xref: /dragonfly/sys/netinet6/in6_gif.c (revision aa8d5dcb) 
1 /*	$FreeBSD: src/sys/netinet6/in6_gif.c,v 1.2.2.7 2003/01/23 21:06:47 sam Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/in6_gif.c,v 1.5 2004/03/06 01:58:56 hsu Exp $	*/
3 /*	$KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/socket.h>
40 #include <sys/sockio.h>
41 #include <sys/mbuf.h>
42 #include <sys/errno.h>
43 #include <sys/queue.h>
44 #include <sys/syslog.h>
45 #include <sys/protosw.h>
46 
47 #include <sys/malloc.h>
48 
49 #include <net/if.h>
50 #include <net/route.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #ifdef INET
55 #include <netinet/ip.h>
56 #endif
57 #include <netinet/ip_encap.h>
58 #ifdef INET6
59 #include <netinet/ip6.h>
60 #include <netinet6/ip6_var.h>
61 #include <netinet6/in6_gif.h>
62 #include <netinet6/in6_var.h>
63 #endif
64 #include <netinet6/ip6protosw.h>
65 #include <netinet/ip_ecn.h>
66 #ifdef INET6
67 #include <netinet6/ip6_ecn.h>
68 #endif
69 
70 #include <net/gif/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 extern  struct domain6 inet6domain;
78 struct ip6protosw in6_gif_protosw =
79 { SOCK_RAW,	&inet6domain,	0/*IPPROTO_IPV[46]*/,	PR_ATOMIC|PR_ADDR,
80   in6_gif_input, rip6_output,	0,		rip6_ctloutput,
81   cpu0_soport,
82   0,		0,		0,		0,
83   &rip6_usrreqs
84 };
85 
86 int
87 in6_gif_output(ifp, family, m)
88 	struct ifnet *ifp;
89 	int family; /* family of the packet to be encapsulate. */
90 	struct mbuf *m;
91 {
92 	struct gif_softc *sc = (struct gif_softc*)ifp;
93 	struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
94 	struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
95 	struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
96 	struct ip6_hdr *ip6;
97 	int proto;
98 	u_int8_t itos, otos;
99 
100 	if (sin6_src == NULL || sin6_dst == NULL ||
101 	    sin6_src->sin6_family != AF_INET6 ||
102 	    sin6_dst->sin6_family != AF_INET6) {
103 		m_freem(m);
104 		return EAFNOSUPPORT;
105 	}
106 
107 	switch (family) {
108 #ifdef INET
109 	case AF_INET:
110 	    {
111 		struct ip *ip;
112 
113 		proto = IPPROTO_IPV4;
114 		if (m->m_len < sizeof(*ip)) {
115 			m = m_pullup(m, sizeof(*ip));
116 			if (!m)
117 				return ENOBUFS;
118 		}
119 		ip = mtod(m, struct ip *);
120 		itos = ip->ip_tos;
121 		break;
122 	    }
123 #endif
124 #ifdef INET6
125 	case AF_INET6:
126 	    {
127 		struct ip6_hdr *ip6;
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 		printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
154 		return ENOBUFS;
155 	}
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 	ip6->ip6_plen	= htons((u_short)m->m_pkthdr.len);
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 	if (dst->sin6_family != sin6_dst->sin6_family ||
180 	     !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
181 		/* cache route doesn't match */
182 		bzero(dst, sizeof(*dst));
183 		dst->sin6_family = sin6_dst->sin6_family;
184 		dst->sin6_len = sizeof(struct sockaddr_in6);
185 		dst->sin6_addr = sin6_dst->sin6_addr;
186 		if (sc->gif_ro6.ro_rt) {
187 			RTFREE(sc->gif_ro6.ro_rt);
188 			sc->gif_ro6.ro_rt = NULL;
189 		}
190 #if 0
191 		sc->gif_if.if_mtu = GIF_MTU;
192 #endif
193 	}
194 
195 	if (sc->gif_ro6.ro_rt == NULL) {
196 		rtalloc((struct route *)&sc->gif_ro6);
197 		if (sc->gif_ro6.ro_rt == NULL) {
198 			m_freem(m);
199 			return ENETUNREACH;
200 		}
201 
202 		/* if it constitutes infinite encapsulation, punt. */
203 		if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
204 			m_freem(m);
205 			return ENETUNREACH;	/*XXX*/
206 		}
207 #if 0
208 		ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
209 			- sizeof(struct ip6_hdr);
210 #endif
211 	}
212 
213 #ifdef IPV6_MINMTU
214 	/*
215 	 * force fragmentation to minimum MTU, to avoid path MTU discovery.
216 	 * it is too painful to ask for resend of inner packet, to achieve
217 	 * path MTU discovery for encapsulated packets.
218 	 */
219 	return(ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL));
220 #else
221 	return(ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL));
222 #endif
223 }
224 
225 int in6_gif_input(mp, offp, proto)
226 	struct mbuf **mp;
227 	int *offp, proto;
228 {
229 	struct mbuf *m = *mp;
230 	struct ifnet *gifp = NULL;
231 	struct ip6_hdr *ip6;
232 	int af = 0;
233 	u_int32_t otos;
234 
235 	ip6 = mtod(m, struct ip6_hdr *);
236 
237 	gifp = (struct ifnet *)encap_getarg(m);
238 
239 	if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
240 		m_freem(m);
241 		ip6stat.ip6s_nogif++;
242 		return IPPROTO_DONE;
243 	}
244 
245 	otos = ip6->ip6_flow;
246 	m_adj(m, *offp);
247 
248 	switch (proto) {
249 #ifdef INET
250 	case IPPROTO_IPV4:
251 	    {
252 		struct ip *ip;
253 		u_int8_t otos8;
254 		af = AF_INET;
255 		otos8 = (ntohl(otos) >> 20) & 0xff;
256 		if (m->m_len < sizeof(*ip)) {
257 			m = m_pullup(m, sizeof(*ip));
258 			if (!m)
259 				return IPPROTO_DONE;
260 		}
261 		ip = mtod(m, struct ip *);
262 		if (gifp->if_flags & IFF_LINK1)
263 			ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
264 		else
265 			ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
266 		break;
267 	    }
268 #endif /* INET */
269 #ifdef INET6
270 	case IPPROTO_IPV6:
271 	    {
272 		struct ip6_hdr *ip6;
273 		af = AF_INET6;
274 		if (m->m_len < sizeof(*ip6)) {
275 			m = m_pullup(m, sizeof(*ip6));
276 			if (!m)
277 				return IPPROTO_DONE;
278 		}
279 		ip6 = mtod(m, struct ip6_hdr *);
280 		if (gifp->if_flags & IFF_LINK1)
281 			ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
282 		else
283 			ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
284 		break;
285 	    }
286 #endif
287 	default:
288 		ip6stat.ip6s_nogif++;
289 		m_freem(m);
290 		return IPPROTO_DONE;
291 	}
292 
293 	gif_input(m, af, gifp);
294 	return IPPROTO_DONE;
295 }
296 
297 /*
298  * validate outer address.
299  */
300 static int
301 gif_validate6(ip6, sc, ifp)
302 	const struct ip6_hdr *ip6;
303 	struct gif_softc *sc;
304 	struct ifnet *ifp;
305 {
306 	struct sockaddr_in6 *src, *dst;
307 
308 	src = (struct sockaddr_in6 *)sc->gif_psrc;
309 	dst = (struct sockaddr_in6 *)sc->gif_pdst;
310 
311 	/*
312 	 * Check for address match.  Note that the check is for an incoming
313 	 * packet.  We should compare the *source* address in our configuration
314 	 * and the *destination* address of the packet, and vice versa.
315 	 */
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 		struct sockaddr_in6 sin6;
325 		struct rtentry *rt;
326 
327 		bzero(&sin6, sizeof(sin6));
328 		sin6.sin6_family = AF_INET6;
329 		sin6.sin6_len = sizeof(struct sockaddr_in6);
330 		sin6.sin6_addr = ip6->ip6_src;
331 #ifndef SCOPEDROUTING
332 		sin6.sin6_scope_id = 0; /* XXX */
333 #endif
334 
335 		rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
336 		if (!rt || rt->rt_ifp != ifp) {
337 #if 0
338 			log(LOG_WARNING, "%s: packet from %s dropped "
339 			    "due to ingress filter\n", if_name(&sc->gif_if),
340 			    ip6_sprintf(&sin6.sin6_addr));
341 #endif
342 			if (rt)
343 				rtfree(rt);
344 			return 0;
345 		}
346 		rtfree(rt);
347 	}
348 
349 	return 128 * 2;
350 }
351 
352 /*
353  * we know that we are in IFF_UP, outer address available, and outer family
354  * matched the physical addr family.  see gif_encapcheck().
355  * sanity check for arg should have been done in the caller.
356  */
357 int
358 gif_encapcheck6(m, off, proto, arg)
359 	const struct mbuf *m;
360 	int off;
361 	int proto;
362 	void *arg;
363 {
364 	struct ip6_hdr ip6;
365 	struct gif_softc *sc;
366 	struct ifnet *ifp;
367 
368 	/* sanity check done in caller */
369 	sc = (struct gif_softc *)arg;
370 
371 	m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
372 	ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
373 
374 	return gif_validate6(&ip6, sc, ifp);
375 }
376 
377 int
378 in6_gif_attach(sc)
379 	struct gif_softc *sc;
380 {
381 	sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
382 	    (struct protosw *)&in6_gif_protosw, sc);
383 	if (sc->encap_cookie6 == NULL)
384 		return EEXIST;
385 	return 0;
386 }
387 
388 int
389 in6_gif_detach(sc)
390 	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 	return error;
398 }
399