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/*
* Copyright (c) 2020 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 __CNAT_CLIENT_H__
#define __CNAT_CLIENT_H__
#include <cnat/cnat_types.h>
#include <vppinfra/bihash_16_8.h>
/**
* A client is a representation of an IP address behind the NAT.
* A client thus sends packet to a VIP.
* Clients are learned in the Data-plane when they send packets,
* but, since they make additions to the FIB they must be programmed
* in the main thread. They are aged out when they become idle.
*
* A client interposes in the FIB graph for the prefix corresponding
* to the client (e.g. client's-IP/32). As a result this client object
* is cloned as the interpose DPO. The clones are removed when the lock
* count drops to zero. The originals are removed when the client ages.
* At forwarding time the client preforms the reverse translation and
* then ships the packet to where the FIB would send it.
*/
typedef struct cnat_client_t_
{
CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
/**
* the client's IP address
*/
ip_address_t cc_ip;
/**
* How to send packets to this client post translation
*/
dpo_id_t cc_parent;
/**
* the FIB entry this client sources
*/
fib_node_index_t cc_fei;
/**
* number of DPO locks
*/
u32 cc_locks;
/**
* Translations refcount for cleanup
*/
u32 tr_refcnt;
/**
* Session refcount for cleanup
*/
u32 session_refcnt;
/**
* Parent cnat_client index if cloned via interpose
* or own index if vanilla client.
* Used to get translations & update session_refcnt
*/
index_t parent_cci;
/**
* Client flags
*/
u8 flags;
} cnat_client_t;
extern u8 *format_cnat_client (u8 * s, va_list * args);
extern void cnat_client_free_by_ip (ip46_address_t * addr, u8 af);
extern cnat_client_t *cnat_client_pool;
extern dpo_type_t cnat_client_dpo;
static_always_inline cnat_client_t *
cnat_client_get (index_t i)
{
return (pool_elt_at_index (cnat_client_pool, i));
}
/**
* A translation that references this VIP was deleted
*/
extern void cnat_client_translation_deleted (index_t cci);
/**
* A translation that references this VIP was added
*/
extern void cnat_client_translation_added (index_t cci);
/**
* Called in the main thread by RPC from the workers to learn a
* new client
*/
extern void cnat_client_learn (const ip_address_t *addr);
extern index_t cnat_client_add (const ip_address_t * ip, u8 flags);
/**
* Check all the clients were purged by translation & session purge
*/
extern int cnat_client_purge (void);
/**
* CNat Client (dpo) flags
*/
typedef enum
{
/* IP already present in the FIB, need to interpose dpo */
CNAT_FLAG_EXCLUSIVE = (1 << 1),
} cnat_entry_flag_t;
extern void cnat_client_throttle_pool_process ();
/**
* DB of clients
*/
typedef struct cnat_client_db_t_
{
clib_bihash_16_8_t cc_ip_id_hash;
/* Pool of addresses that have been throttled
and need to be refcounted before calling
cnat_client_free_by_ip */
clib_spinlock_t throttle_lock;
uword *throttle_mem;
} cnat_client_db_t;
extern cnat_client_db_t cnat_client_db;
/**
* Find a client from an IP4 address
*/
static_always_inline cnat_client_t *
cnat_client_ip4_find (const ip4_address_t * ip)
{
clib_bihash_kv_16_8_t bkey, bval;
bkey.key[0] = ip->as_u32;
bkey.key[1] = 0;
if (clib_bihash_search_16_8 (&cnat_client_db.cc_ip_id_hash, &bkey, &bval))
return (NULL);
return (pool_elt_at_index (cnat_client_pool, bval.value));
}
/**
* Find a client from an IP6 address
*/
static_always_inline cnat_client_t *
cnat_client_ip6_find (const ip6_address_t * ip)
{
clib_bihash_kv_16_8_t bkey, bval;
bkey.key[0] = ip->as_u64[0];
bkey.key[1] = ip->as_u64[1];
if (clib_bihash_search_16_8 (&cnat_client_db.cc_ip_id_hash, &bkey, &bval))
return (NULL);
return (pool_elt_at_index (cnat_client_pool, bval.value));
}
/**
* Add a session refcnt to this client
*/
static_always_inline u32
cnat_client_cnt_session (cnat_client_t * cc)
{
cnat_client_t *ccp = cnat_client_get (cc->parent_cci);
return clib_atomic_add_fetch (&ccp->session_refcnt, 1);
}
/**
* Del a session refcnt to this client
*/
static_always_inline u32
cnat_client_uncnt_session (cnat_client_t * cc)
{
cnat_client_t *ccp = cnat_client_get (cc->parent_cci);
return clib_atomic_sub_fetch (&ccp->session_refcnt, 1);
}
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
#endif
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