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_DEFAULT,
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(addr_len: data_len, pad);
150 u8 *opt = skb_put(skb, len: space);
151
152 opt[0] = type;
153 opt[1] = space>>3;
154
155 memset(s: opt + 2, c: 0, n: pad);
156 opt += pad;
157 space -= pad;
158
159 memcpy(to: opt+2, from: data, len: data_len);
160 data_len += 2;
161 opt += data_len;
162 space -= data_len;
163 if (space > 0)
164 memset(s: opt, c: 0, n: 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(type: skb->dev->type));
173 ndisc_ops_fill_addr_option(dev: 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, type: ND_OPT_TARGET_LL_ADDR, data: ha, NDISC_REDIRECT);
181 ndisc_ops_fill_redirect_addr_option(dev: skb->dev, skb, ha: ops_data);
182}
183
184static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
185 struct nd_opt_hdr *end)
186{
187 int type;
188 if (!cur || !end || cur >= end)
189 return NULL;
190 type = cur->nd_opt_type;
191 do {
192 cur = ((void *)cur) + (cur->nd_opt_len << 3);
193 } while (cur < end && cur->nd_opt_type != type);
194 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
195}
196
197static inline int ndisc_is_useropt(const struct net_device *dev,
198 struct nd_opt_hdr *opt)
199{
200 return opt->nd_opt_type == ND_OPT_PREFIX_INFO ||
201 opt->nd_opt_type == ND_OPT_RDNSS ||
202 opt->nd_opt_type == ND_OPT_DNSSL ||
203 opt->nd_opt_type == ND_OPT_6CO ||
204 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
205 opt->nd_opt_type == ND_OPT_PREF64;
206}
207
208static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
209 struct nd_opt_hdr *cur,
210 struct nd_opt_hdr *end)
211{
212 if (!cur || !end || cur >= end)
213 return NULL;
214 do {
215 cur = ((void *)cur) + (cur->nd_opt_len << 3);
216 } while (cur < end && !ndisc_is_useropt(dev, opt: cur));
217 return cur <= end && ndisc_is_useropt(dev, opt: 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(s: ndopts, c: 0, n: sizeof(*ndopts));
229 while (opt_len) {
230 bool unknown = false;
231 int l;
232 if (opt_len < sizeof(struct nd_opt_hdr))
233 return NULL;
234 l = nd_opt->nd_opt_len << 3;
235 if (opt_len < l || l == 0)
236 return NULL;
237 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
238 goto next_opt;
239 switch (nd_opt->nd_opt_type) {
240 case ND_OPT_SOURCE_LL_ADDR:
241 case ND_OPT_TARGET_LL_ADDR:
242 case ND_OPT_MTU:
243 case ND_OPT_NONCE:
244 case ND_OPT_REDIRECT_HDR:
245 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
246 net_dbg_ratelimited("%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 unknown = true;
266 }
267 if (ndisc_is_useropt(dev, opt: nd_opt)) {
268 ndopts->nd_useropts_end = nd_opt;
269 if (!ndopts->nd_useropts)
270 ndopts->nd_useropts = nd_opt;
271 } else if (unknown) {
272 /*
273 * Unknown options must be silently ignored,
274 * to accommodate future extension to the
275 * protocol.
276 */
277 net_dbg_ratelimited("%s: ignored unsupported option; type=%d, len=%d\n",
278 __func__, nd_opt->nd_opt_type, nd_opt->nd_opt_len);
279 }
280next_opt:
281 opt_len -= l;
282 nd_opt = ((void *)nd_opt) + l;
283 }
284 return ndopts;
285}
286
287int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
288{
289 switch (dev->type) {
290 case ARPHRD_ETHER:
291 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
292 case ARPHRD_FDDI:
293 ipv6_eth_mc_map(addr, buf);
294 return 0;
295 case ARPHRD_ARCNET:
296 ipv6_arcnet_mc_map(addr, buf);
297 return 0;
298 case ARPHRD_INFINIBAND:
299 ipv6_ib_mc_map(addr, broadcast: dev->broadcast, buf);
300 return 0;
301 case ARPHRD_IPGRE:
302 return ipv6_ipgre_mc_map(addr, broadcast: dev->broadcast, buf);
303 default:
304 if (dir) {
305 memcpy(to: buf, from: dev->broadcast, len: dev->addr_len);
306 return 0;
307 }
308 }
309 return -EINVAL;
310}
311EXPORT_SYMBOL(ndisc_mc_map);
312
313static u32 ndisc_hash(const void *pkey,
314 const struct net_device *dev,
315 __u32 *hash_rnd)
316{
317 return ndisc_hashfn(pkey, dev, hash_rnd);
318}
319
320static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
321{
322 return neigh_key_eq128(n, pkey);
323}
324
325static int ndisc_constructor(struct neighbour *neigh)
326{
327 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
328 struct net_device *dev = neigh->dev;
329 struct inet6_dev *in6_dev;
330 struct neigh_parms *parms;
331 bool is_multicast = ipv6_addr_is_multicast(addr);
332
333 in6_dev = in6_dev_get(dev);
334 if (!in6_dev) {
335 return -EINVAL;
336 }
337
338 parms = in6_dev->nd_parms;
339 __neigh_parms_put(parms: neigh->parms);
340 neigh->parms = neigh_parms_clone(parms);
341
342 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
343 if (!dev->header_ops) {
344 neigh->nud_state = NUD_NOARP;
345 neigh->ops = &ndisc_direct_ops;
346 neigh->output = neigh_direct_output;
347 } else {
348 if (is_multicast) {
349 neigh->nud_state = NUD_NOARP;
350 ndisc_mc_map(addr, neigh->ha, dev, 1);
351 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
352 neigh->nud_state = NUD_NOARP;
353 memcpy(to: neigh->ha, from: dev->dev_addr, len: dev->addr_len);
354 if (dev->flags&IFF_LOOPBACK)
355 neigh->type = RTN_LOCAL;
356 } else if (dev->flags&IFF_POINTOPOINT) {
357 neigh->nud_state = NUD_NOARP;
358 memcpy(to: neigh->ha, from: dev->broadcast, len: dev->addr_len);
359 }
360 if (dev->header_ops->cache)
361 neigh->ops = &ndisc_hh_ops;
362 else
363 neigh->ops = &ndisc_generic_ops;
364 if (neigh->nud_state&NUD_VALID)
365 neigh->output = neigh->ops->connected_output;
366 else
367 neigh->output = neigh->ops->output;
368 }
369 in6_dev_put(idev: in6_dev);
370 return 0;
371}
372
373static int pndisc_constructor(struct pneigh_entry *n)
374{
375 struct in6_addr *addr = (struct in6_addr *)&n->key;
376 struct net_device *dev = n->dev;
377 struct in6_addr maddr;
378
379 if (!dev)
380 return -EINVAL;
381
382 addrconf_addr_solict_mult(addr, solicited: &maddr);
383 return ipv6_dev_mc_inc(dev, addr: &maddr);
384}
385
386static void pndisc_destructor(struct pneigh_entry *n)
387{
388 struct in6_addr *addr = (struct in6_addr *)&n->key;
389 struct net_device *dev = n->dev;
390 struct in6_addr maddr;
391
392 if (!dev)
393 return;
394
395 addrconf_addr_solict_mult(addr, solicited: &maddr);
396 ipv6_dev_mc_dec(dev, addr: &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 sk_buff *skb;
419
420 skb = alloc_skb(size: hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
421 if (!skb)
422 return NULL;
423
424 skb->protocol = htons(ETH_P_IPV6);
425 skb->dev = dev;
426
427 skb_reserve(skb, len: hlen + sizeof(struct ipv6hdr));
428 skb_reset_transport_header(skb);
429
430 /* Manually assign socket ownership as we avoid calling
431 * sock_alloc_send_pskb() to bypass wmem buffer limits
432 */
433 rcu_read_lock();
434 skb_set_owner_w(skb, sk: dev_net_rcu(dev)->ipv6.ndisc_sk);
435 rcu_read_unlock();
436
437 return skb;
438}
439
440static void ip6_nd_hdr(struct sk_buff *skb,
441 const struct in6_addr *saddr,
442 const struct in6_addr *daddr,
443 int hop_limit, int len)
444{
445 struct ipv6hdr *hdr;
446 struct inet6_dev *idev;
447 unsigned tclass;
448
449 rcu_read_lock();
450 idev = __in6_dev_get(dev: skb->dev);
451 tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0;
452 rcu_read_unlock();
453
454 skb_push(skb, len: sizeof(*hdr));
455 skb_reset_network_header(skb);
456 hdr = ipv6_hdr(skb);
457
458 ip6_flow_hdr(hdr, tclass, flowlabel: 0);
459
460 hdr->payload_len = htons(len);
461 hdr->nexthdr = IPPROTO_ICMPV6;
462 hdr->hop_limit = hop_limit;
463
464 hdr->saddr = *saddr;
465 hdr->daddr = *daddr;
466}
467
468void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
469 const struct in6_addr *saddr)
470{
471 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
472 struct dst_entry *dst = skb_dst(skb);
473 struct net_device *dev;
474 struct inet6_dev *idev;
475 struct net *net;
476 struct sock *sk;
477 int err;
478 u8 type;
479
480 type = icmp6h->icmp6_type;
481
482 rcu_read_lock();
483
484 net = dev_net_rcu(dev: skb->dev);
485 sk = net->ipv6.ndisc_sk;
486 if (!dst) {
487 struct flowi6 fl6;
488 int oif = skb->dev->ifindex;
489
490 icmpv6_flow_init(sk, fl6: &fl6, type, saddr, daddr, oif);
491 dst = icmp6_dst_alloc(dev: skb->dev, fl6: &fl6);
492 if (IS_ERR(ptr: dst)) {
493 rcu_read_unlock();
494 kfree_skb(skb);
495 return;
496 }
497
498 skb_dst_set(skb, dst);
499 }
500
501 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len: skb->len,
502 IPPROTO_ICMPV6,
503 sum: csum_partial(buff: icmp6h,
504 len: skb->len, sum: 0));
505
506 ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), len: skb->len);
507
508 dev = dst_dev_rcu(dst);
509 idev = __in6_dev_get(dev);
510 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
511
512 err = NF_HOOK(pf: NFPROTO_IPV6, hook: NF_INET_LOCAL_OUT,
513 net, sk, skb, NULL, out: dev,
514 okfn: dst_output);
515 if (!err) {
516 ICMP6MSGOUT_INC_STATS(net, idev, type);
517 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
518 }
519
520 rcu_read_unlock();
521}
522EXPORT_SYMBOL(ndisc_send_skb);
523
524void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
525 const struct in6_addr *solicited_addr,
526 bool router, bool solicited, bool override, bool inc_opt)
527{
528 struct sk_buff *skb;
529 struct in6_addr tmpaddr;
530 struct inet6_ifaddr *ifp;
531 const struct in6_addr *src_addr;
532 struct nd_msg *msg;
533 int optlen = 0;
534
535 /* for anycast or proxy, solicited_addr != src_addr */
536 ifp = ipv6_get_ifaddr(net: dev_net(dev), addr: solicited_addr, dev, strict: 1);
537 if (ifp) {
538 src_addr = solicited_addr;
539 if (ifp->flags & IFA_F_OPTIMISTIC)
540 override = false;
541 inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao);
542 in6_ifa_put(ifp);
543 } else {
544 if (ipv6_dev_get_saddr(net: dev_net(dev), dev, daddr,
545 srcprefs: inet6_sk(sk: dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
546 saddr: &tmpaddr))
547 return;
548 src_addr = &tmpaddr;
549 }
550
551 if (!dev->addr_len)
552 inc_opt = false;
553 if (inc_opt)
554 optlen += ndisc_opt_addr_space(dev,
555 NDISC_NEIGHBOUR_ADVERTISEMENT);
556
557 skb = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen);
558 if (!skb)
559 return;
560
561 msg = skb_put(skb, len: sizeof(*msg));
562 *msg = (struct nd_msg) {
563 .icmph = {
564 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
565 .icmp6_router = router,
566 .icmp6_solicited = solicited,
567 .icmp6_override = override,
568 },
569 .target = *solicited_addr,
570 };
571
572 if (inc_opt)
573 ndisc_fill_addr_option(skb, type: ND_OPT_TARGET_LL_ADDR,
574 data: dev->dev_addr,
575 NDISC_NEIGHBOUR_ADVERTISEMENT);
576
577 ndisc_send_skb(skb, daddr, src_addr);
578}
579
580static void ndisc_send_unsol_na(struct net_device *dev)
581{
582 struct inet6_dev *idev;
583 struct inet6_ifaddr *ifa;
584
585 idev = in6_dev_get(dev);
586 if (!idev)
587 return;
588
589 read_lock_bh(&idev->lock);
590 list_for_each_entry(ifa, &idev->addr_list, if_list) {
591 /* skip tentative addresses until dad completes */
592 if (ifa->flags & IFA_F_TENTATIVE &&
593 !(ifa->flags & IFA_F_OPTIMISTIC))
594 continue;
595
596 ndisc_send_na(dev, daddr: &in6addr_linklocal_allnodes, solicited_addr: &ifa->addr,
597 /*router=*/ !!idev->cnf.forwarding,
598 /*solicited=*/ false, /*override=*/ true,
599 /*inc_opt=*/ true);
600 }
601 read_unlock_bh(&idev->lock);
602
603 in6_dev_put(idev);
604}
605
606struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
607 const struct in6_addr *saddr, u64 nonce)
608{
609 int inc_opt = dev->addr_len;
610 struct sk_buff *skb;
611 struct nd_msg *msg;
612 int optlen = 0;
613
614 if (!saddr)
615 return NULL;
616
617 if (ipv6_addr_any(a: saddr))
618 inc_opt = false;
619 if (inc_opt)
620 optlen += ndisc_opt_addr_space(dev,
621 NDISC_NEIGHBOUR_SOLICITATION);
622 if (nonce != 0)
623 optlen += 8;
624
625 skb = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen);
626 if (!skb)
627 return NULL;
628
629 msg = skb_put(skb, len: sizeof(*msg));
630 *msg = (struct nd_msg) {
631 .icmph = {
632 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
633 },
634 .target = *solicit,
635 };
636
637 if (inc_opt)
638 ndisc_fill_addr_option(skb, type: ND_OPT_SOURCE_LL_ADDR,
639 data: dev->dev_addr,
640 NDISC_NEIGHBOUR_SOLICITATION);
641 if (nonce != 0) {
642 u8 *opt = skb_put(skb, len: 8);
643
644 opt[0] = ND_OPT_NONCE;
645 opt[1] = 8 >> 3;
646 memcpy(to: opt + 2, from: &nonce, len: 6);
647 }
648
649 return skb;
650}
651EXPORT_SYMBOL(ndisc_ns_create);
652
653void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
654 const struct in6_addr *daddr, const struct in6_addr *saddr,
655 u64 nonce)
656{
657 struct in6_addr addr_buf;
658 struct sk_buff *skb;
659
660 if (!saddr) {
661 if (ipv6_get_lladdr(dev, addr: &addr_buf,
662 banned_flags: (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
663 return;
664 saddr = &addr_buf;
665 }
666
667 skb = ndisc_ns_create(dev, solicit, saddr, nonce);
668
669 if (skb)
670 ndisc_send_skb(skb, daddr, saddr);
671}
672
673void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
674 const struct in6_addr *daddr)
675{
676 struct sk_buff *skb;
677 struct rs_msg *msg;
678 int send_sllao = dev->addr_len;
679 int optlen = 0;
680
681#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
682 /*
683 * According to section 2.2 of RFC 4429, we must not
684 * send router solicitations with a sllao from
685 * optimistic addresses, but we may send the solicitation
686 * if we don't include the sllao. So here we check
687 * if our address is optimistic, and if so, we
688 * suppress the inclusion of the sllao.
689 */
690 if (send_sllao) {
691 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
692 dev, 1);
693 if (ifp) {
694 if (ifp->flags & IFA_F_OPTIMISTIC) {
695 send_sllao = 0;
696 }
697 in6_ifa_put(ifp);
698 } else {
699 send_sllao = 0;
700 }
701 }
702#endif
703 if (send_sllao)
704 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
705
706 skb = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen);
707 if (!skb)
708 return;
709
710 msg = skb_put(skb, len: sizeof(*msg));
711 *msg = (struct rs_msg) {
712 .icmph = {
713 .icmp6_type = NDISC_ROUTER_SOLICITATION,
714 },
715 };
716
717 if (send_sllao)
718 ndisc_fill_addr_option(skb, type: ND_OPT_SOURCE_LL_ADDR,
719 data: dev->dev_addr,
720 NDISC_ROUTER_SOLICITATION);
721
722 ndisc_send_skb(skb, daddr, saddr);
723}
724
725
726static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
727{
728 /*
729 * "The sender MUST return an ICMP
730 * destination unreachable"
731 */
732 dst_link_failure(skb);
733 kfree_skb(skb);
734}
735
736/* Called with locked neigh: either read or both */
737
738static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
739{
740 struct in6_addr *saddr = NULL;
741 struct in6_addr mcaddr;
742 struct net_device *dev = neigh->dev;
743 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
744 int probes = atomic_read(v: &neigh->probes);
745
746 if (skb && ipv6_chk_addr_and_flags(net: dev_net(dev), addr: &ipv6_hdr(skb)->saddr,
747 dev, skip_dev_check: false, strict: 1,
748 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
749 saddr = &ipv6_hdr(skb)->saddr;
750 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
751 if (probes < 0) {
752 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) {
753 net_dbg_ratelimited("%s: trying to ucast probe in NUD_INVALID: %pI6\n",
754 __func__, target);
755 }
756 ndisc_send_ns(dev, solicit: target, daddr: target, saddr, nonce: 0);
757 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
758 neigh_app_ns(n: neigh);
759 } else {
760 addrconf_addr_solict_mult(addr: target, solicited: &mcaddr);
761 ndisc_send_ns(dev, solicit: target, daddr: &mcaddr, saddr, nonce: 0);
762 }
763}
764
765static int pndisc_is_router(const void *pkey,
766 struct net_device *dev)
767{
768 struct pneigh_entry *n;
769 int ret = -1;
770
771 n = pneigh_lookup(tbl: &nd_tbl, net: dev_net(dev), key: pkey, dev);
772 if (n)
773 ret = !!(READ_ONCE(n->flags) & NTF_ROUTER);
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, nlmsg_pid: 0);
783 /* report ndisc ops about neighbour update */
784 ndisc_ops_update(dev, n: 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(a: 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(addr: &msg->target)) {
810 net_dbg_ratelimited("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(addr: daddr)) {
819 net_dbg_ratelimited("NS: bad DAD packet (wrong destination)\n");
820 return reason;
821 }
822
823 if (!ndisc_parse_options(dev, opt: msg->opt, opt_len: ndoptlen, ndopts: &ndopts))
824 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
825
826 if (ndopts.nd_opts_src_lladdr) {
827 lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_src_lladdr, dev);
828 if (!lladdr) {
829 net_dbg_ratelimited("NS: invalid link-layer address length\n");
830 return reason;
831 }
832
833 /* RFC2461 7.1.1:
834 * If the IP source address is the unspecified address,
835 * there MUST NOT be source link-layer address option
836 * in the message.
837 */
838 if (dad) {
839 net_dbg_ratelimited("NS: bad DAD packet (link-layer address option)\n");
840 return reason;
841 }
842 }
843 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
844 memcpy(to: &nonce, from: (u8 *)(ndopts.nd_opts_nonce + 1), len: 6);
845
846 inc = ipv6_addr_is_multicast(addr: daddr);
847
848 ifp = ipv6_get_ifaddr(net: dev_net(dev), addr: &msg->target, dev, strict: 1);
849 if (ifp) {
850have_ifp:
851 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
852 if (dad) {
853 if (nonce != 0 && ifp->dad_nonce == nonce) {
854 u8 *np = (u8 *)&nonce;
855 /* Matching nonce if looped back */
856 net_dbg_ratelimited("%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
857 ifp->idev->dev->name, &ifp->addr, np);
858 goto out;
859 }
860 /*
861 * We are colliding with another node
862 * who is doing DAD
863 * so fail our DAD process
864 */
865 addrconf_dad_failure(skb, ifp);
866 return reason;
867 } else {
868 /*
869 * This is not a dad solicitation.
870 * If we are an optimistic node,
871 * we should respond.
872 * Otherwise, we should ignore it.
873 */
874 if (!(ifp->flags & IFA_F_OPTIMISTIC))
875 goto out;
876 }
877 }
878
879 idev = ifp->idev;
880 } else {
881 struct net *net = dev_net(dev);
882
883 /* perhaps an address on the master device */
884 if (netif_is_l3_slave(dev)) {
885 struct net_device *mdev;
886
887 mdev = netdev_master_upper_dev_get_rcu(dev);
888 if (mdev) {
889 ifp = ipv6_get_ifaddr(net, addr: &msg->target, dev: mdev, strict: 1);
890 if (ifp)
891 goto have_ifp;
892 }
893 }
894
895 idev = in6_dev_get(dev);
896 if (!idev) {
897 /* XXX: count this drop? */
898 return reason;
899 }
900
901 if (ipv6_chk_acast_addr(net, dev, addr: &msg->target) ||
902 (READ_ONCE(idev->cnf.forwarding) &&
903 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) ||
904 READ_ONCE(idev->cnf.proxy_ndp)) &&
905 (is_router = pndisc_is_router(pkey: &msg->target, dev)) >= 0)) {
906 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
907 skb->pkt_type != PACKET_HOST &&
908 inc &&
909 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
910 /*
911 * for anycast or proxy,
912 * sender should delay its response
913 * by a random time between 0 and
914 * MAX_ANYCAST_DELAY_TIME seconds.
915 * (RFC2461) -- yoshfuji
916 */
917 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
918 if (n)
919 pneigh_enqueue(tbl: &nd_tbl, p: idev->nd_parms, skb: n);
920 goto out;
921 }
922 } else {
923 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST);
924 goto out;
925 }
926 }
927
928 if (is_router < 0)
929 is_router = READ_ONCE(idev->cnf.forwarding);
930
931 if (dad) {
932 ndisc_send_na(dev, daddr: &in6addr_linklocal_allnodes, solicited_addr: &msg->target,
933 router: !!is_router, solicited: false, override: (ifp != NULL), inc_opt: true);
934 goto out;
935 }
936
937 if (inc)
938 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
939 else
940 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
941
942 /*
943 * update / create cache entry
944 * for the source address
945 */
946 neigh = __neigh_lookup(tbl: &nd_tbl, pkey: saddr, dev,
947 creat: !inc || lladdr || !dev->addr_len);
948 if (neigh)
949 ndisc_update(dev, neigh, lladdr, NUD_STALE,
950 NEIGH_UPDATE_F_WEAK_OVERRIDE|
951 NEIGH_UPDATE_F_OVERRIDE,
952 NDISC_NEIGHBOUR_SOLICITATION, ndopts: &ndopts);
953 if (neigh || !dev->header_ops) {
954 ndisc_send_na(dev, daddr: saddr, solicited_addr: &msg->target, router: !!is_router,
955 solicited: true, override: (ifp != NULL && inc), inc_opt: inc);
956 if (neigh)
957 neigh_release(neigh);
958 reason = SKB_CONSUMED;
959 }
960
961out:
962 if (ifp)
963 in6_ifa_put(ifp);
964 else
965 in6_dev_put(idev);
966 return reason;
967}
968
969static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
970{
971 struct inet6_dev *idev = __in6_dev_get(dev);
972
973 switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
974 case 0: /* Don't accept untracked na (absent in neighbor cache) */
975 return 0;
976 case 1: /* Create new entries from na if currently untracked */
977 return 1;
978 case 2: /* Create new entries from untracked na only if saddr is in the
979 * same subnet as an address configured on the interface that
980 * received the na
981 */
982 return !!ipv6_chk_prefix(addr: saddr, dev);
983 default:
984 return 0;
985 }
986}
987
988static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
989{
990 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
991 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
992 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
993 u8 *lladdr = NULL;
994 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
995 offsetof(struct nd_msg, opt));
996 struct ndisc_options ndopts;
997 struct net_device *dev = skb->dev;
998 struct inet6_dev *idev = __in6_dev_get(dev);
999 struct inet6_ifaddr *ifp;
1000 struct neighbour *neigh;
1001 SKB_DR(reason);
1002 u8 new_state;
1003
1004 if (skb->len < sizeof(struct nd_msg))
1005 return SKB_DROP_REASON_PKT_TOO_SMALL;
1006
1007 if (ipv6_addr_is_multicast(addr: &msg->target)) {
1008 net_dbg_ratelimited("NA: target address is multicast\n");
1009 return reason;
1010 }
1011
1012 if (ipv6_addr_is_multicast(addr: daddr) &&
1013 msg->icmph.icmp6_solicited) {
1014 net_dbg_ratelimited("NA: solicited NA is multicasted\n");
1015 return reason;
1016 }
1017
1018 /* For some 802.11 wireless deployments (and possibly other networks),
1019 * there will be a NA proxy and unsolicitd packets are attacks
1020 * and thus should not be accepted.
1021 * drop_unsolicited_na takes precedence over accept_untracked_na
1022 */
1023 if (!msg->icmph.icmp6_solicited && idev &&
1024 READ_ONCE(idev->cnf.drop_unsolicited_na))
1025 return reason;
1026
1027 if (!ndisc_parse_options(dev, opt: msg->opt, opt_len: ndoptlen, ndopts: &ndopts))
1028 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1029
1030 if (ndopts.nd_opts_tgt_lladdr) {
1031 lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_tgt_lladdr, dev);
1032 if (!lladdr) {
1033 net_dbg_ratelimited("NA: invalid link-layer address length\n");
1034 return reason;
1035 }
1036 }
1037 ifp = ipv6_get_ifaddr(net: dev_net(dev), addr: &msg->target, dev, strict: 1);
1038 if (ifp) {
1039 if (skb->pkt_type != PACKET_LOOPBACK
1040 && (ifp->flags & IFA_F_TENTATIVE)) {
1041 addrconf_dad_failure(skb, ifp);
1042 return reason;
1043 }
1044 /* What should we make now? The advertisement
1045 is invalid, but ndisc specs say nothing
1046 about it. It could be misconfiguration, or
1047 an smart proxy agent tries to help us :-)
1048
1049 We should not print the error if NA has been
1050 received from loopback - it is just our own
1051 unsolicited advertisement.
1052 */
1053 if (skb->pkt_type != PACKET_LOOPBACK)
1054 net_warn_ratelimited("NA: %pM advertised our address %pI6c on %s!\n",
1055 eth_hdr(skb)->h_source, &ifp->addr,
1056 ifp->idev->dev->name);
1057 in6_ifa_put(ifp);
1058 return reason;
1059 }
1060
1061 neigh = neigh_lookup(tbl: &nd_tbl, pkey: &msg->target, dev);
1062
1063 /* RFC 9131 updates original Neighbour Discovery RFC 4861.
1064 * NAs with Target LL Address option without a corresponding
1065 * entry in the neighbour cache can now create a STALE neighbour
1066 * cache entry on routers.
1067 *
1068 * entry accept fwding solicited behaviour
1069 * ------- ------ ------ --------- ----------------------
1070 * present X X 0 Set state to STALE
1071 * present X X 1 Set state to REACHABLE
1072 * absent 0 X X Do nothing
1073 * absent 1 0 X Do nothing
1074 * absent 1 1 X Add a new STALE entry
1075 *
1076 * Note that we don't do a (daddr == all-routers-mcast) check.
1077 */
1078 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1079 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) {
1080 if (accept_untracked_na(dev, saddr)) {
1081 neigh = neigh_create(tbl: &nd_tbl, pkey: &msg->target, dev);
1082 new_state = NUD_STALE;
1083 }
1084 }
1085
1086 if (neigh && !IS_ERR(ptr: neigh)) {
1087 u8 old_flags = neigh->flags;
1088 struct net *net = dev_net(dev);
1089
1090 if (READ_ONCE(neigh->nud_state) & NUD_FAILED)
1091 goto out;
1092
1093 /*
1094 * Don't update the neighbor cache entry on a proxy NA from
1095 * ourselves because either the proxied node is off link or it
1096 * has already sent a NA to us.
1097 */
1098 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1099 READ_ONCE(net->ipv6.devconf_all->forwarding) &&
1100 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
1101 pneigh_lookup(tbl: &nd_tbl, net, key: &msg->target, dev)) {
1102 /* XXX: idev->cnf.proxy_ndp */
1103 goto out;
1104 }
1105
1106 ndisc_update(dev, neigh, lladdr,
1107 new: new_state,
1108 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1109 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1110 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1111 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1112 NDISC_NEIGHBOUR_ADVERTISEMENT, ndopts: &ndopts);
1113
1114 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1115 /*
1116 * Change: router to host
1117 */
1118 rt6_clean_tohost(net: dev_net(dev), gateway: saddr);
1119 }
1120 reason = SKB_CONSUMED;
1121out:
1122 neigh_release(neigh);
1123 }
1124 return reason;
1125}
1126
1127static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
1128{
1129 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1130 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1131 struct neighbour *neigh;
1132 struct inet6_dev *idev;
1133 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1134 struct ndisc_options ndopts;
1135 u8 *lladdr = NULL;
1136 SKB_DR(reason);
1137
1138 if (skb->len < sizeof(*rs_msg))
1139 return SKB_DROP_REASON_PKT_TOO_SMALL;
1140
1141 idev = __in6_dev_get(dev: skb->dev);
1142 if (!idev) {
1143 net_err_ratelimited("RS: can't find in6 device\n");
1144 return reason;
1145 }
1146
1147 /* Don't accept RS if we're not in router mode */
1148 if (!READ_ONCE(idev->cnf.forwarding))
1149 goto out;
1150
1151 /*
1152 * Don't update NCE if src = ::;
1153 * this implies that the source node has no ip address assigned yet.
1154 */
1155 if (ipv6_addr_any(a: saddr))
1156 goto out;
1157
1158 /* Parse ND options */
1159 if (!ndisc_parse_options(dev: skb->dev, opt: rs_msg->opt, opt_len: ndoptlen, ndopts: &ndopts))
1160 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1161
1162 if (ndopts.nd_opts_src_lladdr) {
1163 lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_src_lladdr,
1164 dev: skb->dev);
1165 if (!lladdr)
1166 goto out;
1167 }
1168
1169 neigh = __neigh_lookup(tbl: &nd_tbl, pkey: saddr, dev: skb->dev, creat: 1);
1170 if (neigh) {
1171 ndisc_update(dev: skb->dev, neigh, lladdr, NUD_STALE,
1172 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1173 NEIGH_UPDATE_F_OVERRIDE|
1174 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1175 NDISC_ROUTER_SOLICITATION, ndopts: &ndopts);
1176 neigh_release(neigh);
1177 reason = SKB_CONSUMED;
1178 }
1179out:
1180 return reason;
1181}
1182
1183static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1184{
1185 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(skb: ra);
1186 struct sk_buff *skb;
1187 struct nlmsghdr *nlh;
1188 struct nduseroptmsg *ndmsg;
1189 struct net *net = dev_net(dev: ra->dev);
1190 int err;
1191 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1192 + (opt->nd_opt_len << 3));
1193 size_t msg_size = base_size + nla_total_size(payload: sizeof(struct in6_addr));
1194
1195 skb = nlmsg_new(payload: msg_size, GFP_ATOMIC);
1196 if (!skb) {
1197 err = -ENOBUFS;
1198 goto errout;
1199 }
1200
1201 nlh = nlmsg_put(skb, portid: 0, seq: 0, RTM_NEWNDUSEROPT, payload: base_size, flags: 0);
1202 if (!nlh) {
1203 goto nla_put_failure;
1204 }
1205
1206 ndmsg = nlmsg_data(nlh);
1207 ndmsg->nduseropt_family = AF_INET6;
1208 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1209 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1210 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1211 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1212
1213 memcpy(to: ndmsg + 1, from: opt, len: opt->nd_opt_len << 3);
1214
1215 if (nla_put_in6_addr(skb, attrtype: NDUSEROPT_SRCADDR, addr: &ipv6_hdr(skb: ra)->saddr))
1216 goto nla_put_failure;
1217 nlmsg_end(skb, nlh);
1218
1219 rtnl_notify(skb, net, pid: 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1220 return;
1221
1222nla_put_failure:
1223 nlmsg_free(skb);
1224 err = -EMSGSIZE;
1225errout:
1226 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, error: err);
1227}
1228
1229static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
1230{
1231 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1232 bool send_ifinfo_notify = false;
1233 struct neighbour *neigh = NULL;
1234 struct ndisc_options ndopts;
1235 struct fib6_info *rt = NULL;
1236 struct inet6_dev *in6_dev;
1237 struct fib6_table *table;
1238 u32 defrtr_usr_metric;
1239 unsigned int pref = 0;
1240 __u32 old_if_flags;
1241 struct net *net;
1242 SKB_DR(reason);
1243 int lifetime;
1244 int optlen;
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 net_dbg_ratelimited("RA: %s, dev: %s\n", __func__, skb->dev->name);
1252 if (!(ipv6_addr_type(addr: &ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1253 net_dbg_ratelimited("RA: source address is not link-local\n");
1254 return reason;
1255 }
1256 if (optlen < 0)
1257 return SKB_DROP_REASON_PKT_TOO_SMALL;
1258
1259#ifdef CONFIG_IPV6_NDISC_NODETYPE
1260 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1261 net_dbg_ratelimited("RA: from host or unauthorized router\n");
1262 return reason;
1263 }
1264#endif
1265
1266 in6_dev = __in6_dev_get(dev: skb->dev);
1267 if (!in6_dev) {
1268 net_err_ratelimited("RA: can't find inet6 device for %s\n", skb->dev->name);
1269 return reason;
1270 }
1271
1272 if (!ndisc_parse_options(dev: skb->dev, opt, opt_len: optlen, ndopts: &ndopts))
1273 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1274
1275 if (!ipv6_accept_ra(idev: in6_dev)) {
1276 net_dbg_ratelimited("RA: %s, did not accept ra for dev: %s\n", __func__,
1277 skb->dev->name);
1278 goto skip_linkparms;
1279 }
1280
1281#ifdef CONFIG_IPV6_NDISC_NODETYPE
1282 /* skip link-specific parameters from interior routers */
1283 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1284 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT, dev: %s\n", __func__,
1285 skb->dev->name);
1286 goto skip_linkparms;
1287 }
1288#endif
1289
1290 if (in6_dev->if_flags & IF_RS_SENT) {
1291 /*
1292 * flag that an RA was received after an RS was sent
1293 * out on this interface.
1294 */
1295 in6_dev->if_flags |= IF_RA_RCVD;
1296 }
1297
1298 /*
1299 * Remember the managed/otherconf flags from most recently
1300 * received RA message (RFC 2462) -- yoshfuji
1301 */
1302 old_if_flags = in6_dev->if_flags;
1303 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1304 IF_RA_OTHERCONF)) |
1305 (ra_msg->icmph.icmp6_addrconf_managed ?
1306 IF_RA_MANAGED : 0) |
1307 (ra_msg->icmph.icmp6_addrconf_other ?
1308 IF_RA_OTHERCONF : 0);
1309
1310 if (old_if_flags != in6_dev->if_flags)
1311 send_ifinfo_notify = true;
1312
1313 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) {
1314 net_dbg_ratelimited("RA: %s, defrtr is false for dev: %s\n", __func__,
1315 skb->dev->name);
1316 goto skip_defrtr;
1317 }
1318
1319 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1320 if (lifetime != 0 &&
1321 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) {
1322 net_dbg_ratelimited("RA: router lifetime (%ds) is too short: %s\n", lifetime,
1323 skb->dev->name);
1324 goto skip_defrtr;
1325 }
1326
1327 /* Do not accept RA with source-addr found on local machine unless
1328 * accept_ra_from_local is set to true.
1329 */
1330 net = dev_net(dev: in6_dev->dev);
1331 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1332 ipv6_chk_addr(net, addr: &ipv6_hdr(skb)->saddr, dev: in6_dev->dev, strict: 0)) {
1333 net_dbg_ratelimited("RA from local address detected on dev: %s: default router ignored\n",
1334 skb->dev->name);
1335 goto skip_defrtr;
1336 }
1337
1338#ifdef CONFIG_IPV6_ROUTER_PREF
1339 pref = ra_msg->icmph.icmp6_router_pref;
1340 /* 10b is handled as if it were 00b (medium) */
1341 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1342 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref))
1343 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1344#endif
1345 /* routes added from RAs do not use nexthop objects */
1346 rt = rt6_get_dflt_router(net, addr: &ipv6_hdr(skb)->saddr, dev: skb->dev);
1347 if (rt) {
1348 neigh = ip6_neigh_lookup(gw: &rt->fib6_nh->fib_nh_gw6,
1349 dev: rt->fib6_nh->fib_nh_dev, NULL,
1350 daddr: &ipv6_hdr(skb)->saddr);
1351 if (!neigh) {
1352 net_err_ratelimited("RA: %s got default router without neighbour\n",
1353 __func__);
1354 fib6_info_release(f6i: rt);
1355 return reason;
1356 }
1357 }
1358 /* Set default route metric as specified by user */
1359 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1360 /* delete the route if lifetime is 0 or if metric needs change */
1361 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1362 ip6_del_rt(net, f6i: rt, skip_notify: false);
1363 rt = NULL;
1364 }
1365
1366 net_dbg_ratelimited("RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", rt, lifetime,
1367 defrtr_usr_metric, skb->dev->name);
1368 if (!rt && lifetime) {
1369 net_dbg_ratelimited("RA: adding default router\n");
1370
1371 if (neigh)
1372 neigh_release(neigh);
1373
1374 rt = rt6_add_dflt_router(net, gwaddr: &ipv6_hdr(skb)->saddr,
1375 dev: skb->dev, pref, defrtr_usr_metric,
1376 lifetime);
1377 if (!rt) {
1378 net_err_ratelimited("RA: %s failed to add default route\n", __func__);
1379 return reason;
1380 }
1381
1382 neigh = ip6_neigh_lookup(gw: &rt->fib6_nh->fib_nh_gw6,
1383 dev: rt->fib6_nh->fib_nh_dev, NULL,
1384 daddr: &ipv6_hdr(skb)->saddr);
1385 if (!neigh) {
1386 net_err_ratelimited("RA: %s got default router without neighbour\n",
1387 __func__);
1388 fib6_info_release(f6i: rt);
1389 return reason;
1390 }
1391 neigh->flags |= NTF_ROUTER;
1392 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1393 struct nl_info nlinfo = {
1394 .nl_net = net,
1395 };
1396 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1397 inet6_rt_notify(RTM_NEWROUTE, rt, info: &nlinfo, NLM_F_REPLACE);
1398 }
1399
1400 if (rt) {
1401 table = rt->fib6_table;
1402 spin_lock_bh(lock: &table->tb6_lock);
1403
1404 fib6_set_expires(f6i: rt, expires: jiffies + (HZ * lifetime));
1405 fib6_add_gc_list(f6i: rt);
1406
1407 spin_unlock_bh(lock: &table->tb6_lock);
1408 }
1409 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 &&
1410 ra_msg->icmph.icmp6_hop_limit) {
1411 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <=
1412 ra_msg->icmph.icmp6_hop_limit) {
1413 WRITE_ONCE(in6_dev->cnf.hop_limit,
1414 ra_msg->icmph.icmp6_hop_limit);
1415 fib6_metric_set(f6i: rt, RTAX_HOPLIMIT,
1416 val: ra_msg->icmph.icmp6_hop_limit);
1417 } else {
1418 net_dbg_ratelimited("RA: Got route advertisement with lower hop_limit than minimum\n");
1419 }
1420 }
1421
1422skip_defrtr:
1423
1424 /*
1425 * Update Reachable Time and Retrans Timer
1426 */
1427
1428 if (in6_dev->nd_parms) {
1429 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1430
1431 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1432 rtime = (rtime*HZ)/1000;
1433 if (rtime < HZ/100)
1434 rtime = HZ/100;
1435 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1436 in6_dev->tstamp = jiffies;
1437 send_ifinfo_notify = true;
1438 }
1439
1440 rtime = ntohl(ra_msg->reachable_time);
1441 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1442 rtime = (rtime*HZ)/1000;
1443
1444 if (rtime < HZ/10)
1445 rtime = HZ/10;
1446
1447 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1448 NEIGH_VAR_SET(in6_dev->nd_parms,
1449 BASE_REACHABLE_TIME, rtime);
1450 NEIGH_VAR_SET(in6_dev->nd_parms,
1451 GC_STALETIME, 3 * rtime);
1452 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(base: rtime);
1453 in6_dev->tstamp = jiffies;
1454 send_ifinfo_notify = true;
1455 }
1456 }
1457 }
1458
1459skip_linkparms:
1460
1461 /*
1462 * Process options.
1463 */
1464
1465 if (!neigh)
1466 neigh = __neigh_lookup(tbl: &nd_tbl, pkey: &ipv6_hdr(skb)->saddr,
1467 dev: skb->dev, creat: 1);
1468 if (neigh) {
1469 u8 *lladdr = NULL;
1470 if (ndopts.nd_opts_src_lladdr) {
1471 lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_src_lladdr,
1472 dev: skb->dev);
1473 if (!lladdr) {
1474 net_dbg_ratelimited("RA: invalid link-layer address length\n");
1475 goto out;
1476 }
1477 }
1478 ndisc_update(dev: skb->dev, neigh, lladdr, NUD_STALE,
1479 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1480 NEIGH_UPDATE_F_OVERRIDE|
1481 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1482 NEIGH_UPDATE_F_ISROUTER,
1483 NDISC_ROUTER_ADVERTISEMENT, ndopts: &ndopts);
1484 reason = SKB_CONSUMED;
1485 }
1486
1487 if (!ipv6_accept_ra(idev: in6_dev)) {
1488 net_dbg_ratelimited("RA: %s, accept_ra is false for dev: %s\n", __func__,
1489 skb->dev->name);
1490 goto out;
1491 }
1492
1493#ifdef CONFIG_IPV6_ROUTE_INFO
1494 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1495 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1496 in6_dev->dev, 0)) {
1497 net_dbg_ratelimited("RA from local address detected on dev: %s: router info ignored.\n",
1498 skb->dev->name);
1499 goto skip_routeinfo;
1500 }
1501
1502 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) {
1503 struct nd_opt_hdr *p;
1504 for (p = ndopts.nd_opts_ri;
1505 p;
1506 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1507 struct route_info *ri = (struct route_info *)p;
1508#ifdef CONFIG_IPV6_NDISC_NODETYPE
1509 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1510 ri->prefix_len == 0)
1511 continue;
1512#endif
1513 if (ri->prefix_len == 0 &&
1514 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr))
1515 continue;
1516 if (ri->lifetime != 0 &&
1517 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft))
1518 continue;
1519 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen))
1520 continue;
1521 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen))
1522 continue;
1523 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1524 &ipv6_hdr(skb)->saddr);
1525 }
1526 }
1527
1528skip_routeinfo:
1529#endif
1530
1531#ifdef CONFIG_IPV6_NDISC_NODETYPE
1532 /* skip link-specific ndopts from interior routers */
1533 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1534 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1535 __func__, skb->dev->name);
1536 goto out;
1537 }
1538#endif
1539
1540 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) {
1541 struct nd_opt_hdr *p;
1542 for (p = ndopts.nd_opts_pi;
1543 p;
1544 p = ndisc_next_option(cur: p, end: ndopts.nd_opts_pi_end)) {
1545 addrconf_prefix_rcv(dev: skb->dev, opt: (u8 *)p,
1546 len: (p->nd_opt_len) << 3,
1547 sllao: ndopts.nd_opts_src_lladdr != NULL);
1548 }
1549 }
1550
1551 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) {
1552 __be32 n;
1553 u32 mtu;
1554
1555 memcpy(to: &n, from: ((u8 *)(ndopts.nd_opts_mtu+1))+2, len: sizeof(mtu));
1556 mtu = ntohl(n);
1557
1558 if (in6_dev->ra_mtu != mtu) {
1559 in6_dev->ra_mtu = mtu;
1560 send_ifinfo_notify = true;
1561 }
1562
1563 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1564 net_dbg_ratelimited("RA: invalid mtu: %d\n", mtu);
1565 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) {
1566 WRITE_ONCE(in6_dev->cnf.mtu6, mtu);
1567 fib6_metric_set(f6i: rt, RTAX_MTU, val: mtu);
1568 rt6_mtu_change(dev: skb->dev, mtu);
1569 }
1570 }
1571
1572 if (ndopts.nd_useropts) {
1573 struct nd_opt_hdr *p;
1574 for (p = ndopts.nd_useropts;
1575 p;
1576 p = ndisc_next_useropt(dev: skb->dev, cur: p,
1577 end: ndopts.nd_useropts_end)) {
1578 ndisc_ra_useropt(ra: skb, opt: p);
1579 }
1580 }
1581
1582 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1583 net_dbg_ratelimited("RA: invalid RA options\n");
1584 }
1585out:
1586 /* Send a notify if RA changed managed/otherconf flags or
1587 * timer settings or ra_mtu value
1588 */
1589 if (send_ifinfo_notify)
1590 inet6_ifinfo_notify(RTM_NEWLINK, idev: in6_dev);
1591
1592 fib6_info_release(f6i: rt);
1593 if (neigh)
1594 neigh_release(neigh);
1595 return reason;
1596}
1597
1598static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
1599{
1600 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1601 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1602 offsetof(struct rd_msg, opt));
1603 struct ndisc_options ndopts;
1604 SKB_DR(reason);
1605 u8 *hdr;
1606
1607#ifdef CONFIG_IPV6_NDISC_NODETYPE
1608 switch (skb->ndisc_nodetype) {
1609 case NDISC_NODETYPE_HOST:
1610 case NDISC_NODETYPE_NODEFAULT:
1611 net_dbg_ratelimited("Redirect: from host or unauthorized router\n");
1612 return reason;
1613 }
1614#endif
1615
1616 if (!(ipv6_addr_type(addr: &ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1617 net_dbg_ratelimited("Redirect: source address is not link-local\n");
1618 return reason;
1619 }
1620
1621 if (!ndisc_parse_options(dev: skb->dev, opt: msg->opt, opt_len: ndoptlen, ndopts: &ndopts))
1622 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1623
1624 if (!ndopts.nd_opts_rh) {
1625 ip6_redirect_no_header(skb, net: dev_net(dev: skb->dev),
1626 oif: skb->dev->ifindex);
1627 return reason;
1628 }
1629
1630 hdr = (u8 *)ndopts.nd_opts_rh;
1631 hdr += 8;
1632 if (!pskb_pull(skb, len: hdr - skb_transport_header(skb)))
1633 return SKB_DROP_REASON_PKT_TOO_SMALL;
1634
1635 return icmpv6_notify(skb, NDISC_REDIRECT, code: 0, info: 0);
1636}
1637
1638static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1639 struct sk_buff *orig_skb,
1640 int rd_len)
1641{
1642 u8 *opt = skb_put(skb, len: rd_len);
1643
1644 memset(s: opt, c: 0, n: 8);
1645 *(opt++) = ND_OPT_REDIRECT_HDR;
1646 *(opt++) = (rd_len >> 3);
1647 opt += 6;
1648
1649 skb_copy_bits(skb: orig_skb, offset: skb_network_offset(skb: orig_skb), to: opt,
1650 len: rd_len - 8);
1651}
1652
1653void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1654{
1655 struct net_device *dev = skb->dev;
1656 struct net *net = dev_net_rcu(dev);
1657 struct sock *sk = net->ipv6.ndisc_sk;
1658 int optlen = 0;
1659 struct inet_peer *peer;
1660 struct sk_buff *buff;
1661 struct rd_msg *msg;
1662 struct in6_addr saddr_buf;
1663 struct rt6_info *rt;
1664 struct dst_entry *dst;
1665 struct flowi6 fl6;
1666 int rd_len;
1667 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1668 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1669 bool ret;
1670
1671 if (netif_is_l3_master(dev)) {
1672 dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
1673 if (!dev)
1674 return;
1675 }
1676
1677 if (ipv6_get_lladdr(dev, addr: &saddr_buf, IFA_F_TENTATIVE)) {
1678 net_dbg_ratelimited("Redirect: no link-local address on %s\n", dev->name);
1679 return;
1680 }
1681
1682 if (!ipv6_addr_equal(a1: &ipv6_hdr(skb)->daddr, a2: target) &&
1683 ipv6_addr_type(addr: target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1684 net_dbg_ratelimited("Redirect: target address is not link-local unicast\n");
1685 return;
1686 }
1687
1688 icmpv6_flow_init(sk, fl6: &fl6, NDISC_REDIRECT,
1689 saddr: &saddr_buf, daddr: &ipv6_hdr(skb)->saddr, oif: dev->ifindex);
1690
1691 dst = ip6_route_output(net, NULL, fl6: &fl6);
1692 if (dst->error) {
1693 dst_release(dst);
1694 return;
1695 }
1696 dst = xfrm_lookup(net, dst_orig: dst, fl: flowi6_to_flowi(fl6: &fl6), NULL, flags: 0);
1697 if (IS_ERR(ptr: dst))
1698 return;
1699
1700 rt = dst_rt6_info(dst);
1701
1702 if (rt->rt6i_flags & RTF_GATEWAY) {
1703 net_dbg_ratelimited("Redirect: destination is not a neighbour\n");
1704 goto release;
1705 }
1706
1707 peer = inet_getpeer_v6(base: net->ipv6.peers, v6daddr: &ipv6_hdr(skb)->saddr);
1708 ret = inet_peer_xrlim_allow(peer, timeout: 1*HZ);
1709
1710 if (!ret)
1711 goto release;
1712
1713 if (dev->addr_len) {
1714 struct neighbour *neigh = dst_neigh_lookup(dst: skb_dst(skb), daddr: target);
1715 if (!neigh) {
1716 net_dbg_ratelimited("Redirect: no neigh for target address\n");
1717 goto release;
1718 }
1719
1720 read_lock_bh(&neigh->lock);
1721 if (neigh->nud_state & NUD_VALID) {
1722 memcpy(to: ha_buf, from: neigh->ha, len: dev->addr_len);
1723 read_unlock_bh(&neigh->lock);
1724 ha = ha_buf;
1725 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1726 ops_data_buf,
1727 ops_data: &ops_data);
1728 } else
1729 read_unlock_bh(&neigh->lock);
1730
1731 neigh_release(neigh);
1732 }
1733
1734 rd_len = min_t(unsigned int,
1735 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1736 skb->len + 8);
1737 rd_len &= ~0x7;
1738 optlen += rd_len;
1739
1740 buff = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen);
1741 if (!buff)
1742 goto release;
1743
1744 msg = skb_put(skb: buff, len: sizeof(*msg));
1745 *msg = (struct rd_msg) {
1746 .icmph = {
1747 .icmp6_type = NDISC_REDIRECT,
1748 },
1749 .target = *target,
1750 .dest = ipv6_hdr(skb)->daddr,
1751 };
1752
1753 /*
1754 * include target_address option
1755 */
1756
1757 if (ha)
1758 ndisc_fill_redirect_addr_option(skb: buff, ha, ops_data);
1759
1760 /*
1761 * build redirect option and copy skb over to the new packet.
1762 */
1763
1764 if (rd_len)
1765 ndisc_fill_redirect_hdr_option(skb: buff, orig_skb: skb, rd_len);
1766
1767 skb_dst_set(skb: buff, dst);
1768 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1769 return;
1770
1771release:
1772 dst_release(dst);
1773}
1774
1775static void pndisc_redo(struct sk_buff *skb)
1776{
1777 enum skb_drop_reason reason = ndisc_recv_ns(skb);
1778
1779 kfree_skb_reason(skb, reason);
1780}
1781
1782static int ndisc_is_multicast(const void *pkey)
1783{
1784 return ipv6_addr_is_multicast(addr: (struct in6_addr *)pkey);
1785}
1786
1787static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1788{
1789 struct inet6_dev *idev = __in6_dev_get(dev: skb->dev);
1790
1791 if (!idev)
1792 return true;
1793 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1794 READ_ONCE(idev->cnf.suppress_frag_ndisc)) {
1795 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1796 return true;
1797 }
1798 return false;
1799}
1800
1801enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
1802{
1803 struct nd_msg *msg;
1804 SKB_DR(reason);
1805
1806 if (ndisc_suppress_frag_ndisc(skb))
1807 return SKB_DROP_REASON_IPV6_NDISC_FRAG;
1808
1809 if (skb_linearize(skb))
1810 return SKB_DROP_REASON_NOMEM;
1811
1812 msg = (struct nd_msg *)skb_transport_header(skb);
1813
1814 __skb_push(skb, len: skb->data - skb_transport_header(skb));
1815
1816 if (ipv6_hdr(skb)->hop_limit != 255) {
1817 net_dbg_ratelimited("NDISC: invalid hop-limit: %d\n", ipv6_hdr(skb)->hop_limit);
1818 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT;
1819 }
1820
1821 if (msg->icmph.icmp6_code != 0) {
1822 net_dbg_ratelimited("NDISC: invalid ICMPv6 code: %d\n", msg->icmph.icmp6_code);
1823 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE;
1824 }
1825
1826 switch (msg->icmph.icmp6_type) {
1827 case NDISC_NEIGHBOUR_SOLICITATION:
1828 memset(NEIGH_CB(skb), c: 0, n: sizeof(struct neighbour_cb));
1829 reason = ndisc_recv_ns(skb);
1830 break;
1831
1832 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1833 reason = ndisc_recv_na(skb);
1834 break;
1835
1836 case NDISC_ROUTER_SOLICITATION:
1837 reason = ndisc_recv_rs(skb);
1838 break;
1839
1840 case NDISC_ROUTER_ADVERTISEMENT:
1841 reason = ndisc_router_discovery(skb);
1842 break;
1843
1844 case NDISC_REDIRECT:
1845 reason = ndisc_redirect_rcv(skb);
1846 break;
1847 }
1848
1849 return reason;
1850}
1851
1852static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1853{
1854 struct net_device *dev = netdev_notifier_info_to_dev(info: ptr);
1855 struct netdev_notifier_change_info *change_info;
1856 struct net *net = dev_net(dev);
1857 struct inet6_dev *idev;
1858 bool evict_nocarrier;
1859
1860 switch (event) {
1861 case NETDEV_CHANGEADDR:
1862 neigh_changeaddr(tbl: &nd_tbl, dev);
1863 fib6_run_gc(expires: 0, net, force: false);
1864 fallthrough;
1865 case NETDEV_UP:
1866 idev = in6_dev_get(dev);
1867 if (!idev)
1868 break;
1869 if (READ_ONCE(idev->cnf.ndisc_notify) ||
1870 READ_ONCE(net->ipv6.devconf_all->ndisc_notify))
1871 ndisc_send_unsol_na(dev);
1872 in6_dev_put(idev);
1873 break;
1874 case NETDEV_CHANGE:
1875 idev = in6_dev_get(dev);
1876 if (!idev)
1877 evict_nocarrier = true;
1878 else {
1879 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) &&
1880 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier);
1881 in6_dev_put(idev);
1882 }
1883
1884 change_info = ptr;
1885 if (change_info->flags_changed & IFF_NOARP)
1886 neigh_changeaddr(tbl: &nd_tbl, dev);
1887 if (evict_nocarrier && !netif_carrier_ok(dev))
1888 neigh_carrier_down(tbl: &nd_tbl, dev);
1889 break;
1890 case NETDEV_DOWN:
1891 neigh_ifdown(tbl: &nd_tbl, dev);
1892 fib6_run_gc(expires: 0, net, force: false);
1893 break;
1894 case NETDEV_NOTIFY_PEERS:
1895 ndisc_send_unsol_na(dev);
1896 break;
1897 default:
1898 break;
1899 }
1900
1901 return NOTIFY_DONE;
1902}
1903
1904static struct notifier_block ndisc_netdev_notifier = {
1905 .notifier_call = ndisc_netdev_event,
1906 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1907};
1908
1909#ifdef CONFIG_SYSCTL
1910static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl,
1911 const char *func, const char *dev_name)
1912{
1913 static char warncomm[TASK_COMM_LEN];
1914 static int warned;
1915 if (strcmp(warncomm, current->comm) && warned < 5) {
1916 strscpy(warncomm, current->comm);
1917 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1918 warncomm, func,
1919 dev_name, ctl->procname,
1920 dev_name, ctl->procname);
1921 warned++;
1922 }
1923}
1924
1925int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer,
1926 size_t *lenp, loff_t *ppos)
1927{
1928 struct net_device *dev = ctl->extra1;
1929 struct inet6_dev *idev;
1930 int ret;
1931
1932 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1933 (strcmp(ctl->procname, "base_reachable_time") == 0))
1934 ndisc_warn_deprecated_sysctl(ctl, func: "syscall", dev_name: dev ? dev->name : "default");
1935
1936 if (strcmp(ctl->procname, "retrans_time") == 0)
1937 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1938
1939 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1940 ret = neigh_proc_dointvec_jiffies(ctl, write,
1941 buffer, lenp, ppos);
1942
1943 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1944 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1945 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1946 buffer, lenp, ppos);
1947 else
1948 ret = -1;
1949
1950 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1951 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1952 idev->nd_parms->reachable_time =
1953 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1954 WRITE_ONCE(idev->tstamp, jiffies);
1955 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1956 in6_dev_put(idev);
1957 }
1958 return ret;
1959}
1960
1961
1962#endif
1963
1964static int __net_init ndisc_net_init(struct net *net)
1965{
1966 struct ipv6_pinfo *np;
1967 struct sock *sk;
1968 int err;
1969
1970 err = inet_ctl_sock_create(sk: &sk, PF_INET6,
1971 type: SOCK_RAW, IPPROTO_ICMPV6, net);
1972 if (err < 0) {
1973 net_err_ratelimited("NDISC: Failed to initialize the control socket (err %d)\n",
1974 err);
1975 return err;
1976 }
1977
1978 net->ipv6.ndisc_sk = sk;
1979
1980 np = inet6_sk(sk: sk);
1981 np->hop_limit = 255;
1982 /* Do not loopback ndisc messages */
1983 inet6_clear_bit(MC6_LOOP, sk);
1984
1985 return 0;
1986}
1987
1988static void __net_exit ndisc_net_exit(struct net *net)
1989{
1990 inet_ctl_sock_destroy(sk: net->ipv6.ndisc_sk);
1991}
1992
1993static struct pernet_operations ndisc_net_ops = {
1994 .init = ndisc_net_init,
1995 .exit = ndisc_net_exit,
1996};
1997
1998int __init ndisc_init(void)
1999{
2000 int err;
2001
2002 err = register_pernet_subsys(&ndisc_net_ops);
2003 if (err)
2004 return err;
2005 /*
2006 * Initialize the neighbour table
2007 */
2008 neigh_table_init(index: NEIGH_ND_TABLE, tbl: &nd_tbl);
2009
2010#ifdef CONFIG_SYSCTL
2011 err = neigh_sysctl_register(NULL, p: &nd_tbl.parms,
2012 proc_handler: ndisc_ifinfo_sysctl_change);
2013 if (err)
2014 goto out_unregister_pernet;
2015out:
2016#endif
2017 return err;
2018
2019#ifdef CONFIG_SYSCTL
2020out_unregister_pernet:
2021 unregister_pernet_subsys(&ndisc_net_ops);
2022 goto out;
2023#endif
2024}
2025
2026int __init ndisc_late_init(void)
2027{
2028 return register_netdevice_notifier(nb: &ndisc_netdev_notifier);
2029}
2030
2031void ndisc_late_cleanup(void)
2032{
2033 unregister_netdevice_notifier(nb: &ndisc_netdev_notifier);
2034}
2035
2036void ndisc_cleanup(void)
2037{
2038#ifdef CONFIG_SYSCTL
2039 neigh_sysctl_unregister(p: &nd_tbl.parms);
2040#endif
2041 neigh_table_clear(index: NEIGH_ND_TABLE, tbl: &nd_tbl);
2042 unregister_pernet_subsys(&ndisc_net_ops);
2043}
2044