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 #ifdef SUNOS_5
  27 # include <sys/ethernet.h>
  28 #else
  29 # ifdef GNU_LINUX
  30 #  include <net/ethernet.h>
  31 # else
  32 #  include <netinet/if_ether.h>
  33 # endif
  34 #endif
  35 #include "sockunion.h"
  36
  37 #ifndef ETHER_ADDR_LEN
  38 #define ETHER_ADDR_LEN  ETHERADDRL
  39 #endif
  40
  41 /*
  42  * there isn't a portable ethernet address type. We define our
  43  * own to simplify internal handling
  44  */
  45 struct ethaddr {
  46     u_char octet[ETHER_ADDR_LEN];
  47 } __packed;
  48
  49
  50 /*
  51  * A struct prefix contains an address family, a prefix length, and an
  52  * address.  This can represent either a 'network prefix' as defined
  53  * by CIDR, where the 'host bits' of the prefix are 0
  54  * (e.g. AF_INET:10.0.0.0/8), or an address and netmask
  55  * (e.g. AF_INET:10.0.0.9/8), such as might be configured on an
  56  * interface.
  57  */
  58
  59 /* different OSes use different names */
  60 #if defined(AF_PACKET)
  61 #define AF_ETHERNET AF_PACKET
  62 #else
  63 #if defined(AF_LINK)
  64 #define AF_ETHERNET AF_LINK
  65 #endif
  66 #endif
  67
  68 /* IPv4 and IPv6 unified prefix structure. */
  69 struct prefix
  70 {
  71   u_char family;
  72   u_char prefixlen;
  73   union
  74   {
  75     u_char prefix;
  76     struct in_addr prefix4;
  77     struct in6_addr prefix6;
  78     struct
  79     {
  80       struct in_addr id;
  81       struct in_addr adv_router;
  82     } lp;
  83     struct ethaddr prefix_eth;  /* AF_ETHERNET */
  84     u_char val[8];
  85     uintptr_t ptr;
  86   } u __attribute__ ((aligned (8)));
  87 };
  88
  89 /* IPv4 prefix structure. */
  90 struct prefix_ipv4
  91 {
  92   u_char family;
  93   u_char prefixlen;
  94   struct in_addr prefix __attribute__ ((aligned (8)));
  95 };
  96
  97 /* IPv6 prefix structure. */
  98 struct prefix_ipv6
  99 {
 100   u_char family;
 101   u_char prefixlen;
 102   struct in6_addr prefix __attribute__ ((aligned (8)));
 103 };
 104
 105 struct prefix_ls
 106 {
 107   u_char family;
 108   u_char prefixlen;
 109   struct in_addr id __attribute__ ((aligned (8)));
 110   struct in_addr adv_router;
 111 };
 112
 113 /* Prefix for routing distinguisher. */
 114 struct prefix_rd
 115 {
 116   u_char family;
 117   u_char prefixlen;
 118   u_char val[8] __attribute__ ((aligned (8)));
 119 };
 120
 121 /* Prefix for ethernet. */
 122 struct prefix_eth
 123 {
 124   u_char family;
 125   u_char prefixlen;
 126   struct ethaddr eth_addr __attribute__ ((aligned (8))); /* AF_ETHERNET */
 127 };
 128
 129 /* Prefix for a generic pointer */
 130 struct prefix_ptr
 131 {
 132   u_char family;
 133   u_char prefixlen;
 134   uintptr_t prefix __attribute__ ((aligned (8)));
 135 };
 136
 137 /* helper to get type safety/avoid casts on calls
 138  * (w/o this, functions accepting all prefix types need casts on the caller
 139  * side, which strips type safety since the cast will accept any pointer
 140  * type.)
 141  */
 142 union prefix46ptr
 143 {
 144   struct prefix *p;
 145   struct prefix_ipv4 *p4;
 146   struct prefix_ipv6 *p6;
 147 } __attribute__ ((transparent_union));
 148
 149 union prefix46constptr
 150 {
 151   const struct prefix *p;
 152   const struct prefix_ipv4 *p4;
 153   const struct prefix_ipv6 *p6;
 154 } __attribute__ ((transparent_union));
 155
 156 #ifndef INET_ADDRSTRLEN
 157 #define INET_ADDRSTRLEN 16
 158 #endif /* INET_ADDRSTRLEN */
 159
 160 #ifndef INET6_ADDRSTRLEN
 161 #define INET6_ADDRSTRLEN 46
 162 #endif /* INET6_ADDRSTRLEN */
 163
 164 #ifndef INET6_BUFSIZ
 165 #define INET6_BUFSIZ 51
 166 #endif /* INET6_BUFSIZ */
 167
 168 /* Maximum prefix string length (IPv6) */
 169 #define PREFIX_STRLEN 51
 170
 171 /* Max bit/byte length of IPv4 address. */
 172 #define IPV4_MAX_BYTELEN    4
 173 #define IPV4_MAX_BITLEN    32
 174 #define IPV4_MAX_PREFIXLEN 32
 175 #define IPV4_ADDR_CMP(D,S)   memcmp ((D), (S), IPV4_MAX_BYTELEN)
 176 #define IPV4_ADDR_SAME(D,S)  (memcmp ((D), (S), IPV4_MAX_BYTELEN) == 0)
 177 #define IPV4_ADDR_COPY(D,S)  memcpy ((D), (S), IPV4_MAX_BYTELEN)
 178
 179 #define IPV4_NET0(a)    ((((u_int32_t) (a)) & 0xff000000) == 0x00000000)
 180 #define IPV4_NET127(a)  ((((u_int32_t) (a)) & 0xff000000) == 0x7f000000)
 181 #define IPV4_LINKLOCAL(a) ((((u_int32_t) (a)) & 0xffff0000) == 0xa9fe0000)
 182 #define IPV4_CLASS_DE(a)  ((((u_int32_t) (a)) & 0xe0000000) == 0xe0000000)
 183
 184 /* Max bit/byte length of IPv6 address. */
 185 #define IPV6_MAX_BYTELEN    16
 186 #define IPV6_MAX_BITLEN    128
 187 #define IPV6_MAX_PREFIXLEN 128
 188 #define IPV6_ADDR_CMP(D,S)   memcmp ((D), (S), IPV6_MAX_BYTELEN)
 189 #define IPV6_ADDR_SAME(D,S)  (memcmp ((D), (S), IPV6_MAX_BYTELEN) == 0)
 190 #define IPV6_ADDR_COPY(D,S)  memcpy ((D), (S), IPV6_MAX_BYTELEN)
 191
 192 /* Count prefix size from mask length */
 193 #define PSIZE(a) (((a) + 7) / (8))
 194
 195 /* Prefix's family member. */
 196 #define PREFIX_FAMILY(p)  ((p)->family)
 197
 198 /* glibc defines s6_addr32 to __in6_u.__u6_addr32 if __USE_{MISC || GNU} */
 199 #ifndef s6_addr32
 200 #if defined(SUNOS_5)
 201 /* Some SunOS define s6_addr32 only to kernel */
 202 #define s6_addr32 _S6_un._S6_u32
 203 #else
 204 #define s6_addr32 __u6_addr.__u6_addr32
 205 #endif /* SUNOS_5 */
 206 #endif /*s6_addr32*/
 207
 208 /* Prototypes. */
 209 extern int str2family(const char *);
 210 extern int afi2family (afi_t);
 211 extern afi_t family2afi (int);
 212 extern const char *safi2str(safi_t safi);
 213 extern const char *afi2str(afi_t afi);
 214
 215 /* Check bit of the prefix. */
 216 extern unsigned int prefix_bit (const u_char *prefix, const u_char prefixlen);
 217 extern unsigned int prefix6_bit (const struct in6_addr *prefix, const u_char prefixlen);
 218
 219 extern struct prefix *prefix_new (void);
 220 extern void prefix_free (struct prefix *);
 221 extern const char *prefix_family_str (const struct prefix *);
 222 extern int prefix_blen (const struct prefix *);
 223 extern int str2prefix (const char *, struct prefix *);
 224
 225 /*
 226  * 8 groups of 4 bytes of hexadecimal + 7 seperators is 39
 227  * /128 = 4 bytes
 228  * Null = 1 byte
 229  * 39 + 4 + 1 = 44 bytes
 230  */
 231 #define PREFIX2STR_BUFFER  44
 232 extern const char *prefix2str (union prefix46constptr, char *, int);
 233 extern int prefix_match (const struct prefix *, const struct prefix *);
 234 extern int prefix_same (const struct prefix *, const struct prefix *);
 235 extern int prefix_cmp (const struct prefix *, const struct prefix *);
 236 extern int prefix_common_bits (const struct prefix *, const struct prefix *);
 237 extern void prefix_copy (struct prefix *dest, const struct prefix *src);
 238 extern void apply_mask (struct prefix *);
 239
 240 extern struct prefix *sockunion2prefix (const union sockunion *dest,
 241                                         const union sockunion *mask);
 242 extern struct prefix *sockunion2hostprefix (const union sockunion *, struct prefix *p);
 243 extern void prefix2sockunion (const struct prefix *, union sockunion *);
 244
 245 extern int str2prefix_eth (const char *, struct prefix_eth *);
 246
 247 extern struct prefix_ipv4 *prefix_ipv4_new (void);
 248 extern void prefix_ipv4_free (struct prefix_ipv4 *);
 249 extern int str2prefix_ipv4 (const char *, struct prefix_ipv4 *);
 250 extern void apply_mask_ipv4 (struct prefix_ipv4 *);
 251
 252 #define PREFIX_COPY_IPV4(DST, SRC)      \
 253         *((struct prefix_ipv4 *)(DST)) = *((const struct prefix_ipv4 *)(SRC));
 254
 255 extern int prefix_ipv4_any (const struct prefix_ipv4 *);
 256 extern void apply_classful_mask_ipv4 (struct prefix_ipv4 *);
 257
 258 extern u_char ip_masklen (struct in_addr);
 259 extern void masklen2ip (const int, struct in_addr *);
 260 /* returns the network portion of the host address */
 261 extern in_addr_t ipv4_network_addr (in_addr_t hostaddr, int masklen);
 262 /* given the address of a host on a network and the network mask length,
 263  * calculate the broadcast address for that network;
 264  * special treatment for /31: returns the address of the other host
 265  * on the network by flipping the host bit */
 266 extern in_addr_t ipv4_broadcast_addr (in_addr_t hostaddr, int masklen);
 267
 268 extern int netmask_str2prefix_str (const char *, const char *, char *);
 269
 270 extern struct prefix_ipv6 *prefix_ipv6_new (void);
 271 extern void prefix_ipv6_free (struct prefix_ipv6 *);
 272 extern int str2prefix_ipv6 (const char *, struct prefix_ipv6 *);
 273 extern void apply_mask_ipv6 (struct prefix_ipv6 *);
 274
 275 #define PREFIX_COPY_IPV6(DST, SRC)      \
 276         *((struct prefix_ipv6 *)(DST)) = *((const struct prefix_ipv6 *)(SRC));
 277
 278 extern int ip6_masklen (struct in6_addr);
 279 extern void masklen2ip6 (const int, struct in6_addr *);
 280
 281 extern void str2in6_addr (const char *, struct in6_addr *);
 282 extern const char *inet6_ntoa (struct in6_addr);
 283
 284 static inline int ipv6_martian (struct in6_addr *addr)
 285 {
 286   struct in6_addr localhost_addr;
 287
 288   inet_pton (AF_INET6, "::1", &localhost_addr);
 289
 290   if (IPV6_ADDR_SAME(&localhost_addr, addr))
 291     return 1;
 292
 293   return 0;
 294 }
 295
 296 extern int all_digit (const char *);
 297
 298 /* NOTE: This routine expects the address argument in network byte order. */
 299 static inline int ipv4_martian (struct in_addr *addr)
 300 {
 301   in_addr_t ip = ntohl(addr->s_addr);
 302
 303   if (IPV4_NET0(ip) || IPV4_NET127(ip) || IPV4_CLASS_DE(ip)) {
 304     return 1;
 305   }
 306   return 0;
 307 }
 308
 309 static inline int
 310 is_default_prefix (struct prefix *p)
 311 {
 312   if (!p)
 313     return 0;
 314
 315   if (((p->family == AF_INET) && (p->u.prefix4.s_addr == INADDR_ANY))
 316       || ((p->family == AF_INET6) &&
 317           !memcmp(&p->u.prefix6, &in6addr_any, sizeof (struct in6_addr))))
 318     return 1;
 319
 320   return 0;
 321 }
 322
 323 #endif /* _ZEBRA_PREFIX_H */