1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $
30 */
31
32 /*-
33 * Copyright (c) 1982, 1986, 1988, 1993
34 * The Regents of the University of California. All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 * 4. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
61 */
62
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipfw.h"
69 #include "opt_ipsec.h"
70 #include "opt_kdtrace.h"
71 #include "opt_route.h"
72
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/malloc.h>
76 #include <sys/mbuf.h>
77 #include <sys/proc.h>
78 #include <sys/domain.h>
79 #include <sys/protosw.h>
80 #include <sys/sdt.h>
81 #include <sys/socket.h>
82 #include <sys/socketvar.h>
83 #include <sys/errno.h>
84 #include <sys/time.h>
85 #include <sys/kernel.h>
86 #include <sys/syslog.h>
87
88 #include <net/if.h>
89 #include <net/if_types.h>
90 #include <net/if_dl.h>
91 #include <net/route.h>
92 #include <net/netisr.h>
93 #include <net/pfil.h>
94 #include <net/vnet.h>
95
96 #include <netinet/in.h>
97 #include <netinet/in_kdtrace.h>
98 #include <netinet/ip_var.h>
99 #include <netinet/in_systm.h>
100 #include <net/if_llatbl.h>
101 #ifdef INET
102 #include <netinet/ip.h>
103 #include <netinet/ip_icmp.h>
104 #endif /* INET */
105 #include <netinet/ip6.h>
106 #include <netinet6/in6_var.h>
107 #include <netinet6/ip6_var.h>
108 #include <netinet/in_pcb.h>
109 #include <netinet/icmp6.h>
110 #include <netinet6/scope6_var.h>
111 #include <netinet6/in6_ifattach.h>
112 #include <netinet6/nd6.h>
113
114 #ifdef IPSEC
115 #include <netipsec/ipsec.h>
116 #include <netinet6/ip6_ipsec.h>
117 #include <netipsec/ipsec6.h>
118 #endif /* IPSEC */
119
120 #include <netinet6/ip6protosw.h>
121
122 extern struct domain inet6domain;
123
124 u_char ip6_protox[IPPROTO_MAX];
125 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
126 VNET_DEFINE(struct in6_ifaddrlisthead *, in6_ifaddrhashtbl);
127 VNET_DEFINE(u_long, in6_ifaddrhmask);
128
129 static struct netisr_handler ip6_nh = {
130 .nh_name = "ip6",
131 .nh_handler = ip6_input,
132 .nh_proto = NETISR_IPV6,
133 .nh_policy = NETISR_POLICY_FLOW,
134 };
135
136 VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch);
137 #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch)
138
139 VNET_DEFINE(struct pfil_head, inet6_pfil_hook);
140
141 VNET_PCPUSTAT_DEFINE(struct ip6stat, ip6stat);
142 VNET_PCPUSTAT_SYSINIT(ip6stat);
143 #ifdef VIMAGE
144 VNET_PCPUSTAT_SYSUNINIT(ip6stat);
145 #endif /* VIMAGE */
146
147 struct rwlock in6_ifaddr_lock;
148 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
149
150 static void ip6_init2(void *);
151 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *);
152 static struct ip6aux *ip6_addaux(struct mbuf *);
153 static struct ip6aux *ip6_findaux(struct mbuf *m);
154 static void ip6_delaux (struct mbuf *);
155 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
156 #ifdef PULLDOWN_TEST
157 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
158 #endif
159
160 /*
161 * IP6 initialization: fill in IP6 protocol switch table.
162 * All protocols not implemented in kernel go to raw IP6 protocol handler.
163 */
164 void
ip6_init(void)165 ip6_init(void)
166 {
167 struct ip6protosw *pr;
168 int i;
169
170 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal",
171 &V_ip6_auto_linklocal);
172 TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv);
173 TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr);
174
175 TAILQ_INIT(&V_in6_ifaddrhead);
176 V_in6_ifaddrhashtbl = hashinit(IN6ADDR_NHASH, M_IFADDR,
177 &V_in6_ifaddrhmask);
178
179 /* Initialize packet filter hooks. */
180 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
181 V_inet6_pfil_hook.ph_af = AF_INET6;
182 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0)
183 printf("%s: WARNING: unable to register pfil hook, "
184 "error %d\n", __func__, i);
185
186 scope6_init();
187 addrsel_policy_init();
188 nd6_init();
189 frag6_init();
190
191 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
192
193 /* Skip global initialization stuff for non-default instances. */
194 if (!IS_DEFAULT_VNET(curvnet))
195 return;
196
197 #ifdef DIAGNOSTIC
198 if (sizeof(struct protosw) != sizeof(struct ip6protosw))
199 panic("sizeof(protosw) != sizeof(ip6protosw)");
200 #endif
201 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
202 if (pr == NULL)
203 panic("ip6_init");
204
205 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */
206 for (i = 0; i < IPPROTO_MAX; i++)
207 ip6_protox[i] = pr - inet6sw;
208 /*
209 * Cycle through IP protocols and put them into the appropriate place
210 * in ip6_protox[].
211 */
212 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
213 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
214 if (pr->pr_domain->dom_family == PF_INET6 &&
215 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
216 /* Be careful to only index valid IP protocols. */
217 if (pr->pr_protocol < IPPROTO_MAX)
218 ip6_protox[pr->pr_protocol] = pr - inet6sw;
219 }
220
221 netisr_register(&ip6_nh);
222 }
223
224 /*
225 * The protocol to be inserted into ip6_protox[] must be already registered
226 * in inet6sw[], either statically or through pf_proto_register().
227 */
228 int
ip6proto_register(short ip6proto)229 ip6proto_register(short ip6proto)
230 {
231 struct ip6protosw *pr;
232
233 /* Sanity checks. */
234 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
235 return (EPROTONOSUPPORT);
236
237 /*
238 * The protocol slot must not be occupied by another protocol
239 * already. An index pointing to IPPROTO_RAW is unused.
240 */
241 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
242 if (pr == NULL)
243 return (EPFNOSUPPORT);
244 if (ip6_protox[ip6proto] != pr - inet6sw) /* IPPROTO_RAW */
245 return (EEXIST);
246
247 /*
248 * Find the protocol position in inet6sw[] and set the index.
249 */
250 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
251 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) {
252 if (pr->pr_domain->dom_family == PF_INET6 &&
253 pr->pr_protocol && pr->pr_protocol == ip6proto) {
254 ip6_protox[pr->pr_protocol] = pr - inet6sw;
255 return (0);
256 }
257 }
258 return (EPROTONOSUPPORT);
259 }
260
261 int
ip6proto_unregister(short ip6proto)262 ip6proto_unregister(short ip6proto)
263 {
264 struct ip6protosw *pr;
265
266 /* Sanity checks. */
267 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
268 return (EPROTONOSUPPORT);
269
270 /* Check if the protocol was indeed registered. */
271 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
272 if (pr == NULL)
273 return (EPFNOSUPPORT);
274 if (ip6_protox[ip6proto] == pr - inet6sw) /* IPPROTO_RAW */
275 return (ENOENT);
276
277 /* Reset the protocol slot to IPPROTO_RAW. */
278 ip6_protox[ip6proto] = pr - inet6sw;
279 return (0);
280 }
281
282 #ifdef VIMAGE
283 void
ip6_destroy()284 ip6_destroy()
285 {
286 int i;
287
288 if ((i = pfil_head_unregister(&V_inet6_pfil_hook)) != 0)
289 printf("%s: WARNING: unable to unregister pfil hook, "
290 "error %d\n", __func__, i);
291 hashdestroy(V_in6_ifaddrhashtbl, M_IFADDR, V_in6_ifaddrhmask);
292 nd6_destroy();
293 callout_drain(&V_in6_tmpaddrtimer_ch);
294 }
295 #endif
296
297 static int
ip6_init2_vnet(const void * unused __unused)298 ip6_init2_vnet(const void *unused __unused)
299 {
300
301 /* nd6_timer_init */
302 callout_init(&V_nd6_timer_ch, 0);
303 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
304
305 /* timer for regeneranation of temporary addresses randomize ID */
306 callout_init(&V_in6_tmpaddrtimer_ch, 0);
307 callout_reset(&V_in6_tmpaddrtimer_ch,
308 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
309 V_ip6_temp_regen_advance) * hz,
310 in6_tmpaddrtimer, curvnet);
311
312 return (0);
313 }
314
315 static void
ip6_init2(void * dummy)316 ip6_init2(void *dummy)
317 {
318
319 ip6_init2_vnet(NULL);
320 }
321
322 /* cheat */
323 /* This must be after route_init(), which is now SI_ORDER_THIRD */
324 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
325
326 static int
ip6_input_hbh(struct mbuf * m,uint32_t * plen,uint32_t * rtalert,int * off,int * nxt,int * ours)327 ip6_input_hbh(struct mbuf *m, uint32_t *plen, uint32_t *rtalert, int *off,
328 int *nxt, int *ours)
329 {
330 struct ip6_hdr *ip6;
331 struct ip6_hbh *hbh;
332
333 if (ip6_hopopts_input(plen, rtalert, &m, off)) {
334 #if 0 /*touches NULL pointer*/
335 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
336 #endif
337 goto out; /* m have already been freed */
338 }
339
340 /* adjust pointer */
341 ip6 = mtod(m, struct ip6_hdr *);
342
343 /*
344 * if the payload length field is 0 and the next header field
345 * indicates Hop-by-Hop Options header, then a Jumbo Payload
346 * option MUST be included.
347 */
348 if (ip6->ip6_plen == 0 && *plen == 0) {
349 /*
350 * Note that if a valid jumbo payload option is
351 * contained, ip6_hopopts_input() must set a valid
352 * (non-zero) payload length to the variable plen.
353 */
354 IP6STAT_INC(ip6s_badoptions);
355 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
356 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
357 icmp6_error(m, ICMP6_PARAM_PROB,
358 ICMP6_PARAMPROB_HEADER,
359 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
360 goto out;
361 }
362 #ifndef PULLDOWN_TEST
363 /* ip6_hopopts_input() ensures that mbuf is contiguous */
364 hbh = (struct ip6_hbh *)(ip6 + 1);
365 #else
366 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
367 sizeof(struct ip6_hbh));
368 if (hbh == NULL) {
369 IP6STAT_INC(ip6s_tooshort);
370 goto out;
371 }
372 #endif
373 *nxt = hbh->ip6h_nxt;
374
375 /*
376 * If we are acting as a router and the packet contains a
377 * router alert option, see if we know the option value.
378 * Currently, we only support the option value for MLD, in which
379 * case we should pass the packet to the multicast routing
380 * daemon.
381 */
382 if (*rtalert != ~0) {
383 switch (*rtalert) {
384 case IP6OPT_RTALERT_MLD:
385 if (V_ip6_forwarding)
386 *ours = 1;
387 break;
388 default:
389 /*
390 * RFC2711 requires unrecognized values must be
391 * silently ignored.
392 */
393 break;
394 }
395 }
396
397 return (0);
398
399 out:
400 return (1);
401 }
402
403 void
ip6_input(struct mbuf * m)404 ip6_input(struct mbuf *m)
405 {
406 struct ip6_hdr *ip6;
407 int off = sizeof(struct ip6_hdr), nest;
408 u_int32_t plen;
409 u_int32_t rtalert = ~0;
410 int nxt, ours = 0;
411 struct ifnet *deliverifp = NULL, *ifp = NULL;
412 struct in6_addr odst;
413 struct route_in6 rin6;
414 int srcrt = 0;
415 struct llentry *lle = NULL;
416 struct sockaddr_in6 dst6, *dst;
417
418 bzero(&rin6, sizeof(struct route_in6));
419 #ifdef IPSEC
420 /*
421 * should the inner packet be considered authentic?
422 * see comment in ah4_input().
423 * NB: m cannot be NULL when passed to the input routine
424 */
425
426 m->m_flags &= ~M_AUTHIPHDR;
427 m->m_flags &= ~M_AUTHIPDGM;
428
429 #endif /* IPSEC */
430
431 /*
432 * make sure we don't have onion peering information into m_tag.
433 */
434 ip6_delaux(m);
435
436 if (m->m_flags & M_FASTFWD_OURS) {
437 /*
438 * Firewall changed destination to local.
439 */
440 m->m_flags &= ~M_FASTFWD_OURS;
441 ours = 1;
442 deliverifp = m->m_pkthdr.rcvif;
443 ip6 = mtod(m, struct ip6_hdr *);
444 goto hbhcheck;
445 }
446
447 /*
448 * mbuf statistics
449 */
450 if (m->m_flags & M_EXT) {
451 if (m->m_next)
452 IP6STAT_INC(ip6s_mext2m);
453 else
454 IP6STAT_INC(ip6s_mext1);
455 } else {
456 if (m->m_next) {
457 if (m->m_flags & M_LOOP) {
458 IP6STAT_INC(ip6s_m2m[V_loif->if_index]);
459 } else if (m->m_pkthdr.rcvif->if_index < IP6S_M2MMAX)
460 IP6STAT_INC(
461 ip6s_m2m[m->m_pkthdr.rcvif->if_index]);
462 else
463 IP6STAT_INC(ip6s_m2m[0]);
464 } else
465 IP6STAT_INC(ip6s_m1);
466 }
467
468 /* drop the packet if IPv6 operation is disabled on the IF */
469 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
470 m_freem(m);
471 return;
472 }
473
474 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
475 IP6STAT_INC(ip6s_total);
476
477 #ifndef PULLDOWN_TEST
478 /*
479 * L2 bridge code and some other code can return mbuf chain
480 * that does not conform to KAME requirement. too bad.
481 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
482 */
483 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
484 struct mbuf *n;
485
486 if (m->m_pkthdr.len > MHLEN)
487 n = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
488 else
489 n = m_gethdr(M_NOWAIT, MT_DATA);
490 if (n == NULL) {
491 m_freem(m);
492 return; /* ENOBUFS */
493 }
494
495 m_move_pkthdr(n, m);
496 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
497 n->m_len = n->m_pkthdr.len;
498 m_freem(m);
499 m = n;
500 }
501 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
502 #endif
503
504 if (m->m_len < sizeof(struct ip6_hdr)) {
505 struct ifnet *inifp;
506 inifp = m->m_pkthdr.rcvif;
507 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
508 IP6STAT_INC(ip6s_toosmall);
509 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
510 return;
511 }
512 }
513
514 ip6 = mtod(m, struct ip6_hdr *);
515
516 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
517 IP6STAT_INC(ip6s_badvers);
518 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
519 goto bad;
520 }
521
522 IP6STAT_INC(ip6s_nxthist[ip6->ip6_nxt]);
523
524 IP_PROBE(receive, NULL, NULL, ip6, m->m_pkthdr.rcvif, NULL, ip6);
525
526 /*
527 * Check against address spoofing/corruption.
528 */
529 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
530 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
531 /*
532 * XXX: "badscope" is not very suitable for a multicast source.
533 */
534 IP6STAT_INC(ip6s_badscope);
535 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
536 goto bad;
537 }
538 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
539 !(m->m_flags & M_LOOP)) {
540 /*
541 * In this case, the packet should come from the loopback
542 * interface. However, we cannot just check the if_flags,
543 * because ip6_mloopback() passes the "actual" interface
544 * as the outgoing/incoming interface.
545 */
546 IP6STAT_INC(ip6s_badscope);
547 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
548 goto bad;
549 }
550 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
551 IPV6_ADDR_MC_SCOPE(&ip6->ip6_dst) == 0) {
552 /*
553 * RFC4291 2.7:
554 * Nodes must not originate a packet to a multicast address
555 * whose scop field contains the reserved value 0; if such
556 * a packet is received, it must be silently dropped.
557 */
558 IP6STAT_INC(ip6s_badscope);
559 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
560 goto bad;
561 }
562 #ifdef ALTQ
563 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
564 /* packet is dropped by traffic conditioner */
565 return;
566 }
567 #endif
568 /*
569 * The following check is not documented in specs. A malicious
570 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
571 * and bypass security checks (act as if it was from 127.0.0.1 by using
572 * IPv6 src ::ffff:127.0.0.1). Be cautious.
573 *
574 * This check chokes if we are in an SIIT cloud. As none of BSDs
575 * support IPv4-less kernel compilation, we cannot support SIIT
576 * environment at all. So, it makes more sense for us to reject any
577 * malicious packets for non-SIIT environment, than try to do a
578 * partial support for SIIT environment.
579 */
580 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
581 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
582 IP6STAT_INC(ip6s_badscope);
583 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
584 goto bad;
585 }
586 #if 0
587 /*
588 * Reject packets with IPv4 compatible addresses (auto tunnel).
589 *
590 * The code forbids auto tunnel relay case in RFC1933 (the check is
591 * stronger than RFC1933). We may want to re-enable it if mech-xx
592 * is revised to forbid relaying case.
593 */
594 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
595 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
596 IP6STAT_INC(ip6s_badscope);
597 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
598 goto bad;
599 }
600 #endif
601 #ifdef IPSEC
602 /*
603 * Bypass packet filtering for packets previously handled by IPsec.
604 */
605 if (ip6_ipsec_filtertunnel(m))
606 goto passin;
607 #endif /* IPSEC */
608
609 /*
610 * Run through list of hooks for input packets.
611 *
612 * NB: Beware of the destination address changing
613 * (e.g. by NAT rewriting). When this happens,
614 * tell ip6_forward to do the right thing.
615 */
616 odst = ip6->ip6_dst;
617
618 /* Jump over all PFIL processing if hooks are not active. */
619 if (!PFIL_HOOKED(&V_inet6_pfil_hook))
620 goto passin;
621
622 if (pfil_run_hooks(&V_inet6_pfil_hook, &m,
623 m->m_pkthdr.rcvif, PFIL_IN, NULL))
624 return;
625 if (m == NULL) /* consumed by filter */
626 return;
627 ip6 = mtod(m, struct ip6_hdr *);
628 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
629
630 if (m->m_flags & M_FASTFWD_OURS) {
631 m->m_flags &= ~M_FASTFWD_OURS;
632 ours = 1;
633 deliverifp = m->m_pkthdr.rcvif;
634 goto hbhcheck;
635 }
636 if ((m->m_flags & M_IP6_NEXTHOP) &&
637 m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
638 /*
639 * Directly ship the packet on. This allows forwarding
640 * packets originally destined to us to some other directly
641 * connected host.
642 */
643 ip6_forward(m, 1);
644 goto out;
645 }
646
647 passin:
648 /*
649 * Disambiguate address scope zones (if there is ambiguity).
650 * We first make sure that the original source or destination address
651 * is not in our internal form for scoped addresses. Such addresses
652 * are not necessarily invalid spec-wise, but we cannot accept them due
653 * to the usage conflict.
654 * in6_setscope() then also checks and rejects the cases where src or
655 * dst are the loopback address and the receiving interface
656 * is not loopback.
657 */
658 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
659 IP6STAT_INC(ip6s_badscope); /* XXX */
660 goto bad;
661 }
662 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
663 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
664 IP6STAT_INC(ip6s_badscope);
665 goto bad;
666 }
667
668 /*
669 * Multicast check. Assume packet is for us to avoid
670 * prematurely taking locks.
671 */
672 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
673 ours = 1;
674 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
675 deliverifp = m->m_pkthdr.rcvif;
676 goto hbhcheck;
677 }
678
679 /*
680 * Unicast check
681 */
682
683 bzero(&dst6, sizeof(dst6));
684 dst6.sin6_family = AF_INET6;
685 dst6.sin6_len = sizeof(struct sockaddr_in6);
686 dst6.sin6_addr = ip6->ip6_dst;
687 ifp = m->m_pkthdr.rcvif;
688 IF_AFDATA_RLOCK(ifp);
689 lle = lla_lookup(LLTABLE6(ifp), 0,
690 (struct sockaddr *)&dst6);
691 IF_AFDATA_RUNLOCK(ifp);
692 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) {
693 struct ifaddr *ifa;
694 struct in6_ifaddr *ia6;
695 int bad;
696
697 bad = 1;
698 #define sa_equal(a1, a2) \
699 (bcmp((a1), (a2), ((a1))->sin6_len) == 0)
700 IF_ADDR_RLOCK(ifp);
701 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
702 if (ifa->ifa_addr->sa_family != dst6.sin6_family)
703 continue;
704 if (sa_equal(&dst6, ifa->ifa_addr))
705 break;
706 }
707 KASSERT(ifa != NULL, ("%s: ifa not found for lle %p",
708 __func__, lle));
709 #undef sa_equal
710
711 ia6 = (struct in6_ifaddr *)ifa;
712 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
713 /* Count the packet in the ip address stats */
714 ia6->ia_ifa.if_ipackets++;
715 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
716
717 /*
718 * record address information into m_tag.
719 */
720 (void)ip6_setdstifaddr(m, ia6);
721
722 bad = 0;
723 } else {
724 char ip6bufs[INET6_ADDRSTRLEN];
725 char ip6bufd[INET6_ADDRSTRLEN];
726 /* address is not ready, so discard the packet. */
727 nd6log((LOG_INFO,
728 "ip6_input: packet to an unready address %s->%s\n",
729 ip6_sprintf(ip6bufs, &ip6->ip6_src),
730 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
731 }
732 IF_ADDR_RUNLOCK(ifp);
733 LLE_RUNLOCK(lle);
734 if (bad)
735 goto bad;
736 else {
737 ours = 1;
738 deliverifp = ifp;
739 goto hbhcheck;
740 }
741 }
742 if (lle != NULL)
743 LLE_RUNLOCK(lle);
744
745 dst = &rin6.ro_dst;
746 dst->sin6_len = sizeof(struct sockaddr_in6);
747 dst->sin6_family = AF_INET6;
748 dst->sin6_addr = ip6->ip6_dst;
749 rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m));
750 if (rin6.ro_rt)
751 RT_UNLOCK(rin6.ro_rt);
752
753 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
754
755 /*
756 * Accept the packet if the forwarding interface to the destination
757 * according to the routing table is the loopback interface,
758 * unless the associated route has a gateway.
759 * Note that this approach causes to accept a packet if there is a
760 * route to the loopback interface for the destination of the packet.
761 * But we think it's even useful in some situations, e.g. when using
762 * a special daemon which wants to intercept the packet.
763 *
764 * XXX: some OSes automatically make a cloned route for the destination
765 * of an outgoing packet. If the outgoing interface of the packet
766 * is a loopback one, the kernel would consider the packet to be
767 * accepted, even if we have no such address assinged on the interface.
768 * We check the cloned flag of the route entry to reject such cases,
769 * assuming that route entries for our own addresses are not made by
770 * cloning (it should be true because in6_addloop explicitly installs
771 * the host route). However, we might have to do an explicit check
772 * while it would be less efficient. Or, should we rather install a
773 * reject route for such a case?
774 */
775 if (rin6.ro_rt &&
776 (rin6.ro_rt->rt_flags &
777 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
778 #ifdef RTF_WASCLONED
779 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) &&
780 #endif
781 #ifdef RTF_CLONED
782 !(rin6.ro_rt->rt_flags & RTF_CLONED) &&
783 #endif
784 #if 0
785 /*
786 * The check below is redundant since the comparison of
787 * the destination and the key of the rtentry has
788 * already done through looking up the routing table.
789 */
790 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
791 &rt6_key(rin6.ro_rt)->sin6_addr)
792 #endif
793 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) {
794 int free_ia6 = 0;
795 struct in6_ifaddr *ia6;
796
797 /*
798 * found the loopback route to the interface address
799 */
800 if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) {
801 struct sockaddr_in6 dest6;
802
803 bzero(&dest6, sizeof(dest6));
804 dest6.sin6_family = AF_INET6;
805 dest6.sin6_len = sizeof(dest6);
806 dest6.sin6_addr = ip6->ip6_dst;
807 ia6 = (struct in6_ifaddr *)
808 ifa_ifwithaddr((struct sockaddr *)&dest6);
809 if (ia6 == NULL)
810 goto bad;
811 free_ia6 = 1;
812 }
813 else
814 ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa;
815
816 /*
817 * record address information into m_tag.
818 */
819 (void)ip6_setdstifaddr(m, ia6);
820
821 /*
822 * packets to a tentative, duplicated, or somehow invalid
823 * address must not be accepted.
824 */
825 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
826 /* this address is ready */
827 ours = 1;
828 deliverifp = ia6->ia_ifp; /* correct? */
829 /* Count the packet in the ip address stats */
830 ia6->ia_ifa.if_ipackets++;
831 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
832 if (ia6 != NULL && free_ia6 != 0)
833 ifa_free(&ia6->ia_ifa);
834 goto hbhcheck;
835 } else {
836 char ip6bufs[INET6_ADDRSTRLEN];
837 char ip6bufd[INET6_ADDRSTRLEN];
838 /* address is not ready, so discard the packet. */
839 nd6log((LOG_INFO,
840 "ip6_input: packet to an unready address %s->%s\n",
841 ip6_sprintf(ip6bufs, &ip6->ip6_src),
842 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
843
844 if (ia6 != NULL && free_ia6 != 0)
845 ifa_free(&ia6->ia_ifa);
846 goto bad;
847 }
848 }
849
850 /*
851 * FAITH (Firewall Aided Internet Translator)
852 */
853 if (V_ip6_keepfaith) {
854 if (rin6.ro_rt && rin6.ro_rt->rt_ifp &&
855 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) {
856 /* XXX do we need more sanity checks? */
857 ours = 1;
858 deliverifp = rin6.ro_rt->rt_ifp; /* faith */
859 goto hbhcheck;
860 }
861 }
862
863 /*
864 * Now there is no reason to process the packet if it's not our own
865 * and we're not a router.
866 */
867 if (!V_ip6_forwarding) {
868 IP6STAT_INC(ip6s_cantforward);
869 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
870 goto bad;
871 }
872
873 hbhcheck:
874 /*
875 * record address information into m_tag, if we don't have one yet.
876 * note that we are unable to record it, if the address is not listed
877 * as our interface address (e.g. multicast addresses, addresses
878 * within FAITH prefixes and such).
879 */
880 if (deliverifp) {
881 struct in6_ifaddr *ia6;
882
883 if ((ia6 = ip6_getdstifaddr(m)) != NULL) {
884 ifa_free(&ia6->ia_ifa);
885 } else {
886 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
887 if (ia6) {
888 if (!ip6_setdstifaddr(m, ia6)) {
889 /*
890 * XXX maybe we should drop the packet here,
891 * as we could not provide enough information
892 * to the upper layers.
893 */
894 }
895 ifa_free(&ia6->ia_ifa);
896 }
897 }
898 }
899
900 /*
901 * Process Hop-by-Hop options header if it's contained.
902 * m may be modified in ip6_hopopts_input().
903 * If a JumboPayload option is included, plen will also be modified.
904 */
905 plen = (u_int32_t)ntohs(ip6->ip6_plen);
906 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
907 int error;
908
909 error = ip6_input_hbh(m, &plen, &rtalert, &off, &nxt, &ours);
910 if (error != 0)
911 goto out;
912 } else
913 nxt = ip6->ip6_nxt;
914
915 /*
916 * Check that the amount of data in the buffers
917 * is as at least much as the IPv6 header would have us expect.
918 * Trim mbufs if longer than we expect.
919 * Drop packet if shorter than we expect.
920 */
921 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
922 IP6STAT_INC(ip6s_tooshort);
923 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
924 goto bad;
925 }
926 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
927 if (m->m_len == m->m_pkthdr.len) {
928 m->m_len = sizeof(struct ip6_hdr) + plen;
929 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
930 } else
931 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
932 }
933
934 /*
935 * Forward if desirable.
936 */
937 if (V_ip6_mrouter &&
938 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
939 /*
940 * If we are acting as a multicast router, all
941 * incoming multicast packets are passed to the
942 * kernel-level multicast forwarding function.
943 * The packet is returned (relatively) intact; if
944 * ip6_mforward() returns a non-zero value, the packet
945 * must be discarded, else it may be accepted below.
946 *
947 * XXX TODO: Check hlim and multicast scope here to avoid
948 * unnecessarily calling into ip6_mforward().
949 */
950 if (ip6_mforward &&
951 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
952 IP6STAT_INC(ip6s_cantforward);
953 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
954 goto bad;
955 }
956 } else if (!ours) {
957 ip6_forward(m, srcrt);
958 goto out;
959 }
960
961 ip6 = mtod(m, struct ip6_hdr *);
962
963 /*
964 * Malicious party may be able to use IPv4 mapped addr to confuse
965 * tcp/udp stack and bypass security checks (act as if it was from
966 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
967 *
968 * For SIIT end node behavior, you may want to disable the check.
969 * However, you will become vulnerable to attacks using IPv4 mapped
970 * source.
971 */
972 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
973 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
974 IP6STAT_INC(ip6s_badscope);
975 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
976 goto bad;
977 }
978
979 /*
980 * Tell launch routine the next header
981 */
982 IP6STAT_INC(ip6s_delivered);
983 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
984 nest = 0;
985
986 while (nxt != IPPROTO_DONE) {
987 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
988 IP6STAT_INC(ip6s_toomanyhdr);
989 goto bad;
990 }
991
992 /*
993 * protection against faulty packet - there should be
994 * more sanity checks in header chain processing.
995 */
996 if (m->m_pkthdr.len < off) {
997 IP6STAT_INC(ip6s_tooshort);
998 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
999 goto bad;
1000 }
1001
1002 #ifdef IPSEC
1003 /*
1004 * enforce IPsec policy checking if we are seeing last header.
1005 * note that we do not visit this with protocols with pcb layer
1006 * code - like udp/tcp/raw ip.
1007 */
1008 if (ip6_ipsec_input(m, nxt))
1009 goto bad;
1010 #endif /* IPSEC */
1011
1012 /*
1013 * Use mbuf flags to propagate Router Alert option to
1014 * ICMPv6 layer, as hop-by-hop options have been stripped.
1015 */
1016 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0)
1017 m->m_flags |= M_RTALERT_MLD;
1018
1019 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
1020 }
1021 goto out;
1022 bad:
1023 m_freem(m);
1024 out:
1025 if (rin6.ro_rt)
1026 RTFREE(rin6.ro_rt);
1027 }
1028
1029 /*
1030 * set/grab in6_ifaddr correspond to IPv6 destination address.
1031 * XXX backward compatibility wrapper
1032 *
1033 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag,
1034 * and then bump it when the tag is copied, and release it when the tag is
1035 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead
1036 * we just bump the ia refcount when we receive it. This should be fixed.
1037 */
1038 static struct ip6aux *
ip6_setdstifaddr(struct mbuf * m,struct in6_ifaddr * ia6)1039 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
1040 {
1041 struct ip6aux *ip6a;
1042
1043 ip6a = ip6_addaux(m);
1044 if (ip6a)
1045 ip6a->ip6a_dstia6 = ia6;
1046 return ip6a; /* NULL if failed to set */
1047 }
1048
1049 struct in6_ifaddr *
ip6_getdstifaddr(struct mbuf * m)1050 ip6_getdstifaddr(struct mbuf *m)
1051 {
1052 struct ip6aux *ip6a;
1053 struct in6_ifaddr *ia;
1054
1055 ip6a = ip6_findaux(m);
1056 if (ip6a) {
1057 ia = ip6a->ip6a_dstia6;
1058 ifa_ref(&ia->ia_ifa);
1059 return ia;
1060 } else
1061 return NULL;
1062 }
1063
1064 /*
1065 * Hop-by-Hop options header processing. If a valid jumbo payload option is
1066 * included, the real payload length will be stored in plenp.
1067 *
1068 * rtalertp - XXX: should be stored more smart way
1069 */
1070 static int
ip6_hopopts_input(u_int32_t * plenp,u_int32_t * rtalertp,struct mbuf ** mp,int * offp)1071 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
1072 struct mbuf **mp, int *offp)
1073 {
1074 struct mbuf *m = *mp;
1075 int off = *offp, hbhlen;
1076 struct ip6_hbh *hbh;
1077
1078 /* validation of the length of the header */
1079 #ifndef PULLDOWN_TEST
1080 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
1081 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1082 hbhlen = (hbh->ip6h_len + 1) << 3;
1083
1084 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
1085 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1086 #else
1087 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
1088 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
1089 if (hbh == NULL) {
1090 IP6STAT_INC(ip6s_tooshort);
1091 return -1;
1092 }
1093 hbhlen = (hbh->ip6h_len + 1) << 3;
1094 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
1095 hbhlen);
1096 if (hbh == NULL) {
1097 IP6STAT_INC(ip6s_tooshort);
1098 return -1;
1099 }
1100 #endif
1101 off += hbhlen;
1102 hbhlen -= sizeof(struct ip6_hbh);
1103 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
1104 hbhlen, rtalertp, plenp) < 0)
1105 return (-1);
1106
1107 *offp = off;
1108 *mp = m;
1109 return (0);
1110 }
1111
1112 /*
1113 * Search header for all Hop-by-hop options and process each option.
1114 * This function is separate from ip6_hopopts_input() in order to
1115 * handle a case where the sending node itself process its hop-by-hop
1116 * options header. In such a case, the function is called from ip6_output().
1117 *
1118 * The function assumes that hbh header is located right after the IPv6 header
1119 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
1120 * opthead + hbhlen is located in contiguous memory region.
1121 */
1122 int
ip6_process_hopopts(struct mbuf * m,u_int8_t * opthead,int hbhlen,u_int32_t * rtalertp,u_int32_t * plenp)1123 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
1124 u_int32_t *rtalertp, u_int32_t *plenp)
1125 {
1126 struct ip6_hdr *ip6;
1127 int optlen = 0;
1128 u_int8_t *opt = opthead;
1129 u_int16_t rtalert_val;
1130 u_int32_t jumboplen;
1131 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
1132
1133 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
1134 switch (*opt) {
1135 case IP6OPT_PAD1:
1136 optlen = 1;
1137 break;
1138 case IP6OPT_PADN:
1139 if (hbhlen < IP6OPT_MINLEN) {
1140 IP6STAT_INC(ip6s_toosmall);
1141 goto bad;
1142 }
1143 optlen = *(opt + 1) + 2;
1144 break;
1145 case IP6OPT_ROUTER_ALERT:
1146 /* XXX may need check for alignment */
1147 if (hbhlen < IP6OPT_RTALERT_LEN) {
1148 IP6STAT_INC(ip6s_toosmall);
1149 goto bad;
1150 }
1151 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
1152 /* XXX stat */
1153 icmp6_error(m, ICMP6_PARAM_PROB,
1154 ICMP6_PARAMPROB_HEADER,
1155 erroff + opt + 1 - opthead);
1156 return (-1);
1157 }
1158 optlen = IP6OPT_RTALERT_LEN;
1159 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
1160 *rtalertp = ntohs(rtalert_val);
1161 break;
1162 case IP6OPT_JUMBO:
1163 /* XXX may need check for alignment */
1164 if (hbhlen < IP6OPT_JUMBO_LEN) {
1165 IP6STAT_INC(ip6s_toosmall);
1166 goto bad;
1167 }
1168 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
1169 /* XXX stat */
1170 icmp6_error(m, ICMP6_PARAM_PROB,
1171 ICMP6_PARAMPROB_HEADER,
1172 erroff + opt + 1 - opthead);
1173 return (-1);
1174 }
1175 optlen = IP6OPT_JUMBO_LEN;
1176
1177 /*
1178 * IPv6 packets that have non 0 payload length
1179 * must not contain a jumbo payload option.
1180 */
1181 ip6 = mtod(m, struct ip6_hdr *);
1182 if (ip6->ip6_plen) {
1183 IP6STAT_INC(ip6s_badoptions);
1184 icmp6_error(m, ICMP6_PARAM_PROB,
1185 ICMP6_PARAMPROB_HEADER,
1186 erroff + opt - opthead);
1187 return (-1);
1188 }
1189
1190 /*
1191 * We may see jumbolen in unaligned location, so
1192 * we'd need to perform bcopy().
1193 */
1194 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1195 jumboplen = (u_int32_t)htonl(jumboplen);
1196
1197 #if 1
1198 /*
1199 * if there are multiple jumbo payload options,
1200 * *plenp will be non-zero and the packet will be
1201 * rejected.
1202 * the behavior may need some debate in ipngwg -
1203 * multiple options does not make sense, however,
1204 * there's no explicit mention in specification.
1205 */
1206 if (*plenp != 0) {
1207 IP6STAT_INC(ip6s_badoptions);
1208 icmp6_error(m, ICMP6_PARAM_PROB,
1209 ICMP6_PARAMPROB_HEADER,
1210 erroff + opt + 2 - opthead);
1211 return (-1);
1212 }
1213 #endif
1214
1215 /*
1216 * jumbo payload length must be larger than 65535.
1217 */
1218 if (jumboplen <= IPV6_MAXPACKET) {
1219 IP6STAT_INC(ip6s_badoptions);
1220 icmp6_error(m, ICMP6_PARAM_PROB,
1221 ICMP6_PARAMPROB_HEADER,
1222 erroff + opt + 2 - opthead);
1223 return (-1);
1224 }
1225 *plenp = jumboplen;
1226
1227 break;
1228 default: /* unknown option */
1229 if (hbhlen < IP6OPT_MINLEN) {
1230 IP6STAT_INC(ip6s_toosmall);
1231 goto bad;
1232 }
1233 optlen = ip6_unknown_opt(opt, m,
1234 erroff + opt - opthead);
1235 if (optlen == -1)
1236 return (-1);
1237 optlen += 2;
1238 break;
1239 }
1240 }
1241
1242 return (0);
1243
1244 bad:
1245 m_freem(m);
1246 return (-1);
1247 }
1248
1249 /*
1250 * Unknown option processing.
1251 * The third argument `off' is the offset from the IPv6 header to the option,
1252 * which is necessary if the IPv6 header the and option header and IPv6 header
1253 * is not contiguous in order to return an ICMPv6 error.
1254 */
1255 int
ip6_unknown_opt(u_int8_t * optp,struct mbuf * m,int off)1256 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1257 {
1258 struct ip6_hdr *ip6;
1259
1260 switch (IP6OPT_TYPE(*optp)) {
1261 case IP6OPT_TYPE_SKIP: /* ignore the option */
1262 return ((int)*(optp + 1));
1263 case IP6OPT_TYPE_DISCARD: /* silently discard */
1264 m_freem(m);
1265 return (-1);
1266 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1267 IP6STAT_INC(ip6s_badoptions);
1268 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1269 return (-1);
1270 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1271 IP6STAT_INC(ip6s_badoptions);
1272 ip6 = mtod(m, struct ip6_hdr *);
1273 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1274 (m->m_flags & (M_BCAST|M_MCAST)))
1275 m_freem(m);
1276 else
1277 icmp6_error(m, ICMP6_PARAM_PROB,
1278 ICMP6_PARAMPROB_OPTION, off);
1279 return (-1);
1280 }
1281
1282 m_freem(m); /* XXX: NOTREACHED */
1283 return (-1);
1284 }
1285
1286 /*
1287 * Create the "control" list for this pcb.
1288 * These functions will not modify mbuf chain at all.
1289 *
1290 * With KAME mbuf chain restriction:
1291 * The routine will be called from upper layer handlers like tcp6_input().
1292 * Thus the routine assumes that the caller (tcp6_input) have already
1293 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1294 * very first mbuf on the mbuf chain.
1295 *
1296 * ip6_savecontrol_v4 will handle those options that are possible to be
1297 * set on a v4-mapped socket.
1298 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1299 * options and handle the v6-only ones itself.
1300 */
1301 struct mbuf **
ip6_savecontrol_v4(struct inpcb * inp,struct mbuf * m,struct mbuf ** mp,int * v4only)1302 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1303 int *v4only)
1304 {
1305 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1306
1307 #ifdef SO_TIMESTAMP
1308 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
1309 struct timeval tv;
1310
1311 microtime(&tv);
1312 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1313 SCM_TIMESTAMP, SOL_SOCKET);
1314 if (*mp)
1315 mp = &(*mp)->m_next;
1316 }
1317 #endif
1318
1319 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1320 /* RFC 2292 sec. 5 */
1321 if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1322 struct in6_pktinfo pi6;
1323
1324 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1325 #ifdef INET
1326 struct ip *ip;
1327
1328 ip = mtod(m, struct ip *);
1329 pi6.ipi6_addr.s6_addr32[0] = 0;
1330 pi6.ipi6_addr.s6_addr32[1] = 0;
1331 pi6.ipi6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
1332 pi6.ipi6_addr.s6_addr32[3] = ip->ip_dst.s_addr;
1333 #else
1334 /* We won't hit this code */
1335 bzero(&pi6.ipi6_addr, sizeof(struct in6_addr));
1336 #endif
1337 } else {
1338 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1339 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1340 }
1341 pi6.ipi6_ifindex =
1342 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1343
1344 *mp = sbcreatecontrol((caddr_t) &pi6,
1345 sizeof(struct in6_pktinfo),
1346 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1347 if (*mp)
1348 mp = &(*mp)->m_next;
1349 }
1350
1351 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1352 int hlim;
1353
1354 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1355 #ifdef INET
1356 struct ip *ip;
1357
1358 ip = mtod(m, struct ip *);
1359 hlim = ip->ip_ttl;
1360 #else
1361 /* We won't hit this code */
1362 hlim = 0;
1363 #endif
1364 } else {
1365 hlim = ip6->ip6_hlim & 0xff;
1366 }
1367 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1368 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1369 IPPROTO_IPV6);
1370 if (*mp)
1371 mp = &(*mp)->m_next;
1372 }
1373
1374 if ((inp->inp_flags & IN6P_TCLASS) != 0) {
1375 int tclass;
1376
1377 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1378 #ifdef INET
1379 struct ip *ip;
1380
1381 ip = mtod(m, struct ip *);
1382 tclass = ip->ip_tos;
1383 #else
1384 /* We won't hit this code */
1385 tclass = 0;
1386 #endif
1387 } else {
1388 u_int32_t flowinfo;
1389
1390 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1391 flowinfo >>= 20;
1392 tclass = flowinfo & 0xff;
1393 }
1394 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(int),
1395 IPV6_TCLASS, IPPROTO_IPV6);
1396 if (*mp)
1397 mp = &(*mp)->m_next;
1398 }
1399
1400 if (v4only != NULL) {
1401 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1402 *v4only = 1;
1403 } else {
1404 *v4only = 0;
1405 }
1406 }
1407
1408 return (mp);
1409 }
1410
1411 void
ip6_savecontrol(struct inpcb * in6p,struct mbuf * m,struct mbuf ** mp)1412 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
1413 {
1414 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1415 int v4only = 0;
1416
1417 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
1418 if (v4only)
1419 return;
1420
1421 /*
1422 * IPV6_HOPOPTS socket option. Recall that we required super-user
1423 * privilege for the option (see ip6_ctloutput), but it might be too
1424 * strict, since there might be some hop-by-hop options which can be
1425 * returned to normal user.
1426 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1427 */
1428 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) {
1429 /*
1430 * Check if a hop-by-hop options header is contatined in the
1431 * received packet, and if so, store the options as ancillary
1432 * data. Note that a hop-by-hop options header must be
1433 * just after the IPv6 header, which is assured through the
1434 * IPv6 input processing.
1435 */
1436 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1437 struct ip6_hbh *hbh;
1438 int hbhlen = 0;
1439 #ifdef PULLDOWN_TEST
1440 struct mbuf *ext;
1441 #endif
1442
1443 #ifndef PULLDOWN_TEST
1444 hbh = (struct ip6_hbh *)(ip6 + 1);
1445 hbhlen = (hbh->ip6h_len + 1) << 3;
1446 #else
1447 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1448 ip6->ip6_nxt);
1449 if (ext == NULL) {
1450 IP6STAT_INC(ip6s_tooshort);
1451 return;
1452 }
1453 hbh = mtod(ext, struct ip6_hbh *);
1454 hbhlen = (hbh->ip6h_len + 1) << 3;
1455 if (hbhlen != ext->m_len) {
1456 m_freem(ext);
1457 IP6STAT_INC(ip6s_tooshort);
1458 return;
1459 }
1460 #endif
1461
1462 /*
1463 * XXX: We copy the whole header even if a
1464 * jumbo payload option is included, the option which
1465 * is to be removed before returning according to
1466 * RFC2292.
1467 * Note: this constraint is removed in RFC3542
1468 */
1469 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1470 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1471 IPPROTO_IPV6);
1472 if (*mp)
1473 mp = &(*mp)->m_next;
1474 #ifdef PULLDOWN_TEST
1475 m_freem(ext);
1476 #endif
1477 }
1478 }
1479
1480 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1481 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1482
1483 /*
1484 * Search for destination options headers or routing
1485 * header(s) through the header chain, and stores each
1486 * header as ancillary data.
1487 * Note that the order of the headers remains in
1488 * the chain of ancillary data.
1489 */
1490 while (1) { /* is explicit loop prevention necessary? */
1491 struct ip6_ext *ip6e = NULL;
1492 int elen;
1493 #ifdef PULLDOWN_TEST
1494 struct mbuf *ext = NULL;
1495 #endif
1496
1497 /*
1498 * if it is not an extension header, don't try to
1499 * pull it from the chain.
1500 */
1501 switch (nxt) {
1502 case IPPROTO_DSTOPTS:
1503 case IPPROTO_ROUTING:
1504 case IPPROTO_HOPOPTS:
1505 case IPPROTO_AH: /* is it possible? */
1506 break;
1507 default:
1508 goto loopend;
1509 }
1510
1511 #ifndef PULLDOWN_TEST
1512 if (off + sizeof(*ip6e) > m->m_len)
1513 goto loopend;
1514 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1515 if (nxt == IPPROTO_AH)
1516 elen = (ip6e->ip6e_len + 2) << 2;
1517 else
1518 elen = (ip6e->ip6e_len + 1) << 3;
1519 if (off + elen > m->m_len)
1520 goto loopend;
1521 #else
1522 ext = ip6_pullexthdr(m, off, nxt);
1523 if (ext == NULL) {
1524 IP6STAT_INC(ip6s_tooshort);
1525 return;
1526 }
1527 ip6e = mtod(ext, struct ip6_ext *);
1528 if (nxt == IPPROTO_AH)
1529 elen = (ip6e->ip6e_len + 2) << 2;
1530 else
1531 elen = (ip6e->ip6e_len + 1) << 3;
1532 if (elen != ext->m_len) {
1533 m_freem(ext);
1534 IP6STAT_INC(ip6s_tooshort);
1535 return;
1536 }
1537 #endif
1538
1539 switch (nxt) {
1540 case IPPROTO_DSTOPTS:
1541 if (!(in6p->inp_flags & IN6P_DSTOPTS))
1542 break;
1543
1544 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1545 IS2292(in6p,
1546 IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1547 IPPROTO_IPV6);
1548 if (*mp)
1549 mp = &(*mp)->m_next;
1550 break;
1551 case IPPROTO_ROUTING:
1552 if (!(in6p->inp_flags & IN6P_RTHDR))
1553 break;
1554
1555 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1556 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
1557 IPPROTO_IPV6);
1558 if (*mp)
1559 mp = &(*mp)->m_next;
1560 break;
1561 case IPPROTO_HOPOPTS:
1562 case IPPROTO_AH: /* is it possible? */
1563 break;
1564
1565 default:
1566 /*
1567 * other cases have been filtered in the above.
1568 * none will visit this case. here we supply
1569 * the code just in case (nxt overwritten or
1570 * other cases).
1571 */
1572 #ifdef PULLDOWN_TEST
1573 m_freem(ext);
1574 #endif
1575 goto loopend;
1576
1577 }
1578
1579 /* proceed with the next header. */
1580 off += elen;
1581 nxt = ip6e->ip6e_nxt;
1582 ip6e = NULL;
1583 #ifdef PULLDOWN_TEST
1584 m_freem(ext);
1585 ext = NULL;
1586 #endif
1587 }
1588 loopend:
1589 ;
1590 }
1591 }
1592 #undef IS2292
1593
1594 void
ip6_notify_pmtu(struct inpcb * inp,struct sockaddr_in6 * dst,u_int32_t mtu)1595 ip6_notify_pmtu(struct inpcb *inp, struct sockaddr_in6 *dst, u_int32_t mtu)
1596 {
1597 struct socket *so;
1598 struct mbuf *m_mtu;
1599 struct ip6_mtuinfo mtuctl;
1600
1601 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1602 /*
1603 * Notify the error by sending IPV6_PATHMTU ancillary data if
1604 * application wanted to know the MTU value.
1605 * NOTE: we notify disconnected sockets, because some udp
1606 * applications keep sending sockets disconnected.
1607 * NOTE: our implementation doesn't notify connected sockets that has
1608 * foreign address that is different than given destination addresses
1609 * (this is permitted by RFC 3542).
1610 */
1611 if ((inp->inp_flags & IN6P_MTU) == 0 || (
1612 !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1613 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &dst->sin6_addr)))
1614 return;
1615
1616 mtuctl.ip6m_mtu = mtu;
1617 mtuctl.ip6m_addr = *dst;
1618 if (sa6_recoverscope(&mtuctl.ip6m_addr))
1619 return;
1620
1621 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1622 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1623 return;
1624
1625 so = inp->inp_socket;
1626 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1627 == 0) {
1628 m_freem(m_mtu);
1629 /* XXX: should count statistics */
1630 } else
1631 sorwakeup(so);
1632 }
1633
1634 #ifdef PULLDOWN_TEST
1635 /*
1636 * pull single extension header from mbuf chain. returns single mbuf that
1637 * contains the result, or NULL on error.
1638 */
1639 static struct mbuf *
ip6_pullexthdr(struct mbuf * m,size_t off,int nxt)1640 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1641 {
1642 struct ip6_ext ip6e;
1643 size_t elen;
1644 struct mbuf *n;
1645
1646 #ifdef DIAGNOSTIC
1647 switch (nxt) {
1648 case IPPROTO_DSTOPTS:
1649 case IPPROTO_ROUTING:
1650 case IPPROTO_HOPOPTS:
1651 case IPPROTO_AH: /* is it possible? */
1652 break;
1653 default:
1654 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1655 }
1656 #endif
1657
1658 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1659 if (nxt == IPPROTO_AH)
1660 elen = (ip6e.ip6e_len + 2) << 2;
1661 else
1662 elen = (ip6e.ip6e_len + 1) << 3;
1663
1664 if (elen > MLEN)
1665 n = m_getcl(M_NOWAIT, MT_DATA, 0);
1666 else
1667 n = m_get(M_NOWAIT, MT_DATA);
1668 if (n == NULL)
1669 return NULL;
1670
1671 m_copydata(m, off, elen, mtod(n, caddr_t));
1672 n->m_len = elen;
1673 return n;
1674 }
1675 #endif
1676
1677 /*
1678 * Get pointer to the previous header followed by the header
1679 * currently processed.
1680 * XXX: This function supposes that
1681 * M includes all headers,
1682 * the next header field and the header length field of each header
1683 * are valid, and
1684 * the sum of each header length equals to OFF.
1685 * Because of these assumptions, this function must be called very
1686 * carefully. Moreover, it will not be used in the near future when
1687 * we develop `neater' mechanism to process extension headers.
1688 */
1689 char *
ip6_get_prevhdr(struct mbuf * m,int off)1690 ip6_get_prevhdr(struct mbuf *m, int off)
1691 {
1692 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1693
1694 if (off == sizeof(struct ip6_hdr))
1695 return (&ip6->ip6_nxt);
1696 else {
1697 int len, nxt;
1698 struct ip6_ext *ip6e = NULL;
1699
1700 nxt = ip6->ip6_nxt;
1701 len = sizeof(struct ip6_hdr);
1702 while (len < off) {
1703 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1704
1705 switch (nxt) {
1706 case IPPROTO_FRAGMENT:
1707 len += sizeof(struct ip6_frag);
1708 break;
1709 case IPPROTO_AH:
1710 len += (ip6e->ip6e_len + 2) << 2;
1711 break;
1712 default:
1713 len += (ip6e->ip6e_len + 1) << 3;
1714 break;
1715 }
1716 nxt = ip6e->ip6e_nxt;
1717 }
1718 if (ip6e)
1719 return (&ip6e->ip6e_nxt);
1720 else
1721 return NULL;
1722 }
1723 }
1724
1725 /*
1726 * get next header offset. m will be retained.
1727 */
1728 int
ip6_nexthdr(struct mbuf * m,int off,int proto,int * nxtp)1729 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1730 {
1731 struct ip6_hdr ip6;
1732 struct ip6_ext ip6e;
1733 struct ip6_frag fh;
1734
1735 /* just in case */
1736 if (m == NULL)
1737 panic("ip6_nexthdr: m == NULL");
1738 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1739 return -1;
1740
1741 switch (proto) {
1742 case IPPROTO_IPV6:
1743 if (m->m_pkthdr.len < off + sizeof(ip6))
1744 return -1;
1745 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1746 if (nxtp)
1747 *nxtp = ip6.ip6_nxt;
1748 off += sizeof(ip6);
1749 return off;
1750
1751 case IPPROTO_FRAGMENT:
1752 /*
1753 * terminate parsing if it is not the first fragment,
1754 * it does not make sense to parse through it.
1755 */
1756 if (m->m_pkthdr.len < off + sizeof(fh))
1757 return -1;
1758 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1759 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1760 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1761 return -1;
1762 if (nxtp)
1763 *nxtp = fh.ip6f_nxt;
1764 off += sizeof(struct ip6_frag);
1765 return off;
1766
1767 case IPPROTO_AH:
1768 if (m->m_pkthdr.len < off + sizeof(ip6e))
1769 return -1;
1770 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1771 if (nxtp)
1772 *nxtp = ip6e.ip6e_nxt;
1773 off += (ip6e.ip6e_len + 2) << 2;
1774 return off;
1775
1776 case IPPROTO_HOPOPTS:
1777 case IPPROTO_ROUTING:
1778 case IPPROTO_DSTOPTS:
1779 if (m->m_pkthdr.len < off + sizeof(ip6e))
1780 return -1;
1781 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1782 if (nxtp)
1783 *nxtp = ip6e.ip6e_nxt;
1784 off += (ip6e.ip6e_len + 1) << 3;
1785 return off;
1786
1787 case IPPROTO_NONE:
1788 case IPPROTO_ESP:
1789 case IPPROTO_IPCOMP:
1790 /* give up */
1791 return -1;
1792
1793 default:
1794 return -1;
1795 }
1796
1797 return -1;
1798 }
1799
1800 /*
1801 * get offset for the last header in the chain. m will be kept untainted.
1802 */
1803 int
ip6_lasthdr(struct mbuf * m,int off,int proto,int * nxtp)1804 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1805 {
1806 int newoff;
1807 int nxt;
1808
1809 if (!nxtp) {
1810 nxt = -1;
1811 nxtp = &nxt;
1812 }
1813 while (1) {
1814 newoff = ip6_nexthdr(m, off, proto, nxtp);
1815 if (newoff < 0)
1816 return off;
1817 else if (newoff < off)
1818 return -1; /* invalid */
1819 else if (newoff == off)
1820 return newoff;
1821
1822 off = newoff;
1823 proto = *nxtp;
1824 }
1825 }
1826
1827 static struct ip6aux *
ip6_addaux(struct mbuf * m)1828 ip6_addaux(struct mbuf *m)
1829 {
1830 struct m_tag *mtag;
1831
1832 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1833 if (!mtag) {
1834 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1835 M_NOWAIT);
1836 if (mtag) {
1837 m_tag_prepend(m, mtag);
1838 bzero(mtag + 1, sizeof(struct ip6aux));
1839 }
1840 }
1841 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1842 }
1843
1844 static struct ip6aux *
ip6_findaux(struct mbuf * m)1845 ip6_findaux(struct mbuf *m)
1846 {
1847 struct m_tag *mtag;
1848
1849 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1850 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1851 }
1852
1853 static void
ip6_delaux(struct mbuf * m)1854 ip6_delaux(struct mbuf *m)
1855 {
1856 struct m_tag *mtag;
1857
1858 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1859 if (mtag)
1860 m_tag_delete(m, mtag);
1861 }
1862
1863 /*
1864 * System control for IP6
1865 */
1866
1867 u_char inet6ctlerrmap[PRC_NCMDS] = {
1868 0, 0, 0, 0,
1869 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1870 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1871 EMSGSIZE, EHOSTUNREACH, 0, 0,
1872 0, 0, 0, 0,
1873 ENOPROTOOPT
1874 };
1875