/*	$NetBSD: if.c,v 1.9 2002/05/31 10:22:14 itojun Exp $	*/
/*	$KAME: if.c,v 1.18 2002/05/31 10:10:03 itojun 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.
 */

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

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_ether.h>
#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 __P((const char *));
#ifndef HAVE_GETIFADDRS
static unsigned int if_maxindex __P((void));
#endif
static void get_rtaddrs __P((int, struct sockaddr *, struct sockaddr **));

int
ifinit()
{
	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, __FUNCTION__, "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, __FUNCTION__,
			    "ioctl(SIOCSIFFLAGS): %s", strerror(errno));
		return(-1);
	}

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

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

	if (!(llflag & IN6_IFF_NOTREADY)) {
		warnmsg(LOG_DEBUG, __FUNCTION__, "%s is ready", name);
		return(0);
	} else {
		if (llflag & IN6_IFF_TENTATIVE) {
			warnmsg(LOG_DEBUG, __FUNCTION__, "%s is tentative",
			    name);
			return IFS_TENTATIVE;
		}
		if (llflag & IN6_IFF_DUPLICATED)
			warnmsg(LOG_DEBUG, __FUNCTION__, "%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, __FUNCTION__, "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, __FUNCTION__,
			    "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 ROUNDUP(a, size) \
	(((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a))

#define NEXT_SA(ap) (ap) = (struct sockaddr *) \
	((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\
	sizeof(u_long)) : sizeof(u_long)))
#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, __FUNCTION__,
		    "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, sizeof(mib)/sizeof(mib[0]), &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, __FUNCTION__, "socket(SOCK_DGRAM): %s",
		    strerror(errno));
		exit(1);
	}
	if (getifaddrs(&ifap) != 0) {
		warnmsg(LOG_ERR, __FUNCTION__, "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));
		strncpy(ifr6.ifr_name, name, sizeof(ifr6.ifr_name));
		memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
		if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
			warnmsg(LOG_ERR, __FUNCTION__,
			    "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, __FUNCTION__, "not enough core");
		exit(1);
	}

	if ((s = socket(PF_INET6, SOCK_DGRAM, 0)) < 0) {
		warnmsg(LOG_ERR, __FUNCTION__, "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, __FUNCTION__, "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));
		strncpy(ifr6.ifr_name, name, sizeof(ifr6.ifr_name));
		memcpy(&ifr6.ifr_ifru.ifru_addr, sin6, sin6->sin6_len);
		if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) < 0) {
			warnmsg(LOG_ERR, __FUNCTION__,
			    "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()
{
	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;
			NEXT_SA(sa);
		} else
			rti_info[i] = NULL;
	}
}