vcl: improve handling of close on rw

Change-Id: Ie01a37612d7e3e0d0bad0f0aa9583b3ed411f46f
Signed-off-by: Florin Coras <fcoras@cisco.com>

2 files changed, 55 insertions, 48 deletions

diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index c61bb0b9247..39c9e7207c7 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -504,6 +504,34 @@ vcl_session_is_ct (vcl_session_t * s)
   return (s->our_evt_q != 0);
 }
 
+static inline u8
+vcl_session_is_open (vcl_session_t * s)
+{
+  return ((s->session_state & STATE_OPEN)
+	  || (s->session_state == STATE_LISTEN
+	      && s->session_type == VPPCOM_PROTO_UDP));
+}
+
+static inline u8
+vcl_session_is_closing (vcl_session_t * s)
+{
+  return (s->session_state == STATE_VPP_CLOSING
+	  || s->session_state == STATE_DISCONNECT);
+}
+
+static inline int
+vcl_session_closing_error (vcl_session_t * s)
+{
+  return s->session_state == STATE_DISCONNECT ? VPPCOM_ECONNRESET : 0;
+}
+
+static inline int
+vcl_session_closed_error (vcl_session_t * s)
+{
+  return s->session_state == STATE_DISCONNECT
+    ? VPPCOM_ECONNRESET : VPPCOM_ENOTCONN;
+}
+
 /*
  * Helpers
  */
diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 570e323bb49..3c3e15d146c 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -661,7 +661,6 @@ vcl_handle_mq_event (vcl_worker_t * wrk, session_event_t * e)
       session = vcl_session_disconnected_handler (wrk, disconnected_msg);
       if (!session)
 	break;
-      session->session_state = STATE_DISCONNECT;
       VDBG (0, "disconnected session %u [0x%llx]", session->session_index,
 	    session->vpp_handle);
       break;
@@ -1514,20 +1513,12 @@ vcl_is_rx_evt_for_session (session_event_t * e, u32 sid, u8 is_ct)
     return (e->event_type == SESSION_IO_EVT_CT_TX);
 }
 
-static inline u8
-vcl_session_is_readable (vcl_session_t * s)
-{
-  return ((s->session_state & STATE_OPEN)
-	  || (s->session_state == STATE_LISTEN
-	      && s->session_type == VPPCOM_PROTO_UDP));
-}
-
 static inline int
 vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
 			      u8 peek)
 {
   vcl_worker_t *wrk = vcl_worker_get_current ();
-  int n_read = 0, rv, is_nonblocking;
+  int n_read = 0, is_nonblocking;
   vcl_session_t *s = 0;
   svm_fifo_t *rx_fifo;
   svm_msg_q_msg_t msg;
@@ -1542,15 +1533,12 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
   if (PREDICT_FALSE (!s || s->is_vep))
     return VPPCOM_EBADFD;
 
-  if (PREDICT_FALSE (!vcl_session_is_readable (s)))
+  if (PREDICT_FALSE (!vcl_session_is_open (s)))
     {
-      session_state_t state = s->session_state;
-      rv = ((state & STATE_DISCONNECT) ? VPPCOM_ECONNRESET : VPPCOM_ENOTCONN);
-
-      VDBG (0, "session handle %u[0x%llx] is not open! state 0x%x (%s),"
-	    " returning %d (%s)", session_handle, s->vpp_handle, state,
-	    vppcom_session_state_str (state), rv, vppcom_retval_str (rv));
-      return rv;
+      VDBG (0, "session handle %u[0x%llx] is not open! state 0x%x (%s)",
+	    s->session_index, s->vpp_handle, s->session_state,
+	    vppcom_session_state_str (s->session_state));
+      return vcl_session_closed_error (s);
     }
 
   is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);
@@ -1568,6 +1556,9 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
 	}
       while (svm_fifo_is_empty (rx_fifo))
 	{
+	  if (vcl_session_is_closing (s))
+	    return vcl_session_closing_error (s);
+
 	  svm_fifo_unset_event (rx_fifo);
 	  svm_msg_q_lock (mq);
 	  if (svm_msg_q_is_empty (mq))
@@ -1579,9 +1570,6 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
 	  if (!vcl_is_rx_evt_for_session (e, s->session_index, is_ct))
 	    vcl_handle_mq_event (wrk, e);
 	  svm_msg_q_free_msg (mq, &msg);
-
-	  if (PREDICT_FALSE (s->session_state == STATE_DISCONNECT))
-	    return VPPCOM_ECONNRESET;
 	}
     }
 
@@ -1623,7 +1611,7 @@ vppcom_session_read_segments (uint32_t session_handle,
 			      vppcom_data_segments_t ds)
 {
   vcl_worker_t *wrk = vcl_worker_get_current ();
-  int n_read = 0, rv, is_nonblocking;
+  int n_read = 0, is_nonblocking;
   vcl_session_t *s = 0;
   svm_fifo_t *rx_fifo;
   svm_msg_q_msg_t msg;
@@ -1635,12 +1623,8 @@ vppcom_session_read_segments (uint32_t session_handle,
   if (PREDICT_FALSE (!s || s->is_vep))
     return VPPCOM_EBADFD;
 
-  if (PREDICT_FALSE (!vcl_session_is_readable (s)))
-    {
-      session_state_t state = s->session_state;
-      rv = ((state & STATE_DISCONNECT) ? VPPCOM_ECONNRESET : VPPCOM_ENOTCONN);
-      return rv;
-    }
+  if (PREDICT_FALSE (!vcl_session_is_open (s)))
+    return vcl_session_closed_error (s);
 
   is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);
   is_ct = vcl_session_is_ct (s);
@@ -1657,6 +1641,9 @@ vppcom_session_read_segments (uint32_t session_handle,
 	}
       while (svm_fifo_is_empty (rx_fifo))
 	{
+	  if (vcl_session_is_closing (s))
+	    return vcl_session_closing_error (s);
+
 	  svm_fifo_unset_event (rx_fifo);
 	  svm_msg_q_lock (mq);
 	  if (svm_msg_q_is_empty (mq))
@@ -1668,9 +1655,6 @@ vppcom_session_read_segments (uint32_t session_handle,
 	  if (!vcl_is_rx_evt_for_session (e, s->session_index, is_ct))
 	    vcl_handle_mq_event (wrk, e);
 	  svm_msg_q_free_msg (mq, &msg);
-
-	  if (PREDICT_FALSE (s->session_state == STATE_DISCONNECT))
-	    return VPPCOM_ECONNRESET;
 	}
     }
 
@@ -1730,7 +1714,7 @@ vppcom_session_write_inline (uint32_t session_handle, void *buf, size_t n,
 			     u8 is_flush)
 {
   vcl_worker_t *wrk = vcl_worker_get_current ();
-  int rv, n_write, is_nonblocking;
+  int n_write, is_nonblocking;
   vcl_session_t *s = 0;
   svm_fifo_t *tx_fifo = 0;
   session_evt_type_t et;
@@ -1748,21 +1732,17 @@ vppcom_session_write_inline (uint32_t session_handle, void *buf, size_t n,
 
   if (PREDICT_FALSE (s->is_vep))
     {
-      clib_warning ("VCL<%d>: ERROR: vpp handle 0x%llx, sid %u: "
-		    "cannot write to an epoll session!",
-		    getpid (), s->vpp_handle, session_handle);
-
+      VDBG (0, "ERROR: session %u [0x%llx]: cannot write to an epoll"
+	    " session!", s->session_index, s->vpp_handle);
       return VPPCOM_EBADFD;
     }
 
-  if (PREDICT_FALSE (!(s->session_state & STATE_OPEN)))
+  if (PREDICT_FALSE (!vcl_session_is_open (s)))
     {
-      session_state_t state = s->session_state;
-      rv = ((state & STATE_DISCONNECT) ? VPPCOM_ECONNRESET : VPPCOM_ENOTCONN);
-      VDBG (1, "VCL<%d>: vpp handle 0x%llx, sid %u: session is not open! "
-	    "state 0x%x (%s)", getpid (), s->vpp_handle, session_handle,
-	    state, vppcom_session_state_str (state));
-      return rv;
+      VDBG (1, "session %u [0x%llx]: is not open! state 0x%x (%s)",
+	    s->session_index, s->vpp_handle, s->session_state,
+	    vppcom_session_state_str (s->session_state));
+      return vcl_session_closed_error (s);;
     }
 
   tx_fifo = s->tx_fifo;
@@ -1778,6 +1758,8 @@ vppcom_session_write_inline (uint32_t session_handle, void *buf, size_t n,
       while (svm_fifo_is_full (tx_fifo))
 	{
 	  svm_fifo_add_want_tx_ntf (tx_fifo, SVM_FIFO_WANT_TX_NOTIF);
+	  if (vcl_session_is_closing (s))
+	    return vcl_session_closing_error (s);
 	  svm_msg_q_lock (mq);
 	  if (svm_msg_q_is_empty (mq))
 	    svm_msg_q_wait (mq);
@@ -1789,9 +1771,6 @@ vppcom_session_write_inline (uint32_t session_handle, void *buf, size_t n,
 	  if (!vcl_is_tx_evt_for_session (e, s->session_index, is_ct))
 	    vcl_handle_mq_event (wrk, e);
 	  svm_msg_q_free_msg (mq, &msg);
-
-	  if (PREDICT_FALSE (!(s->session_state & STATE_OPEN)))
-	    return VPPCOM_ECONNRESET;
 	}
     }
 
@@ -1809,8 +1788,8 @@ vppcom_session_write_inline (uint32_t session_handle, void *buf, size_t n,
 
   ASSERT (n_write > 0);
 
-  VDBG (2, "VCL<%d>: vpp handle 0x%llx, sid %u: wrote %d bytes", getpid (),
-	s->vpp_handle, session_handle, n_write);
+  VDBG (2, "session %u [0x%llx]: wrote %d bytes", s->session_index,
+	s->vpp_handle, n_write);
 
   return n_write;
 }