+static_always_inline vrf_table_t *
+get_vrf_table_by_fib (u32 fib_index)
+{
+ snat_main_t *sm = &snat_main;
+ vrf_table_t *t;
+
+ pool_foreach (t, sm->vrf_tables)
+ {
+ if (fib_index == t->table_fib_index)
+ {
+ return t;
+ }
+ }
+
+ return 0;
+}
+
+static_always_inline u32
+get_tx_fib_index (u32 rx_fib_index, ip4_address_t addr)
+{
+ fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+ fib_prefix_t pfx = {
+ .fp_proto = FIB_PROTOCOL_IP4,
+ .fp_len = 32,
+ .fp_addr = {.ip4.as_u32 = addr.as_u32,}
+ ,
+ };
+
+ snat_main_t *sm = &snat_main;
+ vrf_table_t *t = get_vrf_table_by_fib (rx_fib_index);
+ // default to rx fib
+ u32 tx_fib_index = rx_fib_index;
+
+ if (0 != t)
+ {
+ // managed routes to other fibs
+ vrf_route_t *r;
+ pool_foreach (r, t->routes)
+ {
+ fei = fib_table_lookup (r->fib_index, &pfx);
+ if ((FIB_NODE_INDEX_INVALID != fei) &&
+ (~0 != fib_entry_get_resolving_interface (fei)))
+ {
+ tx_fib_index = r->fib_index;
+ break;
+ }
+ }
+ }
+ else
+ {
+ // default to configured fib
+ tx_fib_index = sm->outside_fib_index;
+
+ // default routes to other fibs
+ nat_fib_t *f;
+ vec_foreach (f, sm->outside_fibs)
+ {
+ fei = fib_table_lookup (f->fib_index, &pfx);
+ if ((FIB_NODE_INDEX_INVALID != fei) &&
+ (~0 != fib_entry_get_resolving_interface (fei)))
+ {
+ tx_fib_index = f->fib_index;
+ break;
+ }
+ }
+ }
+
+ return tx_fib_index;
+}
+
+static_always_inline int
+is_destination_resolvable (u32 rx_fib_index, ip4_address_t addr)
+{
+ fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
+ fib_prefix_t pfx = {
+ .fp_proto = FIB_PROTOCOL_IP4,
+ .fp_len = 32,
+ .fp_addr = {.ip4.as_u32 = addr.as_u32,}
+ ,
+ };
+
+ snat_main_t *sm = &snat_main;
+ vrf_table_t *t = get_vrf_table_by_fib (rx_fib_index);
+ u32 ii;
+
+ if (0 != t)
+ {
+ // managed routes to other fibs
+ vrf_route_t *r;
+ pool_foreach (r, t->routes)
+ {
+ fei = fib_table_lookup (r->fib_index, &pfx);
+ if ((FIB_NODE_INDEX_INVALID != fei) &&
+ (~0 != (ii = fib_entry_get_resolving_interface (fei))))
+ {
+ return 1;
+ }
+ }
+ }
+ else
+ {
+ // default routes to other fibs
+ nat_fib_t *f;
+ vec_foreach (f, sm->outside_fibs)
+ {
+ fei = fib_table_lookup (f->fib_index, &pfx);
+ if ((FIB_NODE_INDEX_INVALID != fei) &&
+ (~0 != (ii = fib_entry_get_resolving_interface (fei))))
+ {
+ snat_interface_t *i;
+ pool_foreach (i, sm->interfaces)
+ {
+ if ((nat44_ed_is_interface_outside (i)) &&
+ (ii == i->sw_if_index))
+ {
+ return 1;
+ }
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+