/*
 * Copyright (c) 2016 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <vnet/cop/cop.h>
#include <vnet/fib/ip6_fib.h>
#include <vnet/dpo/load_balance.h>

typedef struct {
  u32 next_index;
  u32 sw_if_index;
} ip6_cop_whitelist_trace_t;

/* packet trace format function */
static u8 * format_ip6_cop_whitelist_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 *);
  ip6_cop_whitelist_trace_t * t = va_arg (*args, ip6_cop_whitelist_trace_t *);
  
  s = format (s, "IP6_COP_WHITELIST: sw_if_index %d, next index %d",
              t->sw_if_index, t->next_index);
  return s;
}

vlib_node_registration_t ip6_cop_whitelist_node;

#define foreach_ip6_cop_whitelist_error                         \
_(DROPPED, "ip6 cop whitelist packets dropped")

typedef enum {
#define _(sym,str) IP6_COP_WHITELIST_ERROR_##sym,
  foreach_ip6_cop_whitelist_error
#undef _
  IP6_COP_WHITELIST_N_ERROR,
} ip6_cop_whitelist_error_t;

static char * ip6_cop_whitelist_error_strings[] = {
#define _(sym,string) string,
  foreach_ip6_cop_whitelist_error
#undef _
};

static uword
ip6_cop_whitelist_node_fn (vlib_main_t * vm,
		  vlib_node_runtime_t * node,
		  vlib_frame_t * frame)
{
  u32 n_left_from, * from, * to_next;
  cop_feature_type_t next_index;
  cop_main_t *cm = &cop_main;
  ip6_main_t * im6 = &ip6_main;
  vlib_combined_counter_main_t * vcm = &load_balance_main.lbm_via_counters;
  u32 cpu_index = vm->cpu_index;

  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);

      while (n_left_from >= 4 && n_left_to_next >= 2)
	{
          u32 bi0, bi1;
          vlib_buffer_t * b0, * b1;
          u32 next0, next1;
          u32 sw_if_index0, sw_if_index1;
          ip6_header_t * ip0, * ip1;
          cop_config_main_t * ccm0, * ccm1;
          cop_config_data_t * c0, * c1;
          u32 lb_index0, lb_index1;
          const load_balance_t * lb0, *lb1;
          const dpo_id_t *dpo0, *dpo1;
         
	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t * p2, * p3;
            
	    p2 = vlib_get_buffer (vm, from[2]);
	    p3 = vlib_get_buffer (vm, from[3]);
            
	    vlib_prefetch_buffer_header (p2, LOAD);
	    vlib_prefetch_buffer_header (p3, LOAD);

	    CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
	    CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
	  }

          /* speculatively enqueue b0 and b1 to the current next frame */
	  to_next[0] = bi0 = from[0];
	  to_next[1] = bi1 = from[1];
	  from += 2;
	  to_next += 2;
	  n_left_from -= 2;
	  n_left_to_next -= 2;

	  b0 = vlib_get_buffer (vm, bi0);
          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];

	  ip0 = vlib_buffer_get_current (b0);

	  ccm0 = cm->cop_config_mains + VNET_COP_IP6;

	  c0 = vnet_get_config_data 
              (&ccm0->config_main,
               &vnet_buffer (b0)->cop.current_config_index,
               &next0,
               sizeof (c0[0]));

          lb_index0 = ip6_fib_table_fwding_lookup (im6, c0->fib_index, 
						    &ip0->src_address);
	  lb0 = load_balance_get (lb_index0);
          dpo0 = load_balance_get_bucket_i(lb0, 0);

          if (PREDICT_FALSE(dpo0->dpoi_type != DPO_RECEIVE))
            {
              b0->error = node->errors[IP6_COP_WHITELIST_ERROR_DROPPED];
              next0 = RX_COP_DROP;
            }

	  b1 = vlib_get_buffer (vm, bi1);
          sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];

	  ip1 = vlib_buffer_get_current (b1);

	  ccm1 = cm->cop_config_mains + VNET_COP_IP6;

	  c1 = vnet_get_config_data 
              (&ccm1->config_main,
               &vnet_buffer (b1)->cop.current_config_index,
               &next1,
               sizeof (c1[0]));

          lb_index1 = ip6_fib_table_fwding_lookup (im6, c1->fib_index, 
						    &ip1->src_address);

	  lb1 = load_balance_get (lb_index1);
          dpo1 = load_balance_get_bucket_i(lb1, 0);

          vlib_increment_combined_counter 
              (vcm, cpu_index, lb_index0, 1,
               vlib_buffer_length_in_chain (vm, b0) 
               + sizeof(ethernet_header_t));

          vlib_increment_combined_counter 
              (vcm, cpu_index, lb_index1, 1,
               vlib_buffer_length_in_chain (vm, b1)
               + sizeof(ethernet_header_t));

          if (PREDICT_FALSE(dpo1->dpoi_type != DPO_RECEIVE))
            {
              b1->error = node->errors[IP6_COP_WHITELIST_ERROR_DROPPED];
              next1 = RX_COP_DROP;
            }

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
                            && (b0->flags & VLIB_BUFFER_IS_TRACED))) 
            {
              ip6_cop_whitelist_trace_t *t = 
                 vlib_add_trace (vm, node, b0, sizeof (*t));
              t->sw_if_index = sw_if_index0;
              t->next_index = next0;
            }

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
                            && (b1->flags & VLIB_BUFFER_IS_TRACED))) 
            {
              ip6_cop_whitelist_trace_t *t = 
                 vlib_add_trace (vm, node, b1, sizeof (*t));
              t->sw_if_index = sw_if_index1;
              t->next_index = next1;
            }

          /* verify speculative enqueues, maybe switch current next frame */
          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
                                           to_next, n_left_to_next,
                                           bi0, bi1, next0, next1);
        }

      while (n_left_from > 0 && n_left_to_next > 0)
	{
          u32 bi0;
	  vlib_buffer_t * b0;
          u32 next0;
          u32 sw_if_index0;
          ip6_header_t * ip0;
          cop_config_main_t *ccm0;
          cop_config_data_t *c0;
          u32 lb_index0;
          const load_balance_t * lb0;
          const dpo_id_t *dpo0;

          /* speculatively enqueue b0 to the current next frame */
	  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);
          sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];

	  ip0 = vlib_buffer_get_current (b0);

	  ccm0 = cm->cop_config_mains + VNET_COP_IP6;

	  c0 = vnet_get_config_data 
              (&ccm0->config_main,
               &vnet_buffer (b0)->cop.current_config_index,
               &next0,
               sizeof (c0[0]));

          lb_index0 = ip6_fib_table_fwding_lookup (im6, c0->fib_index, 
						    &ip0->src_address);

	  lb0 = load_balance_get (lb_index0);
          dpo0 = load_balance_get_bucket_i(lb0, 0);

          vlib_increment_combined_counter 
              (vcm, cpu_index, lb_index0, 1,
               vlib_buffer_length_in_chain (vm, b0) 
               + sizeof(ethernet_header_t));

          if (PREDICT_FALSE(dpo0->dpoi_type != DPO_RECEIVE))
            {
              b0->error = node->errors[IP6_COP_WHITELIST_ERROR_DROPPED];
              next0 = RX_COP_DROP;
            }

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
                            && (b0->flags & VLIB_BUFFER_IS_TRACED))) 
            {
              ip6_cop_whitelist_trace_t *t = 
                 vlib_add_trace (vm, node, b0, sizeof (*t));
              t->sw_if_index = sw_if_index0;
              t->next_index = next0;
            }
            
          /* verify speculative enqueue, maybe switch current next frame */
	  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;
}

VLIB_REGISTER_NODE (ip6_cop_whitelist_node) = {
  .function = ip6_cop_whitelist_node_fn,
  .name = "ip6-cop-whitelist",
  .vector_size = sizeof (u32),
  .format_trace = format_ip6_cop_whitelist_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  
  .n_errors = ARRAY_LEN(ip6_cop_whitelist_error_strings),
  .error_strings = ip6_cop_whitelist_error_strings,

  .n_next_nodes = COP_RX_N_FEATURES,

  /* edit / add dispositions here */
  .next_nodes = {
    [IP4_RX_COP_WHITELIST] = "ip4-cop-whitelist",
    [IP6_RX_COP_WHITELIST] = "ip6-cop-whitelist",
    [DEFAULT_RX_COP_WHITELIST] = "default-cop-whitelist",
    [IP4_RX_COP_INPUT] = "ip4-input",
    [IP6_RX_COP_INPUT] = "ip6-input",
    [DEFAULT_RX_COP_INPUT] = "ethernet-input",
    [RX_COP_DROP] = "error-drop",
  },
};

VLIB_NODE_FUNCTION_MULTIARCH (ip6_cop_whitelist_node, ip6_cop_whitelist_node_fn)

static clib_error_t *
ip6_whitelist_init (vlib_main_t * vm)
{
  return 0;
}

VLIB_INIT_FUNCTION (ip6_whitelist_init);