fib: midchain adjacency optimisations

Type: improvement

 - inline some common encap fixup functions into the midchain
   rewrite node so we don't incur the cost of the virtual function call
 - change the copy 'guess' from ethernet_header (which will never happen) to an ip4 header
 - add adj-midchain-tx to multiarch sources
 - don't run adj-midchain-tx as a feature, instead put this node as the
   adj's next and at the end of the feature arc.
 - cache the feature arc config index (to save the cache miss going to fetch it)
 - don't check if features are enabled when taking the arc (since we know they are)

the last two changes will also benefit normal adjacencies taking the arc (i.e. for NAT, ACLs, etc)

for IPSec:
 - don't run esp_encrypt as a feature, instead when required insert this
   node into the adj's next and into the end of the feature arc. this
   implies that encrypt is always 'the last feature' run, which is
   symmetric with decrypt always being the first.
 - esp_encrpyt for tunnels has adj-midchain-tx as next node

Change-Id: Ida0af56a704302cf2d7797ded5f118a781e8acb7
Signed-off-by: Neale Ranns <nranns@cisco.com>

4 files changed, 120 insertions, 205 deletions

diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index dce887f6fa8..15f590acbdb 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -608,7 +608,7 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
       esp_header_t *esp;
       u8 *payload, *next_hdr_ptr;
       u16 payload_len, payload_len_total, n_bufs;
-      u32 hdr_len, config_index;
+      u32 hdr_len;
 
       if (n_left > 2)
 	{
@@ -623,8 +623,6 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
       if (is_tun)
 	{
 	  /* we are on a ipsec tunnel's feature arc */
-	  config_index = b[0]->current_config_index;
-	  vnet_feature_next_u16 (&next[0], b[0]);
 	  vnet_buffer (b[0])->ipsec.sad_index =
 	    sa_index0 = ipsec_tun_protect_get_sa_out
 	    (vnet_buffer (b[0])->ip.adj_index[VLIB_TX]);
@@ -675,10 +673,6 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
       if (PREDICT_TRUE (thread_index != sa0->encrypt_thread_index))
 	{
 	  next[0] = ESP_ENCRYPT_NEXT_HANDOFF;
-	  if (is_tun)
-	    {
-	      b[0]->current_config_index = config_index;
-	    }
 	  goto trace;
 	}
 
@@ -778,6 +772,8 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	      next[0] = dpo->dpoi_next_node;
 	      vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = dpo->dpoi_index;
 	    }
+	  else
+	    next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 	}
       else			/* transport mode */
 	{
@@ -872,8 +868,7 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	      esp_fill_udp_hdr (sa0, udp, udp_len);
 	    }
 
-	  if (!is_tun)
-	    next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
+	  next[0] = ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT;
 	}
 
       esp->spi = spi;
@@ -1154,7 +1149,7 @@ VLIB_REGISTER_NODE (esp4_encrypt_tun_node) = {
   .next_nodes = {
     [ESP_ENCRYPT_NEXT_DROP] = "ip4-drop",
     [ESP_ENCRYPT_NEXT_HANDOFF] = "esp4-encrypt-tun-handoff",
-    [ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT] = "error-drop",
+    [ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT] = "adj-midchain-tx",
     [ESP_ENCRYPT_NEXT_PENDING] = "esp-encrypt-pending",
   },
 };
@@ -1177,27 +1172,6 @@ VLIB_REGISTER_NODE (esp4_encrypt_tun_post_node) = {
   .n_errors = ARRAY_LEN(esp_encrypt_error_strings),
   .error_strings = esp_encrypt_error_strings,
 };
-
-VNET_FEATURE_INIT (esp4_encrypt_tun_feat_node, static) =
-{
-  .arc_name = "ip4-output",
-  .node_name = "esp4-encrypt-tun",
-  .runs_before = VNET_FEATURES ("adj-midchain-tx"),
-};
-
-VNET_FEATURE_INIT (esp6o4_encrypt_tun_feat_node, static) =
-{
-  .arc_name = "ip6-output",
-  .node_name = "esp4-encrypt-tun",
-  .runs_before = VNET_FEATURES ("adj-midchain-tx"),
-};
-
-VNET_FEATURE_INIT (esp4_ethernet_encrypt_tun_feat_node, static) =
-{
-  .arc_name = "ethernet-output",
-  .node_name = "esp4-encrypt-tun",
-  .runs_before = VNET_FEATURES ("adj-midchain-tx", "adj-midchain-tx-no-count"),
-};
 /* *INDENT-ON* */
 
 VLIB_NODE_FN (esp6_encrypt_tun_node) (vlib_main_t * vm,
@@ -1222,25 +1196,11 @@ VLIB_REGISTER_NODE (esp6_encrypt_tun_node) = {
   .next_nodes = {
     [ESP_ENCRYPT_NEXT_DROP] = "ip6-drop",
     [ESP_ENCRYPT_NEXT_HANDOFF] = "esp6-encrypt-tun-handoff",
-    [ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT] = "error-drop",
     [ESP_ENCRYPT_NEXT_PENDING] = "esp-encrypt-pending",
+    [ESP_ENCRYPT_NEXT_INTERFACE_OUTPUT] = "adj-midchain-tx",
   },
 };
 
-VNET_FEATURE_INIT (esp6_encrypt_tun_feat_node, static) =
-{
-  .arc_name = "ip6-output",
-  .node_name = "esp6-encrypt-tun",
-  .runs_before = VNET_FEATURES ("adj-midchain-tx"),
-};
-
-VNET_FEATURE_INIT (esp4o6_encrypt_tun_feat_node, static) =
-{
-  .arc_name = "ip4-output",
-  .node_name = "esp6-encrypt-tun",
-  .runs_before = VNET_FEATURES ("adj-midchain-tx"),
-};
-
 /* *INDENT-ON* */
 
 VLIB_NODE_FN (esp6_encrypt_tun_post_node) (vlib_main_t * vm,
@@ -1300,7 +1260,6 @@ esp_no_crypto_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 		      vlib_frame_t * frame)
 {
   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
-  u16 nexts[VLIB_FRAME_SIZE], *next = nexts;
   u32 *from = vlib_frame_vector_args (frame);
   u32 n_left = frame->n_vectors;
 
@@ -1308,14 +1267,11 @@ esp_no_crypto_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 
   while (n_left > 0)
     {
-      u32 next0;
       u32 sa_index0;
 
       /* packets are always going to be dropped, but get the sa_index */
-      sa_index0 = *(u32 *) vnet_feature_next_with_data (&next0, b[0],
-							sizeof (sa_index0));
-
-      next[0] = ESP_NO_CRYPTO_NEXT_DROP;
+      sa_index0 = ipsec_tun_protect_get_sa_out
+	(vnet_buffer (b[0])->ip.adj_index[VLIB_TX]);
 
       if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
 	{
@@ -1325,14 +1281,15 @@ esp_no_crypto_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	}
 
       n_left -= 1;
-      next += 1;
       b += 1;
     }
 
   vlib_node_increment_counter (vm, node->node_index,
 			       ESP_NO_CRYPTO_ERROR_RX_PKTS, frame->n_vectors);
 
-  vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
+  vlib_buffer_enqueue_to_single_next (vm, node, from,
+				      ESP_NO_CRYPTO_NEXT_DROP,
+				      frame->n_vectors);
 
   return frame->n_vectors;
 }
@@ -1358,13 +1315,6 @@ VLIB_REGISTER_NODE (esp4_no_crypto_tun_node) =
   },
 };
 
-VNET_FEATURE_INIT (esp4_no_crypto_tun_feat_node, static) =
-{
-  .arc_name = "ip4-output",
-  .node_name = "esp4-no-crypto",
-  .runs_before = VNET_FEATURES ("adj-midchain-tx"),
-};
-
 VLIB_NODE_FN (esp6_no_crypto_tun_node) (vlib_main_t * vm,
 					vlib_node_runtime_t * node,
 					vlib_frame_t * from_frame)
@@ -1385,13 +1335,6 @@ VLIB_REGISTER_NODE (esp6_no_crypto_tun_node) =
     [ESP_NO_CRYPTO_NEXT_DROP] = "ip6-drop",
   },
 };
-
-VNET_FEATURE_INIT (esp6_no_crypto_tun_feat_node, static) =
-{
-  .arc_name = "ip6-output",
-  .node_name = "esp6-no-crypto",
-  .runs_before = VNET_FEATURES ("adj-midchain-tx"),
-};
 /* *INDENT-ON* */
 
 VLIB_NODE_FN (esp_encrypt_pending_node) (vlib_main_t * vm,
diff --git a/src/vnet/ipsec/ipsec.c b/src/vnet/ipsec/ipsec.c
index 6b31926be4f..95e322e87a6 100644
--- a/src/vnet/ipsec/ipsec.c
+++ b/src/vnet/ipsec/ipsec.c
@@ -124,17 +124,6 @@ ipsec_add_node (vlib_main_t * vm, const char *node_name,
   *out_next_index = vlib_node_add_next (vm, prev_node->index, node->index);
 }
 
-void
-ipsec_add_feature (const char *arc_name,
-		   const char *node_name, u32 * out_feature_index)
-{
-  u8 arc;
-
-  arc = vnet_get_feature_arc_index (arc_name);
-  ASSERT (arc != (u8) ~ 0);
-  *out_feature_index = vnet_get_feature_index (arc, node_name);
-}
-
 u32
 ipsec_register_ah_backend (vlib_main_t * vm, ipsec_main_t * im,
 			   const char *name,
@@ -198,14 +187,10 @@ ipsec_register_esp_backend (vlib_main_t * vm, ipsec_main_t * im,
 		  &b->esp6_decrypt_tun_node_index,
 		  &b->esp6_decrypt_tun_next_index);
 
-  ipsec_add_feature ("ip4-output", esp4_encrypt_node_tun_name,
-		     &b->esp44_encrypt_tun_feature_index);
-  ipsec_add_feature ("ip4-output", esp6_encrypt_node_tun_name,
-		     &b->esp46_encrypt_tun_feature_index);
-  ipsec_add_feature ("ip6-output", esp6_encrypt_node_tun_name,
-		     &b->esp66_encrypt_tun_feature_index);
-  ipsec_add_feature ("ip6-output", esp4_encrypt_node_tun_name,
-		     &b->esp64_encrypt_tun_feature_index);
+  b->esp6_encrypt_tun_node_index =
+    vlib_get_node_by_name (vm, (u8 *) esp6_encrypt_node_tun_name)->index;
+  b->esp4_encrypt_tun_node_index =
+    vlib_get_node_by_name (vm, (u8 *) esp4_encrypt_node_tun_name)->index;
 
   b->check_support_cb = esp_check_support_cb;
   b->add_del_sa_sess_cb = esp_add_del_sa_sess_cb;
@@ -284,11 +269,8 @@ ipsec_select_esp_backend (ipsec_main_t * im, u32 backend_idx)
   im->esp4_decrypt_tun_next_index = b->esp4_decrypt_tun_next_index;
   im->esp6_decrypt_tun_node_index = b->esp6_decrypt_tun_node_index;
   im->esp6_decrypt_tun_next_index = b->esp6_decrypt_tun_next_index;
-
-  im->esp44_encrypt_tun_feature_index = b->esp44_encrypt_tun_feature_index;
-  im->esp64_encrypt_tun_feature_index = b->esp64_encrypt_tun_feature_index;
-  im->esp46_encrypt_tun_feature_index = b->esp46_encrypt_tun_feature_index;
-  im->esp66_encrypt_tun_feature_index = b->esp66_encrypt_tun_feature_index;
+  im->esp4_encrypt_tun_node_index = b->esp4_encrypt_tun_node_index;
+  im->esp6_encrypt_tun_node_index = b->esp6_encrypt_tun_node_index;
 
   if (b->enable_disable_cb)
     {
diff --git a/src/vnet/ipsec/ipsec.h b/src/vnet/ipsec/ipsec.h
index 712e16dab4c..7646ffb2ddd 100644
--- a/src/vnet/ipsec/ipsec.h
+++ b/src/vnet/ipsec/ipsec.h
@@ -66,12 +66,10 @@ typedef struct
   u32 esp6_decrypt_next_index;
   u32 esp4_decrypt_tun_node_index;
   u32 esp4_decrypt_tun_next_index;
+  u32 esp4_encrypt_tun_node_index;
   u32 esp6_decrypt_tun_node_index;
   u32 esp6_decrypt_tun_next_index;
-  u32 esp44_encrypt_tun_feature_index;
-  u32 esp46_encrypt_tun_feature_index;
-  u32 esp66_encrypt_tun_feature_index;
-  u32 esp64_encrypt_tun_feature_index;
+  u32 esp6_encrypt_tun_node_index;
 } ipsec_esp_backend_t;
 
 typedef struct
@@ -132,11 +130,13 @@ typedef struct
   u32 esp4_encrypt_node_index;
   u32 esp4_decrypt_node_index;
   u32 esp4_decrypt_tun_node_index;
+  u32 esp4_encrypt_tun_node_index;
   u32 ah4_encrypt_node_index;
   u32 ah4_decrypt_node_index;
   u32 esp6_encrypt_node_index;
   u32 esp6_decrypt_node_index;
   u32 esp6_decrypt_tun_node_index;
+  u32 esp6_encrypt_tun_node_index;
   u32 ah6_encrypt_node_index;
   u32 ah6_decrypt_node_index;
   /* next node indices */
@@ -151,15 +151,13 @@ typedef struct
   u32 ah6_encrypt_next_index;
   u32 ah6_decrypt_next_index;
 
-  /* tun encrypt arcs and feature nodes */
-  u32 esp44_encrypt_tun_feature_index;
-  u32 esp64_encrypt_tun_feature_index;
-  u32 esp46_encrypt_tun_feature_index;
-  u32 esp66_encrypt_tun_feature_index;
-
   /* tun nodes to drop packets when no crypto alg set on outbound SA */
-  u32 esp4_no_crypto_tun_feature_index;
-  u32 esp6_no_crypto_tun_feature_index;
+  u32 esp4_no_crypto_tun_node_index;
+  u32 esp6_no_crypto_tun_node_index;
+
+  /* tun nodes for encrypt on L2 interfaces */
+  u32 esp4_encrypt_l2_tun_node_index;
+  u32 esp6_encrypt_l2_tun_node_index;
 
   /* pool of ah backends */
   ipsec_ah_backend_t *ah_backends;
@@ -278,6 +276,7 @@ int ipsec_select_ah_backend (ipsec_main_t * im, u32 ah_backend_idx);
 int ipsec_select_esp_backend (ipsec_main_t * im, u32 esp_backend_idx);
 
 clib_error_t *ipsec_rsc_in_use (ipsec_main_t * im);
+void ipsec_set_async_mode (u32 is_enabled);
 
 always_inline ipsec_sa_t *
 ipsec_sa_get (u32 sa_index)
@@ -285,11 +284,6 @@ ipsec_sa_get (u32 sa_index)
   return (pool_elt_at_index (ipsec_main.sad, sa_index));
 }
 
-void ipsec_add_feature (const char *arc_name, const char *node_name,
-			u32 * out_feature_index);
-
-void ipsec_set_async_mode (u32 is_enabled);
-
 #endif /* __IPSEC_H__ */
 
 /*
diff --git a/src/vnet/ipsec/ipsec_tun.c b/src/vnet/ipsec/ipsec_tun.c
index 23598b7b085..a93e66a8775 100644
--- a/src/vnet/ipsec/ipsec_tun.c
+++ b/src/vnet/ipsec/ipsec_tun.c
@@ -19,6 +19,7 @@
 #include <vnet/ipsec/esp.h>
 #include <vnet/udp/udp.h>
 #include <vnet/adj/adj_delegate.h>
+#include <vnet/adj/adj_midchain.h>
 #include <vnet/teib/teib.h>
 
 /**
@@ -118,15 +119,6 @@ ipsec_tun_unregister_nodes (ip_address_family_t af)
     }
 }
 
-static void
-ipsec_tun_protect_add_adj (adj_index_t ai, index_t sai)
-{
-  vec_validate_init_empty (ipsec_tun_protect_sa_by_adj_index, ai,
-			   INDEX_INVALID);
-
-  ipsec_tun_protect_sa_by_adj_index[ai] = sai;
-}
-
 static inline const ipsec_tun_protect_t *
 ipsec_tun_protect_from_const_base (const adj_delegate_t * ad)
 {
@@ -135,60 +127,51 @@ ipsec_tun_protect_from_const_base (const adj_delegate_t * ad)
   return (pool_elt_at_index (ipsec_tun_protect_pool, ad->ad_index));
 }
 
+static u32
+ipsec_tun_protect_get_adj_next (const ipsec_tun_protect_t * itp)
+{
+  ipsec_main_t *im;
+  ipsec_sa_t *sa;
+  bool is_ip4;
+  u32 next;
+
+  is_ip4 = ip46_address_is_ip4 (&itp->itp_tun.src);
+  sa = ipsec_sa_get (itp->itp_out_sa);
+  im = &ipsec_main;
+
+  if (sa->crypto_alg == IPSEC_CRYPTO_ALG_NONE &&
+      sa->integ_alg == IPSEC_INTEG_ALG_NONE)
+    next = (is_ip4 ?
+	    im->esp4_no_crypto_tun_node_index :
+	    im->esp6_no_crypto_tun_node_index);
+  else if (itp->itp_flags & IPSEC_PROTECT_L2)
+    next = (is_ip4 ?
+	    im->esp4_encrypt_l2_tun_node_index :
+	    im->esp6_encrypt_l2_tun_node_index);
+  else
+    next = (is_ip4 ?
+	    im->esp4_encrypt_tun_node_index :
+	    im->esp6_encrypt_tun_node_index);
+
+  return (next);
+}
+
 static void
-ipsec_tun_protect_feature_set (ipsec_tun_protect_t * itp, u8 enable)
+ipsec_tun_protect_add_adj (adj_index_t ai, const ipsec_tun_protect_t * itp)
 {
-  ITP_DBG2 ("%s on %U", (enable ? "enable" : "disable"),
-	    format_vnet_sw_if_index_name, vnet_get_main (),
-	    itp->itp_sw_if_index);
+  vec_validate_init_empty (ipsec_tun_protect_sa_by_adj_index, ai,
+			   INDEX_INVALID);
 
-  if (itp->itp_flags & IPSEC_PROTECT_L2)
+  if (NULL == itp)
     {
-      /* l2-GRE only supported by the vnet ipsec code */
-      vnet_feature_enable_disable ("ethernet-output",
-				   (ip46_address_is_ip4 (&itp->itp_tun.src) ?
-				    "esp4-encrypt-tun" :
-				    "esp6-encrypt-tun"),
-				   itp->itp_sw_if_index, enable, NULL, 0);
+      ipsec_tun_protect_sa_by_adj_index[ai] = INDEX_INVALID;
+      adj_nbr_midchain_reset_next_node (ai);
     }
   else
     {
-      u32 fi4, fi6, sai;
-      ipsec_main_t *im;
-      ipsec_sa_t *sa;
-
-      im = &ipsec_main;
-      sai = itp->itp_out_sa;
-      sa = ipsec_sa_get (sai);
-
-      if (sa->crypto_alg == IPSEC_CRYPTO_ALG_NONE &&
-	  sa->integ_alg == IPSEC_INTEG_ALG_NONE)
-	{
-	  fi4 = im->esp4_no_crypto_tun_feature_index;
-	  fi6 = im->esp6_no_crypto_tun_feature_index;
-	}
-      else
-	{
-	  if (ip46_address_is_ip4 (&itp->itp_tun.src))
-	    {
-	      /* tunnel destination is v4 so we need the Xo4 indexes */
-	      fi4 = im->esp44_encrypt_tun_feature_index;
-	      fi6 = im->esp64_encrypt_tun_feature_index;
-	    }
-	  else
-	    {
-	      /* tunnel destination is v6 so we need the Xo6 indexes */
-	      fi4 = im->esp46_encrypt_tun_feature_index;
-	      fi6 = im->esp66_encrypt_tun_feature_index;
-	    }
-	}
-
-      vnet_feature_enable_disable_with_index
-	(vnet_get_feature_arc_index ("ip4-output"),
-	 fi4, itp->itp_sw_if_index, enable, NULL, 0);
-      vnet_feature_enable_disable_with_index
-	(vnet_get_feature_arc_index ("ip6-output"),
-	 fi6, itp->itp_sw_if_index, enable, NULL, 0);
+      ipsec_tun_protect_sa_by_adj_index[ai] = itp->itp_out_sa;
+      adj_nbr_midchain_update_next_node
+	(ai, ipsec_tun_protect_get_adj_next (itp));
     }
 }
 
@@ -266,7 +249,7 @@ ipsec_tun_protect_adj_add (adj_index_t ai, void *arg)
   ipsec_tun_protect_t *itp = arg;
   adj_delegate_add (adj_get (ai), ipsec_tun_adj_delegate_type,
 		    itp - ipsec_tun_protect_pool);
-  ipsec_tun_protect_add_adj (ai, itp->itp_out_sa);
+  ipsec_tun_protect_add_adj (ai, itp);
 
   return (ADJ_WALK_RC_CONTINUE);
 }
@@ -291,7 +274,7 @@ ipsec_tun_protect_tx_db_add (ipsec_tun_protect_t * itp)
     {
       if (INDEX_INVALID == idi->id_itp)
 	{
-	  ipsec_tun_protect_feature_set (itp, 1);
+	  // ipsec_tun_protect_feature_set (itp, 1);
 	}
       idi->id_itp = itp - ipsec_tun_protect_pool;
 
@@ -309,7 +292,7 @@ ipsec_tun_protect_tx_db_add (ipsec_tun_protect_t * itp)
 	   * enable the encrypt feature for egress if this is the first addition
 	   * on this interface
 	   */
-	  ipsec_tun_protect_feature_set (itp, 1);
+	  // ipsec_tun_protect_feature_set (itp, 1);
 	}
 
       hash_set_mem (idi->id_hash, itp->itp_key, itp - ipsec_tun_protect_pool);
@@ -337,31 +320,31 @@ ipsec_tun_protect_rx_db_remove (ipsec_main_t * im,
   /* *INDENT-OFF* */
   FOR_EACH_IPSEC_PROTECT_INPUT_SA(itp, sa,
   ({
-      if (ip46_address_is_ip4 (&itp->itp_crypto.dst))
-        {
-          ipsec4_tunnel_key_t key = {
-            .remote_ip = itp->itp_crypto.dst.ip4,
-            .spi = clib_host_to_net_u32 (sa->spi),
-          };
-          if (hash_get(im->tun4_protect_by_key, key.as_u64))
-            {
-              hash_unset (im->tun4_protect_by_key, key.as_u64);
-              ipsec_tun_unregister_nodes(AF_IP4);
-            }
-        }
-      else
-        {
-          ipsec6_tunnel_key_t key = {
-            .remote_ip = itp->itp_crypto.dst.ip6,
-            .spi = clib_host_to_net_u32 (sa->spi),
-          };
-          if (hash_get_mem(im->tun6_protect_by_key, &key))
-            {
-              hash_unset_mem_free (&im->tun6_protect_by_key, &key);
-              ipsec_tun_unregister_nodes(AF_IP6);
-            }
-        }
-  }))
+    if (ip46_address_is_ip4 (&itp->itp_crypto.dst))
+      {
+        ipsec4_tunnel_key_t key = {
+          .remote_ip = itp->itp_crypto.dst.ip4,
+          .spi = clib_host_to_net_u32 (sa->spi),
+        };
+        if (hash_get(im->tun4_protect_by_key, key.as_u64))
+          {
+            hash_unset (im->tun4_protect_by_key, key.as_u64);
+            ipsec_tun_unregister_nodes(AF_IP4);
+          }
+      }
+    else
+      {
+        ipsec6_tunnel_key_t key = {
+          .remote_ip = itp->itp_crypto.dst.ip6,
+          .spi = clib_host_to_net_u32 (sa->spi),
+        };
+        if (hash_get_mem(im->tun6_protect_by_key, &key))
+          {
+            hash_unset_mem_free (&im->tun6_protect_by_key, &key);
+            ipsec_tun_unregister_nodes(AF_IP6);
+          }
+      }
+  }));
   /* *INDENT-ON* */
 }
 
@@ -369,7 +352,7 @@ static adj_walk_rc_t
 ipsec_tun_protect_adj_remove (adj_index_t ai, void *arg)
 {
   adj_delegate_remove (ai, ipsec_tun_adj_delegate_type);
-  ipsec_tun_protect_add_adj (ai, INDEX_INVALID);
+  ipsec_tun_protect_add_adj (ai, NULL);
 
   return (ADJ_WALK_RC_CONTINUE);
 }
@@ -386,7 +369,7 @@ ipsec_tun_protect_tx_db_remove (ipsec_tun_protect_t * itp)
 
   if (vnet_sw_interface_is_p2p (vnet_get_main (), itp->itp_sw_if_index))
     {
-      ipsec_tun_protect_feature_set (itp, 0);
+      // ipsec_tun_protect_feature_set (itp, 0);
       idi->id_itp = INDEX_INVALID;
 
       FOR_EACH_FIB_IP_PROTOCOL (nh_proto)
@@ -402,7 +385,7 @@ ipsec_tun_protect_tx_db_remove (ipsec_tun_protect_t * itp)
 
       if (0 == hash_elts (idi->id_hash))
 	{
-	  ipsec_tun_protect_feature_set (itp, 0);
+	  // ipsec_tun_protect_feature_set (itp, 0);
 	  hash_free (idi->id_hash);
 	  idi->id_hash = NULL;
 	}
@@ -817,11 +800,18 @@ static void
 ipsec_tun_protect_adj_delegate_adj_deleted (adj_delegate_t * ad)
 {
   /* remove our delegate */
-  ipsec_tun_protect_add_adj (ad->ad_adj_index, INDEX_INVALID);
+  ipsec_tun_protect_add_adj (ad->ad_adj_index, NULL);
   adj_delegate_remove (ad->ad_adj_index, ipsec_tun_adj_delegate_type);
 }
 
 static void
+ipsec_tun_protect_adj_delegate_adj_modified (adj_delegate_t * ad)
+{
+  ipsec_tun_protect_add_adj (ad->ad_adj_index,
+			     ipsec_tun_protect_get (ad->ad_index));
+}
+
+static void
 ipsec_tun_protect_adj_delegate_adj_created (adj_index_t ai)
 {
   /* add our delegate if there is protection for this neighbour */
@@ -829,11 +819,11 @@ ipsec_tun_protect_adj_delegate_adj_created (adj_index_t ai)
   ip_adjacency_t *adj;
   index_t itpi;
 
-  adj = adj_get (ai);
-
-  if (adj->lookup_next_index != IP_LOOKUP_NEXT_MIDCHAIN)
+  if (!adj_is_midchain (ai))
     return;
 
+  adj = adj_get (ai);
+
   ip_address_from_46 (&adj->sub_type.midchain.next_hop,
 		      adj->ia_nh_proto, &ip);
 
@@ -845,7 +835,7 @@ ipsec_tun_protect_adj_delegate_adj_created (adj_index_t ai)
 
       itp = ipsec_tun_protect_get (itpi);
       adj_delegate_add (adj_get (ai), ipsec_tun_adj_delegate_type, itpi);
-      ipsec_tun_protect_add_adj (ai, itp->itp_out_sa);
+      ipsec_tun_protect_add_adj (ai, itp);
     }
 }
 
@@ -919,6 +909,7 @@ ipsec_tun_teib_entry_deleted (const teib_entry_t * ne)
 const static adj_delegate_vft_t ipsec_tun_adj_delegate_vft = {
   .adv_adj_deleted = ipsec_tun_protect_adj_delegate_adj_deleted,
   .adv_adj_created = ipsec_tun_protect_adj_delegate_adj_created,
+  .adv_adj_modified = ipsec_tun_protect_adj_delegate_adj_modified,
   .adv_format = ipsec_tun_protect_adj_delegate_format,
 };
 
@@ -927,6 +918,7 @@ const static teib_vft_t ipsec_tun_teib_vft = {
   .nv_deleted = ipsec_tun_teib_entry_deleted,
 };
 
+
 clib_error_t *
 ipsec_tunnel_protect_init (vlib_main_t * vm)
 {
@@ -939,10 +931,14 @@ ipsec_tunnel_protect_init (vlib_main_t * vm)
   im->tun4_protect_by_key = hash_create (0, sizeof (u64));
 
   /* set up feature nodes to drop outbound packets with no crypto alg set */
-  ipsec_add_feature ("ip4-output", "esp4-no-crypto",
-		     &im->esp4_no_crypto_tun_feature_index);
-  ipsec_add_feature ("ip6-output", "esp6-no-crypto",
-		     &im->esp6_no_crypto_tun_feature_index);
+  im->esp4_no_crypto_tun_node_index =
+    vlib_get_node_by_name (vm, (u8 *) "esp4-no-crypto")->index;
+  im->esp6_no_crypto_tun_node_index =
+    vlib_get_node_by_name (vm, (u8 *) "esp6-no-crypto")->index;
+  im->esp6_encrypt_l2_tun_node_index =
+    vlib_get_node_by_name (vm, (u8 *) "esp6-encrypt-tun")->index;
+  im->esp4_encrypt_l2_tun_node_index =
+    vlib_get_node_by_name (vm, (u8 *) "esp4-encrypt-tun")->index;
 
   ipsec_tun_adj_delegate_type =
     adj_delegate_register_new_type (&ipsec_tun_adj_delegate_vft);