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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
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/transp_v6.h>
61#include <net/ip6_route.h>
62#include <net/addrconf.h>
63#include <net/icmp.h>
64#include <net/xfrm.h>
65#include <net/inet_common.h>
66#include <net/dsfield.h>
67#include <net/l3mdev.h>
68
69#include <linux/uaccess.h>
70
71/*
72 * The ICMP socket(s). This is the most convenient way to flow control
73 * our ICMP output as well as maintain a clean interface throughout
74 * all layers. All Socketless IP sends will soon be gone.
75 *
76 * On SMP we have one ICMP socket per-cpu.
77 */
78static struct sock *icmpv6_sk(struct net *net)
79{
80 return this_cpu_read(*net->ipv6.icmp_sk);
81}
82
83static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
84 u8 type, u8 code, int offset, __be32 info)
85{
86 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
87 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
88 struct net *net = dev_net(skb->dev);
89
90 if (type == ICMPV6_PKT_TOOBIG)
91 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
92 else if (type == NDISC_REDIRECT)
93 ip6_redirect(skb, net, skb->dev->ifindex, 0,
94 sock_net_uid(net, NULL));
95
96 if (!(type & ICMPV6_INFOMSG_MASK))
97 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
98 ping_err(skb, offset, ntohl(info));
99
100 return 0;
101}
102
103static int icmpv6_rcv(struct sk_buff *skb);
104
105static const struct inet6_protocol icmpv6_protocol = {
106 .handler = icmpv6_rcv,
107 .err_handler = icmpv6_err,
108 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
109};
110
111/* Called with BH disabled */
112static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
113{
114 struct sock *sk;
115
116 sk = icmpv6_sk(net);
117 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
118 /* This can happen if the output path (f.e. SIT or
119 * ip6ip6 tunnel) signals dst_link_failure() for an
120 * outgoing ICMP6 packet.
121 */
122 return NULL;
123 }
124 return sk;
125}
126
127static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
128{
129 spin_unlock(&sk->sk_lock.slock);
130}
131
132/*
133 * Figure out, may we reply to this packet with icmp error.
134 *
135 * We do not reply, if:
136 * - it was icmp error message.
137 * - it is truncated, so that it is known, that protocol is ICMPV6
138 * (i.e. in the middle of some exthdr)
139 *
140 * --ANK (980726)
141 */
142
143static bool is_ineligible(const struct sk_buff *skb)
144{
145 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
146 int len = skb->len - ptr;
147 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
148 __be16 frag_off;
149
150 if (len < 0)
151 return true;
152
153 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
154 if (ptr < 0)
155 return false;
156 if (nexthdr == IPPROTO_ICMPV6) {
157 u8 _type, *tp;
158 tp = skb_header_pointer(skb,
159 ptr+offsetof(struct icmp6hdr, icmp6_type),
160 sizeof(_type), &_type);
161 if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
162 return true;
163 }
164 return false;
165}
166
167static bool icmpv6_mask_allow(struct net *net, int type)
168{
169 if (type > ICMPV6_MSG_MAX)
170 return true;
171
172 /* Limit if icmp type is set in ratemask. */
173 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
174 return true;
175
176 return false;
177}
178
179static bool icmpv6_global_allow(struct net *net, int type)
180{
181 if (icmpv6_mask_allow(net, type))
182 return true;
183
184 if (icmp_global_allow())
185 return true;
186
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 dst_release(dst);
229 return res;
230}
231
232/*
233 * an inline helper for the "simple" if statement below
234 * checks if parameter problem report is caused by an
235 * unrecognized IPv6 option that has the Option Type
236 * highest-order two bits set to 10
237 */
238
239static bool opt_unrec(struct sk_buff *skb, __u32 offset)
240{
241 u8 _optval, *op;
242
243 offset += skb_network_offset(skb);
244 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
245 if (!op)
246 return true;
247 return (*op & 0xC0) == 0x80;
248}
249
250void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
251 struct icmp6hdr *thdr, int len)
252{
253 struct sk_buff *skb;
254 struct icmp6hdr *icmp6h;
255
256 skb = skb_peek(&sk->sk_write_queue);
257 if (!skb)
258 return;
259
260 icmp6h = icmp6_hdr(skb);
261 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
262 icmp6h->icmp6_cksum = 0;
263
264 if (skb_queue_len(&sk->sk_write_queue) == 1) {
265 skb->csum = csum_partial(icmp6h,
266 sizeof(struct icmp6hdr), skb->csum);
267 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
268 &fl6->daddr,
269 len, fl6->flowi6_proto,
270 skb->csum);
271 } else {
272 __wsum tmp_csum = 0;
273
274 skb_queue_walk(&sk->sk_write_queue, skb) {
275 tmp_csum = csum_add(tmp_csum, skb->csum);
276 }
277
278 tmp_csum = csum_partial(icmp6h,
279 sizeof(struct icmp6hdr), tmp_csum);
280 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
281 &fl6->daddr,
282 len, fl6->flowi6_proto,
283 tmp_csum);
284 }
285 ip6_push_pending_frames(sk);
286}
287
288struct icmpv6_msg {
289 struct sk_buff *skb;
290 int offset;
291 uint8_t type;
292};
293
294static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
295{
296 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
297 struct sk_buff *org_skb = msg->skb;
298 __wsum csum = 0;
299
300 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
301 to, len, csum);
302 skb->csum = csum_block_add(skb->csum, csum, odd);
303 if (!(msg->type & ICMPV6_INFOMSG_MASK))
304 nf_ct_attach(skb, org_skb);
305 return 0;
306}
307
308#if IS_ENABLED(CONFIG_IPV6_MIP6)
309static void mip6_addr_swap(struct sk_buff *skb)
310{
311 struct ipv6hdr *iph = ipv6_hdr(skb);
312 struct inet6_skb_parm *opt = IP6CB(skb);
313 struct ipv6_destopt_hao *hao;
314 struct in6_addr tmp;
315 int off;
316
317 if (opt->dsthao) {
318 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
319 if (likely(off >= 0)) {
320 hao = (struct ipv6_destopt_hao *)
321 (skb_network_header(skb) + off);
322 tmp = iph->saddr;
323 iph->saddr = hao->addr;
324 hao->addr = tmp;
325 }
326 }
327}
328#else
329static inline void mip6_addr_swap(struct sk_buff *skb) {}
330#endif
331
332static struct dst_entry *icmpv6_route_lookup(struct net *net,
333 struct sk_buff *skb,
334 struct sock *sk,
335 struct flowi6 *fl6)
336{
337 struct dst_entry *dst, *dst2;
338 struct flowi6 fl2;
339 int err;
340
341 err = ip6_dst_lookup(net, sk, &dst, fl6);
342 if (err)
343 return ERR_PTR(err);
344
345 /*
346 * We won't send icmp if the destination is known
347 * anycast.
348 */
349 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
350 net_dbg_ratelimited("icmp6_send: acast source\n");
351 dst_release(dst);
352 return ERR_PTR(-EINVAL);
353 }
354
355 /* No need to clone since we're just using its address. */
356 dst2 = dst;
357
358 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
359 if (!IS_ERR(dst)) {
360 if (dst != dst2)
361 return dst;
362 } else {
363 if (PTR_ERR(dst) == -EPERM)
364 dst = NULL;
365 else
366 return dst;
367 }
368
369 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
370 if (err)
371 goto relookup_failed;
372
373 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
374 if (err)
375 goto relookup_failed;
376
377 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
378 if (!IS_ERR(dst2)) {
379 dst_release(dst);
380 dst = dst2;
381 } else {
382 err = PTR_ERR(dst2);
383 if (err == -EPERM) {
384 dst_release(dst);
385 return dst2;
386 } else
387 goto relookup_failed;
388 }
389
390relookup_failed:
391 if (dst)
392 return dst;
393 return ERR_PTR(err);
394}
395
396static struct net_device *icmp6_dev(const struct sk_buff *skb)
397{
398 struct net_device *dev = skb->dev;
399
400 /* for local traffic to local address, skb dev is the loopback
401 * device. Check if there is a dst attached to the skb and if so
402 * get the real device index. Same is needed for replies to a link
403 * local address on a device enslaved to an L3 master device
404 */
405 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
406 const struct rt6_info *rt6 = skb_rt6_info(skb);
407
408 if (rt6)
409 dev = rt6->rt6i_idev->dev;
410 }
411
412 return dev;
413}
414
415static int icmp6_iif(const struct sk_buff *skb)
416{
417 return icmp6_dev(skb)->ifindex;
418}
419
420/*
421 * Send an ICMP message in response to a packet in error
422 */
423static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
424 const struct in6_addr *force_saddr)
425{
426 struct inet6_dev *idev = NULL;
427 struct ipv6hdr *hdr = ipv6_hdr(skb);
428 struct sock *sk;
429 struct net *net;
430 struct ipv6_pinfo *np;
431 const struct in6_addr *saddr = NULL;
432 struct dst_entry *dst;
433 struct icmp6hdr tmp_hdr;
434 struct flowi6 fl6;
435 struct icmpv6_msg msg;
436 struct ipcm6_cookie ipc6;
437 int iif = 0;
438 int addr_type = 0;
439 int len;
440 u32 mark;
441
442 if ((u8 *)hdr < skb->head ||
443 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
444 return;
445
446 if (!skb->dev)
447 return;
448 net = dev_net(skb->dev);
449 mark = IP6_REPLY_MARK(net, skb->mark);
450 /*
451 * Make sure we respect the rules
452 * i.e. RFC 1885 2.4(e)
453 * Rule (e.1) is enforced by not using icmp6_send
454 * in any code that processes icmp errors.
455 */
456 addr_type = ipv6_addr_type(&hdr->daddr);
457
458 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
459 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
460 saddr = &hdr->daddr;
461
462 /*
463 * Dest addr check
464 */
465
466 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
467 if (type != ICMPV6_PKT_TOOBIG &&
468 !(type == ICMPV6_PARAMPROB &&
469 code == ICMPV6_UNK_OPTION &&
470 (opt_unrec(skb, info))))
471 return;
472
473 saddr = NULL;
474 }
475
476 addr_type = ipv6_addr_type(&hdr->saddr);
477
478 /*
479 * Source addr check
480 */
481
482 if (__ipv6_addr_needs_scope_id(addr_type)) {
483 iif = icmp6_iif(skb);
484 } else {
485 dst = skb_dst(skb);
486 iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
487 }
488
489 /*
490 * Must not send error if the source does not uniquely
491 * identify a single node (RFC2463 Section 2.4).
492 * We check unspecified / multicast addresses here,
493 * and anycast addresses will be checked later.
494 */
495 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
496 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
497 &hdr->saddr, &hdr->daddr);
498 return;
499 }
500
501 /*
502 * Never answer to a ICMP packet.
503 */
504 if (is_ineligible(skb)) {
505 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
506 &hdr->saddr, &hdr->daddr);
507 return;
508 }
509
510 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
511 local_bh_disable();
512
513 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
514 if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
515 goto out_bh_enable;
516
517 mip6_addr_swap(skb);
518
519 memset(&fl6, 0, sizeof(fl6));
520 fl6.flowi6_proto = IPPROTO_ICMPV6;
521 fl6.daddr = hdr->saddr;
522 if (force_saddr)
523 saddr = force_saddr;
524 if (saddr)
525 fl6.saddr = *saddr;
526 fl6.flowi6_mark = mark;
527 fl6.flowi6_oif = iif;
528 fl6.fl6_icmp_type = type;
529 fl6.fl6_icmp_code = code;
530 fl6.flowi6_uid = sock_net_uid(net, NULL);
531 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
532 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
533
534 sk = icmpv6_xmit_lock(net);
535 if (!sk)
536 goto out_bh_enable;
537
538 sk->sk_mark = mark;
539 np = inet6_sk(sk);
540
541 if (!icmpv6_xrlim_allow(sk, type, &fl6))
542 goto out;
543
544 tmp_hdr.icmp6_type = type;
545 tmp_hdr.icmp6_code = code;
546 tmp_hdr.icmp6_cksum = 0;
547 tmp_hdr.icmp6_pointer = htonl(info);
548
549 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
550 fl6.flowi6_oif = np->mcast_oif;
551 else if (!fl6.flowi6_oif)
552 fl6.flowi6_oif = np->ucast_oif;
553
554 ipcm6_init_sk(&ipc6, np);
555 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
556
557 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
558 if (IS_ERR(dst))
559 goto out;
560
561 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
562
563 msg.skb = skb;
564 msg.offset = skb_network_offset(skb);
565 msg.type = type;
566
567 len = skb->len - msg.offset;
568 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
569 if (len < 0) {
570 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
571 &hdr->saddr, &hdr->daddr);
572 goto out_dst_release;
573 }
574
575 rcu_read_lock();
576 idev = __in6_dev_get(skb->dev);
577
578 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
579 len + sizeof(struct icmp6hdr),
580 sizeof(struct icmp6hdr),
581 &ipc6, &fl6, (struct rt6_info *)dst,
582 MSG_DONTWAIT)) {
583 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
584 ip6_flush_pending_frames(sk);
585 } else {
586 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
587 len + sizeof(struct icmp6hdr));
588 }
589 rcu_read_unlock();
590out_dst_release:
591 dst_release(dst);
592out:
593 icmpv6_xmit_unlock(sk);
594out_bh_enable:
595 local_bh_enable();
596}
597
598/* Slightly more convenient version of icmp6_send.
599 */
600void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
601{
602 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
603 kfree_skb(skb);
604}
605
606/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
607 * if sufficient data bytes are available
608 * @nhs is the size of the tunnel header(s) :
609 * Either an IPv4 header for SIT encap
610 * an IPv4 header + GRE header for GRE encap
611 */
612int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
613 unsigned int data_len)
614{
615 struct in6_addr temp_saddr;
616 struct rt6_info *rt;
617 struct sk_buff *skb2;
618 u32 info = 0;
619
620 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
621 return 1;
622
623 /* RFC 4884 (partial) support for ICMP extensions */
624 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
625 data_len = 0;
626
627 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
628
629 if (!skb2)
630 return 1;
631
632 skb_dst_drop(skb2);
633 skb_pull(skb2, nhs);
634 skb_reset_network_header(skb2);
635
636 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
637 skb, 0);
638
639 if (rt && rt->dst.dev)
640 skb2->dev = rt->dst.dev;
641
642 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
643
644 if (data_len) {
645 /* RFC 4884 (partial) support :
646 * insert 0 padding at the end, before the extensions
647 */
648 __skb_push(skb2, nhs);
649 skb_reset_network_header(skb2);
650 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
651 memset(skb2->data + data_len - nhs, 0, nhs);
652 /* RFC 4884 4.5 : Length is measured in 64-bit words,
653 * and stored in reserved[0]
654 */
655 info = (data_len/8) << 24;
656 }
657 if (type == ICMP_TIME_EXCEEDED)
658 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
659 info, &temp_saddr);
660 else
661 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
662 info, &temp_saddr);
663 if (rt)
664 ip6_rt_put(rt);
665
666 kfree_skb(skb2);
667
668 return 0;
669}
670EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
671
672static void icmpv6_echo_reply(struct sk_buff *skb)
673{
674 struct net *net = dev_net(skb->dev);
675 struct sock *sk;
676 struct inet6_dev *idev;
677 struct ipv6_pinfo *np;
678 const struct in6_addr *saddr = NULL;
679 struct icmp6hdr *icmph = icmp6_hdr(skb);
680 struct icmp6hdr tmp_hdr;
681 struct flowi6 fl6;
682 struct icmpv6_msg msg;
683 struct dst_entry *dst;
684 struct ipcm6_cookie ipc6;
685 u32 mark = IP6_REPLY_MARK(net, skb->mark);
686 bool acast;
687
688 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
689 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
690 return;
691
692 saddr = &ipv6_hdr(skb)->daddr;
693
694 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
695 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
696 return;
697
698 if (!ipv6_unicast_destination(skb) &&
699 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
700 saddr = NULL;
701
702 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
703 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
704
705 memset(&fl6, 0, sizeof(fl6));
706 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
707 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
708
709 fl6.flowi6_proto = IPPROTO_ICMPV6;
710 fl6.daddr = ipv6_hdr(skb)->saddr;
711 if (saddr)
712 fl6.saddr = *saddr;
713 fl6.flowi6_oif = icmp6_iif(skb);
714 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
715 fl6.flowi6_mark = mark;
716 fl6.flowi6_uid = sock_net_uid(net, NULL);
717 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
718
719 local_bh_disable();
720 sk = icmpv6_xmit_lock(net);
721 if (!sk)
722 goto out_bh_enable;
723 sk->sk_mark = mark;
724 np = inet6_sk(sk);
725
726 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
727 fl6.flowi6_oif = np->mcast_oif;
728 else if (!fl6.flowi6_oif)
729 fl6.flowi6_oif = np->ucast_oif;
730
731 if (ip6_dst_lookup(net, sk, &dst, &fl6))
732 goto out;
733 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
734 if (IS_ERR(dst))
735 goto out;
736
737 /* Check the ratelimit */
738 if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
739 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
740 goto out_dst_release;
741
742 idev = __in6_dev_get(skb->dev);
743
744 msg.skb = skb;
745 msg.offset = 0;
746 msg.type = ICMPV6_ECHO_REPLY;
747
748 ipcm6_init_sk(&ipc6, np);
749 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
750 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
751
752 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
753 skb->len + sizeof(struct icmp6hdr),
754 sizeof(struct icmp6hdr), &ipc6, &fl6,
755 (struct rt6_info *)dst, MSG_DONTWAIT)) {
756 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
757 ip6_flush_pending_frames(sk);
758 } else {
759 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
760 skb->len + sizeof(struct icmp6hdr));
761 }
762out_dst_release:
763 dst_release(dst);
764out:
765 icmpv6_xmit_unlock(sk);
766out_bh_enable:
767 local_bh_enable();
768}
769
770void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
771{
772 const struct inet6_protocol *ipprot;
773 int inner_offset;
774 __be16 frag_off;
775 u8 nexthdr;
776 struct net *net = dev_net(skb->dev);
777
778 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
779 goto out;
780
781 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
782 if (ipv6_ext_hdr(nexthdr)) {
783 /* now skip over extension headers */
784 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
785 &nexthdr, &frag_off);
786 if (inner_offset < 0)
787 goto out;
788 } else {
789 inner_offset = sizeof(struct ipv6hdr);
790 }
791
792 /* Checkin header including 8 bytes of inner protocol header. */
793 if (!pskb_may_pull(skb, inner_offset+8))
794 goto out;
795
796 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
797 Without this we will not able f.e. to make source routed
798 pmtu discovery.
799 Corresponding argument (opt) to notifiers is already added.
800 --ANK (980726)
801 */
802
803 ipprot = rcu_dereference(inet6_protos[nexthdr]);
804 if (ipprot && ipprot->err_handler)
805 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
806
807 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
808 return;
809
810out:
811 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
812}
813
814/*
815 * Handle icmp messages
816 */
817
818static int icmpv6_rcv(struct sk_buff *skb)
819{
820 struct net *net = dev_net(skb->dev);
821 struct net_device *dev = icmp6_dev(skb);
822 struct inet6_dev *idev = __in6_dev_get(dev);
823 const struct in6_addr *saddr, *daddr;
824 struct icmp6hdr *hdr;
825 u8 type;
826 bool success = false;
827
828 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
829 struct sec_path *sp = skb_sec_path(skb);
830 int nh;
831
832 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
833 XFRM_STATE_ICMP))
834 goto drop_no_count;
835
836 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
837 goto drop_no_count;
838
839 nh = skb_network_offset(skb);
840 skb_set_network_header(skb, sizeof(*hdr));
841
842 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
843 goto drop_no_count;
844
845 skb_set_network_header(skb, nh);
846 }
847
848 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
849
850 saddr = &ipv6_hdr(skb)->saddr;
851 daddr = &ipv6_hdr(skb)->daddr;
852
853 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
854 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
855 saddr, daddr);
856 goto csum_error;
857 }
858
859 if (!pskb_pull(skb, sizeof(*hdr)))
860 goto discard_it;
861
862 hdr = icmp6_hdr(skb);
863
864 type = hdr->icmp6_type;
865
866 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
867
868 switch (type) {
869 case ICMPV6_ECHO_REQUEST:
870 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
871 icmpv6_echo_reply(skb);
872 break;
873
874 case ICMPV6_ECHO_REPLY:
875 success = ping_rcv(skb);
876 break;
877
878 case ICMPV6_PKT_TOOBIG:
879 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
880 standard destination cache. Seems, only "advanced"
881 destination cache will allow to solve this problem
882 --ANK (980726)
883 */
884 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
885 goto discard_it;
886 hdr = icmp6_hdr(skb);
887
888 /* to notify */
889 /* fall through */
890 case ICMPV6_DEST_UNREACH:
891 case ICMPV6_TIME_EXCEED:
892 case ICMPV6_PARAMPROB:
893 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
894 break;
895
896 case NDISC_ROUTER_SOLICITATION:
897 case NDISC_ROUTER_ADVERTISEMENT:
898 case NDISC_NEIGHBOUR_SOLICITATION:
899 case NDISC_NEIGHBOUR_ADVERTISEMENT:
900 case NDISC_REDIRECT:
901 ndisc_rcv(skb);
902 break;
903
904 case ICMPV6_MGM_QUERY:
905 igmp6_event_query(skb);
906 break;
907
908 case ICMPV6_MGM_REPORT:
909 igmp6_event_report(skb);
910 break;
911
912 case ICMPV6_MGM_REDUCTION:
913 case ICMPV6_NI_QUERY:
914 case ICMPV6_NI_REPLY:
915 case ICMPV6_MLD2_REPORT:
916 case ICMPV6_DHAAD_REQUEST:
917 case ICMPV6_DHAAD_REPLY:
918 case ICMPV6_MOBILE_PREFIX_SOL:
919 case ICMPV6_MOBILE_PREFIX_ADV:
920 break;
921
922 default:
923 /* informational */
924 if (type & ICMPV6_INFOMSG_MASK)
925 break;
926
927 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
928 saddr, daddr);
929
930 /*
931 * error of unknown type.
932 * must pass to upper level
933 */
934
935 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
936 }
937
938 /* until the v6 path can be better sorted assume failure and
939 * preserve the status quo behaviour for the rest of the paths to here
940 */
941 if (success)
942 consume_skb(skb);
943 else
944 kfree_skb(skb);
945
946 return 0;
947
948csum_error:
949 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
950discard_it:
951 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
952drop_no_count:
953 kfree_skb(skb);
954 return 0;
955}
956
957void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
958 u8 type,
959 const struct in6_addr *saddr,
960 const struct in6_addr *daddr,
961 int oif)
962{
963 memset(fl6, 0, sizeof(*fl6));
964 fl6->saddr = *saddr;
965 fl6->daddr = *daddr;
966 fl6->flowi6_proto = IPPROTO_ICMPV6;
967 fl6->fl6_icmp_type = type;
968 fl6->fl6_icmp_code = 0;
969 fl6->flowi6_oif = oif;
970 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
971}
972
973static void __net_exit icmpv6_sk_exit(struct net *net)
974{
975 int i;
976
977 for_each_possible_cpu(i)
978 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv6.icmp_sk, i));
979 free_percpu(net->ipv6.icmp_sk);
980}
981
982static int __net_init icmpv6_sk_init(struct net *net)
983{
984 struct sock *sk;
985 int err, i;
986
987 net->ipv6.icmp_sk = alloc_percpu(struct sock *);
988 if (!net->ipv6.icmp_sk)
989 return -ENOMEM;
990
991 for_each_possible_cpu(i) {
992 err = inet_ctl_sock_create(&sk, PF_INET6,
993 SOCK_RAW, IPPROTO_ICMPV6, net);
994 if (err < 0) {
995 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
996 err);
997 goto fail;
998 }
999
1000 *per_cpu_ptr(net->ipv6.icmp_sk, i) = sk;
1001
1002 /* Enough space for 2 64K ICMP packets, including
1003 * sk_buff struct overhead.
1004 */
1005 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1006 }
1007 return 0;
1008
1009 fail:
1010 icmpv6_sk_exit(net);
1011 return err;
1012}
1013
1014static struct pernet_operations icmpv6_sk_ops = {
1015 .init = icmpv6_sk_init,
1016 .exit = icmpv6_sk_exit,
1017};
1018
1019int __init icmpv6_init(void)
1020{
1021 int err;
1022
1023 err = register_pernet_subsys(&icmpv6_sk_ops);
1024 if (err < 0)
1025 return err;
1026
1027 err = -EAGAIN;
1028 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1029 goto fail;
1030
1031 err = inet6_register_icmp_sender(icmp6_send);
1032 if (err)
1033 goto sender_reg_err;
1034 return 0;
1035
1036sender_reg_err:
1037 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1038fail:
1039 pr_err("Failed to register ICMP6 protocol\n");
1040 unregister_pernet_subsys(&icmpv6_sk_ops);
1041 return err;
1042}
1043
1044void icmpv6_cleanup(void)
1045{
1046 inet6_unregister_icmp_sender(icmp6_send);
1047 unregister_pernet_subsys(&icmpv6_sk_ops);
1048 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1049}
1050
1051
1052static const struct icmp6_err {
1053 int err;
1054 int fatal;
1055} tab_unreach[] = {
1056 { /* NOROUTE */
1057 .err = ENETUNREACH,
1058 .fatal = 0,
1059 },
1060 { /* ADM_PROHIBITED */
1061 .err = EACCES,
1062 .fatal = 1,
1063 },
1064 { /* Was NOT_NEIGHBOUR, now reserved */
1065 .err = EHOSTUNREACH,
1066 .fatal = 0,
1067 },
1068 { /* ADDR_UNREACH */
1069 .err = EHOSTUNREACH,
1070 .fatal = 0,
1071 },
1072 { /* PORT_UNREACH */
1073 .err = ECONNREFUSED,
1074 .fatal = 1,
1075 },
1076 { /* POLICY_FAIL */
1077 .err = EACCES,
1078 .fatal = 1,
1079 },
1080 { /* REJECT_ROUTE */
1081 .err = EACCES,
1082 .fatal = 1,
1083 },
1084};
1085
1086int icmpv6_err_convert(u8 type, u8 code, int *err)
1087{
1088 int fatal = 0;
1089
1090 *err = EPROTO;
1091
1092 switch (type) {
1093 case ICMPV6_DEST_UNREACH:
1094 fatal = 1;
1095 if (code < ARRAY_SIZE(tab_unreach)) {
1096 *err = tab_unreach[code].err;
1097 fatal = tab_unreach[code].fatal;
1098 }
1099 break;
1100
1101 case ICMPV6_PKT_TOOBIG:
1102 *err = EMSGSIZE;
1103 break;
1104
1105 case ICMPV6_PARAMPROB:
1106 *err = EPROTO;
1107 fatal = 1;
1108 break;
1109
1110 case ICMPV6_TIME_EXCEED:
1111 *err = EHOSTUNREACH;
1112 break;
1113 }
1114
1115 return fatal;
1116}
1117EXPORT_SYMBOL(icmpv6_err_convert);
1118
1119#ifdef CONFIG_SYSCTL
1120static struct ctl_table ipv6_icmp_table_template[] = {
1121 {
1122 .procname = "ratelimit",
1123 .data = &init_net.ipv6.sysctl.icmpv6_time,
1124 .maxlen = sizeof(int),
1125 .mode = 0644,
1126 .proc_handler = proc_dointvec_ms_jiffies,
1127 },
1128 {
1129 .procname = "echo_ignore_all",
1130 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1131 .maxlen = sizeof(int),
1132 .mode = 0644,
1133 .proc_handler = proc_dointvec,
1134 },
1135 {
1136 .procname = "echo_ignore_multicast",
1137 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1138 .maxlen = sizeof(int),
1139 .mode = 0644,
1140 .proc_handler = proc_dointvec,
1141 },
1142 {
1143 .procname = "echo_ignore_anycast",
1144 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1145 .maxlen = sizeof(int),
1146 .mode = 0644,
1147 .proc_handler = proc_dointvec,
1148 },
1149 {
1150 .procname = "ratemask",
1151 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1152 .maxlen = ICMPV6_MSG_MAX + 1,
1153 .mode = 0644,
1154 .proc_handler = proc_do_large_bitmap,
1155 },
1156 { },
1157};
1158
1159struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1160{
1161 struct ctl_table *table;
1162
1163 table = kmemdup(ipv6_icmp_table_template,
1164 sizeof(ipv6_icmp_table_template),
1165 GFP_KERNEL);
1166
1167 if (table) {
1168 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1169 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1170 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1171 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1172 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1173 }
1174 return table;
1175}
1176#endif