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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 */
78static inline struct sock *icmpv6_sk(struct net *net)
79{
80 return net->ipv6.icmp_sk[smp_processor_id()];
81}
82
83static int icmpv6_rcv(struct sk_buff *skb);
84
85static const struct inet6_protocol icmpv6_protocol = {
86 .handler = icmpv6_rcv,
87 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
88};
89
90static __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
108static __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 */
116void 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
133static 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 */
160static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
161 struct flowi6 *fl6)
162{
163 struct dst_entry *dst;
164 struct net *net = sock_net(sk);
165 bool res = false;
166
167 /* Informational messages are not limited. */
168 if (type & ICMPV6_INFOMSG_MASK)
169 return true;
170
171 /* Do not limit pmtu discovery, it would break it. */
172 if (type == ICMPV6_PKT_TOOBIG)
173 return true;
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, fl6);
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 = true;
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 if (!rt->rt6i_peer)
195 rt6_bind_peer(rt, 1);
196 res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo);
197 }
198 dst_release(dst);
199 return res;
200}
201
202/*
203 * an inline helper for the "simple" if statement below
204 * checks if parameter problem report is caused by an
205 * unrecognized IPv6 option that has the Option Type
206 * highest-order two bits set to 10
207 */
208
209static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset)
210{
211 u8 _optval, *op;
212
213 offset += skb_network_offset(skb);
214 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
215 if (op == NULL)
216 return 1;
217 return (*op & 0xC0) == 0x80;
218}
219
220static int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, struct icmp6hdr *thdr, int len)
221{
222 struct sk_buff *skb;
223 struct icmp6hdr *icmp6h;
224 int err = 0;
225
226 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
227 goto out;
228
229 icmp6h = icmp6_hdr(skb);
230 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
231 icmp6h->icmp6_cksum = 0;
232
233 if (skb_queue_len(&sk->sk_write_queue) == 1) {
234 skb->csum = csum_partial(icmp6h,
235 sizeof(struct icmp6hdr), skb->csum);
236 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
237 &fl6->daddr,
238 len, fl6->flowi6_proto,
239 skb->csum);
240 } else {
241 __wsum tmp_csum = 0;
242
243 skb_queue_walk(&sk->sk_write_queue, skb) {
244 tmp_csum = csum_add(tmp_csum, skb->csum);
245 }
246
247 tmp_csum = csum_partial(icmp6h,
248 sizeof(struct icmp6hdr), tmp_csum);
249 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
250 &fl6->daddr,
251 len, fl6->flowi6_proto,
252 tmp_csum);
253 }
254 ip6_push_pending_frames(sk);
255out:
256 return err;
257}
258
259struct icmpv6_msg {
260 struct sk_buff *skb;
261 int offset;
262 uint8_t type;
263};
264
265static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
266{
267 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
268 struct sk_buff *org_skb = msg->skb;
269 __wsum csum = 0;
270
271 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
272 to, len, csum);
273 skb->csum = csum_block_add(skb->csum, csum, odd);
274 if (!(msg->type & ICMPV6_INFOMSG_MASK))
275 nf_ct_attach(skb, org_skb);
276 return 0;
277}
278
279#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
280static void mip6_addr_swap(struct sk_buff *skb)
281{
282 struct ipv6hdr *iph = ipv6_hdr(skb);
283 struct inet6_skb_parm *opt = IP6CB(skb);
284 struct ipv6_destopt_hao *hao;
285 struct in6_addr tmp;
286 int off;
287
288 if (opt->dsthao) {
289 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
290 if (likely(off >= 0)) {
291 hao = (struct ipv6_destopt_hao *)
292 (skb_network_header(skb) + off);
293 ipv6_addr_copy(&tmp, &iph->saddr);
294 ipv6_addr_copy(&iph->saddr, &hao->addr);
295 ipv6_addr_copy(&hao->addr, &tmp);
296 }
297 }
298}
299#else
300static inline void mip6_addr_swap(struct sk_buff *skb) {}
301#endif
302
303static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
304 struct sock *sk, struct flowi6 *fl6)
305{
306 struct dst_entry *dst, *dst2;
307 struct flowi6 fl2;
308 int err;
309
310 err = ip6_dst_lookup(sk, &dst, fl6);
311 if (err)
312 return ERR_PTR(err);
313
314 /*
315 * We won't send icmp if the destination is known
316 * anycast.
317 */
318 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) {
319 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n");
320 dst_release(dst);
321 return ERR_PTR(-EINVAL);
322 }
323
324 /* No need to clone since we're just using its address. */
325 dst2 = dst;
326
327 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
328 if (!IS_ERR(dst)) {
329 if (dst != dst2)
330 return dst;
331 } else {
332 if (PTR_ERR(dst) == -EPERM)
333 dst = NULL;
334 else
335 return dst;
336 }
337
338 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
339 if (err)
340 goto relookup_failed;
341
342 err = ip6_dst_lookup(sk, &dst2, &fl2);
343 if (err)
344 goto relookup_failed;
345
346 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
347 if (!IS_ERR(dst2)) {
348 dst_release(dst);
349 dst = dst2;
350 } else {
351 err = PTR_ERR(dst2);
352 if (err == -EPERM) {
353 dst_release(dst);
354 return dst2;
355 } else
356 goto relookup_failed;
357 }
358
359relookup_failed:
360 if (dst)
361 return dst;
362 return ERR_PTR(err);
363}
364
365/*
366 * Send an ICMP message in response to a packet in error
367 */
368void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
369{
370 struct net *net = dev_net(skb->dev);
371 struct inet6_dev *idev = NULL;
372 struct ipv6hdr *hdr = ipv6_hdr(skb);
373 struct sock *sk;
374 struct ipv6_pinfo *np;
375 const struct in6_addr *saddr = NULL;
376 struct dst_entry *dst;
377 struct icmp6hdr tmp_hdr;
378 struct flowi6 fl6;
379 struct icmpv6_msg msg;
380 int iif = 0;
381 int addr_type = 0;
382 int len;
383 int hlimit;
384 int err = 0;
385
386 if ((u8 *)hdr < skb->head ||
387 (skb->network_header + sizeof(*hdr)) > skb->tail)
388 return;
389
390 /*
391 * Make sure we respect the rules
392 * i.e. RFC 1885 2.4(e)
393 * Rule (e.1) is enforced by not using icmpv6_send
394 * in any code that processes icmp errors.
395 */
396 addr_type = ipv6_addr_type(&hdr->daddr);
397
398 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0))
399 saddr = &hdr->daddr;
400
401 /*
402 * Dest addr check
403 */
404
405 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) {
406 if (type != ICMPV6_PKT_TOOBIG &&
407 !(type == ICMPV6_PARAMPROB &&
408 code == ICMPV6_UNK_OPTION &&
409 (opt_unrec(skb, info))))
410 return;
411
412 saddr = NULL;
413 }
414
415 addr_type = ipv6_addr_type(&hdr->saddr);
416
417 /*
418 * Source addr check
419 */
420
421 if (addr_type & IPV6_ADDR_LINKLOCAL)
422 iif = skb->dev->ifindex;
423
424 /*
425 * Must not send error if the source does not uniquely
426 * identify a single node (RFC2463 Section 2.4).
427 * We check unspecified / multicast addresses here,
428 * and anycast addresses will be checked later.
429 */
430 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
431 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n");
432 return;
433 }
434
435 /*
436 * Never answer to a ICMP packet.
437 */
438 if (is_ineligible(skb)) {
439 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n");
440 return;
441 }
442
443 mip6_addr_swap(skb);
444
445 memset(&fl6, 0, sizeof(fl6));
446 fl6.flowi6_proto = IPPROTO_ICMPV6;
447 ipv6_addr_copy(&fl6.daddr, &hdr->saddr);
448 if (saddr)
449 ipv6_addr_copy(&fl6.saddr, saddr);
450 fl6.flowi6_oif = iif;
451 fl6.fl6_icmp_type = type;
452 fl6.fl6_icmp_code = code;
453 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
454
455 sk = icmpv6_xmit_lock(net);
456 if (sk == NULL)
457 return;
458 np = inet6_sk(sk);
459
460 if (!icmpv6_xrlim_allow(sk, type, &fl6))
461 goto out;
462
463 tmp_hdr.icmp6_type = type;
464 tmp_hdr.icmp6_code = code;
465 tmp_hdr.icmp6_cksum = 0;
466 tmp_hdr.icmp6_pointer = htonl(info);
467
468 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
469 fl6.flowi6_oif = np->mcast_oif;
470
471 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
472 if (IS_ERR(dst))
473 goto out;
474
475 if (ipv6_addr_is_multicast(&fl6.daddr))
476 hlimit = np->mcast_hops;
477 else
478 hlimit = np->hop_limit;
479 if (hlimit < 0)
480 hlimit = ip6_dst_hoplimit(dst);
481
482 msg.skb = skb;
483 msg.offset = skb_network_offset(skb);
484 msg.type = type;
485
486 len = skb->len - msg.offset;
487 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
488 if (len < 0) {
489 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n");
490 goto out_dst_release;
491 }
492
493 idev = in6_dev_get(skb->dev);
494
495 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
496 len + sizeof(struct icmp6hdr),
497 sizeof(struct icmp6hdr), hlimit,
498 np->tclass, NULL, &fl6, (struct rt6_info*)dst,
499 MSG_DONTWAIT, np->dontfrag);
500 if (err) {
501 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
502 ip6_flush_pending_frames(sk);
503 goto out_put;
504 }
505 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, len + sizeof(struct icmp6hdr));
506
507out_put:
508 if (likely(idev != NULL))
509 in6_dev_put(idev);
510out_dst_release:
511 dst_release(dst);
512out:
513 icmpv6_xmit_unlock(sk);
514}
515
516EXPORT_SYMBOL(icmpv6_send);
517
518static void icmpv6_echo_reply(struct sk_buff *skb)
519{
520 struct net *net = dev_net(skb->dev);
521 struct sock *sk;
522 struct inet6_dev *idev;
523 struct ipv6_pinfo *np;
524 const struct in6_addr *saddr = NULL;
525 struct icmp6hdr *icmph = icmp6_hdr(skb);
526 struct icmp6hdr tmp_hdr;
527 struct flowi6 fl6;
528 struct icmpv6_msg msg;
529 struct dst_entry *dst;
530 int err = 0;
531 int hlimit;
532
533 saddr = &ipv6_hdr(skb)->daddr;
534
535 if (!ipv6_unicast_destination(skb))
536 saddr = NULL;
537
538 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
539 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
540
541 memset(&fl6, 0, sizeof(fl6));
542 fl6.flowi6_proto = IPPROTO_ICMPV6;
543 ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->saddr);
544 if (saddr)
545 ipv6_addr_copy(&fl6.saddr, saddr);
546 fl6.flowi6_oif = skb->dev->ifindex;
547 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
548 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
549
550 sk = icmpv6_xmit_lock(net);
551 if (sk == NULL)
552 return;
553 np = inet6_sk(sk);
554
555 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
556 fl6.flowi6_oif = np->mcast_oif;
557
558 err = ip6_dst_lookup(sk, &dst, &fl6);
559 if (err)
560 goto out;
561 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
562 if (IS_ERR(dst))
563 goto out;
564
565 if (ipv6_addr_is_multicast(&fl6.daddr))
566 hlimit = np->mcast_hops;
567 else
568 hlimit = np->hop_limit;
569 if (hlimit < 0)
570 hlimit = ip6_dst_hoplimit(dst);
571
572 idev = in6_dev_get(skb->dev);
573
574 msg.skb = skb;
575 msg.offset = 0;
576 msg.type = ICMPV6_ECHO_REPLY;
577
578 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
579 sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6,
580 (struct rt6_info*)dst, MSG_DONTWAIT,
581 np->dontfrag);
582
583 if (err) {
584 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
585 ip6_flush_pending_frames(sk);
586 goto out_put;
587 }
588 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, skb->len + sizeof(struct icmp6hdr));
589
590out_put:
591 if (likely(idev != NULL))
592 in6_dev_put(idev);
593 dst_release(dst);
594out:
595 icmpv6_xmit_unlock(sk);
596}
597
598static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
599{
600 const struct inet6_protocol *ipprot;
601 int inner_offset;
602 int hash;
603 u8 nexthdr;
604
605 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
606 return;
607
608 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
609 if (ipv6_ext_hdr(nexthdr)) {
610 /* now skip over extension headers */
611 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
612 if (inner_offset<0)
613 return;
614 } else {
615 inner_offset = sizeof(struct ipv6hdr);
616 }
617
618 /* Checkin header including 8 bytes of inner protocol header. */
619 if (!pskb_may_pull(skb, inner_offset+8))
620 return;
621
622 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
623 Without this we will not able f.e. to make source routed
624 pmtu discovery.
625 Corresponding argument (opt) to notifiers is already added.
626 --ANK (980726)
627 */
628
629 hash = nexthdr & (MAX_INET_PROTOS - 1);
630
631 rcu_read_lock();
632 ipprot = rcu_dereference(inet6_protos[hash]);
633 if (ipprot && ipprot->err_handler)
634 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
635 rcu_read_unlock();
636
637 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
638}
639
640/*
641 * Handle icmp messages
642 */
643
644static int icmpv6_rcv(struct sk_buff *skb)
645{
646 struct net_device *dev = skb->dev;
647 struct inet6_dev *idev = __in6_dev_get(dev);
648 const struct in6_addr *saddr, *daddr;
649 const struct ipv6hdr *orig_hdr;
650 struct icmp6hdr *hdr;
651 u8 type;
652
653 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
654 struct sec_path *sp = skb_sec_path(skb);
655 int nh;
656
657 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
658 XFRM_STATE_ICMP))
659 goto drop_no_count;
660
661 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr)))
662 goto drop_no_count;
663
664 nh = skb_network_offset(skb);
665 skb_set_network_header(skb, sizeof(*hdr));
666
667 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
668 goto drop_no_count;
669
670 skb_set_network_header(skb, nh);
671 }
672
673 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
674
675 saddr = &ipv6_hdr(skb)->saddr;
676 daddr = &ipv6_hdr(skb)->daddr;
677
678 /* Perform checksum. */
679 switch (skb->ip_summed) {
680 case CHECKSUM_COMPLETE:
681 if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
682 skb->csum))
683 break;
684 /* fall through */
685 case CHECKSUM_NONE:
686 skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len,
687 IPPROTO_ICMPV6, 0));
688 if (__skb_checksum_complete(skb)) {
689 LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n",
690 saddr, daddr);
691 goto discard_it;
692 }
693 }
694
695 if (!pskb_pull(skb, sizeof(*hdr)))
696 goto discard_it;
697
698 hdr = icmp6_hdr(skb);
699
700 type = hdr->icmp6_type;
701
702 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
703
704 switch (type) {
705 case ICMPV6_ECHO_REQUEST:
706 icmpv6_echo_reply(skb);
707 break;
708
709 case ICMPV6_ECHO_REPLY:
710 /* we couldn't care less */
711 break;
712
713 case ICMPV6_PKT_TOOBIG:
714 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
715 standard destination cache. Seems, only "advanced"
716 destination cache will allow to solve this problem
717 --ANK (980726)
718 */
719 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
720 goto discard_it;
721 hdr = icmp6_hdr(skb);
722 orig_hdr = (struct ipv6hdr *) (hdr + 1);
723 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev,
724 ntohl(hdr->icmp6_mtu));
725
726 /*
727 * Drop through to notify
728 */
729
730 case ICMPV6_DEST_UNREACH:
731 case ICMPV6_TIME_EXCEED:
732 case ICMPV6_PARAMPROB:
733 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
734 break;
735
736 case NDISC_ROUTER_SOLICITATION:
737 case NDISC_ROUTER_ADVERTISEMENT:
738 case NDISC_NEIGHBOUR_SOLICITATION:
739 case NDISC_NEIGHBOUR_ADVERTISEMENT:
740 case NDISC_REDIRECT:
741 ndisc_rcv(skb);
742 break;
743
744 case ICMPV6_MGM_QUERY:
745 igmp6_event_query(skb);
746 break;
747
748 case ICMPV6_MGM_REPORT:
749 igmp6_event_report(skb);
750 break;
751
752 case ICMPV6_MGM_REDUCTION:
753 case ICMPV6_NI_QUERY:
754 case ICMPV6_NI_REPLY:
755 case ICMPV6_MLD2_REPORT:
756 case ICMPV6_DHAAD_REQUEST:
757 case ICMPV6_DHAAD_REPLY:
758 case ICMPV6_MOBILE_PREFIX_SOL:
759 case ICMPV6_MOBILE_PREFIX_ADV:
760 break;
761
762 default:
763 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n");
764
765 /* informational */
766 if (type & ICMPV6_INFOMSG_MASK)
767 break;
768
769 /*
770 * error of unknown type.
771 * must pass to upper level
772 */
773
774 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
775 }
776
777 kfree_skb(skb);
778 return 0;
779
780discard_it:
781 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
782drop_no_count:
783 kfree_skb(skb);
784 return 0;
785}
786
787void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
788 u8 type,
789 const struct in6_addr *saddr,
790 const struct in6_addr *daddr,
791 int oif)
792{
793 memset(fl6, 0, sizeof(*fl6));
794 ipv6_addr_copy(&fl6->saddr, saddr);
795 ipv6_addr_copy(&fl6->daddr, daddr);
796 fl6->flowi6_proto = IPPROTO_ICMPV6;
797 fl6->fl6_icmp_type = type;
798 fl6->fl6_icmp_code = 0;
799 fl6->flowi6_oif = oif;
800 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
801}
802
803/*
804 * Special lock-class for __icmpv6_sk:
805 */
806static struct lock_class_key icmpv6_socket_sk_dst_lock_key;
807
808static int __net_init icmpv6_sk_init(struct net *net)
809{
810 struct sock *sk;
811 int err, i, j;
812
813 net->ipv6.icmp_sk =
814 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
815 if (net->ipv6.icmp_sk == NULL)
816 return -ENOMEM;
817
818 for_each_possible_cpu(i) {
819 err = inet_ctl_sock_create(&sk, PF_INET6,
820 SOCK_RAW, IPPROTO_ICMPV6, net);
821 if (err < 0) {
822 printk(KERN_ERR
823 "Failed to initialize the ICMP6 control socket "
824 "(err %d).\n",
825 err);
826 goto fail;
827 }
828
829 net->ipv6.icmp_sk[i] = sk;
830
831 /*
832 * Split off their lock-class, because sk->sk_dst_lock
833 * gets used from softirqs, which is safe for
834 * __icmpv6_sk (because those never get directly used
835 * via userspace syscalls), but unsafe for normal sockets.
836 */
837 lockdep_set_class(&sk->sk_dst_lock,
838 &icmpv6_socket_sk_dst_lock_key);
839
840 /* Enough space for 2 64K ICMP packets, including
841 * sk_buff struct overhead.
842 */
843 sk->sk_sndbuf =
844 (2 * ((64 * 1024) + sizeof(struct sk_buff)));
845 }
846 return 0;
847
848 fail:
849 for (j = 0; j < i; j++)
850 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
851 kfree(net->ipv6.icmp_sk);
852 return err;
853}
854
855static void __net_exit icmpv6_sk_exit(struct net *net)
856{
857 int i;
858
859 for_each_possible_cpu(i) {
860 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
861 }
862 kfree(net->ipv6.icmp_sk);
863}
864
865static struct pernet_operations icmpv6_sk_ops = {
866 .init = icmpv6_sk_init,
867 .exit = icmpv6_sk_exit,
868};
869
870int __init icmpv6_init(void)
871{
872 int err;
873
874 err = register_pernet_subsys(&icmpv6_sk_ops);
875 if (err < 0)
876 return err;
877
878 err = -EAGAIN;
879 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
880 goto fail;
881 return 0;
882
883fail:
884 printk(KERN_ERR "Failed to register ICMP6 protocol\n");
885 unregister_pernet_subsys(&icmpv6_sk_ops);
886 return err;
887}
888
889void icmpv6_cleanup(void)
890{
891 unregister_pernet_subsys(&icmpv6_sk_ops);
892 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
893}
894
895
896static const struct icmp6_err {
897 int err;
898 int fatal;
899} tab_unreach[] = {
900 { /* NOROUTE */
901 .err = ENETUNREACH,
902 .fatal = 0,
903 },
904 { /* ADM_PROHIBITED */
905 .err = EACCES,
906 .fatal = 1,
907 },
908 { /* Was NOT_NEIGHBOUR, now reserved */
909 .err = EHOSTUNREACH,
910 .fatal = 0,
911 },
912 { /* ADDR_UNREACH */
913 .err = EHOSTUNREACH,
914 .fatal = 0,
915 },
916 { /* PORT_UNREACH */
917 .err = ECONNREFUSED,
918 .fatal = 1,
919 },
920};
921
922int icmpv6_err_convert(u8 type, u8 code, int *err)
923{
924 int fatal = 0;
925
926 *err = EPROTO;
927
928 switch (type) {
929 case ICMPV6_DEST_UNREACH:
930 fatal = 1;
931 if (code <= ICMPV6_PORT_UNREACH) {
932 *err = tab_unreach[code].err;
933 fatal = tab_unreach[code].fatal;
934 }
935 break;
936
937 case ICMPV6_PKT_TOOBIG:
938 *err = EMSGSIZE;
939 break;
940
941 case ICMPV6_PARAMPROB:
942 *err = EPROTO;
943 fatal = 1;
944 break;
945
946 case ICMPV6_TIME_EXCEED:
947 *err = EHOSTUNREACH;
948 break;
949 }
950
951 return fatal;
952}
953
954EXPORT_SYMBOL(icmpv6_err_convert);
955
956#ifdef CONFIG_SYSCTL
957ctl_table ipv6_icmp_table_template[] = {
958 {
959 .procname = "ratelimit",
960 .data = &init_net.ipv6.sysctl.icmpv6_time,
961 .maxlen = sizeof(int),
962 .mode = 0644,
963 .proc_handler = proc_dointvec_ms_jiffies,
964 },
965 { },
966};
967
968struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
969{
970 struct ctl_table *table;
971
972 table = kmemdup(ipv6_icmp_table_template,
973 sizeof(ipv6_icmp_table_template),
974 GFP_KERNEL);
975
976 if (table)
977 table[0].data = &net->ipv6.sysctl.icmpv6_time;
978
979 return table;
980}
981#endif
982
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 */
82static inline struct sock *icmpv6_sk(struct net *net)
83{
84 return net->ipv6.icmp_sk[smp_processor_id()];
85}
86
87static 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
104static int icmpv6_rcv(struct sk_buff *skb);
105
106static 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
112static __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
130static __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
146static 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 */
173static 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
228static 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
239int 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);
276out:
277 return err;
278}
279
280struct icmpv6_msg {
281 struct sk_buff *skb;
282 int offset;
283 uint8_t type;
284};
285
286static 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)
301static 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
321static inline void mip6_addr_swap(struct sk_buff *skb) {}
322#endif
323
324static 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
382relookup_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 */
391static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
392{
393 struct net *net = dev_net(skb->dev);
394 struct inet6_dev *idev = NULL;
395 struct ipv6hdr *hdr = ipv6_hdr(skb);
396 struct sock *sk;
397 struct ipv6_pinfo *np;
398 const struct in6_addr *saddr = NULL;
399 struct dst_entry *dst;
400 struct icmp6hdr tmp_hdr;
401 struct flowi6 fl6;
402 struct icmpv6_msg msg;
403 int iif = 0;
404 int addr_type = 0;
405 int len;
406 int hlimit;
407 int err = 0;
408 u32 mark = IP6_REPLY_MARK(net, skb->mark);
409
410 if ((u8 *)hdr < skb->head ||
411 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
412 return;
413
414 /*
415 * Make sure we respect the rules
416 * i.e. RFC 1885 2.4(e)
417 * Rule (e.1) is enforced by not using icmp6_send
418 * in any code that processes icmp errors.
419 */
420 addr_type = ipv6_addr_type(&hdr->daddr);
421
422 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
423 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
424 saddr = &hdr->daddr;
425
426 /*
427 * Dest addr check
428 */
429
430 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
431 if (type != ICMPV6_PKT_TOOBIG &&
432 !(type == ICMPV6_PARAMPROB &&
433 code == ICMPV6_UNK_OPTION &&
434 (opt_unrec(skb, info))))
435 return;
436
437 saddr = NULL;
438 }
439
440 addr_type = ipv6_addr_type(&hdr->saddr);
441
442 /*
443 * Source addr check
444 */
445
446 if (__ipv6_addr_needs_scope_id(addr_type))
447 iif = skb->dev->ifindex;
448 else
449 iif = l3mdev_master_ifindex(skb->dev);
450
451 /*
452 * Must not send error if the source does not uniquely
453 * identify a single node (RFC2463 Section 2.4).
454 * We check unspecified / multicast addresses here,
455 * and anycast addresses will be checked later.
456 */
457 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
458 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
459 &hdr->saddr, &hdr->daddr);
460 return;
461 }
462
463 /*
464 * Never answer to a ICMP packet.
465 */
466 if (is_ineligible(skb)) {
467 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
468 &hdr->saddr, &hdr->daddr);
469 return;
470 }
471
472 mip6_addr_swap(skb);
473
474 memset(&fl6, 0, sizeof(fl6));
475 fl6.flowi6_proto = IPPROTO_ICMPV6;
476 fl6.daddr = hdr->saddr;
477 if (saddr)
478 fl6.saddr = *saddr;
479 fl6.flowi6_mark = mark;
480 fl6.flowi6_oif = iif;
481 fl6.fl6_icmp_type = type;
482 fl6.fl6_icmp_code = code;
483 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
484
485 sk = icmpv6_xmit_lock(net);
486 if (!sk)
487 return;
488 sk->sk_mark = mark;
489 np = inet6_sk(sk);
490
491 if (!icmpv6_xrlim_allow(sk, type, &fl6))
492 goto out;
493
494 tmp_hdr.icmp6_type = type;
495 tmp_hdr.icmp6_code = code;
496 tmp_hdr.icmp6_cksum = 0;
497 tmp_hdr.icmp6_pointer = htonl(info);
498
499 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
500 fl6.flowi6_oif = np->mcast_oif;
501 else if (!fl6.flowi6_oif)
502 fl6.flowi6_oif = np->ucast_oif;
503
504 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
505 if (IS_ERR(dst))
506 goto out;
507
508 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
509
510 msg.skb = skb;
511 msg.offset = skb_network_offset(skb);
512 msg.type = type;
513
514 len = skb->len - msg.offset;
515 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
516 if (len < 0) {
517 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
518 &hdr->saddr, &hdr->daddr);
519 goto out_dst_release;
520 }
521
522 rcu_read_lock();
523 idev = __in6_dev_get(skb->dev);
524
525 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
526 len + sizeof(struct icmp6hdr),
527 sizeof(struct icmp6hdr), hlimit,
528 np->tclass, NULL, &fl6, (struct rt6_info *)dst,
529 MSG_DONTWAIT, np->dontfrag);
530 if (err) {
531 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
532 ip6_flush_pending_frames(sk);
533 } else {
534 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
535 len + sizeof(struct icmp6hdr));
536 }
537 rcu_read_unlock();
538out_dst_release:
539 dst_release(dst);
540out:
541 icmpv6_xmit_unlock(sk);
542}
543
544/* Slightly more convenient version of icmp6_send.
545 */
546void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
547{
548 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
549 kfree_skb(skb);
550}
551
552static void icmpv6_echo_reply(struct sk_buff *skb)
553{
554 struct net *net = dev_net(skb->dev);
555 struct sock *sk;
556 struct inet6_dev *idev;
557 struct ipv6_pinfo *np;
558 const struct in6_addr *saddr = NULL;
559 struct icmp6hdr *icmph = icmp6_hdr(skb);
560 struct icmp6hdr tmp_hdr;
561 struct flowi6 fl6;
562 struct icmpv6_msg msg;
563 struct dst_entry *dst;
564 int err = 0;
565 int hlimit;
566 u8 tclass;
567 u32 mark = IP6_REPLY_MARK(net, skb->mark);
568
569 saddr = &ipv6_hdr(skb)->daddr;
570
571 if (!ipv6_unicast_destination(skb) &&
572 !(net->ipv6.sysctl.anycast_src_echo_reply &&
573 ipv6_anycast_destination(skb_dst(skb), saddr)))
574 saddr = NULL;
575
576 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
577 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
578
579 memset(&fl6, 0, sizeof(fl6));
580 fl6.flowi6_proto = IPPROTO_ICMPV6;
581 fl6.daddr = ipv6_hdr(skb)->saddr;
582 if (saddr)
583 fl6.saddr = *saddr;
584 fl6.flowi6_oif = l3mdev_fib_oif(skb->dev);
585 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
586 fl6.flowi6_mark = mark;
587 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
588
589 sk = icmpv6_xmit_lock(net);
590 if (!sk)
591 return;
592 sk->sk_mark = mark;
593 np = inet6_sk(sk);
594
595 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
596 fl6.flowi6_oif = np->mcast_oif;
597 else if (!fl6.flowi6_oif)
598 fl6.flowi6_oif = np->ucast_oif;
599
600 err = ip6_dst_lookup(net, sk, &dst, &fl6);
601 if (err)
602 goto out;
603 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
604 if (IS_ERR(dst))
605 goto out;
606
607 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
608
609 idev = __in6_dev_get(skb->dev);
610
611 msg.skb = skb;
612 msg.offset = 0;
613 msg.type = ICMPV6_ECHO_REPLY;
614
615 tclass = ipv6_get_dsfield(ipv6_hdr(skb));
616 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
617 sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl6,
618 (struct rt6_info *)dst, MSG_DONTWAIT,
619 np->dontfrag);
620
621 if (err) {
622 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
623 ip6_flush_pending_frames(sk);
624 } else {
625 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
626 skb->len + sizeof(struct icmp6hdr));
627 }
628 dst_release(dst);
629out:
630 icmpv6_xmit_unlock(sk);
631}
632
633void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
634{
635 const struct inet6_protocol *ipprot;
636 int inner_offset;
637 __be16 frag_off;
638 u8 nexthdr;
639 struct net *net = dev_net(skb->dev);
640
641 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
642 goto out;
643
644 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
645 if (ipv6_ext_hdr(nexthdr)) {
646 /* now skip over extension headers */
647 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
648 &nexthdr, &frag_off);
649 if (inner_offset < 0)
650 goto out;
651 } else {
652 inner_offset = sizeof(struct ipv6hdr);
653 }
654
655 /* Checkin header including 8 bytes of inner protocol header. */
656 if (!pskb_may_pull(skb, inner_offset+8))
657 goto out;
658
659 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
660 Without this we will not able f.e. to make source routed
661 pmtu discovery.
662 Corresponding argument (opt) to notifiers is already added.
663 --ANK (980726)
664 */
665
666 ipprot = rcu_dereference(inet6_protos[nexthdr]);
667 if (ipprot && ipprot->err_handler)
668 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
669
670 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
671 return;
672
673out:
674 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
675}
676
677/*
678 * Handle icmp messages
679 */
680
681static int icmpv6_rcv(struct sk_buff *skb)
682{
683 struct net_device *dev = skb->dev;
684 struct inet6_dev *idev = __in6_dev_get(dev);
685 const struct in6_addr *saddr, *daddr;
686 struct icmp6hdr *hdr;
687 u8 type;
688 bool success = false;
689
690 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
691 struct sec_path *sp = skb_sec_path(skb);
692 int nh;
693
694 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
695 XFRM_STATE_ICMP))
696 goto drop_no_count;
697
698 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
699 goto drop_no_count;
700
701 nh = skb_network_offset(skb);
702 skb_set_network_header(skb, sizeof(*hdr));
703
704 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
705 goto drop_no_count;
706
707 skb_set_network_header(skb, nh);
708 }
709
710 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
711
712 saddr = &ipv6_hdr(skb)->saddr;
713 daddr = &ipv6_hdr(skb)->daddr;
714
715 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
716 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
717 saddr, daddr);
718 goto csum_error;
719 }
720
721 if (!pskb_pull(skb, sizeof(*hdr)))
722 goto discard_it;
723
724 hdr = icmp6_hdr(skb);
725
726 type = hdr->icmp6_type;
727
728 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
729
730 switch (type) {
731 case ICMPV6_ECHO_REQUEST:
732 icmpv6_echo_reply(skb);
733 break;
734
735 case ICMPV6_ECHO_REPLY:
736 success = ping_rcv(skb);
737 break;
738
739 case ICMPV6_PKT_TOOBIG:
740 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
741 standard destination cache. Seems, only "advanced"
742 destination cache will allow to solve this problem
743 --ANK (980726)
744 */
745 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
746 goto discard_it;
747 hdr = icmp6_hdr(skb);
748
749 /*
750 * Drop through to notify
751 */
752
753 case ICMPV6_DEST_UNREACH:
754 case ICMPV6_TIME_EXCEED:
755 case ICMPV6_PARAMPROB:
756 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
757 break;
758
759 case NDISC_ROUTER_SOLICITATION:
760 case NDISC_ROUTER_ADVERTISEMENT:
761 case NDISC_NEIGHBOUR_SOLICITATION:
762 case NDISC_NEIGHBOUR_ADVERTISEMENT:
763 case NDISC_REDIRECT:
764 ndisc_rcv(skb);
765 break;
766
767 case ICMPV6_MGM_QUERY:
768 igmp6_event_query(skb);
769 break;
770
771 case ICMPV6_MGM_REPORT:
772 igmp6_event_report(skb);
773 break;
774
775 case ICMPV6_MGM_REDUCTION:
776 case ICMPV6_NI_QUERY:
777 case ICMPV6_NI_REPLY:
778 case ICMPV6_MLD2_REPORT:
779 case ICMPV6_DHAAD_REQUEST:
780 case ICMPV6_DHAAD_REPLY:
781 case ICMPV6_MOBILE_PREFIX_SOL:
782 case ICMPV6_MOBILE_PREFIX_ADV:
783 break;
784
785 default:
786 /* informational */
787 if (type & ICMPV6_INFOMSG_MASK)
788 break;
789
790 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
791 saddr, daddr);
792
793 /*
794 * error of unknown type.
795 * must pass to upper level
796 */
797
798 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
799 }
800
801 /* until the v6 path can be better sorted assume failure and
802 * preserve the status quo behaviour for the rest of the paths to here
803 */
804 if (success)
805 consume_skb(skb);
806 else
807 kfree_skb(skb);
808
809 return 0;
810
811csum_error:
812 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
813discard_it:
814 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
815drop_no_count:
816 kfree_skb(skb);
817 return 0;
818}
819
820void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
821 u8 type,
822 const struct in6_addr *saddr,
823 const struct in6_addr *daddr,
824 int oif)
825{
826 memset(fl6, 0, sizeof(*fl6));
827 fl6->saddr = *saddr;
828 fl6->daddr = *daddr;
829 fl6->flowi6_proto = IPPROTO_ICMPV6;
830 fl6->fl6_icmp_type = type;
831 fl6->fl6_icmp_code = 0;
832 fl6->flowi6_oif = oif;
833 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
834}
835
836static int __net_init icmpv6_sk_init(struct net *net)
837{
838 struct sock *sk;
839 int err, i, j;
840
841 net->ipv6.icmp_sk =
842 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
843 if (!net->ipv6.icmp_sk)
844 return -ENOMEM;
845
846 for_each_possible_cpu(i) {
847 err = inet_ctl_sock_create(&sk, PF_INET6,
848 SOCK_RAW, IPPROTO_ICMPV6, net);
849 if (err < 0) {
850 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
851 err);
852 goto fail;
853 }
854
855 net->ipv6.icmp_sk[i] = sk;
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
871static 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
881static struct pernet_operations icmpv6_sk_ops = {
882 .init = icmpv6_sk_init,
883 .exit = icmpv6_sk_exit,
884};
885
886int __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
903sender_reg_err:
904 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
905fail:
906 pr_err("Failed to register ICMP6 protocol\n");
907 unregister_pernet_subsys(&icmpv6_sk_ops);
908 return err;
909}
910
911void 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
919static 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
953int 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}
984EXPORT_SYMBOL(icmpv6_err_convert);
985
986#ifdef CONFIG_SYSCTL
987static 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
998struct 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