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1/*
2 * Internet Control Message Protocol (ICMPv6)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on net/ipv4/icmp.c
9 *
10 * RFC 1885
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18/*
19 * Changes:
20 *
21 * Andi Kleen : exception handling
22 * Andi Kleen add rate limits. never reply to a icmp.
23 * add more length checks and other fixes.
24 * yoshfuji : ensure to sent parameter problem for
25 * fragments.
26 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
27 * Randy Dunlap and
28 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
29 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
30 */
31
32#define pr_fmt(fmt) "IPv6: " fmt
33
34#include <linux/module.h>
35#include <linux/errno.h>
36#include <linux/types.h>
37#include <linux/socket.h>
38#include <linux/in.h>
39#include <linux/kernel.h>
40#include <linux/sockios.h>
41#include <linux/net.h>
42#include <linux/skbuff.h>
43#include <linux/init.h>
44#include <linux/netfilter.h>
45#include <linux/slab.h>
46
47#ifdef CONFIG_SYSCTL
48#include <linux/sysctl.h>
49#endif
50
51#include <linux/inet.h>
52#include <linux/netdevice.h>
53#include <linux/icmpv6.h>
54
55#include <net/ip.h>
56#include <net/sock.h>
57
58#include <net/ipv6.h>
59#include <net/ip6_checksum.h>
60#include <net/ping.h>
61#include <net/protocol.h>
62#include <net/raw.h>
63#include <net/rawv6.h>
64#include <net/transp_v6.h>
65#include <net/ip6_route.h>
66#include <net/addrconf.h>
67#include <net/icmp.h>
68#include <net/xfrm.h>
69#include <net/inet_common.h>
70#include <net/dsfield.h>
71#include <net/l3mdev.h>
72
73#include <asm/uaccess.h>
74
75/*
76 * The ICMP socket(s). This is the most convenient way to flow control
77 * our ICMP output as well as maintain a clean interface throughout
78 * all layers. All Socketless IP sends will soon be gone.
79 *
80 * On SMP we have one ICMP socket per-cpu.
81 */
82static inline struct sock *icmpv6_sk(struct net *net)
83{
84 return net->ipv6.icmp_sk[smp_processor_id()];
85}
86
87static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
88 u8 type, u8 code, int offset, __be32 info)
89{
90 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
91 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
92 struct net *net = dev_net(skb->dev);
93
94 if (type == ICMPV6_PKT_TOOBIG)
95 ip6_update_pmtu(skb, net, info, 0, 0);
96 else if (type == NDISC_REDIRECT)
97 ip6_redirect(skb, net, skb->dev->ifindex, 0);
98
99 if (!(type & ICMPV6_INFOMSG_MASK))
100 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
101 ping_err(skb, offset, info);
102}
103
104static int icmpv6_rcv(struct sk_buff *skb);
105
106static const struct inet6_protocol icmpv6_protocol = {
107 .handler = icmpv6_rcv,
108 .err_handler = icmpv6_err,
109 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
110};
111
112static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
113{
114 struct sock *sk;
115
116 local_bh_disable();
117
118 sk = icmpv6_sk(net);
119 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
120 /* This can happen if the output path (f.e. SIT or
121 * ip6ip6 tunnel) signals dst_link_failure() for an
122 * outgoing ICMP6 packet.
123 */
124 local_bh_enable();
125 return NULL;
126 }
127 return sk;
128}
129
130static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
131{
132 spin_unlock_bh(&sk->sk_lock.slock);
133}
134
135/*
136 * Figure out, may we reply to this packet with icmp error.
137 *
138 * We do not reply, if:
139 * - it was icmp error message.
140 * - it is truncated, so that it is known, that protocol is ICMPV6
141 * (i.e. in the middle of some exthdr)
142 *
143 * --ANK (980726)
144 */
145
146static bool is_ineligible(const struct sk_buff *skb)
147{
148 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
149 int len = skb->len - ptr;
150 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
151 __be16 frag_off;
152
153 if (len < 0)
154 return true;
155
156 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
157 if (ptr < 0)
158 return false;
159 if (nexthdr == IPPROTO_ICMPV6) {
160 u8 _type, *tp;
161 tp = skb_header_pointer(skb,
162 ptr+offsetof(struct icmp6hdr, icmp6_type),
163 sizeof(_type), &_type);
164 if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
165 return true;
166 }
167 return false;
168}
169
170/*
171 * Check the ICMP output rate limit
172 */
173static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
174 struct flowi6 *fl6)
175{
176 struct net *net = sock_net(sk);
177 struct dst_entry *dst;
178 bool res = false;
179
180 /* Informational messages are not limited. */
181 if (type & ICMPV6_INFOMSG_MASK)
182 return true;
183
184 /* Do not limit pmtu discovery, it would break it. */
185 if (type == ICMPV6_PKT_TOOBIG)
186 return true;
187
188 /*
189 * Look up the output route.
190 * XXX: perhaps the expire for routing entries cloned by
191 * this lookup should be more aggressive (not longer than timeout).
192 */
193 dst = ip6_route_output(net, sk, fl6);
194 if (dst->error) {
195 IP6_INC_STATS(net, ip6_dst_idev(dst),
196 IPSTATS_MIB_OUTNOROUTES);
197 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
198 res = true;
199 } else {
200 struct rt6_info *rt = (struct rt6_info *)dst;
201 int tmo = net->ipv6.sysctl.icmpv6_time;
202
203 /* Give more bandwidth to wider prefixes. */
204 if (rt->rt6i_dst.plen < 128)
205 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
206
207 if (icmp_global_allow()) {
208 struct inet_peer *peer;
209
210 peer = inet_getpeer_v6(net->ipv6.peers,
211 &fl6->daddr, 1);
212 res = inet_peer_xrlim_allow(peer, tmo);
213 if (peer)
214 inet_putpeer(peer);
215 }
216 }
217 dst_release(dst);
218 return res;
219}
220
221/*
222 * an inline helper for the "simple" if statement below
223 * checks if parameter problem report is caused by an
224 * unrecognized IPv6 option that has the Option Type
225 * highest-order two bits set to 10
226 */
227
228static bool opt_unrec(struct sk_buff *skb, __u32 offset)
229{
230 u8 _optval, *op;
231
232 offset += skb_network_offset(skb);
233 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
234 if (!op)
235 return true;
236 return (*op & 0xC0) == 0x80;
237}
238
239int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
240 struct icmp6hdr *thdr, int len)
241{
242 struct sk_buff *skb;
243 struct icmp6hdr *icmp6h;
244 int err = 0;
245
246 skb = skb_peek(&sk->sk_write_queue);
247 if (!skb)
248 goto out;
249
250 icmp6h = icmp6_hdr(skb);
251 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
252 icmp6h->icmp6_cksum = 0;
253
254 if (skb_queue_len(&sk->sk_write_queue) == 1) {
255 skb->csum = csum_partial(icmp6h,
256 sizeof(struct icmp6hdr), skb->csum);
257 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
258 &fl6->daddr,
259 len, fl6->flowi6_proto,
260 skb->csum);
261 } else {
262 __wsum tmp_csum = 0;
263
264 skb_queue_walk(&sk->sk_write_queue, skb) {
265 tmp_csum = csum_add(tmp_csum, skb->csum);
266 }
267
268 tmp_csum = csum_partial(icmp6h,
269 sizeof(struct icmp6hdr), tmp_csum);
270 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
271 &fl6->daddr,
272 len, fl6->flowi6_proto,
273 tmp_csum);
274 }
275 ip6_push_pending_frames(sk);
276out:
277 return err;
278}
279
280struct icmpv6_msg {
281 struct sk_buff *skb;
282 int offset;
283 uint8_t type;
284};
285
286static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
287{
288 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
289 struct sk_buff *org_skb = msg->skb;
290 __wsum csum = 0;
291
292 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
293 to, len, csum);
294 skb->csum = csum_block_add(skb->csum, csum, odd);
295 if (!(msg->type & ICMPV6_INFOMSG_MASK))
296 nf_ct_attach(skb, org_skb);
297 return 0;
298}
299
300#if IS_ENABLED(CONFIG_IPV6_MIP6)
301static void mip6_addr_swap(struct sk_buff *skb)
302{
303 struct ipv6hdr *iph = ipv6_hdr(skb);
304 struct inet6_skb_parm *opt = IP6CB(skb);
305 struct ipv6_destopt_hao *hao;
306 struct in6_addr tmp;
307 int off;
308
309 if (opt->dsthao) {
310 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
311 if (likely(off >= 0)) {
312 hao = (struct ipv6_destopt_hao *)
313 (skb_network_header(skb) + off);
314 tmp = iph->saddr;
315 iph->saddr = hao->addr;
316 hao->addr = tmp;
317 }
318 }
319}
320#else
321static inline void mip6_addr_swap(struct sk_buff *skb) {}
322#endif
323
324static struct dst_entry *icmpv6_route_lookup(struct net *net,
325 struct sk_buff *skb,
326 struct sock *sk,
327 struct flowi6 *fl6)
328{
329 struct dst_entry *dst, *dst2;
330 struct flowi6 fl2;
331 int err;
332
333 err = ip6_dst_lookup(net, sk, &dst, fl6);
334 if (err)
335 return ERR_PTR(err);
336
337 /*
338 * We won't send icmp if the destination is known
339 * anycast.
340 */
341 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
342 net_dbg_ratelimited("icmp6_send: acast source\n");
343 dst_release(dst);
344 return ERR_PTR(-EINVAL);
345 }
346
347 /* No need to clone since we're just using its address. */
348 dst2 = dst;
349
350 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
351 if (!IS_ERR(dst)) {
352 if (dst != dst2)
353 return dst;
354 } else {
355 if (PTR_ERR(dst) == -EPERM)
356 dst = NULL;
357 else
358 return dst;
359 }
360
361 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
362 if (err)
363 goto relookup_failed;
364
365 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
366 if (err)
367 goto relookup_failed;
368
369 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
370 if (!IS_ERR(dst2)) {
371 dst_release(dst);
372 dst = dst2;
373 } else {
374 err = PTR_ERR(dst2);
375 if (err == -EPERM) {
376 dst_release(dst);
377 return dst2;
378 } else
379 goto relookup_failed;
380 }
381
382relookup_failed:
383 if (dst)
384 return dst;
385 return ERR_PTR(err);
386}
387
388/*
389 * Send an ICMP message in response to a packet in error
390 */
391static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
392{
393 struct net *net = dev_net(skb->dev);
394 struct inet6_dev *idev = NULL;
395 struct ipv6hdr *hdr = ipv6_hdr(skb);
396 struct sock *sk;
397 struct ipv6_pinfo *np;
398 const struct in6_addr *saddr = NULL;
399 struct dst_entry *dst;
400 struct icmp6hdr tmp_hdr;
401 struct flowi6 fl6;
402 struct icmpv6_msg msg;
403 int iif = 0;
404 int addr_type = 0;
405 int len;
406 int hlimit;
407 int err = 0;
408 u32 mark = IP6_REPLY_MARK(net, skb->mark);
409
410 if ((u8 *)hdr < skb->head ||
411 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
412 return;
413
414 /*
415 * Make sure we respect the rules
416 * i.e. RFC 1885 2.4(e)
417 * Rule (e.1) is enforced by not using icmp6_send
418 * in any code that processes icmp errors.
419 */
420 addr_type = ipv6_addr_type(&hdr->daddr);
421
422 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
423 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
424 saddr = &hdr->daddr;
425
426 /*
427 * Dest addr check
428 */
429
430 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
431 if (type != ICMPV6_PKT_TOOBIG &&
432 !(type == ICMPV6_PARAMPROB &&
433 code == ICMPV6_UNK_OPTION &&
434 (opt_unrec(skb, info))))
435 return;
436
437 saddr = NULL;
438 }
439
440 addr_type = ipv6_addr_type(&hdr->saddr);
441
442 /*
443 * Source addr check
444 */
445
446 if (__ipv6_addr_needs_scope_id(addr_type))
447 iif = skb->dev->ifindex;
448 else
449 iif = l3mdev_master_ifindex(skb->dev);
450
451 /*
452 * Must not send error if the source does not uniquely
453 * identify a single node (RFC2463 Section 2.4).
454 * We check unspecified / multicast addresses here,
455 * and anycast addresses will be checked later.
456 */
457 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
458 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
459 &hdr->saddr, &hdr->daddr);
460 return;
461 }
462
463 /*
464 * Never answer to a ICMP packet.
465 */
466 if (is_ineligible(skb)) {
467 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
468 &hdr->saddr, &hdr->daddr);
469 return;
470 }
471
472 mip6_addr_swap(skb);
473
474 memset(&fl6, 0, sizeof(fl6));
475 fl6.flowi6_proto = IPPROTO_ICMPV6;
476 fl6.daddr = hdr->saddr;
477 if (saddr)
478 fl6.saddr = *saddr;
479 fl6.flowi6_mark = mark;
480 fl6.flowi6_oif = iif;
481 fl6.fl6_icmp_type = type;
482 fl6.fl6_icmp_code = code;
483 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
484
485 sk = icmpv6_xmit_lock(net);
486 if (!sk)
487 return;
488 sk->sk_mark = mark;
489 np = inet6_sk(sk);
490
491 if (!icmpv6_xrlim_allow(sk, type, &fl6))
492 goto out;
493
494 tmp_hdr.icmp6_type = type;
495 tmp_hdr.icmp6_code = code;
496 tmp_hdr.icmp6_cksum = 0;
497 tmp_hdr.icmp6_pointer = htonl(info);
498
499 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
500 fl6.flowi6_oif = np->mcast_oif;
501 else if (!fl6.flowi6_oif)
502 fl6.flowi6_oif = np->ucast_oif;
503
504 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
505 if (IS_ERR(dst))
506 goto out;
507
508 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
509
510 msg.skb = skb;
511 msg.offset = skb_network_offset(skb);
512 msg.type = type;
513
514 len = skb->len - msg.offset;
515 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
516 if (len < 0) {
517 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
518 &hdr->saddr, &hdr->daddr);
519 goto out_dst_release;
520 }
521
522 rcu_read_lock();
523 idev = __in6_dev_get(skb->dev);
524
525 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
526 len + sizeof(struct icmp6hdr),
527 sizeof(struct icmp6hdr), hlimit,
528 np->tclass, NULL, &fl6, (struct rt6_info *)dst,
529 MSG_DONTWAIT, np->dontfrag);
530 if (err) {
531 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
532 ip6_flush_pending_frames(sk);
533 } else {
534 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
535 len + sizeof(struct icmp6hdr));
536 }
537 rcu_read_unlock();
538out_dst_release:
539 dst_release(dst);
540out:
541 icmpv6_xmit_unlock(sk);
542}
543
544/* Slightly more convenient version of icmp6_send.
545 */
546void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
547{
548 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
549 kfree_skb(skb);
550}
551
552static void icmpv6_echo_reply(struct sk_buff *skb)
553{
554 struct net *net = dev_net(skb->dev);
555 struct sock *sk;
556 struct inet6_dev *idev;
557 struct ipv6_pinfo *np;
558 const struct in6_addr *saddr = NULL;
559 struct icmp6hdr *icmph = icmp6_hdr(skb);
560 struct icmp6hdr tmp_hdr;
561 struct flowi6 fl6;
562 struct icmpv6_msg msg;
563 struct dst_entry *dst;
564 int err = 0;
565 int hlimit;
566 u8 tclass;
567 u32 mark = IP6_REPLY_MARK(net, skb->mark);
568
569 saddr = &ipv6_hdr(skb)->daddr;
570
571 if (!ipv6_unicast_destination(skb) &&
572 !(net->ipv6.sysctl.anycast_src_echo_reply &&
573 ipv6_anycast_destination(skb_dst(skb), saddr)))
574 saddr = NULL;
575
576 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
577 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
578
579 memset(&fl6, 0, sizeof(fl6));
580 fl6.flowi6_proto = IPPROTO_ICMPV6;
581 fl6.daddr = ipv6_hdr(skb)->saddr;
582 if (saddr)
583 fl6.saddr = *saddr;
584 fl6.flowi6_oif = l3mdev_fib_oif(skb->dev);
585 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
586 fl6.flowi6_mark = mark;
587 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
588
589 sk = icmpv6_xmit_lock(net);
590 if (!sk)
591 return;
592 sk->sk_mark = mark;
593 np = inet6_sk(sk);
594
595 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
596 fl6.flowi6_oif = np->mcast_oif;
597 else if (!fl6.flowi6_oif)
598 fl6.flowi6_oif = np->ucast_oif;
599
600 err = ip6_dst_lookup(net, sk, &dst, &fl6);
601 if (err)
602 goto out;
603 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
604 if (IS_ERR(dst))
605 goto out;
606
607 hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
608
609 idev = __in6_dev_get(skb->dev);
610
611 msg.skb = skb;
612 msg.offset = 0;
613 msg.type = ICMPV6_ECHO_REPLY;
614
615 tclass = ipv6_get_dsfield(ipv6_hdr(skb));
616 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
617 sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl6,
618 (struct rt6_info *)dst, MSG_DONTWAIT,
619 np->dontfrag);
620
621 if (err) {
622 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
623 ip6_flush_pending_frames(sk);
624 } else {
625 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
626 skb->len + sizeof(struct icmp6hdr));
627 }
628 dst_release(dst);
629out:
630 icmpv6_xmit_unlock(sk);
631}
632
633void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
634{
635 const struct inet6_protocol *ipprot;
636 int inner_offset;
637 __be16 frag_off;
638 u8 nexthdr;
639 struct net *net = dev_net(skb->dev);
640
641 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
642 goto out;
643
644 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
645 if (ipv6_ext_hdr(nexthdr)) {
646 /* now skip over extension headers */
647 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
648 &nexthdr, &frag_off);
649 if (inner_offset < 0)
650 goto out;
651 } else {
652 inner_offset = sizeof(struct ipv6hdr);
653 }
654
655 /* Checkin header including 8 bytes of inner protocol header. */
656 if (!pskb_may_pull(skb, inner_offset+8))
657 goto out;
658
659 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
660 Without this we will not able f.e. to make source routed
661 pmtu discovery.
662 Corresponding argument (opt) to notifiers is already added.
663 --ANK (980726)
664 */
665
666 ipprot = rcu_dereference(inet6_protos[nexthdr]);
667 if (ipprot && ipprot->err_handler)
668 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
669
670 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
671 return;
672
673out:
674 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
675}
676
677/*
678 * Handle icmp messages
679 */
680
681static int icmpv6_rcv(struct sk_buff *skb)
682{
683 struct net_device *dev = skb->dev;
684 struct inet6_dev *idev = __in6_dev_get(dev);
685 const struct in6_addr *saddr, *daddr;
686 struct icmp6hdr *hdr;
687 u8 type;
688 bool success = false;
689
690 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
691 struct sec_path *sp = skb_sec_path(skb);
692 int nh;
693
694 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
695 XFRM_STATE_ICMP))
696 goto drop_no_count;
697
698 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
699 goto drop_no_count;
700
701 nh = skb_network_offset(skb);
702 skb_set_network_header(skb, sizeof(*hdr));
703
704 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
705 goto drop_no_count;
706
707 skb_set_network_header(skb, nh);
708 }
709
710 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
711
712 saddr = &ipv6_hdr(skb)->saddr;
713 daddr = &ipv6_hdr(skb)->daddr;
714
715 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
716 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
717 saddr, daddr);
718 goto csum_error;
719 }
720
721 if (!pskb_pull(skb, sizeof(*hdr)))
722 goto discard_it;
723
724 hdr = icmp6_hdr(skb);
725
726 type = hdr->icmp6_type;
727
728 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
729
730 switch (type) {
731 case ICMPV6_ECHO_REQUEST:
732 icmpv6_echo_reply(skb);
733 break;
734
735 case ICMPV6_ECHO_REPLY:
736 success = ping_rcv(skb);
737 break;
738
739 case ICMPV6_PKT_TOOBIG:
740 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
741 standard destination cache. Seems, only "advanced"
742 destination cache will allow to solve this problem
743 --ANK (980726)
744 */
745 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
746 goto discard_it;
747 hdr = icmp6_hdr(skb);
748
749 /*
750 * Drop through to notify
751 */
752
753 case ICMPV6_DEST_UNREACH:
754 case ICMPV6_TIME_EXCEED:
755 case ICMPV6_PARAMPROB:
756 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
757 break;
758
759 case NDISC_ROUTER_SOLICITATION:
760 case NDISC_ROUTER_ADVERTISEMENT:
761 case NDISC_NEIGHBOUR_SOLICITATION:
762 case NDISC_NEIGHBOUR_ADVERTISEMENT:
763 case NDISC_REDIRECT:
764 ndisc_rcv(skb);
765 break;
766
767 case ICMPV6_MGM_QUERY:
768 igmp6_event_query(skb);
769 break;
770
771 case ICMPV6_MGM_REPORT:
772 igmp6_event_report(skb);
773 break;
774
775 case ICMPV6_MGM_REDUCTION:
776 case ICMPV6_NI_QUERY:
777 case ICMPV6_NI_REPLY:
778 case ICMPV6_MLD2_REPORT:
779 case ICMPV6_DHAAD_REQUEST:
780 case ICMPV6_DHAAD_REPLY:
781 case ICMPV6_MOBILE_PREFIX_SOL:
782 case ICMPV6_MOBILE_PREFIX_ADV:
783 break;
784
785 default:
786 /* informational */
787 if (type & ICMPV6_INFOMSG_MASK)
788 break;
789
790 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
791 saddr, daddr);
792
793 /*
794 * error of unknown type.
795 * must pass to upper level
796 */
797
798 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
799 }
800
801 /* until the v6 path can be better sorted assume failure and
802 * preserve the status quo behaviour for the rest of the paths to here
803 */
804 if (success)
805 consume_skb(skb);
806 else
807 kfree_skb(skb);
808
809 return 0;
810
811csum_error:
812 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
813discard_it:
814 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
815drop_no_count:
816 kfree_skb(skb);
817 return 0;
818}
819
820void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
821 u8 type,
822 const struct in6_addr *saddr,
823 const struct in6_addr *daddr,
824 int oif)
825{
826 memset(fl6, 0, sizeof(*fl6));
827 fl6->saddr = *saddr;
828 fl6->daddr = *daddr;
829 fl6->flowi6_proto = IPPROTO_ICMPV6;
830 fl6->fl6_icmp_type = type;
831 fl6->fl6_icmp_code = 0;
832 fl6->flowi6_oif = oif;
833 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
834}
835
836static int __net_init icmpv6_sk_init(struct net *net)
837{
838 struct sock *sk;
839 int err, i, j;
840
841 net->ipv6.icmp_sk =
842 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
843 if (!net->ipv6.icmp_sk)
844 return -ENOMEM;
845
846 for_each_possible_cpu(i) {
847 err = inet_ctl_sock_create(&sk, PF_INET6,
848 SOCK_RAW, IPPROTO_ICMPV6, net);
849 if (err < 0) {
850 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
851 err);
852 goto fail;
853 }
854
855 net->ipv6.icmp_sk[i] = sk;
856
857 /* Enough space for 2 64K ICMP packets, including
858 * sk_buff struct overhead.
859 */
860 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
861 }
862 return 0;
863
864 fail:
865 for (j = 0; j < i; j++)
866 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
867 kfree(net->ipv6.icmp_sk);
868 return err;
869}
870
871static void __net_exit icmpv6_sk_exit(struct net *net)
872{
873 int i;
874
875 for_each_possible_cpu(i) {
876 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
877 }
878 kfree(net->ipv6.icmp_sk);
879}
880
881static struct pernet_operations icmpv6_sk_ops = {
882 .init = icmpv6_sk_init,
883 .exit = icmpv6_sk_exit,
884};
885
886int __init icmpv6_init(void)
887{
888 int err;
889
890 err = register_pernet_subsys(&icmpv6_sk_ops);
891 if (err < 0)
892 return err;
893
894 err = -EAGAIN;
895 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
896 goto fail;
897
898 err = inet6_register_icmp_sender(icmp6_send);
899 if (err)
900 goto sender_reg_err;
901 return 0;
902
903sender_reg_err:
904 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
905fail:
906 pr_err("Failed to register ICMP6 protocol\n");
907 unregister_pernet_subsys(&icmpv6_sk_ops);
908 return err;
909}
910
911void icmpv6_cleanup(void)
912{
913 inet6_unregister_icmp_sender(icmp6_send);
914 unregister_pernet_subsys(&icmpv6_sk_ops);
915 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
916}
917
918
919static const struct icmp6_err {
920 int err;
921 int fatal;
922} tab_unreach[] = {
923 { /* NOROUTE */
924 .err = ENETUNREACH,
925 .fatal = 0,
926 },
927 { /* ADM_PROHIBITED */
928 .err = EACCES,
929 .fatal = 1,
930 },
931 { /* Was NOT_NEIGHBOUR, now reserved */
932 .err = EHOSTUNREACH,
933 .fatal = 0,
934 },
935 { /* ADDR_UNREACH */
936 .err = EHOSTUNREACH,
937 .fatal = 0,
938 },
939 { /* PORT_UNREACH */
940 .err = ECONNREFUSED,
941 .fatal = 1,
942 },
943 { /* POLICY_FAIL */
944 .err = EACCES,
945 .fatal = 1,
946 },
947 { /* REJECT_ROUTE */
948 .err = EACCES,
949 .fatal = 1,
950 },
951};
952
953int icmpv6_err_convert(u8 type, u8 code, int *err)
954{
955 int fatal = 0;
956
957 *err = EPROTO;
958
959 switch (type) {
960 case ICMPV6_DEST_UNREACH:
961 fatal = 1;
962 if (code < ARRAY_SIZE(tab_unreach)) {
963 *err = tab_unreach[code].err;
964 fatal = tab_unreach[code].fatal;
965 }
966 break;
967
968 case ICMPV6_PKT_TOOBIG:
969 *err = EMSGSIZE;
970 break;
971
972 case ICMPV6_PARAMPROB:
973 *err = EPROTO;
974 fatal = 1;
975 break;
976
977 case ICMPV6_TIME_EXCEED:
978 *err = EHOSTUNREACH;
979 break;
980 }
981
982 return fatal;
983}
984EXPORT_SYMBOL(icmpv6_err_convert);
985
986#ifdef CONFIG_SYSCTL
987static struct ctl_table ipv6_icmp_table_template[] = {
988 {
989 .procname = "ratelimit",
990 .data = &init_net.ipv6.sysctl.icmpv6_time,
991 .maxlen = sizeof(int),
992 .mode = 0644,
993 .proc_handler = proc_dointvec_ms_jiffies,
994 },
995 { },
996};
997
998struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
999{
1000 struct ctl_table *table;
1001
1002 table = kmemdup(ipv6_icmp_table_template,
1003 sizeof(ipv6_icmp_table_template),
1004 GFP_KERNEL);
1005
1006 if (table)
1007 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1008
1009 return table;
1010}
1011#endif
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
113static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
114{
115 struct sock *sk;
116
117 local_bh_disable();
118
119 sk = icmpv6_sk(net);
120 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
121 /* This can happen if the output path (f.e. SIT or
122 * ip6ip6 tunnel) signals dst_link_failure() for an
123 * outgoing ICMP6 packet.
124 */
125 local_bh_enable();
126 return NULL;
127 }
128 return sk;
129}
130
131static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
132{
133 spin_unlock_bh(&sk->sk_lock.slock);
134}
135
136/*
137 * Figure out, may we reply to this packet with icmp error.
138 *
139 * We do not reply, if:
140 * - it was icmp error message.
141 * - it is truncated, so that it is known, that protocol is ICMPV6
142 * (i.e. in the middle of some exthdr)
143 *
144 * --ANK (980726)
145 */
146
147static bool is_ineligible(const struct sk_buff *skb)
148{
149 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
150 int len = skb->len - ptr;
151 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
152 __be16 frag_off;
153
154 if (len < 0)
155 return true;
156
157 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
158 if (ptr < 0)
159 return false;
160 if (nexthdr == IPPROTO_ICMPV6) {
161 u8 _type, *tp;
162 tp = skb_header_pointer(skb,
163 ptr+offsetof(struct icmp6hdr, icmp6_type),
164 sizeof(_type), &_type);
165 if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
166 return true;
167 }
168 return false;
169}
170
171/*
172 * Check the ICMP output rate limit
173 */
174static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
175 struct flowi6 *fl6)
176{
177 struct net *net = sock_net(sk);
178 struct dst_entry *dst;
179 bool res = false;
180
181 /* Informational messages are not limited. */
182 if (type & ICMPV6_INFOMSG_MASK)
183 return true;
184
185 /* Do not limit pmtu discovery, it would break it. */
186 if (type == ICMPV6_PKT_TOOBIG)
187 return true;
188
189 /*
190 * Look up the output route.
191 * XXX: perhaps the expire for routing entries cloned by
192 * this lookup should be more aggressive (not longer than timeout).
193 */
194 dst = ip6_route_output(net, sk, fl6);
195 if (dst->error) {
196 IP6_INC_STATS(net, ip6_dst_idev(dst),
197 IPSTATS_MIB_OUTNOROUTES);
198 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
199 res = true;
200 } else {
201 struct rt6_info *rt = (struct rt6_info *)dst;
202 int tmo = net->ipv6.sysctl.icmpv6_time;
203
204 /* Give more bandwidth to wider prefixes. */
205 if (rt->rt6i_dst.plen < 128)
206 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
207
208 if (icmp_global_allow()) {
209 struct inet_peer *peer;
210
211 peer = inet_getpeer_v6(net->ipv6.peers,
212 &fl6->daddr, 1);
213 res = inet_peer_xrlim_allow(peer, tmo);
214 if (peer)
215 inet_putpeer(peer);
216 }
217 }
218 dst_release(dst);
219 return res;
220}
221
222/*
223 * an inline helper for the "simple" if statement below
224 * checks if parameter problem report is caused by an
225 * unrecognized IPv6 option that has the Option Type
226 * highest-order two bits set to 10
227 */
228
229static bool opt_unrec(struct sk_buff *skb, __u32 offset)
230{
231 u8 _optval, *op;
232
233 offset += skb_network_offset(skb);
234 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
235 if (!op)
236 return true;
237 return (*op & 0xC0) == 0x80;
238}
239
240int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
241 struct icmp6hdr *thdr, int len)
242{
243 struct sk_buff *skb;
244 struct icmp6hdr *icmp6h;
245 int err = 0;
246
247 skb = skb_peek(&sk->sk_write_queue);
248 if (!skb)
249 goto out;
250
251 icmp6h = icmp6_hdr(skb);
252 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
253 icmp6h->icmp6_cksum = 0;
254
255 if (skb_queue_len(&sk->sk_write_queue) == 1) {
256 skb->csum = csum_partial(icmp6h,
257 sizeof(struct icmp6hdr), skb->csum);
258 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
259 &fl6->daddr,
260 len, fl6->flowi6_proto,
261 skb->csum);
262 } else {
263 __wsum tmp_csum = 0;
264
265 skb_queue_walk(&sk->sk_write_queue, skb) {
266 tmp_csum = csum_add(tmp_csum, skb->csum);
267 }
268
269 tmp_csum = csum_partial(icmp6h,
270 sizeof(struct icmp6hdr), tmp_csum);
271 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
272 &fl6->daddr,
273 len, fl6->flowi6_proto,
274 tmp_csum);
275 }
276 ip6_push_pending_frames(sk);
277out:
278 return err;
279}
280
281struct icmpv6_msg {
282 struct sk_buff *skb;
283 int offset;
284 uint8_t type;
285};
286
287static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
288{
289 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
290 struct sk_buff *org_skb = msg->skb;
291 __wsum csum = 0;
292
293 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
294 to, len, csum);
295 skb->csum = csum_block_add(skb->csum, csum, odd);
296 if (!(msg->type & ICMPV6_INFOMSG_MASK))
297 nf_ct_attach(skb, org_skb);
298 return 0;
299}
300
301#if IS_ENABLED(CONFIG_IPV6_MIP6)
302static void mip6_addr_swap(struct sk_buff *skb)
303{
304 struct ipv6hdr *iph = ipv6_hdr(skb);
305 struct inet6_skb_parm *opt = IP6CB(skb);
306 struct ipv6_destopt_hao *hao;
307 struct in6_addr tmp;
308 int off;
309
310 if (opt->dsthao) {
311 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
312 if (likely(off >= 0)) {
313 hao = (struct ipv6_destopt_hao *)
314 (skb_network_header(skb) + off);
315 tmp = iph->saddr;
316 iph->saddr = hao->addr;
317 hao->addr = tmp;
318 }
319 }
320}
321#else
322static inline void mip6_addr_swap(struct sk_buff *skb) {}
323#endif
324
325static struct dst_entry *icmpv6_route_lookup(struct net *net,
326 struct sk_buff *skb,
327 struct sock *sk,
328 struct flowi6 *fl6)
329{
330 struct dst_entry *dst, *dst2;
331 struct flowi6 fl2;
332 int err;
333
334 err = ip6_dst_lookup(net, sk, &dst, fl6);
335 if (err)
336 return ERR_PTR(err);
337
338 /*
339 * We won't send icmp if the destination is known
340 * anycast.
341 */
342 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
343 net_dbg_ratelimited("icmp6_send: acast source\n");
344 dst_release(dst);
345 return ERR_PTR(-EINVAL);
346 }
347
348 /* No need to clone since we're just using its address. */
349 dst2 = dst;
350
351 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
352 if (!IS_ERR(dst)) {
353 if (dst != dst2)
354 return dst;
355 } else {
356 if (PTR_ERR(dst) == -EPERM)
357 dst = NULL;
358 else
359 return dst;
360 }
361
362 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
363 if (err)
364 goto relookup_failed;
365
366 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
367 if (err)
368 goto relookup_failed;
369
370 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
371 if (!IS_ERR(dst2)) {
372 dst_release(dst);
373 dst = dst2;
374 } else {
375 err = PTR_ERR(dst2);
376 if (err == -EPERM) {
377 dst_release(dst);
378 return dst2;
379 } else
380 goto relookup_failed;
381 }
382
383relookup_failed:
384 if (dst)
385 return dst;
386 return ERR_PTR(err);
387}
388
389/*
390 * Send an ICMP message in response to a packet in error
391 */
392static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
393 const struct in6_addr *force_saddr)
394{
395 struct net *net = dev_net(skb->dev);
396 struct inet6_dev *idev = NULL;
397 struct ipv6hdr *hdr = ipv6_hdr(skb);
398 struct sock *sk;
399 struct ipv6_pinfo *np;
400 const struct in6_addr *saddr = NULL;
401 struct dst_entry *dst;
402 struct icmp6hdr tmp_hdr;
403 struct flowi6 fl6;
404 struct icmpv6_msg msg;
405 struct sockcm_cookie sockc_unused = {0};
406 struct ipcm6_cookie ipc6;
407 int iif = 0;
408 int addr_type = 0;
409 int len;
410 int err = 0;
411 u32 mark = IP6_REPLY_MARK(net, skb->mark);
412
413 if ((u8 *)hdr < skb->head ||
414 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
415 return;
416
417 /*
418 * Make sure we respect the rules
419 * i.e. RFC 1885 2.4(e)
420 * Rule (e.1) is enforced by not using icmp6_send
421 * in any code that processes icmp errors.
422 */
423 addr_type = ipv6_addr_type(&hdr->daddr);
424
425 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
426 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
427 saddr = &hdr->daddr;
428
429 /*
430 * Dest addr check
431 */
432
433 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
434 if (type != ICMPV6_PKT_TOOBIG &&
435 !(type == ICMPV6_PARAMPROB &&
436 code == ICMPV6_UNK_OPTION &&
437 (opt_unrec(skb, info))))
438 return;
439
440 saddr = NULL;
441 }
442
443 addr_type = ipv6_addr_type(&hdr->saddr);
444
445 /*
446 * Source addr check
447 */
448
449 if (__ipv6_addr_needs_scope_id(addr_type))
450 iif = skb->dev->ifindex;
451 else {
452 dst = skb_dst(skb);
453 iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
454 }
455
456 /*
457 * Must not send error if the source does not uniquely
458 * identify a single node (RFC2463 Section 2.4).
459 * We check unspecified / multicast addresses here,
460 * and anycast addresses will be checked later.
461 */
462 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
463 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
464 &hdr->saddr, &hdr->daddr);
465 return;
466 }
467
468 /*
469 * Never answer to a ICMP packet.
470 */
471 if (is_ineligible(skb)) {
472 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
473 &hdr->saddr, &hdr->daddr);
474 return;
475 }
476
477 mip6_addr_swap(skb);
478
479 memset(&fl6, 0, sizeof(fl6));
480 fl6.flowi6_proto = IPPROTO_ICMPV6;
481 fl6.daddr = hdr->saddr;
482 if (force_saddr)
483 saddr = force_saddr;
484 if (saddr)
485 fl6.saddr = *saddr;
486 fl6.flowi6_mark = mark;
487 fl6.flowi6_oif = iif;
488 fl6.fl6_icmp_type = type;
489 fl6.fl6_icmp_code = code;
490 fl6.flowi6_uid = sock_net_uid(net, NULL);
491 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
492
493 sk = icmpv6_xmit_lock(net);
494 if (!sk)
495 return;
496 sk->sk_mark = mark;
497 np = inet6_sk(sk);
498
499 if (!icmpv6_xrlim_allow(sk, type, &fl6))
500 goto out;
501
502 tmp_hdr.icmp6_type = type;
503 tmp_hdr.icmp6_code = code;
504 tmp_hdr.icmp6_cksum = 0;
505 tmp_hdr.icmp6_pointer = htonl(info);
506
507 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
508 fl6.flowi6_oif = np->mcast_oif;
509 else if (!fl6.flowi6_oif)
510 fl6.flowi6_oif = np->ucast_oif;
511
512 ipc6.tclass = np->tclass;
513 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
514
515 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
516 if (IS_ERR(dst))
517 goto out;
518
519 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
520 ipc6.dontfrag = np->dontfrag;
521 ipc6.opt = NULL;
522
523 msg.skb = skb;
524 msg.offset = skb_network_offset(skb);
525 msg.type = type;
526
527 len = skb->len - msg.offset;
528 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
529 if (len < 0) {
530 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
531 &hdr->saddr, &hdr->daddr);
532 goto out_dst_release;
533 }
534
535 rcu_read_lock();
536 idev = __in6_dev_get(skb->dev);
537
538 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
539 len + sizeof(struct icmp6hdr),
540 sizeof(struct icmp6hdr),
541 &ipc6, &fl6, (struct rt6_info *)dst,
542 MSG_DONTWAIT, &sockc_unused);
543 if (err) {
544 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
545 ip6_flush_pending_frames(sk);
546 } else {
547 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
548 len + sizeof(struct icmp6hdr));
549 }
550 rcu_read_unlock();
551out_dst_release:
552 dst_release(dst);
553out:
554 icmpv6_xmit_unlock(sk);
555}
556
557/* Slightly more convenient version of icmp6_send.
558 */
559void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
560{
561 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
562 kfree_skb(skb);
563}
564
565/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
566 * if sufficient data bytes are available
567 * @nhs is the size of the tunnel header(s) :
568 * Either an IPv4 header for SIT encap
569 * an IPv4 header + GRE header for GRE encap
570 */
571int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
572 unsigned int data_len)
573{
574 struct in6_addr temp_saddr;
575 struct rt6_info *rt;
576 struct sk_buff *skb2;
577 u32 info = 0;
578
579 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
580 return 1;
581
582 /* RFC 4884 (partial) support for ICMP extensions */
583 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
584 data_len = 0;
585
586 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
587
588 if (!skb2)
589 return 1;
590
591 skb_dst_drop(skb2);
592 skb_pull(skb2, nhs);
593 skb_reset_network_header(skb2);
594
595 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
596
597 if (rt && rt->dst.dev)
598 skb2->dev = rt->dst.dev;
599
600 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
601
602 if (data_len) {
603 /* RFC 4884 (partial) support :
604 * insert 0 padding at the end, before the extensions
605 */
606 __skb_push(skb2, nhs);
607 skb_reset_network_header(skb2);
608 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
609 memset(skb2->data + data_len - nhs, 0, nhs);
610 /* RFC 4884 4.5 : Length is measured in 64-bit words,
611 * and stored in reserved[0]
612 */
613 info = (data_len/8) << 24;
614 }
615 if (type == ICMP_TIME_EXCEEDED)
616 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
617 info, &temp_saddr);
618 else
619 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
620 info, &temp_saddr);
621 if (rt)
622 ip6_rt_put(rt);
623
624 kfree_skb(skb2);
625
626 return 0;
627}
628EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
629
630static void icmpv6_echo_reply(struct sk_buff *skb)
631{
632 struct net *net = dev_net(skb->dev);
633 struct sock *sk;
634 struct inet6_dev *idev;
635 struct ipv6_pinfo *np;
636 const struct in6_addr *saddr = NULL;
637 struct icmp6hdr *icmph = icmp6_hdr(skb);
638 struct icmp6hdr tmp_hdr;
639 struct flowi6 fl6;
640 struct icmpv6_msg msg;
641 struct dst_entry *dst;
642 struct ipcm6_cookie ipc6;
643 int err = 0;
644 u32 mark = IP6_REPLY_MARK(net, skb->mark);
645 struct sockcm_cookie sockc_unused = {0};
646
647 saddr = &ipv6_hdr(skb)->daddr;
648
649 if (!ipv6_unicast_destination(skb) &&
650 !(net->ipv6.sysctl.anycast_src_echo_reply &&
651 ipv6_anycast_destination(skb_dst(skb), saddr)))
652 saddr = NULL;
653
654 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
655 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
656
657 memset(&fl6, 0, sizeof(fl6));
658 fl6.flowi6_proto = IPPROTO_ICMPV6;
659 fl6.daddr = ipv6_hdr(skb)->saddr;
660 if (saddr)
661 fl6.saddr = *saddr;
662 fl6.flowi6_oif = skb->dev->ifindex;
663 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
664 fl6.flowi6_mark = mark;
665 fl6.flowi6_uid = sock_net_uid(net, NULL);
666 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
667
668 sk = icmpv6_xmit_lock(net);
669 if (!sk)
670 return;
671 sk->sk_mark = mark;
672 np = inet6_sk(sk);
673
674 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
675 fl6.flowi6_oif = np->mcast_oif;
676 else if (!fl6.flowi6_oif)
677 fl6.flowi6_oif = np->ucast_oif;
678
679 err = ip6_dst_lookup(net, sk, &dst, &fl6);
680 if (err)
681 goto out;
682 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
683 if (IS_ERR(dst))
684 goto out;
685
686 idev = __in6_dev_get(skb->dev);
687
688 msg.skb = skb;
689 msg.offset = 0;
690 msg.type = ICMPV6_ECHO_REPLY;
691
692 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
693 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
694 ipc6.dontfrag = np->dontfrag;
695 ipc6.opt = NULL;
696
697 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
698 sizeof(struct icmp6hdr), &ipc6, &fl6,
699 (struct rt6_info *)dst, MSG_DONTWAIT,
700 &sockc_unused);
701
702 if (err) {
703 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
704 ip6_flush_pending_frames(sk);
705 } else {
706 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
707 skb->len + sizeof(struct icmp6hdr));
708 }
709 dst_release(dst);
710out:
711 icmpv6_xmit_unlock(sk);
712}
713
714void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
715{
716 const struct inet6_protocol *ipprot;
717 int inner_offset;
718 __be16 frag_off;
719 u8 nexthdr;
720 struct net *net = dev_net(skb->dev);
721
722 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
723 goto out;
724
725 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
726 if (ipv6_ext_hdr(nexthdr)) {
727 /* now skip over extension headers */
728 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
729 &nexthdr, &frag_off);
730 if (inner_offset < 0)
731 goto out;
732 } else {
733 inner_offset = sizeof(struct ipv6hdr);
734 }
735
736 /* Checkin header including 8 bytes of inner protocol header. */
737 if (!pskb_may_pull(skb, inner_offset+8))
738 goto out;
739
740 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
741 Without this we will not able f.e. to make source routed
742 pmtu discovery.
743 Corresponding argument (opt) to notifiers is already added.
744 --ANK (980726)
745 */
746
747 ipprot = rcu_dereference(inet6_protos[nexthdr]);
748 if (ipprot && ipprot->err_handler)
749 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
750
751 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
752 return;
753
754out:
755 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
756}
757
758/*
759 * Handle icmp messages
760 */
761
762static int icmpv6_rcv(struct sk_buff *skb)
763{
764 struct net_device *dev = skb->dev;
765 struct inet6_dev *idev = __in6_dev_get(dev);
766 const struct in6_addr *saddr, *daddr;
767 struct icmp6hdr *hdr;
768 u8 type;
769 bool success = false;
770
771 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
772 struct sec_path *sp = skb_sec_path(skb);
773 int nh;
774
775 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
776 XFRM_STATE_ICMP))
777 goto drop_no_count;
778
779 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
780 goto drop_no_count;
781
782 nh = skb_network_offset(skb);
783 skb_set_network_header(skb, sizeof(*hdr));
784
785 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
786 goto drop_no_count;
787
788 skb_set_network_header(skb, nh);
789 }
790
791 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
792
793 saddr = &ipv6_hdr(skb)->saddr;
794 daddr = &ipv6_hdr(skb)->daddr;
795
796 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
797 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
798 saddr, daddr);
799 goto csum_error;
800 }
801
802 if (!pskb_pull(skb, sizeof(*hdr)))
803 goto discard_it;
804
805 hdr = icmp6_hdr(skb);
806
807 type = hdr->icmp6_type;
808
809 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
810
811 switch (type) {
812 case ICMPV6_ECHO_REQUEST:
813 icmpv6_echo_reply(skb);
814 break;
815
816 case ICMPV6_ECHO_REPLY:
817 success = ping_rcv(skb);
818 break;
819
820 case ICMPV6_PKT_TOOBIG:
821 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
822 standard destination cache. Seems, only "advanced"
823 destination cache will allow to solve this problem
824 --ANK (980726)
825 */
826 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
827 goto discard_it;
828 hdr = icmp6_hdr(skb);
829
830 /*
831 * Drop through to notify
832 */
833
834 case ICMPV6_DEST_UNREACH:
835 case ICMPV6_TIME_EXCEED:
836 case ICMPV6_PARAMPROB:
837 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
838 break;
839
840 case NDISC_ROUTER_SOLICITATION:
841 case NDISC_ROUTER_ADVERTISEMENT:
842 case NDISC_NEIGHBOUR_SOLICITATION:
843 case NDISC_NEIGHBOUR_ADVERTISEMENT:
844 case NDISC_REDIRECT:
845 ndisc_rcv(skb);
846 break;
847
848 case ICMPV6_MGM_QUERY:
849 igmp6_event_query(skb);
850 break;
851
852 case ICMPV6_MGM_REPORT:
853 igmp6_event_report(skb);
854 break;
855
856 case ICMPV6_MGM_REDUCTION:
857 case ICMPV6_NI_QUERY:
858 case ICMPV6_NI_REPLY:
859 case ICMPV6_MLD2_REPORT:
860 case ICMPV6_DHAAD_REQUEST:
861 case ICMPV6_DHAAD_REPLY:
862 case ICMPV6_MOBILE_PREFIX_SOL:
863 case ICMPV6_MOBILE_PREFIX_ADV:
864 break;
865
866 default:
867 /* informational */
868 if (type & ICMPV6_INFOMSG_MASK)
869 break;
870
871 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
872 saddr, daddr);
873
874 /*
875 * error of unknown type.
876 * must pass to upper level
877 */
878
879 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
880 }
881
882 /* until the v6 path can be better sorted assume failure and
883 * preserve the status quo behaviour for the rest of the paths to here
884 */
885 if (success)
886 consume_skb(skb);
887 else
888 kfree_skb(skb);
889
890 return 0;
891
892csum_error:
893 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
894discard_it:
895 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
896drop_no_count:
897 kfree_skb(skb);
898 return 0;
899}
900
901void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
902 u8 type,
903 const struct in6_addr *saddr,
904 const struct in6_addr *daddr,
905 int oif)
906{
907 memset(fl6, 0, sizeof(*fl6));
908 fl6->saddr = *saddr;
909 fl6->daddr = *daddr;
910 fl6->flowi6_proto = IPPROTO_ICMPV6;
911 fl6->fl6_icmp_type = type;
912 fl6->fl6_icmp_code = 0;
913 fl6->flowi6_oif = oif;
914 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
915}
916
917static int __net_init icmpv6_sk_init(struct net *net)
918{
919 struct sock *sk;
920 int err, i, j;
921
922 net->ipv6.icmp_sk =
923 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
924 if (!net->ipv6.icmp_sk)
925 return -ENOMEM;
926
927 for_each_possible_cpu(i) {
928 err = inet_ctl_sock_create(&sk, PF_INET6,
929 SOCK_RAW, IPPROTO_ICMPV6, net);
930 if (err < 0) {
931 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
932 err);
933 goto fail;
934 }
935
936 net->ipv6.icmp_sk[i] = sk;
937
938 /* Enough space for 2 64K ICMP packets, including
939 * sk_buff struct overhead.
940 */
941 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
942 }
943 return 0;
944
945 fail:
946 for (j = 0; j < i; j++)
947 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
948 kfree(net->ipv6.icmp_sk);
949 return err;
950}
951
952static void __net_exit icmpv6_sk_exit(struct net *net)
953{
954 int i;
955
956 for_each_possible_cpu(i) {
957 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
958 }
959 kfree(net->ipv6.icmp_sk);
960}
961
962static struct pernet_operations icmpv6_sk_ops = {
963 .init = icmpv6_sk_init,
964 .exit = icmpv6_sk_exit,
965};
966
967int __init icmpv6_init(void)
968{
969 int err;
970
971 err = register_pernet_subsys(&icmpv6_sk_ops);
972 if (err < 0)
973 return err;
974
975 err = -EAGAIN;
976 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
977 goto fail;
978
979 err = inet6_register_icmp_sender(icmp6_send);
980 if (err)
981 goto sender_reg_err;
982 return 0;
983
984sender_reg_err:
985 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
986fail:
987 pr_err("Failed to register ICMP6 protocol\n");
988 unregister_pernet_subsys(&icmpv6_sk_ops);
989 return err;
990}
991
992void icmpv6_cleanup(void)
993{
994 inet6_unregister_icmp_sender(icmp6_send);
995 unregister_pernet_subsys(&icmpv6_sk_ops);
996 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
997}
998
999
1000static const struct icmp6_err {
1001 int err;
1002 int fatal;
1003} tab_unreach[] = {
1004 { /* NOROUTE */
1005 .err = ENETUNREACH,
1006 .fatal = 0,
1007 },
1008 { /* ADM_PROHIBITED */
1009 .err = EACCES,
1010 .fatal = 1,
1011 },
1012 { /* Was NOT_NEIGHBOUR, now reserved */
1013 .err = EHOSTUNREACH,
1014 .fatal = 0,
1015 },
1016 { /* ADDR_UNREACH */
1017 .err = EHOSTUNREACH,
1018 .fatal = 0,
1019 },
1020 { /* PORT_UNREACH */
1021 .err = ECONNREFUSED,
1022 .fatal = 1,
1023 },
1024 { /* POLICY_FAIL */
1025 .err = EACCES,
1026 .fatal = 1,
1027 },
1028 { /* REJECT_ROUTE */
1029 .err = EACCES,
1030 .fatal = 1,
1031 },
1032};
1033
1034int icmpv6_err_convert(u8 type, u8 code, int *err)
1035{
1036 int fatal = 0;
1037
1038 *err = EPROTO;
1039
1040 switch (type) {
1041 case ICMPV6_DEST_UNREACH:
1042 fatal = 1;
1043 if (code < ARRAY_SIZE(tab_unreach)) {
1044 *err = tab_unreach[code].err;
1045 fatal = tab_unreach[code].fatal;
1046 }
1047 break;
1048
1049 case ICMPV6_PKT_TOOBIG:
1050 *err = EMSGSIZE;
1051 break;
1052
1053 case ICMPV6_PARAMPROB:
1054 *err = EPROTO;
1055 fatal = 1;
1056 break;
1057
1058 case ICMPV6_TIME_EXCEED:
1059 *err = EHOSTUNREACH;
1060 break;
1061 }
1062
1063 return fatal;
1064}
1065EXPORT_SYMBOL(icmpv6_err_convert);
1066
1067#ifdef CONFIG_SYSCTL
1068static struct ctl_table ipv6_icmp_table_template[] = {
1069 {
1070 .procname = "ratelimit",
1071 .data = &init_net.ipv6.sysctl.icmpv6_time,
1072 .maxlen = sizeof(int),
1073 .mode = 0644,
1074 .proc_handler = proc_dointvec_ms_jiffies,
1075 },
1076 { },
1077};
1078
1079struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1080{
1081 struct ctl_table *table;
1082
1083 table = kmemdup(ipv6_icmp_table_template,
1084 sizeof(ipv6_icmp_table_template),
1085 GFP_KERNEL);
1086
1087 if (table)
1088 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1089
1090 return table;
1091}
1092#endif