/*
 * 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-un/un.h>


/******************************* Packet tracing *******************************/
typedef struct
{
  u32 localsid_index;
} srv6_un_localsid_trace_t;


static u8 *
format_srv6_un_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_un_localsid_trace_t *t = va_arg (*args, srv6_un_localsid_trace_t *);

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

/********************************* Next nodes *********************************/
typedef enum
{
  SRV6_UN_LOCALSID_NEXT_ERROR,
  SRV6_UN_LOCALSID_NEXT_IP6LOOKUP,
  SRV6_UN_LOCALSID_N_NEXT,
} srv6_un_localsid_next_t;

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

/**
 * @brief Graph node for applying SRv6 uN.
 */
static uword
srv6_un_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;

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

  u32 thread_index = vm->thread_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);

      /* Quad - Loop */
      while (n_left_from >= 8 && n_left_to_next >= 4)
	{
	  u32 bi0, bi1, bi2, bi3;
	  vlib_buffer_t *b0, *b1, *b2, *b3;
	  ip6_header_t *ip0, *ip1, *ip2, *ip3;
	  u32 next0, next1, next2, next3;
	  next0 = next1 = next2 = next3 = SRV6_UN_LOCALSID_NEXT_IP6LOOKUP;
	  ip6_sr_localsid_t *ls0, *ls1, *ls2, *ls3;

	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t *p4, *p5, *p6, *p7;

	    p4 = vlib_get_buffer (vm, from[4]);
	    p5 = vlib_get_buffer (vm, from[5]);
	    p6 = vlib_get_buffer (vm, from[6]);
	    p7 = vlib_get_buffer (vm, from[7]);

	    /* Prefetch the buffer header and packet for the N+4 loop iteration */
	    vlib_prefetch_buffer_header (p4, LOAD);
	    vlib_prefetch_buffer_header (p5, LOAD);
	    vlib_prefetch_buffer_header (p6, LOAD);
	    vlib_prefetch_buffer_header (p7, LOAD);

	    CLIB_PREFETCH (p4->data, CLIB_CACHE_LINE_BYTES, STORE);
	    CLIB_PREFETCH (p5->data, CLIB_CACHE_LINE_BYTES, STORE);
	    CLIB_PREFETCH (p6->data, CLIB_CACHE_LINE_BYTES, STORE);
	    CLIB_PREFETCH (p7->data, CLIB_CACHE_LINE_BYTES, STORE);
	  }

	  to_next[0] = bi0 = from[0];
	  to_next[1] = bi1 = from[1];
	  to_next[2] = bi2 = from[2];
	  to_next[3] = bi3 = from[3];
	  from += 4;
	  to_next += 4;
	  n_left_from -= 4;
	  n_left_to_next -= 4;

	  b0 = vlib_get_buffer (vm, bi0);
	  b1 = vlib_get_buffer (vm, bi1);
	  b2 = vlib_get_buffer (vm, bi2);
	  b3 = vlib_get_buffer (vm, bi3);

	  ls0 =
	    pool_elt_at_index (sm->localsids,
			       vnet_buffer (b0)->ip.adj_index[VLIB_TX]);
	  ls1 =
	    pool_elt_at_index (sm->localsids,
			       vnet_buffer (b1)->ip.adj_index[VLIB_TX]);
	  ls2 =
	    pool_elt_at_index (sm->localsids,
			       vnet_buffer (b2)->ip.adj_index[VLIB_TX]);
	  ls3 =
	    pool_elt_at_index (sm->localsids,
			       vnet_buffer (b3)->ip.adj_index[VLIB_TX]);

	  ip0 = vlib_buffer_get_current (b0);
	  ip1 = vlib_buffer_get_current (b1);
	  ip2 = vlib_buffer_get_current (b2);
	  ip3 = vlib_buffer_get_current (b3);

	  /* Set Destination Address to Last Segment (index 0) */
	  ip0->dst_address.as_u16[2] = ip0->dst_address.as_u16[3];
	  ip0->dst_address.as_u16[3] = ip0->dst_address.as_u16[4];
	  ip0->dst_address.as_u16[4] = ip0->dst_address.as_u16[5];
	  ip0->dst_address.as_u16[5] = ip0->dst_address.as_u16[6];
	  ip0->dst_address.as_u16[6] = ip0->dst_address.as_u16[7];
	  ip0->dst_address.as_u16[7] = 0x0000;

	  ip1->dst_address.as_u16[2] = ip1->dst_address.as_u16[3];
	  ip1->dst_address.as_u16[3] = ip1->dst_address.as_u16[4];
	  ip1->dst_address.as_u16[4] = ip1->dst_address.as_u16[5];
	  ip1->dst_address.as_u16[5] = ip1->dst_address.as_u16[6];
	  ip1->dst_address.as_u16[6] = ip1->dst_address.as_u16[7];
	  ip1->dst_address.as_u16[7] = 0x0000;

	  ip2->dst_address.as_u16[2] = ip2->dst_address.as_u16[3];
	  ip2->dst_address.as_u16[3] = ip2->dst_address.as_u16[4];
	  ip2->dst_address.as_u16[4] = ip2->dst_address.as_u16[5];
	  ip2->dst_address.as_u16[5] = ip2->dst_address.as_u16[6];
	  ip2->dst_address.as_u16[6] = ip2->dst_address.as_u16[7];
	  ip2->dst_address.as_u16[7] = 0x0000;

	  ip3->dst_address.as_u16[2] = ip3->dst_address.as_u16[3];
	  ip3->dst_address.as_u16[3] = ip3->dst_address.as_u16[4];
	  ip3->dst_address.as_u16[4] = ip3->dst_address.as_u16[5];
	  ip3->dst_address.as_u16[5] = ip3->dst_address.as_u16[6];
	  ip3->dst_address.as_u16[6] = ip3->dst_address.as_u16[7];
	  ip3->dst_address.as_u16[7] = 0x0000;

	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_un_localsid_trace_t *tr =
		vlib_add_trace (vm, node, b0, sizeof (*tr));
	      tr->localsid_index = ls0 - sm->localsids;
	    }

	  if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_un_localsid_trace_t *tr =
		vlib_add_trace (vm, node, b1, sizeof (*tr));
	      tr->localsid_index = ls1 - sm->localsids;
	    }

	  if (PREDICT_FALSE (b2->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_un_localsid_trace_t *tr =
		vlib_add_trace (vm, node, b2, sizeof (*tr));
	      tr->localsid_index = ls2 - sm->localsids;
	    }

	  if (PREDICT_FALSE (b3->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_un_localsid_trace_t *tr =
		vlib_add_trace (vm, node, b3, sizeof (*tr));
	      tr->localsid_index = ls3 - sm->localsids;
	    }

	  vlib_increment_combined_counter
	    (((next0 ==
	       SRV6_UN_LOCALSID_NEXT_ERROR) ?
	      &(sm->sr_ls_invalid_counters) :
	      &(sm->sr_ls_valid_counters)),
	     thread_index, ls0 - sm->localsids,
	     1, vlib_buffer_length_in_chain (vm, b0));

	  vlib_increment_combined_counter
	    (((next1 ==
	       SRV6_UN_LOCALSID_NEXT_ERROR) ?
	      &(sm->sr_ls_invalid_counters) :
	      &(sm->sr_ls_valid_counters)),
	     thread_index, ls1 - sm->localsids,
	     1, vlib_buffer_length_in_chain (vm, b1));

	  vlib_increment_combined_counter
	    (((next2 ==
	       SRV6_UN_LOCALSID_NEXT_ERROR) ?
	      &(sm->sr_ls_invalid_counters) :
	      &(sm->sr_ls_valid_counters)),
	     thread_index, ls2 - sm->localsids,
	     1, vlib_buffer_length_in_chain (vm, b2));

	  vlib_increment_combined_counter
	    (((next3 ==
	       SRV6_UN_LOCALSID_NEXT_ERROR) ?
	      &(sm->sr_ls_invalid_counters) :
	      &(sm->sr_ls_valid_counters)),
	     thread_index, ls3 - sm->localsids,
	     1, vlib_buffer_length_in_chain (vm, b3));

	  vlib_validate_buffer_enqueue_x4 (vm, node, next_index, to_next,
					   n_left_to_next, bi0, bi1, bi2, bi3,
					   next0, next1, next2, next3);
	}

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  ip6_header_t *ip0 = 0;
	  u32 next0 = SRV6_UN_LOCALSID_NEXT_IP6LOOKUP;
	  ip6_sr_localsid_t *ls0;
	  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);

	  /* 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]);

	  /* Set Destination Address to Last Segment (index 0) */
	  ip0->dst_address.as_u16[2] = ip0->dst_address.as_u16[3];
	  ip0->dst_address.as_u16[3] = ip0->dst_address.as_u16[4];
	  ip0->dst_address.as_u16[4] = ip0->dst_address.as_u16[5];
	  ip0->dst_address.as_u16[5] = ip0->dst_address.as_u16[6];
	  ip0->dst_address.as_u16[6] = ip0->dst_address.as_u16[7];
	  ip0->dst_address.as_u16[7] = 0x0000;

	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      srv6_un_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_UN_LOCALSID_NEXT_ERROR) ?
					    &(sm->sr_ls_invalid_counters) :
					    &(sm->sr_ls_valid_counters)),
					   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);

	}

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

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (srv6_un_localsid_node) = {
  .function = srv6_un_localsid_fn,
  .name = "srv6-un-localsid",
  .vector_size = sizeof (u32),
  .format_trace = format_srv6_un_localsid_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_next_nodes = SRV6_UN_LOCALSID_N_NEXT,
  .next_nodes = {
    [SRV6_UN_LOCALSID_NEXT_IP6LOOKUP] = "ip6-lookup",
    [SRV6_UN_LOCALSID_NEXT_ERROR] = "error-drop",
  },
};
/* *INDENT-ON* */

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