Add support for tcp/session buffer chains

Change-Id: I01c6e3dc3a1b2785df37bb66b19c4b5cbb8f3211
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 78 insertions, 11 deletions

diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index e92bb440601..6e129dde018 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -432,33 +432,97 @@ stream_session_create_i (segment_manager_t * sm, transport_connection_t * tc,
   return 0;
 }
 
+/** Enqueue buffer chain tail */
+always_inline int
+session_enqueue_chain_tail (stream_session_t * s, vlib_buffer_t * b,
+			    u32 offset, u8 is_in_order)
+{
+  vlib_buffer_t *chain_b;
+  u32 chain_bi = b->next_buffer;
+  vlib_main_t *vm = vlib_get_main ();
+  u8 *data, len;
+  u16 written = 0;
+  int rv = 0;
+
+  do
+    {
+      chain_b = vlib_get_buffer (vm, chain_bi);
+      data = vlib_buffer_get_current (chain_b);
+      len = chain_b->current_length;
+      if (is_in_order)
+	{
+	  rv = svm_fifo_enqueue_nowait (s->server_rx_fifo, len, data);
+	  if (rv < len)
+	    {
+	      return (rv > 0) ? (written + rv) : written;
+	    }
+	  written += rv;
+	}
+      else
+	{
+	  rv = svm_fifo_enqueue_with_offset (s->server_rx_fifo, offset, len,
+					     data);
+	  if (rv)
+	    return -1;
+	  offset += len;
+	}
+    }
+  while ((chain_bi = (chain_b->flags & VLIB_BUFFER_NEXT_PRESENT)
+	  ? chain_b->next_buffer : 0));
+
+  if (is_in_order)
+    return written;
+
+  return 0;
+}
+
 /*
  * Enqueue data for delivery to session peer. Does not notify peer of enqueue
  * event but on request can queue notification events for later delivery by
  * calling stream_server_flush_enqueue_events().
  *
  * @param tc Transport connection which is to be enqueued data
- * @param data Data to be enqueued
- * @param len Length of data to be enqueued
+ * @param b Buffer to be enqueued
+ * @param offset Offset at which to start enqueueing if out-of-order
  * @param queue_event Flag to indicate if peer is to be notified or if event
  *                    is to be queued. The former is useful when more data is
  *                    enqueued and only one event is to be generated.
+ * @param is_in_order Flag to indicate if data is in order
  * @return Number of bytes enqueued or a negative value if enqueueing failed.
  */
 int
-stream_session_enqueue_data (transport_connection_t * tc, u8 * data, u16 len,
-			     u8 queue_event)
+stream_session_enqueue_data (transport_connection_t * tc, vlib_buffer_t * b,
+			     u32 offset, u8 queue_event, u8 is_in_order)
 {
   stream_session_t *s;
-  int enqueued;
+  int enqueued = 0, rv;
 
   s = stream_session_get (tc->s_index, tc->thread_index);
 
-  /* Make sure there's enough space left. We might've filled the pipes */
-  if (PREDICT_FALSE (len > svm_fifo_max_enqueue (s->server_rx_fifo)))
-    return -1;
-
-  enqueued = svm_fifo_enqueue_nowait (s->server_rx_fifo, len, data);
+  if (is_in_order)
+    {
+      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))
+	{
+	  rv = session_enqueue_chain_tail (s, b, 0, 1);
+	  if (rv <= 0)
+	    return enqueued;
+	  enqueued += rv;
+	}
+    }
+  else
+    {
+      rv = svm_fifo_enqueue_with_offset (s->server_rx_fifo, offset,
+					 b->current_length,
+					 vlib_buffer_get_current (b));
+      if (PREDICT_FALSE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) && !rv))
+	rv = session_enqueue_chain_tail (s, b, offset + b->current_length, 0);
+      if (rv)
+	return -1;
+    }
 
   if (queue_event)
     {
@@ -476,7 +540,10 @@ stream_session_enqueue_data (transport_connection_t * tc, u8 * data, u16 len,
 	}
     }
 
-  return enqueued;
+  if (is_in_order)
+    return enqueued;
+
+  return 0;
 }
 
 /** Check if we have space in rx fifo to push more bytes */