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Merge tag 'iommu-fixes-v3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
[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 int ndisc_constructor(struct neighbour *neigh);
88 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
89 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
90 static int pndisc_constructor(struct pneigh_entry *n);
91 static void pndisc_destructor(struct pneigh_entry *n);
92 static void pndisc_redo(struct sk_buff *skb);
93
94 static const struct neigh_ops ndisc_generic_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_connected_output,
100 };
101
102 static const struct neigh_ops ndisc_hh_ops = {
103 .family = AF_INET6,
104 .solicit = ndisc_solicit,
105 .error_report = ndisc_error_report,
106 .output = neigh_resolve_output,
107 .connected_output = neigh_resolve_output,
108 };
109
110
111 static const struct neigh_ops ndisc_direct_ops = {
112 .family = AF_INET6,
113 .output = neigh_direct_output,
114 .connected_output = neigh_direct_output,
115 };
116
117 struct neigh_table nd_tbl = {
118 .family = AF_INET6,
119 .key_len = sizeof(struct in6_addr),
120 .hash = ndisc_hash,
121 .constructor = ndisc_constructor,
122 .pconstructor = pndisc_constructor,
123 .pdestructor = pndisc_destructor,
124 .proxy_redo = pndisc_redo,
125 .id = "ndisc_cache",
126 .parms = {
127 .tbl = &nd_tbl,
128 .reachable_time = ND_REACHABLE_TIME,
129 .data = {
130 [NEIGH_VAR_MCAST_PROBES] = 3,
131 [NEIGH_VAR_UCAST_PROBES] = 3,
132 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
133 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
134 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
135 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
136 [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024,
137 [NEIGH_VAR_PROXY_QLEN] = 64,
138 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
139 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
140 },
141 },
142 .gc_interval = 30 * HZ,
143 .gc_thresh1 = 128,
144 .gc_thresh2 = 512,
145 .gc_thresh3 = 1024,
146 };
147
148 static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data)
149 {
150 int pad = ndisc_addr_option_pad(skb->dev->type);
151 int data_len = skb->dev->addr_len;
152 int space = ndisc_opt_addr_space(skb->dev);
153 u8 *opt = skb_put(skb, space);
154
155 opt[0] = type;
156 opt[1] = space>>3;
157
158 memset(opt + 2, 0, pad);
159 opt += pad;
160 space -= pad;
161
162 memcpy(opt+2, data, data_len);
163 data_len += 2;
164 opt += data_len;
165 if ((space -= data_len) > 0)
166 memset(opt, 0, space);
167 }
168
169 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
170 struct nd_opt_hdr *end)
171 {
172 int type;
173 if (!cur || !end || cur >= end)
174 return NULL;
175 type = cur->nd_opt_type;
176 do {
177 cur = ((void *)cur) + (cur->nd_opt_len << 3);
178 } while(cur < end && cur->nd_opt_type != type);
179 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
180 }
181
182 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
183 {
184 return opt->nd_opt_type == ND_OPT_RDNSS ||
185 opt->nd_opt_type == ND_OPT_DNSSL;
186 }
187
188 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
189 struct nd_opt_hdr *end)
190 {
191 if (!cur || !end || cur >= end)
192 return NULL;
193 do {
194 cur = ((void *)cur) + (cur->nd_opt_len << 3);
195 } while(cur < end && !ndisc_is_useropt(cur));
196 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
197 }
198
199 struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
200 struct ndisc_options *ndopts)
201 {
202 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
203
204 if (!nd_opt || opt_len < 0 || !ndopts)
205 return NULL;
206 memset(ndopts, 0, sizeof(*ndopts));
207 while (opt_len) {
208 int l;
209 if (opt_len < sizeof(struct nd_opt_hdr))
210 return NULL;
211 l = nd_opt->nd_opt_len << 3;
212 if (opt_len < l || l == 0)
213 return NULL;
214 switch (nd_opt->nd_opt_type) {
215 case ND_OPT_SOURCE_LL_ADDR:
216 case ND_OPT_TARGET_LL_ADDR:
217 case ND_OPT_MTU:
218 case ND_OPT_REDIRECT_HDR:
219 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
220 ND_PRINTK(2, warn,
221 "%s: duplicated ND6 option found: type=%d\n",
222 __func__, nd_opt->nd_opt_type);
223 } else {
224 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
225 }
226 break;
227 case ND_OPT_PREFIX_INFO:
228 ndopts->nd_opts_pi_end = nd_opt;
229 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
230 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
231 break;
232 #ifdef CONFIG_IPV6_ROUTE_INFO
233 case ND_OPT_ROUTE_INFO:
234 ndopts->nd_opts_ri_end = nd_opt;
235 if (!ndopts->nd_opts_ri)
236 ndopts->nd_opts_ri = nd_opt;
237 break;
238 #endif
239 default:
240 if (ndisc_is_useropt(nd_opt)) {
241 ndopts->nd_useropts_end = nd_opt;
242 if (!ndopts->nd_useropts)
243 ndopts->nd_useropts = nd_opt;
244 } else {
245 /*
246 * Unknown options must be silently ignored,
247 * to accommodate future extension to the
248 * protocol.
249 */
250 ND_PRINTK(2, notice,
251 "%s: ignored unsupported option; type=%d, len=%d\n",
252 __func__,
253 nd_opt->nd_opt_type,
254 nd_opt->nd_opt_len);
255 }
256 }
257 opt_len -= l;
258 nd_opt = ((void *)nd_opt) + l;
259 }
260 return ndopts;
261 }
262
263 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
264 {
265 switch (dev->type) {
266 case ARPHRD_ETHER:
267 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
268 case ARPHRD_FDDI:
269 ipv6_eth_mc_map(addr, buf);
270 return 0;
271 case ARPHRD_ARCNET:
272 ipv6_arcnet_mc_map(addr, buf);
273 return 0;
274 case ARPHRD_INFINIBAND:
275 ipv6_ib_mc_map(addr, dev->broadcast, buf);
276 return 0;
277 case ARPHRD_IPGRE:
278 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
279 default:
280 if (dir) {
281 memcpy(buf, dev->broadcast, dev->addr_len);
282 return 0;
283 }
284 }
285 return -EINVAL;
286 }
287
288 EXPORT_SYMBOL(ndisc_mc_map);
289
290 static u32 ndisc_hash(const void *pkey,
291 const struct net_device *dev,
292 __u32 *hash_rnd)
293 {
294 return ndisc_hashfn(pkey, dev, hash_rnd);
295 }
296
297 static int ndisc_constructor(struct neighbour *neigh)
298 {
299 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
300 struct net_device *dev = neigh->dev;
301 struct inet6_dev *in6_dev;
302 struct neigh_parms *parms;
303 bool is_multicast = ipv6_addr_is_multicast(addr);
304
305 in6_dev = in6_dev_get(dev);
306 if (in6_dev == NULL) {
307 return -EINVAL;
308 }
309
310 parms = in6_dev->nd_parms;
311 __neigh_parms_put(neigh->parms);
312 neigh->parms = neigh_parms_clone(parms);
313
314 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
315 if (!dev->header_ops) {
316 neigh->nud_state = NUD_NOARP;
317 neigh->ops = &ndisc_direct_ops;
318 neigh->output = neigh_direct_output;
319 } else {
320 if (is_multicast) {
321 neigh->nud_state = NUD_NOARP;
322 ndisc_mc_map(addr, neigh->ha, dev, 1);
323 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
324 neigh->nud_state = NUD_NOARP;
325 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
326 if (dev->flags&IFF_LOOPBACK)
327 neigh->type = RTN_LOCAL;
328 } else if (dev->flags&IFF_POINTOPOINT) {
329 neigh->nud_state = NUD_NOARP;
330 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
331 }
332 if (dev->header_ops->cache)
333 neigh->ops = &ndisc_hh_ops;
334 else
335 neigh->ops = &ndisc_generic_ops;
336 if (neigh->nud_state&NUD_VALID)
337 neigh->output = neigh->ops->connected_output;
338 else
339 neigh->output = neigh->ops->output;
340 }
341 in6_dev_put(in6_dev);
342 return 0;
343 }
344
345 static int pndisc_constructor(struct pneigh_entry *n)
346 {
347 struct in6_addr *addr = (struct in6_addr*)&n->key;
348 struct in6_addr maddr;
349 struct net_device *dev = n->dev;
350
351 if (dev == NULL || __in6_dev_get(dev) == NULL)
352 return -EINVAL;
353 addrconf_addr_solict_mult(addr, &maddr);
354 ipv6_dev_mc_inc(dev, &maddr);
355 return 0;
356 }
357
358 static void pndisc_destructor(struct pneigh_entry *n)
359 {
360 struct in6_addr *addr = (struct in6_addr*)&n->key;
361 struct in6_addr maddr;
362 struct net_device *dev = n->dev;
363
364 if (dev == NULL || __in6_dev_get(dev) == NULL)
365 return;
366 addrconf_addr_solict_mult(addr, &maddr);
367 ipv6_dev_mc_dec(dev, &maddr);
368 }
369
370 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
371 int len)
372 {
373 int hlen = LL_RESERVED_SPACE(dev);
374 int tlen = dev->needed_tailroom;
375 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
376 struct sk_buff *skb;
377
378 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
379 if (!skb) {
380 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
381 __func__);
382 return NULL;
383 }
384
385 skb->protocol = htons(ETH_P_IPV6);
386 skb->dev = dev;
387
388 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
389 skb_reset_transport_header(skb);
390
391 /* Manually assign socket ownership as we avoid calling
392 * sock_alloc_send_pskb() to bypass wmem buffer limits
393 */
394 skb_set_owner_w(skb, sk);
395
396 return skb;
397 }
398
399 static void ip6_nd_hdr(struct sk_buff *skb,
400 const struct in6_addr *saddr,
401 const struct in6_addr *daddr,
402 int hop_limit, int len)
403 {
404 struct ipv6hdr *hdr;
405
406 skb_push(skb, sizeof(*hdr));
407 skb_reset_network_header(skb);
408 hdr = ipv6_hdr(skb);
409
410 ip6_flow_hdr(hdr, 0, 0);
411
412 hdr->payload_len = htons(len);
413 hdr->nexthdr = IPPROTO_ICMPV6;
414 hdr->hop_limit = hop_limit;
415
416 hdr->saddr = *saddr;
417 hdr->daddr = *daddr;
418 }
419
420 static void ndisc_send_skb(struct sk_buff *skb,
421 const struct in6_addr *daddr,
422 const struct in6_addr *saddr)
423 {
424 struct dst_entry *dst = skb_dst(skb);
425 struct net *net = dev_net(skb->dev);
426 struct sock *sk = net->ipv6.ndisc_sk;
427 struct inet6_dev *idev;
428 int err;
429 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
430 u8 type;
431
432 type = icmp6h->icmp6_type;
433
434 if (!dst) {
435 struct flowi6 fl6;
436
437 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, skb->dev->ifindex);
438 dst = icmp6_dst_alloc(skb->dev, &fl6);
439 if (IS_ERR(dst)) {
440 kfree_skb(skb);
441 return;
442 }
443
444 skb_dst_set(skb, dst);
445 }
446
447 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
448 IPPROTO_ICMPV6,
449 csum_partial(icmp6h,
450 skb->len, 0));
451
452 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
453
454 rcu_read_lock();
455 idev = __in6_dev_get(dst->dev);
456 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
457
458 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
459 dst_output);
460 if (!err) {
461 ICMP6MSGOUT_INC_STATS(net, idev, type);
462 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
463 }
464
465 rcu_read_unlock();
466 }
467
468 void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
469 const struct in6_addr *daddr,
470 const struct in6_addr *solicited_addr,
471 bool router, bool solicited, bool override, bool inc_opt)
472 {
473 struct sk_buff *skb;
474 struct in6_addr tmpaddr;
475 struct inet6_ifaddr *ifp;
476 const struct in6_addr *src_addr;
477 struct nd_msg *msg;
478 int optlen = 0;
479
480 /* for anycast or proxy, solicited_addr != src_addr */
481 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
482 if (ifp) {
483 src_addr = solicited_addr;
484 if (ifp->flags & IFA_F_OPTIMISTIC)
485 override = false;
486 inc_opt |= ifp->idev->cnf.force_tllao;
487 in6_ifa_put(ifp);
488 } else {
489 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
490 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
491 &tmpaddr))
492 return;
493 src_addr = &tmpaddr;
494 }
495
496 if (!dev->addr_len)
497 inc_opt = 0;
498 if (inc_opt)
499 optlen += ndisc_opt_addr_space(dev);
500
501 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
502 if (!skb)
503 return;
504
505 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
506 *msg = (struct nd_msg) {
507 .icmph = {
508 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
509 .icmp6_router = router,
510 .icmp6_solicited = solicited,
511 .icmp6_override = override,
512 },
513 .target = *solicited_addr,
514 };
515
516 if (inc_opt)
517 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
518 dev->dev_addr);
519
520
521 ndisc_send_skb(skb, daddr, src_addr);
522 }
523
524 static void ndisc_send_unsol_na(struct net_device *dev)
525 {
526 struct inet6_dev *idev;
527 struct inet6_ifaddr *ifa;
528
529 idev = in6_dev_get(dev);
530 if (!idev)
531 return;
532
533 read_lock_bh(&idev->lock);
534 list_for_each_entry(ifa, &idev->addr_list, if_list) {
535 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &ifa->addr,
536 /*router=*/ !!idev->cnf.forwarding,
537 /*solicited=*/ false, /*override=*/ true,
538 /*inc_opt=*/ true);
539 }
540 read_unlock_bh(&idev->lock);
541
542 in6_dev_put(idev);
543 }
544
545 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
546 const struct in6_addr *solicit,
547 const struct in6_addr *daddr, const struct in6_addr *saddr)
548 {
549 struct sk_buff *skb;
550 struct in6_addr addr_buf;
551 int inc_opt = dev->addr_len;
552 int optlen = 0;
553 struct nd_msg *msg;
554
555 if (saddr == NULL) {
556 if (ipv6_get_lladdr(dev, &addr_buf,
557 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
558 return;
559 saddr = &addr_buf;
560 }
561
562 if (ipv6_addr_any(saddr))
563 inc_opt = false;
564 if (inc_opt)
565 optlen += ndisc_opt_addr_space(dev);
566
567 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
568 if (!skb)
569 return;
570
571 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
572 *msg = (struct nd_msg) {
573 .icmph = {
574 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
575 },
576 .target = *solicit,
577 };
578
579 if (inc_opt)
580 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
581 dev->dev_addr);
582
583 ndisc_send_skb(skb, daddr, saddr);
584 }
585
586 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
587 const struct in6_addr *daddr)
588 {
589 struct sk_buff *skb;
590 struct rs_msg *msg;
591 int send_sllao = dev->addr_len;
592 int optlen = 0;
593
594 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
595 /*
596 * According to section 2.2 of RFC 4429, we must not
597 * send router solicitations with a sllao from
598 * optimistic addresses, but we may send the solicitation
599 * if we don't include the sllao. So here we check
600 * if our address is optimistic, and if so, we
601 * suppress the inclusion of the sllao.
602 */
603 if (send_sllao) {
604 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
605 dev, 1);
606 if (ifp) {
607 if (ifp->flags & IFA_F_OPTIMISTIC) {
608 send_sllao = 0;
609 }
610 in6_ifa_put(ifp);
611 } else {
612 send_sllao = 0;
613 }
614 }
615 #endif
616 if (send_sllao)
617 optlen += ndisc_opt_addr_space(dev);
618
619 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
620 if (!skb)
621 return;
622
623 msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
624 *msg = (struct rs_msg) {
625 .icmph = {
626 .icmp6_type = NDISC_ROUTER_SOLICITATION,
627 },
628 };
629
630 if (send_sllao)
631 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
632 dev->dev_addr);
633
634 ndisc_send_skb(skb, daddr, saddr);
635 }
636
637
638 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
639 {
640 /*
641 * "The sender MUST return an ICMP
642 * destination unreachable"
643 */
644 dst_link_failure(skb);
645 kfree_skb(skb);
646 }
647
648 /* Called with locked neigh: either read or both */
649
650 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
651 {
652 struct in6_addr *saddr = NULL;
653 struct in6_addr mcaddr;
654 struct net_device *dev = neigh->dev;
655 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
656 int probes = atomic_read(&neigh->probes);
657
658 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
659 saddr = &ipv6_hdr(skb)->saddr;
660
661 if ((probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES)) < 0) {
662 if (!(neigh->nud_state & NUD_VALID)) {
663 ND_PRINTK(1, dbg,
664 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
665 __func__, target);
666 }
667 ndisc_send_ns(dev, neigh, target, target, saddr);
668 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
669 neigh_app_ns(neigh);
670 } else {
671 addrconf_addr_solict_mult(target, &mcaddr);
672 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
673 }
674 }
675
676 static int pndisc_is_router(const void *pkey,
677 struct net_device *dev)
678 {
679 struct pneigh_entry *n;
680 int ret = -1;
681
682 read_lock_bh(&nd_tbl.lock);
683 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
684 if (n)
685 ret = !!(n->flags & NTF_ROUTER);
686 read_unlock_bh(&nd_tbl.lock);
687
688 return ret;
689 }
690
691 static void ndisc_recv_ns(struct sk_buff *skb)
692 {
693 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
694 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
695 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
696 u8 *lladdr = NULL;
697 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
698 offsetof(struct nd_msg, opt));
699 struct ndisc_options ndopts;
700 struct net_device *dev = skb->dev;
701 struct inet6_ifaddr *ifp;
702 struct inet6_dev *idev = NULL;
703 struct neighbour *neigh;
704 int dad = ipv6_addr_any(saddr);
705 bool inc;
706 int is_router = -1;
707
708 if (skb->len < sizeof(struct nd_msg)) {
709 ND_PRINTK(2, warn, "NS: packet too short\n");
710 return;
711 }
712
713 if (ipv6_addr_is_multicast(&msg->target)) {
714 ND_PRINTK(2, warn, "NS: multicast target address\n");
715 return;
716 }
717
718 /*
719 * RFC2461 7.1.1:
720 * DAD has to be destined for solicited node multicast address.
721 */
722 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
723 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
724 return;
725 }
726
727 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
728 ND_PRINTK(2, warn, "NS: invalid ND options\n");
729 return;
730 }
731
732 if (ndopts.nd_opts_src_lladdr) {
733 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
734 if (!lladdr) {
735 ND_PRINTK(2, warn,
736 "NS: invalid link-layer address length\n");
737 return;
738 }
739
740 /* RFC2461 7.1.1:
741 * If the IP source address is the unspecified address,
742 * there MUST NOT be source link-layer address option
743 * in the message.
744 */
745 if (dad) {
746 ND_PRINTK(2, warn,
747 "NS: bad DAD packet (link-layer address option)\n");
748 return;
749 }
750 }
751
752 inc = ipv6_addr_is_multicast(daddr);
753
754 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
755 if (ifp) {
756
757 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
758 if (dad) {
759 /*
760 * We are colliding with another node
761 * who is doing DAD
762 * so fail our DAD process
763 */
764 addrconf_dad_failure(ifp);
765 return;
766 } else {
767 /*
768 * This is not a dad solicitation.
769 * If we are an optimistic node,
770 * we should respond.
771 * Otherwise, we should ignore it.
772 */
773 if (!(ifp->flags & IFA_F_OPTIMISTIC))
774 goto out;
775 }
776 }
777
778 idev = ifp->idev;
779 } else {
780 struct net *net = dev_net(dev);
781
782 idev = in6_dev_get(dev);
783 if (!idev) {
784 /* XXX: count this drop? */
785 return;
786 }
787
788 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
789 (idev->cnf.forwarding &&
790 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
791 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
792 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
793 skb->pkt_type != PACKET_HOST &&
794 inc &&
795 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
796 /*
797 * for anycast or proxy,
798 * sender should delay its response
799 * by a random time between 0 and
800 * MAX_ANYCAST_DELAY_TIME seconds.
801 * (RFC2461) -- yoshfuji
802 */
803 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
804 if (n)
805 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
806 goto out;
807 }
808 } else
809 goto out;
810 }
811
812 if (is_router < 0)
813 is_router = idev->cnf.forwarding;
814
815 if (dad) {
816 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
817 !!is_router, false, (ifp != NULL), true);
818 goto out;
819 }
820
821 if (inc)
822 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
823 else
824 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
825
826 /*
827 * update / create cache entry
828 * for the source address
829 */
830 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
831 !inc || lladdr || !dev->addr_len);
832 if (neigh)
833 neigh_update(neigh, lladdr, NUD_STALE,
834 NEIGH_UPDATE_F_WEAK_OVERRIDE|
835 NEIGH_UPDATE_F_OVERRIDE);
836 if (neigh || !dev->header_ops) {
837 ndisc_send_na(dev, neigh, saddr, &msg->target,
838 !!is_router,
839 true, (ifp != NULL && inc), inc);
840 if (neigh)
841 neigh_release(neigh);
842 }
843
844 out:
845 if (ifp)
846 in6_ifa_put(ifp);
847 else
848 in6_dev_put(idev);
849 }
850
851 static void ndisc_recv_na(struct sk_buff *skb)
852 {
853 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
854 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
855 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
856 u8 *lladdr = NULL;
857 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
858 offsetof(struct nd_msg, opt));
859 struct ndisc_options ndopts;
860 struct net_device *dev = skb->dev;
861 struct inet6_ifaddr *ifp;
862 struct neighbour *neigh;
863
864 if (skb->len < sizeof(struct nd_msg)) {
865 ND_PRINTK(2, warn, "NA: packet too short\n");
866 return;
867 }
868
869 if (ipv6_addr_is_multicast(&msg->target)) {
870 ND_PRINTK(2, warn, "NA: target address is multicast\n");
871 return;
872 }
873
874 if (ipv6_addr_is_multicast(daddr) &&
875 msg->icmph.icmp6_solicited) {
876 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
877 return;
878 }
879
880 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
881 ND_PRINTK(2, warn, "NS: invalid ND option\n");
882 return;
883 }
884 if (ndopts.nd_opts_tgt_lladdr) {
885 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
886 if (!lladdr) {
887 ND_PRINTK(2, warn,
888 "NA: invalid link-layer address length\n");
889 return;
890 }
891 }
892 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
893 if (ifp) {
894 if (skb->pkt_type != PACKET_LOOPBACK
895 && (ifp->flags & IFA_F_TENTATIVE)) {
896 addrconf_dad_failure(ifp);
897 return;
898 }
899 /* What should we make now? The advertisement
900 is invalid, but ndisc specs say nothing
901 about it. It could be misconfiguration, or
902 an smart proxy agent tries to help us :-)
903
904 We should not print the error if NA has been
905 received from loopback - it is just our own
906 unsolicited advertisement.
907 */
908 if (skb->pkt_type != PACKET_LOOPBACK)
909 ND_PRINTK(1, warn,
910 "NA: someone advertises our address %pI6 on %s!\n",
911 &ifp->addr, ifp->idev->dev->name);
912 in6_ifa_put(ifp);
913 return;
914 }
915 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
916
917 if (neigh) {
918 u8 old_flags = neigh->flags;
919 struct net *net = dev_net(dev);
920
921 if (neigh->nud_state & NUD_FAILED)
922 goto out;
923
924 /*
925 * Don't update the neighbor cache entry on a proxy NA from
926 * ourselves because either the proxied node is off link or it
927 * has already sent a NA to us.
928 */
929 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
930 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
931 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
932 /* XXX: idev->cnf.proxy_ndp */
933 goto out;
934 }
935
936 neigh_update(neigh, lladdr,
937 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
938 NEIGH_UPDATE_F_WEAK_OVERRIDE|
939 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
940 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
941 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
942
943 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
944 /*
945 * Change: router to host
946 */
947 rt6_clean_tohost(dev_net(dev), saddr);
948 }
949
950 out:
951 neigh_release(neigh);
952 }
953 }
954
955 static void ndisc_recv_rs(struct sk_buff *skb)
956 {
957 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
958 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
959 struct neighbour *neigh;
960 struct inet6_dev *idev;
961 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
962 struct ndisc_options ndopts;
963 u8 *lladdr = NULL;
964
965 if (skb->len < sizeof(*rs_msg))
966 return;
967
968 idev = __in6_dev_get(skb->dev);
969 if (!idev) {
970 ND_PRINTK(1, err, "RS: can't find in6 device\n");
971 return;
972 }
973
974 /* Don't accept RS if we're not in router mode */
975 if (!idev->cnf.forwarding)
976 goto out;
977
978 /*
979 * Don't update NCE if src = ::;
980 * this implies that the source node has no ip address assigned yet.
981 */
982 if (ipv6_addr_any(saddr))
983 goto out;
984
985 /* Parse ND options */
986 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
987 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
988 goto out;
989 }
990
991 if (ndopts.nd_opts_src_lladdr) {
992 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
993 skb->dev);
994 if (!lladdr)
995 goto out;
996 }
997
998 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
999 if (neigh) {
1000 neigh_update(neigh, lladdr, NUD_STALE,
1001 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1002 NEIGH_UPDATE_F_OVERRIDE|
1003 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1004 neigh_release(neigh);
1005 }
1006 out:
1007 return;
1008 }
1009
1010 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1011 {
1012 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1013 struct sk_buff *skb;
1014 struct nlmsghdr *nlh;
1015 struct nduseroptmsg *ndmsg;
1016 struct net *net = dev_net(ra->dev);
1017 int err;
1018 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1019 + (opt->nd_opt_len << 3));
1020 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1021
1022 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1023 if (skb == NULL) {
1024 err = -ENOBUFS;
1025 goto errout;
1026 }
1027
1028 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1029 if (nlh == NULL) {
1030 goto nla_put_failure;
1031 }
1032
1033 ndmsg = nlmsg_data(nlh);
1034 ndmsg->nduseropt_family = AF_INET6;
1035 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1036 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1037 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1038 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1039
1040 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1041
1042 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1043 &ipv6_hdr(ra)->saddr))
1044 goto nla_put_failure;
1045 nlmsg_end(skb, nlh);
1046
1047 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1048 return;
1049
1050 nla_put_failure:
1051 nlmsg_free(skb);
1052 err = -EMSGSIZE;
1053 errout:
1054 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1055 }
1056
1057 static void ndisc_router_discovery(struct sk_buff *skb)
1058 {
1059 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1060 struct neighbour *neigh = NULL;
1061 struct inet6_dev *in6_dev;
1062 struct rt6_info *rt = NULL;
1063 int lifetime;
1064 struct ndisc_options ndopts;
1065 int optlen;
1066 unsigned int pref = 0;
1067
1068 __u8 * opt = (__u8 *)(ra_msg + 1);
1069
1070 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1071 sizeof(struct ra_msg);
1072
1073 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1074 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1075 return;
1076 }
1077 if (optlen < 0) {
1078 ND_PRINTK(2, warn, "RA: packet too short\n");
1079 return;
1080 }
1081
1082 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1083 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1084 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1085 return;
1086 }
1087 #endif
1088
1089 /*
1090 * set the RA_RECV flag in the interface
1091 */
1092
1093 in6_dev = __in6_dev_get(skb->dev);
1094 if (in6_dev == NULL) {
1095 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1096 skb->dev->name);
1097 return;
1098 }
1099
1100 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1101 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1102 return;
1103 }
1104
1105 if (!ipv6_accept_ra(in6_dev))
1106 goto skip_linkparms;
1107
1108 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1109 /* skip link-specific parameters from interior routers */
1110 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1111 goto skip_linkparms;
1112 #endif
1113
1114 if (in6_dev->if_flags & IF_RS_SENT) {
1115 /*
1116 * flag that an RA was received after an RS was sent
1117 * out on this interface.
1118 */
1119 in6_dev->if_flags |= IF_RA_RCVD;
1120 }
1121
1122 /*
1123 * Remember the managed/otherconf flags from most recently
1124 * received RA message (RFC 2462) -- yoshfuji
1125 */
1126 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1127 IF_RA_OTHERCONF)) |
1128 (ra_msg->icmph.icmp6_addrconf_managed ?
1129 IF_RA_MANAGED : 0) |
1130 (ra_msg->icmph.icmp6_addrconf_other ?
1131 IF_RA_OTHERCONF : 0);
1132
1133 if (!in6_dev->cnf.accept_ra_defrtr)
1134 goto skip_defrtr;
1135
1136 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1137 goto skip_defrtr;
1138
1139 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1140
1141 #ifdef CONFIG_IPV6_ROUTER_PREF
1142 pref = ra_msg->icmph.icmp6_router_pref;
1143 /* 10b is handled as if it were 00b (medium) */
1144 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1145 !in6_dev->cnf.accept_ra_rtr_pref)
1146 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1147 #endif
1148
1149 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1150
1151 if (rt) {
1152 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1153 if (!neigh) {
1154 ND_PRINTK(0, err,
1155 "RA: %s got default router without neighbour\n",
1156 __func__);
1157 ip6_rt_put(rt);
1158 return;
1159 }
1160 }
1161 if (rt && lifetime == 0) {
1162 ip6_del_rt(rt);
1163 rt = NULL;
1164 }
1165
1166 if (rt == NULL && lifetime) {
1167 ND_PRINTK(3, dbg, "RA: adding default router\n");
1168
1169 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1170 if (rt == NULL) {
1171 ND_PRINTK(0, err,
1172 "RA: %s failed to add default route\n",
1173 __func__);
1174 return;
1175 }
1176
1177 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1178 if (neigh == NULL) {
1179 ND_PRINTK(0, err,
1180 "RA: %s got default router without neighbour\n",
1181 __func__);
1182 ip6_rt_put(rt);
1183 return;
1184 }
1185 neigh->flags |= NTF_ROUTER;
1186 } else if (rt) {
1187 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1188 }
1189
1190 if (rt)
1191 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1192 if (ra_msg->icmph.icmp6_hop_limit) {
1193 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1194 if (rt)
1195 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1196 ra_msg->icmph.icmp6_hop_limit);
1197 }
1198
1199 skip_defrtr:
1200
1201 /*
1202 * Update Reachable Time and Retrans Timer
1203 */
1204
1205 if (in6_dev->nd_parms) {
1206 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1207
1208 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1209 rtime = (rtime*HZ)/1000;
1210 if (rtime < HZ/10)
1211 rtime = HZ/10;
1212 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1213 in6_dev->tstamp = jiffies;
1214 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1215 }
1216
1217 rtime = ntohl(ra_msg->reachable_time);
1218 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1219 rtime = (rtime*HZ)/1000;
1220
1221 if (rtime < HZ/10)
1222 rtime = HZ/10;
1223
1224 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1225 NEIGH_VAR_SET(in6_dev->nd_parms,
1226 BASE_REACHABLE_TIME, rtime);
1227 NEIGH_VAR_SET(in6_dev->nd_parms,
1228 GC_STALETIME, 3 * rtime);
1229 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1230 in6_dev->tstamp = jiffies;
1231 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1232 }
1233 }
1234 }
1235
1236 skip_linkparms:
1237
1238 /*
1239 * Process options.
1240 */
1241
1242 if (!neigh)
1243 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1244 skb->dev, 1);
1245 if (neigh) {
1246 u8 *lladdr = NULL;
1247 if (ndopts.nd_opts_src_lladdr) {
1248 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1249 skb->dev);
1250 if (!lladdr) {
1251 ND_PRINTK(2, warn,
1252 "RA: invalid link-layer address length\n");
1253 goto out;
1254 }
1255 }
1256 neigh_update(neigh, lladdr, NUD_STALE,
1257 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1258 NEIGH_UPDATE_F_OVERRIDE|
1259 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1260 NEIGH_UPDATE_F_ISROUTER);
1261 }
1262
1263 if (!ipv6_accept_ra(in6_dev))
1264 goto out;
1265
1266 #ifdef CONFIG_IPV6_ROUTE_INFO
1267 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1268 goto skip_routeinfo;
1269
1270 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1271 struct nd_opt_hdr *p;
1272 for (p = ndopts.nd_opts_ri;
1273 p;
1274 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1275 struct route_info *ri = (struct route_info *)p;
1276 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1277 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1278 ri->prefix_len == 0)
1279 continue;
1280 #endif
1281 if (ri->prefix_len == 0 &&
1282 !in6_dev->cnf.accept_ra_defrtr)
1283 continue;
1284 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1285 continue;
1286 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1287 &ipv6_hdr(skb)->saddr);
1288 }
1289 }
1290
1291 skip_routeinfo:
1292 #endif
1293
1294 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1295 /* skip link-specific ndopts from interior routers */
1296 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1297 goto out;
1298 #endif
1299
1300 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1301 struct nd_opt_hdr *p;
1302 for (p = ndopts.nd_opts_pi;
1303 p;
1304 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1305 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1306 (p->nd_opt_len) << 3,
1307 ndopts.nd_opts_src_lladdr != NULL);
1308 }
1309 }
1310
1311 if (ndopts.nd_opts_mtu) {
1312 __be32 n;
1313 u32 mtu;
1314
1315 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1316 mtu = ntohl(n);
1317
1318 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1319 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1320 } else if (in6_dev->cnf.mtu6 != mtu) {
1321 in6_dev->cnf.mtu6 = mtu;
1322
1323 if (rt)
1324 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1325
1326 rt6_mtu_change(skb->dev, mtu);
1327 }
1328 }
1329
1330 if (ndopts.nd_useropts) {
1331 struct nd_opt_hdr *p;
1332 for (p = ndopts.nd_useropts;
1333 p;
1334 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1335 ndisc_ra_useropt(skb, p);
1336 }
1337 }
1338
1339 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1340 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1341 }
1342 out:
1343 ip6_rt_put(rt);
1344 if (neigh)
1345 neigh_release(neigh);
1346 }
1347
1348 static void ndisc_redirect_rcv(struct sk_buff *skb)
1349 {
1350 u8 *hdr;
1351 struct ndisc_options ndopts;
1352 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1353 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1354 offsetof(struct rd_msg, opt));
1355
1356 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1357 switch (skb->ndisc_nodetype) {
1358 case NDISC_NODETYPE_HOST:
1359 case NDISC_NODETYPE_NODEFAULT:
1360 ND_PRINTK(2, warn,
1361 "Redirect: from host or unauthorized router\n");
1362 return;
1363 }
1364 #endif
1365
1366 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1367 ND_PRINTK(2, warn,
1368 "Redirect: source address is not link-local\n");
1369 return;
1370 }
1371
1372 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
1373 return;
1374
1375 if (!ndopts.nd_opts_rh) {
1376 ip6_redirect_no_header(skb, dev_net(skb->dev),
1377 skb->dev->ifindex, 0);
1378 return;
1379 }
1380
1381 hdr = (u8 *)ndopts.nd_opts_rh;
1382 hdr += 8;
1383 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1384 return;
1385
1386 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1387 }
1388
1389 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1390 struct sk_buff *orig_skb,
1391 int rd_len)
1392 {
1393 u8 *opt = skb_put(skb, rd_len);
1394
1395 memset(opt, 0, 8);
1396 *(opt++) = ND_OPT_REDIRECT_HDR;
1397 *(opt++) = (rd_len >> 3);
1398 opt += 6;
1399
1400 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
1401 }
1402
1403 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1404 {
1405 struct net_device *dev = skb->dev;
1406 struct net *net = dev_net(dev);
1407 struct sock *sk = net->ipv6.ndisc_sk;
1408 int optlen = 0;
1409 struct inet_peer *peer;
1410 struct sk_buff *buff;
1411 struct rd_msg *msg;
1412 struct in6_addr saddr_buf;
1413 struct rt6_info *rt;
1414 struct dst_entry *dst;
1415 struct flowi6 fl6;
1416 int rd_len;
1417 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1418 bool ret;
1419
1420 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1421 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1422 dev->name);
1423 return;
1424 }
1425
1426 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1427 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1428 ND_PRINTK(2, warn,
1429 "Redirect: target address is not link-local unicast\n");
1430 return;
1431 }
1432
1433 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1434 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1435
1436 dst = ip6_route_output(net, NULL, &fl6);
1437 if (dst->error) {
1438 dst_release(dst);
1439 return;
1440 }
1441 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1442 if (IS_ERR(dst))
1443 return;
1444
1445 rt = (struct rt6_info *) dst;
1446
1447 if (rt->rt6i_flags & RTF_GATEWAY) {
1448 ND_PRINTK(2, warn,
1449 "Redirect: destination is not a neighbour\n");
1450 goto release;
1451 }
1452 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
1453 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1454 if (peer)
1455 inet_putpeer(peer);
1456 if (!ret)
1457 goto release;
1458
1459 if (dev->addr_len) {
1460 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1461 if (!neigh) {
1462 ND_PRINTK(2, warn,
1463 "Redirect: no neigh for target address\n");
1464 goto release;
1465 }
1466
1467 read_lock_bh(&neigh->lock);
1468 if (neigh->nud_state & NUD_VALID) {
1469 memcpy(ha_buf, neigh->ha, dev->addr_len);
1470 read_unlock_bh(&neigh->lock);
1471 ha = ha_buf;
1472 optlen += ndisc_opt_addr_space(dev);
1473 } else
1474 read_unlock_bh(&neigh->lock);
1475
1476 neigh_release(neigh);
1477 }
1478
1479 rd_len = min_t(unsigned int,
1480 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1481 skb->len + 8);
1482 rd_len &= ~0x7;
1483 optlen += rd_len;
1484
1485 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1486 if (!buff)
1487 goto release;
1488
1489 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1490 *msg = (struct rd_msg) {
1491 .icmph = {
1492 .icmp6_type = NDISC_REDIRECT,
1493 },
1494 .target = *target,
1495 .dest = ipv6_hdr(skb)->daddr,
1496 };
1497
1498 /*
1499 * include target_address option
1500 */
1501
1502 if (ha)
1503 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
1504
1505 /*
1506 * build redirect option and copy skb over to the new packet.
1507 */
1508
1509 if (rd_len)
1510 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1511
1512 skb_dst_set(buff, dst);
1513 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1514 return;
1515
1516 release:
1517 dst_release(dst);
1518 }
1519
1520 static void pndisc_redo(struct sk_buff *skb)
1521 {
1522 ndisc_recv_ns(skb);
1523 kfree_skb(skb);
1524 }
1525
1526 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1527 {
1528 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1529
1530 if (!idev)
1531 return true;
1532 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1533 idev->cnf.suppress_frag_ndisc) {
1534 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1535 return true;
1536 }
1537 return false;
1538 }
1539
1540 int ndisc_rcv(struct sk_buff *skb)
1541 {
1542 struct nd_msg *msg;
1543
1544 if (ndisc_suppress_frag_ndisc(skb))
1545 return 0;
1546
1547 if (skb_linearize(skb))
1548 return 0;
1549
1550 msg = (struct nd_msg *)skb_transport_header(skb);
1551
1552 __skb_push(skb, skb->data - skb_transport_header(skb));
1553
1554 if (ipv6_hdr(skb)->hop_limit != 255) {
1555 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1556 ipv6_hdr(skb)->hop_limit);
1557 return 0;
1558 }
1559
1560 if (msg->icmph.icmp6_code != 0) {
1561 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1562 msg->icmph.icmp6_code);
1563 return 0;
1564 }
1565
1566 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1567
1568 switch (msg->icmph.icmp6_type) {
1569 case NDISC_NEIGHBOUR_SOLICITATION:
1570 ndisc_recv_ns(skb);
1571 break;
1572
1573 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1574 ndisc_recv_na(skb);
1575 break;
1576
1577 case NDISC_ROUTER_SOLICITATION:
1578 ndisc_recv_rs(skb);
1579 break;
1580
1581 case NDISC_ROUTER_ADVERTISEMENT:
1582 ndisc_router_discovery(skb);
1583 break;
1584
1585 case NDISC_REDIRECT:
1586 ndisc_redirect_rcv(skb);
1587 break;
1588 }
1589
1590 return 0;
1591 }
1592
1593 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1594 {
1595 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1596 struct net *net = dev_net(dev);
1597 struct inet6_dev *idev;
1598
1599 switch (event) {
1600 case NETDEV_CHANGEADDR:
1601 neigh_changeaddr(&nd_tbl, dev);
1602 fib6_run_gc(0, net, false);
1603 idev = in6_dev_get(dev);
1604 if (!idev)
1605 break;
1606 if (idev->cnf.ndisc_notify)
1607 ndisc_send_unsol_na(dev);
1608 in6_dev_put(idev);
1609 break;
1610 case NETDEV_DOWN:
1611 neigh_ifdown(&nd_tbl, dev);
1612 fib6_run_gc(0, net, false);
1613 break;
1614 case NETDEV_NOTIFY_PEERS:
1615 ndisc_send_unsol_na(dev);
1616 break;
1617 default:
1618 break;
1619 }
1620
1621 return NOTIFY_DONE;
1622 }
1623
1624 static struct notifier_block ndisc_netdev_notifier = {
1625 .notifier_call = ndisc_netdev_event,
1626 };
1627
1628 #ifdef CONFIG_SYSCTL
1629 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1630 const char *func, const char *dev_name)
1631 {
1632 static char warncomm[TASK_COMM_LEN];
1633 static int warned;
1634 if (strcmp(warncomm, current->comm) && warned < 5) {
1635 strcpy(warncomm, current->comm);
1636 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1637 warncomm, func,
1638 dev_name, ctl->procname,
1639 dev_name, ctl->procname);
1640 warned++;
1641 }
1642 }
1643
1644 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1645 {
1646 struct net_device *dev = ctl->extra1;
1647 struct inet6_dev *idev;
1648 int ret;
1649
1650 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1651 (strcmp(ctl->procname, "base_reachable_time") == 0))
1652 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1653
1654 if (strcmp(ctl->procname, "retrans_time") == 0)
1655 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1656
1657 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1658 ret = neigh_proc_dointvec_jiffies(ctl, write,
1659 buffer, lenp, ppos);
1660
1661 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1662 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1663 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1664 buffer, lenp, ppos);
1665 else
1666 ret = -1;
1667
1668 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1669 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1670 idev->nd_parms->reachable_time =
1671 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1672 idev->tstamp = jiffies;
1673 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1674 in6_dev_put(idev);
1675 }
1676 return ret;
1677 }
1678
1679
1680 #endif
1681
1682 static int __net_init ndisc_net_init(struct net *net)
1683 {
1684 struct ipv6_pinfo *np;
1685 struct sock *sk;
1686 int err;
1687
1688 err = inet_ctl_sock_create(&sk, PF_INET6,
1689 SOCK_RAW, IPPROTO_ICMPV6, net);
1690 if (err < 0) {
1691 ND_PRINTK(0, err,
1692 "NDISC: Failed to initialize the control socket (err %d)\n",
1693 err);
1694 return err;
1695 }
1696
1697 net->ipv6.ndisc_sk = sk;
1698
1699 np = inet6_sk(sk);
1700 np->hop_limit = 255;
1701 /* Do not loopback ndisc messages */
1702 np->mc_loop = 0;
1703
1704 return 0;
1705 }
1706
1707 static void __net_exit ndisc_net_exit(struct net *net)
1708 {
1709 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1710 }
1711
1712 static struct pernet_operations ndisc_net_ops = {
1713 .init = ndisc_net_init,
1714 .exit = ndisc_net_exit,
1715 };
1716
1717 int __init ndisc_init(void)
1718 {
1719 int err;
1720
1721 err = register_pernet_subsys(&ndisc_net_ops);
1722 if (err)
1723 return err;
1724 /*
1725 * Initialize the neighbour table
1726 */
1727 neigh_table_init(&nd_tbl);
1728
1729 #ifdef CONFIG_SYSCTL
1730 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1731 &ndisc_ifinfo_sysctl_change);
1732 if (err)
1733 goto out_unregister_pernet;
1734 out:
1735 #endif
1736 return err;
1737
1738 #ifdef CONFIG_SYSCTL
1739 out_unregister_pernet:
1740 unregister_pernet_subsys(&ndisc_net_ops);
1741 goto out;
1742 #endif
1743 }
1744
1745 int __init ndisc_late_init(void)
1746 {
1747 return register_netdevice_notifier(&ndisc_netdev_notifier);
1748 }
1749
1750 void ndisc_late_cleanup(void)
1751 {
1752 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1753 }
1754
1755 void ndisc_cleanup(void)
1756 {
1757 #ifdef CONFIG_SYSCTL
1758 neigh_sysctl_unregister(&nd_tbl.parms);
1759 #endif
1760 neigh_table_clear(&nd_tbl);
1761 unregister_pernet_subsys(&ndisc_net_ops);
1762 }
Linux kernel - Deliverables
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