/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 1997
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the Computer Systems
 *      Engineering Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#) $Header: ifaddrlist.c,v 1.2 97/04/22 13:31:05 leres Exp $ (LBL)
 */

#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>

/*
 * See <libinetutil.h> for a description of the programming interface.
 */
int
ifaddrlist(struct ifaddrlist **ipaddrp, int family, uint_t flags, char *errbuf)
{
        struct ifaddrlist       *ifaddrlist = NULL, *al = NULL;
        struct sockaddr_in      *sin;
        struct sockaddr_in6     *sin6;
        struct lifconf          lifc;
        struct lifnum           lifn;
        struct lifreq           *lifrp;
        int                     i, count, nlifr;
        int                     fd;
        const char              *opstr;

        (void) memset(&lifc, 0, sizeof (lifc));
        if (family != AF_INET && family != AF_INET6) {
                (void) strlcpy(errbuf, "invalid address family", ERRBUFSIZE);
                return (-1);
        }

        if ((fd = socket(family, SOCK_DGRAM, 0)) == -1) {
                opstr = "socket";
                goto fail;
        }

        /*
         * Get the number of network interfaces of type `family'.
         */
        lifn.lifn_family = family;
        lifn.lifn_flags = flags;
again:
        if (ioctl(fd, SIOCGLIFNUM, &lifn) == -1) {
                opstr = "SIOCGLIFNUM";
                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 = family;
        lifc.lifc_len = lifn.lifn_count * sizeof (struct lifreq);
        if ((lifc.lifc_buf = realloc(lifc.lifc_buf, lifc.lifc_len)) == NULL) {
                opstr = "realloc";
                goto fail;
        }

        if (ioctl(fd, SIOCGLIFCONF, &lifc) == -1) {
                opstr = "SIOCGLIFCONF";
                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;

        /*
         * Allocate the address list to return.
         */
        if ((ifaddrlist = calloc(nlifr, sizeof (struct ifaddrlist))) == NULL) {
                opstr = "calloc";
                goto fail;
        }

        /*
         * Populate the address list by querying each underlying interface.
         * If a query ioctl returns ENXIO, then the interface must have been
         * removed after the SIOCGLIFCONF completed -- so we just ignore it.
         */
        al = ifaddrlist;
        count = 0;
        for (lifrp = lifc.lifc_req, i = 0; i < nlifr; i++, lifrp++) {
                (void) strlcpy(al->device, lifrp->lifr_name, LIFNAMSIZ);

                if (ioctl(fd, SIOCGLIFFLAGS, lifrp) == -1) {
                        if (errno == ENXIO)
                                continue;
                        opstr = "SIOCGLIFFLAGS";
                        goto fail;
                }
                al->flags = lifrp->lifr_flags;

                if (ioctl(fd, SIOCGLIFINDEX, lifrp) == -1) {
                        if (errno == ENXIO)
                                continue;
                        opstr = "SIOCGLIFINDEX";
                        goto fail;
                }
                al->index = lifrp->lifr_index;

                if (ioctl(fd, SIOCGLIFADDR, lifrp) == -1) {
                        if (errno == ENXIO)
                                continue;
                        opstr = "SIOCGLIFADDR";
                        goto fail;
                }

                if (family == AF_INET) {
                        sin = (struct sockaddr_in *)&lifrp->lifr_addr;
                        al->addr.addr = sin->sin_addr;
                } else {
                        sin6 = (struct sockaddr_in6 *)&lifrp->lifr_addr;
                        al->addr.addr6 = sin6->sin6_addr;
                }
                al++;
                count++;
        }

        (void) close(fd);
        free(lifc.lifc_buf);
        if (count == 0) {
                free(ifaddrlist);
                *ipaddrp = NULL;
                return (0);
        }

        *ipaddrp = ifaddrlist;
        return (count);
fail:
        if (al == NULL) {
                (void) snprintf(errbuf, ERRBUFSIZE, "%s: %s", opstr,
                    strerror(errno));
        } else {
                (void) snprintf(errbuf, ERRBUFSIZE, "%s: %s: %s", opstr,
                    al->device, strerror(errno));
        }
        free(lifc.lifc_buf);
        free(ifaddrlist);
        (void) close(fd);
        return (-1);
}