LXR linux/net/ipv6/addrconf

   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
  11static 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
  27int __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}
  79EXPORT_SYMBOL(__ipv6_addr_type);
  80
  81