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/6.4/sys/netinet6/in6_gif.c 182649 2008-09-01 22:57:56Z obrien $");
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 #include <net/net_osdep.h>
74
75 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
76 struct ifnet *);
77
78 extern struct domain inet6domain;
79 struct ip6protosw in6_gif_protosw =
80 { SOCK_RAW, &inet6domain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR,
81 in6_gif_input, rip6_output, 0, rip6_ctloutput,
82 0,
83 0, 0, 0, 0,
84 &rip6_usrreqs
85 };
86
87 int
88 in6_gif_output(ifp, family, m)
89 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 proto, error;
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 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
146 eiphdr.eip_pad = 0;
147 /* prepend Ethernet-in-IP header */
148 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
149 if (m && m->m_len < sizeof(struct etherip_header))
150 m = m_pullup(m, sizeof(struct etherip_header));
151 if (m == NULL)
152 return ENOBUFS;
153 bcopy(&eiphdr, mtod(m, struct etherip_header *),
154 sizeof(struct etherip_header));
155 break;
156
157 default:
158 #ifdef DEBUG
159 printf("in6_gif_output: warning: unknown family %d passed\n",
160 family);
161 #endif
162 m_freem(m);
163 return EAFNOSUPPORT;
164 }
165
166 /* prepend new IP header */
167 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
168 if (m && m->m_len < sizeof(struct ip6_hdr))
169 m = m_pullup(m, sizeof(struct ip6_hdr));
170 if (m == NULL) {
171 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
172 return ENOBUFS;
173 }
174
175 ip6 = mtod(m, struct ip6_hdr *);
176 ip6->ip6_flow = 0;
177 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
178 ip6->ip6_vfc |= IPV6_VERSION;
179 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
180 ip6->ip6_nxt = proto;
181 ip6->ip6_hlim = ip6_gif_hlim;
182 ip6->ip6_src = sin6_src->sin6_addr;
183 /* bidirectional configured tunnel mode */
184 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
185 ip6->ip6_dst = sin6_dst->sin6_addr;
186 else {
187 m_freem(m);
188 return ENETUNREACH;
189 }
190 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
191 &otos, &itos);
192 ip6->ip6_flow &= ~htonl(0xff << 20);
193 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
194
195 if (dst->sin6_family != sin6_dst->sin6_family ||
196 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
197 /* cache route doesn't match */
198 bzero(dst, sizeof(*dst));
199 dst->sin6_family = sin6_dst->sin6_family;
200 dst->sin6_len = sizeof(struct sockaddr_in6);
201 dst->sin6_addr = sin6_dst->sin6_addr;
202 if (sc->gif_ro6.ro_rt) {
203 RTFREE(sc->gif_ro6.ro_rt);
204 sc->gif_ro6.ro_rt = NULL;
205 }
206 #if 0
207 GIF2IFP(sc)->if_mtu = GIF_MTU;
208 #endif
209 }
210
211 if (sc->gif_ro6.ro_rt == NULL) {
212 rtalloc((struct route *)&sc->gif_ro6);
213 if (sc->gif_ro6.ro_rt == NULL) {
214 m_freem(m);
215 return ENETUNREACH;
216 }
217
218 /* if it constitutes infinite encapsulation, punt. */
219 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
220 m_freem(m);
221 return ENETUNREACH; /*XXX*/
222 }
223 #if 0
224 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
225 - sizeof(struct ip6_hdr);
226 #endif
227 }
228
229 #ifdef IPV6_MINMTU
230 /*
231 * force fragmentation to minimum MTU, to avoid path MTU discovery.
232 * it is too painful to ask for resend of inner packet, to achieve
233 * path MTU discovery for encapsulated packets.
234 */
235 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
236 #else
237 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
238 #endif
239
240 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
241 sc->gif_ro6.ro_rt != NULL) {
242 RTFREE(sc->gif_ro6.ro_rt);
243 sc->gif_ro6.ro_rt = NULL;
244 }
245
246 return (error);
247 }
248
249 int
250 in6_gif_input(mp, offp, proto)
251 struct mbuf **mp;
252 int *offp, proto;
253 {
254 struct mbuf *m = *mp;
255 struct ifnet *gifp = NULL;
256 struct gif_softc *sc;
257 struct ip6_hdr *ip6;
258 int af = 0;
259 u_int32_t otos;
260
261 ip6 = mtod(m, struct ip6_hdr *);
262
263 sc = (struct gif_softc *)encap_getarg(m);
264 if (sc == NULL) {
265 m_freem(m);
266 ip6stat.ip6s_nogif++;
267 return IPPROTO_DONE;
268 }
269
270 gifp = GIF2IFP(sc);
271 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
272 m_freem(m);
273 ip6stat.ip6s_nogif++;
274 return IPPROTO_DONE;
275 }
276
277 otos = ip6->ip6_flow;
278 m_adj(m, *offp);
279
280 switch (proto) {
281 #ifdef INET
282 case IPPROTO_IPV4:
283 {
284 struct ip *ip;
285 u_int8_t otos8;
286 af = AF_INET;
287 otos8 = (ntohl(otos) >> 20) & 0xff;
288 if (m->m_len < sizeof(*ip)) {
289 m = m_pullup(m, sizeof(*ip));
290 if (!m)
291 return IPPROTO_DONE;
292 }
293 ip = mtod(m, struct ip *);
294 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
295 ECN_ALLOWED : ECN_NOCARE,
296 &otos8, &ip->ip_tos) == 0) {
297 m_freem(m);
298 return IPPROTO_DONE;
299 }
300 break;
301 }
302 #endif /* INET */
303 #ifdef INET6
304 case IPPROTO_IPV6:
305 {
306 struct ip6_hdr *ip6;
307 af = AF_INET6;
308 if (m->m_len < sizeof(*ip6)) {
309 m = m_pullup(m, sizeof(*ip6));
310 if (!m)
311 return IPPROTO_DONE;
312 }
313 ip6 = mtod(m, struct ip6_hdr *);
314 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
315 ECN_ALLOWED : ECN_NOCARE,
316 &otos, &ip6->ip6_flow) == 0) {
317 m_freem(m);
318 return IPPROTO_DONE;
319 }
320 break;
321 }
322 #endif
323 case IPPROTO_ETHERIP:
324 af = AF_LINK;
325 break;
326
327 default:
328 ip6stat.ip6s_nogif++;
329 m_freem(m);
330 return IPPROTO_DONE;
331 }
332
333 gif_input(m, af, gifp);
334 return IPPROTO_DONE;
335 }
336
337 /*
338 * validate outer address.
339 */
340 static int
341 gif_validate6(ip6, sc, ifp)
342 const struct ip6_hdr *ip6;
343 struct gif_softc *sc;
344 struct ifnet *ifp;
345 {
346 struct sockaddr_in6 *src, *dst;
347
348 src = (struct sockaddr_in6 *)sc->gif_psrc;
349 dst = (struct sockaddr_in6 *)sc->gif_pdst;
350
351 /*
352 * Check for address match. Note that the check is for an incoming
353 * packet. We should compare the *source* address in our configuration
354 * and the *destination* address of the packet, and vice versa.
355 */
356 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
357 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
358 return 0;
359
360 /* martian filters on outer source - done in ip6_input */
361
362 /* ingress filters on outer source */
363 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
364 struct sockaddr_in6 sin6;
365 struct rtentry *rt;
366
367 bzero(&sin6, sizeof(sin6));
368 sin6.sin6_family = AF_INET6;
369 sin6.sin6_len = sizeof(struct sockaddr_in6);
370 sin6.sin6_addr = ip6->ip6_src;
371 sin6.sin6_scope_id = 0; /* XXX */
372
373 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
374 if (!rt || rt->rt_ifp != ifp) {
375 #if 0
376 log(LOG_WARNING, "%s: packet from %s dropped "
377 "due to ingress filter\n", if_name(GIF2IFP(sc)),
378 ip6_sprintf(&sin6.sin6_addr));
379 #endif
380 if (rt)
381 rtfree(rt);
382 return 0;
383 }
384 rtfree(rt);
385 }
386
387 return 128 * 2;
388 }
389
390 /*
391 * we know that we are in IFF_UP, outer address available, and outer family
392 * matched the physical addr family. see gif_encapcheck().
393 * sanity check for arg should have been done in the caller.
394 */
395 int
396 gif_encapcheck6(m, off, proto, arg)
397 const struct mbuf *m;
398 int off;
399 int proto;
400 void *arg;
401 {
402 struct ip6_hdr ip6;
403 struct gif_softc *sc;
404 struct ifnet *ifp;
405
406 /* sanity check done in caller */
407 sc = (struct gif_softc *)arg;
408
409 /* LINTED const cast */
410 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
411 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
412
413 return gif_validate6(&ip6, sc, ifp);
414 }
415
416 int
417 in6_gif_attach(sc)
418 struct gif_softc *sc;
419 {
420 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
421 (struct protosw *)&in6_gif_protosw, sc);
422 if (sc->encap_cookie6 == NULL)
423 return EEXIST;
424 return 0;
425 }
426
427 int
428 in6_gif_detach(sc)
429 struct gif_softc *sc;
430 {
431 int error;
432
433 error = encap_detach(sc->encap_cookie6);
434 if (error == 0)
435 sc->encap_cookie6 = NULL;
436 return error;
437 }
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