src/vnet/tcp/builtin_server.c - fdio/vpp - Gitiles

 /*
 * Copyright (c) 2015-2017 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

 #include <vnet/vnet.h>
 #include <vlibmemory/api.h>
 #include <vnet/session/application.h>
 #include <vnet/session/application_interface.h>

 typedef struct
 {
   /*
    * Server app parameters
    */
   unix_shared_memory_queue_t **vpp_queue;
   unix_shared_memory_queue_t *vl_input_queue;	/**< Sever's event queue */

   u32 app_index;		/**< Server app index */
   u32 my_client_index;		/**< API client handle */
   u32 node_index;		/**< process node index for evnt scheduling */

   /*
    * Config params
    */
   u8 no_echo;			/**< Don't echo traffic */
   u32 fifo_size;			/**< Fifo size */
   u32 rcv_buffer_size;		/**< Rcv buffer size */
   u32 prealloc_fifos;		/**< Preallocate fifos */
   u32 private_segment_count;	/**< Number of private segments  */
   u32 private_segment_size;	/**< Size of private segments  */
   char *server_uri;		/**< Server URI */

   /*
    * Test state
    */
   u8 **rx_buf;			/**< Per-thread RX buffer */
   u64 byte_index;
   u32 **rx_retries;

   vlib_main_t *vlib_main;
 } builtin_server_main_t;

 builtin_server_main_t builtin_server_main;

 int
 builtin_session_accept_callback (stream_session_t * s)
 {
   builtin_server_main_t *bsm = &builtin_server_main;

   bsm->vpp_queue[s->thread_index] =
     session_manager_get_vpp_event_queue (s->thread_index);
   s->session_state = SESSION_STATE_READY;
   bsm->byte_index = 0;
   vec_validate (bsm->rx_retries[s->thread_index], s->session_index);
   bsm->rx_retries[s->thread_index][s->session_index] = 0;
   return 0;
 }

 void
 builtin_session_disconnect_callback (stream_session_t * s)
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   vnet_disconnect_args_t _a, *a = &_a;

   a->handle = session_handle (s);
   a->app_index = bsm->app_index;
   vnet_disconnect_session (a);
 }

 void
 builtin_session_reset_callback (stream_session_t * s)
 {
   clib_warning ("Reset session %U", format_stream_session, s, 2);
   stream_session_cleanup (s);
 }


 int
 builtin_session_connected_callback (u32 app_index, u32 api_context,
 				    stream_session_t * s, u8 is_fail)
 {
   clib_warning ("called...");
   return -1;
 }

 int
 builtin_add_segment_callback (u32 client_index,
 			      const u8 * seg_name, u32 seg_size)
 {
   clib_warning ("called...");
   return -1;
 }

 int
 builtin_redirect_connect_callback (u32 client_index, void *mp)
 {
   clib_warning ("called...");
   return -1;
 }

 void
 test_bytes (builtin_server_main_t * bsm, int actual_transfer)
 {
   int i;
   u32 my_thread_id = vlib_get_thread_index ();

   for (i = 0; i < actual_transfer; i++)
     {
       if (bsm->rx_buf[my_thread_id][i] != ((bsm->byte_index + i) & 0xff))
 	{
 	  clib_warning ("at %lld expected %d got %d", bsm->byte_index + i,
 			(bsm->byte_index + i) & 0xff,
 			bsm->rx_buf[my_thread_id][i]);
 	}
     }
   bsm->byte_index += actual_transfer;
 }

 /*
  * If no-echo, just read the data and be done with it
  */
 int
 builtin_server_rx_callback_no_echo (stream_session_t * s)
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   u32 my_thread_id = vlib_get_thread_index ();
   int actual_transfer;
   svm_fifo_t *rx_fifo;

   rx_fifo = s->server_rx_fifo;

   do
     {
       actual_transfer =
 	svm_fifo_dequeue_nowait (rx_fifo, bsm->rcv_buffer_size,
 				 bsm->rx_buf[my_thread_id]);
     }
   while (actual_transfer > 0);
   return 0;
 }

 int
 builtin_server_rx_callback (stream_session_t * s)
 {
   u32 n_written, max_dequeue, max_enqueue, max_transfer;
   int actual_transfer;
   svm_fifo_t *tx_fifo, *rx_fifo;
   builtin_server_main_t *bsm = &builtin_server_main;
   session_fifo_event_t evt;
   u32 thread_index = vlib_get_thread_index ();

   ASSERT (s->thread_index == thread_index);

   rx_fifo = s->server_rx_fifo;
   tx_fifo = s->server_tx_fifo;

   ASSERT (rx_fifo->master_thread_index == thread_index);
   ASSERT (tx_fifo->master_thread_index == thread_index);

   max_dequeue = svm_fifo_max_dequeue (s->server_rx_fifo);
   max_enqueue = svm_fifo_max_enqueue (s->server_tx_fifo);

   if (PREDICT_FALSE (max_dequeue == 0))
     return 0;

   /* Number of bytes we're going to copy */
   max_transfer = (max_dequeue < max_enqueue) ? max_dequeue : max_enqueue;

   /* No space in tx fifo */
   if (PREDICT_FALSE (max_transfer == 0))
     {
       /* XXX timeout for session that are stuck */

     rx_event:
       /* Program self-tap to retry */
       if (svm_fifo_set_event (rx_fifo))
 	{
 	  unix_shared_memory_queue_t *q;
 	  evt.fifo = rx_fifo;
 	  evt.event_type = FIFO_EVENT_BUILTIN_RX;

 	  q = bsm->vpp_queue[thread_index];
 	  if (PREDICT_FALSE (q->cursize == q->maxsize))
 	    clib_warning ("out of event queue space");
 	  else if (unix_shared_memory_queue_add (q, (u8 *) & evt, 0))
 	    clib_warning ("failed to enqueue self-tap");

 	  if (bsm->rx_retries[thread_index][s->session_index] == 500000)
 	    {
 	      clib_warning ("session stuck: %U", format_stream_session, s, 2);
 	    }
 	  if (bsm->rx_retries[thread_index][s->session_index] < 500001)
 	    bsm->rx_retries[thread_index][s->session_index]++;
 	}

       return 0;
     }

   _vec_len (bsm->rx_buf[thread_index]) = max_transfer;

   actual_transfer = svm_fifo_dequeue_nowait (rx_fifo, max_transfer,
 					     bsm->rx_buf[thread_index]);
   ASSERT (actual_transfer == max_transfer);

 //  test_bytes (bsm, actual_transfer);

   /*
    * Echo back
    */

   n_written = svm_fifo_enqueue_nowait (tx_fifo, actual_transfer,
 				       bsm->rx_buf[thread_index]);

   if (n_written != max_transfer)
     clib_warning ("short trout!");

   if (svm_fifo_set_event (tx_fifo))
     {
       /* Fabricate TX event, send to vpp */
       evt.fifo = tx_fifo;
       evt.event_type = FIFO_EVENT_APP_TX;

       if (unix_shared_memory_queue_add (bsm->vpp_queue[s->thread_index],
 					(u8 *) & evt,
 					0 /* do wait for mutex */ ))
 	clib_warning ("failed to enqueue tx evt");
     }

   if (PREDICT_FALSE (n_written < max_dequeue))
     goto rx_event;

   return 0;
 }

 static session_cb_vft_t builtin_session_cb_vft = {
   .session_accept_callback = builtin_session_accept_callback,
   .session_disconnect_callback = builtin_session_disconnect_callback,
   .session_connected_callback = builtin_session_connected_callback,
   .add_segment_callback = builtin_add_segment_callback,
   .redirect_connect_callback = builtin_redirect_connect_callback,
   .builtin_server_rx_callback = builtin_server_rx_callback,
   .session_reset_callback = builtin_session_reset_callback
 };

 /* Abuse VPP's input queue */
 static int
 create_api_loopback (vlib_main_t * vm)
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   api_main_t *am = &api_main;
   vl_shmem_hdr_t *shmem_hdr;

   shmem_hdr = am->shmem_hdr;
   bsm->vl_input_queue = shmem_hdr->vl_input_queue;
   bsm->my_client_index =
     vl_api_memclnt_create_internal ("tcp_test_server", bsm->vl_input_queue);
   return 0;
 }

 static int
 server_attach (u8 * appns_id, u64 appns_flags, u64 appns_secret)
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   u8 segment_name[128];
   u64 options[SESSION_OPTIONS_N_OPTIONS];
   vnet_app_attach_args_t _a, *a = &_a;

   memset (a, 0, sizeof (*a));
   memset (options, 0, sizeof (options));

   if (bsm->no_echo)
     builtin_session_cb_vft.builtin_server_rx_callback =
       builtin_server_rx_callback_no_echo;
   else
     builtin_session_cb_vft.builtin_server_rx_callback =
       builtin_server_rx_callback;
   a->api_client_index = bsm->my_client_index;
   a->session_cb_vft = &builtin_session_cb_vft;
   a->options = options;
   a->options[SESSION_OPTIONS_SEGMENT_SIZE] = 512 << 20;
   a->options[SESSION_OPTIONS_RX_FIFO_SIZE] = bsm->fifo_size;
   a->options[SESSION_OPTIONS_TX_FIFO_SIZE] = bsm->fifo_size;
   a->options[APP_OPTIONS_PRIVATE_SEGMENT_COUNT] = bsm->private_segment_count;
   a->options[APP_OPTIONS_PRIVATE_SEGMENT_SIZE] = bsm->private_segment_size;
   a->options[APP_OPTIONS_PREALLOC_FIFO_PAIRS] =
     bsm->prealloc_fifos ? bsm->prealloc_fifos : 1;

   a->options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
   if (appns_id)
     {
       a->namespace_id = appns_id;
       a->options[APP_OPTIONS_FLAGS] |= appns_flags;
       a->options[APP_OPTIONS_NAMESPACE_SECRET] = appns_secret;
     }
   a->segment_name = segment_name;
   a->segment_name_length = ARRAY_LEN (segment_name);

   if (vnet_application_attach (a))
     {
       clib_warning ("failed to attach server");
       return -1;
     }
   bsm->app_index = a->app_index;
   return 0;
 }

 static int
 server_listen ()
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   vnet_bind_args_t _a, *a = &_a;
   memset (a, 0, sizeof (*a));
   a->app_index = bsm->app_index;
   a->uri = bsm->server_uri;
   return vnet_bind_uri (a);
 }

 static int
 server_create (vlib_main_t * vm, u8 * appns_id, u64 appns_flags,
 	       u64 appns_secret)
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   vlib_thread_main_t *vtm = vlib_get_thread_main ();
   u32 num_threads;
   int i;

   if (bsm->my_client_index == (u32) ~ 0)
     {
       if (create_api_loopback (vm))
 	{
 	  clib_warning ("failed to create api loopback");
 	  return -1;
 	}
     }

   num_threads = 1 /* main thread */  + vtm->n_threads;
   vec_validate (builtin_server_main.vpp_queue, num_threads - 1);
   vec_validate (bsm->rx_buf, num_threads - 1);
   vec_validate (bsm->rx_retries, num_threads - 1);

   for (i = 0; i < num_threads; i++)
     vec_validate (bsm->rx_buf[i], bsm->rcv_buffer_size);

   if (server_attach (appns_id, appns_flags, appns_secret))
     {
       clib_warning ("failed to attach server");
       return -1;
     }
   if (server_listen ())
     {
       clib_warning ("failed to start listening");
       return -1;
     }
   return 0;
 }

 static clib_error_t *
 server_create_command_fn (vlib_main_t * vm, unformat_input_t * input,
 			  vlib_cli_command_t * cmd)
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   u8 server_uri_set = 0, *appns_id = 0;
   u64 tmp, appns_flags = 0, appns_secret = 0;
   int rv;

   bsm->no_echo = 0;
   bsm->fifo_size = 64 << 10;
   bsm->rcv_buffer_size = 128 << 10;
   bsm->prealloc_fifos = 0;
   bsm->private_segment_count = 0;
   bsm->private_segment_size = 0;
   vec_free (bsm->server_uri);

   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat (input, "no-echo"))
 	bsm->no_echo = 1;
       else if (unformat (input, "fifo-size %d", &bsm->fifo_size))
 	bsm->fifo_size <<= 10;
       else if (unformat (input, "rcv-buf-size %d", &bsm->rcv_buffer_size))
 	;
       else if (unformat (input, "prealloc-fifos %d", &bsm->prealloc_fifos))
 	;
       else if (unformat (input, "private-segment-count %d",
 			 &bsm->private_segment_count))
 	;
       else if (unformat (input, "private-segment-size %U",
 			 unformat_memory_size, &tmp))
 	{
 	  if (tmp >= 0x100000000ULL)
 	    return clib_error_return
 	      (0, "private segment size %lld (%llu) too large", tmp, tmp);
 	  bsm->private_segment_size = tmp;
 	}
       else if (unformat (input, "uri %s", &bsm->server_uri))
 	server_uri_set = 1;
       else if (unformat (input, "appns %_%v%_", &appns_id))
 	;
       else if (unformat (input, "all-scope"))
 	appns_flags |= (APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE
 			| APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE);
       else if (unformat (input, "local-scope"))
 	appns_flags |= APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE;
       else if (unformat (input, "global-scope"))
 	appns_flags |= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
       else if (unformat (input, "secret %lu", &appns_secret))
 	;
       else
 	return clib_error_return (0, "unknown input `%U'",
 				  format_unformat_error, input);
     }

   vnet_session_enable_disable (vm, 1 /* turn on TCP, etc. */ );

   if (!server_uri_set)
     bsm->server_uri = (char *) format (0, "tcp://0.0.0.0/1234%c", 0);

   rv = server_create (vm, appns_id, appns_flags, appns_secret);
   vec_free (appns_id);
   switch (rv)
     {
     case 0:
       break;
     default:
       return clib_error_return (0, "server_create returned %d", rv);
     }

   return 0;
 }

 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (server_create_command, static) =
 {
   .path = "test tcp server",
   .short_help = "test tcp server [no echo][fifo-size <mbytes>] "
       "[rcv-buf-size <bytes>][prealloc-fifos <count>]"
       "[private-segment-count <count>][private-segment-size <bytes[m|g]>]"
       "[uri <tcp://ip/port>]",
   .function = server_create_command_fn,
 };
 /* *INDENT-ON* */

 clib_error_t *
 builtin_tcp_server_main_init (vlib_main_t * vm)
 {
   builtin_server_main_t *bsm = &builtin_server_main;
   bsm->my_client_index = ~0;
   return 0;
 }

 VLIB_INIT_FUNCTION (builtin_tcp_server_main_init);

 /*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */
	/*
	* Copyright (c) 2015-2017 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <vnet/vnet.h>
	#include <vlibmemory/api.h>
	#include <vnet/session/application.h>
	#include <vnet/session/application_interface.h>

	typedef struct
	{
	/*
	* Server app parameters
	*/
	unix_shared_memory_queue_t **vpp_queue;
	unix_shared_memory_queue_t vl_input_queue; /< Sever's event queue /

	u32 app_index; /*< Server app index /
	u32 my_client_index; /*< API client handle /
	u32 node_index; /*< process node index for evnt scheduling /

	/*
	* Config params
	*/
	u8 no_echo; /*< Don't echo traffic /
	u32 fifo_size; /*< Fifo size /
	u32 rcv_buffer_size; /*< Rcv buffer size /
	u32 prealloc_fifos; /*< Preallocate fifos /
	u32 private_segment_count; /*< Number of private segments /
	u32 private_segment_size; /*< Size of private segments /
	char server_uri; /< Server URI /

	/*
	* Test state
	*/
	u8 rx_buf; /< Per-thread RX buffer */
	u64 byte_index;
	u32 **rx_retries;

	vlib_main_t *vlib_main;
	} builtin_server_main_t;

	builtin_server_main_t builtin_server_main;

	int
	builtin_session_accept_callback (stream_session_t * s)
	{
	builtin_server_main_t *bsm = &builtin_server_main;

	bsm->vpp_queue[s->thread_index] =
	session_manager_get_vpp_event_queue (s->thread_index);
	s->session_state = SESSION_STATE_READY;
	bsm->byte_index = 0;
	vec_validate (bsm->rx_retries[s->thread_index], s->session_index);
	bsm->rx_retries[s->thread_index][s->session_index] = 0;
	return 0;
	}

	void
	builtin_session_disconnect_callback (stream_session_t * s)
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	vnet_disconnect_args_t _a, *a = &_a;

	a->handle = session_handle (s);
	a->app_index = bsm->app_index;
	vnet_disconnect_session (a);
	}

	void
	builtin_session_reset_callback (stream_session_t * s)
	{
	clib_warning ("Reset session %U", format_stream_session, s, 2);
	stream_session_cleanup (s);
	}


	int
	builtin_session_connected_callback (u32 app_index, u32 api_context,
	stream_session_t * s, u8 is_fail)
	{
	clib_warning ("called...");
	return -1;
	}

	int
	builtin_add_segment_callback (u32 client_index,
	const u8 * seg_name, u32 seg_size)
	{
	clib_warning ("called...");
	return -1;
	}

	int
	builtin_redirect_connect_callback (u32 client_index, void *mp)
	{
	clib_warning ("called...");
	return -1;
	}

	void
	test_bytes (builtin_server_main_t * bsm, int actual_transfer)
	{
	int i;
	u32 my_thread_id = vlib_get_thread_index ();

	for (i = 0; i < actual_transfer; i++)
	{
	if (bsm->rx_buf[my_thread_id][i] != ((bsm->byte_index + i) & 0xff))
	{
	clib_warning ("at %lld expected %d got %d", bsm->byte_index + i,
	(bsm->byte_index + i) & 0xff,
	bsm->rx_buf[my_thread_id][i]);
	}
	}
	bsm->byte_index += actual_transfer;
	}

	/*
	* If no-echo, just read the data and be done with it
	*/
	int
	builtin_server_rx_callback_no_echo (stream_session_t * s)
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	u32 my_thread_id = vlib_get_thread_index ();
	int actual_transfer;
	svm_fifo_t *rx_fifo;

	rx_fifo = s->server_rx_fifo;

	do
	{
	actual_transfer =
	svm_fifo_dequeue_nowait (rx_fifo, bsm->rcv_buffer_size,
	bsm->rx_buf[my_thread_id]);
	}
	while (actual_transfer > 0);
	return 0;
	}

	int
	builtin_server_rx_callback (stream_session_t * s)
	{
	u32 n_written, max_dequeue, max_enqueue, max_transfer;
	int actual_transfer;
	svm_fifo_t tx_fifo, rx_fifo;
	builtin_server_main_t *bsm = &builtin_server_main;
	session_fifo_event_t evt;
	u32 thread_index = vlib_get_thread_index ();

	ASSERT (s->thread_index == thread_index);

	rx_fifo = s->server_rx_fifo;
	tx_fifo = s->server_tx_fifo;

	ASSERT (rx_fifo->master_thread_index == thread_index);
	ASSERT (tx_fifo->master_thread_index == thread_index);

	max_dequeue = svm_fifo_max_dequeue (s->server_rx_fifo);
	max_enqueue = svm_fifo_max_enqueue (s->server_tx_fifo);

	if (PREDICT_FALSE (max_dequeue == 0))
	return 0;

	/* Number of bytes we're going to copy */
	max_transfer = (max_dequeue < max_enqueue) ? max_dequeue : max_enqueue;

	/* No space in tx fifo */
	if (PREDICT_FALSE (max_transfer == 0))
	{
	/* XXX timeout for session that are stuck */

	rx_event:
	/* Program self-tap to retry */
	if (svm_fifo_set_event (rx_fifo))
	{
	unix_shared_memory_queue_t *q;
	evt.fifo = rx_fifo;
	evt.event_type = FIFO_EVENT_BUILTIN_RX;

	q = bsm->vpp_queue[thread_index];
	if (PREDICT_FALSE (q->cursize == q->maxsize))
	clib_warning ("out of event queue space");
	else if (unix_shared_memory_queue_add (q, (u8 *) & evt, 0))
	clib_warning ("failed to enqueue self-tap");

	if (bsm->rx_retries[thread_index][s->session_index] == 500000)
	{
	clib_warning ("session stuck: %U", format_stream_session, s, 2);
	}
	if (bsm->rx_retries[thread_index][s->session_index] < 500001)
	bsm->rx_retries[thread_index][s->session_index]++;
	}

	return 0;
	}

	_vec_len (bsm->rx_buf[thread_index]) = max_transfer;

	actual_transfer = svm_fifo_dequeue_nowait (rx_fifo, max_transfer,
	bsm->rx_buf[thread_index]);
	ASSERT (actual_transfer == max_transfer);

	// test_bytes (bsm, actual_transfer);

	/*
	* Echo back
	*/

	n_written = svm_fifo_enqueue_nowait (tx_fifo, actual_transfer,
	bsm->rx_buf[thread_index]);

	if (n_written != max_transfer)
	clib_warning ("short trout!");

	if (svm_fifo_set_event (tx_fifo))
	{
	/* Fabricate TX event, send to vpp */
	evt.fifo = tx_fifo;
	evt.event_type = FIFO_EVENT_APP_TX;

	if (unix_shared_memory_queue_add (bsm->vpp_queue[s->thread_index],
	(u8 *) & evt,
	0 /* do wait for mutex */ ))
	clib_warning ("failed to enqueue tx evt");
	}

	if (PREDICT_FALSE (n_written < max_dequeue))
	goto rx_event;

	return 0;
	}

	static session_cb_vft_t builtin_session_cb_vft = {
	.session_accept_callback = builtin_session_accept_callback,
	.session_disconnect_callback = builtin_session_disconnect_callback,
	.session_connected_callback = builtin_session_connected_callback,
	.add_segment_callback = builtin_add_segment_callback,
	.redirect_connect_callback = builtin_redirect_connect_callback,
	.builtin_server_rx_callback = builtin_server_rx_callback,
	.session_reset_callback = builtin_session_reset_callback
	};

	/* Abuse VPP's input queue */
	static int
	create_api_loopback (vlib_main_t * vm)
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	api_main_t *am = &api_main;
	vl_shmem_hdr_t *shmem_hdr;

	shmem_hdr = am->shmem_hdr;
	bsm->vl_input_queue = shmem_hdr->vl_input_queue;
	bsm->my_client_index =
	vl_api_memclnt_create_internal ("tcp_test_server", bsm->vl_input_queue);
	return 0;
	}

	static int
	server_attach (u8 * appns_id, u64 appns_flags, u64 appns_secret)
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	u8 segment_name[128];
	u64 options[SESSION_OPTIONS_N_OPTIONS];
	vnet_app_attach_args_t _a, *a = &_a;

	memset (a, 0, sizeof (*a));
	memset (options, 0, sizeof (options));

	if (bsm->no_echo)
	builtin_session_cb_vft.builtin_server_rx_callback =
	builtin_server_rx_callback_no_echo;
	else
	builtin_session_cb_vft.builtin_server_rx_callback =
	builtin_server_rx_callback;
	a->api_client_index = bsm->my_client_index;
	a->session_cb_vft = &builtin_session_cb_vft;
	a->options = options;
	a->options[SESSION_OPTIONS_SEGMENT_SIZE] = 512 << 20;
	a->options[SESSION_OPTIONS_RX_FIFO_SIZE] = bsm->fifo_size;
	a->options[SESSION_OPTIONS_TX_FIFO_SIZE] = bsm->fifo_size;
	a->options[APP_OPTIONS_PRIVATE_SEGMENT_COUNT] = bsm->private_segment_count;
	a->options[APP_OPTIONS_PRIVATE_SEGMENT_SIZE] = bsm->private_segment_size;
	a->options[APP_OPTIONS_PREALLOC_FIFO_PAIRS] =
	bsm->prealloc_fifos ? bsm->prealloc_fifos : 1;

	a->options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
	if (appns_id)
	{
	a->namespace_id = appns_id;
	a->options[APP_OPTIONS_FLAGS] \|= appns_flags;
	a->options[APP_OPTIONS_NAMESPACE_SECRET] = appns_secret;
	}
	a->segment_name = segment_name;
	a->segment_name_length = ARRAY_LEN (segment_name);

	if (vnet_application_attach (a))
	{
	clib_warning ("failed to attach server");
	return -1;
	}
	bsm->app_index = a->app_index;
	return 0;
	}

	static int
	server_listen ()
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	vnet_bind_args_t _a, *a = &_a;
	memset (a, 0, sizeof (*a));
	a->app_index = bsm->app_index;
	a->uri = bsm->server_uri;
	return vnet_bind_uri (a);
	}

	static int
	server_create (vlib_main_t * vm, u8 * appns_id, u64 appns_flags,
	u64 appns_secret)
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	vlib_thread_main_t *vtm = vlib_get_thread_main ();
	u32 num_threads;
	int i;

	if (bsm->my_client_index == (u32) ~ 0)
	{
	if (create_api_loopback (vm))
	{
	clib_warning ("failed to create api loopback");
	return -1;
	}
	}

	num_threads = 1 /* main thread */ + vtm->n_threads;
	vec_validate (builtin_server_main.vpp_queue, num_threads - 1);
	vec_validate (bsm->rx_buf, num_threads - 1);
	vec_validate (bsm->rx_retries, num_threads - 1);

	for (i = 0; i < num_threads; i++)
	vec_validate (bsm->rx_buf[i], bsm->rcv_buffer_size);

	if (server_attach (appns_id, appns_flags, appns_secret))
	{
	clib_warning ("failed to attach server");
	return -1;
	}
	if (server_listen ())
	{
	clib_warning ("failed to start listening");
	return -1;
	}
	return 0;
	}

	static clib_error_t *
	server_create_command_fn (vlib_main_t * vm, unformat_input_t * input,
	vlib_cli_command_t * cmd)
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	u8 server_uri_set = 0, *appns_id = 0;
	u64 tmp, appns_flags = 0, appns_secret = 0;
	int rv;

	bsm->no_echo = 0;
	bsm->fifo_size = 64 << 10;
	bsm->rcv_buffer_size = 128 << 10;
	bsm->prealloc_fifos = 0;
	bsm->private_segment_count = 0;
	bsm->private_segment_size = 0;
	vec_free (bsm->server_uri);

	while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
	{
	if (unformat (input, "no-echo"))
	bsm->no_echo = 1;
	else if (unformat (input, "fifo-size %d", &bsm->fifo_size))
	bsm->fifo_size <<= 10;
	else if (unformat (input, "rcv-buf-size %d", &bsm->rcv_buffer_size))
	;
	else if (unformat (input, "prealloc-fifos %d", &bsm->prealloc_fifos))
	;
	else if (unformat (input, "private-segment-count %d",
	&bsm->private_segment_count))
	;
	else if (unformat (input, "private-segment-size %U",
	unformat_memory_size, &tmp))
	{
	if (tmp >= 0x100000000ULL)
	return clib_error_return
	(0, "private segment size %lld (%llu) too large", tmp, tmp);
	bsm->private_segment_size = tmp;
	}
	else if (unformat (input, "uri %s", &bsm->server_uri))
	server_uri_set = 1;
	else if (unformat (input, "appns %_%v%_", &appns_id))
	;
	else if (unformat (input, "all-scope"))
	appns_flags \|= (APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE
	\| APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE);
	else if (unformat (input, "local-scope"))
	appns_flags \|= APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE;
	else if (unformat (input, "global-scope"))
	appns_flags \|= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
	else if (unformat (input, "secret %lu", &appns_secret))
	;
	else
	return clib_error_return (0, "unknown input `%U'",
	format_unformat_error, input);
	}

	vnet_session_enable_disable (vm, 1 /* turn on TCP, etc. */ );

	if (!server_uri_set)
	bsm->server_uri = (char *) format (0, "tcp://0.0.0.0/1234%c", 0);

	rv = server_create (vm, appns_id, appns_flags, appns_secret);
	vec_free (appns_id);
	switch (rv)
	{
	case 0:
	break;
	default:
	return clib_error_return (0, "server_create returned %d", rv);
	}

	return 0;
	}

	/* INDENT-OFF */
	VLIB_CLI_COMMAND (server_create_command, static) =
	{
	.path = "test tcp server",
	.short_help = "test tcp server [no echo][fifo-size <mbytes>] "
	"[rcv-buf-size <bytes>][prealloc-fifos <count>]"
	"[private-segment-count <count>][private-segment-size <bytes[m\|g]>]"
	"[uri <tcp://ip/port>]",
	.function = server_create_command_fn,
	};
	/* INDENT-ON */

	clib_error_t *
	builtin_tcp_server_main_init (vlib_main_t * vm)
	{
	builtin_server_main_t *bsm = &builtin_server_main;
	bsm->my_client_index = ~0;
	return 0;
	}

	VLIB_INIT_FUNCTION (builtin_tcp_server_main_init);

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