gtpu.c

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/*
 *------------------------------------------------------------------
 * Copyright (c) 2017 Intel 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 <stdint.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <inttypes.h>

#include <vlib/vlib.h>
#include <vlib/unix/unix.h>
#include <vnet/ethernet/ethernet.h>
#include <vnet/fib/fib_entry.h>
#include <vnet/fib/fib_table.h>
#include <vnet/mfib/mfib_table.h>
#include <vnet/adj/adj_mcast.h>
#include <vnet/dpo/dpo.h>
#include <vnet/plugin/plugin.h>
#include <vpp/app/version.h>
#include <gtpu/gtpu.h>


gtpu_main_t gtpu_main;

/* *INDENT-OFF* */
VNET_FEATURE_INIT (ip4_gtpu_bypass, static) = {
  .arc_name = "ip4-unicast",
  .node_name = "ip4-gtpu-bypass",
  .runs_before = VNET_FEATURES ("ip4-lookup"),
};

VNET_FEATURE_INIT (ip6_gtpu_bypass, static) = {
  .arc_name = "ip6-unicast",
  .node_name = "ip6-gtpu-bypass",
  .runs_before = VNET_FEATURES ("ip6-lookup"),
};
/* *INDENT-on* */

u8 * format_gtpu_encap_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 *);
  gtpu_encap_trace_t * t
      = va_arg (*args, gtpu_encap_trace_t *);

  s = format (s, "GTPU encap to gtpu_tunnel%d teid %d",
              t->tunnel_index, t->teid);
  return s;
}

static u8 *
format_decap_next (u8 * s, va_list * args)
{
  u32 next_index = va_arg (*args, u32);

  switch (next_index)
    {
    case GTPU_INPUT_NEXT_DROP:
      return format (s, "drop");
    case GTPU_INPUT_NEXT_L2_INPUT:
      return format (s, "l2");
    case GTPU_INPUT_NEXT_IP4_INPUT:
      return format (s, "ip4");
    case GTPU_INPUT_NEXT_IP6_INPUT:
      return format (s, "ip6");
    default:
      return format (s, "index %d", next_index);
    }
  return s;
}

u8 *
format_gtpu_tunnel (u8 * s, va_list * args)
{
  gtpu_tunnel_t *t = va_arg (*args, gtpu_tunnel_t *);
  gtpu_main_t *ngm = &gtpu_main;

  s = format (s, "[%d] src %U dst %U teid %d fib-idx %d sw-if-idx %d ",
              t - ngm->tunnels,
              format_ip46_address, &t->src, IP46_TYPE_ANY,
              format_ip46_address, &t->dst, IP46_TYPE_ANY,
              t->teid,  t->encap_fib_index, t->sw_if_index);

  s = format (s, "encap-dpo-idx %d ", t->next_dpo.dpoi_index);
  s = format (s, "decap-next-%U ", format_decap_next, t->decap_next_index);

  if (PREDICT_FALSE (ip46_address_is_multicast (&t->dst)))
    s = format (s, "mcast-sw-if-idx %d ", t->mcast_sw_if_index);

  return s;
}

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

static clib_error_t *
gtpu_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
{
  u32 hw_flags = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) ?
    VNET_HW_INTERFACE_FLAG_LINK_UP : 0;
  vnet_hw_interface_set_flags (vnm, hw_if_index, hw_flags);

  return /* no error */ 0;
}

/* *INDENT-OFF* */
VNET_DEVICE_CLASS (gtpu_device_class,static) = {
  .name = "GTPU",
  .format_device_name = format_gtpu_name,
  .format_tx_trace = format_gtpu_encap_trace,
  .admin_up_down_function = gtpu_interface_admin_up_down,
};
/* *INDENT-ON* */

static u8 *
format_gtpu_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;
}

/* *INDENT-OFF* */
VNET_HW_INTERFACE_CLASS (gtpu_hw_class) =
{
  .name = "GTPU",
  .format_header = format_gtpu_header_with_length,
  .build_rewrite = default_build_rewrite,
  .flags = VNET_HW_INTERFACE_CLASS_FLAG_P2P,
};
/* *INDENT-ON* */

static void
gtpu_tunnel_restack_dpo (gtpu_tunnel_t * t)
{
  dpo_id_t dpo = DPO_INVALID;
  u32 encap_index = ip46_address_is_ip4 (&t->dst) ?
    gtpu4_encap_node.index : gtpu6_encap_node.index;
  fib_forward_chain_type_t forw_type = ip46_address_is_ip4 (&t->dst) ?
    FIB_FORW_CHAIN_TYPE_UNICAST_IP4 : FIB_FORW_CHAIN_TYPE_UNICAST_IP6;

  fib_entry_contribute_forwarding (t->fib_entry_index, forw_type, &dpo);
  dpo_stack_from_node (encap_index, &t->next_dpo, &dpo);
  dpo_reset (&dpo);
}

static gtpu_tunnel_t *
gtpu_tunnel_from_fib_node (fib_node_t * node)
{
  return ((gtpu_tunnel_t *) (((char *) node) -
                             STRUCT_OFFSET_OF (gtpu_tunnel_t, node)));
}

/**
 * Function definition to backwalk a FIB node -
 * Here we will restack the new dpo of GTPU DIP to encap node.
 */
static fib_node_back_walk_rc_t
gtpu_tunnel_back_walk (fib_node_t * node, fib_node_back_walk_ctx_t * ctx)
{
  gtpu_tunnel_restack_dpo (gtpu_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 *
gtpu_tunnel_fib_node_get (fib_node_index_t index)
{
  gtpu_tunnel_t *t;
  gtpu_main_t *gtm = &gtpu_main;

  t = pool_elt_at_index (gtm->tunnels, index);

  return (&t->node);
}

/**
 * Function definition to inform the FIB node that its last lock has gone.
 */
static void
gtpu_tunnel_last_lock_gone (fib_node_t * node)
{
  /*
   * The GTPU 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 GTPU tunnels
 * for participation in the FIB object graph.
 */
const static fib_node_vft_t gtpu_vft = {
  .fnv_get = gtpu_tunnel_fib_node_get,
  .fnv_last_lock = gtpu_tunnel_last_lock_gone,
  .fnv_back_walk = gtpu_tunnel_back_walk,
};


#define foreach_copy_field                      \
_(teid)                                          \
_(mcast_sw_if_index)                            \
_(encap_fib_index)                              \
_(decap_next_index)                             \
_(src)                                          \
_(dst)

static void
ip_udp_gtpu_rewrite (gtpu_tunnel_t * t, bool is_ip6)
{
  union
  {
    ip4_gtpu_header_t *h4;
    ip6_gtpu_header_t *h6;
    u8 *rw;
  } r =
  {
  .rw = 0};
  int len = is_ip6 ? sizeof *r.h6 : sizeof *r.h4;

  vec_validate_aligned (r.rw, len - 1, CLIB_CACHE_LINE_BYTES);

  udp_header_t *udp;
  gtpu_header_t *gtpu;
  /* Fixed portion of the (outer) ip header */
  if (!is_ip6)
    {
      ip4_header_t *ip = &r.h4->ip4;
      udp = &r.h4->udp;
      gtpu = &r.h4->gtpu;
      ip->ip_version_and_header_length = 0x45;
      ip->ttl = 254;
      ip->protocol = IP_PROTOCOL_UDP;

      ip->src_address = t->src.ip4;
      ip->dst_address = t->dst.ip4;

      /* we fix up the ip4 header length and checksum after-the-fact */
      ip->checksum = ip4_header_checksum (ip);
    }
  else
    {
      ip6_header_t *ip = &r.h6->ip6;
      udp = &r.h6->udp;
      gtpu = &r.h6->gtpu;
      ip->ip_version_traffic_class_and_flow_label =
        clib_host_to_net_u32 (6 << 28);
      ip->hop_limit = 255;
      ip->protocol = IP_PROTOCOL_UDP;

      ip->src_address = t->src.ip6;
      ip->dst_address = t->dst.ip6;
    }

  /* UDP header, randomize src port on something, maybe? */
  udp->src_port = clib_host_to_net_u16 (2152);
  udp->dst_port = clib_host_to_net_u16 (UDP_DST_PORT_GTPU);

  /* GTPU header */
  gtpu->ver_flags = GTPU_V1_VER | GTPU_PT_GTP;
  gtpu->type = GTPU_TYPE_GTPU;
  gtpu->teid = clib_host_to_net_u32 (t->teid);

  t->rewrite = r.rw;
  /* Now only support 8-byte gtpu header. TBD */
  _vec_len (t->rewrite) = sizeof (ip4_gtpu_header_t) - 4;

  return;
}

static bool
gtpu_decap_next_is_valid (gtpu_main_t * gtm, u32 is_ip6, u32 decap_next_index)
{
  vlib_main_t *vm = gtm->vlib_main;
  u32 input_idx = (!is_ip6) ? gtpu4_input_node.index : gtpu6_input_node.index;
  vlib_node_runtime_t *r = vlib_node_get_runtime (vm, input_idx);

  return decap_next_index < r->n_next_nodes;
}

static uword
vtep_addr_ref (ip46_address_t * ip)
{
  uword *vtep = ip46_address_is_ip4 (ip) ?
    hash_get (gtpu_main.vtep4, ip->ip4.as_u32) :
    hash_get_mem (gtpu_main.vtep6, &ip->ip6);
  if (vtep)
    return ++(*vtep);
  ip46_address_is_ip4 (ip) ?
    hash_set (gtpu_main.vtep4, ip->ip4.as_u32, 1) :
    hash_set_mem_alloc (&gtpu_main.vtep6, &ip->ip6, 1);
  return 1;
}

static uword
vtep_addr_unref (ip46_address_t * ip)
{
  uword *vtep = ip46_address_is_ip4 (ip) ?
    hash_get (gtpu_main.vtep4, ip->ip4.as_u32) :
    hash_get_mem (gtpu_main.vtep6, &ip->ip6);
  ASSERT (vtep);
  if (--(*vtep) != 0)
    return *vtep;
  ip46_address_is_ip4 (ip) ?
    hash_unset (gtpu_main.vtep4, ip->ip4.as_u32) :
    hash_unset_mem_free (&gtpu_main.vtep6, &ip->ip6);
  return 0;
}

typedef CLIB_PACKED (union
                     {
                     struct
                     {
                     fib_node_index_t mfib_entry_index;
                     adj_index_t mcast_adj_index;
                     }; u64 as_u64;
                     }) mcast_shared_t;

static inline mcast_shared_t
mcast_shared_get (ip46_address_t * ip)
{
  ASSERT (ip46_address_is_multicast (ip));
  uword *p = hash_get_mem (gtpu_main.mcast_shared, ip);
  ASSERT (p);
  return (mcast_shared_t)
  {
  .as_u64 = *p};
}

static inline void
mcast_shared_add (ip46_address_t * dst, fib_node_index_t mfei, adj_index_t ai)
{
  mcast_shared_t new_ep = {
    .mcast_adj_index = ai,
    .mfib_entry_index = mfei,
  };

  hash_set_mem_alloc (&gtpu_main.mcast_shared, dst, new_ep.as_u64);
}

static inline void
mcast_shared_remove (ip46_address_t * dst)
{
  mcast_shared_t ep = mcast_shared_get (dst);

  adj_unlock (ep.mcast_adj_index);
  mfib_table_entry_delete_index (ep.mfib_entry_index, MFIB_SOURCE_GTPU);

  hash_unset_mem_free (&gtpu_main.mcast_shared, dst);
}

int vnet_gtpu_add_del_tunnel
  (vnet_gtpu_add_del_tunnel_args_t * a, u32 * sw_if_indexp)
{
  gtpu_main_t *gtm = &gtpu_main;
  gtpu_tunnel_t *t = 0;
  vnet_main_t *vnm = gtm->vnet_main;
  uword *p;
  u32 hw_if_index = ~0;
  u32 sw_if_index = ~0;
  gtpu4_tunnel_key_t key4;
  gtpu6_tunnel_key_t key6;
  u32 is_ip6 = a->is_ip6;

  if (!is_ip6)
    {
      key4.src = a->dst.ip4.as_u32;     /* decap src in key is encap dst in config */
      key4.teid = clib_host_to_net_u32 (a->teid);
      p = hash_get (gtm->gtpu4_tunnel_by_key, key4.as_u64);
    }
  else
    {
      key6.src = a->dst.ip6;
      key6.teid = clib_host_to_net_u32 (a->teid);
      p = hash_get_mem (gtm->gtpu6_tunnel_by_key, &key6);
    }

  if (a->is_add)
    {
      l2input_main_t *l2im = &l2input_main;

      /* adding a tunnel: tunnel must not already exist */
      if (p)
        return VNET_API_ERROR_TUNNEL_EXIST;

      /*if not set explicitly, default to l2 */
      if (a->decap_next_index == ~0)
        a->decap_next_index = GTPU_INPUT_NEXT_L2_INPUT;
      if (!gtpu_decap_next_is_valid (gtm, is_ip6, a->decap_next_index))
        return VNET_API_ERROR_INVALID_DECAP_NEXT;

      pool_get_aligned (gtm->tunnels, t, CLIB_CACHE_LINE_BYTES);
      clib_memset (t, 0, sizeof (*t));

      /* copy from arg structure */
#define _(x) t->x = a->x;
      foreach_copy_field;
#undef _

      ip_udp_gtpu_rewrite (t, is_ip6);

      /* copy the key */
      if (is_ip6)
        hash_set_mem_alloc (&gtm->gtpu6_tunnel_by_key, &key6,
                            t - gtm->tunnels);
      else
        hash_set (gtm->gtpu4_tunnel_by_key, key4.as_u64, t - gtm->tunnels);

      vnet_hw_interface_t *hi;
      if (vec_len (gtm->free_gtpu_tunnel_hw_if_indices) > 0)
        {
          vnet_interface_main_t *im = &vnm->interface_main;
          hw_if_index = gtm->free_gtpu_tunnel_hw_if_indices
            [vec_len (gtm->free_gtpu_tunnel_hw_if_indices) - 1];
          _vec_len (gtm->free_gtpu_tunnel_hw_if_indices) -= 1;

          hi = vnet_get_hw_interface (vnm, hw_if_index);
          hi->dev_instance = t - gtm->tunnels;
          hi->hw_instance = hi->dev_instance;

          /* clear old stats of freed tunnel before reuse */
          sw_if_index = hi->sw_if_index;
          vnet_interface_counter_lock (im);
          vlib_zero_combined_counter
            (&im->combined_sw_if_counters[VNET_INTERFACE_COUNTER_TX],
             sw_if_index);
          vlib_zero_combined_counter (&im->combined_sw_if_counters
                                      [VNET_INTERFACE_COUNTER_RX],
                                      sw_if_index);
          vlib_zero_simple_counter (&im->sw_if_counters
                                    [VNET_INTERFACE_COUNTER_DROP],
                                    sw_if_index);
          vnet_interface_counter_unlock (im);
        }
      else
        {
          hw_if_index = vnet_register_interface
            (vnm, gtpu_device_class.index, t - gtm->tunnels,
             gtpu_hw_class.index, t - gtm->tunnels);
          hi = vnet_get_hw_interface (vnm, hw_if_index);
        }

      /* Set gtpu tunnel output node */
      u32 encap_index = !is_ip6 ?
        gtpu4_encap_node.index : gtpu6_encap_node.index;
      vnet_set_interface_output_node (vnm, hw_if_index, encap_index);

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

      vec_validate_init_empty (gtm->tunnel_index_by_sw_if_index, sw_if_index,
                               ~0);
      gtm->tunnel_index_by_sw_if_index[sw_if_index] = t - gtm->tunnels;

      /* setup l2 input config with l2 feature and bd 0 to drop packet */
      vec_validate (l2im->configs, sw_if_index);
      l2im->configs[sw_if_index].feature_bitmap = L2INPUT_FEAT_DROP;
      l2im->configs[sw_if_index].bd_index = 0;

      vnet_sw_interface_t *si = vnet_get_sw_interface (vnm, sw_if_index);
      si->flags &= ~VNET_SW_INTERFACE_FLAG_HIDDEN;
      vnet_sw_interface_set_flags (vnm, sw_if_index,
                                   VNET_SW_INTERFACE_FLAG_ADMIN_UP);

      fib_node_init (&t->node, gtm->fib_node_type);
      fib_prefix_t tun_dst_pfx;
      vnet_flood_class_t flood_class = VNET_FLOOD_CLASS_TUNNEL_NORMAL;

      fib_prefix_from_ip46_addr (&t->dst, &tun_dst_pfx);
      if (!ip46_address_is_multicast (&t->dst))
        {
          /* Unicast tunnel -
           * 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
           */
          vtep_addr_ref (&t->src);
          t->fib_entry_index = fib_table_entry_special_add
            (t->encap_fib_index, &tun_dst_pfx, FIB_SOURCE_RR,
             FIB_ENTRY_FLAG_NONE);
          t->sibling_index = fib_entry_child_add
            (t->fib_entry_index, gtm->fib_node_type, t - gtm->tunnels);
          gtpu_tunnel_restack_dpo (t);
        }
      else
        {
          /* Multicast tunnel -
           * as the same mcast group can be used for multiple mcast tunnels
           * with different VNIs, create the output adjacency only if
           * it does not already exist
           */
          fib_protocol_t fp = fib_ip_proto (is_ip6);

          if (vtep_addr_ref (&t->dst) == 1)
            {
              fib_node_index_t mfei;
              adj_index_t ai;
              fib_route_path_t path = {
                .frp_proto = fib_proto_to_dpo (fp),
                .frp_addr = zero_addr,
                .frp_sw_if_index = 0xffffffff,
                .frp_fib_index = ~0,
                .frp_weight = 0,
                .frp_flags = FIB_ROUTE_PATH_LOCAL,
              };
              const mfib_prefix_t mpfx = {
                .fp_proto = fp,
                .fp_len = (is_ip6 ? 128 : 32),
                .fp_grp_addr = tun_dst_pfx.fp_addr,
              };

              /*
               * Setup the (*,G) to receive traffic on the mcast group
               *  - the forwarding interface is for-us
               *  - the accepting interface is that from the API
               */
              mfib_table_entry_path_update (t->encap_fib_index,
                                            &mpfx,
                                            MFIB_SOURCE_GTPU,
                                            &path, MFIB_ITF_FLAG_FORWARD);

              path.frp_sw_if_index = a->mcast_sw_if_index;
              path.frp_flags = FIB_ROUTE_PATH_FLAG_NONE;
              mfei = mfib_table_entry_path_update (t->encap_fib_index,
                                                   &mpfx,
                                                   MFIB_SOURCE_GTPU,
                                                   &path,
                                                   MFIB_ITF_FLAG_ACCEPT);

              /*
               * Create the mcast adjacency to send traffic to the group
               */
              ai = adj_mcast_add_or_lock (fp,
                                          fib_proto_to_link (fp),
                                          a->mcast_sw_if_index);

              /*
               * create a new end-point
               */
              mcast_shared_add (&t->dst, mfei, ai);
            }

          dpo_id_t dpo = DPO_INVALID;
          mcast_shared_t ep = mcast_shared_get (&t->dst);

          /* Stack shared mcast dst mac addr rewrite on encap */
          dpo_set (&dpo, DPO_ADJACENCY_MCAST,
                   fib_proto_to_dpo (fp), ep.mcast_adj_index);

          dpo_stack_from_node (encap_index, &t->next_dpo, &dpo);

          dpo_reset (&dpo);
          flood_class = VNET_FLOOD_CLASS_TUNNEL_MASTER;
        }

      vnet_get_sw_interface (vnet_get_main (), sw_if_index)->flood_class =
        flood_class;
    }
  else
    {
      /* deleting a tunnel: tunnel must exist */
      if (!p)
        return VNET_API_ERROR_NO_SUCH_ENTRY;

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

      vnet_sw_interface_set_flags (vnm, t->sw_if_index, 0 /* down */ );
      vnet_sw_interface_t *si = vnet_get_sw_interface (vnm, t->sw_if_index);
      si->flags |= VNET_SW_INTERFACE_FLAG_HIDDEN;

      /* make sure tunnel is removed from l2 bd or xconnect */
      set_int_l2_mode (gtm->vlib_main, vnm, MODE_L3, t->sw_if_index, 0,
                       L2_BD_PORT_TYPE_NORMAL, 0, 0);
      vec_add1 (gtm->free_gtpu_tunnel_hw_if_indices, t->hw_if_index);

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

      if (!is_ip6)
        hash_unset (gtm->gtpu4_tunnel_by_key, key4.as_u64);
      else
        hash_unset_mem_free (&gtm->gtpu6_tunnel_by_key, &key6);

      if (!ip46_address_is_multicast (&t->dst))
        {
          vtep_addr_unref (&t->src);
          fib_entry_child_remove (t->fib_entry_index, t->sibling_index);
          fib_table_entry_delete_index (t->fib_entry_index, FIB_SOURCE_RR);
        }
      else if (vtep_addr_unref (&t->dst) == 0)
        {
          mcast_shared_remove (&t->dst);
        }

      fib_node_deinit (&t->node);
      vec_free (t->rewrite);
      pool_put (gtm->tunnels, t);
    }

  if (sw_if_indexp)
    *sw_if_indexp = sw_if_index;

  return 0;
}

static uword
get_decap_next_for_node (u32 node_index, u32 ipv4_set)
{
  gtpu_main_t *gtm = &gtpu_main;
  vlib_main_t *vm = gtm->vlib_main;
  uword input_node = (ipv4_set) ? gtpu4_input_node.index :
    gtpu6_input_node.index;

  return vlib_node_add_next (vm, input_node, node_index);
}

static uword
unformat_decap_next (unformat_input_t * input, va_list * args)
{
  u32 *result = va_arg (*args, u32 *);
  u32 ipv4_set = va_arg (*args, int);
  gtpu_main_t *gtm = &gtpu_main;
  vlib_main_t *vm = gtm->vlib_main;
  u32 node_index;
  u32 tmp;

  if (unformat (input, "l2"))
    *result = GTPU_INPUT_NEXT_L2_INPUT;
  else if (unformat (input, "ip4"))
    *result = GTPU_INPUT_NEXT_IP4_INPUT;
  else if (unformat (input, "ip6"))
    *result = GTPU_INPUT_NEXT_IP6_INPUT;
  else if (unformat (input, "node %U", unformat_vlib_node, vm, &node_index))
    *result = get_decap_next_for_node (node_index, ipv4_set);
  else if (unformat (input, "%d", &tmp))
    *result = tmp;
  else
    return 0;

  return 1;
}

static clib_error_t *
gtpu_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;
  ip46_address_t src, dst;
  u8 is_add = 1;
  u8 src_set = 0;
  u8 dst_set = 0;
  u8 grp_set = 0;
  u8 ipv4_set = 0;
  u8 ipv6_set = 0;
  u32 encap_fib_index = 0;
  u32 mcast_sw_if_index = ~0;
  u32 decap_next_index = GTPU_INPUT_NEXT_L2_INPUT;
  u32 teid = 0;
  u32 tmp;
  int rv;
  vnet_gtpu_add_del_tunnel_args_t _a, *a = &_a;
  u32 tunnel_sw_if_index;
  clib_error_t *error = NULL;

  /* Cant "universally zero init" (={0}) due to GCC bug 53119 */
  clib_memset (&src, 0, sizeof src);
  clib_memset (&dst, 0, sizeof dst);

  /* 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, "src %U",
                         unformat_ip4_address, &src.ip4))
        {
          src_set = 1;
          ipv4_set = 1;
        }
      else if (unformat (line_input, "dst %U",
                         unformat_ip4_address, &dst.ip4))
        {
          dst_set = 1;
          ipv4_set = 1;
        }
      else if (unformat (line_input, "src %U",
                         unformat_ip6_address, &src.ip6))
        {
          src_set = 1;
          ipv6_set = 1;
        }
      else if (unformat (line_input, "dst %U",
                         unformat_ip6_address, &dst.ip6))
        {
          dst_set = 1;
          ipv6_set = 1;
        }
      else if (unformat (line_input, "group %U %U",
                         unformat_ip4_address, &dst.ip4,
                         unformat_vnet_sw_interface,
                         vnet_get_main (), &mcast_sw_if_index))
        {
          grp_set = dst_set = 1;
          ipv4_set = 1;
        }
      else if (unformat (line_input, "group %U %U",
                         unformat_ip6_address, &dst.ip6,
                         unformat_vnet_sw_interface,
                         vnet_get_main (), &mcast_sw_if_index))
        {
          grp_set = dst_set = 1;
          ipv6_set = 1;
        }
      else if (unformat (line_input, "encap-vrf-id %d", &tmp))
        {
          encap_fib_index = fib_table_find (fib_ip_proto (ipv6_set), tmp);
          if (encap_fib_index == ~0)
            {
              error =
                clib_error_return (0, "nonexistent encap-vrf-id %d", tmp);
              goto done;
            }
        }
      else if (unformat (line_input, "decap-next %U", unformat_decap_next,
                         &decap_next_index, ipv4_set))
        ;
      else if (unformat (line_input, "teid %d", &teid))
        ;
      else
        {
          error = clib_error_return (0, "parse error: '%U'",
                                     format_unformat_error, line_input);
          goto done;
        }
    }

  if (src_set == 0)
    {
      error = clib_error_return (0, "tunnel src address not specified");
      goto done;
    }

  if (dst_set == 0)
    {
      error = clib_error_return (0, "tunnel dst address not specified");
      goto done;
    }

  if (grp_set && !ip46_address_is_multicast (&dst))
    {
      error = clib_error_return (0, "tunnel group address not multicast");
      goto done;
    }

  if (grp_set == 0 && ip46_address_is_multicast (&dst))
    {
      error = clib_error_return (0, "dst address must be unicast");
      goto done;
    }

  if (grp_set && mcast_sw_if_index == ~0)
    {
      error = clib_error_return (0, "tunnel nonexistent multicast device");
      goto done;
    }

  if (ipv4_set && ipv6_set)
    {
      error = clib_error_return (0, "both IPv4 and IPv6 addresses specified");
      goto done;
    }

  if (ip46_address_cmp (&src, &dst) == 0)
    {
      error = clib_error_return (0, "src and dst addresses are identical");
      goto done;
    }

  if (decap_next_index == ~0)
    {
      error = clib_error_return (0, "next node not found");
      goto done;
    }

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

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

#define _(x) a->x = x;
  foreach_copy_field;
#undef _

  rv = vnet_gtpu_add_del_tunnel (a, &tunnel_sw_if_index);

  switch (rv)
    {
    case 0:
      if (is_add)
        vlib_cli_output (vm, "%U\n", format_vnet_sw_if_index_name,
                         vnet_get_main (), tunnel_sw_if_index);
      break;

    case VNET_API_ERROR_TUNNEL_EXIST:
      error = clib_error_return (0, "tunnel already exists...");
      goto done;

    case VNET_API_ERROR_NO_SUCH_ENTRY:
      error = clib_error_return (0, "tunnel does not exist...");
      goto done;

    default:
      error = clib_error_return
        (0, "vnet_gtpu_add_del_tunnel returned %d", rv);
      goto done;
    }

done:
  unformat_free (line_input);

  return error;
}

/*?
 * Add or delete a GTPU Tunnel.
 *
 * GTPU provides the features needed to allow L2 bridge domains (BDs)
 * to span multiple servers. This is done by building an L2 overlay on
 * top of an L3 network underlay using GTPU tunnels.
 *
 * This makes it possible for servers to be co-located in the same data
 * center or be separated geographically as long as they are reachable
 * through the underlay L3 network.
 *
 * You can refer to this kind of L2 overlay bridge domain as a GTPU
 * (Virtual eXtensible VLAN) segment.
 *
 * @cliexpar
 * Example of how to create a GTPU Tunnel:
 * @cliexcmd{create gtpu tunnel src 10.0.3.1 dst 10.0.3.3 teid 13 encap-vrf-id 7}
 * Example of how to delete a GTPU Tunnel:
 * @cliexcmd{create gtpu tunnel src 10.0.3.1 dst 10.0.3.3 teid 13 del}
 ?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (create_gtpu_tunnel_command, static) = {
  .path = "create gtpu tunnel",
  .short_help =
  "create gtpu tunnel src <local-vtep-addr>"
  " {dst <remote-vtep-addr>|group <mcast-vtep-addr> <intf-name>} teid <nn>"
  " [encap-vrf-id <nn>] [decap-next [l2|ip4|ip6|node <name>]] [del]",
  .function = gtpu_add_del_tunnel_command_fn,
};
/* *INDENT-ON* */

static clib_error_t *
show_gtpu_tunnel_command_fn (vlib_main_t * vm,
                             unformat_input_t * input,
                             vlib_cli_command_t * cmd)
{
  gtpu_main_t *gtm = &gtpu_main;
  gtpu_tunnel_t *t;

  if (pool_elts (gtm->tunnels) == 0)
    vlib_cli_output (vm, "No gtpu tunnels configured...");

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

  return 0;
}

/*?
 * Display all the GTPU Tunnel entries.
 *
 * @cliexpar
 * Example of how to display the GTPU Tunnel entries:
 * @cliexstart{show gtpu tunnel}
 * [0] src 10.0.3.1 dst 10.0.3.3 teid 13 encap_fib_index 0 sw_if_index 5 decap_next l2
 * @cliexend
 ?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (show_gtpu_tunnel_command, static) = {
    .path = "show gtpu tunnel",
    .short_help = "show gtpu tunnel",
    .function = show_gtpu_tunnel_command_fn,
};
/* *INDENT-ON* */

void
vnet_int_gtpu_bypass_mode (u32 sw_if_index, u8 is_ip6, u8 is_enable)
{
  if (is_ip6)
    vnet_feature_enable_disable ("ip6-unicast", "ip6-gtpu-bypass",
                                 sw_if_index, is_enable, 0, 0);
  else
    vnet_feature_enable_disable ("ip4-unicast", "ip4-gtpu-bypass",
                                 sw_if_index, is_enable, 0, 0);
}

static clib_error_t *
set_ip_gtpu_bypass (u32 is_ip6,
                    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 ();
  clib_error_t *error = 0;
  u32 sw_if_index, is_enable;

  sw_if_index = ~0;
  is_enable = 1;

  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat_user
          (line_input, unformat_vnet_sw_interface, vnm, &sw_if_index))
        ;
      else if (unformat (line_input, "del"))
        is_enable = 0;
      else
        {
          error = unformat_parse_error (line_input);
          goto done;
        }
    }

  if (~0 == sw_if_index)
    {
      error = clib_error_return (0, "unknown interface `%U'",
                                 format_unformat_error, line_input);
      goto done;
    }

  vnet_int_gtpu_bypass_mode (sw_if_index, is_ip6, is_enable);

done:
  unformat_free (line_input);

  return error;
}

static clib_error_t *
set_ip4_gtpu_bypass (vlib_main_t * vm,
                     unformat_input_t * input, vlib_cli_command_t * cmd)
{
  return set_ip_gtpu_bypass (0, input, cmd);
}

/*?
 * This command adds the 'ip4-gtpu-bypass' graph node for a given interface.
 * By adding the IPv4 gtpu-bypass graph node to an interface, the node checks
 *  for and validate input gtpu packet and bypass ip4-lookup, ip4-local,
 * ip4-udp-lookup nodes to speedup gtpu packet forwarding. This node will
 * cause extra overhead to for non-gtpu packets which is kept at a minimum.
 *
 * @cliexpar
 * @parblock
 * Example of graph node before ip4-gtpu-bypass is enabled:
 * @cliexstart{show vlib graph ip4-gtpu-bypass}
 *            Name                      Next                    Previous
 * ip4-gtpu-bypass                error-drop [0]
 *                                gtpu4-input [1]
 *                                 ip4-lookup [2]
 * @cliexend
 *
 * Example of how to enable ip4-gtpu-bypass on an interface:
 * @cliexcmd{set interface ip gtpu-bypass GigabitEthernet2/0/0}
 *
 * Example of graph node after ip4-gtpu-bypass is enabled:
 * @cliexstart{show vlib graph ip4-gtpu-bypass}
 *            Name                      Next                    Previous
 * ip4-gtpu-bypass                error-drop [0]               ip4-input
 *                                gtpu4-input [1]        ip4-input-no-checksum
 *                                 ip4-lookup [2]
 * @cliexend
 *
 * Example of how to display the feature enabled on an interface:
 * @cliexstart{show ip interface features GigabitEthernet2/0/0}
 * IP feature paths configured on GigabitEthernet2/0/0...
 * ...
 * ipv4 unicast:
 *   ip4-gtpu-bypass
 *   ip4-lookup
 * ...
 * @cliexend
 *
 * Example of how to disable ip4-gtpu-bypass on an interface:
 * @cliexcmd{set interface ip gtpu-bypass GigabitEthernet2/0/0 del}
 * @endparblock
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (set_interface_ip_gtpu_bypass_command, static) = {
  .path = "set interface ip gtpu-bypass",
  .function = set_ip4_gtpu_bypass,
  .short_help = "set interface ip gtpu-bypass <interface> [del]",
};
/* *INDENT-ON* */

static clib_error_t *
set_ip6_gtpu_bypass (vlib_main_t * vm,
                     unformat_input_t * input, vlib_cli_command_t * cmd)
{
  return set_ip_gtpu_bypass (1, input, cmd);
}

/*?
 * This command adds the 'ip6-gtpu-bypass' graph node for a given interface.
 * By adding the IPv6 gtpu-bypass graph node to an interface, the node checks
 *  for and validate input gtpu packet and bypass ip6-lookup, ip6-local,
 * ip6-udp-lookup nodes to speedup gtpu packet forwarding. This node will
 * cause extra overhead to for non-gtpu packets which is kept at a minimum.
 *
 * @cliexpar
 * @parblock
 * Example of graph node before ip6-gtpu-bypass is enabled:
 * @cliexstart{show vlib graph ip6-gtpu-bypass}
 *            Name                      Next                    Previous
 * ip6-gtpu-bypass                error-drop [0]
 *                                gtpu6-input [1]
 *                                 ip6-lookup [2]
 * @cliexend
 *
 * Example of how to enable ip6-gtpu-bypass on an interface:
 * @cliexcmd{set interface ip6 gtpu-bypass GigabitEthernet2/0/0}
 *
 * Example of graph node after ip6-gtpu-bypass is enabled:
 * @cliexstart{show vlib graph ip6-gtpu-bypass}
 *            Name                      Next                    Previous
 * ip6-gtpu-bypass                error-drop [0]               ip6-input
 *                                gtpu6-input [1]        ip4-input-no-checksum
 *                                 ip6-lookup [2]
 * @cliexend
 *
 * Example of how to display the feature enabled on an interface:
 * @cliexstart{show ip interface features GigabitEthernet2/0/0}
 * IP feature paths configured on GigabitEthernet2/0/0...
 * ...
 * ipv6 unicast:
 *   ip6-gtpu-bypass
 *   ip6-lookup
 * ...
 * @cliexend
 *
 * Example of how to disable ip6-gtpu-bypass on an interface:
 * @cliexcmd{set interface ip6 gtpu-bypass GigabitEthernet2/0/0 del}
 * @endparblock
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (set_interface_ip6_gtpu_bypass_command, static) = {
  .path = "set interface ip6 gtpu-bypass",
  .function = set_ip6_gtpu_bypass,
  .short_help = "set interface ip gtpu-bypass <interface> [del]",
};
/* *INDENT-ON* */

clib_error_t *
gtpu_init (vlib_main_t * vm)
{
  gtpu_main_t *gtm = &gtpu_main;

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

  /* initialize the ip6 hash */
  gtm->gtpu6_tunnel_by_key = hash_create_mem (0,
                                              sizeof (gtpu6_tunnel_key_t),
                                              sizeof (uword));
  gtm->vtep6 = hash_create_mem (0, sizeof (ip6_address_t), sizeof (uword));
  gtm->mcast_shared = hash_create_mem (0,
                                       sizeof (ip46_address_t),
                                       sizeof (mcast_shared_t));

  udp_register_dst_port (vm, UDP_DST_PORT_GTPU,
                         gtpu4_input_node.index, /* is_ip4 */ 1);
  udp_register_dst_port (vm, UDP_DST_PORT_GTPU6,
                         gtpu6_input_node.index, /* is_ip4 */ 0);

  gtm->fib_node_type = fib_node_register_new_type (&gtpu_vft);

  return 0;
}

VLIB_INIT_FUNCTION (gtpu_init);

/* *INDENT-OFF* */
VLIB_PLUGIN_REGISTER () = {
    .version = VPP_BUILD_VER,
    .description = "GPRS Tunnelling Protocol, User Data (GTPv1-U)",
};
/* *INDENT-ON* */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */