1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $
32 */
33
34 /*-
35 * Copyright (c) 1982, 1986, 1988, 1993
36 * The Regents of the University of California. All rights reserved.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. Neither the name of the University nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 */
62
63 #include <sys/cdefs.h>
64 #include "opt_inet.h"
65 #include "opt_inet6.h"
66 #include "opt_ipsec.h"
67 #include "opt_route.h"
68 #include "opt_rss.h"
69 #include "opt_sctp.h"
70
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/hhook.h>
74 #include <sys/malloc.h>
75 #include <sys/mbuf.h>
76 #include <sys/proc.h>
77 #include <sys/domain.h>
78 #include <sys/protosw.h>
79 #include <sys/sdt.h>
80 #include <sys/socket.h>
81 #include <sys/socketvar.h>
82 #include <sys/errno.h>
83 #include <sys/time.h>
84 #include <sys/kernel.h>
85 #include <sys/lock.h>
86 #include <sys/rmlock.h>
87 #include <sys/syslog.h>
88 #include <sys/sysctl.h>
89 #include <sys/eventhandler.h>
90
91 #include <net/if.h>
92 #include <net/if_var.h>
93 #include <net/if_types.h>
94 #include <net/if_private.h>
95 #include <net/if_dl.h>
96 #include <net/route.h>
97 #include <net/netisr.h>
98 #include <net/rss_config.h>
99 #include <net/pfil.h>
100 #include <net/vnet.h>
101
102 #include <netinet/in.h>
103 #include <netinet/in_kdtrace.h>
104 #include <netinet/ip_var.h>
105 #include <netinet/in_systm.h>
106 #include <net/if_llatbl.h>
107 #ifdef INET
108 #include <netinet/ip.h>
109 #include <netinet/ip_icmp.h>
110 #endif /* INET */
111 #include <netinet/ip6.h>
112 #include <netinet6/in6_var.h>
113 #include <netinet6/ip6_var.h>
114 #include <netinet/ip_encap.h>
115 #include <netinet/in_pcb.h>
116 #include <netinet/icmp6.h>
117 #include <netinet6/scope6_var.h>
118 #include <netinet6/in6_ifattach.h>
119 #include <netinet6/mld6_var.h>
120 #include <netinet6/nd6.h>
121 #include <netinet6/in6_rss.h>
122 #ifdef SCTP
123 #include <netinet/sctp_pcb.h>
124 #include <netinet6/sctp6_var.h>
125 #endif
126
127 #include <netipsec/ipsec_support.h>
128
129 ip6proto_input_t *ip6_protox[IPPROTO_MAX] = {
130 [0 ... IPPROTO_MAX - 1] = rip6_input };
131 ip6proto_ctlinput_t *ip6_ctlprotox[IPPROTO_MAX] = {
132 [0 ... IPPROTO_MAX - 1] = rip6_ctlinput };
133
134 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
135 VNET_DEFINE(struct in6_ifaddrlisthead *, in6_ifaddrhashtbl);
136 VNET_DEFINE(u_long, in6_ifaddrhmask);
137
138 static struct netisr_handler ip6_nh = {
139 .nh_name = "ip6",
140 .nh_handler = ip6_input,
141 .nh_proto = NETISR_IPV6,
142 #ifdef RSS
143 .nh_m2cpuid = rss_soft_m2cpuid_v6,
144 .nh_policy = NETISR_POLICY_CPU,
145 .nh_dispatch = NETISR_DISPATCH_HYBRID,
146 #else
147 .nh_policy = NETISR_POLICY_FLOW,
148 #endif
149 };
150
151 static int
sysctl_netinet6_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)152 sysctl_netinet6_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
153 {
154 int error, qlimit;
155
156 netisr_getqlimit(&ip6_nh, &qlimit);
157 error = sysctl_handle_int(oidp, &qlimit, 0, req);
158 if (error || !req->newptr)
159 return (error);
160 if (qlimit < 1)
161 return (EINVAL);
162 return (netisr_setqlimit(&ip6_nh, qlimit));
163 }
164 SYSCTL_DECL(_net_inet6_ip6);
165 SYSCTL_PROC(_net_inet6_ip6, IPV6CTL_INTRQMAXLEN, intr_queue_maxlen,
166 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
167 0, 0, sysctl_netinet6_intr_queue_maxlen, "I",
168 "Maximum size of the IPv6 input queue");
169
170 VNET_DEFINE_STATIC(bool, ip6_sav) = true;
171 #define V_ip6_sav VNET(ip6_sav)
172 SYSCTL_BOOL(_net_inet6_ip6, OID_AUTO, source_address_validation,
173 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_sav), true,
174 "Drop incoming packets with source address that is a local address");
175
176 SYSCTL_UINT(_net_inet6_ip6, OID_AUTO, temp_max_desync_factor,
177 CTLFLAG_RD | CTLFLAG_VNET,
178 &VNET_NAME(ip6_temp_max_desync_factor), 0,
179 "RFC 8981 max desync factor");
180
181 #ifdef RSS
182 static struct netisr_handler ip6_direct_nh = {
183 .nh_name = "ip6_direct",
184 .nh_handler = ip6_direct_input,
185 .nh_proto = NETISR_IPV6_DIRECT,
186 .nh_m2cpuid = rss_soft_m2cpuid_v6,
187 .nh_policy = NETISR_POLICY_CPU,
188 .nh_dispatch = NETISR_DISPATCH_HYBRID,
189 };
190
191 static int
sysctl_netinet6_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)192 sysctl_netinet6_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
193 {
194 int error, qlimit;
195
196 netisr_getqlimit(&ip6_direct_nh, &qlimit);
197 error = sysctl_handle_int(oidp, &qlimit, 0, req);
198 if (error || !req->newptr)
199 return (error);
200 if (qlimit < 1)
201 return (EINVAL);
202 return (netisr_setqlimit(&ip6_direct_nh, qlimit));
203 }
204 SYSCTL_PROC(_net_inet6_ip6, IPV6CTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
205 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
206 0, 0, sysctl_netinet6_intr_direct_queue_maxlen, "I",
207 "Maximum size of the IPv6 direct input queue");
208
209 #endif
210
211 VNET_DEFINE(pfil_head_t, inet6_pfil_head);
212 VNET_DEFINE(pfil_head_t, inet6_local_pfil_head);
213
214 VNET_PCPUSTAT_DEFINE(struct ip6stat, ip6stat);
215 VNET_PCPUSTAT_SYSINIT(ip6stat);
216 #ifdef VIMAGE
217 VNET_PCPUSTAT_SYSUNINIT(ip6stat);
218 #endif /* VIMAGE */
219
220 struct rmlock in6_ifaddr_lock;
221 RM_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
222
223 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
224
225 /*
226 * IP6 initialization: fill in IP6 protocol switch table.
227 * All protocols not implemented in kernel go to raw IP6 protocol handler.
228 */
229 static void
ip6_vnet_init(void * arg __unused)230 ip6_vnet_init(void *arg __unused)
231 {
232 struct pfil_head_args args;
233
234 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal",
235 &V_ip6_auto_linklocal);
236 TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv);
237 TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr);
238 TUNABLE_BOOL_FETCH("net.inet6.ip6.use_stableaddr", &V_ip6_use_stableaddr);
239
240 CK_STAILQ_INIT(&V_in6_ifaddrhead);
241 V_in6_ifaddrhashtbl = hashinit(IN6ADDR_NHASH, M_IFADDR,
242 &V_in6_ifaddrhmask);
243
244 /* Initialize packet filter hooks. */
245 args.pa_version = PFIL_VERSION;
246 args.pa_flags = PFIL_IN | PFIL_OUT;
247 args.pa_type = PFIL_TYPE_IP6;
248 args.pa_headname = PFIL_INET6_NAME;
249 V_inet6_pfil_head = pfil_head_register(&args);
250
251 args.pa_flags = PFIL_OUT;
252 args.pa_headname = PFIL_INET6_LOCAL_NAME;
253 V_inet6_local_pfil_head = pfil_head_register(&args);
254
255 if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET6,
256 &V_ipsec_hhh_in[HHOOK_IPSEC_INET6],
257 HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
258 printf("%s: WARNING: unable to register input helper hook\n",
259 __func__);
260 if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET6,
261 &V_ipsec_hhh_out[HHOOK_IPSEC_INET6],
262 HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
263 printf("%s: WARNING: unable to register output helper hook\n",
264 __func__);
265
266 scope6_init();
267 addrsel_policy_init();
268 nd6_init();
269 frag6_init();
270
271 V_ip6_temp_max_desync_factor = TEMP_MAX_DESYNC_FACTOR_BASE +
272 (V_ip6_temp_preferred_lifetime >> 2) +
273 (V_ip6_temp_preferred_lifetime >> 3);
274 V_ip6_desync_factor = arc4random() % V_ip6_temp_max_desync_factor;
275
276 /* Skip global initialization stuff for non-default instances. */
277 #ifdef VIMAGE
278 netisr_register_vnet(&ip6_nh);
279 #ifdef RSS
280 netisr_register_vnet(&ip6_direct_nh);
281 #endif
282 #endif
283 }
284 VNET_SYSINIT(ip6_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
285 ip6_vnet_init, NULL);
286
287 static void
ip6_init(void * arg __unused)288 ip6_init(void *arg __unused)
289 {
290
291 /*
292 * Register statically those protocols that are unlikely to ever go
293 * dynamic.
294 */
295 IP6PROTO_REGISTER(IPPROTO_ICMPV6, icmp6_input, rip6_ctlinput);
296 IP6PROTO_REGISTER(IPPROTO_DSTOPTS, dest6_input, NULL);
297 IP6PROTO_REGISTER(IPPROTO_ROUTING, route6_input, NULL);
298 IP6PROTO_REGISTER(IPPROTO_FRAGMENT, frag6_input, NULL);
299 IP6PROTO_REGISTER(IPPROTO_IPV4, encap6_input, NULL);
300 IP6PROTO_REGISTER(IPPROTO_IPV6, encap6_input, NULL);
301 IP6PROTO_REGISTER(IPPROTO_ETHERIP, encap6_input, NULL);
302 IP6PROTO_REGISTER(IPPROTO_GRE, encap6_input, NULL);
303 IP6PROTO_REGISTER(IPPROTO_PIM, encap6_input, NULL);
304 #ifdef SCTP /* XXX: has a loadable & static version */
305 IP6PROTO_REGISTER(IPPROTO_SCTP, sctp6_input, sctp6_ctlinput);
306 #endif
307
308 EVENTHANDLER_REGISTER(vm_lowmem, frag6_drain, NULL, LOWMEM_PRI_DEFAULT);
309 EVENTHANDLER_REGISTER(mbuf_lowmem, frag6_drain, NULL,
310 LOWMEM_PRI_DEFAULT);
311
312 netisr_register(&ip6_nh);
313 #ifdef RSS
314 netisr_register(&ip6_direct_nh);
315 #endif
316 }
317 SYSINIT(ip6_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip6_init, NULL);
318
319 int
ip6proto_register(uint8_t proto,ip6proto_input_t input,ip6proto_ctlinput_t ctl)320 ip6proto_register(uint8_t proto, ip6proto_input_t input,
321 ip6proto_ctlinput_t ctl)
322 {
323
324 MPASS(proto > 0);
325
326 if (ip6_protox[proto] == rip6_input) {
327 ip6_protox[proto] = input;
328 ip6_ctlprotox[proto] = ctl;
329 return (0);
330 } else
331 return (EEXIST);
332 }
333
334 int
ip6proto_unregister(uint8_t proto)335 ip6proto_unregister(uint8_t proto)
336 {
337
338 MPASS(proto > 0);
339
340 if (ip6_protox[proto] != rip6_input) {
341 ip6_protox[proto] = rip6_input;
342 ip6_ctlprotox[proto] = rip6_ctlinput;
343 return (0);
344 } else
345 return (ENOENT);
346 }
347
348 #ifdef VIMAGE
349 static void
ip6_destroy(void * unused __unused)350 ip6_destroy(void *unused __unused)
351 {
352 struct ifaddr *ifa, *nifa;
353 struct ifnet *ifp;
354 int error;
355
356 #ifdef RSS
357 netisr_unregister_vnet(&ip6_direct_nh);
358 #endif
359 netisr_unregister_vnet(&ip6_nh);
360
361 pfil_head_unregister(V_inet6_pfil_head);
362 error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET6]);
363 if (error != 0) {
364 printf("%s: WARNING: unable to deregister input helper hook "
365 "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET6: "
366 "error %d returned\n", __func__, error);
367 }
368 error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET6]);
369 if (error != 0) {
370 printf("%s: WARNING: unable to deregister output helper hook "
371 "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET6: "
372 "error %d returned\n", __func__, error);
373 }
374
375 /* Cleanup addresses. */
376 IFNET_RLOCK();
377 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
378 /* Cannot lock here - lock recursion. */
379 /* IF_ADDR_LOCK(ifp); */
380 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) {
381 if (ifa->ifa_addr->sa_family != AF_INET6)
382 continue;
383 in6_purgeaddr(ifa);
384 }
385 /* IF_ADDR_UNLOCK(ifp); */
386 in6_ifdetach_destroy(ifp);
387 mld_domifdetach(ifp);
388 }
389 IFNET_RUNLOCK();
390
391 /* Make sure any routes are gone as well. */
392 rib_flush_routes_family(AF_INET6);
393
394 frag6_destroy();
395 nd6_destroy();
396 in6_ifattach_destroy();
397
398 hashdestroy(V_in6_ifaddrhashtbl, M_IFADDR, V_in6_ifaddrhmask);
399 }
400
401 VNET_SYSUNINIT(inet6, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip6_destroy, NULL);
402 #endif
403
404 static int
ip6_input_hbh(struct mbuf ** mp,uint32_t * plen,uint32_t * rtalert,int * off,int * nxt,int * ours)405 ip6_input_hbh(struct mbuf **mp, uint32_t *plen, uint32_t *rtalert, int *off,
406 int *nxt, int *ours)
407 {
408 struct mbuf *m;
409 struct ip6_hdr *ip6;
410 struct ip6_hbh *hbh;
411
412 if (ip6_hopopts_input(plen, rtalert, mp, off)) {
413 #if 0 /*touches NULL pointer*/
414 in6_ifstat_inc((*mp)->m_pkthdr.rcvif, ifs6_in_discard);
415 #endif
416 goto out; /* m have already been freed */
417 }
418
419 /* adjust pointer */
420 m = *mp;
421 ip6 = mtod(m, struct ip6_hdr *);
422
423 /*
424 * if the payload length field is 0 and the next header field
425 * indicates Hop-by-Hop Options header, then a Jumbo Payload
426 * option MUST be included.
427 */
428 if (ip6->ip6_plen == 0 && *plen == 0) {
429 /*
430 * Note that if a valid jumbo payload option is
431 * contained, ip6_hopopts_input() must set a valid
432 * (non-zero) payload length to the variable plen.
433 */
434 IP6STAT_INC(ip6s_badoptions);
435 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
436 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
437 icmp6_error(m, ICMP6_PARAM_PROB,
438 ICMP6_PARAMPROB_HEADER,
439 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
440 goto out;
441 }
442 /* ip6_hopopts_input() ensures that mbuf is contiguous */
443 hbh = (struct ip6_hbh *)(ip6 + 1);
444 *nxt = hbh->ip6h_nxt;
445
446 /*
447 * If we are acting as a router and the packet contains a
448 * router alert option, see if we know the option value.
449 * Currently, we only support the option value for MLD, in which
450 * case we should pass the packet to the multicast routing
451 * daemon.
452 */
453 if (*rtalert != ~0) {
454 switch (*rtalert) {
455 case IP6OPT_RTALERT_MLD:
456 if (V_ip6_forwarding)
457 *ours = 1;
458 break;
459 default:
460 /*
461 * RFC2711 requires unrecognized values must be
462 * silently ignored.
463 */
464 break;
465 }
466 }
467
468 return (0);
469
470 out:
471 return (1);
472 }
473
474 #ifdef RSS
475 /*
476 * IPv6 direct input routine.
477 *
478 * This is called when reinjecting completed fragments where
479 * all of the previous checking and book-keeping has been done.
480 */
481 void
ip6_direct_input(struct mbuf * m)482 ip6_direct_input(struct mbuf *m)
483 {
484 int off, nxt;
485 int nest;
486 struct m_tag *mtag;
487 struct ip6_direct_ctx *ip6dc;
488
489 mtag = m_tag_locate(m, MTAG_ABI_IPV6, IPV6_TAG_DIRECT, NULL);
490 KASSERT(mtag != NULL, ("Reinjected packet w/o direct ctx tag!"));
491
492 ip6dc = (struct ip6_direct_ctx *)(mtag + 1);
493 nxt = ip6dc->ip6dc_nxt;
494 off = ip6dc->ip6dc_off;
495
496 nest = 0;
497
498 m_tag_delete(m, mtag);
499
500 while (nxt != IPPROTO_DONE) {
501 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
502 IP6STAT_INC(ip6s_toomanyhdr);
503 goto bad;
504 }
505
506 /*
507 * protection against faulty packet - there should be
508 * more sanity checks in header chain processing.
509 */
510 if (m->m_pkthdr.len < off) {
511 IP6STAT_INC(ip6s_tooshort);
512 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
513 goto bad;
514 }
515
516 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
517 if (IPSEC_ENABLED(ipv6)) {
518 if (IPSEC_INPUT(ipv6, m, off, nxt) != 0)
519 return;
520 }
521 #endif /* IPSEC */
522
523 nxt = ip6_protox[nxt](&m, &off, nxt);
524 }
525 return;
526 bad:
527 m_freem(m);
528 }
529 #endif
530
531 void
ip6_input(struct mbuf * m)532 ip6_input(struct mbuf *m)
533 {
534 struct in6_addr odst;
535 struct ip6_hdr *ip6;
536 struct in6_ifaddr *ia;
537 struct ifnet *rcvif;
538 u_int32_t plen;
539 u_int32_t rtalert = ~0;
540 int off = sizeof(struct ip6_hdr), nest;
541 int nxt, ours = 0;
542 int srcrt = 0;
543
544 /*
545 * Drop the packet if IPv6 operation is disabled on the interface.
546 */
547 rcvif = m->m_pkthdr.rcvif;
548 if ((ND_IFINFO(rcvif)->flags & ND6_IFF_IFDISABLED))
549 goto bad;
550
551 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
552 /*
553 * should the inner packet be considered authentic?
554 * see comment in ah4_input().
555 * NB: m cannot be NULL when passed to the input routine
556 */
557
558 m->m_flags &= ~M_AUTHIPHDR;
559 m->m_flags &= ~M_AUTHIPDGM;
560
561 #endif /* IPSEC */
562
563 if (m->m_flags & M_FASTFWD_OURS) {
564 /*
565 * Firewall changed destination to local.
566 */
567 ip6 = mtod(m, struct ip6_hdr *);
568 goto passin;
569 }
570
571 /*
572 * mbuf statistics
573 */
574 if (m->m_flags & M_EXT) {
575 if (m->m_next)
576 IP6STAT_INC(ip6s_mext2m);
577 else
578 IP6STAT_INC(ip6s_mext1);
579 } else {
580 if (m->m_next) {
581 struct ifnet *ifp = (m->m_flags & M_LOOP) ? V_loif : rcvif;
582 int ifindex = ifp->if_index;
583 if (ifindex >= IP6S_M2MMAX)
584 ifindex = 0;
585 IP6STAT_INC2(ip6s_m2m, ifindex);
586 } else
587 IP6STAT_INC(ip6s_m1);
588 }
589
590 in6_ifstat_inc(rcvif, ifs6_in_receive);
591 IP6STAT_INC(ip6s_total);
592
593 /*
594 * L2 bridge code and some other code can return mbuf chain
595 * that does not conform to KAME requirement. too bad.
596 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
597 */
598 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
599 struct mbuf *n;
600
601 if (m->m_pkthdr.len > MHLEN)
602 n = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
603 else
604 n = m_gethdr(M_NOWAIT, MT_DATA);
605 if (n == NULL)
606 goto bad;
607
608 m_move_pkthdr(n, m);
609 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
610 n->m_len = n->m_pkthdr.len;
611 m_freem(m);
612 m = n;
613 }
614 if (m->m_len < sizeof(struct ip6_hdr)) {
615 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
616 IP6STAT_INC(ip6s_toosmall);
617 in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
618 goto bad;
619 }
620 }
621
622 ip6 = mtod(m, struct ip6_hdr *);
623 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
624 IP6STAT_INC(ip6s_badvers);
625 in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
626 goto bad;
627 }
628
629 IP6STAT_INC2(ip6s_nxthist, ip6->ip6_nxt);
630 IP_PROBE(receive, NULL, NULL, ip6, rcvif, NULL, ip6);
631
632 /*
633 * Check against address spoofing/corruption. The unspecified address
634 * is checked further below.
635 */
636 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
637 /*
638 * XXX: "badscope" is not very suitable for a multicast source.
639 */
640 IP6STAT_INC(ip6s_badscope);
641 in6_ifstat_inc(rcvif, ifs6_in_addrerr);
642 goto bad;
643 }
644 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
645 !(m->m_flags & M_LOOP)) {
646 /*
647 * In this case, the packet should come from the loopback
648 * interface. However, we cannot just check the if_flags,
649 * because ip6_mloopback() passes the "actual" interface
650 * as the outgoing/incoming interface.
651 */
652 IP6STAT_INC(ip6s_badscope);
653 in6_ifstat_inc(rcvif, ifs6_in_addrerr);
654 goto bad;
655 }
656 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
657 IPV6_ADDR_MC_SCOPE(&ip6->ip6_dst) == 0) {
658 /*
659 * RFC4291 2.7:
660 * Nodes must not originate a packet to a multicast address
661 * whose scop field contains the reserved value 0; if such
662 * a packet is received, it must be silently dropped.
663 */
664 IP6STAT_INC(ip6s_badscope);
665 in6_ifstat_inc(rcvif, ifs6_in_addrerr);
666 goto bad;
667 }
668 /*
669 * The following check is not documented in specs. A malicious
670 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
671 * and bypass security checks (act as if it was from 127.0.0.1 by using
672 * IPv6 src ::ffff:127.0.0.1). Be cautious.
673 *
674 * We have supported IPv6-only kernels for a few years and this issue
675 * has not come up. The world seems to move mostly towards not using
676 * v4mapped on the wire, so it makes sense for us to keep rejecting
677 * any such packets.
678 */
679 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
680 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
681 IP6STAT_INC(ip6s_badscope);
682 in6_ifstat_inc(rcvif, ifs6_in_addrerr);
683 goto bad;
684 }
685 #if 0
686 /*
687 * Reject packets with IPv4 compatible addresses (auto tunnel).
688 *
689 * The code forbids auto tunnel relay case in RFC1933 (the check is
690 * stronger than RFC1933). We may want to re-enable it if mech-xx
691 * is revised to forbid relaying case.
692 */
693 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
694 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
695 IP6STAT_INC(ip6s_badscope);
696 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
697 goto bad;
698 }
699 #endif
700 /*
701 * Try to forward the packet, but if we fail continue.
702 * ip6_tryforward() does not generate redirects, so fall
703 * through to normal processing if redirects are required.
704 * ip6_tryforward() does inbound and outbound packet firewall
705 * processing. If firewall has decided that destination becomes
706 * our local address, it sets M_FASTFWD_OURS flag. In this
707 * case skip another inbound firewall processing and update
708 * ip6 pointer.
709 */
710 if (V_ip6_forwarding != 0 && V_ip6_sendredirects == 0
711 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
712 && (!IPSEC_ENABLED(ipv6) ||
713 IPSEC_CAPS(ipv6, m, IPSEC_CAP_OPERABLE) == 0)
714 #endif
715 ) {
716 if ((m = ip6_tryforward(m)) == NULL)
717 return;
718 if (m->m_flags & M_FASTFWD_OURS) {
719 ip6 = mtod(m, struct ip6_hdr *);
720 goto passin;
721 }
722 }
723 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
724 /*
725 * Bypass packet filtering for packets previously handled by IPsec.
726 */
727 if (IPSEC_ENABLED(ipv6) &&
728 IPSEC_CAPS(ipv6, m, IPSEC_CAP_BYPASS_FILTER) != 0)
729 goto passin;
730 #endif
731 /*
732 * Run through list of hooks for input packets.
733 *
734 * NB: Beware of the destination address changing
735 * (e.g. by NAT rewriting). When this happens,
736 * tell ip6_forward to do the right thing.
737 */
738
739 /* Jump over all PFIL processing if hooks are not active. */
740 if (!PFIL_HOOKED_IN(V_inet6_pfil_head))
741 goto passin;
742
743 odst = ip6->ip6_dst;
744 if (pfil_mbuf_in(V_inet6_pfil_head, &m, m->m_pkthdr.rcvif,
745 NULL) != PFIL_PASS)
746 return;
747 ip6 = mtod(m, struct ip6_hdr *);
748 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
749 if ((m->m_flags & (M_IP6_NEXTHOP | M_FASTFWD_OURS)) == M_IP6_NEXTHOP &&
750 m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
751 /*
752 * Directly ship the packet on. This allows forwarding
753 * packets originally destined to us to some other directly
754 * connected host.
755 */
756 ip6_forward(m, 1);
757 return;
758 }
759
760 passin:
761 /*
762 * The check is deferred to here to give firewalls a chance to block
763 * (and log) such packets. ip6_tryforward() will not process such
764 * packets.
765 */
766 if (__predict_false(IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst))) {
767 IP6STAT_INC(ip6s_badscope);
768 in6_ifstat_inc(rcvif, ifs6_in_addrerr);
769 goto bad;
770 }
771
772 /*
773 * Disambiguate address scope zones (if there is ambiguity).
774 * We first make sure that the original source or destination address
775 * is not in our internal form for scoped addresses. Such addresses
776 * are not necessarily invalid spec-wise, but we cannot accept them due
777 * to the usage conflict.
778 * in6_setscope() then also checks and rejects the cases where src or
779 * dst are the loopback address and the receiving interface
780 * is not loopback.
781 */
782 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
783 IP6STAT_INC(ip6s_badscope); /* XXX */
784 goto bad;
785 }
786 if (in6_setscope(&ip6->ip6_src, rcvif, NULL) ||
787 in6_setscope(&ip6->ip6_dst, rcvif, NULL)) {
788 IP6STAT_INC(ip6s_badscope);
789 goto bad;
790 }
791 if (m->m_flags & M_FASTFWD_OURS) {
792 m->m_flags &= ~M_FASTFWD_OURS;
793 ours = 1;
794 goto hbhcheck;
795 }
796 /*
797 * Multicast check. Assume packet is for us to avoid
798 * prematurely taking locks.
799 */
800 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
801 ours = 1;
802 in6_ifstat_inc(rcvif, ifs6_in_mcast);
803 goto hbhcheck;
804 }
805 /*
806 * Unicast check
807 * XXX: For now we keep link-local IPv6 addresses with embedded
808 * scope zone id, therefore we use zero zoneid here.
809 */
810 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
811 if (ia != NULL) {
812 if (ia->ia6_flags & IN6_IFF_NOTREADY) {
813 char ip6bufs[INET6_ADDRSTRLEN];
814 char ip6bufd[INET6_ADDRSTRLEN];
815 /* address is not ready, so discard the packet. */
816 nd6log((LOG_INFO,
817 "ip6_input: packet to an unready address %s->%s\n",
818 ip6_sprintf(ip6bufs, &ip6->ip6_src),
819 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
820 goto bad;
821 }
822 if (V_ip6_sav && !(m->m_flags & M_LOOP) &&
823 __predict_false(in6_localip_fib(&ip6->ip6_src,
824 rcvif->if_fib))) {
825 IP6STAT_INC(ip6s_badscope); /* XXX */
826 goto bad;
827 }
828 /* Count the packet in the ip address stats */
829 counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
830 counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len);
831 ours = 1;
832 goto hbhcheck;
833 }
834
835 /*
836 * Now there is no reason to process the packet if it's not our own
837 * and we're not a router.
838 */
839 if (!V_ip6_forwarding) {
840 IP6STAT_INC(ip6s_cantforward);
841 goto bad;
842 }
843
844 hbhcheck:
845 /*
846 * Process Hop-by-Hop options header if it's contained.
847 * m may be modified in ip6_hopopts_input().
848 * If a JumboPayload option is included, plen will also be modified.
849 */
850 plen = (u_int32_t)ntohs(ip6->ip6_plen);
851 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
852 if (ip6_input_hbh(&m, &plen, &rtalert, &off, &nxt, &ours) != 0)
853 return;
854 } else
855 nxt = ip6->ip6_nxt;
856
857 /*
858 * Use mbuf flags to propagate Router Alert option to
859 * ICMPv6 layer, as hop-by-hop options have been stripped.
860 */
861 if (rtalert != ~0)
862 m->m_flags |= M_RTALERT_MLD;
863
864 /*
865 * Check that the amount of data in the buffers
866 * is as at least much as the IPv6 header would have us expect.
867 * Trim mbufs if longer than we expect.
868 * Drop packet if shorter than we expect.
869 */
870 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
871 IP6STAT_INC(ip6s_tooshort);
872 in6_ifstat_inc(rcvif, ifs6_in_truncated);
873 goto bad;
874 }
875 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
876 if (m->m_len == m->m_pkthdr.len) {
877 m->m_len = sizeof(struct ip6_hdr) + plen;
878 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
879 } else
880 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
881 }
882
883 /*
884 * Forward if desirable.
885 */
886 if (V_ip6_mrouter &&
887 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
888 /*
889 * If we are acting as a multicast router, all
890 * incoming multicast packets are passed to the
891 * kernel-level multicast forwarding function.
892 * The packet is returned (relatively) intact; if
893 * ip6_mforward() returns a non-zero value, the packet
894 * must be discarded, else it may be accepted below.
895 *
896 * XXX TODO: Check hlim and multicast scope here to avoid
897 * unnecessarily calling into ip6_mforward().
898 */
899 if (ip6_mforward && ip6_mforward(ip6, rcvif, m)) {
900 IP6STAT_INC(ip6s_cantforward);
901 goto bad;
902 }
903 } else if (!ours) {
904 ip6_forward(m, srcrt);
905 return;
906 }
907
908 /*
909 * We are going to ship the packet to the local protocol stack. Call the
910 * filter again for this 'output' action, allowing redirect-like rules
911 * to adjust the source address.
912 */
913 if (PFIL_HOOKED_OUT(V_inet6_local_pfil_head)) {
914 if (pfil_mbuf_out(V_inet6_local_pfil_head, &m, V_loif, NULL) !=
915 PFIL_PASS)
916 return;
917 ip6 = mtod(m, struct ip6_hdr *);
918 }
919
920 /*
921 * Tell launch routine the next header
922 */
923 IP6STAT_INC(ip6s_delivered);
924 in6_ifstat_inc(rcvif, ifs6_in_deliver);
925 nest = 0;
926
927 while (nxt != IPPROTO_DONE) {
928 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
929 IP6STAT_INC(ip6s_toomanyhdr);
930 goto bad;
931 }
932
933 /*
934 * protection against faulty packet - there should be
935 * more sanity checks in header chain processing.
936 */
937 if (m->m_pkthdr.len < off) {
938 IP6STAT_INC(ip6s_tooshort);
939 in6_ifstat_inc(rcvif, ifs6_in_truncated);
940 goto bad;
941 }
942
943 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
944 if (IPSEC_ENABLED(ipv6)) {
945 if (IPSEC_INPUT(ipv6, m, off, nxt) != 0)
946 return;
947 }
948 #endif /* IPSEC */
949
950 nxt = ip6_protox[nxt](&m, &off, nxt);
951 }
952 return;
953 bad:
954 in6_ifstat_inc(rcvif, ifs6_in_discard);
955 if (m != NULL)
956 m_freem(m);
957 }
958
959 /*
960 * Hop-by-Hop options header processing. If a valid jumbo payload option is
961 * included, the real payload length will be stored in plenp.
962 *
963 * rtalertp - XXX: should be stored more smart way
964 */
965 static int
ip6_hopopts_input(u_int32_t * plenp,u_int32_t * rtalertp,struct mbuf ** mp,int * offp)966 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
967 struct mbuf **mp, int *offp)
968 {
969 struct mbuf *m = *mp;
970 int off = *offp, hbhlen;
971 struct ip6_hbh *hbh;
972
973 /* validation of the length of the header */
974 if (m->m_len < off + sizeof(*hbh)) {
975 m = m_pullup(m, off + sizeof(*hbh));
976 if (m == NULL) {
977 IP6STAT_INC(ip6s_exthdrtoolong);
978 *mp = NULL;
979 return (-1);
980 }
981 }
982 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
983 hbhlen = (hbh->ip6h_len + 1) << 3;
984
985 if (m->m_len < off + hbhlen) {
986 m = m_pullup(m, off + hbhlen);
987 if (m == NULL) {
988 IP6STAT_INC(ip6s_exthdrtoolong);
989 *mp = NULL;
990 return (-1);
991 }
992 }
993 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
994 off += hbhlen;
995 hbhlen -= sizeof(struct ip6_hbh);
996 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
997 hbhlen, rtalertp, plenp) < 0) {
998 *mp = NULL;
999 return (-1);
1000 }
1001
1002 *offp = off;
1003 *mp = m;
1004 return (0);
1005 }
1006
1007 /*
1008 * Search header for all Hop-by-hop options and process each option.
1009 * This function is separate from ip6_hopopts_input() in order to
1010 * handle a case where the sending node itself process its hop-by-hop
1011 * options header. In such a case, the function is called from ip6_output().
1012 *
1013 * The function assumes that hbh header is located right after the IPv6 header
1014 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
1015 * opthead + hbhlen is located in contiguous memory region.
1016 */
1017 int
ip6_process_hopopts(struct mbuf * m,u_int8_t * opthead,int hbhlen,u_int32_t * rtalertp,u_int32_t * plenp)1018 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
1019 u_int32_t *rtalertp, u_int32_t *plenp)
1020 {
1021 struct ip6_hdr *ip6;
1022 int optlen = 0;
1023 u_int8_t *opt = opthead;
1024 u_int16_t rtalert_val;
1025 u_int32_t jumboplen;
1026 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
1027
1028 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
1029 switch (*opt) {
1030 case IP6OPT_PAD1:
1031 optlen = 1;
1032 break;
1033 case IP6OPT_PADN:
1034 if (hbhlen < IP6OPT_MINLEN) {
1035 IP6STAT_INC(ip6s_toosmall);
1036 goto bad;
1037 }
1038 optlen = *(opt + 1) + 2;
1039 break;
1040 case IP6OPT_ROUTER_ALERT:
1041 /* XXX may need check for alignment */
1042 if (hbhlen < IP6OPT_RTALERT_LEN) {
1043 IP6STAT_INC(ip6s_toosmall);
1044 goto bad;
1045 }
1046 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
1047 /* XXX stat */
1048 icmp6_error(m, ICMP6_PARAM_PROB,
1049 ICMP6_PARAMPROB_HEADER,
1050 erroff + opt + 1 - opthead);
1051 return (-1);
1052 }
1053 optlen = IP6OPT_RTALERT_LEN;
1054 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
1055 *rtalertp = ntohs(rtalert_val);
1056 break;
1057 case IP6OPT_JUMBO:
1058 /* XXX may need check for alignment */
1059 if (hbhlen < IP6OPT_JUMBO_LEN) {
1060 IP6STAT_INC(ip6s_toosmall);
1061 goto bad;
1062 }
1063 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
1064 /* XXX stat */
1065 icmp6_error(m, ICMP6_PARAM_PROB,
1066 ICMP6_PARAMPROB_HEADER,
1067 erroff + opt + 1 - opthead);
1068 return (-1);
1069 }
1070 optlen = IP6OPT_JUMBO_LEN;
1071
1072 /*
1073 * IPv6 packets that have non 0 payload length
1074 * must not contain a jumbo payload option.
1075 */
1076 ip6 = mtod(m, struct ip6_hdr *);
1077 if (ip6->ip6_plen) {
1078 IP6STAT_INC(ip6s_badoptions);
1079 icmp6_error(m, ICMP6_PARAM_PROB,
1080 ICMP6_PARAMPROB_HEADER,
1081 erroff + opt - opthead);
1082 return (-1);
1083 }
1084
1085 /*
1086 * We may see jumbolen in unaligned location, so
1087 * we'd need to perform bcopy().
1088 */
1089 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1090 jumboplen = (u_int32_t)htonl(jumboplen);
1091
1092 #if 1
1093 /*
1094 * if there are multiple jumbo payload options,
1095 * *plenp will be non-zero and the packet will be
1096 * rejected.
1097 * the behavior may need some debate in ipngwg -
1098 * multiple options does not make sense, however,
1099 * there's no explicit mention in specification.
1100 */
1101 if (*plenp != 0) {
1102 IP6STAT_INC(ip6s_badoptions);
1103 icmp6_error(m, ICMP6_PARAM_PROB,
1104 ICMP6_PARAMPROB_HEADER,
1105 erroff + opt + 2 - opthead);
1106 return (-1);
1107 }
1108 #endif
1109
1110 /*
1111 * jumbo payload length must be larger than 65535.
1112 */
1113 if (jumboplen <= IPV6_MAXPACKET) {
1114 IP6STAT_INC(ip6s_badoptions);
1115 icmp6_error(m, ICMP6_PARAM_PROB,
1116 ICMP6_PARAMPROB_HEADER,
1117 erroff + opt + 2 - opthead);
1118 return (-1);
1119 }
1120 *plenp = jumboplen;
1121
1122 break;
1123 default: /* unknown option */
1124 if (hbhlen < IP6OPT_MINLEN) {
1125 IP6STAT_INC(ip6s_toosmall);
1126 goto bad;
1127 }
1128 optlen = ip6_unknown_opt(opt, m,
1129 erroff + opt - opthead);
1130 if (optlen == -1)
1131 return (-1);
1132 optlen += 2;
1133 break;
1134 }
1135 }
1136
1137 return (0);
1138
1139 bad:
1140 m_freem(m);
1141 return (-1);
1142 }
1143
1144 /*
1145 * Unknown option processing.
1146 * The third argument `off' is the offset from the IPv6 header to the option,
1147 * which is necessary if the IPv6 header the and option header and IPv6 header
1148 * is not contiguous in order to return an ICMPv6 error.
1149 */
1150 int
ip6_unknown_opt(u_int8_t * optp,struct mbuf * m,int off)1151 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1152 {
1153 struct ip6_hdr *ip6;
1154
1155 switch (IP6OPT_TYPE(*optp)) {
1156 case IP6OPT_TYPE_SKIP: /* ignore the option */
1157 return ((int)*(optp + 1));
1158 case IP6OPT_TYPE_DISCARD: /* silently discard */
1159 m_freem(m);
1160 return (-1);
1161 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1162 IP6STAT_INC(ip6s_badoptions);
1163 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1164 return (-1);
1165 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1166 IP6STAT_INC(ip6s_badoptions);
1167 ip6 = mtod(m, struct ip6_hdr *);
1168 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1169 (m->m_flags & (M_BCAST|M_MCAST)))
1170 m_freem(m);
1171 else
1172 icmp6_error(m, ICMP6_PARAM_PROB,
1173 ICMP6_PARAMPROB_OPTION, off);
1174 return (-1);
1175 }
1176
1177 m_freem(m); /* XXX: NOTREACHED */
1178 return (-1);
1179 }
1180
1181 /*
1182 * Create the "control" list for this pcb.
1183 * These functions will not modify mbuf chain at all.
1184 *
1185 * The routine will be called from upper layer handlers like tcp6_input().
1186 * Thus the routine assumes that the caller (tcp6_input) have already
1187 * called m_pullup() and all the extension headers are located in the
1188 * very first mbuf on the mbuf chain.
1189 *
1190 * ip6_savecontrol_v4 will handle those options that are possible to be
1191 * set on a v4-mapped socket.
1192 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1193 * options and handle the v6-only ones itself.
1194 */
1195 struct mbuf **
ip6_savecontrol_v4(struct inpcb * inp,struct mbuf * m,struct mbuf ** mp,int * v4only)1196 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1197 int *v4only)
1198 {
1199 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1200
1201 #if defined(SO_TIMESTAMP) && defined(SO_BINTIME)
1202 if ((inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) != 0) {
1203 union {
1204 struct timeval tv;
1205 struct bintime bt;
1206 struct timespec ts;
1207 } t;
1208 struct bintime boottimebin, bt1;
1209 struct timespec ts1;
1210 int ts_clock;
1211 bool stamped;
1212
1213 ts_clock = inp->inp_socket->so_ts_clock;
1214 stamped = false;
1215
1216 /*
1217 * Handle BINTIME first. We create the same output options
1218 * for both SO_BINTIME and the case where SO_TIMESTAMP is
1219 * set with the timestamp clock set to SO_TS_BINTIME.
1220 */
1221 if ((inp->inp_socket->so_options & SO_BINTIME) != 0 ||
1222 ts_clock == SO_TS_BINTIME) {
1223 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1224 M_TSTMP)) {
1225 mbuf_tstmp2timespec(m, &ts1);
1226 timespec2bintime(&ts1, &t.bt);
1227 getboottimebin(&boottimebin);
1228 bintime_add(&t.bt, &boottimebin);
1229 } else {
1230 bintime(&t.bt);
1231 }
1232 *mp = sbcreatecontrol(&t.bt, sizeof(t.bt), SCM_BINTIME,
1233 SOL_SOCKET, M_NOWAIT);
1234 if (*mp != NULL) {
1235 mp = &(*mp)->m_next;
1236 stamped = true;
1237 }
1238
1239 /*
1240 * Suppress other timestamps if SO_TIMESTAMP is not
1241 * set.
1242 */
1243 if ((inp->inp_socket->so_options & SO_TIMESTAMP) == 0)
1244 ts_clock = SO_TS_BINTIME;
1245 }
1246
1247 switch (ts_clock) {
1248 case SO_TS_REALTIME_MICRO:
1249 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1250 M_TSTMP)) {
1251 mbuf_tstmp2timespec(m, &ts1);
1252 timespec2bintime(&ts1, &bt1);
1253 getboottimebin(&boottimebin);
1254 bintime_add(&bt1, &boottimebin);
1255 bintime2timeval(&bt1, &t.tv);
1256 } else {
1257 microtime(&t.tv);
1258 }
1259 *mp = sbcreatecontrol(&t.tv, sizeof(t.tv),
1260 SCM_TIMESTAMP, SOL_SOCKET, M_NOWAIT);
1261 if (*mp != NULL) {
1262 mp = &(*mp)->m_next;
1263 stamped = true;
1264 }
1265 break;
1266
1267 case SO_TS_BINTIME:
1268 break;
1269
1270 case SO_TS_REALTIME:
1271 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1272 M_TSTMP)) {
1273 mbuf_tstmp2timespec(m, &t.ts);
1274 getboottimebin(&boottimebin);
1275 bintime2timespec(&boottimebin, &ts1);
1276 timespecadd(&t.ts, &ts1, &t.ts);
1277 } else {
1278 nanotime(&t.ts);
1279 }
1280 *mp = sbcreatecontrol(&t.ts, sizeof(t.ts),
1281 SCM_REALTIME, SOL_SOCKET, M_NOWAIT);
1282 if (*mp != NULL) {
1283 mp = &(*mp)->m_next;
1284 stamped = true;
1285 }
1286 break;
1287
1288 case SO_TS_MONOTONIC:
1289 if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1290 M_TSTMP))
1291 mbuf_tstmp2timespec(m, &t.ts);
1292 else
1293 nanouptime(&t.ts);
1294 *mp = sbcreatecontrol(&t.ts, sizeof(t.ts),
1295 SCM_MONOTONIC, SOL_SOCKET, M_NOWAIT);
1296 if (*mp != NULL) {
1297 mp = &(*mp)->m_next;
1298 stamped = true;
1299 }
1300 break;
1301
1302 default:
1303 panic("unknown (corrupted) so_ts_clock");
1304 }
1305 if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) ==
1306 (M_PKTHDR | M_TSTMP)) {
1307 struct sock_timestamp_info sti;
1308
1309 bzero(&sti, sizeof(sti));
1310 sti.st_info_flags = ST_INFO_HW;
1311 if ((m->m_flags & M_TSTMP_HPREC) != 0)
1312 sti.st_info_flags |= ST_INFO_HW_HPREC;
1313 *mp = sbcreatecontrol(&sti, sizeof(sti), SCM_TIME_INFO,
1314 SOL_SOCKET, M_NOWAIT);
1315 if (*mp != NULL)
1316 mp = &(*mp)->m_next;
1317 }
1318 }
1319 #endif
1320
1321 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1322 /* RFC 2292 sec. 5 */
1323 if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1324 struct in6_pktinfo pi6;
1325
1326 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1327 #ifdef INET
1328 struct ip *ip;
1329
1330 ip = mtod(m, struct ip *);
1331 pi6.ipi6_addr.s6_addr32[0] = 0;
1332 pi6.ipi6_addr.s6_addr32[1] = 0;
1333 pi6.ipi6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
1334 pi6.ipi6_addr.s6_addr32[3] = ip->ip_dst.s_addr;
1335 #else
1336 /* We won't hit this code */
1337 bzero(&pi6.ipi6_addr, sizeof(struct in6_addr));
1338 #endif
1339 } else {
1340 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1341 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1342 }
1343 pi6.ipi6_ifindex =
1344 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1345
1346 *mp = sbcreatecontrol(&pi6, sizeof(struct in6_pktinfo),
1347 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6,
1348 M_NOWAIT);
1349 if (*mp)
1350 mp = &(*mp)->m_next;
1351 }
1352
1353 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1354 int hlim;
1355
1356 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1357 #ifdef INET
1358 struct ip *ip;
1359
1360 ip = mtod(m, struct ip *);
1361 hlim = ip->ip_ttl;
1362 #else
1363 /* We won't hit this code */
1364 hlim = 0;
1365 #endif
1366 } else {
1367 hlim = ip6->ip6_hlim & 0xff;
1368 }
1369 *mp = sbcreatecontrol(&hlim, sizeof(int),
1370 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1371 IPPROTO_IPV6, M_NOWAIT);
1372 if (*mp)
1373 mp = &(*mp)->m_next;
1374 }
1375
1376 if ((inp->inp_flags & IN6P_TCLASS) != 0) {
1377 int tclass;
1378
1379 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1380 #ifdef INET
1381 struct ip *ip;
1382
1383 ip = mtod(m, struct ip *);
1384 tclass = ip->ip_tos;
1385 #else
1386 /* We won't hit this code */
1387 tclass = 0;
1388 #endif
1389 } else {
1390 u_int32_t flowinfo;
1391
1392 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1393 flowinfo >>= 20;
1394 tclass = flowinfo & 0xff;
1395 }
1396 *mp = sbcreatecontrol(&tclass, sizeof(int), IPV6_TCLASS,
1397 IPPROTO_IPV6, M_NOWAIT);
1398 if (*mp)
1399 mp = &(*mp)->m_next;
1400 }
1401
1402 if (v4only != NULL) {
1403 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1404 *v4only = 1;
1405 } else {
1406 *v4only = 0;
1407 }
1408 }
1409
1410 return (mp);
1411 }
1412
1413 void
ip6_savecontrol(struct inpcb * inp,struct mbuf * m,struct mbuf ** mp)1414 ip6_savecontrol(struct inpcb *inp, struct mbuf *m, struct mbuf **mp)
1415 {
1416 struct ip6_hdr *ip6;
1417 int v4only = 0;
1418
1419 mp = ip6_savecontrol_v4(inp, m, mp, &v4only);
1420 if (v4only)
1421 return;
1422
1423 ip6 = mtod(m, struct ip6_hdr *);
1424 /*
1425 * IPV6_HOPOPTS socket option. Recall that we required super-user
1426 * privilege for the option (see ip6_ctloutput), but it might be too
1427 * strict, since there might be some hop-by-hop options which can be
1428 * returned to normal user.
1429 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1430 */
1431 if ((inp->inp_flags & IN6P_HOPOPTS) != 0) {
1432 /*
1433 * Check if a hop-by-hop options header is contatined in the
1434 * received packet, and if so, store the options as ancillary
1435 * data. Note that a hop-by-hop options header must be
1436 * just after the IPv6 header, which is assured through the
1437 * IPv6 input processing.
1438 */
1439 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1440 struct ip6_hbh *hbh;
1441 u_int hbhlen;
1442
1443 hbh = (struct ip6_hbh *)(ip6 + 1);
1444 hbhlen = (hbh->ip6h_len + 1) << 3;
1445
1446 /*
1447 * XXX: We copy the whole header even if a
1448 * jumbo payload option is included, the option which
1449 * is to be removed before returning according to
1450 * RFC2292.
1451 * Note: this constraint is removed in RFC3542
1452 */
1453 *mp = sbcreatecontrol(hbh, hbhlen,
1454 IS2292(inp, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1455 IPPROTO_IPV6, M_NOWAIT);
1456 if (*mp)
1457 mp = &(*mp)->m_next;
1458 }
1459 }
1460
1461 if ((inp->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1462 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1463
1464 /*
1465 * Search for destination options headers or routing
1466 * header(s) through the header chain, and stores each
1467 * header as ancillary data.
1468 * Note that the order of the headers remains in
1469 * the chain of ancillary data.
1470 */
1471 while (1) { /* is explicit loop prevention necessary? */
1472 struct ip6_ext *ip6e = NULL;
1473 u_int elen;
1474
1475 /*
1476 * if it is not an extension header, don't try to
1477 * pull it from the chain.
1478 */
1479 switch (nxt) {
1480 case IPPROTO_DSTOPTS:
1481 case IPPROTO_ROUTING:
1482 case IPPROTO_HOPOPTS:
1483 case IPPROTO_AH: /* is it possible? */
1484 break;
1485 default:
1486 goto loopend;
1487 }
1488
1489 if (off + sizeof(*ip6e) > m->m_len)
1490 goto loopend;
1491 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1492 if (nxt == IPPROTO_AH)
1493 elen = (ip6e->ip6e_len + 2) << 2;
1494 else
1495 elen = (ip6e->ip6e_len + 1) << 3;
1496 if (off + elen > m->m_len)
1497 goto loopend;
1498
1499 switch (nxt) {
1500 case IPPROTO_DSTOPTS:
1501 if (!(inp->inp_flags & IN6P_DSTOPTS))
1502 break;
1503
1504 *mp = sbcreatecontrol(ip6e, elen,
1505 IS2292(inp, IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1506 IPPROTO_IPV6, M_NOWAIT);
1507 if (*mp)
1508 mp = &(*mp)->m_next;
1509 break;
1510 case IPPROTO_ROUTING:
1511 if (!(inp->inp_flags & IN6P_RTHDR))
1512 break;
1513
1514 *mp = sbcreatecontrol(ip6e, elen,
1515 IS2292(inp, IPV6_2292RTHDR, IPV6_RTHDR),
1516 IPPROTO_IPV6, M_NOWAIT);
1517 if (*mp)
1518 mp = &(*mp)->m_next;
1519 break;
1520 case IPPROTO_HOPOPTS:
1521 case IPPROTO_AH: /* is it possible? */
1522 break;
1523
1524 default:
1525 /*
1526 * other cases have been filtered in the above.
1527 * none will visit this case. here we supply
1528 * the code just in case (nxt overwritten or
1529 * other cases).
1530 */
1531 goto loopend;
1532 }
1533
1534 /* proceed with the next header. */
1535 off += elen;
1536 nxt = ip6e->ip6e_nxt;
1537 ip6e = NULL;
1538 }
1539 loopend:
1540 ;
1541 }
1542
1543 if (inp->inp_flags2 & INP_RECVFLOWID) {
1544 uint32_t flowid, flow_type;
1545
1546 flowid = m->m_pkthdr.flowid;
1547 flow_type = M_HASHTYPE_GET(m);
1548
1549 /*
1550 * XXX should handle the failure of one or the
1551 * other - don't populate both?
1552 */
1553 *mp = sbcreatecontrol(&flowid, sizeof(uint32_t), IPV6_FLOWID,
1554 IPPROTO_IPV6, M_NOWAIT);
1555 if (*mp)
1556 mp = &(*mp)->m_next;
1557 *mp = sbcreatecontrol(&flow_type, sizeof(uint32_t),
1558 IPV6_FLOWTYPE, IPPROTO_IPV6, M_NOWAIT);
1559 if (*mp)
1560 mp = &(*mp)->m_next;
1561 }
1562
1563 #ifdef RSS
1564 if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1565 uint32_t flowid, flow_type;
1566 uint32_t rss_bucketid;
1567
1568 flowid = m->m_pkthdr.flowid;
1569 flow_type = M_HASHTYPE_GET(m);
1570
1571 if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1572 *mp = sbcreatecontrol(&rss_bucketid, sizeof(uint32_t),
1573 IPV6_RSSBUCKETID, IPPROTO_IPV6, M_NOWAIT);
1574 if (*mp)
1575 mp = &(*mp)->m_next;
1576 }
1577 }
1578 #endif
1579
1580 }
1581 #undef IS2292
1582
1583 void
ip6_notify_pmtu(struct inpcb * inp,struct sockaddr_in6 * dst,u_int32_t mtu)1584 ip6_notify_pmtu(struct inpcb *inp, struct sockaddr_in6 *dst, u_int32_t mtu)
1585 {
1586 struct socket *so;
1587 struct mbuf *m_mtu;
1588 struct ip6_mtuinfo mtuctl;
1589
1590 KASSERT(inp != NULL, ("%s: inp == NULL", __func__));
1591 /*
1592 * Notify the error by sending IPV6_PATHMTU ancillary data if
1593 * application wanted to know the MTU value.
1594 * NOTE: we notify disconnected sockets, because some udp
1595 * applications keep sending sockets disconnected.
1596 * NOTE: our implementation doesn't notify connected sockets that has
1597 * foreign address that is different than given destination addresses
1598 * (this is permitted by RFC 3542).
1599 */
1600 if ((inp->inp_flags & IN6P_MTU) == 0 || (
1601 !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1602 !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &dst->sin6_addr)))
1603 return;
1604
1605 mtuctl.ip6m_mtu = mtu;
1606 mtuctl.ip6m_addr = *dst;
1607 if (sa6_recoverscope(&mtuctl.ip6m_addr))
1608 return;
1609
1610 if ((m_mtu = sbcreatecontrol(&mtuctl, sizeof(mtuctl), IPV6_PATHMTU,
1611 IPPROTO_IPV6, M_NOWAIT)) == NULL)
1612 return;
1613
1614 so = inp->inp_socket;
1615 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1616 == 0) {
1617 soroverflow(so);
1618 m_freem(m_mtu);
1619 /* XXX: should count statistics */
1620 } else
1621 sorwakeup(so);
1622 }
1623
1624 /*
1625 * Get pointer to the previous header followed by the header
1626 * currently processed.
1627 */
1628 int
ip6_get_prevhdr(const struct mbuf * m,int off)1629 ip6_get_prevhdr(const struct mbuf *m, int off)
1630 {
1631 struct ip6_ext ip6e;
1632 struct ip6_hdr *ip6;
1633 int len, nlen, nxt;
1634
1635 if (off == sizeof(struct ip6_hdr))
1636 return (offsetof(struct ip6_hdr, ip6_nxt));
1637 if (off < sizeof(struct ip6_hdr))
1638 panic("%s: off < sizeof(struct ip6_hdr)", __func__);
1639
1640 ip6 = mtod(m, struct ip6_hdr *);
1641 nxt = ip6->ip6_nxt;
1642 len = sizeof(struct ip6_hdr);
1643 nlen = 0;
1644 while (len < off) {
1645 m_copydata(m, len, sizeof(ip6e), (caddr_t)&ip6e);
1646 switch (nxt) {
1647 case IPPROTO_FRAGMENT:
1648 nlen = sizeof(struct ip6_frag);
1649 break;
1650 case IPPROTO_AH:
1651 nlen = (ip6e.ip6e_len + 2) << 2;
1652 break;
1653 default:
1654 nlen = (ip6e.ip6e_len + 1) << 3;
1655 }
1656 len += nlen;
1657 nxt = ip6e.ip6e_nxt;
1658 }
1659 return (len - nlen);
1660 }
1661
1662 /*
1663 * get next header offset. m will be retained.
1664 */
1665 int
ip6_nexthdr(const struct mbuf * m,int off,int proto,int * nxtp)1666 ip6_nexthdr(const struct mbuf *m, int off, int proto, int *nxtp)
1667 {
1668 struct ip6_hdr ip6;
1669 struct ip6_ext ip6e;
1670 struct ip6_frag fh;
1671
1672 /* just in case */
1673 if (m == NULL)
1674 panic("ip6_nexthdr: m == NULL");
1675 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1676 return -1;
1677
1678 switch (proto) {
1679 case IPPROTO_IPV6:
1680 if (m->m_pkthdr.len < off + sizeof(ip6))
1681 return -1;
1682 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1683 if (nxtp)
1684 *nxtp = ip6.ip6_nxt;
1685 off += sizeof(ip6);
1686 return off;
1687
1688 case IPPROTO_FRAGMENT:
1689 /*
1690 * terminate parsing if it is not the first fragment,
1691 * it does not make sense to parse through it.
1692 */
1693 if (m->m_pkthdr.len < off + sizeof(fh))
1694 return -1;
1695 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1696 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1697 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1698 return -1;
1699 if (nxtp)
1700 *nxtp = fh.ip6f_nxt;
1701 off += sizeof(struct ip6_frag);
1702 return off;
1703
1704 case IPPROTO_AH:
1705 if (m->m_pkthdr.len < off + sizeof(ip6e))
1706 return -1;
1707 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1708 if (nxtp)
1709 *nxtp = ip6e.ip6e_nxt;
1710 off += (ip6e.ip6e_len + 2) << 2;
1711 return off;
1712
1713 case IPPROTO_HOPOPTS:
1714 case IPPROTO_ROUTING:
1715 case IPPROTO_DSTOPTS:
1716 if (m->m_pkthdr.len < off + sizeof(ip6e))
1717 return -1;
1718 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1719 if (nxtp)
1720 *nxtp = ip6e.ip6e_nxt;
1721 off += (ip6e.ip6e_len + 1) << 3;
1722 return off;
1723
1724 case IPPROTO_NONE:
1725 case IPPROTO_ESP:
1726 case IPPROTO_IPCOMP:
1727 /* give up */
1728 return -1;
1729
1730 default:
1731 return -1;
1732 }
1733
1734 /* NOTREACHED */
1735 }
1736
1737 /*
1738 * get offset for the last header in the chain. m will be kept untainted.
1739 */
1740 int
ip6_lasthdr(const struct mbuf * m,int off,int proto,int * nxtp)1741 ip6_lasthdr(const struct mbuf *m, int off, int proto, int *nxtp)
1742 {
1743 int newoff;
1744 int nxt;
1745
1746 if (!nxtp) {
1747 nxt = -1;
1748 nxtp = &nxt;
1749 }
1750 while (1) {
1751 newoff = ip6_nexthdr(m, off, proto, nxtp);
1752 if (newoff < 0)
1753 return off;
1754 else if (newoff < off)
1755 return -1; /* invalid */
1756 else if (newoff == off)
1757 return newoff;
1758
1759 off = newoff;
1760 proto = *nxtp;
1761 }
1762 }
1763