libinetutil/common/ifaddrlistx.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <errno.h>
#include <libinetutil.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/sockio.h>

/*
 * Create a list of the addresses on physical interface `ifname' with at least
 * one of the flags in `set' set and all of the flags in `clear' clear.
 * Return the number of items in the list, or -1 on failure.
 */
int
ifaddrlistx(const char *ifname, uint64_t set, uint64_t clear,
    ifaddrlistx_t **ifaddrsp)
{
    struct lifconf  lifc;
    struct lifnum   lifn;
    struct lifreq   *lifrp;
    ifaddrlistx_t   *ifaddrp, *ifaddrs = NULL;
    int     i, nlifr, naddr = 0;
    char        *cp;
    uint_t      flags;
    int     s4, s6 = -1;
    boolean_t   isv6;
    int     save_errno;
    struct sockaddr_storage addr;

    (void) memset(&lifc, 0, sizeof (lifc));
    flags = LIFC_NOXMIT | LIFC_ALLZONES | LIFC_TEMPORARY | LIFC_UNDER_IPMP;

    /*
     * We need both IPv4 and IPv6 sockets to query both IPv4 and IPv6
     * interfaces below.
     */
    if ((s4 = socket(AF_INET, SOCK_DGRAM, 0)) == -1 ||
        (s6 = socket(AF_INET6, SOCK_DGRAM, 0)) == -1) {
        goto fail;
    }

    /*
     * Get the number of network interfaces of type `family'.
     */
    lifn.lifn_family = AF_UNSPEC;
    lifn.lifn_flags = flags;
again:
    if (ioctl(s4, SIOCGLIFNUM, &lifn) == -1)
        goto fail;

    /*
     * Pad the interface count to detect when additional interfaces have
     * been configured between SIOCGLIFNUM and SIOCGLIFCONF.
     */
    lifn.lifn_count += 4;

    lifc.lifc_flags = flags;
    lifc.lifc_family = AF_UNSPEC;
    lifc.lifc_len = lifn.lifn_count * sizeof (struct lifreq);
    if ((lifc.lifc_buf = realloc(lifc.lifc_buf, lifc.lifc_len)) == NULL)
        goto fail;

    if (ioctl(s4, SIOCGLIFCONF, &lifc) == -1)
        goto fail;

    /*
     * If every lifr_req slot is taken, then additional interfaces must
     * have been plumbed between the SIOCGLIFNUM and the SIOCGLIFCONF.
     * Recalculate to make sure we didn't miss any interfaces.
     */
    nlifr = lifc.lifc_len / sizeof (struct lifreq);
    if (nlifr >= lifn.lifn_count)
        goto again;

    /*
     * Populate the ifaddrlistx by querying each matching interface.  If a
     * query ioctl returns ENXIO, then the interface must have been
     * removed after the SIOCGLIFCONF completed -- so we just ignore it.
     */
    for (lifrp = lifc.lifc_req, i = 0; i < nlifr; i++, lifrp++) {
        if ((cp = strchr(lifrp->lifr_name, ':')) != NULL)
            *cp = '\0';

        if (strcmp(lifrp->lifr_name, ifname) != 0)
            continue;

        if (cp != NULL)
            *cp = ':';

        addr = lifrp->lifr_addr;
        isv6 = addr.ss_family == AF_INET6;
        if (ioctl(isv6 ? s6 : s4, SIOCGLIFFLAGS, lifrp) == -1) {
            if (errno == ENXIO)
                continue;
            goto fail;
        }

        if (set != 0 && ((lifrp->lifr_flags & set) == 0) ||
            (lifrp->lifr_flags & clear) != 0)
            continue;

        /*
         * We've got a match; allocate a new record.
         */
        if ((ifaddrp = malloc(sizeof (ifaddrlistx_t))) == NULL)
            goto fail;

        (void) strlcpy(ifaddrp->ia_name, lifrp->lifr_name, LIFNAMSIZ);
        ifaddrp->ia_flags = lifrp->lifr_flags;
        ifaddrp->ia_addr = addr;
        ifaddrp->ia_next = ifaddrs;
        ifaddrs = ifaddrp;
        naddr++;
    }

    (void) close(s4);
    (void) close(s6);
    free(lifc.lifc_buf);
    *ifaddrsp = ifaddrs;
    return (naddr);
fail:
    save_errno = errno;
    (void) close(s4);
    (void) close(s6);
    free(lifc.lifc_buf);
    ifaddrlistx_free(ifaddrs);
    errno = save_errno;
    return (-1);
}

/*
 * Free the provided ifaddrlistx_t.
 */
void
ifaddrlistx_free(ifaddrlistx_t *ifaddrp)
{
    ifaddrlistx_t *next_ifaddrp;

    for (; ifaddrp != NULL; ifaddrp = next_ifaddrp) {
        next_ifaddrp = ifaddrp->ia_next;
        free(ifaddrp);
    }
}