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_RDNSS ||
200 opt->nd_opt_type == ND_OPT_DNSSL ||
201 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
202 opt->nd_opt_type == ND_OPT_PREF64 ||
203 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
204 }
205
ndisc_next_useropt(const struct net_device * dev,struct nd_opt_hdr * cur,struct nd_opt_hdr * end)206 static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
207 struct nd_opt_hdr *cur,
208 struct nd_opt_hdr *end)
209 {
210 if (!cur || !end || cur >= end)
211 return NULL;
212 do {
213 cur = ((void *)cur) + (cur->nd_opt_len << 3);
214 } while (cur < end && !ndisc_is_useropt(dev, cur));
215 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
216 }
217
ndisc_parse_options(const struct net_device * dev,u8 * opt,int opt_len,struct ndisc_options * ndopts)218 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
219 u8 *opt, int opt_len,
220 struct ndisc_options *ndopts)
221 {
222 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
223
224 if (!nd_opt || opt_len < 0 || !ndopts)
225 return NULL;
226 memset(ndopts, 0, sizeof(*ndopts));
227 while (opt_len) {
228 int l;
229 if (opt_len < sizeof(struct nd_opt_hdr))
230 return NULL;
231 l = nd_opt->nd_opt_len << 3;
232 if (opt_len < l || l == 0)
233 return NULL;
234 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
235 goto next_opt;
236 switch (nd_opt->nd_opt_type) {
237 case ND_OPT_SOURCE_LL_ADDR:
238 case ND_OPT_TARGET_LL_ADDR:
239 case ND_OPT_MTU:
240 case ND_OPT_NONCE:
241 case ND_OPT_REDIRECT_HDR:
242 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
243 ND_PRINTK(2, warn,
244 "%s: duplicated ND6 option found: type=%d\n",
245 __func__, nd_opt->nd_opt_type);
246 } else {
247 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
248 }
249 break;
250 case ND_OPT_PREFIX_INFO:
251 ndopts->nd_opts_pi_end = nd_opt;
252 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
253 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
254 break;
255 #ifdef CONFIG_IPV6_ROUTE_INFO
256 case ND_OPT_ROUTE_INFO:
257 ndopts->nd_opts_ri_end = nd_opt;
258 if (!ndopts->nd_opts_ri)
259 ndopts->nd_opts_ri = nd_opt;
260 break;
261 #endif
262 default:
263 if (ndisc_is_useropt(dev, nd_opt)) {
264 ndopts->nd_useropts_end = nd_opt;
265 if (!ndopts->nd_useropts)
266 ndopts->nd_useropts = nd_opt;
267 } else {
268 /*
269 * Unknown options must be silently ignored,
270 * to accommodate future extension to the
271 * protocol.
272 */
273 ND_PRINTK(2, notice,
274 "%s: ignored unsupported option; type=%d, len=%d\n",
275 __func__,
276 nd_opt->nd_opt_type,
277 nd_opt->nd_opt_len);
278 }
279 }
280 next_opt:
281 opt_len -= l;
282 nd_opt = ((void *)nd_opt) + l;
283 }
284 return ndopts;
285 }
286
ndisc_mc_map(const struct in6_addr * addr,char * buf,struct net_device * dev,int dir)287 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
288 {
289 switch (dev->type) {
290 case ARPHRD_ETHER:
291 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
292 case ARPHRD_FDDI:
293 ipv6_eth_mc_map(addr, buf);
294 return 0;
295 case ARPHRD_ARCNET:
296 ipv6_arcnet_mc_map(addr, buf);
297 return 0;
298 case ARPHRD_INFINIBAND:
299 ipv6_ib_mc_map(addr, dev->broadcast, buf);
300 return 0;
301 case ARPHRD_IPGRE:
302 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
303 default:
304 if (dir) {
305 memcpy(buf, dev->broadcast, dev->addr_len);
306 return 0;
307 }
308 }
309 return -EINVAL;
310 }
311 EXPORT_SYMBOL(ndisc_mc_map);
312
ndisc_hash(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)313 static u32 ndisc_hash(const void *pkey,
314 const struct net_device *dev,
315 __u32 *hash_rnd)
316 {
317 return ndisc_hashfn(pkey, dev, hash_rnd);
318 }
319
ndisc_key_eq(const struct neighbour * n,const void * pkey)320 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
321 {
322 return neigh_key_eq128(n, pkey);
323 }
324
ndisc_constructor(struct neighbour * neigh)325 static int ndisc_constructor(struct neighbour *neigh)
326 {
327 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
328 struct net_device *dev = neigh->dev;
329 struct inet6_dev *in6_dev;
330 struct neigh_parms *parms;
331 bool is_multicast = ipv6_addr_is_multicast(addr);
332
333 in6_dev = in6_dev_get(dev);
334 if (!in6_dev) {
335 return -EINVAL;
336 }
337
338 parms = in6_dev->nd_parms;
339 __neigh_parms_put(neigh->parms);
340 neigh->parms = neigh_parms_clone(parms);
341
342 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
343 if (!dev->header_ops) {
344 neigh->nud_state = NUD_NOARP;
345 neigh->ops = &ndisc_direct_ops;
346 neigh->output = neigh_direct_output;
347 } else {
348 if (is_multicast) {
349 neigh->nud_state = NUD_NOARP;
350 ndisc_mc_map(addr, neigh->ha, dev, 1);
351 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
352 neigh->nud_state = NUD_NOARP;
353 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
354 if (dev->flags&IFF_LOOPBACK)
355 neigh->type = RTN_LOCAL;
356 } else if (dev->flags&IFF_POINTOPOINT) {
357 neigh->nud_state = NUD_NOARP;
358 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
359 }
360 if (dev->header_ops->cache)
361 neigh->ops = &ndisc_hh_ops;
362 else
363 neigh->ops = &ndisc_generic_ops;
364 if (neigh->nud_state&NUD_VALID)
365 neigh->output = neigh->ops->connected_output;
366 else
367 neigh->output = neigh->ops->output;
368 }
369 in6_dev_put(in6_dev);
370 return 0;
371 }
372
pndisc_constructor(struct pneigh_entry * n)373 static int pndisc_constructor(struct pneigh_entry *n)
374 {
375 struct in6_addr *addr = (struct in6_addr *)&n->key;
376 struct in6_addr maddr;
377 struct net_device *dev = n->dev;
378
379 if (!dev || !__in6_dev_get(dev))
380 return -EINVAL;
381 addrconf_addr_solict_mult(addr, &maddr);
382 ipv6_dev_mc_inc(dev, &maddr);
383 return 0;
384 }
385
pndisc_destructor(struct pneigh_entry * n)386 static void pndisc_destructor(struct pneigh_entry *n)
387 {
388 struct in6_addr *addr = (struct in6_addr *)&n->key;
389 struct in6_addr maddr;
390 struct net_device *dev = n->dev;
391
392 if (!dev || !__in6_dev_get(dev))
393 return;
394 addrconf_addr_solict_mult(addr, &maddr);
395 ipv6_dev_mc_dec(dev, &maddr);
396 }
397
398 /* called with rtnl held */
ndisc_allow_add(const struct net_device * dev,struct netlink_ext_ack * extack)399 static bool ndisc_allow_add(const struct net_device *dev,
400 struct netlink_ext_ack *extack)
401 {
402 struct inet6_dev *idev = __in6_dev_get(dev);
403
404 if (!idev || idev->cnf.disable_ipv6) {
405 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
406 return false;
407 }
408
409 return true;
410 }
411
ndisc_alloc_skb(struct net_device * dev,int len)412 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
413 int len)
414 {
415 int hlen = LL_RESERVED_SPACE(dev);
416 int tlen = dev->needed_tailroom;
417 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
418 struct sk_buff *skb;
419
420 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
421 if (!skb) {
422 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
423 __func__);
424 return NULL;
425 }
426
427 skb->protocol = htons(ETH_P_IPV6);
428 skb->dev = dev;
429
430 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
431 skb_reset_transport_header(skb);
432
433 /* Manually assign socket ownership as we avoid calling
434 * sock_alloc_send_pskb() to bypass wmem buffer limits
435 */
436 skb_set_owner_w(skb, sk);
437
438 return skb;
439 }
440
ip6_nd_hdr(struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,int hop_limit,int len)441 static void ip6_nd_hdr(struct sk_buff *skb,
442 const struct in6_addr *saddr,
443 const struct in6_addr *daddr,
444 int hop_limit, int len)
445 {
446 struct ipv6hdr *hdr;
447 struct inet6_dev *idev;
448 unsigned tclass;
449
450 rcu_read_lock();
451 idev = __in6_dev_get(skb->dev);
452 tclass = idev ? idev->cnf.ndisc_tclass : 0;
453 rcu_read_unlock();
454
455 skb_push(skb, sizeof(*hdr));
456 skb_reset_network_header(skb);
457 hdr = ipv6_hdr(skb);
458
459 ip6_flow_hdr(hdr, tclass, 0);
460
461 hdr->payload_len = htons(len);
462 hdr->nexthdr = IPPROTO_ICMPV6;
463 hdr->hop_limit = hop_limit;
464
465 hdr->saddr = *saddr;
466 hdr->daddr = *daddr;
467 }
468
ndisc_send_skb(struct sk_buff * skb,const struct in6_addr * daddr,const struct in6_addr * saddr)469 static void ndisc_send_skb(struct sk_buff *skb,
470 const struct in6_addr *daddr,
471 const struct in6_addr *saddr)
472 {
473 struct dst_entry *dst = skb_dst(skb);
474 struct net *net = dev_net(skb->dev);
475 struct sock *sk = net->ipv6.ndisc_sk;
476 struct inet6_dev *idev;
477 int err;
478 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
479 u8 type;
480
481 type = icmp6h->icmp6_type;
482
483 if (!dst) {
484 struct flowi6 fl6;
485 int oif = skb->dev->ifindex;
486
487 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
488 dst = icmp6_dst_alloc(skb->dev, &fl6);
489 if (IS_ERR(dst)) {
490 kfree_skb(skb);
491 return;
492 }
493
494 skb_dst_set(skb, dst);
495 }
496
497 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
498 IPPROTO_ICMPV6,
499 csum_partial(icmp6h,
500 skb->len, 0));
501
502 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
503
504 rcu_read_lock();
505 idev = __in6_dev_get(dst->dev);
506 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
507
508 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
509 net, sk, skb, NULL, dst->dev,
510 dst_output);
511 if (!err) {
512 ICMP6MSGOUT_INC_STATS(net, idev, type);
513 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
514 }
515
516 rcu_read_unlock();
517 }
518
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)519 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
520 const struct in6_addr *solicited_addr,
521 bool router, bool solicited, bool override, bool inc_opt)
522 {
523 struct sk_buff *skb;
524 struct in6_addr tmpaddr;
525 struct inet6_ifaddr *ifp;
526 const struct in6_addr *src_addr;
527 struct nd_msg *msg;
528 int optlen = 0;
529
530 /* for anycast or proxy, solicited_addr != src_addr */
531 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
532 if (ifp) {
533 src_addr = solicited_addr;
534 if (ifp->flags & IFA_F_OPTIMISTIC)
535 override = false;
536 inc_opt |= ifp->idev->cnf.force_tllao;
537 in6_ifa_put(ifp);
538 } else {
539 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
540 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
541 &tmpaddr))
542 return;
543 src_addr = &tmpaddr;
544 }
545
546 if (!dev->addr_len)
547 inc_opt = false;
548 if (inc_opt)
549 optlen += ndisc_opt_addr_space(dev,
550 NDISC_NEIGHBOUR_ADVERTISEMENT);
551
552 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
553 if (!skb)
554 return;
555
556 msg = skb_put(skb, sizeof(*msg));
557 *msg = (struct nd_msg) {
558 .icmph = {
559 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
560 .icmp6_router = router,
561 .icmp6_solicited = solicited,
562 .icmp6_override = override,
563 },
564 .target = *solicited_addr,
565 };
566
567 if (inc_opt)
568 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
569 dev->dev_addr,
570 NDISC_NEIGHBOUR_ADVERTISEMENT);
571
572 ndisc_send_skb(skb, daddr, src_addr);
573 }
574
ndisc_send_unsol_na(struct net_device * dev)575 static void ndisc_send_unsol_na(struct net_device *dev)
576 {
577 struct inet6_dev *idev;
578 struct inet6_ifaddr *ifa;
579
580 idev = in6_dev_get(dev);
581 if (!idev)
582 return;
583
584 read_lock_bh(&idev->lock);
585 list_for_each_entry(ifa, &idev->addr_list, if_list) {
586 /* skip tentative addresses until dad completes */
587 if (ifa->flags & IFA_F_TENTATIVE &&
588 !(ifa->flags & IFA_F_OPTIMISTIC))
589 continue;
590
591 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
592 /*router=*/ !!idev->cnf.forwarding,
593 /*solicited=*/ false, /*override=*/ true,
594 /*inc_opt=*/ true);
595 }
596 read_unlock_bh(&idev->lock);
597
598 in6_dev_put(idev);
599 }
600
ndisc_send_ns(struct net_device * dev,const struct in6_addr * solicit,const struct in6_addr * daddr,const struct in6_addr * saddr,u64 nonce)601 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
602 const struct in6_addr *daddr, const struct in6_addr *saddr,
603 u64 nonce)
604 {
605 struct sk_buff *skb;
606 struct in6_addr addr_buf;
607 int inc_opt = dev->addr_len;
608 int optlen = 0;
609 struct nd_msg *msg;
610
611 if (!saddr) {
612 if (ipv6_get_lladdr(dev, &addr_buf,
613 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
614 return;
615 saddr = &addr_buf;
616 }
617
618 if (ipv6_addr_any(saddr))
619 inc_opt = false;
620 if (inc_opt)
621 optlen += ndisc_opt_addr_space(dev,
622 NDISC_NEIGHBOUR_SOLICITATION);
623 if (nonce != 0)
624 optlen += 8;
625
626 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
627 if (!skb)
628 return;
629
630 msg = skb_put(skb, sizeof(*msg));
631 *msg = (struct nd_msg) {
632 .icmph = {
633 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
634 },
635 .target = *solicit,
636 };
637
638 if (inc_opt)
639 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
640 dev->dev_addr,
641 NDISC_NEIGHBOUR_SOLICITATION);
642 if (nonce != 0) {
643 u8 *opt = skb_put(skb, 8);
644
645 opt[0] = ND_OPT_NONCE;
646 opt[1] = 8 >> 3;
647 memcpy(opt + 2, &nonce, 6);
648 }
649
650 ndisc_send_skb(skb, daddr, saddr);
651 }
652
ndisc_send_rs(struct net_device * dev,const struct in6_addr * saddr,const struct in6_addr * daddr)653 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
654 const struct in6_addr *daddr)
655 {
656 struct sk_buff *skb;
657 struct rs_msg *msg;
658 int send_sllao = dev->addr_len;
659 int optlen = 0;
660
661 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
662 /*
663 * According to section 2.2 of RFC 4429, we must not
664 * send router solicitations with a sllao from
665 * optimistic addresses, but we may send the solicitation
666 * if we don't include the sllao. So here we check
667 * if our address is optimistic, and if so, we
668 * suppress the inclusion of the sllao.
669 */
670 if (send_sllao) {
671 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
672 dev, 1);
673 if (ifp) {
674 if (ifp->flags & IFA_F_OPTIMISTIC) {
675 send_sllao = 0;
676 }
677 in6_ifa_put(ifp);
678 } else {
679 send_sllao = 0;
680 }
681 }
682 #endif
683 if (send_sllao)
684 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
685
686 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
687 if (!skb)
688 return;
689
690 msg = skb_put(skb, sizeof(*msg));
691 *msg = (struct rs_msg) {
692 .icmph = {
693 .icmp6_type = NDISC_ROUTER_SOLICITATION,
694 },
695 };
696
697 if (send_sllao)
698 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
699 dev->dev_addr,
700 NDISC_ROUTER_SOLICITATION);
701
702 ndisc_send_skb(skb, daddr, saddr);
703 }
704
705
ndisc_error_report(struct neighbour * neigh,struct sk_buff * skb)706 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
707 {
708 /*
709 * "The sender MUST return an ICMP
710 * destination unreachable"
711 */
712 dst_link_failure(skb);
713 kfree_skb(skb);
714 }
715
716 /* Called with locked neigh: either read or both */
717
ndisc_solicit(struct neighbour * neigh,struct sk_buff * skb)718 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
719 {
720 struct in6_addr *saddr = NULL;
721 struct in6_addr mcaddr;
722 struct net_device *dev = neigh->dev;
723 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
724 int probes = atomic_read(&neigh->probes);
725
726 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
727 dev, false, 1,
728 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
729 saddr = &ipv6_hdr(skb)->saddr;
730 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
731 if (probes < 0) {
732 if (!(neigh->nud_state & NUD_VALID)) {
733 ND_PRINTK(1, dbg,
734 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
735 __func__, target);
736 }
737 ndisc_send_ns(dev, target, target, saddr, 0);
738 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
739 neigh_app_ns(neigh);
740 } else {
741 addrconf_addr_solict_mult(target, &mcaddr);
742 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
743 }
744 }
745
pndisc_is_router(const void * pkey,struct net_device * dev)746 static int pndisc_is_router(const void *pkey,
747 struct net_device *dev)
748 {
749 struct pneigh_entry *n;
750 int ret = -1;
751
752 read_lock_bh(&nd_tbl.lock);
753 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
754 if (n)
755 ret = !!(n->flags & NTF_ROUTER);
756 read_unlock_bh(&nd_tbl.lock);
757
758 return ret;
759 }
760
ndisc_update(const struct net_device * dev,struct neighbour * neigh,const u8 * lladdr,u8 new,u32 flags,u8 icmp6_type,struct ndisc_options * ndopts)761 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
762 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
763 struct ndisc_options *ndopts)
764 {
765 neigh_update(neigh, lladdr, new, flags, 0);
766 /* report ndisc ops about neighbour update */
767 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
768 }
769
ndisc_recv_ns(struct sk_buff * skb)770 static void ndisc_recv_ns(struct sk_buff *skb)
771 {
772 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
773 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
774 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
775 u8 *lladdr = NULL;
776 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
777 offsetof(struct nd_msg, opt));
778 struct ndisc_options ndopts;
779 struct net_device *dev = skb->dev;
780 struct inet6_ifaddr *ifp;
781 struct inet6_dev *idev = NULL;
782 struct neighbour *neigh;
783 int dad = ipv6_addr_any(saddr);
784 bool inc;
785 int is_router = -1;
786 u64 nonce = 0;
787
788 if (skb->len < sizeof(struct nd_msg)) {
789 ND_PRINTK(2, warn, "NS: packet too short\n");
790 return;
791 }
792
793 if (ipv6_addr_is_multicast(&msg->target)) {
794 ND_PRINTK(2, warn, "NS: multicast target address\n");
795 return;
796 }
797
798 /*
799 * RFC2461 7.1.1:
800 * DAD has to be destined for solicited node multicast address.
801 */
802 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
803 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
804 return;
805 }
806
807 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
808 ND_PRINTK(2, warn, "NS: invalid ND options\n");
809 return;
810 }
811
812 if (ndopts.nd_opts_src_lladdr) {
813 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
814 if (!lladdr) {
815 ND_PRINTK(2, warn,
816 "NS: invalid link-layer address length\n");
817 return;
818 }
819
820 /* RFC2461 7.1.1:
821 * If the IP source address is the unspecified address,
822 * there MUST NOT be source link-layer address option
823 * in the message.
824 */
825 if (dad) {
826 ND_PRINTK(2, warn,
827 "NS: bad DAD packet (link-layer address option)\n");
828 return;
829 }
830 }
831 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
832 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
833
834 inc = ipv6_addr_is_multicast(daddr);
835
836 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
837 if (ifp) {
838 have_ifp:
839 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
840 if (dad) {
841 if (nonce != 0 && ifp->dad_nonce == nonce) {
842 u8 *np = (u8 *)&nonce;
843 /* Matching nonce if looped back */
844 ND_PRINTK(2, notice,
845 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
846 ifp->idev->dev->name,
847 &ifp->addr, np);
848 goto out;
849 }
850 /*
851 * We are colliding with another node
852 * who is doing DAD
853 * so fail our DAD process
854 */
855 addrconf_dad_failure(skb, ifp);
856 return;
857 } else {
858 /*
859 * This is not a dad solicitation.
860 * If we are an optimistic node,
861 * we should respond.
862 * Otherwise, we should ignore it.
863 */
864 if (!(ifp->flags & IFA_F_OPTIMISTIC))
865 goto out;
866 }
867 }
868
869 idev = ifp->idev;
870 } else {
871 struct net *net = dev_net(dev);
872
873 /* perhaps an address on the master device */
874 if (netif_is_l3_slave(dev)) {
875 struct net_device *mdev;
876
877 mdev = netdev_master_upper_dev_get_rcu(dev);
878 if (mdev) {
879 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
880 if (ifp)
881 goto have_ifp;
882 }
883 }
884
885 idev = in6_dev_get(dev);
886 if (!idev) {
887 /* XXX: count this drop? */
888 return;
889 }
890
891 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
892 (idev->cnf.forwarding &&
893 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
894 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
895 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
896 skb->pkt_type != PACKET_HOST &&
897 inc &&
898 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
899 /*
900 * for anycast or proxy,
901 * sender should delay its response
902 * by a random time between 0 and
903 * MAX_ANYCAST_DELAY_TIME seconds.
904 * (RFC2461) -- yoshfuji
905 */
906 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
907 if (n)
908 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
909 goto out;
910 }
911 } else
912 goto out;
913 }
914
915 if (is_router < 0)
916 is_router = idev->cnf.forwarding;
917
918 if (dad) {
919 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
920 !!is_router, false, (ifp != NULL), true);
921 goto out;
922 }
923
924 if (inc)
925 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
926 else
927 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
928
929 /*
930 * update / create cache entry
931 * for the source address
932 */
933 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
934 !inc || lladdr || !dev->addr_len);
935 if (neigh)
936 ndisc_update(dev, neigh, lladdr, NUD_STALE,
937 NEIGH_UPDATE_F_WEAK_OVERRIDE|
938 NEIGH_UPDATE_F_OVERRIDE,
939 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
940 if (neigh || !dev->header_ops) {
941 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
942 true, (ifp != NULL && inc), inc);
943 if (neigh)
944 neigh_release(neigh);
945 }
946
947 out:
948 if (ifp)
949 in6_ifa_put(ifp);
950 else
951 in6_dev_put(idev);
952 }
953
ndisc_recv_na(struct sk_buff * skb)954 static void ndisc_recv_na(struct sk_buff *skb)
955 {
956 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
957 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
958 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
959 u8 *lladdr = NULL;
960 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
961 offsetof(struct nd_msg, opt));
962 struct ndisc_options ndopts;
963 struct net_device *dev = skb->dev;
964 struct inet6_dev *idev = __in6_dev_get(dev);
965 struct inet6_ifaddr *ifp;
966 struct neighbour *neigh;
967
968 if (skb->len < sizeof(struct nd_msg)) {
969 ND_PRINTK(2, warn, "NA: packet too short\n");
970 return;
971 }
972
973 if (ipv6_addr_is_multicast(&msg->target)) {
974 ND_PRINTK(2, warn, "NA: target address is multicast\n");
975 return;
976 }
977
978 if (ipv6_addr_is_multicast(daddr) &&
979 msg->icmph.icmp6_solicited) {
980 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
981 return;
982 }
983
984 /* For some 802.11 wireless deployments (and possibly other networks),
985 * there will be a NA proxy and unsolicitd packets are attacks
986 * and thus should not be accepted.
987 */
988 if (!msg->icmph.icmp6_solicited && idev &&
989 idev->cnf.drop_unsolicited_na)
990 return;
991
992 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
993 ND_PRINTK(2, warn, "NS: invalid ND option\n");
994 return;
995 }
996 if (ndopts.nd_opts_tgt_lladdr) {
997 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
998 if (!lladdr) {
999 ND_PRINTK(2, warn,
1000 "NA: invalid link-layer address length\n");
1001 return;
1002 }
1003 }
1004 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1005 if (ifp) {
1006 if (skb->pkt_type != PACKET_LOOPBACK
1007 && (ifp->flags & IFA_F_TENTATIVE)) {
1008 addrconf_dad_failure(skb, ifp);
1009 return;
1010 }
1011 /* What should we make now? The advertisement
1012 is invalid, but ndisc specs say nothing
1013 about it. It could be misconfiguration, or
1014 an smart proxy agent tries to help us :-)
1015
1016 We should not print the error if NA has been
1017 received from loopback - it is just our own
1018 unsolicited advertisement.
1019 */
1020 if (skb->pkt_type != PACKET_LOOPBACK)
1021 ND_PRINTK(1, warn,
1022 "NA: %pM advertised our address %pI6c on %s!\n",
1023 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1024 in6_ifa_put(ifp);
1025 return;
1026 }
1027 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1028
1029 if (neigh) {
1030 u8 old_flags = neigh->flags;
1031 struct net *net = dev_net(dev);
1032
1033 if (neigh->nud_state & NUD_FAILED)
1034 goto out;
1035
1036 /*
1037 * Don't update the neighbor cache entry on a proxy NA from
1038 * ourselves because either the proxied node is off link or it
1039 * has already sent a NA to us.
1040 */
1041 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1042 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1043 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1044 /* XXX: idev->cnf.proxy_ndp */
1045 goto out;
1046 }
1047
1048 ndisc_update(dev, neigh, lladdr,
1049 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1050 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1051 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1052 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1053 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1054 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1055
1056 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1057 /*
1058 * Change: router to host
1059 */
1060 rt6_clean_tohost(dev_net(dev), saddr);
1061 }
1062
1063 out:
1064 neigh_release(neigh);
1065 }
1066 }
1067
ndisc_recv_rs(struct sk_buff * skb)1068 static void ndisc_recv_rs(struct sk_buff *skb)
1069 {
1070 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1071 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1072 struct neighbour *neigh;
1073 struct inet6_dev *idev;
1074 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1075 struct ndisc_options ndopts;
1076 u8 *lladdr = NULL;
1077
1078 if (skb->len < sizeof(*rs_msg))
1079 return;
1080
1081 idev = __in6_dev_get(skb->dev);
1082 if (!idev) {
1083 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1084 return;
1085 }
1086
1087 /* Don't accept RS if we're not in router mode */
1088 if (!idev->cnf.forwarding)
1089 goto out;
1090
1091 /*
1092 * Don't update NCE if src = ::;
1093 * this implies that the source node has no ip address assigned yet.
1094 */
1095 if (ipv6_addr_any(saddr))
1096 goto out;
1097
1098 /* Parse ND options */
1099 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1100 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1101 goto out;
1102 }
1103
1104 if (ndopts.nd_opts_src_lladdr) {
1105 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1106 skb->dev);
1107 if (!lladdr)
1108 goto out;
1109 }
1110
1111 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1112 if (neigh) {
1113 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1114 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1115 NEIGH_UPDATE_F_OVERRIDE|
1116 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1117 NDISC_ROUTER_SOLICITATION, &ndopts);
1118 neigh_release(neigh);
1119 }
1120 out:
1121 return;
1122 }
1123
ndisc_ra_useropt(struct sk_buff * ra,struct nd_opt_hdr * opt)1124 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1125 {
1126 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1127 struct sk_buff *skb;
1128 struct nlmsghdr *nlh;
1129 struct nduseroptmsg *ndmsg;
1130 struct net *net = dev_net(ra->dev);
1131 int err;
1132 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1133 + (opt->nd_opt_len << 3));
1134 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1135
1136 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1137 if (!skb) {
1138 err = -ENOBUFS;
1139 goto errout;
1140 }
1141
1142 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1143 if (!nlh) {
1144 goto nla_put_failure;
1145 }
1146
1147 ndmsg = nlmsg_data(nlh);
1148 ndmsg->nduseropt_family = AF_INET6;
1149 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1150 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1151 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1152 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1153
1154 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1155
1156 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1157 goto nla_put_failure;
1158 nlmsg_end(skb, nlh);
1159
1160 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1161 return;
1162
1163 nla_put_failure:
1164 nlmsg_free(skb);
1165 err = -EMSGSIZE;
1166 errout:
1167 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1168 }
1169
ndisc_router_discovery(struct sk_buff * skb)1170 static void ndisc_router_discovery(struct sk_buff *skb)
1171 {
1172 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1173 struct neighbour *neigh = NULL;
1174 struct inet6_dev *in6_dev;
1175 struct fib6_info *rt = NULL;
1176 u32 defrtr_usr_metric;
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 /* Set default route metric as specified by user */
1308 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1309 /* delete the route if lifetime is 0 or if metric needs change */
1310 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1311 ip6_del_rt(net, rt, false);
1312 rt = NULL;
1313 }
1314
1315 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
1316 rt, lifetime, defrtr_usr_metric, skb->dev->name);
1317 if (!rt && lifetime) {
1318 ND_PRINTK(3, info, "RA: adding default router\n");
1319
1320 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1321 skb->dev, pref, defrtr_usr_metric);
1322 if (!rt) {
1323 ND_PRINTK(0, err,
1324 "RA: %s failed to add default route\n",
1325 __func__);
1326 return;
1327 }
1328
1329 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1330 rt->fib6_nh->fib_nh_dev, NULL,
1331 &ipv6_hdr(skb)->saddr);
1332 if (!neigh) {
1333 ND_PRINTK(0, err,
1334 "RA: %s got default router without neighbour\n",
1335 __func__);
1336 fib6_info_release(rt);
1337 return;
1338 }
1339 neigh->flags |= NTF_ROUTER;
1340 } else if (rt) {
1341 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1342 }
1343
1344 if (rt)
1345 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1346 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1347 ra_msg->icmph.icmp6_hop_limit) {
1348 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1349 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1350 fib6_metric_set(rt, RTAX_HOPLIMIT,
1351 ra_msg->icmph.icmp6_hop_limit);
1352 } else {
1353 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1354 }
1355 }
1356
1357 skip_defrtr:
1358
1359 /*
1360 * Update Reachable Time and Retrans Timer
1361 */
1362
1363 if (in6_dev->nd_parms) {
1364 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1365
1366 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1367 rtime = (rtime*HZ)/1000;
1368 if (rtime < HZ/100)
1369 rtime = HZ/100;
1370 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1371 in6_dev->tstamp = jiffies;
1372 send_ifinfo_notify = true;
1373 }
1374
1375 rtime = ntohl(ra_msg->reachable_time);
1376 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1377 rtime = (rtime*HZ)/1000;
1378
1379 if (rtime < HZ/10)
1380 rtime = HZ/10;
1381
1382 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1383 NEIGH_VAR_SET(in6_dev->nd_parms,
1384 BASE_REACHABLE_TIME, rtime);
1385 NEIGH_VAR_SET(in6_dev->nd_parms,
1386 GC_STALETIME, 3 * rtime);
1387 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1388 in6_dev->tstamp = jiffies;
1389 send_ifinfo_notify = true;
1390 }
1391 }
1392 }
1393
1394 skip_linkparms:
1395
1396 /*
1397 * Process options.
1398 */
1399
1400 if (!neigh)
1401 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1402 skb->dev, 1);
1403 if (neigh) {
1404 u8 *lladdr = NULL;
1405 if (ndopts.nd_opts_src_lladdr) {
1406 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1407 skb->dev);
1408 if (!lladdr) {
1409 ND_PRINTK(2, warn,
1410 "RA: invalid link-layer address length\n");
1411 goto out;
1412 }
1413 }
1414 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1415 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1416 NEIGH_UPDATE_F_OVERRIDE|
1417 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1418 NEIGH_UPDATE_F_ISROUTER,
1419 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1420 }
1421
1422 if (!ipv6_accept_ra(in6_dev)) {
1423 ND_PRINTK(2, info,
1424 "RA: %s, accept_ra is false for dev: %s\n",
1425 __func__, skb->dev->name);
1426 goto out;
1427 }
1428
1429 #ifdef CONFIG_IPV6_ROUTE_INFO
1430 if (!in6_dev->cnf.accept_ra_from_local &&
1431 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1432 in6_dev->dev, 0)) {
1433 ND_PRINTK(2, info,
1434 "RA from local address detected on dev: %s: router info ignored.\n",
1435 skb->dev->name);
1436 goto skip_routeinfo;
1437 }
1438
1439 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1440 struct nd_opt_hdr *p;
1441 for (p = ndopts.nd_opts_ri;
1442 p;
1443 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1444 struct route_info *ri = (struct route_info *)p;
1445 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1446 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1447 ri->prefix_len == 0)
1448 continue;
1449 #endif
1450 if (ri->prefix_len == 0 &&
1451 !in6_dev->cnf.accept_ra_defrtr)
1452 continue;
1453 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1454 continue;
1455 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1456 continue;
1457 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1458 &ipv6_hdr(skb)->saddr);
1459 }
1460 }
1461
1462 skip_routeinfo:
1463 #endif
1464
1465 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1466 /* skip link-specific ndopts from interior routers */
1467 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1468 ND_PRINTK(2, info,
1469 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1470 __func__, skb->dev->name);
1471 goto out;
1472 }
1473 #endif
1474
1475 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1476 struct nd_opt_hdr *p;
1477 for (p = ndopts.nd_opts_pi;
1478 p;
1479 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1480 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1481 (p->nd_opt_len) << 3,
1482 ndopts.nd_opts_src_lladdr != NULL);
1483 }
1484 }
1485
1486 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1487 __be32 n;
1488 u32 mtu;
1489
1490 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1491 mtu = ntohl(n);
1492
1493 if (in6_dev->ra_mtu != mtu) {
1494 in6_dev->ra_mtu = mtu;
1495 send_ifinfo_notify = true;
1496 }
1497
1498 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1499 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1500 } else if (in6_dev->cnf.mtu6 != mtu) {
1501 in6_dev->cnf.mtu6 = mtu;
1502 fib6_metric_set(rt, RTAX_MTU, mtu);
1503 rt6_mtu_change(skb->dev, mtu);
1504 }
1505 }
1506
1507 if (ndopts.nd_useropts) {
1508 struct nd_opt_hdr *p;
1509 for (p = ndopts.nd_useropts;
1510 p;
1511 p = ndisc_next_useropt(skb->dev, p,
1512 ndopts.nd_useropts_end)) {
1513 ndisc_ra_useropt(skb, p);
1514 }
1515 }
1516
1517 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1518 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1519 }
1520 out:
1521 /* Send a notify if RA changed managed/otherconf flags or
1522 * timer settings or ra_mtu value
1523 */
1524 if (send_ifinfo_notify)
1525 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1526
1527 fib6_info_release(rt);
1528 if (neigh)
1529 neigh_release(neigh);
1530 }
1531
ndisc_redirect_rcv(struct sk_buff * skb)1532 static void ndisc_redirect_rcv(struct sk_buff *skb)
1533 {
1534 u8 *hdr;
1535 struct ndisc_options ndopts;
1536 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1537 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1538 offsetof(struct rd_msg, opt));
1539
1540 #ifdef CONFIG_IPV6_NDISC_NODETYPE
1541 switch (skb->ndisc_nodetype) {
1542 case NDISC_NODETYPE_HOST:
1543 case NDISC_NODETYPE_NODEFAULT:
1544 ND_PRINTK(2, warn,
1545 "Redirect: from host or unauthorized router\n");
1546 return;
1547 }
1548 #endif
1549
1550 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1551 ND_PRINTK(2, warn,
1552 "Redirect: source address is not link-local\n");
1553 return;
1554 }
1555
1556 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1557 return;
1558
1559 if (!ndopts.nd_opts_rh) {
1560 ip6_redirect_no_header(skb, dev_net(skb->dev),
1561 skb->dev->ifindex);
1562 return;
1563 }
1564
1565 hdr = (u8 *)ndopts.nd_opts_rh;
1566 hdr += 8;
1567 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1568 return;
1569
1570 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1571 }
1572
ndisc_fill_redirect_hdr_option(struct sk_buff * skb,struct sk_buff * orig_skb,int rd_len)1573 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1574 struct sk_buff *orig_skb,
1575 int rd_len)
1576 {
1577 u8 *opt = skb_put(skb, rd_len);
1578
1579 memset(opt, 0, 8);
1580 *(opt++) = ND_OPT_REDIRECT_HDR;
1581 *(opt++) = (rd_len >> 3);
1582 opt += 6;
1583
1584 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1585 rd_len - 8);
1586 }
1587
ndisc_send_redirect(struct sk_buff * skb,const struct in6_addr * target)1588 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1589 {
1590 struct net_device *dev = skb->dev;
1591 struct net *net = dev_net(dev);
1592 struct sock *sk = net->ipv6.ndisc_sk;
1593 int optlen = 0;
1594 struct inet_peer *peer;
1595 struct sk_buff *buff;
1596 struct rd_msg *msg;
1597 struct in6_addr saddr_buf;
1598 struct rt6_info *rt;
1599 struct dst_entry *dst;
1600 struct flowi6 fl6;
1601 int rd_len;
1602 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1603 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1604 bool ret;
1605
1606 if (netif_is_l3_master(skb->dev)) {
1607 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1608 if (!dev)
1609 return;
1610 }
1611
1612 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1613 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1614 dev->name);
1615 return;
1616 }
1617
1618 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1619 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1620 ND_PRINTK(2, warn,
1621 "Redirect: target address is not link-local unicast\n");
1622 return;
1623 }
1624
1625 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1626 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1627
1628 dst = ip6_route_output(net, NULL, &fl6);
1629 if (dst->error) {
1630 dst_release(dst);
1631 return;
1632 }
1633 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1634 if (IS_ERR(dst))
1635 return;
1636
1637 rt = (struct rt6_info *) dst;
1638
1639 if (rt->rt6i_flags & RTF_GATEWAY) {
1640 ND_PRINTK(2, warn,
1641 "Redirect: destination is not a neighbour\n");
1642 goto release;
1643 }
1644 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1645 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1646 if (peer)
1647 inet_putpeer(peer);
1648 if (!ret)
1649 goto release;
1650
1651 if (dev->addr_len) {
1652 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1653 if (!neigh) {
1654 ND_PRINTK(2, warn,
1655 "Redirect: no neigh for target address\n");
1656 goto release;
1657 }
1658
1659 read_lock_bh(&neigh->lock);
1660 if (neigh->nud_state & NUD_VALID) {
1661 memcpy(ha_buf, neigh->ha, dev->addr_len);
1662 read_unlock_bh(&neigh->lock);
1663 ha = ha_buf;
1664 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1665 ops_data_buf,
1666 &ops_data);
1667 } else
1668 read_unlock_bh(&neigh->lock);
1669
1670 neigh_release(neigh);
1671 }
1672
1673 rd_len = min_t(unsigned int,
1674 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1675 skb->len + 8);
1676 rd_len &= ~0x7;
1677 optlen += rd_len;
1678
1679 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1680 if (!buff)
1681 goto release;
1682
1683 msg = skb_put(buff, sizeof(*msg));
1684 *msg = (struct rd_msg) {
1685 .icmph = {
1686 .icmp6_type = NDISC_REDIRECT,
1687 },
1688 .target = *target,
1689 .dest = ipv6_hdr(skb)->daddr,
1690 };
1691
1692 /*
1693 * include target_address option
1694 */
1695
1696 if (ha)
1697 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1698
1699 /*
1700 * build redirect option and copy skb over to the new packet.
1701 */
1702
1703 if (rd_len)
1704 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1705
1706 skb_dst_set(buff, dst);
1707 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1708 return;
1709
1710 release:
1711 dst_release(dst);
1712 }
1713
pndisc_redo(struct sk_buff * skb)1714 static void pndisc_redo(struct sk_buff *skb)
1715 {
1716 ndisc_recv_ns(skb);
1717 kfree_skb(skb);
1718 }
1719
ndisc_is_multicast(const void * pkey)1720 static int ndisc_is_multicast(const void *pkey)
1721 {
1722 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1723 }
1724
ndisc_suppress_frag_ndisc(struct sk_buff * skb)1725 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1726 {
1727 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1728
1729 if (!idev)
1730 return true;
1731 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1732 idev->cnf.suppress_frag_ndisc) {
1733 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1734 return true;
1735 }
1736 return false;
1737 }
1738
ndisc_rcv(struct sk_buff * skb)1739 int ndisc_rcv(struct sk_buff *skb)
1740 {
1741 struct nd_msg *msg;
1742
1743 if (ndisc_suppress_frag_ndisc(skb))
1744 return 0;
1745
1746 if (skb_linearize(skb))
1747 return 0;
1748
1749 msg = (struct nd_msg *)skb_transport_header(skb);
1750
1751 __skb_push(skb, skb->data - skb_transport_header(skb));
1752
1753 if (ipv6_hdr(skb)->hop_limit != 255) {
1754 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1755 ipv6_hdr(skb)->hop_limit);
1756 return 0;
1757 }
1758
1759 if (msg->icmph.icmp6_code != 0) {
1760 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1761 msg->icmph.icmp6_code);
1762 return 0;
1763 }
1764
1765 switch (msg->icmph.icmp6_type) {
1766 case NDISC_NEIGHBOUR_SOLICITATION:
1767 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1768 ndisc_recv_ns(skb);
1769 break;
1770
1771 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1772 ndisc_recv_na(skb);
1773 break;
1774
1775 case NDISC_ROUTER_SOLICITATION:
1776 ndisc_recv_rs(skb);
1777 break;
1778
1779 case NDISC_ROUTER_ADVERTISEMENT:
1780 ndisc_router_discovery(skb);
1781 break;
1782
1783 case NDISC_REDIRECT:
1784 ndisc_redirect_rcv(skb);
1785 break;
1786 }
1787
1788 return 0;
1789 }
1790
ndisc_netdev_event(struct notifier_block * this,unsigned long event,void * ptr)1791 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1792 {
1793 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1794 struct netdev_notifier_change_info *change_info;
1795 struct net *net = dev_net(dev);
1796 struct inet6_dev *idev;
1797
1798 switch (event) {
1799 case NETDEV_CHANGEADDR:
1800 neigh_changeaddr(&nd_tbl, dev);
1801 fib6_run_gc(0, net, false);
1802 fallthrough;
1803 case NETDEV_UP:
1804 idev = in6_dev_get(dev);
1805 if (!idev)
1806 break;
1807 if (idev->cnf.ndisc_notify ||
1808 net->ipv6.devconf_all->ndisc_notify)
1809 ndisc_send_unsol_na(dev);
1810 in6_dev_put(idev);
1811 break;
1812 case NETDEV_CHANGE:
1813 change_info = ptr;
1814 if (change_info->flags_changed & IFF_NOARP)
1815 neigh_changeaddr(&nd_tbl, dev);
1816 if (!netif_carrier_ok(dev))
1817 neigh_carrier_down(&nd_tbl, dev);
1818 break;
1819 case NETDEV_DOWN:
1820 neigh_ifdown(&nd_tbl, dev);
1821 fib6_run_gc(0, net, false);
1822 break;
1823 case NETDEV_NOTIFY_PEERS:
1824 ndisc_send_unsol_na(dev);
1825 break;
1826 default:
1827 break;
1828 }
1829
1830 return NOTIFY_DONE;
1831 }
1832
1833 static struct notifier_block ndisc_netdev_notifier = {
1834 .notifier_call = ndisc_netdev_event,
1835 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1836 };
1837
1838 #ifdef CONFIG_SYSCTL
ndisc_warn_deprecated_sysctl(struct ctl_table * ctl,const char * func,const char * dev_name)1839 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1840 const char *func, const char *dev_name)
1841 {
1842 static char warncomm[TASK_COMM_LEN];
1843 static int warned;
1844 if (strcmp(warncomm, current->comm) && warned < 5) {
1845 strcpy(warncomm, current->comm);
1846 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1847 warncomm, func,
1848 dev_name, ctl->procname,
1849 dev_name, ctl->procname);
1850 warned++;
1851 }
1852 }
1853
ndisc_ifinfo_sysctl_change(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1854 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1855 size_t *lenp, loff_t *ppos)
1856 {
1857 struct net_device *dev = ctl->extra1;
1858 struct inet6_dev *idev;
1859 int ret;
1860
1861 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1862 (strcmp(ctl->procname, "base_reachable_time") == 0))
1863 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1864
1865 if (strcmp(ctl->procname, "retrans_time") == 0)
1866 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1867
1868 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1869 ret = neigh_proc_dointvec_jiffies(ctl, write,
1870 buffer, lenp, ppos);
1871
1872 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1873 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1874 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1875 buffer, lenp, ppos);
1876 else
1877 ret = -1;
1878
1879 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1880 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1881 idev->nd_parms->reachable_time =
1882 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1883 idev->tstamp = jiffies;
1884 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1885 in6_dev_put(idev);
1886 }
1887 return ret;
1888 }
1889
1890
1891 #endif
1892
ndisc_net_init(struct net * net)1893 static int __net_init ndisc_net_init(struct net *net)
1894 {
1895 struct ipv6_pinfo *np;
1896 struct sock *sk;
1897 int err;
1898
1899 err = inet_ctl_sock_create(&sk, PF_INET6,
1900 SOCK_RAW, IPPROTO_ICMPV6, net);
1901 if (err < 0) {
1902 ND_PRINTK(0, err,
1903 "NDISC: Failed to initialize the control socket (err %d)\n",
1904 err);
1905 return err;
1906 }
1907
1908 net->ipv6.ndisc_sk = sk;
1909
1910 np = inet6_sk(sk);
1911 np->hop_limit = 255;
1912 /* Do not loopback ndisc messages */
1913 np->mc_loop = 0;
1914
1915 return 0;
1916 }
1917
ndisc_net_exit(struct net * net)1918 static void __net_exit ndisc_net_exit(struct net *net)
1919 {
1920 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1921 }
1922
1923 static struct pernet_operations ndisc_net_ops = {
1924 .init = ndisc_net_init,
1925 .exit = ndisc_net_exit,
1926 };
1927
ndisc_init(void)1928 int __init ndisc_init(void)
1929 {
1930 int err;
1931
1932 err = register_pernet_subsys(&ndisc_net_ops);
1933 if (err)
1934 return err;
1935 /*
1936 * Initialize the neighbour table
1937 */
1938 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1939
1940 #ifdef CONFIG_SYSCTL
1941 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1942 ndisc_ifinfo_sysctl_change);
1943 if (err)
1944 goto out_unregister_pernet;
1945 out:
1946 #endif
1947 return err;
1948
1949 #ifdef CONFIG_SYSCTL
1950 out_unregister_pernet:
1951 unregister_pernet_subsys(&ndisc_net_ops);
1952 goto out;
1953 #endif
1954 }
1955
ndisc_late_init(void)1956 int __init ndisc_late_init(void)
1957 {
1958 return register_netdevice_notifier(&ndisc_netdev_notifier);
1959 }
1960
ndisc_late_cleanup(void)1961 void ndisc_late_cleanup(void)
1962 {
1963 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1964 }
1965
ndisc_cleanup(void)1966 void ndisc_cleanup(void)
1967 {
1968 #ifdef CONFIG_SYSCTL
1969 neigh_sysctl_unregister(&nd_tbl.parms);
1970 #endif
1971 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1972 unregister_pernet_subsys(&ndisc_net_ops);
1973 }
1974
