c11 safe string handling support
[vpp.git] / src / vnet / session / session.c
index d258b82..189c537 100644 (file)
 session_manager_main_t session_manager_main;
 extern transport_proto_vft_t *tp_vfts;
 
-static void
-session_send_evt_to_thread (u64 session_handle, fifo_event_type_t evt_type,
-                           u32 thread_index, void *fp, void *rpc_args)
+static inline int
+session_send_evt_to_thread (void *data, void *args, u32 thread_index,
+                           session_evt_type_t evt_type)
 {
-  u32 tries = 0;
-  session_fifo_event_t evt = { {0}, };
-  svm_queue_t *q;
-
-  evt.event_type = evt_type;
-  if (evt_type == FIFO_EVENT_RPC)
-    {
-      evt.rpc_args.fp = fp;
-      evt.rpc_args.arg = rpc_args;
-    }
-  else
-    evt.session_handle = session_handle;
+  session_event_t *evt;
+  svm_msg_q_msg_t msg;
+  svm_msg_q_t *mq;
+  u32 tries = 0, max_tries;
 
-  q = session_manager_get_vpp_event_queue (thread_index);
-  while (svm_queue_add (q, (u8 *) & evt, 1))
+  mq = session_manager_get_vpp_event_queue (thread_index);
+  while (svm_msg_q_try_lock (mq))
     {
-      if (tries++ == 3)
+      max_tries = vlib_get_current_process (vlib_get_main ())? 1e6 : 3;
+      if (tries++ == max_tries)
        {
          SESSION_DBG ("failed to enqueue evt");
-         break;
+         return -1;
        }
     }
+  if (PREDICT_FALSE (svm_msg_q_ring_is_full (mq, SESSION_MQ_IO_EVT_RING)))
+    {
+      svm_msg_q_unlock (mq);
+      return -2;
+    }
+  msg = svm_msg_q_alloc_msg_w_ring (mq, SESSION_MQ_IO_EVT_RING);
+  if (PREDICT_FALSE (svm_msg_q_msg_is_invalid (&msg)))
+    {
+      svm_msg_q_unlock (mq);
+      return -2;
+    }
+  evt = (session_event_t *) svm_msg_q_msg_data (mq, &msg);
+  evt->event_type = evt_type;
+  switch (evt_type)
+    {
+    case FIFO_EVENT_RPC:
+      evt->rpc_args.fp = data;
+      evt->rpc_args.arg = args;
+      break;
+    case FIFO_EVENT_APP_TX:
+    case FIFO_EVENT_BUILTIN_RX:
+      evt->fifo = data;
+      break;
+    case FIFO_EVENT_BUILTIN_TX:
+    case FIFO_EVENT_DISCONNECT:
+      evt->session_handle = session_handle ((stream_session_t *) data);
+      break;
+    default:
+      clib_warning ("evt unhandled!");
+      svm_msg_q_unlock (mq);
+      return -1;
+    }
+
+  svm_msg_q_add_and_unlock (mq, &msg);
+  return 0;
 }
 
-void
-session_send_session_evt_to_thread (u64 session_handle,
-                                   fifo_event_type_t evt_type,
-                                   u32 thread_index)
+int
+session_send_io_evt_to_thread (svm_fifo_t * f, session_evt_type_t evt_type)
 {
-  session_send_evt_to_thread (session_handle, evt_type, thread_index, 0, 0);
+  return session_send_evt_to_thread (f, 0, f->master_thread_index, evt_type);
+}
+
+int
+session_send_io_evt_to_thread_custom (void *data, u32 thread_index,
+                                     session_evt_type_t evt_type)
+{
+  return session_send_evt_to_thread (data, 0, thread_index, evt_type);
+}
+
+int
+session_send_ctrl_evt_to_thread (stream_session_t * s,
+                                session_evt_type_t evt_type)
+{
+  /* only event supported for now is disconnect */
+  ASSERT (evt_type == FIFO_EVENT_DISCONNECT);
+  return session_send_evt_to_thread (s, 0, s->thread_index,
+                                    FIFO_EVENT_DISCONNECT);
 }
 
 void
 session_send_rpc_evt_to_thread (u32 thread_index, void *fp, void *rpc_args)
 {
   if (thread_index != vlib_get_thread_index ())
-    session_send_evt_to_thread (0, FIFO_EVENT_RPC, thread_index, fp,
-                               rpc_args);
+    session_send_evt_to_thread (fp, rpc_args, thread_index, FIFO_EVENT_RPC);
   else
     {
       void (*fnp) (void *) = fp;
@@ -97,7 +139,7 @@ session_alloc (u32 thread_index)
       pool_get_aligned (session_manager_main.sessions[thread_index], s,
                        CLIB_CACHE_LINE_BYTES);
     }
-  memset (s, 0, sizeof (*s));
+  clib_memset (s, 0, sizeof (*s));
   s->session_index = s - session_manager_main.sessions[thread_index];
   s->thread_index = thread_index;
   return s;
@@ -108,7 +150,15 @@ session_free (stream_session_t * s)
 {
   pool_put (session_manager_main.sessions[s->thread_index], s);
   if (CLIB_DEBUG)
-    memset (s, 0xFA, sizeof (*s));
+    clib_memset (s, 0xFA, sizeof (*s));
+}
+
+void
+session_free_w_fifos (stream_session_t * s)
+{
+  segment_manager_dealloc_fifos (s->svm_segment_index, s->server_rx_fifo,
+                                s->server_tx_fifo);
+  session_free (s);
 }
 
 int
@@ -141,12 +191,13 @@ session_alloc_for_connection (transport_connection_t * tc)
   stream_session_t *s;
   u32 thread_index = tc->thread_index;
 
-  ASSERT (thread_index == vlib_get_thread_index ());
+  ASSERT (thread_index == vlib_get_thread_index ()
+         || transport_protocol_is_cl (tc->proto));
 
   s = session_alloc (thread_index);
   s->session_type = session_type_from_proto_and_ip (tc->proto, tc->is_ip4);
   s->session_state = SESSION_STATE_CONNECTING;
-  s->enqueue_epoch = ~0;
+  s->enqueue_epoch = (u64) ~ 0;
 
   /* Attach transport to session and vice versa */
   s->connection_index = tc->c_index;
@@ -342,27 +393,32 @@ session_enqueue_stream_connection (transport_connection_t * tc,
        * by calling stream_server_flush_enqueue_events () */
       session_manager_main_t *smm = vnet_get_session_manager_main ();
       u32 thread_index = s->thread_index;
-      u32 enqueue_epoch = smm->current_enqueue_epoch[tc->proto][thread_index];
+      u64 enqueue_epoch = smm->current_enqueue_epoch[tc->proto][thread_index];
 
       if (s->enqueue_epoch != enqueue_epoch)
        {
          s->enqueue_epoch = enqueue_epoch;
          vec_add1 (smm->session_to_enqueue[tc->proto][thread_index],
-                   s - smm->sessions[thread_index]);
+                   s->session_index);
        }
     }
 
   return enqueued;
 }
 
+
 int
-session_enqueue_dgram_connection (stream_session_t * s, vlib_buffer_t * b,
-                                 u8 proto, u8 queue_event)
+session_enqueue_dgram_connection (stream_session_t * s,
+                                 session_dgram_hdr_t * hdr,
+                                 vlib_buffer_t * b, u8 proto, u8 queue_event)
 {
   int enqueued = 0, rv, in_order_off;
 
-  if (svm_fifo_max_enqueue (s->server_rx_fifo) < b->current_length)
-    return -1;
+  ASSERT (svm_fifo_max_enqueue (s->server_rx_fifo)
+         >= b->current_length + sizeof (*hdr));
+
+  svm_fifo_enqueue_nowait (s->server_rx_fifo, sizeof (session_dgram_hdr_t),
+                          (u8 *) hdr);
   enqueued = svm_fifo_enqueue_nowait (s->server_rx_fifo, b->current_length,
                                      vlib_buffer_get_current (b));
   if (PREDICT_FALSE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) && enqueued >= 0))
@@ -378,13 +434,13 @@ session_enqueue_dgram_connection (stream_session_t * s, vlib_buffer_t * b,
        * by calling stream_server_flush_enqueue_events () */
       session_manager_main_t *smm = vnet_get_session_manager_main ();
       u32 thread_index = s->thread_index;
-      u32 enqueue_epoch = smm->current_enqueue_epoch[proto][thread_index];
+      u64 enqueue_epoch = smm->current_enqueue_epoch[proto][thread_index];
 
       if (s->enqueue_epoch != enqueue_epoch)
        {
          s->enqueue_epoch = enqueue_epoch;
          vec_add1 (smm->session_to_enqueue[proto][thread_index],
-                   s - smm->sessions[thread_index]);
+                   s->session_index);
        }
     }
   return enqueued;
@@ -407,7 +463,7 @@ stream_session_no_space (transport_connection_t * tc, u32 thread_index,
 }
 
 u32
-stream_session_tx_fifo_max_dequeue (transport_connection_t * tc)
+session_tx_fifo_max_dequeue (transport_connection_t * tc)
 {
   stream_session_t *s = session_get (tc->s_index, tc->thread_index);
   if (!s->server_tx_fifo)
@@ -433,69 +489,43 @@ stream_session_dequeue_drop (transport_connection_t * tc, u32 max_bytes)
 /**
  * Notify session peer that new data has been enqueued.
  *
- * @param s Stream session for which the event is to be generated.
- * @param block Flag to indicate if call should block if event queue is full.
+ * @param s    Stream session for which the event is to be generated.
+ * @param lock         Flag to indicate if call should lock message queue.
  *
- * @return 0 on succes or negative number if failed to send notification.
+ * @return 0 on success or negative number if failed to send notification.
  */
-static int
-session_enqueue_notify (stream_session_t * s, u8 block)
+static inline int
+session_enqueue_notify (stream_session_t * s)
 {
-  application_t *app;
-  session_fifo_event_t evt;
-  svm_queue_t *q;
-
-  if (PREDICT_FALSE (s->session_state == SESSION_STATE_CLOSED))
-    {
-      /* Session is closed so app will never clean up. Flush rx fifo */
-      u32 to_dequeue = svm_fifo_max_dequeue (s->server_rx_fifo);
-      if (to_dequeue)
-       svm_fifo_dequeue_drop (s->server_rx_fifo, to_dequeue);
-      return 0;
-    }
-
-  /* Get session's server */
-  app = application_get_if_valid (s->app_index);
+  app_worker_t *app;
 
-  if (PREDICT_FALSE (app == 0))
+  app = app_worker_get_if_valid (s->app_wrk_index);
+  if (PREDICT_FALSE (!app))
     {
-      clib_warning ("invalid s->app_index = %d", s->app_index);
+      SESSION_DBG ("invalid s->app_index = %d", s->app_wrk_index);
       return 0;
     }
 
-  /* Built-in app? Hand event to the callback... */
-  if (app->cb_fns.builtin_app_rx_callback)
-    return app->cb_fns.builtin_app_rx_callback (s);
-
-  /* If no event, send one */
-  if (svm_fifo_set_event (s->server_rx_fifo))
-    {
-      /* Fabricate event */
-      evt.fifo = s->server_rx_fifo;
-      evt.event_type = FIFO_EVENT_APP_RX;
-
-      /* Add event to server's event queue */
-      q = app->event_queue;
-
-      /* Based on request block (or not) for lack of space */
-      if (block || PREDICT_TRUE (q->cursize < q->maxsize))
-       svm_queue_add (app->event_queue, (u8 *) & evt,
-                      0 /* do wait for mutex */ );
-      else
-       {
-         clib_warning ("fifo full");
-         return -1;
-       }
-    }
-
   /* *INDENT-OFF* */
   SESSION_EVT_DBG(SESSION_EVT_ENQ, s, ({
-      ed->data[0] = evt.event_type;
+      ed->data[0] = FIFO_EVENT_APP_RX;
       ed->data[1] = svm_fifo_max_dequeue (s->server_rx_fifo);
   }));
   /* *INDENT-ON* */
 
-  return 0;
+  return app_worker_lock_and_send_event (app, s, FIFO_EVENT_APP_RX);
+}
+
+int
+session_dequeue_notify (stream_session_t * s)
+{
+  app_worker_t *app;
+
+  app = app_worker_get_if_valid (s->app_wrk_index);
+  if (PREDICT_FALSE (!app))
+    return -1;
+
+  return app_worker_lock_and_send_event (app, s, FIFO_EVENT_APP_TX);
 }
 
 /**
@@ -510,16 +540,21 @@ int
 session_manager_flush_enqueue_events (u8 transport_proto, u32 thread_index)
 {
   session_manager_main_t *smm = &session_manager_main;
-  u32 *indices;
   stream_session_t *s;
   int i, errors = 0;
+  u32 *indices;
 
   indices = smm->session_to_enqueue[transport_proto][thread_index];
 
   for (i = 0; i < vec_len (indices); i++)
     {
       s = session_get_if_valid (indices[i], thread_index);
-      if (s == 0 || session_enqueue_notify (s, 0 /* don't block */ ))
+      if (PREDICT_FALSE (!s))
+       {
+         errors++;
+         continue;
+       }
+      if (PREDICT_FALSE (session_enqueue_notify (s)))
        errors++;
     }
 
@@ -530,6 +565,16 @@ session_manager_flush_enqueue_events (u8 transport_proto, u32 thread_index)
   return errors;
 }
 
+int
+session_manager_flush_all_enqueue_events (u8 transport_proto)
+{
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
+  int i, errors = 0;
+  for (i = 0; i < 1 + vtm->n_threads; i++)
+    errors += session_manager_flush_enqueue_events (transport_proto, i);
+  return errors;
+}
+
 /**
  * Init fifo tail and head pointers
  *
@@ -551,6 +596,7 @@ session_stream_connect_notify (transport_connection_t * tc, u8 is_fail)
   u32 opaque = 0, new_ti, new_si;
   stream_session_t *new_s = 0;
   segment_manager_t *sm;
+  app_worker_t *app_wrk;
   application_t *app;
   u8 alloc_fifos;
   int error = 0;
@@ -570,17 +616,18 @@ session_stream_connect_notify (transport_connection_t * tc, u8 is_fail)
   /* Get the app's index from the handle we stored when opening connection
    * and the opaque (api_context for external apps) from transport session
    * index */
-  app = application_get_if_valid (handle >> 32);
-  if (!app)
+  app_wrk = app_worker_get_if_valid (handle >> 32);
+  if (!app_wrk)
     return -1;
   opaque = tc->s_index;
+  app = application_get (app_wrk->app_index);
 
   /*
    * Allocate new session with fifos (svm segments are allocated if needed)
    */
   if (!is_fail)
     {
-      sm = application_get_connect_segment_manager (app);
+      sm = app_worker_get_connect_segment_manager (app_wrk);
       alloc_fifos = !application_is_builtin_proxy (app);
       if (session_alloc_and_init (sm, tc, alloc_fifos, &new_s))
        {
@@ -589,7 +636,7 @@ session_stream_connect_notify (transport_connection_t * tc, u8 is_fail)
        }
       else
        {
-         new_s->app_index = app->index;
+         new_s->app_wrk_index = app_wrk->wrk_index;
          new_si = new_s->session_index;
          new_ti = new_s->thread_index;
        }
@@ -598,8 +645,8 @@ session_stream_connect_notify (transport_connection_t * tc, u8 is_fail)
   /*
    * Notify client application
    */
-  if (app->cb_fns.session_connected_callback (app->index, opaque, new_s,
-                                             is_fail))
+  if (app->cb_fns.session_connected_callback (app_wrk->wrk_index, opaque,
+                                             new_s, is_fail))
     {
       SESSION_DBG ("failed to notify app");
       if (!is_fail)
@@ -686,12 +733,16 @@ session_dgram_connect_notify (transport_connection_t * tc,
 void
 stream_session_accept_notify (transport_connection_t * tc)
 {
-  application_t *server;
+  app_worker_t *app_wrk;
+  application_t *app;
   stream_session_t *s;
 
   s = session_get (tc->s_index, tc->thread_index);
-  server = application_get (s->app_index);
-  server->cb_fns.session_accept_callback (s);
+  app_wrk = app_worker_get_if_valid (s->app_wrk_index);
+  if (!app_wrk)
+    return;
+  app = application_get (app_wrk->app_index);
+  app->cb_fns.session_accept_callback (s);
 }
 
 /**
@@ -704,16 +755,25 @@ stream_session_accept_notify (transport_connection_t * tc)
 void
 stream_session_disconnect_notify (transport_connection_t * tc)
 {
-  application_t *server;
+  app_worker_t *app_wrk;
+  application_t *app;
   stream_session_t *s;
 
   s = session_get (tc->s_index, tc->thread_index);
-  server = application_get (s->app_index);
-  server->cb_fns.session_disconnect_callback (s);
+  if (s->session_state >= SESSION_STATE_TRANSPORT_CLOSING)
+    return;
+  s->session_state = SESSION_STATE_TRANSPORT_CLOSING;
+  app_wrk = app_worker_get_if_valid (s->app_wrk_index);
+  if (!app_wrk)
+    return;
+  app = application_get (app_wrk->app_index);
+  app->cb_fns.session_disconnect_callback (s);
 }
 
 /**
  * Cleans up session and lookup table.
+ *
+ * Transport connection must still be valid.
  */
 void
 stream_session_delete (stream_session_t * s)
@@ -724,10 +784,7 @@ stream_session_delete (stream_session_t * s)
   if ((rv = session_lookup_del_session (s)))
     clib_warning ("hash delete error, rv %d", rv);
 
-  /* Cleanup fifo segments */
-  segment_manager_dealloc_fifos (s->svm_segment_index, s->server_rx_fifo,
-                                s->server_tx_fifo);
-  session_free (s);
+  session_free_w_fifos (s);
 }
 
 /**
@@ -744,10 +801,35 @@ stream_session_delete_notify (transport_connection_t * tc)
   stream_session_t *s;
 
   /* App might've been removed already */
-  s = session_get_if_valid (tc->s_index, tc->thread_index);
-  if (!s)
+  if (!(s = session_get_if_valid (tc->s_index, tc->thread_index)))
     return;
-  stream_session_delete (s);
+
+  /* Make sure we don't try to send anything more */
+  svm_fifo_dequeue_drop_all (s->server_tx_fifo);
+
+  switch (s->session_state)
+    {
+    case SESSION_STATE_TRANSPORT_CLOSING:
+      /* If transport finishes or times out before we get a reply
+       * from the app, do the whole disconnect since we might still
+       * have lingering events */
+      stream_session_disconnect (s);
+      s->session_state = SESSION_STATE_CLOSED;
+      break;
+    case SESSION_STATE_CLOSING:
+      /* Cleanup lookup table. Transport needs to still be valid */
+      session_lookup_del_session (s);
+      s->session_state = SESSION_STATE_CLOSED;
+      break;
+    case SESSION_STATE_CLOSED:
+    case SESSION_STATE_ACCEPTING:
+      stream_session_delete (s);
+      break;
+    default:
+      /* Assume connection was not yet added the lookup table */
+      session_free_w_fifos (s);
+      break;
+    }
 }
 
 /**
@@ -757,10 +839,12 @@ void
 stream_session_reset_notify (transport_connection_t * tc)
 {
   stream_session_t *s;
+  app_worker_t *app_wrk;
   application_t *app;
   s = session_get (tc->s_index, tc->thread_index);
-
-  app = application_get (s->app_index);
+  s->session_state = SESSION_STATE_CLOSED;
+  app_wrk = app_worker_get (s->app_wrk_index);
+  app = application_get (app_wrk->app_index);
   app->cb_fns.session_reset_callback (s);
 }
 
@@ -771,38 +855,40 @@ int
 stream_session_accept (transport_connection_t * tc, u32 listener_index,
                       u8 notify)
 {
-  application_t *server;
   stream_session_t *s, *listener;
+  app_worker_t *app_wrk;
   segment_manager_t *sm;
   int rv;
 
   /* Find the server */
   listener = listen_session_get (listener_index);
-  server = application_get (listener->app_index);
+  app_wrk = application_listener_select_worker (listener, 0);
 
-  sm = application_get_listen_segment_manager (server, listener);
+  sm = app_worker_get_listen_segment_manager (app_wrk, listener);
   if ((rv = session_alloc_and_init (sm, tc, 1, &s)))
     return rv;
 
-  s->app_index = server->index;
+  s->app_wrk_index = app_wrk->wrk_index;
   s->listener_index = listener_index;
   s->session_state = SESSION_STATE_ACCEPTING;
 
   /* Shoulder-tap the server */
   if (notify)
     {
-      server->cb_fns.session_accept_callback (s);
+      application_t *app = application_get (app_wrk->app_index);
+      app->cb_fns.session_accept_callback (s);
     }
 
   return 0;
 }
 
 int
-session_open_cl (u32 app_index, session_endpoint_t * rmt, u32 opaque)
+session_open_cl (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 {
   transport_connection_t *tc;
   transport_endpoint_t *tep;
   segment_manager_t *sm;
+  app_worker_t *app_wrk;
   stream_session_t *s;
   application_t *app;
   int rv;
@@ -819,32 +905,29 @@ session_open_cl (u32 app_index, session_endpoint_t * rmt, u32 opaque)
 
   /* For dgram type of service, allocate session and fifos now.
    */
-  app = application_get (app_index);
-  sm = application_get_connect_segment_manager (app);
+  app_wrk = app_worker_get (app_wrk_index);
+  sm = app_worker_get_connect_segment_manager (app_wrk);
 
   if (session_alloc_and_init (sm, tc, 1, &s))
     return -1;
-  s->app_index = app->index;
-  s->session_state = SESSION_STATE_CONNECTING_READY;
+  s->app_wrk_index = app_wrk->wrk_index;
+  s->session_state = SESSION_STATE_OPENED;
 
   /* Tell the app about the new event fifo for this session */
-  app->cb_fns.session_connected_callback (app->index, opaque, s, 0);
+  app = application_get (app_wrk->app_index);
+  app->cb_fns.session_connected_callback (app_wrk->wrk_index, opaque, s, 0);
 
   return 0;
 }
 
 int
-session_open_vc (u32 app_index, session_endpoint_t * rmt, u32 opaque)
+session_open_vc (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 {
   transport_connection_t *tc;
   transport_endpoint_t *tep;
   u64 handle;
   int rv;
 
-  /* TODO until udp is fixed */
-  if (rmt->transport_proto == TRANSPORT_PROTO_UDP)
-    return session_open_cl (app_index, rmt, opaque);
-
   tep = session_endpoint_to_transport (rmt);
   rv = tp_vfts[rmt->transport_proto].open (tep);
   if (rv < 0)
@@ -862,7 +945,7 @@ session_open_vc (u32 app_index, session_endpoint_t * rmt, u32 opaque)
    * is needed when the connect notify comes and we have to notify the
    * external app
    */
-  handle = (((u64) app_index) << 32) | (u64) tc->c_index;
+  handle = (((u64) app_wrk_index) << 32) | (u64) tc->c_index;
   session_lookup_add_half_open (tc, handle);
 
   /* Store api_context (opaque) for when the reply comes. Not the nicest
@@ -873,10 +956,10 @@ session_open_vc (u32 app_index, session_endpoint_t * rmt, u32 opaque)
 }
 
 int
-session_open_app (u32 app_index, session_endpoint_t * rmt, u32 opaque)
+session_open_app (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 {
   session_endpoint_extended_t *sep = (session_endpoint_extended_t *) rmt;
-  sep->app_index = app_index;
+  sep->app_wrk_index = app_wrk_index;
   sep->opaque = opaque;
 
   return tp_vfts[rmt->transport_proto].open ((transport_endpoint_t *) sep);
@@ -906,84 +989,52 @@ static session_open_service_fn session_open_srv_fns[TRANSPORT_N_SERVICES] = {
  *              on open completion.
  */
 int
-session_open (u32 app_index, session_endpoint_t * rmt, u32 opaque)
+session_open (u32 app_wrk_index, session_endpoint_t * rmt, u32 opaque)
 {
   transport_service_type_t tst = tp_vfts[rmt->transport_proto].service_type;
-  return session_open_srv_fns[tst] (app_index, rmt, opaque);
+  return session_open_srv_fns[tst] (app_wrk_index, rmt, opaque);
 }
 
 /**
- * Ask transport to listen on local transport endpoint.
+ * Ask transport to listen on session endpoint.
  *
  * @param s Session for which listen will be called. Note that unlike
  *         established sessions, listen sessions are not associated to a
  *         thread.
- * @param tep Local endpoint to be listened on.
+ * @param sep Local endpoint to be listened on.
  */
 int
-session_listen_vc (stream_session_t * s, session_endpoint_t * sep)
+session_listen (stream_session_t * ls, session_endpoint_extended_t * sep)
 {
   transport_connection_t *tc;
-  u32 tci;
+  transport_endpoint_t *tep;
+  u32 tc_index, s_index;
 
-  /* Transport bind/listen  */
-  tci = tp_vfts[sep->transport_proto].bind (s->session_index,
-                                           session_endpoint_to_transport
-                                           (sep));
+  /* Transport bind/listen */
+  tep = session_endpoint_to_transport (sep);
+  s_index = ls->session_index;
+  tc_index = tp_vfts[sep->transport_proto].bind (s_index, tep);
 
-  if (tci == (u32) ~ 0)
+  if (tc_index == (u32) ~ 0)
     return -1;
 
   /* Attach transport to session */
-  s->connection_index = tci;
-  tc = tp_vfts[sep->transport_proto].get_listener (tci);
-
-  /* Weird but handle it ... */
-  if (tc == 0)
-    return -1;
+  ls = listen_session_get (s_index);
+  ls->connection_index = tc_index;
 
-  /* Add to the main lookup table */
-  session_lookup_add_connection (tc, s->session_index);
+  /* Add to the main lookup table after transport was initialized */
+  tc = tp_vfts[sep->transport_proto].get_listener (tc_index);
+  session_lookup_add_connection (tc, s_index);
   return 0;
 }
 
-int
-session_listen_app (stream_session_t * s, session_endpoint_t * sep)
-{
-  session_endpoint_extended_t esep;
-  clib_memcpy (&esep, sep, sizeof (*sep));
-  esep.app_index = s->app_index;
-
-  return tp_vfts[sep->transport_proto].bind (s->session_index,
-                                            (transport_endpoint_t *) & esep);
-}
-
-typedef int (*session_listen_service_fn) (stream_session_t *,
-                                         session_endpoint_t *);
-
-/* *INDENT-OFF* */
-static session_listen_service_fn
-session_listen_srv_fns[TRANSPORT_N_SERVICES] = {
-  session_listen_vc,
-  session_listen_vc,
-  session_listen_app,
-};
-/* *INDENT-ON* */
-
-int
-stream_session_listen (stream_session_t * s, session_endpoint_t * sep)
-{
-  transport_service_type_t tst = tp_vfts[sep->transport_proto].service_type;
-  return session_listen_srv_fns[tst] (s, sep);
-}
-
 /**
  * Ask transport to stop listening on local transport endpoint.
  *
  * @param s Session to stop listening on. It must be in state LISTENING.
  */
 int
-stream_session_stop_listen (stream_session_t * s)
+session_stop_listen (stream_session_t * s)
 {
   transport_proto_t tp = session_get_transport_proto (s);
   transport_connection_t *tc;
@@ -1014,11 +1065,34 @@ stream_session_stop_listen (stream_session_t * s)
 void
 stream_session_disconnect (stream_session_t * s)
 {
-  if (!s || s->session_state == SESSION_STATE_CLOSED)
+  u32 thread_index = vlib_get_thread_index ();
+  session_manager_main_t *smm = &session_manager_main;
+  session_event_t *evt;
+
+  if (!s)
     return;
-  s->session_state = SESSION_STATE_CLOSED;
-  session_send_session_evt_to_thread (session_handle (s),
-                                     FIFO_EVENT_DISCONNECT, s->thread_index);
+
+  if (s->session_state >= SESSION_STATE_CLOSING)
+    {
+      /* Session already closed. Clear the tx fifo */
+      if (s->session_state == SESSION_STATE_CLOSED)
+       svm_fifo_dequeue_drop_all (s->server_tx_fifo);
+      return;
+    }
+
+  s->session_state = SESSION_STATE_CLOSING;
+
+  /* If we are in the handler thread, or being called with the worker barrier
+   * held, just append a new event to pending disconnects vector. */
+  if (vlib_thread_is_main_w_barrier () || thread_index == s->thread_index)
+    {
+      vec_add2 (smm->pending_disconnects[s->thread_index], evt, 1);
+      clib_memset (evt, 0, sizeof (*evt));
+      evt->session_handle = session_handle (s);
+      evt->event_type = FIFO_EVENT_DISCONNECT;
+    }
+  else
+    session_send_ctrl_evt_to_thread (s, FIFO_EVENT_DISCONNECT);
 }
 
 /**
@@ -1031,6 +1105,12 @@ stream_session_disconnect (stream_session_t * s)
 void
 stream_session_disconnect_transport (stream_session_t * s)
 {
+  /* If transport is already closed, just free the session */
+  if (s->session_state == SESSION_STATE_CLOSED)
+    {
+      session_free_w_fifos (s);
+      return;
+    }
   s->session_state = SESSION_STATE_CLOSED;
   tp_vfts[session_get_transport_proto (s)].close (s->connection_index,
                                                  s->thread_index);
@@ -1039,23 +1119,44 @@ stream_session_disconnect_transport (stream_session_t * s)
 /**
  * Cleanup transport and session state.
  *
- * Notify transport of the cleanup, wait for a delete notify to actually
- * remove the session state.
+ * Notify transport of the cleanup and free the session. This should
+ * be called only if transport reported some error and is already
+ * closed.
  */
 void
 stream_session_cleanup (stream_session_t * s)
 {
-  int rv;
-
   s->session_state = SESSION_STATE_CLOSED;
 
-  /* Delete from the main lookup table to avoid more enqueues */
-  rv = session_lookup_del_session (s);
-  if (rv)
-    clib_warning ("hash delete error, rv %d", rv);
-
+  /* Delete from main lookup table before we axe the the transport */
+  session_lookup_del_session (s);
   tp_vfts[session_get_transport_proto (s)].cleanup (s->connection_index,
                                                    s->thread_index);
+  /* Since we called cleanup, no delete notification will come. So, make
+   * sure the session is properly freed. */
+  session_free_w_fifos (s);
+}
+
+transport_service_type_t
+session_transport_service_type (stream_session_t * s)
+{
+  transport_proto_t tp;
+  tp = session_get_transport_proto (s);
+  return transport_protocol_service_type (tp);
+}
+
+transport_tx_fn_type_t
+session_transport_tx_fn_type (stream_session_t * s)
+{
+  transport_proto_t tp;
+  tp = session_get_transport_proto (s);
+  return transport_protocol_tx_fn_type (tp);
+}
+
+u8
+session_tx_is_dgram (stream_session_t * s)
+{
+  return (session_transport_tx_fn_type (s) == TRANSPORT_TX_DGRAM);
 }
 
 /**
@@ -1070,7 +1171,7 @@ stream_session_cleanup (stream_session_t * s)
 void
 session_vpp_event_queues_allocate (session_manager_main_t * smm)
 {
-  u32 evt_q_length = 2048, evt_size = sizeof (session_fifo_event_t);
+  u32 evt_q_length = 2048, evt_size = sizeof (session_event_t);
   ssvm_private_t *eqs = &smm->evt_qs_segment;
   api_main_t *am = &api_main;
   u64 eqs_size = 64 << 20;
@@ -1092,7 +1193,11 @@ session_vpp_event_queues_allocate (session_manager_main_t * smm)
       eqs->name = format (0, "%s%c", "evt-qs-segment", 0);
       eqs->requested_va = smm->session_baseva;
 
-      ssvm_master_init (eqs, SSVM_SEGMENT_MEMFD);
+      if (ssvm_master_init (eqs, SSVM_SEGMENT_MEMFD))
+       {
+         clib_warning ("failed to initialize queue segment");
+         return;
+       }
     }
 
   if (smm->evt_qs_use_memfd_seg)
@@ -1102,8 +1207,23 @@ session_vpp_event_queues_allocate (session_manager_main_t * smm)
 
   for (i = 0; i < vec_len (smm->vpp_event_queues); i++)
     {
-      smm->vpp_event_queues[i] = svm_queue_init (evt_q_length, evt_size,
-                                                vpp_pid, 0);
+      svm_msg_q_cfg_t _cfg, *cfg = &_cfg;
+      u32 notif_q_size = clib_max (16, evt_q_length >> 4);
+      svm_msg_q_ring_cfg_t rc[SESSION_MQ_N_RINGS] = {
+       {evt_q_length, evt_size, 0}
+       ,
+       {notif_q_size, 256, 0}
+      };
+      cfg->consumer_pid = 0;
+      cfg->n_rings = 2;
+      cfg->q_nitems = evt_q_length;
+      cfg->ring_cfgs = rc;
+      smm->vpp_event_queues[i] = svm_msg_q_alloc (cfg);
+      if (smm->evt_qs_use_memfd_seg)
+       {
+         if (svm_msg_q_alloc_consumer_eventfd (smm->vpp_event_queues[i]))
+           clib_warning ("eventfd returned");
+       }
     }
 
   if (smm->evt_qs_use_memfd_seg)
@@ -1125,7 +1245,8 @@ session_manager_get_evt_q_segment (void)
 static session_fifo_rx_fn *session_tx_fns[TRANSPORT_TX_N_FNS] = {
     session_tx_fifo_peek_and_snd,
     session_tx_fifo_dequeue_and_snd,
-    session_tx_fifo_dequeue_internal
+    session_tx_fifo_dequeue_internal,
+    session_tx_fifo_dequeue_and_snd
 };
 /* *INDENT-ON* */
 
@@ -1204,6 +1325,14 @@ listen_session_get_local_session_endpoint (stream_session_t * listener,
   return 0;
 }
 
+void
+session_flush_frames_main_thread (vlib_main_t * vm)
+{
+  ASSERT (vlib_get_thread_index () == 0);
+  vlib_process_signal_event_mt (vm, session_queue_process_node.index,
+                               SESSION_Q_PROCESS_FLUSH_FRAMES, 0);
+}
+
 static clib_error_t *
 session_manager_main_enable (vlib_main_t * vm)
 {
@@ -1226,13 +1355,15 @@ session_manager_main_enable (vlib_main_t * vm)
   vec_validate (smm->free_event_vector, num_threads - 1);
   vec_validate (smm->vpp_event_queues, num_threads - 1);
   vec_validate (smm->peekers_rw_locks, num_threads - 1);
+  vec_validate_aligned (smm->ctx, num_threads - 1, CLIB_CACHE_LINE_BYTES);
 
   for (i = 0; i < TRANSPORT_N_PROTO; i++)
-    for (j = 0; j < num_threads; j++)
-      {
-       vec_validate (smm->session_to_enqueue[i], num_threads - 1);
-       vec_validate (smm->current_enqueue_epoch[i], num_threads - 1);
-      }
+    {
+      vec_validate (smm->current_enqueue_epoch[i], num_threads - 1);
+      vec_validate (smm->session_to_enqueue[i], num_threads - 1);
+      for (j = 0; j < num_threads; j++)
+       smm->current_enqueue_epoch[i][j] = 1;
+    }
 
   for (i = 0; i < num_threads; i++)
     {
@@ -1246,7 +1377,7 @@ session_manager_main_enable (vlib_main_t * vm)
        clib_rwlock_init (&smm->peekers_rw_locks[i]);
     }
 
-#if SESSION_DBG
+#if SESSION_DEBUG
   vec_validate (smm->last_event_poll_by_thread, num_threads - 1);
 #endif
 
@@ -1296,8 +1427,30 @@ void
 session_node_enable_disable (u8 is_en)
 {
   u8 state = is_en ? VLIB_NODE_STATE_POLLING : VLIB_NODE_STATE_DISABLED;
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
+  u8 have_workers = vtm->n_threads != 0;
+
   /* *INDENT-OFF* */
   foreach_vlib_main (({
+    if (have_workers && ii == 0)
+      {
+       vlib_node_set_state (this_vlib_main, session_queue_process_node.index,
+                            state);
+       if (is_en)
+         {
+           vlib_node_t *n = vlib_get_node (this_vlib_main,
+                                           session_queue_process_node.index);
+           vlib_start_process (this_vlib_main, n->runtime_index);
+         }
+       else
+         {
+           vlib_process_signal_event_mt (this_vlib_main,
+                                         session_queue_process_node.index,
+                                         SESSION_Q_PROCESS_STOP, 0);
+         }
+
+       continue;
+      }
     vlib_node_set_state (this_vlib_main, session_queue_node.index,
                          state);
   }));