1/*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/sys/netinet6/in6_gif.c 183550 2008-10-02 15:37:58Z zec $");
34
35#include "opt_inet.h"
36#include "opt_inet6.h"
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/socket.h>
41#include <sys/sockio.h>
42#include <sys/mbuf.h>
43#include <sys/errno.h>
44#include <sys/queue.h>
45#include <sys/syslog.h>
46#include <sys/protosw.h>
47#include <sys/malloc.h>
48#include <sys/vimage.h>
49
50#include <net/if.h>
51#include <net/route.h>
52
53#include <netinet/in.h>
54#include <netinet/in_systm.h>
55#ifdef INET
56#include <netinet/ip.h>
57#endif
58#include <netinet/ip_encap.h>
59#ifdef INET6
60#include <netinet/ip6.h>
61#include <netinet6/ip6_var.h>
62#include <netinet6/in6_gif.h>
63#include <netinet6/in6_var.h>
64#endif
65#include <netinet6/ip6protosw.h>
66#include <netinet/ip_ecn.h>
67#ifdef INET6
68#include <netinet6/ip6_ecn.h>
69#endif
70
71#include <net/if_gif.h>
72
73static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
74 struct ifnet *);
75
76extern struct domain inet6domain;
77struct 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
85int
86in6_gif_output(struct ifnet *ifp,
87 int family, /* family of the packet to be encapsulate */
88 struct mbuf *m)
89{
90 INIT_VNET_GIF(ifp->if_vnet);
91 struct gif_softc *sc = ifp->if_softc;
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 struct etherip_header eiphdr;
97 int proto, error;
98 u_int8_t itos, otos;
99
100 GIF_LOCK_ASSERT(sc);
101
102 if (sin6_src == NULL || sin6_dst == NULL ||
103 sin6_src->sin6_family != AF_INET6 ||
104 sin6_dst->sin6_family != AF_INET6) {
105 m_freem(m);
106 return EAFNOSUPPORT;
107 }
108
109 switch (family) {
110#ifdef INET
111 case AF_INET:
112 {
113 struct ip *ip;
114
115 proto = IPPROTO_IPV4;
116 if (m->m_len < sizeof(*ip)) {
117 m = m_pullup(m, sizeof(*ip));
118 if (!m)
119 return ENOBUFS;
120 }
121 ip = mtod(m, struct ip *);
122 itos = ip->ip_tos;
123 break;
124 }
125#endif
126#ifdef INET6
127 case AF_INET6:
128 {
129 struct ip6_hdr *ip6;
130 proto = IPPROTO_IPV6;
131 if (m->m_len < sizeof(*ip6)) {
132 m = m_pullup(m, sizeof(*ip6));
133 if (!m)
134 return ENOBUFS;
135 }
136 ip6 = mtod(m, struct ip6_hdr *);
137 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
138 break;
139 }
140#endif
141 case AF_LINK:
142 proto = IPPROTO_ETHERIP;
143 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
144 eiphdr.eip_pad = 0;
145 /* prepend Ethernet-in-IP header */
146 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
147 if (m && m->m_len < sizeof(struct etherip_header))
148 m = m_pullup(m, sizeof(struct etherip_header));
149 if (m == NULL)
150 return ENOBUFS;
151 bcopy(&eiphdr, mtod(m, struct etherip_header *),
152 sizeof(struct etherip_header));
153 break;
154
155 default:
156#ifdef 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);
166 if (m && m->m_len < 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 = V_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_ALLOWED : 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 (dst->sin6_family != sin6_dst->sin6_family ||
194 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
195 /* cache route doesn't match */
196 bzero(dst, sizeof(*dst));
197 dst->sin6_family = sin6_dst->sin6_family;
198 dst->sin6_len = sizeof(struct sockaddr_in6);
199 dst->sin6_addr = sin6_dst->sin6_addr;
200 if (sc->gif_ro6.ro_rt) {
201 RTFREE(sc->gif_ro6.ro_rt);
202 sc->gif_ro6.ro_rt = NULL;
203 }
204#if 0
205 GIF2IFP(sc)->if_mtu = GIF_MTU;
206#endif
207 }
208
209 if (sc->gif_ro6.ro_rt == NULL) {
210 rtalloc((struct route *)&sc->gif_ro6);
211 if (sc->gif_ro6.ro_rt == NULL) {
212 m_freem(m);
213 return ENETUNREACH;
214 }
215
216 /* if it constitutes infinite encapsulation, punt. */
217 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
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 }
226
227#ifdef IPV6_MINMTU
228 /*
229 * force fragmentation to minimum MTU, to avoid path MTU discovery.
230 * it is too painful to ask for resend of inner packet, to achieve
231 * path MTU discovery for encapsulated packets.
232 */
233 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
234#else
235 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
236#endif
237
238 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
239 sc->gif_ro6.ro_rt != NULL) {
240 RTFREE(sc->gif_ro6.ro_rt);
241 sc->gif_ro6.ro_rt = NULL;
242 }
243
244 return (error);
245}
246
247int
248in6_gif_input(struct mbuf **mp, int *offp, int proto)
249{
250 INIT_VNET_INET6(curvnet);
251 struct mbuf *m = *mp;
252 struct ifnet *gifp = NULL;
253 struct gif_softc *sc;
254 struct ip6_hdr *ip6;
255 int af = 0;
256 u_int32_t otos;
257
258 ip6 = mtod(m, struct ip6_hdr *);
259
260 sc = (struct gif_softc *)encap_getarg(m);
261 if (sc == NULL) {
262 m_freem(m);
263 V_ip6stat.ip6s_nogif++;
264 return IPPROTO_DONE;
265 }
266
267 gifp = GIF2IFP(sc);
268 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
269 m_freem(m);
270 V_ip6stat.ip6s_nogif++;
271 return IPPROTO_DONE;
272 }
273
274 otos = ip6->ip6_flow;
275 m_adj(m, *offp);
276
277 switch (proto) {
278#ifdef INET
279 case IPPROTO_IPV4:
280 {
281 struct ip *ip;
282 u_int8_t otos8;
283 af = AF_INET;
284 otos8 = (ntohl(otos) >> 20) & 0xff;
285 if (m->m_len < sizeof(*ip)) {
286 m = m_pullup(m, sizeof(*ip));
287 if (!m)
288 return IPPROTO_DONE;
289 }
290 ip = mtod(m, struct ip *);
291 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
292 ECN_ALLOWED : ECN_NOCARE,
293 &otos8, &ip->ip_tos) == 0) {
294 m_freem(m);
295 return IPPROTO_DONE;
296 }
297 break;
298 }
299#endif /* INET */
300#ifdef INET6
301 case IPPROTO_IPV6:
302 {
303 struct ip6_hdr *ip6;
304 af = AF_INET6;
305 if (m->m_len < sizeof(*ip6)) {
306 m = m_pullup(m, sizeof(*ip6));
307 if (!m)
308 return IPPROTO_DONE;
309 }
310 ip6 = mtod(m, struct ip6_hdr *);
311 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
312 ECN_ALLOWED : ECN_NOCARE,
313 &otos, &ip6->ip6_flow) == 0) {
314 m_freem(m);
315 return IPPROTO_DONE;
316 }
317 break;
318 }
319#endif
320 case IPPROTO_ETHERIP:
321 af = AF_LINK;
322 break;
323
324 default:
325 V_ip6stat.ip6s_nogif++;
326 m_freem(m);
327 return IPPROTO_DONE;
328 }
329
330 gif_input(m, af, gifp);
331 return IPPROTO_DONE;
332}
333
334/*
335 * validate outer address.
336 */
337static int
338gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
339 struct ifnet *ifp)
340{
341 struct sockaddr_in6 *src, *dst;
342
343 src = (struct sockaddr_in6 *)sc->gif_psrc;
344 dst = (struct sockaddr_in6 *)sc->gif_pdst;
345
346 /*
347 * Check for address match. Note that the check is for an incoming
348 * packet. We should compare the *source* address in our configuration
349 * and the *destination* address of the packet, and vice versa.
350 */
351 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
352 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
353 return 0;
354
355 /* martian filters on outer source - done in ip6_input */
356
357 /* ingress filters on outer source */
358 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
359 struct sockaddr_in6 sin6;
360 struct rtentry *rt;
361
362 bzero(&sin6, sizeof(sin6));
363 sin6.sin6_family = AF_INET6;
364 sin6.sin6_len = sizeof(struct sockaddr_in6);
365 sin6.sin6_addr = ip6->ip6_src;
366 sin6.sin6_scope_id = 0; /* XXX */
367
368 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
369 if (!rt || rt->rt_ifp != ifp) {
370#if 0
371 char ip6buf[INET6_ADDRSTRLEN];
372 log(LOG_WARNING, "%s: packet from %s dropped "
373 "due to ingress filter\n", if_name(GIF2IFP(sc)),
374 ip6_sprintf(ip6buf, &sin6.sin6_addr));
375#endif
376 if (rt)
377 rtfree(rt);
378 return 0;
379 }
380 rtfree(rt);
381 }
382
383 return 128 * 2;
384}
385
386/*
387 * we know that we are in IFF_UP, outer address available, and outer family
388 * matched the physical addr family. see gif_encapcheck().
389 * sanity check for arg should have been done in the caller.
390 */
391int
392gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
393{
394 struct ip6_hdr ip6;
395 struct gif_softc *sc;
396 struct ifnet *ifp;
397
398 /* sanity check done in caller */
399 sc = (struct gif_softc *)arg;
400
401 /* LINTED const cast */
402 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
403 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
404
405 return gif_validate6(&ip6, sc, ifp);
406}
407
408int
409in6_gif_attach(struct gif_softc *sc)
410{
411 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
412 (void *)&in6_gif_protosw, sc);
413 if (sc->encap_cookie6 == NULL)
414 return EEXIST;
415 return 0;
416}
417
418int
419in6_gif_detach(struct gif_softc *sc)
420{
421 int error;
422
423 error = encap_detach(sc->encap_cookie6);
424 if (error == 0)
425 sc->encap_cookie6 = NULL;
426 return error;
427}