tcp: track reorder with sacks

[vpp.git] / src / vnet / tcp / tcp_output.c

diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 6bcca31..294b18c 100644 (file)
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -120,11 +120,6 @@ tcp_update_rcv_wnd (tcp_connection_t * tc)
    * Figure out how much space we have available
    */
   available_space = transport_max_rx_enqueue (&tc->connection);
-  if (PREDICT_FALSE (available_space < tc->rcv_opts.mss))
-    {
-      tc->rcv_wnd = 0;
-      return;
-    }
 
   /*
    * Use the above and what we know about what we've previously advertised
@@ -132,22 +127,22 @@ tcp_update_rcv_wnd (tcp_connection_t * tc)
    */
   observed_wnd = (i32) tc->rcv_wnd - (tc->rcv_nxt - tc->rcv_las);
 
-  /* Bad. Thou shalt not shrink */
+  /* Check if we are about to retract the window. Do the comparison before
+   * rounding to avoid errors. Per RFC7323 sec. 2.4 we could remove this */
   if (PREDICT_FALSE ((i32) available_space < observed_wnd))
     {
-      wnd = clib_max (observed_wnd, 0);
+      wnd = round_down_pow2 (clib_max (observed_wnd, 0), 1 << tc->rcv_wscale);
       TCP_EVT (TCP_EVT_RCV_WND_SHRUNK, tc, observed_wnd, available_space);
     }
   else
     {
-      wnd = available_space;
+      /* Make sure we have a multiple of 1 << rcv_wscale. We round down to
+       * avoid advertising a window larger than what can be buffered */
+      wnd = round_down_pow2 (available_space, 1 << tc->rcv_wscale);
     }
 
-  /* Make sure we have a multiple of 1 << rcv_wscale. We round up to
-   * avoid advertising a window less than mss which could happen if
-   * 1 << rcv_wscale < mss */
-  if (wnd && tc->rcv_wscale)
-    wnd = round_pow2 (wnd, 1 << tc->rcv_wscale);
+  if (PREDICT_FALSE (wnd < tc->rcv_opts.mss))
+    wnd = 0;
 
   tc->rcv_wnd = clib_min (wnd, TCP_WND_MAX << tc->rcv_wscale);
 }
@@ -669,7 +664,10 @@ tcp_send_reset_w_pkt (tcp_connection_t * tc, vlib_buffer_t * pkt,
   fib_protocol_t fib_proto;
 
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
-    return;
+    {
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
+      return;
+    }
 
   b = vlib_get_buffer (vm, bi);
   sw_if_index = vnet_buffer (pkt)->sw_if_index[VLIB_RX];
@@ -750,7 +748,10 @@ tcp_send_reset (tcp_connection_t * tc)
   u8 flags;
 
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
-    return;
+    {
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
+      return;
+    }
   b = vlib_get_buffer (vm, bi);
   tcp_init_buffer (vm, b);
 
@@ -812,6 +813,7 @@ tcp_send_syn (tcp_connection_t * tc)
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
       tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN, 1);
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
       return;
     }
 
@@ -842,6 +844,7 @@ tcp_send_synack (tcp_connection_t * tc)
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
       tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT, 1);
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
       return;
     }
 
@@ -878,6 +881,7 @@ tcp_send_fin (tcp_connection_t * tc)
       else
        /* Make sure retransmit retries a fin not data */
        tc->flags |= TCP_CONN_FINSNT;
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
       return;
     }
 
@@ -1018,6 +1022,7 @@ tcp_send_ack (tcp_connection_t * tc)
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
       tcp_update_rcv_wnd (tc);
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
       return;
     }
   b = vlib_get_buffer (vm, bi);
@@ -1058,17 +1063,6 @@ tcp_program_retransmit (tcp_connection_t * tc)
     }
 }
 
-/**
- * Delayed ack timer handler
- *
- * Sends delayed ACK when timer expires
- */
-void
-tcp_timer_delack_handler (tcp_connection_t * tc)
-{
-  tcp_send_ack (tc);
-}
-
 /**
  * Send window update ack
  *
@@ -1127,7 +1121,10 @@ tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
   if (PREDICT_TRUE (seg_size <= bytes_per_buffer))
     {
       if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
-       return 0;
+       {
+         tcp_worker_stats_inc (wrk, no_buffer, 1);
+         return 0;
+       }
       *b = vlib_get_buffer (vm, bi);
       data = tcp_init_buffer (vm, *b);
       n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
@@ -1154,6 +1151,7 @@ tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
        {
          if (n_bufs)
            vlib_buffer_free (vm, wrk->tx_buffers, n_bufs);
+         tcp_worker_stats_inc (wrk, no_buffer, 1);
          return 0;
        }
 
@@ -1292,6 +1290,7 @@ tcp_cc_init_rxt_timeout (tcp_connection_t * tc)
   tc->rtt_ts = 0;
   tc->cwnd_acc_bytes = 0;
   tc->tr_occurences += 1;
+  tc->sack_sb.reorder = TCP_DUPACK_THRESHOLD;
   tcp_recovery_on (tc);
 }
 
@@ -1415,6 +1414,7 @@ tcp_timer_retransmit_handler (tcp_connection_t * tc)
       if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
        {
          tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT, 1);
+         tcp_worker_stats_inc (wrk, no_buffer, 1);
          return;
        }
 
@@ -1478,6 +1478,7 @@ tcp_timer_retransmit_syn_handler (tcp_connection_t * tc)
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
       tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT_SYN, 1);
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
       return;
     }
 
@@ -1545,6 +1546,7 @@ tcp_timer_persist_handler (tcp_connection_t * tc)
   if (PREDICT_FALSE (!vlib_buffer_alloc (vm, &bi, 1)))
     {
       tcp_persist_timer_set (&wrk->timer_wheel, tc);
+      tcp_worker_stats_inc (wrk, no_buffer, 1);
       return;
     }