lib/prefix.h

   1 /*
   2  * Prefix structure.
   3  * Copyright (C) 1998 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #ifndef _ZEBRA_PREFIX_H
  24 #define _ZEBRA_PREFIX_H
  25
  26 #include "sockunion.h"
  27
  28 /*
  29  * A struct prefix contains an address family, a prefix length, and an
  30  * address.  This can represent either a 'network prefix' as defined
  31  * by CIDR, where the 'host bits' of the prefix are 0
  32  * (e.g. AF_INET:10.0.0.0/8), or an address and netmask
  33  * (e.g. AF_INET:10.0.0.9/8), such as might be configured on an
  34  * interface.
  35  */
  36
  37 /* IPv4 and IPv6 unified prefix structure. */
  38 struct prefix
  39 {
  40   u_char family;
  41   u_char prefixlen;
  42   union
  43   {
  44     u_char prefix;
  45     struct in_addr prefix4;
  46 #ifdef HAVE_IPV6
  47     struct in6_addr prefix6;
  48 #endif /* HAVE_IPV6 */
  49     struct
  50     {
  51       struct in_addr id;
  52       struct in_addr adv_router;
  53     } lp;
  54     u_char val[8];
  55   } u __attribute__ ((aligned (8)));
  56 };
  57
  58 /* IPv4 prefix structure. */
  59 struct prefix_ipv4
  60 {
  61   u_char family;
  62   u_char prefixlen;
  63   struct in_addr prefix __attribute__ ((aligned (8)));
  64 };
  65
  66 /* IPv6 prefix structure. */
  67 #ifdef HAVE_IPV6
  68 struct prefix_ipv6
  69 {
  70   u_char family;
  71   u_char prefixlen;
  72   struct in6_addr prefix __attribute__ ((aligned (8)));
  73 };
  74 #endif /* HAVE_IPV6 */
  75
  76 struct prefix_ls
  77 {
  78   u_char family;
  79   u_char prefixlen;
  80   struct in_addr id __attribute__ ((aligned (8)));
  81   struct in_addr adv_router;
  82 };
  83
  84 /* Prefix for routing distinguisher. */
  85 struct prefix_rd
  86 {
  87   u_char family;
  88   u_char prefixlen;
  89   u_char val[8] __attribute__ ((aligned (8)));
  90 };
  91
  92 #ifndef INET_ADDRSTRLEN
  93 #define INET_ADDRSTRLEN 16
  94 #endif /* INET_ADDRSTRLEN */
  95
  96 #ifndef INET6_ADDRSTRLEN
  97 #define INET6_ADDRSTRLEN 46
  98 #endif /* INET6_ADDRSTRLEN */
  99
 100 #ifndef INET6_BUFSIZ
 101 #define INET6_BUFSIZ 51
 102 #endif /* INET6_BUFSIZ */
 103
 104 /* Max bit/byte length of IPv4 address. */
 105 #define IPV4_MAX_BYTELEN    4
 106 #define IPV4_MAX_BITLEN    32
 107 #define IPV4_MAX_PREFIXLEN 32
 108 #define IPV4_ADDR_CMP(D,S)   memcmp ((D), (S), IPV4_MAX_BYTELEN)
 109 #define IPV4_ADDR_SAME(D,S)  (memcmp ((D), (S), IPV4_MAX_BYTELEN) == 0)
 110 #define IPV4_ADDR_COPY(D,S)  memcpy ((D), (S), IPV4_MAX_BYTELEN)
 111
 112 #define IPV4_NET0(a)    ((((u_int32_t) (a)) & 0xff000000) == 0x00000000)
 113 #define IPV4_NET127(a)  ((((u_int32_t) (a)) & 0xff000000) == 0x7f000000)
 114 #define IPV4_LINKLOCAL(a) ((((u_int32_t) (a)) & 0xffff0000) == 0xa9fe0000)
 115
 116 /* Max bit/byte length of IPv6 address. */
 117 #define IPV6_MAX_BYTELEN    16
 118 #define IPV6_MAX_BITLEN    128
 119 #define IPV6_MAX_PREFIXLEN 128
 120 #define IPV6_ADDR_CMP(D,S)   memcmp ((D), (S), IPV6_MAX_BYTELEN)
 121 #define IPV6_ADDR_SAME(D,S)  (memcmp ((D), (S), IPV6_MAX_BYTELEN) == 0)
 122 #define IPV6_ADDR_COPY(D,S)  memcpy ((D), (S), IPV6_MAX_BYTELEN)
 123
 124 /* Count prefix size from mask length */
 125 #define PSIZE(a) (((a) + 7) / (8))
 126
 127 /* Prefix's family member. */
 128 #define PREFIX_FAMILY(p)  ((p)->family)
 129
 130 /* Check bit of the prefix. */
 131 static inline unsigned int
 132 prefix_bit (const u_char *prefix, const u_char prefixlen)
 133 {
 134   unsigned int offset = prefixlen / 8;
 135   unsigned int shift  = 7 - (prefixlen % 8);
 136
 137   return (prefix[offset] >> shift) & 1;
 138 }
 139
 140 static inline unsigned int
 141 prefix6_bit (const struct in6_addr *prefix, const u_char prefixlen)
 142 {
 143   return prefix_bit((const u_char *) &prefix->s6_addr, prefixlen);
 144 }
 145
 146 /* Prototypes. */
 147 extern int afi2family (int);
 148 extern int family2afi (int);
 149
 150 extern struct prefix *prefix_new (void);
 151 extern void prefix_free (struct prefix *);
 152 extern const char *prefix_family_str (const struct prefix *);
 153 extern int prefix_blen (const struct prefix *);
 154 extern int str2prefix (const char *, struct prefix *);
 155 extern int prefix2str (const struct prefix *, char *, int);
 156 extern int prefix_match (const struct prefix *, const struct prefix *);
 157 extern int prefix_same (const struct prefix *, const struct prefix *);
 158 extern int prefix_cmp (const struct prefix *, const struct prefix *);
 159 extern void prefix_copy (struct prefix *dest, const struct prefix *src);
 160 extern void apply_mask (struct prefix *);
 161
 162 extern struct prefix *sockunion2prefix (const union sockunion *dest,
 163                                         const union sockunion *mask);
 164 extern struct prefix *sockunion2hostprefix (const union sockunion *);
 165
 166 extern struct prefix_ipv4 *prefix_ipv4_new (void);
 167 extern void prefix_ipv4_free (struct prefix_ipv4 *);
 168 extern int str2prefix_ipv4 (const char *, struct prefix_ipv4 *);
 169 extern void apply_mask_ipv4 (struct prefix_ipv4 *);
 170
 171 #define PREFIX_COPY_IPV4(DST, SRC)      \
 172         *((struct prefix_ipv4 *)(DST)) = *((const struct prefix_ipv4 *)(SRC));
 173
 174 extern int prefix_ipv4_any (const struct prefix_ipv4 *);
 175 extern void apply_classful_mask_ipv4 (struct prefix_ipv4 *);
 176
 177 extern u_char ip_masklen (struct in_addr);
 178 extern void masklen2ip (int, struct in_addr *);
 179 /* returns the network portion of the host address */
 180 extern in_addr_t ipv4_network_addr (in_addr_t hostaddr, int masklen);
 181 /* given the address of a host on a network and the network mask length,
 182  * calculate the broadcast address for that network;
 183  * special treatment for /31: returns the address of the other host
 184  * on the network by flipping the host bit */
 185 extern in_addr_t ipv4_broadcast_addr (in_addr_t hostaddr, int masklen);
 186
 187 extern int netmask_str2prefix_str (const char *, const char *, char *);
 188
 189 #ifdef HAVE_IPV6
 190 extern struct prefix_ipv6 *prefix_ipv6_new (void);
 191 extern void prefix_ipv6_free (struct prefix_ipv6 *);
 192 extern int str2prefix_ipv6 (const char *, struct prefix_ipv6 *);
 193 extern void apply_mask_ipv6 (struct prefix_ipv6 *);
 194
 195 #define PREFIX_COPY_IPV6(DST, SRC)      \
 196         *((struct prefix_ipv6 *)(DST)) = *((const struct prefix_ipv6 *)(SRC));
 197
 198 extern int ip6_masklen (struct in6_addr);
 199 extern void masklen2ip6 (int, struct in6_addr *);
 200
 201 extern void str2in6_addr (const char *, struct in6_addr *);
 202 extern const char *inet6_ntoa (struct in6_addr);
 203
 204 #endif /* HAVE_IPV6 */
 205
 206 extern int all_digit (const char *);
 207
 208 #endif /* _ZEBRA_PREFIX_H */