nat: sessions get expired when fib table removed

fib table removal would leave lingering sessions in vpp
this patch is aimed at solving this issue by grouping
sessions by source and destionation fib. if one of the
fibs gets removed this grouping is tagged as expired
and session won't be passed to non existing fib table

Ticket: VPPSUPP-93
Type: improvement

Change-Id: I45b1205a8b58d91f174e6feb862554ec2f6cffad
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 31 insertions, 1 deletions

diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
index ddcf4c970b0..8bec46a3704 100644
--- a/src/plugins/nat/nat.h
+++ b/src/plugins/nat/nat.h
@@ -201,6 +201,20 @@ typedef enum
 /* *INDENT-OFF* */
 typedef CLIB_PACKED(struct
 {
+  // number of sessions in this vrf
+  u32 ses_count;
+
+  u32 rx_fib_index;
+  u32 tx_fib_index;
+
+  // is this vrf expired
+  u8 expired;
+}) per_vrf_sessions_t;
+/* *INDENT-ON* */
+
+/* *INDENT-OFF* */
+typedef CLIB_PACKED(struct
+{
   /* Outside network tuple */
   struct
   {
@@ -258,10 +272,13 @@ typedef CLIB_PACKED(struct
 
   /* user index */
   u32 user_index;
+
+  /* per vrf sessions index */
+  u32 per_vrf_sessions_index;
+
 }) snat_session_t;
 /* *INDENT-ON* */
 
-
 typedef struct
 {
   ip4_address_t addr;
@@ -288,6 +305,12 @@ typedef struct
 typedef struct
 {
   u32 fib_index;
+  u32 ref_count;
+} nat_fib_t;
+
+typedef struct
+{
+  u32 fib_index;
   u32 refcount;
 } nat_outside_fib_t;
 
@@ -414,6 +437,8 @@ typedef struct
   /* real thread index */
   u32 thread_index;
 
+  per_vrf_sessions_t *per_vrf_sessions_vec;
+
 } snat_main_per_thread_data_t;
 
 struct snat_main_s;
@@ -501,6 +526,9 @@ typedef struct snat_main_s
   u16 start_port;
   u16 end_port;
 
+  /* vector of fibs */
+  nat_fib_t *fibs;
+
   /* vector of outside fibs */
   nat_outside_fib_t *outside_fibs;
 
@@ -1350,6 +1378,8 @@ int snat_alloc_outside_address_and_port (snat_address_t * addresses,
 					 u16 port_per_thread,
 					 u32 snat_thread_index);
 
+void expire_per_vrf_sessions (u32 fib_index);
+
 /**
  * @brief Match NAT44 static mapping.
  *