NAT: Rename snat plugin to nat (VPP-955)

Change-Id: I30a7e3da7a4efc6038a91e27b48045d4b07e2764
Signed-off-by: Matus Fabian <matfabia@cisco.com>

1 files changed, 158 insertions, 0 deletions

diff --git a/src/plugins/nat/nat_det.c b/src/plugins/nat/nat_det.c
new file mode 100644
index 00000000000..3af6698c09a
--- /dev/null
+++ b/src/plugins/nat/nat_det.c
@@ -0,0 +1,158 @@
+/*
+ * snat_det.c - deterministic NAT
+ *
+ * Copyright (c) 2017 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.
+ */
+/**
+ * @file
+ * @brief deterministic NAT
+ */
+
+#include <nat/nat_det.h>
+
+
+/**
+ * @brief Add/delete deterministic NAT mapping.
+ *
+ * Create bijective mapping of inside address to outside address and port range
+ * pairs, with the purpose of enabling deterministic NAT to reduce logging in
+ * CGN deployments.
+ *
+ * @param sm       SNAT main.
+ * @param in_addr  Inside network address.
+ * @param in_plen  Inside network prefix length.
+ * @param out_addr Outside network address.
+ * @param out_plen Outside network prefix length.
+ * @param is_add   If 0 delete, otherwise add.
+ */
+int
+snat_det_add_map (snat_main_t * sm, ip4_address_t * in_addr, u8 in_plen,
+		  ip4_address_t * out_addr, u8 out_plen, int is_add)
+{
+  snat_det_map_t *det_map;
+  static snat_det_session_t empty_snat_det_session = { 0 };
+  snat_interface_t *i;
+  ip4_address_t in_cmp, out_cmp;
+  u8 found = 0;
+
+  in_cmp.as_u32 = in_addr->as_u32 & ip4_main.fib_masks[in_plen];
+  out_cmp.as_u32 = out_addr->as_u32 & ip4_main.fib_masks[out_plen];
+  vec_foreach (det_map, sm->det_maps)
+  {
+    /* Checking for overlapping addresses to be added here */
+    if (det_map->in_addr.as_u32 == in_cmp.as_u32 &&
+	det_map->in_plen == in_plen &&
+	det_map->out_addr.as_u32 == out_cmp.as_u32 &&
+	det_map->out_plen == out_plen)
+      {
+	found = 1;
+	break;
+      }
+  }
+
+  /* If found, don't add again */
+  if (found && is_add)
+    return VNET_API_ERROR_VALUE_EXIST;
+
+  /* If not found, don't delete */
+  if (!found && !is_add)
+    return VNET_API_ERROR_NO_SUCH_ENTRY;
+
+  if (is_add)
+    {
+      pool_get (sm->det_maps, det_map);
+      memset (det_map, 0, sizeof (*det_map));
+      det_map->in_addr.as_u32 = in_cmp.as_u32;
+      det_map->in_plen = in_plen;
+      det_map->out_addr.as_u32 = out_cmp.as_u32;
+      det_map->out_plen = out_plen;
+      det_map->sharing_ratio = (1 << (32 - in_plen)) / (1 << (32 - out_plen));
+      det_map->ports_per_host = (65535 - 1023) / det_map->sharing_ratio;
+
+      vec_validate_init_empty (det_map->sessions,
+			       SNAT_DET_SES_PER_USER * (1 << (32 - in_plen)) -
+			       1, empty_snat_det_session);
+    }
+  else
+    {
+      vec_free (det_map->sessions);
+      vec_del1 (sm->det_maps, det_map - sm->det_maps);
+    }
+
+  /* Add/del external address range to FIB */
+  /* *INDENT-OFF* */
+  pool_foreach (i, sm->interfaces,
+  ({
+    if (i->is_inside)
+      continue;
+
+    snat_add_del_addr_to_fib(out_addr, out_plen, i->sw_if_index, is_add);
+    break;
+  }));
+  /* *INDENT-ON* */
+  return 0;
+}
+
+/**
+ * @brief The 'nat-det-expire-walk' process's main loop.
+ *
+ * Check expire time for active sessions.
+ */
+static uword
+snat_det_expire_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
+			 vlib_frame_t * f)
+{
+  snat_main_t *sm = &snat_main;
+  snat_det_map_t *dm;
+  snat_det_session_t *ses;
+
+  while (sm->deterministic)
+    {
+      vlib_process_wait_for_event_or_clock (vm, 10.0);
+      vlib_process_get_events (vm, NULL);
+      u32 now = (u32) vlib_time_now (vm);
+      /* *INDENT-OFF* */
+      pool_foreach (dm, sm->det_maps,
+      ({
+        vec_foreach(ses, dm->sessions)
+          {
+            /* Delete if session expired */
+            if (ses->in_port && (ses->expire < now))
+              snat_det_ses_close (dm, ses);
+          }
+      }));
+      /* *INDENT-ON* */
+    }
+
+  return 0;
+}
+
+static vlib_node_registration_t snat_det_expire_walk_node;
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (snat_det_expire_walk_node, static) = {
+    .function = snat_det_expire_walk_fn,
+    .type = VLIB_NODE_TYPE_PROCESS,
+    .name =
+    "nat-det-expire-walk",
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */