dns: make the dns name resolver a plugin

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

1 files changed, 226 insertions, 0 deletions

diff --git a/src/plugins/dns/dns.h b/src/plugins/dns/dns.h
new file mode 100644
index 00000000000..0a3f7a935cb
--- /dev/null
+++ b/src/plugins/dns/dns.h
@@ -0,0 +1,226 @@
+/*
+ * 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.
+ */
+
+#ifndef included_dns_h
+#define included_dns_h
+
+#include <vppinfra/time.h>
+#include <vppinfra/cache.h>
+#include <vppinfra/error.h>
+
+#include <vppinfra/hash.h>
+#include <dns/dns_packet.h>
+#include <vnet/ip/ip.h>
+#include <vppinfra/lock.h>
+#include <vlibapi/api_common.h>
+
+typedef struct
+{
+  u32 request_type;
+  u32 client_index;
+  u32 client_context;
+  u8 is_ip6;
+  u16 dst_port;
+  u16 id;
+  u16 pad;
+  u8 dst_address[16];
+  u8 *name;
+} dns_pending_request_t;
+
+typedef enum
+{
+  DNS_API_PENDING_NAME_TO_IP = 1,
+  DNS_API_PENDING_IP_TO_NAME,
+  DNS_PEER_PENDING_NAME_TO_IP,
+  DNS_PEER_PENDING_IP_TO_NAME,
+} dns_pending_request_type_t;
+
+typedef struct
+{
+  /** flags */
+  volatile u8 flags;
+
+  /** The name in "normal human being" notation, e.g. www.foobar.com */
+  u8 *name;
+
+  /** For CNAME records, the "next name" to resolve */
+  u8 *cname;
+
+  /** Expiration time */
+  f64 expiration_time;
+
+  /** Cached dns request, for sending retries */
+  u8 *dns_request;
+
+  /** Retry parameters */
+  int retry_count;
+  int server_rotor;
+  int server_af;
+  int server_fails;
+  f64 retry_timer;
+
+  /** Cached dns response */
+  u8 *dns_response;
+
+  /** Clients / peers awaiting responses */
+  dns_pending_request_t *pending_requests;
+} dns_cache_entry_t;
+
+#define DNS_CACHE_ENTRY_FLAG_VALID	(1<<0) /**< we have Actual Data */
+#define DNS_CACHE_ENTRY_FLAG_STATIC	(1<<1) /**< static entry */
+#define DNS_CACHE_ENTRY_FLAG_CNAME	(1<<2) /**< CNAME (indirect) entry */
+
+#define DNS_RETRIES_PER_SERVER 3
+
+#define DNS_RESOLVER_EVENT_RESOLVED	1
+#define DNS_RESOLVER_EVENT_PENDING	2
+
+
+typedef struct
+{
+  /** Pool of cache entries */
+  dns_cache_entry_t *entries;
+
+  /** Pool indices of unresolved entries */
+  u32 *unresolved_entries;
+
+  /** Find cached record by name */
+  uword *cache_entry_by_name;
+  clib_spinlock_t cache_lock;
+
+  /** enable / disable flag */
+  int is_enabled;
+
+  /** udp port registration complete */
+  int udp_ports_registered;
+
+  /** upstream name servers, e.g. 8.8.8.8 */
+  ip4_address_t *ip4_name_servers;
+  ip6_address_t *ip6_name_servers;
+
+  /** resolver process node index */
+  u32 resolver_process_node_index;
+
+  /** config parameters */
+  u32 name_cache_size;
+  u32 max_ttl_in_seconds;
+  u32 random_seed;
+
+  /** message-ID base */
+  u16 msg_id_base;
+
+  /* convenience */
+  vlib_main_t *vlib_main;
+  vnet_main_t *vnet_main;
+  api_main_t *api_main;
+} dns_main_t;
+
+extern dns_main_t dns_main;
+
+extern vlib_node_registration_t dns46_reply_node;
+extern vlib_node_registration_t dns4_request_node;
+extern vlib_node_registration_t dns6_request_node;
+
+#define foreach_dns46_request_error                                     \
+_(NONE, "No error")							\
+_(UNIMPLEMENTED, "Unimplemented")                                       \
+_(PROCESSED, "DNS request pkts processed")                              \
+_(IP_OPTIONS, "DNS pkts with ip options (dropped)")                     \
+_(BAD_REQUEST, "DNS pkts with serious discrepanices (dropped)")         \
+_(TOO_MANY_REQUESTS, "DNS pkts asking too many questions")              \
+_(RESOLUTION_REQUIRED, "DNS pkts pending upstream name resolution")
+
+typedef enum
+{
+#define _(sym,str) DNS46_REQUEST_ERROR_##sym,
+  foreach_dns46_request_error
+#undef _
+    DNS46_REQUEST_N_ERROR,
+} dns46_request_error_t;
+
+#define foreach_dns46_reply_error                       \
+_(DISABLED, "DNS pkts punted (feature disabled)")       \
+_(PROCESSED, "DNS reply pkts processed")                \
+_(NO_ELT, "No DNS pool element")                        \
+_(FORMAT_ERROR, "DNS format errors")                    \
+_(TEST_DROP, "DNS reply pkt dropped for test purposes") \
+_(MULTIPLE_REPLY, "DNS multiple reply packets")	        \
+_(NO_UNRESOLVED_ENTRY, "No unresolved entry for pkt")
+
+typedef enum
+{
+#define _(sym,str) DNS46_REPLY_ERROR_##sym,
+  foreach_dns46_reply_error
+#undef _
+    DNS46_REPLY_N_ERROR,
+} dns46_reply_error_t;
+
+void vnet_send_dns_request (dns_main_t * dm, dns_cache_entry_t * ep);
+int
+vnet_dns_cname_indirection_nolock (dns_main_t * dm, u32 ep_index, u8 * reply);
+
+int vnet_dns_delete_entry_by_index_nolock (dns_main_t * dm, u32 index);
+
+int
+vnet_dns_resolve_name (dns_main_t * dm, u8 * name, dns_pending_request_t * t,
+		       dns_cache_entry_t ** retp);
+
+void
+vnet_dns_send_dns6_request (dns_main_t * dm,
+			    dns_cache_entry_t * ep, ip6_address_t * server);
+void
+vnet_dns_send_dns4_request (dns_main_t * dm,
+			    dns_cache_entry_t * ep, ip4_address_t * server);
+
+void vnet_send_dns4_reply (dns_main_t * dm, dns_pending_request_t * t,
+			   dns_cache_entry_t * ep, vlib_buffer_t * b0);
+
+void vnet_send_dns6_reply (dns_main_t * dm, dns_pending_request_t * t,
+			   dns_cache_entry_t * ep, vlib_buffer_t * b0);
+
+u8 *vnet_dns_labels_to_name (u8 * label, u8 * full_text,
+			     u8 ** parse_from_here);
+
+void vnet_dns_create_resolver_process (dns_main_t * dm);
+
+format_function_t format_dns_reply;
+
+static inline void
+dns_cache_lock (dns_main_t * dm)
+{
+  if (dm->cache_lock)
+    {
+      clib_spinlock_lock (&dm->cache_lock);
+    }
+}
+
+static inline void
+dns_cache_unlock (dns_main_t * dm)
+{
+  if (dm->cache_lock)
+    {
+      clib_spinlock_unlock (&dm->cache_lock);
+    }
+}
+
+#endif /* included_dns_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */