1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Neighbour Discovery for IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Mike Shaver <shaver@ingenia.com>
9 */
10
11 /*
12 * Changes:
13 *
14 * Alexey I. Froloff : RFC6106 (DNSSL) support
15 * Pierre Ynard : export userland ND options
16 * through netlink (RDNSS support)
17 * Lars Fenneberg : fixed MTU setting on receipt
18 * of an RA.
19 * Janos Farkas : kmalloc failure checks
20 * Alexey Kuznetsov : state machine reworked
21 * and moved to net/core.
22 * Pekka Savola : RFC2461 validation
23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
24 */
25
26 #define pr_fmt(fmt) "ICMPv6: " fmt
27
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/types.h>
31 #include <linux/socket.h>
32 #include <linux/sockios.h>
33 #include <linux/sched.h>
34 #include <linux/net.h>
35 #include <linux/in6.h>
36 #include <linux/route.h>
37 #include <linux/init.h>
38 #include <linux/rcupdate.h>
39 #include <linux/slab.h>
40 #ifdef CONFIG_SYSCTL
41 #include <linux/sysctl.h>
42 #endif
43
44 #include <linux/if_addr.h>
45 #include <linux/if_ether.h>
46 #include <linux/if_arp.h>
47 #include <linux/ipv6.h>
48 #include <linux/icmpv6.h>
49 #include <linux/jhash.h>
50
51 #include <net/sock.h>
52 #include <net/snmp.h>
53
54 #include <net/ipv6.h>
55 #include <net/protocol.h>
56 #include <net/ndisc.h>
57 #include <net/ip6_route.h>
58 #include <net/addrconf.h>
59 #include <net/icmp.h>
60
61 #include <net/netlink.h>
62 #include <linux/rtnetlink.h>
63
64 #include <net/flow.h>
65 #include <net/ip6_checksum.h>
66 #include <net/inet_common.h>
67 #include <linux/proc_fs.h>
68
69 #include <linux/netfilter.h>
70 #include <linux/netfilter_ipv6.h>
71
72 static u32 ndisc_hash(const void *pkey,
73 const struct net_device *dev,
74 __u32 *hash_rnd);
75 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
76 static bool ndisc_allow_add(const struct net_device *dev,
77 struct netlink_ext_ack *extack);
78 static int ndisc_constructor(struct neighbour *neigh);
79 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
80 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
81 static int pndisc_constructor(struct pneigh_entry *n);
82 static void pndisc_destructor(struct pneigh_entry *n);
83 static void pndisc_redo(struct sk_buff *skb);
84 static int ndisc_is_multicast(const void *pkey);
85
86 static const struct neigh_ops ndisc_generic_ops = {
87 .family = AF_INET6,
88 .solicit = ndisc_solicit,
89 .error_report = ndisc_error_report,
90 .output = neigh_resolve_output,
91 .connected_output = neigh_connected_output,
92 };
93
94 static const struct neigh_ops ndisc_hh_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_resolve_output,
100 };
101
102
103 static const struct neigh_ops ndisc_direct_ops = {
104 .family = AF_INET6,
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
107 };
108
109 struct neigh_table nd_tbl = {
110 .family = AF_INET6,
111 .key_len = sizeof(struct in6_addr),
112 .protocol = cpu_to_be16(ETH_P_IPV6),
113 .hash = ndisc_hash,
114 .key_eq = ndisc_key_eq,
115 .constructor = ndisc_constructor,
116 .pconstructor = pndisc_constructor,
117 .pdestructor = pndisc_destructor,
118 .proxy_redo = pndisc_redo,
119 .is_multicast = ndisc_is_multicast,
120 .allow_add = ndisc_allow_add,
121 .id = "ndisc_cache",
122 .parms = {
123 .tbl = &nd_tbl,
124 .reachable_time = ND_REACHABLE_TIME,
125 .data = {
126 [NEIGH_VAR_MCAST_PROBES] = 3,
127 [NEIGH_VAR_UCAST_PROBES] = 3,
128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
131 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
132 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
133 [NEIGH_VAR_PROXY_QLEN] = 64,
134 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
135 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
136 },
137 },
138 .gc_interval = 30 * HZ,
139 .gc_thresh1 = 128,
140 .gc_thresh2 = 512,
141 .gc_thresh3 = 1024,
142 };
143 EXPORT_SYMBOL_GPL(nd_tbl);
144
__ndisc_fill_addr_option(struct sk_buff * skb,int type,void * data,int data_len,int pad)145 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
146 int data_len, int pad)
147 {
148 int space = __ndisc_opt_addr_space(data_len, pad);
149 u8 *opt = skb_put(skb, space);
150
151 opt[0] = type;
152 opt[1] = space>>3;
153
154 memset(opt + 2, 0, pad);
155 opt += pad;
156 space -= pad;
157
158 memcpy(opt+2, data, data_len);
159 data_len += 2;
160 opt += data_len;
161 space -= data_len;
162 if (space > 0)
163 memset(opt, 0, space);
164 }
165 EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
166
ndisc_fill_addr_option(struct sk_buff * skb,int type,void * data,u8 icmp6_type)167 static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
168 void *data, u8 icmp6_type)
169 {
170 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
171 ndisc_addr_option_pad(skb->dev->type));
172 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
173 }
174
ndisc_fill_redirect_addr_option(struct sk_buff * skb,void * ha,const u8 * ops_data)175 static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
176 void *ha,
177 const u8 *ops_data)
178 {
179 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
180 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
181 }
182
ndisc_next_option(struct nd_opt_hdr * cur,struct nd_opt_hdr * end)183 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
184 struct nd_opt_hdr *end)
185 {
186 int type;
187 if (!cur || !end || cur >= end)
188 return NULL;
189 type = cur->nd_opt_type;
190 do {
191 cur = ((void *)cur) + (cur->nd_opt_len << 3);
192 } while (cur < end && cur->nd_opt_type != type);
193 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
194 }
195
ndisc_is_useropt(const struct net_device * dev,struct nd_opt_hdr * opt)196 static inline int ndisc_is_useropt(const struct net_device *dev,
197 struct nd_opt_hdr *opt)
198 {
199 return opt->nd_opt_type == ND_OPT_PREFIX_INFO ||
200 opt->nd_opt_type == ND_OPT_RDNSS ||
201 opt->nd_opt_type == ND_OPT_DNSSL ||
202 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
203 opt->nd_opt_type == ND_OPT_PREF64 ||
204 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
205 }
206
ndisc_next_useropt(const struct net_device * dev,struct nd_opt_hdr * cur,struct nd_opt_hdr * end)207 static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
208 struct nd_opt_hdr *cur,
209 struct nd_opt_hdr *end)
210 {
211 if (!cur || !end || cur >= end)
212 return NULL;
213 do {
214 cur = ((void *)cur) + (cur->nd_opt_len << 3);
215 } while (cur < end && !ndisc_is_useropt(dev, cur));
216 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
217 }
218
ndisc_parse_options(const struct net_device * dev,u8 * opt,int opt_len,struct ndisc_options * ndopts)219 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
220 u8 *opt, int opt_len,
221 struct ndisc_options *ndopts)
222 {
223 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
224
225 if (!nd_opt || opt_len < 0 || !ndopts)
226 return NULL;
227 memset(ndopts, 0, sizeof(*ndopts));
228 while (opt_len) {
229 int l;
230 if (opt_len < sizeof(struct nd_opt_hdr))
231 return NULL;
232 l = nd_opt->nd_opt_len << 3;
233 if (opt_len < l || l == 0)
234 return NULL;
235 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
236 goto next_opt;
237 switch (nd_opt->nd_opt_type) {
238 case ND_OPT_SOURCE_LL_ADDR:
239 case ND_OPT_TARGET_LL_ADDR:
240 case ND_OPT_MTU:
241 case ND_OPT_NONCE:
242 case ND_OPT_REDIRECT_HDR:
243 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
244 ND_PRINTK(2, warn,
245 "%s: duplicated ND6 option found: type=%d\n",
246 __func__, nd_opt->nd_opt_type);
247 } else {
248 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
249 }
250 break;
251 case ND_OPT_PREFIX_INFO:
252 ndopts->nd_opts_pi_end = nd_opt;
253 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
254 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
255 break;
256 #ifdef CONFIG_IPV6_ROUTE_INFO
257 case ND_OPT_ROUTE_INFO:
258 ndopts->nd_opts_ri_end = nd_opt;
259 if (!ndopts->nd_opts_ri)
260 ndopts->nd_opts_ri = nd_opt;
261 break;
262 #endif
263 default:
264 if (ndisc_is_useropt(dev, nd_opt)) {
265 ndopts->nd_useropts_end = nd_opt;
266 if (!ndopts->nd_useropts)
267 ndopts->nd_useropts = nd_opt;
268 } else {
269 /*
270 * Unknown options must be silently ignored,
271 * to accommodate future extension to the
272 * protocol.
273 */
274 ND_PRINTK(2, notice,
275 "%s: ignored unsupported option; type=%d, len=%d\n",
276 __func__,
277 nd_opt->nd_opt_type,
278 nd_opt->nd_opt_len);
279 }
280 }
281 next_opt:
282 opt_len -= l;
283 nd_opt = ((void *)nd_opt) + l;
284 }
285 return ndopts;
286 }
287
ndisc_mc_map(const struct in6_addr * addr,char * buf,struct net_device * dev,int dir)288 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
289 {
290 switch (dev->type) {
291 case ARPHRD_ETHER:
292 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
293 case ARPHRD_FDDI:
294 ipv6_eth_mc_map(addr, buf);
295 return 0;
296 case ARPHRD_ARCNET:
297 ipv6_arcnet_mc_map(addr, buf);
298 return 0;
299 case ARPHRD_INFINIBAND:
300 ipv6_ib_mc_map(addr, dev->broadcast, buf);
301 return 0;
302 case ARPHRD_IPGRE:
303 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
304 default:
305 if (dir) {
306 memcpy(buf, dev->broadcast, dev->addr_len);
307 return 0;
308 }
309 }
310 return -EINVAL;
311 }
312 EXPORT_SYMBOL(ndisc_mc_map);
313
ndisc_hash(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)314 static u32 ndisc_hash(const void *pkey,
315 const struct net_device *dev,
316 __u32 *hash_rnd)
317 {
318 return ndisc_hashfn(pkey, dev, hash_rnd);
319 }
320
ndisc_key_eq(const struct neighbour * n,const void * pkey)321 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
322 {
323 return neigh_key_eq128(n, pkey);
324 }
325
ndisc_constructor(struct neighbour * neigh)326 static int ndisc_constructor(struct neighbour *neigh)
327 {
328 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
329 struct net_device *dev = neigh->dev;
330 struct inet6_dev *in6_dev;
331 struct neigh_parms *parms;
332 bool is_multicast = ipv6_addr_is_multicast(addr);
333
334 in6_dev = in6_dev_get(dev);
335 if (!in6_dev) {
336 return -EINVAL;
337 }
338
339 parms = in6_dev->nd_parms;
340 __neigh_parms_put(neigh->parms);
341 neigh->parms = neigh_parms_clone(parms);
342
343 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
344 if (!dev->header_ops) {
345 neigh->nud_state = NUD_NOARP;
346 neigh->ops = &ndisc_direct_ops;
347 neigh->output = neigh_direct_output;
348 } else {
349 if (is_multicast) {
350 neigh->nud_state = NUD_NOARP;
351 ndisc_mc_map(addr, neigh->ha, dev, 1);
352 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
353 neigh->nud_state = NUD_NOARP;
354 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
355 if (dev->flags&IFF_LOOPBACK)
356 neigh->type = RTN_LOCAL;
357 } else if (dev->flags&IFF_POINTOPOINT) {
358 neigh->nud_state = NUD_NOARP;
359 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
360 }
361 if (dev->header_ops->cache)
362 neigh->ops = &ndisc_hh_ops;
363 else
364 neigh->ops = &ndisc_generic_ops;
365 if (neigh->nud_state&NUD_VALID)
366 neigh->output = neigh->ops->connected_output;
367 else
368 neigh->output = neigh->ops->output;
369 }
370 in6_dev_put(in6_dev);
371 return 0;
372 }
373
pndisc_constructor(struct pneigh_entry * n)374 static int pndisc_constructor(struct pneigh_entry *n)
375 {
376 struct in6_addr *addr = (struct in6_addr *)&n->key;
377 struct in6_addr maddr;
378 struct net_device *dev = n->dev;
379
380 if (!dev || !__in6_dev_get(dev))
381 return -EINVAL;
382 addrconf_addr_solict_mult(addr, &maddr);
383 ipv6_dev_mc_inc(dev, &maddr);
384 return 0;
385 }
386
pndisc_destructor(struct pneigh_entry * n)387 static void pndisc_destructor(struct pneigh_entry *n)
388 {
389 struct in6_addr *addr = (struct in6_addr *)&n->key;
390 struct in6_addr maddr;
391 struct net_device *dev = n->dev;
392
393 if (!dev || !__in6_dev_get(dev))
394 return;
395 addrconf_addr_solict_mult(addr, &maddr);
396 ipv6_dev_mc_dec(dev, &maddr);
397 }
398
399 /* called with rtnl held */
ndisc_allow_add(const struct net_device * dev,struct netlink_ext_ack * extack)400 static bool ndisc_allow_add(const struct net_device *dev,
401 struct netlink_ext_ack *extack)
402 {
403 struct inet6_dev *idev = __in6_dev_get(dev);
404
405 if (!idev || idev->cnf.disable_ipv6) {
406 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
407 return false;
408 }
409
410 return true;
411 }
412
ndisc_alloc_skb(struct net_device * dev,int len)413 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
414 int len)
415 {
416 int hlen = LL_RESERVED_SPACE(dev);
417 int tlen = dev->needed_tailroom;
418 struct sk_buff *skb;
419
420 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
421 if (!skb)
422 return NULL;
423
424 skb->protocol = htons(ETH_P_IPV6);
425 skb->dev = dev;
426
427 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
428 skb_reset_transport_header(skb);
429
430 /* Manually assign socket ownership as we avoid calling
431 * sock_alloc_send_pskb() to bypass wmem buffer limits
432 */
433 rcu_read_lock();
434 skb_set_owner_w(skb, dev_net_rcu(dev)->ipv6.ndisc_sk);
435 rcu_read_unlock();
436
437 return skb;
438 }
439
ip6_nd_hdr(struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,int hop_limit,int len)440 static void ip6_nd_hdr(struct sk_buff *skb,
441 const struct in6_addr *saddr,
442 const struct in6_addr *daddr,
443 int hop_limit, int len)
444 {
445 struct ipv6hdr *hdr;
446 struct inet6_dev *idev;
447 unsigned tclass;
448
449 rcu_read_lock();
450 idev = __in6_dev_get(skb->dev);
451 tclass = idev ? idev->cnf.ndisc_tclass : 0;
452 rcu_read_unlock();
453
454 skb_push(skb, sizeof(*hdr));
455 skb_reset_network_header(skb);
456 hdr = ipv6_hdr(skb);
457
458 ip6_flow_hdr(hdr, tclass, 0);
459
460 hdr->payload_len = htons(len);
461 hdr->nexthdr = IPPROTO_ICMPV6;
462 hdr->hop_limit = hop_limit;
463
464 hdr->saddr = *saddr;
465 hdr->daddr = *daddr;
466 }
467
ndisc_send_skb(struct sk_buff * skb,const struct in6_addr * daddr,const struct in6_addr * saddr)468 static void ndisc_send_skb(struct sk_buff *skb,
469 const struct in6_addr *daddr,
470 const struct in6_addr *saddr)
471 {
472 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
473 struct dst_entry *dst = skb_dst(skb);
474 struct inet6_dev *idev;
475 struct net *net;
476 struct sock *sk;
477 int err;
478 u8 type;
479
480 type = icmp6h->icmp6_type;
481
482 rcu_read_lock();
483
484 net = dev_net_rcu(skb->dev);
485 sk = net->ipv6.ndisc_sk;
486 if (!dst) {
487 struct flowi6 fl6;
488 int oif = skb->dev->ifindex;
489
490 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
491 dst = icmp6_dst_alloc(skb->dev, &fl6);
492 if (IS_ERR(dst)) {
493 rcu_read_unlock();
494 kfree_skb(skb);
495 return;
496 }
497
498 skb_dst_set(skb, dst);
499 }
500
501 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
502 IPPROTO_ICMPV6,
503 csum_partial(icmp6h,
504 skb->len, 0));
505
506 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
507
508 idev = __in6_dev_get(dst->dev);
509 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
510
511 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
512 net, sk, skb, NULL, dst->dev,
513 dst_output);
514 if (!err) {
515 ICMP6MSGOUT_INC_STATS(net, idev, type);
516 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
517 }
518
519 rcu_read_unlock();
520 }
521
ndisc_send_na(struct net_device * dev,const struct in6_addr * daddr,const struct in6_addr * solicited_addr,bool router,bool solicited,bool override,bool inc_opt)522 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
523 const struct in6_addr *solicited_addr,
524 bool router, bool solicited, bool override, bool inc_opt)
525 {
526 struct sk_buff *skb;
527 struct in6_addr tmpaddr;
528 struct inet6_ifaddr *ifp;
529 const struct in6_addr *src_addr;
530 struct nd_msg *msg;
531 int optlen = 0;
532
533 /* for anycast or proxy, solicited_addr != src_addr */
534 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
535 if (ifp) {
536 src_addr = solicited_addr;
537 if (ifp->flags & IFA_F_OPTIMISTIC)
538 override = false;
539 inc_opt |= ifp->idev->cnf.force_tllao;
540 in6_ifa_put(ifp);
541 } else {
542 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
543 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
544 &tmpaddr))
545 return;
546 src_addr = &tmpaddr;
547 }
548
549 if (!dev->addr_len)
550 inc_opt = false;
551 if (inc_opt)
552 optlen += ndisc_opt_addr_space(dev,
553 NDISC_NEIGHBOUR_ADVERTISEMENT);
554
555 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
556 if (!skb)
557 return;
558
559 msg = skb_put(skb, sizeof(*msg));
560 *msg = (struct nd_msg) {
561 .icmph = {
562 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
563 .icmp6_router = router,
564 .icmp6_solicited = solicited,
565 .icmp6_override = override,
566 },
567 .target = *solicited_addr,
568 };
569
570 if (inc_opt)
571 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
572 dev->dev_addr,
573 NDISC_NEIGHBOUR_ADVERTISEMENT);
574
575 ndisc_send_skb(skb, daddr, src_addr);
576 }
577
ndisc_send_unsol_na(struct net_device * dev)578 static void ndisc_send_unsol_na(struct net_device *dev)
579 {
580 struct inet6_dev *idev;
581 struct inet6_ifaddr *ifa;
582
583 idev = in6_dev_get(dev);
584 if (!idev)
585 return;
586
587 read_lock_bh(&idev->lock);
588 list_for_each_entry(ifa, &idev->addr_list, if_list) {
589 /* skip tentative addresses until dad completes */
590 if (ifa->flags & IFA_F_TENTATIVE &&
591 !(ifa->flags & IFA_F_OPTIMISTIC))
592 continue;
593
594 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
595 /*router=*/ !!idev->cnf.forwarding,
596 /*solicited=*/ false, /*override=*/ true,
597 /*inc_opt=*/ true);
598 }
599 read_unlock_bh(&idev->lock);
600
601 in6_dev_put(idev);
602 }
603
ndisc_send_ns(struct net_device * dev,const struct in6_addr * solicit,const struct in6_addr * daddr,const struct in6_addr * saddr,u64 nonce)604 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
605 const struct in6_addr *daddr, const struct in6_addr *saddr,
606 u64 nonce)
607 {
608 struct sk_buff *skb;
609 struct in6_addr addr_buf;
610 int inc_opt = dev->addr_len;
611 int optlen = 0;
612 struct nd_msg *msg;
613
614 if (!saddr) {
615 if (ipv6_get_lladdr(dev, &addr_buf,
616 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
617 return;
618 saddr = &addr_buf;
619 }
620
621 if (ipv6_addr_any(saddr))
622 inc_opt = false;
623 if (inc_opt)
624 optlen += ndisc_opt_addr_space(dev,
625 NDISC_NEIGHBOUR_SOLICITATION);
626 if (nonce != 0)
627 optlen += 8;
628
629 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
630 if (!skb)
631 return;
632
633 msg = skb_put(skb, sizeof(*msg));
634 *msg = (struct nd_msg) {
635 .icmph = {
636 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
637 },
638 .target = *solicit,
639 };
640
641 if (inc_opt)
642 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
643 dev->dev_addr,
644 NDISC_NEIGHBOUR_SOLICITATION);
645 if (nonce != 0) {
646 u8 *opt = skb_put(skb, 8);
647
648 opt[0] = ND_OPT_NONCE;
649 opt[1] = 8 >> 3;
650 memcpy(opt + 2, &nonce, 6);
651 }
652
653 ndisc_send_skb(skb, daddr, saddr);
654 }
655
ndisc_send_rs(struct net_device * dev,const struct in6_addr * saddr,const struct in6_addr * daddr)656 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
657 const struct in6_addr *daddr)
658 {
659 struct sk_buff *skb;
660 struct rs_msg *msg;
661 int send_sllao = dev->addr_len;
662 int optlen = 0;
663
664 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
665 /*
666 * According to section 2.2 of RFC 4429, we must not
667 * send router solicitations with a sllao from
668 * optimistic addresses, but we may send the solicitation
669 * if we don't include the sllao. So here we check
670 * if our address is optimistic, and if so, we
671 * suppress the inclusion of the sllao.
672 */
673 if (send_sllao) {
674 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
675 dev, 1);
676 if (ifp) {
677 if (ifp->flags & IFA_F_OPTIMISTIC) {
678 send_sllao = 0;
679 }
680 in6_ifa_put(ifp);
681 } else {
682 send_sllao = 0;
683 }
684 }
685 #endif
686 if (send_sllao)
687 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
688
689 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
690 if (!skb)
691 return;
692
693 msg = skb_put(skb, sizeof(*msg));
694 *msg = (struct rs_msg) {
695 .icmph = {
696 .icmp6_type = NDISC_ROUTER_SOLICITATION,
697 },
698 };
699
700 if (send_sllao)
701 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
702 dev->dev_addr,
703 NDISC_ROUTER_SOLICITATION);
704
705 ndisc_send_skb(skb, daddr, saddr);
706 }
707
708
ndisc_error_report(struct neighbour * neigh,struct sk_buff * skb)709 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
710 {
711 /*
712 * "The sender MUST return an ICMP
713 * destination unreachable"
714 */
715 dst_link_failure(skb);
716 kfree_skb(skb);
717 }
718
719 /* Called with locked neigh: either read or both */
720
ndisc_solicit(struct neighbour * neigh,struct sk_buff * skb)721 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
722 {
723 struct in6_addr *saddr = NULL;
724 struct in6_addr mcaddr;
725 struct net_device *dev = neigh->dev;
726 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
727 int probes = atomic_read(&neigh->probes);
728
729 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
730 dev, false, 1,
731 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
732 saddr = &ipv6_hdr(skb)->saddr;
733 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
734 if (probes < 0) {
735 if (!(neigh->nud_state & NUD_VALID)) {
736 ND_PRINTK(1, dbg,
737 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
738 __func__, target);
739 }
740 ndisc_send_ns(dev, target, target, saddr, 0);
741 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
742 neigh_app_ns(neigh);
743 } else {
744 addrconf_addr_solict_mult(target, &mcaddr);
745 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
746 }
747 }
748
pndisc_is_router(const void * pkey,struct net_device * dev)749 static int pndisc_is_router(const void *pkey,
750 struct net_device *dev)
751 {
752 struct pneigh_entry *n;
753 int ret = -1;
754
755 read_lock_bh(&nd_tbl.lock);
756 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
757 if (n)
758 ret = !!(n->flags & NTF_ROUTER);
759 read_unlock_bh(&nd_tbl.lock);
760
761 return ret;
762 }
763
ndisc_update(const struct net_device * dev,struct neighbour * neigh,const u8 * lladdr,u8 new,u32 flags,u8 icmp6_type,struct ndisc_options * ndopts)764 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
765 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
766 struct ndisc_options *ndopts)
767 {
768 neigh_update(neigh, lladdr, new, flags, 0);
769 /* report ndisc ops about neighbour update */
770 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
771 }
772
ndisc_recv_ns(struct sk_buff * skb)773 static void ndisc_recv_ns(struct sk_buff *skb)
774 {
775 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
776 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
777 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
778 u8 *lladdr = NULL;
779 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
780 offsetof(struct nd_msg, opt));
781 struct ndisc_options ndopts;
782 struct net_device *dev = skb->dev;
783 struct inet6_ifaddr *ifp;
784 struct inet6_dev *idev = NULL;
785 struct neighbour *neigh;
786 int dad = ipv6_addr_any(saddr);
787 bool inc;
788 int is_router = -1;
789 u64 nonce = 0;
790
791 if (skb->len < sizeof(struct nd_msg)) {
792 ND_PRINTK(2, warn, "NS: packet too short\n");
793 return;
794 }
795
796 if (ipv6_addr_is_multicast(&msg->target)) {
797 ND_PRINTK(2, warn, "NS: multicast target address\n");
798 return;
799 }
800
801 /*
802 * RFC2461 7.1.1:
803 * DAD has to be destined for solicited node multicast address.
804 */
805 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
806 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
807 return;
808 }
809
810 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
811 ND_PRINTK(2, warn, "NS: invalid ND options\n");
812 return;
813 }
814
815 if (ndopts.nd_opts_src_lladdr) {
816 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
817 if (!lladdr) {
818 ND_PRINTK(2, warn,
819 "NS: invalid link-layer address length\n");
820 return;
821 }
822
823 /* RFC2461 7.1.1:
824 * If the IP source address is the unspecified address,
825 * there MUST NOT be source link-layer address option
826 * in the message.
827 */
828 if (dad) {
829 ND_PRINTK(2, warn,
830 "NS: bad DAD packet (link-layer address option)\n");
831 return;
832 }
833 }
834 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
835 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
836
837 inc = ipv6_addr_is_multicast(daddr);
838
839 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
840 if (ifp) {
841 have_ifp:
842 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
843 if (dad) {
844 if (nonce != 0 && ifp->dad_nonce == nonce) {
845 u8 *np = (u8 *)&nonce;
846 /* Matching nonce if looped back */
847 ND_PRINTK(2, notice,
848 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
849 ifp->idev->dev->name,
850 &ifp->addr, np);
851 goto out;
852 }
853 /*
854 * We are colliding with another node
855 * who is doing DAD
856 * so fail our DAD process
857 */
858 addrconf_dad_failure(skb, ifp);
859 return;
860 } else {
861 /*
862 * This is not a dad solicitation.
863 * If we are an optimistic node,
864 * we should respond.
865 * Otherwise, we should ignore it.
866 */
867 if (!(ifp->flags & IFA_F_OPTIMISTIC))
868 goto out;
869 }
870 }
871
872 idev = ifp->idev;
873 } else {
874 struct net *net = dev_net(dev);
875
876 /* perhaps an address on the master device */
877 if (netif_is_l3_slave(dev)) {
878 struct net_device *mdev;
879
880 mdev = netdev_master_upper_dev_get_rcu(dev);
881 if (mdev) {
882 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
883 if (ifp)
884 goto have_ifp;
885 }
886 }
887
888 idev = in6_dev_get(dev);
889 if (!idev) {
890 /* XXX: count this drop? */
891 return;
892 }
893
894 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
895 (idev->cnf.forwarding &&
896 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
897 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
898 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
899 skb->pkt_type != PACKET_HOST &&
900 inc &&
901 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
902 /*
903 * for anycast or proxy,
904 * sender should delay its response
905 * by a random time between 0 and
906 * MAX_ANYCAST_DELAY_TIME seconds.
907 * (RFC2461) -- yoshfuji
908 */
909 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
910 if (n)
911 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
912 goto out;
913 }
914 } else
915 goto out;
916 }
917
918 if (is_router < 0)
919 is_router = idev->cnf.forwarding;
920
921 if (dad) {
922 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
923 !!is_router, false, (ifp != NULL), true);
924 goto out;
925 }
926
927 if (inc)
928 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
929 else
930 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
931
932 /*
933 * update / create cache entry
934 * for the source address
935 */
936 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
937 !inc || lladdr || !dev->addr_len);
938 if (neigh)
939 ndisc_update(dev, neigh, lladdr, NUD_STALE,
940 NEIGH_UPDATE_F_WEAK_OVERRIDE|
941 NEIGH_UPDATE_F_OVERRIDE,
942 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
943 if (neigh || !dev->header_ops) {
944 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
945 true, (ifp != NULL && inc), inc);
946 if (neigh)
947 neigh_release(neigh);
948 }
949
950 out:
951 if (ifp)
952 in6_ifa_put(ifp);
953 else
954 in6_dev_put(idev);
955 }
956
ndisc_recv_na(struct sk_buff * skb)957 static void ndisc_recv_na(struct sk_buff *skb)
958 {
959 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
960 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
961 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
962 u8 *lladdr = NULL;
963 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
964 offsetof(struct nd_msg, opt));
965 struct ndisc_options ndopts;
966 struct net_device *dev = skb->dev;
967 struct inet6_dev *idev = __in6_dev_get(dev);
968 struct inet6_ifaddr *ifp;
969 struct neighbour *neigh;
970
971 if (skb->len < sizeof(struct nd_msg)) {
972 ND_PRINTK(2, warn, "NA: packet too short\n");
973 return;
974 }
975
976 if (ipv6_addr_is_multicast(&msg->target)) {
977 ND_PRINTK(2, warn, "NA: target address is multicast\n");
978 return;
979 }
980
981 if (ipv6_addr_is_multicast(daddr) &&
982 msg->icmph.icmp6_solicited) {
983 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
984 return;
985 }
986
987 /* For some 802.11 wireless deployments (and possibly other networks),
988 * there will be a NA proxy and unsolicitd packets are attacks
989 * and thus should not be accepted.
990 */
991 if (!msg->icmph.icmp6_solicited && idev &&
992 idev->cnf.drop_unsolicited_na)
993 return;
994
995 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
996 ND_PRINTK(2, warn, "NS: invalid ND option\n");
997 return;
998 }
999 if (ndopts.nd_opts_tgt_lladdr) {
1000 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1001 if (!lladdr) {
1002 ND_PRINTK(2, warn,
1003 "NA: invalid link-layer address length\n");
1004 return;
1005 }
1006 }
1007 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1008 if (ifp) {
1009 if (skb->pkt_type != PACKET_LOOPBACK
1010 && (ifp->flags & IFA_F_TENTATIVE)) {
1011 addrconf_dad_failure(skb, ifp);
1012 return;
1013 }
1014 /* What should we make now? The advertisement
1015 is invalid, but ndisc specs say nothing
1016 about it. It could be misconfiguration, or
1017 an smart proxy agent tries to help us :-)
1018
1019 We should not print the error if NA has been
1020 received from loopback - it is just our own
1021 unsolicited advertisement.
1022 */
1023 if (skb->pkt_type != PACKET_LOOPBACK)
1024 ND_PRINTK(1, warn,
1025 "NA: %pM advertised our address %pI6c on %s!\n",
1026 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1027 in6_ifa_put(ifp);
1028 return;
1029 }
1030 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1031
1032 if (neigh) {
1033 u8 old_flags = neigh->flags;
1034 struct net *net = dev_net(dev);
1035
1036 if (neigh->nud_state & NUD_FAILED)
1037 goto out;
1038
1039 /*
1040 * Don't update the neighbor cache entry on a proxy NA from
1041 * ourselves because either the proxied node is off link or it
1042 * has already sent a NA to us.
1043 */
1044 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1045 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1046 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1047 /* XXX: idev->cnf.proxy_ndp */
1048 goto out;
1049 }
1050
1051 ndisc_update(dev, neigh, lladdr,
1052 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1053 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1054 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1055 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1056 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1057 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1058
1059 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1060 /*
1061 * Change: router to host
1062 */
1063 rt6_clean_tohost(dev_net(dev), saddr);
1064 }
1065
1066 out:
1067 neigh_release(neigh);
1068 }
1069 }
1070
ndisc_recv_rs(struct sk_buff * skb)1071 static void ndisc_recv_rs(struct sk_buff *skb)
1072 {
1073 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1074 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1075 struct neighbour *neigh;
1076 struct inet6_dev *idev;
1077 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1078 struct ndisc_options ndopts;
1079 u8 *lladdr = NULL;
1080
1081 if (skb->len < sizeof(*rs_msg))
1082 return;
1083
1084 idev = __in6_dev_get(skb->dev);
1085 if (!idev) {
1086 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1087 return;
1088 }
1089
1090 /* Don't accept RS if we're not in router mode */
1091 if (!idev->cnf.forwarding)
1092 goto out;
1093
1094 /*
1095 * Don't update NCE if src = ::;
1096 * this implies that the source node has no ip address assigned yet.
1097 */
1098 if (ipv6_addr_any(saddr))
1099 goto out;
1100
1101 /* Parse ND options */
1102 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1103 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1104 goto out;
1105 }
1106
1107 if (ndopts.nd_opts_src_lladdr) {
1108 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1109 skb->dev);
1110 if (!lladdr)
1111 goto out;
1112 }
1113
1114 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1115 if (neigh) {
1116 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1117 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1118 NEIGH_UPDATE_F_OVERRIDE|
1119 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1120 NDISC_ROUTER_SOLICITATION, &ndopts);
1121 neigh_release(neigh);
1122 }
1123 out:
1124 return;
1125 }
1126
ndisc_ra_useropt(struct sk_buff * ra,struct nd_opt_hdr * opt)1127 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1128 {
1129 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1130 struct sk_buff *skb;
1131 struct nlmsghdr *nlh;
1132 struct nduseroptmsg *ndmsg;
1133 struct net *net = dev_net(ra->dev);
1134 int err;
1135 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1136 + (opt->nd_opt_len << 3));
1137 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1138
1139 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1140 if (!skb) {
1141 err = -ENOBUFS;
1142 goto errout;
1143 }
1144
1145 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1146 if (!nlh) {
1147 goto nla_put_failure;
1148 }
1149
1150 ndmsg = nlmsg_data(nlh);
1151 ndmsg->nduseropt_family = AF_INET6;
1152 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1153 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1154 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1155 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1156
1157 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1158
1159 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1160 goto nla_put_failure;
1161 nlmsg_end(skb, nlh);
1162
1163 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1164 return;
1165
1166 nla_put_failure:
1167 nlmsg_free(skb);
1168 err = -EMSGSIZE;
1169 errout:
1170 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1171 }
1172
ndisc_router_discovery(struct sk_buff * skb)1173 static void ndisc_router_discovery(struct sk_buff *skb)
1174 {
1175 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1176 struct neighbour *neigh = NULL;
1177 struct inet6_dev *in6_dev;
1178 struct fib6_info *rt = NULL;
1179 struct net *net;
1180 int lifetime;
1181 struct ndisc_options ndopts;
1182 int optlen;
1183 unsigned int pref = 0;
1184 __u32 old_if_flags;
1185 bool send_ifinfo_notify = false;
1186
1187 __u8 *opt = (__u8 *)(ra_msg + 1);
1188
1189 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1190 sizeof(struct ra_msg);
1191
1192 ND_PRINTK(2, info,
1193 "RA: %s, dev: %s\n",
1194 __func__, skb->dev->name);
1195 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1196 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1197 return;
1198 }
1199 if (optlen < 0) {
1200 ND_PRINTK(2, warn, "RA: packet too short\n");
1201 return;
1202 }
1203
1204 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1205 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1206 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1207 return;
1208 }
1209 #endif
1210
1211 /*
1212 * set the RA_RECV flag in the interface
1213 */
1214
1215 in6_dev = __in6_dev_get(skb->dev);
1216 if (!in6_dev) {
1217 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1218 skb->dev->name);
1219 return;
1220 }
1221
1222 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1223 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1224 return;
1225 }
1226
1227 if (!ipv6_accept_ra(in6_dev)) {
1228 ND_PRINTK(2, info,
1229 "RA: %s, did not accept ra for dev: %s\n",
1230 __func__, skb->dev->name);
1231 goto skip_linkparms;
1232 }
1233
1234 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1235 /* skip link-specific parameters from interior routers */
1236 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1237 ND_PRINTK(2, info,
1238 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1239 __func__, skb->dev->name);
1240 goto skip_linkparms;
1241 }
1242 #endif
1243
1244 if (in6_dev->if_flags & IF_RS_SENT) {
1245 /*
1246 * flag that an RA was received after an RS was sent
1247 * out on this interface.
1248 */
1249 in6_dev->if_flags |= IF_RA_RCVD;
1250 }
1251
1252 /*
1253 * Remember the managed/otherconf flags from most recently
1254 * received RA message (RFC 2462) -- yoshfuji
1255 */
1256 old_if_flags = in6_dev->if_flags;
1257 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1258 IF_RA_OTHERCONF)) |
1259 (ra_msg->icmph.icmp6_addrconf_managed ?
1260 IF_RA_MANAGED : 0) |
1261 (ra_msg->icmph.icmp6_addrconf_other ?
1262 IF_RA_OTHERCONF : 0);
1263
1264 if (old_if_flags != in6_dev->if_flags)
1265 send_ifinfo_notify = true;
1266
1267 if (!in6_dev->cnf.accept_ra_defrtr) {
1268 ND_PRINTK(2, info,
1269 "RA: %s, defrtr is false for dev: %s\n",
1270 __func__, skb->dev->name);
1271 goto skip_defrtr;
1272 }
1273
1274 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1275 if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_lft) {
1276 ND_PRINTK(2, info,
1277 "RA: router lifetime (%ds) is too short: %s\n",
1278 lifetime, skb->dev->name);
1279 goto skip_defrtr;
1280 }
1281
1282 /* Do not accept RA with source-addr found on local machine unless
1283 * accept_ra_from_local is set to true.
1284 */
1285 net = dev_net(in6_dev->dev);
1286 if (!in6_dev->cnf.accept_ra_from_local &&
1287 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1288 ND_PRINTK(2, info,
1289 "RA from local address detected on dev: %s: default router ignored\n",
1290 skb->dev->name);
1291 goto skip_defrtr;
1292 }
1293
1294 #ifdef CONFIG_IPV6_ROUTER_PREF
1295 pref = ra_msg->icmph.icmp6_router_pref;
1296 /* 10b is handled as if it were 00b (medium) */
1297 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1298 !in6_dev->cnf.accept_ra_rtr_pref)
1299 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1300 #endif
1301 /* routes added from RAs do not use nexthop objects */
1302 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1303 if (rt) {
1304 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1305 rt->fib6_nh->fib_nh_dev, NULL,
1306 &ipv6_hdr(skb)->saddr);
1307 if (!neigh) {
1308 ND_PRINTK(0, err,
1309 "RA: %s got default router without neighbour\n",
1310 __func__);
1311 fib6_info_release(rt);
1312 return;
1313 }
1314 }
1315 if (rt && lifetime == 0) {
1316 ip6_del_rt(net, rt, false);
1317 rt = NULL;
1318 }
1319
1320 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1321 rt, lifetime, skb->dev->name);
1322 if (!rt && lifetime) {
1323 ND_PRINTK(3, info, "RA: adding default router\n");
1324
1325 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1326 skb->dev, pref);
1327 if (!rt) {
1328 ND_PRINTK(0, err,
1329 "RA: %s failed to add default route\n",
1330 __func__);
1331 return;
1332 }
1333
1334 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1335 rt->fib6_nh->fib_nh_dev, NULL,
1336 &ipv6_hdr(skb)->saddr);
1337 if (!neigh) {
1338 ND_PRINTK(0, err,
1339 "RA: %s got default router without neighbour\n",
1340 __func__);
1341 fib6_info_release(rt);
1342 return;
1343 }
1344 neigh->flags |= NTF_ROUTER;
1345 } else if (rt) {
1346 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1347 }
1348
1349 if (rt)
1350 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1351 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1352 ra_msg->icmph.icmp6_hop_limit) {
1353 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1354 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1355 fib6_metric_set(rt, RTAX_HOPLIMIT,
1356 ra_msg->icmph.icmp6_hop_limit);
1357 } else {
1358 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1359 }
1360 }
1361
1362 skip_defrtr:
1363
1364 /*
1365 * Update Reachable Time and Retrans Timer
1366 */
1367
1368 if (in6_dev->nd_parms) {
1369 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1370
1371 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1372 rtime = (rtime*HZ)/1000;
1373 if (rtime < HZ/100)
1374 rtime = HZ/100;
1375 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1376 in6_dev->tstamp = jiffies;
1377 send_ifinfo_notify = true;
1378 }
1379
1380 rtime = ntohl(ra_msg->reachable_time);
1381 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1382 rtime = (rtime*HZ)/1000;
1383
1384 if (rtime < HZ/10)
1385 rtime = HZ/10;
1386
1387 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1388 NEIGH_VAR_SET(in6_dev->nd_parms,
1389 BASE_REACHABLE_TIME, rtime);
1390 NEIGH_VAR_SET(in6_dev->nd_parms,
1391 GC_STALETIME, 3 * rtime);
1392 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1393 in6_dev->tstamp = jiffies;
1394 send_ifinfo_notify = true;
1395 }
1396 }
1397 }
1398
1399 /*
1400 * Send a notify if RA changed managed/otherconf flags or timer settings
1401 */
1402 if (send_ifinfo_notify)
1403 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1404
1405 skip_linkparms:
1406
1407 /*
1408 * Process options.
1409 */
1410
1411 if (!neigh)
1412 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1413 skb->dev, 1);
1414 if (neigh) {
1415 u8 *lladdr = NULL;
1416 if (ndopts.nd_opts_src_lladdr) {
1417 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1418 skb->dev);
1419 if (!lladdr) {
1420 ND_PRINTK(2, warn,
1421 "RA: invalid link-layer address length\n");
1422 goto out;
1423 }
1424 }
1425 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1426 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1427 NEIGH_UPDATE_F_OVERRIDE|
1428 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1429 NEIGH_UPDATE_F_ISROUTER,
1430 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1431 }
1432
1433 if (!ipv6_accept_ra(in6_dev)) {
1434 ND_PRINTK(2, info,
1435 "RA: %s, accept_ra is false for dev: %s\n",
1436 __func__, skb->dev->name);
1437 goto out;
1438 }
1439
1440 #ifdef CONFIG_IPV6_ROUTE_INFO
1441 if (!in6_dev->cnf.accept_ra_from_local &&
1442 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1443 in6_dev->dev, 0)) {
1444 ND_PRINTK(2, info,
1445 "RA from local address detected on dev: %s: router info ignored.\n",
1446 skb->dev->name);
1447 goto skip_routeinfo;
1448 }
1449
1450 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1451 struct nd_opt_hdr *p;
1452 for (p = ndopts.nd_opts_ri;
1453 p;
1454 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1455 struct route_info *ri = (struct route_info *)p;
1456 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1457 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1458 ri->prefix_len == 0)
1459 continue;
1460 #endif
1461 if (ri->prefix_len == 0 &&
1462 !in6_dev->cnf.accept_ra_defrtr)
1463 continue;
1464 if (ri->lifetime != 0 &&
1465 ntohl(ri->lifetime) < in6_dev->cnf.accept_ra_min_lft)
1466 continue;
1467 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1468 continue;
1469 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1470 continue;
1471 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1472 &ipv6_hdr(skb)->saddr);
1473 }
1474 }
1475
1476 skip_routeinfo:
1477 #endif
1478
1479 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1480 /* skip link-specific ndopts from interior routers */
1481 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1482 ND_PRINTK(2, info,
1483 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1484 __func__, skb->dev->name);
1485 goto out;
1486 }
1487 #endif
1488
1489 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1490 struct nd_opt_hdr *p;
1491 for (p = ndopts.nd_opts_pi;
1492 p;
1493 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1494 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1495 (p->nd_opt_len) << 3,
1496 ndopts.nd_opts_src_lladdr != NULL);
1497 }
1498 }
1499
1500 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1501 __be32 n;
1502 u32 mtu;
1503
1504 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1505 mtu = ntohl(n);
1506
1507 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1508 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1509 } else if (in6_dev->cnf.mtu6 != mtu) {
1510 in6_dev->cnf.mtu6 = mtu;
1511 fib6_metric_set(rt, RTAX_MTU, mtu);
1512 rt6_mtu_change(skb->dev, mtu);
1513 }
1514 }
1515
1516 if (ndopts.nd_useropts) {
1517 struct nd_opt_hdr *p;
1518 for (p = ndopts.nd_useropts;
1519 p;
1520 p = ndisc_next_useropt(skb->dev, p,
1521 ndopts.nd_useropts_end)) {
1522 ndisc_ra_useropt(skb, p);
1523 }
1524 }
1525
1526 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1527 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1528 }
1529 out:
1530 fib6_info_release(rt);
1531 if (neigh)
1532 neigh_release(neigh);
1533 }
1534
ndisc_redirect_rcv(struct sk_buff * skb)1535 static void ndisc_redirect_rcv(struct sk_buff *skb)
1536 {
1537 u8 *hdr;
1538 struct ndisc_options ndopts;
1539 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1540 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1541 offsetof(struct rd_msg, opt));
1542
1543 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1544 switch (skb->ndisc_nodetype) {
1545 case NDISC_NODETYPE_HOST:
1546 case NDISC_NODETYPE_NODEFAULT:
1547 ND_PRINTK(2, warn,
1548 "Redirect: from host or unauthorized router\n");
1549 return;
1550 }
1551 #endif
1552
1553 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1554 ND_PRINTK(2, warn,
1555 "Redirect: source address is not link-local\n");
1556 return;
1557 }
1558
1559 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1560 return;
1561
1562 if (!ndopts.nd_opts_rh) {
1563 ip6_redirect_no_header(skb, dev_net(skb->dev),
1564 skb->dev->ifindex);
1565 return;
1566 }
1567
1568 hdr = (u8 *)ndopts.nd_opts_rh;
1569 hdr += 8;
1570 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1571 return;
1572
1573 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1574 }
1575
ndisc_fill_redirect_hdr_option(struct sk_buff * skb,struct sk_buff * orig_skb,int rd_len)1576 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1577 struct sk_buff *orig_skb,
1578 int rd_len)
1579 {
1580 u8 *opt = skb_put(skb, rd_len);
1581
1582 memset(opt, 0, 8);
1583 *(opt++) = ND_OPT_REDIRECT_HDR;
1584 *(opt++) = (rd_len >> 3);
1585 opt += 6;
1586
1587 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1588 rd_len - 8);
1589 }
1590
ndisc_send_redirect(struct sk_buff * skb,const struct in6_addr * target)1591 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1592 {
1593 struct net_device *dev = skb->dev;
1594 struct net *net = dev_net(dev);
1595 struct sock *sk = net->ipv6.ndisc_sk;
1596 int optlen = 0;
1597 struct inet_peer *peer;
1598 struct sk_buff *buff;
1599 struct rd_msg *msg;
1600 struct in6_addr saddr_buf;
1601 struct rt6_info *rt;
1602 struct dst_entry *dst;
1603 struct flowi6 fl6;
1604 int rd_len;
1605 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1606 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1607 bool ret;
1608
1609 if (netif_is_l3_master(skb->dev)) {
1610 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1611 if (!dev)
1612 return;
1613 }
1614
1615 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1616 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1617 dev->name);
1618 return;
1619 }
1620
1621 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1622 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1623 ND_PRINTK(2, warn,
1624 "Redirect: target address is not link-local unicast\n");
1625 return;
1626 }
1627
1628 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1629 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1630
1631 dst = ip6_route_output(net, NULL, &fl6);
1632 if (dst->error) {
1633 dst_release(dst);
1634 return;
1635 }
1636 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1637 if (IS_ERR(dst))
1638 return;
1639
1640 rt = (struct rt6_info *) dst;
1641
1642 if (rt->rt6i_flags & RTF_GATEWAY) {
1643 ND_PRINTK(2, warn,
1644 "Redirect: destination is not a neighbour\n");
1645 goto release;
1646 }
1647 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1648 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1649 if (peer)
1650 inet_putpeer(peer);
1651 if (!ret)
1652 goto release;
1653
1654 if (dev->addr_len) {
1655 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1656 if (!neigh) {
1657 ND_PRINTK(2, warn,
1658 "Redirect: no neigh for target address\n");
1659 goto release;
1660 }
1661
1662 read_lock_bh(&neigh->lock);
1663 if (neigh->nud_state & NUD_VALID) {
1664 memcpy(ha_buf, neigh->ha, dev->addr_len);
1665 read_unlock_bh(&neigh->lock);
1666 ha = ha_buf;
1667 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1668 ops_data_buf,
1669 &ops_data);
1670 } else
1671 read_unlock_bh(&neigh->lock);
1672
1673 neigh_release(neigh);
1674 }
1675
1676 rd_len = min_t(unsigned int,
1677 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1678 skb->len + 8);
1679 rd_len &= ~0x7;
1680 optlen += rd_len;
1681
1682 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1683 if (!buff)
1684 goto release;
1685
1686 msg = skb_put(buff, sizeof(*msg));
1687 *msg = (struct rd_msg) {
1688 .icmph = {
1689 .icmp6_type = NDISC_REDIRECT,
1690 },
1691 .target = *target,
1692 .dest = ipv6_hdr(skb)->daddr,
1693 };
1694
1695 /*
1696 * include target_address option
1697 */
1698
1699 if (ha)
1700 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1701
1702 /*
1703 * build redirect option and copy skb over to the new packet.
1704 */
1705
1706 if (rd_len)
1707 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1708
1709 skb_dst_set(buff, dst);
1710 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1711 return;
1712
1713 release:
1714 dst_release(dst);
1715 }
1716
pndisc_redo(struct sk_buff * skb)1717 static void pndisc_redo(struct sk_buff *skb)
1718 {
1719 ndisc_recv_ns(skb);
1720 kfree_skb(skb);
1721 }
1722
ndisc_is_multicast(const void * pkey)1723 static int ndisc_is_multicast(const void *pkey)
1724 {
1725 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1726 }
1727
ndisc_suppress_frag_ndisc(struct sk_buff * skb)1728 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1729 {
1730 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1731
1732 if (!idev)
1733 return true;
1734 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1735 idev->cnf.suppress_frag_ndisc) {
1736 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1737 return true;
1738 }
1739 return false;
1740 }
1741
ndisc_rcv(struct sk_buff * skb)1742 int ndisc_rcv(struct sk_buff *skb)
1743 {
1744 struct nd_msg *msg;
1745
1746 if (ndisc_suppress_frag_ndisc(skb))
1747 return 0;
1748
1749 if (skb_linearize(skb))
1750 return 0;
1751
1752 msg = (struct nd_msg *)skb_transport_header(skb);
1753
1754 __skb_push(skb, skb->data - skb_transport_header(skb));
1755
1756 if (ipv6_hdr(skb)->hop_limit != 255) {
1757 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1758 ipv6_hdr(skb)->hop_limit);
1759 return 0;
1760 }
1761
1762 if (msg->icmph.icmp6_code != 0) {
1763 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1764 msg->icmph.icmp6_code);
1765 return 0;
1766 }
1767
1768 switch (msg->icmph.icmp6_type) {
1769 case NDISC_NEIGHBOUR_SOLICITATION:
1770 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1771 ndisc_recv_ns(skb);
1772 break;
1773
1774 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1775 ndisc_recv_na(skb);
1776 break;
1777
1778 case NDISC_ROUTER_SOLICITATION:
1779 ndisc_recv_rs(skb);
1780 break;
1781
1782 case NDISC_ROUTER_ADVERTISEMENT:
1783 ndisc_router_discovery(skb);
1784 break;
1785
1786 case NDISC_REDIRECT:
1787 ndisc_redirect_rcv(skb);
1788 break;
1789 }
1790
1791 return 0;
1792 }
1793
ndisc_netdev_event(struct notifier_block * this,unsigned long event,void * ptr)1794 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1795 {
1796 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1797 struct netdev_notifier_change_info *change_info;
1798 struct net *net = dev_net(dev);
1799 struct inet6_dev *idev;
1800
1801 switch (event) {
1802 case NETDEV_CHANGEADDR:
1803 neigh_changeaddr(&nd_tbl, dev);
1804 fib6_run_gc(0, net, false);
1805 fallthrough;
1806 case NETDEV_UP:
1807 idev = in6_dev_get(dev);
1808 if (!idev)
1809 break;
1810 if (idev->cnf.ndisc_notify ||
1811 net->ipv6.devconf_all->ndisc_notify)
1812 ndisc_send_unsol_na(dev);
1813 in6_dev_put(idev);
1814 break;
1815 case NETDEV_CHANGE:
1816 change_info = ptr;
1817 if (change_info->flags_changed & IFF_NOARP)
1818 neigh_changeaddr(&nd_tbl, dev);
1819 if (!netif_carrier_ok(dev))
1820 neigh_carrier_down(&nd_tbl, dev);
1821 break;
1822 case NETDEV_DOWN:
1823 neigh_ifdown(&nd_tbl, dev);
1824 fib6_run_gc(0, net, false);
1825 break;
1826 case NETDEV_NOTIFY_PEERS:
1827 ndisc_send_unsol_na(dev);
1828 break;
1829 default:
1830 break;
1831 }
1832
1833 return NOTIFY_DONE;
1834 }
1835
1836 static struct notifier_block ndisc_netdev_notifier = {
1837 .notifier_call = ndisc_netdev_event,
1838 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1839 };
1840
1841 #ifdef CONFIG_SYSCTL
ndisc_warn_deprecated_sysctl(struct ctl_table * ctl,const char * func,const char * dev_name)1842 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1843 const char *func, const char *dev_name)
1844 {
1845 static char warncomm[TASK_COMM_LEN];
1846 static int warned;
1847 if (strcmp(warncomm, current->comm) && warned < 5) {
1848 strcpy(warncomm, current->comm);
1849 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1850 warncomm, func,
1851 dev_name, ctl->procname,
1852 dev_name, ctl->procname);
1853 warned++;
1854 }
1855 }
1856
ndisc_ifinfo_sysctl_change(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1857 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1858 size_t *lenp, loff_t *ppos)
1859 {
1860 struct net_device *dev = ctl->extra1;
1861 struct inet6_dev *idev;
1862 int ret;
1863
1864 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1865 (strcmp(ctl->procname, "base_reachable_time") == 0))
1866 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1867
1868 if (strcmp(ctl->procname, "retrans_time") == 0)
1869 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1870
1871 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1872 ret = neigh_proc_dointvec_jiffies(ctl, write,
1873 buffer, lenp, ppos);
1874
1875 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1876 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1877 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1878 buffer, lenp, ppos);
1879 else
1880 ret = -1;
1881
1882 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1883 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1884 idev->nd_parms->reachable_time =
1885 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1886 idev->tstamp = jiffies;
1887 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1888 in6_dev_put(idev);
1889 }
1890 return ret;
1891 }
1892
1893
1894 #endif
1895
ndisc_net_init(struct net * net)1896 static int __net_init ndisc_net_init(struct net *net)
1897 {
1898 struct ipv6_pinfo *np;
1899 struct sock *sk;
1900 int err;
1901
1902 err = inet_ctl_sock_create(&sk, PF_INET6,
1903 SOCK_RAW, IPPROTO_ICMPV6, net);
1904 if (err < 0) {
1905 ND_PRINTK(0, err,
1906 "NDISC: Failed to initialize the control socket (err %d)\n",
1907 err);
1908 return err;
1909 }
1910
1911 net->ipv6.ndisc_sk = sk;
1912
1913 np = inet6_sk(sk);
1914 np->hop_limit = 255;
1915 /* Do not loopback ndisc messages */
1916 np->mc_loop = 0;
1917
1918 return 0;
1919 }
1920
ndisc_net_exit(struct net * net)1921 static void __net_exit ndisc_net_exit(struct net *net)
1922 {
1923 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1924 }
1925
1926 static struct pernet_operations ndisc_net_ops = {
1927 .init = ndisc_net_init,
1928 .exit = ndisc_net_exit,
1929 };
1930
ndisc_init(void)1931 int __init ndisc_init(void)
1932 {
1933 int err;
1934
1935 err = register_pernet_subsys(&ndisc_net_ops);
1936 if (err)
1937 return err;
1938 /*
1939 * Initialize the neighbour table
1940 */
1941 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1942
1943 #ifdef CONFIG_SYSCTL
1944 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1945 ndisc_ifinfo_sysctl_change);
1946 if (err)
1947 goto out_unregister_pernet;
1948 out:
1949 #endif
1950 return err;
1951
1952 #ifdef CONFIG_SYSCTL
1953 out_unregister_pernet:
1954 unregister_pernet_subsys(&ndisc_net_ops);
1955 goto out;
1956 #endif
1957 }
1958
ndisc_late_init(void)1959 int __init ndisc_late_init(void)
1960 {
1961 return register_netdevice_notifier(&ndisc_netdev_notifier);
1962 }
1963
ndisc_late_cleanup(void)1964 void ndisc_late_cleanup(void)
1965 {
1966 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1967 }
1968
ndisc_cleanup(void)1969 void ndisc_cleanup(void)
1970 {
1971 #ifdef CONFIG_SYSCTL
1972 neigh_sysctl_unregister(&nd_tbl.parms);
1973 #endif
1974 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1975 unregister_pernet_subsys(&ndisc_net_ops);
1976 }
1977