/*      $KAME: if.c,v 1.15 2001/05/22 06:04:17 jinmei Exp $     */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
 *
 * $FreeBSD: src/usr.sbin/rtsold/if.c,v 1.2.2.3 2001/07/03 11:02:16 ume Exp $
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>
#include <sys/queue.h>

#include <net/if.h>
#if defined(__DragonFly__) 
#include <net/if_var.h>
#endif /* __DragonFly__ >= 3 */
#include <net/if_types.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#ifdef __DragonFly__
# include <net/ethernet.h>
#endif
#ifdef __NetBSD__
#include <net/if_ether.h>
#endif
#if defined(__bsdi__) || defined(__OpenBSD__)
# include <netinet/in.h>
# include <netinet/if_ether.h>
#endif
#include <netinet/in.h>
#include <netinet/icmp6.h>

#include <netinet6/in6_var.h>

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <syslog.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <limits.h>
#ifdef HAVE_GETIFADDRS
#include <ifaddrs.h>
#endif

#include "rtsold.h"

extern int rssock;
static int ifsock;

static int get_llflag(const char *name);
#ifndef HAVE_GETIFADDRS
static unsigned int if_maxindex(void);
#endif
static void get_rtaddrs(int addrs, struct sockaddr *sa,
                             struct sockaddr **rti_info);

int
ifinit(void)
{
        ifsock = rssock;

        return(0);
}

int
interface_up(char *name)
{
        struct ifreq ifr;
        int llflag;

        strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));

        if (ioctl(ifsock, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
                warnmsg(LOG_WARNING, __func__, "ioctl(SIOCGIFFLAGS): %s",
                       strerror(errno));
                return(-1);
        }
        if (!(ifr.ifr_flags & IFF_UP)) {
                ifr.ifr_flags |= IFF_UP;
                if (ioctl(ifsock, SIOCSIFFLAGS, (caddr_t)&ifr) < 0) {
                        warnmsg(LOG_ERR, __func__,
                                "ioctl(SIOCSIFFLAGS): %s", strerror(errno));
                }
                return(-1);
        }

        warnmsg(LOG_DEBUG, __func__, "checking if %s is ready...", name);

        llflag = get_llflag(name);
        if (llflag < 0) {
                warnmsg(LOG_WARNING, __func__,
                        "get_llflag() failed, anyway I'll try");
                return 0;
        }

        if (!(llflag & IN6_IFF_NOTREADY)) {
                warnmsg(LOG_DEBUG, __func__,
                        "%s is ready", name);
                return(0);
        } else {
                if (llflag & IN6_IFF_TENTATIVE) {
                        warnmsg(LOG_DEBUG, __func__, "%s is tentative",
                               name);
                        return IFS_TENTATIVE;
                }
                if (llflag & IN6_IFF_DUPLICATED)
                        warnmsg(LOG_DEBUG, __func__, "%s is duplicated",
                               name);
                return -1;
        }
}

int
interface_status(struct ifinfo *ifinfo)
{
        char *ifname = ifinfo->ifname;
        struct ifreq ifr;
        struct ifmediareq ifmr;
        
        /* get interface flags */
        memset(&ifr, 0, sizeof(ifr));
        strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
        if (ioctl(ifsock, SIOCGIFFLAGS, &ifr) < 0) {
                warnmsg(LOG_ERR, __func__, "ioctl(SIOCGIFFLAGS) on %s: %s",
                       ifname, strerror(errno));
                return(-1);
        }
        /*
         * if one of UP and RUNNING flags is dropped,
         * the interface is not active.
         */
        if ((ifr.ifr_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
                goto inactive;
        }

        /* Next, check carrier on the interface, if possible */
        if (!ifinfo->mediareqok)
                goto active;
        memset(&ifmr, 0, sizeof(ifmr));
        strncpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));

        if (ioctl(ifsock, SIOCGIFMEDIA, (caddr_t)&ifmr) < 0) {
                if (errno != EINVAL) {
                        warnmsg(LOG_DEBUG, __func__,
                                "ioctl(SIOCGIFMEDIA) on %s: %s",
                               ifname, strerror(errno));
                        return(-1);
                }
                /*
                 * EINVAL simply means that the interface does not support
                 * the SIOCGIFMEDIA ioctl. We regard it alive.
                 */
                ifinfo->mediareqok = 0;
                goto active;
        }

        if (ifmr.ifm_status & IFM_AVALID) {
                switch(ifmr.ifm_active & IFM_NMASK) {
                 case IFM_ETHER:
                         if (ifmr.ifm_status & IFM_ACTIVE)
                                 goto active;
                         else
                                 goto inactive;
                         break;
                 default:
                         goto inactive;
                }
        }

  inactive:
        return(0);

  active:
        return(1);
}

#define ROUNDUP8(a) (1 + (((a) - 1) | 7))

int
lladdropt_length(struct sockaddr_dl *sdl)
{
        switch(sdl->sdl_type) {
         case IFT_ETHER:
#ifdef IFT_IEEE80211
        case IFT_IEEE80211:
#endif
                 return(ROUNDUP8(ETHER_ADDR_LEN + 2));
         default:
                 return(0);
        }
}

void
lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt)
{
        char *addr;

        ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */

        switch(sdl->sdl_type) {
         case IFT_ETHER:
#ifdef IFT_IEEE80211
        case IFT_IEEE80211:
#endif
                 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3;
                 addr = (char *)(ndopt + 1);
                 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN);
                 break;
         default:
                 warnmsg(LOG_ERR, __func__,
                         "unsupported link type(%d)", sdl->sdl_type);
                 exit(1);
        }

        return;
}

struct sockaddr_dl *
if_nametosdl(char *name)
{
        int mib[6] = {CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0};
        char *buf, *next, *lim;
        size_t len;
        struct if_msghdr *ifm;
        struct sockaddr *sa, *rti_info[RTAX_MAX];
        struct sockaddr_dl *sdl = NULL, *ret_sdl;

        if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
                return(NULL);
        if ((buf = malloc(len)) == NULL)
                return(NULL);
        if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
                free(buf);
                return(NULL);
        }

        lim = buf + len;
        for (next = buf; next < lim; next += ifm->ifm_msglen) {
                ifm = (struct if_msghdr *)next;
                if (ifm->ifm_type == RTM_IFINFO) {
                        sa = (struct sockaddr *)(ifm + 1);
                        get_rtaddrs(ifm->ifm_addrs, sa, rti_info);
                        if ((sa = rti_info[RTAX_IFP]) != NULL) {
                                if (sa->sa_family == AF_LINK) {
                                        sdl = (struct sockaddr_dl *)sa;
                                        if (strlen(name) != sdl->sdl_nlen)
                                                continue; /* not same len */
                                        if (strncmp(&sdl->sdl_data[0],
                                                    name,
                                                    sdl->sdl_nlen) == 0) {
                                                break;
                                        }
                                }
                        }
                }
        }
        if (next == lim) {
                /* search failed */
                free(buf);
                return(NULL);
        }

        if ((ret_sdl = malloc(sdl->sdl_len)) == NULL)
                return(NULL);
        memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len);

        free(buf);
        return(ret_sdl);
}

int
getinet6sysctl(int code)
{
        int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, 0 };
        int value;
        size_t size;

        mib[3] = code;
        size = sizeof(value);
        if (sysctl(mib, NELEM(mib), &value, &size, NULL, 0) < 0)
                return -1;
        else
                return value;
}

/*------------------------------------------------------------*/

/* get ia6_flags for link-local addr on if.  returns -1 on error. */
static int
get_llflag(const char *name)
{
#ifdef HAVE_GETIFADDRS
        struct ifaddrs *ifap, *ifa;
        struct in6_ifreq ifr6;
        struct sockaddr_in6 *sin6;
        int s;

        if ((s = socket(PF_INET6, SOCK_DGRAM, 0)) < 0) {
                warnmsg(LOG_ERR, __func__, "socket(SOCK_DGRAM): %s",
                    strerror(errno));
                exit(1);
        }
        if (getifaddrs(&ifap) != 0) {
                warnmsg(LOG_ERR, __func__, "etifaddrs: %s",
                    strerror(errno));
                exit(1);
        }

        for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
                if (strlen(ifa->ifa_name) != strlen(name)
                 || strncmp(ifa->ifa_name, name, strlen(name)) != 0)
                        continue;
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
                if (!IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
                        continue;

                memset(&ifr6, 0, sizeof(ifr6));
                strcpy(ifr6.ifr_name, name);
                memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
                if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
                        warnmsg(LOG_ERR, __func__,
                            "ioctl(SIOCGIFAFLAG_IN6): %s", strerror(errno));
                        exit(1);
                }

                freeifaddrs(ifap);
                close(s);
                return ifr6.ifr_ifru.ifru_flags6;
        }

        freeifaddrs(ifap);
        close(s);
        return -1;
#else
        int s;
        unsigned int maxif;
        struct ifreq *iflist;
        struct ifconf ifconf;
        struct ifreq *ifr, *ifr_end;
        struct sockaddr_in6 *sin6;
        struct in6_ifreq ifr6;

        maxif = if_maxindex() + 1;
        iflist = (struct ifreq *)malloc(maxif * BUFSIZ);        /* XXX */
        if (iflist == NULL) {
                warnmsg(LOG_ERR, __func__, "not enough core");
                exit(1);
        }

        if ((s = socket(PF_INET6, SOCK_DGRAM, 0)) < 0) {
                warnmsg(LOG_ERR, __func__, "socket(SOCK_DGRAM): %s",
                    strerror(errno));
                exit(1);
        }
        memset(&ifconf, 0, sizeof(ifconf));
        ifconf.ifc_req = iflist;
        ifconf.ifc_len = maxif * BUFSIZ;        /* XXX */
        if (ioctl(s, SIOCGIFCONF, &ifconf) < 0) {
                warnmsg(LOG_ERR, __func__, "ioctl(SIOCGIFCONF): %s",
                    strerror(errno));
                exit(1);
        }

        /* Look for this interface in the list */
        ifr_end = (struct ifreq *) (ifconf.ifc_buf + ifconf.ifc_len);
        for (ifr = ifconf.ifc_req;
             ifr < ifr_end;
             ifr = (struct ifreq *) ((char *) &ifr->ifr_addr
                                    + ifr->ifr_addr.sa_len)) {
                if (strlen(ifr->ifr_name) != strlen(name)
                 || strncmp(ifr->ifr_name, name, strlen(name)) != 0)
                        continue;
                if (ifr->ifr_addr.sa_family != AF_INET6)
                        continue;
                sin6 = (struct sockaddr_in6 *)&ifr->ifr_addr;
                if (!IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
                        continue;

                memset(&ifr6, 0, sizeof(ifr6));
                strcpy(ifr6.ifr_name, name);
                memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
                if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
                        warnmsg(LOG_ERR, __func__,
                            "ioctl(SIOCGIFAFLAG_IN6): %s", strerror(errno));
                        exit(1);
                }

                free(iflist);
                close(s);
                return ifr6.ifr_ifru.ifru_flags6;
        }

        free(iflist);
        close(s);
        return -1;
#endif
}

#ifndef HAVE_GETIFADDRS
static unsigned int
if_maxindex(void)
{
        struct if_nameindex *p, *p0;
        unsigned int max = 0;

        p0 = if_nameindex();
        for (p = p0; p && p->if_index && p->if_name; p++) {
                if (max < p->if_index)
                        max = p->if_index;
        }
        if_freenameindex(p0);
        return max;
}
#endif

static void
get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
{
        int i;
        
        for (i = 0; i < RTAX_MAX; i++) {
                if (addrs & (1 << i)) {
                        rti_info[i] = sa;
                        RT_ADVANCE(sa, sa);
                }
                else
                        rti_info[i] = NULL;
        }
}