ip6_map_t.c

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/*
 * 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 "map.h"

#include <vnet/ip/ip4_to_ip6.h>
#include <vnet/ip/ip6_to_ip4.h>
#include <vnet/ip/ip_frag.h>

typedef enum
{
  IP6_MAPT_NEXT_MAPT_TCP_UDP,
  IP6_MAPT_NEXT_MAPT_ICMP,
  IP6_MAPT_NEXT_MAPT_FRAGMENTED,
  IP6_MAPT_NEXT_DROP,
  IP6_MAPT_N_NEXT
} ip6_mapt_next_t;

typedef enum
{
  IP6_MAPT_ICMP_NEXT_IP4_LOOKUP,
  IP6_MAPT_ICMP_NEXT_IP4_FRAG,
  IP6_MAPT_ICMP_NEXT_DROP,
  IP6_MAPT_ICMP_N_NEXT
} ip6_mapt_icmp_next_t;

typedef enum
{
  IP6_MAPT_TCP_UDP_NEXT_IP4_LOOKUP,
  IP6_MAPT_TCP_UDP_NEXT_IP4_FRAG,
  IP6_MAPT_TCP_UDP_NEXT_DROP,
  IP6_MAPT_TCP_UDP_N_NEXT
} ip6_mapt_tcp_udp_next_t;

typedef enum
{
  IP6_MAPT_FRAGMENTED_NEXT_IP4_LOOKUP,
  IP6_MAPT_FRAGMENTED_NEXT_IP4_FRAG,
  IP6_MAPT_FRAGMENTED_NEXT_DROP,
  IP6_MAPT_FRAGMENTED_N_NEXT
} ip6_mapt_fragmented_next_t;

static_always_inline int
ip6_map_fragment_cache (ip6_header_t * ip6, ip6_frag_hdr_t * frag,
                        map_domain_t * d, u16 port)
{
  u32 *ignore = NULL;
  map_ip4_reass_lock ();
  map_ip4_reass_t *r =
    map_ip4_reass_get (map_get_ip4 (&ip6->src_address, d->ip6_src_len),
                       ip6_map_t_embedded_address (d, &ip6->dst_address),
                       frag_id_6to4 (frag->identification),
                       (ip6->protocol ==
                        IP_PROTOCOL_ICMP6) ? IP_PROTOCOL_ICMP : ip6->protocol,
                       &ignore);
  if (r)
    r->port = port;

  map_ip4_reass_unlock ();
  return !r;
}

/* Returns the associated port or -1 */
static_always_inline i32
ip6_map_fragment_get (ip6_header_t * ip6, ip6_frag_hdr_t * frag,
                      map_domain_t * d)
{
  u32 *ignore = NULL;
  map_ip4_reass_lock ();
  map_ip4_reass_t *r =
    map_ip4_reass_get (map_get_ip4 (&ip6->src_address, d->ip6_src_len),
                       ip6_map_t_embedded_address (d, &ip6->dst_address),
                       frag_id_6to4 (frag->identification),
                       (ip6->protocol ==
                        IP_PROTOCOL_ICMP6) ? IP_PROTOCOL_ICMP : ip6->protocol,
                       &ignore);
  i32 ret = r ? r->port : -1;
  map_ip4_reass_unlock ();
  return ret;
}

typedef struct
{
  map_domain_t *d;
  u16 sender_port;
} icmp6_to_icmp_ctx_t;

static int
ip6_to_ip4_set_icmp_cb (ip6_header_t * ip6, ip4_header_t * ip4, void *arg)
{
  icmp6_to_icmp_ctx_t *ctx = arg;
  u32 ip4_sadr;

  // Security check
  // Note that this prevents an intermediate IPv6 router from answering
  // the request.
  ip4_sadr = map_get_ip4 (&ip6->src_address, ctx->d->flags);
  if (ip6->src_address.as_u64[0] !=
      map_get_pfx_net (ctx->d, ip4_sadr, ctx->sender_port)
      || ip6->src_address.as_u64[1] != map_get_sfx_net (ctx->d, ip4_sadr,
                                                        ctx->sender_port))
    return -1;

  ip4->dst_address.as_u32 =
    ip6_map_t_embedded_address (ctx->d, &ip6->dst_address);
  ip4->src_address.as_u32 = ip4_sadr;

  return 0;
}

static int
ip6_to_ip4_set_inner_icmp_cb (ip6_header_t * ip6, ip4_header_t * ip4,
                              void *arg)
{
  icmp6_to_icmp_ctx_t *ctx = arg;
  u32 inner_ip4_dadr;

  //Security check of inner packet
  inner_ip4_dadr = map_get_ip4 (&ip6->dst_address, ctx->d->flags);
  if (ip6->dst_address.as_u64[0] !=
      map_get_pfx_net (ctx->d, inner_ip4_dadr, ctx->sender_port)
      || ip6->dst_address.as_u64[1] != map_get_sfx_net (ctx->d,
                                                        inner_ip4_dadr,
                                                        ctx->sender_port))
    return -1;

  ip4->dst_address.as_u32 = inner_ip4_dadr;
  ip4->src_address.as_u32 =
    ip6_map_t_embedded_address (ctx->d, &ip6->src_address);

  return 0;
}

static uword
ip6_map_t_icmp (vlib_main_t * vm,
                vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
  vlib_node_runtime_t *error_node =
    vlib_node_get_runtime (vm, ip6_map_t_icmp_node.index);
  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;
  vlib_combined_counter_main_t *cm = map_main.domain_counters;
  u32 thread_index = vm->thread_index;

  while (n_left_from > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 pi0;
          vlib_buffer_t *p0;
          u8 error0;
          ip6_mapt_icmp_next_t next0;
          map_domain_t *d0;
          u16 len0;
          icmp6_to_icmp_ctx_t ctx0;
          ip6_header_t *ip60;

          pi0 = to_next[0] = from[0];
          from += 1;
          n_left_from -= 1;
          to_next += 1;
          n_left_to_next -= 1;
          error0 = MAP_ERROR_NONE;
          next0 = IP6_MAPT_ICMP_NEXT_IP4_LOOKUP;

          p0 = vlib_get_buffer (vm, pi0);
          ip60 = vlib_buffer_get_current (p0);
          len0 = clib_net_to_host_u16 (ip60->payload_length);
          d0 =
            pool_elt_at_index (map_main.domains,
                               vnet_buffer (p0)->map_t.map_domain_index);
          ctx0.sender_port = ip6_get_port (ip60, 0, p0->current_length);
          ctx0.d = d0;
          if (ctx0.sender_port == 0)
            {
              // In case of 1:1 mapping, we don't care about the port
              if (!(d0->ea_bits_len == 0 && d0->rules))
                {
                  error0 = MAP_ERROR_ICMP;
                  goto err0;
                }
            }

          if (icmp6_to_icmp
              (p0, ip6_to_ip4_set_icmp_cb, &ctx0,
               ip6_to_ip4_set_inner_icmp_cb, &ctx0))
            {
              error0 = MAP_ERROR_ICMP;
              goto err0;
            }

          if (vnet_buffer (p0)->map_t.mtu < p0->current_length)
            {
              // Send to fragmentation node if necessary
              vnet_buffer (p0)->ip_frag.mtu = vnet_buffer (p0)->map_t.mtu;
              vnet_buffer (p0)->ip_frag.next_index = IP4_FRAG_NEXT_IP4_LOOKUP;
              next0 = IP6_MAPT_ICMP_NEXT_IP4_FRAG;
            }
        err0:
          if (PREDICT_TRUE (error0 == MAP_ERROR_NONE))
            {
              vlib_increment_combined_counter (cm + MAP_DOMAIN_COUNTER_RX,
                                               thread_index,
                                               vnet_buffer (p0)->
                                               map_t.map_domain_index, 1,
                                               len0);
            }
          else
            {
              next0 = IP6_MAPT_ICMP_NEXT_DROP;
            }

          p0->error = error_node->errors[error0];
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next, pi0,
                                           next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  return frame->n_vectors;
}

/*
 * Translate IPv6 fragmented packet to IPv4.
 */
always_inline int
map_ip6_to_ip4_fragmented (vlib_buffer_t * p)
{
  ip6_header_t *ip6;
  ip6_frag_hdr_t *frag;
  ip4_header_t *ip4;
  u16 frag_id;
  u8 frag_more;
  u16 frag_offset;
  u8 l4_protocol;
  u16 l4_offset;

  ip6 = vlib_buffer_get_current (p);

  if (ip6_parse
      (ip6, p->current_length, &l4_protocol, &l4_offset, &frag_offset))
    return -1;

  frag = (ip6_frag_hdr_t *) u8_ptr_add (ip6, frag_offset);
  ip4 = (ip4_header_t *) u8_ptr_add (ip6, l4_offset - sizeof (*ip4));
  vlib_buffer_advance (p, l4_offset - sizeof (*ip4));

  frag_id = frag_id_6to4 (frag->identification);
  frag_more = ip6_frag_hdr_more (frag);
  frag_offset = ip6_frag_hdr_offset (frag);

  ip4->dst_address.as_u32 = vnet_buffer (p)->map_t.v6.daddr;
  ip4->src_address.as_u32 = vnet_buffer (p)->map_t.v6.saddr;

  ip4->ip_version_and_header_length =
    IP4_VERSION_AND_HEADER_LENGTH_NO_OPTIONS;
  ip4->tos = ip6_translate_tos (ip6);
  ip4->length =
    u16_net_add (ip6->payload_length,
                 sizeof (*ip4) - l4_offset + sizeof (*ip6));
  ip4->fragment_id = frag_id;
  ip4->flags_and_fragment_offset =
    clib_host_to_net_u16 (frag_offset |
                          (frag_more ? IP4_HEADER_FLAG_MORE_FRAGMENTS : 0));
  ip4->ttl = ip6->hop_limit;
  ip4->protocol =
    (l4_protocol == IP_PROTOCOL_ICMP6) ? IP_PROTOCOL_ICMP : l4_protocol;
  ip4->checksum = ip4_header_checksum (ip4);

  return 0;
}

static uword
ip6_map_t_fragmented (vlib_main_t * vm,
                      vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;
  vlib_node_runtime_t *error_node =
    vlib_node_get_runtime (vm, ip6_map_t_fragmented_node.index);

  while (n_left_from > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 pi0;
          vlib_buffer_t *p0;
          u32 next0;

          pi0 = to_next[0] = from[0];
          from += 1;
          n_left_from -= 1;
          to_next += 1;
          n_left_to_next -= 1;

          next0 = IP6_MAPT_TCP_UDP_NEXT_IP4_LOOKUP;
          p0 = vlib_get_buffer (vm, pi0);

          if (map_ip6_to_ip4_fragmented (p0))
            {
              p0->error = error_node->errors[MAP_ERROR_FRAGMENT_DROPPED];
              next0 = IP6_MAPT_FRAGMENTED_NEXT_DROP;
            }
          else
            {
              if (vnet_buffer (p0)->map_t.mtu < p0->current_length)
                {
                  // Send to fragmentation node if necessary
                  vnet_buffer (p0)->ip_frag.mtu = vnet_buffer (p0)->map_t.mtu;
                  vnet_buffer (p0)->ip_frag.next_index =
                    IP4_FRAG_NEXT_IP4_LOOKUP;
                  next0 = IP6_MAPT_FRAGMENTED_NEXT_IP4_FRAG;
                }
            }

          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next, pi0,
                                           next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  return frame->n_vectors;
}

/*
 * Translate IPv6 UDP/TCP packet to IPv4.
 */
always_inline int
map_ip6_to_ip4_tcp_udp (vlib_buffer_t * p, bool udp_checksum)
{
  map_main_t *mm = &map_main;
  ip6_header_t *ip6;
  u16 *checksum;
  ip_csum_t csum = 0;
  ip4_header_t *ip4;
  u16 fragment_id;
  u16 flags;
  u16 frag_offset;
  u8 l4_protocol;
  u16 l4_offset;
  ip6_address_t old_src, old_dst;

  ip6 = vlib_buffer_get_current (p);

  if (ip6_parse
      (ip6, p->current_length, &l4_protocol, &l4_offset, &frag_offset))
    return -1;

  if (l4_protocol == IP_PROTOCOL_TCP)
    {
      tcp_header_t *tcp = ip6_next_header (ip6);
      if (mm->tcp_mss > 0)
        {
          csum = tcp->checksum;
          map_mss_clamping (tcp, &csum, mm->tcp_mss);
          tcp->checksum = ip_csum_fold (csum);
        }
      checksum = &tcp->checksum;
    }
  else
    {
      udp_header_t *udp = ip6_next_header (ip6);
      checksum = &udp->checksum;
    }

  old_src.as_u64[0] = ip6->src_address.as_u64[0];
  old_src.as_u64[1] = ip6->src_address.as_u64[1];
  old_dst.as_u64[0] = ip6->dst_address.as_u64[0];
  old_dst.as_u64[1] = ip6->dst_address.as_u64[1];

  ip4 = (ip4_header_t *) u8_ptr_add (ip6, l4_offset - sizeof (*ip4));

  vlib_buffer_advance (p, l4_offset - sizeof (*ip4));

  if (PREDICT_FALSE (frag_offset))
    {
      // Only the first fragment
      ip6_frag_hdr_t *hdr = (ip6_frag_hdr_t *) u8_ptr_add (ip6, frag_offset);
      fragment_id = frag_id_6to4 (hdr->identification);
      flags = clib_host_to_net_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
    }
  else
    {
      fragment_id = 0;
      flags = 0;
    }

  ip4->dst_address.as_u32 = vnet_buffer (p)->map_t.v6.daddr;
  ip4->src_address.as_u32 = vnet_buffer (p)->map_t.v6.saddr;

  ip4->ip_version_and_header_length =
    IP4_VERSION_AND_HEADER_LENGTH_NO_OPTIONS;
  ip4->tos = ip6_translate_tos (ip6);
  ip4->length =
    u16_net_add (ip6->payload_length,
                 sizeof (*ip4) + sizeof (*ip6) - l4_offset);
  ip4->fragment_id = fragment_id;
  ip4->flags_and_fragment_offset = flags;
  ip4->ttl = ip6->hop_limit;
  ip4->protocol = l4_protocol;
  ip4->checksum = ip4_header_checksum (ip4);

  // UDP checksum is optional over IPv4
  if (!udp_checksum && l4_protocol == IP_PROTOCOL_UDP)
    {
      *checksum = 0;
    }
  else
    {
      csum = ip_csum_sub_even (*checksum, old_src.as_u64[0]);
      csum = ip_csum_sub_even (csum, old_src.as_u64[1]);
      csum = ip_csum_sub_even (csum, old_dst.as_u64[0]);
      csum = ip_csum_sub_even (csum, old_dst.as_u64[1]);
      csum = ip_csum_add_even (csum, ip4->dst_address.as_u32);
      csum = ip_csum_add_even (csum, ip4->src_address.as_u32);
      *checksum = ip_csum_fold (csum);
    }

  return 0;
}

static uword
ip6_map_t_tcp_udp (vlib_main_t * vm,
                   vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
  vlib_node_runtime_t *error_node =
    vlib_node_get_runtime (vm, ip6_map_t_tcp_udp_node.index);

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;
  while (n_left_from > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 pi0;
          vlib_buffer_t *p0;
          ip6_mapt_tcp_udp_next_t next0;

          pi0 = to_next[0] = from[0];
          from += 1;
          n_left_from -= 1;
          to_next += 1;
          n_left_to_next -= 1;
          next0 = IP6_MAPT_TCP_UDP_NEXT_IP4_LOOKUP;

          p0 = vlib_get_buffer (vm, pi0);

          if (map_ip6_to_ip4_tcp_udp (p0, true))
            {
              p0->error = error_node->errors[MAP_ERROR_UNKNOWN];
              next0 = IP6_MAPT_TCP_UDP_NEXT_DROP;
            }
          else
            {
              if (vnet_buffer (p0)->map_t.mtu < p0->current_length)
                {
                  // Send to fragmentation node if necessary
                  vnet_buffer (p0)->ip_frag.mtu = vnet_buffer (p0)->map_t.mtu;
                  vnet_buffer (p0)->ip_frag.next_index =
                    IP4_FRAG_NEXT_IP4_LOOKUP;
                  next0 = IP6_MAPT_TCP_UDP_NEXT_IP4_FRAG;
                }
            }

          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next, pi0,
                                           next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  return frame->n_vectors;
}

static uword
ip6_map_t (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
  vlib_node_runtime_t *error_node =
    vlib_node_get_runtime (vm, ip6_map_t_node.index);
  vlib_combined_counter_main_t *cm = map_main.domain_counters;
  u32 thread_index = vm->thread_index;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;
  while (n_left_from > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 pi0;
          vlib_buffer_t *p0;
          ip6_header_t *ip60;
          u8 error0;
          u32 l4_len0;
          i32 map_port0;
          map_domain_t *d0;
          ip6_frag_hdr_t *frag0;
          ip6_mapt_next_t next0 = 0;
          u32 saddr;

          pi0 = to_next[0] = from[0];
          from += 1;
          n_left_from -= 1;
          to_next += 1;
          n_left_to_next -= 1;
          error0 = MAP_ERROR_NONE;

          p0 = vlib_get_buffer (vm, pi0);
          ip60 = vlib_buffer_get_current (p0);

          d0 =
            ip6_map_get_domain (&ip60->dst_address,
                                &vnet_buffer (p0)->map_t.map_domain_index,
                                &error0);
          if (!d0)
            {                   /* Guess it wasn't for us */
              vnet_feature_next (&next0, p0);
              goto exit;
            }

          saddr = map_get_ip4 (&ip60->src_address, d0->ip6_src_len);
          vnet_buffer (p0)->map_t.v6.saddr = saddr;
          vnet_buffer (p0)->map_t.v6.daddr =
            ip6_map_t_embedded_address (d0, &ip60->dst_address);
          vnet_buffer (p0)->map_t.mtu = d0->mtu ? d0->mtu : ~0;

          if (PREDICT_FALSE
              (ip6_parse (ip60, p0->current_length,
                          &(vnet_buffer (p0)->map_t.v6.l4_protocol),
                          &(vnet_buffer (p0)->map_t.v6.l4_offset),
                          &(vnet_buffer (p0)->map_t.v6.frag_offset))))
            {
              error0 =
                error0 == MAP_ERROR_NONE ? MAP_ERROR_MALFORMED : error0;
            }

          map_port0 = -1;
          l4_len0 =
            (u32) clib_net_to_host_u16 (ip60->payload_length) +
            sizeof (*ip60) - vnet_buffer (p0)->map_t.v6.l4_offset;
          frag0 =
            (ip6_frag_hdr_t *) u8_ptr_add (ip60,
                                           vnet_buffer (p0)->map_t.v6.
                                           frag_offset);

          if (PREDICT_FALSE
              (vnet_buffer (p0)->map_t.v6.frag_offset
               && ip6_frag_hdr_offset (frag0)))
            {
              map_port0 = ip6_map_fragment_get (ip60, frag0, d0);
              if (map_port0 == -1)
                error0 =
                  error0 ==
                  MAP_ERROR_NONE ? MAP_ERROR_FRAGMENT_MEMORY : error0;
              else
                next0 = IP6_MAPT_NEXT_MAPT_FRAGMENTED;
            }
          else
            if (PREDICT_TRUE
                (vnet_buffer (p0)->map_t.v6.l4_protocol == IP_PROTOCOL_TCP))
            {
              error0 =
                l4_len0 <
                sizeof (tcp_header_t) ? MAP_ERROR_MALFORMED : error0;
              vnet_buffer (p0)->map_t.checksum_offset =
                vnet_buffer (p0)->map_t.v6.l4_offset + 16;
              next0 = IP6_MAPT_NEXT_MAPT_TCP_UDP;
              map_port0 =
                (i32) *
                ((u16 *)
                 u8_ptr_add (ip60, vnet_buffer (p0)->map_t.v6.l4_offset));
            }
          else
            if (PREDICT_TRUE
                (vnet_buffer (p0)->map_t.v6.l4_protocol == IP_PROTOCOL_UDP))
            {
              error0 =
                l4_len0 <
                sizeof (udp_header_t) ? MAP_ERROR_MALFORMED : error0;
              vnet_buffer (p0)->map_t.checksum_offset =
                vnet_buffer (p0)->map_t.v6.l4_offset + 6;
              next0 = IP6_MAPT_NEXT_MAPT_TCP_UDP;
              map_port0 =
                (i32) *
                ((u16 *)
                 u8_ptr_add (ip60, vnet_buffer (p0)->map_t.v6.l4_offset));
            }
          else if (vnet_buffer (p0)->map_t.v6.l4_protocol ==
                   IP_PROTOCOL_ICMP6)
            {
              error0 =
                l4_len0 <
                sizeof (icmp46_header_t) ? MAP_ERROR_MALFORMED : error0;
              next0 = IP6_MAPT_NEXT_MAPT_ICMP;
              if (((icmp46_header_t *)
                   u8_ptr_add (ip60,
                               vnet_buffer (p0)->map_t.v6.l4_offset))->code ==
                  ICMP6_echo_reply
                  || ((icmp46_header_t *)
                      u8_ptr_add (ip60,
                                  vnet_buffer (p0)->map_t.v6.l4_offset))->
                  code == ICMP6_echo_request)
                map_port0 =
                  (i32) *
                  ((u16 *)
                   u8_ptr_add (ip60,
                               vnet_buffer (p0)->map_t.v6.l4_offset + 6));
            }
          else
            {
              // TODO: In case of 1:1 mapping, it might be possible to
              // do something with those packets.
              error0 = MAP_ERROR_BAD_PROTOCOL;
            }

          if (PREDICT_FALSE (map_port0 != -1) &&
              (ip60->src_address.as_u64[0] !=
               map_get_pfx_net (d0, vnet_buffer (p0)->map_t.v6.saddr,
                                map_port0)
               || ip60->src_address.as_u64[1] != map_get_sfx_net (d0,
                                                                  vnet_buffer
                                                                  (p0)->map_t.
                                                                  v6.saddr,
                                                                  map_port0)))
            {
              // Security check when map_port0 is not zero (non-first
              // fragment, UDP or TCP)
              error0 =
                error0 == MAP_ERROR_NONE ? MAP_ERROR_SEC_CHECK : error0;
            }

          // Fragmented first packet needs to be cached for following packets
          if (PREDICT_FALSE
              (vnet_buffer (p0)->map_t.v6.frag_offset
               && !ip6_frag_hdr_offset ((ip6_frag_hdr_t *)
                                        u8_ptr_add (ip60,
                                                    vnet_buffer (p0)->map_t.
                                                    v6.frag_offset)))
              && (map_port0 != -1) && (d0->ea_bits_len != 0 || !d0->rules)
              && (error0 == MAP_ERROR_NONE))
            {
              ip6_map_fragment_cache (ip60,
                                      (ip6_frag_hdr_t *) u8_ptr_add (ip60,
                                                                     vnet_buffer
                                                                     (p0)->
                                                                     map_t.v6.
                                                                     frag_offset),
                                      d0, map_port0);
            }

          if (PREDICT_TRUE
              (error0 == MAP_ERROR_NONE && next0 != IP6_MAPT_NEXT_MAPT_ICMP))
            {
              vlib_increment_combined_counter (cm + MAP_DOMAIN_COUNTER_RX,
                                               thread_index,
                                               vnet_buffer (p0)->map_t.
                                               map_domain_index, 1,
                                               clib_net_to_host_u16 (ip60->
                                                                     payload_length));
            }

          next0 = (error0 != MAP_ERROR_NONE) ? IP6_MAPT_NEXT_DROP : next0;
          p0->error = error_node->errors[error0];
        exit:
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                           to_next, n_left_to_next, pi0,
                                           next0);
        }
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  return frame->n_vectors;
}

static char *map_t_error_strings[] = {
#define _(sym, string) string,
  foreach_map_error
#undef _
};

/* *INDENT-OFF* */
VLIB_REGISTER_NODE(ip6_map_t_fragmented_node) = {
  .function = ip6_map_t_fragmented,
  .name = "ip6-map-t-fragmented",
  .vector_size = sizeof (u32),
  .format_trace = format_map_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = MAP_N_ERROR,
  .error_strings = map_t_error_strings,

  .n_next_nodes = IP6_MAPT_FRAGMENTED_N_NEXT,
  .next_nodes =
  {
    [IP6_MAPT_FRAGMENTED_NEXT_IP4_LOOKUP] = "ip4-lookup",
    [IP6_MAPT_FRAGMENTED_NEXT_IP4_FRAG] = IP4_FRAG_NODE_NAME,
    [IP6_MAPT_FRAGMENTED_NEXT_DROP] = "error-drop",
  },
};
/* *INDENT-ON* */

/* *INDENT-OFF* */
VLIB_REGISTER_NODE(ip6_map_t_icmp_node) = {
  .function = ip6_map_t_icmp,
  .name = "ip6-map-t-icmp",
  .vector_size = sizeof (u32),
  .format_trace = format_map_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = MAP_N_ERROR,
  .error_strings = map_t_error_strings,

  .n_next_nodes = IP6_MAPT_ICMP_N_NEXT,
  .next_nodes =
  {
    [IP6_MAPT_ICMP_NEXT_IP4_LOOKUP] = "ip4-lookup",
    [IP6_MAPT_ICMP_NEXT_IP4_FRAG] = IP4_FRAG_NODE_NAME,
    [IP6_MAPT_ICMP_NEXT_DROP] = "error-drop",
  },
};
/* *INDENT-ON* */

/* *INDENT-OFF* */
VLIB_REGISTER_NODE(ip6_map_t_tcp_udp_node) = {
  .function = ip6_map_t_tcp_udp,
  .name = "ip6-map-t-tcp-udp",
  .vector_size = sizeof (u32),
  .format_trace = format_map_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = MAP_N_ERROR,
  .error_strings = map_t_error_strings,

  .n_next_nodes = IP6_MAPT_TCP_UDP_N_NEXT,
  .next_nodes =
  {
    [IP6_MAPT_TCP_UDP_NEXT_IP4_LOOKUP] = "ip4-lookup",
    [IP6_MAPT_TCP_UDP_NEXT_IP4_FRAG] = IP4_FRAG_NODE_NAME,
    [IP6_MAPT_TCP_UDP_NEXT_DROP] = "error-drop",
  },
};
/* *INDENT-ON* */

/* *INDENT-OFF* */
VNET_FEATURE_INIT(ip4_map_t_feature, static) = {
  .arc_name = "ip6-unicast",
  .node_name = "ip6-map-t",
  .runs_before = VNET_FEATURES("ip6-flow-classify"),
};

VLIB_REGISTER_NODE(ip6_map_t_node) = {
  .function = ip6_map_t,
  .name = "ip6-map-t",
  .vector_size = sizeof(u32),
  .format_trace = format_map_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_errors = MAP_N_ERROR,
  .error_strings = map_t_error_strings,

  .n_next_nodes = IP6_MAPT_N_NEXT,
  .next_nodes =
  {
    [IP6_MAPT_NEXT_MAPT_TCP_UDP] = "ip6-map-t-tcp-udp",
    [IP6_MAPT_NEXT_MAPT_ICMP] = "ip6-map-t-icmp",
    [IP6_MAPT_NEXT_MAPT_FRAGMENTED] = "ip6-map-t-fragmented",
    [IP6_MAPT_NEXT_DROP] = "error-drop",
  },
};
/* *INDENT-ON* */

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