projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge tag 'for-f2fs-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk...
[deliverable/linux.git] / net / ipv6 / ndisc.c
1 /*
2 * Neighbour Discovery for IPv6
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 * Mike Shaver <shaver@ingenia.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
15 /*
16 * Changes:
17 *
18 * Alexey I. Froloff : RFC6106 (DNSSL) support
19 * Pierre Ynard : export userland ND options
20 * through netlink (RDNSS support)
21 * Lars Fenneberg : fixed MTU setting on receipt
22 * of an RA.
23 * Janos Farkas : kmalloc failure checks
24 * Alexey Kuznetsov : state machine reworked
25 * and moved to net/core.
26 * Pekka Savola : RFC2461 validation
27 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
28 */
29
30 #define pr_fmt(fmt) "ICMPv6: " fmt
31
32 #include <linux/module.h>
33 #include <linux/errno.h>
34 #include <linux/types.h>
35 #include <linux/socket.h>
36 #include <linux/sockios.h>
37 #include <linux/sched.h>
38 #include <linux/net.h>
39 #include <linux/in6.h>
40 #include <linux/route.h>
41 #include <linux/init.h>
42 #include <linux/rcupdate.h>
43 #include <linux/slab.h>
44 #ifdef CONFIG_SYSCTL
45 #include <linux/sysctl.h>
46 #endif
47
48 #include <linux/if_addr.h>
49 #include <linux/if_arp.h>
50 #include <linux/ipv6.h>
51 #include <linux/icmpv6.h>
52 #include <linux/jhash.h>
53
54 #include <net/sock.h>
55 #include <net/snmp.h>
56
57 #include <net/ipv6.h>
58 #include <net/protocol.h>
59 #include <net/ndisc.h>
60 #include <net/ip6_route.h>
61 #include <net/addrconf.h>
62 #include <net/icmp.h>
63
64 #include <net/netlink.h>
65 #include <linux/rtnetlink.h>
66
67 #include <net/flow.h>
68 #include <net/ip6_checksum.h>
69 #include <net/inet_common.h>
70 #include <net/l3mdev.h>
71 #include <linux/proc_fs.h>
72
73 #include <linux/netfilter.h>
74 #include <linux/netfilter_ipv6.h>
75
76 /* Set to 3 to get tracing... */
77 #define ND_DEBUG 1
78
79 #define ND_PRINTK(val, level, fmt, ...) \
80 do { \
81 if (val <= ND_DEBUG) \
82 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \
83 } while (0)
84
85 static u32 ndisc_hash(const void *pkey,
86 const struct net_device *dev,
87 __u32 *hash_rnd);
88 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
89 static int ndisc_constructor(struct neighbour *neigh);
90 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
91 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
92 static int pndisc_constructor(struct pneigh_entry *n);
93 static void pndisc_destructor(struct pneigh_entry *n);
94 static void pndisc_redo(struct sk_buff *skb);
95
96 static const struct neigh_ops ndisc_generic_ops = {
97 .family = AF_INET6,
98 .solicit = ndisc_solicit,
99 .error_report = ndisc_error_report,
100 .output = neigh_resolve_output,
101 .connected_output = neigh_connected_output,
102 };
103
104 static const struct neigh_ops ndisc_hh_ops = {
105 .family = AF_INET6,
106 .solicit = ndisc_solicit,
107 .error_report = ndisc_error_report,
108 .output = neigh_resolve_output,
109 .connected_output = neigh_resolve_output,
110 };
111
112
113 static const struct neigh_ops ndisc_direct_ops = {
114 .family = AF_INET6,
115 .output = neigh_direct_output,
116 .connected_output = neigh_direct_output,
117 };
118
119 struct neigh_table nd_tbl = {
120 .family = AF_INET6,
121 .key_len = sizeof(struct in6_addr),
122 .protocol = cpu_to_be16(ETH_P_IPV6),
123 .hash = ndisc_hash,
124 .key_eq = ndisc_key_eq,
125 .constructor = ndisc_constructor,
126 .pconstructor = pndisc_constructor,
127 .pdestructor = pndisc_destructor,
128 .proxy_redo = pndisc_redo,
129 .id = "ndisc_cache",
130 .parms = {
131 .tbl = &nd_tbl,
132 .reachable_time = ND_REACHABLE_TIME,
133 .data = {
134 [NEIGH_VAR_MCAST_PROBES] = 3,
135 [NEIGH_VAR_UCAST_PROBES] = 3,
136 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
137 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
138 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
139 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
140 [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024,
141 [NEIGH_VAR_PROXY_QLEN] = 64,
142 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
143 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
144 },
145 },
146 .gc_interval = 30 * HZ,
147 .gc_thresh1 = 128,
148 .gc_thresh2 = 512,
149 .gc_thresh3 = 1024,
150 };
151 EXPORT_SYMBOL_GPL(nd_tbl);
152
153 static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data)
154 {
155 int pad = ndisc_addr_option_pad(skb->dev->type);
156 int data_len = skb->dev->addr_len;
157 int space = ndisc_opt_addr_space(skb->dev);
158 u8 *opt = skb_put(skb, space);
159
160 opt[0] = type;
161 opt[1] = space>>3;
162
163 memset(opt + 2, 0, pad);
164 opt += pad;
165 space -= pad;
166
167 memcpy(opt+2, data, data_len);
168 data_len += 2;
169 opt += data_len;
170 space -= data_len;
171 if (space > 0)
172 memset(opt, 0, space);
173 }
174
175 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
176 struct nd_opt_hdr *end)
177 {
178 int type;
179 if (!cur || !end || cur >= end)
180 return NULL;
181 type = cur->nd_opt_type;
182 do {
183 cur = ((void *)cur) + (cur->nd_opt_len << 3);
184 } while (cur < end && cur->nd_opt_type != type);
185 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
186 }
187
188 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
189 {
190 return opt->nd_opt_type == ND_OPT_RDNSS ||
191 opt->nd_opt_type == ND_OPT_DNSSL;
192 }
193
194 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
195 struct nd_opt_hdr *end)
196 {
197 if (!cur || !end || cur >= end)
198 return NULL;
199 do {
200 cur = ((void *)cur) + (cur->nd_opt_len << 3);
201 } while (cur < end && !ndisc_is_useropt(cur));
202 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
203 }
204
205 struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
206 struct ndisc_options *ndopts)
207 {
208 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
209
210 if (!nd_opt || opt_len < 0 || !ndopts)
211 return NULL;
212 memset(ndopts, 0, sizeof(*ndopts));
213 while (opt_len) {
214 int l;
215 if (opt_len < sizeof(struct nd_opt_hdr))
216 return NULL;
217 l = nd_opt->nd_opt_len << 3;
218 if (opt_len < l || l == 0)
219 return NULL;
220 switch (nd_opt->nd_opt_type) {
221 case ND_OPT_SOURCE_LL_ADDR:
222 case ND_OPT_TARGET_LL_ADDR:
223 case ND_OPT_MTU:
224 case ND_OPT_REDIRECT_HDR:
225 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
226 ND_PRINTK(2, warn,
227 "%s: duplicated ND6 option found: type=%d\n",
228 __func__, nd_opt->nd_opt_type);
229 } else {
230 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
231 }
232 break;
233 case ND_OPT_PREFIX_INFO:
234 ndopts->nd_opts_pi_end = nd_opt;
235 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
236 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
237 break;
238 #ifdef CONFIG_IPV6_ROUTE_INFO
239 case ND_OPT_ROUTE_INFO:
240 ndopts->nd_opts_ri_end = nd_opt;
241 if (!ndopts->nd_opts_ri)
242 ndopts->nd_opts_ri = nd_opt;
243 break;
244 #endif
245 default:
246 if (ndisc_is_useropt(nd_opt)) {
247 ndopts->nd_useropts_end = nd_opt;
248 if (!ndopts->nd_useropts)
249 ndopts->nd_useropts = nd_opt;
250 } else {
251 /*
252 * Unknown options must be silently ignored,
253 * to accommodate future extension to the
254 * protocol.
255 */
256 ND_PRINTK(2, notice,
257 "%s: ignored unsupported option; type=%d, len=%d\n",
258 __func__,
259 nd_opt->nd_opt_type,
260 nd_opt->nd_opt_len);
261 }
262 }
263 opt_len -= l;
264 nd_opt = ((void *)nd_opt) + l;
265 }
266 return ndopts;
267 }
268
269 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
270 {
271 switch (dev->type) {
272 case ARPHRD_ETHER:
273 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
274 case ARPHRD_FDDI:
275 ipv6_eth_mc_map(addr, buf);
276 return 0;
277 case ARPHRD_ARCNET:
278 ipv6_arcnet_mc_map(addr, buf);
279 return 0;
280 case ARPHRD_INFINIBAND:
281 ipv6_ib_mc_map(addr, dev->broadcast, buf);
282 return 0;
283 case ARPHRD_IPGRE:
284 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
285 default:
286 if (dir) {
287 memcpy(buf, dev->broadcast, dev->addr_len);
288 return 0;
289 }
290 }
291 return -EINVAL;
292 }
293 EXPORT_SYMBOL(ndisc_mc_map);
294
295 static u32 ndisc_hash(const void *pkey,
296 const struct net_device *dev,
297 __u32 *hash_rnd)
298 {
299 return ndisc_hashfn(pkey, dev, hash_rnd);
300 }
301
302 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
303 {
304 return neigh_key_eq128(n, pkey);
305 }
306
307 static int ndisc_constructor(struct neighbour *neigh)
308 {
309 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
310 struct net_device *dev = neigh->dev;
311 struct inet6_dev *in6_dev;
312 struct neigh_parms *parms;
313 bool is_multicast = ipv6_addr_is_multicast(addr);
314
315 in6_dev = in6_dev_get(dev);
316 if (!in6_dev) {
317 return -EINVAL;
318 }
319
320 parms = in6_dev->nd_parms;
321 __neigh_parms_put(neigh->parms);
322 neigh->parms = neigh_parms_clone(parms);
323
324 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
325 if (!dev->header_ops) {
326 neigh->nud_state = NUD_NOARP;
327 neigh->ops = &ndisc_direct_ops;
328 neigh->output = neigh_direct_output;
329 } else {
330 if (is_multicast) {
331 neigh->nud_state = NUD_NOARP;
332 ndisc_mc_map(addr, neigh->ha, dev, 1);
333 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
334 neigh->nud_state = NUD_NOARP;
335 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
336 if (dev->flags&IFF_LOOPBACK)
337 neigh->type = RTN_LOCAL;
338 } else if (dev->flags&IFF_POINTOPOINT) {
339 neigh->nud_state = NUD_NOARP;
340 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
341 }
342 if (dev->header_ops->cache)
343 neigh->ops = &ndisc_hh_ops;
344 else
345 neigh->ops = &ndisc_generic_ops;
346 if (neigh->nud_state&NUD_VALID)
347 neigh->output = neigh->ops->connected_output;
348 else
349 neigh->output = neigh->ops->output;
350 }
351 in6_dev_put(in6_dev);
352 return 0;
353 }
354
355 static int pndisc_constructor(struct pneigh_entry *n)
356 {
357 struct in6_addr *addr = (struct in6_addr *)&n->key;
358 struct in6_addr maddr;
359 struct net_device *dev = n->dev;
360
361 if (!dev || !__in6_dev_get(dev))
362 return -EINVAL;
363 addrconf_addr_solict_mult(addr, &maddr);
364 ipv6_dev_mc_inc(dev, &maddr);
365 return 0;
366 }
367
368 static void pndisc_destructor(struct pneigh_entry *n)
369 {
370 struct in6_addr *addr = (struct in6_addr *)&n->key;
371 struct in6_addr maddr;
372 struct net_device *dev = n->dev;
373
374 if (!dev || !__in6_dev_get(dev))
375 return;
376 addrconf_addr_solict_mult(addr, &maddr);
377 ipv6_dev_mc_dec(dev, &maddr);
378 }
379
380 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
381 int len)
382 {
383 int hlen = LL_RESERVED_SPACE(dev);
384 int tlen = dev->needed_tailroom;
385 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
386 struct sk_buff *skb;
387
388 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
389 if (!skb) {
390 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
391 __func__);
392 return NULL;
393 }
394
395 skb->protocol = htons(ETH_P_IPV6);
396 skb->dev = dev;
397
398 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
399 skb_reset_transport_header(skb);
400
401 /* Manually assign socket ownership as we avoid calling
402 * sock_alloc_send_pskb() to bypass wmem buffer limits
403 */
404 skb_set_owner_w(skb, sk);
405
406 return skb;
407 }
408
409 static void ip6_nd_hdr(struct sk_buff *skb,
410 const struct in6_addr *saddr,
411 const struct in6_addr *daddr,
412 int hop_limit, int len)
413 {
414 struct ipv6hdr *hdr;
415
416 skb_push(skb, sizeof(*hdr));
417 skb_reset_network_header(skb);
418 hdr = ipv6_hdr(skb);
419
420 ip6_flow_hdr(hdr, 0, 0);
421
422 hdr->payload_len = htons(len);
423 hdr->nexthdr = IPPROTO_ICMPV6;
424 hdr->hop_limit = hop_limit;
425
426 hdr->saddr = *saddr;
427 hdr->daddr = *daddr;
428 }
429
430 static void ndisc_send_skb(struct sk_buff *skb,
431 const struct in6_addr *daddr,
432 const struct in6_addr *saddr)
433 {
434 struct dst_entry *dst = skb_dst(skb);
435 struct net *net = dev_net(skb->dev);
436 struct sock *sk = net->ipv6.ndisc_sk;
437 struct inet6_dev *idev;
438 int err;
439 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
440 u8 type;
441
442 type = icmp6h->icmp6_type;
443
444 if (!dst) {
445 struct flowi6 fl6;
446 int oif = l3mdev_fib_oif(skb->dev);
447
448 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
449 if (oif != skb->dev->ifindex)
450 fl6.flowi6_flags |= FLOWI_FLAG_L3MDEV_SRC;
451 dst = icmp6_dst_alloc(skb->dev, &fl6);
452 if (IS_ERR(dst)) {
453 kfree_skb(skb);
454 return;
455 }
456
457 skb_dst_set(skb, dst);
458 }
459
460 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
461 IPPROTO_ICMPV6,
462 csum_partial(icmp6h,
463 skb->len, 0));
464
465 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
466
467 rcu_read_lock();
468 idev = __in6_dev_get(dst->dev);
469 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
470
471 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
472 net, sk, skb, NULL, dst->dev,
473 dst_output);
474 if (!err) {
475 ICMP6MSGOUT_INC_STATS(net, idev, type);
476 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
477 }
478
479 rcu_read_unlock();
480 }
481
482 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
483 const struct in6_addr *solicited_addr,
484 bool router, bool solicited, bool override, bool inc_opt)
485 {
486 struct sk_buff *skb;
487 struct in6_addr tmpaddr;
488 struct inet6_ifaddr *ifp;
489 const struct in6_addr *src_addr;
490 struct nd_msg *msg;
491 int optlen = 0;
492
493 /* for anycast or proxy, solicited_addr != src_addr */
494 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
495 if (ifp) {
496 src_addr = solicited_addr;
497 if (ifp->flags & IFA_F_OPTIMISTIC)
498 override = false;
499 inc_opt |= ifp->idev->cnf.force_tllao;
500 in6_ifa_put(ifp);
501 } else {
502 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
503 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
504 &tmpaddr))
505 return;
506 src_addr = &tmpaddr;
507 }
508
509 if (!dev->addr_len)
510 inc_opt = 0;
511 if (inc_opt)
512 optlen += ndisc_opt_addr_space(dev);
513
514 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
515 if (!skb)
516 return;
517
518 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
519 *msg = (struct nd_msg) {
520 .icmph = {
521 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
522 .icmp6_router = router,
523 .icmp6_solicited = solicited,
524 .icmp6_override = override,
525 },
526 .target = *solicited_addr,
527 };
528
529 if (inc_opt)
530 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
531 dev->dev_addr);
532
533
534 ndisc_send_skb(skb, daddr, src_addr);
535 }
536
537 static void ndisc_send_unsol_na(struct net_device *dev)
538 {
539 struct inet6_dev *idev;
540 struct inet6_ifaddr *ifa;
541
542 idev = in6_dev_get(dev);
543 if (!idev)
544 return;
545
546 read_lock_bh(&idev->lock);
547 list_for_each_entry(ifa, &idev->addr_list, if_list) {
548 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
549 /*router=*/ !!idev->cnf.forwarding,
550 /*solicited=*/ false, /*override=*/ true,
551 /*inc_opt=*/ true);
552 }
553 read_unlock_bh(&idev->lock);
554
555 in6_dev_put(idev);
556 }
557
558 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
559 const struct in6_addr *daddr, const struct in6_addr *saddr)
560 {
561 struct sk_buff *skb;
562 struct in6_addr addr_buf;
563 int inc_opt = dev->addr_len;
564 int optlen = 0;
565 struct nd_msg *msg;
566
567 if (!saddr) {
568 if (ipv6_get_lladdr(dev, &addr_buf,
569 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
570 return;
571 saddr = &addr_buf;
572 }
573
574 if (ipv6_addr_any(saddr))
575 inc_opt = false;
576 if (inc_opt)
577 optlen += ndisc_opt_addr_space(dev);
578
579 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
580 if (!skb)
581 return;
582
583 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
584 *msg = (struct nd_msg) {
585 .icmph = {
586 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
587 },
588 .target = *solicit,
589 };
590
591 if (inc_opt)
592 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
593 dev->dev_addr);
594
595 ndisc_send_skb(skb, daddr, saddr);
596 }
597
598 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
599 const struct in6_addr *daddr)
600 {
601 struct sk_buff *skb;
602 struct rs_msg *msg;
603 int send_sllao = dev->addr_len;
604 int optlen = 0;
605
606 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
607 /*
608 * According to section 2.2 of RFC 4429, we must not
609 * send router solicitations with a sllao from
610 * optimistic addresses, but we may send the solicitation
611 * if we don't include the sllao. So here we check
612 * if our address is optimistic, and if so, we
613 * suppress the inclusion of the sllao.
614 */
615 if (send_sllao) {
616 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
617 dev, 1);
618 if (ifp) {
619 if (ifp->flags & IFA_F_OPTIMISTIC) {
620 send_sllao = 0;
621 }
622 in6_ifa_put(ifp);
623 } else {
624 send_sllao = 0;
625 }
626 }
627 #endif
628 if (send_sllao)
629 optlen += ndisc_opt_addr_space(dev);
630
631 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
632 if (!skb)
633 return;
634
635 msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
636 *msg = (struct rs_msg) {
637 .icmph = {
638 .icmp6_type = NDISC_ROUTER_SOLICITATION,
639 },
640 };
641
642 if (send_sllao)
643 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
644 dev->dev_addr);
645
646 ndisc_send_skb(skb, daddr, saddr);
647 }
648
649
650 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
651 {
652 /*
653 * "The sender MUST return an ICMP
654 * destination unreachable"
655 */
656 dst_link_failure(skb);
657 kfree_skb(skb);
658 }
659
660 /* Called with locked neigh: either read or both */
661
662 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
663 {
664 struct in6_addr *saddr = NULL;
665 struct in6_addr mcaddr;
666 struct net_device *dev = neigh->dev;
667 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
668 int probes = atomic_read(&neigh->probes);
669
670 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
671 dev, 1,
672 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
673 saddr = &ipv6_hdr(skb)->saddr;
674 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
675 if (probes < 0) {
676 if (!(neigh->nud_state & NUD_VALID)) {
677 ND_PRINTK(1, dbg,
678 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
679 __func__, target);
680 }
681 ndisc_send_ns(dev, target, target, saddr);
682 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
683 neigh_app_ns(neigh);
684 } else {
685 addrconf_addr_solict_mult(target, &mcaddr);
686 ndisc_send_ns(dev, target, &mcaddr, saddr);
687 }
688 }
689
690 static int pndisc_is_router(const void *pkey,
691 struct net_device *dev)
692 {
693 struct pneigh_entry *n;
694 int ret = -1;
695
696 read_lock_bh(&nd_tbl.lock);
697 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
698 if (n)
699 ret = !!(n->flags & NTF_ROUTER);
700 read_unlock_bh(&nd_tbl.lock);
701
702 return ret;
703 }
704
705 static void ndisc_recv_ns(struct sk_buff *skb)
706 {
707 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
708 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
709 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
710 u8 *lladdr = NULL;
711 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
712 offsetof(struct nd_msg, opt));
713 struct ndisc_options ndopts;
714 struct net_device *dev = skb->dev;
715 struct inet6_ifaddr *ifp;
716 struct inet6_dev *idev = NULL;
717 struct neighbour *neigh;
718 int dad = ipv6_addr_any(saddr);
719 bool inc;
720 int is_router = -1;
721
722 if (skb->len < sizeof(struct nd_msg)) {
723 ND_PRINTK(2, warn, "NS: packet too short\n");
724 return;
725 }
726
727 if (ipv6_addr_is_multicast(&msg->target)) {
728 ND_PRINTK(2, warn, "NS: multicast target address\n");
729 return;
730 }
731
732 /*
733 * RFC2461 7.1.1:
734 * DAD has to be destined for solicited node multicast address.
735 */
736 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
737 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
738 return;
739 }
740
741 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
742 ND_PRINTK(2, warn, "NS: invalid ND options\n");
743 return;
744 }
745
746 if (ndopts.nd_opts_src_lladdr) {
747 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
748 if (!lladdr) {
749 ND_PRINTK(2, warn,
750 "NS: invalid link-layer address length\n");
751 return;
752 }
753
754 /* RFC2461 7.1.1:
755 * If the IP source address is the unspecified address,
756 * there MUST NOT be source link-layer address option
757 * in the message.
758 */
759 if (dad) {
760 ND_PRINTK(2, warn,
761 "NS: bad DAD packet (link-layer address option)\n");
762 return;
763 }
764 }
765
766 inc = ipv6_addr_is_multicast(daddr);
767
768 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
769 if (ifp) {
770 have_ifp:
771 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
772 if (dad) {
773 /*
774 * We are colliding with another node
775 * who is doing DAD
776 * so fail our DAD process
777 */
778 addrconf_dad_failure(ifp);
779 return;
780 } else {
781 /*
782 * This is not a dad solicitation.
783 * If we are an optimistic node,
784 * we should respond.
785 * Otherwise, we should ignore it.
786 */
787 if (!(ifp->flags & IFA_F_OPTIMISTIC))
788 goto out;
789 }
790 }
791
792 idev = ifp->idev;
793 } else {
794 struct net *net = dev_net(dev);
795
796 /* perhaps an address on the master device */
797 if (netif_is_l3_slave(dev)) {
798 struct net_device *mdev;
799
800 mdev = netdev_master_upper_dev_get_rcu(dev);
801 if (mdev) {
802 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
803 if (ifp)
804 goto have_ifp;
805 }
806 }
807
808 idev = in6_dev_get(dev);
809 if (!idev) {
810 /* XXX: count this drop? */
811 return;
812 }
813
814 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
815 (idev->cnf.forwarding &&
816 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
817 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
818 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
819 skb->pkt_type != PACKET_HOST &&
820 inc &&
821 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
822 /*
823 * for anycast or proxy,
824 * sender should delay its response
825 * by a random time between 0 and
826 * MAX_ANYCAST_DELAY_TIME seconds.
827 * (RFC2461) -- yoshfuji
828 */
829 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
830 if (n)
831 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
832 goto out;
833 }
834 } else
835 goto out;
836 }
837
838 if (is_router < 0)
839 is_router = idev->cnf.forwarding;
840
841 if (dad) {
842 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
843 !!is_router, false, (ifp != NULL), true);
844 goto out;
845 }
846
847 if (inc)
848 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
849 else
850 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
851
852 /*
853 * update / create cache entry
854 * for the source address
855 */
856 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
857 !inc || lladdr || !dev->addr_len);
858 if (neigh)
859 neigh_update(neigh, lladdr, NUD_STALE,
860 NEIGH_UPDATE_F_WEAK_OVERRIDE|
861 NEIGH_UPDATE_F_OVERRIDE);
862 if (neigh || !dev->header_ops) {
863 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
864 true, (ifp != NULL && inc), inc);
865 if (neigh)
866 neigh_release(neigh);
867 }
868
869 out:
870 if (ifp)
871 in6_ifa_put(ifp);
872 else
873 in6_dev_put(idev);
874 }
875
876 static void ndisc_recv_na(struct sk_buff *skb)
877 {
878 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
879 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
880 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
881 u8 *lladdr = NULL;
882 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
883 offsetof(struct nd_msg, opt));
884 struct ndisc_options ndopts;
885 struct net_device *dev = skb->dev;
886 struct inet6_dev *idev = __in6_dev_get(dev);
887 struct inet6_ifaddr *ifp;
888 struct neighbour *neigh;
889
890 if (skb->len < sizeof(struct nd_msg)) {
891 ND_PRINTK(2, warn, "NA: packet too short\n");
892 return;
893 }
894
895 if (ipv6_addr_is_multicast(&msg->target)) {
896 ND_PRINTK(2, warn, "NA: target address is multicast\n");
897 return;
898 }
899
900 if (ipv6_addr_is_multicast(daddr) &&
901 msg->icmph.icmp6_solicited) {
902 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
903 return;
904 }
905
906 /* For some 802.11 wireless deployments (and possibly other networks),
907 * there will be a NA proxy and unsolicitd packets are attacks
908 * and thus should not be accepted.
909 */
910 if (!msg->icmph.icmp6_solicited && idev &&
911 idev->cnf.drop_unsolicited_na)
912 return;
913
914 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
915 ND_PRINTK(2, warn, "NS: invalid ND option\n");
916 return;
917 }
918 if (ndopts.nd_opts_tgt_lladdr) {
919 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
920 if (!lladdr) {
921 ND_PRINTK(2, warn,
922 "NA: invalid link-layer address length\n");
923 return;
924 }
925 }
926 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
927 if (ifp) {
928 if (skb->pkt_type != PACKET_LOOPBACK
929 && (ifp->flags & IFA_F_TENTATIVE)) {
930 addrconf_dad_failure(ifp);
931 return;
932 }
933 /* What should we make now? The advertisement
934 is invalid, but ndisc specs say nothing
935 about it. It could be misconfiguration, or
936 an smart proxy agent tries to help us :-)
937
938 We should not print the error if NA has been
939 received from loopback - it is just our own
940 unsolicited advertisement.
941 */
942 if (skb->pkt_type != PACKET_LOOPBACK)
943 ND_PRINTK(1, warn,
944 "NA: someone advertises our address %pI6 on %s!\n",
945 &ifp->addr, ifp->idev->dev->name);
946 in6_ifa_put(ifp);
947 return;
948 }
949 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
950
951 if (neigh) {
952 u8 old_flags = neigh->flags;
953 struct net *net = dev_net(dev);
954
955 if (neigh->nud_state & NUD_FAILED)
956 goto out;
957
958 /*
959 * Don't update the neighbor cache entry on a proxy NA from
960 * ourselves because either the proxied node is off link or it
961 * has already sent a NA to us.
962 */
963 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
964 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
965 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
966 /* XXX: idev->cnf.proxy_ndp */
967 goto out;
968 }
969
970 neigh_update(neigh, lladdr,
971 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
972 NEIGH_UPDATE_F_WEAK_OVERRIDE|
973 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
974 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
975 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
976
977 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
978 /*
979 * Change: router to host
980 */
981 rt6_clean_tohost(dev_net(dev), saddr);
982 }
983
984 out:
985 neigh_release(neigh);
986 }
987 }
988
989 static void ndisc_recv_rs(struct sk_buff *skb)
990 {
991 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
992 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
993 struct neighbour *neigh;
994 struct inet6_dev *idev;
995 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
996 struct ndisc_options ndopts;
997 u8 *lladdr = NULL;
998
999 if (skb->len < sizeof(*rs_msg))
1000 return;
1001
1002 idev = __in6_dev_get(skb->dev);
1003 if (!idev) {
1004 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1005 return;
1006 }
1007
1008 /* Don't accept RS if we're not in router mode */
1009 if (!idev->cnf.forwarding)
1010 goto out;
1011
1012 /*
1013 * Don't update NCE if src = ::;
1014 * this implies that the source node has no ip address assigned yet.
1015 */
1016 if (ipv6_addr_any(saddr))
1017 goto out;
1018
1019 /* Parse ND options */
1020 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1021 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1022 goto out;
1023 }
1024
1025 if (ndopts.nd_opts_src_lladdr) {
1026 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1027 skb->dev);
1028 if (!lladdr)
1029 goto out;
1030 }
1031
1032 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1033 if (neigh) {
1034 neigh_update(neigh, lladdr, NUD_STALE,
1035 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1036 NEIGH_UPDATE_F_OVERRIDE|
1037 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1038 neigh_release(neigh);
1039 }
1040 out:
1041 return;
1042 }
1043
1044 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1045 {
1046 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1047 struct sk_buff *skb;
1048 struct nlmsghdr *nlh;
1049 struct nduseroptmsg *ndmsg;
1050 struct net *net = dev_net(ra->dev);
1051 int err;
1052 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1053 + (opt->nd_opt_len << 3));
1054 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1055
1056 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1057 if (!skb) {
1058 err = -ENOBUFS;
1059 goto errout;
1060 }
1061
1062 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1063 if (!nlh) {
1064 goto nla_put_failure;
1065 }
1066
1067 ndmsg = nlmsg_data(nlh);
1068 ndmsg->nduseropt_family = AF_INET6;
1069 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1070 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1071 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1072 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1073
1074 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1075
1076 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1077 goto nla_put_failure;
1078 nlmsg_end(skb, nlh);
1079
1080 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1081 return;
1082
1083 nla_put_failure:
1084 nlmsg_free(skb);
1085 err = -EMSGSIZE;
1086 errout:
1087 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1088 }
1089
1090 static void ndisc_router_discovery(struct sk_buff *skb)
1091 {
1092 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1093 struct neighbour *neigh = NULL;
1094 struct inet6_dev *in6_dev;
1095 struct rt6_info *rt = NULL;
1096 int lifetime;
1097 struct ndisc_options ndopts;
1098 int optlen;
1099 unsigned int pref = 0;
1100 __u32 old_if_flags;
1101 bool send_ifinfo_notify = false;
1102
1103 __u8 *opt = (__u8 *)(ra_msg + 1);
1104
1105 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1106 sizeof(struct ra_msg);
1107
1108 ND_PRINTK(2, info,
1109 "RA: %s, dev: %s\n",
1110 __func__, skb->dev->name);
1111 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1112 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1113 return;
1114 }
1115 if (optlen < 0) {
1116 ND_PRINTK(2, warn, "RA: packet too short\n");
1117 return;
1118 }
1119
1120 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1121 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1122 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1123 return;
1124 }
1125 #endif
1126
1127 /*
1128 * set the RA_RECV flag in the interface
1129 */
1130
1131 in6_dev = __in6_dev_get(skb->dev);
1132 if (!in6_dev) {
1133 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1134 skb->dev->name);
1135 return;
1136 }
1137
1138 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1139 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1140 return;
1141 }
1142
1143 if (!ipv6_accept_ra(in6_dev)) {
1144 ND_PRINTK(2, info,
1145 "RA: %s, did not accept ra for dev: %s\n",
1146 __func__, skb->dev->name);
1147 goto skip_linkparms;
1148 }
1149
1150 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1151 /* skip link-specific parameters from interior routers */
1152 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1153 ND_PRINTK(2, info,
1154 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1155 __func__, skb->dev->name);
1156 goto skip_linkparms;
1157 }
1158 #endif
1159
1160 if (in6_dev->if_flags & IF_RS_SENT) {
1161 /*
1162 * flag that an RA was received after an RS was sent
1163 * out on this interface.
1164 */
1165 in6_dev->if_flags |= IF_RA_RCVD;
1166 }
1167
1168 /*
1169 * Remember the managed/otherconf flags from most recently
1170 * received RA message (RFC 2462) -- yoshfuji
1171 */
1172 old_if_flags = in6_dev->if_flags;
1173 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1174 IF_RA_OTHERCONF)) |
1175 (ra_msg->icmph.icmp6_addrconf_managed ?
1176 IF_RA_MANAGED : 0) |
1177 (ra_msg->icmph.icmp6_addrconf_other ?
1178 IF_RA_OTHERCONF : 0);
1179
1180 if (old_if_flags != in6_dev->if_flags)
1181 send_ifinfo_notify = true;
1182
1183 if (!in6_dev->cnf.accept_ra_defrtr) {
1184 ND_PRINTK(2, info,
1185 "RA: %s, defrtr is false for dev: %s\n",
1186 __func__, skb->dev->name);
1187 goto skip_defrtr;
1188 }
1189
1190 /* Do not accept RA with source-addr found on local machine unless
1191 * accept_ra_from_local is set to true.
1192 */
1193 if (!in6_dev->cnf.accept_ra_from_local &&
1194 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1195 in6_dev->dev, 0)) {
1196 ND_PRINTK(2, info,
1197 "RA from local address detected on dev: %s: default router ignored\n",
1198 skb->dev->name);
1199 goto skip_defrtr;
1200 }
1201
1202 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1203
1204 #ifdef CONFIG_IPV6_ROUTER_PREF
1205 pref = ra_msg->icmph.icmp6_router_pref;
1206 /* 10b is handled as if it were 00b (medium) */
1207 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1208 !in6_dev->cnf.accept_ra_rtr_pref)
1209 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1210 #endif
1211
1212 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1213
1214 if (rt) {
1215 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1216 if (!neigh) {
1217 ND_PRINTK(0, err,
1218 "RA: %s got default router without neighbour\n",
1219 __func__);
1220 ip6_rt_put(rt);
1221 return;
1222 }
1223 }
1224 if (rt && lifetime == 0) {
1225 ip6_del_rt(rt);
1226 rt = NULL;
1227 }
1228
1229 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1230 rt, lifetime, skb->dev->name);
1231 if (!rt && lifetime) {
1232 ND_PRINTK(3, info, "RA: adding default router\n");
1233
1234 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1235 if (!rt) {
1236 ND_PRINTK(0, err,
1237 "RA: %s failed to add default route\n",
1238 __func__);
1239 return;
1240 }
1241
1242 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1243 if (!neigh) {
1244 ND_PRINTK(0, err,
1245 "RA: %s got default router without neighbour\n",
1246 __func__);
1247 ip6_rt_put(rt);
1248 return;
1249 }
1250 neigh->flags |= NTF_ROUTER;
1251 } else if (rt) {
1252 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1253 }
1254
1255 if (rt)
1256 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1257 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1258 ra_msg->icmph.icmp6_hop_limit) {
1259 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1260 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1261 if (rt)
1262 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1263 ra_msg->icmph.icmp6_hop_limit);
1264 } else {
1265 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1266 }
1267 }
1268
1269 skip_defrtr:
1270
1271 /*
1272 * Update Reachable Time and Retrans Timer
1273 */
1274
1275 if (in6_dev->nd_parms) {
1276 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1277
1278 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1279 rtime = (rtime*HZ)/1000;
1280 if (rtime < HZ/10)
1281 rtime = HZ/10;
1282 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1283 in6_dev->tstamp = jiffies;
1284 send_ifinfo_notify = true;
1285 }
1286
1287 rtime = ntohl(ra_msg->reachable_time);
1288 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1289 rtime = (rtime*HZ)/1000;
1290
1291 if (rtime < HZ/10)
1292 rtime = HZ/10;
1293
1294 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1295 NEIGH_VAR_SET(in6_dev->nd_parms,
1296 BASE_REACHABLE_TIME, rtime);
1297 NEIGH_VAR_SET(in6_dev->nd_parms,
1298 GC_STALETIME, 3 * rtime);
1299 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1300 in6_dev->tstamp = jiffies;
1301 send_ifinfo_notify = true;
1302 }
1303 }
1304 }
1305
1306 /*
1307 * Send a notify if RA changed managed/otherconf flags or timer settings
1308 */
1309 if (send_ifinfo_notify)
1310 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1311
1312 skip_linkparms:
1313
1314 /*
1315 * Process options.
1316 */
1317
1318 if (!neigh)
1319 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1320 skb->dev, 1);
1321 if (neigh) {
1322 u8 *lladdr = NULL;
1323 if (ndopts.nd_opts_src_lladdr) {
1324 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1325 skb->dev);
1326 if (!lladdr) {
1327 ND_PRINTK(2, warn,
1328 "RA: invalid link-layer address length\n");
1329 goto out;
1330 }
1331 }
1332 neigh_update(neigh, lladdr, NUD_STALE,
1333 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1334 NEIGH_UPDATE_F_OVERRIDE|
1335 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1336 NEIGH_UPDATE_F_ISROUTER);
1337 }
1338
1339 if (!ipv6_accept_ra(in6_dev)) {
1340 ND_PRINTK(2, info,
1341 "RA: %s, accept_ra is false for dev: %s\n",
1342 __func__, skb->dev->name);
1343 goto out;
1344 }
1345
1346 #ifdef CONFIG_IPV6_ROUTE_INFO
1347 if (!in6_dev->cnf.accept_ra_from_local &&
1348 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1349 in6_dev->dev, 0)) {
1350 ND_PRINTK(2, info,
1351 "RA from local address detected on dev: %s: router info ignored.\n",
1352 skb->dev->name);
1353 goto skip_routeinfo;
1354 }
1355
1356 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1357 struct nd_opt_hdr *p;
1358 for (p = ndopts.nd_opts_ri;
1359 p;
1360 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1361 struct route_info *ri = (struct route_info *)p;
1362 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1363 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1364 ri->prefix_len == 0)
1365 continue;
1366 #endif
1367 if (ri->prefix_len == 0 &&
1368 !in6_dev->cnf.accept_ra_defrtr)
1369 continue;
1370 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1371 continue;
1372 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1373 &ipv6_hdr(skb)->saddr);
1374 }
1375 }
1376
1377 skip_routeinfo:
1378 #endif
1379
1380 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1381 /* skip link-specific ndopts from interior routers */
1382 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1383 ND_PRINTK(2, info,
1384 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1385 __func__, skb->dev->name);
1386 goto out;
1387 }
1388 #endif
1389
1390 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1391 struct nd_opt_hdr *p;
1392 for (p = ndopts.nd_opts_pi;
1393 p;
1394 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1395 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1396 (p->nd_opt_len) << 3,
1397 ndopts.nd_opts_src_lladdr != NULL);
1398 }
1399 }
1400
1401 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1402 __be32 n;
1403 u32 mtu;
1404
1405 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1406 mtu = ntohl(n);
1407
1408 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1409 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1410 } else if (in6_dev->cnf.mtu6 != mtu) {
1411 in6_dev->cnf.mtu6 = mtu;
1412
1413 if (rt)
1414 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1415
1416 rt6_mtu_change(skb->dev, mtu);
1417 }
1418 }
1419
1420 if (ndopts.nd_useropts) {
1421 struct nd_opt_hdr *p;
1422 for (p = ndopts.nd_useropts;
1423 p;
1424 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1425 ndisc_ra_useropt(skb, p);
1426 }
1427 }
1428
1429 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1430 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1431 }
1432 out:
1433 ip6_rt_put(rt);
1434 if (neigh)
1435 neigh_release(neigh);
1436 }
1437
1438 static void ndisc_redirect_rcv(struct sk_buff *skb)
1439 {
1440 u8 *hdr;
1441 struct ndisc_options ndopts;
1442 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1443 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1444 offsetof(struct rd_msg, opt));
1445
1446 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1447 switch (skb->ndisc_nodetype) {
1448 case NDISC_NODETYPE_HOST:
1449 case NDISC_NODETYPE_NODEFAULT:
1450 ND_PRINTK(2, warn,
1451 "Redirect: from host or unauthorized router\n");
1452 return;
1453 }
1454 #endif
1455
1456 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1457 ND_PRINTK(2, warn,
1458 "Redirect: source address is not link-local\n");
1459 return;
1460 }
1461
1462 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
1463 return;
1464
1465 if (!ndopts.nd_opts_rh) {
1466 ip6_redirect_no_header(skb, dev_net(skb->dev),
1467 skb->dev->ifindex, 0);
1468 return;
1469 }
1470
1471 hdr = (u8 *)ndopts.nd_opts_rh;
1472 hdr += 8;
1473 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1474 return;
1475
1476 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1477 }
1478
1479 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1480 struct sk_buff *orig_skb,
1481 int rd_len)
1482 {
1483 u8 *opt = skb_put(skb, rd_len);
1484
1485 memset(opt, 0, 8);
1486 *(opt++) = ND_OPT_REDIRECT_HDR;
1487 *(opt++) = (rd_len >> 3);
1488 opt += 6;
1489
1490 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
1491 }
1492
1493 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1494 {
1495 struct net_device *dev = skb->dev;
1496 struct net *net = dev_net(dev);
1497 struct sock *sk = net->ipv6.ndisc_sk;
1498 int optlen = 0;
1499 struct inet_peer *peer;
1500 struct sk_buff *buff;
1501 struct rd_msg *msg;
1502 struct in6_addr saddr_buf;
1503 struct rt6_info *rt;
1504 struct dst_entry *dst;
1505 struct flowi6 fl6;
1506 int rd_len;
1507 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1508 int oif = l3mdev_fib_oif(dev);
1509 bool ret;
1510
1511 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1512 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1513 dev->name);
1514 return;
1515 }
1516
1517 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1518 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1519 ND_PRINTK(2, warn,
1520 "Redirect: target address is not link-local unicast\n");
1521 return;
1522 }
1523
1524 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1525 &saddr_buf, &ipv6_hdr(skb)->saddr, oif);
1526
1527 if (oif != skb->dev->ifindex)
1528 fl6.flowi6_flags |= FLOWI_FLAG_L3MDEV_SRC;
1529
1530 dst = ip6_route_output(net, NULL, &fl6);
1531 if (dst->error) {
1532 dst_release(dst);
1533 return;
1534 }
1535 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1536 if (IS_ERR(dst))
1537 return;
1538
1539 rt = (struct rt6_info *) dst;
1540
1541 if (rt->rt6i_flags & RTF_GATEWAY) {
1542 ND_PRINTK(2, warn,
1543 "Redirect: destination is not a neighbour\n");
1544 goto release;
1545 }
1546 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1547 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1548 if (peer)
1549 inet_putpeer(peer);
1550 if (!ret)
1551 goto release;
1552
1553 if (dev->addr_len) {
1554 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1555 if (!neigh) {
1556 ND_PRINTK(2, warn,
1557 "Redirect: no neigh for target address\n");
1558 goto release;
1559 }
1560
1561 read_lock_bh(&neigh->lock);
1562 if (neigh->nud_state & NUD_VALID) {
1563 memcpy(ha_buf, neigh->ha, dev->addr_len);
1564 read_unlock_bh(&neigh->lock);
1565 ha = ha_buf;
1566 optlen += ndisc_opt_addr_space(dev);
1567 } else
1568 read_unlock_bh(&neigh->lock);
1569
1570 neigh_release(neigh);
1571 }
1572
1573 rd_len = min_t(unsigned int,
1574 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1575 skb->len + 8);
1576 rd_len &= ~0x7;
1577 optlen += rd_len;
1578
1579 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1580 if (!buff)
1581 goto release;
1582
1583 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1584 *msg = (struct rd_msg) {
1585 .icmph = {
1586 .icmp6_type = NDISC_REDIRECT,
1587 },
1588 .target = *target,
1589 .dest = ipv6_hdr(skb)->daddr,
1590 };
1591
1592 /*
1593 * include target_address option
1594 */
1595
1596 if (ha)
1597 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
1598
1599 /*
1600 * build redirect option and copy skb over to the new packet.
1601 */
1602
1603 if (rd_len)
1604 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1605
1606 skb_dst_set(buff, dst);
1607 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1608 return;
1609
1610 release:
1611 dst_release(dst);
1612 }
1613
1614 static void pndisc_redo(struct sk_buff *skb)
1615 {
1616 ndisc_recv_ns(skb);
1617 kfree_skb(skb);
1618 }
1619
1620 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1621 {
1622 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1623
1624 if (!idev)
1625 return true;
1626 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1627 idev->cnf.suppress_frag_ndisc) {
1628 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1629 return true;
1630 }
1631 return false;
1632 }
1633
1634 int ndisc_rcv(struct sk_buff *skb)
1635 {
1636 struct nd_msg *msg;
1637
1638 if (ndisc_suppress_frag_ndisc(skb))
1639 return 0;
1640
1641 if (skb_linearize(skb))
1642 return 0;
1643
1644 msg = (struct nd_msg *)skb_transport_header(skb);
1645
1646 __skb_push(skb, skb->data - skb_transport_header(skb));
1647
1648 if (ipv6_hdr(skb)->hop_limit != 255) {
1649 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1650 ipv6_hdr(skb)->hop_limit);
1651 return 0;
1652 }
1653
1654 if (msg->icmph.icmp6_code != 0) {
1655 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1656 msg->icmph.icmp6_code);
1657 return 0;
1658 }
1659
1660 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1661
1662 switch (msg->icmph.icmp6_type) {
1663 case NDISC_NEIGHBOUR_SOLICITATION:
1664 ndisc_recv_ns(skb);
1665 break;
1666
1667 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1668 ndisc_recv_na(skb);
1669 break;
1670
1671 case NDISC_ROUTER_SOLICITATION:
1672 ndisc_recv_rs(skb);
1673 break;
1674
1675 case NDISC_ROUTER_ADVERTISEMENT:
1676 ndisc_router_discovery(skb);
1677 break;
1678
1679 case NDISC_REDIRECT:
1680 ndisc_redirect_rcv(skb);
1681 break;
1682 }
1683
1684 return 0;
1685 }
1686
1687 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1688 {
1689 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1690 struct netdev_notifier_change_info *change_info;
1691 struct net *net = dev_net(dev);
1692 struct inet6_dev *idev;
1693
1694 switch (event) {
1695 case NETDEV_CHANGEADDR:
1696 neigh_changeaddr(&nd_tbl, dev);
1697 fib6_run_gc(0, net, false);
1698 idev = in6_dev_get(dev);
1699 if (!idev)
1700 break;
1701 if (idev->cnf.ndisc_notify)
1702 ndisc_send_unsol_na(dev);
1703 in6_dev_put(idev);
1704 break;
1705 case NETDEV_CHANGE:
1706 change_info = ptr;
1707 if (change_info->flags_changed & IFF_NOARP)
1708 neigh_changeaddr(&nd_tbl, dev);
1709 break;
1710 case NETDEV_DOWN:
1711 neigh_ifdown(&nd_tbl, dev);
1712 fib6_run_gc(0, net, false);
1713 break;
1714 case NETDEV_NOTIFY_PEERS:
1715 ndisc_send_unsol_na(dev);
1716 break;
1717 default:
1718 break;
1719 }
1720
1721 return NOTIFY_DONE;
1722 }
1723
1724 static struct notifier_block ndisc_netdev_notifier = {
1725 .notifier_call = ndisc_netdev_event,
1726 };
1727
1728 #ifdef CONFIG_SYSCTL
1729 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1730 const char *func, const char *dev_name)
1731 {
1732 static char warncomm[TASK_COMM_LEN];
1733 static int warned;
1734 if (strcmp(warncomm, current->comm) && warned < 5) {
1735 strcpy(warncomm, current->comm);
1736 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1737 warncomm, func,
1738 dev_name, ctl->procname,
1739 dev_name, ctl->procname);
1740 warned++;
1741 }
1742 }
1743
1744 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1745 {
1746 struct net_device *dev = ctl->extra1;
1747 struct inet6_dev *idev;
1748 int ret;
1749
1750 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1751 (strcmp(ctl->procname, "base_reachable_time") == 0))
1752 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1753
1754 if (strcmp(ctl->procname, "retrans_time") == 0)
1755 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1756
1757 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1758 ret = neigh_proc_dointvec_jiffies(ctl, write,
1759 buffer, lenp, ppos);
1760
1761 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1762 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1763 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1764 buffer, lenp, ppos);
1765 else
1766 ret = -1;
1767
1768 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1769 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1770 idev->nd_parms->reachable_time =
1771 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1772 idev->tstamp = jiffies;
1773 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1774 in6_dev_put(idev);
1775 }
1776 return ret;
1777 }
1778
1779
1780 #endif
1781
1782 static int __net_init ndisc_net_init(struct net *net)
1783 {
1784 struct ipv6_pinfo *np;
1785 struct sock *sk;
1786 int err;
1787
1788 err = inet_ctl_sock_create(&sk, PF_INET6,
1789 SOCK_RAW, IPPROTO_ICMPV6, net);
1790 if (err < 0) {
1791 ND_PRINTK(0, err,
1792 "NDISC: Failed to initialize the control socket (err %d)\n",
1793 err);
1794 return err;
1795 }
1796
1797 net->ipv6.ndisc_sk = sk;
1798
1799 np = inet6_sk(sk);
1800 np->hop_limit = 255;
1801 /* Do not loopback ndisc messages */
1802 np->mc_loop = 0;
1803
1804 return 0;
1805 }
1806
1807 static void __net_exit ndisc_net_exit(struct net *net)
1808 {
1809 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1810 }
1811
1812 static struct pernet_operations ndisc_net_ops = {
1813 .init = ndisc_net_init,
1814 .exit = ndisc_net_exit,
1815 };
1816
1817 int __init ndisc_init(void)
1818 {
1819 int err;
1820
1821 err = register_pernet_subsys(&ndisc_net_ops);
1822 if (err)
1823 return err;
1824 /*
1825 * Initialize the neighbour table
1826 */
1827 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1828
1829 #ifdef CONFIG_SYSCTL
1830 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1831 ndisc_ifinfo_sysctl_change);
1832 if (err)
1833 goto out_unregister_pernet;
1834 out:
1835 #endif
1836 return err;
1837
1838 #ifdef CONFIG_SYSCTL
1839 out_unregister_pernet:
1840 unregister_pernet_subsys(&ndisc_net_ops);
1841 goto out;
1842 #endif
1843 }
1844
1845 int __init ndisc_late_init(void)
1846 {
1847 return register_netdevice_notifier(&ndisc_netdev_notifier);
1848 }
1849
1850 void ndisc_late_cleanup(void)
1851 {
1852 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1853 }
1854
1855 void ndisc_cleanup(void)
1856 {
1857 #ifdef CONFIG_SYSCTL
1858 neigh_sysctl_unregister(&nd_tbl.parms);
1859 #endif
1860 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1861 unregister_pernet_subsys(&ndisc_net_ops);
1862 }
Linux kernel - Deliverables
This page took 0.066973 seconds and 5 git commands to generate.