ipsec: esp-encrypt and esp-decrypt cleanup

Change-Id: I1e431aa36a282ca7565c6618a940d591674b8cd2
Signed-off-by: Damjan Marion <damarion@cisco.com>

4 files changed, 447 insertions, 558 deletions

diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c
index 0cb5c154895..7e5114ce2cf 100644
--- a/src/vnet/ipsec/esp_decrypt.c
+++ b/src/vnet/ipsec/esp_decrypt.c
@@ -118,296 +118,255 @@ esp_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;
-  u32 *recycle = 0;
-  from = vlib_frame_vector_args (from_frame);
-  n_left_from = from_frame->n_vectors;
-  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))
+  u32 *from = vlib_frame_vector_args (from_frame);
+  u32 n_left_from = from_frame->n_vectors;
+  u32 new_bufs[VLIB_FRAME_SIZE];
+  vlib_buffer_t *i_bufs[VLIB_FRAME_SIZE], **ib = i_bufs;
+  vlib_buffer_t *o_bufs[VLIB_FRAME_SIZE], **ob = o_bufs;
+  u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
+  u32 n_alloc, thread_index = vm->thread_index;
+
+  n_alloc = vlib_buffer_alloc (vm, new_bufs, n_left_from);
+  if (n_alloc != n_left_from)
     {
       vlib_node_increment_counter (vm, node->node_index,
-				   ESP_DECRYPT_ERROR_NO_BUFFER, n_left_from);
-      goto free_buffers_and_exit;
+				   ESP_DECRYPT_ERROR_NO_BUFFER,
+				   n_left_from - n_alloc);
+      if (n_alloc == 0)
+	goto done;
+      n_left_from = n_alloc;
     }
 
-  next_index = node->cached_next_index;
+  vlib_get_buffers (vm, from, ib, n_left_from);
+  vlib_get_buffers (vm, new_bufs, ob, n_left_from);
 
   while (n_left_from > 0)
     {
-      u32 n_left_to_next;
+      esp_header_t *esp0;
+      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 tunnel_mode = 1;
+
+      next[0] = ESP_DECRYPT_NEXT_DROP;
+
+      esp0 = vlib_buffer_get_current (ib[0]);
+      sa_index0 = vnet_buffer (ib[0])->ipsec.sad_index;
+      sa0 = pool_elt_at_index (im->sad, sa_index0);
+      seq = clib_host_to_net_u32 (esp0->seq);
+
+      /* anti-replay check */
+      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))
+	    {
+	      u32 tmp, off = n_alloc - n_left_from;
+	      /* send original packet to drop node */
+	      tmp = from[off];
+	      from[off] = new_bufs[off];
+	      new_bufs[off] = tmp;
+	      ib[0]->error = node->errors[ESP_DECRYPT_ERROR_REPLAY];
+	      next[0] = ESP_DECRYPT_NEXT_DROP;
+	      goto trace;
+	    }
+	}
 
-      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+      vlib_increment_combined_counter
+	(&ipsec_sa_counters, thread_index, sa_index0,
+	 1, ib[0]->current_length);
 
-      while (n_left_from > 0 && n_left_to_next > 0)
+      if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
 	{
-	  u32 i_bi0, o_bi0 = (u32) ~ 0, next0;
-	  vlib_buffer_t *i_b0;
-	  vlib_buffer_t *o_b0 = 0;
-	  esp_header_t *esp0;
-	  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 tunnel_mode = 1;
-
-	  i_bi0 = from[0];
-	  from += 1;
-	  n_left_from -= 1;
-	  n_left_to_next -= 1;
-
-	  next0 = ESP_DECRYPT_NEXT_DROP;
-
-	  i_b0 = vlib_get_buffer (vm, i_bi0);
-	  esp0 = vlib_buffer_get_current (i_b0);
-
-	  sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index;
-	  sa0 = pool_elt_at_index (im->sad, sa_index0);
-
-	  seq = clib_host_to_net_u32 (esp0->seq);
-
-	  /* anti-replay check */
-	  if (sa0->use_anti_replay)
+	  u8 sig[64];
+	  int icv_size =
+	    em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
+	  clib_memset (sig, 0, sizeof (sig));
+	  u8 *icv =
+	    vlib_buffer_get_current (ib[0]) + ib[0]->current_length -
+	    icv_size;
+	  ib[0]->current_length -= icv_size;
+
+	  hmac_calc (sa0->integ_alg, sa0->integ_key.data,
+		     sa0->integ_key.len, (u8 *) esp0,
+		     ib[0]->current_length, sig, sa0->use_esn, sa0->seq_hi);
+
+	  if (PREDICT_FALSE (memcmp (icv, sig, icv_size)))
 	    {
-	      int rv = 0;
+	      u32 tmp, off = n_alloc - n_left_from;
+	      /* send original packet to drop node */
+	      tmp = from[off];
+	      from[off] = new_bufs[off];
+	      new_bufs[off] = tmp;
+	      ib[0]->error = node->errors[ESP_DECRYPT_ERROR_INTEG_ERROR];
+	      next[0] = ESP_DECRYPT_NEXT_DROP;
+	      goto trace;
+	    }
+	}
 
-	      if (PREDICT_TRUE (sa0->use_esn))
-		rv = esp_replay_check_esn (sa0, seq);
-	      else
-		rv = esp_replay_check (sa0, seq);
+      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);
+	}
+
+      if ((sa0->crypto_alg >= IPSEC_CRYPTO_ALG_AES_CBC_128 &&
+	   sa0->crypto_alg <= IPSEC_CRYPTO_ALG_AES_CBC_256) ||
+	  (sa0->crypto_alg >= IPSEC_CRYPTO_ALG_DES_CBC &&
+	   sa0->crypto_alg <= IPSEC_CRYPTO_ALG_3DES_CBC))
+	{
+	  const int BLOCK_SIZE =
+	    em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;;
+	  const int IV_SIZE =
+	    em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
+	  esp_footer_t *f0;
+	  u8 ip_hdr_size = 0;
+
+	  int blocks =
+	    (ib[0]->current_length - sizeof (esp_header_t) -
+	     IV_SIZE) / BLOCK_SIZE;
+
+	  ob[0]->current_data = sizeof (ethernet_header_t);
+
+	  /* transport mode */
+	  if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6))
+	    {
+	      tunnel_mode = 0;
 
-	      if (PREDICT_FALSE (rv))
+	      if (is_ip6)
 		{
-		  vlib_node_increment_counter (vm, node->node_index,
-					       ESP_DECRYPT_ERROR_REPLAY, 1);
-		  o_bi0 = i_bi0;
-		  to_next[0] = o_bi0;
-		  to_next += 1;
-		  goto trace;
+		  ip_hdr_size = sizeof (ip6_header_t);
+		  ih6 = (ip6_header_t *) ((u8 *) esp0 - ip_hdr_size);
+		  oh6 = vlib_buffer_get_current (ob[0]);
+		}
+	      else
+		{
+		  ip_hdr_size = sizeof (ip4_header_t);
+		  if (sa0->udp_encap)
+		    ih4 = (ip4_header_t *) ((u8 *) esp0 - ip_hdr_size -
+					    sizeof (udp_header_t));
+		  else
+		    ih4 = (ip4_header_t *) ((u8 *) esp0 - ip_hdr_size);
+		  oh4 = vlib_buffer_get_current (ob[0]);
 		}
 	    }
 
-	  vlib_increment_combined_counter
-	    (&ipsec_sa_counters, thread_index, sa_index0,
-	     1, i_b0->current_length);
+	  esp_decrypt_cbc (sa0->crypto_alg,
+			   esp0->data + IV_SIZE,
+			   (u8 *) vlib_buffer_get_current (ob[0]) +
+			   ip_hdr_size, BLOCK_SIZE * blocks,
+			   sa0->crypto_key.data, esp0->data);
+
+	  ob[0]->current_length = (blocks * BLOCK_SIZE) - 2 + ip_hdr_size;
+	  ob[0]->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
+	  f0 = (esp_footer_t *) ((u8 *) vlib_buffer_get_current (ob[0]) +
+				 ob[0]->current_length);
+	  ob[0]->current_length -= f0->pad_length;
 
-	  if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE))
+	  /* tunnel mode */
+	  if (PREDICT_TRUE (tunnel_mode))
 	    {
-	      u8 sig[64];
-	      int icv_size =
-		em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size;
-	      clib_memset (sig, 0, sizeof (sig));
-	      u8 *icv =
-		vlib_buffer_get_current (i_b0) + i_b0->current_length -
-		icv_size;
-	      i_b0->current_length -= icv_size;
-
-	      hmac_calc (sa0->integ_alg, sa0->integ_key.data,
-			 sa0->integ_key.len, (u8 *) esp0,
-			 i_b0->current_length, sig, sa0->use_esn,
-			 sa0->seq_hi);
-
-	      if (PREDICT_FALSE (memcmp (icv, sig, icv_size)))
+	      if (PREDICT_TRUE (f0->next_header == IP_PROTOCOL_IP_IN_IP))
+		{
+		  next[0] = ESP_DECRYPT_NEXT_IP4_INPUT;
+		  oh4 = vlib_buffer_get_current (ob[0]);
+		}
+	      else if (f0->next_header == IP_PROTOCOL_IPV6)
+		next[0] = ESP_DECRYPT_NEXT_IP6_INPUT;
+	      else
 		{
 		  vlib_node_increment_counter (vm, node->node_index,
-					       ESP_DECRYPT_ERROR_INTEG_ERROR,
+					       ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
 					       1);
-		  o_bi0 = i_bi0;
-		  to_next[0] = o_bi0;
-		  to_next += 1;
+		  ob[0] = 0;
 		  goto trace;
 		}
 	    }
-
-	  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);
-	    }
-
-	  /* grab free buffer */
-	  uword last_empty_buffer = vec_len (empty_buffers) - 1;
-	  o_bi0 = empty_buffers[last_empty_buffer];
-	  to_next[0] = o_bi0;
-	  to_next += 1;
-	  o_b0 = vlib_get_buffer (vm, o_bi0);
-	  vlib_prefetch_buffer_with_index (vm,
-					   empty_buffers[last_empty_buffer -
-							 1], STORE);
-	  _vec_len (empty_buffers) = last_empty_buffer;
-
-	  /* add old buffer to the recycle list */
-	  vec_add1 (recycle, i_bi0);
-
-	  if ((sa0->crypto_alg >= IPSEC_CRYPTO_ALG_AES_CBC_128 &&
-	       sa0->crypto_alg <= IPSEC_CRYPTO_ALG_AES_CBC_256) ||
-	      (sa0->crypto_alg >= IPSEC_CRYPTO_ALG_DES_CBC &&
-	       sa0->crypto_alg <= IPSEC_CRYPTO_ALG_3DES_CBC))
+	  /* transport mode */
+	  else
 	    {
-	      const int BLOCK_SIZE =
-		em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;;
-	      const int IV_SIZE =
-		em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
-	      esp_footer_t *f0;
-	      u8 ip_hdr_size = 0;
-
-	      int blocks =
-		(i_b0->current_length - sizeof (esp_header_t) -
-		 IV_SIZE) / BLOCK_SIZE;
-
-	      o_b0->current_data = sizeof (ethernet_header_t);
-
-	      /* transport mode */
-	      if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6))
+	      u32 len = vlib_buffer_length_in_chain (vm, ob[0]);
+	      if (is_ip6)
 		{
-		  tunnel_mode = 0;
-
-		  if (is_ip6)
-		    {
-		      ih6 =
-			(ip6_header_t *) ((u8 *) esp0 -
-					  sizeof (ip6_header_t));
-		      ip_hdr_size = sizeof (ip6_header_t);
-		      oh6 = vlib_buffer_get_current (o_b0);
-		    }
-		  else
-		    {
-		      if (sa0->udp_encap)
-			{
-			  ih4 =
-			    (ip4_header_t *) ((u8 *) esp0 -
-					      sizeof (udp_header_t) -
-					      sizeof (ip4_header_t));
-			}
-		      else
-			{
-			  ih4 =
-			    (ip4_header_t *) ((u8 *) esp0 -
-					      sizeof (ip4_header_t));
-			}
-		      oh4 = vlib_buffer_get_current (o_b0);
-		      ip_hdr_size = sizeof (ip4_header_t);
-		    }
+		  next[0] = ESP_DECRYPT_NEXT_IP6_INPUT;
+		  oh6->ip_version_traffic_class_and_flow_label =
+		    ih6->ip_version_traffic_class_and_flow_label;
+		  oh6->protocol = f0->next_header;
+		  oh6->hop_limit = ih6->hop_limit;
+		  oh6->src_address.as_u64[0] = ih6->src_address.as_u64[0];
+		  oh6->src_address.as_u64[1] = ih6->src_address.as_u64[1];
+		  oh6->dst_address.as_u64[0] = ih6->dst_address.as_u64[0];
+		  oh6->dst_address.as_u64[1] = ih6->dst_address.as_u64[1];
+		  len -= sizeof (ip6_header_t);
+		  oh6->payload_length = clib_host_to_net_u16 (len);
 		}
-
-	      esp_decrypt_cbc (sa0->crypto_alg,
-			       esp0->data + IV_SIZE,
-			       (u8 *) vlib_buffer_get_current (o_b0) +
-			       ip_hdr_size, BLOCK_SIZE * blocks,
-			       sa0->crypto_key.data, esp0->data);
-
-	      o_b0->current_length = (blocks * BLOCK_SIZE) - 2 + ip_hdr_size;
-	      o_b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
-	      f0 =
-		(esp_footer_t *) ((u8 *) vlib_buffer_get_current (o_b0) +
-				  o_b0->current_length);
-	      o_b0->current_length -= f0->pad_length;
-
-	      /* tunnel mode */
-	      if (PREDICT_TRUE (tunnel_mode))
-		{
-		  if (PREDICT_TRUE (f0->next_header == IP_PROTOCOL_IP_IN_IP))
-		    {
-		      next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
-		      oh4 = vlib_buffer_get_current (o_b0);
-		    }
-		  else if (f0->next_header == IP_PROTOCOL_IPV6)
-		    next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
-		  else
-		    {
-		      vlib_node_increment_counter (vm, node->node_index,
-						   ESP_DECRYPT_ERROR_DECRYPTION_FAILED,
-						   1);
-		      o_b0 = 0;
-		      goto trace;
-		    }
-		}
-	      /* transport mode */
 	      else
 		{
-		  if (is_ip6)
-		    {
-		      next0 = ESP_DECRYPT_NEXT_IP6_INPUT;
-		      oh6->ip_version_traffic_class_and_flow_label =
-			ih6->ip_version_traffic_class_and_flow_label;
-		      oh6->protocol = f0->next_header;
-		      oh6->hop_limit = ih6->hop_limit;
-		      oh6->src_address.as_u64[0] = ih6->src_address.as_u64[0];
-		      oh6->src_address.as_u64[1] = ih6->src_address.as_u64[1];
-		      oh6->dst_address.as_u64[0] = ih6->dst_address.as_u64[0];
-		      oh6->dst_address.as_u64[1] = ih6->dst_address.as_u64[1];
-		      oh6->payload_length =
-			clib_host_to_net_u16 (vlib_buffer_length_in_chain
-					      (vm,
-					       o_b0) - sizeof (ip6_header_t));
-		    }
-		  else
-		    {
-		      next0 = ESP_DECRYPT_NEXT_IP4_INPUT;
-		      oh4->ip_version_and_header_length = 0x45;
-		      oh4->tos = ih4->tos;
-		      oh4->fragment_id = 0;
-		      oh4->flags_and_fragment_offset = 0;
-		      oh4->ttl = ih4->ttl;
-		      oh4->protocol = f0->next_header;
-		      oh4->src_address.as_u32 = ih4->src_address.as_u32;
-		      oh4->dst_address.as_u32 = ih4->dst_address.as_u32;
-		      oh4->length =
-			clib_host_to_net_u16 (vlib_buffer_length_in_chain
-					      (vm, o_b0));
-		      oh4->checksum = ip4_header_checksum (oh4);
-		    }
+		  next[0] = ESP_DECRYPT_NEXT_IP4_INPUT;
+		  oh4->ip_version_and_header_length = 0x45;
+		  oh4->tos = ih4->tos;
+		  oh4->fragment_id = 0;
+		  oh4->flags_and_fragment_offset = 0;
+		  oh4->ttl = ih4->ttl;
+		  oh4->protocol = f0->next_header;
+		  oh4->src_address.as_u32 = ih4->src_address.as_u32;
+		  oh4->dst_address.as_u32 = ih4->dst_address.as_u32;
+		  oh4->length = clib_host_to_net_u16 (len);
+		  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 = ESP_DECRYPT_NEXT_IPSEC_GRE_INPUT;
+	  /* for IPSec-GRE tunnel next node is ipsec-gre-input */
+	  if (PREDICT_FALSE
+	      ((vnet_buffer (ib[0])->ipsec.flags) &
+	       IPSEC_FLAG_IPSEC_GRE_TUNNEL))
+	    next[0] = ESP_DECRYPT_NEXT_IPSEC_GRE_INPUT;
 
-	      vnet_buffer (o_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
-	      vnet_buffer (o_b0)->sw_if_index[VLIB_RX] =
-		vnet_buffer (i_b0)->sw_if_index[VLIB_RX];
-	    }
+	  vnet_buffer (ob[0])->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	  vnet_buffer (ob[0])->sw_if_index[VLIB_RX] =
+	    vnet_buffer (ib[0])->sw_if_index[VLIB_RX];
+	}
 
-	trace:
-	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
+    trace:
+      if (PREDICT_FALSE (ib[0]->flags & VLIB_BUFFER_IS_TRACED))
+	{
+	  if (ob[0])
 	    {
-	      if (o_b0)
-		{
-		  o_b0->flags |= VLIB_BUFFER_IS_TRACED;
-		  o_b0->trace_index = i_b0->trace_index;
-		  esp_decrypt_trace_t *tr =
-		    vlib_add_trace (vm, node, o_b0, sizeof (*tr));
-		  tr->crypto_alg = sa0->crypto_alg;
-		  tr->integ_alg = sa0->integ_alg;
-		}
+	      ob[0]->flags |= VLIB_BUFFER_IS_TRACED;
+	      ob[0]->trace_index = ib[0]->trace_index;
+	      esp_decrypt_trace_t *tr =
+		vlib_add_trace (vm, node, ob[0], sizeof (*tr));
+	      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);
+
+      /* next */
+      n_left_from -= 1;
+      ib += 1;
+      ob += 1;
+      next += 1;
     }
-  vlib_node_increment_counter (vm, node->node_index,
-			       ESP_DECRYPT_ERROR_RX_PKTS,
-			       from_frame->n_vectors);
 
+  vlib_node_increment_counter (vm, node->node_index,
+			       ESP_DECRYPT_ERROR_RX_PKTS, n_alloc);
 
-free_buffers_and_exit:
-  if (recycle)
-    vlib_buffer_free (vm, recycle, vec_len (recycle));
-  vec_free (recycle);
-  return from_frame->n_vectors;
+  vlib_buffer_enqueue_to_next (vm, node, new_bufs, nexts, n_alloc);
+done:
+  vlib_buffer_free (vm, from, from_frame->n_vectors);
+  return n_alloc;
 }
 
 VLIB_NODE_FN (esp4_decrypt_node) (vlib_main_t * vm,
diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index 1e0bd7facf5..080a3458926 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -122,325 +122,282 @@ esp_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;
-  from = vlib_frame_vector_args (from_frame);
-  n_left_from = from_frame->n_vectors;
+  u32 *from = vlib_frame_vector_args (from_frame);
+  u32 n_left_from = from_frame->n_vectors;
   ipsec_main_t *im = &ipsec_main;
   ipsec_proto_main_t *em = &ipsec_proto_main;
-  u32 *recycle = 0;
-  u32 thread_index = vm->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))
+  u32 new_bufs[VLIB_FRAME_SIZE];
+  vlib_buffer_t *i_bufs[VLIB_FRAME_SIZE], **ib = i_bufs;
+  vlib_buffer_t *o_bufs[VLIB_FRAME_SIZE], **ob = o_bufs;
+  u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
+  u32 n_alloc, thread_index = vm->thread_index;
+
+  n_alloc = vlib_buffer_alloc (vm, new_bufs, n_left_from);
+  if (n_alloc != n_left_from)
     {
       vlib_node_increment_counter (vm, node->node_index,
-				   ESP_ENCRYPT_ERROR_NO_BUFFER, n_left_from);
-      clib_warning ("not enough empty buffers. discarding frame");
-      goto free_buffers_and_exit;
+				   ESP_ENCRYPT_ERROR_NO_BUFFER,
+				   n_left_from - n_alloc);
+      if (n_alloc == 0)
+	goto done;
+      n_left_from = n_alloc;
     }
 
-  next_index = node->cached_next_index;
+  vlib_get_buffers (vm, from, ib, n_left_from);
+  vlib_get_buffers (vm, new_bufs, ob, n_left_from);
 
   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 sa_index0;
+      ipsec_sa_t *sa0;
+      ip4_and_esp_header_t *oh0 = 0;
+      ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
+      ip4_and_udp_and_esp_header_t *iuh0, *ouh0 = 0;
+      esp_header_t *o_esp0;
+      esp_footer_t *f0;
+      u8 ip_udp_hdr_size;
+      u8 next_hdr_type;
+      u32 ip_proto = 0;
+      u8 transport_mode = 0;
+      u32 esp_seq_err;
+
+      next[0] = ESP_ENCRYPT_NEXT_DROP;
+
+      sa_index0 = vnet_buffer (ib[0])->ipsec.sad_index;
+      sa0 = pool_elt_at_index (im->sad, sa_index0);
+
+      vlib_prefetch_combined_counter (&ipsec_sa_counters, thread_index,
+				      sa_index0);
+
+      esp_seq_err = esp_seq_advance (sa0);
+
+      /* grab free buffer */
+      ob[0]->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
+      ob[0]->current_data = sizeof (ethernet_header_t);
+      iuh0 = vlib_buffer_get_current (ib[0]);
+
+      if (is_ip6)
 	{
-	  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 *oh0 = 0;
-	  ip6_and_esp_header_t *ih6_0, *oh6_0 = 0;
-	  ip4_and_udp_and_esp_header_t *iuh0, *ouh0 = 0;
-	  uword last_empty_buffer;
-	  esp_header_t *o_esp0;
-	  esp_footer_t *f0;
-	  u8 ip_udp_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);
-
-	  vlib_prefetch_combined_counter
-	    (&ipsec_sa_counters, thread_index, 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, node->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;
-	    }
-
-	  /* 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);
-	  iuh0 = 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);
-
-	  if (is_ip6)
+	  ih6_0 = vlib_buffer_get_current (ib[0]);
+	  next_hdr_type = IP_PROTOCOL_IPV6;
+	  oh6_0 = vlib_buffer_get_current (ob[0]);
+
+	  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;
+	  ip_udp_hdr_size = sizeof (ip6_header_t);
+	  o_esp0 = vlib_buffer_get_current (ob[0]) + ip_udp_hdr_size;
+	  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];
+	  o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
+	  o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
+	  ip_proto = ih6_0->ip6.protocol;
+
+	  next[0] = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
+	}
+      else
+	{
+	  next_hdr_type = IP_PROTOCOL_IP_IN_IP;
+	  oh0 = vlib_buffer_get_current (ob[0]);
+	  ouh0 = vlib_buffer_get_current (ob[0]);
+
+	  oh0->ip4.ip_version_and_header_length = 0x45;
+	  oh0->ip4.tos = iuh0->ip4.tos;
+	  oh0->ip4.fragment_id = 0;
+	  oh0->ip4.flags_and_fragment_offset = 0;
+	  oh0->ip4.ttl = 254;
+	  if (sa0->udp_encap)
 	    {
-	      ih6_0 = vlib_buffer_get_current (i_b0);
-	      next_hdr_type = IP_PROTOCOL_IPV6;
-	      oh6_0 = vlib_buffer_get_current (o_b0);
-
-	      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;
-	      ip_udp_hdr_size = sizeof (ip6_header_t);
-	      o_esp0 = vlib_buffer_get_current (o_b0) + ip_udp_hdr_size;
-	      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];
-	      o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
-	      o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
-	      ip_proto = ih6_0->ip6.protocol;
-
-	      next0 = ESP_ENCRYPT_NEXT_IP6_LOOKUP;
+	      ouh0->udp.src_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
+	      ouh0->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
+	      ouh0->udp.checksum = 0;
+	      ouh0->ip4.protocol = IP_PROTOCOL_UDP;
+	      ip_udp_hdr_size = sizeof (udp_header_t) + sizeof (ip4_header_t);
 	    }
 	  else
 	    {
-	      next_hdr_type = IP_PROTOCOL_IP_IN_IP;
-	      oh0 = vlib_buffer_get_current (o_b0);
-	      ouh0 = vlib_buffer_get_current (o_b0);
-
-	      oh0->ip4.ip_version_and_header_length = 0x45;
-	      oh0->ip4.tos = iuh0->ip4.tos;
-	      oh0->ip4.fragment_id = 0;
-	      oh0->ip4.flags_and_fragment_offset = 0;
-	      oh0->ip4.ttl = 254;
-	      if (sa0->udp_encap)
-		{
-		  ouh0->udp.src_port =
-		    clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
-		  ouh0->udp.dst_port =
-		    clib_host_to_net_u16 (UDP_DST_PORT_ipsec);
-		  ouh0->udp.checksum = 0;
-		  ouh0->ip4.protocol = IP_PROTOCOL_UDP;
-		  ip_udp_hdr_size =
-		    sizeof (udp_header_t) + sizeof (ip4_header_t);
-		}
-	      else
-		{
-		  oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
-		  ip_udp_hdr_size = sizeof (ip4_header_t);
-		}
-	      o_esp0 = vlib_buffer_get_current (o_b0) + ip_udp_hdr_size;
-	      oh0->ip4.src_address.as_u32 = iuh0->ip4.src_address.as_u32;
-	      oh0->ip4.dst_address.as_u32 = iuh0->ip4.dst_address.as_u32;
-	      o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
-	      o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
-	      ip_proto = iuh0->ip4.protocol;
-
-	      next0 = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
+	      oh0->ip4.protocol = IP_PROTOCOL_IPSEC_ESP;
+	      ip_udp_hdr_size = sizeof (ip4_header_t);
 	    }
+	  o_esp0 = vlib_buffer_get_current (ob[0]) + ip_udp_hdr_size;
+	  oh0->ip4.src_address.as_u32 = iuh0->ip4.src_address.as_u32;
+	  oh0->ip4.dst_address.as_u32 = iuh0->ip4.dst_address.as_u32;
+	  o_esp0->spi = clib_net_to_host_u32 (sa0->spi);
+	  o_esp0->seq = clib_net_to_host_u32 (sa0->seq);
+	  ip_proto = iuh0->ip4.protocol;
+
+	  next[0] = ESP_ENCRYPT_NEXT_IP4_LOOKUP;
+	}
 
-	  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;
+      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 = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
-	      vnet_buffer (o_b0)->ip.adj_index[VLIB_TX] =
-		sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
-	    }
-	  else if (is_ip6 && sa0->is_tunnel && sa0->is_tunnel_ip6)
+	  next[0] = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
+	  vnet_buffer (ob[0])->ip.adj_index[VLIB_TX] =
+	    sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
+	}
+      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];
+
+	  next[0] = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
+	  vnet_buffer (ob[0])->ip.adj_index[VLIB_TX] =
+	    sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
+	}
+      else
+	{
+	  next_hdr_type = ip_proto;
+	  if (vnet_buffer (ib[0])->sw_if_index[VLIB_TX] != ~0)
 	    {
-	      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 = sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_next_node;
-	      vnet_buffer (o_b0)->ip.adj_index[VLIB_TX] =
-		sa0->dpo[IPSEC_PROTOCOL_ESP].dpoi_index;
+	      transport_mode = 1;
+	      ethernet_header_t *ieh0, *oeh0;
+	      ieh0 =
+		(ethernet_header_t *) ((u8 *)
+				       vlib_buffer_get_current (ib[0]) -
+				       sizeof (ethernet_header_t));
+	      oeh0 = (ethernet_header_t *) ob[0]->data;
+	      clib_memcpy_fast (oeh0, ieh0, sizeof (ethernet_header_t));
+	      next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
+	      vnet_buffer (ob[0])->sw_if_index[VLIB_TX] =
+		vnet_buffer (ib[0])->sw_if_index[VLIB_TX];
 	    }
+
+	  if (is_ip6)
+	    vlib_buffer_advance (ib[0], sizeof (ip6_header_t));
 	  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_fast (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];
-		}
-
-	      if (is_ip6)
-		{
-		  vlib_buffer_advance (i_b0, sizeof (ip6_header_t));
-		}
-	      else
-		{
-		  vlib_buffer_advance (i_b0, sizeof (ip4_header_t));
-		}
-	    }
+	    vlib_buffer_advance (ib[0], sizeof (ip4_header_t));
+	}
 
-	  ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);
-	  vlib_increment_combined_counter
-	    (&ipsec_sa_counters, thread_index, sa_index0,
-	     1, i_b0->current_length);
+      ASSERT (sa0->crypto_alg < IPSEC_CRYPTO_N_ALG);
+      vlib_increment_combined_counter
+	(&ipsec_sa_counters, thread_index, sa_index0,
+	 1, ib[0]->current_length);
 
-	  if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
-	    {
+      if (PREDICT_TRUE (sa0->crypto_alg != IPSEC_CRYPTO_ALG_NONE))
+	{
 
-	      const int BLOCK_SIZE =
-		em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;
-	      const int IV_SIZE =
-		em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
-	      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_udp_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[em->
-		    ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size];
-	      RAND_bytes (iv, sizeof (iv));
-
-	      clib_memcpy_fast ((u8 *) vlib_buffer_get_current (o_b0) +
-				ip_udp_hdr_size + sizeof (esp_header_t), iv,
-				em->ipsec_proto_main_crypto_algs[sa0->
-								 crypto_alg].iv_size);
-
-	      esp_encrypt_cbc (vm, sa0->crypto_alg,
-			       (u8 *) vlib_buffer_get_current (i_b0),
-			       (u8 *) vlib_buffer_get_current (o_b0) +
-			       ip_udp_hdr_size + sizeof (esp_header_t) +
-			       IV_SIZE, BLOCK_SIZE * blocks,
-			       sa0->crypto_key.data, iv);
+	  const int BLOCK_SIZE =
+	    em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].block_size;
+	  const int IV_SIZE =
+	    em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size;
+	  int blocks = 1 + (ib[0]->current_length + 1) / BLOCK_SIZE;
+
+	  /* pad packet in input buffer */
+	  u8 pad_bytes = BLOCK_SIZE * blocks - 2 - ib[0]->current_length;
+	  u8 i;
+	  u8 *padding =
+	    vlib_buffer_get_current (ib[0]) + ib[0]->current_length;
+	  ib[0]->current_length = BLOCK_SIZE * blocks;
+	  for (i = 0; i < pad_bytes; ++i)
+	    {
+	      padding[i] = i + 1;
 	    }
+	  f0 = vlib_buffer_get_current (ib[0]) + ib[0]->current_length - 2;
+	  f0->pad_length = pad_bytes;
+	  f0->next_header = next_hdr_type;
+
+	  ob[0]->current_length = ip_udp_hdr_size + sizeof (esp_header_t) +
+	    BLOCK_SIZE * blocks + IV_SIZE;
+
+	  vnet_buffer (ob[0])->sw_if_index[VLIB_RX] =
+	    vnet_buffer (ib[0])->sw_if_index[VLIB_RX];
+
+	  u8 iv[em->ipsec_proto_main_crypto_algs[sa0->crypto_alg].iv_size];
+	  RAND_bytes (iv, sizeof (iv));
+
+	  clib_memcpy_fast ((u8 *) vlib_buffer_get_current (ob[0]) +
+			    ip_udp_hdr_size + sizeof (esp_header_t), iv,
+			    em->ipsec_proto_main_crypto_algs[sa0->
+							     crypto_alg].iv_size);
+
+	  esp_encrypt_cbc (vm, sa0->crypto_alg,
+			   (u8 *) vlib_buffer_get_current (ib[0]),
+			   (u8 *) vlib_buffer_get_current (ob[0]) +
+			   ip_udp_hdr_size + sizeof (esp_header_t) +
+			   IV_SIZE, BLOCK_SIZE * blocks,
+			   sa0->crypto_key.data, iv);
+	}
 
-	  o_b0->current_length +=
-	    hmac_calc (sa0->integ_alg, sa0->integ_key.data,
-		       sa0->integ_key.len, (u8 *) o_esp0,
-		       o_b0->current_length - ip_udp_hdr_size,
-		       vlib_buffer_get_current (o_b0) + o_b0->current_length,
-		       sa0->use_esn, sa0->seq_hi);
+      ob[0]->current_length +=
+	hmac_calc (sa0->integ_alg, sa0->integ_key.data,
+		   sa0->integ_key.len, (u8 *) o_esp0,
+		   ob[0]->current_length - ip_udp_hdr_size,
+		   vlib_buffer_get_current (ob[0]) + ob[0]->current_length,
+		   sa0->use_esn, sa0->seq_hi);
 
 
-	  if (is_ip6)
-	    {
-	      oh6_0->ip6.payload_length =
-		clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, o_b0) -
-				      sizeof (ip6_header_t));
-	    }
-	  else
+      if (is_ip6)
+	{
+	  oh6_0->ip6.payload_length =
+	    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, ob[0]) -
+				  sizeof (ip6_header_t));
+	}
+      else
+	{
+	  oh0->ip4.length =
+	    clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, ob[0]));
+	  oh0->ip4.checksum = ip4_header_checksum (&oh0->ip4);
+	  if (sa0->udp_encap)
 	    {
-	      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 (sa0->udp_encap)
-		{
-		  ouh0->udp.length =
-		    clib_host_to_net_u16 (clib_net_to_host_u16
-					  (oh0->ip4.length) -
-					  ip4_header_bytes (&oh0->ip4));
-		}
+	      ouh0->udp.length =
+		clib_host_to_net_u16 (clib_net_to_host_u16
+				      (oh0->ip4.length) -
+				      ip4_header_bytes (&oh0->ip4));
 	    }
+	}
 
-	  if (transport_mode)
-	    vlib_buffer_reset (o_b0);
+      if (transport_mode)
+	vlib_buffer_reset (ob[0]);
+
+      if (PREDICT_FALSE (esp_seq_err))
+	{
+	  ob[0]->error = node->errors[ESP_ENCRYPT_ERROR_SEQ_CYCLED];
+	  next[0] = ESP_ENCRYPT_NEXT_DROP;
+	}
 
-	trace:
-	  if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED))
+      if (PREDICT_FALSE (ib[0]->flags & VLIB_BUFFER_IS_TRACED))
+	{
+	  if (ob[0])
 	    {
-	      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->sa_index = sa_index0;
-		  tr->spi = sa0->spi;
-		  tr->seq = sa0->seq - 1;
-		  tr->udp_encap = sa0->udp_encap;
-		  tr->crypto_alg = sa0->crypto_alg;
-		  tr->integ_alg = sa0->integ_alg;
-		}
+	      ob[0]->flags |= VLIB_BUFFER_IS_TRACED;
+	      ob[0]->trace_index = ib[0]->trace_index;
+	      esp_encrypt_trace_t *tr =
+		vlib_add_trace (vm, node, ob[0], sizeof (*tr));
+	      tr->sa_index = sa_index0;
+	      tr->spi = sa0->spi;
+	      tr->seq = sa0->seq - 1;
+	      tr->udp_encap = sa0->udp_encap;
+	      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);
+
+      /* next */
+      n_left_from -= 1;
+      ib += 1;
+      ob += 1;
+      next += 1;
     }
+
   vlib_node_increment_counter (vm, node->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;
+			       ESP_ENCRYPT_ERROR_RX_PKTS, n_alloc);
+
+  vlib_buffer_enqueue_to_next (vm, node, new_bufs, nexts, n_alloc);
+done:
+  vlib_buffer_free (vm, from, from_frame->n_vectors);
+  return n_alloc;
 }
 
 VLIB_NODE_FN (esp4_encrypt_node) (vlib_main_t * vm,
diff --git a/src/vnet/ipsec/ipsec.c b/src/vnet/ipsec/ipsec.c
index a1d8f09691b..ce93f32b429 100644
--- a/src/vnet/ipsec/ipsec.c
+++ b/src/vnet/ipsec/ipsec.c
@@ -240,7 +240,6 @@ ipsec_init (vlib_main_t * vm)
 {
   clib_error_t *error;
   ipsec_main_t *im = &ipsec_main;
-  vlib_thread_main_t *tm = vlib_get_thread_main ();
 
   ipsec_rand_seed ();
 
@@ -253,9 +252,6 @@ ipsec_init (vlib_main_t * vm)
   im->sa_index_by_sa_id = hash_create (0, sizeof (uword));
   im->spd_index_by_sw_if_index = hash_create (0, sizeof (uword));
 
-  vec_validate_aligned (im->empty_buffers, tm->n_vlib_mains - 1,
-			CLIB_CACHE_LINE_BYTES);
-
   vlib_node_t *node = vlib_get_node_by_name (vm, (u8 *) "error-drop");
   ASSERT (node);
   im->error_drop_node_index = node->index;
diff --git a/src/vnet/ipsec/ipsec.h b/src/vnet/ipsec/ipsec.h
index 78d000030c9..c877139ba12 100644
--- a/src/vnet/ipsec/ipsec.h
+++ b/src/vnet/ipsec/ipsec.h
@@ -126,8 +126,6 @@ typedef struct
   /* pool of tunnel interfaces */
   ipsec_tunnel_if_t *tunnel_interfaces;
 
-  u32 **empty_buffers;
-
   uword *tunnel_index_by_key;
 
   /* convenience */
@@ -201,27 +199,6 @@ u8 *format_ipsec_replay_window (u8 * s, va_list * args);
  *  inline functions
  */
 
-always_inline void
-ipsec_alloc_empty_buffers (vlib_main_t * vm, ipsec_main_t * im)
-{
-  u32 thread_index = vm->thread_index;
-  uword l = vec_len (im->empty_buffers[thread_index]);
-  uword n_alloc = 0;
-
-  if (PREDICT_FALSE (l < VLIB_FRAME_SIZE))
-    {
-      if (!im->empty_buffers[thread_index])
-	{
-	  vec_alloc (im->empty_buffers[thread_index], 2 * VLIB_FRAME_SIZE);
-	}
-
-      n_alloc = vlib_buffer_alloc (vm, im->empty_buffers[thread_index] + l,
-				   2 * VLIB_FRAME_SIZE - l);
-
-      _vec_len (im->empty_buffers[thread_index]) = l + n_alloc;
-    }
-}
-
 static_always_inline u32
 get_next_output_feature_node_index (vlib_buffer_t * b,
 				    vlib_node_runtime_t * nr)