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1 /*
2 * Copyright (c) 2008 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 /* $FreeBSD: src/sys/netinet6/in6_gif.c,v 1.2.2.3 2001/07/03 11:01:52 ume Exp $ */
30 /* $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ */
31
32 /*
33 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 * 3. Neither the name of the project nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 */
60
61
62 #include <sys/param.h>
63 #include <sys/systm.h>
64 #include <sys/socket.h>
65 #include <sys/sockio.h>
66 #include <sys/mbuf.h>
67 #include <sys/errno.h>
68 #include <sys/queue.h>
69 #include <sys/syslog.h>
70
71 #include <sys/malloc.h>
72 #include <sys/protosw.h>
73
74 #include <net/if.h>
75 #include <net/route.h>
76
77 #include <netinet/in.h>
78 #include <netinet/in_systm.h>
79 #if INET
80 #include <netinet/ip.h>
81 #endif
82 #include <netinet/ip_encap.h>
83 #if INET6
84 #include <netinet/ip6.h>
85 #include <netinet6/ip6_var.h>
86 #include <netinet6/in6_gif.h>
87 #include <netinet6/in6_var.h>
88 #endif
89 #include <netinet/ip_ecn.h>
90 #if INET6
91 #include <netinet6/ip6_ecn.h>
92 #endif
93
94 #include <net/if_gif.h>
95
96 #include <net/net_osdep.h>
97
98 static __inline__ void*
99 _cast_non_const(const void * ptr) {
100 union {
101 const void* cval;
102 void* val;
103 } ret;
104
105 ret.cval = ptr;
106 return (ret.val);
107 }
108
109 int
110 in6_gif_output(
111 struct ifnet *ifp,
112 int family, /* family of the packet to be encapsulate. */
113 struct mbuf *m,
114 __unused struct rtentry *rt)
115 {
116 struct gif_softc *sc = ifnet_softc(ifp);
117 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
118 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
119 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
120 struct ip6_hdr *ip6;
121 int proto;
122 u_int8_t itos, otos;
123
124 if (sin6_src == NULL || sin6_dst == NULL ||
125 sin6_src->sin6_family != AF_INET6 ||
126 sin6_dst->sin6_family != AF_INET6) {
127 m_freem(m);
128 return EAFNOSUPPORT;
129 }
130
131 switch (family) {
132 #if INET
133 case AF_INET:
134 {
135 struct ip *ip;
136
137 proto = IPPROTO_IPV4;
138 if (mbuf_len(m) < sizeof(*ip)) {
139 m = m_pullup(m, sizeof(*ip));
140 if (!m)
141 return ENOBUFS;
142 }
143 ip = mtod(m, struct ip *);
144 itos = ip->ip_tos;
145 break;
146 }
147 #endif
148 #if INET6
149 case AF_INET6:
150 {
151 proto = IPPROTO_IPV6;
152 if (mbuf_len(m) < sizeof(*ip6)) {
153 m = m_pullup(m, sizeof(*ip6));
154 if (!m)
155 return ENOBUFS;
156 }
157 ip6 = mtod(m, struct ip6_hdr *);
158 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
159 break;
160 }
161 #endif
162 default:
163 #if DEBUG
164 printf("in6_gif_output: warning: unknown family %d passed\n",
165 family);
166 #endif
167 m_freem(m);
168 return EAFNOSUPPORT;
169 }
170
171 /* prepend new IP header */
172 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
173 if (m && mbuf_len(m) < sizeof(struct ip6_hdr))
174 m = m_pullup(m, sizeof(struct ip6_hdr));
175 if (m == NULL) {
176 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
177 return ENOBUFS;
178 }
179
180 ip6 = mtod(m, struct ip6_hdr *);
181 ip6->ip6_flow = 0;
182 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
183 ip6->ip6_vfc |= IPV6_VERSION;
184 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
185 ip6->ip6_nxt = proto;
186 ip6->ip6_hlim = ip6_gif_hlim;
187 ip6->ip6_src = sin6_src->sin6_addr;
188 /* bidirectional configured tunnel mode */
189 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
190 ip6->ip6_dst = sin6_dst->sin6_addr;
191 else {
192 m_freem(m);
193 return ENETUNREACH;
194 }
195 if (ifp->if_flags & IFF_LINK1)
196 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
197 else
198 ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
199 ip6->ip6_flow &= ~ntohl(0xff00000);
200 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
201
202 if (dst->sin6_family != sin6_dst->sin6_family ||
203 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr) ||
204 (sc->gif_ro6.ro_rt != NULL &&
205 (sc->gif_ro6.ro_rt->generation_id != route_generation ||
206 sc->gif_ro6.ro_rt->rt_ifp == ifp))) {
207 /* cache route doesn't match or recursive route */
208 bzero(dst, sizeof(*dst));
209 dst->sin6_family = sin6_dst->sin6_family;
210 dst->sin6_len = sizeof(struct sockaddr_in6);
211 dst->sin6_addr = sin6_dst->sin6_addr;
212 if (sc->gif_ro6.ro_rt) {
213 rtfree(sc->gif_ro6.ro_rt);
214 sc->gif_ro6.ro_rt = NULL;
215 }
216 #if 0
217 sc->gif_if.if_mtu = GIF_MTU;
218 #endif
219 }
220
221 if (sc->gif_ro6.ro_rt == NULL) {
222 rtalloc((struct route *)&sc->gif_ro6);
223 if (sc->gif_ro6.ro_rt == NULL) {
224 m_freem(m);
225 return ENETUNREACH;
226 }
227 RT_LOCK(sc->gif_ro6.ro_rt);
228 /* if it constitutes infinite encapsulation, punt. */
229 if (sc->gif_ro6.ro_rt->rt_ifp == ifp) {
230 RT_UNLOCK(sc->gif_ro6.ro_rt);
231 m_freem(m);
232 return ENETUNREACH; /*XXX*/
233 }
234 #if 0
235 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
236 - sizeof(struct ip6_hdr);
237 #endif
238 RT_UNLOCK(sc->gif_ro6.ro_rt);
239 }
240
241 #if IPV6_MINMTU
242 /*
243 * force fragmentation to minimum MTU, to avoid path MTU discovery.
244 * it is too painful to ask for resend of inner packet, to achieve
245 * path MTU discovery for encapsulated packets.
246 */
247 return(ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, 0));
248 #else
249 return(ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, 0));
250 #endif
251 }
252
253 int in6_gif_input(mp, offp)
254 struct mbuf **mp;
255 int *offp;
256 {
257 struct mbuf *m = *mp;
258 struct ifnet *gifp = NULL;
259 struct ip6_hdr *ip6;
260 int af = 0;
261 u_int32_t otos;
262 u_int8_t proto;
263
264 ip6 = mtod(m, struct ip6_hdr *);
265
266 gifp = ((struct gif_softc*)encap_getarg(m))->gif_if;
267
268 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
269 m_freem(m);
270 ip6stat.ip6s_nogif++;
271 return IPPROTO_DONE;
272 }
273
274 proto = ip6->ip6_nxt;
275 otos = ip6->ip6_flow;
276 m_adj(m, *offp);
277
278 switch (proto) {
279 #if INET
280 case IPPROTO_IPV4:
281 {
282 struct ip *ip;
283 u_int8_t otos8;
284 af = AF_INET;
285 otos8 = (ntohl(otos) >> 20) & 0xff;
286 if (mbuf_len(m) < sizeof(*ip)) {
287 m = m_pullup(m, sizeof(*ip));
288 if (!m)
289 return IPPROTO_DONE;
290 }
291 ip = mtod(m, struct ip *);
292 if (gifp->if_flags & IFF_LINK1)
293 ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
294 else
295 ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
296 break;
297 }
298 #endif /* INET */
299 #if INET6
300 case IPPROTO_IPV6:
301 {
302 af = AF_INET6;
303 if (mbuf_len(m) < 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 (gifp->if_flags & IFF_LINK1)
310 ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
311 else
312 ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
313 break;
314 }
315 #endif
316 default:
317 ip6stat.ip6s_nogif++;
318 m_freem(m);
319 return IPPROTO_DONE;
320 }
321
322 if (m->m_pkthdr.rcvif) /* replace the rcvif by gifp for ifnet_input to route it correctly */
323 m->m_pkthdr.rcvif = gifp;
324
325 ifnet_input(gifp, m, NULL);
326 return IPPROTO_DONE;
327 }
328
329 /*
330 * validate outer address.
331 */
332 static int
333 gif_validate6(
334 const struct ip6_hdr *ip6,
335 struct gif_softc *sc,
336 struct ifnet *ifp)
337 {
338 struct sockaddr_in6 *src, *dst;
339
340 src = (struct sockaddr_in6 *)sc->gif_psrc;
341 dst = (struct sockaddr_in6 *)sc->gif_pdst;
342
343 /*
344 * Check for address match. Note that the check is for an incoming
345 * packet. We should compare the *source* address in our configuration
346 * and the *destination* address of the packet, and vice versa.
347 */
348 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
349 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
350 return 0;
351
352 /* martian filters on outer source - done in ip6_input */
353
354 /* ingress filters on outer source */
355 if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 && ifp) {
356 struct sockaddr_in6 sin6;
357 struct rtentry *rt;
358
359 bzero(&sin6, sizeof(sin6));
360 sin6.sin6_family = AF_INET6;
361 sin6.sin6_len = sizeof(struct sockaddr_in6);
362 sin6.sin6_addr = ip6->ip6_src;
363 #ifndef SCOPEDROUTING
364 sin6.sin6_scope_id = 0; /* XXX */
365 #endif
366
367 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0);
368 if (rt != NULL)
369 RT_LOCK(rt);
370 if (!rt || rt->rt_ifp != ifp) {
371 #if 0
372 log(LOG_WARNING, "%s: packet from %s dropped "
373 "due to ingress filter\n", if_name(&sc->gif_if),
374 ip6_sprintf(&sin6.sin6_addr));
375 #endif
376 if (rt != NULL) {
377 RT_UNLOCK(rt);
378 rtfree(rt);
379 }
380 return 0;
381 }
382 RT_UNLOCK(rt);
383 rtfree(rt);
384 }
385
386 return 128 * 2;
387 }
388
389 /*
390 * we know that we are in IFF_UP, outer address available, and outer family
391 * matched the physical addr family. see gif_encapcheck().
392 * sanity check for arg should have been done in the caller.
393 */
394 int
395 gif_encapcheck6(
396 const struct mbuf *m,
397 __unused int off,
398 __unused int proto,
399 void *arg)
400 {
401 struct ip6_hdr ip6;
402 struct gif_softc *sc;
403 struct ifnet *ifp;
404
405 /* sanity check done in caller */
406 sc = (struct gif_softc *)arg;
407
408 mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip6), &ip6);
409 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
410
411 return gif_validate6(&ip6, sc, ifp);
412 }