Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2020 Cisco and/or its affiliates.
       3             :  * Licensed under the Apache License, Version 2.0 (the "License");
       4             :  * you may not use this file except in compliance with the License.
       5             :  * You may obtain a copy of the License at:
       6             :  *
       7             :  *     http://www.apache.org/licenses/LICENSE-2.0
       8             :  *
       9             :  * Unless required by applicable law or agreed to in writing, software
      10             :  * distributed under the License is distributed on an "AS IS" BASIS,
      11             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             :  * See the License for the specific language governing permissions and
      13             :  * limitations under the License.
      14             :  */
      15             : /**
      16             :  * @file
      17             :  * @brief NAT port/address allocation lib
      18             :  */
      19             : #ifndef included_nat_lib_h__
      20             : #define included_nat_lib_h__
      21             : 
      22             : #include <vlibapi/api.h>
      23             : 
      24             : typedef struct
      25             : {
      26             :   u16 identifier;
      27             :   u16 sequence;
      28             : } nat_icmp_echo_header_t;
      29             : 
      30             : typedef struct
      31             : {
      32             :   u16 src_port, dst_port;
      33             : } nat_tcp_udp_header_t;
      34             : 
      35             : /* NAT API Configuration flags */
      36             : #define foreach_nat_config_flag \
      37             :   _(0x01, IS_TWICE_NAT)         \
      38             :   _(0x02, IS_SELF_TWICE_NAT)    \
      39             :   _(0x04, IS_OUT2IN_ONLY)       \
      40             :   _(0x08, IS_ADDR_ONLY)         \
      41             :   _(0x10, IS_OUTSIDE)           \
      42             :   _(0x20, IS_INSIDE)            \
      43             :   _(0x40, IS_STATIC)            \
      44             :   _(0x80, IS_EXT_HOST_VALID)
      45             : 
      46             : typedef enum nat_config_flags_t_
      47             : {
      48             : #define _(n,f) NAT_API_##f = n,
      49             :   foreach_nat_config_flag
      50             : #undef _
      51             : } nat_config_flags_t;
      52             : 
      53             : #define foreach_nat_counter _ (tcp) _ (udp) _ (icmp) _ (other) _ (drops)
      54             : 
      55             : #define foreach_nat_error                      \
      56             :   _ (VALUE_EXIST, -1, "Value already exists")  \
      57             :   _ (NO_SUCH_ENTRY, -2, "No such entry")       \
      58             :   _ (UNKNOWN_PROTOCOL, -3, "Unknown protocol") \
      59             :   _ (OUT_OF_TRANSLATIONS, -4, "Out of translations")
      60             : 
      61             : typedef enum
      62             : {
      63             : #define _(N, i, s) NAT_ERROR_##N = i,
      64             :   foreach_nat_error
      65             : #undef _
      66             : } nat_error_t;
      67             : 
      68             : /* default protocol timeouts */
      69             : #define NAT_UDP_TIMEOUT 300
      70             : #define NAT_TCP_TRANSITORY_TIMEOUT 240
      71             : #define NAT_TCP_ESTABLISHED_TIMEOUT 7440
      72             : #define NAT_ICMP_TIMEOUT 60
      73             : 
      74             : typedef struct
      75             : {
      76             :   struct
      77             :   {
      78             :     u32 established;
      79             :     u32 transitory;
      80             :   } tcp;
      81             : 
      82             :   u32 udp;
      83             :   u32 icmp;
      84             : 
      85             : } nat_timeouts_t;
      86             : 
      87             : static_always_inline void
      88         727 : nat_reset_timeouts (nat_timeouts_t * timeouts)
      89             : {
      90         727 :   timeouts->udp = NAT_UDP_TIMEOUT;
      91         727 :   timeouts->tcp.established = NAT_TCP_ESTABLISHED_TIMEOUT;
      92         727 :   timeouts->tcp.transitory = NAT_TCP_TRANSITORY_TIMEOUT;
      93         727 :   timeouts->icmp = NAT_ICMP_TIMEOUT;
      94         727 : }
      95             : 
      96             : static_always_inline u32
      97         211 : nat_calc_bihash_buckets (u32 n_elts)
      98             : {
      99         211 :   n_elts = n_elts / 2.5;
     100         211 :   u64 lower_pow2 = 1;
     101        2308 :   while (lower_pow2 * 2 < n_elts)
     102             :     {
     103        2097 :       lower_pow2 = 2 * lower_pow2;
     104             :     }
     105         211 :   u64 upper_pow2 = 2 * lower_pow2;
     106         211 :   if ((upper_pow2 - n_elts) < (n_elts - lower_pow2))
     107             :     {
     108         188 :       if (upper_pow2 <= UINT32_MAX)
     109             :         {
     110         188 :           return upper_pow2;
     111             :         }
     112             :     }
     113          23 :   return lower_pow2;
     114             : }
     115             : 
     116             : #endif /* included_nat_lib_h__ */
     117             : /*
     118             :  * fd.io coding-style-patch-verification: ON
     119             :  *
     120             :  * Local Variables:
     121             :  * eval: (c-set-style "gnu")
     122             :  * End:
     123             :  */