/*
* ah_encrypt.c : IPSec AH encrypt node
*
* 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/ipsec/ipsec.h>
#include <vnet/ipsec/esp.h>
#include <vnet/ipsec/ah.h>
#define foreach_ah_encrypt_next \
_(DROP, "error-drop") \
_(IP4_LOOKUP, "ip4-lookup") \
_(IP6_LOOKUP, "ip6-lookup") \
_(INTERFACE_OUTPUT, "interface-output")
#define _(v, s) AH_ENCRYPT_NEXT_##v,
typedef enum
{
foreach_ah_encrypt_next
#undef _
AH_ENCRYPT_N_NEXT,
} ah_encrypt_next_t;
#define foreach_ah_encrypt_error \
_(RX_PKTS, "AH pkts received") \
_(SEQ_CYCLED, "sequence number cycled")
typedef enum
{
#define _(sym,str) AH_ENCRYPT_ERROR_##sym,
foreach_ah_encrypt_error
#undef _
AH_ENCRYPT_N_ERROR,
} ah_encrypt_error_t;
static char *ah_encrypt_error_strings[] = {
#define _(sym,string) string,
foreach_ah_encrypt_error
#undef _
};
vlib_node_registration_t ah_encrypt_node;
typedef struct
{
u32 spi;
u32 seq;
ipsec_integ_alg_t integ_alg;
} ah_encrypt_trace_t;
/* packet trace format function */
static u8 *
format_ah_encrypt_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 *);
ah_encrypt_trace_t *t = va_arg (*args, ah_encrypt_trace_t *);
s = format (s, "ah: spi %u seq %u integrity %U",
t->spi, t->seq, format_ipsec_integ_alg, t->integ_alg);
return s;
}
static uword
ah_encrypt_node_fn (vlib_main_t * vm,
vlib_node_runtime_t * node, vlib_frame_t * from_frame)
{
u32 n_left_from, *from, *to_next = 0, next_index;
int icv_size = 0;
from = vlib_frame_vector_args (from_frame);
n_left_from = from_frame->n_vectors;
ipsec_main_t *im = &ipsec_main;
ipsec_proto_main_t *em = &ipsec_proto_main;
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 i_bi0, next0;
vlib_buffer_t *i_b0 = 0;
u32 sa_index0;
ipsec_sa_t *sa0;
ip4_and_ah_header_t *ih0, *oh0 = 0;
ip6_and_ah_header_t *ih6_0, *oh6_0 = 0;
u8 is_ipv6;
u8 ip_hdr_size;
u8 next_hdr_type;
u8 transport_mode = 0;
u8 tos = 0;
u8 ttl = 0;
i_bi0 = from[0];
from += 1;
n_left_from -= 1;
n_left_to_next -= 1;
next0 = AH_ENCRYPT_NEXT_DROP;
i_b0 = vlib_get_buffer (vm, i_bi0);
to_next[0] = i_bi0;
to_next += 1;
sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
sa0 = pool_elt_at_index (im->sad, sa_index0);
if (PREDICT_FALSE (esp_seq_advance (sa0)))
{
clib_warning ("sequence number counter has cycled SPI %u",
sa0->spi);
vlib_node_increment_counter (vm, ah_encrypt_node.index,
AH_ENCRYPT_ERROR_SEQ_CYCLED, 1);
//TODO need to confirm if below is needed
to_next[0] = i_bi0;
to_next += 1;
goto trace;
}
sa0->total_data_size += i_b0->current_length;
ssize_t adv;
ih0 = vlib_buffer_get_current (i_b0);
ttl = ih0->ip4.ttl;
tos = ih0->ip4.tos;
is_ipv6 = (ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60;
/* is ipv6 */
if (PREDICT_TRUE (sa0->is_tunnel))
{
if (PREDICT_TRUE (!is_ipv6))
adv = -sizeof (ip4_and_ah_header_t);
else
adv = -sizeof (ip6_and_ah_header_t);
}
else
{
adv = -sizeof (ah_header_t);
}
icv_size =
em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
/*transport mode save the eth header before it is overwritten */
if (PREDICT_FALSE (!sa0->is_tunnel))
{
ethernet_header_t *ieh0 = (ethernet_header_t *)
((u8 *) vlib_buffer_get_current (i_b0) -
sizeof (ethernet_header_t));
ethernet_header_t *oeh0 =
(ethernet_header_t *) ((u8 *) ieh0 + (adv - icv_size));
clib_memcpy (oeh0, ieh0, sizeof (ethernet_header_t));
}
vlib_buffer_advance (i_b0, adv - icv_size);
/* is ipv6 */
if (PREDICT_FALSE (is_ipv6))
{
ih6_0 = (ip6_and_ah_header_t *) ih0;
ip_hdr_size = sizeof (ip6_header_t);
oh6_0 = vlib_buffer_get_current (i_b0);
if (PREDICT_TRUE (sa0->is_tunnel))
{
next_hdr_type = IP_PROTOCOL_IPV6;
oh6_0->ip6.ip_version_traffic_class_and_flow_label =
ih6_0->ip6.ip_version_traffic_class_and_flow_label;
}
else
{
next_hdr_type = ih6_0->ip6.protocol;
memmove (oh6_0, ih6_0, sizeof (ip6_header_t));
}
oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_AH;
oh6_0->ip6.hop_limit = 254;
oh6_0->ah.spi = clib_net_to_host_u32 (sa0->spi);
oh6_0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
oh6_0->ip6.payload_length =
clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0) -
sizeof (ip6_header_t));
}
else
{
ip_hdr_size = sizeof (ip4_header_t);
oh0 = vlib_buffer_get_current (i_b0);
memset (oh0, 0, sizeof (ip4_and_ah_header_t));
if (PREDICT_TRUE (sa0->is_tunnel))
{
next_hdr_type = IP_PROTOCOL_IP_IN_IP;
}
else
{
next_hdr_type = ih0->ip4.protocol;
memmove (oh0, ih0, sizeof (ip4_header_t));
}
oh0->ip4.length =
clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, i_b0));
oh0->ip4.ip_version_and_header_length = 0x45;
oh0->ip4.fragment_id = 0;
oh0->ip4.flags_and_fragment_offset = 0;
oh0->ip4.ttl = 0;
oh0->ip4.tos = 0;
oh0->ip4.protocol = IP_PROTOCOL_IPSEC_AH;
oh0->ah.spi = clib_net_to_host_u32 (sa0->spi);
oh0->ah.seq_no = clib_net_to_host_u32 (sa0->seq);
oh0->ip4.checksum = 0;
oh0->ah.nexthdr = next_hdr_type;
oh0->ah.hdrlen = 4;
}
if (PREDICT_TRUE
(!is_ipv6 && sa0->is_tunnel && !sa0->is_tunnel_ip6))
{
oh0->ip4.src_address.as_u32 = sa0->tunnel_src_addr.ip4.as_u32;
oh0->ip4.dst_address.as_u32 = sa0->tunnel_dst_addr.ip4.as_u32;
next0 = AH_ENCRYPT_NEXT_IP4_LOOKUP;
vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
}
else if (is_ipv6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
{
oh6_0->ip6.src_address.as_u64[0] =
sa0->tunnel_src_addr.ip6.as_u64[0];
oh6_0->ip6.src_address.as_u64[1] =
sa0->tunnel_src_addr.ip6.as_u64[1];
oh6_0->ip6.dst_address.as_u64[0] =
sa0->tunnel_dst_addr.ip6.as_u64[0];
oh6_0->ip6.dst_address.as_u64[1] =
sa0->tunnel_dst_addr.ip6.as_u64[1];
next0 = AH_ENCRYPT_NEXT_IP6_LOOKUP;
vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
}
else
{
transport_mode = 1;
next0 = AH_ENCRYPT_NEXT_INTERFACE_OUTPUT;
}
u8 sig[64];
memset (sig, 0, sizeof (sig));
u8 *digest = NULL;
{
digest = vlib_buffer_get_current (i_b0) + ip_hdr_size + icv_size;
memset (digest, 0, icv_size);
}
hmac_calc (sa0->integ_alg, sa0->integ_key,
sa0->integ_key_len,
(u8 *) vlib_buffer_get_current (i_b0),
i_b0->current_length, sig, sa0->use_esn, sa0->seq_hi);
memcpy (digest, (char *) &sig[0], 12);
if (PREDICT_FALSE (is_ipv6))
{
}
else
{
oh0->ip4.ttl = ttl;
oh0->ip4.tos = tos;
oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
}
if (transport_mode)
vlib_buffer_advance (i_b0, -sizeof (ethernet_header_t));;
trace:
if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
{
i_b0->flags |= VLIB_BUFFER_IS_TRACED;
ah_encrypt_trace_t *tr =
vlib_add_trace (vm, node, i_b0, sizeof (*tr));
tr->spi = sa0->spi;
tr->seq = sa0->seq - 1;
tr->integ_alg = sa0->integ_alg;
}
vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
to_next, n_left_to_next, i_bi0,
next0);
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
vlib_node_increment_counter (vm, ah_encrypt_node.index,
AH_ENCRYPT_ERROR_RX_PKTS,
from_frame->n_vectors);
return from_frame->n_vectors;
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ah_encrypt_node) = {
.function = ah_encrypt_node_fn,
.name = "ah-encrypt",
.vector_size = sizeof (u32),
.format_trace = format_ah_encrypt_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(ah_encrypt_error_strings),
.error_strings = ah_encrypt_error_strings,
.n_next_nodes = AH_ENCRYPT_N_NEXT,
.next_nodes = {
#define _(s,n) [AH_ENCRYPT_NEXT_##s] = n,
foreach_ah_encrypt_next
#undef _
},
};
/* *INDENT-ON* */
VLIB_NODE_FUNCTION_MULTIARCH (ah_encrypt_node, ah_encrypt_node_fn)
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/