gtpu: support separate rx-decap and encap-tx teid values

Support separate local and remote TEIDs, with local (or RX) one used
for GTPU tunnel RX/decap and remote (or TX) one used encap/TX.
Updated current gtpu API to support seperate RX/TX TEIDs and added new
gtpu_tunnel_update_tteid API to allow changing TX-TEID of an existing
GTPU tunnel.  The current tunnel field "teid" is used for RX-TEID and
a new field "tteid" is used for TX-TEID.

Type: improvement

Signed-off-by: John Lo <loj@cisco.com>
Change-Id: I549d79750a34bb965036da298c0ca894d15c2c20

6 files changed, 232 insertions, 76 deletions

diff --git a/src/plugins/gtpu/gtpu.api b/src/plugins/gtpu/gtpu.api
index f084cc84e19..ec4933af197 100644
--- a/src/plugins/gtpu/gtpu.api
+++ b/src/plugins/gtpu/gtpu.api
@@ -13,11 +13,11 @@
  * limitations under the License.
  */
 
-option version = "2.0.0";
+option version = "2.0.1";
 import "vnet/interface_types.api";
 import "vnet/ip/ip_types.api";
 
-/** \brief Set or delete an GTPU tunnel
+/** \brief Create or delete a GTPU tunnel
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
     @param is_add - add address if non-zero, else delete
@@ -26,7 +26,8 @@ import "vnet/ip/ip_types.api";
     @param mcast_sw_if_index - version, O-bit and C-bit (see nsh_packet.h)
     @param encap_vrf_id - fib identifier used for outgoing encapsulated packets
     @param decap_next_index - the index of the next node if success
-    @param teid - Local Tunnel Endpoint Identifier
+    @param teid - Local (rx) Tunnel Endpoint Identifier
+    @param tteid - Remote (tx) Tunnel Endpoint Identifier
 */
 define gtpu_add_del_tunnel
 {
@@ -39,7 +40,8 @@ define gtpu_add_del_tunnel
   u32 encap_vrf_id;
   u32 decap_next_index;
   u32 teid;
-  option vat_help = "src <ip-addr> { dst <ip-addr> | group <mcast-ip-addr> { <intfc> | mcast_sw_if_index <nn> } } teid <teid> [encap-vrf-id <nn>] [decap-next <l2|nn>] [del]";
+  u32 tteid;
+  option vat_help = "src <ip-addr> {dst <ip-addr> | group <mcast-ip-addr> {<intfc> | mcast_sw_if_index <nn>}} teid <nn> [tteid <nn>] [encap-vrf-id <nn>] [decap-next <l2|nn>] [del]";
 };
 
 /** \brief reply for set or delete an GTPU tunnel
@@ -54,6 +56,25 @@ define gtpu_add_del_tunnel_reply
   vl_api_interface_index_t sw_if_index;
 };
 
+/** \brief Update GTPU tunnel TX TEID
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param dst_address - GTPU tunnel's destination address.
+    @param encap_vrf_id - fib identifier used for outgoing encapsulated packets
+    @param teid - Local (rx) Tunnel Endpoint Identifier
+    @param tteid - remote (tx) Tunnel Endpoint Identifier
+*/
+autoreply define gtpu_tunnel_update_tteid
+{
+  u32 client_index;
+  u32 context;
+  vl_api_address_t dst_address;
+  u32 encap_vrf_id;
+  u32 teid;
+  u32 tteid;
+  option vat_help = "dst <ip-addr> teid <nn> tteid <nn> [encap-vrf-id <nn>]";
+};
+
 /** \brief Dump GTPU tunnel
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
@@ -75,7 +96,8 @@ define gtpu_tunnel_dump
     @param mcast_sw_if_index - version, O-bit and C-bit (see nsh_packet.h)
     @param encap_vrf_id - fib identifier used for outgoing encapsulated packets
     @param decap_next_index - the index of the next node if success
-    @param teid - Local Tunnel Endpoint Identifier
+    @param teid - Local (rx) Tunnel Endpoint Identifier
+    @param tteid - Remote (tx) Tunnel Endpoint Identifier
 */
 define gtpu_tunnel_details
 {
@@ -87,6 +109,7 @@ define gtpu_tunnel_details
   u32 encap_vrf_id;
   u32 decap_next_index;
   u32 teid;
+  u32 tteid;
 };
 
 /** \brief Interface set gtpu-bypass request
diff --git a/src/plugins/gtpu/gtpu.c b/src/plugins/gtpu/gtpu.c
index 386721b6b39..ab221f1f562 100644
--- a/src/plugins/gtpu/gtpu.c
+++ b/src/plugins/gtpu/gtpu.c
@@ -56,8 +56,8 @@ u8 * format_gtpu_encap_trace (u8 * s, va_list * args)
   gtpu_encap_trace_t * t
       = va_arg (*args, gtpu_encap_trace_t *);
 
-  s = format (s, "GTPU encap to gtpu_tunnel%d teid %d",
-	      t->tunnel_index, t->teid);
+  s = format (s, "GTPU encap to gtpu_tunnel%d tteid %d",
+	      t->tunnel_index, t->tteid);
   return s;
 }
 
@@ -95,11 +95,12 @@ format_gtpu_tunnel (u8 * s, va_list * args)
     is_ipv6 ? im6->fibs[t->encap_fib_index].ft_table_id :
     im4->fibs[t->encap_fib_index].ft_table_id;
 
-  s = format (s, "[%d] src %U dst %U teid %d encap-vrf-id %d sw-if-idx %d ",
+  s = format (s, "[%d] src %U dst %U teid %d tteid %d "
+	      "encap-vrf-id %d sw-if-idx %d ",
 	      t - ngm->tunnels,
 	      format_ip46_address, &t->src, IP46_TYPE_ANY,
 	      format_ip46_address, &t->dst, IP46_TYPE_ANY,
-	      t->teid,  encap_vrf_id, t->sw_if_index);
+	      t->teid, t->tteid, encap_vrf_id, t->sw_if_index);
 
   s = format (s, "encap-dpo-idx %d ", t->next_dpo.dpoi_index);
   s = format (s, "decap-next-%U ", format_decap_next, t->decap_next_index);
@@ -225,7 +226,8 @@ const static fib_node_vft_t gtpu_vft = {
 
 
 #define foreach_copy_field                      \
-_(teid)                                          \
+_(teid)                                         \
+_(tteid)                                        \
 _(mcast_sw_if_index)                            \
 _(encap_fib_index)                              \
 _(decap_next_index)                             \
@@ -286,7 +288,7 @@ ip_udp_gtpu_rewrite (gtpu_tunnel_t * t, bool is_ip6)
   /* GTPU header */
   gtpu->ver_flags = GTPU_V1_VER | GTPU_PT_GTP;
   gtpu->type = GTPU_TYPE_GTPU;
-  gtpu->teid = clib_host_to_net_u32 (t->teid);
+  gtpu->teid = clib_host_to_net_u32 (t->tteid);
 
   t->rewrite = r.rw;
   /* Now only support 8-byte gtpu header. TBD */
@@ -347,8 +349,8 @@ mcast_shared_remove (ip46_address_t * dst)
   hash_unset_mem_free (&gtpu_main.mcast_shared, dst);
 }
 
-int vnet_gtpu_add_del_tunnel
-  (vnet_gtpu_add_del_tunnel_args_t * a, u32 * sw_if_indexp)
+int vnet_gtpu_add_mod_del_tunnel
+  (vnet_gtpu_add_mod_del_tunnel_args_t * a, u32 * sw_if_indexp)
 {
   gtpu_main_t *gtm = &gtpu_main;
   gtpu_tunnel_t *t = 0;
@@ -373,7 +375,7 @@ int vnet_gtpu_add_del_tunnel
       p = hash_get_mem (gtm->gtpu6_tunnel_by_key, &key6);
     }
 
-  if (a->is_add)
+  if (a->opn == GTPU_ADD_TUNNEL)
     {
       l2input_main_t *l2im = &l2input_main;
 
@@ -395,6 +397,10 @@ int vnet_gtpu_add_del_tunnel
       foreach_copy_field;
 #undef _
 
+      /* default to same as local rx teid */
+      if (t->tteid == 0)
+	t->tteid = t->teid;
+
       ip_udp_gtpu_rewrite (t, is_ip6);
 
       /* clear the flow index */
@@ -559,13 +565,23 @@ int vnet_gtpu_add_del_tunnel
     }
   else
     {
-      /* deleting a tunnel: tunnel must exist */
+      /* mod-tteid or deleting a tunnel: tunnel must exist */
       if (!p)
 	return VNET_API_ERROR_NO_SUCH_ENTRY;
 
       t = pool_elt_at_index (gtm->tunnels, p[0]);
       sw_if_index = t->sw_if_index;
 
+      if (a->opn == GTPU_UPD_TTEID)
+	{
+	  if (a->tteid == 0)
+	    return VNET_API_ERROR_INVALID_VALUE;
+	  t->tteid = a->tteid;
+	  ip_udp_gtpu_rewrite (t, is_ip6);
+	  return 0;
+	}
+
+      /* delete tunnel */
       vnet_sw_interface_set_flags (vnm, t->sw_if_index, 0 /* down */ );
       vnet_sw_interface_t *si = vnet_get_sw_interface (vnm, t->sw_if_index);
       si->flags |= VNET_SW_INTERFACE_FLAG_HIDDEN;
@@ -604,7 +620,7 @@ int vnet_gtpu_add_del_tunnel
   if (sw_if_indexp)
     *sw_if_indexp = sw_if_index;
 
-  if (a->is_add)
+  if (a->opn == GTPU_ADD_TUNNEL)
     {
       /* register udp ports */
       if (!is_ip6 && !udp_is_valid_dst_port (UDP_DST_PORT_GTPU, 1))
@@ -662,7 +678,7 @@ gtpu_add_del_tunnel_command_fn (vlib_main_t * vm,
 {
   unformat_input_t _line_input, *line_input = &_line_input;
   ip46_address_t src, dst;
-  u8 is_add = 1;
+  u8 opn = GTPU_ADD_TUNNEL;
   u8 src_set = 0;
   u8 dst_set = 0;
   u8 grp_set = 0;
@@ -671,10 +687,10 @@ gtpu_add_del_tunnel_command_fn (vlib_main_t * vm,
   u32 encap_fib_index = 0;
   u32 mcast_sw_if_index = ~0;
   u32 decap_next_index = GTPU_INPUT_NEXT_L2_INPUT;
-  u32 teid = 0;
+  u32 teid = 0, tteid = 0;
   u32 tmp;
   int rv;
-  vnet_gtpu_add_del_tunnel_args_t _a, *a = &_a;
+  vnet_gtpu_add_mod_del_tunnel_args_t _a, *a = &_a;
   u32 tunnel_sw_if_index;
   clib_error_t *error = NULL;
 
@@ -690,7 +706,7 @@ gtpu_add_del_tunnel_command_fn (vlib_main_t * vm,
     {
       if (unformat (line_input, "del"))
 	{
-	  is_add = 0;
+	  opn = GTPU_DEL_TUNNEL;
 	}
       else if (unformat (line_input, "src %U",
 			 unformat_ip4_address, &src.ip4))
@@ -747,6 +763,10 @@ gtpu_add_del_tunnel_command_fn (vlib_main_t * vm,
 	;
       else if (unformat (line_input, "teid %d", &teid))
 	;
+      else if (unformat (line_input, "tteid %d", &tteid))
+	;
+      else if (unformat (line_input, "upd-tteid %d", &tteid))
+	opn = GTPU_UPD_TTEID;
       else
 	{
 	  error = clib_error_return (0, "parse error: '%U'",
@@ -755,7 +775,13 @@ gtpu_add_del_tunnel_command_fn (vlib_main_t * vm,
 	}
     }
 
-  if (src_set == 0)
+  if (teid == 0)
+    {
+      error = clib_error_return (0, "tunnel teid specified");
+      goto done;
+    }
+
+  if (src_set == 0 && opn == GTPU_ADD_TUNNEL)
     {
       error = clib_error_return (0, "tunnel src address not specified");
       goto done;
@@ -805,18 +831,18 @@ gtpu_add_del_tunnel_command_fn (vlib_main_t * vm,
 
   clib_memset (a, 0, sizeof (*a));
 
-  a->is_add = is_add;
+  a->opn = opn;
 
 #define _(x) a->x = x;
   foreach_copy_field;
 #undef _
 
-  rv = vnet_gtpu_add_del_tunnel (a, &tunnel_sw_if_index);
+  rv = vnet_gtpu_add_mod_del_tunnel (a, &tunnel_sw_if_index);
 
   switch (rv)
     {
     case 0:
-      if (is_add)
+      if (opn == GTPU_ADD_TUNNEL)
 	vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name,
 			 vnet_get_main (), tunnel_sw_if_index);
       break;
@@ -829,6 +855,10 @@ gtpu_add_del_tunnel_command_fn (vlib_main_t * vm,
       error = clib_error_return (0, "tunnel does not exist...");
       goto done;
 
+    case VNET_API_ERROR_INVALID_VALUE:
+      error = clib_error_return (0, "tx teid not specified...");
+      goto done;
+
     default:
       error = clib_error_return
 	(0, "vnet_gtpu_add_del_tunnel returned %d", rv);
@@ -844,30 +874,31 @@ done:
 /*?
  * Add or delete a GTPU Tunnel.
  *
- * GTPU provides the features needed to allow L2 bridge domains (BDs)
+ * GTPU can be used to transport Ethernet packets as its PDU type to
+ * provides allow L2 network or bridge domains (BDs)
  * to span multiple servers. This is done by building an L2 overlay on
  * top of an L3 network underlay using GTPU tunnels.
  *
- * This makes it possible for servers to be co-located in the same data
- * center or be separated geographically as long as they are reachable
- * through the underlay L3 network.
- *
- * You can refer to this kind of L2 overlay bridge domain as a GTPU
- * (Virtual eXtensible VLAN) segment.
+ * GTPU can also be used to transport IP packetes as its PDU type to
+ * allow IP forwarding over underlay network, e.g. between RAN and UPF
+ * for mobility deplyments.
  *
  * @cliexpar
  * Example of how to create a GTPU Tunnel:
- * @cliexcmd{create gtpu tunnel src 10.0.3.1 dst 10.0.3.3 teid 13 encap-vrf-id 7}
+ * @cliexcmd{create gtpu tunnel src 10.0.3.1 dst 10.0.3.3 teid 13 tteid 55 encap-vrf-id 7}
  * Example of how to delete a GTPU Tunnel:
- * @cliexcmd{create gtpu tunnel src 10.0.3.1 dst 10.0.3.3 teid 13 del}
+ * @cliexcmd{create gtpu tunnel src 10.0.3.1 dst 10.0.3.3 teid 13 encap-vrf-id 7 del}
+ * Example of how to update tx TEID of a GTPU Tunnel:
+ * @cliexcmd{create gtpu tunnel src 10.0.3.1 dst 10.0.3.3 encap-vrf-id 7 upd-tteid 55}
  ?*/
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (create_gtpu_tunnel_command, static) = {
   .path = "create gtpu tunnel",
   .short_help =
-  "create gtpu tunnel src <local-vtep-addr>"
-  " {dst <remote-vtep-addr>|group <mcast-vtep-addr> <intf-name>} teid <nn>"
-  " [encap-vrf-id <nn>] [decap-next [l2|ip4|ip6|node <name>]] [del]",
+  "create gtpu tunnel src <local-tep-addr>"
+  " {dst <remote-tep-addr>|group <mcast-addr> <intf-name>}"
+  " teid <nn> [tteid <nn>] [encap-vrf-id <nn>]"
+  " [decap-next [l2|ip4|ip6|node <name>]] [del | upd-tteid <nn>]",
   .function = gtpu_add_del_tunnel_command_fn,
 };
 /* *INDENT-ON* */
@@ -899,7 +930,7 @@ show_gtpu_tunnel_command_fn (vlib_main_t * vm,
  * @cliexpar
  * Example of how to display the GTPU Tunnel entries:
  * @cliexstart{show gtpu tunnel}
- * [0] src 10.0.3.1 dst 10.0.3.3 teid 13 encap_fib_index 0 sw_if_index 5 decap_next l2
+ * [0] src 10.0.3.1 dst 10.0.3.3 teid 13 tx-teid 55 encap_fib_index 0 sw_if_index 5 decap_next l2
  * @cliexend
  ?*/
 /* *INDENT-OFF* */
diff --git a/src/plugins/gtpu/gtpu.h b/src/plugins/gtpu/gtpu.h
index 6a758ee6847..07616419070 100644
--- a/src/plugins/gtpu/gtpu.h
+++ b/src/plugins/gtpu/gtpu.h
@@ -135,8 +135,9 @@ typedef struct
   /* FIB DPO for IP forwarding of gtpu encap packet */
   dpo_id_t next_dpo;
 
-  /* gtpu teid in HOST byte order */
+  /* gtpu local(rx) and remote(tx) TEIDs in HOST byte order */
   u32 teid;
+  u32 tteid;
 
   /* tunnel src and dst addresses */
   ip46_address_t src;
@@ -248,21 +249,25 @@ u8 *format_gtpu_encap_trace (u8 * s, va_list * args);
 
 typedef struct
 {
-  u8 is_add;
+  u8 opn;
+#define GTPU_DEL_TUNNEL 0
+#define GTPU_ADD_TUNNEL 1
+#define GTPU_UPD_TTEID  2
   ip46_address_t src, dst;
   u32 mcast_sw_if_index;
   u32 encap_fib_index;
   u32 decap_next_index;
-  u32 teid;
-} vnet_gtpu_add_del_tunnel_args_t;
+  u32 teid;			/* local  or rx teid */
+  u32 tteid;			/* remote or tx teid */
+} vnet_gtpu_add_mod_del_tunnel_args_t;
 
-int vnet_gtpu_add_del_tunnel
-  (vnet_gtpu_add_del_tunnel_args_t * a, u32 * sw_if_indexp);
+int vnet_gtpu_add_mod_del_tunnel
+  (vnet_gtpu_add_mod_del_tunnel_args_t * a, u32 * sw_if_indexp);
 
 typedef struct
 {
   u32 tunnel_index;
-  u32 teid;
+  u32 tteid;
 } gtpu_encap_trace_t;
 
 void vnet_int_gtpu_bypass_mode (u32 sw_if_index, u8 is_ip6, u8 is_enable);
diff --git a/src/plugins/gtpu/gtpu_api.c b/src/plugins/gtpu/gtpu_api.c
index 24fb8e2eae2..1100a7f90c1 100644
--- a/src/plugins/gtpu/gtpu_api.c
+++ b/src/plugins/gtpu/gtpu_api.c
@@ -116,26 +116,27 @@ static void vl_api_gtpu_add_del_tunnel_t_handler
 {
   vl_api_gtpu_add_del_tunnel_reply_t *rmp;
   int rv = 0;
-  ip4_main_t *im = &ip4_main;
   gtpu_main_t *gtm = &gtpu_main;
 
-  uword *p = hash_get (im->fib_index_by_table_id, ntohl (mp->encap_vrf_id));
-  if (!p)
-    {
-      rv = VNET_API_ERROR_NO_SUCH_FIB;
-      goto out;
-    }
-
-  vnet_gtpu_add_del_tunnel_args_t a = {
-    .is_add = mp->is_add,
+  vnet_gtpu_add_mod_del_tunnel_args_t a = {
+    .opn = mp->is_add ? GTPU_ADD_TUNNEL : GTPU_DEL_TUNNEL,
     .mcast_sw_if_index = ntohl (mp->mcast_sw_if_index),
-    .encap_fib_index = p[0],
     .decap_next_index = ntohl (mp->decap_next_index),
     .teid = ntohl (mp->teid),
+    .tteid = ntohl (mp->tteid),
   };
   ip_address_decode (&mp->dst_address, &a.dst);
   ip_address_decode (&mp->src_address, &a.src);
 
+  u8 is_ipv6 = !ip46_address_is_ip4 (&a.dst);
+  a.encap_fib_index = fib_table_find (fib_ip_proto (is_ipv6),
+				      ntohl (mp->encap_vrf_id));
+  if (a.encap_fib_index == ~0)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_FIB;
+      goto out;
+    }
+
   /* Check src & dst are different */
   if (ip46_address_cmp (&a.dst, &a.src) == 0)
     {
@@ -150,7 +151,7 @@ static void vl_api_gtpu_add_del_tunnel_t_handler
     }
 
   u32 sw_if_index = ~0;
-  rv = vnet_gtpu_add_del_tunnel (&a, &sw_if_index);
+  rv = vnet_gtpu_add_mod_del_tunnel (&a, &sw_if_index);
 
 out:
   /* *INDENT-OFF* */
@@ -161,6 +162,35 @@ out:
   /* *INDENT-ON* */
 }
 
+static void vl_api_gtpu_tunnel_update_tteid_t_handler
+  (vl_api_gtpu_tunnel_update_tteid_t * mp)
+{
+  vl_api_gtpu_tunnel_update_tteid_reply_t *rmp;
+  int rv = 0;
+  gtpu_main_t *gtm = &gtpu_main;
+
+  vnet_gtpu_add_mod_del_tunnel_args_t a = {
+    .opn = GTPU_UPD_TTEID,
+    .teid = ntohl (mp->teid),
+    .tteid = ntohl (mp->tteid),
+  };
+  ip_address_decode (&mp->dst_address, &a.dst);
+
+  u8 is_ipv6 = !ip46_address_is_ip4 (&a.dst);
+  a.encap_fib_index = fib_table_find (fib_ip_proto (is_ipv6),
+				      ntohl (mp->encap_vrf_id));
+  if (a.encap_fib_index == ~0)
+    {
+      rv = VNET_API_ERROR_NO_SUCH_FIB;
+      goto out;
+    }
+
+  rv = vnet_gtpu_add_mod_del_tunnel (&a, 0);
+
+out:
+  REPLY_MACRO (VL_API_GTPU_TUNNEL_UPDATE_TTEID_REPLY);
+}
+
 static void send_gtpu_tunnel_details
   (gtpu_tunnel_t * t, vl_api_registration_t * reg, u32 context)
 {
@@ -184,6 +214,7 @@ static void send_gtpu_tunnel_details
     htonl (im4->fibs[t->encap_fib_index].ft_table_id);
   rmp->mcast_sw_if_index = htonl (t->mcast_sw_if_index);
   rmp->teid = htonl (t->teid);
+  rmp->tteid = htonl (t->tteid);
   rmp->decap_next_index = htonl (t->decap_next_index);
   rmp->sw_if_index = htonl (t->sw_if_index);
   rmp->context = context;
diff --git a/src/plugins/gtpu/gtpu_encap.c b/src/plugins/gtpu/gtpu_encap.c
index e6b2ce589d0..4b7d98786f4 100644
--- a/src/plugins/gtpu/gtpu_encap.c
+++ b/src/plugins/gtpu/gtpu_encap.c
@@ -465,7 +465,7 @@ gtpu_encap_inline (vlib_main_t * vm,
               gtpu_encap_trace_t *tr =
                 vlib_add_trace (vm, node, b0, sizeof (*tr));
               tr->tunnel_index = t0 - gtm->tunnels;
-              tr->teid = t0->teid;
+              tr->tteid = t0->tteid;
            }
 
           if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED))
@@ -473,7 +473,7 @@ gtpu_encap_inline (vlib_main_t * vm,
               gtpu_encap_trace_t *tr =
                 vlib_add_trace (vm, node, b1, sizeof (*tr));
               tr->tunnel_index = t1 - gtm->tunnels;
-              tr->teid = t1->teid;
+              tr->tteid = t1->tteid;
             }
 
 	  if (PREDICT_FALSE(b2->flags & VLIB_BUFFER_IS_TRACED))
@@ -481,7 +481,7 @@ gtpu_encap_inline (vlib_main_t * vm,
               gtpu_encap_trace_t *tr =
                 vlib_add_trace (vm, node, b2, sizeof (*tr));
               tr->tunnel_index = t2 - gtm->tunnels;
-              tr->teid = t2->teid;
+              tr->tteid = t2->tteid;
            }
 
           if (PREDICT_FALSE(b3->flags & VLIB_BUFFER_IS_TRACED))
@@ -489,7 +489,7 @@ gtpu_encap_inline (vlib_main_t * vm,
               gtpu_encap_trace_t *tr =
                 vlib_add_trace (vm, node, b3, sizeof (*tr));
               tr->tunnel_index = t3 - gtm->tunnels;
-              tr->teid = t3->teid;
+              tr->tteid = t3->tteid;
             }
 
 	  vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
@@ -643,7 +643,7 @@ gtpu_encap_inline (vlib_main_t * vm,
               gtpu_encap_trace_t *tr =
                 vlib_add_trace (vm, node, b0, sizeof (*tr));
               tr->tunnel_index = t0 - gtm->tunnels;
-              tr->teid = t0->teid;
+              tr->tteid = t0->tteid;
             }
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next,
diff --git a/src/plugins/gtpu/gtpu_test.c b/src/plugins/gtpu/gtpu_test.c
index c780bd77d85..373e7888341 100644
--- a/src/plugins/gtpu/gtpu_test.c
+++ b/src/plugins/gtpu/gtpu_test.c
@@ -13,6 +13,7 @@
  * limitations under the License.
  */
 
+#include <unistd.h>
 #include <vat/vat.h>
 #include <vlibapi/api.h>
 #include <vlibmemory/api.h>
@@ -245,7 +246,7 @@ api_gtpu_add_del_tunnel (vat_main_t * vam)
   u32 mcast_sw_if_index = ~0;
   u32 encap_vrf_id = 0;
   u32 decap_next_index = ~0;
-  u32 teid = 0;
+  u32 teid = 0, tteid = 0;
   int ret;
 
   /* Can't "universally zero init" (={0}) due to GCC bug 53119 */
@@ -316,6 +317,8 @@ api_gtpu_add_del_tunnel (vat_main_t * vam)
       ;
       else if (unformat (line_input, "teid %d", &teid))
       ;
+      else if (unformat (line_input, "tteid %d", &tteid))
+      ;
       else
       {
 	errmsg ("parse error '%U'", format_unformat_error, line_input);
@@ -323,7 +326,7 @@ api_gtpu_add_del_tunnel (vat_main_t * vam)
       }
     }
 
-  if (src_set == 0)
+  if (is_add && src_set == 0)
     {
       errmsg ("tunnel src address not specified");
       return -99;
@@ -367,6 +370,7 @@ api_gtpu_add_del_tunnel (vat_main_t * vam)
   mp->decap_next_index = ntohl (decap_next_index);
   mp->mcast_sw_if_index = ntohl (mcast_sw_if_index);
   mp->teid = ntohl (teid);
+  mp->tteid = ntohl (tteid);
   mp->is_add = is_add;
 
   S (mp);
@@ -374,6 +378,64 @@ api_gtpu_add_del_tunnel (vat_main_t * vam)
   return ret;
 }
 
+static int
+api_gtpu_tunnel_update_tteid (vat_main_t * vam)
+{
+  unformat_input_t *line_input = vam->input;
+  vl_api_gtpu_tunnel_update_tteid_t *mp;
+  ip46_address_t dst;
+  u8 ipv6_set = 0;
+  u8 dst_set = 0;
+  u32 encap_vrf_id = 0;
+  u32 teid = 0, tteid = 0;
+  int ret;
+
+  /* Can't "universally zero init" (={0}) due to GCC bug 53119 */
+  clib_memset (&dst, 0, sizeof dst);
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "dst %U", unformat_ip4_address, &dst.ip4))
+      {
+	dst_set = 1;
+      }
+      else if (unformat (line_input, "dst %U", unformat_ip6_address, &dst.ip6))
+      {
+	ipv6_set = 1;
+	dst_set = 1;
+      }
+      else if (unformat (line_input, "encap-vrf-id %d", &encap_vrf_id))
+      ;
+      else if (unformat (line_input, "teid %d", &teid))
+      ;
+      else if (unformat (line_input, "tteid %d", &tteid))
+      ;
+      else
+      {
+	errmsg ("parse error '%U'", format_unformat_error, line_input);
+	return -99;
+      }
+    }
+
+  if (dst_set == 0)
+    {
+      errmsg ("tunnel dst address not specified");
+      return -99;
+    }
+
+  M (GTPU_TUNNEL_UPDATE_TTEID, mp);
+
+  ip_address_encode(&dst, ipv6_set ? IP46_TYPE_IP6 : IP46_TYPE_IP4,
+		    &mp->dst_address);
+  mp->encap_vrf_id = ntohl (encap_vrf_id);
+  mp->teid = ntohl (teid);
+  mp->tteid = ntohl (tteid);
+
+  S (mp);
+  W (ret);
+  return ret;
+}
+
 static void vl_api_gtpu_tunnel_details_t_handler
   (vl_api_gtpu_tunnel_details_t * mp)
 {
@@ -382,13 +444,14 @@ static void vl_api_gtpu_tunnel_details_t_handler
   ip46_address_t dst;
   ip_address_decode(&mp->dst_address, &dst);
   ip_address_decode(&mp->src_address, &src);
-  print (vam->ofp, "%11d%24U%24U%14d%18d%13d%19d",
-       ntohl (mp->sw_if_index),
-       format_ip46_address, &src, IP46_TYPE_ANY,
-       format_ip46_address, &dst, IP46_TYPE_ANY,
-       ntohl (mp->encap_vrf_id),
-       ntohl (mp->decap_next_index), ntohl (mp->teid),
-       ntohl (mp->mcast_sw_if_index));
+  print (vam->ofp, "%11d%24U%24U%14d%18d%13d%13d%19d",
+	 ntohl (mp->sw_if_index),
+	 format_ip46_address, &src, IP46_TYPE_ANY,
+	 format_ip46_address, &dst, IP46_TYPE_ANY,
+	 ntohl (mp->encap_vrf_id),
+	 ntohl (mp->decap_next_index),
+	 ntohl (mp->teid), ntohl (mp->tteid),
+	 ntohl (mp->mcast_sw_if_index));
 }
 
 static int
@@ -398,7 +461,6 @@ api_gtpu_tunnel_dump (vat_main_t * vam)
   vl_api_gtpu_tunnel_dump_t *mp;
   u32 sw_if_index;
   u8 sw_if_index_set = 0;
-  int ret;
 
   /* Parse args required to build the message */
   while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
@@ -416,9 +478,10 @@ api_gtpu_tunnel_dump (vat_main_t * vam)
 
   if (!vam->json_output)
     {
-      print (vam->ofp, "%11s%24s%24s%14s%18s%13s%19s",
-	   "sw_if_index", "src_address", "dst_address",
-	   "encap_vrf_id", "decap_next_index", "teid", "mcast_sw_if_index");
+      print (vam->ofp, "%11s%24s%24s%14s%18s%13s%13s%19s",
+	     "sw_if_index", "src_address", "dst_address",
+	     "encap_vrf_id", "decap_next_index", "teid", "tteid",
+	     "mcast_sw_if_index");
     }
 
   /* Get list of gtpu-tunnel interfaces */
@@ -428,8 +491,11 @@ api_gtpu_tunnel_dump (vat_main_t * vam)
 
   S (mp);
 
-  W (ret);
-  return ret;
+  /* No status response for this API call.
+   * Wait 1 sec for any dump output before return to vat# */
+  sleep (1);
+  
+  return 0;
 }
 
 #include <gtpu/gtpu.api_test.c>