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>
33 __FBSDID("$FreeBSD: releng/7.4/sys/netinet6/in6_gif.c 196918 2009-09-07 10:15:50Z ume $");
34
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/socket.h>
41 #include <sys/sockio.h>
42 #include <sys/mbuf.h>
43 #include <sys/errno.h>
44 #include <sys/queue.h>
45 #include <sys/syslog.h>
46 #include <sys/protosw.h>
47
48 #include <sys/malloc.h>
49
50 #include <net/if.h>
51 #include <net/route.h>
52
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #ifdef INET
56 #include <netinet/ip.h>
57 #endif
58 #include <netinet/ip_encap.h>
59 #ifdef INET6
60 #include <netinet/ip6.h>
61 #include <netinet6/ip6_var.h>
62 #include <netinet6/in6_gif.h>
63 #include <netinet6/in6_var.h>
64 #endif
65 #include <netinet6/ip6protosw.h>
66 #include <netinet/ip_ecn.h>
67 #ifdef INET6
68 #include <netinet6/ip6_ecn.h>
69 #endif
70
71 #include <net/if_gif.h>
72
73 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
74 struct ifnet *);
75
76 extern struct domain inet6domain;
77 struct ip6protosw in6_gif_protosw = {
78 .pr_type = SOCK_RAW,
79 .pr_domain = &inet6domain,
80 .pr_protocol = 0, /* IPPROTO_IPV[46] */
81 .pr_flags = PR_ATOMIC|PR_ADDR,
82 .pr_input = in6_gif_input,
83 .pr_output = rip6_output,
84 .pr_ctloutput = rip6_ctloutput,
85 .pr_usrreqs = &rip6_usrreqs
86 };
87
88 int
89 in6_gif_output(struct ifnet *ifp,
90 int family, /* family of the packet to be encapsulate */
91 struct mbuf *m)
92 {
93 struct gif_softc *sc = ifp->if_softc;
94 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
95 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
96 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
97 struct ip6_hdr *ip6;
98 struct etherip_header eiphdr;
99 int error, len, proto;
100 u_int8_t itos, otos;
101
102 GIF_LOCK_ASSERT(sc);
103
104 if (sin6_src == NULL || sin6_dst == NULL ||
105 sin6_src->sin6_family != AF_INET6 ||
106 sin6_dst->sin6_family != AF_INET6) {
107 m_freem(m);
108 return EAFNOSUPPORT;
109 }
110
111 switch (family) {
112 #ifdef INET
113 case AF_INET:
114 {
115 struct ip *ip;
116
117 proto = IPPROTO_IPV4;
118 if (m->m_len < sizeof(*ip)) {
119 m = m_pullup(m, sizeof(*ip));
120 if (!m)
121 return ENOBUFS;
122 }
123 ip = mtod(m, struct ip *);
124 itos = ip->ip_tos;
125 break;
126 }
127 #endif
128 #ifdef INET6
129 case AF_INET6:
130 {
131 struct ip6_hdr *ip6;
132 proto = IPPROTO_IPV6;
133 if (m->m_len < sizeof(*ip6)) {
134 m = m_pullup(m, sizeof(*ip6));
135 if (!m)
136 return ENOBUFS;
137 }
138 ip6 = mtod(m, struct ip6_hdr *);
139 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
140 break;
141 }
142 #endif
143 case AF_LINK:
144 proto = IPPROTO_ETHERIP;
145
146 /*
147 * GIF_SEND_REVETHIP (disabled by default) intentionally
148 * sends an EtherIP packet with revered version field in
149 * the header. This is a knob for backward compatibility
150 * with FreeBSD 7.2R or prior.
151 */
152 if ((sc->gif_options & GIF_SEND_REVETHIP)) {
153 eiphdr.eip_ver = 0;
154 eiphdr.eip_resvl = ETHERIP_VERSION;
155 eiphdr.eip_resvh = 0;
156 } else {
157 eiphdr.eip_ver = ETHERIP_VERSION;
158 eiphdr.eip_resvl = 0;
159 eiphdr.eip_resvh = 0;
160 }
161 /* prepend Ethernet-in-IP header */
162 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
163 if (m && m->m_len < sizeof(struct etherip_header))
164 m = m_pullup(m, sizeof(struct etherip_header));
165 if (m == NULL)
166 return ENOBUFS;
167 bcopy(&eiphdr, mtod(m, struct etherip_header *),
168 sizeof(struct etherip_header));
169 break;
170
171 default:
172 #ifdef DEBUG
173 printf("in6_gif_output: warning: unknown family %d passed\n",
174 family);
175 #endif
176 m_freem(m);
177 return EAFNOSUPPORT;
178 }
179
180 /* prepend new IP header */
181 len = sizeof(struct ip6_hdr);
182 #ifndef __NO_STRICT_ALIGNMENT
183 if (family == AF_LINK)
184 len += ETHERIP_ALIGN;
185 #endif
186 M_PREPEND(m, len, M_DONTWAIT);
187 if (m != NULL && m->m_len < len)
188 m = m_pullup(m, len);
189 if (m == NULL) {
190 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
191 return ENOBUFS;
192 }
193 #ifndef __NO_STRICT_ALIGNMENT
194 if (family == AF_LINK) {
195 len = mtod(m, vm_offset_t) & 3;
196 KASSERT(len == 0 || len == ETHERIP_ALIGN,
197 ("in6_gif_output: unexpected misalignment"));
198 m->m_data += len;
199 m->m_len -= ETHERIP_ALIGN;
200 }
201 #endif
202
203 ip6 = mtod(m, struct ip6_hdr *);
204 ip6->ip6_flow = 0;
205 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
206 ip6->ip6_vfc |= IPV6_VERSION;
207 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
208 ip6->ip6_nxt = proto;
209 ip6->ip6_hlim = ip6_gif_hlim;
210 ip6->ip6_src = sin6_src->sin6_addr;
211 /* bidirectional configured tunnel mode */
212 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
213 ip6->ip6_dst = sin6_dst->sin6_addr;
214 else {
215 m_freem(m);
216 return ENETUNREACH;
217 }
218 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
219 &otos, &itos);
220 ip6->ip6_flow &= ~htonl(0xff << 20);
221 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
222
223 if (dst->sin6_family != sin6_dst->sin6_family ||
224 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
225 /* cache route doesn't match */
226 bzero(dst, sizeof(*dst));
227 dst->sin6_family = sin6_dst->sin6_family;
228 dst->sin6_len = sizeof(struct sockaddr_in6);
229 dst->sin6_addr = sin6_dst->sin6_addr;
230 if (sc->gif_ro6.ro_rt) {
231 RTFREE(sc->gif_ro6.ro_rt);
232 sc->gif_ro6.ro_rt = NULL;
233 }
234 #if 0
235 GIF2IFP(sc)->if_mtu = GIF_MTU;
236 #endif
237 }
238
239 if (sc->gif_ro6.ro_rt == NULL) {
240 rtalloc((struct route *)&sc->gif_ro6);
241 if (sc->gif_ro6.ro_rt == NULL) {
242 m_freem(m);
243 return ENETUNREACH;
244 }
245
246 /* if it constitutes infinite encapsulation, punt. */
247 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
248 m_freem(m);
249 return ENETUNREACH; /*XXX*/
250 }
251 #if 0
252 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
253 - sizeof(struct ip6_hdr);
254 #endif
255 }
256
257 #ifdef IPV6_MINMTU
258 /*
259 * force fragmentation to minimum MTU, to avoid path MTU discovery.
260 * it is too painful to ask for resend of inner packet, to achieve
261 * path MTU discovery for encapsulated packets.
262 */
263 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
264 #else
265 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
266 #endif
267
268 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
269 sc->gif_ro6.ro_rt != NULL) {
270 RTFREE(sc->gif_ro6.ro_rt);
271 sc->gif_ro6.ro_rt = NULL;
272 }
273
274 return (error);
275 }
276
277 int
278 in6_gif_input(struct mbuf **mp, int *offp, int proto)
279 {
280 struct mbuf *m = *mp;
281 struct ifnet *gifp = NULL;
282 struct gif_softc *sc;
283 struct ip6_hdr *ip6;
284 int af = 0;
285 u_int32_t otos;
286
287 ip6 = mtod(m, struct ip6_hdr *);
288
289 sc = (struct gif_softc *)encap_getarg(m);
290 if (sc == NULL) {
291 m_freem(m);
292 ip6stat.ip6s_nogif++;
293 return IPPROTO_DONE;
294 }
295
296 gifp = GIF2IFP(sc);
297 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
298 m_freem(m);
299 ip6stat.ip6s_nogif++;
300 return IPPROTO_DONE;
301 }
302
303 otos = ip6->ip6_flow;
304 m_adj(m, *offp);
305
306 switch (proto) {
307 #ifdef INET
308 case IPPROTO_IPV4:
309 {
310 struct ip *ip;
311 u_int8_t otos8;
312 af = AF_INET;
313 otos8 = (ntohl(otos) >> 20) & 0xff;
314 if (m->m_len < sizeof(*ip)) {
315 m = m_pullup(m, sizeof(*ip));
316 if (!m)
317 return IPPROTO_DONE;
318 }
319 ip = mtod(m, struct ip *);
320 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
321 ECN_ALLOWED : ECN_NOCARE,
322 &otos8, &ip->ip_tos) == 0) {
323 m_freem(m);
324 return IPPROTO_DONE;
325 }
326 break;
327 }
328 #endif /* INET */
329 #ifdef INET6
330 case IPPROTO_IPV6:
331 {
332 struct ip6_hdr *ip6;
333 af = AF_INET6;
334 if (m->m_len < sizeof(*ip6)) {
335 m = m_pullup(m, sizeof(*ip6));
336 if (!m)
337 return IPPROTO_DONE;
338 }
339 ip6 = mtod(m, struct ip6_hdr *);
340 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
341 ECN_ALLOWED : ECN_NOCARE,
342 &otos, &ip6->ip6_flow) == 0) {
343 m_freem(m);
344 return IPPROTO_DONE;
345 }
346 break;
347 }
348 #endif
349 case IPPROTO_ETHERIP:
350 af = AF_LINK;
351 break;
352
353 default:
354 ip6stat.ip6s_nogif++;
355 m_freem(m);
356 return IPPROTO_DONE;
357 }
358
359 gif_input(m, af, gifp);
360 return IPPROTO_DONE;
361 }
362
363 /*
364 * validate outer address.
365 */
366 static int
367 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
368 struct ifnet *ifp)
369 {
370 struct sockaddr_in6 *src, *dst;
371
372 src = (struct sockaddr_in6 *)sc->gif_psrc;
373 dst = (struct sockaddr_in6 *)sc->gif_pdst;
374
375 /*
376 * Check for address match. Note that the check is for an incoming
377 * packet. We should compare the *source* address in our configuration
378 * and the *destination* address of the packet, and vice versa.
379 */
380 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
381 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
382 return 0;
383
384 /* martian filters on outer source - done in ip6_input */
385
386 /* ingress filters on outer source */
387 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
388 struct sockaddr_in6 sin6;
389 struct rtentry *rt;
390
391 bzero(&sin6, sizeof(sin6));
392 sin6.sin6_family = AF_INET6;
393 sin6.sin6_len = sizeof(struct sockaddr_in6);
394 sin6.sin6_addr = ip6->ip6_src;
395 sin6.sin6_scope_id = 0; /* XXX */
396
397 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
398 if (!rt || rt->rt_ifp != ifp) {
399 #if 0
400 char ip6buf[INET6_ADDRSTRLEN];
401 log(LOG_WARNING, "%s: packet from %s dropped "
402 "due to ingress filter\n", if_name(GIF2IFP(sc)),
403 ip6_sprintf(ip6buf, &sin6.sin6_addr));
404 #endif
405 if (rt)
406 RTFREE_LOCKED(rt);
407 return 0;
408 }
409 RTFREE_LOCKED(rt);
410 }
411
412 return 128 * 2;
413 }
414
415 /*
416 * we know that we are in IFF_UP, outer address available, and outer family
417 * matched the physical addr family. see gif_encapcheck().
418 * sanity check for arg should have been done in the caller.
419 */
420 int
421 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
422 {
423 struct ip6_hdr ip6;
424 struct gif_softc *sc;
425 struct ifnet *ifp;
426
427 /* sanity check done in caller */
428 sc = (struct gif_softc *)arg;
429
430 /* LINTED const cast */
431 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
432 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
433
434 return gif_validate6(&ip6, sc, ifp);
435 }
436
437 int
438 in6_gif_attach(struct gif_softc *sc)
439 {
440 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
441 (void *)&in6_gif_protosw, sc);
442 if (sc->encap_cookie6 == NULL)
443 return EEXIST;
444 return 0;
445 }
446
447 int
448 in6_gif_detach(struct gif_softc *sc)
449 {
450 int error;
451
452 error = encap_detach(sc->encap_cookie6);
453 if (error == 0)
454 sc->encap_cookie6 = NULL;
455 return error;
456 }
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