/* * 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 #include #include #include #include #include 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; 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; uword *cache_lock; /** enable / disable flag */ int is_enabled; /** upstream name servers, e.g. 8.8.8.8 */ ip4_address_t *ip4_name_servers; ip6_address_t *ip6_name_servers; /** config parameters */ u32 name_cache_size; u32 max_ttl_in_seconds; u32 random_seed; /* convenience */ vlib_main_t *vlib_main; vnet_main_t *vnet_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; extern vlib_node_registration_t dns_resolver_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 \ _(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") 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_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); format_function_t format_dns_reply; static inline void dns_cache_lock (dns_main_t * dm) { if (dm->cache_lock) { while (__sync_lock_test_and_set (dm->cache_lock, 1)) ; } } static inline void dns_cache_unlock (dns_main_t * dm) { if (dm->cache_lock) { CLIB_MEMORY_BARRIER (); *dm->cache_lock = 0; } } #endif /* included_dns_h */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */