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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Internet Control Message Protocol (ICMPv6)
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on net/ipv4/icmp.c
10 *
11 * RFC 1885
12 */
13
14/*
15 * Changes:
16 *
17 * Andi Kleen : exception handling
18 * Andi Kleen add rate limits. never reply to a icmp.
19 * add more length checks and other fixes.
20 * yoshfuji : ensure to sent parameter problem for
21 * fragments.
22 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
23 * Randy Dunlap and
24 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
25 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
26 */
27
28#define pr_fmt(fmt) "IPv6: " fmt
29
30#include <linux/module.h>
31#include <linux/errno.h>
32#include <linux/types.h>
33#include <linux/socket.h>
34#include <linux/in.h>
35#include <linux/kernel.h>
36#include <linux/sockios.h>
37#include <linux/net.h>
38#include <linux/skbuff.h>
39#include <linux/init.h>
40#include <linux/netfilter.h>
41#include <linux/slab.h>
42
43#ifdef CONFIG_SYSCTL
44#include <linux/sysctl.h>
45#endif
46
47#include <linux/inet.h>
48#include <linux/netdevice.h>
49#include <linux/icmpv6.h>
50
51#include <net/ip.h>
52#include <net/sock.h>
53
54#include <net/ipv6.h>
55#include <net/ip6_checksum.h>
56#include <net/ping.h>
57#include <net/protocol.h>
58#include <net/raw.h>
59#include <net/rawv6.h>
60#include <net/seg6.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#include <net/dsfield.h>
68#include <net/l3mdev.h>
69
70#include <linux/uaccess.h>
71
72static DEFINE_PER_CPU(struct sock *, ipv6_icmp_sk);
73
74static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
75 u8 type, u8 code, int offset, __be32 info)
76{
77 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
78 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
79 struct net *net = dev_net_rcu(skb->dev);
80
81 if (type == ICMPV6_PKT_TOOBIG)
82 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
83 else if (type == NDISC_REDIRECT)
84 ip6_redirect(skb, net, skb->dev->ifindex, 0,
85 sock_net_uid(net, NULL));
86
87 if (!(type & ICMPV6_INFOMSG_MASK))
88 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
89 ping_err(skb, offset, ntohl(info));
90
91 return 0;
92}
93
94static int icmpv6_rcv(struct sk_buff *skb);
95
96static const struct inet6_protocol icmpv6_protocol = {
97 .handler = icmpv6_rcv,
98 .err_handler = icmpv6_err,
99 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
100};
101
102/* Called with BH disabled */
103static struct sock *icmpv6_xmit_lock(struct net *net)
104{
105 struct sock *sk;
106
107 sk = this_cpu_read(ipv6_icmp_sk);
108 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
109 /* This can happen if the output path (f.e. SIT or
110 * ip6ip6 tunnel) signals dst_link_failure() for an
111 * outgoing ICMP6 packet.
112 */
113 return NULL;
114 }
115 sock_net_set(sk, net);
116 return sk;
117}
118
119static void icmpv6_xmit_unlock(struct sock *sk)
120{
121 sock_net_set(sk, &init_net);
122 spin_unlock(&sk->sk_lock.slock);
123}
124
125/*
126 * Figure out, may we reply to this packet with icmp error.
127 *
128 * We do not reply, if:
129 * - it was icmp error message.
130 * - it is truncated, so that it is known, that protocol is ICMPV6
131 * (i.e. in the middle of some exthdr)
132 *
133 * --ANK (980726)
134 */
135
136static bool is_ineligible(const struct sk_buff *skb)
137{
138 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
139 int len = skb->len - ptr;
140 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
141 __be16 frag_off;
142
143 if (len < 0)
144 return true;
145
146 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
147 if (ptr < 0)
148 return false;
149 if (nexthdr == IPPROTO_ICMPV6) {
150 u8 _type, *tp;
151 tp = skb_header_pointer(skb,
152 ptr+offsetof(struct icmp6hdr, icmp6_type),
153 sizeof(_type), &_type);
154
155 /* Based on RFC 8200, Section 4.5 Fragment Header, return
156 * false if this is a fragment packet with no icmp header info.
157 */
158 if (!tp && frag_off != 0)
159 return false;
160 else if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
161 return true;
162 }
163 return false;
164}
165
166static bool icmpv6_mask_allow(struct net *net, int type)
167{
168 if (type > ICMPV6_MSG_MAX)
169 return true;
170
171 /* Limit if icmp type is set in ratemask. */
172 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
173 return true;
174
175 return false;
176}
177
178static bool icmpv6_global_allow(struct net *net, int type,
179 bool *apply_ratelimit)
180{
181 if (icmpv6_mask_allow(net, type))
182 return true;
183
184 if (icmp_global_allow(net)) {
185 *apply_ratelimit = true;
186 return true;
187 }
188 __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL);
189 return false;
190}
191
192/*
193 * Check the ICMP output rate limit
194 */
195static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
196 struct flowi6 *fl6, bool apply_ratelimit)
197{
198 struct net *net = sock_net(sk);
199 struct dst_entry *dst;
200 bool res = false;
201
202 if (!apply_ratelimit)
203 return true;
204
205 /*
206 * Look up the output route.
207 * XXX: perhaps the expire for routing entries cloned by
208 * this lookup should be more aggressive (not longer than timeout).
209 */
210 dst = ip6_route_output(net, sk, fl6);
211 if (dst->error) {
212 IP6_INC_STATS(net, ip6_dst_idev(dst),
213 IPSTATS_MIB_OUTNOROUTES);
214 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
215 res = true;
216 } else {
217 struct rt6_info *rt = dst_rt6_info(dst);
218 int tmo = net->ipv6.sysctl.icmpv6_time;
219 struct inet_peer *peer;
220
221 /* Give more bandwidth to wider prefixes. */
222 if (rt->rt6i_dst.plen < 128)
223 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
224
225 rcu_read_lock();
226 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr);
227 res = inet_peer_xrlim_allow(peer, tmo);
228 rcu_read_unlock();
229 }
230 if (!res)
231 __ICMP6_INC_STATS(net, ip6_dst_idev(dst),
232 ICMP6_MIB_RATELIMITHOST);
233 else
234 icmp_global_consume(net);
235 dst_release(dst);
236 return res;
237}
238
239static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type,
240 struct flowi6 *fl6)
241{
242 struct net *net = sock_net(sk);
243 struct dst_entry *dst;
244 bool res = false;
245
246 dst = ip6_route_output(net, sk, fl6);
247 if (!dst->error) {
248 struct rt6_info *rt = dst_rt6_info(dst);
249 struct in6_addr prefsrc;
250
251 rt6_get_prefsrc(rt, &prefsrc);
252 res = !ipv6_addr_any(&prefsrc);
253 }
254 dst_release(dst);
255 return res;
256}
257
258/*
259 * an inline helper for the "simple" if statement below
260 * checks if parameter problem report is caused by an
261 * unrecognized IPv6 option that has the Option Type
262 * highest-order two bits set to 10
263 */
264
265static bool opt_unrec(struct sk_buff *skb, __u32 offset)
266{
267 u8 _optval, *op;
268
269 offset += skb_network_offset(skb);
270 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
271 if (!op)
272 return true;
273 return (*op & 0xC0) == 0x80;
274}
275
276void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
277 struct icmp6hdr *thdr, int len)
278{
279 struct sk_buff *skb;
280 struct icmp6hdr *icmp6h;
281
282 skb = skb_peek(&sk->sk_write_queue);
283 if (!skb)
284 return;
285
286 icmp6h = icmp6_hdr(skb);
287 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
288 icmp6h->icmp6_cksum = 0;
289
290 if (skb_queue_len(&sk->sk_write_queue) == 1) {
291 skb->csum = csum_partial(icmp6h,
292 sizeof(struct icmp6hdr), skb->csum);
293 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
294 &fl6->daddr,
295 len, fl6->flowi6_proto,
296 skb->csum);
297 } else {
298 __wsum tmp_csum = 0;
299
300 skb_queue_walk(&sk->sk_write_queue, skb) {
301 tmp_csum = csum_add(tmp_csum, skb->csum);
302 }
303
304 tmp_csum = csum_partial(icmp6h,
305 sizeof(struct icmp6hdr), tmp_csum);
306 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
307 &fl6->daddr,
308 len, fl6->flowi6_proto,
309 tmp_csum);
310 }
311 ip6_push_pending_frames(sk);
312}
313
314struct icmpv6_msg {
315 struct sk_buff *skb;
316 int offset;
317 uint8_t type;
318};
319
320static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
321{
322 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
323 struct sk_buff *org_skb = msg->skb;
324 __wsum csum;
325
326 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
327 to, len);
328 skb->csum = csum_block_add(skb->csum, csum, odd);
329 if (!(msg->type & ICMPV6_INFOMSG_MASK))
330 nf_ct_attach(skb, org_skb);
331 return 0;
332}
333
334#if IS_ENABLED(CONFIG_IPV6_MIP6)
335static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt)
336{
337 struct ipv6hdr *iph = ipv6_hdr(skb);
338 struct ipv6_destopt_hao *hao;
339 int off;
340
341 if (opt->dsthao) {
342 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
343 if (likely(off >= 0)) {
344 hao = (struct ipv6_destopt_hao *)
345 (skb_network_header(skb) + off);
346 swap(iph->saddr, hao->addr);
347 }
348 }
349}
350#else
351static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {}
352#endif
353
354static struct dst_entry *icmpv6_route_lookup(struct net *net,
355 struct sk_buff *skb,
356 struct sock *sk,
357 struct flowi6 *fl6)
358{
359 struct dst_entry *dst, *dst2;
360 struct flowi6 fl2;
361 int err;
362
363 err = ip6_dst_lookup(net, sk, &dst, fl6);
364 if (err)
365 return ERR_PTR(err);
366
367 /*
368 * We won't send icmp if the destination is known
369 * anycast unless we need to treat anycast as unicast.
370 */
371 if (!READ_ONCE(net->ipv6.sysctl.icmpv6_error_anycast_as_unicast) &&
372 ipv6_anycast_destination(dst, &fl6->daddr)) {
373 net_dbg_ratelimited("icmp6_send: acast source\n");
374 dst_release(dst);
375 return ERR_PTR(-EINVAL);
376 }
377
378 /* No need to clone since we're just using its address. */
379 dst2 = dst;
380
381 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
382 if (!IS_ERR(dst)) {
383 if (dst != dst2)
384 return dst;
385 } else {
386 if (PTR_ERR(dst) == -EPERM)
387 dst = NULL;
388 else
389 return dst;
390 }
391
392 err = xfrm_decode_session_reverse(net, skb, flowi6_to_flowi(&fl2), AF_INET6);
393 if (err)
394 goto relookup_failed;
395
396 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
397 if (err)
398 goto relookup_failed;
399
400 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
401 if (!IS_ERR(dst2)) {
402 dst_release(dst);
403 dst = dst2;
404 } else {
405 err = PTR_ERR(dst2);
406 if (err == -EPERM) {
407 dst_release(dst);
408 return dst2;
409 } else
410 goto relookup_failed;
411 }
412
413relookup_failed:
414 if (dst)
415 return dst;
416 return ERR_PTR(err);
417}
418
419static struct net_device *icmp6_dev(const struct sk_buff *skb)
420{
421 struct net_device *dev = skb->dev;
422
423 /* for local traffic to local address, skb dev is the loopback
424 * device. Check if there is a dst attached to the skb and if so
425 * get the real device index. Same is needed for replies to a link
426 * local address on a device enslaved to an L3 master device
427 */
428 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
429 const struct rt6_info *rt6 = skb_rt6_info(skb);
430
431 /* The destination could be an external IP in Ext Hdr (SRv6, RPL, etc.),
432 * and ip6_null_entry could be set to skb if no route is found.
433 */
434 if (rt6 && rt6->rt6i_idev)
435 dev = rt6->rt6i_idev->dev;
436 }
437
438 return dev;
439}
440
441static int icmp6_iif(const struct sk_buff *skb)
442{
443 return icmp6_dev(skb)->ifindex;
444}
445
446/*
447 * Send an ICMP message in response to a packet in error
448 */
449void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
450 const struct in6_addr *force_saddr,
451 const struct inet6_skb_parm *parm)
452{
453 struct inet6_dev *idev = NULL;
454 struct ipv6hdr *hdr = ipv6_hdr(skb);
455 struct sock *sk;
456 struct net *net;
457 struct ipv6_pinfo *np;
458 const struct in6_addr *saddr = NULL;
459 bool apply_ratelimit = false;
460 struct dst_entry *dst;
461 struct icmp6hdr tmp_hdr;
462 struct flowi6 fl6;
463 struct icmpv6_msg msg;
464 struct ipcm6_cookie ipc6;
465 int iif = 0;
466 int addr_type = 0;
467 int len;
468 u32 mark;
469
470 if ((u8 *)hdr < skb->head ||
471 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
472 return;
473
474 if (!skb->dev)
475 return;
476
477 rcu_read_lock();
478
479 net = dev_net_rcu(skb->dev);
480 mark = IP6_REPLY_MARK(net, skb->mark);
481 /*
482 * Make sure we respect the rules
483 * i.e. RFC 1885 2.4(e)
484 * Rule (e.1) is enforced by not using icmp6_send
485 * in any code that processes icmp errors.
486 */
487 addr_type = ipv6_addr_type(&hdr->daddr);
488
489 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
490 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
491 saddr = &hdr->daddr;
492
493 /*
494 * Dest addr check
495 */
496
497 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
498 if (type != ICMPV6_PKT_TOOBIG &&
499 !(type == ICMPV6_PARAMPROB &&
500 code == ICMPV6_UNK_OPTION &&
501 (opt_unrec(skb, info))))
502 goto out;
503
504 saddr = NULL;
505 }
506
507 addr_type = ipv6_addr_type(&hdr->saddr);
508
509 /*
510 * Source addr check
511 */
512
513 if (__ipv6_addr_needs_scope_id(addr_type)) {
514 iif = icmp6_iif(skb);
515 } else {
516 /*
517 * The source device is used for looking up which routing table
518 * to use for sending an ICMP error.
519 */
520 iif = l3mdev_master_ifindex(skb->dev);
521 }
522
523 /*
524 * Must not send error if the source does not uniquely
525 * identify a single node (RFC2463 Section 2.4).
526 * We check unspecified / multicast addresses here,
527 * and anycast addresses will be checked later.
528 */
529 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
530 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
531 &hdr->saddr, &hdr->daddr);
532 goto out;
533 }
534
535 /*
536 * Never answer to a ICMP packet.
537 */
538 if (is_ineligible(skb)) {
539 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
540 &hdr->saddr, &hdr->daddr);
541 goto out;
542 }
543
544 /* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */
545 local_bh_disable();
546
547 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
548 if (!(skb->dev->flags & IFF_LOOPBACK) &&
549 !icmpv6_global_allow(net, type, &apply_ratelimit))
550 goto out_bh_enable;
551
552 mip6_addr_swap(skb, parm);
553
554 sk = icmpv6_xmit_lock(net);
555 if (!sk)
556 goto out_bh_enable;
557
558 memset(&fl6, 0, sizeof(fl6));
559 fl6.flowi6_proto = IPPROTO_ICMPV6;
560 fl6.daddr = hdr->saddr;
561 if (force_saddr)
562 saddr = force_saddr;
563 if (saddr) {
564 fl6.saddr = *saddr;
565 } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) {
566 /* select a more meaningful saddr from input if */
567 struct net_device *in_netdev;
568
569 in_netdev = dev_get_by_index(net, parm->iif);
570 if (in_netdev) {
571 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
572 inet6_sk(sk)->srcprefs,
573 &fl6.saddr);
574 dev_put(in_netdev);
575 }
576 }
577 fl6.flowi6_mark = mark;
578 fl6.flowi6_oif = iif;
579 fl6.fl6_icmp_type = type;
580 fl6.fl6_icmp_code = code;
581 fl6.flowi6_uid = sock_net_uid(net, NULL);
582 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
583 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
584
585 np = inet6_sk(sk);
586
587 if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit))
588 goto out_unlock;
589
590 tmp_hdr.icmp6_type = type;
591 tmp_hdr.icmp6_code = code;
592 tmp_hdr.icmp6_cksum = 0;
593 tmp_hdr.icmp6_pointer = htonl(info);
594
595 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
596 fl6.flowi6_oif = READ_ONCE(np->mcast_oif);
597 else if (!fl6.flowi6_oif)
598 fl6.flowi6_oif = READ_ONCE(np->ucast_oif);
599
600 ipcm6_init_sk(&ipc6, sk);
601 ipc6.sockc.mark = mark;
602 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
603
604 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
605 if (IS_ERR(dst))
606 goto out_unlock;
607
608 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
609
610 msg.skb = skb;
611 msg.offset = skb_network_offset(skb);
612 msg.type = type;
613
614 len = skb->len - msg.offset;
615 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
616 if (len < 0) {
617 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
618 &hdr->saddr, &hdr->daddr);
619 goto out_dst_release;
620 }
621
622 idev = __in6_dev_get(skb->dev);
623
624 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
625 len + sizeof(struct icmp6hdr),
626 sizeof(struct icmp6hdr),
627 &ipc6, &fl6, dst_rt6_info(dst),
628 MSG_DONTWAIT)) {
629 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
630 ip6_flush_pending_frames(sk);
631 } else {
632 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
633 len + sizeof(struct icmp6hdr));
634 }
635
636out_dst_release:
637 dst_release(dst);
638out_unlock:
639 icmpv6_xmit_unlock(sk);
640out_bh_enable:
641 local_bh_enable();
642out:
643 rcu_read_unlock();
644}
645EXPORT_SYMBOL(icmp6_send);
646
647/* Slightly more convenient version of icmp6_send with drop reasons.
648 */
649void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos,
650 enum skb_drop_reason reason)
651{
652 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
653 kfree_skb_reason(skb, reason);
654}
655
656/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
657 * if sufficient data bytes are available
658 * @nhs is the size of the tunnel header(s) :
659 * Either an IPv4 header for SIT encap
660 * an IPv4 header + GRE header for GRE encap
661 */
662int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
663 unsigned int data_len)
664{
665 struct in6_addr temp_saddr;
666 struct rt6_info *rt;
667 struct sk_buff *skb2;
668 u32 info = 0;
669
670 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
671 return 1;
672
673 /* RFC 4884 (partial) support for ICMP extensions */
674 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
675 data_len = 0;
676
677 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
678
679 if (!skb2)
680 return 1;
681
682 skb_dst_drop(skb2);
683 skb_pull(skb2, nhs);
684 skb_reset_network_header(skb2);
685
686 rt = rt6_lookup(dev_net_rcu(skb->dev), &ipv6_hdr(skb2)->saddr,
687 NULL, 0, skb, 0);
688
689 if (rt && rt->dst.dev)
690 skb2->dev = rt->dst.dev;
691
692 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
693
694 if (data_len) {
695 /* RFC 4884 (partial) support :
696 * insert 0 padding at the end, before the extensions
697 */
698 __skb_push(skb2, nhs);
699 skb_reset_network_header(skb2);
700 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
701 memset(skb2->data + data_len - nhs, 0, nhs);
702 /* RFC 4884 4.5 : Length is measured in 64-bit words,
703 * and stored in reserved[0]
704 */
705 info = (data_len/8) << 24;
706 }
707 if (type == ICMP_TIME_EXCEEDED)
708 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
709 info, &temp_saddr, IP6CB(skb2));
710 else
711 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
712 info, &temp_saddr, IP6CB(skb2));
713 if (rt)
714 ip6_rt_put(rt);
715
716 kfree_skb(skb2);
717
718 return 0;
719}
720EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
721
722static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb)
723{
724 struct net *net = dev_net_rcu(skb->dev);
725 struct sock *sk;
726 struct inet6_dev *idev;
727 struct ipv6_pinfo *np;
728 const struct in6_addr *saddr = NULL;
729 struct icmp6hdr *icmph = icmp6_hdr(skb);
730 bool apply_ratelimit = false;
731 struct icmp6hdr tmp_hdr;
732 struct flowi6 fl6;
733 struct icmpv6_msg msg;
734 struct dst_entry *dst;
735 struct ipcm6_cookie ipc6;
736 u32 mark = IP6_REPLY_MARK(net, skb->mark);
737 SKB_DR(reason);
738 bool acast;
739 u8 type;
740
741 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
742 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
743 return reason;
744
745 saddr = &ipv6_hdr(skb)->daddr;
746
747 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
748 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
749 return reason;
750
751 if (!ipv6_unicast_destination(skb) &&
752 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
753 saddr = NULL;
754
755 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
756 type = ICMPV6_EXT_ECHO_REPLY;
757 else
758 type = ICMPV6_ECHO_REPLY;
759
760 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
761 tmp_hdr.icmp6_type = type;
762
763 memset(&fl6, 0, sizeof(fl6));
764 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
765 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
766
767 fl6.flowi6_proto = IPPROTO_ICMPV6;
768 fl6.daddr = ipv6_hdr(skb)->saddr;
769 if (saddr)
770 fl6.saddr = *saddr;
771 fl6.flowi6_oif = icmp6_iif(skb);
772 fl6.fl6_icmp_type = type;
773 fl6.flowi6_mark = mark;
774 fl6.flowi6_uid = sock_net_uid(net, NULL);
775 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
776
777 local_bh_disable();
778 sk = icmpv6_xmit_lock(net);
779 if (!sk)
780 goto out_bh_enable;
781 np = inet6_sk(sk);
782
783 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
784 fl6.flowi6_oif = READ_ONCE(np->mcast_oif);
785 else if (!fl6.flowi6_oif)
786 fl6.flowi6_oif = READ_ONCE(np->ucast_oif);
787
788 if (ip6_dst_lookup(net, sk, &dst, &fl6))
789 goto out;
790 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
791 if (IS_ERR(dst))
792 goto out;
793
794 /* Check the ratelimit */
795 if ((!(skb->dev->flags & IFF_LOOPBACK) &&
796 !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY, &apply_ratelimit)) ||
797 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6, apply_ratelimit))
798 goto out_dst_release;
799
800 idev = __in6_dev_get(skb->dev);
801
802 msg.skb = skb;
803 msg.offset = 0;
804 msg.type = type;
805
806 ipcm6_init_sk(&ipc6, sk);
807 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
808 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
809 ipc6.sockc.mark = mark;
810
811 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
812 if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr))
813 goto out_dst_release;
814
815 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
816 skb->len + sizeof(struct icmp6hdr),
817 sizeof(struct icmp6hdr), &ipc6, &fl6,
818 dst_rt6_info(dst), MSG_DONTWAIT)) {
819 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
820 ip6_flush_pending_frames(sk);
821 } else {
822 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
823 skb->len + sizeof(struct icmp6hdr));
824 reason = SKB_CONSUMED;
825 }
826out_dst_release:
827 dst_release(dst);
828out:
829 icmpv6_xmit_unlock(sk);
830out_bh_enable:
831 local_bh_enable();
832 return reason;
833}
834
835enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type,
836 u8 code, __be32 info)
837{
838 struct inet6_skb_parm *opt = IP6CB(skb);
839 struct net *net = dev_net_rcu(skb->dev);
840 const struct inet6_protocol *ipprot;
841 enum skb_drop_reason reason;
842 int inner_offset;
843 __be16 frag_off;
844 u8 nexthdr;
845
846 reason = pskb_may_pull_reason(skb, sizeof(struct ipv6hdr));
847 if (reason != SKB_NOT_DROPPED_YET)
848 goto out;
849
850 seg6_icmp_srh(skb, opt);
851
852 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
853 if (ipv6_ext_hdr(nexthdr)) {
854 /* now skip over extension headers */
855 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
856 &nexthdr, &frag_off);
857 if (inner_offset < 0) {
858 SKB_DR_SET(reason, IPV6_BAD_EXTHDR);
859 goto out;
860 }
861 } else {
862 inner_offset = sizeof(struct ipv6hdr);
863 }
864
865 /* Checkin header including 8 bytes of inner protocol header. */
866 reason = pskb_may_pull_reason(skb, inner_offset + 8);
867 if (reason != SKB_NOT_DROPPED_YET)
868 goto out;
869
870 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
871 Without this we will not able f.e. to make source routed
872 pmtu discovery.
873 Corresponding argument (opt) to notifiers is already added.
874 --ANK (980726)
875 */
876
877 ipprot = rcu_dereference(inet6_protos[nexthdr]);
878 if (ipprot && ipprot->err_handler)
879 ipprot->err_handler(skb, opt, type, code, inner_offset, info);
880
881 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
882 return SKB_CONSUMED;
883
884out:
885 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
886 return reason;
887}
888
889/*
890 * Handle icmp messages
891 */
892
893static int icmpv6_rcv(struct sk_buff *skb)
894{
895 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
896 struct net *net = dev_net_rcu(skb->dev);
897 struct net_device *dev = icmp6_dev(skb);
898 struct inet6_dev *idev = __in6_dev_get(dev);
899 const struct in6_addr *saddr, *daddr;
900 struct icmp6hdr *hdr;
901 u8 type;
902
903 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
904 struct sec_path *sp = skb_sec_path(skb);
905 int nh;
906
907 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
908 XFRM_STATE_ICMP)) {
909 reason = SKB_DROP_REASON_XFRM_POLICY;
910 goto drop_no_count;
911 }
912
913 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
914 goto drop_no_count;
915
916 nh = skb_network_offset(skb);
917 skb_set_network_header(skb, sizeof(*hdr));
918
919 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN,
920 skb)) {
921 reason = SKB_DROP_REASON_XFRM_POLICY;
922 goto drop_no_count;
923 }
924
925 skb_set_network_header(skb, nh);
926 }
927
928 __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INMSGS);
929
930 saddr = &ipv6_hdr(skb)->saddr;
931 daddr = &ipv6_hdr(skb)->daddr;
932
933 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
934 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
935 saddr, daddr);
936 goto csum_error;
937 }
938
939 if (!pskb_pull(skb, sizeof(*hdr)))
940 goto discard_it;
941
942 hdr = icmp6_hdr(skb);
943
944 type = hdr->icmp6_type;
945
946 ICMP6MSGIN_INC_STATS(dev_net_rcu(dev), idev, type);
947
948 switch (type) {
949 case ICMPV6_ECHO_REQUEST:
950 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
951 reason = icmpv6_echo_reply(skb);
952 break;
953 case ICMPV6_EXT_ECHO_REQUEST:
954 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all &&
955 READ_ONCE(net->ipv4.sysctl_icmp_echo_enable_probe))
956 reason = icmpv6_echo_reply(skb);
957 break;
958
959 case ICMPV6_ECHO_REPLY:
960 reason = ping_rcv(skb);
961 break;
962
963 case ICMPV6_EXT_ECHO_REPLY:
964 reason = ping_rcv(skb);
965 break;
966
967 case ICMPV6_PKT_TOOBIG:
968 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
969 standard destination cache. Seems, only "advanced"
970 destination cache will allow to solve this problem
971 --ANK (980726)
972 */
973 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
974 goto discard_it;
975 hdr = icmp6_hdr(skb);
976
977 /* to notify */
978 fallthrough;
979 case ICMPV6_DEST_UNREACH:
980 case ICMPV6_TIME_EXCEED:
981 case ICMPV6_PARAMPROB:
982 reason = icmpv6_notify(skb, type, hdr->icmp6_code,
983 hdr->icmp6_mtu);
984 break;
985
986 case NDISC_ROUTER_SOLICITATION:
987 case NDISC_ROUTER_ADVERTISEMENT:
988 case NDISC_NEIGHBOUR_SOLICITATION:
989 case NDISC_NEIGHBOUR_ADVERTISEMENT:
990 case NDISC_REDIRECT:
991 reason = ndisc_rcv(skb);
992 break;
993
994 case ICMPV6_MGM_QUERY:
995 igmp6_event_query(skb);
996 return 0;
997
998 case ICMPV6_MGM_REPORT:
999 igmp6_event_report(skb);
1000 return 0;
1001
1002 case ICMPV6_MGM_REDUCTION:
1003 case ICMPV6_NI_QUERY:
1004 case ICMPV6_NI_REPLY:
1005 case ICMPV6_MLD2_REPORT:
1006 case ICMPV6_DHAAD_REQUEST:
1007 case ICMPV6_DHAAD_REPLY:
1008 case ICMPV6_MOBILE_PREFIX_SOL:
1009 case ICMPV6_MOBILE_PREFIX_ADV:
1010 break;
1011
1012 default:
1013 /* informational */
1014 if (type & ICMPV6_INFOMSG_MASK)
1015 break;
1016
1017 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
1018 saddr, daddr);
1019
1020 /*
1021 * error of unknown type.
1022 * must pass to upper level
1023 */
1024
1025 reason = icmpv6_notify(skb, type, hdr->icmp6_code,
1026 hdr->icmp6_mtu);
1027 }
1028
1029 /* until the v6 path can be better sorted assume failure and
1030 * preserve the status quo behaviour for the rest of the paths to here
1031 */
1032 if (reason)
1033 kfree_skb_reason(skb, reason);
1034 else
1035 consume_skb(skb);
1036
1037 return 0;
1038
1039csum_error:
1040 reason = SKB_DROP_REASON_ICMP_CSUM;
1041 __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_CSUMERRORS);
1042discard_it:
1043 __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INERRORS);
1044drop_no_count:
1045 kfree_skb_reason(skb, reason);
1046 return 0;
1047}
1048
1049void icmpv6_flow_init(const struct sock *sk, struct flowi6 *fl6, u8 type,
1050 const struct in6_addr *saddr,
1051 const struct in6_addr *daddr, int oif)
1052{
1053 memset(fl6, 0, sizeof(*fl6));
1054 fl6->saddr = *saddr;
1055 fl6->daddr = *daddr;
1056 fl6->flowi6_proto = IPPROTO_ICMPV6;
1057 fl6->fl6_icmp_type = type;
1058 fl6->fl6_icmp_code = 0;
1059 fl6->flowi6_oif = oif;
1060 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1061}
1062
1063int __init icmpv6_init(void)
1064{
1065 struct sock *sk;
1066 int err, i;
1067
1068 for_each_possible_cpu(i) {
1069 err = inet_ctl_sock_create(&sk, PF_INET6,
1070 SOCK_RAW, IPPROTO_ICMPV6, &init_net);
1071 if (err < 0) {
1072 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
1073 err);
1074 return err;
1075 }
1076
1077 per_cpu(ipv6_icmp_sk, i) = sk;
1078
1079 /* Enough space for 2 64K ICMP packets, including
1080 * sk_buff struct overhead.
1081 */
1082 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1083 }
1084
1085 err = -EAGAIN;
1086 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1087 goto fail;
1088
1089 err = inet6_register_icmp_sender(icmp6_send);
1090 if (err)
1091 goto sender_reg_err;
1092 return 0;
1093
1094sender_reg_err:
1095 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1096fail:
1097 pr_err("Failed to register ICMP6 protocol\n");
1098 return err;
1099}
1100
1101void icmpv6_cleanup(void)
1102{
1103 inet6_unregister_icmp_sender(icmp6_send);
1104 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1105}
1106
1107
1108static const struct icmp6_err {
1109 int err;
1110 int fatal;
1111} tab_unreach[] = {
1112 { /* NOROUTE */
1113 .err = ENETUNREACH,
1114 .fatal = 0,
1115 },
1116 { /* ADM_PROHIBITED */
1117 .err = EACCES,
1118 .fatal = 1,
1119 },
1120 { /* Was NOT_NEIGHBOUR, now reserved */
1121 .err = EHOSTUNREACH,
1122 .fatal = 0,
1123 },
1124 { /* ADDR_UNREACH */
1125 .err = EHOSTUNREACH,
1126 .fatal = 0,
1127 },
1128 { /* PORT_UNREACH */
1129 .err = ECONNREFUSED,
1130 .fatal = 1,
1131 },
1132 { /* POLICY_FAIL */
1133 .err = EACCES,
1134 .fatal = 1,
1135 },
1136 { /* REJECT_ROUTE */
1137 .err = EACCES,
1138 .fatal = 1,
1139 },
1140};
1141
1142int icmpv6_err_convert(u8 type, u8 code, int *err)
1143{
1144 int fatal = 0;
1145
1146 *err = EPROTO;
1147
1148 switch (type) {
1149 case ICMPV6_DEST_UNREACH:
1150 fatal = 1;
1151 if (code < ARRAY_SIZE(tab_unreach)) {
1152 *err = tab_unreach[code].err;
1153 fatal = tab_unreach[code].fatal;
1154 }
1155 break;
1156
1157 case ICMPV6_PKT_TOOBIG:
1158 *err = EMSGSIZE;
1159 break;
1160
1161 case ICMPV6_PARAMPROB:
1162 *err = EPROTO;
1163 fatal = 1;
1164 break;
1165
1166 case ICMPV6_TIME_EXCEED:
1167 *err = EHOSTUNREACH;
1168 break;
1169 }
1170
1171 return fatal;
1172}
1173EXPORT_SYMBOL(icmpv6_err_convert);
1174
1175#ifdef CONFIG_SYSCTL
1176static struct ctl_table ipv6_icmp_table_template[] = {
1177 {
1178 .procname = "ratelimit",
1179 .data = &init_net.ipv6.sysctl.icmpv6_time,
1180 .maxlen = sizeof(int),
1181 .mode = 0644,
1182 .proc_handler = proc_dointvec_ms_jiffies,
1183 },
1184 {
1185 .procname = "echo_ignore_all",
1186 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1187 .maxlen = sizeof(u8),
1188 .mode = 0644,
1189 .proc_handler = proc_dou8vec_minmax,
1190 },
1191 {
1192 .procname = "echo_ignore_multicast",
1193 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1194 .maxlen = sizeof(u8),
1195 .mode = 0644,
1196 .proc_handler = proc_dou8vec_minmax,
1197 },
1198 {
1199 .procname = "echo_ignore_anycast",
1200 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1201 .maxlen = sizeof(u8),
1202 .mode = 0644,
1203 .proc_handler = proc_dou8vec_minmax,
1204 },
1205 {
1206 .procname = "ratemask",
1207 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1208 .maxlen = ICMPV6_MSG_MAX + 1,
1209 .mode = 0644,
1210 .proc_handler = proc_do_large_bitmap,
1211 },
1212 {
1213 .procname = "error_anycast_as_unicast",
1214 .data = &init_net.ipv6.sysctl.icmpv6_error_anycast_as_unicast,
1215 .maxlen = sizeof(u8),
1216 .mode = 0644,
1217 .proc_handler = proc_dou8vec_minmax,
1218 .extra1 = SYSCTL_ZERO,
1219 .extra2 = SYSCTL_ONE,
1220 },
1221};
1222
1223struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1224{
1225 struct ctl_table *table;
1226
1227 table = kmemdup(ipv6_icmp_table_template,
1228 sizeof(ipv6_icmp_table_template),
1229 GFP_KERNEL);
1230
1231 if (table) {
1232 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1233 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1234 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1235 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1236 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1237 table[5].data = &net->ipv6.sysctl.icmpv6_error_anycast_as_unicast;
1238 }
1239 return table;
1240}
1241
1242size_t ipv6_icmp_sysctl_table_size(void)
1243{
1244 return ARRAY_SIZE(ipv6_icmp_table_template);
1245}
1246#endif