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/*
* 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 <vnet/dns/dns_packet.h>
#include <vnet/ip/ip.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;
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 \
_(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")
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);
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:
*/
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