/*	$OpenBSD: if_gif.c,v 1.31 2003/12/16 20:33:25 markus Exp $	*/
/*	$KAME: if_gif.c,v 1.43 2001/02/20 08:51:07 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/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/syslog.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/bpf.h>

#ifdef	INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_gif.h>
#endif	/* INET */

#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_gif.h>
#endif /* INET6 */

#include <net/if_gif.h>

#include "bpfilter.h"
#include "bridge.h"

extern int ifqmaxlen;

void	gifattach(int);
int	gif_clone_create(struct if_clone *, int);
int	gif_clone_destroy(struct ifnet *);

/*
 * gif global variable definitions
 */
struct gif_softc_head gif_softc_list;
struct if_clone gif_cloner =
    IF_CLONE_INITIALIZER("gif", gif_clone_create, gif_clone_destroy);

/* ARGSUSED */
void
gifattach(count)
	int count;
{
	LIST_INIT(&gif_softc_list);
	if_clone_attach(&gif_cloner);
}

int
gif_clone_create(ifc, unit)
	struct if_clone *ifc;
	int unit;
{
	struct gif_softc *sc;
	int s;

	sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT);
	if (!sc)
		return (ENOMEM);
	bzero(sc, sizeof(*sc));

	snprintf(sc->gif_if.if_xname, sizeof sc->gif_if.if_xname,
	     "%s%d", ifc->ifc_name, unit);
	sc->gif_if.if_mtu    = GIF_MTU;
	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
	sc->gif_if.if_ioctl  = gif_ioctl;
	sc->gif_if.if_start  = gif_start;
	sc->gif_if.if_output = gif_output;
	sc->gif_if.if_type   = IFT_GIF;
	sc->gif_if.if_snd.ifq_maxlen = ifqmaxlen;
	sc->gif_if.if_softc = sc;
	if_attach(&sc->gif_if);
	if_alloc_sadl(&sc->gif_if);

#if NBPFILTER > 0
	bpfattach(&sc->gif_if.if_bpf, &sc->gif_if, DLT_NULL,
		  sizeof(u_int));
#endif
	s = splnet();
	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
	splx(s);

	return (0);
}

int
gif_clone_destroy(ifp)
	struct ifnet *ifp;
{
	struct gif_softc *sc = ifp->if_softc;
	int s;

	s = splnet();
	LIST_REMOVE(sc, gif_list);
	splx(s);

#if NBPFILTER > 0
	bpfdetach(ifp);
#endif
	if_detach(ifp);

	if (sc->gif_psrc)
		free((caddr_t)sc->gif_psrc, M_IFADDR);
	sc->gif_psrc = NULL;
	if (sc->gif_pdst)
		free((caddr_t)sc->gif_pdst, M_IFADDR);
	sc->gif_pdst = NULL;
	free(sc, M_DEVBUF);
	return (0);
}

void
gif_start(ifp)
        struct ifnet *ifp;
{
#if NBRIDGE > 0
        struct sockaddr dst;
#endif /* NBRIDGE */

        struct mbuf *m;
	int s;

#if NBRIDGE > 0
	bzero(&dst, sizeof(dst));

	/*
	 * XXX The assumption here is that only the ethernet bridge
	 * uses the start routine of this interface, and it's thus
	 * safe to do this.
	 */
	dst.sa_family = AF_LINK;
#endif /* NBRIDGE */

	for (;;) {
	        s = splimp();
		IF_DEQUEUE(&ifp->if_snd, m);
		splx(s);

		if (m == NULL) return;

#if NBRIDGE > 0
		/* Sanity check -- interface should be member of a bridge */
		if (ifp->if_bridge == NULL) m_freem(m);
		else gif_output(ifp, m, &dst, NULL);
#else
		m_freem(m);
#endif /* NBRIDGE */
	}
}

int
gif_output(ifp, m, dst, rt)
	struct ifnet *ifp;
	struct mbuf *m;
	struct sockaddr *dst;
	struct rtentry *rt;	/* added in net2 */
{
	struct gif_softc *sc = (struct gif_softc*)ifp;
	int error = 0;
	struct m_tag *mtag;

	if (!(ifp->if_flags & IFF_UP) ||
	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
		m_freem(m);
		error = ENETDOWN;
		goto end;
	}

	/*
	 * gif may cause infinite recursion calls when misconfigured.
	 * We'll prevent this by detecting loops.
	 */
	for (mtag = m_tag_find(m, PACKET_TAG_GIF, NULL); mtag;
	     mtag = m_tag_find(m, PACKET_TAG_GIF, mtag)) {
		if (!bcmp((caddr_t)(mtag + 1), &ifp, sizeof(struct ifnet *))) {
			IF_DROP(&ifp->if_snd);
			log(LOG_NOTICE,
			    "gif_output: recursively called too many times\n");
			m_freem(m);
			error = EIO;	/* is there better errno? */
			goto end;
		}
	}

	mtag = m_tag_get(PACKET_TAG_GIF, sizeof(struct ifnet *), M_NOWAIT);
	if (mtag == NULL) {
		IF_DROP(&ifp->if_snd);
		m_freem(m);
		error = ENOMEM;
		goto end;
	}
	bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *));
	m_tag_prepend(m, mtag);

	m->m_flags &= ~(M_BCAST|M_MCAST);

#if NBPFILTER > 0
	if (ifp->if_bpf) {
		/*
		 * We need to prepend the address family as
		 * a four byte field.  Cons up a dummy header
		 * to pacify bpf.  This is safe because bpf
		 * will only read from the mbuf (i.e., it won't
		 * try to free it or keep a pointer a to it).
		 */
		struct mbuf m0;
		u_int32_t af = dst->sa_family;

		m0.m_flags = 0;
		m0.m_next = m;
		m0.m_len = 4;
		m0.m_data = (char *)&af;
		
		bpf_mtap(ifp->if_bpf, &m0);
	}
#endif
	ifp->if_opackets++;	
	ifp->if_obytes += m->m_pkthdr.len;

	switch (sc->gif_psrc->sa_family) {
#ifdef INET
	case AF_INET:
		error = in_gif_output(ifp, dst->sa_family, m, rt);
		break;
#endif
#ifdef INET6
	case AF_INET6:
		error = in6_gif_output(ifp, dst->sa_family, m, rt);
		break;
#endif
	default:
		m_freem(m);		
		error = ENETDOWN;
		break;
	}

  end:
	if (error)
		ifp->if_oerrors++;
	return error;
}

int
gif_ioctl(ifp, cmd, data)
	struct ifnet *ifp;
	u_long cmd;
	caddr_t data;
{
	struct gif_softc *sc  = (struct gif_softc*)ifp;
	struct ifreq     *ifr = (struct ifreq*)data;
	int error = 0, size;
	struct sockaddr *dst, *src;
	struct sockaddr *sa;
	int s;
	struct gif_softc *sc2;
		
	switch (cmd) {
	case SIOCSIFADDR:
		break;
		
	case SIOCSIFDSTADDR:
		break;

	case SIOCADDMULTI:
	case SIOCDELMULTI:
		switch (ifr->ifr_addr.sa_family) {
#ifdef INET
		case AF_INET:	/* IP supports Multicast */
			break;
#endif /* INET */
#ifdef INET6
		case AF_INET6:	/* IP6 supports Multicast */
			break;
#endif /* INET6 */
		default:  /* Other protocols doesn't support Multicast */
			error = EAFNOSUPPORT;
			break;
		}
		break;

	case SIOCSIFPHYADDR:
#ifdef INET6
	case SIOCSIFPHYADDR_IN6:
#endif /* INET6 */
	case SIOCSLIFPHYADDR:
		switch (cmd) {
#ifdef INET
		case SIOCSIFPHYADDR:
			src = (struct sockaddr *)
				&(((struct in_aliasreq *)data)->ifra_addr);
			dst = (struct sockaddr *)
				&(((struct in_aliasreq *)data)->ifra_dstaddr);
			break;
#endif
#ifdef INET6
		case SIOCSIFPHYADDR_IN6:
			src = (struct sockaddr *)
				&(((struct in6_aliasreq *)data)->ifra_addr);
			dst = (struct sockaddr *)
				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
			break;
#endif
		case SIOCSLIFPHYADDR:
			src = (struct sockaddr *)
				&(((struct if_laddrreq *)data)->addr);
			dst = (struct sockaddr *)
				&(((struct if_laddrreq *)data)->dstaddr);
			break;
		default:
			return EINVAL;
		}

		/* sa_family must be equal */
		if (src->sa_family != dst->sa_family)
			return EINVAL;

		/* validate sa_len */
		switch (src->sa_family) {
#ifdef INET
		case AF_INET:
			if (src->sa_len != sizeof(struct sockaddr_in))
				return EINVAL;
			break;
#endif
#ifdef INET6
		case AF_INET6:
			if (src->sa_len != sizeof(struct sockaddr_in6))
				return EINVAL;
			break;
#endif
		default:
			return EAFNOSUPPORT;
		}
		switch (dst->sa_family) {
#ifdef INET
		case AF_INET:
			if (dst->sa_len != sizeof(struct sockaddr_in))
				return EINVAL;
			break;
#endif
#ifdef INET6
		case AF_INET6:
			if (dst->sa_len != sizeof(struct sockaddr_in6))
				return EINVAL;
			break;
#endif
		default:
			return EAFNOSUPPORT;
		}

		/* check sa_family looks sane for the cmd */
		switch (cmd) {
		case SIOCSIFPHYADDR:
			if (src->sa_family == AF_INET)
				break;
			return EAFNOSUPPORT;
#ifdef INET6
		case SIOCSIFPHYADDR_IN6:
			if (src->sa_family == AF_INET6)
				break;
			return EAFNOSUPPORT;
#endif /* INET6 */
		case SIOCSLIFPHYADDR:
			/* checks done in the above */
			break;
		}

		LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
			if (sc2 == sc)
				continue;
			if (!sc2->gif_pdst || !sc2->gif_psrc)
				continue;
			if (sc2->gif_pdst->sa_family != dst->sa_family ||
			    sc2->gif_pdst->sa_len != dst->sa_len ||
			    sc2->gif_psrc->sa_family != src->sa_family ||
			    sc2->gif_psrc->sa_len != src->sa_len)
				continue;
			/* can't configure same pair of address onto two gifs */
			if (bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
			    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
				error = EADDRNOTAVAIL;
				goto bad;
			}

			/* can't configure multiple multi-dest interfaces */
#define multidest(x) \
	(((struct sockaddr_in *)(x))->sin_addr.s_addr == INADDR_ANY)
#ifdef INET6
#define multidest6(x) \
	(IN6_IS_ADDR_UNSPECIFIED(&((struct sockaddr_in6 *)(x))->sin6_addr))
#endif
			if (dst->sa_family == AF_INET &&
			    multidest(dst) && multidest(sc2->gif_pdst)) {
				error = EADDRNOTAVAIL;
				goto bad;
			}
#ifdef INET6
			if (dst->sa_family == AF_INET6 &&
			    multidest6(dst) && multidest6(sc2->gif_pdst)) {
				error = EADDRNOTAVAIL;
				goto bad;
			}
#endif
		}

		if (sc->gif_psrc)
			free((caddr_t)sc->gif_psrc, M_IFADDR);
		sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
		bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
		sc->gif_psrc = sa;

		if (sc->gif_pdst)
			free((caddr_t)sc->gif_pdst, M_IFADDR);
		sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
		bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
		sc->gif_pdst = sa;

		s = splnet();
		ifp->if_flags |= IFF_RUNNING;
		if_up(ifp);		/* send up RTM_IFINFO */
		splx(s);

		error = 0;
		break;

#ifdef SIOCDIFPHYADDR
	case SIOCDIFPHYADDR:
		if (sc->gif_psrc) {
			free((caddr_t)sc->gif_psrc, M_IFADDR);
			sc->gif_psrc = NULL;
		}
		if (sc->gif_pdst) {
			free((caddr_t)sc->gif_pdst, M_IFADDR);
			sc->gif_pdst = NULL;
		}
		/* change the IFF_{UP, RUNNING} flag as well? */
		break;
#endif
			
	case SIOCGIFPSRCADDR:
#ifdef INET6
	case SIOCGIFPSRCADDR_IN6:
#endif /* INET6 */
		if (sc->gif_psrc == NULL) {
			error = EADDRNOTAVAIL;
			goto bad;
		}
		src = sc->gif_psrc;
		switch (cmd) {
#ifdef INET
		case SIOCGIFPSRCADDR:
			dst = &ifr->ifr_addr;
			size = sizeof(ifr->ifr_addr);
			break;
#endif /* INET */
#ifdef INET6
		case SIOCGIFPSRCADDR_IN6:
			dst = (struct sockaddr *)
				&(((struct in6_ifreq *)data)->ifr_addr);
			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
			break;
#endif /* INET6 */
		default:
			error = EADDRNOTAVAIL;
			goto bad;
		}
		if (src->sa_len > size)
			return EINVAL;
		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
		break;
			
	case SIOCGIFPDSTADDR:
#ifdef INET6
	case SIOCGIFPDSTADDR_IN6:
#endif /* INET6 */
		if (sc->gif_pdst == NULL) {
			error = EADDRNOTAVAIL;
			goto bad;
		}
		src = sc->gif_pdst;
		switch (cmd) {
#ifdef INET
		case SIOCGIFPDSTADDR:
			dst = &ifr->ifr_addr;
			size = sizeof(ifr->ifr_addr);
			break;
#endif /* INET */
#ifdef INET6
		case SIOCGIFPDSTADDR_IN6:
			dst = (struct sockaddr *)
				&(((struct in6_ifreq *)data)->ifr_addr);
			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
			break;
#endif /* INET6 */
		default:
			error = EADDRNOTAVAIL;
			goto bad;
		}
		if (src->sa_len > size)
			return EINVAL;
		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
		break;

	case SIOCGLIFPHYADDR:
		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
			error = EADDRNOTAVAIL;
			goto bad;
		}

		/* copy src */
		src = sc->gif_psrc;
		dst = (struct sockaddr *)
			&(((struct if_laddrreq *)data)->addr);
		size = sizeof(((struct if_laddrreq *)data)->addr);
		if (src->sa_len > size)
			return EINVAL;
		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);

		/* copy dst */
		src = sc->gif_pdst;
		dst = (struct sockaddr *)
			&(((struct if_laddrreq *)data)->dstaddr);
		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
		if (src->sa_len > size)
			return EINVAL;
		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
		break;

	case SIOCSIFFLAGS:
		/* if_ioctl() takes care of it */
		break;

        case SIOCSIFMTU:
                ifp->if_mtu = ((struct ifreq *)data)->ifr_mtu;
                break;

	default:
		error = EINVAL;
		break;
	}
 bad:
	return error;
}