tcp: avoid fr segments less than mss if possible

[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 c994845..78148cd 100644 (file)
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -838,10 +838,9 @@ tcp_send_fin (tcp_connection_t * tc)
       /* Out of buffers so program fin retransmit ASAP */
       tcp_timer_update (&wrk->timer_wheel, tc, TCP_TIMER_RETRANSMIT,
                        tcp_cfg.alloc_err_timeout);
-      if (fin_snt)
-       tc->snd_nxt += 1;
-      else
-       /* Make sure retransmit retries a fin not data */
+      tc->snd_nxt += 1;
+      /* Make sure retransmit retries a fin not data with right snd_nxt */
+      if (!fin_snt)
        tc->flags |= TCP_CONN_FINSNT;
       tcp_worker_stats_inc (wrk, no_buffer, 1);
       return;
@@ -1117,7 +1116,7 @@ tcp_prepare_segment (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
       data = tcp_init_buffer (vm, *b);
       n_bytes = session_tx_fifo_peek_bytes (&tc->connection, data, offset,
                                            max_deq_bytes);
-      ASSERT (n_bytes == max_deq_bytes);
+      ASSERT (n_bytes > 0);
       b[0]->current_length = n_bytes;
       tcp_push_hdr_i (tc, *b, tc->snd_una + offset, /* compute opts */ 0,
                      /* burst */ 0, /* update_snd_nxt */ 0);
@@ -1762,7 +1761,7 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
       if (!hole)
        {
          /* We are out of lost holes to retransmit so send some new data. */
-         if (max_deq > tc->snd_mss)
+         if (max_deq)
            {
              u32 n_segs_new;
              int av_wnd;
@@ -1772,7 +1771,10 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
              av_wnd = (int) tc->snd_wnd - (tc->snd_nxt - tc->snd_una);
              av_wnd = clib_max (av_wnd - tc->snd_mss, 0);
              snd_space = clib_min (snd_space, av_wnd);
-             snd_space = clib_min (max_deq, snd_space);
+             /* Low bound max_deq to mss to be able to send a segment even
+              * when it is less than mss */
+             snd_space =
+               clib_min (clib_max (max_deq, tc->snd_mss), snd_space);
              burst_size = clib_min (burst_size - n_segs,
                                     snd_space / tc->snd_mss);
              burst_size = clib_min (burst_size, TCP_RXT_MAX_BURST);
@@ -1808,7 +1810,11 @@ tcp_retransmit_sack (tcp_worker_ctx_t * wrk, tcp_connection_t * tc,
          break;
        }
 
-      max_bytes = clib_min (hole->end - sb->high_rxt, snd_space);
+      max_bytes = hole->end - sb->high_rxt;
+      /* Avoid retransmitting segment less than mss if possible */
+      if (snd_space < tc->snd_mss && max_bytes > snd_space)
+       break;
+      max_bytes = clib_min (max_bytes, snd_space);
       max_bytes = snd_limited ? clib_min (max_bytes, tc->snd_mss) : max_bytes;
       if (max_bytes == 0)
        break;
@@ -2293,7 +2299,6 @@ VLIB_NODE_FN (tcp6_output_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
   return tcp46_output_inline (vm, node, from_frame, 0 /* is_ip4 */ );
 }
 
-/* *INDENT-OFF* */
 VLIB_REGISTER_NODE (tcp4_output_node) =
 {
   .name = "tcp4-output",
@@ -2311,9 +2316,7 @@ VLIB_REGISTER_NODE (tcp4_output_node) =
   .format_buffer = format_tcp_header,
   .format_trace = format_tcp_tx_trace,
 };
-/* *INDENT-ON* */
 
-/* *INDENT-OFF* */
 VLIB_REGISTER_NODE (tcp6_output_node) =
 {
   .name = "tcp6-output",
@@ -2331,7 +2334,6 @@ VLIB_REGISTER_NODE (tcp6_output_node) =
   .format_buffer = format_tcp_header,
   .format_trace = format_tcp_tx_trace,
 };
-/* *INDENT-ON* */
 
 typedef enum _tcp_reset_next
 {
@@ -2442,7 +2444,6 @@ VLIB_NODE_FN (tcp6_reset_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
   return tcp46_reset_inline (vm, node, from_frame, 0);
 }
 
-/* *INDENT-OFF* */
 VLIB_REGISTER_NODE (tcp4_reset_node) = {
   .name = "tcp4-reset",
   .vector_size = sizeof (u32),
@@ -2456,9 +2457,7 @@ VLIB_REGISTER_NODE (tcp4_reset_node) = {
   },
   .format_trace = format_tcp_tx_trace,
 };
-/* *INDENT-ON* */
 
-/* *INDENT-OFF* */
 VLIB_REGISTER_NODE (tcp6_reset_node) = {
   .name = "tcp6-reset",
   .vector_size = sizeof (u32),
@@ -2472,7 +2471,6 @@ VLIB_REGISTER_NODE (tcp6_reset_node) = {
   },
   .format_trace = format_tcp_tx_trace,
 };
-/* *INDENT-ON* */
 
 /*
  * fd.io coding-style-patch-verification: ON