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 <net/ipv6.h>
   7
   8 #define IPV6_ADDR_SCOPE_TYPE(scope)     ((scope) << 16)
   9
  10 static inline unsigned ipv6_addr_scope2type(unsigned scope)
  11 {
  12         switch(scope) {
  13         case IPV6_ADDR_SCOPE_NODELOCAL:
  14                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
  15                         IPV6_ADDR_LOOPBACK);
  16         case IPV6_ADDR_SCOPE_LINKLOCAL:
  17                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
  18                         IPV6_ADDR_LINKLOCAL);
  19         case IPV6_ADDR_SCOPE_SITELOCAL:
  20                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
  21                         IPV6_ADDR_SITELOCAL);
  22         }
  23         return IPV6_ADDR_SCOPE_TYPE(scope);
  24 }
  25
  26 int __ipv6_addr_type(const struct in6_addr *addr)
  27 {
  28         __be32 st;
  29
  30         st = addr->s6_addr32[0];
  31
  32         /* Consider all addresses with the first three bits different of
  33            000 and 111 as unicasts.
  34          */
  35         if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
  36             (st & htonl(0xE0000000)) != htonl(0xE0000000))
  37                 return (IPV6_ADDR_UNICAST |
  38                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
  39
  40         if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
  41                 /* multicast */
  42                 /* addr-select 3.1 */
  43                 return (IPV6_ADDR_MULTICAST |
  44                         ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
  45         }
  46
  47         if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
  48                 return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
  49                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));               /* addr-select 3.1 */
  50         if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
  51                 return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
  52                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));               /* addr-select 3.1 */
  53         if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
  54                 return (IPV6_ADDR_UNICAST |
  55                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));                  /* RFC 4193 */
  56
  57         if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
  58                 if (addr->s6_addr32[2] == 0) {
  59                         if (addr->s6_addr32[3] == 0)
  60                                 return IPV6_ADDR_ANY;
  61
  62                         if (addr->s6_addr32[3] == htonl(0x00000001))
  63                                 return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
  64                                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));       /* addr-select 3.4 */
  65
  66                         return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
  67                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  68                 }
  69
  70                 if (addr->s6_addr32[2] == htonl(0x0000ffff))
  71                         return (IPV6_ADDR_MAPPED |
  72                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  73         }
  74
  75         return (IPV6_ADDR_UNICAST |
  76                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.4 */
  77 }
  78 EXPORT_SYMBOL(__ipv6_addr_type);
  79