vnet/vnet/vxlan-gpe/vxlan_gpe.c - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2015 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/vxlan-gpe/vxlan_gpe.h>
 #include <vnet/ip/format.h>

 vxlan_gpe_main_t vxlan_gpe_main;

 u8 * format_vxlan_gpe_tunnel (u8 * s, va_list * args)
 {
   vxlan_gpe_tunnel_t * t = va_arg (*args, vxlan_gpe_tunnel_t *);
   vxlan_gpe_main_t * gm = &vxlan_gpe_main;

   s = format (s, "[%d] local: %U remote: %U ",
               t - gm->tunnels,
               format_ip46_address, &t->local, IP46_TYPE_ANY,
               format_ip46_address, &t->remote, IP46_TYPE_ANY);

   s = format (s, "  vxlan VNI %d ", t->vni);

   switch (t->protocol)
     {
     case VXLAN_GPE_PROTOCOL_IP4:
       s = format (s, "next-protocol ip4");
       break;
     case VXLAN_GPE_PROTOCOL_IP6:
       s = format (s, "next-protocol ip6");
       break;
     case VXLAN_GPE_PROTOCOL_ETHERNET:
       s = format (s, "next-protocol ethernet");
       break;
     case VXLAN_GPE_PROTOCOL_NSH:
       s = format (s, "next-protocol nsh");
       break;
     default:
       s = format (s, "next-protocol unknown %d", t->protocol);
     }

   s = format (s, " fibs: (encap %d, decap %d)",
               t->encap_fib_index,
               t->decap_fib_index);

   return s;
 }

 static u8 * format_vxlan_gpe_name (u8 * s, va_list * args)
 {
   u32 dev_instance = va_arg (*args, u32);
   return format (s, "vxlan_gpe_tunnel%d", dev_instance);
 }


 static uword dummy_interface_tx (vlib_main_t * vm,
                                  vlib_node_runtime_t * node,
                                  vlib_frame_t * frame)
 {
   clib_warning ("you shouldn't be here, leaking buffers...");
   return frame->n_vectors;
 }
 static clib_error_t *
 vxlan_gpe_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
 {
   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);

   return 0;
 }

 VNET_DEVICE_CLASS (vxlan_gpe_device_class,static) = {
   .name = "VXLAN_GPE",
   .format_device_name = format_vxlan_gpe_name,
   .format_tx_trace = format_vxlan_gpe_encap_trace,
   .tx_function = dummy_interface_tx,
   .admin_up_down_function = vxlan_gpe_interface_admin_up_down,
 };

 static uword dummy_set_rewrite (vnet_main_t * vnm,
                                 u32 sw_if_index,
                                 u32 l3_type,
                                 void * dst_address,
                                 void * rewrite,
                                 uword max_rewrite_bytes)
 {
   return 0;
 }


 static u8 * format_vxlan_gpe_header_with_length (u8 * s, va_list * args)
 {
   u32 dev_instance = va_arg (*args, u32);
   s = format (s, "unimplemented dev %u", dev_instance);
   return s;
 }

 VNET_HW_INTERFACE_CLASS (vxlan_gpe_hw_class) = {
   .name = "VXLAN_GPE",
   .format_header = format_vxlan_gpe_header_with_length,
   .set_rewrite = dummy_set_rewrite,
 };


 #define foreach_gpe_copy_field                  \
 _(vni)                                          \
 _(protocol)                                \
 _(encap_fib_index)                              \
 _(decap_fib_index)

 #define foreach_copy_ipv4 {                     \
   _(local.ip4.as_u32)                           \
   _(remote.ip4.as_u32)                          \
 }

 #define foreach_copy_ipv6 {                     \
   _(local.ip6.as_u64[0])                        \
   _(local.ip6.as_u64[1])                        \
   _(remote.ip6.as_u64[0])                       \
   _(remote.ip6.as_u64[1])                       \
 }


 static int vxlan4_gpe_rewrite (vxlan_gpe_tunnel_t * t)
 {
   u8 *rw = 0;
   ip4_header_t * ip0;
   ip4_vxlan_gpe_header_t * h0;
   int len;

   len = sizeof (*h0);

   vec_validate_aligned (rw, len-1, CLIB_CACHE_LINE_BYTES);

   h0 = (ip4_vxlan_gpe_header_t *) rw;

   /* Fixed portion of the (outer) ip4 header */
   ip0 = &h0->ip4;
   ip0->ip_version_and_header_length = 0x45;
   ip0->ttl = 254;
   ip0->protocol = IP_PROTOCOL_UDP;

   /* we fix up the ip4 header length and checksum after-the-fact */
   ip0->src_address.as_u32 = t->local.ip4.as_u32;
   ip0->dst_address.as_u32 = t->remote.ip4.as_u32;
   ip0->checksum = ip4_header_checksum (ip0);

   /* UDP header, randomize src port on something, maybe? */
   h0->udp.src_port = clib_host_to_net_u16 (4790);
   h0->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_vxlan_gpe);

   /* VXLAN header. Are we having fun yet? */
   h0->vxlan.flags = VXLAN_GPE_FLAGS_I | VXLAN_GPE_FLAGS_P;
   h0->vxlan.ver_res = VXLAN_GPE_VERSION;
   h0->vxlan.protocol = t->protocol;
   h0->vxlan.vni_res = clib_host_to_net_u32 (t->vni<<8);

   t->rewrite = rw;
   return (0);
 }

 static int vxlan6_gpe_rewrite (vxlan_gpe_tunnel_t * t)
 {
   u8 *rw = 0;
   ip6_header_t * ip0;
   ip6_vxlan_gpe_header_t * h0;
   int len;

   len = sizeof (*h0);

   vec_validate_aligned (rw, len-1, CLIB_CACHE_LINE_BYTES);

   h0 = (ip6_vxlan_gpe_header_t *) rw;

   /* Fixed portion of the (outer) ip4 header */
   ip0 = &h0->ip6;
   ip0->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32(6 << 28);
   ip0->hop_limit = 255;
   ip0->protocol = IP_PROTOCOL_UDP;

   ip0->src_address.as_u64[0] = t->local.ip6.as_u64[0];
   ip0->src_address.as_u64[1] = t->local.ip6.as_u64[1];
   ip0->dst_address.as_u64[0] = t->remote.ip6.as_u64[0];
   ip0->dst_address.as_u64[1] = t->remote.ip6.as_u64[1];

   /* UDP header, randomize src port on something, maybe? */
   h0->udp.src_port = clib_host_to_net_u16 (4790);
   h0->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_vxlan_gpe);

   /* VXLAN header. Are we having fun yet? */
   h0->vxlan.flags = VXLAN_GPE_FLAGS_I | VXLAN_GPE_FLAGS_P;
   h0->vxlan.ver_res = VXLAN_GPE_VERSION;
   h0->vxlan.protocol = t->protocol;
   h0->vxlan.vni_res = clib_host_to_net_u32 (t->vni<<8);

   t->rewrite = rw;
   return (0);
 }

 int vnet_vxlan_gpe_add_del_tunnel
 (vnet_vxlan_gpe_add_del_tunnel_args_t *a, u32 * sw_if_indexp)
 {
   vxlan_gpe_main_t * gm = &vxlan_gpe_main;
   vxlan_gpe_tunnel_t *t = 0;
   vnet_main_t * vnm = gm->vnet_main;
   vnet_hw_interface_t * hi;
   uword * p;
   u32 hw_if_index = ~0;
   u32 sw_if_index = ~0;
   int rv;
   vxlan4_gpe_tunnel_key_t key4, *key4_copy;
   vxlan6_gpe_tunnel_key_t key6, *key6_copy;
   hash_pair_t *hp;

   if (!a->is_ip6)
   {
     key4.local = a->local.ip4.as_u32;
     key4.remote = a->remote.ip4.as_u32;
     key4.vni = clib_host_to_net_u32 (a->vni << 8);
     key4.pad = 0;

     p = hash_get_mem(gm->vxlan4_gpe_tunnel_by_key, &key4);
   }
   else
   {
     key6.local.as_u64[0] = a->local.ip6.as_u64[0];
     key6.local.as_u64[1] = a->local.ip6.as_u64[1];
     key6.remote.as_u64[0] = a->remote.ip6.as_u64[0];
     key6.remote.as_u64[1] = a->remote.ip6.as_u64[1];
     key6.vni = clib_host_to_net_u32 (a->vni << 8);

     p = hash_get_mem(gm->vxlan6_gpe_tunnel_by_key, &key6);
   }

   if (a->is_add)
     {
       /* adding a tunnel: tunnel must not already exist */
       if (p)
         return VNET_API_ERROR_INVALID_VALUE;

       pool_get_aligned (gm->tunnels, t, CLIB_CACHE_LINE_BYTES);
       memset (t, 0, sizeof (*t));

       /* copy from arg structure */
 #define _(x) t->x = a->x;
       foreach_gpe_copy_field;
       if (!a->is_ip6) foreach_copy_ipv4
       else            foreach_copy_ipv6
 #undef _

       if (!a->is_ip6) t->flags |= VXLAN_GPE_TUNNEL_IS_IPV4;

       if (!a->is_ip6) {
         rv = vxlan4_gpe_rewrite (t);
       } else {
         rv = vxlan6_gpe_rewrite (t);
       }

       if (rv)
       {
           pool_put (gm->tunnels, t);
           return rv;
       }

       if (!a->is_ip6)
       {
         key4_copy = clib_mem_alloc (sizeof (*key4_copy));
         clib_memcpy (key4_copy, &key4, sizeof (*key4_copy));
         hash_set_mem (gm->vxlan4_gpe_tunnel_by_key, key4_copy,
                       t - gm->tunnels);
       }
       else
       {
           key6_copy = clib_mem_alloc (sizeof (*key6_copy));
           clib_memcpy (key6_copy, &key6, sizeof (*key6_copy));
           hash_set_mem (gm->vxlan6_gpe_tunnel_by_key, key6_copy,
                         t - gm->tunnels);
       }

       if (vec_len (gm->free_vxlan_gpe_tunnel_hw_if_indices) > 0)
         {
           hw_if_index = gm->free_vxlan_gpe_tunnel_hw_if_indices
             [vec_len (gm->free_vxlan_gpe_tunnel_hw_if_indices)-1];
           _vec_len (gm->free_vxlan_gpe_tunnel_hw_if_indices) -= 1;

           hi = vnet_get_hw_interface (vnm, hw_if_index);
           hi->dev_instance = t - gm->tunnels;
           hi->hw_instance = hi->dev_instance;
         }
       else
         {
           hw_if_index = vnet_register_interface
             (vnm, vxlan_gpe_device_class.index, t - gm->tunnels,
              vxlan_gpe_hw_class.index, t - gm->tunnels);
           hi = vnet_get_hw_interface (vnm, hw_if_index);
           hi->output_node_index = vxlan_gpe_encap_node.index;
         }

       t->hw_if_index = hw_if_index;
       t->sw_if_index = sw_if_index = hi->sw_if_index;
       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 - gm->tunnels;

       vnet_sw_interface_set_flags (vnm, hi->sw_if_index,
                                    VNET_SW_INTERFACE_FLAG_ADMIN_UP);
     }
   else
     {
       /* deleting a tunnel: tunnel must exist */
       if (!p)
         return VNET_API_ERROR_NO_SUCH_ENTRY;

       t = pool_elt_at_index (gm->tunnels, p[0]);

       vnet_sw_interface_set_flags (vnm, t->sw_if_index, 0 /* down */);
       vec_add1 (gm->free_vxlan_gpe_tunnel_hw_if_indices, t->hw_if_index);

       gm->tunnel_index_by_sw_if_index[t->sw_if_index] = ~0;

       if (!a->is_ip6)
       {
         hp = hash_get_pair (gm->vxlan4_gpe_tunnel_by_key, &key4);
         key4_copy = (void *)(hp->key);
         hash_unset_mem (gm->vxlan4_gpe_tunnel_by_key, &key4);
         clib_mem_free (key4_copy);
       }
       else
       {
         hp = hash_get_pair (gm->vxlan6_gpe_tunnel_by_key, &key6);
         key6_copy = (void *)(hp->key);
         hash_unset_mem (gm->vxlan4_gpe_tunnel_by_key, &key6);
         clib_mem_free (key6_copy);
       }

       vec_free (t->rewrite);
       pool_put (gm->tunnels, t);
     }

   if (sw_if_indexp)
       *sw_if_indexp = sw_if_index;

   return 0;
 }

 static u32 fib4_index_from_fib_id (u32 fib_id)
 {
   ip4_main_t * im = &ip4_main;
   uword * p;

   p = hash_get (im->fib_index_by_table_id, fib_id);
   if (!p)
     return ~0;

   return p[0];
 }

 static u32 fib6_index_from_fib_id (u32 fib_id)
 {
   ip6_main_t * im = &ip6_main;
   uword * p;

   p = hash_get (im->fib_index_by_table_id, fib_id);
   if (!p)
     return ~0;

   return p[0];
 }

 static clib_error_t *
 vxlan_gpe_add_del_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;
   u8 is_add = 1;
   ip46_address_t local, remote;
   u8 local_set = 0;
   u8 remote_set = 0;
   u8 ipv4_set = 0;
   u8 ipv6_set = 0;
   u32 encap_fib_index = 0;
   u32 decap_fib_index = 0;
   u8 protocol = VXLAN_GPE_PROTOCOL_IP4;
   u32 vni;
   u8 vni_set = 0;
   int rv;
   u32 tmp;
   vnet_vxlan_gpe_add_del_tunnel_args_t _a, * a = &_a;
   u32 sw_if_index;

   /* 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, "local %U",
                        unformat_ip4_address, &local.ip4))
     {
       local_set = 1;
       ipv4_set = 1;
     }
     else if (unformat (line_input, "remote %U",
                        unformat_ip4_address, &remote.ip4))
     {
       remote_set = 1;
       ipv4_set = 1;
     }
     else if (unformat (line_input, "local %U",
                        unformat_ip6_address, &local.ip6))
     {
       local_set = 1;
       ipv6_set = 1;
     }
     else if (unformat (line_input, "remote %U",
                        unformat_ip6_address, &remote.ip6))
     {
       remote_set = 1;
       ipv6_set = 1;
     }
     else if (unformat (line_input, "encap-vrf-id %d", &tmp))
       {
         if (ipv6_set)
           encap_fib_index = fib6_index_from_fib_id (tmp);
         else
           encap_fib_index = fib4_index_from_fib_id (tmp);

         if (encap_fib_index == ~0)
           return clib_error_return (0, "nonexistent encap fib id %d", tmp);
       }
     else if (unformat (line_input, "decap-vrf-id %d", &tmp))
       {

         if (ipv6_set)
           decap_fib_index = fib6_index_from_fib_id (tmp);
         else
           decap_fib_index = fib4_index_from_fib_id (tmp);

         if (decap_fib_index == ~0)
           return clib_error_return (0, "nonexistent decap fib id %d", tmp);
       }
     else if (unformat (line_input, "vni %d", &vni))
       vni_set = 1;
     else if (unformat(line_input, "next-ip4"))
       protocol = VXLAN_GPE_PROTOCOL_IP4;
     else if (unformat(line_input, "next-ip6"))
       protocol = VXLAN_GPE_PROTOCOL_IP6;
     else if (unformat(line_input, "next-ethernet"))
       protocol = VXLAN_GPE_PROTOCOL_ETHERNET;
     else if (unformat(line_input, "next-nsh"))
       protocol = VXLAN_GPE_PROTOCOL_NSH;
     else
       return clib_error_return (0, "parse error: '%U'",
                                 format_unformat_error, line_input);
   }

   unformat_free (line_input);

   if (local_set == 0)
     return clib_error_return (0, "tunnel local address not specified");

   if (remote_set == 0)
     return clib_error_return (0, "tunnel remote address not specified");

   if (ipv4_set && ipv6_set)
     return clib_error_return (0, "both IPv4 and IPv6 addresses specified");

   if ((ipv4_set && memcmp(&local.ip4, &remote.ip4, sizeof(local.ip4)) == 0) ||
       (ipv6_set && memcmp(&local.ip6, &remote.ip6, sizeof(local.ip6)) == 0))
     return clib_error_return (0, "src and dst addresses are identical");

   if (vni_set == 0)
     return clib_error_return (0, "vni not specified");

   memset (a, 0, sizeof (*a));

   a->is_add = is_add;
   a->is_ip6 = ipv6_set;

 #define _(x) a->x = x;
   foreach_gpe_copy_field;
   if (ipv4_set) foreach_copy_ipv4
   else          foreach_copy_ipv6
 #undef _

   rv = vnet_vxlan_gpe_add_del_tunnel (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_INVALID_DECAP_NEXT:
       return clib_error_return (0, "invalid decap-next...");

     case VNET_API_ERROR_TUNNEL_EXIST:
       return clib_error_return (0, "tunnel already exists...");

     case VNET_API_ERROR_NO_SUCH_ENTRY:
       return clib_error_return (0, "tunnel does not exist...");

     default:
       return clib_error_return
         (0, "vnet_vxlan_gpe_add_del_tunnel returned %d", rv);
     }

   return 0;
 }

 VLIB_CLI_COMMAND (create_vxlan_gpe_tunnel_command, static) = {
   .path = "create vxlan-gpe tunnel",
   .short_help =
   "create vxlan-gpe tunnel local <local-addr> remote <remote-addr>"
   " vni <nn> [next-ip4][next-ip6][next-ethernet][next-nsh]"
   " [encap-vrf-id <nn>] [decap-vrf-id <nn>]"
   " [del]\n",
   .function = vxlan_gpe_add_del_tunnel_command_fn,
 };

 static clib_error_t *
 show_vxlan_gpe_tunnel_command_fn (vlib_main_t * vm,
                                 unformat_input_t * input,
                                 vlib_cli_command_t * cmd)
 {
   vxlan_gpe_main_t * gm = &vxlan_gpe_main;
   vxlan_gpe_tunnel_t * t;

   if (pool_elts (gm->tunnels) == 0)
     vlib_cli_output (vm, "No vxlan-gpe tunnels configured.");

   pool_foreach (t, gm->tunnels,
   ({
     vlib_cli_output (vm, "%U", format_vxlan_gpe_tunnel, t);
   }));

   return 0;
 }

 VLIB_CLI_COMMAND (show_vxlan_gpe_tunnel_command, static) = {
     .path = "show vxlan-gpe",
     .function = show_vxlan_gpe_tunnel_command_fn,
 };

 clib_error_t *vxlan_gpe_init (vlib_main_t *vm)
 {
   vxlan_gpe_main_t *gm = &vxlan_gpe_main;

   gm->vnet_main = vnet_get_main();
   gm->vlib_main = vm;

   gm->vxlan4_gpe_tunnel_by_key
     = hash_create_mem (0, sizeof(vxlan4_gpe_tunnel_key_t), sizeof (uword));

   gm->vxlan6_gpe_tunnel_by_key
     = hash_create_mem (0, sizeof(vxlan6_gpe_tunnel_key_t), sizeof (uword));


   udp_register_dst_port (vm, UDP_DST_PORT_vxlan_gpe,
                          vxlan4_gpe_input_node.index, 1 /* is_ip4 */);
   udp_register_dst_port (vm, UDP_DST_PORT_vxlan6_gpe,
                          vxlan6_gpe_input_node.index, 0 /* is_ip4 */);
   return 0;
 }

 VLIB_INIT_FUNCTION(vxlan_gpe_init);
	/*
	* Copyright (c) 2015 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/vxlan-gpe/vxlan_gpe.h>
	#include <vnet/ip/format.h>

	vxlan_gpe_main_t vxlan_gpe_main;

	u8 * format_vxlan_gpe_tunnel (u8 * s, va_list * args)
	{
	vxlan_gpe_tunnel_t * t = va_arg (args, vxlan_gpe_tunnel_t );
	vxlan_gpe_main_t * gm = &vxlan_gpe_main;

	s = format (s, "[%d] local: %U remote: %U ",
	t - gm->tunnels,
	format_ip46_address, &t->local, IP46_TYPE_ANY,
	format_ip46_address, &t->remote, IP46_TYPE_ANY);

	s = format (s, " vxlan VNI %d ", t->vni);

	switch (t->protocol)
	{
	case VXLAN_GPE_PROTOCOL_IP4:
	s = format (s, "next-protocol ip4");
	break;
	case VXLAN_GPE_PROTOCOL_IP6:
	s = format (s, "next-protocol ip6");
	break;
	case VXLAN_GPE_PROTOCOL_ETHERNET:
	s = format (s, "next-protocol ethernet");
	break;
	case VXLAN_GPE_PROTOCOL_NSH:
	s = format (s, "next-protocol nsh");
	break;
	default:
	s = format (s, "next-protocol unknown %d", t->protocol);
	}

	s = format (s, " fibs: (encap %d, decap %d)",
	t->encap_fib_index,
	t->decap_fib_index);

	return s;
	}

	static u8 * format_vxlan_gpe_name (u8 * s, va_list * args)
	{
	u32 dev_instance = va_arg (*args, u32);
	return format (s, "vxlan_gpe_tunnel%d", dev_instance);
	}


	static uword dummy_interface_tx (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * frame)
	{
	clib_warning ("you shouldn't be here, leaking buffers...");
	return frame->n_vectors;
	}
	static clib_error_t *
	vxlan_gpe_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
	{
	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);

	return 0;
	}

	VNET_DEVICE_CLASS (vxlan_gpe_device_class,static) = {
	.name = "VXLAN_GPE",
	.format_device_name = format_vxlan_gpe_name,
	.format_tx_trace = format_vxlan_gpe_encap_trace,
	.tx_function = dummy_interface_tx,
	.admin_up_down_function = vxlan_gpe_interface_admin_up_down,
	};

	static uword dummy_set_rewrite (vnet_main_t * vnm,
	u32 sw_if_index,
	u32 l3_type,
	void * dst_address,
	void * rewrite,
	uword max_rewrite_bytes)
	{
	return 0;
	}


	static u8 * format_vxlan_gpe_header_with_length (u8 * s, va_list * args)
	{
	u32 dev_instance = va_arg (*args, u32);
	s = format (s, "unimplemented dev %u", dev_instance);
	return s;
	}

	VNET_HW_INTERFACE_CLASS (vxlan_gpe_hw_class) = {
	.name = "VXLAN_GPE",
	.format_header = format_vxlan_gpe_header_with_length,
	.set_rewrite = dummy_set_rewrite,
	};


	#define foreach_gpe_copy_field \
	_(vni) \
	_(protocol) \
	_(encap_fib_index) \
	_(decap_fib_index)

	#define foreach_copy_ipv4 { \
	_(local.ip4.as_u32) \
	_(remote.ip4.as_u32) \
	}

	#define foreach_copy_ipv6 { \
	_(local.ip6.as_u64[0]) \
	_(local.ip6.as_u64[1]) \
	_(remote.ip6.as_u64[0]) \
	_(remote.ip6.as_u64[1]) \
	}


	static int vxlan4_gpe_rewrite (vxlan_gpe_tunnel_t * t)
	{
	u8 *rw = 0;
	ip4_header_t * ip0;
	ip4_vxlan_gpe_header_t * h0;
	int len;

	len = sizeof (*h0);

	vec_validate_aligned (rw, len-1, CLIB_CACHE_LINE_BYTES);

	h0 = (ip4_vxlan_gpe_header_t *) rw;

	/* Fixed portion of the (outer) ip4 header */
	ip0 = &h0->ip4;
	ip0->ip_version_and_header_length = 0x45;
	ip0->ttl = 254;
	ip0->protocol = IP_PROTOCOL_UDP;

	/* we fix up the ip4 header length and checksum after-the-fact */
	ip0->src_address.as_u32 = t->local.ip4.as_u32;
	ip0->dst_address.as_u32 = t->remote.ip4.as_u32;
	ip0->checksum = ip4_header_checksum (ip0);

	/* UDP header, randomize src port on something, maybe? */
	h0->udp.src_port = clib_host_to_net_u16 (4790);
	h0->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_vxlan_gpe);

	/* VXLAN header. Are we having fun yet? */
	h0->vxlan.flags = VXLAN_GPE_FLAGS_I \| VXLAN_GPE_FLAGS_P;
	h0->vxlan.ver_res = VXLAN_GPE_VERSION;
	h0->vxlan.protocol = t->protocol;
	h0->vxlan.vni_res = clib_host_to_net_u32 (t->vni<<8);

	t->rewrite = rw;
	return (0);
	}

	static int vxlan6_gpe_rewrite (vxlan_gpe_tunnel_t * t)
	{
	u8 *rw = 0;
	ip6_header_t * ip0;
	ip6_vxlan_gpe_header_t * h0;
	int len;

	len = sizeof (*h0);

	vec_validate_aligned (rw, len-1, CLIB_CACHE_LINE_BYTES);

	h0 = (ip6_vxlan_gpe_header_t *) rw;

	/* Fixed portion of the (outer) ip4 header */
	ip0 = &h0->ip6;
	ip0->ip_version_traffic_class_and_flow_label = clib_host_to_net_u32(6 << 28);
	ip0->hop_limit = 255;
	ip0->protocol = IP_PROTOCOL_UDP;

	ip0->src_address.as_u64[0] = t->local.ip6.as_u64[0];
	ip0->src_address.as_u64[1] = t->local.ip6.as_u64[1];
	ip0->dst_address.as_u64[0] = t->remote.ip6.as_u64[0];
	ip0->dst_address.as_u64[1] = t->remote.ip6.as_u64[1];

	/* UDP header, randomize src port on something, maybe? */
	h0->udp.src_port = clib_host_to_net_u16 (4790);
	h0->udp.dst_port = clib_host_to_net_u16 (UDP_DST_PORT_vxlan_gpe);

	/* VXLAN header. Are we having fun yet? */
	h0->vxlan.flags = VXLAN_GPE_FLAGS_I \| VXLAN_GPE_FLAGS_P;
	h0->vxlan.ver_res = VXLAN_GPE_VERSION;
	h0->vxlan.protocol = t->protocol;
	h0->vxlan.vni_res = clib_host_to_net_u32 (t->vni<<8);

	t->rewrite = rw;
	return (0);
	}

	int vnet_vxlan_gpe_add_del_tunnel
	(vnet_vxlan_gpe_add_del_tunnel_args_t a, u32 sw_if_indexp)
	{
	vxlan_gpe_main_t * gm = &vxlan_gpe_main;
	vxlan_gpe_tunnel_t *t = 0;
	vnet_main_t * vnm = gm->vnet_main;
	vnet_hw_interface_t * hi;
	uword * p;
	u32 hw_if_index = ~0;
	u32 sw_if_index = ~0;
	int rv;
	vxlan4_gpe_tunnel_key_t key4, *key4_copy;
	vxlan6_gpe_tunnel_key_t key6, *key6_copy;
	hash_pair_t *hp;

	if (!a->is_ip6)
	{
	key4.local = a->local.ip4.as_u32;
	key4.remote = a->remote.ip4.as_u32;
	key4.vni = clib_host_to_net_u32 (a->vni << 8);
	key4.pad = 0;

	p = hash_get_mem(gm->vxlan4_gpe_tunnel_by_key, &key4);
	}
	else
	{
	key6.local.as_u64[0] = a->local.ip6.as_u64[0];
	key6.local.as_u64[1] = a->local.ip6.as_u64[1];
	key6.remote.as_u64[0] = a->remote.ip6.as_u64[0];
	key6.remote.as_u64[1] = a->remote.ip6.as_u64[1];
	key6.vni = clib_host_to_net_u32 (a->vni << 8);

	p = hash_get_mem(gm->vxlan6_gpe_tunnel_by_key, &key6);
	}

	if (a->is_add)
	{
	/* adding a tunnel: tunnel must not already exist */
	if (p)
	return VNET_API_ERROR_INVALID_VALUE;

	pool_get_aligned (gm->tunnels, t, CLIB_CACHE_LINE_BYTES);
	memset (t, 0, sizeof (*t));

	/* copy from arg structure */
	#define _(x) t->x = a->x;
	foreach_gpe_copy_field;
	if (!a->is_ip6) foreach_copy_ipv4
	else foreach_copy_ipv6
	#undef _

	if (!a->is_ip6) t->flags \|= VXLAN_GPE_TUNNEL_IS_IPV4;

	if (!a->is_ip6) {
	rv = vxlan4_gpe_rewrite (t);
	} else {
	rv = vxlan6_gpe_rewrite (t);
	}

	if (rv)
	{
	pool_put (gm->tunnels, t);
	return rv;
	}

	if (!a->is_ip6)
	{
	key4_copy = clib_mem_alloc (sizeof (*key4_copy));
	clib_memcpy (key4_copy, &key4, sizeof (*key4_copy));
	hash_set_mem (gm->vxlan4_gpe_tunnel_by_key, key4_copy,
	t - gm->tunnels);
	}
	else
	{
	key6_copy = clib_mem_alloc (sizeof (*key6_copy));
	clib_memcpy (key6_copy, &key6, sizeof (*key6_copy));
	hash_set_mem (gm->vxlan6_gpe_tunnel_by_key, key6_copy,
	t - gm->tunnels);
	}

	if (vec_len (gm->free_vxlan_gpe_tunnel_hw_if_indices) > 0)
	{
	hw_if_index = gm->free_vxlan_gpe_tunnel_hw_if_indices
	[vec_len (gm->free_vxlan_gpe_tunnel_hw_if_indices)-1];
	_vec_len (gm->free_vxlan_gpe_tunnel_hw_if_indices) -= 1;

	hi = vnet_get_hw_interface (vnm, hw_if_index);
	hi->dev_instance = t - gm->tunnels;
	hi->hw_instance = hi->dev_instance;
	}
	else
	{
	hw_if_index = vnet_register_interface
	(vnm, vxlan_gpe_device_class.index, t - gm->tunnels,
	vxlan_gpe_hw_class.index, t - gm->tunnels);
	hi = vnet_get_hw_interface (vnm, hw_if_index);
	hi->output_node_index = vxlan_gpe_encap_node.index;
	}

	t->hw_if_index = hw_if_index;
	t->sw_if_index = sw_if_index = hi->sw_if_index;
	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 - gm->tunnels;

	vnet_sw_interface_set_flags (vnm, hi->sw_if_index,
	VNET_SW_INTERFACE_FLAG_ADMIN_UP);
	}
	else
	{
	/* deleting a tunnel: tunnel must exist */
	if (!p)
	return VNET_API_ERROR_NO_SUCH_ENTRY;

	t = pool_elt_at_index (gm->tunnels, p[0]);

	vnet_sw_interface_set_flags (vnm, t->sw_if_index, 0 /* down */);
	vec_add1 (gm->free_vxlan_gpe_tunnel_hw_if_indices, t->hw_if_index);

	gm->tunnel_index_by_sw_if_index[t->sw_if_index] = ~0;

	if (!a->is_ip6)
	{
	hp = hash_get_pair (gm->vxlan4_gpe_tunnel_by_key, &key4);
	key4_copy = (void *)(hp->key);
	hash_unset_mem (gm->vxlan4_gpe_tunnel_by_key, &key4);
	clib_mem_free (key4_copy);
	}
	else
	{
	hp = hash_get_pair (gm->vxlan6_gpe_tunnel_by_key, &key6);
	key6_copy = (void *)(hp->key);
	hash_unset_mem (gm->vxlan4_gpe_tunnel_by_key, &key6);
	clib_mem_free (key6_copy);
	}

	vec_free (t->rewrite);
	pool_put (gm->tunnels, t);
	}

	if (sw_if_indexp)
	*sw_if_indexp = sw_if_index;

	return 0;
	}

	static u32 fib4_index_from_fib_id (u32 fib_id)
	{
	ip4_main_t * im = &ip4_main;
	uword * p;

	p = hash_get (im->fib_index_by_table_id, fib_id);
	if (!p)
	return ~0;

	return p[0];
	}

	static u32 fib6_index_from_fib_id (u32 fib_id)
	{
	ip6_main_t * im = &ip6_main;
	uword * p;

	p = hash_get (im->fib_index_by_table_id, fib_id);
	if (!p)
	return ~0;

	return p[0];
	}

	static clib_error_t *
	vxlan_gpe_add_del_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;
	u8 is_add = 1;
	ip46_address_t local, remote;
	u8 local_set = 0;
	u8 remote_set = 0;
	u8 ipv4_set = 0;
	u8 ipv6_set = 0;
	u32 encap_fib_index = 0;
	u32 decap_fib_index = 0;
	u8 protocol = VXLAN_GPE_PROTOCOL_IP4;
	u32 vni;
	u8 vni_set = 0;
	int rv;
	u32 tmp;
	vnet_vxlan_gpe_add_del_tunnel_args_t _a, * a = &_a;
	u32 sw_if_index;

	/* 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, "local %U",
	unformat_ip4_address, &local.ip4))
	{
	local_set = 1;
	ipv4_set = 1;
	}
	else if (unformat (line_input, "remote %U",
	unformat_ip4_address, &remote.ip4))
	{
	remote_set = 1;
	ipv4_set = 1;
	}
	else if (unformat (line_input, "local %U",
	unformat_ip6_address, &local.ip6))
	{
	local_set = 1;
	ipv6_set = 1;
	}
	else if (unformat (line_input, "remote %U",
	unformat_ip6_address, &remote.ip6))
	{
	remote_set = 1;
	ipv6_set = 1;
	}
	else if (unformat (line_input, "encap-vrf-id %d", &tmp))
	{
	if (ipv6_set)
	encap_fib_index = fib6_index_from_fib_id (tmp);
	else
	encap_fib_index = fib4_index_from_fib_id (tmp);

	if (encap_fib_index == ~0)
	return clib_error_return (0, "nonexistent encap fib id %d", tmp);
	}
	else if (unformat (line_input, "decap-vrf-id %d", &tmp))
	{

	if (ipv6_set)
	decap_fib_index = fib6_index_from_fib_id (tmp);
	else
	decap_fib_index = fib4_index_from_fib_id (tmp);

	if (decap_fib_index == ~0)
	return clib_error_return (0, "nonexistent decap fib id %d", tmp);
	}
	else if (unformat (line_input, "vni %d", &vni))
	vni_set = 1;
	else if (unformat(line_input, "next-ip4"))
	protocol = VXLAN_GPE_PROTOCOL_IP4;
	else if (unformat(line_input, "next-ip6"))
	protocol = VXLAN_GPE_PROTOCOL_IP6;
	else if (unformat(line_input, "next-ethernet"))
	protocol = VXLAN_GPE_PROTOCOL_ETHERNET;
	else if (unformat(line_input, "next-nsh"))
	protocol = VXLAN_GPE_PROTOCOL_NSH;
	else
	return clib_error_return (0, "parse error: '%U'",
	format_unformat_error, line_input);
	}

	unformat_free (line_input);

	if (local_set == 0)
	return clib_error_return (0, "tunnel local address not specified");

	if (remote_set == 0)
	return clib_error_return (0, "tunnel remote address not specified");

	if (ipv4_set && ipv6_set)
	return clib_error_return (0, "both IPv4 and IPv6 addresses specified");

	if ((ipv4_set && memcmp(&local.ip4, &remote.ip4, sizeof(local.ip4)) == 0) \|\|
	(ipv6_set && memcmp(&local.ip6, &remote.ip6, sizeof(local.ip6)) == 0))
	return clib_error_return (0, "src and dst addresses are identical");

	if (vni_set == 0)
	return clib_error_return (0, "vni not specified");

	memset (a, 0, sizeof (*a));

	a->is_add = is_add;
	a->is_ip6 = ipv6_set;

	#define _(x) a->x = x;
	foreach_gpe_copy_field;
	if (ipv4_set) foreach_copy_ipv4
	else foreach_copy_ipv6
	#undef _

	rv = vnet_vxlan_gpe_add_del_tunnel (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_INVALID_DECAP_NEXT:
	return clib_error_return (0, "invalid decap-next...");

	case VNET_API_ERROR_TUNNEL_EXIST:
	return clib_error_return (0, "tunnel already exists...");

	case VNET_API_ERROR_NO_SUCH_ENTRY:
	return clib_error_return (0, "tunnel does not exist...");

	default:
	return clib_error_return
	(0, "vnet_vxlan_gpe_add_del_tunnel returned %d", rv);
	}

	return 0;
	}

	VLIB_CLI_COMMAND (create_vxlan_gpe_tunnel_command, static) = {
	.path = "create vxlan-gpe tunnel",
	.short_help =
	"create vxlan-gpe tunnel local <local-addr> remote <remote-addr>"
	" vni <nn> [next-ip4][next-ip6][next-ethernet][next-nsh]"
	" [encap-vrf-id <nn>] [decap-vrf-id <nn>]"
	" [del]\n",
	.function = vxlan_gpe_add_del_tunnel_command_fn,
	};

	static clib_error_t *
	show_vxlan_gpe_tunnel_command_fn (vlib_main_t * vm,
	unformat_input_t * input,
	vlib_cli_command_t * cmd)
	{
	vxlan_gpe_main_t * gm = &vxlan_gpe_main;
	vxlan_gpe_tunnel_t * t;

	if (pool_elts (gm->tunnels) == 0)
	vlib_cli_output (vm, "No vxlan-gpe tunnels configured.");

	pool_foreach (t, gm->tunnels,
	({
	vlib_cli_output (vm, "%U", format_vxlan_gpe_tunnel, t);
	}));

	return 0;
	}

	VLIB_CLI_COMMAND (show_vxlan_gpe_tunnel_command, static) = {
	.path = "show vxlan-gpe",
	.function = show_vxlan_gpe_tunnel_command_fn,
	};

	clib_error_t vxlan_gpe_init (vlib_main_t vm)
	{
	vxlan_gpe_main_t *gm = &vxlan_gpe_main;

	gm->vnet_main = vnet_get_main();
	gm->vlib_main = vm;

	gm->vxlan4_gpe_tunnel_by_key
	= hash_create_mem (0, sizeof(vxlan4_gpe_tunnel_key_t), sizeof (uword));

	gm->vxlan6_gpe_tunnel_by_key
	= hash_create_mem (0, sizeof(vxlan6_gpe_tunnel_key_t), sizeof (uword));


	udp_register_dst_port (vm, UDP_DST_PORT_vxlan_gpe,
	vxlan4_gpe_input_node.index, 1 /* is_ip4 */);
	udp_register_dst_port (vm, UDP_DST_PORT_vxlan6_gpe,
	vxlan6_gpe_input_node.index, 0 /* is_ip4 */);
	return 0;
	}

	VLIB_INIT_FUNCTION(vxlan_gpe_init);