/*
 * 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);
  pool_free (wrk->sessions);
  pool_free (wrk->mq_evt_conns);
  hash_free (wrk->session_index_by_vpp_handles);
  vec_free (wrk->mq_events);
  vec_free (wrk->mq_msg_vector);
  vec_free (wrk->unhandled_evts_vector);
  vec_free (wrk->pending_session_wrk_updates);
  clib_bitmap_free (wrk->rd_bitmap);
  clib_bitmap_free (wrk->wr_bitmap);
  clib_bitmap_free (wrk->ex_bitmap);
  vcl_worker_free (wrk);
  clib_spinlock_unlock (&vcm->workers_lock);
}

static void
vcl_worker_cleanup_cb (void *arg)
{
  vcl_worker_t *wrk;
  u32 wrk_index;

  wrk_index = vcl_get_worker_index ();
  wrk = vcl_worker_get_if_valid (wrk_index);
  if (!wrk)
    return;

  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->ep_lt_current = VCL_INVALID_SESSION_INDEX;
  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 if (s->session_state == VCL_STATE_UPDATED)
    {
      return 0;
    }
  else
    {
      return (s->session_state == VCL_STATE_DISCONNECT) ?
	VPPCOM_ECONNRESET : VPPCOM_ENOTCONN;
    }
}

int
vcl_session_alloc_ext_cfg (vcl_session_t *s,
			   transport_endpt_ext_cfg_type_t type, u32 len)
{
  if (s->ext_config)
    return -1;

  s->ext_config = clib_mem_alloc (len);
  clib_memset (s->ext_config, 0, len);
  s->ext_config->len = len;
  s->ext_config->type = type;

  return 0;
}

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_free (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);
  rxf->segment_index = fs_index;
  txf->segment_index = fs_index;

  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;
}

void
vcl_session_detach_fifos (vcl_session_t *s)
{
  fifo_segment_t *fs;

  if (!s->rx_fifo)
    return;

  clib_rwlock_reader_lock (&vcm->segment_table_lock);

  fs = fifo_segment_get_segment_if_valid (&vcm->segment_main,
					  s->rx_fifo->segment_index);
  if (!fs)
    goto done;

  fifo_segment_free_client_fifo (fs, s->rx_fifo);
  fifo_segment_free_client_fifo (fs, s->tx_fifo);
  if (s->ct_rx_fifo)
    {
      fs = fifo_segment_get_segment_if_valid (&vcm->segment_main,
					      s->ct_rx_fifo->segment_index);
      if (!fs)
	goto done;

      fifo_segment_free_client_fifo (fs, s->ct_rx_fifo);
      fifo_segment_free_client_fifo (fs, s->ct_tx_fifo);
    }

done:
  clib_rwlock_reader_unlock (&vcm->segment_table_lock);
}

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;
}

int
vcl_segment_discover_mqs (uword segment_handle, int *fds, u32 n_fds)
{
  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);
  fifo_segment_msg_qs_discover (fs, fds, n_fds);

  clib_rwlock_reader_unlock (&vcm->segment_table_lock);

  return 0;
}

svm_fifo_chunk_t *
vcl_segment_alloc_chunk (uword segment_handle, u32 slice_index, u32 size,
			 uword *offset)
{
  svm_fifo_chunk_t *c;
  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 0;
    }

  clib_rwlock_reader_lock (&vcm->segment_table_lock);

  fs = fifo_segment_get_segment (&vcm->segment_main, fs_index);
  c = fifo_segment_alloc_chunk_w_slice (fs, slice_index, size);
  *offset = fifo_segment_chunk_offset (fs, c);

  clib_rwlock_reader_unlock (&vcm->segment_table_lock);

  return c;
}

int
vcl_session_share_fifos (vcl_session_t *s, svm_fifo_t *rxf, svm_fifo_t *txf)
{
  vcl_worker_t *wrk = vcl_worker_get_current ();
  fifo_segment_t *fs;

  clib_rwlock_reader_lock (&vcm->segment_table_lock);

  fs = fifo_segment_get_segment (&vcm->segment_main, rxf->segment_index);
  s->rx_fifo = fifo_segment_duplicate_fifo (fs, rxf);
  s->tx_fifo = fifo_segment_duplicate_fifo (fs, txf);

  clib_rwlock_reader_unlock (&vcm->segment_table_lock);

  svm_fifo_add_subscriber (s->rx_fifo, wrk->vpp_wrk_index);
  svm_fifo_add_subscriber (s->tx_fifo, wrk->vpp_wrk_index);

  return 0;
}

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