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1/*
2 * Neighbour Discovery for IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Mike Shaver <shaver@ingenia.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15/*
16 * Changes:
17 *
18 * Pierre Ynard : export userland ND options
19 * through netlink (RDNSS support)
20 * Lars Fenneberg : fixed MTU setting on receipt
21 * of an RA.
22 * Janos Farkas : kmalloc failure checks
23 * Alexey Kuznetsov : state machine reworked
24 * and moved to net/core.
25 * Pekka Savola : RFC2461 validation
26 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
27 */
28
29/* Set to 3 to get tracing... */
30#define ND_DEBUG 1
31
32#define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
33#define ND_NOPRINTK(x...) do { ; } while(0)
34#define ND_PRINTK0 ND_PRINTK
35#define ND_PRINTK1 ND_NOPRINTK
36#define ND_PRINTK2 ND_NOPRINTK
37#define ND_PRINTK3 ND_NOPRINTK
38#if ND_DEBUG >= 1
39#undef ND_PRINTK1
40#define ND_PRINTK1 ND_PRINTK
41#endif
42#if ND_DEBUG >= 2
43#undef ND_PRINTK2
44#define ND_PRINTK2 ND_PRINTK
45#endif
46#if ND_DEBUG >= 3
47#undef ND_PRINTK3
48#define ND_PRINTK3 ND_PRINTK
49#endif
50
51#include <linux/module.h>
52#include <linux/errno.h>
53#include <linux/types.h>
54#include <linux/socket.h>
55#include <linux/sockios.h>
56#include <linux/sched.h>
57#include <linux/net.h>
58#include <linux/in6.h>
59#include <linux/route.h>
60#include <linux/init.h>
61#include <linux/rcupdate.h>
62#include <linux/slab.h>
63#ifdef CONFIG_SYSCTL
64#include <linux/sysctl.h>
65#endif
66
67#include <linux/if_addr.h>
68#include <linux/if_arp.h>
69#include <linux/ipv6.h>
70#include <linux/icmpv6.h>
71#include <linux/jhash.h>
72
73#include <net/sock.h>
74#include <net/snmp.h>
75
76#include <net/ipv6.h>
77#include <net/protocol.h>
78#include <net/ndisc.h>
79#include <net/ip6_route.h>
80#include <net/addrconf.h>
81#include <net/icmp.h>
82
83#include <net/netlink.h>
84#include <linux/rtnetlink.h>
85
86#include <net/flow.h>
87#include <net/ip6_checksum.h>
88#include <net/inet_common.h>
89#include <linux/proc_fs.h>
90
91#include <linux/netfilter.h>
92#include <linux/netfilter_ipv6.h>
93
94static u32 ndisc_hash(const void *pkey,
95 const struct net_device *dev,
96 __u32 rnd);
97static int ndisc_constructor(struct neighbour *neigh);
98static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
99static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
100static int pndisc_constructor(struct pneigh_entry *n);
101static void pndisc_destructor(struct pneigh_entry *n);
102static void pndisc_redo(struct sk_buff *skb);
103
104static const struct neigh_ops ndisc_generic_ops = {
105 .family = AF_INET6,
106 .solicit = ndisc_solicit,
107 .error_report = ndisc_error_report,
108 .output = neigh_resolve_output,
109 .connected_output = neigh_connected_output,
110};
111
112static const struct neigh_ops ndisc_hh_ops = {
113 .family = AF_INET6,
114 .solicit = ndisc_solicit,
115 .error_report = ndisc_error_report,
116 .output = neigh_resolve_output,
117 .connected_output = neigh_resolve_output,
118};
119
120
121static const struct neigh_ops ndisc_direct_ops = {
122 .family = AF_INET6,
123 .output = neigh_direct_output,
124 .connected_output = neigh_direct_output,
125};
126
127struct neigh_table nd_tbl = {
128 .family = AF_INET6,
129 .entry_size = sizeof(struct neighbour) + sizeof(struct in6_addr),
130 .key_len = sizeof(struct in6_addr),
131 .hash = ndisc_hash,
132 .constructor = ndisc_constructor,
133 .pconstructor = pndisc_constructor,
134 .pdestructor = pndisc_destructor,
135 .proxy_redo = pndisc_redo,
136 .id = "ndisc_cache",
137 .parms = {
138 .tbl = &nd_tbl,
139 .base_reachable_time = ND_REACHABLE_TIME,
140 .retrans_time = ND_RETRANS_TIMER,
141 .gc_staletime = 60 * HZ,
142 .reachable_time = ND_REACHABLE_TIME,
143 .delay_probe_time = 5 * HZ,
144 .queue_len = 3,
145 .ucast_probes = 3,
146 .mcast_probes = 3,
147 .anycast_delay = 1 * HZ,
148 .proxy_delay = (8 * HZ) / 10,
149 .proxy_qlen = 64,
150 },
151 .gc_interval = 30 * HZ,
152 .gc_thresh1 = 128,
153 .gc_thresh2 = 512,
154 .gc_thresh3 = 1024,
155};
156
157/* ND options */
158struct ndisc_options {
159 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
160#ifdef CONFIG_IPV6_ROUTE_INFO
161 struct nd_opt_hdr *nd_opts_ri;
162 struct nd_opt_hdr *nd_opts_ri_end;
163#endif
164 struct nd_opt_hdr *nd_useropts;
165 struct nd_opt_hdr *nd_useropts_end;
166};
167
168#define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
169#define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR]
170#define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO]
171#define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
172#define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
173#define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
174
175#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
176
177/*
178 * Return the padding between the option length and the start of the
179 * link addr. Currently only IP-over-InfiniBand needs this, although
180 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
181 * also need a pad of 2.
182 */
183static int ndisc_addr_option_pad(unsigned short type)
184{
185 switch (type) {
186 case ARPHRD_INFINIBAND: return 2;
187 default: return 0;
188 }
189}
190
191static inline int ndisc_opt_addr_space(struct net_device *dev)
192{
193 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
194}
195
196static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
197 unsigned short addr_type)
198{
199 int space = NDISC_OPT_SPACE(data_len);
200 int pad = ndisc_addr_option_pad(addr_type);
201
202 opt[0] = type;
203 opt[1] = space>>3;
204
205 memset(opt + 2, 0, pad);
206 opt += pad;
207 space -= pad;
208
209 memcpy(opt+2, data, data_len);
210 data_len += 2;
211 opt += data_len;
212 if ((space -= data_len) > 0)
213 memset(opt, 0, space);
214 return opt + space;
215}
216
217static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
218 struct nd_opt_hdr *end)
219{
220 int type;
221 if (!cur || !end || cur >= end)
222 return NULL;
223 type = cur->nd_opt_type;
224 do {
225 cur = ((void *)cur) + (cur->nd_opt_len << 3);
226 } while(cur < end && cur->nd_opt_type != type);
227 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
228}
229
230static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
231{
232 return opt->nd_opt_type == ND_OPT_RDNSS;
233}
234
235static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
236 struct nd_opt_hdr *end)
237{
238 if (!cur || !end || cur >= end)
239 return NULL;
240 do {
241 cur = ((void *)cur) + (cur->nd_opt_len << 3);
242 } while(cur < end && !ndisc_is_useropt(cur));
243 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
244}
245
246static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
247 struct ndisc_options *ndopts)
248{
249 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
250
251 if (!nd_opt || opt_len < 0 || !ndopts)
252 return NULL;
253 memset(ndopts, 0, sizeof(*ndopts));
254 while (opt_len) {
255 int l;
256 if (opt_len < sizeof(struct nd_opt_hdr))
257 return NULL;
258 l = nd_opt->nd_opt_len << 3;
259 if (opt_len < l || l == 0)
260 return NULL;
261 switch (nd_opt->nd_opt_type) {
262 case ND_OPT_SOURCE_LL_ADDR:
263 case ND_OPT_TARGET_LL_ADDR:
264 case ND_OPT_MTU:
265 case ND_OPT_REDIRECT_HDR:
266 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
267 ND_PRINTK2(KERN_WARNING
268 "%s(): duplicated ND6 option found: type=%d\n",
269 __func__,
270 nd_opt->nd_opt_type);
271 } else {
272 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
273 }
274 break;
275 case ND_OPT_PREFIX_INFO:
276 ndopts->nd_opts_pi_end = nd_opt;
277 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
278 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
279 break;
280#ifdef CONFIG_IPV6_ROUTE_INFO
281 case ND_OPT_ROUTE_INFO:
282 ndopts->nd_opts_ri_end = nd_opt;
283 if (!ndopts->nd_opts_ri)
284 ndopts->nd_opts_ri = nd_opt;
285 break;
286#endif
287 default:
288 if (ndisc_is_useropt(nd_opt)) {
289 ndopts->nd_useropts_end = nd_opt;
290 if (!ndopts->nd_useropts)
291 ndopts->nd_useropts = nd_opt;
292 } else {
293 /*
294 * Unknown options must be silently ignored,
295 * to accommodate future extension to the
296 * protocol.
297 */
298 ND_PRINTK2(KERN_NOTICE
299 "%s(): ignored unsupported option; type=%d, len=%d\n",
300 __func__,
301 nd_opt->nd_opt_type, nd_opt->nd_opt_len);
302 }
303 }
304 opt_len -= l;
305 nd_opt = ((void *)nd_opt) + l;
306 }
307 return ndopts;
308}
309
310static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
311 struct net_device *dev)
312{
313 u8 *lladdr = (u8 *)(p + 1);
314 int lladdrlen = p->nd_opt_len << 3;
315 int prepad = ndisc_addr_option_pad(dev->type);
316 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
317 return NULL;
318 return lladdr + prepad;
319}
320
321int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
322{
323 switch (dev->type) {
324 case ARPHRD_ETHER:
325 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
326 case ARPHRD_FDDI:
327 ipv6_eth_mc_map(addr, buf);
328 return 0;
329 case ARPHRD_IEEE802_TR:
330 ipv6_tr_mc_map(addr,buf);
331 return 0;
332 case ARPHRD_ARCNET:
333 ipv6_arcnet_mc_map(addr, buf);
334 return 0;
335 case ARPHRD_INFINIBAND:
336 ipv6_ib_mc_map(addr, dev->broadcast, buf);
337 return 0;
338 case ARPHRD_IPGRE:
339 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
340 default:
341 if (dir) {
342 memcpy(buf, dev->broadcast, dev->addr_len);
343 return 0;
344 }
345 }
346 return -EINVAL;
347}
348
349EXPORT_SYMBOL(ndisc_mc_map);
350
351static u32 ndisc_hash(const void *pkey,
352 const struct net_device *dev,
353 __u32 hash_rnd)
354{
355 const u32 *p32 = pkey;
356 u32 addr_hash, i;
357
358 addr_hash = 0;
359 for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
360 addr_hash ^= *p32++;
361
362 return jhash_2words(addr_hash, dev->ifindex, hash_rnd);
363}
364
365static int ndisc_constructor(struct neighbour *neigh)
366{
367 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
368 struct net_device *dev = neigh->dev;
369 struct inet6_dev *in6_dev;
370 struct neigh_parms *parms;
371 int is_multicast = ipv6_addr_is_multicast(addr);
372
373 rcu_read_lock();
374 in6_dev = in6_dev_get(dev);
375 if (in6_dev == NULL) {
376 rcu_read_unlock();
377 return -EINVAL;
378 }
379
380 parms = in6_dev->nd_parms;
381 __neigh_parms_put(neigh->parms);
382 neigh->parms = neigh_parms_clone(parms);
383 rcu_read_unlock();
384
385 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
386 if (!dev->header_ops) {
387 neigh->nud_state = NUD_NOARP;
388 neigh->ops = &ndisc_direct_ops;
389 neigh->output = neigh_direct_output;
390 } else {
391 if (is_multicast) {
392 neigh->nud_state = NUD_NOARP;
393 ndisc_mc_map(addr, neigh->ha, dev, 1);
394 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
395 neigh->nud_state = NUD_NOARP;
396 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
397 if (dev->flags&IFF_LOOPBACK)
398 neigh->type = RTN_LOCAL;
399 } else if (dev->flags&IFF_POINTOPOINT) {
400 neigh->nud_state = NUD_NOARP;
401 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
402 }
403 if (dev->header_ops->cache)
404 neigh->ops = &ndisc_hh_ops;
405 else
406 neigh->ops = &ndisc_generic_ops;
407 if (neigh->nud_state&NUD_VALID)
408 neigh->output = neigh->ops->connected_output;
409 else
410 neigh->output = neigh->ops->output;
411 }
412 in6_dev_put(in6_dev);
413 return 0;
414}
415
416static int pndisc_constructor(struct pneigh_entry *n)
417{
418 struct in6_addr *addr = (struct in6_addr*)&n->key;
419 struct in6_addr maddr;
420 struct net_device *dev = n->dev;
421
422 if (dev == NULL || __in6_dev_get(dev) == NULL)
423 return -EINVAL;
424 addrconf_addr_solict_mult(addr, &maddr);
425 ipv6_dev_mc_inc(dev, &maddr);
426 return 0;
427}
428
429static void pndisc_destructor(struct pneigh_entry *n)
430{
431 struct in6_addr *addr = (struct in6_addr*)&n->key;
432 struct in6_addr maddr;
433 struct net_device *dev = n->dev;
434
435 if (dev == NULL || __in6_dev_get(dev) == NULL)
436 return;
437 addrconf_addr_solict_mult(addr, &maddr);
438 ipv6_dev_mc_dec(dev, &maddr);
439}
440
441struct sk_buff *ndisc_build_skb(struct net_device *dev,
442 const struct in6_addr *daddr,
443 const struct in6_addr *saddr,
444 struct icmp6hdr *icmp6h,
445 const struct in6_addr *target,
446 int llinfo)
447{
448 struct net *net = dev_net(dev);
449 struct sock *sk = net->ipv6.ndisc_sk;
450 struct sk_buff *skb;
451 struct icmp6hdr *hdr;
452 int len;
453 int err;
454 u8 *opt;
455
456 if (!dev->addr_len)
457 llinfo = 0;
458
459 len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
460 if (llinfo)
461 len += ndisc_opt_addr_space(dev);
462
463 skb = sock_alloc_send_skb(sk,
464 (MAX_HEADER + sizeof(struct ipv6hdr) +
465 len + LL_ALLOCATED_SPACE(dev)),
466 1, &err);
467 if (!skb) {
468 ND_PRINTK0(KERN_ERR
469 "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
470 __func__, err);
471 return NULL;
472 }
473
474 skb_reserve(skb, LL_RESERVED_SPACE(dev));
475 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
476
477 skb->transport_header = skb->tail;
478 skb_put(skb, len);
479
480 hdr = (struct icmp6hdr *)skb_transport_header(skb);
481 memcpy(hdr, icmp6h, sizeof(*hdr));
482
483 opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
484 if (target) {
485 ipv6_addr_copy((struct in6_addr *)opt, target);
486 opt += sizeof(*target);
487 }
488
489 if (llinfo)
490 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
491 dev->addr_len, dev->type);
492
493 hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
494 IPPROTO_ICMPV6,
495 csum_partial(hdr,
496 len, 0));
497
498 return skb;
499}
500
501EXPORT_SYMBOL(ndisc_build_skb);
502
503void ndisc_send_skb(struct sk_buff *skb,
504 struct net_device *dev,
505 struct neighbour *neigh,
506 const struct in6_addr *daddr,
507 const struct in6_addr *saddr,
508 struct icmp6hdr *icmp6h)
509{
510 struct flowi6 fl6;
511 struct dst_entry *dst;
512 struct net *net = dev_net(dev);
513 struct sock *sk = net->ipv6.ndisc_sk;
514 struct inet6_dev *idev;
515 int err;
516 u8 type;
517
518 type = icmp6h->icmp6_type;
519
520 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, dev->ifindex);
521
522 dst = icmp6_dst_alloc(dev, neigh, daddr);
523 if (!dst) {
524 kfree_skb(skb);
525 return;
526 }
527
528 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
529 if (IS_ERR(dst)) {
530 kfree_skb(skb);
531 return;
532 }
533
534 skb_dst_set(skb, dst);
535
536 idev = in6_dev_get(dst->dev);
537 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
538
539 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
540 dst_output);
541 if (!err) {
542 ICMP6MSGOUT_INC_STATS(net, idev, type);
543 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
544 }
545
546 if (likely(idev != NULL))
547 in6_dev_put(idev);
548}
549
550EXPORT_SYMBOL(ndisc_send_skb);
551
552/*
553 * Send a Neighbour Discover packet
554 */
555static void __ndisc_send(struct net_device *dev,
556 struct neighbour *neigh,
557 const struct in6_addr *daddr,
558 const struct in6_addr *saddr,
559 struct icmp6hdr *icmp6h, const struct in6_addr *target,
560 int llinfo)
561{
562 struct sk_buff *skb;
563
564 skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
565 if (!skb)
566 return;
567
568 ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
569}
570
571static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
572 const struct in6_addr *daddr,
573 const struct in6_addr *solicited_addr,
574 int router, int solicited, int override, int inc_opt)
575{
576 struct in6_addr tmpaddr;
577 struct inet6_ifaddr *ifp;
578 const struct in6_addr *src_addr;
579 struct icmp6hdr icmp6h = {
580 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
581 };
582
583 /* for anycast or proxy, solicited_addr != src_addr */
584 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
585 if (ifp) {
586 src_addr = solicited_addr;
587 if (ifp->flags & IFA_F_OPTIMISTIC)
588 override = 0;
589 inc_opt |= ifp->idev->cnf.force_tllao;
590 in6_ifa_put(ifp);
591 } else {
592 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
593 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
594 &tmpaddr))
595 return;
596 src_addr = &tmpaddr;
597 }
598
599 icmp6h.icmp6_router = router;
600 icmp6h.icmp6_solicited = solicited;
601 icmp6h.icmp6_override = override;
602
603 __ndisc_send(dev, neigh, daddr, src_addr,
604 &icmp6h, solicited_addr,
605 inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
606}
607
608static void ndisc_send_unsol_na(struct net_device *dev)
609{
610 struct inet6_dev *idev;
611 struct inet6_ifaddr *ifa;
612 struct in6_addr mcaddr;
613
614 idev = in6_dev_get(dev);
615 if (!idev)
616 return;
617
618 read_lock_bh(&idev->lock);
619 list_for_each_entry(ifa, &idev->addr_list, if_list) {
620 addrconf_addr_solict_mult(&ifa->addr, &mcaddr);
621 ndisc_send_na(dev, NULL, &mcaddr, &ifa->addr,
622 /*router=*/ !!idev->cnf.forwarding,
623 /*solicited=*/ false, /*override=*/ true,
624 /*inc_opt=*/ true);
625 }
626 read_unlock_bh(&idev->lock);
627
628 in6_dev_put(idev);
629}
630
631void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
632 const struct in6_addr *solicit,
633 const struct in6_addr *daddr, const struct in6_addr *saddr)
634{
635 struct in6_addr addr_buf;
636 struct icmp6hdr icmp6h = {
637 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
638 };
639
640 if (saddr == NULL) {
641 if (ipv6_get_lladdr(dev, &addr_buf,
642 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
643 return;
644 saddr = &addr_buf;
645 }
646
647 __ndisc_send(dev, neigh, daddr, saddr,
648 &icmp6h, solicit,
649 !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
650}
651
652void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
653 const struct in6_addr *daddr)
654{
655 struct icmp6hdr icmp6h = {
656 .icmp6_type = NDISC_ROUTER_SOLICITATION,
657 };
658 int send_sllao = dev->addr_len;
659
660#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
661 /*
662 * According to section 2.2 of RFC 4429, we must not
663 * send router solicitations with a sllao from
664 * optimistic addresses, but we may send the solicitation
665 * if we don't include the sllao. So here we check
666 * if our address is optimistic, and if so, we
667 * suppress the inclusion of the sllao.
668 */
669 if (send_sllao) {
670 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
671 dev, 1);
672 if (ifp) {
673 if (ifp->flags & IFA_F_OPTIMISTIC) {
674 send_sllao = 0;
675 }
676 in6_ifa_put(ifp);
677 } else {
678 send_sllao = 0;
679 }
680 }
681#endif
682 __ndisc_send(dev, NULL, daddr, saddr,
683 &icmp6h, NULL,
684 send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
685}
686
687
688static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
689{
690 /*
691 * "The sender MUST return an ICMP
692 * destination unreachable"
693 */
694 dst_link_failure(skb);
695 kfree_skb(skb);
696}
697
698/* Called with locked neigh: either read or both */
699
700static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
701{
702 struct in6_addr *saddr = NULL;
703 struct in6_addr mcaddr;
704 struct net_device *dev = neigh->dev;
705 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
706 int probes = atomic_read(&neigh->probes);
707
708 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
709 saddr = &ipv6_hdr(skb)->saddr;
710
711 if ((probes -= neigh->parms->ucast_probes) < 0) {
712 if (!(neigh->nud_state & NUD_VALID)) {
713 ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
714 __func__, target);
715 }
716 ndisc_send_ns(dev, neigh, target, target, saddr);
717 } else if ((probes -= neigh->parms->app_probes) < 0) {
718#ifdef CONFIG_ARPD
719 neigh_app_ns(neigh);
720#endif
721 } else {
722 addrconf_addr_solict_mult(target, &mcaddr);
723 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
724 }
725}
726
727static int pndisc_is_router(const void *pkey,
728 struct net_device *dev)
729{
730 struct pneigh_entry *n;
731 int ret = -1;
732
733 read_lock_bh(&nd_tbl.lock);
734 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
735 if (n)
736 ret = !!(n->flags & NTF_ROUTER);
737 read_unlock_bh(&nd_tbl.lock);
738
739 return ret;
740}
741
742static void ndisc_recv_ns(struct sk_buff *skb)
743{
744 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
745 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
746 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
747 u8 *lladdr = NULL;
748 u32 ndoptlen = skb->tail - (skb->transport_header +
749 offsetof(struct nd_msg, opt));
750 struct ndisc_options ndopts;
751 struct net_device *dev = skb->dev;
752 struct inet6_ifaddr *ifp;
753 struct inet6_dev *idev = NULL;
754 struct neighbour *neigh;
755 int dad = ipv6_addr_any(saddr);
756 int inc;
757 int is_router = -1;
758
759 if (ipv6_addr_is_multicast(&msg->target)) {
760 ND_PRINTK2(KERN_WARNING
761 "ICMPv6 NS: multicast target address");
762 return;
763 }
764
765 /*
766 * RFC2461 7.1.1:
767 * DAD has to be destined for solicited node multicast address.
768 */
769 if (dad &&
770 !(daddr->s6_addr32[0] == htonl(0xff020000) &&
771 daddr->s6_addr32[1] == htonl(0x00000000) &&
772 daddr->s6_addr32[2] == htonl(0x00000001) &&
773 daddr->s6_addr [12] == 0xff )) {
774 ND_PRINTK2(KERN_WARNING
775 "ICMPv6 NS: bad DAD packet (wrong destination)\n");
776 return;
777 }
778
779 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
780 ND_PRINTK2(KERN_WARNING
781 "ICMPv6 NS: invalid ND options\n");
782 return;
783 }
784
785 if (ndopts.nd_opts_src_lladdr) {
786 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
787 if (!lladdr) {
788 ND_PRINTK2(KERN_WARNING
789 "ICMPv6 NS: invalid link-layer address length\n");
790 return;
791 }
792
793 /* RFC2461 7.1.1:
794 * If the IP source address is the unspecified address,
795 * there MUST NOT be source link-layer address option
796 * in the message.
797 */
798 if (dad) {
799 ND_PRINTK2(KERN_WARNING
800 "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
801 return;
802 }
803 }
804
805 inc = ipv6_addr_is_multicast(daddr);
806
807 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
808 if (ifp) {
809
810 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
811 if (dad) {
812 if (dev->type == ARPHRD_IEEE802_TR) {
813 const unsigned char *sadr;
814 sadr = skb_mac_header(skb);
815 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
816 sadr[9] == dev->dev_addr[1] &&
817 sadr[10] == dev->dev_addr[2] &&
818 sadr[11] == dev->dev_addr[3] &&
819 sadr[12] == dev->dev_addr[4] &&
820 sadr[13] == dev->dev_addr[5]) {
821 /* looped-back to us */
822 goto out;
823 }
824 }
825
826 /*
827 * We are colliding with another node
828 * who is doing DAD
829 * so fail our DAD process
830 */
831 addrconf_dad_failure(ifp);
832 return;
833 } else {
834 /*
835 * This is not a dad solicitation.
836 * If we are an optimistic node,
837 * we should respond.
838 * Otherwise, we should ignore it.
839 */
840 if (!(ifp->flags & IFA_F_OPTIMISTIC))
841 goto out;
842 }
843 }
844
845 idev = ifp->idev;
846 } else {
847 struct net *net = dev_net(dev);
848
849 idev = in6_dev_get(dev);
850 if (!idev) {
851 /* XXX: count this drop? */
852 return;
853 }
854
855 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
856 (idev->cnf.forwarding &&
857 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
858 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
859 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
860 skb->pkt_type != PACKET_HOST &&
861 inc != 0 &&
862 idev->nd_parms->proxy_delay != 0) {
863 /*
864 * for anycast or proxy,
865 * sender should delay its response
866 * by a random time between 0 and
867 * MAX_ANYCAST_DELAY_TIME seconds.
868 * (RFC2461) -- yoshfuji
869 */
870 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
871 if (n)
872 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
873 goto out;
874 }
875 } else
876 goto out;
877 }
878
879 if (is_router < 0)
880 is_router = !!idev->cnf.forwarding;
881
882 if (dad) {
883 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
884 is_router, 0, (ifp != NULL), 1);
885 goto out;
886 }
887
888 if (inc)
889 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
890 else
891 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
892
893 /*
894 * update / create cache entry
895 * for the source address
896 */
897 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
898 !inc || lladdr || !dev->addr_len);
899 if (neigh)
900 neigh_update(neigh, lladdr, NUD_STALE,
901 NEIGH_UPDATE_F_WEAK_OVERRIDE|
902 NEIGH_UPDATE_F_OVERRIDE);
903 if (neigh || !dev->header_ops) {
904 ndisc_send_na(dev, neigh, saddr, &msg->target,
905 is_router,
906 1, (ifp != NULL && inc), inc);
907 if (neigh)
908 neigh_release(neigh);
909 }
910
911out:
912 if (ifp)
913 in6_ifa_put(ifp);
914 else
915 in6_dev_put(idev);
916}
917
918static void ndisc_recv_na(struct sk_buff *skb)
919{
920 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
921 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
922 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
923 u8 *lladdr = NULL;
924 u32 ndoptlen = skb->tail - (skb->transport_header +
925 offsetof(struct nd_msg, opt));
926 struct ndisc_options ndopts;
927 struct net_device *dev = skb->dev;
928 struct inet6_ifaddr *ifp;
929 struct neighbour *neigh;
930
931 if (skb->len < sizeof(struct nd_msg)) {
932 ND_PRINTK2(KERN_WARNING
933 "ICMPv6 NA: packet too short\n");
934 return;
935 }
936
937 if (ipv6_addr_is_multicast(&msg->target)) {
938 ND_PRINTK2(KERN_WARNING
939 "ICMPv6 NA: target address is multicast.\n");
940 return;
941 }
942
943 if (ipv6_addr_is_multicast(daddr) &&
944 msg->icmph.icmp6_solicited) {
945 ND_PRINTK2(KERN_WARNING
946 "ICMPv6 NA: solicited NA is multicasted.\n");
947 return;
948 }
949
950 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
951 ND_PRINTK2(KERN_WARNING
952 "ICMPv6 NS: invalid ND option\n");
953 return;
954 }
955 if (ndopts.nd_opts_tgt_lladdr) {
956 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
957 if (!lladdr) {
958 ND_PRINTK2(KERN_WARNING
959 "ICMPv6 NA: invalid link-layer address length\n");
960 return;
961 }
962 }
963 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
964 if (ifp) {
965 if (skb->pkt_type != PACKET_LOOPBACK
966 && (ifp->flags & IFA_F_TENTATIVE)) {
967 addrconf_dad_failure(ifp);
968 return;
969 }
970 /* What should we make now? The advertisement
971 is invalid, but ndisc specs say nothing
972 about it. It could be misconfiguration, or
973 an smart proxy agent tries to help us :-)
974
975 We should not print the error if NA has been
976 received from loopback - it is just our own
977 unsolicited advertisement.
978 */
979 if (skb->pkt_type != PACKET_LOOPBACK)
980 ND_PRINTK1(KERN_WARNING
981 "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
982 &ifp->addr, ifp->idev->dev->name);
983 in6_ifa_put(ifp);
984 return;
985 }
986 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
987
988 if (neigh) {
989 u8 old_flags = neigh->flags;
990 struct net *net = dev_net(dev);
991
992 if (neigh->nud_state & NUD_FAILED)
993 goto out;
994
995 /*
996 * Don't update the neighbor cache entry on a proxy NA from
997 * ourselves because either the proxied node is off link or it
998 * has already sent a NA to us.
999 */
1000 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1001 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1002 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1003 /* XXX: idev->cnf.prixy_ndp */
1004 goto out;
1005 }
1006
1007 neigh_update(neigh, lladdr,
1008 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1009 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1010 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1011 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1012 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
1013
1014 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1015 /*
1016 * Change: router to host
1017 */
1018 struct rt6_info *rt;
1019 rt = rt6_get_dflt_router(saddr, dev);
1020 if (rt)
1021 ip6_del_rt(rt);
1022 }
1023
1024out:
1025 neigh_release(neigh);
1026 }
1027}
1028
1029static void ndisc_recv_rs(struct sk_buff *skb)
1030{
1031 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1032 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1033 struct neighbour *neigh;
1034 struct inet6_dev *idev;
1035 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1036 struct ndisc_options ndopts;
1037 u8 *lladdr = NULL;
1038
1039 if (skb->len < sizeof(*rs_msg))
1040 return;
1041
1042 idev = in6_dev_get(skb->dev);
1043 if (!idev) {
1044 if (net_ratelimit())
1045 ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1046 return;
1047 }
1048
1049 /* Don't accept RS if we're not in router mode */
1050 if (!idev->cnf.forwarding)
1051 goto out;
1052
1053 /*
1054 * Don't update NCE if src = ::;
1055 * this implies that the source node has no ip address assigned yet.
1056 */
1057 if (ipv6_addr_any(saddr))
1058 goto out;
1059
1060 /* Parse ND options */
1061 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1062 if (net_ratelimit())
1063 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1064 goto out;
1065 }
1066
1067 if (ndopts.nd_opts_src_lladdr) {
1068 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1069 skb->dev);
1070 if (!lladdr)
1071 goto out;
1072 }
1073
1074 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1075 if (neigh) {
1076 neigh_update(neigh, lladdr, NUD_STALE,
1077 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1078 NEIGH_UPDATE_F_OVERRIDE|
1079 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1080 neigh_release(neigh);
1081 }
1082out:
1083 in6_dev_put(idev);
1084}
1085
1086static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1087{
1088 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1089 struct sk_buff *skb;
1090 struct nlmsghdr *nlh;
1091 struct nduseroptmsg *ndmsg;
1092 struct net *net = dev_net(ra->dev);
1093 int err;
1094 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1095 + (opt->nd_opt_len << 3));
1096 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1097
1098 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1099 if (skb == NULL) {
1100 err = -ENOBUFS;
1101 goto errout;
1102 }
1103
1104 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1105 if (nlh == NULL) {
1106 goto nla_put_failure;
1107 }
1108
1109 ndmsg = nlmsg_data(nlh);
1110 ndmsg->nduseropt_family = AF_INET6;
1111 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1112 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1113 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1114 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1115
1116 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1117
1118 NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1119 &ipv6_hdr(ra)->saddr);
1120 nlmsg_end(skb, nlh);
1121
1122 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1123 return;
1124
1125nla_put_failure:
1126 nlmsg_free(skb);
1127 err = -EMSGSIZE;
1128errout:
1129 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1130}
1131
1132static inline int accept_ra(struct inet6_dev *in6_dev)
1133{
1134 /*
1135 * If forwarding is enabled, RA are not accepted unless the special
1136 * hybrid mode (accept_ra=2) is enabled.
1137 */
1138 if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2)
1139 return 0;
1140
1141 return in6_dev->cnf.accept_ra;
1142}
1143
1144static void ndisc_router_discovery(struct sk_buff *skb)
1145{
1146 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1147 struct neighbour *neigh = NULL;
1148 struct inet6_dev *in6_dev;
1149 struct rt6_info *rt = NULL;
1150 int lifetime;
1151 struct ndisc_options ndopts;
1152 int optlen;
1153 unsigned int pref = 0;
1154
1155 __u8 * opt = (__u8 *)(ra_msg + 1);
1156
1157 optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1158
1159 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1160 ND_PRINTK2(KERN_WARNING
1161 "ICMPv6 RA: source address is not link-local.\n");
1162 return;
1163 }
1164 if (optlen < 0) {
1165 ND_PRINTK2(KERN_WARNING
1166 "ICMPv6 RA: packet too short\n");
1167 return;
1168 }
1169
1170#ifdef CONFIG_IPV6_NDISC_NODETYPE
1171 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1172 ND_PRINTK2(KERN_WARNING
1173 "ICMPv6 RA: from host or unauthorized router\n");
1174 return;
1175 }
1176#endif
1177
1178 /*
1179 * set the RA_RECV flag in the interface
1180 */
1181
1182 in6_dev = in6_dev_get(skb->dev);
1183 if (in6_dev == NULL) {
1184 ND_PRINTK0(KERN_ERR
1185 "ICMPv6 RA: can't find inet6 device for %s.\n",
1186 skb->dev->name);
1187 return;
1188 }
1189
1190 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1191 in6_dev_put(in6_dev);
1192 ND_PRINTK2(KERN_WARNING
1193 "ICMP6 RA: invalid ND options\n");
1194 return;
1195 }
1196
1197 if (!accept_ra(in6_dev))
1198 goto skip_linkparms;
1199
1200#ifdef CONFIG_IPV6_NDISC_NODETYPE
1201 /* skip link-specific parameters from interior routers */
1202 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1203 goto skip_linkparms;
1204#endif
1205
1206 if (in6_dev->if_flags & IF_RS_SENT) {
1207 /*
1208 * flag that an RA was received after an RS was sent
1209 * out on this interface.
1210 */
1211 in6_dev->if_flags |= IF_RA_RCVD;
1212 }
1213
1214 /*
1215 * Remember the managed/otherconf flags from most recently
1216 * received RA message (RFC 2462) -- yoshfuji
1217 */
1218 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1219 IF_RA_OTHERCONF)) |
1220 (ra_msg->icmph.icmp6_addrconf_managed ?
1221 IF_RA_MANAGED : 0) |
1222 (ra_msg->icmph.icmp6_addrconf_other ?
1223 IF_RA_OTHERCONF : 0);
1224
1225 if (!in6_dev->cnf.accept_ra_defrtr)
1226 goto skip_defrtr;
1227
1228 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1229
1230#ifdef CONFIG_IPV6_ROUTER_PREF
1231 pref = ra_msg->icmph.icmp6_router_pref;
1232 /* 10b is handled as if it were 00b (medium) */
1233 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1234 !in6_dev->cnf.accept_ra_rtr_pref)
1235 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1236#endif
1237
1238 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1239
1240 if (rt)
1241 neigh = dst_get_neighbour(&rt->dst);
1242
1243 if (rt && lifetime == 0) {
1244 neigh_clone(neigh);
1245 ip6_del_rt(rt);
1246 rt = NULL;
1247 }
1248
1249 if (rt == NULL && lifetime) {
1250 ND_PRINTK3(KERN_DEBUG
1251 "ICMPv6 RA: adding default router.\n");
1252
1253 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1254 if (rt == NULL) {
1255 ND_PRINTK0(KERN_ERR
1256 "ICMPv6 RA: %s() failed to add default route.\n",
1257 __func__);
1258 in6_dev_put(in6_dev);
1259 return;
1260 }
1261
1262 neigh = dst_get_neighbour(&rt->dst);
1263 if (neigh == NULL) {
1264 ND_PRINTK0(KERN_ERR
1265 "ICMPv6 RA: %s() got default router without neighbour.\n",
1266 __func__);
1267 dst_release(&rt->dst);
1268 in6_dev_put(in6_dev);
1269 return;
1270 }
1271 neigh->flags |= NTF_ROUTER;
1272 } else if (rt) {
1273 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1274 }
1275
1276 if (rt)
1277 rt->rt6i_expires = jiffies + (HZ * lifetime);
1278
1279 if (ra_msg->icmph.icmp6_hop_limit) {
1280 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1281 if (rt)
1282 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1283 ra_msg->icmph.icmp6_hop_limit);
1284 }
1285
1286skip_defrtr:
1287
1288 /*
1289 * Update Reachable Time and Retrans Timer
1290 */
1291
1292 if (in6_dev->nd_parms) {
1293 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1294
1295 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1296 rtime = (rtime*HZ)/1000;
1297 if (rtime < HZ/10)
1298 rtime = HZ/10;
1299 in6_dev->nd_parms->retrans_time = rtime;
1300 in6_dev->tstamp = jiffies;
1301 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1302 }
1303
1304 rtime = ntohl(ra_msg->reachable_time);
1305 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1306 rtime = (rtime*HZ)/1000;
1307
1308 if (rtime < HZ/10)
1309 rtime = HZ/10;
1310
1311 if (rtime != in6_dev->nd_parms->base_reachable_time) {
1312 in6_dev->nd_parms->base_reachable_time = rtime;
1313 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1314 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1315 in6_dev->tstamp = jiffies;
1316 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1317 }
1318 }
1319 }
1320
1321skip_linkparms:
1322
1323 /*
1324 * Process options.
1325 */
1326
1327 if (!neigh)
1328 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1329 skb->dev, 1);
1330 if (neigh) {
1331 u8 *lladdr = NULL;
1332 if (ndopts.nd_opts_src_lladdr) {
1333 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1334 skb->dev);
1335 if (!lladdr) {
1336 ND_PRINTK2(KERN_WARNING
1337 "ICMPv6 RA: invalid link-layer address length\n");
1338 goto out;
1339 }
1340 }
1341 neigh_update(neigh, lladdr, NUD_STALE,
1342 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1343 NEIGH_UPDATE_F_OVERRIDE|
1344 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1345 NEIGH_UPDATE_F_ISROUTER);
1346 }
1347
1348 if (!accept_ra(in6_dev))
1349 goto out;
1350
1351#ifdef CONFIG_IPV6_ROUTE_INFO
1352 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1353 struct nd_opt_hdr *p;
1354 for (p = ndopts.nd_opts_ri;
1355 p;
1356 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1357 struct route_info *ri = (struct route_info *)p;
1358#ifdef CONFIG_IPV6_NDISC_NODETYPE
1359 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1360 ri->prefix_len == 0)
1361 continue;
1362#endif
1363 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1364 continue;
1365 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1366 &ipv6_hdr(skb)->saddr);
1367 }
1368 }
1369#endif
1370
1371#ifdef CONFIG_IPV6_NDISC_NODETYPE
1372 /* skip link-specific ndopts from interior routers */
1373 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1374 goto out;
1375#endif
1376
1377 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1378 struct nd_opt_hdr *p;
1379 for (p = ndopts.nd_opts_pi;
1380 p;
1381 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1382 addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1383 }
1384 }
1385
1386 if (ndopts.nd_opts_mtu) {
1387 __be32 n;
1388 u32 mtu;
1389
1390 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1391 mtu = ntohl(n);
1392
1393 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1394 ND_PRINTK2(KERN_WARNING
1395 "ICMPv6 RA: invalid mtu: %d\n",
1396 mtu);
1397 } else if (in6_dev->cnf.mtu6 != mtu) {
1398 in6_dev->cnf.mtu6 = mtu;
1399
1400 if (rt)
1401 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1402
1403 rt6_mtu_change(skb->dev, mtu);
1404 }
1405 }
1406
1407 if (ndopts.nd_useropts) {
1408 struct nd_opt_hdr *p;
1409 for (p = ndopts.nd_useropts;
1410 p;
1411 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1412 ndisc_ra_useropt(skb, p);
1413 }
1414 }
1415
1416 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1417 ND_PRINTK2(KERN_WARNING
1418 "ICMPv6 RA: invalid RA options");
1419 }
1420out:
1421 if (rt)
1422 dst_release(&rt->dst);
1423 else if (neigh)
1424 neigh_release(neigh);
1425 in6_dev_put(in6_dev);
1426}
1427
1428static void ndisc_redirect_rcv(struct sk_buff *skb)
1429{
1430 struct inet6_dev *in6_dev;
1431 struct icmp6hdr *icmph;
1432 const struct in6_addr *dest;
1433 const struct in6_addr *target; /* new first hop to destination */
1434 struct neighbour *neigh;
1435 int on_link = 0;
1436 struct ndisc_options ndopts;
1437 int optlen;
1438 u8 *lladdr = NULL;
1439
1440#ifdef CONFIG_IPV6_NDISC_NODETYPE
1441 switch (skb->ndisc_nodetype) {
1442 case NDISC_NODETYPE_HOST:
1443 case NDISC_NODETYPE_NODEFAULT:
1444 ND_PRINTK2(KERN_WARNING
1445 "ICMPv6 Redirect: from host or unauthorized router\n");
1446 return;
1447 }
1448#endif
1449
1450 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1451 ND_PRINTK2(KERN_WARNING
1452 "ICMPv6 Redirect: source address is not link-local.\n");
1453 return;
1454 }
1455
1456 optlen = skb->tail - skb->transport_header;
1457 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1458
1459 if (optlen < 0) {
1460 ND_PRINTK2(KERN_WARNING
1461 "ICMPv6 Redirect: packet too short\n");
1462 return;
1463 }
1464
1465 icmph = icmp6_hdr(skb);
1466 target = (const struct in6_addr *) (icmph + 1);
1467 dest = target + 1;
1468
1469 if (ipv6_addr_is_multicast(dest)) {
1470 ND_PRINTK2(KERN_WARNING
1471 "ICMPv6 Redirect: destination address is multicast.\n");
1472 return;
1473 }
1474
1475 if (ipv6_addr_equal(dest, target)) {
1476 on_link = 1;
1477 } else if (ipv6_addr_type(target) !=
1478 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1479 ND_PRINTK2(KERN_WARNING
1480 "ICMPv6 Redirect: target address is not link-local unicast.\n");
1481 return;
1482 }
1483
1484 in6_dev = in6_dev_get(skb->dev);
1485 if (!in6_dev)
1486 return;
1487 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1488 in6_dev_put(in6_dev);
1489 return;
1490 }
1491
1492 /* RFC2461 8.1:
1493 * The IP source address of the Redirect MUST be the same as the current
1494 * first-hop router for the specified ICMP Destination Address.
1495 */
1496
1497 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1498 ND_PRINTK2(KERN_WARNING
1499 "ICMPv6 Redirect: invalid ND options\n");
1500 in6_dev_put(in6_dev);
1501 return;
1502 }
1503 if (ndopts.nd_opts_tgt_lladdr) {
1504 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1505 skb->dev);
1506 if (!lladdr) {
1507 ND_PRINTK2(KERN_WARNING
1508 "ICMPv6 Redirect: invalid link-layer address length\n");
1509 in6_dev_put(in6_dev);
1510 return;
1511 }
1512 }
1513
1514 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1515 if (neigh) {
1516 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1517 &ipv6_hdr(skb)->saddr, neigh, lladdr,
1518 on_link);
1519 neigh_release(neigh);
1520 }
1521 in6_dev_put(in6_dev);
1522}
1523
1524void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1525 const struct in6_addr *target)
1526{
1527 struct net_device *dev = skb->dev;
1528 struct net *net = dev_net(dev);
1529 struct sock *sk = net->ipv6.ndisc_sk;
1530 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1531 struct sk_buff *buff;
1532 struct icmp6hdr *icmph;
1533 struct in6_addr saddr_buf;
1534 struct in6_addr *addrp;
1535 struct rt6_info *rt;
1536 struct dst_entry *dst;
1537 struct inet6_dev *idev;
1538 struct flowi6 fl6;
1539 u8 *opt;
1540 int rd_len;
1541 int err;
1542 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1543
1544 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1545 ND_PRINTK2(KERN_WARNING
1546 "ICMPv6 Redirect: no link-local address on %s\n",
1547 dev->name);
1548 return;
1549 }
1550
1551 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1552 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1553 ND_PRINTK2(KERN_WARNING
1554 "ICMPv6 Redirect: target address is not link-local unicast.\n");
1555 return;
1556 }
1557
1558 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1559 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1560
1561 dst = ip6_route_output(net, NULL, &fl6);
1562 if (dst == NULL)
1563 return;
1564
1565 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1566 if (IS_ERR(dst))
1567 return;
1568
1569 rt = (struct rt6_info *) dst;
1570
1571 if (rt->rt6i_flags & RTF_GATEWAY) {
1572 ND_PRINTK2(KERN_WARNING
1573 "ICMPv6 Redirect: destination is not a neighbour.\n");
1574 goto release;
1575 }
1576 if (!rt->rt6i_peer)
1577 rt6_bind_peer(rt, 1);
1578 if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
1579 goto release;
1580
1581 if (dev->addr_len) {
1582 read_lock_bh(&neigh->lock);
1583 if (neigh->nud_state & NUD_VALID) {
1584 memcpy(ha_buf, neigh->ha, dev->addr_len);
1585 read_unlock_bh(&neigh->lock);
1586 ha = ha_buf;
1587 len += ndisc_opt_addr_space(dev);
1588 } else
1589 read_unlock_bh(&neigh->lock);
1590 }
1591
1592 rd_len = min_t(unsigned int,
1593 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1594 rd_len &= ~0x7;
1595 len += rd_len;
1596
1597 buff = sock_alloc_send_skb(sk,
1598 (MAX_HEADER + sizeof(struct ipv6hdr) +
1599 len + LL_ALLOCATED_SPACE(dev)),
1600 1, &err);
1601 if (buff == NULL) {
1602 ND_PRINTK0(KERN_ERR
1603 "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1604 __func__, err);
1605 goto release;
1606 }
1607
1608 skb_reserve(buff, LL_RESERVED_SPACE(dev));
1609 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1610 IPPROTO_ICMPV6, len);
1611
1612 skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1613 skb_put(buff, len);
1614 icmph = icmp6_hdr(buff);
1615
1616 memset(icmph, 0, sizeof(struct icmp6hdr));
1617 icmph->icmp6_type = NDISC_REDIRECT;
1618
1619 /*
1620 * copy target and destination addresses
1621 */
1622
1623 addrp = (struct in6_addr *)(icmph + 1);
1624 ipv6_addr_copy(addrp, target);
1625 addrp++;
1626 ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1627
1628 opt = (u8*) (addrp + 1);
1629
1630 /*
1631 * include target_address option
1632 */
1633
1634 if (ha)
1635 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1636 dev->addr_len, dev->type);
1637
1638 /*
1639 * build redirect option and copy skb over to the new packet.
1640 */
1641
1642 memset(opt, 0, 8);
1643 *(opt++) = ND_OPT_REDIRECT_HDR;
1644 *(opt++) = (rd_len >> 3);
1645 opt += 6;
1646
1647 memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1648
1649 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1650 len, IPPROTO_ICMPV6,
1651 csum_partial(icmph, len, 0));
1652
1653 skb_dst_set(buff, dst);
1654 idev = in6_dev_get(dst->dev);
1655 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1656 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1657 dst_output);
1658 if (!err) {
1659 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1660 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1661 }
1662
1663 if (likely(idev != NULL))
1664 in6_dev_put(idev);
1665 return;
1666
1667release:
1668 dst_release(dst);
1669}
1670
1671static void pndisc_redo(struct sk_buff *skb)
1672{
1673 ndisc_recv_ns(skb);
1674 kfree_skb(skb);
1675}
1676
1677int ndisc_rcv(struct sk_buff *skb)
1678{
1679 struct nd_msg *msg;
1680
1681 if (!pskb_may_pull(skb, skb->len))
1682 return 0;
1683
1684 msg = (struct nd_msg *)skb_transport_header(skb);
1685
1686 __skb_push(skb, skb->data - skb_transport_header(skb));
1687
1688 if (ipv6_hdr(skb)->hop_limit != 255) {
1689 ND_PRINTK2(KERN_WARNING
1690 "ICMPv6 NDISC: invalid hop-limit: %d\n",
1691 ipv6_hdr(skb)->hop_limit);
1692 return 0;
1693 }
1694
1695 if (msg->icmph.icmp6_code != 0) {
1696 ND_PRINTK2(KERN_WARNING
1697 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1698 msg->icmph.icmp6_code);
1699 return 0;
1700 }
1701
1702 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1703
1704 switch (msg->icmph.icmp6_type) {
1705 case NDISC_NEIGHBOUR_SOLICITATION:
1706 ndisc_recv_ns(skb);
1707 break;
1708
1709 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1710 ndisc_recv_na(skb);
1711 break;
1712
1713 case NDISC_ROUTER_SOLICITATION:
1714 ndisc_recv_rs(skb);
1715 break;
1716
1717 case NDISC_ROUTER_ADVERTISEMENT:
1718 ndisc_router_discovery(skb);
1719 break;
1720
1721 case NDISC_REDIRECT:
1722 ndisc_redirect_rcv(skb);
1723 break;
1724 }
1725
1726 return 0;
1727}
1728
1729static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1730{
1731 struct net_device *dev = ptr;
1732 struct net *net = dev_net(dev);
1733
1734 switch (event) {
1735 case NETDEV_CHANGEADDR:
1736 neigh_changeaddr(&nd_tbl, dev);
1737 fib6_run_gc(~0UL, net);
1738 break;
1739 case NETDEV_DOWN:
1740 neigh_ifdown(&nd_tbl, dev);
1741 fib6_run_gc(~0UL, net);
1742 break;
1743 case NETDEV_NOTIFY_PEERS:
1744 ndisc_send_unsol_na(dev);
1745 break;
1746 default:
1747 break;
1748 }
1749
1750 return NOTIFY_DONE;
1751}
1752
1753static struct notifier_block ndisc_netdev_notifier = {
1754 .notifier_call = ndisc_netdev_event,
1755};
1756
1757#ifdef CONFIG_SYSCTL
1758static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1759 const char *func, const char *dev_name)
1760{
1761 static char warncomm[TASK_COMM_LEN];
1762 static int warned;
1763 if (strcmp(warncomm, current->comm) && warned < 5) {
1764 strcpy(warncomm, current->comm);
1765 printk(KERN_WARNING
1766 "process `%s' is using deprecated sysctl (%s) "
1767 "net.ipv6.neigh.%s.%s; "
1768 "Use net.ipv6.neigh.%s.%s_ms "
1769 "instead.\n",
1770 warncomm, func,
1771 dev_name, ctl->procname,
1772 dev_name, ctl->procname);
1773 warned++;
1774 }
1775}
1776
1777int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1778{
1779 struct net_device *dev = ctl->extra1;
1780 struct inet6_dev *idev;
1781 int ret;
1782
1783 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1784 (strcmp(ctl->procname, "base_reachable_time") == 0))
1785 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1786
1787 if (strcmp(ctl->procname, "retrans_time") == 0)
1788 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1789
1790 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1791 ret = proc_dointvec_jiffies(ctl, write,
1792 buffer, lenp, ppos);
1793
1794 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1795 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1796 ret = proc_dointvec_ms_jiffies(ctl, write,
1797 buffer, lenp, ppos);
1798 else
1799 ret = -1;
1800
1801 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1802 if (ctl->data == &idev->nd_parms->base_reachable_time)
1803 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1804 idev->tstamp = jiffies;
1805 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1806 in6_dev_put(idev);
1807 }
1808 return ret;
1809}
1810
1811
1812#endif
1813
1814static int __net_init ndisc_net_init(struct net *net)
1815{
1816 struct ipv6_pinfo *np;
1817 struct sock *sk;
1818 int err;
1819
1820 err = inet_ctl_sock_create(&sk, PF_INET6,
1821 SOCK_RAW, IPPROTO_ICMPV6, net);
1822 if (err < 0) {
1823 ND_PRINTK0(KERN_ERR
1824 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1825 err);
1826 return err;
1827 }
1828
1829 net->ipv6.ndisc_sk = sk;
1830
1831 np = inet6_sk(sk);
1832 np->hop_limit = 255;
1833 /* Do not loopback ndisc messages */
1834 np->mc_loop = 0;
1835
1836 return 0;
1837}
1838
1839static void __net_exit ndisc_net_exit(struct net *net)
1840{
1841 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1842}
1843
1844static struct pernet_operations ndisc_net_ops = {
1845 .init = ndisc_net_init,
1846 .exit = ndisc_net_exit,
1847};
1848
1849int __init ndisc_init(void)
1850{
1851 int err;
1852
1853 err = register_pernet_subsys(&ndisc_net_ops);
1854 if (err)
1855 return err;
1856 /*
1857 * Initialize the neighbour table
1858 */
1859 neigh_table_init(&nd_tbl);
1860
1861#ifdef CONFIG_SYSCTL
1862 err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6",
1863 &ndisc_ifinfo_sysctl_change);
1864 if (err)
1865 goto out_unregister_pernet;
1866#endif
1867 err = register_netdevice_notifier(&ndisc_netdev_notifier);
1868 if (err)
1869 goto out_unregister_sysctl;
1870out:
1871 return err;
1872
1873out_unregister_sysctl:
1874#ifdef CONFIG_SYSCTL
1875 neigh_sysctl_unregister(&nd_tbl.parms);
1876out_unregister_pernet:
1877#endif
1878 unregister_pernet_subsys(&ndisc_net_ops);
1879 goto out;
1880}
1881
1882void ndisc_cleanup(void)
1883{
1884 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1885#ifdef CONFIG_SYSCTL
1886 neigh_sysctl_unregister(&nd_tbl.parms);
1887#endif
1888 neigh_table_clear(&nd_tbl);
1889 unregister_pernet_subsys(&ndisc_net_ops);
1890}
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);
84
85static const struct neigh_ops ndisc_generic_ops = {
86 .family = AF_INET6,
87 .solicit = ndisc_solicit,
88 .error_report = ndisc_error_report,
89 .output = neigh_resolve_output,
90 .connected_output = neigh_connected_output,
91};
92
93static const struct neigh_ops ndisc_hh_ops = {
94 .family = AF_INET6,
95 .solicit = ndisc_solicit,
96 .error_report = ndisc_error_report,
97 .output = neigh_resolve_output,
98 .connected_output = neigh_resolve_output,
99};
100
101
102static const struct neigh_ops ndisc_direct_ops = {
103 .family = AF_INET6,
104 .output = neigh_direct_output,
105 .connected_output = neigh_direct_output,
106};
107
108struct neigh_table nd_tbl = {
109 .family = AF_INET6,
110 .key_len = sizeof(struct in6_addr),
111 .protocol = cpu_to_be16(ETH_P_IPV6),
112 .hash = ndisc_hash,
113 .key_eq = ndisc_key_eq,
114 .constructor = ndisc_constructor,
115 .pconstructor = pndisc_constructor,
116 .pdestructor = pndisc_destructor,
117 .proxy_redo = pndisc_redo,
118 .allow_add = ndisc_allow_add,
119 .id = "ndisc_cache",
120 .parms = {
121 .tbl = &nd_tbl,
122 .reachable_time = ND_REACHABLE_TIME,
123 .data = {
124 [NEIGH_VAR_MCAST_PROBES] = 3,
125 [NEIGH_VAR_UCAST_PROBES] = 3,
126 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
127 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
128 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
129 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
130 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
131 [NEIGH_VAR_PROXY_QLEN] = 64,
132 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
133 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
134 },
135 },
136 .gc_interval = 30 * HZ,
137 .gc_thresh1 = 128,
138 .gc_thresh2 = 512,
139 .gc_thresh3 = 1024,
140};
141EXPORT_SYMBOL_GPL(nd_tbl);
142
143void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
144 int data_len, int pad)
145{
146 int space = __ndisc_opt_addr_space(data_len, pad);
147 u8 *opt = skb_put(skb, space);
148
149 opt[0] = type;
150 opt[1] = space>>3;
151
152 memset(opt + 2, 0, pad);
153 opt += pad;
154 space -= pad;
155
156 memcpy(opt+2, data, data_len);
157 data_len += 2;
158 opt += data_len;
159 space -= data_len;
160 if (space > 0)
161 memset(opt, 0, space);
162}
163EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
164
165static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
166 void *data, u8 icmp6_type)
167{
168 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
169 ndisc_addr_option_pad(skb->dev->type));
170 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
171}
172
173static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
174 void *ha,
175 const u8 *ops_data)
176{
177 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
178 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
179}
180
181static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
182 struct nd_opt_hdr *end)
183{
184 int type;
185 if (!cur || !end || cur >= end)
186 return NULL;
187 type = cur->nd_opt_type;
188 do {
189 cur = ((void *)cur) + (cur->nd_opt_len << 3);
190 } while (cur < end && cur->nd_opt_type != type);
191 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
192}
193
194static inline int ndisc_is_useropt(const struct net_device *dev,
195 struct nd_opt_hdr *opt)
196{
197 return opt->nd_opt_type == ND_OPT_RDNSS ||
198 opt->nd_opt_type == ND_OPT_DNSSL ||
199 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
200 opt->nd_opt_type == ND_OPT_PREF64 ||
201 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
202}
203
204static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
205 struct nd_opt_hdr *cur,
206 struct nd_opt_hdr *end)
207{
208 if (!cur || !end || cur >= end)
209 return NULL;
210 do {
211 cur = ((void *)cur) + (cur->nd_opt_len << 3);
212 } while (cur < end && !ndisc_is_useropt(dev, cur));
213 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
214}
215
216struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
217 u8 *opt, int opt_len,
218 struct ndisc_options *ndopts)
219{
220 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
221
222 if (!nd_opt || opt_len < 0 || !ndopts)
223 return NULL;
224 memset(ndopts, 0, sizeof(*ndopts));
225 while (opt_len) {
226 int l;
227 if (opt_len < sizeof(struct nd_opt_hdr))
228 return NULL;
229 l = nd_opt->nd_opt_len << 3;
230 if (opt_len < l || l == 0)
231 return NULL;
232 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
233 goto next_opt;
234 switch (nd_opt->nd_opt_type) {
235 case ND_OPT_SOURCE_LL_ADDR:
236 case ND_OPT_TARGET_LL_ADDR:
237 case ND_OPT_MTU:
238 case ND_OPT_NONCE:
239 case ND_OPT_REDIRECT_HDR:
240 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
241 ND_PRINTK(2, warn,
242 "%s: duplicated ND6 option found: type=%d\n",
243 __func__, nd_opt->nd_opt_type);
244 } else {
245 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
246 }
247 break;
248 case ND_OPT_PREFIX_INFO:
249 ndopts->nd_opts_pi_end = nd_opt;
250 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
251 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
252 break;
253#ifdef CONFIG_IPV6_ROUTE_INFO
254 case ND_OPT_ROUTE_INFO:
255 ndopts->nd_opts_ri_end = nd_opt;
256 if (!ndopts->nd_opts_ri)
257 ndopts->nd_opts_ri = nd_opt;
258 break;
259#endif
260 default:
261 if (ndisc_is_useropt(dev, nd_opt)) {
262 ndopts->nd_useropts_end = nd_opt;
263 if (!ndopts->nd_useropts)
264 ndopts->nd_useropts = nd_opt;
265 } else {
266 /*
267 * Unknown options must be silently ignored,
268 * to accommodate future extension to the
269 * protocol.
270 */
271 ND_PRINTK(2, notice,
272 "%s: ignored unsupported option; type=%d, len=%d\n",
273 __func__,
274 nd_opt->nd_opt_type,
275 nd_opt->nd_opt_len);
276 }
277 }
278next_opt:
279 opt_len -= l;
280 nd_opt = ((void *)nd_opt) + l;
281 }
282 return ndopts;
283}
284
285int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
286{
287 switch (dev->type) {
288 case ARPHRD_ETHER:
289 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
290 case ARPHRD_FDDI:
291 ipv6_eth_mc_map(addr, buf);
292 return 0;
293 case ARPHRD_ARCNET:
294 ipv6_arcnet_mc_map(addr, buf);
295 return 0;
296 case ARPHRD_INFINIBAND:
297 ipv6_ib_mc_map(addr, dev->broadcast, buf);
298 return 0;
299 case ARPHRD_IPGRE:
300 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
301 default:
302 if (dir) {
303 memcpy(buf, dev->broadcast, dev->addr_len);
304 return 0;
305 }
306 }
307 return -EINVAL;
308}
309EXPORT_SYMBOL(ndisc_mc_map);
310
311static u32 ndisc_hash(const void *pkey,
312 const struct net_device *dev,
313 __u32 *hash_rnd)
314{
315 return ndisc_hashfn(pkey, dev, hash_rnd);
316}
317
318static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
319{
320 return neigh_key_eq128(n, pkey);
321}
322
323static int ndisc_constructor(struct neighbour *neigh)
324{
325 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
326 struct net_device *dev = neigh->dev;
327 struct inet6_dev *in6_dev;
328 struct neigh_parms *parms;
329 bool is_multicast = ipv6_addr_is_multicast(addr);
330
331 in6_dev = in6_dev_get(dev);
332 if (!in6_dev) {
333 return -EINVAL;
334 }
335
336 parms = in6_dev->nd_parms;
337 __neigh_parms_put(neigh->parms);
338 neigh->parms = neigh_parms_clone(parms);
339
340 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
341 if (!dev->header_ops) {
342 neigh->nud_state = NUD_NOARP;
343 neigh->ops = &ndisc_direct_ops;
344 neigh->output = neigh_direct_output;
345 } else {
346 if (is_multicast) {
347 neigh->nud_state = NUD_NOARP;
348 ndisc_mc_map(addr, neigh->ha, dev, 1);
349 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
350 neigh->nud_state = NUD_NOARP;
351 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
352 if (dev->flags&IFF_LOOPBACK)
353 neigh->type = RTN_LOCAL;
354 } else if (dev->flags&IFF_POINTOPOINT) {
355 neigh->nud_state = NUD_NOARP;
356 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
357 }
358 if (dev->header_ops->cache)
359 neigh->ops = &ndisc_hh_ops;
360 else
361 neigh->ops = &ndisc_generic_ops;
362 if (neigh->nud_state&NUD_VALID)
363 neigh->output = neigh->ops->connected_output;
364 else
365 neigh->output = neigh->ops->output;
366 }
367 in6_dev_put(in6_dev);
368 return 0;
369}
370
371static int pndisc_constructor(struct pneigh_entry *n)
372{
373 struct in6_addr *addr = (struct in6_addr *)&n->key;
374 struct in6_addr maddr;
375 struct net_device *dev = n->dev;
376
377 if (!dev || !__in6_dev_get(dev))
378 return -EINVAL;
379 addrconf_addr_solict_mult(addr, &maddr);
380 ipv6_dev_mc_inc(dev, &maddr);
381 return 0;
382}
383
384static void pndisc_destructor(struct pneigh_entry *n)
385{
386 struct in6_addr *addr = (struct in6_addr *)&n->key;
387 struct in6_addr maddr;
388 struct net_device *dev = n->dev;
389
390 if (!dev || !__in6_dev_get(dev))
391 return;
392 addrconf_addr_solict_mult(addr, &maddr);
393 ipv6_dev_mc_dec(dev, &maddr);
394}
395
396/* called with rtnl held */
397static bool ndisc_allow_add(const struct net_device *dev,
398 struct netlink_ext_ack *extack)
399{
400 struct inet6_dev *idev = __in6_dev_get(dev);
401
402 if (!idev || idev->cnf.disable_ipv6) {
403 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
404 return false;
405 }
406
407 return true;
408}
409
410static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
411 int len)
412{
413 int hlen = LL_RESERVED_SPACE(dev);
414 int tlen = dev->needed_tailroom;
415 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
416 struct sk_buff *skb;
417
418 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
419 if (!skb) {
420 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
421 __func__);
422 return NULL;
423 }
424
425 skb->protocol = htons(ETH_P_IPV6);
426 skb->dev = dev;
427
428 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
429 skb_reset_transport_header(skb);
430
431 /* Manually assign socket ownership as we avoid calling
432 * sock_alloc_send_pskb() to bypass wmem buffer limits
433 */
434 skb_set_owner_w(skb, sk);
435
436 return skb;
437}
438
439static void ip6_nd_hdr(struct sk_buff *skb,
440 const struct in6_addr *saddr,
441 const struct in6_addr *daddr,
442 int hop_limit, int len)
443{
444 struct ipv6hdr *hdr;
445 struct inet6_dev *idev;
446 unsigned tclass;
447
448 rcu_read_lock();
449 idev = __in6_dev_get(skb->dev);
450 tclass = idev ? idev->cnf.ndisc_tclass : 0;
451 rcu_read_unlock();
452
453 skb_push(skb, sizeof(*hdr));
454 skb_reset_network_header(skb);
455 hdr = ipv6_hdr(skb);
456
457 ip6_flow_hdr(hdr, tclass, 0);
458
459 hdr->payload_len = htons(len);
460 hdr->nexthdr = IPPROTO_ICMPV6;
461 hdr->hop_limit = hop_limit;
462
463 hdr->saddr = *saddr;
464 hdr->daddr = *daddr;
465}
466
467static void ndisc_send_skb(struct sk_buff *skb,
468 const struct in6_addr *daddr,
469 const struct in6_addr *saddr)
470{
471 struct dst_entry *dst = skb_dst(skb);
472 struct net *net = dev_net(skb->dev);
473 struct sock *sk = net->ipv6.ndisc_sk;
474 struct inet6_dev *idev;
475 int err;
476 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
477 u8 type;
478
479 type = icmp6h->icmp6_type;
480
481 if (!dst) {
482 struct flowi6 fl6;
483 int oif = skb->dev->ifindex;
484
485 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
486 dst = icmp6_dst_alloc(skb->dev, &fl6);
487 if (IS_ERR(dst)) {
488 kfree_skb(skb);
489 return;
490 }
491
492 skb_dst_set(skb, dst);
493 }
494
495 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
496 IPPROTO_ICMPV6,
497 csum_partial(icmp6h,
498 skb->len, 0));
499
500 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
501
502 rcu_read_lock();
503 idev = __in6_dev_get(dst->dev);
504 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
505
506 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
507 net, sk, skb, NULL, dst->dev,
508 dst_output);
509 if (!err) {
510 ICMP6MSGOUT_INC_STATS(net, idev, type);
511 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
512 }
513
514 rcu_read_unlock();
515}
516
517void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
518 const struct in6_addr *solicited_addr,
519 bool router, bool solicited, bool override, bool inc_opt)
520{
521 struct sk_buff *skb;
522 struct in6_addr tmpaddr;
523 struct inet6_ifaddr *ifp;
524 const struct in6_addr *src_addr;
525 struct nd_msg *msg;
526 int optlen = 0;
527
528 /* for anycast or proxy, solicited_addr != src_addr */
529 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
530 if (ifp) {
531 src_addr = solicited_addr;
532 if (ifp->flags & IFA_F_OPTIMISTIC)
533 override = false;
534 inc_opt |= ifp->idev->cnf.force_tllao;
535 in6_ifa_put(ifp);
536 } else {
537 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
538 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
539 &tmpaddr))
540 return;
541 src_addr = &tmpaddr;
542 }
543
544 if (!dev->addr_len)
545 inc_opt = false;
546 if (inc_opt)
547 optlen += ndisc_opt_addr_space(dev,
548 NDISC_NEIGHBOUR_ADVERTISEMENT);
549
550 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
551 if (!skb)
552 return;
553
554 msg = skb_put(skb, sizeof(*msg));
555 *msg = (struct nd_msg) {
556 .icmph = {
557 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
558 .icmp6_router = router,
559 .icmp6_solicited = solicited,
560 .icmp6_override = override,
561 },
562 .target = *solicited_addr,
563 };
564
565 if (inc_opt)
566 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
567 dev->dev_addr,
568 NDISC_NEIGHBOUR_ADVERTISEMENT);
569
570 ndisc_send_skb(skb, daddr, src_addr);
571}
572
573static void ndisc_send_unsol_na(struct net_device *dev)
574{
575 struct inet6_dev *idev;
576 struct inet6_ifaddr *ifa;
577
578 idev = in6_dev_get(dev);
579 if (!idev)
580 return;
581
582 read_lock_bh(&idev->lock);
583 list_for_each_entry(ifa, &idev->addr_list, if_list) {
584 /* skip tentative addresses until dad completes */
585 if (ifa->flags & IFA_F_TENTATIVE &&
586 !(ifa->flags & IFA_F_OPTIMISTIC))
587 continue;
588
589 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
590 /*router=*/ !!idev->cnf.forwarding,
591 /*solicited=*/ false, /*override=*/ true,
592 /*inc_opt=*/ true);
593 }
594 read_unlock_bh(&idev->lock);
595
596 in6_dev_put(idev);
597}
598
599void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
600 const struct in6_addr *daddr, const struct in6_addr *saddr,
601 u64 nonce)
602{
603 struct sk_buff *skb;
604 struct in6_addr addr_buf;
605 int inc_opt = dev->addr_len;
606 int optlen = 0;
607 struct nd_msg *msg;
608
609 if (!saddr) {
610 if (ipv6_get_lladdr(dev, &addr_buf,
611 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
612 return;
613 saddr = &addr_buf;
614 }
615
616 if (ipv6_addr_any(saddr))
617 inc_opt = false;
618 if (inc_opt)
619 optlen += ndisc_opt_addr_space(dev,
620 NDISC_NEIGHBOUR_SOLICITATION);
621 if (nonce != 0)
622 optlen += 8;
623
624 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
625 if (!skb)
626 return;
627
628 msg = skb_put(skb, sizeof(*msg));
629 *msg = (struct nd_msg) {
630 .icmph = {
631 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
632 },
633 .target = *solicit,
634 };
635
636 if (inc_opt)
637 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
638 dev->dev_addr,
639 NDISC_NEIGHBOUR_SOLICITATION);
640 if (nonce != 0) {
641 u8 *opt = skb_put(skb, 8);
642
643 opt[0] = ND_OPT_NONCE;
644 opt[1] = 8 >> 3;
645 memcpy(opt + 2, &nonce, 6);
646 }
647
648 ndisc_send_skb(skb, daddr, saddr);
649}
650
651void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
652 const struct in6_addr *daddr)
653{
654 struct sk_buff *skb;
655 struct rs_msg *msg;
656 int send_sllao = dev->addr_len;
657 int optlen = 0;
658
659#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
660 /*
661 * According to section 2.2 of RFC 4429, we must not
662 * send router solicitations with a sllao from
663 * optimistic addresses, but we may send the solicitation
664 * if we don't include the sllao. So here we check
665 * if our address is optimistic, and if so, we
666 * suppress the inclusion of the sllao.
667 */
668 if (send_sllao) {
669 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
670 dev, 1);
671 if (ifp) {
672 if (ifp->flags & IFA_F_OPTIMISTIC) {
673 send_sllao = 0;
674 }
675 in6_ifa_put(ifp);
676 } else {
677 send_sllao = 0;
678 }
679 }
680#endif
681 if (send_sllao)
682 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
683
684 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
685 if (!skb)
686 return;
687
688 msg = skb_put(skb, sizeof(*msg));
689 *msg = (struct rs_msg) {
690 .icmph = {
691 .icmp6_type = NDISC_ROUTER_SOLICITATION,
692 },
693 };
694
695 if (send_sllao)
696 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
697 dev->dev_addr,
698 NDISC_ROUTER_SOLICITATION);
699
700 ndisc_send_skb(skb, daddr, saddr);
701}
702
703
704static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
705{
706 /*
707 * "The sender MUST return an ICMP
708 * destination unreachable"
709 */
710 dst_link_failure(skb);
711 kfree_skb(skb);
712}
713
714/* Called with locked neigh: either read or both */
715
716static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
717{
718 struct in6_addr *saddr = NULL;
719 struct in6_addr mcaddr;
720 struct net_device *dev = neigh->dev;
721 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
722 int probes = atomic_read(&neigh->probes);
723
724 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
725 dev, false, 1,
726 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
727 saddr = &ipv6_hdr(skb)->saddr;
728 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
729 if (probes < 0) {
730 if (!(neigh->nud_state & NUD_VALID)) {
731 ND_PRINTK(1, dbg,
732 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
733 __func__, target);
734 }
735 ndisc_send_ns(dev, target, target, saddr, 0);
736 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
737 neigh_app_ns(neigh);
738 } else {
739 addrconf_addr_solict_mult(target, &mcaddr);
740 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
741 }
742}
743
744static int pndisc_is_router(const void *pkey,
745 struct net_device *dev)
746{
747 struct pneigh_entry *n;
748 int ret = -1;
749
750 read_lock_bh(&nd_tbl.lock);
751 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
752 if (n)
753 ret = !!(n->flags & NTF_ROUTER);
754 read_unlock_bh(&nd_tbl.lock);
755
756 return ret;
757}
758
759void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
760 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
761 struct ndisc_options *ndopts)
762{
763 neigh_update(neigh, lladdr, new, flags, 0);
764 /* report ndisc ops about neighbour update */
765 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
766}
767
768static void ndisc_recv_ns(struct sk_buff *skb)
769{
770 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
771 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
772 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
773 u8 *lladdr = NULL;
774 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
775 offsetof(struct nd_msg, opt));
776 struct ndisc_options ndopts;
777 struct net_device *dev = skb->dev;
778 struct inet6_ifaddr *ifp;
779 struct inet6_dev *idev = NULL;
780 struct neighbour *neigh;
781 int dad = ipv6_addr_any(saddr);
782 bool inc;
783 int is_router = -1;
784 u64 nonce = 0;
785
786 if (skb->len < sizeof(struct nd_msg)) {
787 ND_PRINTK(2, warn, "NS: packet too short\n");
788 return;
789 }
790
791 if (ipv6_addr_is_multicast(&msg->target)) {
792 ND_PRINTK(2, warn, "NS: multicast target address\n");
793 return;
794 }
795
796 /*
797 * RFC2461 7.1.1:
798 * DAD has to be destined for solicited node multicast address.
799 */
800 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
801 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
802 return;
803 }
804
805 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
806 ND_PRINTK(2, warn, "NS: invalid ND options\n");
807 return;
808 }
809
810 if (ndopts.nd_opts_src_lladdr) {
811 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
812 if (!lladdr) {
813 ND_PRINTK(2, warn,
814 "NS: invalid link-layer address length\n");
815 return;
816 }
817
818 /* RFC2461 7.1.1:
819 * If the IP source address is the unspecified address,
820 * there MUST NOT be source link-layer address option
821 * in the message.
822 */
823 if (dad) {
824 ND_PRINTK(2, warn,
825 "NS: bad DAD packet (link-layer address option)\n");
826 return;
827 }
828 }
829 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
830 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
831
832 inc = ipv6_addr_is_multicast(daddr);
833
834 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
835 if (ifp) {
836have_ifp:
837 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
838 if (dad) {
839 if (nonce != 0 && ifp->dad_nonce == nonce) {
840 u8 *np = (u8 *)&nonce;
841 /* Matching nonce if looped back */
842 ND_PRINTK(2, notice,
843 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
844 ifp->idev->dev->name,
845 &ifp->addr, np);
846 goto out;
847 }
848 /*
849 * We are colliding with another node
850 * who is doing DAD
851 * so fail our DAD process
852 */
853 addrconf_dad_failure(skb, ifp);
854 return;
855 } else {
856 /*
857 * This is not a dad solicitation.
858 * If we are an optimistic node,
859 * we should respond.
860 * Otherwise, we should ignore it.
861 */
862 if (!(ifp->flags & IFA_F_OPTIMISTIC))
863 goto out;
864 }
865 }
866
867 idev = ifp->idev;
868 } else {
869 struct net *net = dev_net(dev);
870
871 /* perhaps an address on the master device */
872 if (netif_is_l3_slave(dev)) {
873 struct net_device *mdev;
874
875 mdev = netdev_master_upper_dev_get_rcu(dev);
876 if (mdev) {
877 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
878 if (ifp)
879 goto have_ifp;
880 }
881 }
882
883 idev = in6_dev_get(dev);
884 if (!idev) {
885 /* XXX: count this drop? */
886 return;
887 }
888
889 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
890 (idev->cnf.forwarding &&
891 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
892 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
893 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
894 skb->pkt_type != PACKET_HOST &&
895 inc &&
896 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
897 /*
898 * for anycast or proxy,
899 * sender should delay its response
900 * by a random time between 0 and
901 * MAX_ANYCAST_DELAY_TIME seconds.
902 * (RFC2461) -- yoshfuji
903 */
904 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
905 if (n)
906 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
907 goto out;
908 }
909 } else
910 goto out;
911 }
912
913 if (is_router < 0)
914 is_router = idev->cnf.forwarding;
915
916 if (dad) {
917 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
918 !!is_router, false, (ifp != NULL), true);
919 goto out;
920 }
921
922 if (inc)
923 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
924 else
925 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
926
927 /*
928 * update / create cache entry
929 * for the source address
930 */
931 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
932 !inc || lladdr || !dev->addr_len);
933 if (neigh)
934 ndisc_update(dev, neigh, lladdr, NUD_STALE,
935 NEIGH_UPDATE_F_WEAK_OVERRIDE|
936 NEIGH_UPDATE_F_OVERRIDE,
937 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
938 if (neigh || !dev->header_ops) {
939 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
940 true, (ifp != NULL && inc), inc);
941 if (neigh)
942 neigh_release(neigh);
943 }
944
945out:
946 if (ifp)
947 in6_ifa_put(ifp);
948 else
949 in6_dev_put(idev);
950}
951
952static void ndisc_recv_na(struct sk_buff *skb)
953{
954 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
955 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
956 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
957 u8 *lladdr = NULL;
958 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
959 offsetof(struct nd_msg, opt));
960 struct ndisc_options ndopts;
961 struct net_device *dev = skb->dev;
962 struct inet6_dev *idev = __in6_dev_get(dev);
963 struct inet6_ifaddr *ifp;
964 struct neighbour *neigh;
965
966 if (skb->len < sizeof(struct nd_msg)) {
967 ND_PRINTK(2, warn, "NA: packet too short\n");
968 return;
969 }
970
971 if (ipv6_addr_is_multicast(&msg->target)) {
972 ND_PRINTK(2, warn, "NA: target address is multicast\n");
973 return;
974 }
975
976 if (ipv6_addr_is_multicast(daddr) &&
977 msg->icmph.icmp6_solicited) {
978 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
979 return;
980 }
981
982 /* For some 802.11 wireless deployments (and possibly other networks),
983 * there will be a NA proxy and unsolicitd packets are attacks
984 * and thus should not be accepted.
985 */
986 if (!msg->icmph.icmp6_solicited && idev &&
987 idev->cnf.drop_unsolicited_na)
988 return;
989
990 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
991 ND_PRINTK(2, warn, "NS: invalid ND option\n");
992 return;
993 }
994 if (ndopts.nd_opts_tgt_lladdr) {
995 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
996 if (!lladdr) {
997 ND_PRINTK(2, warn,
998 "NA: invalid link-layer address length\n");
999 return;
1000 }
1001 }
1002 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1003 if (ifp) {
1004 if (skb->pkt_type != PACKET_LOOPBACK
1005 && (ifp->flags & IFA_F_TENTATIVE)) {
1006 addrconf_dad_failure(skb, ifp);
1007 return;
1008 }
1009 /* What should we make now? The advertisement
1010 is invalid, but ndisc specs say nothing
1011 about it. It could be misconfiguration, or
1012 an smart proxy agent tries to help us :-)
1013
1014 We should not print the error if NA has been
1015 received from loopback - it is just our own
1016 unsolicited advertisement.
1017 */
1018 if (skb->pkt_type != PACKET_LOOPBACK)
1019 ND_PRINTK(1, warn,
1020 "NA: %pM advertised our address %pI6c on %s!\n",
1021 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1022 in6_ifa_put(ifp);
1023 return;
1024 }
1025 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1026
1027 if (neigh) {
1028 u8 old_flags = neigh->flags;
1029 struct net *net = dev_net(dev);
1030
1031 if (neigh->nud_state & NUD_FAILED)
1032 goto out;
1033
1034 /*
1035 * Don't update the neighbor cache entry on a proxy NA from
1036 * ourselves because either the proxied node is off link or it
1037 * has already sent a NA to us.
1038 */
1039 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1040 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1041 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1042 /* XXX: idev->cnf.proxy_ndp */
1043 goto out;
1044 }
1045
1046 ndisc_update(dev, neigh, lladdr,
1047 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1048 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1049 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1050 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1051 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1052 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1053
1054 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1055 /*
1056 * Change: router to host
1057 */
1058 rt6_clean_tohost(dev_net(dev), saddr);
1059 }
1060
1061out:
1062 neigh_release(neigh);
1063 }
1064}
1065
1066static void ndisc_recv_rs(struct sk_buff *skb)
1067{
1068 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1069 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1070 struct neighbour *neigh;
1071 struct inet6_dev *idev;
1072 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1073 struct ndisc_options ndopts;
1074 u8 *lladdr = NULL;
1075
1076 if (skb->len < sizeof(*rs_msg))
1077 return;
1078
1079 idev = __in6_dev_get(skb->dev);
1080 if (!idev) {
1081 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1082 return;
1083 }
1084
1085 /* Don't accept RS if we're not in router mode */
1086 if (!idev->cnf.forwarding)
1087 goto out;
1088
1089 /*
1090 * Don't update NCE if src = ::;
1091 * this implies that the source node has no ip address assigned yet.
1092 */
1093 if (ipv6_addr_any(saddr))
1094 goto out;
1095
1096 /* Parse ND options */
1097 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1098 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1099 goto out;
1100 }
1101
1102 if (ndopts.nd_opts_src_lladdr) {
1103 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1104 skb->dev);
1105 if (!lladdr)
1106 goto out;
1107 }
1108
1109 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1110 if (neigh) {
1111 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1112 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1113 NEIGH_UPDATE_F_OVERRIDE|
1114 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1115 NDISC_ROUTER_SOLICITATION, &ndopts);
1116 neigh_release(neigh);
1117 }
1118out:
1119 return;
1120}
1121
1122static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1123{
1124 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1125 struct sk_buff *skb;
1126 struct nlmsghdr *nlh;
1127 struct nduseroptmsg *ndmsg;
1128 struct net *net = dev_net(ra->dev);
1129 int err;
1130 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1131 + (opt->nd_opt_len << 3));
1132 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1133
1134 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1135 if (!skb) {
1136 err = -ENOBUFS;
1137 goto errout;
1138 }
1139
1140 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1141 if (!nlh) {
1142 goto nla_put_failure;
1143 }
1144
1145 ndmsg = nlmsg_data(nlh);
1146 ndmsg->nduseropt_family = AF_INET6;
1147 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1148 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1149 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1150 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1151
1152 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1153
1154 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1155 goto nla_put_failure;
1156 nlmsg_end(skb, nlh);
1157
1158 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1159 return;
1160
1161nla_put_failure:
1162 nlmsg_free(skb);
1163 err = -EMSGSIZE;
1164errout:
1165 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1166}
1167
1168static void ndisc_router_discovery(struct sk_buff *skb)
1169{
1170 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1171 struct neighbour *neigh = NULL;
1172 struct inet6_dev *in6_dev;
1173 struct fib6_info *rt = NULL;
1174 struct net *net;
1175 int lifetime;
1176 struct ndisc_options ndopts;
1177 int optlen;
1178 unsigned int pref = 0;
1179 __u32 old_if_flags;
1180 bool send_ifinfo_notify = false;
1181
1182 __u8 *opt = (__u8 *)(ra_msg + 1);
1183
1184 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1185 sizeof(struct ra_msg);
1186
1187 ND_PRINTK(2, info,
1188 "RA: %s, dev: %s\n",
1189 __func__, skb->dev->name);
1190 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1191 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1192 return;
1193 }
1194 if (optlen < 0) {
1195 ND_PRINTK(2, warn, "RA: packet too short\n");
1196 return;
1197 }
1198
1199#ifdef CONFIG_IPV6_NDISC_NODETYPE
1200 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1201 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1202 return;
1203 }
1204#endif
1205
1206 /*
1207 * set the RA_RECV flag in the interface
1208 */
1209
1210 in6_dev = __in6_dev_get(skb->dev);
1211 if (!in6_dev) {
1212 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1213 skb->dev->name);
1214 return;
1215 }
1216
1217 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1218 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1219 return;
1220 }
1221
1222 if (!ipv6_accept_ra(in6_dev)) {
1223 ND_PRINTK(2, info,
1224 "RA: %s, did not accept ra for dev: %s\n",
1225 __func__, skb->dev->name);
1226 goto skip_linkparms;
1227 }
1228
1229#ifdef CONFIG_IPV6_NDISC_NODETYPE
1230 /* skip link-specific parameters from interior routers */
1231 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1232 ND_PRINTK(2, info,
1233 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1234 __func__, skb->dev->name);
1235 goto skip_linkparms;
1236 }
1237#endif
1238
1239 if (in6_dev->if_flags & IF_RS_SENT) {
1240 /*
1241 * flag that an RA was received after an RS was sent
1242 * out on this interface.
1243 */
1244 in6_dev->if_flags |= IF_RA_RCVD;
1245 }
1246
1247 /*
1248 * Remember the managed/otherconf flags from most recently
1249 * received RA message (RFC 2462) -- yoshfuji
1250 */
1251 old_if_flags = in6_dev->if_flags;
1252 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1253 IF_RA_OTHERCONF)) |
1254 (ra_msg->icmph.icmp6_addrconf_managed ?
1255 IF_RA_MANAGED : 0) |
1256 (ra_msg->icmph.icmp6_addrconf_other ?
1257 IF_RA_OTHERCONF : 0);
1258
1259 if (old_if_flags != in6_dev->if_flags)
1260 send_ifinfo_notify = true;
1261
1262 if (!in6_dev->cnf.accept_ra_defrtr) {
1263 ND_PRINTK(2, info,
1264 "RA: %s, defrtr is false for dev: %s\n",
1265 __func__, skb->dev->name);
1266 goto skip_defrtr;
1267 }
1268
1269 /* Do not accept RA with source-addr found on local machine unless
1270 * accept_ra_from_local is set to true.
1271 */
1272 net = dev_net(in6_dev->dev);
1273 if (!in6_dev->cnf.accept_ra_from_local &&
1274 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1275 ND_PRINTK(2, info,
1276 "RA from local address detected on dev: %s: default router ignored\n",
1277 skb->dev->name);
1278 goto skip_defrtr;
1279 }
1280
1281 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1282
1283#ifdef CONFIG_IPV6_ROUTER_PREF
1284 pref = ra_msg->icmph.icmp6_router_pref;
1285 /* 10b is handled as if it were 00b (medium) */
1286 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1287 !in6_dev->cnf.accept_ra_rtr_pref)
1288 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1289#endif
1290 /* routes added from RAs do not use nexthop objects */
1291 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1292 if (rt) {
1293 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1294 rt->fib6_nh->fib_nh_dev, NULL,
1295 &ipv6_hdr(skb)->saddr);
1296 if (!neigh) {
1297 ND_PRINTK(0, err,
1298 "RA: %s got default router without neighbour\n",
1299 __func__);
1300 fib6_info_release(rt);
1301 return;
1302 }
1303 }
1304 if (rt && lifetime == 0) {
1305 ip6_del_rt(net, rt, false);
1306 rt = NULL;
1307 }
1308
1309 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1310 rt, lifetime, skb->dev->name);
1311 if (!rt && lifetime) {
1312 ND_PRINTK(3, info, "RA: adding default router\n");
1313
1314 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1315 skb->dev, pref);
1316 if (!rt) {
1317 ND_PRINTK(0, err,
1318 "RA: %s failed to add default route\n",
1319 __func__);
1320 return;
1321 }
1322
1323 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1324 rt->fib6_nh->fib_nh_dev, NULL,
1325 &ipv6_hdr(skb)->saddr);
1326 if (!neigh) {
1327 ND_PRINTK(0, err,
1328 "RA: %s got default router without neighbour\n",
1329 __func__);
1330 fib6_info_release(rt);
1331 return;
1332 }
1333 neigh->flags |= NTF_ROUTER;
1334 } else if (rt) {
1335 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1336 }
1337
1338 if (rt)
1339 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1340 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1341 ra_msg->icmph.icmp6_hop_limit) {
1342 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1343 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1344 fib6_metric_set(rt, RTAX_HOPLIMIT,
1345 ra_msg->icmph.icmp6_hop_limit);
1346 } else {
1347 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1348 }
1349 }
1350
1351skip_defrtr:
1352
1353 /*
1354 * Update Reachable Time and Retrans Timer
1355 */
1356
1357 if (in6_dev->nd_parms) {
1358 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1359
1360 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1361 rtime = (rtime*HZ)/1000;
1362 if (rtime < HZ/100)
1363 rtime = HZ/100;
1364 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1365 in6_dev->tstamp = jiffies;
1366 send_ifinfo_notify = true;
1367 }
1368
1369 rtime = ntohl(ra_msg->reachable_time);
1370 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1371 rtime = (rtime*HZ)/1000;
1372
1373 if (rtime < HZ/10)
1374 rtime = HZ/10;
1375
1376 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1377 NEIGH_VAR_SET(in6_dev->nd_parms,
1378 BASE_REACHABLE_TIME, rtime);
1379 NEIGH_VAR_SET(in6_dev->nd_parms,
1380 GC_STALETIME, 3 * rtime);
1381 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1382 in6_dev->tstamp = jiffies;
1383 send_ifinfo_notify = true;
1384 }
1385 }
1386 }
1387
1388 /*
1389 * Send a notify if RA changed managed/otherconf flags or timer settings
1390 */
1391 if (send_ifinfo_notify)
1392 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1393
1394skip_linkparms:
1395
1396 /*
1397 * Process options.
1398 */
1399
1400 if (!neigh)
1401 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1402 skb->dev, 1);
1403 if (neigh) {
1404 u8 *lladdr = NULL;
1405 if (ndopts.nd_opts_src_lladdr) {
1406 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1407 skb->dev);
1408 if (!lladdr) {
1409 ND_PRINTK(2, warn,
1410 "RA: invalid link-layer address length\n");
1411 goto out;
1412 }
1413 }
1414 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1415 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1416 NEIGH_UPDATE_F_OVERRIDE|
1417 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1418 NEIGH_UPDATE_F_ISROUTER,
1419 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1420 }
1421
1422 if (!ipv6_accept_ra(in6_dev)) {
1423 ND_PRINTK(2, info,
1424 "RA: %s, accept_ra is false for dev: %s\n",
1425 __func__, skb->dev->name);
1426 goto out;
1427 }
1428
1429#ifdef CONFIG_IPV6_ROUTE_INFO
1430 if (!in6_dev->cnf.accept_ra_from_local &&
1431 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1432 in6_dev->dev, 0)) {
1433 ND_PRINTK(2, info,
1434 "RA from local address detected on dev: %s: router info ignored.\n",
1435 skb->dev->name);
1436 goto skip_routeinfo;
1437 }
1438
1439 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1440 struct nd_opt_hdr *p;
1441 for (p = ndopts.nd_opts_ri;
1442 p;
1443 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1444 struct route_info *ri = (struct route_info *)p;
1445#ifdef CONFIG_IPV6_NDISC_NODETYPE
1446 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1447 ri->prefix_len == 0)
1448 continue;
1449#endif
1450 if (ri->prefix_len == 0 &&
1451 !in6_dev->cnf.accept_ra_defrtr)
1452 continue;
1453 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1454 continue;
1455 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1456 continue;
1457 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1458 &ipv6_hdr(skb)->saddr);
1459 }
1460 }
1461
1462skip_routeinfo:
1463#endif
1464
1465#ifdef CONFIG_IPV6_NDISC_NODETYPE
1466 /* skip link-specific ndopts from interior routers */
1467 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1468 ND_PRINTK(2, info,
1469 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1470 __func__, skb->dev->name);
1471 goto out;
1472 }
1473#endif
1474
1475 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1476 struct nd_opt_hdr *p;
1477 for (p = ndopts.nd_opts_pi;
1478 p;
1479 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1480 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1481 (p->nd_opt_len) << 3,
1482 ndopts.nd_opts_src_lladdr != NULL);
1483 }
1484 }
1485
1486 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1487 __be32 n;
1488 u32 mtu;
1489
1490 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1491 mtu = ntohl(n);
1492
1493 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1494 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1495 } else if (in6_dev->cnf.mtu6 != mtu) {
1496 in6_dev->cnf.mtu6 = mtu;
1497 fib6_metric_set(rt, RTAX_MTU, mtu);
1498 rt6_mtu_change(skb->dev, mtu);
1499 }
1500 }
1501
1502 if (ndopts.nd_useropts) {
1503 struct nd_opt_hdr *p;
1504 for (p = ndopts.nd_useropts;
1505 p;
1506 p = ndisc_next_useropt(skb->dev, p,
1507 ndopts.nd_useropts_end)) {
1508 ndisc_ra_useropt(skb, p);
1509 }
1510 }
1511
1512 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1513 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1514 }
1515out:
1516 fib6_info_release(rt);
1517 if (neigh)
1518 neigh_release(neigh);
1519}
1520
1521static void ndisc_redirect_rcv(struct sk_buff *skb)
1522{
1523 u8 *hdr;
1524 struct ndisc_options ndopts;
1525 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1526 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1527 offsetof(struct rd_msg, opt));
1528
1529#ifdef CONFIG_IPV6_NDISC_NODETYPE
1530 switch (skb->ndisc_nodetype) {
1531 case NDISC_NODETYPE_HOST:
1532 case NDISC_NODETYPE_NODEFAULT:
1533 ND_PRINTK(2, warn,
1534 "Redirect: from host or unauthorized router\n");
1535 return;
1536 }
1537#endif
1538
1539 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1540 ND_PRINTK(2, warn,
1541 "Redirect: source address is not link-local\n");
1542 return;
1543 }
1544
1545 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1546 return;
1547
1548 if (!ndopts.nd_opts_rh) {
1549 ip6_redirect_no_header(skb, dev_net(skb->dev),
1550 skb->dev->ifindex);
1551 return;
1552 }
1553
1554 hdr = (u8 *)ndopts.nd_opts_rh;
1555 hdr += 8;
1556 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1557 return;
1558
1559 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1560}
1561
1562static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1563 struct sk_buff *orig_skb,
1564 int rd_len)
1565{
1566 u8 *opt = skb_put(skb, rd_len);
1567
1568 memset(opt, 0, 8);
1569 *(opt++) = ND_OPT_REDIRECT_HDR;
1570 *(opt++) = (rd_len >> 3);
1571 opt += 6;
1572
1573 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1574 rd_len - 8);
1575}
1576
1577void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1578{
1579 struct net_device *dev = skb->dev;
1580 struct net *net = dev_net(dev);
1581 struct sock *sk = net->ipv6.ndisc_sk;
1582 int optlen = 0;
1583 struct inet_peer *peer;
1584 struct sk_buff *buff;
1585 struct rd_msg *msg;
1586 struct in6_addr saddr_buf;
1587 struct rt6_info *rt;
1588 struct dst_entry *dst;
1589 struct flowi6 fl6;
1590 int rd_len;
1591 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1592 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1593 bool ret;
1594
1595 if (netif_is_l3_master(skb->dev)) {
1596 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1597 if (!dev)
1598 return;
1599 }
1600
1601 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1602 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1603 dev->name);
1604 return;
1605 }
1606
1607 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1608 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1609 ND_PRINTK(2, warn,
1610 "Redirect: target address is not link-local unicast\n");
1611 return;
1612 }
1613
1614 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1615 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1616
1617 dst = ip6_route_output(net, NULL, &fl6);
1618 if (dst->error) {
1619 dst_release(dst);
1620 return;
1621 }
1622 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1623 if (IS_ERR(dst))
1624 return;
1625
1626 rt = (struct rt6_info *) dst;
1627
1628 if (rt->rt6i_flags & RTF_GATEWAY) {
1629 ND_PRINTK(2, warn,
1630 "Redirect: destination is not a neighbour\n");
1631 goto release;
1632 }
1633 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1634 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1635 if (peer)
1636 inet_putpeer(peer);
1637 if (!ret)
1638 goto release;
1639
1640 if (dev->addr_len) {
1641 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1642 if (!neigh) {
1643 ND_PRINTK(2, warn,
1644 "Redirect: no neigh for target address\n");
1645 goto release;
1646 }
1647
1648 read_lock_bh(&neigh->lock);
1649 if (neigh->nud_state & NUD_VALID) {
1650 memcpy(ha_buf, neigh->ha, dev->addr_len);
1651 read_unlock_bh(&neigh->lock);
1652 ha = ha_buf;
1653 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1654 ops_data_buf,
1655 &ops_data);
1656 } else
1657 read_unlock_bh(&neigh->lock);
1658
1659 neigh_release(neigh);
1660 }
1661
1662 rd_len = min_t(unsigned int,
1663 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1664 skb->len + 8);
1665 rd_len &= ~0x7;
1666 optlen += rd_len;
1667
1668 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1669 if (!buff)
1670 goto release;
1671
1672 msg = skb_put(buff, sizeof(*msg));
1673 *msg = (struct rd_msg) {
1674 .icmph = {
1675 .icmp6_type = NDISC_REDIRECT,
1676 },
1677 .target = *target,
1678 .dest = ipv6_hdr(skb)->daddr,
1679 };
1680
1681 /*
1682 * include target_address option
1683 */
1684
1685 if (ha)
1686 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1687
1688 /*
1689 * build redirect option and copy skb over to the new packet.
1690 */
1691
1692 if (rd_len)
1693 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1694
1695 skb_dst_set(buff, dst);
1696 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1697 return;
1698
1699release:
1700 dst_release(dst);
1701}
1702
1703static void pndisc_redo(struct sk_buff *skb)
1704{
1705 ndisc_recv_ns(skb);
1706 kfree_skb(skb);
1707}
1708
1709static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1710{
1711 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1712
1713 if (!idev)
1714 return true;
1715 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1716 idev->cnf.suppress_frag_ndisc) {
1717 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1718 return true;
1719 }
1720 return false;
1721}
1722
1723int ndisc_rcv(struct sk_buff *skb)
1724{
1725 struct nd_msg *msg;
1726
1727 if (ndisc_suppress_frag_ndisc(skb))
1728 return 0;
1729
1730 if (skb_linearize(skb))
1731 return 0;
1732
1733 msg = (struct nd_msg *)skb_transport_header(skb);
1734
1735 __skb_push(skb, skb->data - skb_transport_header(skb));
1736
1737 if (ipv6_hdr(skb)->hop_limit != 255) {
1738 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1739 ipv6_hdr(skb)->hop_limit);
1740 return 0;
1741 }
1742
1743 if (msg->icmph.icmp6_code != 0) {
1744 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1745 msg->icmph.icmp6_code);
1746 return 0;
1747 }
1748
1749 switch (msg->icmph.icmp6_type) {
1750 case NDISC_NEIGHBOUR_SOLICITATION:
1751 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1752 ndisc_recv_ns(skb);
1753 break;
1754
1755 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1756 ndisc_recv_na(skb);
1757 break;
1758
1759 case NDISC_ROUTER_SOLICITATION:
1760 ndisc_recv_rs(skb);
1761 break;
1762
1763 case NDISC_ROUTER_ADVERTISEMENT:
1764 ndisc_router_discovery(skb);
1765 break;
1766
1767 case NDISC_REDIRECT:
1768 ndisc_redirect_rcv(skb);
1769 break;
1770 }
1771
1772 return 0;
1773}
1774
1775static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1776{
1777 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1778 struct netdev_notifier_change_info *change_info;
1779 struct net *net = dev_net(dev);
1780 struct inet6_dev *idev;
1781
1782 switch (event) {
1783 case NETDEV_CHANGEADDR:
1784 neigh_changeaddr(&nd_tbl, dev);
1785 fib6_run_gc(0, net, false);
1786 fallthrough;
1787 case NETDEV_UP:
1788 idev = in6_dev_get(dev);
1789 if (!idev)
1790 break;
1791 if (idev->cnf.ndisc_notify ||
1792 net->ipv6.devconf_all->ndisc_notify)
1793 ndisc_send_unsol_na(dev);
1794 in6_dev_put(idev);
1795 break;
1796 case NETDEV_CHANGE:
1797 change_info = ptr;
1798 if (change_info->flags_changed & IFF_NOARP)
1799 neigh_changeaddr(&nd_tbl, dev);
1800 if (!netif_carrier_ok(dev))
1801 neigh_carrier_down(&nd_tbl, dev);
1802 break;
1803 case NETDEV_DOWN:
1804 neigh_ifdown(&nd_tbl, dev);
1805 fib6_run_gc(0, net, false);
1806 break;
1807 case NETDEV_NOTIFY_PEERS:
1808 ndisc_send_unsol_na(dev);
1809 break;
1810 default:
1811 break;
1812 }
1813
1814 return NOTIFY_DONE;
1815}
1816
1817static struct notifier_block ndisc_netdev_notifier = {
1818 .notifier_call = ndisc_netdev_event,
1819 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1820};
1821
1822#ifdef CONFIG_SYSCTL
1823static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1824 const char *func, const char *dev_name)
1825{
1826 static char warncomm[TASK_COMM_LEN];
1827 static int warned;
1828 if (strcmp(warncomm, current->comm) && warned < 5) {
1829 strcpy(warncomm, current->comm);
1830 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1831 warncomm, func,
1832 dev_name, ctl->procname,
1833 dev_name, ctl->procname);
1834 warned++;
1835 }
1836}
1837
1838int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1839 size_t *lenp, loff_t *ppos)
1840{
1841 struct net_device *dev = ctl->extra1;
1842 struct inet6_dev *idev;
1843 int ret;
1844
1845 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1846 (strcmp(ctl->procname, "base_reachable_time") == 0))
1847 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1848
1849 if (strcmp(ctl->procname, "retrans_time") == 0)
1850 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1851
1852 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1853 ret = neigh_proc_dointvec_jiffies(ctl, write,
1854 buffer, lenp, ppos);
1855
1856 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1857 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1858 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1859 buffer, lenp, ppos);
1860 else
1861 ret = -1;
1862
1863 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1864 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1865 idev->nd_parms->reachable_time =
1866 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1867 idev->tstamp = jiffies;
1868 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1869 in6_dev_put(idev);
1870 }
1871 return ret;
1872}
1873
1874
1875#endif
1876
1877static int __net_init ndisc_net_init(struct net *net)
1878{
1879 struct ipv6_pinfo *np;
1880 struct sock *sk;
1881 int err;
1882
1883 err = inet_ctl_sock_create(&sk, PF_INET6,
1884 SOCK_RAW, IPPROTO_ICMPV6, net);
1885 if (err < 0) {
1886 ND_PRINTK(0, err,
1887 "NDISC: Failed to initialize the control socket (err %d)\n",
1888 err);
1889 return err;
1890 }
1891
1892 net->ipv6.ndisc_sk = sk;
1893
1894 np = inet6_sk(sk);
1895 np->hop_limit = 255;
1896 /* Do not loopback ndisc messages */
1897 np->mc_loop = 0;
1898
1899 return 0;
1900}
1901
1902static void __net_exit ndisc_net_exit(struct net *net)
1903{
1904 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1905}
1906
1907static struct pernet_operations ndisc_net_ops = {
1908 .init = ndisc_net_init,
1909 .exit = ndisc_net_exit,
1910};
1911
1912int __init ndisc_init(void)
1913{
1914 int err;
1915
1916 err = register_pernet_subsys(&ndisc_net_ops);
1917 if (err)
1918 return err;
1919 /*
1920 * Initialize the neighbour table
1921 */
1922 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1923
1924#ifdef CONFIG_SYSCTL
1925 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1926 ndisc_ifinfo_sysctl_change);
1927 if (err)
1928 goto out_unregister_pernet;
1929out:
1930#endif
1931 return err;
1932
1933#ifdef CONFIG_SYSCTL
1934out_unregister_pernet:
1935 unregister_pernet_subsys(&ndisc_net_ops);
1936 goto out;
1937#endif
1938}
1939
1940int __init ndisc_late_init(void)
1941{
1942 return register_netdevice_notifier(&ndisc_netdev_notifier);
1943}
1944
1945void ndisc_late_cleanup(void)
1946{
1947 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1948}
1949
1950void ndisc_cleanup(void)
1951{
1952#ifdef CONFIG_SYSCTL
1953 neigh_sysctl_unregister(&nd_tbl.parms);
1954#endif
1955 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1956 unregister_pernet_subsys(&ndisc_net_ops);
1957}