NetBSD/sys/netiso/iso_snpac.c

/*	$NetBSD: iso_snpac.c,v 1.33 2005/05/31 01:37:06 christos Exp $	*/

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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.
 *
 *	@(#)iso_snpac.c	8.4 (Berkeley) 5/2/95
 */

/***********************************************************
		Copyright IBM Corporation 1987

                      All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of IBM not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission.

IBM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
IBM BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.

******************************************************************/

/*
 * ARGO Project, Computer Sciences Dept., University of Wisconsin - Madison
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: iso_snpac.c,v 1.33 2005/05/31 01:37:06 christos Exp $");

#include "opt_iso.h"
#ifdef ISO

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/proc.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>

#include <net/if_ether.h>

#include <netinet/in.h>

#include <netiso/iso.h>
#include <netiso/iso_var.h>
#include <netiso/iso_snpac.h>
#include <netiso/clnp.h>
#include <netiso/clnp_stat.h>
#include <netiso/esis.h>
#include <netiso/argo_debug.h>

int             iso_systype = SNPA_ES;	/* default to be an ES */

LIST_HEAD(, llinfo_llc) llinfo_llc;

struct callout snpac_age_ch;

struct sockaddr_iso blank_siso = {sizeof(blank_siso), AF_ISO};
static struct sockaddr_iso
	dst = {sizeof(dst), AF_ISO},
	gte = {sizeof(gte), AF_ISO},
#if 0
	src = {sizeof(src), AF_ISO},
#endif
	msk = {sizeof(msk), AF_ISO},
	zmk = {0, 0};

#define zsi blank_siso
#define zero_isoa	zsi.siso_addr
#define zap_isoaddr(a, b) {Bzero(&a.siso_addr, sizeof(*r)); r = b; \
	   Bcopy(r, &a.siso_addr, 1 + (r)->isoa_len);}
#define S(x) ((struct sockaddr *)&(x))

static struct sockaddr_dl blank_dl = {sizeof(blank_dl), AF_LINK};
static struct sockaddr_dl gte_dl;
#define zap_linkaddr(a, b, c, i) \
	(*a = blank_dl, memcpy(a->sdl_data, b, a->sdl_alen = c), a->sdl_index = i)

static void snpac_fixdstandmask (int);

/*
 *	We only keep track of a single IS at a time.
 */
struct rtentry *known_is;

/*
 *	Addresses taken from NBS agreements, December 1987.
 *
 *	These addresses assume on-the-wire transmission of least significant
 *	bit first. This is the method used by 802.3. When these
 *	addresses are passed to the token ring driver, (802.5), they
 *	must be bit-swapped because 802.5 transmission order is MSb first.
 *
 *	Furthermore, according to IBM Austin, these addresses are not
 *	true token ring multicast addresses. More work is necessary
 *	to get multicast to work right on token ring.
 *
 *	Currently, the token ring driver does not handle multicast, so
 *	these addresses are converted into the broadcast address in
 *	lan_output() That means that if these multicast addresses change
 *	the token ring driver must be altered.
 */
const char all_es_snpa[] = {0x09, 0x00, 0x2b, 0x00, 0x00, 0x04};
const char all_is_snpa[] = {0x09, 0x00, 0x2b, 0x00, 0x00, 0x05};
const char all_l1is_snpa[] = {0x01, 0x80, 0xc2, 0x00, 0x00, 0x14};
const char all_l2is_snpa[] = {0x01, 0x80, 0xc2, 0x00, 0x00, 0x15};

union sockunion {
	struct sockaddr_iso siso;
	struct sockaddr_dl sdl;
	struct sockaddr sa;
};

/*
 * FUNCTION:		llc_rtrequest
 *
 * PURPOSE:		Manage routing table entries specific to LLC for ISO.
 *
 * NOTES:		This does a lot of obscure magic;
 */
void
llc_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
{
	union sockunion *gate = (union sockunion *) rt->rt_gateway;
	struct llinfo_llc *lc = (struct llinfo_llc *) rt->rt_llinfo;
	struct ifnet   *ifp = rt->rt_ifp;
	int             addrlen = ifp->if_addrlen;
#define LLC_SIZE 3		/* XXXXXX do this right later */

#ifdef ARGO_DEBUG
	if (argo_debug[D_SNPA]) {
		printf("llc_rtrequest(%d, %p, %p)\n", req, rt, info);
	}
#endif
	if (rt->rt_flags & RTF_GATEWAY)
		return;
	else
		switch (req) {
		case RTM_ADD:
			/*
			 * Case 1: This route may come from a route to iface with mask
			 * or from a default route.
			 */
			if (rt->rt_flags & RTF_CLONING) {
				iso_setmcasts(ifp, req);
				rt_setgate(rt, rt_key(rt),
					   (struct sockaddr *) & blank_dl);
				return;
			}
			if (lc != 0)
				return;	/* happens on a route change */
			/* FALLTHROUGH */
		case RTM_RESOLVE:
			/*
			 * Case 2:  This route may come from cloning, or a manual route
			 * add with a LL address.
			 */
			if (gate->sdl.sdl_family != AF_LINK) {
				log(LOG_DEBUG, "llc_rtrequest: got non-link non-gateway route\n");
				break;
			}
			R_Malloc(lc, struct llinfo_llc *, sizeof(*lc));
			rt->rt_llinfo = (caddr_t) lc;
			if (lc == 0) {
				log(LOG_DEBUG, "llc_rtrequest: malloc failed\n");
				break;
			}
			Bzero(lc, sizeof(*lc));
			lc->lc_rt = rt;
			rt->rt_flags |= RTF_LLINFO;
			LIST_INSERT_HEAD(&llinfo_llc, lc, lc_list);
			if (gate->sdl.sdl_alen == sizeof(struct esis_req)
			    + addrlen) {
				gate->sdl.sdl_alen -= sizeof(struct esis_req);
				(void)memcpy(&lc->lc_er,
				    (const char *)CLLADDR(&gate->sdl) +
				    addrlen, sizeof(lc->lc_er));
			} else if (gate->sdl.sdl_alen == addrlen)
				lc->lc_flags = (SNPA_ES | SNPA_VALID | SNPA_PERM);
			break;
		case RTM_DELETE:
			if (rt->rt_flags & RTF_CLONING)
				iso_setmcasts(ifp, req);
			if (lc == 0)
				return;
			LIST_REMOVE(lc, lc_list);
			Free(lc);
			rt->rt_llinfo = 0;
			rt->rt_flags &= ~RTF_LLINFO;
			break;
		}
	if (rt->rt_rmx.rmx_mtu == 0) {
		rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu - LLC_SIZE;
	}
}

/*
 * FUNCTION:		iso_setmcasts
 *
 * PURPOSE:		Enable/Disable ESIS/ISIS multicast reception on
 *			interfaces.
 *
 * NOTES:		This also does a lot of obscure magic;
 */
void
iso_setmcasts(struct ifnet *ifp, int req)
{
	static const char * const addrlist[] =
	{all_es_snpa, all_is_snpa, all_l1is_snpa, all_l2is_snpa, 0};
	struct ifreq ifr;
	const char *const *cpp;

	(void)memset(&ifr, 0, sizeof(ifr));
	for (cpp = addrlist; *cpp; cpp++) {
		(void)memcpy(ifr.ifr_addr.sa_data, *cpp, 6);
		if (req == RTM_ADD && (ifp->if_ioctl == 0 ||
		    (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (caddr_t)&ifr) != 0))
			printf("iso_setmcasts: %s unable to add mcast\n",
			    ifp->if_xname);
		else if (req == RTM_DELETE && (ifp->if_ioctl == 0 ||
		    (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)&ifr) != 0))
			printf("iso_setmcasts: %s unable to delete mcast\n",
			    ifp->if_xname);
	}
}

/*
 * FUNCTION:		iso_snparesolve
 *
 * PURPOSE:		Resolve an iso address into snpa address
 *
 * RETURNS:		0 if addr is resolved
 *			errno if addr is unknown
 *
 * SIDE EFFECTS:
 *
 * NOTES:		Now that we have folded the snpa cache into the routing
 *			table, we know there is no snpa address known for this
 *			destination.  If we know of a default IS, then the
 *			address of the IS is returned.  If no IS is known,
 *			then return the multi-cast address for "all ES" for
 *			this interface.
 *
 *			NB: the last case described above constitutes the
 *			query configuration function 9542, sec 6.5
 *			A mechanism is needed to prevent this function from
 *			being invoked if the system is an IS.
 */
int
iso_snparesolve(
	struct ifnet   *ifp,		/* outgoing interface */
	struct sockaddr_iso *dest,	/* destination */
	caddr_t         snpa,		/* RESULT: snpa to be used */
	int            *snpa_len)	/* RESULT: length of snpa */
{
	struct llinfo_llc *sc;	/* ptr to snpa table entry */
	const char *found_snpa;
	int             addrlen;

	/*
	 * This hack allows us to send esis packets that have the destination
	 * snpa addresss embedded in the destination nsap address
	 */
	if (dest->siso_data[0] == AFI_SNA) {
		/*
		 *	This is a subnetwork address. Return it immediately
		 */
#ifdef ARGO_DEBUG
		if (argo_debug[D_SNPA]) {
			printf("iso_snparesolve: return SN address\n");
		}
#endif
		addrlen = dest->siso_nlen - 1;	/* subtract size of AFI */
		found_snpa = (const char *)dest->siso_data + 1;
		/*
		 * If we are an IS, we can't do much with the packet; Check
		 * if we know about an IS.
		 */
	} else if (iso_systype != SNPA_IS && known_is != 0 &&
		   (sc = (struct llinfo_llc *) known_is->rt_llinfo) &&
		   (sc->lc_flags & SNPA_VALID)) {
		struct sockaddr_dl *sdl =
		(struct sockaddr_dl *) (known_is->rt_gateway);
		found_snpa = LLADDR(sdl);
		addrlen = sdl->sdl_alen;
	} else if (ifp->if_flags & IFF_BROADCAST) {
		/*
		 * no IS, no match. Return "all es" multicast address for
		 * this interface, as per Query Configuration Function (9542
		 * sec 6.5)
		 *
		 * Note: there is a potential problem here. If the destination
		 * is on the subnet and it does not respond with a ESH, but
		 * does send back a TP CC, a connection could be established
		 * where we always transmit the CLNP packet to "all es"
		 */
		addrlen = ifp->if_addrlen;
		found_snpa = (const char *) all_es_snpa;
	} else
		return (ENETUNREACH);
	memcpy(snpa, found_snpa, *snpa_len = addrlen);
	return (0);
}


/*
 * FUNCTION:		snpac_free
 *
 * PURPOSE:		free an entry in the iso address map table
 *
 * RETURNS:		nothing
 *
 * SIDE EFFECTS:
 *
 * NOTES:		If there is a route entry associated with cache
 *			entry, then delete that as well
 */
void
snpac_free(
	struct llinfo_llc *lc)	/* entry to free */
{
	struct rtentry *rt = lc->lc_rt;

	if (known_is == rt)
		known_is = 0;
	if (rt && (rt->rt_flags & RTF_UP) &&
	    (rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED))) {
		RTFREE(rt);
		rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, rt_mask(rt),
			  rt->rt_flags, (struct rtentry **) 0);
		RTFREE(rt);
	}
}

/*
 * FUNCTION:		snpac_add
 *
 * PURPOSE:		Add an entry to the snpa cache
 *
 * RETURNS:
 *
 * SIDE EFFECTS:
 *
 * NOTES:		If entry already exists, then update holding time.
 */
int
snpac_add(
	struct ifnet   *ifp,		/* interface info is related to */
	struct iso_addr *nsap,		/* nsap to add */
	caddr_t         snpa,		/* translation */
	int             type,		/* SNPA_IS or SNPA_ES */
	u_short         ht,		/* holding time (in seconds) */
	int             nsellength)	/* nsaps may differ only in trailing
					 * bytes */
{
	struct llinfo_llc *lc;
	struct rtentry *rt;
	struct rtentry *mrt = 0;
	struct iso_addr *r;	/* for zap_isoaddr macro */
	int             snpalen = min(ifp->if_addrlen, MAX_SNPALEN);
	int             new_entry = 0, index = ifp->if_index, iftype = ifp->if_type;

#ifdef ARGO_DEBUG
	if (argo_debug[D_SNPA]) {
		printf("snpac_add(%p, %p, %p, %x, %x, %x)\n",
		    ifp, nsap, snpa, type, ht, nsellength);
	}
#endif
	zap_isoaddr(dst, nsap);
	rt = rtalloc1(sisotosa(&dst), 0);
#ifdef ARGO_DEBUG
	if (argo_debug[D_SNPA]) {
		printf("snpac_add: rtalloc1 returns %p\n", rt);
	}
#endif
	if (rt == 0) {
		struct sockaddr *netmask;
		int             flags;
add:
		if (nsellength) {
			netmask = sisotosa(&msk);
			flags = RTF_UP;
			snpac_fixdstandmask(nsellength);
		} else {
			netmask = 0;
			flags = RTF_UP | RTF_HOST;
		}
		new_entry = 1;
		zap_linkaddr((&gte_dl), snpa, snpalen, index);
		gte_dl.sdl_type = iftype;
		if (rtrequest(RTM_ADD, sisotosa(&dst), S(gte_dl), netmask,
			      flags, &mrt) || mrt == 0)
			return (0);
		rt = mrt;
		rt->rt_refcnt--;
	} else {
		struct sockaddr_dl *sdl = (struct sockaddr_dl *) rt->rt_gateway;
		rt->rt_refcnt--;
		if ((rt->rt_flags & RTF_LLINFO) == 0)
			goto add;
		if (nsellength && (rt->rt_flags & RTF_HOST)) {
			if (rt->rt_refcnt == 0) {
				rtrequest(RTM_DELETE, sisotosa(&dst),
				(struct sockaddr *) 0, (struct sockaddr *) 0,
					  0, (struct rtentry **) 0);
				rt = 0;
				goto add;
			} else {
				static struct iso_addr nsap2;
				char  *cp;
				nsap2 = *nsap;
				cp = nsap2.isoa_genaddr + nsap->isoa_len - nsellength;
				while (cp < (char *) (1 + &nsap2))
					*cp++ = 0;
				(void) snpac_add(ifp, &nsap2, snpa, type, ht, nsellength);
			}
		}
		if (sdl->sdl_family != AF_LINK || sdl->sdl_alen == 0) {
			int             old_sdl_len = sdl->sdl_len;
			if (old_sdl_len < sizeof(*sdl)) {
				log(LOG_DEBUG, "snpac_add: cant make room for lladdr\n");
				return (0);
			}
			zap_linkaddr(sdl, snpa, snpalen, index);
			sdl->sdl_len = old_sdl_len;
			sdl->sdl_type = iftype;
			new_entry = 1;
		}
	}
	if ((lc = (struct llinfo_llc *) rt->rt_llinfo) == 0)
		panic("snpac_rtrequest");
	rt->rt_rmx.rmx_expire = ht + time.tv_sec;
	lc->lc_flags = SNPA_VALID | type;
	if ((type & SNPA_IS) && !(iso_systype & SNPA_IS))
		snpac_logdefis(rt);
	return (new_entry);
}

static void
snpac_fixdstandmask(int nsellength)
{
	char  *cp = msk.siso_data, *cplim;

	cplim = cp + (dst.siso_nlen -= nsellength);
	msk.siso_len = cplim - (char *) &msk;
	msk.siso_nlen = 0;
	while (cp < cplim)
		*cp++ = -1;
	while (cp < (char *) msk.siso_pad)
		*cp++ = 0;
	for (cp = dst.siso_data + dst.siso_nlen; cp < (char *) dst.siso_pad;)
		*cp++ = 0;
}

/*
 * FUNCTION:		snpac_ioctl
 *
 * PURPOSE:			Set/Get the system type and esis parameters
 *
 * RETURNS:			0 on success, or unix error code
 *
 * SIDE EFFECTS:
 *
 * NOTES:
 */
int
snpac_ioctl(
	struct socket *so,
	u_long cmd,		/* ioctl to process */
	caddr_t data,		/* data for the cmd */
	struct proc *p)
{
	struct systype_req *rq = (struct systype_req *) data;

#ifdef ARGO_DEBUG
	if (argo_debug[D_IOCTL]) {
		if (cmd == SIOCSSTYPE)
			printf("snpac_ioctl: cmd set, type x%x, ht %d, ct %d\n",
			    rq->sr_type, rq->sr_holdt, rq->sr_configt);
		else
			printf("snpac_ioctl: cmd get\n");
	}
#endif

	if (cmd == SIOCSSTYPE) {
		if (p == 0 || suser(p->p_ucred, &p->p_acflag))
			return (EPERM);
		if ((rq->sr_type & (SNPA_ES | SNPA_IS)) == (SNPA_ES | SNPA_IS))
			return (EINVAL);
		if (rq->sr_type & SNPA_ES) {
			iso_systype = SNPA_ES;
		} else if (rq->sr_type & SNPA_IS) {
			iso_systype = SNPA_IS;
		} else {
			return (EINVAL);
		}
		esis_holding_time = rq->sr_holdt;
		esis_config_time = rq->sr_configt;
		if (esis_esconfig_time != rq->sr_esconfigt) {
			callout_stop(&esis_config_ch);
			esis_esconfig_time = rq->sr_esconfigt;
			esis_config(NULL);
		}
	} else if (cmd == SIOCGSTYPE) {
		rq->sr_type = iso_systype;
		rq->sr_holdt = esis_holding_time;
		rq->sr_configt = esis_config_time;
		rq->sr_esconfigt = esis_esconfig_time;
	} else {
		return (EINVAL);
	}
	return (0);
}

/*
 * FUNCTION:		snpac_logdefis
 *
 * PURPOSE:			Mark the IS passed as the default IS
 *
 * RETURNS:			nothing
 *
 * SIDE EFFECTS:
 *
 * NOTES:
 */
void
snpac_logdefis(struct rtentry *sc)
{
	struct rtentry *rt;

	if (known_is == sc || !(sc->rt_flags & RTF_HOST))
		return;
	if (known_is) {
		RTFREE(known_is);
	}
	known_is = sc;
	sc->rt_refcnt++;
	rt = rtalloc1((struct sockaddr *) & zsi, 0);
	if (rt == 0)
		rtrequest(RTM_ADD, sisotosa(&zsi), rt_key(sc), sisotosa(&zmk),
			  RTF_DYNAMIC | RTF_GATEWAY, 0);
	else {
		if ((rt->rt_flags & RTF_DYNAMIC) &&
		    (rt->rt_flags & RTF_GATEWAY) && rt_mask(rt)->sa_len == 0)
			rt_setgate(rt, rt_key(rt), rt_key(sc));
	}
}

/*
 * FUNCTION:		snpac_age
 *
 * PURPOSE:		Time out snpac entries
 *
 * RETURNS:
 *
 * SIDE EFFECTS:
 *
 * NOTES:		When encountering an entry for the first time, snpac_age
 *			may delete up to SNPAC_AGE too many seconds. Ie.
 *			if the entry is added a moment before snpac_age is
 *			called, the entry will immediately have SNPAC_AGE
 *			seconds taken off the holding time, even though
 *			it has only been held a brief moment.
 *
 *			The proper way to do this is set an expiry timeval
 *			equal to current time + holding time. Then snpac_age
 *			would time out entries where expiry date is older
 *			than the current time.
 */
/*ARGSUSED*/
void
snpac_age(void *v)
{
	struct llinfo_llc *lc, *nlc;
	struct rtentry *rt;

	callout_reset(&snpac_age_ch, SNPAC_AGE * hz, snpac_age, NULL);

	for (lc = llinfo_llc.lh_first; lc != 0; lc = nlc) {
		nlc = lc->lc_list.le_next;
		if (lc->lc_flags & SNPA_VALID) {
			rt = lc->lc_rt;
			if (rt->rt_rmx.rmx_expire && rt->rt_rmx.rmx_expire < time.tv_sec)
				snpac_free(lc);
		}
	}
}

/*
 * FUNCTION:		snpac_ownmulti
 *
 * PURPOSE:		Determine if the snpa address is a multicast address
 *			of the same type as the system.
 *
 * RETURNS:		true or false
 *
 * SIDE EFFECTS:
 *
 * NOTES:		Used by interface drivers when not in eavesdrop mode
 *			as interm kludge until
 *			real multicast addresses can be configured
 */
int
snpac_ownmulti(caddr_t snpa, u_int len)
{
	return (((iso_systype & SNPA_ES) &&
		 (!memcmp(snpa, all_es_snpa, len))) ||
		((iso_systype & SNPA_IS) &&
		 (!memcmp(snpa, all_is_snpa, len))));
}

/*
 * FUNCTION:		snpac_flushifp
 *
 * PURPOSE:		Flush entries associated with specific ifp
 *
 * RETURNS:		nothing
 *
 * SIDE EFFECTS:
 *
 * NOTES:
 */
void
snpac_flushifp(struct ifnet *ifp)
{
	struct llinfo_llc *lc;

	for (lc = llinfo_llc.lh_first; lc != 0; lc = lc->lc_list.le_next) {
		if (lc->lc_rt->rt_ifp == ifp && (lc->lc_flags & SNPA_VALID))
			snpac_free(lc);
	}
}

/*
 * FUNCTION:		snpac_rtrequest
 *
 * PURPOSE:		Make a routing request
 *
 * RETURNS:		nothing
 *
 * SIDE EFFECTS:
 *
 * NOTES:		In the future, this should make a request of a user
 *			level routing daemon.
 */
void
snpac_rtrequest(int req, struct iso_addr *host, struct iso_addr *gateway,
	struct iso_addr *netmask, int flags, struct rtentry **ret_nrt)
{
	struct iso_addr *r;

#ifdef ARGO_DEBUG
	if (argo_debug[D_SNPA]) {
		printf("snpac_rtrequest: ");
		if (req == RTM_ADD)
			printf("add");
		else if (req == RTM_DELETE)
			printf("delete");
		else
			printf("unknown command");
		printf(" dst: %s\n", clnp_iso_addrp(host));
		printf("\tgateway: %s\n", clnp_iso_addrp(gateway));
	}
#endif


	zap_isoaddr(dst, host);
	zap_isoaddr(gte, gateway);
	if (netmask) {
		zap_isoaddr(msk, netmask);
		msk.siso_nlen = 0;
		msk.siso_len = msk.siso_pad - (u_char *) & msk;
	}
	rtrequest(req, sisotosa(&dst), sisotosa(&gte),
	(netmask ? sisotosa(&msk) : (struct sockaddr *) 0), flags, ret_nrt);
}

/*
 * FUNCTION:		snpac_addrt
 *
 * PURPOSE:		Associate a routing entry with an snpac entry
 *
 * RETURNS:		nothing
 *
 * SIDE EFFECTS:
 *
 * NOTES:		If a cache entry exists for gateway, then
 *			make a routing entry (host, gateway) and associate
 *			with gateway.
 *
 *			If a route already exists and is different, first delete
 *			it.
 *
 *			This could be made more efficient by checking
 *			the existing route before adding a new one.
 */
void
snpac_addrt(struct ifnet *ifp, struct iso_addr *host, struct iso_addr *gateway,
	struct iso_addr *netmask)
{
	struct iso_addr *r;

	zap_isoaddr(dst, host);
	zap_isoaddr(gte, gateway);
	if (netmask) {
		zap_isoaddr(msk, netmask);
		msk.siso_nlen = 0;
		msk.siso_len = msk.siso_pad - (u_char *) & msk;
		rtredirect(sisotosa(&dst), sisotosa(&gte), sisotosa(&msk),
			   RTF_DONE, sisotosa(&gte), 0);
	} else
		rtredirect(sisotosa(&dst), sisotosa(&gte), (struct sockaddr *) 0,
			   RTF_DONE | RTF_HOST, sisotosa(&gte), 0);
}
#endif				/* ISO */