nat: nat44 enable/disable dynamic config

This patch changes initialization and configuration of NAT
plugin. Instead of allocating data structures at vpp plugin
initialization phase allocation and configuration happens
after calling enable API or CLI call. This reduces base VPP
memory footprint and also enables dynamic reconfiguration
of the NAT plugin.

Type: improvement
Change-Id: I42c069ee19a0311d043ac1f3f230d87bc8d2680f
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 133 insertions, 0 deletions

diff --git a/src/plugins/nat/nat44_cli.c b/src/plugins/nat/nat44_cli.c
index 680a1e2a18a..a84c8204143 100644
--- a/src/plugins/nat/nat44_cli.c
+++ b/src/plugins/nat/nat44_cli.c
@@ -32,6 +32,97 @@
   "This command is supported only in endpoint dependent mode"
 
 static clib_error_t *
+nat44_enable_command_fn (vlib_main_t * vm,
+			 unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
+
+  nat44_config_t c = { 0 };
+  u8 mode_set = 0;
+
+  // TODO: check this also inside the function so it can be
+  //       safely called from anyplace, also sanity checking required
+  if (sm->enabled)
+    return clib_error_return (0, "nat44 already enabled");
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    {
+      if (nat44_plugin_enable (c) != 0)
+	return clib_error_return (0, "nat44 enable failed");
+      return 0;
+    }
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (!mode_set && unformat (line_input, "static-mapping-only"))
+	{
+	  mode_set = 1;
+	  c.static_mapping_only = 1;
+	  if (unformat (line_input, "connection-tracking"))
+	    {
+	      c.connection_tracking = 1;
+	    }
+	}
+      else if (!mode_set && unformat (line_input, "out2in-dpo"))
+	{
+	  mode_set = 1;
+	  c.out2in_dpo = 1;
+	}
+      else if (!mode_set && unformat (line_input, "endpoint-dependent"))
+	{
+	  mode_set = 1;
+	  c.endpoint_dependent = 1;
+	}
+      else if (unformat (input, "inside-vrf %u", &c.inside_vrf));
+      else if (unformat (input, "outside-vrf %u", &c.outside_vrf));
+      else if (unformat (input, "users %u", &c.users));
+      else if (unformat (input, "user-memory %u", &c.user_memory));
+      else if (unformat (input, "sessions %u", &c.sessions));
+      else if (unformat (input, "session-memory %u", &c.session_memory));
+      else if (unformat (input, "user-sessions %u", &c.user_sessions));
+      else
+	{
+	  error = clib_error_return (0, "unknown input '%U'",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
+    }
+
+  if (!(c.sessions && c.session_memory))
+    {
+      error =
+	clib_error_return (0,
+			   "either number of sessions or size of the memory is required");
+      goto done;
+    }
+
+  if (nat44_plugin_enable (c) != 0)
+    error = clib_error_return (0, "nat44 enable failed");
+done:
+  unformat_free (line_input);
+  return error;
+}
+
+static clib_error_t *
+nat44_disable_command_fn (vlib_main_t * vm,
+			  unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  snat_main_t *sm = &snat_main;
+  clib_error_t *error = 0;
+
+  if (sm->enabled)
+    return clib_error_return (0, "nat44 already disabled");
+
+  if (nat44_plugin_disable () != 0)
+    error = clib_error_return (0, "nat44 disable failed");
+
+  return error;
+}
+
+static clib_error_t *
 set_workers_command_fn (vlib_main_t * vm,
 			unformat_input_t * input, vlib_cli_command_t * cmd)
 {
@@ -1891,6 +1982,48 @@ VLIB_CLI_COMMAND (nat44_debug_fib_registration_command, static) = {
 
 /*?
  * @cliexpar
+ * @cliexstart{nat44 enable}
+ * Enable nat44 plugin
+ * To enable nat44, use:
+ *  vpp# nat44 enable sessions <n>
+ * To enable nat44 static mapping only, use:
+ *  vpp# nat44 enable sessions <n> static-mapping
+ * To enable nat44 static mapping with connection tracking, use:
+ *  vpp# nat44 enable sessions <n> static-mapping connection-tracking
+ * To enable nat44 out2in dpo, use:
+ *  vpp# nat44 enable sessions <n> out2in-dpo
+ * To enable nat44 endpoint-dependent, use:
+ *  vpp# nat44 enable sessions <n> endpoint-dependent
+ * To overwrite user hash configuration, use:
+ *  vpp# nat44 enable sessions <n> user-memory <n>
+ * To overwrite session hash configuration, use:
+ *  vpp# nat44 enable session-memory <n>
+ * To set inside-vrf outside-vrf, use:
+ *  vpp# nat44 enable sessions <n> inside-vrf <id> outside-vrf <id>
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (nat44_enable_command, static) = {
+  .path = "nat44 enable",
+  .short_help = "nat44 enable sessions <max-number> [users <max-number>] [static-mappig-only [connection-tracking]|out2in-dpo|endpoint-dependent] [inside-vrf <vrf-id>] [outside-vrf <vrf-id>] [user-memory <number>] [session-memory <number>] [user-sessions <max-number>]",
+  .function = nat44_enable_command_fn,
+};
+
+/*?
+ * @cliexpar
+ * @cliexstart{nat44 disable}
+ * Disable nat44 plugin
+ * To disable nat44, use:
+ *  vpp# nat44 disable
+ * @cliexend
+?*/
+VLIB_CLI_COMMAND (nat44_disable_command, static) = {
+  .path = "nat44 disable",
+  .short_help = "nat44 disable",
+  .function = nat44_disable_command_fn,
+};
+
+/*?
+ * @cliexpar
  * @cliexstart{set snat workers}
  * Set NAT workers if 2 or more workers available, use:
  *  vpp# set snat workers 0-2,5