net: gre: provide multicast mappings for ipv4 and ipv6
[linux-2.6.git] / net / ipv6 / ndisc.c
1 /*
2  *      Neighbour Discovery for IPv6
3  *      Linux INET6 implementation
4  *
5  *      Authors:
6  *      Pedro Roque             <roque@di.fc.ul.pt>
7  *      Mike Shaver             <shaver@ingenia.com>
8  *
9  *      This program is free software; you can redistribute it and/or
10  *      modify it under the terms of the GNU General Public License
11  *      as published by the Free Software Foundation; either version
12  *      2 of the License, or (at your option) any later version.
13  */
14
15 /*
16  *      Changes:
17  *
18  *      Pierre Ynard                    :       export userland ND options
19  *                                              through netlink (RDNSS support)
20  *      Lars Fenneberg                  :       fixed MTU setting on receipt
21  *                                              of an RA.
22  *      Janos Farkas                    :       kmalloc failure checks
23  *      Alexey Kuznetsov                :       state machine reworked
24  *                                              and moved to net/core.
25  *      Pekka Savola                    :       RFC2461 validation
26  *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
27  */
28
29 /* Set to 3 to get tracing... */
30 #define ND_DEBUG 1
31
32 #define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
33 #define ND_NOPRINTK(x...) do { ; } while(0)
34 #define ND_PRINTK0 ND_PRINTK
35 #define ND_PRINTK1 ND_NOPRINTK
36 #define ND_PRINTK2 ND_NOPRINTK
37 #define ND_PRINTK3 ND_NOPRINTK
38 #if ND_DEBUG >= 1
39 #undef ND_PRINTK1
40 #define ND_PRINTK1 ND_PRINTK
41 #endif
42 #if ND_DEBUG >= 2
43 #undef ND_PRINTK2
44 #define ND_PRINTK2 ND_PRINTK
45 #endif
46 #if ND_DEBUG >= 3
47 #undef ND_PRINTK3
48 #define ND_PRINTK3 ND_PRINTK
49 #endif
50
51 #include <linux/module.h>
52 #include <linux/errno.h>
53 #include <linux/types.h>
54 #include <linux/socket.h>
55 #include <linux/sockios.h>
56 #include <linux/sched.h>
57 #include <linux/net.h>
58 #include <linux/in6.h>
59 #include <linux/route.h>
60 #include <linux/init.h>
61 #include <linux/rcupdate.h>
62 #include <linux/slab.h>
63 #ifdef CONFIG_SYSCTL
64 #include <linux/sysctl.h>
65 #endif
66
67 #include <linux/if_addr.h>
68 #include <linux/if_arp.h>
69 #include <linux/ipv6.h>
70 #include <linux/icmpv6.h>
71 #include <linux/jhash.h>
72
73 #include <net/sock.h>
74 #include <net/snmp.h>
75
76 #include <net/ipv6.h>
77 #include <net/protocol.h>
78 #include <net/ndisc.h>
79 #include <net/ip6_route.h>
80 #include <net/addrconf.h>
81 #include <net/icmp.h>
82
83 #include <net/netlink.h>
84 #include <linux/rtnetlink.h>
85
86 #include <net/flow.h>
87 #include <net/ip6_checksum.h>
88 #include <net/inet_common.h>
89 #include <linux/proc_fs.h>
90
91 #include <linux/netfilter.h>
92 #include <linux/netfilter_ipv6.h>
93
94 static u32 ndisc_hash(const void *pkey,
95                       const struct net_device *dev,
96                       __u32 rnd);
97 static int ndisc_constructor(struct neighbour *neigh);
98 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
99 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
100 static int pndisc_constructor(struct pneigh_entry *n);
101 static void pndisc_destructor(struct pneigh_entry *n);
102 static void pndisc_redo(struct sk_buff *skb);
103
104 static const struct neigh_ops ndisc_generic_ops = {
105         .family =               AF_INET6,
106         .solicit =              ndisc_solicit,
107         .error_report =         ndisc_error_report,
108         .output =               neigh_resolve_output,
109         .connected_output =     neigh_connected_output,
110         .hh_output =            dev_queue_xmit,
111         .queue_xmit =           dev_queue_xmit,
112 };
113
114 static const struct neigh_ops ndisc_hh_ops = {
115         .family =               AF_INET6,
116         .solicit =              ndisc_solicit,
117         .error_report =         ndisc_error_report,
118         .output =               neigh_resolve_output,
119         .connected_output =     neigh_resolve_output,
120         .hh_output =            dev_queue_xmit,
121         .queue_xmit =           dev_queue_xmit,
122 };
123
124
125 static const struct neigh_ops ndisc_direct_ops = {
126         .family =               AF_INET6,
127         .output =               dev_queue_xmit,
128         .connected_output =     dev_queue_xmit,
129         .hh_output =            dev_queue_xmit,
130         .queue_xmit =           dev_queue_xmit,
131 };
132
133 struct neigh_table nd_tbl = {
134         .family =       AF_INET6,
135         .entry_size =   sizeof(struct neighbour) + sizeof(struct in6_addr),
136         .key_len =      sizeof(struct in6_addr),
137         .hash =         ndisc_hash,
138         .constructor =  ndisc_constructor,
139         .pconstructor = pndisc_constructor,
140         .pdestructor =  pndisc_destructor,
141         .proxy_redo =   pndisc_redo,
142         .id =           "ndisc_cache",
143         .parms = {
144                 .tbl                    = &nd_tbl,
145                 .base_reachable_time    = ND_REACHABLE_TIME,
146                 .retrans_time           = ND_RETRANS_TIMER,
147                 .gc_staletime           = 60 * HZ,
148                 .reachable_time         = ND_REACHABLE_TIME,
149                 .delay_probe_time       = 5 * HZ,
150                 .queue_len              = 3,
151                 .ucast_probes           = 3,
152                 .mcast_probes           = 3,
153                 .anycast_delay          = 1 * HZ,
154                 .proxy_delay            = (8 * HZ) / 10,
155                 .proxy_qlen             = 64,
156         },
157         .gc_interval =    30 * HZ,
158         .gc_thresh1 =    128,
159         .gc_thresh2 =    512,
160         .gc_thresh3 =   1024,
161 };
162
163 /* ND options */
164 struct ndisc_options {
165         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
166 #ifdef CONFIG_IPV6_ROUTE_INFO
167         struct nd_opt_hdr *nd_opts_ri;
168         struct nd_opt_hdr *nd_opts_ri_end;
169 #endif
170         struct nd_opt_hdr *nd_useropts;
171         struct nd_opt_hdr *nd_useropts_end;
172 };
173
174 #define nd_opts_src_lladdr      nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
175 #define nd_opts_tgt_lladdr      nd_opt_array[ND_OPT_TARGET_LL_ADDR]
176 #define nd_opts_pi              nd_opt_array[ND_OPT_PREFIX_INFO]
177 #define nd_opts_pi_end          nd_opt_array[__ND_OPT_PREFIX_INFO_END]
178 #define nd_opts_rh              nd_opt_array[ND_OPT_REDIRECT_HDR]
179 #define nd_opts_mtu             nd_opt_array[ND_OPT_MTU]
180
181 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
182
183 /*
184  * Return the padding between the option length and the start of the
185  * link addr.  Currently only IP-over-InfiniBand needs this, although
186  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
187  * also need a pad of 2.
188  */
189 static int ndisc_addr_option_pad(unsigned short type)
190 {
191         switch (type) {
192         case ARPHRD_INFINIBAND: return 2;
193         default:                return 0;
194         }
195 }
196
197 static inline int ndisc_opt_addr_space(struct net_device *dev)
198 {
199         return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
200 }
201
202 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
203                                   unsigned short addr_type)
204 {
205         int space = NDISC_OPT_SPACE(data_len);
206         int pad   = ndisc_addr_option_pad(addr_type);
207
208         opt[0] = type;
209         opt[1] = space>>3;
210
211         memset(opt + 2, 0, pad);
212         opt   += pad;
213         space -= pad;
214
215         memcpy(opt+2, data, data_len);
216         data_len += 2;
217         opt += data_len;
218         if ((space -= data_len) > 0)
219                 memset(opt, 0, space);
220         return opt + space;
221 }
222
223 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
224                                             struct nd_opt_hdr *end)
225 {
226         int type;
227         if (!cur || !end || cur >= end)
228                 return NULL;
229         type = cur->nd_opt_type;
230         do {
231                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
232         } while(cur < end && cur->nd_opt_type != type);
233         return cur <= end && cur->nd_opt_type == type ? cur : NULL;
234 }
235
236 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
237 {
238         return opt->nd_opt_type == ND_OPT_RDNSS;
239 }
240
241 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
242                                              struct nd_opt_hdr *end)
243 {
244         if (!cur || !end || cur >= end)
245                 return NULL;
246         do {
247                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
248         } while(cur < end && !ndisc_is_useropt(cur));
249         return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
250 }
251
252 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
253                                                  struct ndisc_options *ndopts)
254 {
255         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
256
257         if (!nd_opt || opt_len < 0 || !ndopts)
258                 return NULL;
259         memset(ndopts, 0, sizeof(*ndopts));
260         while (opt_len) {
261                 int l;
262                 if (opt_len < sizeof(struct nd_opt_hdr))
263                         return NULL;
264                 l = nd_opt->nd_opt_len << 3;
265                 if (opt_len < l || l == 0)
266                         return NULL;
267                 switch (nd_opt->nd_opt_type) {
268                 case ND_OPT_SOURCE_LL_ADDR:
269                 case ND_OPT_TARGET_LL_ADDR:
270                 case ND_OPT_MTU:
271                 case ND_OPT_REDIRECT_HDR:
272                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
273                                 ND_PRINTK2(KERN_WARNING
274                                            "%s(): duplicated ND6 option found: type=%d\n",
275                                            __func__,
276                                            nd_opt->nd_opt_type);
277                         } else {
278                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
279                         }
280                         break;
281                 case ND_OPT_PREFIX_INFO:
282                         ndopts->nd_opts_pi_end = nd_opt;
283                         if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
284                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
285                         break;
286 #ifdef CONFIG_IPV6_ROUTE_INFO
287                 case ND_OPT_ROUTE_INFO:
288                         ndopts->nd_opts_ri_end = nd_opt;
289                         if (!ndopts->nd_opts_ri)
290                                 ndopts->nd_opts_ri = nd_opt;
291                         break;
292 #endif
293                 default:
294                         if (ndisc_is_useropt(nd_opt)) {
295                                 ndopts->nd_useropts_end = nd_opt;
296                                 if (!ndopts->nd_useropts)
297                                         ndopts->nd_useropts = nd_opt;
298                         } else {
299                                 /*
300                                  * Unknown options must be silently ignored,
301                                  * to accommodate future extension to the
302                                  * protocol.
303                                  */
304                                 ND_PRINTK2(KERN_NOTICE
305                                            "%s(): ignored unsupported option; type=%d, len=%d\n",
306                                            __func__,
307                                            nd_opt->nd_opt_type, nd_opt->nd_opt_len);
308                         }
309                 }
310                 opt_len -= l;
311                 nd_opt = ((void *)nd_opt) + l;
312         }
313         return ndopts;
314 }
315
316 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
317                                       struct net_device *dev)
318 {
319         u8 *lladdr = (u8 *)(p + 1);
320         int lladdrlen = p->nd_opt_len << 3;
321         int prepad = ndisc_addr_option_pad(dev->type);
322         if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
323                 return NULL;
324         return lladdr + prepad;
325 }
326
327 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
328 {
329         switch (dev->type) {
330         case ARPHRD_ETHER:
331         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
332         case ARPHRD_FDDI:
333                 ipv6_eth_mc_map(addr, buf);
334                 return 0;
335         case ARPHRD_IEEE802_TR:
336                 ipv6_tr_mc_map(addr,buf);
337                 return 0;
338         case ARPHRD_ARCNET:
339                 ipv6_arcnet_mc_map(addr, buf);
340                 return 0;
341         case ARPHRD_INFINIBAND:
342                 ipv6_ib_mc_map(addr, dev->broadcast, buf);
343                 return 0;
344         case ARPHRD_IPGRE:
345                 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
346         default:
347                 if (dir) {
348                         memcpy(buf, dev->broadcast, dev->addr_len);
349                         return 0;
350                 }
351         }
352         return -EINVAL;
353 }
354
355 EXPORT_SYMBOL(ndisc_mc_map);
356
357 static u32 ndisc_hash(const void *pkey,
358                       const struct net_device *dev,
359                       __u32 hash_rnd)
360 {
361         const u32 *p32 = pkey;
362         u32 addr_hash, i;
363
364         addr_hash = 0;
365         for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
366                 addr_hash ^= *p32++;
367
368         return jhash_2words(addr_hash, dev->ifindex, hash_rnd);
369 }
370
371 static int ndisc_constructor(struct neighbour *neigh)
372 {
373         struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
374         struct net_device *dev = neigh->dev;
375         struct inet6_dev *in6_dev;
376         struct neigh_parms *parms;
377         int is_multicast = ipv6_addr_is_multicast(addr);
378
379         rcu_read_lock();
380         in6_dev = in6_dev_get(dev);
381         if (in6_dev == NULL) {
382                 rcu_read_unlock();
383                 return -EINVAL;
384         }
385
386         parms = in6_dev->nd_parms;
387         __neigh_parms_put(neigh->parms);
388         neigh->parms = neigh_parms_clone(parms);
389         rcu_read_unlock();
390
391         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
392         if (!dev->header_ops) {
393                 neigh->nud_state = NUD_NOARP;
394                 neigh->ops = &ndisc_direct_ops;
395                 neigh->output = neigh->ops->queue_xmit;
396         } else {
397                 if (is_multicast) {
398                         neigh->nud_state = NUD_NOARP;
399                         ndisc_mc_map(addr, neigh->ha, dev, 1);
400                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
401                         neigh->nud_state = NUD_NOARP;
402                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
403                         if (dev->flags&IFF_LOOPBACK)
404                                 neigh->type = RTN_LOCAL;
405                 } else if (dev->flags&IFF_POINTOPOINT) {
406                         neigh->nud_state = NUD_NOARP;
407                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
408                 }
409                 if (dev->header_ops->cache)
410                         neigh->ops = &ndisc_hh_ops;
411                 else
412                         neigh->ops = &ndisc_generic_ops;
413                 if (neigh->nud_state&NUD_VALID)
414                         neigh->output = neigh->ops->connected_output;
415                 else
416                         neigh->output = neigh->ops->output;
417         }
418         in6_dev_put(in6_dev);
419         return 0;
420 }
421
422 static int pndisc_constructor(struct pneigh_entry *n)
423 {
424         struct in6_addr *addr = (struct in6_addr*)&n->key;
425         struct in6_addr maddr;
426         struct net_device *dev = n->dev;
427
428         if (dev == NULL || __in6_dev_get(dev) == NULL)
429                 return -EINVAL;
430         addrconf_addr_solict_mult(addr, &maddr);
431         ipv6_dev_mc_inc(dev, &maddr);
432         return 0;
433 }
434
435 static void pndisc_destructor(struct pneigh_entry *n)
436 {
437         struct in6_addr *addr = (struct in6_addr*)&n->key;
438         struct in6_addr maddr;
439         struct net_device *dev = n->dev;
440
441         if (dev == NULL || __in6_dev_get(dev) == NULL)
442                 return;
443         addrconf_addr_solict_mult(addr, &maddr);
444         ipv6_dev_mc_dec(dev, &maddr);
445 }
446
447 struct sk_buff *ndisc_build_skb(struct net_device *dev,
448                                 const struct in6_addr *daddr,
449                                 const struct in6_addr *saddr,
450                                 struct icmp6hdr *icmp6h,
451                                 const struct in6_addr *target,
452                                 int llinfo)
453 {
454         struct net *net = dev_net(dev);
455         struct sock *sk = net->ipv6.ndisc_sk;
456         struct sk_buff *skb;
457         struct icmp6hdr *hdr;
458         int len;
459         int err;
460         u8 *opt;
461
462         if (!dev->addr_len)
463                 llinfo = 0;
464
465         len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
466         if (llinfo)
467                 len += ndisc_opt_addr_space(dev);
468
469         skb = sock_alloc_send_skb(sk,
470                                   (MAX_HEADER + sizeof(struct ipv6hdr) +
471                                    len + LL_ALLOCATED_SPACE(dev)),
472                                   1, &err);
473         if (!skb) {
474                 ND_PRINTK0(KERN_ERR
475                            "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
476                            __func__, err);
477                 return NULL;
478         }
479
480         skb_reserve(skb, LL_RESERVED_SPACE(dev));
481         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
482
483         skb->transport_header = skb->tail;
484         skb_put(skb, len);
485
486         hdr = (struct icmp6hdr *)skb_transport_header(skb);
487         memcpy(hdr, icmp6h, sizeof(*hdr));
488
489         opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
490         if (target) {
491                 ipv6_addr_copy((struct in6_addr *)opt, target);
492                 opt += sizeof(*target);
493         }
494
495         if (llinfo)
496                 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
497                                        dev->addr_len, dev->type);
498
499         hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
500                                            IPPROTO_ICMPV6,
501                                            csum_partial(hdr,
502                                                         len, 0));
503
504         return skb;
505 }
506
507 EXPORT_SYMBOL(ndisc_build_skb);
508
509 void ndisc_send_skb(struct sk_buff *skb,
510                     struct net_device *dev,
511                     struct neighbour *neigh,
512                     const struct in6_addr *daddr,
513                     const struct in6_addr *saddr,
514                     struct icmp6hdr *icmp6h)
515 {
516         struct flowi6 fl6;
517         struct dst_entry *dst;
518         struct net *net = dev_net(dev);
519         struct sock *sk = net->ipv6.ndisc_sk;
520         struct inet6_dev *idev;
521         int err;
522         u8 type;
523
524         type = icmp6h->icmp6_type;
525
526         icmpv6_flow_init(sk, &fl6, type, saddr, daddr, dev->ifindex);
527
528         dst = icmp6_dst_alloc(dev, neigh, daddr);
529         if (!dst) {
530                 kfree_skb(skb);
531                 return;
532         }
533
534         dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
535         if (IS_ERR(dst)) {
536                 kfree_skb(skb);
537                 return;
538         }
539
540         skb_dst_set(skb, dst);
541
542         idev = in6_dev_get(dst->dev);
543         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
544
545         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
546                       dst_output);
547         if (!err) {
548                 ICMP6MSGOUT_INC_STATS(net, idev, type);
549                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
550         }
551
552         if (likely(idev != NULL))
553                 in6_dev_put(idev);
554 }
555
556 EXPORT_SYMBOL(ndisc_send_skb);
557
558 /*
559  *      Send a Neighbour Discover packet
560  */
561 static void __ndisc_send(struct net_device *dev,
562                          struct neighbour *neigh,
563                          const struct in6_addr *daddr,
564                          const struct in6_addr *saddr,
565                          struct icmp6hdr *icmp6h, const struct in6_addr *target,
566                          int llinfo)
567 {
568         struct sk_buff *skb;
569
570         skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
571         if (!skb)
572                 return;
573
574         ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
575 }
576
577 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
578                           const struct in6_addr *daddr,
579                           const struct in6_addr *solicited_addr,
580                           int router, int solicited, int override, int inc_opt)
581 {
582         struct in6_addr tmpaddr;
583         struct inet6_ifaddr *ifp;
584         const struct in6_addr *src_addr;
585         struct icmp6hdr icmp6h = {
586                 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
587         };
588
589         /* for anycast or proxy, solicited_addr != src_addr */
590         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
591         if (ifp) {
592                 src_addr = solicited_addr;
593                 if (ifp->flags & IFA_F_OPTIMISTIC)
594                         override = 0;
595                 inc_opt |= ifp->idev->cnf.force_tllao;
596                 in6_ifa_put(ifp);
597         } else {
598                 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
599                                        inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
600                                        &tmpaddr))
601                         return;
602                 src_addr = &tmpaddr;
603         }
604
605         icmp6h.icmp6_router = router;
606         icmp6h.icmp6_solicited = solicited;
607         icmp6h.icmp6_override = override;
608
609         __ndisc_send(dev, neigh, daddr, src_addr,
610                      &icmp6h, solicited_addr,
611                      inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
612 }
613
614 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
615                    const struct in6_addr *solicit,
616                    const struct in6_addr *daddr, const struct in6_addr *saddr)
617 {
618         struct in6_addr addr_buf;
619         struct icmp6hdr icmp6h = {
620                 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
621         };
622
623         if (saddr == NULL) {
624                 if (ipv6_get_lladdr(dev, &addr_buf,
625                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
626                         return;
627                 saddr = &addr_buf;
628         }
629
630         __ndisc_send(dev, neigh, daddr, saddr,
631                      &icmp6h, solicit,
632                      !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
633 }
634
635 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
636                    const struct in6_addr *daddr)
637 {
638         struct icmp6hdr icmp6h = {
639                 .icmp6_type = NDISC_ROUTER_SOLICITATION,
640         };
641         int send_sllao = dev->addr_len;
642
643 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
644         /*
645          * According to section 2.2 of RFC 4429, we must not
646          * send router solicitations with a sllao from
647          * optimistic addresses, but we may send the solicitation
648          * if we don't include the sllao.  So here we check
649          * if our address is optimistic, and if so, we
650          * suppress the inclusion of the sllao.
651          */
652         if (send_sllao) {
653                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
654                                                            dev, 1);
655                 if (ifp) {
656                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
657                                 send_sllao = 0;
658                         }
659                         in6_ifa_put(ifp);
660                 } else {
661                         send_sllao = 0;
662                 }
663         }
664 #endif
665         __ndisc_send(dev, NULL, daddr, saddr,
666                      &icmp6h, NULL,
667                      send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
668 }
669
670
671 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
672 {
673         /*
674          *      "The sender MUST return an ICMP
675          *       destination unreachable"
676          */
677         dst_link_failure(skb);
678         kfree_skb(skb);
679 }
680
681 /* Called with locked neigh: either read or both */
682
683 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
684 {
685         struct in6_addr *saddr = NULL;
686         struct in6_addr mcaddr;
687         struct net_device *dev = neigh->dev;
688         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
689         int probes = atomic_read(&neigh->probes);
690
691         if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
692                 saddr = &ipv6_hdr(skb)->saddr;
693
694         if ((probes -= neigh->parms->ucast_probes) < 0) {
695                 if (!(neigh->nud_state & NUD_VALID)) {
696                         ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
697                                    __func__, target);
698                 }
699                 ndisc_send_ns(dev, neigh, target, target, saddr);
700         } else if ((probes -= neigh->parms->app_probes) < 0) {
701 #ifdef CONFIG_ARPD
702                 neigh_app_ns(neigh);
703 #endif
704         } else {
705                 addrconf_addr_solict_mult(target, &mcaddr);
706                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
707         }
708 }
709
710 static int pndisc_is_router(const void *pkey,
711                             struct net_device *dev)
712 {
713         struct pneigh_entry *n;
714         int ret = -1;
715
716         read_lock_bh(&nd_tbl.lock);
717         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
718         if (n)
719                 ret = !!(n->flags & NTF_ROUTER);
720         read_unlock_bh(&nd_tbl.lock);
721
722         return ret;
723 }
724
725 static void ndisc_recv_ns(struct sk_buff *skb)
726 {
727         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
728         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
729         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
730         u8 *lladdr = NULL;
731         u32 ndoptlen = skb->tail - (skb->transport_header +
732                                     offsetof(struct nd_msg, opt));
733         struct ndisc_options ndopts;
734         struct net_device *dev = skb->dev;
735         struct inet6_ifaddr *ifp;
736         struct inet6_dev *idev = NULL;
737         struct neighbour *neigh;
738         int dad = ipv6_addr_any(saddr);
739         int inc;
740         int is_router = -1;
741
742         if (ipv6_addr_is_multicast(&msg->target)) {
743                 ND_PRINTK2(KERN_WARNING
744                            "ICMPv6 NS: multicast target address");
745                 return;
746         }
747
748         /*
749          * RFC2461 7.1.1:
750          * DAD has to be destined for solicited node multicast address.
751          */
752         if (dad &&
753             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
754               daddr->s6_addr32[1] == htonl(0x00000000) &&
755               daddr->s6_addr32[2] == htonl(0x00000001) &&
756               daddr->s6_addr [12] == 0xff )) {
757                 ND_PRINTK2(KERN_WARNING
758                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
759                 return;
760         }
761
762         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
763                 ND_PRINTK2(KERN_WARNING
764                            "ICMPv6 NS: invalid ND options\n");
765                 return;
766         }
767
768         if (ndopts.nd_opts_src_lladdr) {
769                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
770                 if (!lladdr) {
771                         ND_PRINTK2(KERN_WARNING
772                                    "ICMPv6 NS: invalid link-layer address length\n");
773                         return;
774                 }
775
776                 /* RFC2461 7.1.1:
777                  *      If the IP source address is the unspecified address,
778                  *      there MUST NOT be source link-layer address option
779                  *      in the message.
780                  */
781                 if (dad) {
782                         ND_PRINTK2(KERN_WARNING
783                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
784                         return;
785                 }
786         }
787
788         inc = ipv6_addr_is_multicast(daddr);
789
790         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
791         if (ifp) {
792
793                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
794                         if (dad) {
795                                 if (dev->type == ARPHRD_IEEE802_TR) {
796                                         const unsigned char *sadr;
797                                         sadr = skb_mac_header(skb);
798                                         if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
799                                             sadr[9] == dev->dev_addr[1] &&
800                                             sadr[10] == dev->dev_addr[2] &&
801                                             sadr[11] == dev->dev_addr[3] &&
802                                             sadr[12] == dev->dev_addr[4] &&
803                                             sadr[13] == dev->dev_addr[5]) {
804                                                 /* looped-back to us */
805                                                 goto out;
806                                         }
807                                 }
808
809                                 /*
810                                  * We are colliding with another node
811                                  * who is doing DAD
812                                  * so fail our DAD process
813                                  */
814                                 addrconf_dad_failure(ifp);
815                                 return;
816                         } else {
817                                 /*
818                                  * This is not a dad solicitation.
819                                  * If we are an optimistic node,
820                                  * we should respond.
821                                  * Otherwise, we should ignore it.
822                                  */
823                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
824                                         goto out;
825                         }
826                 }
827
828                 idev = ifp->idev;
829         } else {
830                 struct net *net = dev_net(dev);
831
832                 idev = in6_dev_get(dev);
833                 if (!idev) {
834                         /* XXX: count this drop? */
835                         return;
836                 }
837
838                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
839                     (idev->cnf.forwarding &&
840                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
841                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
842                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
843                             skb->pkt_type != PACKET_HOST &&
844                             inc != 0 &&
845                             idev->nd_parms->proxy_delay != 0) {
846                                 /*
847                                  * for anycast or proxy,
848                                  * sender should delay its response
849                                  * by a random time between 0 and
850                                  * MAX_ANYCAST_DELAY_TIME seconds.
851                                  * (RFC2461) -- yoshfuji
852                                  */
853                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
854                                 if (n)
855                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
856                                 goto out;
857                         }
858                 } else
859                         goto out;
860         }
861
862         if (is_router < 0)
863                 is_router = !!idev->cnf.forwarding;
864
865         if (dad) {
866                 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
867                               is_router, 0, (ifp != NULL), 1);
868                 goto out;
869         }
870
871         if (inc)
872                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
873         else
874                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
875
876         /*
877          *      update / create cache entry
878          *      for the source address
879          */
880         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
881                                !inc || lladdr || !dev->addr_len);
882         if (neigh)
883                 neigh_update(neigh, lladdr, NUD_STALE,
884                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
885                              NEIGH_UPDATE_F_OVERRIDE);
886         if (neigh || !dev->header_ops) {
887                 ndisc_send_na(dev, neigh, saddr, &msg->target,
888                               is_router,
889                               1, (ifp != NULL && inc), inc);
890                 if (neigh)
891                         neigh_release(neigh);
892         }
893
894 out:
895         if (ifp)
896                 in6_ifa_put(ifp);
897         else
898                 in6_dev_put(idev);
899 }
900
901 static void ndisc_recv_na(struct sk_buff *skb)
902 {
903         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
904         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
905         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
906         u8 *lladdr = NULL;
907         u32 ndoptlen = skb->tail - (skb->transport_header +
908                                     offsetof(struct nd_msg, opt));
909         struct ndisc_options ndopts;
910         struct net_device *dev = skb->dev;
911         struct inet6_ifaddr *ifp;
912         struct neighbour *neigh;
913
914         if (skb->len < sizeof(struct nd_msg)) {
915                 ND_PRINTK2(KERN_WARNING
916                            "ICMPv6 NA: packet too short\n");
917                 return;
918         }
919
920         if (ipv6_addr_is_multicast(&msg->target)) {
921                 ND_PRINTK2(KERN_WARNING
922                            "ICMPv6 NA: target address is multicast.\n");
923                 return;
924         }
925
926         if (ipv6_addr_is_multicast(daddr) &&
927             msg->icmph.icmp6_solicited) {
928                 ND_PRINTK2(KERN_WARNING
929                            "ICMPv6 NA: solicited NA is multicasted.\n");
930                 return;
931         }
932
933         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
934                 ND_PRINTK2(KERN_WARNING
935                            "ICMPv6 NS: invalid ND option\n");
936                 return;
937         }
938         if (ndopts.nd_opts_tgt_lladdr) {
939                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
940                 if (!lladdr) {
941                         ND_PRINTK2(KERN_WARNING
942                                    "ICMPv6 NA: invalid link-layer address length\n");
943                         return;
944                 }
945         }
946         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
947         if (ifp) {
948                 if (ifp->flags & IFA_F_TENTATIVE) {
949                         addrconf_dad_failure(ifp);
950                         return;
951                 }
952                 /* What should we make now? The advertisement
953                    is invalid, but ndisc specs say nothing
954                    about it. It could be misconfiguration, or
955                    an smart proxy agent tries to help us :-)
956
957                    We should not print the error if NA has been
958                    received from loopback - it is just our own
959                    unsolicited advertisement.
960                  */
961                 if (skb->pkt_type != PACKET_LOOPBACK)
962                         ND_PRINTK1(KERN_WARNING
963                            "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
964                            &ifp->addr, ifp->idev->dev->name);
965                 in6_ifa_put(ifp);
966                 return;
967         }
968         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
969
970         if (neigh) {
971                 u8 old_flags = neigh->flags;
972                 struct net *net = dev_net(dev);
973
974                 if (neigh->nud_state & NUD_FAILED)
975                         goto out;
976
977                 /*
978                  * Don't update the neighbor cache entry on a proxy NA from
979                  * ourselves because either the proxied node is off link or it
980                  * has already sent a NA to us.
981                  */
982                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
983                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
984                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
985                         /* XXX: idev->cnf.prixy_ndp */
986                         goto out;
987                 }
988
989                 neigh_update(neigh, lladdr,
990                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
991                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
992                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
993                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
994                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
995
996                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
997                         /*
998                          * Change: router to host
999                          */
1000                         struct rt6_info *rt;
1001                         rt = rt6_get_dflt_router(saddr, dev);
1002                         if (rt)
1003                                 ip6_del_rt(rt);
1004                 }
1005
1006 out:
1007                 neigh_release(neigh);
1008         }
1009 }
1010
1011 static void ndisc_recv_rs(struct sk_buff *skb)
1012 {
1013         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1014         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1015         struct neighbour *neigh;
1016         struct inet6_dev *idev;
1017         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1018         struct ndisc_options ndopts;
1019         u8 *lladdr = NULL;
1020
1021         if (skb->len < sizeof(*rs_msg))
1022                 return;
1023
1024         idev = in6_dev_get(skb->dev);
1025         if (!idev) {
1026                 if (net_ratelimit())
1027                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1028                 return;
1029         }
1030
1031         /* Don't accept RS if we're not in router mode */
1032         if (!idev->cnf.forwarding)
1033                 goto out;
1034
1035         /*
1036          * Don't update NCE if src = ::;
1037          * this implies that the source node has no ip address assigned yet.
1038          */
1039         if (ipv6_addr_any(saddr))
1040                 goto out;
1041
1042         /* Parse ND options */
1043         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1044                 if (net_ratelimit())
1045                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1046                 goto out;
1047         }
1048
1049         if (ndopts.nd_opts_src_lladdr) {
1050                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1051                                              skb->dev);
1052                 if (!lladdr)
1053                         goto out;
1054         }
1055
1056         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1057         if (neigh) {
1058                 neigh_update(neigh, lladdr, NUD_STALE,
1059                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1060                              NEIGH_UPDATE_F_OVERRIDE|
1061                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1062                 neigh_release(neigh);
1063         }
1064 out:
1065         in6_dev_put(idev);
1066 }
1067
1068 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1069 {
1070         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1071         struct sk_buff *skb;
1072         struct nlmsghdr *nlh;
1073         struct nduseroptmsg *ndmsg;
1074         struct net *net = dev_net(ra->dev);
1075         int err;
1076         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1077                                     + (opt->nd_opt_len << 3));
1078         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1079
1080         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1081         if (skb == NULL) {
1082                 err = -ENOBUFS;
1083                 goto errout;
1084         }
1085
1086         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1087         if (nlh == NULL) {
1088                 goto nla_put_failure;
1089         }
1090
1091         ndmsg = nlmsg_data(nlh);
1092         ndmsg->nduseropt_family = AF_INET6;
1093         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1094         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1095         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1096         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1097
1098         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1099
1100         NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1101                 &ipv6_hdr(ra)->saddr);
1102         nlmsg_end(skb, nlh);
1103
1104         rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1105         return;
1106
1107 nla_put_failure:
1108         nlmsg_free(skb);
1109         err = -EMSGSIZE;
1110 errout:
1111         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1112 }
1113
1114 static inline int accept_ra(struct inet6_dev *in6_dev)
1115 {
1116         /*
1117          * If forwarding is enabled, RA are not accepted unless the special
1118          * hybrid mode (accept_ra=2) is enabled.
1119          */
1120         if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2)
1121                 return 0;
1122
1123         return in6_dev->cnf.accept_ra;
1124 }
1125
1126 static void ndisc_router_discovery(struct sk_buff *skb)
1127 {
1128         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1129         struct neighbour *neigh = NULL;
1130         struct inet6_dev *in6_dev;
1131         struct rt6_info *rt = NULL;
1132         int lifetime;
1133         struct ndisc_options ndopts;
1134         int optlen;
1135         unsigned int pref = 0;
1136
1137         __u8 * opt = (__u8 *)(ra_msg + 1);
1138
1139         optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1140
1141         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1142                 ND_PRINTK2(KERN_WARNING
1143                            "ICMPv6 RA: source address is not link-local.\n");
1144                 return;
1145         }
1146         if (optlen < 0) {
1147                 ND_PRINTK2(KERN_WARNING
1148                            "ICMPv6 RA: packet too short\n");
1149                 return;
1150         }
1151
1152 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1153         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1154                 ND_PRINTK2(KERN_WARNING
1155                            "ICMPv6 RA: from host or unauthorized router\n");
1156                 return;
1157         }
1158 #endif
1159
1160         /*
1161          *      set the RA_RECV flag in the interface
1162          */
1163
1164         in6_dev = in6_dev_get(skb->dev);
1165         if (in6_dev == NULL) {
1166                 ND_PRINTK0(KERN_ERR
1167                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1168                            skb->dev->name);
1169                 return;
1170         }
1171
1172         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1173                 in6_dev_put(in6_dev);
1174                 ND_PRINTK2(KERN_WARNING
1175                            "ICMP6 RA: invalid ND options\n");
1176                 return;
1177         }
1178
1179         if (!accept_ra(in6_dev))
1180                 goto skip_linkparms;
1181
1182 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1183         /* skip link-specific parameters from interior routers */
1184         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1185                 goto skip_linkparms;
1186 #endif
1187
1188         if (in6_dev->if_flags & IF_RS_SENT) {
1189                 /*
1190                  *      flag that an RA was received after an RS was sent
1191                  *      out on this interface.
1192                  */
1193                 in6_dev->if_flags |= IF_RA_RCVD;
1194         }
1195
1196         /*
1197          * Remember the managed/otherconf flags from most recently
1198          * received RA message (RFC 2462) -- yoshfuji
1199          */
1200         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1201                                 IF_RA_OTHERCONF)) |
1202                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1203                                         IF_RA_MANAGED : 0) |
1204                                 (ra_msg->icmph.icmp6_addrconf_other ?
1205                                         IF_RA_OTHERCONF : 0);
1206
1207         if (!in6_dev->cnf.accept_ra_defrtr)
1208                 goto skip_defrtr;
1209
1210         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1211
1212 #ifdef CONFIG_IPV6_ROUTER_PREF
1213         pref = ra_msg->icmph.icmp6_router_pref;
1214         /* 10b is handled as if it were 00b (medium) */
1215         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1216             !in6_dev->cnf.accept_ra_rtr_pref)
1217                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1218 #endif
1219
1220         rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1221
1222         if (rt)
1223                 neigh = rt->rt6i_nexthop;
1224
1225         if (rt && lifetime == 0) {
1226                 neigh_clone(neigh);
1227                 ip6_del_rt(rt);
1228                 rt = NULL;
1229         }
1230
1231         if (rt == NULL && lifetime) {
1232                 ND_PRINTK3(KERN_DEBUG
1233                            "ICMPv6 RA: adding default router.\n");
1234
1235                 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1236                 if (rt == NULL) {
1237                         ND_PRINTK0(KERN_ERR
1238                                    "ICMPv6 RA: %s() failed to add default route.\n",
1239                                    __func__);
1240                         in6_dev_put(in6_dev);
1241                         return;
1242                 }
1243
1244                 neigh = rt->rt6i_nexthop;
1245                 if (neigh == NULL) {
1246                         ND_PRINTK0(KERN_ERR
1247                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1248                                    __func__);
1249                         dst_release(&rt->dst);
1250                         in6_dev_put(in6_dev);
1251                         return;
1252                 }
1253                 neigh->flags |= NTF_ROUTER;
1254         } else if (rt) {
1255                 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1256         }
1257
1258         if (rt)
1259                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1260
1261         if (ra_msg->icmph.icmp6_hop_limit) {
1262                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1263                 if (rt)
1264                         dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1265                                        ra_msg->icmph.icmp6_hop_limit);
1266         }
1267
1268 skip_defrtr:
1269
1270         /*
1271          *      Update Reachable Time and Retrans Timer
1272          */
1273
1274         if (in6_dev->nd_parms) {
1275                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1276
1277                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1278                         rtime = (rtime*HZ)/1000;
1279                         if (rtime < HZ/10)
1280                                 rtime = HZ/10;
1281                         in6_dev->nd_parms->retrans_time = rtime;
1282                         in6_dev->tstamp = jiffies;
1283                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1284                 }
1285
1286                 rtime = ntohl(ra_msg->reachable_time);
1287                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1288                         rtime = (rtime*HZ)/1000;
1289
1290                         if (rtime < HZ/10)
1291                                 rtime = HZ/10;
1292
1293                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1294                                 in6_dev->nd_parms->base_reachable_time = rtime;
1295                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1296                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1297                                 in6_dev->tstamp = jiffies;
1298                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1299                         }
1300                 }
1301         }
1302
1303 skip_linkparms:
1304
1305         /*
1306          *      Process options.
1307          */
1308
1309         if (!neigh)
1310                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1311                                        skb->dev, 1);
1312         if (neigh) {
1313                 u8 *lladdr = NULL;
1314                 if (ndopts.nd_opts_src_lladdr) {
1315                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1316                                                      skb->dev);
1317                         if (!lladdr) {
1318                                 ND_PRINTK2(KERN_WARNING
1319                                            "ICMPv6 RA: invalid link-layer address length\n");
1320                                 goto out;
1321                         }
1322                 }
1323                 neigh_update(neigh, lladdr, NUD_STALE,
1324                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1325                              NEIGH_UPDATE_F_OVERRIDE|
1326                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1327                              NEIGH_UPDATE_F_ISROUTER);
1328         }
1329
1330         if (!accept_ra(in6_dev))
1331                 goto out;
1332
1333 #ifdef CONFIG_IPV6_ROUTE_INFO
1334         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1335                 struct nd_opt_hdr *p;
1336                 for (p = ndopts.nd_opts_ri;
1337                      p;
1338                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1339                         struct route_info *ri = (struct route_info *)p;
1340 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1341                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1342                             ri->prefix_len == 0)
1343                                 continue;
1344 #endif
1345                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1346                                 continue;
1347                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1348                                       &ipv6_hdr(skb)->saddr);
1349                 }
1350         }
1351 #endif
1352
1353 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1354         /* skip link-specific ndopts from interior routers */
1355         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1356                 goto out;
1357 #endif
1358
1359         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1360                 struct nd_opt_hdr *p;
1361                 for (p = ndopts.nd_opts_pi;
1362                      p;
1363                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1364                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1365                 }
1366         }
1367
1368         if (ndopts.nd_opts_mtu) {
1369                 __be32 n;
1370                 u32 mtu;
1371
1372                 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1373                 mtu = ntohl(n);
1374
1375                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1376                         ND_PRINTK2(KERN_WARNING
1377                                    "ICMPv6 RA: invalid mtu: %d\n",
1378                                    mtu);
1379                 } else if (in6_dev->cnf.mtu6 != mtu) {
1380                         in6_dev->cnf.mtu6 = mtu;
1381
1382                         if (rt)
1383                                 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1384
1385                         rt6_mtu_change(skb->dev, mtu);
1386                 }
1387         }
1388
1389         if (ndopts.nd_useropts) {
1390                 struct nd_opt_hdr *p;
1391                 for (p = ndopts.nd_useropts;
1392                      p;
1393                      p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1394                         ndisc_ra_useropt(skb, p);
1395                 }
1396         }
1397
1398         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1399                 ND_PRINTK2(KERN_WARNING
1400                            "ICMPv6 RA: invalid RA options");
1401         }
1402 out:
1403         if (rt)
1404                 dst_release(&rt->dst);
1405         else if (neigh)
1406                 neigh_release(neigh);
1407         in6_dev_put(in6_dev);
1408 }
1409
1410 static void ndisc_redirect_rcv(struct sk_buff *skb)
1411 {
1412         struct inet6_dev *in6_dev;
1413         struct icmp6hdr *icmph;
1414         struct in6_addr *dest;
1415         struct in6_addr *target;        /* new first hop to destination */
1416         struct neighbour *neigh;
1417         int on_link = 0;
1418         struct ndisc_options ndopts;
1419         int optlen;
1420         u8 *lladdr = NULL;
1421
1422 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1423         switch (skb->ndisc_nodetype) {
1424         case NDISC_NODETYPE_HOST:
1425         case NDISC_NODETYPE_NODEFAULT:
1426                 ND_PRINTK2(KERN_WARNING
1427                            "ICMPv6 Redirect: from host or unauthorized router\n");
1428                 return;
1429         }
1430 #endif
1431
1432         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1433                 ND_PRINTK2(KERN_WARNING
1434                            "ICMPv6 Redirect: source address is not link-local.\n");
1435                 return;
1436         }
1437
1438         optlen = skb->tail - skb->transport_header;
1439         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1440
1441         if (optlen < 0) {
1442                 ND_PRINTK2(KERN_WARNING
1443                            "ICMPv6 Redirect: packet too short\n");
1444                 return;
1445         }
1446
1447         icmph = icmp6_hdr(skb);
1448         target = (struct in6_addr *) (icmph + 1);
1449         dest = target + 1;
1450
1451         if (ipv6_addr_is_multicast(dest)) {
1452                 ND_PRINTK2(KERN_WARNING
1453                            "ICMPv6 Redirect: destination address is multicast.\n");
1454                 return;
1455         }
1456
1457         if (ipv6_addr_equal(dest, target)) {
1458                 on_link = 1;
1459         } else if (ipv6_addr_type(target) !=
1460                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1461                 ND_PRINTK2(KERN_WARNING
1462                            "ICMPv6 Redirect: target address is not link-local unicast.\n");
1463                 return;
1464         }
1465
1466         in6_dev = in6_dev_get(skb->dev);
1467         if (!in6_dev)
1468                 return;
1469         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1470                 in6_dev_put(in6_dev);
1471                 return;
1472         }
1473
1474         /* RFC2461 8.1:
1475          *      The IP source address of the Redirect MUST be the same as the current
1476          *      first-hop router for the specified ICMP Destination Address.
1477          */
1478
1479         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1480                 ND_PRINTK2(KERN_WARNING
1481                            "ICMPv6 Redirect: invalid ND options\n");
1482                 in6_dev_put(in6_dev);
1483                 return;
1484         }
1485         if (ndopts.nd_opts_tgt_lladdr) {
1486                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1487                                              skb->dev);
1488                 if (!lladdr) {
1489                         ND_PRINTK2(KERN_WARNING
1490                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1491                         in6_dev_put(in6_dev);
1492                         return;
1493                 }
1494         }
1495
1496         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1497         if (neigh) {
1498                 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1499                              &ipv6_hdr(skb)->saddr, neigh, lladdr,
1500                              on_link);
1501                 neigh_release(neigh);
1502         }
1503         in6_dev_put(in6_dev);
1504 }
1505
1506 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1507                          const struct in6_addr *target)
1508 {
1509         struct net_device *dev = skb->dev;
1510         struct net *net = dev_net(dev);
1511         struct sock *sk = net->ipv6.ndisc_sk;
1512         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1513         struct sk_buff *buff;
1514         struct icmp6hdr *icmph;
1515         struct in6_addr saddr_buf;
1516         struct in6_addr *addrp;
1517         struct rt6_info *rt;
1518         struct dst_entry *dst;
1519         struct inet6_dev *idev;
1520         struct flowi6 fl6;
1521         u8 *opt;
1522         int rd_len;
1523         int err;
1524         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1525
1526         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1527                 ND_PRINTK2(KERN_WARNING
1528                            "ICMPv6 Redirect: no link-local address on %s\n",
1529                            dev->name);
1530                 return;
1531         }
1532
1533         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1534             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1535                 ND_PRINTK2(KERN_WARNING
1536                         "ICMPv6 Redirect: target address is not link-local unicast.\n");
1537                 return;
1538         }
1539
1540         icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1541                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1542
1543         dst = ip6_route_output(net, NULL, &fl6);
1544         if (dst == NULL)
1545                 return;
1546
1547         dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1548         if (IS_ERR(dst))
1549                 return;
1550
1551         rt = (struct rt6_info *) dst;
1552
1553         if (rt->rt6i_flags & RTF_GATEWAY) {
1554                 ND_PRINTK2(KERN_WARNING
1555                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1556                 goto release;
1557         }
1558         if (!rt->rt6i_peer)
1559                 rt6_bind_peer(rt, 1);
1560         if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
1561                 goto release;
1562
1563         if (dev->addr_len) {
1564                 read_lock_bh(&neigh->lock);
1565                 if (neigh->nud_state & NUD_VALID) {
1566                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1567                         read_unlock_bh(&neigh->lock);
1568                         ha = ha_buf;
1569                         len += ndisc_opt_addr_space(dev);
1570                 } else
1571                         read_unlock_bh(&neigh->lock);
1572         }
1573
1574         rd_len = min_t(unsigned int,
1575                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1576         rd_len &= ~0x7;
1577         len += rd_len;
1578
1579         buff = sock_alloc_send_skb(sk,
1580                                    (MAX_HEADER + sizeof(struct ipv6hdr) +
1581                                     len + LL_ALLOCATED_SPACE(dev)),
1582                                    1, &err);
1583         if (buff == NULL) {
1584                 ND_PRINTK0(KERN_ERR
1585                            "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1586                            __func__, err);
1587                 goto release;
1588         }
1589
1590         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1591         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1592                    IPPROTO_ICMPV6, len);
1593
1594         skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1595         skb_put(buff, len);
1596         icmph = icmp6_hdr(buff);
1597
1598         memset(icmph, 0, sizeof(struct icmp6hdr));
1599         icmph->icmp6_type = NDISC_REDIRECT;
1600
1601         /*
1602          *      copy target and destination addresses
1603          */
1604
1605         addrp = (struct in6_addr *)(icmph + 1);
1606         ipv6_addr_copy(addrp, target);
1607         addrp++;
1608         ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1609
1610         opt = (u8*) (addrp + 1);
1611
1612         /*
1613          *      include target_address option
1614          */
1615
1616         if (ha)
1617                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1618                                              dev->addr_len, dev->type);
1619
1620         /*
1621          *      build redirect option and copy skb over to the new packet.
1622          */
1623
1624         memset(opt, 0, 8);
1625         *(opt++) = ND_OPT_REDIRECT_HDR;
1626         *(opt++) = (rd_len >> 3);
1627         opt += 6;
1628
1629         memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1630
1631         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1632                                              len, IPPROTO_ICMPV6,
1633                                              csum_partial(icmph, len, 0));
1634
1635         skb_dst_set(buff, dst);
1636         idev = in6_dev_get(dst->dev);
1637         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1638         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1639                       dst_output);
1640         if (!err) {
1641                 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1642                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1643         }
1644
1645         if (likely(idev != NULL))
1646                 in6_dev_put(idev);
1647         return;
1648
1649 release:
1650         dst_release(dst);
1651 }
1652
1653 static void pndisc_redo(struct sk_buff *skb)
1654 {
1655         ndisc_recv_ns(skb);
1656         kfree_skb(skb);
1657 }
1658
1659 int ndisc_rcv(struct sk_buff *skb)
1660 {
1661         struct nd_msg *msg;
1662
1663         if (!pskb_may_pull(skb, skb->len))
1664                 return 0;
1665
1666         msg = (struct nd_msg *)skb_transport_header(skb);
1667
1668         __skb_push(skb, skb->data - skb_transport_header(skb));
1669
1670         if (ipv6_hdr(skb)->hop_limit != 255) {
1671                 ND_PRINTK2(KERN_WARNING
1672                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1673                            ipv6_hdr(skb)->hop_limit);
1674                 return 0;
1675         }
1676
1677         if (msg->icmph.icmp6_code != 0) {
1678                 ND_PRINTK2(KERN_WARNING
1679                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1680                            msg->icmph.icmp6_code);
1681                 return 0;
1682         }
1683
1684         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1685
1686         switch (msg->icmph.icmp6_type) {
1687         case NDISC_NEIGHBOUR_SOLICITATION:
1688                 ndisc_recv_ns(skb);
1689                 break;
1690
1691         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1692                 ndisc_recv_na(skb);
1693                 break;
1694
1695         case NDISC_ROUTER_SOLICITATION:
1696                 ndisc_recv_rs(skb);
1697                 break;
1698
1699         case NDISC_ROUTER_ADVERTISEMENT:
1700                 ndisc_router_discovery(skb);
1701                 break;
1702
1703         case NDISC_REDIRECT:
1704                 ndisc_redirect_rcv(skb);
1705                 break;
1706         }
1707
1708         return 0;
1709 }
1710
1711 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1712 {
1713         struct net_device *dev = ptr;
1714         struct net *net = dev_net(dev);
1715
1716         switch (event) {
1717         case NETDEV_CHANGEADDR:
1718                 neigh_changeaddr(&nd_tbl, dev);
1719                 fib6_run_gc(~0UL, net);
1720                 break;
1721         case NETDEV_DOWN:
1722                 neigh_ifdown(&nd_tbl, dev);
1723                 fib6_run_gc(~0UL, net);
1724                 break;
1725         default:
1726                 break;
1727         }
1728
1729         return NOTIFY_DONE;
1730 }
1731
1732 static struct notifier_block ndisc_netdev_notifier = {
1733         .notifier_call = ndisc_netdev_event,
1734 };
1735
1736 #ifdef CONFIG_SYSCTL
1737 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1738                                          const char *func, const char *dev_name)
1739 {
1740         static char warncomm[TASK_COMM_LEN];
1741         static int warned;
1742         if (strcmp(warncomm, current->comm) && warned < 5) {
1743                 strcpy(warncomm, current->comm);
1744                 printk(KERN_WARNING
1745                         "process `%s' is using deprecated sysctl (%s) "
1746                         "net.ipv6.neigh.%s.%s; "
1747                         "Use net.ipv6.neigh.%s.%s_ms "
1748                         "instead.\n",
1749                         warncomm, func,
1750                         dev_name, ctl->procname,
1751                         dev_name, ctl->procname);
1752                 warned++;
1753         }
1754 }
1755
1756 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1757 {
1758         struct net_device *dev = ctl->extra1;
1759         struct inet6_dev *idev;
1760         int ret;
1761
1762         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1763             (strcmp(ctl->procname, "base_reachable_time") == 0))
1764                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1765
1766         if (strcmp(ctl->procname, "retrans_time") == 0)
1767                 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1768
1769         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1770                 ret = proc_dointvec_jiffies(ctl, write,
1771                                             buffer, lenp, ppos);
1772
1773         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1774                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1775                 ret = proc_dointvec_ms_jiffies(ctl, write,
1776                                                buffer, lenp, ppos);
1777         else
1778                 ret = -1;
1779
1780         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1781                 if (ctl->data == &idev->nd_parms->base_reachable_time)
1782                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1783                 idev->tstamp = jiffies;
1784                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1785                 in6_dev_put(idev);
1786         }
1787         return ret;
1788 }
1789
1790
1791 #endif
1792
1793 static int __net_init ndisc_net_init(struct net *net)
1794 {
1795         struct ipv6_pinfo *np;
1796         struct sock *sk;
1797         int err;
1798
1799         err = inet_ctl_sock_create(&sk, PF_INET6,
1800                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1801         if (err < 0) {
1802                 ND_PRINTK0(KERN_ERR
1803                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1804                            err);
1805                 return err;
1806         }
1807
1808         net->ipv6.ndisc_sk = sk;
1809
1810         np = inet6_sk(sk);
1811         np->hop_limit = 255;
1812         /* Do not loopback ndisc messages */
1813         np->mc_loop = 0;
1814
1815         return 0;
1816 }
1817
1818 static void __net_exit ndisc_net_exit(struct net *net)
1819 {
1820         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1821 }
1822
1823 static struct pernet_operations ndisc_net_ops = {
1824         .init = ndisc_net_init,
1825         .exit = ndisc_net_exit,
1826 };
1827
1828 int __init ndisc_init(void)
1829 {
1830         int err;
1831
1832         err = register_pernet_subsys(&ndisc_net_ops);
1833         if (err)
1834                 return err;
1835         /*
1836          * Initialize the neighbour table
1837          */
1838         neigh_table_init(&nd_tbl);
1839
1840 #ifdef CONFIG_SYSCTL
1841         err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6",
1842                                     &ndisc_ifinfo_sysctl_change);
1843         if (err)
1844                 goto out_unregister_pernet;
1845 #endif
1846         err = register_netdevice_notifier(&ndisc_netdev_notifier);
1847         if (err)
1848                 goto out_unregister_sysctl;
1849 out:
1850         return err;
1851
1852 out_unregister_sysctl:
1853 #ifdef CONFIG_SYSCTL
1854         neigh_sysctl_unregister(&nd_tbl.parms);
1855 out_unregister_pernet:
1856 #endif
1857         unregister_pernet_subsys(&ndisc_net_ops);
1858         goto out;
1859 }
1860
1861 void ndisc_cleanup(void)
1862 {
1863         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1864 #ifdef CONFIG_SYSCTL
1865         neigh_sysctl_unregister(&nd_tbl.parms);
1866 #endif
1867         neigh_table_clear(&nd_tbl);
1868         unregister_pernet_subsys(&ndisc_net_ops);
1869 }