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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(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 return false;
187}
188
189/*
190 * Check the ICMP output rate limit
191 */
192static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
193 struct flowi6 *fl6)
194{
195 struct net *net = sock_net(sk);
196 struct dst_entry *dst;
197 bool res = false;
198
199 if (icmpv6_mask_allow(net, type))
200 return true;
201
202 /*
203 * Look up the output route.
204 * XXX: perhaps the expire for routing entries cloned by
205 * this lookup should be more aggressive (not longer than timeout).
206 */
207 dst = ip6_route_output(net, sk, fl6);
208 if (dst->error) {
209 IP6_INC_STATS(net, ip6_dst_idev(dst),
210 IPSTATS_MIB_OUTNOROUTES);
211 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
212 res = true;
213 } else {
214 struct rt6_info *rt = (struct rt6_info *)dst;
215 int tmo = net->ipv6.sysctl.icmpv6_time;
216 struct inet_peer *peer;
217
218 /* Give more bandwidth to wider prefixes. */
219 if (rt->rt6i_dst.plen < 128)
220 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
221
222 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
223 res = inet_peer_xrlim_allow(peer, tmo);
224 if (peer)
225 inet_putpeer(peer);
226 }
227 dst_release(dst);
228 return res;
229}
230
231static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type,
232 struct flowi6 *fl6)
233{
234 struct net *net = sock_net(sk);
235 struct dst_entry *dst;
236 bool res = false;
237
238 dst = ip6_route_output(net, sk, fl6);
239 if (!dst->error) {
240 struct rt6_info *rt = (struct rt6_info *)dst;
241 struct in6_addr prefsrc;
242
243 rt6_get_prefsrc(rt, &prefsrc);
244 res = !ipv6_addr_any(&prefsrc);
245 }
246 dst_release(dst);
247 return res;
248}
249
250/*
251 * an inline helper for the "simple" if statement below
252 * checks if parameter problem report is caused by an
253 * unrecognized IPv6 option that has the Option Type
254 * highest-order two bits set to 10
255 */
256
257static bool opt_unrec(struct sk_buff *skb, __u32 offset)
258{
259 u8 _optval, *op;
260
261 offset += skb_network_offset(skb);
262 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
263 if (!op)
264 return true;
265 return (*op & 0xC0) == 0x80;
266}
267
268void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
269 struct icmp6hdr *thdr, int len)
270{
271 struct sk_buff *skb;
272 struct icmp6hdr *icmp6h;
273
274 skb = skb_peek(&sk->sk_write_queue);
275 if (!skb)
276 return;
277
278 icmp6h = icmp6_hdr(skb);
279 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
280 icmp6h->icmp6_cksum = 0;
281
282 if (skb_queue_len(&sk->sk_write_queue) == 1) {
283 skb->csum = csum_partial(icmp6h,
284 sizeof(struct icmp6hdr), skb->csum);
285 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
286 &fl6->daddr,
287 len, fl6->flowi6_proto,
288 skb->csum);
289 } else {
290 __wsum tmp_csum = 0;
291
292 skb_queue_walk(&sk->sk_write_queue, skb) {
293 tmp_csum = csum_add(tmp_csum, skb->csum);
294 }
295
296 tmp_csum = csum_partial(icmp6h,
297 sizeof(struct icmp6hdr), tmp_csum);
298 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
299 &fl6->daddr,
300 len, fl6->flowi6_proto,
301 tmp_csum);
302 }
303 ip6_push_pending_frames(sk);
304}
305
306struct icmpv6_msg {
307 struct sk_buff *skb;
308 int offset;
309 uint8_t type;
310};
311
312static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
313{
314 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
315 struct sk_buff *org_skb = msg->skb;
316 __wsum csum;
317
318 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
319 to, len);
320 skb->csum = csum_block_add(skb->csum, csum, odd);
321 if (!(msg->type & ICMPV6_INFOMSG_MASK))
322 nf_ct_attach(skb, org_skb);
323 return 0;
324}
325
326#if IS_ENABLED(CONFIG_IPV6_MIP6)
327static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt)
328{
329 struct ipv6hdr *iph = ipv6_hdr(skb);
330 struct ipv6_destopt_hao *hao;
331 struct in6_addr tmp;
332 int off;
333
334 if (opt->dsthao) {
335 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
336 if (likely(off >= 0)) {
337 hao = (struct ipv6_destopt_hao *)
338 (skb_network_header(skb) + off);
339 tmp = iph->saddr;
340 iph->saddr = hao->addr;
341 hao->addr = tmp;
342 }
343 }
344}
345#else
346static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {}
347#endif
348
349static struct dst_entry *icmpv6_route_lookup(struct net *net,
350 struct sk_buff *skb,
351 struct sock *sk,
352 struct flowi6 *fl6)
353{
354 struct dst_entry *dst, *dst2;
355 struct flowi6 fl2;
356 int err;
357
358 err = ip6_dst_lookup(net, sk, &dst, fl6);
359 if (err)
360 return ERR_PTR(err);
361
362 /*
363 * We won't send icmp if the destination is known
364 * anycast.
365 */
366 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
367 net_dbg_ratelimited("icmp6_send: acast source\n");
368 dst_release(dst);
369 return ERR_PTR(-EINVAL);
370 }
371
372 /* No need to clone since we're just using its address. */
373 dst2 = dst;
374
375 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
376 if (!IS_ERR(dst)) {
377 if (dst != dst2)
378 return dst;
379 } else {
380 if (PTR_ERR(dst) == -EPERM)
381 dst = NULL;
382 else
383 return dst;
384 }
385
386 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
387 if (err)
388 goto relookup_failed;
389
390 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
391 if (err)
392 goto relookup_failed;
393
394 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
395 if (!IS_ERR(dst2)) {
396 dst_release(dst);
397 dst = dst2;
398 } else {
399 err = PTR_ERR(dst2);
400 if (err == -EPERM) {
401 dst_release(dst);
402 return dst2;
403 } else
404 goto relookup_failed;
405 }
406
407relookup_failed:
408 if (dst)
409 return dst;
410 return ERR_PTR(err);
411}
412
413static struct net_device *icmp6_dev(const struct sk_buff *skb)
414{
415 struct net_device *dev = skb->dev;
416
417 /* for local traffic to local address, skb dev is the loopback
418 * device. Check if there is a dst attached to the skb and if so
419 * get the real device index. Same is needed for replies to a link
420 * local address on a device enslaved to an L3 master device
421 */
422 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
423 const struct rt6_info *rt6 = skb_rt6_info(skb);
424
425 if (rt6)
426 dev = rt6->rt6i_idev->dev;
427 }
428
429 return dev;
430}
431
432static int icmp6_iif(const struct sk_buff *skb)
433{
434 return icmp6_dev(skb)->ifindex;
435}
436
437/*
438 * Send an ICMP message in response to a packet in error
439 */
440void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
441 const struct in6_addr *force_saddr,
442 const struct inet6_skb_parm *parm)
443{
444 struct inet6_dev *idev = NULL;
445 struct ipv6hdr *hdr = ipv6_hdr(skb);
446 struct sock *sk;
447 struct net *net;
448 struct ipv6_pinfo *np;
449 const struct in6_addr *saddr = NULL;
450 struct dst_entry *dst;
451 struct icmp6hdr tmp_hdr;
452 struct flowi6 fl6;
453 struct icmpv6_msg msg;
454 struct ipcm6_cookie ipc6;
455 int iif = 0;
456 int addr_type = 0;
457 int len;
458 u32 mark;
459
460 if ((u8 *)hdr < skb->head ||
461 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
462 return;
463
464 if (!skb->dev)
465 return;
466 net = dev_net(skb->dev);
467 mark = IP6_REPLY_MARK(net, skb->mark);
468 /*
469 * Make sure we respect the rules
470 * i.e. RFC 1885 2.4(e)
471 * Rule (e.1) is enforced by not using icmp6_send
472 * in any code that processes icmp errors.
473 */
474 addr_type = ipv6_addr_type(&hdr->daddr);
475
476 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
477 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
478 saddr = &hdr->daddr;
479
480 /*
481 * Dest addr check
482 */
483
484 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
485 if (type != ICMPV6_PKT_TOOBIG &&
486 !(type == ICMPV6_PARAMPROB &&
487 code == ICMPV6_UNK_OPTION &&
488 (opt_unrec(skb, info))))
489 return;
490
491 saddr = NULL;
492 }
493
494 addr_type = ipv6_addr_type(&hdr->saddr);
495
496 /*
497 * Source addr check
498 */
499
500 if (__ipv6_addr_needs_scope_id(addr_type)) {
501 iif = icmp6_iif(skb);
502 } else {
503 /*
504 * The source device is used for looking up which routing table
505 * to use for sending an ICMP error.
506 */
507 iif = l3mdev_master_ifindex(skb->dev);
508 }
509
510 /*
511 * Must not send error if the source does not uniquely
512 * identify a single node (RFC2463 Section 2.4).
513 * We check unspecified / multicast addresses here,
514 * and anycast addresses will be checked later.
515 */
516 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
517 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
518 &hdr->saddr, &hdr->daddr);
519 return;
520 }
521
522 /*
523 * Never answer to a ICMP packet.
524 */
525 if (is_ineligible(skb)) {
526 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
527 &hdr->saddr, &hdr->daddr);
528 return;
529 }
530
531 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
532 local_bh_disable();
533
534 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
535 if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
536 goto out_bh_enable;
537
538 mip6_addr_swap(skb, parm);
539
540 sk = icmpv6_xmit_lock(net);
541 if (!sk)
542 goto out_bh_enable;
543
544 memset(&fl6, 0, sizeof(fl6));
545 fl6.flowi6_proto = IPPROTO_ICMPV6;
546 fl6.daddr = hdr->saddr;
547 if (force_saddr)
548 saddr = force_saddr;
549 if (saddr) {
550 fl6.saddr = *saddr;
551 } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) {
552 /* select a more meaningful saddr from input if */
553 struct net_device *in_netdev;
554
555 in_netdev = dev_get_by_index(net, parm->iif);
556 if (in_netdev) {
557 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
558 inet6_sk(sk)->srcprefs,
559 &fl6.saddr);
560 dev_put(in_netdev);
561 }
562 }
563 fl6.flowi6_mark = mark;
564 fl6.flowi6_oif = iif;
565 fl6.fl6_icmp_type = type;
566 fl6.fl6_icmp_code = code;
567 fl6.flowi6_uid = sock_net_uid(net, NULL);
568 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
569 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
570
571 np = inet6_sk(sk);
572
573 if (!icmpv6_xrlim_allow(sk, type, &fl6))
574 goto out;
575
576 tmp_hdr.icmp6_type = type;
577 tmp_hdr.icmp6_code = code;
578 tmp_hdr.icmp6_cksum = 0;
579 tmp_hdr.icmp6_pointer = htonl(info);
580
581 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
582 fl6.flowi6_oif = np->mcast_oif;
583 else if (!fl6.flowi6_oif)
584 fl6.flowi6_oif = np->ucast_oif;
585
586 ipcm6_init_sk(&ipc6, np);
587 ipc6.sockc.mark = mark;
588 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
589
590 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
591 if (IS_ERR(dst))
592 goto out;
593
594 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
595
596 msg.skb = skb;
597 msg.offset = skb_network_offset(skb);
598 msg.type = type;
599
600 len = skb->len - msg.offset;
601 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
602 if (len < 0) {
603 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
604 &hdr->saddr, &hdr->daddr);
605 goto out_dst_release;
606 }
607
608 rcu_read_lock();
609 idev = __in6_dev_get(skb->dev);
610
611 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
612 len + sizeof(struct icmp6hdr),
613 sizeof(struct icmp6hdr),
614 &ipc6, &fl6, (struct rt6_info *)dst,
615 MSG_DONTWAIT)) {
616 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
617 ip6_flush_pending_frames(sk);
618 } else {
619 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
620 len + sizeof(struct icmp6hdr));
621 }
622 rcu_read_unlock();
623out_dst_release:
624 dst_release(dst);
625out:
626 icmpv6_xmit_unlock(sk);
627out_bh_enable:
628 local_bh_enable();
629}
630EXPORT_SYMBOL(icmp6_send);
631
632/* Slightly more convenient version of icmp6_send with drop reasons.
633 */
634void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos,
635 enum skb_drop_reason reason)
636{
637 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
638 kfree_skb_reason(skb, reason);
639}
640
641/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
642 * if sufficient data bytes are available
643 * @nhs is the size of the tunnel header(s) :
644 * Either an IPv4 header for SIT encap
645 * an IPv4 header + GRE header for GRE encap
646 */
647int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
648 unsigned int data_len)
649{
650 struct in6_addr temp_saddr;
651 struct rt6_info *rt;
652 struct sk_buff *skb2;
653 u32 info = 0;
654
655 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
656 return 1;
657
658 /* RFC 4884 (partial) support for ICMP extensions */
659 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
660 data_len = 0;
661
662 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
663
664 if (!skb2)
665 return 1;
666
667 skb_dst_drop(skb2);
668 skb_pull(skb2, nhs);
669 skb_reset_network_header(skb2);
670
671 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
672 skb, 0);
673
674 if (rt && rt->dst.dev)
675 skb2->dev = rt->dst.dev;
676
677 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
678
679 if (data_len) {
680 /* RFC 4884 (partial) support :
681 * insert 0 padding at the end, before the extensions
682 */
683 __skb_push(skb2, nhs);
684 skb_reset_network_header(skb2);
685 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
686 memset(skb2->data + data_len - nhs, 0, nhs);
687 /* RFC 4884 4.5 : Length is measured in 64-bit words,
688 * and stored in reserved[0]
689 */
690 info = (data_len/8) << 24;
691 }
692 if (type == ICMP_TIME_EXCEEDED)
693 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
694 info, &temp_saddr, IP6CB(skb2));
695 else
696 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
697 info, &temp_saddr, IP6CB(skb2));
698 if (rt)
699 ip6_rt_put(rt);
700
701 kfree_skb(skb2);
702
703 return 0;
704}
705EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
706
707static void icmpv6_echo_reply(struct sk_buff *skb)
708{
709 struct net *net = dev_net(skb->dev);
710 struct sock *sk;
711 struct inet6_dev *idev;
712 struct ipv6_pinfo *np;
713 const struct in6_addr *saddr = NULL;
714 struct icmp6hdr *icmph = icmp6_hdr(skb);
715 struct icmp6hdr tmp_hdr;
716 struct flowi6 fl6;
717 struct icmpv6_msg msg;
718 struct dst_entry *dst;
719 struct ipcm6_cookie ipc6;
720 u32 mark = IP6_REPLY_MARK(net, skb->mark);
721 bool acast;
722 u8 type;
723
724 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
725 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
726 return;
727
728 saddr = &ipv6_hdr(skb)->daddr;
729
730 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
731 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
732 return;
733
734 if (!ipv6_unicast_destination(skb) &&
735 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
736 saddr = NULL;
737
738 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
739 type = ICMPV6_EXT_ECHO_REPLY;
740 else
741 type = ICMPV6_ECHO_REPLY;
742
743 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
744 tmp_hdr.icmp6_type = type;
745
746 memset(&fl6, 0, sizeof(fl6));
747 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
748 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
749
750 fl6.flowi6_proto = IPPROTO_ICMPV6;
751 fl6.daddr = ipv6_hdr(skb)->saddr;
752 if (saddr)
753 fl6.saddr = *saddr;
754 fl6.flowi6_oif = icmp6_iif(skb);
755 fl6.fl6_icmp_type = type;
756 fl6.flowi6_mark = mark;
757 fl6.flowi6_uid = sock_net_uid(net, NULL);
758 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
759
760 local_bh_disable();
761 sk = icmpv6_xmit_lock(net);
762 if (!sk)
763 goto out_bh_enable;
764 np = inet6_sk(sk);
765
766 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
767 fl6.flowi6_oif = np->mcast_oif;
768 else if (!fl6.flowi6_oif)
769 fl6.flowi6_oif = np->ucast_oif;
770
771 if (ip6_dst_lookup(net, sk, &dst, &fl6))
772 goto out;
773 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
774 if (IS_ERR(dst))
775 goto out;
776
777 /* Check the ratelimit */
778 if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
779 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
780 goto out_dst_release;
781
782 idev = __in6_dev_get(skb->dev);
783
784 msg.skb = skb;
785 msg.offset = 0;
786 msg.type = type;
787
788 ipcm6_init_sk(&ipc6, np);
789 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
790 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
791 ipc6.sockc.mark = mark;
792
793 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
794 if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr))
795 goto out_dst_release;
796
797 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
798 skb->len + sizeof(struct icmp6hdr),
799 sizeof(struct icmp6hdr), &ipc6, &fl6,
800 (struct rt6_info *)dst, MSG_DONTWAIT)) {
801 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
802 ip6_flush_pending_frames(sk);
803 } else {
804 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
805 skb->len + sizeof(struct icmp6hdr));
806 }
807out_dst_release:
808 dst_release(dst);
809out:
810 icmpv6_xmit_unlock(sk);
811out_bh_enable:
812 local_bh_enable();
813}
814
815void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
816{
817 struct inet6_skb_parm *opt = IP6CB(skb);
818 const struct inet6_protocol *ipprot;
819 int inner_offset;
820 __be16 frag_off;
821 u8 nexthdr;
822 struct net *net = dev_net(skb->dev);
823
824 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
825 goto out;
826
827 seg6_icmp_srh(skb, opt);
828
829 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
830 if (ipv6_ext_hdr(nexthdr)) {
831 /* now skip over extension headers */
832 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
833 &nexthdr, &frag_off);
834 if (inner_offset < 0)
835 goto out;
836 } else {
837 inner_offset = sizeof(struct ipv6hdr);
838 }
839
840 /* Checkin header including 8 bytes of inner protocol header. */
841 if (!pskb_may_pull(skb, inner_offset+8))
842 goto out;
843
844 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
845 Without this we will not able f.e. to make source routed
846 pmtu discovery.
847 Corresponding argument (opt) to notifiers is already added.
848 --ANK (980726)
849 */
850
851 ipprot = rcu_dereference(inet6_protos[nexthdr]);
852 if (ipprot && ipprot->err_handler)
853 ipprot->err_handler(skb, opt, type, code, inner_offset, info);
854
855 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
856 return;
857
858out:
859 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
860}
861
862/*
863 * Handle icmp messages
864 */
865
866static int icmpv6_rcv(struct sk_buff *skb)
867{
868 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
869 struct net *net = dev_net(skb->dev);
870 struct net_device *dev = icmp6_dev(skb);
871 struct inet6_dev *idev = __in6_dev_get(dev);
872 const struct in6_addr *saddr, *daddr;
873 struct icmp6hdr *hdr;
874 u8 type;
875
876 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
877 struct sec_path *sp = skb_sec_path(skb);
878 int nh;
879
880 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
881 XFRM_STATE_ICMP)) {
882 reason = SKB_DROP_REASON_XFRM_POLICY;
883 goto drop_no_count;
884 }
885
886 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
887 goto drop_no_count;
888
889 nh = skb_network_offset(skb);
890 skb_set_network_header(skb, sizeof(*hdr));
891
892 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN,
893 skb)) {
894 reason = SKB_DROP_REASON_XFRM_POLICY;
895 goto drop_no_count;
896 }
897
898 skb_set_network_header(skb, nh);
899 }
900
901 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
902
903 saddr = &ipv6_hdr(skb)->saddr;
904 daddr = &ipv6_hdr(skb)->daddr;
905
906 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
907 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
908 saddr, daddr);
909 goto csum_error;
910 }
911
912 if (!pskb_pull(skb, sizeof(*hdr)))
913 goto discard_it;
914
915 hdr = icmp6_hdr(skb);
916
917 type = hdr->icmp6_type;
918
919 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
920
921 switch (type) {
922 case ICMPV6_ECHO_REQUEST:
923 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
924 icmpv6_echo_reply(skb);
925 break;
926 case ICMPV6_EXT_ECHO_REQUEST:
927 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all &&
928 READ_ONCE(net->ipv4.sysctl_icmp_echo_enable_probe))
929 icmpv6_echo_reply(skb);
930 break;
931
932 case ICMPV6_ECHO_REPLY:
933 reason = ping_rcv(skb);
934 break;
935
936 case ICMPV6_EXT_ECHO_REPLY:
937 reason = ping_rcv(skb);
938 break;
939
940 case ICMPV6_PKT_TOOBIG:
941 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
942 standard destination cache. Seems, only "advanced"
943 destination cache will allow to solve this problem
944 --ANK (980726)
945 */
946 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
947 goto discard_it;
948 hdr = icmp6_hdr(skb);
949
950 /* to notify */
951 fallthrough;
952 case ICMPV6_DEST_UNREACH:
953 case ICMPV6_TIME_EXCEED:
954 case ICMPV6_PARAMPROB:
955 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
956 break;
957
958 case NDISC_ROUTER_SOLICITATION:
959 case NDISC_ROUTER_ADVERTISEMENT:
960 case NDISC_NEIGHBOUR_SOLICITATION:
961 case NDISC_NEIGHBOUR_ADVERTISEMENT:
962 case NDISC_REDIRECT:
963 ndisc_rcv(skb);
964 break;
965
966 case ICMPV6_MGM_QUERY:
967 igmp6_event_query(skb);
968 return 0;
969
970 case ICMPV6_MGM_REPORT:
971 igmp6_event_report(skb);
972 return 0;
973
974 case ICMPV6_MGM_REDUCTION:
975 case ICMPV6_NI_QUERY:
976 case ICMPV6_NI_REPLY:
977 case ICMPV6_MLD2_REPORT:
978 case ICMPV6_DHAAD_REQUEST:
979 case ICMPV6_DHAAD_REPLY:
980 case ICMPV6_MOBILE_PREFIX_SOL:
981 case ICMPV6_MOBILE_PREFIX_ADV:
982 break;
983
984 default:
985 /* informational */
986 if (type & ICMPV6_INFOMSG_MASK)
987 break;
988
989 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
990 saddr, daddr);
991
992 /*
993 * error of unknown type.
994 * must pass to upper level
995 */
996
997 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
998 }
999
1000 /* until the v6 path can be better sorted assume failure and
1001 * preserve the status quo behaviour for the rest of the paths to here
1002 */
1003 if (reason)
1004 kfree_skb_reason(skb, reason);
1005 else
1006 consume_skb(skb);
1007
1008 return 0;
1009
1010csum_error:
1011 reason = SKB_DROP_REASON_ICMP_CSUM;
1012 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
1013discard_it:
1014 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
1015drop_no_count:
1016 kfree_skb_reason(skb, reason);
1017 return 0;
1018}
1019
1020void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
1021 u8 type,
1022 const struct in6_addr *saddr,
1023 const struct in6_addr *daddr,
1024 int oif)
1025{
1026 memset(fl6, 0, sizeof(*fl6));
1027 fl6->saddr = *saddr;
1028 fl6->daddr = *daddr;
1029 fl6->flowi6_proto = IPPROTO_ICMPV6;
1030 fl6->fl6_icmp_type = type;
1031 fl6->fl6_icmp_code = 0;
1032 fl6->flowi6_oif = oif;
1033 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1034}
1035
1036int __init icmpv6_init(void)
1037{
1038 struct sock *sk;
1039 int err, i;
1040
1041 for_each_possible_cpu(i) {
1042 err = inet_ctl_sock_create(&sk, PF_INET6,
1043 SOCK_RAW, IPPROTO_ICMPV6, &init_net);
1044 if (err < 0) {
1045 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
1046 err);
1047 return err;
1048 }
1049
1050 per_cpu(ipv6_icmp_sk, i) = sk;
1051
1052 /* Enough space for 2 64K ICMP packets, including
1053 * sk_buff struct overhead.
1054 */
1055 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1056 }
1057
1058 err = -EAGAIN;
1059 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1060 goto fail;
1061
1062 err = inet6_register_icmp_sender(icmp6_send);
1063 if (err)
1064 goto sender_reg_err;
1065 return 0;
1066
1067sender_reg_err:
1068 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1069fail:
1070 pr_err("Failed to register ICMP6 protocol\n");
1071 return err;
1072}
1073
1074void icmpv6_cleanup(void)
1075{
1076 inet6_unregister_icmp_sender(icmp6_send);
1077 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1078}
1079
1080
1081static const struct icmp6_err {
1082 int err;
1083 int fatal;
1084} tab_unreach[] = {
1085 { /* NOROUTE */
1086 .err = ENETUNREACH,
1087 .fatal = 0,
1088 },
1089 { /* ADM_PROHIBITED */
1090 .err = EACCES,
1091 .fatal = 1,
1092 },
1093 { /* Was NOT_NEIGHBOUR, now reserved */
1094 .err = EHOSTUNREACH,
1095 .fatal = 0,
1096 },
1097 { /* ADDR_UNREACH */
1098 .err = EHOSTUNREACH,
1099 .fatal = 0,
1100 },
1101 { /* PORT_UNREACH */
1102 .err = ECONNREFUSED,
1103 .fatal = 1,
1104 },
1105 { /* POLICY_FAIL */
1106 .err = EACCES,
1107 .fatal = 1,
1108 },
1109 { /* REJECT_ROUTE */
1110 .err = EACCES,
1111 .fatal = 1,
1112 },
1113};
1114
1115int icmpv6_err_convert(u8 type, u8 code, int *err)
1116{
1117 int fatal = 0;
1118
1119 *err = EPROTO;
1120
1121 switch (type) {
1122 case ICMPV6_DEST_UNREACH:
1123 fatal = 1;
1124 if (code < ARRAY_SIZE(tab_unreach)) {
1125 *err = tab_unreach[code].err;
1126 fatal = tab_unreach[code].fatal;
1127 }
1128 break;
1129
1130 case ICMPV6_PKT_TOOBIG:
1131 *err = EMSGSIZE;
1132 break;
1133
1134 case ICMPV6_PARAMPROB:
1135 *err = EPROTO;
1136 fatal = 1;
1137 break;
1138
1139 case ICMPV6_TIME_EXCEED:
1140 *err = EHOSTUNREACH;
1141 break;
1142 }
1143
1144 return fatal;
1145}
1146EXPORT_SYMBOL(icmpv6_err_convert);
1147
1148#ifdef CONFIG_SYSCTL
1149static struct ctl_table ipv6_icmp_table_template[] = {
1150 {
1151 .procname = "ratelimit",
1152 .data = &init_net.ipv6.sysctl.icmpv6_time,
1153 .maxlen = sizeof(int),
1154 .mode = 0644,
1155 .proc_handler = proc_dointvec_ms_jiffies,
1156 },
1157 {
1158 .procname = "echo_ignore_all",
1159 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1160 .maxlen = sizeof(u8),
1161 .mode = 0644,
1162 .proc_handler = proc_dou8vec_minmax,
1163 },
1164 {
1165 .procname = "echo_ignore_multicast",
1166 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1167 .maxlen = sizeof(u8),
1168 .mode = 0644,
1169 .proc_handler = proc_dou8vec_minmax,
1170 },
1171 {
1172 .procname = "echo_ignore_anycast",
1173 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1174 .maxlen = sizeof(u8),
1175 .mode = 0644,
1176 .proc_handler = proc_dou8vec_minmax,
1177 },
1178 {
1179 .procname = "ratemask",
1180 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1181 .maxlen = ICMPV6_MSG_MAX + 1,
1182 .mode = 0644,
1183 .proc_handler = proc_do_large_bitmap,
1184 },
1185 { },
1186};
1187
1188struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1189{
1190 struct ctl_table *table;
1191
1192 table = kmemdup(ipv6_icmp_table_template,
1193 sizeof(ipv6_icmp_table_template),
1194 GFP_KERNEL);
1195
1196 if (table) {
1197 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1198 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1199 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1200 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1201 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1202 }
1203 return table;
1204}
1205#endif
1/*
2 * Internet Control Message Protocol (ICMPv6)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on net/ipv4/icmp.c
9 *
10 * RFC 1885
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18/*
19 * Changes:
20 *
21 * Andi Kleen : exception handling
22 * Andi Kleen add rate limits. never reply to a icmp.
23 * add more length checks and other fixes.
24 * yoshfuji : ensure to sent parameter problem for
25 * fragments.
26 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
27 * Randy Dunlap and
28 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
29 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
30 */
31
32#define pr_fmt(fmt) "IPv6: " fmt
33
34#include <linux/module.h>
35#include <linux/errno.h>
36#include <linux/types.h>
37#include <linux/socket.h>
38#include <linux/in.h>
39#include <linux/kernel.h>
40#include <linux/sockios.h>
41#include <linux/net.h>
42#include <linux/skbuff.h>
43#include <linux/init.h>
44#include <linux/netfilter.h>
45#include <linux/slab.h>
46
47#ifdef CONFIG_SYSCTL
48#include <linux/sysctl.h>
49#endif
50
51#include <linux/inet.h>
52#include <linux/netdevice.h>
53#include <linux/icmpv6.h>
54
55#include <net/ip.h>
56#include <net/sock.h>
57
58#include <net/ipv6.h>
59#include <net/ip6_checksum.h>
60#include <net/ping.h>
61#include <net/protocol.h>
62#include <net/raw.h>
63#include <net/rawv6.h>
64#include <net/transp_v6.h>
65#include <net/ip6_route.h>
66#include <net/addrconf.h>
67#include <net/icmp.h>
68#include <net/xfrm.h>
69#include <net/inet_common.h>
70#include <net/dsfield.h>
71
72#include <asm/uaccess.h>
73
74/*
75 * The ICMP socket(s). This is the most convenient way to flow control
76 * our ICMP output as well as maintain a clean interface throughout
77 * all layers. All Socketless IP sends will soon be gone.
78 *
79 * On SMP we have one ICMP socket per-cpu.
80 */
81static inline struct sock *icmpv6_sk(struct net *net)
82{
83 return net->ipv6.icmp_sk[smp_processor_id()];
84}
85
86static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
87 u8 type, u8 code, int offset, __be32 info)
88{
89 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
90 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
91 struct net *net = dev_net(skb->dev);
92
93 if (type == ICMPV6_PKT_TOOBIG)
94 ip6_update_pmtu(skb, net, info, 0, 0);
95 else if (type == NDISC_REDIRECT)
96 ip6_redirect(skb, net, skb->dev->ifindex, 0);
97
98 if (!(type & ICMPV6_INFOMSG_MASK))
99 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
100 ping_err(skb, offset, info);
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
111static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
112{
113 struct sock *sk;
114
115 local_bh_disable();
116
117 sk = icmpv6_sk(net);
118 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
119 /* This can happen if the output path (f.e. SIT or
120 * ip6ip6 tunnel) signals dst_link_failure() for an
121 * outgoing ICMP6 packet.
122 */
123 local_bh_enable();
124 return NULL;
125 }
126 return sk;
127}
128
129static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
130{
131 spin_unlock_bh(&sk->sk_lock.slock);
132}
133
134/*
135 * Figure out, may we reply to this packet with icmp error.
136 *
137 * We do not reply, if:
138 * - it was icmp error message.
139 * - it is truncated, so that it is known, that protocol is ICMPV6
140 * (i.e. in the middle of some exthdr)
141 *
142 * --ANK (980726)
143 */
144
145static bool is_ineligible(const struct sk_buff *skb)
146{
147 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
148 int len = skb->len - ptr;
149 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
150 __be16 frag_off;
151
152 if (len < 0)
153 return true;
154
155 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
156 if (ptr < 0)
157 return false;
158 if (nexthdr == IPPROTO_ICMPV6) {
159 u8 _type, *tp;
160 tp = skb_header_pointer(skb,
161 ptr+offsetof(struct icmp6hdr, icmp6_type),
162 sizeof(_type), &_type);
163 if (tp == NULL ||
164 !(*tp & ICMPV6_INFOMSG_MASK))
165 return true;
166 }
167 return false;
168}
169
170/*
171 * Check the ICMP output rate limit
172 */
173static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
174 struct flowi6 *fl6)
175{
176 struct dst_entry *dst;
177 struct net *net = sock_net(sk);
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 struct inet_peer *peer;
203
204 /* Give more bandwidth to wider prefixes. */
205 if (rt->rt6i_dst.plen < 128)
206 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
207
208 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
209 res = inet_peer_xrlim_allow(peer, tmo);
210 if (peer)
211 inet_putpeer(peer);
212 }
213 dst_release(dst);
214 return res;
215}
216
217/*
218 * an inline helper for the "simple" if statement below
219 * checks if parameter problem report is caused by an
220 * unrecognized IPv6 option that has the Option Type
221 * highest-order two bits set to 10
222 */
223
224static bool opt_unrec(struct sk_buff *skb, __u32 offset)
225{
226 u8 _optval, *op;
227
228 offset += skb_network_offset(skb);
229 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
230 if (op == NULL)
231 return true;
232 return (*op & 0xC0) == 0x80;
233}
234
235int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
236 struct icmp6hdr *thdr, int len)
237{
238 struct sk_buff *skb;
239 struct icmp6hdr *icmp6h;
240 int err = 0;
241
242 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
243 goto out;
244
245 icmp6h = icmp6_hdr(skb);
246 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
247 icmp6h->icmp6_cksum = 0;
248
249 if (skb_queue_len(&sk->sk_write_queue) == 1) {
250 skb->csum = csum_partial(icmp6h,
251 sizeof(struct icmp6hdr), skb->csum);
252 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
253 &fl6->daddr,
254 len, fl6->flowi6_proto,
255 skb->csum);
256 } else {
257 __wsum tmp_csum = 0;
258
259 skb_queue_walk(&sk->sk_write_queue, skb) {
260 tmp_csum = csum_add(tmp_csum, skb->csum);
261 }
262
263 tmp_csum = csum_partial(icmp6h,
264 sizeof(struct icmp6hdr), tmp_csum);
265 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
266 &fl6->daddr,
267 len, fl6->flowi6_proto,
268 tmp_csum);
269 }
270 ip6_push_pending_frames(sk);
271out:
272 return err;
273}
274
275struct icmpv6_msg {
276 struct sk_buff *skb;
277 int offset;
278 uint8_t type;
279};
280
281static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
282{
283 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
284 struct sk_buff *org_skb = msg->skb;
285 __wsum csum = 0;
286
287 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
288 to, len, csum);
289 skb->csum = csum_block_add(skb->csum, csum, odd);
290 if (!(msg->type & ICMPV6_INFOMSG_MASK))
291 nf_ct_attach(skb, org_skb);
292 return 0;
293}
294
295#if IS_ENABLED(CONFIG_IPV6_MIP6)
296static void mip6_addr_swap(struct sk_buff *skb)
297{
298 struct ipv6hdr *iph = ipv6_hdr(skb);
299 struct inet6_skb_parm *opt = IP6CB(skb);
300 struct ipv6_destopt_hao *hao;
301 struct in6_addr tmp;
302 int off;
303
304 if (opt->dsthao) {
305 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
306 if (likely(off >= 0)) {
307 hao = (struct ipv6_destopt_hao *)
308 (skb_network_header(skb) + off);
309 tmp = iph->saddr;
310 iph->saddr = hao->addr;
311 hao->addr = tmp;
312 }
313 }
314}
315#else
316static inline void mip6_addr_swap(struct sk_buff *skb) {}
317#endif
318
319static struct dst_entry *icmpv6_route_lookup(struct net *net,
320 struct sk_buff *skb,
321 struct sock *sk,
322 struct flowi6 *fl6)
323{
324 struct dst_entry *dst, *dst2;
325 struct flowi6 fl2;
326 int err;
327
328 err = ip6_dst_lookup(sk, &dst, fl6);
329 if (err)
330 return ERR_PTR(err);
331
332 /*
333 * We won't send icmp if the destination is known
334 * anycast.
335 */
336 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) {
337 LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: acast source\n");
338 dst_release(dst);
339 return ERR_PTR(-EINVAL);
340 }
341
342 /* No need to clone since we're just using its address. */
343 dst2 = dst;
344
345 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
346 if (!IS_ERR(dst)) {
347 if (dst != dst2)
348 return dst;
349 } else {
350 if (PTR_ERR(dst) == -EPERM)
351 dst = NULL;
352 else
353 return dst;
354 }
355
356 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
357 if (err)
358 goto relookup_failed;
359
360 err = ip6_dst_lookup(sk, &dst2, &fl2);
361 if (err)
362 goto relookup_failed;
363
364 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
365 if (!IS_ERR(dst2)) {
366 dst_release(dst);
367 dst = dst2;
368 } else {
369 err = PTR_ERR(dst2);
370 if (err == -EPERM) {
371 dst_release(dst);
372 return dst2;
373 } else
374 goto relookup_failed;
375 }
376
377relookup_failed:
378 if (dst)
379 return dst;
380 return ERR_PTR(err);
381}
382
383/*
384 * Send an ICMP message in response to a packet in error
385 */
386static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
387{
388 struct net *net = dev_net(skb->dev);
389 struct inet6_dev *idev = NULL;
390 struct ipv6hdr *hdr = ipv6_hdr(skb);
391 struct sock *sk;
392 struct ipv6_pinfo *np;
393 const struct in6_addr *saddr = NULL;
394 struct dst_entry *dst;
395 struct icmp6hdr tmp_hdr;
396 struct flowi6 fl6;
397 struct icmpv6_msg msg;
398 int iif = 0;
399 int addr_type = 0;
400 int len;
401 int hlimit;
402 int err = 0;
403
404 if ((u8 *)hdr < skb->head ||
405 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
406 return;
407
408 /*
409 * Make sure we respect the rules
410 * i.e. RFC 1885 2.4(e)
411 * Rule (e.1) is enforced by not using icmp6_send
412 * in any code that processes icmp errors.
413 */
414 addr_type = ipv6_addr_type(&hdr->daddr);
415
416 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
417 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
418 saddr = &hdr->daddr;
419
420 /*
421 * Dest addr check
422 */
423
424 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) {
425 if (type != ICMPV6_PKT_TOOBIG &&
426 !(type == ICMPV6_PARAMPROB &&
427 code == ICMPV6_UNK_OPTION &&
428 (opt_unrec(skb, info))))
429 return;
430
431 saddr = NULL;
432 }
433
434 addr_type = ipv6_addr_type(&hdr->saddr);
435
436 /*
437 * Source addr check
438 */
439
440 if (__ipv6_addr_needs_scope_id(addr_type))
441 iif = skb->dev->ifindex;
442
443 /*
444 * Must not send error if the source does not uniquely
445 * identify a single node (RFC2463 Section 2.4).
446 * We check unspecified / multicast addresses here,
447 * and anycast addresses will be checked later.
448 */
449 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
450 LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: addr_any/mcast source\n");
451 return;
452 }
453
454 /*
455 * Never answer to a ICMP packet.
456 */
457 if (is_ineligible(skb)) {
458 LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: no reply to icmp error\n");
459 return;
460 }
461
462 mip6_addr_swap(skb);
463
464 memset(&fl6, 0, sizeof(fl6));
465 fl6.flowi6_proto = IPPROTO_ICMPV6;
466 fl6.daddr = hdr->saddr;
467 if (saddr)
468 fl6.saddr = *saddr;
469 fl6.flowi6_oif = iif;
470 fl6.fl6_icmp_type = type;
471 fl6.fl6_icmp_code = code;
472 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
473
474 sk = icmpv6_xmit_lock(net);
475 if (sk == NULL)
476 return;
477 np = inet6_sk(sk);
478
479 if (!icmpv6_xrlim_allow(sk, type, &fl6))
480 goto out;
481
482 tmp_hdr.icmp6_type = type;
483 tmp_hdr.icmp6_code = code;
484 tmp_hdr.icmp6_cksum = 0;
485 tmp_hdr.icmp6_pointer = htonl(info);
486
487 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
488 fl6.flowi6_oif = np->mcast_oif;
489 else if (!fl6.flowi6_oif)
490 fl6.flowi6_oif = np->ucast_oif;
491
492 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
493 if (IS_ERR(dst))
494 goto out;
495
496 if (ipv6_addr_is_multicast(&fl6.daddr))
497 hlimit = np->mcast_hops;
498 else
499 hlimit = np->hop_limit;
500 if (hlimit < 0)
501 hlimit = ip6_dst_hoplimit(dst);
502
503 msg.skb = skb;
504 msg.offset = skb_network_offset(skb);
505 msg.type = type;
506
507 len = skb->len - msg.offset;
508 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
509 if (len < 0) {
510 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n");
511 goto out_dst_release;
512 }
513
514 rcu_read_lock();
515 idev = __in6_dev_get(skb->dev);
516
517 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
518 len + sizeof(struct icmp6hdr),
519 sizeof(struct icmp6hdr), hlimit,
520 np->tclass, NULL, &fl6, (struct rt6_info *)dst,
521 MSG_DONTWAIT, np->dontfrag);
522 if (err) {
523 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
524 ip6_flush_pending_frames(sk);
525 } else {
526 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
527 len + sizeof(struct icmp6hdr));
528 }
529 rcu_read_unlock();
530out_dst_release:
531 dst_release(dst);
532out:
533 icmpv6_xmit_unlock(sk);
534}
535
536/* Slightly more convenient version of icmp6_send.
537 */
538void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
539{
540 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
541 kfree_skb(skb);
542}
543
544static void icmpv6_echo_reply(struct sk_buff *skb)
545{
546 struct net *net = dev_net(skb->dev);
547 struct sock *sk;
548 struct inet6_dev *idev;
549 struct ipv6_pinfo *np;
550 const struct in6_addr *saddr = NULL;
551 struct icmp6hdr *icmph = icmp6_hdr(skb);
552 struct icmp6hdr tmp_hdr;
553 struct flowi6 fl6;
554 struct icmpv6_msg msg;
555 struct dst_entry *dst;
556 int err = 0;
557 int hlimit;
558 u8 tclass;
559
560 saddr = &ipv6_hdr(skb)->daddr;
561
562 if (!ipv6_unicast_destination(skb) &&
563 !(net->ipv6.sysctl.anycast_src_echo_reply &&
564 ipv6_anycast_destination(skb)))
565 saddr = NULL;
566
567 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
568 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
569
570 memset(&fl6, 0, sizeof(fl6));
571 fl6.flowi6_proto = IPPROTO_ICMPV6;
572 fl6.daddr = ipv6_hdr(skb)->saddr;
573 if (saddr)
574 fl6.saddr = *saddr;
575 fl6.flowi6_oif = skb->dev->ifindex;
576 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
577 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
578
579 sk = icmpv6_xmit_lock(net);
580 if (sk == NULL)
581 return;
582 np = inet6_sk(sk);
583
584 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
585 fl6.flowi6_oif = np->mcast_oif;
586 else if (!fl6.flowi6_oif)
587 fl6.flowi6_oif = np->ucast_oif;
588
589 err = ip6_dst_lookup(sk, &dst, &fl6);
590 if (err)
591 goto out;
592 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
593 if (IS_ERR(dst))
594 goto out;
595
596 if (ipv6_addr_is_multicast(&fl6.daddr))
597 hlimit = np->mcast_hops;
598 else
599 hlimit = np->hop_limit;
600 if (hlimit < 0)
601 hlimit = ip6_dst_hoplimit(dst);
602
603 idev = __in6_dev_get(skb->dev);
604
605 msg.skb = skb;
606 msg.offset = 0;
607 msg.type = ICMPV6_ECHO_REPLY;
608
609 tclass = ipv6_get_dsfield(ipv6_hdr(skb));
610 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
611 sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl6,
612 (struct rt6_info *)dst, MSG_DONTWAIT,
613 np->dontfrag);
614
615 if (err) {
616 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
617 ip6_flush_pending_frames(sk);
618 } else {
619 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
620 skb->len + sizeof(struct icmp6hdr));
621 }
622 dst_release(dst);
623out:
624 icmpv6_xmit_unlock(sk);
625}
626
627void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
628{
629 const struct inet6_protocol *ipprot;
630 int inner_offset;
631 __be16 frag_off;
632 u8 nexthdr;
633
634 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
635 return;
636
637 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
638 if (ipv6_ext_hdr(nexthdr)) {
639 /* now skip over extension headers */
640 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
641 &nexthdr, &frag_off);
642 if (inner_offset<0)
643 return;
644 } else {
645 inner_offset = sizeof(struct ipv6hdr);
646 }
647
648 /* Checkin header including 8 bytes of inner protocol header. */
649 if (!pskb_may_pull(skb, inner_offset+8))
650 return;
651
652 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
653 Without this we will not able f.e. to make source routed
654 pmtu discovery.
655 Corresponding argument (opt) to notifiers is already added.
656 --ANK (980726)
657 */
658
659 rcu_read_lock();
660 ipprot = rcu_dereference(inet6_protos[nexthdr]);
661 if (ipprot && ipprot->err_handler)
662 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
663 rcu_read_unlock();
664
665 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
666}
667
668/*
669 * Handle icmp messages
670 */
671
672static int icmpv6_rcv(struct sk_buff *skb)
673{
674 struct net_device *dev = skb->dev;
675 struct inet6_dev *idev = __in6_dev_get(dev);
676 const struct in6_addr *saddr, *daddr;
677 struct icmp6hdr *hdr;
678 u8 type;
679
680 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
681 struct sec_path *sp = skb_sec_path(skb);
682 int nh;
683
684 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
685 XFRM_STATE_ICMP))
686 goto drop_no_count;
687
688 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
689 goto drop_no_count;
690
691 nh = skb_network_offset(skb);
692 skb_set_network_header(skb, sizeof(*hdr));
693
694 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
695 goto drop_no_count;
696
697 skb_set_network_header(skb, nh);
698 }
699
700 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
701
702 saddr = &ipv6_hdr(skb)->saddr;
703 daddr = &ipv6_hdr(skb)->daddr;
704
705 /* Perform checksum. */
706 switch (skb->ip_summed) {
707 case CHECKSUM_COMPLETE:
708 if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
709 skb->csum))
710 break;
711 /* fall through */
712 case CHECKSUM_NONE:
713 skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len,
714 IPPROTO_ICMPV6, 0));
715 if (__skb_checksum_complete(skb)) {
716 LIMIT_NETDEBUG(KERN_DEBUG
717 "ICMPv6 checksum failed [%pI6c > %pI6c]\n",
718 saddr, daddr);
719 goto csum_error;
720 }
721 }
722
723 if (!pskb_pull(skb, sizeof(*hdr)))
724 goto discard_it;
725
726 hdr = icmp6_hdr(skb);
727
728 type = hdr->icmp6_type;
729
730 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
731
732 switch (type) {
733 case ICMPV6_ECHO_REQUEST:
734 icmpv6_echo_reply(skb);
735 break;
736
737 case ICMPV6_ECHO_REPLY:
738 ping_rcv(skb);
739 break;
740
741 case ICMPV6_PKT_TOOBIG:
742 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
743 standard destination cache. Seems, only "advanced"
744 destination cache will allow to solve this problem
745 --ANK (980726)
746 */
747 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
748 goto discard_it;
749 hdr = icmp6_hdr(skb);
750
751 /*
752 * Drop through to notify
753 */
754
755 case ICMPV6_DEST_UNREACH:
756 case ICMPV6_TIME_EXCEED:
757 case ICMPV6_PARAMPROB:
758 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
759 break;
760
761 case NDISC_ROUTER_SOLICITATION:
762 case NDISC_ROUTER_ADVERTISEMENT:
763 case NDISC_NEIGHBOUR_SOLICITATION:
764 case NDISC_NEIGHBOUR_ADVERTISEMENT:
765 case NDISC_REDIRECT:
766 ndisc_rcv(skb);
767 break;
768
769 case ICMPV6_MGM_QUERY:
770 igmp6_event_query(skb);
771 break;
772
773 case ICMPV6_MGM_REPORT:
774 igmp6_event_report(skb);
775 break;
776
777 case ICMPV6_MGM_REDUCTION:
778 case ICMPV6_NI_QUERY:
779 case ICMPV6_NI_REPLY:
780 case ICMPV6_MLD2_REPORT:
781 case ICMPV6_DHAAD_REQUEST:
782 case ICMPV6_DHAAD_REPLY:
783 case ICMPV6_MOBILE_PREFIX_SOL:
784 case ICMPV6_MOBILE_PREFIX_ADV:
785 break;
786
787 default:
788 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n");
789
790 /* informational */
791 if (type & ICMPV6_INFOMSG_MASK)
792 break;
793
794 /*
795 * error of unknown type.
796 * must pass to upper level
797 */
798
799 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
800 }
801
802 kfree_skb(skb);
803 return 0;
804
805csum_error:
806 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
807discard_it:
808 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
809drop_no_count:
810 kfree_skb(skb);
811 return 0;
812}
813
814void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
815 u8 type,
816 const struct in6_addr *saddr,
817 const struct in6_addr *daddr,
818 int oif)
819{
820 memset(fl6, 0, sizeof(*fl6));
821 fl6->saddr = *saddr;
822 fl6->daddr = *daddr;
823 fl6->flowi6_proto = IPPROTO_ICMPV6;
824 fl6->fl6_icmp_type = type;
825 fl6->fl6_icmp_code = 0;
826 fl6->flowi6_oif = oif;
827 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
828}
829
830/*
831 * Special lock-class for __icmpv6_sk:
832 */
833static struct lock_class_key icmpv6_socket_sk_dst_lock_key;
834
835static int __net_init icmpv6_sk_init(struct net *net)
836{
837 struct sock *sk;
838 int err, i, j;
839
840 net->ipv6.icmp_sk =
841 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
842 if (net->ipv6.icmp_sk == NULL)
843 return -ENOMEM;
844
845 for_each_possible_cpu(i) {
846 err = inet_ctl_sock_create(&sk, PF_INET6,
847 SOCK_RAW, IPPROTO_ICMPV6, net);
848 if (err < 0) {
849 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
850 err);
851 goto fail;
852 }
853
854 net->ipv6.icmp_sk[i] = sk;
855
856 /*
857 * Split off their lock-class, because sk->sk_dst_lock
858 * gets used from softirqs, which is safe for
859 * __icmpv6_sk (because those never get directly used
860 * via userspace syscalls), but unsafe for normal sockets.
861 */
862 lockdep_set_class(&sk->sk_dst_lock,
863 &icmpv6_socket_sk_dst_lock_key);
864
865 /* Enough space for 2 64K ICMP packets, including
866 * sk_buff struct overhead.
867 */
868 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
869 }
870 return 0;
871
872 fail:
873 for (j = 0; j < i; j++)
874 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
875 kfree(net->ipv6.icmp_sk);
876 return err;
877}
878
879static void __net_exit icmpv6_sk_exit(struct net *net)
880{
881 int i;
882
883 for_each_possible_cpu(i) {
884 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
885 }
886 kfree(net->ipv6.icmp_sk);
887}
888
889static struct pernet_operations icmpv6_sk_ops = {
890 .init = icmpv6_sk_init,
891 .exit = icmpv6_sk_exit,
892};
893
894int __init icmpv6_init(void)
895{
896 int err;
897
898 err = register_pernet_subsys(&icmpv6_sk_ops);
899 if (err < 0)
900 return err;
901
902 err = -EAGAIN;
903 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
904 goto fail;
905
906 err = inet6_register_icmp_sender(icmp6_send);
907 if (err)
908 goto sender_reg_err;
909 return 0;
910
911sender_reg_err:
912 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
913fail:
914 pr_err("Failed to register ICMP6 protocol\n");
915 unregister_pernet_subsys(&icmpv6_sk_ops);
916 return err;
917}
918
919void icmpv6_cleanup(void)
920{
921 inet6_unregister_icmp_sender(icmp6_send);
922 unregister_pernet_subsys(&icmpv6_sk_ops);
923 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
924}
925
926
927static const struct icmp6_err {
928 int err;
929 int fatal;
930} tab_unreach[] = {
931 { /* NOROUTE */
932 .err = ENETUNREACH,
933 .fatal = 0,
934 },
935 { /* ADM_PROHIBITED */
936 .err = EACCES,
937 .fatal = 1,
938 },
939 { /* Was NOT_NEIGHBOUR, now reserved */
940 .err = EHOSTUNREACH,
941 .fatal = 0,
942 },
943 { /* ADDR_UNREACH */
944 .err = EHOSTUNREACH,
945 .fatal = 0,
946 },
947 { /* PORT_UNREACH */
948 .err = ECONNREFUSED,
949 .fatal = 1,
950 },
951 { /* POLICY_FAIL */
952 .err = EACCES,
953 .fatal = 1,
954 },
955 { /* REJECT_ROUTE */
956 .err = EACCES,
957 .fatal = 1,
958 },
959};
960
961int icmpv6_err_convert(u8 type, u8 code, int *err)
962{
963 int fatal = 0;
964
965 *err = EPROTO;
966
967 switch (type) {
968 case ICMPV6_DEST_UNREACH:
969 fatal = 1;
970 if (code < ARRAY_SIZE(tab_unreach)) {
971 *err = tab_unreach[code].err;
972 fatal = tab_unreach[code].fatal;
973 }
974 break;
975
976 case ICMPV6_PKT_TOOBIG:
977 *err = EMSGSIZE;
978 break;
979
980 case ICMPV6_PARAMPROB:
981 *err = EPROTO;
982 fatal = 1;
983 break;
984
985 case ICMPV6_TIME_EXCEED:
986 *err = EHOSTUNREACH;
987 break;
988 }
989
990 return fatal;
991}
992EXPORT_SYMBOL(icmpv6_err_convert);
993
994#ifdef CONFIG_SYSCTL
995static struct ctl_table ipv6_icmp_table_template[] = {
996 {
997 .procname = "ratelimit",
998 .data = &init_net.ipv6.sysctl.icmpv6_time,
999 .maxlen = sizeof(int),
1000 .mode = 0644,
1001 .proc_handler = proc_dointvec_ms_jiffies,
1002 },
1003 { },
1004};
1005
1006struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1007{
1008 struct ctl_table *table;
1009
1010 table = kmemdup(ipv6_icmp_table_template,
1011 sizeof(ipv6_icmp_table_template),
1012 GFP_KERNEL);
1013
1014 if (table)
1015 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1016
1017 return table;
1018}
1019#endif
1020