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/*
* esp_encrypt.c : IPSec ESP 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/udp/udp.h>
#include <vnet/crypto/crypto.h>
#include <vnet/ipsec/ipsec.h>
#include <vnet/ipsec/esp.h>
#define foreach_esp_encrypt_next \
_(DROP, "error-drop") \
_(IP4_LOOKUP, "ip4-lookup") \
_(IP6_LOOKUP, "ip6-lookup") \
_(INTERFACE_OUTPUT, "interface-output")
#define _(v, s) ESP_ENCRYPT_NEXT_##v,
typedef enum
{
foreach_esp_encrypt_next
#undef _
ESP_ENCRYPT_N_NEXT,
} esp_encrypt_next_t;
#define foreach_esp_encrypt_error \
_(RX_PKTS, "ESP pkts received") \
_(SEQ_CYCLED, "sequence number cycled (packet dropped)") \
_(CRYPTO_ENGINE_ERROR, "crypto engine error (packet dropped)") \
_(CHAINED_BUFFER, "chained buffers (packet dropped)") \
_(NO_TRAILER_SPACE, "no trailer space (packet dropped)")
typedef enum
{
#define _(sym,str) ESP_ENCRYPT_ERROR_##sym,
foreach_esp_encrypt_error
#undef _
ESP_ENCRYPT_N_ERROR,
} esp_encrypt_error_t;
static char *esp_encrypt_error_strings[] = {
#define _(sym,string) string,
foreach_esp_encrypt_error
#undef _
};
typedef struct
{
u32 sa_index;
u32 spi;
u32 seq;
u8 udp_encap;
ipsec_crypto_alg_t crypto_alg;
ipsec_integ_alg_t integ_alg;
} esp_encrypt_trace_t;
/* packet trace format function */
static u8 *
format_esp_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 *);
esp_encrypt_trace_t *t = va_arg (*args, esp_encrypt_trace_t *);
s =
format (s,
"esp: sa-index %d spi %u (0x%08x) seq %u crypto %U integrity %U%s",
t->sa_index, t->spi, t->spi, t->seq, format_ipsec_crypto_alg,
t->crypto_alg, format_ipsec_integ_alg, t->integ_alg,
t->udp_encap ? " udp-encap-enabled" : "");
return s;
}
/* pad packet in input buffer */
static_always_inline u8 *
esp_add_footer_and_icv (vlib_buffer_t * b, u8 block_size, u8 icv_sz)
{
static const u8 pad_data[ESP_MAX_BLOCK_SIZE] = {
0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x00, 0x00,
};
u16 min_length = b->current_length + sizeof (esp_footer_t);
u16 new_length = round_pow2 (min_length, block_size);
u8 pad_bytes = new_length - min_length;
esp_footer_t *f = (esp_footer_t *) (vlib_buffer_get_current (b) +
new_length - sizeof (esp_footer_t));
if (pad_bytes)
clib_memcpy_fast ((u8 *) f - pad_bytes, pad_data, ESP_MAX_BLOCK_SIZE);
f->pad_length = pad_bytes;
b->current_length = new_length + icv_sz;
return &f->next_header;
}
static_always_inline void
esp_update_ip4_hdr (ip4_header_t * ip4, u16 len, int is_transport, int is_udp)
{
ip_csum_t sum;
u16 old_len;
len = clib_net_to_host_u16 (len);
old_len = ip4->length;
if (is_transport)
{
u8 prot = is_udp ? IP_PROTOCOL_UDP : IP_PROTOCOL_IPSEC_ESP;
sum = ip_csum_update (ip4->checksum, ip4->protocol,
prot, ip4_header_t, protocol);
ip4->protocol = prot;
sum = ip_csum_update (sum, old_len, len, ip4_header_t, length);
}
else
sum = ip_csum_update (ip4->checksum, old_len, len, ip4_header_t, length);
ip4->length = len;
ip4->checksum = ip_csum_fold (sum);
}
static_always_inline void
esp_fill_udp_hdr (ipsec_sa_t * sa, udp_header_t * udp, u16 len)
{
clib_memcpy_fast (udp, &sa->udp_hdr, sizeof (udp_header_t));
udp->length = clib_net_to_host_u16 (len);
}
static_always_inline u8
ext_hdr_is_pre_esp (u8 nexthdr)
{
#ifdef CLIB_HAVE_VEC128
static const u8x16 ext_hdr_types = {
IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS,
IP_PROTOCOL_IPV6_ROUTE,
IP_PROTOCOL_IPV6_FRAGMENTATION,
};
return !u8x16_is_all_zero (ext_hdr_types == u8x16_splat (nexthdr));
#else
return ((nexthdr ^ IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS) |
(nexthdr ^ IP_PROTOCOL_IPV6_ROUTE) |
(nexthdr ^ IP_PROTOCOL_IPV6_FRAGMENTATION) != 0);
#endif
}
static_always_inline u8
esp_get_ip6_hdr_len (ip6_header_t * ip6)
{
/* this code assumes that HbH, route and frag headers will be before
others, if that is not the case, they will end up encrypted */
u8 len = sizeof (ip6_header_t);
ip6_ext_header_t *p;
/* if next packet doesn't have ext header */
if (ext_hdr_is_pre_esp (ip6->protocol) == 0)
return len;
p = (void *) (ip6 + 1);
len += ip6_ext_header_len (p);
while (ext_hdr_is_pre_esp (p->next_hdr))
{
len += ip6_ext_header_len (p);
p = ip6_ext_next_header (p);
}
return len;
}
static_always_inline int
esp_trailer_icv_overflow (vlib_node_runtime_t * node, vlib_buffer_t * b,
u16 * next, u16 buffer_data_size)
{
if (b->current_data + b->current_length <= buffer_data_size)
return 0;
b->current_length -= buffer_data_size - b->current_data;
b->error = node->errors[ESP_ENCRYPT_ERROR_NO_TRAILER_SPACE];
next[0] = ESP_ENCRYPT_NEXT_DROP;
return 1;
}
static_always_inline void
esp_process_ops (vlib_main_t * vm, vlib_node_runtime_t * node,
vnet_crypto_op_t * ops, vlib_buffer_t * b[], u16 * nexts)
{
u32 n_fail, n_ops = vec_len (ops);
vnet_crypto_op_t *op = ops;
if (n_ops == 0)
return;
n_fail = n_ops - vnet_crypto_process_ops (vm, op, n_ops);
while (n_fail)
{
ASSERT (op - ops < n_ops);
if (op->status != VNET_CRYPTO_OP_STATUS_COMPLETED)
{
u32 bi = op->user_data;
b[bi]->error = node->errors[ESP_ENCRYPT_ERROR_CRYPTO_ENGINE_ERROR];
nexts[bi] = ESP_ENCRYPT_NEXT_DROP;
n_fail--;
}
op++;
}
}
typedef struct
{
u32 salt;
u64 iv;
} __clib_packed esp_gcm_nonce_t;
STATIC_ASSERT_SIZEOF (esp_gcm_nonce_t, 12);
always_inline uword
esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
vlib_frame_t * frame, int is_ip6, int is_tun)
{
ipsec_main_t *im = &ipsec_main;
ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, vm->thread_index);
u32 *from = vlib_frame_vector_args (frame);
u32 n_left = frame->n_vectors;
vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
esp_gcm_nonce_t nonces[VLIB_FRAME_SIZE], *nonce = nonces;
u32 thread_index = vm->thread_index;
u16 buffer_data_size = vlib_buffer_get_default_data_size (vm);
u32 current_sa_index = ~0, current_sa_packets = 0;
u32 current_sa_bytes = 0, spi = 0;
u8 block_sz = 0, iv_sz = 0, icv_sz = 0;
ipsec_sa_t *sa0 = 0;
vlib_get_buffers (vm, from, b, n_left);
vec_reset_length (ptd->crypto_ops);
vec_reset_length (ptd->integ_ops);
while (n_left > 0)
{
u32 sa_index0;
dpo_id_t *dpo;
esp_header_t *esp;
u8 *payload, *next_hdr_ptr;
u16 payload_len;
u32 hdr_len;
if (n_left > 2)
{
u8 *p;
vlib_prefetch_buffer_header (b[2], LOAD);
p = vlib_buffer_get_current (b[1]);
CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD);
p -= CLIB_CACHE_LINE_BYTES;
CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD);
}
if (is_tun)
{
/* we are on a ipsec tunnel's feature arc */
u32 next0;
sa_index0 = *(u32 *) vnet_feature_next_with_data (&next0, b[0],
sizeof
(sa_index0));
next[0] = next0;
}
else
sa_index0 = vnet_buffer (b[0])->ipsec.sad_index;
if (sa_index0 != current_sa_index)
{
if (current_sa_packets)
vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
current_sa_index,
current_sa_packets,
current_sa_bytes);
current_sa_packets = current_sa_bytes = 0;
sa0 = pool_elt_at_index (im->sad, sa_index0);
current_sa_index = sa_index0;
spi = clib_net_to_host_u32 (sa0->spi);
block_sz = sa0->crypto_block_size;
icv_sz = sa0->integ_icv_size;
iv_sz = sa0->crypto_iv_size;
}
if (vlib_buffer_chain_linearize (vm, b[0]) != 1)
{
b[0]->error = node->errors[ESP_ENCRYPT_ERROR_CHAINED_BUFFER];
next[0] = ESP_ENCRYPT_NEXT_DROP;
goto trace;
}
if (PREDICT_FALSE (esp_seq_advance (sa0)))
{
b[0]->error = node->errors[ESP_ENCRYPT_ERROR_SEQ_CYCLED];
next[0] = ESP_ENCRYPT_NEXT_DROP;
goto trace;
}
/* space for IV */
hdr_len = iv_sz;
if (ipsec_sa_is_set_IS_TUNNEL (sa0))
{
payload = vlib_buffer_get_current (b[0]);
next_hdr_ptr = esp_add_footer_and_icv (b[0], block_sz, icv_sz);
payload_len = b[0]->current_length;
if (esp_trailer_icv_overflow (node, b[0], next, buffer_data_size))
goto trace;
/* ESP header */
hdr_len += sizeof (*esp);
esp = (esp_header_t *) (payload - hdr_len);
/* optional UDP header */
if (ipsec_sa_is_set_UDP_ENCAP (sa0))
{
hdr_len += sizeof (udp_header_t);
esp_fill_udp_hdr (sa0, (udp_header_t *) (payload - hdr_len),
payload_len + hdr_len);
}
/* IP header */
if (ipsec_sa_is_set_IS_TUNNEL_V6 (sa0))
{
ip6_header_t *ip6;
u16 len = sizeof (ip6_header_t);
hdr_len += len;
ip6 = (ip6_header_t *) (payload - hdr_len);
clib_memcpy_fast (ip6, &sa0->ip6_hdr, len);
*next_hdr_ptr = (is_ip6 ?
IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP);
len = payload_len + hdr_len - len;
ip6->payload_length = clib_net_to_host_u16 (len);
}
else
{
ip4_header_t *ip4;
u16 len = sizeof (ip4_header_t);
hdr_len += len;
ip4 = (ip4_header_t *) (payload - hdr_len);
clib_memcpy_fast (ip4, &sa0->ip4_hdr, len);
*next_hdr_ptr = (is_ip6 ?
IP_PROTOCOL_IPV6 : IP_PROTOCOL_IP_IN_IP);
len = payload_len + hdr_len;
esp_update_ip4_hdr (ip4, len, /* is_transport */ 0, 0);
}
dpo = &sa0->dpo;
if (!is_tun)
{
next[0] = dpo->dpoi_next_node;
vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
}
}
else /* transport mode */
{
u8 *l2_hdr, l2_len, *ip_hdr, ip_len;
udp_header_t *udp = 0;
u8 *old_ip_hdr = vlib_buffer_get_current (b[0]);
ip_len = is_ip6 ?
esp_get_ip6_hdr_len ((ip6_header_t *) old_ip_hdr) :
ip4_header_bytes ((ip4_header_t *) old_ip_hdr);
vlib_buffer_advance (b[0], ip_len);
payload = vlib_buffer_get_current (b[0]);
next_hdr_ptr = esp_add_footer_and_icv (b[0], block_sz, icv_sz);
payload_len = b[0]->current_length;
if (esp_trailer_icv_overflow (node, b[0], next, buffer_data_size))
goto trace;
/* ESP header */
hdr_len += sizeof (*esp);
esp = (esp_header_t *) (payload - hdr_len);
/* optional UDP header */
if (ipsec_sa_is_set_UDP_ENCAP (sa0))
{
hdr_len += sizeof (udp_header_t);
udp = (udp_header_t *) (payload - hdr_len);
}
/* IP header */
hdr_len += ip_len;
ip_hdr = payload - hdr_len;
/* L2 header */
if (!is_tun)
{
l2_len = vnet_buffer (b[0])->ip.save_rewrite_length;
hdr_len += l2_len;
l2_hdr = payload - hdr_len;
/* copy l2 and ip header */
clib_memcpy_le32 (l2_hdr, old_ip_hdr - l2_len, l2_len);
}
else
l2_len = 0;
clib_memcpy_le64 (ip_hdr, old_ip_hdr, ip_len);
if (is_ip6)
{
ip6_header_t *ip6 = (ip6_header_t *) (ip_hdr);
*next_hdr_ptr = ip6->protocol;
ip6->protocol = IP_PROTOCOL_IPSEC_ESP;
ip6->payload_length =
clib_host_to_net_u16 (payload_len + hdr_len - l2_len -
ip_len);
}
else
{
u16 len;
ip4_header_t *ip4 = (ip4_header_t *) (ip_hdr);
*next_hdr_ptr = ip4->protocol;
len = payload_len + hdr_len - l2_len;
if (udp)
{
esp_update_ip4_hdr (ip4, len, /* is_transport */ 1, 1);
esp_fill_udp_hdr (sa0, udp, len - ip_len);
}
else
esp_update_ip4_hdr (ip4, len, /* is_transport */ 1, 0);
}
if (!is_tun)
next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
}
esp->spi = spi;
esp->seq = clib_net_to_host_u32 (sa0->seq);
if (sa0->crypto_enc_op_id)
{
vnet_crypto_op_t *op;
vec_add2_aligned (ptd->crypto_ops, op, 1, CLIB_CACHE_LINE_BYTES);
vnet_crypto_op_init (op, sa0->crypto_enc_op_id);
op->src = op->dst = payload;
op->key_index = sa0->crypto_key_index;
op->len = payload_len - icv_sz;
op->user_data = b - bufs;
if (ipsec_sa_is_set_IS_AEAD (sa0))
{
/*
* construct the AAD in a scratch space in front
* of the IP header.
*/
op->aad = payload - hdr_len - sizeof (esp_aead_t);
esp_aad_fill (op, esp, sa0);
op->tag = payload + op->len;
op->tag_len = 16;
u64 *iv = (u64 *) (payload - iv_sz);
nonce->salt = sa0->salt;
nonce->iv = *iv = clib_host_to_net_u64 (sa0->gcm_iv_counter++);
op->iv = (u8 *) nonce;
nonce++;
}
else
{
op->iv = payload - iv_sz;
op->flags = VNET_CRYPTO_OP_FLAG_INIT_IV;
}
}
if (sa0->integ_op_id)
{
vnet_crypto_op_t *op;
vec_add2_aligned (ptd->integ_ops, op, 1, CLIB_CACHE_LINE_BYTES);
vnet_crypto_op_init (op, sa0->integ_op_id);
op->src = payload - iv_sz - sizeof (esp_header_t);
op->digest = payload + payload_len - icv_sz;
op->key_index = sa0->integ_key_index;
op->digest_len = icv_sz;
op->len = payload_len - icv_sz + iv_sz + sizeof (esp_header_t);
op->user_data = b - bufs;
if (ipsec_sa_is_set_USE_ESN (sa0))
{
u32 seq_hi = clib_net_to_host_u32 (sa0->seq_hi);
clib_memcpy_fast (op->digest, &seq_hi, sizeof (seq_hi));
op->len += sizeof (seq_hi);
}
}
vlib_buffer_advance (b[0], 0LL - hdr_len);
current_sa_packets += 1;
current_sa_bytes += payload_len;
trace:
if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
{
esp_encrypt_trace_t *tr = vlib_add_trace (vm, node, b[0],
sizeof (*tr));
tr->sa_index = sa_index0;
tr->spi = sa0->spi;
tr->seq = sa0->seq - 1;
tr->udp_encap = ipsec_sa_is_set_UDP_ENCAP (sa0);
tr->crypto_alg = sa0->crypto_alg;
tr->integ_alg = sa0->integ_alg;
}
/* next */
n_left -= 1;
next += 1;
b += 1;
}
vlib_increment_combined_counter (&ipsec_sa_counters, thread_index,
current_sa_index, current_sa_packets,
current_sa_bytes);
esp_process_ops (vm, node, ptd->crypto_ops, bufs, nexts);
esp_process_ops (vm, node, ptd->integ_ops, bufs, nexts);
vlib_node_increment_counter (vm, node->node_index,
ESP_ENCRYPT_ERROR_RX_PKTS, frame->n_vectors);
vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
return frame->n_vectors;
}
VLIB_NODE_FN (esp4_encrypt_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * from_frame)
{
return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ , 0);
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (esp4_encrypt_node) = {
.name = "esp4-encrypt",
.vector_size = sizeof (u32),
.format_trace = format_esp_encrypt_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
.error_strings = esp_encrypt_error_strings,
.n_next_nodes = ESP_ENCRYPT_N_NEXT,
.next_nodes = {
#define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
foreach_esp_encrypt_next
#undef _
},
};
/* *INDENT-ON* */
VLIB_NODE_FN (esp6_encrypt_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * from_frame)
{
return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ , 0);
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (esp6_encrypt_node) = {
.name = "esp6-encrypt",
.vector_size = sizeof (u32),
.format_trace = format_esp_encrypt_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
.error_strings = esp_encrypt_error_strings,
.n_next_nodes = ESP_ENCRYPT_N_NEXT,
.next_nodes = {
#define _(s,n) [ESP_ENCRYPT_NEXT_##s] = n,
foreach_esp_encrypt_next
#undef _
},
};
/* *INDENT-ON* */
VLIB_NODE_FN (esp4_encrypt_tun_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * from_frame)
{
return esp_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ , 1);
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (esp4_encrypt_tun_node) = {
.name = "esp4-encrypt-tun",
.vector_size = sizeof (u32),
.format_trace = format_esp_encrypt_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
.error_strings = esp_encrypt_error_strings,
.n_next_nodes = 1,
.next_nodes = {
[ESP_ENCRYPT_NEXT_DROP] = "ip4-drop",
},
};
VNET_FEATURE_INIT (esp4_encrypt_tun_feat_node, static) =
{
.arc_name = "ip4-output",
.node_name = "esp4-encrypt-tun",
.runs_before = VNET_FEATURES ("adj-midchain-tx"),
};
VNET_FEATURE_INIT (esp4_ethernet_encrypt_tun_feat_node, static) =
{
.arc_name = "ethernet-output",
.node_name = "esp4-encrypt-tun",
.runs_before = VNET_FEATURES ("adj-midchain-tx", "adj-midchain-tx-no-count"),
};
/* *INDENT-ON* */
VLIB_NODE_FN (esp6_encrypt_tun_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * from_frame)
{
return esp_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ , 1);
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (esp6_encrypt_tun_node) = {
.name = "esp6-encrypt-tun",
.vector_size = sizeof (u32),
.format_trace = format_esp_encrypt_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN(esp_encrypt_error_strings),
.error_strings = esp_encrypt_error_strings,
.n_next_nodes = 1,
.next_nodes = {
[ESP_ENCRYPT_NEXT_DROP] = "ip6-drop",
},
};
VNET_FEATURE_INIT (esp6_encrypt_tun_feat_node, static) =
{
.arc_name = "ip6-output",
.node_name = "esp6-encrypt-tun",
.runs_before = VNET_FEATURES ("adj-midchain-tx"),
};
/* *INDENT-ON* */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/