Improve sack bytes accounting and testing

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

diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index ddee41e..9d3f4cc 100644 (file)
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -533,12 +533,13 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
   sack_scoreboard_t *sb = &tc->sack_sb;
   sack_block_t *blk, tmp;
   sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole;
-  u32 blk_index = 0, old_sacked_bytes, hole_index;
+  u32 blk_index = 0, old_sacked_bytes, delivered_bytes, hole_index;
   int i, j;
 
   sb->last_sacked_bytes = 0;
   sb->snd_una_adv = 0;
   old_sacked_bytes = sb->sacked_bytes;
+  delivered_bytes = 0;
 
   if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX)
     return;
@@ -584,6 +585,8 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
       last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX,
                                          tc->snd_una, tc->snd_una_max);
       sb->tail = scoreboard_hole_index (sb, last_hole);
+      tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1];
+      sb->max_byte_sacked = tmp.end;
     }
   else
     {
@@ -614,37 +617,43 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
                {
                  /* Bytes lost because snd_wnd left edge advances */
                  if (next_hole && seq_leq (next_hole->start, ack))
-                   sb->sacked_bytes -= next_hole->start - hole->end;
+                   delivered_bytes += next_hole->start - hole->end;
                  else
-                   sb->sacked_bytes -= ack - hole->end;
+                   delivered_bytes += ack - hole->end;
                }
              else
                {
                  sb->sacked_bytes += scoreboard_hole_bytes (hole);
                }
 
-             /* snd_una needs to be advanced */
-             if (seq_geq (ack, hole->end))
-               {
-                 if (next_hole && seq_lt (ack, next_hole->start))
-                   sb->snd_una_adv = next_hole->start - ack;
-                 else
-                   sb->snd_una_adv = sb->max_byte_sacked - ack;
-
-                 /* all these can be delivered */
-                 sb->sacked_bytes -= sb->snd_una_adv;
-               }
-
              /* About to remove last hole */
              if (hole == last_hole)
                {
                  sb->tail = hole->prev;
                  last_hole = scoreboard_last_hole (sb);
-                 /* keep track of max byte sacked in case the last hole
+                 /* keep track of max byte sacked for when the last hole
                   * is acked */
                  if (seq_gt (hole->end, sb->max_byte_sacked))
                    sb->max_byte_sacked = hole->end;
                }
+
+             /* snd_una needs to be advanced */
+             if (blk->end == ack && seq_geq (ack, hole->end))
+               {
+                 if (next_hole && seq_lt (ack, next_hole->start))
+                   {
+                     sb->snd_una_adv = next_hole->start - ack;
+
+                     /* all these can be delivered */
+                     delivered_bytes += sb->snd_una_adv;
+                   }
+                 else if (!next_hole)
+                   {
+                     sb->snd_una_adv = sb->max_byte_sacked - ack;
+                     delivered_bytes += sb->snd_una_adv;
+                   }
+               }
+
              scoreboard_remove_hole (sb, hole);
              hole = next_hole;
            }
@@ -693,8 +702,8 @@ tcp_rcv_sacks (tcp_connection_t * tc, u32 ack)
        }
     }
 
-  sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv
-    - old_sacked_bytes;
+  sb->last_sacked_bytes = sb->sacked_bytes - old_sacked_bytes;
+  sb->sacked_bytes -= delivered_bytes;
 }
 
 /** Update snd_wnd