/*
 * 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.
 */
/*
 * l2_classify.c
 */

#include <vnet/l2/l2_classify.h>
#include <vnet/api_errno.h>

typedef struct {
  /* per-pkt trace data */ 
  u32 sw_if_index;
  u32 next_index;
  u32 table_index;
  u32 session_offset;
} l2_classify_trace_t;

typedef struct {
  vnet_classify_main_t * vcm;
  l2_classify_main_t * l2cm;
} l2_classify_runtime_t;

/* packet trace format function */
static u8 * format_l2_classify_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 *);
  l2_classify_trace_t * t = va_arg (*args, l2_classify_trace_t *);
  
  s = format (s, "l2-classify: sw_if_index %d, table %d, offset %x, next %d",
	      t->sw_if_index, t->table_index, t->session_offset, t->next_index);
  return s;
}

l2_classify_main_t l2_classify_main;

vlib_node_registration_t l2_classify_node;

#define foreach_l2_classify_error               \
_(MISS, "Classify misses")                      \
_(HIT, "Classify hits")                         \
_(CHAIN_HIT, "Classify hits after chain walk")  \
_(DROP, "L2 Classify Drops")

typedef enum {
#define _(sym,str) L2_CLASSIFY_ERROR_##sym,
  foreach_l2_classify_error
#undef _
  L2_CLASSIFY_N_ERROR,
} l2_classify_error_t;

static char * l2_classify_error_strings[] = {
#define _(sym,string) string,
  foreach_l2_classify_error
#undef _
};

static uword
l2_classify_node_fn (vlib_main_t * vm,
		  vlib_node_runtime_t * node,
		  vlib_frame_t * frame)
{
  u32 n_left_from, * from, * to_next;
  l2_classify_next_t next_index;
  l2_classify_main_t * cm = &l2_classify_main;
  vnet_classify_main_t * vcm = cm->vnet_classify_main;
  l2_classify_runtime_t * rt = (l2_classify_runtime_t *)node->runtime_data;
  u32 feature_bitmap;
  u32 hits = 0;
  u32 misses = 0;
  u32 chain_hits = 0;
  f64 now;
  
  now = vlib_time_now(vm);

  n_left_from = frame->n_vectors;
  from = vlib_frame_vector_args (frame);

  /* First pass: compute hash */

  while (n_left_from > 2)
    {
      vlib_buffer_t * b0, * b1;
      u32 bi0, bi1;
      ethernet_header_t * h0, * h1;
      u32 sw_if_index0, sw_if_index1;
      u16 type0, type1;
      int type_index0, type_index1;
      vnet_classify_table_t * t0, * t1;
      u32 table_index0, table_index1;
      u64 hash0, hash1;


      /* prefetch next iteration */
        {
          vlib_buffer_t * p1, * p2;
          
          p1 = vlib_get_buffer (vm, from[1]);
          p2 = vlib_get_buffer (vm, from[2]);
          
          vlib_prefetch_buffer_header (p1, STORE);
          CLIB_PREFETCH (p1->data, CLIB_CACHE_LINE_BYTES, STORE);
          vlib_prefetch_buffer_header (p2, STORE);
          CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
        }
        
      bi0 = from[0];
      b0 = vlib_get_buffer (vm, bi0);
      h0 = vlib_buffer_get_current (b0);

      bi1 = from[1];
      b1 = vlib_get_buffer (vm, bi1);
      h1 = vlib_buffer_get_current (b1);
        
      sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
      vnet_buffer(b0)->l2_classify.table_index = ~0;

      sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
      vnet_buffer(b1)->l2_classify.table_index = ~0;
        
      /* Select classifier table based on ethertype */
      type0 = clib_net_to_host_u16 (h0->type);
      type1 = clib_net_to_host_u16 (h1->type);

      type_index0 = (type0 == ETHERNET_TYPE_IP4) 
          ? L2_CLASSIFY_TABLE_IP4 : L2_CLASSIFY_TABLE_OTHER;
      type_index0 = (type0 == ETHERNET_TYPE_IP6) 
          ? L2_CLASSIFY_TABLE_IP6 : type_index0;

      type_index1 = (type1 == ETHERNET_TYPE_IP4) 
          ? L2_CLASSIFY_TABLE_IP4 : L2_CLASSIFY_TABLE_OTHER;
      type_index1 = (type1 == ETHERNET_TYPE_IP6) 
          ? L2_CLASSIFY_TABLE_IP6 : type_index1;
      
      vnet_buffer(b0)->l2_classify.table_index = 
          table_index0 = 
          rt->l2cm->classify_table_index_by_sw_if_index
          [type_index0][sw_if_index0];
            
      if (table_index0 != ~0)
        {
          t0 = pool_elt_at_index (vcm->tables, table_index0);
          
          vnet_buffer(b0)->l2_classify.hash = hash0 = 
              vnet_classify_hash_packet (t0, (u8 *) h0);
          vnet_classify_prefetch_bucket (t0, hash0);
        }

      vnet_buffer(b1)->l2_classify.table_index = 
        table_index1 = 
        rt->l2cm->classify_table_index_by_sw_if_index
        [type_index1][sw_if_index1];
      
      if (table_index1 != ~0)
        {
          t1 = pool_elt_at_index (vcm->tables, table_index1);
          
          vnet_buffer(b1)->l2_classify.hash = hash1 = 
            vnet_classify_hash_packet (t1, (u8 *) h1);
          vnet_classify_prefetch_bucket (t1, hash1);
        }

      from += 2;
      n_left_from -= 2;
    }

  while (n_left_from > 0)
    {
      vlib_buffer_t * b0;
      u32 bi0;
      ethernet_header_t * h0;
      u32 sw_if_index0;
      u16 type0;
      u32 type_index0;
      vnet_classify_table_t * t0;
      u32 table_index0;
      u64 hash0;

      bi0 = from[0];
      b0 = vlib_get_buffer (vm, bi0);
      h0 = vlib_buffer_get_current (b0);
        
      sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
      vnet_buffer(b0)->l2_classify.table_index = ~0;
        
      /* Select classifier table based on ethertype */
      type0 = clib_net_to_host_u16 (h0->type);
        
      type_index0 = (type0 == ETHERNET_TYPE_IP4) 
          ? L2_CLASSIFY_TABLE_IP4 : L2_CLASSIFY_TABLE_OTHER;
      type_index0 = (type0 == ETHERNET_TYPE_IP6) 
          ? L2_CLASSIFY_TABLE_IP6 : type_index0;

      vnet_buffer(b0)->l2_classify.table_index = 
          table_index0 = rt->l2cm->classify_table_index_by_sw_if_index
          [type_index0][sw_if_index0];
            
      if (table_index0 != ~0)
        {
          t0 = pool_elt_at_index (vcm->tables, table_index0);
          
          vnet_buffer(b0)->l2_classify.hash = hash0 = 
            vnet_classify_hash_packet (t0, (u8 *) h0);
          vnet_classify_prefetch_bucket (t0, hash0);
        }
      from++;
      n_left_from--;
    }
        
  next_index = node->cached_next_index;
  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

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

      /* Not enough load/store slots to dual loop... */
      while (n_left_from > 0 && n_left_to_next > 0)
	{
          u32 bi0;
	  vlib_buffer_t * b0;
          u32 next0 = L2_CLASSIFY_NEXT_ETHERNET_INPUT;
          ethernet_header_t * h0;
          u32 table_index0;
          u64 hash0;
          vnet_classify_table_t * t0;
          vnet_classify_entry_t * e0;

          if (PREDICT_TRUE (n_left_from > 2))
            {
              vlib_buffer_t * p2 = vlib_get_buffer(vm, from[2]);
              u64 phash2;
              u32 table_index2;
              vnet_classify_table_t * tp2;

              /* 
               * Prefetch table entry two ahead. Buffer / data
               * were prefetched above...
               */
              table_index2 = vnet_buffer(p2)->l2_classify.table_index;

              if (PREDICT_TRUE (table_index2 != ~0))
                {
                  tp2 = pool_elt_at_index (vcm->tables, table_index2);
                  phash2 = vnet_buffer(p2)->l2_classify.hash;
                  vnet_classify_prefetch_entry (tp2, phash2); 
                }
            }

          /* 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);
          h0 = vlib_buffer_get_current(b0);
          table_index0 = vnet_buffer(b0)->l2_classify.table_index;
          e0 = 0;

          if (PREDICT_TRUE(table_index0 != ~0))
            {
              hash0 = vnet_buffer(b0)->l2_classify.hash;
              t0 = pool_elt_at_index (vcm->tables, table_index0);

              e0 = vnet_classify_find_entry (t0, (u8 *) h0, 
                                             hash0, now);
              if (e0)
                {
                  vnet_buffer(b0)->l2_classify.opaque_index 
                    = e0->opaque_index;
                  vlib_buffer_advance (b0, e0->advance);
                  next0 = (e0->next_index < L2_CLASSIFY_N_NEXT)?
                           e0->next_index:next0;
                  hits++;
                }
              else
                {
                  while (1)
                    {
                      if (t0->next_table_index != ~0)
                        t0 = pool_elt_at_index (vcm->tables,
                                                t0->next_table_index);
                      else
                        {
                          next0 = (t0->miss_next_index < L2_CLASSIFY_N_NEXT)?
                                   t0->miss_next_index:next0;
                          misses++;
                          break;
                        }

                      hash0 = vnet_classify_hash_packet (t0, (u8 *) h0);
                      e0 = vnet_classify_find_entry (t0, (u8 *) h0, hash0, now);
                      if (e0)
                        {
                          vnet_buffer(b0)->l2_classify.opaque_index
                            = e0->opaque_index;
                          vlib_buffer_advance (b0, e0->advance);
                          next0 = (e0->next_index < L2_CLASSIFY_N_NEXT)?
                                   e0->next_index:next0;
                          hits++;
                          chain_hits++;
                          break;
                        }
                    }
                }
            }

          if (PREDICT_FALSE(next0 == 0))
            b0->error = node->errors[L2_CLASSIFY_ERROR_DROP];

          if (PREDICT_FALSE (next0 == ~0))
            {
            
              // Remove ourself from the feature bitmap
              feature_bitmap = vnet_buffer(b0)->l2.feature_bitmap 
                & ~L2INPUT_FEAT_CLASSIFY;
              
              // save for next feature graph nodes
              vnet_buffer(b0)->l2.feature_bitmap = feature_bitmap;

              // Determine the next node
              next0 = feat_bitmap_get_next_node_index(cm->feat_next_node_index,
                                                      feature_bitmap);
            }

          if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) 
                            && (b0->flags & VLIB_BUFFER_IS_TRACED))) 
            {
              l2_classify_trace_t *t = 
                vlib_add_trace (vm, node, b0, sizeof (*t));
              t->sw_if_index = vnet_buffer(b0)->sw_if_index[VLIB_RX];
              t->table_index = table_index0;
              t->next_index = next0;
              t->session_offset = e0 ? vnet_classify_get_offset (t0, e0) : 0;
            }

          /* 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);
    }

  vlib_node_increment_counter (vm, node->node_index, 
                               L2_CLASSIFY_ERROR_MISS, 
                               misses);
  vlib_node_increment_counter (vm, node->node_index, 
                               L2_CLASSIFY_ERROR_HIT, 
                               hits);
  vlib_node_increment_counter (vm, node->node_index, 
                               L2_CLASSIFY_ERROR_CHAIN_HIT, 
                               chain_hits);
  return frame->n_vectors;
}

VLIB_REGISTER_NODE (l2_classify_node) = {
  .function = l2_classify_node_fn,
  .name = "l2-classify",
  .vector_size = sizeof (u32),
  .format_trace = format_l2_classify_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  
  .n_errors = ARRAY_LEN(l2_classify_error_strings),
  .error_strings = l2_classify_error_strings,

  .runtime_data_bytes = sizeof (l2_classify_runtime_t),

  .n_next_nodes = L2_CLASSIFY_N_NEXT,

  /* edit / add dispositions here */
  .next_nodes = {
       [L2_CLASSIFY_NEXT_DROP]  = "error-drop",
       [L2_CLASSIFY_NEXT_ETHERNET_INPUT] = "ethernet-input-not-l2",
       [L2_CLASSIFY_NEXT_IP4_INPUT] = "ip4-input",
       [L2_CLASSIFY_NEXT_IP6_INPUT] = "ip6-input",
       [L2_CLASSIFY_NEXT_LI] = "li-hit",
  },
};

clib_error_t *l2_classify_init (vlib_main_t *vm)
{
  l2_classify_main_t * cm = &l2_classify_main;
  l2_classify_runtime_t * rt;

  rt = vlib_node_get_runtime_data (vm, l2_classify_node.index);
 
  cm->vlib_main = vm;
  cm->vnet_main = vnet_get_main();
  cm->vnet_classify_main = &vnet_classify_main;

  // Initialize the feature next-node indexes
  feat_bitmap_init_next_nodes(vm,
                              l2_classify_node.index,
                              L2INPUT_N_FEAT,
                              l2input_get_feat_names(),
                              cm->feat_next_node_index);
  rt->l2cm = cm;
  rt->vcm = cm->vnet_classify_main;

  return 0;
}

VLIB_INIT_FUNCTION (l2_classify_init);


void vnet_l2_classify_enable_disable (u32 sw_if_index,
                                      int enable_disable)
{
  vlib_main_t * vm = vlib_get_main();
  vnet_main_t * vnm = vnet_get_main();
  
  if (enable_disable)
    set_int_l2_mode (vm, vnm, MODE_L2_CLASSIFY, sw_if_index,
                     0, 0, 0, 0);
  else
    set_int_l2_mode (vm, vnm, MODE_L3, sw_if_index,
                     0, 0, 0, 0);
}

int vnet_l2_classify_set_tables (u32 sw_if_index, 
                                 u32 ip4_table_index, 
                                 u32 ip6_table_index, 
                                 u32 other_table_index)
{
  l2_classify_main_t * cm = &l2_classify_main;
  vnet_classify_main_t * vcm = cm->vnet_classify_main;

  /* Assume that we've validated sw_if_index in the API layer */

  if (ip4_table_index != ~0 &&
      pool_is_free_index (vcm->tables, ip4_table_index))
    return VNET_API_ERROR_NO_SUCH_TABLE;

  if (ip6_table_index != ~0 &&
      pool_is_free_index (vcm->tables, ip6_table_index))
    return VNET_API_ERROR_NO_SUCH_TABLE2;
  
  if (other_table_index != ~0 &&
      pool_is_free_index (vcm->tables, other_table_index))
    return VNET_API_ERROR_NO_SUCH_TABLE3;
  
  vec_validate 
    (cm->classify_table_index_by_sw_if_index[L2_CLASSIFY_TABLE_IP4], 
     sw_if_index);
  
  vec_validate 
    (cm->classify_table_index_by_sw_if_index[L2_CLASSIFY_TABLE_IP6], 
     sw_if_index);
  
  vec_validate 
    (cm->classify_table_index_by_sw_if_index[L2_CLASSIFY_TABLE_OTHER], 
     sw_if_index);

  cm->classify_table_index_by_sw_if_index[L2_CLASSIFY_TABLE_IP4]
    [sw_if_index] = ip4_table_index;
  
  cm->classify_table_index_by_sw_if_index[L2_CLASSIFY_TABLE_IP6]
    [sw_if_index] = ip6_table_index;
  
  cm->classify_table_index_by_sw_if_index[L2_CLASSIFY_TABLE_OTHER]
    [sw_if_index] = other_table_index;

  return 0;
}

static clib_error_t *
int_l2_classify_command_fn (vlib_main_t * vm,
                            unformat_input_t * input,
                            vlib_cli_command_t * cmd)
{
  vnet_main_t * vnm = vnet_get_main();
  u32 sw_if_index = ~0;
  u32 ip4_table_index = ~0;
  u32 ip6_table_index = ~0;
  u32 other_table_index = ~0;
  int rv;

  while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "intfc %U", unformat_vnet_sw_interface, 
                    vnm, &sw_if_index))
        ;
      else if (unformat (input, "ip4-table %d", &ip4_table_index))
        ;
      else if (unformat (input, "ip6-table %d", &ip6_table_index))
        ;
      else if (unformat (input, "other-table %d", &other_table_index))
        ;
      else
        break;
    }

  if (sw_if_index == ~0)
    return clib_error_return (0, "interface must be specified");
  

  if (ip4_table_index == ~0 && ip6_table_index == ~0 
      && other_table_index == ~0)
    {
      vlib_cli_output (vm, "L2 classification disabled");
      vnet_l2_classify_enable_disable (sw_if_index, 0 /* enable */);
      return 0;
    }

  rv = vnet_l2_classify_set_tables (sw_if_index, ip4_table_index, 
                                    ip6_table_index, other_table_index);
  switch(rv)
    {
    case 0:
      vnet_l2_classify_enable_disable (sw_if_index, 1 /* enable */);
      break;

    default:
      return clib_error_return (0, "vnet_l2_classify_set_tables: %d",
                                rv);
      break;
    }

  return 0;
}

VLIB_CLI_COMMAND (int_l2_classify_cli, static) = {
  .path = "set interface l2 classify",
  .short_help = 
  "set interface l2 classify intfc <int> [ip4-table <n>]\n"
  "  [ip6-table <n>] [other-table <n>]",
  .function = int_l2_classify_command_fn,
};