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/*
* Copyright (c) 2018 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.
*/
/**
* @file
* @brief NAT plugin client-IP based session affinity for load-balancing
*/
#include <nat/nat_affinity.h>
#include <nat/nat.h>
nat_affinity_main_t nat_affinity_main;
#define AFFINITY_HASH_BUCKETS 65536
#define AFFINITY_HASH_MEMORY (2 << 25)
u8 *
format_affinity_kvp (u8 * s, va_list * args)
{
clib_bihash_kv_16_8_t *v = va_arg (*args, clib_bihash_kv_16_8_t *);
nat_affinity_key_t k;
k.as_u64[0] = v->key[0];
k.as_u64[1] = v->key[1];
s = format (s, "client %U backend %U:%d proto %U index %llu",
format_ip4_address, &k.client_addr,
format_ip4_address, &k.service_addr,
clib_net_to_host_u16 (k.service_port),
format_nat_protocol, k.proto);
return s;
}
clib_error_t *
nat_affinity_init (vlib_main_t * vm)
{
nat_affinity_main_t *nam = &nat_affinity_main;
vlib_thread_main_t *tm = vlib_get_thread_main ();
clib_error_t *error = 0;
if (tm->n_vlib_mains > 1)
clib_spinlock_init (&nam->affinity_lock);
clib_bihash_init_16_8 (&nam->affinity_hash, "nat-affinity",
AFFINITY_HASH_BUCKETS, AFFINITY_HASH_MEMORY);
clib_bihash_set_kvp_format_fn_16_8 (&nam->affinity_hash,
format_affinity_kvp);
nam->vlib_main = vm;
return error;
}
static_always_inline void
make_affinity_kv (clib_bihash_kv_16_8_t * kv, ip4_address_t client_addr,
ip4_address_t service_addr, u8 proto, u16 service_port)
{
nat_affinity_key_t *key = (nat_affinity_key_t *) kv->key;
key->client_addr = client_addr;
key->service_addr = service_addr;
key->proto = proto;
key->service_port = service_port;
kv->value = ~0ULL;
}
u32
nat_affinity_get_per_service_list_head_index (void)
{
nat_affinity_main_t *nam = &nat_affinity_main;
dlist_elt_t *head_elt;
clib_spinlock_lock_if_init (&nam->affinity_lock);
pool_get (nam->list_pool, head_elt);
clib_dlist_init (nam->list_pool, head_elt - nam->list_pool);
clib_spinlock_unlock_if_init (&nam->affinity_lock);
return head_elt - nam->list_pool;
}
void
nat_affinity_flush_service (u32 affinity_per_service_list_head_index)
{
nat_affinity_main_t *nam = &nat_affinity_main;
u32 elt_index;
dlist_elt_t *elt;
nat_affinity_t *a;
clib_bihash_kv_16_8_t kv;
clib_spinlock_lock_if_init (&nam->affinity_lock);
while ((elt_index =
clib_dlist_remove_head (nam->list_pool,
affinity_per_service_list_head_index)) !=
~0)
{
elt = pool_elt_at_index (nam->list_pool, elt_index);
a = pool_elt_at_index (nam->affinity_pool, elt->value);
kv.key[0] = a->key.as_u64[0];
kv.key[1] = a->key.as_u64[1];
pool_put_index (nam->affinity_pool, elt->value);
if (clib_bihash_add_del_16_8 (&nam->affinity_hash, &kv, 0))
nat_elog_warn ("affinity key del failed");
pool_put_index (nam->list_pool, elt_index);
}
pool_put_index (nam->list_pool, affinity_per_service_list_head_index);
clib_spinlock_unlock_if_init (&nam->affinity_lock);
}
int
nat_affinity_find_and_lock (ip4_address_t client_addr,
ip4_address_t service_addr, u8 proto,
u16 service_port, u8 * backend_index)
{
nat_affinity_main_t *nam = &nat_affinity_main;
clib_bihash_kv_16_8_t kv, value;
nat_affinity_t *a;
int rv = 0;
make_affinity_kv (&kv, client_addr, service_addr, proto, service_port);
clib_spinlock_lock_if_init (&nam->affinity_lock);
if (clib_bihash_search_16_8 (&nam->affinity_hash, &kv, &value))
{
rv = 1;
goto unlock;
}
a = pool_elt_at_index (nam->affinity_pool, value.value);
/* if already expired delete */
if (a->ref_cnt == 0)
{
if (a->expire < vlib_time_now (nam->vlib_main))
{
clib_dlist_remove (nam->list_pool, a->per_service_index);
pool_put_index (nam->list_pool, a->per_service_index);
pool_put_index (nam->affinity_pool, value.value);
if (clib_bihash_add_del_16_8 (&nam->affinity_hash, &kv, 0))
nat_elog_warn ("affinity key del failed");
rv = 1;
goto unlock;
}
}
a->ref_cnt++;
*backend_index = a->backend_index;
unlock:
clib_spinlock_unlock_if_init (&nam->affinity_lock);
return rv;
}
static int
affinity_is_expired_cb (clib_bihash_kv_16_8_t * kv, void *arg)
{
nat_affinity_main_t *nam = &nat_affinity_main;
nat_affinity_t *a;
a = pool_elt_at_index (nam->affinity_pool, kv->value);
if (a->ref_cnt == 0)
{
if (a->expire < vlib_time_now (nam->vlib_main))
{
clib_dlist_remove (nam->list_pool, a->per_service_index);
pool_put_index (nam->list_pool, a->per_service_index);
pool_put_index (nam->affinity_pool, kv->value);
if (clib_bihash_add_del_16_8 (&nam->affinity_hash, kv, 0))
nat_elog_warn ("affinity key del failed");
return 1;
}
}
return 0;
}
int
nat_affinity_create_and_lock (ip4_address_t client_addr,
ip4_address_t service_addr, u8 proto,
u16 service_port, u8 backend_index,
u32 sticky_time,
u32 affinity_per_service_list_head_index)
{
nat_affinity_main_t *nam = &nat_affinity_main;
clib_bihash_kv_16_8_t kv, value;
nat_affinity_t *a;
dlist_elt_t *list_elt;
int rv = 0;
make_affinity_kv (&kv, client_addr, service_addr, proto, service_port);
clib_spinlock_lock_if_init (&nam->affinity_lock);
if (!clib_bihash_search_16_8 (&nam->affinity_hash, &kv, &value))
{
rv = 1;
nat_elog_notice ("affinity key already exist");
goto unlock;
}
pool_get (nam->affinity_pool, a);
kv.value = a - nam->affinity_pool;
rv =
clib_bihash_add_or_overwrite_stale_16_8 (&nam->affinity_hash, &kv,
affinity_is_expired_cb, NULL);
if (rv)
{
nat_elog_notice ("affinity key add failed");
pool_put (nam->affinity_pool, a);
goto unlock;
}
pool_get (nam->list_pool, list_elt);
clib_dlist_init (nam->list_pool, list_elt - nam->list_pool);
list_elt->value = a - nam->affinity_pool;
a->per_service_index = list_elt - nam->list_pool;
a->backend_index = backend_index;
a->ref_cnt = 1;
a->sticky_time = sticky_time;
a->key.as_u64[0] = kv.key[0];
a->key.as_u64[1] = kv.key[1];
clib_dlist_addtail (nam->list_pool, affinity_per_service_list_head_index,
a->per_service_index);
unlock:
clib_spinlock_unlock_if_init (&nam->affinity_lock);
return rv;
}
void
nat_affinity_unlock (ip4_address_t client_addr, ip4_address_t service_addr,
u8 proto, u16 service_port)
{
nat_affinity_main_t *nam = &nat_affinity_main;
clib_bihash_kv_16_8_t kv, value;
nat_affinity_t *a;
make_affinity_kv (&kv, client_addr, service_addr, proto, service_port);
clib_spinlock_lock_if_init (&nam->affinity_lock);
if (clib_bihash_search_16_8 (&nam->affinity_hash, &kv, &value))
goto unlock;
a = pool_elt_at_index (nam->affinity_pool, value.value);
a->ref_cnt--;
if (a->ref_cnt == 0)
a->expire = (u64) a->sticky_time + vlib_time_now (nam->vlib_main);
unlock:
clib_spinlock_unlock_if_init (&nam->affinity_lock);
}
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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