gre: Multi-point interfaces

Type: feature

Change-Id: I0129ad6ace44a50a8a3b26db8e445cd06b2b49e8
Signed-off-by: Neale Ranns <nranns@cisco.com>

5 files changed, 239 insertions, 119 deletions

diff --git a/src/vnet/gre/gre.api b/src/vnet/gre/gre.api
index cb0bb736c4f..d79beebb94d 100644
--- a/src/vnet/gre/gre.api
+++ b/src/vnet/gre/gre.api
@@ -14,20 +14,30 @@
  * 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 A GRE tunnel type
 */
-enum gre_tunnel_type
+enum gre_tunnel_type : u8
 {
   GRE_API_TUNNEL_TYPE_L3 = 0,
   GRE_API_TUNNEL_TYPE_TEB,
   GRE_API_TUNNEL_TYPE_ERSPAN,
 };
 
+/** \brief A GRE tunnel mode
+*/
+enum gre_tunnel_mode : u8
+{
+  /* point-to-point */
+  GRE_API_TUNNEL_MODE_P2P,
+  /* multi-point */
+  GRE_API_TUNNEL_MODE_MP,
+};
+
 /** \brief A GRE tunnel
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
@@ -35,18 +45,17 @@ enum gre_tunnel_type
     @param instance - optional unique custom device instance, else ~0.
     @param src - Source IP address
     @param dst - Destination IP address, can be multicast
-    @param outer_fib_id - Encap FIB table ID
+    @param outer_table_id - Encap FIB table ID
     @param session_id - session for ERSPAN tunnel, range 0-1023
     @param sw_if_index - ignored on create/delete, present in details.
 */
 typedef gre_tunnel
 {
-  u32 client_index;
-  u32 context;
-  u16 session_id;
   vl_api_gre_tunnel_type_t type;
+  vl_api_gre_tunnel_mode_t mode;
+  u16 session_id;
   u32 instance;
-  u32 outer_fib_id;
+  u32 outer_table_id;
   vl_api_interface_index_t sw_if_index;
   vl_api_address_t src;
   vl_api_address_t dst;
diff --git a/src/vnet/gre/gre.c b/src/vnet/gre/gre.c
index 4f16b5db387..f06f19fab2a 100644
--- a/src/vnet/gre/gre.c
+++ b/src/vnet/gre/gre.c
@@ -18,6 +18,7 @@
 #include <vnet/vnet.h>
 #include <vnet/gre/gre.h>
 #include <vnet/adj/adj_midchain.h>
+#include <vnet/nhrp/nhrp.h>
 
 extern gre_main_t gre_main;
 
@@ -213,6 +214,7 @@ gre_build_rewrite (vnet_main_t * vnm,
 		   vnet_link_t link_type, const void *dst_address)
 {
   gre_main_t *gm = &gre_main;
+  const ip46_address_t *dst;
   ip4_and_gre_header_t *h4;
   ip6_and_gre_header_t *h6;
   gre_header_t *gre;
@@ -221,6 +223,7 @@ gre_build_rewrite (vnet_main_t * vnm,
   u32 ti;
   u8 is_ipv6;
 
+  dst = dst_address;
   ti = gm->tunnel_index_by_sw_if_index[sw_if_index];
 
   if (~0 == ti)
@@ -241,7 +244,7 @@ gre_build_rewrite (vnet_main_t * vnm,
       h4->ip4.protocol = IP_PROTOCOL_GRE;
       /* fixup ip4 header length and checksum after-the-fact */
       h4->ip4.src_address.as_u32 = t->tunnel_src.ip4.as_u32;
-      h4->ip4.dst_address.as_u32 = t->tunnel_dst.fp_addr.ip4.as_u32;
+      h4->ip4.dst_address.as_u32 = dst->ip4.as_u32;
       h4->ip4.checksum = ip4_header_checksum (&h4->ip4);
     }
   else
@@ -256,8 +259,8 @@ gre_build_rewrite (vnet_main_t * vnm,
       /* fixup ip6 header length and checksum after-the-fact */
       h6->ip6.src_address.as_u64[0] = t->tunnel_src.ip6.as_u64[0];
       h6->ip6.src_address.as_u64[1] = t->tunnel_src.ip6.as_u64[1];
-      h6->ip6.dst_address.as_u64[0] = t->tunnel_dst.fp_addr.ip6.as_u64[0];
-      h6->ip6.dst_address.as_u64[1] = t->tunnel_dst.fp_addr.ip6.as_u64[1];
+      h6->ip6.dst_address.as_u64[0] = dst->ip6.as_u64[0];
+      h6->ip6.dst_address.as_u64[1] = dst->ip6.as_u64[1];
     }
 
   if (PREDICT_FALSE (t->type == GRE_TUNNEL_TYPE_ERSPAN))
@@ -322,10 +325,51 @@ gre_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
 
   adj_nbr_midchain_update_rewrite
     (ai, !is_ipv6 ? gre4_fixup : gre6_fixup, NULL, af,
-     gre_build_rewrite (vnm, sw_if_index, adj_get_link_type (ai), NULL));
+     gre_build_rewrite (vnm, sw_if_index, adj_get_link_type (ai),
+			&t->tunnel_dst.fp_addr));
 
   gre_tunnel_stack (ai);
 }
+
+static adj_walk_rc_t
+mgre_mk_complete_walk (adj_index_t ai, void *ctx)
+{
+  nhrp_entry_adj_stack (ctx, ai);
+
+  return (ADJ_WALK_RC_CONTINUE);
+}
+
+void
+mgre_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
+{
+  gre_main_t *gm = &gre_main;
+  ip_adjacency_t *adj;
+  nhrp_entry_t *ne;
+  gre_tunnel_t *t;
+  adj_flags_t af;
+  u8 is_ipv6;
+  u32 ti;
+
+  adj = adj_get (ai);
+  ti = gm->tunnel_index_by_sw_if_index[sw_if_index];
+  t = pool_elt_at_index (gm->tunnels, ti);
+  is_ipv6 = t->tunnel_dst.fp_proto == FIB_PROTOCOL_IP6 ? 1 : 0;
+  af = ADJ_FLAG_MIDCHAIN_IP_STACK;
+
+  adj_nbr_midchain_update_rewrite
+    (ai, !is_ipv6 ? gre4_fixup : gre6_fixup, NULL, af,
+     gre_build_rewrite (vnm, sw_if_index, adj_get_link_type (ai),
+			&adj->sub_type.nbr.next_hop));
+
+  ne = nhrp_entry_find (sw_if_index, &adj->sub_type.nbr.next_hop);
+
+  if (NULL == ne)
+    // no NHRP entry to provide the next-hop
+    return;
+
+  adj_nbr_walk_nh (sw_if_index, t->tunnel_dst.fp_proto,
+		   &adj->sub_type.nbr.next_hop, mgre_mk_complete_walk, ne);
+}
 #endif /* CLIB_MARCH_VARIANT */
 
 typedef enum
@@ -574,6 +618,15 @@ VNET_HW_INTERFACE_CLASS (gre_hw_interface_class) = {
   .update_adjacency = gre_update_adj,
   .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
 };
+
+VNET_HW_INTERFACE_CLASS (mgre_hw_interface_class) = {
+  .name = "mGRE",
+  .format_header = format_gre_header_with_length,
+  .unformat_header = unformat_gre_header,
+  .build_rewrite = gre_build_rewrite,
+  .update_adjacency = mgre_update_adj,
+  .flags = VNET_HW_INTERFACE_CLASS_FLAG_NBMA,
+};
 /* *INDENT-ON* */
 #endif /* CLIB_MARCH_VARIANT */
 
diff --git a/src/vnet/gre/gre.h b/src/vnet/gre/gre.h
index 99fe4ace5b4..11bcddd51b3 100644
--- a/src/vnet/gre/gre.h
+++ b/src/vnet/gre/gre.h
@@ -26,6 +26,7 @@
 #include <vnet/adj/adj_types.h>
 
 extern vnet_hw_interface_class_t gre_hw_interface_class;
+extern vnet_hw_interface_class_t mgre_hw_interface_class;
 
 typedef enum
 {
@@ -36,34 +37,42 @@ typedef enum
 } gre_error_t;
 
 /**
+ * L3: GRE (i.e. this tunnel is in L3 mode)
+ * TEB: Transparent Ethernet Bridging - the tunnel is in L2 mode
+ * ERSPAN: type 2 - the tunnel is for port mirror SPAN output. Each tunnel is
+ *         associated with a session ID and expected to be used for encap
+ *         and output of mirrored packet from a L2 network only. There is
+ *         no support for receiving ERSPAN packets from a GRE ERSPAN tunnel
+ */
+#define foreach_gre_tunnel_type \
+  _(L3, "L3")                   \
+  _(TEB, "TEB")                 \
+  _(ERSPAN, "ERSPAN")           \
+
+/**
  * @brief The GRE tunnel type
  */
 typedef enum gre_tunnel_type_t_
 {
-  /**
-   * L3 GRE (i.e. this tunnel is in L3 mode)
-   */
-  GRE_TUNNEL_TYPE_L3 = 0,
-  /**
-   * Transparent Ethernet Bridging - the tunnel is in L2 mode
-   */
-  GRE_TUNNEL_TYPE_TEB = 1,
-  /**
-   * ERSPAN type 2 - the tunnel is for port mirror SPAN output. Each tunnel is
-   * associated with a session ID and expected to be used for encap and output
-   * of mirrored packet from a L2 network only. There is no support for
-   * receiving ERSPAN packets from a GRE ERSPAN tunnel in VPP.
-   */
-  GRE_TUNNEL_TYPE_ERSPAN = 2,
-} gre_tunnel_type_t;
+#define _(n, s) GRE_TUNNEL_TYPE_##n,
+  foreach_gre_tunnel_type
+#undef _
+} __clib_packed gre_tunnel_type_t;
 
-#define GRE_TUNNEL_TYPE_N (GRE_TUNNEL_TYPE_ERSPAN + 1)
+extern u8 *format_gre_tunnel_type (u8 * s, va_list * args);
 
-#define GRE_TUNNEL_TYPE_NAMES {    \
-    [GRE_TUNNEL_TYPE_L3] = "L3",   \
-    [GRE_TUNNEL_TYPE_TEB] = "TEB", \
-    [GRE_TUNNEL_TYPE_ERSPAN] = "ERSPAN", \
-}
+#define foreach_gre_tunnel_mode \
+  _(P2P, "point-to-point")      \
+  _(MP, "multi-point")          \
+
+typedef enum gre_tunnel_mode_t_
+{
+#define _(n, s) GRE_TUNNEL_MODE_##n,
+  foreach_gre_tunnel_mode
+#undef _
+} __clib_packed gre_tunnel_mode_t;
+
+extern u8 *format_gre_tunnel_mode (u8 * s, va_list * args);
 
 /**
  * A GRE payload protocol registration
@@ -201,6 +210,7 @@ typedef struct
   u32 hw_if_index;
   u32 sw_if_index;
   gre_tunnel_type_t type;
+  gre_tunnel_mode_t mode;
 
   /**
    * an L2 tunnel always rquires an L2 midchain. cache here for DP.
@@ -348,10 +358,11 @@ typedef struct
 {
   u8 is_add;
   gre_tunnel_type_t type;
+  gre_tunnel_mode_t mode;
   u8 is_ipv6;
   u32 instance;
   ip46_address_t src, dst;
-  u32 outer_fib_id;
+  u32 outer_table_id;
   u16 session_id;
 } vnet_gre_tunnel_add_del_args_t;
 
diff --git a/src/vnet/gre/gre_api.c b/src/vnet/gre/gre_api.c
index 0d6c33bfda6..9ee9f19f99f 100644
--- a/src/vnet/gre/gre_api.c
+++ b/src/vnet/gre/gre_api.c
@@ -52,19 +52,14 @@ _(GRE_TUNNEL_DUMP, gre_tunnel_dump)
 static int
 gre_tunnel_type_decode (vl_api_gre_tunnel_type_t in, gre_tunnel_type_t * out)
 {
-  in = clib_net_to_host_u32 (in);
-
   switch (in)
     {
-    case GRE_API_TUNNEL_TYPE_L3:
-      *out = GRE_TUNNEL_TYPE_L3;
-      return (0);
-    case GRE_API_TUNNEL_TYPE_TEB:
-      *out = GRE_TUNNEL_TYPE_TEB;
-      return (0);
-    case GRE_API_TUNNEL_TYPE_ERSPAN:
-      *out = GRE_TUNNEL_TYPE_ERSPAN;
-      return (0);
+#define _(n, v)                                           \
+      case GRE_API_TUNNEL_TYPE_##n:                       \
+        *out = GRE_TUNNEL_TYPE_##n;                       \
+        return (0);
+      foreach_gre_tunnel_type
+#undef _
     }
 
   return (VNET_API_ERROR_INVALID_VALUE);
@@ -77,18 +72,47 @@ gre_tunnel_type_encode (gre_tunnel_type_t in)
 
   switch (in)
     {
-    case GRE_TUNNEL_TYPE_L3:
-      out = GRE_API_TUNNEL_TYPE_L3;
-      break;
-    case GRE_TUNNEL_TYPE_TEB:
-      out = GRE_API_TUNNEL_TYPE_TEB;
-      break;
-    case GRE_TUNNEL_TYPE_ERSPAN:
-      out = GRE_API_TUNNEL_TYPE_ERSPAN;
-      break;
+#define _(n, v)                                           \
+      case GRE_TUNNEL_TYPE_##n:                           \
+        out = GRE_API_TUNNEL_TYPE_##n;                    \
+        break;
+      foreach_gre_tunnel_type
+#undef _
+    }
+
+  return (out);
+}
+
+static int
+gre_tunnel_mode_decode (vl_api_gre_tunnel_mode_t in, gre_tunnel_mode_t * out)
+{
+  switch (in)
+    {
+#define _(n, v)                                           \
+      case GRE_API_TUNNEL_MODE_##n:                       \
+        *out = GRE_TUNNEL_MODE_##n;                       \
+        return (0);
+      foreach_gre_tunnel_mode
+#undef _
     }
 
-  out = clib_net_to_host_u32 (out);
+  return (VNET_API_ERROR_INVALID_VALUE_2);
+}
+
+static vl_api_gre_tunnel_mode_t
+gre_tunnel_mode_encode (gre_tunnel_mode_t in)
+{
+  vl_api_gre_tunnel_mode_t out = GRE_API_TUNNEL_MODE_P2P;
+
+  switch (in)
+    {
+#define _(n, v)                                           \
+      case GRE_TUNNEL_MODE_##n:                           \
+        out = GRE_API_TUNNEL_MODE_##n;                    \
+        break;
+      foreach_gre_tunnel_mode
+#undef _
+    }
 
   return (out);
 }
@@ -122,11 +146,16 @@ static void vl_api_gre_tunnel_add_del_t_handler
   if (rv)
     goto out;
 
+  rv = gre_tunnel_mode_decode (mp->tunnel.mode, &a->mode);
+
+  if (rv)
+    goto out;
+
   a->is_add = mp->is_add;
   a->is_ipv6 = (itype[0] == IP46_TYPE_IP6);
   a->instance = ntohl (mp->tunnel.instance);
   a->session_id = ntohs (mp->tunnel.session_id);
-  a->outer_fib_id = ntohl (mp->tunnel.outer_fib_id);
+  a->outer_table_id = ntohl (mp->tunnel.outer_table_id);
 
   rv = vnet_gre_tunnel_add_del (a, &sw_if_index);
 
@@ -151,14 +180,16 @@ static void send_gre_tunnel_details
   ip_address_encode (&t->tunnel_src, IP46_TYPE_ANY, &rmp->tunnel.src);
   ip_address_encode (&t->tunnel_dst.fp_addr, IP46_TYPE_ANY, &rmp->tunnel.dst);
 
-  rmp->tunnel.outer_fib_id =
+  rmp->tunnel.outer_table_id =
     htonl (fib_table_get_table_id
 	   (t->outer_fib_index, t->tunnel_dst.fp_proto));
 
   rmp->tunnel.type = gre_tunnel_type_encode (t->type);
+  rmp->tunnel.mode = gre_tunnel_mode_encode (t->mode);
   rmp->tunnel.instance = htonl (t->user_instance);
   rmp->tunnel.sw_if_index = htonl (t->sw_if_index);
   rmp->tunnel.session_id = htons (t->session_id);
+
   rmp->context = context;
 
   vl_api_send_msg (reg, (u8 *) rmp);
diff --git a/src/vnet/gre/interface.c b/src/vnet/gre/interface.c
index ea93536fb27..927f34ef694 100644
--- a/src/vnet/gre/interface.c
+++ b/src/vnet/gre/interface.c
@@ -26,7 +26,39 @@
 #include <vnet/mpls/mpls.h>
 #include <vnet/l2/l2_input.h>
 
-static const char *gre_tunnel_type_names[] = GRE_TUNNEL_TYPE_NAMES;
+u8 *
+format_gre_tunnel_type (u8 * s, va_list * args)
+{
+  gre_tunnel_type_t type = va_arg (*args, int);
+
+  switch (type)
+    {
+#define _(n, v) case GRE_TUNNEL_TYPE_##n:       \
+      s = format (s, "%s", v);                  \
+      break;
+      foreach_gre_tunnel_type
+#undef _
+    }
+
+  return (s);
+}
+
+u8 *
+format_gre_tunnel_mode (u8 * s, va_list * args)
+{
+  gre_tunnel_mode_t mode = va_arg (*args, int);
+
+  switch (mode)
+    {
+#define _(n, v) case GRE_TUNNEL_MODE_##n:       \
+      s = format (s, "%s", v);                  \
+      break;
+      foreach_gre_tunnel_mode
+#undef _
+    }
+
+  return (s);
+}
 
 static u8 *
 format_gre_tunnel (u8 * s, va_list * args)
@@ -39,7 +71,8 @@ format_gre_tunnel (u8 * s, va_list * args)
 	      format_ip46_address, &t->tunnel_dst.fp_addr, IP46_TYPE_ANY,
 	      t->outer_fib_index, t->sw_if_index);
 
-  s = format (s, "payload %s ", gre_tunnel_type_names[t->type]);
+  s = format (s, "payload %U ", format_gre_tunnel_type, t->type);
+  s = format (s, "%U ", format_gre_tunnel_mode, t->mode);
 
   if (t->type == GRE_TUNNEL_TYPE_ERSPAN)
     s = format (s, "session %d ", t->session_id);
@@ -209,13 +242,21 @@ vnet_gre_tunnel_add (vnet_gre_tunnel_add_del_args_t * a,
   t->user_instance = u_idx;	/* name */
 
   t->type = a->type;
+  t->mode = a->mode;
   if (t->type == GRE_TUNNEL_TYPE_ERSPAN)
     t->session_id = a->session_id;
 
   if (t->type == GRE_TUNNEL_TYPE_L3)
-    hw_if_index = vnet_register_interface (vnm, gre_device_class.index, t_idx,
-					   gre_hw_interface_class.index,
-					   t_idx);
+    {
+      if (t->mode == GRE_TUNNEL_MODE_P2P)
+	hw_if_index =
+	  vnet_register_interface (vnm, gre_device_class.index, t_idx,
+				   gre_hw_interface_class.index, t_idx);
+      else
+	hw_if_index =
+	  vnet_register_interface (vnm, gre_device_class.index, t_idx,
+				   mgre_hw_interface_class.index, t_idx);
+    }
   else
     {
       /* Default MAC address (d00b:eed0:0000 + sw_if_index) */
@@ -372,9 +413,9 @@ vnet_gre_tunnel_add_del (vnet_gre_tunnel_add_del_args_t * a,
   u32 outer_fib_index;
 
   if (!a->is_ipv6)
-    outer_fib_index = ip4_fib_index_from_table_id (a->outer_fib_id);
+    outer_fib_index = ip4_fib_index_from_table_id (a->outer_table_id);
   else
-    outer_fib_index = ip6_fib_index_from_table_id (a->outer_fib_id);
+    outer_fib_index = ip6_fib_index_from_table_id (a->outer_table_id);
 
   if (~0 == outer_fib_index)
     return VNET_API_ERROR_NO_SUCH_FIB;
@@ -428,18 +469,17 @@ create_gre_tunnel_command_fn (vlib_main_t * vm,
 {
   unformat_input_t _line_input, *line_input = &_line_input;
   vnet_gre_tunnel_add_del_args_t _a, *a = &_a;
-  ip46_address_t src, dst;
+  ip46_address_t src = ip46_address_initializer, dst =
+    ip46_address_initializer;
   u32 instance = ~0;
-  u32 outer_fib_id = 0;
+  u32 outer_table_id = 0;
   gre_tunnel_type_t t_type = GRE_TUNNEL_TYPE_L3;
+  gre_tunnel_mode_t t_mode = GRE_TUNNEL_MODE_P2P;
   u32 session_id = 0;
   int rv;
-  u32 num_m_args = 0;
   u8 is_add = 1;
   u32 sw_if_index;
   clib_error_t *error = NULL;
-  u8 ipv4_set = 0;
-  u8 ipv6_set = 0;
 
   /* Get a line of input. */
   if (!unformat_user (input, unformat_line_input, line_input))
@@ -451,32 +491,14 @@ create_gre_tunnel_command_fn (vlib_main_t * vm,
 	is_add = 0;
       else if (unformat (line_input, "instance %d", &instance))
 	;
-      else
-	if (unformat (line_input, "src %U", unformat_ip4_address, &src.ip4))
-	{
-	  num_m_args++;
-	  ipv4_set = 1;
-	}
-      else
-	if (unformat (line_input, "dst %U", unformat_ip4_address, &dst.ip4))
-	{
-	  num_m_args++;
-	  ipv4_set = 1;
-	}
-      else
-	if (unformat (line_input, "src %U", unformat_ip6_address, &src.ip6))
-	{
-	  num_m_args++;
-	  ipv6_set = 1;
-	}
-      else
-	if (unformat (line_input, "dst %U", unformat_ip6_address, &dst.ip6))
-	{
-	  num_m_args++;
-	  ipv6_set = 1;
-	}
-      else if (unformat (line_input, "outer-fib-id %d", &outer_fib_id))
+      else if (unformat (line_input, "src %U", unformat_ip46_address, &src))
+	;
+      else if (unformat (line_input, "dst %U", unformat_ip46_address, &dst))
 	;
+      else if (unformat (line_input, "outer-table-id %d", &outer_table_id))
+	;
+      else if (unformat (line_input, "multipoint"))
+	t_mode = GRE_TUNNEL_MODE_MP;
       else if (unformat (line_input, "teb"))
 	t_type = GRE_TUNNEL_TYPE_TEB;
       else if (unformat (line_input, "erspan %d", &session_id))
@@ -489,47 +511,41 @@ create_gre_tunnel_command_fn (vlib_main_t * vm,
 	}
     }
 
-  if (num_m_args < 2)
+  if (ip46_address_is_equal (&src, &dst))
     {
-      error = clib_error_return (0, "mandatory argument(s) missing");
+      error = clib_error_return (0, "src and dst are identical");
       goto done;
     }
 
-  if ((ipv4_set && memcmp (&src.ip4, &dst.ip4, sizeof (src.ip4)) == 0) ||
-      (ipv6_set && memcmp (&src.ip6, &dst.ip6, sizeof (src.ip6)) == 0))
+  if (t_mode != GRE_TUNNEL_MODE_MP && ip46_address_is_zero (&dst))
     {
-      error = clib_error_return (0, "src and dst are identical");
+      error = clib_error_return (0, "destination address not specified");
       goto done;
     }
 
-  if (ipv4_set && ipv6_set)
-    return clib_error_return (0, "both IPv4 and IPv6 addresses specified");
+  if (ip46_address_is_zero (&src))
+    {
+      error = clib_error_return (0, "source address not specified");
+      goto done;
+    }
 
-  if ((ipv4_set && memcmp (&dst.ip4, &zero_addr.ip4, sizeof (dst.ip4)) == 0)
-      || (ipv6_set
-	  && memcmp (&dst.ip6, &zero_addr.ip6, sizeof (dst.ip6)) == 0))
+  if (ip46_address_is_ip4 (&src) != ip46_address_is_ip4 (&dst))
     {
-      error = clib_error_return (0, "dst address cannot be zero");
+      error =
+	clib_error_return (0, "src and dst address must be the same AF");
       goto done;
     }
 
   clib_memset (a, 0, sizeof (*a));
   a->is_add = is_add;
-  a->outer_fib_id = outer_fib_id;
+  a->outer_table_id = outer_table_id;
   a->type = t_type;
+  a->mode = t_mode;
   a->session_id = session_id;
-  a->is_ipv6 = ipv6_set;
+  a->is_ipv6 = !ip46_address_is_ip4 (&src);
   a->instance = instance;
-  if (!ipv6_set)
-    {
-      clib_memcpy (&a->src.ip4, &src.ip4, sizeof (src.ip4));
-      clib_memcpy (&a->dst.ip4, &dst.ip4, sizeof (dst.ip4));
-    }
-  else
-    {
-      clib_memcpy (&a->src.ip6, &src.ip6, sizeof (src.ip6));
-      clib_memcpy (&a->dst.ip6, &dst.ip6, sizeof (dst.ip6));
-    }
+  clib_memcpy (&a->src, &src, sizeof (a->src));
+  clib_memcpy (&a->dst, &dst, sizeof (a->dst));
 
   rv = vnet_gre_tunnel_add_del (a, &sw_if_index);
 
@@ -543,8 +559,8 @@ create_gre_tunnel_command_fn (vlib_main_t * vm,
       error = clib_error_return (0, "GRE tunnel already exists...");
       goto done;
     case VNET_API_ERROR_NO_SUCH_FIB:
-      error = clib_error_return (0, "outer fib ID %d doesn't exist\n",
-				 outer_fib_id);
+      error = clib_error_return (0, "outer table ID %d doesn't exist\n",
+				 outer_table_id);
       goto done;
     case VNET_API_ERROR_NO_SUCH_ENTRY:
       error = clib_error_return (0, "GRE tunnel doesn't exist");