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Merge tag 'probes-fixes-v6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-block.git] / net / ipv6 / ndisc.c
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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_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, 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 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 ND_PRINTK(2, warn,
247 "%s: duplicated ND6 option found: type=%d\n",
248 __func__, nd_opt->nd_opt_type);
249 } else {
250 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
251 }
252 break;
253 case ND_OPT_PREFIX_INFO:
254 ndopts->nd_opts_pi_end = nd_opt;
255 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
256 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
257 break;
258#ifdef CONFIG_IPV6_ROUTE_INFO
259 case ND_OPT_ROUTE_INFO:
260 ndopts->nd_opts_ri_end = nd_opt;
261 if (!ndopts->nd_opts_ri)
262 ndopts->nd_opts_ri = nd_opt;
263 break;
264#endif
265 default:
266 unknown = true;
267 }
268 if (ndisc_is_useropt(dev, nd_opt)) {
269 ndopts->nd_useropts_end = nd_opt;
270 if (!ndopts->nd_useropts)
271 ndopts->nd_useropts = nd_opt;
272 } else if (unknown) {
273 /*
274 * Unknown options must be silently ignored,
275 * to accommodate future extension to the
276 * protocol.
277 */
278 ND_PRINTK(2, notice,
279 "%s: ignored unsupported option; type=%d, len=%d\n",
280 __func__,
281 nd_opt->nd_opt_type,
282 nd_opt->nd_opt_len);
283 }
284next_opt:
285 opt_len -= l;
286 nd_opt = ((void *)nd_opt) + l;
287 }
288 return ndopts;
289}
290
291int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
292{
293 switch (dev->type) {
294 case ARPHRD_ETHER:
295 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
296 case ARPHRD_FDDI:
297 ipv6_eth_mc_map(addr, buf);
298 return 0;
299 case ARPHRD_ARCNET:
300 ipv6_arcnet_mc_map(addr, buf);
301 return 0;
302 case ARPHRD_INFINIBAND:
303 ipv6_ib_mc_map(addr, dev->broadcast, buf);
304 return 0;
305 case ARPHRD_IPGRE:
306 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
307 default:
308 if (dir) {
309 memcpy(buf, dev->broadcast, dev->addr_len);
310 return 0;
311 }
312 }
313 return -EINVAL;
314}
315EXPORT_SYMBOL(ndisc_mc_map);
316
317static u32 ndisc_hash(const void *pkey,
318 const struct net_device *dev,
319 __u32 *hash_rnd)
320{
321 return ndisc_hashfn(pkey, dev, hash_rnd);
322}
323
324static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
325{
326 return neigh_key_eq128(n, pkey);
327}
328
329static int ndisc_constructor(struct neighbour *neigh)
330{
331 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
332 struct net_device *dev = neigh->dev;
333 struct inet6_dev *in6_dev;
334 struct neigh_parms *parms;
335 bool is_multicast = ipv6_addr_is_multicast(addr);
336
337 in6_dev = in6_dev_get(dev);
338 if (!in6_dev) {
339 return -EINVAL;
340 }
341
342 parms = in6_dev->nd_parms;
343 __neigh_parms_put(neigh->parms);
344 neigh->parms = neigh_parms_clone(parms);
345
346 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
347 if (!dev->header_ops) {
348 neigh->nud_state = NUD_NOARP;
349 neigh->ops = &ndisc_direct_ops;
350 neigh->output = neigh_direct_output;
351 } else {
352 if (is_multicast) {
353 neigh->nud_state = NUD_NOARP;
354 ndisc_mc_map(addr, neigh->ha, dev, 1);
355 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
356 neigh->nud_state = NUD_NOARP;
357 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
358 if (dev->flags&IFF_LOOPBACK)
359 neigh->type = RTN_LOCAL;
360 } else if (dev->flags&IFF_POINTOPOINT) {
361 neigh->nud_state = NUD_NOARP;
362 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
363 }
364 if (dev->header_ops->cache)
365 neigh->ops = &ndisc_hh_ops;
366 else
367 neigh->ops = &ndisc_generic_ops;
368 if (neigh->nud_state&NUD_VALID)
369 neigh->output = neigh->ops->connected_output;
370 else
371 neigh->output = neigh->ops->output;
372 }
373 in6_dev_put(in6_dev);
374 return 0;
375}
376
377static int pndisc_constructor(struct pneigh_entry *n)
378{
379 struct in6_addr *addr = (struct in6_addr *)&n->key;
380 struct in6_addr maddr;
381 struct net_device *dev = n->dev;
382
383 if (!dev || !__in6_dev_get(dev))
384 return -EINVAL;
385 addrconf_addr_solict_mult(addr, &maddr);
386 ipv6_dev_mc_inc(dev, &maddr);
387 return 0;
388}
389
390static void pndisc_destructor(struct pneigh_entry *n)
391{
392 struct in6_addr *addr = (struct in6_addr *)&n->key;
393 struct in6_addr maddr;
394 struct net_device *dev = n->dev;
395
396 if (!dev || !__in6_dev_get(dev))
397 return;
398 addrconf_addr_solict_mult(addr, &maddr);
399 ipv6_dev_mc_dec(dev, &maddr);
400}
401
402/* called with rtnl held */
403static bool ndisc_allow_add(const struct net_device *dev,
404 struct netlink_ext_ack *extack)
405{
406 struct inet6_dev *idev = __in6_dev_get(dev);
407
408 if (!idev || idev->cnf.disable_ipv6) {
409 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
410 return false;
411 }
412
413 return true;
414}
415
416static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
417 int len)
418{
419 int hlen = LL_RESERVED_SPACE(dev);
420 int tlen = dev->needed_tailroom;
421 struct sk_buff *skb;
422
423 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
424 if (!skb)
425 return NULL;
426
427 skb->protocol = htons(ETH_P_IPV6);
428 skb->dev = dev;
429
430 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
431 skb_reset_transport_header(skb);
432
433 /* Manually assign socket ownership as we avoid calling
434 * sock_alloc_send_pskb() to bypass wmem buffer limits
435 */
436 rcu_read_lock();
437 skb_set_owner_w(skb, dev_net_rcu(dev)->ipv6.ndisc_sk);
438 rcu_read_unlock();
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 icmp6hdr *icmp6h = icmp6_hdr(skb);
475 struct dst_entry *dst = skb_dst(skb);
476 struct inet6_dev *idev;
477 struct net *net;
478 struct sock *sk;
479 int err;
480 u8 type;
481
482 type = icmp6h->icmp6_type;
483
484 rcu_read_lock();
485
486 net = dev_net_rcu(skb->dev);
487 sk = net->ipv6.ndisc_sk;
488 if (!dst) {
489 struct flowi6 fl6;
490 int oif = skb->dev->ifindex;
491
492 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
493 dst = icmp6_dst_alloc(skb->dev, &fl6);
494 if (IS_ERR(dst)) {
495 rcu_read_unlock();
496 kfree_skb(skb);
497 return;
498 }
499
500 skb_dst_set(skb, dst);
501 }
502
503 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
504 IPPROTO_ICMPV6,
505 csum_partial(icmp6h,
506 skb->len, 0));
507
508 ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len);
509
510 idev = __in6_dev_get(dst->dev);
511 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
512
513 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
514 net, sk, skb, NULL, dst->dev,
515 dst_output);
516 if (!err) {
517 ICMP6MSGOUT_INC_STATS(net, idev, type);
518 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
519 }
520
521 rcu_read_unlock();
522}
523EXPORT_SYMBOL(ndisc_send_skb);
524
525void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
526 const struct in6_addr *solicited_addr,
527 bool router, bool solicited, bool override, bool inc_opt)
528{
529 struct sk_buff *skb;
530 struct in6_addr tmpaddr;
531 struct inet6_ifaddr *ifp;
532 const struct in6_addr *src_addr;
533 struct nd_msg *msg;
534 int optlen = 0;
535
536 /* for anycast or proxy, solicited_addr != src_addr */
537 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
538 if (ifp) {
539 src_addr = solicited_addr;
540 if (ifp->flags & IFA_F_OPTIMISTIC)
541 override = false;
542 inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao);
543 in6_ifa_put(ifp);
544 } else {
545 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
546 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
547 &tmpaddr))
548 return;
549 src_addr = &tmpaddr;
550 }
551
552 if (!dev->addr_len)
553 inc_opt = false;
554 if (inc_opt)
555 optlen += ndisc_opt_addr_space(dev,
556 NDISC_NEIGHBOUR_ADVERTISEMENT);
557
558 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
559 if (!skb)
560 return;
561
562 msg = skb_put(skb, sizeof(*msg));
563 *msg = (struct nd_msg) {
564 .icmph = {
565 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
566 .icmp6_router = router,
567 .icmp6_solicited = solicited,
568 .icmp6_override = override,
569 },
570 .target = *solicited_addr,
571 };
572
573 if (inc_opt)
574 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
575 dev->dev_addr,
576 NDISC_NEIGHBOUR_ADVERTISEMENT);
577
578 ndisc_send_skb(skb, daddr, src_addr);
579}
580
581static void ndisc_send_unsol_na(struct net_device *dev)
582{
583 struct inet6_dev *idev;
584 struct inet6_ifaddr *ifa;
585
586 idev = in6_dev_get(dev);
587 if (!idev)
588 return;
589
590 read_lock_bh(&idev->lock);
591 list_for_each_entry(ifa, &idev->addr_list, if_list) {
592 /* skip tentative addresses until dad completes */
593 if (ifa->flags & IFA_F_TENTATIVE &&
594 !(ifa->flags & IFA_F_OPTIMISTIC))
595 continue;
596
597 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
598 /*router=*/ !!idev->cnf.forwarding,
599 /*solicited=*/ false, /*override=*/ true,
600 /*inc_opt=*/ true);
601 }
602 read_unlock_bh(&idev->lock);
603
604 in6_dev_put(idev);
605}
606
607struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
608 const struct in6_addr *saddr, u64 nonce)
609{
610 int inc_opt = dev->addr_len;
611 struct sk_buff *skb;
612 struct nd_msg *msg;
613 int optlen = 0;
614
615 if (!saddr)
616 return NULL;
617
618 if (ipv6_addr_any(saddr))
619 inc_opt = false;
620 if (inc_opt)
621 optlen += ndisc_opt_addr_space(dev,
622 NDISC_NEIGHBOUR_SOLICITATION);
623 if (nonce != 0)
624 optlen += 8;
625
626 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
627 if (!skb)
628 return NULL;
629
630 msg = skb_put(skb, sizeof(*msg));
631 *msg = (struct nd_msg) {
632 .icmph = {
633 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
634 },
635 .target = *solicit,
636 };
637
638 if (inc_opt)
639 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
640 dev->dev_addr,
641 NDISC_NEIGHBOUR_SOLICITATION);
642 if (nonce != 0) {
643 u8 *opt = skb_put(skb, 8);
644
645 opt[0] = ND_OPT_NONCE;
646 opt[1] = 8 >> 3;
647 memcpy(opt + 2, &nonce, 6);
648 }
649
650 return skb;
651}
652EXPORT_SYMBOL(ndisc_ns_create);
653
654void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
655 const struct in6_addr *daddr, const struct in6_addr *saddr,
656 u64 nonce)
657{
658 struct in6_addr addr_buf;
659 struct sk_buff *skb;
660
661 if (!saddr) {
662 if (ipv6_get_lladdr(dev, &addr_buf,
663 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
664 return;
665 saddr = &addr_buf;
666 }
667
668 skb = ndisc_ns_create(dev, solicit, saddr, nonce);
669
670 if (skb)
671 ndisc_send_skb(skb, daddr, saddr);
672}
673
674void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
675 const struct in6_addr *daddr)
676{
677 struct sk_buff *skb;
678 struct rs_msg *msg;
679 int send_sllao = dev->addr_len;
680 int optlen = 0;
681
682#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
683 /*
684 * According to section 2.2 of RFC 4429, we must not
685 * send router solicitations with a sllao from
686 * optimistic addresses, but we may send the solicitation
687 * if we don't include the sllao. So here we check
688 * if our address is optimistic, and if so, we
689 * suppress the inclusion of the sllao.
690 */
691 if (send_sllao) {
692 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
693 dev, 1);
694 if (ifp) {
695 if (ifp->flags & IFA_F_OPTIMISTIC) {
696 send_sllao = 0;
697 }
698 in6_ifa_put(ifp);
699 } else {
700 send_sllao = 0;
701 }
702 }
703#endif
704 if (send_sllao)
705 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
706
707 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
708 if (!skb)
709 return;
710
711 msg = skb_put(skb, sizeof(*msg));
712 *msg = (struct rs_msg) {
713 .icmph = {
714 .icmp6_type = NDISC_ROUTER_SOLICITATION,
715 },
716 };
717
718 if (send_sllao)
719 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
720 dev->dev_addr,
721 NDISC_ROUTER_SOLICITATION);
722
723 ndisc_send_skb(skb, daddr, saddr);
724}
725
726
727static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
728{
729 /*
730 * "The sender MUST return an ICMP
731 * destination unreachable"
732 */
733 dst_link_failure(skb);
734 kfree_skb(skb);
735}
736
737/* Called with locked neigh: either read or both */
738
739static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
740{
741 struct in6_addr *saddr = NULL;
742 struct in6_addr mcaddr;
743 struct net_device *dev = neigh->dev;
744 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
745 int probes = atomic_read(&neigh->probes);
746
747 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
748 dev, false, 1,
749 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
750 saddr = &ipv6_hdr(skb)->saddr;
751 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
752 if (probes < 0) {
753 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) {
754 ND_PRINTK(1, dbg,
755 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
756 __func__, target);
757 }
758 ndisc_send_ns(dev, target, target, saddr, 0);
759 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
760 neigh_app_ns(neigh);
761 } else {
762 addrconf_addr_solict_mult(target, &mcaddr);
763 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
764 }
765}
766
767static int pndisc_is_router(const void *pkey,
768 struct net_device *dev)
769{
770 struct pneigh_entry *n;
771 int ret = -1;
772
773 read_lock_bh(&nd_tbl.lock);
774 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
775 if (n)
776 ret = !!(n->flags & NTF_ROUTER);
777 read_unlock_bh(&nd_tbl.lock);
778
779 return ret;
780}
781
782void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
783 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
784 struct ndisc_options *ndopts)
785{
786 neigh_update(neigh, lladdr, new, flags, 0);
787 /* report ndisc ops about neighbour update */
788 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
789}
790
791static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
792{
793 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
794 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
795 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
796 u8 *lladdr = NULL;
797 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
798 offsetof(struct nd_msg, opt));
799 struct ndisc_options ndopts;
800 struct net_device *dev = skb->dev;
801 struct inet6_ifaddr *ifp;
802 struct inet6_dev *idev = NULL;
803 struct neighbour *neigh;
804 int dad = ipv6_addr_any(saddr);
805 int is_router = -1;
806 SKB_DR(reason);
807 u64 nonce = 0;
808 bool inc;
809
810 if (skb->len < sizeof(struct nd_msg))
811 return SKB_DROP_REASON_PKT_TOO_SMALL;
812
813 if (ipv6_addr_is_multicast(&msg->target)) {
814 ND_PRINTK(2, warn, "NS: multicast target address\n");
815 return reason;
816 }
817
818 /*
819 * RFC2461 7.1.1:
820 * DAD has to be destined for solicited node multicast address.
821 */
822 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
823 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
824 return reason;
825 }
826
827 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
828 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
829
830 if (ndopts.nd_opts_src_lladdr) {
831 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
832 if (!lladdr) {
833 ND_PRINTK(2, warn,
834 "NS: invalid link-layer address length\n");
835 return reason;
836 }
837
838 /* RFC2461 7.1.1:
839 * If the IP source address is the unspecified address,
840 * there MUST NOT be source link-layer address option
841 * in the message.
842 */
843 if (dad) {
844 ND_PRINTK(2, warn,
845 "NS: bad DAD packet (link-layer address option)\n");
846 return reason;
847 }
848 }
849 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
850 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
851
852 inc = ipv6_addr_is_multicast(daddr);
853
854 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
855 if (ifp) {
856have_ifp:
857 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
858 if (dad) {
859 if (nonce != 0 && ifp->dad_nonce == nonce) {
860 u8 *np = (u8 *)&nonce;
861 /* Matching nonce if looped back */
862 ND_PRINTK(2, notice,
863 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
864 ifp->idev->dev->name,
865 &ifp->addr, np);
866 goto out;
867 }
868 /*
869 * We are colliding with another node
870 * who is doing DAD
871 * so fail our DAD process
872 */
873 addrconf_dad_failure(skb, ifp);
874 return reason;
875 } else {
876 /*
877 * This is not a dad solicitation.
878 * If we are an optimistic node,
879 * we should respond.
880 * Otherwise, we should ignore it.
881 */
882 if (!(ifp->flags & IFA_F_OPTIMISTIC))
883 goto out;
884 }
885 }
886
887 idev = ifp->idev;
888 } else {
889 struct net *net = dev_net(dev);
890
891 /* perhaps an address on the master device */
892 if (netif_is_l3_slave(dev)) {
893 struct net_device *mdev;
894
895 mdev = netdev_master_upper_dev_get_rcu(dev);
896 if (mdev) {
897 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
898 if (ifp)
899 goto have_ifp;
900 }
901 }
902
903 idev = in6_dev_get(dev);
904 if (!idev) {
905 /* XXX: count this drop? */
906 return reason;
907 }
908
909 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
910 (READ_ONCE(idev->cnf.forwarding) &&
911 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) ||
912 READ_ONCE(idev->cnf.proxy_ndp)) &&
913 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
914 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
915 skb->pkt_type != PACKET_HOST &&
916 inc &&
917 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
918 /*
919 * for anycast or proxy,
920 * sender should delay its response
921 * by a random time between 0 and
922 * MAX_ANYCAST_DELAY_TIME seconds.
923 * (RFC2461) -- yoshfuji
924 */
925 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
926 if (n)
927 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
928 goto out;
929 }
930 } else {
931 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST);
932 goto out;
933 }
934 }
935
936 if (is_router < 0)
937 is_router = READ_ONCE(idev->cnf.forwarding);
938
939 if (dad) {
940 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
941 !!is_router, false, (ifp != NULL), true);
942 goto out;
943 }
944
945 if (inc)
946 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
947 else
948 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
949
950 /*
951 * update / create cache entry
952 * for the source address
953 */
954 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
955 !inc || lladdr || !dev->addr_len);
956 if (neigh)
957 ndisc_update(dev, neigh, lladdr, NUD_STALE,
958 NEIGH_UPDATE_F_WEAK_OVERRIDE|
959 NEIGH_UPDATE_F_OVERRIDE,
960 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
961 if (neigh || !dev->header_ops) {
962 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
963 true, (ifp != NULL && inc), inc);
964 if (neigh)
965 neigh_release(neigh);
966 reason = SKB_CONSUMED;
967 }
968
969out:
970 if (ifp)
971 in6_ifa_put(ifp);
972 else
973 in6_dev_put(idev);
974 return reason;
975}
976
977static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
978{
979 struct inet6_dev *idev = __in6_dev_get(dev);
980
981 switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
982 case 0: /* Don't accept untracked na (absent in neighbor cache) */
983 return 0;
984 case 1: /* Create new entries from na if currently untracked */
985 return 1;
986 case 2: /* Create new entries from untracked na only if saddr is in the
987 * same subnet as an address configured on the interface that
988 * received the na
989 */
990 return !!ipv6_chk_prefix(saddr, dev);
991 default:
992 return 0;
993 }
994}
995
996static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
997{
998 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
999 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1000 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
1001 u8 *lladdr = NULL;
1002 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1003 offsetof(struct nd_msg, opt));
1004 struct ndisc_options ndopts;
1005 struct net_device *dev = skb->dev;
1006 struct inet6_dev *idev = __in6_dev_get(dev);
1007 struct inet6_ifaddr *ifp;
1008 struct neighbour *neigh;
1009 SKB_DR(reason);
1010 u8 new_state;
1011
1012 if (skb->len < sizeof(struct nd_msg))
1013 return SKB_DROP_REASON_PKT_TOO_SMALL;
1014
1015 if (ipv6_addr_is_multicast(&msg->target)) {
1016 ND_PRINTK(2, warn, "NA: target address is multicast\n");
1017 return reason;
1018 }
1019
1020 if (ipv6_addr_is_multicast(daddr) &&
1021 msg->icmph.icmp6_solicited) {
1022 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
1023 return reason;
1024 }
1025
1026 /* For some 802.11 wireless deployments (and possibly other networks),
1027 * there will be a NA proxy and unsolicitd packets are attacks
1028 * and thus should not be accepted.
1029 * drop_unsolicited_na takes precedence over accept_untracked_na
1030 */
1031 if (!msg->icmph.icmp6_solicited && idev &&
1032 READ_ONCE(idev->cnf.drop_unsolicited_na))
1033 return reason;
1034
1035 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
1036 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1037
1038 if (ndopts.nd_opts_tgt_lladdr) {
1039 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1040 if (!lladdr) {
1041 ND_PRINTK(2, warn,
1042 "NA: invalid link-layer address length\n");
1043 return reason;
1044 }
1045 }
1046 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1047 if (ifp) {
1048 if (skb->pkt_type != PACKET_LOOPBACK
1049 && (ifp->flags & IFA_F_TENTATIVE)) {
1050 addrconf_dad_failure(skb, ifp);
1051 return reason;
1052 }
1053 /* What should we make now? The advertisement
1054 is invalid, but ndisc specs say nothing
1055 about it. It could be misconfiguration, or
1056 an smart proxy agent tries to help us :-)
1057
1058 We should not print the error if NA has been
1059 received from loopback - it is just our own
1060 unsolicited advertisement.
1061 */
1062 if (skb->pkt_type != PACKET_LOOPBACK)
1063 ND_PRINTK(1, warn,
1064 "NA: %pM advertised our address %pI6c on %s!\n",
1065 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1066 in6_ifa_put(ifp);
1067 return reason;
1068 }
1069
1070 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1071
1072 /* RFC 9131 updates original Neighbour Discovery RFC 4861.
1073 * NAs with Target LL Address option without a corresponding
1074 * entry in the neighbour cache can now create a STALE neighbour
1075 * cache entry on routers.
1076 *
1077 * entry accept fwding solicited behaviour
1078 * ------- ------ ------ --------- ----------------------
1079 * present X X 0 Set state to STALE
1080 * present X X 1 Set state to REACHABLE
1081 * absent 0 X X Do nothing
1082 * absent 1 0 X Do nothing
1083 * absent 1 1 X Add a new STALE entry
1084 *
1085 * Note that we don't do a (daddr == all-routers-mcast) check.
1086 */
1087 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1088 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) {
1089 if (accept_untracked_na(dev, saddr)) {
1090 neigh = neigh_create(&nd_tbl, &msg->target, dev);
1091 new_state = NUD_STALE;
1092 }
1093 }
1094
1095 if (neigh && !IS_ERR(neigh)) {
1096 u8 old_flags = neigh->flags;
1097 struct net *net = dev_net(dev);
1098
1099 if (READ_ONCE(neigh->nud_state) & NUD_FAILED)
1100 goto out;
1101
1102 /*
1103 * Don't update the neighbor cache entry on a proxy NA from
1104 * ourselves because either the proxied node is off link or it
1105 * has already sent a NA to us.
1106 */
1107 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1108 READ_ONCE(net->ipv6.devconf_all->forwarding) &&
1109 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
1110 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1111 /* XXX: idev->cnf.proxy_ndp */
1112 goto out;
1113 }
1114
1115 ndisc_update(dev, neigh, lladdr,
1116 new_state,
1117 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1118 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1119 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1120 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1121 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1122
1123 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1124 /*
1125 * Change: router to host
1126 */
1127 rt6_clean_tohost(dev_net(dev), saddr);
1128 }
1129 reason = SKB_CONSUMED;
1130out:
1131 neigh_release(neigh);
1132 }
1133 return reason;
1134}
1135
1136static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
1137{
1138 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1139 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1140 struct neighbour *neigh;
1141 struct inet6_dev *idev;
1142 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1143 struct ndisc_options ndopts;
1144 u8 *lladdr = NULL;
1145 SKB_DR(reason);
1146
1147 if (skb->len < sizeof(*rs_msg))
1148 return SKB_DROP_REASON_PKT_TOO_SMALL;
1149
1150 idev = __in6_dev_get(skb->dev);
1151 if (!idev) {
1152 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1153 return reason;
1154 }
1155
1156 /* Don't accept RS if we're not in router mode */
1157 if (!READ_ONCE(idev->cnf.forwarding))
1158 goto out;
1159
1160 /*
1161 * Don't update NCE if src = ::;
1162 * this implies that the source node has no ip address assigned yet.
1163 */
1164 if (ipv6_addr_any(saddr))
1165 goto out;
1166
1167 /* Parse ND options */
1168 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts))
1169 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1170
1171 if (ndopts.nd_opts_src_lladdr) {
1172 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1173 skb->dev);
1174 if (!lladdr)
1175 goto out;
1176 }
1177
1178 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1179 if (neigh) {
1180 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1181 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1182 NEIGH_UPDATE_F_OVERRIDE|
1183 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1184 NDISC_ROUTER_SOLICITATION, &ndopts);
1185 neigh_release(neigh);
1186 reason = SKB_CONSUMED;
1187 }
1188out:
1189 return reason;
1190}
1191
1192static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1193{
1194 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1195 struct sk_buff *skb;
1196 struct nlmsghdr *nlh;
1197 struct nduseroptmsg *ndmsg;
1198 struct net *net = dev_net(ra->dev);
1199 int err;
1200 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1201 + (opt->nd_opt_len << 3));
1202 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1203
1204 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1205 if (!skb) {
1206 err = -ENOBUFS;
1207 goto errout;
1208 }
1209
1210 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1211 if (!nlh) {
1212 goto nla_put_failure;
1213 }
1214
1215 ndmsg = nlmsg_data(nlh);
1216 ndmsg->nduseropt_family = AF_INET6;
1217 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1218 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1219 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1220 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1221
1222 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1223
1224 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1225 goto nla_put_failure;
1226 nlmsg_end(skb, nlh);
1227
1228 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1229 return;
1230
1231nla_put_failure:
1232 nlmsg_free(skb);
1233 err = -EMSGSIZE;
1234errout:
1235 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1236}
1237
1238static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
1239{
1240 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1241 bool send_ifinfo_notify = false;
1242 struct neighbour *neigh = NULL;
1243 struct ndisc_options ndopts;
1244 struct fib6_info *rt = NULL;
1245 struct inet6_dev *in6_dev;
1246 struct fib6_table *table;
1247 u32 defrtr_usr_metric;
1248 unsigned int pref = 0;
1249 __u32 old_if_flags;
1250 struct net *net;
1251 SKB_DR(reason);
1252 int lifetime;
1253 int optlen;
1254
1255 __u8 *opt = (__u8 *)(ra_msg + 1);
1256
1257 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1258 sizeof(struct ra_msg);
1259
1260 ND_PRINTK(2, info,
1261 "RA: %s, dev: %s\n",
1262 __func__, skb->dev->name);
1263 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1264 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1265 return reason;
1266 }
1267 if (optlen < 0)
1268 return SKB_DROP_REASON_PKT_TOO_SMALL;
1269
1270#ifdef CONFIG_IPV6_NDISC_NODETYPE
1271 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1272 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1273 return reason;
1274 }
1275#endif
1276
1277 in6_dev = __in6_dev_get(skb->dev);
1278 if (!in6_dev) {
1279 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1280 skb->dev->name);
1281 return reason;
1282 }
1283
1284 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
1285 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1286
1287 if (!ipv6_accept_ra(in6_dev)) {
1288 ND_PRINTK(2, info,
1289 "RA: %s, did not accept ra for dev: %s\n",
1290 __func__, skb->dev->name);
1291 goto skip_linkparms;
1292 }
1293
1294#ifdef CONFIG_IPV6_NDISC_NODETYPE
1295 /* skip link-specific parameters from interior routers */
1296 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1297 ND_PRINTK(2, info,
1298 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1299 __func__, skb->dev->name);
1300 goto skip_linkparms;
1301 }
1302#endif
1303
1304 if (in6_dev->if_flags & IF_RS_SENT) {
1305 /*
1306 * flag that an RA was received after an RS was sent
1307 * out on this interface.
1308 */
1309 in6_dev->if_flags |= IF_RA_RCVD;
1310 }
1311
1312 /*
1313 * Remember the managed/otherconf flags from most recently
1314 * received RA message (RFC 2462) -- yoshfuji
1315 */
1316 old_if_flags = in6_dev->if_flags;
1317 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1318 IF_RA_OTHERCONF)) |
1319 (ra_msg->icmph.icmp6_addrconf_managed ?
1320 IF_RA_MANAGED : 0) |
1321 (ra_msg->icmph.icmp6_addrconf_other ?
1322 IF_RA_OTHERCONF : 0);
1323
1324 if (old_if_flags != in6_dev->if_flags)
1325 send_ifinfo_notify = true;
1326
1327 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) {
1328 ND_PRINTK(2, info,
1329 "RA: %s, defrtr is false for dev: %s\n",
1330 __func__, skb->dev->name);
1331 goto skip_defrtr;
1332 }
1333
1334 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1335 if (lifetime != 0 &&
1336 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) {
1337 ND_PRINTK(2, info,
1338 "RA: router lifetime (%ds) is too short: %s\n",
1339 lifetime, skb->dev->name);
1340 goto skip_defrtr;
1341 }
1342
1343 /* Do not accept RA with source-addr found on local machine unless
1344 * accept_ra_from_local is set to true.
1345 */
1346 net = dev_net(in6_dev->dev);
1347 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1348 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1349 ND_PRINTK(2, info,
1350 "RA from local address detected on dev: %s: default router ignored\n",
1351 skb->dev->name);
1352 goto skip_defrtr;
1353 }
1354
1355#ifdef CONFIG_IPV6_ROUTER_PREF
1356 pref = ra_msg->icmph.icmp6_router_pref;
1357 /* 10b is handled as if it were 00b (medium) */
1358 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1359 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref))
1360 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1361#endif
1362 /* routes added from RAs do not use nexthop objects */
1363 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1364 if (rt) {
1365 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1366 rt->fib6_nh->fib_nh_dev, NULL,
1367 &ipv6_hdr(skb)->saddr);
1368 if (!neigh) {
1369 ND_PRINTK(0, err,
1370 "RA: %s got default router without neighbour\n",
1371 __func__);
1372 fib6_info_release(rt);
1373 return reason;
1374 }
1375 }
1376 /* Set default route metric as specified by user */
1377 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1378 /* delete the route if lifetime is 0 or if metric needs change */
1379 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1380 ip6_del_rt(net, rt, false);
1381 rt = NULL;
1382 }
1383
1384 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
1385 rt, lifetime, defrtr_usr_metric, skb->dev->name);
1386 if (!rt && lifetime) {
1387 ND_PRINTK(3, info, "RA: adding default router\n");
1388
1389 if (neigh)
1390 neigh_release(neigh);
1391
1392 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1393 skb->dev, pref, defrtr_usr_metric,
1394 lifetime);
1395 if (!rt) {
1396 ND_PRINTK(0, err,
1397 "RA: %s failed to add default route\n",
1398 __func__);
1399 return reason;
1400 }
1401
1402 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1403 rt->fib6_nh->fib_nh_dev, NULL,
1404 &ipv6_hdr(skb)->saddr);
1405 if (!neigh) {
1406 ND_PRINTK(0, err,
1407 "RA: %s got default router without neighbour\n",
1408 __func__);
1409 fib6_info_release(rt);
1410 return reason;
1411 }
1412 neigh->flags |= NTF_ROUTER;
1413 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1414 struct nl_info nlinfo = {
1415 .nl_net = net,
1416 };
1417 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1418 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
1419 }
1420
1421 if (rt) {
1422 table = rt->fib6_table;
1423 spin_lock_bh(&table->tb6_lock);
1424
1425 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1426 fib6_add_gc_list(rt);
1427
1428 spin_unlock_bh(&table->tb6_lock);
1429 }
1430 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 &&
1431 ra_msg->icmph.icmp6_hop_limit) {
1432 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <=
1433 ra_msg->icmph.icmp6_hop_limit) {
1434 WRITE_ONCE(in6_dev->cnf.hop_limit,
1435 ra_msg->icmph.icmp6_hop_limit);
1436 fib6_metric_set(rt, RTAX_HOPLIMIT,
1437 ra_msg->icmph.icmp6_hop_limit);
1438 } else {
1439 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1440 }
1441 }
1442
1443skip_defrtr:
1444
1445 /*
1446 * Update Reachable Time and Retrans Timer
1447 */
1448
1449 if (in6_dev->nd_parms) {
1450 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1451
1452 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1453 rtime = (rtime*HZ)/1000;
1454 if (rtime < HZ/100)
1455 rtime = HZ/100;
1456 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1457 in6_dev->tstamp = jiffies;
1458 send_ifinfo_notify = true;
1459 }
1460
1461 rtime = ntohl(ra_msg->reachable_time);
1462 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1463 rtime = (rtime*HZ)/1000;
1464
1465 if (rtime < HZ/10)
1466 rtime = HZ/10;
1467
1468 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1469 NEIGH_VAR_SET(in6_dev->nd_parms,
1470 BASE_REACHABLE_TIME, rtime);
1471 NEIGH_VAR_SET(in6_dev->nd_parms,
1472 GC_STALETIME, 3 * rtime);
1473 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1474 in6_dev->tstamp = jiffies;
1475 send_ifinfo_notify = true;
1476 }
1477 }
1478 }
1479
1480skip_linkparms:
1481
1482 /*
1483 * Process options.
1484 */
1485
1486 if (!neigh)
1487 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1488 skb->dev, 1);
1489 if (neigh) {
1490 u8 *lladdr = NULL;
1491 if (ndopts.nd_opts_src_lladdr) {
1492 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1493 skb->dev);
1494 if (!lladdr) {
1495 ND_PRINTK(2, warn,
1496 "RA: invalid link-layer address length\n");
1497 goto out;
1498 }
1499 }
1500 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1501 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1502 NEIGH_UPDATE_F_OVERRIDE|
1503 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1504 NEIGH_UPDATE_F_ISROUTER,
1505 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1506 reason = SKB_CONSUMED;
1507 }
1508
1509 if (!ipv6_accept_ra(in6_dev)) {
1510 ND_PRINTK(2, info,
1511 "RA: %s, accept_ra is false for dev: %s\n",
1512 __func__, skb->dev->name);
1513 goto out;
1514 }
1515
1516#ifdef CONFIG_IPV6_ROUTE_INFO
1517 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1518 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1519 in6_dev->dev, 0)) {
1520 ND_PRINTK(2, info,
1521 "RA from local address detected on dev: %s: router info ignored.\n",
1522 skb->dev->name);
1523 goto skip_routeinfo;
1524 }
1525
1526 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) {
1527 struct nd_opt_hdr *p;
1528 for (p = ndopts.nd_opts_ri;
1529 p;
1530 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1531 struct route_info *ri = (struct route_info *)p;
1532#ifdef CONFIG_IPV6_NDISC_NODETYPE
1533 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1534 ri->prefix_len == 0)
1535 continue;
1536#endif
1537 if (ri->prefix_len == 0 &&
1538 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr))
1539 continue;
1540 if (ri->lifetime != 0 &&
1541 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft))
1542 continue;
1543 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen))
1544 continue;
1545 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen))
1546 continue;
1547 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1548 &ipv6_hdr(skb)->saddr);
1549 }
1550 }
1551
1552skip_routeinfo:
1553#endif
1554
1555#ifdef CONFIG_IPV6_NDISC_NODETYPE
1556 /* skip link-specific ndopts from interior routers */
1557 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1558 ND_PRINTK(2, info,
1559 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1560 __func__, skb->dev->name);
1561 goto out;
1562 }
1563#endif
1564
1565 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) {
1566 struct nd_opt_hdr *p;
1567 for (p = ndopts.nd_opts_pi;
1568 p;
1569 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1570 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1571 (p->nd_opt_len) << 3,
1572 ndopts.nd_opts_src_lladdr != NULL);
1573 }
1574 }
1575
1576 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) {
1577 __be32 n;
1578 u32 mtu;
1579
1580 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1581 mtu = ntohl(n);
1582
1583 if (in6_dev->ra_mtu != mtu) {
1584 in6_dev->ra_mtu = mtu;
1585 send_ifinfo_notify = true;
1586 }
1587
1588 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1589 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1590 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) {
1591 WRITE_ONCE(in6_dev->cnf.mtu6, mtu);
1592 fib6_metric_set(rt, RTAX_MTU, mtu);
1593 rt6_mtu_change(skb->dev, mtu);
1594 }
1595 }
1596
1597 if (ndopts.nd_useropts) {
1598 struct nd_opt_hdr *p;
1599 for (p = ndopts.nd_useropts;
1600 p;
1601 p = ndisc_next_useropt(skb->dev, p,
1602 ndopts.nd_useropts_end)) {
1603 ndisc_ra_useropt(skb, p);
1604 }
1605 }
1606
1607 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1608 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1609 }
1610out:
1611 /* Send a notify if RA changed managed/otherconf flags or
1612 * timer settings or ra_mtu value
1613 */
1614 if (send_ifinfo_notify)
1615 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1616
1617 fib6_info_release(rt);
1618 if (neigh)
1619 neigh_release(neigh);
1620 return reason;
1621}
1622
1623static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
1624{
1625 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1626 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1627 offsetof(struct rd_msg, opt));
1628 struct ndisc_options ndopts;
1629 SKB_DR(reason);
1630 u8 *hdr;
1631
1632#ifdef CONFIG_IPV6_NDISC_NODETYPE
1633 switch (skb->ndisc_nodetype) {
1634 case NDISC_NODETYPE_HOST:
1635 case NDISC_NODETYPE_NODEFAULT:
1636 ND_PRINTK(2, warn,
1637 "Redirect: from host or unauthorized router\n");
1638 return reason;
1639 }
1640#endif
1641
1642 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1643 ND_PRINTK(2, warn,
1644 "Redirect: source address is not link-local\n");
1645 return reason;
1646 }
1647
1648 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1649 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1650
1651 if (!ndopts.nd_opts_rh) {
1652 ip6_redirect_no_header(skb, dev_net(skb->dev),
1653 skb->dev->ifindex);
1654 return reason;
1655 }
1656
1657 hdr = (u8 *)ndopts.nd_opts_rh;
1658 hdr += 8;
1659 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1660 return SKB_DROP_REASON_PKT_TOO_SMALL;
1661
1662 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1663}
1664
1665static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1666 struct sk_buff *orig_skb,
1667 int rd_len)
1668{
1669 u8 *opt = skb_put(skb, rd_len);
1670
1671 memset(opt, 0, 8);
1672 *(opt++) = ND_OPT_REDIRECT_HDR;
1673 *(opt++) = (rd_len >> 3);
1674 opt += 6;
1675
1676 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1677 rd_len - 8);
1678}
1679
1680void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1681{
1682 struct net_device *dev = skb->dev;
1683 struct net *net = dev_net_rcu(dev);
1684 struct sock *sk = net->ipv6.ndisc_sk;
1685 int optlen = 0;
1686 struct inet_peer *peer;
1687 struct sk_buff *buff;
1688 struct rd_msg *msg;
1689 struct in6_addr saddr_buf;
1690 struct rt6_info *rt;
1691 struct dst_entry *dst;
1692 struct flowi6 fl6;
1693 int rd_len;
1694 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1695 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1696 bool ret;
1697
1698 if (netif_is_l3_master(dev)) {
1699 dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
1700 if (!dev)
1701 return;
1702 }
1703
1704 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1705 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1706 dev->name);
1707 return;
1708 }
1709
1710 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1711 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1712 ND_PRINTK(2, warn,
1713 "Redirect: target address is not link-local unicast\n");
1714 return;
1715 }
1716
1717 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1718 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1719
1720 dst = ip6_route_output(net, NULL, &fl6);
1721 if (dst->error) {
1722 dst_release(dst);
1723 return;
1724 }
1725 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1726 if (IS_ERR(dst))
1727 return;
1728
1729 rt = dst_rt6_info(dst);
1730
1731 if (rt->rt6i_flags & RTF_GATEWAY) {
1732 ND_PRINTK(2, warn,
1733 "Redirect: destination is not a neighbour\n");
1734 goto release;
1735 }
1736
1737 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr);
1738 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1739
1740 if (!ret)
1741 goto release;
1742
1743 if (dev->addr_len) {
1744 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1745 if (!neigh) {
1746 ND_PRINTK(2, warn,
1747 "Redirect: no neigh for target address\n");
1748 goto release;
1749 }
1750
1751 read_lock_bh(&neigh->lock);
1752 if (neigh->nud_state & NUD_VALID) {
1753 memcpy(ha_buf, neigh->ha, dev->addr_len);
1754 read_unlock_bh(&neigh->lock);
1755 ha = ha_buf;
1756 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1757 ops_data_buf,
1758 &ops_data);
1759 } else
1760 read_unlock_bh(&neigh->lock);
1761
1762 neigh_release(neigh);
1763 }
1764
1765 rd_len = min_t(unsigned int,
1766 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1767 skb->len + 8);
1768 rd_len &= ~0x7;
1769 optlen += rd_len;
1770
1771 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1772 if (!buff)
1773 goto release;
1774
1775 msg = skb_put(buff, sizeof(*msg));
1776 *msg = (struct rd_msg) {
1777 .icmph = {
1778 .icmp6_type = NDISC_REDIRECT,
1779 },
1780 .target = *target,
1781 .dest = ipv6_hdr(skb)->daddr,
1782 };
1783
1784 /*
1785 * include target_address option
1786 */
1787
1788 if (ha)
1789 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1790
1791 /*
1792 * build redirect option and copy skb over to the new packet.
1793 */
1794
1795 if (rd_len)
1796 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1797
1798 skb_dst_set(buff, dst);
1799 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1800 return;
1801
1802release:
1803 dst_release(dst);
1804}
1805
1806static void pndisc_redo(struct sk_buff *skb)
1807{
1808 enum skb_drop_reason reason = ndisc_recv_ns(skb);
1809
1810 kfree_skb_reason(skb, reason);
1811}
1812
1813static int ndisc_is_multicast(const void *pkey)
1814{
1815 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1816}
1817
1818static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1819{
1820 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1821
1822 if (!idev)
1823 return true;
1824 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1825 READ_ONCE(idev->cnf.suppress_frag_ndisc)) {
1826 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1827 return true;
1828 }
1829 return false;
1830}
1831
1832enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
1833{
1834 struct nd_msg *msg;
1835 SKB_DR(reason);
1836
1837 if (ndisc_suppress_frag_ndisc(skb))
1838 return SKB_DROP_REASON_IPV6_NDISC_FRAG;
1839
1840 if (skb_linearize(skb))
1841 return SKB_DROP_REASON_NOMEM;
1842
1843 msg = (struct nd_msg *)skb_transport_header(skb);
1844
1845 __skb_push(skb, skb->data - skb_transport_header(skb));
1846
1847 if (ipv6_hdr(skb)->hop_limit != 255) {
1848 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1849 ipv6_hdr(skb)->hop_limit);
1850 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT;
1851 }
1852
1853 if (msg->icmph.icmp6_code != 0) {
1854 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1855 msg->icmph.icmp6_code);
1856 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE;
1857 }
1858
1859 switch (msg->icmph.icmp6_type) {
1860 case NDISC_NEIGHBOUR_SOLICITATION:
1861 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1862 reason = ndisc_recv_ns(skb);
1863 break;
1864
1865 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1866 reason = ndisc_recv_na(skb);
1867 break;
1868
1869 case NDISC_ROUTER_SOLICITATION:
1870 reason = ndisc_recv_rs(skb);
1871 break;
1872
1873 case NDISC_ROUTER_ADVERTISEMENT:
1874 reason = ndisc_router_discovery(skb);
1875 break;
1876
1877 case NDISC_REDIRECT:
1878 reason = ndisc_redirect_rcv(skb);
1879 break;
1880 }
1881
1882 return reason;
1883}
1884
1885static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1886{
1887 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1888 struct netdev_notifier_change_info *change_info;
1889 struct net *net = dev_net(dev);
1890 struct inet6_dev *idev;
1891 bool evict_nocarrier;
1892
1893 switch (event) {
1894 case NETDEV_CHANGEADDR:
1895 neigh_changeaddr(&nd_tbl, dev);
1896 fib6_run_gc(0, net, false);
1897 fallthrough;
1898 case NETDEV_UP:
1899 idev = in6_dev_get(dev);
1900 if (!idev)
1901 break;
1902 if (READ_ONCE(idev->cnf.ndisc_notify) ||
1903 READ_ONCE(net->ipv6.devconf_all->ndisc_notify))
1904 ndisc_send_unsol_na(dev);
1905 in6_dev_put(idev);
1906 break;
1907 case NETDEV_CHANGE:
1908 idev = in6_dev_get(dev);
1909 if (!idev)
1910 evict_nocarrier = true;
1911 else {
1912 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) &&
1913 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier);
1914 in6_dev_put(idev);
1915 }
1916
1917 change_info = ptr;
1918 if (change_info->flags_changed & IFF_NOARP)
1919 neigh_changeaddr(&nd_tbl, dev);
1920 if (evict_nocarrier && !netif_carrier_ok(dev))
1921 neigh_carrier_down(&nd_tbl, dev);
1922 break;
1923 case NETDEV_DOWN:
1924 neigh_ifdown(&nd_tbl, dev);
1925 fib6_run_gc(0, net, false);
1926 break;
1927 case NETDEV_NOTIFY_PEERS:
1928 ndisc_send_unsol_na(dev);
1929 break;
1930 default:
1931 break;
1932 }
1933
1934 return NOTIFY_DONE;
1935}
1936
1937static struct notifier_block ndisc_netdev_notifier = {
1938 .notifier_call = ndisc_netdev_event,
1939 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1940};
1941
1942#ifdef CONFIG_SYSCTL
1943static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl,
1944 const char *func, const char *dev_name)
1945{
1946 static char warncomm[TASK_COMM_LEN];
1947 static int warned;
1948 if (strcmp(warncomm, current->comm) && warned < 5) {
1949 strscpy(warncomm, current->comm);
1950 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1951 warncomm, func,
1952 dev_name, ctl->procname,
1953 dev_name, ctl->procname);
1954 warned++;
1955 }
1956}
1957
1958int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer,
1959 size_t *lenp, loff_t *ppos)
1960{
1961 struct net_device *dev = ctl->extra1;
1962 struct inet6_dev *idev;
1963 int ret;
1964
1965 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1966 (strcmp(ctl->procname, "base_reachable_time") == 0))
1967 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1968
1969 if (strcmp(ctl->procname, "retrans_time") == 0)
1970 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1971
1972 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1973 ret = neigh_proc_dointvec_jiffies(ctl, write,
1974 buffer, lenp, ppos);
1975
1976 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1977 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1978 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1979 buffer, lenp, ppos);
1980 else
1981 ret = -1;
1982
1983 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1984 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1985 idev->nd_parms->reachable_time =
1986 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1987 WRITE_ONCE(idev->tstamp, jiffies);
1988 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1989 in6_dev_put(idev);
1990 }
1991 return ret;
1992}
1993
1994
1995#endif
1996
1997static int __net_init ndisc_net_init(struct net *net)
1998{
1999 struct ipv6_pinfo *np;
2000 struct sock *sk;
2001 int err;
2002
2003 err = inet_ctl_sock_create(&sk, PF_INET6,
2004 SOCK_RAW, IPPROTO_ICMPV6, net);
2005 if (err < 0) {
2006 ND_PRINTK(0, err,
2007 "NDISC: Failed to initialize the control socket (err %d)\n",
2008 err);
2009 return err;
2010 }
2011
2012 net->ipv6.ndisc_sk = sk;
2013
2014 np = inet6_sk(sk);
2015 np->hop_limit = 255;
2016 /* Do not loopback ndisc messages */
2017 inet6_clear_bit(MC6_LOOP, sk);
2018
2019 return 0;
2020}
2021
2022static void __net_exit ndisc_net_exit(struct net *net)
2023{
2024 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
2025}
2026
2027static struct pernet_operations ndisc_net_ops = {
2028 .init = ndisc_net_init,
2029 .exit = ndisc_net_exit,
2030};
2031
2032int __init ndisc_init(void)
2033{
2034 int err;
2035
2036 err = register_pernet_subsys(&ndisc_net_ops);
2037 if (err)
2038 return err;
2039 /*
2040 * Initialize the neighbour table
2041 */
2042 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
2043
2044#ifdef CONFIG_SYSCTL
2045 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
2046 ndisc_ifinfo_sysctl_change);
2047 if (err)
2048 goto out_unregister_pernet;
2049out:
2050#endif
2051 return err;
2052
2053#ifdef CONFIG_SYSCTL
2054out_unregister_pernet:
2055 unregister_pernet_subsys(&ndisc_net_ops);
2056 goto out;
2057#endif
2058}
2059
2060int __init ndisc_late_init(void)
2061{
2062 return register_netdevice_notifier(&ndisc_netdev_notifier);
2063}
2064
2065void ndisc_late_cleanup(void)
2066{
2067 unregister_netdevice_notifier(&ndisc_netdev_notifier);
2068}
2069
2070void ndisc_cleanup(void)
2071{
2072#ifdef CONFIG_SYSCTL
2073 neigh_sysctl_unregister(&nd_tbl.parms);
2074#endif
2075 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
2076 unregister_pernet_subsys(&ndisc_net_ops);
2077}
Linux 6.x block layer and io_uring tree(s)