xref: /netbsd-src/sys/netinet6/in6_gif.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c) 
1 /*	$NetBSD: in6_gif.c,v 1.93 2018/05/01 07:21:39 maxv 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 1.93 2018/05/01 07:21:39 maxv 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 static int gif_validate6(const struct ip6_hdr *, struct gif_variant *,
73 	struct ifnet *);
74 
75 int	ip6_gif_hlim = GIF_HLIM;
76 
77 static const struct encapsw in6_gif_encapsw;
78 
79 /*
80  * family - family of the packet to be encapsulate.
81  */
82 
83 static int
84 in6_gif_output(struct gif_variant *var, int family, struct mbuf *m)
85 {
86 	struct rtentry *rt;
87 	struct route *ro;
88 	struct gif_ro *gro;
89 	struct gif_softc *sc;
90 	struct sockaddr_in6 *sin6_src;
91 	struct sockaddr_in6 *sin6_dst;
92 	struct ifnet *ifp;
93 	struct ip6_hdr *ip6;
94 	int proto, error;
95 	u_int8_t itos, otos;
96 
97 	KASSERT(gif_heldref_variant(var));
98 
99 	sin6_src = satosin6(var->gv_psrc);
100 	sin6_dst = satosin6(var->gv_pdst);
101 	ifp = &var->gv_softc->gif_if;
102 
103 	if (sin6_src == NULL || sin6_dst == NULL ||
104 	    sin6_src->sin6_family != AF_INET6 ||
105 	    sin6_dst->sin6_family != AF_INET6) {
106 		m_freem(m);
107 		return EAFNOSUPPORT;
108 	}
109 
110 	switch (family) {
111 #ifdef INET
112 	case AF_INET:
113 	    {
114 		struct ip *ip;
115 
116 		proto = IPPROTO_IPV4;
117 		if (m->m_len < sizeof(*ip)) {
118 			m = m_pullup(m, sizeof(*ip));
119 			if (!m)
120 				return ENOBUFS;
121 		}
122 		ip = mtod(m, struct ip *);
123 		itos = ip->ip_tos;
124 		break;
125 	    }
126 #endif
127 #ifdef INET6
128 	case AF_INET6:
129 	    {
130 		proto = IPPROTO_IPV6;
131 		if (m->m_len < sizeof(*ip6)) {
132 			m = m_pullup(m, sizeof(*ip6));
133 			if (!m)
134 				return ENOBUFS;
135 		}
136 		ip6 = mtod(m, struct ip6_hdr *);
137 		itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
138 		break;
139 	    }
140 #endif
141 	default:
142 #ifdef DEBUG
143 		printf("in6_gif_output: warning: unknown family %d passed\n",
144 			family);
145 #endif
146 		m_freem(m);
147 		return EAFNOSUPPORT;
148 	}
149 
150 	/* prepend new IP header */
151 	M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
152 	if (m && m->m_len < sizeof(struct ip6_hdr))
153 		m = m_pullup(m, sizeof(struct ip6_hdr));
154 	if (m == NULL)
155 		return ENOBUFS;
156 
157 	ip6 = mtod(m, struct ip6_hdr *);
158 	ip6->ip6_flow	= 0;
159 	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
160 	ip6->ip6_vfc	|= IPV6_VERSION;
161 #if 0	/* ip6->ip6_plen will be filled by ip6_output */
162 	ip6->ip6_plen	= htons((u_int16_t)m->m_pkthdr.len);
163 #endif
164 	ip6->ip6_nxt	= proto;
165 	ip6->ip6_hlim	= ip6_gif_hlim;
166 	ip6->ip6_src	= sin6_src->sin6_addr;
167 	/* bidirectional configured tunnel mode */
168 	if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
169 		ip6->ip6_dst = sin6_dst->sin6_addr;
170 	else  {
171 		m_freem(m);
172 		return ENETUNREACH;
173 	}
174 	if (ifp->if_flags & IFF_LINK1)
175 		ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
176 	else
177 		ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
178 	ip6->ip6_flow &= ~ntohl(0xff00000);
179 	ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
180 
181 	sc = ifp->if_softc;
182 	gro = percpu_getref(sc->gif_ro_percpu);
183 	mutex_enter(gro->gr_lock);
184 	ro = &gro->gr_ro;
185 	rt = rtcache_lookup(ro, var->gv_pdst);
186 	if (rt == NULL) {
187 		mutex_exit(gro->gr_lock);
188 		percpu_putref(sc->gif_ro_percpu);
189 		m_freem(m);
190 		return ENETUNREACH;
191 	}
192 
193 	/* If the route constitutes infinite encapsulation, punt. */
194 	if (rt->rt_ifp == ifp) {
195 		rtcache_unref(rt, ro);
196 		rtcache_free(ro);
197 		mutex_exit(gro->gr_lock);
198 		percpu_putref(sc->gif_ro_percpu);
199 		m_freem(m);
200 		return ENETUNREACH;	/* XXX */
201 	}
202 	rtcache_unref(rt, ro);
203 
204 #ifdef IPV6_MINMTU
205 	/*
206 	 * force fragmentation to minimum MTU, to avoid path MTU discovery.
207 	 * it is too painful to ask for resend of inner packet, to achieve
208 	 * path MTU discovery for encapsulated packets.
209 	 */
210 	error = ip6_output(m, 0, ro, IPV6_MINMTU, NULL, NULL, NULL);
211 #else
212 	error = ip6_output(m, 0, ro, 0, NULL, NULL, NULL);
213 #endif
214 	mutex_exit(gro->gr_lock);
215 	percpu_putref(sc->gif_ro_percpu);
216 	return (error);
217 }
218 
219 int
220 in6_gif_input(struct mbuf **mp, int *offp, int proto, void *eparg)
221 {
222 	struct mbuf *m = *mp;
223 	struct gif_softc *sc = eparg;
224 	struct ifnet *gifp;
225 	struct ip6_hdr *ip6;
226 	int af = 0;
227 	u_int32_t otos;
228 
229 	KASSERT(sc != NULL);
230 
231 	ip6 = mtod(m, struct ip6_hdr *);
232 
233 	gifp = &sc->gif_if;
234 	if ((gifp->if_flags & IFF_UP) == 0) {
235 		m_freem(m);
236 		IP6_STATINC(IP6_STAT_NOGIF);
237 		return IPPROTO_DONE;
238 	}
239 #ifndef GIF_ENCAPCHECK
240 	struct psref psref_var;
241 	struct gif_variant *var = gif_getref_variant(sc, &psref_var);
242 	/* other CPU do delete_tunnel */
243 	if (var->gv_psrc == NULL || var->gv_pdst == NULL) {
244 		gif_putref_variant(var, &psref_var);
245 		m_freem(m);
246 		IP6_STATINC(IP6_STAT_NOGIF);
247 		return IPPROTO_DONE;
248 	}
249 
250 	struct psref psref;
251 	struct ifnet *rcvif = m_get_rcvif_psref(m, &psref);
252 	if (rcvif == NULL || !gif_validate6(ip6, var, rcvif)) {
253 		m_put_rcvif_psref(rcvif, &psref);
254 		gif_putref_variant(var, &psref_var);
255 		m_freem(m);
256 		IP6_STATINC(IP6_STAT_NOGIF);
257 		return IPPROTO_DONE;
258 	}
259 	m_put_rcvif_psref(rcvif, &psref);
260 	gif_putref_variant(var, &psref_var);
261 #endif
262 
263 	otos = ip6->ip6_flow;
264 	m_adj(m, *offp);
265 
266 	switch (proto) {
267 #ifdef INET
268 	case IPPROTO_IPV4:
269 	    {
270 		struct ip *ip;
271 		u_int8_t otos8;
272 		af = AF_INET;
273 		otos8 = (ntohl(otos) >> 20) & 0xff;
274 		if (m->m_len < sizeof(*ip)) {
275 			m = m_pullup(m, sizeof(*ip));
276 			if (!m)
277 				return IPPROTO_DONE;
278 		}
279 		ip = mtod(m, struct ip *);
280 		if (gifp->if_flags & IFF_LINK1)
281 			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
282 		else
283 			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
284 		break;
285 	    }
286 #endif /* INET */
287 #ifdef INET6
288 	case IPPROTO_IPV6:
289 	    {
290 		struct ip6_hdr *ip6x;
291 		af = AF_INET6;
292 		if (m->m_len < sizeof(*ip6x)) {
293 			m = m_pullup(m, sizeof(*ip6x));
294 			if (!m)
295 				return IPPROTO_DONE;
296 		}
297 		ip6x = mtod(m, struct ip6_hdr *);
298 		if (gifp->if_flags & IFF_LINK1)
299 			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow);
300 		else
301 			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow);
302 		break;
303 	    }
304 #endif
305 	default:
306 		IP6_STATINC(IP6_STAT_NOGIF);
307 		m_freem(m);
308 		return IPPROTO_DONE;
309 	}
310 
311 	gif_input(m, af, gifp);
312 	return IPPROTO_DONE;
313 }
314 
315 /*
316  * validate outer address.
317  */
318 static int
319 gif_validate6(const struct ip6_hdr *ip6, struct gif_variant *var,
320 	struct ifnet *ifp)
321 {
322 	const struct sockaddr_in6 *src, *dst;
323 	int ret;
324 
325 	src = satosin6(var->gv_psrc);
326 	dst = satosin6(var->gv_pdst);
327 
328 	ret = in6_tunnel_validate(ip6, &src->sin6_addr, &dst->sin6_addr);
329 	if (ret == 0)
330 		return 0;
331 
332 	/* ingress filters on outer source */
333 	if ((var->gv_softc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
334 		union {
335 			struct sockaddr sa;
336 			struct sockaddr_in6 sin6;
337 		} u;
338 		struct rtentry *rt;
339 
340 		/* XXX scopeid */
341 		sockaddr_in6_init(&u.sin6, &ip6->ip6_src, 0, 0, 0);
342 		rt = rtalloc1(&u.sa, 0);
343 		if (rt == NULL || rt->rt_ifp != ifp) {
344 #if 0
345 			char ip6buf[INET6_ADDRSTRLEN];
346 			log(LOG_WARNING, "%s: packet from %s dropped "
347 			    "due to ingress filter\n",
348 			    if_name(&var->gv_softc->gif_if),
349 			    IN6_PRINT(ip6buf, &u.sin6.sin6_addr));
350 #endif
351 			if (rt != NULL)
352 				rt_unref(rt);
353 			return 0;
354 		}
355 		rt_unref(rt);
356 	}
357 
358 	return ret;
359 }
360 
361 #ifdef GIF_ENCAPCHECK
362 /*
363  * we know that we are in IFF_UP, outer address available, and outer family
364  * matched the physical addr family.  see gif_encapcheck().
365  */
366 int
367 gif_encapcheck6(struct mbuf *m, int off, int proto, struct gif_variant *var)
368 {
369 	struct ip6_hdr ip6;
370 	struct ifnet *ifp = NULL;
371 	int r;
372 	struct psref psref;
373 
374 	m_copydata(m, 0, sizeof(ip6), (void *)&ip6);
375 	if ((m->m_flags & M_PKTHDR) != 0)
376 		ifp = m_get_rcvif_psref(m, &psref);
377 
378 	r = gif_validate6(&ip6, var, ifp);
379 
380 	m_put_rcvif_psref(ifp, &psref);
381 	return r;
382 }
383 #endif
384 
385 int
386 in6_gif_attach(struct gif_variant *var)
387 {
388 #ifndef GIF_ENCAPCHECK
389 	struct sockaddr_in6 mask6;
390 
391 	memset(&mask6, 0, 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 (!var->gv_psrc || !var->gv_pdst)
397 		return EINVAL;
398 	var->gv_encap_cookie6 = encap_attach(AF_INET6, -1, var->gv_psrc,
399 	    sin6tosa(&mask6), var->gv_pdst, sin6tosa(&mask6),
400 	    (const void *)&in6_gif_encapsw, var->gv_softc);
401 #else
402 	var->gv_encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
403 	    &in6_gif_encapsw, var->gv_softc);
404 #endif
405 	if (var->gv_encap_cookie6 == NULL)
406 		return EEXIST;
407 
408 	var->gv_output = in6_gif_output;
409 	return 0;
410 }
411 
412 int
413 in6_gif_detach(struct gif_variant *var)
414 {
415 	int error;
416 	struct gif_softc *sc = var->gv_softc;
417 
418 	error = encap_detach(var->gv_encap_cookie6);
419 	if (error == 0)
420 		var->gv_encap_cookie6 = NULL;
421 
422 	percpu_foreach(sc->gif_ro_percpu, gif_rtcache_free_pc, NULL);
423 
424 	return error;
425 }
426 
427 void *
428 in6_gif_ctlinput(int cmd, const struct sockaddr *sa, void *d, void *eparg)
429 {
430 	struct gif_softc *sc = eparg;
431 	struct gif_variant *var;
432 	struct ip6ctlparam *ip6cp = NULL;
433 	struct ip6_hdr *ip6;
434 	const struct sockaddr_in6 *dst6;
435 	struct route *ro;
436 	struct psref psref;
437 
438 	if (sa->sa_family != AF_INET6 ||
439 	    sa->sa_len != sizeof(struct sockaddr_in6))
440 		return NULL;
441 
442 	if ((unsigned)cmd >= PRC_NCMDS)
443 		return NULL;
444 	if (cmd == PRC_HOSTDEAD)
445 		d = NULL;
446 	else if (inet6ctlerrmap[cmd] == 0)
447 		return NULL;
448 
449 	/* if the parameter is from icmp6, decode it. */
450 	if (d != NULL) {
451 		ip6cp = (struct ip6ctlparam *)d;
452 		ip6 = ip6cp->ip6c_ip6;
453 	} else {
454 		ip6 = NULL;
455 	}
456 
457 	if (!ip6)
458 		return NULL;
459 
460 	var = gif_getref_variant(sc, &psref);
461 	if (var->gv_psrc == NULL || var->gv_pdst == NULL) {
462 		gif_putref_variant(var, &psref);
463 		return NULL;
464 	}
465 	if (var->gv_psrc->sa_family != AF_INET6) {
466 		gif_putref_variant(var, &psref);
467 		return NULL;
468 	}
469 	gif_putref_variant(var, &psref);
470 
471 	ro = percpu_getref(sc->gif_ro_percpu);
472 	dst6 = satocsin6(rtcache_getdst(ro));
473 	/* XXX scope */
474 	if (dst6 == NULL)
475 		;
476 	else if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr))
477 		rtcache_free(ro);
478 
479 	percpu_putref(sc->gif_ro_percpu);
480 	return NULL;
481 }
482 
483 ENCAP_PR_WRAP_CTLINPUT(in6_gif_ctlinput)
484 #define	in6_gif_ctlinput	in6_gif_ctlinput_wrapper
485 
486 static const struct encapsw in6_gif_encapsw = {
487 	.encapsw6 = {
488 		.pr_input	= in6_gif_input,
489 		.pr_ctlinput	= in6_gif_ctlinput,
490 	}
491 };
492