dns: make the dns name resolver a plugin

Type: refactor
Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I823c2cd307a4613653a2d20f564dda062d4da31b

1 files changed, 0 insertions, 378 deletions

diff --git a/src/vnet/dns/resolver_process.c b/src/vnet/dns/resolver_process.c
deleted file mode 100644
index 4ed7c799ce2..00000000000
--- a/src/vnet/dns/resolver_process.c
+++ /dev/null
@@ -1,378 +0,0 @@
-/*
- * 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:
- */