diff options
Diffstat (limited to 'src/vnet/dns/resolver_process.c')
| -rw-r--r-- | src/vnet/dns/resolver_process.c | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/src/vnet/dns/resolver_process.c b/src/vnet/dns/resolver_process.c new file mode 100644 index 00000000000..91e5cef1bcd --- /dev/null +++ b/src/vnet/dns/resolver_process.c @@ -0,0 +1,243 @@ +/* + * 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> + +vlib_node_registration_t dns_resolver_node; + +extern int +vnet_dns_response_to_reply (u8 * response, + vl_api_dns_resolve_name_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_header_t *d; + u32 pool_index; + dns_cache_entry_t *ep; + u32 min_ttl; + u16 flags; + u16 rcode; + int i; + int rv = 0; + + d = (dns_header_t *) reply; + flags = clib_net_to_host_u16 (d->flags); + rcode = flags & DNS_RCODE_MASK; + + /* $$$ u16 limits cache to 65K entries, fix later multiple dst ports */ + pool_index = clib_net_to_host_u16 (d->id); + dns_cache_lock (dm); + + if (pool_is_free_index (dm->entries, pool_index)) + { + vec_free (reply); + vlib_node_increment_counter (vm, dns46_reply_node.index, + DNS46_REPLY_ERROR_NO_ELT, 1); + dns_cache_unlock (dm); + return; + } + + ep = pool_elt_at_index (dm->entries, pool_index); + + if (ep->dns_response) + vec_free (ep->dns_response); + + /* Handle [sic] recursion AKA CNAME indirection */ + if (vnet_dns_cname_indirection_nolock (dm, ep, reply)) + { + dns_cache_unlock (dm); + return; + } + + /* Save the response */ + ep->dns_response = reply; + /* Pick some sensible default. */ + ep->expiration_time = now + 600.0; + if (vec_len (ep->dns_response)) + ep->flags |= DNS_CACHE_ENTRY_FLAG_VALID; + + /* Most likely, send 1 message */ + for (i = 0; i < vec_len (ep->api_clients_to_notify); i++) + { + vl_api_registration_t *regp; + vl_api_dns_resolve_name_reply_t *rmp; + + regp = vl_api_client_index_to_registration + (ep->api_clients_to_notify[i]); + + if (regp == 0) + continue; + + rmp = vl_msg_api_alloc (sizeof (*rmp) + vec_len (ep->dns_response)); + rmp->_vl_msg_id = clib_host_to_net_u16 (VL_API_DNS_RESOLVE_NAME_REPLY); + rmp->context = ep->api_client_contexts[i]; + min_ttl = ~0; + rv = vnet_dns_response_to_reply (ep->dns_response, rmp, &min_ttl); + if (min_ttl != ~0) + ep->expiration_time = now + min_ttl; + rmp->retval = clib_host_to_net_u32 (rv); + vl_msg_api_send (regp, (u8 *) rmp); + } + vec_free (ep->api_clients_to_notify); + vec_free (ep->api_client_contexts); + + /* $$$ Add ip4/ip6 reply code */ + + for (i = 0; i < vec_len (dm->unresolved_entries); i++) + { + if (dm->unresolved_entries[i] == pool_index) + { + vec_delete (dm->unresolved_entries, 1, i); + goto found; + } + } + clib_warning ("pool index %d AWOL from unresolved vector", pool_index); + +found: + /* 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 backfire", + format_ip4_address, + dm->ip4_name_servers + ep->server_rotor); + else + clib_warning ("name server %U backfire", + format_ip6_address, + dm->ip6_name_servers + ep->server_rotor); + /* 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 */ +} + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (dns_resolver_node) = +{ + .function = dns_resolver_process, + .type = VLIB_NODE_TYPE_PROCESS, + .name = "dns-resolver-process", +}; +/* *INDENT-ON* */ + + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |