net/ipv6/addrconf_core.c

   1 /*
   2  * IPv6 library code, needed by static components when full IPv6 support is
   3  * not configured or static.
   4  */
   5
   6 #include <linux/export.h>
   7 #include <net/ipv6.h>
   8
   9 #define IPV6_ADDR_SCOPE_TYPE(scope)     ((scope) << 16)
  10
  11 static inline unsigned ipv6_addr_scope2type(unsigned scope)
  12 {
  13         switch(scope) {
  14         case IPV6_ADDR_SCOPE_NODELOCAL:
  15                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
  16                         IPV6_ADDR_LOOPBACK);
  17         case IPV6_ADDR_SCOPE_LINKLOCAL:
  18                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
  19                         IPV6_ADDR_LINKLOCAL);
  20         case IPV6_ADDR_SCOPE_SITELOCAL:
  21                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
  22                         IPV6_ADDR_SITELOCAL);
  23         }
  24         return IPV6_ADDR_SCOPE_TYPE(scope);
  25 }
  26
  27 int __ipv6_addr_type(const struct in6_addr *addr)
  28 {
  29         __be32 st;
  30
  31         st = addr->s6_addr32[0];
  32
  33         /* Consider all addresses with the first three bits different of
  34            000 and 111 as unicasts.
  35          */
  36         if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
  37             (st & htonl(0xE0000000)) != htonl(0xE0000000))
  38                 return (IPV6_ADDR_UNICAST |
  39                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
  40
  41         if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
  42                 /* multicast */
  43                 /* addr-select 3.1 */
  44                 return (IPV6_ADDR_MULTICAST |
  45                         ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
  46         }
  47
  48         if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
  49                 return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
  50                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));               /* addr-select 3.1 */
  51         if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
  52                 return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
  53                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));               /* addr-select 3.1 */
  54         if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
  55                 return (IPV6_ADDR_UNICAST |
  56                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));                  /* RFC 4193 */
  57
  58         if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
  59                 if (addr->s6_addr32[2] == 0) {
  60                         if (addr->s6_addr32[3] == 0)
  61                                 return IPV6_ADDR_ANY;
  62
  63                         if (addr->s6_addr32[3] == htonl(0x00000001))
  64                                 return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
  65                                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));       /* addr-select 3.4 */
  66
  67                         return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
  68                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  69                 }
  70
  71                 if (addr->s6_addr32[2] == htonl(0x0000ffff))
  72                         return (IPV6_ADDR_MAPPED |
  73                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  74         }
  75
  76         return (IPV6_ADDR_UNICAST |
  77                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.4 */
  78 }
  79 EXPORT_SYMBOL(__ipv6_addr_type);
  80