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_INTERVAL_PROBE_TIME_MS] = 5 * HZ, |
132 | [NEIGH_VAR_GC_STALETIME] = 60 * HZ, |
133 | [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, |
134 | [NEIGH_VAR_PROXY_QLEN] = 64, |
135 | [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, |
136 | [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, |
137 | }, |
138 | }, |
139 | .gc_interval = 30 * HZ, |
140 | .gc_thresh1 = 128, |
141 | .gc_thresh2 = 512, |
142 | .gc_thresh3 = 1024, |
143 | }; |
144 | EXPORT_SYMBOL_GPL(nd_tbl); |
145 | |
146 | void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data, |
147 | int data_len, int pad) |
148 | { |
149 | int space = __ndisc_opt_addr_space(addr_len: data_len, pad); |
150 | u8 *opt = skb_put(skb, len: space); |
151 | |
152 | opt[0] = type; |
153 | opt[1] = space>>3; |
154 | |
155 | memset(opt + 2, 0, pad); |
156 | opt += pad; |
157 | space -= pad; |
158 | |
159 | memcpy(opt+2, data, data_len); |
160 | data_len += 2; |
161 | opt += data_len; |
162 | space -= data_len; |
163 | if (space > 0) |
164 | memset(opt, 0, space); |
165 | } |
166 | EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option); |
167 | |
168 | static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type, |
169 | const void *data, u8 icmp6_type) |
170 | { |
171 | __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len, |
172 | ndisc_addr_option_pad(type: skb->dev->type)); |
173 | ndisc_ops_fill_addr_option(dev: skb->dev, skb, icmp6_type); |
174 | } |
175 | |
176 | static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb, |
177 | void *ha, |
178 | const u8 *ops_data) |
179 | { |
180 | ndisc_fill_addr_option(skb, type: ND_OPT_TARGET_LL_ADDR, data: ha, NDISC_REDIRECT); |
181 | ndisc_ops_fill_redirect_addr_option(dev: skb->dev, skb, ha: ops_data); |
182 | } |
183 | |
184 | static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, |
185 | struct nd_opt_hdr *end) |
186 | { |
187 | int type; |
188 | if (!cur || !end || cur >= end) |
189 | return NULL; |
190 | type = cur->nd_opt_type; |
191 | do { |
192 | cur = ((void *)cur) + (cur->nd_opt_len << 3); |
193 | } while (cur < end && cur->nd_opt_type != type); |
194 | return cur <= end && cur->nd_opt_type == type ? cur : NULL; |
195 | } |
196 | |
197 | static inline int ndisc_is_useropt(const struct net_device *dev, |
198 | struct nd_opt_hdr *opt) |
199 | { |
200 | return opt->nd_opt_type == ND_OPT_PREFIX_INFO || |
201 | opt->nd_opt_type == ND_OPT_RDNSS || |
202 | opt->nd_opt_type == ND_OPT_DNSSL || |
203 | opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL || |
204 | opt->nd_opt_type == ND_OPT_PREF64 || |
205 | ndisc_ops_is_useropt(dev, nd_opt_type: opt->nd_opt_type); |
206 | } |
207 | |
208 | static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev, |
209 | struct nd_opt_hdr *cur, |
210 | struct nd_opt_hdr *end) |
211 | { |
212 | if (!cur || !end || cur >= end) |
213 | return NULL; |
214 | do { |
215 | cur = ((void *)cur) + (cur->nd_opt_len << 3); |
216 | } while (cur < end && !ndisc_is_useropt(dev, opt: cur)); |
217 | return cur <= end && ndisc_is_useropt(dev, opt: cur) ? cur : NULL; |
218 | } |
219 | |
220 | struct ndisc_options *ndisc_parse_options(const struct net_device *dev, |
221 | u8 *opt, int opt_len, |
222 | struct ndisc_options *ndopts) |
223 | { |
224 | struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; |
225 | |
226 | if (!nd_opt || opt_len < 0 || !ndopts) |
227 | return NULL; |
228 | memset(ndopts, 0, sizeof(*ndopts)); |
229 | while (opt_len) { |
230 | int l; |
231 | if (opt_len < sizeof(struct nd_opt_hdr)) |
232 | return NULL; |
233 | l = nd_opt->nd_opt_len << 3; |
234 | if (opt_len < l || l == 0) |
235 | return NULL; |
236 | if (ndisc_ops_parse_options(dev, nd_opt, ndopts)) |
237 | goto next_opt; |
238 | switch (nd_opt->nd_opt_type) { |
239 | case ND_OPT_SOURCE_LL_ADDR: |
240 | case ND_OPT_TARGET_LL_ADDR: |
241 | case ND_OPT_MTU: |
242 | case ND_OPT_NONCE: |
243 | case ND_OPT_REDIRECT_HDR: |
244 | if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { |
245 | ND_PRINTK(2, warn, |
246 | "%s: duplicated ND6 option found: type=%d\n" , |
247 | __func__, nd_opt->nd_opt_type); |
248 | } else { |
249 | ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; |
250 | } |
251 | break; |
252 | case ND_OPT_PREFIX_INFO: |
253 | ndopts->nd_opts_pi_end = nd_opt; |
254 | if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) |
255 | ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; |
256 | break; |
257 | #ifdef CONFIG_IPV6_ROUTE_INFO |
258 | case ND_OPT_ROUTE_INFO: |
259 | ndopts->nd_opts_ri_end = nd_opt; |
260 | if (!ndopts->nd_opts_ri) |
261 | ndopts->nd_opts_ri = nd_opt; |
262 | break; |
263 | #endif |
264 | default: |
265 | if (ndisc_is_useropt(dev, opt: nd_opt)) { |
266 | ndopts->nd_useropts_end = nd_opt; |
267 | if (!ndopts->nd_useropts) |
268 | ndopts->nd_useropts = nd_opt; |
269 | } else { |
270 | /* |
271 | * Unknown options must be silently ignored, |
272 | * to accommodate future extension to the |
273 | * protocol. |
274 | */ |
275 | ND_PRINTK(2, notice, |
276 | "%s: ignored unsupported option; type=%d, len=%d\n" , |
277 | __func__, |
278 | nd_opt->nd_opt_type, |
279 | nd_opt->nd_opt_len); |
280 | } |
281 | } |
282 | next_opt: |
283 | opt_len -= l; |
284 | nd_opt = ((void *)nd_opt) + l; |
285 | } |
286 | return ndopts; |
287 | } |
288 | |
289 | int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) |
290 | { |
291 | switch (dev->type) { |
292 | case ARPHRD_ETHER: |
293 | case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ |
294 | case ARPHRD_FDDI: |
295 | ipv6_eth_mc_map(addr, buf); |
296 | return 0; |
297 | case ARPHRD_ARCNET: |
298 | ipv6_arcnet_mc_map(addr, buf); |
299 | return 0; |
300 | case ARPHRD_INFINIBAND: |
301 | ipv6_ib_mc_map(addr, broadcast: dev->broadcast, buf); |
302 | return 0; |
303 | case ARPHRD_IPGRE: |
304 | return ipv6_ipgre_mc_map(addr, broadcast: dev->broadcast, buf); |
305 | default: |
306 | if (dir) { |
307 | memcpy(buf, dev->broadcast, dev->addr_len); |
308 | return 0; |
309 | } |
310 | } |
311 | return -EINVAL; |
312 | } |
313 | EXPORT_SYMBOL(ndisc_mc_map); |
314 | |
315 | static u32 ndisc_hash(const void *pkey, |
316 | const struct net_device *dev, |
317 | __u32 *hash_rnd) |
318 | { |
319 | return ndisc_hashfn(pkey, dev, hash_rnd); |
320 | } |
321 | |
322 | static bool ndisc_key_eq(const struct neighbour *n, const void *pkey) |
323 | { |
324 | return neigh_key_eq128(n, pkey); |
325 | } |
326 | |
327 | static int ndisc_constructor(struct neighbour *neigh) |
328 | { |
329 | struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key; |
330 | struct net_device *dev = neigh->dev; |
331 | struct inet6_dev *in6_dev; |
332 | struct neigh_parms *parms; |
333 | bool is_multicast = ipv6_addr_is_multicast(addr); |
334 | |
335 | in6_dev = in6_dev_get(dev); |
336 | if (!in6_dev) { |
337 | return -EINVAL; |
338 | } |
339 | |
340 | parms = in6_dev->nd_parms; |
341 | __neigh_parms_put(parms: neigh->parms); |
342 | neigh->parms = neigh_parms_clone(parms); |
343 | |
344 | neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; |
345 | if (!dev->header_ops) { |
346 | neigh->nud_state = NUD_NOARP; |
347 | neigh->ops = &ndisc_direct_ops; |
348 | neigh->output = neigh_direct_output; |
349 | } else { |
350 | if (is_multicast) { |
351 | neigh->nud_state = NUD_NOARP; |
352 | ndisc_mc_map(addr, neigh->ha, dev, 1); |
353 | } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { |
354 | neigh->nud_state = NUD_NOARP; |
355 | memcpy(neigh->ha, dev->dev_addr, dev->addr_len); |
356 | if (dev->flags&IFF_LOOPBACK) |
357 | neigh->type = RTN_LOCAL; |
358 | } else if (dev->flags&IFF_POINTOPOINT) { |
359 | neigh->nud_state = NUD_NOARP; |
360 | memcpy(neigh->ha, dev->broadcast, dev->addr_len); |
361 | } |
362 | if (dev->header_ops->cache) |
363 | neigh->ops = &ndisc_hh_ops; |
364 | else |
365 | neigh->ops = &ndisc_generic_ops; |
366 | if (neigh->nud_state&NUD_VALID) |
367 | neigh->output = neigh->ops->connected_output; |
368 | else |
369 | neigh->output = neigh->ops->output; |
370 | } |
371 | in6_dev_put(idev: in6_dev); |
372 | return 0; |
373 | } |
374 | |
375 | static int pndisc_constructor(struct pneigh_entry *n) |
376 | { |
377 | struct in6_addr *addr = (struct in6_addr *)&n->key; |
378 | struct in6_addr maddr; |
379 | struct net_device *dev = n->dev; |
380 | |
381 | if (!dev || !__in6_dev_get(dev)) |
382 | return -EINVAL; |
383 | addrconf_addr_solict_mult(addr, solicited: &maddr); |
384 | ipv6_dev_mc_inc(dev, addr: &maddr); |
385 | return 0; |
386 | } |
387 | |
388 | static void pndisc_destructor(struct pneigh_entry *n) |
389 | { |
390 | struct in6_addr *addr = (struct in6_addr *)&n->key; |
391 | struct in6_addr maddr; |
392 | struct net_device *dev = n->dev; |
393 | |
394 | if (!dev || !__in6_dev_get(dev)) |
395 | return; |
396 | addrconf_addr_solict_mult(addr, solicited: &maddr); |
397 | ipv6_dev_mc_dec(dev, addr: &maddr); |
398 | } |
399 | |
400 | /* called with rtnl held */ |
401 | static bool ndisc_allow_add(const struct net_device *dev, |
402 | struct netlink_ext_ack *extack) |
403 | { |
404 | struct inet6_dev *idev = __in6_dev_get(dev); |
405 | |
406 | if (!idev || idev->cnf.disable_ipv6) { |
407 | NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device" ); |
408 | return false; |
409 | } |
410 | |
411 | return true; |
412 | } |
413 | |
414 | static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, |
415 | int len) |
416 | { |
417 | int hlen = LL_RESERVED_SPACE(dev); |
418 | int tlen = dev->needed_tailroom; |
419 | struct sock *sk = dev_net(dev)->ipv6.ndisc_sk; |
420 | struct sk_buff *skb; |
421 | |
422 | skb = alloc_skb(size: hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); |
423 | if (!skb) { |
424 | ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n" , |
425 | __func__); |
426 | return NULL; |
427 | } |
428 | |
429 | skb->protocol = htons(ETH_P_IPV6); |
430 | skb->dev = dev; |
431 | |
432 | skb_reserve(skb, len: hlen + sizeof(struct ipv6hdr)); |
433 | skb_reset_transport_header(skb); |
434 | |
435 | /* Manually assign socket ownership as we avoid calling |
436 | * sock_alloc_send_pskb() to bypass wmem buffer limits |
437 | */ |
438 | skb_set_owner_w(skb, sk); |
439 | |
440 | return skb; |
441 | } |
442 | |
443 | static void ip6_nd_hdr(struct sk_buff *skb, |
444 | const struct in6_addr *saddr, |
445 | const struct in6_addr *daddr, |
446 | int hop_limit, int len) |
447 | { |
448 | struct ipv6hdr *hdr; |
449 | struct inet6_dev *idev; |
450 | unsigned tclass; |
451 | |
452 | rcu_read_lock(); |
453 | idev = __in6_dev_get(dev: skb->dev); |
454 | tclass = idev ? idev->cnf.ndisc_tclass : 0; |
455 | rcu_read_unlock(); |
456 | |
457 | skb_push(skb, len: sizeof(*hdr)); |
458 | skb_reset_network_header(skb); |
459 | hdr = ipv6_hdr(skb); |
460 | |
461 | ip6_flow_hdr(hdr, tclass, flowlabel: 0); |
462 | |
463 | hdr->payload_len = htons(len); |
464 | hdr->nexthdr = IPPROTO_ICMPV6; |
465 | hdr->hop_limit = hop_limit; |
466 | |
467 | hdr->saddr = *saddr; |
468 | hdr->daddr = *daddr; |
469 | } |
470 | |
471 | void ndisc_send_skb(struct sk_buff *skb, 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(dev: 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: &fl6, type, saddr, daddr, oif); |
489 | dst = icmp6_dst_alloc(dev: skb->dev, fl6: &fl6); |
490 | if (IS_ERR(ptr: 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, len: skb->len, |
499 | IPPROTO_ICMPV6, |
500 | sum: csum_partial(buff: icmp6h, |
501 | len: skb->len, sum: 0)); |
502 | |
503 | ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), len: skb->len); |
504 | |
505 | rcu_read_lock(); |
506 | idev = __in6_dev_get(dev: dst->dev); |
507 | IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS); |
508 | |
509 | err = NF_HOOK(pf: NFPROTO_IPV6, hook: NF_INET_LOCAL_OUT, |
510 | net, sk, skb, NULL, out: dst->dev, |
511 | okfn: 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 | EXPORT_SYMBOL(ndisc_send_skb); |
520 | |
521 | void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, |
522 | const struct in6_addr *solicited_addr, |
523 | bool router, bool solicited, bool override, bool inc_opt) |
524 | { |
525 | struct sk_buff *skb; |
526 | struct in6_addr tmpaddr; |
527 | struct inet6_ifaddr *ifp; |
528 | const struct in6_addr *src_addr; |
529 | struct nd_msg *msg; |
530 | int optlen = 0; |
531 | |
532 | /* for anycast or proxy, solicited_addr != src_addr */ |
533 | ifp = ipv6_get_ifaddr(net: dev_net(dev), addr: solicited_addr, dev, strict: 1); |
534 | if (ifp) { |
535 | src_addr = solicited_addr; |
536 | if (ifp->flags & IFA_F_OPTIMISTIC) |
537 | override = false; |
538 | inc_opt |= ifp->idev->cnf.force_tllao; |
539 | in6_ifa_put(ifp); |
540 | } else { |
541 | if (ipv6_dev_get_saddr(net: dev_net(dev), dev, daddr, |
542 | srcprefs: inet6_sk(sk: dev_net(dev)->ipv6.ndisc_sk)->srcprefs, |
543 | saddr: &tmpaddr)) |
544 | return; |
545 | src_addr = &tmpaddr; |
546 | } |
547 | |
548 | if (!dev->addr_len) |
549 | inc_opt = false; |
550 | if (inc_opt) |
551 | optlen += ndisc_opt_addr_space(dev, |
552 | NDISC_NEIGHBOUR_ADVERTISEMENT); |
553 | |
554 | skb = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen); |
555 | if (!skb) |
556 | return; |
557 | |
558 | msg = skb_put(skb, len: sizeof(*msg)); |
559 | *msg = (struct nd_msg) { |
560 | .icmph = { |
561 | .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, |
562 | .icmp6_router = router, |
563 | .icmp6_solicited = solicited, |
564 | .icmp6_override = override, |
565 | }, |
566 | .target = *solicited_addr, |
567 | }; |
568 | |
569 | if (inc_opt) |
570 | ndisc_fill_addr_option(skb, type: ND_OPT_TARGET_LL_ADDR, |
571 | data: dev->dev_addr, |
572 | NDISC_NEIGHBOUR_ADVERTISEMENT); |
573 | |
574 | ndisc_send_skb(skb, daddr, src_addr); |
575 | } |
576 | |
577 | static void ndisc_send_unsol_na(struct net_device *dev) |
578 | { |
579 | struct inet6_dev *idev; |
580 | struct inet6_ifaddr *ifa; |
581 | |
582 | idev = in6_dev_get(dev); |
583 | if (!idev) |
584 | return; |
585 | |
586 | read_lock_bh(&idev->lock); |
587 | list_for_each_entry(ifa, &idev->addr_list, if_list) { |
588 | /* skip tentative addresses until dad completes */ |
589 | if (ifa->flags & IFA_F_TENTATIVE && |
590 | !(ifa->flags & IFA_F_OPTIMISTIC)) |
591 | continue; |
592 | |
593 | ndisc_send_na(dev, daddr: &in6addr_linklocal_allnodes, solicited_addr: &ifa->addr, |
594 | /*router=*/ !!idev->cnf.forwarding, |
595 | /*solicited=*/ false, /*override=*/ true, |
596 | /*inc_opt=*/ true); |
597 | } |
598 | read_unlock_bh(&idev->lock); |
599 | |
600 | in6_dev_put(idev); |
601 | } |
602 | |
603 | struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit, |
604 | const struct in6_addr *saddr, u64 nonce) |
605 | { |
606 | int inc_opt = dev->addr_len; |
607 | struct sk_buff *skb; |
608 | struct nd_msg *msg; |
609 | int optlen = 0; |
610 | |
611 | if (!saddr) |
612 | return NULL; |
613 | |
614 | if (ipv6_addr_any(a: saddr)) |
615 | inc_opt = false; |
616 | if (inc_opt) |
617 | optlen += ndisc_opt_addr_space(dev, |
618 | NDISC_NEIGHBOUR_SOLICITATION); |
619 | if (nonce != 0) |
620 | optlen += 8; |
621 | |
622 | skb = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen); |
623 | if (!skb) |
624 | return NULL; |
625 | |
626 | msg = skb_put(skb, len: sizeof(*msg)); |
627 | *msg = (struct nd_msg) { |
628 | .icmph = { |
629 | .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, |
630 | }, |
631 | .target = *solicit, |
632 | }; |
633 | |
634 | if (inc_opt) |
635 | ndisc_fill_addr_option(skb, type: ND_OPT_SOURCE_LL_ADDR, |
636 | data: dev->dev_addr, |
637 | NDISC_NEIGHBOUR_SOLICITATION); |
638 | if (nonce != 0) { |
639 | u8 *opt = skb_put(skb, len: 8); |
640 | |
641 | opt[0] = ND_OPT_NONCE; |
642 | opt[1] = 8 >> 3; |
643 | memcpy(opt + 2, &nonce, 6); |
644 | } |
645 | |
646 | return skb; |
647 | } |
648 | EXPORT_SYMBOL(ndisc_ns_create); |
649 | |
650 | void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, |
651 | const struct in6_addr *daddr, const struct in6_addr *saddr, |
652 | u64 nonce) |
653 | { |
654 | struct in6_addr addr_buf; |
655 | struct sk_buff *skb; |
656 | |
657 | if (!saddr) { |
658 | if (ipv6_get_lladdr(dev, addr: &addr_buf, |
659 | banned_flags: (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC))) |
660 | return; |
661 | saddr = &addr_buf; |
662 | } |
663 | |
664 | skb = ndisc_ns_create(dev, solicit, saddr, nonce); |
665 | |
666 | if (skb) |
667 | ndisc_send_skb(skb, daddr, saddr); |
668 | } |
669 | |
670 | void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, |
671 | const struct in6_addr *daddr) |
672 | { |
673 | struct sk_buff *skb; |
674 | struct rs_msg *msg; |
675 | int send_sllao = dev->addr_len; |
676 | int optlen = 0; |
677 | |
678 | #ifdef CONFIG_IPV6_OPTIMISTIC_DAD |
679 | /* |
680 | * According to section 2.2 of RFC 4429, we must not |
681 | * send router solicitations with a sllao from |
682 | * optimistic addresses, but we may send the solicitation |
683 | * if we don't include the sllao. So here we check |
684 | * if our address is optimistic, and if so, we |
685 | * suppress the inclusion of the sllao. |
686 | */ |
687 | if (send_sllao) { |
688 | struct inet6_ifaddr *ifp = ipv6_get_ifaddr(net: dev_net(dev), addr: saddr, |
689 | dev, strict: 1); |
690 | if (ifp) { |
691 | if (ifp->flags & IFA_F_OPTIMISTIC) { |
692 | send_sllao = 0; |
693 | } |
694 | in6_ifa_put(ifp); |
695 | } else { |
696 | send_sllao = 0; |
697 | } |
698 | } |
699 | #endif |
700 | if (send_sllao) |
701 | optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION); |
702 | |
703 | skb = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen); |
704 | if (!skb) |
705 | return; |
706 | |
707 | msg = skb_put(skb, len: sizeof(*msg)); |
708 | *msg = (struct rs_msg) { |
709 | .icmph = { |
710 | .icmp6_type = NDISC_ROUTER_SOLICITATION, |
711 | }, |
712 | }; |
713 | |
714 | if (send_sllao) |
715 | ndisc_fill_addr_option(skb, type: ND_OPT_SOURCE_LL_ADDR, |
716 | data: dev->dev_addr, |
717 | NDISC_ROUTER_SOLICITATION); |
718 | |
719 | ndisc_send_skb(skb, daddr, saddr); |
720 | } |
721 | |
722 | |
723 | static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) |
724 | { |
725 | /* |
726 | * "The sender MUST return an ICMP |
727 | * destination unreachable" |
728 | */ |
729 | dst_link_failure(skb); |
730 | kfree_skb(skb); |
731 | } |
732 | |
733 | /* Called with locked neigh: either read or both */ |
734 | |
735 | static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) |
736 | { |
737 | struct in6_addr *saddr = NULL; |
738 | struct in6_addr mcaddr; |
739 | struct net_device *dev = neigh->dev; |
740 | struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; |
741 | int probes = atomic_read(v: &neigh->probes); |
742 | |
743 | if (skb && ipv6_chk_addr_and_flags(net: dev_net(dev), addr: &ipv6_hdr(skb)->saddr, |
744 | dev, skip_dev_check: false, strict: 1, |
745 | IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) |
746 | saddr = &ipv6_hdr(skb)->saddr; |
747 | probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); |
748 | if (probes < 0) { |
749 | if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) { |
750 | ND_PRINTK(1, dbg, |
751 | "%s: trying to ucast probe in NUD_INVALID: %pI6\n" , |
752 | __func__, target); |
753 | } |
754 | ndisc_send_ns(dev, solicit: target, daddr: target, saddr, nonce: 0); |
755 | } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) { |
756 | neigh_app_ns(n: neigh); |
757 | } else { |
758 | addrconf_addr_solict_mult(addr: target, solicited: &mcaddr); |
759 | ndisc_send_ns(dev, solicit: target, daddr: &mcaddr, saddr, nonce: 0); |
760 | } |
761 | } |
762 | |
763 | static int pndisc_is_router(const void *pkey, |
764 | struct net_device *dev) |
765 | { |
766 | struct pneigh_entry *n; |
767 | int ret = -1; |
768 | |
769 | read_lock_bh(&nd_tbl.lock); |
770 | n = __pneigh_lookup(tbl: &nd_tbl, net: dev_net(dev), key: pkey, dev); |
771 | if (n) |
772 | ret = !!(n->flags & NTF_ROUTER); |
773 | read_unlock_bh(&nd_tbl.lock); |
774 | |
775 | return ret; |
776 | } |
777 | |
778 | void ndisc_update(const struct net_device *dev, struct neighbour *neigh, |
779 | const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type, |
780 | struct ndisc_options *ndopts) |
781 | { |
782 | neigh_update(neigh, lladdr, new, flags, nlmsg_pid: 0); |
783 | /* report ndisc ops about neighbour update */ |
784 | ndisc_ops_update(dev, n: neigh, flags, icmp6_type, ndopts); |
785 | } |
786 | |
787 | static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb) |
788 | { |
789 | struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); |
790 | const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; |
791 | const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; |
792 | u8 *lladdr = NULL; |
793 | u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + |
794 | offsetof(struct nd_msg, opt)); |
795 | struct ndisc_options ndopts; |
796 | struct net_device *dev = skb->dev; |
797 | struct inet6_ifaddr *ifp; |
798 | struct inet6_dev *idev = NULL; |
799 | struct neighbour *neigh; |
800 | int dad = ipv6_addr_any(a: saddr); |
801 | int is_router = -1; |
802 | SKB_DR(reason); |
803 | u64 nonce = 0; |
804 | bool inc; |
805 | |
806 | if (skb->len < sizeof(struct nd_msg)) |
807 | return SKB_DROP_REASON_PKT_TOO_SMALL; |
808 | |
809 | if (ipv6_addr_is_multicast(addr: &msg->target)) { |
810 | ND_PRINTK(2, warn, "NS: multicast target address\n" ); |
811 | return reason; |
812 | } |
813 | |
814 | /* |
815 | * RFC2461 7.1.1: |
816 | * DAD has to be destined for solicited node multicast address. |
817 | */ |
818 | if (dad && !ipv6_addr_is_solict_mult(addr: daddr)) { |
819 | ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n" ); |
820 | return reason; |
821 | } |
822 | |
823 | if (!ndisc_parse_options(dev, opt: msg->opt, opt_len: ndoptlen, ndopts: &ndopts)) |
824 | return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; |
825 | |
826 | if (ndopts.nd_opts_src_lladdr) { |
827 | lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_src_lladdr, dev); |
828 | if (!lladdr) { |
829 | ND_PRINTK(2, warn, |
830 | "NS: invalid link-layer address length\n" ); |
831 | return reason; |
832 | } |
833 | |
834 | /* RFC2461 7.1.1: |
835 | * If the IP source address is the unspecified address, |
836 | * there MUST NOT be source link-layer address option |
837 | * in the message. |
838 | */ |
839 | if (dad) { |
840 | ND_PRINTK(2, warn, |
841 | "NS: bad DAD packet (link-layer address option)\n" ); |
842 | return reason; |
843 | } |
844 | } |
845 | if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1) |
846 | memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6); |
847 | |
848 | inc = ipv6_addr_is_multicast(addr: daddr); |
849 | |
850 | ifp = ipv6_get_ifaddr(net: dev_net(dev), addr: &msg->target, dev, strict: 1); |
851 | if (ifp) { |
852 | have_ifp: |
853 | if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { |
854 | if (dad) { |
855 | if (nonce != 0 && ifp->dad_nonce == nonce) { |
856 | u8 *np = (u8 *)&nonce; |
857 | /* Matching nonce if looped back */ |
858 | ND_PRINTK(2, notice, |
859 | "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n" , |
860 | ifp->idev->dev->name, |
861 | &ifp->addr, np); |
862 | goto out; |
863 | } |
864 | /* |
865 | * We are colliding with another node |
866 | * who is doing DAD |
867 | * so fail our DAD process |
868 | */ |
869 | addrconf_dad_failure(skb, ifp); |
870 | return reason; |
871 | } else { |
872 | /* |
873 | * This is not a dad solicitation. |
874 | * If we are an optimistic node, |
875 | * we should respond. |
876 | * Otherwise, we should ignore it. |
877 | */ |
878 | if (!(ifp->flags & IFA_F_OPTIMISTIC)) |
879 | goto out; |
880 | } |
881 | } |
882 | |
883 | idev = ifp->idev; |
884 | } else { |
885 | struct net *net = dev_net(dev); |
886 | |
887 | /* perhaps an address on the master device */ |
888 | if (netif_is_l3_slave(dev)) { |
889 | struct net_device *mdev; |
890 | |
891 | mdev = netdev_master_upper_dev_get_rcu(dev); |
892 | if (mdev) { |
893 | ifp = ipv6_get_ifaddr(net, addr: &msg->target, dev: mdev, strict: 1); |
894 | if (ifp) |
895 | goto have_ifp; |
896 | } |
897 | } |
898 | |
899 | idev = in6_dev_get(dev); |
900 | if (!idev) { |
901 | /* XXX: count this drop? */ |
902 | return reason; |
903 | } |
904 | |
905 | if (ipv6_chk_acast_addr(net, dev, addr: &msg->target) || |
906 | (idev->cnf.forwarding && |
907 | (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && |
908 | (is_router = pndisc_is_router(pkey: &msg->target, dev)) >= 0)) { |
909 | if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && |
910 | skb->pkt_type != PACKET_HOST && |
911 | inc && |
912 | NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) { |
913 | /* |
914 | * for anycast or proxy, |
915 | * sender should delay its response |
916 | * by a random time between 0 and |
917 | * MAX_ANYCAST_DELAY_TIME seconds. |
918 | * (RFC2461) -- yoshfuji |
919 | */ |
920 | struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); |
921 | if (n) |
922 | pneigh_enqueue(tbl: &nd_tbl, p: idev->nd_parms, skb: n); |
923 | goto out; |
924 | } |
925 | } else { |
926 | SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST); |
927 | goto out; |
928 | } |
929 | } |
930 | |
931 | if (is_router < 0) |
932 | is_router = idev->cnf.forwarding; |
933 | |
934 | if (dad) { |
935 | ndisc_send_na(dev, daddr: &in6addr_linklocal_allnodes, solicited_addr: &msg->target, |
936 | router: !!is_router, solicited: false, override: (ifp != NULL), inc_opt: true); |
937 | goto out; |
938 | } |
939 | |
940 | if (inc) |
941 | NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); |
942 | else |
943 | NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); |
944 | |
945 | /* |
946 | * update / create cache entry |
947 | * for the source address |
948 | */ |
949 | neigh = __neigh_lookup(tbl: &nd_tbl, pkey: saddr, dev, |
950 | creat: !inc || lladdr || !dev->addr_len); |
951 | if (neigh) |
952 | ndisc_update(dev, neigh, lladdr, NUD_STALE, |
953 | NEIGH_UPDATE_F_WEAK_OVERRIDE| |
954 | NEIGH_UPDATE_F_OVERRIDE, |
955 | NDISC_NEIGHBOUR_SOLICITATION, ndopts: &ndopts); |
956 | if (neigh || !dev->header_ops) { |
957 | ndisc_send_na(dev, daddr: saddr, solicited_addr: &msg->target, router: !!is_router, |
958 | solicited: true, override: (ifp != NULL && inc), inc_opt: inc); |
959 | if (neigh) |
960 | neigh_release(neigh); |
961 | reason = SKB_CONSUMED; |
962 | } |
963 | |
964 | out: |
965 | if (ifp) |
966 | in6_ifa_put(ifp); |
967 | else |
968 | in6_dev_put(idev); |
969 | return reason; |
970 | } |
971 | |
972 | static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr) |
973 | { |
974 | struct inet6_dev *idev = __in6_dev_get(dev); |
975 | |
976 | switch (idev->cnf.accept_untracked_na) { |
977 | case 0: /* Don't accept untracked na (absent in neighbor cache) */ |
978 | return 0; |
979 | case 1: /* Create new entries from na if currently untracked */ |
980 | return 1; |
981 | case 2: /* Create new entries from untracked na only if saddr is in the |
982 | * same subnet as an address configured on the interface that |
983 | * received the na |
984 | */ |
985 | return !!ipv6_chk_prefix(addr: saddr, dev); |
986 | default: |
987 | return 0; |
988 | } |
989 | } |
990 | |
991 | static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb) |
992 | { |
993 | struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); |
994 | struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; |
995 | const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; |
996 | u8 *lladdr = NULL; |
997 | u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + |
998 | offsetof(struct nd_msg, opt)); |
999 | struct ndisc_options ndopts; |
1000 | struct net_device *dev = skb->dev; |
1001 | struct inet6_dev *idev = __in6_dev_get(dev); |
1002 | struct inet6_ifaddr *ifp; |
1003 | struct neighbour *neigh; |
1004 | SKB_DR(reason); |
1005 | u8 new_state; |
1006 | |
1007 | if (skb->len < sizeof(struct nd_msg)) |
1008 | return SKB_DROP_REASON_PKT_TOO_SMALL; |
1009 | |
1010 | if (ipv6_addr_is_multicast(addr: &msg->target)) { |
1011 | ND_PRINTK(2, warn, "NA: target address is multicast\n" ); |
1012 | return reason; |
1013 | } |
1014 | |
1015 | if (ipv6_addr_is_multicast(addr: daddr) && |
1016 | msg->icmph.icmp6_solicited) { |
1017 | ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n" ); |
1018 | return reason; |
1019 | } |
1020 | |
1021 | /* For some 802.11 wireless deployments (and possibly other networks), |
1022 | * there will be a NA proxy and unsolicitd packets are attacks |
1023 | * and thus should not be accepted. |
1024 | * drop_unsolicited_na takes precedence over accept_untracked_na |
1025 | */ |
1026 | if (!msg->icmph.icmp6_solicited && idev && |
1027 | idev->cnf.drop_unsolicited_na) |
1028 | return reason; |
1029 | |
1030 | if (!ndisc_parse_options(dev, opt: msg->opt, opt_len: ndoptlen, ndopts: &ndopts)) |
1031 | return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; |
1032 | |
1033 | if (ndopts.nd_opts_tgt_lladdr) { |
1034 | lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_tgt_lladdr, dev); |
1035 | if (!lladdr) { |
1036 | ND_PRINTK(2, warn, |
1037 | "NA: invalid link-layer address length\n" ); |
1038 | return reason; |
1039 | } |
1040 | } |
1041 | ifp = ipv6_get_ifaddr(net: dev_net(dev), addr: &msg->target, dev, strict: 1); |
1042 | if (ifp) { |
1043 | if (skb->pkt_type != PACKET_LOOPBACK |
1044 | && (ifp->flags & IFA_F_TENTATIVE)) { |
1045 | addrconf_dad_failure(skb, ifp); |
1046 | return reason; |
1047 | } |
1048 | /* What should we make now? The advertisement |
1049 | is invalid, but ndisc specs say nothing |
1050 | about it. It could be misconfiguration, or |
1051 | an smart proxy agent tries to help us :-) |
1052 | |
1053 | We should not print the error if NA has been |
1054 | received from loopback - it is just our own |
1055 | unsolicited advertisement. |
1056 | */ |
1057 | if (skb->pkt_type != PACKET_LOOPBACK) |
1058 | ND_PRINTK(1, warn, |
1059 | "NA: %pM advertised our address %pI6c on %s!\n" , |
1060 | eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name); |
1061 | in6_ifa_put(ifp); |
1062 | return reason; |
1063 | } |
1064 | |
1065 | neigh = neigh_lookup(tbl: &nd_tbl, pkey: &msg->target, dev); |
1066 | |
1067 | /* RFC 9131 updates original Neighbour Discovery RFC 4861. |
1068 | * NAs with Target LL Address option without a corresponding |
1069 | * entry in the neighbour cache can now create a STALE neighbour |
1070 | * cache entry on routers. |
1071 | * |
1072 | * entry accept fwding solicited behaviour |
1073 | * ------- ------ ------ --------- ---------------------- |
1074 | * present X X 0 Set state to STALE |
1075 | * present X X 1 Set state to REACHABLE |
1076 | * absent 0 X X Do nothing |
1077 | * absent 1 0 X Do nothing |
1078 | * absent 1 1 X Add a new STALE entry |
1079 | * |
1080 | * Note that we don't do a (daddr == all-routers-mcast) check. |
1081 | */ |
1082 | new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE; |
1083 | if (!neigh && lladdr && idev && idev->cnf.forwarding) { |
1084 | if (accept_untracked_na(dev, saddr)) { |
1085 | neigh = neigh_create(tbl: &nd_tbl, pkey: &msg->target, dev); |
1086 | new_state = NUD_STALE; |
1087 | } |
1088 | } |
1089 | |
1090 | if (neigh && !IS_ERR(ptr: neigh)) { |
1091 | u8 old_flags = neigh->flags; |
1092 | struct net *net = dev_net(dev); |
1093 | |
1094 | if (READ_ONCE(neigh->nud_state) & NUD_FAILED) |
1095 | goto out; |
1096 | |
1097 | /* |
1098 | * Don't update the neighbor cache entry on a proxy NA from |
1099 | * ourselves because either the proxied node is off link or it |
1100 | * has already sent a NA to us. |
1101 | */ |
1102 | if (lladdr && !memcmp(p: lladdr, q: dev->dev_addr, size: dev->addr_len) && |
1103 | net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && |
1104 | pneigh_lookup(tbl: &nd_tbl, net, key: &msg->target, dev, creat: 0)) { |
1105 | /* XXX: idev->cnf.proxy_ndp */ |
1106 | goto out; |
1107 | } |
1108 | |
1109 | ndisc_update(dev, neigh, lladdr, |
1110 | new: new_state, |
1111 | NEIGH_UPDATE_F_WEAK_OVERRIDE| |
1112 | (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| |
1113 | NEIGH_UPDATE_F_OVERRIDE_ISROUTER| |
1114 | (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0), |
1115 | NDISC_NEIGHBOUR_ADVERTISEMENT, ndopts: &ndopts); |
1116 | |
1117 | if ((old_flags & ~neigh->flags) & NTF_ROUTER) { |
1118 | /* |
1119 | * Change: router to host |
1120 | */ |
1121 | rt6_clean_tohost(net: dev_net(dev), gateway: saddr); |
1122 | } |
1123 | reason = SKB_CONSUMED; |
1124 | out: |
1125 | neigh_release(neigh); |
1126 | } |
1127 | return reason; |
1128 | } |
1129 | |
1130 | static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb) |
1131 | { |
1132 | struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); |
1133 | unsigned long ndoptlen = skb->len - sizeof(*rs_msg); |
1134 | struct neighbour *neigh; |
1135 | struct inet6_dev *idev; |
1136 | const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; |
1137 | struct ndisc_options ndopts; |
1138 | u8 *lladdr = NULL; |
1139 | SKB_DR(reason); |
1140 | |
1141 | if (skb->len < sizeof(*rs_msg)) |
1142 | return SKB_DROP_REASON_PKT_TOO_SMALL; |
1143 | |
1144 | idev = __in6_dev_get(dev: skb->dev); |
1145 | if (!idev) { |
1146 | ND_PRINTK(1, err, "RS: can't find in6 device\n" ); |
1147 | return reason; |
1148 | } |
1149 | |
1150 | /* Don't accept RS if we're not in router mode */ |
1151 | if (!idev->cnf.forwarding) |
1152 | goto out; |
1153 | |
1154 | /* |
1155 | * Don't update NCE if src = ::; |
1156 | * this implies that the source node has no ip address assigned yet. |
1157 | */ |
1158 | if (ipv6_addr_any(a: saddr)) |
1159 | goto out; |
1160 | |
1161 | /* Parse ND options */ |
1162 | if (!ndisc_parse_options(dev: skb->dev, opt: rs_msg->opt, opt_len: ndoptlen, ndopts: &ndopts)) |
1163 | return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; |
1164 | |
1165 | if (ndopts.nd_opts_src_lladdr) { |
1166 | lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_src_lladdr, |
1167 | dev: skb->dev); |
1168 | if (!lladdr) |
1169 | goto out; |
1170 | } |
1171 | |
1172 | neigh = __neigh_lookup(tbl: &nd_tbl, pkey: saddr, dev: skb->dev, creat: 1); |
1173 | if (neigh) { |
1174 | ndisc_update(dev: skb->dev, neigh, lladdr, NUD_STALE, |
1175 | NEIGH_UPDATE_F_WEAK_OVERRIDE| |
1176 | NEIGH_UPDATE_F_OVERRIDE| |
1177 | NEIGH_UPDATE_F_OVERRIDE_ISROUTER, |
1178 | NDISC_ROUTER_SOLICITATION, ndopts: &ndopts); |
1179 | neigh_release(neigh); |
1180 | reason = SKB_CONSUMED; |
1181 | } |
1182 | out: |
1183 | return reason; |
1184 | } |
1185 | |
1186 | static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) |
1187 | { |
1188 | struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(skb: ra); |
1189 | struct sk_buff *skb; |
1190 | struct nlmsghdr *nlh; |
1191 | struct nduseroptmsg *ndmsg; |
1192 | struct net *net = dev_net(dev: ra->dev); |
1193 | int err; |
1194 | int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) |
1195 | + (opt->nd_opt_len << 3)); |
1196 | size_t msg_size = base_size + nla_total_size(payload: sizeof(struct in6_addr)); |
1197 | |
1198 | skb = nlmsg_new(payload: msg_size, GFP_ATOMIC); |
1199 | if (!skb) { |
1200 | err = -ENOBUFS; |
1201 | goto errout; |
1202 | } |
1203 | |
1204 | nlh = nlmsg_put(skb, portid: 0, seq: 0, RTM_NEWNDUSEROPT, payload: base_size, flags: 0); |
1205 | if (!nlh) { |
1206 | goto nla_put_failure; |
1207 | } |
1208 | |
1209 | ndmsg = nlmsg_data(nlh); |
1210 | ndmsg->nduseropt_family = AF_INET6; |
1211 | ndmsg->nduseropt_ifindex = ra->dev->ifindex; |
1212 | ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; |
1213 | ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; |
1214 | ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; |
1215 | |
1216 | memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); |
1217 | |
1218 | if (nla_put_in6_addr(skb, attrtype: NDUSEROPT_SRCADDR, addr: &ipv6_hdr(skb: ra)->saddr)) |
1219 | goto nla_put_failure; |
1220 | nlmsg_end(skb, nlh); |
1221 | |
1222 | rtnl_notify(skb, net, pid: 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); |
1223 | return; |
1224 | |
1225 | nla_put_failure: |
1226 | nlmsg_free(skb); |
1227 | err = -EMSGSIZE; |
1228 | errout: |
1229 | rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, error: err); |
1230 | } |
1231 | |
1232 | static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) |
1233 | { |
1234 | struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); |
1235 | bool send_ifinfo_notify = false; |
1236 | struct neighbour *neigh = NULL; |
1237 | struct ndisc_options ndopts; |
1238 | struct fib6_info *rt = NULL; |
1239 | struct inet6_dev *in6_dev; |
1240 | u32 defrtr_usr_metric; |
1241 | unsigned int pref = 0; |
1242 | __u32 old_if_flags; |
1243 | struct net *net; |
1244 | SKB_DR(reason); |
1245 | int lifetime; |
1246 | int optlen; |
1247 | |
1248 | __u8 *opt = (__u8 *)(ra_msg + 1); |
1249 | |
1250 | optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - |
1251 | sizeof(struct ra_msg); |
1252 | |
1253 | ND_PRINTK(2, info, |
1254 | "RA: %s, dev: %s\n" , |
1255 | __func__, skb->dev->name); |
1256 | if (!(ipv6_addr_type(addr: &ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { |
1257 | ND_PRINTK(2, warn, "RA: source address is not link-local\n" ); |
1258 | return reason; |
1259 | } |
1260 | if (optlen < 0) |
1261 | return SKB_DROP_REASON_PKT_TOO_SMALL; |
1262 | |
1263 | #ifdef CONFIG_IPV6_NDISC_NODETYPE |
1264 | if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { |
1265 | ND_PRINTK(2, warn, "RA: from host or unauthorized router\n" ); |
1266 | return reason; |
1267 | } |
1268 | #endif |
1269 | |
1270 | in6_dev = __in6_dev_get(dev: skb->dev); |
1271 | if (!in6_dev) { |
1272 | ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n" , |
1273 | skb->dev->name); |
1274 | return reason; |
1275 | } |
1276 | |
1277 | if (!ndisc_parse_options(dev: skb->dev, opt, opt_len: optlen, ndopts: &ndopts)) |
1278 | return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; |
1279 | |
1280 | if (!ipv6_accept_ra(idev: in6_dev)) { |
1281 | ND_PRINTK(2, info, |
1282 | "RA: %s, did not accept ra for dev: %s\n" , |
1283 | __func__, skb->dev->name); |
1284 | goto skip_linkparms; |
1285 | } |
1286 | |
1287 | #ifdef CONFIG_IPV6_NDISC_NODETYPE |
1288 | /* skip link-specific parameters from interior routers */ |
1289 | if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { |
1290 | ND_PRINTK(2, info, |
1291 | "RA: %s, nodetype is NODEFAULT, dev: %s\n" , |
1292 | __func__, skb->dev->name); |
1293 | goto skip_linkparms; |
1294 | } |
1295 | #endif |
1296 | |
1297 | if (in6_dev->if_flags & IF_RS_SENT) { |
1298 | /* |
1299 | * flag that an RA was received after an RS was sent |
1300 | * out on this interface. |
1301 | */ |
1302 | in6_dev->if_flags |= IF_RA_RCVD; |
1303 | } |
1304 | |
1305 | /* |
1306 | * Remember the managed/otherconf flags from most recently |
1307 | * received RA message (RFC 2462) -- yoshfuji |
1308 | */ |
1309 | old_if_flags = in6_dev->if_flags; |
1310 | in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | |
1311 | IF_RA_OTHERCONF)) | |
1312 | (ra_msg->icmph.icmp6_addrconf_managed ? |
1313 | IF_RA_MANAGED : 0) | |
1314 | (ra_msg->icmph.icmp6_addrconf_other ? |
1315 | IF_RA_OTHERCONF : 0); |
1316 | |
1317 | if (old_if_flags != in6_dev->if_flags) |
1318 | send_ifinfo_notify = true; |
1319 | |
1320 | if (!in6_dev->cnf.accept_ra_defrtr) { |
1321 | ND_PRINTK(2, info, |
1322 | "RA: %s, defrtr is false for dev: %s\n" , |
1323 | __func__, skb->dev->name); |
1324 | goto skip_defrtr; |
1325 | } |
1326 | |
1327 | lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); |
1328 | if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_lft) { |
1329 | ND_PRINTK(2, info, |
1330 | "RA: router lifetime (%ds) is too short: %s\n" , |
1331 | lifetime, skb->dev->name); |
1332 | goto skip_defrtr; |
1333 | } |
1334 | |
1335 | /* Do not accept RA with source-addr found on local machine unless |
1336 | * accept_ra_from_local is set to true. |
1337 | */ |
1338 | net = dev_net(dev: in6_dev->dev); |
1339 | if (!in6_dev->cnf.accept_ra_from_local && |
1340 | ipv6_chk_addr(net, addr: &ipv6_hdr(skb)->saddr, dev: in6_dev->dev, strict: 0)) { |
1341 | ND_PRINTK(2, info, |
1342 | "RA from local address detected on dev: %s: default router ignored\n" , |
1343 | skb->dev->name); |
1344 | goto skip_defrtr; |
1345 | } |
1346 | |
1347 | #ifdef CONFIG_IPV6_ROUTER_PREF |
1348 | pref = ra_msg->icmph.icmp6_router_pref; |
1349 | /* 10b is handled as if it were 00b (medium) */ |
1350 | if (pref == ICMPV6_ROUTER_PREF_INVALID || |
1351 | !in6_dev->cnf.accept_ra_rtr_pref) |
1352 | pref = ICMPV6_ROUTER_PREF_MEDIUM; |
1353 | #endif |
1354 | /* routes added from RAs do not use nexthop objects */ |
1355 | rt = rt6_get_dflt_router(net, addr: &ipv6_hdr(skb)->saddr, dev: skb->dev); |
1356 | if (rt) { |
1357 | neigh = ip6_neigh_lookup(gw: &rt->fib6_nh->fib_nh_gw6, |
1358 | dev: rt->fib6_nh->fib_nh_dev, NULL, |
1359 | daddr: &ipv6_hdr(skb)->saddr); |
1360 | if (!neigh) { |
1361 | ND_PRINTK(0, err, |
1362 | "RA: %s got default router without neighbour\n" , |
1363 | __func__); |
1364 | fib6_info_release(f6i: rt); |
1365 | return reason; |
1366 | } |
1367 | } |
1368 | /* Set default route metric as specified by user */ |
1369 | defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; |
1370 | /* delete the route if lifetime is 0 or if metric needs change */ |
1371 | if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { |
1372 | ip6_del_rt(net, f6i: rt, skip_notify: false); |
1373 | rt = NULL; |
1374 | } |
1375 | |
1376 | ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n" , |
1377 | rt, lifetime, defrtr_usr_metric, skb->dev->name); |
1378 | if (!rt && lifetime) { |
1379 | ND_PRINTK(3, info, "RA: adding default router\n" ); |
1380 | |
1381 | if (neigh) |
1382 | neigh_release(neigh); |
1383 | |
1384 | rt = rt6_add_dflt_router(net, gwaddr: &ipv6_hdr(skb)->saddr, |
1385 | dev: skb->dev, pref, defrtr_usr_metric); |
1386 | if (!rt) { |
1387 | ND_PRINTK(0, err, |
1388 | "RA: %s failed to add default route\n" , |
1389 | __func__); |
1390 | return reason; |
1391 | } |
1392 | |
1393 | neigh = ip6_neigh_lookup(gw: &rt->fib6_nh->fib_nh_gw6, |
1394 | dev: rt->fib6_nh->fib_nh_dev, NULL, |
1395 | daddr: &ipv6_hdr(skb)->saddr); |
1396 | if (!neigh) { |
1397 | ND_PRINTK(0, err, |
1398 | "RA: %s got default router without neighbour\n" , |
1399 | __func__); |
1400 | fib6_info_release(f6i: rt); |
1401 | return reason; |
1402 | } |
1403 | neigh->flags |= NTF_ROUTER; |
1404 | } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { |
1405 | struct nl_info nlinfo = { |
1406 | .nl_net = net, |
1407 | }; |
1408 | rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); |
1409 | inet6_rt_notify(RTM_NEWROUTE, rt, info: &nlinfo, NLM_F_REPLACE); |
1410 | } |
1411 | |
1412 | if (rt) |
1413 | fib6_set_expires(f6i: rt, expires: jiffies + (HZ * lifetime)); |
1414 | if (in6_dev->cnf.accept_ra_min_hop_limit < 256 && |
1415 | ra_msg->icmph.icmp6_hop_limit) { |
1416 | if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) { |
1417 | in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; |
1418 | fib6_metric_set(f6i: rt, RTAX_HOPLIMIT, |
1419 | val: ra_msg->icmph.icmp6_hop_limit); |
1420 | } else { |
1421 | ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n" ); |
1422 | } |
1423 | } |
1424 | |
1425 | skip_defrtr: |
1426 | |
1427 | /* |
1428 | * Update Reachable Time and Retrans Timer |
1429 | */ |
1430 | |
1431 | if (in6_dev->nd_parms) { |
1432 | unsigned long rtime = ntohl(ra_msg->retrans_timer); |
1433 | |
1434 | if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { |
1435 | rtime = (rtime*HZ)/1000; |
1436 | if (rtime < HZ/100) |
1437 | rtime = HZ/100; |
1438 | NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); |
1439 | in6_dev->tstamp = jiffies; |
1440 | send_ifinfo_notify = true; |
1441 | } |
1442 | |
1443 | rtime = ntohl(ra_msg->reachable_time); |
1444 | if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { |
1445 | rtime = (rtime*HZ)/1000; |
1446 | |
1447 | if (rtime < HZ/10) |
1448 | rtime = HZ/10; |
1449 | |
1450 | if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { |
1451 | NEIGH_VAR_SET(in6_dev->nd_parms, |
1452 | BASE_REACHABLE_TIME, rtime); |
1453 | NEIGH_VAR_SET(in6_dev->nd_parms, |
1454 | GC_STALETIME, 3 * rtime); |
1455 | in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(base: rtime); |
1456 | in6_dev->tstamp = jiffies; |
1457 | send_ifinfo_notify = true; |
1458 | } |
1459 | } |
1460 | } |
1461 | |
1462 | skip_linkparms: |
1463 | |
1464 | /* |
1465 | * Process options. |
1466 | */ |
1467 | |
1468 | if (!neigh) |
1469 | neigh = __neigh_lookup(tbl: &nd_tbl, pkey: &ipv6_hdr(skb)->saddr, |
1470 | dev: skb->dev, creat: 1); |
1471 | if (neigh) { |
1472 | u8 *lladdr = NULL; |
1473 | if (ndopts.nd_opts_src_lladdr) { |
1474 | lladdr = ndisc_opt_addr_data(p: ndopts.nd_opts_src_lladdr, |
1475 | dev: skb->dev); |
1476 | if (!lladdr) { |
1477 | ND_PRINTK(2, warn, |
1478 | "RA: invalid link-layer address length\n" ); |
1479 | goto out; |
1480 | } |
1481 | } |
1482 | ndisc_update(dev: skb->dev, neigh, lladdr, NUD_STALE, |
1483 | NEIGH_UPDATE_F_WEAK_OVERRIDE| |
1484 | NEIGH_UPDATE_F_OVERRIDE| |
1485 | NEIGH_UPDATE_F_OVERRIDE_ISROUTER| |
1486 | NEIGH_UPDATE_F_ISROUTER, |
1487 | NDISC_ROUTER_ADVERTISEMENT, ndopts: &ndopts); |
1488 | reason = SKB_CONSUMED; |
1489 | } |
1490 | |
1491 | if (!ipv6_accept_ra(idev: in6_dev)) { |
1492 | ND_PRINTK(2, info, |
1493 | "RA: %s, accept_ra is false for dev: %s\n" , |
1494 | __func__, skb->dev->name); |
1495 | goto out; |
1496 | } |
1497 | |
1498 | #ifdef CONFIG_IPV6_ROUTE_INFO |
1499 | if (!in6_dev->cnf.accept_ra_from_local && |
1500 | ipv6_chk_addr(net: dev_net(dev: in6_dev->dev), addr: &ipv6_hdr(skb)->saddr, |
1501 | dev: in6_dev->dev, strict: 0)) { |
1502 | ND_PRINTK(2, info, |
1503 | "RA from local address detected on dev: %s: router info ignored.\n" , |
1504 | skb->dev->name); |
1505 | goto skip_routeinfo; |
1506 | } |
1507 | |
1508 | if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { |
1509 | struct nd_opt_hdr *p; |
1510 | for (p = ndopts.nd_opts_ri; |
1511 | p; |
1512 | p = ndisc_next_option(cur: p, end: ndopts.nd_opts_ri_end)) { |
1513 | struct route_info *ri = (struct route_info *)p; |
1514 | #ifdef CONFIG_IPV6_NDISC_NODETYPE |
1515 | if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && |
1516 | ri->prefix_len == 0) |
1517 | continue; |
1518 | #endif |
1519 | if (ri->prefix_len == 0 && |
1520 | !in6_dev->cnf.accept_ra_defrtr) |
1521 | continue; |
1522 | if (ri->lifetime != 0 && |
1523 | ntohl(ri->lifetime) < in6_dev->cnf.accept_ra_min_lft) |
1524 | continue; |
1525 | if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen) |
1526 | continue; |
1527 | if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) |
1528 | continue; |
1529 | rt6_route_rcv(dev: skb->dev, opt: (u8 *)p, len: (p->nd_opt_len) << 3, |
1530 | gwaddr: &ipv6_hdr(skb)->saddr); |
1531 | } |
1532 | } |
1533 | |
1534 | skip_routeinfo: |
1535 | #endif |
1536 | |
1537 | #ifdef CONFIG_IPV6_NDISC_NODETYPE |
1538 | /* skip link-specific ndopts from interior routers */ |
1539 | if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { |
1540 | ND_PRINTK(2, info, |
1541 | "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n" , |
1542 | __func__, skb->dev->name); |
1543 | goto out; |
1544 | } |
1545 | #endif |
1546 | |
1547 | if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { |
1548 | struct nd_opt_hdr *p; |
1549 | for (p = ndopts.nd_opts_pi; |
1550 | p; |
1551 | p = ndisc_next_option(cur: p, end: ndopts.nd_opts_pi_end)) { |
1552 | addrconf_prefix_rcv(dev: skb->dev, opt: (u8 *)p, |
1553 | len: (p->nd_opt_len) << 3, |
1554 | sllao: ndopts.nd_opts_src_lladdr != NULL); |
1555 | } |
1556 | } |
1557 | |
1558 | if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) { |
1559 | __be32 n; |
1560 | u32 mtu; |
1561 | |
1562 | memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); |
1563 | mtu = ntohl(n); |
1564 | |
1565 | if (in6_dev->ra_mtu != mtu) { |
1566 | in6_dev->ra_mtu = mtu; |
1567 | send_ifinfo_notify = true; |
1568 | } |
1569 | |
1570 | if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { |
1571 | ND_PRINTK(2, warn, "RA: invalid mtu: %d\n" , mtu); |
1572 | } else if (in6_dev->cnf.mtu6 != mtu) { |
1573 | in6_dev->cnf.mtu6 = mtu; |
1574 | fib6_metric_set(f6i: rt, RTAX_MTU, val: mtu); |
1575 | rt6_mtu_change(dev: skb->dev, mtu); |
1576 | } |
1577 | } |
1578 | |
1579 | if (ndopts.nd_useropts) { |
1580 | struct nd_opt_hdr *p; |
1581 | for (p = ndopts.nd_useropts; |
1582 | p; |
1583 | p = ndisc_next_useropt(dev: skb->dev, cur: p, |
1584 | end: ndopts.nd_useropts_end)) { |
1585 | ndisc_ra_useropt(ra: skb, opt: p); |
1586 | } |
1587 | } |
1588 | |
1589 | if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { |
1590 | ND_PRINTK(2, warn, "RA: invalid RA options\n" ); |
1591 | } |
1592 | out: |
1593 | /* Send a notify if RA changed managed/otherconf flags or |
1594 | * timer settings or ra_mtu value |
1595 | */ |
1596 | if (send_ifinfo_notify) |
1597 | inet6_ifinfo_notify(RTM_NEWLINK, idev: in6_dev); |
1598 | |
1599 | fib6_info_release(f6i: rt); |
1600 | if (neigh) |
1601 | neigh_release(neigh); |
1602 | return reason; |
1603 | } |
1604 | |
1605 | static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) |
1606 | { |
1607 | struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); |
1608 | u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + |
1609 | offsetof(struct rd_msg, opt)); |
1610 | struct ndisc_options ndopts; |
1611 | SKB_DR(reason); |
1612 | u8 *hdr; |
1613 | |
1614 | #ifdef CONFIG_IPV6_NDISC_NODETYPE |
1615 | switch (skb->ndisc_nodetype) { |
1616 | case NDISC_NODETYPE_HOST: |
1617 | case NDISC_NODETYPE_NODEFAULT: |
1618 | ND_PRINTK(2, warn, |
1619 | "Redirect: from host or unauthorized router\n" ); |
1620 | return reason; |
1621 | } |
1622 | #endif |
1623 | |
1624 | if (!(ipv6_addr_type(addr: &ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { |
1625 | ND_PRINTK(2, warn, |
1626 | "Redirect: source address is not link-local\n" ); |
1627 | return reason; |
1628 | } |
1629 | |
1630 | if (!ndisc_parse_options(dev: skb->dev, opt: msg->opt, opt_len: ndoptlen, ndopts: &ndopts)) |
1631 | return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; |
1632 | |
1633 | if (!ndopts.nd_opts_rh) { |
1634 | ip6_redirect_no_header(skb, net: dev_net(dev: skb->dev), |
1635 | oif: skb->dev->ifindex); |
1636 | return reason; |
1637 | } |
1638 | |
1639 | hdr = (u8 *)ndopts.nd_opts_rh; |
1640 | hdr += 8; |
1641 | if (!pskb_pull(skb, len: hdr - skb_transport_header(skb))) |
1642 | return SKB_DROP_REASON_PKT_TOO_SMALL; |
1643 | |
1644 | return icmpv6_notify(skb, NDISC_REDIRECT, code: 0, info: 0); |
1645 | } |
1646 | |
1647 | static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, |
1648 | struct sk_buff *orig_skb, |
1649 | int rd_len) |
1650 | { |
1651 | u8 *opt = skb_put(skb, len: rd_len); |
1652 | |
1653 | memset(opt, 0, 8); |
1654 | *(opt++) = ND_OPT_REDIRECT_HDR; |
1655 | *(opt++) = (rd_len >> 3); |
1656 | opt += 6; |
1657 | |
1658 | skb_copy_bits(skb: orig_skb, offset: skb_network_offset(skb: orig_skb), to: opt, |
1659 | len: rd_len - 8); |
1660 | } |
1661 | |
1662 | void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) |
1663 | { |
1664 | struct net_device *dev = skb->dev; |
1665 | struct net *net = dev_net(dev); |
1666 | struct sock *sk = net->ipv6.ndisc_sk; |
1667 | int optlen = 0; |
1668 | struct inet_peer *peer; |
1669 | struct sk_buff *buff; |
1670 | struct rd_msg *msg; |
1671 | struct in6_addr saddr_buf; |
1672 | struct rt6_info *rt; |
1673 | struct dst_entry *dst; |
1674 | struct flowi6 fl6; |
1675 | int rd_len; |
1676 | u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, |
1677 | ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; |
1678 | bool ret; |
1679 | |
1680 | if (netif_is_l3_master(dev: skb->dev)) { |
1681 | dev = __dev_get_by_index(net: dev_net(dev: skb->dev), IPCB(skb)->iif); |
1682 | if (!dev) |
1683 | return; |
1684 | } |
1685 | |
1686 | if (ipv6_get_lladdr(dev, addr: &saddr_buf, IFA_F_TENTATIVE)) { |
1687 | ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n" , |
1688 | dev->name); |
1689 | return; |
1690 | } |
1691 | |
1692 | if (!ipv6_addr_equal(a1: &ipv6_hdr(skb)->daddr, a2: target) && |
1693 | ipv6_addr_type(addr: target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { |
1694 | ND_PRINTK(2, warn, |
1695 | "Redirect: target address is not link-local unicast\n" ); |
1696 | return; |
1697 | } |
1698 | |
1699 | icmpv6_flow_init(sk, fl6: &fl6, NDISC_REDIRECT, |
1700 | saddr: &saddr_buf, daddr: &ipv6_hdr(skb)->saddr, oif: dev->ifindex); |
1701 | |
1702 | dst = ip6_route_output(net, NULL, fl6: &fl6); |
1703 | if (dst->error) { |
1704 | dst_release(dst); |
1705 | return; |
1706 | } |
1707 | dst = xfrm_lookup(net, dst_orig: dst, fl: flowi6_to_flowi(fl6: &fl6), NULL, flags: 0); |
1708 | if (IS_ERR(ptr: dst)) |
1709 | return; |
1710 | |
1711 | rt = (struct rt6_info *) dst; |
1712 | |
1713 | if (rt->rt6i_flags & RTF_GATEWAY) { |
1714 | ND_PRINTK(2, warn, |
1715 | "Redirect: destination is not a neighbour\n" ); |
1716 | goto release; |
1717 | } |
1718 | peer = inet_getpeer_v6(base: net->ipv6.peers, v6daddr: &ipv6_hdr(skb)->saddr, create: 1); |
1719 | ret = inet_peer_xrlim_allow(peer, timeout: 1*HZ); |
1720 | if (peer) |
1721 | inet_putpeer(p: peer); |
1722 | if (!ret) |
1723 | goto release; |
1724 | |
1725 | if (dev->addr_len) { |
1726 | struct neighbour *neigh = dst_neigh_lookup(dst: skb_dst(skb), daddr: target); |
1727 | if (!neigh) { |
1728 | ND_PRINTK(2, warn, |
1729 | "Redirect: no neigh for target address\n" ); |
1730 | goto release; |
1731 | } |
1732 | |
1733 | read_lock_bh(&neigh->lock); |
1734 | if (neigh->nud_state & NUD_VALID) { |
1735 | memcpy(ha_buf, neigh->ha, dev->addr_len); |
1736 | read_unlock_bh(&neigh->lock); |
1737 | ha = ha_buf; |
1738 | optlen += ndisc_redirect_opt_addr_space(dev, neigh, |
1739 | ops_data_buf, |
1740 | ops_data: &ops_data); |
1741 | } else |
1742 | read_unlock_bh(&neigh->lock); |
1743 | |
1744 | neigh_release(neigh); |
1745 | } |
1746 | |
1747 | rd_len = min_t(unsigned int, |
1748 | IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, |
1749 | skb->len + 8); |
1750 | rd_len &= ~0x7; |
1751 | optlen += rd_len; |
1752 | |
1753 | buff = ndisc_alloc_skb(dev, len: sizeof(*msg) + optlen); |
1754 | if (!buff) |
1755 | goto release; |
1756 | |
1757 | msg = skb_put(skb: buff, len: sizeof(*msg)); |
1758 | *msg = (struct rd_msg) { |
1759 | .icmph = { |
1760 | .icmp6_type = NDISC_REDIRECT, |
1761 | }, |
1762 | .target = *target, |
1763 | .dest = ipv6_hdr(skb)->daddr, |
1764 | }; |
1765 | |
1766 | /* |
1767 | * include target_address option |
1768 | */ |
1769 | |
1770 | if (ha) |
1771 | ndisc_fill_redirect_addr_option(skb: buff, ha, ops_data); |
1772 | |
1773 | /* |
1774 | * build redirect option and copy skb over to the new packet. |
1775 | */ |
1776 | |
1777 | if (rd_len) |
1778 | ndisc_fill_redirect_hdr_option(skb: buff, orig_skb: skb, rd_len); |
1779 | |
1780 | skb_dst_set(skb: buff, dst); |
1781 | ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); |
1782 | return; |
1783 | |
1784 | release: |
1785 | dst_release(dst); |
1786 | } |
1787 | |
1788 | static void pndisc_redo(struct sk_buff *skb) |
1789 | { |
1790 | enum skb_drop_reason reason = ndisc_recv_ns(skb); |
1791 | |
1792 | kfree_skb_reason(skb, reason); |
1793 | } |
1794 | |
1795 | static int ndisc_is_multicast(const void *pkey) |
1796 | { |
1797 | return ipv6_addr_is_multicast(addr: (struct in6_addr *)pkey); |
1798 | } |
1799 | |
1800 | static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) |
1801 | { |
1802 | struct inet6_dev *idev = __in6_dev_get(dev: skb->dev); |
1803 | |
1804 | if (!idev) |
1805 | return true; |
1806 | if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && |
1807 | idev->cnf.suppress_frag_ndisc) { |
1808 | net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n" ); |
1809 | return true; |
1810 | } |
1811 | return false; |
1812 | } |
1813 | |
1814 | enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) |
1815 | { |
1816 | struct nd_msg *msg; |
1817 | SKB_DR(reason); |
1818 | |
1819 | if (ndisc_suppress_frag_ndisc(skb)) |
1820 | return SKB_DROP_REASON_IPV6_NDISC_FRAG; |
1821 | |
1822 | if (skb_linearize(skb)) |
1823 | return SKB_DROP_REASON_NOMEM; |
1824 | |
1825 | msg = (struct nd_msg *)skb_transport_header(skb); |
1826 | |
1827 | __skb_push(skb, len: skb->data - skb_transport_header(skb)); |
1828 | |
1829 | if (ipv6_hdr(skb)->hop_limit != 255) { |
1830 | ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n" , |
1831 | ipv6_hdr(skb)->hop_limit); |
1832 | return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; |
1833 | } |
1834 | |
1835 | if (msg->icmph.icmp6_code != 0) { |
1836 | ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n" , |
1837 | msg->icmph.icmp6_code); |
1838 | return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; |
1839 | } |
1840 | |
1841 | switch (msg->icmph.icmp6_type) { |
1842 | case NDISC_NEIGHBOUR_SOLICITATION: |
1843 | memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); |
1844 | reason = ndisc_recv_ns(skb); |
1845 | break; |
1846 | |
1847 | case NDISC_NEIGHBOUR_ADVERTISEMENT: |
1848 | reason = ndisc_recv_na(skb); |
1849 | break; |
1850 | |
1851 | case NDISC_ROUTER_SOLICITATION: |
1852 | reason = ndisc_recv_rs(skb); |
1853 | break; |
1854 | |
1855 | case NDISC_ROUTER_ADVERTISEMENT: |
1856 | reason = ndisc_router_discovery(skb); |
1857 | break; |
1858 | |
1859 | case NDISC_REDIRECT: |
1860 | reason = ndisc_redirect_rcv(skb); |
1861 | break; |
1862 | } |
1863 | |
1864 | return reason; |
1865 | } |
1866 | |
1867 | static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) |
1868 | { |
1869 | struct net_device *dev = netdev_notifier_info_to_dev(info: ptr); |
1870 | struct netdev_notifier_change_info *change_info; |
1871 | struct net *net = dev_net(dev); |
1872 | struct inet6_dev *idev; |
1873 | bool evict_nocarrier; |
1874 | |
1875 | switch (event) { |
1876 | case NETDEV_CHANGEADDR: |
1877 | neigh_changeaddr(tbl: &nd_tbl, dev); |
1878 | fib6_run_gc(expires: 0, net, force: false); |
1879 | fallthrough; |
1880 | case NETDEV_UP: |
1881 | idev = in6_dev_get(dev); |
1882 | if (!idev) |
1883 | break; |
1884 | if (idev->cnf.ndisc_notify || |
1885 | net->ipv6.devconf_all->ndisc_notify) |
1886 | ndisc_send_unsol_na(dev); |
1887 | in6_dev_put(idev); |
1888 | break; |
1889 | case NETDEV_CHANGE: |
1890 | idev = in6_dev_get(dev); |
1891 | if (!idev) |
1892 | evict_nocarrier = true; |
1893 | else { |
1894 | evict_nocarrier = idev->cnf.ndisc_evict_nocarrier && |
1895 | net->ipv6.devconf_all->ndisc_evict_nocarrier; |
1896 | in6_dev_put(idev); |
1897 | } |
1898 | |
1899 | change_info = ptr; |
1900 | if (change_info->flags_changed & IFF_NOARP) |
1901 | neigh_changeaddr(tbl: &nd_tbl, dev); |
1902 | if (evict_nocarrier && !netif_carrier_ok(dev)) |
1903 | neigh_carrier_down(tbl: &nd_tbl, dev); |
1904 | break; |
1905 | case NETDEV_DOWN: |
1906 | neigh_ifdown(tbl: &nd_tbl, dev); |
1907 | fib6_run_gc(expires: 0, net, force: false); |
1908 | break; |
1909 | case NETDEV_NOTIFY_PEERS: |
1910 | ndisc_send_unsol_na(dev); |
1911 | break; |
1912 | default: |
1913 | break; |
1914 | } |
1915 | |
1916 | return NOTIFY_DONE; |
1917 | } |
1918 | |
1919 | static struct notifier_block ndisc_netdev_notifier = { |
1920 | .notifier_call = ndisc_netdev_event, |
1921 | .priority = ADDRCONF_NOTIFY_PRIORITY - 5, |
1922 | }; |
1923 | |
1924 | #ifdef CONFIG_SYSCTL |
1925 | static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, |
1926 | const char *func, const char *dev_name) |
1927 | { |
1928 | static char warncomm[TASK_COMM_LEN]; |
1929 | static int warned; |
1930 | if (strcmp(warncomm, current->comm) && warned < 5) { |
1931 | strcpy(p: warncomm, current->comm); |
1932 | pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n" , |
1933 | warncomm, func, |
1934 | dev_name, ctl->procname, |
1935 | dev_name, ctl->procname); |
1936 | warned++; |
1937 | } |
1938 | } |
1939 | |
1940 | int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer, |
1941 | size_t *lenp, loff_t *ppos) |
1942 | { |
1943 | struct net_device *dev = ctl->extra1; |
1944 | struct inet6_dev *idev; |
1945 | int ret; |
1946 | |
1947 | if ((strcmp(ctl->procname, "retrans_time" ) == 0) || |
1948 | (strcmp(ctl->procname, "base_reachable_time" ) == 0)) |
1949 | ndisc_warn_deprecated_sysctl(ctl, func: "syscall" , dev_name: dev ? dev->name : "default" ); |
1950 | |
1951 | if (strcmp(ctl->procname, "retrans_time" ) == 0) |
1952 | ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); |
1953 | |
1954 | else if (strcmp(ctl->procname, "base_reachable_time" ) == 0) |
1955 | ret = neigh_proc_dointvec_jiffies(ctl, write, |
1956 | buffer, lenp, ppos); |
1957 | |
1958 | else if ((strcmp(ctl->procname, "retrans_time_ms" ) == 0) || |
1959 | (strcmp(ctl->procname, "base_reachable_time_ms" ) == 0)) |
1960 | ret = neigh_proc_dointvec_ms_jiffies(ctl, write, |
1961 | buffer, lenp, ppos); |
1962 | else |
1963 | ret = -1; |
1964 | |
1965 | if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { |
1966 | if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) |
1967 | idev->nd_parms->reachable_time = |
1968 | neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); |
1969 | idev->tstamp = jiffies; |
1970 | inet6_ifinfo_notify(RTM_NEWLINK, idev); |
1971 | in6_dev_put(idev); |
1972 | } |
1973 | return ret; |
1974 | } |
1975 | |
1976 | |
1977 | #endif |
1978 | |
1979 | static int __net_init ndisc_net_init(struct net *net) |
1980 | { |
1981 | struct ipv6_pinfo *np; |
1982 | struct sock *sk; |
1983 | int err; |
1984 | |
1985 | err = inet_ctl_sock_create(sk: &sk, PF_INET6, |
1986 | type: SOCK_RAW, IPPROTO_ICMPV6, net); |
1987 | if (err < 0) { |
1988 | ND_PRINTK(0, err, |
1989 | "NDISC: Failed to initialize the control socket (err %d)\n" , |
1990 | err); |
1991 | return err; |
1992 | } |
1993 | |
1994 | net->ipv6.ndisc_sk = sk; |
1995 | |
1996 | np = inet6_sk(sk: sk); |
1997 | np->hop_limit = 255; |
1998 | /* Do not loopback ndisc messages */ |
1999 | inet6_clear_bit(MC6_LOOP, sk); |
2000 | |
2001 | return 0; |
2002 | } |
2003 | |
2004 | static void __net_exit ndisc_net_exit(struct net *net) |
2005 | { |
2006 | inet_ctl_sock_destroy(sk: net->ipv6.ndisc_sk); |
2007 | } |
2008 | |
2009 | static struct pernet_operations ndisc_net_ops = { |
2010 | .init = ndisc_net_init, |
2011 | .exit = ndisc_net_exit, |
2012 | }; |
2013 | |
2014 | int __init ndisc_init(void) |
2015 | { |
2016 | int err; |
2017 | |
2018 | err = register_pernet_subsys(&ndisc_net_ops); |
2019 | if (err) |
2020 | return err; |
2021 | /* |
2022 | * Initialize the neighbour table |
2023 | */ |
2024 | neigh_table_init(index: NEIGH_ND_TABLE, tbl: &nd_tbl); |
2025 | |
2026 | #ifdef CONFIG_SYSCTL |
2027 | err = neigh_sysctl_register(NULL, p: &nd_tbl.parms, |
2028 | proc_handler: ndisc_ifinfo_sysctl_change); |
2029 | if (err) |
2030 | goto out_unregister_pernet; |
2031 | out: |
2032 | #endif |
2033 | return err; |
2034 | |
2035 | #ifdef CONFIG_SYSCTL |
2036 | out_unregister_pernet: |
2037 | unregister_pernet_subsys(&ndisc_net_ops); |
2038 | goto out; |
2039 | #endif |
2040 | } |
2041 | |
2042 | int __init ndisc_late_init(void) |
2043 | { |
2044 | return register_netdevice_notifier(nb: &ndisc_netdev_notifier); |
2045 | } |
2046 | |
2047 | void ndisc_late_cleanup(void) |
2048 | { |
2049 | unregister_netdevice_notifier(nb: &ndisc_netdev_notifier); |
2050 | } |
2051 | |
2052 | void ndisc_cleanup(void) |
2053 | { |
2054 | #ifdef CONFIG_SYSCTL |
2055 | neigh_sysctl_unregister(p: &nd_tbl.parms); |
2056 | #endif |
2057 | neigh_table_clear(index: NEIGH_ND_TABLE, tbl: &nd_tbl); |
2058 | unregister_pernet_subsys(&ndisc_net_ops); |
2059 | } |
2060 | |