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1 | /* |
2 | * Internet Control Message Protocol (ICMPv6) |
3 | * Linux INET6 implementation |
4 | * |
5 | * Authors: |
6 | * Pedro Roque <roque@di.fc.ul.pt> |
7 | * |
8 | * Based on net/ipv4/icmp.c |
9 | * |
10 | * RFC 1885 |
11 | * |
12 | * This program is free software; you can redistribute it and/or |
13 | * modify it under the terms of the GNU General Public License |
14 | * as published by the Free Software Foundation; either version |
15 | * 2 of the License, or (at your option) any later version. |
16 | */ |
17 | |
18 | /* |
19 | * Changes: |
20 | * |
21 | * Andi Kleen : exception handling |
22 | * Andi Kleen add rate limits. never reply to a icmp. |
23 | * add more length checks and other fixes. |
24 | * yoshfuji : ensure to sent parameter problem for |
25 | * fragments. |
26 | * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. |
27 | * Randy Dunlap and |
28 | * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support |
29 | * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data |
30 | */ |
31 | |
32 | #define pr_fmt(fmt) "IPv6: " fmt |
33 | |
34 | #include <linux/module.h> |
35 | #include <linux/errno.h> |
36 | #include <linux/types.h> |
37 | #include <linux/socket.h> |
38 | #include <linux/in.h> |
39 | #include <linux/kernel.h> |
40 | #include <linux/sockios.h> |
41 | #include <linux/net.h> |
42 | #include <linux/skbuff.h> |
43 | #include <linux/init.h> |
44 | #include <linux/netfilter.h> |
45 | #include <linux/slab.h> |
46 | |
47 | #ifdef CONFIG_SYSCTL |
48 | #include <linux/sysctl.h> |
49 | #endif |
50 | |
51 | #include <linux/inet.h> |
52 | #include <linux/netdevice.h> |
53 | #include <linux/icmpv6.h> |
54 | |
55 | #include <net/ip.h> |
56 | #include <net/sock.h> |
57 | |
58 | #include <net/ipv6.h> |
59 | #include <net/ip6_checksum.h> |
60 | #include <net/ping.h> |
61 | #include <net/protocol.h> |
62 | #include <net/raw.h> |
63 | #include <net/rawv6.h> |
64 | #include <net/transp_v6.h> |
65 | #include <net/ip6_route.h> |
66 | #include <net/addrconf.h> |
67 | #include <net/icmp.h> |
68 | #include <net/xfrm.h> |
69 | #include <net/inet_common.h> |
70 | |
71 | #include <asm/uaccess.h> |
72 | |
73 | /* |
74 | * The ICMP socket(s). This is the most convenient way to flow control |
75 | * our ICMP output as well as maintain a clean interface throughout |
76 | * all layers. All Socketless IP sends will soon be gone. |
77 | * |
78 | * On SMP we have one ICMP socket per-cpu. |
79 | */ |
80 | static inline struct sock *icmpv6_sk(struct net *net) |
81 | { |
82 | return net->ipv6.icmp_sk[smp_processor_id()]; |
83 | } |
84 | |
85 | static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
86 | u8 type, u8 code, int offset, __be32 info) |
87 | { |
88 | /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */ |
89 | struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset); |
90 | struct net *net = dev_net(skb->dev); |
91 | |
92 | if (type == ICMPV6_PKT_TOOBIG) |
93 | ip6_update_pmtu(skb, net, info, 0, 0); |
94 | else if (type == NDISC_REDIRECT) |
95 | ip6_redirect(skb, net, skb->dev->ifindex, 0); |
96 | |
97 | if (!(type & ICMPV6_INFOMSG_MASK)) |
98 | if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST) |
99 | ping_err(skb, offset, info); |
100 | } |
101 | |
102 | static int icmpv6_rcv(struct sk_buff *skb); |
103 | |
104 | static const struct inet6_protocol icmpv6_protocol = { |
105 | .handler = icmpv6_rcv, |
106 | .err_handler = icmpv6_err, |
107 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
108 | }; |
109 | |
110 | static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) |
111 | { |
112 | struct sock *sk; |
113 | |
114 | local_bh_disable(); |
115 | |
116 | sk = icmpv6_sk(net); |
117 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
118 | /* This can happen if the output path (f.e. SIT or |
119 | * ip6ip6 tunnel) signals dst_link_failure() for an |
120 | * outgoing ICMP6 packet. |
121 | */ |
122 | local_bh_enable(); |
123 | return NULL; |
124 | } |
125 | return sk; |
126 | } |
127 | |
128 | static __inline__ void icmpv6_xmit_unlock(struct sock *sk) |
129 | { |
130 | spin_unlock_bh(&sk->sk_lock.slock); |
131 | } |
132 | |
133 | /* |
134 | * Figure out, may we reply to this packet with icmp error. |
135 | * |
136 | * We do not reply, if: |
137 | * - it was icmp error message. |
138 | * - it is truncated, so that it is known, that protocol is ICMPV6 |
139 | * (i.e. in the middle of some exthdr) |
140 | * |
141 | * --ANK (980726) |
142 | */ |
143 | |
144 | static bool is_ineligible(const struct sk_buff *skb) |
145 | { |
146 | int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
147 | int len = skb->len - ptr; |
148 | __u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
149 | __be16 frag_off; |
150 | |
151 | if (len < 0) |
152 | return true; |
153 | |
154 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); |
155 | if (ptr < 0) |
156 | return false; |
157 | if (nexthdr == IPPROTO_ICMPV6) { |
158 | u8 _type, *tp; |
159 | tp = skb_header_pointer(skb, |
160 | ptr+offsetof(struct icmp6hdr, icmp6_type), |
161 | sizeof(_type), &_type); |
162 | if (tp == NULL || |
163 | !(*tp & ICMPV6_INFOMSG_MASK)) |
164 | return true; |
165 | } |
166 | return false; |
167 | } |
168 | |
169 | /* |
170 | * Check the ICMP output rate limit |
171 | */ |
172 | static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type, |
173 | struct flowi6 *fl6) |
174 | { |
175 | struct dst_entry *dst; |
176 | struct net *net = sock_net(sk); |
177 | bool res = false; |
178 | |
179 | /* Informational messages are not limited. */ |
180 | if (type & ICMPV6_INFOMSG_MASK) |
181 | return true; |
182 | |
183 | /* Do not limit pmtu discovery, it would break it. */ |
184 | if (type == ICMPV6_PKT_TOOBIG) |
185 | return true; |
186 | |
187 | /* |
188 | * Look up the output route. |
189 | * XXX: perhaps the expire for routing entries cloned by |
190 | * this lookup should be more aggressive (not longer than timeout). |
191 | */ |
192 | dst = ip6_route_output(net, sk, fl6); |
193 | if (dst->error) { |
194 | IP6_INC_STATS(net, ip6_dst_idev(dst), |
195 | IPSTATS_MIB_OUTNOROUTES); |
196 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
197 | res = true; |
198 | } else { |
199 | struct rt6_info *rt = (struct rt6_info *)dst; |
200 | int tmo = net->ipv6.sysctl.icmpv6_time; |
201 | struct inet_peer *peer; |
202 | |
203 | /* Give more bandwidth to wider prefixes. */ |
204 | if (rt->rt6i_dst.plen < 128) |
205 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); |
206 | |
207 | peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); |
208 | res = inet_peer_xrlim_allow(peer, tmo); |
209 | if (peer) |
210 | inet_putpeer(peer); |
211 | } |
212 | dst_release(dst); |
213 | return res; |
214 | } |
215 | |
216 | /* |
217 | * an inline helper for the "simple" if statement below |
218 | * checks if parameter problem report is caused by an |
219 | * unrecognized IPv6 option that has the Option Type |
220 | * highest-order two bits set to 10 |
221 | */ |
222 | |
223 | static bool opt_unrec(struct sk_buff *skb, __u32 offset) |
224 | { |
225 | u8 _optval, *op; |
226 | |
227 | offset += skb_network_offset(skb); |
228 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
229 | if (op == NULL) |
230 | return true; |
231 | return (*op & 0xC0) == 0x80; |
232 | } |
233 | |
234 | int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, |
235 | struct icmp6hdr *thdr, int len) |
236 | { |
237 | struct sk_buff *skb; |
238 | struct icmp6hdr *icmp6h; |
239 | int err = 0; |
240 | |
241 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) |
242 | goto out; |
243 | |
244 | icmp6h = icmp6_hdr(skb); |
245 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
246 | icmp6h->icmp6_cksum = 0; |
247 | |
248 | if (skb_queue_len(&sk->sk_write_queue) == 1) { |
249 | skb->csum = csum_partial(icmp6h, |
250 | sizeof(struct icmp6hdr), skb->csum); |
251 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
252 | &fl6->daddr, |
253 | len, fl6->flowi6_proto, |
254 | skb->csum); |
255 | } else { |
256 | __wsum tmp_csum = 0; |
257 | |
258 | skb_queue_walk(&sk->sk_write_queue, skb) { |
259 | tmp_csum = csum_add(tmp_csum, skb->csum); |
260 | } |
261 | |
262 | tmp_csum = csum_partial(icmp6h, |
263 | sizeof(struct icmp6hdr), tmp_csum); |
264 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
265 | &fl6->daddr, |
266 | len, fl6->flowi6_proto, |
267 | tmp_csum); |
268 | } |
269 | ip6_push_pending_frames(sk); |
270 | out: |
271 | return err; |
272 | } |
273 | |
274 | struct icmpv6_msg { |
275 | struct sk_buff *skb; |
276 | int offset; |
277 | uint8_t type; |
278 | }; |
279 | |
280 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) |
281 | { |
282 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; |
283 | struct sk_buff *org_skb = msg->skb; |
284 | __wsum csum = 0; |
285 | |
286 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, |
287 | to, len, csum); |
288 | skb->csum = csum_block_add(skb->csum, csum, odd); |
289 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
290 | nf_ct_attach(skb, org_skb); |
291 | return 0; |
292 | } |
293 | |
294 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
295 | static void mip6_addr_swap(struct sk_buff *skb) |
296 | { |
297 | struct ipv6hdr *iph = ipv6_hdr(skb); |
298 | struct inet6_skb_parm *opt = IP6CB(skb); |
299 | struct ipv6_destopt_hao *hao; |
300 | struct in6_addr tmp; |
301 | int off; |
302 | |
303 | if (opt->dsthao) { |
304 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); |
305 | if (likely(off >= 0)) { |
306 | hao = (struct ipv6_destopt_hao *) |
307 | (skb_network_header(skb) + off); |
308 | tmp = iph->saddr; |
309 | iph->saddr = hao->addr; |
310 | hao->addr = tmp; |
311 | } |
312 | } |
313 | } |
314 | #else |
315 | static inline void mip6_addr_swap(struct sk_buff *skb) {} |
316 | #endif |
317 | |
318 | struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb, |
319 | struct sock *sk, struct flowi6 *fl6) |
320 | { |
321 | struct dst_entry *dst, *dst2; |
322 | struct flowi6 fl2; |
323 | int err; |
324 | |
325 | err = ip6_dst_lookup(sk, &dst, fl6); |
326 | if (err) |
327 | return ERR_PTR(err); |
328 | |
329 | /* |
330 | * We won't send icmp if the destination is known |
331 | * anycast. |
332 | */ |
333 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { |
334 | LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: acast source\n"); |
335 | dst_release(dst); |
336 | return ERR_PTR(-EINVAL); |
337 | } |
338 | |
339 | /* No need to clone since we're just using its address. */ |
340 | dst2 = dst; |
341 | |
342 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); |
343 | if (!IS_ERR(dst)) { |
344 | if (dst != dst2) |
345 | return dst; |
346 | } else { |
347 | if (PTR_ERR(dst) == -EPERM) |
348 | dst = NULL; |
349 | else |
350 | return dst; |
351 | } |
352 | |
353 | err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6); |
354 | if (err) |
355 | goto relookup_failed; |
356 | |
357 | err = ip6_dst_lookup(sk, &dst2, &fl2); |
358 | if (err) |
359 | goto relookup_failed; |
360 | |
361 | dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); |
362 | if (!IS_ERR(dst2)) { |
363 | dst_release(dst); |
364 | dst = dst2; |
365 | } else { |
366 | err = PTR_ERR(dst2); |
367 | if (err == -EPERM) { |
368 | dst_release(dst); |
369 | return dst2; |
370 | } else |
371 | goto relookup_failed; |
372 | } |
373 | |
374 | relookup_failed: |
375 | if (dst) |
376 | return dst; |
377 | return ERR_PTR(err); |
378 | } |
379 | |
380 | /* |
381 | * Send an ICMP message in response to a packet in error |
382 | */ |
383 | static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) |
384 | { |
385 | struct net *net = dev_net(skb->dev); |
386 | struct inet6_dev *idev = NULL; |
387 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
388 | struct sock *sk; |
389 | struct ipv6_pinfo *np; |
390 | const struct in6_addr *saddr = NULL; |
391 | struct dst_entry *dst; |
392 | struct icmp6hdr tmp_hdr; |
393 | struct flowi6 fl6; |
394 | struct icmpv6_msg msg; |
395 | int iif = 0; |
396 | int addr_type = 0; |
397 | int len; |
398 | int hlimit; |
399 | int err = 0; |
400 | |
401 | if ((u8 *)hdr < skb->head || |
402 | (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb)) |
403 | return; |
404 | |
405 | /* |
406 | * Make sure we respect the rules |
407 | * i.e. RFC 1885 2.4(e) |
408 | * Rule (e.1) is enforced by not using icmp6_send |
409 | * in any code that processes icmp errors. |
410 | */ |
411 | addr_type = ipv6_addr_type(&hdr->daddr); |
412 | |
413 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0)) |
414 | saddr = &hdr->daddr; |
415 | |
416 | /* |
417 | * Dest addr check |
418 | */ |
419 | |
420 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { |
421 | if (type != ICMPV6_PKT_TOOBIG && |
422 | !(type == ICMPV6_PARAMPROB && |
423 | code == ICMPV6_UNK_OPTION && |
424 | (opt_unrec(skb, info)))) |
425 | return; |
426 | |
427 | saddr = NULL; |
428 | } |
429 | |
430 | addr_type = ipv6_addr_type(&hdr->saddr); |
431 | |
432 | /* |
433 | * Source addr check |
434 | */ |
435 | |
436 | if (__ipv6_addr_needs_scope_id(addr_type)) |
437 | iif = skb->dev->ifindex; |
438 | |
439 | /* |
440 | * Must not send error if the source does not uniquely |
441 | * identify a single node (RFC2463 Section 2.4). |
442 | * We check unspecified / multicast addresses here, |
443 | * and anycast addresses will be checked later. |
444 | */ |
445 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { |
446 | LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: addr_any/mcast source\n"); |
447 | return; |
448 | } |
449 | |
450 | /* |
451 | * Never answer to a ICMP packet. |
452 | */ |
453 | if (is_ineligible(skb)) { |
454 | LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: no reply to icmp error\n"); |
455 | return; |
456 | } |
457 | |
458 | mip6_addr_swap(skb); |
459 | |
460 | memset(&fl6, 0, sizeof(fl6)); |
461 | fl6.flowi6_proto = IPPROTO_ICMPV6; |
462 | fl6.daddr = hdr->saddr; |
463 | if (saddr) |
464 | fl6.saddr = *saddr; |
465 | fl6.flowi6_oif = iif; |
466 | fl6.fl6_icmp_type = type; |
467 | fl6.fl6_icmp_code = code; |
468 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
469 | |
470 | sk = icmpv6_xmit_lock(net); |
471 | if (sk == NULL) |
472 | return; |
473 | np = inet6_sk(sk); |
474 | |
475 | if (!icmpv6_xrlim_allow(sk, type, &fl6)) |
476 | goto out; |
477 | |
478 | tmp_hdr.icmp6_type = type; |
479 | tmp_hdr.icmp6_code = code; |
480 | tmp_hdr.icmp6_cksum = 0; |
481 | tmp_hdr.icmp6_pointer = htonl(info); |
482 | |
483 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
484 | fl6.flowi6_oif = np->mcast_oif; |
485 | else if (!fl6.flowi6_oif) |
486 | fl6.flowi6_oif = np->ucast_oif; |
487 | |
488 | dst = icmpv6_route_lookup(net, skb, sk, &fl6); |
489 | if (IS_ERR(dst)) |
490 | goto out; |
491 | |
492 | if (ipv6_addr_is_multicast(&fl6.daddr)) |
493 | hlimit = np->mcast_hops; |
494 | else |
495 | hlimit = np->hop_limit; |
496 | if (hlimit < 0) |
497 | hlimit = ip6_dst_hoplimit(dst); |
498 | |
499 | msg.skb = skb; |
500 | msg.offset = skb_network_offset(skb); |
501 | msg.type = type; |
502 | |
503 | len = skb->len - msg.offset; |
504 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); |
505 | if (len < 0) { |
506 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
507 | goto out_dst_release; |
508 | } |
509 | |
510 | rcu_read_lock(); |
511 | idev = __in6_dev_get(skb->dev); |
512 | |
513 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, |
514 | len + sizeof(struct icmp6hdr), |
515 | sizeof(struct icmp6hdr), hlimit, |
516 | np->tclass, NULL, &fl6, (struct rt6_info *)dst, |
517 | MSG_DONTWAIT, np->dontfrag); |
518 | if (err) { |
519 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
520 | ip6_flush_pending_frames(sk); |
521 | } else { |
522 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, |
523 | len + sizeof(struct icmp6hdr)); |
524 | } |
525 | rcu_read_unlock(); |
526 | out_dst_release: |
527 | dst_release(dst); |
528 | out: |
529 | icmpv6_xmit_unlock(sk); |
530 | } |
531 | |
532 | /* Slightly more convenient version of icmp6_send. |
533 | */ |
534 | void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) |
535 | { |
536 | icmp6_send(skb, ICMPV6_PARAMPROB, code, pos); |
537 | kfree_skb(skb); |
538 | } |
539 | |
540 | static void icmpv6_echo_reply(struct sk_buff *skb) |
541 | { |
542 | struct net *net = dev_net(skb->dev); |
543 | struct sock *sk; |
544 | struct inet6_dev *idev; |
545 | struct ipv6_pinfo *np; |
546 | const struct in6_addr *saddr = NULL; |
547 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
548 | struct icmp6hdr tmp_hdr; |
549 | struct flowi6 fl6; |
550 | struct icmpv6_msg msg; |
551 | struct dst_entry *dst; |
552 | int err = 0; |
553 | int hlimit; |
554 | |
555 | saddr = &ipv6_hdr(skb)->daddr; |
556 | |
557 | if (!ipv6_unicast_destination(skb)) |
558 | saddr = NULL; |
559 | |
560 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); |
561 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; |
562 | |
563 | memset(&fl6, 0, sizeof(fl6)); |
564 | fl6.flowi6_proto = IPPROTO_ICMPV6; |
565 | fl6.daddr = ipv6_hdr(skb)->saddr; |
566 | if (saddr) |
567 | fl6.saddr = *saddr; |
568 | fl6.flowi6_oif = skb->dev->ifindex; |
569 | fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; |
570 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
571 | |
572 | sk = icmpv6_xmit_lock(net); |
573 | if (sk == NULL) |
574 | return; |
575 | np = inet6_sk(sk); |
576 | |
577 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
578 | fl6.flowi6_oif = np->mcast_oif; |
579 | else if (!fl6.flowi6_oif) |
580 | fl6.flowi6_oif = np->ucast_oif; |
581 | |
582 | err = ip6_dst_lookup(sk, &dst, &fl6); |
583 | if (err) |
584 | goto out; |
585 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); |
586 | if (IS_ERR(dst)) |
587 | goto out; |
588 | |
589 | if (ipv6_addr_is_multicast(&fl6.daddr)) |
590 | hlimit = np->mcast_hops; |
591 | else |
592 | hlimit = np->hop_limit; |
593 | if (hlimit < 0) |
594 | hlimit = ip6_dst_hoplimit(dst); |
595 | |
596 | idev = __in6_dev_get(skb->dev); |
597 | |
598 | msg.skb = skb; |
599 | msg.offset = 0; |
600 | msg.type = ICMPV6_ECHO_REPLY; |
601 | |
602 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), |
603 | sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6, |
604 | (struct rt6_info *)dst, MSG_DONTWAIT, |
605 | np->dontfrag); |
606 | |
607 | if (err) { |
608 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
609 | ip6_flush_pending_frames(sk); |
610 | } else { |
611 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, |
612 | skb->len + sizeof(struct icmp6hdr)); |
613 | } |
614 | dst_release(dst); |
615 | out: |
616 | icmpv6_xmit_unlock(sk); |
617 | } |
618 | |
619 | void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) |
620 | { |
621 | const struct inet6_protocol *ipprot; |
622 | int inner_offset; |
623 | __be16 frag_off; |
624 | u8 nexthdr; |
625 | |
626 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
627 | return; |
628 | |
629 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; |
630 | if (ipv6_ext_hdr(nexthdr)) { |
631 | /* now skip over extension headers */ |
632 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), |
633 | &nexthdr, &frag_off); |
634 | if (inner_offset<0) |
635 | return; |
636 | } else { |
637 | inner_offset = sizeof(struct ipv6hdr); |
638 | } |
639 | |
640 | /* Checkin header including 8 bytes of inner protocol header. */ |
641 | if (!pskb_may_pull(skb, inner_offset+8)) |
642 | return; |
643 | |
644 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
645 | Without this we will not able f.e. to make source routed |
646 | pmtu discovery. |
647 | Corresponding argument (opt) to notifiers is already added. |
648 | --ANK (980726) |
649 | */ |
650 | |
651 | rcu_read_lock(); |
652 | ipprot = rcu_dereference(inet6_protos[nexthdr]); |
653 | if (ipprot && ipprot->err_handler) |
654 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); |
655 | rcu_read_unlock(); |
656 | |
657 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
658 | } |
659 | |
660 | /* |
661 | * Handle icmp messages |
662 | */ |
663 | |
664 | static int icmpv6_rcv(struct sk_buff *skb) |
665 | { |
666 | struct net_device *dev = skb->dev; |
667 | struct inet6_dev *idev = __in6_dev_get(dev); |
668 | const struct in6_addr *saddr, *daddr; |
669 | struct icmp6hdr *hdr; |
670 | u8 type; |
671 | |
672 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
673 | struct sec_path *sp = skb_sec_path(skb); |
674 | int nh; |
675 | |
676 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
677 | XFRM_STATE_ICMP)) |
678 | goto drop_no_count; |
679 | |
680 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr))) |
681 | goto drop_no_count; |
682 | |
683 | nh = skb_network_offset(skb); |
684 | skb_set_network_header(skb, sizeof(*hdr)); |
685 | |
686 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) |
687 | goto drop_no_count; |
688 | |
689 | skb_set_network_header(skb, nh); |
690 | } |
691 | |
692 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); |
693 | |
694 | saddr = &ipv6_hdr(skb)->saddr; |
695 | daddr = &ipv6_hdr(skb)->daddr; |
696 | |
697 | /* Perform checksum. */ |
698 | switch (skb->ip_summed) { |
699 | case CHECKSUM_COMPLETE: |
700 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
701 | skb->csum)) |
702 | break; |
703 | /* fall through */ |
704 | case CHECKSUM_NONE: |
705 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
706 | IPPROTO_ICMPV6, 0)); |
707 | if (__skb_checksum_complete(skb)) { |
708 | LIMIT_NETDEBUG(KERN_DEBUG |
709 | "ICMPv6 checksum failed [%pI6c > %pI6c]\n", |
710 | saddr, daddr); |
711 | goto csum_error; |
712 | } |
713 | } |
714 | |
715 | if (!pskb_pull(skb, sizeof(*hdr))) |
716 | goto discard_it; |
717 | |
718 | hdr = icmp6_hdr(skb); |
719 | |
720 | type = hdr->icmp6_type; |
721 | |
722 | ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); |
723 | |
724 | switch (type) { |
725 | case ICMPV6_ECHO_REQUEST: |
726 | icmpv6_echo_reply(skb); |
727 | break; |
728 | |
729 | case ICMPV6_ECHO_REPLY: |
730 | ping_rcv(skb); |
731 | break; |
732 | |
733 | case ICMPV6_PKT_TOOBIG: |
734 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update |
735 | standard destination cache. Seems, only "advanced" |
736 | destination cache will allow to solve this problem |
737 | --ANK (980726) |
738 | */ |
739 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
740 | goto discard_it; |
741 | hdr = icmp6_hdr(skb); |
742 | |
743 | /* |
744 | * Drop through to notify |
745 | */ |
746 | |
747 | case ICMPV6_DEST_UNREACH: |
748 | case ICMPV6_TIME_EXCEED: |
749 | case ICMPV6_PARAMPROB: |
750 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); |
751 | break; |
752 | |
753 | case NDISC_ROUTER_SOLICITATION: |
754 | case NDISC_ROUTER_ADVERTISEMENT: |
755 | case NDISC_NEIGHBOUR_SOLICITATION: |
756 | case NDISC_NEIGHBOUR_ADVERTISEMENT: |
757 | case NDISC_REDIRECT: |
758 | ndisc_rcv(skb); |
759 | break; |
760 | |
761 | case ICMPV6_MGM_QUERY: |
762 | igmp6_event_query(skb); |
763 | break; |
764 | |
765 | case ICMPV6_MGM_REPORT: |
766 | igmp6_event_report(skb); |
767 | break; |
768 | |
769 | case ICMPV6_MGM_REDUCTION: |
770 | case ICMPV6_NI_QUERY: |
771 | case ICMPV6_NI_REPLY: |
772 | case ICMPV6_MLD2_REPORT: |
773 | case ICMPV6_DHAAD_REQUEST: |
774 | case ICMPV6_DHAAD_REPLY: |
775 | case ICMPV6_MOBILE_PREFIX_SOL: |
776 | case ICMPV6_MOBILE_PREFIX_ADV: |
777 | break; |
778 | |
779 | default: |
780 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
781 | |
782 | /* informational */ |
783 | if (type & ICMPV6_INFOMSG_MASK) |
784 | break; |
785 | |
786 | /* |
787 | * error of unknown type. |
788 | * must pass to upper level |
789 | */ |
790 | |
791 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); |
792 | } |
793 | |
794 | kfree_skb(skb); |
795 | return 0; |
796 | |
797 | csum_error: |
798 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS); |
799 | discard_it: |
800 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); |
801 | drop_no_count: |
802 | kfree_skb(skb); |
803 | return 0; |
804 | } |
805 | |
806 | void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6, |
807 | u8 type, |
808 | const struct in6_addr *saddr, |
809 | const struct in6_addr *daddr, |
810 | int oif) |
811 | { |
812 | memset(fl6, 0, sizeof(*fl6)); |
813 | fl6->saddr = *saddr; |
814 | fl6->daddr = *daddr; |
815 | fl6->flowi6_proto = IPPROTO_ICMPV6; |
816 | fl6->fl6_icmp_type = type; |
817 | fl6->fl6_icmp_code = 0; |
818 | fl6->flowi6_oif = oif; |
819 | security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); |
820 | } |
821 | |
822 | /* |
823 | * Special lock-class for __icmpv6_sk: |
824 | */ |
825 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; |
826 | |
827 | static int __net_init icmpv6_sk_init(struct net *net) |
828 | { |
829 | struct sock *sk; |
830 | int err, i, j; |
831 | |
832 | net->ipv6.icmp_sk = |
833 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); |
834 | if (net->ipv6.icmp_sk == NULL) |
835 | return -ENOMEM; |
836 | |
837 | for_each_possible_cpu(i) { |
838 | err = inet_ctl_sock_create(&sk, PF_INET6, |
839 | SOCK_RAW, IPPROTO_ICMPV6, net); |
840 | if (err < 0) { |
841 | pr_err("Failed to initialize the ICMP6 control socket (err %d)\n", |
842 | err); |
843 | goto fail; |
844 | } |
845 | |
846 | net->ipv6.icmp_sk[i] = sk; |
847 | |
848 | /* |
849 | * Split off their lock-class, because sk->sk_dst_lock |
850 | * gets used from softirqs, which is safe for |
851 | * __icmpv6_sk (because those never get directly used |
852 | * via userspace syscalls), but unsafe for normal sockets. |
853 | */ |
854 | lockdep_set_class(&sk->sk_dst_lock, |
855 | &icmpv6_socket_sk_dst_lock_key); |
856 | |
857 | /* Enough space for 2 64K ICMP packets, including |
858 | * sk_buff struct overhead. |
859 | */ |
860 | sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); |
861 | } |
862 | return 0; |
863 | |
864 | fail: |
865 | for (j = 0; j < i; j++) |
866 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); |
867 | kfree(net->ipv6.icmp_sk); |
868 | return err; |
869 | } |
870 | |
871 | static void __net_exit icmpv6_sk_exit(struct net *net) |
872 | { |
873 | int i; |
874 | |
875 | for_each_possible_cpu(i) { |
876 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); |
877 | } |
878 | kfree(net->ipv6.icmp_sk); |
879 | } |
880 | |
881 | static struct pernet_operations icmpv6_sk_ops = { |
882 | .init = icmpv6_sk_init, |
883 | .exit = icmpv6_sk_exit, |
884 | }; |
885 | |
886 | int __init icmpv6_init(void) |
887 | { |
888 | int err; |
889 | |
890 | err = register_pernet_subsys(&icmpv6_sk_ops); |
891 | if (err < 0) |
892 | return err; |
893 | |
894 | err = -EAGAIN; |
895 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) |
896 | goto fail; |
897 | |
898 | err = inet6_register_icmp_sender(icmp6_send); |
899 | if (err) |
900 | goto sender_reg_err; |
901 | return 0; |
902 | |
903 | sender_reg_err: |
904 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
905 | fail: |
906 | pr_err("Failed to register ICMP6 protocol\n"); |
907 | unregister_pernet_subsys(&icmpv6_sk_ops); |
908 | return err; |
909 | } |
910 | |
911 | void icmpv6_cleanup(void) |
912 | { |
913 | inet6_unregister_icmp_sender(icmp6_send); |
914 | unregister_pernet_subsys(&icmpv6_sk_ops); |
915 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
916 | } |
917 | |
918 | |
919 | static const struct icmp6_err { |
920 | int err; |
921 | int fatal; |
922 | } tab_unreach[] = { |
923 | { /* NOROUTE */ |
924 | .err = ENETUNREACH, |
925 | .fatal = 0, |
926 | }, |
927 | { /* ADM_PROHIBITED */ |
928 | .err = EACCES, |
929 | .fatal = 1, |
930 | }, |
931 | { /* Was NOT_NEIGHBOUR, now reserved */ |
932 | .err = EHOSTUNREACH, |
933 | .fatal = 0, |
934 | }, |
935 | { /* ADDR_UNREACH */ |
936 | .err = EHOSTUNREACH, |
937 | .fatal = 0, |
938 | }, |
939 | { /* PORT_UNREACH */ |
940 | .err = ECONNREFUSED, |
941 | .fatal = 1, |
942 | }, |
943 | { /* POLICY_FAIL */ |
944 | .err = EACCES, |
945 | .fatal = 1, |
946 | }, |
947 | { /* REJECT_ROUTE */ |
948 | .err = EACCES, |
949 | .fatal = 1, |
950 | }, |
951 | }; |
952 | |
953 | int icmpv6_err_convert(u8 type, u8 code, int *err) |
954 | { |
955 | int fatal = 0; |
956 | |
957 | *err = EPROTO; |
958 | |
959 | switch (type) { |
960 | case ICMPV6_DEST_UNREACH: |
961 | fatal = 1; |
962 | if (code < ARRAY_SIZE(tab_unreach)) { |
963 | *err = tab_unreach[code].err; |
964 | fatal = tab_unreach[code].fatal; |
965 | } |
966 | break; |
967 | |
968 | case ICMPV6_PKT_TOOBIG: |
969 | *err = EMSGSIZE; |
970 | break; |
971 | |
972 | case ICMPV6_PARAMPROB: |
973 | *err = EPROTO; |
974 | fatal = 1; |
975 | break; |
976 | |
977 | case ICMPV6_TIME_EXCEED: |
978 | *err = EHOSTUNREACH; |
979 | break; |
980 | } |
981 | |
982 | return fatal; |
983 | } |
984 | EXPORT_SYMBOL(icmpv6_err_convert); |
985 | |
986 | #ifdef CONFIG_SYSCTL |
987 | struct ctl_table ipv6_icmp_table_template[] = { |
988 | { |
989 | .procname = "ratelimit", |
990 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
991 | .maxlen = sizeof(int), |
992 | .mode = 0644, |
993 | .proc_handler = proc_dointvec_ms_jiffies, |
994 | }, |
995 | { }, |
996 | }; |
997 | |
998 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
999 | { |
1000 | struct ctl_table *table; |
1001 | |
1002 | table = kmemdup(ipv6_icmp_table_template, |
1003 | sizeof(ipv6_icmp_table_template), |
1004 | GFP_KERNEL); |
1005 | |
1006 | if (table) |
1007 | table[0].data = &net->ipv6.sysctl.icmpv6_time; |
1008 | |
1009 | return table; |
1010 | } |
1011 | #endif |
1012 | |
1013 |
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