nat: configurable handoff frame queue size

Make number of worker handoff frame queue elements configurable as
a set nat frame-queue-nelts command. The default value is 64 which
is the same value that was previously hard-coded. The idea is that
allowing larger values can be useful in some cases, to avoid
congestion drops. Also add nat_set_fq_options API support and a
corresponding test case.

Type: improvement

Change-Id: I5c321eb2d7997f76fac2703d9c4a5b2516375db3
Signed-off-by: Elias Rudberg <elias.rudberg@bahnhof.net>

1 files changed, 48 insertions, 0 deletions

diff --git a/src/plugins/nat/nat44_cli.c b/src/plugins/nat/nat44_cli.c
index c89963ec85a..68c53d05389 100644
--- a/src/plugins/nat/nat44_cli.c
+++ b/src/plugins/nat/nat44_cli.c
@@ -1892,6 +1892,42 @@ nat_show_timeouts_command_fn (vlib_main_t * vm,
 }
 
 static clib_error_t *
+set_frame_queue_nelts_command_fn (vlib_main_t *vm, unformat_input_t *input,
+				  vlib_cli_command_t *cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+  u32 frame_queue_nelts = 0;
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "%u", &frame_queue_nelts))
+	;
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+  if (!frame_queue_nelts)
+    {
+      error = clib_error_return (0, "frame_queue_nelts cannot be zero");
+      goto done;
+    }
+  if (snat_set_frame_queue_nelts (frame_queue_nelts) != 0)
+    {
+      error = clib_error_return (0, "snat_set_frame_queue_nelts failed");
+      goto done;
+    }
+done:
+  unformat_free (line_input);
+  return error;
+}
+
+static clib_error_t *
 nat44_debug_fib_expire_command_fn (vlib_main_t * vm,
 				   unformat_input_t * input,
 				   vlib_cli_command_t * cmd)
@@ -2067,6 +2103,18 @@ VLIB_CLI_COMMAND (nat_show_timeouts_command, static) = {
 
 /*?
  * @cliexpar
+ * @cliexstart{set nat frame-queue-nelts}
+ * Set number of worker handoff frame queue elements.
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (set_frame_queue_nelts_command, static) = {
+  .path = "set nat frame-queue-nelts",
+  .function = set_frame_queue_nelts_command_fn,
+  .short_help = "set nat frame-queue-nelts <number>",
+};
+
+/*?
+ * @cliexpar
  * @cliexstart{nat set logging level}
  * To set NAT logging level use:
  * Set nat logging level