lib/isc/netaddr.c

	netaddr.c revision 6526fd032fc418411da3af4201214e95c113d3e2
/*
 * Copyright (C) 1999-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: netaddr.c,v 1.23 2002/10/24 03:52:32 marka Exp $ */

#include <config.h>

#include <stdio.h>

#include <isc/buffer.h>
#include <isc/msgs.h>
#include <isc/netaddr.h>
#include <isc/print.h>
#include <isc/sockaddr.h>
#include <isc/string.h>
#include <isc/util.h>

isc_boolean_t
isc_netaddr_equal(const isc_netaddr_t *a, const isc_netaddr_t *b) {
    REQUIRE(a != NULL && b != NULL);

    if (a->family != b->family)
        return (ISC_FALSE);

    if (a->zone != b->zone)
        return (ISC_FALSE);

    switch (a->family) {
    case AF_INET:
        if (a->type.in.s_addr != b->type.in.s_addr)
            return (ISC_FALSE);
        break;
    case AF_INET6:
        if (memcmp(&a->type.in6, &b->type.in6,
               sizeof(a->type.in6)) != 0)
            return (ISC_FALSE);
        break;
    default:
        return (ISC_FALSE);
    }
    return (ISC_TRUE);
}

isc_boolean_t
isc_netaddr_eqprefix(const isc_netaddr_t *a, const isc_netaddr_t *b,
             unsigned int prefixlen)
{
    const unsigned char *pa, *pb;
    unsigned int ipabytes; /* Length of whole IP address in bytes */
    unsigned int nbytes;   /* Number of significant whole bytes */
    unsigned int nbits;    /* Number of significant leftover bits */

    REQUIRE(a != NULL && b != NULL);

    if (a->family != b->family)
        return (ISC_FALSE);

    if (a->zone != b->zone)
        return (ISC_FALSE);

    switch (a->family) {
    case AF_INET:
        pa = (const unsigned char *) &a->type.in;
        pb = (const unsigned char *) &b->type.in;
        ipabytes = 4;
        break;
    case AF_INET6:
        pa = (const unsigned char *) &a->type.in6;
        pb = (const unsigned char *) &b->type.in6;
        ipabytes = 16;
        break;
    default:
        pa = pb = NULL; /* Avoid silly compiler warning. */
        ipabytes = 0; /* Ditto. */
        return (ISC_FALSE);
    }

    /*
     * Don't crash if we get a pattern like 10.0.0.1/9999999.
     */
    if (prefixlen > ipabytes * 8)
        prefixlen = ipabytes * 8;

    nbytes = prefixlen / 8;
    nbits = prefixlen % 8;

    if (nbytes > 0) {
        if (memcmp(pa, pb, nbytes) != 0)
            return (ISC_FALSE);
    }
    if (nbits > 0) {
        unsigned int bytea, byteb, mask;
        INSIST(nbytes < ipabytes);
        INSIST(nbits < 8);
        bytea = pa[nbytes];
        byteb = pb[nbytes];
        mask = (0xFF << (8-nbits)) & 0xFF;
        if ((bytea & mask) != (byteb & mask))
            return (ISC_FALSE);
    }
    return (ISC_TRUE);
}

isc_result_t
isc_netaddr_totext(const isc_netaddr_t *netaddr, isc_buffer_t *target) {
    char abuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
    char zbuf[sizeof("%4294967295")];
    unsigned int alen;
    int zlen;
    const char *r;
    const void *type;

    REQUIRE(netaddr != NULL);

    switch (netaddr->family) {
    case AF_INET:
        type = &netaddr->type.in;
        break;
    case AF_INET6:
        type = &netaddr->type.in6;
        break;
    default:
        return (ISC_R_FAILURE);
    }
    r = inet_ntop(netaddr->family, type, abuf, sizeof(abuf));
    if (r == NULL)
        return (ISC_R_FAILURE);

    alen = strlen(abuf);
    INSIST(alen < sizeof(abuf));

    zlen = 0;
    if (netaddr->family == AF_INET6 && netaddr->zone != 0) {
        zlen = snprintf(zbuf, sizeof(zbuf), "%%%u", netaddr->zone);
        if (zlen < 0)
            return (ISC_R_FAILURE);
        INSIST((unsigned int)zlen < sizeof(zbuf));
    }

    if (alen + zlen > isc_buffer_availablelength(target))
        return (ISC_R_NOSPACE);

    isc_buffer_putmem(target, (unsigned char *)abuf, alen);
    isc_buffer_putmem(target, (unsigned char *)zbuf, zlen);

    return (ISC_R_SUCCESS);
}

void
isc_netaddr_format(const isc_netaddr_t *na, char *array, unsigned int size) {
    isc_result_t result;
    isc_buffer_t buf;

    isc_buffer_init(&buf, array, size);
    result = isc_netaddr_totext(na, &buf);

    /*
     * Null terminate.
     */
    if (result == ISC_R_SUCCESS) {
        if (isc_buffer_availablelength(&buf) >= 1)
            isc_buffer_putuint8(&buf, 0);
        else
            result = ISC_R_NOSPACE;
    }

    if (result != ISC_R_SUCCESS) {
        snprintf(array, size,
             isc_msgcat_get(isc_msgcat, ISC_MSGSET_NETADDR,
                    ISC_MSG_UNKNOWNADDR,
                    "<unknown address, family %u>"),
             na->family);
        array[size - 1] = '\0';
    }
}

isc_result_t
isc_netaddr_masktoprefixlen(const isc_netaddr_t *s, unsigned int *lenp) {
    unsigned int nbits, nbytes, ipbytes, i;
    const unsigned char *p;

    switch (s->family) {
    case AF_INET:
        p = (const unsigned char *) &s->type.in;
        ipbytes = 4;
        break;
    case AF_INET6:
        p = (const unsigned char *) &s->type.in6;
        ipbytes = 16;
        break;
    default:
        ipbytes = 0;
        return (ISC_R_NOTIMPLEMENTED);
    }
    nbytes = nbits = 0;
    for (i = 0; i < ipbytes; i++) {
        if (p[i] != 0xFF)
            break;
    }
    nbytes = i;
    if (i < ipbytes) {
        unsigned int c = p[nbytes];
        while ((c & 0x80) != 0 && nbits < 8) {
            c <<= 1; nbits++;
        }
        if ((c & 0xFF) != 0)
            return (ISC_R_MASKNONCONTIG);
        i++;
    }
    for (; i < ipbytes; i++) {
        if (p[i] != 0)
            return (ISC_R_MASKNONCONTIG);
        i++;
    }
    *lenp = nbytes * 8 + nbits;
    return (ISC_R_SUCCESS);
}

void
isc_netaddr_fromin(isc_netaddr_t *netaddr, const struct in_addr *ina) {
    memset(netaddr, 0, sizeof(*netaddr));
    netaddr->family = AF_INET;
    netaddr->type.in = *ina;
}

void
isc_netaddr_fromin6(isc_netaddr_t *netaddr, const struct in6_addr *ina6) {
    memset(netaddr, 0, sizeof(*netaddr));
    netaddr->family = AF_INET6;
    netaddr->type.in6 = *ina6;
}

void
isc_netaddr_setzone(isc_netaddr_t *netaddr, u_int32_t zone) {
    /* we currently only support AF_INET6. */
    REQUIRE(netaddr->family == AF_INET6);

    netaddr->zone = zone;
}

u_int32_t
isc_netaddr_getzone(const isc_netaddr_t *netaddr) {
    return (netaddr->zone);
}

void
isc_netaddr_fromsockaddr(isc_netaddr_t *t, const isc_sockaddr_t *s) {
    int family = s->type.sa.sa_family;
    t->family = family;
    switch (family) {
    case AF_INET:
        t->type.in = s->type.sin.sin_addr;
        break;
    case AF_INET6:
        memcpy(&t->type.in6, &s->type.sin6.sin6_addr, 16);
#ifdef ISC_PLATFORM_HAVESCOPEID
        t->zone = s->type.sin6.sin6_scope_id;
#else
        t->zone = 0;
#endif
        break;
    default:
        INSIST(0);
    }
}

void
isc_netaddr_any(isc_netaddr_t *netaddr) {
    memset(netaddr, 0, sizeof(*netaddr));
    netaddr->family = AF_INET;
    netaddr->type.in.s_addr = INADDR_ANY;
}

void
isc_netaddr_any6(isc_netaddr_t *netaddr) {
    memset(netaddr, 0, sizeof(*netaddr));
    netaddr->family = AF_INET6;
    netaddr->type.in6 = in6addr_any;
}

isc_boolean_t
isc_netaddr_ismulticast(isc_netaddr_t *na) {
    switch (na->family) {
    case AF_INET:
        return (ISC_TF(ISC_IPADDR_ISMULTICAST(na->type.in.s_addr)));
    case AF_INET6:
        return (ISC_TF(IN6_IS_ADDR_MULTICAST(&na->type.in6)));
    default:
        return (ISC_FALSE);  /* XXXMLG ? */
    }
}

isc_boolean_t
isc_netaddr_islinklocal(isc_netaddr_t *na) {
    switch (na->family) {
    case AF_INET:
        return (ISC_FALSE);
    case AF_INET6:
        return (ISC_TF(IN6_IS_ADDR_LINKLOCAL(&na->type.in6)));
    default:
        return (ISC_FALSE);
    }
}

isc_boolean_t
isc_netaddr_issitelocal(isc_netaddr_t *na) {
    switch (na->family) {
    case AF_INET:
        return (ISC_FALSE);
    case AF_INET6:
        return (ISC_TF(IN6_IS_ADDR_SITELOCAL(&na->type.in6)));
    default:
        return (ISC_FALSE);
    }
}

void
isc_netaddr_fromv4mapped(isc_netaddr_t *t, const isc_netaddr_t *s) {
    isc_netaddr_t *src;

    DE_CONST(s, src);   /* Must come before IN6_IS_ADDR_V4MAPPED. */

    REQUIRE(s->family == AF_INET6);
    REQUIRE(IN6_IS_ADDR_V4MAPPED(&src->type.in6));

    memset(t, 0, sizeof(*t));
    t->family = AF_INET;
    memcpy(&t->type.in, (char *)&src->type.in6 + 12, 4);
    return;
}