getaddresses.c

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/*
 * Copyright (C) 2004, 2005, 2007, 2014, 2015  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2001, 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: getaddresses.c,v 1.22 2007/06/19 23:47:16 tbox Exp $ */

/*! \file */

#include <config.h>
#include <string.h>

#include <isc/net.h>
#include <isc/netaddr.h>
#include <isc/netdb.h>
#include <isc/netscope.h>
#include <isc/result.h>
#include <isc/sockaddr.h>
#include <isc/util.h>

#include <bind9/getaddresses.h>

#ifdef HAVE_ADDRINFO
#ifdef HAVE_GETADDRINFO
#ifdef HAVE_GAISTRERROR
#define USE_GETADDRINFO
#endif
#endif
#endif

#ifndef USE_GETADDRINFO
#ifndef ISC_PLATFORM_NONSTDHERRNO
extern int h_errno;
#endif
#endif

isc_result_t
bind9_getaddresses(const char *hostname, in_port_t port,
                   isc_sockaddr_t *addrs, int addrsize, int *addrcount)
{
        struct in_addr in4;
        struct in6_addr in6;
        isc_boolean_t have_ipv4, have_ipv6;
        int i;

#ifdef USE_GETADDRINFO
        struct addrinfo *ai = NULL, *tmpai, hints;
        int result;
#else
        struct hostent *he;
#endif

        REQUIRE(hostname != NULL);
        REQUIRE(addrs != NULL);
        REQUIRE(addrcount != NULL);
        REQUIRE(addrsize > 0);

        have_ipv4 = ISC_TF((isc_net_probeipv4() == ISC_R_SUCCESS));
        have_ipv6 = ISC_TF((isc_net_probeipv6() == ISC_R_SUCCESS));

        /*
         * Try IPv4, then IPv6.  In order to handle the extended format
         * for IPv6 scoped addresses (address%scope_ID), we'll use a local
         * working buffer of 128 bytes.  The length is an ad-hoc value, but
         * should be enough for this purpose; the buffer can contain a string
         * of at least 80 bytes for scope_ID in addition to any IPv6 numeric
         * addresses (up to 46 bytes), the delimiter character and the
         * terminating NULL character.
         */
        if (inet_pton(AF_INET, hostname, &in4) == 1) {
                if (have_ipv4)
                        isc_sockaddr_fromin(&addrs[0], &in4, port);
                else
                        isc_sockaddr_v6fromin(&addrs[0], &in4, port);
                *addrcount = 1;
                return (ISC_R_SUCCESS);
        } else if (strlen(hostname) <= 127U) {
                char tmpbuf[128], *d;
                isc_uint32_t zone = 0;

                strcpy(tmpbuf, hostname);
                d = strchr(tmpbuf, '%');
                if (d != NULL)
                        *d = '\0';

                if (inet_pton(AF_INET6, tmpbuf, &in6) == 1) {
                        isc_netaddr_t na;

                        if (!have_ipv6)
                                return (ISC_R_FAMILYNOSUPPORT);

                        if (d != NULL) {
#ifdef ISC_PLATFORM_HAVESCOPEID
                                isc_result_t iresult;

                                iresult = isc_netscope_pton(AF_INET6, d + 1,
                                                            &in6, &zone);

                                if (iresult != ISC_R_SUCCESS)
                                        return (iresult);
#else
                                /*
                                 * The extended format is specified while the
                                 * system does not provide the ability to use
                                 * it.  Throw an explicit error instead of
                                 * ignoring the specified value.
                                 */
                                return (ISC_R_BADADDRESSFORM);
#endif
                        }

                        isc_netaddr_fromin6(&na, &in6);
                        isc_netaddr_setzone(&na, zone);
                        isc_sockaddr_fromnetaddr(&addrs[0],
                                                 (const isc_netaddr_t *)&na,
                                                 port);

                        *addrcount = 1;
                        return (ISC_R_SUCCESS);
                }
        }
#ifdef USE_GETADDRINFO
        memset(&hints, 0, sizeof(hints));
        if (!have_ipv6)
                hints.ai_family = PF_INET;
        else if (!have_ipv4)
                hints.ai_family = PF_INET6;
        else {
                hints.ai_family = PF_UNSPEC;
#ifdef AI_ADDRCONFIG
                hints.ai_flags = AI_ADDRCONFIG;
#endif
        }
        hints.ai_socktype = SOCK_STREAM;
#ifdef AI_ADDRCONFIG
 again:
#endif
        result = getaddrinfo(hostname, NULL, &hints, &ai);
        switch (result) {
        case 0:
                break;
        case EAI_NONAME:
#if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME)
        case EAI_NODATA:
#endif
                return (ISC_R_NOTFOUND);
#ifdef AI_ADDRCONFIG
        case EAI_BADFLAGS:
                if ((hints.ai_flags & AI_ADDRCONFIG) != 0) {
                        hints.ai_flags &= ~AI_ADDRCONFIG;
                        goto again;
                }
#endif
        default:
                return (ISC_R_FAILURE);
        }
        for (tmpai = ai, i = 0;
             tmpai != NULL && i < addrsize;
             tmpai = tmpai->ai_next)
        {
                if (tmpai->ai_family != AF_INET &&
                    tmpai->ai_family != AF_INET6)
                        continue;
                if (tmpai->ai_family == AF_INET) {
                        struct sockaddr_in *sin;
                        sin = (struct sockaddr_in *)tmpai->ai_addr;
                        isc_sockaddr_fromin(&addrs[i], &sin->sin_addr, port);
                } else {
                        struct sockaddr_in6 *sin6;
                        sin6 = (struct sockaddr_in6 *)tmpai->ai_addr;
                        isc_sockaddr_fromin6(&addrs[i], &sin6->sin6_addr,
                                             port);
                }
                i++;

        }
        freeaddrinfo(ai);
        *addrcount = i;
#else
        he = gethostbyname(hostname);
        if (he == NULL) {
                switch (h_errno) {
                case HOST_NOT_FOUND:
#ifdef NO_DATA
                case NO_DATA:
#endif
#if defined(NO_ADDRESS) && (!defined(NO_DATA) || (NO_DATA != NO_ADDRESS))
                case NO_ADDRESS:
#endif
                        return (ISC_R_NOTFOUND);
                default:
                        return (ISC_R_FAILURE);
                }
        }
        if (he->h_addrtype != AF_INET && he->h_addrtype != AF_INET6)
                return (ISC_R_NOTFOUND);
        for (i = 0; i < addrsize; i++) {
                if (he->h_addrtype == AF_INET) {
                        struct in_addr *inp;
                        inp = (struct in_addr *)(he->h_addr_list[i]);
                        if (inp == NULL)
                                break;
                        isc_sockaddr_fromin(&addrs[i], inp, port);
                } else {
                        struct in6_addr *in6p;
                        in6p = (struct in6_addr *)(he->h_addr_list[i]);
                        if (in6p == NULL)
                                break;
                        isc_sockaddr_fromin6(&addrs[i], in6p, port);
                }
        }
        *addrcount = i;
#endif
        if (*addrcount == 0)
                return (ISC_R_NOTFOUND);
        else
                return (ISC_R_SUCCESS);
}

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