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

 /*
  * ah_decrypt.c : IPSec AH decrypt 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_decrypt_next \
   _ (DROP, "error-drop")        \
   _ (IP4_INPUT, "ip4-input")    \
   _ (IP6_INPUT, "ip6-input")    \
   _ (IPSEC_GRE_INPUT, "ipsec-gre-input")

 #define _(v, s) AH_DECRYPT_NEXT_##v,
 typedef enum
 {
   foreach_ah_decrypt_next
 #undef _
     AH_DECRYPT_N_NEXT,
 } ah_decrypt_next_t;

 #define foreach_ah_decrypt_error                \
   _ (RX_PKTS, "AH pkts received")               \
   _ (DECRYPTION_FAILED, "AH decryption failed") \
   _ (INTEG_ERROR, "Integrity check failed")     \
   _ (REPLAY, "SA replayed packet")

 typedef enum
 {
 #define _(sym,str) AH_DECRYPT_ERROR_##sym,
   foreach_ah_decrypt_error
 #undef _
     AH_DECRYPT_N_ERROR,
 } ah_decrypt_error_t;

 static char *ah_decrypt_error_strings[] = {
 #define _(sym,string) string,
   foreach_ah_decrypt_error
 #undef _
 };

 typedef struct
 {
   ipsec_integ_alg_t integ_alg;
 } ah_decrypt_trace_t;

 /* packet trace format function */
 static u8 *
 format_ah_decrypt_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_decrypt_trace_t *t = va_arg (*args, ah_decrypt_trace_t *);

   s = format (s, "ah: integrity %U", format_ipsec_integ_alg, t->integ_alg);
   return s;
 }

 always_inline uword
 ah_decrypt_inline (vlib_main_t * vm,
 		   vlib_node_runtime_t * node, vlib_frame_t * from_frame,
 		   int is_ip6)
 {
   u32 n_left_from, *from, next_index, *to_next;
   ipsec_main_t *im = &ipsec_main;
   ipsec_proto_main_t *em = &ipsec_proto_main;
   from = vlib_frame_vector_args (from_frame);
   n_left_from = from_frame->n_vectors;
   int icv_size = 0;

   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;
 	  u32 next0;
 	  vlib_buffer_t *i_b0;
 	  ah_header_t *ah0;
 	  ipsec_sa_t *sa0;
 	  u32 sa_index0 = ~0;
 	  u32 seq;
 	  ip4_header_t *ih4 = 0, *oh4 = 0;
 	  ip6_header_t *ih6 = 0, *oh6 = 0;
 	  u8 ip_hdr_size = 0;
 	  u8 tos = 0;
 	  u8 ttl = 0;
 	  u32 ip_version_traffic_class_and_flow_label = 0;
 	  u8 hop_limit = 0;
 	  u8 nexthdr = 0;
 	  u8 icv_padding_len = 0;


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

 	  next0 = AH_DECRYPT_NEXT_DROP;

 	  i_b0 = vlib_get_buffer (vm, i_bi0);
 	  to_next[0] = i_bi0;
 	  to_next += 1;
 	  ih4 = vlib_buffer_get_current (i_b0);
 	  ih6 = vlib_buffer_get_current (i_b0);
 	  sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
 	  sa0 = pool_elt_at_index (im->sad, sa_index0);

 	  if (is_ip6)
 	    {
 	      ip6_ext_header_t *prev = NULL;
 	      ip6_ext_header_find_t (ih6, prev, ah0, IP_PROTOCOL_IPSEC_AH);
 	      ip_hdr_size = sizeof (ip6_header_t);
 	      ASSERT ((u8 *) ah0 - (u8 *) ih6 == ip_hdr_size);
 	    }
 	  else
 	    {
 	      ip_hdr_size = ip4_header_bytes (ih4);
 	      ah0 = (ah_header_t *) ((u8 *) ih4 + ip_hdr_size);
 	    }

 	  seq = clib_host_to_net_u32 (ah0->seq_no);
 	  /* anti-replay check */
 	  //TODO UT remaining
 	  if (sa0->use_anti_replay)
 	    {
 	      int rv = 0;

 	      if (PREDICT_TRUE (sa0->use_esn))
 		rv = esp_replay_check_esn (sa0, seq);
 	      else
 		rv = esp_replay_check (sa0, seq);

 	      if (PREDICT_FALSE (rv))
 		{
 		  clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
 		  if (is_ip6)
 		    vlib_node_increment_counter (vm,
 						 ah6_decrypt_node.index,
 						 AH_DECRYPT_ERROR_REPLAY, 1);
 		  else
 		    vlib_node_increment_counter (vm,
 						 ah4_decrypt_node.index,
 						 AH_DECRYPT_ERROR_REPLAY, 1);
 		  to_next[0] = i_bi0;
 		  to_next += 1;
 		  goto trace;
 		}
 	    }


 	  sa0->total_data_size += i_b0->current_length;
 	  icv_size =
 	    em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
 	  if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
 	    {
 	      u8 sig[64];
 	      u8 digest[64];
 	      clib_memset (sig, 0, sizeof (sig));
 	      clib_memset (digest, 0, sizeof (digest));
 	      u8 *icv = ah0->auth_data;
 	      memcpy (digest, icv, icv_size);
 	      clib_memset (icv, 0, icv_size);

 	      if (is_ip6)
 		{
 		  ip_version_traffic_class_and_flow_label =
 		    ih6->ip_version_traffic_class_and_flow_label;
 		  hop_limit = ih6->hop_limit;
 		  ih6->ip_version_traffic_class_and_flow_label = 0x60;
 		  ih6->hop_limit = 0;
 		  nexthdr = ah0->nexthdr;
 		  icv_padding_len =
 		    ah_calc_icv_padding_len (icv_size, 1 /* is_ipv6 */ );
 		}
 	      else
 		{
 		  tos = ih4->tos;
 		  ttl = ih4->ttl;
 		  ih4->tos = 0;
 		  ih4->ttl = 0;
 		  ih4->checksum = 0;
 		  ih4->flags_and_fragment_offset = 0;
 		  icv_padding_len =
 		    ah_calc_icv_padding_len (icv_size, 0 /* is_ipv6 */ );
 		}
 	      hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
 			 (u8 *) ih4, i_b0->current_length, sig, sa0->use_esn,
 			 sa0->seq_hi);

 	      if (PREDICT_FALSE (memcmp (digest, sig, icv_size)))
 		{
 		  if (is_ip6)
 		    vlib_node_increment_counter (vm,
 						 ah6_decrypt_node.index,
 						 AH_DECRYPT_ERROR_INTEG_ERROR,
 						 1);
 		  else
 		    vlib_node_increment_counter (vm,
 						 ah4_decrypt_node.index,
 						 AH_DECRYPT_ERROR_INTEG_ERROR,
 						 1);
 		  to_next[0] = i_bi0;
 		  to_next += 1;
 		  goto trace;
 		}

 	      //TODO UT remaining
 	      if (PREDICT_TRUE (sa0->use_anti_replay))
 		{
 		  if (PREDICT_TRUE (sa0->use_esn))
 		    esp_replay_advance_esn (sa0, seq);
 		  else
 		    esp_replay_advance (sa0, seq);
 		}

 	    }

 	  vlib_buffer_advance (i_b0,
 			       ip_hdr_size + sizeof (ah_header_t) + icv_size +
 			       icv_padding_len);
 	  i_b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;

 	  if (PREDICT_TRUE (sa0->is_tunnel))
 	    {			/* tunnel mode */
 	      if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP))
 		next0 = AH_DECRYPT_NEXT_IP4_INPUT;
 	      else if (ah0->nexthdr == IP_PROTOCOL_IPV6)
 		next0 = AH_DECRYPT_NEXT_IP6_INPUT;
 	      else
 		{
 		  clib_warning ("next header: 0x%x", ah0->nexthdr);
 		  if (is_ip6)
 		    vlib_node_increment_counter (vm,
 						 ah6_decrypt_node.index,
 						 AH_DECRYPT_ERROR_DECRYPTION_FAILED,
 						 1);
 		  else
 		    vlib_node_increment_counter (vm,
 						 ah4_decrypt_node.index,
 						 AH_DECRYPT_ERROR_DECRYPTION_FAILED,
 						 1);
 		  goto trace;
 		}
 	    }
 	  else
 	    {			/* transport mode */
 	      if (is_ip6)
 		{
 		  vlib_buffer_advance (i_b0, -sizeof (ip6_header_t));
 		  oh6 = vlib_buffer_get_current (i_b0);
 		  memmove (oh6, ih6, sizeof (ip6_header_t));

 		  next0 = AH_DECRYPT_NEXT_IP6_INPUT;
 		  oh6->protocol = nexthdr;
 		  oh6->hop_limit = hop_limit;
 		  oh6->ip_version_traffic_class_and_flow_label =
 		    ip_version_traffic_class_and_flow_label;
 		  oh6->payload_length =
 		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
 					  (vm, i_b0) - sizeof (ip6_header_t));
 		}
 	      else
 		{
 		  vlib_buffer_advance (i_b0, -sizeof (ip4_header_t));
 		  oh4 = vlib_buffer_get_current (i_b0);
 		  memmove (oh4, ih4, sizeof (ip4_header_t));

 		  next0 = AH_DECRYPT_NEXT_IP4_INPUT;
 		  oh4->ip_version_and_header_length = 0x45;
 		  oh4->fragment_id = 0;
 		  oh4->flags_and_fragment_offset = 0;
 		  oh4->protocol = ah0->nexthdr;
 		  oh4->length =
 		    clib_host_to_net_u16 (vlib_buffer_length_in_chain
 					  (vm, i_b0));
 		  oh4->ttl = ttl;
 		  oh4->tos = tos;
 		  oh4->checksum = ip4_header_checksum (oh4);
 		}
 	    }

 	  /* for IPSec-GRE tunnel next node is ipsec-gre-input */
 	  if (PREDICT_FALSE
 	      ((vnet_buffer (i_b0)->ipsec.flags) &
 	       IPSEC_FLAG_IPSEC_GRE_TUNNEL))
 	    next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT;


 	  vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 	trace:
 	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      i_b0->flags |= VLIB_BUFFER_IS_TRACED;
 	      ah_decrypt_trace_t *tr =
 		vlib_add_trace (vm, node, i_b0, sizeof (*tr));
 	      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_decrypt_node.index,
 				 AH_DECRYPT_ERROR_RX_PKTS,
 				 from_frame->n_vectors);
   else
     vlib_node_increment_counter (vm, ah4_decrypt_node.index,
 				 AH_DECRYPT_ERROR_RX_PKTS,
 				 from_frame->n_vectors);

   return from_frame->n_vectors;
 }

 static uword
 ah4_decrypt_node_fn (vlib_main_t * vm,
 		     vlib_node_runtime_t * node, vlib_frame_t * from_frame)
 {
   return ah_decrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ah4_decrypt_node) = {
   .function = ah4_decrypt_node_fn,
   .name = "ah4-decrypt",
   .vector_size = sizeof (u32),
   .format_trace = format_ah_decrypt_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
   .error_strings = ah_decrypt_error_strings,

   .n_next_nodes = AH_DECRYPT_N_NEXT,
   .next_nodes = {
 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
     foreach_ah_decrypt_next
 #undef _
   },
 };
 /* *INDENT-ON* */

 VLIB_NODE_FUNCTION_MULTIARCH (ah4_decrypt_node, ah4_decrypt_node_fn);

 static uword
 ah6_decrypt_node_fn (vlib_main_t * vm,
 		     vlib_node_runtime_t * node, vlib_frame_t * from_frame)
 {
   return ah_decrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ah6_decrypt_node) = {
   .function = ah6_decrypt_node_fn,
   .name = "ah6-decrypt",
   .vector_size = sizeof (u32),
   .format_trace = format_ah_decrypt_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(ah_decrypt_error_strings),
   .error_strings = ah_decrypt_error_strings,

   .n_next_nodes = AH_DECRYPT_N_NEXT,
   .next_nodes = {
 #define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
     foreach_ah_decrypt_next
 #undef _
   },
 };
 /* *INDENT-ON* */

 VLIB_NODE_FUNCTION_MULTIARCH (ah6_decrypt_node, ah6_decrypt_node_fn);
 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* ah_decrypt.c : IPSec AH decrypt 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_decrypt_next \
	_ (DROP, "error-drop") \
	_ (IP4_INPUT, "ip4-input") \
	_ (IP6_INPUT, "ip6-input") \
	_ (IPSEC_GRE_INPUT, "ipsec-gre-input")

	#define _(v, s) AH_DECRYPT_NEXT_##v,
	typedef enum
	{
	foreach_ah_decrypt_next
	#undef _
	AH_DECRYPT_N_NEXT,
	} ah_decrypt_next_t;

	#define foreach_ah_decrypt_error \
	_ (RX_PKTS, "AH pkts received") \
	_ (DECRYPTION_FAILED, "AH decryption failed") \
	_ (INTEG_ERROR, "Integrity check failed") \
	_ (REPLAY, "SA replayed packet")

	typedef enum
	{
	#define _(sym,str) AH_DECRYPT_ERROR_##sym,
	foreach_ah_decrypt_error
	#undef _
	AH_DECRYPT_N_ERROR,
	} ah_decrypt_error_t;

	static char *ah_decrypt_error_strings[] = {
	#define _(sym,string) string,
	foreach_ah_decrypt_error
	#undef _
	};

	typedef struct
	{
	ipsec_integ_alg_t integ_alg;
	} ah_decrypt_trace_t;

	/* packet trace format function */
	static u8 *
	format_ah_decrypt_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_decrypt_trace_t t = va_arg (args, ah_decrypt_trace_t *);

	s = format (s, "ah: integrity %U", format_ipsec_integ_alg, t->integ_alg);
	return s;
	}

	always_inline uword
	ah_decrypt_inline (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * from_frame,
	int is_ip6)
	{
	u32 n_left_from, from, next_index, to_next;
	ipsec_main_t *im = &ipsec_main;
	ipsec_proto_main_t *em = &ipsec_proto_main;
	from = vlib_frame_vector_args (from_frame);
	n_left_from = from_frame->n_vectors;
	int icv_size = 0;

	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;
	u32 next0;
	vlib_buffer_t *i_b0;
	ah_header_t *ah0;
	ipsec_sa_t *sa0;
	u32 sa_index0 = ~0;
	u32 seq;
	ip4_header_t ih4 = 0, oh4 = 0;
	ip6_header_t ih6 = 0, oh6 = 0;
	u8 ip_hdr_size = 0;
	u8 tos = 0;
	u8 ttl = 0;
	u32 ip_version_traffic_class_and_flow_label = 0;
	u8 hop_limit = 0;
	u8 nexthdr = 0;
	u8 icv_padding_len = 0;


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

	next0 = AH_DECRYPT_NEXT_DROP;

	i_b0 = vlib_get_buffer (vm, i_bi0);
	to_next[0] = i_bi0;
	to_next += 1;
	ih4 = vlib_buffer_get_current (i_b0);
	ih6 = vlib_buffer_get_current (i_b0);
	sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
	sa0 = pool_elt_at_index (im->sad, sa_index0);

	if (is_ip6)
	{
	ip6_ext_header_t *prev = NULL;
	ip6_ext_header_find_t (ih6, prev, ah0, IP_PROTOCOL_IPSEC_AH);
	ip_hdr_size = sizeof (ip6_header_t);
	ASSERT ((u8 ) ah0 - (u8 ) ih6 == ip_hdr_size);
	}
	else
	{
	ip_hdr_size = ip4_header_bytes (ih4);
	ah0 = (ah_header_t ) ((u8 ) ih4 + ip_hdr_size);
	}

	seq = clib_host_to_net_u32 (ah0->seq_no);
	/* anti-replay check */
	//TODO UT remaining
	if (sa0->use_anti_replay)
	{
	int rv = 0;

	if (PREDICT_TRUE (sa0->use_esn))
	rv = esp_replay_check_esn (sa0, seq);
	else
	rv = esp_replay_check (sa0, seq);

	if (PREDICT_FALSE (rv))
	{
	clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq);
	if (is_ip6)
	vlib_node_increment_counter (vm,
	ah6_decrypt_node.index,
	AH_DECRYPT_ERROR_REPLAY, 1);
	else
	vlib_node_increment_counter (vm,
	ah4_decrypt_node.index,
	AH_DECRYPT_ERROR_REPLAY, 1);
	to_next[0] = i_bi0;
	to_next += 1;
	goto trace;
	}
	}


	sa0->total_data_size += i_b0->current_length;
	icv_size =
	em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
	if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
	{
	u8 sig[64];
	u8 digest[64];
	clib_memset (sig, 0, sizeof (sig));
	clib_memset (digest, 0, sizeof (digest));
	u8 *icv = ah0->auth_data;
	memcpy (digest, icv, icv_size);
	clib_memset (icv, 0, icv_size);

	if (is_ip6)
	{
	ip_version_traffic_class_and_flow_label =
	ih6->ip_version_traffic_class_and_flow_label;
	hop_limit = ih6->hop_limit;
	ih6->ip_version_traffic_class_and_flow_label = 0x60;
	ih6->hop_limit = 0;
	nexthdr = ah0->nexthdr;
	icv_padding_len =
	ah_calc_icv_padding_len (icv_size, 1 /* is_ipv6 */ );
	}
	else
	{
	tos = ih4->tos;
	ttl = ih4->ttl;
	ih4->tos = 0;
	ih4->ttl = 0;
	ih4->checksum = 0;
	ih4->flags_and_fragment_offset = 0;
	icv_padding_len =
	ah_calc_icv_padding_len (icv_size, 0 /* is_ipv6 */ );
	}
	hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len,
	(u8 *) ih4, i_b0->current_length, sig, sa0->use_esn,
	sa0->seq_hi);

	if (PREDICT_FALSE (memcmp (digest, sig, icv_size)))
	{
	if (is_ip6)
	vlib_node_increment_counter (vm,
	ah6_decrypt_node.index,
	AH_DECRYPT_ERROR_INTEG_ERROR,
	1);
	else
	vlib_node_increment_counter (vm,
	ah4_decrypt_node.index,
	AH_DECRYPT_ERROR_INTEG_ERROR,
	1);
	to_next[0] = i_bi0;
	to_next += 1;
	goto trace;
	}

	//TODO UT remaining
	if (PREDICT_TRUE (sa0->use_anti_replay))
	{
	if (PREDICT_TRUE (sa0->use_esn))
	esp_replay_advance_esn (sa0, seq);
	else
	esp_replay_advance (sa0, seq);
	}

	}

	vlib_buffer_advance (i_b0,
	ip_hdr_size + sizeof (ah_header_t) + icv_size +
	icv_padding_len);
	i_b0->flags \|= VLIB_BUFFER_TOTAL_LENGTH_VALID;

	if (PREDICT_TRUE (sa0->is_tunnel))
	{ /* tunnel mode */
	if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP))
	next0 = AH_DECRYPT_NEXT_IP4_INPUT;
	else if (ah0->nexthdr == IP_PROTOCOL_IPV6)
	next0 = AH_DECRYPT_NEXT_IP6_INPUT;
	else
	{
	clib_warning ("next header: 0x%x", ah0->nexthdr);
	if (is_ip6)
	vlib_node_increment_counter (vm,
	ah6_decrypt_node.index,
	AH_DECRYPT_ERROR_DECRYPTION_FAILED,
	1);
	else
	vlib_node_increment_counter (vm,
	ah4_decrypt_node.index,
	AH_DECRYPT_ERROR_DECRYPTION_FAILED,
	1);
	goto trace;
	}
	}
	else
	{ /* transport mode */
	if (is_ip6)
	{
	vlib_buffer_advance (i_b0, -sizeof (ip6_header_t));
	oh6 = vlib_buffer_get_current (i_b0);
	memmove (oh6, ih6, sizeof (ip6_header_t));

	next0 = AH_DECRYPT_NEXT_IP6_INPUT;
	oh6->protocol = nexthdr;
	oh6->hop_limit = hop_limit;
	oh6->ip_version_traffic_class_and_flow_label =
	ip_version_traffic_class_and_flow_label;
	oh6->payload_length =
	clib_host_to_net_u16 (vlib_buffer_length_in_chain
	(vm, i_b0) - sizeof (ip6_header_t));
	}
	else
	{
	vlib_buffer_advance (i_b0, -sizeof (ip4_header_t));
	oh4 = vlib_buffer_get_current (i_b0);
	memmove (oh4, ih4, sizeof (ip4_header_t));

	next0 = AH_DECRYPT_NEXT_IP4_INPUT;
	oh4->ip_version_and_header_length = 0x45;
	oh4->fragment_id = 0;
	oh4->flags_and_fragment_offset = 0;
	oh4->protocol = ah0->nexthdr;
	oh4->length =
	clib_host_to_net_u16 (vlib_buffer_length_in_chain
	(vm, i_b0));
	oh4->ttl = ttl;
	oh4->tos = tos;
	oh4->checksum = ip4_header_checksum (oh4);
	}
	}

	/* for IPSec-GRE tunnel next node is ipsec-gre-input */
	if (PREDICT_FALSE
	((vnet_buffer (i_b0)->ipsec.flags) &
	IPSEC_FLAG_IPSEC_GRE_TUNNEL))
	next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT;


	vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
	trace:
	if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
	{
	i_b0->flags \|= VLIB_BUFFER_IS_TRACED;
	ah_decrypt_trace_t *tr =
	vlib_add_trace (vm, node, i_b0, sizeof (*tr));
	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_decrypt_node.index,
	AH_DECRYPT_ERROR_RX_PKTS,
	from_frame->n_vectors);
	else
	vlib_node_increment_counter (vm, ah4_decrypt_node.index,
	AH_DECRYPT_ERROR_RX_PKTS,
	from_frame->n_vectors);

	return from_frame->n_vectors;
	}

	static uword
	ah4_decrypt_node_fn (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * from_frame)
	{
	return ah_decrypt_inline (vm, node, from_frame, 0 /* is_ip6 */ );
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (ah4_decrypt_node) = {
	.function = ah4_decrypt_node_fn,
	.name = "ah4-decrypt",
	.vector_size = sizeof (u32),
	.format_trace = format_ah_decrypt_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(ah_decrypt_error_strings),
	.error_strings = ah_decrypt_error_strings,

	.n_next_nodes = AH_DECRYPT_N_NEXT,
	.next_nodes = {
	#define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
	foreach_ah_decrypt_next
	#undef _
	},
	};
	/* INDENT-ON */

	VLIB_NODE_FUNCTION_MULTIARCH (ah4_decrypt_node, ah4_decrypt_node_fn);

	static uword
	ah6_decrypt_node_fn (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * from_frame)
	{
	return ah_decrypt_inline (vm, node, from_frame, 1 /* is_ip6 */ );
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (ah6_decrypt_node) = {
	.function = ah6_decrypt_node_fn,
	.name = "ah6-decrypt",
	.vector_size = sizeof (u32),
	.format_trace = format_ah_decrypt_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(ah_decrypt_error_strings),
	.error_strings = ah_decrypt_error_strings,

	.n_next_nodes = AH_DECRYPT_N_NEXT,
	.next_nodes = {
	#define _(s,n) [AH_DECRYPT_NEXT_##s] = n,
	foreach_ah_decrypt_next
	#undef _
	},
	};
	/* INDENT-ON */

	VLIB_NODE_FUNCTION_MULTIARCH (ah6_decrypt_node, ah6_decrypt_node_fn);
	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/