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, 77 insertions, 9 deletions

diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
index 123bea57a81..2d16507df7a 100644
--- a/src/plugins/nat/nat.h
+++ b/src/plugins/nat/nat.h
@@ -48,6 +48,44 @@
 /* NAT buffer flags */
 #define SNAT_FLAG_HAIRPINNING (1 << 0)
 
+/* NAT44 API Configuration flags */
+#define foreach_nat44_config_flag  \
+  _(0x00, IS_ENDPOINT_INDEPENDENT) \
+  _(0x01, IS_ENDPOINT_DEPENDENT)   \
+  _(0x02, IS_STATIC_MAPPING_ONLY)  \
+  _(0x04, IS_CONNECTION_TRACKING)  \
+  _(0x08, IS_OUT2IN_DPO)
+
+typedef enum nat44_config_flags_t_
+{
+#define _(n,f) NAT44_API_##f = n,
+  foreach_nat44_config_flag
+#undef _
+} nat44_config_flags_t;
+
+typedef struct
+{
+  /* nat44 plugin features */
+  u8 static_mapping_only;
+  u8 connection_tracking;
+  u8 endpoint_dependent;
+  u8 out2in_dpo;
+
+  u32 inside_vrf;
+  u32 outside_vrf;
+
+  /* maximum number of users */
+  u32 users;
+  u32 user_memory;
+
+  /* maximum number of sessions */
+  u32 sessions;
+  u32 session_memory;
+
+  /* maximum number of ssessions per user */
+  u32 user_sessions;
+} nat44_config_t;
+
 typedef enum
 {
   NAT_NEXT_DROP,
@@ -551,16 +589,24 @@ typedef struct snat_main_s
   u32 pre_out2in_node_index;
   u32 pre_in2out_node_index;
 
+  u32 out2in_node_index;
   u32 in2out_node_index;
   u32 in2out_output_node_index;
+
   u32 in2out_fast_node_index;
   u32 in2out_slowpath_node_index;
   u32 in2out_slowpath_output_node_index;
-  u32 ed_in2out_node_index;
-  u32 ed_in2out_slowpath_node_index;
-  u32 out2in_node_index;
   u32 out2in_fast_node_index;
+
+  u32 ei_out2in_node_index;
+  u32 ei_in2out_node_index;
+  u32 ei_in2out_output_node_index;
+
   u32 ed_out2in_node_index;
+  u32 ed_in2out_node_index;
+  u32 ed_in2out_output_node_index;
+
+  u32 ed_in2out_slowpath_node_index;
   u32 ed_out2in_slowpath_node_index;
 
   u32 hairpinning_node_index;
@@ -574,10 +620,12 @@ typedef struct snat_main_s
   u8 forwarding_enabled;
 
   /* Config parameters */
+  u8 endpoint_dependent;
+
+  u8 out2in_dpo;
+  /* static mapping config */
   u8 static_mapping_only;
   u8 static_mapping_connection_tracking;
-  u8 out2in_dpo;
-  u8 endpoint_dependent;
 
   /* Is translation memory size calculated or user defined */
   u8 translation_memory_size_set;
@@ -597,7 +645,6 @@ typedef struct snat_main_s
   u32 inside_fib_index;
 
   /* values of various timeouts */
-  // proto timeouts
   u32 udp_timeout;
   u32 tcp_transitory_timeout;
   u32 tcp_established_timeout;
@@ -606,7 +653,7 @@ typedef struct snat_main_s
   /* TCP MSS clamping */
   u16 mss_clamping;
 
-  /* counters/gauges */
+  /* counters */
   vlib_simple_counter_main_t total_users;
   vlib_simple_counter_main_t total_sessions;
   vlib_simple_counter_main_t user_limit_reached;
@@ -673,10 +720,14 @@ typedef struct snat_main_s
   u8 log_level;
 
   /* convenience */
-  vnet_main_t *vnet_main;
+  api_main_t *api_main;
   ip4_main_t *ip4_main;
   ip_lookup_main_t *ip4_lookup_main;
-  api_main_t *api_main;
+
+  /* nat44 plugin enabled */
+  u8 enabled;
+
+  vnet_main_t *vnet_main;
 } snat_main_t;
 
 typedef struct
@@ -1087,6 +1138,23 @@ int nat44_o2i_ed_is_idle_session_cb (clib_bihash_kv_16_8_t * kv, void *arg);
 int nat44_i2o_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg);
 int nat44_o2i_is_idle_session_cb (clib_bihash_kv_8_8_t * kv, void *arg);
 
+
+/**
+ * @brief Enable NAT44 plugin
+ *
+ * @param c         nat44_config_t
+ *
+ * @return 0 on success, non-zero value otherwise
+ */
+int nat44_plugin_enable (nat44_config_t c);
+
+/**
+ * @brief Disable NAT44 plugin
+ *
+ * @return 0 on success, non-zero value otherwise
+ */
+int nat44_plugin_disable ();
+
 /**
  * @brief Add external address to NAT44 pool
  *