1 /* $FreeBSD: src/sys/netinet6/in6_gif.c,v 1.2.2.7 2003/01/23 21:06:47 sam Exp $ */
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_var.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/gif/if_gif.h>
70
71 #include <net/net_osdep.h>
72
73 #ifdef INET6
74 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
75 struct ifnet *);
76
77 extern struct domain inet6domain;
78 struct protosw in6_gif_protosw =
79 {
80 .pr_type = SOCK_RAW,
81 .pr_domain = &inet6domain,
82 .pr_protocol = 0 /* IPPROTO_IPV[46] */,
83 .pr_flags = PR_ATOMIC|PR_ADDR,
84
85 .pr_input = in6_gif_input,
86 .pr_output = rip6_output,
87 .pr_ctlinput = NULL,
88 .pr_ctloutput = rip6_ctloutput,
89
90 .pr_usrreqs = &rip6_usrreqs
91 };
92
93 /*
94 * family = family of the packet to be encapsulate.
95 */
96 int
in6_gif_output(struct ifnet * ifp,int family,struct mbuf * m)97 in6_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
98 {
99 struct gif_softc *sc = (struct gif_softc*)ifp;
100 struct route_in6 *ro = &sc->gif_ro6[mycpu->gd_cpuid];
101 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&ro->ro_dst;
102 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
103 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
104 struct ip6_hdr *ip6;
105 int proto;
106 u_int8_t itos, otos;
107
108 if (sin6_src == NULL || sin6_dst == NULL ||
109 sin6_src->sin6_family != AF_INET6 ||
110 sin6_dst->sin6_family != AF_INET6) {
111 m_freem(m);
112 return EAFNOSUPPORT;
113 }
114
115 switch (family) {
116 #ifdef INET
117 case AF_INET:
118 {
119 struct ip *ip;
120
121 proto = IPPROTO_IPV4;
122 if (m->m_len < sizeof(*ip)) {
123 m = m_pullup(m, sizeof(*ip));
124 if (!m)
125 return ENOBUFS;
126 }
127 ip = mtod(m, struct ip *);
128 itos = ip->ip_tos;
129 break;
130 }
131 #endif
132 #ifdef INET6
133 case AF_INET6:
134 {
135 struct ip6_hdr *ip6;
136 proto = IPPROTO_IPV6;
137 if (m->m_len < sizeof(*ip6)) {
138 m = m_pullup(m, sizeof(*ip6));
139 if (!m)
140 return ENOBUFS;
141 }
142 ip6 = mtod(m, struct ip6_hdr *);
143 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
144 break;
145 }
146 #endif
147 default:
148 #ifdef DEBUG
149 kprintf("in6_gif_output: warning: unknown family %d passed\n",
150 family);
151 #endif
152 m_freem(m);
153 return EAFNOSUPPORT;
154 }
155
156 /* prepend new IP header */
157 M_PREPEND(m, sizeof(struct ip6_hdr), M_NOWAIT);
158 if (m && m->m_len < sizeof(struct ip6_hdr))
159 m = m_pullup(m, sizeof(struct ip6_hdr));
160 if (m == NULL) {
161 kprintf("ENOBUFS in in6_gif_output %d\n", __LINE__);
162 return ENOBUFS;
163 }
164
165 ip6 = mtod(m, struct ip6_hdr *);
166 ip6->ip6_flow = 0;
167 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
168 ip6->ip6_vfc |= IPV6_VERSION;
169 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
170 ip6->ip6_nxt = proto;
171 ip6->ip6_hlim = ip6_gif_hlim;
172 ip6->ip6_src = sin6_src->sin6_addr;
173 /* bidirectional configured tunnel mode */
174 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
175 ip6->ip6_dst = sin6_dst->sin6_addr;
176 else {
177 m_freem(m);
178 return ENETUNREACH;
179 }
180 if (ifp->if_flags & IFF_LINK1)
181 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
182 else
183 ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
184 ip6->ip6_flow &= ~ntohl(0xff00000);
185 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
186
187 if (dst->sin6_family != sin6_dst->sin6_family ||
188 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
189 /* cache route doesn't match */
190 bzero(dst, sizeof(*dst));
191 dst->sin6_family = sin6_dst->sin6_family;
192 dst->sin6_len = sizeof(struct sockaddr_in6);
193 dst->sin6_addr = sin6_dst->sin6_addr;
194 if (ro->ro_rt != NULL) {
195 RTFREE(ro->ro_rt);
196 ro->ro_rt = NULL;
197 }
198 #if 0
199 sc->gif_if.if_mtu = GIF_MTU;
200 #endif
201 }
202
203 if (ro->ro_rt == NULL) {
204 rtalloc((struct route *)ro);
205 if (ro->ro_rt == NULL) {
206 m_freem(m);
207 return ENETUNREACH;
208 }
209
210 /* if it constitutes infinite encapsulation, punt. */
211 if (ro->ro_rt->rt_ifp == ifp) {
212 m_freem(m);
213 return ENETUNREACH; /*XXX*/
214 }
215 #if 0
216 ifp->if_mtu = ro->ro_rt->rt_ifp->if_mtu -
217 sizeof(struct ip6_hdr);
218 #endif
219 }
220
221 #ifdef IPV6_MINMTU
222 /*
223 * force fragmentation to minimum MTU, to avoid path MTU discovery.
224 * it is too painful to ask for resend of inner packet, to achieve
225 * path MTU discovery for encapsulated packets.
226 */
227 return (ip6_output(m, 0, ro, IPV6_MINMTU, 0, NULL, NULL));
228 #else
229 return (ip6_output(m, 0, ro, 0, 0, NULL, NULL));
230 #endif
231 }
232
233 int
in6_gif_input(struct mbuf ** mp,int * offp,int proto)234 in6_gif_input(struct mbuf **mp, int *offp, int proto)
235 {
236 struct mbuf *m = *mp;
237 struct ifnet *gifp = NULL;
238 struct ip6_hdr *ip6;
239 int af = 0;
240 u_int32_t otos;
241
242 ip6 = mtod(m, struct ip6_hdr *);
243
244 gifp = (struct ifnet *)encap_getarg(m);
245
246 if (gifp == NULL || !(gifp->if_flags & IFF_UP)) {
247 m_freem(m);
248 ip6stat.ip6s_nogif++;
249 return IPPROTO_DONE;
250 }
251
252 otos = ip6->ip6_flow;
253 m_adj(m, *offp);
254
255 switch (proto) {
256 #ifdef INET
257 case IPPROTO_IPV4:
258 {
259 struct ip *ip;
260 u_int8_t otos8;
261 af = AF_INET;
262 otos8 = (ntohl(otos) >> 20) & 0xff;
263 if (m->m_len < sizeof(*ip)) {
264 m = m_pullup(m, sizeof(*ip));
265 if (!m)
266 return IPPROTO_DONE;
267 }
268 ip = mtod(m, struct ip *);
269 if (gifp->if_flags & IFF_LINK1)
270 ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
271 else
272 ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
273 break;
274 }
275 #endif /* INET */
276 #ifdef INET6
277 case IPPROTO_IPV6:
278 {
279 struct ip6_hdr *ip6;
280 af = AF_INET6;
281 if (m->m_len < sizeof(*ip6)) {
282 m = m_pullup(m, sizeof(*ip6));
283 if (!m)
284 return IPPROTO_DONE;
285 }
286 ip6 = mtod(m, struct ip6_hdr *);
287 if (gifp->if_flags & IFF_LINK1)
288 ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
289 else
290 ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
291 break;
292 }
293 #endif
294 default:
295 ip6stat.ip6s_nogif++;
296 m_freem(m);
297 return IPPROTO_DONE;
298 }
299
300 gif_input(m, af, gifp);
301 return IPPROTO_DONE;
302 }
303
304 /*
305 * validate outer address.
306 */
307 static int
gif_validate6(const struct ip6_hdr * ip6,struct gif_softc * sc,struct ifnet * ifp)308 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
309 struct ifnet *ifp)
310 {
311 struct sockaddr_in6 *src, *dst;
312
313 src = (struct sockaddr_in6 *)sc->gif_psrc;
314 dst = (struct sockaddr_in6 *)sc->gif_pdst;
315
316 /*
317 * Check for address match. Note that the check is for an incoming
318 * packet. We should compare the *source* address in our configuration
319 * and the *destination* address of the packet, and vice versa.
320 */
321 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
322 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
323 return 0;
324
325 /* martian filters on outer source - done in ip6_input */
326
327 /* ingress filters on outer source */
328 if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp) {
329 struct sockaddr_in6 sin6;
330 struct rtentry *rt;
331
332 bzero(&sin6, sizeof(sin6));
333 sin6.sin6_family = AF_INET6;
334 sin6.sin6_len = sizeof(struct sockaddr_in6);
335 sin6.sin6_addr = ip6->ip6_src;
336 sin6.sin6_scope_id = 0; /* XXX */
337
338 rt = rtpurelookup((struct sockaddr *)&sin6);
339 if (rt != NULL)
340 --rt->rt_refcnt;
341 if (rt == NULL || rt->rt_ifp != ifp) {
342 #if 0
343 log(LOG_WARNING, "%s: packet from %s dropped "
344 "due to ingress filter\n", if_name(&sc->gif_if),
345 ip6_sprintf(&sin6.sin6_addr));
346 #endif
347 return 0;
348 }
349 }
350
351 return 128 * 2;
352 }
353
354 /*
355 * we know that we are in IFF_UP, outer address available, and outer family
356 * matched the physical addr family. see gif_encapcheck().
357 * sanity check for arg should have been done in the caller.
358 */
359 int
gif_encapcheck6(const struct mbuf * m,int off,int proto,void * arg)360 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
361 {
362 struct ip6_hdr ip6;
363 struct gif_softc *sc;
364 struct ifnet *ifp;
365
366 /* sanity check done in caller */
367 sc = (struct gif_softc *)arg;
368
369 m_copydata(m, 0, sizeof(ip6), &ip6);
370 ifp = (m->m_flags & M_PKTHDR) ? m->m_pkthdr.rcvif : NULL;
371
372 return gif_validate6(&ip6, sc, ifp);
373 }
374
375 int
in6_gif_attach(struct gif_softc * sc)376 in6_gif_attach(struct gif_softc *sc)
377 {
378 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
379 &in6_gif_protosw, sc);
380 if (sc->encap_cookie6 == NULL)
381 return EEXIST;
382 return 0;
383 }
384
385 int
in6_gif_detach(struct gif_softc * sc)386 in6_gif_detach(struct gif_softc *sc)
387 {
388 int error;
389
390 error = encap_detach(sc->encap_cookie6);
391 if (error == 0)
392 sc->encap_cookie6 = NULL;
393 return error;
394 }
395
396 #endif /* INET6 */
397