Annotation of sys/netinet6/nd6_rtr.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: nd6_rtr.c,v 1.43 2007/05/28 23:07:13 pyr Exp $ */
2: /* $KAME: nd6_rtr.c,v 1.97 2001/02/07 11:09:13 itojun 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: #include <sys/param.h>
34: #include <sys/systm.h>
35: #include <sys/malloc.h>
36: #include <sys/mbuf.h>
37: #include <sys/socket.h>
38: #include <sys/sockio.h>
39: #include <sys/time.h>
40: #include <sys/kernel.h>
41: #include <sys/errno.h>
42: #include <sys/ioctl.h>
43: #include <sys/syslog.h>
44: #include <sys/queue.h>
45: #include <dev/rndvar.h>
46:
47: #include <net/if.h>
48: #include <net/if_types.h>
49: #include <net/if_dl.h>
50: #include <net/route.h>
51: #include <net/radix.h>
52:
53: #include <netinet/in.h>
54: #include <netinet6/in6_var.h>
55: #include <netinet/ip6.h>
56: #include <netinet6/ip6_var.h>
57: #include <netinet6/nd6.h>
58: #include <netinet/icmp6.h>
59:
60: #define SDL(s) ((struct sockaddr_dl *)s)
61:
62: static int rtpref(struct nd_defrouter *);
63: static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
64: static struct in6_ifaddr *in6_ifadd(struct nd_prefix *);
65: static struct nd_pfxrouter *pfxrtr_lookup(struct nd_prefix *,
66: struct nd_defrouter *);
67: static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
68: static void pfxrtr_del(struct nd_pfxrouter *);
69: static struct nd_pfxrouter *find_pfxlist_reachable_router(struct nd_prefix *);
70: static void defrouter_delreq(struct nd_defrouter *);
71: static void nd6_rtmsg(int, struct rtentry *);
72:
73: static void in6_init_address_ltimes(struct nd_prefix *,
74: struct in6_addrlifetime *);
75:
76: static int rt6_deleteroute(struct radix_node *, void *);
77:
78: extern int nd6_recalc_reachtm_interval;
79:
80: static struct ifnet *nd6_defifp;
81: int nd6_defifindex;
82:
83: /*
84: * Receive Router Solicitation Message - just for routers.
85: * Router solicitation/advertisement is mostly managed by userland program
86: * (rtadvd) so here we have no function like nd6_ra_output().
87: *
88: * Based on RFC 2461
89: */
90: void
91: nd6_rs_input(m, off, icmp6len)
92: struct mbuf *m;
93: int off, icmp6len;
94: {
95: struct ifnet *ifp = m->m_pkthdr.rcvif;
96: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
97: struct nd_router_solicit *nd_rs;
98: struct in6_addr saddr6 = ip6->ip6_src;
99: #if 0
100: struct in6_addr daddr6 = ip6->ip6_dst;
101: #endif
102: char *lladdr = NULL;
103: int lladdrlen = 0;
104: #if 0
105: struct sockaddr_dl *sdl = (struct sockaddr_dl *)NULL;
106: struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL;
107: struct rtentry *rt = NULL;
108: int is_newentry;
109: #endif
110: union nd_opts ndopts;
111:
112: /* If I'm not a router, ignore it. */
113: if (ip6_accept_rtadv != 0 || !ip6_forwarding)
114: goto freeit;
115:
116: /* Sanity checks */
117: if (ip6->ip6_hlim != 255) {
118: nd6log((LOG_ERR,
119: "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
120: ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
121: ip6_sprintf(&ip6->ip6_dst), ifp->if_xname));
122: goto bad;
123: }
124:
125: /*
126: * Don't update the neighbor cache, if src = ::.
127: * This indicates that the src has no IP address assigned yet.
128: */
129: if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
130: goto freeit;
131:
132: IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
133: if (nd_rs == NULL) {
134: icmp6stat.icp6s_tooshort++;
135: return;
136: }
137:
138: icmp6len -= sizeof(*nd_rs);
139: nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
140: if (nd6_options(&ndopts) < 0) {
141: nd6log((LOG_INFO,
142: "nd6_rs_input: invalid ND option, ignored\n"));
143: /* nd6_options have incremented stats */
144: goto freeit;
145: }
146:
147: if (ndopts.nd_opts_src_lladdr) {
148: lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
149: lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
150: }
151:
152: if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
153: nd6log((LOG_INFO,
154: "nd6_rs_input: lladdrlen mismatch for %s "
155: "(if %d, RS packet %d)\n",
156: ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
157: goto bad;
158: }
159:
160: nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
161:
162: freeit:
163: m_freem(m);
164: return;
165:
166: bad:
167: icmp6stat.icp6s_badrs++;
168: m_freem(m);
169: }
170:
171: /*
172: * Receive Router Advertisement Message.
173: *
174: * Based on RFC 2461
175: * TODO: on-link bit on prefix information
176: * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
177: */
178: void
179: nd6_ra_input(m, off, icmp6len)
180: struct mbuf *m;
181: int off, icmp6len;
182: {
183: struct ifnet *ifp = m->m_pkthdr.rcvif;
184: struct nd_ifinfo *ndi = ND_IFINFO(ifp);
185: struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
186: struct nd_router_advert *nd_ra;
187: struct in6_addr saddr6 = ip6->ip6_src;
188: #if 0
189: struct in6_addr daddr6 = ip6->ip6_dst;
190: int flags; /* = nd_ra->nd_ra_flags_reserved; */
191: int is_managed = ((flags & ND_RA_FLAG_MANAGED) != 0);
192: int is_other = ((flags & ND_RA_FLAG_OTHER) != 0);
193: #endif
194: union nd_opts ndopts;
195: struct nd_defrouter *dr;
196:
197: /*
198: * We only accept RAs only when
199: * the system-wide variable allows the acceptance, and
200: * per-interface variable allows RAs on the receiving interface.
201: */
202: if (ip6_accept_rtadv == 0)
203: goto freeit;
204: if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
205: goto freeit;
206:
207: if (ip6->ip6_hlim != 255) {
208: nd6log((LOG_ERR,
209: "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
210: ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
211: ip6_sprintf(&ip6->ip6_dst), ifp->if_xname));
212: goto bad;
213: }
214:
215: if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
216: nd6log((LOG_ERR,
217: "nd6_ra_input: src %s is not link-local\n",
218: ip6_sprintf(&saddr6)));
219: goto bad;
220: }
221:
222: IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
223: if (nd_ra == NULL) {
224: icmp6stat.icp6s_tooshort++;
225: return;
226: }
227:
228: icmp6len -= sizeof(*nd_ra);
229: nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
230: if (nd6_options(&ndopts) < 0) {
231: nd6log((LOG_INFO,
232: "nd6_ra_input: invalid ND option, ignored\n"));
233: /* nd6_options have incremented stats */
234: goto freeit;
235: }
236:
237: {
238: struct nd_defrouter dr0;
239: u_int32_t advreachable = nd_ra->nd_ra_reachable;
240:
241: Bzero(&dr0, sizeof(dr0));
242: dr0.rtaddr = saddr6;
243: dr0.flags = nd_ra->nd_ra_flags_reserved;
244: dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
245: dr0.expire = time_second + dr0.rtlifetime;
246: dr0.ifp = ifp;
247: /* unspecified or not? (RFC 2461 6.3.4) */
248: if (advreachable) {
249: NTOHL(advreachable);
250: if (advreachable <= MAX_REACHABLE_TIME &&
251: ndi->basereachable != advreachable) {
252: ndi->basereachable = advreachable;
253: ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
254: ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
255: }
256: }
257: if (nd_ra->nd_ra_retransmit)
258: ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
259: if (nd_ra->nd_ra_curhoplimit)
260: ndi->chlim = nd_ra->nd_ra_curhoplimit;
261: dr = defrtrlist_update(&dr0);
262: }
263:
264: /*
265: * prefix
266: */
267: if (ndopts.nd_opts_pi) {
268: struct nd_opt_hdr *pt;
269: struct nd_opt_prefix_info *pi = NULL;
270: struct nd_prefix pr;
271:
272: for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
273: pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
274: pt = (struct nd_opt_hdr *)((caddr_t)pt +
275: (pt->nd_opt_len << 3))) {
276: if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
277: continue;
278: pi = (struct nd_opt_prefix_info *)pt;
279:
280: if (pi->nd_opt_pi_len != 4) {
281: nd6log((LOG_INFO,
282: "nd6_ra_input: invalid option "
283: "len %d for prefix information option, "
284: "ignored\n", pi->nd_opt_pi_len));
285: continue;
286: }
287:
288: if (128 < pi->nd_opt_pi_prefix_len) {
289: nd6log((LOG_INFO,
290: "nd6_ra_input: invalid prefix "
291: "len %d for prefix information option, "
292: "ignored\n", pi->nd_opt_pi_prefix_len));
293: continue;
294: }
295:
296: if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
297: || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
298: nd6log((LOG_INFO,
299: "nd6_ra_input: invalid prefix "
300: "%s, ignored\n",
301: ip6_sprintf(&pi->nd_opt_pi_prefix)));
302: continue;
303: }
304:
305: /* aggregatable unicast address, rfc2374 */
306: if ((pi->nd_opt_pi_prefix.s6_addr8[0] & 0xe0) == 0x20
307: && pi->nd_opt_pi_prefix_len != 64) {
308: nd6log((LOG_INFO,
309: "nd6_ra_input: invalid prefixlen "
310: "%d for rfc2374 prefix %s, ignored\n",
311: pi->nd_opt_pi_prefix_len,
312: ip6_sprintf(&pi->nd_opt_pi_prefix)));
313: continue;
314: }
315:
316: bzero(&pr, sizeof(pr));
317: pr.ndpr_prefix.sin6_family = AF_INET6;
318: pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
319: pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
320: pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
321:
322: pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
323: ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
324: pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
325: ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
326: pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
327: pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
328: pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
329: pr.ndpr_lastupdate = time_second;
330:
331: if (in6_init_prefix_ltimes(&pr))
332: continue; /* prefix lifetime init failed */
333:
334: (void)prelist_update(&pr, dr, m);
335: }
336: }
337:
338: /*
339: * MTU
340: */
341: if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
342: u_long mtu;
343: u_long maxmtu;
344:
345: mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
346:
347: /* lower bound */
348: if (mtu < IPV6_MMTU) {
349: nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
350: "mtu=%lu sent from %s, ignoring\n",
351: mtu, ip6_sprintf(&ip6->ip6_src)));
352: goto skip;
353: }
354:
355: /* upper bound */
356: maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
357: ? ndi->maxmtu : ifp->if_mtu;
358: if (mtu <= maxmtu) {
359: int change = (ndi->linkmtu != mtu);
360:
361: ndi->linkmtu = mtu;
362: if (change) /* in6_maxmtu may change */
363: in6_setmaxmtu();
364: } else {
365: nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
366: "mtu=%lu sent from %s; "
367: "exceeds maxmtu %lu, ignoring\n",
368: mtu, ip6_sprintf(&ip6->ip6_src), maxmtu));
369: }
370: }
371:
372: skip:
373:
374: /*
375: * Source link layer address
376: */
377: {
378: char *lladdr = NULL;
379: int lladdrlen = 0;
380:
381: if (ndopts.nd_opts_src_lladdr) {
382: lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
383: lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
384: }
385:
386: if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
387: nd6log((LOG_INFO,
388: "nd6_ra_input: lladdrlen mismatch for %s "
389: "(if %d, RA packet %d)\n", ip6_sprintf(&saddr6),
390: ifp->if_addrlen, lladdrlen - 2));
391: goto bad;
392: }
393:
394: nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0);
395:
396: /*
397: * Installing a link-layer address might change the state of the
398: * router's neighbor cache, which might also affect our on-link
399: * detection of adveritsed prefixes.
400: */
401: pfxlist_onlink_check();
402: }
403:
404: freeit:
405: m_freem(m);
406: return;
407:
408: bad:
409: icmp6stat.icp6s_badra++;
410: m_freem(m);
411: }
412:
413: /*
414: * default router list processing sub routines
415: */
416:
417: /* tell the change to user processes watching the routing socket. */
418: static void
419: nd6_rtmsg(cmd, rt)
420: int cmd;
421: struct rtentry *rt;
422: {
423: struct rt_addrinfo info;
424:
425: bzero((caddr_t)&info, sizeof(info));
426: info.rti_info[RTAX_DST] = rt_key(rt);
427: info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
428: info.rti_info[RTAX_NETMASK] = rt_mask(rt);
429: if (rt->rt_ifp) {
430: info.rti_info[RTAX_IFP] =
431: TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr;
432: info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
433: }
434:
435: rt_missmsg(cmd, &info, rt->rt_flags, rt->rt_ifp, 0, 0);
436: }
437:
438: void
439: defrouter_addreq(new)
440: struct nd_defrouter *new;
441: {
442: struct sockaddr_in6 def, mask, gate;
443: struct rtentry *newrt = NULL;
444: int s;
445: int error;
446:
447: Bzero(&def, sizeof(def));
448: Bzero(&mask, sizeof(mask));
449: Bzero(&gate, sizeof(gate)); /* for safety */
450:
451: def.sin6_len = mask.sin6_len = gate.sin6_len =
452: sizeof(struct sockaddr_in6);
453: def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
454: gate.sin6_addr = new->rtaddr;
455: gate.sin6_scope_id = 0; /* XXX */
456:
457: s = splsoftnet();
458: error = rtrequest(RTM_ADD, (struct sockaddr *)&def,
459: (struct sockaddr *)&gate, (struct sockaddr *)&mask,
460: RTF_GATEWAY, &newrt, 0);
461: if (newrt) {
462: nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
463: newrt->rt_refcnt--;
464: }
465: if (error == 0)
466: new->installed = 1;
467: splx(s);
468: return;
469: }
470:
471: struct nd_defrouter *
472: defrouter_lookup(addr, ifp)
473: struct in6_addr *addr;
474: struct ifnet *ifp;
475: {
476: struct nd_defrouter *dr;
477:
478: for (dr = TAILQ_FIRST(&nd_defrouter); dr;
479: dr = TAILQ_NEXT(dr, dr_entry)) {
480: if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) {
481: return (dr);
482: }
483: }
484:
485: return (NULL); /* search failed */
486: }
487:
488: void
489: defrtrlist_del(dr)
490: struct nd_defrouter *dr;
491: {
492: struct nd_defrouter *deldr = NULL;
493: struct nd_prefix *pr;
494:
495: /*
496: * Flush all the routing table entries that use the router
497: * as a next hop.
498: */
499: if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */
500: rt6_flush(&dr->rtaddr, dr->ifp);
501:
502: if (dr->installed) {
503: deldr = dr;
504: defrouter_delreq(dr);
505: }
506: TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
507:
508: /*
509: * Also delete all the pointers to the router in each prefix lists.
510: */
511: LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
512: struct nd_pfxrouter *pfxrtr;
513: if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
514: pfxrtr_del(pfxrtr);
515: }
516: pfxlist_onlink_check();
517:
518: /*
519: * If the router is the primary one, choose a new one.
520: * Note that defrouter_select() will remove the current gateway
521: * from the routing table.
522: */
523: if (deldr)
524: defrouter_select();
525:
526: free(dr, M_IP6NDP);
527: }
528:
529: /*
530: * Remove the default route for a given router.
531: * This is just a subroutine function for defrouter_select(), and should
532: * not be called from anywhere else.
533: */
534: static void
535: defrouter_delreq(dr)
536: struct nd_defrouter *dr;
537: {
538: struct sockaddr_in6 def, mask, gw;
539: struct rtentry *oldrt = NULL;
540:
541: #ifdef DIAGNOSTIC
542: if (!dr)
543: panic("dr == NULL in defrouter_delreq");
544: #endif
545:
546: Bzero(&def, sizeof(def));
547: Bzero(&mask, sizeof(mask));
548: Bzero(&gw, sizeof(gw)); /* for safety */
549:
550: def.sin6_len = mask.sin6_len = gw.sin6_len =
551: sizeof(struct sockaddr_in6);
552: def.sin6_family = mask.sin6_family = gw.sin6_family = AF_INET6;
553: gw.sin6_addr = dr->rtaddr;
554: gw.sin6_scope_id = 0; /* XXX */
555:
556: rtrequest(RTM_DELETE, (struct sockaddr *)&def,
557: (struct sockaddr *)&gw,
558: (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt, 0);
559: if (oldrt) {
560: nd6_rtmsg(RTM_DELETE, oldrt);
561: if (oldrt->rt_refcnt <= 0) {
562: /*
563: * XXX: borrowed from the RTM_DELETE case of
564: * rtrequest().
565: */
566: oldrt->rt_refcnt++;
567: rtfree(oldrt);
568: }
569: }
570:
571: dr->installed = 0;
572: }
573:
574: /*
575: * remove all default routes from default router list
576: */
577: void
578: defrouter_reset()
579: {
580: struct nd_defrouter *dr;
581:
582: for (dr = TAILQ_FIRST(&nd_defrouter); dr;
583: dr = TAILQ_NEXT(dr, dr_entry))
584: defrouter_delreq(dr);
585:
586: /*
587: * XXX should we also nuke any default routers in the kernel, by
588: * going through them by rtalloc1()?
589: */
590: }
591:
592: /*
593: * Default Router Selection according to Section 6.3.6 of RFC 2461 and
594: * draft-ietf-ipngwg-router-selection:
595: * 1) Routers that are reachable or probably reachable should be preferred.
596: * If we have more than one (probably) reachable router, prefer ones
597: * with the highest router preference.
598: * 2) When no routers on the list are known to be reachable or
599: * probably reachable, routers SHOULD be selected in a round-robin
600: * fashion, regardless of router preference values.
601: * 3) If the Default Router List is empty, assume that all
602: * destinations are on-link.
603: *
604: * We assume nd_defrouter is sorted by router preference value.
605: * Since the code below covers both with and without router preference cases,
606: * we do not need to classify the cases by ifdef.
607: *
608: * At this moment, we do not try to install more than one default router,
609: * even when the multipath routing is available, because we're not sure about
610: * the benefits for stub hosts comparing to the risk of making the code
611: * complicated and the possibility of introducing bugs.
612: */
613: void
614: defrouter_select()
615: {
616: int s = splsoftnet();
617: struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL;
618: struct rtentry *rt = NULL;
619: struct llinfo_nd6 *ln = NULL;
620:
621: /*
622: * This function should be called only when acting as an autoconfigured
623: * host. Although the remaining part of this function is not effective
624: * if the node is not an autoconfigured host, we explicitly exclude
625: * such cases here for safety.
626: */
627: if (ip6_forwarding || !ip6_accept_rtadv) {
628: nd6log((LOG_WARNING,
629: "defrouter_select: called unexpectedly (forwarding=%d, "
630: "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv));
631: splx(s);
632: return;
633: }
634:
635: /*
636: * Let's handle easy case (3) first:
637: * If default router list is empty, there's nothing to be done.
638: */
639: if (!TAILQ_FIRST(&nd_defrouter)) {
640: splx(s);
641: return;
642: }
643:
644: /*
645: * Search for a (probably) reachable router from the list.
646: * We just pick up the first reachable one (if any), assuming that
647: * the ordering rule of the list described in defrtrlist_update().
648: */
649: for (dr = TAILQ_FIRST(&nd_defrouter); dr;
650: dr = TAILQ_NEXT(dr, dr_entry)) {
651: if (!selected_dr &&
652: (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
653: (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
654: ND6_IS_LLINFO_PROBREACH(ln)) {
655: selected_dr = dr;
656: }
657:
658: if (dr->installed && !installed_dr)
659: installed_dr = dr;
660: else if (dr->installed && installed_dr) {
661: /* this should not happen. warn for diagnosis. */
662: log(LOG_ERR, "defrouter_select: more than one router"
663: " is installed\n");
664: }
665: }
666: /*
667: * If none of the default routers was found to be reachable,
668: * round-robin the list regardless of preference.
669: * Otherwise, if we have an installed router, check if the selected
670: * (reachable) router should really be preferred to the installed one.
671: * We only prefer the new router when the old one is not reachable
672: * or when the new one has a really higher preference value.
673: */
674: if (!selected_dr) {
675: if (!installed_dr || !TAILQ_NEXT(installed_dr, dr_entry))
676: selected_dr = TAILQ_FIRST(&nd_defrouter);
677: else
678: selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
679: } else if (installed_dr &&
680: (rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
681: (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
682: ND6_IS_LLINFO_PROBREACH(ln) &&
683: rtpref(selected_dr) <= rtpref(installed_dr)) {
684: selected_dr = installed_dr;
685: }
686:
687: /*
688: * If the selected router is different than the installed one,
689: * remove the installed router and install the selected one.
690: * Note that the selected router is never NULL here.
691: */
692: if (installed_dr != selected_dr) {
693: if (installed_dr)
694: defrouter_delreq(installed_dr);
695: defrouter_addreq(selected_dr);
696: }
697:
698: splx(s);
699: return;
700: }
701:
702: /*
703: * for default router selection
704: * regards router-preference field as a 2-bit signed integer
705: */
706: static int
707: rtpref(struct nd_defrouter *dr)
708: {
709: #ifdef RTPREF
710: switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) {
711: case ND_RA_FLAG_RTPREF_HIGH:
712: return RTPREF_HIGH;
713: case ND_RA_FLAG_RTPREF_MEDIUM:
714: case ND_RA_FLAG_RTPREF_RSV:
715: return RTPREF_MEDIUM;
716: case ND_RA_FLAG_RTPREF_LOW:
717: return RTPREF_LOW;
718: default:
719: /*
720: * This case should never happen. If it did, it would mean a
721: * serious bug of kernel internal. We thus always bark here.
722: * Or, can we even panic?
723: */
724: log(LOG_ERR, "rtpref: impossible RA flag %x", dr->flags);
725: return RTPREF_INVALID;
726: }
727: /* NOTREACHED */
728: #else
729: return 0;
730: #endif
731: }
732:
733: static struct nd_defrouter *
734: defrtrlist_update(new)
735: struct nd_defrouter *new;
736: {
737: struct nd_defrouter *dr, *n;
738: int s = splsoftnet();
739:
740: if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
741: /* entry exists */
742: if (new->rtlifetime == 0) {
743: defrtrlist_del(dr);
744: dr = NULL;
745: } else {
746: int oldpref = rtpref(dr);
747:
748: /* override */
749: dr->flags = new->flags; /* xxx flag check */
750: dr->rtlifetime = new->rtlifetime;
751: dr->expire = new->expire;
752:
753: /*
754: * If the preference does not change, there's no need
755: * to sort the entries.
756: */
757: if (rtpref(new) == oldpref) {
758: splx(s);
759: return (dr);
760: }
761:
762: /*
763: * preferred router may be changed, so relocate
764: * this router.
765: * XXX: calling TAILQ_REMOVE directly is a bad manner.
766: * However, since defrtrlist_del() has many side
767: * effects, we intentionally do so here.
768: * defrouter_select() below will handle routing
769: * changes later.
770: */
771: TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
772: n = dr;
773: goto insert;
774: }
775: splx(s);
776: return (dr);
777: }
778:
779: /* entry does not exist */
780: if (new->rtlifetime == 0) {
781: splx(s);
782: return (NULL);
783: }
784:
785: n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
786: if (n == NULL) {
787: splx(s);
788: return (NULL);
789: }
790: bzero(n, sizeof(*n));
791: *n = *new;
792:
793: insert:
794: /*
795: * Insert the new router in the Default Router List;
796: * The Default Router List should be in the descending order
797: * of router-preference. Routers with the same preference are
798: * sorted in the arriving time order.
799: */
800:
801: /* insert at the end of the group */
802: for (dr = TAILQ_FIRST(&nd_defrouter); dr;
803: dr = TAILQ_NEXT(dr, dr_entry)) {
804: if (rtpref(n) > rtpref(dr))
805: break;
806: }
807: if (dr)
808: TAILQ_INSERT_BEFORE(dr, n, dr_entry);
809: else
810: TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
811:
812: defrouter_select();
813:
814: splx(s);
815:
816: return (n);
817: }
818:
819: static struct nd_pfxrouter *
820: pfxrtr_lookup(pr, dr)
821: struct nd_prefix *pr;
822: struct nd_defrouter *dr;
823: {
824: struct nd_pfxrouter *search;
825:
826: LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) {
827: if (search->router == dr)
828: break;
829: }
830:
831: return (search);
832: }
833:
834: static void
835: pfxrtr_add(pr, dr)
836: struct nd_prefix *pr;
837: struct nd_defrouter *dr;
838: {
839: struct nd_pfxrouter *new;
840:
841: new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
842: if (new == NULL)
843: return;
844: bzero(new, sizeof(*new));
845: new->router = dr;
846:
847: LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
848:
849: pfxlist_onlink_check();
850: }
851:
852: static void
853: pfxrtr_del(pfr)
854: struct nd_pfxrouter *pfr;
855: {
856: LIST_REMOVE(pfr, pfr_entry);
857: free(pfr, M_IP6NDP);
858: }
859:
860: struct nd_prefix *
861: nd6_prefix_lookup(pr)
862: struct nd_prefix *pr;
863: {
864: struct nd_prefix *search;
865:
866: LIST_FOREACH(search, &nd_prefix, ndpr_entry) {
867: if (pr->ndpr_ifp == search->ndpr_ifp &&
868: pr->ndpr_plen == search->ndpr_plen &&
869: in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
870: &search->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
871: break;
872: }
873: }
874:
875: return (search);
876: }
877:
878: int
879: nd6_prelist_add(pr, dr, newp)
880: struct nd_prefix *pr, **newp;
881: struct nd_defrouter *dr;
882: {
883: struct nd_prefix *new = NULL;
884: int i, s;
885:
886: new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
887: if (new == NULL)
888: return ENOMEM;
889: bzero(new, sizeof(*new));
890: *new = *pr;
891: if (newp != NULL)
892: *newp = new;
893:
894: /* initialization */
895: LIST_INIT(&new->ndpr_advrtrs);
896: in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
897: /* make prefix in the canonical form */
898: for (i = 0; i < 4; i++)
899: new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
900: new->ndpr_mask.s6_addr32[i];
901:
902: s = splsoftnet();
903: /* link ndpr_entry to nd_prefix list */
904: LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
905: splx(s);
906:
907: /* ND_OPT_PI_FLAG_ONLINK processing */
908: if (new->ndpr_raf_onlink) {
909: int e;
910:
911: if ((e = nd6_prefix_onlink(new)) != 0) {
912: nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
913: "the prefix %s/%d on-link on %s (errno=%d)\n",
914: ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
915: pr->ndpr_plen, pr->ndpr_ifp->if_xname, e));
916: /* proceed anyway. XXX: is it correct? */
917: }
918: }
919:
920: if (dr)
921: pfxrtr_add(new, dr);
922:
923: return 0;
924: }
925:
926: void
927: prelist_remove(pr)
928: struct nd_prefix *pr;
929: {
930: struct nd_pfxrouter *pfr, *next;
931: int e, s;
932:
933: /* make sure to invalidate the prefix until it is really freed. */
934: pr->ndpr_vltime = 0;
935: pr->ndpr_pltime = 0;
936: #if 0
937: /*
938: * Though these flags are now meaningless, we'd rather keep the value
939: * not to confuse users when executing "ndp -p".
940: */
941: pr->ndpr_raf_onlink = 0;
942: pr->ndpr_raf_auto = 0;
943: #endif
944: if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
945: (e = nd6_prefix_offlink(pr)) != 0) {
946: nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
947: "on %s, errno=%d\n",
948: ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
949: pr->ndpr_plen, pr->ndpr_ifp->if_xname, e));
950: /* what should we do? */
951: }
952:
953: if (pr->ndpr_refcnt > 0)
954: return; /* notice here? */
955:
956: s = splsoftnet();
957:
958: /* unlink ndpr_entry from nd_prefix list */
959: LIST_REMOVE(pr, ndpr_entry);
960:
961: /* free list of routers that adversed the prefix */
962: for (pfr = LIST_FIRST(&pr->ndpr_advrtrs); pfr != NULL; pfr = next) {
963: next = LIST_NEXT(pfr, pfr_entry);
964:
965: free(pfr, M_IP6NDP);
966: }
967: splx(s);
968:
969: free(pr, M_IP6NDP);
970:
971: pfxlist_onlink_check();
972: }
973:
974: int
975: prelist_update(new, dr, m)
976: struct nd_prefix *new;
977: struct nd_defrouter *dr; /* may be NULL */
978: struct mbuf *m;
979: {
980: struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
981: struct ifaddr *ifa;
982: struct ifnet *ifp = new->ndpr_ifp;
983: struct nd_prefix *pr;
984: int s = splsoftnet();
985: int error = 0;
986: int newprefix = 0;
987: int auth;
988: struct in6_addrlifetime lt6_tmp;
989:
990: auth = 0;
991: if (m) {
992: /*
993: * Authenticity for NA consists authentication for
994: * both IP header and IP datagrams, doesn't it ?
995: */
996: auth = ((m->m_flags & M_AUTH_AH) && (m->m_flags & M_AUTH));
997: }
998:
999: if ((pr = nd6_prefix_lookup(new)) != NULL) {
1000: /*
1001: * nd6_prefix_lookup() ensures that pr and new have the same
1002: * prefix on a same interface.
1003: */
1004:
1005: /*
1006: * Update prefix information. Note that the on-link (L) bit
1007: * and the autonomous (A) bit should NOT be changed from 1
1008: * to 0.
1009: */
1010: if (new->ndpr_raf_onlink == 1)
1011: pr->ndpr_raf_onlink = 1;
1012: if (new->ndpr_raf_auto == 1)
1013: pr->ndpr_raf_auto = 1;
1014: if (new->ndpr_raf_onlink) {
1015: pr->ndpr_vltime = new->ndpr_vltime;
1016: pr->ndpr_pltime = new->ndpr_pltime;
1017: pr->ndpr_preferred = new->ndpr_preferred;
1018: pr->ndpr_expire = new->ndpr_expire;
1019: pr->ndpr_lastupdate = new->ndpr_lastupdate;
1020: }
1021:
1022: if (new->ndpr_raf_onlink &&
1023: (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1024: int e;
1025:
1026: if ((e = nd6_prefix_onlink(pr)) != 0) {
1027: nd6log((LOG_ERR,
1028: "prelist_update: failed to make "
1029: "the prefix %s/%d on-link on %s "
1030: "(errno=%d)\n",
1031: ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1032: pr->ndpr_plen, pr->ndpr_ifp->if_xname, e));
1033: /* proceed anyway. XXX: is it correct? */
1034: }
1035: }
1036:
1037: if (dr && pfxrtr_lookup(pr, dr) == NULL)
1038: pfxrtr_add(pr, dr);
1039: } else {
1040: struct nd_prefix *newpr = NULL;
1041:
1042: newprefix = 1;
1043:
1044: if (new->ndpr_vltime == 0)
1045: goto end;
1046: if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
1047: goto end;
1048:
1049: error = nd6_prelist_add(new, dr, &newpr);
1050: if (error != 0 || newpr == NULL) {
1051: nd6log((LOG_NOTICE, "prelist_update: "
1052: "nd6_prelist_add failed for %s/%d on %s "
1053: "errno=%d, returnpr=%p\n",
1054: ip6_sprintf(&new->ndpr_prefix.sin6_addr),
1055: new->ndpr_plen, new->ndpr_ifp->if_xname,
1056: error, newpr));
1057: goto end; /* we should just give up in this case. */
1058: }
1059:
1060: /*
1061: * XXX: from the ND point of view, we can ignore a prefix
1062: * with the on-link bit being zero. However, we need a
1063: * prefix structure for references from autoconfigured
1064: * addresses. Thus, we explicitly make sure that the prefix
1065: * itself expires now.
1066: */
1067: if (newpr->ndpr_raf_onlink == 0) {
1068: newpr->ndpr_vltime = 0;
1069: newpr->ndpr_pltime = 0;
1070: in6_init_prefix_ltimes(newpr);
1071: }
1072:
1073: pr = newpr;
1074: }
1075:
1076: /*
1077: * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
1078: * Note that pr must be non NULL at this point.
1079: */
1080:
1081: /* 5.5.3 (a). Ignore the prefix without the A bit set. */
1082: if (!new->ndpr_raf_auto)
1083: goto end;
1084:
1085: /*
1086: * 5.5.3 (b). the link-local prefix should have been ignored in
1087: * nd6_ra_input.
1088: */
1089:
1090: /*
1091: * 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime.
1092: * This should have been done in nd6_ra_input.
1093: */
1094:
1095: /*
1096: * 5.5.3 (d). If the prefix advertised does not match the prefix of an
1097: * address already in the list, and the Valid Lifetime is not 0,
1098: * form an address. Note that even a manually configured address
1099: * should reject autoconfiguration of a new address.
1100: */
1101: TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1102: struct in6_ifaddr *ifa6;
1103: int ifa_plen;
1104: u_int32_t storedlifetime;
1105:
1106: if (ifa->ifa_addr->sa_family != AF_INET6)
1107: continue;
1108:
1109: ifa6 = (struct in6_ifaddr *)ifa;
1110:
1111: /*
1112: * Spec is not clear here, but I believe we should concentrate
1113: * on unicast (i.e. not anycast) addresses.
1114: * XXX: other ia6_flags? detached or duplicated?
1115: */
1116: if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
1117: continue;
1118:
1119: ifa_plen = in6_mask2len(&ifa6->ia_prefixmask.sin6_addr, NULL);
1120: if (ifa_plen != new->ndpr_plen ||
1121: !in6_are_prefix_equal(&ifa6->ia_addr.sin6_addr,
1122: &new->ndpr_prefix.sin6_addr, ifa_plen))
1123: continue;
1124:
1125: if (ia6_match == NULL) /* remember the first one */
1126: ia6_match = ifa6;
1127:
1128: if ((ifa6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1129: continue;
1130:
1131: /*
1132: * An already autoconfigured address matched. Now that we
1133: * are sure there is at least one matched address, we can
1134: * proceed to 5.5.3. (e): update the lifetimes according to the
1135: * "two hours" rule and the privacy extension.
1136: */
1137: #define TWOHOUR (120*60)
1138: /*
1139: * RFC2462 introduces the notion of StoredLifetime to the
1140: * "two hours" rule as follows:
1141: * the Lifetime associated with the previously autoconfigured
1142: * address.
1143: * Our interpretation of this definition is "the remaining
1144: * lifetime to expiration at the evaluation time". One might
1145: * be wondering if this interpretation is really conform to the
1146: * RFC, because the text can read that "Lifetimes" are never
1147: * decreased, and our definition of the "storedlifetime" below
1148: * essentially reduces the "Valid Lifetime" advertised in the
1149: * previous RA. But, this is due to the wording of the text,
1150: * and our interpretation is the same as an author's intention.
1151: * See the discussion in the IETF ipngwg ML in August 2001,
1152: * with the Subject "StoredLifetime in RFC 2462".
1153: */
1154: lt6_tmp = ifa6->ia6_lifetime;
1155: if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
1156: storedlifetime = ND6_INFINITE_LIFETIME;
1157: else if (time_second - ifa6->ia6_updatetime >
1158: lt6_tmp.ia6t_vltime) {
1159: /*
1160: * The case of "invalid" address. We should usually
1161: * not see this case.
1162: */
1163: storedlifetime = 0;
1164: } else
1165: storedlifetime = lt6_tmp.ia6t_vltime -
1166: (time_second - ifa6->ia6_updatetime);
1167: if (TWOHOUR < new->ndpr_vltime ||
1168: storedlifetime < new->ndpr_vltime) {
1169: lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1170: } else if (storedlifetime <= TWOHOUR
1171: #if 0
1172: /*
1173: * This condition is logically redundant, so we just
1174: * omit it.
1175: * See IPng 6712, 6717, and 6721.
1176: */
1177: && new->ndpr_vltime <= storedlifetime
1178: #endif
1179: ) {
1180: if (auth) {
1181: lt6_tmp.ia6t_vltime = new->ndpr_vltime;
1182: }
1183: } else {
1184: /*
1185: * new->ndpr_vltime <= TWOHOUR &&
1186: * TWOHOUR < storedlifetime
1187: */
1188: lt6_tmp.ia6t_vltime = TWOHOUR;
1189: }
1190:
1191: /* The 2 hour rule is not imposed for preferred lifetime. */
1192: lt6_tmp.ia6t_pltime = new->ndpr_pltime;
1193:
1194: in6_init_address_ltimes(pr, <6_tmp);
1195:
1196: ifa6->ia6_lifetime = lt6_tmp;
1197: ifa6->ia6_updatetime = time_second;
1198: }
1199: if (ia6_match == NULL && new->ndpr_vltime) {
1200: /*
1201: * No address matched and the valid lifetime is non-zero.
1202: * Create a new address.
1203: */
1204: if ((ia6 = in6_ifadd(new)) != NULL) {
1205: /*
1206: * note that we should use pr (not new) for reference.
1207: */
1208: pr->ndpr_refcnt++;
1209: ia6->ia6_ndpr = pr;
1210:
1211: /*
1212: * A newly added address might affect the status
1213: * of other addresses, so we check and update it.
1214: * XXX: what if address duplication happens?
1215: */
1216: pfxlist_onlink_check();
1217: } else {
1218: /* just set an error. do not bark here. */
1219: error = EADDRNOTAVAIL; /* XXX: might be unused. */
1220: }
1221: }
1222:
1223: end:
1224: splx(s);
1225: return error;
1226: }
1227:
1228: /*
1229: * A supplement function used in the on-link detection below;
1230: * detect if a given prefix has a (probably) reachable advertising router.
1231: * XXX: lengthy function name...
1232: */
1233: static struct nd_pfxrouter *
1234: find_pfxlist_reachable_router(pr)
1235: struct nd_prefix *pr;
1236: {
1237: struct nd_pfxrouter *pfxrtr;
1238: struct rtentry *rt;
1239: struct llinfo_nd6 *ln;
1240:
1241: for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
1242: pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
1243: if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
1244: pfxrtr->router->ifp)) &&
1245: (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
1246: ND6_IS_LLINFO_PROBREACH(ln))
1247: break; /* found */
1248: }
1249:
1250: return (pfxrtr);
1251: }
1252:
1253: /*
1254: * Check if each prefix in the prefix list has at least one available router
1255: * that advertised the prefix (a router is "available" if its neighbor cache
1256: * entry is reachable or probably reachable).
1257: * If the check fails, the prefix may be off-link, because, for example,
1258: * we have moved from the network but the lifetime of the prefix has not
1259: * expired yet. So we should not use the prefix if there is another prefix
1260: * that has an available router.
1261: * But, if there is no prefix that has an available router, we still regards
1262: * all the prefixes as on-link. This is because we can't tell if all the
1263: * routers are simply dead or if we really moved from the network and there
1264: * is no router around us.
1265: */
1266: void
1267: pfxlist_onlink_check()
1268: {
1269: struct nd_prefix *pr;
1270: struct in6_ifaddr *ifa;
1271:
1272: /*
1273: * Check if there is a prefix that has a reachable advertising
1274: * router.
1275: */
1276: LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1277: if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
1278: break;
1279: }
1280: if (pr != NULL || TAILQ_FIRST(&nd_defrouter) != NULL) {
1281: /*
1282: * There is at least one prefix that has a reachable router,
1283: * or at least a router which probably does not advertise
1284: * any prefixes. The latter would be the case when we move
1285: * to a new link where we have a router that does not provide
1286: * prefixes and we configure an address by hand.
1287: * Detach prefixes which have no reachable advertising
1288: * router, and attach other prefixes.
1289: */
1290: LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1291: /* XXX: a link-local prefix should never be detached */
1292: if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1293: continue;
1294:
1295: /*
1296: * we aren't interested in prefixes without the L bit
1297: * set.
1298: */
1299: if (pr->ndpr_raf_onlink == 0)
1300: continue;
1301:
1302: if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1303: find_pfxlist_reachable_router(pr) == NULL)
1304: pr->ndpr_stateflags |= NDPRF_DETACHED;
1305: if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1306: find_pfxlist_reachable_router(pr) != 0)
1307: pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1308: }
1309: } else {
1310: /* there is no prefix that has a reachable router */
1311: LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1312: if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1313: continue;
1314:
1315: if (pr->ndpr_raf_onlink == 0)
1316: continue;
1317:
1318: if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1319: pr->ndpr_stateflags &= ~NDPRF_DETACHED;
1320: }
1321: }
1322:
1323: /*
1324: * Remove each interface route associated with a (just) detached
1325: * prefix, and reinstall the interface route for a (just) attached
1326: * prefix. Note that all attempt of reinstallation does not
1327: * necessarily success, when a same prefix is shared among multiple
1328: * interfaces. Such cases will be handled in nd6_prefix_onlink,
1329: * so we don't have to care about them.
1330: */
1331: LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
1332: int e;
1333:
1334: if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1335: continue;
1336:
1337: if (pr->ndpr_raf_onlink == 0)
1338: continue;
1339:
1340: if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
1341: (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1342: if ((e = nd6_prefix_offlink(pr)) != 0) {
1343: nd6log((LOG_ERR,
1344: "pfxlist_onlink_check: failed to "
1345: "make %s/%d offlink, errno=%d\n",
1346: ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1347: pr->ndpr_plen, e));
1348: }
1349: }
1350: if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
1351: (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
1352: pr->ndpr_raf_onlink) {
1353: if ((e = nd6_prefix_onlink(pr)) != 0) {
1354: nd6log((LOG_ERR,
1355: "pfxlist_onlink_check: failed to "
1356: "make %s/%d offlink, errno=%d\n",
1357: ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1358: pr->ndpr_plen, e));
1359: }
1360: }
1361: }
1362:
1363: /*
1364: * Changes on the prefix status might affect address status as well.
1365: * Make sure that all addresses derived from an attached prefix are
1366: * attached, and that all addresses derived from a detached prefix are
1367: * detached. Note, however, that a manually configured address should
1368: * always be attached.
1369: * The precise detection logic is same as the one for prefixes.
1370: */
1371: for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1372: if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
1373: continue;
1374:
1375: if (ifa->ia6_ndpr == NULL) {
1376: /*
1377: * This can happen when we first configure the address
1378: * (i.e. the address exists, but the prefix does not).
1379: * XXX: complicated relationships...
1380: */
1381: continue;
1382: }
1383:
1384: if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1385: break;
1386: }
1387: if (ifa) {
1388: for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1389: if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1390: continue;
1391:
1392: if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
1393: continue;
1394:
1395: if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
1396: ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1397: else
1398: ifa->ia6_flags |= IN6_IFF_DETACHED;
1399: }
1400: }
1401: else {
1402: for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
1403: if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1404: continue;
1405:
1406: ifa->ia6_flags &= ~IN6_IFF_DETACHED;
1407: }
1408: }
1409: }
1410:
1411: int
1412: nd6_prefix_onlink(pr)
1413: struct nd_prefix *pr;
1414: {
1415: struct ifaddr *ifa;
1416: struct ifnet *ifp = pr->ndpr_ifp;
1417: struct sockaddr_in6 mask6;
1418: struct nd_prefix *opr;
1419: u_long rtflags;
1420: int error = 0;
1421: struct rtentry *rt = NULL;
1422:
1423: /* sanity check */
1424: if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1425: nd6log((LOG_ERR,
1426: "nd6_prefix_onlink: %s/%d is already on-link\n",
1427: ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1428: return (EEXIST);
1429: }
1430:
1431: /*
1432: * Add the interface route associated with the prefix. Before
1433: * installing the route, check if there's the same prefix on another
1434: * interface, and the prefix has already installed the interface route.
1435: * Although such a configuration is expected to be rare, we explicitly
1436: * allow it.
1437: */
1438: LIST_FOREACH(opr, &nd_prefix, ndpr_entry) {
1439: if (opr == pr)
1440: continue;
1441:
1442: if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1443: continue;
1444:
1445: if (opr->ndpr_plen == pr->ndpr_plen &&
1446: in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1447: &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
1448: return (0);
1449: }
1450:
1451: /*
1452: * We prefer link-local addresses as the associated interface address.
1453: */
1454: /* search for a link-local addr */
1455: ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
1456: IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
1457: if (ifa == NULL) {
1458: /* XXX: freebsd does not have ifa_ifwithaf */
1459: TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1460: if (ifa->ifa_addr->sa_family == AF_INET6)
1461: break;
1462: }
1463: /* should we care about ia6_flags? */
1464: }
1465: if (ifa == NULL) {
1466: /*
1467: * This can still happen, when, for example, we receive an RA
1468: * containing a prefix with the L bit set and the A bit clear,
1469: * after removing all IPv6 addresses on the receiving
1470: * interface. This should, of course, be rare though.
1471: */
1472: nd6log((LOG_NOTICE,
1473: "nd6_prefix_onlink: failed to find any ifaddr"
1474: " to add route for a prefix(%s/%d) on %s\n",
1475: ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1476: pr->ndpr_plen, ifp->if_xname));
1477: return (0);
1478: }
1479:
1480: /*
1481: * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
1482: * ifa->ifa_rtrequest = nd6_rtrequest;
1483: */
1484: bzero(&mask6, sizeof(mask6));
1485: mask6.sin6_len = sizeof(mask6);
1486: mask6.sin6_addr = pr->ndpr_mask;
1487: /* rtrequest() will probably set RTF_UP, but we're not sure. */
1488: rtflags = ifa->ifa_flags | RTF_UP;
1489: if (nd6_need_cache(ifp)) {
1490: /* explicitly set in case ifa_flags does not set the flag. */
1491: rtflags |= RTF_CLONING;
1492: } else {
1493: /*
1494: * explicitly clear the cloning bit in case ifa_flags sets it.
1495: */
1496: rtflags &= ~RTF_CLONING;
1497: }
1498: error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
1499: ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt, 0);
1500: if (error == 0) {
1501: if (rt != NULL) /* this should be non NULL, though */
1502: nd6_rtmsg(RTM_ADD, rt);
1503: pr->ndpr_stateflags |= NDPRF_ONLINK;
1504: } else {
1505: nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
1506: " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
1507: "errno = %d\n",
1508: ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
1509: pr->ndpr_plen, ifp->if_xname,
1510: ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
1511: ip6_sprintf(&mask6.sin6_addr), rtflags, error));
1512: }
1513:
1514: if (rt != NULL)
1515: rt->rt_refcnt--;
1516:
1517: return (error);
1518: }
1519:
1520: int
1521: nd6_prefix_offlink(pr)
1522: struct nd_prefix *pr;
1523: {
1524: int error = 0;
1525: struct ifnet *ifp = pr->ndpr_ifp;
1526: struct nd_prefix *opr;
1527: struct sockaddr_in6 sa6, mask6;
1528: struct rtentry *rt = NULL;
1529:
1530: /* sanity check */
1531: if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1532: nd6log((LOG_ERR,
1533: "nd6_prefix_offlink: %s/%d is already off-link\n",
1534: ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
1535: return (EEXIST);
1536: }
1537:
1538: bzero(&sa6, sizeof(sa6));
1539: sa6.sin6_family = AF_INET6;
1540: sa6.sin6_len = sizeof(sa6);
1541: bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
1542: sizeof(struct in6_addr));
1543: bzero(&mask6, sizeof(mask6));
1544: mask6.sin6_family = AF_INET6;
1545: mask6.sin6_len = sizeof(sa6);
1546: bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
1547: error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
1548: (struct sockaddr *)&mask6, 0, &rt, 0);
1549: if (error == 0) {
1550: pr->ndpr_stateflags &= ~NDPRF_ONLINK;
1551:
1552: /* report the route deletion to the routing socket. */
1553: if (rt != NULL)
1554: nd6_rtmsg(RTM_DELETE, rt);
1555:
1556: /*
1557: * There might be the same prefix on another interface,
1558: * the prefix which could not be on-link just because we have
1559: * the interface route (see comments in nd6_prefix_onlink).
1560: * If there's one, try to make the prefix on-link on the
1561: * interface.
1562: */
1563: LIST_FOREACH(opr, &nd_prefix, ndpr_entry) {
1564: if (opr == pr)
1565: continue;
1566:
1567: if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
1568: continue;
1569:
1570: /*
1571: * KAME specific: detached prefixes should not be
1572: * on-link.
1573: */
1574: if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
1575: continue;
1576:
1577: if (opr->ndpr_plen == pr->ndpr_plen &&
1578: in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
1579: &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
1580: int e;
1581:
1582: if ((e = nd6_prefix_onlink(opr)) != 0) {
1583: nd6log((LOG_ERR,
1584: "nd6_prefix_offlink: failed to "
1585: "recover a prefix %s/%d from %s "
1586: "to %s (errno = %d)\n",
1587: ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
1588: opr->ndpr_plen, ifp->if_xname,
1589: opr->ndpr_ifp->if_xname, e));
1590: }
1591: }
1592: }
1593: } else {
1594: /* XXX: can we still set the NDPRF_ONLINK flag? */
1595: nd6log((LOG_ERR,
1596: "nd6_prefix_offlink: failed to delete route: "
1597: "%s/%d on %s (errno = %d)\n",
1598: ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, ifp->if_xname,
1599: error));
1600: }
1601:
1602: if (rt != NULL) {
1603: if (rt->rt_refcnt <= 0) {
1604: /* XXX: we should free the entry ourselves. */
1605: rt->rt_refcnt++;
1606: rtfree(rt);
1607: }
1608: }
1609:
1610: return (error);
1611: }
1612:
1613: static struct in6_ifaddr *
1614: in6_ifadd(pr)
1615: struct nd_prefix *pr;
1616: {
1617: struct ifnet *ifp = pr->ndpr_ifp;
1618: struct ifaddr *ifa;
1619: struct in6_aliasreq ifra;
1620: struct in6_ifaddr *ia, *ib;
1621: int error, plen0;
1622: struct in6_addr mask;
1623: int prefixlen = pr->ndpr_plen;
1624:
1625: in6_prefixlen2mask(&mask, prefixlen);
1626:
1627: /*
1628: * find a link-local address (will be interface ID).
1629: * Is it really mandatory? Theoretically, a global or a site-local
1630: * address can be configured without a link-local address, if we
1631: * have a unique interface identifier...
1632: *
1633: * it is not mandatory to have a link-local address, we can generate
1634: * interface identifier on the fly. we do this because:
1635: * (1) it should be the easiest way to find interface identifier.
1636: * (2) RFC2462 5.4 suggesting the use of the same interface identifier
1637: * for multiple addresses on a single interface, and possible shortcut
1638: * of DAD. we omitted DAD for this reason in the past.
1639: * (3) a user can prevent autoconfiguration of global address
1640: * by removing link-local address by hand (this is partly because we
1641: * don't have other way to control the use of IPv6 on a interface.
1642: * this has been our design choice - cf. NRL's "ifconfig auto").
1643: * (4) it is easier to manage when an interface has addresses
1644: * with the same interface identifier, than to have multiple addresses
1645: * with different interface identifiers.
1646: */
1647: ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
1648: if (ifa)
1649: ib = (struct in6_ifaddr *)ifa;
1650: else
1651: return NULL;
1652:
1653: #if 0 /* don't care link local addr state, and always do DAD */
1654: /* if link-local address is not eligible, do not autoconfigure. */
1655: if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) {
1656: printf("in6_ifadd: link-local address not ready\n");
1657: return NULL;
1658: }
1659: #endif
1660:
1661: /* prefixlen + ifidlen must be equal to 128 */
1662: plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
1663: if (prefixlen != plen0) {
1664: nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
1665: "(prefix=%d ifid=%d)\n",
1666: ifp->if_xname, prefixlen, 128 - plen0));
1667: return NULL;
1668: }
1669:
1670: /* make ifaddr */
1671:
1672: bzero(&ifra, sizeof(ifra));
1673: /*
1674: * in6_update_ifa() does not use ifra_name, but we accurately set it
1675: * for safety.
1676: */
1677: strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name));
1678: ifra.ifra_addr.sin6_family = AF_INET6;
1679: ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
1680: /* prefix */
1681: bcopy(&pr->ndpr_prefix.sin6_addr, &ifra.ifra_addr.sin6_addr,
1682: sizeof(ifra.ifra_addr.sin6_addr));
1683: ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
1684: ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
1685: ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
1686: ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
1687:
1688: /* interface ID */
1689: ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
1690: (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
1691: ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
1692: (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
1693: ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
1694: (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
1695: ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
1696: (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
1697:
1698: /* new prefix mask. */
1699: ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1700: ifra.ifra_prefixmask.sin6_family = AF_INET6;
1701: bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
1702: sizeof(ifra.ifra_prefixmask.sin6_addr));
1703:
1704: /*
1705: * lifetime.
1706: * XXX: in6_init_address_ltimes would override these values later.
1707: * We should reconsider this logic.
1708: */
1709: ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
1710: ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
1711:
1712: /* XXX: scope zone ID? */
1713:
1714: ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
1715:
1716: /* allocate ifaddr structure, link into chain, etc. */
1717: if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
1718: nd6log((LOG_ERR,
1719: "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
1720: ip6_sprintf(&ifra.ifra_addr.sin6_addr), ifp->if_xname,
1721: error));
1722: return (NULL); /* ifaddr must not have been allocated. */
1723: }
1724:
1725: ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
1726:
1727: return (ia); /* this is always non-NULL */
1728: }
1729:
1730: int
1731: in6_init_prefix_ltimes(struct nd_prefix *ndpr)
1732: {
1733:
1734: /* check if preferred lifetime > valid lifetime. RFC2462 5.5.3 (c) */
1735: if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) {
1736: nd6log((LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime"
1737: "(%d) is greater than valid lifetime(%d)\n",
1738: (u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime));
1739: return (EINVAL);
1740: }
1741: if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
1742: ndpr->ndpr_preferred = 0;
1743: else
1744: ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
1745: if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
1746: ndpr->ndpr_expire = 0;
1747: else
1748: ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
1749:
1750: return 0;
1751: }
1752:
1753: static void
1754: in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
1755: {
1756:
1757: /* Valid lifetime must not be updated unless explicitly specified. */
1758: /* init ia6t_expire */
1759: if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
1760: lt6->ia6t_expire = 0;
1761: else {
1762: lt6->ia6t_expire = time_second;
1763: lt6->ia6t_expire += lt6->ia6t_vltime;
1764: }
1765:
1766: /* init ia6t_preferred */
1767: if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
1768: lt6->ia6t_preferred = 0;
1769: else {
1770: lt6->ia6t_preferred = time_second;
1771: lt6->ia6t_preferred += lt6->ia6t_pltime;
1772: }
1773: }
1774:
1775: /*
1776: * Delete all the routing table entries that use the specified gateway.
1777: * XXX: this function causes search through all entries of routing table, so
1778: * it shouldn't be called when acting as a router.
1779: */
1780: void
1781: rt6_flush(gateway, ifp)
1782: struct in6_addr *gateway;
1783: struct ifnet *ifp;
1784: {
1785: struct radix_node_head *rnh = rt_gettable(AF_INET6, 0);
1786: int s = splsoftnet();
1787:
1788: /* We'll care only link-local addresses */
1789: if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
1790: splx(s);
1791: return;
1792: }
1793: /* XXX: hack for KAME's link-local address kludge */
1794: gateway->s6_addr16[1] = htons(ifp->if_index);
1795:
1796: rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
1797: splx(s);
1798: }
1799:
1800: static int
1801: rt6_deleteroute(rn, arg)
1802: struct radix_node *rn;
1803: void *arg;
1804: {
1805: #define SIN6(s) ((struct sockaddr_in6 *)s)
1806: struct rtentry *rt = (struct rtentry *)rn;
1807: struct in6_addr *gate = (struct in6_addr *)arg;
1808:
1809: if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
1810: return (0);
1811:
1812: if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr))
1813: return (0);
1814:
1815: /*
1816: * Do not delete a static route.
1817: * XXX: this seems to be a bit ad-hoc. Should we consider the
1818: * 'cloned' bit instead?
1819: */
1820: if ((rt->rt_flags & RTF_STATIC) != 0)
1821: return (0);
1822:
1823: /*
1824: * We delete only host route. This means, in particular, we don't
1825: * delete default route.
1826: */
1827: if ((rt->rt_flags & RTF_HOST) == 0)
1828: return (0);
1829:
1830: return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
1831: rt_mask(rt), rt->rt_flags, 0, 0));
1832: #undef SIN6
1833: }
1834:
1835: int
1836: nd6_setdefaultiface(ifindex)
1837: int ifindex;
1838: {
1839: int error = 0;
1840:
1841: if (ifindex < 0 || if_indexlim <= ifindex)
1842: return (EINVAL);
1843: if (ifindex != 0 && !ifindex2ifnet[ifindex])
1844: return (EINVAL);
1845:
1846: if (nd6_defifindex != ifindex) {
1847: nd6_defifindex = ifindex;
1848: if (nd6_defifindex > 0) {
1849: nd6_defifp = ifindex2ifnet[nd6_defifindex];
1850: } else
1851: nd6_defifp = NULL;
1852: }
1853:
1854: return (error);
1855: }
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