netaddr.c

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/*
 * Copyright (C) 2004, 2005, 2007, 2010-2012, 2014  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/* $Id$ */

/*! \file */

#include <config.h>

#include <stdio.h>

#include <isc/buffer.h>
#include <isc/msgs.h>
#include <isc/net.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 ||
                    a->zone != b->zone)
                        return (ISC_FALSE);
                break;
#ifdef ISC_PLATFORM_HAVESYSUNH
        case AF_UNIX:
                if (strcmp(a->type.un, b->type.un) != 0)
                        return (ISC_FALSE);
                break;
#endif
        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 = NULL, *pb = NULL;
        unsigned int ipabytes = 0; /* 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 && b->zone != 0)
                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:
                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;
#ifdef ISC_PLATFORM_HAVESYSUNH
        case AF_UNIX:
                alen = strlen(netaddr->type.un);
                if (alen > isc_buffer_availablelength(target))
                        return (ISC_R_NOSPACE);
                isc_buffer_putmem(target,
                                  (const unsigned char *)(netaddr->type.un),
                                  alen);
                return (ISC_R_SUCCESS);
#endif
        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);

        if (size == 0)
                return;

        /*
         * 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_prefixok(const isc_netaddr_t *na, unsigned int prefixlen) {
        static const unsigned char zeros[16];
        unsigned int nbits, nbytes, ipbytes = 0;
        const unsigned char *p;

        switch (na->family) {
        case AF_INET:
                p = (const unsigned char *) &na->type.in;
                ipbytes = 4;
                if (prefixlen > 32)
                        return (ISC_R_RANGE);
                break;
        case AF_INET6:
                p = (const unsigned char *) &na->type.in6;
                ipbytes = 16;
                if (prefixlen > 128)
                        return (ISC_R_RANGE);
                break;
        default:
                return (ISC_R_NOTIMPLEMENTED);
        }
        nbytes = prefixlen / 8;
        nbits = prefixlen % 8;
        if (nbits != 0) {
                INSIST(nbytes < ipbytes);
                if ((p[nbytes] & (0xff>>nbits)) != 0U)
                        return (ISC_R_FAILURE);
                nbytes++;
        }
        if (nbytes < ipbytes && memcmp(p + nbytes, zeros, ipbytes - nbytes) != 0)
                return (ISC_R_FAILURE);
        return (ISC_R_SUCCESS);
}

isc_result_t
isc_netaddr_masktoprefixlen(const isc_netaddr_t *s, unsigned int *lenp) {
        unsigned int nbits = 0, nbytes = 0, ipbytes = 0, 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:
                return (ISC_R_NOTIMPLEMENTED);
        }
        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;
}

isc_result_t
isc_netaddr_frompath(isc_netaddr_t *netaddr, const char *path) {
#ifdef ISC_PLATFORM_HAVESYSUNH
        if (strlen(path) > sizeof(netaddr->type.un) - 1)
                return (ISC_R_NOSPACE);

        memset(netaddr, 0, sizeof(*netaddr));
        netaddr->family = AF_UNIX;
        strcpy(netaddr->type.un, path);
        netaddr->zone = 0;
        return (ISC_R_SUCCESS);
#else
        UNUSED(netaddr);
        UNUSED(path);
        return (ISC_R_NOTIMPLEMENTED);
#endif
}


void
isc_netaddr_setzone(isc_netaddr_t *netaddr, isc_uint32_t zone) {
        /* we currently only support AF_INET6. */
        REQUIRE(netaddr->family == AF_INET6);

        netaddr->zone = zone;
}

isc_uint32_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;
                t->zone = 0;
                break;
        case AF_INET6:
                memmove(&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;
#ifdef ISC_PLATFORM_HAVESYSUNH
        case AF_UNIX:
                memmove(t->type.un, s->type.sunix.sun_path, sizeof(t->type.un));
                t->zone = 0;
                break;
#endif
        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_isexperimental(isc_netaddr_t *na) {
        switch (na->family) {
        case AF_INET:
                return (ISC_TF(ISC_IPADDR_ISEXPERIMENTAL(na->type.in.s_addr)));
        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;
        memmove(&t->type.in, (char *)&src->type.in6 + 12, 4);
        return;
}

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