vcl: add apis that expos fifo as buffer

Change-Id: I4bd9c9f73499711e04b38d53daa5c917a4285bf5
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 106 insertions, 22 deletions

diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 6d6e7d08797..df8f4cae964 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -1274,19 +1274,9 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
     return VPPCOM_EINVAL;
 
   s = vcl_session_get_w_handle (wrk, session_handle);
-  if (PREDICT_FALSE (!s))
+  if (PREDICT_FALSE (!s || s->is_vep))
     return VPPCOM_EBADFD;
 
-  if (PREDICT_FALSE (s->is_vep))
-    {
-      clib_warning ("VCL<%d>: ERROR: sid %u: cannot "
-		    "read from an epoll session!", getpid (), session_handle);
-      return VPPCOM_EBADFD;
-    }
-
-  is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);
-  rx_fifo = s->rx_fifo;
-
   if (PREDICT_FALSE (!vcl_session_is_readable (s)))
     {
       session_state_t state = s->session_state;
@@ -1299,8 +1289,10 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
       return rv;
     }
 
+  is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);
   is_ct = vcl_session_is_ct (s);
   mq = is_ct ? s->our_evt_q : wrk->app_event_queue;
+  rx_fifo = s->rx_fifo;
 
   if (svm_fifo_is_empty (rx_fifo))
     {
@@ -1348,17 +1340,9 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
 				SESSION_IO_EVT_CT_RX, SVM_Q_WAIT);
     }
 
-  if (VPPCOM_DEBUG > 2)
-    {
-      if (n_read > 0)
-	clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: read %d bytes "
-		      "from (%p)", getpid (), s->vpp_handle,
-		      session_handle, n_read, rx_fifo);
-      else
-	clib_warning ("VCL<%d>: vpp handle 0x%llx, sid %u: nothing read! "
-		      "returning %d (%s)", getpid (), s->vpp_handle,
-		      session_handle, n_read, vppcom_retval_str (n_read));
-    }
+  VDBG (2, "VCL<%d>: vpp handle 0x%llx, sid %u: read %d bytes from (%p)",
+	getpid (), s->vpp_handle, session_handle, n_read, rx_fifo);
+
   return n_read;
 }
 
@@ -1374,6 +1358,93 @@ vppcom_session_peek (uint32_t session_handle, void *buf, int n)
   return (vppcom_session_read_internal (session_handle, buf, n, 1));
 }
 
+int
+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;
+  vcl_session_t *s = 0;
+  svm_fifo_t *rx_fifo;
+  svm_msg_q_msg_t msg;
+  session_event_t *e;
+  svm_msg_q_t *mq;
+  u8 is_ct;
+
+  s = vcl_session_get_w_handle (wrk, 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;
+    }
+
+  is_nonblocking = VCL_SESS_ATTR_TEST (s->attr, VCL_SESS_ATTR_NONBLOCK);
+  is_ct = vcl_session_is_ct (s);
+  mq = is_ct ? s->our_evt_q : wrk->app_event_queue;
+  rx_fifo = s->rx_fifo;
+
+  if (svm_fifo_is_empty (rx_fifo))
+    {
+      if (is_nonblocking)
+	{
+	  svm_fifo_unset_event (rx_fifo);
+	  return VPPCOM_OK;
+	}
+      while (svm_fifo_is_empty (rx_fifo))
+	{
+	  svm_fifo_unset_event (rx_fifo);
+	  svm_msg_q_lock (mq);
+	  if (svm_msg_q_is_empty (mq))
+	    svm_msg_q_wait (mq);
+
+	  svm_msg_q_sub_w_lock (mq, &msg);
+	  e = svm_msg_q_msg_data (mq, &msg);
+	  svm_msg_q_unlock (mq);
+	  if (!vcl_is_rx_evt_for_session (e, s->session_index, is_ct))
+	    {
+	      vcl_handle_mq_ctrl_event (wrk, e);
+	      svm_msg_q_free_msg (mq, &msg);
+	      continue;
+	    }
+	  svm_msg_q_free_msg (mq, &msg);
+
+	  if (PREDICT_FALSE (s->session_state == STATE_CLOSE_ON_EMPTY))
+	    return 0;
+	}
+    }
+
+  n_read = svm_fifo_segments (rx_fifo, (svm_fifo_segment_t *) ds);
+  svm_fifo_unset_event (rx_fifo);
+
+  if (is_ct && n_read + svm_fifo_max_dequeue (rx_fifo) == rx_fifo->nitems)
+    {
+      /* If the peer is not polling send notification */
+      if (!svm_fifo_has_event (s->rx_fifo))
+	app_send_io_evt_to_vpp (s->vpp_evt_q, s->rx_fifo,
+				SESSION_IO_EVT_CT_RX, SVM_Q_WAIT);
+    }
+
+  return n_read;
+}
+
+void
+vppcom_session_free_segments (uint32_t session_handle,
+			      vppcom_data_segments_t ds)
+{
+  vcl_worker_t *wrk = vcl_worker_get_current ();
+  vcl_session_t *s;
+
+  s = vcl_session_get_w_handle (wrk, session_handle);
+  if (PREDICT_FALSE (!s || s->is_vep))
+    return;
+
+  svm_fifo_segments_free (s->rx_fifo, (svm_fifo_segment_t *) ds);
+}
+
 static inline int
 vppcom_session_read_ready (vcl_session_t * session)
 {
@@ -1405,6 +1476,19 @@ vppcom_session_read_ready (vcl_session_t * session)
   return svm_fifo_max_dequeue (session->rx_fifo);
 }
 
+int
+vppcom_data_segment_copy (void *buf, vppcom_data_segments_t ds, u32 max_bytes)
+{
+  u32 first_copy = clib_min (ds[0].len, max_bytes);
+  clib_memcpy (buf, ds[0].data, first_copy);
+  if (first_copy < max_bytes)
+    {
+      clib_memcpy (buf + first_copy, ds[1].data,
+		   clib_min (ds[1].len, max_bytes - first_copy));
+    }
+  return 0;
+}
+
 static u8
 vcl_is_tx_evt_for_session (session_event_t * e, u32 sid, u8 is_ct)
 {