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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 | #include <linux/module.h> |
33 | #include <linux/errno.h> |
34 | #include <linux/types.h> |
35 | #include <linux/socket.h> |
36 | #include <linux/in.h> |
37 | #include <linux/kernel.h> |
38 | #include <linux/sockios.h> |
39 | #include <linux/net.h> |
40 | #include <linux/skbuff.h> |
41 | #include <linux/init.h> |
42 | #include <linux/netfilter.h> |
43 | #include <linux/slab.h> |
44 | |
45 | #ifdef CONFIG_SYSCTL |
46 | #include <linux/sysctl.h> |
47 | #endif |
48 | |
49 | #include <linux/inet.h> |
50 | #include <linux/netdevice.h> |
51 | #include <linux/icmpv6.h> |
52 | |
53 | #include <net/ip.h> |
54 | #include <net/sock.h> |
55 | |
56 | #include <net/ipv6.h> |
57 | #include <net/ip6_checksum.h> |
58 | #include <net/protocol.h> |
59 | #include <net/raw.h> |
60 | #include <net/rawv6.h> |
61 | #include <net/transp_v6.h> |
62 | #include <net/ip6_route.h> |
63 | #include <net/addrconf.h> |
64 | #include <net/icmp.h> |
65 | #include <net/xfrm.h> |
66 | #include <net/inet_common.h> |
67 | |
68 | #include <asm/uaccess.h> |
69 | #include <asm/system.h> |
70 | |
71 | /* |
72 | * The ICMP socket(s). This is the most convenient way to flow control |
73 | * our ICMP output as well as maintain a clean interface throughout |
74 | * all layers. All Socketless IP sends will soon be gone. |
75 | * |
76 | * On SMP we have one ICMP socket per-cpu. |
77 | */ |
78 | static inline struct sock *icmpv6_sk(struct net *net) |
79 | { |
80 | return net->ipv6.icmp_sk[smp_processor_id()]; |
81 | } |
82 | |
83 | static int icmpv6_rcv(struct sk_buff *skb); |
84 | |
85 | static const struct inet6_protocol icmpv6_protocol = { |
86 | .handler = icmpv6_rcv, |
87 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
88 | }; |
89 | |
90 | static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) |
91 | { |
92 | struct sock *sk; |
93 | |
94 | local_bh_disable(); |
95 | |
96 | sk = icmpv6_sk(net); |
97 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
98 | /* This can happen if the output path (f.e. SIT or |
99 | * ip6ip6 tunnel) signals dst_link_failure() for an |
100 | * outgoing ICMP6 packet. |
101 | */ |
102 | local_bh_enable(); |
103 | return NULL; |
104 | } |
105 | return sk; |
106 | } |
107 | |
108 | static __inline__ void icmpv6_xmit_unlock(struct sock *sk) |
109 | { |
110 | spin_unlock_bh(&sk->sk_lock.slock); |
111 | } |
112 | |
113 | /* |
114 | * Slightly more convenient version of icmpv6_send. |
115 | */ |
116 | void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) |
117 | { |
118 | icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos); |
119 | kfree_skb(skb); |
120 | } |
121 | |
122 | /* |
123 | * Figure out, may we reply to this packet with icmp error. |
124 | * |
125 | * We do not reply, if: |
126 | * - it was icmp error message. |
127 | * - it is truncated, so that it is known, that protocol is ICMPV6 |
128 | * (i.e. in the middle of some exthdr) |
129 | * |
130 | * --ANK (980726) |
131 | */ |
132 | |
133 | static int is_ineligible(struct sk_buff *skb) |
134 | { |
135 | int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
136 | int len = skb->len - ptr; |
137 | __u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
138 | |
139 | if (len < 0) |
140 | return 1; |
141 | |
142 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr); |
143 | if (ptr < 0) |
144 | return 0; |
145 | if (nexthdr == IPPROTO_ICMPV6) { |
146 | u8 _type, *tp; |
147 | tp = skb_header_pointer(skb, |
148 | ptr+offsetof(struct icmp6hdr, icmp6_type), |
149 | sizeof(_type), &_type); |
150 | if (tp == NULL || |
151 | !(*tp & ICMPV6_INFOMSG_MASK)) |
152 | return 1; |
153 | } |
154 | return 0; |
155 | } |
156 | |
157 | /* |
158 | * Check the ICMP output rate limit |
159 | */ |
160 | static inline int icmpv6_xrlim_allow(struct sock *sk, u8 type, |
161 | struct flowi *fl) |
162 | { |
163 | struct dst_entry *dst; |
164 | struct net *net = sock_net(sk); |
165 | int res = 0; |
166 | |
167 | /* Informational messages are not limited. */ |
168 | if (type & ICMPV6_INFOMSG_MASK) |
169 | return 1; |
170 | |
171 | /* Do not limit pmtu discovery, it would break it. */ |
172 | if (type == ICMPV6_PKT_TOOBIG) |
173 | return 1; |
174 | |
175 | /* |
176 | * Look up the output route. |
177 | * XXX: perhaps the expire for routing entries cloned by |
178 | * this lookup should be more aggressive (not longer than timeout). |
179 | */ |
180 | dst = ip6_route_output(net, sk, fl); |
181 | if (dst->error) { |
182 | IP6_INC_STATS(net, ip6_dst_idev(dst), |
183 | IPSTATS_MIB_OUTNOROUTES); |
184 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
185 | res = 1; |
186 | } else { |
187 | struct rt6_info *rt = (struct rt6_info *)dst; |
188 | int tmo = net->ipv6.sysctl.icmpv6_time; |
189 | |
190 | /* Give more bandwidth to wider prefixes. */ |
191 | if (rt->rt6i_dst.plen < 128) |
192 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); |
193 | |
194 | res = xrlim_allow(dst, tmo); |
195 | } |
196 | dst_release(dst); |
197 | return res; |
198 | } |
199 | |
200 | /* |
201 | * an inline helper for the "simple" if statement below |
202 | * checks if parameter problem report is caused by an |
203 | * unrecognized IPv6 option that has the Option Type |
204 | * highest-order two bits set to 10 |
205 | */ |
206 | |
207 | static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) |
208 | { |
209 | u8 _optval, *op; |
210 | |
211 | offset += skb_network_offset(skb); |
212 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
213 | if (op == NULL) |
214 | return 1; |
215 | return (*op & 0xC0) == 0x80; |
216 | } |
217 | |
218 | static int icmpv6_push_pending_frames(struct sock *sk, struct flowi *fl, struct icmp6hdr *thdr, int len) |
219 | { |
220 | struct sk_buff *skb; |
221 | struct icmp6hdr *icmp6h; |
222 | int err = 0; |
223 | |
224 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) |
225 | goto out; |
226 | |
227 | icmp6h = icmp6_hdr(skb); |
228 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
229 | icmp6h->icmp6_cksum = 0; |
230 | |
231 | if (skb_queue_len(&sk->sk_write_queue) == 1) { |
232 | skb->csum = csum_partial(icmp6h, |
233 | sizeof(struct icmp6hdr), skb->csum); |
234 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, |
235 | &fl->fl6_dst, |
236 | len, fl->proto, |
237 | skb->csum); |
238 | } else { |
239 | __wsum tmp_csum = 0; |
240 | |
241 | skb_queue_walk(&sk->sk_write_queue, skb) { |
242 | tmp_csum = csum_add(tmp_csum, skb->csum); |
243 | } |
244 | |
245 | tmp_csum = csum_partial(icmp6h, |
246 | sizeof(struct icmp6hdr), tmp_csum); |
247 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, |
248 | &fl->fl6_dst, |
249 | len, fl->proto, |
250 | tmp_csum); |
251 | } |
252 | ip6_push_pending_frames(sk); |
253 | out: |
254 | return err; |
255 | } |
256 | |
257 | struct icmpv6_msg { |
258 | struct sk_buff *skb; |
259 | int offset; |
260 | uint8_t type; |
261 | }; |
262 | |
263 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) |
264 | { |
265 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; |
266 | struct sk_buff *org_skb = msg->skb; |
267 | __wsum csum = 0; |
268 | |
269 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, |
270 | to, len, csum); |
271 | skb->csum = csum_block_add(skb->csum, csum, odd); |
272 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
273 | nf_ct_attach(skb, org_skb); |
274 | return 0; |
275 | } |
276 | |
277 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
278 | static void mip6_addr_swap(struct sk_buff *skb) |
279 | { |
280 | struct ipv6hdr *iph = ipv6_hdr(skb); |
281 | struct inet6_skb_parm *opt = IP6CB(skb); |
282 | struct ipv6_destopt_hao *hao; |
283 | struct in6_addr tmp; |
284 | int off; |
285 | |
286 | if (opt->dsthao) { |
287 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); |
288 | if (likely(off >= 0)) { |
289 | hao = (struct ipv6_destopt_hao *) |
290 | (skb_network_header(skb) + off); |
291 | ipv6_addr_copy(&tmp, &iph->saddr); |
292 | ipv6_addr_copy(&iph->saddr, &hao->addr); |
293 | ipv6_addr_copy(&hao->addr, &tmp); |
294 | } |
295 | } |
296 | } |
297 | #else |
298 | static inline void mip6_addr_swap(struct sk_buff *skb) {} |
299 | #endif |
300 | |
301 | /* |
302 | * Send an ICMP message in response to a packet in error |
303 | */ |
304 | void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) |
305 | { |
306 | struct net *net = dev_net(skb->dev); |
307 | struct inet6_dev *idev = NULL; |
308 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
309 | struct sock *sk; |
310 | struct ipv6_pinfo *np; |
311 | struct in6_addr *saddr = NULL; |
312 | struct dst_entry *dst; |
313 | struct dst_entry *dst2; |
314 | struct icmp6hdr tmp_hdr; |
315 | struct flowi fl; |
316 | struct flowi fl2; |
317 | struct icmpv6_msg msg; |
318 | int iif = 0; |
319 | int addr_type = 0; |
320 | int len; |
321 | int hlimit; |
322 | int err = 0; |
323 | |
324 | if ((u8 *)hdr < skb->head || |
325 | (skb->network_header + sizeof(*hdr)) > skb->tail) |
326 | return; |
327 | |
328 | /* |
329 | * Make sure we respect the rules |
330 | * i.e. RFC 1885 2.4(e) |
331 | * Rule (e.1) is enforced by not using icmpv6_send |
332 | * in any code that processes icmp errors. |
333 | */ |
334 | addr_type = ipv6_addr_type(&hdr->daddr); |
335 | |
336 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0)) |
337 | saddr = &hdr->daddr; |
338 | |
339 | /* |
340 | * Dest addr check |
341 | */ |
342 | |
343 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { |
344 | if (type != ICMPV6_PKT_TOOBIG && |
345 | !(type == ICMPV6_PARAMPROB && |
346 | code == ICMPV6_UNK_OPTION && |
347 | (opt_unrec(skb, info)))) |
348 | return; |
349 | |
350 | saddr = NULL; |
351 | } |
352 | |
353 | addr_type = ipv6_addr_type(&hdr->saddr); |
354 | |
355 | /* |
356 | * Source addr check |
357 | */ |
358 | |
359 | if (addr_type & IPV6_ADDR_LINKLOCAL) |
360 | iif = skb->dev->ifindex; |
361 | |
362 | /* |
363 | * Must not send error if the source does not uniquely |
364 | * identify a single node (RFC2463 Section 2.4). |
365 | * We check unspecified / multicast addresses here, |
366 | * and anycast addresses will be checked later. |
367 | */ |
368 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { |
369 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); |
370 | return; |
371 | } |
372 | |
373 | /* |
374 | * Never answer to a ICMP packet. |
375 | */ |
376 | if (is_ineligible(skb)) { |
377 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); |
378 | return; |
379 | } |
380 | |
381 | mip6_addr_swap(skb); |
382 | |
383 | memset(&fl, 0, sizeof(fl)); |
384 | fl.proto = IPPROTO_ICMPV6; |
385 | ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr); |
386 | if (saddr) |
387 | ipv6_addr_copy(&fl.fl6_src, saddr); |
388 | fl.oif = iif; |
389 | fl.fl_icmp_type = type; |
390 | fl.fl_icmp_code = code; |
391 | security_skb_classify_flow(skb, &fl); |
392 | |
393 | sk = icmpv6_xmit_lock(net); |
394 | if (sk == NULL) |
395 | return; |
396 | np = inet6_sk(sk); |
397 | |
398 | if (!icmpv6_xrlim_allow(sk, type, &fl)) |
399 | goto out; |
400 | |
401 | tmp_hdr.icmp6_type = type; |
402 | tmp_hdr.icmp6_code = code; |
403 | tmp_hdr.icmp6_cksum = 0; |
404 | tmp_hdr.icmp6_pointer = htonl(info); |
405 | |
406 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
407 | fl.oif = np->mcast_oif; |
408 | |
409 | err = ip6_dst_lookup(sk, &dst, &fl); |
410 | if (err) |
411 | goto out; |
412 | |
413 | /* |
414 | * We won't send icmp if the destination is known |
415 | * anycast. |
416 | */ |
417 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { |
418 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); |
419 | goto out_dst_release; |
420 | } |
421 | |
422 | /* No need to clone since we're just using its address. */ |
423 | dst2 = dst; |
424 | |
425 | err = xfrm_lookup(net, &dst, &fl, sk, 0); |
426 | switch (err) { |
427 | case 0: |
428 | if (dst != dst2) |
429 | goto route_done; |
430 | break; |
431 | case -EPERM: |
432 | dst = NULL; |
433 | break; |
434 | default: |
435 | goto out; |
436 | } |
437 | |
438 | if (xfrm_decode_session_reverse(skb, &fl2, AF_INET6)) |
439 | goto relookup_failed; |
440 | |
441 | if (ip6_dst_lookup(sk, &dst2, &fl2)) |
442 | goto relookup_failed; |
443 | |
444 | err = xfrm_lookup(net, &dst2, &fl2, sk, XFRM_LOOKUP_ICMP); |
445 | switch (err) { |
446 | case 0: |
447 | dst_release(dst); |
448 | dst = dst2; |
449 | break; |
450 | case -EPERM: |
451 | goto out_dst_release; |
452 | default: |
453 | relookup_failed: |
454 | if (!dst) |
455 | goto out; |
456 | break; |
457 | } |
458 | |
459 | route_done: |
460 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) |
461 | hlimit = np->mcast_hops; |
462 | else |
463 | hlimit = np->hop_limit; |
464 | if (hlimit < 0) |
465 | hlimit = ip6_dst_hoplimit(dst); |
466 | |
467 | msg.skb = skb; |
468 | msg.offset = skb_network_offset(skb); |
469 | msg.type = type; |
470 | |
471 | len = skb->len - msg.offset; |
472 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); |
473 | if (len < 0) { |
474 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
475 | goto out_dst_release; |
476 | } |
477 | |
478 | idev = in6_dev_get(skb->dev); |
479 | |
480 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, |
481 | len + sizeof(struct icmp6hdr), |
482 | sizeof(struct icmp6hdr), hlimit, |
483 | np->tclass, NULL, &fl, (struct rt6_info*)dst, |
484 | MSG_DONTWAIT); |
485 | if (err) { |
486 | ip6_flush_pending_frames(sk); |
487 | goto out_put; |
488 | } |
489 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); |
490 | |
491 | out_put: |
492 | if (likely(idev != NULL)) |
493 | in6_dev_put(idev); |
494 | out_dst_release: |
495 | dst_release(dst); |
496 | out: |
497 | icmpv6_xmit_unlock(sk); |
498 | } |
499 | |
500 | EXPORT_SYMBOL(icmpv6_send); |
501 | |
502 | static void icmpv6_echo_reply(struct sk_buff *skb) |
503 | { |
504 | struct net *net = dev_net(skb->dev); |
505 | struct sock *sk; |
506 | struct inet6_dev *idev; |
507 | struct ipv6_pinfo *np; |
508 | struct in6_addr *saddr = NULL; |
509 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
510 | struct icmp6hdr tmp_hdr; |
511 | struct flowi fl; |
512 | struct icmpv6_msg msg; |
513 | struct dst_entry *dst; |
514 | int err = 0; |
515 | int hlimit; |
516 | |
517 | saddr = &ipv6_hdr(skb)->daddr; |
518 | |
519 | if (!ipv6_unicast_destination(skb)) |
520 | saddr = NULL; |
521 | |
522 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); |
523 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; |
524 | |
525 | memset(&fl, 0, sizeof(fl)); |
526 | fl.proto = IPPROTO_ICMPV6; |
527 | ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr); |
528 | if (saddr) |
529 | ipv6_addr_copy(&fl.fl6_src, saddr); |
530 | fl.oif = skb->dev->ifindex; |
531 | fl.fl_icmp_type = ICMPV6_ECHO_REPLY; |
532 | security_skb_classify_flow(skb, &fl); |
533 | |
534 | sk = icmpv6_xmit_lock(net); |
535 | if (sk == NULL) |
536 | return; |
537 | np = inet6_sk(sk); |
538 | |
539 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
540 | fl.oif = np->mcast_oif; |
541 | |
542 | err = ip6_dst_lookup(sk, &dst, &fl); |
543 | if (err) |
544 | goto out; |
545 | if ((err = xfrm_lookup(net, &dst, &fl, sk, 0)) < 0) |
546 | goto out; |
547 | |
548 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) |
549 | hlimit = np->mcast_hops; |
550 | else |
551 | hlimit = np->hop_limit; |
552 | if (hlimit < 0) |
553 | hlimit = ip6_dst_hoplimit(dst); |
554 | |
555 | idev = in6_dev_get(skb->dev); |
556 | |
557 | msg.skb = skb; |
558 | msg.offset = 0; |
559 | msg.type = ICMPV6_ECHO_REPLY; |
560 | |
561 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), |
562 | sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl, |
563 | (struct rt6_info*)dst, MSG_DONTWAIT); |
564 | |
565 | if (err) { |
566 | ip6_flush_pending_frames(sk); |
567 | goto out_put; |
568 | } |
569 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); |
570 | |
571 | out_put: |
572 | if (likely(idev != NULL)) |
573 | in6_dev_put(idev); |
574 | dst_release(dst); |
575 | out: |
576 | icmpv6_xmit_unlock(sk); |
577 | } |
578 | |
579 | static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) |
580 | { |
581 | const struct inet6_protocol *ipprot; |
582 | int inner_offset; |
583 | int hash; |
584 | u8 nexthdr; |
585 | |
586 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
587 | return; |
588 | |
589 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; |
590 | if (ipv6_ext_hdr(nexthdr)) { |
591 | /* now skip over extension headers */ |
592 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); |
593 | if (inner_offset<0) |
594 | return; |
595 | } else { |
596 | inner_offset = sizeof(struct ipv6hdr); |
597 | } |
598 | |
599 | /* Checkin header including 8 bytes of inner protocol header. */ |
600 | if (!pskb_may_pull(skb, inner_offset+8)) |
601 | return; |
602 | |
603 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
604 | Without this we will not able f.e. to make source routed |
605 | pmtu discovery. |
606 | Corresponding argument (opt) to notifiers is already added. |
607 | --ANK (980726) |
608 | */ |
609 | |
610 | hash = nexthdr & (MAX_INET_PROTOS - 1); |
611 | |
612 | rcu_read_lock(); |
613 | ipprot = rcu_dereference(inet6_protos[hash]); |
614 | if (ipprot && ipprot->err_handler) |
615 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); |
616 | rcu_read_unlock(); |
617 | |
618 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
619 | } |
620 | |
621 | /* |
622 | * Handle icmp messages |
623 | */ |
624 | |
625 | static int icmpv6_rcv(struct sk_buff *skb) |
626 | { |
627 | struct net_device *dev = skb->dev; |
628 | struct inet6_dev *idev = __in6_dev_get(dev); |
629 | struct in6_addr *saddr, *daddr; |
630 | struct ipv6hdr *orig_hdr; |
631 | struct icmp6hdr *hdr; |
632 | u8 type; |
633 | |
634 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
635 | struct sec_path *sp = skb_sec_path(skb); |
636 | int nh; |
637 | |
638 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
639 | XFRM_STATE_ICMP)) |
640 | goto drop_no_count; |
641 | |
642 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) |
643 | goto drop_no_count; |
644 | |
645 | nh = skb_network_offset(skb); |
646 | skb_set_network_header(skb, sizeof(*hdr)); |
647 | |
648 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) |
649 | goto drop_no_count; |
650 | |
651 | skb_set_network_header(skb, nh); |
652 | } |
653 | |
654 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); |
655 | |
656 | saddr = &ipv6_hdr(skb)->saddr; |
657 | daddr = &ipv6_hdr(skb)->daddr; |
658 | |
659 | /* Perform checksum. */ |
660 | switch (skb->ip_summed) { |
661 | case CHECKSUM_COMPLETE: |
662 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
663 | skb->csum)) |
664 | break; |
665 | /* fall through */ |
666 | case CHECKSUM_NONE: |
667 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
668 | IPPROTO_ICMPV6, 0)); |
669 | if (__skb_checksum_complete(skb)) { |
670 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n", |
671 | saddr, daddr); |
672 | goto discard_it; |
673 | } |
674 | } |
675 | |
676 | if (!pskb_pull(skb, sizeof(*hdr))) |
677 | goto discard_it; |
678 | |
679 | hdr = icmp6_hdr(skb); |
680 | |
681 | type = hdr->icmp6_type; |
682 | |
683 | ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); |
684 | |
685 | switch (type) { |
686 | case ICMPV6_ECHO_REQUEST: |
687 | icmpv6_echo_reply(skb); |
688 | break; |
689 | |
690 | case ICMPV6_ECHO_REPLY: |
691 | /* we couldn't care less */ |
692 | break; |
693 | |
694 | case ICMPV6_PKT_TOOBIG: |
695 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update |
696 | standard destination cache. Seems, only "advanced" |
697 | destination cache will allow to solve this problem |
698 | --ANK (980726) |
699 | */ |
700 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
701 | goto discard_it; |
702 | hdr = icmp6_hdr(skb); |
703 | orig_hdr = (struct ipv6hdr *) (hdr + 1); |
704 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, |
705 | ntohl(hdr->icmp6_mtu)); |
706 | |
707 | /* |
708 | * Drop through to notify |
709 | */ |
710 | |
711 | case ICMPV6_DEST_UNREACH: |
712 | case ICMPV6_TIME_EXCEED: |
713 | case ICMPV6_PARAMPROB: |
714 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); |
715 | break; |
716 | |
717 | case NDISC_ROUTER_SOLICITATION: |
718 | case NDISC_ROUTER_ADVERTISEMENT: |
719 | case NDISC_NEIGHBOUR_SOLICITATION: |
720 | case NDISC_NEIGHBOUR_ADVERTISEMENT: |
721 | case NDISC_REDIRECT: |
722 | ndisc_rcv(skb); |
723 | break; |
724 | |
725 | case ICMPV6_MGM_QUERY: |
726 | igmp6_event_query(skb); |
727 | break; |
728 | |
729 | case ICMPV6_MGM_REPORT: |
730 | igmp6_event_report(skb); |
731 | break; |
732 | |
733 | case ICMPV6_MGM_REDUCTION: |
734 | case ICMPV6_NI_QUERY: |
735 | case ICMPV6_NI_REPLY: |
736 | case ICMPV6_MLD2_REPORT: |
737 | case ICMPV6_DHAAD_REQUEST: |
738 | case ICMPV6_DHAAD_REPLY: |
739 | case ICMPV6_MOBILE_PREFIX_SOL: |
740 | case ICMPV6_MOBILE_PREFIX_ADV: |
741 | break; |
742 | |
743 | default: |
744 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
745 | |
746 | /* informational */ |
747 | if (type & ICMPV6_INFOMSG_MASK) |
748 | break; |
749 | |
750 | /* |
751 | * error of unknown type. |
752 | * must pass to upper level |
753 | */ |
754 | |
755 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); |
756 | } |
757 | |
758 | kfree_skb(skb); |
759 | return 0; |
760 | |
761 | discard_it: |
762 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); |
763 | drop_no_count: |
764 | kfree_skb(skb); |
765 | return 0; |
766 | } |
767 | |
768 | void icmpv6_flow_init(struct sock *sk, struct flowi *fl, |
769 | u8 type, |
770 | const struct in6_addr *saddr, |
771 | const struct in6_addr *daddr, |
772 | int oif) |
773 | { |
774 | memset(fl, 0, sizeof(*fl)); |
775 | ipv6_addr_copy(&fl->fl6_src, saddr); |
776 | ipv6_addr_copy(&fl->fl6_dst, daddr); |
777 | fl->proto = IPPROTO_ICMPV6; |
778 | fl->fl_icmp_type = type; |
779 | fl->fl_icmp_code = 0; |
780 | fl->oif = oif; |
781 | security_sk_classify_flow(sk, fl); |
782 | } |
783 | |
784 | /* |
785 | * Special lock-class for __icmpv6_sk: |
786 | */ |
787 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; |
788 | |
789 | static int __net_init icmpv6_sk_init(struct net *net) |
790 | { |
791 | struct sock *sk; |
792 | int err, i, j; |
793 | |
794 | net->ipv6.icmp_sk = |
795 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); |
796 | if (net->ipv6.icmp_sk == NULL) |
797 | return -ENOMEM; |
798 | |
799 | for_each_possible_cpu(i) { |
800 | err = inet_ctl_sock_create(&sk, PF_INET6, |
801 | SOCK_RAW, IPPROTO_ICMPV6, net); |
802 | if (err < 0) { |
803 | printk(KERN_ERR |
804 | "Failed to initialize the ICMP6 control socket " |
805 | "(err %d).\n", |
806 | err); |
807 | goto fail; |
808 | } |
809 | |
810 | net->ipv6.icmp_sk[i] = sk; |
811 | |
812 | /* |
813 | * Split off their lock-class, because sk->sk_dst_lock |
814 | * gets used from softirqs, which is safe for |
815 | * __icmpv6_sk (because those never get directly used |
816 | * via userspace syscalls), but unsafe for normal sockets. |
817 | */ |
818 | lockdep_set_class(&sk->sk_dst_lock, |
819 | &icmpv6_socket_sk_dst_lock_key); |
820 | |
821 | /* Enough space for 2 64K ICMP packets, including |
822 | * sk_buff struct overhead. |
823 | */ |
824 | sk->sk_sndbuf = |
825 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); |
826 | } |
827 | return 0; |
828 | |
829 | fail: |
830 | for (j = 0; j < i; j++) |
831 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); |
832 | kfree(net->ipv6.icmp_sk); |
833 | return err; |
834 | } |
835 | |
836 | static void __net_exit icmpv6_sk_exit(struct net *net) |
837 | { |
838 | int i; |
839 | |
840 | for_each_possible_cpu(i) { |
841 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); |
842 | } |
843 | kfree(net->ipv6.icmp_sk); |
844 | } |
845 | |
846 | static struct pernet_operations icmpv6_sk_ops = { |
847 | .init = icmpv6_sk_init, |
848 | .exit = icmpv6_sk_exit, |
849 | }; |
850 | |
851 | int __init icmpv6_init(void) |
852 | { |
853 | int err; |
854 | |
855 | err = register_pernet_subsys(&icmpv6_sk_ops); |
856 | if (err < 0) |
857 | return err; |
858 | |
859 | err = -EAGAIN; |
860 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) |
861 | goto fail; |
862 | return 0; |
863 | |
864 | fail: |
865 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); |
866 | unregister_pernet_subsys(&icmpv6_sk_ops); |
867 | return err; |
868 | } |
869 | |
870 | void icmpv6_cleanup(void) |
871 | { |
872 | unregister_pernet_subsys(&icmpv6_sk_ops); |
873 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
874 | } |
875 | |
876 | |
877 | static const struct icmp6_err { |
878 | int err; |
879 | int fatal; |
880 | } tab_unreach[] = { |
881 | { /* NOROUTE */ |
882 | .err = ENETUNREACH, |
883 | .fatal = 0, |
884 | }, |
885 | { /* ADM_PROHIBITED */ |
886 | .err = EACCES, |
887 | .fatal = 1, |
888 | }, |
889 | { /* Was NOT_NEIGHBOUR, now reserved */ |
890 | .err = EHOSTUNREACH, |
891 | .fatal = 0, |
892 | }, |
893 | { /* ADDR_UNREACH */ |
894 | .err = EHOSTUNREACH, |
895 | .fatal = 0, |
896 | }, |
897 | { /* PORT_UNREACH */ |
898 | .err = ECONNREFUSED, |
899 | .fatal = 1, |
900 | }, |
901 | }; |
902 | |
903 | int icmpv6_err_convert(u8 type, u8 code, int *err) |
904 | { |
905 | int fatal = 0; |
906 | |
907 | *err = EPROTO; |
908 | |
909 | switch (type) { |
910 | case ICMPV6_DEST_UNREACH: |
911 | fatal = 1; |
912 | if (code <= ICMPV6_PORT_UNREACH) { |
913 | *err = tab_unreach[code].err; |
914 | fatal = tab_unreach[code].fatal; |
915 | } |
916 | break; |
917 | |
918 | case ICMPV6_PKT_TOOBIG: |
919 | *err = EMSGSIZE; |
920 | break; |
921 | |
922 | case ICMPV6_PARAMPROB: |
923 | *err = EPROTO; |
924 | fatal = 1; |
925 | break; |
926 | |
927 | case ICMPV6_TIME_EXCEED: |
928 | *err = EHOSTUNREACH; |
929 | break; |
930 | } |
931 | |
932 | return fatal; |
933 | } |
934 | |
935 | EXPORT_SYMBOL(icmpv6_err_convert); |
936 | |
937 | #ifdef CONFIG_SYSCTL |
938 | ctl_table ipv6_icmp_table_template[] = { |
939 | { |
940 | .procname = "ratelimit", |
941 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
942 | .maxlen = sizeof(int), |
943 | .mode = 0644, |
944 | .proc_handler = proc_dointvec_ms_jiffies, |
945 | }, |
946 | { }, |
947 | }; |
948 | |
949 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
950 | { |
951 | struct ctl_table *table; |
952 | |
953 | table = kmemdup(ipv6_icmp_table_template, |
954 | sizeof(ipv6_icmp_table_template), |
955 | GFP_KERNEL); |
956 | |
957 | if (table) |
958 | table[0].data = &net->ipv6.sysctl.icmpv6_time; |
959 | |
960 | return table; |
961 | } |
962 | #endif |
963 | |
964 |
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