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 sock *sk = dev_net(dev)->ipv6.ndisc_sk;
419 struct sk_buff *skb;
420
421 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
422 if (!skb) {
423 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
424 __func__);
425 return NULL;
426 }
427
428 skb->protocol = htons(ETH_P_IPV6);
429 skb->dev = dev;
430
431 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
432 skb_reset_transport_header(skb);
433
434 /* Manually assign socket ownership as we avoid calling
435 * sock_alloc_send_pskb() to bypass wmem buffer limits
436 */
437 skb_set_owner_w(skb, sk);
438
439 return skb;
440 }
441
ip6_nd_hdr(struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,int hop_limit,int len)442 static void ip6_nd_hdr(struct sk_buff *skb,
443 const struct in6_addr *saddr,
444 const struct in6_addr *daddr,
445 int hop_limit, int len)
446 {
447 struct ipv6hdr *hdr;
448 struct inet6_dev *idev;
449 unsigned tclass;
450
451 rcu_read_lock();
452 idev = __in6_dev_get(skb->dev);
453 tclass = idev ? idev->cnf.ndisc_tclass : 0;
454 rcu_read_unlock();
455
456 skb_push(skb, sizeof(*hdr));
457 skb_reset_network_header(skb);
458 hdr = ipv6_hdr(skb);
459
460 ip6_flow_hdr(hdr, tclass, 0);
461
462 hdr->payload_len = htons(len);
463 hdr->nexthdr = IPPROTO_ICMPV6;
464 hdr->hop_limit = hop_limit;
465
466 hdr->saddr = *saddr;
467 hdr->daddr = *daddr;
468 }
469
ndisc_send_skb(struct sk_buff * skb,const struct in6_addr * daddr,const struct in6_addr * saddr)470 static void ndisc_send_skb(struct sk_buff *skb,
471 const struct in6_addr *daddr,
472 const struct in6_addr *saddr)
473 {
474 struct dst_entry *dst = skb_dst(skb);
475 struct net *net = dev_net(skb->dev);
476 struct sock *sk = net->ipv6.ndisc_sk;
477 struct inet6_dev *idev;
478 int err;
479 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
480 u8 type;
481
482 type = icmp6h->icmp6_type;
483
484 if (!dst) {
485 struct flowi6 fl6;
486 int oif = skb->dev->ifindex;
487
488 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
489 dst = icmp6_dst_alloc(skb->dev, &fl6);
490 if (IS_ERR(dst)) {
491 kfree_skb(skb);
492 return;
493 }
494
495 skb_dst_set(skb, dst);
496 }
497
498 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
499 IPPROTO_ICMPV6,
500 csum_partial(icmp6h,
501 skb->len, 0));
502
503 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
504
505 rcu_read_lock();
506 idev = __in6_dev_get(dst->dev);
507 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
508
509 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
510 net, sk, skb, NULL, dst->dev,
511 dst_output);
512 if (!err) {
513 ICMP6MSGOUT_INC_STATS(net, idev, type);
514 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
515 }
516
517 rcu_read_unlock();
518 }
519
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)520 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
521 const struct in6_addr *solicited_addr,
522 bool router, bool solicited, bool override, bool inc_opt)
523 {
524 struct sk_buff *skb;
525 struct in6_addr tmpaddr;
526 struct inet6_ifaddr *ifp;
527 const struct in6_addr *src_addr;
528 struct nd_msg *msg;
529 int optlen = 0;
530
531 /* for anycast or proxy, solicited_addr != src_addr */
532 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
533 if (ifp) {
534 src_addr = solicited_addr;
535 if (ifp->flags & IFA_F_OPTIMISTIC)
536 override = false;
537 inc_opt |= ifp->idev->cnf.force_tllao;
538 in6_ifa_put(ifp);
539 } else {
540 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
541 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
542 &tmpaddr))
543 return;
544 src_addr = &tmpaddr;
545 }
546
547 if (!dev->addr_len)
548 inc_opt = false;
549 if (inc_opt)
550 optlen += ndisc_opt_addr_space(dev,
551 NDISC_NEIGHBOUR_ADVERTISEMENT);
552
553 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
554 if (!skb)
555 return;
556
557 msg = skb_put(skb, sizeof(*msg));
558 *msg = (struct nd_msg) {
559 .icmph = {
560 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
561 .icmp6_router = router,
562 .icmp6_solicited = solicited,
563 .icmp6_override = override,
564 },
565 .target = *solicited_addr,
566 };
567
568 if (inc_opt)
569 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
570 dev->dev_addr,
571 NDISC_NEIGHBOUR_ADVERTISEMENT);
572
573 ndisc_send_skb(skb, daddr, src_addr);
574 }
575
ndisc_send_unsol_na(struct net_device * dev)576 static void ndisc_send_unsol_na(struct net_device *dev)
577 {
578 struct inet6_dev *idev;
579 struct inet6_ifaddr *ifa;
580
581 idev = in6_dev_get(dev);
582 if (!idev)
583 return;
584
585 read_lock_bh(&idev->lock);
586 list_for_each_entry(ifa, &idev->addr_list, if_list) {
587 /* skip tentative addresses until dad completes */
588 if (ifa->flags & IFA_F_TENTATIVE &&
589 !(ifa->flags & IFA_F_OPTIMISTIC))
590 continue;
591
592 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
593 /*router=*/ !!idev->cnf.forwarding,
594 /*solicited=*/ false, /*override=*/ true,
595 /*inc_opt=*/ true);
596 }
597 read_unlock_bh(&idev->lock);
598
599 in6_dev_put(idev);
600 }
601
ndisc_send_ns(struct net_device * dev,const struct in6_addr * solicit,const struct in6_addr * daddr,const struct in6_addr * saddr,u64 nonce)602 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
603 const struct in6_addr *daddr, const struct in6_addr *saddr,
604 u64 nonce)
605 {
606 struct sk_buff *skb;
607 struct in6_addr addr_buf;
608 int inc_opt = dev->addr_len;
609 int optlen = 0;
610 struct nd_msg *msg;
611
612 if (!saddr) {
613 if (ipv6_get_lladdr(dev, &addr_buf,
614 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
615 return;
616 saddr = &addr_buf;
617 }
618
619 if (ipv6_addr_any(saddr))
620 inc_opt = false;
621 if (inc_opt)
622 optlen += ndisc_opt_addr_space(dev,
623 NDISC_NEIGHBOUR_SOLICITATION);
624 if (nonce != 0)
625 optlen += 8;
626
627 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
628 if (!skb)
629 return;
630
631 msg = skb_put(skb, sizeof(*msg));
632 *msg = (struct nd_msg) {
633 .icmph = {
634 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
635 },
636 .target = *solicit,
637 };
638
639 if (inc_opt)
640 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
641 dev->dev_addr,
642 NDISC_NEIGHBOUR_SOLICITATION);
643 if (nonce != 0) {
644 u8 *opt = skb_put(skb, 8);
645
646 opt[0] = ND_OPT_NONCE;
647 opt[1] = 8 >> 3;
648 memcpy(opt + 2, &nonce, 6);
649 }
650
651 ndisc_send_skb(skb, daddr, saddr);
652 }
653
ndisc_send_rs(struct net_device * dev,const struct in6_addr * saddr,const struct in6_addr * daddr)654 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
655 const struct in6_addr *daddr)
656 {
657 struct sk_buff *skb;
658 struct rs_msg *msg;
659 int send_sllao = dev->addr_len;
660 int optlen = 0;
661
662 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
663 /*
664 * According to section 2.2 of RFC 4429, we must not
665 * send router solicitations with a sllao from
666 * optimistic addresses, but we may send the solicitation
667 * if we don't include the sllao. So here we check
668 * if our address is optimistic, and if so, we
669 * suppress the inclusion of the sllao.
670 */
671 if (send_sllao) {
672 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
673 dev, 1);
674 if (ifp) {
675 if (ifp->flags & IFA_F_OPTIMISTIC) {
676 send_sllao = 0;
677 }
678 in6_ifa_put(ifp);
679 } else {
680 send_sllao = 0;
681 }
682 }
683 #endif
684 if (send_sllao)
685 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
686
687 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
688 if (!skb)
689 return;
690
691 msg = skb_put(skb, sizeof(*msg));
692 *msg = (struct rs_msg) {
693 .icmph = {
694 .icmp6_type = NDISC_ROUTER_SOLICITATION,
695 },
696 };
697
698 if (send_sllao)
699 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
700 dev->dev_addr,
701 NDISC_ROUTER_SOLICITATION);
702
703 ndisc_send_skb(skb, daddr, saddr);
704 }
705
706
ndisc_error_report(struct neighbour * neigh,struct sk_buff * skb)707 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
708 {
709 /*
710 * "The sender MUST return an ICMP
711 * destination unreachable"
712 */
713 dst_link_failure(skb);
714 kfree_skb(skb);
715 }
716
717 /* Called with locked neigh: either read or both */
718
ndisc_solicit(struct neighbour * neigh,struct sk_buff * skb)719 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
720 {
721 struct in6_addr *saddr = NULL;
722 struct in6_addr mcaddr;
723 struct net_device *dev = neigh->dev;
724 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
725 int probes = atomic_read(&neigh->probes);
726
727 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
728 dev, false, 1,
729 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
730 saddr = &ipv6_hdr(skb)->saddr;
731 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
732 if (probes < 0) {
733 if (!(neigh->nud_state & NUD_VALID)) {
734 ND_PRINTK(1, dbg,
735 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
736 __func__, target);
737 }
738 ndisc_send_ns(dev, target, target, saddr, 0);
739 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
740 neigh_app_ns(neigh);
741 } else {
742 addrconf_addr_solict_mult(target, &mcaddr);
743 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
744 }
745 }
746
pndisc_is_router(const void * pkey,struct net_device * dev)747 static int pndisc_is_router(const void *pkey,
748 struct net_device *dev)
749 {
750 struct pneigh_entry *n;
751 int ret = -1;
752
753 read_lock_bh(&nd_tbl.lock);
754 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
755 if (n)
756 ret = !!(n->flags & NTF_ROUTER);
757 read_unlock_bh(&nd_tbl.lock);
758
759 return ret;
760 }
761
ndisc_update(const struct net_device * dev,struct neighbour * neigh,const u8 * lladdr,u8 new,u32 flags,u8 icmp6_type,struct ndisc_options * ndopts)762 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
763 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
764 struct ndisc_options *ndopts)
765 {
766 neigh_update(neigh, lladdr, new, flags, 0);
767 /* report ndisc ops about neighbour update */
768 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
769 }
770
ndisc_recv_ns(struct sk_buff * skb)771 static void ndisc_recv_ns(struct sk_buff *skb)
772 {
773 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
774 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
775 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
776 u8 *lladdr = NULL;
777 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
778 offsetof(struct nd_msg, opt));
779 struct ndisc_options ndopts;
780 struct net_device *dev = skb->dev;
781 struct inet6_ifaddr *ifp;
782 struct inet6_dev *idev = NULL;
783 struct neighbour *neigh;
784 int dad = ipv6_addr_any(saddr);
785 bool inc;
786 int is_router = -1;
787 u64 nonce = 0;
788
789 if (skb->len < sizeof(struct nd_msg)) {
790 ND_PRINTK(2, warn, "NS: packet too short\n");
791 return;
792 }
793
794 if (ipv6_addr_is_multicast(&msg->target)) {
795 ND_PRINTK(2, warn, "NS: multicast target address\n");
796 return;
797 }
798
799 /*
800 * RFC2461 7.1.1:
801 * DAD has to be destined for solicited node multicast address.
802 */
803 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
804 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
805 return;
806 }
807
808 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
809 ND_PRINTK(2, warn, "NS: invalid ND options\n");
810 return;
811 }
812
813 if (ndopts.nd_opts_src_lladdr) {
814 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
815 if (!lladdr) {
816 ND_PRINTK(2, warn,
817 "NS: invalid link-layer address length\n");
818 return;
819 }
820
821 /* RFC2461 7.1.1:
822 * If the IP source address is the unspecified address,
823 * there MUST NOT be source link-layer address option
824 * in the message.
825 */
826 if (dad) {
827 ND_PRINTK(2, warn,
828 "NS: bad DAD packet (link-layer address option)\n");
829 return;
830 }
831 }
832 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
833 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
834
835 inc = ipv6_addr_is_multicast(daddr);
836
837 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
838 if (ifp) {
839 have_ifp:
840 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
841 if (dad) {
842 if (nonce != 0 && ifp->dad_nonce == nonce) {
843 u8 *np = (u8 *)&nonce;
844 /* Matching nonce if looped back */
845 ND_PRINTK(2, notice,
846 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
847 ifp->idev->dev->name,
848 &ifp->addr, np);
849 goto out;
850 }
851 /*
852 * We are colliding with another node
853 * who is doing DAD
854 * so fail our DAD process
855 */
856 addrconf_dad_failure(skb, ifp);
857 return;
858 } else {
859 /*
860 * This is not a dad solicitation.
861 * If we are an optimistic node,
862 * we should respond.
863 * Otherwise, we should ignore it.
864 */
865 if (!(ifp->flags & IFA_F_OPTIMISTIC))
866 goto out;
867 }
868 }
869
870 idev = ifp->idev;
871 } else {
872 struct net *net = dev_net(dev);
873
874 /* perhaps an address on the master device */
875 if (netif_is_l3_slave(dev)) {
876 struct net_device *mdev;
877
878 mdev = netdev_master_upper_dev_get_rcu(dev);
879 if (mdev) {
880 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
881 if (ifp)
882 goto have_ifp;
883 }
884 }
885
886 idev = in6_dev_get(dev);
887 if (!idev) {
888 /* XXX: count this drop? */
889 return;
890 }
891
892 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
893 (idev->cnf.forwarding &&
894 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
895 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
896 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
897 skb->pkt_type != PACKET_HOST &&
898 inc &&
899 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
900 /*
901 * for anycast or proxy,
902 * sender should delay its response
903 * by a random time between 0 and
904 * MAX_ANYCAST_DELAY_TIME seconds.
905 * (RFC2461) -- yoshfuji
906 */
907 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
908 if (n)
909 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
910 goto out;
911 }
912 } else
913 goto out;
914 }
915
916 if (is_router < 0)
917 is_router = idev->cnf.forwarding;
918
919 if (dad) {
920 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
921 !!is_router, false, (ifp != NULL), true);
922 goto out;
923 }
924
925 if (inc)
926 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
927 else
928 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
929
930 /*
931 * update / create cache entry
932 * for the source address
933 */
934 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
935 !inc || lladdr || !dev->addr_len);
936 if (neigh)
937 ndisc_update(dev, neigh, lladdr, NUD_STALE,
938 NEIGH_UPDATE_F_WEAK_OVERRIDE|
939 NEIGH_UPDATE_F_OVERRIDE,
940 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
941 if (neigh || !dev->header_ops) {
942 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
943 true, (ifp != NULL && inc), inc);
944 if (neigh)
945 neigh_release(neigh);
946 }
947
948 out:
949 if (ifp)
950 in6_ifa_put(ifp);
951 else
952 in6_dev_put(idev);
953 }
954
ndisc_recv_na(struct sk_buff * skb)955 static void ndisc_recv_na(struct sk_buff *skb)
956 {
957 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
958 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
959 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
960 u8 *lladdr = NULL;
961 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
962 offsetof(struct nd_msg, opt));
963 struct ndisc_options ndopts;
964 struct net_device *dev = skb->dev;
965 struct inet6_dev *idev = __in6_dev_get(dev);
966 struct inet6_ifaddr *ifp;
967 struct neighbour *neigh;
968
969 if (skb->len < sizeof(struct nd_msg)) {
970 ND_PRINTK(2, warn, "NA: packet too short\n");
971 return;
972 }
973
974 if (ipv6_addr_is_multicast(&msg->target)) {
975 ND_PRINTK(2, warn, "NA: target address is multicast\n");
976 return;
977 }
978
979 if (ipv6_addr_is_multicast(daddr) &&
980 msg->icmph.icmp6_solicited) {
981 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
982 return;
983 }
984
985 /* For some 802.11 wireless deployments (and possibly other networks),
986 * there will be a NA proxy and unsolicitd packets are attacks
987 * and thus should not be accepted.
988 */
989 if (!msg->icmph.icmp6_solicited && idev &&
990 idev->cnf.drop_unsolicited_na)
991 return;
992
993 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
994 ND_PRINTK(2, warn, "NS: invalid ND option\n");
995 return;
996 }
997 if (ndopts.nd_opts_tgt_lladdr) {
998 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
999 if (!lladdr) {
1000 ND_PRINTK(2, warn,
1001 "NA: invalid link-layer address length\n");
1002 return;
1003 }
1004 }
1005 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1006 if (ifp) {
1007 if (skb->pkt_type != PACKET_LOOPBACK
1008 && (ifp->flags & IFA_F_TENTATIVE)) {
1009 addrconf_dad_failure(skb, ifp);
1010 return;
1011 }
1012 /* What should we make now? The advertisement
1013 is invalid, but ndisc specs say nothing
1014 about it. It could be misconfiguration, or
1015 an smart proxy agent tries to help us :-)
1016
1017 We should not print the error if NA has been
1018 received from loopback - it is just our own
1019 unsolicited advertisement.
1020 */
1021 if (skb->pkt_type != PACKET_LOOPBACK)
1022 ND_PRINTK(1, warn,
1023 "NA: %pM advertised our address %pI6c on %s!\n",
1024 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1025 in6_ifa_put(ifp);
1026 return;
1027 }
1028 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1029
1030 if (neigh) {
1031 u8 old_flags = neigh->flags;
1032 struct net *net = dev_net(dev);
1033
1034 if (neigh->nud_state & NUD_FAILED)
1035 goto out;
1036
1037 /*
1038 * Don't update the neighbor cache entry on a proxy NA from
1039 * ourselves because either the proxied node is off link or it
1040 * has already sent a NA to us.
1041 */
1042 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1043 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1044 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1045 /* XXX: idev->cnf.proxy_ndp */
1046 goto out;
1047 }
1048
1049 ndisc_update(dev, neigh, lladdr,
1050 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1051 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1052 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1053 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1054 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1055 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1056
1057 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1058 /*
1059 * Change: router to host
1060 */
1061 rt6_clean_tohost(dev_net(dev), saddr);
1062 }
1063
1064 out:
1065 neigh_release(neigh);
1066 }
1067 }
1068
ndisc_recv_rs(struct sk_buff * skb)1069 static void ndisc_recv_rs(struct sk_buff *skb)
1070 {
1071 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1072 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1073 struct neighbour *neigh;
1074 struct inet6_dev *idev;
1075 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1076 struct ndisc_options ndopts;
1077 u8 *lladdr = NULL;
1078
1079 if (skb->len < sizeof(*rs_msg))
1080 return;
1081
1082 idev = __in6_dev_get(skb->dev);
1083 if (!idev) {
1084 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1085 return;
1086 }
1087
1088 /* Don't accept RS if we're not in router mode */
1089 if (!idev->cnf.forwarding)
1090 goto out;
1091
1092 /*
1093 * Don't update NCE if src = ::;
1094 * this implies that the source node has no ip address assigned yet.
1095 */
1096 if (ipv6_addr_any(saddr))
1097 goto out;
1098
1099 /* Parse ND options */
1100 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1101 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1102 goto out;
1103 }
1104
1105 if (ndopts.nd_opts_src_lladdr) {
1106 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1107 skb->dev);
1108 if (!lladdr)
1109 goto out;
1110 }
1111
1112 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1113 if (neigh) {
1114 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1115 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1116 NEIGH_UPDATE_F_OVERRIDE|
1117 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1118 NDISC_ROUTER_SOLICITATION, &ndopts);
1119 neigh_release(neigh);
1120 }
1121 out:
1122 return;
1123 }
1124
ndisc_ra_useropt(struct sk_buff * ra,struct nd_opt_hdr * opt)1125 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1126 {
1127 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1128 struct sk_buff *skb;
1129 struct nlmsghdr *nlh;
1130 struct nduseroptmsg *ndmsg;
1131 struct net *net = dev_net(ra->dev);
1132 int err;
1133 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1134 + (opt->nd_opt_len << 3));
1135 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1136
1137 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1138 if (!skb) {
1139 err = -ENOBUFS;
1140 goto errout;
1141 }
1142
1143 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1144 if (!nlh) {
1145 goto nla_put_failure;
1146 }
1147
1148 ndmsg = nlmsg_data(nlh);
1149 ndmsg->nduseropt_family = AF_INET6;
1150 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1151 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1152 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1153 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1154
1155 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1156
1157 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1158 goto nla_put_failure;
1159 nlmsg_end(skb, nlh);
1160
1161 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1162 return;
1163
1164 nla_put_failure:
1165 nlmsg_free(skb);
1166 err = -EMSGSIZE;
1167 errout:
1168 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1169 }
1170
ndisc_router_discovery(struct sk_buff * skb)1171 static void ndisc_router_discovery(struct sk_buff *skb)
1172 {
1173 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1174 struct neighbour *neigh = NULL;
1175 struct inet6_dev *in6_dev;
1176 struct fib6_info *rt = NULL;
1177 struct net *net;
1178 int lifetime;
1179 struct ndisc_options ndopts;
1180 int optlen;
1181 unsigned int pref = 0;
1182 __u32 old_if_flags;
1183 bool send_ifinfo_notify = false;
1184
1185 __u8 *opt = (__u8 *)(ra_msg + 1);
1186
1187 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1188 sizeof(struct ra_msg);
1189
1190 ND_PRINTK(2, info,
1191 "RA: %s, dev: %s\n",
1192 __func__, skb->dev->name);
1193 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1194 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1195 return;
1196 }
1197 if (optlen < 0) {
1198 ND_PRINTK(2, warn, "RA: packet too short\n");
1199 return;
1200 }
1201
1202 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1203 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1204 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1205 return;
1206 }
1207 #endif
1208
1209 /*
1210 * set the RA_RECV flag in the interface
1211 */
1212
1213 in6_dev = __in6_dev_get(skb->dev);
1214 if (!in6_dev) {
1215 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1216 skb->dev->name);
1217 return;
1218 }
1219
1220 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1221 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1222 return;
1223 }
1224
1225 if (!ipv6_accept_ra(in6_dev)) {
1226 ND_PRINTK(2, info,
1227 "RA: %s, did not accept ra for dev: %s\n",
1228 __func__, skb->dev->name);
1229 goto skip_linkparms;
1230 }
1231
1232 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1233 /* skip link-specific parameters from interior routers */
1234 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1235 ND_PRINTK(2, info,
1236 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1237 __func__, skb->dev->name);
1238 goto skip_linkparms;
1239 }
1240 #endif
1241
1242 if (in6_dev->if_flags & IF_RS_SENT) {
1243 /*
1244 * flag that an RA was received after an RS was sent
1245 * out on this interface.
1246 */
1247 in6_dev->if_flags |= IF_RA_RCVD;
1248 }
1249
1250 /*
1251 * Remember the managed/otherconf flags from most recently
1252 * received RA message (RFC 2462) -- yoshfuji
1253 */
1254 old_if_flags = in6_dev->if_flags;
1255 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1256 IF_RA_OTHERCONF)) |
1257 (ra_msg->icmph.icmp6_addrconf_managed ?
1258 IF_RA_MANAGED : 0) |
1259 (ra_msg->icmph.icmp6_addrconf_other ?
1260 IF_RA_OTHERCONF : 0);
1261
1262 if (old_if_flags != in6_dev->if_flags)
1263 send_ifinfo_notify = true;
1264
1265 if (!in6_dev->cnf.accept_ra_defrtr) {
1266 ND_PRINTK(2, info,
1267 "RA: %s, defrtr is false for dev: %s\n",
1268 __func__, skb->dev->name);
1269 goto skip_defrtr;
1270 }
1271
1272 /* Do not accept RA with source-addr found on local machine unless
1273 * accept_ra_from_local is set to true.
1274 */
1275 net = dev_net(in6_dev->dev);
1276 if (!in6_dev->cnf.accept_ra_from_local &&
1277 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1278 ND_PRINTK(2, info,
1279 "RA from local address detected on dev: %s: default router ignored\n",
1280 skb->dev->name);
1281 goto skip_defrtr;
1282 }
1283
1284 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1285
1286 #ifdef CONFIG_IPV6_ROUTER_PREF
1287 pref = ra_msg->icmph.icmp6_router_pref;
1288 /* 10b is handled as if it were 00b (medium) */
1289 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1290 !in6_dev->cnf.accept_ra_rtr_pref)
1291 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1292 #endif
1293 /* routes added from RAs do not use nexthop objects */
1294 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1295 if (rt) {
1296 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1297 rt->fib6_nh->fib_nh_dev, NULL,
1298 &ipv6_hdr(skb)->saddr);
1299 if (!neigh) {
1300 ND_PRINTK(0, err,
1301 "RA: %s got default router without neighbour\n",
1302 __func__);
1303 fib6_info_release(rt);
1304 return;
1305 }
1306 }
1307 if (rt && lifetime == 0) {
1308 ip6_del_rt(net, rt, false);
1309 rt = NULL;
1310 }
1311
1312 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
1313 rt, lifetime, skb->dev->name);
1314 if (!rt && lifetime) {
1315 ND_PRINTK(3, info, "RA: adding default router\n");
1316
1317 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1318 skb->dev, pref);
1319 if (!rt) {
1320 ND_PRINTK(0, err,
1321 "RA: %s failed to add default route\n",
1322 __func__);
1323 return;
1324 }
1325
1326 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1327 rt->fib6_nh->fib_nh_dev, NULL,
1328 &ipv6_hdr(skb)->saddr);
1329 if (!neigh) {
1330 ND_PRINTK(0, err,
1331 "RA: %s got default router without neighbour\n",
1332 __func__);
1333 fib6_info_release(rt);
1334 return;
1335 }
1336 neigh->flags |= NTF_ROUTER;
1337 } else if (rt) {
1338 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1339 }
1340
1341 if (rt)
1342 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1343 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1344 ra_msg->icmph.icmp6_hop_limit) {
1345 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1346 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1347 fib6_metric_set(rt, RTAX_HOPLIMIT,
1348 ra_msg->icmph.icmp6_hop_limit);
1349 } else {
1350 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1351 }
1352 }
1353
1354 skip_defrtr:
1355
1356 /*
1357 * Update Reachable Time and Retrans Timer
1358 */
1359
1360 if (in6_dev->nd_parms) {
1361 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1362
1363 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1364 rtime = (rtime*HZ)/1000;
1365 if (rtime < HZ/100)
1366 rtime = HZ/100;
1367 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1368 in6_dev->tstamp = jiffies;
1369 send_ifinfo_notify = true;
1370 }
1371
1372 rtime = ntohl(ra_msg->reachable_time);
1373 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1374 rtime = (rtime*HZ)/1000;
1375
1376 if (rtime < HZ/10)
1377 rtime = HZ/10;
1378
1379 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1380 NEIGH_VAR_SET(in6_dev->nd_parms,
1381 BASE_REACHABLE_TIME, rtime);
1382 NEIGH_VAR_SET(in6_dev->nd_parms,
1383 GC_STALETIME, 3 * rtime);
1384 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1385 in6_dev->tstamp = jiffies;
1386 send_ifinfo_notify = true;
1387 }
1388 }
1389 }
1390
1391 /*
1392 * Send a notify if RA changed managed/otherconf flags or timer settings
1393 */
1394 if (send_ifinfo_notify)
1395 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1396
1397 skip_linkparms:
1398
1399 /*
1400 * Process options.
1401 */
1402
1403 if (!neigh)
1404 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1405 skb->dev, 1);
1406 if (neigh) {
1407 u8 *lladdr = NULL;
1408 if (ndopts.nd_opts_src_lladdr) {
1409 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1410 skb->dev);
1411 if (!lladdr) {
1412 ND_PRINTK(2, warn,
1413 "RA: invalid link-layer address length\n");
1414 goto out;
1415 }
1416 }
1417 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1418 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1419 NEIGH_UPDATE_F_OVERRIDE|
1420 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1421 NEIGH_UPDATE_F_ISROUTER,
1422 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1423 }
1424
1425 if (!ipv6_accept_ra(in6_dev)) {
1426 ND_PRINTK(2, info,
1427 "RA: %s, accept_ra is false for dev: %s\n",
1428 __func__, skb->dev->name);
1429 goto out;
1430 }
1431
1432 #ifdef CONFIG_IPV6_ROUTE_INFO
1433 if (!in6_dev->cnf.accept_ra_from_local &&
1434 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1435 in6_dev->dev, 0)) {
1436 ND_PRINTK(2, info,
1437 "RA from local address detected on dev: %s: router info ignored.\n",
1438 skb->dev->name);
1439 goto skip_routeinfo;
1440 }
1441
1442 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1443 struct nd_opt_hdr *p;
1444 for (p = ndopts.nd_opts_ri;
1445 p;
1446 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1447 struct route_info *ri = (struct route_info *)p;
1448 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1449 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1450 ri->prefix_len == 0)
1451 continue;
1452 #endif
1453 if (ri->prefix_len == 0 &&
1454 !in6_dev->cnf.accept_ra_defrtr)
1455 continue;
1456 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1457 continue;
1458 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1459 continue;
1460 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1461 &ipv6_hdr(skb)->saddr);
1462 }
1463 }
1464
1465 skip_routeinfo:
1466 #endif
1467
1468 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1469 /* skip link-specific ndopts from interior routers */
1470 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1471 ND_PRINTK(2, info,
1472 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1473 __func__, skb->dev->name);
1474 goto out;
1475 }
1476 #endif
1477
1478 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1479 struct nd_opt_hdr *p;
1480 for (p = ndopts.nd_opts_pi;
1481 p;
1482 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1483 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1484 (p->nd_opt_len) << 3,
1485 ndopts.nd_opts_src_lladdr != NULL);
1486 }
1487 }
1488
1489 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1490 __be32 n;
1491 u32 mtu;
1492
1493 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1494 mtu = ntohl(n);
1495
1496 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1497 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1498 } else if (in6_dev->cnf.mtu6 != mtu) {
1499 in6_dev->cnf.mtu6 = mtu;
1500 fib6_metric_set(rt, RTAX_MTU, mtu);
1501 rt6_mtu_change(skb->dev, mtu);
1502 }
1503 }
1504
1505 if (ndopts.nd_useropts) {
1506 struct nd_opt_hdr *p;
1507 for (p = ndopts.nd_useropts;
1508 p;
1509 p = ndisc_next_useropt(skb->dev, p,
1510 ndopts.nd_useropts_end)) {
1511 ndisc_ra_useropt(skb, p);
1512 }
1513 }
1514
1515 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1516 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1517 }
1518 out:
1519 fib6_info_release(rt);
1520 if (neigh)
1521 neigh_release(neigh);
1522 }
1523
ndisc_redirect_rcv(struct sk_buff * skb)1524 static void ndisc_redirect_rcv(struct sk_buff *skb)
1525 {
1526 u8 *hdr;
1527 struct ndisc_options ndopts;
1528 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1529 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1530 offsetof(struct rd_msg, opt));
1531
1532 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1533 switch (skb->ndisc_nodetype) {
1534 case NDISC_NODETYPE_HOST:
1535 case NDISC_NODETYPE_NODEFAULT:
1536 ND_PRINTK(2, warn,
1537 "Redirect: from host or unauthorized router\n");
1538 return;
1539 }
1540 #endif
1541
1542 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1543 ND_PRINTK(2, warn,
1544 "Redirect: source address is not link-local\n");
1545 return;
1546 }
1547
1548 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1549 return;
1550
1551 if (!ndopts.nd_opts_rh) {
1552 ip6_redirect_no_header(skb, dev_net(skb->dev),
1553 skb->dev->ifindex);
1554 return;
1555 }
1556
1557 hdr = (u8 *)ndopts.nd_opts_rh;
1558 hdr += 8;
1559 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1560 return;
1561
1562 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1563 }
1564
ndisc_fill_redirect_hdr_option(struct sk_buff * skb,struct sk_buff * orig_skb,int rd_len)1565 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1566 struct sk_buff *orig_skb,
1567 int rd_len)
1568 {
1569 u8 *opt = skb_put(skb, rd_len);
1570
1571 memset(opt, 0, 8);
1572 *(opt++) = ND_OPT_REDIRECT_HDR;
1573 *(opt++) = (rd_len >> 3);
1574 opt += 6;
1575
1576 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1577 rd_len - 8);
1578 }
1579
ndisc_send_redirect(struct sk_buff * skb,const struct in6_addr * target)1580 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1581 {
1582 struct net_device *dev = skb->dev;
1583 struct net *net = dev_net(dev);
1584 struct sock *sk = net->ipv6.ndisc_sk;
1585 int optlen = 0;
1586 struct inet_peer *peer;
1587 struct sk_buff *buff;
1588 struct rd_msg *msg;
1589 struct in6_addr saddr_buf;
1590 struct rt6_info *rt;
1591 struct dst_entry *dst;
1592 struct flowi6 fl6;
1593 int rd_len;
1594 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1595 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1596 bool ret;
1597
1598 if (netif_is_l3_master(skb->dev)) {
1599 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1600 if (!dev)
1601 return;
1602 }
1603
1604 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1605 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1606 dev->name);
1607 return;
1608 }
1609
1610 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1611 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1612 ND_PRINTK(2, warn,
1613 "Redirect: target address is not link-local unicast\n");
1614 return;
1615 }
1616
1617 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1618 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1619
1620 dst = ip6_route_output(net, NULL, &fl6);
1621 if (dst->error) {
1622 dst_release(dst);
1623 return;
1624 }
1625 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1626 if (IS_ERR(dst))
1627 return;
1628
1629 rt = (struct rt6_info *) dst;
1630
1631 if (rt->rt6i_flags & RTF_GATEWAY) {
1632 ND_PRINTK(2, warn,
1633 "Redirect: destination is not a neighbour\n");
1634 goto release;
1635 }
1636 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1637 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1638 if (peer)
1639 inet_putpeer(peer);
1640 if (!ret)
1641 goto release;
1642
1643 if (dev->addr_len) {
1644 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1645 if (!neigh) {
1646 ND_PRINTK(2, warn,
1647 "Redirect: no neigh for target address\n");
1648 goto release;
1649 }
1650
1651 read_lock_bh(&neigh->lock);
1652 if (neigh->nud_state & NUD_VALID) {
1653 memcpy(ha_buf, neigh->ha, dev->addr_len);
1654 read_unlock_bh(&neigh->lock);
1655 ha = ha_buf;
1656 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1657 ops_data_buf,
1658 &ops_data);
1659 } else
1660 read_unlock_bh(&neigh->lock);
1661
1662 neigh_release(neigh);
1663 }
1664
1665 rd_len = min_t(unsigned int,
1666 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1667 skb->len + 8);
1668 rd_len &= ~0x7;
1669 optlen += rd_len;
1670
1671 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1672 if (!buff)
1673 goto release;
1674
1675 msg = skb_put(buff, sizeof(*msg));
1676 *msg = (struct rd_msg) {
1677 .icmph = {
1678 .icmp6_type = NDISC_REDIRECT,
1679 },
1680 .target = *target,
1681 .dest = ipv6_hdr(skb)->daddr,
1682 };
1683
1684 /*
1685 * include target_address option
1686 */
1687
1688 if (ha)
1689 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1690
1691 /*
1692 * build redirect option and copy skb over to the new packet.
1693 */
1694
1695 if (rd_len)
1696 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1697
1698 skb_dst_set(buff, dst);
1699 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1700 return;
1701
1702 release:
1703 dst_release(dst);
1704 }
1705
pndisc_redo(struct sk_buff * skb)1706 static void pndisc_redo(struct sk_buff *skb)
1707 {
1708 ndisc_recv_ns(skb);
1709 kfree_skb(skb);
1710 }
1711
ndisc_is_multicast(const void * pkey)1712 static int ndisc_is_multicast(const void *pkey)
1713 {
1714 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1715 }
1716
ndisc_suppress_frag_ndisc(struct sk_buff * skb)1717 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1718 {
1719 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1720
1721 if (!idev)
1722 return true;
1723 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1724 idev->cnf.suppress_frag_ndisc) {
1725 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1726 return true;
1727 }
1728 return false;
1729 }
1730
ndisc_rcv(struct sk_buff * skb)1731 int ndisc_rcv(struct sk_buff *skb)
1732 {
1733 struct nd_msg *msg;
1734
1735 if (ndisc_suppress_frag_ndisc(skb))
1736 return 0;
1737
1738 if (skb_linearize(skb))
1739 return 0;
1740
1741 msg = (struct nd_msg *)skb_transport_header(skb);
1742
1743 __skb_push(skb, skb->data - skb_transport_header(skb));
1744
1745 if (ipv6_hdr(skb)->hop_limit != 255) {
1746 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1747 ipv6_hdr(skb)->hop_limit);
1748 return 0;
1749 }
1750
1751 if (msg->icmph.icmp6_code != 0) {
1752 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1753 msg->icmph.icmp6_code);
1754 return 0;
1755 }
1756
1757 switch (msg->icmph.icmp6_type) {
1758 case NDISC_NEIGHBOUR_SOLICITATION:
1759 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1760 ndisc_recv_ns(skb);
1761 break;
1762
1763 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1764 ndisc_recv_na(skb);
1765 break;
1766
1767 case NDISC_ROUTER_SOLICITATION:
1768 ndisc_recv_rs(skb);
1769 break;
1770
1771 case NDISC_ROUTER_ADVERTISEMENT:
1772 ndisc_router_discovery(skb);
1773 break;
1774
1775 case NDISC_REDIRECT:
1776 ndisc_redirect_rcv(skb);
1777 break;
1778 }
1779
1780 return 0;
1781 }
1782
ndisc_netdev_event(struct notifier_block * this,unsigned long event,void * ptr)1783 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1784 {
1785 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1786 struct netdev_notifier_change_info *change_info;
1787 struct net *net = dev_net(dev);
1788 struct inet6_dev *idev;
1789
1790 switch (event) {
1791 case NETDEV_CHANGEADDR:
1792 neigh_changeaddr(&nd_tbl, dev);
1793 fib6_run_gc(0, net, false);
1794 fallthrough;
1795 case NETDEV_UP:
1796 idev = in6_dev_get(dev);
1797 if (!idev)
1798 break;
1799 if (idev->cnf.ndisc_notify ||
1800 net->ipv6.devconf_all->ndisc_notify)
1801 ndisc_send_unsol_na(dev);
1802 in6_dev_put(idev);
1803 break;
1804 case NETDEV_CHANGE:
1805 change_info = ptr;
1806 if (change_info->flags_changed & IFF_NOARP)
1807 neigh_changeaddr(&nd_tbl, dev);
1808 if (!netif_carrier_ok(dev))
1809 neigh_carrier_down(&nd_tbl, dev);
1810 break;
1811 case NETDEV_DOWN:
1812 neigh_ifdown(&nd_tbl, dev);
1813 fib6_run_gc(0, net, false);
1814 break;
1815 case NETDEV_NOTIFY_PEERS:
1816 ndisc_send_unsol_na(dev);
1817 break;
1818 default:
1819 break;
1820 }
1821
1822 return NOTIFY_DONE;
1823 }
1824
1825 static struct notifier_block ndisc_netdev_notifier = {
1826 .notifier_call = ndisc_netdev_event,
1827 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1828 };
1829
1830 #ifdef CONFIG_SYSCTL
ndisc_warn_deprecated_sysctl(struct ctl_table * ctl,const char * func,const char * dev_name)1831 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1832 const char *func, const char *dev_name)
1833 {
1834 static char warncomm[TASK_COMM_LEN];
1835 static int warned;
1836 if (strcmp(warncomm, current->comm) && warned < 5) {
1837 strcpy(warncomm, current->comm);
1838 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1839 warncomm, func,
1840 dev_name, ctl->procname,
1841 dev_name, ctl->procname);
1842 warned++;
1843 }
1844 }
1845
ndisc_ifinfo_sysctl_change(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1846 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1847 size_t *lenp, loff_t *ppos)
1848 {
1849 struct net_device *dev = ctl->extra1;
1850 struct inet6_dev *idev;
1851 int ret;
1852
1853 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1854 (strcmp(ctl->procname, "base_reachable_time") == 0))
1855 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1856
1857 if (strcmp(ctl->procname, "retrans_time") == 0)
1858 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1859
1860 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1861 ret = neigh_proc_dointvec_jiffies(ctl, write,
1862 buffer, lenp, ppos);
1863
1864 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1865 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1866 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1867 buffer, lenp, ppos);
1868 else
1869 ret = -1;
1870
1871 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1872 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1873 idev->nd_parms->reachable_time =
1874 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1875 idev->tstamp = jiffies;
1876 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1877 in6_dev_put(idev);
1878 }
1879 return ret;
1880 }
1881
1882
1883 #endif
1884
ndisc_net_init(struct net * net)1885 static int __net_init ndisc_net_init(struct net *net)
1886 {
1887 struct ipv6_pinfo *np;
1888 struct sock *sk;
1889 int err;
1890
1891 err = inet_ctl_sock_create(&sk, PF_INET6,
1892 SOCK_RAW, IPPROTO_ICMPV6, net);
1893 if (err < 0) {
1894 ND_PRINTK(0, err,
1895 "NDISC: Failed to initialize the control socket (err %d)\n",
1896 err);
1897 return err;
1898 }
1899
1900 net->ipv6.ndisc_sk = sk;
1901
1902 np = inet6_sk(sk);
1903 np->hop_limit = 255;
1904 /* Do not loopback ndisc messages */
1905 np->mc_loop = 0;
1906
1907 return 0;
1908 }
1909
ndisc_net_exit(struct net * net)1910 static void __net_exit ndisc_net_exit(struct net *net)
1911 {
1912 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1913 }
1914
1915 static struct pernet_operations ndisc_net_ops = {
1916 .init = ndisc_net_init,
1917 .exit = ndisc_net_exit,
1918 };
1919
ndisc_init(void)1920 int __init ndisc_init(void)
1921 {
1922 int err;
1923
1924 err = register_pernet_subsys(&ndisc_net_ops);
1925 if (err)
1926 return err;
1927 /*
1928 * Initialize the neighbour table
1929 */
1930 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1931
1932 #ifdef CONFIG_SYSCTL
1933 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1934 ndisc_ifinfo_sysctl_change);
1935 if (err)
1936 goto out_unregister_pernet;
1937 out:
1938 #endif
1939 return err;
1940
1941 #ifdef CONFIG_SYSCTL
1942 out_unregister_pernet:
1943 unregister_pernet_subsys(&ndisc_net_ops);
1944 goto out;
1945 #endif
1946 }
1947
ndisc_late_init(void)1948 int __init ndisc_late_init(void)
1949 {
1950 return register_netdevice_notifier(&ndisc_netdev_notifier);
1951 }
1952
ndisc_late_cleanup(void)1953 void ndisc_late_cleanup(void)
1954 {
1955 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1956 }
1957
ndisc_cleanup(void)1958 void ndisc_cleanup(void)
1959 {
1960 #ifdef CONFIG_SYSCTL
1961 neigh_sysctl_unregister(&nd_tbl.parms);
1962 #endif
1963 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1964 unregister_pernet_subsys(&ndisc_net_ops);
1965 }
1966