);
188 case DNS_API_PENDING_IP_TO_NAME:
190 vl_api_dns_resolve_ip_reply_t *rmp;
192 regp = vl_api_client_index_to_registration (pr->client_index);
196 rmp = vl_msg_api_alloc (sizeof (*rmp));
198 clib_host_to_net_u16 (VL_API_DNS_RESOLVE_IP_REPLY);
199 rmp->context = pr->client_context;
201 rv = vnet_dns_response_to_name (ep->dns_response, rmp, &min_ttl);
203 ep->expiration_time = now + min_ttl;
204 rmp->retval = clib_host_to_net_u32 (rv);
205 vl_api_send_msg (regp, (u8 *) rmp);
209 case DNS_PEER_PENDING_IP_TO_NAME:
210 case DNS_PEER_PENDING_NAME_TO_IP:
212 vnet_send_dns6_reply (dm, pr, ep, 0 /* allocate a buffer */ );
214 vnet_send_dns4_reply (dm, pr, ep, 0 /* allocate a buffer */ );
217 clib_warning ("request type %d unknown", pr->request_type);
221 vec_free (ep->pending_requests);
223 for (i = 0; i < vec_len (dm->unresolved_entries); i++)
225 if (dm->unresolved_entries[i] == pool_index)
227 vec_delete (dm->unresolved_entries, 1, i);
231 clib_warning ("pool index %d AWOL from unresolved vector", pool_index);
234 /* Deal with bogus names, server issues, etc. */
238 case DNS_RCODE_NO_ERROR:
241 case DNS_RCODE_SERVER_FAILURE:
242 case DNS_RCODE_NOT_IMPLEMENTED:
243 case DNS_RCODE_REFUSED:
244 if (ep->server_af == 0)
245 clib_warning ("name server %U backfire",
247 dm->ip4_name_servers + ep->server_rotor);
249 clib_warning ("name server %U backfire",
251 dm->ip6_name_servers + ep->server_rotor);
253 case DNS_RCODE_NAME_ERROR:
254 case DNS_RCODE_FORMAT_ERROR:
255 /* remove trash from the cache... */
256 vnet_dns_delete_entry_by_index_nolock (dm, ep - dm->entries);
260 dns_cache_unlock (dm);
265 retry_scan (dns_main_t * dm, f64 now)
268 dns_cache_entry_t *ep;
270 for (i = 0; i < vec_len (dm->unresolved_entries); i++)
273 ep = pool_elt_at_index (dm->entries, dm->unresolved_entries[i]);
275 ASSERT ((ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) == 0);
276 vnet_send_dns_request (dm, ep);
277 dns_cache_unlock (dm);
282 dns_resolver_process (vlib_main_t * vm,
283 vlib_node_runtime_t * rt, vlib_frame_t * f)
285 dns_main_t *dm = &dns_main;
287 f64 timeout = 1000.0;
288 uword *event_data = 0;
294 vlib_process_wait_for_event_or_clock (vm, timeout);
296 now = vlib_time_now (vm);
298 event_type = vlib_process_get_events (vm, (uword **) & event_data);
302 /* Send one of these when a resolution is pending */
303 case DNS_RESOLVER_EVENT_PENDING:
307 case DNS_RESOLVER_EVENT_RESOLVED:
308 for (i = 0; i < vec_len (event_data); i++)
309 resolve_event (dm, now, (u8 *) event_data[i]);
312 case ~0: /* timeout */
313 retry_scan (dm, now);
316 vec_reset_length (event_data);
318 /* No work? Back to slow timeout mode... */
319 if (vec_len (dm->unresolved_entries) == 0)
322 return 0; /* or not */
326 VLIB_REGISTER_NODE (dns_resolver_node) =
328 .function = dns_resolver_process,
329 .type = VLIB_NODE_TYPE_PROCESS,
330 .name = "dns-resolver-process",
336 * fd.io coding-style-patch-verification: ON
339 * eval: (c-set-style "gnu")