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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 <linux/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, sock_net_uid(net, NULL));
96 else if (type == NDISC_REDIRECT)
97 ip6_redirect(skb, net, skb->dev->ifindex, 0,
98 sock_net_uid(net, NULL));
99
100 if (!(type & ICMPV6_INFOMSG_MASK))
101 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
102 ping_err(skb, offset, ntohl(info));
103}
104
105static int icmpv6_rcv(struct sk_buff *skb);
106
107static const struct inet6_protocol icmpv6_protocol = {
108 .handler = icmpv6_rcv,
109 .err_handler = icmpv6_err,
110 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
111};
112
113/* Called with BH disabled */
114static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
115{
116 struct sock *sk;
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 return NULL;
125 }
126 return sk;
127}
128
129static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
130{
131 spin_unlock(&sk->sk_lock.slock);
132}
133
134/*
135 * Figure out, may we reply to this packet with icmp error.
136 *
137 * We do not reply, if:
138 * - it was icmp error message.
139 * - it is truncated, so that it is known, that protocol is ICMPV6
140 * (i.e. in the middle of some exthdr)
141 *
142 * --ANK (980726)
143 */
144
145static bool is_ineligible(const struct sk_buff *skb)
146{
147 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
148 int len = skb->len - ptr;
149 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
150 __be16 frag_off;
151
152 if (len < 0)
153 return true;
154
155 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
156 if (ptr < 0)
157 return false;
158 if (nexthdr == IPPROTO_ICMPV6) {
159 u8 _type, *tp;
160 tp = skb_header_pointer(skb,
161 ptr+offsetof(struct icmp6hdr, icmp6_type),
162 sizeof(_type), &_type);
163 if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
164 return true;
165 }
166 return false;
167}
168
169static bool icmpv6_mask_allow(int type)
170{
171 /* Informational messages are not limited. */
172 if (type & ICMPV6_INFOMSG_MASK)
173 return true;
174
175 /* Do not limit pmtu discovery, it would break it. */
176 if (type == ICMPV6_PKT_TOOBIG)
177 return true;
178
179 return false;
180}
181
182static bool icmpv6_global_allow(int type)
183{
184 if (icmpv6_mask_allow(type))
185 return true;
186
187 if (icmp_global_allow())
188 return true;
189
190 return false;
191}
192
193/*
194 * Check the ICMP output rate limit
195 */
196static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
197 struct flowi6 *fl6)
198{
199 struct net *net = sock_net(sk);
200 struct dst_entry *dst;
201 bool res = false;
202
203 if (icmpv6_mask_allow(type))
204 return true;
205
206 /*
207 * Look up the output route.
208 * XXX: perhaps the expire for routing entries cloned by
209 * this lookup should be more aggressive (not longer than timeout).
210 */
211 dst = ip6_route_output(net, sk, fl6);
212 if (dst->error) {
213 IP6_INC_STATS(net, ip6_dst_idev(dst),
214 IPSTATS_MIB_OUTNOROUTES);
215 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
216 res = true;
217 } else {
218 struct rt6_info *rt = (struct rt6_info *)dst;
219 int tmo = net->ipv6.sysctl.icmpv6_time;
220 struct inet_peer *peer;
221
222 /* Give more bandwidth to wider prefixes. */
223 if (rt->rt6i_dst.plen < 128)
224 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
225
226 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
227 res = inet_peer_xrlim_allow(peer, tmo);
228 if (peer)
229 inet_putpeer(peer);
230 }
231 dst_release(dst);
232 return res;
233}
234
235/*
236 * an inline helper for the "simple" if statement below
237 * checks if parameter problem report is caused by an
238 * unrecognized IPv6 option that has the Option Type
239 * highest-order two bits set to 10
240 */
241
242static bool opt_unrec(struct sk_buff *skb, __u32 offset)
243{
244 u8 _optval, *op;
245
246 offset += skb_network_offset(skb);
247 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
248 if (!op)
249 return true;
250 return (*op & 0xC0) == 0x80;
251}
252
253void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
254 struct icmp6hdr *thdr, int len)
255{
256 struct sk_buff *skb;
257 struct icmp6hdr *icmp6h;
258
259 skb = skb_peek(&sk->sk_write_queue);
260 if (!skb)
261 return;
262
263 icmp6h = icmp6_hdr(skb);
264 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
265 icmp6h->icmp6_cksum = 0;
266
267 if (skb_queue_len(&sk->sk_write_queue) == 1) {
268 skb->csum = csum_partial(icmp6h,
269 sizeof(struct icmp6hdr), skb->csum);
270 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
271 &fl6->daddr,
272 len, fl6->flowi6_proto,
273 skb->csum);
274 } else {
275 __wsum tmp_csum = 0;
276
277 skb_queue_walk(&sk->sk_write_queue, skb) {
278 tmp_csum = csum_add(tmp_csum, skb->csum);
279 }
280
281 tmp_csum = csum_partial(icmp6h,
282 sizeof(struct icmp6hdr), tmp_csum);
283 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
284 &fl6->daddr,
285 len, fl6->flowi6_proto,
286 tmp_csum);
287 }
288 ip6_push_pending_frames(sk);
289}
290
291struct icmpv6_msg {
292 struct sk_buff *skb;
293 int offset;
294 uint8_t type;
295};
296
297static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
298{
299 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
300 struct sk_buff *org_skb = msg->skb;
301 __wsum csum = 0;
302
303 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
304 to, len, csum);
305 skb->csum = csum_block_add(skb->csum, csum, odd);
306 if (!(msg->type & ICMPV6_INFOMSG_MASK))
307 nf_ct_attach(skb, org_skb);
308 return 0;
309}
310
311#if IS_ENABLED(CONFIG_IPV6_MIP6)
312static void mip6_addr_swap(struct sk_buff *skb)
313{
314 struct ipv6hdr *iph = ipv6_hdr(skb);
315 struct inet6_skb_parm *opt = IP6CB(skb);
316 struct ipv6_destopt_hao *hao;
317 struct in6_addr tmp;
318 int off;
319
320 if (opt->dsthao) {
321 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
322 if (likely(off >= 0)) {
323 hao = (struct ipv6_destopt_hao *)
324 (skb_network_header(skb) + off);
325 tmp = iph->saddr;
326 iph->saddr = hao->addr;
327 hao->addr = tmp;
328 }
329 }
330}
331#else
332static inline void mip6_addr_swap(struct sk_buff *skb) {}
333#endif
334
335static struct dst_entry *icmpv6_route_lookup(struct net *net,
336 struct sk_buff *skb,
337 struct sock *sk,
338 struct flowi6 *fl6)
339{
340 struct dst_entry *dst, *dst2;
341 struct flowi6 fl2;
342 int err;
343
344 err = ip6_dst_lookup(net, sk, &dst, fl6);
345 if (err)
346 return ERR_PTR(err);
347
348 /*
349 * We won't send icmp if the destination is known
350 * anycast.
351 */
352 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
353 net_dbg_ratelimited("icmp6_send: acast source\n");
354 dst_release(dst);
355 return ERR_PTR(-EINVAL);
356 }
357
358 /* No need to clone since we're just using its address. */
359 dst2 = dst;
360
361 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
362 if (!IS_ERR(dst)) {
363 if (dst != dst2)
364 return dst;
365 } else {
366 if (PTR_ERR(dst) == -EPERM)
367 dst = NULL;
368 else
369 return dst;
370 }
371
372 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
373 if (err)
374 goto relookup_failed;
375
376 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
377 if (err)
378 goto relookup_failed;
379
380 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
381 if (!IS_ERR(dst2)) {
382 dst_release(dst);
383 dst = dst2;
384 } else {
385 err = PTR_ERR(dst2);
386 if (err == -EPERM) {
387 dst_release(dst);
388 return dst2;
389 } else
390 goto relookup_failed;
391 }
392
393relookup_failed:
394 if (dst)
395 return dst;
396 return ERR_PTR(err);
397}
398
399static int icmp6_iif(const struct sk_buff *skb)
400{
401 int iif = skb->dev->ifindex;
402
403 /* for local traffic to local address, skb dev is the loopback
404 * device. Check if there is a dst attached to the skb and if so
405 * get the real device index.
406 */
407 if (unlikely(iif == LOOPBACK_IFINDEX)) {
408 const struct rt6_info *rt6 = skb_rt6_info(skb);
409
410 if (rt6)
411 iif = rt6->rt6i_idev->dev->ifindex;
412 }
413
414 return iif;
415}
416
417/*
418 * Send an ICMP message in response to a packet in error
419 */
420static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
421 const struct in6_addr *force_saddr)
422{
423 struct net *net = dev_net(skb->dev);
424 struct inet6_dev *idev = NULL;
425 struct ipv6hdr *hdr = ipv6_hdr(skb);
426 struct sock *sk;
427 struct ipv6_pinfo *np;
428 const struct in6_addr *saddr = NULL;
429 struct dst_entry *dst;
430 struct icmp6hdr tmp_hdr;
431 struct flowi6 fl6;
432 struct icmpv6_msg msg;
433 struct sockcm_cookie sockc_unused = {0};
434 struct ipcm6_cookie ipc6;
435 int iif = 0;
436 int addr_type = 0;
437 int len;
438 u32 mark = IP6_REPLY_MARK(net, skb->mark);
439
440 if ((u8 *)hdr < skb->head ||
441 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
442 return;
443
444 /*
445 * Make sure we respect the rules
446 * i.e. RFC 1885 2.4(e)
447 * Rule (e.1) is enforced by not using icmp6_send
448 * in any code that processes icmp errors.
449 */
450 addr_type = ipv6_addr_type(&hdr->daddr);
451
452 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
453 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
454 saddr = &hdr->daddr;
455
456 /*
457 * Dest addr check
458 */
459
460 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
461 if (type != ICMPV6_PKT_TOOBIG &&
462 !(type == ICMPV6_PARAMPROB &&
463 code == ICMPV6_UNK_OPTION &&
464 (opt_unrec(skb, info))))
465 return;
466
467 saddr = NULL;
468 }
469
470 addr_type = ipv6_addr_type(&hdr->saddr);
471
472 /*
473 * Source addr check
474 */
475
476 if (__ipv6_addr_needs_scope_id(addr_type)) {
477 iif = icmp6_iif(skb);
478 } else {
479 dst = skb_dst(skb);
480 iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
481 }
482
483 /*
484 * Must not send error if the source does not uniquely
485 * identify a single node (RFC2463 Section 2.4).
486 * We check unspecified / multicast addresses here,
487 * and anycast addresses will be checked later.
488 */
489 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
490 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
491 &hdr->saddr, &hdr->daddr);
492 return;
493 }
494
495 /*
496 * Never answer to a ICMP packet.
497 */
498 if (is_ineligible(skb)) {
499 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
500 &hdr->saddr, &hdr->daddr);
501 return;
502 }
503
504 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
505 local_bh_disable();
506
507 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
508 if (!(skb->dev->flags&IFF_LOOPBACK) && !icmpv6_global_allow(type))
509 goto out_bh_enable;
510
511 mip6_addr_swap(skb);
512
513 memset(&fl6, 0, sizeof(fl6));
514 fl6.flowi6_proto = IPPROTO_ICMPV6;
515 fl6.daddr = hdr->saddr;
516 if (force_saddr)
517 saddr = force_saddr;
518 if (saddr)
519 fl6.saddr = *saddr;
520 fl6.flowi6_mark = mark;
521 fl6.flowi6_oif = iif;
522 fl6.fl6_icmp_type = type;
523 fl6.fl6_icmp_code = code;
524 fl6.flowi6_uid = sock_net_uid(net, NULL);
525 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
526 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
527
528 sk = icmpv6_xmit_lock(net);
529 if (!sk)
530 goto out_bh_enable;
531
532 sk->sk_mark = mark;
533 np = inet6_sk(sk);
534
535 if (!icmpv6_xrlim_allow(sk, type, &fl6))
536 goto out;
537
538 tmp_hdr.icmp6_type = type;
539 tmp_hdr.icmp6_code = code;
540 tmp_hdr.icmp6_cksum = 0;
541 tmp_hdr.icmp6_pointer = htonl(info);
542
543 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
544 fl6.flowi6_oif = np->mcast_oif;
545 else if (!fl6.flowi6_oif)
546 fl6.flowi6_oif = np->ucast_oif;
547
548 ipc6.tclass = np->tclass;
549 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
550
551 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
552 if (IS_ERR(dst))
553 goto out;
554
555 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
556 ipc6.dontfrag = np->dontfrag;
557 ipc6.opt = NULL;
558
559 msg.skb = skb;
560 msg.offset = skb_network_offset(skb);
561 msg.type = type;
562
563 len = skb->len - msg.offset;
564 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
565 if (len < 0) {
566 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
567 &hdr->saddr, &hdr->daddr);
568 goto out_dst_release;
569 }
570
571 rcu_read_lock();
572 idev = __in6_dev_get(skb->dev);
573
574 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
575 len + sizeof(struct icmp6hdr),
576 sizeof(struct icmp6hdr),
577 &ipc6, &fl6, (struct rt6_info *)dst,
578 MSG_DONTWAIT, &sockc_unused)) {
579 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
580 ip6_flush_pending_frames(sk);
581 } else {
582 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
583 len + sizeof(struct icmp6hdr));
584 }
585 rcu_read_unlock();
586out_dst_release:
587 dst_release(dst);
588out:
589 icmpv6_xmit_unlock(sk);
590out_bh_enable:
591 local_bh_enable();
592}
593
594/* Slightly more convenient version of icmp6_send.
595 */
596void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
597{
598 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
599 kfree_skb(skb);
600}
601
602/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
603 * if sufficient data bytes are available
604 * @nhs is the size of the tunnel header(s) :
605 * Either an IPv4 header for SIT encap
606 * an IPv4 header + GRE header for GRE encap
607 */
608int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
609 unsigned int data_len)
610{
611 struct in6_addr temp_saddr;
612 struct rt6_info *rt;
613 struct sk_buff *skb2;
614 u32 info = 0;
615
616 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
617 return 1;
618
619 /* RFC 4884 (partial) support for ICMP extensions */
620 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
621 data_len = 0;
622
623 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
624
625 if (!skb2)
626 return 1;
627
628 skb_dst_drop(skb2);
629 skb_pull(skb2, nhs);
630 skb_reset_network_header(skb2);
631
632 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
633 skb, 0);
634
635 if (rt && rt->dst.dev)
636 skb2->dev = rt->dst.dev;
637
638 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
639
640 if (data_len) {
641 /* RFC 4884 (partial) support :
642 * insert 0 padding at the end, before the extensions
643 */
644 __skb_push(skb2, nhs);
645 skb_reset_network_header(skb2);
646 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
647 memset(skb2->data + data_len - nhs, 0, nhs);
648 /* RFC 4884 4.5 : Length is measured in 64-bit words,
649 * and stored in reserved[0]
650 */
651 info = (data_len/8) << 24;
652 }
653 if (type == ICMP_TIME_EXCEEDED)
654 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
655 info, &temp_saddr);
656 else
657 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
658 info, &temp_saddr);
659 if (rt)
660 ip6_rt_put(rt);
661
662 kfree_skb(skb2);
663
664 return 0;
665}
666EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
667
668static void icmpv6_echo_reply(struct sk_buff *skb)
669{
670 struct net *net = dev_net(skb->dev);
671 struct sock *sk;
672 struct inet6_dev *idev;
673 struct ipv6_pinfo *np;
674 const struct in6_addr *saddr = NULL;
675 struct icmp6hdr *icmph = icmp6_hdr(skb);
676 struct icmp6hdr tmp_hdr;
677 struct flowi6 fl6;
678 struct icmpv6_msg msg;
679 struct dst_entry *dst;
680 struct ipcm6_cookie ipc6;
681 u32 mark = IP6_REPLY_MARK(net, skb->mark);
682 struct sockcm_cookie sockc_unused = {0};
683
684 saddr = &ipv6_hdr(skb)->daddr;
685
686 if (!ipv6_unicast_destination(skb) &&
687 !(net->ipv6.sysctl.anycast_src_echo_reply &&
688 ipv6_anycast_destination(skb_dst(skb), saddr)))
689 saddr = NULL;
690
691 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
692 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
693
694 memset(&fl6, 0, sizeof(fl6));
695 fl6.flowi6_proto = IPPROTO_ICMPV6;
696 fl6.daddr = ipv6_hdr(skb)->saddr;
697 if (saddr)
698 fl6.saddr = *saddr;
699 fl6.flowi6_oif = icmp6_iif(skb);
700 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
701 fl6.flowi6_mark = mark;
702 fl6.flowi6_uid = sock_net_uid(net, NULL);
703 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
704
705 local_bh_disable();
706 sk = icmpv6_xmit_lock(net);
707 if (!sk)
708 goto out_bh_enable;
709 sk->sk_mark = mark;
710 np = inet6_sk(sk);
711
712 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
713 fl6.flowi6_oif = np->mcast_oif;
714 else if (!fl6.flowi6_oif)
715 fl6.flowi6_oif = np->ucast_oif;
716
717 if (ip6_dst_lookup(net, sk, &dst, &fl6))
718 goto out;
719 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
720 if (IS_ERR(dst))
721 goto out;
722
723 idev = __in6_dev_get(skb->dev);
724
725 msg.skb = skb;
726 msg.offset = 0;
727 msg.type = ICMPV6_ECHO_REPLY;
728
729 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
730 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
731 ipc6.dontfrag = np->dontfrag;
732 ipc6.opt = NULL;
733
734 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
735 skb->len + sizeof(struct icmp6hdr),
736 sizeof(struct icmp6hdr), &ipc6, &fl6,
737 (struct rt6_info *)dst, MSG_DONTWAIT,
738 &sockc_unused)) {
739 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
740 ip6_flush_pending_frames(sk);
741 } else {
742 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
743 skb->len + sizeof(struct icmp6hdr));
744 }
745 dst_release(dst);
746out:
747 icmpv6_xmit_unlock(sk);
748out_bh_enable:
749 local_bh_enable();
750}
751
752void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
753{
754 const struct inet6_protocol *ipprot;
755 int inner_offset;
756 __be16 frag_off;
757 u8 nexthdr;
758 struct net *net = dev_net(skb->dev);
759
760 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
761 goto out;
762
763 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
764 if (ipv6_ext_hdr(nexthdr)) {
765 /* now skip over extension headers */
766 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
767 &nexthdr, &frag_off);
768 if (inner_offset < 0)
769 goto out;
770 } else {
771 inner_offset = sizeof(struct ipv6hdr);
772 }
773
774 /* Checkin header including 8 bytes of inner protocol header. */
775 if (!pskb_may_pull(skb, inner_offset+8))
776 goto out;
777
778 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
779 Without this we will not able f.e. to make source routed
780 pmtu discovery.
781 Corresponding argument (opt) to notifiers is already added.
782 --ANK (980726)
783 */
784
785 ipprot = rcu_dereference(inet6_protos[nexthdr]);
786 if (ipprot && ipprot->err_handler)
787 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
788
789 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
790 return;
791
792out:
793 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
794}
795
796/*
797 * Handle icmp messages
798 */
799
800static int icmpv6_rcv(struct sk_buff *skb)
801{
802 struct net_device *dev = skb->dev;
803 struct inet6_dev *idev = __in6_dev_get(dev);
804 const struct in6_addr *saddr, *daddr;
805 struct icmp6hdr *hdr;
806 u8 type;
807 bool success = false;
808
809 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
810 struct sec_path *sp = skb_sec_path(skb);
811 int nh;
812
813 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
814 XFRM_STATE_ICMP))
815 goto drop_no_count;
816
817 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
818 goto drop_no_count;
819
820 nh = skb_network_offset(skb);
821 skb_set_network_header(skb, sizeof(*hdr));
822
823 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
824 goto drop_no_count;
825
826 skb_set_network_header(skb, nh);
827 }
828
829 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
830
831 saddr = &ipv6_hdr(skb)->saddr;
832 daddr = &ipv6_hdr(skb)->daddr;
833
834 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
835 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
836 saddr, daddr);
837 goto csum_error;
838 }
839
840 if (!pskb_pull(skb, sizeof(*hdr)))
841 goto discard_it;
842
843 hdr = icmp6_hdr(skb);
844
845 type = hdr->icmp6_type;
846
847 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
848
849 switch (type) {
850 case ICMPV6_ECHO_REQUEST:
851 icmpv6_echo_reply(skb);
852 break;
853
854 case ICMPV6_ECHO_REPLY:
855 success = ping_rcv(skb);
856 break;
857
858 case ICMPV6_PKT_TOOBIG:
859 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
860 standard destination cache. Seems, only "advanced"
861 destination cache will allow to solve this problem
862 --ANK (980726)
863 */
864 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
865 goto discard_it;
866 hdr = icmp6_hdr(skb);
867
868 /* to notify */
869 /* fall through */
870 case ICMPV6_DEST_UNREACH:
871 case ICMPV6_TIME_EXCEED:
872 case ICMPV6_PARAMPROB:
873 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
874 break;
875
876 case NDISC_ROUTER_SOLICITATION:
877 case NDISC_ROUTER_ADVERTISEMENT:
878 case NDISC_NEIGHBOUR_SOLICITATION:
879 case NDISC_NEIGHBOUR_ADVERTISEMENT:
880 case NDISC_REDIRECT:
881 ndisc_rcv(skb);
882 break;
883
884 case ICMPV6_MGM_QUERY:
885 igmp6_event_query(skb);
886 break;
887
888 case ICMPV6_MGM_REPORT:
889 igmp6_event_report(skb);
890 break;
891
892 case ICMPV6_MGM_REDUCTION:
893 case ICMPV6_NI_QUERY:
894 case ICMPV6_NI_REPLY:
895 case ICMPV6_MLD2_REPORT:
896 case ICMPV6_DHAAD_REQUEST:
897 case ICMPV6_DHAAD_REPLY:
898 case ICMPV6_MOBILE_PREFIX_SOL:
899 case ICMPV6_MOBILE_PREFIX_ADV:
900 break;
901
902 default:
903 /* informational */
904 if (type & ICMPV6_INFOMSG_MASK)
905 break;
906
907 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
908 saddr, daddr);
909
910 /*
911 * error of unknown type.
912 * must pass to upper level
913 */
914
915 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
916 }
917
918 /* until the v6 path can be better sorted assume failure and
919 * preserve the status quo behaviour for the rest of the paths to here
920 */
921 if (success)
922 consume_skb(skb);
923 else
924 kfree_skb(skb);
925
926 return 0;
927
928csum_error:
929 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
930discard_it:
931 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
932drop_no_count:
933 kfree_skb(skb);
934 return 0;
935}
936
937void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
938 u8 type,
939 const struct in6_addr *saddr,
940 const struct in6_addr *daddr,
941 int oif)
942{
943 memset(fl6, 0, sizeof(*fl6));
944 fl6->saddr = *saddr;
945 fl6->daddr = *daddr;
946 fl6->flowi6_proto = IPPROTO_ICMPV6;
947 fl6->fl6_icmp_type = type;
948 fl6->fl6_icmp_code = 0;
949 fl6->flowi6_oif = oif;
950 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
951}
952
953static int __net_init icmpv6_sk_init(struct net *net)
954{
955 struct sock *sk;
956 int err, i, j;
957
958 net->ipv6.icmp_sk =
959 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
960 if (!net->ipv6.icmp_sk)
961 return -ENOMEM;
962
963 for_each_possible_cpu(i) {
964 err = inet_ctl_sock_create(&sk, PF_INET6,
965 SOCK_RAW, IPPROTO_ICMPV6, net);
966 if (err < 0) {
967 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
968 err);
969 goto fail;
970 }
971
972 net->ipv6.icmp_sk[i] = sk;
973
974 /* Enough space for 2 64K ICMP packets, including
975 * sk_buff struct overhead.
976 */
977 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
978 }
979 return 0;
980
981 fail:
982 for (j = 0; j < i; j++)
983 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
984 kfree(net->ipv6.icmp_sk);
985 return err;
986}
987
988static void __net_exit icmpv6_sk_exit(struct net *net)
989{
990 int i;
991
992 for_each_possible_cpu(i) {
993 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
994 }
995 kfree(net->ipv6.icmp_sk);
996}
997
998static struct pernet_operations icmpv6_sk_ops = {
999 .init = icmpv6_sk_init,
1000 .exit = icmpv6_sk_exit,
1001};
1002
1003int __init icmpv6_init(void)
1004{
1005 int err;
1006
1007 err = register_pernet_subsys(&icmpv6_sk_ops);
1008 if (err < 0)
1009 return err;
1010
1011 err = -EAGAIN;
1012 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1013 goto fail;
1014
1015 err = inet6_register_icmp_sender(icmp6_send);
1016 if (err)
1017 goto sender_reg_err;
1018 return 0;
1019
1020sender_reg_err:
1021 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1022fail:
1023 pr_err("Failed to register ICMP6 protocol\n");
1024 unregister_pernet_subsys(&icmpv6_sk_ops);
1025 return err;
1026}
1027
1028void icmpv6_cleanup(void)
1029{
1030 inet6_unregister_icmp_sender(icmp6_send);
1031 unregister_pernet_subsys(&icmpv6_sk_ops);
1032 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1033}
1034
1035
1036static const struct icmp6_err {
1037 int err;
1038 int fatal;
1039} tab_unreach[] = {
1040 { /* NOROUTE */
1041 .err = ENETUNREACH,
1042 .fatal = 0,
1043 },
1044 { /* ADM_PROHIBITED */
1045 .err = EACCES,
1046 .fatal = 1,
1047 },
1048 { /* Was NOT_NEIGHBOUR, now reserved */
1049 .err = EHOSTUNREACH,
1050 .fatal = 0,
1051 },
1052 { /* ADDR_UNREACH */
1053 .err = EHOSTUNREACH,
1054 .fatal = 0,
1055 },
1056 { /* PORT_UNREACH */
1057 .err = ECONNREFUSED,
1058 .fatal = 1,
1059 },
1060 { /* POLICY_FAIL */
1061 .err = EACCES,
1062 .fatal = 1,
1063 },
1064 { /* REJECT_ROUTE */
1065 .err = EACCES,
1066 .fatal = 1,
1067 },
1068};
1069
1070int icmpv6_err_convert(u8 type, u8 code, int *err)
1071{
1072 int fatal = 0;
1073
1074 *err = EPROTO;
1075
1076 switch (type) {
1077 case ICMPV6_DEST_UNREACH:
1078 fatal = 1;
1079 if (code < ARRAY_SIZE(tab_unreach)) {
1080 *err = tab_unreach[code].err;
1081 fatal = tab_unreach[code].fatal;
1082 }
1083 break;
1084
1085 case ICMPV6_PKT_TOOBIG:
1086 *err = EMSGSIZE;
1087 break;
1088
1089 case ICMPV6_PARAMPROB:
1090 *err = EPROTO;
1091 fatal = 1;
1092 break;
1093
1094 case ICMPV6_TIME_EXCEED:
1095 *err = EHOSTUNREACH;
1096 break;
1097 }
1098
1099 return fatal;
1100}
1101EXPORT_SYMBOL(icmpv6_err_convert);
1102
1103#ifdef CONFIG_SYSCTL
1104static struct ctl_table ipv6_icmp_table_template[] = {
1105 {
1106 .procname = "ratelimit",
1107 .data = &init_net.ipv6.sysctl.icmpv6_time,
1108 .maxlen = sizeof(int),
1109 .mode = 0644,
1110 .proc_handler = proc_dointvec_ms_jiffies,
1111 },
1112 { },
1113};
1114
1115struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1116{
1117 struct ctl_table *table;
1118
1119 table = kmemdup(ipv6_icmp_table_template,
1120 sizeof(ipv6_icmp_table_template),
1121 GFP_KERNEL);
1122
1123 if (table)
1124 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1125
1126 return table;
1127}
1128#endif