xref: /netbsd-src/sys/netinet6/in6_gif.c (revision 2e2322c9c07009df921d11b1268f8506affbb8ba) 
1 /*	$NetBSD: in6_gif.c,v 1.82 2016/12/14 11:19:15 knakahara 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 1.82 2016/12/14 11:19:15 knakahara Exp $");
35 
36 #ifdef _KERNEL_OPT
37 #include "opt_inet.h"
38 #endif
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/mbuf.h>
45 #include <sys/errno.h>
46 #include <sys/ioctl.h>
47 #include <sys/queue.h>
48 #include <sys/syslog.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> /* for struct ip6ctlparam */
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 static const struct encapsw in6_gif_encapsw;
80 
81 /*
82  * family - family of the packet to be encapsulate.
83  */
84 
85 int
86 in6_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
87 {
88 	struct rtentry *rt;
89 	struct route *ro;
90 	struct gif_softc *sc = ifp->if_softc;
91 	struct sockaddr_in6 *sin6_src = satosin6(sc->gif_psrc);
92 	struct sockaddr_in6 *sin6_dst = satosin6(sc->gif_pdst);
93 	struct ip6_hdr *ip6;
94 	int proto, error;
95 	u_int8_t itos, otos;
96 	union {
97 		struct sockaddr		dst;
98 		struct sockaddr_in6	dst6;
99 	} u;
100 
101 	if (sin6_src == NULL || sin6_dst == NULL ||
102 	    sin6_src->sin6_family != AF_INET6 ||
103 	    sin6_dst->sin6_family != AF_INET6) {
104 		m_freem(m);
105 		return EAFNOSUPPORT;
106 	}
107 
108 	switch (family) {
109 #ifdef INET
110 	case AF_INET:
111 	    {
112 		struct ip *ip;
113 
114 		proto = IPPROTO_IPV4;
115 		if (m->m_len < sizeof(*ip)) {
116 			m = m_pullup(m, sizeof(*ip));
117 			if (!m)
118 				return ENOBUFS;
119 		}
120 		ip = mtod(m, struct ip *);
121 		itos = ip->ip_tos;
122 		break;
123 	    }
124 #endif
125 #ifdef INET6
126 	case AF_INET6:
127 	    {
128 		proto = IPPROTO_IPV6;
129 		if (m->m_len < sizeof(*ip6)) {
130 			m = m_pullup(m, sizeof(*ip6));
131 			if (!m)
132 				return ENOBUFS;
133 		}
134 		ip6 = mtod(m, struct ip6_hdr *);
135 		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
136 		break;
137 	    }
138 #endif
139 	default:
140 #ifdef DEBUG
141 		printf("in6_gif_output: warning: unknown family %d passed\n",
142 			family);
143 #endif
144 		m_freem(m);
145 		return EAFNOSUPPORT;
146 	}
147 
148 	/* prepend new IP header */
149 	M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
150 	if (m && m->m_len < sizeof(struct ip6_hdr))
151 		m = m_pullup(m, sizeof(struct ip6_hdr));
152 	if (m == NULL)
153 		return ENOBUFS;
154 
155 	ip6 = mtod(m, struct ip6_hdr *);
156 	ip6->ip6_flow	= 0;
157 	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
158 	ip6->ip6_vfc	|= IPV6_VERSION;
159 #if 0	/* ip6->ip6_plen will be filled by ip6_output */
160 	ip6->ip6_plen	= htons((u_int16_t)m->m_pkthdr.len);
161 #endif
162 	ip6->ip6_nxt	= proto;
163 	ip6->ip6_hlim	= ip6_gif_hlim;
164 	ip6->ip6_src	= sin6_src->sin6_addr;
165 	/* bidirectional configured tunnel mode */
166 	if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
167 		ip6->ip6_dst = sin6_dst->sin6_addr;
168 	else  {
169 		m_freem(m);
170 		return ENETUNREACH;
171 	}
172 	if (ifp->if_flags & IFF_LINK1)
173 		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
174 	else
175 		ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
176 	ip6->ip6_flow &= ~ntohl(0xff00000);
177 	ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
178 
179 	sockaddr_in6_init(&u.dst6, &sin6_dst->sin6_addr, 0, 0, 0);
180 	ro = percpu_getref(sc->gif_ro_percpu);
181 	rt = rtcache_lookup(ro, &u.dst);
182 	if (rt == NULL) {
183 		percpu_putref(sc->gif_ro_percpu);
184 		m_freem(m);
185 		return ENETUNREACH;
186 	}
187 
188 	/* If the route constitutes infinite encapsulation, punt. */
189 	if (rt->rt_ifp == ifp) {
190 		rtcache_unref(rt, ro);
191 		rtcache_free(ro);
192 		percpu_putref(sc->gif_ro_percpu);
193 		m_freem(m);
194 		return ENETUNREACH;	/* XXX */
195 	}
196 	rtcache_unref(rt, ro);
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, ro, IPV6_MINMTU, NULL, NULL, NULL);
205 #else
206 	error = ip6_output(m, 0, ro, 0, NULL, NULL, NULL);
207 #endif
208 	percpu_putref(sc->gif_ro_percpu);
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|IFF_RUNNING))
226 		!= (IFF_UP|IFF_RUNNING)) {
227 		m_freem(m);
228 		IP6_STATINC(IP6_STAT_NOGIF);
229 		return IPPROTO_DONE;
230 	}
231 #ifndef GIF_ENCAPCHECK
232 	struct gif_softc *sc = (struct gif_softc *)gifp->if_softc;
233 	/* other CPU do delete_tunnel */
234 	if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
235 		m_freem(m);
236 		IP6_STATINC(IP6_STAT_NOGIF);
237 		return IPPROTO_DONE;
238 	}
239 
240 	struct psref psref;
241 	struct ifnet *rcvif = m_get_rcvif_psref(m, &psref);
242 	if (rcvif == NULL || !gif_validate6(ip6, sc, rcvif)) {
243 		m_put_rcvif_psref(rcvif, &psref);
244 		m_freem(m);
245 		IP6_STATINC(IP6_STAT_NOGIF);
246 		return IPPROTO_DONE;
247 	}
248 	m_put_rcvif_psref(rcvif, &psref);
249 #endif
250 
251 	otos = ip6->ip6_flow;
252 	m_adj(m, *offp);
253 
254 	switch (proto) {
255 #ifdef INET
256 	case IPPROTO_IPV4:
257 	    {
258 		struct ip *ip;
259 		u_int8_t otos8;
260 		af = AF_INET;
261 		otos8 = (ntohl(otos) >> 20) & 0xff;
262 		if (m->m_len < sizeof(*ip)) {
263 			m = m_pullup(m, sizeof(*ip));
264 			if (!m)
265 				return IPPROTO_DONE;
266 		}
267 		ip = mtod(m, struct ip *);
268 		if (gifp->if_flags & IFF_LINK1)
269 			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
270 		else
271 			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
272 		break;
273 	    }
274 #endif /* INET */
275 #ifdef INET6
276 	case IPPROTO_IPV6:
277 	    {
278 		struct ip6_hdr *ip6x;
279 		af = AF_INET6;
280 		if (m->m_len < sizeof(*ip6x)) {
281 			m = m_pullup(m, sizeof(*ip6x));
282 			if (!m)
283 				return IPPROTO_DONE;
284 		}
285 		ip6x = mtod(m, struct ip6_hdr *);
286 		if (gifp->if_flags & IFF_LINK1)
287 			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow);
288 		else
289 			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow);
290 		break;
291 	    }
292 #endif
293 	default:
294 		IP6_STATINC(IP6_STAT_NOGIF);
295 		m_freem(m);
296 		return IPPROTO_DONE;
297 	}
298 
299 	gif_input(m, af, gifp);
300 	return IPPROTO_DONE;
301 }
302 
303 /*
304  * validate outer address.
305  */
306 static int
307 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
308 	struct ifnet *ifp)
309 {
310 	const struct sockaddr_in6 *src, *dst;
311 
312 	src = satosin6(sc->gif_psrc);
313 	dst = satosin6(sc->gif_pdst);
314 
315 	/* check for address match */
316 	if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
317 	    !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
318 		return 0;
319 
320 	/* martian filters on outer source - done in ip6_input */
321 
322 	/* ingress filters on outer source */
323 	if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
324 		union {
325 			struct sockaddr sa;
326 			struct sockaddr_in6 sin6;
327 		} u;
328 		struct rtentry *rt;
329 
330 		/* XXX scopeid */
331 		sockaddr_in6_init(&u.sin6, &ip6->ip6_src, 0, 0, 0);
332 		rt = rtalloc1(&u.sa, 0);
333 		if (rt == NULL || rt->rt_ifp != ifp) {
334 #if 0
335 			log(LOG_WARNING, "%s: packet from %s dropped "
336 			    "due to ingress filter\n", if_name(&sc->gif_if),
337 			    ip6_sprintf(&u.sin6.sin6_addr));
338 #endif
339 			if (rt != NULL)
340 				rt_unref(rt);
341 			return 0;
342 		}
343 		rt_unref(rt);
344 	}
345 
346 	return 128 * 2;
347 }
348 
349 #ifdef GIF_ENCAPCHECK
350 /*
351  * we know that we are in IFF_UP, outer address available, and outer family
352  * matched the physical addr family.  see gif_encapcheck().
353  */
354 int
355 gif_encapcheck6(struct mbuf *m, int off, int proto, void *arg)
356 {
357 	struct ip6_hdr ip6;
358 	struct gif_softc *sc;
359 	struct ifnet *ifp = NULL;
360 	int r;
361 	struct psref psref;
362 
363 	/* sanity check done in caller */
364 	sc = arg;
365 
366 	m_copydata(m, 0, sizeof(ip6), (void *)&ip6);
367 	if ((m->m_flags & M_PKTHDR) != 0)
368 		ifp = m_get_rcvif_psref(m, &psref);
369 
370 	r = gif_validate6(&ip6, sc, ifp);
371 
372 	m_put_rcvif_psref(ifp, &psref);
373 	return r;
374 }
375 #endif
376 
377 int
378 in6_gif_attach(struct gif_softc *sc)
379 {
380 #ifndef GIF_ENCAPCHECK
381 	struct sockaddr_in6 mask6;
382 
383 	memset(&mask6, 0, sizeof(mask6));
384 	mask6.sin6_len = sizeof(struct sockaddr_in6);
385 	mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] =
386 	    mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;
387 
388 	if (!sc->gif_psrc || !sc->gif_pdst)
389 		return EINVAL;
390 	sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc,
391 	    sin6tosa(&mask6), sc->gif_pdst, sin6tosa(&mask6),
392 	    (const void *)&in6_gif_encapsw, sc);
393 #else
394 	sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
395 	    &in6_gif_encapsw, sc);
396 #endif
397 	if (sc->encap_cookie6 == NULL)
398 		return EEXIST;
399 	return 0;
400 }
401 
402 int
403 in6_gif_detach(struct gif_softc *sc)
404 {
405 	int error;
406 
407 	error = in6_gif_pause(sc);
408 
409 	percpu_foreach(sc->gif_ro_percpu, gif_rtcache_free_pc, NULL);
410 
411 	return error;
412 }
413 
414 int
415 in6_gif_pause(struct gif_softc *sc)
416 {
417 	int error;
418 
419 	error = encap_detach(sc->encap_cookie6);
420 	if (error == 0)
421 		sc->encap_cookie6 = NULL;
422 
423 	return error;
424 }
425 
426 void *
427 in6_gif_ctlinput(int cmd, const struct sockaddr *sa, void *d, void *eparg)
428 {
429 	struct gif_softc *sc = eparg;
430 	struct ip6ctlparam *ip6cp = NULL;
431 	struct ip6_hdr *ip6;
432 	const struct sockaddr_in6 *dst6;
433 	struct route *ro;
434 
435 	if (sa->sa_family != AF_INET6 ||
436 	    sa->sa_len != sizeof(struct sockaddr_in6))
437 		return NULL;
438 
439 	if ((unsigned)cmd >= PRC_NCMDS)
440 		return NULL;
441 	if (cmd == PRC_HOSTDEAD)
442 		d = NULL;
443 	else if (inet6ctlerrmap[cmd] == 0)
444 		return NULL;
445 
446 	/* if the parameter is from icmp6, decode it. */
447 	if (d != NULL) {
448 		ip6cp = (struct ip6ctlparam *)d;
449 		ip6 = ip6cp->ip6c_ip6;
450 	} else {
451 		ip6 = NULL;
452 	}
453 
454 	if (!ip6)
455 		return NULL;
456 
457 	if ((sc->gif_if.if_flags & IFF_RUNNING) == 0)
458 		return NULL;
459 	if (sc->gif_psrc->sa_family != AF_INET6)
460 		return NULL;
461 
462 	ro = percpu_getref(sc->gif_ro_percpu);
463 	dst6 = satocsin6(rtcache_getdst(ro));
464 	/* XXX scope */
465 	if (dst6 == NULL)
466 		;
467 	else if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr))
468 		rtcache_free(ro);
469 
470 	percpu_putref(sc->gif_ro_percpu);
471 	return NULL;
472 }
473 
474 ENCAP_PR_WRAP_CTLINPUT(in6_gif_ctlinput)
475 #define	in6_gif_ctlinput	in6_gif_ctlinput_wrapper
476 
477 static const struct encapsw in6_gif_encapsw = {
478 	.encapsw6 = {
479 		.pr_input	= in6_gif_input,
480 		.pr_ctlinput	= in6_gif_ctlinput,
481 	}
482 };
483