1 /* $FreeBSD: releng/6.0/sys/netinet6/ip6_input.c 151159 2005-10-09 05:21:18Z ume $ */
2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei 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 /*-
34 * Copyright (c) 1982, 1986, 1988, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 4. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
62 */
63
64 #include "opt_ip6fw.h"
65 #include "opt_inet.h"
66 #include "opt_inet6.h"
67 #include "opt_ipsec.h"
68
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/malloc.h>
72 #include <sys/mbuf.h>
73 #include <sys/proc.h>
74 #include <sys/domain.h>
75 #include <sys/protosw.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/errno.h>
79 #include <sys/time.h>
80 #include <sys/kernel.h>
81 #include <sys/syslog.h>
82
83 #include <net/if.h>
84 #include <net/if_types.h>
85 #include <net/if_dl.h>
86 #include <net/route.h>
87 #include <net/netisr.h>
88 #include <net/pfil.h>
89
90 #include <netinet/in.h>
91 #include <netinet/in_systm.h>
92 #ifdef INET
93 #include <netinet/ip.h>
94 #include <netinet/ip_icmp.h>
95 #endif /* INET */
96 #include <netinet/ip6.h>
97 #include <netinet6/in6_var.h>
98 #include <netinet6/ip6_var.h>
99 #include <netinet/in_pcb.h>
100 #include <netinet/icmp6.h>
101 #include <netinet6/scope6_var.h>
102 #include <netinet6/in6_ifattach.h>
103 #include <netinet6/nd6.h>
104
105 #ifdef IPSEC
106 #include <netinet6/ipsec.h>
107 #ifdef INET6
108 #include <netinet6/ipsec6.h>
109 #endif
110 #endif
111
112 #ifdef FAST_IPSEC
113 #include <netipsec/ipsec.h>
114 #include <netipsec/ipsec6.h>
115 #define IPSEC
116 #endif /* FAST_IPSEC */
117
118 #include <netinet6/ip6_fw.h>
119
120 #include <netinet6/ip6protosw.h>
121
122 #include <net/net_osdep.h>
123
124 extern struct domain inet6domain;
125
126 u_char ip6_protox[IPPROTO_MAX];
127 static struct ifqueue ip6intrq;
128 static int ip6qmaxlen = IFQ_MAXLEN;
129 struct in6_ifaddr *in6_ifaddr;
130
131 extern struct callout in6_tmpaddrtimer_ch;
132
133 int ip6_forward_srcrt; /* XXX */
134 int ip6_sourcecheck; /* XXX */
135 int ip6_sourcecheck_interval; /* XXX */
136
137 int ip6_ours_check_algorithm;
138
139 struct pfil_head inet6_pfil_hook;
140
141 /* firewall hooks */
142 ip6_fw_chk_t *ip6_fw_chk_ptr;
143 ip6_fw_ctl_t *ip6_fw_ctl_ptr;
144 int ip6_fw_enable = 1;
145
146 struct ip6stat ip6stat;
147
148 static void ip6_init2 __P((void *));
149 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *));
150 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *));
151 #ifdef PULLDOWN_TEST
152 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int));
153 #endif
154
155 /*
156 * IP6 initialization: fill in IP6 protocol switch table.
157 * All protocols not implemented in kernel go to raw IP6 protocol handler.
158 */
159 void
160 ip6_init()
161 {
162 struct ip6protosw *pr;
163 int i;
164
165 #ifdef DIAGNOSTIC
166 if (sizeof(struct protosw) != sizeof(struct ip6protosw))
167 panic("sizeof(protosw) != sizeof(ip6protosw)");
168 #endif
169 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
170 if (pr == 0)
171 panic("ip6_init");
172
173 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
174 for (i = 0; i < IPPROTO_MAX; i++)
175 ip6_protox[i] = pr - inet6sw;
176 /*
177 * Cycle through IP protocols and put them into the appropriate place
178 * in ip6_protox[].
179 */
180 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
181 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
182 if (pr->pr_domain->dom_family == PF_INET6 &&
183 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
184 /* Be careful to only index valid IP protocols. */
185 if (pr->pr_protocol < IPPROTO_MAX)
186 ip6_protox[pr->pr_protocol] = pr - inet6sw;
187 }
188
189 /* Initialize packet filter hooks. */
190 inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
191 inet6_pfil_hook.ph_af = AF_INET6;
192 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0)
193 printf("%s: WARNING: unable to register pfil hook, "
194 "error %d\n", __func__, i);
195
196 ip6intrq.ifq_maxlen = ip6qmaxlen;
197 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF);
198 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0);
199 scope6_init();
200 addrsel_policy_init();
201 nd6_init();
202 frag6_init();
203 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
204 }
205
206 static void
207 ip6_init2(dummy)
208 void *dummy;
209 {
210
211 /* nd6_timer_init */
212 callout_init(&nd6_timer_ch, 0);
213 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
214
215 /* timer for regeneranation of temporary addresses randomize ID */
216 callout_init(&in6_tmpaddrtimer_ch, 0);
217 callout_reset(&in6_tmpaddrtimer_ch,
218 (ip6_temp_preferred_lifetime - ip6_desync_factor -
219 ip6_temp_regen_advance) * hz,
220 in6_tmpaddrtimer, NULL);
221 }
222
223 /* cheat */
224 /* This must be after route_init(), which is now SI_ORDER_THIRD */
225 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
226
227 extern struct route_in6 ip6_forward_rt;
228
229 void
230 ip6_input(m)
231 struct mbuf *m;
232 {
233 struct ip6_hdr *ip6;
234 int off = sizeof(struct ip6_hdr), nest;
235 u_int32_t plen;
236 u_int32_t rtalert = ~0;
237 int nxt, ours = 0;
238 struct ifnet *deliverifp = NULL;
239 struct sockaddr_in6 sa6;
240 u_int32_t srczone, dstzone;
241 struct in6_addr odst;
242 int srcrt = 0;
243
244 GIANT_REQUIRED; /* XXX for now */
245 #ifdef IPSEC
246 /*
247 * should the inner packet be considered authentic?
248 * see comment in ah4_input().
249 */
250 if (m) {
251 m->m_flags &= ~M_AUTHIPHDR;
252 m->m_flags &= ~M_AUTHIPDGM;
253 }
254 #endif
255
256 /*
257 * make sure we don't have onion peering information into m_tag.
258 */
259 ip6_delaux(m);
260
261 /*
262 * mbuf statistics
263 */
264 if (m->m_flags & M_EXT) {
265 if (m->m_next)
266 ip6stat.ip6s_mext2m++;
267 else
268 ip6stat.ip6s_mext1++;
269 } else {
270 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0]))
271 if (m->m_next) {
272 if (m->m_flags & M_LOOP) {
273 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */
274 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
275 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
276 else
277 ip6stat.ip6s_m2m[0]++;
278 } else
279 ip6stat.ip6s_m1++;
280 #undef M2MMAX
281 }
282
283 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
284 ip6stat.ip6s_total++;
285
286 #ifndef PULLDOWN_TEST
287 /*
288 * L2 bridge code and some other code can return mbuf chain
289 * that does not conform to KAME requirement. too bad.
290 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
291 */
292 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
293 struct mbuf *n;
294
295 MGETHDR(n, M_DONTWAIT, MT_HEADER);
296 if (n)
297 M_MOVE_PKTHDR(n, m);
298 if (n && n->m_pkthdr.len > MHLEN) {
299 MCLGET(n, M_DONTWAIT);
300 if ((n->m_flags & M_EXT) == 0) {
301 m_freem(n);
302 n = NULL;
303 }
304 }
305 if (n == NULL) {
306 m_freem(m);
307 return; /* ENOBUFS */
308 }
309
310 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
311 n->m_len = n->m_pkthdr.len;
312 m_freem(m);
313 m = n;
314 }
315 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
316 #endif
317
318 if (m->m_len < sizeof(struct ip6_hdr)) {
319 struct ifnet *inifp;
320 inifp = m->m_pkthdr.rcvif;
321 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
322 ip6stat.ip6s_toosmall++;
323 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
324 return;
325 }
326 }
327
328 ip6 = mtod(m, struct ip6_hdr *);
329
330 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
331 ip6stat.ip6s_badvers++;
332 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
333 goto bad;
334 }
335
336 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
337
338 /*
339 * Check against address spoofing/corruption.
340 */
341 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
342 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
343 /*
344 * XXX: "badscope" is not very suitable for a multicast source.
345 */
346 ip6stat.ip6s_badscope++;
347 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
348 goto bad;
349 }
350 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
351 !(m->m_flags & M_LOOP)) {
352 /*
353 * In this case, the packet should come from the loopback
354 * interface. However, we cannot just check the if_flags,
355 * because ip6_mloopback() passes the "actual" interface
356 * as the outgoing/incoming interface.
357 */
358 ip6stat.ip6s_badscope++;
359 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
360 goto bad;
361 }
362
363 #ifdef ALTQ
364 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
365 /* packet is dropped by traffic conditioner */
366 return;
367 }
368 #endif
369 /*
370 * The following check is not documented in specs. A malicious
371 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
372 * and bypass security checks (act as if it was from 127.0.0.1 by using
373 * IPv6 src ::ffff:127.0.0.1). Be cautious.
374 *
375 * This check chokes if we are in an SIIT cloud. As none of BSDs
376 * support IPv4-less kernel compilation, we cannot support SIIT
377 * environment at all. So, it makes more sense for us to reject any
378 * malicious packets for non-SIIT environment, than try to do a
379 * partial support for SIIT environment.
380 */
381 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
382 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
383 ip6stat.ip6s_badscope++;
384 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
385 goto bad;
386 }
387 #if 0
388 /*
389 * Reject packets with IPv4 compatible addresses (auto tunnel).
390 *
391 * The code forbids auto tunnel relay case in RFC1933 (the check is
392 * stronger than RFC1933). We may want to re-enable it if mech-xx
393 * is revised to forbid relaying case.
394 */
395 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
396 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
397 ip6stat.ip6s_badscope++;
398 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
399 goto bad;
400 }
401 #endif
402
403 /*
404 * Drop packets if the link ID portion is already filled.
405 * XXX: this is technically not a good behavior. But, we internally
406 * use the field to disambiguate link-local addresses, so we cannot
407 * be generous against those a bit strange addresses.
408 */
409 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
410 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) &&
411 ip6->ip6_src.s6_addr16[1]) {
412 ip6stat.ip6s_badscope++;
413 goto bad;
414 }
415 if ((IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) ||
416 IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) &&
417 ip6->ip6_dst.s6_addr16[1]) {
418 ip6stat.ip6s_badscope++;
419 goto bad;
420 }
421 }
422
423 /*
424 * Run through list of hooks for input packets.
425 *
426 * NB: Beware of the destination address changing
427 * (e.g. by NAT rewriting). When this happens,
428 * tell ip6_forward to do the right thing.
429 */
430 odst = ip6->ip6_dst;
431
432 /* Jump over all PFIL processing if hooks are not active. */
433 if (inet6_pfil_hook.ph_busy_count == -1)
434 goto passin;
435
436 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL))
437 return;
438 if (m == NULL) /* consumed by filter */
439 return;
440 ip6 = mtod(m, struct ip6_hdr *);
441 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
442
443 passin:
444 /*
445 * Check with the firewall...
446 */
447 if (ip6_fw_enable && ip6_fw_chk_ptr) {
448 u_short port = 0;
449 /* If ipfw says divert, we have to just drop packet */
450 /* use port as a dummy argument */
451 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) {
452 m_freem(m);
453 m = NULL;
454 }
455 if (!m)
456 return;
457 }
458
459 /*
460 * construct source and destination address structures with
461 * disambiguating their scope zones (if there is ambiguity).
462 * XXX: sin6_family and sin6_len will NOT be referred to, but we fill
463 * in these fields just in case.
464 */
465 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_src, &srczone) ||
466 in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst, &dstzone)) {
467 /*
468 * Note that these generic checks cover cases that src or
469 * dst are the loopback address and the receiving interface
470 * is not loopback.
471 */
472 ip6stat.ip6s_badscope++;
473 goto bad;
474 }
475
476 bzero(&sa6, sizeof(sa6));
477 sa6.sin6_family = AF_INET6;
478 sa6.sin6_len = sizeof(struct sockaddr_in6);
479
480 sa6.sin6_addr = ip6->ip6_src;
481 sa6.sin6_scope_id = srczone;
482 if (in6_embedscope(&ip6->ip6_src, &sa6, NULL, NULL)) {
483 /* XXX: should not happen */
484 ip6stat.ip6s_badscope++;
485 goto bad;
486 }
487
488 sa6.sin6_addr = ip6->ip6_dst;
489 sa6.sin6_scope_id = dstzone;
490 if (in6_embedscope(&ip6->ip6_dst, &sa6, NULL, NULL)) {
491 /* XXX: should not happen */
492 ip6stat.ip6s_badscope++;
493 goto bad;
494 }
495
496 /* XXX: ff01::%ifN awareness is not merged, yet. */
497 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_src))
498 ip6->ip6_src.s6_addr16[1] = 0;
499 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst))
500 ip6->ip6_dst.s6_addr16[1] = 0;
501
502 /*
503 * Multicast check
504 */
505 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
506 struct in6_multi *in6m = 0;
507
508 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
509 /*
510 * See if we belong to the destination multicast group on the
511 * arrival interface.
512 */
513 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
514 if (in6m)
515 ours = 1;
516 else if (!ip6_mrouter) {
517 ip6stat.ip6s_notmember++;
518 ip6stat.ip6s_cantforward++;
519 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
520 goto bad;
521 }
522 deliverifp = m->m_pkthdr.rcvif;
523 goto hbhcheck;
524 }
525
526 /*
527 * Unicast check
528 */
529 if (ip6_forward_rt.ro_rt != NULL &&
530 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
531 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
532 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
533 ip6stat.ip6s_forward_cachehit++;
534 else {
535 struct sockaddr_in6 *dst6;
536
537 if (ip6_forward_rt.ro_rt) {
538 /* route is down or destination is different */
539 ip6stat.ip6s_forward_cachemiss++;
540 RTFREE(ip6_forward_rt.ro_rt);
541 ip6_forward_rt.ro_rt = 0;
542 }
543
544 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
545 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
546 dst6->sin6_len = sizeof(struct sockaddr_in6);
547 dst6->sin6_family = AF_INET6;
548 dst6->sin6_addr = ip6->ip6_dst;
549
550 rtalloc((struct route *)&ip6_forward_rt);
551 }
552
553 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
554
555 /*
556 * Accept the packet if the forwarding interface to the destination
557 * according to the routing table is the loopback interface,
558 * unless the associated route has a gateway.
559 * Note that this approach causes to accept a packet if there is a
560 * route to the loopback interface for the destination of the packet.
561 * But we think it's even useful in some situations, e.g. when using
562 * a special daemon which wants to intercept the packet.
563 *
564 * XXX: some OSes automatically make a cloned route for the destination
565 * of an outgoing packet. If the outgoing interface of the packet
566 * is a loopback one, the kernel would consider the packet to be
567 * accepted, even if we have no such address assinged on the interface.
568 * We check the cloned flag of the route entry to reject such cases,
569 * assuming that route entries for our own addresses are not made by
570 * cloning (it should be true because in6_addloop explicitly installs
571 * the host route). However, we might have to do an explicit check
572 * while it would be less efficient. Or, should we rather install a
573 * reject route for such a case?
574 */
575 if (ip6_forward_rt.ro_rt &&
576 (ip6_forward_rt.ro_rt->rt_flags &
577 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
578 #ifdef RTF_WASCLONED
579 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
580 #endif
581 #ifdef RTF_CLONED
582 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
583 #endif
584 #if 0
585 /*
586 * The check below is redundant since the comparison of
587 * the destination and the key of the rtentry has
588 * already done through looking up the routing table.
589 */
590 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
591 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
592 #endif
593 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
594 struct in6_ifaddr *ia6 =
595 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
596
597 /*
598 * record address information into m_tag.
599 */
600 (void)ip6_setdstifaddr(m, ia6);
601
602 /*
603 * packets to a tentative, duplicated, or somehow invalid
604 * address must not be accepted.
605 */
606 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
607 /* this address is ready */
608 ours = 1;
609 deliverifp = ia6->ia_ifp; /* correct? */
610 /* Count the packet in the ip address stats */
611 ia6->ia_ifa.if_ipackets++;
612 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
613 goto hbhcheck;
614 } else {
615 /* address is not ready, so discard the packet. */
616 nd6log((LOG_INFO,
617 "ip6_input: packet to an unready address %s->%s\n",
618 ip6_sprintf(&ip6->ip6_src),
619 ip6_sprintf(&ip6->ip6_dst)));
620
621 goto bad;
622 }
623 }
624
625 /*
626 * FAITH (Firewall Aided Internet Translator)
627 */
628 if (ip6_keepfaith) {
629 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
630 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
631 /* XXX do we need more sanity checks? */
632 ours = 1;
633 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
634 goto hbhcheck;
635 }
636 }
637
638 /*
639 * Now there is no reason to process the packet if it's not our own
640 * and we're not a router.
641 */
642 if (!ip6_forwarding) {
643 ip6stat.ip6s_cantforward++;
644 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
645 goto bad;
646 }
647
648 hbhcheck:
649 /*
650 * record address information into m_tag, if we don't have one yet.
651 * note that we are unable to record it, if the address is not listed
652 * as our interface address (e.g. multicast addresses, addresses
653 * within FAITH prefixes and such).
654 */
655 if (deliverifp && !ip6_getdstifaddr(m)) {
656 struct in6_ifaddr *ia6;
657
658 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
659 if (ia6) {
660 if (!ip6_setdstifaddr(m, ia6)) {
661 /*
662 * XXX maybe we should drop the packet here,
663 * as we could not provide enough information
664 * to the upper layers.
665 */
666 }
667 }
668 }
669
670 /*
671 * Process Hop-by-Hop options header if it's contained.
672 * m may be modified in ip6_hopopts_input().
673 * If a JumboPayload option is included, plen will also be modified.
674 */
675 plen = (u_int32_t)ntohs(ip6->ip6_plen);
676 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
677 struct ip6_hbh *hbh;
678
679 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
680 #if 0 /*touches NULL pointer*/
681 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
682 #endif
683 return; /* m have already been freed */
684 }
685
686 /* adjust pointer */
687 ip6 = mtod(m, struct ip6_hdr *);
688
689 /*
690 * if the payload length field is 0 and the next header field
691 * indicates Hop-by-Hop Options header, then a Jumbo Payload
692 * option MUST be included.
693 */
694 if (ip6->ip6_plen == 0 && plen == 0) {
695 /*
696 * Note that if a valid jumbo payload option is
697 * contained, ip6_hopopts_input() must set a valid
698 * (non-zero) payload length to the variable plen.
699 */
700 ip6stat.ip6s_badoptions++;
701 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
702 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
703 icmp6_error(m, ICMP6_PARAM_PROB,
704 ICMP6_PARAMPROB_HEADER,
705 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
706 return;
707 }
708 #ifndef PULLDOWN_TEST
709 /* ip6_hopopts_input() ensures that mbuf is contiguous */
710 hbh = (struct ip6_hbh *)(ip6 + 1);
711 #else
712 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
713 sizeof(struct ip6_hbh));
714 if (hbh == NULL) {
715 ip6stat.ip6s_tooshort++;
716 return;
717 }
718 #endif
719 nxt = hbh->ip6h_nxt;
720
721 /*
722 * accept the packet if a router alert option is included
723 * and we act as an IPv6 router.
724 */
725 if (rtalert != ~0 && ip6_forwarding)
726 ours = 1;
727 } else
728 nxt = ip6->ip6_nxt;
729
730 /*
731 * Check that the amount of data in the buffers
732 * is as at least much as the IPv6 header would have us expect.
733 * Trim mbufs if longer than we expect.
734 * Drop packet if shorter than we expect.
735 */
736 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
737 ip6stat.ip6s_tooshort++;
738 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
739 goto bad;
740 }
741 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
742 if (m->m_len == m->m_pkthdr.len) {
743 m->m_len = sizeof(struct ip6_hdr) + plen;
744 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
745 } else
746 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
747 }
748
749 /*
750 * Forward if desirable.
751 */
752 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
753 /*
754 * If we are acting as a multicast router, all
755 * incoming multicast packets are passed to the
756 * kernel-level multicast forwarding function.
757 * The packet is returned (relatively) intact; if
758 * ip6_mforward() returns a non-zero value, the packet
759 * must be discarded, else it may be accepted below.
760 */
761 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
762 ip6stat.ip6s_cantforward++;
763 m_freem(m);
764 return;
765 }
766 if (!ours) {
767 m_freem(m);
768 return;
769 }
770 } else if (!ours) {
771 ip6_forward(m, srcrt);
772 return;
773 }
774
775 ip6 = mtod(m, struct ip6_hdr *);
776
777 /*
778 * Malicious party may be able to use IPv4 mapped addr to confuse
779 * tcp/udp stack and bypass security checks (act as if it was from
780 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
781 *
782 * For SIIT end node behavior, you may want to disable the check.
783 * However, you will become vulnerable to attacks using IPv4 mapped
784 * source.
785 */
786 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
787 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
788 ip6stat.ip6s_badscope++;
789 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
790 goto bad;
791 }
792
793 /*
794 * Tell launch routine the next header
795 */
796 ip6stat.ip6s_delivered++;
797 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
798 nest = 0;
799
800 while (nxt != IPPROTO_DONE) {
801 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
802 ip6stat.ip6s_toomanyhdr++;
803 goto bad;
804 }
805
806 /*
807 * protection against faulty packet - there should be
808 * more sanity checks in header chain processing.
809 */
810 if (m->m_pkthdr.len < off) {
811 ip6stat.ip6s_tooshort++;
812 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
813 goto bad;
814 }
815
816 #ifdef IPSEC
817 /*
818 * enforce IPsec policy checking if we are seeing last header.
819 * note that we do not visit this with protocols with pcb layer
820 * code - like udp/tcp/raw ip.
821 */
822 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
823 ipsec6_in_reject(m, NULL)) {
824 ipsec6stat.in_polvio++;
825 goto bad;
826 }
827 #endif
828 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
829 }
830 return;
831 bad:
832 m_freem(m);
833 }
834
835 /*
836 * set/grab in6_ifaddr correspond to IPv6 destination address.
837 * XXX backward compatibility wrapper
838 */
839 static struct ip6aux *
840 ip6_setdstifaddr(m, ia6)
841 struct mbuf *m;
842 struct in6_ifaddr *ia6;
843 {
844 struct ip6aux *ip6a;
845
846 ip6a = ip6_addaux(m);
847 if (ip6a)
848 ip6a->ip6a_dstia6 = ia6;
849 return ip6a; /* NULL if failed to set */
850 }
851
852 struct in6_ifaddr *
853 ip6_getdstifaddr(m)
854 struct mbuf *m;
855 {
856 struct ip6aux *ip6a;
857
858 ip6a = ip6_findaux(m);
859 if (ip6a)
860 return ip6a->ip6a_dstia6;
861 else
862 return NULL;
863 }
864
865 /*
866 * Hop-by-Hop options header processing. If a valid jumbo payload option is
867 * included, the real payload length will be stored in plenp.
868 */
869 static int
870 ip6_hopopts_input(plenp, rtalertp, mp, offp)
871 u_int32_t *plenp;
872 u_int32_t *rtalertp; /* XXX: should be stored more smart way */
873 struct mbuf **mp;
874 int *offp;
875 {
876 struct mbuf *m = *mp;
877 int off = *offp, hbhlen;
878 struct ip6_hbh *hbh;
879 u_int8_t *opt;
880
881 /* validation of the length of the header */
882 #ifndef PULLDOWN_TEST
883 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
884 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
885 hbhlen = (hbh->ip6h_len + 1) << 3;
886
887 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
888 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
889 #else
890 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
891 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
892 if (hbh == NULL) {
893 ip6stat.ip6s_tooshort++;
894 return -1;
895 }
896 hbhlen = (hbh->ip6h_len + 1) << 3;
897 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
898 hbhlen);
899 if (hbh == NULL) {
900 ip6stat.ip6s_tooshort++;
901 return -1;
902 }
903 #endif
904 off += hbhlen;
905 hbhlen -= sizeof(struct ip6_hbh);
906 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
907
908 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
909 hbhlen, rtalertp, plenp) < 0)
910 return (-1);
911
912 *offp = off;
913 *mp = m;
914 return (0);
915 }
916
917 /*
918 * Search header for all Hop-by-hop options and process each option.
919 * This function is separate from ip6_hopopts_input() in order to
920 * handle a case where the sending node itself process its hop-by-hop
921 * options header. In such a case, the function is called from ip6_output().
922 *
923 * The function assumes that hbh header is located right after the IPv6 header
924 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
925 * opthead + hbhlen is located in continuous memory region.
926 */
927 int
928 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp)
929 struct mbuf *m;
930 u_int8_t *opthead;
931 int hbhlen;
932 u_int32_t *rtalertp;
933 u_int32_t *plenp;
934 {
935 struct ip6_hdr *ip6;
936 int optlen = 0;
937 u_int8_t *opt = opthead;
938 u_int16_t rtalert_val;
939 u_int32_t jumboplen;
940 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
941
942 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
943 switch (*opt) {
944 case IP6OPT_PAD1:
945 optlen = 1;
946 break;
947 case IP6OPT_PADN:
948 if (hbhlen < IP6OPT_MINLEN) {
949 ip6stat.ip6s_toosmall++;
950 goto bad;
951 }
952 optlen = *(opt + 1) + 2;
953 break;
954 case IP6OPT_ROUTER_ALERT:
955 /* XXX may need check for alignment */
956 if (hbhlen < IP6OPT_RTALERT_LEN) {
957 ip6stat.ip6s_toosmall++;
958 goto bad;
959 }
960 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
961 /* XXX stat */
962 icmp6_error(m, ICMP6_PARAM_PROB,
963 ICMP6_PARAMPROB_HEADER,
964 erroff + opt + 1 - opthead);
965 return (-1);
966 }
967 optlen = IP6OPT_RTALERT_LEN;
968 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
969 *rtalertp = ntohs(rtalert_val);
970 break;
971 case IP6OPT_JUMBO:
972 /* XXX may need check for alignment */
973 if (hbhlen < IP6OPT_JUMBO_LEN) {
974 ip6stat.ip6s_toosmall++;
975 goto bad;
976 }
977 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
978 /* XXX stat */
979 icmp6_error(m, ICMP6_PARAM_PROB,
980 ICMP6_PARAMPROB_HEADER,
981 erroff + opt + 1 - opthead);
982 return (-1);
983 }
984 optlen = IP6OPT_JUMBO_LEN;
985
986 /*
987 * IPv6 packets that have non 0 payload length
988 * must not contain a jumbo payload option.
989 */
990 ip6 = mtod(m, struct ip6_hdr *);
991 if (ip6->ip6_plen) {
992 ip6stat.ip6s_badoptions++;
993 icmp6_error(m, ICMP6_PARAM_PROB,
994 ICMP6_PARAMPROB_HEADER,
995 erroff + opt - opthead);
996 return (-1);
997 }
998
999 /*
1000 * We may see jumbolen in unaligned location, so
1001 * we'd need to perform bcopy().
1002 */
1003 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1004 jumboplen = (u_int32_t)htonl(jumboplen);
1005
1006 #if 1
1007 /*
1008 * if there are multiple jumbo payload options,
1009 * *plenp will be non-zero and the packet will be
1010 * rejected.
1011 * the behavior may need some debate in ipngwg -
1012 * multiple options does not make sense, however,
1013 * there's no explicit mention in specification.
1014 */
1015 if (*plenp != 0) {
1016 ip6stat.ip6s_badoptions++;
1017 icmp6_error(m, ICMP6_PARAM_PROB,
1018 ICMP6_PARAMPROB_HEADER,
1019 erroff + opt + 2 - opthead);
1020 return (-1);
1021 }
1022 #endif
1023
1024 /*
1025 * jumbo payload length must be larger than 65535.
1026 */
1027 if (jumboplen <= IPV6_MAXPACKET) {
1028 ip6stat.ip6s_badoptions++;
1029 icmp6_error(m, ICMP6_PARAM_PROB,
1030 ICMP6_PARAMPROB_HEADER,
1031 erroff + opt + 2 - opthead);
1032 return (-1);
1033 }
1034 *plenp = jumboplen;
1035
1036 break;
1037 default: /* unknown option */
1038 if (hbhlen < IP6OPT_MINLEN) {
1039 ip6stat.ip6s_toosmall++;
1040 goto bad;
1041 }
1042 optlen = ip6_unknown_opt(opt, m,
1043 erroff + opt - opthead);
1044 if (optlen == -1)
1045 return (-1);
1046 optlen += 2;
1047 break;
1048 }
1049 }
1050
1051 return (0);
1052
1053 bad:
1054 m_freem(m);
1055 return (-1);
1056 }
1057
1058 /*
1059 * Unknown option processing.
1060 * The third argument `off' is the offset from the IPv6 header to the option,
1061 * which is necessary if the IPv6 header the and option header and IPv6 header
1062 * is not continuous in order to return an ICMPv6 error.
1063 */
1064 int
1065 ip6_unknown_opt(optp, m, off)
1066 u_int8_t *optp;
1067 struct mbuf *m;
1068 int off;
1069 {
1070 struct ip6_hdr *ip6;
1071
1072 switch (IP6OPT_TYPE(*optp)) {
1073 case IP6OPT_TYPE_SKIP: /* ignore the option */
1074 return ((int)*(optp + 1));
1075 case IP6OPT_TYPE_DISCARD: /* silently discard */
1076 m_freem(m);
1077 return (-1);
1078 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1079 ip6stat.ip6s_badoptions++;
1080 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1081 return (-1);
1082 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1083 ip6stat.ip6s_badoptions++;
1084 ip6 = mtod(m, struct ip6_hdr *);
1085 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1086 (m->m_flags & (M_BCAST|M_MCAST)))
1087 m_freem(m);
1088 else
1089 icmp6_error(m, ICMP6_PARAM_PROB,
1090 ICMP6_PARAMPROB_OPTION, off);
1091 return (-1);
1092 }
1093
1094 m_freem(m); /* XXX: NOTREACHED */
1095 return (-1);
1096 }
1097
1098 /*
1099 * Create the "control" list for this pcb.
1100 * The function will not modify mbuf chain at all.
1101 *
1102 * with KAME mbuf chain restriction:
1103 * The routine will be called from upper layer handlers like tcp6_input().
1104 * Thus the routine assumes that the caller (tcp6_input) have already
1105 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1106 * very first mbuf on the mbuf chain.
1107 */
1108 void
1109 ip6_savecontrol(in6p, m, mp)
1110 struct inpcb *in6p;
1111 struct mbuf *m, **mp;
1112 {
1113 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
1114 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1115
1116 #ifdef SO_TIMESTAMP
1117 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) {
1118 struct timeval tv;
1119
1120 microtime(&tv);
1121 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1122 SCM_TIMESTAMP, SOL_SOCKET);
1123 if (*mp)
1124 mp = &(*mp)->m_next;
1125 }
1126 #endif
1127
1128 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
1129 return;
1130
1131 /* RFC 2292 sec. 5 */
1132 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
1133 struct in6_pktinfo pi6;
1134
1135 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1136 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1137 pi6.ipi6_ifindex =
1138 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1139
1140 *mp = sbcreatecontrol((caddr_t) &pi6,
1141 sizeof(struct in6_pktinfo),
1142 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1143 if (*mp)
1144 mp = &(*mp)->m_next;
1145 }
1146
1147 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) {
1148 int hlim = ip6->ip6_hlim & 0xff;
1149
1150 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1151 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6);
1152 if (*mp)
1153 mp = &(*mp)->m_next;
1154 }
1155
1156 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
1157 u_int32_t flowinfo;
1158 int tclass;
1159
1160 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1161 flowinfo >>= 20;
1162
1163 tclass = flowinfo & 0xff;
1164 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
1165 IPV6_TCLASS, IPPROTO_IPV6);
1166 if (*mp)
1167 mp = &(*mp)->m_next;
1168 }
1169
1170 /*
1171 * IPV6_HOPOPTS socket option. Recall that we required super-user
1172 * privilege for the option (see ip6_ctloutput), but it might be too
1173 * strict, since there might be some hop-by-hop options which can be
1174 * returned to normal user.
1175 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1176 */
1177 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
1178 /*
1179 * Check if a hop-by-hop options header is contatined in the
1180 * received packet, and if so, store the options as ancillary
1181 * data. Note that a hop-by-hop options header must be
1182 * just after the IPv6 header, which is assured through the
1183 * IPv6 input processing.
1184 */
1185 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1186 struct ip6_hbh *hbh;
1187 int hbhlen = 0;
1188 #ifdef PULLDOWN_TEST
1189 struct mbuf *ext;
1190 #endif
1191
1192 #ifndef PULLDOWN_TEST
1193 hbh = (struct ip6_hbh *)(ip6 + 1);
1194 hbhlen = (hbh->ip6h_len + 1) << 3;
1195 #else
1196 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1197 ip6->ip6_nxt);
1198 if (ext == NULL) {
1199 ip6stat.ip6s_tooshort++;
1200 return;
1201 }
1202 hbh = mtod(ext, struct ip6_hbh *);
1203 hbhlen = (hbh->ip6h_len + 1) << 3;
1204 if (hbhlen != ext->m_len) {
1205 m_freem(ext);
1206 ip6stat.ip6s_tooshort++;
1207 return;
1208 }
1209 #endif
1210
1211 /*
1212 * XXX: We copy the whole header even if a
1213 * jumbo payload option is included, the option which
1214 * is to be removed before returning according to
1215 * RFC2292.
1216 * Note: this constraint is removed in RFC3542
1217 */
1218 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1219 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1220 IPPROTO_IPV6);
1221 if (*mp)
1222 mp = &(*mp)->m_next;
1223 #ifdef PULLDOWN_TEST
1224 m_freem(ext);
1225 #endif
1226 }
1227 }
1228
1229 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1230 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1231
1232 /*
1233 * Search for destination options headers or routing
1234 * header(s) through the header chain, and stores each
1235 * header as ancillary data.
1236 * Note that the order of the headers remains in
1237 * the chain of ancillary data.
1238 */
1239 while (1) { /* is explicit loop prevention necessary? */
1240 struct ip6_ext *ip6e = NULL;
1241 int elen;
1242 #ifdef PULLDOWN_TEST
1243 struct mbuf *ext = NULL;
1244 #endif
1245
1246 /*
1247 * if it is not an extension header, don't try to
1248 * pull it from the chain.
1249 */
1250 switch (nxt) {
1251 case IPPROTO_DSTOPTS:
1252 case IPPROTO_ROUTING:
1253 case IPPROTO_HOPOPTS:
1254 case IPPROTO_AH: /* is it possible? */
1255 break;
1256 default:
1257 goto loopend;
1258 }
1259
1260 #ifndef PULLDOWN_TEST
1261 if (off + sizeof(*ip6e) > m->m_len)
1262 goto loopend;
1263 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1264 if (nxt == IPPROTO_AH)
1265 elen = (ip6e->ip6e_len + 2) << 2;
1266 else
1267 elen = (ip6e->ip6e_len + 1) << 3;
1268 if (off + elen > m->m_len)
1269 goto loopend;
1270 #else
1271 ext = ip6_pullexthdr(m, off, nxt);
1272 if (ext == NULL) {
1273 ip6stat.ip6s_tooshort++;
1274 return;
1275 }
1276 ip6e = mtod(ext, struct ip6_ext *);
1277 if (nxt == IPPROTO_AH)
1278 elen = (ip6e->ip6e_len + 2) << 2;
1279 else
1280 elen = (ip6e->ip6e_len + 1) << 3;
1281 if (elen != ext->m_len) {
1282 m_freem(ext);
1283 ip6stat.ip6s_tooshort++;
1284 return;
1285 }
1286 #endif
1287
1288 switch (nxt) {
1289 case IPPROTO_DSTOPTS:
1290 if (!(in6p->in6p_flags & IN6P_DSTOPTS))
1291 break;
1292
1293 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1294 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1295 IPPROTO_IPV6);
1296 if (*mp)
1297 mp = &(*mp)->m_next;
1298 break;
1299 case IPPROTO_ROUTING:
1300 if (!in6p->in6p_flags & IN6P_RTHDR)
1301 break;
1302
1303 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1304 IS2292(IPV6_2292RTHDR, IPV6_RTHDR),
1305 IPPROTO_IPV6);
1306 if (*mp)
1307 mp = &(*mp)->m_next;
1308 break;
1309 case IPPROTO_HOPOPTS:
1310 case IPPROTO_AH: /* is it possible? */
1311 break;
1312
1313 default:
1314 /*
1315 * other cases have been filtered in the above.
1316 * none will visit this case. here we supply
1317 * the code just in case (nxt overwritten or
1318 * other cases).
1319 */
1320 #ifdef PULLDOWN_TEST
1321 m_freem(ext);
1322 #endif
1323 goto loopend;
1324
1325 }
1326
1327 /* proceed with the next header. */
1328 off += elen;
1329 nxt = ip6e->ip6e_nxt;
1330 ip6e = NULL;
1331 #ifdef PULLDOWN_TEST
1332 m_freem(ext);
1333 ext = NULL;
1334 #endif
1335 }
1336 loopend:
1337 ;
1338 }
1339
1340 #undef IS2292
1341 }
1342
1343 void
1344 ip6_notify_pmtu(in6p, dst, mtu)
1345 struct inpcb *in6p;
1346 struct sockaddr_in6 *dst;
1347 u_int32_t *mtu;
1348 {
1349 struct socket *so;
1350 struct mbuf *m_mtu;
1351 struct ip6_mtuinfo mtuctl;
1352
1353 so = in6p->inp_socket;
1354
1355 if (mtu == NULL)
1356 return;
1357
1358 #ifdef DIAGNOSTIC
1359 if (so == NULL) /* I believe this is impossible */
1360 panic("ip6_notify_pmtu: socket is NULL");
1361 #endif
1362
1363 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
1364 mtuctl.ip6m_mtu = *mtu;
1365 mtuctl.ip6m_addr = *dst;
1366 in6_recoverscope(&mtuctl.ip6m_addr, &mtuctl.ip6m_addr.sin6_addr, NULL);
1367
1368 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1369 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1370 return;
1371
1372 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1373 == 0) {
1374 m_freem(m_mtu);
1375 /* XXX: should count statistics */
1376 } else
1377 sorwakeup(so);
1378
1379 return;
1380 }
1381
1382 #ifdef PULLDOWN_TEST
1383 /*
1384 * pull single extension header from mbuf chain. returns single mbuf that
1385 * contains the result, or NULL on error.
1386 */
1387 static struct mbuf *
1388 ip6_pullexthdr(m, off, nxt)
1389 struct mbuf *m;
1390 size_t off;
1391 int nxt;
1392 {
1393 struct ip6_ext ip6e;
1394 size_t elen;
1395 struct mbuf *n;
1396
1397 #ifdef DIAGNOSTIC
1398 switch (nxt) {
1399 case IPPROTO_DSTOPTS:
1400 case IPPROTO_ROUTING:
1401 case IPPROTO_HOPOPTS:
1402 case IPPROTO_AH: /* is it possible? */
1403 break;
1404 default:
1405 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1406 }
1407 #endif
1408
1409 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1410 if (nxt == IPPROTO_AH)
1411 elen = (ip6e.ip6e_len + 2) << 2;
1412 else
1413 elen = (ip6e.ip6e_len + 1) << 3;
1414
1415 MGET(n, M_DONTWAIT, MT_DATA);
1416 if (n && elen >= MLEN) {
1417 MCLGET(n, M_DONTWAIT);
1418 if ((n->m_flags & M_EXT) == 0) {
1419 m_free(n);
1420 n = NULL;
1421 }
1422 }
1423 if (!n)
1424 return NULL;
1425
1426 n->m_len = 0;
1427 if (elen >= M_TRAILINGSPACE(n)) {
1428 m_free(n);
1429 return NULL;
1430 }
1431
1432 m_copydata(m, off, elen, mtod(n, caddr_t));
1433 n->m_len = elen;
1434 return n;
1435 }
1436 #endif
1437
1438 /*
1439 * Get pointer to the previous header followed by the header
1440 * currently processed.
1441 * XXX: This function supposes that
1442 * M includes all headers,
1443 * the next header field and the header length field of each header
1444 * are valid, and
1445 * the sum of each header length equals to OFF.
1446 * Because of these assumptions, this function must be called very
1447 * carefully. Moreover, it will not be used in the near future when
1448 * we develop `neater' mechanism to process extension headers.
1449 */
1450 char *
1451 ip6_get_prevhdr(m, off)
1452 struct mbuf *m;
1453 int off;
1454 {
1455 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1456
1457 if (off == sizeof(struct ip6_hdr))
1458 return (&ip6->ip6_nxt);
1459 else {
1460 int len, nxt;
1461 struct ip6_ext *ip6e = NULL;
1462
1463 nxt = ip6->ip6_nxt;
1464 len = sizeof(struct ip6_hdr);
1465 while (len < off) {
1466 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1467
1468 switch (nxt) {
1469 case IPPROTO_FRAGMENT:
1470 len += sizeof(struct ip6_frag);
1471 break;
1472 case IPPROTO_AH:
1473 len += (ip6e->ip6e_len + 2) << 2;
1474 break;
1475 default:
1476 len += (ip6e->ip6e_len + 1) << 3;
1477 break;
1478 }
1479 nxt = ip6e->ip6e_nxt;
1480 }
1481 if (ip6e)
1482 return (&ip6e->ip6e_nxt);
1483 else
1484 return NULL;
1485 }
1486 }
1487
1488 /*
1489 * get next header offset. m will be retained.
1490 */
1491 int
1492 ip6_nexthdr(m, off, proto, nxtp)
1493 struct mbuf *m;
1494 int off;
1495 int proto;
1496 int *nxtp;
1497 {
1498 struct ip6_hdr ip6;
1499 struct ip6_ext ip6e;
1500 struct ip6_frag fh;
1501
1502 /* just in case */
1503 if (m == NULL)
1504 panic("ip6_nexthdr: m == NULL");
1505 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1506 return -1;
1507
1508 switch (proto) {
1509 case IPPROTO_IPV6:
1510 if (m->m_pkthdr.len < off + sizeof(ip6))
1511 return -1;
1512 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1513 if (nxtp)
1514 *nxtp = ip6.ip6_nxt;
1515 off += sizeof(ip6);
1516 return off;
1517
1518 case IPPROTO_FRAGMENT:
1519 /*
1520 * terminate parsing if it is not the first fragment,
1521 * it does not make sense to parse through it.
1522 */
1523 if (m->m_pkthdr.len < off + sizeof(fh))
1524 return -1;
1525 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1526 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1527 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1528 return -1;
1529 if (nxtp)
1530 *nxtp = fh.ip6f_nxt;
1531 off += sizeof(struct ip6_frag);
1532 return off;
1533
1534 case IPPROTO_AH:
1535 if (m->m_pkthdr.len < off + sizeof(ip6e))
1536 return -1;
1537 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1538 if (nxtp)
1539 *nxtp = ip6e.ip6e_nxt;
1540 off += (ip6e.ip6e_len + 2) << 2;
1541 return off;
1542
1543 case IPPROTO_HOPOPTS:
1544 case IPPROTO_ROUTING:
1545 case IPPROTO_DSTOPTS:
1546 if (m->m_pkthdr.len < off + sizeof(ip6e))
1547 return -1;
1548 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1549 if (nxtp)
1550 *nxtp = ip6e.ip6e_nxt;
1551 off += (ip6e.ip6e_len + 1) << 3;
1552 return off;
1553
1554 case IPPROTO_NONE:
1555 case IPPROTO_ESP:
1556 case IPPROTO_IPCOMP:
1557 /* give up */
1558 return -1;
1559
1560 default:
1561 return -1;
1562 }
1563
1564 return -1;
1565 }
1566
1567 /*
1568 * get offset for the last header in the chain. m will be kept untainted.
1569 */
1570 int
1571 ip6_lasthdr(m, off, proto, nxtp)
1572 struct mbuf *m;
1573 int off;
1574 int proto;
1575 int *nxtp;
1576 {
1577 int newoff;
1578 int nxt;
1579
1580 if (!nxtp) {
1581 nxt = -1;
1582 nxtp = &nxt;
1583 }
1584 while (1) {
1585 newoff = ip6_nexthdr(m, off, proto, nxtp);
1586 if (newoff < 0)
1587 return off;
1588 else if (newoff < off)
1589 return -1; /* invalid */
1590 else if (newoff == off)
1591 return newoff;
1592
1593 off = newoff;
1594 proto = *nxtp;
1595 }
1596 }
1597
1598 struct ip6aux *
1599 ip6_addaux(m)
1600 struct mbuf *m;
1601 {
1602 struct m_tag *mtag;
1603
1604 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1605 if (!mtag) {
1606 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1607 M_NOWAIT);
1608 if (mtag) {
1609 m_tag_prepend(m, mtag);
1610 bzero(mtag + 1, sizeof(struct ip6aux));
1611 }
1612 }
1613 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1614 }
1615
1616 struct ip6aux *
1617 ip6_findaux(m)
1618 struct mbuf *m;
1619 {
1620 struct m_tag *mtag;
1621
1622 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1623 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1624 }
1625
1626 void
1627 ip6_delaux(m)
1628 struct mbuf *m;
1629 {
1630 struct m_tag *mtag;
1631
1632 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1633 if (mtag)
1634 m_tag_delete(m, mtag);
1635 }
1636
1637 /*
1638 * System control for IP6
1639 */
1640
1641 u_char inet6ctlerrmap[PRC_NCMDS] = {
1642 0, 0, 0, 0,
1643 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1644 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1645 EMSGSIZE, EHOSTUNREACH, 0, 0,
1646 0, 0, 0, 0,
1647 ENOPROTOOPT
1648 };
Cache object: 74efbf4c158d0b09cbfa3e1f1acae8ba
|