Add support for 464XLAT NAT44 mode (VPP-1045)

Change-Id: I24e7a26972bbbfcea100292b212b29ae7a349335
Signed-off-by: Juraj Sloboda <jsloboda@cisco.com>

7 files changed, 166 insertions, 7 deletions

diff --git a/src/plugins/nat.am b/src/plugins/nat.am
index b6c369fe324..a0e0568a5a1 100644
--- a/src/plugins/nat.am
+++ b/src/plugins/nat.am
@@ -23,6 +23,7 @@ nat_plugin_la_SOURCES = nat/nat.c		\
         nat/nat_ipfix_logging.c	        	\
         nat/nat_det.c               		\
         nat/nat_reass.c             		\
+        nat/nat_dpo.c                       \
         nat/nat64.c                  		\
         nat/nat64_cli.c              		\
         nat/nat64_in2out.c           		\
diff --git a/src/plugins/nat/in2out.c b/src/plugins/nat/in2out.c
index 517011eec06..b0dbbc8fa11 100755
--- a/src/plugins/nat/in2out.c
+++ b/src/plugins/nat/in2out.c
@@ -179,6 +179,9 @@ snat_not_translate_fast (snat_main_t * sm, vlib_node_runtime_t *node,
                          u32 sw_if_index0, ip4_header_t * ip0, u32 proto0,
                          u32 rx_fib_index0)
 {
+  if (sm->out2in_dpo)
+    return 0;
+
   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
   fib_prefix_t pfx = {
     .fp_proto = FIB_PROTOCOL_IP4,
diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c
index e9b2c2c07ba..721ad16d3dc 100644
--- a/src/plugins/nat/nat.c
+++ b/src/plugins/nat/nat.c
@@ -20,6 +20,7 @@
 #include <vnet/ip/ip4.h>
 #include <vnet/plugin/plugin.h>
 #include <nat/nat.h>
+#include <nat/nat_dpo.h>
 #include <nat/nat_ipfix_logging.h>
 #include <nat/nat_det.h>
 #include <nat/nat64.h>
@@ -567,7 +568,7 @@ void snat_add_address (snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
   /* Add external address to FIB */
   pool_foreach (i, sm->interfaces,
   ({
-    if (nat_interface_is_inside(i))
+    if (nat_interface_is_inside(i) || sm->out2in_dpo)
       continue;
 
     snat_add_del_addr_to_fib(addr, 32, i->sw_if_index, 1);
@@ -575,7 +576,7 @@ void snat_add_address (snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
   }));
   pool_foreach (i, sm->output_feature_interfaces,
   ({
-    if (nat_interface_is_inside(i))
+    if (nat_interface_is_inside(i) || sm->out2in_dpo)
       continue;
 
     snat_add_del_addr_to_fib(addr, 32, i->sw_if_index, 1);
@@ -951,7 +952,7 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
   /* Add/delete external address to FIB */
   pool_foreach (interface, sm->interfaces,
   ({
-    if (nat_interface_is_inside(interface))
+    if (nat_interface_is_inside(interface) || sm->out2in_dpo)
       continue;
 
     snat_add_del_addr_to_fib(&e_addr, 32, interface->sw_if_index, is_add);
@@ -959,7 +960,7 @@ int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
   }));
   pool_foreach (interface, sm->output_feature_interfaces,
   ({
-    if (nat_interface_is_inside(interface))
+    if (nat_interface_is_inside(interface) || sm->out2in_dpo)
       continue;
 
     snat_add_del_addr_to_fib(&e_addr, 32, interface->sw_if_index, is_add);
@@ -1324,7 +1325,7 @@ snat_del_address (snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
   /* Delete external address from FIB */
   pool_foreach (interface, sm->interfaces,
   ({
-    if (nat_interface_is_inside(interface))
+    if (nat_interface_is_inside(interface) || sm->out2in_dpo)
       continue;
 
     snat_add_del_addr_to_fib(&addr, 32, interface->sw_if_index, 0);
@@ -1332,7 +1333,7 @@ snat_del_address (snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
   }));
   pool_foreach (interface, sm->output_feature_interfaces,
   ({
-    if (nat_interface_is_inside(interface))
+    if (nat_interface_is_inside(interface) || sm->out2in_dpo)
       continue;
 
     snat_add_del_addr_to_fib(&addr, 32, interface->sw_if_index, 0);
@@ -1351,6 +1352,9 @@ int snat_interface_add_del (u32 sw_if_index, u8 is_inside, int is_del)
   snat_static_mapping_t * m;
   snat_det_map_t * dm;
 
+  if (sm->out2in_dpo && !is_inside)
+    return VNET_API_ERROR_UNSUPPORTED;
+
   if (sm->static_mapping_only && !(sm->static_mapping_connection_tracking))
     feature_name = is_inside ?  "nat44-in2out-fast" : "nat44-out2in-fast";
   else
@@ -1452,7 +1456,7 @@ set_flags:
 
   /* Add/delete external addresses to FIB */
 fib:
-  if (is_inside)
+  if (is_inside && !sm->out2in_dpo)
     {
       vnet_feature_enable_disable ("ip4-local", "nat44-hairpinning",
                                    sw_if_index, !is_del, 0, 0);
@@ -1680,6 +1684,8 @@ static clib_error_t * snat_init (vlib_main_t * vm)
 
   vec_add1 (im->add_del_interface_address_callbacks, cb4);
 
+  nat_dpo_module_init ();
+
   /* Init IPFIX logging */
   snat_ipfix_logging_init(vm);
 
@@ -1988,6 +1994,29 @@ exhausted:
   return 1;
 }
 
+void
+nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add)
+{
+  dpo_id_t dpo_v4 = DPO_INVALID;
+  fib_prefix_t pfx = {
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_len = 32,
+    .fp_addr.ip4.as_u32 = addr.as_u32,
+  };
+
+  if (is_add)
+    {
+      nat_dpo_create (DPO_PROTO_IP4, 0, &dpo_v4);
+      fib_table_entry_special_dpo_add (0, &pfx, FIB_SOURCE_PLUGIN_HI,
+                                       FIB_ENTRY_FLAG_EXCLUSIVE, &dpo_v4);
+      dpo_reset (&dpo_v4);
+    }
+  else
+    {
+      fib_table_entry_special_remove (0, &pfx, FIB_SOURCE_PLUGIN_HI);
+    }
+}
+
 static clib_error_t *
 add_address_command_fn (vlib_main_t * vm,
                         unformat_input_t * input,
@@ -2074,6 +2103,9 @@ add_address_command_fn (vlib_main_t * vm,
           break;
         }
 
+      if (sm->out2in_dpo)
+        nat44_add_del_address_dpo (this_addr, is_add);
+
       increment_v4_address (&this_addr);
     }
 
@@ -2866,6 +2898,7 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
   snat_main_per_thread_data_t *tsm;
 
   sm->deterministic = 0;
+  sm->out2in_dpo = 0;
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
@@ -2906,6 +2939,8 @@ snat_config (vlib_main_t * vm, unformat_input_t * input)
       else if (unformat (input, "nat64 st hash memory %d",
                          &nat64_st_memory_size))
         ;
+      else if (unformat (input, "out2in dpo"))
+        sm->out2in_dpo = 1;
       else
 	return clib_error_return (0, "unknown input '%U'",
 				  format_unformat_error, input);
diff --git a/src/plugins/nat/nat.h b/src/plugins/nat/nat.h
index 1e8e3ca0403..614668d8421 100644
--- a/src/plugins/nat/nat.h
+++ b/src/plugins/nat/nat.h
@@ -357,6 +357,7 @@ typedef struct snat_main_s {
   u8 static_mapping_only;
   u8 static_mapping_connection_tracking;
   u8 deterministic;
+  u8 out2in_dpo;
   u32 translation_buckets;
   u32 translation_memory_size;
   u32 max_translations;
@@ -539,6 +540,7 @@ void snat_add_address(snat_main_t *sm, ip4_address_t *addr, u32 vrf_id,
                       u8 twice_nat);
 int snat_del_address(snat_main_t *sm, ip4_address_t addr, u8 delete_sm,
                      u8 twice_nat);
+void nat44_add_del_address_dpo (ip4_address_t addr, u8 is_add);
 int snat_add_static_mapping(ip4_address_t l_addr, ip4_address_t e_addr,
                             u16 l_port, u16 e_port, u32 vrf_id, int addr_only,
                             u32 sw_if_index, snat_protocol_t proto, int is_add,
diff --git a/src/plugins/nat/nat_api.c b/src/plugins/nat/nat_api.c
index 2397663270a..d0efb001843 100644
--- a/src/plugins/nat/nat_api.c
+++ b/src/plugins/nat/nat_api.c
@@ -442,6 +442,9 @@ static void
       if (rv)
 	goto send_reply;
 
+      if (sm->out2in_dpo)
+	nat44_add_del_address_dpo (this_addr, mp->is_add);
+
       increment_v4_address (&this_addr);
     }
 
diff --git a/src/plugins/nat/nat_dpo.c b/src/plugins/nat/nat_dpo.c
new file mode 100644
index 00000000000..46ccda8845e
--- /dev/null
+++ b/src/plugins/nat/nat_dpo.c
@@ -0,0 +1,79 @@
+/*
+ * 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.
+ */
+
+#include <vnet/ip/ip.h>
+#include <nat/nat_dpo.h>
+
+dpo_type_t nat_dpo_type;
+
+void
+nat_dpo_create (dpo_proto_t dproto, u32 aftr_index, dpo_id_t * dpo)
+{
+  dpo_set (dpo, nat_dpo_type, dproto, aftr_index);
+}
+
+u8 *
+format_nat_dpo (u8 * s, va_list * args)
+{
+  index_t index = va_arg (*args, index_t);
+  CLIB_UNUSED (u32 indent) = va_arg (*args, u32);
+
+  return (format (s, "NAT44 out2in: AFTR:%d", index));
+}
+
+static void
+nat_dpo_lock (dpo_id_t * dpo)
+{
+}
+
+static void
+nat_dpo_unlock (dpo_id_t * dpo)
+{
+}
+
+const static dpo_vft_t nat_dpo_vft = {
+  .dv_lock = nat_dpo_lock,
+  .dv_unlock = nat_dpo_unlock,
+  .dv_format = format_nat_dpo,
+};
+
+const static char *const nat_ip4_nodes[] = {
+  "nat44-out2in",
+  NULL,
+};
+
+const static char *const nat_ip6_nodes[] = {
+  NULL,
+};
+
+const static char *const *const nat_nodes[DPO_PROTO_NUM] = {
+  [DPO_PROTO_IP4] = nat_ip4_nodes,
+  [DPO_PROTO_IP6] = nat_ip6_nodes,
+  [DPO_PROTO_MPLS] = NULL,
+};
+
+void
+nat_dpo_module_init (void)
+{
+  nat_dpo_type = dpo_register_new_type (&nat_dpo_vft, nat_nodes);
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/nat/nat_dpo.h b/src/plugins/nat/nat_dpo.h
new file mode 100644
index 00000000000..e85b3e824f3
--- /dev/null
+++ b/src/plugins/nat/nat_dpo.h
@@ -0,0 +1,36 @@
+/*
+ * 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.
+ */
+
+#ifndef __included_nat_dpo_h__
+#define __included_nat_dpo_h__
+
+#include <vnet/vnet.h>
+#include <vnet/dpo/dpo.h>
+
+void nat_dpo_create (dpo_proto_t dproto, u32 aftr_index, dpo_id_t * dpo);
+
+u8 *format_nat_dpo (u8 * s, va_list * args);
+
+void nat_dpo_module_init (void);
+
+#endif /* __included_nat_dpo_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */