01a0ffc7b402c3e3be069253065ffa81b87d91a3
[linux-3.10.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 static void ndisc_send_unsol_na(struct net_device *dev)
615 {
616         struct inet6_dev *idev;
617         struct inet6_ifaddr *ifa;
618         struct in6_addr mcaddr;
619
620         idev = in6_dev_get(dev);
621         if (!idev)
622                 return;
623
624         read_lock_bh(&idev->lock);
625         list_for_each_entry(ifa, &idev->addr_list, if_list) {
626                 addrconf_addr_solict_mult(&ifa->addr, &mcaddr);
627                 ndisc_send_na(dev, NULL, &mcaddr, &ifa->addr,
628                               /*router=*/ !!idev->cnf.forwarding,
629                               /*solicited=*/ false, /*override=*/ true,
630                               /*inc_opt=*/ true);
631         }
632         read_unlock_bh(&idev->lock);
633
634         in6_dev_put(idev);
635 }
636
637 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
638                    const struct in6_addr *solicit,
639                    const struct in6_addr *daddr, const struct in6_addr *saddr)
640 {
641         struct in6_addr addr_buf;
642         struct icmp6hdr icmp6h = {
643                 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
644         };
645
646         if (saddr == NULL) {
647                 if (ipv6_get_lladdr(dev, &addr_buf,
648                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
649                         return;
650                 saddr = &addr_buf;
651         }
652
653         __ndisc_send(dev, neigh, daddr, saddr,
654                      &icmp6h, solicit,
655                      !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
656 }
657
658 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
659                    const struct in6_addr *daddr)
660 {
661         struct icmp6hdr icmp6h = {
662                 .icmp6_type = NDISC_ROUTER_SOLICITATION,
663         };
664         int send_sllao = dev->addr_len;
665
666 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
667         /*
668          * According to section 2.2 of RFC 4429, we must not
669          * send router solicitations with a sllao from
670          * optimistic addresses, but we may send the solicitation
671          * if we don't include the sllao.  So here we check
672          * if our address is optimistic, and if so, we
673          * suppress the inclusion of the sllao.
674          */
675         if (send_sllao) {
676                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
677                                                            dev, 1);
678                 if (ifp) {
679                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
680                                 send_sllao = 0;
681                         }
682                         in6_ifa_put(ifp);
683                 } else {
684                         send_sllao = 0;
685                 }
686         }
687 #endif
688         __ndisc_send(dev, NULL, daddr, saddr,
689                      &icmp6h, NULL,
690                      send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
691 }
692
693
694 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
695 {
696         /*
697          *      "The sender MUST return an ICMP
698          *       destination unreachable"
699          */
700         dst_link_failure(skb);
701         kfree_skb(skb);
702 }
703
704 /* Called with locked neigh: either read or both */
705
706 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
707 {
708         struct in6_addr *saddr = NULL;
709         struct in6_addr mcaddr;
710         struct net_device *dev = neigh->dev;
711         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
712         int probes = atomic_read(&neigh->probes);
713
714         if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
715                 saddr = &ipv6_hdr(skb)->saddr;
716
717         if ((probes -= neigh->parms->ucast_probes) < 0) {
718                 if (!(neigh->nud_state & NUD_VALID)) {
719                         ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
720                                    __func__, target);
721                 }
722                 ndisc_send_ns(dev, neigh, target, target, saddr);
723         } else if ((probes -= neigh->parms->app_probes) < 0) {
724 #ifdef CONFIG_ARPD
725                 neigh_app_ns(neigh);
726 #endif
727         } else {
728                 addrconf_addr_solict_mult(target, &mcaddr);
729                 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
730         }
731 }
732
733 static int pndisc_is_router(const void *pkey,
734                             struct net_device *dev)
735 {
736         struct pneigh_entry *n;
737         int ret = -1;
738
739         read_lock_bh(&nd_tbl.lock);
740         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
741         if (n)
742                 ret = !!(n->flags & NTF_ROUTER);
743         read_unlock_bh(&nd_tbl.lock);
744
745         return ret;
746 }
747
748 static void ndisc_recv_ns(struct sk_buff *skb)
749 {
750         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
751         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
752         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
753         u8 *lladdr = NULL;
754         u32 ndoptlen = skb->tail - (skb->transport_header +
755                                     offsetof(struct nd_msg, opt));
756         struct ndisc_options ndopts;
757         struct net_device *dev = skb->dev;
758         struct inet6_ifaddr *ifp;
759         struct inet6_dev *idev = NULL;
760         struct neighbour *neigh;
761         int dad = ipv6_addr_any(saddr);
762         int inc;
763         int is_router = -1;
764
765         if (ipv6_addr_is_multicast(&msg->target)) {
766                 ND_PRINTK2(KERN_WARNING
767                            "ICMPv6 NS: multicast target address");
768                 return;
769         }
770
771         /*
772          * RFC2461 7.1.1:
773          * DAD has to be destined for solicited node multicast address.
774          */
775         if (dad &&
776             !(daddr->s6_addr32[0] == htonl(0xff020000) &&
777               daddr->s6_addr32[1] == htonl(0x00000000) &&
778               daddr->s6_addr32[2] == htonl(0x00000001) &&
779               daddr->s6_addr [12] == 0xff )) {
780                 ND_PRINTK2(KERN_WARNING
781                            "ICMPv6 NS: bad DAD packet (wrong destination)\n");
782                 return;
783         }
784
785         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
786                 ND_PRINTK2(KERN_WARNING
787                            "ICMPv6 NS: invalid ND options\n");
788                 return;
789         }
790
791         if (ndopts.nd_opts_src_lladdr) {
792                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
793                 if (!lladdr) {
794                         ND_PRINTK2(KERN_WARNING
795                                    "ICMPv6 NS: invalid link-layer address length\n");
796                         return;
797                 }
798
799                 /* RFC2461 7.1.1:
800                  *      If the IP source address is the unspecified address,
801                  *      there MUST NOT be source link-layer address option
802                  *      in the message.
803                  */
804                 if (dad) {
805                         ND_PRINTK2(KERN_WARNING
806                                    "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
807                         return;
808                 }
809         }
810
811         inc = ipv6_addr_is_multicast(daddr);
812
813         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
814         if (ifp) {
815
816                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
817                         if (dad) {
818                                 if (dev->type == ARPHRD_IEEE802_TR) {
819                                         const unsigned char *sadr;
820                                         sadr = skb_mac_header(skb);
821                                         if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
822                                             sadr[9] == dev->dev_addr[1] &&
823                                             sadr[10] == dev->dev_addr[2] &&
824                                             sadr[11] == dev->dev_addr[3] &&
825                                             sadr[12] == dev->dev_addr[4] &&
826                                             sadr[13] == dev->dev_addr[5]) {
827                                                 /* looped-back to us */
828                                                 goto out;
829                                         }
830                                 }
831
832                                 /*
833                                  * We are colliding with another node
834                                  * who is doing DAD
835                                  * so fail our DAD process
836                                  */
837                                 addrconf_dad_failure(ifp);
838                                 return;
839                         } else {
840                                 /*
841                                  * This is not a dad solicitation.
842                                  * If we are an optimistic node,
843                                  * we should respond.
844                                  * Otherwise, we should ignore it.
845                                  */
846                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
847                                         goto out;
848                         }
849                 }
850
851                 idev = ifp->idev;
852         } else {
853                 struct net *net = dev_net(dev);
854
855                 idev = in6_dev_get(dev);
856                 if (!idev) {
857                         /* XXX: count this drop? */
858                         return;
859                 }
860
861                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
862                     (idev->cnf.forwarding &&
863                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
864                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
865                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
866                             skb->pkt_type != PACKET_HOST &&
867                             inc != 0 &&
868                             idev->nd_parms->proxy_delay != 0) {
869                                 /*
870                                  * for anycast or proxy,
871                                  * sender should delay its response
872                                  * by a random time between 0 and
873                                  * MAX_ANYCAST_DELAY_TIME seconds.
874                                  * (RFC2461) -- yoshfuji
875                                  */
876                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
877                                 if (n)
878                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
879                                 goto out;
880                         }
881                 } else
882                         goto out;
883         }
884
885         if (is_router < 0)
886                 is_router = !!idev->cnf.forwarding;
887
888         if (dad) {
889                 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
890                               is_router, 0, (ifp != NULL), 1);
891                 goto out;
892         }
893
894         if (inc)
895                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
896         else
897                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
898
899         /*
900          *      update / create cache entry
901          *      for the source address
902          */
903         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
904                                !inc || lladdr || !dev->addr_len);
905         if (neigh)
906                 neigh_update(neigh, lladdr, NUD_STALE,
907                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
908                              NEIGH_UPDATE_F_OVERRIDE);
909         if (neigh || !dev->header_ops) {
910                 ndisc_send_na(dev, neigh, saddr, &msg->target,
911                               is_router,
912                               1, (ifp != NULL && inc), inc);
913                 if (neigh)
914                         neigh_release(neigh);
915         }
916
917 out:
918         if (ifp)
919                 in6_ifa_put(ifp);
920         else
921                 in6_dev_put(idev);
922 }
923
924 static void ndisc_recv_na(struct sk_buff *skb)
925 {
926         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
927         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
928         struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
929         u8 *lladdr = NULL;
930         u32 ndoptlen = skb->tail - (skb->transport_header +
931                                     offsetof(struct nd_msg, opt));
932         struct ndisc_options ndopts;
933         struct net_device *dev = skb->dev;
934         struct inet6_ifaddr *ifp;
935         struct neighbour *neigh;
936
937         if (skb->len < sizeof(struct nd_msg)) {
938                 ND_PRINTK2(KERN_WARNING
939                            "ICMPv6 NA: packet too short\n");
940                 return;
941         }
942
943         if (ipv6_addr_is_multicast(&msg->target)) {
944                 ND_PRINTK2(KERN_WARNING
945                            "ICMPv6 NA: target address is multicast.\n");
946                 return;
947         }
948
949         if (ipv6_addr_is_multicast(daddr) &&
950             msg->icmph.icmp6_solicited) {
951                 ND_PRINTK2(KERN_WARNING
952                            "ICMPv6 NA: solicited NA is multicasted.\n");
953                 return;
954         }
955
956         if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
957                 ND_PRINTK2(KERN_WARNING
958                            "ICMPv6 NS: invalid ND option\n");
959                 return;
960         }
961         if (ndopts.nd_opts_tgt_lladdr) {
962                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
963                 if (!lladdr) {
964                         ND_PRINTK2(KERN_WARNING
965                                    "ICMPv6 NA: invalid link-layer address length\n");
966                         return;
967                 }
968         }
969         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
970         if (ifp) {
971                 if (skb->pkt_type != PACKET_LOOPBACK
972                     && (ifp->flags & IFA_F_TENTATIVE)) {
973                                 addrconf_dad_failure(ifp);
974                                 return;
975                 }
976                 /* What should we make now? The advertisement
977                    is invalid, but ndisc specs say nothing
978                    about it. It could be misconfiguration, or
979                    an smart proxy agent tries to help us :-)
980
981                    We should not print the error if NA has been
982                    received from loopback - it is just our own
983                    unsolicited advertisement.
984                  */
985                 if (skb->pkt_type != PACKET_LOOPBACK)
986                         ND_PRINTK1(KERN_WARNING
987                            "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
988                            &ifp->addr, ifp->idev->dev->name);
989                 in6_ifa_put(ifp);
990                 return;
991         }
992         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
993
994         if (neigh) {
995                 u8 old_flags = neigh->flags;
996                 struct net *net = dev_net(dev);
997
998                 if (neigh->nud_state & NUD_FAILED)
999                         goto out;
1000
1001                 /*
1002                  * Don't update the neighbor cache entry on a proxy NA from
1003                  * ourselves because either the proxied node is off link or it
1004                  * has already sent a NA to us.
1005                  */
1006                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1007                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1008                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1009                         /* XXX: idev->cnf.prixy_ndp */
1010                         goto out;
1011                 }
1012
1013                 neigh_update(neigh, lladdr,
1014                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1015                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1016                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1017                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1018                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
1019
1020                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1021                         /*
1022                          * Change: router to host
1023                          */
1024                         struct rt6_info *rt;
1025                         rt = rt6_get_dflt_router(saddr, dev);
1026                         if (rt)
1027                                 ip6_del_rt(rt);
1028                 }
1029
1030 out:
1031                 neigh_release(neigh);
1032         }
1033 }
1034
1035 static void ndisc_recv_rs(struct sk_buff *skb)
1036 {
1037         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1038         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1039         struct neighbour *neigh;
1040         struct inet6_dev *idev;
1041         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1042         struct ndisc_options ndopts;
1043         u8 *lladdr = NULL;
1044
1045         if (skb->len < sizeof(*rs_msg))
1046                 return;
1047
1048         idev = in6_dev_get(skb->dev);
1049         if (!idev) {
1050                 if (net_ratelimit())
1051                         ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1052                 return;
1053         }
1054
1055         /* Don't accept RS if we're not in router mode */
1056         if (!idev->cnf.forwarding)
1057                 goto out;
1058
1059         /*
1060          * Don't update NCE if src = ::;
1061          * this implies that the source node has no ip address assigned yet.
1062          */
1063         if (ipv6_addr_any(saddr))
1064                 goto out;
1065
1066         /* Parse ND options */
1067         if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1068                 if (net_ratelimit())
1069                         ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1070                 goto out;
1071         }
1072
1073         if (ndopts.nd_opts_src_lladdr) {
1074                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1075                                              skb->dev);
1076                 if (!lladdr)
1077                         goto out;
1078         }
1079
1080         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1081         if (neigh) {
1082                 neigh_update(neigh, lladdr, NUD_STALE,
1083                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1084                              NEIGH_UPDATE_F_OVERRIDE|
1085                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1086                 neigh_release(neigh);
1087         }
1088 out:
1089         in6_dev_put(idev);
1090 }
1091
1092 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1093 {
1094         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1095         struct sk_buff *skb;
1096         struct nlmsghdr *nlh;
1097         struct nduseroptmsg *ndmsg;
1098         struct net *net = dev_net(ra->dev);
1099         int err;
1100         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1101                                     + (opt->nd_opt_len << 3));
1102         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1103
1104         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1105         if (skb == NULL) {
1106                 err = -ENOBUFS;
1107                 goto errout;
1108         }
1109
1110         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1111         if (nlh == NULL) {
1112                 goto nla_put_failure;
1113         }
1114
1115         ndmsg = nlmsg_data(nlh);
1116         ndmsg->nduseropt_family = AF_INET6;
1117         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1118         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1119         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1120         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1121
1122         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1123
1124         NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1125                 &ipv6_hdr(ra)->saddr);
1126         nlmsg_end(skb, nlh);
1127
1128         rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1129         return;
1130
1131 nla_put_failure:
1132         nlmsg_free(skb);
1133         err = -EMSGSIZE;
1134 errout:
1135         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1136 }
1137
1138 static inline int accept_ra(struct inet6_dev *in6_dev)
1139 {
1140         /*
1141          * If forwarding is enabled, RA are not accepted unless the special
1142          * hybrid mode (accept_ra=2) is enabled.
1143          */
1144         if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2)
1145                 return 0;
1146
1147         return in6_dev->cnf.accept_ra;
1148 }
1149
1150 static void ndisc_router_discovery(struct sk_buff *skb)
1151 {
1152         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1153         struct neighbour *neigh = NULL;
1154         struct inet6_dev *in6_dev;
1155         struct rt6_info *rt = NULL;
1156         int lifetime;
1157         struct ndisc_options ndopts;
1158         int optlen;
1159         unsigned int pref = 0;
1160
1161         __u8 * opt = (__u8 *)(ra_msg + 1);
1162
1163         optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1164
1165         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1166                 ND_PRINTK2(KERN_WARNING
1167                            "ICMPv6 RA: source address is not link-local.\n");
1168                 return;
1169         }
1170         if (optlen < 0) {
1171                 ND_PRINTK2(KERN_WARNING
1172                            "ICMPv6 RA: packet too short\n");
1173                 return;
1174         }
1175
1176 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1177         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1178                 ND_PRINTK2(KERN_WARNING
1179                            "ICMPv6 RA: from host or unauthorized router\n");
1180                 return;
1181         }
1182 #endif
1183
1184         /*
1185          *      set the RA_RECV flag in the interface
1186          */
1187
1188         in6_dev = in6_dev_get(skb->dev);
1189         if (in6_dev == NULL) {
1190                 ND_PRINTK0(KERN_ERR
1191                            "ICMPv6 RA: can't find inet6 device for %s.\n",
1192                            skb->dev->name);
1193                 return;
1194         }
1195
1196         if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1197                 in6_dev_put(in6_dev);
1198                 ND_PRINTK2(KERN_WARNING
1199                            "ICMP6 RA: invalid ND options\n");
1200                 return;
1201         }
1202
1203         if (!accept_ra(in6_dev))
1204                 goto skip_linkparms;
1205
1206 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1207         /* skip link-specific parameters from interior routers */
1208         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1209                 goto skip_linkparms;
1210 #endif
1211
1212         if (in6_dev->if_flags & IF_RS_SENT) {
1213                 /*
1214                  *      flag that an RA was received after an RS was sent
1215                  *      out on this interface.
1216                  */
1217                 in6_dev->if_flags |= IF_RA_RCVD;
1218         }
1219
1220         /*
1221          * Remember the managed/otherconf flags from most recently
1222          * received RA message (RFC 2462) -- yoshfuji
1223          */
1224         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1225                                 IF_RA_OTHERCONF)) |
1226                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1227                                         IF_RA_MANAGED : 0) |
1228                                 (ra_msg->icmph.icmp6_addrconf_other ?
1229                                         IF_RA_OTHERCONF : 0);
1230
1231         if (!in6_dev->cnf.accept_ra_defrtr)
1232                 goto skip_defrtr;
1233
1234         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1235
1236 #ifdef CONFIG_IPV6_ROUTER_PREF
1237         pref = ra_msg->icmph.icmp6_router_pref;
1238         /* 10b is handled as if it were 00b (medium) */
1239         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1240             !in6_dev->cnf.accept_ra_rtr_pref)
1241                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1242 #endif
1243
1244         rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1245
1246         if (rt)
1247                 neigh = rt->rt6i_nexthop;
1248
1249         if (rt && lifetime == 0) {
1250                 neigh_clone(neigh);
1251                 ip6_del_rt(rt);
1252                 rt = NULL;
1253         }
1254
1255         if (rt == NULL && lifetime) {
1256                 ND_PRINTK3(KERN_DEBUG
1257                            "ICMPv6 RA: adding default router.\n");
1258
1259                 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1260                 if (rt == NULL) {
1261                         ND_PRINTK0(KERN_ERR
1262                                    "ICMPv6 RA: %s() failed to add default route.\n",
1263                                    __func__);
1264                         in6_dev_put(in6_dev);
1265                         return;
1266                 }
1267
1268                 neigh = rt->rt6i_nexthop;
1269                 if (neigh == NULL) {
1270                         ND_PRINTK0(KERN_ERR
1271                                    "ICMPv6 RA: %s() got default router without neighbour.\n",
1272                                    __func__);
1273                         dst_release(&rt->dst);
1274                         in6_dev_put(in6_dev);
1275                         return;
1276                 }
1277                 neigh->flags |= NTF_ROUTER;
1278         } else if (rt) {
1279                 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1280         }
1281
1282         if (rt)
1283                 rt->rt6i_expires = jiffies + (HZ * lifetime);
1284
1285         if (ra_msg->icmph.icmp6_hop_limit) {
1286                 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1287                 if (rt)
1288                         dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1289                                        ra_msg->icmph.icmp6_hop_limit);
1290         }
1291
1292 skip_defrtr:
1293
1294         /*
1295          *      Update Reachable Time and Retrans Timer
1296          */
1297
1298         if (in6_dev->nd_parms) {
1299                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1300
1301                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1302                         rtime = (rtime*HZ)/1000;
1303                         if (rtime < HZ/10)
1304                                 rtime = HZ/10;
1305                         in6_dev->nd_parms->retrans_time = rtime;
1306                         in6_dev->tstamp = jiffies;
1307                         inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1308                 }
1309
1310                 rtime = ntohl(ra_msg->reachable_time);
1311                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1312                         rtime = (rtime*HZ)/1000;
1313
1314                         if (rtime < HZ/10)
1315                                 rtime = HZ/10;
1316
1317                         if (rtime != in6_dev->nd_parms->base_reachable_time) {
1318                                 in6_dev->nd_parms->base_reachable_time = rtime;
1319                                 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1320                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1321                                 in6_dev->tstamp = jiffies;
1322                                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1323                         }
1324                 }
1325         }
1326
1327 skip_linkparms:
1328
1329         /*
1330          *      Process options.
1331          */
1332
1333         if (!neigh)
1334                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1335                                        skb->dev, 1);
1336         if (neigh) {
1337                 u8 *lladdr = NULL;
1338                 if (ndopts.nd_opts_src_lladdr) {
1339                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1340                                                      skb->dev);
1341                         if (!lladdr) {
1342                                 ND_PRINTK2(KERN_WARNING
1343                                            "ICMPv6 RA: invalid link-layer address length\n");
1344                                 goto out;
1345                         }
1346                 }
1347                 neigh_update(neigh, lladdr, NUD_STALE,
1348                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1349                              NEIGH_UPDATE_F_OVERRIDE|
1350                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1351                              NEIGH_UPDATE_F_ISROUTER);
1352         }
1353
1354         if (!accept_ra(in6_dev))
1355                 goto out;
1356
1357 #ifdef CONFIG_IPV6_ROUTE_INFO
1358         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1359                 struct nd_opt_hdr *p;
1360                 for (p = ndopts.nd_opts_ri;
1361                      p;
1362                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1363                         struct route_info *ri = (struct route_info *)p;
1364 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1365                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1366                             ri->prefix_len == 0)
1367                                 continue;
1368 #endif
1369                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1370                                 continue;
1371                         rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1372                                       &ipv6_hdr(skb)->saddr);
1373                 }
1374         }
1375 #endif
1376
1377 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1378         /* skip link-specific ndopts from interior routers */
1379         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1380                 goto out;
1381 #endif
1382
1383         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1384                 struct nd_opt_hdr *p;
1385                 for (p = ndopts.nd_opts_pi;
1386                      p;
1387                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1388                         addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1389                 }
1390         }
1391
1392         if (ndopts.nd_opts_mtu) {
1393                 __be32 n;
1394                 u32 mtu;
1395
1396                 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1397                 mtu = ntohl(n);
1398
1399                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1400                         ND_PRINTK2(KERN_WARNING
1401                                    "ICMPv6 RA: invalid mtu: %d\n",
1402                                    mtu);
1403                 } else if (in6_dev->cnf.mtu6 != mtu) {
1404                         in6_dev->cnf.mtu6 = mtu;
1405
1406                         if (rt)
1407                                 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1408
1409                         rt6_mtu_change(skb->dev, mtu);
1410                 }
1411         }
1412
1413         if (ndopts.nd_useropts) {
1414                 struct nd_opt_hdr *p;
1415                 for (p = ndopts.nd_useropts;
1416                      p;
1417                      p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1418                         ndisc_ra_useropt(skb, p);
1419                 }
1420         }
1421
1422         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1423                 ND_PRINTK2(KERN_WARNING
1424                            "ICMPv6 RA: invalid RA options");
1425         }
1426 out:
1427         if (rt)
1428                 dst_release(&rt->dst);
1429         else if (neigh)
1430                 neigh_release(neigh);
1431         in6_dev_put(in6_dev);
1432 }
1433
1434 static void ndisc_redirect_rcv(struct sk_buff *skb)
1435 {
1436         struct inet6_dev *in6_dev;
1437         struct icmp6hdr *icmph;
1438         struct in6_addr *dest;
1439         struct in6_addr *target;        /* new first hop to destination */
1440         struct neighbour *neigh;
1441         int on_link = 0;
1442         struct ndisc_options ndopts;
1443         int optlen;
1444         u8 *lladdr = NULL;
1445
1446 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1447         switch (skb->ndisc_nodetype) {
1448         case NDISC_NODETYPE_HOST:
1449         case NDISC_NODETYPE_NODEFAULT:
1450                 ND_PRINTK2(KERN_WARNING
1451                            "ICMPv6 Redirect: from host or unauthorized router\n");
1452                 return;
1453         }
1454 #endif
1455
1456         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1457                 ND_PRINTK2(KERN_WARNING
1458                            "ICMPv6 Redirect: source address is not link-local.\n");
1459                 return;
1460         }
1461
1462         optlen = skb->tail - skb->transport_header;
1463         optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1464
1465         if (optlen < 0) {
1466                 ND_PRINTK2(KERN_WARNING
1467                            "ICMPv6 Redirect: packet too short\n");
1468                 return;
1469         }
1470
1471         icmph = icmp6_hdr(skb);
1472         target = (struct in6_addr *) (icmph + 1);
1473         dest = target + 1;
1474
1475         if (ipv6_addr_is_multicast(dest)) {
1476                 ND_PRINTK2(KERN_WARNING
1477                            "ICMPv6 Redirect: destination address is multicast.\n");
1478                 return;
1479         }
1480
1481         if (ipv6_addr_equal(dest, target)) {
1482                 on_link = 1;
1483         } else if (ipv6_addr_type(target) !=
1484                    (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1485                 ND_PRINTK2(KERN_WARNING
1486                            "ICMPv6 Redirect: target address is not link-local unicast.\n");
1487                 return;
1488         }
1489
1490         in6_dev = in6_dev_get(skb->dev);
1491         if (!in6_dev)
1492                 return;
1493         if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1494                 in6_dev_put(in6_dev);
1495                 return;
1496         }
1497
1498         /* RFC2461 8.1:
1499          *      The IP source address of the Redirect MUST be the same as the current
1500          *      first-hop router for the specified ICMP Destination Address.
1501          */
1502
1503         if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1504                 ND_PRINTK2(KERN_WARNING
1505                            "ICMPv6 Redirect: invalid ND options\n");
1506                 in6_dev_put(in6_dev);
1507                 return;
1508         }
1509         if (ndopts.nd_opts_tgt_lladdr) {
1510                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1511                                              skb->dev);
1512                 if (!lladdr) {
1513                         ND_PRINTK2(KERN_WARNING
1514                                    "ICMPv6 Redirect: invalid link-layer address length\n");
1515                         in6_dev_put(in6_dev);
1516                         return;
1517                 }
1518         }
1519
1520         neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1521         if (neigh) {
1522                 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1523                              &ipv6_hdr(skb)->saddr, neigh, lladdr,
1524                              on_link);
1525                 neigh_release(neigh);
1526         }
1527         in6_dev_put(in6_dev);
1528 }
1529
1530 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1531                          const struct in6_addr *target)
1532 {
1533         struct net_device *dev = skb->dev;
1534         struct net *net = dev_net(dev);
1535         struct sock *sk = net->ipv6.ndisc_sk;
1536         int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1537         struct sk_buff *buff;
1538         struct icmp6hdr *icmph;
1539         struct in6_addr saddr_buf;
1540         struct in6_addr *addrp;
1541         struct rt6_info *rt;
1542         struct dst_entry *dst;
1543         struct inet6_dev *idev;
1544         struct flowi6 fl6;
1545         u8 *opt;
1546         int rd_len;
1547         int err;
1548         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1549
1550         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1551                 ND_PRINTK2(KERN_WARNING
1552                            "ICMPv6 Redirect: no link-local address on %s\n",
1553                            dev->name);
1554                 return;
1555         }
1556
1557         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1558             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1559                 ND_PRINTK2(KERN_WARNING
1560                         "ICMPv6 Redirect: target address is not link-local unicast.\n");
1561                 return;
1562         }
1563
1564         icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1565                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1566
1567         dst = ip6_route_output(net, NULL, &fl6);
1568         if (dst == NULL)
1569                 return;
1570
1571         dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1572         if (IS_ERR(dst))
1573                 return;
1574
1575         rt = (struct rt6_info *) dst;
1576
1577         if (rt->rt6i_flags & RTF_GATEWAY) {
1578                 ND_PRINTK2(KERN_WARNING
1579                            "ICMPv6 Redirect: destination is not a neighbour.\n");
1580                 goto release;
1581         }
1582         if (!rt->rt6i_peer)
1583                 rt6_bind_peer(rt, 1);
1584         if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
1585                 goto release;
1586
1587         if (dev->addr_len) {
1588                 read_lock_bh(&neigh->lock);
1589                 if (neigh->nud_state & NUD_VALID) {
1590                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1591                         read_unlock_bh(&neigh->lock);
1592                         ha = ha_buf;
1593                         len += ndisc_opt_addr_space(dev);
1594                 } else
1595                         read_unlock_bh(&neigh->lock);
1596         }
1597
1598         rd_len = min_t(unsigned int,
1599                      IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1600         rd_len &= ~0x7;
1601         len += rd_len;
1602
1603         buff = sock_alloc_send_skb(sk,
1604                                    (MAX_HEADER + sizeof(struct ipv6hdr) +
1605                                     len + LL_ALLOCATED_SPACE(dev)),
1606                                    1, &err);
1607         if (buff == NULL) {
1608                 ND_PRINTK0(KERN_ERR
1609                            "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1610                            __func__, err);
1611                 goto release;
1612         }
1613
1614         skb_reserve(buff, LL_RESERVED_SPACE(dev));
1615         ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1616                    IPPROTO_ICMPV6, len);
1617
1618         skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1619         skb_put(buff, len);
1620         icmph = icmp6_hdr(buff);
1621
1622         memset(icmph, 0, sizeof(struct icmp6hdr));
1623         icmph->icmp6_type = NDISC_REDIRECT;
1624
1625         /*
1626          *      copy target and destination addresses
1627          */
1628
1629         addrp = (struct in6_addr *)(icmph + 1);
1630         ipv6_addr_copy(addrp, target);
1631         addrp++;
1632         ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1633
1634         opt = (u8*) (addrp + 1);
1635
1636         /*
1637          *      include target_address option
1638          */
1639
1640         if (ha)
1641                 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1642                                              dev->addr_len, dev->type);
1643
1644         /*
1645          *      build redirect option and copy skb over to the new packet.
1646          */
1647
1648         memset(opt, 0, 8);
1649         *(opt++) = ND_OPT_REDIRECT_HDR;
1650         *(opt++) = (rd_len >> 3);
1651         opt += 6;
1652
1653         memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1654
1655         icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1656                                              len, IPPROTO_ICMPV6,
1657                                              csum_partial(icmph, len, 0));
1658
1659         skb_dst_set(buff, dst);
1660         idev = in6_dev_get(dst->dev);
1661         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1662         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1663                       dst_output);
1664         if (!err) {
1665                 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1666                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1667         }
1668
1669         if (likely(idev != NULL))
1670                 in6_dev_put(idev);
1671         return;
1672
1673 release:
1674         dst_release(dst);
1675 }
1676
1677 static void pndisc_redo(struct sk_buff *skb)
1678 {
1679         ndisc_recv_ns(skb);
1680         kfree_skb(skb);
1681 }
1682
1683 int ndisc_rcv(struct sk_buff *skb)
1684 {
1685         struct nd_msg *msg;
1686
1687         if (!pskb_may_pull(skb, skb->len))
1688                 return 0;
1689
1690         msg = (struct nd_msg *)skb_transport_header(skb);
1691
1692         __skb_push(skb, skb->data - skb_transport_header(skb));
1693
1694         if (ipv6_hdr(skb)->hop_limit != 255) {
1695                 ND_PRINTK2(KERN_WARNING
1696                            "ICMPv6 NDISC: invalid hop-limit: %d\n",
1697                            ipv6_hdr(skb)->hop_limit);
1698                 return 0;
1699         }
1700
1701         if (msg->icmph.icmp6_code != 0) {
1702                 ND_PRINTK2(KERN_WARNING
1703                            "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1704                            msg->icmph.icmp6_code);
1705                 return 0;
1706         }
1707
1708         memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1709
1710         switch (msg->icmph.icmp6_type) {
1711         case NDISC_NEIGHBOUR_SOLICITATION:
1712                 ndisc_recv_ns(skb);
1713                 break;
1714
1715         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1716                 ndisc_recv_na(skb);
1717                 break;
1718
1719         case NDISC_ROUTER_SOLICITATION:
1720                 ndisc_recv_rs(skb);
1721                 break;
1722
1723         case NDISC_ROUTER_ADVERTISEMENT:
1724                 ndisc_router_discovery(skb);
1725                 break;
1726
1727         case NDISC_REDIRECT:
1728                 ndisc_redirect_rcv(skb);
1729                 break;
1730         }
1731
1732         return 0;
1733 }
1734
1735 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1736 {
1737         struct net_device *dev = ptr;
1738         struct net *net = dev_net(dev);
1739
1740         switch (event) {
1741         case NETDEV_CHANGEADDR:
1742                 neigh_changeaddr(&nd_tbl, dev);
1743                 fib6_run_gc(~0UL, net);
1744                 break;
1745         case NETDEV_DOWN:
1746                 neigh_ifdown(&nd_tbl, dev);
1747                 fib6_run_gc(~0UL, net);
1748                 break;
1749         case NETDEV_NOTIFY_PEERS:
1750         case NETDEV_BONDING_FAILOVER:
1751                 ndisc_send_unsol_na(dev);
1752                 break;
1753         default:
1754                 break;
1755         }
1756
1757         return NOTIFY_DONE;
1758 }
1759
1760 static struct notifier_block ndisc_netdev_notifier = {
1761         .notifier_call = ndisc_netdev_event,
1762 };
1763
1764 #ifdef CONFIG_SYSCTL
1765 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1766                                          const char *func, const char *dev_name)
1767 {
1768         static char warncomm[TASK_COMM_LEN];
1769         static int warned;
1770         if (strcmp(warncomm, current->comm) && warned < 5) {
1771                 strcpy(warncomm, current->comm);
1772                 printk(KERN_WARNING
1773                         "process `%s' is using deprecated sysctl (%s) "
1774                         "net.ipv6.neigh.%s.%s; "
1775                         "Use net.ipv6.neigh.%s.%s_ms "
1776                         "instead.\n",
1777                         warncomm, func,
1778                         dev_name, ctl->procname,
1779                         dev_name, ctl->procname);
1780                 warned++;
1781         }
1782 }
1783
1784 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1785 {
1786         struct net_device *dev = ctl->extra1;
1787         struct inet6_dev *idev;
1788         int ret;
1789
1790         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1791             (strcmp(ctl->procname, "base_reachable_time") == 0))
1792                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1793
1794         if (strcmp(ctl->procname, "retrans_time") == 0)
1795                 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1796
1797         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1798                 ret = proc_dointvec_jiffies(ctl, write,
1799                                             buffer, lenp, ppos);
1800
1801         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1802                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1803                 ret = proc_dointvec_ms_jiffies(ctl, write,
1804                                                buffer, lenp, ppos);
1805         else
1806                 ret = -1;
1807
1808         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1809                 if (ctl->data == &idev->nd_parms->base_reachable_time)
1810                         idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1811                 idev->tstamp = jiffies;
1812                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1813                 in6_dev_put(idev);
1814         }
1815         return ret;
1816 }
1817
1818
1819 #endif
1820
1821 static int __net_init ndisc_net_init(struct net *net)
1822 {
1823         struct ipv6_pinfo *np;
1824         struct sock *sk;
1825         int err;
1826
1827         err = inet_ctl_sock_create(&sk, PF_INET6,
1828                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1829         if (err < 0) {
1830                 ND_PRINTK0(KERN_ERR
1831                            "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1832                            err);
1833                 return err;
1834         }
1835
1836         net->ipv6.ndisc_sk = sk;
1837
1838         np = inet6_sk(sk);
1839         np->hop_limit = 255;
1840         /* Do not loopback ndisc messages */
1841         np->mc_loop = 0;
1842
1843         return 0;
1844 }
1845
1846 static void __net_exit ndisc_net_exit(struct net *net)
1847 {
1848         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1849 }
1850
1851 static struct pernet_operations ndisc_net_ops = {
1852         .init = ndisc_net_init,
1853         .exit = ndisc_net_exit,
1854 };
1855
1856 int __init ndisc_init(void)
1857 {
1858         int err;
1859
1860         err = register_pernet_subsys(&ndisc_net_ops);
1861         if (err)
1862                 return err;
1863         /*
1864          * Initialize the neighbour table
1865          */
1866         neigh_table_init(&nd_tbl);
1867
1868 #ifdef CONFIG_SYSCTL
1869         err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6",
1870                                     &ndisc_ifinfo_sysctl_change);
1871         if (err)
1872                 goto out_unregister_pernet;
1873 #endif
1874         err = register_netdevice_notifier(&ndisc_netdev_notifier);
1875         if (err)
1876                 goto out_unregister_sysctl;
1877 out:
1878         return err;
1879
1880 out_unregister_sysctl:
1881 #ifdef CONFIG_SYSCTL
1882         neigh_sysctl_unregister(&nd_tbl.parms);
1883 out_unregister_pernet:
1884 #endif
1885         unregister_pernet_subsys(&ndisc_net_ops);
1886         goto out;
1887 }
1888
1889 void ndisc_cleanup(void)
1890 {
1891         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1892 #ifdef CONFIG_SYSCTL
1893         neigh_sysctl_unregister(&nd_tbl.parms);
1894 #endif
1895         neigh_table_clear(&nd_tbl);
1896         unregister_pernet_subsys(&ndisc_net_ops);
1897 }