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Linux/net/ipv6/ndisc.c

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  *      Neighbour Discovery for IPv6
  4  *      Linux INET6 implementation
  5  *
  6  *      Authors:
  7  *      Pedro Roque             <roque@di.fc.ul.pt>
  8  *      Mike Shaver             <shaver@ingenia.com>
  9  */
 10 
 11 /*
 12  *      Changes:
 13  *
 14  *      Alexey I. Froloff               :       RFC6106 (DNSSL) support
 15  *      Pierre Ynard                    :       export userland ND options
 16  *                                              through netlink (RDNSS support)
 17  *      Lars Fenneberg                  :       fixed MTU setting on receipt
 18  *                                              of an RA.
 19  *      Janos Farkas                    :       kmalloc failure checks
 20  *      Alexey Kuznetsov                :       state machine reworked
 21  *                                              and moved to net/core.
 22  *      Pekka Savola                    :       RFC2461 validation
 23  *      YOSHIFUJI Hideaki @USAGI        :       Verify ND options properly
 24  */
 25 
 26 #define pr_fmt(fmt) "ICMPv6: " fmt
 27 
 28 #include <linux/module.h>
 29 #include <linux/errno.h>
 30 #include <linux/types.h>
 31 #include <linux/socket.h>
 32 #include <linux/sockios.h>
 33 #include <linux/sched.h>
 34 #include <linux/net.h>
 35 #include <linux/in6.h>
 36 #include <linux/route.h>
 37 #include <linux/init.h>
 38 #include <linux/rcupdate.h>
 39 #include <linux/slab.h>
 40 #ifdef CONFIG_SYSCTL
 41 #include <linux/sysctl.h>
 42 #endif
 43 
 44 #include <linux/if_addr.h>
 45 #include <linux/if_ether.h>
 46 #include <linux/if_arp.h>
 47 #include <linux/ipv6.h>
 48 #include <linux/icmpv6.h>
 49 #include <linux/jhash.h>
 50 
 51 #include <net/sock.h>
 52 #include <net/snmp.h>
 53 
 54 #include <net/ipv6.h>
 55 #include <net/protocol.h>
 56 #include <net/ndisc.h>
 57 #include <net/ip6_route.h>
 58 #include <net/addrconf.h>
 59 #include <net/icmp.h>
 60 
 61 #include <net/netlink.h>
 62 #include <linux/rtnetlink.h>
 63 
 64 #include <net/flow.h>
 65 #include <net/ip6_checksum.h>
 66 #include <net/inet_common.h>
 67 #include <linux/proc_fs.h>
 68 
 69 #include <linux/netfilter.h>
 70 #include <linux/netfilter_ipv6.h>
 71 
 72 static u32 ndisc_hash(const void *pkey,
 73                       const struct net_device *dev,
 74                       __u32 *hash_rnd);
 75 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
 76 static bool ndisc_allow_add(const struct net_device *dev,
 77                             struct netlink_ext_ack *extack);
 78 static int ndisc_constructor(struct neighbour *neigh);
 79 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
 80 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
 81 static int pndisc_constructor(struct pneigh_entry *n);
 82 static void pndisc_destructor(struct pneigh_entry *n);
 83 static void pndisc_redo(struct sk_buff *skb);
 84 static int ndisc_is_multicast(const void *pkey);
 85 
 86 static const struct neigh_ops ndisc_generic_ops = {
 87         .family =               AF_INET6,
 88         .solicit =              ndisc_solicit,
 89         .error_report =         ndisc_error_report,
 90         .output =               neigh_resolve_output,
 91         .connected_output =     neigh_connected_output,
 92 };
 93 
 94 static const struct neigh_ops ndisc_hh_ops = {
 95         .family =               AF_INET6,
 96         .solicit =              ndisc_solicit,
 97         .error_report =         ndisc_error_report,
 98         .output =               neigh_resolve_output,
 99         .connected_output =     neigh_resolve_output,
100 };
101 
102 
103 static const struct neigh_ops ndisc_direct_ops = {
104         .family =               AF_INET6,
105         .output =               neigh_direct_output,
106         .connected_output =     neigh_direct_output,
107 };
108 
109 struct neigh_table nd_tbl = {
110         .family =       AF_INET6,
111         .key_len =      sizeof(struct in6_addr),
112         .protocol =     cpu_to_be16(ETH_P_IPV6),
113         .hash =         ndisc_hash,
114         .key_eq =       ndisc_key_eq,
115         .constructor =  ndisc_constructor,
116         .pconstructor = pndisc_constructor,
117         .pdestructor =  pndisc_destructor,
118         .proxy_redo =   pndisc_redo,
119         .is_multicast = ndisc_is_multicast,
120         .allow_add  =   ndisc_allow_add,
121         .id =           "ndisc_cache",
122         .parms = {
123                 .tbl                    = &nd_tbl,
124                 .reachable_time         = ND_REACHABLE_TIME,
125                 .data = {
126                         [NEIGH_VAR_MCAST_PROBES] = 3,
127                         [NEIGH_VAR_UCAST_PROBES] = 3,
128                         [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
129                         [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
130                         [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
131                         [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
132                         [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
133                         [NEIGH_VAR_PROXY_QLEN] = 64,
134                         [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
135                         [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
136                 },
137         },
138         .gc_interval =    30 * HZ,
139         .gc_thresh1 =    128,
140         .gc_thresh2 =    512,
141         .gc_thresh3 =   1024,
142 };
143 EXPORT_SYMBOL_GPL(nd_tbl);
144 
145 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
146                               int data_len, int pad)
147 {
148         int space = __ndisc_opt_addr_space(data_len, pad);
149         u8 *opt = skb_put(skb, space);
150 
151         opt[0] = type;
152         opt[1] = space>>3;
153 
154         memset(opt + 2, 0, pad);
155         opt   += pad;
156         space -= pad;
157 
158         memcpy(opt+2, data, data_len);
159         data_len += 2;
160         opt += data_len;
161         space -= data_len;
162         if (space > 0)
163                 memset(opt, 0, space);
164 }
165 EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
166 
167 static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
168                                           void *data, u8 icmp6_type)
169 {
170         __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
171                                  ndisc_addr_option_pad(skb->dev->type));
172         ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
173 }
174 
175 static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
176                                                    void *ha,
177                                                    const u8 *ops_data)
178 {
179         ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
180         ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
181 }
182 
183 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
184                                             struct nd_opt_hdr *end)
185 {
186         int type;
187         if (!cur || !end || cur >= end)
188                 return NULL;
189         type = cur->nd_opt_type;
190         do {
191                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
192         } while (cur < end && cur->nd_opt_type != type);
193         return cur <= end && cur->nd_opt_type == type ? cur : NULL;
194 }
195 
196 static inline int ndisc_is_useropt(const struct net_device *dev,
197                                    struct nd_opt_hdr *opt)
198 {
199         return opt->nd_opt_type == ND_OPT_RDNSS ||
200                 opt->nd_opt_type == ND_OPT_DNSSL ||
201                 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
202                 opt->nd_opt_type == ND_OPT_PREF64 ||
203                 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
204 }
205 
206 static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
207                                              struct nd_opt_hdr *cur,
208                                              struct nd_opt_hdr *end)
209 {
210         if (!cur || !end || cur >= end)
211                 return NULL;
212         do {
213                 cur = ((void *)cur) + (cur->nd_opt_len << 3);
214         } while (cur < end && !ndisc_is_useropt(dev, cur));
215         return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
216 }
217 
218 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
219                                           u8 *opt, int opt_len,
220                                           struct ndisc_options *ndopts)
221 {
222         struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
223 
224         if (!nd_opt || opt_len < 0 || !ndopts)
225                 return NULL;
226         memset(ndopts, 0, sizeof(*ndopts));
227         while (opt_len) {
228                 int l;
229                 if (opt_len < sizeof(struct nd_opt_hdr))
230                         return NULL;
231                 l = nd_opt->nd_opt_len << 3;
232                 if (opt_len < l || l == 0)
233                         return NULL;
234                 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
235                         goto next_opt;
236                 switch (nd_opt->nd_opt_type) {
237                 case ND_OPT_SOURCE_LL_ADDR:
238                 case ND_OPT_TARGET_LL_ADDR:
239                 case ND_OPT_MTU:
240                 case ND_OPT_NONCE:
241                 case ND_OPT_REDIRECT_HDR:
242                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
243                                 ND_PRINTK(2, warn,
244                                           "%s: duplicated ND6 option found: type=%d\n",
245                                           __func__, nd_opt->nd_opt_type);
246                         } else {
247                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
248                         }
249                         break;
250                 case ND_OPT_PREFIX_INFO:
251                         ndopts->nd_opts_pi_end = nd_opt;
252                         if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
253                                 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
254                         break;
255 #ifdef CONFIG_IPV6_ROUTE_INFO
256                 case ND_OPT_ROUTE_INFO:
257                         ndopts->nd_opts_ri_end = nd_opt;
258                         if (!ndopts->nd_opts_ri)
259                                 ndopts->nd_opts_ri = nd_opt;
260                         break;
261 #endif
262                 default:
263                         if (ndisc_is_useropt(dev, nd_opt)) {
264                                 ndopts->nd_useropts_end = nd_opt;
265                                 if (!ndopts->nd_useropts)
266                                         ndopts->nd_useropts = nd_opt;
267                         } else {
268                                 /*
269                                  * Unknown options must be silently ignored,
270                                  * to accommodate future extension to the
271                                  * protocol.
272                                  */
273                                 ND_PRINTK(2, notice,
274                                           "%s: ignored unsupported option; type=%d, len=%d\n",
275                                           __func__,
276                                           nd_opt->nd_opt_type,
277                                           nd_opt->nd_opt_len);
278                         }
279                 }
280 next_opt:
281                 opt_len -= l;
282                 nd_opt = ((void *)nd_opt) + l;
283         }
284         return ndopts;
285 }
286 
287 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
288 {
289         switch (dev->type) {
290         case ARPHRD_ETHER:
291         case ARPHRD_IEEE802:    /* Not sure. Check it later. --ANK */
292         case ARPHRD_FDDI:
293                 ipv6_eth_mc_map(addr, buf);
294                 return 0;
295         case ARPHRD_ARCNET:
296                 ipv6_arcnet_mc_map(addr, buf);
297                 return 0;
298         case ARPHRD_INFINIBAND:
299                 ipv6_ib_mc_map(addr, dev->broadcast, buf);
300                 return 0;
301         case ARPHRD_IPGRE:
302                 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
303         default:
304                 if (dir) {
305                         memcpy(buf, dev->broadcast, dev->addr_len);
306                         return 0;
307                 }
308         }
309         return -EINVAL;
310 }
311 EXPORT_SYMBOL(ndisc_mc_map);
312 
313 static u32 ndisc_hash(const void *pkey,
314                       const struct net_device *dev,
315                       __u32 *hash_rnd)
316 {
317         return ndisc_hashfn(pkey, dev, hash_rnd);
318 }
319 
320 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
321 {
322         return neigh_key_eq128(n, pkey);
323 }
324 
325 static int ndisc_constructor(struct neighbour *neigh)
326 {
327         struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
328         struct net_device *dev = neigh->dev;
329         struct inet6_dev *in6_dev;
330         struct neigh_parms *parms;
331         bool is_multicast = ipv6_addr_is_multicast(addr);
332 
333         in6_dev = in6_dev_get(dev);
334         if (!in6_dev) {
335                 return -EINVAL;
336         }
337 
338         parms = in6_dev->nd_parms;
339         __neigh_parms_put(neigh->parms);
340         neigh->parms = neigh_parms_clone(parms);
341 
342         neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
343         if (!dev->header_ops) {
344                 neigh->nud_state = NUD_NOARP;
345                 neigh->ops = &ndisc_direct_ops;
346                 neigh->output = neigh_direct_output;
347         } else {
348                 if (is_multicast) {
349                         neigh->nud_state = NUD_NOARP;
350                         ndisc_mc_map(addr, neigh->ha, dev, 1);
351                 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
352                         neigh->nud_state = NUD_NOARP;
353                         memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
354                         if (dev->flags&IFF_LOOPBACK)
355                                 neigh->type = RTN_LOCAL;
356                 } else if (dev->flags&IFF_POINTOPOINT) {
357                         neigh->nud_state = NUD_NOARP;
358                         memcpy(neigh->ha, dev->broadcast, dev->addr_len);
359                 }
360                 if (dev->header_ops->cache)
361                         neigh->ops = &ndisc_hh_ops;
362                 else
363                         neigh->ops = &ndisc_generic_ops;
364                 if (neigh->nud_state&NUD_VALID)
365                         neigh->output = neigh->ops->connected_output;
366                 else
367                         neigh->output = neigh->ops->output;
368         }
369         in6_dev_put(in6_dev);
370         return 0;
371 }
372 
373 static int pndisc_constructor(struct pneigh_entry *n)
374 {
375         struct in6_addr *addr = (struct in6_addr *)&n->key;
376         struct in6_addr maddr;
377         struct net_device *dev = n->dev;
378 
379         if (!dev || !__in6_dev_get(dev))
380                 return -EINVAL;
381         addrconf_addr_solict_mult(addr, &maddr);
382         ipv6_dev_mc_inc(dev, &maddr);
383         return 0;
384 }
385 
386 static void pndisc_destructor(struct pneigh_entry *n)
387 {
388         struct in6_addr *addr = (struct in6_addr *)&n->key;
389         struct in6_addr maddr;
390         struct net_device *dev = n->dev;
391 
392         if (!dev || !__in6_dev_get(dev))
393                 return;
394         addrconf_addr_solict_mult(addr, &maddr);
395         ipv6_dev_mc_dec(dev, &maddr);
396 }
397 
398 /* called with rtnl held */
399 static bool ndisc_allow_add(const struct net_device *dev,
400                             struct netlink_ext_ack *extack)
401 {
402         struct inet6_dev *idev = __in6_dev_get(dev);
403 
404         if (!idev || idev->cnf.disable_ipv6) {
405                 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
406                 return false;
407         }
408 
409         return true;
410 }
411 
412 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
413                                        int len)
414 {
415         int hlen = LL_RESERVED_SPACE(dev);
416         int tlen = dev->needed_tailroom;
417         struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
418         struct sk_buff *skb;
419 
420         skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
421         if (!skb) {
422                 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
423                           __func__);
424                 return NULL;
425         }
426 
427         skb->protocol = htons(ETH_P_IPV6);
428         skb->dev = dev;
429 
430         skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
431         skb_reset_transport_header(skb);
432 
433         /* Manually assign socket ownership as we avoid calling
434          * sock_alloc_send_pskb() to bypass wmem buffer limits
435          */
436         skb_set_owner_w(skb, sk);
437 
438         return skb;
439 }
440 
441 static void ip6_nd_hdr(struct sk_buff *skb,
442                        const struct in6_addr *saddr,
443                        const struct in6_addr *daddr,
444                        int hop_limit, int len)
445 {
446         struct ipv6hdr *hdr;
447         struct inet6_dev *idev;
448         unsigned tclass;
449 
450         rcu_read_lock();
451         idev = __in6_dev_get(skb->dev);
452         tclass = idev ? idev->cnf.ndisc_tclass : 0;
453         rcu_read_unlock();
454 
455         skb_push(skb, sizeof(*hdr));
456         skb_reset_network_header(skb);
457         hdr = ipv6_hdr(skb);
458 
459         ip6_flow_hdr(hdr, tclass, 0);
460 
461         hdr->payload_len = htons(len);
462         hdr->nexthdr = IPPROTO_ICMPV6;
463         hdr->hop_limit = hop_limit;
464 
465         hdr->saddr = *saddr;
466         hdr->daddr = *daddr;
467 }
468 
469 static void ndisc_send_skb(struct sk_buff *skb,
470                            const struct in6_addr *daddr,
471                            const struct in6_addr *saddr)
472 {
473         struct dst_entry *dst = skb_dst(skb);
474         struct net *net = dev_net(skb->dev);
475         struct sock *sk = net->ipv6.ndisc_sk;
476         struct inet6_dev *idev;
477         int err;
478         struct icmp6hdr *icmp6h = icmp6_hdr(skb);
479         u8 type;
480 
481         type = icmp6h->icmp6_type;
482 
483         if (!dst) {
484                 struct flowi6 fl6;
485                 int oif = skb->dev->ifindex;
486 
487                 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
488                 dst = icmp6_dst_alloc(skb->dev, &fl6);
489                 if (IS_ERR(dst)) {
490                         kfree_skb(skb);
491                         return;
492                 }
493 
494                 skb_dst_set(skb, dst);
495         }
496 
497         icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
498                                               IPPROTO_ICMPV6,
499                                               csum_partial(icmp6h,
500                                                            skb->len, 0));
501 
502         ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
503 
504         rcu_read_lock();
505         idev = __in6_dev_get(dst->dev);
506         IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
507 
508         err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
509                       net, sk, skb, NULL, dst->dev,
510                       dst_output);
511         if (!err) {
512                 ICMP6MSGOUT_INC_STATS(net, idev, type);
513                 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
514         }
515 
516         rcu_read_unlock();
517 }
518 
519 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
520                    const struct in6_addr *solicited_addr,
521                    bool router, bool solicited, bool override, bool inc_opt)
522 {
523         struct sk_buff *skb;
524         struct in6_addr tmpaddr;
525         struct inet6_ifaddr *ifp;
526         const struct in6_addr *src_addr;
527         struct nd_msg *msg;
528         int optlen = 0;
529 
530         /* for anycast or proxy, solicited_addr != src_addr */
531         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
532         if (ifp) {
533                 src_addr = solicited_addr;
534                 if (ifp->flags & IFA_F_OPTIMISTIC)
535                         override = false;
536                 inc_opt |= ifp->idev->cnf.force_tllao;
537                 in6_ifa_put(ifp);
538         } else {
539                 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
540                                        inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
541                                        &tmpaddr))
542                         return;
543                 src_addr = &tmpaddr;
544         }
545 
546         if (!dev->addr_len)
547                 inc_opt = false;
548         if (inc_opt)
549                 optlen += ndisc_opt_addr_space(dev,
550                                                NDISC_NEIGHBOUR_ADVERTISEMENT);
551 
552         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
553         if (!skb)
554                 return;
555 
556         msg = skb_put(skb, sizeof(*msg));
557         *msg = (struct nd_msg) {
558                 .icmph = {
559                         .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
560                         .icmp6_router = router,
561                         .icmp6_solicited = solicited,
562                         .icmp6_override = override,
563                 },
564                 .target = *solicited_addr,
565         };
566 
567         if (inc_opt)
568                 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
569                                        dev->dev_addr,
570                                        NDISC_NEIGHBOUR_ADVERTISEMENT);
571 
572         ndisc_send_skb(skb, daddr, src_addr);
573 }
574 
575 static void ndisc_send_unsol_na(struct net_device *dev)
576 {
577         struct inet6_dev *idev;
578         struct inet6_ifaddr *ifa;
579 
580         idev = in6_dev_get(dev);
581         if (!idev)
582                 return;
583 
584         read_lock_bh(&idev->lock);
585         list_for_each_entry(ifa, &idev->addr_list, if_list) {
586                 /* skip tentative addresses until dad completes */
587                 if (ifa->flags & IFA_F_TENTATIVE &&
588                     !(ifa->flags & IFA_F_OPTIMISTIC))
589                         continue;
590 
591                 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
592                               /*router=*/ !!idev->cnf.forwarding,
593                               /*solicited=*/ false, /*override=*/ true,
594                               /*inc_opt=*/ true);
595         }
596         read_unlock_bh(&idev->lock);
597 
598         in6_dev_put(idev);
599 }
600 
601 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
602                    const struct in6_addr *daddr, const struct in6_addr *saddr,
603                    u64 nonce)
604 {
605         struct sk_buff *skb;
606         struct in6_addr addr_buf;
607         int inc_opt = dev->addr_len;
608         int optlen = 0;
609         struct nd_msg *msg;
610 
611         if (!saddr) {
612                 if (ipv6_get_lladdr(dev, &addr_buf,
613                                    (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
614                         return;
615                 saddr = &addr_buf;
616         }
617 
618         if (ipv6_addr_any(saddr))
619                 inc_opt = false;
620         if (inc_opt)
621                 optlen += ndisc_opt_addr_space(dev,
622                                                NDISC_NEIGHBOUR_SOLICITATION);
623         if (nonce != 0)
624                 optlen += 8;
625 
626         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
627         if (!skb)
628                 return;
629 
630         msg = skb_put(skb, sizeof(*msg));
631         *msg = (struct nd_msg) {
632                 .icmph = {
633                         .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
634                 },
635                 .target = *solicit,
636         };
637 
638         if (inc_opt)
639                 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
640                                        dev->dev_addr,
641                                        NDISC_NEIGHBOUR_SOLICITATION);
642         if (nonce != 0) {
643                 u8 *opt = skb_put(skb, 8);
644 
645                 opt[0] = ND_OPT_NONCE;
646                 opt[1] = 8 >> 3;
647                 memcpy(opt + 2, &nonce, 6);
648         }
649 
650         ndisc_send_skb(skb, daddr, saddr);
651 }
652 
653 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
654                    const struct in6_addr *daddr)
655 {
656         struct sk_buff *skb;
657         struct rs_msg *msg;
658         int send_sllao = dev->addr_len;
659         int optlen = 0;
660 
661 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
662         /*
663          * According to section 2.2 of RFC 4429, we must not
664          * send router solicitations with a sllao from
665          * optimistic addresses, but we may send the solicitation
666          * if we don't include the sllao.  So here we check
667          * if our address is optimistic, and if so, we
668          * suppress the inclusion of the sllao.
669          */
670         if (send_sllao) {
671                 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
672                                                            dev, 1);
673                 if (ifp) {
674                         if (ifp->flags & IFA_F_OPTIMISTIC)  {
675                                 send_sllao = 0;
676                         }
677                         in6_ifa_put(ifp);
678                 } else {
679                         send_sllao = 0;
680                 }
681         }
682 #endif
683         if (send_sllao)
684                 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
685 
686         skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
687         if (!skb)
688                 return;
689 
690         msg = skb_put(skb, sizeof(*msg));
691         *msg = (struct rs_msg) {
692                 .icmph = {
693                         .icmp6_type = NDISC_ROUTER_SOLICITATION,
694                 },
695         };
696 
697         if (send_sllao)
698                 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
699                                        dev->dev_addr,
700                                        NDISC_ROUTER_SOLICITATION);
701 
702         ndisc_send_skb(skb, daddr, saddr);
703 }
704 
705 
706 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
707 {
708         /*
709          *      "The sender MUST return an ICMP
710          *       destination unreachable"
711          */
712         dst_link_failure(skb);
713         kfree_skb(skb);
714 }
715 
716 /* Called with locked neigh: either read or both */
717 
718 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
719 {
720         struct in6_addr *saddr = NULL;
721         struct in6_addr mcaddr;
722         struct net_device *dev = neigh->dev;
723         struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
724         int probes = atomic_read(&neigh->probes);
725 
726         if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
727                                            dev, false, 1,
728                                            IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
729                 saddr = &ipv6_hdr(skb)->saddr;
730         probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
731         if (probes < 0) {
732                 if (!(neigh->nud_state & NUD_VALID)) {
733                         ND_PRINTK(1, dbg,
734                                   "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
735                                   __func__, target);
736                 }
737                 ndisc_send_ns(dev, target, target, saddr, 0);
738         } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
739                 neigh_app_ns(neigh);
740         } else {
741                 addrconf_addr_solict_mult(target, &mcaddr);
742                 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
743         }
744 }
745 
746 static int pndisc_is_router(const void *pkey,
747                             struct net_device *dev)
748 {
749         struct pneigh_entry *n;
750         int ret = -1;
751 
752         read_lock_bh(&nd_tbl.lock);
753         n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
754         if (n)
755                 ret = !!(n->flags & NTF_ROUTER);
756         read_unlock_bh(&nd_tbl.lock);
757 
758         return ret;
759 }
760 
761 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
762                   const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
763                   struct ndisc_options *ndopts)
764 {
765         neigh_update(neigh, lladdr, new, flags, 0);
766         /* report ndisc ops about neighbour update */
767         ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
768 }
769 
770 static void ndisc_recv_ns(struct sk_buff *skb)
771 {
772         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
773         const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
774         const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
775         u8 *lladdr = NULL;
776         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
777                                     offsetof(struct nd_msg, opt));
778         struct ndisc_options ndopts;
779         struct net_device *dev = skb->dev;
780         struct inet6_ifaddr *ifp;
781         struct inet6_dev *idev = NULL;
782         struct neighbour *neigh;
783         int dad = ipv6_addr_any(saddr);
784         bool inc;
785         int is_router = -1;
786         u64 nonce = 0;
787 
788         if (skb->len < sizeof(struct nd_msg)) {
789                 ND_PRINTK(2, warn, "NS: packet too short\n");
790                 return;
791         }
792 
793         if (ipv6_addr_is_multicast(&msg->target)) {
794                 ND_PRINTK(2, warn, "NS: multicast target address\n");
795                 return;
796         }
797 
798         /*
799          * RFC2461 7.1.1:
800          * DAD has to be destined for solicited node multicast address.
801          */
802         if (dad && !ipv6_addr_is_solict_mult(daddr)) {
803                 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
804                 return;
805         }
806 
807         if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
808                 ND_PRINTK(2, warn, "NS: invalid ND options\n");
809                 return;
810         }
811 
812         if (ndopts.nd_opts_src_lladdr) {
813                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
814                 if (!lladdr) {
815                         ND_PRINTK(2, warn,
816                                   "NS: invalid link-layer address length\n");
817                         return;
818                 }
819 
820                 /* RFC2461 7.1.1:
821                  *      If the IP source address is the unspecified address,
822                  *      there MUST NOT be source link-layer address option
823                  *      in the message.
824                  */
825                 if (dad) {
826                         ND_PRINTK(2, warn,
827                                   "NS: bad DAD packet (link-layer address option)\n");
828                         return;
829                 }
830         }
831         if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
832                 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
833 
834         inc = ipv6_addr_is_multicast(daddr);
835 
836         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
837         if (ifp) {
838 have_ifp:
839                 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
840                         if (dad) {
841                                 if (nonce != 0 && ifp->dad_nonce == nonce) {
842                                         u8 *np = (u8 *)&nonce;
843                                         /* Matching nonce if looped back */
844                                         ND_PRINTK(2, notice,
845                                                   "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
846                                                   ifp->idev->dev->name,
847                                                   &ifp->addr, np);
848                                         goto out;
849                                 }
850                                 /*
851                                  * We are colliding with another node
852                                  * who is doing DAD
853                                  * so fail our DAD process
854                                  */
855                                 addrconf_dad_failure(skb, ifp);
856                                 return;
857                         } else {
858                                 /*
859                                  * This is not a dad solicitation.
860                                  * If we are an optimistic node,
861                                  * we should respond.
862                                  * Otherwise, we should ignore it.
863                                  */
864                                 if (!(ifp->flags & IFA_F_OPTIMISTIC))
865                                         goto out;
866                         }
867                 }
868 
869                 idev = ifp->idev;
870         } else {
871                 struct net *net = dev_net(dev);
872 
873                 /* perhaps an address on the master device */
874                 if (netif_is_l3_slave(dev)) {
875                         struct net_device *mdev;
876 
877                         mdev = netdev_master_upper_dev_get_rcu(dev);
878                         if (mdev) {
879                                 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
880                                 if (ifp)
881                                         goto have_ifp;
882                         }
883                 }
884 
885                 idev = in6_dev_get(dev);
886                 if (!idev) {
887                         /* XXX: count this drop? */
888                         return;
889                 }
890 
891                 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
892                     (idev->cnf.forwarding &&
893                      (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
894                      (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
895                         if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
896                             skb->pkt_type != PACKET_HOST &&
897                             inc &&
898                             NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
899                                 /*
900                                  * for anycast or proxy,
901                                  * sender should delay its response
902                                  * by a random time between 0 and
903                                  * MAX_ANYCAST_DELAY_TIME seconds.
904                                  * (RFC2461) -- yoshfuji
905                                  */
906                                 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
907                                 if (n)
908                                         pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
909                                 goto out;
910                         }
911                 } else
912                         goto out;
913         }
914 
915         if (is_router < 0)
916                 is_router = idev->cnf.forwarding;
917 
918         if (dad) {
919                 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
920                               !!is_router, false, (ifp != NULL), true);
921                 goto out;
922         }
923 
924         if (inc)
925                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
926         else
927                 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
928 
929         /*
930          *      update / create cache entry
931          *      for the source address
932          */
933         neigh = __neigh_lookup(&nd_tbl, saddr, dev,
934                                !inc || lladdr || !dev->addr_len);
935         if (neigh)
936                 ndisc_update(dev, neigh, lladdr, NUD_STALE,
937                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
938                              NEIGH_UPDATE_F_OVERRIDE,
939                              NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
940         if (neigh || !dev->header_ops) {
941                 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
942                               true, (ifp != NULL && inc), inc);
943                 if (neigh)
944                         neigh_release(neigh);
945         }
946 
947 out:
948         if (ifp)
949                 in6_ifa_put(ifp);
950         else
951                 in6_dev_put(idev);
952 }
953 
954 static void ndisc_recv_na(struct sk_buff *skb)
955 {
956         struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
957         struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
958         const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
959         u8 *lladdr = NULL;
960         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
961                                     offsetof(struct nd_msg, opt));
962         struct ndisc_options ndopts;
963         struct net_device *dev = skb->dev;
964         struct inet6_dev *idev = __in6_dev_get(dev);
965         struct inet6_ifaddr *ifp;
966         struct neighbour *neigh;
967 
968         if (skb->len < sizeof(struct nd_msg)) {
969                 ND_PRINTK(2, warn, "NA: packet too short\n");
970                 return;
971         }
972 
973         if (ipv6_addr_is_multicast(&msg->target)) {
974                 ND_PRINTK(2, warn, "NA: target address is multicast\n");
975                 return;
976         }
977 
978         if (ipv6_addr_is_multicast(daddr) &&
979             msg->icmph.icmp6_solicited) {
980                 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
981                 return;
982         }
983 
984         /* For some 802.11 wireless deployments (and possibly other networks),
985          * there will be a NA proxy and unsolicitd packets are attacks
986          * and thus should not be accepted.
987          */
988         if (!msg->icmph.icmp6_solicited && idev &&
989             idev->cnf.drop_unsolicited_na)
990                 return;
991 
992         if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
993                 ND_PRINTK(2, warn, "NS: invalid ND option\n");
994                 return;
995         }
996         if (ndopts.nd_opts_tgt_lladdr) {
997                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
998                 if (!lladdr) {
999                         ND_PRINTK(2, warn,
1000                                   "NA: invalid link-layer address length\n");
1001                         return;
1002                 }
1003         }
1004         ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1005         if (ifp) {
1006                 if (skb->pkt_type != PACKET_LOOPBACK
1007                     && (ifp->flags & IFA_F_TENTATIVE)) {
1008                                 addrconf_dad_failure(skb, ifp);
1009                                 return;
1010                 }
1011                 /* What should we make now? The advertisement
1012                    is invalid, but ndisc specs say nothing
1013                    about it. It could be misconfiguration, or
1014                    an smart proxy agent tries to help us :-)
1015 
1016                    We should not print the error if NA has been
1017                    received from loopback - it is just our own
1018                    unsolicited advertisement.
1019                  */
1020                 if (skb->pkt_type != PACKET_LOOPBACK)
1021                         ND_PRINTK(1, warn,
1022                                   "NA: %pM advertised our address %pI6c on %s!\n",
1023                                   eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1024                 in6_ifa_put(ifp);
1025                 return;
1026         }
1027         neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1028 
1029         if (neigh) {
1030                 u8 old_flags = neigh->flags;
1031                 struct net *net = dev_net(dev);
1032 
1033                 if (neigh->nud_state & NUD_FAILED)
1034                         goto out;
1035 
1036                 /*
1037                  * Don't update the neighbor cache entry on a proxy NA from
1038                  * ourselves because either the proxied node is off link or it
1039                  * has already sent a NA to us.
1040                  */
1041                 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1042                     net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1043                     pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1044                         /* XXX: idev->cnf.proxy_ndp */
1045                         goto out;
1046                 }
1047 
1048                 ndisc_update(dev, neigh, lladdr,
1049                              msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1050                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1051                              (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1052                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1053                              (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1054                              NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1055 
1056                 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1057                         /*
1058                          * Change: router to host
1059                          */
1060                         rt6_clean_tohost(dev_net(dev),  saddr);
1061                 }
1062 
1063 out:
1064                 neigh_release(neigh);
1065         }
1066 }
1067 
1068 static void ndisc_recv_rs(struct sk_buff *skb)
1069 {
1070         struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1071         unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1072         struct neighbour *neigh;
1073         struct inet6_dev *idev;
1074         const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1075         struct ndisc_options ndopts;
1076         u8 *lladdr = NULL;
1077 
1078         if (skb->len < sizeof(*rs_msg))
1079                 return;
1080 
1081         idev = __in6_dev_get(skb->dev);
1082         if (!idev) {
1083                 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1084                 return;
1085         }
1086 
1087         /* Don't accept RS if we're not in router mode */
1088         if (!idev->cnf.forwarding)
1089                 goto out;
1090 
1091         /*
1092          * Don't update NCE if src = ::;
1093          * this implies that the source node has no ip address assigned yet.
1094          */
1095         if (ipv6_addr_any(saddr))
1096                 goto out;
1097 
1098         /* Parse ND options */
1099         if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1100                 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1101                 goto out;
1102         }
1103 
1104         if (ndopts.nd_opts_src_lladdr) {
1105                 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1106                                              skb->dev);
1107                 if (!lladdr)
1108                         goto out;
1109         }
1110 
1111         neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1112         if (neigh) {
1113                 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1114                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1115                              NEIGH_UPDATE_F_OVERRIDE|
1116                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1117                              NDISC_ROUTER_SOLICITATION, &ndopts);
1118                 neigh_release(neigh);
1119         }
1120 out:
1121         return;
1122 }
1123 
1124 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1125 {
1126         struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1127         struct sk_buff *skb;
1128         struct nlmsghdr *nlh;
1129         struct nduseroptmsg *ndmsg;
1130         struct net *net = dev_net(ra->dev);
1131         int err;
1132         int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1133                                     + (opt->nd_opt_len << 3));
1134         size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1135 
1136         skb = nlmsg_new(msg_size, GFP_ATOMIC);
1137         if (!skb) {
1138                 err = -ENOBUFS;
1139                 goto errout;
1140         }
1141 
1142         nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1143         if (!nlh) {
1144                 goto nla_put_failure;
1145         }
1146 
1147         ndmsg = nlmsg_data(nlh);
1148         ndmsg->nduseropt_family = AF_INET6;
1149         ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1150         ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1151         ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1152         ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1153 
1154         memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1155 
1156         if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1157                 goto nla_put_failure;
1158         nlmsg_end(skb, nlh);
1159 
1160         rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1161         return;
1162 
1163 nla_put_failure:
1164         nlmsg_free(skb);
1165         err = -EMSGSIZE;
1166 errout:
1167         rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1168 }
1169 
1170 static void ndisc_router_discovery(struct sk_buff *skb)
1171 {
1172         struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1173         struct neighbour *neigh = NULL;
1174         struct inet6_dev *in6_dev;
1175         struct fib6_info *rt = NULL;
1176         u32 defrtr_usr_metric;
1177         struct net *net;
1178         int lifetime;
1179         struct ndisc_options ndopts;
1180         int optlen;
1181         unsigned int pref = 0;
1182         __u32 old_if_flags;
1183         bool send_ifinfo_notify = false;
1184 
1185         __u8 *opt = (__u8 *)(ra_msg + 1);
1186 
1187         optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1188                 sizeof(struct ra_msg);
1189 
1190         ND_PRINTK(2, info,
1191                   "RA: %s, dev: %s\n",
1192                   __func__, skb->dev->name);
1193         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1194                 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1195                 return;
1196         }
1197         if (optlen < 0) {
1198                 ND_PRINTK(2, warn, "RA: packet too short\n");
1199                 return;
1200         }
1201 
1202 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1203         if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1204                 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1205                 return;
1206         }
1207 #endif
1208 
1209         /*
1210          *      set the RA_RECV flag in the interface
1211          */
1212 
1213         in6_dev = __in6_dev_get(skb->dev);
1214         if (!in6_dev) {
1215                 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1216                           skb->dev->name);
1217                 return;
1218         }
1219 
1220         if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1221                 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1222                 return;
1223         }
1224 
1225         if (!ipv6_accept_ra(in6_dev)) {
1226                 ND_PRINTK(2, info,
1227                           "RA: %s, did not accept ra for dev: %s\n",
1228                           __func__, skb->dev->name);
1229                 goto skip_linkparms;
1230         }
1231 
1232 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1233         /* skip link-specific parameters from interior routers */
1234         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1235                 ND_PRINTK(2, info,
1236                           "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1237                           __func__, skb->dev->name);
1238                 goto skip_linkparms;
1239         }
1240 #endif
1241 
1242         if (in6_dev->if_flags & IF_RS_SENT) {
1243                 /*
1244                  *      flag that an RA was received after an RS was sent
1245                  *      out on this interface.
1246                  */
1247                 in6_dev->if_flags |= IF_RA_RCVD;
1248         }
1249 
1250         /*
1251          * Remember the managed/otherconf flags from most recently
1252          * received RA message (RFC 2462) -- yoshfuji
1253          */
1254         old_if_flags = in6_dev->if_flags;
1255         in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1256                                 IF_RA_OTHERCONF)) |
1257                                 (ra_msg->icmph.icmp6_addrconf_managed ?
1258                                         IF_RA_MANAGED : 0) |
1259                                 (ra_msg->icmph.icmp6_addrconf_other ?
1260                                         IF_RA_OTHERCONF : 0);
1261 
1262         if (old_if_flags != in6_dev->if_flags)
1263                 send_ifinfo_notify = true;
1264 
1265         if (!in6_dev->cnf.accept_ra_defrtr) {
1266                 ND_PRINTK(2, info,
1267                           "RA: %s, defrtr is false for dev: %s\n",
1268                           __func__, skb->dev->name);
1269                 goto skip_defrtr;
1270         }
1271 
1272         /* Do not accept RA with source-addr found on local machine unless
1273          * accept_ra_from_local is set to true.
1274          */
1275         net = dev_net(in6_dev->dev);
1276         if (!in6_dev->cnf.accept_ra_from_local &&
1277             ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1278                 ND_PRINTK(2, info,
1279                           "RA from local address detected on dev: %s: default router ignored\n",
1280                           skb->dev->name);
1281                 goto skip_defrtr;
1282         }
1283 
1284         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1285 
1286 #ifdef CONFIG_IPV6_ROUTER_PREF
1287         pref = ra_msg->icmph.icmp6_router_pref;
1288         /* 10b is handled as if it were 00b (medium) */
1289         if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1290             !in6_dev->cnf.accept_ra_rtr_pref)
1291                 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1292 #endif
1293         /* routes added from RAs do not use nexthop objects */
1294         rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1295         if (rt) {
1296                 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1297                                          rt->fib6_nh->fib_nh_dev, NULL,
1298                                           &ipv6_hdr(skb)->saddr);
1299                 if (!neigh) {
1300                         ND_PRINTK(0, err,
1301                                   "RA: %s got default router without neighbour\n",
1302                                   __func__);
1303                         fib6_info_release(rt);
1304                         return;
1305                 }
1306         }
1307         /* Set default route metric as specified by user */
1308         defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1309         /* delete the route if lifetime is 0 or if metric needs change */
1310         if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1311                 ip6_del_rt(net, rt, false);
1312                 rt = NULL;
1313         }
1314 
1315         ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, metric: %d, for dev: %s\n",
1316                   rt, lifetime, defrtr_usr_metric, skb->dev->name);
1317         if (!rt && lifetime) {
1318                 ND_PRINTK(3, info, "RA: adding default router\n");
1319 
1320                 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1321                                          skb->dev, pref, defrtr_usr_metric);
1322                 if (!rt) {
1323                         ND_PRINTK(0, err,
1324                                   "RA: %s failed to add default route\n",
1325                                   __func__);
1326                         return;
1327                 }
1328 
1329                 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1330                                          rt->fib6_nh->fib_nh_dev, NULL,
1331                                           &ipv6_hdr(skb)->saddr);
1332                 if (!neigh) {
1333                         ND_PRINTK(0, err,
1334                                   "RA: %s got default router without neighbour\n",
1335                                   __func__);
1336                         fib6_info_release(rt);
1337                         return;
1338                 }
1339                 neigh->flags |= NTF_ROUTER;
1340         } else if (rt) {
1341                 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1342         }
1343 
1344         if (rt)
1345                 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1346         if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1347             ra_msg->icmph.icmp6_hop_limit) {
1348                 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1349                         in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1350                         fib6_metric_set(rt, RTAX_HOPLIMIT,
1351                                         ra_msg->icmph.icmp6_hop_limit);
1352                 } else {
1353                         ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1354                 }
1355         }
1356 
1357 skip_defrtr:
1358 
1359         /*
1360          *      Update Reachable Time and Retrans Timer
1361          */
1362 
1363         if (in6_dev->nd_parms) {
1364                 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1365 
1366                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1367                         rtime = (rtime*HZ)/1000;
1368                         if (rtime < HZ/100)
1369                                 rtime = HZ/100;
1370                         NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1371                         in6_dev->tstamp = jiffies;
1372                         send_ifinfo_notify = true;
1373                 }
1374 
1375                 rtime = ntohl(ra_msg->reachable_time);
1376                 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1377                         rtime = (rtime*HZ)/1000;
1378 
1379                         if (rtime < HZ/10)
1380                                 rtime = HZ/10;
1381 
1382                         if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1383                                 NEIGH_VAR_SET(in6_dev->nd_parms,
1384                                               BASE_REACHABLE_TIME, rtime);
1385                                 NEIGH_VAR_SET(in6_dev->nd_parms,
1386                                               GC_STALETIME, 3 * rtime);
1387                                 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1388                                 in6_dev->tstamp = jiffies;
1389                                 send_ifinfo_notify = true;
1390                         }
1391                 }
1392         }
1393 
1394 skip_linkparms:
1395 
1396         /*
1397          *      Process options.
1398          */
1399 
1400         if (!neigh)
1401                 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1402                                        skb->dev, 1);
1403         if (neigh) {
1404                 u8 *lladdr = NULL;
1405                 if (ndopts.nd_opts_src_lladdr) {
1406                         lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1407                                                      skb->dev);
1408                         if (!lladdr) {
1409                                 ND_PRINTK(2, warn,
1410                                           "RA: invalid link-layer address length\n");
1411                                 goto out;
1412                         }
1413                 }
1414                 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1415                              NEIGH_UPDATE_F_WEAK_OVERRIDE|
1416                              NEIGH_UPDATE_F_OVERRIDE|
1417                              NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1418                              NEIGH_UPDATE_F_ISROUTER,
1419                              NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1420         }
1421 
1422         if (!ipv6_accept_ra(in6_dev)) {
1423                 ND_PRINTK(2, info,
1424                           "RA: %s, accept_ra is false for dev: %s\n",
1425                           __func__, skb->dev->name);
1426                 goto out;
1427         }
1428 
1429 #ifdef CONFIG_IPV6_ROUTE_INFO
1430         if (!in6_dev->cnf.accept_ra_from_local &&
1431             ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1432                           in6_dev->dev, 0)) {
1433                 ND_PRINTK(2, info,
1434                           "RA from local address detected on dev: %s: router info ignored.\n",
1435                           skb->dev->name);
1436                 goto skip_routeinfo;
1437         }
1438 
1439         if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1440                 struct nd_opt_hdr *p;
1441                 for (p = ndopts.nd_opts_ri;
1442                      p;
1443                      p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1444                         struct route_info *ri = (struct route_info *)p;
1445 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1446                         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1447                             ri->prefix_len == 0)
1448                                 continue;
1449 #endif
1450                         if (ri->prefix_len == 0 &&
1451                             !in6_dev->cnf.accept_ra_defrtr)
1452                                 continue;
1453                         if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1454                                 continue;
1455                         if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1456                                 continue;
1457                         rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1458                                       &ipv6_hdr(skb)->saddr);
1459                 }
1460         }
1461 
1462 skip_routeinfo:
1463 #endif
1464 
1465 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1466         /* skip link-specific ndopts from interior routers */
1467         if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1468                 ND_PRINTK(2, info,
1469                           "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1470                           __func__, skb->dev->name);
1471                 goto out;
1472         }
1473 #endif
1474 
1475         if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1476                 struct nd_opt_hdr *p;
1477                 for (p = ndopts.nd_opts_pi;
1478                      p;
1479                      p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1480                         addrconf_prefix_rcv(skb->dev, (u8 *)p,
1481                                             (p->nd_opt_len) << 3,
1482                                             ndopts.nd_opts_src_lladdr != NULL);
1483                 }
1484         }
1485 
1486         if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1487                 __be32 n;
1488                 u32 mtu;
1489 
1490                 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1491                 mtu = ntohl(n);
1492 
1493                 if (in6_dev->ra_mtu != mtu) {
1494                         in6_dev->ra_mtu = mtu;
1495                         send_ifinfo_notify = true;
1496                 }
1497 
1498                 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1499                         ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1500                 } else if (in6_dev->cnf.mtu6 != mtu) {
1501                         in6_dev->cnf.mtu6 = mtu;
1502                         fib6_metric_set(rt, RTAX_MTU, mtu);
1503                         rt6_mtu_change(skb->dev, mtu);
1504                 }
1505         }
1506 
1507         if (ndopts.nd_useropts) {
1508                 struct nd_opt_hdr *p;
1509                 for (p = ndopts.nd_useropts;
1510                      p;
1511                      p = ndisc_next_useropt(skb->dev, p,
1512                                             ndopts.nd_useropts_end)) {
1513                         ndisc_ra_useropt(skb, p);
1514                 }
1515         }
1516 
1517         if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1518                 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1519         }
1520 out:
1521         /* Send a notify if RA changed managed/otherconf flags or
1522          * timer settings or ra_mtu value
1523          */
1524         if (send_ifinfo_notify)
1525                 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1526 
1527         fib6_info_release(rt);
1528         if (neigh)
1529                 neigh_release(neigh);
1530 }
1531 
1532 static void ndisc_redirect_rcv(struct sk_buff *skb)
1533 {
1534         u8 *hdr;
1535         struct ndisc_options ndopts;
1536         struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1537         u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1538                                     offsetof(struct rd_msg, opt));
1539 
1540 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1541         switch (skb->ndisc_nodetype) {
1542         case NDISC_NODETYPE_HOST:
1543         case NDISC_NODETYPE_NODEFAULT:
1544                 ND_PRINTK(2, warn,
1545                           "Redirect: from host or unauthorized router\n");
1546                 return;
1547         }
1548 #endif
1549 
1550         if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1551                 ND_PRINTK(2, warn,
1552                           "Redirect: source address is not link-local\n");
1553                 return;
1554         }
1555 
1556         if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1557                 return;
1558 
1559         if (!ndopts.nd_opts_rh) {
1560                 ip6_redirect_no_header(skb, dev_net(skb->dev),
1561                                         skb->dev->ifindex);
1562                 return;
1563         }
1564 
1565         hdr = (u8 *)ndopts.nd_opts_rh;
1566         hdr += 8;
1567         if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1568                 return;
1569 
1570         icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1571 }
1572 
1573 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1574                                            struct sk_buff *orig_skb,
1575                                            int rd_len)
1576 {
1577         u8 *opt = skb_put(skb, rd_len);
1578 
1579         memset(opt, 0, 8);
1580         *(opt++) = ND_OPT_REDIRECT_HDR;
1581         *(opt++) = (rd_len >> 3);
1582         opt += 6;
1583 
1584         skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1585                       rd_len - 8);
1586 }
1587 
1588 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1589 {
1590         struct net_device *dev = skb->dev;
1591         struct net *net = dev_net(dev);
1592         struct sock *sk = net->ipv6.ndisc_sk;
1593         int optlen = 0;
1594         struct inet_peer *peer;
1595         struct sk_buff *buff;
1596         struct rd_msg *msg;
1597         struct in6_addr saddr_buf;
1598         struct rt6_info *rt;
1599         struct dst_entry *dst;
1600         struct flowi6 fl6;
1601         int rd_len;
1602         u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1603            ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1604         bool ret;
1605 
1606         if (netif_is_l3_master(skb->dev)) {
1607                 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1608                 if (!dev)
1609                         return;
1610         }
1611 
1612         if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1613                 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1614                           dev->name);
1615                 return;
1616         }
1617 
1618         if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1619             ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1620                 ND_PRINTK(2, warn,
1621                           "Redirect: target address is not link-local unicast\n");
1622                 return;
1623         }
1624 
1625         icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1626                          &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1627 
1628         dst = ip6_route_output(net, NULL, &fl6);
1629         if (dst->error) {
1630                 dst_release(dst);
1631                 return;
1632         }
1633         dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1634         if (IS_ERR(dst))
1635                 return;
1636 
1637         rt = (struct rt6_info *) dst;
1638 
1639         if (rt->rt6i_flags & RTF_GATEWAY) {
1640                 ND_PRINTK(2, warn,
1641                           "Redirect: destination is not a neighbour\n");
1642                 goto release;
1643         }
1644         peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1645         ret = inet_peer_xrlim_allow(peer, 1*HZ);
1646         if (peer)
1647                 inet_putpeer(peer);
1648         if (!ret)
1649                 goto release;
1650 
1651         if (dev->addr_len) {
1652                 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1653                 if (!neigh) {
1654                         ND_PRINTK(2, warn,
1655                                   "Redirect: no neigh for target address\n");
1656                         goto release;
1657                 }
1658 
1659                 read_lock_bh(&neigh->lock);
1660                 if (neigh->nud_state & NUD_VALID) {
1661                         memcpy(ha_buf, neigh->ha, dev->addr_len);
1662                         read_unlock_bh(&neigh->lock);
1663                         ha = ha_buf;
1664                         optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1665                                                                 ops_data_buf,
1666                                                                 &ops_data);
1667                 } else
1668                         read_unlock_bh(&neigh->lock);
1669 
1670                 neigh_release(neigh);
1671         }
1672 
1673         rd_len = min_t(unsigned int,
1674                        IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1675                        skb->len + 8);
1676         rd_len &= ~0x7;
1677         optlen += rd_len;
1678 
1679         buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1680         if (!buff)
1681                 goto release;
1682 
1683         msg = skb_put(buff, sizeof(*msg));
1684         *msg = (struct rd_msg) {
1685                 .icmph = {
1686                         .icmp6_type = NDISC_REDIRECT,
1687                 },
1688                 .target = *target,
1689                 .dest = ipv6_hdr(skb)->daddr,
1690         };
1691 
1692         /*
1693          *      include target_address option
1694          */
1695 
1696         if (ha)
1697                 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1698 
1699         /*
1700          *      build redirect option and copy skb over to the new packet.
1701          */
1702 
1703         if (rd_len)
1704                 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1705 
1706         skb_dst_set(buff, dst);
1707         ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1708         return;
1709 
1710 release:
1711         dst_release(dst);
1712 }
1713 
1714 static void pndisc_redo(struct sk_buff *skb)
1715 {
1716         ndisc_recv_ns(skb);
1717         kfree_skb(skb);
1718 }
1719 
1720 static int ndisc_is_multicast(const void *pkey)
1721 {
1722         return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1723 }
1724 
1725 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1726 {
1727         struct inet6_dev *idev = __in6_dev_get(skb->dev);
1728 
1729         if (!idev)
1730                 return true;
1731         if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1732             idev->cnf.suppress_frag_ndisc) {
1733                 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1734                 return true;
1735         }
1736         return false;
1737 }
1738 
1739 int ndisc_rcv(struct sk_buff *skb)
1740 {
1741         struct nd_msg *msg;
1742 
1743         if (ndisc_suppress_frag_ndisc(skb))
1744                 return 0;
1745 
1746         if (skb_linearize(skb))
1747                 return 0;
1748 
1749         msg = (struct nd_msg *)skb_transport_header(skb);
1750 
1751         __skb_push(skb, skb->data - skb_transport_header(skb));
1752 
1753         if (ipv6_hdr(skb)->hop_limit != 255) {
1754                 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1755                           ipv6_hdr(skb)->hop_limit);
1756                 return 0;
1757         }
1758 
1759         if (msg->icmph.icmp6_code != 0) {
1760                 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1761                           msg->icmph.icmp6_code);
1762                 return 0;
1763         }
1764 
1765         switch (msg->icmph.icmp6_type) {
1766         case NDISC_NEIGHBOUR_SOLICITATION:
1767                 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1768                 ndisc_recv_ns(skb);
1769                 break;
1770 
1771         case NDISC_NEIGHBOUR_ADVERTISEMENT:
1772                 ndisc_recv_na(skb);
1773                 break;
1774 
1775         case NDISC_ROUTER_SOLICITATION:
1776                 ndisc_recv_rs(skb);
1777                 break;
1778 
1779         case NDISC_ROUTER_ADVERTISEMENT:
1780                 ndisc_router_discovery(skb);
1781                 break;
1782 
1783         case NDISC_REDIRECT:
1784                 ndisc_redirect_rcv(skb);
1785                 break;
1786         }
1787 
1788         return 0;
1789 }
1790 
1791 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1792 {
1793         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1794         struct netdev_notifier_change_info *change_info;
1795         struct net *net = dev_net(dev);
1796         struct inet6_dev *idev;
1797 
1798         switch (event) {
1799         case NETDEV_CHANGEADDR:
1800                 neigh_changeaddr(&nd_tbl, dev);
1801                 fib6_run_gc(0, net, false);
1802                 fallthrough;
1803         case NETDEV_UP:
1804                 idev = in6_dev_get(dev);
1805                 if (!idev)
1806                         break;
1807                 if (idev->cnf.ndisc_notify ||
1808                     net->ipv6.devconf_all->ndisc_notify)
1809                         ndisc_send_unsol_na(dev);
1810                 in6_dev_put(idev);
1811                 break;
1812         case NETDEV_CHANGE:
1813                 change_info = ptr;
1814                 if (change_info->flags_changed & IFF_NOARP)
1815                         neigh_changeaddr(&nd_tbl, dev);
1816                 if (!netif_carrier_ok(dev))
1817                         neigh_carrier_down(&nd_tbl, dev);
1818                 break;
1819         case NETDEV_DOWN:
1820                 neigh_ifdown(&nd_tbl, dev);
1821                 fib6_run_gc(0, net, false);
1822                 break;
1823         case NETDEV_NOTIFY_PEERS:
1824                 ndisc_send_unsol_na(dev);
1825                 break;
1826         default:
1827                 break;
1828         }
1829 
1830         return NOTIFY_DONE;
1831 }
1832 
1833 static struct notifier_block ndisc_netdev_notifier = {
1834         .notifier_call = ndisc_netdev_event,
1835         .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1836 };
1837 
1838 #ifdef CONFIG_SYSCTL
1839 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1840                                          const char *func, const char *dev_name)
1841 {
1842         static char warncomm[TASK_COMM_LEN];
1843         static int warned;
1844         if (strcmp(warncomm, current->comm) && warned < 5) {
1845                 strcpy(warncomm, current->comm);
1846                 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1847                         warncomm, func,
1848                         dev_name, ctl->procname,
1849                         dev_name, ctl->procname);
1850                 warned++;
1851         }
1852 }
1853 
1854 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1855                 size_t *lenp, loff_t *ppos)
1856 {
1857         struct net_device *dev = ctl->extra1;
1858         struct inet6_dev *idev;
1859         int ret;
1860 
1861         if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1862             (strcmp(ctl->procname, "base_reachable_time") == 0))
1863                 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1864 
1865         if (strcmp(ctl->procname, "retrans_time") == 0)
1866                 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1867 
1868         else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1869                 ret = neigh_proc_dointvec_jiffies(ctl, write,
1870                                                   buffer, lenp, ppos);
1871 
1872         else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1873                  (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1874                 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1875                                                      buffer, lenp, ppos);
1876         else
1877                 ret = -1;
1878 
1879         if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1880                 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1881                         idev->nd_parms->reachable_time =
1882                                         neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1883                 idev->tstamp = jiffies;
1884                 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1885                 in6_dev_put(idev);
1886         }
1887         return ret;
1888 }
1889 
1890 
1891 #endif
1892 
1893 static int __net_init ndisc_net_init(struct net *net)
1894 {
1895         struct ipv6_pinfo *np;
1896         struct sock *sk;
1897         int err;
1898 
1899         err = inet_ctl_sock_create(&sk, PF_INET6,
1900                                    SOCK_RAW, IPPROTO_ICMPV6, net);
1901         if (err < 0) {
1902                 ND_PRINTK(0, err,
1903                           "NDISC: Failed to initialize the control socket (err %d)\n",
1904                           err);
1905                 return err;
1906         }
1907 
1908         net->ipv6.ndisc_sk = sk;
1909 
1910         np = inet6_sk(sk);
1911         np->hop_limit = 255;
1912         /* Do not loopback ndisc messages */
1913         np->mc_loop = 0;
1914 
1915         return 0;
1916 }
1917 
1918 static void __net_exit ndisc_net_exit(struct net *net)
1919 {
1920         inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1921 }
1922 
1923 static struct pernet_operations ndisc_net_ops = {
1924         .init = ndisc_net_init,
1925         .exit = ndisc_net_exit,
1926 };
1927 
1928 int __init ndisc_init(void)
1929 {
1930         int err;
1931 
1932         err = register_pernet_subsys(&ndisc_net_ops);
1933         if (err)
1934                 return err;
1935         /*
1936          * Initialize the neighbour table
1937          */
1938         neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1939 
1940 #ifdef CONFIG_SYSCTL
1941         err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1942                                     ndisc_ifinfo_sysctl_change);
1943         if (err)
1944                 goto out_unregister_pernet;
1945 out:
1946 #endif
1947         return err;
1948 
1949 #ifdef CONFIG_SYSCTL
1950 out_unregister_pernet:
1951         unregister_pernet_subsys(&ndisc_net_ops);
1952         goto out;
1953 #endif
1954 }
1955 
1956 int __init ndisc_late_init(void)
1957 {
1958         return register_netdevice_notifier(&ndisc_netdev_notifier);
1959 }
1960 
1961 void ndisc_late_cleanup(void)
1962 {
1963         unregister_netdevice_notifier(&ndisc_netdev_notifier);
1964 }
1965 
1966 void ndisc_cleanup(void)
1967 {
1968 #ifdef CONFIG_SYSCTL
1969         neigh_sysctl_unregister(&nd_tbl.parms);
1970 #endif
1971         neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1972         unregister_pernet_subsys(&ndisc_net_ops);
1973 }
1974 

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