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