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net: remove k{un}map_skb_frag()
[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 #include <linux/slab.h>
63 #ifdef CONFIG_SYSCTL
64 #include <linux/sysctl.h>
65 #endif
66
67 #include <linux/if_addr.h>
68 #include <linux/if_arp.h>
69 #include <linux/ipv6.h>
70 #include <linux/icmpv6.h>
71 #include <linux/jhash.h>
72
73 #include <net/sock.h>
74 #include <net/snmp.h>
75
76 #include <net/ipv6.h>
77 #include <net/protocol.h>
78 #include <net/ndisc.h>
79 #include <net/ip6_route.h>
80 #include <net/addrconf.h>
81 #include <net/icmp.h>
82
83 #include <net/netlink.h>
84 #include <linux/rtnetlink.h>
85
86 #include <net/flow.h>
87 #include <net/ip6_checksum.h>
88 #include <net/inet_common.h>
89 #include <linux/proc_fs.h>
90
91 #include <linux/netfilter.h>
92 #include <linux/netfilter_ipv6.h>
93
94 static u32 ndisc_hash(const void *pkey,
95 const struct net_device *dev,
96 __u32 *hash_rnd);
97 static int ndisc_constructor(struct neighbour *neigh);
98 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
99 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
100 static int pndisc_constructor(struct pneigh_entry *n);
101 static void pndisc_destructor(struct pneigh_entry *n);
102 static void pndisc_redo(struct sk_buff *skb);
103
104 static const struct neigh_ops ndisc_generic_ops = {
105 .family = AF_INET6,
106 .solicit = ndisc_solicit,
107 .error_report = ndisc_error_report,
108 .output = neigh_resolve_output,
109 .connected_output = neigh_connected_output,
110 };
111
112 static const struct neigh_ops ndisc_hh_ops = {
113 .family = AF_INET6,
114 .solicit = ndisc_solicit,
115 .error_report = ndisc_error_report,
116 .output = neigh_resolve_output,
117 .connected_output = neigh_resolve_output,
118 };
119
120
121 static const struct neigh_ops ndisc_direct_ops = {
122 .family = AF_INET6,
123 .output = neigh_direct_output,
124 .connected_output = neigh_direct_output,
125 };
126
127 struct neigh_table nd_tbl = {
128 .family = AF_INET6,
129 .key_len = sizeof(struct in6_addr),
130 .hash = ndisc_hash,
131 .constructor = ndisc_constructor,
132 .pconstructor = pndisc_constructor,
133 .pdestructor = pndisc_destructor,
134 .proxy_redo = pndisc_redo,
135 .id = "ndisc_cache",
136 .parms = {
137 .tbl = &nd_tbl,
138 .base_reachable_time = ND_REACHABLE_TIME,
139 .retrans_time = ND_RETRANS_TIMER,
140 .gc_staletime = 60 * HZ,
141 .reachable_time = ND_REACHABLE_TIME,
142 .delay_probe_time = 5 * HZ,
143 .queue_len_bytes = 64*1024,
144 .ucast_probes = 3,
145 .mcast_probes = 3,
146 .anycast_delay = 1 * HZ,
147 .proxy_delay = (8 * HZ) / 10,
148 .proxy_qlen = 64,
149 },
150 .gc_interval = 30 * HZ,
151 .gc_thresh1 = 128,
152 .gc_thresh2 = 512,
153 .gc_thresh3 = 1024,
154 };
155
156 /* ND options */
157 struct ndisc_options {
158 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
159 #ifdef CONFIG_IPV6_ROUTE_INFO
160 struct nd_opt_hdr *nd_opts_ri;
161 struct nd_opt_hdr *nd_opts_ri_end;
162 #endif
163 struct nd_opt_hdr *nd_useropts;
164 struct nd_opt_hdr *nd_useropts_end;
165 };
166
167 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
168 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR]
169 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO]
170 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
171 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
172 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
173
174 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
175
176 /*
177 * Return the padding between the option length and the start of the
178 * link addr. Currently only IP-over-InfiniBand needs this, although
179 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
180 * also need a pad of 2.
181 */
182 static int ndisc_addr_option_pad(unsigned short type)
183 {
184 switch (type) {
185 case ARPHRD_INFINIBAND: return 2;
186 default: return 0;
187 }
188 }
189
190 static inline int ndisc_opt_addr_space(struct net_device *dev)
191 {
192 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
193 }
194
195 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
196 unsigned short addr_type)
197 {
198 int space = NDISC_OPT_SPACE(data_len);
199 int pad = ndisc_addr_option_pad(addr_type);
200
201 opt[0] = type;
202 opt[1] = space>>3;
203
204 memset(opt + 2, 0, pad);
205 opt += pad;
206 space -= pad;
207
208 memcpy(opt+2, data, data_len);
209 data_len += 2;
210 opt += data_len;
211 if ((space -= data_len) > 0)
212 memset(opt, 0, space);
213 return opt + space;
214 }
215
216 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
217 struct nd_opt_hdr *end)
218 {
219 int type;
220 if (!cur || !end || cur >= end)
221 return NULL;
222 type = cur->nd_opt_type;
223 do {
224 cur = ((void *)cur) + (cur->nd_opt_len << 3);
225 } while(cur < end && cur->nd_opt_type != type);
226 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
227 }
228
229 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
230 {
231 return opt->nd_opt_type == ND_OPT_RDNSS;
232 }
233
234 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
235 struct nd_opt_hdr *end)
236 {
237 if (!cur || !end || cur >= end)
238 return NULL;
239 do {
240 cur = ((void *)cur) + (cur->nd_opt_len << 3);
241 } while(cur < end && !ndisc_is_useropt(cur));
242 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
243 }
244
245 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
246 struct ndisc_options *ndopts)
247 {
248 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
249
250 if (!nd_opt || opt_len < 0 || !ndopts)
251 return NULL;
252 memset(ndopts, 0, sizeof(*ndopts));
253 while (opt_len) {
254 int l;
255 if (opt_len < sizeof(struct nd_opt_hdr))
256 return NULL;
257 l = nd_opt->nd_opt_len << 3;
258 if (opt_len < l || l == 0)
259 return NULL;
260 switch (nd_opt->nd_opt_type) {
261 case ND_OPT_SOURCE_LL_ADDR:
262 case ND_OPT_TARGET_LL_ADDR:
263 case ND_OPT_MTU:
264 case ND_OPT_REDIRECT_HDR:
265 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
266 ND_PRINTK2(KERN_WARNING
267 "%s(): duplicated ND6 option found: type=%d\n",
268 __func__,
269 nd_opt->nd_opt_type);
270 } else {
271 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
272 }
273 break;
274 case ND_OPT_PREFIX_INFO:
275 ndopts->nd_opts_pi_end = nd_opt;
276 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
277 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
278 break;
279 #ifdef CONFIG_IPV6_ROUTE_INFO
280 case ND_OPT_ROUTE_INFO:
281 ndopts->nd_opts_ri_end = nd_opt;
282 if (!ndopts->nd_opts_ri)
283 ndopts->nd_opts_ri = nd_opt;
284 break;
285 #endif
286 default:
287 if (ndisc_is_useropt(nd_opt)) {
288 ndopts->nd_useropts_end = nd_opt;
289 if (!ndopts->nd_useropts)
290 ndopts->nd_useropts = nd_opt;
291 } else {
292 /*
293 * Unknown options must be silently ignored,
294 * to accommodate future extension to the
295 * protocol.
296 */
297 ND_PRINTK2(KERN_NOTICE
298 "%s(): ignored unsupported option; type=%d, len=%d\n",
299 __func__,
300 nd_opt->nd_opt_type, nd_opt->nd_opt_len);
301 }
302 }
303 opt_len -= l;
304 nd_opt = ((void *)nd_opt) + l;
305 }
306 return ndopts;
307 }
308
309 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
310 struct net_device *dev)
311 {
312 u8 *lladdr = (u8 *)(p + 1);
313 int lladdrlen = p->nd_opt_len << 3;
314 int prepad = ndisc_addr_option_pad(dev->type);
315 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
316 return NULL;
317 return lladdr + prepad;
318 }
319
320 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
321 {
322 switch (dev->type) {
323 case ARPHRD_ETHER:
324 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
325 case ARPHRD_FDDI:
326 ipv6_eth_mc_map(addr, buf);
327 return 0;
328 case ARPHRD_IEEE802_TR:
329 ipv6_tr_mc_map(addr,buf);
330 return 0;
331 case ARPHRD_ARCNET:
332 ipv6_arcnet_mc_map(addr, buf);
333 return 0;
334 case ARPHRD_INFINIBAND:
335 ipv6_ib_mc_map(addr, dev->broadcast, buf);
336 return 0;
337 case ARPHRD_IPGRE:
338 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
339 default:
340 if (dir) {
341 memcpy(buf, dev->broadcast, dev->addr_len);
342 return 0;
343 }
344 }
345 return -EINVAL;
346 }
347
348 EXPORT_SYMBOL(ndisc_mc_map);
349
350 static u32 ndisc_hash(const void *pkey,
351 const struct net_device *dev,
352 __u32 *hash_rnd)
353 {
354 return ndisc_hashfn(pkey, dev, hash_rnd);
355 }
356
357 static int ndisc_constructor(struct neighbour *neigh)
358 {
359 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
360 struct net_device *dev = neigh->dev;
361 struct inet6_dev *in6_dev;
362 struct neigh_parms *parms;
363 int is_multicast = ipv6_addr_is_multicast(addr);
364
365 in6_dev = in6_dev_get(dev);
366 if (in6_dev == NULL) {
367 return -EINVAL;
368 }
369
370 parms = in6_dev->nd_parms;
371 __neigh_parms_put(neigh->parms);
372 neigh->parms = neigh_parms_clone(parms);
373
374 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
375 if (!dev->header_ops) {
376 neigh->nud_state = NUD_NOARP;
377 neigh->ops = &ndisc_direct_ops;
378 neigh->output = neigh_direct_output;
379 } else {
380 if (is_multicast) {
381 neigh->nud_state = NUD_NOARP;
382 ndisc_mc_map(addr, neigh->ha, dev, 1);
383 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
384 neigh->nud_state = NUD_NOARP;
385 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
386 if (dev->flags&IFF_LOOPBACK)
387 neigh->type = RTN_LOCAL;
388 } else if (dev->flags&IFF_POINTOPOINT) {
389 neigh->nud_state = NUD_NOARP;
390 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
391 }
392 if (dev->header_ops->cache)
393 neigh->ops = &ndisc_hh_ops;
394 else
395 neigh->ops = &ndisc_generic_ops;
396 if (neigh->nud_state&NUD_VALID)
397 neigh->output = neigh->ops->connected_output;
398 else
399 neigh->output = neigh->ops->output;
400 }
401 in6_dev_put(in6_dev);
402 return 0;
403 }
404
405 static int pndisc_constructor(struct pneigh_entry *n)
406 {
407 struct in6_addr *addr = (struct in6_addr*)&n->key;
408 struct in6_addr maddr;
409 struct net_device *dev = n->dev;
410
411 if (dev == NULL || __in6_dev_get(dev) == NULL)
412 return -EINVAL;
413 addrconf_addr_solict_mult(addr, &maddr);
414 ipv6_dev_mc_inc(dev, &maddr);
415 return 0;
416 }
417
418 static void pndisc_destructor(struct pneigh_entry *n)
419 {
420 struct in6_addr *addr = (struct in6_addr*)&n->key;
421 struct in6_addr maddr;
422 struct net_device *dev = n->dev;
423
424 if (dev == NULL || __in6_dev_get(dev) == NULL)
425 return;
426 addrconf_addr_solict_mult(addr, &maddr);
427 ipv6_dev_mc_dec(dev, &maddr);
428 }
429
430 struct sk_buff *ndisc_build_skb(struct net_device *dev,
431 const struct in6_addr *daddr,
432 const struct in6_addr *saddr,
433 struct icmp6hdr *icmp6h,
434 const struct in6_addr *target,
435 int llinfo)
436 {
437 struct net *net = dev_net(dev);
438 struct sock *sk = net->ipv6.ndisc_sk;
439 struct sk_buff *skb;
440 struct icmp6hdr *hdr;
441 int hlen = LL_RESERVED_SPACE(dev);
442 int tlen = dev->needed_tailroom;
443 int len;
444 int err;
445 u8 *opt;
446
447 if (!dev->addr_len)
448 llinfo = 0;
449
450 len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
451 if (llinfo)
452 len += ndisc_opt_addr_space(dev);
453
454 skb = sock_alloc_send_skb(sk,
455 (MAX_HEADER + sizeof(struct ipv6hdr) +
456 len + hlen + tlen),
457 1, &err);
458 if (!skb) {
459 ND_PRINTK0(KERN_ERR
460 "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
461 __func__, err);
462 return NULL;
463 }
464
465 skb_reserve(skb, hlen);
466 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
467
468 skb->transport_header = skb->tail;
469 skb_put(skb, len);
470
471 hdr = (struct icmp6hdr *)skb_transport_header(skb);
472 memcpy(hdr, icmp6h, sizeof(*hdr));
473
474 opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
475 if (target) {
476 *(struct in6_addr *)opt = *target;
477 opt += sizeof(*target);
478 }
479
480 if (llinfo)
481 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
482 dev->addr_len, dev->type);
483
484 hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
485 IPPROTO_ICMPV6,
486 csum_partial(hdr,
487 len, 0));
488
489 return skb;
490 }
491
492 EXPORT_SYMBOL(ndisc_build_skb);
493
494 void ndisc_send_skb(struct sk_buff *skb,
495 struct net_device *dev,
496 struct neighbour *neigh,
497 const struct in6_addr *daddr,
498 const struct in6_addr *saddr,
499 struct icmp6hdr *icmp6h)
500 {
501 struct flowi6 fl6;
502 struct dst_entry *dst;
503 struct net *net = dev_net(dev);
504 struct sock *sk = net->ipv6.ndisc_sk;
505 struct inet6_dev *idev;
506 int err;
507 u8 type;
508
509 type = icmp6h->icmp6_type;
510
511 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, dev->ifindex);
512 dst = icmp6_dst_alloc(dev, neigh, &fl6);
513 if (IS_ERR(dst)) {
514 kfree_skb(skb);
515 return;
516 }
517
518 skb_dst_set(skb, dst);
519
520 rcu_read_lock();
521 idev = __in6_dev_get(dst->dev);
522 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
523
524 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
525 dst_output);
526 if (!err) {
527 ICMP6MSGOUT_INC_STATS(net, idev, type);
528 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
529 }
530
531 rcu_read_unlock();
532 }
533
534 EXPORT_SYMBOL(ndisc_send_skb);
535
536 /*
537 * Send a Neighbour Discover packet
538 */
539 static void __ndisc_send(struct net_device *dev,
540 struct neighbour *neigh,
541 const struct in6_addr *daddr,
542 const struct in6_addr *saddr,
543 struct icmp6hdr *icmp6h, const struct in6_addr *target,
544 int llinfo)
545 {
546 struct sk_buff *skb;
547
548 skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
549 if (!skb)
550 return;
551
552 ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
553 }
554
555 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
556 const struct in6_addr *daddr,
557 const struct in6_addr *solicited_addr,
558 int router, int solicited, int override, int inc_opt)
559 {
560 struct in6_addr tmpaddr;
561 struct inet6_ifaddr *ifp;
562 const struct in6_addr *src_addr;
563 struct icmp6hdr icmp6h = {
564 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
565 };
566
567 /* for anycast or proxy, solicited_addr != src_addr */
568 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
569 if (ifp) {
570 src_addr = solicited_addr;
571 if (ifp->flags & IFA_F_OPTIMISTIC)
572 override = 0;
573 inc_opt |= ifp->idev->cnf.force_tllao;
574 in6_ifa_put(ifp);
575 } else {
576 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
577 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
578 &tmpaddr))
579 return;
580 src_addr = &tmpaddr;
581 }
582
583 icmp6h.icmp6_router = router;
584 icmp6h.icmp6_solicited = solicited;
585 icmp6h.icmp6_override = override;
586
587 __ndisc_send(dev, neigh, daddr, src_addr,
588 &icmp6h, solicited_addr,
589 inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
590 }
591
592 static void ndisc_send_unsol_na(struct net_device *dev)
593 {
594 struct inet6_dev *idev;
595 struct inet6_ifaddr *ifa;
596 struct in6_addr mcaddr;
597
598 idev = in6_dev_get(dev);
599 if (!idev)
600 return;
601
602 read_lock_bh(&idev->lock);
603 list_for_each_entry(ifa, &idev->addr_list, if_list) {
604 addrconf_addr_solict_mult(&ifa->addr, &mcaddr);
605 ndisc_send_na(dev, NULL, &mcaddr, &ifa->addr,
606 /*router=*/ !!idev->cnf.forwarding,
607 /*solicited=*/ false, /*override=*/ true,
608 /*inc_opt=*/ true);
609 }
610 read_unlock_bh(&idev->lock);
611
612 in6_dev_put(idev);
613 }
614
615 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
616 const struct in6_addr *solicit,
617 const struct in6_addr *daddr, const struct in6_addr *saddr)
618 {
619 struct in6_addr addr_buf;
620 struct icmp6hdr icmp6h = {
621 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
622 };
623
624 if (saddr == NULL) {
625 if (ipv6_get_lladdr(dev, &addr_buf,
626 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
627 return;
628 saddr = &addr_buf;
629 }
630
631 __ndisc_send(dev, neigh, daddr, saddr,
632 &icmp6h, solicit,
633 !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
634 }
635
636 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
637 const struct in6_addr *daddr)
638 {
639 struct icmp6hdr icmp6h = {
640 .icmp6_type = NDISC_ROUTER_SOLICITATION,
641 };
642 int send_sllao = dev->addr_len;
643
644 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
645 /*
646 * According to section 2.2 of RFC 4429, we must not
647 * send router solicitations with a sllao from
648 * optimistic addresses, but we may send the solicitation
649 * if we don't include the sllao. So here we check
650 * if our address is optimistic, and if so, we
651 * suppress the inclusion of the sllao.
652 */
653 if (send_sllao) {
654 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
655 dev, 1);
656 if (ifp) {
657 if (ifp->flags & IFA_F_OPTIMISTIC) {
658 send_sllao = 0;
659 }
660 in6_ifa_put(ifp);
661 } else {
662 send_sllao = 0;
663 }
664 }
665 #endif
666 __ndisc_send(dev, NULL, daddr, saddr,
667 &icmp6h, NULL,
668 send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
669 }
670
671
672 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
673 {
674 /*
675 * "The sender MUST return an ICMP
676 * destination unreachable"
677 */
678 dst_link_failure(skb);
679 kfree_skb(skb);
680 }
681
682 /* Called with locked neigh: either read or both */
683
684 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
685 {
686 struct in6_addr *saddr = NULL;
687 struct in6_addr mcaddr;
688 struct net_device *dev = neigh->dev;
689 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
690 int probes = atomic_read(&neigh->probes);
691
692 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
693 saddr = &ipv6_hdr(skb)->saddr;
694
695 if ((probes -= neigh->parms->ucast_probes) < 0) {
696 if (!(neigh->nud_state & NUD_VALID)) {
697 ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
698 __func__, target);
699 }
700 ndisc_send_ns(dev, neigh, target, target, saddr);
701 } else if ((probes -= neigh->parms->app_probes) < 0) {
702 #ifdef CONFIG_ARPD
703 neigh_app_ns(neigh);
704 #endif
705 } else {
706 addrconf_addr_solict_mult(target, &mcaddr);
707 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
708 }
709 }
710
711 static int pndisc_is_router(const void *pkey,
712 struct net_device *dev)
713 {
714 struct pneigh_entry *n;
715 int ret = -1;
716
717 read_lock_bh(&nd_tbl.lock);
718 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
719 if (n)
720 ret = !!(n->flags & NTF_ROUTER);
721 read_unlock_bh(&nd_tbl.lock);
722
723 return ret;
724 }
725
726 static void ndisc_recv_ns(struct sk_buff *skb)
727 {
728 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
729 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
730 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
731 u8 *lladdr = NULL;
732 u32 ndoptlen = skb->tail - (skb->transport_header +
733 offsetof(struct nd_msg, opt));
734 struct ndisc_options ndopts;
735 struct net_device *dev = skb->dev;
736 struct inet6_ifaddr *ifp;
737 struct inet6_dev *idev = NULL;
738 struct neighbour *neigh;
739 int dad = ipv6_addr_any(saddr);
740 int inc;
741 int is_router = -1;
742
743 if (ipv6_addr_is_multicast(&msg->target)) {
744 ND_PRINTK2(KERN_WARNING
745 "ICMPv6 NS: multicast target address");
746 return;
747 }
748
749 /*
750 * RFC2461 7.1.1:
751 * DAD has to be destined for solicited node multicast address.
752 */
753 if (dad &&
754 !(daddr->s6_addr32[0] == htonl(0xff020000) &&
755 daddr->s6_addr32[1] == htonl(0x00000000) &&
756 daddr->s6_addr32[2] == htonl(0x00000001) &&
757 daddr->s6_addr [12] == 0xff )) {
758 ND_PRINTK2(KERN_WARNING
759 "ICMPv6 NS: bad DAD packet (wrong destination)\n");
760 return;
761 }
762
763 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
764 ND_PRINTK2(KERN_WARNING
765 "ICMPv6 NS: invalid ND options\n");
766 return;
767 }
768
769 if (ndopts.nd_opts_src_lladdr) {
770 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
771 if (!lladdr) {
772 ND_PRINTK2(KERN_WARNING
773 "ICMPv6 NS: invalid link-layer address length\n");
774 return;
775 }
776
777 /* RFC2461 7.1.1:
778 * If the IP source address is the unspecified address,
779 * there MUST NOT be source link-layer address option
780 * in the message.
781 */
782 if (dad) {
783 ND_PRINTK2(KERN_WARNING
784 "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
785 return;
786 }
787 }
788
789 inc = ipv6_addr_is_multicast(daddr);
790
791 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
792 if (ifp) {
793
794 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
795 if (dad) {
796 if (dev->type == ARPHRD_IEEE802_TR) {
797 const unsigned char *sadr;
798 sadr = skb_mac_header(skb);
799 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
800 sadr[9] == dev->dev_addr[1] &&
801 sadr[10] == dev->dev_addr[2] &&
802 sadr[11] == dev->dev_addr[3] &&
803 sadr[12] == dev->dev_addr[4] &&
804 sadr[13] == dev->dev_addr[5]) {
805 /* looped-back to us */
806 goto out;
807 }
808 }
809
810 /*
811 * We are colliding with another node
812 * who is doing DAD
813 * so fail our DAD process
814 */
815 addrconf_dad_failure(ifp);
816 return;
817 } else {
818 /*
819 * This is not a dad solicitation.
820 * If we are an optimistic node,
821 * we should respond.
822 * Otherwise, we should ignore it.
823 */
824 if (!(ifp->flags & IFA_F_OPTIMISTIC))
825 goto out;
826 }
827 }
828
829 idev = ifp->idev;
830 } else {
831 struct net *net = dev_net(dev);
832
833 idev = in6_dev_get(dev);
834 if (!idev) {
835 /* XXX: count this drop? */
836 return;
837 }
838
839 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
840 (idev->cnf.forwarding &&
841 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
842 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
843 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
844 skb->pkt_type != PACKET_HOST &&
845 inc != 0 &&
846 idev->nd_parms->proxy_delay != 0) {
847 /*
848 * for anycast or proxy,
849 * sender should delay its response
850 * by a random time between 0 and
851 * MAX_ANYCAST_DELAY_TIME seconds.
852 * (RFC2461) -- yoshfuji
853 */
854 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
855 if (n)
856 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
857 goto out;
858 }
859 } else
860 goto out;
861 }
862
863 if (is_router < 0)
864 is_router = !!idev->cnf.forwarding;
865
866 if (dad) {
867 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
868 is_router, 0, (ifp != NULL), 1);
869 goto out;
870 }
871
872 if (inc)
873 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
874 else
875 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
876
877 /*
878 * update / create cache entry
879 * for the source address
880 */
881 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
882 !inc || lladdr || !dev->addr_len);
883 if (neigh)
884 neigh_update(neigh, lladdr, NUD_STALE,
885 NEIGH_UPDATE_F_WEAK_OVERRIDE|
886 NEIGH_UPDATE_F_OVERRIDE);
887 if (neigh || !dev->header_ops) {
888 ndisc_send_na(dev, neigh, saddr, &msg->target,
889 is_router,
890 1, (ifp != NULL && inc), inc);
891 if (neigh)
892 neigh_release(neigh);
893 }
894
895 out:
896 if (ifp)
897 in6_ifa_put(ifp);
898 else
899 in6_dev_put(idev);
900 }
901
902 static void ndisc_recv_na(struct sk_buff *skb)
903 {
904 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
905 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
906 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
907 u8 *lladdr = NULL;
908 u32 ndoptlen = skb->tail - (skb->transport_header +
909 offsetof(struct nd_msg, opt));
910 struct ndisc_options ndopts;
911 struct net_device *dev = skb->dev;
912 struct inet6_ifaddr *ifp;
913 struct neighbour *neigh;
914
915 if (skb->len < sizeof(struct nd_msg)) {
916 ND_PRINTK2(KERN_WARNING
917 "ICMPv6 NA: packet too short\n");
918 return;
919 }
920
921 if (ipv6_addr_is_multicast(&msg->target)) {
922 ND_PRINTK2(KERN_WARNING
923 "ICMPv6 NA: target address is multicast.\n");
924 return;
925 }
926
927 if (ipv6_addr_is_multicast(daddr) &&
928 msg->icmph.icmp6_solicited) {
929 ND_PRINTK2(KERN_WARNING
930 "ICMPv6 NA: solicited NA is multicasted.\n");
931 return;
932 }
933
934 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
935 ND_PRINTK2(KERN_WARNING
936 "ICMPv6 NS: invalid ND option\n");
937 return;
938 }
939 if (ndopts.nd_opts_tgt_lladdr) {
940 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
941 if (!lladdr) {
942 ND_PRINTK2(KERN_WARNING
943 "ICMPv6 NA: invalid link-layer address length\n");
944 return;
945 }
946 }
947 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
948 if (ifp) {
949 if (skb->pkt_type != PACKET_LOOPBACK
950 && (ifp->flags & IFA_F_TENTATIVE)) {
951 addrconf_dad_failure(ifp);
952 return;
953 }
954 /* What should we make now? The advertisement
955 is invalid, but ndisc specs say nothing
956 about it. It could be misconfiguration, or
957 an smart proxy agent tries to help us :-)
958
959 We should not print the error if NA has been
960 received from loopback - it is just our own
961 unsolicited advertisement.
962 */
963 if (skb->pkt_type != PACKET_LOOPBACK)
964 ND_PRINTK1(KERN_WARNING
965 "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
966 &ifp->addr, ifp->idev->dev->name);
967 in6_ifa_put(ifp);
968 return;
969 }
970 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
971
972 if (neigh) {
973 u8 old_flags = neigh->flags;
974 struct net *net = dev_net(dev);
975
976 if (neigh->nud_state & NUD_FAILED)
977 goto out;
978
979 /*
980 * Don't update the neighbor cache entry on a proxy NA from
981 * ourselves because either the proxied node is off link or it
982 * has already sent a NA to us.
983 */
984 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
985 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
986 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
987 /* XXX: idev->cnf.prixy_ndp */
988 goto out;
989 }
990
991 neigh_update(neigh, lladdr,
992 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
993 NEIGH_UPDATE_F_WEAK_OVERRIDE|
994 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
995 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
996 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
997
998 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
999 /*
1000 * Change: router to host
1001 */
1002 struct rt6_info *rt;
1003 rt = rt6_get_dflt_router(saddr, dev);
1004 if (rt)
1005 ip6_del_rt(rt);
1006 }
1007
1008 out:
1009 neigh_release(neigh);
1010 }
1011 }
1012
1013 static void ndisc_recv_rs(struct sk_buff *skb)
1014 {
1015 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1016 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1017 struct neighbour *neigh;
1018 struct inet6_dev *idev;
1019 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1020 struct ndisc_options ndopts;
1021 u8 *lladdr = NULL;
1022
1023 if (skb->len < sizeof(*rs_msg))
1024 return;
1025
1026 idev = __in6_dev_get(skb->dev);
1027 if (!idev) {
1028 if (net_ratelimit())
1029 ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1030 return;
1031 }
1032
1033 /* Don't accept RS if we're not in router mode */
1034 if (!idev->cnf.forwarding)
1035 goto out;
1036
1037 /*
1038 * Don't update NCE if src = ::;
1039 * this implies that the source node has no ip address assigned yet.
1040 */
1041 if (ipv6_addr_any(saddr))
1042 goto out;
1043
1044 /* Parse ND options */
1045 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1046 if (net_ratelimit())
1047 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1048 goto out;
1049 }
1050
1051 if (ndopts.nd_opts_src_lladdr) {
1052 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1053 skb->dev);
1054 if (!lladdr)
1055 goto out;
1056 }
1057
1058 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1059 if (neigh) {
1060 neigh_update(neigh, lladdr, NUD_STALE,
1061 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1062 NEIGH_UPDATE_F_OVERRIDE|
1063 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1064 neigh_release(neigh);
1065 }
1066 out:
1067 return;
1068 }
1069
1070 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1071 {
1072 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1073 struct sk_buff *skb;
1074 struct nlmsghdr *nlh;
1075 struct nduseroptmsg *ndmsg;
1076 struct net *net = dev_net(ra->dev);
1077 int err;
1078 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1079 + (opt->nd_opt_len << 3));
1080 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1081
1082 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1083 if (skb == NULL) {
1084 err = -ENOBUFS;
1085 goto errout;
1086 }
1087
1088 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1089 if (nlh == NULL) {
1090 goto nla_put_failure;
1091 }
1092
1093 ndmsg = nlmsg_data(nlh);
1094 ndmsg->nduseropt_family = AF_INET6;
1095 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1096 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1097 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1098 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1099
1100 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1101
1102 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1103 &ipv6_hdr(ra)->saddr))
1104 goto nla_put_failure;
1105 nlmsg_end(skb, nlh);
1106
1107 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1108 return;
1109
1110 nla_put_failure:
1111 nlmsg_free(skb);
1112 err = -EMSGSIZE;
1113 errout:
1114 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1115 }
1116
1117 static inline int accept_ra(struct inet6_dev *in6_dev)
1118 {
1119 /*
1120 * If forwarding is enabled, RA are not accepted unless the special
1121 * hybrid mode (accept_ra=2) is enabled.
1122 */
1123 if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2)
1124 return 0;
1125
1126 return in6_dev->cnf.accept_ra;
1127 }
1128
1129 static void ndisc_router_discovery(struct sk_buff *skb)
1130 {
1131 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1132 struct neighbour *neigh = NULL;
1133 struct inet6_dev *in6_dev;
1134 struct rt6_info *rt = NULL;
1135 int lifetime;
1136 struct ndisc_options ndopts;
1137 int optlen;
1138 unsigned int pref = 0;
1139
1140 __u8 * opt = (__u8 *)(ra_msg + 1);
1141
1142 optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
1143
1144 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1145 ND_PRINTK2(KERN_WARNING
1146 "ICMPv6 RA: source address is not link-local.\n");
1147 return;
1148 }
1149 if (optlen < 0) {
1150 ND_PRINTK2(KERN_WARNING
1151 "ICMPv6 RA: packet too short\n");
1152 return;
1153 }
1154
1155 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1156 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1157 ND_PRINTK2(KERN_WARNING
1158 "ICMPv6 RA: from host or unauthorized router\n");
1159 return;
1160 }
1161 #endif
1162
1163 /*
1164 * set the RA_RECV flag in the interface
1165 */
1166
1167 in6_dev = __in6_dev_get(skb->dev);
1168 if (in6_dev == NULL) {
1169 ND_PRINTK0(KERN_ERR
1170 "ICMPv6 RA: can't find inet6 device for %s.\n",
1171 skb->dev->name);
1172 return;
1173 }
1174
1175 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1176 ND_PRINTK2(KERN_WARNING
1177 "ICMP6 RA: invalid ND options\n");
1178 return;
1179 }
1180
1181 if (!accept_ra(in6_dev))
1182 goto skip_linkparms;
1183
1184 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1185 /* skip link-specific parameters from interior routers */
1186 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1187 goto skip_linkparms;
1188 #endif
1189
1190 if (in6_dev->if_flags & IF_RS_SENT) {
1191 /*
1192 * flag that an RA was received after an RS was sent
1193 * out on this interface.
1194 */
1195 in6_dev->if_flags |= IF_RA_RCVD;
1196 }
1197
1198 /*
1199 * Remember the managed/otherconf flags from most recently
1200 * received RA message (RFC 2462) -- yoshfuji
1201 */
1202 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1203 IF_RA_OTHERCONF)) |
1204 (ra_msg->icmph.icmp6_addrconf_managed ?
1205 IF_RA_MANAGED : 0) |
1206 (ra_msg->icmph.icmp6_addrconf_other ?
1207 IF_RA_OTHERCONF : 0);
1208
1209 if (!in6_dev->cnf.accept_ra_defrtr)
1210 goto skip_defrtr;
1211
1212 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1213 goto skip_defrtr;
1214
1215 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1216
1217 #ifdef CONFIG_IPV6_ROUTER_PREF
1218 pref = ra_msg->icmph.icmp6_router_pref;
1219 /* 10b is handled as if it were 00b (medium) */
1220 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1221 !in6_dev->cnf.accept_ra_rtr_pref)
1222 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1223 #endif
1224
1225 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1226
1227 if (rt) {
1228 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1229 if (!neigh) {
1230 ND_PRINTK0(KERN_ERR
1231 "ICMPv6 RA: %s() got default router without neighbour.\n",
1232 __func__);
1233 dst_release(&rt->dst);
1234 return;
1235 }
1236 }
1237 if (rt && lifetime == 0) {
1238 ip6_del_rt(rt);
1239 rt = NULL;
1240 }
1241
1242 if (rt == NULL && lifetime) {
1243 ND_PRINTK3(KERN_DEBUG
1244 "ICMPv6 RA: adding default router.\n");
1245
1246 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1247 if (rt == NULL) {
1248 ND_PRINTK0(KERN_ERR
1249 "ICMPv6 RA: %s() failed to add default route.\n",
1250 __func__);
1251 return;
1252 }
1253
1254 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
1255 if (neigh == NULL) {
1256 ND_PRINTK0(KERN_ERR
1257 "ICMPv6 RA: %s() got default router without neighbour.\n",
1258 __func__);
1259 dst_release(&rt->dst);
1260 return;
1261 }
1262 neigh->flags |= NTF_ROUTER;
1263 } else if (rt) {
1264 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1265 }
1266
1267 if (rt)
1268 rt->dst.expires = jiffies + (HZ * lifetime);
1269
1270 if (ra_msg->icmph.icmp6_hop_limit) {
1271 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1272 if (rt)
1273 dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1274 ra_msg->icmph.icmp6_hop_limit);
1275 }
1276
1277 skip_defrtr:
1278
1279 /*
1280 * Update Reachable Time and Retrans Timer
1281 */
1282
1283 if (in6_dev->nd_parms) {
1284 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1285
1286 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1287 rtime = (rtime*HZ)/1000;
1288 if (rtime < HZ/10)
1289 rtime = HZ/10;
1290 in6_dev->nd_parms->retrans_time = rtime;
1291 in6_dev->tstamp = jiffies;
1292 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1293 }
1294
1295 rtime = ntohl(ra_msg->reachable_time);
1296 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1297 rtime = (rtime*HZ)/1000;
1298
1299 if (rtime < HZ/10)
1300 rtime = HZ/10;
1301
1302 if (rtime != in6_dev->nd_parms->base_reachable_time) {
1303 in6_dev->nd_parms->base_reachable_time = rtime;
1304 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1305 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1306 in6_dev->tstamp = jiffies;
1307 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1308 }
1309 }
1310 }
1311
1312 skip_linkparms:
1313
1314 /*
1315 * Process options.
1316 */
1317
1318 if (!neigh)
1319 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1320 skb->dev, 1);
1321 if (neigh) {
1322 u8 *lladdr = NULL;
1323 if (ndopts.nd_opts_src_lladdr) {
1324 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1325 skb->dev);
1326 if (!lladdr) {
1327 ND_PRINTK2(KERN_WARNING
1328 "ICMPv6 RA: invalid link-layer address length\n");
1329 goto out;
1330 }
1331 }
1332 neigh_update(neigh, lladdr, NUD_STALE,
1333 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1334 NEIGH_UPDATE_F_OVERRIDE|
1335 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1336 NEIGH_UPDATE_F_ISROUTER);
1337 }
1338
1339 if (!accept_ra(in6_dev))
1340 goto out;
1341
1342 #ifdef CONFIG_IPV6_ROUTE_INFO
1343 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0))
1344 goto skip_routeinfo;
1345
1346 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1347 struct nd_opt_hdr *p;
1348 for (p = ndopts.nd_opts_ri;
1349 p;
1350 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1351 struct route_info *ri = (struct route_info *)p;
1352 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1353 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1354 ri->prefix_len == 0)
1355 continue;
1356 #endif
1357 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1358 continue;
1359 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1360 &ipv6_hdr(skb)->saddr);
1361 }
1362 }
1363
1364 skip_routeinfo:
1365 #endif
1366
1367 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1368 /* skip link-specific ndopts from interior routers */
1369 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
1370 goto out;
1371 #endif
1372
1373 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1374 struct nd_opt_hdr *p;
1375 for (p = ndopts.nd_opts_pi;
1376 p;
1377 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1378 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1379 (p->nd_opt_len) << 3,
1380 ndopts.nd_opts_src_lladdr != NULL);
1381 }
1382 }
1383
1384 if (ndopts.nd_opts_mtu) {
1385 __be32 n;
1386 u32 mtu;
1387
1388 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1389 mtu = ntohl(n);
1390
1391 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1392 ND_PRINTK2(KERN_WARNING
1393 "ICMPv6 RA: invalid mtu: %d\n",
1394 mtu);
1395 } else if (in6_dev->cnf.mtu6 != mtu) {
1396 in6_dev->cnf.mtu6 = mtu;
1397
1398 if (rt)
1399 dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1400
1401 rt6_mtu_change(skb->dev, mtu);
1402 }
1403 }
1404
1405 if (ndopts.nd_useropts) {
1406 struct nd_opt_hdr *p;
1407 for (p = ndopts.nd_useropts;
1408 p;
1409 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
1410 ndisc_ra_useropt(skb, p);
1411 }
1412 }
1413
1414 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1415 ND_PRINTK2(KERN_WARNING
1416 "ICMPv6 RA: invalid RA options");
1417 }
1418 out:
1419 if (rt)
1420 dst_release(&rt->dst);
1421 if (neigh)
1422 neigh_release(neigh);
1423 }
1424
1425 static void ndisc_redirect_rcv(struct sk_buff *skb)
1426 {
1427 struct inet6_dev *in6_dev;
1428 struct icmp6hdr *icmph;
1429 const struct in6_addr *dest;
1430 const struct in6_addr *target; /* new first hop to destination */
1431 struct neighbour *neigh;
1432 int on_link = 0;
1433 struct ndisc_options ndopts;
1434 int optlen;
1435 u8 *lladdr = NULL;
1436
1437 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1438 switch (skb->ndisc_nodetype) {
1439 case NDISC_NODETYPE_HOST:
1440 case NDISC_NODETYPE_NODEFAULT:
1441 ND_PRINTK2(KERN_WARNING
1442 "ICMPv6 Redirect: from host or unauthorized router\n");
1443 return;
1444 }
1445 #endif
1446
1447 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1448 ND_PRINTK2(KERN_WARNING
1449 "ICMPv6 Redirect: source address is not link-local.\n");
1450 return;
1451 }
1452
1453 optlen = skb->tail - skb->transport_header;
1454 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1455
1456 if (optlen < 0) {
1457 ND_PRINTK2(KERN_WARNING
1458 "ICMPv6 Redirect: packet too short\n");
1459 return;
1460 }
1461
1462 icmph = icmp6_hdr(skb);
1463 target = (const struct in6_addr *) (icmph + 1);
1464 dest = target + 1;
1465
1466 if (ipv6_addr_is_multicast(dest)) {
1467 ND_PRINTK2(KERN_WARNING
1468 "ICMPv6 Redirect: destination address is multicast.\n");
1469 return;
1470 }
1471
1472 if (ipv6_addr_equal(dest, target)) {
1473 on_link = 1;
1474 } else if (ipv6_addr_type(target) !=
1475 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1476 ND_PRINTK2(KERN_WARNING
1477 "ICMPv6 Redirect: target address is not link-local unicast.\n");
1478 return;
1479 }
1480
1481 in6_dev = __in6_dev_get(skb->dev);
1482 if (!in6_dev)
1483 return;
1484 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
1485 return;
1486
1487 /* RFC2461 8.1:
1488 * The IP source address of the Redirect MUST be the same as the current
1489 * first-hop router for the specified ICMP Destination Address.
1490 */
1491
1492 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1493 ND_PRINTK2(KERN_WARNING
1494 "ICMPv6 Redirect: invalid ND options\n");
1495 return;
1496 }
1497 if (ndopts.nd_opts_tgt_lladdr) {
1498 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1499 skb->dev);
1500 if (!lladdr) {
1501 ND_PRINTK2(KERN_WARNING
1502 "ICMPv6 Redirect: invalid link-layer address length\n");
1503 return;
1504 }
1505 }
1506
1507 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1508 if (neigh) {
1509 rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1510 &ipv6_hdr(skb)->saddr, neigh, lladdr,
1511 on_link);
1512 neigh_release(neigh);
1513 }
1514 }
1515
1516 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1517 {
1518 struct net_device *dev = skb->dev;
1519 struct net *net = dev_net(dev);
1520 struct sock *sk = net->ipv6.ndisc_sk;
1521 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1522 struct sk_buff *buff;
1523 struct icmp6hdr *icmph;
1524 struct in6_addr saddr_buf;
1525 struct in6_addr *addrp;
1526 struct rt6_info *rt;
1527 struct dst_entry *dst;
1528 struct inet6_dev *idev;
1529 struct flowi6 fl6;
1530 u8 *opt;
1531 int hlen, tlen;
1532 int rd_len;
1533 int err;
1534 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1535
1536 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1537 ND_PRINTK2(KERN_WARNING
1538 "ICMPv6 Redirect: no link-local address on %s\n",
1539 dev->name);
1540 return;
1541 }
1542
1543 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1544 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1545 ND_PRINTK2(KERN_WARNING
1546 "ICMPv6 Redirect: target address is not link-local unicast.\n");
1547 return;
1548 }
1549
1550 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1551 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1552
1553 dst = ip6_route_output(net, NULL, &fl6);
1554 if (dst->error) {
1555 dst_release(dst);
1556 return;
1557 }
1558 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1559 if (IS_ERR(dst))
1560 return;
1561
1562 rt = (struct rt6_info *) dst;
1563
1564 if (rt->rt6i_flags & RTF_GATEWAY) {
1565 ND_PRINTK2(KERN_WARNING
1566 "ICMPv6 Redirect: destination is not a neighbour.\n");
1567 goto release;
1568 }
1569 if (!rt->rt6i_peer)
1570 rt6_bind_peer(rt, 1);
1571 if (!inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
1572 goto release;
1573
1574 if (dev->addr_len) {
1575 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1576 if (!neigh) {
1577 ND_PRINTK2(KERN_WARNING
1578 "ICMPv6 Redirect: no neigh for target address\n");
1579 goto release;
1580 }
1581
1582 read_lock_bh(&neigh->lock);
1583 if (neigh->nud_state & NUD_VALID) {
1584 memcpy(ha_buf, neigh->ha, dev->addr_len);
1585 read_unlock_bh(&neigh->lock);
1586 ha = ha_buf;
1587 len += ndisc_opt_addr_space(dev);
1588 } else
1589 read_unlock_bh(&neigh->lock);
1590
1591 neigh_release(neigh);
1592 }
1593
1594 rd_len = min_t(unsigned int,
1595 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1596 rd_len &= ~0x7;
1597 len += rd_len;
1598
1599 hlen = LL_RESERVED_SPACE(dev);
1600 tlen = dev->needed_tailroom;
1601 buff = sock_alloc_send_skb(sk,
1602 (MAX_HEADER + sizeof(struct ipv6hdr) +
1603 len + hlen + tlen),
1604 1, &err);
1605 if (buff == NULL) {
1606 ND_PRINTK0(KERN_ERR
1607 "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1608 __func__, err);
1609 goto release;
1610 }
1611
1612 skb_reserve(buff, hlen);
1613 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1614 IPPROTO_ICMPV6, len);
1615
1616 skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1617 skb_put(buff, len);
1618 icmph = icmp6_hdr(buff);
1619
1620 memset(icmph, 0, sizeof(struct icmp6hdr));
1621 icmph->icmp6_type = NDISC_REDIRECT;
1622
1623 /*
1624 * copy target and destination addresses
1625 */
1626
1627 addrp = (struct in6_addr *)(icmph + 1);
1628 *addrp = *target;
1629 addrp++;
1630 *addrp = ipv6_hdr(skb)->daddr;
1631
1632 opt = (u8*) (addrp + 1);
1633
1634 /*
1635 * include target_address option
1636 */
1637
1638 if (ha)
1639 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1640 dev->addr_len, dev->type);
1641
1642 /*
1643 * build redirect option and copy skb over to the new packet.
1644 */
1645
1646 memset(opt, 0, 8);
1647 *(opt++) = ND_OPT_REDIRECT_HDR;
1648 *(opt++) = (rd_len >> 3);
1649 opt += 6;
1650
1651 memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1652
1653 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1654 len, IPPROTO_ICMPV6,
1655 csum_partial(icmph, len, 0));
1656
1657 skb_dst_set(buff, dst);
1658 rcu_read_lock();
1659 idev = __in6_dev_get(dst->dev);
1660 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1661 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1662 dst_output);
1663 if (!err) {
1664 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1665 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1666 }
1667
1668 rcu_read_unlock();
1669 return;
1670
1671 release:
1672 dst_release(dst);
1673 }
1674
1675 static void pndisc_redo(struct sk_buff *skb)
1676 {
1677 ndisc_recv_ns(skb);
1678 kfree_skb(skb);
1679 }
1680
1681 int ndisc_rcv(struct sk_buff *skb)
1682 {
1683 struct nd_msg *msg;
1684
1685 if (!pskb_may_pull(skb, skb->len))
1686 return 0;
1687
1688 msg = (struct nd_msg *)skb_transport_header(skb);
1689
1690 __skb_push(skb, skb->data - skb_transport_header(skb));
1691
1692 if (ipv6_hdr(skb)->hop_limit != 255) {
1693 ND_PRINTK2(KERN_WARNING
1694 "ICMPv6 NDISC: invalid hop-limit: %d\n",
1695 ipv6_hdr(skb)->hop_limit);
1696 return 0;
1697 }
1698
1699 if (msg->icmph.icmp6_code != 0) {
1700 ND_PRINTK2(KERN_WARNING
1701 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1702 msg->icmph.icmp6_code);
1703 return 0;
1704 }
1705
1706 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1707
1708 switch (msg->icmph.icmp6_type) {
1709 case NDISC_NEIGHBOUR_SOLICITATION:
1710 ndisc_recv_ns(skb);
1711 break;
1712
1713 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1714 ndisc_recv_na(skb);
1715 break;
1716
1717 case NDISC_ROUTER_SOLICITATION:
1718 ndisc_recv_rs(skb);
1719 break;
1720
1721 case NDISC_ROUTER_ADVERTISEMENT:
1722 ndisc_router_discovery(skb);
1723 break;
1724
1725 case NDISC_REDIRECT:
1726 ndisc_redirect_rcv(skb);
1727 break;
1728 }
1729
1730 return 0;
1731 }
1732
1733 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1734 {
1735 struct net_device *dev = ptr;
1736 struct net *net = dev_net(dev);
1737
1738 switch (event) {
1739 case NETDEV_CHANGEADDR:
1740 neigh_changeaddr(&nd_tbl, dev);
1741 fib6_run_gc(~0UL, net);
1742 break;
1743 case NETDEV_DOWN:
1744 neigh_ifdown(&nd_tbl, dev);
1745 fib6_run_gc(~0UL, net);
1746 break;
1747 case NETDEV_NOTIFY_PEERS:
1748 ndisc_send_unsol_na(dev);
1749 break;
1750 default:
1751 break;
1752 }
1753
1754 return NOTIFY_DONE;
1755 }
1756
1757 static struct notifier_block ndisc_netdev_notifier = {
1758 .notifier_call = ndisc_netdev_event,
1759 };
1760
1761 #ifdef CONFIG_SYSCTL
1762 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1763 const char *func, const char *dev_name)
1764 {
1765 static char warncomm[TASK_COMM_LEN];
1766 static int warned;
1767 if (strcmp(warncomm, current->comm) && warned < 5) {
1768 strcpy(warncomm, current->comm);
1769 printk(KERN_WARNING
1770 "process `%s' is using deprecated sysctl (%s) "
1771 "net.ipv6.neigh.%s.%s; "
1772 "Use net.ipv6.neigh.%s.%s_ms "
1773 "instead.\n",
1774 warncomm, func,
1775 dev_name, ctl->procname,
1776 dev_name, ctl->procname);
1777 warned++;
1778 }
1779 }
1780
1781 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
1782 {
1783 struct net_device *dev = ctl->extra1;
1784 struct inet6_dev *idev;
1785 int ret;
1786
1787 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1788 (strcmp(ctl->procname, "base_reachable_time") == 0))
1789 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1790
1791 if (strcmp(ctl->procname, "retrans_time") == 0)
1792 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1793
1794 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1795 ret = proc_dointvec_jiffies(ctl, write,
1796 buffer, lenp, ppos);
1797
1798 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1799 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1800 ret = proc_dointvec_ms_jiffies(ctl, write,
1801 buffer, lenp, ppos);
1802 else
1803 ret = -1;
1804
1805 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1806 if (ctl->data == &idev->nd_parms->base_reachable_time)
1807 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1808 idev->tstamp = jiffies;
1809 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1810 in6_dev_put(idev);
1811 }
1812 return ret;
1813 }
1814
1815
1816 #endif
1817
1818 static int __net_init ndisc_net_init(struct net *net)
1819 {
1820 struct ipv6_pinfo *np;
1821 struct sock *sk;
1822 int err;
1823
1824 err = inet_ctl_sock_create(&sk, PF_INET6,
1825 SOCK_RAW, IPPROTO_ICMPV6, net);
1826 if (err < 0) {
1827 ND_PRINTK0(KERN_ERR
1828 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1829 err);
1830 return err;
1831 }
1832
1833 net->ipv6.ndisc_sk = sk;
1834
1835 np = inet6_sk(sk);
1836 np->hop_limit = 255;
1837 /* Do not loopback ndisc messages */
1838 np->mc_loop = 0;
1839
1840 return 0;
1841 }
1842
1843 static void __net_exit ndisc_net_exit(struct net *net)
1844 {
1845 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1846 }
1847
1848 static struct pernet_operations ndisc_net_ops = {
1849 .init = ndisc_net_init,
1850 .exit = ndisc_net_exit,
1851 };
1852
1853 int __init ndisc_init(void)
1854 {
1855 int err;
1856
1857 err = register_pernet_subsys(&ndisc_net_ops);
1858 if (err)
1859 return err;
1860 /*
1861 * Initialize the neighbour table
1862 */
1863 neigh_table_init(&nd_tbl);
1864
1865 #ifdef CONFIG_SYSCTL
1866 err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6",
1867 &ndisc_ifinfo_sysctl_change);
1868 if (err)
1869 goto out_unregister_pernet;
1870 #endif
1871 err = register_netdevice_notifier(&ndisc_netdev_notifier);
1872 if (err)
1873 goto out_unregister_sysctl;
1874 out:
1875 return err;
1876
1877 out_unregister_sysctl:
1878 #ifdef CONFIG_SYSCTL
1879 neigh_sysctl_unregister(&nd_tbl.parms);
1880 out_unregister_pernet:
1881 #endif
1882 unregister_pernet_subsys(&ndisc_net_ops);
1883 goto out;
1884 }
1885
1886 void ndisc_cleanup(void)
1887 {
1888 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1889 #ifdef CONFIG_SYSCTL
1890 neigh_sysctl_unregister(&nd_tbl.parms);
1891 #endif
1892 neigh_table_clear(&nd_tbl);
1893 unregister_pernet_subsys(&ndisc_net_ops);
1894 }
Linux kernel - Deliverables
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