1/* $NetBSD: in6_gif.c,v 1.79 2016/07/15 07:40:09 ozaki-r Exp $ */
2/* $KAME: in6_gif.c,v 1.62 2001/07/29 04:27:25 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 <sys/cdefs.h>
34__KERNEL_RCSID(0, "$NetBSD: in6_gif.c,v 1.79 2016/07/15 07:40:09 ozaki-r Exp $");
35
36#ifdef _KERNEL_OPT
37#include "opt_inet.h"
38#endif
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/socket.h>
43#include <sys/sockio.h>
44#include <sys/mbuf.h>
45#include <sys/errno.h>
46#include <sys/ioctl.h>
47#include <sys/queue.h>
48#include <sys/syslog.h>
49#include <sys/kernel.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/ip6_private.h>
64#include <netinet6/in6_gif.h>
65#include <netinet6/in6_var.h>
66#endif
67#include <netinet6/ip6protosw.h> /* for struct ip6ctlparam */
68#include <netinet/ip_ecn.h>
69
70#include <net/if_gif.h>
71
72#include <net/net_osdep.h>
73
74static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
75 struct ifnet *);
76
77int ip6_gif_hlim = GIF_HLIM;
78
79static const struct encapsw in6_gif_encapsw;
80
81/*
82 * family - family of the packet to be encapsulate.
83 */
84
85int
86in6_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
87{
88 struct rtentry *rt;
89 struct gif_softc *sc = ifp->if_softc;
90 struct sockaddr_in6 *sin6_src = satosin6(sc->gif_psrc);
91 struct sockaddr_in6 *sin6_dst = satosin6(sc->gif_pdst);
92 struct ip6_hdr *ip6;
93 int proto, error;
94 u_int8_t itos, otos;
95 union {
96 struct sockaddr dst;
97 struct sockaddr_in6 dst6;
98 } u;
99
100 if (sin6_src == NULL || sin6_dst == NULL ||
101 sin6_src->sin6_family != AF_INET6 ||
102 sin6_dst->sin6_family != AF_INET6) {
103 m_freem(m);
104 return EAFNOSUPPORT;
105 }
106
107 switch (family) {
108#ifdef INET
109 case AF_INET:
110 {
111 struct ip *ip;
112
113 proto = IPPROTO_IPV4;
114 if (m->m_len < sizeof(*ip)) {
115 m = m_pullup(m, sizeof(*ip));
116 if (!m)
117 return ENOBUFS;
118 }
119 ip = mtod(m, struct ip *);
120 itos = ip->ip_tos;
121 break;
122 }
123#endif
124#ifdef INET6
125 case AF_INET6:
126 {
127 proto = IPPROTO_IPV6;
128 if (m->m_len < sizeof(*ip6)) {
129 m = m_pullup(m, sizeof(*ip6));
130 if (!m)
131 return ENOBUFS;
132 }
133 ip6 = mtod(m, struct ip6_hdr *);
134 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
135 break;
136 }
137#endif
138 default:
139#ifdef DEBUG
140 printf("in6_gif_output: warning: unknown family %d passed\n",
141 family);
142#endif
143 m_freem(m);
144 return EAFNOSUPPORT;
145 }
146
147 /* prepend new IP header */
148 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
149 if (m && m->m_len < sizeof(struct ip6_hdr))
150 m = m_pullup(m, sizeof(struct ip6_hdr));
151 if (m == NULL)
152 return ENOBUFS;
153
154 ip6 = mtod(m, struct ip6_hdr *);
155 ip6->ip6_flow = 0;
156 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
157 ip6->ip6_vfc |= IPV6_VERSION;
158#if 0 /* ip6->ip6_plen will be filled by ip6_output */
159 ip6->ip6_plen = htons((u_int16_t)m->m_pkthdr.len);
160#endif
161 ip6->ip6_nxt = proto;
162 ip6->ip6_hlim = ip6_gif_hlim;
163 ip6->ip6_src = sin6_src->sin6_addr;
164 /* bidirectional configured tunnel mode */
165 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
166 ip6->ip6_dst = sin6_dst->sin6_addr;
167 else {
168 m_freem(m);
169 return ENETUNREACH;
170 }
171 if (ifp->if_flags & IFF_LINK1)
172 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
173 else
174 ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
175 ip6->ip6_flow &= ~ntohl(0xff00000);
176 ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
177
178 sockaddr_in6_init(&u.dst6, &sin6_dst->sin6_addr, 0, 0, 0);
179 if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) {
180 m_freem(m);
181 return ENETUNREACH;
182 }
183
184 /* If the route constitutes infinite encapsulation, punt. */
185 if (rt->rt_ifp == ifp) {
186 rtcache_free(&sc->gif_ro);
187 m_freem(m);
188 return ENETUNREACH; /* XXX */
189 }
190
191#ifdef IPV6_MINMTU
192 /*
193 * force fragmentation to minimum MTU, to avoid path MTU discovery.
194 * it is too painful to ask for resend of inner packet, to achieve
195 * path MTU discovery for encapsulated packets.
196 */
197 error = ip6_output(m, 0, &sc->gif_ro, IPV6_MINMTU, NULL, NULL, NULL);
198#else
199 error = ip6_output(m, 0, &sc->gif_ro, 0, NULL, NULL, NULL);
200#endif
201
202 return (error);
203}
204
205int
206in6_gif_input(struct mbuf **mp, int *offp, int proto)
207{
208 struct mbuf *m = *mp;
209 struct ifnet *gifp = NULL;
210 struct ip6_hdr *ip6;
211 int af = 0;
212 u_int32_t otos;
213
214 ip6 = mtod(m, struct ip6_hdr *);
215
216 gifp = (struct ifnet *)encap_getarg(m);
217
218 if (gifp == NULL || (gifp->if_flags & (IFF_UP|IFF_RUNNING))
219 != (IFF_UP|IFF_RUNNING)) {
220 m_freem(m);
221 IP6_STATINC(IP6_STAT_NOGIF);
222 return IPPROTO_DONE;
223 }
224#ifndef GIF_ENCAPCHECK
225 struct gif_softc *sc = (struct gif_softc *)gifp->if_softc;
226 /* other CPU do delete_tunnel */
227 if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
228 m_freem(m);
229 IP6_STATINC(IP6_STAT_NOGIF);
230 return IPPROTO_DONE;
231 }
232
233 struct psref psref;
234 struct ifnet *rcvif = m_get_rcvif_psref(m, &psref);
235 if (rcvif == NULL || !gif_validate6(ip6, sc, rcvif)) {
236 m_put_rcvif_psref(rcvif, &psref);
237 m_freem(m);
238 IP6_STATINC(IP6_STAT_NOGIF);
239 return IPPROTO_DONE;
240 }
241 m_put_rcvif_psref(rcvif, &psref);
242#endif
243
244 otos = ip6->ip6_flow;
245 m_adj(m, *offp);
246
247 switch (proto) {
248#ifdef INET
249 case IPPROTO_IPV4:
250 {
251 struct ip *ip;
252 u_int8_t otos8;
253 af = AF_INET;
254 otos8 = (ntohl(otos) >> 20) & 0xff;
255 if (m->m_len < sizeof(*ip)) {
256 m = m_pullup(m, sizeof(*ip));
257 if (!m)
258 return IPPROTO_DONE;
259 }
260 ip = mtod(m, struct ip *);
261 if (gifp->if_flags & IFF_LINK1)
262 ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
263 else
264 ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
265 break;
266 }
267#endif /* INET */
268#ifdef INET6
269 case IPPROTO_IPV6:
270 {
271 struct ip6_hdr *ip6x;
272 af = AF_INET6;
273 if (m->m_len < sizeof(*ip6x)) {
274 m = m_pullup(m, sizeof(*ip6x));
275 if (!m)
276 return IPPROTO_DONE;
277 }
278 ip6x = mtod(m, struct ip6_hdr *);
279 if (gifp->if_flags & IFF_LINK1)
280 ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow);
281 else
282 ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow);
283 break;
284 }
285#endif
286 default:
287 IP6_STATINC(IP6_STAT_NOGIF);
288 m_freem(m);
289 return IPPROTO_DONE;
290 }
291
292 gif_input(m, af, gifp);
293 return IPPROTO_DONE;
294}
295
296/*
297 * validate outer address.
298 */
299static int
300gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
301 struct ifnet *ifp)
302{
303 const struct sockaddr_in6 *src, *dst;
304
305 src = satosin6(sc->gif_psrc);
306 dst = satosin6(sc->gif_pdst);
307
308 /* check for address match */
309 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
310 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
311 return 0;
312
313 /* martian filters on outer source - done in ip6_input */
314
315 /* ingress filters on outer source */
316 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
317 union {
318 struct sockaddr sa;
319 struct sockaddr_in6 sin6;
320 } u;
321 struct rtentry *rt;
322
323 /* XXX scopeid */
324 sockaddr_in6_init(&u.sin6, &ip6->ip6_src, 0, 0, 0);
325 rt = rtalloc1(&u.sa, 0);
326 if (rt == NULL || rt->rt_ifp != ifp) {
327#if 0
328 log(LOG_WARNING, "%s: packet from %s dropped "
329 "due to ingress filter\n", if_name(&sc->gif_if),
330 ip6_sprintf(&u.sin6.sin6_addr));
331#endif
332 if (rt != NULL)
333 rtfree(rt);
334 return 0;
335 }
336 rtfree(rt);
337 }
338
339 return 128 * 2;
340}
341
342#ifdef GIF_ENCAPCHECK
343/*
344 * we know that we are in IFF_UP, outer address available, and outer family
345 * matched the physical addr family. see gif_encapcheck().
346 */
347int
348gif_encapcheck6(struct mbuf *m, int off, int proto, void *arg)
349{
350 struct ip6_hdr ip6;
351 struct gif_softc *sc;
352 struct ifnet *ifp = NULL;
353 int r;
354 struct psref psref;
355
356 /* sanity check done in caller */
357 sc = arg;
358
359 m_copydata(m, 0, sizeof(ip6), (void *)&ip6);
360 if ((m->m_flags & M_PKTHDR) != 0)
361 ifp = m_get_rcvif_psref(m, &psref);
362
363 r = gif_validate6(&ip6, sc, ifp);
364
365 m_put_rcvif_psref(ifp, &psref);
366 return r;
367}
368#endif
369
370int
371in6_gif_attach(struct gif_softc *sc)
372{
373#ifndef GIF_ENCAPCHECK
374 struct sockaddr_in6 mask6;
375
376 memset(&mask6, 0, sizeof(mask6));
377 mask6.sin6_len = sizeof(struct sockaddr_in6);
378 mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] =
379 mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;
380
381 if (!sc->gif_psrc || !sc->gif_pdst)
382 return EINVAL;
383 sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc,
384 sin6tosa(&mask6), sc->gif_pdst, sin6tosa(&mask6),
385 (const void *)&in6_gif_encapsw, sc);
386#else
387 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
388 &in6_gif_encapsw, sc);
389#endif
390 if (sc->encap_cookie6 == NULL)
391 return EEXIST;
392 return 0;
393}
394
395int
396in6_gif_detach(struct gif_softc *sc)
397{
398 int error;
399
400 error = in6_gif_pause(sc);
401
402 rtcache_free(&sc->gif_ro);
403
404 return error;
405}
406
407int
408in6_gif_pause(struct gif_softc *sc)
409{
410 int error;
411
412 error = encap_detach(sc->encap_cookie6);
413 if (error == 0)
414 sc->encap_cookie6 = NULL;
415
416 return error;
417}
418
419void *
420in6_gif_ctlinput(int cmd, const struct sockaddr *sa, void *d, void *eparg)
421{
422 struct gif_softc *sc = eparg;
423 struct ip6ctlparam *ip6cp = NULL;
424 struct ip6_hdr *ip6;
425 const struct sockaddr_in6 *dst6;
426
427 if (sa->sa_family != AF_INET6 ||
428 sa->sa_len != sizeof(struct sockaddr_in6))
429 return NULL;
430
431 if ((unsigned)cmd >= PRC_NCMDS)
432 return NULL;
433 if (cmd == PRC_HOSTDEAD)
434 d = NULL;
435 else if (inet6ctlerrmap[cmd] == 0)
436 return NULL;
437
438 /* if the parameter is from icmp6, decode it. */
439 if (d != NULL) {
440 ip6cp = (struct ip6ctlparam *)d;
441 ip6 = ip6cp->ip6c_ip6;
442 } else {
443 ip6 = NULL;
444 }
445
446 if (!ip6)
447 return NULL;
448
449 if ((sc->gif_if.if_flags & IFF_RUNNING) == 0)
450 return NULL;
451 if (sc->gif_psrc->sa_family != AF_INET6)
452 return NULL;
453
454 dst6 = satocsin6(rtcache_getdst(&sc->gif_ro));
455 /* XXX scope */
456 if (dst6 == NULL)
457 ;
458 else if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr))
459 rtcache_free(&sc->gif_ro);
460
461 return NULL;
462}
463
464ENCAP_PR_WRAP_CTLINPUT(in6_gif_ctlinput)
465#define in6_gif_ctlinput in6_gif_ctlinput_wrapper
466
467static const struct encapsw in6_gif_encapsw = {
468 .encapsw6 = {
469 .pr_input = in6_gif_input,
470 .pr_ctlinput = in6_gif_ctlinput,
471 }
472};
473