vnet/vnet/pg/stream.c - fdio/vpp - Gitiles

 /*
  * 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.
  */
 /*
  * pg_stream.c: packet generator streams
  *
  * Copyright (c) 2008 Eliot Dresselhaus
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sublicense, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */

 #include <vnet/vnet.h>
 #include <vnet/pg/pg.h>

 /* Mark stream active or inactive. */
 void pg_stream_enable_disable (pg_main_t * pg, pg_stream_t * s, int want_enabled)
 {
   vnet_main_t * vnm = vnet_get_main();
   pg_interface_t * pi = vec_elt_at_index (pg->interfaces, s->pg_if_index);

   want_enabled = want_enabled != 0;

   if (pg_stream_is_enabled (s) == want_enabled)
     /* No change necessary. */
     return;

   if (want_enabled)
     s->n_packets_generated = 0;

   /* Toggle enabled flag. */
   s->flags ^= PG_STREAM_FLAGS_IS_ENABLED;

   ASSERT (! pool_is_free (pg->streams, s));

   pg->enabled_streams
     = clib_bitmap_set (pg->enabled_streams, s - pg->streams, want_enabled);

   vnet_hw_interface_set_flags (vnm, pi->hw_if_index,
 			       (want_enabled
 				? VNET_HW_INTERFACE_FLAG_LINK_UP
 				: 0));

   vnet_sw_interface_set_flags (vnm, pi->sw_if_index,
 			       (want_enabled
 				? VNET_SW_INTERFACE_FLAG_ADMIN_UP
 				: 0));

   vlib_node_set_state (pg->vlib_main,
 		       pg_input_node.index,
 		       (clib_bitmap_is_zero (pg->enabled_streams)
 			? VLIB_NODE_STATE_DISABLED
 			: VLIB_NODE_STATE_POLLING));

   s->packet_accumulator = 0;
   s->time_last_generate = 0;
 }

 static u8 * format_pg_interface_name (u8 * s, va_list * args)
 {
   pg_main_t * pg = &pg_main;
   u32 if_index = va_arg (*args, u32);
   pg_interface_t * pi;

   pi = vec_elt_at_index (pg->interfaces, if_index);
   s = format (s, "pg/stream-%d", pi->stream_index);

   return s;
 }

 VNET_DEVICE_CLASS (pg_dev_class,static) = {
   .name = "pg",
   .tx_function = pg_output,
   .format_device_name = format_pg_interface_name,
 };

 static uword pg_set_rewrite (vnet_main_t * vnm,
 			     u32 sw_if_index,
 			     u32 l3_type,
 			     void * dst_address,
 			     void * rewrite,
 			     uword max_rewrite_bytes)
 {
   u16 * h = rewrite;

   if (max_rewrite_bytes < sizeof (h[0]))
     return 0;

   h[0] = clib_host_to_net_u16 (l3_type);
   return sizeof (h[0]);
 }

 VNET_HW_INTERFACE_CLASS (pg_interface_class,static) = {
   .name = "Packet generator",
   .set_rewrite = pg_set_rewrite,
 };

 u32 pg_interface_find_free (pg_main_t * pg, uword stream_index)
 {
   vnet_main_t * vnm = vnet_get_main();
   pg_interface_t * pi;
   vnet_hw_interface_t * hi;
   u32 i, l;

   if ((l = vec_len (pg->free_interfaces)) > 0)
     {
       i = pg->free_interfaces[l - 1];
       _vec_len (pg->free_interfaces) = l - 1;
       pi = vec_elt_at_index (pg->interfaces, i);
       pi->stream_index = stream_index;
     }
   else
     {
       i = vec_len (pg->interfaces);
       vec_add2 (pg->interfaces, pi, 1);

       pi->stream_index = stream_index;
       pi->hw_if_index = vnet_register_interface (vnm,
 						 pg_dev_class.index, i,
 						 pg_interface_class.index, stream_index);
       hi = vnet_get_hw_interface (vnm, pi->hw_if_index);
       pi->sw_if_index = hi->sw_if_index;
     }

   return i;
 }

 static void do_edit (pg_stream_t * stream,
 		     pg_edit_group_t * g,
 		     pg_edit_t * e,
 		     uword want_commit)
 {
   u32 i, i0, i1, mask, n_bits_left;
   u8 * v, * s, * m;

   i0 = e->lsb_bit_offset / BITS (u8);

   /* Make space for edit in value and mask. */
   vec_validate (g->fixed_packet_data, i0);
   vec_validate (g->fixed_packet_data_mask, i0);

   if (e->type != PG_EDIT_FIXED)
     {
       switch (e->type)
 	{
 	case PG_EDIT_RANDOM:
 	case PG_EDIT_INCREMENT:
 	  e->last_increment_value = pg_edit_get_value (e, PG_EDIT_LO);
 	  break;

 	default:
 	  break;
 	}

       if (want_commit)
         {
           ASSERT(e->type != PG_EDIT_INVALID_TYPE);
           vec_add1 (g->non_fixed_edits, e[0]);
         }
       return;
     }

   s = g->fixed_packet_data;
   m = g->fixed_packet_data_mask;

   n_bits_left = e->n_bits;
   i0 = e->lsb_bit_offset / BITS (u8);
   i1 = e->lsb_bit_offset % BITS (u8);

   v = e->values[PG_EDIT_LO];
   i = pg_edit_n_alloc_bytes (e) - 1;

   /* Odd low order bits?. */
   if (i1 != 0 && n_bits_left > 0)
     {
       u32 n = clib_min (n_bits_left, BITS (u8) - i1);

       mask = pow2_mask (n) << i1;

       ASSERT (i0 < vec_len (s));
       ASSERT (i < vec_len (v));
       ASSERT ((v[i] &~ mask) == 0);

       s[i0] |= v[i] & mask;
       m[i0] |= mask;

       i0--;
       i--;
       n_bits_left -= n;
     }

   /* Even bytes. */
   while (n_bits_left >= 8)
     {
       ASSERT (i0 < vec_len (s));
       ASSERT (i < vec_len (v));

       s[i0] = v[i];
       m[i0] = ~0;

       i0--;
       i--;
       n_bits_left -= 8;
     }

   /* Odd high order bits. */
   if (n_bits_left > 0)
     {
       mask = pow2_mask (n_bits_left);

       ASSERT (i0 < vec_len (s));
       ASSERT (i < vec_len (v));
       ASSERT ((v[i] &~ mask) == 0);

       s[i0] |= v[i] & mask;
       m[i0] |= mask;
     }

   if (want_commit)
     pg_edit_free (e);
 }

 void pg_edit_group_get_fixed_packet_data (pg_stream_t * s,
 					  u32 group_index,
 					  void * packet_data,
 					  void * packet_data_mask)
 {
   pg_edit_group_t * g = pg_stream_get_group (s, group_index);
   pg_edit_t * e;

   vec_foreach (e, g->edits)
     do_edit (s, g, e, /* want_commit */ 0);

   memcpy (packet_data, g->fixed_packet_data, vec_len (g->fixed_packet_data));
   memcpy (packet_data_mask, g->fixed_packet_data_mask, vec_len (g->fixed_packet_data_mask));
 }

 static void perform_fixed_edits (pg_stream_t * s)
 {
   pg_edit_group_t * g;
   pg_edit_t * e;
   word i;

   for (i = vec_len (s->edit_groups) - 1; i >= 0; i--)
     {
       g = vec_elt_at_index (s->edit_groups, i);
       vec_foreach (e, g->edits)
 	do_edit (s, g, e, /* want_commit */ 1);

       /* All edits have either been performed or added to
 	 g->non_fixed_edits.  So, we can delete the vector. */
       vec_free (g->edits);
     }

   vec_free (s->fixed_packet_data_mask);
   vec_free (s->fixed_packet_data);
   vec_foreach (g, s->edit_groups)
     {
       int i;
       g->start_byte_offset = vec_len (s->fixed_packet_data);

       /* Relocate and copy non-fixed edits from group to stream. */
       vec_foreach (e, g->non_fixed_edits)
 	e->lsb_bit_offset += g->start_byte_offset * BITS (u8);

       for (i = 0; i < vec_len (g->non_fixed_edits); i++)
         ASSERT(g->non_fixed_edits[i].type != PG_EDIT_INVALID_TYPE);

       vec_add (s->non_fixed_edits,
 	       g->non_fixed_edits,
 	       vec_len (g->non_fixed_edits));
       vec_free (g->non_fixed_edits);

       vec_add (s->fixed_packet_data,
 	       g->fixed_packet_data,
 	       vec_len (g->fixed_packet_data));
       vec_add (s->fixed_packet_data_mask,
 	       g->fixed_packet_data_mask,
 	       vec_len (g->fixed_packet_data_mask));
     }
 }

 void pg_stream_add (pg_main_t * pg, pg_stream_t * s_init)
 {
   vlib_main_t * vm = pg->vlib_main;
   pg_stream_t * s;
   uword * p;

   if (! pg->stream_index_by_name)
     pg->stream_index_by_name
       = hash_create_vec (0, sizeof (s->name[0]), sizeof (uword));

   /* Delete any old stream with the same name. */
   if (s_init->name
       && (p = hash_get_mem (pg->stream_index_by_name, s_init->name)))
     {
       pg_stream_del (pg, p[0]);
     }

   pool_get (pg->streams, s);
   s[0] = s_init[0];

   /* Give it a name. */
   if (! s->name)
     s->name = format (0, "stream%d", s - pg->streams);
   else
     s->name = vec_dup (s->name);

   hash_set_mem (pg->stream_index_by_name, s->name, s - pg->streams);

   /* Get fixed part of buffer data. */
   perform_fixed_edits (s);

   /* Determine packet size. */
   switch (s->packet_size_edit_type)
     {
     case PG_EDIT_INCREMENT:
     case PG_EDIT_RANDOM:
       if (s->min_packet_bytes == s->max_packet_bytes)
 	s->packet_size_edit_type = PG_EDIT_FIXED;
       break;

     default:
       /* Get packet size from fixed edits. */
       s->packet_size_edit_type = PG_EDIT_FIXED;
       if (! s->replay_packet_templates)
 	s->min_packet_bytes = s->max_packet_bytes = vec_len (s->fixed_packet_data);
       break;
     }

   s->last_increment_packet_size = s->min_packet_bytes;

   {
     pg_buffer_index_t * bi;
     int n;

     if (! s->buffer_bytes)
       s->buffer_bytes = s->max_packet_bytes;

     s->buffer_bytes = vlib_buffer_round_size (s->buffer_bytes);

     n = s->max_packet_bytes / s->buffer_bytes;
     n += (s->max_packet_bytes % s->buffer_bytes) != 0;

     vec_resize (s->buffer_indices, n);

     vec_foreach (bi, s->buffer_indices)
       bi->free_list_index = vlib_buffer_create_free_list (vm, s->buffer_bytes,
 							  "pg stream %d buffer #%d",
 							  s - pg->streams,
 							  1 + (bi - s->buffer_indices));
   }

   /* Find an interface to use. */
   s->pg_if_index = pg_interface_find_free (pg, s - pg->streams);

   {
     pg_interface_t * pi = vec_elt_at_index (pg->interfaces, s->pg_if_index);
     vlib_rx_or_tx_t rx_or_tx;

     vlib_foreach_rx_tx (rx_or_tx)
       {
 	if (s->sw_if_index[rx_or_tx] == ~0)
 	  s->sw_if_index[rx_or_tx] = pi->sw_if_index;
       }
   }

   /* Connect the graph. */
   s->next_index = vlib_node_add_next (vm, pg_input_node.index, s->node_index);
 }

 void pg_stream_del (pg_main_t * pg, uword index)
 {
   vlib_main_t * vm = pg->vlib_main;
   pg_stream_t * s;
   pg_buffer_index_t * bi;

   s = pool_elt_at_index (pg->streams, index);

   pg_stream_enable_disable (pg, s, /* want_enabled */ 0);
   vec_add1 (pg->free_interfaces, s->pg_if_index);
   hash_unset_mem (pg->stream_index_by_name, s->name);

   vec_foreach (bi, s->buffer_indices)
     {
       vlib_buffer_delete_free_list (vm, bi->free_list_index);
       clib_fifo_free (bi->buffer_fifo);
     }

   pg_stream_free (s);
   pool_put (pg->streams, s);
 }
	/*
	* 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.
	*/
	/*
	* pg_stream.c: packet generator streams
	*
	* Copyright (c) 2008 Eliot Dresselhaus
	*
	* Permission is hereby granted, free of charge, to any person obtaining
	* a copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sublicense, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice shall be
	* included in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
	* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
	* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
	* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/

	#include <vnet/vnet.h>
	#include <vnet/pg/pg.h>

	/* Mark stream active or inactive. */
	void pg_stream_enable_disable (pg_main_t * pg, pg_stream_t * s, int want_enabled)
	{
	vnet_main_t * vnm = vnet_get_main();
	pg_interface_t * pi = vec_elt_at_index (pg->interfaces, s->pg_if_index);

	want_enabled = want_enabled != 0;

	if (pg_stream_is_enabled (s) == want_enabled)
	/* No change necessary. */
	return;

	if (want_enabled)
	s->n_packets_generated = 0;

	/* Toggle enabled flag. */
	s->flags ^= PG_STREAM_FLAGS_IS_ENABLED;

	ASSERT (! pool_is_free (pg->streams, s));

	pg->enabled_streams
	= clib_bitmap_set (pg->enabled_streams, s - pg->streams, want_enabled);

	vnet_hw_interface_set_flags (vnm, pi->hw_if_index,
	(want_enabled
	? VNET_HW_INTERFACE_FLAG_LINK_UP
	: 0));

	vnet_sw_interface_set_flags (vnm, pi->sw_if_index,
	(want_enabled
	? VNET_SW_INTERFACE_FLAG_ADMIN_UP
	: 0));

	vlib_node_set_state (pg->vlib_main,
	pg_input_node.index,
	(clib_bitmap_is_zero (pg->enabled_streams)
	? VLIB_NODE_STATE_DISABLED
	: VLIB_NODE_STATE_POLLING));

	s->packet_accumulator = 0;
	s->time_last_generate = 0;
	}

	static u8 * format_pg_interface_name (u8 * s, va_list * args)
	{
	pg_main_t * pg = &pg_main;
	u32 if_index = va_arg (*args, u32);
	pg_interface_t * pi;

	pi = vec_elt_at_index (pg->interfaces, if_index);
	s = format (s, "pg/stream-%d", pi->stream_index);

	return s;
	}

	VNET_DEVICE_CLASS (pg_dev_class,static) = {
	.name = "pg",
	.tx_function = pg_output,
	.format_device_name = format_pg_interface_name,
	};

	static uword pg_set_rewrite (vnet_main_t * vnm,
	u32 sw_if_index,
	u32 l3_type,
	void * dst_address,
	void * rewrite,
	uword max_rewrite_bytes)
	{
	u16 * h = rewrite;

	if (max_rewrite_bytes < sizeof (h[0]))
	return 0;

	h[0] = clib_host_to_net_u16 (l3_type);
	return sizeof (h[0]);
	}

	VNET_HW_INTERFACE_CLASS (pg_interface_class,static) = {
	.name = "Packet generator",
	.set_rewrite = pg_set_rewrite,
	};

	u32 pg_interface_find_free (pg_main_t * pg, uword stream_index)
	{
	vnet_main_t * vnm = vnet_get_main();
	pg_interface_t * pi;
	vnet_hw_interface_t * hi;
	u32 i, l;

	if ((l = vec_len (pg->free_interfaces)) > 0)
	{
	i = pg->free_interfaces[l - 1];
	_vec_len (pg->free_interfaces) = l - 1;
	pi = vec_elt_at_index (pg->interfaces, i);
	pi->stream_index = stream_index;
	}
	else
	{
	i = vec_len (pg->interfaces);
	vec_add2 (pg->interfaces, pi, 1);

	pi->stream_index = stream_index;
	pi->hw_if_index = vnet_register_interface (vnm,
	pg_dev_class.index, i,
	pg_interface_class.index, stream_index);
	hi = vnet_get_hw_interface (vnm, pi->hw_if_index);
	pi->sw_if_index = hi->sw_if_index;
	}

	return i;
	}

	static void do_edit (pg_stream_t * stream,
	pg_edit_group_t * g,
	pg_edit_t * e,
	uword want_commit)
	{
	u32 i, i0, i1, mask, n_bits_left;
	u8 * v, * s, * m;

	i0 = e->lsb_bit_offset / BITS (u8);

	/* Make space for edit in value and mask. */
	vec_validate (g->fixed_packet_data, i0);
	vec_validate (g->fixed_packet_data_mask, i0);

	if (e->type != PG_EDIT_FIXED)
	{
	switch (e->type)
	{
	case PG_EDIT_RANDOM:
	case PG_EDIT_INCREMENT:
	e->last_increment_value = pg_edit_get_value (e, PG_EDIT_LO);
	break;

	default:
	break;
	}

	if (want_commit)
	{
	ASSERT(e->type != PG_EDIT_INVALID_TYPE);
	vec_add1 (g->non_fixed_edits, e[0]);
	}
	return;
	}

	s = g->fixed_packet_data;
	m = g->fixed_packet_data_mask;

	n_bits_left = e->n_bits;
	i0 = e->lsb_bit_offset / BITS (u8);
	i1 = e->lsb_bit_offset % BITS (u8);

	v = e->values[PG_EDIT_LO];
	i = pg_edit_n_alloc_bytes (e) - 1;

	/* Odd low order bits?. */
	if (i1 != 0 && n_bits_left > 0)
	{
	u32 n = clib_min (n_bits_left, BITS (u8) - i1);

	mask = pow2_mask (n) << i1;

	ASSERT (i0 < vec_len (s));
	ASSERT (i < vec_len (v));
	ASSERT ((v[i] &~ mask) == 0);

	s[i0] \|= v[i] & mask;
	m[i0] \|= mask;

	i0--;
	i--;
	n_bits_left -= n;
	}

	/* Even bytes. */
	while (n_bits_left >= 8)
	{
	ASSERT (i0 < vec_len (s));
	ASSERT (i < vec_len (v));

	s[i0] = v[i];
	m[i0] = ~0;

	i0--;
	i--;
	n_bits_left -= 8;
	}

	/* Odd high order bits. */
	if (n_bits_left > 0)
	{
	mask = pow2_mask (n_bits_left);

	ASSERT (i0 < vec_len (s));
	ASSERT (i < vec_len (v));
	ASSERT ((v[i] &~ mask) == 0);

	s[i0] \|= v[i] & mask;
	m[i0] \|= mask;
	}

	if (want_commit)
	pg_edit_free (e);
	}

	void pg_edit_group_get_fixed_packet_data (pg_stream_t * s,
	u32 group_index,
	void * packet_data,
	void * packet_data_mask)
	{
	pg_edit_group_t * g = pg_stream_get_group (s, group_index);
	pg_edit_t * e;

	vec_foreach (e, g->edits)
	do_edit (s, g, e, /* want_commit */ 0);

	memcpy (packet_data, g->fixed_packet_data, vec_len (g->fixed_packet_data));
	memcpy (packet_data_mask, g->fixed_packet_data_mask, vec_len (g->fixed_packet_data_mask));
	}

	static void perform_fixed_edits (pg_stream_t * s)
	{
	pg_edit_group_t * g;
	pg_edit_t * e;
	word i;

	for (i = vec_len (s->edit_groups) - 1; i >= 0; i--)
	{
	g = vec_elt_at_index (s->edit_groups, i);
	vec_foreach (e, g->edits)
	do_edit (s, g, e, /* want_commit */ 1);

	/* All edits have either been performed or added to
	g->non_fixed_edits. So, we can delete the vector. */
	vec_free (g->edits);
	}

	vec_free (s->fixed_packet_data_mask);
	vec_free (s->fixed_packet_data);
	vec_foreach (g, s->edit_groups)
	{
	int i;
	g->start_byte_offset = vec_len (s->fixed_packet_data);

	/* Relocate and copy non-fixed edits from group to stream. */
	vec_foreach (e, g->non_fixed_edits)
	e->lsb_bit_offset += g->start_byte_offset * BITS (u8);

	for (i = 0; i < vec_len (g->non_fixed_edits); i++)
	ASSERT(g->non_fixed_edits[i].type != PG_EDIT_INVALID_TYPE);

	vec_add (s->non_fixed_edits,
	g->non_fixed_edits,
	vec_len (g->non_fixed_edits));
	vec_free (g->non_fixed_edits);

	vec_add (s->fixed_packet_data,
	g->fixed_packet_data,
	vec_len (g->fixed_packet_data));
	vec_add (s->fixed_packet_data_mask,
	g->fixed_packet_data_mask,
	vec_len (g->fixed_packet_data_mask));
	}
	}

	void pg_stream_add (pg_main_t * pg, pg_stream_t * s_init)
	{
	vlib_main_t * vm = pg->vlib_main;
	pg_stream_t * s;
	uword * p;

	if (! pg->stream_index_by_name)
	pg->stream_index_by_name
	= hash_create_vec (0, sizeof (s->name[0]), sizeof (uword));

	/* Delete any old stream with the same name. */
	if (s_init->name
	&& (p = hash_get_mem (pg->stream_index_by_name, s_init->name)))
	{
	pg_stream_del (pg, p[0]);
	}

	pool_get (pg->streams, s);
	s[0] = s_init[0];

	/* Give it a name. */
	if (! s->name)
	s->name = format (0, "stream%d", s - pg->streams);
	else
	s->name = vec_dup (s->name);

	hash_set_mem (pg->stream_index_by_name, s->name, s - pg->streams);

	/* Get fixed part of buffer data. */
	perform_fixed_edits (s);

	/* Determine packet size. */
	switch (s->packet_size_edit_type)
	{
	case PG_EDIT_INCREMENT:
	case PG_EDIT_RANDOM:
	if (s->min_packet_bytes == s->max_packet_bytes)
	s->packet_size_edit_type = PG_EDIT_FIXED;
	break;

	default:
	/* Get packet size from fixed edits. */
	s->packet_size_edit_type = PG_EDIT_FIXED;
	if (! s->replay_packet_templates)
	s->min_packet_bytes = s->max_packet_bytes = vec_len (s->fixed_packet_data);
	break;
	}

	s->last_increment_packet_size = s->min_packet_bytes;

	{
	pg_buffer_index_t * bi;
	int n;

	if (! s->buffer_bytes)
	s->buffer_bytes = s->max_packet_bytes;

	s->buffer_bytes = vlib_buffer_round_size (s->buffer_bytes);

	n = s->max_packet_bytes / s->buffer_bytes;
	n += (s->max_packet_bytes % s->buffer_bytes) != 0;

	vec_resize (s->buffer_indices, n);

	vec_foreach (bi, s->buffer_indices)
	bi->free_list_index = vlib_buffer_create_free_list (vm, s->buffer_bytes,
	"pg stream %d buffer #%d",
	s - pg->streams,
	1 + (bi - s->buffer_indices));
	}

	/* Find an interface to use. */
	s->pg_if_index = pg_interface_find_free (pg, s - pg->streams);

	{
	pg_interface_t * pi = vec_elt_at_index (pg->interfaces, s->pg_if_index);
	vlib_rx_or_tx_t rx_or_tx;

	vlib_foreach_rx_tx (rx_or_tx)
	{
	if (s->sw_if_index[rx_or_tx] == ~0)
	s->sw_if_index[rx_or_tx] = pi->sw_if_index;
	}
	}

	/* Connect the graph. */
	s->next_index = vlib_node_add_next (vm, pg_input_node.index, s->node_index);
	}

	void pg_stream_del (pg_main_t * pg, uword index)
	{
	vlib_main_t * vm = pg->vlib_main;
	pg_stream_t * s;
	pg_buffer_index_t * bi;

	s = pool_elt_at_index (pg->streams, index);

	pg_stream_enable_disable (pg, s, /* want_enabled */ 0);
	vec_add1 (pg->free_interfaces, s->pg_if_index);
	hash_unset_mem (pg->stream_index_by_name, s->name);

	vec_foreach (bi, s->buffer_indices)
	{
	vlib_buffer_delete_free_list (vm, bi->free_list_index);
	clib_fifo_free (bi->buffer_fifo);
	}

	pg_stream_free (s);
	pool_put (pg->streams, s);
	}