lib/bind9/getaddresses.c

	getaddresses.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
 * Copyright (C) 2001, 2002, 2004, 2005, 2007, 2014-2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/* $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);
}