Implement sack based tcp loss recovery (RFC 6675)

- refactor existing congestion control code (RFC 6582/5681). Handling of ack
  feedback now consists of: ack parsing, cc event detection, event handling,
  congestion control update
- extend sack scoreboard to support sack based retransmissions
- basic implementation of Eifel detection algorithm (RFC 3522) for
  detecting spurious retransmissions
- actually initialize the per-thread frame freelist hash tables
- increase worker stack size to 2mb
- fix session queue node out-of-buffer handling
  - ensure that the local buffer cache vec_len matches reality
  - avoid 2x spurious event requeues when short of buffers
  - count out-of-buffer events
- make the builtin server thread-safe
- fix bihash template threading issue: need to paint -1 across uninitialized
  working_copy_length vector elements (via rebase from master)

Change-Id: I646cb9f1add9a67d08f4a87badbcb117980ebfc4
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Dave Barach <dbarach@cisco.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index a87286498de..d9c38bd1ad8 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -352,16 +352,18 @@ stream_session_max_rx_enqueue (transport_connection_t * tc)
 }
 
 always_inline u32
-stream_session_fifo_size (transport_connection_t * tc)
+stream_session_rx_fifo_size (transport_connection_t * tc)
 {
   stream_session_t *s = stream_session_get (tc->s_index, tc->thread_index);
   return s->server_rx_fifo->nitems;
 }
 
+u32 stream_session_tx_fifo_max_dequeue (transport_connection_t * tc);
+
 int
 stream_session_enqueue_data (transport_connection_t * tc, vlib_buffer_t * b,
 			     u32 offset, u8 queue_event, u8 is_in_order);
-u32
+int
 stream_session_peek_bytes (transport_connection_t * tc, u8 * buffer,
 			   u32 offset, u32 max_bytes);
 u32 stream_session_dequeue_drop (transport_connection_t * tc, u32 max_bytes);