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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
72static u32 ndisc_hash(const void *pkey,
73 const struct net_device *dev,
74 __u32 *hash_rnd);
75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
76static bool ndisc_allow_add(const struct net_device *dev,
77 struct netlink_ext_ack *extack);
78static int ndisc_constructor(struct neighbour *neigh);
79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
81static int pndisc_constructor(struct pneigh_entry *n);
82static void pndisc_destructor(struct pneigh_entry *n);
83static void pndisc_redo(struct sk_buff *skb);
84static int ndisc_is_multicast(const void *pkey);
85
86static 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
94static 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
103static const struct neigh_ops ndisc_direct_ops = {
104 .family = AF_INET6,
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
107};
108
109struct 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_INTERVAL_PROBE_TIME_MS] = 5 * HZ,
132 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
133 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
134 [NEIGH_VAR_PROXY_QLEN] = 64,
135 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
136 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
137 },
138 },
139 .gc_interval = 30 * HZ,
140 .gc_thresh1 = 128,
141 .gc_thresh2 = 512,
142 .gc_thresh3 = 1024,
143};
144EXPORT_SYMBOL_GPL(nd_tbl);
145
146void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data,
147 int data_len, int pad)
148{
149 int space = __ndisc_opt_addr_space(data_len, pad);
150 u8 *opt = skb_put(skb, space);
151
152 opt[0] = type;
153 opt[1] = space>>3;
154
155 memset(opt + 2, 0, pad);
156 opt += pad;
157 space -= pad;
158
159 memcpy(opt+2, data, data_len);
160 data_len += 2;
161 opt += data_len;
162 space -= data_len;
163 if (space > 0)
164 memset(opt, 0, space);
165}
166EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
167
168static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
169 const void *data, u8 icmp6_type)
170{
171 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
172 ndisc_addr_option_pad(skb->dev->type));
173 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
174}
175
176static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
177 void *ha,
178 const u8 *ops_data)
179{
180 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
181 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
182}
183
184static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
185 struct nd_opt_hdr *end)
186{
187 int type;
188 if (!cur || !end || cur >= end)
189 return NULL;
190 type = cur->nd_opt_type;
191 do {
192 cur = ((void *)cur) + (cur->nd_opt_len << 3);
193 } while (cur < end && cur->nd_opt_type != type);
194 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
195}
196
197static inline int ndisc_is_useropt(const struct net_device *dev,
198 struct nd_opt_hdr *opt)
199{
200 return opt->nd_opt_type == ND_OPT_PREFIX_INFO ||
201 opt->nd_opt_type == ND_OPT_RDNSS ||
202 opt->nd_opt_type == ND_OPT_DNSSL ||
203 opt->nd_opt_type == ND_OPT_6CO ||
204 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
205 opt->nd_opt_type == ND_OPT_PREF64;
206}
207
208static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
209 struct nd_opt_hdr *cur,
210 struct nd_opt_hdr *end)
211{
212 if (!cur || !end || cur >= end)
213 return NULL;
214 do {
215 cur = ((void *)cur) + (cur->nd_opt_len << 3);
216 } while (cur < end && !ndisc_is_useropt(dev, cur));
217 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
218}
219
220struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
221 u8 *opt, int opt_len,
222 struct ndisc_options *ndopts)
223{
224 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
225
226 if (!nd_opt || opt_len < 0 || !ndopts)
227 return NULL;
228 memset(ndopts, 0, sizeof(*ndopts));
229 while (opt_len) {
230 bool unknown = false;
231 int l;
232 if (opt_len < sizeof(struct nd_opt_hdr))
233 return NULL;
234 l = nd_opt->nd_opt_len << 3;
235 if (opt_len < l || l == 0)
236 return NULL;
237 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
238 goto next_opt;
239 switch (nd_opt->nd_opt_type) {
240 case ND_OPT_SOURCE_LL_ADDR:
241 case ND_OPT_TARGET_LL_ADDR:
242 case ND_OPT_MTU:
243 case ND_OPT_NONCE:
244 case ND_OPT_REDIRECT_HDR:
245 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
246 ND_PRINTK(2, warn,
247 "%s: duplicated ND6 option found: type=%d\n",
248 __func__, nd_opt->nd_opt_type);
249 } else {
250 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
251 }
252 break;
253 case ND_OPT_PREFIX_INFO:
254 ndopts->nd_opts_pi_end = nd_opt;
255 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
256 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
257 break;
258#ifdef CONFIG_IPV6_ROUTE_INFO
259 case ND_OPT_ROUTE_INFO:
260 ndopts->nd_opts_ri_end = nd_opt;
261 if (!ndopts->nd_opts_ri)
262 ndopts->nd_opts_ri = nd_opt;
263 break;
264#endif
265 default:
266 unknown = true;
267 }
268 if (ndisc_is_useropt(dev, nd_opt)) {
269 ndopts->nd_useropts_end = nd_opt;
270 if (!ndopts->nd_useropts)
271 ndopts->nd_useropts = nd_opt;
272 } else if (unknown) {
273 /*
274 * Unknown options must be silently ignored,
275 * to accommodate future extension to the
276 * protocol.
277 */
278 ND_PRINTK(2, notice,
279 "%s: ignored unsupported option; type=%d, len=%d\n",
280 __func__,
281 nd_opt->nd_opt_type,
282 nd_opt->nd_opt_len);
283 }
284next_opt:
285 opt_len -= l;
286 nd_opt = ((void *)nd_opt) + l;
287 }
288 return ndopts;
289}
290
291int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
292{
293 switch (dev->type) {
294 case ARPHRD_ETHER:
295 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
296 case ARPHRD_FDDI:
297 ipv6_eth_mc_map(addr, buf);
298 return 0;
299 case ARPHRD_ARCNET:
300 ipv6_arcnet_mc_map(addr, buf);
301 return 0;
302 case ARPHRD_INFINIBAND:
303 ipv6_ib_mc_map(addr, dev->broadcast, buf);
304 return 0;
305 case ARPHRD_IPGRE:
306 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
307 default:
308 if (dir) {
309 memcpy(buf, dev->broadcast, dev->addr_len);
310 return 0;
311 }
312 }
313 return -EINVAL;
314}
315EXPORT_SYMBOL(ndisc_mc_map);
316
317static u32 ndisc_hash(const void *pkey,
318 const struct net_device *dev,
319 __u32 *hash_rnd)
320{
321 return ndisc_hashfn(pkey, dev, hash_rnd);
322}
323
324static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
325{
326 return neigh_key_eq128(n, pkey);
327}
328
329static int ndisc_constructor(struct neighbour *neigh)
330{
331 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
332 struct net_device *dev = neigh->dev;
333 struct inet6_dev *in6_dev;
334 struct neigh_parms *parms;
335 bool is_multicast = ipv6_addr_is_multicast(addr);
336
337 in6_dev = in6_dev_get(dev);
338 if (!in6_dev) {
339 return -EINVAL;
340 }
341
342 parms = in6_dev->nd_parms;
343 __neigh_parms_put(neigh->parms);
344 neigh->parms = neigh_parms_clone(parms);
345
346 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
347 if (!dev->header_ops) {
348 neigh->nud_state = NUD_NOARP;
349 neigh->ops = &ndisc_direct_ops;
350 neigh->output = neigh_direct_output;
351 } else {
352 if (is_multicast) {
353 neigh->nud_state = NUD_NOARP;
354 ndisc_mc_map(addr, neigh->ha, dev, 1);
355 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
356 neigh->nud_state = NUD_NOARP;
357 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
358 if (dev->flags&IFF_LOOPBACK)
359 neigh->type = RTN_LOCAL;
360 } else if (dev->flags&IFF_POINTOPOINT) {
361 neigh->nud_state = NUD_NOARP;
362 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
363 }
364 if (dev->header_ops->cache)
365 neigh->ops = &ndisc_hh_ops;
366 else
367 neigh->ops = &ndisc_generic_ops;
368 if (neigh->nud_state&NUD_VALID)
369 neigh->output = neigh->ops->connected_output;
370 else
371 neigh->output = neigh->ops->output;
372 }
373 in6_dev_put(in6_dev);
374 return 0;
375}
376
377static int pndisc_constructor(struct pneigh_entry *n)
378{
379 struct in6_addr *addr = (struct in6_addr *)&n->key;
380 struct in6_addr maddr;
381 struct net_device *dev = n->dev;
382
383 if (!dev || !__in6_dev_get(dev))
384 return -EINVAL;
385 addrconf_addr_solict_mult(addr, &maddr);
386 ipv6_dev_mc_inc(dev, &maddr);
387 return 0;
388}
389
390static void pndisc_destructor(struct pneigh_entry *n)
391{
392 struct in6_addr *addr = (struct in6_addr *)&n->key;
393 struct in6_addr maddr;
394 struct net_device *dev = n->dev;
395
396 if (!dev || !__in6_dev_get(dev))
397 return;
398 addrconf_addr_solict_mult(addr, &maddr);
399 ipv6_dev_mc_dec(dev, &maddr);
400}
401
402/* called with rtnl held */
403static bool ndisc_allow_add(const struct net_device *dev,
404 struct netlink_ext_ack *extack)
405{
406 struct inet6_dev *idev = __in6_dev_get(dev);
407
408 if (!idev || idev->cnf.disable_ipv6) {
409 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
410 return false;
411 }
412
413 return true;
414}
415
416static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
417 int len)
418{
419 int hlen = LL_RESERVED_SPACE(dev);
420 int tlen = dev->needed_tailroom;
421 struct sk_buff *skb;
422
423 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
424 if (!skb)
425 return NULL;
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 rcu_read_lock();
437 skb_set_owner_w(skb, dev_net_rcu(dev)->ipv6.ndisc_sk);
438 rcu_read_unlock();
439
440 return skb;
441}
442
443static void ip6_nd_hdr(struct sk_buff *skb,
444 const struct in6_addr *saddr,
445 const struct in6_addr *daddr,
446 int hop_limit, int len)
447{
448 struct ipv6hdr *hdr;
449 struct inet6_dev *idev;
450 unsigned tclass;
451
452 rcu_read_lock();
453 idev = __in6_dev_get(skb->dev);
454 tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0;
455 rcu_read_unlock();
456
457 skb_push(skb, sizeof(*hdr));
458 skb_reset_network_header(skb);
459 hdr = ipv6_hdr(skb);
460
461 ip6_flow_hdr(hdr, tclass, 0);
462
463 hdr->payload_len = htons(len);
464 hdr->nexthdr = IPPROTO_ICMPV6;
465 hdr->hop_limit = hop_limit;
466
467 hdr->saddr = *saddr;
468 hdr->daddr = *daddr;
469}
470
471void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
472 const struct in6_addr *saddr)
473{
474 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
475 struct dst_entry *dst = skb_dst(skb);
476 struct inet6_dev *idev;
477 struct net *net;
478 struct sock *sk;
479 int err;
480 u8 type;
481
482 type = icmp6h->icmp6_type;
483
484 rcu_read_lock();
485
486 net = dev_net_rcu(skb->dev);
487 sk = net->ipv6.ndisc_sk;
488 if (!dst) {
489 struct flowi6 fl6;
490 int oif = skb->dev->ifindex;
491
492 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
493 dst = icmp6_dst_alloc(skb->dev, &fl6);
494 if (IS_ERR(dst)) {
495 rcu_read_unlock();
496 kfree_skb(skb);
497 return;
498 }
499
500 skb_dst_set(skb, dst);
501 }
502
503 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
504 IPPROTO_ICMPV6,
505 csum_partial(icmp6h,
506 skb->len, 0));
507
508 ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len);
509
510 idev = __in6_dev_get(dst->dev);
511 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
512
513 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
514 net, sk, skb, NULL, dst->dev,
515 dst_output);
516 if (!err) {
517 ICMP6MSGOUT_INC_STATS(net, idev, type);
518 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
519 }
520
521 rcu_read_unlock();
522}
523EXPORT_SYMBOL(ndisc_send_skb);
524
525void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
526 const struct in6_addr *solicited_addr,
527 bool router, bool solicited, bool override, bool inc_opt)
528{
529 struct sk_buff *skb;
530 struct in6_addr tmpaddr;
531 struct inet6_ifaddr *ifp;
532 const struct in6_addr *src_addr;
533 struct nd_msg *msg;
534 int optlen = 0;
535
536 /* for anycast or proxy, solicited_addr != src_addr */
537 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
538 if (ifp) {
539 src_addr = solicited_addr;
540 if (ifp->flags & IFA_F_OPTIMISTIC)
541 override = false;
542 inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao);
543 in6_ifa_put(ifp);
544 } else {
545 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
546 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
547 &tmpaddr))
548 return;
549 src_addr = &tmpaddr;
550 }
551
552 if (!dev->addr_len)
553 inc_opt = false;
554 if (inc_opt)
555 optlen += ndisc_opt_addr_space(dev,
556 NDISC_NEIGHBOUR_ADVERTISEMENT);
557
558 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
559 if (!skb)
560 return;
561
562 msg = skb_put(skb, sizeof(*msg));
563 *msg = (struct nd_msg) {
564 .icmph = {
565 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
566 .icmp6_router = router,
567 .icmp6_solicited = solicited,
568 .icmp6_override = override,
569 },
570 .target = *solicited_addr,
571 };
572
573 if (inc_opt)
574 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
575 dev->dev_addr,
576 NDISC_NEIGHBOUR_ADVERTISEMENT);
577
578 ndisc_send_skb(skb, daddr, src_addr);
579}
580
581static void ndisc_send_unsol_na(struct net_device *dev)
582{
583 struct inet6_dev *idev;
584 struct inet6_ifaddr *ifa;
585
586 idev = in6_dev_get(dev);
587 if (!idev)
588 return;
589
590 read_lock_bh(&idev->lock);
591 list_for_each_entry(ifa, &idev->addr_list, if_list) {
592 /* skip tentative addresses until dad completes */
593 if (ifa->flags & IFA_F_TENTATIVE &&
594 !(ifa->flags & IFA_F_OPTIMISTIC))
595 continue;
596
597 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
598 /*router=*/ !!idev->cnf.forwarding,
599 /*solicited=*/ false, /*override=*/ true,
600 /*inc_opt=*/ true);
601 }
602 read_unlock_bh(&idev->lock);
603
604 in6_dev_put(idev);
605}
606
607struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
608 const struct in6_addr *saddr, u64 nonce)
609{
610 int inc_opt = dev->addr_len;
611 struct sk_buff *skb;
612 struct nd_msg *msg;
613 int optlen = 0;
614
615 if (!saddr)
616 return NULL;
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 NULL;
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 return skb;
651}
652EXPORT_SYMBOL(ndisc_ns_create);
653
654void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
655 const struct in6_addr *daddr, const struct in6_addr *saddr,
656 u64 nonce)
657{
658 struct in6_addr addr_buf;
659 struct sk_buff *skb;
660
661 if (!saddr) {
662 if (ipv6_get_lladdr(dev, &addr_buf,
663 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
664 return;
665 saddr = &addr_buf;
666 }
667
668 skb = ndisc_ns_create(dev, solicit, saddr, nonce);
669
670 if (skb)
671 ndisc_send_skb(skb, daddr, saddr);
672}
673
674void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
675 const struct in6_addr *daddr)
676{
677 struct sk_buff *skb;
678 struct rs_msg *msg;
679 int send_sllao = dev->addr_len;
680 int optlen = 0;
681
682#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
683 /*
684 * According to section 2.2 of RFC 4429, we must not
685 * send router solicitations with a sllao from
686 * optimistic addresses, but we may send the solicitation
687 * if we don't include the sllao. So here we check
688 * if our address is optimistic, and if so, we
689 * suppress the inclusion of the sllao.
690 */
691 if (send_sllao) {
692 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
693 dev, 1);
694 if (ifp) {
695 if (ifp->flags & IFA_F_OPTIMISTIC) {
696 send_sllao = 0;
697 }
698 in6_ifa_put(ifp);
699 } else {
700 send_sllao = 0;
701 }
702 }
703#endif
704 if (send_sllao)
705 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
706
707 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
708 if (!skb)
709 return;
710
711 msg = skb_put(skb, sizeof(*msg));
712 *msg = (struct rs_msg) {
713 .icmph = {
714 .icmp6_type = NDISC_ROUTER_SOLICITATION,
715 },
716 };
717
718 if (send_sllao)
719 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
720 dev->dev_addr,
721 NDISC_ROUTER_SOLICITATION);
722
723 ndisc_send_skb(skb, daddr, saddr);
724}
725
726
727static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
728{
729 /*
730 * "The sender MUST return an ICMP
731 * destination unreachable"
732 */
733 dst_link_failure(skb);
734 kfree_skb(skb);
735}
736
737/* Called with locked neigh: either read or both */
738
739static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
740{
741 struct in6_addr *saddr = NULL;
742 struct in6_addr mcaddr;
743 struct net_device *dev = neigh->dev;
744 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
745 int probes = atomic_read(&neigh->probes);
746
747 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
748 dev, false, 1,
749 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
750 saddr = &ipv6_hdr(skb)->saddr;
751 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
752 if (probes < 0) {
753 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) {
754 ND_PRINTK(1, dbg,
755 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
756 __func__, target);
757 }
758 ndisc_send_ns(dev, target, target, saddr, 0);
759 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
760 neigh_app_ns(neigh);
761 } else {
762 addrconf_addr_solict_mult(target, &mcaddr);
763 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
764 }
765}
766
767static int pndisc_is_router(const void *pkey,
768 struct net_device *dev)
769{
770 struct pneigh_entry *n;
771 int ret = -1;
772
773 read_lock_bh(&nd_tbl.lock);
774 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
775 if (n)
776 ret = !!(n->flags & NTF_ROUTER);
777 read_unlock_bh(&nd_tbl.lock);
778
779 return ret;
780}
781
782void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
783 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
784 struct ndisc_options *ndopts)
785{
786 neigh_update(neigh, lladdr, new, flags, 0);
787 /* report ndisc ops about neighbour update */
788 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
789}
790
791static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
792{
793 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
794 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
795 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
796 u8 *lladdr = NULL;
797 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
798 offsetof(struct nd_msg, opt));
799 struct ndisc_options ndopts;
800 struct net_device *dev = skb->dev;
801 struct inet6_ifaddr *ifp;
802 struct inet6_dev *idev = NULL;
803 struct neighbour *neigh;
804 int dad = ipv6_addr_any(saddr);
805 int is_router = -1;
806 SKB_DR(reason);
807 u64 nonce = 0;
808 bool inc;
809
810 if (skb->len < sizeof(struct nd_msg))
811 return SKB_DROP_REASON_PKT_TOO_SMALL;
812
813 if (ipv6_addr_is_multicast(&msg->target)) {
814 ND_PRINTK(2, warn, "NS: multicast target address\n");
815 return reason;
816 }
817
818 /*
819 * RFC2461 7.1.1:
820 * DAD has to be destined for solicited node multicast address.
821 */
822 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
823 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
824 return reason;
825 }
826
827 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
828 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
829
830 if (ndopts.nd_opts_src_lladdr) {
831 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
832 if (!lladdr) {
833 ND_PRINTK(2, warn,
834 "NS: invalid link-layer address length\n");
835 return reason;
836 }
837
838 /* RFC2461 7.1.1:
839 * If the IP source address is the unspecified address,
840 * there MUST NOT be source link-layer address option
841 * in the message.
842 */
843 if (dad) {
844 ND_PRINTK(2, warn,
845 "NS: bad DAD packet (link-layer address option)\n");
846 return reason;
847 }
848 }
849 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
850 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
851
852 inc = ipv6_addr_is_multicast(daddr);
853
854 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
855 if (ifp) {
856have_ifp:
857 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
858 if (dad) {
859 if (nonce != 0 && ifp->dad_nonce == nonce) {
860 u8 *np = (u8 *)&nonce;
861 /* Matching nonce if looped back */
862 ND_PRINTK(2, notice,
863 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
864 ifp->idev->dev->name,
865 &ifp->addr, np);
866 goto out;
867 }
868 /*
869 * We are colliding with another node
870 * who is doing DAD
871 * so fail our DAD process
872 */
873 addrconf_dad_failure(skb, ifp);
874 return reason;
875 } else {
876 /*
877 * This is not a dad solicitation.
878 * If we are an optimistic node,
879 * we should respond.
880 * Otherwise, we should ignore it.
881 */
882 if (!(ifp->flags & IFA_F_OPTIMISTIC))
883 goto out;
884 }
885 }
886
887 idev = ifp->idev;
888 } else {
889 struct net *net = dev_net(dev);
890
891 /* perhaps an address on the master device */
892 if (netif_is_l3_slave(dev)) {
893 struct net_device *mdev;
894
895 mdev = netdev_master_upper_dev_get_rcu(dev);
896 if (mdev) {
897 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
898 if (ifp)
899 goto have_ifp;
900 }
901 }
902
903 idev = in6_dev_get(dev);
904 if (!idev) {
905 /* XXX: count this drop? */
906 return reason;
907 }
908
909 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
910 (READ_ONCE(idev->cnf.forwarding) &&
911 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) ||
912 READ_ONCE(idev->cnf.proxy_ndp)) &&
913 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
914 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
915 skb->pkt_type != PACKET_HOST &&
916 inc &&
917 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
918 /*
919 * for anycast or proxy,
920 * sender should delay its response
921 * by a random time between 0 and
922 * MAX_ANYCAST_DELAY_TIME seconds.
923 * (RFC2461) -- yoshfuji
924 */
925 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
926 if (n)
927 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
928 goto out;
929 }
930 } else {
931 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST);
932 goto out;
933 }
934 }
935
936 if (is_router < 0)
937 is_router = READ_ONCE(idev->cnf.forwarding);
938
939 if (dad) {
940 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
941 !!is_router, false, (ifp != NULL), true);
942 goto out;
943 }
944
945 if (inc)
946 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
947 else
948 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
949
950 /*
951 * update / create cache entry
952 * for the source address
953 */
954 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
955 !inc || lladdr || !dev->addr_len);
956 if (neigh)
957 ndisc_update(dev, neigh, lladdr, NUD_STALE,
958 NEIGH_UPDATE_F_WEAK_OVERRIDE|
959 NEIGH_UPDATE_F_OVERRIDE,
960 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
961 if (neigh || !dev->header_ops) {
962 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
963 true, (ifp != NULL && inc), inc);
964 if (neigh)
965 neigh_release(neigh);
966 reason = SKB_CONSUMED;
967 }
968
969out:
970 if (ifp)
971 in6_ifa_put(ifp);
972 else
973 in6_dev_put(idev);
974 return reason;
975}
976
977static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
978{
979 struct inet6_dev *idev = __in6_dev_get(dev);
980
981 switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
982 case 0: /* Don't accept untracked na (absent in neighbor cache) */
983 return 0;
984 case 1: /* Create new entries from na if currently untracked */
985 return 1;
986 case 2: /* Create new entries from untracked na only if saddr is in the
987 * same subnet as an address configured on the interface that
988 * received the na
989 */
990 return !!ipv6_chk_prefix(saddr, dev);
991 default:
992 return 0;
993 }
994}
995
996static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
997{
998 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
999 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1000 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
1001 u8 *lladdr = NULL;
1002 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1003 offsetof(struct nd_msg, opt));
1004 struct ndisc_options ndopts;
1005 struct net_device *dev = skb->dev;
1006 struct inet6_dev *idev = __in6_dev_get(dev);
1007 struct inet6_ifaddr *ifp;
1008 struct neighbour *neigh;
1009 SKB_DR(reason);
1010 u8 new_state;
1011
1012 if (skb->len < sizeof(struct nd_msg))
1013 return SKB_DROP_REASON_PKT_TOO_SMALL;
1014
1015 if (ipv6_addr_is_multicast(&msg->target)) {
1016 ND_PRINTK(2, warn, "NA: target address is multicast\n");
1017 return reason;
1018 }
1019
1020 if (ipv6_addr_is_multicast(daddr) &&
1021 msg->icmph.icmp6_solicited) {
1022 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
1023 return reason;
1024 }
1025
1026 /* For some 802.11 wireless deployments (and possibly other networks),
1027 * there will be a NA proxy and unsolicitd packets are attacks
1028 * and thus should not be accepted.
1029 * drop_unsolicited_na takes precedence over accept_untracked_na
1030 */
1031 if (!msg->icmph.icmp6_solicited && idev &&
1032 READ_ONCE(idev->cnf.drop_unsolicited_na))
1033 return reason;
1034
1035 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
1036 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1037
1038 if (ndopts.nd_opts_tgt_lladdr) {
1039 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1040 if (!lladdr) {
1041 ND_PRINTK(2, warn,
1042 "NA: invalid link-layer address length\n");
1043 return reason;
1044 }
1045 }
1046 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1047 if (ifp) {
1048 if (skb->pkt_type != PACKET_LOOPBACK
1049 && (ifp->flags & IFA_F_TENTATIVE)) {
1050 addrconf_dad_failure(skb, ifp);
1051 return reason;
1052 }
1053 /* What should we make now? The advertisement
1054 is invalid, but ndisc specs say nothing
1055 about it. It could be misconfiguration, or
1056 an smart proxy agent tries to help us :-)
1057
1058 We should not print the error if NA has been
1059 received from loopback - it is just our own
1060 unsolicited advertisement.
1061 */
1062 if (skb->pkt_type != PACKET_LOOPBACK)
1063 ND_PRINTK(1, warn,
1064 "NA: %pM advertised our address %pI6c on %s!\n",
1065 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1066 in6_ifa_put(ifp);
1067 return reason;
1068 }
1069
1070 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1071
1072 /* RFC 9131 updates original Neighbour Discovery RFC 4861.
1073 * NAs with Target LL Address option without a corresponding
1074 * entry in the neighbour cache can now create a STALE neighbour
1075 * cache entry on routers.
1076 *
1077 * entry accept fwding solicited behaviour
1078 * ------- ------ ------ --------- ----------------------
1079 * present X X 0 Set state to STALE
1080 * present X X 1 Set state to REACHABLE
1081 * absent 0 X X Do nothing
1082 * absent 1 0 X Do nothing
1083 * absent 1 1 X Add a new STALE entry
1084 *
1085 * Note that we don't do a (daddr == all-routers-mcast) check.
1086 */
1087 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1088 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) {
1089 if (accept_untracked_na(dev, saddr)) {
1090 neigh = neigh_create(&nd_tbl, &msg->target, dev);
1091 new_state = NUD_STALE;
1092 }
1093 }
1094
1095 if (neigh && !IS_ERR(neigh)) {
1096 u8 old_flags = neigh->flags;
1097 struct net *net = dev_net(dev);
1098
1099 if (READ_ONCE(neigh->nud_state) & NUD_FAILED)
1100 goto out;
1101
1102 /*
1103 * Don't update the neighbor cache entry on a proxy NA from
1104 * ourselves because either the proxied node is off link or it
1105 * has already sent a NA to us.
1106 */
1107 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1108 READ_ONCE(net->ipv6.devconf_all->forwarding) &&
1109 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
1110 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1111 /* XXX: idev->cnf.proxy_ndp */
1112 goto out;
1113 }
1114
1115 ndisc_update(dev, neigh, lladdr,
1116 new_state,
1117 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1118 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1119 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1120 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1121 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1122
1123 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1124 /*
1125 * Change: router to host
1126 */
1127 rt6_clean_tohost(dev_net(dev), saddr);
1128 }
1129 reason = SKB_CONSUMED;
1130out:
1131 neigh_release(neigh);
1132 }
1133 return reason;
1134}
1135
1136static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
1137{
1138 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1139 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1140 struct neighbour *neigh;
1141 struct inet6_dev *idev;
1142 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1143 struct ndisc_options ndopts;
1144 u8 *lladdr = NULL;
1145 SKB_DR(reason);
1146
1147 if (skb->len < sizeof(*rs_msg))
1148 return SKB_DROP_REASON_PKT_TOO_SMALL;
1149
1150 idev = __in6_dev_get(skb->dev);
1151 if (!idev) {
1152 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1153 return reason;
1154 }
1155
1156 /* Don't accept RS if we're not in router mode */
1157 if (!READ_ONCE(idev->cnf.forwarding))
1158 goto out;
1159
1160 /*
1161 * Don't update NCE if src = ::;
1162 * this implies that the source node has no ip address assigned yet.
1163 */
1164 if (ipv6_addr_any(saddr))
1165 goto out;
1166
1167 /* Parse ND options */
1168 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts))
1169 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1170
1171 if (ndopts.nd_opts_src_lladdr) {
1172 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1173 skb->dev);
1174 if (!lladdr)
1175 goto out;
1176 }
1177
1178 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1179 if (neigh) {
1180 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1181 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1182 NEIGH_UPDATE_F_OVERRIDE|
1183 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1184 NDISC_ROUTER_SOLICITATION, &ndopts);
1185 neigh_release(neigh);
1186 reason = SKB_CONSUMED;
1187 }
1188out:
1189 return reason;
1190}
1191
1192static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1193{
1194 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1195 struct sk_buff *skb;
1196 struct nlmsghdr *nlh;
1197 struct nduseroptmsg *ndmsg;
1198 struct net *net = dev_net(ra->dev);
1199 int err;
1200 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1201 + (opt->nd_opt_len << 3));
1202 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1203
1204 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1205 if (!skb) {
1206 err = -ENOBUFS;
1207 goto errout;
1208 }
1209
1210 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1211 if (!nlh) {
1212 goto nla_put_failure;
1213 }
1214
1215 ndmsg = nlmsg_data(nlh);
1216 ndmsg->nduseropt_family = AF_INET6;
1217 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1218 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1219 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1220 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1221
1222 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1223
1224 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1225 goto nla_put_failure;
1226 nlmsg_end(skb, nlh);
1227
1228 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1229 return;
1230
1231nla_put_failure:
1232 nlmsg_free(skb);
1233 err = -EMSGSIZE;
1234errout:
1235 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1236}
1237
1238static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
1239{
1240 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1241 bool send_ifinfo_notify = false;
1242 struct neighbour *neigh = NULL;
1243 struct ndisc_options ndopts;
1244 struct fib6_info *rt = NULL;
1245 struct inet6_dev *in6_dev;
1246 struct fib6_table *table;
1247 u32 defrtr_usr_metric;
1248 unsigned int pref = 0;
1249 __u32 old_if_flags;
1250 struct net *net;
1251 SKB_DR(reason);
1252 int lifetime;
1253 int optlen;
1254
1255 __u8 *opt = (__u8 *)(ra_msg + 1);
1256
1257 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1258 sizeof(struct ra_msg);
1259
1260 ND_PRINTK(2, info,
1261 "RA: %s, dev: %s\n",
1262 __func__, skb->dev->name);
1263 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1264 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1265 return reason;
1266 }
1267 if (optlen < 0)
1268 return SKB_DROP_REASON_PKT_TOO_SMALL;
1269
1270#ifdef CONFIG_IPV6_NDISC_NODETYPE
1271 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1272 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1273 return reason;
1274 }
1275#endif
1276
1277 in6_dev = __in6_dev_get(skb->dev);
1278 if (!in6_dev) {
1279 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1280 skb->dev->name);
1281 return reason;
1282 }
1283
1284 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
1285 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1286
1287 if (!ipv6_accept_ra(in6_dev)) {
1288 ND_PRINTK(2, info,
1289 "RA: %s, did not accept ra for dev: %s\n",
1290 __func__, skb->dev->name);
1291 goto skip_linkparms;
1292 }
1293
1294#ifdef CONFIG_IPV6_NDISC_NODETYPE
1295 /* skip link-specific parameters from interior routers */
1296 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1297 ND_PRINTK(2, info,
1298 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1299 __func__, skb->dev->name);
1300 goto skip_linkparms;
1301 }
1302#endif
1303
1304 if (in6_dev->if_flags & IF_RS_SENT) {
1305 /*
1306 * flag that an RA was received after an RS was sent
1307 * out on this interface.
1308 */
1309 in6_dev->if_flags |= IF_RA_RCVD;
1310 }
1311
1312 /*
1313 * Remember the managed/otherconf flags from most recently
1314 * received RA message (RFC 2462) -- yoshfuji
1315 */
1316 old_if_flags = in6_dev->if_flags;
1317 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1318 IF_RA_OTHERCONF)) |
1319 (ra_msg->icmph.icmp6_addrconf_managed ?
1320 IF_RA_MANAGED : 0) |
1321 (ra_msg->icmph.icmp6_addrconf_other ?
1322 IF_RA_OTHERCONF : 0);
1323
1324 if (old_if_flags != in6_dev->if_flags)
1325 send_ifinfo_notify = true;
1326
1327 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) {
1328 ND_PRINTK(2, info,
1329 "RA: %s, defrtr is false for dev: %s\n",
1330 __func__, skb->dev->name);
1331 goto skip_defrtr;
1332 }
1333
1334 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1335 if (lifetime != 0 &&
1336 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) {
1337 ND_PRINTK(2, info,
1338 "RA: router lifetime (%ds) is too short: %s\n",
1339 lifetime, skb->dev->name);
1340 goto skip_defrtr;
1341 }
1342
1343 /* Do not accept RA with source-addr found on local machine unless
1344 * accept_ra_from_local is set to true.
1345 */
1346 net = dev_net(in6_dev->dev);
1347 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1348 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1349 ND_PRINTK(2, info,
1350 "RA from local address detected on dev: %s: default router ignored\n",
1351 skb->dev->name);
1352 goto skip_defrtr;
1353 }
1354
1355#ifdef CONFIG_IPV6_ROUTER_PREF
1356 pref = ra_msg->icmph.icmp6_router_pref;
1357 /* 10b is handled as if it were 00b (medium) */
1358 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1359 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref))
1360 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1361#endif
1362 /* routes added from RAs do not use nexthop objects */
1363 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1364 if (rt) {
1365 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1366 rt->fib6_nh->fib_nh_dev, NULL,
1367 &ipv6_hdr(skb)->saddr);
1368 if (!neigh) {
1369 ND_PRINTK(0, err,
1370 "RA: %s got default router without neighbour\n",
1371 __func__);
1372 fib6_info_release(rt);
1373 return reason;
1374 }
1375 }
1376 /* Set default route metric as specified by user */
1377 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1378 /* delete the route if lifetime is 0 or if metric needs change */
1379 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1380 ip6_del_rt(net, rt, false);
1381 rt = NULL;
1382 }
1383
1384 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
1385 rt, lifetime, defrtr_usr_metric, skb->dev->name);
1386 if (!rt && lifetime) {
1387 ND_PRINTK(3, info, "RA: adding default router\n");
1388
1389 if (neigh)
1390 neigh_release(neigh);
1391
1392 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1393 skb->dev, pref, defrtr_usr_metric,
1394 lifetime);
1395 if (!rt) {
1396 ND_PRINTK(0, err,
1397 "RA: %s failed to add default route\n",
1398 __func__);
1399 return reason;
1400 }
1401
1402 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1403 rt->fib6_nh->fib_nh_dev, NULL,
1404 &ipv6_hdr(skb)->saddr);
1405 if (!neigh) {
1406 ND_PRINTK(0, err,
1407 "RA: %s got default router without neighbour\n",
1408 __func__);
1409 fib6_info_release(rt);
1410 return reason;
1411 }
1412 neigh->flags |= NTF_ROUTER;
1413 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1414 struct nl_info nlinfo = {
1415 .nl_net = net,
1416 };
1417 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1418 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
1419 }
1420
1421 if (rt) {
1422 table = rt->fib6_table;
1423 spin_lock_bh(&table->tb6_lock);
1424
1425 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1426 fib6_add_gc_list(rt);
1427
1428 spin_unlock_bh(&table->tb6_lock);
1429 }
1430 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 &&
1431 ra_msg->icmph.icmp6_hop_limit) {
1432 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <=
1433 ra_msg->icmph.icmp6_hop_limit) {
1434 WRITE_ONCE(in6_dev->cnf.hop_limit,
1435 ra_msg->icmph.icmp6_hop_limit);
1436 fib6_metric_set(rt, RTAX_HOPLIMIT,
1437 ra_msg->icmph.icmp6_hop_limit);
1438 } else {
1439 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1440 }
1441 }
1442
1443skip_defrtr:
1444
1445 /*
1446 * Update Reachable Time and Retrans Timer
1447 */
1448
1449 if (in6_dev->nd_parms) {
1450 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1451
1452 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1453 rtime = (rtime*HZ)/1000;
1454 if (rtime < HZ/100)
1455 rtime = HZ/100;
1456 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1457 in6_dev->tstamp = jiffies;
1458 send_ifinfo_notify = true;
1459 }
1460
1461 rtime = ntohl(ra_msg->reachable_time);
1462 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1463 rtime = (rtime*HZ)/1000;
1464
1465 if (rtime < HZ/10)
1466 rtime = HZ/10;
1467
1468 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1469 NEIGH_VAR_SET(in6_dev->nd_parms,
1470 BASE_REACHABLE_TIME, rtime);
1471 NEIGH_VAR_SET(in6_dev->nd_parms,
1472 GC_STALETIME, 3 * rtime);
1473 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1474 in6_dev->tstamp = jiffies;
1475 send_ifinfo_notify = true;
1476 }
1477 }
1478 }
1479
1480skip_linkparms:
1481
1482 /*
1483 * Process options.
1484 */
1485
1486 if (!neigh)
1487 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1488 skb->dev, 1);
1489 if (neigh) {
1490 u8 *lladdr = NULL;
1491 if (ndopts.nd_opts_src_lladdr) {
1492 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1493 skb->dev);
1494 if (!lladdr) {
1495 ND_PRINTK(2, warn,
1496 "RA: invalid link-layer address length\n");
1497 goto out;
1498 }
1499 }
1500 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1501 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1502 NEIGH_UPDATE_F_OVERRIDE|
1503 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1504 NEIGH_UPDATE_F_ISROUTER,
1505 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1506 reason = SKB_CONSUMED;
1507 }
1508
1509 if (!ipv6_accept_ra(in6_dev)) {
1510 ND_PRINTK(2, info,
1511 "RA: %s, accept_ra is false for dev: %s\n",
1512 __func__, skb->dev->name);
1513 goto out;
1514 }
1515
1516#ifdef CONFIG_IPV6_ROUTE_INFO
1517 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1518 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1519 in6_dev->dev, 0)) {
1520 ND_PRINTK(2, info,
1521 "RA from local address detected on dev: %s: router info ignored.\n",
1522 skb->dev->name);
1523 goto skip_routeinfo;
1524 }
1525
1526 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) {
1527 struct nd_opt_hdr *p;
1528 for (p = ndopts.nd_opts_ri;
1529 p;
1530 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1531 struct route_info *ri = (struct route_info *)p;
1532#ifdef CONFIG_IPV6_NDISC_NODETYPE
1533 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1534 ri->prefix_len == 0)
1535 continue;
1536#endif
1537 if (ri->prefix_len == 0 &&
1538 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr))
1539 continue;
1540 if (ri->lifetime != 0 &&
1541 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft))
1542 continue;
1543 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen))
1544 continue;
1545 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen))
1546 continue;
1547 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1548 &ipv6_hdr(skb)->saddr);
1549 }
1550 }
1551
1552skip_routeinfo:
1553#endif
1554
1555#ifdef CONFIG_IPV6_NDISC_NODETYPE
1556 /* skip link-specific ndopts from interior routers */
1557 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1558 ND_PRINTK(2, info,
1559 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1560 __func__, skb->dev->name);
1561 goto out;
1562 }
1563#endif
1564
1565 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) {
1566 struct nd_opt_hdr *p;
1567 for (p = ndopts.nd_opts_pi;
1568 p;
1569 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1570 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1571 (p->nd_opt_len) << 3,
1572 ndopts.nd_opts_src_lladdr != NULL);
1573 }
1574 }
1575
1576 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) {
1577 __be32 n;
1578 u32 mtu;
1579
1580 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1581 mtu = ntohl(n);
1582
1583 if (in6_dev->ra_mtu != mtu) {
1584 in6_dev->ra_mtu = mtu;
1585 send_ifinfo_notify = true;
1586 }
1587
1588 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1589 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1590 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) {
1591 WRITE_ONCE(in6_dev->cnf.mtu6, mtu);
1592 fib6_metric_set(rt, RTAX_MTU, mtu);
1593 rt6_mtu_change(skb->dev, mtu);
1594 }
1595 }
1596
1597 if (ndopts.nd_useropts) {
1598 struct nd_opt_hdr *p;
1599 for (p = ndopts.nd_useropts;
1600 p;
1601 p = ndisc_next_useropt(skb->dev, p,
1602 ndopts.nd_useropts_end)) {
1603 ndisc_ra_useropt(skb, p);
1604 }
1605 }
1606
1607 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1608 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1609 }
1610out:
1611 /* Send a notify if RA changed managed/otherconf flags or
1612 * timer settings or ra_mtu value
1613 */
1614 if (send_ifinfo_notify)
1615 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1616
1617 fib6_info_release(rt);
1618 if (neigh)
1619 neigh_release(neigh);
1620 return reason;
1621}
1622
1623static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
1624{
1625 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1626 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1627 offsetof(struct rd_msg, opt));
1628 struct ndisc_options ndopts;
1629 SKB_DR(reason);
1630 u8 *hdr;
1631
1632#ifdef CONFIG_IPV6_NDISC_NODETYPE
1633 switch (skb->ndisc_nodetype) {
1634 case NDISC_NODETYPE_HOST:
1635 case NDISC_NODETYPE_NODEFAULT:
1636 ND_PRINTK(2, warn,
1637 "Redirect: from host or unauthorized router\n");
1638 return reason;
1639 }
1640#endif
1641
1642 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1643 ND_PRINTK(2, warn,
1644 "Redirect: source address is not link-local\n");
1645 return reason;
1646 }
1647
1648 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1649 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1650
1651 if (!ndopts.nd_opts_rh) {
1652 ip6_redirect_no_header(skb, dev_net(skb->dev),
1653 skb->dev->ifindex);
1654 return reason;
1655 }
1656
1657 hdr = (u8 *)ndopts.nd_opts_rh;
1658 hdr += 8;
1659 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1660 return SKB_DROP_REASON_PKT_TOO_SMALL;
1661
1662 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1663}
1664
1665static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1666 struct sk_buff *orig_skb,
1667 int rd_len)
1668{
1669 u8 *opt = skb_put(skb, rd_len);
1670
1671 memset(opt, 0, 8);
1672 *(opt++) = ND_OPT_REDIRECT_HDR;
1673 *(opt++) = (rd_len >> 3);
1674 opt += 6;
1675
1676 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1677 rd_len - 8);
1678}
1679
1680void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1681{
1682 struct net_device *dev = skb->dev;
1683 struct net *net = dev_net(dev);
1684 struct sock *sk = net->ipv6.ndisc_sk;
1685 int optlen = 0;
1686 struct inet_peer *peer;
1687 struct sk_buff *buff;
1688 struct rd_msg *msg;
1689 struct in6_addr saddr_buf;
1690 struct rt6_info *rt;
1691 struct dst_entry *dst;
1692 struct flowi6 fl6;
1693 int rd_len;
1694 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1695 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1696 bool ret;
1697
1698 if (netif_is_l3_master(skb->dev)) {
1699 dev = dev_get_by_index_rcu(dev_net(skb->dev), IPCB(skb)->iif);
1700 if (!dev)
1701 return;
1702 }
1703
1704 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1705 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1706 dev->name);
1707 return;
1708 }
1709
1710 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1711 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1712 ND_PRINTK(2, warn,
1713 "Redirect: target address is not link-local unicast\n");
1714 return;
1715 }
1716
1717 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1718 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1719
1720 dst = ip6_route_output(net, NULL, &fl6);
1721 if (dst->error) {
1722 dst_release(dst);
1723 return;
1724 }
1725 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1726 if (IS_ERR(dst))
1727 return;
1728
1729 rt = dst_rt6_info(dst);
1730
1731 if (rt->rt6i_flags & RTF_GATEWAY) {
1732 ND_PRINTK(2, warn,
1733 "Redirect: destination is not a neighbour\n");
1734 goto release;
1735 }
1736
1737 rcu_read_lock();
1738 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr);
1739 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1740 rcu_read_unlock();
1741
1742 if (!ret)
1743 goto release;
1744
1745 if (dev->addr_len) {
1746 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1747 if (!neigh) {
1748 ND_PRINTK(2, warn,
1749 "Redirect: no neigh for target address\n");
1750 goto release;
1751 }
1752
1753 read_lock_bh(&neigh->lock);
1754 if (neigh->nud_state & NUD_VALID) {
1755 memcpy(ha_buf, neigh->ha, dev->addr_len);
1756 read_unlock_bh(&neigh->lock);
1757 ha = ha_buf;
1758 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1759 ops_data_buf,
1760 &ops_data);
1761 } else
1762 read_unlock_bh(&neigh->lock);
1763
1764 neigh_release(neigh);
1765 }
1766
1767 rd_len = min_t(unsigned int,
1768 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1769 skb->len + 8);
1770 rd_len &= ~0x7;
1771 optlen += rd_len;
1772
1773 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1774 if (!buff)
1775 goto release;
1776
1777 msg = skb_put(buff, sizeof(*msg));
1778 *msg = (struct rd_msg) {
1779 .icmph = {
1780 .icmp6_type = NDISC_REDIRECT,
1781 },
1782 .target = *target,
1783 .dest = ipv6_hdr(skb)->daddr,
1784 };
1785
1786 /*
1787 * include target_address option
1788 */
1789
1790 if (ha)
1791 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1792
1793 /*
1794 * build redirect option and copy skb over to the new packet.
1795 */
1796
1797 if (rd_len)
1798 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1799
1800 skb_dst_set(buff, dst);
1801 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1802 return;
1803
1804release:
1805 dst_release(dst);
1806}
1807
1808static void pndisc_redo(struct sk_buff *skb)
1809{
1810 enum skb_drop_reason reason = ndisc_recv_ns(skb);
1811
1812 kfree_skb_reason(skb, reason);
1813}
1814
1815static int ndisc_is_multicast(const void *pkey)
1816{
1817 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1818}
1819
1820static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1821{
1822 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1823
1824 if (!idev)
1825 return true;
1826 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1827 READ_ONCE(idev->cnf.suppress_frag_ndisc)) {
1828 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1829 return true;
1830 }
1831 return false;
1832}
1833
1834enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
1835{
1836 struct nd_msg *msg;
1837 SKB_DR(reason);
1838
1839 if (ndisc_suppress_frag_ndisc(skb))
1840 return SKB_DROP_REASON_IPV6_NDISC_FRAG;
1841
1842 if (skb_linearize(skb))
1843 return SKB_DROP_REASON_NOMEM;
1844
1845 msg = (struct nd_msg *)skb_transport_header(skb);
1846
1847 __skb_push(skb, skb->data - skb_transport_header(skb));
1848
1849 if (ipv6_hdr(skb)->hop_limit != 255) {
1850 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1851 ipv6_hdr(skb)->hop_limit);
1852 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT;
1853 }
1854
1855 if (msg->icmph.icmp6_code != 0) {
1856 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1857 msg->icmph.icmp6_code);
1858 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE;
1859 }
1860
1861 switch (msg->icmph.icmp6_type) {
1862 case NDISC_NEIGHBOUR_SOLICITATION:
1863 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1864 reason = ndisc_recv_ns(skb);
1865 break;
1866
1867 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1868 reason = ndisc_recv_na(skb);
1869 break;
1870
1871 case NDISC_ROUTER_SOLICITATION:
1872 reason = ndisc_recv_rs(skb);
1873 break;
1874
1875 case NDISC_ROUTER_ADVERTISEMENT:
1876 reason = ndisc_router_discovery(skb);
1877 break;
1878
1879 case NDISC_REDIRECT:
1880 reason = ndisc_redirect_rcv(skb);
1881 break;
1882 }
1883
1884 return reason;
1885}
1886
1887static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1888{
1889 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1890 struct netdev_notifier_change_info *change_info;
1891 struct net *net = dev_net(dev);
1892 struct inet6_dev *idev;
1893 bool evict_nocarrier;
1894
1895 switch (event) {
1896 case NETDEV_CHANGEADDR:
1897 neigh_changeaddr(&nd_tbl, dev);
1898 fib6_run_gc(0, net, false);
1899 fallthrough;
1900 case NETDEV_UP:
1901 idev = in6_dev_get(dev);
1902 if (!idev)
1903 break;
1904 if (READ_ONCE(idev->cnf.ndisc_notify) ||
1905 READ_ONCE(net->ipv6.devconf_all->ndisc_notify))
1906 ndisc_send_unsol_na(dev);
1907 in6_dev_put(idev);
1908 break;
1909 case NETDEV_CHANGE:
1910 idev = in6_dev_get(dev);
1911 if (!idev)
1912 evict_nocarrier = true;
1913 else {
1914 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) &&
1915 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier);
1916 in6_dev_put(idev);
1917 }
1918
1919 change_info = ptr;
1920 if (change_info->flags_changed & IFF_NOARP)
1921 neigh_changeaddr(&nd_tbl, dev);
1922 if (evict_nocarrier && !netif_carrier_ok(dev))
1923 neigh_carrier_down(&nd_tbl, dev);
1924 break;
1925 case NETDEV_DOWN:
1926 neigh_ifdown(&nd_tbl, dev);
1927 fib6_run_gc(0, net, false);
1928 break;
1929 case NETDEV_NOTIFY_PEERS:
1930 ndisc_send_unsol_na(dev);
1931 break;
1932 default:
1933 break;
1934 }
1935
1936 return NOTIFY_DONE;
1937}
1938
1939static struct notifier_block ndisc_netdev_notifier = {
1940 .notifier_call = ndisc_netdev_event,
1941 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1942};
1943
1944#ifdef CONFIG_SYSCTL
1945static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl,
1946 const char *func, const char *dev_name)
1947{
1948 static char warncomm[TASK_COMM_LEN];
1949 static int warned;
1950 if (strcmp(warncomm, current->comm) && warned < 5) {
1951 strscpy(warncomm, current->comm);
1952 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1953 warncomm, func,
1954 dev_name, ctl->procname,
1955 dev_name, ctl->procname);
1956 warned++;
1957 }
1958}
1959
1960int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer,
1961 size_t *lenp, loff_t *ppos)
1962{
1963 struct net_device *dev = ctl->extra1;
1964 struct inet6_dev *idev;
1965 int ret;
1966
1967 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1968 (strcmp(ctl->procname, "base_reachable_time") == 0))
1969 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1970
1971 if (strcmp(ctl->procname, "retrans_time") == 0)
1972 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1973
1974 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1975 ret = neigh_proc_dointvec_jiffies(ctl, write,
1976 buffer, lenp, ppos);
1977
1978 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1979 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1980 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1981 buffer, lenp, ppos);
1982 else
1983 ret = -1;
1984
1985 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1986 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1987 idev->nd_parms->reachable_time =
1988 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1989 WRITE_ONCE(idev->tstamp, jiffies);
1990 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1991 in6_dev_put(idev);
1992 }
1993 return ret;
1994}
1995
1996
1997#endif
1998
1999static int __net_init ndisc_net_init(struct net *net)
2000{
2001 struct ipv6_pinfo *np;
2002 struct sock *sk;
2003 int err;
2004
2005 err = inet_ctl_sock_create(&sk, PF_INET6,
2006 SOCK_RAW, IPPROTO_ICMPV6, net);
2007 if (err < 0) {
2008 ND_PRINTK(0, err,
2009 "NDISC: Failed to initialize the control socket (err %d)\n",
2010 err);
2011 return err;
2012 }
2013
2014 net->ipv6.ndisc_sk = sk;
2015
2016 np = inet6_sk(sk);
2017 np->hop_limit = 255;
2018 /* Do not loopback ndisc messages */
2019 inet6_clear_bit(MC6_LOOP, sk);
2020
2021 return 0;
2022}
2023
2024static void __net_exit ndisc_net_exit(struct net *net)
2025{
2026 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
2027}
2028
2029static struct pernet_operations ndisc_net_ops = {
2030 .init = ndisc_net_init,
2031 .exit = ndisc_net_exit,
2032};
2033
2034int __init ndisc_init(void)
2035{
2036 int err;
2037
2038 err = register_pernet_subsys(&ndisc_net_ops);
2039 if (err)
2040 return err;
2041 /*
2042 * Initialize the neighbour table
2043 */
2044 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
2045
2046#ifdef CONFIG_SYSCTL
2047 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
2048 ndisc_ifinfo_sysctl_change);
2049 if (err)
2050 goto out_unregister_pernet;
2051out:
2052#endif
2053 return err;
2054
2055#ifdef CONFIG_SYSCTL
2056out_unregister_pernet:
2057 unregister_pernet_subsys(&ndisc_net_ops);
2058 goto out;
2059#endif
2060}
2061
2062int __init ndisc_late_init(void)
2063{
2064 return register_netdevice_notifier(&ndisc_netdev_notifier);
2065}
2066
2067void ndisc_late_cleanup(void)
2068{
2069 unregister_netdevice_notifier(&ndisc_netdev_notifier);
2070}
2071
2072void ndisc_cleanup(void)
2073{
2074#ifdef CONFIG_SYSCTL
2075 neigh_sysctl_unregister(&nd_tbl.parms);
2076#endif
2077 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
2078 unregister_pernet_subsys(&ndisc_net_ops);
2079}
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 * Alexey I. Froloff : RFC6106 (DNSSL) support
19 * Pierre Ynard : export userland ND options
20 * through netlink (RDNSS support)
21 * Lars Fenneberg : fixed MTU setting on receipt
22 * of an RA.
23 * Janos Farkas : kmalloc failure checks
24 * Alexey Kuznetsov : state machine reworked
25 * and moved to net/core.
26 * Pekka Savola : RFC2461 validation
27 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
28 */
29
30#define pr_fmt(fmt) "ICMPv6: " fmt
31
32#include <linux/module.h>
33#include <linux/errno.h>
34#include <linux/types.h>
35#include <linux/socket.h>
36#include <linux/sockios.h>
37#include <linux/sched.h>
38#include <linux/net.h>
39#include <linux/in6.h>
40#include <linux/route.h>
41#include <linux/init.h>
42#include <linux/rcupdate.h>
43#include <linux/slab.h>
44#ifdef CONFIG_SYSCTL
45#include <linux/sysctl.h>
46#endif
47
48#include <linux/if_addr.h>
49#include <linux/if_arp.h>
50#include <linux/ipv6.h>
51#include <linux/icmpv6.h>
52#include <linux/jhash.h>
53
54#include <net/sock.h>
55#include <net/snmp.h>
56
57#include <net/ipv6.h>
58#include <net/protocol.h>
59#include <net/ndisc.h>
60#include <net/ip6_route.h>
61#include <net/addrconf.h>
62#include <net/icmp.h>
63
64#include <net/netlink.h>
65#include <linux/rtnetlink.h>
66
67#include <net/flow.h>
68#include <net/ip6_checksum.h>
69#include <net/inet_common.h>
70#include <linux/proc_fs.h>
71
72#include <linux/netfilter.h>
73#include <linux/netfilter_ipv6.h>
74
75/* Set to 3 to get tracing... */
76#define ND_DEBUG 1
77
78#define ND_PRINTK(val, level, fmt, ...) \
79do { \
80 if (val <= ND_DEBUG) \
81 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \
82} while (0)
83
84static u32 ndisc_hash(const void *pkey,
85 const struct net_device *dev,
86 __u32 *hash_rnd);
87static int ndisc_constructor(struct neighbour *neigh);
88static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
89static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
90static int pndisc_constructor(struct pneigh_entry *n);
91static void pndisc_destructor(struct pneigh_entry *n);
92static void pndisc_redo(struct sk_buff *skb);
93
94static const struct neigh_ops ndisc_generic_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_connected_output,
100};
101
102static const struct neigh_ops ndisc_hh_ops = {
103 .family = AF_INET6,
104 .solicit = ndisc_solicit,
105 .error_report = ndisc_error_report,
106 .output = neigh_resolve_output,
107 .connected_output = neigh_resolve_output,
108};
109
110
111static const struct neigh_ops ndisc_direct_ops = {
112 .family = AF_INET6,
113 .output = neigh_direct_output,
114 .connected_output = neigh_direct_output,
115};
116
117struct neigh_table nd_tbl = {
118 .family = AF_INET6,
119 .key_len = sizeof(struct in6_addr),
120 .hash = ndisc_hash,
121 .constructor = ndisc_constructor,
122 .pconstructor = pndisc_constructor,
123 .pdestructor = pndisc_destructor,
124 .proxy_redo = pndisc_redo,
125 .id = "ndisc_cache",
126 .parms = {
127 .tbl = &nd_tbl,
128 .reachable_time = ND_REACHABLE_TIME,
129 .data = {
130 [NEIGH_VAR_MCAST_PROBES] = 3,
131 [NEIGH_VAR_UCAST_PROBES] = 3,
132 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
133 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
134 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
135 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
136 [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024,
137 [NEIGH_VAR_PROXY_QLEN] = 64,
138 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
139 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
140 },
141 },
142 .gc_interval = 30 * HZ,
143 .gc_thresh1 = 128,
144 .gc_thresh2 = 512,
145 .gc_thresh3 = 1024,
146};
147
148static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data)
149{
150 int pad = ndisc_addr_option_pad(skb->dev->type);
151 int data_len = skb->dev->addr_len;
152 int space = ndisc_opt_addr_space(skb->dev);
153 u8 *opt = skb_put(skb, space);
154
155 opt[0] = type;
156 opt[1] = space>>3;
157
158 memset(opt + 2, 0, pad);
159 opt += pad;
160 space -= pad;
161
162 memcpy(opt+2, data, data_len);
163 data_len += 2;
164 opt += data_len;
165 if ((space -= data_len) > 0)
166 memset(opt, 0, space);
167}
168
169static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
170 struct nd_opt_hdr *end)
171{
172 int type;
173 if (!cur || !end || cur >= end)
174 return NULL;
175 type = cur->nd_opt_type;
176 do {
177 cur = ((void *)cur) + (cur->nd_opt_len << 3);
178 } while(cur < end && cur->nd_opt_type != type);
179 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
180}
181
182static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
183{
184 return opt->nd_opt_type == ND_OPT_RDNSS ||
185 opt->nd_opt_type == ND_OPT_DNSSL;
186}
187
188static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
189 struct nd_opt_hdr *end)
190{
191 if (!cur || !end || cur >= end)
192 return NULL;
193 do {
194 cur = ((void *)cur) + (cur->nd_opt_len << 3);
195 } while(cur < end && !ndisc_is_useropt(cur));
196 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
197}
198
199struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
200 struct ndisc_options *ndopts)
201{
202 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
203
204 if (!nd_opt || opt_len < 0 || !ndopts)
205 return NULL;
206 memset(ndopts, 0, sizeof(*ndopts));
207 while (opt_len) {
208 int l;
209 if (opt_len < sizeof(struct nd_opt_hdr))
210 return NULL;
211 l = nd_opt->nd_opt_len << 3;
212 if (opt_len < l || l == 0)
213 return NULL;
214 switch (nd_opt->nd_opt_type) {
215 case ND_OPT_SOURCE_LL_ADDR:
216 case ND_OPT_TARGET_LL_ADDR:
217 case ND_OPT_MTU:
218 case ND_OPT_REDIRECT_HDR:
219 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
220 ND_PRINTK(2, warn,
221 "%s: duplicated ND6 option found: type=%d\n",
222 __func__, nd_opt->nd_opt_type);
223 } else {
224 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
225 }
226 break;
227 case ND_OPT_PREFIX_INFO:
228 ndopts->nd_opts_pi_end = nd_opt;
229 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
230 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
231 break;
232#ifdef CONFIG_IPV6_ROUTE_INFO
233 case ND_OPT_ROUTE_INFO:
234 ndopts->nd_opts_ri_end = nd_opt;
235 if (!ndopts->nd_opts_ri)
236 ndopts->nd_opts_ri = nd_opt;
237 break;
238#endif
239 default:
240 if (ndisc_is_useropt(nd_opt)) {
241 ndopts->nd_useropts_end = nd_opt;
242 if (!ndopts->nd_useropts)
243 ndopts->nd_useropts = nd_opt;
244 } else {
245 /*
246 * Unknown options must be silently ignored,
247 * to accommodate future extension to the
248 * protocol.
249 */
250 ND_PRINTK(2, notice,
251 "%s: ignored unsupported option; type=%d, len=%d\n",
252 __func__,
253 nd_opt->nd_opt_type,
254 nd_opt->nd_opt_len);
255 }
256 }
257 opt_len -= l;
258 nd_opt = ((void *)nd_opt) + l;
259 }
260 return ndopts;
261}
262
263int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
264{
265 switch (dev->type) {
266 case ARPHRD_ETHER:
267 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
268 case ARPHRD_FDDI:
269 ipv6_eth_mc_map(addr, buf);
270 return 0;
271 case ARPHRD_ARCNET:
272 ipv6_arcnet_mc_map(addr, buf);
273 return 0;
274 case ARPHRD_INFINIBAND:
275 ipv6_ib_mc_map(addr, dev->broadcast, buf);
276 return 0;
277 case ARPHRD_IPGRE:
278 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
279 default:
280 if (dir) {
281 memcpy(buf, dev->broadcast, dev->addr_len);
282 return 0;
283 }
284 }
285 return -EINVAL;
286}
287
288EXPORT_SYMBOL(ndisc_mc_map);
289
290static u32 ndisc_hash(const void *pkey,
291 const struct net_device *dev,
292 __u32 *hash_rnd)
293{
294 return ndisc_hashfn(pkey, dev, hash_rnd);
295}
296
297static int ndisc_constructor(struct neighbour *neigh)
298{
299 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
300 struct net_device *dev = neigh->dev;
301 struct inet6_dev *in6_dev;
302 struct neigh_parms *parms;
303 bool is_multicast = ipv6_addr_is_multicast(addr);
304
305 in6_dev = in6_dev_get(dev);
306 if (in6_dev == NULL) {
307 return -EINVAL;
308 }
309
310 parms = in6_dev->nd_parms;
311 __neigh_parms_put(neigh->parms);
312 neigh->parms = neigh_parms_clone(parms);
313
314 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
315 if (!dev->header_ops) {
316 neigh->nud_state = NUD_NOARP;
317 neigh->ops = &ndisc_direct_ops;
318 neigh->output = neigh_direct_output;
319 } else {
320 if (is_multicast) {
321 neigh->nud_state = NUD_NOARP;
322 ndisc_mc_map(addr, neigh->ha, dev, 1);
323 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
324 neigh->nud_state = NUD_NOARP;
325 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
326 if (dev->flags&IFF_LOOPBACK)
327 neigh->type = RTN_LOCAL;
328 } else if (dev->flags&IFF_POINTOPOINT) {
329 neigh->nud_state = NUD_NOARP;
330 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
331 }
332 if (dev->header_ops->cache)
333 neigh->ops = &ndisc_hh_ops;
334 else
335 neigh->ops = &ndisc_generic_ops;
336 if (neigh->nud_state&NUD_VALID)
337 neigh->output = neigh->ops->connected_output;
338 else
339 neigh->output = neigh->ops->output;
340 }
341 in6_dev_put(in6_dev);
342 return 0;
343}
344
345static int pndisc_constructor(struct pneigh_entry *n)
346{
347 struct in6_addr *addr = (struct in6_addr*)&n->key;
348 struct in6_addr maddr;
349 struct net_device *dev = n->dev;
350
351 if (dev == NULL || __in6_dev_get(dev) == NULL)
352 return -EINVAL;
353 addrconf_addr_solict_mult(addr, &maddr);
354 ipv6_dev_mc_inc(dev, &maddr);
355 return 0;
356}
357
358static void pndisc_destructor(struct pneigh_entry *n)
359{
360 struct in6_addr *addr = (struct in6_addr*)&n->key;
361 struct in6_addr maddr;
362 struct net_device *dev = n->dev;
363
364 if (dev == NULL || __in6_dev_get(dev) == NULL)
365 return;
366 addrconf_addr_solict_mult(addr, &maddr);
367 ipv6_dev_mc_dec(dev, &maddr);
368}
369
370static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
371 int len)
372{
373 int hlen = LL_RESERVED_SPACE(dev);
374 int tlen = dev->needed_tailroom;
375 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
376 struct sk_buff *skb;
377
378 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
379 if (!skb) {
380 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
381 __func__);
382 return NULL;
383 }
384
385 skb->protocol = htons(ETH_P_IPV6);
386 skb->dev = dev;
387
388 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
389 skb_reset_transport_header(skb);
390
391 /* Manually assign socket ownership as we avoid calling
392 * sock_alloc_send_pskb() to bypass wmem buffer limits
393 */
394 skb_set_owner_w(skb, sk);
395
396 return skb;
397}
398
399static void ip6_nd_hdr(struct sk_buff *skb,
400 const struct in6_addr *saddr,
401 const struct in6_addr *daddr,
402 int hop_limit, int len)
403{
404 struct ipv6hdr *hdr;
405
406 skb_push(skb, sizeof(*hdr));
407 skb_reset_network_header(skb);
408 hdr = ipv6_hdr(skb);
409
410 ip6_flow_hdr(hdr, 0, 0);
411
412 hdr->payload_len = htons(len);
413 hdr->nexthdr = IPPROTO_ICMPV6;
414 hdr->hop_limit = hop_limit;
415
416 hdr->saddr = *saddr;
417 hdr->daddr = *daddr;
418}
419
420static void ndisc_send_skb(struct sk_buff *skb,
421 const struct in6_addr *daddr,
422 const struct in6_addr *saddr)
423{
424 struct dst_entry *dst = skb_dst(skb);
425 struct net *net = dev_net(skb->dev);
426 struct sock *sk = net->ipv6.ndisc_sk;
427 struct inet6_dev *idev;
428 int err;
429 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
430 u8 type;
431
432 type = icmp6h->icmp6_type;
433
434 if (!dst) {
435 struct flowi6 fl6;
436
437 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, skb->dev->ifindex);
438 dst = icmp6_dst_alloc(skb->dev, &fl6);
439 if (IS_ERR(dst)) {
440 kfree_skb(skb);
441 return;
442 }
443
444 skb_dst_set(skb, dst);
445 }
446
447 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
448 IPPROTO_ICMPV6,
449 csum_partial(icmp6h,
450 skb->len, 0));
451
452 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
453
454 rcu_read_lock();
455 idev = __in6_dev_get(dst->dev);
456 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
457
458 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
459 dst_output);
460 if (!err) {
461 ICMP6MSGOUT_INC_STATS(net, idev, type);
462 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
463 }
464
465 rcu_read_unlock();
466}
467
468void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
469 const struct in6_addr *daddr,
470 const struct in6_addr *solicited_addr,
471 bool router, bool solicited, bool override, bool inc_opt)
472{
473 struct sk_buff *skb;
474 struct in6_addr tmpaddr;
475 struct inet6_ifaddr *ifp;
476 const struct in6_addr *src_addr;
477 struct nd_msg *msg;
478 int optlen = 0;
479
480 /* for anycast or proxy, solicited_addr != src_addr */
481 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
482 if (ifp) {
483 src_addr = solicited_addr;
484 if (ifp->flags & IFA_F_OPTIMISTIC)
485 override = false;
486 inc_opt |= ifp->idev->cnf.force_tllao;
487 in6_ifa_put(ifp);
488 } else {
489 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
490 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
491 &tmpaddr))
492 return;
493 src_addr = &tmpaddr;
494 }
495
496 if (!dev->addr_len)
497 inc_opt = 0;
498 if (inc_opt)
499 optlen += ndisc_opt_addr_space(dev);
500
501 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
502 if (!skb)
503 return;
504
505 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
506 *msg = (struct nd_msg) {
507 .icmph = {
508 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
509 .icmp6_router = router,
510 .icmp6_solicited = solicited,
511 .icmp6_override = override,
512 },
513 .target = *solicited_addr,
514 };
515
516 if (inc_opt)
517 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
518 dev->dev_addr);
519
520
521 ndisc_send_skb(skb, daddr, src_addr);
522}
523
524static void ndisc_send_unsol_na(struct net_device *dev)
525{
526 struct inet6_dev *idev;
527 struct inet6_ifaddr *ifa;
528
529 idev = in6_dev_get(dev);
530 if (!idev)
531 return;
532
533 read_lock_bh(&idev->lock);
534 list_for_each_entry(ifa, &idev->addr_list, if_list) {
535 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &ifa->addr,
536 /*router=*/ !!idev->cnf.forwarding,
537 /*solicited=*/ false, /*override=*/ true,
538 /*inc_opt=*/ true);
539 }
540 read_unlock_bh(&idev->lock);
541
542 in6_dev_put(idev);
543}
544
545void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
546 const struct in6_addr *solicit,
547 const struct in6_addr *daddr, const struct in6_addr *saddr)
548{
549 struct sk_buff *skb;
550 struct in6_addr addr_buf;
551 int inc_opt = dev->addr_len;
552 int optlen = 0;
553 struct nd_msg *msg;
554
555 if (saddr == NULL) {
556 if (ipv6_get_lladdr(dev, &addr_buf,
557 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
558 return;
559 saddr = &addr_buf;
560 }
561
562 if (ipv6_addr_any(saddr))
563 inc_opt = false;
564 if (inc_opt)
565 optlen += ndisc_opt_addr_space(dev);
566
567 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
568 if (!skb)
569 return;
570
571 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
572 *msg = (struct nd_msg) {
573 .icmph = {
574 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
575 },
576 .target = *solicit,
577 };
578
579 if (inc_opt)
580 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
581 dev->dev_addr);
582
583 ndisc_send_skb(skb, daddr, saddr);
584}
585
586void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
587 const struct in6_addr *daddr)
588{
589 struct sk_buff *skb;
590 struct rs_msg *msg;
591 int send_sllao = dev->addr_len;
592 int optlen = 0;
593
594#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
595 /*
596 * According to section 2.2 of RFC 4429, we must not
597 * send router solicitations with a sllao from
598 * optimistic addresses, but we may send the solicitation
599 * if we don't include the sllao. So here we check
600 * if our address is optimistic, and if so, we
601 * suppress the inclusion of the sllao.
602 */
603 if (send_sllao) {
604 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
605 dev, 1);
606 if (ifp) {
607 if (ifp->flags & IFA_F_OPTIMISTIC) {
608 send_sllao = 0;
609 }
610 in6_ifa_put(ifp);
611 } else {
612 send_sllao = 0;
613 }
614 }
615#endif
616 if (send_sllao)
617 optlen += ndisc_opt_addr_space(dev);
618
619 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
620 if (!skb)
621 return;
622
623 msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
624 *msg = (struct rs_msg) {
625 .icmph = {
626 .icmp6_type = NDISC_ROUTER_SOLICITATION,
627 },
628 };
629
630 if (send_sllao)
631 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
632 dev->dev_addr);
633
634 ndisc_send_skb(skb, daddr, saddr);
635}
636
637
638static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
639{
640 /*
641 * "The sender MUST return an ICMP
642 * destination unreachable"
643 */
644 dst_link_failure(skb);
645 kfree_skb(skb);
646}
647
648/* Called with locked neigh: either read or both */
649
650static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
651{
652 struct in6_addr *saddr = NULL;
653 struct in6_addr mcaddr;
654 struct net_device *dev = neigh->dev;
655 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
656 int probes = atomic_read(&neigh->probes);
657
658 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
659 saddr = &ipv6_hdr(skb)->saddr;
660
661 if ((probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES)) < 0) {
662 if (!(neigh->nud_state & NUD_VALID)) {
663 ND_PRINTK(1, dbg,
664 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
665 __func__, target);
666 }
667 ndisc_send_ns(dev, neigh, target, target, saddr);
668 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
669 neigh_app_ns(neigh);
670 } else {
671 addrconf_addr_solict_mult(target, &mcaddr);
672 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
673 }
674}
675
676static int pndisc_is_router(const void *pkey,
677 struct net_device *dev)
678{
679 struct pneigh_entry *n;
680 int ret = -1;
681
682 read_lock_bh(&nd_tbl.lock);
683 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
684 if (n)
685 ret = !!(n->flags & NTF_ROUTER);
686 read_unlock_bh(&nd_tbl.lock);
687
688 return ret;
689}
690
691static void ndisc_recv_ns(struct sk_buff *skb)
692{
693 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
694 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
695 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
696 u8 *lladdr = NULL;
697 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
698 offsetof(struct nd_msg, opt));
699 struct ndisc_options ndopts;
700 struct net_device *dev = skb->dev;
701 struct inet6_ifaddr *ifp;
702 struct inet6_dev *idev = NULL;
703 struct neighbour *neigh;
704 int dad = ipv6_addr_any(saddr);
705 bool inc;
706 int is_router = -1;
707
708 if (skb->len < sizeof(struct nd_msg)) {
709 ND_PRINTK(2, warn, "NS: packet too short\n");
710 return;
711 }
712
713 if (ipv6_addr_is_multicast(&msg->target)) {
714 ND_PRINTK(2, warn, "NS: multicast target address\n");
715 return;
716 }
717
718 /*
719 * RFC2461 7.1.1:
720 * DAD has to be destined for solicited node multicast address.
721 */
722 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
723 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
724 return;
725 }
726
727 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
728 ND_PRINTK(2, warn, "NS: invalid ND options\n");
729 return;
730 }
731
732 if (ndopts.nd_opts_src_lladdr) {
733 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
734 if (!lladdr) {
735 ND_PRINTK(2, warn,
736 "NS: invalid link-layer address length\n");
737 return;
738 }
739
740 /* RFC2461 7.1.1:
741 * If the IP source address is the unspecified address,
742 * there MUST NOT be source link-layer address option
743 * in the message.
744 */
745 if (dad) {
746 ND_PRINTK(2, warn,
747 "NS: bad DAD packet (link-layer address option)\n");
748 return;
749 }
750 }
751
752 inc = ipv6_addr_is_multicast(daddr);
753
754 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
755 if (ifp) {
756
757 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
758 if (dad) {
759 /*
760 * We are colliding with another node
761 * who is doing DAD
762 * so fail our DAD process
763 */
764 addrconf_dad_failure(ifp);
765 return;
766 } else {
767 /*
768 * This is not a dad solicitation.
769 * If we are an optimistic node,
770 * we should respond.
771 * Otherwise, we should ignore it.
772 */
773 if (!(ifp->flags & IFA_F_OPTIMISTIC))
774 goto out;
775 }
776 }
777
778 idev = ifp->idev;
779 } else {
780 struct net *net = dev_net(dev);
781
782 idev = in6_dev_get(dev);
783 if (!idev) {
784 /* XXX: count this drop? */
785 return;
786 }
787
788 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
789 (idev->cnf.forwarding &&
790 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
791 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
792 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
793 skb->pkt_type != PACKET_HOST &&
794 inc &&
795 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
796 /*
797 * for anycast or proxy,
798 * sender should delay its response
799 * by a random time between 0 and
800 * MAX_ANYCAST_DELAY_TIME seconds.
801 * (RFC2461) -- yoshfuji
802 */
803 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
804 if (n)
805 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
806 goto out;
807 }
808 } else
809 goto out;
810 }
811
812 if (is_router < 0)
813 is_router = idev->cnf.forwarding;
814
815 if (dad) {
816 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
817 !!is_router, false, (ifp != NULL), true);
818 goto out;
819 }
820
821 if (inc)
822 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
823 else
824 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
825
826 /*
827 * update / create cache entry
828 * for the source address
829 */
830 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
831 !inc || lladdr || !dev->addr_len);
832 if (neigh)
833 neigh_update(neigh, lladdr, NUD_STALE,
834 NEIGH_UPDATE_F_WEAK_OVERRIDE|
835 NEIGH_UPDATE_F_OVERRIDE);
836 if (neigh || !dev->header_ops) {
837 ndisc_send_na(dev, neigh, saddr, &msg->target,
838 !!is_router,
839 true, (ifp != NULL && inc), inc);
840 if (neigh)
841 neigh_release(neigh);
842 }
843
844out:
845 if (ifp)
846 in6_ifa_put(ifp);
847 else
848 in6_dev_put(idev);
849}
850
851static void ndisc_recv_na(struct sk_buff *skb)
852{
853 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
854 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
855 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
856 u8 *lladdr = NULL;
857 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
858 offsetof(struct nd_msg, opt));
859 struct ndisc_options ndopts;
860 struct net_device *dev = skb->dev;
861 struct inet6_ifaddr *ifp;
862 struct neighbour *neigh;
863
864 if (skb->len < sizeof(struct nd_msg)) {
865 ND_PRINTK(2, warn, "NA: packet too short\n");
866 return;
867 }
868
869 if (ipv6_addr_is_multicast(&msg->target)) {
870 ND_PRINTK(2, warn, "NA: target address is multicast\n");
871 return;
872 }
873
874 if (ipv6_addr_is_multicast(daddr) &&
875 msg->icmph.icmp6_solicited) {
876 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
877 return;
878 }
879
880 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
881 ND_PRINTK(2, warn, "NS: invalid ND option\n");
882 return;
883 }
884 if (ndopts.nd_opts_tgt_lladdr) {
885 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
886 if (!lladdr) {
887 ND_PRINTK(2, warn,
888 "NA: invalid link-layer address length\n");
889 return;
890 }
891 }
892 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
893 if (ifp) {
894 if (skb->pkt_type != PACKET_LOOPBACK
895 && (ifp->flags & IFA_F_TENTATIVE)) {
896 addrconf_dad_failure(ifp);
897 return;
898 }
899 /* What should we make now? The advertisement
900 is invalid, but ndisc specs say nothing
901 about it. It could be misconfiguration, or
902 an smart proxy agent tries to help us :-)
903
904 We should not print the error if NA has been
905 received from loopback - it is just our own
906 unsolicited advertisement.
907 */
908 if (skb->pkt_type != PACKET_LOOPBACK)
909 ND_PRINTK(1, warn,
910 "NA: someone advertises our address %pI6 on %s!\n",
911 &ifp->addr, ifp->idev->dev->name);
912 in6_ifa_put(ifp);
913 return;
914 }
915 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
916
917 if (neigh) {
918 u8 old_flags = neigh->flags;
919 struct net *net = dev_net(dev);
920
921 if (neigh->nud_state & NUD_FAILED)
922 goto out;
923
924 /*
925 * Don't update the neighbor cache entry on a proxy NA from
926 * ourselves because either the proxied node is off link or it
927 * has already sent a NA to us.
928 */
929 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
930 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
931 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
932 /* XXX: idev->cnf.proxy_ndp */
933 goto out;
934 }
935
936 neigh_update(neigh, lladdr,
937 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
938 NEIGH_UPDATE_F_WEAK_OVERRIDE|
939 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
940 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
941 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
942
943 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
944 /*
945 * Change: router to host
946 */
947 rt6_clean_tohost(dev_net(dev), saddr);
948 }
949
950out:
951 neigh_release(neigh);
952 }
953}
954
955static void ndisc_recv_rs(struct sk_buff *skb)
956{
957 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
958 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
959 struct neighbour *neigh;
960 struct inet6_dev *idev;
961 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
962 struct ndisc_options ndopts;
963 u8 *lladdr = NULL;
964
965 if (skb->len < sizeof(*rs_msg))
966 return;
967
968 idev = __in6_dev_get(skb->dev);
969 if (!idev) {
970 ND_PRINTK(1, err, "RS: can't find in6 device\n");
971 return;
972 }
973
974 /* Don't accept RS if we're not in router mode */
975 if (!idev->cnf.forwarding)
976 goto out;
977
978 /*
979 * Don't update NCE if src = ::;
980 * this implies that the source node has no ip address assigned yet.
981 */
982 if (ipv6_addr_any(saddr))
983 goto out;
984
985 /* Parse ND options */
986 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
987 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
988 goto out;
989 }
990
991 if (ndopts.nd_opts_src_lladdr) {
992 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
993 skb->dev);
994 if (!lladdr)
995 goto out;
996 }
997
998 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
999 if (neigh) {
1000 neigh_update(neigh, lladdr, NUD_STALE,
1001 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1002 NEIGH_UPDATE_F_OVERRIDE|
1003 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1004 neigh_release(neigh);
1005 }
1006out:
1007 return;
1008}
1009
1010static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1011{
1012 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1013 struct sk_buff *skb;
1014 struct nlmsghdr *nlh;
1015 struct nduseroptmsg *ndmsg;
1016 struct net *net = dev_net(ra->dev);
1017 int err;
1018 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1019 + (opt->nd_opt_len << 3));
1020 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1021
1022 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1023 if (skb == NULL) {
1024 err = -ENOBUFS;
1025 goto errout;
1026 }
1027
1028 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1029 if (nlh == NULL) {
1030 goto nla_put_failure;
1031 }
1032
1033 ndmsg = nlmsg_data(nlh);
1034 ndmsg->nduseropt_family = AF_INET6;
1035 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1036 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1037 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1038 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1039
1040 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1041
1042 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1043 &ipv6_hdr(ra)->saddr))
1044 goto nla_put_failure;
1045 nlmsg_end(skb, nlh);
1046
1047 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1048 return;
1049
1050nla_put_failure:
1051 nlmsg_free(skb);
1052 err = -EMSGSIZE;
1053errout:
1054 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1055}
1056
1057static void ndisc_router_discovery(struct sk_buff *skb)
1058{
1059 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1060 struct neighbour *neigh = NULL;
1061 struct inet6_dev *in6_dev;
1062 struct rt6_info *rt = NULL;
1063 int lifetime;
1064 struct ndisc_options ndopts;
1065 int optlen;
1066 unsigned int pref = 0;
1067
1068 __u8 * opt = (__u8 *)(ra_msg + 1);
1069
1070 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1071 sizeof(struct ra_msg);
1072
1073 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1074 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1075 return;
1076 }
1077 if (optlen < 0) {
1078 ND_PRINTK(2, warn, "RA: packet too short\n");
1079 return;
1080 }
1081
1082#ifdef CONFIG_IPV6_NDISC_NODETYPE
1083 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1084 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1085 return;
1086 }
1087#endif
1088
1089 /*
1090 * set the RA_RECV flag in the interface
1091 */
1092
1093 in6_dev = __in6_dev_get(skb->dev);
1094 if (in6_dev == NULL) {
1095 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1096 skb->dev->name);
1097 return;
1098 }
1099
1100 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1101 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1102 return;
1103 }
1104
1105 if (!ipv6_accept_ra(in6_dev))
1106 goto skip_linkparms;
1107
1108#ifdef CONFIG_IPV6_NDISC_NODETYPE
1109 /* skip link-specific parameters from interior routers */
1110 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1111 goto skip_linkparms;
1112#endif
1113
1114 if (in6_dev->if_flags & IF_RS_SENT) {
1115 /*
1116 * flag that an RA was received after an RS was sent
1117 * out on this interface.
1118 */
1119 in6_dev->if_flags |= IF_RA_RCVD;
1120 }
1121
1122 /*
1123 * Remember the managed/otherconf flags from most recently
1124 * received RA message (RFC 2462) -- yoshfuji
1125 */
1126 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1127 IF_RA_OTHERCONF)) |
1128 (ra_msg->icmph.icmp6_addrconf_managed ?
1129 IF_RA_MANAGED : 0) |
1130 (ra_msg->icmph.icmp6_addrconf_other ?
1131 IF_RA_OTHERCONF : 0);
1132
1133 if (!in6_dev->cnf.accept_ra_defrtr)
1134 goto skip_defrtr;
1135
1136 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1137 goto skip_defrtr;
1138
1139 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1140
1141#ifdef CONFIG_IPV6_ROUTER_PREF
1142 pref = ra_msg->icmph.icmp6_router_pref;
1143 /* 10b is handled as if it were 00b (medium) */
1144 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1145 !in6_dev->cnf.accept_ra_rtr_pref)
1146 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1147#endif
1148
1149 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1150
1151 if (rt) {
1152 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1153 if (!neigh) {
1154 ND_PRINTK(0, err,
1155 "RA: %s got default router without neighbour\n",
1156 __func__);
1157 ip6_rt_put(rt);
1158 return;
1159 }
1160 }
1161 if (rt && lifetime == 0) {
1162 ip6_del_rt(rt);
1163 rt = NULL;
1164 }
1165
1166 if (rt == NULL && lifetime) {
1167 ND_PRINTK(3, dbg, "RA: adding default router\n");
1168
1169 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1170 if (rt == NULL) {
1171 ND_PRINTK(0, err,
1172 "RA: %s failed to add default route\n",
1173 __func__);
1174 return;
1175 }
1176
1177 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1178 if (neigh == NULL) {
1179 ND_PRINTK(0, err,
1180 "RA: %s got default router without neighbour\n",
1181 __func__);
1182 ip6_rt_put(rt);
1183 return;
1184 }
1185 neigh->flags |= NTF_ROUTER;
1186 } else if (rt) {
1187 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1188 }
1189
1190 if (rt)
1191 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1192 if (ra_msg->icmph.icmp6_hop_limit) {
1193 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1194 if (rt)
1195 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1196 ra_msg->icmph.icmp6_hop_limit);
1197 }
1198
1199skip_defrtr:
1200
1201 /*
1202 * Update Reachable Time and Retrans Timer
1203 */
1204
1205 if (in6_dev->nd_parms) {
1206 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1207
1208 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1209 rtime = (rtime*HZ)/1000;
1210 if (rtime < HZ/10)
1211 rtime = HZ/10;
1212 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1213 in6_dev->tstamp = jiffies;
1214 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1215 }
1216
1217 rtime = ntohl(ra_msg->reachable_time);
1218 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1219 rtime = (rtime*HZ)/1000;
1220
1221 if (rtime < HZ/10)
1222 rtime = HZ/10;
1223
1224 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1225 NEIGH_VAR_SET(in6_dev->nd_parms,
1226 BASE_REACHABLE_TIME, rtime);
1227 NEIGH_VAR_SET(in6_dev->nd_parms,
1228 GC_STALETIME, 3 * rtime);
1229 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1230 in6_dev->tstamp = jiffies;
1231 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1232 }
1233 }
1234 }
1235
1236skip_linkparms:
1237
1238 /*
1239 * Process options.
1240 */
1241
1242 if (!neigh)
1243 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1244 skb->dev, 1);
1245 if (neigh) {
1246 u8 *lladdr = NULL;
1247 if (ndopts.nd_opts_src_lladdr) {
1248 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1249 skb->dev);
1250 if (!lladdr) {
1251 ND_PRINTK(2, warn,
1252 "RA: invalid link-layer address length\n");
1253 goto out;
1254 }
1255 }
1256 neigh_update(neigh, lladdr, NUD_STALE,
1257 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1258 NEIGH_UPDATE_F_OVERRIDE|
1259 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1260 NEIGH_UPDATE_F_ISROUTER);
1261 }
1262
1263 if (!ipv6_accept_ra(in6_dev))
1264 goto out;
1265
1266#ifdef CONFIG_IPV6_ROUTE_INFO
1267 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1268 goto skip_routeinfo;
1269
1270 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1271 struct nd_opt_hdr *p;
1272 for (p = ndopts.nd_opts_ri;
1273 p;
1274 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1275 struct route_info *ri = (struct route_info *)p;
1276#ifdef CONFIG_IPV6_NDISC_NODETYPE
1277 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1278 ri->prefix_len == 0)
1279 continue;
1280#endif
1281 if (ri->prefix_len == 0 &&
1282 !in6_dev->cnf.accept_ra_defrtr)
1283 continue;
1284 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1285 continue;
1286 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1287 &ipv6_hdr(skb)->saddr);
1288 }
1289 }
1290
1291skip_routeinfo:
1292#endif
1293
1294#ifdef CONFIG_IPV6_NDISC_NODETYPE
1295 /* skip link-specific ndopts from interior routers */
1296 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1297 goto out;
1298#endif
1299
1300 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1301 struct nd_opt_hdr *p;
1302 for (p = ndopts.nd_opts_pi;
1303 p;
1304 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1305 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1306 (p->nd_opt_len) << 3,
1307 ndopts.nd_opts_src_lladdr != NULL);
1308 }
1309 }
1310
1311 if (ndopts.nd_opts_mtu) {
1312 __be32 n;
1313 u32 mtu;
1314
1315 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1316 mtu = ntohl(n);
1317
1318 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1319 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1320 } else if (in6_dev->cnf.mtu6 != mtu) {
1321 in6_dev->cnf.mtu6 = mtu;
1322
1323 if (rt)
1324 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1325
1326 rt6_mtu_change(skb->dev, mtu);
1327 }
1328 }
1329
1330 if (ndopts.nd_useropts) {
1331 struct nd_opt_hdr *p;
1332 for (p = ndopts.nd_useropts;
1333 p;
1334 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1335 ndisc_ra_useropt(skb, p);
1336 }
1337 }
1338
1339 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1340 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1341 }
1342out:
1343 ip6_rt_put(rt);
1344 if (neigh)
1345 neigh_release(neigh);
1346}
1347
1348static void ndisc_redirect_rcv(struct sk_buff *skb)
1349{
1350 u8 *hdr;
1351 struct ndisc_options ndopts;
1352 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1353 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1354 offsetof(struct rd_msg, opt));
1355
1356#ifdef CONFIG_IPV6_NDISC_NODETYPE
1357 switch (skb->ndisc_nodetype) {
1358 case NDISC_NODETYPE_HOST:
1359 case NDISC_NODETYPE_NODEFAULT:
1360 ND_PRINTK(2, warn,
1361 "Redirect: from host or unauthorized router\n");
1362 return;
1363 }
1364#endif
1365
1366 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1367 ND_PRINTK(2, warn,
1368 "Redirect: source address is not link-local\n");
1369 return;
1370 }
1371
1372 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
1373 return;
1374
1375 if (!ndopts.nd_opts_rh) {
1376 ip6_redirect_no_header(skb, dev_net(skb->dev),
1377 skb->dev->ifindex, 0);
1378 return;
1379 }
1380
1381 hdr = (u8 *)ndopts.nd_opts_rh;
1382 hdr += 8;
1383 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1384 return;
1385
1386 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1387}
1388
1389static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1390 struct sk_buff *orig_skb,
1391 int rd_len)
1392{
1393 u8 *opt = skb_put(skb, rd_len);
1394
1395 memset(opt, 0, 8);
1396 *(opt++) = ND_OPT_REDIRECT_HDR;
1397 *(opt++) = (rd_len >> 3);
1398 opt += 6;
1399
1400 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
1401}
1402
1403void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1404{
1405 struct net_device *dev = skb->dev;
1406 struct net *net = dev_net(dev);
1407 struct sock *sk = net->ipv6.ndisc_sk;
1408 int optlen = 0;
1409 struct inet_peer *peer;
1410 struct sk_buff *buff;
1411 struct rd_msg *msg;
1412 struct in6_addr saddr_buf;
1413 struct rt6_info *rt;
1414 struct dst_entry *dst;
1415 struct flowi6 fl6;
1416 int rd_len;
1417 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1418 bool ret;
1419
1420 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1421 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1422 dev->name);
1423 return;
1424 }
1425
1426 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1427 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1428 ND_PRINTK(2, warn,
1429 "Redirect: target address is not link-local unicast\n");
1430 return;
1431 }
1432
1433 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1434 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1435
1436 dst = ip6_route_output(net, NULL, &fl6);
1437 if (dst->error) {
1438 dst_release(dst);
1439 return;
1440 }
1441 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1442 if (IS_ERR(dst))
1443 return;
1444
1445 rt = (struct rt6_info *) dst;
1446
1447 if (rt->rt6i_flags & RTF_GATEWAY) {
1448 ND_PRINTK(2, warn,
1449 "Redirect: destination is not a neighbour\n");
1450 goto release;
1451 }
1452 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
1453 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1454 if (peer)
1455 inet_putpeer(peer);
1456 if (!ret)
1457 goto release;
1458
1459 if (dev->addr_len) {
1460 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1461 if (!neigh) {
1462 ND_PRINTK(2, warn,
1463 "Redirect: no neigh for target address\n");
1464 goto release;
1465 }
1466
1467 read_lock_bh(&neigh->lock);
1468 if (neigh->nud_state & NUD_VALID) {
1469 memcpy(ha_buf, neigh->ha, dev->addr_len);
1470 read_unlock_bh(&neigh->lock);
1471 ha = ha_buf;
1472 optlen += ndisc_opt_addr_space(dev);
1473 } else
1474 read_unlock_bh(&neigh->lock);
1475
1476 neigh_release(neigh);
1477 }
1478
1479 rd_len = min_t(unsigned int,
1480 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1481 skb->len + 8);
1482 rd_len &= ~0x7;
1483 optlen += rd_len;
1484
1485 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1486 if (!buff)
1487 goto release;
1488
1489 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1490 *msg = (struct rd_msg) {
1491 .icmph = {
1492 .icmp6_type = NDISC_REDIRECT,
1493 },
1494 .target = *target,
1495 .dest = ipv6_hdr(skb)->daddr,
1496 };
1497
1498 /*
1499 * include target_address option
1500 */
1501
1502 if (ha)
1503 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
1504
1505 /*
1506 * build redirect option and copy skb over to the new packet.
1507 */
1508
1509 if (rd_len)
1510 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1511
1512 skb_dst_set(buff, dst);
1513 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1514 return;
1515
1516release:
1517 dst_release(dst);
1518}
1519
1520static void pndisc_redo(struct sk_buff *skb)
1521{
1522 ndisc_recv_ns(skb);
1523 kfree_skb(skb);
1524}
1525
1526static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1527{
1528 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1529
1530 if (!idev)
1531 return true;
1532 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1533 idev->cnf.suppress_frag_ndisc) {
1534 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1535 return true;
1536 }
1537 return false;
1538}
1539
1540int ndisc_rcv(struct sk_buff *skb)
1541{
1542 struct nd_msg *msg;
1543
1544 if (ndisc_suppress_frag_ndisc(skb))
1545 return 0;
1546
1547 if (skb_linearize(skb))
1548 return 0;
1549
1550 msg = (struct nd_msg *)skb_transport_header(skb);
1551
1552 __skb_push(skb, skb->data - skb_transport_header(skb));
1553
1554 if (ipv6_hdr(skb)->hop_limit != 255) {
1555 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1556 ipv6_hdr(skb)->hop_limit);
1557 return 0;
1558 }
1559
1560 if (msg->icmph.icmp6_code != 0) {
1561 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1562 msg->icmph.icmp6_code);
1563 return 0;
1564 }
1565
1566 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1567
1568 switch (msg->icmph.icmp6_type) {
1569 case NDISC_NEIGHBOUR_SOLICITATION:
1570 ndisc_recv_ns(skb);
1571 break;
1572
1573 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1574 ndisc_recv_na(skb);
1575 break;
1576
1577 case NDISC_ROUTER_SOLICITATION:
1578 ndisc_recv_rs(skb);
1579 break;
1580
1581 case NDISC_ROUTER_ADVERTISEMENT:
1582 ndisc_router_discovery(skb);
1583 break;
1584
1585 case NDISC_REDIRECT:
1586 ndisc_redirect_rcv(skb);
1587 break;
1588 }
1589
1590 return 0;
1591}
1592
1593static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1594{
1595 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1596 struct net *net = dev_net(dev);
1597 struct inet6_dev *idev;
1598
1599 switch (event) {
1600 case NETDEV_CHANGEADDR:
1601 neigh_changeaddr(&nd_tbl, dev);
1602 fib6_run_gc(0, net, false);
1603 idev = in6_dev_get(dev);
1604 if (!idev)
1605 break;
1606 if (idev->cnf.ndisc_notify)
1607 ndisc_send_unsol_na(dev);
1608 in6_dev_put(idev);
1609 break;
1610 case NETDEV_DOWN:
1611 neigh_ifdown(&nd_tbl, dev);
1612 fib6_run_gc(0, net, false);
1613 break;
1614 case NETDEV_NOTIFY_PEERS:
1615 ndisc_send_unsol_na(dev);
1616 break;
1617 default:
1618 break;
1619 }
1620
1621 return NOTIFY_DONE;
1622}
1623
1624static struct notifier_block ndisc_netdev_notifier = {
1625 .notifier_call = ndisc_netdev_event,
1626};
1627
1628#ifdef CONFIG_SYSCTL
1629static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1630 const char *func, const char *dev_name)
1631{
1632 static char warncomm[TASK_COMM_LEN];
1633 static int warned;
1634 if (strcmp(warncomm, current->comm) && warned < 5) {
1635 strcpy(warncomm, current->comm);
1636 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1637 warncomm, func,
1638 dev_name, ctl->procname,
1639 dev_name, ctl->procname);
1640 warned++;
1641 }
1642}
1643
1644int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1645{
1646 struct net_device *dev = ctl->extra1;
1647 struct inet6_dev *idev;
1648 int ret;
1649
1650 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1651 (strcmp(ctl->procname, "base_reachable_time") == 0))
1652 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1653
1654 if (strcmp(ctl->procname, "retrans_time") == 0)
1655 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1656
1657 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1658 ret = neigh_proc_dointvec_jiffies(ctl, write,
1659 buffer, lenp, ppos);
1660
1661 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1662 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1663 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1664 buffer, lenp, ppos);
1665 else
1666 ret = -1;
1667
1668 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1669 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1670 idev->nd_parms->reachable_time =
1671 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1672 idev->tstamp = jiffies;
1673 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1674 in6_dev_put(idev);
1675 }
1676 return ret;
1677}
1678
1679
1680#endif
1681
1682static int __net_init ndisc_net_init(struct net *net)
1683{
1684 struct ipv6_pinfo *np;
1685 struct sock *sk;
1686 int err;
1687
1688 err = inet_ctl_sock_create(&sk, PF_INET6,
1689 SOCK_RAW, IPPROTO_ICMPV6, net);
1690 if (err < 0) {
1691 ND_PRINTK(0, err,
1692 "NDISC: Failed to initialize the control socket (err %d)\n",
1693 err);
1694 return err;
1695 }
1696
1697 net->ipv6.ndisc_sk = sk;
1698
1699 np = inet6_sk(sk);
1700 np->hop_limit = 255;
1701 /* Do not loopback ndisc messages */
1702 np->mc_loop = 0;
1703
1704 return 0;
1705}
1706
1707static void __net_exit ndisc_net_exit(struct net *net)
1708{
1709 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1710}
1711
1712static struct pernet_operations ndisc_net_ops = {
1713 .init = ndisc_net_init,
1714 .exit = ndisc_net_exit,
1715};
1716
1717int __init ndisc_init(void)
1718{
1719 int err;
1720
1721 err = register_pernet_subsys(&ndisc_net_ops);
1722 if (err)
1723 return err;
1724 /*
1725 * Initialize the neighbour table
1726 */
1727 neigh_table_init(&nd_tbl);
1728
1729#ifdef CONFIG_SYSCTL
1730 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1731 &ndisc_ifinfo_sysctl_change);
1732 if (err)
1733 goto out_unregister_pernet;
1734out:
1735#endif
1736 return err;
1737
1738#ifdef CONFIG_SYSCTL
1739out_unregister_pernet:
1740 unregister_pernet_subsys(&ndisc_net_ops);
1741 goto out;
1742#endif
1743}
1744
1745int __init ndisc_late_init(void)
1746{
1747 return register_netdevice_notifier(&ndisc_netdev_notifier);
1748}
1749
1750void ndisc_late_cleanup(void)
1751{
1752 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1753}
1754
1755void ndisc_cleanup(void)
1756{
1757#ifdef CONFIG_SYSCTL
1758 neigh_sysctl_unregister(&nd_tbl.parms);
1759#endif
1760 neigh_table_clear(&nd_tbl);
1761 unregister_pernet_subsys(&ndisc_net_ops);
1762}