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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Neighbour Discovery for IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Mike Shaver <shaver@ingenia.com>
9 */
10
11/*
12 * Changes:
13 *
14 * Alexey I. Froloff : RFC6106 (DNSSL) support
15 * Pierre Ynard : export userland ND options
16 * through netlink (RDNSS support)
17 * Lars Fenneberg : fixed MTU setting on receipt
18 * of an RA.
19 * Janos Farkas : kmalloc failure checks
20 * Alexey Kuznetsov : state machine reworked
21 * and moved to net/core.
22 * Pekka Savola : RFC2461 validation
23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
24 */
25
26#define pr_fmt(fmt) "ICMPv6: " fmt
27
28#include <linux/module.h>
29#include <linux/errno.h>
30#include <linux/types.h>
31#include <linux/socket.h>
32#include <linux/sockios.h>
33#include <linux/sched.h>
34#include <linux/net.h>
35#include <linux/in6.h>
36#include <linux/route.h>
37#include <linux/init.h>
38#include <linux/rcupdate.h>
39#include <linux/slab.h>
40#ifdef CONFIG_SYSCTL
41#include <linux/sysctl.h>
42#endif
43
44#include <linux/if_addr.h>
45#include <linux/if_ether.h>
46#include <linux/if_arp.h>
47#include <linux/ipv6.h>
48#include <linux/icmpv6.h>
49#include <linux/jhash.h>
50
51#include <net/sock.h>
52#include <net/snmp.h>
53
54#include <net/ipv6.h>
55#include <net/protocol.h>
56#include <net/ndisc.h>
57#include <net/ip6_route.h>
58#include <net/addrconf.h>
59#include <net/icmp.h>
60
61#include <net/netlink.h>
62#include <linux/rtnetlink.h>
63
64#include <net/flow.h>
65#include <net/ip6_checksum.h>
66#include <net/inet_common.h>
67#include <linux/proc_fs.h>
68
69#include <linux/netfilter.h>
70#include <linux/netfilter_ipv6.h>
71
72static u32 ndisc_hash(const void *pkey,
73 const struct net_device *dev,
74 __u32 *hash_rnd);
75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
76static bool ndisc_allow_add(const struct net_device *dev,
77 struct netlink_ext_ack *extack);
78static int ndisc_constructor(struct neighbour *neigh);
79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
81static int pndisc_constructor(struct pneigh_entry *n);
82static void pndisc_destructor(struct pneigh_entry *n);
83static void pndisc_redo(struct sk_buff *skb);
84static int ndisc_is_multicast(const void *pkey);
85
86static const struct neigh_ops ndisc_generic_ops = {
87 .family = AF_INET6,
88 .solicit = ndisc_solicit,
89 .error_report = ndisc_error_report,
90 .output = neigh_resolve_output,
91 .connected_output = neigh_connected_output,
92};
93
94static const struct neigh_ops ndisc_hh_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_resolve_output,
100};
101
102
103static const struct neigh_ops ndisc_direct_ops = {
104 .family = AF_INET6,
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
107};
108
109struct neigh_table nd_tbl = {
110 .family = AF_INET6,
111 .key_len = sizeof(struct in6_addr),
112 .protocol = cpu_to_be16(ETH_P_IPV6),
113 .hash = ndisc_hash,
114 .key_eq = ndisc_key_eq,
115 .constructor = ndisc_constructor,
116 .pconstructor = pndisc_constructor,
117 .pdestructor = pndisc_destructor,
118 .proxy_redo = pndisc_redo,
119 .is_multicast = ndisc_is_multicast,
120 .allow_add = ndisc_allow_add,
121 .id = "ndisc_cache",
122 .parms = {
123 .tbl = &nd_tbl,
124 .reachable_time = ND_REACHABLE_TIME,
125 .data = {
126 [NEIGH_VAR_MCAST_PROBES] = 3,
127 [NEIGH_VAR_UCAST_PROBES] = 3,
128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
131 [NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ,
132 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
133 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
134 [NEIGH_VAR_PROXY_QLEN] = 64,
135 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
136 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
137 },
138 },
139 .gc_interval = 30 * HZ,
140 .gc_thresh1 = 128,
141 .gc_thresh2 = 512,
142 .gc_thresh3 = 1024,
143};
144EXPORT_SYMBOL_GPL(nd_tbl);
145
146void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data,
147 int data_len, int pad)
148{
149 int space = __ndisc_opt_addr_space(data_len, pad);
150 u8 *opt = skb_put(skb, space);
151
152 opt[0] = type;
153 opt[1] = space>>3;
154
155 memset(opt + 2, 0, pad);
156 opt += pad;
157 space -= pad;
158
159 memcpy(opt+2, data, data_len);
160 data_len += 2;
161 opt += data_len;
162 space -= data_len;
163 if (space > 0)
164 memset(opt, 0, space);
165}
166EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
167
168static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
169 const void *data, u8 icmp6_type)
170{
171 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
172 ndisc_addr_option_pad(skb->dev->type));
173 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
174}
175
176static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
177 void *ha,
178 const u8 *ops_data)
179{
180 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
181 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
182}
183
184static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
185 struct nd_opt_hdr *end)
186{
187 int type;
188 if (!cur || !end || cur >= end)
189 return NULL;
190 type = cur->nd_opt_type;
191 do {
192 cur = ((void *)cur) + (cur->nd_opt_len << 3);
193 } while (cur < end && cur->nd_opt_type != type);
194 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
195}
196
197static inline int ndisc_is_useropt(const struct net_device *dev,
198 struct nd_opt_hdr *opt)
199{
200 return opt->nd_opt_type == ND_OPT_PREFIX_INFO ||
201 opt->nd_opt_type == ND_OPT_RDNSS ||
202 opt->nd_opt_type == ND_OPT_DNSSL ||
203 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
204 opt->nd_opt_type == ND_OPT_PREF64 ||
205 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
206}
207
208static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
209 struct nd_opt_hdr *cur,
210 struct nd_opt_hdr *end)
211{
212 if (!cur || !end || cur >= end)
213 return NULL;
214 do {
215 cur = ((void *)cur) + (cur->nd_opt_len << 3);
216 } while (cur < end && !ndisc_is_useropt(dev, cur));
217 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
218}
219
220struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
221 u8 *opt, int opt_len,
222 struct ndisc_options *ndopts)
223{
224 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
225
226 if (!nd_opt || opt_len < 0 || !ndopts)
227 return NULL;
228 memset(ndopts, 0, sizeof(*ndopts));
229 while (opt_len) {
230 int l;
231 if (opt_len < sizeof(struct nd_opt_hdr))
232 return NULL;
233 l = nd_opt->nd_opt_len << 3;
234 if (opt_len < l || l == 0)
235 return NULL;
236 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
237 goto next_opt;
238 switch (nd_opt->nd_opt_type) {
239 case ND_OPT_SOURCE_LL_ADDR:
240 case ND_OPT_TARGET_LL_ADDR:
241 case ND_OPT_MTU:
242 case ND_OPT_NONCE:
243 case ND_OPT_REDIRECT_HDR:
244 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
245 ND_PRINTK(2, warn,
246 "%s: duplicated ND6 option found: type=%d\n",
247 __func__, nd_opt->nd_opt_type);
248 } else {
249 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
250 }
251 break;
252 case ND_OPT_PREFIX_INFO:
253 ndopts->nd_opts_pi_end = nd_opt;
254 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
255 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
256 break;
257#ifdef CONFIG_IPV6_ROUTE_INFO
258 case ND_OPT_ROUTE_INFO:
259 ndopts->nd_opts_ri_end = nd_opt;
260 if (!ndopts->nd_opts_ri)
261 ndopts->nd_opts_ri = nd_opt;
262 break;
263#endif
264 default:
265 if (ndisc_is_useropt(dev, nd_opt)) {
266 ndopts->nd_useropts_end = nd_opt;
267 if (!ndopts->nd_useropts)
268 ndopts->nd_useropts = nd_opt;
269 } else {
270 /*
271 * Unknown options must be silently ignored,
272 * to accommodate future extension to the
273 * protocol.
274 */
275 ND_PRINTK(2, notice,
276 "%s: ignored unsupported option; type=%d, len=%d\n",
277 __func__,
278 nd_opt->nd_opt_type,
279 nd_opt->nd_opt_len);
280 }
281 }
282next_opt:
283 opt_len -= l;
284 nd_opt = ((void *)nd_opt) + l;
285 }
286 return ndopts;
287}
288
289int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
290{
291 switch (dev->type) {
292 case ARPHRD_ETHER:
293 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
294 case ARPHRD_FDDI:
295 ipv6_eth_mc_map(addr, buf);
296 return 0;
297 case ARPHRD_ARCNET:
298 ipv6_arcnet_mc_map(addr, buf);
299 return 0;
300 case ARPHRD_INFINIBAND:
301 ipv6_ib_mc_map(addr, dev->broadcast, buf);
302 return 0;
303 case ARPHRD_IPGRE:
304 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
305 default:
306 if (dir) {
307 memcpy(buf, dev->broadcast, dev->addr_len);
308 return 0;
309 }
310 }
311 return -EINVAL;
312}
313EXPORT_SYMBOL(ndisc_mc_map);
314
315static u32 ndisc_hash(const void *pkey,
316 const struct net_device *dev,
317 __u32 *hash_rnd)
318{
319 return ndisc_hashfn(pkey, dev, hash_rnd);
320}
321
322static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
323{
324 return neigh_key_eq128(n, pkey);
325}
326
327static int ndisc_constructor(struct neighbour *neigh)
328{
329 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
330 struct net_device *dev = neigh->dev;
331 struct inet6_dev *in6_dev;
332 struct neigh_parms *parms;
333 bool is_multicast = ipv6_addr_is_multicast(addr);
334
335 in6_dev = in6_dev_get(dev);
336 if (!in6_dev) {
337 return -EINVAL;
338 }
339
340 parms = in6_dev->nd_parms;
341 __neigh_parms_put(neigh->parms);
342 neigh->parms = neigh_parms_clone(parms);
343
344 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
345 if (!dev->header_ops) {
346 neigh->nud_state = NUD_NOARP;
347 neigh->ops = &ndisc_direct_ops;
348 neigh->output = neigh_direct_output;
349 } else {
350 if (is_multicast) {
351 neigh->nud_state = NUD_NOARP;
352 ndisc_mc_map(addr, neigh->ha, dev, 1);
353 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
354 neigh->nud_state = NUD_NOARP;
355 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
356 if (dev->flags&IFF_LOOPBACK)
357 neigh->type = RTN_LOCAL;
358 } else if (dev->flags&IFF_POINTOPOINT) {
359 neigh->nud_state = NUD_NOARP;
360 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
361 }
362 if (dev->header_ops->cache)
363 neigh->ops = &ndisc_hh_ops;
364 else
365 neigh->ops = &ndisc_generic_ops;
366 if (neigh->nud_state&NUD_VALID)
367 neigh->output = neigh->ops->connected_output;
368 else
369 neigh->output = neigh->ops->output;
370 }
371 in6_dev_put(in6_dev);
372 return 0;
373}
374
375static int pndisc_constructor(struct pneigh_entry *n)
376{
377 struct in6_addr *addr = (struct in6_addr *)&n->key;
378 struct in6_addr maddr;
379 struct net_device *dev = n->dev;
380
381 if (!dev || !__in6_dev_get(dev))
382 return -EINVAL;
383 addrconf_addr_solict_mult(addr, &maddr);
384 ipv6_dev_mc_inc(dev, &maddr);
385 return 0;
386}
387
388static void pndisc_destructor(struct pneigh_entry *n)
389{
390 struct in6_addr *addr = (struct in6_addr *)&n->key;
391 struct in6_addr maddr;
392 struct net_device *dev = n->dev;
393
394 if (!dev || !__in6_dev_get(dev))
395 return;
396 addrconf_addr_solict_mult(addr, &maddr);
397 ipv6_dev_mc_dec(dev, &maddr);
398}
399
400/* called with rtnl held */
401static bool ndisc_allow_add(const struct net_device *dev,
402 struct netlink_ext_ack *extack)
403{
404 struct inet6_dev *idev = __in6_dev_get(dev);
405
406 if (!idev || idev->cnf.disable_ipv6) {
407 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
408 return false;
409 }
410
411 return true;
412}
413
414static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
415 int len)
416{
417 int hlen = LL_RESERVED_SPACE(dev);
418 int tlen = dev->needed_tailroom;
419 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
420 struct sk_buff *skb;
421
422 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
423 if (!skb) {
424 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
425 __func__);
426 return NULL;
427 }
428
429 skb->protocol = htons(ETH_P_IPV6);
430 skb->dev = dev;
431
432 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
433 skb_reset_transport_header(skb);
434
435 /* Manually assign socket ownership as we avoid calling
436 * sock_alloc_send_pskb() to bypass wmem buffer limits
437 */
438 skb_set_owner_w(skb, sk);
439
440 return skb;
441}
442
443static void ip6_nd_hdr(struct sk_buff *skb,
444 const struct in6_addr *saddr,
445 const struct in6_addr *daddr,
446 int hop_limit, int len)
447{
448 struct ipv6hdr *hdr;
449 struct inet6_dev *idev;
450 unsigned tclass;
451
452 rcu_read_lock();
453 idev = __in6_dev_get(skb->dev);
454 tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0;
455 rcu_read_unlock();
456
457 skb_push(skb, sizeof(*hdr));
458 skb_reset_network_header(skb);
459 hdr = ipv6_hdr(skb);
460
461 ip6_flow_hdr(hdr, tclass, 0);
462
463 hdr->payload_len = htons(len);
464 hdr->nexthdr = IPPROTO_ICMPV6;
465 hdr->hop_limit = hop_limit;
466
467 hdr->saddr = *saddr;
468 hdr->daddr = *daddr;
469}
470
471void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
472 const struct in6_addr *saddr)
473{
474 struct dst_entry *dst = skb_dst(skb);
475 struct net *net = dev_net(skb->dev);
476 struct sock *sk = net->ipv6.ndisc_sk;
477 struct inet6_dev *idev;
478 int err;
479 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
480 u8 type;
481
482 type = icmp6h->icmp6_type;
483
484 if (!dst) {
485 struct flowi6 fl6;
486 int oif = skb->dev->ifindex;
487
488 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
489 dst = icmp6_dst_alloc(skb->dev, &fl6);
490 if (IS_ERR(dst)) {
491 kfree_skb(skb);
492 return;
493 }
494
495 skb_dst_set(skb, dst);
496 }
497
498 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
499 IPPROTO_ICMPV6,
500 csum_partial(icmp6h,
501 skb->len, 0));
502
503 ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len);
504
505 rcu_read_lock();
506 idev = __in6_dev_get(dst->dev);
507 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
508
509 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
510 net, sk, skb, NULL, dst->dev,
511 dst_output);
512 if (!err) {
513 ICMP6MSGOUT_INC_STATS(net, idev, type);
514 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
515 }
516
517 rcu_read_unlock();
518}
519EXPORT_SYMBOL(ndisc_send_skb);
520
521void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
522 const struct in6_addr *solicited_addr,
523 bool router, bool solicited, bool override, bool inc_opt)
524{
525 struct sk_buff *skb;
526 struct in6_addr tmpaddr;
527 struct inet6_ifaddr *ifp;
528 const struct in6_addr *src_addr;
529 struct nd_msg *msg;
530 int optlen = 0;
531
532 /* for anycast or proxy, solicited_addr != src_addr */
533 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
534 if (ifp) {
535 src_addr = solicited_addr;
536 if (ifp->flags & IFA_F_OPTIMISTIC)
537 override = false;
538 inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao);
539 in6_ifa_put(ifp);
540 } else {
541 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
542 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
543 &tmpaddr))
544 return;
545 src_addr = &tmpaddr;
546 }
547
548 if (!dev->addr_len)
549 inc_opt = false;
550 if (inc_opt)
551 optlen += ndisc_opt_addr_space(dev,
552 NDISC_NEIGHBOUR_ADVERTISEMENT);
553
554 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
555 if (!skb)
556 return;
557
558 msg = skb_put(skb, sizeof(*msg));
559 *msg = (struct nd_msg) {
560 .icmph = {
561 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
562 .icmp6_router = router,
563 .icmp6_solicited = solicited,
564 .icmp6_override = override,
565 },
566 .target = *solicited_addr,
567 };
568
569 if (inc_opt)
570 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
571 dev->dev_addr,
572 NDISC_NEIGHBOUR_ADVERTISEMENT);
573
574 ndisc_send_skb(skb, daddr, src_addr);
575}
576
577static void ndisc_send_unsol_na(struct net_device *dev)
578{
579 struct inet6_dev *idev;
580 struct inet6_ifaddr *ifa;
581
582 idev = in6_dev_get(dev);
583 if (!idev)
584 return;
585
586 read_lock_bh(&idev->lock);
587 list_for_each_entry(ifa, &idev->addr_list, if_list) {
588 /* skip tentative addresses until dad completes */
589 if (ifa->flags & IFA_F_TENTATIVE &&
590 !(ifa->flags & IFA_F_OPTIMISTIC))
591 continue;
592
593 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
594 /*router=*/ !!idev->cnf.forwarding,
595 /*solicited=*/ false, /*override=*/ true,
596 /*inc_opt=*/ true);
597 }
598 read_unlock_bh(&idev->lock);
599
600 in6_dev_put(idev);
601}
602
603struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
604 const struct in6_addr *saddr, u64 nonce)
605{
606 int inc_opt = dev->addr_len;
607 struct sk_buff *skb;
608 struct nd_msg *msg;
609 int optlen = 0;
610
611 if (!saddr)
612 return NULL;
613
614 if (ipv6_addr_any(saddr))
615 inc_opt = false;
616 if (inc_opt)
617 optlen += ndisc_opt_addr_space(dev,
618 NDISC_NEIGHBOUR_SOLICITATION);
619 if (nonce != 0)
620 optlen += 8;
621
622 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
623 if (!skb)
624 return NULL;
625
626 msg = skb_put(skb, sizeof(*msg));
627 *msg = (struct nd_msg) {
628 .icmph = {
629 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
630 },
631 .target = *solicit,
632 };
633
634 if (inc_opt)
635 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
636 dev->dev_addr,
637 NDISC_NEIGHBOUR_SOLICITATION);
638 if (nonce != 0) {
639 u8 *opt = skb_put(skb, 8);
640
641 opt[0] = ND_OPT_NONCE;
642 opt[1] = 8 >> 3;
643 memcpy(opt + 2, &nonce, 6);
644 }
645
646 return skb;
647}
648EXPORT_SYMBOL(ndisc_ns_create);
649
650void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
651 const struct in6_addr *daddr, const struct in6_addr *saddr,
652 u64 nonce)
653{
654 struct in6_addr addr_buf;
655 struct sk_buff *skb;
656
657 if (!saddr) {
658 if (ipv6_get_lladdr(dev, &addr_buf,
659 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
660 return;
661 saddr = &addr_buf;
662 }
663
664 skb = ndisc_ns_create(dev, solicit, saddr, nonce);
665
666 if (skb)
667 ndisc_send_skb(skb, daddr, saddr);
668}
669
670void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
671 const struct in6_addr *daddr)
672{
673 struct sk_buff *skb;
674 struct rs_msg *msg;
675 int send_sllao = dev->addr_len;
676 int optlen = 0;
677
678#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
679 /*
680 * According to section 2.2 of RFC 4429, we must not
681 * send router solicitations with a sllao from
682 * optimistic addresses, but we may send the solicitation
683 * if we don't include the sllao. So here we check
684 * if our address is optimistic, and if so, we
685 * suppress the inclusion of the sllao.
686 */
687 if (send_sllao) {
688 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
689 dev, 1);
690 if (ifp) {
691 if (ifp->flags & IFA_F_OPTIMISTIC) {
692 send_sllao = 0;
693 }
694 in6_ifa_put(ifp);
695 } else {
696 send_sllao = 0;
697 }
698 }
699#endif
700 if (send_sllao)
701 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
702
703 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
704 if (!skb)
705 return;
706
707 msg = skb_put(skb, sizeof(*msg));
708 *msg = (struct rs_msg) {
709 .icmph = {
710 .icmp6_type = NDISC_ROUTER_SOLICITATION,
711 },
712 };
713
714 if (send_sllao)
715 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
716 dev->dev_addr,
717 NDISC_ROUTER_SOLICITATION);
718
719 ndisc_send_skb(skb, daddr, saddr);
720}
721
722
723static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
724{
725 /*
726 * "The sender MUST return an ICMP
727 * destination unreachable"
728 */
729 dst_link_failure(skb);
730 kfree_skb(skb);
731}
732
733/* Called with locked neigh: either read or both */
734
735static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
736{
737 struct in6_addr *saddr = NULL;
738 struct in6_addr mcaddr;
739 struct net_device *dev = neigh->dev;
740 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
741 int probes = atomic_read(&neigh->probes);
742
743 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
744 dev, false, 1,
745 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
746 saddr = &ipv6_hdr(skb)->saddr;
747 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
748 if (probes < 0) {
749 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) {
750 ND_PRINTK(1, dbg,
751 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
752 __func__, target);
753 }
754 ndisc_send_ns(dev, target, target, saddr, 0);
755 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
756 neigh_app_ns(neigh);
757 } else {
758 addrconf_addr_solict_mult(target, &mcaddr);
759 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
760 }
761}
762
763static int pndisc_is_router(const void *pkey,
764 struct net_device *dev)
765{
766 struct pneigh_entry *n;
767 int ret = -1;
768
769 read_lock_bh(&nd_tbl.lock);
770 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
771 if (n)
772 ret = !!(n->flags & NTF_ROUTER);
773 read_unlock_bh(&nd_tbl.lock);
774
775 return ret;
776}
777
778void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
779 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
780 struct ndisc_options *ndopts)
781{
782 neigh_update(neigh, lladdr, new, flags, 0);
783 /* report ndisc ops about neighbour update */
784 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
785}
786
787static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
788{
789 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
790 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
791 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
792 u8 *lladdr = NULL;
793 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
794 offsetof(struct nd_msg, opt));
795 struct ndisc_options ndopts;
796 struct net_device *dev = skb->dev;
797 struct inet6_ifaddr *ifp;
798 struct inet6_dev *idev = NULL;
799 struct neighbour *neigh;
800 int dad = ipv6_addr_any(saddr);
801 int is_router = -1;
802 SKB_DR(reason);
803 u64 nonce = 0;
804 bool inc;
805
806 if (skb->len < sizeof(struct nd_msg))
807 return SKB_DROP_REASON_PKT_TOO_SMALL;
808
809 if (ipv6_addr_is_multicast(&msg->target)) {
810 ND_PRINTK(2, warn, "NS: multicast target address\n");
811 return reason;
812 }
813
814 /*
815 * RFC2461 7.1.1:
816 * DAD has to be destined for solicited node multicast address.
817 */
818 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
819 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
820 return reason;
821 }
822
823 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
824 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
825
826 if (ndopts.nd_opts_src_lladdr) {
827 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
828 if (!lladdr) {
829 ND_PRINTK(2, warn,
830 "NS: invalid link-layer address length\n");
831 return reason;
832 }
833
834 /* RFC2461 7.1.1:
835 * If the IP source address is the unspecified address,
836 * there MUST NOT be source link-layer address option
837 * in the message.
838 */
839 if (dad) {
840 ND_PRINTK(2, warn,
841 "NS: bad DAD packet (link-layer address option)\n");
842 return reason;
843 }
844 }
845 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
846 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
847
848 inc = ipv6_addr_is_multicast(daddr);
849
850 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
851 if (ifp) {
852have_ifp:
853 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
854 if (dad) {
855 if (nonce != 0 && ifp->dad_nonce == nonce) {
856 u8 *np = (u8 *)&nonce;
857 /* Matching nonce if looped back */
858 ND_PRINTK(2, notice,
859 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
860 ifp->idev->dev->name,
861 &ifp->addr, np);
862 goto out;
863 }
864 /*
865 * We are colliding with another node
866 * who is doing DAD
867 * so fail our DAD process
868 */
869 addrconf_dad_failure(skb, ifp);
870 return reason;
871 } else {
872 /*
873 * This is not a dad solicitation.
874 * If we are an optimistic node,
875 * we should respond.
876 * Otherwise, we should ignore it.
877 */
878 if (!(ifp->flags & IFA_F_OPTIMISTIC))
879 goto out;
880 }
881 }
882
883 idev = ifp->idev;
884 } else {
885 struct net *net = dev_net(dev);
886
887 /* perhaps an address on the master device */
888 if (netif_is_l3_slave(dev)) {
889 struct net_device *mdev;
890
891 mdev = netdev_master_upper_dev_get_rcu(dev);
892 if (mdev) {
893 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
894 if (ifp)
895 goto have_ifp;
896 }
897 }
898
899 idev = in6_dev_get(dev);
900 if (!idev) {
901 /* XXX: count this drop? */
902 return reason;
903 }
904
905 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
906 (READ_ONCE(idev->cnf.forwarding) &&
907 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) ||
908 READ_ONCE(idev->cnf.proxy_ndp)) &&
909 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
910 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
911 skb->pkt_type != PACKET_HOST &&
912 inc &&
913 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
914 /*
915 * for anycast or proxy,
916 * sender should delay its response
917 * by a random time between 0 and
918 * MAX_ANYCAST_DELAY_TIME seconds.
919 * (RFC2461) -- yoshfuji
920 */
921 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
922 if (n)
923 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
924 goto out;
925 }
926 } else {
927 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST);
928 goto out;
929 }
930 }
931
932 if (is_router < 0)
933 is_router = READ_ONCE(idev->cnf.forwarding);
934
935 if (dad) {
936 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
937 !!is_router, false, (ifp != NULL), true);
938 goto out;
939 }
940
941 if (inc)
942 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
943 else
944 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
945
946 /*
947 * update / create cache entry
948 * for the source address
949 */
950 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
951 !inc || lladdr || !dev->addr_len);
952 if (neigh)
953 ndisc_update(dev, neigh, lladdr, NUD_STALE,
954 NEIGH_UPDATE_F_WEAK_OVERRIDE|
955 NEIGH_UPDATE_F_OVERRIDE,
956 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
957 if (neigh || !dev->header_ops) {
958 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
959 true, (ifp != NULL && inc), inc);
960 if (neigh)
961 neigh_release(neigh);
962 reason = SKB_CONSUMED;
963 }
964
965out:
966 if (ifp)
967 in6_ifa_put(ifp);
968 else
969 in6_dev_put(idev);
970 return reason;
971}
972
973static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
974{
975 struct inet6_dev *idev = __in6_dev_get(dev);
976
977 switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
978 case 0: /* Don't accept untracked na (absent in neighbor cache) */
979 return 0;
980 case 1: /* Create new entries from na if currently untracked */
981 return 1;
982 case 2: /* Create new entries from untracked na only if saddr is in the
983 * same subnet as an address configured on the interface that
984 * received the na
985 */
986 return !!ipv6_chk_prefix(saddr, dev);
987 default:
988 return 0;
989 }
990}
991
992static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
993{
994 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
995 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
996 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
997 u8 *lladdr = NULL;
998 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
999 offsetof(struct nd_msg, opt));
1000 struct ndisc_options ndopts;
1001 struct net_device *dev = skb->dev;
1002 struct inet6_dev *idev = __in6_dev_get(dev);
1003 struct inet6_ifaddr *ifp;
1004 struct neighbour *neigh;
1005 SKB_DR(reason);
1006 u8 new_state;
1007
1008 if (skb->len < sizeof(struct nd_msg))
1009 return SKB_DROP_REASON_PKT_TOO_SMALL;
1010
1011 if (ipv6_addr_is_multicast(&msg->target)) {
1012 ND_PRINTK(2, warn, "NA: target address is multicast\n");
1013 return reason;
1014 }
1015
1016 if (ipv6_addr_is_multicast(daddr) &&
1017 msg->icmph.icmp6_solicited) {
1018 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
1019 return reason;
1020 }
1021
1022 /* For some 802.11 wireless deployments (and possibly other networks),
1023 * there will be a NA proxy and unsolicitd packets are attacks
1024 * and thus should not be accepted.
1025 * drop_unsolicited_na takes precedence over accept_untracked_na
1026 */
1027 if (!msg->icmph.icmp6_solicited && idev &&
1028 READ_ONCE(idev->cnf.drop_unsolicited_na))
1029 return reason;
1030
1031 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
1032 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1033
1034 if (ndopts.nd_opts_tgt_lladdr) {
1035 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1036 if (!lladdr) {
1037 ND_PRINTK(2, warn,
1038 "NA: invalid link-layer address length\n");
1039 return reason;
1040 }
1041 }
1042 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1043 if (ifp) {
1044 if (skb->pkt_type != PACKET_LOOPBACK
1045 && (ifp->flags & IFA_F_TENTATIVE)) {
1046 addrconf_dad_failure(skb, ifp);
1047 return reason;
1048 }
1049 /* What should we make now? The advertisement
1050 is invalid, but ndisc specs say nothing
1051 about it. It could be misconfiguration, or
1052 an smart proxy agent tries to help us :-)
1053
1054 We should not print the error if NA has been
1055 received from loopback - it is just our own
1056 unsolicited advertisement.
1057 */
1058 if (skb->pkt_type != PACKET_LOOPBACK)
1059 ND_PRINTK(1, warn,
1060 "NA: %pM advertised our address %pI6c on %s!\n",
1061 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1062 in6_ifa_put(ifp);
1063 return reason;
1064 }
1065
1066 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1067
1068 /* RFC 9131 updates original Neighbour Discovery RFC 4861.
1069 * NAs with Target LL Address option without a corresponding
1070 * entry in the neighbour cache can now create a STALE neighbour
1071 * cache entry on routers.
1072 *
1073 * entry accept fwding solicited behaviour
1074 * ------- ------ ------ --------- ----------------------
1075 * present X X 0 Set state to STALE
1076 * present X X 1 Set state to REACHABLE
1077 * absent 0 X X Do nothing
1078 * absent 1 0 X Do nothing
1079 * absent 1 1 X Add a new STALE entry
1080 *
1081 * Note that we don't do a (daddr == all-routers-mcast) check.
1082 */
1083 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1084 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) {
1085 if (accept_untracked_na(dev, saddr)) {
1086 neigh = neigh_create(&nd_tbl, &msg->target, dev);
1087 new_state = NUD_STALE;
1088 }
1089 }
1090
1091 if (neigh && !IS_ERR(neigh)) {
1092 u8 old_flags = neigh->flags;
1093 struct net *net = dev_net(dev);
1094
1095 if (READ_ONCE(neigh->nud_state) & NUD_FAILED)
1096 goto out;
1097
1098 /*
1099 * Don't update the neighbor cache entry on a proxy NA from
1100 * ourselves because either the proxied node is off link or it
1101 * has already sent a NA to us.
1102 */
1103 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1104 READ_ONCE(net->ipv6.devconf_all->forwarding) &&
1105 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
1106 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1107 /* XXX: idev->cnf.proxy_ndp */
1108 goto out;
1109 }
1110
1111 ndisc_update(dev, neigh, lladdr,
1112 new_state,
1113 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1114 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1115 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1116 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1117 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1118
1119 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1120 /*
1121 * Change: router to host
1122 */
1123 rt6_clean_tohost(dev_net(dev), saddr);
1124 }
1125 reason = SKB_CONSUMED;
1126out:
1127 neigh_release(neigh);
1128 }
1129 return reason;
1130}
1131
1132static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
1133{
1134 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1135 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1136 struct neighbour *neigh;
1137 struct inet6_dev *idev;
1138 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1139 struct ndisc_options ndopts;
1140 u8 *lladdr = NULL;
1141 SKB_DR(reason);
1142
1143 if (skb->len < sizeof(*rs_msg))
1144 return SKB_DROP_REASON_PKT_TOO_SMALL;
1145
1146 idev = __in6_dev_get(skb->dev);
1147 if (!idev) {
1148 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1149 return reason;
1150 }
1151
1152 /* Don't accept RS if we're not in router mode */
1153 if (!READ_ONCE(idev->cnf.forwarding))
1154 goto out;
1155
1156 /*
1157 * Don't update NCE if src = ::;
1158 * this implies that the source node has no ip address assigned yet.
1159 */
1160 if (ipv6_addr_any(saddr))
1161 goto out;
1162
1163 /* Parse ND options */
1164 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts))
1165 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1166
1167 if (ndopts.nd_opts_src_lladdr) {
1168 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1169 skb->dev);
1170 if (!lladdr)
1171 goto out;
1172 }
1173
1174 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1175 if (neigh) {
1176 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1177 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1178 NEIGH_UPDATE_F_OVERRIDE|
1179 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1180 NDISC_ROUTER_SOLICITATION, &ndopts);
1181 neigh_release(neigh);
1182 reason = SKB_CONSUMED;
1183 }
1184out:
1185 return reason;
1186}
1187
1188static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1189{
1190 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1191 struct sk_buff *skb;
1192 struct nlmsghdr *nlh;
1193 struct nduseroptmsg *ndmsg;
1194 struct net *net = dev_net(ra->dev);
1195 int err;
1196 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1197 + (opt->nd_opt_len << 3));
1198 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1199
1200 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1201 if (!skb) {
1202 err = -ENOBUFS;
1203 goto errout;
1204 }
1205
1206 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1207 if (!nlh) {
1208 goto nla_put_failure;
1209 }
1210
1211 ndmsg = nlmsg_data(nlh);
1212 ndmsg->nduseropt_family = AF_INET6;
1213 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1214 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1215 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1216 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1217
1218 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1219
1220 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1221 goto nla_put_failure;
1222 nlmsg_end(skb, nlh);
1223
1224 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1225 return;
1226
1227nla_put_failure:
1228 nlmsg_free(skb);
1229 err = -EMSGSIZE;
1230errout:
1231 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1232}
1233
1234static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
1235{
1236 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1237 bool send_ifinfo_notify = false;
1238 struct neighbour *neigh = NULL;
1239 struct ndisc_options ndopts;
1240 struct fib6_info *rt = NULL;
1241 struct inet6_dev *in6_dev;
1242 struct fib6_table *table;
1243 u32 defrtr_usr_metric;
1244 unsigned int pref = 0;
1245 __u32 old_if_flags;
1246 struct net *net;
1247 SKB_DR(reason);
1248 int lifetime;
1249 int optlen;
1250
1251 __u8 *opt = (__u8 *)(ra_msg + 1);
1252
1253 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1254 sizeof(struct ra_msg);
1255
1256 ND_PRINTK(2, info,
1257 "RA: %s, dev: %s\n",
1258 __func__, skb->dev->name);
1259 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1260 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1261 return reason;
1262 }
1263 if (optlen < 0)
1264 return SKB_DROP_REASON_PKT_TOO_SMALL;
1265
1266#ifdef CONFIG_IPV6_NDISC_NODETYPE
1267 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1268 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1269 return reason;
1270 }
1271#endif
1272
1273 in6_dev = __in6_dev_get(skb->dev);
1274 if (!in6_dev) {
1275 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1276 skb->dev->name);
1277 return reason;
1278 }
1279
1280 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
1281 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1282
1283 if (!ipv6_accept_ra(in6_dev)) {
1284 ND_PRINTK(2, info,
1285 "RA: %s, did not accept ra for dev: %s\n",
1286 __func__, skb->dev->name);
1287 goto skip_linkparms;
1288 }
1289
1290#ifdef CONFIG_IPV6_NDISC_NODETYPE
1291 /* skip link-specific parameters from interior routers */
1292 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1293 ND_PRINTK(2, info,
1294 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1295 __func__, skb->dev->name);
1296 goto skip_linkparms;
1297 }
1298#endif
1299
1300 if (in6_dev->if_flags & IF_RS_SENT) {
1301 /*
1302 * flag that an RA was received after an RS was sent
1303 * out on this interface.
1304 */
1305 in6_dev->if_flags |= IF_RA_RCVD;
1306 }
1307
1308 /*
1309 * Remember the managed/otherconf flags from most recently
1310 * received RA message (RFC 2462) -- yoshfuji
1311 */
1312 old_if_flags = in6_dev->if_flags;
1313 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1314 IF_RA_OTHERCONF)) |
1315 (ra_msg->icmph.icmp6_addrconf_managed ?
1316 IF_RA_MANAGED : 0) |
1317 (ra_msg->icmph.icmp6_addrconf_other ?
1318 IF_RA_OTHERCONF : 0);
1319
1320 if (old_if_flags != in6_dev->if_flags)
1321 send_ifinfo_notify = true;
1322
1323 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) {
1324 ND_PRINTK(2, info,
1325 "RA: %s, defrtr is false for dev: %s\n",
1326 __func__, skb->dev->name);
1327 goto skip_defrtr;
1328 }
1329
1330 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1331 if (lifetime != 0 &&
1332 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) {
1333 ND_PRINTK(2, info,
1334 "RA: router lifetime (%ds) is too short: %s\n",
1335 lifetime, skb->dev->name);
1336 goto skip_defrtr;
1337 }
1338
1339 /* Do not accept RA with source-addr found on local machine unless
1340 * accept_ra_from_local is set to true.
1341 */
1342 net = dev_net(in6_dev->dev);
1343 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1344 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1345 ND_PRINTK(2, info,
1346 "RA from local address detected on dev: %s: default router ignored\n",
1347 skb->dev->name);
1348 goto skip_defrtr;
1349 }
1350
1351#ifdef CONFIG_IPV6_ROUTER_PREF
1352 pref = ra_msg->icmph.icmp6_router_pref;
1353 /* 10b is handled as if it were 00b (medium) */
1354 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1355 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref))
1356 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1357#endif
1358 /* routes added from RAs do not use nexthop objects */
1359 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1360 if (rt) {
1361 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1362 rt->fib6_nh->fib_nh_dev, NULL,
1363 &ipv6_hdr(skb)->saddr);
1364 if (!neigh) {
1365 ND_PRINTK(0, err,
1366 "RA: %s got default router without neighbour\n",
1367 __func__);
1368 fib6_info_release(rt);
1369 return reason;
1370 }
1371 }
1372 /* Set default route metric as specified by user */
1373 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1374 /* delete the route if lifetime is 0 or if metric needs change */
1375 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1376 ip6_del_rt(net, rt, false);
1377 rt = NULL;
1378 }
1379
1380 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
1381 rt, lifetime, defrtr_usr_metric, skb->dev->name);
1382 if (!rt && lifetime) {
1383 ND_PRINTK(3, info, "RA: adding default router\n");
1384
1385 if (neigh)
1386 neigh_release(neigh);
1387
1388 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1389 skb->dev, pref, defrtr_usr_metric,
1390 lifetime);
1391 if (!rt) {
1392 ND_PRINTK(0, err,
1393 "RA: %s failed to add default route\n",
1394 __func__);
1395 return reason;
1396 }
1397
1398 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1399 rt->fib6_nh->fib_nh_dev, NULL,
1400 &ipv6_hdr(skb)->saddr);
1401 if (!neigh) {
1402 ND_PRINTK(0, err,
1403 "RA: %s got default router without neighbour\n",
1404 __func__);
1405 fib6_info_release(rt);
1406 return reason;
1407 }
1408 neigh->flags |= NTF_ROUTER;
1409 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1410 struct nl_info nlinfo = {
1411 .nl_net = net,
1412 };
1413 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1414 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
1415 }
1416
1417 if (rt) {
1418 table = rt->fib6_table;
1419 spin_lock_bh(&table->tb6_lock);
1420
1421 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1422 fib6_add_gc_list(rt);
1423
1424 spin_unlock_bh(&table->tb6_lock);
1425 }
1426 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 &&
1427 ra_msg->icmph.icmp6_hop_limit) {
1428 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <=
1429 ra_msg->icmph.icmp6_hop_limit) {
1430 WRITE_ONCE(in6_dev->cnf.hop_limit,
1431 ra_msg->icmph.icmp6_hop_limit);
1432 fib6_metric_set(rt, RTAX_HOPLIMIT,
1433 ra_msg->icmph.icmp6_hop_limit);
1434 } else {
1435 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1436 }
1437 }
1438
1439skip_defrtr:
1440
1441 /*
1442 * Update Reachable Time and Retrans Timer
1443 */
1444
1445 if (in6_dev->nd_parms) {
1446 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1447
1448 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1449 rtime = (rtime*HZ)/1000;
1450 if (rtime < HZ/100)
1451 rtime = HZ/100;
1452 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1453 in6_dev->tstamp = jiffies;
1454 send_ifinfo_notify = true;
1455 }
1456
1457 rtime = ntohl(ra_msg->reachable_time);
1458 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1459 rtime = (rtime*HZ)/1000;
1460
1461 if (rtime < HZ/10)
1462 rtime = HZ/10;
1463
1464 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1465 NEIGH_VAR_SET(in6_dev->nd_parms,
1466 BASE_REACHABLE_TIME, rtime);
1467 NEIGH_VAR_SET(in6_dev->nd_parms,
1468 GC_STALETIME, 3 * rtime);
1469 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1470 in6_dev->tstamp = jiffies;
1471 send_ifinfo_notify = true;
1472 }
1473 }
1474 }
1475
1476skip_linkparms:
1477
1478 /*
1479 * Process options.
1480 */
1481
1482 if (!neigh)
1483 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1484 skb->dev, 1);
1485 if (neigh) {
1486 u8 *lladdr = NULL;
1487 if (ndopts.nd_opts_src_lladdr) {
1488 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1489 skb->dev);
1490 if (!lladdr) {
1491 ND_PRINTK(2, warn,
1492 "RA: invalid link-layer address length\n");
1493 goto out;
1494 }
1495 }
1496 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1497 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1498 NEIGH_UPDATE_F_OVERRIDE|
1499 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1500 NEIGH_UPDATE_F_ISROUTER,
1501 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1502 reason = SKB_CONSUMED;
1503 }
1504
1505 if (!ipv6_accept_ra(in6_dev)) {
1506 ND_PRINTK(2, info,
1507 "RA: %s, accept_ra is false for dev: %s\n",
1508 __func__, skb->dev->name);
1509 goto out;
1510 }
1511
1512#ifdef CONFIG_IPV6_ROUTE_INFO
1513 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1514 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1515 in6_dev->dev, 0)) {
1516 ND_PRINTK(2, info,
1517 "RA from local address detected on dev: %s: router info ignored.\n",
1518 skb->dev->name);
1519 goto skip_routeinfo;
1520 }
1521
1522 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) {
1523 struct nd_opt_hdr *p;
1524 for (p = ndopts.nd_opts_ri;
1525 p;
1526 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1527 struct route_info *ri = (struct route_info *)p;
1528#ifdef CONFIG_IPV6_NDISC_NODETYPE
1529 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1530 ri->prefix_len == 0)
1531 continue;
1532#endif
1533 if (ri->prefix_len == 0 &&
1534 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr))
1535 continue;
1536 if (ri->lifetime != 0 &&
1537 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft))
1538 continue;
1539 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen))
1540 continue;
1541 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen))
1542 continue;
1543 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1544 &ipv6_hdr(skb)->saddr);
1545 }
1546 }
1547
1548skip_routeinfo:
1549#endif
1550
1551#ifdef CONFIG_IPV6_NDISC_NODETYPE
1552 /* skip link-specific ndopts from interior routers */
1553 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1554 ND_PRINTK(2, info,
1555 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1556 __func__, skb->dev->name);
1557 goto out;
1558 }
1559#endif
1560
1561 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) {
1562 struct nd_opt_hdr *p;
1563 for (p = ndopts.nd_opts_pi;
1564 p;
1565 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1566 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1567 (p->nd_opt_len) << 3,
1568 ndopts.nd_opts_src_lladdr != NULL);
1569 }
1570 }
1571
1572 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) {
1573 __be32 n;
1574 u32 mtu;
1575
1576 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1577 mtu = ntohl(n);
1578
1579 if (in6_dev->ra_mtu != mtu) {
1580 in6_dev->ra_mtu = mtu;
1581 send_ifinfo_notify = true;
1582 }
1583
1584 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1585 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1586 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) {
1587 WRITE_ONCE(in6_dev->cnf.mtu6, mtu);
1588 fib6_metric_set(rt, RTAX_MTU, mtu);
1589 rt6_mtu_change(skb->dev, mtu);
1590 }
1591 }
1592
1593 if (ndopts.nd_useropts) {
1594 struct nd_opt_hdr *p;
1595 for (p = ndopts.nd_useropts;
1596 p;
1597 p = ndisc_next_useropt(skb->dev, p,
1598 ndopts.nd_useropts_end)) {
1599 ndisc_ra_useropt(skb, p);
1600 }
1601 }
1602
1603 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1604 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1605 }
1606out:
1607 /* Send a notify if RA changed managed/otherconf flags or
1608 * timer settings or ra_mtu value
1609 */
1610 if (send_ifinfo_notify)
1611 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1612
1613 fib6_info_release(rt);
1614 if (neigh)
1615 neigh_release(neigh);
1616 return reason;
1617}
1618
1619static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
1620{
1621 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1622 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1623 offsetof(struct rd_msg, opt));
1624 struct ndisc_options ndopts;
1625 SKB_DR(reason);
1626 u8 *hdr;
1627
1628#ifdef CONFIG_IPV6_NDISC_NODETYPE
1629 switch (skb->ndisc_nodetype) {
1630 case NDISC_NODETYPE_HOST:
1631 case NDISC_NODETYPE_NODEFAULT:
1632 ND_PRINTK(2, warn,
1633 "Redirect: from host or unauthorized router\n");
1634 return reason;
1635 }
1636#endif
1637
1638 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1639 ND_PRINTK(2, warn,
1640 "Redirect: source address is not link-local\n");
1641 return reason;
1642 }
1643
1644 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1645 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1646
1647 if (!ndopts.nd_opts_rh) {
1648 ip6_redirect_no_header(skb, dev_net(skb->dev),
1649 skb->dev->ifindex);
1650 return reason;
1651 }
1652
1653 hdr = (u8 *)ndopts.nd_opts_rh;
1654 hdr += 8;
1655 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1656 return SKB_DROP_REASON_PKT_TOO_SMALL;
1657
1658 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1659}
1660
1661static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1662 struct sk_buff *orig_skb,
1663 int rd_len)
1664{
1665 u8 *opt = skb_put(skb, rd_len);
1666
1667 memset(opt, 0, 8);
1668 *(opt++) = ND_OPT_REDIRECT_HDR;
1669 *(opt++) = (rd_len >> 3);
1670 opt += 6;
1671
1672 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1673 rd_len - 8);
1674}
1675
1676void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1677{
1678 struct net_device *dev = skb->dev;
1679 struct net *net = dev_net(dev);
1680 struct sock *sk = net->ipv6.ndisc_sk;
1681 int optlen = 0;
1682 struct inet_peer *peer;
1683 struct sk_buff *buff;
1684 struct rd_msg *msg;
1685 struct in6_addr saddr_buf;
1686 struct rt6_info *rt;
1687 struct dst_entry *dst;
1688 struct flowi6 fl6;
1689 int rd_len;
1690 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1691 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1692 bool ret;
1693
1694 if (netif_is_l3_master(skb->dev)) {
1695 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1696 if (!dev)
1697 return;
1698 }
1699
1700 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1701 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1702 dev->name);
1703 return;
1704 }
1705
1706 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1707 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1708 ND_PRINTK(2, warn,
1709 "Redirect: target address is not link-local unicast\n");
1710 return;
1711 }
1712
1713 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1714 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1715
1716 dst = ip6_route_output(net, NULL, &fl6);
1717 if (dst->error) {
1718 dst_release(dst);
1719 return;
1720 }
1721 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1722 if (IS_ERR(dst))
1723 return;
1724
1725 rt = dst_rt6_info(dst);
1726
1727 if (rt->rt6i_flags & RTF_GATEWAY) {
1728 ND_PRINTK(2, warn,
1729 "Redirect: destination is not a neighbour\n");
1730 goto release;
1731 }
1732 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1733 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1734 if (peer)
1735 inet_putpeer(peer);
1736 if (!ret)
1737 goto release;
1738
1739 if (dev->addr_len) {
1740 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1741 if (!neigh) {
1742 ND_PRINTK(2, warn,
1743 "Redirect: no neigh for target address\n");
1744 goto release;
1745 }
1746
1747 read_lock_bh(&neigh->lock);
1748 if (neigh->nud_state & NUD_VALID) {
1749 memcpy(ha_buf, neigh->ha, dev->addr_len);
1750 read_unlock_bh(&neigh->lock);
1751 ha = ha_buf;
1752 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1753 ops_data_buf,
1754 &ops_data);
1755 } else
1756 read_unlock_bh(&neigh->lock);
1757
1758 neigh_release(neigh);
1759 }
1760
1761 rd_len = min_t(unsigned int,
1762 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1763 skb->len + 8);
1764 rd_len &= ~0x7;
1765 optlen += rd_len;
1766
1767 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1768 if (!buff)
1769 goto release;
1770
1771 msg = skb_put(buff, sizeof(*msg));
1772 *msg = (struct rd_msg) {
1773 .icmph = {
1774 .icmp6_type = NDISC_REDIRECT,
1775 },
1776 .target = *target,
1777 .dest = ipv6_hdr(skb)->daddr,
1778 };
1779
1780 /*
1781 * include target_address option
1782 */
1783
1784 if (ha)
1785 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1786
1787 /*
1788 * build redirect option and copy skb over to the new packet.
1789 */
1790
1791 if (rd_len)
1792 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1793
1794 skb_dst_set(buff, dst);
1795 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1796 return;
1797
1798release:
1799 dst_release(dst);
1800}
1801
1802static void pndisc_redo(struct sk_buff *skb)
1803{
1804 enum skb_drop_reason reason = ndisc_recv_ns(skb);
1805
1806 kfree_skb_reason(skb, reason);
1807}
1808
1809static int ndisc_is_multicast(const void *pkey)
1810{
1811 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1812}
1813
1814static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1815{
1816 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1817
1818 if (!idev)
1819 return true;
1820 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1821 READ_ONCE(idev->cnf.suppress_frag_ndisc)) {
1822 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1823 return true;
1824 }
1825 return false;
1826}
1827
1828enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
1829{
1830 struct nd_msg *msg;
1831 SKB_DR(reason);
1832
1833 if (ndisc_suppress_frag_ndisc(skb))
1834 return SKB_DROP_REASON_IPV6_NDISC_FRAG;
1835
1836 if (skb_linearize(skb))
1837 return SKB_DROP_REASON_NOMEM;
1838
1839 msg = (struct nd_msg *)skb_transport_header(skb);
1840
1841 __skb_push(skb, skb->data - skb_transport_header(skb));
1842
1843 if (ipv6_hdr(skb)->hop_limit != 255) {
1844 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1845 ipv6_hdr(skb)->hop_limit);
1846 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT;
1847 }
1848
1849 if (msg->icmph.icmp6_code != 0) {
1850 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1851 msg->icmph.icmp6_code);
1852 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE;
1853 }
1854
1855 switch (msg->icmph.icmp6_type) {
1856 case NDISC_NEIGHBOUR_SOLICITATION:
1857 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1858 reason = ndisc_recv_ns(skb);
1859 break;
1860
1861 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1862 reason = ndisc_recv_na(skb);
1863 break;
1864
1865 case NDISC_ROUTER_SOLICITATION:
1866 reason = ndisc_recv_rs(skb);
1867 break;
1868
1869 case NDISC_ROUTER_ADVERTISEMENT:
1870 reason = ndisc_router_discovery(skb);
1871 break;
1872
1873 case NDISC_REDIRECT:
1874 reason = ndisc_redirect_rcv(skb);
1875 break;
1876 }
1877
1878 return reason;
1879}
1880
1881static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1882{
1883 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1884 struct netdev_notifier_change_info *change_info;
1885 struct net *net = dev_net(dev);
1886 struct inet6_dev *idev;
1887 bool evict_nocarrier;
1888
1889 switch (event) {
1890 case NETDEV_CHANGEADDR:
1891 neigh_changeaddr(&nd_tbl, dev);
1892 fib6_run_gc(0, net, false);
1893 fallthrough;
1894 case NETDEV_UP:
1895 idev = in6_dev_get(dev);
1896 if (!idev)
1897 break;
1898 if (READ_ONCE(idev->cnf.ndisc_notify) ||
1899 READ_ONCE(net->ipv6.devconf_all->ndisc_notify))
1900 ndisc_send_unsol_na(dev);
1901 in6_dev_put(idev);
1902 break;
1903 case NETDEV_CHANGE:
1904 idev = in6_dev_get(dev);
1905 if (!idev)
1906 evict_nocarrier = true;
1907 else {
1908 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) &&
1909 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier);
1910 in6_dev_put(idev);
1911 }
1912
1913 change_info = ptr;
1914 if (change_info->flags_changed & IFF_NOARP)
1915 neigh_changeaddr(&nd_tbl, dev);
1916 if (evict_nocarrier && !netif_carrier_ok(dev))
1917 neigh_carrier_down(&nd_tbl, dev);
1918 break;
1919 case NETDEV_DOWN:
1920 neigh_ifdown(&nd_tbl, dev);
1921 fib6_run_gc(0, net, false);
1922 break;
1923 case NETDEV_NOTIFY_PEERS:
1924 ndisc_send_unsol_na(dev);
1925 break;
1926 default:
1927 break;
1928 }
1929
1930 return NOTIFY_DONE;
1931}
1932
1933static struct notifier_block ndisc_netdev_notifier = {
1934 .notifier_call = ndisc_netdev_event,
1935 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1936};
1937
1938#ifdef CONFIG_SYSCTL
1939static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1940 const char *func, const char *dev_name)
1941{
1942 static char warncomm[TASK_COMM_LEN];
1943 static int warned;
1944 if (strcmp(warncomm, current->comm) && warned < 5) {
1945 strcpy(warncomm, current->comm);
1946 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1947 warncomm, func,
1948 dev_name, ctl->procname,
1949 dev_name, ctl->procname);
1950 warned++;
1951 }
1952}
1953
1954int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1955 size_t *lenp, loff_t *ppos)
1956{
1957 struct net_device *dev = ctl->extra1;
1958 struct inet6_dev *idev;
1959 int ret;
1960
1961 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1962 (strcmp(ctl->procname, "base_reachable_time") == 0))
1963 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1964
1965 if (strcmp(ctl->procname, "retrans_time") == 0)
1966 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1967
1968 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1969 ret = neigh_proc_dointvec_jiffies(ctl, write,
1970 buffer, lenp, ppos);
1971
1972 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1973 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1974 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1975 buffer, lenp, ppos);
1976 else
1977 ret = -1;
1978
1979 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1980 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1981 idev->nd_parms->reachable_time =
1982 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1983 WRITE_ONCE(idev->tstamp, jiffies);
1984 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1985 in6_dev_put(idev);
1986 }
1987 return ret;
1988}
1989
1990
1991#endif
1992
1993static int __net_init ndisc_net_init(struct net *net)
1994{
1995 struct ipv6_pinfo *np;
1996 struct sock *sk;
1997 int err;
1998
1999 err = inet_ctl_sock_create(&sk, PF_INET6,
2000 SOCK_RAW, IPPROTO_ICMPV6, net);
2001 if (err < 0) {
2002 ND_PRINTK(0, err,
2003 "NDISC: Failed to initialize the control socket (err %d)\n",
2004 err);
2005 return err;
2006 }
2007
2008 net->ipv6.ndisc_sk = sk;
2009
2010 np = inet6_sk(sk);
2011 np->hop_limit = 255;
2012 /* Do not loopback ndisc messages */
2013 inet6_clear_bit(MC6_LOOP, sk);
2014
2015 return 0;
2016}
2017
2018static void __net_exit ndisc_net_exit(struct net *net)
2019{
2020 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
2021}
2022
2023static struct pernet_operations ndisc_net_ops = {
2024 .init = ndisc_net_init,
2025 .exit = ndisc_net_exit,
2026};
2027
2028int __init ndisc_init(void)
2029{
2030 int err;
2031
2032 err = register_pernet_subsys(&ndisc_net_ops);
2033 if (err)
2034 return err;
2035 /*
2036 * Initialize the neighbour table
2037 */
2038 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
2039
2040#ifdef CONFIG_SYSCTL
2041 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
2042 ndisc_ifinfo_sysctl_change);
2043 if (err)
2044 goto out_unregister_pernet;
2045out:
2046#endif
2047 return err;
2048
2049#ifdef CONFIG_SYSCTL
2050out_unregister_pernet:
2051 unregister_pernet_subsys(&ndisc_net_ops);
2052 goto out;
2053#endif
2054}
2055
2056int __init ndisc_late_init(void)
2057{
2058 return register_netdevice_notifier(&ndisc_netdev_notifier);
2059}
2060
2061void ndisc_late_cleanup(void)
2062{
2063 unregister_netdevice_notifier(&ndisc_netdev_notifier);
2064}
2065
2066void ndisc_cleanup(void)
2067{
2068#ifdef CONFIG_SYSCTL
2069 neigh_sysctl_unregister(&nd_tbl.parms);
2070#endif
2071 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
2072 unregister_pernet_subsys(&ndisc_net_ops);
2073}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Neighbour Discovery for IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Mike Shaver <shaver@ingenia.com>
9 */
10
11/*
12 * Changes:
13 *
14 * Alexey I. Froloff : RFC6106 (DNSSL) support
15 * Pierre Ynard : export userland ND options
16 * through netlink (RDNSS support)
17 * Lars Fenneberg : fixed MTU setting on receipt
18 * of an RA.
19 * Janos Farkas : kmalloc failure checks
20 * Alexey Kuznetsov : state machine reworked
21 * and moved to net/core.
22 * Pekka Savola : RFC2461 validation
23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
24 */
25
26#define pr_fmt(fmt) "ICMPv6: " fmt
27
28#include <linux/module.h>
29#include <linux/errno.h>
30#include <linux/types.h>
31#include <linux/socket.h>
32#include <linux/sockios.h>
33#include <linux/sched.h>
34#include <linux/net.h>
35#include <linux/in6.h>
36#include <linux/route.h>
37#include <linux/init.h>
38#include <linux/rcupdate.h>
39#include <linux/slab.h>
40#ifdef CONFIG_SYSCTL
41#include <linux/sysctl.h>
42#endif
43
44#include <linux/if_addr.h>
45#include <linux/if_ether.h>
46#include <linux/if_arp.h>
47#include <linux/ipv6.h>
48#include <linux/icmpv6.h>
49#include <linux/jhash.h>
50
51#include <net/sock.h>
52#include <net/snmp.h>
53
54#include <net/ipv6.h>
55#include <net/protocol.h>
56#include <net/ndisc.h>
57#include <net/ip6_route.h>
58#include <net/addrconf.h>
59#include <net/icmp.h>
60
61#include <net/netlink.h>
62#include <linux/rtnetlink.h>
63
64#include <net/flow.h>
65#include <net/ip6_checksum.h>
66#include <net/inet_common.h>
67#include <linux/proc_fs.h>
68
69#include <linux/netfilter.h>
70#include <linux/netfilter_ipv6.h>
71
72static u32 ndisc_hash(const void *pkey,
73 const struct net_device *dev,
74 __u32 *hash_rnd);
75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
76static bool ndisc_allow_add(const struct net_device *dev,
77 struct netlink_ext_ack *extack);
78static int ndisc_constructor(struct neighbour *neigh);
79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
81static int pndisc_constructor(struct pneigh_entry *n);
82static void pndisc_destructor(struct pneigh_entry *n);
83static void pndisc_redo(struct sk_buff *skb);
84static int ndisc_is_multicast(const void *pkey);
85
86static const struct neigh_ops ndisc_generic_ops = {
87 .family = AF_INET6,
88 .solicit = ndisc_solicit,
89 .error_report = ndisc_error_report,
90 .output = neigh_resolve_output,
91 .connected_output = neigh_connected_output,
92};
93
94static const struct neigh_ops ndisc_hh_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_resolve_output,
100};
101
102
103static const struct neigh_ops ndisc_direct_ops = {
104 .family = AF_INET6,
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
107};
108
109struct neigh_table nd_tbl = {
110 .family = AF_INET6,
111 .key_len = sizeof(struct in6_addr),
112 .protocol = cpu_to_be16(ETH_P_IPV6),
113 .hash = ndisc_hash,
114 .key_eq = ndisc_key_eq,
115 .constructor = ndisc_constructor,
116 .pconstructor = pndisc_constructor,
117 .pdestructor = pndisc_destructor,
118 .proxy_redo = pndisc_redo,
119 .is_multicast = ndisc_is_multicast,
120 .allow_add = ndisc_allow_add,
121 .id = "ndisc_cache",
122 .parms = {
123 .tbl = &nd_tbl,
124 .reachable_time = ND_REACHABLE_TIME,
125 .data = {
126 [NEIGH_VAR_MCAST_PROBES] = 3,
127 [NEIGH_VAR_UCAST_PROBES] = 3,
128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
131 [NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ,
132 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
133 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
134 [NEIGH_VAR_PROXY_QLEN] = 64,
135 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
136 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
137 },
138 },
139 .gc_interval = 30 * HZ,
140 .gc_thresh1 = 128,
141 .gc_thresh2 = 512,
142 .gc_thresh3 = 1024,
143};
144EXPORT_SYMBOL_GPL(nd_tbl);
145
146void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data,
147 int data_len, int pad)
148{
149 int space = __ndisc_opt_addr_space(data_len, pad);
150 u8 *opt = skb_put(skb, space);
151
152 opt[0] = type;
153 opt[1] = space>>3;
154
155 memset(opt + 2, 0, pad);
156 opt += pad;
157 space -= pad;
158
159 memcpy(opt+2, data, data_len);
160 data_len += 2;
161 opt += data_len;
162 space -= data_len;
163 if (space > 0)
164 memset(opt, 0, space);
165}
166EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
167
168static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
169 const void *data, u8 icmp6_type)
170{
171 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
172 ndisc_addr_option_pad(skb->dev->type));
173 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
174}
175
176static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
177 void *ha,
178 const u8 *ops_data)
179{
180 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
181 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
182}
183
184static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
185 struct nd_opt_hdr *end)
186{
187 int type;
188 if (!cur || !end || cur >= end)
189 return NULL;
190 type = cur->nd_opt_type;
191 do {
192 cur = ((void *)cur) + (cur->nd_opt_len << 3);
193 } while (cur < end && cur->nd_opt_type != type);
194 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
195}
196
197static inline int ndisc_is_useropt(const struct net_device *dev,
198 struct nd_opt_hdr *opt)
199{
200 return opt->nd_opt_type == ND_OPT_RDNSS ||
201 opt->nd_opt_type == ND_OPT_DNSSL ||
202 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
203 opt->nd_opt_type == ND_OPT_PREF64 ||
204 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
205}
206
207static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
208 struct nd_opt_hdr *cur,
209 struct nd_opt_hdr *end)
210{
211 if (!cur || !end || cur >= end)
212 return NULL;
213 do {
214 cur = ((void *)cur) + (cur->nd_opt_len << 3);
215 } while (cur < end && !ndisc_is_useropt(dev, cur));
216 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
217}
218
219struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
220 u8 *opt, int opt_len,
221 struct ndisc_options *ndopts)
222{
223 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
224
225 if (!nd_opt || opt_len < 0 || !ndopts)
226 return NULL;
227 memset(ndopts, 0, sizeof(*ndopts));
228 while (opt_len) {
229 int l;
230 if (opt_len < sizeof(struct nd_opt_hdr))
231 return NULL;
232 l = nd_opt->nd_opt_len << 3;
233 if (opt_len < l || l == 0)
234 return NULL;
235 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
236 goto next_opt;
237 switch (nd_opt->nd_opt_type) {
238 case ND_OPT_SOURCE_LL_ADDR:
239 case ND_OPT_TARGET_LL_ADDR:
240 case ND_OPT_MTU:
241 case ND_OPT_NONCE:
242 case ND_OPT_REDIRECT_HDR:
243 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
244 ND_PRINTK(2, warn,
245 "%s: duplicated ND6 option found: type=%d\n",
246 __func__, nd_opt->nd_opt_type);
247 } else {
248 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
249 }
250 break;
251 case ND_OPT_PREFIX_INFO:
252 ndopts->nd_opts_pi_end = nd_opt;
253 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
254 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
255 break;
256#ifdef CONFIG_IPV6_ROUTE_INFO
257 case ND_OPT_ROUTE_INFO:
258 ndopts->nd_opts_ri_end = nd_opt;
259 if (!ndopts->nd_opts_ri)
260 ndopts->nd_opts_ri = nd_opt;
261 break;
262#endif
263 default:
264 if (ndisc_is_useropt(dev, nd_opt)) {
265 ndopts->nd_useropts_end = nd_opt;
266 if (!ndopts->nd_useropts)
267 ndopts->nd_useropts = nd_opt;
268 } else {
269 /*
270 * Unknown options must be silently ignored,
271 * to accommodate future extension to the
272 * protocol.
273 */
274 ND_PRINTK(2, notice,
275 "%s: ignored unsupported option; type=%d, len=%d\n",
276 __func__,
277 nd_opt->nd_opt_type,
278 nd_opt->nd_opt_len);
279 }
280 }
281next_opt:
282 opt_len -= l;
283 nd_opt = ((void *)nd_opt) + l;
284 }
285 return ndopts;
286}
287
288int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
289{
290 switch (dev->type) {
291 case ARPHRD_ETHER:
292 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
293 case ARPHRD_FDDI:
294 ipv6_eth_mc_map(addr, buf);
295 return 0;
296 case ARPHRD_ARCNET:
297 ipv6_arcnet_mc_map(addr, buf);
298 return 0;
299 case ARPHRD_INFINIBAND:
300 ipv6_ib_mc_map(addr, dev->broadcast, buf);
301 return 0;
302 case ARPHRD_IPGRE:
303 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
304 default:
305 if (dir) {
306 memcpy(buf, dev->broadcast, dev->addr_len);
307 return 0;
308 }
309 }
310 return -EINVAL;
311}
312EXPORT_SYMBOL(ndisc_mc_map);
313
314static u32 ndisc_hash(const void *pkey,
315 const struct net_device *dev,
316 __u32 *hash_rnd)
317{
318 return ndisc_hashfn(pkey, dev, hash_rnd);
319}
320
321static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
322{
323 return neigh_key_eq128(n, pkey);
324}
325
326static int ndisc_constructor(struct neighbour *neigh)
327{
328 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
329 struct net_device *dev = neigh->dev;
330 struct inet6_dev *in6_dev;
331 struct neigh_parms *parms;
332 bool is_multicast = ipv6_addr_is_multicast(addr);
333
334 in6_dev = in6_dev_get(dev);
335 if (!in6_dev) {
336 return -EINVAL;
337 }
338
339 parms = in6_dev->nd_parms;
340 __neigh_parms_put(neigh->parms);
341 neigh->parms = neigh_parms_clone(parms);
342
343 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
344 if (!dev->header_ops) {
345 neigh->nud_state = NUD_NOARP;
346 neigh->ops = &ndisc_direct_ops;
347 neigh->output = neigh_direct_output;
348 } else {
349 if (is_multicast) {
350 neigh->nud_state = NUD_NOARP;
351 ndisc_mc_map(addr, neigh->ha, dev, 1);
352 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
353 neigh->nud_state = NUD_NOARP;
354 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
355 if (dev->flags&IFF_LOOPBACK)
356 neigh->type = RTN_LOCAL;
357 } else if (dev->flags&IFF_POINTOPOINT) {
358 neigh->nud_state = NUD_NOARP;
359 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
360 }
361 if (dev->header_ops->cache)
362 neigh->ops = &ndisc_hh_ops;
363 else
364 neigh->ops = &ndisc_generic_ops;
365 if (neigh->nud_state&NUD_VALID)
366 neigh->output = neigh->ops->connected_output;
367 else
368 neigh->output = neigh->ops->output;
369 }
370 in6_dev_put(in6_dev);
371 return 0;
372}
373
374static int pndisc_constructor(struct pneigh_entry *n)
375{
376 struct in6_addr *addr = (struct in6_addr *)&n->key;
377 struct in6_addr maddr;
378 struct net_device *dev = n->dev;
379
380 if (!dev || !__in6_dev_get(dev))
381 return -EINVAL;
382 addrconf_addr_solict_mult(addr, &maddr);
383 ipv6_dev_mc_inc(dev, &maddr);
384 return 0;
385}
386
387static void pndisc_destructor(struct pneigh_entry *n)
388{
389 struct in6_addr *addr = (struct in6_addr *)&n->key;
390 struct in6_addr maddr;
391 struct net_device *dev = n->dev;
392
393 if (!dev || !__in6_dev_get(dev))
394 return;
395 addrconf_addr_solict_mult(addr, &maddr);
396 ipv6_dev_mc_dec(dev, &maddr);
397}
398
399/* called with rtnl held */
400static bool ndisc_allow_add(const struct net_device *dev,
401 struct netlink_ext_ack *extack)
402{
403 struct inet6_dev *idev = __in6_dev_get(dev);
404
405 if (!idev || idev->cnf.disable_ipv6) {
406 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
407 return false;
408 }
409
410 return true;
411}
412
413static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
414 int len)
415{
416 int hlen = LL_RESERVED_SPACE(dev);
417 int tlen = dev->needed_tailroom;
418 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
419 struct sk_buff *skb;
420
421 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
422 if (!skb) {
423 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
424 __func__);
425 return NULL;
426 }
427
428 skb->protocol = htons(ETH_P_IPV6);
429 skb->dev = dev;
430
431 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
432 skb_reset_transport_header(skb);
433
434 /* Manually assign socket ownership as we avoid calling
435 * sock_alloc_send_pskb() to bypass wmem buffer limits
436 */
437 skb_set_owner_w(skb, sk);
438
439 return skb;
440}
441
442static void ip6_nd_hdr(struct sk_buff *skb,
443 const struct in6_addr *saddr,
444 const struct in6_addr *daddr,
445 int hop_limit, int len)
446{
447 struct ipv6hdr *hdr;
448 struct inet6_dev *idev;
449 unsigned tclass;
450
451 rcu_read_lock();
452 idev = __in6_dev_get(skb->dev);
453 tclass = idev ? idev->cnf.ndisc_tclass : 0;
454 rcu_read_unlock();
455
456 skb_push(skb, sizeof(*hdr));
457 skb_reset_network_header(skb);
458 hdr = ipv6_hdr(skb);
459
460 ip6_flow_hdr(hdr, tclass, 0);
461
462 hdr->payload_len = htons(len);
463 hdr->nexthdr = IPPROTO_ICMPV6;
464 hdr->hop_limit = hop_limit;
465
466 hdr->saddr = *saddr;
467 hdr->daddr = *daddr;
468}
469
470void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
471 const struct in6_addr *saddr)
472{
473 struct dst_entry *dst = skb_dst(skb);
474 struct net *net = dev_net(skb->dev);
475 struct sock *sk = net->ipv6.ndisc_sk;
476 struct inet6_dev *idev;
477 int err;
478 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
479 u8 type;
480
481 type = icmp6h->icmp6_type;
482
483 if (!dst) {
484 struct flowi6 fl6;
485 int oif = skb->dev->ifindex;
486
487 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
488 dst = icmp6_dst_alloc(skb->dev, &fl6);
489 if (IS_ERR(dst)) {
490 kfree_skb(skb);
491 return;
492 }
493
494 skb_dst_set(skb, dst);
495 }
496
497 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
498 IPPROTO_ICMPV6,
499 csum_partial(icmp6h,
500 skb->len, 0));
501
502 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
503
504 rcu_read_lock();
505 idev = __in6_dev_get(dst->dev);
506 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
507
508 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
509 net, sk, skb, NULL, dst->dev,
510 dst_output);
511 if (!err) {
512 ICMP6MSGOUT_INC_STATS(net, idev, type);
513 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
514 }
515
516 rcu_read_unlock();
517}
518EXPORT_SYMBOL(ndisc_send_skb);
519
520void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
521 const struct in6_addr *solicited_addr,
522 bool router, bool solicited, bool override, bool inc_opt)
523{
524 struct sk_buff *skb;
525 struct in6_addr tmpaddr;
526 struct inet6_ifaddr *ifp;
527 const struct in6_addr *src_addr;
528 struct nd_msg *msg;
529 int optlen = 0;
530
531 /* for anycast or proxy, solicited_addr != src_addr */
532 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
533 if (ifp) {
534 src_addr = solicited_addr;
535 if (ifp->flags & IFA_F_OPTIMISTIC)
536 override = false;
537 inc_opt |= ifp->idev->cnf.force_tllao;
538 in6_ifa_put(ifp);
539 } else {
540 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
541 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
542 &tmpaddr))
543 return;
544 src_addr = &tmpaddr;
545 }
546
547 if (!dev->addr_len)
548 inc_opt = false;
549 if (inc_opt)
550 optlen += ndisc_opt_addr_space(dev,
551 NDISC_NEIGHBOUR_ADVERTISEMENT);
552
553 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
554 if (!skb)
555 return;
556
557 msg = skb_put(skb, sizeof(*msg));
558 *msg = (struct nd_msg) {
559 .icmph = {
560 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
561 .icmp6_router = router,
562 .icmp6_solicited = solicited,
563 .icmp6_override = override,
564 },
565 .target = *solicited_addr,
566 };
567
568 if (inc_opt)
569 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
570 dev->dev_addr,
571 NDISC_NEIGHBOUR_ADVERTISEMENT);
572
573 ndisc_send_skb(skb, daddr, src_addr);
574}
575
576static void ndisc_send_unsol_na(struct net_device *dev)
577{
578 struct inet6_dev *idev;
579 struct inet6_ifaddr *ifa;
580
581 idev = in6_dev_get(dev);
582 if (!idev)
583 return;
584
585 read_lock_bh(&idev->lock);
586 list_for_each_entry(ifa, &idev->addr_list, if_list) {
587 /* skip tentative addresses until dad completes */
588 if (ifa->flags & IFA_F_TENTATIVE &&
589 !(ifa->flags & IFA_F_OPTIMISTIC))
590 continue;
591
592 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
593 /*router=*/ !!idev->cnf.forwarding,
594 /*solicited=*/ false, /*override=*/ true,
595 /*inc_opt=*/ true);
596 }
597 read_unlock_bh(&idev->lock);
598
599 in6_dev_put(idev);
600}
601
602struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
603 const struct in6_addr *saddr, u64 nonce)
604{
605 int inc_opt = dev->addr_len;
606 struct sk_buff *skb;
607 struct nd_msg *msg;
608 int optlen = 0;
609
610 if (!saddr)
611 return NULL;
612
613 if (ipv6_addr_any(saddr))
614 inc_opt = false;
615 if (inc_opt)
616 optlen += ndisc_opt_addr_space(dev,
617 NDISC_NEIGHBOUR_SOLICITATION);
618 if (nonce != 0)
619 optlen += 8;
620
621 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
622 if (!skb)
623 return NULL;
624
625 msg = skb_put(skb, sizeof(*msg));
626 *msg = (struct nd_msg) {
627 .icmph = {
628 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
629 },
630 .target = *solicit,
631 };
632
633 if (inc_opt)
634 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
635 dev->dev_addr,
636 NDISC_NEIGHBOUR_SOLICITATION);
637 if (nonce != 0) {
638 u8 *opt = skb_put(skb, 8);
639
640 opt[0] = ND_OPT_NONCE;
641 opt[1] = 8 >> 3;
642 memcpy(opt + 2, &nonce, 6);
643 }
644
645 return skb;
646}
647EXPORT_SYMBOL(ndisc_ns_create);
648
649void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
650 const struct in6_addr *daddr, const struct in6_addr *saddr,
651 u64 nonce)
652{
653 struct in6_addr addr_buf;
654 struct sk_buff *skb;
655
656 if (!saddr) {
657 if (ipv6_get_lladdr(dev, &addr_buf,
658 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
659 return;
660 saddr = &addr_buf;
661 }
662
663 skb = ndisc_ns_create(dev, solicit, saddr, nonce);
664
665 if (skb)
666 ndisc_send_skb(skb, daddr, saddr);
667}
668
669void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
670 const struct in6_addr *daddr)
671{
672 struct sk_buff *skb;
673 struct rs_msg *msg;
674 int send_sllao = dev->addr_len;
675 int optlen = 0;
676
677#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
678 /*
679 * According to section 2.2 of RFC 4429, we must not
680 * send router solicitations with a sllao from
681 * optimistic addresses, but we may send the solicitation
682 * if we don't include the sllao. So here we check
683 * if our address is optimistic, and if so, we
684 * suppress the inclusion of the sllao.
685 */
686 if (send_sllao) {
687 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
688 dev, 1);
689 if (ifp) {
690 if (ifp->flags & IFA_F_OPTIMISTIC) {
691 send_sllao = 0;
692 }
693 in6_ifa_put(ifp);
694 } else {
695 send_sllao = 0;
696 }
697 }
698#endif
699 if (send_sllao)
700 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
701
702 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
703 if (!skb)
704 return;
705
706 msg = skb_put(skb, sizeof(*msg));
707 *msg = (struct rs_msg) {
708 .icmph = {
709 .icmp6_type = NDISC_ROUTER_SOLICITATION,
710 },
711 };
712
713 if (send_sllao)
714 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
715 dev->dev_addr,
716 NDISC_ROUTER_SOLICITATION);
717
718 ndisc_send_skb(skb, daddr, saddr);
719}
720
721
722static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
723{
724 /*
725 * "The sender MUST return an ICMP
726 * destination unreachable"
727 */
728 dst_link_failure(skb);
729 kfree_skb(skb);
730}
731
732/* Called with locked neigh: either read or both */
733
734static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
735{
736 struct in6_addr *saddr = NULL;
737 struct in6_addr mcaddr;
738 struct net_device *dev = neigh->dev;
739 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
740 int probes = atomic_read(&neigh->probes);
741
742 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
743 dev, false, 1,
744 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
745 saddr = &ipv6_hdr(skb)->saddr;
746 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
747 if (probes < 0) {
748 if (!(neigh->nud_state & NUD_VALID)) {
749 ND_PRINTK(1, dbg,
750 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
751 __func__, target);
752 }
753 ndisc_send_ns(dev, target, target, saddr, 0);
754 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
755 neigh_app_ns(neigh);
756 } else {
757 addrconf_addr_solict_mult(target, &mcaddr);
758 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
759 }
760}
761
762static int pndisc_is_router(const void *pkey,
763 struct net_device *dev)
764{
765 struct pneigh_entry *n;
766 int ret = -1;
767
768 read_lock_bh(&nd_tbl.lock);
769 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
770 if (n)
771 ret = !!(n->flags & NTF_ROUTER);
772 read_unlock_bh(&nd_tbl.lock);
773
774 return ret;
775}
776
777void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
778 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
779 struct ndisc_options *ndopts)
780{
781 neigh_update(neigh, lladdr, new, flags, 0);
782 /* report ndisc ops about neighbour update */
783 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
784}
785
786static void ndisc_recv_ns(struct sk_buff *skb)
787{
788 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
789 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
790 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
791 u8 *lladdr = NULL;
792 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
793 offsetof(struct nd_msg, opt));
794 struct ndisc_options ndopts;
795 struct net_device *dev = skb->dev;
796 struct inet6_ifaddr *ifp;
797 struct inet6_dev *idev = NULL;
798 struct neighbour *neigh;
799 int dad = ipv6_addr_any(saddr);
800 bool inc;
801 int is_router = -1;
802 u64 nonce = 0;
803
804 if (skb->len < sizeof(struct nd_msg)) {
805 ND_PRINTK(2, warn, "NS: packet too short\n");
806 return;
807 }
808
809 if (ipv6_addr_is_multicast(&msg->target)) {
810 ND_PRINTK(2, warn, "NS: multicast target address\n");
811 return;
812 }
813
814 /*
815 * RFC2461 7.1.1:
816 * DAD has to be destined for solicited node multicast address.
817 */
818 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
819 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
820 return;
821 }
822
823 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
824 ND_PRINTK(2, warn, "NS: invalid ND options\n");
825 return;
826 }
827
828 if (ndopts.nd_opts_src_lladdr) {
829 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
830 if (!lladdr) {
831 ND_PRINTK(2, warn,
832 "NS: invalid link-layer address length\n");
833 return;
834 }
835
836 /* RFC2461 7.1.1:
837 * If the IP source address is the unspecified address,
838 * there MUST NOT be source link-layer address option
839 * in the message.
840 */
841 if (dad) {
842 ND_PRINTK(2, warn,
843 "NS: bad DAD packet (link-layer address option)\n");
844 return;
845 }
846 }
847 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
848 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
849
850 inc = ipv6_addr_is_multicast(daddr);
851
852 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
853 if (ifp) {
854have_ifp:
855 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
856 if (dad) {
857 if (nonce != 0 && ifp->dad_nonce == nonce) {
858 u8 *np = (u8 *)&nonce;
859 /* Matching nonce if looped back */
860 ND_PRINTK(2, notice,
861 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
862 ifp->idev->dev->name,
863 &ifp->addr, np);
864 goto out;
865 }
866 /*
867 * We are colliding with another node
868 * who is doing DAD
869 * so fail our DAD process
870 */
871 addrconf_dad_failure(skb, ifp);
872 return;
873 } else {
874 /*
875 * This is not a dad solicitation.
876 * If we are an optimistic node,
877 * we should respond.
878 * Otherwise, we should ignore it.
879 */
880 if (!(ifp->flags & IFA_F_OPTIMISTIC))
881 goto out;
882 }
883 }
884
885 idev = ifp->idev;
886 } else {
887 struct net *net = dev_net(dev);
888
889 /* perhaps an address on the master device */
890 if (netif_is_l3_slave(dev)) {
891 struct net_device *mdev;
892
893 mdev = netdev_master_upper_dev_get_rcu(dev);
894 if (mdev) {
895 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
896 if (ifp)
897 goto have_ifp;
898 }
899 }
900
901 idev = in6_dev_get(dev);
902 if (!idev) {
903 /* XXX: count this drop? */
904 return;
905 }
906
907 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
908 (idev->cnf.forwarding &&
909 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
910 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
911 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
912 skb->pkt_type != PACKET_HOST &&
913 inc &&
914 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
915 /*
916 * for anycast or proxy,
917 * sender should delay its response
918 * by a random time between 0 and
919 * MAX_ANYCAST_DELAY_TIME seconds.
920 * (RFC2461) -- yoshfuji
921 */
922 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
923 if (n)
924 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
925 goto out;
926 }
927 } else
928 goto out;
929 }
930
931 if (is_router < 0)
932 is_router = idev->cnf.forwarding;
933
934 if (dad) {
935 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
936 !!is_router, false, (ifp != NULL), true);
937 goto out;
938 }
939
940 if (inc)
941 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
942 else
943 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
944
945 /*
946 * update / create cache entry
947 * for the source address
948 */
949 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
950 !inc || lladdr || !dev->addr_len);
951 if (neigh)
952 ndisc_update(dev, neigh, lladdr, NUD_STALE,
953 NEIGH_UPDATE_F_WEAK_OVERRIDE|
954 NEIGH_UPDATE_F_OVERRIDE,
955 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
956 if (neigh || !dev->header_ops) {
957 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
958 true, (ifp != NULL && inc), inc);
959 if (neigh)
960 neigh_release(neigh);
961 }
962
963out:
964 if (ifp)
965 in6_ifa_put(ifp);
966 else
967 in6_dev_put(idev);
968}
969
970static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
971{
972 struct inet6_dev *idev = __in6_dev_get(dev);
973
974 switch (idev->cnf.accept_untracked_na) {
975 case 0: /* Don't accept untracked na (absent in neighbor cache) */
976 return 0;
977 case 1: /* Create new entries from na if currently untracked */
978 return 1;
979 case 2: /* Create new entries from untracked na only if saddr is in the
980 * same subnet as an address configured on the interface that
981 * received the na
982 */
983 return !!ipv6_chk_prefix(saddr, dev);
984 default:
985 return 0;
986 }
987}
988
989static void ndisc_recv_na(struct sk_buff *skb)
990{
991 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
992 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
993 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
994 u8 *lladdr = NULL;
995 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
996 offsetof(struct nd_msg, opt));
997 struct ndisc_options ndopts;
998 struct net_device *dev = skb->dev;
999 struct inet6_dev *idev = __in6_dev_get(dev);
1000 struct inet6_ifaddr *ifp;
1001 struct neighbour *neigh;
1002 u8 new_state;
1003
1004 if (skb->len < sizeof(struct nd_msg)) {
1005 ND_PRINTK(2, warn, "NA: packet too short\n");
1006 return;
1007 }
1008
1009 if (ipv6_addr_is_multicast(&msg->target)) {
1010 ND_PRINTK(2, warn, "NA: target address is multicast\n");
1011 return;
1012 }
1013
1014 if (ipv6_addr_is_multicast(daddr) &&
1015 msg->icmph.icmp6_solicited) {
1016 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
1017 return;
1018 }
1019
1020 /* For some 802.11 wireless deployments (and possibly other networks),
1021 * there will be a NA proxy and unsolicitd packets are attacks
1022 * and thus should not be accepted.
1023 * drop_unsolicited_na takes precedence over accept_untracked_na
1024 */
1025 if (!msg->icmph.icmp6_solicited && idev &&
1026 idev->cnf.drop_unsolicited_na)
1027 return;
1028
1029 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
1030 ND_PRINTK(2, warn, "NS: invalid ND option\n");
1031 return;
1032 }
1033 if (ndopts.nd_opts_tgt_lladdr) {
1034 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1035 if (!lladdr) {
1036 ND_PRINTK(2, warn,
1037 "NA: invalid link-layer address length\n");
1038 return;
1039 }
1040 }
1041 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1042 if (ifp) {
1043 if (skb->pkt_type != PACKET_LOOPBACK
1044 && (ifp->flags & IFA_F_TENTATIVE)) {
1045 addrconf_dad_failure(skb, ifp);
1046 return;
1047 }
1048 /* What should we make now? The advertisement
1049 is invalid, but ndisc specs say nothing
1050 about it. It could be misconfiguration, or
1051 an smart proxy agent tries to help us :-)
1052
1053 We should not print the error if NA has been
1054 received from loopback - it is just our own
1055 unsolicited advertisement.
1056 */
1057 if (skb->pkt_type != PACKET_LOOPBACK)
1058 ND_PRINTK(1, warn,
1059 "NA: %pM advertised our address %pI6c on %s!\n",
1060 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1061 in6_ifa_put(ifp);
1062 return;
1063 }
1064
1065 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1066
1067 /* RFC 9131 updates original Neighbour Discovery RFC 4861.
1068 * NAs with Target LL Address option without a corresponding
1069 * entry in the neighbour cache can now create a STALE neighbour
1070 * cache entry on routers.
1071 *
1072 * entry accept fwding solicited behaviour
1073 * ------- ------ ------ --------- ----------------------
1074 * present X X 0 Set state to STALE
1075 * present X X 1 Set state to REACHABLE
1076 * absent 0 X X Do nothing
1077 * absent 1 0 X Do nothing
1078 * absent 1 1 X Add a new STALE entry
1079 *
1080 * Note that we don't do a (daddr == all-routers-mcast) check.
1081 */
1082 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1083 if (!neigh && lladdr && idev && idev->cnf.forwarding) {
1084 if (accept_untracked_na(dev, saddr)) {
1085 neigh = neigh_create(&nd_tbl, &msg->target, dev);
1086 new_state = NUD_STALE;
1087 }
1088 }
1089
1090 if (neigh && !IS_ERR(neigh)) {
1091 u8 old_flags = neigh->flags;
1092 struct net *net = dev_net(dev);
1093
1094 if (neigh->nud_state & NUD_FAILED)
1095 goto out;
1096
1097 /*
1098 * Don't update the neighbor cache entry on a proxy NA from
1099 * ourselves because either the proxied node is off link or it
1100 * has already sent a NA to us.
1101 */
1102 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1103 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1104 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1105 /* XXX: idev->cnf.proxy_ndp */
1106 goto out;
1107 }
1108
1109 ndisc_update(dev, neigh, lladdr,
1110 new_state,
1111 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1112 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1113 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1114 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1115 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1116
1117 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1118 /*
1119 * Change: router to host
1120 */
1121 rt6_clean_tohost(dev_net(dev), saddr);
1122 }
1123
1124out:
1125 neigh_release(neigh);
1126 }
1127}
1128
1129static void ndisc_recv_rs(struct sk_buff *skb)
1130{
1131 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1132 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1133 struct neighbour *neigh;
1134 struct inet6_dev *idev;
1135 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1136 struct ndisc_options ndopts;
1137 u8 *lladdr = NULL;
1138
1139 if (skb->len < sizeof(*rs_msg))
1140 return;
1141
1142 idev = __in6_dev_get(skb->dev);
1143 if (!idev) {
1144 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1145 return;
1146 }
1147
1148 /* Don't accept RS if we're not in router mode */
1149 if (!idev->cnf.forwarding)
1150 goto out;
1151
1152 /*
1153 * Don't update NCE if src = ::;
1154 * this implies that the source node has no ip address assigned yet.
1155 */
1156 if (ipv6_addr_any(saddr))
1157 goto out;
1158
1159 /* Parse ND options */
1160 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1161 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1162 goto out;
1163 }
1164
1165 if (ndopts.nd_opts_src_lladdr) {
1166 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1167 skb->dev);
1168 if (!lladdr)
1169 goto out;
1170 }
1171
1172 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1173 if (neigh) {
1174 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1175 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1176 NEIGH_UPDATE_F_OVERRIDE|
1177 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1178 NDISC_ROUTER_SOLICITATION, &ndopts);
1179 neigh_release(neigh);
1180 }
1181out:
1182 return;
1183}
1184
1185static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1186{
1187 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1188 struct sk_buff *skb;
1189 struct nlmsghdr *nlh;
1190 struct nduseroptmsg *ndmsg;
1191 struct net *net = dev_net(ra->dev);
1192 int err;
1193 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1194 + (opt->nd_opt_len << 3));
1195 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1196
1197 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1198 if (!skb) {
1199 err = -ENOBUFS;
1200 goto errout;
1201 }
1202
1203 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1204 if (!nlh) {
1205 goto nla_put_failure;
1206 }
1207
1208 ndmsg = nlmsg_data(nlh);
1209 ndmsg->nduseropt_family = AF_INET6;
1210 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1211 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1212 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1213 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1214
1215 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1216
1217 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1218 goto nla_put_failure;
1219 nlmsg_end(skb, nlh);
1220
1221 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1222 return;
1223
1224nla_put_failure:
1225 nlmsg_free(skb);
1226 err = -EMSGSIZE;
1227errout:
1228 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1229}
1230
1231static void ndisc_router_discovery(struct sk_buff *skb)
1232{
1233 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1234 struct neighbour *neigh = NULL;
1235 struct inet6_dev *in6_dev;
1236 struct fib6_info *rt = NULL;
1237 u32 defrtr_usr_metric;
1238 struct net *net;
1239 int lifetime;
1240 struct ndisc_options ndopts;
1241 int optlen;
1242 unsigned int pref = 0;
1243 __u32 old_if_flags;
1244 bool send_ifinfo_notify = false;
1245
1246 __u8 *opt = (__u8 *)(ra_msg + 1);
1247
1248 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1249 sizeof(struct ra_msg);
1250
1251 ND_PRINTK(2, info,
1252 "RA: %s, dev: %s\n",
1253 __func__, skb->dev->name);
1254 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1255 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1256 return;
1257 }
1258 if (optlen < 0) {
1259 ND_PRINTK(2, warn, "RA: packet too short\n");
1260 return;
1261 }
1262
1263#ifdef CONFIG_IPV6_NDISC_NODETYPE
1264 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1265 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1266 return;
1267 }
1268#endif
1269
1270 /*
1271 * set the RA_RECV flag in the interface
1272 */
1273
1274 in6_dev = __in6_dev_get(skb->dev);
1275 if (!in6_dev) {
1276 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1277 skb->dev->name);
1278 return;
1279 }
1280
1281 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1282 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1283 return;
1284 }
1285
1286 if (!ipv6_accept_ra(in6_dev)) {
1287 ND_PRINTK(2, info,
1288 "RA: %s, did not accept ra for dev: %s\n",
1289 __func__, skb->dev->name);
1290 goto skip_linkparms;
1291 }
1292
1293#ifdef CONFIG_IPV6_NDISC_NODETYPE
1294 /* skip link-specific parameters from interior routers */
1295 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1296 ND_PRINTK(2, info,
1297 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1298 __func__, skb->dev->name);
1299 goto skip_linkparms;
1300 }
1301#endif
1302
1303 if (in6_dev->if_flags & IF_RS_SENT) {
1304 /*
1305 * flag that an RA was received after an RS was sent
1306 * out on this interface.
1307 */
1308 in6_dev->if_flags |= IF_RA_RCVD;
1309 }
1310
1311 /*
1312 * Remember the managed/otherconf flags from most recently
1313 * received RA message (RFC 2462) -- yoshfuji
1314 */
1315 old_if_flags = in6_dev->if_flags;
1316 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1317 IF_RA_OTHERCONF)) |
1318 (ra_msg->icmph.icmp6_addrconf_managed ?
1319 IF_RA_MANAGED : 0) |
1320 (ra_msg->icmph.icmp6_addrconf_other ?
1321 IF_RA_OTHERCONF : 0);
1322
1323 if (old_if_flags != in6_dev->if_flags)
1324 send_ifinfo_notify = true;
1325
1326 if (!in6_dev->cnf.accept_ra_defrtr) {
1327 ND_PRINTK(2, info,
1328 "RA: %s, defrtr is false for dev: %s\n",
1329 __func__, skb->dev->name);
1330 goto skip_defrtr;
1331 }
1332
1333 /* Do not accept RA with source-addr found on local machine unless
1334 * accept_ra_from_local is set to true.
1335 */
1336 net = dev_net(in6_dev->dev);
1337 if (!in6_dev->cnf.accept_ra_from_local &&
1338 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1339 ND_PRINTK(2, info,
1340 "RA from local address detected on dev: %s: default router ignored\n",
1341 skb->dev->name);
1342 goto skip_defrtr;
1343 }
1344
1345 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1346
1347#ifdef CONFIG_IPV6_ROUTER_PREF
1348 pref = ra_msg->icmph.icmp6_router_pref;
1349 /* 10b is handled as if it were 00b (medium) */
1350 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1351 !in6_dev->cnf.accept_ra_rtr_pref)
1352 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1353#endif
1354 /* routes added from RAs do not use nexthop objects */
1355 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1356 if (rt) {
1357 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1358 rt->fib6_nh->fib_nh_dev, NULL,
1359 &ipv6_hdr(skb)->saddr);
1360 if (!neigh) {
1361 ND_PRINTK(0, err,
1362 "RA: %s got default router without neighbour\n",
1363 __func__);
1364 fib6_info_release(rt);
1365 return;
1366 }
1367 }
1368 /* Set default route metric as specified by user */
1369 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1370 /* delete the route if lifetime is 0 or if metric needs change */
1371 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1372 ip6_del_rt(net, rt, false);
1373 rt = NULL;
1374 }
1375
1376 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
1377 rt, lifetime, defrtr_usr_metric, skb->dev->name);
1378 if (!rt && lifetime) {
1379 ND_PRINTK(3, info, "RA: adding default router\n");
1380
1381 if (neigh)
1382 neigh_release(neigh);
1383
1384 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1385 skb->dev, pref, defrtr_usr_metric);
1386 if (!rt) {
1387 ND_PRINTK(0, err,
1388 "RA: %s failed to add default route\n",
1389 __func__);
1390 return;
1391 }
1392
1393 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1394 rt->fib6_nh->fib_nh_dev, NULL,
1395 &ipv6_hdr(skb)->saddr);
1396 if (!neigh) {
1397 ND_PRINTK(0, err,
1398 "RA: %s got default router without neighbour\n",
1399 __func__);
1400 fib6_info_release(rt);
1401 return;
1402 }
1403 neigh->flags |= NTF_ROUTER;
1404 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1405 struct nl_info nlinfo = {
1406 .nl_net = net,
1407 };
1408 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1409 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
1410 }
1411
1412 if (rt)
1413 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1414 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1415 ra_msg->icmph.icmp6_hop_limit) {
1416 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1417 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1418 fib6_metric_set(rt, RTAX_HOPLIMIT,
1419 ra_msg->icmph.icmp6_hop_limit);
1420 } else {
1421 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1422 }
1423 }
1424
1425skip_defrtr:
1426
1427 /*
1428 * Update Reachable Time and Retrans Timer
1429 */
1430
1431 if (in6_dev->nd_parms) {
1432 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1433
1434 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1435 rtime = (rtime*HZ)/1000;
1436 if (rtime < HZ/100)
1437 rtime = HZ/100;
1438 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1439 in6_dev->tstamp = jiffies;
1440 send_ifinfo_notify = true;
1441 }
1442
1443 rtime = ntohl(ra_msg->reachable_time);
1444 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1445 rtime = (rtime*HZ)/1000;
1446
1447 if (rtime < HZ/10)
1448 rtime = HZ/10;
1449
1450 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1451 NEIGH_VAR_SET(in6_dev->nd_parms,
1452 BASE_REACHABLE_TIME, rtime);
1453 NEIGH_VAR_SET(in6_dev->nd_parms,
1454 GC_STALETIME, 3 * rtime);
1455 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1456 in6_dev->tstamp = jiffies;
1457 send_ifinfo_notify = true;
1458 }
1459 }
1460 }
1461
1462skip_linkparms:
1463
1464 /*
1465 * Process options.
1466 */
1467
1468 if (!neigh)
1469 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1470 skb->dev, 1);
1471 if (neigh) {
1472 u8 *lladdr = NULL;
1473 if (ndopts.nd_opts_src_lladdr) {
1474 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1475 skb->dev);
1476 if (!lladdr) {
1477 ND_PRINTK(2, warn,
1478 "RA: invalid link-layer address length\n");
1479 goto out;
1480 }
1481 }
1482 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1483 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1484 NEIGH_UPDATE_F_OVERRIDE|
1485 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1486 NEIGH_UPDATE_F_ISROUTER,
1487 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1488 }
1489
1490 if (!ipv6_accept_ra(in6_dev)) {
1491 ND_PRINTK(2, info,
1492 "RA: %s, accept_ra is false for dev: %s\n",
1493 __func__, skb->dev->name);
1494 goto out;
1495 }
1496
1497#ifdef CONFIG_IPV6_ROUTE_INFO
1498 if (!in6_dev->cnf.accept_ra_from_local &&
1499 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1500 in6_dev->dev, 0)) {
1501 ND_PRINTK(2, info,
1502 "RA from local address detected on dev: %s: router info ignored.\n",
1503 skb->dev->name);
1504 goto skip_routeinfo;
1505 }
1506
1507 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1508 struct nd_opt_hdr *p;
1509 for (p = ndopts.nd_opts_ri;
1510 p;
1511 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1512 struct route_info *ri = (struct route_info *)p;
1513#ifdef CONFIG_IPV6_NDISC_NODETYPE
1514 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1515 ri->prefix_len == 0)
1516 continue;
1517#endif
1518 if (ri->prefix_len == 0 &&
1519 !in6_dev->cnf.accept_ra_defrtr)
1520 continue;
1521 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1522 continue;
1523 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1524 continue;
1525 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1526 &ipv6_hdr(skb)->saddr);
1527 }
1528 }
1529
1530skip_routeinfo:
1531#endif
1532
1533#ifdef CONFIG_IPV6_NDISC_NODETYPE
1534 /* skip link-specific ndopts from interior routers */
1535 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1536 ND_PRINTK(2, info,
1537 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1538 __func__, skb->dev->name);
1539 goto out;
1540 }
1541#endif
1542
1543 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1544 struct nd_opt_hdr *p;
1545 for (p = ndopts.nd_opts_pi;
1546 p;
1547 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1548 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1549 (p->nd_opt_len) << 3,
1550 ndopts.nd_opts_src_lladdr != NULL);
1551 }
1552 }
1553
1554 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1555 __be32 n;
1556 u32 mtu;
1557
1558 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1559 mtu = ntohl(n);
1560
1561 if (in6_dev->ra_mtu != mtu) {
1562 in6_dev->ra_mtu = mtu;
1563 send_ifinfo_notify = true;
1564 }
1565
1566 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1567 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1568 } else if (in6_dev->cnf.mtu6 != mtu) {
1569 in6_dev->cnf.mtu6 = mtu;
1570 fib6_metric_set(rt, RTAX_MTU, mtu);
1571 rt6_mtu_change(skb->dev, mtu);
1572 }
1573 }
1574
1575 if (ndopts.nd_useropts) {
1576 struct nd_opt_hdr *p;
1577 for (p = ndopts.nd_useropts;
1578 p;
1579 p = ndisc_next_useropt(skb->dev, p,
1580 ndopts.nd_useropts_end)) {
1581 ndisc_ra_useropt(skb, p);
1582 }
1583 }
1584
1585 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1586 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1587 }
1588out:
1589 /* Send a notify if RA changed managed/otherconf flags or
1590 * timer settings or ra_mtu value
1591 */
1592 if (send_ifinfo_notify)
1593 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1594
1595 fib6_info_release(rt);
1596 if (neigh)
1597 neigh_release(neigh);
1598}
1599
1600static void ndisc_redirect_rcv(struct sk_buff *skb)
1601{
1602 u8 *hdr;
1603 struct ndisc_options ndopts;
1604 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1605 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1606 offsetof(struct rd_msg, opt));
1607
1608#ifdef CONFIG_IPV6_NDISC_NODETYPE
1609 switch (skb->ndisc_nodetype) {
1610 case NDISC_NODETYPE_HOST:
1611 case NDISC_NODETYPE_NODEFAULT:
1612 ND_PRINTK(2, warn,
1613 "Redirect: from host or unauthorized router\n");
1614 return;
1615 }
1616#endif
1617
1618 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1619 ND_PRINTK(2, warn,
1620 "Redirect: source address is not link-local\n");
1621 return;
1622 }
1623
1624 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1625 return;
1626
1627 if (!ndopts.nd_opts_rh) {
1628 ip6_redirect_no_header(skb, dev_net(skb->dev),
1629 skb->dev->ifindex);
1630 return;
1631 }
1632
1633 hdr = (u8 *)ndopts.nd_opts_rh;
1634 hdr += 8;
1635 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1636 return;
1637
1638 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1639}
1640
1641static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1642 struct sk_buff *orig_skb,
1643 int rd_len)
1644{
1645 u8 *opt = skb_put(skb, rd_len);
1646
1647 memset(opt, 0, 8);
1648 *(opt++) = ND_OPT_REDIRECT_HDR;
1649 *(opt++) = (rd_len >> 3);
1650 opt += 6;
1651
1652 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1653 rd_len - 8);
1654}
1655
1656void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1657{
1658 struct net_device *dev = skb->dev;
1659 struct net *net = dev_net(dev);
1660 struct sock *sk = net->ipv6.ndisc_sk;
1661 int optlen = 0;
1662 struct inet_peer *peer;
1663 struct sk_buff *buff;
1664 struct rd_msg *msg;
1665 struct in6_addr saddr_buf;
1666 struct rt6_info *rt;
1667 struct dst_entry *dst;
1668 struct flowi6 fl6;
1669 int rd_len;
1670 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1671 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1672 bool ret;
1673
1674 if (netif_is_l3_master(skb->dev)) {
1675 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1676 if (!dev)
1677 return;
1678 }
1679
1680 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1681 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1682 dev->name);
1683 return;
1684 }
1685
1686 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1687 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1688 ND_PRINTK(2, warn,
1689 "Redirect: target address is not link-local unicast\n");
1690 return;
1691 }
1692
1693 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1694 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1695
1696 dst = ip6_route_output(net, NULL, &fl6);
1697 if (dst->error) {
1698 dst_release(dst);
1699 return;
1700 }
1701 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1702 if (IS_ERR(dst))
1703 return;
1704
1705 rt = (struct rt6_info *) dst;
1706
1707 if (rt->rt6i_flags & RTF_GATEWAY) {
1708 ND_PRINTK(2, warn,
1709 "Redirect: destination is not a neighbour\n");
1710 goto release;
1711 }
1712 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1713 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1714 if (peer)
1715 inet_putpeer(peer);
1716 if (!ret)
1717 goto release;
1718
1719 if (dev->addr_len) {
1720 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1721 if (!neigh) {
1722 ND_PRINTK(2, warn,
1723 "Redirect: no neigh for target address\n");
1724 goto release;
1725 }
1726
1727 read_lock_bh(&neigh->lock);
1728 if (neigh->nud_state & NUD_VALID) {
1729 memcpy(ha_buf, neigh->ha, dev->addr_len);
1730 read_unlock_bh(&neigh->lock);
1731 ha = ha_buf;
1732 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1733 ops_data_buf,
1734 &ops_data);
1735 } else
1736 read_unlock_bh(&neigh->lock);
1737
1738 neigh_release(neigh);
1739 }
1740
1741 rd_len = min_t(unsigned int,
1742 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1743 skb->len + 8);
1744 rd_len &= ~0x7;
1745 optlen += rd_len;
1746
1747 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1748 if (!buff)
1749 goto release;
1750
1751 msg = skb_put(buff, sizeof(*msg));
1752 *msg = (struct rd_msg) {
1753 .icmph = {
1754 .icmp6_type = NDISC_REDIRECT,
1755 },
1756 .target = *target,
1757 .dest = ipv6_hdr(skb)->daddr,
1758 };
1759
1760 /*
1761 * include target_address option
1762 */
1763
1764 if (ha)
1765 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1766
1767 /*
1768 * build redirect option and copy skb over to the new packet.
1769 */
1770
1771 if (rd_len)
1772 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1773
1774 skb_dst_set(buff, dst);
1775 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1776 return;
1777
1778release:
1779 dst_release(dst);
1780}
1781
1782static void pndisc_redo(struct sk_buff *skb)
1783{
1784 ndisc_recv_ns(skb);
1785 kfree_skb(skb);
1786}
1787
1788static int ndisc_is_multicast(const void *pkey)
1789{
1790 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1791}
1792
1793static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1794{
1795 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1796
1797 if (!idev)
1798 return true;
1799 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1800 idev->cnf.suppress_frag_ndisc) {
1801 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1802 return true;
1803 }
1804 return false;
1805}
1806
1807int ndisc_rcv(struct sk_buff *skb)
1808{
1809 struct nd_msg *msg;
1810
1811 if (ndisc_suppress_frag_ndisc(skb))
1812 return 0;
1813
1814 if (skb_linearize(skb))
1815 return 0;
1816
1817 msg = (struct nd_msg *)skb_transport_header(skb);
1818
1819 __skb_push(skb, skb->data - skb_transport_header(skb));
1820
1821 if (ipv6_hdr(skb)->hop_limit != 255) {
1822 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1823 ipv6_hdr(skb)->hop_limit);
1824 return 0;
1825 }
1826
1827 if (msg->icmph.icmp6_code != 0) {
1828 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1829 msg->icmph.icmp6_code);
1830 return 0;
1831 }
1832
1833 switch (msg->icmph.icmp6_type) {
1834 case NDISC_NEIGHBOUR_SOLICITATION:
1835 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1836 ndisc_recv_ns(skb);
1837 break;
1838
1839 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1840 ndisc_recv_na(skb);
1841 break;
1842
1843 case NDISC_ROUTER_SOLICITATION:
1844 ndisc_recv_rs(skb);
1845 break;
1846
1847 case NDISC_ROUTER_ADVERTISEMENT:
1848 ndisc_router_discovery(skb);
1849 break;
1850
1851 case NDISC_REDIRECT:
1852 ndisc_redirect_rcv(skb);
1853 break;
1854 }
1855
1856 return 0;
1857}
1858
1859static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1860{
1861 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1862 struct netdev_notifier_change_info *change_info;
1863 struct net *net = dev_net(dev);
1864 struct inet6_dev *idev;
1865 bool evict_nocarrier;
1866
1867 switch (event) {
1868 case NETDEV_CHANGEADDR:
1869 neigh_changeaddr(&nd_tbl, dev);
1870 fib6_run_gc(0, net, false);
1871 fallthrough;
1872 case NETDEV_UP:
1873 idev = in6_dev_get(dev);
1874 if (!idev)
1875 break;
1876 if (idev->cnf.ndisc_notify ||
1877 net->ipv6.devconf_all->ndisc_notify)
1878 ndisc_send_unsol_na(dev);
1879 in6_dev_put(idev);
1880 break;
1881 case NETDEV_CHANGE:
1882 idev = in6_dev_get(dev);
1883 if (!idev)
1884 evict_nocarrier = true;
1885 else {
1886 evict_nocarrier = idev->cnf.ndisc_evict_nocarrier &&
1887 net->ipv6.devconf_all->ndisc_evict_nocarrier;
1888 in6_dev_put(idev);
1889 }
1890
1891 change_info = ptr;
1892 if (change_info->flags_changed & IFF_NOARP)
1893 neigh_changeaddr(&nd_tbl, dev);
1894 if (evict_nocarrier && !netif_carrier_ok(dev))
1895 neigh_carrier_down(&nd_tbl, dev);
1896 break;
1897 case NETDEV_DOWN:
1898 neigh_ifdown(&nd_tbl, dev);
1899 fib6_run_gc(0, net, false);
1900 break;
1901 case NETDEV_NOTIFY_PEERS:
1902 ndisc_send_unsol_na(dev);
1903 break;
1904 default:
1905 break;
1906 }
1907
1908 return NOTIFY_DONE;
1909}
1910
1911static struct notifier_block ndisc_netdev_notifier = {
1912 .notifier_call = ndisc_netdev_event,
1913 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1914};
1915
1916#ifdef CONFIG_SYSCTL
1917static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1918 const char *func, const char *dev_name)
1919{
1920 static char warncomm[TASK_COMM_LEN];
1921 static int warned;
1922 if (strcmp(warncomm, current->comm) && warned < 5) {
1923 strcpy(warncomm, current->comm);
1924 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1925 warncomm, func,
1926 dev_name, ctl->procname,
1927 dev_name, ctl->procname);
1928 warned++;
1929 }
1930}
1931
1932int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1933 size_t *lenp, loff_t *ppos)
1934{
1935 struct net_device *dev = ctl->extra1;
1936 struct inet6_dev *idev;
1937 int ret;
1938
1939 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1940 (strcmp(ctl->procname, "base_reachable_time") == 0))
1941 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1942
1943 if (strcmp(ctl->procname, "retrans_time") == 0)
1944 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1945
1946 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1947 ret = neigh_proc_dointvec_jiffies(ctl, write,
1948 buffer, lenp, ppos);
1949
1950 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1951 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1952 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1953 buffer, lenp, ppos);
1954 else
1955 ret = -1;
1956
1957 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1958 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1959 idev->nd_parms->reachable_time =
1960 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1961 idev->tstamp = jiffies;
1962 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1963 in6_dev_put(idev);
1964 }
1965 return ret;
1966}
1967
1968
1969#endif
1970
1971static int __net_init ndisc_net_init(struct net *net)
1972{
1973 struct ipv6_pinfo *np;
1974 struct sock *sk;
1975 int err;
1976
1977 err = inet_ctl_sock_create(&sk, PF_INET6,
1978 SOCK_RAW, IPPROTO_ICMPV6, net);
1979 if (err < 0) {
1980 ND_PRINTK(0, err,
1981 "NDISC: Failed to initialize the control socket (err %d)\n",
1982 err);
1983 return err;
1984 }
1985
1986 net->ipv6.ndisc_sk = sk;
1987
1988 np = inet6_sk(sk);
1989 np->hop_limit = 255;
1990 /* Do not loopback ndisc messages */
1991 np->mc_loop = 0;
1992
1993 return 0;
1994}
1995
1996static void __net_exit ndisc_net_exit(struct net *net)
1997{
1998 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1999}
2000
2001static struct pernet_operations ndisc_net_ops = {
2002 .init = ndisc_net_init,
2003 .exit = ndisc_net_exit,
2004};
2005
2006int __init ndisc_init(void)
2007{
2008 int err;
2009
2010 err = register_pernet_subsys(&ndisc_net_ops);
2011 if (err)
2012 return err;
2013 /*
2014 * Initialize the neighbour table
2015 */
2016 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
2017
2018#ifdef CONFIG_SYSCTL
2019 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
2020 ndisc_ifinfo_sysctl_change);
2021 if (err)
2022 goto out_unregister_pernet;
2023out:
2024#endif
2025 return err;
2026
2027#ifdef CONFIG_SYSCTL
2028out_unregister_pernet:
2029 unregister_pernet_subsys(&ndisc_net_ops);
2030 goto out;
2031#endif
2032}
2033
2034int __init ndisc_late_init(void)
2035{
2036 return register_netdevice_notifier(&ndisc_netdev_notifier);
2037}
2038
2039void ndisc_late_cleanup(void)
2040{
2041 unregister_netdevice_notifier(&ndisc_netdev_notifier);
2042}
2043
2044void ndisc_cleanup(void)
2045{
2046#ifdef CONFIG_SYSCTL
2047 neigh_sysctl_unregister(&nd_tbl.parms);
2048#endif
2049 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
2050 unregister_pernet_subsys(&ndisc_net_ops);
2051}