1 /* $FreeBSD$ */
2 /* $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ */
3
4 /*-
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/socket.h>
39 #include <sys/sockio.h>
40 #include <sys/mbuf.h>
41 #include <sys/errno.h>
42 #include <sys/queue.h>
43 #include <sys/syslog.h>
44 #include <sys/protosw.h>
45
46 #include <sys/malloc.h>
47
48 #include <net/if.h>
49 #include <net/route.h>
50
51 #include <netinet/in.h>
52 #include <netinet/in_systm.h>
53 #ifdef INET
54 #include <netinet/ip.h>
55 #endif
56 #include <netinet/ip_encap.h>
57 #ifdef INET6
58 #include <netinet/ip6.h>
59 #include <netinet6/ip6_var.h>
60 #include <netinet6/in6_gif.h>
61 #include <netinet6/in6_var.h>
62 #endif
63 #include <netinet6/ip6protosw.h>
64 #include <netinet/ip_ecn.h>
65 #ifdef INET6
66 #include <netinet6/ip6_ecn.h>
67 #endif
68
69 #include <net/if_gif.h>
70
71 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
72 struct ifnet *);
73
74 extern struct domain inet6domain;
75 struct ip6protosw in6_gif_protosw =
76 { SOCK_RAW, &inet6domain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR,
77 in6_gif_input, rip6_output, 0, rip6_ctloutput,
78 0,
79 0, 0, 0, 0,
80 &rip6_usrreqs
81 };
82
83 int
84 in6_gif_output(struct ifnet *ifp,
85 int family, /* family of the packet to be encapsulate */
86 struct mbuf *m)
87 {
88 struct gif_softc *sc = ifp->if_softc;
89 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
90 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
91 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
92 struct ip6_hdr *ip6;
93 struct etherip_header eiphdr;
94 int proto, error;
95 u_int8_t itos, otos;
96
97 GIF_LOCK_ASSERT(sc);
98
99 if (sin6_src == NULL || sin6_dst == NULL ||
100 sin6_src->sin6_family != AF_INET6 ||
101 sin6_dst->sin6_family != AF_INET6) {
102 m_freem(m);
103 return EAFNOSUPPORT;
104 }
105
106 switch (family) {
107 #ifdef INET
108 case AF_INET:
109 {
110 struct ip *ip;
111
112 proto = IPPROTO_IPV4;
113 if (m->m_len < sizeof(*ip)) {
114 m = m_pullup(m, sizeof(*ip));
115 if (!m)
116 return ENOBUFS;
117 }
118 ip = mtod(m, struct ip *);
119 itos = ip->ip_tos;
120 break;
121 }
122 #endif
123 #ifdef INET6
124 case AF_INET6:
125 {
126 struct ip6_hdr *ip6;
127 proto = IPPROTO_IPV6;
128 if (m->m_len < sizeof(*ip6)) {
129 m = m_pullup(m, sizeof(*ip6));
130 if (!m)
131 return ENOBUFS;
132 }
133 ip6 = mtod(m, struct ip6_hdr *);
134 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
135 break;
136 }
137 #endif
138 case AF_LINK:
139 proto = IPPROTO_ETHERIP;
140 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
141 eiphdr.eip_pad = 0;
142 /* prepend Ethernet-in-IP header */
143 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
144 if (m && m->m_len < sizeof(struct etherip_header))
145 m = m_pullup(m, sizeof(struct etherip_header));
146 if (m == NULL)
147 return ENOBUFS;
148 bcopy(&eiphdr, mtod(m, struct etherip_header *),
149 sizeof(struct etherip_header));
150 break;
151
152 default:
153 #ifdef DEBUG
154 printf("in6_gif_output: warning: unknown family %d passed\n",
155 family);
156 #endif
157 m_freem(m);
158 return EAFNOSUPPORT;
159 }
160
161 /* prepend new IP header */
162 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
163 if (m && m->m_len < sizeof(struct ip6_hdr))
164 m = m_pullup(m, sizeof(struct ip6_hdr));
165 if (m == NULL) {
166 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
167 return ENOBUFS;
168 }
169
170 ip6 = mtod(m, struct ip6_hdr *);
171 ip6->ip6_flow = 0;
172 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
173 ip6->ip6_vfc |= IPV6_VERSION;
174 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
175 ip6->ip6_nxt = proto;
176 ip6->ip6_hlim = ip6_gif_hlim;
177 ip6->ip6_src = sin6_src->sin6_addr;
178 /* bidirectional configured tunnel mode */
179 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
180 ip6->ip6_dst = sin6_dst->sin6_addr;
181 else {
182 m_freem(m);
183 return ENETUNREACH;
184 }
185 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
186 &otos, &itos);
187 ip6->ip6_flow &= ~htonl(0xff << 20);
188 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
189
190 if (dst->sin6_family != sin6_dst->sin6_family ||
191 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
192 /* cache route doesn't match */
193 bzero(dst, sizeof(*dst));
194 dst->sin6_family = sin6_dst->sin6_family;
195 dst->sin6_len = sizeof(struct sockaddr_in6);
196 dst->sin6_addr = sin6_dst->sin6_addr;
197 if (sc->gif_ro6.ro_rt) {
198 RTFREE(sc->gif_ro6.ro_rt);
199 sc->gif_ro6.ro_rt = NULL;
200 }
201 #if 0
202 GIF2IFP(sc)->if_mtu = GIF_MTU;
203 #endif
204 }
205
206 if (sc->gif_ro6.ro_rt == NULL) {
207 rtalloc((struct route *)&sc->gif_ro6);
208 if (sc->gif_ro6.ro_rt == NULL) {
209 m_freem(m);
210 return ENETUNREACH;
211 }
212
213 /* if it constitutes infinite encapsulation, punt. */
214 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
215 m_freem(m);
216 return ENETUNREACH; /*XXX*/
217 }
218 #if 0
219 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
220 - sizeof(struct ip6_hdr);
221 #endif
222 }
223
224 #ifdef IPV6_MINMTU
225 /*
226 * force fragmentation to minimum MTU, to avoid path MTU discovery.
227 * it is too painful to ask for resend of inner packet, to achieve
228 * path MTU discovery for encapsulated packets.
229 */
230 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
231 #else
232 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
233 #endif
234
235 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
236 sc->gif_ro6.ro_rt != NULL) {
237 RTFREE(sc->gif_ro6.ro_rt);
238 sc->gif_ro6.ro_rt = NULL;
239 }
240
241 return (error);
242 }
243
244 int
245 in6_gif_input(struct mbuf **mp, int *offp, int proto)
246 {
247 struct mbuf *m = *mp;
248 struct ifnet *gifp = NULL;
249 struct gif_softc *sc;
250 struct ip6_hdr *ip6;
251 int af = 0;
252 u_int32_t otos;
253
254 ip6 = mtod(m, struct ip6_hdr *);
255
256 sc = (struct gif_softc *)encap_getarg(m);
257 if (sc == NULL) {
258 m_freem(m);
259 ip6stat.ip6s_nogif++;
260 return IPPROTO_DONE;
261 }
262
263 gifp = GIF2IFP(sc);
264 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
265 m_freem(m);
266 ip6stat.ip6s_nogif++;
267 return IPPROTO_DONE;
268 }
269
270 otos = ip6->ip6_flow;
271 m_adj(m, *offp);
272
273 switch (proto) {
274 #ifdef INET
275 case IPPROTO_IPV4:
276 {
277 struct ip *ip;
278 u_int8_t otos8;
279 af = AF_INET;
280 otos8 = (ntohl(otos) >> 20) & 0xff;
281 if (m->m_len < sizeof(*ip)) {
282 m = m_pullup(m, sizeof(*ip));
283 if (!m)
284 return IPPROTO_DONE;
285 }
286 ip = mtod(m, struct ip *);
287 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
288 ECN_ALLOWED : ECN_NOCARE,
289 &otos8, &ip->ip_tos) == 0) {
290 m_freem(m);
291 return IPPROTO_DONE;
292 }
293 break;
294 }
295 #endif /* INET */
296 #ifdef INET6
297 case IPPROTO_IPV6:
298 {
299 struct ip6_hdr *ip6;
300 af = AF_INET6;
301 if (m->m_len < sizeof(*ip6)) {
302 m = m_pullup(m, sizeof(*ip6));
303 if (!m)
304 return IPPROTO_DONE;
305 }
306 ip6 = mtod(m, struct ip6_hdr *);
307 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
308 ECN_ALLOWED : ECN_NOCARE,
309 &otos, &ip6->ip6_flow) == 0) {
310 m_freem(m);
311 return IPPROTO_DONE;
312 }
313 break;
314 }
315 #endif
316 case IPPROTO_ETHERIP:
317 af = AF_LINK;
318 break;
319
320 default:
321 ip6stat.ip6s_nogif++;
322 m_freem(m);
323 return IPPROTO_DONE;
324 }
325
326 gif_input(m, af, gifp);
327 return IPPROTO_DONE;
328 }
329
330 /*
331 * validate outer address.
332 */
333 static int
334 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
335 struct ifnet *ifp)
336 {
337 struct sockaddr_in6 *src, *dst;
338
339 src = (struct sockaddr_in6 *)sc->gif_psrc;
340 dst = (struct sockaddr_in6 *)sc->gif_pdst;
341
342 /*
343 * Check for address match. Note that the check is for an incoming
344 * packet. We should compare the *source* address in our configuration
345 * and the *destination* address of the packet, and vice versa.
346 */
347 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
348 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
349 return 0;
350
351 /* martian filters on outer source - done in ip6_input */
352
353 /* ingress filters on outer source */
354 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
355 struct sockaddr_in6 sin6;
356 struct rtentry *rt;
357
358 bzero(&sin6, sizeof(sin6));
359 sin6.sin6_family = AF_INET6;
360 sin6.sin6_len = sizeof(struct sockaddr_in6);
361 sin6.sin6_addr = ip6->ip6_src;
362 sin6.sin6_scope_id = 0; /* XXX */
363
364 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
365 if (!rt || rt->rt_ifp != ifp) {
366 #if 0
367 char ip6buf[INET6_ADDRSTRLEN];
368 log(LOG_WARNING, "%s: packet from %s dropped "
369 "due to ingress filter\n", if_name(GIF2IFP(sc)),
370 ip6_sprintf(ip6buf, &sin6.sin6_addr));
371 #endif
372 if (rt)
373 rtfree(rt);
374 return 0;
375 }
376 rtfree(rt);
377 }
378
379 return 128 * 2;
380 }
381
382 /*
383 * we know that we are in IFF_UP, outer address available, and outer family
384 * matched the physical addr family. see gif_encapcheck().
385 * sanity check for arg should have been done in the caller.
386 */
387 int
388 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
389 {
390 struct ip6_hdr ip6;
391 struct gif_softc *sc;
392 struct ifnet *ifp;
393
394 /* sanity check done in caller */
395 sc = (struct gif_softc *)arg;
396
397 /* LINTED const cast */
398 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
399 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
400
401 return gif_validate6(&ip6, sc, ifp);
402 }
403
404 int
405 in6_gif_attach(struct gif_softc *sc)
406 {
407 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
408 (void *)&in6_gif_protosw, sc);
409 if (sc->encap_cookie6 == NULL)
410 return EEXIST;
411 return 0;
412 }
413
414 int
415 in6_gif_detach(struct gif_softc *sc)
416 {
417 int error;
418
419 error = encap_detach(sc->encap_cookie6);
420 if (error == 0)
421 sc->encap_cookie6 = NULL;
422 return error;
423 }
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