in6_gif.c revision 1.27 
1/*	$NetBSD: in6_gif.c,v 1.27 2001/12/21 06:30:44 itojun Exp $	*/
2/*	$KAME: in6_gif.c,v 1.62 2001/07/29 04:27:25 itojun Exp $	*/
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34__KERNEL_RCSID(0, "$NetBSD: in6_gif.c,v 1.27 2001/12/21 06:30:44 itojun Exp $");
35
36#include "opt_inet.h"
37#include "opt_iso.h"
38
39/* define it if you want to use encap_attach_func (it helps *BSD merge) */
40#define USE_ENCAPCHECK
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/socket.h>
45#include <sys/sockio.h>
46#include <sys/mbuf.h>
47#include <sys/errno.h>
48#include <sys/ioctl.h>
49#include <sys/queue.h>
50#include <sys/syslog.h>
51#include <sys/protosw.h>
52
53#include <net/if.h>
54#include <net/route.h>
55
56#include <netinet/in.h>
57#include <netinet/in_systm.h>
58#ifdef INET
59#include <netinet/ip.h>
60#endif
61#include <netinet/ip_encap.h>
62#ifdef INET6
63#include <netinet/ip6.h>
64#include <netinet6/ip6_var.h>
65#include <netinet6/in6_gif.h>
66#include <netinet6/in6_var.h>
67#endif
68#include <netinet6/ip6protosw.h>
69#include <netinet/ip_ecn.h>
70
71#include <net/if_gif.h>
72
73#include <net/net_osdep.h>
74
75static int gif_validate6 __P((const struct ip6_hdr *, struct gif_softc *,
76	struct ifnet *));
77
78int	ip6_gif_hlim = GIF_HLIM;
79
80extern struct domain inet6domain;
81struct ip6protosw in6_gif_protosw =
82{ SOCK_RAW,	&inet6domain,	0/* IPPROTO_IPV[46] */,	PR_ATOMIC|PR_ADDR,
83  in6_gif_input, rip6_output,	in6_gif_ctlinput, rip6_ctloutput,
84  rip6_usrreq,
85  0,            0,              0,              0,
86};
87
88extern LIST_HEAD(, gif_softc) gif_softc_list;
89
90int
91in6_gif_output(ifp, family, m)
92	struct ifnet *ifp;
93	int family; /* family of the packet to be encapsulate. */
94	struct mbuf *m;
95{
96	struct gif_softc *sc = (struct gif_softc*)ifp;
97	struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
98	struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
99	struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
100	struct ip6_hdr *ip6;
101	int proto, error;
102	u_int8_t itos, otos;
103
104	if (sin6_src == NULL || sin6_dst == NULL ||
105	    sin6_src->sin6_family != AF_INET6 ||
106	    sin6_dst->sin6_family != AF_INET6) {
107		m_freem(m);
108		return EAFNOSUPPORT;
109	}
110
111	switch (family) {
112#ifdef INET
113	case AF_INET:
114	    {
115		struct ip *ip;
116
117		proto = IPPROTO_IPV4;
118		if (m->m_len < sizeof(*ip)) {
119			m = m_pullup(m, sizeof(*ip));
120			if (!m)
121				return ENOBUFS;
122		}
123		ip = mtod(m, struct ip *);
124		itos = ip->ip_tos;
125		break;
126	    }
127#endif
128#ifdef INET6
129	case AF_INET6:
130	    {
131		struct ip6_hdr *ip6;
132		proto = IPPROTO_IPV6;
133		if (m->m_len < sizeof(*ip6)) {
134			m = m_pullup(m, sizeof(*ip6));
135			if (!m)
136				return ENOBUFS;
137		}
138		ip6 = mtod(m, struct ip6_hdr *);
139		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
140		break;
141	    }
142#endif
143#ifdef ISO
144	case AF_ISO:
145		proto = IPPROTO_EON;
146		itos = 0;
147		break;
148#endif
149	default:
150#ifdef DEBUG
151		printf("in6_gif_output: warning: unknown family %d passed\n",
152			family);
153#endif
154		m_freem(m);
155		return EAFNOSUPPORT;
156	}
157
158	/* prepend new IP header */
159	M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
160	if (m && m->m_len < sizeof(struct ip6_hdr))
161		m = m_pullup(m, sizeof(struct ip6_hdr));
162	if (m == NULL)
163		return ENOBUFS;
164
165	ip6 = mtod(m, struct ip6_hdr *);
166	ip6->ip6_flow	= 0;
167	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
168	ip6->ip6_vfc	|= IPV6_VERSION;
169	ip6->ip6_plen	= htons((u_short)m->m_pkthdr.len);
170	ip6->ip6_nxt	= proto;
171	ip6->ip6_hlim	= ip6_gif_hlim;
172	ip6->ip6_src	= sin6_src->sin6_addr;
173	/* bidirectional configured tunnel mode */
174	if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
175		ip6->ip6_dst = sin6_dst->sin6_addr;
176	else  {
177		m_freem(m);
178		return ENETUNREACH;
179	}
180	if (ifp->if_flags & IFF_LINK1)
181		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
182	else
183		ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
184	ip6->ip6_flow &= ~ntohl(0xff00000);
185	ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
186
187	if (dst->sin6_family != sin6_dst->sin6_family ||
188	     !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
189		/* cache route doesn't match */
190		bzero(dst, sizeof(*dst));
191		dst->sin6_family = sin6_dst->sin6_family;
192		dst->sin6_len = sizeof(struct sockaddr_in6);
193		dst->sin6_addr = sin6_dst->sin6_addr;
194		if (sc->gif_ro6.ro_rt) {
195			RTFREE(sc->gif_ro6.ro_rt);
196			sc->gif_ro6.ro_rt = NULL;
197		}
198	}
199
200	if (sc->gif_ro6.ro_rt == NULL) {
201		rtalloc((struct route *)&sc->gif_ro6);
202		if (sc->gif_ro6.ro_rt == NULL) {
203			m_freem(m);
204			return ENETUNREACH;
205		}
206
207		/* if it constitutes infinite encapsulation, punt. */
208		if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
209			m_freem(m);
210			return ENETUNREACH;	/* XXX */
211		}
212	}
213
214#ifdef IPV6_MINMTU
215	/*
216	 * force fragmentation to minimum MTU, to avoid path MTU discovery.
217	 * it is too painful to ask for resend of inner packet, to achieve
218	 * path MTU discovery for encapsulated packets.
219	 */
220	error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL);
221#else
222	error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL);
223#endif
224
225	return(error);
226}
227
228int in6_gif_input(mp, offp, proto)
229	struct mbuf **mp;
230	int *offp, proto;
231{
232	struct mbuf *m = *mp;
233	struct ifnet *gifp = NULL;
234	struct ip6_hdr *ip6;
235	int af = 0;
236	u_int32_t otos;
237
238	ip6 = mtod(m, struct ip6_hdr *);
239
240	gifp = (struct ifnet *)encap_getarg(m);
241
242	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
243		m_freem(m);
244		ip6stat.ip6s_nogif++;
245		return IPPROTO_DONE;
246	}
247#ifndef USE_ENCAPCHECK
248	if (!gif_validate6(ip6, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) {
249		m_freem(m);
250		ip6stat.ip6s_nogif++;
251		return IPPROTO_DONE;
252	}
253#endif
254
255	otos = ip6->ip6_flow;
256	m_adj(m, *offp);
257
258	switch (proto) {
259#ifdef INET
260	case IPPROTO_IPV4:
261	    {
262		struct ip *ip;
263		u_int8_t otos8;
264		af = AF_INET;
265		otos8 = (ntohl(otos) >> 20) & 0xff;
266		if (m->m_len < sizeof(*ip)) {
267			m = m_pullup(m, sizeof(*ip));
268			if (!m)
269				return IPPROTO_DONE;
270		}
271		ip = mtod(m, struct ip *);
272		if (gifp->if_flags & IFF_LINK1)
273			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
274		else
275			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
276		break;
277	    }
278#endif /* INET */
279#ifdef INET6
280	case IPPROTO_IPV6:
281	    {
282		struct ip6_hdr *ip6;
283		af = AF_INET6;
284		if (m->m_len < sizeof(*ip6)) {
285			m = m_pullup(m, sizeof(*ip6));
286			if (!m)
287				return IPPROTO_DONE;
288		}
289		ip6 = mtod(m, struct ip6_hdr *);
290		if (gifp->if_flags & IFF_LINK1)
291			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
292		else
293			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
294		break;
295	    }
296#endif
297#ifdef ISO
298	case IPPROTO_EON:
299		af = AF_ISO;
300		break;
301#endif
302	default:
303		ip6stat.ip6s_nogif++;
304		m_freem(m);
305		return IPPROTO_DONE;
306	}
307
308	gif_input(m, af, gifp);
309	return IPPROTO_DONE;
310}
311
312/*
313 * validate outer address.
314 */
315static int
316gif_validate6(ip6, sc, ifp)
317	const struct ip6_hdr *ip6;
318	struct gif_softc *sc;
319	struct ifnet *ifp;
320{
321	struct sockaddr_in6 *src, *dst;
322
323	src = (struct sockaddr_in6 *)sc->gif_psrc;
324	dst = (struct sockaddr_in6 *)sc->gif_pdst;
325
326	/* check for address match */
327	if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
328	    !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
329		return 0;
330
331	/* martian filters on outer source - done in ip6_input */
332
333	/* ingress filters on outer source */
334	if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
335		struct sockaddr_in6 sin6;
336		struct rtentry *rt;
337
338		bzero(&sin6, sizeof(sin6));
339		sin6.sin6_family = AF_INET6;
340		sin6.sin6_len = sizeof(struct sockaddr_in6);
341		sin6.sin6_addr = ip6->ip6_src;
342		/* XXX scopeid */
343		rt = rtalloc1((struct sockaddr *)&sin6, 0);
344		if (!rt || rt->rt_ifp != ifp) {
345#if 0
346			log(LOG_WARNING, "%s: packet from %s dropped "
347			    "due to ingress filter\n", if_name(&sc->gif_if),
348			    ip6_sprintf(&sin6.sin6_addr));
349#endif
350			if (rt)
351				rtfree(rt);
352			return 0;
353		}
354		rtfree(rt);
355	}
356
357	return 128 * 2;
358}
359
360/*
361 * we know that we are in IFF_UP, outer address available, and outer family
362 * matched the physical addr family.  see gif_encapcheck().
363 */
364int
365gif_encapcheck6(m, off, proto, arg)
366	const struct mbuf *m;
367	int off;
368	int proto;
369	void *arg;
370{
371	struct ip6_hdr ip6;
372	struct gif_softc *sc;
373	struct ifnet *ifp;
374
375	/* sanity check done in caller */
376	sc = (struct gif_softc *)arg;
377
378	/* LINTED const cast */
379	m_copydata((struct mbuf *)m, 0, sizeof(ip6), (caddr_t)&ip6);
380	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
381
382	return gif_validate6(&ip6, sc, ifp);
383}
384
385int
386in6_gif_attach(sc)
387	struct gif_softc *sc;
388{
389#ifndef USE_ENCAPCHECK
390	struct sockaddr_in6 mask6;
391
392	bzero(&mask6, sizeof(mask6));
393	mask6.sin6_len = sizeof(struct sockaddr_in6);
394	mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] =
395	    mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;
396
397	if (!sc->gif_psrc || !sc->gif_pdst)
398		return EINVAL;
399	sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc,
400	    (struct sockaddr *)&mask6, sc->gif_pdst, (struct sockaddr *)&mask6,
401	    (struct protosw *)&in6_gif_protosw, sc);
402#else
403	sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
404	    (struct protosw *)&in6_gif_protosw, sc);
405#endif
406	if (sc->encap_cookie6 == NULL)
407		return EEXIST;
408	return 0;
409}
410
411int
412in6_gif_detach(sc)
413	struct gif_softc *sc;
414{
415	int error;
416
417	error = encap_detach(sc->encap_cookie6);
418	if (error == 0)
419		sc->encap_cookie6 = NULL;
420	return error;
421}
422
423void
424in6_gif_ctlinput(cmd, sa, d)
425	int cmd;
426	struct sockaddr *sa;
427	void *d;
428{
429	struct gif_softc *sc;
430	struct ip6ctlparam *ip6cp = NULL;
431	struct mbuf *m;
432	struct ip6_hdr *ip6;
433	int off;
434	void *cmdarg;
435	const struct sockaddr_in6 *sa6_src = NULL;
436	struct sockaddr_in6 *dst6;
437
438	if (sa->sa_family != AF_INET6 ||
439	    sa->sa_len != sizeof(struct sockaddr_in6))
440		return;
441
442	if ((unsigned)cmd >= PRC_NCMDS)
443		return;
444	if (cmd == PRC_HOSTDEAD)
445		d = NULL;
446	else if (inet6ctlerrmap[cmd] == 0)
447		return;
448
449	/* if the parameter is from icmp6, decode it. */
450	if (d != NULL) {
451		ip6cp = (struct ip6ctlparam *)d;
452		m = ip6cp->ip6c_m;
453		ip6 = ip6cp->ip6c_ip6;
454		off = ip6cp->ip6c_off;
455		cmdarg = ip6cp->ip6c_cmdarg;
456		sa6_src = ip6cp->ip6c_src;
457	} else {
458		m = NULL;
459		ip6 = NULL;
460		cmdarg = NULL;
461		sa6_src = &sa6_any;
462	}
463
464	if (!ip6)
465		return;
466
467	/*
468	 * for now we don't care which type it was, just flush the route cache.
469	 * XXX slow.  sc (or sc->encap_cookie6) should be passed from
470	 * ip_encap.c.
471	 */
472	for (sc = LIST_FIRST(&gif_softc_list); sc;
473	     sc = LIST_NEXT(sc, gif_list)) {
474		if ((sc->gif_if.if_flags & IFF_RUNNING) == 0)
475			continue;
476		if (sc->gif_psrc->sa_family != AF_INET6)
477			continue;
478		if (!sc->gif_ro6.ro_rt)
479			continue;
480
481		dst6 = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
482		/* XXX scope */
483		if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr)) {
484			/* flush route cache */
485			RTFREE(sc->gif_ro6.ro_rt);
486			sc->gif_ro6.ro_rt = NULL;
487		}
488	}
489}
490