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1/*
2 * Internet Control Message Protocol (ICMPv6)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on net/ipv4/icmp.c
9 *
10 * RFC 1885
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18/*
19 * Changes:
20 *
21 * Andi Kleen : exception handling
22 * Andi Kleen add rate limits. never reply to a icmp.
23 * add more length checks and other fixes.
24 * yoshfuji : ensure to sent parameter problem for
25 * fragments.
26 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
27 * Randy Dunlap and
28 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
29 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
30 */
31
32#define pr_fmt(fmt) "IPv6: " fmt
33
34#include <linux/module.h>
35#include <linux/errno.h>
36#include <linux/types.h>
37#include <linux/socket.h>
38#include <linux/in.h>
39#include <linux/kernel.h>
40#include <linux/sockios.h>
41#include <linux/net.h>
42#include <linux/skbuff.h>
43#include <linux/init.h>
44#include <linux/netfilter.h>
45#include <linux/slab.h>
46
47#ifdef CONFIG_SYSCTL
48#include <linux/sysctl.h>
49#endif
50
51#include <linux/inet.h>
52#include <linux/netdevice.h>
53#include <linux/icmpv6.h>
54
55#include <net/ip.h>
56#include <net/sock.h>
57
58#include <net/ipv6.h>
59#include <net/ip6_checksum.h>
60#include <net/ping.h>
61#include <net/protocol.h>
62#include <net/raw.h>
63#include <net/rawv6.h>
64#include <net/transp_v6.h>
65#include <net/ip6_route.h>
66#include <net/addrconf.h>
67#include <net/icmp.h>
68#include <net/xfrm.h>
69#include <net/inet_common.h>
70#include <net/dsfield.h>
71
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
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
162 /* Based on RFC 8200, Section 4.5 Fragment Header, return
163 * false if this is a fragment packet with no icmp header info.
164 */
165 if (!tp && frag_off != 0)
166 return false;
167 else if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
168 return true;
169 }
170 return false;
171}
172
173static bool icmpv6_mask_allow(struct net *net, int type)
174{
175 if (type > ICMPV6_MSG_MAX)
176 return true;
177
178 /* Limit if icmp type is set in ratemask. */
179 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
180 return true;
181
182 return false;
183}
184
185static bool icmpv6_global_allow(struct net *net, int type)
186{
187 if (icmpv6_mask_allow(net, type))
188 return true;
189
190 if (icmp_global_allow())
191 return true;
192
193 return false;
194}
195
196/*
197 * Check the ICMP output rate limit
198 */
199static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
200 struct flowi6 *fl6)
201{
202 struct net *net = sock_net(sk);
203 struct dst_entry *dst;
204 bool res = false;
205
206 if (icmpv6_mask_allow(net, type))
207 return true;
208
209 /*
210 * Look up the output route.
211 * XXX: perhaps the expire for routing entries cloned by
212 * this lookup should be more aggressive (not longer than timeout).
213 */
214 dst = ip6_route_output(net, sk, fl6);
215 if (dst->error) {
216 IP6_INC_STATS(net, ip6_dst_idev(dst),
217 IPSTATS_MIB_OUTNOROUTES);
218 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
219 res = true;
220 } else {
221 struct rt6_info *rt = (struct rt6_info *)dst;
222 int tmo = net->ipv6.sysctl.icmpv6_time;
223 struct inet_peer *peer;
224
225 /* Give more bandwidth to wider prefixes. */
226 if (rt->rt6i_dst.plen < 128)
227 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
228
229 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
230 res = inet_peer_xrlim_allow(peer, tmo);
231 if (peer)
232 inet_putpeer(peer);
233 }
234 dst_release(dst);
235 return res;
236}
237
238static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type,
239 struct flowi6 *fl6)
240{
241 struct net *net = sock_net(sk);
242 struct dst_entry *dst;
243 bool res = false;
244
245 dst = ip6_route_output(net, sk, fl6);
246 if (!dst->error) {
247 struct rt6_info *rt = (struct rt6_info *)dst;
248 struct in6_addr prefsrc;
249
250 rt6_get_prefsrc(rt, &prefsrc);
251 res = !ipv6_addr_any(&prefsrc);
252 }
253 dst_release(dst);
254 return res;
255}
256
257/*
258 * an inline helper for the "simple" if statement below
259 * checks if parameter problem report is caused by an
260 * unrecognized IPv6 option that has the Option Type
261 * highest-order two bits set to 10
262 */
263
264static bool opt_unrec(struct sk_buff *skb, __u32 offset)
265{
266 u8 _optval, *op;
267
268 offset += skb_network_offset(skb);
269 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
270 if (!op)
271 return true;
272 return (*op & 0xC0) == 0x80;
273}
274
275void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
276 struct icmp6hdr *thdr, int len)
277{
278 struct sk_buff *skb;
279 struct icmp6hdr *icmp6h;
280
281 skb = skb_peek(&sk->sk_write_queue);
282 if (!skb)
283 return;
284
285 icmp6h = icmp6_hdr(skb);
286 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
287 icmp6h->icmp6_cksum = 0;
288
289 if (skb_queue_len(&sk->sk_write_queue) == 1) {
290 skb->csum = csum_partial(icmp6h,
291 sizeof(struct icmp6hdr), skb->csum);
292 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
293 &fl6->daddr,
294 len, fl6->flowi6_proto,
295 skb->csum);
296 } else {
297 __wsum tmp_csum = 0;
298
299 skb_queue_walk(&sk->sk_write_queue, skb) {
300 tmp_csum = csum_add(tmp_csum, skb->csum);
301 }
302
303 tmp_csum = csum_partial(icmp6h,
304 sizeof(struct icmp6hdr), tmp_csum);
305 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
306 &fl6->daddr,
307 len, fl6->flowi6_proto,
308 tmp_csum);
309 }
310 ip6_push_pending_frames(sk);
311}
312
313struct icmpv6_msg {
314 struct sk_buff *skb;
315 int offset;
316 uint8_t type;
317};
318
319static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
320{
321 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
322 struct sk_buff *org_skb = msg->skb;
323 __wsum csum;
324
325 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
326 to, len);
327 skb->csum = csum_block_add(skb->csum, csum, odd);
328 if (!(msg->type & ICMPV6_INFOMSG_MASK))
329 nf_ct_attach(skb, org_skb);
330 return 0;
331}
332
333#if IS_ENABLED(CONFIG_IPV6_MIP6)
334static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt)
335{
336 struct ipv6hdr *iph = ipv6_hdr(skb);
337 struct ipv6_destopt_hao *hao;
338 struct in6_addr tmp;
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 tmp = iph->saddr;
347 iph->saddr = hao->addr;
348 hao->addr = tmp;
349 }
350 }
351}
352#else
353static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {}
354#endif
355
356static struct dst_entry *icmpv6_route_lookup(struct net *net,
357 struct sk_buff *skb,
358 struct sock *sk,
359 struct flowi6 *fl6)
360{
361 struct dst_entry *dst, *dst2;
362 struct flowi6 fl2;
363 int err;
364
365 err = ip6_dst_lookup(net, sk, &dst, fl6);
366 if (err)
367 return ERR_PTR(err);
368
369 /*
370 * We won't send icmp if the destination is known
371 * anycast.
372 */
373 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
374 net_dbg_ratelimited("icmp6_send: acast source\n");
375 dst_release(dst);
376 return ERR_PTR(-EINVAL);
377 }
378
379 /* No need to clone since we're just using its address. */
380 dst2 = dst;
381
382 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
383 if (!IS_ERR(dst)) {
384 if (dst != dst2)
385 return dst;
386 } else {
387 if (PTR_ERR(dst) == -EPERM)
388 dst = NULL;
389 else
390 return dst;
391 }
392
393 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
394 if (err)
395 goto relookup_failed;
396
397 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
398 if (err)
399 goto relookup_failed;
400
401 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
402 if (!IS_ERR(dst2)) {
403 dst_release(dst);
404 dst = dst2;
405 } else {
406 err = PTR_ERR(dst2);
407 if (err == -EPERM) {
408 dst_release(dst);
409 return dst2;
410 } else
411 goto relookup_failed;
412 }
413
414relookup_failed:
415 if (dst)
416 return dst;
417 return ERR_PTR(err);
418}
419
420static struct net_device *icmp6_dev(const struct sk_buff *skb)
421{
422 struct net_device *dev = skb->dev;
423
424 /* for local traffic to local address, skb dev is the loopback
425 * device. Check if there is a dst attached to the skb and if so
426 * get the real device index. Same is needed for replies to a link
427 * local address on a device enslaved to an L3 master device
428 */
429 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
430 const struct rt6_info *rt6 = skb_rt6_info(skb);
431
432 if (rt6)
433 dev = rt6->rt6i_idev->dev;
434 }
435
436 return dev;
437}
438
439static int icmp6_iif(const struct sk_buff *skb)
440{
441 return icmp6_dev(skb)->ifindex;
442}
443
444/*
445 * Send an ICMP message in response to a packet in error
446 */
447void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
448 const struct in6_addr *force_saddr,
449 const struct inet6_skb_parm *parm)
450{
451 struct inet6_dev *idev = NULL;
452 struct ipv6hdr *hdr = ipv6_hdr(skb);
453 struct sock *sk;
454 struct net *net;
455 struct ipv6_pinfo *np;
456 const struct in6_addr *saddr = NULL;
457 struct dst_entry *dst;
458 struct icmp6hdr tmp_hdr;
459 struct flowi6 fl6;
460 struct icmpv6_msg msg;
461 struct ipcm6_cookie ipc6;
462 int iif = 0;
463 int addr_type = 0;
464 int len;
465 u32 mark;
466
467 if ((u8 *)hdr < skb->head ||
468 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
469 return;
470
471 if (!skb->dev)
472 return;
473 net = dev_net(skb->dev);
474 mark = IP6_REPLY_MARK(net, skb->mark);
475 /*
476 * Make sure we respect the rules
477 * i.e. RFC 1885 2.4(e)
478 * Rule (e.1) is enforced by not using icmp6_send
479 * in any code that processes icmp errors.
480 */
481 addr_type = ipv6_addr_type(&hdr->daddr);
482
483 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
484 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
485 saddr = &hdr->daddr;
486
487 /*
488 * Dest addr check
489 */
490
491 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
492 if (type != ICMPV6_PKT_TOOBIG &&
493 !(type == ICMPV6_PARAMPROB &&
494 code == ICMPV6_UNK_OPTION &&
495 (opt_unrec(skb, info))))
496 return;
497
498 saddr = NULL;
499 }
500
501 addr_type = ipv6_addr_type(&hdr->saddr);
502
503 /*
504 * Source addr check
505 */
506
507 if (__ipv6_addr_needs_scope_id(addr_type)) {
508 iif = icmp6_iif(skb);
509 } else {
510 /*
511 * The source device is used for looking up which routing table
512 * to use for sending an ICMP error.
513 */
514 iif = l3mdev_master_ifindex(skb->dev);
515 }
516
517 /*
518 * Must not send error if the source does not uniquely
519 * identify a single node (RFC2463 Section 2.4).
520 * We check unspecified / multicast addresses here,
521 * and anycast addresses will be checked later.
522 */
523 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
524 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
525 &hdr->saddr, &hdr->daddr);
526 return;
527 }
528
529 /*
530 * Never answer to a ICMP packet.
531 */
532 if (is_ineligible(skb)) {
533 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
534 &hdr->saddr, &hdr->daddr);
535 return;
536 }
537
538 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
539 local_bh_disable();
540
541 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
542 if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
543 goto out_bh_enable;
544
545 mip6_addr_swap(skb, parm);
546
547 sk = icmpv6_xmit_lock(net);
548 if (!sk)
549 goto out_bh_enable;
550
551 memset(&fl6, 0, sizeof(fl6));
552 fl6.flowi6_proto = IPPROTO_ICMPV6;
553 fl6.daddr = hdr->saddr;
554 if (force_saddr)
555 saddr = force_saddr;
556 if (saddr) {
557 fl6.saddr = *saddr;
558 } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) {
559 /* select a more meaningful saddr from input if */
560 struct net_device *in_netdev;
561
562 in_netdev = dev_get_by_index(net, parm->iif);
563 if (in_netdev) {
564 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
565 inet6_sk(sk)->srcprefs,
566 &fl6.saddr);
567 dev_put(in_netdev);
568 }
569 }
570 fl6.flowi6_mark = mark;
571 fl6.flowi6_oif = iif;
572 fl6.fl6_icmp_type = type;
573 fl6.fl6_icmp_code = code;
574 fl6.flowi6_uid = sock_net_uid(net, NULL);
575 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
576 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
577
578 np = inet6_sk(sk);
579
580 if (!icmpv6_xrlim_allow(sk, type, &fl6))
581 goto out;
582
583 tmp_hdr.icmp6_type = type;
584 tmp_hdr.icmp6_code = code;
585 tmp_hdr.icmp6_cksum = 0;
586 tmp_hdr.icmp6_pointer = htonl(info);
587
588 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
589 fl6.flowi6_oif = np->mcast_oif;
590 else if (!fl6.flowi6_oif)
591 fl6.flowi6_oif = np->ucast_oif;
592
593 ipcm6_init_sk(&ipc6, np);
594 ipc6.sockc.mark = mark;
595 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
596
597 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
598 if (IS_ERR(dst))
599 goto out;
600
601 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
602
603 msg.skb = skb;
604 msg.offset = skb_network_offset(skb);
605 msg.type = type;
606
607 len = skb->len - msg.offset;
608 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
609 if (len < 0) {
610 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
611 &hdr->saddr, &hdr->daddr);
612 goto out_dst_release;
613 }
614
615 rcu_read_lock();
616 idev = __in6_dev_get(skb->dev);
617
618 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
619 len + sizeof(struct icmp6hdr),
620 sizeof(struct icmp6hdr),
621 &ipc6, &fl6, (struct rt6_info *)dst,
622 MSG_DONTWAIT)) {
623 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
624 ip6_flush_pending_frames(sk);
625 } else {
626 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
627 len + sizeof(struct icmp6hdr));
628 }
629 rcu_read_unlock();
630out_dst_release:
631 dst_release(dst);
632out:
633 icmpv6_xmit_unlock(sk);
634out_bh_enable:
635 local_bh_enable();
636}
637EXPORT_SYMBOL(icmp6_send);
638
639/* Slightly more convenient version of icmp6_send.
640 */
641void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
642{
643 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
644 kfree_skb(skb);
645}
646
647/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
648 * if sufficient data bytes are available
649 * @nhs is the size of the tunnel header(s) :
650 * Either an IPv4 header for SIT encap
651 * an IPv4 header + GRE header for GRE encap
652 */
653int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
654 unsigned int data_len)
655{
656 struct in6_addr temp_saddr;
657 struct rt6_info *rt;
658 struct sk_buff *skb2;
659 u32 info = 0;
660
661 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
662 return 1;
663
664 /* RFC 4884 (partial) support for ICMP extensions */
665 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
666 data_len = 0;
667
668 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
669
670 if (!skb2)
671 return 1;
672
673 skb_dst_drop(skb2);
674 skb_pull(skb2, nhs);
675 skb_reset_network_header(skb2);
676
677 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
678 skb, 0);
679
680 if (rt && rt->dst.dev)
681 skb2->dev = rt->dst.dev;
682
683 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
684
685 if (data_len) {
686 /* RFC 4884 (partial) support :
687 * insert 0 padding at the end, before the extensions
688 */
689 __skb_push(skb2, nhs);
690 skb_reset_network_header(skb2);
691 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
692 memset(skb2->data + data_len - nhs, 0, nhs);
693 /* RFC 4884 4.5 : Length is measured in 64-bit words,
694 * and stored in reserved[0]
695 */
696 info = (data_len/8) << 24;
697 }
698 if (type == ICMP_TIME_EXCEEDED)
699 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
700 info, &temp_saddr, IP6CB(skb2));
701 else
702 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
703 info, &temp_saddr, IP6CB(skb2));
704 if (rt)
705 ip6_rt_put(rt);
706
707 kfree_skb(skb2);
708
709 return 0;
710}
711EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
712
713static void icmpv6_echo_reply(struct sk_buff *skb)
714{
715 struct net *net = dev_net(skb->dev);
716 struct sock *sk;
717 struct inet6_dev *idev;
718 struct ipv6_pinfo *np;
719 const struct in6_addr *saddr = NULL;
720 struct icmp6hdr *icmph = icmp6_hdr(skb);
721 struct icmp6hdr tmp_hdr;
722 struct flowi6 fl6;
723 struct icmpv6_msg msg;
724 struct dst_entry *dst;
725 struct ipcm6_cookie ipc6;
726 u32 mark = IP6_REPLY_MARK(net, skb->mark);
727 bool acast;
728 u8 type;
729
730 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
731 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
732 return;
733
734 saddr = &ipv6_hdr(skb)->daddr;
735
736 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
737 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
738 return;
739
740 if (!ipv6_unicast_destination(skb) &&
741 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
742 saddr = NULL;
743
744 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
745 type = ICMPV6_EXT_ECHO_REPLY;
746 else
747 type = ICMPV6_ECHO_REPLY;
748
749 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
750 tmp_hdr.icmp6_type = type;
751
752 memset(&fl6, 0, sizeof(fl6));
753 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
754 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
755
756 fl6.flowi6_proto = IPPROTO_ICMPV6;
757 fl6.daddr = ipv6_hdr(skb)->saddr;
758 if (saddr)
759 fl6.saddr = *saddr;
760 fl6.flowi6_oif = icmp6_iif(skb);
761 fl6.fl6_icmp_type = type;
762 fl6.flowi6_mark = mark;
763 fl6.flowi6_uid = sock_net_uid(net, NULL);
764 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
765
766 local_bh_disable();
767 sk = icmpv6_xmit_lock(net);
768 if (!sk)
769 goto out_bh_enable;
770 np = inet6_sk(sk);
771
772 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
773 fl6.flowi6_oif = np->mcast_oif;
774 else if (!fl6.flowi6_oif)
775 fl6.flowi6_oif = np->ucast_oif;
776
777 if (ip6_dst_lookup(net, sk, &dst, &fl6))
778 goto out;
779 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
780 if (IS_ERR(dst))
781 goto out;
782
783 /* Check the ratelimit */
784 if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
785 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
786 goto out_dst_release;
787
788 idev = __in6_dev_get(skb->dev);
789
790 msg.skb = skb;
791 msg.offset = 0;
792 msg.type = type;
793
794 ipcm6_init_sk(&ipc6, np);
795 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
796 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
797 ipc6.sockc.mark = mark;
798
799 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
800 if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr))
801 goto out_dst_release;
802
803 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
804 skb->len + sizeof(struct icmp6hdr),
805 sizeof(struct icmp6hdr), &ipc6, &fl6,
806 (struct rt6_info *)dst, MSG_DONTWAIT)) {
807 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
808 ip6_flush_pending_frames(sk);
809 } else {
810 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
811 skb->len + sizeof(struct icmp6hdr));
812 }
813out_dst_release:
814 dst_release(dst);
815out:
816 icmpv6_xmit_unlock(sk);
817out_bh_enable:
818 local_bh_enable();
819}
820
821void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
822{
823 const struct inet6_protocol *ipprot;
824 int inner_offset;
825 __be16 frag_off;
826 u8 nexthdr;
827 struct net *net = dev_net(skb->dev);
828
829 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
830 goto out;
831
832 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
833 if (ipv6_ext_hdr(nexthdr)) {
834 /* now skip over extension headers */
835 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
836 &nexthdr, &frag_off);
837 if (inner_offset < 0)
838 goto out;
839 } else {
840 inner_offset = sizeof(struct ipv6hdr);
841 }
842
843 /* Checkin header including 8 bytes of inner protocol header. */
844 if (!pskb_may_pull(skb, inner_offset+8))
845 goto out;
846
847 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
848 Without this we will not able f.e. to make source routed
849 pmtu discovery.
850 Corresponding argument (opt) to notifiers is already added.
851 --ANK (980726)
852 */
853
854 ipprot = rcu_dereference(inet6_protos[nexthdr]);
855 if (ipprot && ipprot->err_handler)
856 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
857
858 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
859 return;
860
861out:
862 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
863}
864
865/*
866 * Handle icmp messages
867 */
868
869static int icmpv6_rcv(struct sk_buff *skb)
870{
871 struct net *net = dev_net(skb->dev);
872 struct net_device *dev = icmp6_dev(skb);
873 struct inet6_dev *idev = __in6_dev_get(dev);
874 const struct in6_addr *saddr, *daddr;
875 struct icmp6hdr *hdr;
876 u8 type;
877 bool success = false;
878
879 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
880 struct sec_path *sp = skb_sec_path(skb);
881 int nh;
882
883 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
884 XFRM_STATE_ICMP))
885 goto drop_no_count;
886
887 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
888 goto drop_no_count;
889
890 nh = skb_network_offset(skb);
891 skb_set_network_header(skb, sizeof(*hdr));
892
893 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
894 goto drop_no_count;
895
896 skb_set_network_header(skb, nh);
897 }
898
899 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
900
901 saddr = &ipv6_hdr(skb)->saddr;
902 daddr = &ipv6_hdr(skb)->daddr;
903
904 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
905 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
906 saddr, daddr);
907 goto csum_error;
908 }
909
910 if (!pskb_pull(skb, sizeof(*hdr)))
911 goto discard_it;
912
913 hdr = icmp6_hdr(skb);
914
915 type = hdr->icmp6_type;
916
917 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
918
919 switch (type) {
920 case ICMPV6_ECHO_REQUEST:
921 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
922 icmpv6_echo_reply(skb);
923 break;
924 case ICMPV6_EXT_ECHO_REQUEST:
925 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all &&
926 net->ipv4.sysctl_icmp_echo_enable_probe)
927 icmpv6_echo_reply(skb);
928 break;
929
930 case ICMPV6_ECHO_REPLY:
931 success = ping_rcv(skb);
932 break;
933
934 case ICMPV6_EXT_ECHO_REPLY:
935 success = ping_rcv(skb);
936 break;
937
938 case ICMPV6_PKT_TOOBIG:
939 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
940 standard destination cache. Seems, only "advanced"
941 destination cache will allow to solve this problem
942 --ANK (980726)
943 */
944 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
945 goto discard_it;
946 hdr = icmp6_hdr(skb);
947
948 /* to notify */
949 fallthrough;
950 case ICMPV6_DEST_UNREACH:
951 case ICMPV6_TIME_EXCEED:
952 case ICMPV6_PARAMPROB:
953 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
954 break;
955
956 case NDISC_ROUTER_SOLICITATION:
957 case NDISC_ROUTER_ADVERTISEMENT:
958 case NDISC_NEIGHBOUR_SOLICITATION:
959 case NDISC_NEIGHBOUR_ADVERTISEMENT:
960 case NDISC_REDIRECT:
961 ndisc_rcv(skb);
962 break;
963
964 case ICMPV6_MGM_QUERY:
965 igmp6_event_query(skb);
966 return 0;
967
968 case ICMPV6_MGM_REPORT:
969 igmp6_event_report(skb);
970 return 0;
971
972 case ICMPV6_MGM_REDUCTION:
973 case ICMPV6_NI_QUERY:
974 case ICMPV6_NI_REPLY:
975 case ICMPV6_MLD2_REPORT:
976 case ICMPV6_DHAAD_REQUEST:
977 case ICMPV6_DHAAD_REPLY:
978 case ICMPV6_MOBILE_PREFIX_SOL:
979 case ICMPV6_MOBILE_PREFIX_ADV:
980 break;
981
982 default:
983 /* informational */
984 if (type & ICMPV6_INFOMSG_MASK)
985 break;
986
987 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
988 saddr, daddr);
989
990 /*
991 * error of unknown type.
992 * must pass to upper level
993 */
994
995 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
996 }
997
998 /* until the v6 path can be better sorted assume failure and
999 * preserve the status quo behaviour for the rest of the paths to here
1000 */
1001 if (success)
1002 consume_skb(skb);
1003 else
1004 kfree_skb(skb);
1005
1006 return 0;
1007
1008csum_error:
1009 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
1010discard_it:
1011 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
1012drop_no_count:
1013 kfree_skb(skb);
1014 return 0;
1015}
1016
1017void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
1018 u8 type,
1019 const struct in6_addr *saddr,
1020 const struct in6_addr *daddr,
1021 int oif)
1022{
1023 memset(fl6, 0, sizeof(*fl6));
1024 fl6->saddr = *saddr;
1025 fl6->daddr = *daddr;
1026 fl6->flowi6_proto = IPPROTO_ICMPV6;
1027 fl6->fl6_icmp_type = type;
1028 fl6->fl6_icmp_code = 0;
1029 fl6->flowi6_oif = oif;
1030 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1031}
1032
1033static void __net_exit icmpv6_sk_exit(struct net *net)
1034{
1035 int i;
1036
1037 for_each_possible_cpu(i)
1038 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv6.icmp_sk, i));
1039 free_percpu(net->ipv6.icmp_sk);
1040}
1041
1042static int __net_init icmpv6_sk_init(struct net *net)
1043{
1044 struct sock *sk;
1045 int err, i;
1046
1047 net->ipv6.icmp_sk = alloc_percpu(struct sock *);
1048 if (!net->ipv6.icmp_sk)
1049 return -ENOMEM;
1050
1051 for_each_possible_cpu(i) {
1052 err = inet_ctl_sock_create(&sk, PF_INET6,
1053 SOCK_RAW, IPPROTO_ICMPV6, net);
1054 if (err < 0) {
1055 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
1056 err);
1057 goto fail;
1058 }
1059
1060 *per_cpu_ptr(net->ipv6.icmp_sk, i) = sk;
1061
1062 /* Enough space for 2 64K ICMP packets, including
1063 * sk_buff struct overhead.
1064 */
1065 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1066 }
1067 return 0;
1068
1069 fail:
1070 icmpv6_sk_exit(net);
1071 return err;
1072}
1073
1074static struct pernet_operations icmpv6_sk_ops = {
1075 .init = icmpv6_sk_init,
1076 .exit = icmpv6_sk_exit,
1077};
1078
1079int __init icmpv6_init(void)
1080{
1081 int err;
1082
1083 err = register_pernet_subsys(&icmpv6_sk_ops);
1084 if (err < 0)
1085 return err;
1086
1087 err = -EAGAIN;
1088 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1089 goto fail;
1090
1091 err = inet6_register_icmp_sender(icmp6_send);
1092 if (err)
1093 goto sender_reg_err;
1094 return 0;
1095
1096sender_reg_err:
1097 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1098fail:
1099 pr_err("Failed to register ICMP6 protocol\n");
1100 unregister_pernet_subsys(&icmpv6_sk_ops);
1101 return err;
1102}
1103
1104void icmpv6_cleanup(void)
1105{
1106 inet6_unregister_icmp_sender(icmp6_send);
1107 unregister_pernet_subsys(&icmpv6_sk_ops);
1108 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1109}
1110
1111
1112static const struct icmp6_err {
1113 int err;
1114 int fatal;
1115} tab_unreach[] = {
1116 { /* NOROUTE */
1117 .err = ENETUNREACH,
1118 .fatal = 0,
1119 },
1120 { /* ADM_PROHIBITED */
1121 .err = EACCES,
1122 .fatal = 1,
1123 },
1124 { /* Was NOT_NEIGHBOUR, now reserved */
1125 .err = EHOSTUNREACH,
1126 .fatal = 0,
1127 },
1128 { /* ADDR_UNREACH */
1129 .err = EHOSTUNREACH,
1130 .fatal = 0,
1131 },
1132 { /* PORT_UNREACH */
1133 .err = ECONNREFUSED,
1134 .fatal = 1,
1135 },
1136 { /* POLICY_FAIL */
1137 .err = EACCES,
1138 .fatal = 1,
1139 },
1140 { /* REJECT_ROUTE */
1141 .err = EACCES,
1142 .fatal = 1,
1143 },
1144};
1145
1146int icmpv6_err_convert(u8 type, u8 code, int *err)
1147{
1148 int fatal = 0;
1149
1150 *err = EPROTO;
1151
1152 switch (type) {
1153 case ICMPV6_DEST_UNREACH:
1154 fatal = 1;
1155 if (code < ARRAY_SIZE(tab_unreach)) {
1156 *err = tab_unreach[code].err;
1157 fatal = tab_unreach[code].fatal;
1158 }
1159 break;
1160
1161 case ICMPV6_PKT_TOOBIG:
1162 *err = EMSGSIZE;
1163 break;
1164
1165 case ICMPV6_PARAMPROB:
1166 *err = EPROTO;
1167 fatal = 1;
1168 break;
1169
1170 case ICMPV6_TIME_EXCEED:
1171 *err = EHOSTUNREACH;
1172 break;
1173 }
1174
1175 return fatal;
1176}
1177EXPORT_SYMBOL(icmpv6_err_convert);
1178
1179#ifdef CONFIG_SYSCTL
1180static struct ctl_table ipv6_icmp_table_template[] = {
1181 {
1182 .procname = "ratelimit",
1183 .data = &init_net.ipv6.sysctl.icmpv6_time,
1184 .maxlen = sizeof(int),
1185 .mode = 0644,
1186 .proc_handler = proc_dointvec_ms_jiffies,
1187 },
1188 {
1189 .procname = "echo_ignore_all",
1190 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1191 .maxlen = sizeof(u8),
1192 .mode = 0644,
1193 .proc_handler = proc_dou8vec_minmax,
1194 },
1195 {
1196 .procname = "echo_ignore_multicast",
1197 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1198 .maxlen = sizeof(u8),
1199 .mode = 0644,
1200 .proc_handler = proc_dou8vec_minmax,
1201 },
1202 {
1203 .procname = "echo_ignore_anycast",
1204 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1205 .maxlen = sizeof(u8),
1206 .mode = 0644,
1207 .proc_handler = proc_dou8vec_minmax,
1208 },
1209 {
1210 .procname = "ratemask",
1211 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1212 .maxlen = ICMPV6_MSG_MAX + 1,
1213 .mode = 0644,
1214 .proc_handler = proc_do_large_bitmap,
1215 },
1216 { },
1217};
1218
1219struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1220{
1221 struct ctl_table *table;
1222
1223 table = kmemdup(ipv6_icmp_table_template,
1224 sizeof(ipv6_icmp_table_template),
1225 GFP_KERNEL);
1226
1227 if (table) {
1228 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1229 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1230 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1231 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1232 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1233 }
1234 return table;
1235}
1236#endif