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     uintptr_t ptr;
  56   } u __attribute__ ((aligned (8)));
  57 };
  58
  59 /* IPv4 prefix structure. */
  60 struct prefix_ipv4
  61 {
  62   u_char family;
  63   u_char prefixlen;
  64   struct in_addr prefix __attribute__ ((aligned (8)));
  65 };
  66
  67 /* IPv6 prefix structure. */
  68 #ifdef HAVE_IPV6
  69 struct prefix_ipv6
  70 {
  71   u_char family;
  72   u_char prefixlen;
  73   struct in6_addr prefix __attribute__ ((aligned (8)));
  74 };
  75 #endif /* HAVE_IPV6 */
  76
  77 struct prefix_ls
  78 {
  79   u_char family;
  80   u_char prefixlen;
  81   struct in_addr id __attribute__ ((aligned (8)));
  82   struct in_addr adv_router;
  83 };
  84
  85 /* Prefix for routing distinguisher. */
  86 struct prefix_rd
  87 {
  88   u_char family;
  89   u_char prefixlen;
  90   u_char val[8] __attribute__ ((aligned (8)));
  91 };
  92
  93 /* Prefix for a generic pointer */
  94 struct prefix_ptr
  95 {
  96   u_char family;
  97   u_char prefixlen;
  98   uintptr_t prefix __attribute__ ((aligned (8)));
  99 };
 100
 101 /* helper to get type safety/avoid casts on calls
 102  * (w/o this, functions accepting all prefix types need casts on the caller
 103  * side, which strips type safety since the cast will accept any pointer
 104  * type.)
 105  */
 106 union prefix46ptr
 107 {
 108   struct prefix *p;
 109   struct prefix_ipv4 *p4;
 110   struct prefix_ipv6 *p6;
 111 } __attribute__ ((transparent_union));
 112
 113 union prefix46constptr
 114 {
 115   const struct prefix *p;
 116   const struct prefix_ipv4 *p4;
 117   const struct prefix_ipv6 *p6;
 118 } __attribute__ ((transparent_union));
 119
 120 #ifndef INET_ADDRSTRLEN
 121 #define INET_ADDRSTRLEN 16
 122 #endif /* INET_ADDRSTRLEN */
 123
 124 #ifndef INET6_ADDRSTRLEN
 125 #define INET6_ADDRSTRLEN 46
 126 #endif /* INET6_ADDRSTRLEN */
 127
 128 #ifndef INET6_BUFSIZ
 129 #define INET6_BUFSIZ 51
 130 #endif /* INET6_BUFSIZ */
 131
 132 /* Max bit/byte length of IPv4 address. */
 133 #define IPV4_MAX_BYTELEN    4
 134 #define IPV4_MAX_BITLEN    32
 135 #define IPV4_MAX_PREFIXLEN 32
 136 #define IPV4_ADDR_CMP(D,S)   memcmp ((D), (S), IPV4_MAX_BYTELEN)
 137 #define IPV4_ADDR_SAME(D,S)  (memcmp ((D), (S), IPV4_MAX_BYTELEN) == 0)
 138 #define IPV4_ADDR_COPY(D,S)  memcpy ((D), (S), IPV4_MAX_BYTELEN)
 139
 140 #define IPV4_NET0(a)    ((((u_int32_t) (a)) & 0xff000000) == 0x00000000)
 141 #define IPV4_NET127(a)  ((((u_int32_t) (a)) & 0xff000000) == 0x7f000000)
 142 #define IPV4_LINKLOCAL(a) ((((u_int32_t) (a)) & 0xffff0000) == 0xa9fe0000)
 143 #define IPV4_CLASS_DE(a)  ((((u_int32_t) (a)) & 0xe0000000) == 0xe0000000)
 144
 145 /* Max bit/byte length of IPv6 address. */
 146 #define IPV6_MAX_BYTELEN    16
 147 #define IPV6_MAX_BITLEN    128
 148 #define IPV6_MAX_PREFIXLEN 128
 149 #define IPV6_ADDR_CMP(D,S)   memcmp ((D), (S), IPV6_MAX_BYTELEN)
 150 #define IPV6_ADDR_SAME(D,S)  (memcmp ((D), (S), IPV6_MAX_BYTELEN) == 0)
 151 #define IPV6_ADDR_COPY(D,S)  memcpy ((D), (S), IPV6_MAX_BYTELEN)
 152
 153 /* Count prefix size from mask length */
 154 #define PSIZE(a) (((a) + 7) / (8))
 155
 156 /* Prefix's family member. */
 157 #define PREFIX_FAMILY(p)  ((p)->family)
 158
 159 /* glibc defines s6_addr32 to __in6_u.__u6_addr32 if __USE_{MISC || GNU} */
 160 #ifndef s6_addr32
 161 #if defined(SUNOS_5)
 162 /* Some SunOS define s6_addr32 only to kernel */
 163 #define s6_addr32 _S6_un._S6_u32
 164 #else
 165 #define s6_addr32 __u6_addr.__u6_addr32
 166 #endif /* SUNOS_5 */
 167 #endif /*s6_addr32*/
 168
 169 /* Prototypes. */
 170 extern int afi2family (afi_t);
 171 extern afi_t family2afi (int);
 172
 173 /* Check bit of the prefix. */
 174 extern unsigned int prefix_bit (const u_char *prefix, const u_char prefixlen);
 175 extern unsigned int prefix6_bit (const struct in6_addr *prefix, const u_char prefixlen);
 176
 177 extern struct prefix *prefix_new (void);
 178 extern void prefix_free (struct prefix *);
 179 extern const char *prefix_family_str (const struct prefix *);
 180 extern int prefix_blen (const struct prefix *);
 181 extern int str2prefix (const char *, struct prefix *);
 182 extern int prefix2str (const struct prefix *, char *, int);
 183 extern int prefix_match (const struct prefix *, const struct prefix *);
 184 extern int prefix_same (const struct prefix *, const struct prefix *);
 185 extern int prefix_cmp (const struct prefix *, const struct prefix *);
 186 extern int prefix_common_bits (const struct prefix *, const struct prefix *);
 187 extern void prefix_copy (struct prefix *dest, const struct prefix *src);
 188 extern void apply_mask (struct prefix *);
 189
 190 extern struct prefix *sockunion2prefix (const union sockunion *dest,
 191                                         const union sockunion *mask);
 192 extern struct prefix *sockunion2hostprefix (const union sockunion *);
 193 extern void prefix2sockunion (const struct prefix *, union sockunion *);
 194
 195 extern struct prefix_ipv4 *prefix_ipv4_new (void);
 196 extern void prefix_ipv4_free (struct prefix_ipv4 *);
 197 extern int str2prefix_ipv4 (const char *, struct prefix_ipv4 *);
 198 extern void apply_mask_ipv4 (struct prefix_ipv4 *);
 199
 200 #define PREFIX_COPY_IPV4(DST, SRC)      \
 201         *((struct prefix_ipv4 *)(DST)) = *((const struct prefix_ipv4 *)(SRC));
 202
 203 extern int prefix_ipv4_any (const struct prefix_ipv4 *);
 204 extern void apply_classful_mask_ipv4 (struct prefix_ipv4 *);
 205
 206 extern u_char ip_masklen (struct in_addr);
 207 extern void masklen2ip (const int, struct in_addr *);
 208 /* returns the network portion of the host address */
 209 extern in_addr_t ipv4_network_addr (in_addr_t hostaddr, int masklen);
 210 /* given the address of a host on a network and the network mask length,
 211  * calculate the broadcast address for that network;
 212  * special treatment for /31: returns the address of the other host
 213  * on the network by flipping the host bit */
 214 extern in_addr_t ipv4_broadcast_addr (in_addr_t hostaddr, int masklen);
 215
 216 extern int netmask_str2prefix_str (const char *, const char *, char *);
 217
 218 #ifdef HAVE_IPV6
 219 extern struct prefix_ipv6 *prefix_ipv6_new (void);
 220 extern void prefix_ipv6_free (struct prefix_ipv6 *);
 221 extern int str2prefix_ipv6 (const char *, struct prefix_ipv6 *);
 222 extern void apply_mask_ipv6 (struct prefix_ipv6 *);
 223
 224 #define PREFIX_COPY_IPV6(DST, SRC)      \
 225         *((struct prefix_ipv6 *)(DST)) = *((const struct prefix_ipv6 *)(SRC));
 226
 227 extern int ip6_masklen (struct in6_addr);
 228 extern void masklen2ip6 (const int, struct in6_addr *);
 229
 230 extern void str2in6_addr (const char *, struct in6_addr *);
 231 extern const char *inet6_ntoa (struct in6_addr);
 232
 233 static inline int ipv6_martian (struct in6_addr *addr)
 234 {
 235   struct in6_addr localhost_addr;
 236
 237   inet_pton (AF_INET6, "::1", &localhost_addr);
 238
 239   if (IPV6_ADDR_SAME(&localhost_addr, addr))
 240     return 1;
 241
 242   return 0;
 243 }
 244
 245 #endif /* HAVE_IPV6 */
 246
 247 extern int all_digit (const char *);
 248
 249 /* NOTE: This routine expects the address argument in network byte order. */
 250 static inline int ipv4_martian (struct in_addr *addr)
 251 {
 252   in_addr_t ip = ntohl(addr->s_addr);
 253
 254   if (IPV4_NET0(ip) || IPV4_NET127(ip) || IPV4_CLASS_DE(ip)) {
 255     return 1;
 256   }
 257   return 0;
 258 }
 259
 260 static inline int
 261 is_default_prefix (struct prefix *p)
 262 {
 263   if (!p)
 264     return 0;
 265
 266   if (((p->family == AF_INET) && (p->u.prefix4.s_addr == INADDR_ANY))
 267       || ((p->family == AF_INET6) &&
 268           !memcmp(&p->u.prefix6, &in6addr_any, sizeof (struct in6_addr))))
 269     return 1;
 270
 271   return 0;
 272 }
 273
 274 #endif /* _ZEBRA_PREFIX_H */