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ebpf: move CONFIG_BPF_SYSCALL-only function declarations
[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 space -= data_len;
166 if (space > 0)
167 memset(opt, 0, space);
168 }
169
170 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
171 struct nd_opt_hdr *end)
172 {
173 int type;
174 if (!cur || !end || cur >= end)
175 return NULL;
176 type = cur->nd_opt_type;
177 do {
178 cur = ((void *)cur) + (cur->nd_opt_len << 3);
179 } while (cur < end && cur->nd_opt_type != type);
180 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
181 }
182
183 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
184 {
185 return opt->nd_opt_type == ND_OPT_RDNSS ||
186 opt->nd_opt_type == ND_OPT_DNSSL;
187 }
188
189 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
190 struct nd_opt_hdr *end)
191 {
192 if (!cur || !end || cur >= end)
193 return NULL;
194 do {
195 cur = ((void *)cur) + (cur->nd_opt_len << 3);
196 } while (cur < end && !ndisc_is_useropt(cur));
197 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
198 }
199
200 struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
201 struct ndisc_options *ndopts)
202 {
203 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
204
205 if (!nd_opt || opt_len < 0 || !ndopts)
206 return NULL;
207 memset(ndopts, 0, sizeof(*ndopts));
208 while (opt_len) {
209 int l;
210 if (opt_len < sizeof(struct nd_opt_hdr))
211 return NULL;
212 l = nd_opt->nd_opt_len << 3;
213 if (opt_len < l || l == 0)
214 return NULL;
215 switch (nd_opt->nd_opt_type) {
216 case ND_OPT_SOURCE_LL_ADDR:
217 case ND_OPT_TARGET_LL_ADDR:
218 case ND_OPT_MTU:
219 case ND_OPT_REDIRECT_HDR:
220 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
221 ND_PRINTK(2, warn,
222 "%s: duplicated ND6 option found: type=%d\n",
223 __func__, nd_opt->nd_opt_type);
224 } else {
225 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
226 }
227 break;
228 case ND_OPT_PREFIX_INFO:
229 ndopts->nd_opts_pi_end = nd_opt;
230 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
231 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
232 break;
233 #ifdef CONFIG_IPV6_ROUTE_INFO
234 case ND_OPT_ROUTE_INFO:
235 ndopts->nd_opts_ri_end = nd_opt;
236 if (!ndopts->nd_opts_ri)
237 ndopts->nd_opts_ri = nd_opt;
238 break;
239 #endif
240 default:
241 if (ndisc_is_useropt(nd_opt)) {
242 ndopts->nd_useropts_end = nd_opt;
243 if (!ndopts->nd_useropts)
244 ndopts->nd_useropts = nd_opt;
245 } else {
246 /*
247 * Unknown options must be silently ignored,
248 * to accommodate future extension to the
249 * protocol.
250 */
251 ND_PRINTK(2, notice,
252 "%s: ignored unsupported option; type=%d, len=%d\n",
253 __func__,
254 nd_opt->nd_opt_type,
255 nd_opt->nd_opt_len);
256 }
257 }
258 opt_len -= l;
259 nd_opt = ((void *)nd_opt) + l;
260 }
261 return ndopts;
262 }
263
264 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
265 {
266 switch (dev->type) {
267 case ARPHRD_ETHER:
268 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
269 case ARPHRD_FDDI:
270 ipv6_eth_mc_map(addr, buf);
271 return 0;
272 case ARPHRD_ARCNET:
273 ipv6_arcnet_mc_map(addr, buf);
274 return 0;
275 case ARPHRD_INFINIBAND:
276 ipv6_ib_mc_map(addr, dev->broadcast, buf);
277 return 0;
278 case ARPHRD_IPGRE:
279 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
280 default:
281 if (dir) {
282 memcpy(buf, dev->broadcast, dev->addr_len);
283 return 0;
284 }
285 }
286 return -EINVAL;
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_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
659 dev, 1,
660 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
661 saddr = &ipv6_hdr(skb)->saddr;
662 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
663 if (probes < 0) {
664 if (!(neigh->nud_state & NUD_VALID)) {
665 ND_PRINTK(1, dbg,
666 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
667 __func__, target);
668 }
669 ndisc_send_ns(dev, neigh, target, target, saddr);
670 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
671 neigh_app_ns(neigh);
672 } else {
673 addrconf_addr_solict_mult(target, &mcaddr);
674 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
675 }
676 }
677
678 static int pndisc_is_router(const void *pkey,
679 struct net_device *dev)
680 {
681 struct pneigh_entry *n;
682 int ret = -1;
683
684 read_lock_bh(&nd_tbl.lock);
685 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
686 if (n)
687 ret = !!(n->flags & NTF_ROUTER);
688 read_unlock_bh(&nd_tbl.lock);
689
690 return ret;
691 }
692
693 static void ndisc_recv_ns(struct sk_buff *skb)
694 {
695 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
696 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
697 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
698 u8 *lladdr = NULL;
699 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
700 offsetof(struct nd_msg, opt));
701 struct ndisc_options ndopts;
702 struct net_device *dev = skb->dev;
703 struct inet6_ifaddr *ifp;
704 struct inet6_dev *idev = NULL;
705 struct neighbour *neigh;
706 int dad = ipv6_addr_any(saddr);
707 bool inc;
708 int is_router = -1;
709
710 if (skb->len < sizeof(struct nd_msg)) {
711 ND_PRINTK(2, warn, "NS: packet too short\n");
712 return;
713 }
714
715 if (ipv6_addr_is_multicast(&msg->target)) {
716 ND_PRINTK(2, warn, "NS: multicast target address\n");
717 return;
718 }
719
720 /*
721 * RFC2461 7.1.1:
722 * DAD has to be destined for solicited node multicast address.
723 */
724 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
725 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
726 return;
727 }
728
729 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
730 ND_PRINTK(2, warn, "NS: invalid ND options\n");
731 return;
732 }
733
734 if (ndopts.nd_opts_src_lladdr) {
735 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
736 if (!lladdr) {
737 ND_PRINTK(2, warn,
738 "NS: invalid link-layer address length\n");
739 return;
740 }
741
742 /* RFC2461 7.1.1:
743 * If the IP source address is the unspecified address,
744 * there MUST NOT be source link-layer address option
745 * in the message.
746 */
747 if (dad) {
748 ND_PRINTK(2, warn,
749 "NS: bad DAD packet (link-layer address option)\n");
750 return;
751 }
752 }
753
754 inc = ipv6_addr_is_multicast(daddr);
755
756 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
757 if (ifp) {
758
759 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
760 if (dad) {
761 /*
762 * We are colliding with another node
763 * who is doing DAD
764 * so fail our DAD process
765 */
766 addrconf_dad_failure(ifp);
767 return;
768 } else {
769 /*
770 * This is not a dad solicitation.
771 * If we are an optimistic node,
772 * we should respond.
773 * Otherwise, we should ignore it.
774 */
775 if (!(ifp->flags & IFA_F_OPTIMISTIC))
776 goto out;
777 }
778 }
779
780 idev = ifp->idev;
781 } else {
782 struct net *net = dev_net(dev);
783
784 idev = in6_dev_get(dev);
785 if (!idev) {
786 /* XXX: count this drop? */
787 return;
788 }
789
790 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
791 (idev->cnf.forwarding &&
792 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
793 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
794 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
795 skb->pkt_type != PACKET_HOST &&
796 inc &&
797 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
798 /*
799 * for anycast or proxy,
800 * sender should delay its response
801 * by a random time between 0 and
802 * MAX_ANYCAST_DELAY_TIME seconds.
803 * (RFC2461) -- yoshfuji
804 */
805 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
806 if (n)
807 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
808 goto out;
809 }
810 } else
811 goto out;
812 }
813
814 if (is_router < 0)
815 is_router = idev->cnf.forwarding;
816
817 if (dad) {
818 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
819 !!is_router, false, (ifp != NULL), true);
820 goto out;
821 }
822
823 if (inc)
824 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
825 else
826 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
827
828 /*
829 * update / create cache entry
830 * for the source address
831 */
832 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
833 !inc || lladdr || !dev->addr_len);
834 if (neigh)
835 neigh_update(neigh, lladdr, NUD_STALE,
836 NEIGH_UPDATE_F_WEAK_OVERRIDE|
837 NEIGH_UPDATE_F_OVERRIDE);
838 if (neigh || !dev->header_ops) {
839 ndisc_send_na(dev, neigh, saddr, &msg->target,
840 !!is_router,
841 true, (ifp != NULL && inc), inc);
842 if (neigh)
843 neigh_release(neigh);
844 }
845
846 out:
847 if (ifp)
848 in6_ifa_put(ifp);
849 else
850 in6_dev_put(idev);
851 }
852
853 static void ndisc_recv_na(struct sk_buff *skb)
854 {
855 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
856 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
857 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
858 u8 *lladdr = NULL;
859 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
860 offsetof(struct nd_msg, opt));
861 struct ndisc_options ndopts;
862 struct net_device *dev = skb->dev;
863 struct inet6_ifaddr *ifp;
864 struct neighbour *neigh;
865
866 if (skb->len < sizeof(struct nd_msg)) {
867 ND_PRINTK(2, warn, "NA: packet too short\n");
868 return;
869 }
870
871 if (ipv6_addr_is_multicast(&msg->target)) {
872 ND_PRINTK(2, warn, "NA: target address is multicast\n");
873 return;
874 }
875
876 if (ipv6_addr_is_multicast(daddr) &&
877 msg->icmph.icmp6_solicited) {
878 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
879 return;
880 }
881
882 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
883 ND_PRINTK(2, warn, "NS: invalid ND option\n");
884 return;
885 }
886 if (ndopts.nd_opts_tgt_lladdr) {
887 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
888 if (!lladdr) {
889 ND_PRINTK(2, warn,
890 "NA: invalid link-layer address length\n");
891 return;
892 }
893 }
894 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
895 if (ifp) {
896 if (skb->pkt_type != PACKET_LOOPBACK
897 && (ifp->flags & IFA_F_TENTATIVE)) {
898 addrconf_dad_failure(ifp);
899 return;
900 }
901 /* What should we make now? The advertisement
902 is invalid, but ndisc specs say nothing
903 about it. It could be misconfiguration, or
904 an smart proxy agent tries to help us :-)
905
906 We should not print the error if NA has been
907 received from loopback - it is just our own
908 unsolicited advertisement.
909 */
910 if (skb->pkt_type != PACKET_LOOPBACK)
911 ND_PRINTK(1, warn,
912 "NA: someone advertises our address %pI6 on %s!\n",
913 &ifp->addr, ifp->idev->dev->name);
914 in6_ifa_put(ifp);
915 return;
916 }
917 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
918
919 if (neigh) {
920 u8 old_flags = neigh->flags;
921 struct net *net = dev_net(dev);
922
923 if (neigh->nud_state & NUD_FAILED)
924 goto out;
925
926 /*
927 * Don't update the neighbor cache entry on a proxy NA from
928 * ourselves because either the proxied node is off link or it
929 * has already sent a NA to us.
930 */
931 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
932 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
933 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
934 /* XXX: idev->cnf.proxy_ndp */
935 goto out;
936 }
937
938 neigh_update(neigh, lladdr,
939 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
940 NEIGH_UPDATE_F_WEAK_OVERRIDE|
941 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
942 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
943 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
944
945 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
946 /*
947 * Change: router to host
948 */
949 rt6_clean_tohost(dev_net(dev), saddr);
950 }
951
952 out:
953 neigh_release(neigh);
954 }
955 }
956
957 static void ndisc_recv_rs(struct sk_buff *skb)
958 {
959 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
960 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
961 struct neighbour *neigh;
962 struct inet6_dev *idev;
963 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
964 struct ndisc_options ndopts;
965 u8 *lladdr = NULL;
966
967 if (skb->len < sizeof(*rs_msg))
968 return;
969
970 idev = __in6_dev_get(skb->dev);
971 if (!idev) {
972 ND_PRINTK(1, err, "RS: can't find in6 device\n");
973 return;
974 }
975
976 /* Don't accept RS if we're not in router mode */
977 if (!idev->cnf.forwarding)
978 goto out;
979
980 /*
981 * Don't update NCE if src = ::;
982 * this implies that the source node has no ip address assigned yet.
983 */
984 if (ipv6_addr_any(saddr))
985 goto out;
986
987 /* Parse ND options */
988 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
989 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
990 goto out;
991 }
992
993 if (ndopts.nd_opts_src_lladdr) {
994 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
995 skb->dev);
996 if (!lladdr)
997 goto out;
998 }
999
1000 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1001 if (neigh) {
1002 neigh_update(neigh, lladdr, NUD_STALE,
1003 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1004 NEIGH_UPDATE_F_OVERRIDE|
1005 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1006 neigh_release(neigh);
1007 }
1008 out:
1009 return;
1010 }
1011
1012 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1013 {
1014 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1015 struct sk_buff *skb;
1016 struct nlmsghdr *nlh;
1017 struct nduseroptmsg *ndmsg;
1018 struct net *net = dev_net(ra->dev);
1019 int err;
1020 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1021 + (opt->nd_opt_len << 3));
1022 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1023
1024 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1025 if (skb == NULL) {
1026 err = -ENOBUFS;
1027 goto errout;
1028 }
1029
1030 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1031 if (nlh == NULL) {
1032 goto nla_put_failure;
1033 }
1034
1035 ndmsg = nlmsg_data(nlh);
1036 ndmsg->nduseropt_family = AF_INET6;
1037 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1038 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1039 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1040 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1041
1042 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1043
1044 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1045 &ipv6_hdr(ra)->saddr))
1046 goto nla_put_failure;
1047 nlmsg_end(skb, nlh);
1048
1049 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1050 return;
1051
1052 nla_put_failure:
1053 nlmsg_free(skb);
1054 err = -EMSGSIZE;
1055 errout:
1056 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1057 }
1058
1059 static void ndisc_router_discovery(struct sk_buff *skb)
1060 {
1061 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1062 struct neighbour *neigh = NULL;
1063 struct inet6_dev *in6_dev;
1064 struct rt6_info *rt = NULL;
1065 int lifetime;
1066 struct ndisc_options ndopts;
1067 int optlen;
1068 unsigned int pref = 0;
1069
1070 __u8 *opt = (__u8 *)(ra_msg + 1);
1071
1072 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1073 sizeof(struct ra_msg);
1074
1075 ND_PRINTK(2, info,
1076 "RA: %s, dev: %s\n",
1077 __func__, skb->dev->name);
1078 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1079 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1080 return;
1081 }
1082 if (optlen < 0) {
1083 ND_PRINTK(2, warn, "RA: packet too short\n");
1084 return;
1085 }
1086
1087 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1088 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1089 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1090 return;
1091 }
1092 #endif
1093
1094 /*
1095 * set the RA_RECV flag in the interface
1096 */
1097
1098 in6_dev = __in6_dev_get(skb->dev);
1099 if (in6_dev == NULL) {
1100 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1101 skb->dev->name);
1102 return;
1103 }
1104
1105 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1106 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1107 return;
1108 }
1109
1110 if (!ipv6_accept_ra(in6_dev)) {
1111 ND_PRINTK(2, info,
1112 "RA: %s, did not accept ra for dev: %s\n",
1113 __func__, skb->dev->name);
1114 goto skip_linkparms;
1115 }
1116
1117 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1118 /* skip link-specific parameters from interior routers */
1119 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1120 ND_PRINTK(2, info,
1121 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1122 __func__, skb->dev->name);
1123 goto skip_linkparms;
1124 }
1125 #endif
1126
1127 if (in6_dev->if_flags & IF_RS_SENT) {
1128 /*
1129 * flag that an RA was received after an RS was sent
1130 * out on this interface.
1131 */
1132 in6_dev->if_flags |= IF_RA_RCVD;
1133 }
1134
1135 /*
1136 * Remember the managed/otherconf flags from most recently
1137 * received RA message (RFC 2462) -- yoshfuji
1138 */
1139 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1140 IF_RA_OTHERCONF)) |
1141 (ra_msg->icmph.icmp6_addrconf_managed ?
1142 IF_RA_MANAGED : 0) |
1143 (ra_msg->icmph.icmp6_addrconf_other ?
1144 IF_RA_OTHERCONF : 0);
1145
1146 if (!in6_dev->cnf.accept_ra_defrtr) {
1147 ND_PRINTK(2, info,
1148 "RA: %s, defrtr is false for dev: %s\n",
1149 __func__, skb->dev->name);
1150 goto skip_defrtr;
1151 }
1152
1153 /* Do not accept RA with source-addr found on local machine unless
1154 * accept_ra_from_local is set to true.
1155 */
1156 if (!in6_dev->cnf.accept_ra_from_local &&
1157 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1158 NULL, 0)) {
1159 ND_PRINTK(2, info,
1160 "RA from local address detected on dev: %s: default router ignored\n",
1161 skb->dev->name);
1162 goto skip_defrtr;
1163 }
1164
1165 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1166
1167 #ifdef CONFIG_IPV6_ROUTER_PREF
1168 pref = ra_msg->icmph.icmp6_router_pref;
1169 /* 10b is handled as if it were 00b (medium) */
1170 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1171 !in6_dev->cnf.accept_ra_rtr_pref)
1172 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1173 #endif
1174
1175 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1176
1177 if (rt) {
1178 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1179 if (!neigh) {
1180 ND_PRINTK(0, err,
1181 "RA: %s got default router without neighbour\n",
1182 __func__);
1183 ip6_rt_put(rt);
1184 return;
1185 }
1186 }
1187 if (rt && lifetime == 0) {
1188 ip6_del_rt(rt);
1189 rt = NULL;
1190 }
1191
1192 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1193 rt, lifetime, skb->dev->name);
1194 if (rt == NULL && lifetime) {
1195 ND_PRINTK(3, info, "RA: adding default router\n");
1196
1197 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1198 if (rt == NULL) {
1199 ND_PRINTK(0, err,
1200 "RA: %s failed to add default route\n",
1201 __func__);
1202 return;
1203 }
1204
1205 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1206 if (neigh == NULL) {
1207 ND_PRINTK(0, err,
1208 "RA: %s got default router without neighbour\n",
1209 __func__);
1210 ip6_rt_put(rt);
1211 return;
1212 }
1213 neigh->flags |= NTF_ROUTER;
1214 } else if (rt) {
1215 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1216 }
1217
1218 if (rt)
1219 rt6_set_expires(rt, jiffies + (HZ * lifetime));
1220 if (ra_msg->icmph.icmp6_hop_limit) {
1221 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1222 if (rt)
1223 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1224 ra_msg->icmph.icmp6_hop_limit);
1225 }
1226
1227 skip_defrtr:
1228
1229 /*
1230 * Update Reachable Time and Retrans Timer
1231 */
1232
1233 if (in6_dev->nd_parms) {
1234 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1235
1236 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1237 rtime = (rtime*HZ)/1000;
1238 if (rtime < HZ/10)
1239 rtime = HZ/10;
1240 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1241 in6_dev->tstamp = jiffies;
1242 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1243 }
1244
1245 rtime = ntohl(ra_msg->reachable_time);
1246 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1247 rtime = (rtime*HZ)/1000;
1248
1249 if (rtime < HZ/10)
1250 rtime = HZ/10;
1251
1252 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1253 NEIGH_VAR_SET(in6_dev->nd_parms,
1254 BASE_REACHABLE_TIME, rtime);
1255 NEIGH_VAR_SET(in6_dev->nd_parms,
1256 GC_STALETIME, 3 * rtime);
1257 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1258 in6_dev->tstamp = jiffies;
1259 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1260 }
1261 }
1262 }
1263
1264 skip_linkparms:
1265
1266 /*
1267 * Process options.
1268 */
1269
1270 if (!neigh)
1271 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1272 skb->dev, 1);
1273 if (neigh) {
1274 u8 *lladdr = NULL;
1275 if (ndopts.nd_opts_src_lladdr) {
1276 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1277 skb->dev);
1278 if (!lladdr) {
1279 ND_PRINTK(2, warn,
1280 "RA: invalid link-layer address length\n");
1281 goto out;
1282 }
1283 }
1284 neigh_update(neigh, lladdr, NUD_STALE,
1285 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1286 NEIGH_UPDATE_F_OVERRIDE|
1287 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1288 NEIGH_UPDATE_F_ISROUTER);
1289 }
1290
1291 if (!ipv6_accept_ra(in6_dev)) {
1292 ND_PRINTK(2, info,
1293 "RA: %s, accept_ra is false for dev: %s\n",
1294 __func__, skb->dev->name);
1295 goto out;
1296 }
1297
1298 #ifdef CONFIG_IPV6_ROUTE_INFO
1299 if (!in6_dev->cnf.accept_ra_from_local &&
1300 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1301 NULL, 0)) {
1302 ND_PRINTK(2, info,
1303 "RA from local address detected on dev: %s: router info ignored.\n",
1304 skb->dev->name);
1305 goto skip_routeinfo;
1306 }
1307
1308 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1309 struct nd_opt_hdr *p;
1310 for (p = ndopts.nd_opts_ri;
1311 p;
1312 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1313 struct route_info *ri = (struct route_info *)p;
1314 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1315 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1316 ri->prefix_len == 0)
1317 continue;
1318 #endif
1319 if (ri->prefix_len == 0 &&
1320 !in6_dev->cnf.accept_ra_defrtr)
1321 continue;
1322 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1323 continue;
1324 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1325 &ipv6_hdr(skb)->saddr);
1326 }
1327 }
1328
1329 skip_routeinfo:
1330 #endif
1331
1332 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1333 /* skip link-specific ndopts from interior routers */
1334 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1335 ND_PRINTK(2, info,
1336 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1337 __func__, skb->dev->name);
1338 goto out;
1339 }
1340 #endif
1341
1342 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1343 struct nd_opt_hdr *p;
1344 for (p = ndopts.nd_opts_pi;
1345 p;
1346 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1347 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1348 (p->nd_opt_len) << 3,
1349 ndopts.nd_opts_src_lladdr != NULL);
1350 }
1351 }
1352
1353 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1354 __be32 n;
1355 u32 mtu;
1356
1357 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1358 mtu = ntohl(n);
1359
1360 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1361 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1362 } else if (in6_dev->cnf.mtu6 != mtu) {
1363 in6_dev->cnf.mtu6 = mtu;
1364
1365 if (rt)
1366 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1367
1368 rt6_mtu_change(skb->dev, mtu);
1369 }
1370 }
1371
1372 if (ndopts.nd_useropts) {
1373 struct nd_opt_hdr *p;
1374 for (p = ndopts.nd_useropts;
1375 p;
1376 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1377 ndisc_ra_useropt(skb, p);
1378 }
1379 }
1380
1381 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1382 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1383 }
1384 out:
1385 ip6_rt_put(rt);
1386 if (neigh)
1387 neigh_release(neigh);
1388 }
1389
1390 static void ndisc_redirect_rcv(struct sk_buff *skb)
1391 {
1392 u8 *hdr;
1393 struct ndisc_options ndopts;
1394 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1395 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1396 offsetof(struct rd_msg, opt));
1397
1398 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1399 switch (skb->ndisc_nodetype) {
1400 case NDISC_NODETYPE_HOST:
1401 case NDISC_NODETYPE_NODEFAULT:
1402 ND_PRINTK(2, warn,
1403 "Redirect: from host or unauthorized router\n");
1404 return;
1405 }
1406 #endif
1407
1408 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1409 ND_PRINTK(2, warn,
1410 "Redirect: source address is not link-local\n");
1411 return;
1412 }
1413
1414 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
1415 return;
1416
1417 if (!ndopts.nd_opts_rh) {
1418 ip6_redirect_no_header(skb, dev_net(skb->dev),
1419 skb->dev->ifindex, 0);
1420 return;
1421 }
1422
1423 hdr = (u8 *)ndopts.nd_opts_rh;
1424 hdr += 8;
1425 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1426 return;
1427
1428 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1429 }
1430
1431 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1432 struct sk_buff *orig_skb,
1433 int rd_len)
1434 {
1435 u8 *opt = skb_put(skb, rd_len);
1436
1437 memset(opt, 0, 8);
1438 *(opt++) = ND_OPT_REDIRECT_HDR;
1439 *(opt++) = (rd_len >> 3);
1440 opt += 6;
1441
1442 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
1443 }
1444
1445 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1446 {
1447 struct net_device *dev = skb->dev;
1448 struct net *net = dev_net(dev);
1449 struct sock *sk = net->ipv6.ndisc_sk;
1450 int optlen = 0;
1451 struct inet_peer *peer;
1452 struct sk_buff *buff;
1453 struct rd_msg *msg;
1454 struct in6_addr saddr_buf;
1455 struct rt6_info *rt;
1456 struct dst_entry *dst;
1457 struct flowi6 fl6;
1458 int rd_len;
1459 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1460 bool ret;
1461
1462 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1463 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1464 dev->name);
1465 return;
1466 }
1467
1468 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1469 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1470 ND_PRINTK(2, warn,
1471 "Redirect: target address is not link-local unicast\n");
1472 return;
1473 }
1474
1475 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1476 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1477
1478 dst = ip6_route_output(net, NULL, &fl6);
1479 if (dst->error) {
1480 dst_release(dst);
1481 return;
1482 }
1483 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1484 if (IS_ERR(dst))
1485 return;
1486
1487 rt = (struct rt6_info *) dst;
1488
1489 if (rt->rt6i_flags & RTF_GATEWAY) {
1490 ND_PRINTK(2, warn,
1491 "Redirect: destination is not a neighbour\n");
1492 goto release;
1493 }
1494 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
1495 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1496 if (peer)
1497 inet_putpeer(peer);
1498 if (!ret)
1499 goto release;
1500
1501 if (dev->addr_len) {
1502 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1503 if (!neigh) {
1504 ND_PRINTK(2, warn,
1505 "Redirect: no neigh for target address\n");
1506 goto release;
1507 }
1508
1509 read_lock_bh(&neigh->lock);
1510 if (neigh->nud_state & NUD_VALID) {
1511 memcpy(ha_buf, neigh->ha, dev->addr_len);
1512 read_unlock_bh(&neigh->lock);
1513 ha = ha_buf;
1514 optlen += ndisc_opt_addr_space(dev);
1515 } else
1516 read_unlock_bh(&neigh->lock);
1517
1518 neigh_release(neigh);
1519 }
1520
1521 rd_len = min_t(unsigned int,
1522 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1523 skb->len + 8);
1524 rd_len &= ~0x7;
1525 optlen += rd_len;
1526
1527 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1528 if (!buff)
1529 goto release;
1530
1531 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1532 *msg = (struct rd_msg) {
1533 .icmph = {
1534 .icmp6_type = NDISC_REDIRECT,
1535 },
1536 .target = *target,
1537 .dest = ipv6_hdr(skb)->daddr,
1538 };
1539
1540 /*
1541 * include target_address option
1542 */
1543
1544 if (ha)
1545 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
1546
1547 /*
1548 * build redirect option and copy skb over to the new packet.
1549 */
1550
1551 if (rd_len)
1552 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1553
1554 skb_dst_set(buff, dst);
1555 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1556 return;
1557
1558 release:
1559 dst_release(dst);
1560 }
1561
1562 static void pndisc_redo(struct sk_buff *skb)
1563 {
1564 ndisc_recv_ns(skb);
1565 kfree_skb(skb);
1566 }
1567
1568 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1569 {
1570 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1571
1572 if (!idev)
1573 return true;
1574 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1575 idev->cnf.suppress_frag_ndisc) {
1576 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1577 return true;
1578 }
1579 return false;
1580 }
1581
1582 int ndisc_rcv(struct sk_buff *skb)
1583 {
1584 struct nd_msg *msg;
1585
1586 if (ndisc_suppress_frag_ndisc(skb))
1587 return 0;
1588
1589 if (skb_linearize(skb))
1590 return 0;
1591
1592 msg = (struct nd_msg *)skb_transport_header(skb);
1593
1594 __skb_push(skb, skb->data - skb_transport_header(skb));
1595
1596 if (ipv6_hdr(skb)->hop_limit != 255) {
1597 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1598 ipv6_hdr(skb)->hop_limit);
1599 return 0;
1600 }
1601
1602 if (msg->icmph.icmp6_code != 0) {
1603 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1604 msg->icmph.icmp6_code);
1605 return 0;
1606 }
1607
1608 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1609
1610 switch (msg->icmph.icmp6_type) {
1611 case NDISC_NEIGHBOUR_SOLICITATION:
1612 ndisc_recv_ns(skb);
1613 break;
1614
1615 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1616 ndisc_recv_na(skb);
1617 break;
1618
1619 case NDISC_ROUTER_SOLICITATION:
1620 ndisc_recv_rs(skb);
1621 break;
1622
1623 case NDISC_ROUTER_ADVERTISEMENT:
1624 ndisc_router_discovery(skb);
1625 break;
1626
1627 case NDISC_REDIRECT:
1628 ndisc_redirect_rcv(skb);
1629 break;
1630 }
1631
1632 return 0;
1633 }
1634
1635 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1636 {
1637 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1638 struct net *net = dev_net(dev);
1639 struct inet6_dev *idev;
1640
1641 switch (event) {
1642 case NETDEV_CHANGEADDR:
1643 neigh_changeaddr(&nd_tbl, dev);
1644 fib6_run_gc(0, net, false);
1645 idev = in6_dev_get(dev);
1646 if (!idev)
1647 break;
1648 if (idev->cnf.ndisc_notify)
1649 ndisc_send_unsol_na(dev);
1650 in6_dev_put(idev);
1651 break;
1652 case NETDEV_DOWN:
1653 neigh_ifdown(&nd_tbl, dev);
1654 fib6_run_gc(0, net, false);
1655 break;
1656 case NETDEV_NOTIFY_PEERS:
1657 ndisc_send_unsol_na(dev);
1658 break;
1659 default:
1660 break;
1661 }
1662
1663 return NOTIFY_DONE;
1664 }
1665
1666 static struct notifier_block ndisc_netdev_notifier = {
1667 .notifier_call = ndisc_netdev_event,
1668 };
1669
1670 #ifdef CONFIG_SYSCTL
1671 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1672 const char *func, const char *dev_name)
1673 {
1674 static char warncomm[TASK_COMM_LEN];
1675 static int warned;
1676 if (strcmp(warncomm, current->comm) && warned < 5) {
1677 strcpy(warncomm, current->comm);
1678 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1679 warncomm, func,
1680 dev_name, ctl->procname,
1681 dev_name, ctl->procname);
1682 warned++;
1683 }
1684 }
1685
1686 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1687 {
1688 struct net_device *dev = ctl->extra1;
1689 struct inet6_dev *idev;
1690 int ret;
1691
1692 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1693 (strcmp(ctl->procname, "base_reachable_time") == 0))
1694 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1695
1696 if (strcmp(ctl->procname, "retrans_time") == 0)
1697 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1698
1699 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1700 ret = neigh_proc_dointvec_jiffies(ctl, write,
1701 buffer, lenp, ppos);
1702
1703 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1704 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1705 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1706 buffer, lenp, ppos);
1707 else
1708 ret = -1;
1709
1710 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1711 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1712 idev->nd_parms->reachable_time =
1713 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1714 idev->tstamp = jiffies;
1715 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1716 in6_dev_put(idev);
1717 }
1718 return ret;
1719 }
1720
1721
1722 #endif
1723
1724 static int __net_init ndisc_net_init(struct net *net)
1725 {
1726 struct ipv6_pinfo *np;
1727 struct sock *sk;
1728 int err;
1729
1730 err = inet_ctl_sock_create(&sk, PF_INET6,
1731 SOCK_RAW, IPPROTO_ICMPV6, net);
1732 if (err < 0) {
1733 ND_PRINTK(0, err,
1734 "NDISC: Failed to initialize the control socket (err %d)\n",
1735 err);
1736 return err;
1737 }
1738
1739 net->ipv6.ndisc_sk = sk;
1740
1741 np = inet6_sk(sk);
1742 np->hop_limit = 255;
1743 /* Do not loopback ndisc messages */
1744 np->mc_loop = 0;
1745
1746 return 0;
1747 }
1748
1749 static void __net_exit ndisc_net_exit(struct net *net)
1750 {
1751 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1752 }
1753
1754 static struct pernet_operations ndisc_net_ops = {
1755 .init = ndisc_net_init,
1756 .exit = ndisc_net_exit,
1757 };
1758
1759 int __init ndisc_init(void)
1760 {
1761 int err;
1762
1763 err = register_pernet_subsys(&ndisc_net_ops);
1764 if (err)
1765 return err;
1766 /*
1767 * Initialize the neighbour table
1768 */
1769 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1770
1771 #ifdef CONFIG_SYSCTL
1772 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1773 ndisc_ifinfo_sysctl_change);
1774 if (err)
1775 goto out_unregister_pernet;
1776 out:
1777 #endif
1778 return err;
1779
1780 #ifdef CONFIG_SYSCTL
1781 out_unregister_pernet:
1782 unregister_pernet_subsys(&ndisc_net_ops);
1783 goto out;
1784 #endif
1785 }
1786
1787 int __init ndisc_late_init(void)
1788 {
1789 return register_netdevice_notifier(&ndisc_netdev_notifier);
1790 }
1791
1792 void ndisc_late_cleanup(void)
1793 {
1794 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1795 }
1796
1797 void ndisc_cleanup(void)
1798 {
1799 #ifdef CONFIG_SYSCTL
1800 neigh_sysctl_unregister(&nd_tbl.parms);
1801 #endif
1802 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1803 unregister_pernet_subsys(&ndisc_net_ops);
1804 }
Linux kernel - Deliverables
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