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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/protocol.h>
61#include <net/raw.h>
62#include <net/rawv6.h>
63#include <net/transp_v6.h>
64#include <net/ip6_route.h>
65#include <net/addrconf.h>
66#include <net/icmp.h>
67#include <net/xfrm.h>
68#include <net/inet_common.h>
69
70#include <asm/uaccess.h>
71
72/*
73 * The ICMP socket(s). This is the most convenient way to flow control
74 * our ICMP output as well as maintain a clean interface throughout
75 * all layers. All Socketless IP sends will soon be gone.
76 *
77 * On SMP we have one ICMP socket per-cpu.
78 */
79static inline struct sock *icmpv6_sk(struct net *net)
80{
81 return net->ipv6.icmp_sk[smp_processor_id()];
82}
83
84static int icmpv6_rcv(struct sk_buff *skb);
85
86static const struct inet6_protocol icmpv6_protocol = {
87 .handler = icmpv6_rcv,
88 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
89};
90
91static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
92{
93 struct sock *sk;
94
95 local_bh_disable();
96
97 sk = icmpv6_sk(net);
98 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
99 /* This can happen if the output path (f.e. SIT or
100 * ip6ip6 tunnel) signals dst_link_failure() for an
101 * outgoing ICMP6 packet.
102 */
103 local_bh_enable();
104 return NULL;
105 }
106 return sk;
107}
108
109static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
110{
111 spin_unlock_bh(&sk->sk_lock.slock);
112}
113
114/*
115 * Slightly more convenient version of icmpv6_send.
116 */
117void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
118{
119 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
120 kfree_skb(skb);
121}
122
123/*
124 * Figure out, may we reply to this packet with icmp error.
125 *
126 * We do not reply, if:
127 * - it was icmp error message.
128 * - it is truncated, so that it is known, that protocol is ICMPV6
129 * (i.e. in the middle of some exthdr)
130 *
131 * --ANK (980726)
132 */
133
134static bool is_ineligible(const struct sk_buff *skb)
135{
136 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
137 int len = skb->len - ptr;
138 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
139 __be16 frag_off;
140
141 if (len < 0)
142 return true;
143
144 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
145 if (ptr < 0)
146 return false;
147 if (nexthdr == IPPROTO_ICMPV6) {
148 u8 _type, *tp;
149 tp = skb_header_pointer(skb,
150 ptr+offsetof(struct icmp6hdr, icmp6_type),
151 sizeof(_type), &_type);
152 if (tp == NULL ||
153 !(*tp & ICMPV6_INFOMSG_MASK))
154 return true;
155 }
156 return false;
157}
158
159/*
160 * Check the ICMP output rate limit
161 */
162static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
163 struct flowi6 *fl6)
164{
165 struct dst_entry *dst;
166 struct net *net = sock_net(sk);
167 bool res = false;
168
169 /* Informational messages are not limited. */
170 if (type & ICMPV6_INFOMSG_MASK)
171 return true;
172
173 /* Do not limit pmtu discovery, it would break it. */
174 if (type == ICMPV6_PKT_TOOBIG)
175 return true;
176
177 /*
178 * Look up the output route.
179 * XXX: perhaps the expire for routing entries cloned by
180 * this lookup should be more aggressive (not longer than timeout).
181 */
182 dst = ip6_route_output(net, sk, fl6);
183 if (dst->error) {
184 IP6_INC_STATS(net, ip6_dst_idev(dst),
185 IPSTATS_MIB_OUTNOROUTES);
186 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
187 res = true;
188 } else {
189 struct rt6_info *rt = (struct rt6_info *)dst;
190 int tmo = net->ipv6.sysctl.icmpv6_time;
191
192 /* Give more bandwidth to wider prefixes. */
193 if (rt->rt6i_dst.plen < 128)
194 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
195
196 if (!rt->rt6i_peer)
197 rt6_bind_peer(rt, 1);
198 res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo);
199 }
200 dst_release(dst);
201 return res;
202}
203
204/*
205 * an inline helper for the "simple" if statement below
206 * checks if parameter problem report is caused by an
207 * unrecognized IPv6 option that has the Option Type
208 * highest-order two bits set to 10
209 */
210
211static bool opt_unrec(struct sk_buff *skb, __u32 offset)
212{
213 u8 _optval, *op;
214
215 offset += skb_network_offset(skb);
216 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
217 if (op == NULL)
218 return true;
219 return (*op & 0xC0) == 0x80;
220}
221
222static int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, struct icmp6hdr *thdr, int len)
223{
224 struct sk_buff *skb;
225 struct icmp6hdr *icmp6h;
226 int err = 0;
227
228 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
229 goto out;
230
231 icmp6h = icmp6_hdr(skb);
232 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
233 icmp6h->icmp6_cksum = 0;
234
235 if (skb_queue_len(&sk->sk_write_queue) == 1) {
236 skb->csum = csum_partial(icmp6h,
237 sizeof(struct icmp6hdr), skb->csum);
238 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
239 &fl6->daddr,
240 len, fl6->flowi6_proto,
241 skb->csum);
242 } else {
243 __wsum tmp_csum = 0;
244
245 skb_queue_walk(&sk->sk_write_queue, skb) {
246 tmp_csum = csum_add(tmp_csum, skb->csum);
247 }
248
249 tmp_csum = csum_partial(icmp6h,
250 sizeof(struct icmp6hdr), tmp_csum);
251 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
252 &fl6->daddr,
253 len, fl6->flowi6_proto,
254 tmp_csum);
255 }
256 ip6_push_pending_frames(sk);
257out:
258 return err;
259}
260
261struct icmpv6_msg {
262 struct sk_buff *skb;
263 int offset;
264 uint8_t type;
265};
266
267static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
268{
269 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
270 struct sk_buff *org_skb = msg->skb;
271 __wsum csum = 0;
272
273 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
274 to, len, csum);
275 skb->csum = csum_block_add(skb->csum, csum, odd);
276 if (!(msg->type & ICMPV6_INFOMSG_MASK))
277 nf_ct_attach(skb, org_skb);
278 return 0;
279}
280
281#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
282static void mip6_addr_swap(struct sk_buff *skb)
283{
284 struct ipv6hdr *iph = ipv6_hdr(skb);
285 struct inet6_skb_parm *opt = IP6CB(skb);
286 struct ipv6_destopt_hao *hao;
287 struct in6_addr tmp;
288 int off;
289
290 if (opt->dsthao) {
291 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
292 if (likely(off >= 0)) {
293 hao = (struct ipv6_destopt_hao *)
294 (skb_network_header(skb) + off);
295 tmp = iph->saddr;
296 iph->saddr = hao->addr;
297 hao->addr = tmp;
298 }
299 }
300}
301#else
302static inline void mip6_addr_swap(struct sk_buff *skb) {}
303#endif
304
305static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
306 struct sock *sk, struct flowi6 *fl6)
307{
308 struct dst_entry *dst, *dst2;
309 struct flowi6 fl2;
310 int err;
311
312 err = ip6_dst_lookup(sk, &dst, fl6);
313 if (err)
314 return ERR_PTR(err);
315
316 /*
317 * We won't send icmp if the destination is known
318 * anycast.
319 */
320 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) {
321 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n");
322 dst_release(dst);
323 return ERR_PTR(-EINVAL);
324 }
325
326 /* No need to clone since we're just using its address. */
327 dst2 = dst;
328
329 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
330 if (!IS_ERR(dst)) {
331 if (dst != dst2)
332 return dst;
333 } else {
334 if (PTR_ERR(dst) == -EPERM)
335 dst = NULL;
336 else
337 return dst;
338 }
339
340 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
341 if (err)
342 goto relookup_failed;
343
344 err = ip6_dst_lookup(sk, &dst2, &fl2);
345 if (err)
346 goto relookup_failed;
347
348 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
349 if (!IS_ERR(dst2)) {
350 dst_release(dst);
351 dst = dst2;
352 } else {
353 err = PTR_ERR(dst2);
354 if (err == -EPERM) {
355 dst_release(dst);
356 return dst2;
357 } else
358 goto relookup_failed;
359 }
360
361relookup_failed:
362 if (dst)
363 return dst;
364 return ERR_PTR(err);
365}
366
367/*
368 * Send an ICMP message in response to a packet in error
369 */
370void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
371{
372 struct net *net = dev_net(skb->dev);
373 struct inet6_dev *idev = NULL;
374 struct ipv6hdr *hdr = ipv6_hdr(skb);
375 struct sock *sk;
376 struct ipv6_pinfo *np;
377 const struct in6_addr *saddr = NULL;
378 struct dst_entry *dst;
379 struct icmp6hdr tmp_hdr;
380 struct flowi6 fl6;
381 struct icmpv6_msg msg;
382 int iif = 0;
383 int addr_type = 0;
384 int len;
385 int hlimit;
386 int err = 0;
387
388 if ((u8 *)hdr < skb->head ||
389 (skb->network_header + sizeof(*hdr)) > skb->tail)
390 return;
391
392 /*
393 * Make sure we respect the rules
394 * i.e. RFC 1885 2.4(e)
395 * Rule (e.1) is enforced by not using icmpv6_send
396 * in any code that processes icmp errors.
397 */
398 addr_type = ipv6_addr_type(&hdr->daddr);
399
400 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0))
401 saddr = &hdr->daddr;
402
403 /*
404 * Dest addr check
405 */
406
407 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) {
408 if (type != ICMPV6_PKT_TOOBIG &&
409 !(type == ICMPV6_PARAMPROB &&
410 code == ICMPV6_UNK_OPTION &&
411 (opt_unrec(skb, info))))
412 return;
413
414 saddr = NULL;
415 }
416
417 addr_type = ipv6_addr_type(&hdr->saddr);
418
419 /*
420 * Source addr check
421 */
422
423 if (addr_type & IPV6_ADDR_LINKLOCAL)
424 iif = skb->dev->ifindex;
425
426 /*
427 * Must not send error if the source does not uniquely
428 * identify a single node (RFC2463 Section 2.4).
429 * We check unspecified / multicast addresses here,
430 * and anycast addresses will be checked later.
431 */
432 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
433 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n");
434 return;
435 }
436
437 /*
438 * Never answer to a ICMP packet.
439 */
440 if (is_ineligible(skb)) {
441 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n");
442 return;
443 }
444
445 mip6_addr_swap(skb);
446
447 memset(&fl6, 0, sizeof(fl6));
448 fl6.flowi6_proto = IPPROTO_ICMPV6;
449 fl6.daddr = hdr->saddr;
450 if (saddr)
451 fl6.saddr = *saddr;
452 fl6.flowi6_oif = iif;
453 fl6.fl6_icmp_type = type;
454 fl6.fl6_icmp_code = code;
455 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
456
457 sk = icmpv6_xmit_lock(net);
458 if (sk == NULL)
459 return;
460 np = inet6_sk(sk);
461
462 if (!icmpv6_xrlim_allow(sk, type, &fl6))
463 goto out;
464
465 tmp_hdr.icmp6_type = type;
466 tmp_hdr.icmp6_code = code;
467 tmp_hdr.icmp6_cksum = 0;
468 tmp_hdr.icmp6_pointer = htonl(info);
469
470 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
471 fl6.flowi6_oif = np->mcast_oif;
472 else if (!fl6.flowi6_oif)
473 fl6.flowi6_oif = np->ucast_oif;
474
475 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
476 if (IS_ERR(dst))
477 goto out;
478
479 if (ipv6_addr_is_multicast(&fl6.daddr))
480 hlimit = np->mcast_hops;
481 else
482 hlimit = np->hop_limit;
483 if (hlimit < 0)
484 hlimit = ip6_dst_hoplimit(dst);
485
486 msg.skb = skb;
487 msg.offset = skb_network_offset(skb);
488 msg.type = type;
489
490 len = skb->len - msg.offset;
491 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
492 if (len < 0) {
493 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n");
494 goto out_dst_release;
495 }
496
497 rcu_read_lock();
498 idev = __in6_dev_get(skb->dev);
499
500 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
501 len + sizeof(struct icmp6hdr),
502 sizeof(struct icmp6hdr), hlimit,
503 np->tclass, NULL, &fl6, (struct rt6_info *)dst,
504 MSG_DONTWAIT, np->dontfrag);
505 if (err) {
506 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
507 ip6_flush_pending_frames(sk);
508 } else {
509 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
510 len + sizeof(struct icmp6hdr));
511 }
512 rcu_read_unlock();
513out_dst_release:
514 dst_release(dst);
515out:
516 icmpv6_xmit_unlock(sk);
517}
518EXPORT_SYMBOL(icmpv6_send);
519
520static void icmpv6_echo_reply(struct sk_buff *skb)
521{
522 struct net *net = dev_net(skb->dev);
523 struct sock *sk;
524 struct inet6_dev *idev;
525 struct ipv6_pinfo *np;
526 const struct in6_addr *saddr = NULL;
527 struct icmp6hdr *icmph = icmp6_hdr(skb);
528 struct icmp6hdr tmp_hdr;
529 struct flowi6 fl6;
530 struct icmpv6_msg msg;
531 struct dst_entry *dst;
532 int err = 0;
533 int hlimit;
534
535 saddr = &ipv6_hdr(skb)->daddr;
536
537 if (!ipv6_unicast_destination(skb))
538 saddr = NULL;
539
540 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
541 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
542
543 memset(&fl6, 0, sizeof(fl6));
544 fl6.flowi6_proto = IPPROTO_ICMPV6;
545 fl6.daddr = ipv6_hdr(skb)->saddr;
546 if (saddr)
547 fl6.saddr = *saddr;
548 fl6.flowi6_oif = skb->dev->ifindex;
549 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
550 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
551
552 sk = icmpv6_xmit_lock(net);
553 if (sk == NULL)
554 return;
555 np = inet6_sk(sk);
556
557 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
558 fl6.flowi6_oif = np->mcast_oif;
559 else if (!fl6.flowi6_oif)
560 fl6.flowi6_oif = np->ucast_oif;
561
562 err = ip6_dst_lookup(sk, &dst, &fl6);
563 if (err)
564 goto out;
565 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
566 if (IS_ERR(dst))
567 goto out;
568
569 if (ipv6_addr_is_multicast(&fl6.daddr))
570 hlimit = np->mcast_hops;
571 else
572 hlimit = np->hop_limit;
573 if (hlimit < 0)
574 hlimit = ip6_dst_hoplimit(dst);
575
576 idev = __in6_dev_get(skb->dev);
577
578 msg.skb = skb;
579 msg.offset = 0;
580 msg.type = ICMPV6_ECHO_REPLY;
581
582 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
583 sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6,
584 (struct rt6_info *)dst, MSG_DONTWAIT,
585 np->dontfrag);
586
587 if (err) {
588 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
589 ip6_flush_pending_frames(sk);
590 } else {
591 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
592 skb->len + sizeof(struct icmp6hdr));
593 }
594 dst_release(dst);
595out:
596 icmpv6_xmit_unlock(sk);
597}
598
599static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
600{
601 const struct inet6_protocol *ipprot;
602 int inner_offset;
603 int hash;
604 u8 nexthdr;
605 __be16 frag_off;
606
607 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
608 return;
609
610 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
611 if (ipv6_ext_hdr(nexthdr)) {
612 /* now skip over extension headers */
613 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
614 &nexthdr, &frag_off);
615 if (inner_offset<0)
616 return;
617 } else {
618 inner_offset = sizeof(struct ipv6hdr);
619 }
620
621 /* Checkin header including 8 bytes of inner protocol header. */
622 if (!pskb_may_pull(skb, inner_offset+8))
623 return;
624
625 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
626 Without this we will not able f.e. to make source routed
627 pmtu discovery.
628 Corresponding argument (opt) to notifiers is already added.
629 --ANK (980726)
630 */
631
632 hash = nexthdr & (MAX_INET_PROTOS - 1);
633
634 rcu_read_lock();
635 ipprot = rcu_dereference(inet6_protos[hash]);
636 if (ipprot && ipprot->err_handler)
637 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
638 rcu_read_unlock();
639
640 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
641}
642
643/*
644 * Handle icmp messages
645 */
646
647static int icmpv6_rcv(struct sk_buff *skb)
648{
649 struct net_device *dev = skb->dev;
650 struct inet6_dev *idev = __in6_dev_get(dev);
651 const struct in6_addr *saddr, *daddr;
652 const struct ipv6hdr *orig_hdr;
653 struct icmp6hdr *hdr;
654 u8 type;
655
656 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
657 struct sec_path *sp = skb_sec_path(skb);
658 int nh;
659
660 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
661 XFRM_STATE_ICMP))
662 goto drop_no_count;
663
664 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr)))
665 goto drop_no_count;
666
667 nh = skb_network_offset(skb);
668 skb_set_network_header(skb, sizeof(*hdr));
669
670 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
671 goto drop_no_count;
672
673 skb_set_network_header(skb, nh);
674 }
675
676 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
677
678 saddr = &ipv6_hdr(skb)->saddr;
679 daddr = &ipv6_hdr(skb)->daddr;
680
681 /* Perform checksum. */
682 switch (skb->ip_summed) {
683 case CHECKSUM_COMPLETE:
684 if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
685 skb->csum))
686 break;
687 /* fall through */
688 case CHECKSUM_NONE:
689 skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len,
690 IPPROTO_ICMPV6, 0));
691 if (__skb_checksum_complete(skb)) {
692 LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n",
693 saddr, daddr);
694 goto discard_it;
695 }
696 }
697
698 if (!pskb_pull(skb, sizeof(*hdr)))
699 goto discard_it;
700
701 hdr = icmp6_hdr(skb);
702
703 type = hdr->icmp6_type;
704
705 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
706
707 switch (type) {
708 case ICMPV6_ECHO_REQUEST:
709 icmpv6_echo_reply(skb);
710 break;
711
712 case ICMPV6_ECHO_REPLY:
713 /* we couldn't care less */
714 break;
715
716 case ICMPV6_PKT_TOOBIG:
717 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
718 standard destination cache. Seems, only "advanced"
719 destination cache will allow to solve this problem
720 --ANK (980726)
721 */
722 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
723 goto discard_it;
724 hdr = icmp6_hdr(skb);
725 orig_hdr = (struct ipv6hdr *) (hdr + 1);
726 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev,
727 ntohl(hdr->icmp6_mtu));
728
729 /*
730 * Drop through to notify
731 */
732
733 case ICMPV6_DEST_UNREACH:
734 case ICMPV6_TIME_EXCEED:
735 case ICMPV6_PARAMPROB:
736 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
737 break;
738
739 case NDISC_ROUTER_SOLICITATION:
740 case NDISC_ROUTER_ADVERTISEMENT:
741 case NDISC_NEIGHBOUR_SOLICITATION:
742 case NDISC_NEIGHBOUR_ADVERTISEMENT:
743 case NDISC_REDIRECT:
744 ndisc_rcv(skb);
745 break;
746
747 case ICMPV6_MGM_QUERY:
748 igmp6_event_query(skb);
749 break;
750
751 case ICMPV6_MGM_REPORT:
752 igmp6_event_report(skb);
753 break;
754
755 case ICMPV6_MGM_REDUCTION:
756 case ICMPV6_NI_QUERY:
757 case ICMPV6_NI_REPLY:
758 case ICMPV6_MLD2_REPORT:
759 case ICMPV6_DHAAD_REQUEST:
760 case ICMPV6_DHAAD_REPLY:
761 case ICMPV6_MOBILE_PREFIX_SOL:
762 case ICMPV6_MOBILE_PREFIX_ADV:
763 break;
764
765 default:
766 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n");
767
768 /* informational */
769 if (type & ICMPV6_INFOMSG_MASK)
770 break;
771
772 /*
773 * error of unknown type.
774 * must pass to upper level
775 */
776
777 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
778 }
779
780 kfree_skb(skb);
781 return 0;
782
783discard_it:
784 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
785drop_no_count:
786 kfree_skb(skb);
787 return 0;
788}
789
790void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
791 u8 type,
792 const struct in6_addr *saddr,
793 const struct in6_addr *daddr,
794 int oif)
795{
796 memset(fl6, 0, sizeof(*fl6));
797 fl6->saddr = *saddr;
798 fl6->daddr = *daddr;
799 fl6->flowi6_proto = IPPROTO_ICMPV6;
800 fl6->fl6_icmp_type = type;
801 fl6->fl6_icmp_code = 0;
802 fl6->flowi6_oif = oif;
803 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
804}
805
806/*
807 * Special lock-class for __icmpv6_sk:
808 */
809static struct lock_class_key icmpv6_socket_sk_dst_lock_key;
810
811static int __net_init icmpv6_sk_init(struct net *net)
812{
813 struct sock *sk;
814 int err, i, j;
815
816 net->ipv6.icmp_sk =
817 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
818 if (net->ipv6.icmp_sk == NULL)
819 return -ENOMEM;
820
821 for_each_possible_cpu(i) {
822 err = inet_ctl_sock_create(&sk, PF_INET6,
823 SOCK_RAW, IPPROTO_ICMPV6, net);
824 if (err < 0) {
825 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
826 err);
827 goto fail;
828 }
829
830 net->ipv6.icmp_sk[i] = sk;
831
832 /*
833 * Split off their lock-class, because sk->sk_dst_lock
834 * gets used from softirqs, which is safe for
835 * __icmpv6_sk (because those never get directly used
836 * via userspace syscalls), but unsafe for normal sockets.
837 */
838 lockdep_set_class(&sk->sk_dst_lock,
839 &icmpv6_socket_sk_dst_lock_key);
840
841 /* Enough space for 2 64K ICMP packets, including
842 * sk_buff struct overhead.
843 */
844 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
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 pr_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}
953EXPORT_SYMBOL(icmpv6_err_convert);
954
955#ifdef CONFIG_SYSCTL
956ctl_table ipv6_icmp_table_template[] = {
957 {
958 .procname = "ratelimit",
959 .data = &init_net.ipv6.sysctl.icmpv6_time,
960 .maxlen = sizeof(int),
961 .mode = 0644,
962 .proc_handler = proc_dointvec_ms_jiffies,
963 },
964 { },
965};
966
967struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
968{
969 struct ctl_table *table;
970
971 table = kmemdup(ipv6_icmp_table_template,
972 sizeof(ipv6_icmp_table_template),
973 GFP_KERNEL);
974
975 if (table)
976 table[0].data = &net->ipv6.sysctl.icmpv6_time;
977
978 return table;
979}
980#endif
981