src/vcl/vcl_private.c - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2018-2019 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 <vcl/vcl_private.h>

 static pthread_key_t vcl_worker_stop_key;

 vcl_mq_evt_conn_t *
 vcl_mq_evt_conn_alloc (vcl_worker_t * wrk)
 {
   vcl_mq_evt_conn_t *mqc;
   pool_get (wrk->mq_evt_conns, mqc);
   memset (mqc, 0, sizeof (*mqc));
   return mqc;
 }

 u32
 vcl_mq_evt_conn_index (vcl_worker_t * wrk, vcl_mq_evt_conn_t * mqc)
 {
   return (mqc - wrk->mq_evt_conns);
 }

 vcl_mq_evt_conn_t *
 vcl_mq_evt_conn_get (vcl_worker_t * wrk, u32 mq_conn_idx)
 {
   return pool_elt_at_index (wrk->mq_evt_conns, mq_conn_idx);
 }

 int
 vcl_mq_epoll_add_evfd (vcl_worker_t * wrk, svm_msg_q_t * mq)
 {
   struct epoll_event e = { 0 };
   vcl_mq_evt_conn_t *mqc;
   u32 mqc_index;
   int mq_fd;

   mq_fd = svm_msg_q_get_eventfd (mq);

   if (wrk->mqs_epfd < 0 || mq_fd == -1)
     return -1;

   mqc = vcl_mq_evt_conn_alloc (wrk);
   mqc_index = vcl_mq_evt_conn_index (wrk, mqc);
   mqc->mq_fd = mq_fd;
   mqc->mq = mq;

   e.events = EPOLLIN;
   e.data.u32 = mqc_index;
   if (epoll_ctl (wrk->mqs_epfd, EPOLL_CTL_ADD, mq_fd, &e) < 0)
     {
       VDBG (0, "failed to add mq eventfd to mq epoll fd");
       return -1;
     }

   return mqc_index;
 }

 int
 vcl_mq_epoll_del_evfd (vcl_worker_t * wrk, u32 mqc_index)
 {
   vcl_mq_evt_conn_t *mqc;

   if (wrk->mqs_epfd || mqc_index == ~0)
     return -1;

   mqc = vcl_mq_evt_conn_get (wrk, mqc_index);
   if (epoll_ctl (wrk->mqs_epfd, EPOLL_CTL_DEL, mqc->mq_fd, 0) < 0)
     {
       VDBG (0, "failed to del mq eventfd to mq epoll fd");
       return -1;
     }
   return 0;
 }

 static vcl_worker_t *
 vcl_worker_alloc (void)
 {
   vcl_worker_t *wrk;
   pool_get (vcm->workers, wrk);
   memset (wrk, 0, sizeof (*wrk));
   wrk->wrk_index = wrk - vcm->workers;
   wrk->forked_child = ~0;
   return wrk;
 }

 static void
 vcl_worker_free (vcl_worker_t * wrk)
 {
   pool_put (vcm->workers, wrk);
 }

 int
 vcl_api_app_worker_add (void)
 {
   if (vcm->cfg.vpp_app_socket_api)
     return vcl_sapi_app_worker_add ();

   return vcl_bapi_app_worker_add ();
 }

 void
 vcl_api_app_worker_del (vcl_worker_t * wrk)
 {
   if (vcm->cfg.vpp_app_socket_api)
     return vcl_sapi_app_worker_del (wrk);

   vcl_bapi_app_worker_del (wrk);
 }

 void
 vcl_worker_cleanup (vcl_worker_t * wrk, u8 notify_vpp)
 {
   clib_spinlock_lock (&vcm->workers_lock);
   if (notify_vpp)
     vcl_api_app_worker_del (wrk);

   if (wrk->mqs_epfd > 0)
     close (wrk->mqs_epfd);
   hash_free (wrk->session_index_by_vpp_handles);
   vec_free (wrk->mq_events);
   vec_free (wrk->mq_msg_vector);
   vcl_worker_free (wrk);
   clib_spinlock_unlock (&vcm->workers_lock);
 }

 static void
 vcl_worker_cleanup_cb (void *arg)
 {
   vcl_worker_t *wrk = vcl_worker_get_current ();
   u32 wrk_index = wrk->wrk_index;
   vcl_worker_cleanup (wrk, 1 /* notify vpp */ );
   vcl_set_worker_index (~0);
   VDBG (0, "cleaned up worker %u", wrk_index);
 }

 vcl_worker_t *
 vcl_worker_alloc_and_init ()
 {
   vcl_worker_t *wrk;

   /* This was initialized already */
   if (vcl_get_worker_index () != ~0)
     return 0;

   /* Use separate heap map entry for worker */
   clib_mem_set_thread_index ();

   if (pool_elts (vcm->workers) == vcm->cfg.max_workers)
     {
       VDBG (0, "max-workers %u limit reached", vcm->cfg.max_workers);
       return 0;
     }

   clib_spinlock_lock (&vcm->workers_lock);
   wrk = vcl_worker_alloc ();
   vcl_set_worker_index (wrk->wrk_index);
   wrk->thread_id = pthread_self ();
   wrk->current_pid = getpid ();

   wrk->mqs_epfd = -1;
   if (vcm->cfg.use_mq_eventfd)
     {
       wrk->vcl_needs_real_epoll = 1;
       wrk->mqs_epfd = epoll_create (1);
       wrk->vcl_needs_real_epoll = 0;
       if (wrk->mqs_epfd < 0)
 	{
 	  clib_unix_warning ("epoll_create() returned");
 	  goto done;
 	}
     }

   wrk->session_index_by_vpp_handles = hash_create (0, sizeof (uword));
   clib_time_init (&wrk->clib_time);
   vec_validate (wrk->mq_events, 64);
   vec_validate (wrk->mq_msg_vector, 128);
   vec_reset_length (wrk->mq_msg_vector);
   vec_validate (wrk->unhandled_evts_vector, 128);
   vec_reset_length (wrk->unhandled_evts_vector);
   clib_spinlock_unlock (&vcm->workers_lock);

 done:
   return wrk;
 }

 int
 vcl_worker_register_with_vpp (void)
 {
   vcl_worker_t *wrk = vcl_worker_get_current ();

   clib_spinlock_lock (&vcm->workers_lock);

   if (vcl_api_app_worker_add ())
     {
       VDBG (0, "failed to add worker to vpp");
       clib_spinlock_unlock (&vcm->workers_lock);
       return -1;
     }
   if (pthread_key_create (&vcl_worker_stop_key, vcl_worker_cleanup_cb))
     VDBG (0, "failed to add pthread cleanup function");
   if (pthread_setspecific (vcl_worker_stop_key, &wrk->thread_id))
     VDBG (0, "failed to setup key value");

   clib_spinlock_unlock (&vcm->workers_lock);

   VDBG (0, "added worker %u", wrk->wrk_index);
   return 0;
 }

 svm_msg_q_t *
 vcl_worker_ctrl_mq (vcl_worker_t * wrk)
 {
   return wrk->ctrl_mq;
 }

 int
 vcl_session_read_ready (vcl_session_t * s)
 {
   if (PREDICT_FALSE (s->flags & VCL_SESSION_F_IS_VEP))
     {
       VDBG (0, "ERROR: session %u: cannot read from an epoll session!",
 	    s->session_index);
       return VPPCOM_EBADFD;
     }

   if (vcl_session_is_open (s))
     {
       if (vcl_session_is_ct (s))
 	return svm_fifo_max_dequeue_cons (s->ct_rx_fifo);

       if (s->is_dgram)
 	{
 	  session_dgram_pre_hdr_t ph;
 	  u32 max_deq;

 	  max_deq = svm_fifo_max_dequeue_cons (s->rx_fifo);
 	  if (max_deq <= SESSION_CONN_HDR_LEN)
 	    return 0;
 	  if (svm_fifo_peek (s->rx_fifo, 0, sizeof (ph), (u8 *) & ph) < 0)
 	    return 0;
 	  if (ph.data_length + SESSION_CONN_HDR_LEN > max_deq)
 	    return 0;

 	  return ph.data_length;
 	}

       return svm_fifo_max_dequeue_cons (s->rx_fifo);
     }
   else if (s->session_state == VCL_STATE_LISTEN)
     {
       return clib_fifo_elts (s->accept_evts_fifo);
     }
   else
     {
       return (s->session_state == VCL_STATE_DISCONNECT) ?
 	VPPCOM_ECONNRESET : VPPCOM_ENOTCONN;
     }
 }

 int
 vcl_session_write_ready (vcl_session_t * s)
 {
   if (PREDICT_FALSE (s->flags & VCL_SESSION_F_IS_VEP))
     {
       VDBG (0, "session %u [0x%llx]: cannot write to an epoll session!",
 	    s->session_index, s->vpp_handle);
       return VPPCOM_EBADFD;
     }

   if (vcl_session_is_open (s))
     {
       if (vcl_session_is_ct (s))
 	return svm_fifo_max_enqueue_prod (s->ct_tx_fifo);

       if (s->is_dgram)
 	{
 	  u32 max_enq = svm_fifo_max_enqueue_prod (s->tx_fifo);

 	  if (max_enq <= sizeof (session_dgram_hdr_t))
 	    return 0;
 	  return max_enq - sizeof (session_dgram_hdr_t);
 	}

       return svm_fifo_max_enqueue_prod (s->tx_fifo);
     }
   else if (s->session_state == VCL_STATE_LISTEN)
     {
       if (s->tx_fifo)
 	return svm_fifo_max_enqueue_prod (s->tx_fifo);
       else
 	return VPPCOM_EBADFD;
     }
   else
     {
       return (s->session_state == VCL_STATE_DISCONNECT) ?
 	VPPCOM_ECONNRESET : VPPCOM_ENOTCONN;
     }
 }

 int
 vcl_segment_attach (u64 segment_handle, char *name, ssvm_segment_type_t type,
 		    int fd)
 {
   fifo_segment_create_args_t _a, *a = &_a;
   int rv;

   memset (a, 0, sizeof (*a));
   a->segment_name = name;
   a->segment_type = type;

   if (type == SSVM_SEGMENT_MEMFD)
     a->memfd_fd = fd;

   clib_rwlock_writer_lock (&vcm->segment_table_lock);

   if ((rv = fifo_segment_attach (&vcm->segment_main, a)))
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed", name);
       return rv;
     }
   hash_set (vcm->segment_table, segment_handle, a->new_segment_indices[0]);

   clib_rwlock_writer_unlock (&vcm->segment_table_lock);

   vec_reset_length (a->new_segment_indices);
   return 0;
 }

 u32
 vcl_segment_table_lookup (u64 segment_handle)
 {
   uword *seg_indexp;

   clib_rwlock_reader_lock (&vcm->segment_table_lock);
   seg_indexp = hash_get (vcm->segment_table, segment_handle);
   clib_rwlock_reader_unlock (&vcm->segment_table_lock);

   if (!seg_indexp)
     return VCL_INVALID_SEGMENT_INDEX;
   return ((u32) * seg_indexp);
 }

 void
 vcl_segment_detach (u64 segment_handle)
 {
   fifo_segment_main_t *sm = &vcm->segment_main;
   fifo_segment_t *segment;
   u32 segment_index;

   segment_index = vcl_segment_table_lookup (segment_handle);
   if (segment_index == (u32) ~ 0)
     return;

   clib_rwlock_writer_lock (&vcm->segment_table_lock);

   segment = fifo_segment_get_segment (sm, segment_index);
   fifo_segment_delete (sm, segment);
   hash_unset (vcm->segment_table, segment_handle);

   clib_rwlock_writer_unlock (&vcm->segment_table_lock);

   VDBG (0, "detached segment %u handle %u", segment_index, segment_handle);
 }

 int
 vcl_segment_attach_session (uword segment_handle, uword rxf_offset,
 			    uword txf_offset, uword mq_offset, u8 is_ct,
 			    vcl_session_t *s)
 {
   u32 fs_index, eqs_index;
   svm_fifo_t *rxf, *txf;
   fifo_segment_t *fs;
   u64 eqs_handle;

   fs_index = vcl_segment_table_lookup (segment_handle);
   if (fs_index == VCL_INVALID_SEGMENT_INDEX)
     {
       VDBG (0, "ERROR: segment for session %u is not mounted!",
 	    s->session_index);
       return -1;
     }

   if (!is_ct && mq_offset != (uword) ~0)
     {
       eqs_handle = vcl_vpp_worker_segment_handle (0);
       eqs_index = vcl_segment_table_lookup (eqs_handle);
       ASSERT (eqs_index != VCL_INVALID_SEGMENT_INDEX);
     }

   clib_rwlock_reader_lock (&vcm->segment_table_lock);

   fs = fifo_segment_get_segment (&vcm->segment_main, fs_index);
   rxf = fifo_segment_alloc_fifo_w_offset (fs, rxf_offset);
   txf = fifo_segment_alloc_fifo_w_offset (fs, txf_offset);

   if (!is_ct && mq_offset != (uword) ~0)
     {
       fs = fifo_segment_get_segment (&vcm->segment_main, eqs_index);
       s->vpp_evt_q =
 	fifo_segment_msg_q_attach (fs, mq_offset, rxf->shr->slice_index);
     }

   clib_rwlock_reader_unlock (&vcm->segment_table_lock);

   if (!is_ct)
     {
       rxf->shr->client_session_index = s->session_index;
       txf->shr->client_session_index = s->session_index;
       rxf->client_thread_index = vcl_get_worker_index ();
       txf->client_thread_index = vcl_get_worker_index ();
       s->rx_fifo = rxf;
       s->tx_fifo = txf;
     }
   else
     {
       s->ct_rx_fifo = rxf;
       s->ct_tx_fifo = txf;
     }

   return 0;
 }

 int
 vcl_segment_attach_mq (uword segment_handle, uword mq_offset, u32 mq_index,
 		       svm_msg_q_t **mq)
 {
   fifo_segment_t *fs;
   u32 fs_index;

   fs_index = vcl_segment_table_lookup (segment_handle);
   if (fs_index == VCL_INVALID_SEGMENT_INDEX)
     {
       VDBG (0, "ERROR: mq segment %lx for is not attached!", segment_handle);
       return -1;
     }

   clib_rwlock_reader_lock (&vcm->segment_table_lock);

   fs = fifo_segment_get_segment (&vcm->segment_main, fs_index);
   *mq = fifo_segment_msg_q_attach (fs, mq_offset, mq_index);

   clib_rwlock_reader_unlock (&vcm->segment_table_lock);

   return 0;
 }

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* Copyright (c) 2018-2019 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 <vcl/vcl_private.h>

	static pthread_key_t vcl_worker_stop_key;

	vcl_mq_evt_conn_t *
	vcl_mq_evt_conn_alloc (vcl_worker_t * wrk)
	{
	vcl_mq_evt_conn_t *mqc;
	pool_get (wrk->mq_evt_conns, mqc);
	memset (mqc, 0, sizeof (*mqc));
	return mqc;
	}

	u32
	vcl_mq_evt_conn_index (vcl_worker_t * wrk, vcl_mq_evt_conn_t * mqc)
	{
	return (mqc - wrk->mq_evt_conns);
	}

	vcl_mq_evt_conn_t *
	vcl_mq_evt_conn_get (vcl_worker_t * wrk, u32 mq_conn_idx)
	{
	return pool_elt_at_index (wrk->mq_evt_conns, mq_conn_idx);
	}

	int
	vcl_mq_epoll_add_evfd (vcl_worker_t * wrk, svm_msg_q_t * mq)
	{
	struct epoll_event e = { 0 };
	vcl_mq_evt_conn_t *mqc;
	u32 mqc_index;
	int mq_fd;

	mq_fd = svm_msg_q_get_eventfd (mq);

	if (wrk->mqs_epfd < 0 \|\| mq_fd == -1)
	return -1;

	mqc = vcl_mq_evt_conn_alloc (wrk);
	mqc_index = vcl_mq_evt_conn_index (wrk, mqc);
	mqc->mq_fd = mq_fd;
	mqc->mq = mq;

	e.events = EPOLLIN;
	e.data.u32 = mqc_index;
	if (epoll_ctl (wrk->mqs_epfd, EPOLL_CTL_ADD, mq_fd, &e) < 0)
	{
	VDBG (0, "failed to add mq eventfd to mq epoll fd");
	return -1;
	}

	return mqc_index;
	}

	int
	vcl_mq_epoll_del_evfd (vcl_worker_t * wrk, u32 mqc_index)
	{
	vcl_mq_evt_conn_t *mqc;

	if (wrk->mqs_epfd \|\| mqc_index == ~0)
	return -1;

	mqc = vcl_mq_evt_conn_get (wrk, mqc_index);
	if (epoll_ctl (wrk->mqs_epfd, EPOLL_CTL_DEL, mqc->mq_fd, 0) < 0)
	{
	VDBG (0, "failed to del mq eventfd to mq epoll fd");
	return -1;
	}
	return 0;
	}

	static vcl_worker_t *
	vcl_worker_alloc (void)
	{
	vcl_worker_t *wrk;
	pool_get (vcm->workers, wrk);
	memset (wrk, 0, sizeof (*wrk));
	wrk->wrk_index = wrk - vcm->workers;
	wrk->forked_child = ~0;
	return wrk;
	}

	static void
	vcl_worker_free (vcl_worker_t * wrk)
	{
	pool_put (vcm->workers, wrk);
	}

	int
	vcl_api_app_worker_add (void)
	{
	if (vcm->cfg.vpp_app_socket_api)
	return vcl_sapi_app_worker_add ();

	return vcl_bapi_app_worker_add ();
	}

	void
	vcl_api_app_worker_del (vcl_worker_t * wrk)
	{
	if (vcm->cfg.vpp_app_socket_api)
	return vcl_sapi_app_worker_del (wrk);

	vcl_bapi_app_worker_del (wrk);
	}

	void
	vcl_worker_cleanup (vcl_worker_t * wrk, u8 notify_vpp)
	{
	clib_spinlock_lock (&vcm->workers_lock);
	if (notify_vpp)
	vcl_api_app_worker_del (wrk);

	if (wrk->mqs_epfd > 0)
	close (wrk->mqs_epfd);
	hash_free (wrk->session_index_by_vpp_handles);
	vec_free (wrk->mq_events);
	vec_free (wrk->mq_msg_vector);
	vcl_worker_free (wrk);
	clib_spinlock_unlock (&vcm->workers_lock);
	}

	static void
	vcl_worker_cleanup_cb (void *arg)
	{
	vcl_worker_t *wrk = vcl_worker_get_current ();
	u32 wrk_index = wrk->wrk_index;
	vcl_worker_cleanup (wrk, 1 /* notify vpp */ );
	vcl_set_worker_index (~0);
	VDBG (0, "cleaned up worker %u", wrk_index);
	}

	vcl_worker_t *
	vcl_worker_alloc_and_init ()
	{
	vcl_worker_t *wrk;

	/* This was initialized already */
	if (vcl_get_worker_index () != ~0)
	return 0;

	/* Use separate heap map entry for worker */
	clib_mem_set_thread_index ();

	if (pool_elts (vcm->workers) == vcm->cfg.max_workers)
	{
	VDBG (0, "max-workers %u limit reached", vcm->cfg.max_workers);
	return 0;
	}

	clib_spinlock_lock (&vcm->workers_lock);
	wrk = vcl_worker_alloc ();
	vcl_set_worker_index (wrk->wrk_index);
	wrk->thread_id = pthread_self ();
	wrk->current_pid = getpid ();

	wrk->mqs_epfd = -1;
	if (vcm->cfg.use_mq_eventfd)
	{
	wrk->vcl_needs_real_epoll = 1;
	wrk->mqs_epfd = epoll_create (1);
	wrk->vcl_needs_real_epoll = 0;
	if (wrk->mqs_epfd < 0)
	{
	clib_unix_warning ("epoll_create() returned");
	goto done;
	}
	}

	wrk->session_index_by_vpp_handles = hash_create (0, sizeof (uword));
	clib_time_init (&wrk->clib_time);
	vec_validate (wrk->mq_events, 64);
	vec_validate (wrk->mq_msg_vector, 128);
	vec_reset_length (wrk->mq_msg_vector);
	vec_validate (wrk->unhandled_evts_vector, 128);
	vec_reset_length (wrk->unhandled_evts_vector);
	clib_spinlock_unlock (&vcm->workers_lock);

	done:
	return wrk;
	}

	int
	vcl_worker_register_with_vpp (void)
	{
	vcl_worker_t *wrk = vcl_worker_get_current ();

	clib_spinlock_lock (&vcm->workers_lock);

	if (vcl_api_app_worker_add ())
	{
	VDBG (0, "failed to add worker to vpp");
	clib_spinlock_unlock (&vcm->workers_lock);
	return -1;
	}
	if (pthread_key_create (&vcl_worker_stop_key, vcl_worker_cleanup_cb))
	VDBG (0, "failed to add pthread cleanup function");
	if (pthread_setspecific (vcl_worker_stop_key, &wrk->thread_id))
	VDBG (0, "failed to setup key value");

	clib_spinlock_unlock (&vcm->workers_lock);

	VDBG (0, "added worker %u", wrk->wrk_index);
	return 0;
	}

	svm_msg_q_t *
	vcl_worker_ctrl_mq (vcl_worker_t * wrk)
	{
	return wrk->ctrl_mq;
	}

	int
	vcl_session_read_ready (vcl_session_t * s)
	{
	if (PREDICT_FALSE (s->flags & VCL_SESSION_F_IS_VEP))
	{
	VDBG (0, "ERROR: session %u: cannot read from an epoll session!",
	s->session_index);
	return VPPCOM_EBADFD;
	}

	if (vcl_session_is_open (s))
	{
	if (vcl_session_is_ct (s))
	return svm_fifo_max_dequeue_cons (s->ct_rx_fifo);

	if (s->is_dgram)
	{
	session_dgram_pre_hdr_t ph;
	u32 max_deq;

	max_deq = svm_fifo_max_dequeue_cons (s->rx_fifo);
	if (max_deq <= SESSION_CONN_HDR_LEN)
	return 0;
	if (svm_fifo_peek (s->rx_fifo, 0, sizeof (ph), (u8 *) & ph) < 0)
	return 0;
	if (ph.data_length + SESSION_CONN_HDR_LEN > max_deq)
	return 0;

	return ph.data_length;
	}

	return svm_fifo_max_dequeue_cons (s->rx_fifo);
	}
	else if (s->session_state == VCL_STATE_LISTEN)
	{
	return clib_fifo_elts (s->accept_evts_fifo);
	}
	else
	{
	return (s->session_state == VCL_STATE_DISCONNECT) ?
	VPPCOM_ECONNRESET : VPPCOM_ENOTCONN;
	}
	}

	int
	vcl_session_write_ready (vcl_session_t * s)
	{
	if (PREDICT_FALSE (s->flags & VCL_SESSION_F_IS_VEP))
	{
	VDBG (0, "session %u [0x%llx]: cannot write to an epoll session!",
	s->session_index, s->vpp_handle);
	return VPPCOM_EBADFD;
	}

	if (vcl_session_is_open (s))
	{
	if (vcl_session_is_ct (s))
	return svm_fifo_max_enqueue_prod (s->ct_tx_fifo);

	if (s->is_dgram)
	{
	u32 max_enq = svm_fifo_max_enqueue_prod (s->tx_fifo);

	if (max_enq <= sizeof (session_dgram_hdr_t))
	return 0;
	return max_enq - sizeof (session_dgram_hdr_t);
	}

	return svm_fifo_max_enqueue_prod (s->tx_fifo);
	}
	else if (s->session_state == VCL_STATE_LISTEN)
	{
	if (s->tx_fifo)
	return svm_fifo_max_enqueue_prod (s->tx_fifo);
	else
	return VPPCOM_EBADFD;
	}
	else
	{
	return (s->session_state == VCL_STATE_DISCONNECT) ?
	VPPCOM_ECONNRESET : VPPCOM_ENOTCONN;
	}
	}

	int
	vcl_segment_attach (u64 segment_handle, char *name, ssvm_segment_type_t type,
	int fd)
	{
	fifo_segment_create_args_t _a, *a = &_a;
	int rv;

	memset (a, 0, sizeof (*a));
	a->segment_name = name;
	a->segment_type = type;

	if (type == SSVM_SEGMENT_MEMFD)
	a->memfd_fd = fd;

	clib_rwlock_writer_lock (&vcm->segment_table_lock);

	if ((rv = fifo_segment_attach (&vcm->segment_main, a)))
	{
	clib_warning ("svm_fifo_segment_attach ('%s') failed", name);
	return rv;
	}
	hash_set (vcm->segment_table, segment_handle, a->new_segment_indices[0]);

	clib_rwlock_writer_unlock (&vcm->segment_table_lock);

	vec_reset_length (a->new_segment_indices);
	return 0;
	}

	u32
	vcl_segment_table_lookup (u64 segment_handle)
	{
	uword *seg_indexp;

	clib_rwlock_reader_lock (&vcm->segment_table_lock);
	seg_indexp = hash_get (vcm->segment_table, segment_handle);
	clib_rwlock_reader_unlock (&vcm->segment_table_lock);

	if (!seg_indexp)
	return VCL_INVALID_SEGMENT_INDEX;
	return ((u32) * seg_indexp);
	}

	void
	vcl_segment_detach (u64 segment_handle)
	{
	fifo_segment_main_t *sm = &vcm->segment_main;
	fifo_segment_t *segment;
	u32 segment_index;

	segment_index = vcl_segment_table_lookup (segment_handle);
	if (segment_index == (u32) ~ 0)
	return;

	clib_rwlock_writer_lock (&vcm->segment_table_lock);

	segment = fifo_segment_get_segment (sm, segment_index);
	fifo_segment_delete (sm, segment);
	hash_unset (vcm->segment_table, segment_handle);

	clib_rwlock_writer_unlock (&vcm->segment_table_lock);

	VDBG (0, "detached segment %u handle %u", segment_index, segment_handle);
	}

	int
	vcl_segment_attach_session (uword segment_handle, uword rxf_offset,
	uword txf_offset, uword mq_offset, u8 is_ct,
	vcl_session_t *s)
	{
	u32 fs_index, eqs_index;
	svm_fifo_t rxf, txf;
	fifo_segment_t *fs;
	u64 eqs_handle;

	fs_index = vcl_segment_table_lookup (segment_handle);
	if (fs_index == VCL_INVALID_SEGMENT_INDEX)
	{
	VDBG (0, "ERROR: segment for session %u is not mounted!",
	s->session_index);
	return -1;
	}

	if (!is_ct && mq_offset != (uword) ~0)
	{
	eqs_handle = vcl_vpp_worker_segment_handle (0);
	eqs_index = vcl_segment_table_lookup (eqs_handle);
	ASSERT (eqs_index != VCL_INVALID_SEGMENT_INDEX);
	}

	clib_rwlock_reader_lock (&vcm->segment_table_lock);

	fs = fifo_segment_get_segment (&vcm->segment_main, fs_index);
	rxf = fifo_segment_alloc_fifo_w_offset (fs, rxf_offset);
	txf = fifo_segment_alloc_fifo_w_offset (fs, txf_offset);

	if (!is_ct && mq_offset != (uword) ~0)
	{
	fs = fifo_segment_get_segment (&vcm->segment_main, eqs_index);
	s->vpp_evt_q =
	fifo_segment_msg_q_attach (fs, mq_offset, rxf->shr->slice_index);
	}

	clib_rwlock_reader_unlock (&vcm->segment_table_lock);

	if (!is_ct)
	{
	rxf->shr->client_session_index = s->session_index;
	txf->shr->client_session_index = s->session_index;
	rxf->client_thread_index = vcl_get_worker_index ();
	txf->client_thread_index = vcl_get_worker_index ();
	s->rx_fifo = rxf;
	s->tx_fifo = txf;
	}
	else
	{
	s->ct_rx_fifo = rxf;
	s->ct_tx_fifo = txf;
	}

	return 0;
	}

	int
	vcl_segment_attach_mq (uword segment_handle, uword mq_offset, u32 mq_index,
	svm_msg_q_t **mq)
	{
	fifo_segment_t *fs;
	u32 fs_index;

	fs_index = vcl_segment_table_lookup (segment_handle);
	if (fs_index == VCL_INVALID_SEGMENT_INDEX)
	{
	VDBG (0, "ERROR: mq segment %lx for is not attached!", segment_handle);
	return -1;
	}

	clib_rwlock_reader_lock (&vcm->segment_table_lock);

	fs = fifo_segment_get_segment (&vcm->segment_main, fs_index);
	*mq = fifo_segment_msg_q_attach (fs, mq_offset, mq_index);

	clib_rwlock_reader_unlock (&vcm->segment_table_lock);

	return 0;
	}

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