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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 * Alexey I. Froloff : RFC6106 (DNSSL) support
19 * Pierre Ynard : export userland ND options
20 * through netlink (RDNSS support)
21 * Lars Fenneberg : fixed MTU setting on receipt
22 * of an RA.
23 * Janos Farkas : kmalloc failure checks
24 * Alexey Kuznetsov : state machine reworked
25 * and moved to net/core.
26 * Pekka Savola : RFC2461 validation
27 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
28 */
29
30#define pr_fmt(fmt) "ICMPv6: " fmt
31
32#include <linux/module.h>
33#include <linux/errno.h>
34#include <linux/types.h>
35#include <linux/socket.h>
36#include <linux/sockios.h>
37#include <linux/sched.h>
38#include <linux/net.h>
39#include <linux/in6.h>
40#include <linux/route.h>
41#include <linux/init.h>
42#include <linux/rcupdate.h>
43#include <linux/slab.h>
44#ifdef CONFIG_SYSCTL
45#include <linux/sysctl.h>
46#endif
47
48#include <linux/if_addr.h>
49#include <linux/if_arp.h>
50#include <linux/ipv6.h>
51#include <linux/icmpv6.h>
52#include <linux/jhash.h>
53
54#include <net/sock.h>
55#include <net/snmp.h>
56
57#include <net/ipv6.h>
58#include <net/protocol.h>
59#include <net/ndisc.h>
60#include <net/ip6_route.h>
61#include <net/addrconf.h>
62#include <net/icmp.h>
63
64#include <net/netlink.h>
65#include <linux/rtnetlink.h>
66
67#include <net/flow.h>
68#include <net/ip6_checksum.h>
69#include <net/inet_common.h>
70#include <linux/proc_fs.h>
71
72#include <linux/netfilter.h>
73#include <linux/netfilter_ipv6.h>
74
75/* Set to 3 to get tracing... */
76#define ND_DEBUG 1
77
78#define ND_PRINTK(val, level, fmt, ...) \
79do { \
80 if (val <= ND_DEBUG) \
81 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \
82} while (0)
83
84static u32 ndisc_hash(const void *pkey,
85 const struct net_device *dev,
86 __u32 *hash_rnd);
87static int ndisc_constructor(struct neighbour *neigh);
88static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
89static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
90static int pndisc_constructor(struct pneigh_entry *n);
91static void pndisc_destructor(struct pneigh_entry *n);
92static void pndisc_redo(struct sk_buff *skb);
93
94static const struct neigh_ops ndisc_generic_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_connected_output,
100};
101
102static const struct neigh_ops ndisc_hh_ops = {
103 .family = AF_INET6,
104 .solicit = ndisc_solicit,
105 .error_report = ndisc_error_report,
106 .output = neigh_resolve_output,
107 .connected_output = neigh_resolve_output,
108};
109
110
111static const struct neigh_ops ndisc_direct_ops = {
112 .family = AF_INET6,
113 .output = neigh_direct_output,
114 .connected_output = neigh_direct_output,
115};
116
117struct neigh_table nd_tbl = {
118 .family = AF_INET6,
119 .key_len = sizeof(struct in6_addr),
120 .hash = ndisc_hash,
121 .constructor = ndisc_constructor,
122 .pconstructor = pndisc_constructor,
123 .pdestructor = pndisc_destructor,
124 .proxy_redo = pndisc_redo,
125 .id = "ndisc_cache",
126 .parms = {
127 .tbl = &nd_tbl,
128 .reachable_time = ND_REACHABLE_TIME,
129 .data = {
130 [NEIGH_VAR_MCAST_PROBES] = 3,
131 [NEIGH_VAR_UCAST_PROBES] = 3,
132 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
133 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
134 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
135 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
136 [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024,
137 [NEIGH_VAR_PROXY_QLEN] = 64,
138 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
139 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
140 },
141 },
142 .gc_interval = 30 * HZ,
143 .gc_thresh1 = 128,
144 .gc_thresh2 = 512,
145 .gc_thresh3 = 1024,
146};
147
148static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data)
149{
150 int pad = ndisc_addr_option_pad(skb->dev->type);
151 int data_len = skb->dev->addr_len;
152 int space = ndisc_opt_addr_space(skb->dev);
153 u8 *opt = skb_put(skb, space);
154
155 opt[0] = type;
156 opt[1] = space>>3;
157
158 memset(opt + 2, 0, pad);
159 opt += pad;
160 space -= pad;
161
162 memcpy(opt+2, data, data_len);
163 data_len += 2;
164 opt += data_len;
165 if ((space -= data_len) > 0)
166 memset(opt, 0, space);
167}
168
169static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
170 struct nd_opt_hdr *end)
171{
172 int type;
173 if (!cur || !end || cur >= end)
174 return NULL;
175 type = cur->nd_opt_type;
176 do {
177 cur = ((void *)cur) + (cur->nd_opt_len << 3);
178 } while(cur < end && cur->nd_opt_type != type);
179 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
180}
181
182static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
183{
184 return opt->nd_opt_type == ND_OPT_RDNSS ||
185 opt->nd_opt_type == ND_OPT_DNSSL;
186}
187
188static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
189 struct nd_opt_hdr *end)
190{
191 if (!cur || !end || cur >= end)
192 return NULL;
193 do {
194 cur = ((void *)cur) + (cur->nd_opt_len << 3);
195 } while(cur < end && !ndisc_is_useropt(cur));
196 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
197}
198
199struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
200 struct ndisc_options *ndopts)
201{
202 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
203
204 if (!nd_opt || opt_len < 0 || !ndopts)
205 return NULL;
206 memset(ndopts, 0, sizeof(*ndopts));
207 while (opt_len) {
208 int l;
209 if (opt_len < sizeof(struct nd_opt_hdr))
210 return NULL;
211 l = nd_opt->nd_opt_len << 3;
212 if (opt_len < l || l == 0)
213 return NULL;
214 switch (nd_opt->nd_opt_type) {
215 case ND_OPT_SOURCE_LL_ADDR:
216 case ND_OPT_TARGET_LL_ADDR:
217 case ND_OPT_MTU:
218 case ND_OPT_REDIRECT_HDR:
219 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
220 ND_PRINTK(2, warn,
221 "%s: duplicated ND6 option found: type=%d\n",
222 __func__, nd_opt->nd_opt_type);
223 } else {
224 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
225 }
226 break;
227 case ND_OPT_PREFIX_INFO:
228 ndopts->nd_opts_pi_end = nd_opt;
229 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
230 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
231 break;
232#ifdef CONFIG_IPV6_ROUTE_INFO
233 case ND_OPT_ROUTE_INFO:
234 ndopts->nd_opts_ri_end = nd_opt;
235 if (!ndopts->nd_opts_ri)
236 ndopts->nd_opts_ri = nd_opt;
237 break;
238#endif
239 default:
240 if (ndisc_is_useropt(nd_opt)) {
241 ndopts->nd_useropts_end = nd_opt;
242 if (!ndopts->nd_useropts)
243 ndopts->nd_useropts = nd_opt;
244 } else {
245 /*
246 * Unknown options must be silently ignored,
247 * to accommodate future extension to the
248 * protocol.
249 */
250 ND_PRINTK(2, notice,
251 "%s: ignored unsupported option; type=%d, len=%d\n",
252 __func__,
253 nd_opt->nd_opt_type,
254 nd_opt->nd_opt_len);
255 }
256 }
257 opt_len -= l;
258 nd_opt = ((void *)nd_opt) + l;
259 }
260 return ndopts;
261}
262
263int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
264{
265 switch (dev->type) {
266 case ARPHRD_ETHER:
267 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
268 case ARPHRD_FDDI:
269 ipv6_eth_mc_map(addr, buf);
270 return 0;
271 case ARPHRD_ARCNET:
272 ipv6_arcnet_mc_map(addr, buf);
273 return 0;
274 case ARPHRD_INFINIBAND:
275 ipv6_ib_mc_map(addr, dev->broadcast, buf);
276 return 0;
277 case ARPHRD_IPGRE:
278 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
279 default:
280 if (dir) {
281 memcpy(buf, dev->broadcast, dev->addr_len);
282 return 0;
283 }
284 }
285 return -EINVAL;
286}
287
288EXPORT_SYMBOL(ndisc_mc_map);
289
290static u32 ndisc_hash(const void *pkey,
291 const struct net_device *dev,
292 __u32 *hash_rnd)
293{
294 return ndisc_hashfn(pkey, dev, hash_rnd);
295}
296
297static int ndisc_constructor(struct neighbour *neigh)
298{
299 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
300 struct net_device *dev = neigh->dev;
301 struct inet6_dev *in6_dev;
302 struct neigh_parms *parms;
303 bool is_multicast = ipv6_addr_is_multicast(addr);
304
305 in6_dev = in6_dev_get(dev);
306 if (in6_dev == NULL) {
307 return -EINVAL;
308 }
309
310 parms = in6_dev->nd_parms;
311 __neigh_parms_put(neigh->parms);
312 neigh->parms = neigh_parms_clone(parms);
313
314 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
315 if (!dev->header_ops) {
316 neigh->nud_state = NUD_NOARP;
317 neigh->ops = &ndisc_direct_ops;
318 neigh->output = neigh_direct_output;
319 } else {
320 if (is_multicast) {
321 neigh->nud_state = NUD_NOARP;
322 ndisc_mc_map(addr, neigh->ha, dev, 1);
323 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
324 neigh->nud_state = NUD_NOARP;
325 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
326 if (dev->flags&IFF_LOOPBACK)
327 neigh->type = RTN_LOCAL;
328 } else if (dev->flags&IFF_POINTOPOINT) {
329 neigh->nud_state = NUD_NOARP;
330 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
331 }
332 if (dev->header_ops->cache)
333 neigh->ops = &ndisc_hh_ops;
334 else
335 neigh->ops = &ndisc_generic_ops;
336 if (neigh->nud_state&NUD_VALID)
337 neigh->output = neigh->ops->connected_output;
338 else
339 neigh->output = neigh->ops->output;
340 }
341 in6_dev_put(in6_dev);
342 return 0;
343}
344
345static int pndisc_constructor(struct pneigh_entry *n)
346{
347 struct in6_addr *addr = (struct in6_addr*)&n->key;
348 struct in6_addr maddr;
349 struct net_device *dev = n->dev;
350
351 if (dev == NULL || __in6_dev_get(dev) == NULL)
352 return -EINVAL;
353 addrconf_addr_solict_mult(addr, &maddr);
354 ipv6_dev_mc_inc(dev, &maddr);
355 return 0;
356}
357
358static void pndisc_destructor(struct pneigh_entry *n)
359{
360 struct in6_addr *addr = (struct in6_addr*)&n->key;
361 struct in6_addr maddr;
362 struct net_device *dev = n->dev;
363
364 if (dev == NULL || __in6_dev_get(dev) == NULL)
365 return;
366 addrconf_addr_solict_mult(addr, &maddr);
367 ipv6_dev_mc_dec(dev, &maddr);
368}
369
370static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
371 int len)
372{
373 int hlen = LL_RESERVED_SPACE(dev);
374 int tlen = dev->needed_tailroom;
375 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
376 struct sk_buff *skb;
377
378 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
379 if (!skb) {
380 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
381 __func__);
382 return NULL;
383 }
384
385 skb->protocol = htons(ETH_P_IPV6);
386 skb->dev = dev;
387
388 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
389 skb_reset_transport_header(skb);
390
391 /* Manually assign socket ownership as we avoid calling
392 * sock_alloc_send_pskb() to bypass wmem buffer limits
393 */
394 skb_set_owner_w(skb, sk);
395
396 return skb;
397}
398
399static void ip6_nd_hdr(struct sk_buff *skb,
400 const struct in6_addr *saddr,
401 const struct in6_addr *daddr,
402 int hop_limit, int len)
403{
404 struct ipv6hdr *hdr;
405
406 skb_push(skb, sizeof(*hdr));
407 skb_reset_network_header(skb);
408 hdr = ipv6_hdr(skb);
409
410 ip6_flow_hdr(hdr, 0, 0);
411
412 hdr->payload_len = htons(len);
413 hdr->nexthdr = IPPROTO_ICMPV6;
414 hdr->hop_limit = hop_limit;
415
416 hdr->saddr = *saddr;
417 hdr->daddr = *daddr;
418}
419
420static void ndisc_send_skb(struct sk_buff *skb,
421 const struct in6_addr *daddr,
422 const struct in6_addr *saddr)
423{
424 struct dst_entry *dst = skb_dst(skb);
425 struct net *net = dev_net(skb->dev);
426 struct sock *sk = net->ipv6.ndisc_sk;
427 struct inet6_dev *idev;
428 int err;
429 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
430 u8 type;
431
432 type = icmp6h->icmp6_type;
433
434 if (!dst) {
435 struct flowi6 fl6;
436
437 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, skb->dev->ifindex);
438 dst = icmp6_dst_alloc(skb->dev, &fl6);
439 if (IS_ERR(dst)) {
440 kfree_skb(skb);
441 return;
442 }
443
444 skb_dst_set(skb, dst);
445 }
446
447 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
448 IPPROTO_ICMPV6,
449 csum_partial(icmp6h,
450 skb->len, 0));
451
452 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
453
454 rcu_read_lock();
455 idev = __in6_dev_get(dst->dev);
456 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
457
458 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
459 dst_output);
460 if (!err) {
461 ICMP6MSGOUT_INC_STATS(net, idev, type);
462 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
463 }
464
465 rcu_read_unlock();
466}
467
468void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
469 const struct in6_addr *daddr,
470 const struct in6_addr *solicited_addr,
471 bool router, bool solicited, bool override, bool inc_opt)
472{
473 struct sk_buff *skb;
474 struct in6_addr tmpaddr;
475 struct inet6_ifaddr *ifp;
476 const struct in6_addr *src_addr;
477 struct nd_msg *msg;
478 int optlen = 0;
479
480 /* for anycast or proxy, solicited_addr != src_addr */
481 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
482 if (ifp) {
483 src_addr = solicited_addr;
484 if (ifp->flags & IFA_F_OPTIMISTIC)
485 override = false;
486 inc_opt |= ifp->idev->cnf.force_tllao;
487 in6_ifa_put(ifp);
488 } else {
489 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
490 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
491 &tmpaddr))
492 return;
493 src_addr = &tmpaddr;
494 }
495
496 if (!dev->addr_len)
497 inc_opt = 0;
498 if (inc_opt)
499 optlen += ndisc_opt_addr_space(dev);
500
501 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
502 if (!skb)
503 return;
504
505 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
506 *msg = (struct nd_msg) {
507 .icmph = {
508 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
509 .icmp6_router = router,
510 .icmp6_solicited = solicited,
511 .icmp6_override = override,
512 },
513 .target = *solicited_addr,
514 };
515
516 if (inc_opt)
517 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
518 dev->dev_addr);
519
520
521 ndisc_send_skb(skb, daddr, src_addr);
522}
523
524static void ndisc_send_unsol_na(struct net_device *dev)
525{
526 struct inet6_dev *idev;
527 struct inet6_ifaddr *ifa;
528
529 idev = in6_dev_get(dev);
530 if (!idev)
531 return;
532
533 read_lock_bh(&idev->lock);
534 list_for_each_entry(ifa, &idev->addr_list, if_list) {
535 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &ifa->addr,
536 /*router=*/ !!idev->cnf.forwarding,
537 /*solicited=*/ false, /*override=*/ true,
538 /*inc_opt=*/ true);
539 }
540 read_unlock_bh(&idev->lock);
541
542 in6_dev_put(idev);
543}
544
545void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
546 const struct in6_addr *solicit,
547 const struct in6_addr *daddr, const struct in6_addr *saddr)
548{
549 struct sk_buff *skb;
550 struct in6_addr addr_buf;
551 int inc_opt = dev->addr_len;
552 int optlen = 0;
553 struct nd_msg *msg;
554
555 if (saddr == NULL) {
556 if (ipv6_get_lladdr(dev, &addr_buf,
557 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
558 return;
559 saddr = &addr_buf;
560 }
561
562 if (ipv6_addr_any(saddr))
563 inc_opt = false;
564 if (inc_opt)
565 optlen += ndisc_opt_addr_space(dev);
566
567 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
568 if (!skb)
569 return;
570
571 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
572 *msg = (struct nd_msg) {
573 .icmph = {
574 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
575 },
576 .target = *solicit,
577 };
578
579 if (inc_opt)
580 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
581 dev->dev_addr);
582
583 ndisc_send_skb(skb, daddr, saddr);
584}
585
586void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
587 const struct in6_addr *daddr)
588{
589 struct sk_buff *skb;
590 struct rs_msg *msg;
591 int send_sllao = dev->addr_len;
592 int optlen = 0;
593
594#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
595 /*
596 * According to section 2.2 of RFC 4429, we must not
597 * send router solicitations with a sllao from
598 * optimistic addresses, but we may send the solicitation
599 * if we don't include the sllao. So here we check
600 * if our address is optimistic, and if so, we
601 * suppress the inclusion of the sllao.
602 */
603 if (send_sllao) {
604 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
605 dev, 1);
606 if (ifp) {
607 if (ifp->flags & IFA_F_OPTIMISTIC) {
608 send_sllao = 0;
609 }
610 in6_ifa_put(ifp);
611 } else {
612 send_sllao = 0;
613 }
614 }
615#endif
616 if (send_sllao)
617 optlen += ndisc_opt_addr_space(dev);
618
619 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
620 if (!skb)
621 return;
622
623 msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
624 *msg = (struct rs_msg) {
625 .icmph = {
626 .icmp6_type = NDISC_ROUTER_SOLICITATION,
627 },
628 };
629
630 if (send_sllao)
631 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
632 dev->dev_addr);
633
634 ndisc_send_skb(skb, daddr, saddr);
635}
636
637
638static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
639{
640 /*
641 * "The sender MUST return an ICMP
642 * destination unreachable"
643 */
644 dst_link_failure(skb);
645 kfree_skb(skb);
646}
647
648/* Called with locked neigh: either read or both */
649
650static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
651{
652 struct in6_addr *saddr = NULL;
653 struct in6_addr mcaddr;
654 struct net_device *dev = neigh->dev;
655 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
656 int probes = atomic_read(&neigh->probes);
657
658 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
659 saddr = &ipv6_hdr(skb)->saddr;
660
661 if ((probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES)) < 0) {
662 if (!(neigh->nud_state & NUD_VALID)) {
663 ND_PRINTK(1, dbg,
664 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
665 __func__, target);
666 }
667 ndisc_send_ns(dev, neigh, target, target, saddr);
668 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
669 neigh_app_ns(neigh);
670 } else {
671 addrconf_addr_solict_mult(target, &mcaddr);
672 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
673 }
674}
675
676static int pndisc_is_router(const void *pkey,
677 struct net_device *dev)
678{
679 struct pneigh_entry *n;
680 int ret = -1;
681
682 read_lock_bh(&nd_tbl.lock);
683 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
684 if (n)
685 ret = !!(n->flags & NTF_ROUTER);
686 read_unlock_bh(&nd_tbl.lock);
687
688 return ret;
689}
690
691static void ndisc_recv_ns(struct sk_buff *skb)
692{
693 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
694 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
695 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
696 u8 *lladdr = NULL;
697 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
698 offsetof(struct nd_msg, opt));
699 struct ndisc_options ndopts;
700 struct net_device *dev = skb->dev;
701 struct inet6_ifaddr *ifp;
702 struct inet6_dev *idev = NULL;
703 struct neighbour *neigh;
704 int dad = ipv6_addr_any(saddr);
705 bool inc;
706 int is_router = -1;
707
708 if (skb->len < sizeof(struct nd_msg)) {
709 ND_PRINTK(2, warn, "NS: packet too short\n");
710 return;
711 }
712
713 if (ipv6_addr_is_multicast(&msg->target)) {
714 ND_PRINTK(2, warn, "NS: multicast target address\n");
715 return;
716 }
717
718 /*
719 * RFC2461 7.1.1:
720 * DAD has to be destined for solicited node multicast address.
721 */
722 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
723 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
724 return;
725 }
726
727 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
728 ND_PRINTK(2, warn, "NS: invalid ND options\n");
729 return;
730 }
731
732 if (ndopts.nd_opts_src_lladdr) {
733 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
734 if (!lladdr) {
735 ND_PRINTK(2, warn,
736 "NS: invalid link-layer address length\n");
737 return;
738 }
739
740 /* RFC2461 7.1.1:
741 * If the IP source address is the unspecified address,
742 * there MUST NOT be source link-layer address option
743 * in the message.
744 */
745 if (dad) {
746 ND_PRINTK(2, warn,
747 "NS: bad DAD packet (link-layer address option)\n");
748 return;
749 }
750 }
751
752 inc = ipv6_addr_is_multicast(daddr);
753
754 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
755 if (ifp) {
756
757 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
758 if (dad) {
759 /*
760 * We are colliding with another node
761 * who is doing DAD
762 * so fail our DAD process
763 */
764 addrconf_dad_failure(ifp);
765 return;
766 } else {
767 /*
768 * This is not a dad solicitation.
769 * If we are an optimistic node,
770 * we should respond.
771 * Otherwise, we should ignore it.
772 */
773 if (!(ifp->flags & IFA_F_OPTIMISTIC))
774 goto out;
775 }
776 }
777
778 idev = ifp->idev;
779 } else {
780 struct net *net = dev_net(dev);
781
782 idev = in6_dev_get(dev);
783 if (!idev) {
784 /* XXX: count this drop? */
785 return;
786 }
787
788 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
789 (idev->cnf.forwarding &&
790 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
791 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
792 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
793 skb->pkt_type != PACKET_HOST &&
794 inc &&
795 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
796 /*
797 * for anycast or proxy,
798 * sender should delay its response
799 * by a random time between 0 and
800 * MAX_ANYCAST_DELAY_TIME seconds.
801 * (RFC2461) -- yoshfuji
802 */
803 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
804 if (n)
805 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
806 goto out;
807 }
808 } else
809 goto out;
810 }
811
812 if (is_router < 0)
813 is_router = idev->cnf.forwarding;
814
815 if (dad) {
816 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
817 !!is_router, false, (ifp != NULL), true);
818 goto out;
819 }
820
821 if (inc)
822 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
823 else
824 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
825
826 /*
827 * update / create cache entry
828 * for the source address
829 */
830 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
831 !inc || lladdr || !dev->addr_len);
832 if (neigh)
833 neigh_update(neigh, lladdr, NUD_STALE,
834 NEIGH_UPDATE_F_WEAK_OVERRIDE|
835 NEIGH_UPDATE_F_OVERRIDE);
836 if (neigh || !dev->header_ops) {
837 ndisc_send_na(dev, neigh, saddr, &msg->target,
838 !!is_router,
839 true, (ifp != NULL && inc), inc);
840 if (neigh)
841 neigh_release(neigh);
842 }
843
844out:
845 if (ifp)
846 in6_ifa_put(ifp);
847 else
848 in6_dev_put(idev);
849}
850
851static void ndisc_recv_na(struct sk_buff *skb)
852{
853 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
854 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
855 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
856 u8 *lladdr = NULL;
857 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
858 offsetof(struct nd_msg, opt));
859 struct ndisc_options ndopts;
860 struct net_device *dev = skb->dev;
861 struct inet6_ifaddr *ifp;
862 struct neighbour *neigh;
863
864 if (skb->len < sizeof(struct nd_msg)) {
865 ND_PRINTK(2, warn, "NA: packet too short\n");
866 return;
867 }
868
869 if (ipv6_addr_is_multicast(&msg->target)) {
870 ND_PRINTK(2, warn, "NA: target address is multicast\n");
871 return;
872 }
873
874 if (ipv6_addr_is_multicast(daddr) &&
875 msg->icmph.icmp6_solicited) {
876 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
877 return;
878 }
879
880 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
881 ND_PRINTK(2, warn, "NS: invalid ND option\n");
882 return;
883 }
884 if (ndopts.nd_opts_tgt_lladdr) {
885 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
886 if (!lladdr) {
887 ND_PRINTK(2, warn,
888 "NA: invalid link-layer address length\n");
889 return;
890 }
891 }
892 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
893 if (ifp) {
894 if (skb->pkt_type != PACKET_LOOPBACK
895 && (ifp->flags & IFA_F_TENTATIVE)) {
896 addrconf_dad_failure(ifp);
897 return;
898 }
899 /* What should we make now? The advertisement
900 is invalid, but ndisc specs say nothing
901 about it. It could be misconfiguration, or
902 an smart proxy agent tries to help us :-)
903
904 We should not print the error if NA has been
905 received from loopback - it is just our own
906 unsolicited advertisement.
907 */
908 if (skb->pkt_type != PACKET_LOOPBACK)
909 ND_PRINTK(1, warn,
910 "NA: someone advertises our address %pI6 on %s!\n",
911 &ifp->addr, ifp->idev->dev->name);
912 in6_ifa_put(ifp);
913 return;
914 }
915 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
916
917 if (neigh) {
918 u8 old_flags = neigh->flags;
919 struct net *net = dev_net(dev);
920
921 if (neigh->nud_state & NUD_FAILED)
922 goto out;
923
924 /*
925 * Don't update the neighbor cache entry on a proxy NA from
926 * ourselves because either the proxied node is off link or it
927 * has already sent a NA to us.
928 */
929 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
930 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
931 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
932 /* XXX: idev->cnf.proxy_ndp */
933 goto out;
934 }
935
936 neigh_update(neigh, lladdr,
937 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
938 NEIGH_UPDATE_F_WEAK_OVERRIDE|
939 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
940 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
941 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
942
943 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
944 /*
945 * Change: router to host
946 */
947 rt6_clean_tohost(dev_net(dev), saddr);
948 }
949
950out:
951 neigh_release(neigh);
952 }
953}
954
955static void ndisc_recv_rs(struct sk_buff *skb)
956{
957 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
958 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
959 struct neighbour *neigh;
960 struct inet6_dev *idev;
961 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
962 struct ndisc_options ndopts;
963 u8 *lladdr = NULL;
964
965 if (skb->len < sizeof(*rs_msg))
966 return;
967
968 idev = __in6_dev_get(skb->dev);
969 if (!idev) {
970 ND_PRINTK(1, err, "RS: can't find in6 device\n");
971 return;
972 }
973
974 /* Don't accept RS if we're not in router mode */
975 if (!idev->cnf.forwarding)
976 goto out;
977
978 /*
979 * Don't update NCE if src = ::;
980 * this implies that the source node has no ip address assigned yet.
981 */
982 if (ipv6_addr_any(saddr))
983 goto out;
984
985 /* Parse ND options */
986 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
987 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
988 goto out;
989 }
990
991 if (ndopts.nd_opts_src_lladdr) {
992 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
993 skb->dev);
994 if (!lladdr)
995 goto out;
996 }
997
998 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
999 if (neigh) {
1000 neigh_update(neigh, lladdr, NUD_STALE,
1001 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1002 NEIGH_UPDATE_F_OVERRIDE|
1003 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1004 neigh_release(neigh);
1005 }
1006out:
1007 return;
1008}
1009
1010static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1011{
1012 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1013 struct sk_buff *skb;
1014 struct nlmsghdr *nlh;
1015 struct nduseroptmsg *ndmsg;
1016 struct net *net = dev_net(ra->dev);
1017 int err;
1018 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1019 + (opt->nd_opt_len << 3));
1020 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1021
1022 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1023 if (skb == NULL) {
1024 err = -ENOBUFS;
1025 goto errout;
1026 }
1027
1028 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1029 if (nlh == NULL) {
1030 goto nla_put_failure;
1031 }
1032
1033 ndmsg = nlmsg_data(nlh);
1034 ndmsg->nduseropt_family = AF_INET6;
1035 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1036 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1037 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1038 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1039
1040 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1041
1042 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1043 &ipv6_hdr(ra)->saddr))
1044 goto nla_put_failure;
1045 nlmsg_end(skb, nlh);
1046
1047 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1048 return;
1049
1050nla_put_failure:
1051 nlmsg_free(skb);
1052 err = -EMSGSIZE;
1053errout:
1054 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1055}
1056
1057static void ndisc_router_discovery(struct sk_buff *skb)
1058{
1059 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1060 struct neighbour *neigh = NULL;
1061 struct inet6_dev *in6_dev;
1062 struct rt6_info *rt = NULL;
1063 int lifetime;
1064 struct ndisc_options ndopts;
1065 int optlen;
1066 unsigned int pref = 0;
1067
1068 __u8 * opt = (__u8 *)(ra_msg + 1);
1069
1070 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1071 sizeof(struct ra_msg);
1072
1073 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1074 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1075 return;
1076 }
1077 if (optlen < 0) {
1078 ND_PRINTK(2, warn, "RA: packet too short\n");
1079 return;
1080 }
1081
1082#ifdef CONFIG_IPV6_NDISC_NODETYPE
1083 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1084 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1085 return;
1086 }
1087#endif
1088
1089 /*
1090 * set the RA_RECV flag in the interface
1091 */
1092
1093 in6_dev = __in6_dev_get(skb->dev);
1094 if (in6_dev == NULL) {
1095 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1096 skb->dev->name);
1097 return;
1098 }
1099
1100 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1101 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1102 return;
1103 }
1104
1105 if (!ipv6_accept_ra(in6_dev))
1106 goto skip_linkparms;
1107
1108#ifdef CONFIG_IPV6_NDISC_NODETYPE
1109 /* skip link-specific parameters from interior routers */
1110 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1111 goto skip_linkparms;
1112#endif
1113
1114 if (in6_dev->if_flags & IF_RS_SENT) {
1115 /*
1116 * flag that an RA was received after an RS was sent
1117 * out on this interface.
1118 */
1119 in6_dev->if_flags |= IF_RA_RCVD;
1120 }
1121
1122 /*
1123 * Remember the managed/otherconf flags from most recently
1124 * received RA message (RFC 2462) -- yoshfuji
1125 */
1126 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1127 IF_RA_OTHERCONF)) |
1128 (ra_msg->icmph.icmp6_addrconf_managed ?
1129 IF_RA_MANAGED : 0) |
1130 (ra_msg->icmph.icmp6_addrconf_other ?
1131 IF_RA_OTHERCONF : 0);
1132
1133 if (!in6_dev->cnf.accept_ra_defrtr)
1134 goto skip_defrtr;
1135
1136 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1137 goto skip_defrtr;
1138
1139 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1140
1141#ifdef CONFIG_IPV6_ROUTER_PREF
1142 pref = ra_msg->icmph.icmp6_router_pref;
1143 /* 10b is handled as if it were 00b (medium) */
1144 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1145 !in6_dev->cnf.accept_ra_rtr_pref)
1146 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1147#endif
1148
1149 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1150
1151 if (rt) {
1152 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1153 if (!neigh) {
1154 ND_PRINTK(0, err,
1155 "RA: %s got default router without neighbour\n",
1156 __func__);
1157 ip6_rt_put(rt);
1158 return;
1159 }
1160 }
1161 if (rt && lifetime == 0) {
1162 ip6_del_rt(rt);
1163 rt = NULL;
1164 }
1165
1166 if (rt == NULL && lifetime) {
1167 ND_PRINTK(3, dbg, "RA: adding default router\n");
1168
1169 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1170 if (rt == NULL) {
1171 ND_PRINTK(0, err,
1172 "RA: %s failed to add default route\n",
1173 __func__);
1174 return;
1175 }
1176
1177 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1178 if (neigh == NULL) {
1179 ND_PRINTK(0, err,
1180 "RA: %s got default router without neighbour\n",
1181 __func__);
1182 ip6_rt_put(rt);
1183 return;
1184 }
1185 neigh->flags |= NTF_ROUTER;
1186 } else if (rt) {
1187 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1188 }
1189
1190 if (rt)
1191 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1192 if (ra_msg->icmph.icmp6_hop_limit) {
1193 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1194 if (rt)
1195 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1196 ra_msg->icmph.icmp6_hop_limit);
1197 }
1198
1199skip_defrtr:
1200
1201 /*
1202 * Update Reachable Time and Retrans Timer
1203 */
1204
1205 if (in6_dev->nd_parms) {
1206 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1207
1208 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1209 rtime = (rtime*HZ)/1000;
1210 if (rtime < HZ/10)
1211 rtime = HZ/10;
1212 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1213 in6_dev->tstamp = jiffies;
1214 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1215 }
1216
1217 rtime = ntohl(ra_msg->reachable_time);
1218 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1219 rtime = (rtime*HZ)/1000;
1220
1221 if (rtime < HZ/10)
1222 rtime = HZ/10;
1223
1224 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1225 NEIGH_VAR_SET(in6_dev->nd_parms,
1226 BASE_REACHABLE_TIME, rtime);
1227 NEIGH_VAR_SET(in6_dev->nd_parms,
1228 GC_STALETIME, 3 * rtime);
1229 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1230 in6_dev->tstamp = jiffies;
1231 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1232 }
1233 }
1234 }
1235
1236skip_linkparms:
1237
1238 /*
1239 * Process options.
1240 */
1241
1242 if (!neigh)
1243 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1244 skb->dev, 1);
1245 if (neigh) {
1246 u8 *lladdr = NULL;
1247 if (ndopts.nd_opts_src_lladdr) {
1248 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1249 skb->dev);
1250 if (!lladdr) {
1251 ND_PRINTK(2, warn,
1252 "RA: invalid link-layer address length\n");
1253 goto out;
1254 }
1255 }
1256 neigh_update(neigh, lladdr, NUD_STALE,
1257 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1258 NEIGH_UPDATE_F_OVERRIDE|
1259 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1260 NEIGH_UPDATE_F_ISROUTER);
1261 }
1262
1263 if (!ipv6_accept_ra(in6_dev))
1264 goto out;
1265
1266#ifdef CONFIG_IPV6_ROUTE_INFO
1267 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1268 goto skip_routeinfo;
1269
1270 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1271 struct nd_opt_hdr *p;
1272 for (p = ndopts.nd_opts_ri;
1273 p;
1274 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1275 struct route_info *ri = (struct route_info *)p;
1276#ifdef CONFIG_IPV6_NDISC_NODETYPE
1277 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1278 ri->prefix_len == 0)
1279 continue;
1280#endif
1281 if (ri->prefix_len == 0 &&
1282 !in6_dev->cnf.accept_ra_defrtr)
1283 continue;
1284 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1285 continue;
1286 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1287 &ipv6_hdr(skb)->saddr);
1288 }
1289 }
1290
1291skip_routeinfo:
1292#endif
1293
1294#ifdef CONFIG_IPV6_NDISC_NODETYPE
1295 /* skip link-specific ndopts from interior routers */
1296 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1297 goto out;
1298#endif
1299
1300 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1301 struct nd_opt_hdr *p;
1302 for (p = ndopts.nd_opts_pi;
1303 p;
1304 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1305 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1306 (p->nd_opt_len) << 3,
1307 ndopts.nd_opts_src_lladdr != NULL);
1308 }
1309 }
1310
1311 if (ndopts.nd_opts_mtu) {
1312 __be32 n;
1313 u32 mtu;
1314
1315 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1316 mtu = ntohl(n);
1317
1318 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1319 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1320 } else if (in6_dev->cnf.mtu6 != mtu) {
1321 in6_dev->cnf.mtu6 = mtu;
1322
1323 if (rt)
1324 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1325
1326 rt6_mtu_change(skb->dev, mtu);
1327 }
1328 }
1329
1330 if (ndopts.nd_useropts) {
1331 struct nd_opt_hdr *p;
1332 for (p = ndopts.nd_useropts;
1333 p;
1334 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1335 ndisc_ra_useropt(skb, p);
1336 }
1337 }
1338
1339 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1340 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1341 }
1342out:
1343 ip6_rt_put(rt);
1344 if (neigh)
1345 neigh_release(neigh);
1346}
1347
1348static void ndisc_redirect_rcv(struct sk_buff *skb)
1349{
1350 u8 *hdr;
1351 struct ndisc_options ndopts;
1352 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1353 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1354 offsetof(struct rd_msg, opt));
1355
1356#ifdef CONFIG_IPV6_NDISC_NODETYPE
1357 switch (skb->ndisc_nodetype) {
1358 case NDISC_NODETYPE_HOST:
1359 case NDISC_NODETYPE_NODEFAULT:
1360 ND_PRINTK(2, warn,
1361 "Redirect: from host or unauthorized router\n");
1362 return;
1363 }
1364#endif
1365
1366 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1367 ND_PRINTK(2, warn,
1368 "Redirect: source address is not link-local\n");
1369 return;
1370 }
1371
1372 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
1373 return;
1374
1375 if (!ndopts.nd_opts_rh) {
1376 ip6_redirect_no_header(skb, dev_net(skb->dev),
1377 skb->dev->ifindex, 0);
1378 return;
1379 }
1380
1381 hdr = (u8 *)ndopts.nd_opts_rh;
1382 hdr += 8;
1383 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1384 return;
1385
1386 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1387}
1388
1389static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1390 struct sk_buff *orig_skb,
1391 int rd_len)
1392{
1393 u8 *opt = skb_put(skb, rd_len);
1394
1395 memset(opt, 0, 8);
1396 *(opt++) = ND_OPT_REDIRECT_HDR;
1397 *(opt++) = (rd_len >> 3);
1398 opt += 6;
1399
1400 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
1401}
1402
1403void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1404{
1405 struct net_device *dev = skb->dev;
1406 struct net *net = dev_net(dev);
1407 struct sock *sk = net->ipv6.ndisc_sk;
1408 int optlen = 0;
1409 struct inet_peer *peer;
1410 struct sk_buff *buff;
1411 struct rd_msg *msg;
1412 struct in6_addr saddr_buf;
1413 struct rt6_info *rt;
1414 struct dst_entry *dst;
1415 struct flowi6 fl6;
1416 int rd_len;
1417 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1418 bool ret;
1419
1420 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1421 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1422 dev->name);
1423 return;
1424 }
1425
1426 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1427 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1428 ND_PRINTK(2, warn,
1429 "Redirect: target address is not link-local unicast\n");
1430 return;
1431 }
1432
1433 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1434 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1435
1436 dst = ip6_route_output(net, NULL, &fl6);
1437 if (dst->error) {
1438 dst_release(dst);
1439 return;
1440 }
1441 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1442 if (IS_ERR(dst))
1443 return;
1444
1445 rt = (struct rt6_info *) dst;
1446
1447 if (rt->rt6i_flags & RTF_GATEWAY) {
1448 ND_PRINTK(2, warn,
1449 "Redirect: destination is not a neighbour\n");
1450 goto release;
1451 }
1452 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
1453 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1454 if (peer)
1455 inet_putpeer(peer);
1456 if (!ret)
1457 goto release;
1458
1459 if (dev->addr_len) {
1460 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1461 if (!neigh) {
1462 ND_PRINTK(2, warn,
1463 "Redirect: no neigh for target address\n");
1464 goto release;
1465 }
1466
1467 read_lock_bh(&neigh->lock);
1468 if (neigh->nud_state & NUD_VALID) {
1469 memcpy(ha_buf, neigh->ha, dev->addr_len);
1470 read_unlock_bh(&neigh->lock);
1471 ha = ha_buf;
1472 optlen += ndisc_opt_addr_space(dev);
1473 } else
1474 read_unlock_bh(&neigh->lock);
1475
1476 neigh_release(neigh);
1477 }
1478
1479 rd_len = min_t(unsigned int,
1480 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1481 skb->len + 8);
1482 rd_len &= ~0x7;
1483 optlen += rd_len;
1484
1485 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1486 if (!buff)
1487 goto release;
1488
1489 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1490 *msg = (struct rd_msg) {
1491 .icmph = {
1492 .icmp6_type = NDISC_REDIRECT,
1493 },
1494 .target = *target,
1495 .dest = ipv6_hdr(skb)->daddr,
1496 };
1497
1498 /*
1499 * include target_address option
1500 */
1501
1502 if (ha)
1503 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
1504
1505 /*
1506 * build redirect option and copy skb over to the new packet.
1507 */
1508
1509 if (rd_len)
1510 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1511
1512 skb_dst_set(buff, dst);
1513 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1514 return;
1515
1516release:
1517 dst_release(dst);
1518}
1519
1520static void pndisc_redo(struct sk_buff *skb)
1521{
1522 ndisc_recv_ns(skb);
1523 kfree_skb(skb);
1524}
1525
1526static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1527{
1528 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1529
1530 if (!idev)
1531 return true;
1532 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1533 idev->cnf.suppress_frag_ndisc) {
1534 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1535 return true;
1536 }
1537 return false;
1538}
1539
1540int ndisc_rcv(struct sk_buff *skb)
1541{
1542 struct nd_msg *msg;
1543
1544 if (ndisc_suppress_frag_ndisc(skb))
1545 return 0;
1546
1547 if (skb_linearize(skb))
1548 return 0;
1549
1550 msg = (struct nd_msg *)skb_transport_header(skb);
1551
1552 __skb_push(skb, skb->data - skb_transport_header(skb));
1553
1554 if (ipv6_hdr(skb)->hop_limit != 255) {
1555 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1556 ipv6_hdr(skb)->hop_limit);
1557 return 0;
1558 }
1559
1560 if (msg->icmph.icmp6_code != 0) {
1561 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1562 msg->icmph.icmp6_code);
1563 return 0;
1564 }
1565
1566 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1567
1568 switch (msg->icmph.icmp6_type) {
1569 case NDISC_NEIGHBOUR_SOLICITATION:
1570 ndisc_recv_ns(skb);
1571 break;
1572
1573 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1574 ndisc_recv_na(skb);
1575 break;
1576
1577 case NDISC_ROUTER_SOLICITATION:
1578 ndisc_recv_rs(skb);
1579 break;
1580
1581 case NDISC_ROUTER_ADVERTISEMENT:
1582 ndisc_router_discovery(skb);
1583 break;
1584
1585 case NDISC_REDIRECT:
1586 ndisc_redirect_rcv(skb);
1587 break;
1588 }
1589
1590 return 0;
1591}
1592
1593static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1594{
1595 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1596 struct net *net = dev_net(dev);
1597 struct inet6_dev *idev;
1598
1599 switch (event) {
1600 case NETDEV_CHANGEADDR:
1601 neigh_changeaddr(&nd_tbl, dev);
1602 fib6_run_gc(0, net, false);
1603 idev = in6_dev_get(dev);
1604 if (!idev)
1605 break;
1606 if (idev->cnf.ndisc_notify)
1607 ndisc_send_unsol_na(dev);
1608 in6_dev_put(idev);
1609 break;
1610 case NETDEV_DOWN:
1611 neigh_ifdown(&nd_tbl, dev);
1612 fib6_run_gc(0, net, false);
1613 break;
1614 case NETDEV_NOTIFY_PEERS:
1615 ndisc_send_unsol_na(dev);
1616 break;
1617 default:
1618 break;
1619 }
1620
1621 return NOTIFY_DONE;
1622}
1623
1624static struct notifier_block ndisc_netdev_notifier = {
1625 .notifier_call = ndisc_netdev_event,
1626};
1627
1628#ifdef CONFIG_SYSCTL
1629static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1630 const char *func, const char *dev_name)
1631{
1632 static char warncomm[TASK_COMM_LEN];
1633 static int warned;
1634 if (strcmp(warncomm, current->comm) && warned < 5) {
1635 strcpy(warncomm, current->comm);
1636 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1637 warncomm, func,
1638 dev_name, ctl->procname,
1639 dev_name, ctl->procname);
1640 warned++;
1641 }
1642}
1643
1644int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1645{
1646 struct net_device *dev = ctl->extra1;
1647 struct inet6_dev *idev;
1648 int ret;
1649
1650 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1651 (strcmp(ctl->procname, "base_reachable_time") == 0))
1652 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1653
1654 if (strcmp(ctl->procname, "retrans_time") == 0)
1655 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1656
1657 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1658 ret = neigh_proc_dointvec_jiffies(ctl, write,
1659 buffer, lenp, ppos);
1660
1661 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1662 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1663 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1664 buffer, lenp, ppos);
1665 else
1666 ret = -1;
1667
1668 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1669 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1670 idev->nd_parms->reachable_time =
1671 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1672 idev->tstamp = jiffies;
1673 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1674 in6_dev_put(idev);
1675 }
1676 return ret;
1677}
1678
1679
1680#endif
1681
1682static int __net_init ndisc_net_init(struct net *net)
1683{
1684 struct ipv6_pinfo *np;
1685 struct sock *sk;
1686 int err;
1687
1688 err = inet_ctl_sock_create(&sk, PF_INET6,
1689 SOCK_RAW, IPPROTO_ICMPV6, net);
1690 if (err < 0) {
1691 ND_PRINTK(0, err,
1692 "NDISC: Failed to initialize the control socket (err %d)\n",
1693 err);
1694 return err;
1695 }
1696
1697 net->ipv6.ndisc_sk = sk;
1698
1699 np = inet6_sk(sk);
1700 np->hop_limit = 255;
1701 /* Do not loopback ndisc messages */
1702 np->mc_loop = 0;
1703
1704 return 0;
1705}
1706
1707static void __net_exit ndisc_net_exit(struct net *net)
1708{
1709 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1710}
1711
1712static struct pernet_operations ndisc_net_ops = {
1713 .init = ndisc_net_init,
1714 .exit = ndisc_net_exit,
1715};
1716
1717int __init ndisc_init(void)
1718{
1719 int err;
1720
1721 err = register_pernet_subsys(&ndisc_net_ops);
1722 if (err)
1723 return err;
1724 /*
1725 * Initialize the neighbour table
1726 */
1727 neigh_table_init(&nd_tbl);
1728
1729#ifdef CONFIG_SYSCTL
1730 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1731 &ndisc_ifinfo_sysctl_change);
1732 if (err)
1733 goto out_unregister_pernet;
1734out:
1735#endif
1736 return err;
1737
1738#ifdef CONFIG_SYSCTL
1739out_unregister_pernet:
1740 unregister_pernet_subsys(&ndisc_net_ops);
1741 goto out;
1742#endif
1743}
1744
1745int __init ndisc_late_init(void)
1746{
1747 return register_netdevice_notifier(&ndisc_netdev_notifier);
1748}
1749
1750void ndisc_late_cleanup(void)
1751{
1752 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1753}
1754
1755void ndisc_cleanup(void)
1756{
1757#ifdef CONFIG_SYSCTL
1758 neigh_sysctl_unregister(&nd_tbl.parms);
1759#endif
1760 neigh_table_clear(&nd_tbl);
1761 unregister_pernet_subsys(&ndisc_net_ops);
1762}
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_ether.h>
50#include <linux/if_arp.h>
51#include <linux/ipv6.h>
52#include <linux/icmpv6.h>
53#include <linux/jhash.h>
54
55#include <net/sock.h>
56#include <net/snmp.h>
57
58#include <net/ipv6.h>
59#include <net/protocol.h>
60#include <net/ndisc.h>
61#include <net/ip6_route.h>
62#include <net/addrconf.h>
63#include <net/icmp.h>
64
65#include <net/netlink.h>
66#include <linux/rtnetlink.h>
67
68#include <net/flow.h>
69#include <net/ip6_checksum.h>
70#include <net/inet_common.h>
71#include <linux/proc_fs.h>
72
73#include <linux/netfilter.h>
74#include <linux/netfilter_ipv6.h>
75
76static u32 ndisc_hash(const void *pkey,
77 const struct net_device *dev,
78 __u32 *hash_rnd);
79static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
80static int ndisc_constructor(struct neighbour *neigh);
81static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
82static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
83static int pndisc_constructor(struct pneigh_entry *n);
84static void pndisc_destructor(struct pneigh_entry *n);
85static void pndisc_redo(struct sk_buff *skb);
86
87static const struct neigh_ops ndisc_generic_ops = {
88 .family = AF_INET6,
89 .solicit = ndisc_solicit,
90 .error_report = ndisc_error_report,
91 .output = neigh_resolve_output,
92 .connected_output = neigh_connected_output,
93};
94
95static const struct neigh_ops ndisc_hh_ops = {
96 .family = AF_INET6,
97 .solicit = ndisc_solicit,
98 .error_report = ndisc_error_report,
99 .output = neigh_resolve_output,
100 .connected_output = neigh_resolve_output,
101};
102
103
104static const struct neigh_ops ndisc_direct_ops = {
105 .family = AF_INET6,
106 .output = neigh_direct_output,
107 .connected_output = neigh_direct_output,
108};
109
110struct neigh_table nd_tbl = {
111 .family = AF_INET6,
112 .key_len = sizeof(struct in6_addr),
113 .protocol = cpu_to_be16(ETH_P_IPV6),
114 .hash = ndisc_hash,
115 .key_eq = ndisc_key_eq,
116 .constructor = ndisc_constructor,
117 .pconstructor = pndisc_constructor,
118 .pdestructor = pndisc_destructor,
119 .proxy_redo = pndisc_redo,
120 .id = "ndisc_cache",
121 .parms = {
122 .tbl = &nd_tbl,
123 .reachable_time = ND_REACHABLE_TIME,
124 .data = {
125 [NEIGH_VAR_MCAST_PROBES] = 3,
126 [NEIGH_VAR_UCAST_PROBES] = 3,
127 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
128 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
129 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
130 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
131 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
132 [NEIGH_VAR_PROXY_QLEN] = 64,
133 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
134 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
135 },
136 },
137 .gc_interval = 30 * HZ,
138 .gc_thresh1 = 128,
139 .gc_thresh2 = 512,
140 .gc_thresh3 = 1024,
141};
142EXPORT_SYMBOL_GPL(nd_tbl);
143
144void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
145 int data_len, int pad)
146{
147 int space = __ndisc_opt_addr_space(data_len, pad);
148 u8 *opt = skb_put(skb, space);
149
150 opt[0] = type;
151 opt[1] = space>>3;
152
153 memset(opt + 2, 0, pad);
154 opt += pad;
155 space -= pad;
156
157 memcpy(opt+2, data, data_len);
158 data_len += 2;
159 opt += data_len;
160 space -= data_len;
161 if (space > 0)
162 memset(opt, 0, space);
163}
164EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
165
166static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
167 void *data, u8 icmp6_type)
168{
169 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
170 ndisc_addr_option_pad(skb->dev->type));
171 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
172}
173
174static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
175 void *ha,
176 const u8 *ops_data)
177{
178 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
179 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
180}
181
182static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
183 struct nd_opt_hdr *end)
184{
185 int type;
186 if (!cur || !end || cur >= end)
187 return NULL;
188 type = cur->nd_opt_type;
189 do {
190 cur = ((void *)cur) + (cur->nd_opt_len << 3);
191 } while (cur < end && cur->nd_opt_type != type);
192 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
193}
194
195static inline int ndisc_is_useropt(const struct net_device *dev,
196 struct nd_opt_hdr *opt)
197{
198 return opt->nd_opt_type == ND_OPT_RDNSS ||
199 opt->nd_opt_type == ND_OPT_DNSSL ||
200 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
201}
202
203static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
204 struct nd_opt_hdr *cur,
205 struct nd_opt_hdr *end)
206{
207 if (!cur || !end || cur >= end)
208 return NULL;
209 do {
210 cur = ((void *)cur) + (cur->nd_opt_len << 3);
211 } while (cur < end && !ndisc_is_useropt(dev, cur));
212 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
213}
214
215struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
216 u8 *opt, int opt_len,
217 struct ndisc_options *ndopts)
218{
219 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
220
221 if (!nd_opt || opt_len < 0 || !ndopts)
222 return NULL;
223 memset(ndopts, 0, sizeof(*ndopts));
224 while (opt_len) {
225 int l;
226 if (opt_len < sizeof(struct nd_opt_hdr))
227 return NULL;
228 l = nd_opt->nd_opt_len << 3;
229 if (opt_len < l || l == 0)
230 return NULL;
231 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
232 goto next_opt;
233 switch (nd_opt->nd_opt_type) {
234 case ND_OPT_SOURCE_LL_ADDR:
235 case ND_OPT_TARGET_LL_ADDR:
236 case ND_OPT_MTU:
237 case ND_OPT_NONCE:
238 case ND_OPT_REDIRECT_HDR:
239 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
240 ND_PRINTK(2, warn,
241 "%s: duplicated ND6 option found: type=%d\n",
242 __func__, nd_opt->nd_opt_type);
243 } else {
244 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
245 }
246 break;
247 case ND_OPT_PREFIX_INFO:
248 ndopts->nd_opts_pi_end = nd_opt;
249 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
250 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
251 break;
252#ifdef CONFIG_IPV6_ROUTE_INFO
253 case ND_OPT_ROUTE_INFO:
254 ndopts->nd_opts_ri_end = nd_opt;
255 if (!ndopts->nd_opts_ri)
256 ndopts->nd_opts_ri = nd_opt;
257 break;
258#endif
259 default:
260 if (ndisc_is_useropt(dev, nd_opt)) {
261 ndopts->nd_useropts_end = nd_opt;
262 if (!ndopts->nd_useropts)
263 ndopts->nd_useropts = nd_opt;
264 } else {
265 /*
266 * Unknown options must be silently ignored,
267 * to accommodate future extension to the
268 * protocol.
269 */
270 ND_PRINTK(2, notice,
271 "%s: ignored unsupported option; type=%d, len=%d\n",
272 __func__,
273 nd_opt->nd_opt_type,
274 nd_opt->nd_opt_len);
275 }
276 }
277next_opt:
278 opt_len -= l;
279 nd_opt = ((void *)nd_opt) + l;
280 }
281 return ndopts;
282}
283
284int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
285{
286 switch (dev->type) {
287 case ARPHRD_ETHER:
288 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
289 case ARPHRD_FDDI:
290 ipv6_eth_mc_map(addr, buf);
291 return 0;
292 case ARPHRD_ARCNET:
293 ipv6_arcnet_mc_map(addr, buf);
294 return 0;
295 case ARPHRD_INFINIBAND:
296 ipv6_ib_mc_map(addr, dev->broadcast, buf);
297 return 0;
298 case ARPHRD_IPGRE:
299 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
300 default:
301 if (dir) {
302 memcpy(buf, dev->broadcast, dev->addr_len);
303 return 0;
304 }
305 }
306 return -EINVAL;
307}
308EXPORT_SYMBOL(ndisc_mc_map);
309
310static u32 ndisc_hash(const void *pkey,
311 const struct net_device *dev,
312 __u32 *hash_rnd)
313{
314 return ndisc_hashfn(pkey, dev, hash_rnd);
315}
316
317static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
318{
319 return neigh_key_eq128(n, pkey);
320}
321
322static int ndisc_constructor(struct neighbour *neigh)
323{
324 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
325 struct net_device *dev = neigh->dev;
326 struct inet6_dev *in6_dev;
327 struct neigh_parms *parms;
328 bool is_multicast = ipv6_addr_is_multicast(addr);
329
330 in6_dev = in6_dev_get(dev);
331 if (!in6_dev) {
332 return -EINVAL;
333 }
334
335 parms = in6_dev->nd_parms;
336 __neigh_parms_put(neigh->parms);
337 neigh->parms = neigh_parms_clone(parms);
338
339 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
340 if (!dev->header_ops) {
341 neigh->nud_state = NUD_NOARP;
342 neigh->ops = &ndisc_direct_ops;
343 neigh->output = neigh_direct_output;
344 } else {
345 if (is_multicast) {
346 neigh->nud_state = NUD_NOARP;
347 ndisc_mc_map(addr, neigh->ha, dev, 1);
348 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
349 neigh->nud_state = NUD_NOARP;
350 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
351 if (dev->flags&IFF_LOOPBACK)
352 neigh->type = RTN_LOCAL;
353 } else if (dev->flags&IFF_POINTOPOINT) {
354 neigh->nud_state = NUD_NOARP;
355 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
356 }
357 if (dev->header_ops->cache)
358 neigh->ops = &ndisc_hh_ops;
359 else
360 neigh->ops = &ndisc_generic_ops;
361 if (neigh->nud_state&NUD_VALID)
362 neigh->output = neigh->ops->connected_output;
363 else
364 neigh->output = neigh->ops->output;
365 }
366 in6_dev_put(in6_dev);
367 return 0;
368}
369
370static int pndisc_constructor(struct pneigh_entry *n)
371{
372 struct in6_addr *addr = (struct in6_addr *)&n->key;
373 struct in6_addr maddr;
374 struct net_device *dev = n->dev;
375
376 if (!dev || !__in6_dev_get(dev))
377 return -EINVAL;
378 addrconf_addr_solict_mult(addr, &maddr);
379 ipv6_dev_mc_inc(dev, &maddr);
380 return 0;
381}
382
383static void pndisc_destructor(struct pneigh_entry *n)
384{
385 struct in6_addr *addr = (struct in6_addr *)&n->key;
386 struct in6_addr maddr;
387 struct net_device *dev = n->dev;
388
389 if (!dev || !__in6_dev_get(dev))
390 return;
391 addrconf_addr_solict_mult(addr, &maddr);
392 ipv6_dev_mc_dec(dev, &maddr);
393}
394
395static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
396 int len)
397{
398 int hlen = LL_RESERVED_SPACE(dev);
399 int tlen = dev->needed_tailroom;
400 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
401 struct sk_buff *skb;
402
403 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
404 if (!skb) {
405 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
406 __func__);
407 return NULL;
408 }
409
410 skb->protocol = htons(ETH_P_IPV6);
411 skb->dev = dev;
412
413 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
414 skb_reset_transport_header(skb);
415
416 /* Manually assign socket ownership as we avoid calling
417 * sock_alloc_send_pskb() to bypass wmem buffer limits
418 */
419 skb_set_owner_w(skb, sk);
420
421 return skb;
422}
423
424static void ip6_nd_hdr(struct sk_buff *skb,
425 const struct in6_addr *saddr,
426 const struct in6_addr *daddr,
427 int hop_limit, int len)
428{
429 struct ipv6hdr *hdr;
430 struct inet6_dev *idev;
431 unsigned tclass;
432
433 rcu_read_lock();
434 idev = __in6_dev_get(skb->dev);
435 tclass = idev ? idev->cnf.ndisc_tclass : 0;
436 rcu_read_unlock();
437
438 skb_push(skb, sizeof(*hdr));
439 skb_reset_network_header(skb);
440 hdr = ipv6_hdr(skb);
441
442 ip6_flow_hdr(hdr, tclass, 0);
443
444 hdr->payload_len = htons(len);
445 hdr->nexthdr = IPPROTO_ICMPV6;
446 hdr->hop_limit = hop_limit;
447
448 hdr->saddr = *saddr;
449 hdr->daddr = *daddr;
450}
451
452static void ndisc_send_skb(struct sk_buff *skb,
453 const struct in6_addr *daddr,
454 const struct in6_addr *saddr)
455{
456 struct dst_entry *dst = skb_dst(skb);
457 struct net *net = dev_net(skb->dev);
458 struct sock *sk = net->ipv6.ndisc_sk;
459 struct inet6_dev *idev;
460 int err;
461 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
462 u8 type;
463
464 type = icmp6h->icmp6_type;
465
466 if (!dst) {
467 struct flowi6 fl6;
468 int oif = skb->dev->ifindex;
469
470 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
471 dst = icmp6_dst_alloc(skb->dev, &fl6);
472 if (IS_ERR(dst)) {
473 kfree_skb(skb);
474 return;
475 }
476
477 skb_dst_set(skb, dst);
478 }
479
480 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
481 IPPROTO_ICMPV6,
482 csum_partial(icmp6h,
483 skb->len, 0));
484
485 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
486
487 rcu_read_lock();
488 idev = __in6_dev_get(dst->dev);
489 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
490
491 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
492 net, sk, skb, NULL, dst->dev,
493 dst_output);
494 if (!err) {
495 ICMP6MSGOUT_INC_STATS(net, idev, type);
496 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
497 }
498
499 rcu_read_unlock();
500}
501
502void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
503 const struct in6_addr *solicited_addr,
504 bool router, bool solicited, bool override, bool inc_opt)
505{
506 struct sk_buff *skb;
507 struct in6_addr tmpaddr;
508 struct inet6_ifaddr *ifp;
509 const struct in6_addr *src_addr;
510 struct nd_msg *msg;
511 int optlen = 0;
512
513 /* for anycast or proxy, solicited_addr != src_addr */
514 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
515 if (ifp) {
516 src_addr = solicited_addr;
517 if (ifp->flags & IFA_F_OPTIMISTIC)
518 override = false;
519 inc_opt |= ifp->idev->cnf.force_tllao;
520 in6_ifa_put(ifp);
521 } else {
522 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
523 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
524 &tmpaddr))
525 return;
526 src_addr = &tmpaddr;
527 }
528
529 if (!dev->addr_len)
530 inc_opt = false;
531 if (inc_opt)
532 optlen += ndisc_opt_addr_space(dev,
533 NDISC_NEIGHBOUR_ADVERTISEMENT);
534
535 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
536 if (!skb)
537 return;
538
539 msg = skb_put(skb, sizeof(*msg));
540 *msg = (struct nd_msg) {
541 .icmph = {
542 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
543 .icmp6_router = router,
544 .icmp6_solicited = solicited,
545 .icmp6_override = override,
546 },
547 .target = *solicited_addr,
548 };
549
550 if (inc_opt)
551 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
552 dev->dev_addr,
553 NDISC_NEIGHBOUR_ADVERTISEMENT);
554
555 ndisc_send_skb(skb, daddr, src_addr);
556}
557
558static void ndisc_send_unsol_na(struct net_device *dev)
559{
560 struct inet6_dev *idev;
561 struct inet6_ifaddr *ifa;
562
563 idev = in6_dev_get(dev);
564 if (!idev)
565 return;
566
567 read_lock_bh(&idev->lock);
568 list_for_each_entry(ifa, &idev->addr_list, if_list) {
569 /* skip tentative addresses until dad completes */
570 if (ifa->flags & IFA_F_TENTATIVE &&
571 !(ifa->flags & IFA_F_OPTIMISTIC))
572 continue;
573
574 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
575 /*router=*/ !!idev->cnf.forwarding,
576 /*solicited=*/ false, /*override=*/ true,
577 /*inc_opt=*/ true);
578 }
579 read_unlock_bh(&idev->lock);
580
581 in6_dev_put(idev);
582}
583
584void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
585 const struct in6_addr *daddr, const struct in6_addr *saddr,
586 u64 nonce)
587{
588 struct sk_buff *skb;
589 struct in6_addr addr_buf;
590 int inc_opt = dev->addr_len;
591 int optlen = 0;
592 struct nd_msg *msg;
593
594 if (!saddr) {
595 if (ipv6_get_lladdr(dev, &addr_buf,
596 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
597 return;
598 saddr = &addr_buf;
599 }
600
601 if (ipv6_addr_any(saddr))
602 inc_opt = false;
603 if (inc_opt)
604 optlen += ndisc_opt_addr_space(dev,
605 NDISC_NEIGHBOUR_SOLICITATION);
606 if (nonce != 0)
607 optlen += 8;
608
609 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
610 if (!skb)
611 return;
612
613 msg = skb_put(skb, sizeof(*msg));
614 *msg = (struct nd_msg) {
615 .icmph = {
616 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
617 },
618 .target = *solicit,
619 };
620
621 if (inc_opt)
622 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
623 dev->dev_addr,
624 NDISC_NEIGHBOUR_SOLICITATION);
625 if (nonce != 0) {
626 u8 *opt = skb_put(skb, 8);
627
628 opt[0] = ND_OPT_NONCE;
629 opt[1] = 8 >> 3;
630 memcpy(opt + 2, &nonce, 6);
631 }
632
633 ndisc_send_skb(skb, daddr, saddr);
634}
635
636void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
637 const struct in6_addr *daddr)
638{
639 struct sk_buff *skb;
640 struct rs_msg *msg;
641 int send_sllao = dev->addr_len;
642 int optlen = 0;
643
644#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
645 /*
646 * According to section 2.2 of RFC 4429, we must not
647 * send router solicitations with a sllao from
648 * optimistic addresses, but we may send the solicitation
649 * if we don't include the sllao. So here we check
650 * if our address is optimistic, and if so, we
651 * suppress the inclusion of the sllao.
652 */
653 if (send_sllao) {
654 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
655 dev, 1);
656 if (ifp) {
657 if (ifp->flags & IFA_F_OPTIMISTIC) {
658 send_sllao = 0;
659 }
660 in6_ifa_put(ifp);
661 } else {
662 send_sllao = 0;
663 }
664 }
665#endif
666 if (send_sllao)
667 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
668
669 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
670 if (!skb)
671 return;
672
673 msg = skb_put(skb, sizeof(*msg));
674 *msg = (struct rs_msg) {
675 .icmph = {
676 .icmp6_type = NDISC_ROUTER_SOLICITATION,
677 },
678 };
679
680 if (send_sllao)
681 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
682 dev->dev_addr,
683 NDISC_ROUTER_SOLICITATION);
684
685 ndisc_send_skb(skb, daddr, saddr);
686}
687
688
689static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
690{
691 /*
692 * "The sender MUST return an ICMP
693 * destination unreachable"
694 */
695 dst_link_failure(skb);
696 kfree_skb(skb);
697}
698
699/* Called with locked neigh: either read or both */
700
701static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
702{
703 struct in6_addr *saddr = NULL;
704 struct in6_addr mcaddr;
705 struct net_device *dev = neigh->dev;
706 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
707 int probes = atomic_read(&neigh->probes);
708
709 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
710 dev, false, 1,
711 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
712 saddr = &ipv6_hdr(skb)->saddr;
713 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
714 if (probes < 0) {
715 if (!(neigh->nud_state & NUD_VALID)) {
716 ND_PRINTK(1, dbg,
717 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
718 __func__, target);
719 }
720 ndisc_send_ns(dev, target, target, saddr, 0);
721 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
722 neigh_app_ns(neigh);
723 } else {
724 addrconf_addr_solict_mult(target, &mcaddr);
725 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
726 }
727}
728
729static int pndisc_is_router(const void *pkey,
730 struct net_device *dev)
731{
732 struct pneigh_entry *n;
733 int ret = -1;
734
735 read_lock_bh(&nd_tbl.lock);
736 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
737 if (n)
738 ret = !!(n->flags & NTF_ROUTER);
739 read_unlock_bh(&nd_tbl.lock);
740
741 return ret;
742}
743
744void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
745 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
746 struct ndisc_options *ndopts)
747{
748 neigh_update(neigh, lladdr, new, flags, 0);
749 /* report ndisc ops about neighbour update */
750 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
751}
752
753static void ndisc_recv_ns(struct sk_buff *skb)
754{
755 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
756 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
757 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
758 u8 *lladdr = NULL;
759 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
760 offsetof(struct nd_msg, opt));
761 struct ndisc_options ndopts;
762 struct net_device *dev = skb->dev;
763 struct inet6_ifaddr *ifp;
764 struct inet6_dev *idev = NULL;
765 struct neighbour *neigh;
766 int dad = ipv6_addr_any(saddr);
767 bool inc;
768 int is_router = -1;
769 u64 nonce = 0;
770
771 if (skb->len < sizeof(struct nd_msg)) {
772 ND_PRINTK(2, warn, "NS: packet too short\n");
773 return;
774 }
775
776 if (ipv6_addr_is_multicast(&msg->target)) {
777 ND_PRINTK(2, warn, "NS: multicast target address\n");
778 return;
779 }
780
781 /*
782 * RFC2461 7.1.1:
783 * DAD has to be destined for solicited node multicast address.
784 */
785 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
786 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
787 return;
788 }
789
790 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
791 ND_PRINTK(2, warn, "NS: invalid ND options\n");
792 return;
793 }
794
795 if (ndopts.nd_opts_src_lladdr) {
796 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
797 if (!lladdr) {
798 ND_PRINTK(2, warn,
799 "NS: invalid link-layer address length\n");
800 return;
801 }
802
803 /* RFC2461 7.1.1:
804 * If the IP source address is the unspecified address,
805 * there MUST NOT be source link-layer address option
806 * in the message.
807 */
808 if (dad) {
809 ND_PRINTK(2, warn,
810 "NS: bad DAD packet (link-layer address option)\n");
811 return;
812 }
813 }
814 if (ndopts.nd_opts_nonce)
815 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
816
817 inc = ipv6_addr_is_multicast(daddr);
818
819 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
820 if (ifp) {
821have_ifp:
822 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
823 if (dad) {
824 if (nonce != 0 && ifp->dad_nonce == nonce) {
825 u8 *np = (u8 *)&nonce;
826 /* Matching nonce if looped back */
827 ND_PRINTK(2, notice,
828 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
829 ifp->idev->dev->name,
830 &ifp->addr, np);
831 goto out;
832 }
833 /*
834 * We are colliding with another node
835 * who is doing DAD
836 * so fail our DAD process
837 */
838 addrconf_dad_failure(skb, ifp);
839 return;
840 } else {
841 /*
842 * This is not a dad solicitation.
843 * If we are an optimistic node,
844 * we should respond.
845 * Otherwise, we should ignore it.
846 */
847 if (!(ifp->flags & IFA_F_OPTIMISTIC))
848 goto out;
849 }
850 }
851
852 idev = ifp->idev;
853 } else {
854 struct net *net = dev_net(dev);
855
856 /* perhaps an address on the master device */
857 if (netif_is_l3_slave(dev)) {
858 struct net_device *mdev;
859
860 mdev = netdev_master_upper_dev_get_rcu(dev);
861 if (mdev) {
862 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
863 if (ifp)
864 goto have_ifp;
865 }
866 }
867
868 idev = in6_dev_get(dev);
869 if (!idev) {
870 /* XXX: count this drop? */
871 return;
872 }
873
874 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
875 (idev->cnf.forwarding &&
876 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
877 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
878 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
879 skb->pkt_type != PACKET_HOST &&
880 inc &&
881 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
882 /*
883 * for anycast or proxy,
884 * sender should delay its response
885 * by a random time between 0 and
886 * MAX_ANYCAST_DELAY_TIME seconds.
887 * (RFC2461) -- yoshfuji
888 */
889 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
890 if (n)
891 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
892 goto out;
893 }
894 } else
895 goto out;
896 }
897
898 if (is_router < 0)
899 is_router = idev->cnf.forwarding;
900
901 if (dad) {
902 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
903 !!is_router, false, (ifp != NULL), true);
904 goto out;
905 }
906
907 if (inc)
908 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
909 else
910 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
911
912 /*
913 * update / create cache entry
914 * for the source address
915 */
916 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
917 !inc || lladdr || !dev->addr_len);
918 if (neigh)
919 ndisc_update(dev, neigh, lladdr, NUD_STALE,
920 NEIGH_UPDATE_F_WEAK_OVERRIDE|
921 NEIGH_UPDATE_F_OVERRIDE,
922 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
923 if (neigh || !dev->header_ops) {
924 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
925 true, (ifp != NULL && inc), inc);
926 if (neigh)
927 neigh_release(neigh);
928 }
929
930out:
931 if (ifp)
932 in6_ifa_put(ifp);
933 else
934 in6_dev_put(idev);
935}
936
937static void ndisc_recv_na(struct sk_buff *skb)
938{
939 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
940 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
941 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
942 u8 *lladdr = NULL;
943 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
944 offsetof(struct nd_msg, opt));
945 struct ndisc_options ndopts;
946 struct net_device *dev = skb->dev;
947 struct inet6_dev *idev = __in6_dev_get(dev);
948 struct inet6_ifaddr *ifp;
949 struct neighbour *neigh;
950
951 if (skb->len < sizeof(struct nd_msg)) {
952 ND_PRINTK(2, warn, "NA: packet too short\n");
953 return;
954 }
955
956 if (ipv6_addr_is_multicast(&msg->target)) {
957 ND_PRINTK(2, warn, "NA: target address is multicast\n");
958 return;
959 }
960
961 if (ipv6_addr_is_multicast(daddr) &&
962 msg->icmph.icmp6_solicited) {
963 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
964 return;
965 }
966
967 /* For some 802.11 wireless deployments (and possibly other networks),
968 * there will be a NA proxy and unsolicitd packets are attacks
969 * and thus should not be accepted.
970 */
971 if (!msg->icmph.icmp6_solicited && idev &&
972 idev->cnf.drop_unsolicited_na)
973 return;
974
975 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
976 ND_PRINTK(2, warn, "NS: invalid ND option\n");
977 return;
978 }
979 if (ndopts.nd_opts_tgt_lladdr) {
980 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
981 if (!lladdr) {
982 ND_PRINTK(2, warn,
983 "NA: invalid link-layer address length\n");
984 return;
985 }
986 }
987 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
988 if (ifp) {
989 if (skb->pkt_type != PACKET_LOOPBACK
990 && (ifp->flags & IFA_F_TENTATIVE)) {
991 addrconf_dad_failure(skb, ifp);
992 return;
993 }
994 /* What should we make now? The advertisement
995 is invalid, but ndisc specs say nothing
996 about it. It could be misconfiguration, or
997 an smart proxy agent tries to help us :-)
998
999 We should not print the error if NA has been
1000 received from loopback - it is just our own
1001 unsolicited advertisement.
1002 */
1003 if (skb->pkt_type != PACKET_LOOPBACK)
1004 ND_PRINTK(1, warn,
1005 "NA: %pM advertised our address %pI6c on %s!\n",
1006 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1007 in6_ifa_put(ifp);
1008 return;
1009 }
1010 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1011
1012 if (neigh) {
1013 u8 old_flags = neigh->flags;
1014 struct net *net = dev_net(dev);
1015
1016 if (neigh->nud_state & NUD_FAILED)
1017 goto out;
1018
1019 /*
1020 * Don't update the neighbor cache entry on a proxy NA from
1021 * ourselves because either the proxied node is off link or it
1022 * has already sent a NA to us.
1023 */
1024 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1025 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1026 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1027 /* XXX: idev->cnf.proxy_ndp */
1028 goto out;
1029 }
1030
1031 ndisc_update(dev, neigh, lladdr,
1032 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1033 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1034 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1035 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1036 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1037 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1038
1039 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1040 /*
1041 * Change: router to host
1042 */
1043 rt6_clean_tohost(dev_net(dev), saddr);
1044 }
1045
1046out:
1047 neigh_release(neigh);
1048 }
1049}
1050
1051static void ndisc_recv_rs(struct sk_buff *skb)
1052{
1053 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1054 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1055 struct neighbour *neigh;
1056 struct inet6_dev *idev;
1057 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1058 struct ndisc_options ndopts;
1059 u8 *lladdr = NULL;
1060
1061 if (skb->len < sizeof(*rs_msg))
1062 return;
1063
1064 idev = __in6_dev_get(skb->dev);
1065 if (!idev) {
1066 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1067 return;
1068 }
1069
1070 /* Don't accept RS if we're not in router mode */
1071 if (!idev->cnf.forwarding)
1072 goto out;
1073
1074 /*
1075 * Don't update NCE if src = ::;
1076 * this implies that the source node has no ip address assigned yet.
1077 */
1078 if (ipv6_addr_any(saddr))
1079 goto out;
1080
1081 /* Parse ND options */
1082 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1083 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1084 goto out;
1085 }
1086
1087 if (ndopts.nd_opts_src_lladdr) {
1088 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1089 skb->dev);
1090 if (!lladdr)
1091 goto out;
1092 }
1093
1094 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1095 if (neigh) {
1096 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1097 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1098 NEIGH_UPDATE_F_OVERRIDE|
1099 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1100 NDISC_ROUTER_SOLICITATION, &ndopts);
1101 neigh_release(neigh);
1102 }
1103out:
1104 return;
1105}
1106
1107static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1108{
1109 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1110 struct sk_buff *skb;
1111 struct nlmsghdr *nlh;
1112 struct nduseroptmsg *ndmsg;
1113 struct net *net = dev_net(ra->dev);
1114 int err;
1115 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1116 + (opt->nd_opt_len << 3));
1117 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1118
1119 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1120 if (!skb) {
1121 err = -ENOBUFS;
1122 goto errout;
1123 }
1124
1125 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1126 if (!nlh) {
1127 goto nla_put_failure;
1128 }
1129
1130 ndmsg = nlmsg_data(nlh);
1131 ndmsg->nduseropt_family = AF_INET6;
1132 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1133 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1134 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1135 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1136
1137 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1138
1139 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1140 goto nla_put_failure;
1141 nlmsg_end(skb, nlh);
1142
1143 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1144 return;
1145
1146nla_put_failure:
1147 nlmsg_free(skb);
1148 err = -EMSGSIZE;
1149errout:
1150 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1151}
1152
1153static void ndisc_router_discovery(struct sk_buff *skb)
1154{
1155 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1156 struct neighbour *neigh = NULL;
1157 struct inet6_dev *in6_dev;
1158 struct rt6_info *rt = NULL;
1159 int lifetime;
1160 struct ndisc_options ndopts;
1161 int optlen;
1162 unsigned int pref = 0;
1163 __u32 old_if_flags;
1164 bool send_ifinfo_notify = false;
1165
1166 __u8 *opt = (__u8 *)(ra_msg + 1);
1167
1168 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1169 sizeof(struct ra_msg);
1170
1171 ND_PRINTK(2, info,
1172 "RA: %s, dev: %s\n",
1173 __func__, skb->dev->name);
1174 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1175 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1176 return;
1177 }
1178 if (optlen < 0) {
1179 ND_PRINTK(2, warn, "RA: packet too short\n");
1180 return;
1181 }
1182
1183#ifdef CONFIG_IPV6_NDISC_NODETYPE
1184 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1185 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1186 return;
1187 }
1188#endif
1189
1190 /*
1191 * set the RA_RECV flag in the interface
1192 */
1193
1194 in6_dev = __in6_dev_get(skb->dev);
1195 if (!in6_dev) {
1196 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1197 skb->dev->name);
1198 return;
1199 }
1200
1201 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1202 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1203 return;
1204 }
1205
1206 if (!ipv6_accept_ra(in6_dev)) {
1207 ND_PRINTK(2, info,
1208 "RA: %s, did not accept ra for dev: %s\n",
1209 __func__, skb->dev->name);
1210 goto skip_linkparms;
1211 }
1212
1213#ifdef CONFIG_IPV6_NDISC_NODETYPE
1214 /* skip link-specific parameters from interior routers */
1215 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1216 ND_PRINTK(2, info,
1217 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1218 __func__, skb->dev->name);
1219 goto skip_linkparms;
1220 }
1221#endif
1222
1223 if (in6_dev->if_flags & IF_RS_SENT) {
1224 /*
1225 * flag that an RA was received after an RS was sent
1226 * out on this interface.
1227 */
1228 in6_dev->if_flags |= IF_RA_RCVD;
1229 }
1230
1231 /*
1232 * Remember the managed/otherconf flags from most recently
1233 * received RA message (RFC 2462) -- yoshfuji
1234 */
1235 old_if_flags = in6_dev->if_flags;
1236 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1237 IF_RA_OTHERCONF)) |
1238 (ra_msg->icmph.icmp6_addrconf_managed ?
1239 IF_RA_MANAGED : 0) |
1240 (ra_msg->icmph.icmp6_addrconf_other ?
1241 IF_RA_OTHERCONF : 0);
1242
1243 if (old_if_flags != in6_dev->if_flags)
1244 send_ifinfo_notify = true;
1245
1246 if (!in6_dev->cnf.accept_ra_defrtr) {
1247 ND_PRINTK(2, info,
1248 "RA: %s, defrtr is false for dev: %s\n",
1249 __func__, skb->dev->name);
1250 goto skip_defrtr;
1251 }
1252
1253 /* Do not accept RA with source-addr found on local machine unless
1254 * accept_ra_from_local is set to true.
1255 */
1256 if (!in6_dev->cnf.accept_ra_from_local &&
1257 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1258 in6_dev->dev, 0)) {
1259 ND_PRINTK(2, info,
1260 "RA from local address detected on dev: %s: default router ignored\n",
1261 skb->dev->name);
1262 goto skip_defrtr;
1263 }
1264
1265 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1266
1267#ifdef CONFIG_IPV6_ROUTER_PREF
1268 pref = ra_msg->icmph.icmp6_router_pref;
1269 /* 10b is handled as if it were 00b (medium) */
1270 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1271 !in6_dev->cnf.accept_ra_rtr_pref)
1272 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1273#endif
1274
1275 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1276
1277 if (rt) {
1278 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1279 if (!neigh) {
1280 ND_PRINTK(0, err,
1281 "RA: %s got default router without neighbour\n",
1282 __func__);
1283 ip6_rt_put(rt);
1284 return;
1285 }
1286 }
1287 if (rt && lifetime == 0) {
1288 ip6_del_rt(rt);
1289 rt = NULL;
1290 }
1291
1292 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1293 rt, lifetime, skb->dev->name);
1294 if (!rt && lifetime) {
1295 ND_PRINTK(3, info, "RA: adding default router\n");
1296
1297 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1298 if (!rt) {
1299 ND_PRINTK(0, err,
1300 "RA: %s failed to add default route\n",
1301 __func__);
1302 return;
1303 }
1304
1305 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1306 if (!neigh) {
1307 ND_PRINTK(0, err,
1308 "RA: %s got default router without neighbour\n",
1309 __func__);
1310 ip6_rt_put(rt);
1311 return;
1312 }
1313 neigh->flags |= NTF_ROUTER;
1314 } else if (rt) {
1315 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1316 }
1317
1318 if (rt)
1319 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1320 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1321 ra_msg->icmph.icmp6_hop_limit) {
1322 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1323 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1324 if (rt)
1325 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1326 ra_msg->icmph.icmp6_hop_limit);
1327 } else {
1328 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1329 }
1330 }
1331
1332skip_defrtr:
1333
1334 /*
1335 * Update Reachable Time and Retrans Timer
1336 */
1337
1338 if (in6_dev->nd_parms) {
1339 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1340
1341 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1342 rtime = (rtime*HZ)/1000;
1343 if (rtime < HZ/10)
1344 rtime = HZ/10;
1345 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1346 in6_dev->tstamp = jiffies;
1347 send_ifinfo_notify = true;
1348 }
1349
1350 rtime = ntohl(ra_msg->reachable_time);
1351 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1352 rtime = (rtime*HZ)/1000;
1353
1354 if (rtime < HZ/10)
1355 rtime = HZ/10;
1356
1357 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1358 NEIGH_VAR_SET(in6_dev->nd_parms,
1359 BASE_REACHABLE_TIME, rtime);
1360 NEIGH_VAR_SET(in6_dev->nd_parms,
1361 GC_STALETIME, 3 * rtime);
1362 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1363 in6_dev->tstamp = jiffies;
1364 send_ifinfo_notify = true;
1365 }
1366 }
1367 }
1368
1369 /*
1370 * Send a notify if RA changed managed/otherconf flags or timer settings
1371 */
1372 if (send_ifinfo_notify)
1373 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1374
1375skip_linkparms:
1376
1377 /*
1378 * Process options.
1379 */
1380
1381 if (!neigh)
1382 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1383 skb->dev, 1);
1384 if (neigh) {
1385 u8 *lladdr = NULL;
1386 if (ndopts.nd_opts_src_lladdr) {
1387 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1388 skb->dev);
1389 if (!lladdr) {
1390 ND_PRINTK(2, warn,
1391 "RA: invalid link-layer address length\n");
1392 goto out;
1393 }
1394 }
1395 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1396 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1397 NEIGH_UPDATE_F_OVERRIDE|
1398 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1399 NEIGH_UPDATE_F_ISROUTER,
1400 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1401 }
1402
1403 if (!ipv6_accept_ra(in6_dev)) {
1404 ND_PRINTK(2, info,
1405 "RA: %s, accept_ra is false for dev: %s\n",
1406 __func__, skb->dev->name);
1407 goto out;
1408 }
1409
1410#ifdef CONFIG_IPV6_ROUTE_INFO
1411 if (!in6_dev->cnf.accept_ra_from_local &&
1412 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1413 in6_dev->dev, 0)) {
1414 ND_PRINTK(2, info,
1415 "RA from local address detected on dev: %s: router info ignored.\n",
1416 skb->dev->name);
1417 goto skip_routeinfo;
1418 }
1419
1420 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1421 struct nd_opt_hdr *p;
1422 for (p = ndopts.nd_opts_ri;
1423 p;
1424 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1425 struct route_info *ri = (struct route_info *)p;
1426#ifdef CONFIG_IPV6_NDISC_NODETYPE
1427 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1428 ri->prefix_len == 0)
1429 continue;
1430#endif
1431 if (ri->prefix_len == 0 &&
1432 !in6_dev->cnf.accept_ra_defrtr)
1433 continue;
1434 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1435 continue;
1436 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1437 continue;
1438 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1439 &ipv6_hdr(skb)->saddr);
1440 }
1441 }
1442
1443skip_routeinfo:
1444#endif
1445
1446#ifdef CONFIG_IPV6_NDISC_NODETYPE
1447 /* skip link-specific ndopts from interior routers */
1448 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1449 ND_PRINTK(2, info,
1450 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1451 __func__, skb->dev->name);
1452 goto out;
1453 }
1454#endif
1455
1456 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1457 struct nd_opt_hdr *p;
1458 for (p = ndopts.nd_opts_pi;
1459 p;
1460 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1461 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1462 (p->nd_opt_len) << 3,
1463 ndopts.nd_opts_src_lladdr != NULL);
1464 }
1465 }
1466
1467 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1468 __be32 n;
1469 u32 mtu;
1470
1471 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1472 mtu = ntohl(n);
1473
1474 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1475 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1476 } else if (in6_dev->cnf.mtu6 != mtu) {
1477 in6_dev->cnf.mtu6 = mtu;
1478
1479 if (rt)
1480 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1481
1482 rt6_mtu_change(skb->dev, mtu);
1483 }
1484 }
1485
1486 if (ndopts.nd_useropts) {
1487 struct nd_opt_hdr *p;
1488 for (p = ndopts.nd_useropts;
1489 p;
1490 p = ndisc_next_useropt(skb->dev, p,
1491 ndopts.nd_useropts_end)) {
1492 ndisc_ra_useropt(skb, p);
1493 }
1494 }
1495
1496 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1497 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1498 }
1499out:
1500 ip6_rt_put(rt);
1501 if (neigh)
1502 neigh_release(neigh);
1503}
1504
1505static void ndisc_redirect_rcv(struct sk_buff *skb)
1506{
1507 u8 *hdr;
1508 struct ndisc_options ndopts;
1509 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1510 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1511 offsetof(struct rd_msg, opt));
1512
1513#ifdef CONFIG_IPV6_NDISC_NODETYPE
1514 switch (skb->ndisc_nodetype) {
1515 case NDISC_NODETYPE_HOST:
1516 case NDISC_NODETYPE_NODEFAULT:
1517 ND_PRINTK(2, warn,
1518 "Redirect: from host or unauthorized router\n");
1519 return;
1520 }
1521#endif
1522
1523 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1524 ND_PRINTK(2, warn,
1525 "Redirect: source address is not link-local\n");
1526 return;
1527 }
1528
1529 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1530 return;
1531
1532 if (!ndopts.nd_opts_rh) {
1533 ip6_redirect_no_header(skb, dev_net(skb->dev),
1534 skb->dev->ifindex, 0);
1535 return;
1536 }
1537
1538 hdr = (u8 *)ndopts.nd_opts_rh;
1539 hdr += 8;
1540 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1541 return;
1542
1543 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1544}
1545
1546static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1547 struct sk_buff *orig_skb,
1548 int rd_len)
1549{
1550 u8 *opt = skb_put(skb, rd_len);
1551
1552 memset(opt, 0, 8);
1553 *(opt++) = ND_OPT_REDIRECT_HDR;
1554 *(opt++) = (rd_len >> 3);
1555 opt += 6;
1556
1557 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1558 rd_len - 8);
1559}
1560
1561void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1562{
1563 struct net_device *dev = skb->dev;
1564 struct net *net = dev_net(dev);
1565 struct sock *sk = net->ipv6.ndisc_sk;
1566 int optlen = 0;
1567 struct inet_peer *peer;
1568 struct sk_buff *buff;
1569 struct rd_msg *msg;
1570 struct in6_addr saddr_buf;
1571 struct rt6_info *rt;
1572 struct dst_entry *dst;
1573 struct flowi6 fl6;
1574 int rd_len;
1575 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1576 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1577 bool ret;
1578
1579 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1580 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1581 dev->name);
1582 return;
1583 }
1584
1585 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1586 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1587 ND_PRINTK(2, warn,
1588 "Redirect: target address is not link-local unicast\n");
1589 return;
1590 }
1591
1592 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1593 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1594
1595 dst = ip6_route_output(net, NULL, &fl6);
1596 if (dst->error) {
1597 dst_release(dst);
1598 return;
1599 }
1600 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1601 if (IS_ERR(dst))
1602 return;
1603
1604 rt = (struct rt6_info *) dst;
1605
1606 if (rt->rt6i_flags & RTF_GATEWAY) {
1607 ND_PRINTK(2, warn,
1608 "Redirect: destination is not a neighbour\n");
1609 goto release;
1610 }
1611 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1612 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1613 if (peer)
1614 inet_putpeer(peer);
1615 if (!ret)
1616 goto release;
1617
1618 if (dev->addr_len) {
1619 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1620 if (!neigh) {
1621 ND_PRINTK(2, warn,
1622 "Redirect: no neigh for target address\n");
1623 goto release;
1624 }
1625
1626 read_lock_bh(&neigh->lock);
1627 if (neigh->nud_state & NUD_VALID) {
1628 memcpy(ha_buf, neigh->ha, dev->addr_len);
1629 read_unlock_bh(&neigh->lock);
1630 ha = ha_buf;
1631 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1632 ops_data_buf,
1633 &ops_data);
1634 } else
1635 read_unlock_bh(&neigh->lock);
1636
1637 neigh_release(neigh);
1638 }
1639
1640 rd_len = min_t(unsigned int,
1641 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1642 skb->len + 8);
1643 rd_len &= ~0x7;
1644 optlen += rd_len;
1645
1646 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1647 if (!buff)
1648 goto release;
1649
1650 msg = skb_put(buff, sizeof(*msg));
1651 *msg = (struct rd_msg) {
1652 .icmph = {
1653 .icmp6_type = NDISC_REDIRECT,
1654 },
1655 .target = *target,
1656 .dest = ipv6_hdr(skb)->daddr,
1657 };
1658
1659 /*
1660 * include target_address option
1661 */
1662
1663 if (ha)
1664 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1665
1666 /*
1667 * build redirect option and copy skb over to the new packet.
1668 */
1669
1670 if (rd_len)
1671 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1672
1673 skb_dst_set(buff, dst);
1674 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1675 return;
1676
1677release:
1678 dst_release(dst);
1679}
1680
1681static void pndisc_redo(struct sk_buff *skb)
1682{
1683 ndisc_recv_ns(skb);
1684 kfree_skb(skb);
1685}
1686
1687static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1688{
1689 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1690
1691 if (!idev)
1692 return true;
1693 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1694 idev->cnf.suppress_frag_ndisc) {
1695 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1696 return true;
1697 }
1698 return false;
1699}
1700
1701int ndisc_rcv(struct sk_buff *skb)
1702{
1703 struct nd_msg *msg;
1704
1705 if (ndisc_suppress_frag_ndisc(skb))
1706 return 0;
1707
1708 if (skb_linearize(skb))
1709 return 0;
1710
1711 msg = (struct nd_msg *)skb_transport_header(skb);
1712
1713 __skb_push(skb, skb->data - skb_transport_header(skb));
1714
1715 if (ipv6_hdr(skb)->hop_limit != 255) {
1716 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1717 ipv6_hdr(skb)->hop_limit);
1718 return 0;
1719 }
1720
1721 if (msg->icmph.icmp6_code != 0) {
1722 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1723 msg->icmph.icmp6_code);
1724 return 0;
1725 }
1726
1727 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1728
1729 switch (msg->icmph.icmp6_type) {
1730 case NDISC_NEIGHBOUR_SOLICITATION:
1731 ndisc_recv_ns(skb);
1732 break;
1733
1734 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1735 ndisc_recv_na(skb);
1736 break;
1737
1738 case NDISC_ROUTER_SOLICITATION:
1739 ndisc_recv_rs(skb);
1740 break;
1741
1742 case NDISC_ROUTER_ADVERTISEMENT:
1743 ndisc_router_discovery(skb);
1744 break;
1745
1746 case NDISC_REDIRECT:
1747 ndisc_redirect_rcv(skb);
1748 break;
1749 }
1750
1751 return 0;
1752}
1753
1754static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1755{
1756 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1757 struct netdev_notifier_change_info *change_info;
1758 struct net *net = dev_net(dev);
1759 struct inet6_dev *idev;
1760
1761 switch (event) {
1762 case NETDEV_CHANGEADDR:
1763 neigh_changeaddr(&nd_tbl, dev);
1764 fib6_run_gc(0, net, false);
1765 /* fallthrough */
1766 case NETDEV_UP:
1767 idev = in6_dev_get(dev);
1768 if (!idev)
1769 break;
1770 if (idev->cnf.ndisc_notify ||
1771 net->ipv6.devconf_all->ndisc_notify)
1772 ndisc_send_unsol_na(dev);
1773 in6_dev_put(idev);
1774 break;
1775 case NETDEV_CHANGE:
1776 change_info = ptr;
1777 if (change_info->flags_changed & IFF_NOARP)
1778 neigh_changeaddr(&nd_tbl, dev);
1779 break;
1780 case NETDEV_DOWN:
1781 neigh_ifdown(&nd_tbl, dev);
1782 fib6_run_gc(0, net, false);
1783 break;
1784 case NETDEV_NOTIFY_PEERS:
1785 ndisc_send_unsol_na(dev);
1786 break;
1787 default:
1788 break;
1789 }
1790
1791 return NOTIFY_DONE;
1792}
1793
1794static struct notifier_block ndisc_netdev_notifier = {
1795 .notifier_call = ndisc_netdev_event,
1796 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1797};
1798
1799#ifdef CONFIG_SYSCTL
1800static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1801 const char *func, const char *dev_name)
1802{
1803 static char warncomm[TASK_COMM_LEN];
1804 static int warned;
1805 if (strcmp(warncomm, current->comm) && warned < 5) {
1806 strcpy(warncomm, current->comm);
1807 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1808 warncomm, func,
1809 dev_name, ctl->procname,
1810 dev_name, ctl->procname);
1811 warned++;
1812 }
1813}
1814
1815int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1816{
1817 struct net_device *dev = ctl->extra1;
1818 struct inet6_dev *idev;
1819 int ret;
1820
1821 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1822 (strcmp(ctl->procname, "base_reachable_time") == 0))
1823 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1824
1825 if (strcmp(ctl->procname, "retrans_time") == 0)
1826 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1827
1828 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1829 ret = neigh_proc_dointvec_jiffies(ctl, write,
1830 buffer, lenp, ppos);
1831
1832 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1833 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1834 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1835 buffer, lenp, ppos);
1836 else
1837 ret = -1;
1838
1839 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1840 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1841 idev->nd_parms->reachable_time =
1842 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1843 idev->tstamp = jiffies;
1844 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1845 in6_dev_put(idev);
1846 }
1847 return ret;
1848}
1849
1850
1851#endif
1852
1853static int __net_init ndisc_net_init(struct net *net)
1854{
1855 struct ipv6_pinfo *np;
1856 struct sock *sk;
1857 int err;
1858
1859 err = inet_ctl_sock_create(&sk, PF_INET6,
1860 SOCK_RAW, IPPROTO_ICMPV6, net);
1861 if (err < 0) {
1862 ND_PRINTK(0, err,
1863 "NDISC: Failed to initialize the control socket (err %d)\n",
1864 err);
1865 return err;
1866 }
1867
1868 net->ipv6.ndisc_sk = sk;
1869
1870 np = inet6_sk(sk);
1871 np->hop_limit = 255;
1872 /* Do not loopback ndisc messages */
1873 np->mc_loop = 0;
1874
1875 return 0;
1876}
1877
1878static void __net_exit ndisc_net_exit(struct net *net)
1879{
1880 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1881}
1882
1883static struct pernet_operations ndisc_net_ops = {
1884 .init = ndisc_net_init,
1885 .exit = ndisc_net_exit,
1886};
1887
1888int __init ndisc_init(void)
1889{
1890 int err;
1891
1892 err = register_pernet_subsys(&ndisc_net_ops);
1893 if (err)
1894 return err;
1895 /*
1896 * Initialize the neighbour table
1897 */
1898 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1899
1900#ifdef CONFIG_SYSCTL
1901 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1902 ndisc_ifinfo_sysctl_change);
1903 if (err)
1904 goto out_unregister_pernet;
1905out:
1906#endif
1907 return err;
1908
1909#ifdef CONFIG_SYSCTL
1910out_unregister_pernet:
1911 unregister_pernet_subsys(&ndisc_net_ops);
1912 goto out;
1913#endif
1914}
1915
1916int __init ndisc_late_init(void)
1917{
1918 return register_netdevice_notifier(&ndisc_netdev_notifier);
1919}
1920
1921void ndisc_late_cleanup(void)
1922{
1923 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1924}
1925
1926void ndisc_cleanup(void)
1927{
1928#ifdef CONFIG_SYSCTL
1929 neigh_sysctl_unregister(&nd_tbl.parms);
1930#endif
1931 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1932 unregister_pernet_subsys(&ndisc_net_ops);
1933}