1 /* $FreeBSD: releng/5.2/sys/netinet6/in6_gif.c 121684 2003-10-29 15:07:04Z ume $ */
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 #include <net/net_osdep.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(ifp, family, m)
87 struct ifnet *ifp;
88 int family; /* family of the packet to be encapsulate. */
89 struct mbuf *m;
90 {
91 struct gif_softc *sc = (struct gif_softc*)ifp;
92 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
93 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
94 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
95 struct ip6_hdr *ip6;
96 int proto;
97 u_int8_t itos, otos;
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 default:
139 #ifdef DEBUG
140 printf("in6_gif_output: warning: unknown family %d passed\n",
141 family);
142 #endif
143 m_freem(m);
144 return EAFNOSUPPORT;
145 }
146
147 /* prepend new IP header */
148 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
149 if (m && m->m_len < sizeof(struct ip6_hdr))
150 m = m_pullup(m, sizeof(struct ip6_hdr));
151 if (m == NULL) {
152 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
153 return ENOBUFS;
154 }
155
156 ip6 = mtod(m, struct ip6_hdr *);
157 ip6->ip6_flow = 0;
158 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
159 ip6->ip6_vfc |= IPV6_VERSION;
160 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
161 ip6->ip6_nxt = proto;
162 ip6->ip6_hlim = ip6_gif_hlim;
163 ip6->ip6_src = sin6_src->sin6_addr;
164 /* bidirectional configured tunnel mode */
165 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
166 ip6->ip6_dst = sin6_dst->sin6_addr;
167 else {
168 m_freem(m);
169 return ENETUNREACH;
170 }
171 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
172 &otos, &itos);
173 ip6->ip6_flow &= ~htonl(0xff << 20);
174 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
175
176 if (dst->sin6_family != sin6_dst->sin6_family ||
177 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
178 /* cache route doesn't match */
179 bzero(dst, sizeof(*dst));
180 dst->sin6_family = sin6_dst->sin6_family;
181 dst->sin6_len = sizeof(struct sockaddr_in6);
182 dst->sin6_addr = sin6_dst->sin6_addr;
183 if (sc->gif_ro6.ro_rt) {
184 RTFREE(sc->gif_ro6.ro_rt);
185 sc->gif_ro6.ro_rt = NULL;
186 }
187 #if 0
188 sc->gif_if.if_mtu = GIF_MTU;
189 #endif
190 }
191
192 if (sc->gif_ro6.ro_rt == NULL) {
193 rtalloc((struct route *)&sc->gif_ro6);
194 if (sc->gif_ro6.ro_rt == NULL) {
195 m_freem(m);
196 return ENETUNREACH;
197 }
198
199 /* if it constitutes infinite encapsulation, punt. */
200 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
201 m_freem(m);
202 return ENETUNREACH; /*XXX*/
203 }
204 #if 0
205 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
206 - sizeof(struct ip6_hdr);
207 #endif
208 }
209
210 #ifdef IPV6_MINMTU
211 /*
212 * force fragmentation to minimum MTU, to avoid path MTU discovery.
213 * it is too painful to ask for resend of inner packet, to achieve
214 * path MTU discovery for encapsulated packets.
215 */
216 return (ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL));
217 #else
218 return (ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL));
219 #endif
220 }
221
222 int
223 in6_gif_input(mp, offp, proto)
224 struct mbuf **mp;
225 int *offp, proto;
226 {
227 struct mbuf *m = *mp;
228 struct ifnet *gifp = NULL;
229 struct ip6_hdr *ip6;
230 int af = 0;
231 u_int32_t otos;
232
233 ip6 = mtod(m, struct ip6_hdr *);
234
235 gifp = (struct ifnet *)encap_getarg(m);
236
237 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
238 m_freem(m);
239 ip6stat.ip6s_nogif++;
240 return IPPROTO_DONE;
241 }
242
243 otos = ip6->ip6_flow;
244 m_adj(m, *offp);
245
246 switch (proto) {
247 #ifdef INET
248 case IPPROTO_IPV4:
249 {
250 struct ip *ip;
251 u_int8_t otos8;
252 af = AF_INET;
253 otos8 = (ntohl(otos) >> 20) & 0xff;
254 if (m->m_len < sizeof(*ip)) {
255 m = m_pullup(m, sizeof(*ip));
256 if (!m)
257 return IPPROTO_DONE;
258 }
259 ip = mtod(m, struct ip *);
260 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
261 ECN_ALLOWED : ECN_NOCARE,
262 &otos8, &ip->ip_tos) == 0) {
263 m_freem(m);
264 return IPPROTO_DONE;
265 }
266 break;
267 }
268 #endif /* INET */
269 #ifdef INET6
270 case IPPROTO_IPV6:
271 {
272 struct ip6_hdr *ip6;
273 af = AF_INET6;
274 if (m->m_len < sizeof(*ip6)) {
275 m = m_pullup(m, sizeof(*ip6));
276 if (!m)
277 return IPPROTO_DONE;
278 }
279 ip6 = mtod(m, struct ip6_hdr *);
280 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
281 ECN_ALLOWED : ECN_NOCARE,
282 &otos, &ip6->ip6_flow) == 0) {
283 m_freem(m);
284 return IPPROTO_DONE;
285 }
286 break;
287 }
288 #endif
289 default:
290 ip6stat.ip6s_nogif++;
291 m_freem(m);
292 return IPPROTO_DONE;
293 }
294
295 gif_input(m, af, gifp);
296 return IPPROTO_DONE;
297 }
298
299 /*
300 * validate outer address.
301 */
302 static int
303 gif_validate6(ip6, sc, ifp)
304 const struct ip6_hdr *ip6;
305 struct gif_softc *sc;
306 struct ifnet *ifp;
307 {
308 struct sockaddr_in6 *src, *dst;
309
310 src = (struct sockaddr_in6 *)sc->gif_psrc;
311 dst = (struct sockaddr_in6 *)sc->gif_pdst;
312
313 /*
314 * Check for address match. Note that the check is for an incoming
315 * packet. We should compare the *source* address in our configuration
316 * and the *destination* address of the packet, and vice versa.
317 */
318 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
319 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
320 return 0;
321
322 /* martian filters on outer source - done in ip6_input */
323
324 /* ingress filters on outer source */
325 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
326 struct sockaddr_in6 sin6;
327 struct rtentry *rt;
328
329 bzero(&sin6, sizeof(sin6));
330 sin6.sin6_family = AF_INET6;
331 sin6.sin6_len = sizeof(struct sockaddr_in6);
332 sin6.sin6_addr = ip6->ip6_src;
333 sin6.sin6_scope_id = 0; /* XXX */
334
335 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
336 if (!rt || rt->rt_ifp != ifp) {
337 #if 0
338 log(LOG_WARNING, "%s: packet from %s dropped "
339 "due to ingress filter\n", if_name(&sc->gif_if),
340 ip6_sprintf(&sin6.sin6_addr));
341 #endif
342 if (rt)
343 rtfree(rt);
344 return 0;
345 }
346 rtfree(rt);
347 }
348
349 return 128 * 2;
350 }
351
352 /*
353 * we know that we are in IFF_UP, outer address available, and outer family
354 * matched the physical addr family. see gif_encapcheck().
355 * sanity check for arg should have been done in the caller.
356 */
357 int
358 gif_encapcheck6(m, off, proto, arg)
359 const struct mbuf *m;
360 int off;
361 int proto;
362 void *arg;
363 {
364 struct ip6_hdr ip6;
365 struct gif_softc *sc;
366 struct ifnet *ifp;
367
368 /* sanity check done in caller */
369 sc = (struct gif_softc *)arg;
370
371 /* LINTED const cast */
372 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
373 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
374
375 return gif_validate6(&ip6, sc, ifp);
376 }
377
378 int
379 in6_gif_attach(sc)
380 struct gif_softc *sc;
381 {
382 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
383 (struct protosw *)&in6_gif_protosw, sc);
384 if (sc->encap_cookie6 == NULL)
385 return EEXIST;
386 return 0;
387 }
388
389 int
390 in6_gif_detach(sc)
391 struct gif_softc *sc;
392 {
393 int error;
394
395 error = encap_detach(sc->encap_cookie6);
396 if (error == 0)
397 sc->encap_cookie6 = NULL;
398 return error;
399 }
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