+++ /dev/null
-/*
- * 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.
- */
-
-#include <vnet/dns/dns.h>
-#include <vlibapi/api.h>
-#include <vlibmemory/api.h>
-
-#include <vlib/vlib.h>
-#include <vnet/vnet.h>
-
-#include <vnet/vnet_msg_enum.h>
-
-#define vl_typedefs /* define message structures */
-#include <vnet/vnet_all_api_h.h>
-#undef vl_typedefs
-
-#define vl_endianfun /* define message structures */
-#include <vnet/vnet_all_api_h.h>
-#undef vl_endianfun
-
-/* instantiate all the print functions we know about */
-#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
-#define vl_printfun
-#include <vnet/vnet_all_api_h.h>
-#undef vl_printfun
-
-#include <vlibapi/api_helper_macros.h>
-
-extern int
-vnet_dns_response_to_reply (u8 * response,
- vl_api_dns_resolve_name_reply_t * rmp,
- u32 * min_ttlp);
-extern int
-vnet_dns_response_to_name (u8 * response,
- vl_api_dns_resolve_ip_reply_t * rmp,
- u32 * min_ttlp);
-
-static void
-resolve_event (dns_main_t * dm, f64 now, u8 * reply)
-{
- vlib_main_t *vm = dm->vlib_main;
- dns_pending_request_t *pr;
- dns_header_t *d;
- u32 pool_index;
- dns_cache_entry_t *ep;
- u32 min_ttl;
- u16 flags;
- u16 rcode;
- int i;
- int entry_was_valid;
- int remove_count;
- int rv = 0;
-
- d = (dns_header_t *) reply;
- flags = clib_net_to_host_u16 (d->flags);
- rcode = flags & DNS_RCODE_MASK;
-
- /* $$$ u16 limits cache to 65K entries, fix later multiple dst ports */
- pool_index = clib_net_to_host_u16 (d->id);
- dns_cache_lock (dm);
-
- if (pool_is_free_index (dm->entries, pool_index))
- {
- vec_free (reply);
- if (0)
- clib_warning ("pool index %d is free", pool_index);
- vlib_node_increment_counter (vm, dns46_reply_node.index,
- DNS46_REPLY_ERROR_NO_ELT, 1);
- dns_cache_unlock (dm);
- return;
- }
-
- ep = pool_elt_at_index (dm->entries, pool_index);
-
- if (ep->dns_response)
- vec_free (ep->dns_response);
-
- /* Handle [sic] recursion AKA CNAME indirection */
- rv = vnet_dns_cname_indirection_nolock (dm, pool_index, reply);
-
- /* CNAME found, further resolution pending, we're done here */
- if (rv > 0)
- {
- dns_cache_unlock (dm);
- return;
- }
- /* Server backfire: refused to answer, or sent zero replies */
- if (rv < 0)
- {
- /* Try a different server */
- if (ep->server_af /* ip6 */ )
- {
- if (0)
- clib_warning ("Server %U failed to resolve '%s'",
- format_ip6_address,
- dm->ip6_name_servers + ep->server_rotor, ep->name);
- /* Any more servers to try? */
- if (ep->server_fails > 1 || vec_len (dm->ip6_name_servers) <= 1)
- {
- /* No, tell the client to go away */
- goto reply;
- }
- ep->retry_count = 0;
- ep->server_rotor++;
- ep->server_fails++;
- if (ep->server_rotor >= vec_len (dm->ip6_name_servers))
- ep->server_rotor = 0;
- if (0)
- clib_warning ("Try server %U", format_ip6_address,
- dm->ip6_name_servers + ep->server_rotor);
- vnet_dns_send_dns6_request
- (dm, ep, dm->ip6_name_servers + ep->server_rotor);
- }
- else
- {
- if (0)
- clib_warning ("Server %U failed to resolve '%s'",
- format_ip4_address,
- dm->ip4_name_servers + ep->server_rotor, ep->name);
-
- if (ep->server_fails > 1 || vec_len (dm->ip4_name_servers) <= 1)
- {
- /* No, tell the client to go away */
- goto reply;
- }
- ep->retry_count = 0;
- ep->server_rotor++;
- ep->server_fails++;
- if (ep->server_rotor >= vec_len (dm->ip4_name_servers))
- ep->server_rotor = 0;
- if (0)
- clib_warning ("Try server %U", format_ip4_address,
- dm->ip4_name_servers + ep->server_rotor);
- vnet_dns_send_dns4_request
- (dm, ep, dm->ip4_name_servers + ep->server_rotor);
- }
- dns_cache_unlock (dm);
- return;
- }
-
-reply:
- /* Save the response */
- ep->dns_response = reply;
-
- /*
- * Pick a sensible default cache entry expiration time.
- * We don't play the 10-second timeout game.
- */
- ep->expiration_time = now + 600.0;
-
- if (0)
- clib_warning ("resolving '%s', was %s valid",
- ep->name, (ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) ?
- "already" : "not");
- /*
- * The world is a mess. A single DNS request sent to e.g. 8.8.8.8
- * may yield multiple, subtly different responses - all with the same
- * DNS protocol-level ID.
- *
- * Last response wins in terms of what ends up in the cache.
- * First response wins in terms of the response sent to the client.
- */
-
- /* Strong hint that we may not find a pending resolution entry */
- entry_was_valid = (ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) ? 1 : 0;
-
- if (vec_len (ep->dns_response))
- ep->flags |= DNS_CACHE_ENTRY_FLAG_VALID;
-
- /* Most likely, send 1 message */
- for (i = 0; i < vec_len (ep->pending_requests); i++)
- {
- vl_api_registration_t *regp;
-
- pr = vec_elt_at_index (ep->pending_requests, i);
-
- switch (pr->request_type)
- {
- case DNS_API_PENDING_NAME_TO_IP:
- {
- vl_api_dns_resolve_name_reply_t *rmp;
- regp = vl_api_client_index_to_registration (pr->client_index);
- if (regp == 0)
- continue;
-
- rmp = vl_msg_api_alloc (sizeof (*rmp));
- rmp->_vl_msg_id =
- clib_host_to_net_u16 (VL_API_DNS_RESOLVE_NAME_REPLY);
- rmp->context = pr->client_context;
- min_ttl = ~0;
- rv = vnet_dns_response_to_reply (ep->dns_response, rmp, &min_ttl);
- if (min_ttl != ~0)
- ep->expiration_time = now + min_ttl;
- rmp->retval = clib_host_to_net_u32 (rv);
- vl_api_send_msg (regp, (u8 *) rmp);
- }
- break;
-
- case DNS_API_PENDING_IP_TO_NAME:
- {
- vl_api_dns_resolve_ip_reply_t *rmp;
-
- regp = vl_api_client_index_to_registration (pr->client_index);
- if (regp == 0)
- continue;
-
- rmp = vl_msg_api_alloc (sizeof (*rmp));
- rmp->_vl_msg_id =
- clib_host_to_net_u16 (VL_API_DNS_RESOLVE_IP_REPLY);
- rmp->context = pr->client_context;
- min_ttl = ~0;
- rv = vnet_dns_response_to_name (ep->dns_response, rmp, &min_ttl);
- if (min_ttl != ~0)
- ep->expiration_time = now + min_ttl;
- rmp->retval = clib_host_to_net_u32 (rv);
- vl_api_send_msg (regp, (u8 *) rmp);
- }
- break;
-
- case DNS_PEER_PENDING_IP_TO_NAME:
- case DNS_PEER_PENDING_NAME_TO_IP:
- if (pr->is_ip6)
- vnet_send_dns6_reply (dm, pr, ep, 0 /* allocate a buffer */ );
- else
- vnet_send_dns4_reply (dm, pr, ep, 0 /* allocate a buffer */ );
- break;
- default:
- clib_warning ("request type %d unknown", pr->request_type);
- break;
- }
- }
- vec_free (ep->pending_requests);
-
- remove_count = 0;
- for (i = 0; i < vec_len (dm->unresolved_entries); i++)
- {
- if (dm->unresolved_entries[i] == pool_index)
- {
- vec_delete (dm->unresolved_entries, 1, i);
- remove_count++;
- i--;
- }
- }
- /* See multiple response comment above... */
- if (remove_count == 0)
- {
- u32 error_code = entry_was_valid ? DNS46_REPLY_ERROR_MULTIPLE_REPLY :
- DNS46_REPLY_ERROR_NO_UNRESOLVED_ENTRY;
-
- vlib_node_increment_counter (vm, dns46_reply_node.index, error_code, 1);
- dns_cache_unlock (dm);
- return;
- }
-
- /* Deal with bogus names, server issues, etc. */
- switch (rcode)
- {
- default:
- case DNS_RCODE_NO_ERROR:
- break;
-
- case DNS_RCODE_SERVER_FAILURE:
- case DNS_RCODE_NOT_IMPLEMENTED:
- case DNS_RCODE_REFUSED:
- if (ep->server_af == 0)
- clib_warning ("name server %U can't resolve '%s'",
- format_ip4_address,
- dm->ip4_name_servers + ep->server_rotor, ep->name);
- else
- clib_warning ("name server %U can't resolve '%s'",
- format_ip6_address,
- dm->ip6_name_servers + ep->server_rotor, ep->name);
- /* FALLTHROUGH */
- case DNS_RCODE_NAME_ERROR:
- case DNS_RCODE_FORMAT_ERROR:
- /* remove trash from the cache... */
- vnet_dns_delete_entry_by_index_nolock (dm, ep - dm->entries);
- break;
- }
-
-
- dns_cache_unlock (dm);
- return;
-}
-
-static void
-retry_scan (dns_main_t * dm, f64 now)
-{
- int i;
- dns_cache_entry_t *ep;
-
- for (i = 0; i < vec_len (dm->unresolved_entries); i++)
- {
- dns_cache_lock (dm);
- ep = pool_elt_at_index (dm->entries, dm->unresolved_entries[i]);
-
- ASSERT ((ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) == 0);
- vnet_send_dns_request (dm, ep);
- dns_cache_unlock (dm);
- }
-}
-
-static uword
-dns_resolver_process (vlib_main_t * vm,
- vlib_node_runtime_t * rt, vlib_frame_t * f)
-{
- dns_main_t *dm = &dns_main;
- f64 now;
- f64 timeout = 1000.0;
- uword *event_data = 0;
- uword event_type;
- int i;
-
- while (1)
- {
- vlib_process_wait_for_event_or_clock (vm, timeout);
-
- now = vlib_time_now (vm);
-
- event_type = vlib_process_get_events (vm, (uword **) & event_data);
-
- switch (event_type)
- {
- /* Send one of these when a resolution is pending */
- case DNS_RESOLVER_EVENT_PENDING:
- timeout = 2.0;
- break;
-
- case DNS_RESOLVER_EVENT_RESOLVED:
- for (i = 0; i < vec_len (event_data); i++)
- resolve_event (dm, now, (u8 *) event_data[i]);
- break;
-
- case ~0: /* timeout */
- retry_scan (dm, now);
- break;
- }
- vec_reset_length (event_data);
-
- /* No work? Back to slow timeout mode... */
- if (vec_len (dm->unresolved_entries) == 0)
- timeout = 1000.0;
- }
- return 0; /* or not */
-}
-
-void
-vnet_dns_create_resolver_process (dns_main_t * dm)
-{
- /* Already created the resolver process? */
- if (dm->resolver_process_node_index > 0)
- return;
-
- /* No, create it now and make a note of the node index */
- dm->resolver_process_node_index = vlib_process_create
- (dm->vlib_main, "dns-resolver-process",
- dns_resolver_process, 16 /* log2_n_stack_bytes */ );
-}
-
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */
Code Review / vpp.git / blobdiff