/*      $NetBSD: getifaddrs.c,v 1.16 2016/09/21 10:53:24 roy Exp $      */

/*
 * 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
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: getifaddrs.c,v 1.16 2016/09/21 10:53:24 roy Exp $");
#endif /* LIBC_SCCS and not lint */

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

#include <assert.h>
#include <errno.h>
#include <ifaddrs.h>
#include <stdlib.h>
#include <string.h>

#if defined(__weak_alias) && !defined(RUMP_ACTION)
__weak_alias(getifaddrs,_getifaddrs)
__weak_alias(freeifaddrs,_freeifaddrs)
#endif

#ifdef RUMP_ACTION
#include <rump/rump_syscalls.h>
#define sysctl(a,b,c,d,e,f) rump_sys___sysctl(a,b,c,d,e,f)
#endif

#define SA_RLEN(sa)     RT_ROUNDUP((sa)->sa_len)

int
getifaddrs(struct ifaddrs **pif)
{
        size_t icnt = 1;
        size_t dcnt = 0;
        size_t ncnt = 0;
        static const int mib[] = {
                CTL_NET,
                PF_ROUTE,
                0,                      /* protocol */
                0,                      /* wildcard address family */
                NET_RT_IFLIST,
                0                       /* no flags */
        };
        size_t needed;
        char *buf;
        char *next;
        struct ifaddrs cif;
        char *p, *p0;
        struct rt_msghdr *rtm;
        struct if_msghdr *ifm;
        struct ifa_msghdr *ifam;
        struct sockaddr *sa;
        struct ifaddrs *ifa, *ift;
        u_short idx = 0;
        int i;
        size_t len, alen;
        char *data;
        char *names;

        _DIAGASSERT(pif != NULL);

        if (sysctl(mib, (u_int)__arraycount(mib), NULL, &needed, NULL, 0) < 0)
                return (-1);
        if ((buf = malloc(needed)) == NULL)
                return (-1);
        if (sysctl(mib, (u_int)__arraycount(mib), buf, &needed, NULL, 0) < 0) {
                free(buf);
                return (-1);
        }

        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_msghdr *)(void *)rtm;
                        if (ifm->ifm_addrs & RTA_IFP) {
                                const struct sockaddr_dl *dl;

                                idx = ifm->ifm_index;
                                ++icnt;
                                dl = (struct sockaddr_dl *)(void *)(ifm + 1);
                                dcnt += SA_RLEN((const struct sockaddr *)(const void *)dl) +
                                    ALIGNBYTES;
                                dcnt += sizeof(ifm->ifm_data);
                                ncnt += dl->sdl_nlen + 1;
                        } else
                                idx = 0;
                        break;

                case RTM_NEWADDR:
                        ifam = (struct ifa_msghdr *)(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 *)(void *)(ifam + 1);
                        ++icnt;
                        /* 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->sa_len == 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;
        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_msghdr *)(void *)rtm;
                        if (ifm->ifm_addrs & RTA_IFP) {
                                const struct sockaddr_dl *dl;

                                idx = ifm->ifm_index;
                                dl = (struct sockaddr_dl *)(void *)(ifm + 1);

                                memset(&cif, 0, sizeof(cif));

                                cif.ifa_name = names;
                                cif.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;

                                cif.ifa_addr = (struct sockaddr *)(void *)data;
                                memcpy(data, dl, (size_t)dl->sdl_len);
                                data += SA_RLEN((const struct sockaddr *)(const void *)dl);

                                /* ifm_data needs to be aligned */
                                cif.ifa_data = data = (void *)ALIGN(data);
                                memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
                                data += sizeof(ifm->ifm_data);
                        } else
                                idx = 0;
                        break;

                case RTM_NEWADDR:
                        ifam = (struct ifa_msghdr *)(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;
                        ift->ifa_addrflags = ifam->ifam_addrflags;
                        p = (char *)(void *)(ifam + 1);
                        /* 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;
                                        if (ift->ifa_addr->sa_family == AF_LINK)
                                                ift->ifa_data = cif.ifa_data;
                                        break;

                                case RTAX_NETMASK:
                                        ift->ifa_netmask =
                                            (struct sockaddr *)(void *)data;
                                        if (sa->sa_len == 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;
                        }


                        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)
{

        _DIAGASSERT(ifp != NULL);

        free(ifp);
}