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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/*
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#include <linux/module.h>
33#include <linux/errno.h>
34#include <linux/types.h>
35#include <linux/socket.h>
36#include <linux/in.h>
37#include <linux/kernel.h>
38#include <linux/sockios.h>
39#include <linux/net.h>
40#include <linux/skbuff.h>
41#include <linux/init.h>
42#include <linux/netfilter.h>
43#include <linux/slab.h>
44
45#ifdef CONFIG_SYSCTL
46#include <linux/sysctl.h>
47#endif
48
49#include <linux/inet.h>
50#include <linux/netdevice.h>
51#include <linux/icmpv6.h>
52
53#include <net/ip.h>
54#include <net/sock.h>
55
56#include <net/ipv6.h>
57#include <net/ip6_checksum.h>
58#include <net/protocol.h>
59#include <net/raw.h>
60#include <net/rawv6.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
68#include <asm/uaccess.h>
69#include <asm/system.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 inline struct sock *icmpv6_sk(struct net *net)
79{
80 return net->ipv6.icmp_sk[smp_processor_id()];
81}
82
83static int icmpv6_rcv(struct sk_buff *skb);
84
85static const struct inet6_protocol icmpv6_protocol = {
86 .handler = icmpv6_rcv,
87 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
88};
89
90static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
91{
92 struct sock *sk;
93
94 local_bh_disable();
95
96 sk = icmpv6_sk(net);
97 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
98 /* This can happen if the output path (f.e. SIT or
99 * ip6ip6 tunnel) signals dst_link_failure() for an
100 * outgoing ICMP6 packet.
101 */
102 local_bh_enable();
103 return NULL;
104 }
105 return sk;
106}
107
108static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
109{
110 spin_unlock_bh(&sk->sk_lock.slock);
111}
112
113/*
114 * Slightly more convenient version of icmpv6_send.
115 */
116void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
117{
118 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
119 kfree_skb(skb);
120}
121
122/*
123 * Figure out, may we reply to this packet with icmp error.
124 *
125 * We do not reply, if:
126 * - it was icmp error message.
127 * - it is truncated, so that it is known, that protocol is ICMPV6
128 * (i.e. in the middle of some exthdr)
129 *
130 * --ANK (980726)
131 */
132
133static int is_ineligible(struct sk_buff *skb)
134{
135 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
136 int len = skb->len - ptr;
137 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
138
139 if (len < 0)
140 return 1;
141
142 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr);
143 if (ptr < 0)
144 return 0;
145 if (nexthdr == IPPROTO_ICMPV6) {
146 u8 _type, *tp;
147 tp = skb_header_pointer(skb,
148 ptr+offsetof(struct icmp6hdr, icmp6_type),
149 sizeof(_type), &_type);
150 if (tp == NULL ||
151 !(*tp & ICMPV6_INFOMSG_MASK))
152 return 1;
153 }
154 return 0;
155}
156
157/*
158 * Check the ICMP output rate limit
159 */
160static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
161 struct flowi6 *fl6)
162{
163 struct dst_entry *dst;
164 struct net *net = sock_net(sk);
165 bool res = false;
166
167 /* Informational messages are not limited. */
168 if (type & ICMPV6_INFOMSG_MASK)
169 return true;
170
171 /* Do not limit pmtu discovery, it would break it. */
172 if (type == ICMPV6_PKT_TOOBIG)
173 return true;
174
175 /*
176 * Look up the output route.
177 * XXX: perhaps the expire for routing entries cloned by
178 * this lookup should be more aggressive (not longer than timeout).
179 */
180 dst = ip6_route_output(net, sk, fl6);
181 if (dst->error) {
182 IP6_INC_STATS(net, ip6_dst_idev(dst),
183 IPSTATS_MIB_OUTNOROUTES);
184 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
185 res = true;
186 } else {
187 struct rt6_info *rt = (struct rt6_info *)dst;
188 int tmo = net->ipv6.sysctl.icmpv6_time;
189
190 /* Give more bandwidth to wider prefixes. */
191 if (rt->rt6i_dst.plen < 128)
192 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
193
194 if (!rt->rt6i_peer)
195 rt6_bind_peer(rt, 1);
196 res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo);
197 }
198 dst_release(dst);
199 return res;
200}
201
202/*
203 * an inline helper for the "simple" if statement below
204 * checks if parameter problem report is caused by an
205 * unrecognized IPv6 option that has the Option Type
206 * highest-order two bits set to 10
207 */
208
209static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset)
210{
211 u8 _optval, *op;
212
213 offset += skb_network_offset(skb);
214 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
215 if (op == NULL)
216 return 1;
217 return (*op & 0xC0) == 0x80;
218}
219
220static int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, struct icmp6hdr *thdr, int len)
221{
222 struct sk_buff *skb;
223 struct icmp6hdr *icmp6h;
224 int err = 0;
225
226 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
227 goto out;
228
229 icmp6h = icmp6_hdr(skb);
230 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
231 icmp6h->icmp6_cksum = 0;
232
233 if (skb_queue_len(&sk->sk_write_queue) == 1) {
234 skb->csum = csum_partial(icmp6h,
235 sizeof(struct icmp6hdr), skb->csum);
236 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
237 &fl6->daddr,
238 len, fl6->flowi6_proto,
239 skb->csum);
240 } else {
241 __wsum tmp_csum = 0;
242
243 skb_queue_walk(&sk->sk_write_queue, skb) {
244 tmp_csum = csum_add(tmp_csum, skb->csum);
245 }
246
247 tmp_csum = csum_partial(icmp6h,
248 sizeof(struct icmp6hdr), tmp_csum);
249 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
250 &fl6->daddr,
251 len, fl6->flowi6_proto,
252 tmp_csum);
253 }
254 ip6_push_pending_frames(sk);
255out:
256 return err;
257}
258
259struct icmpv6_msg {
260 struct sk_buff *skb;
261 int offset;
262 uint8_t type;
263};
264
265static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
266{
267 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
268 struct sk_buff *org_skb = msg->skb;
269 __wsum csum = 0;
270
271 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
272 to, len, csum);
273 skb->csum = csum_block_add(skb->csum, csum, odd);
274 if (!(msg->type & ICMPV6_INFOMSG_MASK))
275 nf_ct_attach(skb, org_skb);
276 return 0;
277}
278
279#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
280static void mip6_addr_swap(struct sk_buff *skb)
281{
282 struct ipv6hdr *iph = ipv6_hdr(skb);
283 struct inet6_skb_parm *opt = IP6CB(skb);
284 struct ipv6_destopt_hao *hao;
285 struct in6_addr tmp;
286 int off;
287
288 if (opt->dsthao) {
289 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
290 if (likely(off >= 0)) {
291 hao = (struct ipv6_destopt_hao *)
292 (skb_network_header(skb) + off);
293 ipv6_addr_copy(&tmp, &iph->saddr);
294 ipv6_addr_copy(&iph->saddr, &hao->addr);
295 ipv6_addr_copy(&hao->addr, &tmp);
296 }
297 }
298}
299#else
300static inline void mip6_addr_swap(struct sk_buff *skb) {}
301#endif
302
303static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
304 struct sock *sk, struct flowi6 *fl6)
305{
306 struct dst_entry *dst, *dst2;
307 struct flowi6 fl2;
308 int err;
309
310 err = ip6_dst_lookup(sk, &dst, fl6);
311 if (err)
312 return ERR_PTR(err);
313
314 /*
315 * We won't send icmp if the destination is known
316 * anycast.
317 */
318 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) {
319 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n");
320 dst_release(dst);
321 return ERR_PTR(-EINVAL);
322 }
323
324 /* No need to clone since we're just using its address. */
325 dst2 = dst;
326
327 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
328 if (!IS_ERR(dst)) {
329 if (dst != dst2)
330 return dst;
331 } else {
332 if (PTR_ERR(dst) == -EPERM)
333 dst = NULL;
334 else
335 return dst;
336 }
337
338 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
339 if (err)
340 goto relookup_failed;
341
342 err = ip6_dst_lookup(sk, &dst2, &fl2);
343 if (err)
344 goto relookup_failed;
345
346 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
347 if (!IS_ERR(dst2)) {
348 dst_release(dst);
349 dst = dst2;
350 } else {
351 err = PTR_ERR(dst2);
352 if (err == -EPERM) {
353 dst_release(dst);
354 return dst2;
355 } else
356 goto relookup_failed;
357 }
358
359relookup_failed:
360 if (dst)
361 return dst;
362 return ERR_PTR(err);
363}
364
365/*
366 * Send an ICMP message in response to a packet in error
367 */
368void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
369{
370 struct net *net = dev_net(skb->dev);
371 struct inet6_dev *idev = NULL;
372 struct ipv6hdr *hdr = ipv6_hdr(skb);
373 struct sock *sk;
374 struct ipv6_pinfo *np;
375 const struct in6_addr *saddr = NULL;
376 struct dst_entry *dst;
377 struct icmp6hdr tmp_hdr;
378 struct flowi6 fl6;
379 struct icmpv6_msg msg;
380 int iif = 0;
381 int addr_type = 0;
382 int len;
383 int hlimit;
384 int err = 0;
385
386 if ((u8 *)hdr < skb->head ||
387 (skb->network_header + sizeof(*hdr)) > skb->tail)
388 return;
389
390 /*
391 * Make sure we respect the rules
392 * i.e. RFC 1885 2.4(e)
393 * Rule (e.1) is enforced by not using icmpv6_send
394 * in any code that processes icmp errors.
395 */
396 addr_type = ipv6_addr_type(&hdr->daddr);
397
398 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0))
399 saddr = &hdr->daddr;
400
401 /*
402 * Dest addr check
403 */
404
405 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) {
406 if (type != ICMPV6_PKT_TOOBIG &&
407 !(type == ICMPV6_PARAMPROB &&
408 code == ICMPV6_UNK_OPTION &&
409 (opt_unrec(skb, info))))
410 return;
411
412 saddr = NULL;
413 }
414
415 addr_type = ipv6_addr_type(&hdr->saddr);
416
417 /*
418 * Source addr check
419 */
420
421 if (addr_type & IPV6_ADDR_LINKLOCAL)
422 iif = skb->dev->ifindex;
423
424 /*
425 * Must not send error if the source does not uniquely
426 * identify a single node (RFC2463 Section 2.4).
427 * We check unspecified / multicast addresses here,
428 * and anycast addresses will be checked later.
429 */
430 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
431 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n");
432 return;
433 }
434
435 /*
436 * Never answer to a ICMP packet.
437 */
438 if (is_ineligible(skb)) {
439 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n");
440 return;
441 }
442
443 mip6_addr_swap(skb);
444
445 memset(&fl6, 0, sizeof(fl6));
446 fl6.flowi6_proto = IPPROTO_ICMPV6;
447 ipv6_addr_copy(&fl6.daddr, &hdr->saddr);
448 if (saddr)
449 ipv6_addr_copy(&fl6.saddr, saddr);
450 fl6.flowi6_oif = iif;
451 fl6.fl6_icmp_type = type;
452 fl6.fl6_icmp_code = code;
453 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
454
455 sk = icmpv6_xmit_lock(net);
456 if (sk == NULL)
457 return;
458 np = inet6_sk(sk);
459
460 if (!icmpv6_xrlim_allow(sk, type, &fl6))
461 goto out;
462
463 tmp_hdr.icmp6_type = type;
464 tmp_hdr.icmp6_code = code;
465 tmp_hdr.icmp6_cksum = 0;
466 tmp_hdr.icmp6_pointer = htonl(info);
467
468 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
469 fl6.flowi6_oif = np->mcast_oif;
470
471 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
472 if (IS_ERR(dst))
473 goto out;
474
475 if (ipv6_addr_is_multicast(&fl6.daddr))
476 hlimit = np->mcast_hops;
477 else
478 hlimit = np->hop_limit;
479 if (hlimit < 0)
480 hlimit = ip6_dst_hoplimit(dst);
481
482 msg.skb = skb;
483 msg.offset = skb_network_offset(skb);
484 msg.type = type;
485
486 len = skb->len - msg.offset;
487 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
488 if (len < 0) {
489 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n");
490 goto out_dst_release;
491 }
492
493 idev = in6_dev_get(skb->dev);
494
495 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
496 len + sizeof(struct icmp6hdr),
497 sizeof(struct icmp6hdr), hlimit,
498 np->tclass, NULL, &fl6, (struct rt6_info*)dst,
499 MSG_DONTWAIT, np->dontfrag);
500 if (err) {
501 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
502 ip6_flush_pending_frames(sk);
503 goto out_put;
504 }
505 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, len + sizeof(struct icmp6hdr));
506
507out_put:
508 if (likely(idev != NULL))
509 in6_dev_put(idev);
510out_dst_release:
511 dst_release(dst);
512out:
513 icmpv6_xmit_unlock(sk);
514}
515
516EXPORT_SYMBOL(icmpv6_send);
517
518static void icmpv6_echo_reply(struct sk_buff *skb)
519{
520 struct net *net = dev_net(skb->dev);
521 struct sock *sk;
522 struct inet6_dev *idev;
523 struct ipv6_pinfo *np;
524 const struct in6_addr *saddr = NULL;
525 struct icmp6hdr *icmph = icmp6_hdr(skb);
526 struct icmp6hdr tmp_hdr;
527 struct flowi6 fl6;
528 struct icmpv6_msg msg;
529 struct dst_entry *dst;
530 int err = 0;
531 int hlimit;
532
533 saddr = &ipv6_hdr(skb)->daddr;
534
535 if (!ipv6_unicast_destination(skb))
536 saddr = NULL;
537
538 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
539 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
540
541 memset(&fl6, 0, sizeof(fl6));
542 fl6.flowi6_proto = IPPROTO_ICMPV6;
543 ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->saddr);
544 if (saddr)
545 ipv6_addr_copy(&fl6.saddr, saddr);
546 fl6.flowi6_oif = skb->dev->ifindex;
547 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
548 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
549
550 sk = icmpv6_xmit_lock(net);
551 if (sk == NULL)
552 return;
553 np = inet6_sk(sk);
554
555 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
556 fl6.flowi6_oif = np->mcast_oif;
557
558 err = ip6_dst_lookup(sk, &dst, &fl6);
559 if (err)
560 goto out;
561 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
562 if (IS_ERR(dst))
563 goto out;
564
565 if (ipv6_addr_is_multicast(&fl6.daddr))
566 hlimit = np->mcast_hops;
567 else
568 hlimit = np->hop_limit;
569 if (hlimit < 0)
570 hlimit = ip6_dst_hoplimit(dst);
571
572 idev = in6_dev_get(skb->dev);
573
574 msg.skb = skb;
575 msg.offset = 0;
576 msg.type = ICMPV6_ECHO_REPLY;
577
578 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
579 sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6,
580 (struct rt6_info*)dst, MSG_DONTWAIT,
581 np->dontfrag);
582
583 if (err) {
584 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
585 ip6_flush_pending_frames(sk);
586 goto out_put;
587 }
588 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, skb->len + sizeof(struct icmp6hdr));
589
590out_put:
591 if (likely(idev != NULL))
592 in6_dev_put(idev);
593 dst_release(dst);
594out:
595 icmpv6_xmit_unlock(sk);
596}
597
598static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
599{
600 const struct inet6_protocol *ipprot;
601 int inner_offset;
602 int hash;
603 u8 nexthdr;
604
605 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
606 return;
607
608 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
609 if (ipv6_ext_hdr(nexthdr)) {
610 /* now skip over extension headers */
611 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
612 if (inner_offset<0)
613 return;
614 } else {
615 inner_offset = sizeof(struct ipv6hdr);
616 }
617
618 /* Checkin header including 8 bytes of inner protocol header. */
619 if (!pskb_may_pull(skb, inner_offset+8))
620 return;
621
622 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
623 Without this we will not able f.e. to make source routed
624 pmtu discovery.
625 Corresponding argument (opt) to notifiers is already added.
626 --ANK (980726)
627 */
628
629 hash = nexthdr & (MAX_INET_PROTOS - 1);
630
631 rcu_read_lock();
632 ipprot = rcu_dereference(inet6_protos[hash]);
633 if (ipprot && ipprot->err_handler)
634 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
635 rcu_read_unlock();
636
637 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
638}
639
640/*
641 * Handle icmp messages
642 */
643
644static int icmpv6_rcv(struct sk_buff *skb)
645{
646 struct net_device *dev = skb->dev;
647 struct inet6_dev *idev = __in6_dev_get(dev);
648 const struct in6_addr *saddr, *daddr;
649 const struct ipv6hdr *orig_hdr;
650 struct icmp6hdr *hdr;
651 u8 type;
652
653 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
654 struct sec_path *sp = skb_sec_path(skb);
655 int nh;
656
657 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
658 XFRM_STATE_ICMP))
659 goto drop_no_count;
660
661 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr)))
662 goto drop_no_count;
663
664 nh = skb_network_offset(skb);
665 skb_set_network_header(skb, sizeof(*hdr));
666
667 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
668 goto drop_no_count;
669
670 skb_set_network_header(skb, nh);
671 }
672
673 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
674
675 saddr = &ipv6_hdr(skb)->saddr;
676 daddr = &ipv6_hdr(skb)->daddr;
677
678 /* Perform checksum. */
679 switch (skb->ip_summed) {
680 case CHECKSUM_COMPLETE:
681 if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
682 skb->csum))
683 break;
684 /* fall through */
685 case CHECKSUM_NONE:
686 skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len,
687 IPPROTO_ICMPV6, 0));
688 if (__skb_checksum_complete(skb)) {
689 LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n",
690 saddr, daddr);
691 goto discard_it;
692 }
693 }
694
695 if (!pskb_pull(skb, sizeof(*hdr)))
696 goto discard_it;
697
698 hdr = icmp6_hdr(skb);
699
700 type = hdr->icmp6_type;
701
702 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
703
704 switch (type) {
705 case ICMPV6_ECHO_REQUEST:
706 icmpv6_echo_reply(skb);
707 break;
708
709 case ICMPV6_ECHO_REPLY:
710 /* we couldn't care less */
711 break;
712
713 case ICMPV6_PKT_TOOBIG:
714 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
715 standard destination cache. Seems, only "advanced"
716 destination cache will allow to solve this problem
717 --ANK (980726)
718 */
719 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
720 goto discard_it;
721 hdr = icmp6_hdr(skb);
722 orig_hdr = (struct ipv6hdr *) (hdr + 1);
723 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev,
724 ntohl(hdr->icmp6_mtu));
725
726 /*
727 * Drop through to notify
728 */
729
730 case ICMPV6_DEST_UNREACH:
731 case ICMPV6_TIME_EXCEED:
732 case ICMPV6_PARAMPROB:
733 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
734 break;
735
736 case NDISC_ROUTER_SOLICITATION:
737 case NDISC_ROUTER_ADVERTISEMENT:
738 case NDISC_NEIGHBOUR_SOLICITATION:
739 case NDISC_NEIGHBOUR_ADVERTISEMENT:
740 case NDISC_REDIRECT:
741 ndisc_rcv(skb);
742 break;
743
744 case ICMPV6_MGM_QUERY:
745 igmp6_event_query(skb);
746 break;
747
748 case ICMPV6_MGM_REPORT:
749 igmp6_event_report(skb);
750 break;
751
752 case ICMPV6_MGM_REDUCTION:
753 case ICMPV6_NI_QUERY:
754 case ICMPV6_NI_REPLY:
755 case ICMPV6_MLD2_REPORT:
756 case ICMPV6_DHAAD_REQUEST:
757 case ICMPV6_DHAAD_REPLY:
758 case ICMPV6_MOBILE_PREFIX_SOL:
759 case ICMPV6_MOBILE_PREFIX_ADV:
760 break;
761
762 default:
763 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n");
764
765 /* informational */
766 if (type & ICMPV6_INFOMSG_MASK)
767 break;
768
769 /*
770 * error of unknown type.
771 * must pass to upper level
772 */
773
774 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
775 }
776
777 kfree_skb(skb);
778 return 0;
779
780discard_it:
781 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
782drop_no_count:
783 kfree_skb(skb);
784 return 0;
785}
786
787void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
788 u8 type,
789 const struct in6_addr *saddr,
790 const struct in6_addr *daddr,
791 int oif)
792{
793 memset(fl6, 0, sizeof(*fl6));
794 ipv6_addr_copy(&fl6->saddr, saddr);
795 ipv6_addr_copy(&fl6->daddr, daddr);
796 fl6->flowi6_proto = IPPROTO_ICMPV6;
797 fl6->fl6_icmp_type = type;
798 fl6->fl6_icmp_code = 0;
799 fl6->flowi6_oif = oif;
800 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
801}
802
803/*
804 * Special lock-class for __icmpv6_sk:
805 */
806static struct lock_class_key icmpv6_socket_sk_dst_lock_key;
807
808static int __net_init icmpv6_sk_init(struct net *net)
809{
810 struct sock *sk;
811 int err, i, j;
812
813 net->ipv6.icmp_sk =
814 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
815 if (net->ipv6.icmp_sk == NULL)
816 return -ENOMEM;
817
818 for_each_possible_cpu(i) {
819 err = inet_ctl_sock_create(&sk, PF_INET6,
820 SOCK_RAW, IPPROTO_ICMPV6, net);
821 if (err < 0) {
822 printk(KERN_ERR
823 "Failed to initialize the ICMP6 control socket "
824 "(err %d).\n",
825 err);
826 goto fail;
827 }
828
829 net->ipv6.icmp_sk[i] = sk;
830
831 /*
832 * Split off their lock-class, because sk->sk_dst_lock
833 * gets used from softirqs, which is safe for
834 * __icmpv6_sk (because those never get directly used
835 * via userspace syscalls), but unsafe for normal sockets.
836 */
837 lockdep_set_class(&sk->sk_dst_lock,
838 &icmpv6_socket_sk_dst_lock_key);
839
840 /* Enough space for 2 64K ICMP packets, including
841 * sk_buff struct overhead.
842 */
843 sk->sk_sndbuf =
844 (2 * ((64 * 1024) + sizeof(struct sk_buff)));
845 }
846 return 0;
847
848 fail:
849 for (j = 0; j < i; j++)
850 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
851 kfree(net->ipv6.icmp_sk);
852 return err;
853}
854
855static void __net_exit icmpv6_sk_exit(struct net *net)
856{
857 int i;
858
859 for_each_possible_cpu(i) {
860 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
861 }
862 kfree(net->ipv6.icmp_sk);
863}
864
865static struct pernet_operations icmpv6_sk_ops = {
866 .init = icmpv6_sk_init,
867 .exit = icmpv6_sk_exit,
868};
869
870int __init icmpv6_init(void)
871{
872 int err;
873
874 err = register_pernet_subsys(&icmpv6_sk_ops);
875 if (err < 0)
876 return err;
877
878 err = -EAGAIN;
879 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
880 goto fail;
881 return 0;
882
883fail:
884 printk(KERN_ERR "Failed to register ICMP6 protocol\n");
885 unregister_pernet_subsys(&icmpv6_sk_ops);
886 return err;
887}
888
889void icmpv6_cleanup(void)
890{
891 unregister_pernet_subsys(&icmpv6_sk_ops);
892 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
893}
894
895
896static const struct icmp6_err {
897 int err;
898 int fatal;
899} tab_unreach[] = {
900 { /* NOROUTE */
901 .err = ENETUNREACH,
902 .fatal = 0,
903 },
904 { /* ADM_PROHIBITED */
905 .err = EACCES,
906 .fatal = 1,
907 },
908 { /* Was NOT_NEIGHBOUR, now reserved */
909 .err = EHOSTUNREACH,
910 .fatal = 0,
911 },
912 { /* ADDR_UNREACH */
913 .err = EHOSTUNREACH,
914 .fatal = 0,
915 },
916 { /* PORT_UNREACH */
917 .err = ECONNREFUSED,
918 .fatal = 1,
919 },
920};
921
922int icmpv6_err_convert(u8 type, u8 code, int *err)
923{
924 int fatal = 0;
925
926 *err = EPROTO;
927
928 switch (type) {
929 case ICMPV6_DEST_UNREACH:
930 fatal = 1;
931 if (code <= ICMPV6_PORT_UNREACH) {
932 *err = tab_unreach[code].err;
933 fatal = tab_unreach[code].fatal;
934 }
935 break;
936
937 case ICMPV6_PKT_TOOBIG:
938 *err = EMSGSIZE;
939 break;
940
941 case ICMPV6_PARAMPROB:
942 *err = EPROTO;
943 fatal = 1;
944 break;
945
946 case ICMPV6_TIME_EXCEED:
947 *err = EHOSTUNREACH;
948 break;
949 }
950
951 return fatal;
952}
953
954EXPORT_SYMBOL(icmpv6_err_convert);
955
956#ifdef CONFIG_SYSCTL
957ctl_table ipv6_icmp_table_template[] = {
958 {
959 .procname = "ratelimit",
960 .data = &init_net.ipv6.sysctl.icmpv6_time,
961 .maxlen = sizeof(int),
962 .mode = 0644,
963 .proc_handler = proc_dointvec_ms_jiffies,
964 },
965 { },
966};
967
968struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
969{
970 struct ctl_table *table;
971
972 table = kmemdup(ipv6_icmp_table_template,
973 sizeof(ipv6_icmp_table_template),
974 GFP_KERNEL);
975
976 if (table)
977 table[0].data = &net->ipv6.sysctl.icmpv6_time;
978
979 return table;
980}
981#endif
982