addrconf_core.c

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/*
 * IPv6 library code, needed by static components when full IPv6 support is
 * not configured or static.
 */

#include <linux/export.h>
#include <net/ipv6.h>

#define IPV6_ADDR_SCOPE_TYPE(scope) ((scope) << 16)

static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
{
    switch (scope) {
    case IPV6_ADDR_SCOPE_NODELOCAL:
        return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
            IPV6_ADDR_LOOPBACK);
    case IPV6_ADDR_SCOPE_LINKLOCAL:
        return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
            IPV6_ADDR_LINKLOCAL);
    case IPV6_ADDR_SCOPE_SITELOCAL:
        return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
            IPV6_ADDR_SITELOCAL);
    }
    return IPV6_ADDR_SCOPE_TYPE(scope);
}

int __ipv6_addr_type(const struct in6_addr *addr)
{
    __be32 st;

    st = addr->s6_addr32[0];

    /* Consider all addresses with the first three bits different of
       000 and 111 as unicasts.
     */
    if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
        (st & htonl(0xE0000000)) != htonl(0xE0000000))
        return (IPV6_ADDR_UNICAST |
            IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));

    if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
        /* multicast */
        /* addr-select 3.1 */
        return (IPV6_ADDR_MULTICAST |
            ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
    }

    if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
        return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
            IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));       /* addr-select 3.1 */
    if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
        return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
            IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));       /* addr-select 3.1 */
    if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
        return (IPV6_ADDR_UNICAST |
            IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));          /* RFC 4193 */

    if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
        if (addr->s6_addr32[2] == 0) {
            if (addr->s6_addr32[3] == 0)
                return IPV6_ADDR_ANY;

            if (addr->s6_addr32[3] == htonl(0x00000001))
                return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
                    IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));   /* addr-select 3.4 */

            return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
                IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
        }

        if (addr->s6_addr32[2] == htonl(0x0000ffff))
            return (IPV6_ADDR_MAPPED |
                IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
    }

    return (IPV6_ADDR_UNICAST |
        IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.4 */
}
EXPORT_SYMBOL(__ipv6_addr_type);