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/*
* snat_det.h - deterministic nat definitions
*
* 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.
*/
/**
* @file
* @brief deterministic NAT definitions
*/
#ifndef __included_snat_det_h__
#define __included_snat_det_h__
#include <vnet/ip/ip.h>
#include <snat/snat.h>
#define SNAT_DET_SES_PER_USER 1000
int snat_det_add_map (snat_main_t * sm, ip4_address_t * in_addr, u8 in_plen,
ip4_address_t * out_addr, u8 out_plen, int is_add);
always_inline int
is_addr_in_net (ip4_address_t * addr, ip4_address_t * net, u8 plen)
{
if (net->as_u32 == (addr->as_u32 & ip4_main.fib_masks[plen]))
return 1;
return 0;
}
always_inline snat_det_map_t *
snat_det_map_by_user (snat_main_t * sm, ip4_address_t * user_addr)
{
snat_det_map_t *dm;
/* *INDENT-OFF* */
pool_foreach (dm, sm->det_maps,
({
if (is_addr_in_net(user_addr, &dm->in_addr, dm->in_plen))
return dm;
}));
/* *INDENT-ON* */
return 0;
}
always_inline snat_det_map_t *
snat_det_map_by_out (snat_main_t * sm, ip4_address_t * out_addr)
{
snat_det_map_t *dm;
/* *INDENT-OFF* */
pool_foreach (dm, sm->det_maps,
({
if (is_addr_in_net(out_addr, &dm->out_addr, dm->out_plen))
return dm;
}));
/* *INDENT-ON* */
return 0;
}
always_inline void
snat_det_forward (snat_det_map_t * dm, ip4_address_t * in_addr,
ip4_address_t * out_addr, u16 * lo_port)
{
u32 in_offset, out_offset;
in_offset = clib_net_to_host_u32 (in_addr->as_u32) -
clib_net_to_host_u32 (dm->in_addr.as_u32);
out_offset = in_offset / dm->sharing_ratio;
out_addr->as_u32 =
clib_host_to_net_u32 (clib_net_to_host_u32 (dm->out_addr.as_u32) +
out_offset);
*lo_port = 1024 + dm->ports_per_host * (in_offset % dm->sharing_ratio);
}
always_inline void
snat_det_reverse (snat_det_map_t * dm, ip4_address_t * out_addr, u16 out_port,
ip4_address_t * in_addr)
{
u32 in_offset1, in_offset2, out_offset;
out_offset = clib_net_to_host_u32 (out_addr->as_u32) -
clib_net_to_host_u32 (dm->out_addr.as_u32);
in_offset1 = out_offset * dm->sharing_ratio;
in_offset2 = (out_port - 1024) / dm->ports_per_host;
in_addr->as_u32 =
clib_host_to_net_u32 (clib_net_to_host_u32 (dm->in_addr.as_u32) +
in_offset1 + in_offset2);
}
always_inline u32
snat_det_user_ses_offset (ip4_address_t * addr, u8 plen)
{
return (clib_net_to_host_u32 (addr->as_u32) & pow2_mask (32 - plen)) *
SNAT_DET_SES_PER_USER;
}
always_inline snat_det_session_t *
snat_det_get_ses_by_out (snat_det_map_t * dm, ip4_address_t * in_addr,
u64 out_key)
{
u32 user_offset;
u16 i;
user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
{
if (dm->sessions[i + user_offset].out.as_u64 == out_key)
return &dm->sessions[i + user_offset];
}
return 0;
}
always_inline snat_det_session_t *
snat_det_find_ses_by_in (snat_det_map_t * dm, ip4_address_t * in_addr,
u16 in_port, snat_det_out_key_t out_key)
{
snat_det_session_t *ses;
u32 user_offset;
u16 i;
user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
{
ses = &dm->sessions[i + user_offset];
if (ses->in_port == in_port &&
ses->out.ext_host_addr.as_u32 == out_key.ext_host_addr.as_u32 &&
ses->out.ext_host_port == out_key.ext_host_port)
return &dm->sessions[i + user_offset];
}
return 0;
}
always_inline snat_det_session_t *
snat_det_ses_create (snat_det_map_t * dm, ip4_address_t * in_addr,
u16 in_port, snat_det_out_key_t * out)
{
u32 user_offset;
u16 i;
user_offset = snat_det_user_ses_offset (in_addr, dm->in_plen);
for (i = 0; i < SNAT_DET_SES_PER_USER; i++)
{
if (!dm->sessions[i + user_offset].in_port)
{
if (__sync_bool_compare_and_swap
(&dm->sessions[i + user_offset].in_port, 0, in_port))
{
dm->sessions[i + user_offset].out.as_u64 = out->as_u64;
dm->sessions[i + user_offset].state = SNAT_SESSION_UNKNOWN;
dm->sessions[i + user_offset].expire = 0;
__sync_add_and_fetch (&dm->ses_num, 1);
return &dm->sessions[i + user_offset];
}
}
}
return 0;
}
always_inline void
snat_det_ses_close (snat_det_map_t * dm, snat_det_session_t * ses)
{
if (__sync_bool_compare_and_swap (&ses->in_port, ses->in_port, 0))
{
ses->out.as_u64 = 0;
__sync_add_and_fetch (&dm->ses_num, -1);
}
}
#endif /* __included_snat_det_h__ */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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