tcp: add option to cfg max rx fifo size

Change-Id: Icff3d688506e7658330db004c58bcfcac273fcec
Signed-off-by: Florin Coras <fcoras@cisco.com>

3 files changed, 22 insertions, 10 deletions

diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c
index 45eaf016b1e..d00f4abb118 100644
--- a/src/vnet/tcp/tcp.c
+++ b/src/vnet/tcp/tcp.c
@@ -765,8 +765,9 @@ format_tcp_vars (u8 * s, va_list * args)
 	      tc->snd_una_max - tc->iss);
   s = format (s, " rcv_nxt %u rcv_las %u\n",
 	      tc->rcv_nxt - tc->irs, tc->rcv_las - tc->irs);
-  s = format (s, " snd_wnd %u rcv_wnd %u snd_wl1 %u snd_wl2 %u\n",
-	      tc->snd_wnd, tc->rcv_wnd, tc->snd_wl1 - tc->irs,
+  s = format (s, " snd_wnd %u rcv_wnd %u rcv_wscale %u ",
+	      tc->snd_wnd, tc->rcv_wnd, tc->rcv_wscale);
+  s = format (s, "snd_wl1 %u snd_wl2 %u\n", tc->snd_wl1 - tc->irs,
 	      tc->snd_wl2 - tc->iss);
   s = format (s, " flight size %u out space %u cc space %u rcv_wnd_av %u\n",
 	      tcp_flight_size (tc), tcp_available_output_snd_space (tc),
@@ -1388,9 +1389,8 @@ tcp_config_fn (vlib_main_t * vm, unformat_input_t * input)
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
-      if (unformat
-	  (input, "preallocated-connections %d",
-	   &tm->preallocated_connections))
+      if (unformat (input, "preallocated-connections %d",
+		    &tm->preallocated_connections))
 	;
       else if (unformat (input, "preallocated-half-open-connections %d",
 			 &tm->preallocated_half_open_connections))
@@ -1398,6 +1398,9 @@ tcp_config_fn (vlib_main_t * vm, unformat_input_t * input)
       else if (unformat (input, "buffer-fail-fraction %f",
 			 &tm->buffer_fail_fraction))
 	;
+      else if (unformat (input, "max-rx-fifo %U", unformat_memory_size,
+			 &tm->max_rx_fifo))
+	;
       else
 	return clib_error_return (0, "unknown input `%U'",
 				  format_unformat_error, input);
diff --git a/src/vnet/tcp/tcp.h b/src/vnet/tcp/tcp.h
index e4168c4b701..37b4573cf25 100644
--- a/src/vnet/tcp/tcp.h
+++ b/src/vnet/tcp/tcp.h
@@ -32,7 +32,7 @@
 #define TCP_MAX_OPTION_SPACE 40
 
 #define TCP_DUPACK_THRESHOLD 	3
-#define TCP_MAX_RX_FIFO_SIZE 	4 << 20
+#define TCP_MAX_RX_FIFO_SIZE 	32 << 20
 #define TCP_MIN_RX_FIFO_SIZE	4 << 10
 #define TCP_IW_N_SEGMENTS 	10
 #define TCP_ALWAYS_ACK		1	/**< On/off delayed acks */
@@ -408,9 +408,20 @@ typedef struct _tcp_main
   /* Congestion control algorithms registered */
   tcp_cc_algorithm_t *cc_algos;
 
+  /** vlib buffer size */
+  u32 bytes_per_buffer;
+
+  /*
+   * Configuration
+   */
+
   /* Flag that indicates if stack is on or off */
   u8 is_enabled;
 
+  /** Max rx fifo size for a session. It is used in to compute the
+   *  rfc 7323 window scaling factor */
+  u32 max_rx_fifo;
+
   /** Number of preallocated connections */
   u32 preallocated_connections;
   u32 preallocated_half_open_connections;
@@ -421,9 +432,6 @@ typedef struct _tcp_main
   u32 last_v6_address_rotor;
   ip6_address_t *ip6_src_addresses;
 
-  /** vlib buffer size */
-  u32 bytes_per_buffer;
-
   u8 punt_unknown4;
   u8 punt_unknown6;
 
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index f37958e12f2..0d5feb976f8 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -118,12 +118,13 @@ tcp_initial_wnd_unscaled (tcp_connection_t * tc)
 u32
 tcp_initial_window_to_advertise (tcp_connection_t * tc)
 {
+  tcp_main_t *tm = &tcp_main;
   u32 max_fifo;
 
   /* Initial wnd for SYN. Fifos are not allocated yet.
    * Use some predefined value. For SYN-ACK we still want the
    * scale to be computed in the same way */
-  max_fifo = TCP_MAX_RX_FIFO_SIZE;
+  max_fifo = tm->max_rx_fifo ? tm->max_rx_fifo : TCP_MAX_RX_FIFO_SIZE;
 
   tc->rcv_wscale = tcp_window_compute_scale (max_fifo);
   tc->rcv_wnd = tcp_initial_wnd_unscaled (tc);