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path: root/src/vnet/l2/l2_rw.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 <vlib/vlib.h>
#include <vnet/l2/feat_bitmap.h>
#include <vnet/l2/l2_rw.h>

/**
 * @file
 * @brief Layer 2 Rewrite.
 *
 * Layer 2-Rewrite node uses classify tables to match packets. Then, using
 * the provisioned mask and value, modifies the packet header.
 */


#ifndef CLIB_MARCH_VARIANT
l2_rw_main_t l2_rw_main;
#endif /* CLIB_MARCH_VARIANT */

typedef struct
{
  u32 sw_if_index;
  u32 classify_table_index;
  u32 rewrite_entry_index;
} l2_rw_trace_t;

static u8 *
format_l2_rw_entry (u8 * s, va_list * args)
{
  l2_rw_entry_t *e = va_arg (*args, l2_rw_entry_t *);
  l2_rw_main_t *rw = &l2_rw_main;
  s = format (s, "%d -  mask:%U value:%U\n",
	      e - rw->entries,
	      format_hex_bytes, e->mask,
	      e->rewrite_n_vectors * sizeof (u32x4), format_hex_bytes,
	      e->value, e->rewrite_n_vectors * sizeof (u32x4));
  s =
    format (s, "      hits:%d skip_bytes:%d", e->hit_count,
	    e->skip_n_vectors * sizeof (u32x4));
  return s;
}

static u8 *
format_l2_rw_config (u8 * s, va_list * args)
{
  l2_rw_config_t *c = va_arg (*args, l2_rw_config_t *);
  return format (s, "table-index:%d miss-index:%d",
		 c->table_index, c->miss_index);
}

/* packet trace format function */
static u8 *
format_l2_rw_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_rw_trace_t *t = va_arg (*args, l2_rw_trace_t *);
  return format (s, "l2-rw: sw_if_index %d, table %d, entry %d",
		 t->sw_if_index, t->classify_table_index,
		 t->rewrite_entry_index);
}

always_inline l2_rw_config_t *
l2_rw_get_config (u32 sw_if_index)
{
  l2_rw_main_t *rw = &l2_rw_main;
  if (PREDICT_FALSE (!clib_bitmap_get (rw->configs_bitmap, sw_if_index)))
    {
      vec_validate (rw->configs, sw_if_index);
      rw->configs[sw_if_index].table_index = ~0;
      rw->configs[sw_if_index].miss_index = ~0;
      rw->configs_bitmap =
	clib_bitmap_set (rw->configs_bitmap, sw_if_index, 1);
    }
  return &rw->configs[sw_if_index];
}

static_always_inline void
l2_rw_rewrite (l2_rw_entry_t * rwe, u8 * h)
{
  if (U32X4_ALIGNED (h))
    {
      u32x4 *d = ((u32x4 *) h) + rwe->skip_n_vectors;
      switch (rwe->rewrite_n_vectors)
	{
	case 5:
	  d[4] = (d[4] & ~rwe->mask[4]) | rwe->value[4];
	  /* FALLTHROUGH */
	case 4:
	  d[3] = (d[3] & ~rwe->mask[3]) | rwe->value[3];
	  /* FALLTHROUGH */
	case 3:
	  d[2] = (d[2] & ~rwe->mask[2]) | rwe->value[2];
	  /* FALLTHROUGH */
	case 2:
	  d[1] = (d[1] & ~rwe->mask[1]) | rwe->value[1];
	  /* FALLTHROUGH */
	case 1:
	  d[0] = (d[0] & ~rwe->mask[0]) | rwe->value[0];
	  break;
	default:
	  abort ();
	}
    }
  else
    {
      u64 *d = ((u64 *) h) + rwe->skip_n_vectors * 2;
      switch (rwe->rewrite_n_vectors)
	{
	case 5:
	  d[8] =
	    (d[8] & ~(((u64 *) rwe->mask)[8])) | (((u64 *) rwe->value)[8]);
	  d[9] =
	    (d[9] & ~(((u64 *) rwe->mask)[9])) | (((u64 *) rwe->value)[9]);
	  /* FALLTHROUGH */
	case 4:
	  d[6] =
	    (d[6] & ~(((u64 *) rwe->mask)[6])) | (((u64 *) rwe->value)[6]);
	  d[7] =
	    (d[7] & ~(((u64 *) rwe->mask)[7])) | (((u64 *) rwe->value)[7]);
	  /* FALLTHROUGH */
	case 3:
	  d[4] =
	    (d[4] & ~(((u64 *) rwe->mask)[4])) | (((u64 *) rwe->value)[4]);
	  d[5] =
	    (d[5] & ~(((u64 *) rwe->mask)[5])) | (((u64 *) rwe->value)[5]);
	  /* FALLTHROUGH */
	case 2:
	  d[2] =
	    (d[2] & ~(((u64 *) rwe->mask)[2])) | (((u64 *) rwe->value)[2]);
	  d[3] =
	    (d[3] & ~(((u64 *) rwe->mask)[3])) | (((u64 *) rwe->value)[3]);
	  /* FALLTHROUGH */
	case 1:
	  d[0] =
	    (d[0] & ~(((u64 *) rwe->mask)[0])) | (((u64 *) rwe->value)[0]);
	  d[1] =
	    (d[1] & ~(((u64 *) rwe->mask)[1])) | (((u64 *) rwe->value)[1]);
	  break;
	default:
	  abort ();
	}
    }
}

VLIB_NODE_FN (l2_rw_node) (vlib_main_t * vm,
			   vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  l2_rw_main_t *rw = &l2_rw_main;
  u32 n_left_from, *from, *to_next, next_index;
  vnet_classify_main_t *vcm = &vnet_classify_main;
  f64 now = vlib_time_now (vlib_get_main ());

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;	/* number of packets to process */
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      /* get space to enqueue frame to graph node "next_index" */
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from >= 6 && n_left_to_next >= 2)
	{
	  u32 bi0, next0, sw_if_index0, rwe_index0;
	  u32 bi1, next1, sw_if_index1, rwe_index1;
	  vlib_buffer_t *b0, *b1;
	  ethernet_header_t *h0, *h1;
	  l2_rw_config_t *config0, *config1;
	  u64 hash0, hash1;
	  vnet_classify_table_t *t0, *t1;
	  vnet_classify_entry_t *e0, *e1;
	  l2_rw_entry_t *rwe0, *rwe1;

	  {
	    vlib_buffer_t *p2, *p3, *p4, *p5;
	    p2 = vlib_get_buffer (vm, from[2]);
	    p3 = vlib_get_buffer (vm, from[3]);
	    p4 = vlib_get_buffer (vm, from[4]);
	    p5 = vlib_get_buffer (vm, from[5]);

	    vlib_prefetch_buffer_header (p4, LOAD);
	    vlib_prefetch_buffer_header (p5, LOAD);
	    vlib_prefetch_buffer_data (p2, LOAD);
	    vlib_prefetch_buffer_data (p3, LOAD);
	  }

	  bi0 = from[0];
	  bi1 = from[1];
	  to_next[0] = bi0;
	  to_next[1] = bi1;
	  from += 2;
	  to_next += 2;
	  n_left_from -= 2;
	  n_left_to_next -= 2;

	  b0 = vlib_get_buffer (vm, bi0);
	  b1 = vlib_get_buffer (vm, bi1);
	  h0 = vlib_buffer_get_current (b0);
	  h1 = vlib_buffer_get_current (b1);

	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
	  config0 = l2_rw_get_config (sw_if_index0);	/*TODO: check sw_if_index0 value */
	  config1 = l2_rw_get_config (sw_if_index1);	/*TODO: check sw_if_index0 value */
	  t0 = pool_elt_at_index (vcm->tables, config0->table_index);
	  t1 = pool_elt_at_index (vcm->tables, config1->table_index);

	  hash0 = vnet_classify_hash_packet (t0, (u8 *) h0);
	  hash1 = vnet_classify_hash_packet (t1, (u8 *) h1);
	  e0 = vnet_classify_find_entry (t0, (u8 *) h0, hash0, now);
	  e1 = vnet_classify_find_entry (t1, (u8 *) h1, hash1, now);

	  while (!e0 && (t0->next_table_index != ~0))
	    {
	      t0 = pool_elt_at_index (vcm->tables, t0->next_table_index);
	      hash0 = vnet_classify_hash_packet (t0, (u8 *) h0);
	      e0 = vnet_classify_find_entry (t0, (u8 *) h0, hash0, now);
	    }

	  while (!e1 && (t1->next_table_index != ~0))
	    {
	      t1 = pool_elt_at_index (vcm->tables, t1->next_table_index);
	      hash1 = vnet_classify_hash_packet (t1, (u8 *) h1);
	      e1 = vnet_classify_find_entry (t1, (u8 *) h1, hash1, now);
	    }

	  rwe_index0 = e0 ? e0->opaque_index : config0->miss_index;
	  rwe_index1 = e1 ? e1->opaque_index : config1->miss_index;

	  if (rwe_index0 != ~0)
	    {
	      rwe0 = pool_elt_at_index (rw->entries, rwe_index0);
	      l2_rw_rewrite (rwe0, (u8 *) h0);
	    }
	  if (rwe_index1 != ~0)
	    {
	      rwe1 = pool_elt_at_index (rw->entries, rwe_index1);
	      l2_rw_rewrite (rwe1, (u8 *) h1);
	    }

	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      l2_rw_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
	      t->sw_if_index = sw_if_index0;
	      t->classify_table_index = config0->table_index;
	      t->rewrite_entry_index = rwe_index0;
	    }

	  if (PREDICT_FALSE ((b1->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      l2_rw_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t));
	      t->sw_if_index = sw_if_index1;
	      t->classify_table_index = config1->table_index;
	      t->rewrite_entry_index = rwe_index1;
	    }

	  /* Update feature bitmap and get next feature index */
	  next0 = vnet_l2_feature_next (b0, rw->feat_next_node_index,
					L2INPUT_FEAT_RW);
	  next1 = vnet_l2_feature_next (b1, rw->feat_next_node_index,
					L2INPUT_FEAT_RW);

	  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, next0, sw_if_index0, rwe_index0;
	  vlib_buffer_t *b0;
	  ethernet_header_t *h0;
	  l2_rw_config_t *config0;
	  u64 hash0;
	  vnet_classify_table_t *t0;
	  vnet_classify_entry_t *e0;
	  l2_rw_entry_t *rwe0;

	  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);

	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
	  config0 = l2_rw_get_config (sw_if_index0);	/*TODO: check sw_if_index0 value */
	  t0 = pool_elt_at_index (vcm->tables, config0->table_index);

	  hash0 = vnet_classify_hash_packet (t0, (u8 *) h0);
	  e0 = vnet_classify_find_entry (t0, (u8 *) h0, hash0, now);

	  while (!e0 && (t0->next_table_index != ~0))
	    {
	      t0 = pool_elt_at_index (vcm->tables, t0->next_table_index);
	      hash0 = vnet_classify_hash_packet (t0, (u8 *) h0);
	      e0 = vnet_classify_find_entry (t0, (u8 *) h0, hash0, now);
	    }

	  rwe_index0 = e0 ? e0->opaque_index : config0->miss_index;

	  if (rwe_index0 != ~0)
	    {
	      rwe0 = pool_elt_at_index (rw->entries, rwe_index0);
	      l2_rw_rewrite (rwe0, (u8 *) h0);
	    }

	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
	    {
	      l2_rw_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
	      t->sw_if_index = sw_if_index0;
	      t->classify_table_index = config0->table_index;
	      t->rewrite_entry_index = rwe_index0;
	    }

	  /* Update feature bitmap and get next feature index */
	  next0 = vnet_l2_feature_next (b0, rw->feat_next_node_index,
					L2INPUT_FEAT_RW);

	  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;
}

#ifndef CLIB_MARCH_VARIANT
int
l2_rw_mod_entry (u32 * index,
		 u8 * mask, u8 * value, u32 len, u32 skip, u8 is_del)
{
  l2_rw_main_t *rw = &l2_rw_main;
  l2_rw_entry_t *e = 0;
  if (*index != ~0)
    {
      if (pool_is_free_index (rw->entries, *index))
	{
	  return -1;
	}
      e = pool_elt_at_index (rw->entries, *index);
    }
  else
    {
      pool_get (rw->entries, e);
      *index = e - rw->entries;
    }

  if (!e)
    return -1;

  if (is_del)
    {
      pool_put (rw->entries, e);
      return 0;
    }

  e->skip_n_vectors = skip / sizeof (u32x4);
  skip -= e->skip_n_vectors * sizeof (u32x4);
  e->rewrite_n_vectors = (skip + len - 1) / sizeof (u32x4) + 1;
  vec_alloc_aligned (e->mask, e->rewrite_n_vectors, sizeof (u32x4));
  clib_memset (e->mask, 0, e->rewrite_n_vectors * sizeof (u32x4));
  vec_alloc_aligned (e->value, e->rewrite_n_vectors, sizeof (u32x4));
  clib_memset (e->value, 0, e->rewrite_n_vectors * sizeof (u32x4));

  clib_memcpy (((u8 *) e->value) + skip, value, len);
  clib_memcpy (((u8 *) e->mask) + skip, mask, len);

  int i;
  for (i = 0; i < e->rewrite_n_vectors; i++)
    {
      e->value[i] &= e->mask[i];
    }

  return 0;
}
#endif /* CLIB_MARCH_VARIANT */

static clib_error_t *
l2_rw_entry_cli_fn (vlib_main_t * vm,
		    unformat_input_t * input, vlib_cli_command_t * cmd)
{
  u32 index = ~0;
  u8 *mask = 0;
  u8 *value = 0;
  u32 skip = 0;
  u8 del = 0;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "index %d", &index))
	;
      else if (unformat (input, "mask %U", unformat_hex_string, &mask))
	;
      else if (unformat (input, "value %U", unformat_hex_string, &value))
	;
      else if (unformat (input, "skip %d", &skip))
	;
      else if (unformat (input, "del"))
	del = 1;
      else
	break;
    }

  if (!mask || !value)
    return clib_error_return (0, "Unspecified mask or value");

  if (vec_len (mask) != vec_len (value))
    return clib_error_return (0, "Mask and value lengths must be identical");

  int ret;
  if ((ret =
       l2_rw_mod_entry (&index, mask, value, vec_len (mask), skip, del)))
    return clib_error_return (0, "Could not add entry");

  return 0;
}

/*?
 * Layer 2-Rewrite node uses classify tables to match packets. Then, using
 * the provisioned mask and value, modifies the packet header.
 *
 * @cliexpar
 * @todo This is incomplete. This needs a detailed description and a
 * practical example.
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (l2_rw_entry_cli, static) = {
  .path = "l2 rewrite entry",
  .short_help =
  "l2 rewrite entry [index <index>] [mask <hex-mask>] [value <hex-value>] [skip <n_bytes>] [del]",
  .function = l2_rw_entry_cli_fn,
};
/* *INDENT-ON* */

#ifndef CLIB_MARCH_VARIANT
int
l2_rw_interface_set_table (u32 sw_if_index, u32 table_index, u32 miss_index)
{
  l2_rw_config_t *c = l2_rw_get_config (sw_if_index);
  l2_rw_main_t *rw = &l2_rw_main;

  c->table_index = table_index;
  c->miss_index = miss_index;
  u32 feature_bitmap = (table_index == ~0) ? 0 : L2INPUT_FEAT_RW;

  l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_RW, feature_bitmap);

  if (c->table_index == ~0)
    clib_bitmap_set (rw->configs_bitmap, sw_if_index, 0);

  return 0;
}
#endif /* CLIB_MARCH_VARIANT */

static clib_error_t *
l2_rw_interface_cli_fn (vlib_main_t * vm,
			unformat_input_t * input, vlib_cli_command_t * cmd)
{
  vnet_main_t *vnm = vnet_get_main ();
  u32 table_index = ~0;
  u32 sw_if_index = ~0;
  u32 miss_index = ~0;

  if (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      unformat (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index);
    }

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "table %d", &table_index))
	;
      else if (unformat (input, "miss-index %d", &miss_index))
	;
      else
	break;
    }

  if (sw_if_index == ~0)
    return clib_error_return (0,
			      "You must specify an interface 'iface <interface>'",
			      format_unformat_error, input);
  int ret;
  if ((ret =
       l2_rw_interface_set_table (sw_if_index, table_index, miss_index)))
    return clib_error_return (0, "l2_rw_interface_set_table returned %d",
			      ret);

  return 0;
}

/*?
 * Layer 2-Rewrite node uses classify tables to match packets. Then, using
 * the provisioned mask and value, modifies the packet header.
 *
 * @cliexpar
 * @todo This is incomplete. This needs a detailed description and a
 * practical example.
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (l2_rw_interface_cli, static) = {
  .path = "set interface l2 rewrite",
  .short_help =
  "set interface l2 rewrite <interface> [table <table index>] [miss-index <entry-index>]",
  .function = l2_rw_interface_cli_fn,
};
/* *INDENT-ON* */

static clib_error_t *
l2_rw_show_interfaces_cli_fn (vlib_main_t * vm,
			      unformat_input_t * input,
			      vlib_cli_command_t * cmd)
{
  l2_rw_main_t *rw = &l2_rw_main;
  if (clib_bitmap_count_set_bits (rw->configs_bitmap) == 0)
    vlib_cli_output (vm, "No interface is currently using l2 rewrite\n");

  uword i;
  /* *INDENT-OFF* */
  clib_bitmap_foreach(i, rw->configs_bitmap, {
      vlib_cli_output (vm, "sw_if_index:%d %U\n", i, format_l2_rw_config, &rw->configs[i]);
  });
  /* *INDENT-ON* */
  return 0;
}

/*?
 * Layer 2-Rewrite node uses classify tables to match packets. Then, using
 * the provisioned mask and value, modifies the packet header.
 *
 * @cliexpar
 * @todo This is incomplete. This needs a detailed description and a
 * practical example.
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (l2_rw_show_interfaces_cli, static) = {
  .path = "show l2 rewrite interfaces",
  .short_help =
  "show l2 rewrite interfaces",
  .function = l2_rw_show_interfaces_cli_fn,
};
/* *INDENT-ON* */

static clib_error_t *
l2_rw_show_entries_cli_fn (vlib_main_t * vm,
			   unformat_input_t * input, vlib_cli_command_t * cmd)
{
  l2_rw_main_t *rw = &l2_rw_main;
  l2_rw_entry_t *e;
  if (pool_elts (rw->entries) == 0)
    vlib_cli_output (vm, "No entries\n");

  /* *INDENT-OFF* */
  pool_foreach(e, rw->entries, {
    vlib_cli_output (vm, "%U\n", format_l2_rw_entry, e);
  });
  /* *INDENT-ON* */
  return 0;
}

/*?
 * Layer 2-Rewrite node uses classify tables to match packets. Then, using
 * the provisioned mask and value, modifies the packet header.
 *
 * @cliexpar
 * @todo This is incomplete. This needs a detailed description and a
 * practical example.
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (l2_rw_show_entries_cli, static) = {
  .path = "show l2 rewrite entries",
  .short_help =
  "show l2 rewrite entries",
  .function = l2_rw_show_entries_cli_fn,
};
/* *INDENT-ON* */

static int
l2_rw_enable_disable (u32 bridge_domain, u8 disable)
{
  u32 mask = L2INPUT_FEAT_RW;
  l2input_set_bridge_features (bridge_domain, mask, disable ? 0 : mask);
  return 0;
}

static clib_error_t *
l2_rw_set_cli_fn (vlib_main_t * vm,
		  unformat_input_t * input, vlib_cli_command_t * cmd)
{
  u32 bridge_domain;
  u8 disable = 0;

  if (unformat_check_input (input) == UNFORMAT_END_OF_INPUT ||
      !unformat (input, "%d", &bridge_domain))
    {
      return clib_error_return (0, "You must specify a bridge domain");
    }

  if (unformat_check_input (input) != UNFORMAT_END_OF_INPUT &&
      unformat (input, "disable"))
    {
      disable = 1;
    }

  if (l2_rw_enable_disable (bridge_domain, disable))
    return clib_error_return (0, "Could not enable or disable rewrite");

  return 0;
}

/*?
 * Layer 2-Rewrite node uses classify tables to match packets. Then, using
 * the provisioned mask and value, modfies the packet header.
 *
 * @cliexpar
 * @todo This is incomplete. This needs a detailed description and a
 * practical example.
?*/
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (l2_rw_set_cli, static) = {
  .path = "set bridge-domain rewrite",
  .short_help =
  "set bridge-domain rewrite <bridge-domain> [disable]",
  .function = l2_rw_set_cli_fn,
};
/* *INDENT-ON* */

static clib_error_t *
l2_rw_init (vlib_main_t * vm)
{
  l2_rw_main_t *rw = &l2_rw_main;
  rw->configs = 0;
  rw->entries = 0;
  clib_bitmap_alloc (rw->configs_bitmap, 1);
  feat_bitmap_init_next_nodes (vm,
			       l2_rw_node.index,
			       L2INPUT_N_FEAT,
			       l2input_get_feat_names (),
			       rw->feat_next_node_index);
  return 0;
}

VLIB_INIT_FUNCTION (l2_rw_init);

enum
{
  L2_RW_NEXT_DROP,
  L2_RW_N_NEXT,
};

#define foreach_l2_rw_error               \
_(UNKNOWN, "Unknown error")

typedef enum
{
#define _(sym,str) L2_RW_ERROR_##sym,
  foreach_l2_rw_error
#undef _
    L2_RW_N_ERROR,
} l2_rw_error_t;

static char *l2_rw_error_strings[] = {
#define _(sym,string) string,
  foreach_l2_rw_error
#undef _
};

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (l2_rw_node) = {
  .name = "l2-rw",
  .vector_size = sizeof (u32),
  .format_trace = format_l2_rw_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = ARRAY_LEN(l2_rw_error_strings),
  .error_strings = l2_rw_error_strings,
  .runtime_data_bytes = 0,
  .n_next_nodes = L2_RW_N_NEXT,
  .next_nodes = { [L2_RW_NEXT_DROP]  = "error-drop"},
};
/* *INDENT-ON* */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */
='n3568' href='#n3568'>3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669
/*
 * Copyright (c) 2017-2019 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this
 * 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 <stdio.h>
#include <stdlib.h>
#include <vcl/vppcom.h>
#include <vcl/vcl_debug.h>
#include <vcl/vcl_private.h>
#include <svm/fifo_segment.h>

__thread uword __vcl_worker_index = ~0;

static int
vcl_wait_for_segment (u64 segment_handle)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  u32 wait_for_seconds = 10, segment_index;
  f64 timeout;

  if (segment_handle == VCL_INVALID_SEGMENT_HANDLE)
    return 0;

  timeout = clib_time_now (&wrk->clib_time) + wait_for_seconds;
  while (clib_time_now (&wrk->clib_time) < timeout)
    {
      segment_index = vcl_segment_table_lookup (segment_handle);
      if (segment_index != VCL_INVALID_SEGMENT_INDEX)
	return 0;
      usleep (10);
    }
  return 1;
}

static inline int
vcl_mq_dequeue_batch (vcl_worker_t * wrk, svm_msg_q_t * mq, u32 n_max_msg)
{
  svm_msg_q_msg_t *msg;
  u32 n_msgs;
  int i;

  n_msgs = clib_min (svm_msg_q_size (mq), n_max_msg);
  for (i = 0; i < n_msgs; i++)
    {
      vec_add2 (wrk->mq_msg_vector, msg, 1);
      svm_msg_q_sub_w_lock (mq, msg);
    }
  return n_msgs;
}

const char *
vppcom_session_state_str (vcl_session_state_t state)
{
  char *st;

  switch (state)
    {
    case STATE_START:
      st = "STATE_START";
      break;

    case STATE_CONNECT:
      st = "STATE_CONNECT";
      break;

    case STATE_LISTEN:
      st = "STATE_LISTEN";
      break;

    case STATE_ACCEPT:
      st = "STATE_ACCEPT";
      break;

    case STATE_VPP_CLOSING:
      st = "STATE_VPP_CLOSING";
      break;

    case STATE_DISCONNECT:
      st = "STATE_DISCONNECT";
      break;

    case STATE_FAILED:
      st = "STATE_FAILED";
      break;

    case STATE_UPDATED:
      st = "STATE_UPDATED";
      break;

    case STATE_LISTEN_NO_MQ:
      st = "STATE_LISTEN_NO_MQ";
      break;

    default:
      st = "UNKNOWN_STATE";
      break;
    }

  return st;
}

u8 *
format_ip4_address (u8 * s, va_list * args)
{
  u8 *a = va_arg (*args, u8 *);
  return format (s, "%d.%d.%d.%d", a[0], a[1], a[2], a[3]);
}

u8 *
format_ip6_address (u8 * s, va_list * args)
{
  ip6_address_t *a = va_arg (*args, ip6_address_t *);
  u32 i, i_max_n_zero, max_n_zeros, i_first_zero, n_zeros, last_double_colon;

  i_max_n_zero = ARRAY_LEN (a->as_u16);
  max_n_zeros = 0;
  i_first_zero = i_max_n_zero;
  n_zeros = 0;
  for (i = 0; i < ARRAY_LEN (a->as_u16); i++)
    {
      u32 is_zero = a->as_u16[i] == 0;
      if (is_zero && i_first_zero >= ARRAY_LEN (a->as_u16))
	{
	  i_first_zero = i;
	  n_zeros = 0;
	}
      n_zeros += is_zero;
      if ((!is_zero && n_zeros > max_n_zeros)
	  || (i + 1 >= ARRAY_LEN (a->as_u16) && n_zeros > max_n_zeros))
	{
	  i_max_n_zero = i_first_zero;
	  max_n_zeros = n_zeros;
	  i_first_zero = ARRAY_LEN (a->as_u16);
	  n_zeros = 0;
	}
    }

  last_double_colon = 0;
  for (i = 0; i < ARRAY_LEN (a->as_u16); i++)
    {
      if (i == i_max_n_zero && max_n_zeros > 1)
	{
	  s = format (s, "::");
	  i += max_n_zeros - 1;
	  last_double_colon = 1;
	}
      else
	{
	  s = format (s, "%s%x",
		      (last_double_colon || i == 0) ? "" : ":",
		      clib_net_to_host_u16 (a->as_u16[i]));
	  last_double_colon = 0;
	}
    }

  return s;
}

/* Format an IP46 address. */
u8 *
format_ip46_address (u8 * s, va_list * args)
{
  ip46_address_t *ip46 = va_arg (*args, ip46_address_t *);
  ip46_type_t type = va_arg (*args, ip46_type_t);
  int is_ip4 = 1;

  switch (type)
    {
    case IP46_TYPE_ANY:
      is_ip4 = ip46_address_is_ip4 (ip46);
      break;
    case IP46_TYPE_IP4:
      is_ip4 = 1;
      break;
    case IP46_TYPE_IP6:
      is_ip4 = 0;
      break;
    }

  return is_ip4 ?
    format (s, "%U", format_ip4_address, &ip46->ip4) :
    format (s, "%U", format_ip6_address, &ip46->ip6);
}

/*
 * VPPCOM Utility Functions
 */

static void
vcl_send_session_listen (vcl_worker_t * wrk, vcl_session_t * s)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_listen_msg_t *mp;
  svm_msg_q_t *mq;

  mq = vcl_worker_ctrl_mq (wrk);
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_LISTEN);
  mp = (session_listen_msg_t *) app_evt->evt->data;
  memset (mp, 0, sizeof (*mp));
  mp->client_index = wrk->my_client_index;
  mp->context = s->session_index;
  mp->wrk_index = wrk->vpp_wrk_index;
  mp->is_ip4 = s->transport.is_ip4;
  clib_memcpy_fast (&mp->ip, &s->transport.lcl_ip, sizeof (mp->ip));
  mp->port = s->transport.lcl_port;
  mp->proto = s->session_type;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

static void
vcl_send_session_connect (vcl_worker_t * wrk, vcl_session_t * s)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_connect_msg_t *mp;
  svm_msg_q_t *mq;

  mq = vcl_worker_ctrl_mq (wrk);
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_CONNECT);
  mp = (session_connect_msg_t *) app_evt->evt->data;
  memset (mp, 0, sizeof (*mp));
  mp->client_index = wrk->my_client_index;
  mp->context = s->session_index;
  mp->wrk_index = wrk->vpp_wrk_index;
  mp->is_ip4 = s->transport.is_ip4;
  mp->parent_handle = s->parent_handle;
  clib_memcpy_fast (&mp->ip, &s->transport.rmt_ip, sizeof (mp->ip));
  clib_memcpy_fast (&mp->lcl_ip, &s->transport.lcl_ip, sizeof (mp->lcl_ip));
  mp->port = s->transport.rmt_port;
  mp->proto = s->session_type;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

void
vcl_send_session_unlisten (vcl_worker_t * wrk, vcl_session_t * s)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_unlisten_msg_t *mp;
  svm_msg_q_t *mq;

  mq = vcl_worker_ctrl_mq (wrk);
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_UNLISTEN);
  mp = (session_unlisten_msg_t *) app_evt->evt->data;
  memset (mp, 0, sizeof (*mp));
  mp->client_index = wrk->my_client_index;
  mp->wrk_index = wrk->vpp_wrk_index;
  mp->handle = s->vpp_handle;
  mp->context = wrk->wrk_index;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

static void
vcl_send_session_disconnect (vcl_worker_t * wrk, vcl_session_t * s)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_disconnect_msg_t *mp;
  svm_msg_q_t *mq;

  /* Send to thread that owns the session */
  mq = s->vpp_evt_q;
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_DISCONNECT);
  mp = (session_disconnect_msg_t *) app_evt->evt->data;
  memset (mp, 0, sizeof (*mp));
  mp->client_index = wrk->my_client_index;
  mp->handle = s->vpp_handle;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

static void
vcl_send_app_detach (vcl_worker_t * wrk)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_app_detach_msg_t *mp;
  svm_msg_q_t *mq;

  mq = vcl_worker_ctrl_mq (wrk);
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_APP_DETACH);
  mp = (session_app_detach_msg_t *) app_evt->evt->data;
  memset (mp, 0, sizeof (*mp));
  mp->client_index = wrk->my_client_index;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

static void
vcl_send_session_accepted_reply (svm_msg_q_t * mq, u32 context,
				 session_handle_t handle, int retval)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_accepted_reply_msg_t *rmp;
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_ACCEPTED_REPLY);
  rmp = (session_accepted_reply_msg_t *) app_evt->evt->data;
  rmp->handle = handle;
  rmp->context = context;
  rmp->retval = retval;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

static void
vcl_send_session_disconnected_reply (svm_msg_q_t * mq, u32 context,
				     session_handle_t handle, int retval)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_disconnected_reply_msg_t *rmp;
  app_alloc_ctrl_evt_to_vpp (mq, app_evt,
			     SESSION_CTRL_EVT_DISCONNECTED_REPLY);
  rmp = (session_disconnected_reply_msg_t *) app_evt->evt->data;
  rmp->handle = handle;
  rmp->context = context;
  rmp->retval = retval;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

static void
vcl_send_session_reset_reply (svm_msg_q_t * mq, u32 context,
			      session_handle_t handle, int retval)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_reset_reply_msg_t *rmp;
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_RESET_REPLY);
  rmp = (session_reset_reply_msg_t *) app_evt->evt->data;
  rmp->handle = handle;
  rmp->context = context;
  rmp->retval = retval;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

void
vcl_send_session_worker_update (vcl_worker_t * wrk, vcl_session_t * s,
				u32 wrk_index)
{
  app_session_evt_t _app_evt, *app_evt = &_app_evt;
  session_worker_update_msg_t *mp;
  svm_msg_q_t *mq;

  mq = vcl_session_vpp_evt_q (wrk, s);
  app_alloc_ctrl_evt_to_vpp (mq, app_evt, SESSION_CTRL_EVT_WORKER_UPDATE);
  mp = (session_worker_update_msg_t *) app_evt->evt->data;
  mp->client_index = wrk->my_client_index;
  mp->handle = s->vpp_handle;
  mp->req_wrk_index = wrk->vpp_wrk_index;
  mp->wrk_index = wrk_index;
  app_send_ctrl_evt_to_vpp (mq, app_evt);
}

static u32
vcl_session_accepted_handler (vcl_worker_t * wrk, session_accepted_msg_t * mp,
			      u32 ls_index)
{
  vcl_session_t *session, *listen_session;
  svm_fifo_t *rx_fifo, *tx_fifo;
  u32 vpp_wrk_index;
  svm_msg_q_t *evt_q;

  session = vcl_session_alloc (wrk);

  listen_session = vcl_session_get (wrk, ls_index);
  if (listen_session->vpp_handle != mp->listener_handle)
    {
      VDBG (0, "ERROR: listener handle %lu does not match session %u",
	    mp->listener_handle, ls_index);
      goto error;
    }

  if (vcl_wait_for_segment (mp->segment_handle))
    {
      VDBG (0, "ERROR: segment for session %u couldn't be mounted!",
	    session->session_index);
      goto error;
    }

  rx_fifo = uword_to_pointer (mp->server_rx_fifo, svm_fifo_t *);
  tx_fifo = uword_to_pointer (mp->server_tx_fifo, svm_fifo_t *);
  session->vpp_evt_q = uword_to_pointer (mp->vpp_event_queue_address,
					 svm_msg_q_t *);
  rx_fifo->client_session_index = session->session_index;
  tx_fifo->client_session_index = session->session_index;
  rx_fifo->client_thread_index = vcl_get_worker_index ();
  tx_fifo->client_thread_index = vcl_get_worker_index ();
  vpp_wrk_index = tx_fifo->master_thread_index;
  vec_validate (wrk->vpp_event_queues, vpp_wrk_index);
  wrk->vpp_event_queues[vpp_wrk_index] = session->vpp_evt_q;

  session->vpp_handle = mp->handle;
  session->vpp_thread_index = rx_fifo->master_thread_index;
  session->rx_fifo = rx_fifo;
  session->tx_fifo = tx_fifo;

  session->session_state = STATE_ACCEPT;
  session->transport.rmt_port = mp->rmt.port;
  session->transport.is_ip4 = mp->rmt.is_ip4;
  clib_memcpy_fast (&session->transport.rmt_ip, &mp->rmt.ip,
		    sizeof (ip46_address_t));

  vcl_session_table_add_vpp_handle (wrk, mp->handle, session->session_index);
  session->transport.lcl_port = listen_session->transport.lcl_port;
  session->transport.lcl_ip = listen_session->transport.lcl_ip;
  session->session_type = listen_session->session_type;
  session->is_dgram = vcl_proto_is_dgram (session->session_type);
  session->listener_index = listen_session->session_index;
  listen_session->n_accepted_sessions++;

  VDBG (1, "session %u [0x%llx]: client accept request from %s address %U"
	" port %d queue %p!", session->session_index, mp->handle,
	mp->rmt.is_ip4 ? "IPv4" : "IPv6", format_ip46_address, &mp->rmt.ip,
	mp->rmt.is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
	clib_net_to_host_u16 (mp->rmt.port), session->vpp_evt_q);
  vcl_evt (VCL_EVT_ACCEPT, session, listen_session, session_index);

  vcl_send_session_accepted_reply (session->vpp_evt_q, mp->context,
				   session->vpp_handle, 0);

  return session->session_index;

error:
  evt_q = uword_to_pointer (mp->vpp_event_queue_address, svm_msg_q_t *);
  vcl_send_session_accepted_reply (evt_q, mp->context, mp->handle,
				   VNET_API_ERROR_INVALID_ARGUMENT);
  vcl_session_free (wrk, session);
  return VCL_INVALID_SESSION_INDEX;
}

static u32
vcl_session_connected_handler (vcl_worker_t * wrk,
			       session_connected_msg_t * mp)
{
  u32 session_index, vpp_wrk_index;
  svm_fifo_t *rx_fifo, *tx_fifo;
  vcl_session_t *session = 0;

  session_index = mp->context;
  session = vcl_session_get (wrk, session_index);
  if (!session)
    {
      VDBG (0, "ERROR: vpp handle 0x%llx has no session index (%u)!",
	    mp->handle, session_index);
      return VCL_INVALID_SESSION_INDEX;
    }
  if (mp->retval)
    {
      VDBG (0, "ERROR: session index %u: connect failed! %U",
	    session_index, format_api_error, ntohl (mp->retval));
      session->session_state = STATE_FAILED | STATE_DISCONNECT;
      session->vpp_handle = mp->handle;
      return session_index;
    }

  session->vpp_handle = mp->handle;
  session->vpp_evt_q = uword_to_pointer (mp->vpp_event_queue_address,
					 svm_msg_q_t *);
  rx_fifo = uword_to_pointer (mp->server_rx_fifo, svm_fifo_t *);
  tx_fifo = uword_to_pointer (mp->server_tx_fifo, svm_fifo_t *);
  if (vcl_wait_for_segment (mp->segment_handle))
    {
      VDBG (0, "segment for session %u couldn't be mounted!",
	    session->session_index);
      session->session_state = STATE_FAILED | STATE_DISCONNECT;
      vcl_send_session_disconnect (wrk, session);
      return session_index;
    }

  rx_fifo->client_session_index = session_index;
  tx_fifo->client_session_index = session_index;
  rx_fifo->client_thread_index = vcl_get_worker_index ();
  tx_fifo->client_thread_index = vcl_get_worker_index ();

  vpp_wrk_index = tx_fifo->master_thread_index;
  vec_validate (wrk->vpp_event_queues, vpp_wrk_index);
  wrk->vpp_event_queues[vpp_wrk_index] = session->vpp_evt_q;

  if (mp->ct_rx_fifo)
    {
      session->ct_rx_fifo = uword_to_pointer (mp->ct_rx_fifo, svm_fifo_t *);
      session->ct_tx_fifo = uword_to_pointer (mp->ct_tx_fifo, svm_fifo_t *);
      if (vcl_wait_for_segment (mp->ct_segment_handle))
	{
	  VDBG (0, "ct segment for session %u couldn't be mounted!",
		session->session_index);
	  session->session_state = STATE_FAILED | STATE_DISCONNECT;
	  vcl_send_session_disconnect (wrk, session);
	  return session_index;
	}
    }

  session->rx_fifo = rx_fifo;
  session->tx_fifo = tx_fifo;
  session->vpp_thread_index = rx_fifo->master_thread_index;
  session->transport.is_ip4 = mp->lcl.is_ip4;
  clib_memcpy_fast (&session->transport.lcl_ip, &mp->lcl.ip,
		    sizeof (session->transport.lcl_ip));
  session->transport.lcl_port = mp->lcl.port;
  session->session_state = STATE_CONNECT;

  /* Add it to lookup table */
  vcl_session_table_add_vpp_handle (wrk, mp->handle, session_index);

  VDBG (1, "session %u [0x%llx] connected! rx_fifo %p, refcnt %d, tx_fifo %p,"
	" refcnt %d", session_index, mp->handle, session->rx_fifo,
	session->rx_fifo->refcnt, session->tx_fifo, session->tx_fifo->refcnt);

  return session_index;
}

static int
vcl_flag_accepted_session (vcl_session_t * session, u64 handle, u32 flags)
{
  vcl_session_msg_t *accepted_msg;
  int i;

  for (i = 0; i < vec_len (session->accept_evts_fifo); i++)
    {
      accepted_msg = &session->accept_evts_fifo[i];
      if (accepted_msg->accepted_msg.handle == handle)
	{
	  accepted_msg->flags |= flags;
	  return 1;
	}
    }
  return 0;
}

static u32
vcl_session_reset_handler (vcl_worker_t * wrk,
			   session_reset_msg_t * reset_msg)
{
  vcl_session_t *session;
  u32 sid;

  sid = vcl_session_index_from_vpp_handle (wrk, reset_msg->handle);
  session = vcl_session_get (wrk, sid);
  if (!session)
    {
      VDBG (0, "request to reset unknown handle 0x%llx", reset_msg->handle);
      return VCL_INVALID_SESSION_INDEX;
    }

  /* Caught a reset before actually accepting the session */
  if (session->session_state == STATE_LISTEN)
    {

      if (!vcl_flag_accepted_session (session, reset_msg->handle,
				      VCL_ACCEPTED_F_RESET))
	VDBG (0, "session was not accepted!");
      return VCL_INVALID_SESSION_INDEX;
    }

  session->session_state = STATE_DISCONNECT;
  VDBG (0, "reset session %u [0x%llx]", sid, reset_msg->handle);
  return sid;
}

static u32
vcl_session_bound_handler (vcl_worker_t * wrk, session_bound_msg_t * mp)
{
  vcl_session_t *session;
  u32 sid = mp->context;

  session = vcl_session_get (wrk, sid);
  if (mp->retval)
    {
      VERR ("session %u [0x%llx]: bind failed: %U", sid, mp->handle,
	    format_api_error, mp->retval);
      if (session)
	{
	  session->session_state = STATE_FAILED;
	  session->vpp_handle = mp->handle;
	  return sid;
	}
      else
	{
	  VDBG (0, "ERROR: session %u [0x%llx]: Invalid session index!",
		sid, mp->handle);
	  return VCL_INVALID_SESSION_INDEX;
	}
    }

  session->vpp_handle = mp->handle;
  session->transport.is_ip4 = mp->lcl_is_ip4;
  clib_memcpy_fast (&session->transport.lcl_ip, mp->lcl_ip,
		    sizeof (ip46_address_t));
  session->transport.lcl_port = mp->lcl_port;
  vcl_session_table_add_listener (wrk, mp->handle, sid);
  session->session_state = STATE_LISTEN;

  session->vpp_evt_q = uword_to_pointer (mp->vpp_evt_q, svm_msg_q_t *);
  vec_validate (wrk->vpp_event_queues, 0);
  wrk->vpp_event_queues[0] = session->vpp_evt_q;

  if (session->is_dgram)
    {
      svm_fifo_t *rx_fifo, *tx_fifo;
      session->vpp_evt_q = uword_to_pointer (mp->vpp_evt_q, svm_msg_q_t *);
      rx_fifo = uword_to_pointer (mp->rx_fifo, svm_fifo_t *);
      rx_fifo->client_session_index = sid;
      tx_fifo = uword_to_pointer (mp->tx_fifo, svm_fifo_t *);
      tx_fifo->client_session_index = sid;
      session->rx_fifo = rx_fifo;
      session->tx_fifo = tx_fifo;
    }

  VDBG (0, "session %u [0x%llx]: listen succeeded!", sid, mp->handle);
  return sid;
}

static void
vcl_session_unlisten_reply_handler (vcl_worker_t * wrk, void *data)
{
  session_unlisten_reply_msg_t *mp = (session_unlisten_reply_msg_t *) data;
  vcl_session_t *s;

  s = vcl_session_get_w_vpp_handle (wrk, mp->handle);
  if (!s || s->session_state != STATE_DISCONNECT)
    {
      VDBG (0, "Unlisten reply with wrong handle %llx", mp->handle);
      return;
    }

  if (mp->retval)
    VDBG (0, "ERROR: session %u [0xllx]: unlisten failed: %U",
	  s->session_index, mp->handle, format_api_error, ntohl (mp->retval));

  if (mp->context != wrk->wrk_index)
    VDBG (0, "wrong context");

  vcl_session_table_del_vpp_handle (wrk, mp->handle);
  vcl_session_free (wrk, s);
}

static vcl_session_t *
vcl_session_accepted (vcl_worker_t * wrk, session_accepted_msg_t * msg)
{
  vcl_session_msg_t *vcl_msg;
  vcl_session_t *session;

  session = vcl_session_get_w_vpp_handle (wrk, msg->handle);
  if (PREDICT_FALSE (session != 0))
    VWRN ("session overlap handle %lu state %u!", msg->handle,
	  session->session_state);

  session = vcl_session_table_lookup_listener (wrk, msg->listener_handle);
  if (!session)
    {
      VERR ("couldn't find listen session: listener handle %llx",
	    msg->listener_handle);
      return 0;
    }

  clib_fifo_add2 (session->accept_evts_fifo, vcl_msg);
  vcl_msg->accepted_msg = *msg;
  /* Session handle points to listener until fully accepted by app */
  vcl_session_table_add_vpp_handle (wrk, msg->handle, session->session_index);

  return session;
}

static vcl_session_t *
vcl_session_disconnected_handler (vcl_worker_t * wrk,
				  session_disconnected_msg_t * msg)
{
  vcl_session_t *session;

  session = vcl_session_get_w_vpp_handle (wrk, msg->handle);
  if (!session)
    {
      VDBG (0, "request to disconnect unknown handle 0x%llx", msg->handle);
      return 0;
    }

  /* Caught a disconnect before actually accepting the session */
  if (session->session_state == STATE_LISTEN)
    {
      if (!vcl_flag_accepted_session (session, msg->handle,
				      VCL_ACCEPTED_F_CLOSED))
	VDBG (0, "session was not accepted!");
      return 0;
    }

  session->session_state = STATE_VPP_CLOSING;
  return session;
}

static void
vcl_session_req_worker_update_handler (vcl_worker_t * wrk, void *data)
{
  session_req_worker_update_msg_t *msg;
  vcl_session_t *s;

  msg = (session_req_worker_update_msg_t *) data;
  s = vcl_session_get_w_vpp_handle (wrk, msg->session_handle);
  if (!s)
    return;

  vec_add1 (wrk->pending_session_wrk_updates, s->session_index);
}

static void
vcl_session_worker_update_reply_handler (vcl_worker_t * wrk, void *data)
{
  session_worker_update_reply_msg_t *msg;
  vcl_session_t *s;

  msg = (session_worker_update_reply_msg_t *) data;
  s = vcl_session_get_w_vpp_handle (wrk, msg->handle);
  if (!s)
    {
      VDBG (0, "unknown handle 0x%llx", msg->handle);
      return;
    }
  if (vcl_wait_for_segment (msg->segment_handle))
    {
      clib_warning ("segment for session %u couldn't be mounted!",
		    s->session_index);
      return;
    }

  if (s->rx_fifo)
    {
      s->rx_fifo = uword_to_pointer (msg->rx_fifo, svm_fifo_t *);
      s->tx_fifo = uword_to_pointer (msg->tx_fifo, svm_fifo_t *);
      s->rx_fifo->client_session_index = s->session_index;
      s->tx_fifo->client_session_index = s->session_index;
      s->rx_fifo->client_thread_index = wrk->wrk_index;
      s->tx_fifo->client_thread_index = wrk->wrk_index;
    }
  s->session_state = STATE_UPDATED;

  VDBG (0, "session %u[0x%llx] moved to worker %u", s->session_index,
	s->vpp_handle, wrk->wrk_index);
}

static int
vcl_handle_mq_event (vcl_worker_t * wrk, session_event_t * e)
{
  session_disconnected_msg_t *disconnected_msg;
  vcl_session_t *session;

  switch (e->event_type)
    {
    case SESSION_IO_EVT_RX:
    case SESSION_IO_EVT_TX:
      session = vcl_session_get (wrk, e->session_index);
      if (!session || !(session->session_state & STATE_OPEN))
	break;
      vec_add1 (wrk->unhandled_evts_vector, *e);
      break;
    case SESSION_CTRL_EVT_ACCEPTED:
      vcl_session_accepted (wrk, (session_accepted_msg_t *) e->data);
      break;
    case SESSION_CTRL_EVT_CONNECTED:
      vcl_session_connected_handler (wrk,
				     (session_connected_msg_t *) e->data);
      break;
    case SESSION_CTRL_EVT_DISCONNECTED:
      disconnected_msg = (session_disconnected_msg_t *) e->data;
      session = vcl_session_disconnected_handler (wrk, disconnected_msg);
      if (!session)
	break;
      VDBG (0, "disconnected session %u [0x%llx]", session->session_index,
	    session->vpp_handle);
      break;
    case SESSION_CTRL_EVT_RESET:
      vcl_session_reset_handler (wrk, (session_reset_msg_t *) e->data);
      break;
    case SESSION_CTRL_EVT_BOUND:
      vcl_session_bound_handler (wrk, (session_bound_msg_t *) e->data);
      break;
    case SESSION_CTRL_EVT_UNLISTEN_REPLY:
      vcl_session_unlisten_reply_handler (wrk, e->data);
      break;
    case SESSION_CTRL_EVT_REQ_WORKER_UPDATE:
      vcl_session_req_worker_update_handler (wrk, e->data);
      break;
    case SESSION_CTRL_EVT_WORKER_UPDATE_REPLY:
      vcl_session_worker_update_reply_handler (wrk, e->data);
      break;
    default:
      clib_warning ("unhandled %u", e->event_type);
    }
  return VPPCOM_OK;
}

static int
vppcom_wait_for_session_state_change (u32 session_index,
				      vcl_session_state_t state,
				      f64 wait_for_time)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  f64 timeout = clib_time_now (&wrk->clib_time) + wait_for_time;
  vcl_session_t *volatile session;
  svm_msg_q_msg_t msg;
  session_event_t *e;

  do
    {
      session = vcl_session_get (wrk, session_index);
      if (PREDICT_FALSE (!session))
	{
	  return VPPCOM_EBADFD;
	}
      if (session->session_state & state)
	{
	  return VPPCOM_OK;
	}
      if (session->session_state & STATE_FAILED)
	{
	  return VPPCOM_ECONNREFUSED;
	}

      if (svm_msg_q_sub (wrk->app_event_queue, &msg, SVM_Q_NOWAIT, 0))
	{
	  usleep (100);
	  continue;
	}
      e = svm_msg_q_msg_data (wrk->app_event_queue, &msg);
      vcl_handle_mq_event (wrk, e);
      svm_msg_q_free_msg (wrk->app_event_queue, &msg);
    }
  while (clib_time_now (&wrk->clib_time) < timeout);

  VDBG (0, "timeout waiting for state 0x%x (%s)", state,
	vppcom_session_state_str (state));
  vcl_evt (VCL_EVT_SESSION_TIMEOUT, session, session_state);

  return VPPCOM_ETIMEDOUT;
}

static void
vcl_handle_pending_wrk_updates (vcl_worker_t * wrk)
{
  vcl_session_state_t state;
  vcl_session_t *s;
  u32 *sip;

  if (PREDICT_TRUE (vec_len (wrk->pending_session_wrk_updates) == 0))
    return;

  vec_foreach (sip, wrk->pending_session_wrk_updates)
  {
    s = vcl_session_get (wrk, *sip);
    vcl_send_session_worker_update (wrk, s, wrk->wrk_index);
    state = s->session_state;
    vppcom_wait_for_session_state_change (s->session_index, STATE_UPDATED, 5);
    s->session_state = state;
  }
  vec_reset_length (wrk->pending_session_wrk_updates);
}

void
vcl_flush_mq_events (void)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  svm_msg_q_msg_t *msg;
  session_event_t *e;
  svm_msg_q_t *mq;
  int i;

  mq = wrk->app_event_queue;
  svm_msg_q_lock (mq);
  vcl_mq_dequeue_batch (wrk, mq, ~0);
  svm_msg_q_unlock (mq);

  for (i = 0; i < vec_len (wrk->mq_msg_vector); i++)
    {
      msg = vec_elt_at_index (wrk->mq_msg_vector, i);
      e = svm_msg_q_msg_data (mq, msg);
      vcl_handle_mq_event (wrk, e);
      svm_msg_q_free_msg (mq, msg);
    }
  vec_reset_length (wrk->mq_msg_vector);
  vcl_handle_pending_wrk_updates (wrk);
}

static int
vppcom_app_session_enable (void)
{
  int rv;

  if (vcm->app_state != STATE_APP_ENABLED)
    {
      vppcom_send_session_enable_disable (1 /* is_enabled == TRUE */ );
      rv = vcl_wait_for_app_state_change (STATE_APP_ENABLED);
      if (PREDICT_FALSE (rv))
	{
	  VDBG (0, "application session enable timed out! returning %d (%s)",
		rv, vppcom_retval_str (rv));
	  return rv;
	}
    }
  return VPPCOM_OK;
}

static int
vppcom_app_attach (void)
{
  int rv;

  vppcom_app_send_attach ();
  rv = vcl_wait_for_app_state_change (STATE_APP_ATTACHED);
  if (PREDICT_FALSE (rv))
    {
      VDBG (0, "application attach timed out! returning %d (%s)", rv,
	    vppcom_retval_str (rv));
      return rv;
    }

  return VPPCOM_OK;
}

static int
vppcom_session_unbind (u32 session_handle)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  session_accepted_msg_t *accepted_msg;
  vcl_session_t *session = 0;
  vcl_session_msg_t *evt;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;

  /* Flush pending accept events, if any */
  while (clib_fifo_elts (session->accept_evts_fifo))
    {
      clib_fifo_sub2 (session->accept_evts_fifo, evt);
      accepted_msg = &evt->accepted_msg;
      vcl_session_table_del_vpp_handle (wrk, accepted_msg->handle);
      vcl_send_session_accepted_reply (session->vpp_evt_q,
				       accepted_msg->context,
				       session->vpp_handle, -1);
    }
  clib_fifo_free (session->accept_evts_fifo);

  vcl_send_session_unlisten (wrk, session);

  VDBG (1, "session %u [0x%llx]: sending unbind!", session->session_index,
	session->vpp_handle);
  vcl_evt (VCL_EVT_UNBIND, session);

  session->vpp_handle = ~0;
  session->session_state = STATE_DISCONNECT;

  return VPPCOM_OK;
}

static int
vppcom_session_disconnect (u32 session_handle)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  svm_msg_q_t *vpp_evt_q;
  vcl_session_t *session, *listen_session;
  vcl_session_state_t state;
  u64 vpp_handle;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;

  vpp_handle = session->vpp_handle;
  state = session->session_state;

  VDBG (1, "session %u [0x%llx] state 0x%x (%s)", session->session_index,
	vpp_handle, state, vppcom_session_state_str (state));

  if (PREDICT_FALSE (state & STATE_LISTEN))
    {
      VDBG (0, "ERROR: Cannot disconnect a listen socket!");
      return VPPCOM_EBADFD;
    }

  if (state & STATE_VPP_CLOSING)
    {
      vpp_evt_q = vcl_session_vpp_evt_q (wrk, session);
      vcl_send_session_disconnected_reply (vpp_evt_q, wrk->my_client_index,
					   vpp_handle, 0);
      VDBG (1, "session %u [0x%llx]: sending disconnect REPLY...",
	    session->session_index, vpp_handle);
    }
  else
    {
      VDBG (1, "session %u [0x%llx]: sending disconnect...",
	    session->session_index, vpp_handle);
      vcl_send_session_disconnect (wrk, session);
    }

  if (session->listener_index != VCL_INVALID_SESSION_INDEX)
    {
      listen_session = vcl_session_get (wrk, session->listener_index);
      listen_session->n_accepted_sessions--;
    }

  return VPPCOM_OK;
}

/**
 * Handle app exit
 *
 * Notify vpp of the disconnect and mark the worker as free. If we're the
 * last worker, do a full cleanup otherwise, since we're probably a forked
 * child, avoid syscalls as much as possible. We might've lost privileges.
 */
void
vppcom_app_exit (void)
{
  if (!pool_elts (vcm->workers))
    return;
  vcl_worker_cleanup (vcl_worker_get_current (), 1 /* notify vpp */ );
  vcl_set_worker_index (~0);
  vcl_elog_stop (vcm);
  if (vec_len (vcm->workers) == 1)
    vppcom_disconnect_from_vpp ();
  else
    vl_client_send_disconnect (1 /* vpp should cleanup */ );
}

/*
 * VPPCOM Public API functions
 */
int
vppcom_app_create (char *app_name)
{
  vppcom_cfg_t *vcl_cfg = &vcm->cfg;
  int rv;

  if (vcm->is_init)
    {
      VDBG (1, "already initialized");
      return VPPCOM_EEXIST;
    }

  vcm->is_init = 1;
  vppcom_cfg (&vcm->cfg);
  vcl_cfg = &vcm->cfg;

  vcm->main_cpu = pthread_self ();
  vcm->main_pid = getpid ();
  vcm->app_name = format (0, "%s", app_name);
  vppcom_init_error_string_table ();
  fifo_segment_main_init (&vcm->segment_main, vcl_cfg->segment_baseva,
			  20 /* timeout in secs */ );
  pool_alloc (vcm->workers, vcl_cfg->max_workers);
  clib_spinlock_init (&vcm->workers_lock);
  clib_rwlock_init (&vcm->segment_table_lock);
  atexit (vppcom_app_exit);

  /* Allocate default worker */
  vcl_worker_alloc_and_init ();

  /* API hookup and connect to VPP */
  vppcom_api_hookup ();
  vcl_elog_init (vcm);
  vcm->app_state = STATE_APP_START;
  rv = vppcom_connect_to_vpp (app_name);
  if (rv)
    {
      VERR ("couldn't connect to VPP!");
      return rv;
    }
  VDBG (0, "sending session enable");
  rv = vppcom_app_session_enable ();
  if (rv)
    {
      VERR ("vppcom_app_session_enable() failed!");
      return rv;
    }

  VDBG (0, "sending app attach");
  rv = vppcom_app_attach ();
  if (rv)
    {
      VERR ("vppcom_app_attach() failed!");
      return rv;
    }

  VDBG (0, "app_name '%s', my_client_index %d (0x%x)", app_name,
	vcm->workers[0].my_client_index, vcm->workers[0].my_client_index);

  return VPPCOM_OK;
}

void
vppcom_app_destroy (void)
{
  int rv;
  f64 orig_app_timeout;

  if (!pool_elts (vcm->workers))
    return;

  vcl_evt (VCL_EVT_DETACH, vcm);

  if (pool_elts (vcm->workers) == 1)
    {
      vcl_send_app_detach (vcl_worker_get_current ());
      orig_app_timeout = vcm->cfg.app_timeout;
      vcm->cfg.app_timeout = 2.0;
      rv = vcl_wait_for_app_state_change (STATE_APP_ENABLED);
      vcm->cfg.app_timeout = orig_app_timeout;
      if (PREDICT_FALSE (rv))
	VDBG (0, "application detach timed out! returning %d (%s)", rv,
	      vppcom_retval_str (rv));
      vec_free (vcm->app_name);
      vcl_worker_cleanup (vcl_worker_get_current (), 0 /* notify vpp */ );
    }
  else
    {
      vcl_worker_cleanup (vcl_worker_get_current (), 1 /* notify vpp */ );
    }

  vcl_set_worker_index (~0);
  vcl_elog_stop (vcm);
  vl_client_disconnect_from_vlib ();
}

int
vppcom_session_create (u8 proto, u8 is_nonblocking)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session;

  session = vcl_session_alloc (wrk);

  session->session_type = proto;
  session->session_state = STATE_START;
  session->vpp_handle = ~0;
  session->is_dgram = vcl_proto_is_dgram (proto);

  if (is_nonblocking)
    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_NONBLOCK);

  vcl_evt (VCL_EVT_CREATE, session, session_type, session->session_state,
	   is_nonblocking, session_index);

  VDBG (0, "created session %u", session->session_index);

  return vcl_session_handle (session);
}

int
vcl_session_cleanup (vcl_worker_t * wrk, vcl_session_t * session,
		     vcl_session_handle_t sh, u8 do_disconnect)
{
  vcl_session_state_t state;
  u32 next_sh, vep_sh;
  int rv = VPPCOM_OK;
  u64 vpp_handle;
  u8 is_vep;

  is_vep = session->is_vep;
  next_sh = session->vep.next_sh;
  vep_sh = session->vep.vep_sh;
  state = session->session_state;
  vpp_handle = session->vpp_handle;

  VDBG (1, "session %u [0x%llx] closing", session->session_index, vpp_handle);

  if (is_vep)
    {
      while (next_sh != ~0)
	{
	  rv = vppcom_epoll_ctl (sh, EPOLL_CTL_DEL, next_sh, 0);
	  if (PREDICT_FALSE (rv < 0))
	    VDBG (0, "vpp handle 0x%llx, sh %u: EPOLL_CTL_DEL vep_idx %u"
		  " failed! rv %d (%s)", vpp_handle, next_sh, vep_sh, rv,
		  vppcom_retval_str (rv));

	  next_sh = session->vep.next_sh;
	}
    }
  else
    {
      if (session->is_vep_session)
	{
	  rv = vppcom_epoll_ctl (vep_sh, EPOLL_CTL_DEL, sh, 0);
	  if (rv < 0)
	    VDBG (0, "session %u [0x%llx]: EPOLL_CTL_DEL vep_idx %u "
		  "failed! rv %d (%s)", session->session_index, vpp_handle,
		  vep_sh, rv, vppcom_retval_str (rv));
	}

      if (!do_disconnect)
	{
	  VDBG (1, "session %u [0x%llx] disconnect skipped",
		session->session_index, vpp_handle);
	  goto cleanup;
	}

      if (state & STATE_LISTEN)
	{
	  rv = vppcom_session_unbind (sh);
	  if (PREDICT_FALSE (rv < 0))
	    VDBG (0, "session %u [0x%llx]: listener unbind failed! "
		  "rv %d (%s)", session->session_index, vpp_handle, rv,
		  vppcom_retval_str (rv));
	  return rv;
	}
      else if ((state & STATE_OPEN)
	       || (vcl_session_is_connectable_listener (wrk, session)))
	{
	  rv = vppcom_session_disconnect (sh);
	  if (PREDICT_FALSE (rv < 0))
	    VDBG (0, "ERROR: session %u [0x%llx]: disconnect failed!"
		  " rv %d (%s)", session->session_index, vpp_handle,
		  rv, vppcom_retval_str (rv));
	}
      else if (state == STATE_DISCONNECT)
	{
	  svm_msg_q_t *mq = vcl_session_vpp_evt_q (wrk, session);
	  vcl_send_session_reset_reply (mq, wrk->my_client_index,
					session->vpp_handle, 0);
	}
    }

  VDBG (0, "session %u [0x%llx] removed", session->session_index, vpp_handle);

cleanup:
  vcl_session_table_del_vpp_handle (wrk, vpp_handle);
  vcl_session_free (wrk, session);
  vcl_evt (VCL_EVT_CLOSE, session, rv);

  return rv;
}

int
vppcom_session_close (uint32_t session_handle)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;
  return vcl_session_cleanup (wrk, session, session_handle,
			      1 /* do_disconnect */ );
}

int
vppcom_session_bind (uint32_t session_handle, vppcom_endpt_t * ep)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session = 0;

  if (!ep || !ep->ip)
    return VPPCOM_EINVAL;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;

  if (session->is_vep)
    {
      VDBG (0, "ERROR: cannot bind to epoll session %u!",
	    session->session_index);
      return VPPCOM_EBADFD;
    }

  session->transport.is_ip4 = ep->is_ip4;
  if (ep->is_ip4)
    clib_memcpy_fast (&session->transport.lcl_ip.ip4, ep->ip,
		      sizeof (ip4_address_t));
  else
    clib_memcpy_fast (&session->transport.lcl_ip.ip6, ep->ip,
		      sizeof (ip6_address_t));
  session->transport.lcl_port = ep->port;

  VDBG (0, "session %u handle %u: binding to local %s address %U port %u, "
	"proto %s", session->session_index, session_handle,
	session->transport.is_ip4 ? "IPv4" : "IPv6",
	format_ip46_address, &session->transport.lcl_ip,
	session->transport.is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
	clib_net_to_host_u16 (session->transport.lcl_port),
	vppcom_proto_str (session->session_type));
  vcl_evt (VCL_EVT_BIND, session);

  if (session->session_type == VPPCOM_PROTO_UDP)
    vppcom_session_listen (session_handle, 10);

  return VPPCOM_OK;
}

int
vppcom_session_listen (uint32_t listen_sh, uint32_t q_len)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *listen_session = 0;
  u64 listen_vpp_handle;
  int rv;

  listen_session = vcl_session_get_w_handle (wrk, listen_sh);
  if (!listen_session || listen_session->is_vep)
    return VPPCOM_EBADFD;

  if (q_len == 0 || q_len == ~0)
    q_len = vcm->cfg.listen_queue_size;

  listen_vpp_handle = listen_session->vpp_handle;
  if (listen_session->session_state & STATE_LISTEN)
    {
      VDBG (0, "session %u [0x%llx]: already in listen state!",
	    listen_sh, listen_vpp_handle);
      return VPPCOM_OK;
    }

  VDBG (0, "session %u: sending vpp listen request...", listen_sh);

  /*
   * Send listen request to vpp and wait for reply
   */
  vcl_send_session_listen (wrk, listen_session);
  rv = vppcom_wait_for_session_state_change (listen_session->session_index,
					     STATE_LISTEN,
					     vcm->cfg.session_timeout);

  if (PREDICT_FALSE (rv))
    {
      listen_session = vcl_session_get_w_handle (wrk, listen_sh);
      VDBG (0, "session %u [0x%llx]: listen failed! returning %d (%s)",
	    listen_sh, listen_session->vpp_handle, rv,
	    vppcom_retval_str (rv));
      return rv;
    }

  return VPPCOM_OK;
}

int
vppcom_session_tls_add_cert (uint32_t session_handle, char *cert,
			     uint32_t cert_len)
{

  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session = 0;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;

  if (cert_len == 0 || cert_len == ~0)
    return VPPCOM_EBADFD;

  /*
   * Send listen request to vpp and wait for reply
   */
  vppcom_send_application_tls_cert_add (session, cert, cert_len);
  vcm->app_state = STATE_APP_ADDING_TLS_DATA;
  vcl_wait_for_app_state_change (STATE_APP_READY);
  return VPPCOM_OK;

}

int
vppcom_session_tls_add_key (uint32_t session_handle, char *key,
			    uint32_t key_len)
{

  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session = 0;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;

  if (key_len == 0 || key_len == ~0)
    return VPPCOM_EBADFD;

  vppcom_send_application_tls_key_add (session, key, key_len);
  vcm->app_state = STATE_APP_ADDING_TLS_DATA;
  vcl_wait_for_app_state_change (STATE_APP_READY);
  return VPPCOM_OK;
}

static int
validate_args_session_accept_ (vcl_worker_t * wrk, vcl_session_t * ls)
{
  if (ls->is_vep)
    {
      VDBG (0, "ERROR: cannot accept on epoll session %u!",
	    ls->session_index);
      return VPPCOM_EBADFD;
    }

  if ((ls->session_state != STATE_LISTEN)
      && (!vcl_session_is_connectable_listener (wrk, ls)))
    {
      VDBG (0,
	    "ERROR: session [0x%llx]: not in listen state! state 0x%x"
	    " (%s)", ls->vpp_handle, ls->session_state,
	    vppcom_session_state_str (ls->session_state));
      return VPPCOM_EBADFD;
    }
  return VPPCOM_OK;
}

int
vppcom_unformat_proto (uint8_t * proto, char *proto_str)
{
  if (!strcmp (proto_str, "TCP"))
    *proto = VPPCOM_PROTO_TCP;
  else if (!strcmp (proto_str, "tcp"))
    *proto = VPPCOM_PROTO_TCP;
  else if (!strcmp (proto_str, "UDP"))
    *proto = VPPCOM_PROTO_UDP;
  else if (!strcmp (proto_str, "udp"))
    *proto = VPPCOM_PROTO_UDP;
  else if (!strcmp (proto_str, "UDPC"))
    *proto = VPPCOM_PROTO_UDPC;
  else if (!strcmp (proto_str, "udpc"))
    *proto = VPPCOM_PROTO_UDPC;
  else if (!strcmp (proto_str, "SCTP"))
    *proto = VPPCOM_PROTO_SCTP;
  else if (!strcmp (proto_str, "sctp"))
    *proto = VPPCOM_PROTO_SCTP;
  else if (!strcmp (proto_str, "TLS"))
    *proto = VPPCOM_PROTO_TLS;
  else if (!strcmp (proto_str, "tls"))
    *proto = VPPCOM_PROTO_TLS;
  else if (!strcmp (proto_str, "QUIC"))
    *proto = VPPCOM_PROTO_QUIC;
  else if (!strcmp (proto_str, "quic"))
    *proto = VPPCOM_PROTO_QUIC;
  else
    return 1;
  return 0;
}

int
vppcom_session_accept (uint32_t listen_session_handle, vppcom_endpt_t * ep,
		       uint32_t flags)
{
  u32 client_session_index = ~0, listen_session_index, accept_flags = 0;
  vcl_worker_t *wrk = vcl_worker_get_current ();
  session_accepted_msg_t accepted_msg;
  vcl_session_t *listen_session = 0;
  vcl_session_t *client_session = 0;
  vcl_session_msg_t *evt;
  svm_msg_q_msg_t msg;
  session_event_t *e;
  u8 is_nonblocking;
  int rv;

  listen_session = vcl_session_get_w_handle (wrk, listen_session_handle);
  if (!listen_session)
    return VPPCOM_EBADFD;

  listen_session_index = listen_session->session_index;
  if ((rv = validate_args_session_accept_ (wrk, listen_session)))
    return rv;

  if (clib_fifo_elts (listen_session->accept_evts_fifo))
    {
      clib_fifo_sub2 (listen_session->accept_evts_fifo, evt);
      accept_flags = evt->flags;
      accepted_msg = evt->accepted_msg;
      goto handle;
    }

  is_nonblocking = VCL_SESS_ATTR_TEST (listen_session->attr,
				       VCL_SESS_ATTR_NONBLOCK);
  if (svm_msg_q_is_empty (wrk->app_event_queue) && is_nonblocking)
    return VPPCOM_EAGAIN;

  while (1)
    {
      if (svm_msg_q_sub (wrk->app_event_queue, &msg, SVM_Q_WAIT, 0))
	return VPPCOM_EAGAIN;

      e = svm_msg_q_msg_data (wrk->app_event_queue, &msg);
      if (e->event_type != SESSION_CTRL_EVT_ACCEPTED)
	{
	  VDBG (0, "discarded event: %u", e->event_type);
	  svm_msg_q_free_msg (wrk->app_event_queue, &msg);
	  continue;
	}
      clib_memcpy_fast (&accepted_msg, e->data, sizeof (accepted_msg));
      svm_msg_q_free_msg (wrk->app_event_queue, &msg);
      break;
    }

handle:

  client_session_index = vcl_session_accepted_handler (wrk, &accepted_msg,
						       listen_session_index);
  if (client_session_index == VCL_INVALID_SESSION_INDEX)
    return VPPCOM_ECONNABORTED;

  listen_session = vcl_session_get (wrk, listen_session_index);
  client_session = vcl_session_get (wrk, client_session_index);

  if (flags & O_NONBLOCK)
    VCL_SESS_ATTR_SET (client_session->attr, VCL_SESS_ATTR_NONBLOCK);

  VDBG (1, "listener %u [0x%llx]: Got a connect request! session %u [0x%llx],"
	" flags %d, is_nonblocking %u", listen_session->session_index,
	listen_session->vpp_handle, client_session_index,
	client_session->vpp_handle, flags,
	VCL_SESS_ATTR_TEST (client_session->attr, VCL_SESS_ATTR_NONBLOCK));

  if (ep)
    {
      ep->is_ip4 = client_session->transport.is_ip4;
      ep->port = client_session->transport.rmt_port;
      if (client_session->transport.is_ip4)
	clib_memcpy_fast (ep->ip, &client_session->transport.rmt_ip.ip4,
			  sizeof (ip4_address_t));
      else
	clib_memcpy_fast (ep->ip, &client_session->transport.rmt_ip.ip6,
			  sizeof (ip6_address_t));
    }

  VDBG (0, "listener %u [0x%llx] accepted %u [0x%llx] peer: %U:%u "
	"local: %U:%u", listen_session_handle, listen_session->vpp_handle,
	client_session_index, client_session->vpp_handle,
	format_ip46_address, &client_session->transport.rmt_ip,
	client_session->transport.is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
	clib_net_to_host_u16 (client_session->transport.rmt_port),
	format_ip46_address, &client_session->transport.lcl_ip,
	client_session->transport.is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
	clib_net_to_host_u16 (client_session->transport.lcl_port));
  vcl_evt (VCL_EVT_ACCEPT, client_session, listen_session,
	   client_session_index);

  /*
   * Session might have been closed already
   */
  if (accept_flags)
    {
      if (accept_flags & VCL_ACCEPTED_F_CLOSED)
	client_session->session_state = STATE_VPP_CLOSING;
      else if (accept_flags & VCL_ACCEPTED_F_RESET)
	client_session->session_state = STATE_DISCONNECT;
    }
  return vcl_session_handle (client_session);
}

static void
vcl_ip_copy_from_ep (ip46_address_t * ip, vppcom_endpt_t * ep)
{
  if (ep->is_ip4)
    clib_memcpy_fast (&ip->ip4, ep->ip, sizeof (ip4_address_t));
  else
    clib_memcpy_fast (&ip->ip6, ep->ip, sizeof (ip6_address_t));
}

void
vcl_ip_copy_to_ep (ip46_address_t * ip, vppcom_endpt_t * ep, u8 is_ip4)
{
  ep->is_ip4 = is_ip4;
  if (is_ip4)
    clib_memcpy_fast (ep->ip, &ip->ip4, sizeof (ip4_address_t));
  else
    clib_memcpy_fast (ep->ip, &ip->ip6, sizeof (ip6_address_t));
}

int
vppcom_session_connect (uint32_t session_handle, vppcom_endpt_t * server_ep)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session = 0;
  u32 session_index;
  int rv;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;
  session_index = session->session_index;

  if (PREDICT_FALSE (session->is_vep))
    {
      VDBG (0, "ERROR: cannot connect epoll session %u!",
	    session->session_index);
      return VPPCOM_EBADFD;
    }

  if (PREDICT_FALSE (session->session_state & CLIENT_STATE_OPEN))
    {
      VDBG (0, "session handle %u [0x%llx]: session already "
	    "connected to %s %U port %d proto %s, state 0x%x (%s)",
	    session_handle, session->vpp_handle,
	    session->transport.is_ip4 ? "IPv4" : "IPv6", format_ip46_address,
	    &session->transport.rmt_ip, session->transport.is_ip4 ?
	    IP46_TYPE_IP4 : IP46_TYPE_IP6,
	    clib_net_to_host_u16 (session->transport.rmt_port),
	    vppcom_proto_str (session->session_type), session->session_state,
	    vppcom_session_state_str (session->session_state));
      return VPPCOM_OK;
    }

  session->transport.is_ip4 = server_ep->is_ip4;
  vcl_ip_copy_from_ep (&session->transport.rmt_ip, server_ep);
  session->transport.rmt_port = server_ep->port;
  session->parent_handle = VCL_INVALID_SESSION_HANDLE;

  VDBG (0, "session handle %u: connecting to server %s %U "
	"port %d proto %s", session_handle,
	session->transport.is_ip4 ? "IPv4" : "IPv6",
	format_ip46_address,
	&session->transport.rmt_ip, session->transport.is_ip4 ?
	IP46_TYPE_IP4 : IP46_TYPE_IP6,
	clib_net_to_host_u16 (session->transport.rmt_port),
	vppcom_proto_str (session->session_type));

  vcl_send_session_connect (wrk, session);

  if (VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_NONBLOCK))
    return VPPCOM_EINPROGRESS;

  /*
   * Wait for reply from vpp if blocking
   */
  rv = vppcom_wait_for_session_state_change (session_index, STATE_CONNECT,
					     vcm->cfg.session_timeout);

  session = vcl_session_get (wrk, session_index);
  VDBG (0, "session %u [0x%llx]: connect %s!", session->session_index,
	session->vpp_handle, rv ? "failed" : "succeeded");

  return rv;
}

int
vppcom_session_stream_connect (uint32_t session_handle,
			       uint32_t parent_session_handle)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session, *parent_session;
  u32 session_index, parent_session_index;
  int rv;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;
  parent_session = vcl_session_get_w_handle (wrk, parent_session_handle);
  if (!parent_session)
    return VPPCOM_EBADFD;

  session_index = session->session_index;
  parent_session_index = parent_session->session_index;
  if (PREDICT_FALSE (session->is_vep))
    {
      VDBG (0, "ERROR: cannot connect epoll session %u!",
	    session->session_index);
      return VPPCOM_EBADFD;
    }

  if (PREDICT_FALSE (session->session_state & CLIENT_STATE_OPEN))
    {
      VDBG (0, "session handle %u [0x%llx]: session already "
	    "connected to session %u [0x%llx] proto %s, state 0x%x (%s)",
	    session_handle, session->vpp_handle,
	    parent_session_handle, parent_session->vpp_handle,
	    vppcom_proto_str (session->session_type), session->session_state,
	    vppcom_session_state_str (session->session_state));
      return VPPCOM_OK;
    }

  /* Connect to quic session specifics */
  session->transport.is_ip4 = parent_session->transport.is_ip4;
  session->transport.rmt_ip.ip4.as_u32 = (uint32_t) 1;
  session->transport.rmt_port = 0;
  session->parent_handle = parent_session->vpp_handle;

  VDBG (0, "session handle %u: connecting to session %u [0x%llx]",
	session_handle, parent_session_handle, parent_session->vpp_handle);

  /*
   * Send connect request and wait for reply from vpp
   */
  vcl_send_session_connect (wrk, session);
  rv = vppcom_wait_for_session_state_change (session_index, STATE_CONNECT,
					     vcm->cfg.session_timeout);

  session->listener_index = parent_session_index;
  parent_session = vcl_session_get_w_handle (wrk, parent_session_handle);
  if (parent_session)
    parent_session->n_accepted_sessions++;

  session = vcl_session_get (wrk, session_index);
  VDBG (0, "session %u [0x%llx]: connect %s!", session->session_index,
	session->vpp_handle, rv ? "failed" : "succeeded");

  return rv;
}

static u8
vcl_is_rx_evt_for_session (session_event_t * e, u32 sid, u8 is_ct)
{
  return (e->event_type == SESSION_IO_EVT_RX && e->session_index == sid);
}

static inline int
vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
			      u8 peek)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  int n_read = 0, is_nonblocking;
  vcl_session_t *s = 0;
  svm_fifo_t *rx_fifo;
  svm_msg_q_msg_t msg;
  session_event_t *e;
  svm_msg_q_t *mq;
  u8 is_ct;

  if (PREDICT_FALSE (!buf))
    return VPPCOM_EINVAL;

  s = vcl_session_get_w_handle (wrk, session_handle);
  if (PREDICT_FALSE (!s || s->is_vep))
    return VPPCOM_EBADFD;

  if (PREDICT_FALSE (!vcl_session_is_open (s)))
    {
      VDBG (0, "session %u[0x%llx] is not open! state 0x%x (%s)",
	    s->session_index, s->vpp_handle, s->session_state,
	    vppcom_session_state_str (s->session_state));
      return vcl_session_closed_error (s);
    }

  is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);
  is_ct = vcl_session_is_ct (s);
  mq = wrk->app_event_queue;
  rx_fifo = is_ct ? s->ct_rx_fifo : s->rx_fifo;
  s->has_rx_evt = 0;

  if (svm_fifo_is_empty_cons (rx_fifo))
    {
      if (is_nonblocking)
	{
	  svm_fifo_unset_event (s->rx_fifo);
	  return VPPCOM_EWOULDBLOCK;
	}
      while (svm_fifo_is_empty_cons (rx_fifo))
	{
	  if (vcl_session_is_closing (s))
	    return vcl_session_closing_error (s);

	  svm_fifo_unset_event (s->rx_fifo);
	  svm_msg_q_lock (mq);
	  if (svm_msg_q_is_empty (mq))
	    svm_msg_q_wait (mq);

	  svm_msg_q_sub_w_lock (mq, &msg);
	  e = svm_msg_q_msg_data (mq, &msg);
	  svm_msg_q_unlock (mq);
	  if (!vcl_is_rx_evt_for_session (e, s->session_index, is_ct))
	    vcl_handle_mq_event (wrk, e);
	  svm_msg_q_free_msg (mq, &msg);
	}
    }

  if (s->is_dgram)
    n_read = app_recv_dgram_raw (rx_fifo, buf, n, &s->transport, 0, peek);
  else
    n_read = app_recv_stream_raw (rx_fifo, buf, n, 0, peek);

  if (svm_fifo_is_empty_cons (rx_fifo))
    svm_fifo_unset_event (s->rx_fifo);

  /* Cut-through sessions might request tx notifications on rx fifos */
  if (PREDICT_FALSE (rx_fifo->want_deq_ntf))
    {
      app_send_io_evt_to_vpp (s->vpp_evt_q, s->rx_fifo->master_session_index,
			      SESSION_IO_EVT_RX, SVM_Q_WAIT);
      svm_fifo_reset_has_deq_ntf (s->rx_fifo);
    }

  VDBG (2, "session %u[0x%llx]: read %d bytes from (%p)", s->session_index,
	s->vpp_handle, n_read, rx_fifo);

  return n_read;
}

int
vppcom_session_read (uint32_t session_handle, void *buf, size_t n)
{
  return (vppcom_session_read_internal (session_handle, buf, n, 0));
}

static int
vppcom_session_peek (uint32_t session_handle, void *buf, int n)
{
  return (vppcom_session_read_internal (session_handle, buf, n, 1));
}

int
vppcom_session_read_segments (uint32_t session_handle,
			      vppcom_data_segments_t ds)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  int n_read = 0, is_nonblocking;
  vcl_session_t *s = 0;
  svm_fifo_t *rx_fifo;
  svm_msg_q_msg_t msg;
  session_event_t *e;
  svm_msg_q_t *mq;
  u8 is_ct;

  s = vcl_session_get_w_handle (wrk, session_handle);
  if (PREDICT_FALSE (!s || s->is_vep))
    return VPPCOM_EBADFD;

  if (PREDICT_FALSE (!vcl_session_is_open (s)))
    return vcl_session_closed_error (s);

  is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);
  is_ct = vcl_session_is_ct (s);
  mq = is_ct ? s->our_evt_q : wrk->app_event_queue;
  rx_fifo = s->rx_fifo;
  s->has_rx_evt = 0;

  if (is_ct)
    svm_fifo_unset_event (s->rx_fifo);

  if (svm_fifo_is_empty_cons (rx_fifo))
    {
      if (is_nonblocking)
	{
	  svm_fifo_unset_event (rx_fifo);
	  return VPPCOM_EWOULDBLOCK;
	}
      while (svm_fifo_is_empty_cons (rx_fifo))
	{
	  if (vcl_session_is_closing (s))
	    return vcl_session_closing_error (s);

	  svm_fifo_unset_event (rx_fifo);
	  svm_msg_q_lock (mq);
	  if (svm_msg_q_is_empty (mq))
	    svm_msg_q_wait (mq);

	  svm_msg_q_sub_w_lock (mq, &msg);
	  e = svm_msg_q_msg_data (mq, &msg);
	  svm_msg_q_unlock (mq);
	  if (!vcl_is_rx_evt_for_session (e, s->session_index, is_ct))
	    vcl_handle_mq_event (wrk, e);
	  svm_msg_q_free_msg (mq, &msg);
	}
    }

  n_read = svm_fifo_segments (rx_fifo, (svm_fifo_seg_t *) ds);
  svm_fifo_unset_event (rx_fifo);

  return n_read;
}

void
vppcom_session_free_segments (uint32_t session_handle,
			      vppcom_data_segments_t ds)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *s;

  s = vcl_session_get_w_handle (wrk, session_handle);
  if (PREDICT_FALSE (!s || s->is_vep))
    return;

  svm_fifo_segments_free (s->rx_fifo, (svm_fifo_seg_t *) ds);
}

int
vppcom_data_segment_copy (void *buf, vppcom_data_segments_t ds, u32 max_bytes)
{
  u32 first_copy = clib_min (ds[0].len, max_bytes);
  clib_memcpy_fast (buf, ds[0].data, first_copy);
  if (first_copy < max_bytes)
    {
      clib_memcpy_fast (buf + first_copy, ds[1].data,
			clib_min (ds[1].len, max_bytes - first_copy));
    }
  return 0;
}

static u8
vcl_is_tx_evt_for_session (session_event_t * e, u32 sid, u8 is_ct)
{
  return (e->event_type == SESSION_IO_EVT_TX && e->session_index == sid);
}

static inline int
vppcom_session_write_inline (uint32_t session_handle, void *buf, size_t n,
			     u8 is_flush)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  int n_write, is_nonblocking;
  vcl_session_t *s = 0;
  session_evt_type_t et;
  svm_msg_q_msg_t msg;
  svm_fifo_t *tx_fifo;
  session_event_t *e;
  svm_msg_q_t *mq;
  u8 is_ct;

  if (PREDICT_FALSE (!buf))
    return VPPCOM_EINVAL;

  s = vcl_session_get_w_handle (wrk, session_handle);
  if (PREDICT_FALSE (!s))
    return VPPCOM_EBADFD;

  if (PREDICT_FALSE (s->is_vep))
    {
      VDBG (0, "ERROR: session %u [0x%llx]: cannot write to an epoll"
	    " session!", s->session_index, s->vpp_handle);
      return VPPCOM_EBADFD;
    }

  if (PREDICT_FALSE (!vcl_session_is_open (s)))
    {
      VDBG (1, "session %u [0x%llx]: is not open! state 0x%x (%s)",
	    s->session_index, s->vpp_handle, s->session_state,
	    vppcom_session_state_str (s->session_state));
      return vcl_session_closed_error (s);;
    }

  is_ct = vcl_session_is_ct (s);
  tx_fifo = is_ct ? s->ct_tx_fifo : s->tx_fifo;
  is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);

  mq = wrk->app_event_queue;
  if (svm_fifo_is_full_prod (tx_fifo))
    {
      if (is_nonblocking)
	{
	  return VPPCOM_EWOULDBLOCK;
	}
      while (svm_fifo_is_full_prod (tx_fifo))
	{
	  svm_fifo_add_want_deq_ntf (tx_fifo, SVM_FIFO_WANT_DEQ_NOTIF);
	  if (vcl_session_is_closing (s))
	    return vcl_session_closing_error (s);
	  svm_msg_q_lock (mq);
	  if (svm_msg_q_is_empty (mq))
	    svm_msg_q_wait (mq);

	  svm_msg_q_sub_w_lock (mq, &msg);
	  e = svm_msg_q_msg_data (mq, &msg);
	  svm_msg_q_unlock (mq);

	  if (!vcl_is_tx_evt_for_session (e, s->session_index, is_ct))
	    vcl_handle_mq_event (wrk, e);
	  svm_msg_q_free_msg (mq, &msg);
	}
    }

  et = SESSION_IO_EVT_TX;
  if (is_flush && !is_ct)
    et = SESSION_IO_EVT_TX_FLUSH;

  if (s->is_dgram)
    n_write = app_send_dgram_raw (tx_fifo, &s->transport,
				  s->vpp_evt_q, buf, n, et,
				  0 /* do_evt */ , SVM_Q_WAIT);
  else
    n_write = app_send_stream_raw (tx_fifo, s->vpp_evt_q, buf, n, et,
				   0 /* do_evt */ , SVM_Q_WAIT);

  if (svm_fifo_set_event (s->tx_fifo))
    app_send_io_evt_to_vpp (s->vpp_evt_q, s->tx_fifo->master_session_index,
			    et, SVM_Q_WAIT);

  ASSERT (n_write > 0);

  VDBG (2, "session %u [0x%llx]: wrote %d bytes", s->session_index,
	s->vpp_handle, n_write);

  return n_write;
}

int
vppcom_session_write (uint32_t session_handle, void *buf, size_t n)
{
  return vppcom_session_write_inline (session_handle, buf, n,
				      0 /* is_flush */ );
}

int
vppcom_session_write_msg (uint32_t session_handle, void *buf, size_t n)
{
  return vppcom_session_write_inline (session_handle, buf, n,
				      1 /* is_flush */ );
}

#define vcl_fifo_rx_evt_valid_or_break(_s)				\
if (PREDICT_FALSE (!_s->rx_fifo))					\
  break;								\
if (PREDICT_FALSE (svm_fifo_is_empty (_s->rx_fifo)))			\
  {									\
    if (!vcl_session_is_ct (_s))					\
      {									\
	svm_fifo_unset_event (_s->rx_fifo);				\
	if (svm_fifo_is_empty (_s->rx_fifo))				\
	  break;							\
      }									\
    else if (svm_fifo_is_empty (_s->ct_rx_fifo))			\
      {									\
	svm_fifo_unset_event (_s->ct_rx_fifo);				\
	if (svm_fifo_is_empty (_s->ct_rx_fifo))				\
	  break;							\
      }									\
  }									\

static void
vcl_select_handle_mq_event (vcl_worker_t * wrk, session_event_t * e,
			    unsigned long n_bits, unsigned long *read_map,
			    unsigned long *write_map,
			    unsigned long *except_map, u32 * bits_set)
{
  session_disconnected_msg_t *disconnected_msg;
  session_connected_msg_t *connected_msg;
  vcl_session_t *session;
  u32 sid;

  switch (e->event_type)
    {
    case SESSION_IO_EVT_RX:
      sid = e->session_index;
      session = vcl_session_get (wrk, sid);
      if (!session)
	break;
      vcl_fifo_rx_evt_valid_or_break (session);
      if (sid < n_bits && read_map)
	{
	  clib_bitmap_set_no_check ((uword *) read_map, sid, 1);
	  *bits_set += 1;
	}
      break;
    case SESSION_IO_EVT_TX:
      sid = e->session_index;
      session = vcl_session_get (wrk, sid);
      if (!session)
	break;
      if (sid < n_bits && write_map)
	{
	  clib_bitmap_set_no_check ((uword *) write_map, sid, 1);
	  *bits_set += 1;
	}
      break;
    case SESSION_CTRL_EVT_ACCEPTED:
      session = vcl_session_accepted (wrk,
				      (session_accepted_msg_t *) e->data);
      if (!session)
	break;
      sid = session->session_index;
      if (sid < n_bits && read_map)
	{
	  clib_bitmap_set_no_check ((uword *) read_map, sid, 1);
	  *bits_set += 1;
	}
      break;
    case SESSION_CTRL_EVT_CONNECTED:
      connected_msg = (session_connected_msg_t *) e->data;
      sid = vcl_session_connected_handler (wrk, connected_msg);
      if (sid == VCL_INVALID_SESSION_INDEX)
	break;
      if (sid < n_bits && write_map)
	{
	  clib_bitmap_set_no_check ((uword *) write_map, sid, 1);
	  *bits_set += 1;
	}
      break;
    case SESSION_CTRL_EVT_DISCONNECTED:
      disconnected_msg = (session_disconnected_msg_t *) e->data;
      session = vcl_session_disconnected_handler (wrk, disconnected_msg);
      if (!session)
	break;
      sid = session->session_index;
      if (sid < n_bits && except_map)
	{
	  clib_bitmap_set_no_check ((uword *) except_map, sid, 1);
	  *bits_set += 1;
	}
      break;
    case SESSION_CTRL_EVT_RESET:
      sid = vcl_session_reset_handler (wrk, (session_reset_msg_t *) e->data);
      if (sid < n_bits && except_map)
	{
	  clib_bitmap_set_no_check ((uword *) except_map, sid, 1);
	  *bits_set += 1;
	}
      break;
    case SESSION_CTRL_EVT_UNLISTEN_REPLY:
      vcl_session_unlisten_reply_handler (wrk, e->data);
      break;
    case SESSION_CTRL_EVT_WORKER_UPDATE_REPLY:
      vcl_session_worker_update_reply_handler (wrk, e->data);
      break;
    case SESSION_CTRL_EVT_REQ_WORKER_UPDATE:
      vcl_session_req_worker_update_handler (wrk, e->data);
      break;
    default:
      clib_warning ("unhandled: %u", e->event_type);
      break;
    }
}

static int
vcl_select_handle_mq (vcl_worker_t * wrk, svm_msg_q_t * mq,
		      unsigned long n_bits, unsigned long *read_map,
		      unsigned long *write_map, unsigned long *except_map,
		      double time_to_wait, u32 * bits_set)
{
  svm_msg_q_msg_t *msg;
  session_event_t *e;
  u32 i;

  svm_msg_q_lock (mq);
  if (svm_msg_q_is_empty (mq))
    {
      if (*bits_set)
	{
	  svm_msg_q_unlock (mq);
	  return 0;
	}

      if (!time_to_wait)
	{
	  svm_msg_q_unlock (mq);
	  return 0;
	}
      else if (time_to_wait < 0)
	{
	  svm_msg_q_wait (mq);
	}
      else
	{
	  if (svm_msg_q_timedwait (mq, time_to_wait))
	    {
	      svm_msg_q_unlock (mq);
	      return 0;
	    }
	}
    }
  vcl_mq_dequeue_batch (wrk, mq, ~0);
  svm_msg_q_unlock (mq);

  for (i = 0; i < vec_len (wrk->mq_msg_vector); i++)
    {
      msg = vec_elt_at_index (wrk->mq_msg_vector, i);
      e = svm_msg_q_msg_data (mq, msg);
      vcl_select_handle_mq_event (wrk, e, n_bits, read_map, write_map,
				  except_map, bits_set);
      svm_msg_q_free_msg (mq, msg);
    }
  vec_reset_length (wrk->mq_msg_vector);
  vcl_handle_pending_wrk_updates (wrk);
  return *bits_set;
}

static int
vppcom_select_condvar (vcl_worker_t * wrk, int n_bits,
		       vcl_si_set * read_map, vcl_si_set * write_map,
		       vcl_si_set * except_map, double time_to_wait,
		       u32 * bits_set)
{
  double wait = 0, start = 0;

  if (!*bits_set)
    {
      wait = time_to_wait;
      start = clib_time_now (&wrk->clib_time);
    }

  do
    {
      vcl_select_handle_mq (wrk, wrk->app_event_queue, n_bits, read_map,
			    write_map, except_map, wait, bits_set);
      if (*bits_set)
	return *bits_set;
      if (wait == -1)
	continue;

      wait = wait - (clib_time_now (&wrk->clib_time) - start);
    }
  while (wait > 0);

  return 0;
}

static int
vppcom_select_eventfd (vcl_worker_t * wrk, int n_bits,
		       vcl_si_set * read_map, vcl_si_set * write_map,
		       vcl_si_set * except_map, double time_to_wait,
		       u32 * bits_set)
{
  vcl_mq_evt_conn_t *mqc;
  int __clib_unused n_read;
  int n_mq_evts, i;
  u64 buf;

  vec_validate (wrk->mq_events, pool_elts (wrk->mq_evt_conns));
  n_mq_evts = epoll_wait (wrk->mqs_epfd, wrk->mq_events,
			  vec_len (wrk->mq_events), time_to_wait);
  for (i = 0; i < n_mq_evts; i++)
    {
      mqc = vcl_mq_evt_conn_get (wrk, wrk->mq_events[i].data.u32);
      n_read = read (mqc->mq_fd, &buf, sizeof (buf));
      vcl_select_handle_mq (wrk, mqc->mq, n_bits, read_map, write_map,
			    except_map, 0, bits_set);
    }

  return (n_mq_evts > 0 ? (int) *bits_set : 0);
}

int
vppcom_select (int n_bits, vcl_si_set * read_map, vcl_si_set * write_map,
	       vcl_si_set * except_map, double time_to_wait)
{
  u32 sid, minbits = clib_max (n_bits, BITS (uword)), bits_set = 0;
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session = 0;
  int rv, i;

  if (n_bits && read_map)
    {
      clib_bitmap_validate (wrk->rd_bitmap, minbits);
      clib_memcpy_fast (wrk->rd_bitmap, read_map,
			vec_len (wrk->rd_bitmap) * sizeof (vcl_si_set));
      memset (read_map, 0, vec_len (wrk->rd_bitmap) * sizeof (vcl_si_set));
    }
  if (n_bits && write_map)
    {
      clib_bitmap_validate (wrk->wr_bitmap, minbits);
      clib_memcpy_fast (wrk->wr_bitmap, write_map,
			vec_len (wrk->wr_bitmap) * sizeof (vcl_si_set));
      memset (write_map, 0, vec_len (wrk->wr_bitmap) * sizeof (vcl_si_set));
    }
  if (n_bits && except_map)
    {
      clib_bitmap_validate (wrk->ex_bitmap, minbits);
      clib_memcpy_fast (wrk->ex_bitmap, except_map,
			vec_len (wrk->ex_bitmap) * sizeof (vcl_si_set));
      memset (except_map, 0, vec_len (wrk->ex_bitmap) * sizeof (vcl_si_set));
    }

  if (!n_bits)
    return 0;

  if (!write_map)
    goto check_rd;

  /* *INDENT-OFF* */
  clib_bitmap_foreach (sid, wrk->wr_bitmap, ({
    if (!(session = vcl_session_get (wrk, sid)))
      {
        if (except_map && sid < minbits)
          clib_bitmap_set_no_check (except_map, sid, 1);
        continue;
      }

    rv = svm_fifo_is_full_prod (session->tx_fifo);
    if (!rv)
      {
        clib_bitmap_set_no_check ((uword*)write_map, sid, 1);
        bits_set++;
      }
    else
      svm_fifo_add_want_deq_ntf (session->tx_fifo, SVM_FIFO_WANT_DEQ_NOTIF);
  }));

check_rd:
  if (!read_map)
    goto check_mq;

  clib_bitmap_foreach (sid, wrk->rd_bitmap, ({
    if (!(session = vcl_session_get (wrk, sid)))
      {
        if (except_map && sid < minbits)
          clib_bitmap_set_no_check (except_map, sid, 1);
        continue;
      }

    rv = vcl_session_read_ready (session);
    if (rv)
      {
        clib_bitmap_set_no_check ((uword*)read_map, sid, 1);
        bits_set++;
      }
  }));
  /* *INDENT-ON* */

check_mq:

  for (i = 0; i < vec_len (wrk->unhandled_evts_vector); i++)
    {
      vcl_select_handle_mq_event (wrk, &wrk->unhandled_evts_vector[i], n_bits,
				  read_map, write_map, except_map, &bits_set);
    }
  vec_reset_length (wrk->unhandled_evts_vector);

  if (vcm->cfg.use_mq_eventfd)
    vppcom_select_eventfd (wrk, n_bits, read_map, write_map, except_map,
			   time_to_wait, &bits_set);
  else
    vppcom_select_condvar (wrk, n_bits, read_map, write_map, except_map,
			   time_to_wait, &bits_set);

  return (bits_set);
}

static inline void
vep_verify_epoll_chain (vcl_worker_t * wrk, u32 vep_handle)
{
  vcl_session_t *session;
  vppcom_epoll_t *vep;
  u32 sh = vep_handle;

  if (VPPCOM_DEBUG <= 2)
    return;

  session = vcl_session_get_w_handle (wrk, vep_handle);
  if (PREDICT_FALSE (!session))
    {
      VDBG (0, "ERROR: Invalid vep_sh (%u)!", vep_handle);
      goto done;
    }
  if (PREDICT_FALSE (!session->is_vep))
    {
      VDBG (0, "ERROR: vep_sh (%u) is not a vep!", vep_handle);
      goto done;
    }
  vep = &session->vep;
  VDBG (0, "vep_sh (%u): Dumping epoll chain\n"
	"{\n"
	"   is_vep         = %u\n"
	"   is_vep_session = %u\n"
	"   next_sh        = 0x%x (%u)\n"
	"}\n", vep_handle, session->is_vep, session->is_vep_session,
	vep->next_sh, vep->next_sh);

  for (sh = vep->next_sh; sh != ~0; sh = vep->next_sh)
    {
      session = vcl_session_get_w_handle (wrk, sh);
      if (PREDICT_FALSE (!session))
	{
	  VDBG (0, "ERROR: Invalid sh (%u)!", sh);
	  goto done;
	}
      if (PREDICT_FALSE (session->is_vep))
	{
	  VDBG (0, "ERROR: sh (%u) is a vep!", vep_handle);
	}
      else if (PREDICT_FALSE (!session->is_vep_session))
	{
	  VDBG (0, "ERROR: sh (%u) is not a vep session handle!", sh);
	  goto done;
	}
      vep = &session->vep;
      if (PREDICT_FALSE (vep->vep_sh != vep_handle))
	VDBG (0, "ERROR: session (%u) vep_sh (%u) != vep_sh (%u)!",
	      sh, session->vep.vep_sh, vep_handle);
      if (session->is_vep_session)
	{
	  VDBG (0, "vep_sh[%u]: sh 0x%x (%u)\n"
		"{\n"
		"   next_sh        = 0x%x (%u)\n"
		"   prev_sh        = 0x%x (%u)\n"
		"   vep_sh         = 0x%x (%u)\n"
		"   ev.events      = 0x%x\n"
		"   ev.data.u64    = 0x%llx\n"
		"   et_mask        = 0x%x\n"
		"}\n",
		vep_handle, sh, sh, vep->next_sh, vep->next_sh, vep->prev_sh,
		vep->prev_sh, vep->vep_sh, vep->vep_sh, vep->ev.events,
		vep->ev.data.u64, vep->et_mask);
	}
    }

done:
  VDBG (0, "vep_sh (%u): Dump complete!\n", vep_handle);
}

int
vppcom_epoll_create (void)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *vep_session;

  vep_session = vcl_session_alloc (wrk);

  vep_session->is_vep = 1;
  vep_session->vep.vep_sh = ~0;
  vep_session->vep.next_sh = ~0;
  vep_session->vep.prev_sh = ~0;
  vep_session->vpp_handle = ~0;

  vcl_evt (VCL_EVT_EPOLL_CREATE, vep_session, vep_session->session_index);
  VDBG (0, "Created vep_idx %u", vep_session->session_index);

  return vcl_session_handle (vep_session);
}

int
vppcom_epoll_ctl (uint32_t vep_handle, int op, uint32_t session_handle,
		  struct epoll_event *event)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *vep_session;
  vcl_session_t *session;
  int rv = VPPCOM_OK;

  if (vep_handle == session_handle)
    {
      VDBG (0, "vep_sh == session handle (%u)!", vep_handle);
      return VPPCOM_EINVAL;
    }

  vep_session = vcl_session_get_w_handle (wrk, vep_handle);
  if (PREDICT_FALSE (!vep_session))
    {
      VDBG (0, "Invalid vep_sh (%u)!", vep_handle);
      return VPPCOM_EBADFD;
    }
  if (PREDICT_FALSE (!vep_session->is_vep))
    {
      VDBG (0, "vep_sh (%u) is not a vep!", vep_handle);
      return VPPCOM_EINVAL;
    }

  ASSERT (vep_session->vep.vep_sh == ~0);
  ASSERT (vep_session->vep.prev_sh == ~0);

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (PREDICT_FALSE (!session))
    {
      VDBG (0, "Invalid session_handle (%u)!", session_handle);
      return VPPCOM_EBADFD;
    }
  if (PREDICT_FALSE (session->is_vep))
    {
      VDBG (0, "session_handle (%u) is a vep!", vep_handle);
      return VPPCOM_EINVAL;
    }

  switch (op)
    {
    case EPOLL_CTL_ADD:
      if (PREDICT_FALSE (!event))
	{
	  VDBG (0, "EPOLL_CTL_ADD: NULL pointer to epoll_event structure!");
	  return VPPCOM_EINVAL;
	}
      if (vep_session->vep.next_sh != ~0)
	{
	  vcl_session_t *next_session;
	  next_session = vcl_session_get_w_handle (wrk,
						   vep_session->vep.next_sh);
	  if (PREDICT_FALSE (!next_session))
	    {
	      VDBG (0, "EPOLL_CTL_ADD: Invalid vep.next_sh (%u) on "
		    "vep_idx (%u)!", vep_session->vep.next_sh, vep_handle);
	      return VPPCOM_EBADFD;
	    }
	  ASSERT (next_session->vep.prev_sh == vep_handle);
	  next_session->vep.prev_sh = session_handle;
	}
      session->vep.next_sh = vep_session->vep.next_sh;
      session->vep.prev_sh = vep_handle;
      session->vep.vep_sh = vep_handle;
      session->vep.et_mask = VEP_DEFAULT_ET_MASK;
      session->vep.ev = *event;
      session->is_vep = 0;
      session->is_vep_session = 1;
      vep_session->vep.next_sh = session_handle;

      if (session->tx_fifo)
	svm_fifo_add_want_deq_ntf (session->tx_fifo,
				   SVM_FIFO_WANT_DEQ_NOTIF_IF_FULL);

      VDBG (1, "EPOLL_CTL_ADD: vep_sh %u, sh %u, events 0x%x, data 0x%llx!",
	    vep_handle, session_handle, event->events, event->data.u64);
      vcl_evt (VCL_EVT_EPOLL_CTLADD, session, event->events, event->data.u64);
      break;

    case EPOLL_CTL_MOD:
      if (PREDICT_FALSE (!event))
	{
	  VDBG (0, "EPOLL_CTL_MOD: NULL pointer to epoll_event structure!");
	  rv = VPPCOM_EINVAL;
	  goto done;
	}
      else if (PREDICT_FALSE (!session->is_vep_session))
	{
	  VDBG (0, "sh %u EPOLL_CTL_MOD: not a vep session!", session_handle);
	  rv = VPPCOM_EINVAL;
	  goto done;
	}
      else if (PREDICT_FALSE (session->vep.vep_sh != vep_handle))
	{
	  VDBG (0, "EPOLL_CTL_MOD: sh %u vep_sh (%u) != vep_sh (%u)!",
		session_handle, session->vep.vep_sh, vep_handle);
	  rv = VPPCOM_EINVAL;
	  goto done;
	}
      session->vep.et_mask = VEP_DEFAULT_ET_MASK;
      session->vep.ev = *event;
      VDBG (1, "EPOLL_CTL_MOD: vep_sh %u, sh %u, events 0x%x, data 0x%llx!",
	    vep_handle, session_handle, event->events, event->data.u64);
      break;

    case EPOLL_CTL_DEL:
      if (PREDICT_FALSE (!session->is_vep_session))
	{
	  VDBG (0, "EPOLL_CTL_DEL: %u not a vep session!", session_handle);
	  rv = VPPCOM_EINVAL;
	  goto done;
	}
      else if (PREDICT_FALSE (session->vep.vep_sh != vep_handle))
	{
	  VDBG (0, "EPOLL_CTL_DEL: sh %u vep_sh (%u) != vep_sh (%u)!",
		session_handle, session->vep.vep_sh, vep_handle);
	  rv = VPPCOM_EINVAL;
	  goto done;
	}

      if (session->vep.prev_sh == vep_handle)
	vep_session->vep.next_sh = session->vep.next_sh;
      else
	{
	  vcl_session_t *prev_session;
	  prev_session = vcl_session_get_w_handle (wrk, session->vep.prev_sh);
	  if (PREDICT_FALSE (!prev_session))
	    {
	      VDBG (0, "EPOLL_CTL_DEL: Invalid prev_sh (%u) on sh (%u)!",
		    session->vep.prev_sh, session_handle);
	      return VPPCOM_EBADFD;
	    }
	  ASSERT (prev_session->vep.next_sh == session_handle);
	  prev_session->vep.next_sh = session->vep.next_sh;
	}
      if (session->vep.next_sh != ~0)
	{
	  vcl_session_t *next_session;
	  next_session = vcl_session_get_w_handle (wrk, session->vep.next_sh);
	  if (PREDICT_FALSE (!next_session))
	    {
	      VDBG (0, "EPOLL_CTL_DEL: Invalid next_sh (%u) on sh (%u)!",
		    session->vep.next_sh, session_handle);
	      return VPPCOM_EBADFD;
	    }
	  ASSERT (next_session->vep.prev_sh == session_handle);
	  next_session->vep.prev_sh = session->vep.prev_sh;
	}

      memset (&session->vep, 0, sizeof (session->vep));
      session->vep.next_sh = ~0;
      session->vep.prev_sh = ~0;
      session->vep.vep_sh = ~0;
      session->is_vep_session = 0;

      if (session->tx_fifo)
	svm_fifo_del_want_deq_ntf (session->tx_fifo, SVM_FIFO_NO_DEQ_NOTIF);

      VDBG (1, "EPOLL_CTL_DEL: vep_idx %u, sh %u!", vep_handle,
	    session_handle);
      vcl_evt (VCL_EVT_EPOLL_CTLDEL, session, vep_sh);
      break;

    default:
      VDBG (0, "Invalid operation (%d)!", op);
      rv = VPPCOM_EINVAL;
    }

  vep_verify_epoll_chain (wrk, vep_handle);

done:
  return rv;
}

static inline void
vcl_epoll_wait_handle_mq_event (vcl_worker_t * wrk, session_event_t * e,
				struct epoll_event *events, u32 * num_ev)
{
  session_disconnected_msg_t *disconnected_msg;
  session_connected_msg_t *connected_msg;
  u32 sid = ~0, session_events;
  u64 session_evt_data = ~0;
  vcl_session_t *session;
  u8 add_event = 0;

  switch (e->event_type)
    {
    case SESSION_IO_EVT_RX:
      sid = e->session_index;
      if (!(session = vcl_session_get (wrk, sid)))
	break;
      vcl_fifo_rx_evt_valid_or_break (session);
      session_events = session->vep.ev.events;
      if (!(EPOLLIN & session->vep.ev.events) || session->has_rx_evt)
	break;
      add_event = 1;
      events[*num_ev].events |= EPOLLIN;
      session_evt_data = session->vep.ev.data.u64;
      session->has_rx_evt = 1;
      break;
    case SESSION_IO_EVT_TX:
      sid = e->session_index;
      if (!(session = vcl_session_get (wrk, sid)))
	break;
      session_events = session->vep.ev.events;
      if (!(EPOLLOUT & session_events))
	break;
      add_event = 1;
      events[*num_ev].events |= EPOLLOUT;
      session_evt_data = session->vep.ev.data.u64;
      svm_fifo_reset_has_deq_ntf (session->tx_fifo);
      break;
    case SESSION_CTRL_EVT_ACCEPTED:
      session = vcl_session_accepted (wrk,
				      (session_accepted_msg_t *) e->data);
      if (!session)
	break;

      session_events = session->vep.ev.events;
      if (!(EPOLLIN & session_events))
	break;

      add_event = 1;
      events[*num_ev].events |= EPOLLIN;
      session_evt_data = session->vep.ev.data.u64;
      break;
    case SESSION_CTRL_EVT_CONNECTED:
      connected_msg = (session_connected_msg_t *) e->data;
      vcl_session_connected_handler (wrk, connected_msg);
      /* Generate EPOLLOUT because there's no connected event */
      sid = vcl_session_index_from_vpp_handle (wrk, connected_msg->handle);
      if (!(session = vcl_session_get (wrk, sid)))
	break;
      session_events = session->vep.ev.events;
      if (!(EPOLLOUT & session_events))
	break;
      add_event = 1;
      events[*num_ev].events |= EPOLLOUT;
      session_evt_data = session->vep.ev.data.u64;
      if (session->session_state & STATE_FAILED)
	events[*num_ev].events |= EPOLLHUP;
      break;
    case SESSION_CTRL_EVT_DISCONNECTED:
      disconnected_msg = (session_disconnected_msg_t *) e->data;
      session = vcl_session_disconnected_handler (wrk, disconnected_msg);
      if (!session)
	break;
      session_events = session->vep.ev.events;
      if (!((EPOLLHUP | EPOLLRDHUP) & session_events))
	break;
      add_event = 1;
      events[*num_ev].events |= EPOLLHUP | EPOLLRDHUP;
      session_evt_data = session->vep.ev.data.u64;
      break;
    case SESSION_CTRL_EVT_RESET:
      sid = vcl_session_reset_handler (wrk, (session_reset_msg_t *) e->data);
      if (!(session = vcl_session_get (wrk, sid)))
	break;
      session_events = session->vep.ev.events;
      if (!((EPOLLHUP | EPOLLRDHUP) & session_events))
	break;
      add_event = 1;
      events[*num_ev].events |= EPOLLHUP | EPOLLRDHUP;
      session_evt_data = session->vep.ev.data.u64;
      break;
    case SESSION_CTRL_EVT_UNLISTEN_REPLY:
      vcl_session_unlisten_reply_handler (wrk, e->data);
      break;
    case SESSION_CTRL_EVT_REQ_WORKER_UPDATE:
      vcl_session_req_worker_update_handler (wrk, e->data);
      break;
    case SESSION_CTRL_EVT_WORKER_UPDATE_REPLY:
      vcl_session_worker_update_reply_handler (wrk, e->data);
      break;
    default:
      VDBG (0, "unhandled: %u", e->event_type);
      break;
    }

  if (add_event)
    {
      events[*num_ev].data.u64 = session_evt_data;
      if (EPOLLONESHOT & session_events)
	{
	  session = vcl_session_get (wrk, sid);
	  session->vep.ev.events = 0;
	}
      *num_ev += 1;
    }
}

static int
vcl_epoll_wait_handle_mq (vcl_worker_t * wrk, svm_msg_q_t * mq,
			  struct epoll_event *events, u32 maxevents,
			  double wait_for_time, u32 * num_ev)
{
  svm_msg_q_msg_t *msg;
  session_event_t *e;
  int i;

  if (vec_len (wrk->mq_msg_vector) && svm_msg_q_is_empty (mq))
    goto handle_dequeued;

  svm_msg_q_lock (mq);
  if (svm_msg_q_is_empty (mq))
    {
      if (!wait_for_time)
	{
	  svm_msg_q_unlock (mq);
	  return 0;
	}
      else if (wait_for_time < 0)
	{
	  svm_msg_q_wait (mq);
	}
      else
	{
	  if (svm_msg_q_timedwait (mq, wait_for_time / 1e3))
	    {
	      svm_msg_q_unlock (mq);
	      return 0;
	    }
	}
    }
  ASSERT (maxevents > *num_ev);
  vcl_mq_dequeue_batch (wrk, mq, maxevents - *num_ev);
  svm_msg_q_unlock (mq);

handle_dequeued:
  for (i = 0; i < vec_len (wrk->mq_msg_vector); i++)
    {
      msg = vec_elt_at_index (wrk->mq_msg_vector, i);
      e = svm_msg_q_msg_data (mq, msg);
      vcl_epoll_wait_handle_mq_event (wrk, e, events, num_ev);
      svm_msg_q_free_msg (mq, msg);
    }
  vec_reset_length (wrk->mq_msg_vector);
  vcl_handle_pending_wrk_updates (wrk);
  return *num_ev;
}

static int
vppcom_epoll_wait_condvar (vcl_worker_t * wrk, struct epoll_event *events,
			   int maxevents, u32 n_evts, double wait_for_time)
{
  double wait = 0, start = 0, now;

  if (!n_evts)
    {
      wait = wait_for_time;
      start = clib_time_now (&wrk->clib_time);
    }

  do
    {
      vcl_epoll_wait_handle_mq (wrk, wrk->app_event_queue, events, maxevents,
				wait, &n_evts);
      if (n_evts)
	return n_evts;
      if (wait == -1)
	continue;

      now = clib_time_now (&wrk->clib_time);
      wait -= now - start;
      start = now;
    }
  while (wait > 0);

  return 0;
}

static int
vppcom_epoll_wait_eventfd (vcl_worker_t * wrk, struct epoll_event *events,
			   int maxevents, u32 n_evts, double wait_for_time)
{
  vcl_mq_evt_conn_t *mqc;
  int __clib_unused n_read;
  int n_mq_evts, i;
  u64 buf;

  vec_validate (wrk->mq_events, pool_elts (wrk->mq_evt_conns));
again:
  n_mq_evts = epoll_wait (wrk->mqs_epfd, wrk->mq_events,
			  vec_len (wrk->mq_events), wait_for_time);
  for (i = 0; i < n_mq_evts; i++)
    {
      mqc = vcl_mq_evt_conn_get (wrk, wrk->mq_events[i].data.u32);
      n_read = read (mqc->mq_fd, &buf, sizeof (buf));
      vcl_epoll_wait_handle_mq (wrk, mqc->mq, events, maxevents, 0, &n_evts);
    }
  if (!n_evts && n_mq_evts > 0)
    goto again;

  return (int) n_evts;
}

int
vppcom_epoll_wait (uint32_t vep_handle, struct epoll_event *events,
		   int maxevents, double wait_for_time)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *vep_session;
  u32 n_evts = 0;
  int i;

  if (PREDICT_FALSE (maxevents <= 0))
    {
      VDBG (0, "ERROR: Invalid maxevents (%d)!", maxevents);
      return VPPCOM_EINVAL;
    }

  vep_session = vcl_session_get_w_handle (wrk, vep_handle);
  if (!vep_session)
    return VPPCOM_EBADFD;

  if (PREDICT_FALSE (!vep_session->is_vep))
    {
      VDBG (0, "ERROR: vep_idx (%u) is not a vep!", vep_handle);
      return VPPCOM_EINVAL;
    }

  memset (events, 0, sizeof (*events) * maxevents);

  if (vec_len (wrk->unhandled_evts_vector))
    {
      for (i = 0; i < vec_len (wrk->unhandled_evts_vector); i++)
	{
	  vcl_epoll_wait_handle_mq_event (wrk, &wrk->unhandled_evts_vector[i],
					  events, &n_evts);
	  if (n_evts == maxevents)
	    {
	      vec_delete (wrk->unhandled_evts_vector, i + 1, 0);
	      return n_evts;
	    }
	}
      vec_reset_length (wrk->unhandled_evts_vector);
    }

  if (vcm->cfg.use_mq_eventfd)
    return vppcom_epoll_wait_eventfd (wrk, events, maxevents, n_evts,
				      wait_for_time);

  return vppcom_epoll_wait_condvar (wrk, events, maxevents, n_evts,
				    wait_for_time);
}

int
vppcom_session_attr (uint32_t session_handle, uint32_t op,
		     void *buffer, uint32_t * buflen)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session;
  int rv = VPPCOM_OK;
  u32 *flags = buffer, tmp_flags = 0;
  vppcom_endpt_t *ep = buffer;

  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;

  switch (op)
    {
    case VPPCOM_ATTR_GET_NREAD:
      rv = vcl_session_read_ready (session);
      VDBG (2, "VPPCOM_ATTR_GET_NREAD: sh %u, nread = %d", session_handle,
	    rv);
      break;

    case VPPCOM_ATTR_GET_NWRITE:
      rv = vcl_session_write_ready (session);
      VDBG (2, "VPPCOM_ATTR_GET_NWRITE: sh %u, nwrite = %d", session_handle,
	    rv);
      break;

    case VPPCOM_ATTR_GET_FLAGS:
      if (PREDICT_TRUE (buffer && buflen && (*buflen >= sizeof (*flags))))
	{
	  *flags = O_RDWR | (VCL_SESS_ATTR_TEST (session->attr,
						 VCL_SESS_ATTR_NONBLOCK));
	  *buflen = sizeof (*flags);
	  VDBG (2, "VPPCOM_ATTR_GET_FLAGS: sh %u, flags = 0x%08x, "
		"is_nonblocking = %u", session_handle, *flags,
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_NONBLOCK));
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_FLAGS:
      if (PREDICT_TRUE (buffer && buflen && (*buflen == sizeof (*flags))))
	{
	  if (*flags & O_NONBLOCK)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_NONBLOCK);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_NONBLOCK);

	  VDBG (2, "VPPCOM_ATTR_SET_FLAGS: sh %u, flags = 0x%08x,"
		" is_nonblocking = %u", session_handle, *flags,
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_NONBLOCK));
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_PEER_ADDR:
      if (PREDICT_TRUE (buffer && buflen &&
			(*buflen >= sizeof (*ep)) && ep->ip))
	{
	  ep->is_ip4 = session->transport.is_ip4;
	  ep->port = session->transport.rmt_port;
	  if (session->transport.is_ip4)
	    clib_memcpy_fast (ep->ip, &session->transport.rmt_ip.ip4,
			      sizeof (ip4_address_t));
	  else
	    clib_memcpy_fast (ep->ip, &session->transport.rmt_ip.ip6,
			      sizeof (ip6_address_t));
	  *buflen = sizeof (*ep);
	  VDBG (1, "VPPCOM_ATTR_GET_PEER_ADDR: sh %u, is_ip4 = %u, "
		"addr = %U, port %u", session_handle, ep->is_ip4,
		format_ip46_address, &session->transport.rmt_ip,
		ep->is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
		clib_net_to_host_u16 (ep->port));
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_LCL_ADDR:
      if (PREDICT_TRUE (buffer && buflen &&
			(*buflen >= sizeof (*ep)) && ep->ip))
	{
	  ep->is_ip4 = session->transport.is_ip4;
	  ep->port = session->transport.lcl_port;
	  if (session->transport.is_ip4)
	    clib_memcpy_fast (ep->ip, &session->transport.lcl_ip.ip4,
			      sizeof (ip4_address_t));
	  else
	    clib_memcpy_fast (ep->ip, &session->transport.lcl_ip.ip6,
			      sizeof (ip6_address_t));
	  *buflen = sizeof (*ep);
	  VDBG (1, "VPPCOM_ATTR_GET_LCL_ADDR: sh %u, is_ip4 = %u, addr = %U"
		" port %d", session_handle, ep->is_ip4, format_ip46_address,
		&session->transport.lcl_ip,
		ep->is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
		clib_net_to_host_u16 (ep->port));
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_LCL_ADDR:
      if (PREDICT_TRUE (buffer && buflen &&
			(*buflen >= sizeof (*ep)) && ep->ip))
	{
	  session->transport.is_ip4 = ep->is_ip4;
	  session->transport.lcl_port = ep->port;
	  vcl_ip_copy_from_ep (&session->transport.lcl_ip, ep);
	  *buflen = sizeof (*ep);
	  VDBG (1, "VPPCOM_ATTR_SET_LCL_ADDR: sh %u, is_ip4 = %u, addr = %U"
		" port %d", session_handle, ep->is_ip4, format_ip46_address,
		&session->transport.lcl_ip,
		ep->is_ip4 ? IP46_TYPE_IP4 : IP46_TYPE_IP6,
		clib_net_to_host_u16 (ep->port));
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_LIBC_EPFD:
      rv = session->libc_epfd;
      VDBG (2, "VPPCOM_ATTR_GET_LIBC_EPFD: libc_epfd %d", rv);
      break;

    case VPPCOM_ATTR_SET_LIBC_EPFD:
      if (PREDICT_TRUE (buffer && buflen &&
			(*buflen == sizeof (session->libc_epfd))))
	{
	  session->libc_epfd = *(int *) buffer;
	  *buflen = sizeof (session->libc_epfd);

	  VDBG (2, "VPPCOM_ATTR_SET_LIBC_EPFD: libc_epfd %d, buflen %d",
		session->libc_epfd, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_PROTOCOL:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  *(int *) buffer = session->session_type;
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_PROTOCOL: %d (%s), buflen %d",
		*(int *) buffer, *(int *) buffer ? "UDP" : "TCP", *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_LISTEN:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_LISTEN);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_LISTEN: %d, buflen %d", *(int *) buffer,
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_ERROR:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  *(int *) buffer = 0;
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_ERROR: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_TX_FIFO_LEN:
      if (buffer && buflen && (*buflen >= sizeof (u32)))
	{

	  /* VPP-TBD */
	  *(size_t *) buffer = (session->sndbuf_size ? session->sndbuf_size :
				session->tx_fifo ? session->tx_fifo->nitems :
				vcm->cfg.tx_fifo_size);
	  *buflen = sizeof (u32);

	  VDBG (2, "VPPCOM_ATTR_GET_TX_FIFO_LEN: %u (0x%x), buflen %d,"
		" #VPP-TBD#", *(size_t *) buffer, *(size_t *) buffer,
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_TX_FIFO_LEN:
      if (buffer && buflen && (*buflen == sizeof (u32)))
	{
	  /* VPP-TBD */
	  session->sndbuf_size = *(u32 *) buffer;
	  VDBG (2, "VPPCOM_ATTR_SET_TX_FIFO_LEN: %u (0x%x), buflen %d,"
		" #VPP-TBD#", session->sndbuf_size, session->sndbuf_size,
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_RX_FIFO_LEN:
      if (buffer && buflen && (*buflen >= sizeof (u32)))
	{

	  /* VPP-TBD */
	  *(size_t *) buffer = (session->rcvbuf_size ? session->rcvbuf_size :
				session->rx_fifo ? session->rx_fifo->nitems :
				vcm->cfg.rx_fifo_size);
	  *buflen = sizeof (u32);

	  VDBG (2, "VPPCOM_ATTR_GET_RX_FIFO_LEN: %u (0x%x), buflen %d, "
		"#VPP-TBD#", *(size_t *) buffer, *(size_t *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_RX_FIFO_LEN:
      if (buffer && buflen && (*buflen == sizeof (u32)))
	{
	  /* VPP-TBD */
	  session->rcvbuf_size = *(u32 *) buffer;
	  VDBG (2, "VPPCOM_ATTR_SET_RX_FIFO_LEN: %u (0x%x), buflen %d,"
		" #VPP-TBD#", session->sndbuf_size, session->sndbuf_size,
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_REUSEADDR:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_REUSEADDR);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_REUSEADDR: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_REUSEADDR:
      if (buffer && buflen && (*buflen == sizeof (int)) &&
	  !VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_LISTEN))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_REUSEADDR);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_REUSEADDR);

	  VDBG (2, "VPPCOM_ATTR_SET_REUSEADDR: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_REUSEADDR),
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_REUSEPORT:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_REUSEPORT);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_REUSEPORT: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_REUSEPORT:
      if (buffer && buflen && (*buflen == sizeof (int)) &&
	  !VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_LISTEN))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_REUSEPORT);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_REUSEPORT);

	  VDBG (2, "VPPCOM_ATTR_SET_REUSEPORT: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_REUSEPORT),
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_BROADCAST:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_BROADCAST);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_BROADCAST: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_BROADCAST:
      if (buffer && buflen && (*buflen == sizeof (int)))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_BROADCAST);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_BROADCAST);

	  VDBG (2, "VPPCOM_ATTR_SET_BROADCAST: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_BROADCAST),
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_V6ONLY:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_V6ONLY);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_V6ONLY: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_V6ONLY:
      if (buffer && buflen && (*buflen == sizeof (int)))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_V6ONLY);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_V6ONLY);

	  VDBG (2, "VPPCOM_ATTR_SET_V6ONLY: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_V6ONLY),
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_KEEPALIVE:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_KEEPALIVE);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_KEEPALIVE: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_KEEPALIVE:
      if (buffer && buflen && (*buflen == sizeof (int)))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_KEEPALIVE);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_KEEPALIVE);

	  VDBG (2, "VPPCOM_ATTR_SET_KEEPALIVE: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_KEEPALIVE),
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_TCP_NODELAY:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_TCP_NODELAY);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_TCP_NODELAY: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_TCP_NODELAY:
      if (buffer && buflen && (*buflen == sizeof (int)))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_TCP_NODELAY);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_TCP_NODELAY);

	  VDBG (2, "VPPCOM_ATTR_SET_TCP_NODELAY: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_TCP_NODELAY),
		*buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_TCP_KEEPIDLE:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_TCP_KEEPIDLE);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_TCP_KEEPIDLE: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_TCP_KEEPIDLE:
      if (buffer && buflen && (*buflen == sizeof (int)))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_TCP_KEEPIDLE);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_TCP_KEEPIDLE);

	  VDBG (2, "VPPCOM_ATTR_SET_TCP_KEEPIDLE: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr,
				    VCL_SESS_ATTR_TCP_KEEPIDLE), *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_TCP_KEEPINTVL:
      if (buffer && buflen && (*buflen >= sizeof (int)))
	{
	  /* VPP-TBD */
	  *(int *) buffer = VCL_SESS_ATTR_TEST (session->attr,
						VCL_SESS_ATTR_TCP_KEEPINTVL);
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_TCP_KEEPINTVL: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_TCP_KEEPINTVL:
      if (buffer && buflen && (*buflen == sizeof (int)))
	{
	  /* VPP-TBD */
	  if (*(int *) buffer)
	    VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_TCP_KEEPINTVL);
	  else
	    VCL_SESS_ATTR_CLR (session->attr, VCL_SESS_ATTR_TCP_KEEPINTVL);

	  VDBG (2, "VPPCOM_ATTR_SET_TCP_KEEPINTVL: %d, buflen %d, #VPP-TBD#",
		VCL_SESS_ATTR_TEST (session->attr,
				    VCL_SESS_ATTR_TCP_KEEPINTVL), *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_GET_TCP_USER_MSS:
      if (buffer && buflen && (*buflen >= sizeof (u32)))
	{
	  /* VPP-TBD */
	  *(u32 *) buffer = session->user_mss;
	  *buflen = sizeof (int);

	  VDBG (2, "VPPCOM_ATTR_GET_TCP_USER_MSS: %d, buflen %d, #VPP-TBD#",
		*(int *) buffer, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_TCP_USER_MSS:
      if (buffer && buflen && (*buflen == sizeof (u32)))
	{
	  /* VPP-TBD */
	  session->user_mss = *(u32 *) buffer;

	  VDBG (2, "VPPCOM_ATTR_SET_TCP_USER_MSS: %u, buflen %d, #VPP-TBD#",
		session->user_mss, *buflen);
	}
      else
	rv = VPPCOM_EINVAL;
      break;

    case VPPCOM_ATTR_SET_SHUT:
      if (*flags == SHUT_RD || *flags == SHUT_RDWR)
	VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_SHUT_RD);
      if (*flags == SHUT_WR || *flags == SHUT_RDWR)
	VCL_SESS_ATTR_SET (session->attr, VCL_SESS_ATTR_SHUT_WR);
      break;

    case VPPCOM_ATTR_GET_SHUT:
      if (VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_SHUT_RD))
	tmp_flags = 1;
      if (VCL_SESS_ATTR_TEST (session->attr, VCL_SESS_ATTR_SHUT_WR))
	tmp_flags |= 2;
      if (tmp_flags == 1)
	*(int *) buffer = SHUT_RD;
      else if (tmp_flags == 2)
	*(int *) buffer = SHUT_WR;
      else if (tmp_flags == 3)
	*(int *) buffer = SHUT_RDWR;
      *buflen = sizeof (int);
      break;
    default:
      rv = VPPCOM_EINVAL;
      break;
    }

  return rv;
}

int
vppcom_session_recvfrom (uint32_t session_handle, void *buffer,
			 uint32_t buflen, int flags, vppcom_endpt_t * ep)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  int rv = VPPCOM_OK;
  vcl_session_t *session = 0;

  if (ep)
    {
      session = vcl_session_get_w_handle (wrk, session_handle);
      if (PREDICT_FALSE (!session))
	{
	  VDBG (0, "sh 0x%llx is closed!", session_handle);
	  return VPPCOM_EBADFD;
	}
      ep->is_ip4 = session->transport.is_ip4;
      ep->port = session->transport.rmt_port;
    }

  if (flags == 0)
    rv = vppcom_session_read (session_handle, buffer, buflen);
  else if (flags & MSG_PEEK)
    rv = vppcom_session_peek (session_handle, buffer, buflen);
  else
    {
      VDBG (0, "Unsupport flags for recvfrom %d", flags);
      return VPPCOM_EAFNOSUPPORT;
    }

  if (ep)
    {
      if (session->transport.is_ip4)
	clib_memcpy_fast (ep->ip, &session->transport.rmt_ip.ip4,
			  sizeof (ip4_address_t));
      else
	clib_memcpy_fast (ep->ip, &session->transport.rmt_ip.ip6,
			  sizeof (ip6_address_t));
    }

  return rv;
}

int
vppcom_session_sendto (uint32_t session_handle, void *buffer,
		       uint32_t buflen, int flags, vppcom_endpt_t * ep)
{
  if (!buffer)
    return VPPCOM_EINVAL;

  if (ep)
    {
      // TBD
      return VPPCOM_EINVAL;
    }

  if (flags)
    {
      // TBD check the flags and do the right thing
      VDBG (2, "handling flags 0x%u (%d) not implemented yet.", flags, flags);
    }

  return (vppcom_session_write_inline (session_handle, buffer, buflen, 1));
}

int
vppcom_poll (vcl_poll_t * vp, uint32_t n_sids, double wait_for_time)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  f64 timeout = clib_time_now (&wrk->clib_time) + wait_for_time;
  u32 i, keep_trying = 1;
  svm_msg_q_msg_t msg;
  session_event_t *e;
  int rv, num_ev = 0;

  VDBG (3, "vp %p, nsids %u, wait_for_time %f", vp, n_sids, wait_for_time);

  if (!vp)
    return VPPCOM_EFAULT;

  do
    {
      vcl_session_t *session;

      /* Dequeue all events and drop all unhandled io events */
      while (svm_msg_q_sub (wrk->app_event_queue, &msg, SVM_Q_NOWAIT, 0) == 0)
	{
	  e = svm_msg_q_msg_data (wrk->app_event_queue, &msg);
	  vcl_handle_mq_event (wrk, e);
	  svm_msg_q_free_msg (wrk->app_event_queue, &msg);
	}
      vec_reset_length (wrk->unhandled_evts_vector);

      for (i = 0; i < n_sids; i++)
	{
	  session = vcl_session_get (wrk, vp[i].sh);
	  if (!session)
	    {
	      vp[i].revents = POLLHUP;
	      num_ev++;
	      continue;
	    }

	  vp[i].revents = 0;

	  if (POLLIN & vp[i].events)
	    {
	      rv = vcl_session_read_ready (session);
	      if (rv > 0)
		{
		  vp[i].revents |= POLLIN;
		  num_ev++;
		}
	      else if (rv < 0)
		{
		  switch (rv)
		    {
		    case VPPCOM_ECONNRESET:
		      vp[i].revents = POLLHUP;
		      break;

		    default:
		      vp[i].revents = POLLERR;
		      break;
		    }
		  num_ev++;
		}
	    }

	  if (POLLOUT & vp[i].events)
	    {
	      rv = vcl_session_write_ready (session);
	      if (rv > 0)
		{
		  vp[i].revents |= POLLOUT;
		  num_ev++;
		}
	      else if (rv < 0)
		{
		  switch (rv)
		    {
		    case VPPCOM_ECONNRESET:
		      vp[i].revents = POLLHUP;
		      break;

		    default:
		      vp[i].revents = POLLERR;
		      break;
		    }
		  num_ev++;
		}
	    }

	  if (0)		// Note "done:" label used by VCL_SESSION_LOCK_AND_GET()
	    {
	      vp[i].revents = POLLNVAL;
	      num_ev++;
	    }
	}
      if (wait_for_time != -1)
	keep_trying = (clib_time_now (&wrk->clib_time) <= timeout) ? 1 : 0;
    }
  while ((num_ev == 0) && keep_trying);

  return num_ev;
}

int
vppcom_mq_epoll_fd (void)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  return wrk->mqs_epfd;
}

int
vppcom_session_index (vcl_session_handle_t session_handle)
{
  return session_handle & 0xFFFFFF;
}

int
vppcom_session_worker (vcl_session_handle_t session_handle)
{
  return session_handle >> 24;
}

int
vppcom_worker_register (void)
{
  if (!vcl_worker_alloc_and_init ())
    return VPPCOM_EEXIST;

  if (vcl_worker_set_bapi ())
    return VPPCOM_EEXIST;

  if (vcl_worker_register_with_vpp ())
    return VPPCOM_EEXIST;

  return VPPCOM_OK;
}

void
vppcom_worker_unregister (void)
{
  vcl_worker_cleanup (vcl_worker_get_current (), 1 /* notify vpp */ );
  vcl_set_worker_index (~0);
}

int
vppcom_worker_index (void)
{
  return vcl_get_worker_index ();
}

int
vppcom_worker_mqs_epfd (void)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  if (!vcm->cfg.use_mq_eventfd)
    return -1;
  return wrk->mqs_epfd;
}

int
vppcom_session_is_connectable_listener (uint32_t session_handle)
{
  vcl_session_t *session;
  vcl_worker_t *wrk = vcl_worker_get_current ();
  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;
  return vcl_session_is_connectable_listener (wrk, session);
}

int
vppcom_session_listener (uint32_t session_handle)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *listen_session, *session;
  session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;
  if (session->listener_index == VCL_INVALID_SESSION_INDEX)
    return VPPCOM_EBADFD;
  listen_session = vcl_session_get_w_handle (wrk, session->listener_index);
  if (!listen_session)
    return VPPCOM_EBADFD;
  return vcl_session_handle (listen_session);
}

int
vppcom_session_n_accepted (uint32_t session_handle)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  vcl_session_t *session = vcl_session_get_w_handle (wrk, session_handle);
  if (!session)
    return VPPCOM_EBADFD;
  return session->n_accepted_sessions;
}

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