linux/net/ipv6/addrconf_core.c
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   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
  10static 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
  26int __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_RESERVED |
  76                IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.4 */
  77}
  78EXPORT_SYMBOL(__ipv6_addr_type);
  79
  80