tcp: make syn-rcvd timeout configurable

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: Ic89570315a5c3c00e0e89c5535929313916869eb

4 files changed, 9 insertions, 1 deletions

diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c
index efc72a227e8..28d7ed9fac1 100644
--- a/src/vnet/tcp/tcp.c
+++ b/src/vnet/tcp/tcp.c
@@ -1642,6 +1642,9 @@ tcp_configuration_init (void)
 
   /* This value is seconds */
   tcp_cfg.cleanup_time = 0.1;	/* 100ms */
+
+  /* Time constants defined as tcp tick (1us) multiples */
+  tcp_cfg.syn_rcvd_time = TCP_ESTABLISH_TIME;
 }
 
 static clib_error_t *
diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h
index 2362a8bb857..3d678006f70 100644
--- a/src/vnet/tcp/tcp.h
+++ b/src/vnet/tcp/tcp.h
@@ -197,6 +197,9 @@ typedef struct tcp_configuration_
   /** Time to wait (sec) before cleaning up the connection */
   f32 cleanup_time;
 
+  /** Time to wait (tcp ticks) for syn-rcvd connection to establish */
+  u32 syn_rcvd_time;
+
   /** Number of preallocated connections */
   u32 preallocated_connections;
 
diff --git a/src/vnet/tcp/tcp_cli.c b/src/vnet/tcp/tcp_cli.c
index b04c0bdc0cf..e26488342d2 100644
--- a/src/vnet/tcp/tcp_cli.c
+++ b/src/vnet/tcp/tcp_cli.c
@@ -1009,6 +1009,8 @@ tcp_config_fn (vlib_main_t * vm, unformat_input_t * input)
 	tcp_cfg.alloc_err_timeout = tmp_time / TCP_TIMER_TICK;
       else if (unformat (input, "cleanup-time %u", &tmp_time))
 	tcp_cfg.cleanup_time = tmp_time / 1000.0;
+      else if (unformat (input, "syn-rcvd-time %u", &tmp_time))
+	tcp_cfg.syn_rcvd_time = tmp_time * THZ;
       else
 	return clib_error_return (0, "unknown input `%U'",
 				  format_unformat_error, input);
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 78148cd5695..373bb2a9e0f 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -1391,7 +1391,7 @@ tcp_timer_retransmit_handler (tcp_connection_t * tc)
       tc->rtt_ts = 0;
 
       /* Passive open establish timeout */
-      if (tc->rto > TCP_ESTABLISH_TIME >> 1)
+      if (tc->rto > tcp_cfg.syn_rcvd_time >> 1)
 	{
 	  tcp_connection_set_state (tc, TCP_STATE_CLOSED);
 	  tcp_connection_timers_reset (tc);