tcp: track lost rxt segments in byte tracker

Type: feature

Change-Id: I18dfac9c3d2f539edf20dba64cd2b7b541154144
Signed-off-by: Florin Coras <fcoras@cisco.com>

src/vnet/tcp/tcp.h

@@ -256,6 +256,7 @@ typedef enum tcp_bts_flags_
   TCP_BTS_IS_RXT = 1,
   TCP_BTS_IS_APP_LIMITED = 1 << 1,
   TCP_BTS_IS_SACKED = 1 << 2,
+  TCP_BTS_IS_RXT_LOST = 1 << 3,
 } __clib_packed tcp_bts_flags_t;
 
 typedef struct tcp_bt_sample_

src/vnet/tcp/tcp_bt.c

@@ -368,6 +368,8 @@ tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end)
 
       cur = tcp_bt_alloc_tx_sample (tc, start, end);
       cur->flags |= TCP_BTS_IS_RXT;
+      if (bts->flags & TCP_BTS_IS_RXT)
+	cur->flags |= TCP_BTS_IS_RXT_LOST;
       cur->next = next_index;
       cur->prev = prev_index;
 
@@ -408,6 +410,8 @@ tcp_bt_track_rxt (tcp_connection_t * tc, u32 start, u32 end)
   /* Have to split or tail overlap */
   cur = tcp_bt_alloc_tx_sample (tc, start, end);
   cur->flags |= TCP_BTS_IS_RXT;
+  if (bts->flags & TCP_BTS_IS_RXT)
+    cur->flags |= TCP_BTS_IS_RXT_LOST;
   cur->prev = bts_index;
   cur_index = bt_sample_index (bt, cur);