src/plugins/nat/det44/det44_inlines.h

   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 det44_is_interface_addr (vlib_node_runtime_t * node,
  28                          u32 sw_if_index0, u32 ip4_addr)
  29 {
  30   det44_runtime_t *rt = (det44_runtime_t *) node->runtime_data;
  31   det44_main_t *dm = &det44_main;
  32   ip4_address_t *first_int_addr;
  33
  34   if (PREDICT_FALSE (rt->cached_sw_if_index != sw_if_index0))
  35     {
  36       first_int_addr = ip4_interface_first_address (dm->ip4_main,
  37                                                     sw_if_index0, 0);
  38       rt->cached_sw_if_index = sw_if_index0;
  39       if (first_int_addr)
  40         rt->cached_ip4_address = first_int_addr->as_u32;
  41       else
  42         rt->cached_ip4_address = 0;
  43     }
  44   if (PREDICT_FALSE (rt->cached_ip4_address == ip4_addr))
  45     return 0;
  46   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 det44_translate (vlib_node_runtime_t * node, u32 sw_if_index0,
  65                  ip4_header_t * ip0, u32 proto0, u32 rx_fib_index0)
  66 {
  67   det44_main_t *dm = &det44_main;
  68   fib_node_index_t fei = FIB_NODE_INDEX_INVALID;
  69   det44_fib_t *outside_fib;
  70   fib_prefix_t pfx = {
  71     .fp_proto = FIB_PROTOCOL_IP4,
  72     .fp_len = 32,
  73     .fp_addr = {
  74                 .ip4.as_u32 = ip0->dst_address.as_u32,
  75                 }
  76     ,
  77   };
  78
  79   /* Don't NAT packet aimed at the interface address */
  80   if (PREDICT_FALSE (!det44_is_interface_addr (node, sw_if_index0,
  81                                                ip0->dst_address.as_u32)))
  82     {
  83       return 1;
  84     }
  85
  86   /* find out if there is outside feature enabled for this destination */
  87   fei = fib_table_lookup (rx_fib_index0, &pfx);
  88   if (FIB_NODE_INDEX_INVALID != fei)
  89     {
  90       u32 sw_if_index = fib_entry_get_resolving_interface (fei);
  91       if (sw_if_index == ~0)
  92         {
  93           // TODO: go over use cases
  94           /* *INDENT-OFF* */
  95           vec_foreach (outside_fib, dm->outside_fibs)
  96             {
  97               fei = fib_table_lookup (outside_fib->fib_index, &pfx);
  98               if (FIB_NODE_INDEX_INVALID != fei)
  99                 {
 100                   sw_if_index = fib_entry_get_resolving_interface (fei);
 101                   if (sw_if_index != ~0)
 102                     break;
 103                 }
 104             }
 105           /* *INDENT-ON* */
 106         }
 107       if (sw_if_index != ~0)
 108         {
 109           det44_interface_t *i;
 110           /* *INDENT-OFF* */
 111           pool_foreach (i, dm->interfaces, ({
 112             /* NAT packet aimed at outside interface */
 113             if ((det44_interface_is_outside (i)) && (sw_if_index == i->sw_if_index))
 114               return 0;
 115           }));
 116           /* *INDENT-ON* */
 117         }
 118     }
 119   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  */