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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// 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