tcp: allow unsent segments less than mss in recovery

[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..069c349 100644 (file)
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -1117,7 +1117,8 @@ 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 == clib_min (max_deq_bytes, transport_max_tx_dequeue (
+                                                   &tc->connection)));
       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 +1763,7 @@ 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 +1773,10 @@ 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);