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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 | #include <net/dsfield.h> | |
71 | #include <net/l3mdev.h> | |
72 | ||
73 | #include <asm/uaccess.h> | |
74 | ||
75 | /* | |
76 | * The ICMP socket(s). This is the most convenient way to flow control | |
77 | * our ICMP output as well as maintain a clean interface throughout | |
78 | * all layers. All Socketless IP sends will soon be gone. | |
79 | * | |
80 | * On SMP we have one ICMP socket per-cpu. | |
81 | */ | |
82 | static inline struct sock *icmpv6_sk(struct net *net) | |
83 | { | |
84 | return net->ipv6.icmp_sk[smp_processor_id()]; | |
85 | } | |
86 | ||
87 | static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, | |
88 | u8 type, u8 code, int offset, __be32 info) | |
89 | { | |
90 | /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */ | |
91 | struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset); | |
92 | struct net *net = dev_net(skb->dev); | |
93 | ||
94 | if (type == ICMPV6_PKT_TOOBIG) | |
95 | ip6_update_pmtu(skb, net, info, 0, 0); | |
96 | else if (type == NDISC_REDIRECT) | |
97 | ip6_redirect(skb, net, skb->dev->ifindex, 0); | |
98 | ||
99 | if (!(type & ICMPV6_INFOMSG_MASK)) | |
100 | if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST) | |
101 | ping_err(skb, offset, info); | |
102 | } | |
103 | ||
104 | static int icmpv6_rcv(struct sk_buff *skb); | |
105 | ||
106 | static const struct inet6_protocol icmpv6_protocol = { | |
107 | .handler = icmpv6_rcv, | |
108 | .err_handler = icmpv6_err, | |
109 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, | |
110 | }; | |
111 | ||
112 | static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) | |
113 | { | |
114 | struct sock *sk; | |
115 | ||
116 | local_bh_disable(); | |
117 | ||
118 | sk = icmpv6_sk(net); | |
119 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { | |
120 | /* This can happen if the output path (f.e. SIT or | |
121 | * ip6ip6 tunnel) signals dst_link_failure() for an | |
122 | * outgoing ICMP6 packet. | |
123 | */ | |
124 | local_bh_enable(); | |
125 | return NULL; | |
126 | } | |
127 | return sk; | |
128 | } | |
129 | ||
130 | static __inline__ void icmpv6_xmit_unlock(struct sock *sk) | |
131 | { | |
132 | spin_unlock_bh(&sk->sk_lock.slock); | |
133 | } | |
134 | ||
135 | /* | |
136 | * Figure out, may we reply to this packet with icmp error. | |
137 | * | |
138 | * We do not reply, if: | |
139 | * - it was icmp error message. | |
140 | * - it is truncated, so that it is known, that protocol is ICMPV6 | |
141 | * (i.e. in the middle of some exthdr) | |
142 | * | |
143 | * --ANK (980726) | |
144 | */ | |
145 | ||
146 | static bool is_ineligible(const struct sk_buff *skb) | |
147 | { | |
148 | int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; | |
149 | int len = skb->len - ptr; | |
150 | __u8 nexthdr = ipv6_hdr(skb)->nexthdr; | |
151 | __be16 frag_off; | |
152 | ||
153 | if (len < 0) | |
154 | return true; | |
155 | ||
156 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); | |
157 | if (ptr < 0) | |
158 | return false; | |
159 | if (nexthdr == IPPROTO_ICMPV6) { | |
160 | u8 _type, *tp; | |
161 | tp = skb_header_pointer(skb, | |
162 | ptr+offsetof(struct icmp6hdr, icmp6_type), | |
163 | sizeof(_type), &_type); | |
164 | if (!tp || !(*tp & ICMPV6_INFOMSG_MASK)) | |
165 | return true; | |
166 | } | |
167 | return false; | |
168 | } | |
169 | ||
170 | /* | |
171 | * Check the ICMP output rate limit | |
172 | */ | |
173 | static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, | |
174 | struct flowi6 *fl6) | |
175 | { | |
176 | struct net *net = sock_net(sk); | |
177 | struct dst_entry *dst; | |
178 | bool res = false; | |
179 | ||
180 | /* Informational messages are not limited. */ | |
181 | if (type & ICMPV6_INFOMSG_MASK) | |
182 | return true; | |
183 | ||
184 | /* Do not limit pmtu discovery, it would break it. */ | |
185 | if (type == ICMPV6_PKT_TOOBIG) | |
186 | return true; | |
187 | ||
188 | /* | |
189 | * Look up the output route. | |
190 | * XXX: perhaps the expire for routing entries cloned by | |
191 | * this lookup should be more aggressive (not longer than timeout). | |
192 | */ | |
193 | dst = ip6_route_output(net, sk, fl6); | |
194 | if (dst->error) { | |
195 | IP6_INC_STATS(net, ip6_dst_idev(dst), | |
196 | IPSTATS_MIB_OUTNOROUTES); | |
197 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { | |
198 | res = true; | |
199 | } else { | |
200 | struct rt6_info *rt = (struct rt6_info *)dst; | |
201 | int tmo = net->ipv6.sysctl.icmpv6_time; | |
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 | if (icmp_global_allow()) { | |
208 | struct inet_peer *peer; | |
209 | ||
210 | peer = inet_getpeer_v6(net->ipv6.peers, | |
211 | &fl6->daddr, 1); | |
212 | res = inet_peer_xrlim_allow(peer, tmo); | |
213 | if (peer) | |
214 | inet_putpeer(peer); | |
215 | } | |
216 | } | |
217 | dst_release(dst); | |
218 | return res; | |
219 | } | |
220 | ||
221 | /* | |
222 | * an inline helper for the "simple" if statement below | |
223 | * checks if parameter problem report is caused by an | |
224 | * unrecognized IPv6 option that has the Option Type | |
225 | * highest-order two bits set to 10 | |
226 | */ | |
227 | ||
228 | static bool opt_unrec(struct sk_buff *skb, __u32 offset) | |
229 | { | |
230 | u8 _optval, *op; | |
231 | ||
232 | offset += skb_network_offset(skb); | |
233 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); | |
234 | if (!op) | |
235 | return true; | |
236 | return (*op & 0xC0) == 0x80; | |
237 | } | |
238 | ||
239 | int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, | |
240 | struct icmp6hdr *thdr, int len) | |
241 | { | |
242 | struct sk_buff *skb; | |
243 | struct icmp6hdr *icmp6h; | |
244 | int err = 0; | |
245 | ||
246 | skb = skb_peek(&sk->sk_write_queue); | |
247 | if (!skb) | |
248 | goto out; | |
249 | ||
250 | icmp6h = icmp6_hdr(skb); | |
251 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); | |
252 | icmp6h->icmp6_cksum = 0; | |
253 | ||
254 | if (skb_queue_len(&sk->sk_write_queue) == 1) { | |
255 | skb->csum = csum_partial(icmp6h, | |
256 | sizeof(struct icmp6hdr), skb->csum); | |
257 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, | |
258 | &fl6->daddr, | |
259 | len, fl6->flowi6_proto, | |
260 | skb->csum); | |
261 | } else { | |
262 | __wsum tmp_csum = 0; | |
263 | ||
264 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
265 | tmp_csum = csum_add(tmp_csum, skb->csum); | |
266 | } | |
267 | ||
268 | tmp_csum = csum_partial(icmp6h, | |
269 | sizeof(struct icmp6hdr), tmp_csum); | |
270 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, | |
271 | &fl6->daddr, | |
272 | len, fl6->flowi6_proto, | |
273 | tmp_csum); | |
274 | } | |
275 | ip6_push_pending_frames(sk); | |
276 | out: | |
277 | return err; | |
278 | } | |
279 | ||
280 | struct icmpv6_msg { | |
281 | struct sk_buff *skb; | |
282 | int offset; | |
283 | uint8_t type; | |
284 | }; | |
285 | ||
286 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
287 | { | |
288 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; | |
289 | struct sk_buff *org_skb = msg->skb; | |
290 | __wsum csum = 0; | |
291 | ||
292 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, | |
293 | to, len, csum); | |
294 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
295 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) | |
296 | nf_ct_attach(skb, org_skb); | |
297 | return 0; | |
298 | } | |
299 | ||
300 | #if IS_ENABLED(CONFIG_IPV6_MIP6) | |
301 | static void mip6_addr_swap(struct sk_buff *skb) | |
302 | { | |
303 | struct ipv6hdr *iph = ipv6_hdr(skb); | |
304 | struct inet6_skb_parm *opt = IP6CB(skb); | |
305 | struct ipv6_destopt_hao *hao; | |
306 | struct in6_addr tmp; | |
307 | int off; | |
308 | ||
309 | if (opt->dsthao) { | |
310 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); | |
311 | if (likely(off >= 0)) { | |
312 | hao = (struct ipv6_destopt_hao *) | |
313 | (skb_network_header(skb) + off); | |
314 | tmp = iph->saddr; | |
315 | iph->saddr = hao->addr; | |
316 | hao->addr = tmp; | |
317 | } | |
318 | } | |
319 | } | |
320 | #else | |
321 | static inline void mip6_addr_swap(struct sk_buff *skb) {} | |
322 | #endif | |
323 | ||
324 | static struct dst_entry *icmpv6_route_lookup(struct net *net, | |
325 | struct sk_buff *skb, | |
326 | struct sock *sk, | |
327 | struct flowi6 *fl6) | |
328 | { | |
329 | struct dst_entry *dst, *dst2; | |
330 | struct flowi6 fl2; | |
331 | int err; | |
332 | ||
333 | err = ip6_dst_lookup(net, sk, &dst, fl6); | |
334 | if (err) | |
335 | return ERR_PTR(err); | |
336 | ||
337 | /* | |
338 | * We won't send icmp if the destination is known | |
339 | * anycast. | |
340 | */ | |
341 | if (ipv6_anycast_destination(dst, &fl6->daddr)) { | |
342 | net_dbg_ratelimited("icmp6_send: acast source\n"); | |
343 | dst_release(dst); | |
344 | return ERR_PTR(-EINVAL); | |
345 | } | |
346 | ||
347 | /* No need to clone since we're just using its address. */ | |
348 | dst2 = dst; | |
349 | ||
350 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); | |
351 | if (!IS_ERR(dst)) { | |
352 | if (dst != dst2) | |
353 | return dst; | |
354 | } else { | |
355 | if (PTR_ERR(dst) == -EPERM) | |
356 | dst = NULL; | |
357 | else | |
358 | return dst; | |
359 | } | |
360 | ||
361 | err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6); | |
362 | if (err) | |
363 | goto relookup_failed; | |
364 | ||
365 | err = ip6_dst_lookup(net, sk, &dst2, &fl2); | |
366 | if (err) | |
367 | goto relookup_failed; | |
368 | ||
369 | dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); | |
370 | if (!IS_ERR(dst2)) { | |
371 | dst_release(dst); | |
372 | dst = dst2; | |
373 | } else { | |
374 | err = PTR_ERR(dst2); | |
375 | if (err == -EPERM) { | |
376 | dst_release(dst); | |
377 | return dst2; | |
378 | } else | |
379 | goto relookup_failed; | |
380 | } | |
381 | ||
382 | relookup_failed: | |
383 | if (dst) | |
384 | return dst; | |
385 | return ERR_PTR(err); | |
386 | } | |
387 | ||
388 | /* | |
389 | * Send an ICMP message in response to a packet in error | |
390 | */ | |
391 | static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, | |
392 | const struct in6_addr *force_saddr) | |
393 | { | |
394 | struct net *net = dev_net(skb->dev); | |
395 | struct inet6_dev *idev = NULL; | |
396 | struct ipv6hdr *hdr = ipv6_hdr(skb); | |
397 | struct sock *sk; | |
398 | struct ipv6_pinfo *np; | |
399 | const struct in6_addr *saddr = NULL; | |
400 | struct dst_entry *dst; | |
401 | struct icmp6hdr tmp_hdr; | |
402 | struct flowi6 fl6; | |
403 | struct icmpv6_msg msg; | |
404 | struct sockcm_cookie sockc_unused = {0}; | |
405 | struct ipcm6_cookie ipc6; | |
406 | int iif = 0; | |
407 | int addr_type = 0; | |
408 | int len; | |
409 | int err = 0; | |
410 | u32 mark = IP6_REPLY_MARK(net, skb->mark); | |
411 | ||
412 | if ((u8 *)hdr < skb->head || | |
413 | (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb)) | |
414 | return; | |
415 | ||
416 | /* | |
417 | * Make sure we respect the rules | |
418 | * i.e. RFC 1885 2.4(e) | |
419 | * Rule (e.1) is enforced by not using icmp6_send | |
420 | * in any code that processes icmp errors. | |
421 | */ | |
422 | addr_type = ipv6_addr_type(&hdr->daddr); | |
423 | ||
424 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) || | |
425 | ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr)) | |
426 | saddr = &hdr->daddr; | |
427 | ||
428 | /* | |
429 | * Dest addr check | |
430 | */ | |
431 | ||
432 | if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) { | |
433 | if (type != ICMPV6_PKT_TOOBIG && | |
434 | !(type == ICMPV6_PARAMPROB && | |
435 | code == ICMPV6_UNK_OPTION && | |
436 | (opt_unrec(skb, info)))) | |
437 | return; | |
438 | ||
439 | saddr = NULL; | |
440 | } | |
441 | ||
442 | addr_type = ipv6_addr_type(&hdr->saddr); | |
443 | ||
444 | /* | |
445 | * Source addr check | |
446 | */ | |
447 | ||
448 | if (__ipv6_addr_needs_scope_id(addr_type)) | |
449 | iif = skb->dev->ifindex; | |
450 | else | |
451 | iif = l3mdev_master_ifindex(skb->dev); | |
452 | ||
453 | /* | |
454 | * Must not send error if the source does not uniquely | |
455 | * identify a single node (RFC2463 Section 2.4). | |
456 | * We check unspecified / multicast addresses here, | |
457 | * and anycast addresses will be checked later. | |
458 | */ | |
459 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { | |
460 | net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n", | |
461 | &hdr->saddr, &hdr->daddr); | |
462 | return; | |
463 | } | |
464 | ||
465 | /* | |
466 | * Never answer to a ICMP packet. | |
467 | */ | |
468 | if (is_ineligible(skb)) { | |
469 | net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n", | |
470 | &hdr->saddr, &hdr->daddr); | |
471 | return; | |
472 | } | |
473 | ||
474 | mip6_addr_swap(skb); | |
475 | ||
476 | memset(&fl6, 0, sizeof(fl6)); | |
477 | fl6.flowi6_proto = IPPROTO_ICMPV6; | |
478 | fl6.daddr = hdr->saddr; | |
479 | if (force_saddr) | |
480 | saddr = force_saddr; | |
481 | if (saddr) | |
482 | fl6.saddr = *saddr; | |
483 | fl6.flowi6_mark = mark; | |
484 | fl6.flowi6_oif = iif; | |
485 | fl6.fl6_icmp_type = type; | |
486 | fl6.fl6_icmp_code = code; | |
487 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); | |
488 | ||
489 | sk = icmpv6_xmit_lock(net); | |
490 | if (!sk) | |
491 | return; | |
492 | sk->sk_mark = mark; | |
493 | np = inet6_sk(sk); | |
494 | ||
495 | if (!icmpv6_xrlim_allow(sk, type, &fl6)) | |
496 | goto out; | |
497 | ||
498 | tmp_hdr.icmp6_type = type; | |
499 | tmp_hdr.icmp6_code = code; | |
500 | tmp_hdr.icmp6_cksum = 0; | |
501 | tmp_hdr.icmp6_pointer = htonl(info); | |
502 | ||
503 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
504 | fl6.flowi6_oif = np->mcast_oif; | |
505 | else if (!fl6.flowi6_oif) | |
506 | fl6.flowi6_oif = np->ucast_oif; | |
507 | ||
508 | ipc6.tclass = np->tclass; | |
509 | fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); | |
510 | ||
511 | dst = icmpv6_route_lookup(net, skb, sk, &fl6); | |
512 | if (IS_ERR(dst)) | |
513 | goto out; | |
514 | ||
515 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
516 | ipc6.dontfrag = np->dontfrag; | |
517 | ipc6.opt = NULL; | |
518 | ||
519 | msg.skb = skb; | |
520 | msg.offset = skb_network_offset(skb); | |
521 | msg.type = type; | |
522 | ||
523 | len = skb->len - msg.offset; | |
524 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr)); | |
525 | if (len < 0) { | |
526 | net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n", | |
527 | &hdr->saddr, &hdr->daddr); | |
528 | goto out_dst_release; | |
529 | } | |
530 | ||
531 | rcu_read_lock(); | |
532 | idev = __in6_dev_get(skb->dev); | |
533 | ||
534 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
535 | len + sizeof(struct icmp6hdr), | |
536 | sizeof(struct icmp6hdr), | |
537 | &ipc6, &fl6, (struct rt6_info *)dst, | |
538 | MSG_DONTWAIT, &sockc_unused); | |
539 | if (err) { | |
540 | ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); | |
541 | ip6_flush_pending_frames(sk); | |
542 | } else { | |
543 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, | |
544 | len + sizeof(struct icmp6hdr)); | |
545 | } | |
546 | rcu_read_unlock(); | |
547 | out_dst_release: | |
548 | dst_release(dst); | |
549 | out: | |
550 | icmpv6_xmit_unlock(sk); | |
551 | } | |
552 | ||
553 | /* Slightly more convenient version of icmp6_send. | |
554 | */ | |
555 | void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) | |
556 | { | |
557 | icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL); | |
558 | kfree_skb(skb); | |
559 | } | |
560 | ||
561 | static void icmpv6_echo_reply(struct sk_buff *skb) | |
562 | { | |
563 | struct net *net = dev_net(skb->dev); | |
564 | struct sock *sk; | |
565 | struct inet6_dev *idev; | |
566 | struct ipv6_pinfo *np; | |
567 | const struct in6_addr *saddr = NULL; | |
568 | struct icmp6hdr *icmph = icmp6_hdr(skb); | |
569 | struct icmp6hdr tmp_hdr; | |
570 | struct flowi6 fl6; | |
571 | struct icmpv6_msg msg; | |
572 | struct dst_entry *dst; | |
573 | struct ipcm6_cookie ipc6; | |
574 | int err = 0; | |
575 | u32 mark = IP6_REPLY_MARK(net, skb->mark); | |
576 | struct sockcm_cookie sockc_unused = {0}; | |
577 | ||
578 | saddr = &ipv6_hdr(skb)->daddr; | |
579 | ||
580 | if (!ipv6_unicast_destination(skb) && | |
581 | !(net->ipv6.sysctl.anycast_src_echo_reply && | |
582 | ipv6_anycast_destination(skb_dst(skb), saddr))) | |
583 | saddr = NULL; | |
584 | ||
585 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
586 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
587 | ||
588 | memset(&fl6, 0, sizeof(fl6)); | |
589 | fl6.flowi6_proto = IPPROTO_ICMPV6; | |
590 | fl6.daddr = ipv6_hdr(skb)->saddr; | |
591 | if (saddr) | |
592 | fl6.saddr = *saddr; | |
593 | fl6.flowi6_oif = skb->dev->ifindex; | |
594 | fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; | |
595 | fl6.flowi6_mark = mark; | |
596 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); | |
597 | ||
598 | sk = icmpv6_xmit_lock(net); | |
599 | if (!sk) | |
600 | return; | |
601 | sk->sk_mark = mark; | |
602 | np = inet6_sk(sk); | |
603 | ||
604 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) | |
605 | fl6.flowi6_oif = np->mcast_oif; | |
606 | else if (!fl6.flowi6_oif) | |
607 | fl6.flowi6_oif = np->ucast_oif; | |
608 | ||
609 | err = ip6_dst_lookup(net, sk, &dst, &fl6); | |
610 | if (err) | |
611 | goto out; | |
612 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); | |
613 | if (IS_ERR(dst)) | |
614 | goto out; | |
615 | ||
616 | idev = __in6_dev_get(skb->dev); | |
617 | ||
618 | msg.skb = skb; | |
619 | msg.offset = 0; | |
620 | msg.type = ICMPV6_ECHO_REPLY; | |
621 | ||
622 | ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); | |
623 | ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb)); | |
624 | ipc6.dontfrag = np->dontfrag; | |
625 | ipc6.opt = NULL; | |
626 | ||
627 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
628 | sizeof(struct icmp6hdr), &ipc6, &fl6, | |
629 | (struct rt6_info *)dst, MSG_DONTWAIT, | |
630 | &sockc_unused); | |
631 | ||
632 | if (err) { | |
633 | __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); | |
634 | ip6_flush_pending_frames(sk); | |
635 | } else { | |
636 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, | |
637 | skb->len + sizeof(struct icmp6hdr)); | |
638 | } | |
639 | dst_release(dst); | |
640 | out: | |
641 | icmpv6_xmit_unlock(sk); | |
642 | } | |
643 | ||
644 | void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) | |
645 | { | |
646 | const struct inet6_protocol *ipprot; | |
647 | int inner_offset; | |
648 | __be16 frag_off; | |
649 | u8 nexthdr; | |
650 | struct net *net = dev_net(skb->dev); | |
651 | ||
652 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
653 | goto out; | |
654 | ||
655 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
656 | if (ipv6_ext_hdr(nexthdr)) { | |
657 | /* now skip over extension headers */ | |
658 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), | |
659 | &nexthdr, &frag_off); | |
660 | if (inner_offset < 0) | |
661 | goto out; | |
662 | } else { | |
663 | inner_offset = sizeof(struct ipv6hdr); | |
664 | } | |
665 | ||
666 | /* Checkin header including 8 bytes of inner protocol header. */ | |
667 | if (!pskb_may_pull(skb, inner_offset+8)) | |
668 | goto out; | |
669 | ||
670 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. | |
671 | Without this we will not able f.e. to make source routed | |
672 | pmtu discovery. | |
673 | Corresponding argument (opt) to notifiers is already added. | |
674 | --ANK (980726) | |
675 | */ | |
676 | ||
677 | ipprot = rcu_dereference(inet6_protos[nexthdr]); | |
678 | if (ipprot && ipprot->err_handler) | |
679 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
680 | ||
681 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); | |
682 | return; | |
683 | ||
684 | out: | |
685 | __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); | |
686 | } | |
687 | ||
688 | /* | |
689 | * Handle icmp messages | |
690 | */ | |
691 | ||
692 | static int icmpv6_rcv(struct sk_buff *skb) | |
693 | { | |
694 | struct net_device *dev = skb->dev; | |
695 | struct inet6_dev *idev = __in6_dev_get(dev); | |
696 | const struct in6_addr *saddr, *daddr; | |
697 | struct icmp6hdr *hdr; | |
698 | u8 type; | |
699 | bool success = false; | |
700 | ||
701 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
702 | struct sec_path *sp = skb_sec_path(skb); | |
703 | int nh; | |
704 | ||
705 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & | |
706 | XFRM_STATE_ICMP)) | |
707 | goto drop_no_count; | |
708 | ||
709 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr))) | |
710 | goto drop_no_count; | |
711 | ||
712 | nh = skb_network_offset(skb); | |
713 | skb_set_network_header(skb, sizeof(*hdr)); | |
714 | ||
715 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
716 | goto drop_no_count; | |
717 | ||
718 | skb_set_network_header(skb, nh); | |
719 | } | |
720 | ||
721 | __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS); | |
722 | ||
723 | saddr = &ipv6_hdr(skb)->saddr; | |
724 | daddr = &ipv6_hdr(skb)->daddr; | |
725 | ||
726 | if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) { | |
727 | net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n", | |
728 | saddr, daddr); | |
729 | goto csum_error; | |
730 | } | |
731 | ||
732 | if (!pskb_pull(skb, sizeof(*hdr))) | |
733 | goto discard_it; | |
734 | ||
735 | hdr = icmp6_hdr(skb); | |
736 | ||
737 | type = hdr->icmp6_type; | |
738 | ||
739 | ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type); | |
740 | ||
741 | switch (type) { | |
742 | case ICMPV6_ECHO_REQUEST: | |
743 | icmpv6_echo_reply(skb); | |
744 | break; | |
745 | ||
746 | case ICMPV6_ECHO_REPLY: | |
747 | success = ping_rcv(skb); | |
748 | break; | |
749 | ||
750 | case ICMPV6_PKT_TOOBIG: | |
751 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
752 | standard destination cache. Seems, only "advanced" | |
753 | destination cache will allow to solve this problem | |
754 | --ANK (980726) | |
755 | */ | |
756 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
757 | goto discard_it; | |
758 | hdr = icmp6_hdr(skb); | |
759 | ||
760 | /* | |
761 | * Drop through to notify | |
762 | */ | |
763 | ||
764 | case ICMPV6_DEST_UNREACH: | |
765 | case ICMPV6_TIME_EXCEED: | |
766 | case ICMPV6_PARAMPROB: | |
767 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
768 | break; | |
769 | ||
770 | case NDISC_ROUTER_SOLICITATION: | |
771 | case NDISC_ROUTER_ADVERTISEMENT: | |
772 | case NDISC_NEIGHBOUR_SOLICITATION: | |
773 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
774 | case NDISC_REDIRECT: | |
775 | ndisc_rcv(skb); | |
776 | break; | |
777 | ||
778 | case ICMPV6_MGM_QUERY: | |
779 | igmp6_event_query(skb); | |
780 | break; | |
781 | ||
782 | case ICMPV6_MGM_REPORT: | |
783 | igmp6_event_report(skb); | |
784 | break; | |
785 | ||
786 | case ICMPV6_MGM_REDUCTION: | |
787 | case ICMPV6_NI_QUERY: | |
788 | case ICMPV6_NI_REPLY: | |
789 | case ICMPV6_MLD2_REPORT: | |
790 | case ICMPV6_DHAAD_REQUEST: | |
791 | case ICMPV6_DHAAD_REPLY: | |
792 | case ICMPV6_MOBILE_PREFIX_SOL: | |
793 | case ICMPV6_MOBILE_PREFIX_ADV: | |
794 | break; | |
795 | ||
796 | default: | |
797 | /* informational */ | |
798 | if (type & ICMPV6_INFOMSG_MASK) | |
799 | break; | |
800 | ||
801 | net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n", | |
802 | saddr, daddr); | |
803 | ||
804 | /* | |
805 | * error of unknown type. | |
806 | * must pass to upper level | |
807 | */ | |
808 | ||
809 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
810 | } | |
811 | ||
812 | /* until the v6 path can be better sorted assume failure and | |
813 | * preserve the status quo behaviour for the rest of the paths to here | |
814 | */ | |
815 | if (success) | |
816 | consume_skb(skb); | |
817 | else | |
818 | kfree_skb(skb); | |
819 | ||
820 | return 0; | |
821 | ||
822 | csum_error: | |
823 | __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS); | |
824 | discard_it: | |
825 | __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS); | |
826 | drop_no_count: | |
827 | kfree_skb(skb); | |
828 | return 0; | |
829 | } | |
830 | ||
831 | void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6, | |
832 | u8 type, | |
833 | const struct in6_addr *saddr, | |
834 | const struct in6_addr *daddr, | |
835 | int oif) | |
836 | { | |
837 | memset(fl6, 0, sizeof(*fl6)); | |
838 | fl6->saddr = *saddr; | |
839 | fl6->daddr = *daddr; | |
840 | fl6->flowi6_proto = IPPROTO_ICMPV6; | |
841 | fl6->fl6_icmp_type = type; | |
842 | fl6->fl6_icmp_code = 0; | |
843 | fl6->flowi6_oif = oif; | |
844 | security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); | |
845 | } | |
846 | ||
847 | static int __net_init icmpv6_sk_init(struct net *net) | |
848 | { | |
849 | struct sock *sk; | |
850 | int err, i, j; | |
851 | ||
852 | net->ipv6.icmp_sk = | |
853 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
854 | if (!net->ipv6.icmp_sk) | |
855 | return -ENOMEM; | |
856 | ||
857 | for_each_possible_cpu(i) { | |
858 | err = inet_ctl_sock_create(&sk, PF_INET6, | |
859 | SOCK_RAW, IPPROTO_ICMPV6, net); | |
860 | if (err < 0) { | |
861 | pr_err("Failed to initialize the ICMP6 control socket (err %d)\n", | |
862 | err); | |
863 | goto fail; | |
864 | } | |
865 | ||
866 | net->ipv6.icmp_sk[i] = sk; | |
867 | ||
868 | /* Enough space for 2 64K ICMP packets, including | |
869 | * sk_buff struct overhead. | |
870 | */ | |
871 | sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); | |
872 | } | |
873 | return 0; | |
874 | ||
875 | fail: | |
876 | for (j = 0; j < i; j++) | |
877 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); | |
878 | kfree(net->ipv6.icmp_sk); | |
879 | return err; | |
880 | } | |
881 | ||
882 | static void __net_exit icmpv6_sk_exit(struct net *net) | |
883 | { | |
884 | int i; | |
885 | ||
886 | for_each_possible_cpu(i) { | |
887 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); | |
888 | } | |
889 | kfree(net->ipv6.icmp_sk); | |
890 | } | |
891 | ||
892 | static struct pernet_operations icmpv6_sk_ops = { | |
893 | .init = icmpv6_sk_init, | |
894 | .exit = icmpv6_sk_exit, | |
895 | }; | |
896 | ||
897 | int __init icmpv6_init(void) | |
898 | { | |
899 | int err; | |
900 | ||
901 | err = register_pernet_subsys(&icmpv6_sk_ops); | |
902 | if (err < 0) | |
903 | return err; | |
904 | ||
905 | err = -EAGAIN; | |
906 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) | |
907 | goto fail; | |
908 | ||
909 | err = inet6_register_icmp_sender(icmp6_send); | |
910 | if (err) | |
911 | goto sender_reg_err; | |
912 | return 0; | |
913 | ||
914 | sender_reg_err: | |
915 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); | |
916 | fail: | |
917 | pr_err("Failed to register ICMP6 protocol\n"); | |
918 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
919 | return err; | |
920 | } | |
921 | ||
922 | void icmpv6_cleanup(void) | |
923 | { | |
924 | inet6_unregister_icmp_sender(icmp6_send); | |
925 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
926 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); | |
927 | } | |
928 | ||
929 | ||
930 | static const struct icmp6_err { | |
931 | int err; | |
932 | int fatal; | |
933 | } tab_unreach[] = { | |
934 | { /* NOROUTE */ | |
935 | .err = ENETUNREACH, | |
936 | .fatal = 0, | |
937 | }, | |
938 | { /* ADM_PROHIBITED */ | |
939 | .err = EACCES, | |
940 | .fatal = 1, | |
941 | }, | |
942 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
943 | .err = EHOSTUNREACH, | |
944 | .fatal = 0, | |
945 | }, | |
946 | { /* ADDR_UNREACH */ | |
947 | .err = EHOSTUNREACH, | |
948 | .fatal = 0, | |
949 | }, | |
950 | { /* PORT_UNREACH */ | |
951 | .err = ECONNREFUSED, | |
952 | .fatal = 1, | |
953 | }, | |
954 | { /* POLICY_FAIL */ | |
955 | .err = EACCES, | |
956 | .fatal = 1, | |
957 | }, | |
958 | { /* REJECT_ROUTE */ | |
959 | .err = EACCES, | |
960 | .fatal = 1, | |
961 | }, | |
962 | }; | |
963 | ||
964 | int icmpv6_err_convert(u8 type, u8 code, int *err) | |
965 | { | |
966 | int fatal = 0; | |
967 | ||
968 | *err = EPROTO; | |
969 | ||
970 | switch (type) { | |
971 | case ICMPV6_DEST_UNREACH: | |
972 | fatal = 1; | |
973 | if (code < ARRAY_SIZE(tab_unreach)) { | |
974 | *err = tab_unreach[code].err; | |
975 | fatal = tab_unreach[code].fatal; | |
976 | } | |
977 | break; | |
978 | ||
979 | case ICMPV6_PKT_TOOBIG: | |
980 | *err = EMSGSIZE; | |
981 | break; | |
982 | ||
983 | case ICMPV6_PARAMPROB: | |
984 | *err = EPROTO; | |
985 | fatal = 1; | |
986 | break; | |
987 | ||
988 | case ICMPV6_TIME_EXCEED: | |
989 | *err = EHOSTUNREACH; | |
990 | break; | |
991 | } | |
992 | ||
993 | return fatal; | |
994 | } | |
995 | EXPORT_SYMBOL(icmpv6_err_convert); | |
996 | ||
997 | #ifdef CONFIG_SYSCTL | |
998 | static struct ctl_table ipv6_icmp_table_template[] = { | |
999 | { | |
1000 | .procname = "ratelimit", | |
1001 | .data = &init_net.ipv6.sysctl.icmpv6_time, | |
1002 | .maxlen = sizeof(int), | |
1003 | .mode = 0644, | |
1004 | .proc_handler = proc_dointvec_ms_jiffies, | |
1005 | }, | |
1006 | { }, | |
1007 | }; | |
1008 | ||
1009 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) | |
1010 | { | |
1011 | struct ctl_table *table; | |
1012 | ||
1013 | table = kmemdup(ipv6_icmp_table_template, | |
1014 | sizeof(ipv6_icmp_table_template), | |
1015 | GFP_KERNEL); | |
1016 | ||
1017 | if (table) | |
1018 | table[0].data = &net->ipv6.sysctl.icmpv6_time; | |
1019 | ||
1020 | return table; | |
1021 | } | |
1022 | #endif |