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