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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.
*/
#include <vnet/ip/ip.h>
#include <cnat/cnat_snat.h>
static void
cnat_compute_prefix_lengths_in_search_order (cnat_snat_pfx_table_t *
table, ip_address_family_t af)
{
int i;
vec_reset_length (table->meta[af].prefix_lengths_in_search_order);
/* Note: bitmap reversed so this is in fact a longest prefix match */
/* *INDENT-OFF* */
clib_bitmap_foreach (i, table->meta[af].non_empty_dst_address_length_bitmap,
({
int dst_address_length = 128 - i;
vec_add1 (table->meta[af].prefix_lengths_in_search_order, dst_address_length);
}));
/* *INDENT-ON* */
}
int
cnat_add_snat_prefix (ip_prefix_t * pfx)
{
/* All packets destined to this prefix won't be source-NAT-ed */
cnat_snat_pfx_table_t *table = &cnat_main.snat_pfx_table;
clib_bihash_kv_24_8_t kv;
ip6_address_t *mask;
u64 af = ip_prefix_version (pfx);;
mask = &table->ip_masks[pfx->len];
if (AF_IP4 == af)
{
kv.key[0] = (u64) ip_prefix_v4 (pfx).as_u32 & mask->as_u64[0];
kv.key[1] = 0;
}
else
{
kv.key[0] = ip_prefix_v6 (pfx).as_u64[0] & mask->as_u64[0];
kv.key[1] = ip_prefix_v6 (pfx).as_u64[1] & mask->as_u64[1];
}
kv.key[2] = ((u64) af << 32) | pfx->len;
clib_bihash_add_del_24_8 (&table->ip_hash, &kv, 1 /* is_add */ );
table->meta[af].dst_address_length_refcounts[pfx->len]++;
table->meta[af].non_empty_dst_address_length_bitmap =
clib_bitmap_set (table->meta[af].non_empty_dst_address_length_bitmap,
128 - pfx->len, 1);
cnat_compute_prefix_lengths_in_search_order (table, af);
return 0;
}
int
cnat_del_snat_prefix (ip_prefix_t * pfx)
{
cnat_snat_pfx_table_t *table = &cnat_main.snat_pfx_table;
clib_bihash_kv_24_8_t kv, val;
ip6_address_t *mask;
u64 af = ip_prefix_version (pfx);;
mask = &table->ip_masks[pfx->len];
if (AF_IP4 == af)
{
kv.key[0] = (u64) ip_prefix_v4 (pfx).as_u32 & mask->as_u64[0];
kv.key[1] = 0;
}
else
{
kv.key[0] = ip_prefix_v6 (pfx).as_u64[0] & mask->as_u64[0];
kv.key[1] = ip_prefix_v6 (pfx).as_u64[1] & mask->as_u64[1];
}
kv.key[2] = ((u64) af << 32) | pfx->len;
if (clib_bihash_search_24_8 (&table->ip_hash, &kv, &val))
{
return 1;
}
clib_bihash_add_del_24_8 (&table->ip_hash, &kv, 0 /* is_add */ );
/* refcount accounting */
ASSERT (table->meta[af].dst_address_length_refcounts[pfx->len] > 0);
if (--table->meta[af].dst_address_length_refcounts[pfx->len] == 0)
{
table->meta[af].non_empty_dst_address_length_bitmap =
clib_bitmap_set (table->meta[af].non_empty_dst_address_length_bitmap,
128 - pfx->len, 0);
cnat_compute_prefix_lengths_in_search_order (table, af);
}
return 0;
}
u8 *
format_cnat_snat_prefix (u8 * s, va_list * args)
{
clib_bihash_kv_24_8_t *kv = va_arg (*args, clib_bihash_kv_24_8_t *);
CLIB_UNUSED (int verbose) = va_arg (*args, int);
u32 af = kv->key[2] >> 32;
u32 len = kv->key[2] & 0xffffffff;
if (AF_IP4 == af)
s = format (s, "%U/%d", format_ip4_address, &kv->key[0], len);
else
s = format (s, "%U/%d", format_ip6_address, &kv->key[0], len);
return (s);
}
static clib_error_t *
cnat_set_snat (vlib_main_t * vm,
unformat_input_t * input, vlib_cli_command_t * cmd)
{
ip_address_t addr;
while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
{
if (unformat (input, "%U", unformat_ip_address, &addr))
{
if (ip_addr_version (&addr) == AF_IP4)
clib_memcpy (&cnat_main.snat_ip4, &ip_addr_v4 (&addr),
sizeof (ip4_address_t));
else
clib_memcpy (&cnat_main.snat_ip6, &ip_addr_v6 (&addr),
sizeof (ip6_address_t));
}
else
return (clib_error_return (0, "unknown input '%U'",
format_unformat_error, input));
}
return (NULL);
}
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (cnat_set_snat_command, static) =
{
.path = "cnat snat with",
.short_help = "cnat snat with [ip]",
.function = cnat_set_snat,
};
/* *INDENT-ON* */
static clib_error_t *
cnat_snat_exclude (vlib_main_t * vm,
unformat_input_t * input, vlib_cli_command_t * cmd)
{
ip_prefix_t pfx;
u8 is_add = 1;
int rv;
while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
{
if (unformat (input, "%U", unformat_ip_prefix, &pfx))
;
else if (unformat (input, "del"))
is_add = 0;
else
return (clib_error_return (0, "unknown input '%U'",
format_unformat_error, input));
}
if (is_add)
rv = cnat_add_snat_prefix (&pfx);
else
rv = cnat_del_snat_prefix (&pfx);
if (rv)
{
return (clib_error_return (0, "error %d", rv, input));
}
return (NULL);
}
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (cnat_snat_exclude_command, static) =
{
.path = "cnat snat exclude",
.short_help = "cnat snat exclude [ip]",
.function = cnat_snat_exclude,
};
/* *INDENT-ON* */
static clib_error_t *
cnat_show_snat (vlib_main_t * vm,
unformat_input_t * input, vlib_cli_command_t * cmd)
{
cnat_snat_pfx_table_t *table = &cnat_main.snat_pfx_table;
vlib_cli_output (vm, "Source NAT\nip4: %U\nip6: %U\n",
format_ip4_address, &cnat_main.snat_ip4,
format_ip6_address, &cnat_main.snat_ip6);
vlib_cli_output (vm, "Prefixes:\n%U\n",
format_bihash_24_8, &table->ip_hash, 1);
return (NULL);
}
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (cnat_show_snat_command, static) =
{
.path = "show cnat snat",
.short_help = "show cnat snat",
.function = cnat_show_snat,
};
/* *INDENT-ON* */
static clib_error_t *
cnat_snat_init (vlib_main_t * vm)
{
cnat_snat_pfx_table_t *table = &cnat_main.snat_pfx_table;
cnat_main_t *cm = &cnat_main;
int i;
for (i = 0; i < ARRAY_LEN (table->ip_masks); i++)
{
u32 j, i0, i1;
i0 = i / 32;
i1 = i % 32;
for (j = 0; j < i0; j++)
table->ip_masks[i].as_u32[j] = ~0;
if (i1)
table->ip_masks[i].as_u32[i0] =
clib_host_to_net_u32 (pow2_mask (i1) << (32 - i1));
}
clib_bihash_init_24_8 (&table->ip_hash, "snat prefixes",
cm->snat_hash_buckets, cm->snat_hash_memory);
clib_bihash_set_kvp_format_fn_24_8 (&table->ip_hash,
format_cnat_snat_prefix);
return (NULL);
}
VLIB_INIT_FUNCTION (cnat_snat_init);
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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