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

 /*
  * 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 _
 };

 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;
 }

 always_inline uword
 ah_encrypt_inline (vlib_main_t * vm,
 		   vlib_node_runtime_t * node, vlib_frame_t * from_frame,
 		   int is_ip6)
 {
   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 ip_hdr_size;
 	  u8 next_hdr_type;
 	  u8 tos = 0;
 	  u8 ttl = 0;
 	  u8 hop_limit = 0;
 	  u32 ip_version_traffic_class_and_flow_label = 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);
 	      if (is_ip6)
 		vlib_node_increment_counter (vm, ah6_encrypt_node.index,
 					     AH_ENCRYPT_ERROR_SEQ_CYCLED, 1);
 	      else
 		vlib_node_increment_counter (vm, ah4_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;

 	  if (PREDICT_TRUE (sa0->is_tunnel))
 	    {
 	      if (is_ip6)
 		adv = -sizeof (ip6_and_ah_header_t);
 	      else
 		adv = -sizeof (ip4_and_ah_header_t);
 	    }
 	  else
 	    {
 	      adv = -sizeof (ah_header_t);
 	    }

 	  icv_size =
 	    em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
 	  const u8 padding_len = ah_calc_icv_padding_len (icv_size, is_ip6);
 	  adv -= padding_len;
 	  /* 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);

 	  if (is_ip6)
 	    {
 	      ih6_0 = (ip6_and_ah_header_t *) ih0;
 	      ip_hdr_size = sizeof (ip6_header_t);
 	      oh6_0 = vlib_buffer_get_current (i_b0);

 	      hop_limit = ih6_0->ip6.hop_limit;
 	      ip_version_traffic_class_and_flow_label =
 		ih6_0->ip6.ip_version_traffic_class_and_flow_label;
 	      if (PREDICT_TRUE (sa0->is_tunnel))
 		{
 		  next_hdr_type = IP_PROTOCOL_IPV6;
 		}
 	      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 = 0;
 	      oh6_0->ip6.ip_version_traffic_class_and_flow_label = 0x60;
 	      oh6_0->ah.reserved = 0;
 	      oh6_0->ah.nexthdr = next_hdr_type;
 	      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));
 	      oh6_0->ah.hdrlen =
 		(sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
 	    }
 	  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 =
 		(sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
 	    }


 	  if (PREDICT_TRUE (!is_ip6 && 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_ip6 && 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;
 	    }

 	  u8 sig[64];
 	  memset (sig, 0, sizeof (sig));
 	  u8 *digest =
 	    vlib_buffer_get_current (i_b0) + ip_hdr_size +
 	    sizeof (ah_header_t);
 	  memset (digest, 0, icv_size);

 	  unsigned size = hmac_calc (sa0->integ_alg, sa0->integ_key,
 				     sa0->integ_key_len,
 				     vlib_buffer_get_current (i_b0),
 				     i_b0->current_length, sig, sa0->use_esn,
 				     sa0->seq_hi);

 	  memcpy (digest, sig, size);
 	  if (is_ip6)
 	    {
 	      oh6_0->ip6.hop_limit = hop_limit;
 	      oh6_0->ip6.ip_version_traffic_class_and_flow_label =
 		ip_version_traffic_class_and_flow_label;
 	    }
 	  else
 	    {
 	      oh0->ip4.ttl = ttl;
 	      oh0->ip4.tos = tos;
 	      oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
 	    }

 	  if (!sa0->is_tunnel)
 	    {
 	      next0 = AH_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 	      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);
     }
   if (is_ip6)
     vlib_node_increment_counter (vm, ah6_encrypt_node.index,
 				 AH_ENCRYPT_ERROR_RX_PKTS,
 				 from_frame->n_vectors);
   else
     vlib_node_increment_counter (vm, ah4_encrypt_node.index,
 				 AH_ENCRYPT_ERROR_RX_PKTS,
 				 from_frame->n_vectors);

   return from_frame->n_vectors;
 }

 static uword
 ah4_encrypt_node_fn (vlib_main_t * vm,
 		     vlib_node_runtime_t * node, vlib_frame_t * from_frame)
 {
   return ah_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ah4_encrypt_node) = {
   .function = ah4_encrypt_node_fn,
   .name = "ah4-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 (ah4_encrypt_node, ah4_encrypt_node_fn);

 static uword
 ah6_encrypt_node_fn (vlib_main_t * vm,
 		     vlib_node_runtime_t * node, vlib_frame_t * from_frame)
 {
   return ah_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ah6_encrypt_node) = {
   .function = ah6_encrypt_node_fn,
   .name = "ah6-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 (ah6_encrypt_node, ah6_encrypt_node_fn);
 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* 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 _
	};

	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;
	}

	always_inline uword
	ah_encrypt_inline (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * from_frame,
	int is_ip6)
	{
	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 ip_hdr_size;
	u8 next_hdr_type;
	u8 tos = 0;
	u8 ttl = 0;
	u8 hop_limit = 0;
	u32 ip_version_traffic_class_and_flow_label = 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);
	if (is_ip6)
	vlib_node_increment_counter (vm, ah6_encrypt_node.index,
	AH_ENCRYPT_ERROR_SEQ_CYCLED, 1);
	else
	vlib_node_increment_counter (vm, ah4_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;

	if (PREDICT_TRUE (sa0->is_tunnel))
	{
	if (is_ip6)
	adv = -sizeof (ip6_and_ah_header_t);
	else
	adv = -sizeof (ip4_and_ah_header_t);
	}
	else
	{
	adv = -sizeof (ah_header_t);
	}

	icv_size =
	em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
	const u8 padding_len = ah_calc_icv_padding_len (icv_size, is_ip6);
	adv -= padding_len;
	/* 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);

	if (is_ip6)
	{
	ih6_0 = (ip6_and_ah_header_t *) ih0;
	ip_hdr_size = sizeof (ip6_header_t);
	oh6_0 = vlib_buffer_get_current (i_b0);

	hop_limit = ih6_0->ip6.hop_limit;
	ip_version_traffic_class_and_flow_label =
	ih6_0->ip6.ip_version_traffic_class_and_flow_label;
	if (PREDICT_TRUE (sa0->is_tunnel))
	{
	next_hdr_type = IP_PROTOCOL_IPV6;
	}
	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 = 0;
	oh6_0->ip6.ip_version_traffic_class_and_flow_label = 0x60;
	oh6_0->ah.reserved = 0;
	oh6_0->ah.nexthdr = next_hdr_type;
	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));
	oh6_0->ah.hdrlen =
	(sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
	}
	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 =
	(sizeof (ah_header_t) + icv_size + padding_len) / 4 - 2;
	}


	if (PREDICT_TRUE (!is_ip6 && 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_ip6 && 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;
	}

	u8 sig[64];
	memset (sig, 0, sizeof (sig));
	u8 *digest =
	vlib_buffer_get_current (i_b0) + ip_hdr_size +
	sizeof (ah_header_t);
	memset (digest, 0, icv_size);

	unsigned size = hmac_calc (sa0->integ_alg, sa0->integ_key,
	sa0->integ_key_len,
	vlib_buffer_get_current (i_b0),
	i_b0->current_length, sig, sa0->use_esn,
	sa0->seq_hi);

	memcpy (digest, sig, size);
	if (is_ip6)
	{
	oh6_0->ip6.hop_limit = hop_limit;
	oh6_0->ip6.ip_version_traffic_class_and_flow_label =
	ip_version_traffic_class_and_flow_label;
	}
	else
	{
	oh0->ip4.ttl = ttl;
	oh0->ip4.tos = tos;
	oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
	}

	if (!sa0->is_tunnel)
	{
	next0 = AH_ENCRYPT_NEXT_INTERFACE_OUTPUT;
	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);
	}
	if (is_ip6)
	vlib_node_increment_counter (vm, ah6_encrypt_node.index,
	AH_ENCRYPT_ERROR_RX_PKTS,
	from_frame->n_vectors);
	else
	vlib_node_increment_counter (vm, ah4_encrypt_node.index,
	AH_ENCRYPT_ERROR_RX_PKTS,
	from_frame->n_vectors);

	return from_frame->n_vectors;
	}

	static uword
	ah4_encrypt_node_fn (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * from_frame)
	{
	return ah_encrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (ah4_encrypt_node) = {
	.function = ah4_encrypt_node_fn,
	.name = "ah4-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 (ah4_encrypt_node, ah4_encrypt_node_fn);

	static uword
	ah6_encrypt_node_fn (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * from_frame)
	{
	return ah_encrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (ah6_encrypt_node) = {
	.function = ah6_encrypt_node_fn,
	.name = "ah6-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 (ah6_encrypt_node, ah6_encrypt_node_fn);
	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/