[apple/xnu.git] / bsd / netinet / ip_encap.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*	$FreeBSD: src/sys/netinet/ip_encap.c,v 1.1.2.2 2001/07/03 11:01:46 ume Exp $	*/
/*	$KAME: ip_encap.c,v 1.41 2001/03/15 08:35:08 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.
 */
/*
 * My grandfather said that there's a devil inside tunnelling technology...
 *
 * We have surprisingly many protocols that want packets with IP protocol
 * #4 or #41.  Here's a list of protocols that want protocol #41:
 *	RFC1933 configured tunnel
 *	RFC1933 automatic tunnel
 *	RFC2401 IPsec tunnel
 *	RFC2473 IPv6 generic packet tunnelling
 *	RFC2529 6over4 tunnel
 *	mobile-ip6 (uses RFC2473)
 *	6to4 tunnel
 * Here's a list of protocol that want protocol #4:
 *	RFC1853 IPv4-in-IPv4 tunnelling
 *	RFC2003 IPv4 encapsulation within IPv4
 *	RFC2344 reverse tunnelling for mobile-ip4
 *	RFC2401 IPsec tunnel
 * Well, what can I say.  They impose different en/decapsulation mechanism
 * from each other, so they need separate protocol handler.  The only one
 * we can easily determine by protocol # is IPsec, which always has
 * AH/ESP/IPComp header right after outer IP header.
 *
 * So, clearly good old protosw does not work for protocol #4 and #41.
 * The code will let you match protocol via src/dst address pair.
 */
/* XXX is M_NETADDR correct? */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/protosw.h>
#include <sys/queue.h>

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

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_encap.h>
#if MROUTING
#include <netinet/ip_mroute.h>
#endif /* MROUTING */

#if INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/ip6protosw.h>
#endif


#include <net/net_osdep.h>

#ifndef __APPLE__
#include <sys/kernel.h>
#include <sys/malloc.h>
MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
#endif

static void encap_add __P((struct encaptab *));
static int mask_match __P((const struct encaptab *, const struct sockaddr *,
		const struct sockaddr *));
static void encap_fillarg __P((struct mbuf *, const struct encaptab *));

#ifndef LIST_HEAD_INITIALIZER
/* rely upon BSS initialization */
LIST_HEAD(, encaptab) encaptab;
#else
LIST_HEAD(, encaptab) encaptab = LIST_HEAD_INITIALIZER(&encaptab);
#endif

void
encap_init()
{
	static int initialized = 0;

	if (initialized)
		return;
	initialized++;
#if 0
	/*
	 * we cannot use LIST_INIT() here, since drivers may want to call
	 * encap_attach(), on driver attach.  encap_init() will be called
	 * on AF_INET{,6} initialization, which happens after driver
	 * initialization - using LIST_INIT() here can nuke encap_attach()
	 * from drivers.
	 */
	LIST_INIT(&encaptab);
#endif
}

#if INET
void
encap4_input(m, off)
	struct mbuf *m;
	int off;
{
	int proto;
	struct ip *ip;
	struct sockaddr_in s, d;
	const struct protosw *psw;
	struct encaptab *ep, *match;
	int prio, matchprio;

#ifndef __APPLE__
	va_start(ap, m);
	off = va_arg(ap, int);
	proto = va_arg(ap, int);
	va_end(ap);
#endif

	ip = mtod(m, struct ip *);
#ifdef __APPLE__
	proto = ip->ip_p;
#endif

	bzero(&s, sizeof(s));
	s.sin_family = AF_INET;
	s.sin_len = sizeof(struct sockaddr_in);
	s.sin_addr = ip->ip_src;
	bzero(&d, sizeof(d));
	d.sin_family = AF_INET;
	d.sin_len = sizeof(struct sockaddr_in);
	d.sin_addr = ip->ip_dst;

	match = NULL;
	matchprio = 0;
	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
		if (ep->af != AF_INET)
			continue;
		if (ep->proto >= 0 && ep->proto != proto)
			continue;
		if (ep->func)
			prio = (*ep->func)(m, off, proto, ep->arg);
		else {
			/*
			 * it's inbound traffic, we need to match in reverse
			 * order
			 */
			prio = mask_match(ep, (struct sockaddr *)&d,
			    (struct sockaddr *)&s);
		}

		/*
		 * We prioritize the matches by using bit length of the
		 * matches.  mask_match() and user-supplied matching function
		 * should return the bit length of the matches (for example,
		 * if both src/dst are matched for IPv4, 64 should be returned).
		 * 0 or negative return value means "it did not match".
		 *
		 * The question is, since we have two "mask" portion, we
		 * cannot really define total order between entries.
		 * For example, which of these should be preferred?
		 * mask_match() returns 48 (32 + 16) for both of them.
		 *	src=3ffe::/16, dst=3ffe:501::/32
		 *	src=3ffe:501::/32, dst=3ffe::/16
		 *
		 * We need to loop through all the possible candidates
		 * to get the best match - the search takes O(n) for
		 * n attachments (i.e. interfaces).
		 */
		if (prio <= 0)
			continue;
		if (prio > matchprio) {
			matchprio = prio;
			match = ep;
		}
	}

	if (match) {
		/* found a match, "match" has the best one */
		psw = (const struct protosw *)match->psw;
		if (psw && psw->pr_input) {
			encap_fillarg(m, match);
			(*psw->pr_input)(m, off);
		} else
			m_freem(m);
		return;
	}

	/* for backward compatibility */
# if MROUTING
#  define COMPATFUNC	ipip_input
# endif /*MROUTING*/

#if COMPATFUNC
	if (proto == IPPROTO_IPV4) {
		COMPATFUNC(m, off);
		return;
	}
#endif

	/* last resort: inject to raw socket */
	rip_input(m, off);
}
#endif

#if INET6
int
encap6_input(mp, offp)
	struct mbuf **mp;
	int *offp;
{
	struct mbuf *m = *mp;
	struct ip6_hdr *ip6;
	struct sockaddr_in6 s, d;
	const struct ip6protosw *psw;
	struct encaptab *ep, *match;
	int prio, matchprio;
	int proto;

	ip6 = mtod(m, struct ip6_hdr *);
	proto = ip6->ip6_nxt;

	bzero(&s, sizeof(s));
	s.sin6_family = AF_INET6;
	s.sin6_len = sizeof(struct sockaddr_in6);
	s.sin6_addr = ip6->ip6_src;
	bzero(&d, sizeof(d));
	d.sin6_family = AF_INET6;
	d.sin6_len = sizeof(struct sockaddr_in6);
	d.sin6_addr = ip6->ip6_dst;

	match = NULL;
	matchprio = 0;
	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
		if (ep->af != AF_INET6)
			continue;
		if (ep->proto >= 0 && ep->proto != proto)
			continue;
		if (ep->func)
			prio = (*ep->func)(m, *offp, proto, ep->arg);
		else {
			/*
			 * it's inbound traffic, we need to match in reverse
			 * order
			 */
			prio = mask_match(ep, (struct sockaddr *)&d,
			    (struct sockaddr *)&s);
		}

		/* see encap4_input() for issues here */
		if (prio <= 0)
			continue;
		if (prio > matchprio) {
			matchprio = prio;
			match = ep;
		}
	}

	if (match) {
		/* found a match */
		psw = (const struct ip6protosw *)match->psw;
		if (psw && psw->pr_input) {
			encap_fillarg(m, match);
			return (*psw->pr_input)(mp, offp);
		} else {
			m_freem(m);
			return IPPROTO_DONE;
		}
	}

	/* last resort: inject to raw socket */
	return rip6_input(mp, offp);
}
#endif

static void
encap_add(ep)
	struct encaptab *ep;
{

	LIST_INSERT_HEAD(&encaptab, ep, chain);
}

/*
 * sp (src ptr) is always my side, and dp (dst ptr) is always remote side.
 * length of mask (sm and dm) is assumed to be same as sp/dp.
 * Return value will be necessary as input (cookie) for encap_detach().
 */
const struct encaptab *
encap_attach(af, proto, sp, sm, dp, dm, psw, arg)
	int af;
	int proto;
	const struct sockaddr *sp, *sm;
	const struct sockaddr *dp, *dm;
	const struct protosw *psw;
	void *arg;
{
	struct encaptab *ep;
	int error;
	int s;

	s = splnet();
	/* sanity check on args */
	if (sp->sa_len > sizeof(ep->src) || dp->sa_len > sizeof(ep->dst)) {
		error = EINVAL;
		goto fail;
	}
	if (sp->sa_len != dp->sa_len) {
		error = EINVAL;
		goto fail;
	}
	if (af != sp->sa_family || af != dp->sa_family) {
		error = EINVAL;
		goto fail;
	}

	/* check if anyone have already attached with exactly same config */
	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
		if (ep->af != af)
			continue;
		if (ep->proto != proto)
			continue;
		if (ep->src.ss_len != sp->sa_len ||
		    bcmp(&ep->src, sp, sp->sa_len) != 0 ||
		    bcmp(&ep->srcmask, sm, sp->sa_len) != 0)
			continue;
		if (ep->dst.ss_len != dp->sa_len ||
		    bcmp(&ep->dst, dp, dp->sa_len) != 0 ||
		    bcmp(&ep->dstmask, dm, dp->sa_len) != 0)
			continue;

		error = EEXIST;
		goto fail;
	}

	ep = _MALLOC(sizeof(*ep), M_NETADDR, M_WAITOK);	/*XXX*/
	if (ep == NULL) {
		error = ENOBUFS;
		goto fail;
	}
	bzero(ep, sizeof(*ep));

	ep->af = af;
	ep->proto = proto;
	bcopy(sp, &ep->src, sp->sa_len);
	bcopy(sm, &ep->srcmask, sp->sa_len);
	bcopy(dp, &ep->dst, dp->sa_len);
	bcopy(dm, &ep->dstmask, dp->sa_len);
	ep->psw = psw;
	ep->arg = arg;

	encap_add(ep);

	error = 0;
	splx(s);
	return ep;

fail:
	splx(s);
	return NULL;
}

const struct encaptab *
encap_attach_func(af, proto, func, psw, arg)
	int af;
	int proto;
	int (*func) __P((const struct mbuf *, int, int, void *));
	const struct protosw *psw;
	void *arg;
{
	struct encaptab *ep;
	int error;
	int s;

	s = splnet();
	/* sanity check on args */
	if (!func) {
		error = EINVAL;
		goto fail;
	}

	ep = _MALLOC(sizeof(*ep), M_NETADDR, M_WAITOK);	/*XXX*/
	if (ep == NULL) {
		error = ENOBUFS;
		goto fail;
	}
	bzero(ep, sizeof(*ep));

	ep->af = af;
	ep->proto = proto;
	ep->func = func;
	ep->psw = psw;
	ep->arg = arg;

	encap_add(ep);

	error = 0;
	splx(s);
	return ep;

fail:
	splx(s);
	return NULL;
}

int
encap_detach(cookie)
	const struct encaptab *cookie;
{
	const struct encaptab *ep = cookie;
	struct encaptab *p;

	for (p = LIST_FIRST(&encaptab); p; p = LIST_NEXT(p, chain)) {
		if (p == ep) {
			LIST_REMOVE(p, chain);
			_FREE(p, M_NETADDR);	/*XXX*/
			return 0;
		}
	}

	return EINVAL;
}

static int
mask_match(ep, sp, dp)
	const struct encaptab *ep;
	const struct sockaddr *sp;
	const struct sockaddr *dp;
{
	struct sockaddr_storage s;
	struct sockaddr_storage d;
	int i;
	const u_int8_t *p, *q;
	u_int8_t *r;
	int matchlen;

	if (sp->sa_len > sizeof(s) || dp->sa_len > sizeof(d))
		return 0;
	if (sp->sa_family != ep->af || dp->sa_family != ep->af)
		return 0;
	if (sp->sa_len != ep->src.ss_len || dp->sa_len != ep->dst.ss_len)
		return 0;

	matchlen = 0;

	p = (const u_int8_t *)sp;
	q = (const u_int8_t *)&ep->srcmask;
	r = (u_int8_t *)&s;
	for (i = 0 ; i < sp->sa_len; i++) {
		r[i] = p[i] & q[i];
		/* XXX estimate */
		matchlen += (q[i] ? 8 : 0);
	}

	p = (const u_int8_t *)dp;
	q = (const u_int8_t *)&ep->dstmask;
	r = (u_int8_t *)&d;
	for (i = 0 ; i < dp->sa_len; i++) {
		r[i] = p[i] & q[i];
		/* XXX rough estimate */
		matchlen += (q[i] ? 8 : 0);
	}

	/* need to overwrite len/family portion as we don't compare them */
	s.ss_len = sp->sa_len;
	s.ss_family = sp->sa_family;
	d.ss_len = dp->sa_len;
	d.ss_family = dp->sa_family;

	if (bcmp(&s, &ep->src, ep->src.ss_len) == 0 &&
	    bcmp(&d, &ep->dst, ep->dst.ss_len) == 0) {
		return matchlen;
	} else
		return 0;
}

static void
encap_fillarg(m, ep)
	struct mbuf *m;
	const struct encaptab *ep;
{
#if 0
	m->m_pkthdr.aux = ep->arg;
#else
	struct mbuf *n;

	n = m_aux_add(m, AF_INET, IPPROTO_IPV4);
	if (n) {
		*mtod(n, void **) = ep->arg;
		n->m_len = sizeof(void *);
	}
#endif
}

void *
encap_getarg(m)
	struct mbuf *m;
{
	void *p;
#if 0
	p = m->m_pkthdr.aux;
	m->m_pkthdr.aux = NULL;
	return p;
#else
	struct mbuf *n;

	p = NULL;
	n = m_aux_find(m, AF_INET, IPPROTO_IPV4);
	if (n) {
		if (n->m_len == sizeof(void *))
			p = *mtod(n, void **);
		m_aux_delete(m, n);
	}
	return p;
#endif
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
9bccf70c A	22	/* $FreeBSD: src/sys/netinet/ip_encap.c,v 1.1.2.2 2001/07/03 11:01:46 ume Exp $ */
9bccf70c A	23	/* $KAME: ip_encap.c,v 1.41 2001/03/15 08:35:08 itojun Exp $ */
1c79356b A	24
	25	/*
	26	* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
	27	* All rights reserved.
	28	*
	29	* Redistribution and use in source and binary forms, with or without
	30	* modification, are permitted provided that the following conditions
	31	* are met:
	32	* 1. Redistributions of source code must retain the above copyright
	33	* notice, this list of conditions and the following disclaimer.
	34	* 2. Redistributions in binary form must reproduce the above copyright
	35	* notice, this list of conditions and the following disclaimer in the
	36	* documentation and/or other materials provided with the distribution.
	37	* 3. Neither the name of the project nor the names of its contributors
	38	* may be used to endorse or promote products derived from this software
	39	* without specific prior written permission.
	40	*
	41	* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	42	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	43	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	44	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	45	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	46	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	47	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	48	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	49	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	50	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	51	* SUCH DAMAGE.
	52	*/
	53	/*
	54	* My grandfather said that there's a devil inside tunnelling technology...
	55	*
	56	* We have surprisingly many protocols that want packets with IP protocol
	57	* #4 or #41. Here's a list of protocols that want protocol #41:
	58	* RFC1933 configured tunnel
	59	* RFC1933 automatic tunnel
	60	* RFC2401 IPsec tunnel
	61	* RFC2473 IPv6 generic packet tunnelling
	62	* RFC2529 6over4 tunnel
	63	* mobile-ip6 (uses RFC2473)
	64	* 6to4 tunnel
	65	* Here's a list of protocol that want protocol #4:
9bccf70c A	66	* RFC1853 IPv4-in-IPv4 tunnelling
9bccf70c A	67	* RFC2003 IPv4 encapsulation within IPv4
1c79356b A	68	* RFC2344 reverse tunnelling for mobile-ip4
	69	* RFC2401 IPsec tunnel
	70	* Well, what can I say. They impose different en/decapsulation mechanism
	71	* from each other, so they need separate protocol handler. The only one
	72	* we can easily determine by protocol # is IPsec, which always has
	73	* AH/ESP/IPComp header right after outer IP header.
	74	*
	75	* So, clearly good old protosw does not work for protocol #4 and #41.
	76	* The code will let you match protocol via src/dst address pair.
	77	*/
9bccf70c	78	/* XXX is M_NETADDR correct? */
1c79356b A	79
	80	#include <sys/param.h>
	81	#include <sys/systm.h>
	82	#include <sys/socket.h>
	83	#include <sys/sockio.h>
	84	#include <sys/mbuf.h>
	85	#include <sys/errno.h>
	86	#include <sys/protosw.h>
9bccf70c	87	#include <sys/queue.h>
1c79356b A	88
	89	#include <net/if.h>
	90	#include <net/route.h>
	91
	92	#include <netinet/in.h>
	93	#include <netinet/in_systm.h>
	94	#include <netinet/ip.h>
	95	#include <netinet/ip_var.h>
	96	#include <netinet/ip_encap.h>
	97	#if MROUTING
	98	#include <netinet/ip_mroute.h>
	99	#endif /* MROUTING */
1c79356b A	100
	101	#if INET6
	102	#include <netinet/ip6.h>
	103	#include <netinet6/ip6_var.h>
	104	#include <netinet6/ip6protosw.h>
	105	#endif
	106
	107
	108	#include <net/net_osdep.h>
	109
9bccf70c	110	#ifndef __APPLE__
1c79356b A	111	#include <sys/kernel.h>
	112	#include <sys/malloc.h>
	113	MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
	114	#endif
	115
9bccf70c	116	static void encap_add __P((struct encaptab *));
1c79356b A	117	static int mask_match __P((const struct encaptab , const struct sockaddr ,
	118	const struct sockaddr *));
	119	static void encap_fillarg __P((struct mbuf , const struct encaptab ));
	120
9bccf70c	121	#ifndef LIST_HEAD_INITIALIZER
1c79356b A	122	/* rely upon BSS initialization */
1c79356b A	123	LIST_HEAD(, encaptab) encaptab;
9bccf70c A	124	#else
	125	LIST_HEAD(, encaptab) encaptab = LIST_HEAD_INITIALIZER(&encaptab);
	126	#endif
1c79356b A	127
	128	void
	129	encap_init()
	130	{
9bccf70c A	131	static int initialized = 0;
	132
	133	if (initialized)
	134	return;
	135	initialized++;
1c79356b A	136	#if 0
	137	/*
	138	* we cannot use LIST_INIT() here, since drivers may want to call
9bccf70c	139	* encap_attach(), on driver attach. encap_init() will be called
1c79356b A	140	* on AF_INET{,6} initialization, which happens after driver
	141	* initialization - using LIST_INIT() here can nuke encap_attach()
	142	* from drivers.
	143	*/
	144	LIST_INIT(&encaptab);
	145	#endif
	146	}
	147
9bccf70c	148	#if INET
1c79356b	149	void
9bccf70c	150	encap4_input(m, off)
1c79356b A	151	struct mbuf *m;
1c79356b A	152	int off;
1c79356b	153	{
9bccf70c	154	int proto;
1c79356b A	155	struct ip *ip;
1c79356b A	156	struct sockaddr_in s, d;
9bccf70c A	157	const struct protosw *psw;
	158	struct encaptab ep, match;
	159	int prio, matchprio;
	160
	161	#ifndef __APPLE__
	162	va_start(ap, m);
	163	off = va_arg(ap, int);
	164	proto = va_arg(ap, int);
	165	va_end(ap);
	166	#endif
1c79356b A	167
1c79356b A	168	ip = mtod(m, struct ip *);
9bccf70c	169	#ifdef __APPLE__
1c79356b A	170	proto = ip->ip_p;
	171	#endif
	172
	173	bzero(&s, sizeof(s));
	174	s.sin_family = AF_INET;
	175	s.sin_len = sizeof(struct sockaddr_in);
	176	s.sin_addr = ip->ip_src;
	177	bzero(&d, sizeof(d));
	178	d.sin_family = AF_INET;
	179	d.sin_len = sizeof(struct sockaddr_in);
	180	d.sin_addr = ip->ip_dst;
	181
9bccf70c A	182	match = NULL;
9bccf70c A	183	matchprio = 0;
1c79356b	184	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
9bccf70c A	185	if (ep->af != AF_INET)
9bccf70c A	186	continue;
1c79356b A	187	if (ep->proto >= 0 && ep->proto != proto)
1c79356b A	188	continue;
9bccf70c A	189	if (ep->func)
	190	prio = (*ep->func)(m, off, proto, ep->arg);
	191	else {
1c79356b A	192	/*
	193	* it's inbound traffic, we need to match in reverse
	194	* order
	195	*/
9bccf70c A	196	prio = mask_match(ep, (struct sockaddr *)&d,
9bccf70c A	197	(struct sockaddr *)&s);
1c79356b A	198	}
1c79356b A	199
9bccf70c A	200	/*
	201	* We prioritize the matches by using bit length of the
	202	* matches. mask_match() and user-supplied matching function
	203	* should return the bit length of the matches (for example,
	204	* if both src/dst are matched for IPv4, 64 should be returned).
	205	* 0 or negative return value means "it did not match".
	206	*
	207	* The question is, since we have two "mask" portion, we
	208	* cannot really define total order between entries.
	209	* For example, which of these should be preferred?
	210	* mask_match() returns 48 (32 + 16) for both of them.
	211	* src=3ffe::/16, dst=3ffe:501::/32
	212	* src=3ffe:501::/32, dst=3ffe::/16
	213	*
	214	* We need to loop through all the possible candidates
	215	* to get the best match - the search takes O(n) for
	216	* n attachments (i.e. interfaces).
	217	*/
	218	if (prio <= 0)
	219	continue;
	220	if (prio > matchprio) {
	221	matchprio = prio;
	222	match = ep;
	223	}
	224	}
	225
	226	if (match) {
	227	/* found a match, "match" has the best one */
	228	psw = (const struct protosw *)match->psw;
	229	if (psw && psw->pr_input) {
	230	encap_fillarg(m, match);
	231	(*psw->pr_input)(m, off);
1c79356b A	232	} else
	233	m_freem(m);
	234	return;
	235	}
	236
	237	/* for backward compatibility */
9bccf70c A	238	# if MROUTING
	239	# define COMPATFUNC ipip_input
	240	# endif /MROUTING/
	241
	242	#if COMPATFUNC
1c79356b	243	if (proto == IPPROTO_IPV4) {
9bccf70c	244	COMPATFUNC(m, off);
1c79356b	245	return;
1c79356b	246	}
9bccf70c	247	#endif
1c79356b A	248
	249	/* last resort: inject to raw socket */
	250	rip_input(m, off);
	251	}
9bccf70c	252	#endif
1c79356b A	253
	254	#if INET6
	255	int
9bccf70c	256	encap6_input(mp, offp)
1c79356b A	257	struct mbuf **mp;
1c79356b A	258	int *offp;
1c79356b A	259	{
	260	struct mbuf m = mp;
	261	struct ip6_hdr *ip6;
	262	struct sockaddr_in6 s, d;
9bccf70c A	263	const struct ip6protosw *psw;
	264	struct encaptab ep, match;
	265	int prio, matchprio;
	266	int proto;
1c79356b A	267
1c79356b A	268	ip6 = mtod(m, struct ip6_hdr *);
9bccf70c	269	proto = ip6->ip6_nxt;
1c79356b A	270
	271	bzero(&s, sizeof(s));
	272	s.sin6_family = AF_INET6;
	273	s.sin6_len = sizeof(struct sockaddr_in6);
	274	s.sin6_addr = ip6->ip6_src;
	275	bzero(&d, sizeof(d));
	276	d.sin6_family = AF_INET6;
	277	d.sin6_len = sizeof(struct sockaddr_in6);
	278	d.sin6_addr = ip6->ip6_dst;
	279
9bccf70c A	280	match = NULL;
9bccf70c A	281	matchprio = 0;
1c79356b	282	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
9bccf70c A	283	if (ep->af != AF_INET6)
9bccf70c A	284	continue;
1c79356b A	285	if (ep->proto >= 0 && ep->proto != proto)
1c79356b A	286	continue;
9bccf70c A	287	if (ep->func)
	288	prio = (ep->func)(m, offp, proto, ep->arg);
	289	else {
1c79356b A	290	/*
	291	* it's inbound traffic, we need to match in reverse
	292	* order
	293	*/
9bccf70c A	294	prio = mask_match(ep, (struct sockaddr *)&d,
	295	(struct sockaddr *)&s);
	296	}
	297
	298	/* see encap4_input() for issues here */
	299	if (prio <= 0)
	300	continue;
	301	if (prio > matchprio) {
	302	matchprio = prio;
	303	match = ep;
1c79356b	304	}
9bccf70c	305	}
1c79356b	306
9bccf70c	307	if (match) {
1c79356b	308	/* found a match */
9bccf70c	309	psw = (const struct ip6protosw *)match->psw;
1c79356b	310	if (psw && psw->pr_input) {
9bccf70c A	311	encap_fillarg(m, match);
9bccf70c A	312	return (*psw->pr_input)(mp, offp);
1c79356b A	313	} else {
	314	m_freem(m);
	315	return IPPROTO_DONE;
	316	}
	317	}
	318
	319	/* last resort: inject to raw socket */
9bccf70c	320	return rip6_input(mp, offp);
1c79356b A	321	}
	322	#endif
	323
9bccf70c A	324	static void
	325	encap_add(ep)
	326	struct encaptab *ep;
	327	{
	328
	329	LIST_INSERT_HEAD(&encaptab, ep, chain);
	330	}
	331
1c79356b A	332	/*
	333	* sp (src ptr) is always my side, and dp (dst ptr) is always remote side.
	334	* length of mask (sm and dm) is assumed to be same as sp/dp.
	335	* Return value will be necessary as input (cookie) for encap_detach().
	336	*/
	337	const struct encaptab *
	338	encap_attach(af, proto, sp, sm, dp, dm, psw, arg)
	339	int af;
	340	int proto;
	341	const struct sockaddr sp, sm;
	342	const struct sockaddr dp, dm;
	343	const struct protosw *psw;
	344	void *arg;
	345	{
	346	struct encaptab *ep;
	347	int error;
	348	int s;
	349
1c79356b	350	s = splnet();
1c79356b A	351	/* sanity check on args */
	352	if (sp->sa_len > sizeof(ep->src) \|\| dp->sa_len > sizeof(ep->dst)) {
	353	error = EINVAL;
	354	goto fail;
	355	}
	356	if (sp->sa_len != dp->sa_len) {
	357	error = EINVAL;
	358	goto fail;
	359	}
	360	if (af != sp->sa_family \|\| af != dp->sa_family) {
	361	error = EINVAL;
	362	goto fail;
	363	}
	364
	365	/* check if anyone have already attached with exactly same config */
	366	for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
	367	if (ep->af != af)
	368	continue;
	369	if (ep->proto != proto)
	370	continue;
	371	if (ep->src.ss_len != sp->sa_len \|\|
	372	bcmp(&ep->src, sp, sp->sa_len) != 0 \|\|
	373	bcmp(&ep->srcmask, sm, sp->sa_len) != 0)
	374	continue;
	375	if (ep->dst.ss_len != dp->sa_len \|\|
	376	bcmp(&ep->dst, dp, dp->sa_len) != 0 \|\|
	377	bcmp(&ep->dstmask, dm, dp->sa_len) != 0)
	378	continue;
	379
	380	error = EEXIST;
	381	goto fail;
	382	}
	383
9bccf70c	384	ep = _MALLOC(sizeof(ep), M_NETADDR, M_WAITOK); /XXX*/
1c79356b A	385	if (ep == NULL) {
	386	error = ENOBUFS;
	387	goto fail;
	388	}
	389	bzero(ep, sizeof(*ep));
	390
	391	ep->af = af;
	392	ep->proto = proto;
	393	bcopy(sp, &ep->src, sp->sa_len);
	394	bcopy(sm, &ep->srcmask, sp->sa_len);
	395	bcopy(dp, &ep->dst, dp->sa_len);
	396	bcopy(dm, &ep->dstmask, dp->sa_len);
	397	ep->psw = psw;
	398	ep->arg = arg;
	399
9bccf70c A	400	encap_add(ep);
9bccf70c A	401
1c79356b A	402	error = 0;
	403	splx(s);
	404	return ep;
	405
	406	fail:
	407	splx(s);
	408	return NULL;
	409	}
	410
	411	const struct encaptab *
	412	encap_attach_func(af, proto, func, psw, arg)
	413	int af;
	414	int proto;
	415	int (func) __P((const struct mbuf , int, int, void *));
	416	const struct protosw *psw;
	417	void *arg;
	418	{
	419	struct encaptab *ep;
	420	int error;
	421	int s;
	422
1c79356b	423	s = splnet();
1c79356b A	424	/* sanity check on args */
	425	if (!func) {
	426	error = EINVAL;
	427	goto fail;
	428	}
	429
9bccf70c	430	ep = _MALLOC(sizeof(ep), M_NETADDR, M_WAITOK); /XXX*/
1c79356b A	431	if (ep == NULL) {
	432	error = ENOBUFS;
	433	goto fail;
	434	}
	435	bzero(ep, sizeof(*ep));
	436
	437	ep->af = af;
	438	ep->proto = proto;
	439	ep->func = func;
	440	ep->psw = psw;
	441	ep->arg = arg;
	442
9bccf70c A	443	encap_add(ep);
9bccf70c A	444
1c79356b A	445	error = 0;
	446	splx(s);
	447	return ep;
	448
	449	fail:
	450	splx(s);
	451	return NULL;
	452	}
	453
	454	int
	455	encap_detach(cookie)
	456	const struct encaptab *cookie;
	457	{
	458	const struct encaptab *ep = cookie;
	459	struct encaptab *p;
	460
	461	for (p = LIST_FIRST(&encaptab); p; p = LIST_NEXT(p, chain)) {
	462	if (p == ep) {
	463	LIST_REMOVE(p, chain);
	464	_FREE(p, M_NETADDR); /XXX/
	465	return 0;
	466	}
	467	}
	468
	469	return EINVAL;
	470	}
	471
	472	static int
	473	mask_match(ep, sp, dp)
	474	const struct encaptab *ep;
	475	const struct sockaddr *sp;
	476	const struct sockaddr *dp;
	477	{
	478	struct sockaddr_storage s;
	479	struct sockaddr_storage d;
	480	int i;
9bccf70c A	481	const u_int8_t p, q;
	482	u_int8_t *r;
	483	int matchlen;
1c79356b A	484
	485	if (sp->sa_len > sizeof(s) \|\| dp->sa_len > sizeof(d))
	486	return 0;
	487	if (sp->sa_family != ep->af \|\| dp->sa_family != ep->af)
	488	return 0;
	489	if (sp->sa_len != ep->src.ss_len \|\| dp->sa_len != ep->dst.ss_len)
	490	return 0;
	491
9bccf70c A	492	matchlen = 0;
	493
	494	p = (const u_int8_t *)sp;
	495	q = (const u_int8_t *)&ep->srcmask;
1c79356b	496	r = (u_int8_t *)&s;
9bccf70c	497	for (i = 0 ; i < sp->sa_len; i++) {
1c79356b	498	r[i] = p[i] & q[i];
9bccf70c A	499	/* XXX estimate */
	500	matchlen += (q[i] ? 8 : 0);
	501	}
1c79356b	502
9bccf70c A	503	p = (const u_int8_t *)dp;
9bccf70c A	504	q = (const u_int8_t *)&ep->dstmask;
1c79356b	505	r = (u_int8_t *)&d;
9bccf70c	506	for (i = 0 ; i < dp->sa_len; i++) {
1c79356b	507	r[i] = p[i] & q[i];
9bccf70c A	508	/* XXX rough estimate */
	509	matchlen += (q[i] ? 8 : 0);
	510	}
1c79356b A	511
	512	/* need to overwrite len/family portion as we don't compare them */
	513	s.ss_len = sp->sa_len;
	514	s.ss_family = sp->sa_family;
	515	d.ss_len = dp->sa_len;
	516	d.ss_family = dp->sa_family;
	517
	518	if (bcmp(&s, &ep->src, ep->src.ss_len) == 0 &&
	519	bcmp(&d, &ep->dst, ep->dst.ss_len) == 0) {
9bccf70c	520	return matchlen;
1c79356b A	521	} else
	522	return 0;
	523	}
	524
	525	static void
	526	encap_fillarg(m, ep)
	527	struct mbuf *m;
	528	const struct encaptab *ep;
	529	{
	530	#if 0
	531	m->m_pkthdr.aux = ep->arg;
	532	#else
	533	struct mbuf *n;
	534
	535	n = m_aux_add(m, AF_INET, IPPROTO_IPV4);
	536	if (n) {
	537	mtod(n, void *) = ep->arg;
	538	n->m_len = sizeof(void *);
	539	}
	540	#endif
	541	}
	542
	543	void *
	544	encap_getarg(m)
	545	struct mbuf *m;
	546	{
	547	void *p;
	548	#if 0
	549	p = m->m_pkthdr.aux;
	550	m->m_pkthdr.aux = NULL;
	551	return p;
	552	#else
	553	struct mbuf *n;
	554
	555	p = NULL;
	556	n = m_aux_find(m, AF_INET, IPPROTO_IPV4);
	557	if (n) {
	558	if (n->m_len == sizeof(void *))
	559	p = mtod(n, void *);
	560	m_aux_delete(m, n);
	561	}
	562	return p;
	563	#endif
	564	}