src/vnet/ipsec/esp_encrypt.c - fdio/vpp - Gitiles

 /*
  * 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/ipsec/ipsec.h>
 #include <vnet/ipsec/esp.h>

 esp_main_t esp_main;

 #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")                    \
  _(NO_BUFFER, "No buffer (packet dropped)")         \
  _(DECRYPTION_FAILED, "ESP encryption failed")      \
  _(SEQ_CYCLED, "sequence number cycled")


 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 _
 };

 vlib_node_registration_t esp_encrypt_node;

 typedef struct
 {
   u32 spi;
   u32 seq;
   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: spi %u seq %u crypto %U integrity %U",
 	      t->spi, t->seq,
 	      format_ipsec_crypto_alg, t->crypto_alg,
 	      format_ipsec_integ_alg, t->integ_alg);
   return s;
 }

 always_inline void
 esp_encrypt_aes_cbc (ipsec_crypto_alg_t alg,
 		     u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
 {
   esp_main_t *em = &esp_main;
   u32 thread_index = vlib_get_thread_index ();
   EVP_CIPHER_CTX *ctx = &(em->per_thread_data[thread_index].encrypt_ctx);
   const EVP_CIPHER *cipher = NULL;
   int out_len;

   ASSERT (alg < IPSEC_CRYPTO_N_ALG);

   if (PREDICT_FALSE (em->esp_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
     return;

   if (PREDICT_FALSE
       (alg != em->per_thread_data[thread_index].last_encrypt_alg))
     {
       cipher = em->esp_crypto_algs[alg].type;
       em->per_thread_data[thread_index].last_encrypt_alg = alg;
     }

   EVP_EncryptInit_ex (ctx, cipher, NULL, key, iv);

   EVP_EncryptUpdate (ctx, out, &out_len, in, in_len);
   EVP_EncryptFinal_ex (ctx, out + out_len, &out_len);
 }

 static uword
 esp_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;
   from = vlib_frame_vector_args (from_frame);
   n_left_from = from_frame->n_vectors;
   ipsec_main_t *im = &ipsec_main;
   u32 *recycle = 0;
   u32 thread_index = vlib_get_thread_index ();

   ipsec_alloc_empty_buffers (vm, im);

   u32 *empty_buffers = im->empty_buffers[thread_index];

   if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
     {
       vlib_node_increment_counter (vm, esp_encrypt_node.index,
 				   ESP_ENCRYPT_ERROR_NO_BUFFER, n_left_from);
       clib_warning ("no enough empty buffers. discarding frame");
       goto free_buffers_and_exit;
     }

   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, o_bi0, next0;
 	  vlib_buffer_t *i_b0, *o_b0 = 0;
 	  u32 sa_index0;
 	  ipsec_sa_t *sa0;
 	  ip4_and_esp_header_t *ih0, *oh0 = 0;
 	  ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
 	  uword last_empty_buffer;
 	  esp_header_t *o_esp0;
 	  esp_footer_t *f0;
 	  u8 is_ipv6;
 	  u8 ip_hdr_size;
 	  u8 next_hdr_type;
 	  u32 ip_proto = 0;
 	  u8 transport_mode = 0;

 	  i_bi0 = from[0];
 	  from += 1;
 	  n_left_from -= 1;
 	  n_left_to_next -= 1;

 	  next0 = ESP_ENCRYPT_NEXT_DROP;

 	  i_b0 = vlib_get_buffer (vm, i_bi0);
 	  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, esp_encrypt_node.index,
 					   ESP_ENCRYPT_ERROR_SEQ_CYCLED, 1);
 	      //TODO: rekey SA
 	      o_bi0 = i_bi0;
 	      to_next[0] = o_bi0;
 	      to_next += 1;
 	      goto trace;
 	    }

 	  sa0->total_data_size += i_b0->current_length;

 	  /* grab free buffer */
 	  last_empty_buffer = vec_len (empty_buffers) - 1;
 	  o_bi0 = empty_buffers[last_empty_buffer];
 	  o_b0 = vlib_get_buffer (vm, o_bi0);
 	  o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 	  o_b0->current_data = sizeof (ethernet_header_t);
 	  ih0 = vlib_buffer_get_current (i_b0);
 	  vlib_prefetch_buffer_with_index (vm,
 					   empty_buffers[last_empty_buffer -
 							 1], STORE);
 	  _vec_len (empty_buffers) = last_empty_buffer;
 	  to_next[0] = o_bi0;
 	  to_next += 1;

 	  /* add old buffer to the recycle list */
 	  vec_add1 (recycle, i_bi0);

 	  /* is ipv6 */
 	  if (PREDICT_FALSE
 	      ((ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60))
 	    {
 	      is_ipv6 = 1;
 	      ih6_0 = vlib_buffer_get_current (i_b0);
 	      ip_hdr_size = sizeof (ip6_header_t);
 	      next_hdr_type = IP_PROTOCOL_IPV6;
 	      oh6_0 = vlib_buffer_get_current (o_b0);
 	      o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip6_header_t);

 	      oh6_0->ip6.ip_version_traffic_class_and_flow_label =
 		ih6_0->ip6.ip_version_traffic_class_and_flow_label;
 	      oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
 	      oh6_0->ip6.hop_limit = 254;
 	      oh6_0->ip6.src_address.as_u64[0] =
 		ih6_0->ip6.src_address.as_u64[0];
 	      oh6_0->ip6.src_address.as_u64[1] =
 		ih6_0->ip6.src_address.as_u64[1];
 	      oh6_0->ip6.dst_address.as_u64[0] =
 		ih6_0->ip6.dst_address.as_u64[0];
 	      oh6_0->ip6.dst_address.as_u64[1] =
 		ih6_0->ip6.dst_address.as_u64[1];
 	      oh6_0->esp.spi = clib_net_to_host_u32 (sa0->spi);
 	      oh6_0->esp.seq = clib_net_to_host_u32 (sa0->seq);
 	      ip_proto = ih6_0->ip6.protocol;

 	      next0 = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
 	    }
 	  else
 	    {
 	      is_ipv6 = 0;
 	      ip_hdr_size = sizeof (ip4_header_t);
 	      next_hdr_type = IP_PROTOCOL_IP_IN_IP;
 	      oh0 = vlib_buffer_get_current (o_b0);
 	      o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip4_header_t);

 	      oh0->ip4.ip_version_and_header_length = 0x45;
 	      oh0->ip4.tos = ih0->ip4.tos;
 	      oh0->ip4.fragment_id = 0;
 	      oh0->ip4.flags_and_fragment_offset = 0;
 	      oh0->ip4.ttl = 254;
 	      oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
 	      oh0->ip4.src_address.as_u32 = ih0->ip4.src_address.as_u32;
 	      oh0->ip4.dst_address.as_u32 = ih0->ip4.dst_address.as_u32;
 	      oh0->esp.spi = clib_net_to_host_u32 (sa0->spi);
 	      oh0->esp.seq = clib_net_to_host_u32 (sa0->seq);
 	      ip_proto = ih0->ip4.protocol;

 	      next0 = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
 	    }

 	  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;

 	      vnet_buffer (o_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];

 	      vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 	    }
 	  else
 	    {
 	      next_hdr_type = ip_proto;
 	      if (vnet_buffer (i_b0)->sw_if_index[VLIB_TX] != ~0)
 		{
 		  transport_mode = 1;
 		  ethernet_header_t *ieh0, *oeh0;
 		  ieh0 =
 		    (ethernet_header_t *) ((u8 *)
 					   vlib_buffer_get_current (i_b0) -
 					   sizeof (ethernet_header_t));
 		  oeh0 = (ethernet_header_t *) o_b0->data;
 		  clib_memcpy (oeh0, ieh0, sizeof (ethernet_header_t));
 		  next0 = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 		  vnet_buffer (o_b0)->sw_if_index[VLIB_TX] =
 		    vnet_buffer (i_b0)->sw_if_index[VLIB_TX];
 		}
 	      vlib_buffer_advance (i_b0, ip_hdr_size);
 	    }

 	  ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);

 	  if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
 	    {

 	      const int BLOCK_SIZE = 16;
 	      const int IV_SIZE = 16;
 	      int blocks = 1 + (i_b0->current_length + 1) / BLOCK_SIZE;

 	      /* pad packet in input buffer */
 	      u8 pad_bytes = BLOCK_SIZE * blocks - 2 - i_b0->current_length;
 	      u8 i;
 	      u8 *padding =
 		vlib_buffer_get_current (i_b0) + i_b0->current_length;
 	      i_b0->current_length = BLOCK_SIZE * blocks;
 	      for (i = 0; i < pad_bytes; ++i)
 		{
 		  padding[i] = i + 1;
 		}
 	      f0 = vlib_buffer_get_current (i_b0) + i_b0->current_length - 2;
 	      f0->pad_length = pad_bytes;
 	      f0->next_header = next_hdr_type;

 	      o_b0->current_length = ip_hdr_size + sizeof (esp_header_t) +
 		BLOCK_SIZE * blocks + IV_SIZE;

 	      vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
 		vnet_buffer (i_b0)->sw_if_index[VLIB_RX];

 	      u8 iv[16];
 	      RAND_bytes (iv, sizeof (iv));

 	      clib_memcpy ((u8 *) vlib_buffer_get_current (o_b0) +
 			   ip_hdr_size + sizeof (esp_header_t), iv, 16);

 	      esp_encrypt_aes_cbc (sa0->crypto_alg,
 				   (u8 *) vlib_buffer_get_current (i_b0),
 				   (u8 *) vlib_buffer_get_current (o_b0) +
 				   ip_hdr_size + sizeof (esp_header_t) +
 				   IV_SIZE, BLOCK_SIZE * blocks,
 				   sa0->crypto_key, iv);
 	    }

 	  o_b0->current_length += hmac_calc (sa0->integ_alg, sa0->integ_key,
 					     sa0->integ_key_len,
 					     (u8 *) o_esp0,
 					     o_b0->current_length -
 					     ip_hdr_size,
 					     vlib_buffer_get_current (o_b0) +
 					     o_b0->current_length,
 					     sa0->use_esn, sa0->seq_hi);


 	  if (PREDICT_FALSE (is_ipv6))
 	    {
 	      oh6_0->ip6.payload_length =
 		clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0) -
 				      sizeof (ip6_header_t));
 	    }
 	  else
 	    {
 	      oh0->ip4.length =
 		clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0));
 	      oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
 	    }

 	  if (transport_mode)
 	    vlib_buffer_reset (o_b0);

 	trace:
 	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      if (o_b0)
 		{
 		  o_b0->flags |= VLIB_BUFFER_IS_TRACED;
 		  o_b0->trace_index = i_b0->trace_index;
 		  esp_encrypt_trace_t *tr =
 		    vlib_add_trace (vm, node, o_b0, sizeof (*tr));
 		  tr->spi = sa0->spi;
 		  tr->seq = sa0->seq - 1;
 		  tr->crypto_alg = sa0->crypto_alg;
 		  tr->integ_alg = sa0->integ_alg;
 		}
 	    }

 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next, o_bi0,
 					   next0);
 	}
       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }
   vlib_node_increment_counter (vm, esp_encrypt_node.index,
 			       ESP_ENCRYPT_ERROR_RX_PKTS,
 			       from_frame->n_vectors);

 free_buffers_and_exit:
   if (recycle)
     vlib_buffer_free (vm, recycle, vec_len (recycle));
   vec_free (recycle);
   return from_frame->n_vectors;
 }


 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (esp_encrypt_node) = {
   .function = esp_encrypt_node_fn,
   .name = "esp-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_FUNCTION_MULTIARCH (esp_encrypt_node, esp_encrypt_node_fn)
 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* 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/ipsec/ipsec.h>
	#include <vnet/ipsec/esp.h>

	esp_main_t esp_main;

	#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") \
	_(NO_BUFFER, "No buffer (packet dropped)") \
	_(DECRYPTION_FAILED, "ESP encryption failed") \
	_(SEQ_CYCLED, "sequence number cycled")


	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 _
	};

	vlib_node_registration_t esp_encrypt_node;

	typedef struct
	{
	u32 spi;
	u32 seq;
	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: spi %u seq %u crypto %U integrity %U",
	t->spi, t->seq,
	format_ipsec_crypto_alg, t->crypto_alg,
	format_ipsec_integ_alg, t->integ_alg);
	return s;
	}

	always_inline void
	esp_encrypt_aes_cbc (ipsec_crypto_alg_t alg,
	u8 * in, u8 * out, size_t in_len, u8 * key, u8 * iv)
	{
	esp_main_t *em = &esp_main;
	u32 thread_index = vlib_get_thread_index ();
	EVP_CIPHER_CTX *ctx = &(em->per_thread_data[thread_index].encrypt_ctx);
	const EVP_CIPHER *cipher = NULL;
	int out_len;

	ASSERT (alg < IPSEC_CRYPTO_N_ALG);

	if (PREDICT_FALSE (em->esp_crypto_algs[alg].type == IPSEC_CRYPTO_ALG_NONE))
	return;

	if (PREDICT_FALSE
	(alg != em->per_thread_data[thread_index].last_encrypt_alg))
	{
	cipher = em->esp_crypto_algs[alg].type;
	em->per_thread_data[thread_index].last_encrypt_alg = alg;
	}

	EVP_EncryptInit_ex (ctx, cipher, NULL, key, iv);

	EVP_EncryptUpdate (ctx, out, &out_len, in, in_len);
	EVP_EncryptFinal_ex (ctx, out + out_len, &out_len);
	}

	static uword
	esp_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;
	from = vlib_frame_vector_args (from_frame);
	n_left_from = from_frame->n_vectors;
	ipsec_main_t *im = &ipsec_main;
	u32 *recycle = 0;
	u32 thread_index = vlib_get_thread_index ();

	ipsec_alloc_empty_buffers (vm, im);

	u32 *empty_buffers = im->empty_buffers[thread_index];

	if (PREDICT_FALSE (vec_len (empty_buffers) < n_left_from))
	{
	vlib_node_increment_counter (vm, esp_encrypt_node.index,
	ESP_ENCRYPT_ERROR_NO_BUFFER, n_left_from);
	clib_warning ("no enough empty buffers. discarding frame");
	goto free_buffers_and_exit;
	}

	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, o_bi0, next0;
	vlib_buffer_t i_b0, o_b0 = 0;
	u32 sa_index0;
	ipsec_sa_t *sa0;
	ip4_and_esp_header_t ih0, oh0 = 0;
	ip6_and_esp_header_t ih6_0, oh6_0 = 0;
	uword last_empty_buffer;
	esp_header_t *o_esp0;
	esp_footer_t *f0;
	u8 is_ipv6;
	u8 ip_hdr_size;
	u8 next_hdr_type;
	u32 ip_proto = 0;
	u8 transport_mode = 0;

	i_bi0 = from[0];
	from += 1;
	n_left_from -= 1;
	n_left_to_next -= 1;

	next0 = ESP_ENCRYPT_NEXT_DROP;

	i_b0 = vlib_get_buffer (vm, i_bi0);
	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, esp_encrypt_node.index,
	ESP_ENCRYPT_ERROR_SEQ_CYCLED, 1);
	//TODO: rekey SA
	o_bi0 = i_bi0;
	to_next[0] = o_bi0;
	to_next += 1;
	goto trace;
	}

	sa0->total_data_size += i_b0->current_length;

	/* grab free buffer */
	last_empty_buffer = vec_len (empty_buffers) - 1;
	o_bi0 = empty_buffers[last_empty_buffer];
	o_b0 = vlib_get_buffer (vm, o_bi0);
	o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
	o_b0->current_data = sizeof (ethernet_header_t);
	ih0 = vlib_buffer_get_current (i_b0);
	vlib_prefetch_buffer_with_index (vm,
	empty_buffers[last_empty_buffer -
	1], STORE);
	_vec_len (empty_buffers) = last_empty_buffer;
	to_next[0] = o_bi0;
	to_next += 1;

	/* add old buffer to the recycle list */
	vec_add1 (recycle, i_bi0);

	/* is ipv6 */
	if (PREDICT_FALSE
	((ih0->ip4.ip_version_and_header_length & 0xF0) == 0x60))
	{
	is_ipv6 = 1;
	ih6_0 = vlib_buffer_get_current (i_b0);
	ip_hdr_size = sizeof (ip6_header_t);
	next_hdr_type = IP_PROTOCOL_IPV6;
	oh6_0 = vlib_buffer_get_current (o_b0);
	o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip6_header_t);

	oh6_0->ip6.ip_version_traffic_class_and_flow_label =
	ih6_0->ip6.ip_version_traffic_class_and_flow_label;
	oh6_0->ip6.protocol = IP_PROTOCOL_IPSEC_ESP;
	oh6_0->ip6.hop_limit = 254;
	oh6_0->ip6.src_address.as_u64[0] =
	ih6_0->ip6.src_address.as_u64[0];
	oh6_0->ip6.src_address.as_u64[1] =
	ih6_0->ip6.src_address.as_u64[1];
	oh6_0->ip6.dst_address.as_u64[0] =
	ih6_0->ip6.dst_address.as_u64[0];
	oh6_0->ip6.dst_address.as_u64[1] =
	ih6_0->ip6.dst_address.as_u64[1];
	oh6_0->esp.spi = clib_net_to_host_u32 (sa0->spi);
	oh6_0->esp.seq = clib_net_to_host_u32 (sa0->seq);
	ip_proto = ih6_0->ip6.protocol;

	next0 = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
	}
	else
	{
	is_ipv6 = 0;
	ip_hdr_size = sizeof (ip4_header_t);
	next_hdr_type = IP_PROTOCOL_IP_IN_IP;
	oh0 = vlib_buffer_get_current (o_b0);
	o_esp0 = vlib_buffer_get_current (o_b0) + sizeof (ip4_header_t);

	oh0->ip4.ip_version_and_header_length = 0x45;
	oh0->ip4.tos = ih0->ip4.tos;
	oh0->ip4.fragment_id = 0;
	oh0->ip4.flags_and_fragment_offset = 0;
	oh0->ip4.ttl = 254;
	oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
	oh0->ip4.src_address.as_u32 = ih0->ip4.src_address.as_u32;
	oh0->ip4.dst_address.as_u32 = ih0->ip4.dst_address.as_u32;
	oh0->esp.spi = clib_net_to_host_u32 (sa0->spi);
	oh0->esp.seq = clib_net_to_host_u32 (sa0->seq);
	ip_proto = ih0->ip4.protocol;

	next0 = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
	}

	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;

	vnet_buffer (o_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];

	vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
	}
	else
	{
	next_hdr_type = ip_proto;
	if (vnet_buffer (i_b0)->sw_if_index[VLIB_TX] != ~0)
	{
	transport_mode = 1;
	ethernet_header_t ieh0, oeh0;
	ieh0 =
	(ethernet_header_t ) ((u8 )
	vlib_buffer_get_current (i_b0) -
	sizeof (ethernet_header_t));
	oeh0 = (ethernet_header_t *) o_b0->data;
	clib_memcpy (oeh0, ieh0, sizeof (ethernet_header_t));
	next0 = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
	vnet_buffer (o_b0)->sw_if_index[VLIB_TX] =
	vnet_buffer (i_b0)->sw_if_index[VLIB_TX];
	}
	vlib_buffer_advance (i_b0, ip_hdr_size);
	}

	ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);

	if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
	{

	const int BLOCK_SIZE = 16;
	const int IV_SIZE = 16;
	int blocks = 1 + (i_b0->current_length + 1) / BLOCK_SIZE;

	/* pad packet in input buffer */
	u8 pad_bytes = BLOCK_SIZE * blocks - 2 - i_b0->current_length;
	u8 i;
	u8 *padding =
	vlib_buffer_get_current (i_b0) + i_b0->current_length;
	i_b0->current_length = BLOCK_SIZE * blocks;
	for (i = 0; i < pad_bytes; ++i)
	{
	padding[i] = i + 1;
	}
	f0 = vlib_buffer_get_current (i_b0) + i_b0->current_length - 2;
	f0->pad_length = pad_bytes;
	f0->next_header = next_hdr_type;

	o_b0->current_length = ip_hdr_size + sizeof (esp_header_t) +
	BLOCK_SIZE * blocks + IV_SIZE;

	vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
	vnet_buffer (i_b0)->sw_if_index[VLIB_RX];

	u8 iv[16];
	RAND_bytes (iv, sizeof (iv));

	clib_memcpy ((u8 *) vlib_buffer_get_current (o_b0) +
	ip_hdr_size + sizeof (esp_header_t), iv, 16);

	esp_encrypt_aes_cbc (sa0->crypto_alg,
	(u8 *) vlib_buffer_get_current (i_b0),
	(u8 *) vlib_buffer_get_current (o_b0) +
	ip_hdr_size + sizeof (esp_header_t) +
	IV_SIZE, BLOCK_SIZE * blocks,
	sa0->crypto_key, iv);
	}

	o_b0->current_length += hmac_calc (sa0->integ_alg, sa0->integ_key,
	sa0->integ_key_len,
	(u8 *) o_esp0,
	o_b0->current_length -
	ip_hdr_size,
	vlib_buffer_get_current (o_b0) +
	o_b0->current_length,
	sa0->use_esn, sa0->seq_hi);


	if (PREDICT_FALSE (is_ipv6))
	{
	oh6_0->ip6.payload_length =
	clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0) -
	sizeof (ip6_header_t));
	}
	else
	{
	oh0->ip4.length =
	clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0));
	oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
	}

	if (transport_mode)
	vlib_buffer_reset (o_b0);

	trace:
	if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
	{
	if (o_b0)
	{
	o_b0->flags \|= VLIB_BUFFER_IS_TRACED;
	o_b0->trace_index = i_b0->trace_index;
	esp_encrypt_trace_t *tr =
	vlib_add_trace (vm, node, o_b0, sizeof (*tr));
	tr->spi = sa0->spi;
	tr->seq = sa0->seq - 1;
	tr->crypto_alg = sa0->crypto_alg;
	tr->integ_alg = sa0->integ_alg;
	}
	}

	vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
	to_next, n_left_to_next, o_bi0,
	next0);
	}
	vlib_put_next_frame (vm, node, next_index, n_left_to_next);
	}
	vlib_node_increment_counter (vm, esp_encrypt_node.index,
	ESP_ENCRYPT_ERROR_RX_PKTS,
	from_frame->n_vectors);

	free_buffers_and_exit:
	if (recycle)
	vlib_buffer_free (vm, recycle, vec_len (recycle));
	vec_free (recycle);
	return from_frame->n_vectors;
	}


	/* INDENT-OFF */
	VLIB_REGISTER_NODE (esp_encrypt_node) = {
	.function = esp_encrypt_node_fn,
	.name = "esp-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_FUNCTION_MULTIARCH (esp_encrypt_node, esp_encrypt_node_fn)
	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/