nat: move nat64 to a subfeature

Type: refactor

Change-Id: I3b9e17164647d2019b1f40cffeed63393345219e
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 742 insertions, 0 deletions

diff --git a/src/plugins/nat/nat64/nat64_db.c b/src/plugins/nat/nat64/nat64_db.c
new file mode 100644
index 00000000000..ffc5e7e7e84
--- /dev/null
+++ b/src/plugins/nat/nat64/nat64_db.c
@@ -0,0 +1,742 @@
+/*
+ * Copyright (c) 2020 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_table.h>
+//#include <nat/nat_ipfix_logging.h>
+#include <nat/nat_syslog.h>
+#include <nat/lib/inlines.h>
+#include <nat/nat64/nat64_db.h>
+
+int
+nat64_db_init (nat64_db_t * db, nat64_config_t c,
+	       nat64_db_free_addr_port_function_t free_addr_port_cb)
+{
+  clib_bihash_init_24_8 (&db->bib.in2out, "bib-in2out", c.bib_buckets,
+			 c.bib_memory_size);
+
+  clib_bihash_init_24_8 (&db->bib.out2in, "bib-out2in", c.bib_buckets,
+			 c.bib_memory_size);
+
+  clib_bihash_init_48_8 (&db->st.in2out, "st-in2out", c.st_buckets,
+			 c.st_memory_size);
+
+  clib_bihash_init_48_8 (&db->st.out2in, "st-out2in", c.st_buckets,
+			 c.st_memory_size);
+
+  db->free_addr_port_cb = free_addr_port_cb;
+  db->bib.limit = 10 * c.bib_buckets;
+  db->bib.bib_entries_num = 0;
+  db->st.limit = 10 * c.st_buckets;
+  db->st.st_entries_num = 0;
+  db->addr_free = 0;
+
+  return 0;
+}
+
+int
+nat64_db_free (nat64_db_t * db)
+{
+  clib_bihash_free_24_8 (&db->bib.in2out);
+  clib_bihash_free_24_8 (&db->bib.out2in);
+
+  clib_bihash_free_48_8 (&db->st.in2out);
+  clib_bihash_free_48_8 (&db->st.out2in);
+
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+  pool_free (db->bib._##n##_bib); \
+  pool_free (db->st._##n##_st);
+  foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+
+  pool_free (db->bib._unk_proto_bib);
+  pool_free (db->st._unk_proto_st);
+
+  return 0;
+}
+
+nat64_db_bib_entry_t *
+nat64_db_bib_entry_create (u32 thread_index, nat64_db_t * db,
+			   ip6_address_t * in_addr,
+			   ip4_address_t * out_addr, u16 in_port,
+			   u16 out_port, u32 fib_index, u8 proto,
+			   u8 is_static)
+{
+  nat64_db_bib_entry_t *bibe;
+  nat64_db_bib_entry_key_t bibe_key;
+  clib_bihash_kv_24_8_t kv;
+
+  if (db->bib.bib_entries_num >= db->bib.limit)
+    {
+      db->free_addr_port_cb (db, out_addr, out_port, proto);
+      //nat_ipfix_logging_max_bibs (thread_index, db->bib.limit);
+      return 0;
+    }
+
+  /* create pool entry */
+  switch (ip_proto_to_nat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      pool_get (db->bib._##n##_bib, bibe); \
+      kv.value = bibe - db->bib._##n##_bib; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      pool_get (db->bib._unk_proto_bib, bibe);
+      kv.value = bibe - db->bib._unk_proto_bib;
+      break;
+    }
+
+  db->bib.bib_entries_num++;
+
+  clib_memset (bibe, 0, sizeof (*bibe));
+  bibe->in_addr.as_u64[0] = in_addr->as_u64[0];
+  bibe->in_addr.as_u64[1] = in_addr->as_u64[1];
+  bibe->in_port = in_port;
+  bibe->out_addr.as_u32 = out_addr->as_u32;
+  bibe->out_port = out_port;
+  bibe->fib_index = fib_index;
+  bibe->proto = proto;
+  bibe->is_static = is_static;
+
+  /* create hash lookup */
+  bibe_key.addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  bibe_key.addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  bibe_key.fib_index = bibe->fib_index;
+  bibe_key.port = bibe->in_port;
+  bibe_key.proto = bibe->proto;
+  bibe_key.rsvd = 0;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.in2out, &kv, 1);
+
+  clib_memset (&bibe_key.addr, 0, sizeof (bibe_key.addr));
+  bibe_key.addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  bibe_key.fib_index = 0;
+  bibe_key.port = bibe->out_port;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.out2in, &kv, 1);
+
+  /*fib_table_t *fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+     nat_ipfix_logging_nat64_bib (thread_index, in_addr, out_addr, proto,
+     in_port, out_port, fib->ft_table_id, 1); */
+  return bibe;
+}
+
+void
+nat64_db_bib_entry_free (u32 thread_index, nat64_db_t * db,
+			 nat64_db_bib_entry_t * bibe)
+{
+  nat64_db_bib_entry_key_t bibe_key;
+  clib_bihash_kv_24_8_t kv;
+  nat64_db_bib_entry_t *bib;
+  u32 *ste_to_be_free = 0, *ste_index, bibe_index;
+  nat64_db_st_entry_t *st, *ste;
+
+  switch (ip_proto_to_nat_proto (bibe->proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      bib = db->bib._##n##_bib; \
+      st = db->st._##n##_st; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      bib = db->bib._unk_proto_bib;
+      st = db->st._unk_proto_st;
+      break;
+    }
+
+  db->bib.bib_entries_num--;
+
+  bibe_index = bibe - bib;
+
+  /* delete ST entries for static BIB entry */
+  if (bibe->is_static)
+    {
+      pool_foreach (ste, st, (
+			       {
+			       if (ste->bibe_index == bibe_index)
+			       vec_add1 (ste_to_be_free, ste - st);}
+		    ));
+      vec_foreach (ste_index, ste_to_be_free)
+	nat64_db_st_entry_free (thread_index, db,
+				pool_elt_at_index (st, ste_index[0]));
+      vec_free (ste_to_be_free);
+    }
+
+  /* delete hash lookup */
+  bibe_key.addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  bibe_key.addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  bibe_key.fib_index = bibe->fib_index;
+  bibe_key.port = bibe->in_port;
+  bibe_key.proto = bibe->proto;
+  bibe_key.rsvd = 0;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.in2out, &kv, 0);
+
+  clib_memset (&bibe_key.addr, 0, sizeof (bibe_key.addr));
+  bibe_key.addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  bibe_key.fib_index = 0;
+  bibe_key.port = bibe->out_port;
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+  clib_bihash_add_del_24_8 (&db->bib.out2in, &kv, 0);
+
+  if (!db->addr_free)
+    db->free_addr_port_cb (db, &bibe->out_addr, bibe->out_port, bibe->proto);
+
+  /*fib_table_t *fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+     nat_ipfix_logging_nat64_bib (thread_index, &bibe->in_addr, &bibe->out_addr,
+     bibe->proto, bibe->in_port, bibe->out_port,
+     fib->ft_table_id, 0); */
+
+  /* delete from pool */
+  pool_put (bib, bibe);
+}
+
+nat64_db_bib_entry_t *
+nat64_db_bib_entry_find (nat64_db_t * db, ip46_address_t * addr, u16 port,
+			 u8 proto, u32 fib_index, u8 is_ip6)
+{
+  nat64_db_bib_entry_t *bibe = 0;
+  nat64_db_bib_entry_key_t bibe_key;
+  clib_bihash_kv_24_8_t kv, value;
+  nat64_db_bib_entry_t *bib;
+
+  switch (ip_proto_to_nat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+
+  bibe_key.addr.as_u64[0] = addr->as_u64[0];
+  bibe_key.addr.as_u64[1] = addr->as_u64[1];
+  bibe_key.fib_index = fib_index;
+  bibe_key.port = port;
+  bibe_key.proto = proto;
+  bibe_key.rsvd = 0;
+
+  kv.key[0] = bibe_key.as_u64[0];
+  kv.key[1] = bibe_key.as_u64[1];
+  kv.key[2] = bibe_key.as_u64[2];
+
+  if (!clib_bihash_search_24_8
+      (is_ip6 ? &db->bib.in2out : &db->bib.out2in, &kv, &value))
+    bibe = pool_elt_at_index (bib, value.value);
+
+  return bibe;
+}
+
+void
+nat64_db_bib_walk (nat64_db_t * db, u8 proto,
+		   nat64_db_bib_walk_fn_t fn, void *ctx)
+{
+  nat64_db_bib_entry_t *bib, *bibe;
+
+  if (proto == 255)
+    {
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+      bib = db->bib._##n##_bib; \
+      pool_foreach (bibe, bib, ({ \
+        if (fn (bibe, ctx)) \
+          return; \
+      }));
+      foreach_nat_protocol
+    #undef _
+      bib = db->bib._unk_proto_bib;
+      pool_foreach (bibe, bib, ({
+        if (fn (bibe, ctx))
+          return;
+      }));
+    /* *INDENT-ON* */
+    }
+  else
+    {
+      switch (ip_proto_to_nat_proto (proto))
+	{
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+        case NAT_PROTOCOL_##N: \
+          bib = db->bib._##n##_bib; \
+          break;
+          foreach_nat_protocol
+    #undef _
+    /* *INDENT-ON* */
+	default:
+	  bib = db->bib._unk_proto_bib;
+	  break;
+	}
+
+      /* *INDENT-OFF* */
+      pool_foreach (bibe, bib,
+      ({
+        if (fn (bibe, ctx))
+          return;
+      }));
+      /* *INDENT-ON* */
+    }
+}
+
+nat64_db_bib_entry_t *
+nat64_db_bib_entry_by_index (nat64_db_t * db, u8 proto, u32 bibe_index)
+{
+  nat64_db_bib_entry_t *bib;
+
+  switch (ip_proto_to_nat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+
+  return pool_elt_at_index (bib, bibe_index);
+}
+
+void
+nat64_db_st_walk (nat64_db_t * db, u8 proto,
+		  nat64_db_st_walk_fn_t fn, void *ctx)
+{
+  nat64_db_st_entry_t *st, *ste;
+
+  if (proto == 255)
+    {
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+      st = db->st._##n##_st; \
+      pool_foreach (ste, st, ({ \
+        if (fn (ste, ctx)) \
+          return; \
+      }));
+      foreach_nat_protocol
+    #undef _
+      st = db->st._unk_proto_st;
+      pool_foreach (ste, st, ({
+        if (fn (ste, ctx))
+          return;
+      }));
+    /* *INDENT-ON* */
+    }
+  else
+    {
+      switch (ip_proto_to_nat_proto (proto))
+	{
+    /* *INDENT-OFF* */
+    #define _(N, i, n, s) \
+        case NAT_PROTOCOL_##N: \
+          st = db->st._##n##_st; \
+          break;
+          foreach_nat_protocol
+    #undef _
+    /* *INDENT-ON* */
+	default:
+	  st = db->st._unk_proto_st;
+	  break;
+	}
+
+      /* *INDENT-OFF* */
+      pool_foreach (ste, st,
+      ({
+        if (fn (ste, ctx))
+          return;
+      }));
+      /* *INDENT-ON* */
+    }
+}
+
+nat64_db_st_entry_t *
+nat64_db_st_entry_create (u32 thread_index, nat64_db_t * db,
+			  nat64_db_bib_entry_t * bibe,
+			  ip6_address_t * in_r_addr,
+			  ip4_address_t * out_r_addr, u16 r_port)
+{
+  nat64_db_st_entry_t *ste;
+  nat64_db_bib_entry_t *bib;
+  nat64_db_st_entry_key_t ste_key;
+  clib_bihash_kv_48_8_t kv;
+
+  if (db->st.st_entries_num >= db->st.limit)
+    {
+      //nat_ipfix_logging_max_sessions (thread_index, db->st.limit);
+      return 0;
+    }
+
+  /* create pool entry */
+  switch (ip_proto_to_nat_proto (bibe->proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      pool_get (db->st._##n##_st, ste); \
+      kv.value = ste - db->st._##n##_st; \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      pool_get (db->st._unk_proto_st, ste);
+      kv.value = ste - db->st._unk_proto_st;
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+
+  db->st.st_entries_num++;
+
+  clib_memset (ste, 0, sizeof (*ste));
+  ste->in_r_addr.as_u64[0] = in_r_addr->as_u64[0];
+  ste->in_r_addr.as_u64[1] = in_r_addr->as_u64[1];
+  ste->out_r_addr.as_u32 = out_r_addr->as_u32;
+  ste->r_port = r_port;
+  ste->bibe_index = bibe - bib;
+  ste->proto = bibe->proto;
+
+  /* increment session number for BIB entry */
+  bibe->ses_num++;
+
+  /* create hash lookup */
+  clib_memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  ste_key.l_addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  ste_key.r_addr.as_u64[0] = ste->in_r_addr.as_u64[0];
+  ste_key.r_addr.as_u64[1] = ste->in_r_addr.as_u64[1];
+  ste_key.fib_index = bibe->fib_index;
+  ste_key.l_port = bibe->in_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.in2out, &kv, 1);
+
+  clib_memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  ste_key.r_addr.ip4.as_u32 = ste->out_r_addr.as_u32;
+  ste_key.l_port = bibe->out_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.out2in, &kv, 1);
+
+  /*fib_table_t *fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+     nat_ipfix_logging_nat64_session (thread_index, &bibe->in_addr,
+     &bibe->out_addr, bibe->proto,
+     bibe->in_port, bibe->out_port,
+     &ste->in_r_addr, &ste->out_r_addr,
+     ste->r_port, ste->r_port, fib->ft_table_id,
+     1); */
+  nat_syslog_nat64_sadd (bibe->fib_index, &bibe->in_addr, bibe->in_port,
+			 &bibe->out_addr, bibe->out_port, &ste->out_r_addr,
+			 ste->r_port, bibe->proto);
+  return ste;
+}
+
+void
+nat64_db_st_entry_free (u32 thread_index,
+			nat64_db_t * db, nat64_db_st_entry_t * ste)
+{
+  nat64_db_st_entry_t *st;
+  nat64_db_bib_entry_t *bib, *bibe;
+  nat64_db_st_entry_key_t ste_key;
+  clib_bihash_kv_48_8_t kv;
+
+  switch (ip_proto_to_nat_proto (ste->proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      st = db->st._##n##_st; \
+      bib = db->bib._##n##_bib; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      st = db->st._unk_proto_st;
+      bib = db->bib._unk_proto_bib;
+      break;
+    }
+
+  bibe = pool_elt_at_index (bib, ste->bibe_index);
+
+  db->st.st_entries_num--;
+
+  /* delete hash lookup */
+  clib_memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.as_u64[0] = bibe->in_addr.as_u64[0];
+  ste_key.l_addr.as_u64[1] = bibe->in_addr.as_u64[1];
+  ste_key.r_addr.as_u64[0] = ste->in_r_addr.as_u64[0];
+  ste_key.r_addr.as_u64[1] = ste->in_r_addr.as_u64[1];
+  ste_key.fib_index = bibe->fib_index;
+  ste_key.l_port = bibe->in_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.in2out, &kv, 0);
+
+  clib_memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.ip4.as_u32 = bibe->out_addr.as_u32;
+  ste_key.r_addr.ip4.as_u32 = ste->out_r_addr.as_u32;
+  ste_key.l_port = bibe->out_port;
+  ste_key.r_port = ste->r_port;
+  ste_key.proto = ste->proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+  clib_bihash_add_del_48_8 (&db->st.out2in, &kv, 0);
+
+  /*fib_table_t *fib = fib_table_get (bibe->fib_index, FIB_PROTOCOL_IP6);
+     nat_ipfix_logging_nat64_session (thread_index, &bibe->in_addr,
+     &bibe->out_addr, bibe->proto,
+     bibe->in_port, bibe->out_port,
+     &ste->in_r_addr, &ste->out_r_addr,
+     ste->r_port, ste->r_port, fib->ft_table_id,
+     0); */
+  nat_syslog_nat64_sdel (bibe->fib_index, &bibe->in_addr, bibe->in_port,
+			 &bibe->out_addr, bibe->out_port, &ste->out_r_addr,
+			 ste->r_port, bibe->proto);
+
+  /* delete from pool */
+  pool_put (st, ste);
+
+  /* decrement session number for BIB entry */
+  bibe->ses_num--;
+
+  /* delete BIB entry if last session and dynamic */
+  if (!bibe->is_static && !bibe->ses_num)
+    nat64_db_bib_entry_free (thread_index, db, bibe);
+}
+
+nat64_db_st_entry_t *
+nat64_db_st_entry_find (nat64_db_t * db, ip46_address_t * l_addr,
+			ip46_address_t * r_addr, u16 l_port, u16 r_port,
+			u8 proto, u32 fib_index, u8 is_ip6)
+{
+  nat64_db_st_entry_t *ste = 0;
+  nat64_db_st_entry_t *st;
+  nat64_db_st_entry_key_t ste_key;
+  clib_bihash_kv_48_8_t kv, value;
+
+  switch (ip_proto_to_nat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      st = db->st._##n##_st; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      st = db->st._unk_proto_st;
+      break;
+    }
+
+  clib_memset (&ste_key, 0, sizeof (ste_key));
+  ste_key.l_addr.as_u64[0] = l_addr->as_u64[0];
+  ste_key.l_addr.as_u64[1] = l_addr->as_u64[1];
+  ste_key.r_addr.as_u64[0] = r_addr->as_u64[0];
+  ste_key.r_addr.as_u64[1] = r_addr->as_u64[1];
+  ste_key.fib_index = fib_index;
+  ste_key.l_port = l_port;
+  ste_key.r_port = r_port;
+  ste_key.proto = proto;
+  kv.key[0] = ste_key.as_u64[0];
+  kv.key[1] = ste_key.as_u64[1];
+  kv.key[2] = ste_key.as_u64[2];
+  kv.key[3] = ste_key.as_u64[3];
+  kv.key[4] = ste_key.as_u64[4];
+  kv.key[5] = ste_key.as_u64[5];
+
+  if (!clib_bihash_search_48_8
+      (is_ip6 ? &db->st.in2out : &db->st.out2in, &kv, &value))
+    ste = pool_elt_at_index (st, value.value);
+
+  return ste;
+}
+
+u32
+nat64_db_st_entry_get_index (nat64_db_t * db, nat64_db_st_entry_t * ste)
+{
+  nat64_db_st_entry_t *st;
+
+  switch (ip_proto_to_nat_proto (ste->proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      st = db->st._##n##_st; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      st = db->st._unk_proto_st;
+      return (u32) ~ 0;
+    }
+
+  return ste - st;
+}
+
+nat64_db_st_entry_t *
+nat64_db_st_entry_by_index (nat64_db_t * db, u8 proto, u32 ste_index)
+{
+  nat64_db_st_entry_t *st;
+
+  switch (ip_proto_to_nat_proto (proto))
+    {
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+    case NAT_PROTOCOL_##N: \
+      st = db->st._##n##_st; \
+      break;
+      foreach_nat_protocol
+#undef _
+/* *INDENT-ON* */
+    default:
+      st = db->st._unk_proto_st;
+      break;
+    }
+
+  return pool_elt_at_index (st, ste_index);
+}
+
+void
+nad64_db_st_free_expired (u32 thread_index, nat64_db_t * db, u32 now)
+{
+  u32 *ste_to_be_free = 0, *ste_index;
+  nat64_db_st_entry_t *st, *ste;
+
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+  st = db->st._##n##_st; \
+  pool_foreach (ste, st, ({\
+    if (i == NAT_PROTOCOL_TCP && !ste->tcp_state) \
+      continue; \
+    if (ste->expire < now) \
+      vec_add1 (ste_to_be_free, ste - st); \
+  })); \
+  vec_foreach (ste_index, ste_to_be_free) \
+    nat64_db_st_entry_free (thread_index, db, \
+                            pool_elt_at_index(st, ste_index[0])); \
+  vec_free (ste_to_be_free); \
+  ste_to_be_free = 0;
+  foreach_nat_protocol
+#undef _
+  st = db->st._unk_proto_st;
+  pool_foreach (ste, st, ({
+    if (ste->expire < now)
+      vec_add1 (ste_to_be_free, ste - st);
+  }));
+  vec_foreach (ste_index, ste_to_be_free)
+    nat64_db_st_entry_free (thread_index, db,
+                            pool_elt_at_index(st, ste_index[0]));
+  vec_free (ste_to_be_free);
+/* *INDENT-ON* */
+}
+
+void
+nat64_db_free_out_addr (u32 thread_index,
+			nat64_db_t * db, ip4_address_t * out_addr)
+{
+  u32 *ste_to_be_free = 0, *ste_index;
+  nat64_db_st_entry_t *st, *ste;
+  nat64_db_bib_entry_t *bibe;
+
+  db->addr_free = 1;
+/* *INDENT-OFF* */
+#define _(N, i, n, s) \
+  st = db->st._##n##_st; \
+  pool_foreach (ste, st, ({ \
+    bibe = pool_elt_at_index (db->bib._##n##_bib, ste->bibe_index); \
+    if (bibe->out_addr.as_u32 == out_addr->as_u32) \
+      vec_add1 (ste_to_be_free, ste - st); \
+  })); \
+  vec_foreach (ste_index, ste_to_be_free) \
+    nat64_db_st_entry_free (thread_index, db, \
+                            pool_elt_at_index(st, ste_index[0])); \
+  vec_free (ste_to_be_free); \
+  ste_to_be_free = 0;
+  foreach_nat_protocol
+#undef _
+  st = db->st._unk_proto_st;
+  pool_foreach (ste, st, ({
+    bibe = pool_elt_at_index (db->bib._unk_proto_bib, ste->bibe_index);
+    if (bibe->out_addr.as_u32 == out_addr->as_u32)
+      vec_add1 (ste_to_be_free, ste - st);
+  }));
+  vec_foreach (ste_index, ste_to_be_free)
+    nat64_db_st_entry_free (thread_index, db,
+                            pool_elt_at_index(st, ste_index[0]));
+  vec_free (ste_to_be_free);
+  db->addr_free = 0;
+/* *INDENT-ON* */
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */