src/plugins/dns/dns.h

   1 /*
   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:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   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.
  14  */
  15
  16 #ifndef included_dns_h
  17 #define included_dns_h
  18
  19 #include <vppinfra/time.h>
  20 #include <vppinfra/cache.h>
  21 #include <vppinfra/error.h>
  22
  23 #include <vppinfra/hash.h>
  24 #include <dns/dns_packet.h>
  25 #include <vnet/ip/ip.h>
  26 #include <vppinfra/lock.h>
  27 #include <vlibapi/api_common.h>
  28
  29 typedef struct
  30 {
  31   u32 request_type;
  32   u32 client_index;
  33   u32 client_context;
  34   u8 is_ip6;
  35   u16 dst_port;
  36   u16 id;
  37   u16 pad;
  38   u8 dst_address[16];
  39   u8 *name;
  40 } dns_pending_request_t;
  41
  42 typedef struct
  43 {
  44   ip_address_t address;
  45 } dns_resolve_name_t;
  46
  47 typedef enum
  48 {
  49   DNS_API_PENDING_NAME_TO_IP = 1,
  50   DNS_API_PENDING_IP_TO_NAME,
  51   DNS_PEER_PENDING_NAME_TO_IP,
  52   DNS_PEER_PENDING_IP_TO_NAME,
  53 } dns_pending_request_type_t;
  54
  55 typedef struct
  56 {
  57   /** flags */
  58   volatile u8 flags;
  59
  60   /** The name in "normal human being" notation, e.g. www.foobar.com */
  61   u8 *name;
  62
  63   /** For CNAME records, the "next name" to resolve */
  64   u8 *cname;
  65
  66   /** Expiration time */
  67   f64 expiration_time;
  68
  69   /** Cached dns request, for sending retries */
  70   u8 *dns_request;
  71
  72   /** Retry parameters */
  73   int retry_count;
  74   int server_rotor;
  75   int server_af;
  76   int server_fails;
  77   f64 retry_timer;
  78
  79   /** Cached dns response */
  80   u8 *dns_response;
  81
  82   /** Clients / peers awaiting responses */
  83   dns_pending_request_t *pending_requests;
  84 } dns_cache_entry_t;
  85
  86 #define DNS_CACHE_ENTRY_FLAG_VALID      (1<<0) /**< we have Actual Data */
  87 #define DNS_CACHE_ENTRY_FLAG_STATIC     (1<<1) /**< static entry */
  88 #define DNS_CACHE_ENTRY_FLAG_CNAME      (1<<2) /**< CNAME (indirect) entry */
  89
  90 #define DNS_RETRIES_PER_SERVER 3
  91
  92 #define DNS_RESOLVER_EVENT_RESOLVED     1
  93 #define DNS_RESOLVER_EVENT_PENDING      2
  94
  95
  96 typedef struct
  97 {
  98   /** Pool of cache entries */
  99   dns_cache_entry_t *entries;
 100
 101   /** Pool indices of unresolved entries */
 102   u32 *unresolved_entries;
 103
 104   /** Find cached record by name */
 105   uword *cache_entry_by_name;
 106   clib_spinlock_t cache_lock;
 107   int cache_lock_tag;
 108
 109   /** enable / disable flag */
 110   int is_enabled;
 111
 112   /** udp port registration complete */
 113   int udp_ports_registered;
 114
 115   /** upstream name servers, e.g. 8.8.8.8 */
 116   ip4_address_t *ip4_name_servers;
 117   ip6_address_t *ip6_name_servers;
 118
 119   /** resolver process node index */
 120   u32 resolver_process_node_index;
 121
 122   /** config parameters */
 123   u32 name_cache_size;
 124   u32 max_ttl_in_seconds;
 125   u32 random_seed;
 126
 127   /** message-ID base */
 128   u16 msg_id_base;
 129
 130   /* convenience */
 131   vnet_main_t *vnet_main;
 132   api_main_t *api_main;
 133 } dns_main_t;
 134
 135 extern dns_main_t dns_main;
 136
 137 extern vlib_node_registration_t dns46_reply_node;
 138 extern vlib_node_registration_t dns4_request_node;
 139 extern vlib_node_registration_t dns6_request_node;
 140
 141 #define foreach_dns46_request_error                                     \
 142 _(NONE, "No error")                                                     \
 143 _(UNIMPLEMENTED, "Unimplemented")                                       \
 144 _(PROCESSED, "DNS request pkts processed")                              \
 145 _(IP_OPTIONS, "DNS pkts with ip options (dropped)")                     \
 146 _(BAD_REQUEST, "DNS pkts with serious discrepancies (dropped)")         \
 147 _(TOO_MANY_REQUESTS, "DNS pkts asking too many questions")              \
 148 _(RESOLUTION_REQUIRED, "DNS pkts pending upstream name resolution")
 149
 150 typedef enum
 151 {
 152 #define _(sym,str) DNS46_REQUEST_ERROR_##sym,
 153   foreach_dns46_request_error
 154 #undef _
 155     DNS46_REQUEST_N_ERROR,
 156 } dns46_request_error_t;
 157
 158 #define foreach_dns46_reply_error                       \
 159 _(DISABLED, "DNS pkts punted (feature disabled)")       \
 160 _(PROCESSED, "DNS reply pkts processed")                \
 161 _(NO_ELT, "No DNS pool element")                        \
 162 _(FORMAT_ERROR, "DNS format errors")                    \
 163 _(TEST_DROP, "DNS reply pkt dropped for test purposes") \
 164 _(MULTIPLE_REPLY, "DNS multiple reply packets")         \
 165 _(NO_UNRESOLVED_ENTRY, "No unresolved entry for pkt")
 166
 167 typedef enum
 168 {
 169 #define _(sym,str) DNS46_REPLY_ERROR_##sym,
 170   foreach_dns46_reply_error
 171 #undef _
 172     DNS46_REPLY_N_ERROR,
 173 } dns46_reply_error_t;
 174
 175 void vnet_send_dns_request (vlib_main_t * vm, dns_main_t * dm,
 176                             dns_cache_entry_t * ep);
 177 int vnet_dns_cname_indirection_nolock (vlib_main_t * vm, dns_main_t * dm,
 178                                        u32 ep_index, u8 * reply);
 179
 180 int vnet_dns_delete_entry_by_index_nolock (dns_main_t * dm, u32 index);
 181
 182 int
 183 vnet_dns_resolve_name (vlib_main_t * vm, dns_main_t * dm, u8 * name,
 184                        dns_pending_request_t * t, dns_cache_entry_t ** retp);
 185
 186 void
 187 vnet_dns_send_dns6_request (vlib_main_t * vm, dns_main_t * dm,
 188                             dns_cache_entry_t * ep, ip6_address_t * server);
 189 void
 190 vnet_dns_send_dns4_request (vlib_main_t * vm, dns_main_t * dm,
 191                             dns_cache_entry_t * ep, ip4_address_t * server);
 192
 193 void vnet_send_dns4_reply (vlib_main_t * vm, dns_main_t * dm,
 194                            dns_pending_request_t * t, dns_cache_entry_t * ep,
 195                            vlib_buffer_t * b0);
 196
 197 void vnet_send_dns6_reply (vlib_main_t * vm, dns_main_t * dm,
 198                            dns_pending_request_t * t, dns_cache_entry_t * ep,
 199                            vlib_buffer_t * b0);
 200
 201 u8 *vnet_dns_labels_to_name (u8 * label, u8 * full_text,
 202                              u8 ** parse_from_here);
 203
 204 void vnet_dns_create_resolver_process (vlib_main_t * vm, dns_main_t * dm);
 205
 206 format_function_t format_dns_reply;
 207
 208 static inline void
 209 dns_cache_lock (dns_main_t * dm, int tag)
 210 {
 211   if (dm->cache_lock)
 212     {
 213       ASSERT (tag);
 214       ASSERT (dm->cache_lock_tag == 0);
 215       clib_spinlock_lock (&dm->cache_lock);
 216       dm->cache_lock_tag = tag;
 217     }
 218 }
 219
 220 static inline void
 221 dns_cache_unlock (dns_main_t * dm)
 222 {
 223   if (dm->cache_lock)
 224     {
 225       ASSERT (dm->cache_lock_tag);
 226       dm->cache_lock_tag = 0;
 227       clib_spinlock_unlock (&dm->cache_lock);
 228     }
 229 }
 230
 231 extern int dns_resolve_name (u8 *name, dns_cache_entry_t **ep,
 232                              dns_pending_request_t *t0,
 233                              dns_resolve_name_t *rn);
 234 #endif /* included_dns_h */
 235
 236 /*
 237  * fd.io coding-style-patch-verification: ON
 238  *
 239  * Local Variables:
 240  * eval: (c-set-style "gnu")
 241  * End:
 242  */