xref: /netbsd/sys/netinet6/in6_gif.c (revision 6550d01e) 
1 /*	$NetBSD: in6_gif.c,v 1.58 2009/03/14 14:46:10 dsl 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 1.58 2009/03/14 14:46:10 dsl 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(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 = ifp->if_softc;
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, NULL, NULL, NULL);
205 #else
206 	error = ip6_output(m, 0, &sc->gif_ro, 0, NULL, NULL, NULL);
207 #endif
208 
209 	return (error);
210 }
211 
212 int
213 in6_gif_input(struct mbuf **mp, int *offp, int proto)
214 {
215 	struct mbuf *m = *mp;
216 	struct ifnet *gifp = NULL;
217 	struct ip6_hdr *ip6;
218 	int af = 0;
219 	u_int32_t otos;
220 
221 	ip6 = mtod(m, struct ip6_hdr *);
222 
223 	gifp = (struct ifnet *)encap_getarg(m);
224 
225 	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
226 		m_freem(m);
227 		IP6_STATINC(IP6_STAT_NOGIF);
228 		return IPPROTO_DONE;
229 	}
230 #ifndef GIF_ENCAPCHECK
231 	if (!gif_validate6(ip6, gifp->if_softc, m->m_pkthdr.rcvif)) {
232 		m_freem(m);
233 		IP6_STATINC(IP6_STAT_NOGIF);
234 		return IPPROTO_DONE;
235 	}
236 #endif
237 
238 	otos = ip6->ip6_flow;
239 	m_adj(m, *offp);
240 
241 	switch (proto) {
242 #ifdef INET
243 	case IPPROTO_IPV4:
244 	    {
245 		struct ip *ip;
246 		u_int8_t otos8;
247 		af = AF_INET;
248 		otos8 = (ntohl(otos) >> 20) & 0xff;
249 		if (m->m_len < sizeof(*ip)) {
250 			m = m_pullup(m, sizeof(*ip));
251 			if (!m)
252 				return IPPROTO_DONE;
253 		}
254 		ip = mtod(m, struct ip *);
255 		if (gifp->if_flags & IFF_LINK1)
256 			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
257 		else
258 			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
259 		break;
260 	    }
261 #endif /* INET */
262 #ifdef INET6
263 	case IPPROTO_IPV6:
264 	    {
265 		struct ip6_hdr *ip6x;
266 		af = AF_INET6;
267 		if (m->m_len < sizeof(*ip6x)) {
268 			m = m_pullup(m, sizeof(*ip6x));
269 			if (!m)
270 				return IPPROTO_DONE;
271 		}
272 		ip6x = mtod(m, struct ip6_hdr *);
273 		if (gifp->if_flags & IFF_LINK1)
274 			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow);
275 		else
276 			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow);
277 		break;
278 	    }
279 #endif
280 #ifdef ISO
281 	case IPPROTO_EON:
282 		af = AF_ISO;
283 		break;
284 #endif
285 	default:
286 		IP6_STATINC(IP6_STAT_NOGIF);
287 		m_freem(m);
288 		return IPPROTO_DONE;
289 	}
290 
291 	gif_input(m, af, gifp);
292 	return IPPROTO_DONE;
293 }
294 
295 /*
296  * validate outer address.
297  */
298 static int
299 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
300 	struct ifnet *ifp)
301 {
302 	const struct sockaddr_in6 *src, *dst;
303 
304 	src = (struct sockaddr_in6 *)sc->gif_psrc;
305 	dst = (struct sockaddr_in6 *)sc->gif_pdst;
306 
307 	/* check for address match */
308 	if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
309 	    !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
310 		return 0;
311 
312 	/* martian filters on outer source - done in ip6_input */
313 
314 	/* ingress filters on outer source */
315 	if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
316 		union {
317 			struct sockaddr sa;
318 			struct sockaddr_in6 sin6;
319 		} u;
320 		struct rtentry *rt;
321 
322 		/* XXX scopeid */
323 		sockaddr_in6_init(&u.sin6, &ip6->ip6_src, 0, 0, 0);
324 		rt = rtalloc1(&u.sa, 0);
325 		if (rt == NULL || rt->rt_ifp != ifp) {
326 #if 0
327 			log(LOG_WARNING, "%s: packet from %s dropped "
328 			    "due to ingress filter\n", if_name(&sc->gif_if),
329 			    ip6_sprintf(&u.sin6.sin6_addr));
330 #endif
331 			if (rt != NULL)
332 				rtfree(rt);
333 			return 0;
334 		}
335 		rtfree(rt);
336 	}
337 
338 	return 128 * 2;
339 }
340 
341 #ifdef GIF_ENCAPCHECK
342 /*
343  * we know that we are in IFF_UP, outer address available, and outer family
344  * matched the physical addr family.  see gif_encapcheck().
345  */
346 int
347 gif_encapcheck6(struct mbuf *m, int off, int proto, void *arg)
348 {
349 	struct ip6_hdr ip6;
350 	struct gif_softc *sc;
351 	struct ifnet *ifp;
352 
353 	/* sanity check done in caller */
354 	sc = arg;
355 
356 	m_copydata(m, 0, sizeof(ip6), (void *)&ip6);
357 	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
358 
359 	return gif_validate6(&ip6, sc, ifp);
360 }
361 #endif
362 
363 int
364 in6_gif_attach(struct gif_softc *sc)
365 {
366 #ifndef GIF_ENCAPCHECK
367 	struct sockaddr_in6 mask6;
368 
369 	memset(&mask6, 0, sizeof(mask6));
370 	mask6.sin6_len = sizeof(struct sockaddr_in6);
371 	mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] =
372 	    mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;
373 
374 	if (!sc->gif_psrc || !sc->gif_pdst)
375 		return EINVAL;
376 	sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc,
377 	    (struct sockaddr *)&mask6, sc->gif_pdst, (struct sockaddr *)&mask6,
378 	    (const void *)&in6_gif_protosw, sc);
379 #else
380 	sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
381 	    (struct protosw *)&in6_gif_protosw, sc);
382 #endif
383 	if (sc->encap_cookie6 == NULL)
384 		return EEXIST;
385 	return 0;
386 }
387 
388 int
389 in6_gif_detach(struct gif_softc *sc)
390 {
391 	int error;
392 
393 	error = encap_detach(sc->encap_cookie6);
394 	if (error == 0)
395 		sc->encap_cookie6 = NULL;
396 
397 	rtcache_free(&sc->gif_ro);
398 
399 	return error;
400 }
401 
402 void *
403 in6_gif_ctlinput(int cmd, const struct sockaddr *sa, void *d)
404 {
405 	struct gif_softc *sc;
406 	struct ip6ctlparam *ip6cp = NULL;
407 	struct ip6_hdr *ip6;
408 	const struct sockaddr_in6 *dst6;
409 
410 	if (sa->sa_family != AF_INET6 ||
411 	    sa->sa_len != sizeof(struct sockaddr_in6))
412 		return NULL;
413 
414 	if ((unsigned)cmd >= PRC_NCMDS)
415 		return NULL;
416 	if (cmd == PRC_HOSTDEAD)
417 		d = NULL;
418 	else if (inet6ctlerrmap[cmd] == 0)
419 		return NULL;
420 
421 	/* if the parameter is from icmp6, decode it. */
422 	if (d != NULL) {
423 		ip6cp = (struct ip6ctlparam *)d;
424 		ip6 = ip6cp->ip6c_ip6;
425 	} else {
426 		ip6 = NULL;
427 	}
428 
429 	if (!ip6)
430 		return NULL;
431 
432 	/*
433 	 * for now we don't care which type it was, just flush the route cache.
434 	 * XXX slow.  sc (or sc->encap_cookie6) should be passed from
435 	 * ip_encap.c.
436 	 */
437 	LIST_FOREACH(sc, &gif_softc_list, gif_list) {
438 		if ((sc->gif_if.if_flags & IFF_RUNNING) == 0)
439 			continue;
440 		if (sc->gif_psrc->sa_family != AF_INET6)
441 			continue;
442 
443 		dst6 = satocsin6(rtcache_getdst(&sc->gif_ro));
444 		/* XXX scope */
445 		if (dst6 == NULL)
446 			;
447 		else if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr))
448 			rtcache_free(&sc->gif_ro);
449 	}
450 
451 	return NULL;
452 }
453 
454 PR_WRAP_CTLINPUT(in6_gif_ctlinput)
455 PR_WRAP_CTLOUTPUT(rip6_ctloutput)
456 PR_WRAP_USRREQ(rip6_usrreq)
457 
458 #define	in6_gif_ctlinput	in6_gif_ctlinput_wrapper
459 #define	rip6_ctloutput		rip6_ctloutput_wrapper
460 #define	rip6_usrreq		rip6_usrreq_wrapper
461 
462 extern struct domain inet6domain;
463 const struct ip6protosw in6_gif_protosw =
464 { SOCK_RAW,	&inet6domain,	0/* IPPROTO_IPV[46] */,	PR_ATOMIC|PR_ADDR,
465   in6_gif_input, rip6_output,	in6_gif_ctlinput, rip6_ctloutput,
466   rip6_usrreq,
467   0,            0,              0,              0,
468 };
469