Revert "sit: stateless autoconf for isatap"
[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 #ifdef CONFIG_SYSCTL
63 #include <linux/sysctl.h>
64 #endif
65
66 #include <linux/if_addr.h>
67 #include <linux/if_arp.h>
68 #include <linux/ipv6.h>
69 #include <linux/icmpv6.h>
70 #include <linux/jhash.h>
71
72 #include <net/sock.h>
73 #include <net/snmp.h>
74
75 #include <net/ipv6.h>
76 #include <net/protocol.h>
77 #include <net/ndisc.h>
78 #include <net/ip6_route.h>
79 #include <net/addrconf.h>
80 #include <net/icmp.h>
81
82 #include <net/netlink.h>
83 #include <linux/rtnetlink.h>
84
85 #include <net/flow.h>
86 #include <net/ip6_checksum.h>
87 #include <net/inet_common.h>
88 #include <linux/proc_fs.h>
89
90 #include <linux/netfilter.h>
91 #include <linux/netfilter_ipv6.h>
92
93 static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
94 static int ndisc_constructor(struct neighbour *neigh);
95 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
96 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
97 static int pndisc_constructor(struct pneigh_entry *n);
98 static void pndisc_destructor(struct pneigh_entry *n);
99 static void pndisc_redo(struct sk_buff *skb);
100
101 static const struct neigh_ops ndisc_generic_ops = {
102         .family =               AF_INET6,
103         .solicit =              ndisc_solicit,
104         .error_report =         ndisc_error_report,
105         .output =               neigh_resolve_output,
106         .connected_output =     neigh_connected_output,
107         .hh_output =            dev_queue_xmit,
108         .queue_xmit =           dev_queue_xmit,
109 };
110
111 static const struct neigh_ops ndisc_hh_ops = {
112         .family =               AF_INET6,
113         .solicit =              ndisc_solicit,
114         .error_report =         ndisc_error_report,
115         .output =               neigh_resolve_output,
116         .connected_output =     neigh_resolve_output,
117         .hh_output =            dev_queue_xmit,
118         .queue_xmit =           dev_queue_xmit,
119 };
120
121
122 static const struct neigh_ops ndisc_direct_ops = {
123         .family =               AF_INET6,
124         .output =               dev_queue_xmit,
125         .connected_output =     dev_queue_xmit,
126         .hh_output =            dev_queue_xmit,
127         .queue_xmit =           dev_queue_xmit,
128 };
129
130 struct neigh_table nd_tbl = {
131         .family =       AF_INET6,
132         .entry_size =   sizeof(struct neighbour) + sizeof(struct in6_addr),
133         .key_len =      sizeof(struct in6_addr),
134         .hash =         ndisc_hash,
135         .constructor =  ndisc_constructor,
136         .pconstructor = pndisc_constructor,
137         .pdestructor =  pndisc_destructor,
138         .proxy_redo =   pndisc_redo,
139         .id =           "ndisc_cache",
140         .parms = {
141                 .tbl =                  &nd_tbl,
142                 .base_reachable_time =  30 * HZ,
143                 .retrans_time =  1 * HZ,
144                 .gc_staletime = 60 * HZ,
145                 .reachable_time =               30 * HZ,
146                 .delay_probe_time =      5 * HZ,
147                 .queue_len =             3,
148                 .ucast_probes =  3,
149                 .mcast_probes =  3,
150                 .anycast_delay =         1 * HZ,
151                 .proxy_delay =          (8 * HZ) / 10,
152                 .proxy_qlen =           64,
153         },
154         .gc_interval =    30 * HZ,
155         .gc_thresh1 =    128,
156         .gc_thresh2 =    512,
157         .gc_thresh3 =   1024,
158 };
159
160 /* ND options */
161 struct ndisc_options {
162         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
163 #ifdef CONFIG_IPV6_ROUTE_INFO
164         struct nd_opt_hdr *nd_opts_ri;
165         struct nd_opt_hdr *nd_opts_ri_end;
166 #endif
167         struct nd_opt_hdr *nd_useropts;
168         struct nd_opt_hdr *nd_useropts_end;
169 };
170
171 #define nd_opts_src_lladdr      nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
172 #define nd_opts_tgt_lladdr      nd_opt_array[ND_OPT_TARGET_LL_ADDR]
173 #define nd_opts_pi              nd_opt_array[ND_OPT_PREFIX_INFO]
174 #define nd_opts_pi_end          nd_opt_array[__ND_OPT_PREFIX_INFO_END]
175 #define nd_opts_rh              nd_opt_array[ND_OPT_REDIRECT_HDR]
176 #define nd_opts_mtu             nd_opt_array[ND_OPT_MTU]
177
178 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
179
180 /*
181  * Return the padding between the option length and the start of the
182  * link addr.  Currently only IP-over-InfiniBand needs this, although
183  * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
184  * also need a pad of 2.
185  */
186 static int ndisc_addr_option_pad(unsigned short type)
187 {
188         switch (type) {
189         case ARPHRD_INFINIBAND: return 2;
190         default:                return 0;
191         }
192 }
193
194 static inline int ndisc_opt_addr_space(struct net_device *dev)
195 {
196         return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
197 }
198
199 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
200                                   unsigned short addr_type)
201 {
202         int space = NDISC_OPT_SPACE(data_len);
203         int pad   = ndisc_addr_option_pad(addr_type);
204
205         opt[0] = type;
206         opt[1] = space>>3;
207
208         memset(opt + 2, 0, pad);
209         opt   += pad;
210         space -= pad;
211
212         memcpy(opt+2, data, data_len);
213         data_len += 2;
214         opt += data_len;
215         if ((space -= data_len) > 0)
216                 memset(opt, 0, space);
217         return opt + space;
218 }
219
220 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
221                                             struct nd_opt_hdr *end)
222 {
223         int type;
224         if (!cur || !end || cur >= end)
225                 return NULL;
226         type = cur->nd_opt_type;
227         do {
228                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
229         } while(cur < end && cur->nd_opt_type != type);
230         return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
231 }
232
233 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
234 {
235         return (opt->nd_opt_type == ND_OPT_RDNSS);
236 }
237
238 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
239                                              struct nd_opt_hdr *end)
240 {
241         if (!cur || !end || cur >= end)
242                 return NULL;
243         do {
244                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
245         } while(cur < end && !ndisc_is_useropt(cur));
246         return (cur <= end && ndisc_is_useropt(cur) ? cur : NULL);
247 }
248
249 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
250                                                  struct ndisc_options *ndopts)
251 {
252         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
253
254         if (!nd_opt || opt_len < 0 || !ndopts)
255                 return NULL;
256         memset(ndopts, 0, sizeof(*ndopts));
257         while (opt_len) {
258                 int l;
259                 if (opt_len < sizeof(struct nd_opt_hdr))
260                         return NULL;
261                 l = nd_opt->nd_opt_len << 3;
262                 if (opt_len < l || l == 0)
263                         return NULL;
264                 switch (nd_opt->nd_opt_type) {
265                 case ND_OPT_SOURCE_LL_ADDR:
266                 case ND_OPT_TARGET_LL_ADDR:
267                 case ND_OPT_MTU:
268                 case ND_OPT_REDIRECT_HDR:
269                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
270                                 ND_PRINTK2(KERN_WARNING
271                                            "%s(): duplicated ND6 option found: type=%d\n",
272                                            __func__,
273                                            nd_opt->nd_opt_type);
274                         } else {
275                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
276                         }
277                         break;
278                 case ND_OPT_PREFIX_INFO:
279                         ndopts->nd_opts_pi_end = nd_opt;
280                         if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
281                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
282                         break;
283 #ifdef CONFIG_IPV6_ROUTE_INFO
284                 case ND_OPT_ROUTE_INFO:
285                         ndopts->nd_opts_ri_end = nd_opt;
286                         if (!ndopts->nd_opts_ri)
287                                 ndopts->nd_opts_ri = nd_opt;
288                         break;
289 #endif
290                 default:
291                         if (ndisc_is_useropt(nd_opt)) {
292                                 ndopts->nd_useropts_end = nd_opt;
293                                 if (!ndopts->nd_useropts)
294                                         ndopts->nd_useropts = nd_opt;
295                         } else {
296                                 /*
297                                  * Unknown options must be silently ignored,
298                                  * to accommodate future extension to the
299                                  * protocol.
300                                  */
301                                 ND_PRINTK2(KERN_NOTICE
302                                            "%s(): ignored unsupported option; type=%d, len=%d\n",
303                                            __func__,
304                                            nd_opt->nd_opt_type, nd_opt->nd_opt_len);
305                         }
306                 }
307                 opt_len -= l;
308                 nd_opt = ((void *)nd_opt) + l;
309         }
310         return ndopts;
311 }
312
313 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
314                                       struct net_device *dev)
315 {
316         u8 *lladdr = (u8 *)(p + 1);
317         int lladdrlen = p->nd_opt_len << 3;
318         int prepad = ndisc_addr_option_pad(dev->type);
319         if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
320                 return NULL;
321         return (lladdr + prepad);
322 }
323
324 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
325 {
326         switch (dev->type) {
327         case ARPHRD_ETHER:
328         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
329         case ARPHRD_FDDI:
330                 ipv6_eth_mc_map(addr, buf);
331                 return 0;
332         case ARPHRD_IEEE802_TR:
333                 ipv6_tr_mc_map(addr,buf);
334                 return 0;
335         case ARPHRD_ARCNET:
336                 ipv6_arcnet_mc_map(addr, buf);
337                 return 0;
338         case ARPHRD_INFINIBAND:
339                 ipv6_ib_mc_map(addr, dev->broadcast, buf);
340                 return 0;
341         default:
342                 if (dir) {
343                         memcpy(buf, dev->broadcast, dev->addr_len);
344                         return 0;
345                 }
346         }
347         return -EINVAL;
348 }
349
350 EXPORT_SYMBOL(ndisc_mc_map);
351
352 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
353 {
354         const u32 *p32 = pkey;
355         u32 addr_hash, i;
356
357         addr_hash = 0;
358         for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
359                 addr_hash ^= *p32++;
360
361         return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
362 }
363
364 static int ndisc_constructor(struct neighbour *neigh)
365 {
366         struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
367         struct net_device *dev = neigh->dev;
368         struct inet6_dev *in6_dev;
369         struct neigh_parms *parms;
370         int is_multicast = ipv6_addr_is_multicast(addr);
371
372         rcu_read_lock();
373         in6_dev = in6_dev_get(dev);
374         if (in6_dev == NULL) {
375                 rcu_read_unlock();
376                 return -EINVAL;
377         }
378
379         parms = in6_dev->nd_parms;
380         __neigh_parms_put(neigh->parms);
381         neigh->parms = neigh_parms_clone(parms);
382         rcu_read_unlock();
383
384         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
385         if (!dev->header_ops) {
386                 neigh->nud_state = NUD_NOARP;
387                 neigh->ops = &ndisc_direct_ops;
388                 neigh->output = neigh->ops->queue_xmit;
389         } else {
390                 if (is_multicast) {
391                         neigh->nud_state = NUD_NOARP;
392                         ndisc_mc_map(addr, neigh->ha, dev, 1);
393                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
394                         neigh->nud_state = NUD_NOARP;
395                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
396                         if (dev->flags&IFF_LOOPBACK)
397                                 neigh->type = RTN_LOCAL;
398                 } else if (dev->flags&IFF_POINTOPOINT) {
399                         neigh->nud_state = NUD_NOARP;
400                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
401                 }
402                 if (dev->header_ops->cache)
403                         neigh->ops = &ndisc_hh_ops;
404                 else
405                         neigh->ops = &ndisc_generic_ops;
406                 if (neigh->nud_state&NUD_VALID)
407                         neigh->output = neigh->ops->connected_output;
408                 else
409                         neigh->output = neigh->ops->output;
410         }
411         in6_dev_put(in6_dev);
412         return 0;
413 }
414
415 static int pndisc_constructor(struct pneigh_entry *n)
416 {
417         struct in6_addr *addr = (struct in6_addr*)&n->key;
418         struct in6_addr maddr;
419         struct net_device *dev = n->dev;
420
421         if (dev == NULL || __in6_dev_get(dev) == NULL)
422                 return -EINVAL;
423         addrconf_addr_solict_mult(addr, &maddr);
424         ipv6_dev_mc_inc(dev, &maddr);
425         return 0;
426 }
427
428 static void pndisc_destructor(struct pneigh_entry *n)
429 {
430         struct in6_addr *addr = (struct in6_addr*)&n->key;
431         struct in6_addr maddr;
432         struct net_device *dev = n->dev;
433
434         if (dev == NULL || __in6_dev_get(dev) == NULL)
435                 return;
436         addrconf_addr_solict_mult(addr, &maddr);
437         ipv6_dev_mc_dec(dev, &maddr);
438 }
439
440 struct sk_buff *ndisc_build_skb(struct net_device *dev,
441                                 const struct in6_addr *daddr,
442                                 const struct in6_addr *saddr,
443                                 struct icmp6hdr *icmp6h,
444                                 const struct in6_addr *target,
445                                 int llinfo)
446 {
447         struct net *net = dev_net(dev);
448         struct sock *sk = net->ipv6.ndisc_sk;
449         struct sk_buff *skb;
450         struct icmp6hdr *hdr;
451         int len;
452         int err;
453         u8 *opt;
454
455         if (!dev->addr_len)
456                 llinfo = 0;
457
458         len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
459         if (llinfo)
460                 len += ndisc_opt_addr_space(dev);
461
462         skb = sock_alloc_send_skb(sk,
463                                   (MAX_HEADER + sizeof(struct ipv6hdr) +
464                                    len + LL_ALLOCATED_SPACE(dev)),
465                                   1, &err);
466         if (!skb) {
467                 ND_PRINTK0(KERN_ERR
468                            "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
469                            __func__, err);
470                 return NULL;
471         }
472
473         skb_reserve(skb, LL_RESERVED_SPACE(dev));
474         ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
475
476         skb->transport_header = skb->tail;
477         skb_put(skb, len);
478
479         hdr = (struct icmp6hdr *)skb_transport_header(skb);
480         memcpy(hdr, icmp6h, sizeof(*hdr));
481
482         opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
483         if (target) {
484                 ipv6_addr_copy((struct in6_addr *)opt, target);
485                 opt += sizeof(*target);
486         }
487
488         if (llinfo)
489                 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
490                                        dev->addr_len, dev->type);
491
492         hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
493                                            IPPROTO_ICMPV6,
494                                            csum_partial(hdr,
495                                                         len, 0));
496
497         return skb;
498 }
499
500 EXPORT_SYMBOL(ndisc_build_skb);
501
502 void ndisc_send_skb(struct sk_buff *skb,
503                     struct net_device *dev,
504                     struct neighbour *neigh,
505                     const struct in6_addr *daddr,
506                     const struct in6_addr *saddr,
507                     struct icmp6hdr *icmp6h)
508 {
509         struct flowi fl;
510         struct dst_entry *dst;
511         struct net *net = dev_net(dev);
512         struct sock *sk = net->ipv6.ndisc_sk;
513         struct inet6_dev *idev;
514         int err;
515         u8 type;
516
517         type = icmp6h->icmp6_type;
518
519         icmpv6_flow_init(sk, &fl, type, saddr, daddr, dev->ifindex);
520
521         dst = icmp6_dst_alloc(dev, neigh, daddr);
522         if (!dst) {
523                 kfree_skb(skb);
524                 return;
525         }
526
527         err = xfrm_lookup(net, &dst, &fl, NULL, 0);
528         if (err < 0) {
529                 kfree_skb(skb);
530                 return;
531         }
532
533         skb_dst_set(skb, dst);
534
535         idev = in6_dev_get(dst->dev);
536         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
537
538         err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
539                       dst_output);
540         if (!err) {
541                 ICMP6MSGOUT_INC_STATS(net, idev, type);
542                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
543         }
544
545         if (likely(idev != NULL))
546                 in6_dev_put(idev);
547 }
548
549 EXPORT_SYMBOL(ndisc_send_skb);
550
551 /*
552  *      Send a Neighbour Discover packet
553  */
554 static void __ndisc_send(struct net_device *dev,
555                          struct neighbour *neigh,
556                          const struct in6_addr *daddr,
557                          const struct in6_addr *saddr,
558                          struct icmp6hdr *icmp6h, const struct in6_addr *target,
559                          int llinfo)
560 {
561         struct sk_buff *skb;
562
563         skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
564         if (!skb)
565                 return;
566
567         ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
568 }
569
570 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
571                           const struct in6_addr *daddr,
572                           const struct in6_addr *solicited_addr,
573                           int router, int solicited, int override, int inc_opt)
574 {
575         struct in6_addr tmpaddr;
576         struct inet6_ifaddr *ifp;
577         const struct in6_addr *src_addr;
578         struct icmp6hdr icmp6h = {
579                 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
580         };
581
582         /* for anycast or proxy, solicited_addr != src_addr */
583         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
584         if (ifp) {
585                 src_addr = solicited_addr;
586                 if (ifp->flags & IFA_F_OPTIMISTIC)
587                         override = 0;
588                 in6_ifa_put(ifp);
589         } else {
590                 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
591                                        inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
592                                        &tmpaddr))
593                         return;
594                 src_addr = &tmpaddr;
595         }
596
597         icmp6h.icmp6_router = router;
598         icmp6h.icmp6_solicited = solicited;
599         icmp6h.icmp6_override = override;
600
601         __ndisc_send(dev, neigh, daddr, src_addr,
602                      &icmp6h, solicited_addr,
603                      inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
604 }
605
606 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
607                    const struct in6_addr *solicit,
608                    const struct in6_addr *daddr, const struct in6_addr *saddr)
609 {
610         struct in6_addr addr_buf;
611         struct icmp6hdr icmp6h = {
612                 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
613         };
614
615         if (saddr == NULL) {
616                 if (ipv6_get_lladdr(dev, &addr_buf,
617                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
618                         return;
619                 saddr = &addr_buf;
620         }
621
622         __ndisc_send(dev, neigh, daddr, saddr,
623                      &icmp6h, solicit,
624                      !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
625 }
626
627 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
628                    const struct in6_addr *daddr)
629 {
630         struct icmp6hdr icmp6h = {
631                 .icmp6_type = NDISC_ROUTER_SOLICITATION,
632         };
633         int send_sllao = dev->addr_len;
634
635 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
636         /*
637          * According to section 2.2 of RFC 4429, we must not
638          * send router solicitations with a sllao from
639          * optimistic addresses, but we may send the solicitation
640          * if we don't include the sllao.  So here we check
641          * if our address is optimistic, and if so, we
642          * suppress the inclusion of the sllao.
643          */
644         if (send_sllao) {
645                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
646                                                            dev, 1);
647                 if (ifp) {
648                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
649                                 send_sllao = 0;
650                         }
651                         in6_ifa_put(ifp);
652                 } else {
653                         send_sllao = 0;
654                 }
655         }
656 #endif
657         __ndisc_send(dev, NULL, daddr, saddr,
658                      &icmp6h, NULL,
659                      send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
660 }
661
662
663 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
664 {
665         /*
666          *      "The sender MUST return an ICMP
667          *       destination unreachable"
668          */
669         dst_link_failure(skb);
670         kfree_skb(skb);
671 }
672
673 /* Called with locked neigh: either read or both */
674
675 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
676 {
677         struct in6_addr *saddr = NULL;
678         struct in6_addr mcaddr;
679         struct net_device *dev = neigh->dev;
680         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
681         int probes = atomic_read(&neigh->probes);
682
683         if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
684                 saddr = &ipv6_hdr(skb)->saddr;
685
686         if ((probes -= neigh->parms->ucast_probes) < 0) {
687                 if (!(neigh->nud_state & NUD_VALID)) {
688                         ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
689                                    __func__, target);
690                 }
691                 ndisc_send_ns(dev, neigh, target, target, saddr);
692         } else if ((probes -= neigh->parms->app_probes) < 0) {
693 #ifdef CONFIG_ARPD
694                 neigh_app_ns(neigh);
695 #endif
696         } else {
697                 addrconf_addr_solict_mult(target, &mcaddr);
698                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
699         }
700 }
701
702 static int pndisc_is_router(const void *pkey,
703                             struct net_device *dev)
704 {
705         struct pneigh_entry *n;
706         int ret = -1;
707
708         read_lock_bh(&nd_tbl.lock);
709         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
710         if (n)
711                 ret = !!(n->flags & NTF_ROUTER);
712         read_unlock_bh(&nd_tbl.lock);
713
714         return ret;
715 }
716
717 static void ndisc_recv_ns(struct sk_buff *skb)
718 {
719         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
720         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
721         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
722         u8 *lladdr = NULL;
723         u32 ndoptlen = skb->tail - (skb->transport_header +
724                                     offsetof(struct nd_msg, opt));
725         struct ndisc_options ndopts;
726         struct net_device *dev = skb->dev;
727         struct inet6_ifaddr *ifp;
728         struct inet6_dev *idev = NULL;
729         struct neighbour *neigh;
730         int dad = ipv6_addr_any(saddr);
731         int inc;
732         int is_router = -1;
733
734         if (ipv6_addr_is_multicast(&msg->target)) {
735                 ND_PRINTK2(KERN_WARNING
736                            "ICMPv6 NS: multicast target address");
737                 return;
738         }
739
740         /*
741          * RFC2461 7.1.1:
742          * DAD has to be destined for solicited node multicast address.
743          */
744         if (dad &&
745             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
746               daddr->s6_addr32[1] == htonl(0x00000000) &&
747               daddr->s6_addr32[2] == htonl(0x00000001) &&
748               daddr->s6_addr [12] == 0xff )) {
749                 ND_PRINTK2(KERN_WARNING
750                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
751                 return;
752         }
753
754         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
755                 ND_PRINTK2(KERN_WARNING
756                            "ICMPv6 NS: invalid ND options\n");
757                 return;
758         }
759
760         if (ndopts.nd_opts_src_lladdr) {
761                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
762                 if (!lladdr) {
763                         ND_PRINTK2(KERN_WARNING
764                                    "ICMPv6 NS: invalid link-layer address length\n");
765                         return;
766                 }
767
768                 /* RFC2461 7.1.1:
769                  *      If the IP source address is the unspecified address,
770                  *      there MUST NOT be source link-layer address option
771                  *      in the message.
772                  */
773                 if (dad) {
774                         ND_PRINTK2(KERN_WARNING
775                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
776                         return;
777                 }
778         }
779
780         inc = ipv6_addr_is_multicast(daddr);
781
782         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
783         if (ifp) {
784
785                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
786                         if (dad) {
787                                 if (dev->type == ARPHRD_IEEE802_TR) {
788                                         const unsigned char *sadr;
789                                         sadr = skb_mac_header(skb);
790                                         if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
791                                             sadr[9] == dev->dev_addr[1] &&
792                                             sadr[10] == dev->dev_addr[2] &&
793                                             sadr[11] == dev->dev_addr[3] &&
794                                             sadr[12] == dev->dev_addr[4] &&
795                                             sadr[13] == dev->dev_addr[5]) {
796                                                 /* looped-back to us */
797                                                 goto out;
798                                         }
799                                 }
800
801                                 /*
802                                  * We are colliding with another node
803                                  * who is doing DAD
804                                  * so fail our DAD process
805                                  */
806                                 addrconf_dad_failure(ifp);
807                                 return;
808                         } else {
809                                 /*
810                                  * This is not a dad solicitation.
811                                  * If we are an optimistic node,
812                                  * we should respond.
813                                  * Otherwise, we should ignore it.
814                                  */
815                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
816                                         goto out;
817                         }
818                 }
819
820                 idev = ifp->idev;
821         } else {
822                 struct net *net = dev_net(dev);
823
824                 idev = in6_dev_get(dev);
825                 if (!idev) {
826                         /* XXX: count this drop? */
827                         return;
828                 }
829
830                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
831                     (idev->cnf.forwarding &&
832                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
833                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
834                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
835                             skb->pkt_type != PACKET_HOST &&
836                             inc != 0 &&
837                             idev->nd_parms->proxy_delay != 0) {
838                                 /*
839                                  * for anycast or proxy,
840                                  * sender should delay its response
841                                  * by a random time between 0 and
842                                  * MAX_ANYCAST_DELAY_TIME seconds.
843                                  * (RFC2461) -- yoshfuji
844                                  */
845                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
846                                 if (n)
847                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
848                                 goto out;
849                         }
850                 } else
851                         goto out;
852         }
853
854         if (is_router < 0)
855                 is_router = !!idev->cnf.forwarding;
856
857         if (dad) {
858                 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
859                               is_router, 0, (ifp != NULL), 1);
860                 goto out;
861         }
862
863         if (inc)
864                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
865         else
866                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
867
868         /*
869          *      update / create cache entry
870          *      for the source address
871          */
872         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
873                                !inc || lladdr || !dev->addr_len);
874         if (neigh)
875                 neigh_update(neigh, lladdr, NUD_STALE,
876                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
877                              NEIGH_UPDATE_F_OVERRIDE);
878         if (neigh || !dev->header_ops) {
879                 ndisc_send_na(dev, neigh, saddr, &msg->target,
880                               is_router,
881                               1, (ifp != NULL && inc), inc);
882                 if (neigh)
883                         neigh_release(neigh);
884         }
885
886 out:
887         if (ifp)
888                 in6_ifa_put(ifp);
889         else
890                 in6_dev_put(idev);
891
892         return;
893 }
894
895 static void ndisc_recv_na(struct sk_buff *skb)
896 {
897         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
898         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
899         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
900         u8 *lladdr = NULL;
901         u32 ndoptlen = skb->tail - (skb->transport_header +
902                                     offsetof(struct nd_msg, opt));
903         struct ndisc_options ndopts;
904         struct net_device *dev = skb->dev;
905         struct inet6_ifaddr *ifp;
906         struct neighbour *neigh;
907
908         if (skb->len < sizeof(struct nd_msg)) {
909                 ND_PRINTK2(KERN_WARNING
910                            "ICMPv6 NA: packet too short\n");
911                 return;
912         }
913
914         if (ipv6_addr_is_multicast(&msg->target)) {
915                 ND_PRINTK2(KERN_WARNING
916                            "ICMPv6 NA: target address is multicast.\n");
917                 return;
918         }
919
920         if (ipv6_addr_is_multicast(daddr) &&
921             msg->icmph.icmp6_solicited) {
922                 ND_PRINTK2(KERN_WARNING
923                            "ICMPv6 NA: solicited NA is multicasted.\n");
924                 return;
925         }
926
927         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
928                 ND_PRINTK2(KERN_WARNING
929                            "ICMPv6 NS: invalid ND option\n");
930                 return;
931         }
932         if (ndopts.nd_opts_tgt_lladdr) {
933                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
934                 if (!lladdr) {
935                         ND_PRINTK2(KERN_WARNING
936                                    "ICMPv6 NA: invalid link-layer address length\n");
937                         return;
938                 }
939         }
940         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
941         if (ifp) {
942                 if (ifp->flags & IFA_F_TENTATIVE) {
943                         addrconf_dad_failure(ifp);
944                         return;
945                 }
946                 /* What should we make now? The advertisement
947                    is invalid, but ndisc specs say nothing
948                    about it. It could be misconfiguration, or
949                    an smart proxy agent tries to help us :-)
950
951                    We should not print the error if NA has been
952                    received from loopback - it is just our own
953                    unsolicited advertisement.
954                  */
955                 if (skb->pkt_type != PACKET_LOOPBACK)
956                         ND_PRINTK1(KERN_WARNING
957                            "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
958                            &ifp->addr, ifp->idev->dev->name);
959                 in6_ifa_put(ifp);
960                 return;
961         }
962         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
963
964         if (neigh) {
965                 u8 old_flags = neigh->flags;
966                 struct net *net = dev_net(dev);
967
968                 if (neigh->nud_state & NUD_FAILED)
969                         goto out;
970
971                 /*
972                  * Don't update the neighbor cache entry on a proxy NA from
973                  * ourselves because either the proxied node is off link or it
974                  * has already sent a NA to us.
975                  */
976                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
977                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
978                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
979                         /* XXX: idev->cnf.prixy_ndp */
980                         goto out;
981                 }
982
983                 neigh_update(neigh, lladdr,
984                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
985                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
986                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
987                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
988                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
989
990                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
991                         /*
992                          * Change: router to host
993                          */
994                         struct rt6_info *rt;
995                         rt = rt6_get_dflt_router(saddr, dev);
996                         if (rt)
997                                 ip6_del_rt(rt);
998                 }
999
1000 out:
1001                 neigh_release(neigh);
1002         }
1003 }
1004
1005 static void ndisc_recv_rs(struct sk_buff *skb)
1006 {
1007         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1008         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1009         struct neighbour *neigh;
1010         struct inet6_dev *idev;
1011         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1012         struct ndisc_options ndopts;
1013         u8 *lladdr = NULL;
1014
1015         if (skb->len < sizeof(*rs_msg))
1016                 return;
1017
1018         idev = in6_dev_get(skb->dev);
1019         if (!idev) {
1020                 if (net_ratelimit())
1021                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1022                 return;
1023         }
1024
1025         /* Don't accept RS if we're not in router mode */
1026         if (!idev->cnf.forwarding)
1027                 goto out;
1028
1029         /*
1030          * Don't update NCE if src = ::;
1031          * this implies that the source node has no ip address assigned yet.
1032          */
1033         if (ipv6_addr_any(saddr))
1034                 goto out;
1035
1036         /* Parse ND options */
1037         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1038                 if (net_ratelimit())
1039                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1040                 goto out;
1041         }
1042
1043         if (ndopts.nd_opts_src_lladdr) {
1044                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1045                                              skb->dev);
1046                 if (!lladdr)
1047                         goto out;
1048         }
1049
1050         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1051         if (neigh) {
1052                 neigh_update(neigh, lladdr, NUD_STALE,
1053                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1054                              NEIGH_UPDATE_F_OVERRIDE|
1055                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1056                 neigh_release(neigh);
1057         }
1058 out:
1059         in6_dev_put(idev);
1060 }
1061
1062 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1063 {
1064         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1065         struct sk_buff *skb;
1066         struct nlmsghdr *nlh;
1067         struct nduseroptmsg *ndmsg;
1068         struct net *net = dev_net(ra->dev);
1069         int err;
1070         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1071                                     + (opt->nd_opt_len << 3));
1072         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1073
1074         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1075         if (skb == NULL) {
1076                 err = -ENOBUFS;
1077                 goto errout;
1078         }
1079
1080         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1081         if (nlh == NULL) {
1082                 goto nla_put_failure;
1083         }
1084
1085         ndmsg = nlmsg_data(nlh);
1086         ndmsg->nduseropt_family = AF_INET6;
1087         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1088         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1089         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1090         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1091
1092         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1093
1094         NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1095                 &ipv6_hdr(ra)->saddr);
1096         nlmsg_end(skb, nlh);
1097
1098         rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1099         return;
1100
1101 nla_put_failure:
1102         nlmsg_free(skb);
1103         err = -EMSGSIZE;
1104 errout:
1105         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1106 }
1107
1108 static void ndisc_router_discovery(struct sk_buff *skb)
1109 {
1110         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1111         struct neighbour *neigh = NULL;
1112         struct inet6_dev *in6_dev;
1113         struct rt6_info *rt = NULL;
1114         int lifetime;
1115         struct ndisc_options ndopts;
1116         int optlen;
1117         unsigned int pref = 0;
1118
1119         __u8 * opt = (__u8 *)(ra_msg + 1);
1120
1121         optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1122
1123         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1124                 ND_PRINTK2(KERN_WARNING
1125                            "ICMPv6 RA: source address is not link-local.\n");
1126                 return;
1127         }
1128         if (optlen < 0) {
1129                 ND_PRINTK2(KERN_WARNING
1130                            "ICMPv6 RA: packet too short\n");
1131                 return;
1132         }
1133
1134 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1135         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1136                 ND_PRINTK2(KERN_WARNING
1137                            "ICMPv6 RA: from host or unauthorized router\n");
1138                 return;
1139         }
1140 #endif
1141
1142         /*
1143          *      set the RA_RECV flag in the interface
1144          */
1145
1146         in6_dev = in6_dev_get(skb->dev);
1147         if (in6_dev == NULL) {
1148                 ND_PRINTK0(KERN_ERR
1149                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1150                            skb->dev->name);
1151                 return;
1152         }
1153
1154         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1155                 in6_dev_put(in6_dev);
1156                 ND_PRINTK2(KERN_WARNING
1157                            "ICMP6 RA: invalid ND options\n");
1158                 return;
1159         }
1160
1161         /* skip route and link configuration on routers */
1162         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra)
1163                 goto skip_linkparms;
1164
1165 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1166         /* skip link-specific parameters from interior routers */
1167         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1168                 goto skip_linkparms;
1169 #endif
1170
1171         if (in6_dev->if_flags & IF_RS_SENT) {
1172                 /*
1173                  *      flag that an RA was received after an RS was sent
1174                  *      out on this interface.
1175                  */
1176                 in6_dev->if_flags |= IF_RA_RCVD;
1177         }
1178
1179         /*
1180          * Remember the managed/otherconf flags from most recently
1181          * received RA message (RFC 2462) -- yoshfuji
1182          */
1183         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1184                                 IF_RA_OTHERCONF)) |
1185                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1186                                         IF_RA_MANAGED : 0) |
1187                                 (ra_msg->icmph.icmp6_addrconf_other ?
1188                                         IF_RA_OTHERCONF : 0);
1189
1190         if (!in6_dev->cnf.accept_ra_defrtr)
1191                 goto skip_defrtr;
1192
1193         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1194
1195 #ifdef CONFIG_IPV6_ROUTER_PREF
1196         pref = ra_msg->icmph.icmp6_router_pref;
1197         /* 10b is handled as if it were 00b (medium) */
1198         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1199             !in6_dev->cnf.accept_ra_rtr_pref)
1200                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1201 #endif
1202
1203         rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1204
1205         if (rt)
1206                 neigh = rt->rt6i_nexthop;
1207
1208         if (rt && lifetime == 0) {
1209                 neigh_clone(neigh);
1210                 ip6_del_rt(rt);
1211                 rt = NULL;
1212         }
1213
1214         if (rt == NULL && lifetime) {
1215                 ND_PRINTK3(KERN_DEBUG
1216                            "ICMPv6 RA: adding default router.\n");
1217
1218                 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1219                 if (rt == NULL) {
1220                         ND_PRINTK0(KERN_ERR
1221                                    "ICMPv6 RA: %s() failed to add default route.\n",
1222                                    __func__);
1223                         in6_dev_put(in6_dev);
1224                         return;
1225                 }
1226
1227                 neigh = rt->rt6i_nexthop;
1228                 if (neigh == NULL) {
1229                         ND_PRINTK0(KERN_ERR
1230                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1231                                    __func__);
1232                         dst_release(&rt->u.dst);
1233                         in6_dev_put(in6_dev);
1234                         return;
1235                 }
1236                 neigh->flags |= NTF_ROUTER;
1237         } else if (rt) {
1238                 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1239         }
1240
1241         if (rt)
1242                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1243
1244         if (ra_msg->icmph.icmp6_hop_limit) {
1245                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1246                 if (rt)
1247                         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1248         }
1249
1250 skip_defrtr:
1251
1252         /*
1253          *      Update Reachable Time and Retrans Timer
1254          */
1255
1256         if (in6_dev->nd_parms) {
1257                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1258
1259                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1260                         rtime = (rtime*HZ)/1000;
1261                         if (rtime < HZ/10)
1262                                 rtime = HZ/10;
1263                         in6_dev->nd_parms->retrans_time = rtime;
1264                         in6_dev->tstamp = jiffies;
1265                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1266                 }
1267
1268                 rtime = ntohl(ra_msg->reachable_time);
1269                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1270                         rtime = (rtime*HZ)/1000;
1271
1272                         if (rtime < HZ/10)
1273                                 rtime = HZ/10;
1274
1275                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1276                                 in6_dev->nd_parms->base_reachable_time = rtime;
1277                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1278                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1279                                 in6_dev->tstamp = jiffies;
1280                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1281                         }
1282                 }
1283         }
1284
1285 skip_linkparms:
1286
1287         /*
1288          *      Process options.
1289          */
1290
1291         if (!neigh)
1292                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1293                                        skb->dev, 1);
1294         if (neigh) {
1295                 u8 *lladdr = NULL;
1296                 if (ndopts.nd_opts_src_lladdr) {
1297                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1298                                                      skb->dev);
1299                         if (!lladdr) {
1300                                 ND_PRINTK2(KERN_WARNING
1301                                            "ICMPv6 RA: invalid link-layer address length\n");
1302                                 goto out;
1303                         }
1304                 }
1305                 neigh_update(neigh, lladdr, NUD_STALE,
1306                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1307                              NEIGH_UPDATE_F_OVERRIDE|
1308                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1309                              NEIGH_UPDATE_F_ISROUTER);
1310         }
1311
1312         /* skip route and link configuration on routers */
1313         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra)
1314                 goto out;
1315
1316 #ifdef CONFIG_IPV6_ROUTE_INFO
1317         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1318                 struct nd_opt_hdr *p;
1319                 for (p = ndopts.nd_opts_ri;
1320                      p;
1321                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1322                         struct route_info *ri = (struct route_info *)p;
1323 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1324                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1325                             ri->prefix_len == 0)
1326                                 continue;
1327 #endif
1328                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1329                                 continue;
1330                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1331                                       &ipv6_hdr(skb)->saddr);
1332                 }
1333         }
1334 #endif
1335
1336 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1337         /* skip link-specific ndopts from interior routers */
1338         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1339                 goto out;
1340 #endif
1341
1342         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1343                 struct nd_opt_hdr *p;
1344                 for (p = ndopts.nd_opts_pi;
1345                      p;
1346                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1347                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1348                 }
1349         }
1350
1351         if (ndopts.nd_opts_mtu) {
1352                 __be32 n;
1353                 u32 mtu;
1354
1355                 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1356                 mtu = ntohl(n);
1357
1358                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1359                         ND_PRINTK2(KERN_WARNING
1360                                    "ICMPv6 RA: invalid mtu: %d\n",
1361                                    mtu);
1362                 } else if (in6_dev->cnf.mtu6 != mtu) {
1363                         in6_dev->cnf.mtu6 = mtu;
1364
1365                         if (rt)
1366                                 rt->u.dst.metrics[RTAX_MTU-1] = mtu;
1367
1368                         rt6_mtu_change(skb->dev, mtu);
1369                 }
1370         }
1371
1372         if (ndopts.nd_useropts) {
1373                 struct nd_opt_hdr *p;
1374                 for (p = ndopts.nd_useropts;
1375                      p;
1376                      p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1377                         ndisc_ra_useropt(skb, p);
1378                 }
1379         }
1380
1381         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1382                 ND_PRINTK2(KERN_WARNING
1383                            "ICMPv6 RA: invalid RA options");
1384         }
1385 out:
1386         if (rt)
1387                 dst_release(&rt->u.dst);
1388         else if (neigh)
1389                 neigh_release(neigh);
1390         in6_dev_put(in6_dev);
1391 }
1392
1393 static void ndisc_redirect_rcv(struct sk_buff *skb)
1394 {
1395         struct inet6_dev *in6_dev;
1396         struct icmp6hdr *icmph;
1397         struct in6_addr *dest;
1398         struct in6_addr *target;        /* new first hop to destination */
1399         struct neighbour *neigh;
1400         int on_link = 0;
1401         struct ndisc_options ndopts;
1402         int optlen;
1403         u8 *lladdr = NULL;
1404
1405 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1406         switch (skb->ndisc_nodetype) {
1407         case NDISC_NODETYPE_HOST:
1408         case NDISC_NODETYPE_NODEFAULT:
1409                 ND_PRINTK2(KERN_WARNING
1410                            "ICMPv6 Redirect: from host or unauthorized router\n");
1411                 return;
1412         }
1413 #endif
1414
1415         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1416                 ND_PRINTK2(KERN_WARNING
1417                            "ICMPv6 Redirect: source address is not link-local.\n");
1418                 return;
1419         }
1420
1421         optlen = skb->tail - skb->transport_header;
1422         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1423
1424         if (optlen < 0) {
1425                 ND_PRINTK2(KERN_WARNING
1426                            "ICMPv6 Redirect: packet too short\n");
1427                 return;
1428         }
1429
1430         icmph = icmp6_hdr(skb);
1431         target = (struct in6_addr *) (icmph + 1);
1432         dest = target + 1;
1433
1434         if (ipv6_addr_is_multicast(dest)) {
1435                 ND_PRINTK2(KERN_WARNING
1436                            "ICMPv6 Redirect: destination address is multicast.\n");
1437                 return;
1438         }
1439
1440         if (ipv6_addr_equal(dest, target)) {
1441                 on_link = 1;
1442         } else if (ipv6_addr_type(target) !=
1443                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1444                 ND_PRINTK2(KERN_WARNING
1445                            "ICMPv6 Redirect: target address is not link-local unicast.\n");
1446                 return;
1447         }
1448
1449         in6_dev = in6_dev_get(skb->dev);
1450         if (!in6_dev)
1451                 return;
1452         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1453                 in6_dev_put(in6_dev);
1454                 return;
1455         }
1456
1457         /* RFC2461 8.1:
1458          *      The IP source address of the Redirect MUST be the same as the current
1459          *      first-hop router for the specified ICMP Destination Address.
1460          */
1461
1462         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1463                 ND_PRINTK2(KERN_WARNING
1464                            "ICMPv6 Redirect: invalid ND options\n");
1465                 in6_dev_put(in6_dev);
1466                 return;
1467         }
1468         if (ndopts.nd_opts_tgt_lladdr) {
1469                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1470                                              skb->dev);
1471                 if (!lladdr) {
1472                         ND_PRINTK2(KERN_WARNING
1473                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1474                         in6_dev_put(in6_dev);
1475                         return;
1476                 }
1477         }
1478
1479         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1480         if (neigh) {
1481                 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1482                              &ipv6_hdr(skb)->saddr, neigh, lladdr,
1483                              on_link);
1484                 neigh_release(neigh);
1485         }
1486         in6_dev_put(in6_dev);
1487 }
1488
1489 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1490                          const struct in6_addr *target)
1491 {
1492         struct net_device *dev = skb->dev;
1493         struct net *net = dev_net(dev);
1494         struct sock *sk = net->ipv6.ndisc_sk;
1495         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1496         struct sk_buff *buff;
1497         struct icmp6hdr *icmph;
1498         struct in6_addr saddr_buf;
1499         struct in6_addr *addrp;
1500         struct rt6_info *rt;
1501         struct dst_entry *dst;
1502         struct inet6_dev *idev;
1503         struct flowi fl;
1504         u8 *opt;
1505         int rd_len;
1506         int err;
1507         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1508
1509         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1510                 ND_PRINTK2(KERN_WARNING
1511                            "ICMPv6 Redirect: no link-local address on %s\n",
1512                            dev->name);
1513                 return;
1514         }
1515
1516         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1517             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1518                 ND_PRINTK2(KERN_WARNING
1519                         "ICMPv6 Redirect: target address is not link-local unicast.\n");
1520                 return;
1521         }
1522
1523         icmpv6_flow_init(sk, &fl, NDISC_REDIRECT,
1524                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1525
1526         dst = ip6_route_output(net, NULL, &fl);
1527         if (dst == NULL)
1528                 return;
1529
1530         err = xfrm_lookup(net, &dst, &fl, NULL, 0);
1531         if (err)
1532                 return;
1533
1534         rt = (struct rt6_info *) dst;
1535
1536         if (rt->rt6i_flags & RTF_GATEWAY) {
1537                 ND_PRINTK2(KERN_WARNING
1538                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1539                 goto release;
1540         }
1541         if (!xrlim_allow(dst, 1*HZ))
1542                 goto release;
1543
1544         if (dev->addr_len) {
1545                 read_lock_bh(&neigh->lock);
1546                 if (neigh->nud_state & NUD_VALID) {
1547                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1548                         read_unlock_bh(&neigh->lock);
1549                         ha = ha_buf;
1550                         len += ndisc_opt_addr_space(dev);
1551                 } else
1552                         read_unlock_bh(&neigh->lock);
1553         }
1554
1555         rd_len = min_t(unsigned int,
1556                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1557         rd_len &= ~0x7;
1558         len += rd_len;
1559
1560         buff = sock_alloc_send_skb(sk,
1561                                    (MAX_HEADER + sizeof(struct ipv6hdr) +
1562                                     len + LL_ALLOCATED_SPACE(dev)),
1563                                    1, &err);
1564         if (buff == NULL) {
1565                 ND_PRINTK0(KERN_ERR
1566                            "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1567                            __func__, err);
1568                 goto release;
1569         }
1570
1571         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1572         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1573                    IPPROTO_ICMPV6, len);
1574
1575         skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1576         skb_put(buff, len);
1577         icmph = icmp6_hdr(buff);
1578
1579         memset(icmph, 0, sizeof(struct icmp6hdr));
1580         icmph->icmp6_type = NDISC_REDIRECT;
1581
1582         /*
1583          *      copy target and destination addresses
1584          */
1585
1586         addrp = (struct in6_addr *)(icmph + 1);
1587         ipv6_addr_copy(addrp, target);
1588         addrp++;
1589         ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1590
1591         opt = (u8*) (addrp + 1);
1592
1593         /*
1594          *      include target_address option
1595          */
1596
1597         if (ha)
1598                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1599                                              dev->addr_len, dev->type);
1600
1601         /*
1602          *      build redirect option and copy skb over to the new packet.
1603          */
1604
1605         memset(opt, 0, 8);
1606         *(opt++) = ND_OPT_REDIRECT_HDR;
1607         *(opt++) = (rd_len >> 3);
1608         opt += 6;
1609
1610         memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1611
1612         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1613                                              len, IPPROTO_ICMPV6,
1614                                              csum_partial(icmph, len, 0));
1615
1616         skb_dst_set(buff, dst);
1617         idev = in6_dev_get(dst->dev);
1618         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1619         err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1620                       dst_output);
1621         if (!err) {
1622                 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1623                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1624         }
1625
1626         if (likely(idev != NULL))
1627                 in6_dev_put(idev);
1628         return;
1629
1630 release:
1631         dst_release(dst);
1632 }
1633
1634 static void pndisc_redo(struct sk_buff *skb)
1635 {
1636         ndisc_recv_ns(skb);
1637         kfree_skb(skb);
1638 }
1639
1640 int ndisc_rcv(struct sk_buff *skb)
1641 {
1642         struct nd_msg *msg;
1643
1644         if (!pskb_may_pull(skb, skb->len))
1645                 return 0;
1646
1647         msg = (struct nd_msg *)skb_transport_header(skb);
1648
1649         __skb_push(skb, skb->data - skb_transport_header(skb));
1650
1651         if (ipv6_hdr(skb)->hop_limit != 255) {
1652                 ND_PRINTK2(KERN_WARNING
1653                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1654                            ipv6_hdr(skb)->hop_limit);
1655                 return 0;
1656         }
1657
1658         if (msg->icmph.icmp6_code != 0) {
1659                 ND_PRINTK2(KERN_WARNING
1660                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1661                            msg->icmph.icmp6_code);
1662                 return 0;
1663         }
1664
1665         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1666
1667         switch (msg->icmph.icmp6_type) {
1668         case NDISC_NEIGHBOUR_SOLICITATION:
1669                 ndisc_recv_ns(skb);
1670                 break;
1671
1672         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1673                 ndisc_recv_na(skb);
1674                 break;
1675
1676         case NDISC_ROUTER_SOLICITATION:
1677                 ndisc_recv_rs(skb);
1678                 break;
1679
1680         case NDISC_ROUTER_ADVERTISEMENT:
1681                 ndisc_router_discovery(skb);
1682                 break;
1683
1684         case NDISC_REDIRECT:
1685                 ndisc_redirect_rcv(skb);
1686                 break;
1687         }
1688
1689         return 0;
1690 }
1691
1692 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1693 {
1694         struct net_device *dev = ptr;
1695         struct net *net = dev_net(dev);
1696
1697         switch (event) {
1698         case NETDEV_CHANGEADDR:
1699                 neigh_changeaddr(&nd_tbl, dev);
1700                 fib6_run_gc(~0UL, net);
1701                 break;
1702         case NETDEV_DOWN:
1703                 neigh_ifdown(&nd_tbl, dev);
1704                 fib6_run_gc(~0UL, net);
1705                 break;
1706         default:
1707                 break;
1708         }
1709
1710         return NOTIFY_DONE;
1711 }
1712
1713 static struct notifier_block ndisc_netdev_notifier = {
1714         .notifier_call = ndisc_netdev_event,
1715 };
1716
1717 #ifdef CONFIG_SYSCTL
1718 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1719                                          const char *func, const char *dev_name)
1720 {
1721         static char warncomm[TASK_COMM_LEN];
1722         static int warned;
1723         if (strcmp(warncomm, current->comm) && warned < 5) {
1724                 strcpy(warncomm, current->comm);
1725                 printk(KERN_WARNING
1726                         "process `%s' is using deprecated sysctl (%s) "
1727                         "net.ipv6.neigh.%s.%s; "
1728                         "Use net.ipv6.neigh.%s.%s_ms "
1729                         "instead.\n",
1730                         warncomm, func,
1731                         dev_name, ctl->procname,
1732                         dev_name, ctl->procname);
1733                 warned++;
1734         }
1735 }
1736
1737 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1738 {
1739         struct net_device *dev = ctl->extra1;
1740         struct inet6_dev *idev;
1741         int ret;
1742
1743         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1744             (strcmp(ctl->procname, "base_reachable_time") == 0))
1745                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1746
1747         if (strcmp(ctl->procname, "retrans_time") == 0)
1748                 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1749
1750         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1751                 ret = proc_dointvec_jiffies(ctl, write,
1752                                             buffer, lenp, ppos);
1753
1754         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1755                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1756                 ret = proc_dointvec_ms_jiffies(ctl, write,
1757                                                buffer, lenp, ppos);
1758         else
1759                 ret = -1;
1760
1761         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1762                 if (ctl->data == &idev->nd_parms->base_reachable_time)
1763                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1764                 idev->tstamp = jiffies;
1765                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1766                 in6_dev_put(idev);
1767         }
1768         return ret;
1769 }
1770
1771 int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl,
1772                                  void __user *oldval, size_t __user *oldlenp,
1773                                  void __user *newval, size_t newlen)
1774 {
1775         struct net_device *dev = ctl->extra1;
1776         struct inet6_dev *idev;
1777         int ret;
1778
1779         if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1780             ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1781                 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default");
1782
1783         switch (ctl->ctl_name) {
1784         case NET_NEIGH_REACHABLE_TIME:
1785                 ret = sysctl_jiffies(ctl, oldval, oldlenp, newval, newlen);
1786                 break;
1787         case NET_NEIGH_RETRANS_TIME_MS:
1788         case NET_NEIGH_REACHABLE_TIME_MS:
1789                  ret = sysctl_ms_jiffies(ctl, oldval, oldlenp, newval, newlen);
1790                  break;
1791         default:
1792                 ret = 0;
1793         }
1794
1795         if (newval && newlen && ret > 0 &&
1796             dev && (idev = in6_dev_get(dev)) != NULL) {
1797                 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1798                     ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1799                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1800                 idev->tstamp = jiffies;
1801                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1802                 in6_dev_put(idev);
1803         }
1804
1805         return ret;
1806 }
1807
1808 #endif
1809
1810 static int ndisc_net_init(struct net *net)
1811 {
1812         struct ipv6_pinfo *np;
1813         struct sock *sk;
1814         int err;
1815
1816         err = inet_ctl_sock_create(&sk, PF_INET6,
1817                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1818         if (err < 0) {
1819                 ND_PRINTK0(KERN_ERR
1820                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1821                            err);
1822                 return err;
1823         }
1824
1825         net->ipv6.ndisc_sk = sk;
1826
1827         np = inet6_sk(sk);
1828         np->hop_limit = 255;
1829         /* Do not loopback ndisc messages */
1830         np->mc_loop = 0;
1831
1832         return 0;
1833 }
1834
1835 static void ndisc_net_exit(struct net *net)
1836 {
1837         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1838 }
1839
1840 static struct pernet_operations ndisc_net_ops = {
1841         .init = ndisc_net_init,
1842         .exit = ndisc_net_exit,
1843 };
1844
1845 int __init ndisc_init(void)
1846 {
1847         int err;
1848
1849         err = register_pernet_subsys(&ndisc_net_ops);
1850         if (err)
1851                 return err;
1852         /*
1853          * Initialize the neighbour table
1854          */
1855         neigh_table_init(&nd_tbl);
1856
1857 #ifdef CONFIG_SYSCTL
1858         err = neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6,
1859                                     NET_IPV6_NEIGH, "ipv6",
1860                                     &ndisc_ifinfo_sysctl_change,
1861                                     &ndisc_ifinfo_sysctl_strategy);
1862         if (err)
1863                 goto out_unregister_pernet;
1864 #endif
1865         err = register_netdevice_notifier(&ndisc_netdev_notifier);
1866         if (err)
1867                 goto out_unregister_sysctl;
1868 out:
1869         return err;
1870
1871 out_unregister_sysctl:
1872 #ifdef CONFIG_SYSCTL
1873         neigh_sysctl_unregister(&nd_tbl.parms);
1874 out_unregister_pernet:
1875 #endif
1876         unregister_pernet_subsys(&ndisc_net_ops);
1877         goto out;
1878 }
1879
1880 void ndisc_cleanup(void)
1881 {
1882         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1883 #ifdef CONFIG_SYSCTL
1884         neigh_sysctl_unregister(&nd_tbl.parms);
1885 #endif
1886         neigh_table_clear(&nd_tbl);
1887         unregister_pernet_subsys(&ndisc_net_ops);
1888 }