1/*
2 * Copyright (c) 2009-2016 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
98int
99in6_gif_output(
100 struct ifnet *ifp,
101 int family, /* family of the packet to be encapsulate. */
102 struct mbuf *m,
103 __unused struct rtentry *rt)
104{
105 struct gif_softc *sc = ifnet_softc(ifp);
106 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
107 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)
108 (void *)sc->gif_psrc;
109 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)
110 (void *)sc->gif_pdst;
111 struct ip6_hdr *ip6;
112 int proto;
113 u_int8_t itos, otos;
114
115 GIF_LOCK_ASSERT(sc);
116
117 if (sin6_src == NULL || sin6_dst == NULL ||
118 sin6_src->sin6_family != AF_INET6 ||
119 sin6_dst->sin6_family != AF_INET6) {
120 m_freem(m);
121 return (EAFNOSUPPORT);
122 }
123
124 switch (family) {
125#if INET
126 case AF_INET:
127 {
128 struct ip *ip;
129
130 proto = IPPROTO_IPV4;
131 if (mbuf_len(m) < sizeof (*ip)) {
132 m = m_pullup(m, sizeof (*ip));
133 if (!m)
134 return (ENOBUFS);
135 }
136 ip = mtod(m, struct ip *);
137 itos = ip->ip_tos;
138 break;
139 }
140#endif
141#if INET6
142 case AF_INET6:
143 {
144 proto = IPPROTO_IPV6;
145 if (mbuf_len(m) < sizeof (*ip6)) {
146 m = m_pullup(m, sizeof (*ip6));
147 if (!m)
148 return (ENOBUFS);
149 }
150 ip6 = mtod(m, struct ip6_hdr *);
151 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
152 break;
153 }
154#endif
155 default:
156#if DEBUG
157 printf("in6_gif_output: warning: unknown family %d passed\n",
158 family);
159#endif
160 m_freem(m);
161 return (EAFNOSUPPORT);
162 }
163
164 /* prepend new IP header */
165 M_PREPEND(m, sizeof (struct ip6_hdr), M_DONTWAIT, 1);
166 if (m && mbuf_len(m) < sizeof (struct ip6_hdr))
167 m = m_pullup(m, sizeof (struct ip6_hdr));
168 if (m == NULL) {
169 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
170 return (ENOBUFS);
171 }
172
173 ip6 = mtod(m, struct ip6_hdr *);
174 ip6->ip6_flow = 0;
175 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
176 ip6->ip6_vfc |= IPV6_VERSION;
177 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
178 ip6->ip6_nxt = proto;
179 ip6->ip6_hlim = ip6_gif_hlim;
180 ip6->ip6_src = sin6_src->sin6_addr;
181 /* bidirectional configured tunnel mode */
182 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
183 ip6->ip6_dst = sin6_dst->sin6_addr;
184 else {
185 m_freem(m);
186 return (ENETUNREACH);
187 }
188 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_NORMAL : ECN_NOCARE,
189 &otos, &itos);
190 ip6->ip6_flow &= ~htonl(0xff << 20);
191 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
192
193 if (ROUTE_UNUSABLE(&sc->gif_ro6) ||
194 dst->sin6_family != sin6_dst->sin6_family ||
195 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr) ||
196 (sc->gif_ro6.ro_rt != NULL && sc->gif_ro6.ro_rt->rt_ifp == ifp)) {
197 /* cache route doesn't match or recursive route */
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 ROUTE_RELEASE(&sc->gif_ro6);
203#if 0
204 sc->gif_if.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 RT_LOCK(sc->gif_ro6.ro_rt);
215 /* if it constitutes infinite encapsulation, punt. */
216 if (sc->gif_ro6.ro_rt->rt_ifp == ifp) {
217 RT_UNLOCK(sc->gif_ro6.ro_rt);
218 m_freem(m);
219 return (ENETUNREACH); /* XXX */
220 }
221#if 0
222 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
223 - sizeof (struct ip6_hdr);
224#endif
225 RT_UNLOCK(sc->gif_ro6.ro_rt);
226 }
227
228#if IPV6_MINMTU
229 /*
230 * force fragmentation to minimum MTU, to avoid path MTU discovery.
231 * it is too painful to ask for resend of inner packet, to achieve
232 * path MTU discovery for encapsulated packets.
233 */
234 return (ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL));
235#else
236 return (ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL));
237#endif
238}
239
240int
241in6_gif_input(struct mbuf **mp, int *offp, int proto)
242{
243 struct mbuf *m = *mp;
244 struct ifnet *gifp = NULL;
245 struct ip6_hdr *ip6;
246 int af = 0;
247 u_int32_t otos;
248 int egress_success = 0;
249
250 ip6 = mtod(m, struct ip6_hdr *);
251
252 gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
253
254 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
255 m_freem(m);
256 ip6stat.ip6s_nogif++;
257 return (IPPROTO_DONE);
258 }
259
260 otos = ip6->ip6_flow;
261 m_adj(m, *offp);
262
263 switch (proto) {
264#if INET
265 case IPPROTO_IPV4:
266 {
267 struct ip *ip;
268 u_int8_t otos8, old_tos;
269 int sum;
270
271 af = AF_INET;
272 otos8 = (ntohl(otos) >> 20) & 0xff;
273 if (mbuf_len(m) < sizeof (*ip)) {
274 m = m_pullup(m, sizeof (*ip));
275 if (!m)
276 return (IPPROTO_DONE);
277 }
278 ip = mtod(m, struct ip *);
279 if (gifp->if_flags & IFF_LINK1) {
280 old_tos = ip->ip_tos;
281 egress_success = ip_ecn_egress(ECN_NORMAL, &otos8, &ip->ip_tos);
282 if (old_tos != ip->ip_tos) {
283 sum = ~ntohs(ip->ip_sum) & 0xffff;
284 sum += (~old_tos & 0xffff) + ip->ip_tos;
285 sum = (sum >> 16) + (sum & 0xffff);
286 sum += (sum >> 16); /* add carry */
287 ip->ip_sum = htons(~sum & 0xffff);
288 }
289 } else
290 egress_success = ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
291 break;
292 }
293#endif /* INET */
294#if INET6
295 case IPPROTO_IPV6:
296 {
297 af = AF_INET6;
298 if (mbuf_len(m) < sizeof (*ip6)) {
299 m = m_pullup(m, sizeof (*ip6));
300 if (!m)
301 return (IPPROTO_DONE);
302 }
303 ip6 = mtod(m, struct ip6_hdr *);
304 if (gifp->if_flags & IFF_LINK1)
305 egress_success = ip6_ecn_egress(ECN_NORMAL, &otos, &ip6->ip6_flow);
306 else
307 egress_success = ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
308 break;
309 }
310#endif
311 default:
312 ip6stat.ip6s_nogif++;
313 m_freem(m);
314 return (IPPROTO_DONE);
315 }
316
317 if (egress_success == 0) {
318 ip6stat.ip6s_nogif++;
319 m_freem(m);
320 return (IPPROTO_DONE);
321 }
322
323 /* Replace the rcvif by gifp for ifnet_input to route it correctly */
324 if (m->m_pkthdr.rcvif)
325 m->m_pkthdr.rcvif = gifp;
326
327 ifnet_input(gifp, m, NULL);
328 return (IPPROTO_DONE);
329}
330
331/*
332 * validate outer address.
333 */
334static int
335gif_validate6(
336 const struct ip6_hdr *ip6,
337 struct gif_softc *sc,
338 struct ifnet *ifp)
339{
340 struct sockaddr_in6 *src, *dst;
341
342 src = (struct sockaddr_in6 *)(void *)sc->gif_psrc;
343 dst = (struct sockaddr_in6 *)(void *)sc->gif_pdst;
344
345 /*
346 * Check for address match. Note that the check is for an incoming
347 * packet. We should compare the *source* address in our configuration
348 * and the *destination* address of the packet, and vice versa.
349 */
350 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
351 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
352 return (0);
353
354 /* martian filters on outer source - done in ip6_input */
355
356 /* ingress filters on outer source */
357 if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 && ifp) {
358 struct sockaddr_in6 sin6;
359 struct rtentry *rt;
360
361 bzero(&sin6, sizeof (sin6));
362 sin6.sin6_family = AF_INET6;
363 sin6.sin6_len = sizeof (struct sockaddr_in6);
364 sin6.sin6_addr = ip6->ip6_src;
365
366 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0);
367 if (rt != NULL)
368 RT_LOCK(rt);
369 if (!rt || rt->rt_ifp != ifp) {
370#if 0
371 log(LOG_WARNING, "%s: packet from %s dropped "
372 "due to ingress filter\n", if_name(&sc->gif_if),
373 ip6_sprintf(&sin6.sin6_addr));
374#endif
375 if (rt != NULL) {
376 RT_UNLOCK(rt);
377 rtfree(rt);
378 }
379 return (0);
380 }
381 RT_UNLOCK(rt);
382 rtfree(rt);
383 }
384
385 return (128 * 2);
386}
387
388/*
389 * we know that we are in IFF_UP, outer address available, and outer family
390 * matched the physical addr family. see gif_encapcheck().
391 * sanity check for arg should have been done in the caller.
392 */
393int
394gif_encapcheck6(
395 const struct mbuf *m,
396 __unused int off,
397 __unused int proto,
398 void *arg)
399{
400 struct ip6_hdr ip6;
401 struct gif_softc *sc;
402 struct ifnet *ifp;
403
404 /* sanity check done in caller */
405 sc = (struct gif_softc *)arg;
406
407 GIF_LOCK_ASSERT(sc);
408
409 mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof (ip6), &ip6);
410 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
411
412 return (gif_validate6(&ip6, sc, ifp));
413}
414