nat: move deterministic nat to det44 sub feature

Type: refactor

Change-Id: I0bb203102a0e13dd7448e2125925ab356bbd7937
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 608 insertions, 0 deletions

diff --git a/src/plugins/nat/det44/det44.c b/src/plugins/nat/det44/det44.c
new file mode 100644
index 00000000000..886092cea50
--- /dev/null
+++ b/src/plugins/nat/det44/det44.c
@@ -0,0 +1,608 @@
+/*
+ * det44.c - deterministic NAT
+ *
+ * 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.
+ */
+/**
+ * @file
+ * @brief deterministic NAT (CGN)
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ip/ip4.h>
+#include <vpp/app/version.h>
+#include <vnet/plugin/plugin.h>
+
+#include <nat/det44/det44.h>
+
+det44_main_t det44_main;
+
+/* *INDENT-OFF* */
+VNET_FEATURE_INIT (ip4_det44_in2out, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "det44-in2out",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+                               "ip4-sv-reassembly-feature"),
+};
+VNET_FEATURE_INIT (ip4_det44_out2in, static) = {
+  .arc_name = "ip4-unicast",
+  .node_name = "det44-out2in",
+  .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa",
+                               "ip4-sv-reassembly-feature",
+                               "ip4-dhcp-client-detect"),
+};
+VLIB_PLUGIN_REGISTER () = {
+    .version = VPP_BUILD_VER,
+    .description = "Deterministic NAT (CGN)",
+};
+/* *INDENT-ON* */
+
+void
+det44_add_del_addr_to_fib (ip4_address_t * addr, u8 p_len, u32 sw_if_index,
+			   int is_add)
+{
+  det44_main_t *dm = &det44_main;
+  fib_prefix_t prefix = {
+    .fp_len = p_len,
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_addr = {
+		.ip4.as_u32 = addr->as_u32,
+		},
+  };
+  u32 fib_index = ip4_fib_table_get_index_for_sw_if_index (sw_if_index);
+
+  if (is_add)
+    {
+      fib_table_entry_update_one_path (fib_index,
+				       &prefix,
+				       dm->fib_src_low,
+				       (FIB_ENTRY_FLAG_CONNECTED |
+					FIB_ENTRY_FLAG_LOCAL |
+					FIB_ENTRY_FLAG_EXCLUSIVE),
+				       DPO_PROTO_IP4,
+				       NULL,
+				       sw_if_index,
+				       ~0, 1, NULL, FIB_ROUTE_PATH_FLAG_NONE);
+    }
+  else
+    {
+      fib_table_entry_delete (fib_index, &prefix, dm->fib_src_low);
+    }
+}
+
+/**
+ * @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 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 (ip4_address_t * in_addr, u8 in_plen,
+		  ip4_address_t * out_addr, u8 out_plen, int is_add)
+{
+  static snat_det_session_t empty_snat_det_session = { 0 };
+  det44_main_t *dm = &det44_main;
+  ip4_address_t in_cmp, out_cmp;
+  det44_interface_t *i;
+  snat_det_map_t *mp;
+  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 (mp, dm->det_maps)
+  {
+    /* Checking for overlapping addresses to be added here */
+    if (mp->in_addr.as_u32 == in_cmp.as_u32 &&
+	mp->in_plen == in_plen &&
+	mp->out_addr.as_u32 == out_cmp.as_u32 && mp->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 (dm->det_maps, mp);
+      clib_memset (mp, 0, sizeof (*mp));
+      mp->in_addr.as_u32 = in_cmp.as_u32;
+      mp->in_plen = in_plen;
+      mp->out_addr.as_u32 = out_cmp.as_u32;
+      mp->out_plen = out_plen;
+      mp->sharing_ratio = (1 << (32 - in_plen)) / (1 << (32 - out_plen));
+      mp->ports_per_host = (65535 - 1023) / mp->sharing_ratio;
+
+      vec_validate_init_empty (mp->sessions,
+			       DET44_SES_PER_USER * (1 << (32 - in_plen)) -
+			       1, empty_snat_det_session);
+    }
+  else
+    {
+      vec_free (mp->sessions);
+      vec_del1 (dm->det_maps, mp - dm->det_maps);
+    }
+
+  /* Add/del external address range to FIB */
+  /* *INDENT-OFF* */
+  pool_foreach (i, dm->interfaces, ({
+    if (det44_interface_is_inside(i))
+      continue;
+    det44_add_del_addr_to_fib(out_addr, out_plen, i->sw_if_index, is_add);
+    goto out;
+  }));
+  /* *INDENT-ON* */
+out:
+  return 0;
+}
+
+int
+det44_set_timeouts (nat_timeouts_t * timeouts)
+{
+  det44_main_t *dm = &det44_main;
+  if (timeouts->udp)
+    dm->timeouts.udp = timeouts->udp;
+  if (timeouts->tcp.established)
+    dm->timeouts.tcp.established = timeouts->tcp.established;
+  if (timeouts->tcp.transitory)
+    dm->timeouts.tcp.transitory = timeouts->tcp.transitory;
+  if (timeouts->icmp)
+    dm->timeouts.icmp = timeouts->icmp;
+  return 0;
+}
+
+nat_timeouts_t
+det44_get_timeouts ()
+{
+  det44_main_t *dm = &det44_main;
+  return dm->timeouts;
+}
+
+void
+det44_reset_timeouts ()
+{
+  det44_main_t *dm = &det44_main;
+  dm->timeouts.udp = 300;
+  dm->timeouts.tcp.established = 7440;
+  dm->timeouts.tcp.transitory = 240;
+  dm->timeouts.icmp = 60;
+}
+
+int
+det44_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
+{
+  det44_main_t *dm = &det44_main;
+  det44_interface_t *tmp, *i = 0;
+  const char *feature_name;
+  int rv;
+
+  // TODO: if plugin is not enabled do not register nodes on interfaces
+  // rather make a structure and when enable call is used
+  // then register nodes
+
+  /* *INDENT-OFF* */
+  pool_foreach (tmp, dm->interfaces, ({
+    if (tmp->sw_if_index == sw_if_index)
+      {
+        i = tmp;
+        goto out;
+      }
+  }));
+  /* *INDENT-ON* */
+out:
+
+  feature_name = is_inside ? "det44-in2out" : "det44-out2in";
+
+  if (is_del)
+    {
+      if (!i)
+	{
+	  det44_log_err ("det44 is not enabled on this interface");
+	  return VNET_API_ERROR_INVALID_VALUE;
+	}
+
+      rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 0);
+      if (rv)
+	return rv;
+
+      rv = vnet_feature_enable_disable ("ip4-unicast", feature_name,
+					sw_if_index, 1, 0, 0);
+      if (rv)
+	return rv;
+
+      pool_put (dm->interfaces, i);
+    }
+  else
+    {
+      if (i)
+	{
+	  det44_log_err ("det44 is already enabled on this interface");
+	  return VNET_API_ERROR_INVALID_VALUE;
+	}
+
+      rv = ip4_sv_reass_enable_disable_with_refcnt (sw_if_index, 1);
+      if (rv)
+	return rv;
+
+      rv = vnet_feature_enable_disable ("ip4-unicast", feature_name,
+					sw_if_index, 1, 0, 0);
+      if (rv)
+	return rv;
+
+      pool_get (dm->interfaces, i);
+      clib_memset (i, 0, sizeof (*i));
+
+      i->sw_if_index = sw_if_index;
+
+      if (is_inside)
+	i->flags |= DET44_INTERFACE_FLAG_IS_INSIDE;
+      else
+	i->flags |= DET44_INTERFACE_FLAG_IS_OUTSIDE;
+    }
+
+  if (!is_inside)
+    {
+      u32 fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
+							   sw_if_index);
+      // add/del outside interface fib to registry
+      u8 found = 0;
+      det44_fib_t *outside_fib;
+      /* *INDENT-OFF* */
+      vec_foreach (outside_fib, dm->outside_fibs)
+        {
+          if (outside_fib->fib_index == fib_index)
+            {
+              if (!is_del)
+                {
+                  outside_fib->refcount++;
+                }
+              else
+                {
+                  outside_fib->refcount--;
+                  if (!outside_fib->refcount)
+                    {
+                      vec_del1 (dm->outside_fibs,
+                                outside_fib - dm->outside_fibs);
+                    }
+                }
+              found = 1;
+              break;
+            }
+        }
+      /* *INDENT-ON* */
+      if (!is_del && !found)
+	{
+	  vec_add2 (dm->outside_fibs, outside_fib, 1);
+	  outside_fib->fib_index = fib_index;
+	  outside_fib->refcount = 1;
+	}
+      // add/del outside address to FIB
+      snat_det_map_t *mp;
+      /* *INDENT-OFF* */
+      pool_foreach (mp, dm->det_maps, ({
+        det44_add_del_addr_to_fib(&mp->out_addr,
+                                  mp->out_plen, sw_if_index, !is_del);
+      }));
+      /* *INDENT-ON* */
+    }
+  return 0;
+}
+
+/**
+ * @brief The 'det44-expire-walk' process's main loop.
+ *
+ * Check expire time for active sessions.
+ */
+static uword
+det44_expire_walk_fn (vlib_main_t * vm, vlib_node_runtime_t * rt,
+		      vlib_frame_t * f)
+{
+  det44_main_t *dm = &det44_main;
+  snat_det_session_t *ses;
+  snat_det_map_t *mp;
+
+  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 (mp, dm->det_maps, ({
+    vec_foreach(ses, mp->sessions)
+      {
+        /* Delete if session expired */
+        if (ses->in_port && (ses->expire < now))
+          snat_det_ses_close (mp, ses);
+      }
+  }));
+  /* *INDENT-ON* */
+  return 0;
+}
+
+void
+det44_create_expire_walk_process ()
+{
+  det44_main_t *dm = &det44_main;
+
+  if (dm->expire_walk_node_index)
+    return;
+
+  dm->expire_walk_node_index = vlib_process_create (vlib_get_main (),
+						    "det44-expire-walk",
+						    det44_expire_walk_fn,
+						    16 /* stack_bytes */ );
+}
+
+int
+det44_plugin_enable (det44_config_t c)
+{
+  det44_main_t *dm = &det44_main;
+
+  if (plugin_enabled () == 1)
+    {
+      det44_log_err ("plugin already enabled!");
+      return 1;
+    }
+
+  det44_log_err ("inside %u, outside %u", c.inside_vrf_id, c.outside_vrf_id);
+
+  dm->outside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
+							     c.outside_vrf_id,
+							     dm->fib_src_hi);
+  dm->inside_fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4,
+							    c.inside_vrf_id,
+							    dm->fib_src_hi);
+
+  det44_create_expire_walk_process ();
+  dm->mss_clamping = 0;
+  dm->config = c;
+  dm->enabled = 1;
+  return 0;
+}
+
+int
+det44_plugin_disable ()
+{
+  det44_main_t *dm = &det44_main;
+  det44_interface_t *i, *interfaces;
+  snat_det_map_t *mp;
+  int rv = 0;
+
+  if (plugin_enabled () == 0)
+    {
+      det44_log_err ("plugin already disabled!");
+      return 1;
+    }
+
+  // DET44 cleanup (order dependent)
+  // 1) remove interfaces (det44_interface_add_del) removes map ranges from fib
+  // 2) free sessions
+  // 3) free maps
+
+  interfaces = vec_dup (dm->interfaces);
+  vec_foreach (i, interfaces)
+  {
+    vnet_main_t *vnm = vnet_get_main ();
+
+    if (i->flags & DET44_INTERFACE_FLAG_IS_INSIDE)
+      {
+	rv = det44_interface_add_del (i->sw_if_index, i->flags, 1);
+	if (rv)
+	  {
+	    det44_log_err ("inside interface %U del failed",
+			   unformat_vnet_sw_interface, vnm, i->sw_if_index);
+	  }
+      }
+
+    if (i->flags & DET44_INTERFACE_FLAG_IS_OUTSIDE)
+      {
+	rv = det44_interface_add_del (i->sw_if_index, i->flags, 1);
+	if (rv)
+	  {
+	    det44_log_err ("outside interface %U del failed",
+			   unformat_vnet_sw_interface, vnm, i->sw_if_index);
+	  }
+
+      }
+  }
+  vec_free (interfaces);
+
+  /* *INDENT-OFF* */
+  pool_foreach (mp, dm->det_maps,
+  ({
+    vec_free (mp->sessions);
+  }));
+  /* *INDENT-ON* */
+
+  det44_reset_timeouts ();
+  dm->enabled = 0;
+
+  pool_free (dm->interfaces);
+  pool_free (dm->det_maps);
+
+  return rv;
+}
+
+static void
+det44_update_outside_fib (ip4_main_t * im,
+			  uword opaque,
+			  u32 sw_if_index, u32 new_fib_index,
+			  u32 old_fib_index)
+{
+  det44_main_t *dm = &det44_main;
+
+  det44_fib_t *outside_fib;
+  det44_interface_t *i;
+
+  u8 is_add = 1;
+  u8 match = 0;
+
+  if (plugin_enabled () == 0)
+    return;
+
+  if (new_fib_index == old_fib_index)
+    return;
+
+  if (!vec_len (dm->outside_fibs))
+    return;
+
+  /* *INDENT-OFF* */
+  pool_foreach (i, dm->interfaces,
+    ({
+      if (i->sw_if_index == sw_if_index)
+        {
+          if (!(det44_interface_is_outside (i)))
+	    return;
+          match = 1;
+        }
+    }));
+  /* *INDENT-ON* */
+
+  if (!match)
+    return;
+
+  vec_foreach (outside_fib, dm->outside_fibs)
+  {
+    if (outside_fib->fib_index == old_fib_index)
+      {
+	outside_fib->refcount--;
+	if (!outside_fib->refcount)
+	  vec_del1 (dm->outside_fibs, outside_fib - dm->outside_fibs);
+	break;
+      }
+  }
+
+  vec_foreach (outside_fib, dm->outside_fibs)
+  {
+    if (outside_fib->fib_index == new_fib_index)
+      {
+	outside_fib->refcount++;
+	is_add = 0;
+	break;
+      }
+  }
+
+  if (is_add)
+    {
+      vec_add2 (dm->outside_fibs, outside_fib, 1);
+      outside_fib->refcount = 1;
+      outside_fib->fib_index = new_fib_index;
+    }
+}
+
+static clib_error_t *
+det44_init (vlib_main_t * vm)
+{
+  det44_main_t *dm = &det44_main;
+  ip4_table_bind_callback_t cb;
+  vlib_node_t *node;
+
+  clib_memset (dm, 0, sizeof (*dm));
+
+  dm->ip4_main = &ip4_main;
+  dm->log_class = vlib_log_register_class ("det44", 0);
+
+  node = vlib_get_node_by_name (vm, (u8 *) "det44-in2out");
+  dm->in2out_node_index = node->index;
+  node = vlib_get_node_by_name (vm, (u8 *) "det44-out2in");
+  dm->out2in_node_index = node->index;
+
+  dm->fib_src_hi = fib_source_allocate ("det44-hi",
+					FIB_SOURCE_PRIORITY_HI,
+					FIB_SOURCE_BH_SIMPLE);
+  dm->fib_src_low = fib_source_allocate ("det44-low",
+					 FIB_SOURCE_PRIORITY_LOW,
+					 FIB_SOURCE_BH_SIMPLE);
+
+  cb.function = det44_update_outside_fib;
+  cb.function_opaque = 0;
+  vec_add1 (dm->ip4_main->table_bind_callbacks, cb);
+
+  det44_reset_timeouts ();
+  return det44_api_hookup (vm);
+}
+
+VLIB_INIT_FUNCTION (det44_init);
+
+u8 *
+format_det44_session_state (u8 * s, va_list * args)
+{
+  u32 i = va_arg (*args, u32);
+  u8 *t = 0;
+
+  switch (i)
+    {
+#define _(v, N, str) case DET44_SESSION_##N: t = (u8 *) str; break;
+      foreach_det44_session_state
+#undef _
+    default:
+      t = format (t, "unknown");
+    }
+  s = format (s, "%s", t);
+  return s;
+}
+
+u8 *
+format_det_map_ses (u8 * s, va_list * args)
+{
+  snat_det_map_t *det_map = va_arg (*args, snat_det_map_t *);
+  ip4_address_t in_addr, out_addr;
+  u32 in_offset, out_offset;
+  snat_det_session_t *ses = va_arg (*args, snat_det_session_t *);
+  u32 *i = va_arg (*args, u32 *);
+
+  u32 user_index = *i / DET44_SES_PER_USER;
+  in_addr.as_u32 =
+    clib_host_to_net_u32 (clib_net_to_host_u32 (det_map->in_addr.as_u32) +
+			  user_index);
+  in_offset =
+    clib_net_to_host_u32 (in_addr.as_u32) -
+    clib_net_to_host_u32 (det_map->in_addr.as_u32);
+  out_offset = in_offset / det_map->sharing_ratio;
+  out_addr.as_u32 =
+    clib_host_to_net_u32 (clib_net_to_host_u32 (det_map->out_addr.as_u32) +
+			  out_offset);
+  s =
+    format (s,
+	    "in %U:%d out %U:%d external host %U:%d state: %U expire: %d\n",
+	    format_ip4_address, &in_addr, clib_net_to_host_u16 (ses->in_port),
+	    format_ip4_address, &out_addr,
+	    clib_net_to_host_u16 (ses->out.out_port), format_ip4_address,
+	    &ses->out.ext_host_addr,
+	    clib_net_to_host_u16 (ses->out.ext_host_port),
+	    format_det44_session_state, ses->state, ses->expire);
+
+  return s;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */