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sysctl net: Remove unused binary sysctl code
[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 * Pierre Ynard : export userland ND options
19 * through netlink (RDNSS support)
20 * Lars Fenneberg : fixed MTU setting on receipt
21 * of an RA.
22 * Janos Farkas : kmalloc failure checks
23 * Alexey Kuznetsov : state machine reworked
24 * and moved to net/core.
25 * Pekka Savola : RFC2461 validation
26 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
27 */
28
29 /* Set to 3 to get tracing... */
30 #define ND_DEBUG 1
31
32 #define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
33 #define ND_NOPRINTK(x...) do { ; } while(0)
34 #define ND_PRINTK0 ND_PRINTK
35 #define ND_PRINTK1 ND_NOPRINTK
36 #define ND_PRINTK2 ND_NOPRINTK
37 #define ND_PRINTK3 ND_NOPRINTK
38 #if ND_DEBUG >= 1
39 #undef ND_PRINTK1
40 #define ND_PRINTK1 ND_PRINTK
41 #endif
42 #if ND_DEBUG >= 2
43 #undef ND_PRINTK2
44 #define ND_PRINTK2 ND_PRINTK
45 #endif
46 #if ND_DEBUG >= 3
47 #undef ND_PRINTK3
48 #define ND_PRINTK3 ND_PRINTK
49 #endif
50
51 #include <linux/module.h>
52 #include <linux/errno.h>
53 #include <linux/types.h>
54 #include <linux/socket.h>
55 #include <linux/sockios.h>
56 #include <linux/sched.h>
57 #include <linux/net.h>
58 #include <linux/in6.h>
59 #include <linux/route.h>
60 #include <linux/init.h>
61 #include <linux/rcupdate.h>
62 #ifdef CONFIG_SYSCTL
63 #include <linux/sysctl.h>
64 #endif
65
66 #include <linux/if_addr.h>
67 #include <linux/if_arp.h>
68 #include <linux/ipv6.h>
69 #include <linux/icmpv6.h>
70 #include <linux/jhash.h>
71
72 #include <net/sock.h>
73 #include <net/snmp.h>
74
75 #include <net/ipv6.h>
76 #include <net/protocol.h>
77 #include <net/ndisc.h>
78 #include <net/ip6_route.h>
79 #include <net/addrconf.h>
80 #include <net/icmp.h>
81
82 #include <net/netlink.h>
83 #include <linux/rtnetlink.h>
84
85 #include <net/flow.h>
86 #include <net/ip6_checksum.h>
87 #include <net/inet_common.h>
88 #include <linux/proc_fs.h>
89
90 #include <linux/netfilter.h>
91 #include <linux/netfilter_ipv6.h>
92
93 static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
94 static int ndisc_constructor(struct neighbour *neigh);
95 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
96 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
97 static int pndisc_constructor(struct pneigh_entry *n);
98 static void pndisc_destructor(struct pneigh_entry *n);
99 static void pndisc_redo(struct sk_buff *skb);
100
101 static const struct neigh_ops ndisc_generic_ops = {
102 .family = AF_INET6,
103 .solicit = ndisc_solicit,
104 .error_report = ndisc_error_report,
105 .output = neigh_resolve_output,
106 .connected_output = neigh_connected_output,
107 .hh_output = dev_queue_xmit,
108 .queue_xmit = dev_queue_xmit,
109 };
110
111 static const struct neigh_ops ndisc_hh_ops = {
112 .family = AF_INET6,
113 .solicit = ndisc_solicit,
114 .error_report = ndisc_error_report,
115 .output = neigh_resolve_output,
116 .connected_output = neigh_resolve_output,
117 .hh_output = dev_queue_xmit,
118 .queue_xmit = dev_queue_xmit,
119 };
120
121
122 static const struct neigh_ops ndisc_direct_ops = {
123 .family = AF_INET6,
124 .output = dev_queue_xmit,
125 .connected_output = dev_queue_xmit,
126 .hh_output = dev_queue_xmit,
127 .queue_xmit = dev_queue_xmit,
128 };
129
130 struct neigh_table nd_tbl = {
131 .family = AF_INET6,
132 .entry_size = sizeof(struct neighbour) + sizeof(struct in6_addr),
133 .key_len = sizeof(struct in6_addr),
134 .hash = ndisc_hash,
135 .constructor = ndisc_constructor,
136 .pconstructor = pndisc_constructor,
137 .pdestructor = pndisc_destructor,
138 .proxy_redo = pndisc_redo,
139 .id = "ndisc_cache",
140 .parms = {
141 .tbl = &nd_tbl,
142 .base_reachable_time = 30 * HZ,
143 .retrans_time = 1 * HZ,
144 .gc_staletime = 60 * HZ,
145 .reachable_time = 30 * HZ,
146 .delay_probe_time = 5 * HZ,
147 .queue_len = 3,
148 .ucast_probes = 3,
149 .mcast_probes = 3,
150 .anycast_delay = 1 * HZ,
151 .proxy_delay = (8 * HZ) / 10,
152 .proxy_qlen = 64,
153 },
154 .gc_interval = 30 * HZ,
155 .gc_thresh1 = 128,
156 .gc_thresh2 = 512,
157 .gc_thresh3 = 1024,
158 };
159
160 /* ND options */
161 struct ndisc_options {
162 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
163 #ifdef CONFIG_IPV6_ROUTE_INFO
164 struct nd_opt_hdr *nd_opts_ri;
165 struct nd_opt_hdr *nd_opts_ri_end;
166 #endif
167 struct nd_opt_hdr *nd_useropts;
168 struct nd_opt_hdr *nd_useropts_end;
169 };
170
171 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
172 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR]
173 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO]
174 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
175 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
176 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
177
178 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
179
180 /*
181 * Return the padding between the option length and the start of the
182 * link addr. Currently only IP-over-InfiniBand needs this, although
183 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
184 * also need a pad of 2.
185 */
186 static int ndisc_addr_option_pad(unsigned short type)
187 {
188 switch (type) {
189 case ARPHRD_INFINIBAND: return 2;
190 default: return 0;
191 }
192 }
193
194 static inline int ndisc_opt_addr_space(struct net_device *dev)
195 {
196 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
197 }
198
199 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
200 unsigned short addr_type)
201 {
202 int space = NDISC_OPT_SPACE(data_len);
203 int pad = ndisc_addr_option_pad(addr_type);
204
205 opt[0] = type;
206 opt[1] = space>>3;
207
208 memset(opt + 2, 0, pad);
209 opt += pad;
210 space -= pad;
211
212 memcpy(opt+2, data, data_len);
213 data_len += 2;
214 opt += data_len;
215 if ((space -= data_len) > 0)
216 memset(opt, 0, space);
217 return opt + space;
218 }
219
220 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
221 struct nd_opt_hdr *end)
222 {
223 int type;
224 if (!cur || !end || cur >= end)
225 return NULL;
226 type = cur->nd_opt_type;
227 do {
228 cur = ((void *)cur) + (cur->nd_opt_len << 3);
229 } while(cur < end && cur->nd_opt_type != type);
230 return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
231 }
232
233 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
234 {
235 return (opt->nd_opt_type == ND_OPT_RDNSS);
236 }
237
238 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
239 struct nd_opt_hdr *end)
240 {
241 if (!cur || !end || cur >= end)
242 return NULL;
243 do {
244 cur = ((void *)cur) + (cur->nd_opt_len << 3);
245 } while(cur < end && !ndisc_is_useropt(cur));
246 return (cur <= end && ndisc_is_useropt(cur) ? cur : NULL);
247 }
248
249 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
250 struct ndisc_options *ndopts)
251 {
252 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
253
254 if (!nd_opt || opt_len < 0 || !ndopts)
255 return NULL;
256 memset(ndopts, 0, sizeof(*ndopts));
257 while (opt_len) {
258 int l;
259 if (opt_len < sizeof(struct nd_opt_hdr))
260 return NULL;
261 l = nd_opt->nd_opt_len << 3;
262 if (opt_len < l || l == 0)
263 return NULL;
264 switch (nd_opt->nd_opt_type) {
265 case ND_OPT_SOURCE_LL_ADDR:
266 case ND_OPT_TARGET_LL_ADDR:
267 case ND_OPT_MTU:
268 case ND_OPT_REDIRECT_HDR:
269 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
270 ND_PRINTK2(KERN_WARNING
271 "%s(): duplicated ND6 option found: type=%d\n",
272 __func__,
273 nd_opt->nd_opt_type);
274 } else {
275 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
276 }
277 break;
278 case ND_OPT_PREFIX_INFO:
279 ndopts->nd_opts_pi_end = nd_opt;
280 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
281 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
282 break;
283 #ifdef CONFIG_IPV6_ROUTE_INFO
284 case ND_OPT_ROUTE_INFO:
285 ndopts->nd_opts_ri_end = nd_opt;
286 if (!ndopts->nd_opts_ri)
287 ndopts->nd_opts_ri = nd_opt;
288 break;
289 #endif
290 default:
291 if (ndisc_is_useropt(nd_opt)) {
292 ndopts->nd_useropts_end = nd_opt;
293 if (!ndopts->nd_useropts)
294 ndopts->nd_useropts = nd_opt;
295 } else {
296 /*
297 * Unknown options must be silently ignored,
298 * to accommodate future extension to the
299 * protocol.
300 */
301 ND_PRINTK2(KERN_NOTICE
302 "%s(): ignored unsupported option; type=%d, len=%d\n",
303 __func__,
304 nd_opt->nd_opt_type, nd_opt->nd_opt_len);
305 }
306 }
307 opt_len -= l;
308 nd_opt = ((void *)nd_opt) + l;
309 }
310 return ndopts;
311 }
312
313 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
314 struct net_device *dev)
315 {
316 u8 *lladdr = (u8 *)(p + 1);
317 int lladdrlen = p->nd_opt_len << 3;
318 int prepad = ndisc_addr_option_pad(dev->type);
319 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
320 return NULL;
321 return (lladdr + prepad);
322 }
323
324 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
325 {
326 switch (dev->type) {
327 case ARPHRD_ETHER:
328 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
329 case ARPHRD_FDDI:
330 ipv6_eth_mc_map(addr, buf);
331 return 0;
332 case ARPHRD_IEEE802_TR:
333 ipv6_tr_mc_map(addr,buf);
334 return 0;
335 case ARPHRD_ARCNET:
336 ipv6_arcnet_mc_map(addr, buf);
337 return 0;
338 case ARPHRD_INFINIBAND:
339 ipv6_ib_mc_map(addr, dev->broadcast, buf);
340 return 0;
341 default:
342 if (dir) {
343 memcpy(buf, dev->broadcast, dev->addr_len);
344 return 0;
345 }
346 }
347 return -EINVAL;
348 }
349
350 EXPORT_SYMBOL(ndisc_mc_map);
351
352 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
353 {
354 const u32 *p32 = pkey;
355 u32 addr_hash, i;
356
357 addr_hash = 0;
358 for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
359 addr_hash ^= *p32++;
360
361 return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
362 }
363
364 static int ndisc_constructor(struct neighbour *neigh)
365 {
366 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
367 struct net_device *dev = neigh->dev;
368 struct inet6_dev *in6_dev;
369 struct neigh_parms *parms;
370 int is_multicast = ipv6_addr_is_multicast(addr);
371
372 rcu_read_lock();
373 in6_dev = in6_dev_get(dev);
374 if (in6_dev == NULL) {
375 rcu_read_unlock();
376 return -EINVAL;
377 }
378
379 parms = in6_dev->nd_parms;
380 __neigh_parms_put(neigh->parms);
381 neigh->parms = neigh_parms_clone(parms);
382 rcu_read_unlock();
383
384 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
385 if (!dev->header_ops) {
386 neigh->nud_state = NUD_NOARP;
387 neigh->ops = &ndisc_direct_ops;
388 neigh->output = neigh->ops->queue_xmit;
389 } else {
390 if (is_multicast) {
391 neigh->nud_state = NUD_NOARP;
392 ndisc_mc_map(addr, neigh->ha, dev, 1);
393 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
394 neigh->nud_state = NUD_NOARP;
395 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
396 if (dev->flags&IFF_LOOPBACK)
397 neigh->type = RTN_LOCAL;
398 } else if (dev->flags&IFF_POINTOPOINT) {
399 neigh->nud_state = NUD_NOARP;
400 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
401 }
402 if (dev->header_ops->cache)
403 neigh->ops = &ndisc_hh_ops;
404 else
405 neigh->ops = &ndisc_generic_ops;
406 if (neigh->nud_state&NUD_VALID)
407 neigh->output = neigh->ops->connected_output;
408 else
409 neigh->output = neigh->ops->output;
410 }
411 in6_dev_put(in6_dev);
412 return 0;
413 }
414
415 static int pndisc_constructor(struct pneigh_entry *n)
416 {
417 struct in6_addr *addr = (struct in6_addr*)&n->key;
418 struct in6_addr maddr;
419 struct net_device *dev = n->dev;
420
421 if (dev == NULL || __in6_dev_get(dev) == NULL)
422 return -EINVAL;
423 addrconf_addr_solict_mult(addr, &maddr);
424 ipv6_dev_mc_inc(dev, &maddr);
425 return 0;
426 }
427
428 static void pndisc_destructor(struct pneigh_entry *n)
429 {
430 struct in6_addr *addr = (struct in6_addr*)&n->key;
431 struct in6_addr maddr;
432 struct net_device *dev = n->dev;
433
434 if (dev == NULL || __in6_dev_get(dev) == NULL)
435 return;
436 addrconf_addr_solict_mult(addr, &maddr);
437 ipv6_dev_mc_dec(dev, &maddr);
438 }
439
440 struct sk_buff *ndisc_build_skb(struct net_device *dev,
441 const struct in6_addr *daddr,
442 const struct in6_addr *saddr,
443 struct icmp6hdr *icmp6h,
444 const struct in6_addr *target,
445 int llinfo)
446 {
447 struct net *net = dev_net(dev);
448 struct sock *sk = net->ipv6.ndisc_sk;
449 struct sk_buff *skb;
450 struct icmp6hdr *hdr;
451 int len;
452 int err;
453 u8 *opt;
454
455 if (!dev->addr_len)
456 llinfo = 0;
457
458 len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
459 if (llinfo)
460 len += ndisc_opt_addr_space(dev);
461
462 skb = sock_alloc_send_skb(sk,
463 (MAX_HEADER + sizeof(struct ipv6hdr) +
464 len + LL_ALLOCATED_SPACE(dev)),
465 1, &err);
466 if (!skb) {
467 ND_PRINTK0(KERN_ERR
468 "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
469 __func__, err);
470 return NULL;
471 }
472
473 skb_reserve(skb, LL_RESERVED_SPACE(dev));
474 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
475
476 skb->transport_header = skb->tail;
477 skb_put(skb, len);
478
479 hdr = (struct icmp6hdr *)skb_transport_header(skb);
480 memcpy(hdr, icmp6h, sizeof(*hdr));
481
482 opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
483 if (target) {
484 ipv6_addr_copy((struct in6_addr *)opt, target);
485 opt += sizeof(*target);
486 }
487
488 if (llinfo)
489 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
490 dev->addr_len, dev->type);
491
492 hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
493 IPPROTO_ICMPV6,
494 csum_partial(hdr,
495 len, 0));
496
497 return skb;
498 }
499
500 EXPORT_SYMBOL(ndisc_build_skb);
501
502 void ndisc_send_skb(struct sk_buff *skb,
503 struct net_device *dev,
504 struct neighbour *neigh,
505 const struct in6_addr *daddr,
506 const struct in6_addr *saddr,
507 struct icmp6hdr *icmp6h)
508 {
509 struct flowi fl;
510 struct dst_entry *dst;
511 struct net *net = dev_net(dev);
512 struct sock *sk = net->ipv6.ndisc_sk;
513 struct inet6_dev *idev;
514 int err;
515 u8 type;
516
517 type = icmp6h->icmp6_type;
518
519 icmpv6_flow_init(sk, &fl, type, saddr, daddr, dev->ifindex);
520
521 dst = icmp6_dst_alloc(dev, neigh, daddr);
522 if (!dst) {
523 kfree_skb(skb);
524 return;
525 }
526
527 err = xfrm_lookup(net, &dst, &fl, NULL, 0);
528 if (err < 0) {
529 kfree_skb(skb);
530 return;
531 }
532
533 skb_dst_set(skb, dst);
534
535 idev = in6_dev_get(dst->dev);
536 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
537
538 err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
539 dst_output);
540 if (!err) {
541 ICMP6MSGOUT_INC_STATS(net, idev, type);
542 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
543 }
544
545 if (likely(idev != NULL))
546 in6_dev_put(idev);
547 }
548
549 EXPORT_SYMBOL(ndisc_send_skb);
550
551 /*
552 * Send a Neighbour Discover packet
553 */
554 static void __ndisc_send(struct net_device *dev,
555 struct neighbour *neigh,
556 const struct in6_addr *daddr,
557 const struct in6_addr *saddr,
558 struct icmp6hdr *icmp6h, const struct in6_addr *target,
559 int llinfo)
560 {
561 struct sk_buff *skb;
562
563 skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
564 if (!skb)
565 return;
566
567 ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
568 }
569
570 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
571 const struct in6_addr *daddr,
572 const struct in6_addr *solicited_addr,
573 int router, int solicited, int override, int inc_opt)
574 {
575 struct in6_addr tmpaddr;
576 struct inet6_ifaddr *ifp;
577 const struct in6_addr *src_addr;
578 struct icmp6hdr icmp6h = {
579 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
580 };
581
582 /* for anycast or proxy, solicited_addr != src_addr */
583 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
584 if (ifp) {
585 src_addr = solicited_addr;
586 if (ifp->flags & IFA_F_OPTIMISTIC)
587 override = 0;
588 in6_ifa_put(ifp);
589 } else {
590 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
591 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
592 &tmpaddr))
593 return;
594 src_addr = &tmpaddr;
595 }
596
597 icmp6h.icmp6_router = router;
598 icmp6h.icmp6_solicited = solicited;
599 icmp6h.icmp6_override = override;
600
601 __ndisc_send(dev, neigh, daddr, src_addr,
602 &icmp6h, solicited_addr,
603 inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
604 }
605
606 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
607 const struct in6_addr *solicit,
608 const struct in6_addr *daddr, const struct in6_addr *saddr)
609 {
610 struct in6_addr addr_buf;
611 struct icmp6hdr icmp6h = {
612 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
613 };
614
615 if (saddr == NULL) {
616 if (ipv6_get_lladdr(dev, &addr_buf,
617 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
618 return;
619 saddr = &addr_buf;
620 }
621
622 __ndisc_send(dev, neigh, daddr, saddr,
623 &icmp6h, solicit,
624 !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
625 }
626
627 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
628 const struct in6_addr *daddr)
629 {
630 struct icmp6hdr icmp6h = {
631 .icmp6_type = NDISC_ROUTER_SOLICITATION,
632 };
633 int send_sllao = dev->addr_len;
634
635 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
636 /*
637 * According to section 2.2 of RFC 4429, we must not
638 * send router solicitations with a sllao from
639 * optimistic addresses, but we may send the solicitation
640 * if we don't include the sllao. So here we check
641 * if our address is optimistic, and if so, we
642 * suppress the inclusion of the sllao.
643 */
644 if (send_sllao) {
645 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
646 dev, 1);
647 if (ifp) {
648 if (ifp->flags & IFA_F_OPTIMISTIC) {
649 send_sllao = 0;
650 }
651 in6_ifa_put(ifp);
652 } else {
653 send_sllao = 0;
654 }
655 }
656 #endif
657 __ndisc_send(dev, NULL, daddr, saddr,
658 &icmp6h, NULL,
659 send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
660 }
661
662
663 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
664 {
665 /*
666 * "The sender MUST return an ICMP
667 * destination unreachable"
668 */
669 dst_link_failure(skb);
670 kfree_skb(skb);
671 }
672
673 /* Called with locked neigh: either read or both */
674
675 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
676 {
677 struct in6_addr *saddr = NULL;
678 struct in6_addr mcaddr;
679 struct net_device *dev = neigh->dev;
680 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
681 int probes = atomic_read(&neigh->probes);
682
683 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
684 saddr = &ipv6_hdr(skb)->saddr;
685
686 if ((probes -= neigh->parms->ucast_probes) < 0) {
687 if (!(neigh->nud_state & NUD_VALID)) {
688 ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
689 __func__, target);
690 }
691 ndisc_send_ns(dev, neigh, target, target, saddr);
692 } else if ((probes -= neigh->parms->app_probes) < 0) {
693 #ifdef CONFIG_ARPD
694 neigh_app_ns(neigh);
695 #endif
696 } else {
697 addrconf_addr_solict_mult(target, &mcaddr);
698 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
699 }
700 }
701
702 static int pndisc_is_router(const void *pkey,
703 struct net_device *dev)
704 {
705 struct pneigh_entry *n;
706 int ret = -1;
707
708 read_lock_bh(&nd_tbl.lock);
709 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
710 if (n)
711 ret = !!(n->flags & NTF_ROUTER);
712 read_unlock_bh(&nd_tbl.lock);
713
714 return ret;
715 }
716
717 static void ndisc_recv_ns(struct sk_buff *skb)
718 {
719 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
720 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
721 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
722 u8 *lladdr = NULL;
723 u32 ndoptlen = skb->tail - (skb->transport_header +
724 offsetof(struct nd_msg, opt));
725 struct ndisc_options ndopts;
726 struct net_device *dev = skb->dev;
727 struct inet6_ifaddr *ifp;
728 struct inet6_dev *idev = NULL;
729 struct neighbour *neigh;
730 int dad = ipv6_addr_any(saddr);
731 int inc;
732 int is_router = -1;
733
734 if (ipv6_addr_is_multicast(&msg->target)) {
735 ND_PRINTK2(KERN_WARNING
736 "ICMPv6 NS: multicast target address");
737 return;
738 }
739
740 /*
741 * RFC2461 7.1.1:
742 * DAD has to be destined for solicited node multicast address.
743 */
744 if (dad &&
745 !(daddr->s6_addr32[0] == htonl(0xff020000) &&
746 daddr->s6_addr32[1] == htonl(0x00000000) &&
747 daddr->s6_addr32[2] == htonl(0x00000001) &&
748 daddr->s6_addr [12] == 0xff )) {
749 ND_PRINTK2(KERN_WARNING
750 "ICMPv6 NS: bad DAD packet (wrong destination)\n");
751 return;
752 }
753
754 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
755 ND_PRINTK2(KERN_WARNING
756 "ICMPv6 NS: invalid ND options\n");
757 return;
758 }
759
760 if (ndopts.nd_opts_src_lladdr) {
761 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
762 if (!lladdr) {
763 ND_PRINTK2(KERN_WARNING
764 "ICMPv6 NS: invalid link-layer address length\n");
765 return;
766 }
767
768 /* RFC2461 7.1.1:
769 * If the IP source address is the unspecified address,
770 * there MUST NOT be source link-layer address option
771 * in the message.
772 */
773 if (dad) {
774 ND_PRINTK2(KERN_WARNING
775 "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
776 return;
777 }
778 }
779
780 inc = ipv6_addr_is_multicast(daddr);
781
782 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
783 if (ifp) {
784
785 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
786 if (dad) {
787 if (dev->type == ARPHRD_IEEE802_TR) {
788 const unsigned char *sadr;
789 sadr = skb_mac_header(skb);
790 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
791 sadr[9] == dev->dev_addr[1] &&
792 sadr[10] == dev->dev_addr[2] &&
793 sadr[11] == dev->dev_addr[3] &&
794 sadr[12] == dev->dev_addr[4] &&
795 sadr[13] == dev->dev_addr[5]) {
796 /* looped-back to us */
797 goto out;
798 }
799 }
800
801 /*
802 * We are colliding with another node
803 * who is doing DAD
804 * so fail our DAD process
805 */
806 addrconf_dad_failure(ifp);
807 return;
808 } else {
809 /*
810 * This is not a dad solicitation.
811 * If we are an optimistic node,
812 * we should respond.
813 * Otherwise, we should ignore it.
814 */
815 if (!(ifp->flags & IFA_F_OPTIMISTIC))
816 goto out;
817 }
818 }
819
820 idev = ifp->idev;
821 } else {
822 struct net *net = dev_net(dev);
823
824 idev = in6_dev_get(dev);
825 if (!idev) {
826 /* XXX: count this drop? */
827 return;
828 }
829
830 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
831 (idev->cnf.forwarding &&
832 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
833 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
834 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
835 skb->pkt_type != PACKET_HOST &&
836 inc != 0 &&
837 idev->nd_parms->proxy_delay != 0) {
838 /*
839 * for anycast or proxy,
840 * sender should delay its response
841 * by a random time between 0 and
842 * MAX_ANYCAST_DELAY_TIME seconds.
843 * (RFC2461) -- yoshfuji
844 */
845 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
846 if (n)
847 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
848 goto out;
849 }
850 } else
851 goto out;
852 }
853
854 if (is_router < 0)
855 is_router = !!idev->cnf.forwarding;
856
857 if (dad) {
858 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
859 is_router, 0, (ifp != NULL), 1);
860 goto out;
861 }
862
863 if (inc)
864 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
865 else
866 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
867
868 /*
869 * update / create cache entry
870 * for the source address
871 */
872 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
873 !inc || lladdr || !dev->addr_len);
874 if (neigh)
875 neigh_update(neigh, lladdr, NUD_STALE,
876 NEIGH_UPDATE_F_WEAK_OVERRIDE|
877 NEIGH_UPDATE_F_OVERRIDE);
878 if (neigh || !dev->header_ops) {
879 ndisc_send_na(dev, neigh, saddr, &msg->target,
880 is_router,
881 1, (ifp != NULL && inc), inc);
882 if (neigh)
883 neigh_release(neigh);
884 }
885
886 out:
887 if (ifp)
888 in6_ifa_put(ifp);
889 else
890 in6_dev_put(idev);
891
892 return;
893 }
894
895 static void ndisc_recv_na(struct sk_buff *skb)
896 {
897 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
898 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
899 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
900 u8 *lladdr = NULL;
901 u32 ndoptlen = skb->tail - (skb->transport_header +
902 offsetof(struct nd_msg, opt));
903 struct ndisc_options ndopts;
904 struct net_device *dev = skb->dev;
905 struct inet6_ifaddr *ifp;
906 struct neighbour *neigh;
907
908 if (skb->len < sizeof(struct nd_msg)) {
909 ND_PRINTK2(KERN_WARNING
910 "ICMPv6 NA: packet too short\n");
911 return;
912 }
913
914 if (ipv6_addr_is_multicast(&msg->target)) {
915 ND_PRINTK2(KERN_WARNING
916 "ICMPv6 NA: target address is multicast.\n");
917 return;
918 }
919
920 if (ipv6_addr_is_multicast(daddr) &&
921 msg->icmph.icmp6_solicited) {
922 ND_PRINTK2(KERN_WARNING
923 "ICMPv6 NA: solicited NA is multicasted.\n");
924 return;
925 }
926
927 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
928 ND_PRINTK2(KERN_WARNING
929 "ICMPv6 NS: invalid ND option\n");
930 return;
931 }
932 if (ndopts.nd_opts_tgt_lladdr) {
933 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
934 if (!lladdr) {
935 ND_PRINTK2(KERN_WARNING
936 "ICMPv6 NA: invalid link-layer address length\n");
937 return;
938 }
939 }
940 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
941 if (ifp) {
942 if (ifp->flags & IFA_F_TENTATIVE) {
943 addrconf_dad_failure(ifp);
944 return;
945 }
946 /* What should we make now? The advertisement
947 is invalid, but ndisc specs say nothing
948 about it. It could be misconfiguration, or
949 an smart proxy agent tries to help us :-)
950
951 We should not print the error if NA has been
952 received from loopback - it is just our own
953 unsolicited advertisement.
954 */
955 if (skb->pkt_type != PACKET_LOOPBACK)
956 ND_PRINTK1(KERN_WARNING
957 "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
958 &ifp->addr, ifp->idev->dev->name);
959 in6_ifa_put(ifp);
960 return;
961 }
962 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
963
964 if (neigh) {
965 u8 old_flags = neigh->flags;
966 struct net *net = dev_net(dev);
967
968 if (neigh->nud_state & NUD_FAILED)
969 goto out;
970
971 /*
972 * Don't update the neighbor cache entry on a proxy NA from
973 * ourselves because either the proxied node is off link or it
974 * has already sent a NA to us.
975 */
976 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
977 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
978 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
979 /* XXX: idev->cnf.prixy_ndp */
980 goto out;
981 }
982
983 neigh_update(neigh, lladdr,
984 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
985 NEIGH_UPDATE_F_WEAK_OVERRIDE|
986 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
987 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
988 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
989
990 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
991 /*
992 * Change: router to host
993 */
994 struct rt6_info *rt;
995 rt = rt6_get_dflt_router(saddr, dev);
996 if (rt)
997 ip6_del_rt(rt);
998 }
999
1000 out:
1001 neigh_release(neigh);
1002 }
1003 }
1004
1005 static void ndisc_recv_rs(struct sk_buff *skb)
1006 {
1007 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1008 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1009 struct neighbour *neigh;
1010 struct inet6_dev *idev;
1011 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1012 struct ndisc_options ndopts;
1013 u8 *lladdr = NULL;
1014
1015 if (skb->len < sizeof(*rs_msg))
1016 return;
1017
1018 idev = in6_dev_get(skb->dev);
1019 if (!idev) {
1020 if (net_ratelimit())
1021 ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1022 return;
1023 }
1024
1025 /* Don't accept RS if we're not in router mode */
1026 if (!idev->cnf.forwarding)
1027 goto out;
1028
1029 /*
1030 * Don't update NCE if src = ::;
1031 * this implies that the source node has no ip address assigned yet.
1032 */
1033 if (ipv6_addr_any(saddr))
1034 goto out;
1035
1036 /* Parse ND options */
1037 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1038 if (net_ratelimit())
1039 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1040 goto out;
1041 }
1042
1043 if (ndopts.nd_opts_src_lladdr) {
1044 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1045 skb->dev);
1046 if (!lladdr)
1047 goto out;
1048 }
1049
1050 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1051 if (neigh) {
1052 neigh_update(neigh, lladdr, NUD_STALE,
1053 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1054 NEIGH_UPDATE_F_OVERRIDE|
1055 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1056 neigh_release(neigh);
1057 }
1058 out:
1059 in6_dev_put(idev);
1060 }
1061
1062 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1063 {
1064 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1065 struct sk_buff *skb;
1066 struct nlmsghdr *nlh;
1067 struct nduseroptmsg *ndmsg;
1068 struct net *net = dev_net(ra->dev);
1069 int err;
1070 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1071 + (opt->nd_opt_len << 3));
1072 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1073
1074 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1075 if (skb == NULL) {
1076 err = -ENOBUFS;
1077 goto errout;
1078 }
1079
1080 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1081 if (nlh == NULL) {
1082 goto nla_put_failure;
1083 }
1084
1085 ndmsg = nlmsg_data(nlh);
1086 ndmsg->nduseropt_family = AF_INET6;
1087 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1088 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1089 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1090 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1091
1092 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1093
1094 NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1095 &ipv6_hdr(ra)->saddr);
1096 nlmsg_end(skb, nlh);
1097
1098 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1099 return;
1100
1101 nla_put_failure:
1102 nlmsg_free(skb);
1103 err = -EMSGSIZE;
1104 errout:
1105 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1106 }
1107
1108 static void ndisc_router_discovery(struct sk_buff *skb)
1109 {
1110 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1111 struct neighbour *neigh = NULL;
1112 struct inet6_dev *in6_dev;
1113 struct rt6_info *rt = NULL;
1114 int lifetime;
1115 struct ndisc_options ndopts;
1116 int optlen;
1117 unsigned int pref = 0;
1118
1119 __u8 * opt = (__u8 *)(ra_msg + 1);
1120
1121 optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1122
1123 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1124 ND_PRINTK2(KERN_WARNING
1125 "ICMPv6 RA: source address is not link-local.\n");
1126 return;
1127 }
1128 if (optlen < 0) {
1129 ND_PRINTK2(KERN_WARNING
1130 "ICMPv6 RA: packet too short\n");
1131 return;
1132 }
1133
1134 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1135 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1136 ND_PRINTK2(KERN_WARNING
1137 "ICMPv6 RA: from host or unauthorized router\n");
1138 return;
1139 }
1140 #endif
1141
1142 /*
1143 * set the RA_RECV flag in the interface
1144 */
1145
1146 in6_dev = in6_dev_get(skb->dev);
1147 if (in6_dev == NULL) {
1148 ND_PRINTK0(KERN_ERR
1149 "ICMPv6 RA: can't find inet6 device for %s.\n",
1150 skb->dev->name);
1151 return;
1152 }
1153
1154 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1155 in6_dev_put(in6_dev);
1156 ND_PRINTK2(KERN_WARNING
1157 "ICMP6 RA: invalid ND options\n");
1158 return;
1159 }
1160
1161 /* skip route and link configuration on routers */
1162 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra)
1163 goto skip_linkparms;
1164
1165 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1166 /* skip link-specific parameters from interior routers */
1167 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1168 goto skip_linkparms;
1169 #endif
1170
1171 if (in6_dev->if_flags & IF_RS_SENT) {
1172 /*
1173 * flag that an RA was received after an RS was sent
1174 * out on this interface.
1175 */
1176 in6_dev->if_flags |= IF_RA_RCVD;
1177 }
1178
1179 /*
1180 * Remember the managed/otherconf flags from most recently
1181 * received RA message (RFC 2462) -- yoshfuji
1182 */
1183 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1184 IF_RA_OTHERCONF)) |
1185 (ra_msg->icmph.icmp6_addrconf_managed ?
1186 IF_RA_MANAGED : 0) |
1187 (ra_msg->icmph.icmp6_addrconf_other ?
1188 IF_RA_OTHERCONF : 0);
1189
1190 if (!in6_dev->cnf.accept_ra_defrtr)
1191 goto skip_defrtr;
1192
1193 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1194
1195 #ifdef CONFIG_IPV6_ROUTER_PREF
1196 pref = ra_msg->icmph.icmp6_router_pref;
1197 /* 10b is handled as if it were 00b (medium) */
1198 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1199 !in6_dev->cnf.accept_ra_rtr_pref)
1200 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1201 #endif
1202
1203 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1204
1205 if (rt)
1206 neigh = rt->rt6i_nexthop;
1207
1208 if (rt && lifetime == 0) {
1209 neigh_clone(neigh);
1210 ip6_del_rt(rt);
1211 rt = NULL;
1212 }
1213
1214 if (rt == NULL && lifetime) {
1215 ND_PRINTK3(KERN_DEBUG
1216 "ICMPv6 RA: adding default router.\n");
1217
1218 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1219 if (rt == NULL) {
1220 ND_PRINTK0(KERN_ERR
1221 "ICMPv6 RA: %s() failed to add default route.\n",
1222 __func__);
1223 in6_dev_put(in6_dev);
1224 return;
1225 }
1226
1227 neigh = rt->rt6i_nexthop;
1228 if (neigh == NULL) {
1229 ND_PRINTK0(KERN_ERR
1230 "ICMPv6 RA: %s() got default router without neighbour.\n",
1231 __func__);
1232 dst_release(&rt->u.dst);
1233 in6_dev_put(in6_dev);
1234 return;
1235 }
1236 neigh->flags |= NTF_ROUTER;
1237 } else if (rt) {
1238 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1239 }
1240
1241 if (rt)
1242 rt->rt6i_expires = jiffies + (HZ * lifetime);
1243
1244 if (ra_msg->icmph.icmp6_hop_limit) {
1245 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1246 if (rt)
1247 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1248 }
1249
1250 skip_defrtr:
1251
1252 /*
1253 * Update Reachable Time and Retrans Timer
1254 */
1255
1256 if (in6_dev->nd_parms) {
1257 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1258
1259 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1260 rtime = (rtime*HZ)/1000;
1261 if (rtime < HZ/10)
1262 rtime = HZ/10;
1263 in6_dev->nd_parms->retrans_time = rtime;
1264 in6_dev->tstamp = jiffies;
1265 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1266 }
1267
1268 rtime = ntohl(ra_msg->reachable_time);
1269 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1270 rtime = (rtime*HZ)/1000;
1271
1272 if (rtime < HZ/10)
1273 rtime = HZ/10;
1274
1275 if (rtime != in6_dev->nd_parms->base_reachable_time) {
1276 in6_dev->nd_parms->base_reachable_time = rtime;
1277 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1278 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1279 in6_dev->tstamp = jiffies;
1280 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1281 }
1282 }
1283 }
1284
1285 skip_linkparms:
1286
1287 /*
1288 * Process options.
1289 */
1290
1291 if (!neigh)
1292 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1293 skb->dev, 1);
1294 if (neigh) {
1295 u8 *lladdr = NULL;
1296 if (ndopts.nd_opts_src_lladdr) {
1297 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1298 skb->dev);
1299 if (!lladdr) {
1300 ND_PRINTK2(KERN_WARNING
1301 "ICMPv6 RA: invalid link-layer address length\n");
1302 goto out;
1303 }
1304 }
1305 neigh_update(neigh, lladdr, NUD_STALE,
1306 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1307 NEIGH_UPDATE_F_OVERRIDE|
1308 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1309 NEIGH_UPDATE_F_ISROUTER);
1310 }
1311
1312 /* skip route and link configuration on routers */
1313 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra)
1314 goto out;
1315
1316 #ifdef CONFIG_IPV6_ROUTE_INFO
1317 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1318 struct nd_opt_hdr *p;
1319 for (p = ndopts.nd_opts_ri;
1320 p;
1321 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1322 struct route_info *ri = (struct route_info *)p;
1323 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1324 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1325 ri->prefix_len == 0)
1326 continue;
1327 #endif
1328 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1329 continue;
1330 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1331 &ipv6_hdr(skb)->saddr);
1332 }
1333 }
1334 #endif
1335
1336 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1337 /* skip link-specific ndopts from interior routers */
1338 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1339 goto out;
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, (p->nd_opt_len) << 3);
1348 }
1349 }
1350
1351 if (ndopts.nd_opts_mtu) {
1352 __be32 n;
1353 u32 mtu;
1354
1355 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1356 mtu = ntohl(n);
1357
1358 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1359 ND_PRINTK2(KERN_WARNING
1360 "ICMPv6 RA: invalid mtu: %d\n",
1361 mtu);
1362 } else if (in6_dev->cnf.mtu6 != mtu) {
1363 in6_dev->cnf.mtu6 = mtu;
1364
1365 if (rt)
1366 rt->u.dst.metrics[RTAX_MTU-1] = 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_PRINTK2(KERN_WARNING
1383 "ICMPv6 RA: invalid RA options");
1384 }
1385 out:
1386 if (rt)
1387 dst_release(&rt->u.dst);
1388 else if (neigh)
1389 neigh_release(neigh);
1390 in6_dev_put(in6_dev);
1391 }
1392
1393 static void ndisc_redirect_rcv(struct sk_buff *skb)
1394 {
1395 struct inet6_dev *in6_dev;
1396 struct icmp6hdr *icmph;
1397 struct in6_addr *dest;
1398 struct in6_addr *target; /* new first hop to destination */
1399 struct neighbour *neigh;
1400 int on_link = 0;
1401 struct ndisc_options ndopts;
1402 int optlen;
1403 u8 *lladdr = NULL;
1404
1405 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1406 switch (skb->ndisc_nodetype) {
1407 case NDISC_NODETYPE_HOST:
1408 case NDISC_NODETYPE_NODEFAULT:
1409 ND_PRINTK2(KERN_WARNING
1410 "ICMPv6 Redirect: from host or unauthorized router\n");
1411 return;
1412 }
1413 #endif
1414
1415 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1416 ND_PRINTK2(KERN_WARNING
1417 "ICMPv6 Redirect: source address is not link-local.\n");
1418 return;
1419 }
1420
1421 optlen = skb->tail - skb->transport_header;
1422 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1423
1424 if (optlen < 0) {
1425 ND_PRINTK2(KERN_WARNING
1426 "ICMPv6 Redirect: packet too short\n");
1427 return;
1428 }
1429
1430 icmph = icmp6_hdr(skb);
1431 target = (struct in6_addr *) (icmph + 1);
1432 dest = target + 1;
1433
1434 if (ipv6_addr_is_multicast(dest)) {
1435 ND_PRINTK2(KERN_WARNING
1436 "ICMPv6 Redirect: destination address is multicast.\n");
1437 return;
1438 }
1439
1440 if (ipv6_addr_equal(dest, target)) {
1441 on_link = 1;
1442 } else if (ipv6_addr_type(target) !=
1443 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1444 ND_PRINTK2(KERN_WARNING
1445 "ICMPv6 Redirect: target address is not link-local unicast.\n");
1446 return;
1447 }
1448
1449 in6_dev = in6_dev_get(skb->dev);
1450 if (!in6_dev)
1451 return;
1452 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1453 in6_dev_put(in6_dev);
1454 return;
1455 }
1456
1457 /* RFC2461 8.1:
1458 * The IP source address of the Redirect MUST be the same as the current
1459 * first-hop router for the specified ICMP Destination Address.
1460 */
1461
1462 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1463 ND_PRINTK2(KERN_WARNING
1464 "ICMPv6 Redirect: invalid ND options\n");
1465 in6_dev_put(in6_dev);
1466 return;
1467 }
1468 if (ndopts.nd_opts_tgt_lladdr) {
1469 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1470 skb->dev);
1471 if (!lladdr) {
1472 ND_PRINTK2(KERN_WARNING
1473 "ICMPv6 Redirect: invalid link-layer address length\n");
1474 in6_dev_put(in6_dev);
1475 return;
1476 }
1477 }
1478
1479 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1480 if (neigh) {
1481 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1482 &ipv6_hdr(skb)->saddr, neigh, lladdr,
1483 on_link);
1484 neigh_release(neigh);
1485 }
1486 in6_dev_put(in6_dev);
1487 }
1488
1489 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1490 const struct in6_addr *target)
1491 {
1492 struct net_device *dev = skb->dev;
1493 struct net *net = dev_net(dev);
1494 struct sock *sk = net->ipv6.ndisc_sk;
1495 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1496 struct sk_buff *buff;
1497 struct icmp6hdr *icmph;
1498 struct in6_addr saddr_buf;
1499 struct in6_addr *addrp;
1500 struct rt6_info *rt;
1501 struct dst_entry *dst;
1502 struct inet6_dev *idev;
1503 struct flowi fl;
1504 u8 *opt;
1505 int rd_len;
1506 int err;
1507 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1508
1509 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1510 ND_PRINTK2(KERN_WARNING
1511 "ICMPv6 Redirect: no link-local address on %s\n",
1512 dev->name);
1513 return;
1514 }
1515
1516 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1517 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1518 ND_PRINTK2(KERN_WARNING
1519 "ICMPv6 Redirect: target address is not link-local unicast.\n");
1520 return;
1521 }
1522
1523 icmpv6_flow_init(sk, &fl, NDISC_REDIRECT,
1524 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1525
1526 dst = ip6_route_output(net, NULL, &fl);
1527 if (dst == NULL)
1528 return;
1529
1530 err = xfrm_lookup(net, &dst, &fl, NULL, 0);
1531 if (err)
1532 return;
1533
1534 rt = (struct rt6_info *) dst;
1535
1536 if (rt->rt6i_flags & RTF_GATEWAY) {
1537 ND_PRINTK2(KERN_WARNING
1538 "ICMPv6 Redirect: destination is not a neighbour.\n");
1539 goto release;
1540 }
1541 if (!xrlim_allow(dst, 1*HZ))
1542 goto release;
1543
1544 if (dev->addr_len) {
1545 read_lock_bh(&neigh->lock);
1546 if (neigh->nud_state & NUD_VALID) {
1547 memcpy(ha_buf, neigh->ha, dev->addr_len);
1548 read_unlock_bh(&neigh->lock);
1549 ha = ha_buf;
1550 len += ndisc_opt_addr_space(dev);
1551 } else
1552 read_unlock_bh(&neigh->lock);
1553 }
1554
1555 rd_len = min_t(unsigned int,
1556 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1557 rd_len &= ~0x7;
1558 len += rd_len;
1559
1560 buff = sock_alloc_send_skb(sk,
1561 (MAX_HEADER + sizeof(struct ipv6hdr) +
1562 len + LL_ALLOCATED_SPACE(dev)),
1563 1, &err);
1564 if (buff == NULL) {
1565 ND_PRINTK0(KERN_ERR
1566 "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1567 __func__, err);
1568 goto release;
1569 }
1570
1571 skb_reserve(buff, LL_RESERVED_SPACE(dev));
1572 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1573 IPPROTO_ICMPV6, len);
1574
1575 skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1576 skb_put(buff, len);
1577 icmph = icmp6_hdr(buff);
1578
1579 memset(icmph, 0, sizeof(struct icmp6hdr));
1580 icmph->icmp6_type = NDISC_REDIRECT;
1581
1582 /*
1583 * copy target and destination addresses
1584 */
1585
1586 addrp = (struct in6_addr *)(icmph + 1);
1587 ipv6_addr_copy(addrp, target);
1588 addrp++;
1589 ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1590
1591 opt = (u8*) (addrp + 1);
1592
1593 /*
1594 * include target_address option
1595 */
1596
1597 if (ha)
1598 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1599 dev->addr_len, dev->type);
1600
1601 /*
1602 * build redirect option and copy skb over to the new packet.
1603 */
1604
1605 memset(opt, 0, 8);
1606 *(opt++) = ND_OPT_REDIRECT_HDR;
1607 *(opt++) = (rd_len >> 3);
1608 opt += 6;
1609
1610 memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1611
1612 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1613 len, IPPROTO_ICMPV6,
1614 csum_partial(icmph, len, 0));
1615
1616 skb_dst_set(buff, dst);
1617 idev = in6_dev_get(dst->dev);
1618 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1619 err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1620 dst_output);
1621 if (!err) {
1622 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1623 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1624 }
1625
1626 if (likely(idev != NULL))
1627 in6_dev_put(idev);
1628 return;
1629
1630 release:
1631 dst_release(dst);
1632 }
1633
1634 static void pndisc_redo(struct sk_buff *skb)
1635 {
1636 ndisc_recv_ns(skb);
1637 kfree_skb(skb);
1638 }
1639
1640 int ndisc_rcv(struct sk_buff *skb)
1641 {
1642 struct nd_msg *msg;
1643
1644 if (!pskb_may_pull(skb, skb->len))
1645 return 0;
1646
1647 msg = (struct nd_msg *)skb_transport_header(skb);
1648
1649 __skb_push(skb, skb->data - skb_transport_header(skb));
1650
1651 if (ipv6_hdr(skb)->hop_limit != 255) {
1652 ND_PRINTK2(KERN_WARNING
1653 "ICMPv6 NDISC: invalid hop-limit: %d\n",
1654 ipv6_hdr(skb)->hop_limit);
1655 return 0;
1656 }
1657
1658 if (msg->icmph.icmp6_code != 0) {
1659 ND_PRINTK2(KERN_WARNING
1660 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1661 msg->icmph.icmp6_code);
1662 return 0;
1663 }
1664
1665 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1666
1667 switch (msg->icmph.icmp6_type) {
1668 case NDISC_NEIGHBOUR_SOLICITATION:
1669 ndisc_recv_ns(skb);
1670 break;
1671
1672 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1673 ndisc_recv_na(skb);
1674 break;
1675
1676 case NDISC_ROUTER_SOLICITATION:
1677 ndisc_recv_rs(skb);
1678 break;
1679
1680 case NDISC_ROUTER_ADVERTISEMENT:
1681 ndisc_router_discovery(skb);
1682 break;
1683
1684 case NDISC_REDIRECT:
1685 ndisc_redirect_rcv(skb);
1686 break;
1687 }
1688
1689 return 0;
1690 }
1691
1692 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1693 {
1694 struct net_device *dev = ptr;
1695 struct net *net = dev_net(dev);
1696
1697 switch (event) {
1698 case NETDEV_CHANGEADDR:
1699 neigh_changeaddr(&nd_tbl, dev);
1700 fib6_run_gc(~0UL, net);
1701 break;
1702 case NETDEV_DOWN:
1703 neigh_ifdown(&nd_tbl, dev);
1704 fib6_run_gc(~0UL, net);
1705 break;
1706 default:
1707 break;
1708 }
1709
1710 return NOTIFY_DONE;
1711 }
1712
1713 static struct notifier_block ndisc_netdev_notifier = {
1714 .notifier_call = ndisc_netdev_event,
1715 };
1716
1717 #ifdef CONFIG_SYSCTL
1718 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1719 const char *func, const char *dev_name)
1720 {
1721 static char warncomm[TASK_COMM_LEN];
1722 static int warned;
1723 if (strcmp(warncomm, current->comm) && warned < 5) {
1724 strcpy(warncomm, current->comm);
1725 printk(KERN_WARNING
1726 "process `%s' is using deprecated sysctl (%s) "
1727 "net.ipv6.neigh.%s.%s; "
1728 "Use net.ipv6.neigh.%s.%s_ms "
1729 "instead.\n",
1730 warncomm, func,
1731 dev_name, ctl->procname,
1732 dev_name, ctl->procname);
1733 warned++;
1734 }
1735 }
1736
1737 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1738 {
1739 struct net_device *dev = ctl->extra1;
1740 struct inet6_dev *idev;
1741 int ret;
1742
1743 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1744 (strcmp(ctl->procname, "base_reachable_time") == 0))
1745 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1746
1747 if (strcmp(ctl->procname, "retrans_time") == 0)
1748 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1749
1750 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1751 ret = proc_dointvec_jiffies(ctl, write,
1752 buffer, lenp, ppos);
1753
1754 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1755 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1756 ret = proc_dointvec_ms_jiffies(ctl, write,
1757 buffer, lenp, ppos);
1758 else
1759 ret = -1;
1760
1761 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1762 if (ctl->data == &idev->nd_parms->base_reachable_time)
1763 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1764 idev->tstamp = jiffies;
1765 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1766 in6_dev_put(idev);
1767 }
1768 return ret;
1769 }
1770
1771
1772 #endif
1773
1774 static int ndisc_net_init(struct net *net)
1775 {
1776 struct ipv6_pinfo *np;
1777 struct sock *sk;
1778 int err;
1779
1780 err = inet_ctl_sock_create(&sk, PF_INET6,
1781 SOCK_RAW, IPPROTO_ICMPV6, net);
1782 if (err < 0) {
1783 ND_PRINTK0(KERN_ERR
1784 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1785 err);
1786 return err;
1787 }
1788
1789 net->ipv6.ndisc_sk = sk;
1790
1791 np = inet6_sk(sk);
1792 np->hop_limit = 255;
1793 /* Do not loopback ndisc messages */
1794 np->mc_loop = 0;
1795
1796 return 0;
1797 }
1798
1799 static void ndisc_net_exit(struct net *net)
1800 {
1801 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1802 }
1803
1804 static struct pernet_operations ndisc_net_ops = {
1805 .init = ndisc_net_init,
1806 .exit = ndisc_net_exit,
1807 };
1808
1809 int __init ndisc_init(void)
1810 {
1811 int err;
1812
1813 err = register_pernet_subsys(&ndisc_net_ops);
1814 if (err)
1815 return err;
1816 /*
1817 * Initialize the neighbour table
1818 */
1819 neigh_table_init(&nd_tbl);
1820
1821 #ifdef CONFIG_SYSCTL
1822 err = neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6,
1823 NET_IPV6_NEIGH, "ipv6",
1824 &ndisc_ifinfo_sysctl_change);
1825 if (err)
1826 goto out_unregister_pernet;
1827 #endif
1828 err = register_netdevice_notifier(&ndisc_netdev_notifier);
1829 if (err)
1830 goto out_unregister_sysctl;
1831 out:
1832 return err;
1833
1834 out_unregister_sysctl:
1835 #ifdef CONFIG_SYSCTL
1836 neigh_sysctl_unregister(&nd_tbl.parms);
1837 out_unregister_pernet:
1838 #endif
1839 unregister_pernet_subsys(&ndisc_net_ops);
1840 goto out;
1841 }
1842
1843 void ndisc_cleanup(void)
1844 {
1845 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1846 #ifdef CONFIG_SYSCTL
1847 neigh_sysctl_unregister(&nd_tbl.parms);
1848 #endif
1849 neigh_table_clear(&nd_tbl);
1850 unregister_pernet_subsys(&ndisc_net_ops);
1851 }
Linux kernel - Deliverables
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