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>
42 vnet_dns_response_to_reply (u8 * response,
43 vl_api_dns_resolve_name_reply_t * rmp,
46 vnet_dns_response_to_name (u8 * response,
47 vl_api_dns_resolve_ip_reply_t * rmp,
51 resolve_event (dns_main_t * dm, f64 now, u8 * reply)
53 vlib_main_t *vm = dm->vlib_main;
54 dns_pending_request_t *pr;
57 dns_cache_entry_t *ep;
64 d = (dns_header_t *) reply;
65 flags = clib_net_to_host_u16 (d->flags);
66 rcode = flags & DNS_RCODE_MASK;
68 /* $$$ u16 limits cache to 65K entries, fix later multiple dst ports */
69 pool_index = clib_net_to_host_u16 (d->id);
72 if (pool_is_free_index (dm->entries, pool_index))
75 vlib_node_increment_counter (vm, dns46_reply_node.index,
76 DNS46_REPLY_ERROR_NO_ELT, 1);
77 dns_cache_unlock (dm);
81 ep = pool_elt_at_index (dm->entries, pool_index);
84 vec_free (ep->dns_response);
86 /* Handle [sic] recursion AKA CNAME indirection */
87 rv = vnet_dns_cname_indirection_nolock (dm, pool_index, reply);
89 /* CNAME found, further resolution pending, we're done here */
92 dns_cache_unlock (dm);
95 /* Server backfire: refused to answer, or sent zero replies */
98 /* Try a different server */
99 if (ep->server_af /* ip6 */ )
102 clib_warning ("Server %U failed to resolve '%s'",
104 dm->ip6_name_servers + ep->server_rotor, ep->name);
105 /* Any more servers to try? */
106 if (ep->server_fails > 1 || vec_len (dm->ip6_name_servers) <= 1)
108 /* No, tell the client to go away */
114 if (ep->server_rotor >= vec_len (dm->ip6_name_servers))
115 ep->server_rotor = 0;
117 clib_warning ("Try server %U", format_ip6_address,
118 dm->ip6_name_servers + ep->server_rotor);
119 vnet_dns_send_dns6_request
120 (dm, ep, dm->ip6_name_servers + ep->server_rotor);
125 clib_warning ("Server %U failed to resolve '%s'",
127 dm->ip4_name_servers + ep->server_rotor, ep->name);
129 if (ep->server_fails > 1 || vec_len (dm->ip4_name_servers) <= 1)
131 /* No, tell the client to go away */
137 if (ep->server_rotor >= vec_len (dm->ip4_name_servers))
138 ep->server_rotor = 0;
140 clib_warning ("Try server %U", format_ip4_address,
141 dm->ip4_name_servers + ep->server_rotor);
142 vnet_dns_send_dns4_request
143 (dm, ep, dm->ip4_name_servers + ep->server_rotor);
145 dns_cache_unlock (dm);
150 /* Save the response */
151 ep->dns_response = reply;
152 /* Pick some sensible default. */
153 ep->expiration_time = now + 600.0;
154 if (vec_len (ep->dns_response))
155 ep->flags |= DNS_CACHE_ENTRY_FLAG_VALID;
157 /* Most likely, send 1 message */
158 for (i = 0; i < vec_len (ep->pending_requests); i++)
160 vl_api_registration_t *regp;
162 pr = vec_elt_at_index (ep->pending_requests, i);
164 switch (pr->request_type)
166 case DNS_API_PENDING_NAME_TO_IP:
168 vl_api_dns_resolve_name_reply_t *rmp;
169 regp = vl_api_client_index_to_registration (pr->client_index);
173 rmp = vl_msg_api_alloc (sizeof (*rmp));
175 clib_host_to_net_u16 (VL_API_DNS_RESOLVE_NAME_REPLY);
176 rmp->context = pr->client_context;
178 rv = vnet_dns_response_to_reply (ep->dns_response, rmp, &min_ttl);
180 ep->expiration_time = now + min_ttl;
181 rmp->retval = clib_host_to_net_u32 (rv);
182 vl_api_send_msg (regp, (u8 *) rmp);
186 case DNS_API_PENDING_IP_TO_NAME:
188 vl_api_dns_resolve_ip_reply_t *rmp;
190 regp = vl_api_client_index_to_registration (pr->client_index);
194 rmp = vl_msg_api_alloc (sizeof (*rmp));
196 clib_host_to_net_u16 (VL_API_DNS_RESOLVE_IP_REPLY);
197 rmp->context = pr->client_context;
199 rv = vnet_dns_response_to_name (ep->dns_response, rmp, &min_ttl);
201 ep->expiration_time = now + min_ttl;
202 rmp->retval = clib_host_to_net_u32 (rv);
203 vl_api_send_msg (regp, (u8 *) rmp);
207 case DNS_PEER_PENDING_IP_TO_NAME:
208 case DNS_PEER_PENDING_NAME_TO_IP:
210 vnet_send_dns6_reply (dm, pr, ep, 0 /* allocate a buffer */ );
212 vnet_send_dns4_reply (dm, pr, ep, 0 /* allocate a buffer */ );
215 clib_warning ("request type %d unknown", pr->request_type);
219 vec_free (ep->pending_requests);
221 for (i = 0; i < vec_len (dm->unresolved_entries); i++)
223 if (dm->unresolved_entries[i] == pool_index)
225 vec_delete (dm->unresolved_entries, 1, i);
229 clib_warning ("pool index %d AWOL from unresolved vector", pool_index);
232 /* Deal with bogus names, server issues, etc. */
236 case DNS_RCODE_NO_ERROR:
239 case DNS_RCODE_SERVER_FAILURE:
240 case DNS_RCODE_NOT_IMPLEMENTED:
241 case DNS_RCODE_REFUSED:
242 if (ep->server_af == 0)
243 clib_warning ("name server %U backfire",
245 dm->ip4_name_servers + ep->server_rotor);
247 clib_warning ("name server %U backfire",
249 dm->ip6_name_servers + ep->server_rotor);
251 case DNS_RCODE_NAME_ERROR:
252 case DNS_RCODE_FORMAT_ERROR:
253 /* remove trash from the cache... */
254 vnet_dns_delete_entry_by_index_nolock (dm, ep - dm->entries);
258 dns_cache_unlock (dm);
263 retry_scan (dns_main_t * dm, f64 now)
266 dns_cache_entry_t *ep;
268 for (i = 0; i < vec_len (dm->unresolved_entries); i++)
271 ep = pool_elt_at_index (dm->entries, dm->unresolved_entries[i]);
273 ASSERT ((ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) == 0);
274 vnet_send_dns_request (dm, ep);
275 dns_cache_unlock (dm);
280 dns_resolver_process (vlib_main_t * vm,
281 vlib_node_runtime_t * rt, vlib_frame_t * f)
283 dns_main_t *dm = &dns_main;
285 f64 timeout = 1000.0;
286 uword *event_data = 0;
292 vlib_process_wait_for_event_or_clock (vm, timeout);
294 now = vlib_time_now (vm);
296 event_type = vlib_process_get_events (vm, (uword **) & event_data);
300 /* Send one of these when a resolution is pending */
301 case DNS_RESOLVER_EVENT_PENDING:
305 case DNS_RESOLVER_EVENT_RESOLVED:
306 for (i = 0; i < vec_len (event_data); i++)
307 resolve_event (dm, now, (u8 *) event_data[i]);
310 case ~0: /* timeout */
311 retry_scan (dm, now);
314 vec_reset_length (event_data);
316 /* No work? Back to slow timeout mode... */
317 if (vec_len (dm->unresolved_entries) == 0)
320 return 0; /* or not */
324 vnet_dns_create_resolver_process (dns_main_t * dm)
326 /* Already created the resolver process? */
327 if (dm->resolver_process_node_index > 0)
330 /* No, create it now and make a note of the node index */
331 dm->resolver_process_node_index = vlib_process_create
332 (dm->vlib_main, "dns-resolver-process",
333 dns_resolver_process, 16 /* log2_n_stack_bytes */ );
337 * fd.io coding-style-patch-verification: ON
340 * eval: (c-set-style "gnu")