1 /* $FreeBSD: src/sys/netinet6/ip6_input.c,v 1.11.2.15 2003/01/24 05:11:35 sam Exp $ */
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 * 3. 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/domain.h>
74 #include <sys/protosw.h>
75 #include <sys/socket.h>
76 #include <sys/socketvar.h>
77 #include <sys/errno.h>
78 #include <sys/time.h>
79 #include <sys/kernel.h>
80 #include <sys/syslog.h>
81 #include <sys/proc.h>
82 #include <sys/priv.h>
83
84 #include <net/if.h>
85 #include <net/if_types.h>
86 #include <net/if_dl.h>
87 #include <net/route.h>
88 #include <net/netisr.h>
89 #include <net/pfil.h>
90
91 #include <sys/thread2.h>
92 #include <sys/msgport2.h>
93 #include <net/netmsg2.h>
94 #include <net/netisr2.h>
95
96 #include <netinet/in.h>
97 #include <netinet/in_systm.h>
98 #ifdef INET
99 #include <netinet/ip.h>
100 #include <netinet/ip_icmp.h>
101 #endif /* INET */
102 #include <netinet/ip6.h>
103 #include <netinet6/in6_var.h>
104 #include <netinet6/ip6_var.h>
105 #include <netinet/in_pcb.h>
106 #include <netinet/icmp6.h>
107 #include <netinet6/scope6_var.h>
108 #include <netinet6/in6_ifattach.h>
109 #include <netinet6/nd6.h>
110 #include <netinet6/in6_prefix.h>
111
112 #ifdef IPSEC
113 #include <netinet6/ipsec.h>
114 #ifdef INET6
115 #include <netinet6/ipsec6.h>
116 #endif
117 #endif
118
119 #ifdef FAST_IPSEC
120 #include <netproto/ipsec/ipsec.h>
121 #include <netproto/ipsec/ipsec6.h>
122 #define IPSEC
123 #endif /* FAST_IPSEC */
124
125 #include <net/ip6fw/ip6_fw.h>
126
127 #include <netinet6/ip6protosw.h>
128
129 #include <net/net_osdep.h>
130
131 extern struct domain inet6domain;
132 extern struct protosw inet6sw[];
133
134 u_char ip6_protox[IPPROTO_MAX];
135 struct in6_ifaddr *in6_ifaddr;
136
137 extern struct callout in6_tmpaddrtimer_ch;
138
139 int ip6_forward_srcrt; /* XXX */
140 int ip6_sourcecheck; /* XXX */
141 int ip6_sourcecheck_interval; /* XXX */
142
143 int ip6_ours_check_algorithm;
144
145 struct pfil_head inet6_pfil_hook;
146
147 /* firewall hooks */
148 ip6_fw_chk_t *ip6_fw_chk_ptr;
149 ip6_fw_ctl_t *ip6_fw_ctl_ptr;
150 int ip6_fw_enable = 1;
151
152 struct ip6stat ip6stat;
153
154 static void ip6_init2 (void *);
155 static struct ip6aux *ip6_setdstifaddr (struct mbuf *, struct in6_ifaddr *);
156 static int ip6_hopopts_input (u_int32_t *, u_int32_t *, struct mbuf **, int *);
157 static void ip6_input(netmsg_t msg);
158 #ifdef PULLDOWN_TEST
159 static struct mbuf *ip6_pullexthdr (struct mbuf *, size_t, int);
160 #endif
161 static void transport6_processing_handler(netmsg_t netmsg);
162
163 /*
164 * IP6 initialization: fill in IP6 protocol switch table.
165 * All protocols not implemented in kernel go to raw IP6 protocol handler.
166 */
167 void
168 ip6_init(void)
169 {
170 struct protosw *pr;
171 int i;
172 struct timeval tv;
173
174 pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
175 if (pr == NULL)
176 panic("ip6_init");
177 for (i = 0; i < IPPROTO_MAX; i++)
178 ip6_protox[i] = pr - inet6sw;
179 for (pr = inet6domain.dom_protosw;
180 pr < inet6domain.dom_protoswNPROTOSW; pr++)
181 if (pr->pr_domain->dom_family == PF_INET6 &&
182 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
183 ip6_protox[pr->pr_protocol] = pr - inet6sw;
184
185 inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
186 inet6_pfil_hook.ph_af = AF_INET6;
187 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0) {
188 kprintf("%s: WARNING: unable to register pfil hook, "
189 "error %d\n", __func__, i);
190 }
191
192 netisr_register(NETISR_IPV6, ip6_input, NULL); /* XXX hashfn */
193 scope6_init();
194 addrsel_policy_init();
195 nd6_init();
196 frag6_init();
197 /*
198 * in many cases, random() here does NOT return random number
199 * as initialization during bootstrap time occur in fixed order.
200 */
201 microtime(&tv);
202 ip6_flow_seq = krandom() ^ tv.tv_usec;
203 microtime(&tv);
204 ip6_desync_factor = (krandom() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR;
205 }
206
207 static void
208 ip6_init2(void *dummy)
209 {
210 /* nd6_timer_init */
211 callout_init(&nd6_timer_ch);
212 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
213
214 /* router renumbering prefix list maintenance */
215 callout_init(&in6_rr_timer_ch);
216 callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL);
217
218 /* timer for regeneranation of temporary addresses randomize ID */
219 callout_init(&in6_tmpaddrtimer_ch);
220 callout_reset(&in6_tmpaddrtimer_ch,
221 (ip6_temp_preferred_lifetime - ip6_desync_factor -
222 ip6_temp_regen_advance) * hz,
223 in6_tmpaddrtimer, NULL);
224 }
225
226 /* cheat */
227 /* This must be after route_init(), which is now SI_ORDER_THIRD */
228 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
229
230 extern struct route_in6 ip6_forward_rt;
231
232 static
233 void
234 ip6_input(netmsg_t msg)
235 {
236 struct mbuf *m = msg->packet.nm_packet;
237 struct ip6_hdr *ip6;
238 int off = sizeof(struct ip6_hdr), nest;
239 u_int32_t plen;
240 u_int32_t rtalert = ~0;
241 int nxt, ours = 0, rh_present = 0;
242 struct ifnet *deliverifp = NULL;
243 struct in6_addr odst;
244 int srcrt = 0;
245
246 #ifdef IPSEC
247 /*
248 * should the inner packet be considered authentic?
249 * see comment in ah4_input().
250 */
251 if (m) {
252 m->m_flags &= ~M_AUTHIPHDR;
253 m->m_flags &= ~M_AUTHIPDGM;
254 }
255 #endif
256
257 /*
258 * make sure we don't have onion peering information into m_aux.
259 */
260 ip6_delaux(m);
261
262 /*
263 * mbuf statistics
264 */
265 if (m->m_flags & M_EXT) {
266 if (m->m_next)
267 ip6stat.ip6s_mext2m++;
268 else
269 ip6stat.ip6s_mext1++;
270 } else {
271 #define M2MMAX NELEM(ip6stat.ip6s_m2m)
272 if (m->m_next) {
273 if (m->m_flags & M_LOOP) {
274 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */
275 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
276 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
277 else
278 ip6stat.ip6s_m2m[0]++;
279 } else
280 ip6stat.ip6s_m1++;
281 #undef M2MMAX
282 }
283
284 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
285 ip6stat.ip6s_total++;
286
287 #ifndef PULLDOWN_TEST
288 /*
289 * L2 bridge code and some other code can return mbuf chain
290 * that does not conform to KAME requirement. too bad.
291 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
292 */
293 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
294 struct mbuf *n;
295
296 n = m_getb(m->m_pkthdr.len, MB_DONTWAIT, MT_HEADER, M_PKTHDR);
297 if (n == NULL)
298 goto bad;
299 M_MOVE_PKTHDR(n, m);
300
301 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
302 n->m_len = n->m_pkthdr.len;
303 m_freem(m);
304 m = n;
305 }
306 IP6_EXTHDR_CHECK_VOIDRET(m, 0, sizeof(struct ip6_hdr));
307 #endif
308
309 if (m->m_len < sizeof(struct ip6_hdr)) {
310 struct ifnet *inifp;
311 inifp = m->m_pkthdr.rcvif;
312 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
313 ip6stat.ip6s_toosmall++;
314 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
315 goto bad2;
316 }
317 }
318
319 ip6 = mtod(m, struct ip6_hdr *);
320
321 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
322 ip6stat.ip6s_badvers++;
323 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
324 goto bad;
325 }
326
327 /*
328 * Run through list of hooks for input packets.
329 *
330 * NB: Beware of the destination address changing
331 * (e.g. by NAT rewriting). When this happens,
332 * tell ip6_forward to do the right thing.
333 */
334 if (pfil_has_hooks(&inet6_pfil_hook)) {
335 odst = ip6->ip6_dst;
336 if (pfil_run_hooks(&inet6_pfil_hook, &m,
337 m->m_pkthdr.rcvif, PFIL_IN)) {
338 goto bad2;
339 }
340 if (m == NULL) /* consumed by filter */
341 goto bad2;
342 ip6 = mtod(m, struct ip6_hdr *);
343 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
344 }
345
346 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
347
348 #ifdef ALTQ
349 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
350 /* packet is dropped by traffic conditioner */
351 return;
352 }
353 #endif
354
355 /*
356 * Check with the firewall...
357 */
358 if (ip6_fw_enable && ip6_fw_chk_ptr) {
359 u_short port = 0;
360 /* If ipfw says divert, we have to just drop packet */
361 /* use port as a dummy argument */
362 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) {
363 m_freem(m);
364 m = NULL;
365 }
366 if (!m)
367 goto bad2;
368 }
369
370 /*
371 * Check against address spoofing/corruption.
372 */
373 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
374 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
375 /*
376 * XXX: "badscope" is not very suitable for a multicast source.
377 */
378 ip6stat.ip6s_badscope++;
379 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
380 goto bad;
381 }
382 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) ||
383 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) &&
384 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
385 ip6stat.ip6s_badscope++;
386 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
387 goto bad;
388 }
389
390 /*
391 * The following check is not documented in specs. A malicious
392 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
393 * and bypass security checks (act as if it was from 127.0.0.1 by using
394 * IPv6 src ::ffff:127.0.0.1). Be cautious.
395 *
396 * This check chokes if we are in an SIIT cloud. As none of BSDs
397 * support IPv4-less kernel compilation, we cannot support SIIT
398 * environment at all. So, it makes more sense for us to reject any
399 * malicious packets for non-SIIT environment, than try to do a
400 * partical support for SIIT environment.
401 */
402 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
403 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
404 ip6stat.ip6s_badscope++;
405 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
406 goto bad;
407 }
408 #if 0
409 /*
410 * Reject packets with IPv4 compatible addresses (auto tunnel).
411 *
412 * The code forbids auto tunnel relay case in RFC1933 (the check is
413 * stronger than RFC1933). We may want to re-enable it if mech-xx
414 * is revised to forbid relaying case.
415 */
416 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
417 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
418 ip6stat.ip6s_badscope++;
419 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
420 goto bad;
421 }
422 #endif
423
424 /* drop packets if interface ID portion is already filled */
425 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
426 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) &&
427 ip6->ip6_src.s6_addr16[1]) {
428 ip6stat.ip6s_badscope++;
429 goto bad;
430 }
431 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) &&
432 ip6->ip6_dst.s6_addr16[1]) {
433 ip6stat.ip6s_badscope++;
434 goto bad;
435 }
436 }
437
438 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
439 ip6->ip6_src.s6_addr16[1]
440 = htons(m->m_pkthdr.rcvif->if_index);
441 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
442 ip6->ip6_dst.s6_addr16[1]
443 = htons(m->m_pkthdr.rcvif->if_index);
444
445 #if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */
446 /*
447 * We use rt->rt_ifp to determine if the address is ours or not.
448 * If rt_ifp is lo0, the address is ours.
449 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0,
450 * so any address under fe80::%lo0/64 will be mistakenly considered
451 * local. The special case is supplied to handle the case properly
452 * by actually looking at interface addresses
453 * (using in6ifa_ifpwithaddr).
454 */
455 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) &&
456 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) {
457 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) {
458 icmp6_error(m, ICMP6_DST_UNREACH,
459 ICMP6_DST_UNREACH_ADDR, 0);
460 /* m is already freed */
461 goto bad2;
462 }
463
464 ours = 1;
465 deliverifp = m->m_pkthdr.rcvif;
466 goto hbhcheck;
467 }
468 #endif
469
470 /*
471 * Multicast check
472 *
473 * WARNING! For general subnet proxying the interface hw will
474 * likely filter out the multicast solicitations, so
475 * the interface must be in promiscuous mode.
476 */
477 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
478 ours = 1;
479 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
480 deliverifp = m->m_pkthdr.rcvif;
481 goto hbhcheck;
482 }
483
484 /*
485 * Unicast check
486 */
487 switch (ip6_ours_check_algorithm) {
488 default:
489 /*
490 * XXX: I intentionally broke our indentation rule here,
491 * since this switch-case is just for measurement and
492 * therefore should soon be removed.
493 */
494 if (ip6_forward_rt.ro_rt != NULL &&
495 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) &&
496 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
497 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
498 ip6stat.ip6s_forward_cachehit++;
499 else {
500 struct sockaddr_in6 *dst6;
501
502 if (ip6_forward_rt.ro_rt) {
503 /* route is down or destination is different */
504 ip6stat.ip6s_forward_cachemiss++;
505 RTFREE(ip6_forward_rt.ro_rt);
506 ip6_forward_rt.ro_rt = 0;
507 }
508
509 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
510 dst6 = &ip6_forward_rt.ro_dst;
511 dst6->sin6_len = sizeof(struct sockaddr_in6);
512 dst6->sin6_family = AF_INET6;
513 dst6->sin6_addr = ip6->ip6_dst;
514
515 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING);
516 }
517
518 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
519
520 /*
521 * Accept the packet if the forwarding interface to the destination
522 * according to the routing table is the loopback interface,
523 * unless the associated route has a gateway.
524 * Note that this approach causes to accept a packet if there is a
525 * route to the loopback interface for the destination of the packet.
526 * But we think it's even useful in some situations, e.g. when using
527 * a special daemon which wants to intercept the packet.
528 *
529 * XXX: some OSes automatically make a cloned route for the destination
530 * of an outgoing packet. If the outgoing interface of the packet
531 * is a loopback one, the kernel would consider the packet to be
532 * accepted, even if we have no such address assinged on the interface.
533 * We check the cloned flag of the route entry to reject such cases,
534 * assuming that route entries for our own addresses are not made by
535 * cloning (it should be true because in6_addloop explicitly installs
536 * the host route). However, we might have to do an explicit check
537 * while it would be less efficient. Or, should we rather install a
538 * reject route for such a case?
539 */
540 if (ip6_forward_rt.ro_rt &&
541 (ip6_forward_rt.ro_rt->rt_flags &
542 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
543 #ifdef RTF_WASCLONED
544 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
545 #endif
546 #ifdef RTF_CLONED
547 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
548 #endif
549 #if 0
550 /*
551 * The check below is redundant since the comparison of
552 * the destination and the key of the rtentry has
553 * already done through looking up the routing table.
554 */
555 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
556 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
557 #endif
558 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
559 struct in6_ifaddr *ia6 =
560 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
561
562 /*
563 * record address information into m_aux.
564 */
565 ip6_setdstifaddr(m, ia6);
566
567 /*
568 * packets to a tentative, duplicated, or somehow invalid
569 * address must not be accepted.
570 */
571 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
572 /* this address is ready */
573 ours = 1;
574 deliverifp = ia6->ia_ifp; /* correct? */
575 /* Count the packet in the ip address stats */
576 IFA_STAT_INC(&ia6->ia_ifa, ipackets, 1);
577 IFA_STAT_INC(&ia6->ia_ifa, ibytes, m->m_pkthdr.len);
578 goto hbhcheck;
579 } else {
580 /* address is not ready, so discard the packet. */
581 nd6log((LOG_INFO,
582 "ip6_input: packet to an unready address %s->%s\n",
583 ip6_sprintf(&ip6->ip6_src),
584 ip6_sprintf(&ip6->ip6_dst)));
585
586 goto bad;
587 }
588 }
589 } /* XXX indentation (see above) */
590
591 /*
592 * FAITH(Firewall Aided Internet Translator)
593 */
594 if (ip6_keepfaith) {
595 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
596 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
597 /* XXX do we need more sanity checks? */
598 ours = 1;
599 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
600 goto hbhcheck;
601 }
602 }
603
604 /*
605 * Now there is no reason to process the packet if it's not our own
606 * and we're not a router.
607 */
608 if (!ip6_forwarding) {
609 ip6stat.ip6s_cantforward++;
610 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
611 goto bad;
612 }
613
614 hbhcheck:
615 /*
616 * record address information into m_aux, if we don't have one yet.
617 * note that we are unable to record it, if the address is not listed
618 * as our interface address (e.g. multicast addresses, addresses
619 * within FAITH prefixes and such).
620 */
621 if (deliverifp && !ip6_getdstifaddr(m)) {
622 struct in6_ifaddr *ia6;
623
624 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
625 if (ia6) {
626 if (!ip6_setdstifaddr(m, ia6)) {
627 /*
628 * XXX maybe we should drop the packet here,
629 * as we could not provide enough information
630 * to the upper layers.
631 */
632 }
633 }
634 }
635
636 /*
637 * Process Hop-by-Hop options header if it's contained.
638 * m may be modified in ip6_hopopts_input().
639 * If a JumboPayload option is included, plen will also be modified.
640 */
641 plen = (u_int32_t)ntohs(ip6->ip6_plen);
642 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
643 struct ip6_hbh *hbh;
644
645 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
646 #if 0 /*touches NULL pointer*/
647 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
648 #endif
649 goto bad2; /* m have already been freed */
650 }
651
652 /* adjust pointer */
653 ip6 = mtod(m, struct ip6_hdr *);
654
655 /*
656 * if the payload length field is 0 and the next header field
657 * indicates Hop-by-Hop Options header, then a Jumbo Payload
658 * option MUST be included.
659 */
660 if (ip6->ip6_plen == 0 && plen == 0) {
661 /*
662 * Note that if a valid jumbo payload option is
663 * contained, ip6_hoptops_input() must set a valid
664 * (non-zero) payload length to the variable plen.
665 */
666 ip6stat.ip6s_badoptions++;
667 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
668 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
669 icmp6_error(m, ICMP6_PARAM_PROB,
670 ICMP6_PARAMPROB_HEADER,
671 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
672 goto bad2;
673 }
674 #ifndef PULLDOWN_TEST
675 /* ip6_hopopts_input() ensures that mbuf is contiguous */
676 hbh = (struct ip6_hbh *)(ip6 + 1);
677 #else
678 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
679 sizeof(struct ip6_hbh));
680 if (hbh == NULL) {
681 ip6stat.ip6s_tooshort++;
682 goto bad2;
683 }
684 #endif
685 nxt = hbh->ip6h_nxt;
686
687 /*
688 * If we are acting as a router and the packet contains a
689 * router alert option, see if we know the option value.
690 * Currently, we only support the option value for MLD, in which
691 * case we should pass the packet to the multicast routing
692 * daemon.
693 */
694 if (rtalert != ~0 && ip6_forwarding) {
695 switch (rtalert) {
696 case IP6OPT_RTALERT_MLD:
697 ours = 1;
698 break;
699 default:
700 /*
701 * RFC2711 requires unrecognized values must be
702 * silently ignored.
703 */
704 break;
705 }
706 }
707 } else
708 nxt = ip6->ip6_nxt;
709
710 /*
711 * Check that the amount of data in the buffers
712 * is as at least much as the IPv6 header would have us expect.
713 * Trim mbufs if longer than we expect.
714 * Drop packet if shorter than we expect.
715 */
716 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
717 ip6stat.ip6s_tooshort++;
718 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
719 goto bad;
720 }
721 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
722 if (m->m_len == m->m_pkthdr.len) {
723 m->m_len = sizeof(struct ip6_hdr) + plen;
724 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
725 } else
726 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
727 }
728
729 /*
730 * Forward if desirable.
731 */
732 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
733 /*
734 * If we are acting as a multicast router, all
735 * incoming multicast packets are passed to the
736 * kernel-level multicast forwarding function.
737 * The packet is returned (relatively) intact; if
738 * ip6_mforward() returns a non-zero value, the packet
739 * must be discarded, else it may be accepted below.
740 */
741 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
742 ip6stat.ip6s_cantforward++;
743 goto bad;
744 }
745 if (!ours)
746 goto bad;
747 } else if (!ours) {
748 ip6_forward(m, srcrt);
749 goto bad2;
750 }
751
752 ip6 = mtod(m, struct ip6_hdr *);
753
754 /*
755 * Malicious party may be able to use IPv4 mapped addr to confuse
756 * tcp/udp stack and bypass security checks (act as if it was from
757 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
758 *
759 * For SIIT end node behavior, you may want to disable the check.
760 * However, you will become vulnerable to attacks using IPv4 mapped
761 * source.
762 */
763 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
764 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
765 ip6stat.ip6s_badscope++;
766 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
767 goto bad;
768 }
769
770 /*
771 * Tell launch routine the next header
772 */
773 ip6stat.ip6s_delivered++;
774 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
775 nest = 0;
776
777 rh_present = 0;
778 while (nxt != IPPROTO_DONE) {
779 struct protosw *sw6;
780
781 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
782 ip6stat.ip6s_toomanyhdr++;
783 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
784 goto bad;
785 }
786
787 /*
788 * protection against faulty packet - there should be
789 * more sanity checks in header chain processing.
790 */
791 if (m->m_pkthdr.len < off) {
792 ip6stat.ip6s_tooshort++;
793 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
794 goto bad;
795 }
796
797 #if 0
798 /*
799 * do we need to do it for every header? yeah, other
800 * functions can play with it (like re-allocate and copy).
801 */
802 mhist = ip6_addaux(m);
803 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) {
804 hist = mtod(mhist, caddr_t) + mhist->m_len;
805 bcopy(&nxt, hist, sizeof(nxt));
806 mhist->m_len += sizeof(nxt);
807 } else {
808 ip6stat.ip6s_toomanyhdr++;
809 goto bad;
810 }
811 #endif
812
813 if (nxt == IPPROTO_ROUTING) {
814 if (rh_present++) {
815 in6_ifstat_inc(m->m_pkthdr.rcvif,
816 ifs6_in_hdrerr);
817 ip6stat.ip6s_badoptions++;
818 goto bad;
819 }
820 }
821
822 sw6 = &inet6sw[ip6_protox[nxt]];
823 #ifdef IPSEC
824 /*
825 * enforce IPsec policy checking if we are seeing last header.
826 * note that we do not visit this with protocols with pcb layer
827 * code - like udp/tcp/raw ip.
828 */
829 if ((sw6->pr_flags & PR_LASTHDR) && ipsec6_in_reject(m, NULL)) {
830 ipsec6stat.in_polvio++;
831 goto bad;
832 }
833 #endif
834 /*
835 * If this is a terminal header forward to the port, otherwise
836 * process synchronously for more headers.
837 */
838 if (sw6->pr_flags & PR_LASTHDR) {
839 struct netmsg_packet *pmsg;
840 lwkt_port_t port;
841
842 port = netisr_cpuport(0); /* XXX */
843 KKASSERT(port != NULL);
844 pmsg = &m->m_hdr.mh_netmsg;
845 netmsg_init(&pmsg->base, NULL,
846 &netisr_apanic_rport,
847 0, transport6_processing_handler);
848 pmsg->nm_packet = m;
849 pmsg->nm_nxt = nxt;
850 pmsg->base.lmsg.u.ms_result = off;
851 lwkt_sendmsg(port, &pmsg->base.lmsg);
852 /* done with m */
853 nxt = IPPROTO_DONE;
854 } else {
855 nxt = sw6->pr_input(&m, &off, nxt);
856 }
857 }
858 goto bad2;
859 bad:
860 m_freem(m);
861 bad2:
862 ;
863 /* msg was embedded in the mbuf, do not reply! */
864 }
865
866 /*
867 * We have to call the pr_input() function from the correct protocol
868 * thread. The sw6->pr_soport() request at the end of ip6_input()
869 * returns the port and we forward a netmsg to the port to execute
870 * this function.
871 */
872 static void
873 transport6_processing_handler(netmsg_t netmsg)
874 {
875 struct netmsg_packet *pmsg = (struct netmsg_packet *)netmsg;
876 struct protosw *sw6;
877 int hlen;
878 int nxt;
879
880 sw6 = &inet6sw[ip6_protox[pmsg->nm_nxt]];
881 hlen = pmsg->base.lmsg.u.ms_result;
882
883 nxt = sw6->pr_input(&pmsg->nm_packet, &hlen, pmsg->nm_nxt);
884 KKASSERT(nxt == IPPROTO_DONE);
885 /* netmsg was embedded in the mbuf, do not reply! */
886 }
887
888 /*
889 * set/grab in6_ifaddr correspond to IPv6 destination address.
890 * XXX backward compatibility wrapper
891 */
892 static struct ip6aux *
893 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
894 {
895 struct ip6aux *n;
896
897 n = ip6_addaux(m);
898 if (n)
899 n->ip6a_dstia6 = ia6;
900 return n; /* NULL if failed to set */
901 }
902
903 struct in6_ifaddr *
904 ip6_getdstifaddr(struct mbuf *m)
905 {
906 struct ip6aux *n;
907
908 n = ip6_findaux(m);
909 if (n)
910 return n->ip6a_dstia6;
911 else
912 return NULL;
913 }
914
915 /*
916 * Hop-by-Hop options header processing. If a valid jumbo payload option is
917 * included, the real payload length will be stored in plenp.
918 */
919 static int
920 ip6_hopopts_input(u_int32_t *plenp,
921 u_int32_t *rtalertp,/* XXX: should be stored more smart way */
922 struct mbuf **mp,
923 int *offp)
924 {
925 struct mbuf *m = *mp;
926 int off = *offp, hbhlen;
927 struct ip6_hbh *hbh;
928
929 /* validation of the length of the header */
930 #ifndef PULLDOWN_TEST
931 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
932 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
933 hbhlen = (hbh->ip6h_len + 1) << 3;
934
935 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
936 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
937 #else
938 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
939 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
940 if (hbh == NULL) {
941 ip6stat.ip6s_tooshort++;
942 return -1;
943 }
944 hbhlen = (hbh->ip6h_len + 1) << 3;
945 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
946 hbhlen);
947 if (hbh == NULL) {
948 ip6stat.ip6s_tooshort++;
949 return -1;
950 }
951 #endif
952 off += hbhlen;
953 hbhlen -= sizeof(struct ip6_hbh);
954
955 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
956 hbhlen, rtalertp, plenp) < 0)
957 return (-1);
958
959 *offp = off;
960 *mp = m;
961 return (0);
962 }
963
964 /*
965 * Search header for all Hop-by-hop options and process each option.
966 * This function is separate from ip6_hopopts_input() in order to
967 * handle a case where the sending node itself process its hop-by-hop
968 * options header. In such a case, the function is called from ip6_output().
969 *
970 * The function assumes that hbh header is located right after the IPv6 header
971 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
972 * opthead + hbhlen is located in continuous memory region.
973 */
974 int
975 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
976 u_int32_t *rtalertp, u_int32_t *plenp)
977 {
978 struct ip6_hdr *ip6;
979 int optlen = 0;
980 u_int8_t *opt = opthead;
981 u_int16_t rtalert_val;
982 u_int32_t jumboplen;
983 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
984
985 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
986 switch (*opt) {
987 case IP6OPT_PAD1:
988 optlen = 1;
989 break;
990 case IP6OPT_PADN:
991 if (hbhlen < IP6OPT_MINLEN) {
992 ip6stat.ip6s_toosmall++;
993 goto bad;
994 }
995 optlen = *(opt + 1) + 2;
996 break;
997 case IP6OPT_RTALERT:
998 /* XXX may need check for alignment */
999 if (hbhlen < IP6OPT_RTALERT_LEN) {
1000 ip6stat.ip6s_toosmall++;
1001 goto bad;
1002 }
1003 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
1004 /* XXX stat */
1005 icmp6_error(m, ICMP6_PARAM_PROB,
1006 ICMP6_PARAMPROB_HEADER,
1007 erroff + opt + 1 - opthead);
1008 return (-1);
1009 }
1010 optlen = IP6OPT_RTALERT_LEN;
1011 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
1012 *rtalertp = ntohs(rtalert_val);
1013 break;
1014 case IP6OPT_JUMBO:
1015 /* XXX may need check for alignment */
1016 if (hbhlen < IP6OPT_JUMBO_LEN) {
1017 ip6stat.ip6s_toosmall++;
1018 goto bad;
1019 }
1020 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
1021 /* XXX stat */
1022 icmp6_error(m, ICMP6_PARAM_PROB,
1023 ICMP6_PARAMPROB_HEADER,
1024 erroff + opt + 1 - opthead);
1025 return (-1);
1026 }
1027 optlen = IP6OPT_JUMBO_LEN;
1028
1029 /*
1030 * IPv6 packets that have non 0 payload length
1031 * must not contain a jumbo payload option.
1032 */
1033 ip6 = mtod(m, struct ip6_hdr *);
1034 if (ip6->ip6_plen) {
1035 ip6stat.ip6s_badoptions++;
1036 icmp6_error(m, ICMP6_PARAM_PROB,
1037 ICMP6_PARAMPROB_HEADER,
1038 erroff + opt - opthead);
1039 return (-1);
1040 }
1041
1042 /*
1043 * We may see jumbolen in unaligned location, so
1044 * we'd need to perform bcopy().
1045 */
1046 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1047 jumboplen = (u_int32_t)htonl(jumboplen);
1048
1049 #if 1
1050 /*
1051 * if there are multiple jumbo payload options,
1052 * *plenp will be non-zero and the packet will be
1053 * rejected.
1054 * the behavior may need some debate in ipngwg -
1055 * multiple options does not make sense, however,
1056 * there's no explicit mention in specification.
1057 */
1058 if (*plenp != 0) {
1059 ip6stat.ip6s_badoptions++;
1060 icmp6_error(m, ICMP6_PARAM_PROB,
1061 ICMP6_PARAMPROB_HEADER,
1062 erroff + opt + 2 - opthead);
1063 return (-1);
1064 }
1065 #endif
1066
1067 /*
1068 * jumbo payload length must be larger than 65535.
1069 */
1070 if (jumboplen <= IPV6_MAXPACKET) {
1071 ip6stat.ip6s_badoptions++;
1072 icmp6_error(m, ICMP6_PARAM_PROB,
1073 ICMP6_PARAMPROB_HEADER,
1074 erroff + opt + 2 - opthead);
1075 return (-1);
1076 }
1077 *plenp = jumboplen;
1078
1079 break;
1080 default: /* unknown option */
1081 if (hbhlen < IP6OPT_MINLEN) {
1082 ip6stat.ip6s_toosmall++;
1083 goto bad;
1084 }
1085 optlen = ip6_unknown_opt(opt, m,
1086 erroff + opt - opthead);
1087 if (optlen == -1)
1088 return (-1);
1089 optlen += 2;
1090 break;
1091 }
1092 }
1093
1094 return (0);
1095
1096 bad:
1097 m_freem(m);
1098 return (-1);
1099 }
1100
1101 /*
1102 * Unknown option processing.
1103 * The third argument `off' is the offset from the IPv6 header to the option,
1104 * which is necessary if the IPv6 header the and option header and IPv6 header
1105 * is not continuous in order to return an ICMPv6 error.
1106 */
1107 int
1108 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1109 {
1110 struct ip6_hdr *ip6;
1111
1112 switch (IP6OPT_TYPE(*optp)) {
1113 case IP6OPT_TYPE_SKIP: /* ignore the option */
1114 return ((int)*(optp + 1));
1115 case IP6OPT_TYPE_DISCARD: /* silently discard */
1116 m_freem(m);
1117 return (-1);
1118 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1119 ip6stat.ip6s_badoptions++;
1120 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1121 return (-1);
1122 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1123 ip6stat.ip6s_badoptions++;
1124 ip6 = mtod(m, struct ip6_hdr *);
1125 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1126 (m->m_flags & (M_BCAST|M_MCAST)))
1127 m_freem(m);
1128 else
1129 icmp6_error(m, ICMP6_PARAM_PROB,
1130 ICMP6_PARAMPROB_OPTION, off);
1131 return (-1);
1132 }
1133
1134 m_freem(m); /* XXX: NOTREACHED */
1135 return (-1);
1136 }
1137
1138 /*
1139 * Create the "control" list for this pcb.
1140 * The function will not modify mbuf chain at all.
1141 *
1142 * with KAME mbuf chain restriction:
1143 * The routine will be called from upper layer handlers like tcp6_input().
1144 * Thus the routine assumes that the caller (tcp6_input) have already
1145 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1146 * very first mbuf on the mbuf chain.
1147 */
1148 void
1149 ip6_savecontrol(struct inpcb *in6p, struct mbuf **mp, struct ip6_hdr *ip6,
1150 struct mbuf *m)
1151 {
1152 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
1153 struct thread *td = curthread; /* XXX */
1154 int privileged = 0;
1155
1156
1157 if (priv_check(td, PRIV_ROOT) == 0)
1158 privileged++;
1159
1160 #ifdef SO_TIMESTAMP
1161 if (in6p->in6p_socket->so_options & SO_TIMESTAMP) {
1162 struct timeval tv;
1163
1164 microtime(&tv);
1165 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1166 SCM_TIMESTAMP, SOL_SOCKET);
1167 if (*mp) {
1168 mp = &(*mp)->m_next;
1169 }
1170 }
1171 #endif
1172
1173 /* RFC 2292 sec. 5 */
1174 if (in6p->in6p_flags & IN6P_PKTINFO) {
1175 struct in6_pktinfo pi6;
1176 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1177 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr))
1178 pi6.ipi6_addr.s6_addr16[1] = 0;
1179 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif)
1180 ? m->m_pkthdr.rcvif->if_index
1181 : 0;
1182 *mp = sbcreatecontrol((caddr_t) &pi6,
1183 sizeof(struct in6_pktinfo), IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO),
1184 IPPROTO_IPV6);
1185 if (*mp)
1186 mp = &(*mp)->m_next;
1187 }
1188
1189 if (in6p->in6p_flags & IN6P_HOPLIMIT) {
1190 int hlim = ip6->ip6_hlim & 0xff;
1191 *mp = sbcreatecontrol((caddr_t) &hlim,
1192 sizeof(int), IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6);
1193 if (*mp)
1194 mp = &(*mp)->m_next;
1195 }
1196
1197 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
1198 u_int32_t flowinfo;
1199 int tclass;
1200
1201 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1202 flowinfo >>= 20;
1203
1204 tclass = flowinfo & 0xff;
1205 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
1206 IPV6_TCLASS, IPPROTO_IPV6);
1207 if (*mp)
1208 mp = &(*mp)->m_next;
1209 }
1210
1211 /*
1212 * IPV6_HOPOPTS socket option. We require super-user privilege
1213 * for the option, but it might be too strict, since there might
1214 * be some hop-by-hop options which can be returned to normal user.
1215 * See RFC 2292 section 6.
1216 */
1217 if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) {
1218 /*
1219 * Check if a hop-by-hop options header is contatined in the
1220 * received packet, and if so, store the options as ancillary
1221 * data. Note that a hop-by-hop options header must be
1222 * just after the IPv6 header, which fact is assured through
1223 * the IPv6 input processing.
1224 */
1225 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1226 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1227 struct ip6_hbh *hbh;
1228 int hbhlen = 0;
1229 #ifdef PULLDOWN_TEST
1230 struct mbuf *ext;
1231 #endif
1232
1233 #ifndef PULLDOWN_TEST
1234 hbh = (struct ip6_hbh *)(ip6 + 1);
1235 hbhlen = (hbh->ip6h_len + 1) << 3;
1236 #else
1237 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1238 ip6->ip6_nxt);
1239 if (ext == NULL) {
1240 ip6stat.ip6s_tooshort++;
1241 return;
1242 }
1243 hbh = mtod(ext, struct ip6_hbh *);
1244 hbhlen = (hbh->ip6h_len + 1) << 3;
1245 if (hbhlen != ext->m_len) {
1246 m_freem(ext);
1247 ip6stat.ip6s_tooshort++;
1248 return;
1249 }
1250 #endif
1251
1252 /*
1253 * XXX: We copy whole the header even if a jumbo
1254 * payload option is included, which option is to
1255 * be removed before returning in the RFC 2292.
1256 * Note: this constraint is removed in 2292bis.
1257 */
1258 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1259 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS), IPPROTO_IPV6);
1260 if (*mp)
1261 mp = &(*mp)->m_next;
1262 #ifdef PULLDOWN_TEST
1263 m_freem(ext);
1264 #endif
1265 }
1266 }
1267
1268 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */
1269 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
1270 int proto, off, nxt;
1271
1272 /*
1273 * go through the header chain to see if a routing header is
1274 * contained in the packet. We need this information to store
1275 * destination options headers (if any) properly.
1276 * XXX: performance issue. We should record this info when
1277 * processing extension headers in incoming routine.
1278 * (todo) use m_aux?
1279 */
1280 proto = IPPROTO_IPV6;
1281 off = 0;
1282 nxt = -1;
1283 while (1) {
1284 int newoff;
1285
1286 newoff = ip6_nexthdr(m, off, proto, &nxt);
1287 if (newoff < 0)
1288 break;
1289 if (newoff < off) /* invalid, check for safety */
1290 break;
1291 if ((proto = nxt) == IPPROTO_ROUTING)
1292 break;
1293 off = newoff;
1294 }
1295 }
1296
1297 if ((in6p->in6p_flags &
1298 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
1299 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1300 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1301
1302 /*
1303 * Search for destination options headers or routing
1304 * header(s) through the header chain, and stores each
1305 * header as ancillary data.
1306 * Note that the order of the headers remains in
1307 * the chain of ancillary data.
1308 */
1309 while (1) { /* is explicit loop prevention necessary? */
1310 struct ip6_ext *ip6e = NULL;
1311 int elen;
1312 #ifdef PULLDOWN_TEST
1313 struct mbuf *ext = NULL;
1314 #endif
1315
1316 /*
1317 * if it is not an extension header, don't try to
1318 * pull it from the chain.
1319 */
1320 switch (nxt) {
1321 case IPPROTO_DSTOPTS:
1322 case IPPROTO_ROUTING:
1323 case IPPROTO_HOPOPTS:
1324 case IPPROTO_AH: /* is it possible? */
1325 break;
1326 default:
1327 goto loopend;
1328 }
1329
1330 #ifndef PULLDOWN_TEST
1331 if (off + sizeof(*ip6e) > m->m_len)
1332 goto loopend;
1333 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1334 if (nxt == IPPROTO_AH)
1335 elen = (ip6e->ip6e_len + 2) << 2;
1336 else
1337 elen = (ip6e->ip6e_len + 1) << 3;
1338 if (off + elen > m->m_len)
1339 goto loopend;
1340 #else
1341 ext = ip6_pullexthdr(m, off, nxt);
1342 if (ext == NULL) {
1343 ip6stat.ip6s_tooshort++;
1344 return;
1345 }
1346 ip6e = mtod(ext, struct ip6_ext *);
1347 if (nxt == IPPROTO_AH)
1348 elen = (ip6e->ip6e_len + 2) << 2;
1349 else
1350 elen = (ip6e->ip6e_len + 1) << 3;
1351 if (elen != ext->m_len) {
1352 m_freem(ext);
1353 ip6stat.ip6s_tooshort++;
1354 return;
1355 }
1356 #endif
1357
1358 switch (nxt) {
1359 case IPPROTO_DSTOPTS:
1360 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0)
1361 break;
1362
1363 /*
1364 * We also require super-user privilege for
1365 * the option.
1366 * See the comments on IN6_HOPOPTS.
1367 */
1368 if (!privileged)
1369 break;
1370
1371 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1372 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1373 IPPROTO_IPV6);
1374 if (*mp)
1375 mp = &(*mp)->m_next;
1376 break;
1377 case IPPROTO_ROUTING:
1378 if (!(in6p->in6p_flags & IN6P_RTHDR))
1379 break;
1380
1381 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1382 IS2292(IPV6_2292RTHDR, IPV6_RTHDR),
1383 IPPROTO_IPV6);
1384 if (*mp)
1385 mp = &(*mp)->m_next;
1386 break;
1387 case IPPROTO_HOPOPTS:
1388 case IPPROTO_AH: /* is it possible? */
1389 break;
1390
1391 default:
1392 /*
1393 * other cases have been filtered in the above.
1394 * none will visit this case. here we supply
1395 * the code just in case (nxt overwritten or
1396 * other cases).
1397 */
1398 #ifdef PULLDOWN_TEST
1399 m_freem(ext);
1400 #endif
1401 goto loopend;
1402
1403 }
1404
1405 /* proceed with the next header. */
1406 off += elen;
1407 nxt = ip6e->ip6e_nxt;
1408 ip6e = NULL;
1409 #ifdef PULLDOWN_TEST
1410 m_freem(ext);
1411 ext = NULL;
1412 #endif
1413 }
1414 loopend:
1415 ;
1416 }
1417 #undef IS2292
1418 }
1419
1420 void
1421 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
1422 {
1423 struct socket *so;
1424 struct mbuf *m_mtu;
1425 struct ip6_mtuinfo mtuctl;
1426
1427 so = in6p->inp_socket;
1428
1429 if (mtu == NULL)
1430 return;
1431
1432 #ifdef DIAGNOSTIC
1433 if (so == NULL) /* I believe this is impossible */
1434 panic("ip6_notify_pmtu: socket is NULL");
1435 #endif
1436
1437 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
1438 mtuctl.ip6m_mtu = *mtu;
1439 mtuctl.ip6m_addr = *dst;
1440
1441 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1442 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1443 return;
1444
1445 lwkt_gettoken(&so->so_rcv.ssb_token);
1446 if (sbappendaddr(&so->so_rcv.sb, (struct sockaddr *)dst, NULL, m_mtu)
1447 == 0) {
1448 m_freem(m_mtu);
1449 /* XXX: should count statistics */
1450 } else {
1451 sorwakeup(so);
1452 }
1453 lwkt_reltoken(&so->so_rcv.ssb_token);
1454 }
1455
1456 #ifdef PULLDOWN_TEST
1457 /*
1458 * pull single extension header from mbuf chain. returns single mbuf that
1459 * contains the result, or NULL on error.
1460 */
1461 static struct mbuf *
1462 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1463 {
1464 struct ip6_ext ip6e;
1465 size_t elen;
1466 struct mbuf *n;
1467
1468 #ifdef DIAGNOSTIC
1469 switch (nxt) {
1470 case IPPROTO_DSTOPTS:
1471 case IPPROTO_ROUTING:
1472 case IPPROTO_HOPOPTS:
1473 case IPPROTO_AH: /* is it possible? */
1474 break;
1475 default:
1476 kprintf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1477 }
1478 #endif
1479
1480 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1481 if (nxt == IPPROTO_AH)
1482 elen = (ip6e.ip6e_len + 2) << 2;
1483 else
1484 elen = (ip6e.ip6e_len + 1) << 3;
1485
1486 n = m_getb(elen, MB_DONTWAIT, MT_DATA, 0);
1487 if (n == NULL)
1488 return NULL;
1489 n->m_len = 0;
1490
1491 if (elen >= M_TRAILINGSPACE(n)) {
1492 m_free(n);
1493 return NULL;
1494 }
1495
1496 m_copydata(m, off, elen, mtod(n, caddr_t));
1497 n->m_len = elen;
1498 return n;
1499 }
1500 #endif
1501
1502 /*
1503 * Get pointer to the previous header followed by the header
1504 * currently processed.
1505 * XXX: This function supposes that
1506 * M includes all headers,
1507 * the next header field and the header length field of each header
1508 * are valid, and
1509 * the sum of each header length equals to OFF.
1510 * Because of these assumptions, this function must be called very
1511 * carefully. Moreover, it will not be used in the near future when
1512 * we develop `neater' mechanism to process extension headers.
1513 */
1514 char *
1515 ip6_get_prevhdr(struct mbuf *m, int off)
1516 {
1517 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1518
1519 if (off == sizeof(struct ip6_hdr))
1520 return (&ip6->ip6_nxt);
1521 else {
1522 int len, nxt;
1523 struct ip6_ext *ip6e = NULL;
1524
1525 nxt = ip6->ip6_nxt;
1526 len = sizeof(struct ip6_hdr);
1527 while (len < off) {
1528 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1529
1530 switch (nxt) {
1531 case IPPROTO_FRAGMENT:
1532 len += sizeof(struct ip6_frag);
1533 break;
1534 case IPPROTO_AH:
1535 len += (ip6e->ip6e_len + 2) << 2;
1536 break;
1537 default:
1538 len += (ip6e->ip6e_len + 1) << 3;
1539 break;
1540 }
1541 nxt = ip6e->ip6e_nxt;
1542 }
1543 if (ip6e)
1544 return (&ip6e->ip6e_nxt);
1545 else
1546 return NULL;
1547 }
1548 }
1549
1550 /*
1551 * get next header offset. m will be retained.
1552 */
1553 int
1554 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1555 {
1556 struct ip6_hdr ip6;
1557 struct ip6_ext ip6e;
1558 struct ip6_frag fh;
1559
1560 /* just in case */
1561 if (m == NULL)
1562 panic("ip6_nexthdr: m == NULL");
1563 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1564 return -1;
1565
1566 switch (proto) {
1567 case IPPROTO_IPV6:
1568 if (m->m_pkthdr.len < off + sizeof(ip6))
1569 return -1;
1570 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1571 if (nxtp)
1572 *nxtp = ip6.ip6_nxt;
1573 off += sizeof(ip6);
1574 return off;
1575
1576 case IPPROTO_FRAGMENT:
1577 /*
1578 * terminate parsing if it is not the first fragment,
1579 * it does not make sense to parse through it.
1580 */
1581 if (m->m_pkthdr.len < off + sizeof(fh))
1582 return -1;
1583 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1584 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1585 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1586 return -1;
1587 if (nxtp)
1588 *nxtp = fh.ip6f_nxt;
1589 off += sizeof(struct ip6_frag);
1590 return off;
1591
1592 case IPPROTO_AH:
1593 if (m->m_pkthdr.len < off + sizeof(ip6e))
1594 return -1;
1595 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1596 if (nxtp)
1597 *nxtp = ip6e.ip6e_nxt;
1598 off += (ip6e.ip6e_len + 2) << 2;
1599 return off;
1600
1601 case IPPROTO_HOPOPTS:
1602 case IPPROTO_ROUTING:
1603 case IPPROTO_DSTOPTS:
1604 if (m->m_pkthdr.len < off + sizeof(ip6e))
1605 return -1;
1606 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1607 if (nxtp)
1608 *nxtp = ip6e.ip6e_nxt;
1609 off += (ip6e.ip6e_len + 1) << 3;
1610 return off;
1611
1612 case IPPROTO_NONE:
1613 case IPPROTO_ESP:
1614 case IPPROTO_IPCOMP:
1615 /* give up */
1616 return -1;
1617
1618 default:
1619 return -1;
1620 }
1621
1622 return -1;
1623 }
1624
1625 /*
1626 * get offset for the last header in the chain. m will be kept untainted.
1627 */
1628 int
1629 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1630 {
1631 int newoff;
1632 int nxt;
1633
1634 if (!nxtp) {
1635 nxt = -1;
1636 nxtp = &nxt;
1637 }
1638 while (1) {
1639 newoff = ip6_nexthdr(m, off, proto, nxtp);
1640 if (newoff < 0)
1641 return off;
1642 else if (newoff < off)
1643 return -1; /* invalid */
1644 else if (newoff == off)
1645 return newoff;
1646
1647 off = newoff;
1648 proto = *nxtp;
1649 }
1650 }
1651
1652 struct ip6aux *
1653 ip6_addaux(struct mbuf *m)
1654 {
1655 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1656 if (!tag) {
1657 tag = m_tag_get(PACKET_TAG_IPV6_INPUT,
1658 sizeof (struct ip6aux),
1659 MB_DONTWAIT);
1660 if (tag)
1661 m_tag_prepend(m, tag);
1662 }
1663 if (tag)
1664 bzero(m_tag_data(tag), sizeof (struct ip6aux));
1665 return tag ? (struct ip6aux *)m_tag_data(tag) : NULL;
1666 }
1667
1668 struct ip6aux *
1669 ip6_findaux(struct mbuf *m)
1670 {
1671 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1672 return tag ? (struct ip6aux*)(tag+1) : NULL;
1673 }
1674
1675 void
1676 ip6_delaux(struct mbuf *m)
1677 {
1678 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1679 if (tag)
1680 m_tag_delete(m, tag);
1681 }
1682
1683 /*
1684 * System control for IP6
1685 */
1686
1687 u_char inet6ctlerrmap[PRC_NCMDS] = {
1688 0, 0, 0, 0,
1689 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1690 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1691 EMSGSIZE, EHOSTUNREACH, 0, 0,
1692 0, 0, 0, 0,
1693 ENOPROTOOPT
1694 };
Cache object: 689d03eaafbaffd3856567ea977b4ebb
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