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: releng/10.1/sys/netinet6/in6_gif.c 273188 2014-10-16 22:00:24Z hrs $");
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/kernel.h>
45 #include <sys/queue.h>
46 #include <sys/syslog.h>
47 #include <sys/sysctl.h>
48 #include <sys/protosw.h>
49 #include <sys/malloc.h>
50
51 #include <net/if.h>
52 #include <net/route.h>
53
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 #ifdef INET
57 #include <netinet/ip.h>
58 #endif
59 #include <netinet/ip_encap.h>
60 #ifdef INET6
61 #include <netinet/ip6.h>
62 #include <netinet6/ip6_var.h>
63 #include <netinet6/in6_gif.h>
64 #include <netinet6/in6_var.h>
65 #endif
66 #include <netinet6/ip6protosw.h>
67 #include <netinet/ip_ecn.h>
68 #ifdef INET6
69 #include <netinet6/ip6_ecn.h>
70 #endif
71
72 #include <net/if_gif.h>
73
74 VNET_DEFINE(int, ip6_gif_hlim) = GIF_HLIM;
75 #define V_ip6_gif_hlim VNET(ip6_gif_hlim)
76
77 SYSCTL_DECL(_net_inet6_ip6);
78 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_RW,
79 &VNET_NAME(ip6_gif_hlim), 0, "");
80
81 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
82 struct ifnet *);
83
84 extern struct domain inet6domain;
85 struct ip6protosw in6_gif_protosw = {
86 .pr_type = SOCK_RAW,
87 .pr_domain = &inet6domain,
88 .pr_protocol = 0, /* IPPROTO_IPV[46] */
89 .pr_flags = PR_ATOMIC|PR_ADDR,
90 .pr_input = in6_gif_input,
91 .pr_output = rip6_output,
92 .pr_ctloutput = rip6_ctloutput,
93 .pr_usrreqs = &rip6_usrreqs
94 };
95
96 int
97 in6_gif_output(struct ifnet *ifp,
98 int family, /* family of the packet to be encapsulate */
99 struct mbuf *m)
100 {
101 struct gif_softc *sc = ifp->if_softc;
102 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
103 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
104 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
105 struct ip6_hdr *ip6;
106 struct etherip_header eiphdr;
107 int error, len, proto;
108 u_int8_t itos, otos;
109
110 GIF_LOCK_ASSERT(sc);
111
112 if (sin6_src == NULL || sin6_dst == NULL ||
113 sin6_src->sin6_family != AF_INET6 ||
114 sin6_dst->sin6_family != AF_INET6) {
115 m_freem(m);
116 return EAFNOSUPPORT;
117 }
118
119 switch (family) {
120 #ifdef INET
121 case AF_INET:
122 {
123 struct ip *ip;
124
125 proto = IPPROTO_IPV4;
126 if (m->m_len < sizeof(*ip)) {
127 m = m_pullup(m, sizeof(*ip));
128 if (!m)
129 return ENOBUFS;
130 }
131 ip = mtod(m, struct ip *);
132 itos = ip->ip_tos;
133 break;
134 }
135 #endif
136 #ifdef INET6
137 case AF_INET6:
138 {
139 struct ip6_hdr *ip6;
140 proto = IPPROTO_IPV6;
141 if (m->m_len < sizeof(*ip6)) {
142 m = m_pullup(m, sizeof(*ip6));
143 if (!m)
144 return ENOBUFS;
145 }
146 ip6 = mtod(m, struct ip6_hdr *);
147 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
148 break;
149 }
150 #endif
151 case AF_LINK:
152 proto = IPPROTO_ETHERIP;
153
154 /*
155 * GIF_SEND_REVETHIP (disabled by default) intentionally
156 * sends an EtherIP packet with revered version field in
157 * the header. This is a knob for backward compatibility
158 * with FreeBSD 7.2R or prior.
159 */
160 if ((sc->gif_options & GIF_SEND_REVETHIP)) {
161 eiphdr.eip_ver = 0;
162 eiphdr.eip_resvl = ETHERIP_VERSION;
163 eiphdr.eip_resvh = 0;
164 } else {
165 eiphdr.eip_ver = ETHERIP_VERSION;
166 eiphdr.eip_resvl = 0;
167 eiphdr.eip_resvh = 0;
168 }
169 /* prepend Ethernet-in-IP header */
170 M_PREPEND(m, sizeof(struct etherip_header), M_NOWAIT);
171 if (m && m->m_len < sizeof(struct etherip_header))
172 m = m_pullup(m, sizeof(struct etherip_header));
173 if (m == NULL)
174 return ENOBUFS;
175 bcopy(&eiphdr, mtod(m, struct etherip_header *),
176 sizeof(struct etherip_header));
177 itos = 0;
178 break;
179
180 default:
181 #ifdef DEBUG
182 printf("in6_gif_output: warning: unknown family %d passed\n",
183 family);
184 #endif
185 m_freem(m);
186 return EAFNOSUPPORT;
187 }
188
189 /* prepend new IP header */
190 len = sizeof(struct ip6_hdr);
191 #ifndef __NO_STRICT_ALIGNMENT
192 if (family == AF_LINK)
193 len += ETHERIP_ALIGN;
194 #endif
195 M_PREPEND(m, len, M_NOWAIT);
196 if (m != NULL && m->m_len < len)
197 m = m_pullup(m, len);
198 if (m == NULL) {
199 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
200 return ENOBUFS;
201 }
202 #ifndef __NO_STRICT_ALIGNMENT
203 if (family == AF_LINK) {
204 len = mtod(m, vm_offset_t) & 3;
205 KASSERT(len == 0 || len == ETHERIP_ALIGN,
206 ("in6_gif_output: unexpected misalignment"));
207 m->m_data += len;
208 m->m_len -= ETHERIP_ALIGN;
209 }
210 #endif
211
212 ip6 = mtod(m, struct ip6_hdr *);
213 ip6->ip6_flow = 0;
214 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
215 ip6->ip6_vfc |= IPV6_VERSION;
216 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
217 ip6->ip6_nxt = proto;
218 ip6->ip6_hlim = V_ip6_gif_hlim;
219 ip6->ip6_src = sin6_src->sin6_addr;
220 /* bidirectional configured tunnel mode */
221 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
222 ip6->ip6_dst = sin6_dst->sin6_addr;
223 else {
224 m_freem(m);
225 return ENETUNREACH;
226 }
227 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
228 &otos, &itos);
229 ip6->ip6_flow &= ~htonl(0xff << 20);
230 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
231
232 M_SETFIB(m, sc->gif_fibnum);
233
234 if (dst->sin6_family != sin6_dst->sin6_family ||
235 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
236 /* cache route doesn't match */
237 bzero(dst, sizeof(*dst));
238 dst->sin6_family = sin6_dst->sin6_family;
239 dst->sin6_len = sizeof(struct sockaddr_in6);
240 dst->sin6_addr = sin6_dst->sin6_addr;
241 if (sc->gif_ro6.ro_rt) {
242 RTFREE(sc->gif_ro6.ro_rt);
243 sc->gif_ro6.ro_rt = NULL;
244 }
245 #if 0
246 GIF2IFP(sc)->if_mtu = GIF_MTU;
247 #endif
248 }
249
250 if (sc->gif_ro6.ro_rt == NULL) {
251 in6_rtalloc(&sc->gif_ro6, sc->gif_fibnum);
252 if (sc->gif_ro6.ro_rt == NULL) {
253 m_freem(m);
254 return ENETUNREACH;
255 }
256
257 /* if it constitutes infinite encapsulation, punt. */
258 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
259 m_freem(m);
260 return ENETUNREACH; /*XXX*/
261 }
262 #if 0
263 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
264 - sizeof(struct ip6_hdr);
265 #endif
266 }
267
268 m->m_flags &= ~(M_BCAST|M_MCAST);
269 #ifdef IPV6_MINMTU
270 /*
271 * force fragmentation to minimum MTU, to avoid path MTU discovery.
272 * it is too painful to ask for resend of inner packet, to achieve
273 * path MTU discovery for encapsulated packets.
274 */
275 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
276 #else
277 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
278 #endif
279
280 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
281 sc->gif_ro6.ro_rt != NULL) {
282 RTFREE(sc->gif_ro6.ro_rt);
283 sc->gif_ro6.ro_rt = NULL;
284 }
285
286 return (error);
287 }
288
289 int
290 in6_gif_input(struct mbuf **mp, int *offp, int proto)
291 {
292 struct mbuf *m = *mp;
293 struct ifnet *gifp = NULL;
294 struct gif_softc *sc;
295 struct ip6_hdr *ip6;
296 int af = 0;
297 u_int32_t otos;
298
299 ip6 = mtod(m, struct ip6_hdr *);
300
301 sc = (struct gif_softc *)encap_getarg(m);
302 if (sc == NULL) {
303 m_freem(m);
304 IP6STAT_INC(ip6s_nogif);
305 return IPPROTO_DONE;
306 }
307
308 gifp = GIF2IFP(sc);
309 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
310 m_freem(m);
311 IP6STAT_INC(ip6s_nogif);
312 return IPPROTO_DONE;
313 }
314
315 otos = ip6->ip6_flow;
316 m_adj(m, *offp);
317
318 switch (proto) {
319 #ifdef INET
320 case IPPROTO_IPV4:
321 {
322 struct ip *ip;
323 u_int8_t otos8;
324 af = AF_INET;
325 otos8 = (ntohl(otos) >> 20) & 0xff;
326 if (m->m_len < sizeof(*ip)) {
327 m = m_pullup(m, sizeof(*ip));
328 if (!m)
329 return IPPROTO_DONE;
330 }
331 ip = mtod(m, struct ip *);
332 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
333 ECN_ALLOWED : ECN_NOCARE,
334 &otos8, &ip->ip_tos) == 0) {
335 m_freem(m);
336 return IPPROTO_DONE;
337 }
338 break;
339 }
340 #endif /* INET */
341 #ifdef INET6
342 case IPPROTO_IPV6:
343 {
344 struct ip6_hdr *ip6;
345 af = AF_INET6;
346 if (m->m_len < sizeof(*ip6)) {
347 m = m_pullup(m, sizeof(*ip6));
348 if (!m)
349 return IPPROTO_DONE;
350 }
351 ip6 = mtod(m, struct ip6_hdr *);
352 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ?
353 ECN_ALLOWED : ECN_NOCARE,
354 &otos, &ip6->ip6_flow) == 0) {
355 m_freem(m);
356 return IPPROTO_DONE;
357 }
358 break;
359 }
360 #endif
361 case IPPROTO_ETHERIP:
362 af = AF_LINK;
363 break;
364
365 default:
366 IP6STAT_INC(ip6s_nogif);
367 m_freem(m);
368 return IPPROTO_DONE;
369 }
370
371 gif_input(m, af, gifp);
372 return IPPROTO_DONE;
373 }
374
375 /*
376 * validate outer address.
377 */
378 static int
379 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
380 struct ifnet *ifp)
381 {
382 struct sockaddr_in6 *src, *dst;
383
384 src = (struct sockaddr_in6 *)sc->gif_psrc;
385 dst = (struct sockaddr_in6 *)sc->gif_pdst;
386
387 /*
388 * Check for address match. Note that the check is for an incoming
389 * packet. We should compare the *source* address in our configuration
390 * and the *destination* address of the packet, and vice versa.
391 */
392 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
393 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
394 return 0;
395
396 /* martian filters on outer source - done in ip6_input */
397
398 /* ingress filters on outer source */
399 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
400 struct sockaddr_in6 sin6;
401 struct rtentry *rt;
402
403 bzero(&sin6, sizeof(sin6));
404 sin6.sin6_family = AF_INET6;
405 sin6.sin6_len = sizeof(struct sockaddr_in6);
406 sin6.sin6_addr = ip6->ip6_src;
407 sin6.sin6_scope_id = 0; /* XXX */
408
409 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL,
410 sc->gif_fibnum);
411 if (!rt || rt->rt_ifp != ifp) {
412 #if 0
413 char ip6buf[INET6_ADDRSTRLEN];
414 log(LOG_WARNING, "%s: packet from %s dropped "
415 "due to ingress filter\n", if_name(GIF2IFP(sc)),
416 ip6_sprintf(ip6buf, &sin6.sin6_addr));
417 #endif
418 if (rt)
419 RTFREE_LOCKED(rt);
420 return 0;
421 }
422 RTFREE_LOCKED(rt);
423 }
424
425 return 128 * 2;
426 }
427
428 /*
429 * we know that we are in IFF_UP, outer address available, and outer family
430 * matched the physical addr family. see gif_encapcheck().
431 * sanity check for arg should have been done in the caller.
432 */
433 int
434 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
435 {
436 struct ip6_hdr ip6;
437 struct gif_softc *sc;
438 struct ifnet *ifp;
439
440 /* sanity check done in caller */
441 sc = (struct gif_softc *)arg;
442
443 /* LINTED const cast */
444 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
445 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
446
447 return gif_validate6(&ip6, sc, ifp);
448 }
449
450 int
451 in6_gif_attach(struct gif_softc *sc)
452 {
453 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
454 (void *)&in6_gif_protosw, sc);
455 if (sc->encap_cookie6 == NULL)
456 return EEXIST;
457 return 0;
458 }
459
460 int
461 in6_gif_detach(struct gif_softc *sc)
462 {
463 int error;
464
465 error = encap_detach(sc->encap_cookie6);
466 if (error == 0)
467 sc->encap_cookie6 = NULL;
468 return error;
469 }
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