src/plugins/srv6-ad/node.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.
 */
/*
  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus

  Permission is hereby granted, free of charge, to any person obtaining
  a copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, sublicense, and/or sell copies of the Software, and to
  permit persons to whom the Software is furnished to do so, subject to
  the following conditions:

  The above copyright notice and this permission notice shall be
  included in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#ifndef included_error_bootstrap_h
#define included_error_bootstrap_h

/* Bootstrap include so that #include <vppinfra/mem.h> can include e.g.
   <vppinfra/mheap.h> which depends on <vppinfra/vec.h>. */

#include <vppinfra/clib.h>	/* for uword */

enum
{
  CLIB_ERROR_FATAL = 1 << 0,
  CLIB_ERROR_ABORT = 1 << 1,
  CLIB_ERROR_WARNING = 1 << 2,
  CLIB_ERROR_ERRNO_VALID = 1 << 16,
  CLIB_ERROR_NO_RATE_LIMIT = 1 << 17,
};

/* Current function name.  Need (char *) cast to silence gcc4 pointer signedness warning. */
#define clib_error_function ((char *) __FUNCTION__)

#ifndef CLIB_ASSERT_ENABLE
#define CLIB_ASSERT_ENABLE (CLIB_DEBUG > 0)
#endif

/* Low level error reporting function.
   Code specifies whether to call exit, abort or nothing at
   all (for non-fatal warnings). */
extern void _clib_error (int code,
			 char *function_name,
			 uword line_number, char *format, ...);

#define ASSERT(truth)					\
do {							\
  if (CLIB_ASSERT_ENABLE && ! (truth))			\
    {							\
      _clib_error (CLIB_ERROR_ABORT, 0, 0,		\
		   "%s:%d (%s) assertion `%s' fails",	\
		   __FILE__,				\
		   (uword) __LINE__,			\
		   clib_error_function,			\
		   # truth);				\
    }							\
} while (0)

/*
 * This version always generates code, and has a Coverity-specific
 * version to stop Coverity complaining about
 * ALWAYS_ASSERT(p != 0); p->member...
 */

#ifndef __COVERITY__
#define ALWAYS_ASSERT(truth)				\
do {							\
  if (PREDICT_FALSE(!(truth)))                          \
    {							\
      _clib_error (CLIB_ERROR_ABORT, 0, 0,		\
		   "%s:%d (%s) assertion `%s' fails",	\
		   __FILE__,				\
		   (uword) __LINE__,			\
		   clib_error_function,			\
		   # truth);				\
    }							\
} while (0)
#else /* __COVERITY__ */
#define ALWAYS_ASSERT(truth)                    \
do {                                            \
  if (PREDICT_FALSE(!(truth)))                  \
    {                                           \
      abort();                                  \
    }                                           \
} while (0)
#endif /* __COVERITY */

#define STATIC_ASSERT(truth,...) _Static_assert(truth, __VA_ARGS__)

#define STATIC_ASSERT_SIZEOF(d, s) \
  STATIC_ASSERT (sizeof (d) == s, "Size of " #d " must be " # s " bytes")

#define STATIC_ASSERT_SIZEOF_ELT(d, e, s) \
  STATIC_ASSERT (sizeof (((d *)0)->e) == s, "Size of " #d "." #e " must be " # s " bytes")

#define STATIC_ASSERT_OFFSET_OF(s, e, o) \
  STATIC_ASSERT (STRUCT_OFFSET_OF(s,e) == o, "Offset of " #s "." #e " must be " # o)

#define STATIC_ASSERT_FITS_IN(s, e, o) \
  STATIC_ASSERT (STRUCT_OFFSET_OF(s,e) <= (o - sizeof(((s *)0)->e)), \
  #s "." #e " does not fit into " # o " bytes")

/* Assert without allocating memory. */
#define ASSERT_AND_PANIC(truth)			\
do {						\
  if (CLIB_ASSERT_ENABLE && ! (truth))		\
    os_panic ();				\
} while (0)

#endif /* included_error_bootstrap_h */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */
/*
 * node.c
 *
 * 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 <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vppinfra/error.h>
#include <srv6-ad/ad.h>


/******************************* Packet tracing *******************************/

typedef struct
{
  u32 localsid_index;
} srv6_ad_localsid_trace_t;

typedef struct
{
  u8 error;
  ip6_address_t src, dst;
} srv6_ad_rewrite_trace_t;

static u8 *
format_srv6_ad_localsid_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 *);
  srv6_ad_localsid_trace_t *t = va_arg (*args, srv6_ad_localsid_trace_t *);

  return format (s, "SRv6-AD-localsid: localsid_index %d", t->localsid_index);
}

static u8 *
format_srv6_ad_rewrite_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 *);
  srv6_ad_rewrite_trace_t *t = va_arg (*args, srv6_ad_rewrite_trace_t *);

  if (PREDICT_FALSE (t->error != 0))
    {
      return format (s, "SRv6-AD-rewrite: cache is empty");
    }

  return format (s, "SRv6-AD-rewrite: src %U dst %U",
		 format_ip6_address, &t->src, format_ip6_address, &t->dst);
}


/***************************** Nodes registration *****************************/

vlib_node_registration_t srv6_ad4_rewrite_node;
vlib_node_registration_t srv6_ad6_rewrite_node;


/****************************** Packet counters *******************************/

#define foreach_srv6_ad_rewrite_counter \
_(PROCESSED, "srv6-ad rewritten packets") \
_(NO_RW, "(Error) No header for rewriting.")

typedef enum
{
#define _(sym,str) SRV6_AD_REWRITE_COUNTER_##sym,
  foreach_srv6_ad_rewrite_counter
#undef _
    SRV6_AD_REWRITE_N_COUNTERS,
} srv6_ad_rewrite_counters;

static char *srv6_ad_rewrite_counter_strings[] = {
#define _(sym,string) string,
  foreach_srv6_ad_rewrite_counter
#undef _
};


/********************************* Next nodes *********************************/

typedef enum
{
  SRV6_AD_LOCALSID_NEXT_ERROR,
  SRV6_AD_LOCALSID_NEXT_REWRITE4,
  SRV6_AD_LOCALSID_NEXT_REWRITE6,
  SRV6_AD_LOCALSID_NEXT_INTERFACE,
  SRV6_AD_LOCALSID_N_NEXT,
} srv6_ad_localsid_next_t;

typedef enum
{
  SRV6_AD_REWRITE_NEXT_ERROR,
  SRV6_AD_REWRITE_NEXT_LOOKUP,
  SRV6_AD_REWRITE_N_NEXT,
} srv6_ad_rewrite_next_t;


/******************************* Local SID node *******************************/

/**
 * @brief Function doing SRH processing for AD behavior
 */
static_always_inline void
end_ad_processing (vlib_buffer_t * b0,
		   ip6_header_t * ip0,
		   ip6_sr_header_t * sr0,
		   ip6_sr_localsid_t * ls0, u32 * next0)
{
  ip6_address_t *new_dst0;
  u16 total_size;
  ip6_ext_header_t *next_ext_header;
  u8 next_hdr;
  srv6_ad_localsid_t *ls0_mem;

  if (PREDICT_FALSE (ip0->protocol != IP_PROTOCOL_IPV6_ROUTE ||
		     sr0->type != ROUTING_HEADER_TYPE_SR))
    {
      return;
    }

  if (PREDICT_FALSE (sr0->segments_left == 0))
    {
      return;
    }

  /* Decrement Segments Left and update Destination Address */
  sr0->segments_left -= 1;
  new_dst0 = (ip6_address_t *) (sr0->segments) + sr0->segments_left;
  ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
  ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];

  /* Compute the total size of the IPv6 header and extensions */
  total_size = sizeof (ip6_header_t);
  next_ext_header = (ip6_ext_header_t *) (ip0 + 1);
  next_hdr = ip0->protocol;

  while (ip6_ext_hdr (next_hdr))
    {
      total_size += ip6_ext_header_len (next_ext_header);
      next_hdr = next_ext_header->next_hdr;
      next_ext_header = ip6_ext_next_header (next_ext_header);
    }

  /* Make sure next header is valid */
  if (PREDICT_FALSE (next_hdr != IP_PROTOCOL_IPV6 &&
		     next_hdr != IP_PROTOCOL_IP_IN_IP &&
		     next_hdr != IP_PROTOCOL_IP6_ETHERNET))
    {
      return;
    }

  /* Retrieve SID memory */
  ls0_mem = ls0->plugin_mem;

  /* Cache IP header and extensions */
  if (PREDICT_FALSE (total_size > ls0_mem->rw_len))
    {
      vec_validate (ls0_mem->rewrite, total_size - 1);
    }
  clib_memcpy_fast (ls0_mem->rewrite, ip0, total_size);
  ls0_mem->rw_len = total_size;

  /* Remove IP header and extensions */
  vlib_buffer_advance (b0, total_size);

  if (next_hdr == IP_PROTOCOL_IP6_ETHERNET)
    {
      /* Set output interface */
      vnet_buffer (b0)->sw_if_index[VLIB_TX] = ls0_mem->sw_if_index_out;

      /* Set next node to interface-output */
      *next0 = SRV6_AD_LOCALSID_NEXT_INTERFACE;
    }
  else
    {
      /* Set Xconnect adjacency to VNF */
      vnet_buffer (b0)->ip.adj_index[VLIB_TX] = ls0_mem->nh_adj;

      /* Set next node to ip-rewrite */
      *next0 = (next_hdr == IP_PROTOCOL_IPV6) ?
	SRV6_AD_LOCALSID_NEXT_REWRITE6 : SRV6_AD_LOCALSID_NEXT_REWRITE4;
    }
}

/**
 * @brief SRv6 AD Localsid graph node
 */
static uword
srv6_ad_localsid_fn (vlib_main_t * vm,
		     vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  ip6_sr_main_t *sm = &sr_main;
  u32 n_left_from, next_index, *from, *to_next;
  u32 cnt_packets = 0;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      /* TODO: Dual/quad loop */

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  ip6_header_t *ip0 = 0;
	  ip6_sr_header_t *sr0;
	  ip6_sr_localsid_t *ls0;
	  u32 next0 = SRV6_AD_LOCALSID_NEXT_ERROR;

	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  ip0 = vlib_buffer_get_current (b0);
	  sr0 = (ip6_sr_header_t *) (ip0 + 1);

	  /* Lookup the SR End behavior based on IP DA (adj) */
	  ls0 = pool_elt_at_index (sm->localsids,
				   vnet_buffer (b0)->ip.adj_index[VLIB_TX]);

	  /* SRH processing */
	  end_ad_processing (b0, ip0, sr0, ls0, &next0);

	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_ad_localsid_trace_t *tr =
		vlib_add_trace (vm, node, b0, sizeof *tr);
	      tr->localsid_index = ls0 - sm->localsids;
	    }

	  /* This increments the SRv6 per LocalSID counters. */
	  vlib_increment_combined_counter (((next0 ==
					     SRV6_AD_LOCALSID_NEXT_ERROR) ?
					    &(sm->sr_ls_invalid_counters) :
					    &(sm->sr_ls_valid_counters)),
					   vm->thread_index,
					   ls0 - sm->localsids, 1,
					   vlib_buffer_length_in_chain (vm,
									b0));

	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi0, next0);

	  cnt_packets++;
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (srv6_ad_localsid_node) = {
  .function = srv6_ad_localsid_fn,
  .name = "srv6-ad-localsid",
  .vector_size = sizeof (u32),
  .format_trace = format_srv6_ad_localsid_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_next_nodes = SRV6_AD_LOCALSID_N_NEXT,
  .next_nodes = {
    [SRV6_AD_LOCALSID_NEXT_REWRITE4] = "ip4-rewrite",
    [SRV6_AD_LOCALSID_NEXT_REWRITE6] = "ip6-rewrite",
    [SRV6_AD_LOCALSID_NEXT_INTERFACE] = "interface-output",
    [SRV6_AD_LOCALSID_NEXT_ERROR] = "error-drop",
  },
};
/* *INDENT-ON* */


/******************************* Rewriting node *******************************/

/**
 * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 */
static uword
srv6_ad2_rewrite_fn (vlib_main_t * vm,
		     vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  ip6_sr_main_t *srm = &sr_main;
  srv6_ad_main_t *sm = &srv6_ad_main;
  u32 n_left_from, next_index, *from, *to_next;
  u32 cnt_packets = 0;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      /* TODO: Dual/quad loop */

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  ethernet_header_t *en0;
	  ip6_header_t *ip0 = 0;
	  ip6_sr_localsid_t *ls0;
	  srv6_ad_localsid_t *ls0_mem;
	  u32 next0 = SRV6_AD_REWRITE_NEXT_LOOKUP;

	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  en0 = vlib_buffer_get_current (b0);
	  ls0 = pool_elt_at_index (srm->localsids,
				   sm->sw_iface_localsid2[vnet_buffer
							  (b0)->sw_if_index
							  [VLIB_RX]]);
	  ls0_mem = ls0->plugin_mem;

	  if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
	    {
	      next0 = SRV6_AD_REWRITE_NEXT_ERROR;
	      b0->error = node->errors[SRV6_AD_REWRITE_COUNTER_NO_RW];
	    }
	  else
	    {
	      ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
		      (ls0_mem->rw_len + b0->current_data));

	      clib_memcpy_fast (((u8 *) en0) - ls0_mem->rw_len,
				ls0_mem->rewrite, ls0_mem->rw_len);
	      vlib_buffer_advance (b0, -(word) ls0_mem->rw_len);

	      ip0 = vlib_buffer_get_current (b0);

	      ip0->payload_length =
		clib_host_to_net_u16 (b0->current_length -
				      sizeof (ip6_header_t));
	    }

	  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
	      PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_ad_rewrite_trace_t *tr =
		vlib_add_trace (vm, node, b0, sizeof *tr);
	      tr->error = 0;

	      if (next0 == SRV6_AD_REWRITE_NEXT_ERROR)
		{
		  tr->error = 1;
		}
	      else
		{
		  clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
				    sizeof tr->src.as_u8);
		  clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
				    sizeof tr->dst.as_u8);
		}
	    }

	  /* Increment per-SID AD rewrite counters */
	  vlib_increment_combined_counter (((next0 ==
					     SRV6_AD_LOCALSID_NEXT_ERROR) ?
					    &(sm->invalid_counters) :
					    &(sm->valid_counters)),
					   vm->thread_index, ls0_mem->index,
					   1, vlib_buffer_length_in_chain (vm,
									   b0));

	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi0, next0);

	  cnt_packets++;
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  /* Update counters */
  vlib_node_increment_counter (vm, srv6_ad4_rewrite_node.index,
			       SRV6_AD_REWRITE_COUNTER_PROCESSED,
			       cnt_packets);

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (srv6_ad2_rewrite_node) = {
  .function = srv6_ad2_rewrite_fn,
  .name = "srv6-ad2-rewrite",
  .vector_size = sizeof (u32),
  .format_trace = format_srv6_ad_rewrite_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = SRV6_AD_REWRITE_N_COUNTERS,
  .error_strings = srv6_ad_rewrite_counter_strings,
  .n_next_nodes = SRV6_AD_REWRITE_N_NEXT,
  .next_nodes = {
    [SRV6_AD_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
    [SRV6_AD_REWRITE_NEXT_ERROR] = "error-drop",
  },
};
/* *INDENT-ON* */


/**
 * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 */
static uword
srv6_ad4_rewrite_fn (vlib_main_t * vm,
		     vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  ip6_sr_main_t *srm = &sr_main;
  srv6_ad_main_t *sm = &srv6_ad_main;
  u32 n_left_from, next_index, *from, *to_next;
  u32 cnt_packets = 0;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      /* TODO: Dual/quad loop */

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  ip4_header_t *ip0_encap = 0;
	  ip6_header_t *ip0 = 0;
	  ip6_sr_localsid_t *ls0;
	  srv6_ad_localsid_t *ls0_mem;
	  u32 next0 = SRV6_AD_REWRITE_NEXT_LOOKUP;
	  u16 new_l0 = 0;

	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  ip0_encap = vlib_buffer_get_current (b0);
	  ls0 = pool_elt_at_index (srm->localsids,
				   sm->sw_iface_localsid4[vnet_buffer
							  (b0)->sw_if_index
							  [VLIB_RX]]);
	  ls0_mem = ls0->plugin_mem;

	  if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
	    {
	      next0 = SRV6_AD_REWRITE_NEXT_ERROR;
	      b0->error = node->errors[SRV6_AD_REWRITE_COUNTER_NO_RW];
	    }
	  else
	    {
	      ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
		      (ls0_mem->rw_len + b0->current_data));

	      clib_memcpy_fast (((u8 *) ip0_encap) - ls0_mem->rw_len,
				ls0_mem->rewrite, ls0_mem->rw_len);
	      vlib_buffer_advance (b0, -(word) ls0_mem->rw_len);

	      ip0 = vlib_buffer_get_current (b0);

	      /* Update inner IPv4 TTL and checksum */
	      u32 checksum0;
	      ip0_encap->ttl -= 1;
	      checksum0 = ip0_encap->checksum + clib_host_to_net_u16 (0x0100);
	      checksum0 += checksum0 >= 0xffff;
	      ip0_encap->checksum = checksum0;

	      /* Update outer IPv6 length (in case it has changed) */
	      new_l0 = ls0_mem->rw_len - sizeof (ip6_header_t) +
		clib_net_to_host_u16 (ip0_encap->length);
	      ip0->payload_length = clib_host_to_net_u16 (new_l0);
	    }

	  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
	      PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_ad_rewrite_trace_t *tr =
		vlib_add_trace (vm, node, b0, sizeof *tr);
	      tr->error = 0;

	      if (next0 == SRV6_AD_REWRITE_NEXT_ERROR)
		{
		  tr->error = 1;
		}
	      else
		{
		  clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
				    sizeof tr->src.as_u8);
		  clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
				    sizeof tr->dst.as_u8);
		}
	    }

	  /* Increment per-SID AD rewrite counters */
	  vlib_increment_combined_counter (((next0 ==
					     SRV6_AD_LOCALSID_NEXT_ERROR) ?
					    &(sm->invalid_counters) :
					    &(sm->valid_counters)),
					   vm->thread_index, ls0_mem->index,
					   1, vlib_buffer_length_in_chain (vm,
									   b0));

	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi0, next0);

	  cnt_packets++;
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  /* Update counters */
  vlib_node_increment_counter (vm, srv6_ad4_rewrite_node.index,
			       SRV6_AD_REWRITE_COUNTER_PROCESSED,
			       cnt_packets);

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (srv6_ad4_rewrite_node) = {
  .function = srv6_ad4_rewrite_fn,
  .name = "srv6-ad4-rewrite",
  .vector_size = sizeof (u32),
  .format_trace = format_srv6_ad_rewrite_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = SRV6_AD_REWRITE_N_COUNTERS,
  .error_strings = srv6_ad_rewrite_counter_strings,
  .n_next_nodes = SRV6_AD_REWRITE_N_NEXT,
  .next_nodes = {
      [SRV6_AD_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
      [SRV6_AD_REWRITE_NEXT_ERROR] = "error-drop",
  },
};
/* *INDENT-ON* */


/**
 * @brief Graph node for applying a SR policy into an IPv6 packet. Encapsulation
 */
static uword
srv6_ad6_rewrite_fn (vlib_main_t * vm,
		     vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  ip6_sr_main_t *srm = &sr_main;
  srv6_ad_main_t *sm = &srv6_ad_main;
  u32 n_left_from, next_index, *from, *to_next;
  u32 cnt_packets = 0;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      /* TODO: Dual/quad loop */

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  ip6_header_t *ip0 = 0, *ip0_encap = 0;
	  ip6_sr_localsid_t *ls0;
	  srv6_ad_localsid_t *ls0_mem;
	  u32 next0 = SRV6_AD_REWRITE_NEXT_LOOKUP;
	  u16 new_l0 = 0;

	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  ip0_encap = vlib_buffer_get_current (b0);
	  ls0 = pool_elt_at_index (srm->localsids,
				   sm->sw_iface_localsid6[vnet_buffer
							  (b0)->sw_if_index
							  [VLIB_RX]]);
	  ls0_mem = ls0->plugin_mem;

	  if (PREDICT_FALSE (ls0_mem == NULL || ls0_mem->rewrite == NULL))
	    {
	      next0 = SRV6_AD_REWRITE_NEXT_ERROR;
	      b0->error = node->errors[SRV6_AD_REWRITE_COUNTER_NO_RW];
	    }
	  else
	    {
	      ASSERT (VLIB_BUFFER_PRE_DATA_SIZE >=
		      (ls0_mem->rw_len + b0->current_data));

	      clib_memcpy_fast (((u8 *) ip0_encap) - ls0_mem->rw_len,
				ls0_mem->rewrite, ls0_mem->rw_len);
	      vlib_buffer_advance (b0, -(word) ls0_mem->rw_len);

	      ip0 = vlib_buffer_get_current (b0);

	      /* Update inner IPv6 hop limit */
	      ip0_encap->hop_limit -= 1;

	      /* Update outer IPv6 length (in case it has changed) */
	      new_l0 = ls0_mem->rw_len +
		clib_net_to_host_u16 (ip0_encap->payload_length);
	      ip0->payload_length = clib_host_to_net_u16 (new_l0);
	    }

	  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE) &&
	      PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_ad_rewrite_trace_t *tr =
		vlib_add_trace (vm, node, b0, sizeof *tr);
	      tr->error = 0;

	      if (next0 == SRV6_AD_REWRITE_NEXT_ERROR)
		{
		  tr->error = 1;
		}
	      else
		{
		  clib_memcpy_fast (tr->src.as_u8, ip0->src_address.as_u8,
				    sizeof tr->src.as_u8);
		  clib_memcpy_fast (tr->dst.as_u8, ip0->dst_address.as_u8,
				    sizeof tr->dst.as_u8);
		}
	    }

	  /* Increment per-SID AD rewrite counters */
	  vlib_increment_combined_counter (((next0 ==
					     SRV6_AD_LOCALSID_NEXT_ERROR) ?
					    &(sm->invalid_counters) :
					    &(sm->valid_counters)),
					   vm->thread_index, ls0_mem->index,
					   1, vlib_buffer_length_in_chain (vm,
									   b0));

	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
					   n_left_to_next, bi0, next0);

	  cnt_packets++;
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  /* Update counters */
  vlib_node_increment_counter (vm, srv6_ad6_rewrite_node.index,
			       SRV6_AD_REWRITE_COUNTER_PROCESSED,
			       cnt_packets);

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (srv6_ad6_rewrite_node) = {
  .function = srv6_ad6_rewrite_fn,
  .name = "srv6-ad6-rewrite",
  .vector_size = sizeof (u32),
  .format_trace = format_srv6_ad_rewrite_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = SRV6_AD_REWRITE_N_COUNTERS,
  .error_strings = srv6_ad_rewrite_counter_strings,
  .n_next_nodes = SRV6_AD_REWRITE_N_NEXT,
  .next_nodes = {
      [SRV6_AD_REWRITE_NEXT_LOOKUP] = "ip6-lookup",
      [SRV6_AD_REWRITE_NEXT_ERROR] = "error-drop",
  },
};
/* *INDENT-ON* */

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