in6_gif.c revision 1.47 
1/*	$NetBSD: in6_gif.c,v 1.47 2006/12/15 21:18:54 joerg 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 1.47 2006/12/15 21:18:54 joerg Exp $");
35
36#include "opt_inet.h"
37#include "opt_iso.h"
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/socket.h>
42#include <sys/sockio.h>
43#include <sys/mbuf.h>
44#include <sys/errno.h>
45#include <sys/ioctl.h>
46#include <sys/queue.h>
47#include <sys/syslog.h>
48#include <sys/protosw.h>
49#include <sys/kernel.h>
50
51#include <net/if.h>
52#include <net/route.h>
53
54#include <netinet/in.h>
55#include <netinet/in_systm.h>
56#ifdef INET
57#include <netinet/ip.h>
58#endif
59#include <netinet/ip_encap.h>
60#ifdef INET6
61#include <netinet/ip6.h>
62#include <netinet6/ip6_var.h>
63#include <netinet6/in6_gif.h>
64#include <netinet6/in6_var.h>
65#endif
66#include <netinet6/ip6protosw.h>
67#include <netinet/ip_ecn.h>
68
69#include <net/if_gif.h>
70
71#include <net/net_osdep.h>
72
73static int gif_validate6 __P((const struct ip6_hdr *, struct gif_softc *,
74	struct ifnet *));
75
76int	ip6_gif_hlim = GIF_HLIM;
77
78extern struct domain inet6domain;
79const struct ip6protosw in6_gif_protosw =
80{ SOCK_RAW,	&inet6domain,	0/* IPPROTO_IPV[46] */,	PR_ATOMIC|PR_ADDR,
81  in6_gif_input, rip6_output,	in6_gif_ctlinput, rip6_ctloutput,
82  rip6_usrreq,
83  0,            0,              0,              0,
84};
85
86extern LIST_HEAD(, gif_softc) gif_softc_list;
87
88int
89in6_gif_output(ifp, family, m)
90	struct ifnet *ifp;
91	int family; /* family of the packet to be encapsulate. */
92	struct mbuf *m;
93{
94	struct gif_softc *sc = (struct gif_softc*)ifp;
95	struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
96	struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
97	struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
98	struct ip6_hdr *ip6;
99	int proto, error;
100	u_int8_t itos, otos;
101
102	if (sin6_src == NULL || sin6_dst == NULL ||
103	    sin6_src->sin6_family != AF_INET6 ||
104	    sin6_dst->sin6_family != AF_INET6) {
105		m_freem(m);
106		return EAFNOSUPPORT;
107	}
108
109	switch (family) {
110#ifdef INET
111	case AF_INET:
112	    {
113		struct ip *ip;
114
115		proto = IPPROTO_IPV4;
116		if (m->m_len < sizeof(*ip)) {
117			m = m_pullup(m, sizeof(*ip));
118			if (!m)
119				return ENOBUFS;
120		}
121		ip = mtod(m, struct ip *);
122		itos = ip->ip_tos;
123		break;
124	    }
125#endif
126#ifdef INET6
127	case AF_INET6:
128	    {
129		proto = IPPROTO_IPV6;
130		if (m->m_len < sizeof(*ip6)) {
131			m = m_pullup(m, sizeof(*ip6));
132			if (!m)
133				return ENOBUFS;
134		}
135		ip6 = mtod(m, struct ip6_hdr *);
136		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
137		break;
138	    }
139#endif
140#ifdef ISO
141	case AF_ISO:
142		proto = IPPROTO_EON;
143		itos = 0;
144		break;
145#endif
146	default:
147#ifdef DEBUG
148		printf("in6_gif_output: warning: unknown family %d passed\n",
149			family);
150#endif
151		m_freem(m);
152		return EAFNOSUPPORT;
153	}
154
155	/* prepend new IP header */
156	M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
157	if (m && m->m_len < sizeof(struct ip6_hdr))
158		m = m_pullup(m, sizeof(struct ip6_hdr));
159	if (m == NULL)
160		return ENOBUFS;
161
162	ip6 = mtod(m, struct ip6_hdr *);
163	ip6->ip6_flow	= 0;
164	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
165	ip6->ip6_vfc	|= IPV6_VERSION;
166#if 0	/* ip6->ip6_plen will be filled by ip6_output */
167	ip6->ip6_plen	= htons((u_int16_t)m->m_pkthdr.len);
168#endif
169	ip6->ip6_nxt	= proto;
170	ip6->ip6_hlim	= ip6_gif_hlim;
171	ip6->ip6_src	= sin6_src->sin6_addr;
172	/* bidirectional configured tunnel mode */
173	if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
174		ip6->ip6_dst = sin6_dst->sin6_addr;
175	else  {
176		m_freem(m);
177		return ENETUNREACH;
178	}
179	if (ifp->if_flags & IFF_LINK1)
180		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
181	else
182		ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
183	ip6->ip6_flow &= ~ntohl(0xff00000);
184	ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
185
186	if (dst->sin6_family != sin6_dst->sin6_family ||
187	    !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr))
188		rtcache_free((struct route *)&sc->gif_ro6);
189	else
190		rtcache_check((struct route *)&sc->gif_ro6);
191
192	if (sc->gif_ro6.ro_rt == NULL) {
193		bzero(dst, sizeof(*dst));
194		dst->sin6_family = sin6_dst->sin6_family;
195		dst->sin6_len = sizeof(struct sockaddr_in6);
196		dst->sin6_addr = sin6_dst->sin6_addr;
197		rtcache_init((struct route *)&sc->gif_ro6);
198		if (sc->gif_ro6.ro_rt == NULL) {
199			m_freem(m);
200			return ENETUNREACH;
201		}
202	}
203
204	/* If the route constitutes infinite encapsulation, punt. */
205	if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
206		m_freem(m);
207		return ENETUNREACH;	/* XXX */
208	}
209
210#ifdef IPV6_MINMTU
211	/*
212	 * force fragmentation to minimum MTU, to avoid path MTU discovery.
213	 * it is too painful to ask for resend of inner packet, to achieve
214	 * path MTU discovery for encapsulated packets.
215	 */
216	error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU,
217		    (struct ip6_moptions *)NULL, (struct socket *)NULL, NULL);
218#else
219	error = ip6_output(m, 0, &sc->gif_ro6, 0,
220		    (struct ip6_moptions *)NULL, (struct socket *)NULL, NULL);
221#endif
222
223	return (error);
224}
225
226int in6_gif_input(mp, offp, proto)
227	struct mbuf **mp;
228	int *offp, proto;
229{
230	struct mbuf *m = *mp;
231	struct ifnet *gifp = NULL;
232	struct ip6_hdr *ip6;
233	int af = 0;
234	u_int32_t otos;
235
236	ip6 = mtod(m, struct ip6_hdr *);
237
238	gifp = (struct ifnet *)encap_getarg(m);
239
240	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
241		m_freem(m);
242		ip6stat.ip6s_nogif++;
243		return IPPROTO_DONE;
244	}
245#ifndef GIF_ENCAPCHECK
246	if (!gif_validate6(ip6, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) {
247		m_freem(m);
248		ip6stat.ip6s_nogif++;
249		return IPPROTO_DONE;
250	}
251#endif
252
253	otos = ip6->ip6_flow;
254	m_adj(m, *offp);
255
256	switch (proto) {
257#ifdef INET
258	case IPPROTO_IPV4:
259	    {
260		struct ip *ip;
261		u_int8_t otos8;
262		af = AF_INET;
263		otos8 = (ntohl(otos) >> 20) & 0xff;
264		if (m->m_len < sizeof(*ip)) {
265			m = m_pullup(m, sizeof(*ip));
266			if (!m)
267				return IPPROTO_DONE;
268		}
269		ip = mtod(m, struct ip *);
270		if (gifp->if_flags & IFF_LINK1)
271			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
272		else
273			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
274		break;
275	    }
276#endif /* INET */
277#ifdef INET6
278	case IPPROTO_IPV6:
279	    {
280		struct ip6_hdr *ip6x;
281		af = AF_INET6;
282		if (m->m_len < sizeof(*ip6x)) {
283			m = m_pullup(m, sizeof(*ip6x));
284			if (!m)
285				return IPPROTO_DONE;
286		}
287		ip6x = mtod(m, struct ip6_hdr *);
288		if (gifp->if_flags & IFF_LINK1)
289			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow);
290		else
291			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow);
292		break;
293	    }
294#endif
295#ifdef ISO
296	case IPPROTO_EON:
297		af = AF_ISO;
298		break;
299#endif
300	default:
301		ip6stat.ip6s_nogif++;
302		m_freem(m);
303		return IPPROTO_DONE;
304	}
305
306	gif_input(m, af, gifp);
307	return IPPROTO_DONE;
308}
309
310/*
311 * validate outer address.
312 */
313static int
314gif_validate6(ip6, sc, ifp)
315	const struct ip6_hdr *ip6;
316	struct gif_softc *sc;
317	struct ifnet *ifp;
318{
319	struct sockaddr_in6 *src, *dst;
320
321	src = (struct sockaddr_in6 *)sc->gif_psrc;
322	dst = (struct sockaddr_in6 *)sc->gif_pdst;
323
324	/* check for address match */
325	if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
326	    !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
327		return 0;
328
329	/* martian filters on outer source - done in ip6_input */
330
331	/* ingress filters on outer source */
332	if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
333		struct sockaddr_in6 sin6;
334		struct rtentry *rt;
335
336		bzero(&sin6, sizeof(sin6));
337		sin6.sin6_family = AF_INET6;
338		sin6.sin6_len = sizeof(struct sockaddr_in6);
339		sin6.sin6_addr = ip6->ip6_src;
340		/* XXX scopeid */
341		rt = rtalloc1((struct sockaddr *)&sin6, 0);
342		if (!rt || rt->rt_ifp != ifp) {
343#if 0
344			log(LOG_WARNING, "%s: packet from %s dropped "
345			    "due to ingress filter\n", if_name(&sc->gif_if),
346			    ip6_sprintf(&sin6.sin6_addr));
347#endif
348			if (rt)
349				rtfree(rt);
350			return 0;
351		}
352		rtfree(rt);
353	}
354
355	return 128 * 2;
356}
357
358#ifdef GIF_ENCAPCHECK
359/*
360 * we know that we are in IFF_UP, outer address available, and outer family
361 * matched the physical addr family.  see gif_encapcheck().
362 */
363int
364gif_encapcheck6(m, off, proto, arg)
365	struct mbuf *m;
366	int off;
367	int proto;
368	void *arg;
369{
370	struct ip6_hdr ip6;
371	struct gif_softc *sc;
372	struct ifnet *ifp;
373
374	/* sanity check done in caller */
375	sc = (struct gif_softc *)arg;
376
377	m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
378	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
379
380	return gif_validate6(&ip6, sc, ifp);
381}
382#endif
383
384int
385in6_gif_attach(sc)
386	struct gif_softc *sc;
387{
388#ifndef GIF_ENCAPCHECK
389	struct sockaddr_in6 mask6;
390
391	bzero(&mask6, sizeof(mask6));
392	mask6.sin6_len = sizeof(struct sockaddr_in6);
393	mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] =
394	    mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;
395
396	if (!sc->gif_psrc || !sc->gif_pdst)
397		return EINVAL;
398	sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc,
399	    (struct sockaddr *)&mask6, sc->gif_pdst, (struct sockaddr *)&mask6,
400	    (const void *)&in6_gif_protosw, sc);
401#else
402	sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
403	    (struct protosw *)&in6_gif_protosw, sc);
404#endif
405	if (sc->encap_cookie6 == NULL)
406		return EEXIST;
407	return 0;
408}
409
410int
411in6_gif_detach(sc)
412	struct gif_softc *sc;
413{
414	int error;
415
416	error = encap_detach(sc->encap_cookie6);
417	if (error == 0)
418		sc->encap_cookie6 = NULL;
419
420	rtcache_free((struct route *)&sc->gif_ro6);
421
422	return error;
423}
424
425void
426in6_gif_ctlinput(cmd, sa, d)
427	int cmd;
428	struct sockaddr *sa;
429	void *d;
430{
431	struct gif_softc *sc;
432	struct ip6ctlparam *ip6cp = NULL;
433	struct ip6_hdr *ip6;
434	struct sockaddr_in6 *dst6;
435
436	if (sa->sa_family != AF_INET6 ||
437	    sa->sa_len != sizeof(struct sockaddr_in6))
438		return;
439
440	if ((unsigned)cmd >= PRC_NCMDS)
441		return;
442	if (cmd == PRC_HOSTDEAD)
443		d = NULL;
444	else if (inet6ctlerrmap[cmd] == 0)
445		return;
446
447	/* if the parameter is from icmp6, decode it. */
448	if (d != NULL) {
449		ip6cp = (struct ip6ctlparam *)d;
450		ip6 = ip6cp->ip6c_ip6;
451	} else {
452		ip6 = NULL;
453	}
454
455	if (!ip6)
456		return;
457
458	/*
459	 * for now we don't care which type it was, just flush the route cache.
460	 * XXX slow.  sc (or sc->encap_cookie6) should be passed from
461	 * ip_encap.c.
462	 */
463	for (sc = LIST_FIRST(&gif_softc_list); sc;
464	     sc = LIST_NEXT(sc, gif_list)) {
465		if ((sc->gif_if.if_flags & IFF_RUNNING) == 0)
466			continue;
467		if (sc->gif_psrc->sa_family != AF_INET6)
468			continue;
469		if (sc->gif_ro6.ro_rt == NULL)
470			continue;
471
472		dst6 = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
473		/* XXX scope */
474		if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr))
475			rtcache_free((struct route *)&sc->gif_ro6);
476	}
477}
478