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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/*
2 * Neighbour Discovery for IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Mike Shaver <shaver@ingenia.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15/*
16 * Changes:
17 *
18 * Alexey I. Froloff : RFC6106 (DNSSL) support
19 * Pierre Ynard : export userland ND options
20 * through netlink (RDNSS support)
21 * Lars Fenneberg : fixed MTU setting on receipt
22 * of an RA.
23 * Janos Farkas : kmalloc failure checks
24 * Alexey Kuznetsov : state machine reworked
25 * and moved to net/core.
26 * Pekka Savola : RFC2461 validation
27 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
28 */
29
30#define pr_fmt(fmt) "ICMPv6: " fmt
31
32#include <linux/module.h>
33#include <linux/errno.h>
34#include <linux/types.h>
35#include <linux/socket.h>
36#include <linux/sockios.h>
37#include <linux/sched.h>
38#include <linux/net.h>
39#include <linux/in6.h>
40#include <linux/route.h>
41#include <linux/init.h>
42#include <linux/rcupdate.h>
43#include <linux/slab.h>
44#ifdef CONFIG_SYSCTL
45#include <linux/sysctl.h>
46#endif
47
48#include <linux/if_addr.h>
49#include <linux/if_arp.h>
50#include <linux/ipv6.h>
51#include <linux/icmpv6.h>
52#include <linux/jhash.h>
53
54#include <net/sock.h>
55#include <net/snmp.h>
56
57#include <net/ipv6.h>
58#include <net/protocol.h>
59#include <net/ndisc.h>
60#include <net/ip6_route.h>
61#include <net/addrconf.h>
62#include <net/icmp.h>
63
64#include <net/netlink.h>
65#include <linux/rtnetlink.h>
66
67#include <net/flow.h>
68#include <net/ip6_checksum.h>
69#include <net/inet_common.h>
70#include <linux/proc_fs.h>
71
72#include <linux/netfilter.h>
73#include <linux/netfilter_ipv6.h>
74
75static u32 ndisc_hash(const void *pkey,
76 const struct net_device *dev,
77 __u32 *hash_rnd);
78static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
79static int ndisc_constructor(struct neighbour *neigh);
80static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
81static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
82static int pndisc_constructor(struct pneigh_entry *n);
83static void pndisc_destructor(struct pneigh_entry *n);
84static void pndisc_redo(struct sk_buff *skb);
85
86static const struct neigh_ops ndisc_generic_ops = {
87 .family = AF_INET6,
88 .solicit = ndisc_solicit,
89 .error_report = ndisc_error_report,
90 .output = neigh_resolve_output,
91 .connected_output = neigh_connected_output,
92};
93
94static const struct neigh_ops ndisc_hh_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_resolve_output,
100};
101
102
103static const struct neigh_ops ndisc_direct_ops = {
104 .family = AF_INET6,
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
107};
108
109struct neigh_table nd_tbl = {
110 .family = AF_INET6,
111 .key_len = sizeof(struct in6_addr),
112 .protocol = cpu_to_be16(ETH_P_IPV6),
113 .hash = ndisc_hash,
114 .key_eq = ndisc_key_eq,
115 .constructor = ndisc_constructor,
116 .pconstructor = pndisc_constructor,
117 .pdestructor = pndisc_destructor,
118 .proxy_redo = pndisc_redo,
119 .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] = 64 * 1024,
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 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
200}
201
202static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
203 struct nd_opt_hdr *cur,
204 struct nd_opt_hdr *end)
205{
206 if (!cur || !end || cur >= end)
207 return NULL;
208 do {
209 cur = ((void *)cur) + (cur->nd_opt_len << 3);
210 } while (cur < end && !ndisc_is_useropt(dev, cur));
211 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
212}
213
214struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
215 u8 *opt, int opt_len,
216 struct ndisc_options *ndopts)
217{
218 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
219
220 if (!nd_opt || opt_len < 0 || !ndopts)
221 return NULL;
222 memset(ndopts, 0, sizeof(*ndopts));
223 while (opt_len) {
224 int l;
225 if (opt_len < sizeof(struct nd_opt_hdr))
226 return NULL;
227 l = nd_opt->nd_opt_len << 3;
228 if (opt_len < l || l == 0)
229 return NULL;
230 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
231 goto next_opt;
232 switch (nd_opt->nd_opt_type) {
233 case ND_OPT_SOURCE_LL_ADDR:
234 case ND_OPT_TARGET_LL_ADDR:
235 case ND_OPT_MTU:
236 case ND_OPT_NONCE:
237 case ND_OPT_REDIRECT_HDR:
238 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
239 ND_PRINTK(2, warn,
240 "%s: duplicated ND6 option found: type=%d\n",
241 __func__, nd_opt->nd_opt_type);
242 } else {
243 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
244 }
245 break;
246 case ND_OPT_PREFIX_INFO:
247 ndopts->nd_opts_pi_end = nd_opt;
248 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
249 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
250 break;
251#ifdef CONFIG_IPV6_ROUTE_INFO
252 case ND_OPT_ROUTE_INFO:
253 ndopts->nd_opts_ri_end = nd_opt;
254 if (!ndopts->nd_opts_ri)
255 ndopts->nd_opts_ri = nd_opt;
256 break;
257#endif
258 default:
259 if (ndisc_is_useropt(dev, nd_opt)) {
260 ndopts->nd_useropts_end = nd_opt;
261 if (!ndopts->nd_useropts)
262 ndopts->nd_useropts = nd_opt;
263 } else {
264 /*
265 * Unknown options must be silently ignored,
266 * to accommodate future extension to the
267 * protocol.
268 */
269 ND_PRINTK(2, notice,
270 "%s: ignored unsupported option; type=%d, len=%d\n",
271 __func__,
272 nd_opt->nd_opt_type,
273 nd_opt->nd_opt_len);
274 }
275 }
276next_opt:
277 opt_len -= l;
278 nd_opt = ((void *)nd_opt) + l;
279 }
280 return ndopts;
281}
282
283int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
284{
285 switch (dev->type) {
286 case ARPHRD_ETHER:
287 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
288 case ARPHRD_FDDI:
289 ipv6_eth_mc_map(addr, buf);
290 return 0;
291 case ARPHRD_ARCNET:
292 ipv6_arcnet_mc_map(addr, buf);
293 return 0;
294 case ARPHRD_INFINIBAND:
295 ipv6_ib_mc_map(addr, dev->broadcast, buf);
296 return 0;
297 case ARPHRD_IPGRE:
298 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
299 default:
300 if (dir) {
301 memcpy(buf, dev->broadcast, dev->addr_len);
302 return 0;
303 }
304 }
305 return -EINVAL;
306}
307EXPORT_SYMBOL(ndisc_mc_map);
308
309static u32 ndisc_hash(const void *pkey,
310 const struct net_device *dev,
311 __u32 *hash_rnd)
312{
313 return ndisc_hashfn(pkey, dev, hash_rnd);
314}
315
316static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
317{
318 return neigh_key_eq128(n, pkey);
319}
320
321static int ndisc_constructor(struct neighbour *neigh)
322{
323 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
324 struct net_device *dev = neigh->dev;
325 struct inet6_dev *in6_dev;
326 struct neigh_parms *parms;
327 bool is_multicast = ipv6_addr_is_multicast(addr);
328
329 in6_dev = in6_dev_get(dev);
330 if (!in6_dev) {
331 return -EINVAL;
332 }
333
334 parms = in6_dev->nd_parms;
335 __neigh_parms_put(neigh->parms);
336 neigh->parms = neigh_parms_clone(parms);
337
338 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
339 if (!dev->header_ops) {
340 neigh->nud_state = NUD_NOARP;
341 neigh->ops = &ndisc_direct_ops;
342 neigh->output = neigh_direct_output;
343 } else {
344 if (is_multicast) {
345 neigh->nud_state = NUD_NOARP;
346 ndisc_mc_map(addr, neigh->ha, dev, 1);
347 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
348 neigh->nud_state = NUD_NOARP;
349 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
350 if (dev->flags&IFF_LOOPBACK)
351 neigh->type = RTN_LOCAL;
352 } else if (dev->flags&IFF_POINTOPOINT) {
353 neigh->nud_state = NUD_NOARP;
354 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
355 }
356 if (dev->header_ops->cache)
357 neigh->ops = &ndisc_hh_ops;
358 else
359 neigh->ops = &ndisc_generic_ops;
360 if (neigh->nud_state&NUD_VALID)
361 neigh->output = neigh->ops->connected_output;
362 else
363 neigh->output = neigh->ops->output;
364 }
365 in6_dev_put(in6_dev);
366 return 0;
367}
368
369static int pndisc_constructor(struct pneigh_entry *n)
370{
371 struct in6_addr *addr = (struct in6_addr *)&n->key;
372 struct in6_addr maddr;
373 struct net_device *dev = n->dev;
374
375 if (!dev || !__in6_dev_get(dev))
376 return -EINVAL;
377 addrconf_addr_solict_mult(addr, &maddr);
378 ipv6_dev_mc_inc(dev, &maddr);
379 return 0;
380}
381
382static void pndisc_destructor(struct pneigh_entry *n)
383{
384 struct in6_addr *addr = (struct in6_addr *)&n->key;
385 struct in6_addr maddr;
386 struct net_device *dev = n->dev;
387
388 if (!dev || !__in6_dev_get(dev))
389 return;
390 addrconf_addr_solict_mult(addr, &maddr);
391 ipv6_dev_mc_dec(dev, &maddr);
392}
393
394static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
395 int len)
396{
397 int hlen = LL_RESERVED_SPACE(dev);
398 int tlen = dev->needed_tailroom;
399 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
400 struct sk_buff *skb;
401
402 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
403 if (!skb) {
404 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
405 __func__);
406 return NULL;
407 }
408
409 skb->protocol = htons(ETH_P_IPV6);
410 skb->dev = dev;
411
412 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
413 skb_reset_transport_header(skb);
414
415 /* Manually assign socket ownership as we avoid calling
416 * sock_alloc_send_pskb() to bypass wmem buffer limits
417 */
418 skb_set_owner_w(skb, sk);
419
420 return skb;
421}
422
423static void ip6_nd_hdr(struct sk_buff *skb,
424 const struct in6_addr *saddr,
425 const struct in6_addr *daddr,
426 int hop_limit, int len)
427{
428 struct ipv6hdr *hdr;
429
430 skb_push(skb, sizeof(*hdr));
431 skb_reset_network_header(skb);
432 hdr = ipv6_hdr(skb);
433
434 ip6_flow_hdr(hdr, 0, 0);
435
436 hdr->payload_len = htons(len);
437 hdr->nexthdr = IPPROTO_ICMPV6;
438 hdr->hop_limit = hop_limit;
439
440 hdr->saddr = *saddr;
441 hdr->daddr = *daddr;
442}
443
444static void ndisc_send_skb(struct sk_buff *skb,
445 const struct in6_addr *daddr,
446 const struct in6_addr *saddr)
447{
448 struct dst_entry *dst = skb_dst(skb);
449 struct net *net = dev_net(skb->dev);
450 struct sock *sk = net->ipv6.ndisc_sk;
451 struct inet6_dev *idev;
452 int err;
453 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
454 u8 type;
455
456 type = icmp6h->icmp6_type;
457
458 if (!dst) {
459 struct flowi6 fl6;
460 int oif = skb->dev->ifindex;
461
462 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
463 dst = icmp6_dst_alloc(skb->dev, &fl6);
464 if (IS_ERR(dst)) {
465 kfree_skb(skb);
466 return;
467 }
468
469 skb_dst_set(skb, dst);
470 }
471
472 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
473 IPPROTO_ICMPV6,
474 csum_partial(icmp6h,
475 skb->len, 0));
476
477 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
478
479 rcu_read_lock();
480 idev = __in6_dev_get(dst->dev);
481 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
482
483 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
484 net, sk, skb, NULL, dst->dev,
485 dst_output);
486 if (!err) {
487 ICMP6MSGOUT_INC_STATS(net, idev, type);
488 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
489 }
490
491 rcu_read_unlock();
492}
493
494void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
495 const struct in6_addr *solicited_addr,
496 bool router, bool solicited, bool override, bool inc_opt)
497{
498 struct sk_buff *skb;
499 struct in6_addr tmpaddr;
500 struct inet6_ifaddr *ifp;
501 const struct in6_addr *src_addr;
502 struct nd_msg *msg;
503 int optlen = 0;
504
505 /* for anycast or proxy, solicited_addr != src_addr */
506 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
507 if (ifp) {
508 src_addr = solicited_addr;
509 if (ifp->flags & IFA_F_OPTIMISTIC)
510 override = false;
511 inc_opt |= ifp->idev->cnf.force_tllao;
512 in6_ifa_put(ifp);
513 } else {
514 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
515 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
516 &tmpaddr))
517 return;
518 src_addr = &tmpaddr;
519 }
520
521 if (!dev->addr_len)
522 inc_opt = 0;
523 if (inc_opt)
524 optlen += ndisc_opt_addr_space(dev,
525 NDISC_NEIGHBOUR_ADVERTISEMENT);
526
527 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
528 if (!skb)
529 return;
530
531 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
532 *msg = (struct nd_msg) {
533 .icmph = {
534 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
535 .icmp6_router = router,
536 .icmp6_solicited = solicited,
537 .icmp6_override = override,
538 },
539 .target = *solicited_addr,
540 };
541
542 if (inc_opt)
543 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
544 dev->dev_addr,
545 NDISC_NEIGHBOUR_ADVERTISEMENT);
546
547 ndisc_send_skb(skb, daddr, src_addr);
548}
549
550static void ndisc_send_unsol_na(struct net_device *dev)
551{
552 struct inet6_dev *idev;
553 struct inet6_ifaddr *ifa;
554
555 idev = in6_dev_get(dev);
556 if (!idev)
557 return;
558
559 read_lock_bh(&idev->lock);
560 list_for_each_entry(ifa, &idev->addr_list, if_list) {
561 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
562 /*router=*/ !!idev->cnf.forwarding,
563 /*solicited=*/ false, /*override=*/ true,
564 /*inc_opt=*/ true);
565 }
566 read_unlock_bh(&idev->lock);
567
568 in6_dev_put(idev);
569}
570
571void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
572 const struct in6_addr *daddr, const struct in6_addr *saddr,
573 u64 nonce)
574{
575 struct sk_buff *skb;
576 struct in6_addr addr_buf;
577 int inc_opt = dev->addr_len;
578 int optlen = 0;
579 struct nd_msg *msg;
580
581 if (!saddr) {
582 if (ipv6_get_lladdr(dev, &addr_buf,
583 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
584 return;
585 saddr = &addr_buf;
586 }
587
588 if (ipv6_addr_any(saddr))
589 inc_opt = false;
590 if (inc_opt)
591 optlen += ndisc_opt_addr_space(dev,
592 NDISC_NEIGHBOUR_SOLICITATION);
593 if (nonce != 0)
594 optlen += 8;
595
596 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
597 if (!skb)
598 return;
599
600 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
601 *msg = (struct nd_msg) {
602 .icmph = {
603 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
604 },
605 .target = *solicit,
606 };
607
608 if (inc_opt)
609 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
610 dev->dev_addr,
611 NDISC_NEIGHBOUR_SOLICITATION);
612 if (nonce != 0) {
613 u8 *opt = skb_put(skb, 8);
614
615 opt[0] = ND_OPT_NONCE;
616 opt[1] = 8 >> 3;
617 memcpy(opt + 2, &nonce, 6);
618 }
619
620 ndisc_send_skb(skb, daddr, saddr);
621}
622
623void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
624 const struct in6_addr *daddr)
625{
626 struct sk_buff *skb;
627 struct rs_msg *msg;
628 int send_sllao = dev->addr_len;
629 int optlen = 0;
630
631#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
632 /*
633 * According to section 2.2 of RFC 4429, we must not
634 * send router solicitations with a sllao from
635 * optimistic addresses, but we may send the solicitation
636 * if we don't include the sllao. So here we check
637 * if our address is optimistic, and if so, we
638 * suppress the inclusion of the sllao.
639 */
640 if (send_sllao) {
641 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
642 dev, 1);
643 if (ifp) {
644 if (ifp->flags & IFA_F_OPTIMISTIC) {
645 send_sllao = 0;
646 }
647 in6_ifa_put(ifp);
648 } else {
649 send_sllao = 0;
650 }
651 }
652#endif
653 if (send_sllao)
654 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
655
656 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
657 if (!skb)
658 return;
659
660 msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
661 *msg = (struct rs_msg) {
662 .icmph = {
663 .icmp6_type = NDISC_ROUTER_SOLICITATION,
664 },
665 };
666
667 if (send_sllao)
668 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
669 dev->dev_addr,
670 NDISC_ROUTER_SOLICITATION);
671
672 ndisc_send_skb(skb, daddr, saddr);
673}
674
675
676static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
677{
678 /*
679 * "The sender MUST return an ICMP
680 * destination unreachable"
681 */
682 dst_link_failure(skb);
683 kfree_skb(skb);
684}
685
686/* Called with locked neigh: either read or both */
687
688static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
689{
690 struct in6_addr *saddr = NULL;
691 struct in6_addr mcaddr;
692 struct net_device *dev = neigh->dev;
693 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
694 int probes = atomic_read(&neigh->probes);
695
696 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
697 dev, 1,
698 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
699 saddr = &ipv6_hdr(skb)->saddr;
700 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
701 if (probes < 0) {
702 if (!(neigh->nud_state & NUD_VALID)) {
703 ND_PRINTK(1, dbg,
704 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
705 __func__, target);
706 }
707 ndisc_send_ns(dev, target, target, saddr, 0);
708 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
709 neigh_app_ns(neigh);
710 } else {
711 addrconf_addr_solict_mult(target, &mcaddr);
712 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
713 }
714}
715
716static int pndisc_is_router(const void *pkey,
717 struct net_device *dev)
718{
719 struct pneigh_entry *n;
720 int ret = -1;
721
722 read_lock_bh(&nd_tbl.lock);
723 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
724 if (n)
725 ret = !!(n->flags & NTF_ROUTER);
726 read_unlock_bh(&nd_tbl.lock);
727
728 return ret;
729}
730
731void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
732 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
733 struct ndisc_options *ndopts)
734{
735 neigh_update(neigh, lladdr, new, flags);
736 /* report ndisc ops about neighbour update */
737 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
738}
739
740static void ndisc_recv_ns(struct sk_buff *skb)
741{
742 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
743 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
744 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
745 u8 *lladdr = NULL;
746 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
747 offsetof(struct nd_msg, opt));
748 struct ndisc_options ndopts;
749 struct net_device *dev = skb->dev;
750 struct inet6_ifaddr *ifp;
751 struct inet6_dev *idev = NULL;
752 struct neighbour *neigh;
753 int dad = ipv6_addr_any(saddr);
754 bool inc;
755 int is_router = -1;
756 u64 nonce = 0;
757
758 if (skb->len < sizeof(struct nd_msg)) {
759 ND_PRINTK(2, warn, "NS: packet too short\n");
760 return;
761 }
762
763 if (ipv6_addr_is_multicast(&msg->target)) {
764 ND_PRINTK(2, warn, "NS: multicast target address\n");
765 return;
766 }
767
768 /*
769 * RFC2461 7.1.1:
770 * DAD has to be destined for solicited node multicast address.
771 */
772 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
773 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
774 return;
775 }
776
777 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
778 ND_PRINTK(2, warn, "NS: invalid ND options\n");
779 return;
780 }
781
782 if (ndopts.nd_opts_src_lladdr) {
783 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
784 if (!lladdr) {
785 ND_PRINTK(2, warn,
786 "NS: invalid link-layer address length\n");
787 return;
788 }
789
790 /* RFC2461 7.1.1:
791 * If the IP source address is the unspecified address,
792 * there MUST NOT be source link-layer address option
793 * in the message.
794 */
795 if (dad) {
796 ND_PRINTK(2, warn,
797 "NS: bad DAD packet (link-layer address option)\n");
798 return;
799 }
800 }
801 if (ndopts.nd_opts_nonce)
802 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
803
804 inc = ipv6_addr_is_multicast(daddr);
805
806 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
807 if (ifp) {
808have_ifp:
809 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
810 if (dad) {
811 if (nonce != 0 && ifp->dad_nonce == nonce) {
812 u8 *np = (u8 *)&nonce;
813 /* Matching nonce if looped back */
814 ND_PRINTK(2, notice,
815 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
816 ifp->idev->dev->name,
817 &ifp->addr, np);
818 goto out;
819 }
820 /*
821 * We are colliding with another node
822 * who is doing DAD
823 * so fail our DAD process
824 */
825 addrconf_dad_failure(ifp);
826 return;
827 } else {
828 /*
829 * This is not a dad solicitation.
830 * If we are an optimistic node,
831 * we should respond.
832 * Otherwise, we should ignore it.
833 */
834 if (!(ifp->flags & IFA_F_OPTIMISTIC))
835 goto out;
836 }
837 }
838
839 idev = ifp->idev;
840 } else {
841 struct net *net = dev_net(dev);
842
843 /* perhaps an address on the master device */
844 if (netif_is_l3_slave(dev)) {
845 struct net_device *mdev;
846
847 mdev = netdev_master_upper_dev_get_rcu(dev);
848 if (mdev) {
849 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
850 if (ifp)
851 goto have_ifp;
852 }
853 }
854
855 idev = in6_dev_get(dev);
856 if (!idev) {
857 /* XXX: count this drop? */
858 return;
859 }
860
861 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
862 (idev->cnf.forwarding &&
863 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
864 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
865 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
866 skb->pkt_type != PACKET_HOST &&
867 inc &&
868 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
869 /*
870 * for anycast or proxy,
871 * sender should delay its response
872 * by a random time between 0 and
873 * MAX_ANYCAST_DELAY_TIME seconds.
874 * (RFC2461) -- yoshfuji
875 */
876 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
877 if (n)
878 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
879 goto out;
880 }
881 } else
882 goto out;
883 }
884
885 if (is_router < 0)
886 is_router = idev->cnf.forwarding;
887
888 if (dad) {
889 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
890 !!is_router, false, (ifp != NULL), true);
891 goto out;
892 }
893
894 if (inc)
895 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
896 else
897 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
898
899 /*
900 * update / create cache entry
901 * for the source address
902 */
903 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
904 !inc || lladdr || !dev->addr_len);
905 if (neigh)
906 ndisc_update(dev, neigh, lladdr, NUD_STALE,
907 NEIGH_UPDATE_F_WEAK_OVERRIDE|
908 NEIGH_UPDATE_F_OVERRIDE,
909 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
910 if (neigh || !dev->header_ops) {
911 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
912 true, (ifp != NULL && inc), inc);
913 if (neigh)
914 neigh_release(neigh);
915 }
916
917out:
918 if (ifp)
919 in6_ifa_put(ifp);
920 else
921 in6_dev_put(idev);
922}
923
924static void ndisc_recv_na(struct sk_buff *skb)
925{
926 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
927 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
928 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
929 u8 *lladdr = NULL;
930 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
931 offsetof(struct nd_msg, opt));
932 struct ndisc_options ndopts;
933 struct net_device *dev = skb->dev;
934 struct inet6_dev *idev = __in6_dev_get(dev);
935 struct inet6_ifaddr *ifp;
936 struct neighbour *neigh;
937
938 if (skb->len < sizeof(struct nd_msg)) {
939 ND_PRINTK(2, warn, "NA: packet too short\n");
940 return;
941 }
942
943 if (ipv6_addr_is_multicast(&msg->target)) {
944 ND_PRINTK(2, warn, "NA: target address is multicast\n");
945 return;
946 }
947
948 if (ipv6_addr_is_multicast(daddr) &&
949 msg->icmph.icmp6_solicited) {
950 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
951 return;
952 }
953
954 /* For some 802.11 wireless deployments (and possibly other networks),
955 * there will be a NA proxy and unsolicitd packets are attacks
956 * and thus should not be accepted.
957 */
958 if (!msg->icmph.icmp6_solicited && idev &&
959 idev->cnf.drop_unsolicited_na)
960 return;
961
962 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
963 ND_PRINTK(2, warn, "NS: invalid ND option\n");
964 return;
965 }
966 if (ndopts.nd_opts_tgt_lladdr) {
967 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
968 if (!lladdr) {
969 ND_PRINTK(2, warn,
970 "NA: invalid link-layer address length\n");
971 return;
972 }
973 }
974 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
975 if (ifp) {
976 if (skb->pkt_type != PACKET_LOOPBACK
977 && (ifp->flags & IFA_F_TENTATIVE)) {
978 addrconf_dad_failure(ifp);
979 return;
980 }
981 /* What should we make now? The advertisement
982 is invalid, but ndisc specs say nothing
983 about it. It could be misconfiguration, or
984 an smart proxy agent tries to help us :-)
985
986 We should not print the error if NA has been
987 received from loopback - it is just our own
988 unsolicited advertisement.
989 */
990 if (skb->pkt_type != PACKET_LOOPBACK)
991 ND_PRINTK(1, warn,
992 "NA: someone advertises our address %pI6 on %s!\n",
993 &ifp->addr, ifp->idev->dev->name);
994 in6_ifa_put(ifp);
995 return;
996 }
997 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
998
999 if (neigh) {
1000 u8 old_flags = neigh->flags;
1001 struct net *net = dev_net(dev);
1002
1003 if (neigh->nud_state & NUD_FAILED)
1004 goto out;
1005
1006 /*
1007 * Don't update the neighbor cache entry on a proxy NA from
1008 * ourselves because either the proxied node is off link or it
1009 * has already sent a NA to us.
1010 */
1011 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1012 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1013 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1014 /* XXX: idev->cnf.proxy_ndp */
1015 goto out;
1016 }
1017
1018 ndisc_update(dev, neigh, lladdr,
1019 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1020 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1021 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1022 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1023 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1024 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1025
1026 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1027 /*
1028 * Change: router to host
1029 */
1030 rt6_clean_tohost(dev_net(dev), saddr);
1031 }
1032
1033out:
1034 neigh_release(neigh);
1035 }
1036}
1037
1038static void ndisc_recv_rs(struct sk_buff *skb)
1039{
1040 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1041 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1042 struct neighbour *neigh;
1043 struct inet6_dev *idev;
1044 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1045 struct ndisc_options ndopts;
1046 u8 *lladdr = NULL;
1047
1048 if (skb->len < sizeof(*rs_msg))
1049 return;
1050
1051 idev = __in6_dev_get(skb->dev);
1052 if (!idev) {
1053 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1054 return;
1055 }
1056
1057 /* Don't accept RS if we're not in router mode */
1058 if (!idev->cnf.forwarding)
1059 goto out;
1060
1061 /*
1062 * Don't update NCE if src = ::;
1063 * this implies that the source node has no ip address assigned yet.
1064 */
1065 if (ipv6_addr_any(saddr))
1066 goto out;
1067
1068 /* Parse ND options */
1069 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1070 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1071 goto out;
1072 }
1073
1074 if (ndopts.nd_opts_src_lladdr) {
1075 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1076 skb->dev);
1077 if (!lladdr)
1078 goto out;
1079 }
1080
1081 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1082 if (neigh) {
1083 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1084 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1085 NEIGH_UPDATE_F_OVERRIDE|
1086 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1087 NDISC_ROUTER_SOLICITATION, &ndopts);
1088 neigh_release(neigh);
1089 }
1090out:
1091 return;
1092}
1093
1094static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1095{
1096 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1097 struct sk_buff *skb;
1098 struct nlmsghdr *nlh;
1099 struct nduseroptmsg *ndmsg;
1100 struct net *net = dev_net(ra->dev);
1101 int err;
1102 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1103 + (opt->nd_opt_len << 3));
1104 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1105
1106 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1107 if (!skb) {
1108 err = -ENOBUFS;
1109 goto errout;
1110 }
1111
1112 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1113 if (!nlh) {
1114 goto nla_put_failure;
1115 }
1116
1117 ndmsg = nlmsg_data(nlh);
1118 ndmsg->nduseropt_family = AF_INET6;
1119 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1120 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1121 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1122 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1123
1124 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1125
1126 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1127 goto nla_put_failure;
1128 nlmsg_end(skb, nlh);
1129
1130 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1131 return;
1132
1133nla_put_failure:
1134 nlmsg_free(skb);
1135 err = -EMSGSIZE;
1136errout:
1137 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1138}
1139
1140static void ndisc_router_discovery(struct sk_buff *skb)
1141{
1142 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1143 struct neighbour *neigh = NULL;
1144 struct inet6_dev *in6_dev;
1145 struct rt6_info *rt = NULL;
1146 int lifetime;
1147 struct ndisc_options ndopts;
1148 int optlen;
1149 unsigned int pref = 0;
1150 __u32 old_if_flags;
1151 bool send_ifinfo_notify = false;
1152
1153 __u8 *opt = (__u8 *)(ra_msg + 1);
1154
1155 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1156 sizeof(struct ra_msg);
1157
1158 ND_PRINTK(2, info,
1159 "RA: %s, dev: %s\n",
1160 __func__, skb->dev->name);
1161 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1162 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1163 return;
1164 }
1165 if (optlen < 0) {
1166 ND_PRINTK(2, warn, "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_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1173 return;
1174 }
1175#endif
1176
1177 /*
1178 * set the RA_RECV flag in the interface
1179 */
1180
1181 in6_dev = __in6_dev_get(skb->dev);
1182 if (!in6_dev) {
1183 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1184 skb->dev->name);
1185 return;
1186 }
1187
1188 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1189 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1190 return;
1191 }
1192
1193 if (!ipv6_accept_ra(in6_dev)) {
1194 ND_PRINTK(2, info,
1195 "RA: %s, did not accept ra for dev: %s\n",
1196 __func__, skb->dev->name);
1197 goto skip_linkparms;
1198 }
1199
1200#ifdef CONFIG_IPV6_NDISC_NODETYPE
1201 /* skip link-specific parameters from interior routers */
1202 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1203 ND_PRINTK(2, info,
1204 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1205 __func__, skb->dev->name);
1206 goto skip_linkparms;
1207 }
1208#endif
1209
1210 if (in6_dev->if_flags & IF_RS_SENT) {
1211 /*
1212 * flag that an RA was received after an RS was sent
1213 * out on this interface.
1214 */
1215 in6_dev->if_flags |= IF_RA_RCVD;
1216 }
1217
1218 /*
1219 * Remember the managed/otherconf flags from most recently
1220 * received RA message (RFC 2462) -- yoshfuji
1221 */
1222 old_if_flags = in6_dev->if_flags;
1223 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1224 IF_RA_OTHERCONF)) |
1225 (ra_msg->icmph.icmp6_addrconf_managed ?
1226 IF_RA_MANAGED : 0) |
1227 (ra_msg->icmph.icmp6_addrconf_other ?
1228 IF_RA_OTHERCONF : 0);
1229
1230 if (old_if_flags != in6_dev->if_flags)
1231 send_ifinfo_notify = true;
1232
1233 if (!in6_dev->cnf.accept_ra_defrtr) {
1234 ND_PRINTK(2, info,
1235 "RA: %s, defrtr is false for dev: %s\n",
1236 __func__, skb->dev->name);
1237 goto skip_defrtr;
1238 }
1239
1240 /* Do not accept RA with source-addr found on local machine unless
1241 * accept_ra_from_local is set to true.
1242 */
1243 if (!in6_dev->cnf.accept_ra_from_local &&
1244 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1245 in6_dev->dev, 0)) {
1246 ND_PRINTK(2, info,
1247 "RA from local address detected on dev: %s: default router ignored\n",
1248 skb->dev->name);
1249 goto skip_defrtr;
1250 }
1251
1252 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1253
1254#ifdef CONFIG_IPV6_ROUTER_PREF
1255 pref = ra_msg->icmph.icmp6_router_pref;
1256 /* 10b is handled as if it were 00b (medium) */
1257 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1258 !in6_dev->cnf.accept_ra_rtr_pref)
1259 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1260#endif
1261
1262 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1263
1264 if (rt) {
1265 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1266 if (!neigh) {
1267 ND_PRINTK(0, err,
1268 "RA: %s got default router without neighbour\n",
1269 __func__);
1270 ip6_rt_put(rt);
1271 return;
1272 }
1273 }
1274 if (rt && lifetime == 0) {
1275 ip6_del_rt(rt);
1276 rt = NULL;
1277 }
1278
1279 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1280 rt, lifetime, skb->dev->name);
1281 if (!rt && lifetime) {
1282 ND_PRINTK(3, info, "RA: adding default router\n");
1283
1284 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1285 if (!rt) {
1286 ND_PRINTK(0, err,
1287 "RA: %s failed to add default route\n",
1288 __func__);
1289 return;
1290 }
1291
1292 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1293 if (!neigh) {
1294 ND_PRINTK(0, err,
1295 "RA: %s got default router without neighbour\n",
1296 __func__);
1297 ip6_rt_put(rt);
1298 return;
1299 }
1300 neigh->flags |= NTF_ROUTER;
1301 } else if (rt) {
1302 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1303 }
1304
1305 if (rt)
1306 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1307 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1308 ra_msg->icmph.icmp6_hop_limit) {
1309 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1310 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1311 if (rt)
1312 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1313 ra_msg->icmph.icmp6_hop_limit);
1314 } else {
1315 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1316 }
1317 }
1318
1319skip_defrtr:
1320
1321 /*
1322 * Update Reachable Time and Retrans Timer
1323 */
1324
1325 if (in6_dev->nd_parms) {
1326 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1327
1328 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1329 rtime = (rtime*HZ)/1000;
1330 if (rtime < HZ/10)
1331 rtime = HZ/10;
1332 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1333 in6_dev->tstamp = jiffies;
1334 send_ifinfo_notify = true;
1335 }
1336
1337 rtime = ntohl(ra_msg->reachable_time);
1338 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1339 rtime = (rtime*HZ)/1000;
1340
1341 if (rtime < HZ/10)
1342 rtime = HZ/10;
1343
1344 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1345 NEIGH_VAR_SET(in6_dev->nd_parms,
1346 BASE_REACHABLE_TIME, rtime);
1347 NEIGH_VAR_SET(in6_dev->nd_parms,
1348 GC_STALETIME, 3 * rtime);
1349 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1350 in6_dev->tstamp = jiffies;
1351 send_ifinfo_notify = true;
1352 }
1353 }
1354 }
1355
1356 /*
1357 * Send a notify if RA changed managed/otherconf flags or timer settings
1358 */
1359 if (send_ifinfo_notify)
1360 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1361
1362skip_linkparms:
1363
1364 /*
1365 * Process options.
1366 */
1367
1368 if (!neigh)
1369 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1370 skb->dev, 1);
1371 if (neigh) {
1372 u8 *lladdr = NULL;
1373 if (ndopts.nd_opts_src_lladdr) {
1374 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1375 skb->dev);
1376 if (!lladdr) {
1377 ND_PRINTK(2, warn,
1378 "RA: invalid link-layer address length\n");
1379 goto out;
1380 }
1381 }
1382 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1383 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1384 NEIGH_UPDATE_F_OVERRIDE|
1385 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1386 NEIGH_UPDATE_F_ISROUTER,
1387 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1388 }
1389
1390 if (!ipv6_accept_ra(in6_dev)) {
1391 ND_PRINTK(2, info,
1392 "RA: %s, accept_ra is false for dev: %s\n",
1393 __func__, skb->dev->name);
1394 goto out;
1395 }
1396
1397#ifdef CONFIG_IPV6_ROUTE_INFO
1398 if (!in6_dev->cnf.accept_ra_from_local &&
1399 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1400 in6_dev->dev, 0)) {
1401 ND_PRINTK(2, info,
1402 "RA from local address detected on dev: %s: router info ignored.\n",
1403 skb->dev->name);
1404 goto skip_routeinfo;
1405 }
1406
1407 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1408 struct nd_opt_hdr *p;
1409 for (p = ndopts.nd_opts_ri;
1410 p;
1411 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1412 struct route_info *ri = (struct route_info *)p;
1413#ifdef CONFIG_IPV6_NDISC_NODETYPE
1414 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1415 ri->prefix_len == 0)
1416 continue;
1417#endif
1418 if (ri->prefix_len == 0 &&
1419 !in6_dev->cnf.accept_ra_defrtr)
1420 continue;
1421 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1422 continue;
1423 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1424 &ipv6_hdr(skb)->saddr);
1425 }
1426 }
1427
1428skip_routeinfo:
1429#endif
1430
1431#ifdef CONFIG_IPV6_NDISC_NODETYPE
1432 /* skip link-specific ndopts from interior routers */
1433 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1434 ND_PRINTK(2, info,
1435 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1436 __func__, skb->dev->name);
1437 goto out;
1438 }
1439#endif
1440
1441 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1442 struct nd_opt_hdr *p;
1443 for (p = ndopts.nd_opts_pi;
1444 p;
1445 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1446 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1447 (p->nd_opt_len) << 3,
1448 ndopts.nd_opts_src_lladdr != NULL);
1449 }
1450 }
1451
1452 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1453 __be32 n;
1454 u32 mtu;
1455
1456 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1457 mtu = ntohl(n);
1458
1459 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1460 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1461 } else if (in6_dev->cnf.mtu6 != mtu) {
1462 in6_dev->cnf.mtu6 = mtu;
1463
1464 if (rt)
1465 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1466
1467 rt6_mtu_change(skb->dev, mtu);
1468 }
1469 }
1470
1471 if (ndopts.nd_useropts) {
1472 struct nd_opt_hdr *p;
1473 for (p = ndopts.nd_useropts;
1474 p;
1475 p = ndisc_next_useropt(skb->dev, p,
1476 ndopts.nd_useropts_end)) {
1477 ndisc_ra_useropt(skb, p);
1478 }
1479 }
1480
1481 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1482 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1483 }
1484out:
1485 ip6_rt_put(rt);
1486 if (neigh)
1487 neigh_release(neigh);
1488}
1489
1490static void ndisc_redirect_rcv(struct sk_buff *skb)
1491{
1492 u8 *hdr;
1493 struct ndisc_options ndopts;
1494 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1495 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1496 offsetof(struct rd_msg, opt));
1497
1498#ifdef CONFIG_IPV6_NDISC_NODETYPE
1499 switch (skb->ndisc_nodetype) {
1500 case NDISC_NODETYPE_HOST:
1501 case NDISC_NODETYPE_NODEFAULT:
1502 ND_PRINTK(2, warn,
1503 "Redirect: from host or unauthorized router\n");
1504 return;
1505 }
1506#endif
1507
1508 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1509 ND_PRINTK(2, warn,
1510 "Redirect: source address is not link-local\n");
1511 return;
1512 }
1513
1514 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1515 return;
1516
1517 if (!ndopts.nd_opts_rh) {
1518 ip6_redirect_no_header(skb, dev_net(skb->dev),
1519 skb->dev->ifindex, 0);
1520 return;
1521 }
1522
1523 hdr = (u8 *)ndopts.nd_opts_rh;
1524 hdr += 8;
1525 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1526 return;
1527
1528 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1529}
1530
1531static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1532 struct sk_buff *orig_skb,
1533 int rd_len)
1534{
1535 u8 *opt = skb_put(skb, rd_len);
1536
1537 memset(opt, 0, 8);
1538 *(opt++) = ND_OPT_REDIRECT_HDR;
1539 *(opt++) = (rd_len >> 3);
1540 opt += 6;
1541
1542 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
1543}
1544
1545void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1546{
1547 struct net_device *dev = skb->dev;
1548 struct net *net = dev_net(dev);
1549 struct sock *sk = net->ipv6.ndisc_sk;
1550 int optlen = 0;
1551 struct inet_peer *peer;
1552 struct sk_buff *buff;
1553 struct rd_msg *msg;
1554 struct in6_addr saddr_buf;
1555 struct rt6_info *rt;
1556 struct dst_entry *dst;
1557 struct flowi6 fl6;
1558 int rd_len;
1559 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1560 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1561 bool ret;
1562
1563 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1564 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1565 dev->name);
1566 return;
1567 }
1568
1569 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1570 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1571 ND_PRINTK(2, warn,
1572 "Redirect: target address is not link-local unicast\n");
1573 return;
1574 }
1575
1576 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1577 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1578
1579 dst = ip6_route_output(net, NULL, &fl6);
1580 if (dst->error) {
1581 dst_release(dst);
1582 return;
1583 }
1584 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1585 if (IS_ERR(dst))
1586 return;
1587
1588 rt = (struct rt6_info *) dst;
1589
1590 if (rt->rt6i_flags & RTF_GATEWAY) {
1591 ND_PRINTK(2, warn,
1592 "Redirect: destination is not a neighbour\n");
1593 goto release;
1594 }
1595 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1596 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1597 if (peer)
1598 inet_putpeer(peer);
1599 if (!ret)
1600 goto release;
1601
1602 if (dev->addr_len) {
1603 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1604 if (!neigh) {
1605 ND_PRINTK(2, warn,
1606 "Redirect: no neigh for target address\n");
1607 goto release;
1608 }
1609
1610 read_lock_bh(&neigh->lock);
1611 if (neigh->nud_state & NUD_VALID) {
1612 memcpy(ha_buf, neigh->ha, dev->addr_len);
1613 read_unlock_bh(&neigh->lock);
1614 ha = ha_buf;
1615 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1616 ops_data_buf,
1617 &ops_data);
1618 } else
1619 read_unlock_bh(&neigh->lock);
1620
1621 neigh_release(neigh);
1622 }
1623
1624 rd_len = min_t(unsigned int,
1625 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1626 skb->len + 8);
1627 rd_len &= ~0x7;
1628 optlen += rd_len;
1629
1630 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1631 if (!buff)
1632 goto release;
1633
1634 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1635 *msg = (struct rd_msg) {
1636 .icmph = {
1637 .icmp6_type = NDISC_REDIRECT,
1638 },
1639 .target = *target,
1640 .dest = ipv6_hdr(skb)->daddr,
1641 };
1642
1643 /*
1644 * include target_address option
1645 */
1646
1647 if (ha)
1648 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1649
1650 /*
1651 * build redirect option and copy skb over to the new packet.
1652 */
1653
1654 if (rd_len)
1655 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1656
1657 skb_dst_set(buff, dst);
1658 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1659 return;
1660
1661release:
1662 dst_release(dst);
1663}
1664
1665static void pndisc_redo(struct sk_buff *skb)
1666{
1667 ndisc_recv_ns(skb);
1668 kfree_skb(skb);
1669}
1670
1671static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1672{
1673 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1674
1675 if (!idev)
1676 return true;
1677 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1678 idev->cnf.suppress_frag_ndisc) {
1679 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1680 return true;
1681 }
1682 return false;
1683}
1684
1685int ndisc_rcv(struct sk_buff *skb)
1686{
1687 struct nd_msg *msg;
1688
1689 if (ndisc_suppress_frag_ndisc(skb))
1690 return 0;
1691
1692 if (skb_linearize(skb))
1693 return 0;
1694
1695 msg = (struct nd_msg *)skb_transport_header(skb);
1696
1697 __skb_push(skb, skb->data - skb_transport_header(skb));
1698
1699 if (ipv6_hdr(skb)->hop_limit != 255) {
1700 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1701 ipv6_hdr(skb)->hop_limit);
1702 return 0;
1703 }
1704
1705 if (msg->icmph.icmp6_code != 0) {
1706 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1707 msg->icmph.icmp6_code);
1708 return 0;
1709 }
1710
1711 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1712
1713 switch (msg->icmph.icmp6_type) {
1714 case NDISC_NEIGHBOUR_SOLICITATION:
1715 ndisc_recv_ns(skb);
1716 break;
1717
1718 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1719 ndisc_recv_na(skb);
1720 break;
1721
1722 case NDISC_ROUTER_SOLICITATION:
1723 ndisc_recv_rs(skb);
1724 break;
1725
1726 case NDISC_ROUTER_ADVERTISEMENT:
1727 ndisc_router_discovery(skb);
1728 break;
1729
1730 case NDISC_REDIRECT:
1731 ndisc_redirect_rcv(skb);
1732 break;
1733 }
1734
1735 return 0;
1736}
1737
1738static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1739{
1740 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1741 struct netdev_notifier_change_info *change_info;
1742 struct net *net = dev_net(dev);
1743 struct inet6_dev *idev;
1744
1745 switch (event) {
1746 case NETDEV_CHANGEADDR:
1747 neigh_changeaddr(&nd_tbl, dev);
1748 fib6_run_gc(0, net, false);
1749 idev = in6_dev_get(dev);
1750 if (!idev)
1751 break;
1752 if (idev->cnf.ndisc_notify)
1753 ndisc_send_unsol_na(dev);
1754 in6_dev_put(idev);
1755 break;
1756 case NETDEV_CHANGE:
1757 change_info = ptr;
1758 if (change_info->flags_changed & IFF_NOARP)
1759 neigh_changeaddr(&nd_tbl, dev);
1760 break;
1761 case NETDEV_DOWN:
1762 neigh_ifdown(&nd_tbl, dev);
1763 fib6_run_gc(0, net, false);
1764 break;
1765 case NETDEV_NOTIFY_PEERS:
1766 ndisc_send_unsol_na(dev);
1767 break;
1768 default:
1769 break;
1770 }
1771
1772 return NOTIFY_DONE;
1773}
1774
1775static struct notifier_block ndisc_netdev_notifier = {
1776 .notifier_call = ndisc_netdev_event,
1777};
1778
1779#ifdef CONFIG_SYSCTL
1780static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1781 const char *func, const char *dev_name)
1782{
1783 static char warncomm[TASK_COMM_LEN];
1784 static int warned;
1785 if (strcmp(warncomm, current->comm) && warned < 5) {
1786 strcpy(warncomm, current->comm);
1787 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1788 warncomm, func,
1789 dev_name, ctl->procname,
1790 dev_name, ctl->procname);
1791 warned++;
1792 }
1793}
1794
1795int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1796{
1797 struct net_device *dev = ctl->extra1;
1798 struct inet6_dev *idev;
1799 int ret;
1800
1801 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1802 (strcmp(ctl->procname, "base_reachable_time") == 0))
1803 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1804
1805 if (strcmp(ctl->procname, "retrans_time") == 0)
1806 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1807
1808 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1809 ret = neigh_proc_dointvec_jiffies(ctl, write,
1810 buffer, lenp, ppos);
1811
1812 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1813 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1814 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1815 buffer, lenp, ppos);
1816 else
1817 ret = -1;
1818
1819 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1820 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1821 idev->nd_parms->reachable_time =
1822 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1823 idev->tstamp = jiffies;
1824 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1825 in6_dev_put(idev);
1826 }
1827 return ret;
1828}
1829
1830
1831#endif
1832
1833static int __net_init ndisc_net_init(struct net *net)
1834{
1835 struct ipv6_pinfo *np;
1836 struct sock *sk;
1837 int err;
1838
1839 err = inet_ctl_sock_create(&sk, PF_INET6,
1840 SOCK_RAW, IPPROTO_ICMPV6, net);
1841 if (err < 0) {
1842 ND_PRINTK(0, err,
1843 "NDISC: Failed to initialize the control socket (err %d)\n",
1844 err);
1845 return err;
1846 }
1847
1848 net->ipv6.ndisc_sk = sk;
1849
1850 np = inet6_sk(sk);
1851 np->hop_limit = 255;
1852 /* Do not loopback ndisc messages */
1853 np->mc_loop = 0;
1854
1855 return 0;
1856}
1857
1858static void __net_exit ndisc_net_exit(struct net *net)
1859{
1860 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1861}
1862
1863static struct pernet_operations ndisc_net_ops = {
1864 .init = ndisc_net_init,
1865 .exit = ndisc_net_exit,
1866};
1867
1868int __init ndisc_init(void)
1869{
1870 int err;
1871
1872 err = register_pernet_subsys(&ndisc_net_ops);
1873 if (err)
1874 return err;
1875 /*
1876 * Initialize the neighbour table
1877 */
1878 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1879
1880#ifdef CONFIG_SYSCTL
1881 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1882 ndisc_ifinfo_sysctl_change);
1883 if (err)
1884 goto out_unregister_pernet;
1885out:
1886#endif
1887 return err;
1888
1889#ifdef CONFIG_SYSCTL
1890out_unregister_pernet:
1891 unregister_pernet_subsys(&ndisc_net_ops);
1892 goto out;
1893#endif
1894}
1895
1896int __init ndisc_late_init(void)
1897{
1898 return register_netdevice_notifier(&ndisc_netdev_notifier);
1899}
1900
1901void ndisc_late_cleanup(void)
1902{
1903 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1904}
1905
1906void ndisc_cleanup(void)
1907{
1908#ifdef CONFIG_SYSCTL
1909 neigh_sysctl_unregister(&nd_tbl.parms);
1910#endif
1911 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1912 unregister_pernet_subsys(&ndisc_net_ops);
1913}