gre: move to a plugin

Move GRE folder under vnet to the plugin folder, and modify some of path
of the #inlude<header> to the new path.

Add a plugin.c file to register a plugin.

JIRA: VPP-2044

Type: improvement
Change-Id: I7f64cecd97538a7492e56a41558dab58281a9fa5
Signed-off-by: Chuhao Tang <nicotang@cisco.com>

1 files changed, 832 insertions, 0 deletions

diff --git a/src/plugins/gre/interface.c b/src/plugins/gre/interface.c
new file mode 100644
index 00000000000..8d93ebd0cf5
--- /dev/null
+++ b/src/plugins/gre/interface.c
@@ -0,0 +1,832 @@
+/*
+ * gre_interface.c: gre interfaces
+ *
+ * Copyright (c) 2012 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/vnet.h>
+#include <gre/gre.h>
+#include <vnet/ip/format.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/adj/adj_midchain.h>
+#include <vnet/adj/adj_nbr.h>
+#include <vnet/mpls/mpls.h>
+#include <vnet/l2/l2_input.h>
+#include <vnet/teib/teib.h>
+
+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);
+}
+
+static u8 *
+format_gre_tunnel (u8 *s, va_list *args)
+{
+  gre_tunnel_t *t = va_arg (*args, gre_tunnel_t *);
+
+  s = format (s, "[%d] instance %d src %U dst %U fib-idx %d sw-if-idx %d ",
+	      t->dev_instance, t->user_instance, format_ip46_address,
+	      &t->tunnel_src, IP46_TYPE_ANY, format_ip46_address,
+	      &t->tunnel_dst.fp_addr, IP46_TYPE_ANY, t->outer_fib_index,
+	      t->sw_if_index);
+
+  s = format (s, "payload %U ", format_gre_tunnel_type, t->type);
+  s = format (s, "%U ", format_tunnel_mode, t->mode);
+
+  if (t->type == GRE_TUNNEL_TYPE_ERSPAN)
+    s = format (s, "session %d ", t->session_id);
+
+  if (t->type != GRE_TUNNEL_TYPE_L3)
+    s = format (s, "l2-adj-idx %d ", t->l2_adj_index);
+
+  return s;
+}
+
+static gre_tunnel_t *
+gre_tunnel_db_find (const vnet_gre_tunnel_add_del_args_t *a,
+		    u32 outer_fib_index, gre_tunnel_key_t *key)
+{
+  gre_main_t *gm = &gre_main;
+  uword *p;
+
+  if (!a->is_ipv6)
+    {
+      gre_mk_key4 (a->src.ip4, a->dst.ip4, outer_fib_index, a->type, a->mode,
+		   a->session_id, &key->gtk_v4);
+      p = hash_get_mem (gm->tunnel_by_key4, &key->gtk_v4);
+    }
+  else
+    {
+      gre_mk_key6 (&a->src.ip6, &a->dst.ip6, outer_fib_index, a->type, a->mode,
+		   a->session_id, &key->gtk_v6);
+      p = hash_get_mem (gm->tunnel_by_key6, &key->gtk_v6);
+    }
+
+  if (NULL == p)
+    return (NULL);
+
+  return (pool_elt_at_index (gm->tunnels, p[0]));
+}
+
+static void
+gre_tunnel_db_add (gre_tunnel_t *t, gre_tunnel_key_t *key)
+{
+  gre_main_t *gm = &gre_main;
+
+  if (t->tunnel_dst.fp_proto == FIB_PROTOCOL_IP6)
+    {
+      hash_set_mem_alloc (&gm->tunnel_by_key6, &key->gtk_v6, t->dev_instance);
+    }
+  else
+    {
+      hash_set_mem_alloc (&gm->tunnel_by_key4, &key->gtk_v4, t->dev_instance);
+    }
+}
+
+static void
+gre_tunnel_db_remove (gre_tunnel_t *t, gre_tunnel_key_t *key)
+{
+  gre_main_t *gm = &gre_main;
+
+  if (t->tunnel_dst.fp_proto == FIB_PROTOCOL_IP6)
+    {
+      hash_unset_mem_free (&gm->tunnel_by_key6, &key->gtk_v6);
+    }
+  else
+    {
+      hash_unset_mem_free (&gm->tunnel_by_key4, &key->gtk_v4);
+    }
+}
+
+/**
+ * gre_tunnel_stack
+ *
+ * 'stack' (resolve the recursion for) the tunnel's midchain adjacency
+ */
+void
+gre_tunnel_stack (adj_index_t ai)
+{
+  gre_main_t *gm = &gre_main;
+  ip_adjacency_t *adj;
+  gre_tunnel_t *gt;
+  u32 sw_if_index;
+
+  adj = adj_get (ai);
+  sw_if_index = adj->rewrite_header.sw_if_index;
+
+  if ((vec_len (gm->tunnel_index_by_sw_if_index) <= sw_if_index) ||
+      (~0 == gm->tunnel_index_by_sw_if_index[sw_if_index]))
+    return;
+
+  gt = pool_elt_at_index (gm->tunnels,
+			  gm->tunnel_index_by_sw_if_index[sw_if_index]);
+
+  if ((vnet_hw_interface_get_flags (vnet_get_main (), gt->hw_if_index) &
+       VNET_HW_INTERFACE_FLAG_LINK_UP) == 0)
+    {
+      adj_midchain_delegate_unstack (ai);
+    }
+  else
+    {
+      adj_midchain_delegate_stack (ai, gt->outer_fib_index, &gt->tunnel_dst);
+    }
+}
+
+/**
+ * mgre_tunnel_stack
+ *
+ * 'stack' (resolve the recursion for) the tunnel's midchain adjacency
+ */
+static void
+mgre_tunnel_stack (adj_index_t ai)
+{
+  gre_main_t *gm = &gre_main;
+  const ip_adjacency_t *adj;
+  const gre_tunnel_t *gt;
+  u32 sw_if_index;
+
+  adj = adj_get (ai);
+  sw_if_index = adj->rewrite_header.sw_if_index;
+
+  if ((vec_len (gm->tunnel_index_by_sw_if_index) <= sw_if_index) ||
+      (~0 == gm->tunnel_index_by_sw_if_index[sw_if_index]))
+    return;
+
+  gt = pool_elt_at_index (gm->tunnels,
+			  gm->tunnel_index_by_sw_if_index[sw_if_index]);
+
+  if ((vnet_hw_interface_get_flags (vnet_get_main (), gt->hw_if_index) &
+       VNET_HW_INTERFACE_FLAG_LINK_UP) == 0)
+    {
+      adj_midchain_delegate_unstack (ai);
+    }
+  else
+    {
+      const teib_entry_t *ne;
+
+      ne = teib_entry_find_46 (sw_if_index, adj->ia_nh_proto,
+			       &adj->sub_type.nbr.next_hop);
+      if (NULL != ne)
+	teib_entry_adj_stack (ne, ai);
+    }
+}
+
+/**
+ * @brief Call back when restacking all adjacencies on a GRE interface
+ */
+static adj_walk_rc_t
+gre_adj_walk_cb (adj_index_t ai, void *ctx)
+{
+  gre_tunnel_stack (ai);
+
+  return (ADJ_WALK_RC_CONTINUE);
+}
+static adj_walk_rc_t
+mgre_adj_walk_cb (adj_index_t ai, void *ctx)
+{
+  mgre_tunnel_stack (ai);
+
+  return (ADJ_WALK_RC_CONTINUE);
+}
+
+static void
+gre_tunnel_restack (gre_tunnel_t *gt)
+{
+  fib_protocol_t proto;
+
+  /*
+   * walk all the adjacencies on th GRE interface and restack them
+   */
+  FOR_EACH_FIB_IP_PROTOCOL (proto)
+  {
+    switch (gt->mode)
+      {
+      case TUNNEL_MODE_P2P:
+	adj_nbr_walk (gt->sw_if_index, proto, gre_adj_walk_cb, NULL);
+	break;
+      case TUNNEL_MODE_MP:
+	adj_nbr_walk (gt->sw_if_index, proto, mgre_adj_walk_cb, NULL);
+	break;
+      }
+  }
+}
+
+static void
+gre_teib_mk_key (const gre_tunnel_t *t, const teib_entry_t *ne,
+		 gre_tunnel_key_t *key)
+{
+  const fib_prefix_t *nh;
+
+  nh = teib_entry_get_nh (ne);
+
+  /* construct the key using mode P2P so it can be found in the DP */
+  if (FIB_PROTOCOL_IP4 == nh->fp_proto)
+    gre_mk_key4 (t->tunnel_src.ip4, nh->fp_addr.ip4,
+		 teib_entry_get_fib_index (ne), t->type, TUNNEL_MODE_P2P, 0,
+		 &key->gtk_v4);
+  else
+    gre_mk_key6 (&t->tunnel_src.ip6, &nh->fp_addr.ip6,
+		 teib_entry_get_fib_index (ne), t->type, TUNNEL_MODE_P2P, 0,
+		 &key->gtk_v6);
+}
+
+/**
+ * An TEIB entry has been added
+ */
+static void
+gre_teib_entry_added (const teib_entry_t *ne)
+{
+  gre_main_t *gm = &gre_main;
+  const ip_address_t *nh;
+  gre_tunnel_key_t key;
+  gre_tunnel_t *t;
+  u32 sw_if_index;
+  u32 t_idx;
+
+  sw_if_index = teib_entry_get_sw_if_index (ne);
+  if (vec_len (gm->tunnel_index_by_sw_if_index) < sw_if_index)
+    return;
+
+  t_idx = gm->tunnel_index_by_sw_if_index[sw_if_index];
+
+  if (INDEX_INVALID == t_idx)
+    return;
+
+  /* entry has been added on an interface for which there is a GRE tunnel */
+  t = pool_elt_at_index (gm->tunnels, t_idx);
+
+  if (t->mode != TUNNEL_MODE_MP)
+    return;
+
+  /* the next-hop (underlay) of the NHRP entry will form part of the key for
+   * ingress lookup to match packets to this interface */
+  gre_teib_mk_key (t, ne, &key);
+  gre_tunnel_db_add (t, &key);
+
+  /* update the rewrites for each of the adjacencies for this peer (overlay)
+   * using  the next-hop (underlay) */
+  mgre_walk_ctx_t ctx = { .t = t, .ne = ne };
+  nh = teib_entry_get_peer (ne);
+  adj_nbr_walk_nh (
+    teib_entry_get_sw_if_index (ne),
+    (AF_IP4 == ip_addr_version (nh) ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6),
+    &ip_addr_46 (nh), mgre_mk_complete_walk, &ctx);
+}
+
+static void
+gre_teib_entry_deleted (const teib_entry_t *ne)
+{
+  gre_main_t *gm = &gre_main;
+  const ip_address_t *nh;
+  gre_tunnel_key_t key;
+  gre_tunnel_t *t;
+  u32 sw_if_index;
+  u32 t_idx;
+
+  sw_if_index = teib_entry_get_sw_if_index (ne);
+  if (vec_len (gm->tunnel_index_by_sw_if_index) < sw_if_index)
+    return;
+
+  t_idx = gm->tunnel_index_by_sw_if_index[sw_if_index];
+
+  if (INDEX_INVALID == t_idx)
+    return;
+
+  t = pool_elt_at_index (gm->tunnels, t_idx);
+
+  /* remove the next-hop as an ingress lookup key */
+  gre_teib_mk_key (t, ne, &key);
+  gre_tunnel_db_remove (t, &key);
+
+  nh = teib_entry_get_peer (ne);
+
+  /* make all the adjacencies incomplete */
+  adj_nbr_walk_nh (
+    teib_entry_get_sw_if_index (ne),
+    (AF_IP4 == ip_addr_version (nh) ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6),
+    &ip_addr_46 (nh), mgre_mk_incomplete_walk, t);
+}
+
+static walk_rc_t
+gre_tunnel_delete_teib_walk (index_t nei, void *ctx)
+{
+  gre_tunnel_t *t = ctx;
+  gre_tunnel_key_t key;
+
+  gre_teib_mk_key (t, teib_entry_get (nei), &key);
+  gre_tunnel_db_remove (t, &key);
+
+  return (WALK_CONTINUE);
+}
+
+static walk_rc_t
+gre_tunnel_add_teib_walk (index_t nei, void *ctx)
+{
+  gre_tunnel_t *t = ctx;
+  gre_tunnel_key_t key = {};
+
+  gre_teib_mk_key (t, teib_entry_get (nei), &key);
+  gre_tunnel_db_add (t, &key);
+
+  return (WALK_CONTINUE);
+}
+
+static int
+vnet_gre_tunnel_add (vnet_gre_tunnel_add_del_args_t *a, u32 outer_fib_index,
+		     u32 *sw_if_indexp)
+{
+  gre_main_t *gm = &gre_main;
+  vnet_main_t *vnm = gm->vnet_main;
+  gre_tunnel_t *t;
+  vnet_hw_interface_t *hi;
+  u32 hw_if_index, sw_if_index;
+  u8 is_ipv6 = a->is_ipv6;
+  gre_tunnel_key_t key;
+
+  t = gre_tunnel_db_find (a, outer_fib_index, &key);
+  if (NULL != t)
+    return VNET_API_ERROR_IF_ALREADY_EXISTS;
+
+  pool_get_aligned (gm->tunnels, t, CLIB_CACHE_LINE_BYTES);
+  clib_memset (t, 0, sizeof (*t));
+
+  /* Reconcile the real dev_instance and a possible requested instance */
+  u32 t_idx = t - gm->tunnels; /* tunnel index (or instance) */
+  u32 u_idx = a->instance;     /* user specified instance */
+  if (u_idx == ~0)
+    u_idx = t_idx;
+  if (hash_get (gm->instance_used, u_idx))
+    {
+      pool_put (gm->tunnels, t);
+      return VNET_API_ERROR_INSTANCE_IN_USE;
+    }
+  hash_set (gm->instance_used, u_idx, 1);
+
+  t->dev_instance = t_idx;  /* actual */
+  t->user_instance = u_idx; /* name */
+
+  t->type = a->type;
+  t->mode = a->mode;
+  t->flags = a->flags;
+  if (t->type == GRE_TUNNEL_TYPE_ERSPAN)
+    t->session_id = a->session_id;
+
+  if (t->type == GRE_TUNNEL_TYPE_L3)
+    {
+      if (t->mode == 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
+    {
+      vnet_eth_interface_registration_t eir = {};
+
+      /* Default MAC address (d00b:eed0:0000 + sw_if_index) */
+      u8 address[6] = {
+	0xd0, 0x0b, 0xee, 0xd0, (u8) (t_idx >> 8), (u8) t_idx
+      };
+
+      eir.dev_class_index = gre_device_class.index;
+      eir.dev_instance = t_idx;
+      eir.address = address;
+      hw_if_index = vnet_eth_register_interface (vnm, &eir);
+    }
+
+  /* Set GRE tunnel interface output node (not used for L3 payload) */
+  if (GRE_TUNNEL_TYPE_ERSPAN == t->type)
+    vnet_set_interface_output_node (vnm, hw_if_index,
+				    gre_erspan_encap_node.index);
+  else
+    vnet_set_interface_output_node (vnm, hw_if_index,
+				    gre_teb_encap_node.index);
+
+  hi = vnet_get_hw_interface (vnm, hw_if_index);
+  sw_if_index = hi->sw_if_index;
+
+  t->hw_if_index = hw_if_index;
+  t->outer_fib_index = outer_fib_index;
+  t->sw_if_index = sw_if_index;
+  t->l2_adj_index = ADJ_INDEX_INVALID;
+
+  vec_validate_init_empty (gm->tunnel_index_by_sw_if_index, sw_if_index, ~0);
+  gm->tunnel_index_by_sw_if_index[sw_if_index] = t_idx;
+
+  if (!is_ipv6)
+    {
+      hi->frame_overhead = sizeof (gre_header_t) + sizeof (ip4_header_t);
+      hi->min_frame_size = hi->frame_overhead + 64;
+    }
+  else
+    {
+      hi->frame_overhead = sizeof (gre_header_t) + sizeof (ip6_header_t);
+      hi->min_frame_size = hi->frame_overhead + 64;
+    }
+
+  /* Standard default gre MTU. */
+  vnet_sw_interface_set_mtu (vnm, sw_if_index, 9000);
+
+  /*
+   * source the FIB entry for the tunnel's destination
+   * and become a child thereof. The tunnel will then get poked
+   * when the forwarding for the entry updates, and the tunnel can
+   * re-stack accordingly
+   */
+
+  clib_memcpy (&t->tunnel_src, &a->src, sizeof (t->tunnel_src));
+  t->tunnel_dst.fp_len = !is_ipv6 ? 32 : 128;
+  t->tunnel_dst.fp_proto = !is_ipv6 ? FIB_PROTOCOL_IP4 : FIB_PROTOCOL_IP6;
+  t->tunnel_dst.fp_addr = a->dst;
+
+  gre_tunnel_db_add (t, &key);
+
+  if (t->mode == TUNNEL_MODE_MP)
+    teib_walk_itf (t->sw_if_index, gre_tunnel_add_teib_walk, t);
+
+  if (t->type == GRE_TUNNEL_TYPE_ERSPAN)
+    {
+      gre_sn_key_t skey;
+      gre_sn_t *gre_sn;
+
+      gre_mk_sn_key (t, &skey);
+      gre_sn = (gre_sn_t *) hash_get_mem (gm->seq_num_by_key, &skey);
+      if (gre_sn != NULL)
+	{
+	  gre_sn->ref_count++;
+	  t->gre_sn = gre_sn;
+	}
+      else
+	{
+	  gre_sn = clib_mem_alloc (sizeof (gre_sn_t));
+	  gre_sn->seq_num = 0;
+	  gre_sn->ref_count = 1;
+	  t->gre_sn = gre_sn;
+	  hash_set_mem_alloc (&gm->seq_num_by_key, &skey, (uword) gre_sn);
+	}
+    }
+
+  if (t->type != GRE_TUNNEL_TYPE_L3)
+    {
+      t->l2_adj_index = adj_nbr_add_or_lock (
+	t->tunnel_dst.fp_proto, VNET_LINK_ETHERNET, &zero_addr, sw_if_index);
+      vnet_set_interface_l3_output_node (gm->vlib_main, sw_if_index,
+					 (u8 *) "tunnel-output-no-count");
+      gre_update_adj (vnm, t->sw_if_index, t->l2_adj_index);
+    }
+  else
+    {
+      vnet_set_interface_l3_output_node (gm->vlib_main, sw_if_index,
+					 (u8 *) "tunnel-output");
+    }
+  if (sw_if_indexp)
+    *sw_if_indexp = sw_if_index;
+
+  /* register gre46-input nodes */
+  ip4_register_protocol (IP_PROTOCOL_GRE, gre4_input_node.index);
+  ip6_register_protocol (IP_PROTOCOL_GRE, gre6_input_node.index);
+
+  return 0;
+}
+
+static int
+vnet_gre_tunnel_delete (vnet_gre_tunnel_add_del_args_t *a, u32 outer_fib_index,
+			u32 *sw_if_indexp)
+{
+  gre_main_t *gm = &gre_main;
+  vnet_main_t *vnm = gm->vnet_main;
+  gre_tunnel_t *t;
+  gre_tunnel_key_t key;
+  u32 sw_if_index;
+
+  t = gre_tunnel_db_find (a, outer_fib_index, &key);
+  if (NULL == t)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  if (t->mode == TUNNEL_MODE_MP)
+    teib_walk_itf (t->sw_if_index, gre_tunnel_delete_teib_walk, t);
+
+  sw_if_index = t->sw_if_index;
+  vnet_sw_interface_set_flags (vnm, sw_if_index, 0 /* down */);
+
+  /* make sure tunnel is removed from l2 bd or xconnect */
+  set_int_l2_mode (gm->vlib_main, vnm, MODE_L3, sw_if_index, 0,
+		   L2_BD_PORT_TYPE_NORMAL, 0, 0);
+  gm->tunnel_index_by_sw_if_index[sw_if_index] = ~0;
+
+  if (t->type == GRE_TUNNEL_TYPE_L3)
+    vnet_delete_hw_interface (vnm, t->hw_if_index);
+  else
+    ethernet_delete_interface (vnm, t->hw_if_index);
+
+  if (t->l2_adj_index != ADJ_INDEX_INVALID)
+    {
+      adj_midchain_delegate_unstack (t->l2_adj_index);
+      adj_unlock (t->l2_adj_index);
+    }
+
+  ASSERT ((t->type != GRE_TUNNEL_TYPE_ERSPAN) || (t->gre_sn != NULL));
+  if ((t->type == GRE_TUNNEL_TYPE_ERSPAN) && (t->gre_sn->ref_count-- == 1))
+    {
+      gre_sn_key_t skey;
+      gre_mk_sn_key (t, &skey);
+      hash_unset_mem_free (&gm->seq_num_by_key, &skey);
+      clib_mem_free (t->gre_sn);
+    }
+
+  vnet_reset_interface_l3_output_node (gm->vlib_main, sw_if_index);
+  hash_unset (gm->instance_used, t->user_instance);
+  gre_tunnel_db_remove (t, &key);
+  pool_put (gm->tunnels, t);
+
+  if (sw_if_indexp)
+    *sw_if_indexp = sw_if_index;
+
+  return 0;
+}
+
+int
+vnet_gre_tunnel_add_del (vnet_gre_tunnel_add_del_args_t *a, u32 *sw_if_indexp)
+{
+  u32 outer_fib_index;
+
+  outer_fib_index = fib_table_find (
+    (a->is_ipv6 ? FIB_PROTOCOL_IP6 : FIB_PROTOCOL_IP4), a->outer_table_id);
+
+  if (~0 == outer_fib_index)
+    return VNET_API_ERROR_NO_SUCH_FIB;
+
+  if (a->session_id > GTK_SESSION_ID_MAX)
+    return VNET_API_ERROR_INVALID_SESSION_ID;
+
+  if (a->mode == TUNNEL_MODE_MP && !ip46_address_is_zero (&a->dst))
+    return (VNET_API_ERROR_INVALID_DST_ADDRESS);
+
+  if (a->is_add)
+    return (vnet_gre_tunnel_add (a, outer_fib_index, sw_if_indexp));
+  else
+    return (vnet_gre_tunnel_delete (a, outer_fib_index, sw_if_indexp));
+}
+
+clib_error_t *
+gre_interface_admin_up_down (vnet_main_t *vnm, u32 hw_if_index, u32 flags)
+{
+  gre_main_t *gm = &gre_main;
+  vnet_hw_interface_t *hi;
+  gre_tunnel_t *t;
+  u32 ti;
+
+  hi = vnet_get_hw_interface (vnm, hw_if_index);
+
+  if (NULL == gm->tunnel_index_by_sw_if_index ||
+      hi->sw_if_index >= vec_len (gm->tunnel_index_by_sw_if_index))
+    return (NULL);
+
+  ti = gm->tunnel_index_by_sw_if_index[hi->sw_if_index];
+
+  if (~0 == ti)
+    /* not one of ours */
+    return (NULL);
+
+  t = pool_elt_at_index (gm->tunnels, ti);
+
+  if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
+    vnet_hw_interface_set_flags (vnm, hw_if_index,
+				 VNET_HW_INTERFACE_FLAG_LINK_UP);
+  else
+    vnet_hw_interface_set_flags (vnm, hw_if_index, 0 /* down */);
+
+  gre_tunnel_restack (t);
+
+  return /* no error */ 0;
+}
+
+static clib_error_t *
+create_gre_tunnel_command_fn (vlib_main_t *vm, unformat_input_t *input,
+			      vlib_cli_command_t *cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  vnet_gre_tunnel_add_del_args_t _a, *a = &_a;
+  ip46_address_t src = ip46_address_initializer,
+		 dst = ip46_address_initializer;
+  u32 instance = ~0;
+  u32 outer_table_id = 0;
+  gre_tunnel_type_t t_type = GRE_TUNNEL_TYPE_L3;
+  tunnel_mode_t t_mode = TUNNEL_MODE_P2P;
+  tunnel_encap_decap_flags_t flags = TUNNEL_ENCAP_DECAP_FLAG_NONE;
+  u32 session_id = 0;
+  int rv;
+  u8 is_add = 1;
+  u32 sw_if_index;
+  clib_error_t *error = NULL;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "del"))
+	is_add = 0;
+      else if (unformat (line_input, "instance %d", &instance))
+	;
+      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 = TUNNEL_MODE_MP;
+      else if (unformat (line_input, "teb"))
+	t_type = GRE_TUNNEL_TYPE_TEB;
+      else if (unformat (line_input, "erspan %d", &session_id))
+	t_type = GRE_TUNNEL_TYPE_ERSPAN;
+      else if (unformat (line_input, "flags %U",
+			 unformat_tunnel_encap_decap_flags, &flags))
+	;
+      else
+	{
+	  error = clib_error_return (0, "unknown input `%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+  if (ip46_address_is_equal (&src, &dst))
+    {
+      error = clib_error_return (0, "src and dst are identical");
+      goto done;
+    }
+
+  if (t_mode != TUNNEL_MODE_MP && ip46_address_is_zero (&dst))
+    {
+      error = clib_error_return (0, "destination address not specified");
+      goto done;
+    }
+
+  if (ip46_address_is_zero (&src))
+    {
+      error = clib_error_return (0, "source address not specified");
+      goto done;
+    }
+
+  if (ip46_address_is_ip4 (&src) != ip46_address_is_ip4 (&dst))
+    {
+      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_table_id = outer_table_id;
+  a->type = t_type;
+  a->mode = t_mode;
+  a->session_id = session_id;
+  a->is_ipv6 = !ip46_address_is_ip4 (&src);
+  a->instance = instance;
+  a->flags = flags;
+  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);
+
+  switch (rv)
+    {
+    case 0:
+      vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name,
+		       vnet_get_main (), sw_if_index);
+      break;
+    case VNET_API_ERROR_IF_ALREADY_EXISTS:
+      error = clib_error_return (0, "GRE tunnel already exists...");
+      goto done;
+    case VNET_API_ERROR_NO_SUCH_FIB:
+      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");
+      goto done;
+    case VNET_API_ERROR_INVALID_SESSION_ID:
+      error =
+	clib_error_return (0, "session ID %d out of range\n", session_id);
+      goto done;
+    case VNET_API_ERROR_INSTANCE_IN_USE:
+      error = clib_error_return (0, "Instance is in use");
+      goto done;
+    default:
+      error = clib_error_return (0, "vnet_gre_tunnel_add_del returned %d", rv);
+      goto done;
+    }
+
+done:
+  unformat_free (line_input);
+
+  return error;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (create_gre_tunnel_command, static) = {
+  .path = "create gre tunnel",
+  .short_help = "create gre tunnel src <addr> dst <addr> [instance <n>] "
+		"[outer-fib-id <fib>] [teb | erspan <session-id>] [del] "
+		"[multipoint]",
+  .function = create_gre_tunnel_command_fn,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
+show_gre_tunnel_command_fn (vlib_main_t *vm, unformat_input_t *input,
+			    vlib_cli_command_t *cmd)
+{
+  gre_main_t *gm = &gre_main;
+  gre_tunnel_t *t;
+  u32 ti = ~0;
+
+  if (pool_elts (gm->tunnels) == 0)
+    vlib_cli_output (vm, "No GRE tunnels configured...");
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "%d", &ti))
+	;
+      else
+	break;
+    }
+
+  if (~0 == ti)
+    {
+      /* *INDENT-OFF* */
+      pool_foreach (t, gm->tunnels)
+	{
+	  vlib_cli_output (vm, "%U", format_gre_tunnel, t);
+	}
+      /* *INDENT-ON* */
+    }
+  else
+    {
+      t = pool_elt_at_index (gm->tunnels, ti);
+
+      vlib_cli_output (vm, "%U", format_gre_tunnel, t);
+    }
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (show_gre_tunnel_command, static) = {
+  .path = "show gre tunnel",
+  .function = show_gre_tunnel_command_fn,
+};
+/* *INDENT-ON* */
+
+const static teib_vft_t gre_teib_vft = {
+  .nv_added = gre_teib_entry_added,
+  .nv_deleted = gre_teib_entry_deleted,
+};
+
+/* force inclusion from application's main.c */
+clib_error_t *
+gre_interface_init (vlib_main_t *vm)
+{
+  teib_register (&gre_teib_vft);
+
+  return (NULL);
+}
+
+VLIB_INIT_FUNCTION (gre_interface_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */