isc/unix/net.c

	net.c revision 70c91849c3a3d808125d690a46af5fd225a4c291
/*
 * Copyright (C) 1999, 2000  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: net.c,v 1.16 2000/12/19 19:29:13 gson Exp $ */

#include <config.h>

#include <errno.h>
#include <unistd.h>

#include <isc/log.h>
#include <isc/msgs.h>
#include <isc/net.h>
#include <isc/once.h>
#include <isc/string.h>
#include <isc/util.h>

#if defined(ISC_PLATFORM_HAVEIPV6) && defined(ISC_PLATFORM_NEEDIN6ADDRANY)
const struct in6_addr isc_net_in6addrany = IN6ADDR_ANY_INIT;
#endif

static isc_once_t   once = ISC_ONCE_INIT;
static isc_result_t ipv4_result = ISC_R_NOTFOUND;
static isc_result_t ipv6_result = ISC_R_NOTFOUND;

static isc_result_t
try_proto(int domain) {
    int s;
    isc_result_t result = ISC_R_SUCCESS;

    s = socket(domain, SOCK_STREAM, 0);
    if (s == -1) {
        switch (errno) {
#ifdef EAFNOSUPPORT
        case EAFNOSUPPORT:
#endif
#ifdef EPROTONOSUPPORT
        case EPROTONOSUPPORT:
#endif
#ifdef EINVAL
        case EINVAL:
#endif
            return (ISC_R_NOTFOUND);
        default:
            UNEXPECTED_ERROR(__FILE__, __LINE__,
                     "socket() %s: %s",
                     isc_msgcat_get(isc_msgcat,
                            ISC_MSGSET_GENERAL,
                            ISC_MSG_FAILED,
                            "failed"),
                     strerror(errno));
            return (ISC_R_UNEXPECTED);
        }
    }

#ifdef ISC_PLATFORM_HAVEIPV6
#ifdef WANT_IPV6
#ifdef ISC_PLATFORM_HAVEIN6PKTINFO
    if (domain == PF_INET6) {
        struct sockaddr_in6 sin6;
        unsigned int len;

        /*
         * Check to see if IPv6 is broken, as is common on Linux.
         */
        len = sizeof(sin6);
        if (getsockname(s, (struct sockaddr *)&sin6, (void *)&len) < 0) {
            isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
                      ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
                      "Retrieving the address of an IPv6 "
                      "socket from the kernel failed.");
            isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
                      ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR,
                      "IPv6 support is disabled.");
            result = ISC_R_NOTFOUND;
        } else {
            if (len == sizeof(struct sockaddr_in6))
                result = ISC_R_SUCCESS;
            else {
                isc_log_write(isc_lctx,
                          ISC_LOGCATEGORY_GENERAL,
                          ISC_LOGMODULE_SOCKET,
                          ISC_LOG_ERROR,
                          "IPv6 structures in kernel and "
                          "user space do not match.");
                isc_log_write(isc_lctx,
                          ISC_LOGCATEGORY_GENERAL,
                          ISC_LOGMODULE_SOCKET,
                          ISC_LOG_ERROR,
                          "IPv6 support is disabled.");
                result = ISC_R_NOTFOUND;
            }
        }
    }
#endif
#endif
#endif

    close(s);

    return (result);
}

static void
initialize_action(void) {
    ipv4_result = try_proto(PF_INET);
#ifdef ISC_PLATFORM_HAVEIPV6
#ifdef WANT_IPV6
#ifdef ISC_PLATFORM_HAVEIN6PKTINFO
    ipv6_result = try_proto(PF_INET6);
#else
    ipv6_result = 0;
#endif
#endif
#endif
}

static void
initialize(void) {
    RUNTIME_CHECK(isc_once_do(&once, initialize_action) == ISC_R_SUCCESS);
}

isc_result_t
isc_net_probeipv4(void) {

    /*
     * Check if the system's kernel supports IPv4.
     */

    initialize();
    return (ipv4_result);
}

isc_result_t
isc_net_probeipv6(void) {

    /*
     * Check if the system's kernel supports IPv6.
     */

    initialize();
    return (ipv6_result);
}