1 /*        $NetBSD: icmp6.c,v 1.258 2024/07/05 04:31:54 rin Exp $      */
2 /*        $KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $     */
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1988, 1993
35  *        The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *        @(#)ip_icmp.c       8.2 (Berkeley) 1/4/94
62  */
63 
64 #include <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: icmp6.c,v 1.258 2024/07/05 04:31:54 rin Exp $");
66 
67 #ifdef _KERNEL_OPT
68 #include "opt_compat_netbsd.h"
69 #include "opt_inet.h"
70 #include "opt_ipsec.h"
71 #endif
72 
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/kmem.h>
76 #include <sys/mbuf.h>
77 #include <sys/protosw.h>
78 #include <sys/socket.h>
79 #include <sys/socketvar.h>
80 #include <sys/time.h>
81 #include <sys/kernel.h>
82 #include <sys/syslog.h>
83 #include <sys/domain.h>
84 #include <sys/sysctl.h>
85 
86 #include <net/if.h>
87 #include <net/route.h>
88 #include <net/if_dl.h>
89 #include <net/if_types.h>
90 #include <net/nd.h>
91 
92 #include <netinet/in.h>
93 #include <netinet/in_pcb.h>
94 #include <netinet/in_var.h>
95 #include <netinet/ip6.h>
96 #include <netinet/wqinput.h>
97 #include <netinet6/ip6_var.h>
98 #include <netinet6/ip6_private.h>
99 #include <netinet/icmp6.h>
100 #include <netinet6/icmp6_private.h>
101 #include <netinet6/mld6_var.h>
102 #include <netinet6/in6_pcb.h>
103 #include <netinet6/in6_ifattach.h>
104 #include <netinet6/ip6protosw.h>
105 #include <netinet6/nd6.h>
106 #include <netinet6/scope6_var.h>
107 
108 #ifdef IPSEC
109 #include <netipsec/ipsec.h>
110 #include <netipsec/ipsec6.h>
111 #include <netipsec/key.h>
112 #endif
113 
114 #include "faith.h"
115 #if defined(NFAITH) && 0 < NFAITH
116 #include <net/if_faith.h>
117 #endif
118 
119 /* Ensure that non packed structures are the desired size. */
120 __CTASSERT(sizeof(struct icmp6_hdr) == 8);
121 __CTASSERT(sizeof(struct icmp6_nodeinfo) == 16);
122 __CTASSERT(sizeof(struct icmp6_namelookup) == 20);
123 __CTASSERT(sizeof(struct icmp6_router_renum) == 16);
124 
125 __CTASSERT(sizeof(struct nd_router_solicit) == 8);
126 __CTASSERT(sizeof(struct nd_router_advert) == 16);
127 __CTASSERT(sizeof(struct nd_neighbor_solicit) == 24);
128 __CTASSERT(sizeof(struct nd_neighbor_advert) == 24);
129 __CTASSERT(sizeof(struct nd_redirect) == 40);
130 __CTASSERT(sizeof(struct nd_opt_hdr) == 2);
131 __CTASSERT(sizeof(struct nd_opt_route_info) == 8);
132 __CTASSERT(sizeof(struct nd_opt_prefix_info) == 32);
133 __CTASSERT(sizeof(struct nd_opt_rd_hdr) == 8);
134 __CTASSERT(sizeof(struct nd_opt_mtu) == 8);
135 __CTASSERT(sizeof(struct nd_opt_nonce) == 2 + ND_OPT_NONCE_LEN);
136 __CTASSERT(sizeof(struct nd_opt_rdnss) == 8);
137 __CTASSERT(sizeof(struct nd_opt_dnssl) == 8);
138 
139 __CTASSERT(sizeof(struct mld_hdr) == 24);
140 __CTASSERT(sizeof(struct ni_reply_fqdn) == 8);
141 __CTASSERT(sizeof(struct rr_pco_match) == 24);
142 __CTASSERT(sizeof(struct rr_pco_use) == 32);
143 __CTASSERT(sizeof(struct rr_result) == 24);
144 
145 extern struct domain inet6domain;
146 
147 percpu_t *icmp6stat_percpu;
148 
149 extern struct inpcbtable raw6cbtable;
150 extern int icmp6errppslim;
151 static int icmp6errpps_count = 0;
152 static struct timeval icmp6errppslim_last;
153 extern int icmp6_nodeinfo;
154 
155 bool icmp6_dynamic_rt_msg = false;
156 
157 /*
158  * List of callbacks to notify when Path MTU changes are made.
159  */
160 struct icmp6_mtudisc_callback {
161           LIST_ENTRY(icmp6_mtudisc_callback) mc_list;
162           void (*mc_func)(struct in6_addr *);
163 };
164 
165 LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks =
166     LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks);
167 
168 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
169 extern int pmtu_expire;
170 
171 /* XXX do these values make any sense? */
172 static int icmp6_mtudisc_hiwat = 1280;
173 static int icmp6_mtudisc_lowat = 256;
174 
175 /*
176  * keep track of # of redirect routes.
177  */
178 static struct rttimer_queue *icmp6_redirect_timeout_q = NULL;
179 
180 /* XXX experimental, turned off */
181 static int icmp6_redirect_hiwat = -1;
182 static int icmp6_redirect_lowat = -1;
183 
184 /* Protect mtudisc and redirect stuffs */
185 static kmutex_t icmp6_mtx __cacheline_aligned;
186 
187 static bool icmp6_reflect_pmtu = false;
188 
189 static void icmp6_errcount(u_int, int, int);
190 static int icmp6_rip6_input(struct mbuf **, int);
191 static void icmp6_reflect(struct mbuf *, size_t);
192 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
193 static const char *icmp6_redirect_diag(char *, size_t, struct in6_addr *,
194     struct in6_addr *, struct in6_addr *);
195 static void icmp6_redirect_input(struct mbuf *, int);
196 static struct mbuf *ni6_input(struct mbuf *, int);
197 static struct mbuf *ni6_nametodns(const char *, int, int);
198 static int ni6_dnsmatch(const char *, int, const char *, int);
199 static int ni6_addrs(struct icmp6_nodeinfo *, struct ifnet **, char *,
200     struct psref *);
201 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
202     struct ifnet *, int);
203 static int icmp6_notify_error(struct mbuf *, int, int, int);
204 static struct rtentry *icmp6_mtudisc_clone(struct sockaddr *);
205 static void icmp6_mtudisc_timeout(struct rtentry *, struct rttimer *);
206 static void icmp6_redirect_timeout(struct rtentry *, struct rttimer *);
207 static void sysctl_net_inet6_icmp6_setup(struct sysctllog **);
208 
209 /* workqueue-based pr_input */
210 static struct wqinput *icmp6_wqinput;
211 static void _icmp6_input(struct mbuf *m, int off, int proto);
212 
213 void
icmp6_init(void)214 icmp6_init(void)
215 {
216 
217           sysctl_net_inet6_icmp6_setup(NULL);
218           mld_init();
219 
220           mutex_init(&icmp6_mtx, MUTEX_DEFAULT, IPL_NONE);
221           mutex_enter(&icmp6_mtx);
222           icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
223           icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout);
224           mutex_exit(&icmp6_mtx);
225 
226           icmp6stat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP6_NSTATS);
227 
228           icmp6_wqinput = wqinput_create("icmp6", _icmp6_input);
229 }
230 
231 static void
icmp6_errcount(u_int base,int type,int code)232 icmp6_errcount(u_int base, int type, int code)
233 {
234           switch (type) {
235           case ICMP6_DST_UNREACH:
236                     switch (code) {
237                     case ICMP6_DST_UNREACH_NOROUTE:
238                               ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOROUTE);
239                               return;
240                     case ICMP6_DST_UNREACH_ADMIN:
241                               ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADMIN);
242                               return;
243                     case ICMP6_DST_UNREACH_BEYONDSCOPE:
244                               ICMP6_STATINC(base +
245                                               ICMP6_ERRSTAT_DST_UNREACH_BEYONDSCOPE);
246                               return;
247                     case ICMP6_DST_UNREACH_ADDR:
248                               ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADDR);
249                               return;
250                     case ICMP6_DST_UNREACH_NOPORT:
251                               ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOPORT);
252                               return;
253                     }
254                     break;
255           case ICMP6_PACKET_TOO_BIG:
256                     ICMP6_STATINC(base + ICMP6_ERRSTAT_PACKET_TOO_BIG);
257                     return;
258           case ICMP6_TIME_EXCEEDED:
259                     switch (code) {
260                     case ICMP6_TIME_EXCEED_TRANSIT:
261                               ICMP6_STATINC(base + ICMP6_ERRSTAT_TIME_EXCEED_TRANSIT);
262                               return;
263                     case ICMP6_TIME_EXCEED_REASSEMBLY:
264                               ICMP6_STATINC(base +
265                                               ICMP6_ERRSTAT_TIME_EXCEED_REASSEMBLY);
266                               return;
267                     }
268                     break;
269           case ICMP6_PARAM_PROB:
270                     switch (code) {
271                     case ICMP6_PARAMPROB_HEADER:
272                               ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_HEADER);
273                               return;
274                     case ICMP6_PARAMPROB_NEXTHEADER:
275                               ICMP6_STATINC(base +
276                                               ICMP6_ERRSTAT_PARAMPROB_NEXTHEADER);
277                               return;
278                     case ICMP6_PARAMPROB_OPTION:
279                               ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_OPTION);
280                               return;
281                     }
282                     break;
283           case ND_REDIRECT:
284                     ICMP6_STATINC(base + ICMP6_ERRSTAT_REDIRECT);
285                     return;
286           }
287           ICMP6_STATINC(base + ICMP6_ERRSTAT_UNKNOWN);
288 }
289 
290 /*
291  * Register a Path MTU Discovery callback.
292  */
293 void
icmp6_mtudisc_callback_register(void (* func)(struct in6_addr *))294 icmp6_mtudisc_callback_register(void (*func)(struct in6_addr *))
295 {
296           struct icmp6_mtudisc_callback *mc, *new;
297 
298           new = kmem_alloc(sizeof(*mc), KM_SLEEP);
299 
300           mutex_enter(&icmp6_mtx);
301           for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
302                mc = LIST_NEXT(mc, mc_list)) {
303                     if (mc->mc_func == func) {
304                               mutex_exit(&icmp6_mtx);
305                               kmem_free(new, sizeof(*mc));
306                               return;
307                     }
308           }
309 
310           new->mc_func = func;
311           LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, new, mc_list);
312           mutex_exit(&icmp6_mtx);
313 }
314 
315 /*
316  * A wrapper function for icmp6_error() necessary when the erroneous packet
317  * may not contain enough scope zone information.
318  */
319 void
icmp6_error2(struct mbuf * m,int type,int code,int param,struct ifnet * ifp,struct in6_addr * src)320 icmp6_error2(struct mbuf *m, int type, int code, int param,
321           struct ifnet *ifp, struct in6_addr *src)
322 {
323           struct ip6_hdr *ip6;
324 
325           KASSERT(ifp != NULL);
326 
327           if (m->m_len < sizeof(struct ip6_hdr)) {
328                     m = m_pullup(m, sizeof(struct ip6_hdr));
329                     if (m == NULL)
330                               return;
331           }
332 
333           ip6 = mtod(m, struct ip6_hdr *);
334 
335           if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
336                     goto out;
337           if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
338                     goto out;
339 
340           *src = ip6->ip6_src;
341           icmp6_error(m, type, code, param);
342           return;
343 
344 out:
345           m_freem(m);
346 }
347 
348 /*
349  * Generate an error packet of type error in response to bad IP6 packet.
350  */
351 void
icmp6_error(struct mbuf * m,int type,int code,int param)352 icmp6_error(struct mbuf *m, int type, int code, int param)
353 {
354           struct ip6_hdr *oip6, *nip6;
355           struct icmp6_hdr *icmp6;
356           u_int preplen;
357           int off;
358           int nxt;
359 
360           ICMP6_STATINC(ICMP6_STAT_ERROR);
361 
362           /* count per-type-code statistics */
363           icmp6_errcount(ICMP6_STAT_OUTERRHIST, type, code);
364 
365           if (m->m_flags & M_DECRYPTED) {
366                     ICMP6_STATINC(ICMP6_STAT_CANTERROR);
367                     goto freeit;
368           }
369 
370           if (M_UNWRITABLE(m, sizeof(struct ip6_hdr)) &&
371               (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL)
372                     return;
373           oip6 = mtod(m, struct ip6_hdr *);
374 
375           /*
376            * If the destination address of the erroneous packet is a multicast
377            * address, or the packet was sent using link-layer multicast,
378            * we should basically suppress sending an error (RFC 2463, Section
379            * 2.4).
380            * We have two exceptions (the item e.2 in that section):
381            * - the Packet Too Big message can be sent for path MTU discovery.
382            * - the Parameter Problem Message that can be allowed an icmp6 error
383            *   in the option type field.  This check has been done in
384            *   ip6_unknown_opt(), so we can just check the type and code.
385            */
386           if ((m->m_flags & (M_BCAST|M_MCAST) ||
387                IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
388               (type != ICMP6_PACKET_TOO_BIG &&
389                (type != ICMP6_PARAM_PROB ||
390                 code != ICMP6_PARAMPROB_OPTION)))
391                     goto freeit;
392 
393           /*
394            * RFC 2463, 2.4 (e.5): source address check.
395            * XXX: the case of anycast source?
396            */
397           if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
398               IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
399                     goto freeit;
400 
401           /*
402            * If we are about to send ICMPv6 against ICMPv6 error/redirect,
403            * don't do it.
404            */
405           nxt = -1;
406           off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
407           if (off >= 0 && nxt == IPPROTO_ICMPV6) {
408                     struct icmp6_hdr *icp;
409 
410                     IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
411                               sizeof(*icp));
412                     if (icp == NULL) {
413                               ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
414                               return;
415                     }
416                     if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
417                         icp->icmp6_type == ND_REDIRECT) {
418                               /*
419                                * ICMPv6 error
420                                * Special case: for redirect (which is
421                                * informational) we must not send icmp6 error.
422                                */
423                               ICMP6_STATINC(ICMP6_STAT_CANTERROR);
424                               goto freeit;
425                     } else {
426                               /* ICMPv6 informational - send the error */
427                     }
428           } else {
429                     /* non-ICMPv6 - send the error */
430           }
431 
432           oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
433 
434           /* Finally, do rate limitation check. */
435           if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
436                     ICMP6_STATINC(ICMP6_STAT_TOOFREQ);
437                     goto freeit;
438           }
439 
440           /*
441            * OK, ICMP6 can be generated.
442            */
443 
444           if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
445                     m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
446 
447           preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
448           M_PREPEND(m, preplen, M_DONTWAIT);
449           if (m && M_UNWRITABLE(m, preplen))
450                     m = m_pullup(m, preplen);
451           if (m == NULL) {
452                     nd6log(LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__);
453                     return;
454           }
455 
456           nip6 = mtod(m, struct ip6_hdr *);
457           nip6->ip6_src  = oip6->ip6_src;
458           nip6->ip6_dst  = oip6->ip6_dst;
459 
460           in6_clearscope(&oip6->ip6_src);
461           in6_clearscope(&oip6->ip6_dst);
462 
463           icmp6 = (struct icmp6_hdr *)(nip6 + 1);
464           icmp6->icmp6_type = type;
465           icmp6->icmp6_code = code;
466           icmp6->icmp6_pptr = htonl((u_int32_t)param);
467 
468           /*
469            * icmp6_reflect() is designed to be in the input path.
470            * icmp6_error() can be called from both input and output path,
471            * and if we are in output path rcvif could contain bogus value.
472            * clear m->m_pkthdr.rcvif for safety, we should have enough scope
473            * information in ip header (nip6).
474            */
475           m_reset_rcvif(m);
476 
477           ICMP6_STATINC(ICMP6_STAT_OUTHIST + type);
478 
479           /* header order: IPv6 - ICMPv6 */
480           icmp6_reflect(m, sizeof(struct ip6_hdr));
481 
482           return;
483 
484 freeit:
485           /*
486            * If we can't tell whether or not we can generate ICMP6, free it.
487            */
488           m_freem(m);
489 }
490 
491 /*
492  * Process a received ICMP6 message.
493  */
494 static void
_icmp6_input(struct mbuf * m,int off,int proto)495 _icmp6_input(struct mbuf *m, int off, int proto)
496 {
497           struct mbuf *n;
498           struct ip6_hdr *ip6, *nip6;
499           struct icmp6_hdr *icmp6, *nicmp6;
500           int icmp6len = m->m_pkthdr.len - off;
501           int code, sum;
502           struct ifnet *rcvif;
503           struct psref psref;
504           char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN];
505 
506           rcvif = m_get_rcvif_psref(m, &psref);
507           if (__predict_false(rcvif == NULL))
508                     goto freeit;
509 
510 #define ICMP6_MAXLEN (sizeof(*nip6) + sizeof(*nicmp6) + 4)
511           KASSERT(ICMP6_MAXLEN < MCLBYTES);
512           icmp6_ifstat_inc(rcvif, ifs6_in_msg);
513 
514           /*
515            * Locate icmp6 structure in mbuf, and check
516            * that not corrupted and of at least minimum length
517            */
518 
519           if (icmp6len < sizeof(struct icmp6_hdr)) {
520                     ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
521                     icmp6_ifstat_inc(rcvif, ifs6_in_error);
522                     goto freeit;
523           }
524 
525           if (m->m_len < sizeof(struct ip6_hdr)) {
526                     m = m_pullup(m, sizeof(struct ip6_hdr));
527                     if (m == NULL) {
528                               ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
529                               icmp6_ifstat_inc(rcvif, ifs6_in_error);
530                               goto freeit;
531                     }
532           }
533 
534           ip6 = mtod(m, struct ip6_hdr *);
535           IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
536           if (icmp6 == NULL) {
537                     ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
538                     icmp6_ifstat_inc(rcvif, ifs6_in_error);
539                     goto freeit;
540           }
541 
542           /*
543            * Enforce alignment requirements that are violated in
544            * some cases, see kern/50766 for details.
545            */
546           if (ACCESSIBLE_POINTER(icmp6, struct ip6_hdr) == 0) {
547                     m = m_copyup(m, off + sizeof(struct icmp6_hdr), 0);
548                     if (m == NULL) {
549                               ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
550                               icmp6_ifstat_inc(rcvif, ifs6_in_error);
551                               goto freeit;
552                     }
553                     ip6 = mtod(m, struct ip6_hdr *);
554                     icmp6 = (struct icmp6_hdr *)(mtod(m, char *) + off);
555           }
556           KASSERT(ACCESSIBLE_POINTER(icmp6, struct ip6_hdr));
557 
558           /*
559            * calculate the checksum
560            */
561           if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
562                     nd6log(LOG_ERR, "ICMP6 checksum error(%d|%x) %s\n",
563                         icmp6->icmp6_type, sum, IN6_PRINT(ip6buf, &ip6->ip6_src));
564                     ICMP6_STATINC(ICMP6_STAT_CHECKSUM);
565                     icmp6_ifstat_inc(rcvif, ifs6_in_error);
566                     goto freeit;
567           }
568 
569 #if defined(NFAITH) && 0 < NFAITH
570           if (faithprefix(&ip6->ip6_dst)) {
571                     /*
572                      * Deliver very specific ICMP6 type only.
573                      * This is important to deliver TOOBIG.  Otherwise PMTUD
574                      * will not work.
575                      */
576                     switch (icmp6->icmp6_type) {
577                     case ICMP6_DST_UNREACH:
578                     case ICMP6_PACKET_TOO_BIG:
579                     case ICMP6_TIME_EXCEEDED:
580                               break;
581                     default:
582                               goto freeit;
583                     }
584           }
585 #endif
586 
587           code = icmp6->icmp6_code;
588           ICMP6_STATINC(ICMP6_STAT_INHIST + icmp6->icmp6_type);
589 
590           switch (icmp6->icmp6_type) {
591           case ICMP6_DST_UNREACH:
592                     icmp6_ifstat_inc(rcvif, ifs6_in_dstunreach);
593                     switch (code) {
594                     case ICMP6_DST_UNREACH_NOROUTE:
595                               code = PRC_UNREACH_NET;
596                               break;
597                     case ICMP6_DST_UNREACH_ADMIN:
598                               icmp6_ifstat_inc(rcvif, ifs6_in_adminprohib);
599                               code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
600                               break;
601                     case ICMP6_DST_UNREACH_ADDR:
602                               code = PRC_HOSTDEAD;
603                               break;
604                     case ICMP6_DST_UNREACH_BEYONDSCOPE:
605                               /* I mean "source address was incorrect." */
606                               code = PRC_UNREACH_NET;
607                               break;
608                     case ICMP6_DST_UNREACH_NOPORT:
609                               code = PRC_UNREACH_PORT;
610                               break;
611                     default:
612                               goto badcode;
613                     }
614                     goto deliver;
615 
616           case ICMP6_PACKET_TOO_BIG:
617                     icmp6_ifstat_inc(rcvif, ifs6_in_pkttoobig);
618 
619                     /*
620                      * MTU is checked in icmp6_mtudisc.
621                      */
622                     code = PRC_MSGSIZE;
623 
624                     /*
625                      * Updating the path MTU will be done after examining
626                      * intermediate extension headers.
627                      */
628                     goto deliver;
629 
630           case ICMP6_TIME_EXCEEDED:
631                     icmp6_ifstat_inc(rcvif, ifs6_in_timeexceed);
632                     switch (code) {
633                     case ICMP6_TIME_EXCEED_TRANSIT:
634                               code = PRC_TIMXCEED_INTRANS;
635                               break;
636                     case ICMP6_TIME_EXCEED_REASSEMBLY:
637                               code = PRC_TIMXCEED_REASS;
638                               break;
639                     default:
640                               goto badcode;
641                     }
642                     goto deliver;
643 
644           case ICMP6_PARAM_PROB:
645                     icmp6_ifstat_inc(rcvif, ifs6_in_paramprob);
646                     switch (code) {
647                     case ICMP6_PARAMPROB_NEXTHEADER:
648                               code = PRC_UNREACH_PROTOCOL;
649                               break;
650                     case ICMP6_PARAMPROB_HEADER:
651                     case ICMP6_PARAMPROB_OPTION:
652                               code = PRC_PARAMPROB;
653                               break;
654                     default:
655                               goto badcode;
656                     }
657                     goto deliver;
658 
659           case ICMP6_ECHO_REQUEST:
660                     icmp6_ifstat_inc(rcvif, ifs6_in_echo);
661                     if (code != 0)
662                               goto badcode;
663                     /*
664                      * Copy mbuf to send to two data paths: userland socket(s),
665                      * and to the querier (echo reply).
666                      * m: a copy for socket, n: a copy for querier
667                      *
668                      * If the first mbuf is shared, or the first mbuf is too short,
669                      * copy the first part of the data into a fresh mbuf.
670                      * Otherwise, we will wrongly overwrite both copies.
671                      */
672                     if ((n = m_copypacket(m, M_DONTWAIT)) == NULL) {
673                               /* Give up local */
674                               n = m;
675                               m = NULL;
676                     } else if (M_UNWRITABLE(n, off + sizeof(struct icmp6_hdr))) {
677                               struct mbuf *n0 = n;
678 
679                               /*
680                                * Prepare an internal mbuf.  m_pullup() doesn't
681                                * always copy the length we specified.
682                                */
683                               if ((n = m_dup(n0, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
684                                         /* Give up local */
685                                         n = m;
686                                         m = NULL;
687                               }
688                               m_freem(n0);
689                     }
690                     IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
691                         sizeof(*nicmp6));
692                     if (nicmp6 == NULL)
693                               goto freeit;
694                     nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
695                     nicmp6->icmp6_code = 0;
696                     if (n) {
697                               net_stat_ref_t icmp6s = ICMP6_STAT_GETREF();
698                               _NET_STATINC_REF(icmp6s, ICMP6_STAT_REFLECT);
699                               _NET_STATINC_REF(icmp6s,
700                                   ICMP6_STAT_OUTHIST + ICMP6_ECHO_REPLY);
701                               ICMP6_STAT_PUTREF();
702                               icmp6_reflect(n, off);
703                     }
704                     if (!m)
705                               goto freeit;
706                     break;
707 
708           case ICMP6_ECHO_REPLY:
709                     icmp6_ifstat_inc(rcvif, ifs6_in_echoreply);
710                     if (code != 0)
711                               goto badcode;
712                     break;
713 
714           case MLD_LISTENER_QUERY:
715           case MLD_LISTENER_REPORT:
716                     if (icmp6len < sizeof(struct mld_hdr))
717                               goto badlen;
718                     if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
719                               icmp6_ifstat_inc(rcvif, ifs6_in_mldquery);
720                     else
721                               icmp6_ifstat_inc(rcvif, ifs6_in_mldreport);
722                     if ((n = m_copypacket(m, M_DONTWAIT)) == NULL) {
723                               /* give up local */
724                               mld_input(m, off);
725                               m = NULL;
726                               goto freeit;
727                     }
728                     mld_input(n, off);
729                     /* m stays. */
730                     break;
731 
732           case MLD_LISTENER_DONE:
733                     icmp6_ifstat_inc(rcvif, ifs6_in_mlddone);
734                     if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
735                               goto badlen;
736                     break;              /* nothing to be done in kernel */
737 
738           case MLD_MTRACE_RESP:
739           case MLD_MTRACE:
740                     /* XXX: these two are experimental.  not officially defined. */
741                     /* XXX: per-interface statistics? */
742                     break;              /* just pass it to applications */
743 
744           case ICMP6_WRUREQUEST:        /* ICMP6_FQDN_QUERY */
745               {
746                     enum { WRU, FQDN } mode;
747 
748                     if (!icmp6_nodeinfo)
749                               break;
750 
751                     if (icmp6len == sizeof(struct icmp6_hdr) + 4)
752                               mode = WRU;
753                     else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
754                               mode = FQDN;
755                     else
756                               goto badlen;
757 
758                     if (mode == FQDN) {
759                               n = m_copypacket(m, M_DONTWAIT);
760                               if (n)
761                                         n = ni6_input(n, off);
762                     } else {
763                               u_char *p;
764                               int maxhlen;
765 
766                               if ((icmp6_nodeinfo & 5) != 5)
767                                         break;
768 
769                               if (code != 0)
770                                         goto badcode;
771                               MGETHDR(n, M_DONTWAIT, m->m_type);
772                               if (n && ICMP6_MAXLEN > MHLEN) {
773                                         MCLGET(n, M_DONTWAIT);
774                                         if ((n->m_flags & M_EXT) == 0) {
775                                                   m_free(n);
776                                                   n = NULL;
777                                         }
778                               }
779                               if (n == NULL) {
780                                         /* Give up remote */
781                                         break;
782                               }
783                               m_reset_rcvif(n);
784                               n->m_len = 0;
785                               maxhlen = M_TRAILINGSPACE(n) - ICMP6_MAXLEN;
786                               if (maxhlen < 0) {
787                                         m_free(n);
788                                         break;
789                               }
790                               if (maxhlen > hostnamelen)
791                                         maxhlen = hostnamelen;
792                               /*
793                                * Copy IPv6 and ICMPv6 only.
794                                */
795                               nip6 = mtod(n, struct ip6_hdr *);
796                               memcpy(nip6, ip6, sizeof(struct ip6_hdr));
797                               nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
798                               memcpy(nicmp6, icmp6, sizeof(struct icmp6_hdr));
799 
800                               p = (u_char *)(nicmp6 + 1);
801                               memset(p, 0, 4);
802                               memcpy(p + 4, hostname, maxhlen); /* meaningless TTL */
803 
804                               m_copy_pkthdr(n, m);
805                               n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
806                                         sizeof(struct icmp6_hdr) + 4 + maxhlen;
807                               nicmp6->icmp6_type = ICMP6_WRUREPLY;
808                               nicmp6->icmp6_code = 0;
809                     }
810                     if (n) {
811                               net_stat_ref_t icmp6s = ICMP6_STAT_GETREF();
812                               _NET_STATINC_REF(icmp6s, ICMP6_STAT_REFLECT);
813                               _NET_STATINC_REF(icmp6s,
814                                   ICMP6_STAT_OUTHIST + ICMP6_WRUREPLY);
815                               ICMP6_STAT_PUTREF();
816                               icmp6_reflect(n, sizeof(struct ip6_hdr));
817                     }
818                     break;
819               }
820 
821           case ICMP6_WRUREPLY:
822                     if (code != 0)
823                               goto badcode;
824                     break;
825 
826           case ND_ROUTER_SOLICIT:
827                     icmp6_ifstat_inc(rcvif, ifs6_in_routersolicit);
828                     /* FALLTHROUGH */
829           case ND_ROUTER_ADVERT:
830                     if (icmp6->icmp6_type == ND_ROUTER_ADVERT)
831                               icmp6_ifstat_inc(rcvif, ifs6_in_routeradvert);
832                     if (code != 0)
833                               goto badcode;
834                     if ((icmp6->icmp6_type == ND_ROUTER_SOLICIT &&
835                         icmp6len < sizeof(struct nd_router_solicit)) ||
836                         (icmp6->icmp6_type == ND_ROUTER_ADVERT &&
837                         icmp6len < sizeof(struct nd_router_advert)))
838                               goto badlen;
839                     if ((n = m_copypacket(m, M_DONTWAIT)) == NULL) {
840                               /* give up local */
841                               nd6_rtr_cache(m, off, icmp6len, icmp6->icmp6_type);
842                               m = NULL;
843                               goto freeit;
844                     }
845                     nd6_rtr_cache(n, off, icmp6len, icmp6->icmp6_type);
846                     /* m stays. */
847                     break;
848 
849           case ND_NEIGHBOR_SOLICIT:
850                     icmp6_ifstat_inc(rcvif, ifs6_in_neighborsolicit);
851                     if (code != 0)
852                               goto badcode;
853                     if (icmp6len < sizeof(struct nd_neighbor_solicit))
854                               goto badlen;
855                     if ((n = m_copypacket(m, M_DONTWAIT)) == NULL) {
856                               /* give up local */
857                               nd6_ns_input(m, off, icmp6len);
858                               m = NULL;
859                               goto freeit;
860                     }
861                     nd6_ns_input(n, off, icmp6len);
862                     /* m stays. */
863                     break;
864 
865           case ND_NEIGHBOR_ADVERT:
866                     icmp6_ifstat_inc(rcvif, ifs6_in_neighboradvert);
867                     if (code != 0)
868                               goto badcode;
869                     if (icmp6len < sizeof(struct nd_neighbor_advert))
870                               goto badlen;
871                     if ((n = m_copypacket(m, M_DONTWAIT)) == NULL) {
872                               /* give up local */
873                               nd6_na_input(m, off, icmp6len);
874                               m = NULL;
875                               goto freeit;
876                     }
877                     nd6_na_input(n, off, icmp6len);
878                     /* m stays. */
879                     break;
880 
881           case ND_REDIRECT:
882                     icmp6_ifstat_inc(rcvif, ifs6_in_redirect);
883                     if (code != 0)
884                               goto badcode;
885                     if (icmp6len < sizeof(struct nd_redirect))
886                               goto badlen;
887                     if ((n = m_copypacket(m, M_DONTWAIT)) == NULL) {
888                               /* give up local */
889                               icmp6_redirect_input(m, off);
890                               m = NULL;
891                               goto freeit;
892                     }
893                     icmp6_redirect_input(n, off);
894                     /* m stays. */
895                     break;
896 
897           case ICMP6_ROUTER_RENUMBERING:
898                     if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
899                         code != ICMP6_ROUTER_RENUMBERING_RESULT)
900                               goto badcode;
901                     if (icmp6len < sizeof(struct icmp6_router_renum))
902                               goto badlen;
903                     break;
904 
905           default:
906                     nd6log(LOG_DEBUG,
907                         "unknown type %d(src=%s, dst=%s, ifid=%d)\n",
908                         icmp6->icmp6_type,
909                         IN6_PRINT(ip6buf, &ip6->ip6_src),
910                         IN6_PRINT(ip6buf2, &ip6->ip6_dst),
911                         rcvif ? rcvif->if_index : 0);
912                     if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
913                               /* ICMPv6 error: MUST deliver it by spec... */
914                               code = PRC_NCMDS;
915                               /* deliver */
916                     } else {
917                               /* ICMPv6 informational: MUST not deliver */
918                               break;
919                     }
920           deliver:
921                     if (icmp6_notify_error(m, off, icmp6len, code)) {
922                               /* In this case, m should've been freed. */
923                               m_put_rcvif_psref(rcvif, &psref);
924                               return;
925                     }
926                     break;
927 
928           badcode:
929                     ICMP6_STATINC(ICMP6_STAT_BADCODE);
930                     break;
931 
932           badlen:
933                     ICMP6_STATINC(ICMP6_STAT_BADLEN);
934                     break;
935           }
936           m_put_rcvif_psref(rcvif, &psref);
937 
938           /* deliver the packet to appropriate sockets */
939           icmp6_rip6_input(&m, off);
940 
941           return;
942 
943 freeit:
944           m_put_rcvif_psref(rcvif, &psref);
945           m_freem(m);
946           return;
947 }
948 
949 int
icmp6_input(struct mbuf ** mp,int * offp,int proto)950 icmp6_input(struct mbuf **mp, int *offp, int proto)
951 {
952 
953           wqinput_input(icmp6_wqinput, *mp, *offp, proto);
954 
955           return IPPROTO_DONE;
956 }
957 
958 static int
icmp6_notify_error(struct mbuf * m,int off,int icmp6len,int code)959 icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code)
960 {
961           struct icmp6_hdr *icmp6;
962           struct ip6_hdr *eip6;
963           u_int32_t notifymtu;
964           struct sockaddr_in6 icmp6src, icmp6dst;
965 
966           if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
967                     ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
968                     goto freeit;
969           }
970           IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
971               sizeof(*icmp6) + sizeof(struct ip6_hdr));
972           if (icmp6 == NULL) {
973                     ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
974                     return (-1);
975           }
976           eip6 = (struct ip6_hdr *)(icmp6 + 1);
977 
978           /* Detect the upper level protocol */
979           {
980                     void *(*ctlfunc)(int, const struct sockaddr *, void *);
981                     u_int8_t nxt = eip6->ip6_nxt;
982                     int eoff = off + sizeof(struct icmp6_hdr) +
983                               sizeof(struct ip6_hdr);
984                     struct ip6ctlparam ip6cp;
985                     struct in6_addr *finaldst = NULL;
986                     int icmp6type = icmp6->icmp6_type;
987                     struct ip6_frag *fh;
988                     struct ip6_rthdr *rth;
989                     struct ifnet *rcvif;
990                     int s;
991 
992                     while (1) { /* XXX: should avoid infinite loop explicitly? */
993                               struct ip6_ext *eh;
994 
995                               switch (nxt) {
996                               case IPPROTO_HOPOPTS:
997                               case IPPROTO_DSTOPTS:
998                               case IPPROTO_AH:
999                                         IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
1000                                             eoff, sizeof(*eh));
1001                                         if (eh == NULL) {
1002                                                   ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
1003                                                   return (-1);
1004                                         }
1005 
1006                                         if (nxt == IPPROTO_AH)
1007                                                   eoff += (eh->ip6e_len + 2) << 2;
1008                                         else
1009                                                   eoff += (eh->ip6e_len + 1) << 3;
1010                                         nxt = eh->ip6e_nxt;
1011                                         break;
1012                               case IPPROTO_ROUTING:
1013                                         /* Ignore the option. */
1014                                         IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1015                                             eoff, sizeof(*rth));
1016                                         if (rth == NULL) {
1017                                                   ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
1018                                                   return (-1);
1019                                         }
1020 
1021                                         eoff += (rth->ip6r_len + 1) << 3;
1022                                         nxt = rth->ip6r_nxt;
1023                                         break;
1024                               case IPPROTO_FRAGMENT:
1025                                         IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1026                                             eoff, sizeof(*fh));
1027                                         if (fh == NULL) {
1028                                                   ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
1029                                                   return (-1);
1030                                         }
1031                                         /*
1032                                          * Data after a fragment header is meaningless
1033                                          * unless it is the first fragment, but
1034                                          * we'll go to the notify label for path MTU
1035                                          * discovery.
1036                                          */
1037                                         if (fh->ip6f_offlg & IP6F_OFF_MASK)
1038                                                   goto notify;
1039 
1040                                         eoff += sizeof(struct ip6_frag);
1041                                         nxt = fh->ip6f_nxt;
1042                                         break;
1043                               default:
1044                                         /*
1045                                          * This case includes ESP and the No Next
1046                                          * Header.  In such cases going to the notify
1047                                          * label does not have any meaning
1048                                          * (i.e. ctlfunc will be NULL), but we go
1049                                          * anyway since we might have to update
1050                                          * path MTU information.
1051                                          */
1052                                         goto notify;
1053                               }
1054                     }
1055             notify:
1056                     IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1057                         sizeof(*icmp6) + sizeof(struct ip6_hdr));
1058                     if (icmp6 == NULL) {
1059                               ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
1060                               return (-1);
1061                     }
1062 
1063                     /*
1064                      * retrieve parameters from the inner IPv6 header, and convert
1065                      * them into sockaddr structures.
1066                      * XXX: there is no guarantee that the source or destination
1067                      * addresses of the inner packet are in the same scope zone as
1068                      * the addresses of the icmp packet.  But there is no other
1069                      * way to determine the zone.
1070                      */
1071                     eip6 = (struct ip6_hdr *)(icmp6 + 1);
1072 
1073                     rcvif = m_get_rcvif(m, &s);
1074                     if (__predict_false(rcvif == NULL))
1075                               goto freeit;
1076                     sockaddr_in6_init(&icmp6dst,
1077                         (finaldst == NULL) ? &eip6->ip6_dst : finaldst, 0, 0, 0);
1078                     if (in6_setscope(&icmp6dst.sin6_addr, rcvif, NULL)) {
1079                               m_put_rcvif(rcvif, &s);
1080                               goto freeit;
1081                     }
1082                     sockaddr_in6_init(&icmp6src, &eip6->ip6_src, 0, 0, 0);
1083                     if (in6_setscope(&icmp6src.sin6_addr, rcvif, NULL)) {
1084                               m_put_rcvif(rcvif, &s);
1085                               goto freeit;
1086                     }
1087                     m_put_rcvif(rcvif, &s);
1088 
1089                     icmp6src.sin6_flowinfo =
1090                               (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1091 
1092                     if (finaldst == NULL)
1093                               finaldst = &eip6->ip6_dst;
1094                     ip6cp.ip6c_m = m;
1095                     ip6cp.ip6c_icmp6 = icmp6;
1096                     ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1097                     ip6cp.ip6c_off = eoff;
1098                     ip6cp.ip6c_finaldst = finaldst;
1099                     ip6cp.ip6c_src = &icmp6src;
1100                     ip6cp.ip6c_nxt = nxt;
1101 
1102                     if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1103                               notifymtu = ntohl(icmp6->icmp6_mtu);
1104                               ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1105                     }
1106 
1107                     ctlfunc = inet6sw[ip6_protox[nxt]].pr_ctlinput;
1108                     if (ctlfunc) {
1109                               (void)(*ctlfunc)(code, sin6tosa(&icmp6dst), &ip6cp);
1110                     }
1111           }
1112           return (0);
1113 
1114 freeit:
1115           m_freem(m);
1116           return (-1);
1117 }
1118 
1119 void
icmp6_mtudisc_update(struct ip6ctlparam * ip6cp,int validated)1120 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1121 {
1122           unsigned long rtcount;
1123           struct icmp6_mtudisc_callback *mc;
1124           struct in6_addr *dst = ip6cp->ip6c_finaldst;
1125           struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1126           struct mbuf *m = ip6cp->ip6c_m;         /* will be necessary for scope issue */
1127           u_int mtu = ntohl(icmp6->icmp6_mtu);
1128           struct rtentry *rt = NULL;
1129           struct sockaddr_in6 sin6;
1130           struct ifnet *rcvif;
1131           int s;
1132 
1133           /*
1134            * The MTU should not be less than the minimal IPv6 MTU except for the
1135            * hack in ip6_output/ip6_setpmtu where we always include a frag header.
1136            * In that one case, the MTU might be less than 1280.
1137            */
1138           if (__predict_false(mtu < IPV6_MMTU - sizeof(struct ip6_frag))) {
1139                     /* is the mtu even sane? */
1140                     if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1141                               return;
1142                     if (!validated)
1143                               return;
1144                     mtu = IPV6_MMTU - sizeof(struct ip6_frag);
1145           }
1146 
1147           /*
1148            * allow non-validated cases if memory is plenty, to make traffic
1149            * from non-connected pcb happy.
1150            */
1151           mutex_enter(&icmp6_mtx);
1152           rtcount = rt_timer_count(icmp6_mtudisc_timeout_q);
1153           if (validated) {
1154                     if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat) {
1155                               mutex_exit(&icmp6_mtx);
1156                               return;
1157                     } else if (0 <= icmp6_mtudisc_lowat &&
1158                         rtcount > icmp6_mtudisc_lowat) {
1159                               /*
1160                                * XXX nuke a victim, install the new one.
1161                                */
1162                     }
1163           } else {
1164                     if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat) {
1165                               mutex_exit(&icmp6_mtx);
1166                               return;
1167                     }
1168           }
1169           mutex_exit(&icmp6_mtx);
1170 
1171           memset(&sin6, 0, sizeof(sin6));
1172           sin6.sin6_family = PF_INET6;
1173           sin6.sin6_len = sizeof(struct sockaddr_in6);
1174           sin6.sin6_addr = *dst;
1175           rcvif = m_get_rcvif(m, &s);
1176           if (__predict_false(rcvif == NULL))
1177                     return;
1178           if (in6_setscope(&sin6.sin6_addr, rcvif, NULL)) {
1179                     m_put_rcvif(rcvif, &s);
1180                     return;
1181           }
1182           m_put_rcvif(rcvif, &s);
1183 
1184           rt = icmp6_mtudisc_clone(sin6tosa(&sin6));
1185 
1186           if (rt && (rt->rt_flags & RTF_HOST) &&
1187               !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
1188               (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) {
1189                     if (mtu < rt->rt_ifp->if_mtu) {
1190                               ICMP6_STATINC(ICMP6_STAT_PMTUCHG);
1191                               rt->rt_rmx.rmx_mtu = mtu;
1192                     }
1193           }
1194           if (rt) {
1195                     rt_unref(rt);
1196           }
1197 
1198           /*
1199            * Notify protocols that the MTU for this destination
1200            * has changed.
1201            */
1202           mutex_enter(&icmp6_mtx);
1203           for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
1204                mc = LIST_NEXT(mc, mc_list))
1205                     (*mc->mc_func)(&sin6.sin6_addr);
1206           mutex_exit(&icmp6_mtx);
1207 }
1208 
1209 /*
1210  * Process a Node Information Query packet, based on
1211  * draft-ietf-ipngwg-icmp-name-lookups-07.
1212  *
1213  * Spec incompatibilities:
1214  * - IPv6 Subject address handling
1215  * - IPv4 Subject address handling support missing
1216  * - Proxy reply (answer even if it's not for me)
1217  * - joins NI group address at in6_ifattach() time only, does not cope
1218  *   with hostname changes by sethostname(3)
1219  */
1220 static struct mbuf *
ni6_input(struct mbuf * m,int off)1221 ni6_input(struct mbuf *m, int off)
1222 {
1223           struct icmp6_nodeinfo *ni6, *nni6;
1224           struct mbuf *n = NULL;
1225           u_int16_t qtype;
1226           int subjlen;
1227           int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1228           struct ni_reply_fqdn *fqdn;
1229           int addrs;                    /* for NI_QTYPE_NODEADDR */
1230           struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1231           struct sockaddr_in6 sin6; /* ip6_dst */
1232           struct in6_addr in6_subj; /* subject address */
1233           struct ip6_hdr *ip6;
1234           int oldfqdn = 0;    /* if 1, return pascal string (03 draft) */
1235           char *subj = NULL;
1236           struct ifnet *rcvif;
1237           int s, ss;
1238           struct ifaddr *ifa;
1239           struct psref psref;
1240 
1241           ip6 = mtod(m, struct ip6_hdr *);
1242           IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1243           if (ni6 == NULL) {
1244                     /* m is already reclaimed */
1245                     return NULL;
1246           }
1247           KASSERT((m->m_flags & M_PKTHDR) != 0);
1248 
1249           /*
1250            * Validate IPv6 destination address.
1251            *
1252            * The Responder must discard the Query without further processing
1253            * unless it is one of the Responder's unicast or anycast addresses, or
1254            * a link-local scope multicast address which the Responder has joined.
1255            * [icmp-name-lookups-07, Section 4.]
1256            */
1257           sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0);
1258           /* XXX scopeid */
1259           ss = pserialize_read_enter();
1260           ifa = ifa_ifwithaddr(sin6tosa(&sin6));
1261           if (ifa != NULL) {
1262                     ; /* unicast/anycast, fine */
1263           } else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr)) {
1264                     ; /* link-local multicast, fine */
1265           } else {
1266                     pserialize_read_exit(ss);
1267                     goto bad;
1268           }
1269           pserialize_read_exit(ss);
1270 
1271           /* validate query Subject field. */
1272           qtype = ntohs(ni6->ni_qtype);
1273           subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1274           switch (qtype) {
1275           case NI_QTYPE_NOOP:
1276           case NI_QTYPE_SUPTYPES:
1277                     /* 07 draft */
1278                     if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1279                               break;
1280                     /* FALLTHROUGH */
1281           case NI_QTYPE_FQDN:
1282           case NI_QTYPE_NODEADDR:
1283           case NI_QTYPE_IPV4ADDR:
1284                     switch (ni6->ni_code) {
1285                     case ICMP6_NI_SUBJ_IPV6:
1286 #if ICMP6_NI_SUBJ_IPV6 != 0
1287                     case 0:
1288 #endif
1289                               /*
1290                                * backward compatibility - try to accept 03 draft
1291                                * format, where no Subject is present.
1292                                */
1293                               if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1294                                   subjlen == 0) {
1295                                         oldfqdn++;
1296                                         break;
1297                               }
1298 #if ICMP6_NI_SUBJ_IPV6 != 0
1299                               if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1300                                         goto bad;
1301 #endif
1302 
1303                               if (subjlen != sizeof(sin6.sin6_addr))
1304                                         goto bad;
1305 
1306                               /*
1307                                * Validate Subject address.
1308                                *
1309                                * Not sure what exactly "address belongs to the node"
1310                                * means in the spec, is it just unicast, or what?
1311                                *
1312                                * At this moment we consider Subject address as
1313                                * "belong to the node" if the Subject address equals
1314                                * to the IPv6 destination address; validation for
1315                                * IPv6 destination address should have done enough
1316                                * check for us.
1317                                *
1318                                * We do not do proxy at this moment.
1319                                */
1320                               /* m_pulldown instead of copy? */
1321                               m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1322                                   subjlen, (void *)&in6_subj);
1323                               rcvif = m_get_rcvif(m, &s);
1324                               if (__predict_false(rcvif == NULL))
1325                                         goto bad;
1326                               if (in6_setscope(&in6_subj, rcvif, NULL)) {
1327                                         m_put_rcvif(rcvif, &s);
1328                                         goto bad;
1329                               }
1330                               m_put_rcvif(rcvif, &s);
1331 
1332                               subj = (char *)&in6_subj;
1333                               if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1334                                         break;
1335 
1336                               /*
1337                                * XXX if we are to allow other cases, we should really
1338                                * be careful about scope here.
1339                                * basically, we should disallow queries toward IPv6
1340                                * destination X with subject Y, if scope(X) > scope(Y).
1341                                * if we allow scope(X) > scope(Y), it will result in
1342                                * information leakage across scope boundary.
1343                                */
1344                               goto bad;
1345 
1346                     case ICMP6_NI_SUBJ_FQDN:
1347                               /*
1348                                * Validate Subject name with gethostname(3).
1349                                *
1350                                * The behavior may need some debate, since:
1351                                * - we are not sure if the node has FQDN as
1352                                *   hostname (returned by gethostname(3)).
1353                                * - the code does wildcard match for truncated names.
1354                                *   however, we are not sure if we want to perform
1355                                *   wildcard match, if gethostname(3) side has
1356                                *   truncated hostname.
1357                                */
1358                               n = ni6_nametodns(hostname, hostnamelen, 0);
1359                               if (!n || n->m_next || n->m_len == 0)
1360                                         goto bad;
1361                               IP6_EXTHDR_GET(subj, char *, m,
1362                                   off + sizeof(struct icmp6_nodeinfo), subjlen);
1363                               if (subj == NULL)
1364                                         goto bad;
1365                               if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1366                                   n->m_len)) {
1367                                         goto bad;
1368                               }
1369                               m_freem(n);
1370                               n = NULL;
1371                               break;
1372 
1373                     case ICMP6_NI_SUBJ_IPV4:      /* XXX: to be implemented? */
1374                     default:
1375                               goto bad;
1376                     }
1377                     break;
1378           }
1379 
1380           /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1381           switch (qtype) {
1382           case NI_QTYPE_FQDN:
1383                     if ((icmp6_nodeinfo & 1) == 0)
1384                               goto bad;
1385                     break;
1386           case NI_QTYPE_NODEADDR:
1387           case NI_QTYPE_IPV4ADDR:
1388                     if ((icmp6_nodeinfo & 2) == 0)
1389                               goto bad;
1390                     break;
1391           }
1392 
1393           /* guess reply length */
1394           switch (qtype) {
1395           case NI_QTYPE_NOOP:
1396                     break;              /* no reply data */
1397           case NI_QTYPE_SUPTYPES:
1398                     replylen += sizeof(u_int32_t);
1399                     break;
1400           case NI_QTYPE_FQDN:
1401                     /* will append an mbuf */
1402                     replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1403                     break;
1404           case NI_QTYPE_NODEADDR:
1405                     addrs = ni6_addrs(ni6, &ifp, subj, &psref);
1406                     replylen += addrs *
1407                         (sizeof(struct in6_addr) + sizeof(u_int32_t));
1408                     if (replylen > MCLBYTES)
1409                               replylen = MCLBYTES; /* XXX: will truncate pkt later */
1410                     break;
1411           case NI_QTYPE_IPV4ADDR:
1412                     /* unsupported - should respond with unknown Qtype? */
1413                     goto bad;
1414           default:
1415                     /*
1416                      * XXX: We must return a reply with the ICMP6 code
1417                      * `unknown Qtype' in this case.  However we regard the case
1418                      * as an FQDN query for backward compatibility.
1419                      * Older versions set a random value to this field,
1420                      * so it rarely varies in the defined qtypes.
1421                      * But the mechanism is not reliable...
1422                      * maybe we should obsolete older versions.
1423                      */
1424                     qtype = NI_QTYPE_FQDN;
1425                     /* will append an mbuf */
1426                     replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1427                     oldfqdn++;
1428                     break;
1429           }
1430 
1431           /* allocate an mbuf to reply. */
1432           MGETHDR(n, M_DONTWAIT, m->m_type);
1433           if (n == NULL) {
1434                     goto bad;
1435           }
1436           m_move_pkthdr(n, m);
1437           if (replylen > MHLEN) {
1438                     if (replylen > MCLBYTES) {
1439                               /*
1440                                * XXX: should we try to allocate more? But MCLBYTES
1441                                * is probably much larger than IPV6_MMTU...
1442                                */
1443                               goto bad;
1444                     }
1445                     MCLGET(n, M_DONTWAIT);
1446                     if ((n->m_flags & M_EXT) == 0) {
1447                               goto bad;
1448                     }
1449           }
1450           n->m_pkthdr.len = n->m_len = replylen;
1451 
1452           /* copy mbuf header and IPv6 + Node Information base headers */
1453           bcopy(mtod(m, void *), mtod(n, void *), sizeof(struct ip6_hdr));
1454           nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1455           bcopy((void *)ni6, (void *)nni6, sizeof(struct icmp6_nodeinfo));
1456 
1457           /* qtype dependent procedure */
1458           switch (qtype) {
1459           case NI_QTYPE_NOOP:
1460                     nni6->ni_code = ICMP6_NI_SUCCESS;
1461                     nni6->ni_flags = 0;
1462                     break;
1463           case NI_QTYPE_SUPTYPES:
1464           {
1465                     u_int32_t v;
1466                     nni6->ni_code = ICMP6_NI_SUCCESS;
1467                     nni6->ni_flags = htons(0x0000);         /* raw bitmap */
1468                     /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1469                     v = (u_int32_t)htonl(0x0000000f);
1470                     memcpy(nni6 + 1, &v, sizeof(u_int32_t));
1471                     break;
1472           }
1473           case NI_QTYPE_FQDN:
1474                     nni6->ni_code = ICMP6_NI_SUCCESS;
1475                     fqdn = (struct ni_reply_fqdn *)(mtod(n, char *) +
1476                         sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1477                     nni6->ni_flags = 0; /* XXX: meaningless TTL */
1478                     fqdn->ni_fqdn_ttl = 0;        /* ditto. */
1479                     /*
1480                      * XXX do we really have FQDN in variable "hostname"?
1481                      */
1482                     n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1483                     if (n->m_next == NULL)
1484                               goto bad;
1485                     /* XXX we assume that n->m_next is not a chain */
1486                     if (n->m_next->m_next != NULL)
1487                               goto bad;
1488                     n->m_pkthdr.len += n->m_next->m_len;
1489                     break;
1490           case NI_QTYPE_NODEADDR:
1491           {
1492                     int lenlim, copied;
1493 
1494                     nni6->ni_code = ICMP6_NI_SUCCESS;
1495                     n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1496                         sizeof(struct icmp6_nodeinfo);
1497                     lenlim = M_TRAILINGSPACE(n);
1498                     copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1499                     if_put(ifp, &psref);
1500                     ifp = NULL;
1501                     /* update mbuf length */
1502                     n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1503                         sizeof(struct icmp6_nodeinfo) + copied;
1504                     break;
1505           }
1506           default:
1507                     panic("%s: impossible", __func__);
1508                     break;
1509           }
1510 
1511           nni6->ni_type = ICMP6_NI_REPLY;
1512           m_freem(m);
1513           return n;
1514 
1515 bad:
1516           if_put(ifp, &psref);
1517           m_freem(m);
1518           m_freem(n);
1519           return NULL;
1520 }
1521 
1522 #define isupper(x) ('A' <= (x) && (x) <= 'Z')
1523 #define isalpha(x) (('A' <= (x) && (x) <= 'Z') || ('a' <= (x) && (x) <= 'z'))
1524 #define isalnum(x) (isalpha(x) || ('0' <= (x) && (x) <= '9'))
1525 #define tolower(x) (isupper(x) ? (x) + 'a' - 'A' : (x))
1526 
1527 /*
1528  * make a mbuf with DNS-encoded string.  no compression support.
1529  *
1530  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1531  * treated as truncated name (two \0 at the end).  this is a wild guess.
1532  *
1533  * old - return pascal string if non-zero
1534  */
1535 static struct mbuf *
ni6_nametodns(const char * name,int namelen,int old)1536 ni6_nametodns(const char *name, int namelen, int old)
1537 {
1538           struct mbuf *m;
1539           char *cp, *ep;
1540           const char *p, *q;
1541           int i, len, nterm;
1542 
1543           if (old)
1544                     len = namelen + 1;
1545           else
1546                     len = MCLBYTES;
1547 
1548           /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1549           MGET(m, M_DONTWAIT, MT_DATA);
1550           if (m && len > MLEN) {
1551                     MCLGET(m, M_DONTWAIT);
1552                     if ((m->m_flags & M_EXT) == 0)
1553                               goto fail;
1554           }
1555           if (!m)
1556                     goto fail;
1557           m->m_next = NULL;
1558 
1559           if (old) {
1560                     m->m_len = len;
1561                     *mtod(m, char *) = namelen;
1562                     memcpy(mtod(m, char *) + 1, name, namelen);
1563                     return m;
1564           } else {
1565                     m->m_len = 0;
1566                     cp = mtod(m, char *);
1567                     ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1568 
1569                     /* if not certain about my name, return empty buffer */
1570                     if (namelen == 0)
1571                               return m;
1572 
1573                     /*
1574                      * guess if it looks like shortened hostname, or FQDN.
1575                      * shortened hostname needs two trailing "\0".
1576                      */
1577                     i = 0;
1578                     for (p = name; p < name + namelen; p++) {
1579                               if (*p == '.')
1580                                         i++;
1581                     }
1582                     if (i < 2)
1583                               nterm = 2;
1584                     else
1585                               nterm = 1;
1586 
1587                     p = name;
1588                     while (cp < ep && p < name + namelen) {
1589                               i = 0;
1590                               for (q = p; q < name + namelen && *q && *q != '.'; q++)
1591                                         i++;
1592                               /* result does not fit into mbuf */
1593                               if (cp + i + 1 >= ep)
1594                                         goto fail;
1595                               /*
1596                                * DNS label length restriction, RFC1035 page 8.
1597                                * "i == 0" case is included here to avoid returning
1598                                * 0-length label on "foo..bar".
1599                                */
1600                               if (i <= 0 || i >= 64)
1601                                         goto fail;
1602                               *cp++ = i;
1603                               if (!isalpha(p[0]) || !isalnum(p[i - 1]))
1604                                         goto fail;
1605                               while (i > 0) {
1606                                         if (!isalnum(*p) && *p != '-')
1607                                                   goto fail;
1608                                         if (isupper(*p)) {
1609                                                   *cp++ = tolower(*p);
1610                                                   p++;
1611                                         } else
1612                                                   *cp++ = *p++;
1613                                         i--;
1614                               }
1615                               p = q;
1616                               if (p < name + namelen && *p == '.')
1617                                         p++;
1618                     }
1619                     /* termination */
1620                     if (cp + nterm >= ep)
1621                               goto fail;
1622                     while (nterm-- > 0)
1623                               *cp++ = '\0';
1624                     m->m_len = cp - mtod(m, char *);
1625                     return m;
1626           }
1627 
1628           panic("should not reach here");
1629           /* NOTREACHED */
1630 
1631 fail:
1632           m_freem(m);
1633           return NULL;
1634 }
1635 
1636 /*
1637  * check if two DNS-encoded string matches.  takes care of truncated
1638  * form (with \0\0 at the end).  no compression support.
1639  * XXX upper/lowercase match (see RFC2065)
1640  */
1641 static int
ni6_dnsmatch(const char * a,int alen,const char * b,int blen)1642 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1643 {
1644           const char *a0, *b0;
1645           int l;
1646 
1647           /* simplest case - need validation? */
1648           if (alen == blen && memcmp(a, b, alen) == 0)
1649                     return 1;
1650 
1651           a0 = a;
1652           b0 = b;
1653 
1654           /* termination is mandatory */
1655           if (alen < 2 || blen < 2)
1656                     return 0;
1657           if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1658                     return 0;
1659           alen--;
1660           blen--;
1661 
1662           while (a - a0 < alen && b - b0 < blen) {
1663                     if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1664                               return 0;
1665 
1666                     if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1667                               return 0;
1668                     /* we don't support compression yet */
1669                     if (a[0] >= 64 || b[0] >= 64)
1670                               return 0;
1671 
1672                     /* truncated case */
1673                     if (a[0] == 0 && a - a0 == alen - 1)
1674                               return 1;
1675                     if (b[0] == 0 && b - b0 == blen - 1)
1676                               return 1;
1677                     if (a[0] == 0 || b[0] == 0)
1678                               return 0;
1679 
1680                     if (a[0] != b[0])
1681                               return 0;
1682                     l = a[0];
1683                     if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1684                               return 0;
1685                     if (memcmp(a + 1, b + 1, l) != 0)
1686                               return 0;
1687 
1688                     a += 1 + l;
1689                     b += 1 + l;
1690           }
1691 
1692           if (a - a0 == alen && b - b0 == blen)
1693                     return 1;
1694           else
1695                     return 0;
1696 }
1697 
1698 /*
1699  * calculate the number of addresses to be returned in the node info reply.
1700  */
1701 static int
ni6_addrs(struct icmp6_nodeinfo * ni6,struct ifnet ** ifpp,char * subj,struct psref * psref)1702 ni6_addrs(struct icmp6_nodeinfo *ni6, struct ifnet **ifpp, char *subj,
1703     struct psref *psref)
1704 {
1705           struct ifnet *ifp;
1706           struct in6_ifaddr *ia6;
1707           struct ifaddr *ifa;
1708           struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1709           int addrs = 0, addrsofif, iffound = 0;
1710           int niflags = ni6->ni_flags;
1711           int s;
1712 
1713           if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1714                     switch (ni6->ni_code) {
1715                     case ICMP6_NI_SUBJ_IPV6:
1716                               if (subj == NULL) /* must be impossible... */
1717                                         return 0;
1718                               subj_ip6 = (struct sockaddr_in6 *)subj;
1719                               break;
1720                     default:
1721                               /*
1722                                * XXX: we only support IPv6 subject address for
1723                                * this Qtype.
1724                                */
1725                               return 0;
1726                     }
1727           }
1728 
1729           s = pserialize_read_enter();
1730           IFNET_READER_FOREACH(ifp) {
1731                     addrsofif = 0;
1732                     IFADDR_READER_FOREACH(ifa, ifp) {
1733                               if (ifa->ifa_addr->sa_family != AF_INET6)
1734                                         continue;
1735                               ia6 = (struct in6_ifaddr *)ifa;
1736 
1737                               if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1738                                   IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1739                                    &ia6->ia_addr.sin6_addr))
1740                                         iffound = 1;
1741 
1742                               /*
1743                                * IPv4-mapped addresses can only be returned by a
1744                                * Node Information proxy, since they represent
1745                                * addresses of IPv4-only nodes, which perforce do
1746                                * not implement this protocol.
1747                                * [icmp-name-lookups-07, Section 5.4]
1748                                * So we don't support NI_NODEADDR_FLAG_COMPAT in
1749                                * this function at this moment.
1750                                */
1751 
1752                               /* What do we have to do about ::1? */
1753                               switch (in6_addrscope(&ia6->ia_addr.sin6_addr)) {
1754                               case IPV6_ADDR_SCOPE_LINKLOCAL:
1755                                         if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1756                                                   continue;
1757                                         break;
1758                               case IPV6_ADDR_SCOPE_SITELOCAL:
1759                                         if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1760                                                   continue;
1761                                         break;
1762                               case IPV6_ADDR_SCOPE_GLOBAL:
1763                                         if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1764                                                   continue;
1765                                         break;
1766                               default:
1767                                         continue;
1768                               }
1769 
1770                               /*
1771                                * check if anycast is okay.
1772                                * XXX: just experimental.  not in the spec.
1773                                */
1774                               if ((ia6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1775                                   (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1776                                         continue; /* we need only unicast addresses */
1777 
1778                               addrsofif++; /* count the address */
1779                     }
1780                     if (iffound) {
1781                               if_acquire(ifp, psref);
1782                               pserialize_read_exit(s);
1783                               *ifpp = ifp;
1784                               return addrsofif;
1785                     }
1786 
1787                     addrs += addrsofif;
1788           }
1789           pserialize_read_exit(s);
1790 
1791           return addrs;
1792 }
1793 
1794 static int
ni6_store_addrs(struct icmp6_nodeinfo * ni6,struct icmp6_nodeinfo * nni6,struct ifnet * ifp0,int resid)1795 ni6_store_addrs(struct icmp6_nodeinfo *ni6,
1796           struct icmp6_nodeinfo *nni6, struct ifnet *ifp0,
1797           int resid)
1798 {
1799           struct ifnet *ifp;
1800           struct in6_ifaddr *ia6;
1801           struct ifaddr *ifa;
1802           struct ifnet *ifp_dep = NULL;
1803           int copied = 0, allow_deprecated = 0;
1804           u_char *cp = (u_char *)(nni6 + 1);
1805           int niflags = ni6->ni_flags;
1806           u_int32_t ltime;
1807           int s;
1808 
1809           if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1810                     return 0; /* needless to copy */
1811 
1812           s = pserialize_read_enter();
1813           ifp = ifp0 ? ifp0 : IFNET_READER_FIRST();
1814 again:
1815 
1816           for (; ifp; ifp = IFNET_READER_NEXT(ifp))
1817           {
1818                     IFADDR_READER_FOREACH(ifa, ifp) {
1819                               if (ifa->ifa_addr->sa_family != AF_INET6)
1820                                         continue;
1821                               ia6 = (struct in6_ifaddr *)ifa;
1822 
1823                               if ((ia6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1824                                   allow_deprecated == 0) {
1825                                         /*
1826                                          * prefererred address should be put before
1827                                          * deprecated addresses.
1828                                          */
1829 
1830                                         /* record the interface for later search */
1831                                         if (ifp_dep == NULL)
1832                                                   ifp_dep = ifp;
1833 
1834                                         continue;
1835                               }
1836                               else if ((ia6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1837                                          allow_deprecated != 0)
1838                                         continue; /* we now collect deprecated addrs */
1839 
1840                               /* What do we have to do about ::1? */
1841                               switch (in6_addrscope(&ia6->ia_addr.sin6_addr)) {
1842                               case IPV6_ADDR_SCOPE_LINKLOCAL:
1843                                         if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1844                                                   continue;
1845                                         break;
1846                               case IPV6_ADDR_SCOPE_SITELOCAL:
1847                                         if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1848                                                   continue;
1849                                         break;
1850                               case IPV6_ADDR_SCOPE_GLOBAL:
1851                                         if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1852                                                   continue;
1853                                         break;
1854                               default:
1855                                         continue;
1856                               }
1857 
1858                               /*
1859                                * check if anycast is okay.
1860                                * XXX: just experimental.  not in the spec.
1861                                */
1862                               if ((ia6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1863                                   (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1864                                         continue;
1865 
1866                               /* now we can copy the address */
1867                               if (resid < sizeof(struct in6_addr) +
1868                                   sizeof(u_int32_t)) {
1869                                         /*
1870                                          * We give up much more copy.
1871                                          * Set the truncate flag and return.
1872                                          */
1873                                         nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1874                                         goto out;
1875                               }
1876 
1877                               /*
1878                                * Set the TTL of the address.
1879                                * The TTL value should be one of the following
1880                                * according to the specification:
1881                                *
1882                                * 1. The remaining lifetime of a DHCP lease on the
1883                                *    address, or
1884                                * 2. The remaining Valid Lifetime of a prefix from
1885                                *    which the address was derived through Stateless
1886                                *    Autoconfiguration.
1887                                *
1888                                * Note that we currently do not support stateful
1889                                * address configuration by DHCPv6, so the former
1890                                * case can't happen.
1891                                *
1892                                * TTL must be 2^31 > TTL >= 0.
1893                                */
1894                               if (ia6->ia6_lifetime.ia6t_expire == 0)
1895                                         ltime = ND6_INFINITE_LIFETIME;
1896                               else {
1897                                         if (ia6->ia6_lifetime.ia6t_expire >
1898                                             time_uptime)
1899                                                   ltime = ia6->ia6_lifetime.ia6t_expire -
1900                                                       time_uptime;
1901                                         else
1902                                                   ltime = 0;
1903                               }
1904                               if (ltime > 0x7fffffff)
1905                                         ltime = 0x7fffffff;
1906                               ltime = htonl(ltime);
1907 
1908                               memcpy(cp, &ltime, sizeof(u_int32_t));
1909                               cp += sizeof(u_int32_t);
1910 
1911                               /* copy the address itself */
1912                               bcopy(&ia6->ia_addr.sin6_addr, cp,
1913                                     sizeof(struct in6_addr));
1914                               in6_clearscope((struct in6_addr *)cp); /* XXX */
1915                               cp += sizeof(struct in6_addr);
1916 
1917                               resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1918                               copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1919                     }
1920                     if (ifp0) /* we need search only on the specified IF */
1921                               break;
1922           }
1923 
1924           if (allow_deprecated == 0 && ifp_dep != NULL) {
1925                     ifp = ifp_dep;
1926                     allow_deprecated = 1;
1927 
1928                     goto again;
1929           }
1930 out:
1931           pserialize_read_exit(s);
1932           return copied;
1933 }
1934 
1935 /*
1936  * XXX almost dup'ed code with rip6_input.
1937  */
1938 static int
icmp6_rip6_input(struct mbuf ** mp,int off)1939 icmp6_rip6_input(struct mbuf **mp, int off)
1940 {
1941           struct mbuf *m = *mp;
1942           struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1943           struct inpcb *inp;
1944           struct inpcb *last = NULL;
1945           struct sockaddr_in6 rip6src;
1946           struct icmp6_hdr *icmp6;
1947           struct mbuf *n, *opts = NULL;
1948 
1949           IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1950           if (icmp6 == NULL) {
1951                     /* m is already reclaimed */
1952                     return IPPROTO_DONE;
1953           }
1954 
1955           /*
1956            * XXX: the address may have embedded scope zone ID, which should be
1957            * hidden from applications.
1958            */
1959           sockaddr_in6_init(&rip6src, &ip6->ip6_src, 0, 0, 0);
1960           if (sa6_recoverscope(&rip6src)) {
1961                     m_freem(m);
1962                     return IPPROTO_DONE;
1963           }
1964 
1965           TAILQ_FOREACH(inp, &raw6cbtable.inpt_queue, inp_queue) {
1966                     if (inp->inp_af != AF_INET6)
1967                               continue;
1968                     if (in6p_ip6(inp).ip6_nxt != IPPROTO_ICMPV6)
1969                               continue;
1970                     if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)) &&
1971                         !IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp), &ip6->ip6_dst))
1972                               continue;
1973                     if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)) &&
1974                         !IN6_ARE_ADDR_EQUAL(&in6p_faddr(inp), &ip6->ip6_src))
1975                               continue;
1976                     if (in6p_icmp6filt(inp) &&
1977                         ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1978                         in6p_icmp6filt(inp)))
1979                               continue;
1980 
1981                     if (last == NULL) {
1982                               ;
1983                     }
1984 #ifdef IPSEC
1985                     else if (ipsec_used && ipsec_in_reject(m, last)) {
1986                               /* do not inject data into pcb */
1987                     }
1988 #endif
1989                     else if ((n = m_copypacket(m, M_DONTWAIT)) != NULL) {
1990                               if (last->inp_flags & IN6P_CONTROLOPTS ||
1991                                   SOOPT_TIMESTAMP(last->inp_socket->so_options))
1992                                         ip6_savecontrol(last, &opts, ip6, n);
1993                               /* strip intermediate headers */
1994                               m_adj(n, off);
1995                               if (sbappendaddr(&last->inp_socket->so_rcv,
1996                                   sin6tosa(&rip6src), n, opts) == 0) {
1997                                         soroverflow(last->inp_socket);
1998                                         m_freem(n);
1999                                         m_freem(opts);
2000                               } else {
2001                                         sorwakeup(last->inp_socket);
2002                               }
2003                               opts = NULL;
2004                     }
2005 
2006                     last = inp;
2007           }
2008 
2009 #ifdef IPSEC
2010           if (ipsec_used && last && ipsec_in_reject(m, last)) {
2011                     m_freem(m);
2012                     IP6_STATDEC(IP6_STAT_DELIVERED);
2013                     /* do not inject data into pcb */
2014           } else
2015 #endif
2016           if (last) {
2017                     if (last->inp_flags & IN6P_CONTROLOPTS ||
2018                         SOOPT_TIMESTAMP(last->inp_socket->so_options))
2019                               ip6_savecontrol(last, &opts, ip6, m);
2020                     /* strip intermediate headers */
2021                     m_adj(m, off);
2022                     if (sbappendaddr(&last->inp_socket->so_rcv,
2023                         sin6tosa(&rip6src), m, opts) == 0) {
2024                               soroverflow(last->inp_socket);
2025                               m_freem(m);
2026                               m_freem(opts);
2027                     } else {
2028                               sorwakeup(last->inp_socket);
2029                     }
2030           } else {
2031                     m_freem(m);
2032                     IP6_STATDEC(IP6_STAT_DELIVERED);
2033           }
2034           return IPPROTO_DONE;
2035 }
2036 
2037 /*
2038  * Reflect the ip6 packet back to the source.
2039  * OFF points to the icmp6 header, counted from the top of the mbuf.
2040  *
2041  * Note: RFC 1885 required that an echo reply should be truncated if it
2042  * did not fit in with (return) path MTU, and KAME code supported the
2043  * behavior.  However, as a clarification after the RFC, this limitation
2044  * was removed in a revised version of the spec, RFC 2463.  We had kept the
2045  * old behavior, with a (non-default) ifdef block, while the new version of
2046  * the spec was an internet-draft status, and even after the new RFC was
2047  * published.  But it would rather make sense to clean the obsoleted part
2048  * up, and to make the code simpler at this stage.
2049  */
2050 static void
icmp6_reflect(struct mbuf * m,size_t off)2051 icmp6_reflect(struct mbuf *m, size_t off)
2052 {
2053           struct ip6_hdr *ip6;
2054           struct icmp6_hdr *icmp6;
2055           const struct in6_ifaddr *ia;
2056           const struct ip6aux *ip6a;
2057           int plen;
2058           int type, code;
2059           struct ifnet *outif = NULL;
2060           struct in6_addr origdst;
2061           struct ifnet *rcvif;
2062           int s;
2063           bool ip6_src_filled = false;
2064           int flags;
2065 
2066           /* too short to reflect */
2067           if (off < sizeof(struct ip6_hdr)) {
2068                     nd6log(LOG_DEBUG,
2069                         "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2070                         (u_long)off, (u_long)sizeof(struct ip6_hdr),
2071                         __FILE__, __LINE__);
2072                     goto bad;
2073           }
2074 
2075           /*
2076            * If there are extra headers between IPv6 and ICMPv6, strip
2077            * off that header first.
2078            */
2079           CTASSERT(sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) <= MHLEN);
2080           if (off > sizeof(struct ip6_hdr)) {
2081                     size_t l;
2082                     struct ip6_hdr nip6;
2083 
2084                     l = off - sizeof(struct ip6_hdr);
2085                     m_copydata(m, 0, sizeof(nip6), (void *)&nip6);
2086                     m_adj(m, l);
2087                     l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2088                     if (m->m_len < l) {
2089                               if ((m = m_pullup(m, l)) == NULL)
2090                                         return;
2091                     }
2092                     memcpy(mtod(m, void *), (void *)&nip6, sizeof(nip6));
2093           } else {
2094                     size_t l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2095                     if (m->m_len < l) {
2096                               if ((m = m_pullup(m, l)) == NULL)
2097                                         return;
2098                     }
2099           }
2100 
2101           plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2102           ip6 = mtod(m, struct ip6_hdr *);
2103           ip6->ip6_nxt = IPPROTO_ICMPV6;
2104           icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2105           type = icmp6->icmp6_type; /* keep type for statistics */
2106           code = icmp6->icmp6_code; /* ditto. */
2107 
2108           origdst = ip6->ip6_dst;
2109           /*
2110            * ip6_input() drops a packet if its src is multicast.
2111            * So, the src is never multicast.
2112            */
2113           ip6->ip6_dst = ip6->ip6_src;
2114 
2115           /*
2116            * If the incoming packet was addressed directly to us (i.e. unicast),
2117            * use dst as the src for the reply.
2118            * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2119            * (for example) when we encounter an error while forwarding procedure
2120            * destined to a duplicated address of ours.
2121            * Note that ip6_getdstifaddr() may fail if we are in an error handling
2122            * procedure of an outgoing packet of our own, in which case we need
2123            * to search in the ifaddr list.
2124            */
2125           if (IN6_IS_ADDR_MULTICAST(&origdst)) {
2126                     ;
2127           } else if ((ip6a = ip6_getdstifaddr(m)) != NULL) {
2128                     if ((ip6a->ip6a_flags &
2129                          (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2130                               ip6->ip6_src = ip6a->ip6a_src;
2131                               ip6_src_filled = true;
2132                     }
2133           } else {
2134                     union {
2135                               struct sockaddr_in6 sin6;
2136                               struct sockaddr sa;
2137                     } u;
2138                     int _s;
2139                     struct ifaddr *ifa;
2140 
2141                     sockaddr_in6_init(&u.sin6, &origdst, 0, 0, 0);
2142 
2143                     _s = pserialize_read_enter();
2144                     ifa = ifa_ifwithaddr(&u.sa);
2145 
2146                     if (ifa != NULL) {
2147                               ia = ifatoia6(ifa);
2148                               if ((ia->ia6_flags &
2149                                          (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2150                                         ip6->ip6_src = ia->ia_addr.sin6_addr;
2151                                         ip6_src_filled = true;
2152                               }
2153                     }
2154                     pserialize_read_exit(_s);
2155           }
2156 
2157           if (!ip6_src_filled) {
2158                     int e;
2159                     struct sockaddr_in6 sin6;
2160                     struct route ro;
2161 
2162                     /*
2163                      * This case matches to multicasts, our anycast, or unicasts
2164                      * that we do not own.  Select a source address based on the
2165                      * source address of the erroneous packet.
2166                      */
2167                     /* zone ID should be embedded */
2168                     sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0);
2169 
2170                     memset(&ro, 0, sizeof(ro));
2171                     e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, NULL, NULL,
2172                         &ip6->ip6_src);
2173                     rtcache_free(&ro);
2174                     if (e != 0) {
2175                               char ip6buf[INET6_ADDRSTRLEN];
2176                               nd6log(LOG_DEBUG,
2177                                   "source can't be determined: "
2178                                   "dst=%s, error=%d\n",
2179                                   IN6_PRINT(ip6buf, &sin6.sin6_addr), e);
2180                               goto bad;
2181                     }
2182           }
2183 
2184           ip6->ip6_flow = 0;
2185           ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2186           ip6->ip6_vfc |= IPV6_VERSION;
2187           ip6->ip6_nxt = IPPROTO_ICMPV6;
2188           rcvif = m_get_rcvif(m, &s);
2189           if (rcvif) {
2190                     /* XXX: This may not be the outgoing interface */
2191                     ip6->ip6_hlim = ND_IFINFO(rcvif)->chlim;
2192           } else {
2193                     ip6->ip6_hlim = ip6_defhlim;
2194           }
2195           m_put_rcvif(rcvif, &s);
2196 
2197           m->m_pkthdr.csum_flags = 0;
2198           icmp6->icmp6_cksum = 0;
2199           icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2200               sizeof(struct ip6_hdr), plen);
2201 
2202           /*
2203            * XXX option handling
2204            */
2205 
2206           m->m_flags &= ~(M_BCAST|M_MCAST);
2207 
2208           /*
2209            * Note for icmp6_reflect_pmtu == false
2210            * To avoid a "too big" situation at an intermediate router
2211            * and the path MTU discovery process, specify the IPV6_MINMTU flag.
2212            * Note that only echo and node information replies are affected,
2213            * since the length of ICMP6 errors is limited to the minimum MTU.
2214            */
2215           flags = icmp6_reflect_pmtu ? 0 : IPV6_MINMTU;
2216           if (ip6_output(m, NULL, NULL, flags, NULL, NULL, &outif) != 0 &&
2217               outif)
2218                     icmp6_ifstat_inc(outif, ifs6_out_error);
2219           if (outif)
2220                     icmp6_ifoutstat_inc(outif, type, code);
2221 
2222           return;
2223 
2224  bad:
2225           m_freem(m);
2226           return;
2227 }
2228 
2229 static const char *
icmp6_redirect_diag(char * buf,size_t buflen,struct in6_addr * src6,struct in6_addr * dst6,struct in6_addr * tgt6)2230 icmp6_redirect_diag(char *buf, size_t buflen, struct in6_addr *src6,
2231     struct in6_addr *dst6,  struct in6_addr *tgt6)
2232 {
2233           char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
2234           char ip6buft[INET6_ADDRSTRLEN];
2235 
2236           snprintf(buf, buflen, "(src=%s dst=%s tgt=%s)",
2237               IN6_PRINT(ip6bufs, src6), IN6_PRINT(ip6bufd, dst6),
2238               IN6_PRINT(ip6buft, tgt6));
2239           return buf;
2240 }
2241 
2242 static void
icmp6_redirect_input(struct mbuf * m,int off)2243 icmp6_redirect_input(struct mbuf *m, int off)
2244 {
2245           struct ifnet *ifp;
2246           struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2247           struct nd_redirect *nd_rd;
2248           int icmp6len = m->m_pkthdr.len - off;
2249           char *lladdr = NULL;
2250           int lladdrlen = 0;
2251           struct rtentry *rt = NULL;
2252           int is_router;
2253           int is_onlink;
2254           struct in6_addr src6 = ip6->ip6_src;
2255           struct in6_addr redtgt6;
2256           struct in6_addr reddst6;
2257           union nd_opts ndopts;
2258           struct psref psref;
2259           char ip6buf[INET6_ADDRSTRLEN];
2260           char diagbuf[256];
2261 
2262           ifp = m_get_rcvif_psref(m, &psref);
2263           if (ifp == NULL)
2264                     goto freeit;
2265 
2266           /* XXX if we are router, we don't update route by icmp6 redirect */
2267           if (ip6_forwarding)
2268                     goto freeit;
2269           if (!icmp6_rediraccept)
2270                     goto freeit;
2271 
2272           IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2273           if (nd_rd == NULL) {
2274                     ICMP6_STATINC(ICMP6_STAT_TOOSHORT);
2275                     m_put_rcvif_psref(ifp, &psref);
2276                     return;
2277           }
2278           redtgt6 = nd_rd->nd_rd_target;
2279           reddst6 = nd_rd->nd_rd_dst;
2280 
2281           if (in6_setscope(&redtgt6, ifp, NULL) ||
2282               in6_setscope(&reddst6, ifp, NULL)) {
2283                     goto freeit;
2284           }
2285 
2286           /* validation */
2287           if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2288                     nd6log(LOG_ERR,
2289                         "ICMP6 redirect sent from %s rejected; "
2290                         "must be from linklocal\n", IN6_PRINT(ip6buf, &src6));
2291                     goto bad;
2292           }
2293           if (ip6->ip6_hlim != 255) {
2294                     nd6log(LOG_ERR,
2295                         "ICMP6 redirect sent from %s rejected; "
2296                         "hlim=%d (must be 255)\n",
2297                         IN6_PRINT(ip6buf, &src6), ip6->ip6_hlim);
2298                     goto bad;
2299           }
2300 
2301     {
2302           /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2303           struct sockaddr_in6 sin6;
2304           struct in6_addr *gw6;
2305 
2306           sockaddr_in6_init(&sin6, &reddst6, 0, 0, 0);
2307           rt = rtalloc1(sin6tosa(&sin6), 0);
2308           if (rt) {
2309                     if (rt->rt_gateway == NULL ||
2310                         rt->rt_gateway->sa_family != AF_INET6) {
2311                               nd6log(LOG_ERR,
2312                                   "ICMP6 redirect rejected; no route "
2313                                   "with inet6 gateway found for redirect dst: %s\n",
2314                                   icmp6_redirect_diag(diagbuf, sizeof(diagbuf),
2315                                   &src6, &reddst6, &redtgt6));
2316                               rt_unref(rt);
2317                               goto bad;
2318                     }
2319 
2320                     gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2321                     if (memcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2322                               nd6log(LOG_ERR,
2323                                   "ICMP6 redirect rejected; "
2324                                   "not equal to gw-for-src=%s (must be same): %s\n",
2325                                   IN6_PRINT(ip6buf, gw6),
2326                                   icmp6_redirect_diag(diagbuf, sizeof(diagbuf),
2327                                   &src6, &reddst6, &redtgt6));
2328                               rt_unref(rt);
2329                               goto bad;
2330                     }
2331           } else {
2332                     nd6log(LOG_ERR, "ICMP6 redirect rejected; "
2333                         "no route found for redirect dst: %s\n",
2334                         icmp6_redirect_diag(diagbuf, sizeof(diagbuf),
2335                         &src6, &reddst6, &redtgt6));
2336                     goto bad;
2337           }
2338           rt_unref(rt);
2339           rt = NULL;
2340     }
2341 
2342           if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2343                     nd6log(LOG_ERR, "ICMP6 redirect rejected; "
2344                         "redirect dst must be unicast: %s\n",
2345                         icmp6_redirect_diag(diagbuf, sizeof(diagbuf),
2346                         &src6, &reddst6, &redtgt6));
2347                     goto bad;
2348           }
2349 
2350           is_router = is_onlink = 0;
2351           if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2352                     is_router = 1;      /* router case */
2353           if (memcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2354                     is_onlink = 1;      /* on-link destination case */
2355           if (!is_router && !is_onlink) {
2356                     nd6log(LOG_ERR, "ICMP6 redirect rejected; "
2357                         "neither router case nor onlink case: %s\n",
2358                         icmp6_redirect_diag(diagbuf, sizeof(diagbuf),
2359                         &src6, &reddst6, &redtgt6));
2360                     goto bad;
2361           }
2362           /* validation passed */
2363 
2364           icmp6len -= sizeof(*nd_rd);
2365           nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2366           if (nd6_options(&ndopts) < 0) {
2367                     nd6log(LOG_INFO, "invalid ND option, rejected: %s\n",
2368                         icmp6_redirect_diag(diagbuf, sizeof(diagbuf),
2369                         &src6, &reddst6, &redtgt6));
2370                     /* nd6_options have incremented stats */
2371                     goto freeit;
2372           }
2373 
2374           if (ndopts.nd_opts_tgt_lladdr) {
2375                     lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2376                     lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2377           }
2378 
2379           if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2380                     nd6log(LOG_INFO, "lladdrlen mismatch for %s "
2381                         "(if %d, icmp6 packet %d): %s\n",
2382                         IN6_PRINT(ip6buf, &redtgt6),
2383                         ifp->if_addrlen, lladdrlen - 2,
2384                         icmp6_redirect_diag(diagbuf, sizeof(diagbuf),
2385                         &src6, &reddst6, &redtgt6));
2386                     goto bad;
2387           }
2388 
2389           /* RFC 2461 8.3 */
2390           nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2391               is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2392 
2393           m_put_rcvif_psref(ifp, &psref);
2394           ifp = NULL;
2395 
2396           if (!is_onlink) {   /* better router case.  perform rtredirect. */
2397                     /* perform rtredirect */
2398                     struct sockaddr_in6 sdst;
2399                     struct sockaddr_in6 sgw;
2400                     struct sockaddr_in6 ssrc;
2401                     unsigned long rtcount;
2402                     struct rtentry *newrt = NULL;
2403 
2404                     /*
2405                      * do not install redirect route, if the number of entries
2406                      * is too much (> hiwat).  note that, the node (= host) will
2407                      * work just fine even if we do not install redirect route
2408                      * (there will be additional hops, though).
2409                      */
2410                     mutex_enter(&icmp6_mtx);
2411                     rtcount = rt_timer_count(icmp6_redirect_timeout_q);
2412                     if (0 <= ip6_maxdynroutes && rtcount >= ip6_maxdynroutes) {
2413                               mutex_exit(&icmp6_mtx);
2414                               goto freeit;
2415                     }
2416                     if (0 <= icmp6_redirect_hiwat && rtcount > icmp6_redirect_hiwat) {
2417                               mutex_exit(&icmp6_mtx);
2418                               goto freeit;
2419                     } else if (0 <= icmp6_redirect_lowat &&
2420                         rtcount > icmp6_redirect_lowat) {
2421                               /*
2422                                * XXX nuke a victim, install the new one.
2423                                */
2424                     }
2425 
2426                     memset(&sdst, 0, sizeof(sdst));
2427                     memset(&sgw, 0, sizeof(sgw));
2428                     memset(&ssrc, 0, sizeof(ssrc));
2429                     sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2430                     sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2431                         sizeof(struct sockaddr_in6);
2432                     bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2433                     bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2434                     bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2435                     rtredirect(sin6tosa(&sdst), sin6tosa(&sgw), NULL,
2436                         RTF_GATEWAY | RTF_HOST, sin6tosa(&ssrc), &newrt);
2437 
2438                     if (newrt) {
2439                               (void)rt_timer_add(newrt, icmp6_redirect_timeout,
2440                                   icmp6_redirect_timeout_q);
2441                               rt_unref(newrt);
2442                     }
2443                     mutex_exit(&icmp6_mtx);
2444           }
2445           /* finally update cached route in each socket via pfctlinput */
2446           {
2447                     struct sockaddr_in6 sdst;
2448 
2449                     sockaddr_in6_init(&sdst, &reddst6, 0, 0, 0);
2450                     pfctlinput(PRC_REDIRECT_HOST, sin6tosa(&sdst));
2451 #if defined(IPSEC)
2452                     if (ipsec_used)
2453                               key_sa_routechange(sin6tosa(&sdst));
2454 #endif
2455           }
2456 
2457 freeit:
2458           if (ifp != NULL)
2459                     m_put_rcvif_psref(ifp, &psref);
2460           m_freem(m);
2461           return;
2462 
2463 bad:
2464           m_put_rcvif_psref(ifp, &psref);
2465           ICMP6_STATINC(ICMP6_STAT_BADREDIRECT);
2466           m_freem(m);
2467 }
2468 
2469 void
icmp6_redirect_output(struct mbuf * m0,struct rtentry * rt)2470 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2471 {
2472           struct ifnet *ifp;  /* my outgoing interface */
2473           struct in6_addr *ifp_ll6;
2474           struct in6_addr *nexthop;
2475           struct ip6_hdr *sip6;         /* m0 as struct ip6_hdr */
2476           struct mbuf *m = NULL;        /* newly allocated one */
2477           struct ip6_hdr *ip6;          /* m as struct ip6_hdr */
2478           struct nd_redirect *nd_rd;
2479           size_t maxlen;
2480           u_char *p;
2481           struct sockaddr_in6 src_sa;
2482 
2483           icmp6_errcount(ICMP6_STAT_OUTERRHIST, ND_REDIRECT, 0);
2484 
2485           /* if we are not router, we don't send icmp6 redirect */
2486           if (!ip6_forwarding)
2487                     goto fail;
2488 
2489           /* sanity check */
2490           KASSERT(m0 != NULL);
2491           KASSERT(rt != NULL);
2492 
2493           ifp = rt->rt_ifp;
2494 
2495           /*
2496            * Address check:
2497            *  the source address must identify a neighbor, and
2498            *  the destination address must not be a multicast address
2499            *  [RFC 2461, sec 8.2]
2500            */
2501           sip6 = mtod(m0, struct ip6_hdr *);
2502           sockaddr_in6_init(&src_sa, &sip6->ip6_src, 0, 0, 0);
2503           if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2504                     goto fail;
2505           if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2506                     goto fail;          /* what should we do here? */
2507 
2508           /* rate limit */
2509           if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2510                     goto fail;
2511 
2512           /*
2513            * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2514            * we almost always ask for an mbuf cluster for simplicity.
2515            * (MHLEN < IPV6_MMTU is almost always true)
2516            */
2517           MGETHDR(m, M_DONTWAIT, MT_HEADER);
2518           if (m && IPV6_MMTU >= MHLEN) {
2519 #if IPV6_MMTU >= MCLBYTES
2520                     MEXTMALLOC(m, IPV6_MMTU, M_NOWAIT);
2521 #else
2522                     MCLGET(m, M_DONTWAIT);
2523 #endif
2524           }
2525 
2526           if (!m)
2527                     goto fail;
2528           m_reset_rcvif(m);
2529           m->m_len = 0;
2530           maxlen = M_TRAILINGSPACE(m);
2531           maxlen = uimin(IPV6_MMTU, maxlen);
2532 
2533           /* just for safety */
2534           if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct nd_redirect) +
2535               ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2536                     goto fail;
2537           }
2538 
2539           {
2540                     /* get ip6 linklocal address for ifp(my outgoing interface). */
2541                     struct in6_ifaddr *ia;
2542                     int s = pserialize_read_enter();
2543                     if ((ia = in6ifa_ifpforlinklocal(ifp,
2544                                                              IN6_IFF_NOTREADY|
2545                                                              IN6_IFF_ANYCAST)) == NULL) {
2546                               pserialize_read_exit(s);
2547                               goto fail;
2548                     }
2549                     ifp_ll6 = &ia->ia_addr.sin6_addr;
2550                     pserialize_read_exit(s);
2551           }
2552 
2553           /* get ip6 linklocal address for the router. */
2554           if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2555                     struct sockaddr_in6 *sin6;
2556                     sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2557                     nexthop = &sin6->sin6_addr;
2558                     if (!IN6_IS_ADDR_LINKLOCAL(nexthop))
2559                               nexthop = NULL;
2560           } else
2561                     nexthop = NULL;
2562 
2563           /* ip6 */
2564           ip6 = mtod(m, struct ip6_hdr *);
2565           ip6->ip6_flow = 0;
2566           ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2567           ip6->ip6_vfc |= IPV6_VERSION;
2568           /* ip6->ip6_plen will be set later */
2569           ip6->ip6_nxt = IPPROTO_ICMPV6;
2570           ip6->ip6_hlim = 255;
2571           /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2572           bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2573           bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2574 
2575           /* ND Redirect */
2576           nd_rd = (struct nd_redirect *)(ip6 + 1);
2577           nd_rd->nd_rd_type = ND_REDIRECT;
2578           nd_rd->nd_rd_code = 0;
2579           nd_rd->nd_rd_reserved = 0;
2580           if (rt->rt_flags & RTF_GATEWAY) {
2581                     /*
2582                      * nd_rd->nd_rd_target must be a link-local address in
2583                      * better router cases.
2584                      */
2585                     if (!nexthop)
2586                               goto fail;
2587                     bcopy(nexthop, &nd_rd->nd_rd_target,
2588                           sizeof(nd_rd->nd_rd_target));
2589                     bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2590                           sizeof(nd_rd->nd_rd_dst));
2591           } else {
2592                     /* make sure redtgt == reddst */
2593                     nexthop = &sip6->ip6_dst;
2594                     bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2595                           sizeof(nd_rd->nd_rd_target));
2596                     bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2597                           sizeof(nd_rd->nd_rd_dst));
2598           }
2599 
2600           p = (u_char *)(nd_rd + 1);
2601 
2602           {
2603                     /* target lladdr option */
2604                     struct llentry *ln = NULL;
2605                     int len, pad;
2606                     struct nd_opt_hdr *nd_opt;
2607                     char *lladdr;
2608 
2609                     ln = nd6_lookup(nexthop, ifp, false);
2610                     if (ln == NULL)
2611                               goto nolladdropt;
2612                     len = sizeof(*nd_opt) + ifp->if_addrlen;
2613                     len = (len + 7) & ~7;         /* round by 8 */
2614                     pad = len - (sizeof(*nd_opt) + ifp->if_addrlen);
2615 
2616                     /* safety check */
2617                     if (len + (p - (u_char *)ip6) > maxlen) {
2618                               LLE_RUNLOCK(ln);
2619                               goto nolladdropt;
2620                     }
2621 
2622                     if (ln->la_flags & LLE_VALID) {
2623                               nd_opt = (struct nd_opt_hdr *)p;
2624                               nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2625                               nd_opt->nd_opt_len = len >> 3;
2626                               lladdr = (char *)(nd_opt + 1);
2627                               memcpy(lladdr, &ln->ll_addr, ifp->if_addrlen);
2628                               memset(lladdr + ifp->if_addrlen, 0, pad);
2629                               p += len;
2630                     }
2631                     LLE_RUNLOCK(ln);
2632           }
2633 nolladdropt:
2634 
2635           m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2636 
2637           /* just to be safe */
2638           if (m0->m_flags & M_DECRYPTED)
2639                     goto noredhdropt;
2640           if (p - (u_char *)ip6 > maxlen)
2641                     goto noredhdropt;
2642 
2643           {
2644                     /* redirected header option */
2645                     int len;
2646                     struct nd_opt_rd_hdr *nd_opt_rh;
2647 
2648                     /*
2649                      * compute the maximum size for icmp6 redirect header option.
2650                      * XXX room for auth header?
2651                      */
2652                     len = maxlen - (p - (u_char *)ip6);
2653                     len &= ~7;
2654 
2655                     if (len < sizeof(*nd_opt_rh)) {
2656                               goto noredhdropt;
2657                     }
2658 
2659                     /*
2660                      * Redirected header option spec (RFC2461 4.6.3) talks nothing
2661                      * about padding/truncate rule for the original IP packet.
2662                      * From the discussion on IPv6imp in Feb 1999,
2663                      * the consensus was:
2664                      * - "attach as much as possible" is the goal
2665                      * - pad if not aligned (original size can be guessed by
2666                      *   original ip6 header)
2667                      * Following code adds the padding if it is simple enough,
2668                      * and truncates if not.
2669                      */
2670                     if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2671                               /* not enough room, truncate */
2672                               m_adj(m0, (len - sizeof(*nd_opt_rh)) -
2673                                   m0->m_pkthdr.len);
2674                     } else {
2675                               /*
2676                                * enough room, truncate if not aligned.
2677                                * we don't pad here for simplicity.
2678                                */
2679                               int extra;
2680 
2681                               extra = m0->m_pkthdr.len % 8;
2682                               if (extra) {
2683                                         /* truncate */
2684                                         m_adj(m0, -extra);
2685                               }
2686                               len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2687                     }
2688 
2689                     nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2690                     memset(nd_opt_rh, 0, sizeof(*nd_opt_rh));
2691                     nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2692                     nd_opt_rh->nd_opt_rh_len = len >> 3;
2693                     p += sizeof(*nd_opt_rh);
2694                     m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2695 
2696                     /* connect m0 to m */
2697                     m->m_pkthdr.len += m0->m_pkthdr.len;
2698                     m_cat(m, m0);
2699                     m0 = NULL;
2700           }
2701 noredhdropt:
2702           m_freem(m0);
2703           m0 = NULL;
2704 
2705           /* XXX: clear embedded link IDs in the inner header */
2706           in6_clearscope(&sip6->ip6_src);
2707           in6_clearscope(&sip6->ip6_dst);
2708           in6_clearscope(&nd_rd->nd_rd_target);
2709           in6_clearscope(&nd_rd->nd_rd_dst);
2710 
2711           ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2712 
2713           nd_rd->nd_rd_cksum = 0;
2714           nd_rd->nd_rd_cksum =
2715               in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2716 
2717           /* send the packet to outside... */
2718           if (ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL) != 0)
2719                     icmp6_ifstat_inc(ifp, ifs6_out_error);
2720 
2721           icmp6_ifstat_inc(ifp, ifs6_out_msg);
2722           icmp6_ifstat_inc(ifp, ifs6_out_redirect);
2723           ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_REDIRECT);
2724 
2725           return;
2726 
2727 fail:
2728           m_freem(m);
2729           m_freem(m0);
2730 }
2731 
2732 /*
2733  * ICMPv6 socket option processing.
2734  */
2735 int
icmp6_ctloutput(int op,struct socket * so,struct sockopt * sopt)2736 icmp6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
2737 {
2738           int error = 0;
2739           struct inpcb *inp = sotoinpcb(so);
2740 
2741           if (sopt->sopt_level != IPPROTO_ICMPV6)
2742                     return rip6_ctloutput(op, so, sopt);
2743 
2744           switch (op) {
2745           case PRCO_SETOPT:
2746                     switch (sopt->sopt_name) {
2747                     case ICMP6_FILTER:
2748                         {
2749                               struct icmp6_filter fil;
2750 
2751                               error = sockopt_get(sopt, &fil, sizeof(fil));
2752                               if (error)
2753                                         break;
2754                               memcpy(in6p_icmp6filt(inp), &fil,
2755                                   sizeof(struct icmp6_filter));
2756                               error = 0;
2757                               break;
2758                         }
2759 
2760                     default:
2761                               error = ENOPROTOOPT;
2762                               break;
2763                     }
2764                     break;
2765 
2766           case PRCO_GETOPT:
2767                     switch (sopt->sopt_name) {
2768                     case ICMP6_FILTER:
2769                         {
2770                               if (in6p_icmp6filt(inp) == NULL) {
2771                                         error = EINVAL;
2772                                         break;
2773                               }
2774                               error = sockopt_set(sopt, in6p_icmp6filt(inp),
2775                                   sizeof(struct icmp6_filter));
2776                               break;
2777                         }
2778 
2779                     default:
2780                               error = ENOPROTOOPT;
2781                               break;
2782                     }
2783                     break;
2784           }
2785 
2786           return error;
2787 }
2788 
2789 /*
2790  * Perform rate limit check.
2791  * Returns 0 if it is okay to send the icmp6 packet.
2792  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2793  * limitation.
2794  *
2795  * XXX per-destination/type check necessary?
2796  */
2797 static int
icmp6_ratelimit(const struct in6_addr * dst,const int type,const int code)2798 icmp6_ratelimit(
2799           const struct in6_addr *dst,   /* not used at this moment */
2800           const int type,               /* not used at this moment */
2801           const int code)               /* not used at this moment */
2802 {
2803           int ret;
2804 
2805           ret = 0;  /* okay to send */
2806 
2807           /* PPS limit */
2808           if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2809               icmp6errppslim)) {
2810                     /* The packet is subject to rate limit */
2811                     ret++;
2812           }
2813 
2814           return ret;
2815 }
2816 
2817 static struct rtentry *
icmp6_mtudisc_clone(struct sockaddr * dst)2818 icmp6_mtudisc_clone(struct sockaddr *dst)
2819 {
2820           struct rtentry *rt;
2821           int    error;
2822 
2823           rt = rtalloc1(dst, 1);
2824           if (rt == NULL)
2825                     return NULL;
2826 
2827           /* If we didn't get a host route, allocate one */
2828           if ((rt->rt_flags & RTF_HOST) == 0) {
2829                     struct rtentry *nrt;
2830 
2831                     error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL,
2832                         RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
2833                     if (error) {
2834                               rt_unref(rt);
2835                               return NULL;
2836                     }
2837                     nrt->rt_rmx = rt->rt_rmx;
2838                     rt_newmsg_dynamic(RTM_ADD, nrt);
2839                     rt_unref(rt);
2840                     rt = nrt;
2841           }
2842 
2843           mutex_enter(&icmp6_mtx);
2844           error = rt_timer_add(rt, icmp6_mtudisc_timeout,
2845                               icmp6_mtudisc_timeout_q);
2846           mutex_exit(&icmp6_mtx);
2847 
2848           if (error) {
2849                     rt_unref(rt);
2850                     return NULL;
2851           }
2852 
2853           return rt;          /* caller need to call rtfree() */
2854 }
2855 
2856 static void
icmp6_mtudisc_timeout(struct rtentry * rt,struct rttimer * r)2857 icmp6_mtudisc_timeout(struct rtentry *rt, struct rttimer *r)
2858 {
2859           struct rtentry *retrt;
2860 
2861           KASSERT(rt != NULL);
2862           rt_assert_referenced(rt);
2863 
2864           if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
2865               (RTF_DYNAMIC | RTF_HOST)) {
2866                     rtrequest(RTM_DELETE, rt_getkey(rt),
2867                         rt->rt_gateway, rt_mask(rt), rt->rt_flags, &retrt);
2868                     rt_newmsg_dynamic(RTM_DELETE, retrt);
2869                     rt_unref(rt);
2870                     rt_free(retrt);
2871           } else {
2872                     if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
2873                               rt->rt_rmx.rmx_mtu = 0;
2874           }
2875 }
2876 
2877 static void
icmp6_redirect_timeout(struct rtentry * rt,struct rttimer * r)2878 icmp6_redirect_timeout(struct rtentry *rt, struct rttimer *r)
2879 {
2880           struct rtentry *retrt;
2881 
2882           KASSERT(rt != NULL);
2883           rt_assert_referenced(rt);
2884 
2885           if ((rt->rt_flags & (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) ==
2886               (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) {
2887                     rtrequest(RTM_DELETE, rt_getkey(rt),
2888                         rt->rt_gateway, rt_mask(rt), rt->rt_flags, &retrt);
2889                     rt_newmsg_dynamic(RTM_DELETE, retrt);
2890                     rt_unref(rt);
2891                     rt_free(retrt);
2892           }
2893 }
2894 
2895 static int
sysctl_net_inet6_icmp6_stats(SYSCTLFN_ARGS)2896 sysctl_net_inet6_icmp6_stats(SYSCTLFN_ARGS)
2897 {
2898 
2899           return (NETSTAT_SYSCTL(icmp6stat_percpu, ICMP6_NSTATS));
2900 }
2901 
2902 static int
sysctl_net_inet6_icmp6_redirtimeout(SYSCTLFN_ARGS)2903 sysctl_net_inet6_icmp6_redirtimeout(SYSCTLFN_ARGS)
2904 {
2905           int error, tmp;
2906           struct sysctlnode node;
2907 
2908           mutex_enter(&icmp6_mtx);
2909 
2910           node = *rnode;
2911           node.sysctl_data = &tmp;
2912           tmp = icmp6_redirtimeout;
2913           error = sysctl_lookup(SYSCTLFN_CALL(&node));
2914           if (error || newp == NULL)
2915                     goto out;
2916           if (tmp < 0) {
2917                     error = EINVAL;
2918                     goto out;
2919           }
2920           icmp6_redirtimeout = tmp;
2921 
2922           if (icmp6_redirect_timeout_q != NULL) {
2923                     if (icmp6_redirtimeout == 0) {
2924                               rt_timer_queue_destroy(icmp6_redirect_timeout_q);
2925                     } else {
2926                               rt_timer_queue_change(icmp6_redirect_timeout_q,
2927                                   icmp6_redirtimeout);
2928                     }
2929           } else if (icmp6_redirtimeout > 0) {
2930                     icmp6_redirect_timeout_q =
2931                         rt_timer_queue_create(icmp6_redirtimeout);
2932           }
2933           error = 0;
2934 out:
2935           mutex_exit(&icmp6_mtx);
2936           return error;
2937 }
2938 
2939 static void
sysctl_net_inet6_icmp6_setup(struct sysctllog ** clog)2940 sysctl_net_inet6_icmp6_setup(struct sysctllog **clog)
2941 {
2942 
2943           sysctl_createv(clog, 0, NULL, NULL,
2944                            CTLFLAG_PERMANENT,
2945                            CTLTYPE_NODE, "inet6", NULL,
2946                            NULL, 0, NULL, 0,
2947                            CTL_NET, PF_INET6, CTL_EOL);
2948           sysctl_createv(clog, 0, NULL, NULL,
2949                            CTLFLAG_PERMANENT,
2950                            CTLTYPE_NODE, "icmp6",
2951                            SYSCTL_DESCR("ICMPv6 related settings"),
2952                            NULL, 0, NULL, 0,
2953                            CTL_NET, PF_INET6, IPPROTO_ICMPV6, CTL_EOL);
2954 
2955           sysctl_createv(clog, 0, NULL, NULL,
2956                            CTLFLAG_PERMANENT,
2957                            CTLTYPE_STRUCT, "stats",
2958                            SYSCTL_DESCR("ICMPv6 transmission statistics"),
2959                            sysctl_net_inet6_icmp6_stats, 0, NULL, 0,
2960                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2961                            ICMPV6CTL_STATS, CTL_EOL);
2962           sysctl_createv(clog, 0, NULL, NULL,
2963                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2964                            CTLTYPE_INT, "rediraccept",
2965                            SYSCTL_DESCR("Accept and process redirect messages"),
2966                            NULL, 0, &icmp6_rediraccept, 0,
2967                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2968                            ICMPV6CTL_REDIRACCEPT, CTL_EOL);
2969           sysctl_createv(clog, 0, NULL, NULL,
2970                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2971                            CTLTYPE_INT, "redirtimeout",
2972                            SYSCTL_DESCR("Redirect generated route lifetime"),
2973                            sysctl_net_inet6_icmp6_redirtimeout, 0,
2974                            &icmp6_redirtimeout, 0,
2975                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2976                            ICMPV6CTL_REDIRTIMEOUT, CTL_EOL);
2977 #if 0 /* obsoleted */
2978           sysctl_createv(clog, 0, NULL, NULL,
2979                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2980                            CTLTYPE_INT, "errratelimit", NULL,
2981                            NULL, 0, &icmp6_errratelimit, 0,
2982                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2983                            ICMPV6CTL_ERRRATELIMIT, CTL_EOL);
2984 #endif
2985           sysctl_createv(clog, 0, NULL, NULL,
2986                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2987                            CTLTYPE_INT, "nd6_prune",
2988                            SYSCTL_DESCR("Neighbor discovery prune interval"),
2989                            NULL, 0, &nd6_prune, 0,
2990                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2991                            ICMPV6CTL_ND6_PRUNE, CTL_EOL);
2992           sysctl_createv(clog, 0, NULL, NULL,
2993                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2994                            CTLTYPE_INT, "nd6_delay",
2995                            SYSCTL_DESCR("First probe delay time"),
2996                            NULL, 0, &nd6_nd_domain.nd_delay, 0,
2997                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
2998                            ICMPV6CTL_ND6_DELAY, CTL_EOL);
2999           sysctl_createv(clog, 0, NULL, NULL,
3000                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3001                            CTLTYPE_INT, "nd6_mmaxtries",
3002                            SYSCTL_DESCR("Number of multicast discovery attempts"),
3003                            NULL, 0, &nd6_nd_domain.nd_mmaxtries, 0,
3004                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3005                            ICMPV6CTL_ND6_MMAXTRIES, CTL_EOL);
3006           sysctl_createv(clog, 0, NULL, NULL,
3007                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3008                            CTLTYPE_INT, "nd6_umaxtries",
3009                            SYSCTL_DESCR("Number of unicast discovery attempts"),
3010                            NULL, 0, &nd6_nd_domain.nd_umaxtries, 0,
3011                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3012                            ICMPV6CTL_ND6_UMAXTRIES, CTL_EOL);
3013           sysctl_createv(clog, 0, NULL, NULL,
3014                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3015                            CTLTYPE_INT, "nd6_maxnudhint",
3016                            SYSCTL_DESCR("Maximum neighbor unreachable hint count"),
3017                            NULL, 0, &nd6_nd_domain.nd_maxnudhint, 0,
3018                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3019                            ICMPV6CTL_ND6_MAXNUDHINT, CTL_EOL);
3020           sysctl_createv(clog, 0, NULL, NULL,
3021                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3022                            CTLTYPE_INT, "maxqueuelen",
3023                            SYSCTL_DESCR("max packet queue len for a unresolved ND"),
3024                            NULL, 1, &nd6_nd_domain.nd_maxqueuelen, 0,
3025                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3026                            ICMPV6CTL_ND6_MAXQLEN, CTL_EOL);
3027           sysctl_createv(clog, 0, NULL, NULL,
3028                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3029                            CTLTYPE_INT, "nd6_useloopback",
3030                            SYSCTL_DESCR("Use loopback interface for local traffic"),
3031                            NULL, 0, &nd6_useloopback, 0,
3032                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3033                            ICMPV6CTL_ND6_USELOOPBACK, CTL_EOL);
3034 #if 0 /* obsoleted */
3035           sysctl_createv(clog, 0, NULL, NULL,
3036                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3037                            CTLTYPE_INT, "nd6_proxyall", NULL,
3038                            NULL, 0, &nd6_proxyall, 0,
3039                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3040                            ICMPV6CTL_ND6_PROXYALL, CTL_EOL);
3041 #endif
3042           sysctl_createv(clog, 0, NULL, NULL,
3043                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3044                            CTLTYPE_INT, "nodeinfo",
3045                            SYSCTL_DESCR("Respond to node information requests"),
3046                            NULL, 0, &icmp6_nodeinfo, 0,
3047                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3048                            ICMPV6CTL_NODEINFO, CTL_EOL);
3049           sysctl_createv(clog, 0, NULL, NULL,
3050                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3051                            CTLTYPE_INT, "errppslimit",
3052                            SYSCTL_DESCR("Maximum ICMP errors sent per second"),
3053                            NULL, 0, &icmp6errppslim, 0,
3054                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3055                            ICMPV6CTL_ERRPPSLIMIT, CTL_EOL);
3056           sysctl_createv(clog, 0, NULL, NULL,
3057                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3058                            CTLTYPE_INT, "mtudisc_hiwat",
3059                            SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
3060                            NULL, 0, &icmp6_mtudisc_hiwat, 0,
3061                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3062                            ICMPV6CTL_MTUDISC_HIWAT, CTL_EOL);
3063           sysctl_createv(clog, 0, NULL, NULL,
3064                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3065                            CTLTYPE_INT, "mtudisc_lowat",
3066                            SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
3067                            NULL, 0, &icmp6_mtudisc_lowat, 0,
3068                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3069                            ICMPV6CTL_MTUDISC_LOWAT, CTL_EOL);
3070           sysctl_createv(clog, 0, NULL, NULL,
3071                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3072                            CTLTYPE_INT, "nd6_debug",
3073                            SYSCTL_DESCR("Enable neighbor discovery debug output"),
3074                            NULL, 0, &nd6_debug, 0,
3075                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3076                            ICMPV6CTL_ND6_DEBUG, CTL_EOL);
3077           sysctl_createv(clog, 0, NULL, NULL,
3078                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3079                            CTLTYPE_BOOL, "reflect_pmtu",
3080                            SYSCTL_DESCR("Use path MTU Discovery for icmpv6 reflect"),
3081                            NULL, 0, &icmp6_reflect_pmtu, 0,
3082                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3083                            ICMPV6CTL_REFLECT_PMTU, CTL_EOL);
3084           sysctl_createv(clog, 0, NULL, NULL,
3085                            CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
3086                            CTLTYPE_BOOL, "dynamic_rt_msg",
3087                            SYSCTL_DESCR("Send routing message for RTF_DYNAMIC"),
3088                            NULL, 0, &icmp6_dynamic_rt_msg, 0,
3089                            CTL_NET, PF_INET6, IPPROTO_ICMPV6,
3090                            ICMPV6CTL_DYNAMIC_RT_MSG, CTL_EOL);
3091 }
3092 
3093 void
icmp6_statinc(u_int stat)3094 icmp6_statinc(u_int stat)
3095 {
3096 
3097           KASSERT(stat < ICMP6_NSTATS);
3098           ICMP6_STATINC(stat);
3099 }
3100