/*
* decap.c : IPSec tunnel decapsulation
*
* Copyright (c) 2015 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/vnet.h>
#include <vnet/api_errno.h>
#include <vnet/ip/ip.h>
#include <vnet/feature/feature.h>
#include <vnet/ipsec/ipsec.h>
#include <vnet/ipsec/esp.h>
#include <vnet/ipsec/ah.h>
#define foreach_ipsec_input_error \
_(RX_PKTS, "IPSEC pkts received") \
_(DECRYPTION_FAILED, "IPSEC decryption failed")
typedef enum
{
#define _(sym,str) IPSEC_INPUT_ERROR_##sym,
foreach_ipsec_input_error
#undef _
IPSEC_INPUT_N_ERROR,
} ipsec_input_error_t;
static char *ipsec_input_error_strings[] = {
#define _(sym,string) string,
foreach_ipsec_input_error
#undef _
};
typedef struct
{
u32 sa_id;
u32 spi;
u32 seq;
} ipsec_input_trace_t;
/* packet trace format function */
static u8 *
format_ipsec_input_trace (u8 * s, va_list * args)
{
CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
ipsec_input_trace_t *t = va_arg (*args, ipsec_input_trace_t *);
if (t->spi == 0 && t->seq == 0)
{
s = format (s, "esp: no esp packet");
return s;
}
if (t->sa_id != 0)
{
s = format (s, "esp: sa_id %u spi %u seq %u", t->sa_id, t->spi, t->seq);
}
else
{
s = format (s, "esp: no sa spi %u seq %u", t->spi, t->seq);
}
return s;
}
always_inline ipsec_policy_t *
ipsec_input_protect_policy_match (ipsec_spd_t * spd, u32 sa, u32 da, u32 spi)
{
ipsec_main_t *im = &ipsec_main;
ipsec_policy_t *p;
ipsec_sa_t *s;
u32 *i;
vec_foreach (i, spd->ipv4_inbound_protect_policy_indices)
{
p = pool_elt_at_index (spd->policies, *i);
s = pool_elt_at_index (im->sad, p->sa_index);
if (spi != s->spi)
continue;
if (s->is_tunnel)
{
if (da != clib_net_to_host_u32 (s->tunnel_dst_addr.ip4.as_u32))
continue;
if (sa != clib_net_to_host_u32 (s->tunnel_src_addr.ip4.as_u32))
continue;
return p;
}
if (da < clib_net_to_host_u32 (p->laddr.start.ip4.as_u32))
continue;
if (da > clib_net_to_host_u32 (p->laddr.stop.ip4.as_u32))
continue;
if (sa < clib_net_to_host_u32 (p->raddr.start.ip4.as_u32))
continue;
if (sa > clib_net_to_host_u32 (p->raddr.stop.ip4.as_u32))
continue;
return p;
}
return 0;
}
always_inline uword
ip6_addr_match_range (ip6_address_t * a, ip6_address_t * la,
ip6_address_t * ua)
{
if ((memcmp (a->as_u64, la->as_u64, 2 * sizeof (u64)) >= 0) &&
(memcmp (a->as_u64, ua->as_u64, 2 * sizeof (u64)) <= 0))
return 1;
return 0;
}
always_inline ipsec_policy_t *
ipsec_input_ip6_protect_policy_match (ipsec_spd_t * spd,
ip6_address_t * sa,
ip6_address_t * da, u32 spi)
{
ipsec_main_t *im = &ipsec_main;
ipsec_policy_t *p;
ipsec_sa_t *s;
u32 *i;
vec_foreach (i, spd->ipv6_inbound_protect_policy_indices)
{
p = pool_elt_at_index (spd->policies, *i);
s = pool_elt_at_index (im->sad, p->sa_index);
if (spi != s->spi)
continue;
if (s->is_tunnel)
{
if (!ip6_address_is_equal (sa, &s->tunnel_src_addr.ip6))
continue;
if (!ip6_address_is_equal (da, &s->tunnel_dst_addr.ip6))
continue;
return p;
}
if (!ip6_addr_match_range (sa, &p->raddr.start.ip6, &p->raddr.stop.ip6))
continue;
if (!ip6_addr_match_range (da, &p->laddr.start.ip6, &p->laddr.stop.ip6))
continue;
return p;
}
return 0;
}
static vlib_node_registration_t ipsec_input_ip4_node;
static uword
ipsec_input_ip4_node_fn (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * from_frame)
{
u32 n_left_from, *from, next_index, *to_next;
ipsec_main_t *im = &ipsec_main;
from = vlib_frame_vector_args (from_frame);
n_left_from = from_frame->n_vectors;
next_index = node->cached_next_index;
while (n_left_from > 0)
{
u32 n_left_to_next;
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left_from > 0 && n_left_to_next > 0)
{
u32 bi0, next0;
vlib_buffer_t *b0;
ip4_header_t *ip0;
esp_header_t *esp0;
ah_header_t *ah0;
ip4_ipsec_config_t *c0;
ipsec_spd_t *spd0;
ipsec_policy_t *p0 = 0;
bi0 = to_next[0] = from[0];
from += 1;
n_left_from -= 1;
to_next += 1;
n_left_to_next -= 1;
b0 = vlib_get_buffer (vm, bi0);
c0 =
vnet_feature_next_with_data (vnet_buffer (b0)->sw_if_index
[VLIB_RX], &next0, b0,
sizeof (c0[0]));
spd0 = pool_elt_at_index (im->spds, c0->spd_index);
ip0 = vlib_buffer_get_current (b0);
if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
{
#if 0
clib_warning
("packet received from %U to %U spi %u size %u spd_id %u",
format_ip4_address, ip0->src_address.as_u8,
format_ip4_address, ip0->dst_address.as_u8,
clib_net_to_host_u32 (esp0->spi),
clib_net_to_host_u16 (ip0->length), spd0->id);
#endif
esp0 = (esp_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
p0 = ipsec_input_protect_policy_match (spd0,
clib_net_to_host_u32
(ip0->src_address.
as_u32),
clib_net_to_host_u32
(ip0->dst_address.
as_u32),
clib_net_to_host_u32
(esp0->spi));
if (PREDICT_TRUE (p0 != 0))
{
p0->counter.packets++;
p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
vnet_buffer (b0)->ipsec.flags = 0;
next0 = im->esp_decrypt_next_index;
vlib_buffer_advance (b0, ip4_header_bytes (ip0));
goto trace0;
}
/* FIXME bypass and discard */
trace0:
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
ipsec_input_trace_t *tr =
vlib_add_trace (vm, node, b0, sizeof (*tr));
if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
{
if (p0)
tr->sa_id = p0->sa_id;
tr->spi = clib_host_to_net_u32 (esp0->spi);
tr->seq = clib_host_to_net_u32 (esp0->seq);
}
}
}
if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_AH))
{
ah0 = (ah_header_t *) ((u8 *) ip0 + ip4_header_bytes (ip0));
p0 = ipsec_input_protect_policy_match (spd0,
clib_net_to_host_u32
(ip0->src_address.
as_u32),
clib_net_to_host_u32
(ip0->dst_address.
as_u32),
clib_net_to_host_u32
(ah0->spi));
if (PREDICT_TRUE (p0 != 0))
{
p0->counter.packets++;
p0->counter.bytes += clib_net_to_host_u16 (ip0->length);
vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
vnet_buffer (b0)->ipsec.flags = 0;
next0 = im->ah_decrypt_next_index;
goto trace1;
}
/* FIXME bypass and discard */
trace1:
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
ipsec_input_trace_t *tr =
vlib_add_trace (vm, node, b0, sizeof (*tr));
if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
{
if (p0)
tr->sa_id = p0->sa_id;
tr->spi = clib_host_to_net_u32 (ah0->spi);
tr->seq = clib_host_to_net_u32 (ah0->seq_no);
}
}
}
vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
to_next, n_left_to_next, bi0,
next0);
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
vlib_node_increment_counter (vm, ipsec_input_ip4_node.index,
IPSEC_INPUT_ERROR_RX_PKTS,
from_frame->n_vectors);
return from_frame->n_vectors;
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ipsec_input_ip4_node,static) = {
.function = ipsec_input_ip4_node_fn,
.name = "ipsec-input-ip4",
.vector_size = sizeof (u32),
.format_trace = format_ipsec_input_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(ipsec_input_error_strings),
.error_strings = ipsec_input_error_strings,
.n_next_nodes = IPSEC_INPUT_N_NEXT,
.next_nodes = {
#define _(s,n) [IPSEC_INPUT_NEXT_##s] = n,
foreach_ipsec_input_next
#undef _
},
};
/* *INDENT-ON* */
VLIB_NODE_FUNCTION_MULTIARCH (ipsec_input_ip4_node, ipsec_input_ip4_node_fn)
static vlib_node_registration_t ipsec_input_ip6_node;
static uword
ipsec_input_ip6_node_fn (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * from_frame)
{
u32 n_left_from, *from, next_index, *to_next;
ipsec_main_t *im = &ipsec_main;
from = vlib_frame_vector_args (from_frame);
n_left_from = from_frame->n_vectors;
next_index = node->cached_next_index;
while (n_left_from > 0)
{
u32 n_left_to_next;
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left_from > 0 && n_left_to_next > 0)
{
u32 bi0, next0;
vlib_buffer_t *b0;
ip6_header_t *ip0;
esp_header_t *esp0;
ip4_ipsec_config_t *c0;
ipsec_spd_t *spd0;
ipsec_policy_t *p0 = 0;
u32 header_size = sizeof (ip0[0]);
bi0 = to_next[0] = from[0];
from += 1;
n_left_from -= 1;
to_next += 1;
n_left_to_next -= 1;
b0 = vlib_get_buffer (vm, bi0);
c0 =
vnet_feature_next_with_data (vnet_buffer (b0)->sw_if_index
[VLIB_RX], &next0, b0,
sizeof (c0[0]));
spd0 = pool_elt_at_index (im->spds, c0->spd_index);
ip0 = vlib_buffer_get_current (b0);
esp0 = (esp_header_t *) ((u8 *) ip0 + header_size);
if (PREDICT_TRUE (ip0->protocol == IP_PROTOCOL_IPSEC_ESP))
{
#if 0
clib_warning
("packet received from %U to %U spi %u size %u spd_id %u",
format_ip6_address, &ip0->src_address, format_ip6_address,
&ip0->dst_address, clib_net_to_host_u32 (esp0->spi),
clib_net_to_host_u16 (ip0->payload_length) + header_size,
spd0->id);
#endif
p0 = ipsec_input_ip6_protect_policy_match (spd0,
&ip0->src_address,
&ip0->dst_address,
clib_net_to_host_u32
(esp0->spi));
if (PREDICT_TRUE (p0 != 0))
{
p0->counter.packets++;
p0->counter.bytes +=
clib_net_to_host_u16 (ip0->payload_length);
p0->counter.bytes += header_size;
vnet_buffer (b0)->ipsec.sad_index = p0->sa_index;
vnet_buffer (b0)->ipsec.flags = 0;
next0 = im->esp_decrypt_next_index;
vlib_buffer_advance (b0, header_size);
goto trace0;
}
}
trace0:
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
ipsec_input_trace_t *tr =
vlib_add_trace (vm, node, b0, sizeof (*tr));
if (ip0->protocol == IP_PROTOCOL_IPSEC_ESP)
{
if (p0)
tr->sa_id = p0->sa_id;
tr->spi = clib_host_to_net_u32 (esp0->spi);
tr->seq = clib_host_to_net_u32 (esp0->seq);
}
}
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi0, next0);
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
vlib_node_increment_counter (vm, ipsec_input_ip6_node.index,
IPSEC_INPUT_ERROR_RX_PKTS,
from_frame->n_vectors);
return from_frame->n_vectors;
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ipsec_input_ip6_node,static) = {
.function = ipsec_input_ip6_node_fn,
.name = "ipsec-input-ip6",
.vector_size = sizeof (u32),
.format_trace = format_ipsec_input_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(ipsec_input_error_strings),
.error_strings = ipsec_input_error_strings,
.sibling_of = "ipsec-input-ip4",
};
/* *INDENT-ON* */
VLIB_NODE_FUNCTION_MULTIARCH (ipsec_input_ip6_node, ipsec_input_ip6_node_fn)
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/