xref: /netbsd-src/sys/netinet6/in6_gif.c (revision 4b71a66d0f279143147d63ebfcfd8a59499a3684) 
1 /*	$NetBSD: in6_gif.c,v 1.56 2008/04/24 11:38:38 ad 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 1.56 2008/04/24 11:38:38 ad 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/ip6_private.h>
64 #include <netinet6/in6_gif.h>
65 #include <netinet6/in6_var.h>
66 #endif
67 #include <netinet6/ip6protosw.h>
68 #include <netinet/ip_ecn.h>
69 
70 #include <net/if_gif.h>
71 
72 #include <net/net_osdep.h>
73 
74 static int gif_validate6 __P((const struct ip6_hdr *, struct gif_softc *,
75 	struct ifnet *));
76 
77 int	ip6_gif_hlim = GIF_HLIM;
78 
79 extern LIST_HEAD(, gif_softc) gif_softc_list;
80 
81 extern const struct ip6protosw in6_gif_protosw;
82 
83 /*
84  * family - family of the packet to be encapsulate.
85  */
86 
87 int
88 in6_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
89 {
90 	struct rtentry *rt;
91 	struct gif_softc *sc = (struct gif_softc*)ifp;
92 	struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
93 	struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
94 	struct ip6_hdr *ip6;
95 	int proto, error;
96 	u_int8_t itos, otos;
97 	union {
98 		struct sockaddr		dst;
99 		struct sockaddr_in6	dst6;
100 	} u;
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 	sockaddr_in6_init(&u.dst6, &sin6_dst->sin6_addr, 0, 0, 0);
187 	if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) {
188 		m_freem(m);
189 		return ENETUNREACH;
190 	}
191 
192 	/* If the route constitutes infinite encapsulation, punt. */
193 	if (rt->rt_ifp == ifp) {
194 		m_freem(m);
195 		return ENETUNREACH;	/* XXX */
196 	}
197 
198 #ifdef IPV6_MINMTU
199 	/*
200 	 * force fragmentation to minimum MTU, to avoid path MTU discovery.
201 	 * it is too painful to ask for resend of inner packet, to achieve
202 	 * path MTU discovery for encapsulated packets.
203 	 */
204 	error = ip6_output(m, 0, &sc->gif_ro, IPV6_MINMTU,
205 		    (struct ip6_moptions *)NULL, (struct socket *)NULL, NULL);
206 #else
207 	error = ip6_output(m, 0, &sc->gif_ro, 0,
208 		    (struct ip6_moptions *)NULL, (struct socket *)NULL, NULL);
209 #endif
210 
211 	return (error);
212 }
213 
214 int in6_gif_input(struct mbuf **mp, int *offp, int proto)
215 {
216 	struct mbuf *m = *mp;
217 	struct ifnet *gifp = NULL;
218 	struct ip6_hdr *ip6;
219 	int af = 0;
220 	u_int32_t otos;
221 
222 	ip6 = mtod(m, struct ip6_hdr *);
223 
224 	gifp = (struct ifnet *)encap_getarg(m);
225 
226 	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
227 		m_freem(m);
228 		IP6_STATINC(IP6_STAT_NOGIF);
229 		return IPPROTO_DONE;
230 	}
231 #ifndef GIF_ENCAPCHECK
232 	if (!gif_validate6(ip6, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) {
233 		m_freem(m);
234 		IP6_STATINC(IP6_STAT_NOGIF);
235 		return IPPROTO_DONE;
236 	}
237 #endif
238 
239 	otos = ip6->ip6_flow;
240 	m_adj(m, *offp);
241 
242 	switch (proto) {
243 #ifdef INET
244 	case IPPROTO_IPV4:
245 	    {
246 		struct ip *ip;
247 		u_int8_t otos8;
248 		af = AF_INET;
249 		otos8 = (ntohl(otos) >> 20) & 0xff;
250 		if (m->m_len < sizeof(*ip)) {
251 			m = m_pullup(m, sizeof(*ip));
252 			if (!m)
253 				return IPPROTO_DONE;
254 		}
255 		ip = mtod(m, struct ip *);
256 		if (gifp->if_flags & IFF_LINK1)
257 			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
258 		else
259 			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
260 		break;
261 	    }
262 #endif /* INET */
263 #ifdef INET6
264 	case IPPROTO_IPV6:
265 	    {
266 		struct ip6_hdr *ip6x;
267 		af = AF_INET6;
268 		if (m->m_len < sizeof(*ip6x)) {
269 			m = m_pullup(m, sizeof(*ip6x));
270 			if (!m)
271 				return IPPROTO_DONE;
272 		}
273 		ip6x = mtod(m, struct ip6_hdr *);
274 		if (gifp->if_flags & IFF_LINK1)
275 			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow);
276 		else
277 			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow);
278 		break;
279 	    }
280 #endif
281 #ifdef ISO
282 	case IPPROTO_EON:
283 		af = AF_ISO;
284 		break;
285 #endif
286 	default:
287 		IP6_STATINC(IP6_STAT_NOGIF);
288 		m_freem(m);
289 		return IPPROTO_DONE;
290 	}
291 
292 	gif_input(m, af, gifp);
293 	return IPPROTO_DONE;
294 }
295 
296 /*
297  * validate outer address.
298  */
299 static int
300 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
301 	struct ifnet *ifp)
302 {
303 	const struct sockaddr_in6 *src, *dst;
304 
305 	src = (struct sockaddr_in6 *)sc->gif_psrc;
306 	dst = (struct sockaddr_in6 *)sc->gif_pdst;
307 
308 	/* check for address match */
309 	if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
310 	    !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
311 		return 0;
312 
313 	/* martian filters on outer source - done in ip6_input */
314 
315 	/* ingress filters on outer source */
316 	if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
317 		struct sockaddr_in6 sin6;
318 		struct rtentry *rt;
319 
320 		memset(&sin6, 0, sizeof(sin6));
321 		sin6.sin6_family = AF_INET6;
322 		sin6.sin6_len = sizeof(struct sockaddr_in6);
323 		sin6.sin6_addr = ip6->ip6_src;
324 		/* XXX scopeid */
325 		rt = rtalloc1((struct sockaddr *)&sin6, 0);
326 		if (!rt || rt->rt_ifp != ifp) {
327 #if 0
328 			log(LOG_WARNING, "%s: packet from %s dropped "
329 			    "due to ingress filter\n", if_name(&sc->gif_if),
330 			    ip6_sprintf(&sin6.sin6_addr));
331 #endif
332 			if (rt)
333 				rtfree(rt);
334 			return 0;
335 		}
336 		rtfree(rt);
337 	}
338 
339 	return 128 * 2;
340 }
341 
342 #ifdef GIF_ENCAPCHECK
343 /*
344  * we know that we are in IFF_UP, outer address available, and outer family
345  * matched the physical addr family.  see gif_encapcheck().
346  */
347 int
348 gif_encapcheck6(struct mbuf *m, int off, int proto, void *arg)
349 {
350 	struct ip6_hdr ip6;
351 	struct gif_softc *sc;
352 	struct ifnet *ifp;
353 
354 	/* sanity check done in caller */
355 	sc = (struct gif_softc *)arg;
356 
357 	m_copydata(m, 0, sizeof(ip6), (void *)&ip6);
358 	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
359 
360 	return gif_validate6(&ip6, sc, ifp);
361 }
362 #endif
363 
364 int
365 in6_gif_attach(struct gif_softc *sc)
366 {
367 #ifndef GIF_ENCAPCHECK
368 	struct sockaddr_in6 mask6;
369 
370 	bzero(&mask6, sizeof(mask6));
371 	mask6.sin6_len = sizeof(struct sockaddr_in6);
372 	mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] =
373 	    mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;
374 
375 	if (!sc->gif_psrc || !sc->gif_pdst)
376 		return EINVAL;
377 	sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc,
378 	    (struct sockaddr *)&mask6, sc->gif_pdst, (struct sockaddr *)&mask6,
379 	    (const void *)&in6_gif_protosw, sc);
380 #else
381 	sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
382 	    (struct protosw *)&in6_gif_protosw, sc);
383 #endif
384 	if (sc->encap_cookie6 == NULL)
385 		return EEXIST;
386 	return 0;
387 }
388 
389 int
390 in6_gif_detach(struct gif_softc *sc)
391 {
392 	int error;
393 
394 	error = encap_detach(sc->encap_cookie6);
395 	if (error == 0)
396 		sc->encap_cookie6 = NULL;
397 
398 	rtcache_free(&sc->gif_ro);
399 
400 	return error;
401 }
402 
403 void *
404 in6_gif_ctlinput(int cmd, const struct sockaddr *sa, void *d)
405 {
406 	struct gif_softc *sc;
407 	struct ip6ctlparam *ip6cp = NULL;
408 	struct ip6_hdr *ip6;
409 	const struct sockaddr_in6 *dst6;
410 
411 	if (sa->sa_family != AF_INET6 ||
412 	    sa->sa_len != sizeof(struct sockaddr_in6))
413 		return NULL;
414 
415 	if ((unsigned)cmd >= PRC_NCMDS)
416 		return NULL;
417 	if (cmd == PRC_HOSTDEAD)
418 		d = NULL;
419 	else if (inet6ctlerrmap[cmd] == 0)
420 		return NULL;
421 
422 	/* if the parameter is from icmp6, decode it. */
423 	if (d != NULL) {
424 		ip6cp = (struct ip6ctlparam *)d;
425 		ip6 = ip6cp->ip6c_ip6;
426 	} else {
427 		ip6 = NULL;
428 	}
429 
430 	if (!ip6)
431 		return NULL;
432 
433 	/*
434 	 * for now we don't care which type it was, just flush the route cache.
435 	 * XXX slow.  sc (or sc->encap_cookie6) should be passed from
436 	 * ip_encap.c.
437 	 */
438 	LIST_FOREACH(sc, &gif_softc_list, gif_list) {
439 		if ((sc->gif_if.if_flags & IFF_RUNNING) == 0)
440 			continue;
441 		if (sc->gif_psrc->sa_family != AF_INET6)
442 			continue;
443 
444 		dst6 = satocsin6(rtcache_getdst(&sc->gif_ro));
445 		/* XXX scope */
446 		if (dst6 == NULL)
447 			;
448 		else if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr))
449 			rtcache_free(&sc->gif_ro);
450 	}
451 
452 	return NULL;
453 }
454 
455 PR_WRAP_CTLINPUT(in6_gif_ctlinput)
456 PR_WRAP_CTLOUTPUT(rip6_ctloutput)
457 PR_WRAP_USRREQ(rip6_usrreq)
458 
459 #define	in6_gif_ctlinput	in6_gif_ctlinput_wrapper
460 #define	rip6_ctloutput		rip6_ctloutput_wrapper
461 #define	rip6_usrreq		rip6_usrreq_wrapper
462 
463 extern struct domain inet6domain;
464 const struct ip6protosw in6_gif_protosw =
465 { SOCK_RAW,	&inet6domain,	0/* IPPROTO_IPV[46] */,	PR_ATOMIC|PR_ADDR,
466   in6_gif_input, rip6_output,	in6_gif_ctlinput, rip6_ctloutput,
467   rip6_usrreq,
468   0,            0,              0,              0,
469 };
470