ipsec: IPSec protection for multi-point tunnel interfaces

Type: feature

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: Iaba2ab11bfaa1c8db4023434e3043ac39500f938

8 files changed, 556 insertions, 141 deletions

diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index 2c4da5dafa8..7df537a5555 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -23,6 +23,7 @@
 #include <vnet/crypto/crypto.h>
 
 #include <vnet/ipsec/ipsec.h>
+#include <vnet/ipsec/ipsec_tun.h>
 #include <vnet/ipsec/esp.h>
 
 #define foreach_esp_encrypt_next                   \
@@ -319,13 +320,13 @@ esp_encrypt_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
       if (is_tun)
 	{
 	  /* we are on a ipsec tunnel's feature arc */
-	  u32 next0;
+	  u32 next0 = 0;
 	  config_index = b[0]->current_config_index;
-	  sa_index0 = *(u32 *) vnet_feature_next_with_data (&next0, b[0],
-							    sizeof
-							    (sa_index0));
-	  vnet_buffer (b[0])->ipsec.sad_index = sa_index0;
+	  vnet_feature_next (&next0, b[0]);
 	  next[0] = next0;
+	  vnet_buffer (b[0])->ipsec.sad_index =
+	    sa_index0 = ipsec_tun_protect_get_sa_out
+	    (vnet_buffer (b[0])->ip.adj_index[VLIB_TX]);
 	}
       else
 	sa_index0 = vnet_buffer (b[0])->ipsec.sad_index;
diff --git a/src/vnet/ipsec/ipsec.api b/src/vnet/ipsec/ipsec.api
index 6d34d056003..b5027f60301 100644
--- a/src/vnet/ipsec/ipsec.api
+++ b/src/vnet/ipsec/ipsec.api
@@ -234,12 +234,16 @@ define ipsec_sad_entry_add_del_reply
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
     @param sw_id_index - Tunnel interface to protect
+    @param nh - The peer/next-hop on the tunnel to which the traffic
+                should be protected. For a P2P interface set this to the
+                all 0s address.
     @param sa_in - The ID [set] of inbound SAs
     @param sa_out - The ID of outbound SA
 */
 typedef ipsec_tunnel_protect
 {
   vl_api_interface_index_t sw_if_index;
+  vl_api_address_t nh;
   u32 sa_out;
   u8 n_sa_in;
   u32 sa_in[n_sa_in];
@@ -259,6 +263,7 @@ autoreply define ipsec_tunnel_protect_del
   u32 context;
 
   vl_api_interface_index_t sw_if_index;
+  vl_api_address_t nh;
 };
 
 /**
diff --git a/src/vnet/ipsec/ipsec_api.c b/src/vnet/ipsec/ipsec_api.c
index a80c60489a4..c7ce3ef83d5 100644
--- a/src/vnet/ipsec/ipsec_api.c
+++ b/src/vnet/ipsec/ipsec_api.c
@@ -116,6 +116,7 @@ static void vl_api_ipsec_tunnel_protect_update_t_handler
   vlib_main_t *vm __attribute__ ((unused)) = vlib_get_main ();
   vl_api_ipsec_tunnel_protect_update_reply_t *rmp;
   u32 sw_if_index, ii, *sa_ins = NULL;
+  ip_address_t nh;
   int rv;
 
   sw_if_index = ntohl (mp->tunnel.sw_if_index);
@@ -127,7 +128,9 @@ static void vl_api_ipsec_tunnel_protect_update_t_handler
   for (ii = 0; ii < mp->tunnel.n_sa_in; ii++)
     vec_add1 (sa_ins, ntohl (mp->tunnel.sa_in[ii]));
 
-  rv = ipsec_tun_protect_update (sw_if_index,
+  ip_address_decode2 (&mp->tunnel.nh, &nh);
+
+  rv = ipsec_tun_protect_update (sw_if_index, &nh,
 				 ntohl (mp->tunnel.sa_out), sa_ins);
 #else
   rv = VNET_API_ERROR_UNIMPLEMENTED;
@@ -143,15 +146,17 @@ static void vl_api_ipsec_tunnel_protect_del_t_handler
 {
   vlib_main_t *vm __attribute__ ((unused)) = vlib_get_main ();
   vl_api_ipsec_tunnel_protect_del_reply_t *rmp;
-  int rv;
+  ip_address_t nh;
   u32 sw_if_index;
+  int rv;
 
   sw_if_index = ntohl (mp->sw_if_index);
 
   VALIDATE_SW_IF_INDEX (mp);
 
 #if WITH_LIBSSL > 0
-  rv = ipsec_tun_protect_del (sw_if_index);
+  ip_address_decode2 (&mp->nh, &nh);
+  rv = ipsec_tun_protect_del (sw_if_index, &nh);
 #else
   rv = VNET_API_ERROR_UNIMPLEMENTED;
 #endif
@@ -177,13 +182,13 @@ send_ipsec_tunnel_protect_details (index_t itpi, void *arg)
 
   itp = ipsec_tun_protect_get (itpi);
 
-
   mp = vl_msg_api_alloc (sizeof (*mp) + (sizeof (u32) * itp->itp_n_sa_in));
   clib_memset (mp, 0, sizeof (*mp));
   mp->_vl_msg_id = ntohs (VL_API_IPSEC_TUNNEL_PROTECT_DETAILS);
   mp->context = ctx->context;
 
   mp->tun.sw_if_index = htonl (itp->itp_sw_if_index);
+  ip_address_encode2 (itp->itp_key, &mp->tun.nh);
 
   mp->tun.sa_out = htonl (itp->itp_out_sa);
   mp->tun.n_sa_in = itp->itp_n_sa_in;
@@ -224,12 +229,8 @@ vl_api_ipsec_tunnel_protect_dump_t_handler (vl_api_ipsec_tunnel_protect_dump_t
     }
   else
     {
-      index_t itpi;
-
-      itpi = ipsec_tun_protect_find (sw_if_index);
-
-      if (INDEX_INVALID != itpi)
-	send_ipsec_tunnel_protect_details (itpi, &ctx);
+      ipsec_tun_protect_walk_itf (sw_if_index,
+				  send_ipsec_tunnel_protect_details, &ctx);
     }
 #else
   clib_warning ("unimplemented");
@@ -680,7 +681,7 @@ vl_api_ipsec_tunnel_if_add_del_t_handler (vl_api_ipsec_tunnel_if_add_del_t *
       if (rv)
 	goto done;
 
-      rv = ipsec_tun_protect_update_one (sw_if_index,
+      rv = ipsec_tun_protect_update_one (sw_if_index, NULL,
 					 ipsec_tun_mk_output_sa_id
 					 (sw_if_index),
 					 ipsec_tun_mk_input_sa_id
@@ -711,7 +712,7 @@ vl_api_ipsec_tunnel_if_add_del_t_handler (vl_api_ipsec_tunnel_if_add_del_t *
 
       if (NULL != t)
 	{
-	  rv = ipsec_tun_protect_del (t->sw_if_index);
+	  rv = ipsec_tun_protect_del (t->sw_if_index, NULL);
 	  ipip_del_tunnel (t->sw_if_index);
 	}
       else
@@ -859,10 +860,10 @@ vl_api_ipsec_tunnel_if_set_sa_t_handler (vl_api_ipsec_tunnel_if_set_sa_t * mp)
   VALIDATE_SW_IF_INDEX(mp);
 
   if (mp->is_outbound)
-    rv = ipsec_tun_protect_update_out (ntohl (mp->sw_if_index),
+    rv = ipsec_tun_protect_update_out (ntohl (mp->sw_if_index), NULL,
                                        ntohl (mp->sa_id));
   else
-    rv = ipsec_tun_protect_update_in (ntohl (mp->sw_if_index),
+    rv = ipsec_tun_protect_update_in (ntohl (mp->sw_if_index), NULL,
                                        ntohl (mp->sa_id));
 
 #else
diff --git a/src/vnet/ipsec/ipsec_cli.c b/src/vnet/ipsec/ipsec_cli.c
index b054155a45e..1ab8bd99db3 100644
--- a/src/vnet/ipsec/ipsec_cli.c
+++ b/src/vnet/ipsec/ipsec_cli.c
@@ -391,7 +391,7 @@ ipsec_spd_bindings_show_all (vlib_main_t * vm, ipsec_main_t * im)
 static walk_rc_t
 ipsec_tun_protect_show_one (index_t itpi, void *ctx)
 {
-  vlib_cli_output (ctx, "%U", format_ipsec_tun_protect, itpi);
+  vlib_cli_output (ctx, "%U", format_ipsec_tun_protect_index, itpi);
 
   return (WALK_CONTINUE);
 }
@@ -728,6 +728,7 @@ create_ipsec_tunnel_command_fn (vlib_main_t * vm,
   unformat_input_t _line_input, *line_input = &_line_input;
   ip46_address_t local_ip = ip46_address_initializer;
   ip46_address_t remote_ip = ip46_address_initializer;
+  ip_address_t nh = IP_ADDRESS_V4_ALL_0S;
   ipsec_crypto_alg_t crypto_alg;
   ipsec_integ_alg_t integ_alg;
   ipsec_sa_flags_t flags;
@@ -808,6 +809,8 @@ create_ipsec_tunnel_command_fn (vlib_main_t * vm,
 	;
       else if (unformat (line_input, "del"))
 	is_add = 0;
+      else if (unformat (line_input, "nh &U", unformat_ip_address, &nh))
+	;
       else
 	{
 	  error = clib_error_return (0, "unknown input `%U'",
@@ -858,7 +861,7 @@ create_ipsec_tunnel_command_fn (vlib_main_t * vm,
 			       clib_host_to_net_u32 (salt), &remote_ip,
 			       &local_ip, NULL);
       rv |=
-	ipsec_tun_protect_update_one (sw_if_index,
+	ipsec_tun_protect_update_one (sw_if_index, &nh,
 				      ipsec_tun_mk_local_sa_id (sw_if_index),
 				      ipsec_tun_mk_remote_sa_id
 				      (sw_if_index));
@@ -902,6 +905,7 @@ ipsec_tun_protect_cmd (vlib_main_t * vm,
 {
   unformat_input_t _line_input, *line_input = &_line_input;
   u32 sw_if_index, is_del, sa_in, sa_out, *sa_ins = NULL;
+  ip_address_t peer = { };
   vnet_main_t *vnm;
 
   is_del = 0;
@@ -924,13 +928,15 @@ ipsec_tun_protect_cmd (vlib_main_t * vm,
       else if (unformat (line_input, "%U",
 			 unformat_vnet_sw_interface, vnm, &sw_if_index))
 	;
+      else if (unformat (line_input, "%U", unformat_ip_address, &peer))
+	;
       else
 	return (clib_error_return (0, "unknown input '%U'",
 				   format_unformat_error, line_input));
     }
 
   if (!is_del)
-    ipsec_tun_protect_update (sw_if_index, sa_out, sa_ins);
+    ipsec_tun_protect_update (sw_if_index, &peer, sa_out, sa_ins);
 
   unformat_free (line_input);
   return NULL;
diff --git a/src/vnet/ipsec/ipsec_format.c b/src/vnet/ipsec/ipsec_format.c
index 8b9d8c40be1..bf398cb2105 100644
--- a/src/vnet/ipsec/ipsec_format.c
+++ b/src/vnet/ipsec/ipsec_format.c
@@ -337,26 +337,33 @@ done:
 }
 
 u8 *
-format_ipsec_tun_protect (u8 * s, va_list * args)
+format_ipsec_tun_protect_index (u8 * s, va_list * args)
 {
-  u32 itpi = va_arg (*args, u32);
+  u32 itpi = va_arg (*args, index_t);
   ipsec_tun_protect_t *itp;
-  u32 sai;
 
-  if (pool_is_free_index (ipsec_protect_pool, itpi))
-    {
-      s = format (s, "No such tunnel index: %d", itpi);
-      goto done;
-    }
+  if (pool_is_free_index (ipsec_tun_protect_pool, itpi))
+    return (format (s, "No such tunnel index: %d", itpi));
+
+  itp = pool_elt_at_index (ipsec_tun_protect_pool, itpi);
+
+  return (format (s, "%U", format_ipsec_tun_protect, itp));
+}
 
-  itp = pool_elt_at_index (ipsec_protect_pool, itpi);
+
+u8 *
+format_ipsec_tun_protect (u8 * s, va_list * args)
+{
+  ipsec_tun_protect_t *itp = va_arg (*args, ipsec_tun_protect_t *);
+  u32 sai;
 
   s = format (s, "%U", format_vnet_sw_if_index_name,
 	      vnet_get_main (), itp->itp_sw_if_index);
+  if (!ip_address_is_zero (itp->itp_key))
+    s = format (s, ": %U", format_ip_address, itp->itp_key);
   s = format (s, "\n output-sa:");
-  s =
-    format (s, "\n  %U", format_ipsec_sa, itp->itp_out_sa,
-	    IPSEC_FORMAT_BRIEF);
+  s = format (s, "\n  %U", format_ipsec_sa, itp->itp_out_sa,
+	      IPSEC_FORMAT_BRIEF);
 
   s = format (s, "\n input-sa:");
   /* *INDENT-OFF* */
@@ -366,7 +373,6 @@ format_ipsec_tun_protect (u8 * s, va_list * args)
   }));
   /* *INDENT-ON* */
 
-done:
   return (s);
 }
 
diff --git a/src/vnet/ipsec/ipsec_tun.c b/src/vnet/ipsec/ipsec_tun.c
index f6b09d65f2c..769229721f6 100644
--- a/src/vnet/ipsec/ipsec_tun.c
+++ b/src/vnet/ipsec/ipsec_tun.c
@@ -18,29 +18,92 @@
 #include <vnet/ipsec/ipsec_tun.h>
 #include <vnet/ipsec/esp.h>
 #include <vnet/udp/udp.h>
+#include <vnet/adj/adj_delegate.h>
+#include <vnet/teib/teib.h>
+
+/**
+ * The logger
+ */
+vlib_log_class_t ipsec_tun_protect_logger;
 
 /**
  * Pool of tunnel protection objects
  */
-ipsec_tun_protect_t *ipsec_protect_pool;
+ipsec_tun_protect_t *ipsec_tun_protect_pool;
+
+/**
+ * Adj delegate registered type
+ */
+static adj_delegate_type_t ipsec_tun_adj_delegate_type;
+
+/**
+ * Adj index to TX SA mapping
+ */
+index_t *ipsec_tun_protect_sa_by_adj_index;
+
+const ip_address_t IP_ADDR_ALL_0 = IP_ADDRESS_V4_ALL_0S;
 
 /**
- * DB of protected tunnels
+ * The DB of all added per-nh tunnel protectiond
  */
-typedef struct ipsec_protect_db_t_
+typedef struct ipsec_tun_protect_itf_db_t_
+{
+  /** A hash table key'd on IP (4 or 6) address */
+  uword *id_hash;
+  /** If the interface is P2P then there is only one protect
+   * object associated with the auto-adj for each NH proto */
+  index_t id_itp;
+} ipsec_tun_protect_itf_db_t;
+
+typedef struct ipsec_tun_protect_db_t_
 {
-  u32 *tunnels;
-  u32 count;
-} ipsec_protect_db_t;
+  /** Per-interface vector */
+  ipsec_tun_protect_itf_db_t *id_itf;
+} ipsec_tun_protect_db_t;
+
+static ipsec_tun_protect_db_t itp_db;
+
+const static ipsec_tun_protect_itf_db_t IPSEC_TUN_PROTECT_DEFAULT_DB_ENTRY = {
+  .id_itp = INDEX_INVALID,
+};
+
+#define ITP_DBG(_itp, _fmt, _args...)                   \
+{   		          				\
+  vlib_log_debug(ipsec_tun_protect_logger,              \
+                 "[%U]: " _fmt,                         \
+                 format_ipsec_tun_protect,              \
+                 _itp, ##_args);                        \
+}
 
-static ipsec_protect_db_t ipsec_protect_db;
+#define ITP_DBG2(_fmt, _args...)                        \
+{   		          				\
+  vlib_log_debug(ipsec_tun_protect_logger,              \
+                 _fmt, ##_args);                        \
+}
 
 static void
-ipsec_tun_protect_feature_set (ipsec_tun_protect_t * itp, u8 enable)
+ipsec_tun_protect_add_adj (adj_index_t ai, index_t sai)
 {
-  u32 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)
+{
+  if (ad == NULL)
+    return (NULL);
+  return (pool_elt_at_index (ipsec_tun_protect_pool, ad->ad_index));
+}
 
-  sai = itp->itp_out_sa;
+static void
+ipsec_tun_protect_feature_set (ipsec_tun_protect_t * itp, u8 enable)
+{
+  ITP_DBG2 ("%s on %U", (enable ? "enable" : "disable"),
+	    format_vnet_sw_if_index_name, vnet_get_main (),
+	    itp->itp_sw_if_index);
 
   if (itp->itp_flags & IPSEC_PROTECT_L2)
     {
@@ -49,16 +112,16 @@ ipsec_tun_protect_feature_set (ipsec_tun_protect_t * itp, u8 enable)
 				   (ip46_address_is_ip4 (&itp->itp_tun.src) ?
 				    "esp4-encrypt-tun" :
 				    "esp6-encrypt-tun"),
-				   itp->itp_sw_if_index, enable,
-				   &sai, sizeof (sai));
+				   itp->itp_sw_if_index, enable, NULL, 0);
     }
   else
     {
+      u32 fi4, fi6, sai;
       ipsec_main_t *im;
       ipsec_sa_t *sa;
-      u32 fi4, fi6;
 
       im = &ipsec_main;
+      sai = itp->itp_out_sa;
       sa = ipsec_sa_get (sai);
 
       if (sa->crypto_alg == IPSEC_CRYPTO_ALG_NONE &&
@@ -85,26 +148,52 @@ ipsec_tun_protect_feature_set (ipsec_tun_protect_t * itp, u8 enable)
 
       vnet_feature_enable_disable_with_index
 	(vnet_get_feature_arc_index ("ip4-output"),
-	 fi4, itp->itp_sw_if_index, enable, &sai, sizeof (sai));
+	 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, &sai, sizeof (sai));
+	 fi6, itp->itp_sw_if_index, enable, NULL, 0);
+    }
+}
+
+static index_t
+ipsec_tun_protect_find (u32 sw_if_index, const ip_address_t * nh)
+{
+  ipsec_tun_protect_itf_db_t *idi;
+  uword *p;
+
+  if (vec_len (itp_db.id_itf) <= sw_if_index)
+    return INDEX_INVALID;
+
+  if (vnet_sw_interface_is_p2p (vnet_get_main (), sw_if_index))
+    return (itp_db.id_itf[sw_if_index].id_itp);
+
+  idi = &itp_db.id_itf[sw_if_index];
+  p = hash_get_mem (idi->id_hash, nh);
+
+  if (NULL == p)
+    {
+      return INDEX_INVALID;
     }
+  return (p[0]);
 }
 
 static void
-ipsec_tun_protect_db_add (ipsec_main_t * im, const ipsec_tun_protect_t * itp)
+ipsec_tun_protect_rx_db_add (ipsec_main_t * im,
+			     const ipsec_tun_protect_t * itp)
 {
   const ipsec_sa_t *sa;
   u32 sai;
 
+  if (ip46_address_is_zero (&itp->itp_crypto.dst))
+    return;
+
   /* *INDENT-OFF* */
   FOR_EACH_IPSEC_PROTECT_INPUT_SAI(itp, sai,
   ({
       sa = ipsec_sa_get (sai);
 
       ipsec_tun_lkup_result_t res = {
-        .tun_index = itp - ipsec_protect_pool,
+        .tun_index = itp - ipsec_tun_protect_pool,
         .sa_index = sai,
       };
 
@@ -120,9 +209,13 @@ ipsec_tun_protect_db_add (ipsec_main_t * im, const ipsec_tun_protect_t * itp)
           };
           hash_set (im->tun4_protect_by_key, key.as_u64, res.as_u64);
           if (1 == hash_elts(im->tun4_protect_by_key))
-            udp_register_dst_port (vlib_get_main(),
-                                   UDP_DST_PORT_ipsec,
-                                   ipsec4_tun_input_node.index, 1);
+            {
+              udp_register_dst_port (vlib_get_main(),
+                                     UDP_DST_PORT_ipsec,
+                                     ipsec4_tun_input_node.index, 1);
+              ip4_register_protocol (IP_PROTOCOL_IPSEC_ESP,
+                                     ipsec4_tun_input_node.index);
+            }
         }
       else
         {
@@ -131,14 +224,83 @@ ipsec_tun_protect_db_add (ipsec_main_t * im, const ipsec_tun_protect_t * itp)
             .spi = clib_host_to_net_u32 (sa->spi),
           };
           hash_set_mem_alloc (&im->tun6_protect_by_key, &key, res.as_u64);
+
+          if (1 == hash_elts (im->tun6_protect_by_key))
+            ip6_register_protocol (IP_PROTOCOL_IPSEC_ESP,
+                                   ipsec6_tun_input_node.index);
         }
   }))
   /* *INDENT-ON* */
 }
 
+static adj_walk_rc_t
+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);
+
+  return (ADJ_WALK_RC_CONTINUE);
+}
+
 static void
-ipsec_tun_protect_db_remove (ipsec_main_t * im,
-			     const ipsec_tun_protect_t * itp)
+ipsec_tun_protect_tx_db_add (ipsec_tun_protect_t * itp)
+{
+  /*
+   * add the delegate to the adj
+   */
+  ipsec_tun_protect_itf_db_t *idi;
+  fib_protocol_t nh_proto;
+  ip46_address_t nh;
+
+  vec_validate_init_empty (itp_db.id_itf,
+			   itp->itp_sw_if_index,
+			   IPSEC_TUN_PROTECT_DEFAULT_DB_ENTRY);
+
+  idi = &itp_db.id_itf[itp->itp_sw_if_index];
+
+  if (vnet_sw_interface_is_p2p (vnet_get_main (), itp->itp_sw_if_index))
+    {
+      if (INDEX_INVALID == idi->id_itp)
+	{
+	  ipsec_tun_protect_feature_set (itp, 1);
+	}
+      idi->id_itp = itp - ipsec_tun_protect_pool;
+
+      FOR_EACH_FIB_IP_PROTOCOL (nh_proto)
+	adj_nbr_walk (itp->itp_sw_if_index,
+		      nh_proto, ipsec_tun_protect_adj_add, itp);
+    }
+  else
+    {
+      if (NULL == idi->id_hash)
+	{
+	  idi->id_hash =
+	    hash_create_mem (0, sizeof (ip_address_t), sizeof (uword));
+	  /*
+	   * enable the encrypt feature for egress if this is the first addition
+	   * on this interface
+	   */
+	  ipsec_tun_protect_feature_set (itp, 1);
+	}
+
+      hash_set_mem (idi->id_hash, itp->itp_key, itp - ipsec_tun_protect_pool);
+
+      /*
+       * walk all the adjs with the same nh on this interface
+       * to associate them with this protection
+       */
+      nh_proto = ip_address_to_46 (itp->itp_key, &nh);
+
+      adj_nbr_walk_nh (itp->itp_sw_if_index,
+		       nh_proto, &nh, ipsec_tun_protect_adj_add, itp);
+    }
+}
+
+static void
+ipsec_tun_protect_rx_db_remove (ipsec_main_t * im,
+				const ipsec_tun_protect_t * itp)
 {
   const ipsec_sa_t *sa;
 
@@ -169,26 +331,56 @@ ipsec_tun_protect_db_remove (ipsec_main_t * im,
   /* *INDENT-ON* */
 }
 
+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);
+
+  return (ADJ_WALK_RC_CONTINUE);
+}
+
 static void
-ipsec_tun_protect_config (ipsec_main_t * im,
-			  ipsec_tun_protect_t * itp, u32 sa_out, u32 * sas_in)
+ipsec_tun_protect_tx_db_remove (ipsec_tun_protect_t * itp)
 {
-  ipsec_sa_t *sa;
-  index_t sai;
-  u32 ii;
+  ipsec_tun_protect_itf_db_t *idi;
+  fib_protocol_t nh_proto;
+  ip46_address_t nh;
 
-  itp->itp_n_sa_in = vec_len (sas_in);
-  for (ii = 0; ii < itp->itp_n_sa_in; ii++)
-    itp->itp_in_sas[ii] = sas_in[ii];
-  itp->itp_out_sa = sa_out;
+  nh_proto = ip_address_to_46 (itp->itp_key, &nh);
+  idi = &itp_db.id_itf[itp->itp_sw_if_index];
 
-  ipsec_sa_lock (itp->itp_out_sa);
+  if (vnet_sw_interface_is_p2p (vnet_get_main (), itp->itp_sw_if_index))
+    {
+      ipsec_tun_protect_feature_set (itp, 0);
+      idi->id_itp = INDEX_INVALID;
+
+      FOR_EACH_FIB_IP_PROTOCOL (nh_proto)
+	adj_nbr_walk (itp->itp_sw_if_index,
+		      nh_proto, ipsec_tun_protect_adj_remove, itp);
+    }
+  else
+    {
+      adj_nbr_walk_nh (itp->itp_sw_if_index,
+		       nh_proto, &nh, ipsec_tun_protect_adj_remove, itp);
+
+      hash_unset_mem (idi->id_hash, itp->itp_key);
+
+      if (0 == hash_elts (idi->id_hash))
+	{
+	  ipsec_tun_protect_feature_set (itp, 0);
+	  hash_free (idi->id_hash);
+	  idi->id_hash = NULL;
+	}
+    }
+}
+
+static void
+ipsec_tun_protect_set_crypto_addr (ipsec_tun_protect_t * itp)
+{
+  ipsec_sa_t *sa;
 
   /* *INDENT-OFF* */
-  FOR_EACH_IPSEC_PROTECT_INPUT_SAI(itp, sai,
-  ({
-    ipsec_sa_lock(sai);
-  }));
   FOR_EACH_IPSEC_PROTECT_INPUT_SA(itp, sa,
   ({
     if (ipsec_sa_is_set_IS_TUNNEL (sa))
@@ -206,16 +398,37 @@ ipsec_tun_protect_config (ipsec_main_t * im,
       }
   }));
   /* *INDENT-ON* */
+}
+
+static void
+ipsec_tun_protect_config (ipsec_main_t * im,
+			  ipsec_tun_protect_t * itp, u32 sa_out, u32 * sas_in)
+{
+  index_t sai;
+  u32 ii;
+
+  itp->itp_n_sa_in = vec_len (sas_in);
+  for (ii = 0; ii < itp->itp_n_sa_in; ii++)
+    itp->itp_in_sas[ii] = sas_in[ii];
+  itp->itp_out_sa = sa_out;
+
+  ipsec_sa_lock (itp->itp_out_sa);
+
+  /* *INDENT-OFF* */
+  FOR_EACH_IPSEC_PROTECT_INPUT_SAI(itp, sai,
+  ({
+    ipsec_sa_lock(sai);
+  }));
+  ipsec_tun_protect_set_crypto_addr(itp);
+  /* *INDENT-ON* */
 
   /*
    * add to the DB against each SA
    */
-  ipsec_tun_protect_db_add (im, itp);
+  ipsec_tun_protect_rx_db_add (im, itp);
+  ipsec_tun_protect_tx_db_add (itp);
 
-  /*
-   * enable the encrypt feature for egress.
-   */
-  ipsec_tun_protect_feature_set (itp, 1);
+  ITP_DBG (itp, "configured");
 }
 
 static void
@@ -224,15 +437,14 @@ ipsec_tun_protect_unconfig (ipsec_main_t * im, ipsec_tun_protect_t * itp)
   ipsec_sa_t *sa;
   index_t sai;
 
-  ipsec_tun_protect_feature_set (itp, 0);
-
   /* *INDENT-OFF* */
   FOR_EACH_IPSEC_PROTECT_INPUT_SA(itp, sa,
   ({
     ipsec_sa_unset_IS_PROTECT (sa);
   }));
 
-  ipsec_tun_protect_db_remove (im, itp);
+  ipsec_tun_protect_rx_db_remove (im, itp);
+  ipsec_tun_protect_tx_db_remove (itp);
 
   ipsec_sa_unlock(itp->itp_out_sa);
 
@@ -241,31 +453,25 @@ ipsec_tun_protect_unconfig (ipsec_main_t * im, ipsec_tun_protect_t * itp)
     ipsec_sa_unlock(sai);
   }));
   /* *INDENT-ON* */
-}
-
-index_t
-ipsec_tun_protect_find (u32 sw_if_index)
-{
-  if (vec_len (ipsec_protect_db.tunnels) < sw_if_index)
-    return (INDEX_INVALID);
-
-  return (ipsec_protect_db.tunnels[sw_if_index]);
+  ITP_DBG (itp, "unconfigured");
 }
 
 int
-ipsec_tun_protect_update_one (u32 sw_if_index, u32 sa_out, u32 sa_in)
+ipsec_tun_protect_update_one (u32 sw_if_index,
+			      const ip_address_t * nh, u32 sa_out, u32 sa_in)
 {
   u32 *sas_in = NULL;
   int rv;
 
   vec_add1 (sas_in, sa_in);
-  rv = ipsec_tun_protect_update (sw_if_index, sa_out, sas_in);
+  rv = ipsec_tun_protect_update (sw_if_index, nh, sa_out, sas_in);
 
   return (rv);
 }
 
 int
-ipsec_tun_protect_update_out (u32 sw_if_index, u32 sa_out)
+ipsec_tun_protect_update_out (u32 sw_if_index,
+			      const ip_address_t * nh, u32 sa_out)
 {
   u32 itpi, *sas_in, sai, *saip;
   ipsec_tun_protect_t *itp;
@@ -275,24 +481,22 @@ ipsec_tun_protect_update_out (u32 sw_if_index, u32 sa_out)
   sas_in = NULL;
   rv = 0;
   im = &ipsec_main;
-  vec_validate_init_empty (ipsec_protect_db.tunnels, sw_if_index,
-			   INDEX_INVALID);
-  itpi = ipsec_protect_db.tunnels[sw_if_index];
+
+  itpi = ipsec_tun_protect_find (sw_if_index, nh);
 
   if (INDEX_INVALID == itpi)
     {
       return (VNET_API_ERROR_INVALID_INTERFACE);
     }
 
-  itp = pool_elt_at_index (ipsec_protect_pool, itpi);
+  itp = pool_elt_at_index (ipsec_tun_protect_pool, itpi);
 
-  /* *INDENT-0FF* */
-  FOR_EACH_IPSEC_PROTECT_INPUT_SAI (itp, sai, (
-						{
-						ipsec_sa_lock (sai);
-						vec_add1 (sas_in, sai);
-						}
-				    ));
+  /* *INDENT-OFF* */
+  FOR_EACH_IPSEC_PROTECT_INPUT_SAI (itp, sai,
+  ({
+    ipsec_sa_lock (sai);
+    vec_add1 (sas_in, sai);
+  }));
   /* *INDENT-ON* */
 
   sa_out = ipsec_sa_find_and_lock (sa_out);
@@ -315,7 +519,8 @@ out:
 }
 
 int
-ipsec_tun_protect_update_in (u32 sw_if_index, u32 sa_in)
+ipsec_tun_protect_update_in (u32 sw_if_index,
+			     const ip_address_t * nh, u32 sa_in)
 {
   u32 itpi, *sas_in, sa_out;
   ipsec_tun_protect_t *itp;
@@ -325,9 +530,7 @@ ipsec_tun_protect_update_in (u32 sw_if_index, u32 sa_in)
   sas_in = NULL;
   rv = 0;
   im = &ipsec_main;
-  vec_validate_init_empty (ipsec_protect_db.tunnels, sw_if_index,
-			   INDEX_INVALID);
-  itpi = ipsec_protect_db.tunnels[sw_if_index];
+  itpi = ipsec_tun_protect_find (sw_if_index, nh);
 
   if (INDEX_INVALID == itpi)
     {
@@ -343,7 +546,7 @@ ipsec_tun_protect_update_in (u32 sw_if_index, u32 sa_in)
     }
   vec_add1 (sas_in, sa_in);
 
-  itp = pool_elt_at_index (ipsec_protect_pool, itpi);
+  itp = pool_elt_at_index (ipsec_tun_protect_pool, itpi);
   sa_out = itp->itp_out_sa;
 
   ipsec_sa_lock (sa_out);
@@ -358,19 +561,40 @@ out:
   return (rv);
 }
 
+static void
+ipsec_tun_protect_update_from_teib (ipsec_tun_protect_t * itp,
+				    const teib_entry_t * ne)
+{
+  if (NULL != ne)
+    {
+      const fib_prefix_t *pfx;
+
+      pfx = teib_entry_get_nh (ne);
+
+      ip46_address_copy (&itp->itp_tun.dst, &pfx->fp_addr);
+    }
+  else
+    ip46_address_reset (&itp->itp_tun.dst);
+}
+
 int
-ipsec_tun_protect_update (u32 sw_if_index, u32 sa_out, u32 * sas_in)
+ipsec_tun_protect_update (u32 sw_if_index,
+			  const ip_address_t * nh, u32 sa_out, u32 * sas_in)
 {
   ipsec_tun_protect_t *itp;
   u32 itpi, ii, *saip;
   ipsec_main_t *im;
   int rv;
 
+  ITP_DBG2 ("update: %U/%U",
+	    format_vnet_sw_if_index_name, vnet_get_main (), sw_if_index,
+	    format_ip_address, nh);
+
   rv = 0;
   im = &ipsec_main;
-  vec_validate_init_empty (ipsec_protect_db.tunnels, sw_if_index,
-			   INDEX_INVALID);
-  itpi = ipsec_protect_db.tunnels[sw_if_index];
+  if (NULL == nh)
+    nh = &IP_ADDR_ALL_0;
+  itpi = ipsec_tun_protect_find (sw_if_index, nh);
 
   vec_foreach_index (ii, sas_in)
   {
@@ -407,17 +631,18 @@ ipsec_tun_protect_update (u32 sw_if_index, u32 sa_out, u32 * sas_in)
 	  goto out;
 	}
 
-      pool_get_zero (ipsec_protect_pool, itp);
+      pool_get_zero (ipsec_tun_protect_pool, itp);
 
       itp->itp_sw_if_index = sw_if_index;
-      ipsec_protect_db.tunnels[sw_if_index] = itp - ipsec_protect_pool;
-      ipsec_protect_db.count++;
 
       itp->itp_n_sa_in = vec_len (sas_in);
       for (ii = 0; ii < itp->itp_n_sa_in; ii++)
 	itp->itp_in_sas[ii] = sas_in[ii];
       itp->itp_out_sa = sa_out;
 
+      itp->itp_key = clib_mem_alloc (sizeof (*itp->itp_key));
+      ip_address_copy (itp->itp_key, nh);
+
       rv = dev_class->ip_tun_desc (sw_if_index,
 				   &itp->itp_tun.src,
 				   &itp->itp_tun.dst, &is_l2);
@@ -425,6 +650,18 @@ ipsec_tun_protect_update (u32 sw_if_index, u32 sa_out, u32 * sas_in)
       if (rv)
 	goto out;
 
+      if (ip46_address_is_zero (&itp->itp_tun.dst))
+	{
+	  /* tunnel has no destination address, presumably because it's p2mp
+	     in which case we use the nh that this is protection for */
+	  ip46_address_t peer;
+
+	  ip_address_to_46 (nh, &peer);
+
+	  ipsec_tun_protect_update_from_teib
+	    (itp, teib_entry_find (sw_if_index, &peer));
+	}
+
       if (is_l2)
 	itp->itp_flags |= IPSEC_PROTECT_L2;
 
@@ -451,18 +688,11 @@ ipsec_tun_protect_update (u32 sw_if_index, u32 sa_out, u32 * sas_in)
        *    of the tunnel we are protecting, else it's dropped.
        */
       ipsec_tun_protect_config (im, itp, sa_out, sas_in);
-
-      if (1 == hash_elts (im->tun4_protect_by_key))
-	ip4_register_protocol (IP_PROTOCOL_IPSEC_ESP,
-			       ipsec4_tun_input_node.index);
-      if (1 == hash_elts (im->tun6_protect_by_key))
-	ip6_register_protocol (IP_PROTOCOL_IPSEC_ESP,
-			       ipsec6_tun_input_node.index);
     }
   else
     {
       /* updating SAs only */
-      itp = pool_elt_at_index (ipsec_protect_pool, itpi);
+      itp = pool_elt_at_index (ipsec_tun_protect_pool, itpi);
 
       ipsec_tun_protect_unconfig (im, itp);
       ipsec_tun_protect_config (im, itp, sa_out, sas_in);
@@ -477,17 +707,21 @@ out:
 }
 
 int
-ipsec_tun_protect_del (u32 sw_if_index)
+ipsec_tun_protect_del (u32 sw_if_index, const ip_address_t * nh)
 {
   ipsec_tun_protect_t *itp;
   ipsec_main_t *im;
   index_t itpi;
 
+  ITP_DBG2 ("delete: %U/%U",
+	    format_vnet_sw_if_index_name, vnet_get_main (), sw_if_index,
+	    format_ip_address, nh);
+
   im = &ipsec_main;
+  if (NULL == nh)
+    nh = &IP_ADDR_ALL_0;
 
-  vec_validate_init_empty (ipsec_protect_db.tunnels, sw_if_index,
-			   INDEX_INVALID);
-  itpi = ipsec_protect_db.tunnels[sw_if_index];
+  itpi = ipsec_tun_protect_find (sw_if_index, nh);
 
   if (INDEX_INVALID == itpi)
     return (VNET_API_ERROR_NO_SUCH_ENTRY);
@@ -495,9 +729,8 @@ ipsec_tun_protect_del (u32 sw_if_index)
   itp = ipsec_tun_protect_get (itpi);
   ipsec_tun_protect_unconfig (im, itp);
 
-  ipsec_protect_db.tunnels[itp->itp_sw_if_index] = INDEX_INVALID;
-
-  pool_put (ipsec_protect_pool, itp);
+  clib_mem_free (itp->itp_key);
+  pool_put (ipsec_tun_protect_pool, itp);
 
   if (0 == hash_elts (im->tun4_protect_by_key))
     ip4_unregister_protocol (IP_PROTOCOL_IPSEC_ESP);
@@ -513,13 +746,150 @@ ipsec_tun_protect_walk (ipsec_tun_protect_walk_cb_t fn, void *ctx)
   index_t itpi;
 
   /* *INDENT-OFF* */
-  pool_foreach_index(itpi, ipsec_protect_pool,
+  pool_foreach_index(itpi, ipsec_tun_protect_pool,
+  ({
+    fn (itpi, ctx);
+  }));
+  /* *INDENT-ON* */
+}
+
+void
+ipsec_tun_protect_walk_itf (u32 sw_if_index,
+			    ipsec_tun_protect_walk_cb_t fn, void *ctx)
+{
+  ipsec_tun_protect_itf_db_t *idi;
+  ip_address_t *key;
+  index_t itpi;
+
+  if (vec_len (itp_db.id_itf) <= sw_if_index)
+    return;
+
+  idi = &itp_db.id_itf[sw_if_index];
+
+  /* *INDENT-OFF* */
+  hash_foreach(key, itpi, idi->id_hash,
   ({
     fn (itpi, ctx);
   }));
   /* *INDENT-ON* */
+  if (INDEX_INVALID != idi->id_itp)
+    fn (idi->id_itp, ctx);
 }
 
+static void
+ipsec_tun_protect_adj_delegate_adj_deleted (adj_delegate_t * ad)
+{
+  /* remove our delegate */
+  adj_delegate_remove (ad->ad_adj_index, ipsec_tun_adj_delegate_type);
+  ipsec_tun_protect_add_adj (ad->ad_adj_index, INDEX_INVALID);
+}
+
+static void
+ipsec_tun_protect_adj_delegate_adj_created (adj_index_t ai)
+{
+  /* add our delegate if there is protection for this neighbour */
+  ip_address_t ip = IP_ADDRESS_V4_ALL_0S;
+  ip_adjacency_t *adj;
+  index_t itpi;
+
+  adj = adj_get (ai);
+
+  if (adj->lookup_next_index != IP_LOOKUP_NEXT_MIDCHAIN)
+    return;
+
+  ip_address_from_46 (&adj->sub_type.midchain.next_hop,
+		      adj->ia_nh_proto, &ip);
+
+  itpi = ipsec_tun_protect_find (adj->rewrite_header.sw_if_index, &ip);
+
+  if (INDEX_INVALID != itpi)
+    {
+      const ipsec_tun_protect_t *itp;
+
+      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);
+    }
+}
+
+static u8 *
+ipsec_tun_protect_adj_delegate_format (const adj_delegate_t * aed, u8 * s)
+{
+  const ipsec_tun_protect_t *itp;
+
+  itp = ipsec_tun_protect_from_const_base (aed);
+  s = format (s, "ipsec-tun-protect:\n%U", format_ipsec_tun_protect, itp);
+
+  return (s);
+}
+
+static void
+ipsec_tun_teib_entry_added (const teib_entry_t * ne)
+{
+  const ip46_address_t *peer46;
+  ipsec_tun_protect_t *itp;
+  ip_address_t peer;
+  index_t itpi;
+
+  peer46 = teib_entry_get_peer (ne);
+  ip_address_from_46 (peer46,
+		      (ip46_address_is_ip4 (peer46) ?
+		       FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6), &peer);
+
+  itpi = ipsec_tun_protect_find (teib_entry_get_sw_if_index (ne), &peer);
+
+  if (INDEX_INVALID == itpi)
+    return;
+
+  itp = ipsec_tun_protect_get (itpi);
+  ipsec_tun_protect_rx_db_remove (&ipsec_main, itp);
+  ipsec_tun_protect_update_from_teib (itp, ne);
+  ipsec_tun_protect_set_crypto_addr (itp);
+  ipsec_tun_protect_rx_db_add (&ipsec_main, itp);
+
+  ITP_DBG (itp, "teib-added");
+}
+
+static void
+ipsec_tun_teib_entry_deleted (const teib_entry_t * ne)
+{
+  const ip46_address_t *peer46;
+  ipsec_tun_protect_t *itp;
+  ip_address_t peer;
+  index_t itpi;
+
+  peer46 = teib_entry_get_peer (ne);
+  ip_address_from_46 (peer46,
+		      (ip46_address_is_ip4 (peer46) ?
+		       FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6), &peer);
+
+  itpi = ipsec_tun_protect_find (teib_entry_get_sw_if_index (ne), &peer);
+
+  if (INDEX_INVALID == itpi)
+    return;
+
+  itp = ipsec_tun_protect_get (itpi);
+  ipsec_tun_protect_rx_db_remove (&ipsec_main, itp);
+  ipsec_tun_protect_update_from_teib (itp, NULL);
+  ipsec_tun_protect_set_crypto_addr (itp);
+
+  ITP_DBG (itp, "teib-removed");
+}
+
+/**
+ * VFT registered with the adjacency delegate
+ */
+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_format = ipsec_tun_protect_adj_delegate_format,
+};
+
+const static teib_vft_t ipsec_tun_teib_vft = {
+  .nv_added = ipsec_tun_teib_entry_added,
+  .nv_deleted = ipsec_tun_teib_entry_deleted,
+};
+
 clib_error_t *
 ipsec_tunnel_protect_init (vlib_main_t * vm)
 {
@@ -537,6 +907,13 @@ ipsec_tunnel_protect_init (vlib_main_t * vm)
   ipsec_add_feature ("ip6-output", "esp6-no-crypto",
 		     &im->esp6_no_crypto_tun_feature_index);
 
+  ipsec_tun_adj_delegate_type =
+    adj_delegate_register_new_type (&ipsec_tun_adj_delegate_vft);
+
+  ipsec_tun_protect_logger = vlib_log_register_class ("ipsec", "tun");
+
+  teib_register (&ipsec_tun_teib_vft);
+
   return 0;
 }
 
diff --git a/src/vnet/ipsec/ipsec_tun.h b/src/vnet/ipsec/ipsec_tun.h
index 840840335a5..56d3de14704 100644
--- a/src/vnet/ipsec/ipsec_tun.h
+++ b/src/vnet/ipsec/ipsec_tun.h
@@ -77,6 +77,8 @@ typedef struct ipsec_tun_protect_t_
 
   ipsec_ep_t itp_tun;
 
+  ip_address_t *itp_key;
+
 } ipsec_tun_protect_t;
 
 #define FOR_EACH_IPSEC_PROTECT_INPUT_SAI(_itp, _sai, body) \
@@ -96,21 +98,28 @@ typedef struct ipsec_tun_protect_t_
   }                                                        \
 }
 
-extern int ipsec_tun_protect_update_one (u32 sw_if_index, u32 sa_out,
-					 u32 sa_in);
-extern int ipsec_tun_protect_update (u32 sw_if_index, u32 sa_out,
-				     u32 * sa_ins);
-extern int ipsec_tun_protect_update_in (u32 sw_if_index, u32 sa_in);
-extern int ipsec_tun_protect_update_out (u32 sw_if_index, u32 sa_out);
+extern int ipsec_tun_protect_update_one (u32 sw_if_index,
+					 const ip_address_t * nh,
+					 u32 sa_out, u32 sa_in);
+extern int ipsec_tun_protect_update (u32 sw_if_index,
+				     const ip_address_t * nh,
+				     u32 sa_out, u32 * sa_ins);
+extern int ipsec_tun_protect_update_in (u32 sw_if_index,
+					const ip_address_t * nh, u32 sa_in);
+extern int ipsec_tun_protect_update_out (u32 sw_if_index,
+					 const ip_address_t * nh, u32 sa_out);
 
-extern int ipsec_tun_protect_del (u32 sw_if_index);
+extern int ipsec_tun_protect_del (u32 sw_if_index, const ip_address_t * nh);
 
 typedef walk_rc_t (*ipsec_tun_protect_walk_cb_t) (index_t itpi, void *arg);
 extern void ipsec_tun_protect_walk (ipsec_tun_protect_walk_cb_t fn,
 				    void *cttx);
-extern index_t ipsec_tun_protect_find (u32 sw_if_index);
+extern void ipsec_tun_protect_walk_itf (u32 sw_if_index,
+					ipsec_tun_protect_walk_cb_t fn,
+					void *cttx);
 
 extern u8 *format_ipsec_tun_protect (u8 * s, va_list * args);
+extern u8 *format_ipsec_tun_protect_index (u8 * s, va_list * args);
 
 // FIXME
 extern vlib_node_registration_t ipsec4_tun_input_node;
@@ -119,7 +128,7 @@ extern vlib_node_registration_t ipsec6_tun_input_node;
 /*
  * DP API
  */
-extern ipsec_tun_protect_t *ipsec_protect_pool;
+extern ipsec_tun_protect_t *ipsec_tun_protect_pool;
 
 typedef struct ipsec_tun_lkup_result_t_
 {
@@ -137,7 +146,17 @@ typedef struct ipsec_tun_lkup_result_t_
 always_inline ipsec_tun_protect_t *
 ipsec_tun_protect_get (u32 index)
 {
-  return (pool_elt_at_index (ipsec_protect_pool, index));
+  return (pool_elt_at_index (ipsec_tun_protect_pool, index));
+}
+
+extern index_t *ipsec_tun_protect_sa_by_adj_index;
+always_inline index_t
+ipsec_tun_protect_get_sa_out (adj_index_t ai)
+{
+  ASSERT (vec_len (ipsec_tun_protect_sa_by_adj_index) > ai);
+  ASSERT (INDEX_INVALID != ipsec_tun_protect_sa_by_adj_index[ai]);
+
+  return (ipsec_tun_protect_sa_by_adj_index[ai]);
 }
 
 /*
diff --git a/src/vnet/ipsec/ipsec_tun_in.c b/src/vnet/ipsec/ipsec_tun_in.c
index 35d268f58bc..501ab027634 100644
--- a/src/vnet/ipsec/ipsec_tun_in.c
+++ b/src/vnet/ipsec/ipsec_tun_in.c
@@ -273,7 +273,7 @@ ipsec_tun_protect_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	    }
 	}
 
-      itp0 = pool_elt_at_index (ipsec_protect_pool, itr0.tun_index);
+      itp0 = pool_elt_at_index (ipsec_tun_protect_pool, itr0.tun_index);
       vnet_buffer (b[0])->ipsec.sad_index = itr0.sa_index;
       vnet_buffer (b[0])->ipsec.protect_index = itr0.tun_index;