/*      $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 itojun Exp $      */

/*-
 * SPDX-License-Identifier: BSD-1-Clause
 *
 * Copyright (c) 1995, 1999
 *      Berkeley Software Design, Inc.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``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 Berkeley Software Design, Inc. 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.
 *
 *      BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp
 */
/*
 * NOTE: SIOCGIFCONF case is not LP64 friendly.  it also does not perform
 * try-and-error for region size.
 */

#include "namespace.h"
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#ifdef  NET_RT_IFLIST
#include <sys/param.h>
#include <net/route.h>
#include <sys/sysctl.h>
#include <net/if_dl.h>
#endif

#include <errno.h>
#include <ifaddrs.h>
#include <stdlib.h>
#include <string.h>
#include "un-namespace.h"

#if !defined(AF_LINK)
#define SA_LEN(sa)      sizeof(struct sockaddr)
#endif

#if !defined(SA_LEN)
#define SA_LEN(sa)      (sa)->sa_len
#endif

#define SALIGN  (sizeof(long) - 1)
#define SA_RLEN(sa)     ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1))

#ifndef ALIGNBYTES
/*
 * On systems with a routing socket, ALIGNBYTES should match the value
 * that the kernel uses when building the messages.
 */
#define ALIGNBYTES      XXX
#endif
#ifndef ALIGN
#define ALIGN(p)        (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
#endif

#define MAX_SYSCTL_TRY 5

int
getifaddrs(struct ifaddrs **pif)
{
        int icnt = 1;
        int dcnt = 0;
        int ncnt = 0;
        int ntry = 0;
        int mib[6];
        size_t needed;
        char *buf;
        char *next;
        struct ifaddrs *cif;
        char *p, *p0;
        struct rt_msghdr *rtm;
        struct if_msghdrl *ifm;
        struct ifa_msghdrl *ifam;
        struct sockaddr_dl *dl;
        struct sockaddr *sa;
        struct ifaddrs *ifa, *ift;
        struct if_data *if_data;
        u_short idx = 0;
        int i;
        size_t len, alen;
        char *data;
        char *names;

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;             /* protocol */
        mib[3] = 0;             /* wildcard address family */
        mib[4] = NET_RT_IFLISTL;/* extra fields for extensible msghdr structs */
        mib[5] = 0;             /* no flags */
        do {
                /*
                 * We'll try to get addresses several times in case that
                 * the number of addresses is unexpectedly increased during
                 * the two sysctl calls.  This should rarely happen, but we'll
                 * try to do our best for applications that assume success of
                 * this library (which should usually be the case).
                 * Portability note: since FreeBSD does not add margin of
                 * memory at the first sysctl, the possibility of failure on
                 * the second sysctl call is a bit higher.
                 */

                if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
                        return (-1);
                if ((buf = malloc(needed)) == NULL)
                        return (-1);
                if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
                        if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
                                free(buf);
                                return (-1);
                        }
                        free(buf);
                        buf = NULL;
                } 
        } while (buf == NULL);

        for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
                rtm = (struct rt_msghdr *)(void *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
                switch (rtm->rtm_type) {
                case RTM_IFINFO:
                        ifm = (struct if_msghdrl *)(void *)rtm;
                        if (ifm->ifm_addrs & RTA_IFP) {
                                idx = ifm->ifm_index;
                                ++icnt;
                                if_data = IF_MSGHDRL_IFM_DATA(ifm);
                                dcnt += if_data->ifi_datalen;
                                dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm);
                                dcnt += SA_RLEN((struct sockaddr *)(void*)dl) +
                                    ALIGNBYTES;
                                ncnt += dl->sdl_nlen + 1;
                        } else
                                idx = 0;
                        break;

                case RTM_NEWADDR:
                        ifam = (struct ifa_msghdrl *)(void *)rtm;
                        if (idx && ifam->ifam_index != idx)
                                abort();        /* this cannot happen */

#define RTA_MASKS       (RTA_NETMASK | RTA_IFA | RTA_BRD)
                        if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
                                break;
                        p = (char *)IFA_MSGHDRL_RTA(ifam);
                        ++icnt;
                        if_data = IFA_MSGHDRL_IFAM_DATA(ifam);
                        dcnt += if_data->ifi_datalen + ALIGNBYTES;

                        /* Scan to look for length of address */
                        alen = 0;
                        for (p0 = p, i = 0; i < RTAX_MAX; i++) {
                                if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
                                    == 0)
                                        continue;
                                sa = (struct sockaddr *)(void *)p;
                                len = SA_RLEN(sa);
                                if (i == RTAX_IFA) {
                                        alen = len;
                                        break;
                                }
                                p += len;
                        }
                        for (p = p0, i = 0; i < RTAX_MAX; i++) {
                                if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
                                    == 0)
                                        continue;
                                sa = (struct sockaddr *)(void *)p;
                                len = SA_RLEN(sa);
                                if (i == RTAX_NETMASK && SA_LEN(sa) == 0)
                                        dcnt += alen;
                                else
                                        dcnt += len;
                                p += len;
                        }
                        break;
                }
        }

        if (icnt + dcnt + ncnt == 1) {
                *pif = NULL;
                free(buf);
                return (0);
        }
        data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
        if (data == NULL) {
                free(buf);
                return(-1);
        }

        ifa = (struct ifaddrs *)(void *)data;
        data += sizeof(struct ifaddrs) * icnt;
        names = data + dcnt;

        memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
        ift = ifa;

        idx = 0;
        cif = NULL;
        for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
                rtm = (struct rt_msghdr *)(void *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
                switch (rtm->rtm_type) {
                case RTM_IFINFO:
                        ifm = (struct if_msghdrl *)(void *)rtm;
                        if ((ifm->ifm_addrs & RTA_IFP) == 0) {
                                idx = 0;
                                break;
                        }

                        idx = ifm->ifm_index;
                        dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm);

                        cif = ift;
                        ift->ifa_name = names;
                        ift->ifa_flags = (int)ifm->ifm_flags;
                        memcpy(names, dl->sdl_data, (size_t)dl->sdl_nlen);
                        names[dl->sdl_nlen] = 0;
                        names += dl->sdl_nlen + 1;

                        ift->ifa_addr = (struct sockaddr *)(void *)data;
                        memcpy(data, dl, (size_t)SA_LEN((struct sockaddr *)
                            (void *)dl));
                        data += SA_RLEN((struct sockaddr *)(void *)dl);

                        if_data = IF_MSGHDRL_IFM_DATA(ifm);
                        /* ifm_data needs to be aligned */
                        ift->ifa_data = data = (void *)ALIGN(data);
                        memcpy(data, if_data, if_data->ifi_datalen);
                        data += if_data->ifi_datalen;

                        ift = (ift->ifa_next = ift + 1);
                        break;

                case RTM_NEWADDR:
                        ifam = (struct ifa_msghdrl *)(void *)rtm;
                        if (idx && ifam->ifam_index != idx)
                                abort();        /* this cannot happen */

                        if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
                                break;
                        ift->ifa_name = cif->ifa_name;
                        ift->ifa_flags = cif->ifa_flags;
                        ift->ifa_data = NULL;

                        p = (char *)IFA_MSGHDRL_RTA(ifam);
                        /* Scan to look for length of address */
                        alen = 0;
                        for (p0 = p, i = 0; i < RTAX_MAX; i++) {
                                if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
                                    == 0)
                                        continue;
                                sa = (struct sockaddr *)(void *)p;
                                len = SA_RLEN(sa);
                                if (i == RTAX_IFA) {
                                        alen = len;
                                        break;
                                }
                                p += len;
                        }
                        for (p = p0, i = 0; i < RTAX_MAX; i++) {
                                if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
                                    == 0)
                                        continue;
                                sa = (struct sockaddr *)(void *)p;
                                len = SA_RLEN(sa);
                                switch (i) {
                                case RTAX_IFA:
                                        ift->ifa_addr =
                                            (struct sockaddr *)(void *)data;
                                        memcpy(data, p, len);
                                        data += len;
                                        break;

                                case RTAX_NETMASK:
                                        ift->ifa_netmask =
                                            (struct sockaddr *)(void *)data;
                                        if (SA_LEN(sa) == 0) {
                                                memset(data, 0, alen);
                                                data += alen;
                                                break;
                                        }
                                        memcpy(data, p, len);
                                        data += len;
                                        break;

                                case RTAX_BRD:
                                        ift->ifa_broadaddr =
                                            (struct sockaddr *)(void *)data;
                                        memcpy(data, p, len);
                                        data += len;
                                        break;
                                }
                                p += len;
                        }

                        if_data = IFA_MSGHDRL_IFAM_DATA(ifam);
                        /* ifam_data needs to be aligned */
                        ift->ifa_data = data = (void *)ALIGN(data);
                        memcpy(data, if_data, if_data->ifi_datalen);
                        data += if_data->ifi_datalen;

                        ift = (ift->ifa_next = ift + 1);
                        break;
                }
        }

        free(buf);

        if (--ift >= ifa) {
                ift->ifa_next = NULL;
                *pif = ifa;
        } else {
                *pif = NULL;
                free(ifa);
        }
        return (0);
}

void
freeifaddrs(struct ifaddrs *ifp)
{

        free(ifp);
}