1/*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $
30 */
31
32#include <sys/cdefs.h>
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81static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
82 struct ifnet *);
83
84extern struct domain inet6domain;
85struct ip6protosw in6_gif_protosw = {
86 .pr_type = SOCK_RAW,
87 .pr_domain = &inet6domain,
88 .pr_protocol = 0, /* IPPROTO_IPV[46] */
89 .pr_flags = PR_ATOMIC|PR_ADDR,
90 .pr_input = in6_gif_input,
91 .pr_output = rip6_output,
92 .pr_ctloutput = rip6_ctloutput,
93 .pr_usrreqs = &rip6_usrreqs
94};
95
96int
97in6_gif_output(struct ifnet *ifp,
98 int family, /* family of the packet to be encapsulate */
99 struct mbuf *m)
100{
101 struct gif_softc *sc = ifp->if_softc;
102 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
103 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
104 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
105 struct ip6_hdr *ip6;
106 struct etherip_header eiphdr;
107 int error, len, proto;
108 u_int8_t itos, otos;
109
110 GIF_LOCK_ASSERT(sc);
111
112 if (sin6_src == NULL || sin6_dst == NULL ||
113 sin6_src->sin6_family != AF_INET6 ||
114 sin6_dst->sin6_family != AF_INET6) {
115 m_freem(m);
116 return EAFNOSUPPORT;
117 }
118
119 switch (family) {
120#ifdef INET
121 case AF_INET:
122 {
123 struct ip *ip;
124
125 proto = IPPROTO_IPV4;
126 if (m->m_len < sizeof(*ip)) {
127 m = m_pullup(m, sizeof(*ip));
128 if (!m)
129 return ENOBUFS;
130 }
131 ip = mtod(m, struct ip *);
132 itos = ip->ip_tos;
133 break;
134 }
135#endif
136#ifdef INET6
137 case AF_INET6:
138 {
139 struct ip6_hdr *ip6;
140 proto = IPPROTO_IPV6;
141 if (m->m_len < sizeof(*ip6)) {
142 m = m_pullup(m, sizeof(*ip6));
143 if (!m)
144 return ENOBUFS;
145 }
146 ip6 = mtod(m, struct ip6_hdr *);
147 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
148 break;
149 }
150#endif
151 case AF_LINK:
152 proto = IPPROTO_ETHERIP;
153
154 /*
155 * GIF_SEND_REVETHIP (disabled by default) intentionally
156 * sends an EtherIP packet with revered version field in
157 * the header. This is a knob for backward compatibility
158 * with FreeBSD 7.2R or prior.
159 */
160 if ((sc->gif_options & GIF_SEND_REVETHIP)) {
161 eiphdr.eip_ver = 0;
162 eiphdr.eip_resvl = ETHERIP_VERSION;
163 eiphdr.eip_resvh = 0;
164 } else {
165 eiphdr.eip_ver = ETHERIP_VERSION;
166 eiphdr.eip_resvl = 0;
167 eiphdr.eip_resvh = 0;
168 }
169 /* prepend Ethernet-in-IP header */
170 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
171 if (m && m->m_len < sizeof(struct etherip_header))
172 m = m_pullup(m, sizeof(struct etherip_header));
173 if (m == NULL)
174 return ENOBUFS;
175 bcopy(&eiphdr, mtod(m, struct etherip_header *),
176 sizeof(struct etherip_header));
177 break;
178
179 default:
180#ifdef DEBUG
181 printf("in6_gif_output: warning: unknown family %d passed\n",
182 family);
183#endif
184 m_freem(m);
185 return EAFNOSUPPORT;
186 }
187
188 /* prepend new IP header */
189 len = sizeof(struct ip6_hdr);
190#ifndef __NO_STRICT_ALIGNMENT
191 if (family == AF_LINK)
192 len += ETHERIP_ALIGN;
193#endif
194 M_PREPEND(m, len, M_DONTWAIT);
195 if (m != NULL && m->m_len < len)
196 m = m_pullup(m, len);
197 if (m == NULL) {
198 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
199 return ENOBUFS;
200 }
201#ifndef __NO_STRICT_ALIGNMENT
202 if (family == AF_LINK) {
203 len = mtod(m, vm_offset_t) & 3;
204 KASSERT(len == 0 || len == ETHERIP_ALIGN,
205 ("in6_gif_output: unexpected misalignment"));
206 m->m_data += len;
207 m->m_len -= ETHERIP_ALIGN;
208 }
209#endif
210
211 ip6 = mtod(m, struct ip6_hdr *);
212 ip6->ip6_flow = 0;
213 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
214 ip6->ip6_vfc |= IPV6_VERSION;
215 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
216 ip6->ip6_nxt = proto;
217 ip6->ip6_hlim = V_ip6_gif_hlim;
218 ip6->ip6_src = sin6_src->sin6_addr;
219 /* bidirectional configured tunnel mode */
220 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
221 ip6->ip6_dst = sin6_dst->sin6_addr;
222 else {
223 m_freem(m);
224 return ENETUNREACH;
225 }
226 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
227 &otos, &itos);
228 ip6->ip6_flow &= ~htonl(0xff << 20);
229 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
230
231 if (dst->sin6_family != sin6_dst->sin6_family ||
232 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
233 /* cache route doesn't match */
234 bzero(dst, sizeof(*dst));
235 dst->sin6_family = sin6_dst->sin6_family;
236 dst->sin6_len = sizeof(struct sockaddr_in6);
237 dst->sin6_addr = sin6_dst->sin6_addr;
238 if (sc->gif_ro6.ro_rt) {
239 RTFREE(sc->gif_ro6.ro_rt);
240 sc->gif_ro6.ro_rt = NULL;
241 }
242#if 0
243 GIF2IFP(sc)->if_mtu = GIF_MTU;
244#endif
245 }
246
247 if (sc->gif_ro6.ro_rt == NULL) {
248 rtalloc((struct route *)&sc->gif_ro6);
249 if (sc->gif_ro6.ro_rt == NULL) {
250 m_freem(m);
251 return ENETUNREACH;
252 }
253
254 /* if it constitutes infinite encapsulation, punt. */
255 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
256 m_freem(m);
257 return ENETUNREACH; /*XXX*/
258 }
259#if 0
260 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
261 - sizeof(struct ip6_hdr);
262#endif
263 }
264
265#ifdef IPV6_MINMTU
266 /*
267 * force fragmentation to minimum MTU, to avoid path MTU discovery.
268 * it is too painful to ask for resend of inner packet, to achieve
269 * path MTU discovery for encapsulated packets.
270 */
271 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
272#else
273 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
274#endif
275
276 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
277 sc->gif_ro6.ro_rt != NULL) {
278 RTFREE(sc->gif_ro6.ro_rt);
279 sc->gif_ro6.ro_rt = NULL;
280 }
281
282 return (error);
283}
284
285int
286in6_gif_input(struct mbuf **mp, int *offp, int proto)
287{
288 struct mbuf *m = *mp;
289 struct ifnet *gifp = NULL;
290 struct gif_softc *sc;
291 struct ip6_hdr *ip6;
292 int af = 0;
293 u_int32_t otos;
294
295 ip6 = mtod(m, struct ip6_hdr *);
296
297 sc = (struct gif_softc *)encap_getarg(m);
298 if (sc == NULL) {
299 m_freem(m);
300 V_ip6stat.ip6s_nogif++;
301 return IPPROTO_DONE;
302 }
303
304 gifp = GIF2IFP(sc);
305 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
306 m_freem(m);
307 V_ip6stat.ip6s_nogif++;
308 return IPPROTO_DONE;
309 }
310
311 otos = ip6->ip6_flow;
312 m_adj(m, *offp);
313
314 switch (proto) {
315#ifdef INET
316 case IPPROTO_IPV4:
317 {
318 struct ip *ip;
319 u_int8_t otos8;
320 af = AF_INET;
321 otos8 = (ntohl(otos) >> 20) & 0xff;
322 if (m->m_len < sizeof(*ip)) {
323 m = m_pullup(m, sizeof(*ip));
324 if (!m)
325 return IPPROTO_DONE;
326 }
327 ip = mtod(m, struct ip *);
328 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
329 ECN_ALLOWED : ECN_NOCARE,
330 &otos8, &ip->ip_tos) == 0) {
331 m_freem(m);
332 return IPPROTO_DONE;
333 }
334 break;
335 }
336#endif /* INET */
337#ifdef INET6
338 case IPPROTO_IPV6:
339 {
340 struct ip6_hdr *ip6;
341 af = AF_INET6;
342 if (m->m_len < sizeof(*ip6)) {
343 m = m_pullup(m, sizeof(*ip6));
344 if (!m)
345 return IPPROTO_DONE;
346 }
347 ip6 = mtod(m, struct ip6_hdr *);
348 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
349 ECN_ALLOWED : ECN_NOCARE,
350 &otos, &ip6->ip6_flow) == 0) {
351 m_freem(m);
352 return IPPROTO_DONE;
353 }
354 break;
355 }
356#endif
357 case IPPROTO_ETHERIP:
358 af = AF_LINK;
359 break;
360
361 default:
362 V_ip6stat.ip6s_nogif++;
363 m_freem(m);
364 return IPPROTO_DONE;
365 }
366
367 gif_input(m, af, gifp);
368 return IPPROTO_DONE;
369}
370
371/*
372 * validate outer address.
373 */
374static int
375gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
376 struct ifnet *ifp)
377{
378 struct sockaddr_in6 *src, *dst;
379
380 src = (struct sockaddr_in6 *)sc->gif_psrc;
381 dst = (struct sockaddr_in6 *)sc->gif_pdst;
382
383 /*
384 * Check for address match. Note that the check is for an incoming
385 * packet. We should compare the *source* address in our configuration
386 * and the *destination* address of the packet, and vice versa.
387 */
388 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
389 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
390 return 0;
391
392 /* martian filters on outer source - done in ip6_input */
393
394 /* ingress filters on outer source */
395 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
396 struct sockaddr_in6 sin6;
397 struct rtentry *rt;
398
399 bzero(&sin6, sizeof(sin6));
400 sin6.sin6_family = AF_INET6;
401 sin6.sin6_len = sizeof(struct sockaddr_in6);
402 sin6.sin6_addr = ip6->ip6_src;
403 sin6.sin6_scope_id = 0; /* XXX */
404
405 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
406 if (!rt || rt->rt_ifp != ifp) {
407#if 0
408 char ip6buf[INET6_ADDRSTRLEN];
409 log(LOG_WARNING, "%s: packet from %s dropped "
410 "due to ingress filter\n", if_name(GIF2IFP(sc)),
411 ip6_sprintf(ip6buf, &sin6.sin6_addr));
412#endif
413 if (rt)
414 RTFREE_LOCKED(rt);
415 return 0;
416 }
417 RTFREE_LOCKED(rt);
418 }
419
420 return 128 * 2;
421}
422
423/*
424 * we know that we are in IFF_UP, outer address available, and outer family
425 * matched the physical addr family. see gif_encapcheck().
426 * sanity check for arg should have been done in the caller.
427 */
428int
429gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
430{
431 struct ip6_hdr ip6;
432 struct gif_softc *sc;
433 struct ifnet *ifp;
434
435 /* sanity check done in caller */
436 sc = (struct gif_softc *)arg;
437
438 /* LINTED const cast */
439 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
440 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
441
442 return gif_validate6(&ip6, sc, ifp);
443}
444
445int
446in6_gif_attach(struct gif_softc *sc)
447{
448 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
449 (void *)&in6_gif_protosw, sc);
450 if (sc->encap_cookie6 == NULL)
451 return EEXIST;
452 return 0;
453}
454
455int
456in6_gif_detach(struct gif_softc *sc)
457{
458 int error;
459
460 error = encap_detach(sc->encap_cookie6);
461 if (error == 0)
462 sc->encap_cookie6 = NULL;
463 return error;
464}
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