Line data    Source code

       1             : /*
       2             :  * det44.h - deterministic NAT definitions
       3             :  *
       4             :  * Copyright (c) 2020 Cisco and/or its affiliates.
       5             :  * Licensed under the Apache License, Version 2.0 (the "License");
       6             :  * you may not use this file except in compliance with the License.
       7             :  * You may obtain a copy of the License at:
       8             :  *
       9             :  *     http://www.apache.org/licenses/LICENSE-2.0
      10             :  *
      11             :  * Unless required by applicable law or agreed to in writing, software
      12             :  * distributed under the License is distributed on an "AS IS" BASIS,
      13             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      14             :  * See the License for the specific language governing permissions and
      15             :  * limitations under the License.
      16             :  */
      17             : 
      18             : /**
      19             :  * @file
      20             :  * @brief Deterministic NAT (CGN) inlines
      21             :  */
      22             : 
      23             : #ifndef __included_det44_inlines_h__
      24             : #define __included_det44_inlines_h__
      25             : 
      26             : static_always_inline int
      27           2 : det44_is_interface_addr (vlib_node_runtime_t * node,
      28             :                          u32 sw_if_index0, u32 ip4_addr)
      29             : {
      30           2 :   det44_runtime_t *rt = (det44_runtime_t *) node->runtime_data;
      31           2 :   det44_main_t *dm = &det44_main;
      32             :   ip4_address_t *first_int_addr;
      33             : 
      34           2 :   if (PREDICT_FALSE (rt->cached_sw_if_index != sw_if_index0))
      35             :     {
      36           1 :       first_int_addr = ip4_interface_first_address (dm->ip4_main,
      37             :                                                     sw_if_index0, 0);
      38           1 :       rt->cached_sw_if_index = sw_if_index0;
      39           1 :       if (first_int_addr)
      40           1 :         rt->cached_ip4_address = first_int_addr->as_u32;
      41             :       else
      42           0 :         rt->cached_ip4_address = 0;
      43             :     }
      44           2 :   if (PREDICT_FALSE (rt->cached_ip4_address == ip4_addr))
      45           0 :     return 0;
      46           2 :   return 1;
      47             : }
      48             : 
      49             : /**
      50             :  * @brief Check if packet should be translated
      51             :  *
      52             :  * Packets aimed at outside interface and external address with active session
      53             :  * should be translated.
      54             :  *
      55             :  * @param node          NAT runtime data
      56             :  * @param sw_if_index0  index of the inside interface
      57             :  * @param ip0           IPv4 header
      58             :  * @param proto0        NAT protocol
      59             :  * @param rx_fib_index0 RX FIB index
      60             :  *
      61             :  * @returns 0 if packet should be translated otherwise 1
      62             :  */
      63             : static_always_inline int
      64           2 : det44_translate (vlib_node_runtime_t * node, u32 sw_if_index0,
      65             :                  ip4_header_t * ip0, u32 proto0, u32 rx_fib_index0)
      66             : {
      67           2 :   det44_main_t *dm = &det44_main;
      68           2 :   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
      69             :   det44_fib_t *outside_fib;
      70           2 :   fib_prefix_t pfx = {
      71             :     .fp_proto = FIB_PROTOCOL_IP4,
      72             :     .fp_len = 32,
      73             :     .fp_addr = {
      74           2 :                 .ip4.as_u32 = ip0->dst_address.as_u32,
      75             :                 }
      76             :     ,
      77             :   };
      78             : 
      79             :   /* Don't NAT packet aimed at the interface address */
      80           2 :   if (PREDICT_FALSE (!det44_is_interface_addr (node, sw_if_index0,
      81             :                                                ip0->dst_address.as_u32)))
      82             :     {
      83           0 :       return 1;
      84             :     }
      85             : 
      86             :   /* find out if there is outside feature enabled for this destination */
      87           2 :   fei = fib_table_lookup (rx_fib_index0, &pfx);
      88           2 :   if (FIB_NODE_INDEX_INVALID != fei)
      89             :     {
      90           2 :       u32 sw_if_index = fib_entry_get_resolving_interface (fei);
      91           2 :       if (sw_if_index == ~0)
      92             :         {
      93             :           // TODO: go over use cases
      94             :           /* *INDENT-OFF* */
      95           0 :           vec_foreach (outside_fib, dm->outside_fibs)
      96             :             {
      97           0 :               fei = fib_table_lookup (outside_fib->fib_index, &pfx);
      98           0 :               if (FIB_NODE_INDEX_INVALID != fei)
      99             :                 {
     100           0 :                   sw_if_index = fib_entry_get_resolving_interface (fei);
     101           0 :                   if (sw_if_index != ~0)
     102           0 :                     break;
     103             :                 }
     104             :             }
     105             :           /* *INDENT-ON* */
     106             :         }
     107           2 :       if (sw_if_index != ~0)
     108             :         {
     109             :           det44_interface_t *i;
     110             :           /* *INDENT-OFF* */
     111           4 :           pool_foreach (i, dm->interfaces)  {
     112             :             /* NAT packet aimed at outside interface */
     113           4 :             if ((det44_interface_is_outside (i)) && (sw_if_index == i->sw_if_index))
     114           2 :               return 0;
     115             :           }
     116             :           /* *INDENT-ON* */
     117             :         }
     118             :     }
     119           0 :   return 1;
     120             : }
     121             : 
     122             : #endif /* __included_det44_inlines_h__ */
     123             : 
     124             : /*
     125             :  * fd.io coding-style-patch-verification: ON
     126             :  *
     127             :  * Local Variables:
     128             :  * eval: (c-set-style "gnu")
     129             :  * End:
     130             :  */