Reorganize source tree to use single autotools instance

Change-Id: I7b51f88292e057c6443b12224486f2d0c9f8ae23
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 787 insertions, 0 deletions

diff --git a/src/vnet/mpls/mpls_tunnel.c b/src/vnet/mpls/mpls_tunnel.c
new file mode 100644
index 00000000000..8d1e30a36fb
--- /dev/null
+++ b/src/vnet/mpls/mpls_tunnel.c
@@ -0,0 +1,787 @@
+/*
+ * mpls_tunnel.c: MPLS tunnel interfaces (i.e. for RSVP-TE)
+ *
+ * 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 <vnet/pg/pg.h>
+#include <vnet/mpls/mpls_tunnel.h>
+#include <vnet/ip/ip.h>
+#include <vnet/fib/fib_path_list.h>
+#include <vnet/adj/adj_midchain.h>
+
+/**
+ * @brief pool of tunnel instances
+ */
+static mpls_tunnel_t *mpls_tunnel_pool;
+
+/**
+ * @brief Pool of free tunnel SW indices - i.e. recycled indices
+ */
+static u32 * mpls_tunnel_free_hw_if_indices;
+
+/**
+ * @brief DB of SW index to tunnel index
+ */
+static u32 *mpls_tunnel_db;
+
+/**
+ * @brief Get a tunnel object from a SW interface index
+ */
+static mpls_tunnel_t*
+mpls_tunnel_get_from_sw_if_index (u32 sw_if_index)
+{
+    if ((vec_len(mpls_tunnel_db) < sw_if_index) ||
+	(~0 == mpls_tunnel_db[sw_if_index]))
+	return (NULL);
+
+    return (pool_elt_at_index(mpls_tunnel_pool,
+			      mpls_tunnel_db[sw_if_index]));
+}
+
+/**
+ * @brief Return true if the label stack is imp-null only
+ */
+static fib_forward_chain_type_t
+mpls_tunnel_get_fwd_chain_type (const mpls_tunnel_t *mt)
+{
+    if ((1 == vec_len(mt->mt_label_stack)) &&
+	(mt->mt_label_stack[0] == MPLS_IETF_IMPLICIT_NULL_LABEL))
+    {
+	/*
+	 * the only label in the label stack is implicit null
+	 * we need to build an IP chain.
+	 */
+	if (FIB_PROTOCOL_IP4 == fib_path_list_get_proto(mt->mt_path_list))
+	{
+	    return (FIB_FORW_CHAIN_TYPE_UNICAST_IP4);
+	}
+	else
+	{
+	    return (FIB_FORW_CHAIN_TYPE_UNICAST_IP6);
+	}
+    }
+    else
+    {
+	return (FIB_FORW_CHAIN_TYPE_MPLS_NON_EOS);
+    }
+}
+
+/**
+ * @brief Build a rewrite string for the MPLS tunnel.
+ *
+ * We have choices here;
+ *  1 - have an Adjacency with a zero length string and stack it on
+ *       MPLS label objects
+ *  2 - put the label header rewrites in the adjacency string.
+ *
+ * We choose 2 since it results in fewer graph nodes in the egress path
+ */
+static u8*
+mpls_tunnel_build_rewrite (vnet_main_t * vnm,
+			   u32 sw_if_index,
+			   vnet_link_t link_type,
+			   const void *dst_address)
+{
+    mpls_unicast_header_t *muh;
+    mpls_tunnel_t *mt;
+    u8 *rewrite;
+    u32 mti, ii;
+
+    rewrite = NULL;
+    mti = mpls_tunnel_db[sw_if_index];
+    mt = pool_elt_at_index(mpls_tunnel_pool, mti);
+
+    /*
+     * The vector must be allocated as u8 so the length is correct
+     */
+    ASSERT(0 < vec_len(mt->mt_label_stack));
+    vec_validate(rewrite, (sizeof(*muh) * vec_len(mt->mt_label_stack)) - 1);
+    ASSERT(rewrite);
+    muh = (mpls_unicast_header_t *)rewrite;
+
+    /*
+     * The last (inner most) label in the stack may be EOS, all the rest Non-EOS
+     */
+    for (ii = 0; ii < vec_len(mt->mt_label_stack)-1; ii++)
+    {
+	vnet_mpls_uc_set_label(&muh[ii].label_exp_s_ttl, mt->mt_label_stack[ii]);
+	vnet_mpls_uc_set_ttl(&muh[ii].label_exp_s_ttl, 255);
+	vnet_mpls_uc_set_exp(&muh[ii].label_exp_s_ttl, 0);
+	vnet_mpls_uc_set_s(&muh[ii].label_exp_s_ttl, MPLS_NON_EOS);
+	muh[ii].label_exp_s_ttl = clib_host_to_net_u32(muh[ii].label_exp_s_ttl);
+    }
+
+    vnet_mpls_uc_set_label(&muh[ii].label_exp_s_ttl, mt->mt_label_stack[ii]);
+    vnet_mpls_uc_set_ttl(&muh[ii].label_exp_s_ttl, 255);
+    vnet_mpls_uc_set_exp(&muh[ii].label_exp_s_ttl, 0);
+
+    if ((VNET_LINK_MPLS == link_type) &&
+	(mt->mt_label_stack[ii] != MPLS_IETF_IMPLICIT_NULL_LABEL))
+    {
+	vnet_mpls_uc_set_s(&muh[ii].label_exp_s_ttl, MPLS_NON_EOS);
+    }
+    else
+    {
+	vnet_mpls_uc_set_s(&muh[ii].label_exp_s_ttl, MPLS_EOS);
+    }
+
+    muh[ii].label_exp_s_ttl = clib_host_to_net_u32(muh[ii].label_exp_s_ttl);
+
+    return (rewrite);
+}
+
+/**
+ * mpls_tunnel_stack
+ *
+ * 'stack' (resolve the recursion for) the tunnel's midchain adjacency
+ */
+static void
+mpls_tunnel_stack (adj_index_t ai)
+{
+    ip_adjacency_t *adj;
+    mpls_tunnel_t *mt;
+    u32 sw_if_index;
+
+    adj = adj_get(ai);
+    sw_if_index = adj->rewrite_header.sw_if_index;
+
+    mt = mpls_tunnel_get_from_sw_if_index(sw_if_index);
+
+    if (NULL == mt)
+	return;
+
+    /*
+     * find the adjacency that is contributed by the FIB path-list
+     * that this tunnel resovles via, and use it as the next adj
+     * in the midchain
+     */
+    if (vnet_hw_interface_get_flags(vnet_get_main(),
+				    mt->mt_hw_if_index) &
+	VNET_HW_INTERFACE_FLAG_LINK_UP)
+    {
+	dpo_id_t dpo = DPO_INVALID;
+
+	fib_path_list_contribute_forwarding(mt->mt_path_list,
+					    mpls_tunnel_get_fwd_chain_type(mt),
+					    &dpo);
+
+	if (DPO_LOAD_BALANCE == dpo.dpoi_type)
+	{
+	    /*
+	     * we don't support multiple paths, so no need to load-balance.
+	     * pull the first and only choice and stack directly on that.
+	     */
+	    load_balance_t *lb;
+
+	    lb = load_balance_get (dpo.dpoi_index);
+
+	    ASSERT(1 == lb->lb_n_buckets);
+
+	    dpo_copy(&dpo, load_balance_get_bucket_i (lb, 0));
+	}
+
+	adj_nbr_midchain_stack(ai, &dpo);
+	dpo_reset(&dpo);
+    }
+    else
+    {
+	adj_nbr_midchain_unstack(ai);
+    }
+}
+
+/**
+ * @brief Call back when restacking all adjacencies on a MPLS interface
+ */
+static adj_walk_rc_t
+mpls_adj_walk_cb (adj_index_t ai,
+		 void *ctx)
+{
+    mpls_tunnel_stack(ai);
+
+    return (ADJ_WALK_RC_CONTINUE);
+}
+
+static void
+mpls_tunnel_restack (mpls_tunnel_t *mt)
+{
+    fib_protocol_t proto;
+
+    /*
+     * walk all the adjacencies on the MPLS interface and restack them
+     */
+    FOR_EACH_FIB_PROTOCOL(proto)
+    {
+	adj_nbr_walk(mt->mt_sw_if_index,
+		     proto,
+		     mpls_adj_walk_cb,
+		     NULL);
+    }
+}
+
+static clib_error_t *
+mpls_tunnel_admin_up_down (vnet_main_t * vnm,
+			   u32 hw_if_index,
+			   u32 flags)
+{
+    vnet_hw_interface_t * hi;
+    mpls_tunnel_t *mt;
+
+    hi = vnet_get_hw_interface (vnm, hw_if_index);
+
+    mt = mpls_tunnel_get_from_sw_if_index(hi->sw_if_index);
+
+    if (NULL == mt)
+	return (NULL);
+
+    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 */);
+
+    mpls_tunnel_restack(mt);
+
+    return (NULL);
+}
+
+/**
+ * @brief Fixup the adj rewrite post encap. This is a no-op since the
+ * rewrite is a stack of labels.
+ */
+static void
+mpls_tunnel_fixup (vlib_main_t *vm,
+		   ip_adjacency_t *adj,
+		   vlib_buffer_t *b0)
+{
+}
+
+static void
+mpls_tunnel_update_adj (vnet_main_t * vnm,
+			u32 sw_if_index,
+			adj_index_t ai)
+{
+    adj_nbr_midchain_update_rewrite(
+	ai, mpls_tunnel_fixup, 
+	ADJ_MIDCHAIN_FLAG_NONE,
+	mpls_tunnel_build_rewrite(vnm, sw_if_index,
+				  adj_get_link_type(ai),
+				  NULL));
+
+    mpls_tunnel_stack(ai);
+}
+
+static u8 *
+format_mpls_tunnel_name (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  return format (s, "mpls-tunnel%d", dev_instance);
+}
+
+static u8 *
+format_mpls_tunnel_device (u8 * s, va_list * args)
+{
+  u32 dev_instance = va_arg (*args, u32);
+  CLIB_UNUSED (int verbose) = va_arg (*args, int);
+
+  return (format (s, "MPLS-tunnel: id %d\n", dev_instance));
+}
+
+/**
+ * @brief Packet trace structure
+ */
+typedef struct mpls_tunnel_trace_t_
+{
+    /**
+   * Tunnel-id / index in tunnel vector
+   */
+  u32 tunnel_id;
+} mpls_tunnel_trace_t;
+
+static u8 *
+format_mpls_tunnel_tx_trace (u8 * s,
+			     va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  mpls_tunnel_trace_t * t = va_arg (*args, mpls_tunnel_trace_t *);
+
+  s = format (s, "MPLS: tunnel %d", t->tunnel_id);
+  return s;
+}
+
+/**
+ * @brief TX function. Only called L2. L3 traffic uses the adj-midchains
+ */
+static uword
+mpls_tunnel_tx (vlib_main_t * vm,
+		vlib_node_runtime_t * node,
+		vlib_frame_t * frame)
+{
+  u32 next_index;
+  u32 * from, * to_next, n_left_from, n_left_to_next;
+  vnet_interface_output_runtime_t * rd = (void *) node->runtime_data;
+  const mpls_tunnel_t *mt;
+
+  mt = pool_elt_at_index(mpls_tunnel_pool, rd->dev_instance);
+
+  /* Vector of buffer / pkt indices we're supposed to process */
+  from = vlib_frame_vector_args (frame);
+
+  /* Number of buffers / pkts */
+  n_left_from = frame->n_vectors;
+
+  /* Speculatively send the first buffer to the last disposition we used */
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      /* set up to enqueue to our disposition with index = next_index */
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      /*
+       * FIXME DUAL LOOP
+       */
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  vlib_buffer_t * b0;
+	  u32 bi0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer(vm, bi0);
+
+	  vnet_buffer(b0)->ip.adj_index[VLIB_TX] = mt->mt_l2_adj;
+
+	  if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      mpls_tunnel_trace_t *tr = vlib_add_trace (vm, node,
+						   b0, sizeof (*tr));
+	      tr->tunnel_id = rd->dev_instance;
+	    }
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, mt->mt_l2_tx_arc);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+VNET_DEVICE_CLASS (mpls_tunnel_class) = {
+    .name = "MPLS tunnel device",
+    .format_device_name = format_mpls_tunnel_name,
+    .format_device = format_mpls_tunnel_device,
+    .format_tx_trace = format_mpls_tunnel_tx_trace,
+    .tx_function = mpls_tunnel_tx,
+    .admin_up_down_function = mpls_tunnel_admin_up_down,
+};
+
+VNET_HW_INTERFACE_CLASS (mpls_tunnel_hw_interface_class) = {
+  .name = "MPLS-Tunnel",
+//  .format_header = format_mpls_eth_header_with_length,
+//  .unformat_header = unformat_mpls_eth_header,
+  .update_adjacency = mpls_tunnel_update_adj,
+  .build_rewrite = mpls_tunnel_build_rewrite,
+  .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
+};
+
+const mpls_tunnel_t *
+mpls_tunnel_get (u32 mti)
+{
+    return (pool_elt_at_index(mpls_tunnel_pool, mti));
+}
+
+/**
+ * @brief Walk all the MPLS tunnels
+ */
+void
+mpls_tunnel_walk (mpls_tunnel_walk_cb_t cb,
+		  void *ctx)
+{
+    u32 mti;
+
+    pool_foreach_index(mti, mpls_tunnel_pool,
+    ({
+	cb(mti, ctx);
+    }));
+}
+
+void
+vnet_mpls_tunnel_del (u32 sw_if_index)
+{
+    mpls_tunnel_t *mt;
+
+    mt = mpls_tunnel_get_from_sw_if_index(sw_if_index);
+
+    if (NULL == mt)
+	return;
+    
+    fib_path_list_child_remove(mt->mt_path_list,
+			       mt->mt_sibling_index);
+    if (ADJ_INDEX_INVALID != mt->mt_l2_adj)
+	adj_unlock(mt->mt_l2_adj);
+
+    vec_free(mt->mt_label_stack);
+
+    vec_add1 (mpls_tunnel_free_hw_if_indices, mt->mt_hw_if_index);
+    pool_put(mpls_tunnel_pool, mt);
+    mpls_tunnel_db[sw_if_index] = ~0;
+}
+
+void
+vnet_mpls_tunnel_add (fib_route_path_t *rpaths,
+		      mpls_label_t *label_stack,
+		      u8 l2_only,
+		      u32 *sw_if_index)
+{
+    vnet_hw_interface_t * hi;
+    mpls_tunnel_t *mt;
+    vnet_main_t * vnm;
+    u32 mti;
+
+    vnm = vnet_get_main();
+    pool_get(mpls_tunnel_pool, mt);
+    memset (mt, 0, sizeof (*mt));
+    mti = mt - mpls_tunnel_pool;
+    fib_node_init(&mt->mt_node, FIB_NODE_TYPE_MPLS_TUNNEL);
+    mt->mt_l2_adj = ADJ_INDEX_INVALID;
+
+    /*
+     * Create a new, or re=use and old, tunnel HW interface
+     */
+    if (vec_len (mpls_tunnel_free_hw_if_indices) > 0)
+    {
+	mt->mt_hw_if_index = 
+	    mpls_tunnel_free_hw_if_indices[vec_len(mpls_tunnel_free_hw_if_indices)-1];
+	_vec_len (mpls_tunnel_free_hw_if_indices) -= 1;
+	hi = vnet_get_hw_interface (vnm, mt->mt_hw_if_index);
+	hi->hw_instance = mti;
+	hi->dev_instance = mti;
+    }
+    else 
+    {
+	mt->mt_hw_if_index = vnet_register_interface(
+	                         vnm,
+				 mpls_tunnel_class.index,
+				 mti,
+				 mpls_tunnel_hw_interface_class.index,
+				 mti);
+	hi = vnet_get_hw_interface(vnm, mt->mt_hw_if_index);
+    }
+
+    /*
+     * Add the new tunnel to the tunnel DB - key:SW if index
+     */
+    mt->mt_sw_if_index = hi->sw_if_index;
+    vec_validate_init_empty(mpls_tunnel_db, mt->mt_sw_if_index, ~0);
+    mpls_tunnel_db[mt->mt_sw_if_index] = mti;
+
+    /*
+     * construct a path-list from the path provided
+     */
+    mt->mt_path_list = fib_path_list_create(FIB_PATH_LIST_FLAG_SHARED, rpaths);
+    mt->mt_sibling_index = fib_path_list_child_add(mt->mt_path_list,
+						   FIB_NODE_TYPE_MPLS_TUNNEL,
+						   mti);
+
+    mt->mt_label_stack = vec_dup(label_stack);
+
+    if (l2_only)
+    {
+	mt->mt_l2_adj =
+	    adj_nbr_add_or_lock(fib_path_list_get_proto(mt->mt_path_list),
+				VNET_LINK_ETHERNET,
+				&zero_addr,
+				mt->mt_sw_if_index);
+
+	mt->mt_l2_tx_arc = vlib_node_add_named_next(vlib_get_main(),
+						    hi->tx_node_index,
+						    "adj-l2-midchain");
+    }
+
+    *sw_if_index = mt->mt_sw_if_index;
+}
+
+static clib_error_t *
+vnet_create_mpls_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_main_t * vnm = vnet_get_main();
+    u8 is_del = 0;
+    u8 l2_only = 0;
+    fib_route_path_t rpath, *rpaths = NULL;
+    mpls_label_t out_label = MPLS_LABEL_INVALID, *labels = NULL;
+    u32 sw_if_index;
+
+    memset(&rpath, 0, sizeof(rpath));
+
+    /* 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 %U",
+		      unformat_vnet_sw_interface, vnm,
+		      &sw_if_index))
+	    is_del = 1;
+	else if (unformat (line_input, "add"))
+	    is_del = 0;
+	else if (unformat (line_input, "out-label %U",
+			   unformat_mpls_unicast_label, &out_label))
+	{
+	    vec_add1(labels, out_label);
+	}
+	else if (unformat (line_input, "via %U %U",
+			   unformat_ip4_address,
+			   &rpath.frp_addr.ip4,
+			   unformat_vnet_sw_interface, vnm,
+			   &rpath.frp_sw_if_index))
+	{
+	    rpath.frp_weight = 1;
+	    rpath.frp_proto = FIB_PROTOCOL_IP4;
+	}
+			 
+	else if (unformat (line_input, "via %U %U",
+			   unformat_ip6_address,
+			   &rpath.frp_addr.ip6,
+			   unformat_vnet_sw_interface, vnm,
+			   &rpath.frp_sw_if_index))
+	{
+	    rpath.frp_weight = 1;
+	    rpath.frp_proto = FIB_PROTOCOL_IP6;
+	}
+	else if (unformat (line_input, "via %U",
+			   unformat_ip6_address,
+			   &rpath.frp_addr.ip6))
+	{
+	    rpath.frp_fib_index = 0;
+	    rpath.frp_weight = 1;
+	    rpath.frp_sw_if_index = ~0;
+	    rpath.frp_proto = FIB_PROTOCOL_IP6;
+	}
+	else if (unformat (line_input, "via %U",
+			   unformat_ip4_address,
+			   &rpath.frp_addr.ip4))
+	{
+	    rpath.frp_fib_index = 0;
+	    rpath.frp_weight = 1;
+	    rpath.frp_sw_if_index = ~0;
+	    rpath.frp_proto = FIB_PROTOCOL_IP4;
+	}
+	else if (unformat (line_input, "l2-only"))
+	    l2_only = 1;
+	else
+	    return clib_error_return (0, "unknown input '%U'",
+				      format_unformat_error, line_input);
+    }
+
+    if (is_del)
+    {
+	vnet_mpls_tunnel_del(sw_if_index);
+    }
+    else
+    {
+	if (0 == vec_len(labels))
+	    return clib_error_return (0, "No Output Labels '%U'",
+				      format_unformat_error, line_input);
+
+	vec_add1(rpaths, rpath);
+	vnet_mpls_tunnel_add(rpaths, labels, l2_only, &sw_if_index);
+    }
+
+    vec_free(labels);
+    vec_free(rpaths);
+
+    return (NULL);
+}
+
+/*?
+ * This command create a uni-directional MPLS tunnel
+ *
+ * @cliexpar
+ * @cliexstart{create mpls tunnel}
+ *  create mpls tunnel via 10.0.0.1 GigEthernet0/8/0 out-label 33 out-label 34
+ * @cliexend
+ ?*/
+VLIB_CLI_COMMAND (create_mpls_tunnel_command, static) = {
+  .path = "mpls tunnel",
+  .short_help = 
+  "mpls tunnel via [addr] [interface] [out-labels]",
+  .function = vnet_create_mpls_tunnel_command_fn,
+};
+
+static u8 *
+format_mpls_tunnel (u8 * s, va_list * args)
+{
+    mpls_tunnel_t *mt = va_arg (*args, mpls_tunnel_t *);
+    int ii;
+
+    s = format(s, "mpls_tunnel%d: sw_if_index:%d hw_if_index:%d",
+	       mt - mpls_tunnel_pool,
+	       mt->mt_sw_if_index,
+	       mt->mt_hw_if_index);
+    s = format(s, "\n label-stack:\n  ");
+    for (ii = 0; ii < vec_len(mt->mt_label_stack); ii++)
+    {
+	s = format(s, "%d, ", mt->mt_label_stack[ii]);
+    }
+    s = format(s, "\n via:\n");
+    s = fib_path_list_format(mt->mt_path_list, s);
+    s = format(s, "\n");
+
+    return (s);
+}
+
+static clib_error_t *
+show_mpls_tunnel_command_fn (vlib_main_t * vm,
+			     unformat_input_t * input,
+			     vlib_cli_command_t * cmd)
+{
+    mpls_tunnel_t * mt;
+    u32 mti = ~0;
+
+    if (pool_elts (mpls_tunnel_pool) == 0)
+	vlib_cli_output (vm, "No MPLS tunnels configured...");
+
+    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+	if (unformat (input, "%d", &mti))
+	    ;
+	else
+	    break;
+    }
+
+    if (~0 == mti)
+    {
+	pool_foreach (mt, mpls_tunnel_pool,
+	({
+	    vlib_cli_output (vm, "[@%d] %U",
+			     mt - mpls_tunnel_pool,
+			     format_mpls_tunnel, mt);
+	}));
+    }
+    else
+    {
+	if (pool_is_free_index(mpls_tunnel_pool, mti))
+	    return clib_error_return (0, "Not atunnel index %d", mti);
+
+	mt = pool_elt_at_index(mpls_tunnel_pool, mti);
+
+	vlib_cli_output (vm, "[@%d] %U",
+			 mt - mpls_tunnel_pool,
+			 format_mpls_tunnel, mt);
+    }
+
+    return 0;
+}
+
+/*?
+ * This command to show MPLS tunnels
+ *
+ * @cliexpar
+ * @cliexstart{sh mpls tunnel 2}
+ * [@2] mpls_tunnel2: sw_if_index:5 hw_if_index:5
+ *  label-stack:
+ *    3, 
+ *  via:
+ *   index:26 locks:1 proto:ipv4 uPRF-list:26 len:1 itfs:[2, ]
+ *     index:26 pl-index:26 ipv4 weight=1 attached-nexthop:  oper-flags:resolved,
+ *      10.0.0.2 loop0
+ *         [@0]: ipv4 via 10.0.0.2 loop0: IP4: de:ad:00:00:00:00 -> 00:00:11:aa:bb:cc
+ * @cliexend
+ ?*/
+VLIB_CLI_COMMAND (show_mpls_tunnel_command, static) = {
+    .path = "show mpls tunnel",
+    .function = show_mpls_tunnel_command_fn,
+};
+
+static mpls_tunnel_t *
+mpls_tunnel_from_fib_node (fib_node_t *node)
+{
+#if (CLIB_DEBUG > 0)
+    ASSERT(FIB_NODE_TYPE_MPLS_TUNNEL == node->fn_type);
+#endif
+    return ((mpls_tunnel_t*) (((char*)node) -
+                             STRUCT_OFFSET_OF(mpls_tunnel_t, mt_node)));
+}
+
+/**
+ * Function definition to backwalk a FIB node
+ */
+static fib_node_back_walk_rc_t
+mpls_tunnel_back_walk (fib_node_t *node,
+		      fib_node_back_walk_ctx_t *ctx)
+{
+    mpls_tunnel_restack(mpls_tunnel_from_fib_node(node));
+
+    return (FIB_NODE_BACK_WALK_CONTINUE);
+}
+
+/**
+ * Function definition to get a FIB node from its index
+ */
+static fib_node_t*
+mpls_tunnel_fib_node_get (fib_node_index_t index)
+{
+    mpls_tunnel_t * mt;
+
+    mt = pool_elt_at_index(mpls_tunnel_pool, index);
+
+    return (&mt->mt_node);
+}
+
+/**
+ * Function definition to inform the FIB node that its last lock has gone.
+ */
+static void
+mpls_tunnel_last_lock_gone (fib_node_t *node)
+{
+    /*
+     * The MPLS MPLS tunnel is a root of the graph. As such
+     * it never has children and thus is never locked.
+     */
+    ASSERT(0);
+}
+
+/*
+ * Virtual function table registered by MPLS MPLS tunnels
+ * for participation in the FIB object graph.
+ */
+const static fib_node_vft_t mpls_vft = {
+    .fnv_get = mpls_tunnel_fib_node_get,
+    .fnv_last_lock = mpls_tunnel_last_lock_gone,
+    .fnv_back_walk = mpls_tunnel_back_walk,
+};
+
+static clib_error_t *
+mpls_tunnel_init (vlib_main_t *vm)
+{
+  fib_node_register_type(FIB_NODE_TYPE_MPLS_TUNNEL, &mpls_vft);
+
+  return 0;
+}
+VLIB_INIT_FUNCTION(mpls_tunnel_init);