projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
[IPV6] NDISC: Avoid updating neighbor cache for proxied address in receiving NA.
[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 * Lars Fenneberg : fixed MTU setting on receipt
19 * of an RA.
20 *
21 * Janos Farkas : kmalloc failure checks
22 * Alexey Kuznetsov : state machine reworked
23 * and moved to net/core.
24 * Pekka Savola : RFC2461 validation
25 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
26 */
27
28 /* Set to 3 to get tracing... */
29 #define ND_DEBUG 1
30
31 #define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
32 #define ND_NOPRINTK(x...) do { ; } while(0)
33 #define ND_PRINTK0 ND_PRINTK
34 #define ND_PRINTK1 ND_NOPRINTK
35 #define ND_PRINTK2 ND_NOPRINTK
36 #define ND_PRINTK3 ND_NOPRINTK
37 #if ND_DEBUG >= 1
38 #undef ND_PRINTK1
39 #define ND_PRINTK1 ND_PRINTK
40 #endif
41 #if ND_DEBUG >= 2
42 #undef ND_PRINTK2
43 #define ND_PRINTK2 ND_PRINTK
44 #endif
45 #if ND_DEBUG >= 3
46 #undef ND_PRINTK3
47 #define ND_PRINTK3 ND_PRINTK
48 #endif
49
50 #include <linux/module.h>
51 #include <linux/errno.h>
52 #include <linux/types.h>
53 #include <linux/socket.h>
54 #include <linux/sockios.h>
55 #include <linux/sched.h>
56 #include <linux/net.h>
57 #include <linux/in6.h>
58 #include <linux/route.h>
59 #include <linux/init.h>
60 #include <linux/rcupdate.h>
61 #ifdef CONFIG_SYSCTL
62 #include <linux/sysctl.h>
63 #endif
64
65 #include <linux/if_addr.h>
66 #include <linux/if_arp.h>
67 #include <linux/ipv6.h>
68 #include <linux/icmpv6.h>
69 #include <linux/jhash.h>
70
71 #include <net/sock.h>
72 #include <net/snmp.h>
73
74 #include <net/ipv6.h>
75 #include <net/protocol.h>
76 #include <net/ndisc.h>
77 #include <net/ip6_route.h>
78 #include <net/addrconf.h>
79 #include <net/icmp.h>
80
81 #include <net/flow.h>
82 #include <net/ip6_checksum.h>
83 #include <linux/proc_fs.h>
84
85 #include <linux/netfilter.h>
86 #include <linux/netfilter_ipv6.h>
87
88 static struct socket *ndisc_socket;
89
90 static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
91 static int ndisc_constructor(struct neighbour *neigh);
92 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
93 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
94 static int pndisc_constructor(struct pneigh_entry *n);
95 static void pndisc_destructor(struct pneigh_entry *n);
96 static void pndisc_redo(struct sk_buff *skb);
97
98 static struct neigh_ops ndisc_generic_ops = {
99 .family = AF_INET6,
100 .solicit = ndisc_solicit,
101 .error_report = ndisc_error_report,
102 .output = neigh_resolve_output,
103 .connected_output = neigh_connected_output,
104 .hh_output = dev_queue_xmit,
105 .queue_xmit = dev_queue_xmit,
106 };
107
108 static struct neigh_ops ndisc_hh_ops = {
109 .family = AF_INET6,
110 .solicit = ndisc_solicit,
111 .error_report = ndisc_error_report,
112 .output = neigh_resolve_output,
113 .connected_output = neigh_resolve_output,
114 .hh_output = dev_queue_xmit,
115 .queue_xmit = dev_queue_xmit,
116 };
117
118
119 static struct neigh_ops ndisc_direct_ops = {
120 .family = AF_INET6,
121 .output = dev_queue_xmit,
122 .connected_output = dev_queue_xmit,
123 .hh_output = dev_queue_xmit,
124 .queue_xmit = dev_queue_xmit,
125 };
126
127 struct neigh_table nd_tbl = {
128 .family = AF_INET6,
129 .entry_size = sizeof(struct neighbour) + sizeof(struct in6_addr),
130 .key_len = sizeof(struct in6_addr),
131 .hash = ndisc_hash,
132 .constructor = ndisc_constructor,
133 .pconstructor = pndisc_constructor,
134 .pdestructor = pndisc_destructor,
135 .proxy_redo = pndisc_redo,
136 .id = "ndisc_cache",
137 .parms = {
138 .tbl = &nd_tbl,
139 .base_reachable_time = 30 * HZ,
140 .retrans_time = 1 * HZ,
141 .gc_staletime = 60 * HZ,
142 .reachable_time = 30 * HZ,
143 .delay_probe_time = 5 * HZ,
144 .queue_len = 3,
145 .ucast_probes = 3,
146 .mcast_probes = 3,
147 .anycast_delay = 1 * HZ,
148 .proxy_delay = (8 * HZ) / 10,
149 .proxy_qlen = 64,
150 },
151 .gc_interval = 30 * HZ,
152 .gc_thresh1 = 128,
153 .gc_thresh2 = 512,
154 .gc_thresh3 = 1024,
155 };
156
157 /* ND options */
158 struct ndisc_options {
159 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
160 #ifdef CONFIG_IPV6_ROUTE_INFO
161 struct nd_opt_hdr *nd_opts_ri;
162 struct nd_opt_hdr *nd_opts_ri_end;
163 #endif
164 };
165
166 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
167 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR]
168 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO]
169 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
170 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
171 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
172
173 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
174
175 /*
176 * Return the padding between the option length and the start of the
177 * link addr. Currently only IP-over-InfiniBand needs this, although
178 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
179 * also need a pad of 2.
180 */
181 static int ndisc_addr_option_pad(unsigned short type)
182 {
183 switch (type) {
184 case ARPHRD_INFINIBAND: return 2;
185 default: return 0;
186 }
187 }
188
189 static inline int ndisc_opt_addr_space(struct net_device *dev)
190 {
191 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
192 }
193
194 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
195 unsigned short addr_type)
196 {
197 int space = NDISC_OPT_SPACE(data_len);
198 int pad = ndisc_addr_option_pad(addr_type);
199
200 opt[0] = type;
201 opt[1] = space>>3;
202
203 memset(opt + 2, 0, pad);
204 opt += pad;
205 space -= pad;
206
207 memcpy(opt+2, data, data_len);
208 data_len += 2;
209 opt += data_len;
210 if ((space -= data_len) > 0)
211 memset(opt, 0, space);
212 return opt + space;
213 }
214
215 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
216 struct nd_opt_hdr *end)
217 {
218 int type;
219 if (!cur || !end || cur >= end)
220 return NULL;
221 type = cur->nd_opt_type;
222 do {
223 cur = ((void *)cur) + (cur->nd_opt_len << 3);
224 } while(cur < end && cur->nd_opt_type != type);
225 return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
226 }
227
228 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
229 struct ndisc_options *ndopts)
230 {
231 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
232
233 if (!nd_opt || opt_len < 0 || !ndopts)
234 return NULL;
235 memset(ndopts, 0, sizeof(*ndopts));
236 while (opt_len) {
237 int l;
238 if (opt_len < sizeof(struct nd_opt_hdr))
239 return NULL;
240 l = nd_opt->nd_opt_len << 3;
241 if (opt_len < l || l == 0)
242 return NULL;
243 switch (nd_opt->nd_opt_type) {
244 case ND_OPT_SOURCE_LL_ADDR:
245 case ND_OPT_TARGET_LL_ADDR:
246 case ND_OPT_MTU:
247 case ND_OPT_REDIRECT_HDR:
248 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
249 ND_PRINTK2(KERN_WARNING
250 "%s(): duplicated ND6 option found: type=%d\n",
251 __FUNCTION__,
252 nd_opt->nd_opt_type);
253 } else {
254 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
255 }
256 break;
257 case ND_OPT_PREFIX_INFO:
258 ndopts->nd_opts_pi_end = nd_opt;
259 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0)
260 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
261 break;
262 #ifdef CONFIG_IPV6_ROUTE_INFO
263 case ND_OPT_ROUTE_INFO:
264 ndopts->nd_opts_ri_end = nd_opt;
265 if (!ndopts->nd_opts_ri)
266 ndopts->nd_opts_ri = nd_opt;
267 break;
268 #endif
269 default:
270 /*
271 * Unknown options must be silently ignored,
272 * to accommodate future extension to the protocol.
273 */
274 ND_PRINTK2(KERN_NOTICE
275 "%s(): ignored unsupported option; type=%d, len=%d\n",
276 __FUNCTION__,
277 nd_opt->nd_opt_type, nd_opt->nd_opt_len);
278 }
279 opt_len -= l;
280 nd_opt = ((void *)nd_opt) + l;
281 }
282 return ndopts;
283 }
284
285 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
286 struct net_device *dev)
287 {
288 u8 *lladdr = (u8 *)(p + 1);
289 int lladdrlen = p->nd_opt_len << 3;
290 int prepad = ndisc_addr_option_pad(dev->type);
291 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
292 return NULL;
293 return (lladdr + prepad);
294 }
295
296 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
297 {
298 switch (dev->type) {
299 case ARPHRD_ETHER:
300 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
301 case ARPHRD_FDDI:
302 ipv6_eth_mc_map(addr, buf);
303 return 0;
304 case ARPHRD_IEEE802_TR:
305 ipv6_tr_mc_map(addr,buf);
306 return 0;
307 case ARPHRD_ARCNET:
308 ipv6_arcnet_mc_map(addr, buf);
309 return 0;
310 case ARPHRD_INFINIBAND:
311 ipv6_ib_mc_map(addr, buf);
312 return 0;
313 default:
314 if (dir) {
315 memcpy(buf, dev->broadcast, dev->addr_len);
316 return 0;
317 }
318 }
319 return -EINVAL;
320 }
321
322 static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
323 {
324 const u32 *p32 = pkey;
325 u32 addr_hash, i;
326
327 addr_hash = 0;
328 for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
329 addr_hash ^= *p32++;
330
331 return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
332 }
333
334 static int ndisc_constructor(struct neighbour *neigh)
335 {
336 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
337 struct net_device *dev = neigh->dev;
338 struct inet6_dev *in6_dev;
339 struct neigh_parms *parms;
340 int is_multicast = ipv6_addr_is_multicast(addr);
341
342 rcu_read_lock();
343 in6_dev = in6_dev_get(dev);
344 if (in6_dev == NULL) {
345 rcu_read_unlock();
346 return -EINVAL;
347 }
348
349 parms = in6_dev->nd_parms;
350 __neigh_parms_put(neigh->parms);
351 neigh->parms = neigh_parms_clone(parms);
352 rcu_read_unlock();
353
354 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
355 if (dev->hard_header == NULL) {
356 neigh->nud_state = NUD_NOARP;
357 neigh->ops = &ndisc_direct_ops;
358 neigh->output = neigh->ops->queue_xmit;
359 } else {
360 if (is_multicast) {
361 neigh->nud_state = NUD_NOARP;
362 ndisc_mc_map(addr, neigh->ha, dev, 1);
363 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
364 neigh->nud_state = NUD_NOARP;
365 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
366 if (dev->flags&IFF_LOOPBACK)
367 neigh->type = RTN_LOCAL;
368 } else if (dev->flags&IFF_POINTOPOINT) {
369 neigh->nud_state = NUD_NOARP;
370 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
371 }
372 if (dev->hard_header_cache)
373 neigh->ops = &ndisc_hh_ops;
374 else
375 neigh->ops = &ndisc_generic_ops;
376 if (neigh->nud_state&NUD_VALID)
377 neigh->output = neigh->ops->connected_output;
378 else
379 neigh->output = neigh->ops->output;
380 }
381 in6_dev_put(in6_dev);
382 return 0;
383 }
384
385 static int pndisc_constructor(struct pneigh_entry *n)
386 {
387 struct in6_addr *addr = (struct in6_addr*)&n->key;
388 struct in6_addr maddr;
389 struct net_device *dev = n->dev;
390
391 if (dev == NULL || __in6_dev_get(dev) == NULL)
392 return -EINVAL;
393 addrconf_addr_solict_mult(addr, &maddr);
394 ipv6_dev_mc_inc(dev, &maddr);
395 return 0;
396 }
397
398 static void pndisc_destructor(struct pneigh_entry *n)
399 {
400 struct in6_addr *addr = (struct in6_addr*)&n->key;
401 struct in6_addr maddr;
402 struct net_device *dev = n->dev;
403
404 if (dev == NULL || __in6_dev_get(dev) == NULL)
405 return;
406 addrconf_addr_solict_mult(addr, &maddr);
407 ipv6_dev_mc_dec(dev, &maddr);
408 }
409
410 /*
411 * Send a Neighbour Advertisement
412 */
413
414 static inline void ndisc_flow_init(struct flowi *fl, u8 type,
415 struct in6_addr *saddr, struct in6_addr *daddr,
416 int oif)
417 {
418 memset(fl, 0, sizeof(*fl));
419 ipv6_addr_copy(&fl->fl6_src, saddr);
420 ipv6_addr_copy(&fl->fl6_dst, daddr);
421 fl->proto = IPPROTO_ICMPV6;
422 fl->fl_icmp_type = type;
423 fl->fl_icmp_code = 0;
424 fl->oif = oif;
425 security_sk_classify_flow(ndisc_socket->sk, fl);
426 }
427
428 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
429 struct in6_addr *daddr, struct in6_addr *solicited_addr,
430 int router, int solicited, int override, int inc_opt)
431 {
432 struct in6_addr tmpaddr;
433 struct inet6_ifaddr *ifp;
434 struct inet6_dev *idev;
435 struct flowi fl;
436 struct dst_entry* dst;
437 struct sock *sk = ndisc_socket->sk;
438 struct in6_addr *src_addr;
439 struct nd_msg *msg;
440 int len;
441 struct sk_buff *skb;
442 int err;
443
444 len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
445
446 /* for anycast or proxy, solicited_addr != src_addr */
447 ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
448 if (ifp) {
449 src_addr = solicited_addr;
450 in6_ifa_put(ifp);
451 } else {
452 if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
453 return;
454 src_addr = &tmpaddr;
455 }
456
457 ndisc_flow_init(&fl, NDISC_NEIGHBOUR_ADVERTISEMENT, src_addr, daddr,
458 dev->ifindex);
459
460 dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
461 if (!dst)
462 return;
463
464 err = xfrm_lookup(&dst, &fl, NULL, 0);
465 if (err < 0)
466 return;
467
468 if (inc_opt) {
469 if (dev->addr_len)
470 len += ndisc_opt_addr_space(dev);
471 else
472 inc_opt = 0;
473 }
474
475 skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
476 1, &err);
477
478 if (skb == NULL) {
479 ND_PRINTK0(KERN_ERR
480 "ICMPv6 NA: %s() failed to allocate an skb.\n",
481 __FUNCTION__);
482 dst_release(dst);
483 return;
484 }
485
486 skb_reserve(skb, LL_RESERVED_SPACE(dev));
487 ip6_nd_hdr(sk, skb, dev, src_addr, daddr, IPPROTO_ICMPV6, len);
488
489 msg = (struct nd_msg *)skb_put(skb, len);
490 skb->h.raw = (unsigned char*)msg;
491
492 msg->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
493 msg->icmph.icmp6_code = 0;
494 msg->icmph.icmp6_cksum = 0;
495
496 msg->icmph.icmp6_unused = 0;
497 msg->icmph.icmp6_router = router;
498 msg->icmph.icmp6_solicited = solicited;
499 msg->icmph.icmp6_override = !!override;
500
501 /* Set the target address. */
502 ipv6_addr_copy(&msg->target, solicited_addr);
503
504 if (inc_opt)
505 ndisc_fill_addr_option(msg->opt, ND_OPT_TARGET_LL_ADDR, dev->dev_addr,
506 dev->addr_len, dev->type);
507
508 /* checksum */
509 msg->icmph.icmp6_cksum = csum_ipv6_magic(src_addr, daddr, len,
510 IPPROTO_ICMPV6,
511 csum_partial((__u8 *) msg,
512 len, 0));
513
514 skb->dst = dst;
515 idev = in6_dev_get(dst->dev);
516 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
517 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
518 if (!err) {
519 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORADVERTISEMENTS);
520 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
521 }
522
523 if (likely(idev != NULL))
524 in6_dev_put(idev);
525 }
526
527 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
528 struct in6_addr *solicit,
529 struct in6_addr *daddr, struct in6_addr *saddr)
530 {
531 struct flowi fl;
532 struct dst_entry* dst;
533 struct inet6_dev *idev;
534 struct sock *sk = ndisc_socket->sk;
535 struct sk_buff *skb;
536 struct nd_msg *msg;
537 struct in6_addr addr_buf;
538 int len;
539 int err;
540 int send_llinfo;
541
542 if (saddr == NULL) {
543 if (ipv6_get_lladdr(dev, &addr_buf))
544 return;
545 saddr = &addr_buf;
546 }
547
548 ndisc_flow_init(&fl, NDISC_NEIGHBOUR_SOLICITATION, saddr, daddr,
549 dev->ifindex);
550
551 dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
552 if (!dst)
553 return;
554
555 err = xfrm_lookup(&dst, &fl, NULL, 0);
556 if (err < 0)
557 return;
558
559 len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
560 send_llinfo = dev->addr_len && !ipv6_addr_any(saddr);
561 if (send_llinfo)
562 len += ndisc_opt_addr_space(dev);
563
564 skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
565 1, &err);
566 if (skb == NULL) {
567 ND_PRINTK0(KERN_ERR
568 "ICMPv6 NA: %s() failed to allocate an skb.\n",
569 __FUNCTION__);
570 dst_release(dst);
571 return;
572 }
573
574 skb_reserve(skb, LL_RESERVED_SPACE(dev));
575 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
576
577 msg = (struct nd_msg *)skb_put(skb, len);
578 skb->h.raw = (unsigned char*)msg;
579 msg->icmph.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION;
580 msg->icmph.icmp6_code = 0;
581 msg->icmph.icmp6_cksum = 0;
582 msg->icmph.icmp6_unused = 0;
583
584 /* Set the target address. */
585 ipv6_addr_copy(&msg->target, solicit);
586
587 if (send_llinfo)
588 ndisc_fill_addr_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
589 dev->addr_len, dev->type);
590
591 /* checksum */
592 msg->icmph.icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr,
593 daddr, len,
594 IPPROTO_ICMPV6,
595 csum_partial((__u8 *) msg,
596 len, 0));
597 /* send it! */
598 skb->dst = dst;
599 idev = in6_dev_get(dst->dev);
600 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
601 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
602 if (!err) {
603 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORSOLICITS);
604 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
605 }
606
607 if (likely(idev != NULL))
608 in6_dev_put(idev);
609 }
610
611 void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
612 struct in6_addr *daddr)
613 {
614 struct flowi fl;
615 struct dst_entry* dst;
616 struct inet6_dev *idev;
617 struct sock *sk = ndisc_socket->sk;
618 struct sk_buff *skb;
619 struct icmp6hdr *hdr;
620 __u8 * opt;
621 int len;
622 int err;
623
624 ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
625 dev->ifindex);
626
627 dst = ndisc_dst_alloc(dev, NULL, daddr, ip6_output);
628 if (!dst)
629 return;
630
631 err = xfrm_lookup(&dst, &fl, NULL, 0);
632 if (err < 0)
633 return;
634
635 len = sizeof(struct icmp6hdr);
636 if (dev->addr_len)
637 len += ndisc_opt_addr_space(dev);
638
639 skb = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
640 1, &err);
641 if (skb == NULL) {
642 ND_PRINTK0(KERN_ERR
643 "ICMPv6 RS: %s() failed to allocate an skb.\n",
644 __FUNCTION__);
645 dst_release(dst);
646 return;
647 }
648
649 skb_reserve(skb, LL_RESERVED_SPACE(dev));
650 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
651
652 hdr = (struct icmp6hdr *)skb_put(skb, len);
653 skb->h.raw = (unsigned char*)hdr;
654 hdr->icmp6_type = NDISC_ROUTER_SOLICITATION;
655 hdr->icmp6_code = 0;
656 hdr->icmp6_cksum = 0;
657 hdr->icmp6_unused = 0;
658
659 opt = (u8*) (hdr + 1);
660
661 if (dev->addr_len)
662 ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
663 dev->addr_len, dev->type);
664
665 /* checksum */
666 hdr->icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr, daddr, len,
667 IPPROTO_ICMPV6,
668 csum_partial((__u8 *) hdr, len, 0));
669
670 /* send it! */
671 skb->dst = dst;
672 idev = in6_dev_get(dst->dev);
673 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
674 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
675 if (!err) {
676 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTROUTERSOLICITS);
677 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
678 }
679
680 if (likely(idev != NULL))
681 in6_dev_put(idev);
682 }
683
684
685 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
686 {
687 /*
688 * "The sender MUST return an ICMP
689 * destination unreachable"
690 */
691 dst_link_failure(skb);
692 kfree_skb(skb);
693 }
694
695 /* Called with locked neigh: either read or both */
696
697 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
698 {
699 struct in6_addr *saddr = NULL;
700 struct in6_addr mcaddr;
701 struct net_device *dev = neigh->dev;
702 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
703 int probes = atomic_read(&neigh->probes);
704
705 if (skb && ipv6_chk_addr(&skb->nh.ipv6h->saddr, dev, 1))
706 saddr = &skb->nh.ipv6h->saddr;
707
708 if ((probes -= neigh->parms->ucast_probes) < 0) {
709 if (!(neigh->nud_state & NUD_VALID)) {
710 ND_PRINTK1(KERN_DEBUG
711 "%s(): trying to ucast probe in NUD_INVALID: "
712 NIP6_FMT "\n",
713 __FUNCTION__,
714 NIP6(*target));
715 }
716 ndisc_send_ns(dev, neigh, target, target, saddr);
717 } else if ((probes -= neigh->parms->app_probes) < 0) {
718 #ifdef CONFIG_ARPD
719 neigh_app_ns(neigh);
720 #endif
721 } else {
722 addrconf_addr_solict_mult(target, &mcaddr);
723 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
724 }
725 }
726
727 static void ndisc_recv_ns(struct sk_buff *skb)
728 {
729 struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
730 struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
731 struct in6_addr *daddr = &skb->nh.ipv6h->daddr;
732 u8 *lladdr = NULL;
733 u32 ndoptlen = skb->tail - 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
742 if (ipv6_addr_is_multicast(&msg->target)) {
743 ND_PRINTK2(KERN_WARNING
744 "ICMPv6 NS: multicast target address");
745 return;
746 }
747
748 /*
749 * RFC2461 7.1.1:
750 * DAD has to be destined for solicited node multicast address.
751 */
752 if (dad &&
753 !(daddr->s6_addr32[0] == htonl(0xff020000) &&
754 daddr->s6_addr32[1] == htonl(0x00000000) &&
755 daddr->s6_addr32[2] == htonl(0x00000001) &&
756 daddr->s6_addr [12] == 0xff )) {
757 ND_PRINTK2(KERN_WARNING
758 "ICMPv6 NS: bad DAD packet (wrong destination)\n");
759 return;
760 }
761
762 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
763 ND_PRINTK2(KERN_WARNING
764 "ICMPv6 NS: invalid ND options\n");
765 return;
766 }
767
768 if (ndopts.nd_opts_src_lladdr) {
769 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
770 if (!lladdr) {
771 ND_PRINTK2(KERN_WARNING
772 "ICMPv6 NS: invalid link-layer address length\n");
773 return;
774 }
775
776 /* RFC2461 7.1.1:
777 * If the IP source address is the unspecified address,
778 * there MUST NOT be source link-layer address option
779 * in the message.
780 */
781 if (dad) {
782 ND_PRINTK2(KERN_WARNING
783 "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
784 return;
785 }
786 }
787
788 inc = ipv6_addr_is_multicast(daddr);
789
790 if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
791 if (ifp->flags & IFA_F_TENTATIVE) {
792 /* Address is tentative. If the source
793 is unspecified address, it is someone
794 does DAD, otherwise we ignore solicitations
795 until DAD timer expires.
796 */
797 if (!dad)
798 goto out;
799 if (dev->type == ARPHRD_IEEE802_TR) {
800 unsigned char *sadr = skb->mac.raw;
801 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
802 sadr[9] == dev->dev_addr[1] &&
803 sadr[10] == dev->dev_addr[2] &&
804 sadr[11] == dev->dev_addr[3] &&
805 sadr[12] == dev->dev_addr[4] &&
806 sadr[13] == dev->dev_addr[5]) {
807 /* looped-back to us */
808 goto out;
809 }
810 }
811 addrconf_dad_failure(ifp);
812 return;
813 }
814
815 idev = ifp->idev;
816 } else {
817 idev = in6_dev_get(dev);
818 if (!idev) {
819 /* XXX: count this drop? */
820 return;
821 }
822
823 if (ipv6_chk_acast_addr(dev, &msg->target) ||
824 (idev->cnf.forwarding &&
825 pneigh_lookup(&nd_tbl, &msg->target, dev, 0))) {
826 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
827 skb->pkt_type != PACKET_HOST &&
828 inc != 0 &&
829 idev->nd_parms->proxy_delay != 0) {
830 /*
831 * for anycast or proxy,
832 * sender should delay its response
833 * by a random time between 0 and
834 * MAX_ANYCAST_DELAY_TIME seconds.
835 * (RFC2461) -- yoshfuji
836 */
837 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
838 if (n)
839 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
840 goto out;
841 }
842 } else
843 goto out;
844 }
845
846 if (dad) {
847 struct in6_addr maddr;
848
849 ipv6_addr_all_nodes(&maddr);
850 ndisc_send_na(dev, NULL, &maddr, &msg->target,
851 idev->cnf.forwarding, 0, (ifp != NULL), 1);
852 goto out;
853 }
854
855 if (inc)
856 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
857 else
858 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
859
860 /*
861 * update / create cache entry
862 * for the source address
863 */
864 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
865 !inc || lladdr || !dev->addr_len);
866 if (neigh)
867 neigh_update(neigh, lladdr, NUD_STALE,
868 NEIGH_UPDATE_F_WEAK_OVERRIDE|
869 NEIGH_UPDATE_F_OVERRIDE);
870 if (neigh || !dev->hard_header) {
871 ndisc_send_na(dev, neigh, saddr, &msg->target,
872 idev->cnf.forwarding,
873 1, (ifp != NULL && inc), inc);
874 if (neigh)
875 neigh_release(neigh);
876 }
877
878 out:
879 if (ifp)
880 in6_ifa_put(ifp);
881 else
882 in6_dev_put(idev);
883
884 return;
885 }
886
887 static void ndisc_recv_na(struct sk_buff *skb)
888 {
889 struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
890 struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
891 struct in6_addr *daddr = &skb->nh.ipv6h->daddr;
892 u8 *lladdr = NULL;
893 u32 ndoptlen = skb->tail - msg->opt;
894 struct ndisc_options ndopts;
895 struct net_device *dev = skb->dev;
896 struct inet6_ifaddr *ifp;
897 struct neighbour *neigh;
898
899 if (skb->len < sizeof(struct nd_msg)) {
900 ND_PRINTK2(KERN_WARNING
901 "ICMPv6 NA: packet too short\n");
902 return;
903 }
904
905 if (ipv6_addr_is_multicast(&msg->target)) {
906 ND_PRINTK2(KERN_WARNING
907 "ICMPv6 NA: target address is multicast.\n");
908 return;
909 }
910
911 if (ipv6_addr_is_multicast(daddr) &&
912 msg->icmph.icmp6_solicited) {
913 ND_PRINTK2(KERN_WARNING
914 "ICMPv6 NA: solicited NA is multicasted.\n");
915 return;
916 }
917
918 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
919 ND_PRINTK2(KERN_WARNING
920 "ICMPv6 NS: invalid ND option\n");
921 return;
922 }
923 if (ndopts.nd_opts_tgt_lladdr) {
924 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
925 if (!lladdr) {
926 ND_PRINTK2(KERN_WARNING
927 "ICMPv6 NA: invalid link-layer address length\n");
928 return;
929 }
930 }
931 if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1))) {
932 if (ifp->flags & IFA_F_TENTATIVE) {
933 addrconf_dad_failure(ifp);
934 return;
935 }
936 /* What should we make now? The advertisement
937 is invalid, but ndisc specs say nothing
938 about it. It could be misconfiguration, or
939 an smart proxy agent tries to help us :-)
940 */
941 ND_PRINTK1(KERN_WARNING
942 "ICMPv6 NA: someone advertises our address on %s!\n",
943 ifp->idev->dev->name);
944 in6_ifa_put(ifp);
945 return;
946 }
947 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
948
949 if (neigh) {
950 u8 old_flags = neigh->flags;
951
952 if (neigh->nud_state & NUD_FAILED)
953 goto out;
954
955 /*
956 * Don't update the neighbor cache entry on a proxy NA from
957 * ourselves because either the proxied node is off link or it
958 * has already sent a NA to us.
959 */
960 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
961 pneigh_lookup(&nd_tbl, &msg->target, dev, 0))
962 goto out;
963
964 neigh_update(neigh, lladdr,
965 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
966 NEIGH_UPDATE_F_WEAK_OVERRIDE|
967 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
968 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
969 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
970
971 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
972 /*
973 * Change: router to host
974 */
975 struct rt6_info *rt;
976 rt = rt6_get_dflt_router(saddr, dev);
977 if (rt)
978 ip6_del_rt(rt);
979 }
980
981 out:
982 neigh_release(neigh);
983 }
984 }
985
986 static void ndisc_recv_rs(struct sk_buff *skb)
987 {
988 struct rs_msg *rs_msg = (struct rs_msg *) skb->h.raw;
989 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
990 struct neighbour *neigh;
991 struct inet6_dev *idev;
992 struct in6_addr *saddr = &skb->nh.ipv6h->saddr;
993 struct ndisc_options ndopts;
994 u8 *lladdr = NULL;
995
996 if (skb->len < sizeof(*rs_msg))
997 return;
998
999 idev = in6_dev_get(skb->dev);
1000 if (!idev) {
1001 if (net_ratelimit())
1002 ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1003 return;
1004 }
1005
1006 /* Don't accept RS if we're not in router mode */
1007 if (!idev->cnf.forwarding)
1008 goto out;
1009
1010 /*
1011 * Don't update NCE if src = ::;
1012 * this implies that the source node has no ip address assigned yet.
1013 */
1014 if (ipv6_addr_any(saddr))
1015 goto out;
1016
1017 /* Parse ND options */
1018 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1019 if (net_ratelimit())
1020 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1021 goto out;
1022 }
1023
1024 if (ndopts.nd_opts_src_lladdr) {
1025 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1026 skb->dev);
1027 if (!lladdr)
1028 goto out;
1029 }
1030
1031 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1032 if (neigh) {
1033 neigh_update(neigh, lladdr, NUD_STALE,
1034 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1035 NEIGH_UPDATE_F_OVERRIDE|
1036 NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
1037 neigh_release(neigh);
1038 }
1039 out:
1040 in6_dev_put(idev);
1041 }
1042
1043 static void ndisc_router_discovery(struct sk_buff *skb)
1044 {
1045 struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw;
1046 struct neighbour *neigh = NULL;
1047 struct inet6_dev *in6_dev;
1048 struct rt6_info *rt = NULL;
1049 int lifetime;
1050 struct ndisc_options ndopts;
1051 int optlen;
1052 unsigned int pref = 0;
1053
1054 __u8 * opt = (__u8 *)(ra_msg + 1);
1055
1056 optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg);
1057
1058 if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1059 ND_PRINTK2(KERN_WARNING
1060 "ICMPv6 RA: source address is not link-local.\n");
1061 return;
1062 }
1063 if (optlen < 0) {
1064 ND_PRINTK2(KERN_WARNING
1065 "ICMPv6 RA: packet too short\n");
1066 return;
1067 }
1068
1069 /*
1070 * set the RA_RECV flag in the interface
1071 */
1072
1073 in6_dev = in6_dev_get(skb->dev);
1074 if (in6_dev == NULL) {
1075 ND_PRINTK0(KERN_ERR
1076 "ICMPv6 RA: can't find inet6 device for %s.\n",
1077 skb->dev->name);
1078 return;
1079 }
1080 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) {
1081 in6_dev_put(in6_dev);
1082 return;
1083 }
1084
1085 if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1086 in6_dev_put(in6_dev);
1087 ND_PRINTK2(KERN_WARNING
1088 "ICMP6 RA: invalid ND options\n");
1089 return;
1090 }
1091
1092 if (in6_dev->if_flags & IF_RS_SENT) {
1093 /*
1094 * flag that an RA was received after an RS was sent
1095 * out on this interface.
1096 */
1097 in6_dev->if_flags |= IF_RA_RCVD;
1098 }
1099
1100 /*
1101 * Remember the managed/otherconf flags from most recently
1102 * received RA message (RFC 2462) -- yoshfuji
1103 */
1104 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1105 IF_RA_OTHERCONF)) |
1106 (ra_msg->icmph.icmp6_addrconf_managed ?
1107 IF_RA_MANAGED : 0) |
1108 (ra_msg->icmph.icmp6_addrconf_other ?
1109 IF_RA_OTHERCONF : 0);
1110
1111 if (!in6_dev->cnf.accept_ra_defrtr)
1112 goto skip_defrtr;
1113
1114 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1115
1116 #ifdef CONFIG_IPV6_ROUTER_PREF
1117 pref = ra_msg->icmph.icmp6_router_pref;
1118 /* 10b is handled as if it were 00b (medium) */
1119 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1120 in6_dev->cnf.accept_ra_rtr_pref)
1121 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1122 #endif
1123
1124 rt = rt6_get_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);
1125
1126 if (rt)
1127 neigh = rt->rt6i_nexthop;
1128
1129 if (rt && lifetime == 0) {
1130 neigh_clone(neigh);
1131 ip6_del_rt(rt);
1132 rt = NULL;
1133 }
1134
1135 if (rt == NULL && lifetime) {
1136 ND_PRINTK3(KERN_DEBUG
1137 "ICMPv6 RA: adding default router.\n");
1138
1139 rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev, pref);
1140 if (rt == NULL) {
1141 ND_PRINTK0(KERN_ERR
1142 "ICMPv6 RA: %s() failed to add default route.\n",
1143 __FUNCTION__);
1144 in6_dev_put(in6_dev);
1145 return;
1146 }
1147
1148 neigh = rt->rt6i_nexthop;
1149 if (neigh == NULL) {
1150 ND_PRINTK0(KERN_ERR
1151 "ICMPv6 RA: %s() got default router without neighbour.\n",
1152 __FUNCTION__);
1153 dst_release(&rt->u.dst);
1154 in6_dev_put(in6_dev);
1155 return;
1156 }
1157 neigh->flags |= NTF_ROUTER;
1158 } else if (rt) {
1159 rt->rt6i_flags |= (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1160 }
1161
1162 if (rt)
1163 rt->rt6i_expires = jiffies + (HZ * lifetime);
1164
1165 if (ra_msg->icmph.icmp6_hop_limit) {
1166 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1167 if (rt)
1168 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
1169 }
1170
1171 skip_defrtr:
1172
1173 /*
1174 * Update Reachable Time and Retrans Timer
1175 */
1176
1177 if (in6_dev->nd_parms) {
1178 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1179
1180 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1181 rtime = (rtime*HZ)/1000;
1182 if (rtime < HZ/10)
1183 rtime = HZ/10;
1184 in6_dev->nd_parms->retrans_time = rtime;
1185 in6_dev->tstamp = jiffies;
1186 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1187 }
1188
1189 rtime = ntohl(ra_msg->reachable_time);
1190 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1191 rtime = (rtime*HZ)/1000;
1192
1193 if (rtime < HZ/10)
1194 rtime = HZ/10;
1195
1196 if (rtime != in6_dev->nd_parms->base_reachable_time) {
1197 in6_dev->nd_parms->base_reachable_time = rtime;
1198 in6_dev->nd_parms->gc_staletime = 3 * rtime;
1199 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1200 in6_dev->tstamp = jiffies;
1201 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1202 }
1203 }
1204 }
1205
1206 /*
1207 * Process options.
1208 */
1209
1210 if (!neigh)
1211 neigh = __neigh_lookup(&nd_tbl, &skb->nh.ipv6h->saddr,
1212 skb->dev, 1);
1213 if (neigh) {
1214 u8 *lladdr = NULL;
1215 if (ndopts.nd_opts_src_lladdr) {
1216 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1217 skb->dev);
1218 if (!lladdr) {
1219 ND_PRINTK2(KERN_WARNING
1220 "ICMPv6 RA: invalid link-layer address length\n");
1221 goto out;
1222 }
1223 }
1224 neigh_update(neigh, lladdr, NUD_STALE,
1225 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1226 NEIGH_UPDATE_F_OVERRIDE|
1227 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1228 NEIGH_UPDATE_F_ISROUTER);
1229 }
1230
1231 #ifdef CONFIG_IPV6_ROUTE_INFO
1232 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1233 struct nd_opt_hdr *p;
1234 for (p = ndopts.nd_opts_ri;
1235 p;
1236 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1237 if (((struct route_info *)p)->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1238 continue;
1239 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1240 &skb->nh.ipv6h->saddr);
1241 }
1242 }
1243 #endif
1244
1245 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1246 struct nd_opt_hdr *p;
1247 for (p = ndopts.nd_opts_pi;
1248 p;
1249 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1250 addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
1251 }
1252 }
1253
1254 if (ndopts.nd_opts_mtu) {
1255 u32 mtu;
1256
1257 memcpy(&mtu, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1258 mtu = ntohl(mtu);
1259
1260 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1261 ND_PRINTK2(KERN_WARNING
1262 "ICMPv6 RA: invalid mtu: %d\n",
1263 mtu);
1264 } else if (in6_dev->cnf.mtu6 != mtu) {
1265 in6_dev->cnf.mtu6 = mtu;
1266
1267 if (rt)
1268 rt->u.dst.metrics[RTAX_MTU-1] = mtu;
1269
1270 rt6_mtu_change(skb->dev, mtu);
1271 }
1272 }
1273
1274 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1275 ND_PRINTK2(KERN_WARNING
1276 "ICMPv6 RA: invalid RA options");
1277 }
1278 out:
1279 if (rt)
1280 dst_release(&rt->u.dst);
1281 else if (neigh)
1282 neigh_release(neigh);
1283 in6_dev_put(in6_dev);
1284 }
1285
1286 static void ndisc_redirect_rcv(struct sk_buff *skb)
1287 {
1288 struct inet6_dev *in6_dev;
1289 struct icmp6hdr *icmph;
1290 struct in6_addr *dest;
1291 struct in6_addr *target; /* new first hop to destination */
1292 struct neighbour *neigh;
1293 int on_link = 0;
1294 struct ndisc_options ndopts;
1295 int optlen;
1296 u8 *lladdr = NULL;
1297
1298 if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
1299 ND_PRINTK2(KERN_WARNING
1300 "ICMPv6 Redirect: source address is not link-local.\n");
1301 return;
1302 }
1303
1304 optlen = skb->tail - skb->h.raw;
1305 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1306
1307 if (optlen < 0) {
1308 ND_PRINTK2(KERN_WARNING
1309 "ICMPv6 Redirect: packet too short\n");
1310 return;
1311 }
1312
1313 icmph = (struct icmp6hdr *) skb->h.raw;
1314 target = (struct in6_addr *) (icmph + 1);
1315 dest = target + 1;
1316
1317 if (ipv6_addr_is_multicast(dest)) {
1318 ND_PRINTK2(KERN_WARNING
1319 "ICMPv6 Redirect: destination address is multicast.\n");
1320 return;
1321 }
1322
1323 if (ipv6_addr_equal(dest, target)) {
1324 on_link = 1;
1325 } else if (!(ipv6_addr_type(target) & IPV6_ADDR_LINKLOCAL)) {
1326 ND_PRINTK2(KERN_WARNING
1327 "ICMPv6 Redirect: target address is not link-local.\n");
1328 return;
1329 }
1330
1331 in6_dev = in6_dev_get(skb->dev);
1332 if (!in6_dev)
1333 return;
1334 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1335 in6_dev_put(in6_dev);
1336 return;
1337 }
1338
1339 /* RFC2461 8.1:
1340 * The IP source address of the Redirect MUST be the same as the current
1341 * first-hop router for the specified ICMP Destination Address.
1342 */
1343
1344 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1345 ND_PRINTK2(KERN_WARNING
1346 "ICMPv6 Redirect: invalid ND options\n");
1347 in6_dev_put(in6_dev);
1348 return;
1349 }
1350 if (ndopts.nd_opts_tgt_lladdr) {
1351 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1352 skb->dev);
1353 if (!lladdr) {
1354 ND_PRINTK2(KERN_WARNING
1355 "ICMPv6 Redirect: invalid link-layer address length\n");
1356 in6_dev_put(in6_dev);
1357 return;
1358 }
1359 }
1360
1361 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1362 if (neigh) {
1363 rt6_redirect(dest, &skb->nh.ipv6h->daddr,
1364 &skb->nh.ipv6h->saddr, neigh, lladdr,
1365 on_link);
1366 neigh_release(neigh);
1367 }
1368 in6_dev_put(in6_dev);
1369 }
1370
1371 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1372 struct in6_addr *target)
1373 {
1374 struct sock *sk = ndisc_socket->sk;
1375 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1376 struct sk_buff *buff;
1377 struct icmp6hdr *icmph;
1378 struct in6_addr saddr_buf;
1379 struct in6_addr *addrp;
1380 struct net_device *dev;
1381 struct rt6_info *rt;
1382 struct dst_entry *dst;
1383 struct inet6_dev *idev;
1384 struct flowi fl;
1385 u8 *opt;
1386 int rd_len;
1387 int err;
1388 int hlen;
1389 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1390
1391 dev = skb->dev;
1392
1393 if (ipv6_get_lladdr(dev, &saddr_buf)) {
1394 ND_PRINTK2(KERN_WARNING
1395 "ICMPv6 Redirect: no link-local address on %s\n",
1396 dev->name);
1397 return;
1398 }
1399
1400 ndisc_flow_init(&fl, NDISC_REDIRECT, &saddr_buf, &skb->nh.ipv6h->saddr,
1401 dev->ifindex);
1402
1403 dst = ip6_route_output(NULL, &fl);
1404 if (dst == NULL)
1405 return;
1406
1407 err = xfrm_lookup(&dst, &fl, NULL, 0);
1408 if (err)
1409 return;
1410
1411 rt = (struct rt6_info *) dst;
1412
1413 if (rt->rt6i_flags & RTF_GATEWAY) {
1414 ND_PRINTK2(KERN_WARNING
1415 "ICMPv6 Redirect: destination is not a neighbour.\n");
1416 dst_release(dst);
1417 return;
1418 }
1419 if (!xrlim_allow(dst, 1*HZ)) {
1420 dst_release(dst);
1421 return;
1422 }
1423
1424 if (dev->addr_len) {
1425 read_lock_bh(&neigh->lock);
1426 if (neigh->nud_state & NUD_VALID) {
1427 memcpy(ha_buf, neigh->ha, dev->addr_len);
1428 read_unlock_bh(&neigh->lock);
1429 ha = ha_buf;
1430 len += ndisc_opt_addr_space(dev);
1431 } else
1432 read_unlock_bh(&neigh->lock);
1433 }
1434
1435 rd_len = min_t(unsigned int,
1436 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
1437 rd_len &= ~0x7;
1438 len += rd_len;
1439
1440 buff = sock_alloc_send_skb(sk, MAX_HEADER + len + LL_RESERVED_SPACE(dev),
1441 1, &err);
1442 if (buff == NULL) {
1443 ND_PRINTK0(KERN_ERR
1444 "ICMPv6 Redirect: %s() failed to allocate an skb.\n",
1445 __FUNCTION__);
1446 dst_release(dst);
1447 return;
1448 }
1449
1450 hlen = 0;
1451
1452 skb_reserve(buff, LL_RESERVED_SPACE(dev));
1453 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &skb->nh.ipv6h->saddr,
1454 IPPROTO_ICMPV6, len);
1455
1456 icmph = (struct icmp6hdr *)skb_put(buff, len);
1457 buff->h.raw = (unsigned char*)icmph;
1458
1459 memset(icmph, 0, sizeof(struct icmp6hdr));
1460 icmph->icmp6_type = NDISC_REDIRECT;
1461
1462 /*
1463 * copy target and destination addresses
1464 */
1465
1466 addrp = (struct in6_addr *)(icmph + 1);
1467 ipv6_addr_copy(addrp, target);
1468 addrp++;
1469 ipv6_addr_copy(addrp, &skb->nh.ipv6h->daddr);
1470
1471 opt = (u8*) (addrp + 1);
1472
1473 /*
1474 * include target_address option
1475 */
1476
1477 if (ha)
1478 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1479 dev->addr_len, dev->type);
1480
1481 /*
1482 * build redirect option and copy skb over to the new packet.
1483 */
1484
1485 memset(opt, 0, 8);
1486 *(opt++) = ND_OPT_REDIRECT_HDR;
1487 *(opt++) = (rd_len >> 3);
1488 opt += 6;
1489
1490 memcpy(opt, skb->nh.ipv6h, rd_len - 8);
1491
1492 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &skb->nh.ipv6h->saddr,
1493 len, IPPROTO_ICMPV6,
1494 csum_partial((u8 *) icmph, len, 0));
1495
1496 buff->dst = dst;
1497 idev = in6_dev_get(dst->dev);
1498 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1499 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, buff, NULL, dst->dev, dst_output);
1500 if (!err) {
1501 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTREDIRECTS);
1502 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
1503 }
1504
1505 if (likely(idev != NULL))
1506 in6_dev_put(idev);
1507 }
1508
1509 static void pndisc_redo(struct sk_buff *skb)
1510 {
1511 ndisc_recv_ns(skb);
1512 kfree_skb(skb);
1513 }
1514
1515 int ndisc_rcv(struct sk_buff *skb)
1516 {
1517 struct nd_msg *msg;
1518
1519 if (!pskb_may_pull(skb, skb->len))
1520 return 0;
1521
1522 msg = (struct nd_msg *) skb->h.raw;
1523
1524 __skb_push(skb, skb->data-skb->h.raw);
1525
1526 if (skb->nh.ipv6h->hop_limit != 255) {
1527 ND_PRINTK2(KERN_WARNING
1528 "ICMPv6 NDISC: invalid hop-limit: %d\n",
1529 skb->nh.ipv6h->hop_limit);
1530 return 0;
1531 }
1532
1533 if (msg->icmph.icmp6_code != 0) {
1534 ND_PRINTK2(KERN_WARNING
1535 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1536 msg->icmph.icmp6_code);
1537 return 0;
1538 }
1539
1540 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1541
1542 switch (msg->icmph.icmp6_type) {
1543 case NDISC_NEIGHBOUR_SOLICITATION:
1544 ndisc_recv_ns(skb);
1545 break;
1546
1547 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1548 ndisc_recv_na(skb);
1549 break;
1550
1551 case NDISC_ROUTER_SOLICITATION:
1552 ndisc_recv_rs(skb);
1553 break;
1554
1555 case NDISC_ROUTER_ADVERTISEMENT:
1556 ndisc_router_discovery(skb);
1557 break;
1558
1559 case NDISC_REDIRECT:
1560 ndisc_redirect_rcv(skb);
1561 break;
1562 };
1563
1564 return 0;
1565 }
1566
1567 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1568 {
1569 struct net_device *dev = ptr;
1570
1571 switch (event) {
1572 case NETDEV_CHANGEADDR:
1573 neigh_changeaddr(&nd_tbl, dev);
1574 fib6_run_gc(~0UL);
1575 break;
1576 case NETDEV_DOWN:
1577 neigh_ifdown(&nd_tbl, dev);
1578 fib6_run_gc(~0UL);
1579 break;
1580 default:
1581 break;
1582 }
1583
1584 return NOTIFY_DONE;
1585 }
1586
1587 static struct notifier_block ndisc_netdev_notifier = {
1588 .notifier_call = ndisc_netdev_event,
1589 };
1590
1591 #ifdef CONFIG_SYSCTL
1592 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1593 const char *func, const char *dev_name)
1594 {
1595 static char warncomm[TASK_COMM_LEN];
1596 static int warned;
1597 if (strcmp(warncomm, current->comm) && warned < 5) {
1598 strcpy(warncomm, current->comm);
1599 printk(KERN_WARNING
1600 "process `%s' is using deprecated sysctl (%s) "
1601 "net.ipv6.neigh.%s.%s; "
1602 "Use net.ipv6.neigh.%s.%s_ms "
1603 "instead.\n",
1604 warncomm, func,
1605 dev_name, ctl->procname,
1606 dev_name, ctl->procname);
1607 warned++;
1608 }
1609 }
1610
1611 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos)
1612 {
1613 struct net_device *dev = ctl->extra1;
1614 struct inet6_dev *idev;
1615 int ret;
1616
1617 if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1618 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1619 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1620
1621 switch (ctl->ctl_name) {
1622 case NET_NEIGH_RETRANS_TIME:
1623 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
1624 break;
1625 case NET_NEIGH_REACHABLE_TIME:
1626 ret = proc_dointvec_jiffies(ctl, write,
1627 filp, buffer, lenp, ppos);
1628 break;
1629 case NET_NEIGH_RETRANS_TIME_MS:
1630 case NET_NEIGH_REACHABLE_TIME_MS:
1631 ret = proc_dointvec_ms_jiffies(ctl, write,
1632 filp, buffer, lenp, ppos);
1633 break;
1634 default:
1635 ret = -1;
1636 }
1637
1638 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1639 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1640 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1641 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1642 idev->tstamp = jiffies;
1643 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1644 in6_dev_put(idev);
1645 }
1646 return ret;
1647 }
1648
1649 static int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl, int __user *name,
1650 int nlen, void __user *oldval,
1651 size_t __user *oldlenp,
1652 void __user *newval, size_t newlen,
1653 void **context)
1654 {
1655 struct net_device *dev = ctl->extra1;
1656 struct inet6_dev *idev;
1657 int ret;
1658
1659 if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
1660 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
1661 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default");
1662
1663 switch (ctl->ctl_name) {
1664 case NET_NEIGH_REACHABLE_TIME:
1665 ret = sysctl_jiffies(ctl, name, nlen,
1666 oldval, oldlenp, newval, newlen,
1667 context);
1668 break;
1669 case NET_NEIGH_RETRANS_TIME_MS:
1670 case NET_NEIGH_REACHABLE_TIME_MS:
1671 ret = sysctl_ms_jiffies(ctl, name, nlen,
1672 oldval, oldlenp, newval, newlen,
1673 context);
1674 break;
1675 default:
1676 ret = 0;
1677 }
1678
1679 if (newval && newlen && ret > 0 &&
1680 dev && (idev = in6_dev_get(dev)) != NULL) {
1681 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
1682 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
1683 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
1684 idev->tstamp = jiffies;
1685 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1686 in6_dev_put(idev);
1687 }
1688
1689 return ret;
1690 }
1691
1692 #endif
1693
1694 int __init ndisc_init(struct net_proto_family *ops)
1695 {
1696 struct ipv6_pinfo *np;
1697 struct sock *sk;
1698 int err;
1699
1700 err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, &ndisc_socket);
1701 if (err < 0) {
1702 ND_PRINTK0(KERN_ERR
1703 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1704 err);
1705 ndisc_socket = NULL; /* For safety. */
1706 return err;
1707 }
1708
1709 sk = ndisc_socket->sk;
1710 np = inet6_sk(sk);
1711 sk->sk_allocation = GFP_ATOMIC;
1712 np->hop_limit = 255;
1713 /* Do not loopback ndisc messages */
1714 np->mc_loop = 0;
1715 sk->sk_prot->unhash(sk);
1716
1717 /*
1718 * Initialize the neighbour table
1719 */
1720
1721 neigh_table_init(&nd_tbl);
1722
1723 #ifdef CONFIG_SYSCTL
1724 neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH,
1725 "ipv6",
1726 &ndisc_ifinfo_sysctl_change,
1727 &ndisc_ifinfo_sysctl_strategy);
1728 #endif
1729
1730 register_netdevice_notifier(&ndisc_netdev_notifier);
1731 return 0;
1732 }
1733
1734 void ndisc_cleanup(void)
1735 {
1736 #ifdef CONFIG_SYSCTL
1737 neigh_sysctl_unregister(&nd_tbl.parms);
1738 #endif
1739 neigh_table_clear(&nd_tbl);
1740 sock_release(ndisc_socket);
1741 ndisc_socket = NULL; /* For safety. */
1742 }
Linux kernel - Deliverables
This page took 0.065572 seconds and 6 git commands to generate.