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