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1/*
2 * Internet Control Message Protocol (ICMPv6)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on net/ipv4/icmp.c
9 *
10 * RFC 1885
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18/*
19 * Changes:
20 *
21 * Andi Kleen : exception handling
22 * Andi Kleen add rate limits. never reply to a icmp.
23 * add more length checks and other fixes.
24 * yoshfuji : ensure to sent parameter problem for
25 * fragments.
26 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
27 * Randy Dunlap and
28 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
29 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
30 */
31
32#define pr_fmt(fmt) "IPv6: " fmt
33
34#include <linux/module.h>
35#include <linux/errno.h>
36#include <linux/types.h>
37#include <linux/socket.h>
38#include <linux/in.h>
39#include <linux/kernel.h>
40#include <linux/sockios.h>
41#include <linux/net.h>
42#include <linux/skbuff.h>
43#include <linux/init.h>
44#include <linux/netfilter.h>
45#include <linux/slab.h>
46
47#ifdef CONFIG_SYSCTL
48#include <linux/sysctl.h>
49#endif
50
51#include <linux/inet.h>
52#include <linux/netdevice.h>
53#include <linux/icmpv6.h>
54
55#include <net/ip.h>
56#include <net/sock.h>
57
58#include <net/ipv6.h>
59#include <net/ip6_checksum.h>
60#include <net/ping.h>
61#include <net/protocol.h>
62#include <net/raw.h>
63#include <net/rawv6.h>
64#include <net/transp_v6.h>
65#include <net/ip6_route.h>
66#include <net/addrconf.h>
67#include <net/icmp.h>
68#include <net/xfrm.h>
69#include <net/inet_common.h>
70#include <net/dsfield.h>
71#include <net/l3mdev.h>
72
73#include <linux/uaccess.h>
74
75/*
76 * The ICMP socket(s). This is the most convenient way to flow control
77 * our ICMP output as well as maintain a clean interface throughout
78 * all layers. All Socketless IP sends will soon be gone.
79 *
80 * On SMP we have one ICMP socket per-cpu.
81 */
82static inline struct sock *icmpv6_sk(struct net *net)
83{
84 return net->ipv6.icmp_sk[smp_processor_id()];
85}
86
87static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
88 u8 type, u8 code, int offset, __be32 info)
89{
90 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
91 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
92 struct net *net = dev_net(skb->dev);
93
94 if (type == ICMPV6_PKT_TOOBIG)
95 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
96 else if (type == NDISC_REDIRECT)
97 ip6_redirect(skb, net, skb->dev->ifindex, 0,
98 sock_net_uid(net, NULL));
99
100 if (!(type & ICMPV6_INFOMSG_MASK))
101 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
102 ping_err(skb, offset, ntohl(info));
103}
104
105static int icmpv6_rcv(struct sk_buff *skb);
106
107static const struct inet6_protocol icmpv6_protocol = {
108 .handler = icmpv6_rcv,
109 .err_handler = icmpv6_err,
110 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
111};
112
113/* Called with BH disabled */
114static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
115{
116 struct sock *sk;
117
118 sk = icmpv6_sk(net);
119 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
120 /* This can happen if the output path (f.e. SIT or
121 * ip6ip6 tunnel) signals dst_link_failure() for an
122 * outgoing ICMP6 packet.
123 */
124 return NULL;
125 }
126 return sk;
127}
128
129static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
130{
131 spin_unlock(&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 || !(*tp & ICMPV6_INFOMSG_MASK))
164 return true;
165 }
166 return false;
167}
168
169static bool icmpv6_mask_allow(int type)
170{
171 /* Informational messages are not limited. */
172 if (type & ICMPV6_INFOMSG_MASK)
173 return true;
174
175 /* Do not limit pmtu discovery, it would break it. */
176 if (type == ICMPV6_PKT_TOOBIG)
177 return true;
178
179 return false;
180}
181
182static bool icmpv6_global_allow(int type)
183{
184 if (icmpv6_mask_allow(type))
185 return true;
186
187 if (icmp_global_allow())
188 return true;
189
190 return false;
191}
192
193/*
194 * Check the ICMP output rate limit
195 */
196static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
197 struct flowi6 *fl6)
198{
199 struct net *net = sock_net(sk);
200 struct dst_entry *dst;
201 bool res = false;
202
203 if (icmpv6_mask_allow(type))
204 return true;
205
206 /*
207 * Look up the output route.
208 * XXX: perhaps the expire for routing entries cloned by
209 * this lookup should be more aggressive (not longer than timeout).
210 */
211 dst = ip6_route_output(net, sk, fl6);
212 if (dst->error) {
213 IP6_INC_STATS(net, ip6_dst_idev(dst),
214 IPSTATS_MIB_OUTNOROUTES);
215 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
216 res = true;
217 } else {
218 struct rt6_info *rt = (struct rt6_info *)dst;
219 int tmo = net->ipv6.sysctl.icmpv6_time;
220 struct inet_peer *peer;
221
222 /* Give more bandwidth to wider prefixes. */
223 if (rt->rt6i_dst.plen < 128)
224 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
225
226 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
227 res = inet_peer_xrlim_allow(peer, tmo);
228 if (peer)
229 inet_putpeer(peer);
230 }
231 dst_release(dst);
232 return res;
233}
234
235/*
236 * an inline helper for the "simple" if statement below
237 * checks if parameter problem report is caused by an
238 * unrecognized IPv6 option that has the Option Type
239 * highest-order two bits set to 10
240 */
241
242static bool opt_unrec(struct sk_buff *skb, __u32 offset)
243{
244 u8 _optval, *op;
245
246 offset += skb_network_offset(skb);
247 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
248 if (!op)
249 return true;
250 return (*op & 0xC0) == 0x80;
251}
252
253void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
254 struct icmp6hdr *thdr, int len)
255{
256 struct sk_buff *skb;
257 struct icmp6hdr *icmp6h;
258
259 skb = skb_peek(&sk->sk_write_queue);
260 if (!skb)
261 return;
262
263 icmp6h = icmp6_hdr(skb);
264 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
265 icmp6h->icmp6_cksum = 0;
266
267 if (skb_queue_len(&sk->sk_write_queue) == 1) {
268 skb->csum = csum_partial(icmp6h,
269 sizeof(struct icmp6hdr), skb->csum);
270 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
271 &fl6->daddr,
272 len, fl6->flowi6_proto,
273 skb->csum);
274 } else {
275 __wsum tmp_csum = 0;
276
277 skb_queue_walk(&sk->sk_write_queue, skb) {
278 tmp_csum = csum_add(tmp_csum, skb->csum);
279 }
280
281 tmp_csum = csum_partial(icmp6h,
282 sizeof(struct icmp6hdr), tmp_csum);
283 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
284 &fl6->daddr,
285 len, fl6->flowi6_proto,
286 tmp_csum);
287 }
288 ip6_push_pending_frames(sk);
289}
290
291struct icmpv6_msg {
292 struct sk_buff *skb;
293 int offset;
294 uint8_t type;
295};
296
297static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
298{
299 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
300 struct sk_buff *org_skb = msg->skb;
301 __wsum csum = 0;
302
303 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
304 to, len, csum);
305 skb->csum = csum_block_add(skb->csum, csum, odd);
306 if (!(msg->type & ICMPV6_INFOMSG_MASK))
307 nf_ct_attach(skb, org_skb);
308 return 0;
309}
310
311#if IS_ENABLED(CONFIG_IPV6_MIP6)
312static void mip6_addr_swap(struct sk_buff *skb)
313{
314 struct ipv6hdr *iph = ipv6_hdr(skb);
315 struct inet6_skb_parm *opt = IP6CB(skb);
316 struct ipv6_destopt_hao *hao;
317 struct in6_addr tmp;
318 int off;
319
320 if (opt->dsthao) {
321 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
322 if (likely(off >= 0)) {
323 hao = (struct ipv6_destopt_hao *)
324 (skb_network_header(skb) + off);
325 tmp = iph->saddr;
326 iph->saddr = hao->addr;
327 hao->addr = tmp;
328 }
329 }
330}
331#else
332static inline void mip6_addr_swap(struct sk_buff *skb) {}
333#endif
334
335static struct dst_entry *icmpv6_route_lookup(struct net *net,
336 struct sk_buff *skb,
337 struct sock *sk,
338 struct flowi6 *fl6)
339{
340 struct dst_entry *dst, *dst2;
341 struct flowi6 fl2;
342 int err;
343
344 err = ip6_dst_lookup(net, sk, &dst, fl6);
345 if (err)
346 return ERR_PTR(err);
347
348 /*
349 * We won't send icmp if the destination is known
350 * anycast.
351 */
352 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
353 net_dbg_ratelimited("icmp6_send: acast source\n");
354 dst_release(dst);
355 return ERR_PTR(-EINVAL);
356 }
357
358 /* No need to clone since we're just using its address. */
359 dst2 = dst;
360
361 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
362 if (!IS_ERR(dst)) {
363 if (dst != dst2)
364 return dst;
365 } else {
366 if (PTR_ERR(dst) == -EPERM)
367 dst = NULL;
368 else
369 return dst;
370 }
371
372 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
373 if (err)
374 goto relookup_failed;
375
376 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
377 if (err)
378 goto relookup_failed;
379
380 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
381 if (!IS_ERR(dst2)) {
382 dst_release(dst);
383 dst = dst2;
384 } else {
385 err = PTR_ERR(dst2);
386 if (err == -EPERM) {
387 dst_release(dst);
388 return dst2;
389 } else
390 goto relookup_failed;
391 }
392
393relookup_failed:
394 if (dst)
395 return dst;
396 return ERR_PTR(err);
397}
398
399static int icmp6_iif(const struct sk_buff *skb)
400{
401 int iif = skb->dev->ifindex;
402
403 /* for local traffic to local address, skb dev is the loopback
404 * device. Check if there is a dst attached to the skb and if so
405 * get the real device index.
406 */
407 if (unlikely(iif == LOOPBACK_IFINDEX)) {
408 const struct rt6_info *rt6 = skb_rt6_info(skb);
409
410 if (rt6)
411 iif = rt6->rt6i_idev->dev->ifindex;
412 }
413
414 return iif;
415}
416
417/*
418 * Send an ICMP message in response to a packet in error
419 */
420static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
421 const struct in6_addr *force_saddr)
422{
423 struct net *net = dev_net(skb->dev);
424 struct inet6_dev *idev = NULL;
425 struct ipv6hdr *hdr = ipv6_hdr(skb);
426 struct sock *sk;
427 struct ipv6_pinfo *np;
428 const struct in6_addr *saddr = NULL;
429 struct dst_entry *dst;
430 struct icmp6hdr tmp_hdr;
431 struct flowi6 fl6;
432 struct icmpv6_msg msg;
433 struct sockcm_cookie sockc_unused = {0};
434 struct ipcm6_cookie ipc6;
435 int iif = 0;
436 int addr_type = 0;
437 int len;
438 u32 mark = IP6_REPLY_MARK(net, skb->mark);
439
440 if ((u8 *)hdr < skb->head ||
441 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
442 return;
443
444 /*
445 * Make sure we respect the rules
446 * i.e. RFC 1885 2.4(e)
447 * Rule (e.1) is enforced by not using icmp6_send
448 * in any code that processes icmp errors.
449 */
450 addr_type = ipv6_addr_type(&hdr->daddr);
451
452 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
453 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
454 saddr = &hdr->daddr;
455
456 /*
457 * Dest addr check
458 */
459
460 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
461 if (type != ICMPV6_PKT_TOOBIG &&
462 !(type == ICMPV6_PARAMPROB &&
463 code == ICMPV6_UNK_OPTION &&
464 (opt_unrec(skb, info))))
465 return;
466
467 saddr = NULL;
468 }
469
470 addr_type = ipv6_addr_type(&hdr->saddr);
471
472 /*
473 * Source addr check
474 */
475
476 if (__ipv6_addr_needs_scope_id(addr_type)) {
477 iif = icmp6_iif(skb);
478 } else {
479 dst = skb_dst(skb);
480 iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
481 }
482
483 /*
484 * Must not send error if the source does not uniquely
485 * identify a single node (RFC2463 Section 2.4).
486 * We check unspecified / multicast addresses here,
487 * and anycast addresses will be checked later.
488 */
489 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
490 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
491 &hdr->saddr, &hdr->daddr);
492 return;
493 }
494
495 /*
496 * Never answer to a ICMP packet.
497 */
498 if (is_ineligible(skb)) {
499 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
500 &hdr->saddr, &hdr->daddr);
501 return;
502 }
503
504 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
505 local_bh_disable();
506
507 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
508 if (!(skb->dev->flags&IFF_LOOPBACK) && !icmpv6_global_allow(type))
509 goto out_bh_enable;
510
511 mip6_addr_swap(skb);
512
513 memset(&fl6, 0, sizeof(fl6));
514 fl6.flowi6_proto = IPPROTO_ICMPV6;
515 fl6.daddr = hdr->saddr;
516 if (force_saddr)
517 saddr = force_saddr;
518 if (saddr)
519 fl6.saddr = *saddr;
520 fl6.flowi6_mark = mark;
521 fl6.flowi6_oif = iif;
522 fl6.fl6_icmp_type = type;
523 fl6.fl6_icmp_code = code;
524 fl6.flowi6_uid = sock_net_uid(net, NULL);
525 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
526 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
527
528 sk = icmpv6_xmit_lock(net);
529 if (!sk)
530 goto out_bh_enable;
531
532 sk->sk_mark = mark;
533 np = inet6_sk(sk);
534
535 if (!icmpv6_xrlim_allow(sk, type, &fl6))
536 goto out;
537
538 tmp_hdr.icmp6_type = type;
539 tmp_hdr.icmp6_code = code;
540 tmp_hdr.icmp6_cksum = 0;
541 tmp_hdr.icmp6_pointer = htonl(info);
542
543 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
544 fl6.flowi6_oif = np->mcast_oif;
545 else if (!fl6.flowi6_oif)
546 fl6.flowi6_oif = np->ucast_oif;
547
548 ipc6.tclass = np->tclass;
549 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
550
551 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
552 if (IS_ERR(dst))
553 goto out;
554
555 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
556 ipc6.dontfrag = np->dontfrag;
557 ipc6.opt = NULL;
558
559 msg.skb = skb;
560 msg.offset = skb_network_offset(skb);
561 msg.type = type;
562
563 len = skb->len - msg.offset;
564 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
565 if (len < 0) {
566 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
567 &hdr->saddr, &hdr->daddr);
568 goto out_dst_release;
569 }
570
571 rcu_read_lock();
572 idev = __in6_dev_get(skb->dev);
573
574 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
575 len + sizeof(struct icmp6hdr),
576 sizeof(struct icmp6hdr),
577 &ipc6, &fl6, (struct rt6_info *)dst,
578 MSG_DONTWAIT, &sockc_unused)) {
579 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
580 ip6_flush_pending_frames(sk);
581 } else {
582 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
583 len + sizeof(struct icmp6hdr));
584 }
585 rcu_read_unlock();
586out_dst_release:
587 dst_release(dst);
588out:
589 icmpv6_xmit_unlock(sk);
590out_bh_enable:
591 local_bh_enable();
592}
593
594/* Slightly more convenient version of icmp6_send.
595 */
596void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
597{
598 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
599 kfree_skb(skb);
600}
601
602/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
603 * if sufficient data bytes are available
604 * @nhs is the size of the tunnel header(s) :
605 * Either an IPv4 header for SIT encap
606 * an IPv4 header + GRE header for GRE encap
607 */
608int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
609 unsigned int data_len)
610{
611 struct in6_addr temp_saddr;
612 struct rt6_info *rt;
613 struct sk_buff *skb2;
614 u32 info = 0;
615
616 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
617 return 1;
618
619 /* RFC 4884 (partial) support for ICMP extensions */
620 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
621 data_len = 0;
622
623 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
624
625 if (!skb2)
626 return 1;
627
628 skb_dst_drop(skb2);
629 skb_pull(skb2, nhs);
630 skb_reset_network_header(skb2);
631
632 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
633 skb, 0);
634
635 if (rt && rt->dst.dev)
636 skb2->dev = rt->dst.dev;
637
638 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
639
640 if (data_len) {
641 /* RFC 4884 (partial) support :
642 * insert 0 padding at the end, before the extensions
643 */
644 __skb_push(skb2, nhs);
645 skb_reset_network_header(skb2);
646 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
647 memset(skb2->data + data_len - nhs, 0, nhs);
648 /* RFC 4884 4.5 : Length is measured in 64-bit words,
649 * and stored in reserved[0]
650 */
651 info = (data_len/8) << 24;
652 }
653 if (type == ICMP_TIME_EXCEEDED)
654 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
655 info, &temp_saddr);
656 else
657 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
658 info, &temp_saddr);
659 if (rt)
660 ip6_rt_put(rt);
661
662 kfree_skb(skb2);
663
664 return 0;
665}
666EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
667
668static void icmpv6_echo_reply(struct sk_buff *skb)
669{
670 struct net *net = dev_net(skb->dev);
671 struct sock *sk;
672 struct inet6_dev *idev;
673 struct ipv6_pinfo *np;
674 const struct in6_addr *saddr = NULL;
675 struct icmp6hdr *icmph = icmp6_hdr(skb);
676 struct icmp6hdr tmp_hdr;
677 struct flowi6 fl6;
678 struct icmpv6_msg msg;
679 struct dst_entry *dst;
680 struct ipcm6_cookie ipc6;
681 u32 mark = IP6_REPLY_MARK(net, skb->mark);
682 struct sockcm_cookie sockc_unused = {0};
683
684 saddr = &ipv6_hdr(skb)->daddr;
685
686 if (!ipv6_unicast_destination(skb) &&
687 !(net->ipv6.sysctl.anycast_src_echo_reply &&
688 ipv6_anycast_destination(skb_dst(skb), saddr)))
689 saddr = NULL;
690
691 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
692 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
693
694 memset(&fl6, 0, sizeof(fl6));
695 fl6.flowi6_proto = IPPROTO_ICMPV6;
696 fl6.daddr = ipv6_hdr(skb)->saddr;
697 if (saddr)
698 fl6.saddr = *saddr;
699 fl6.flowi6_oif = icmp6_iif(skb);
700 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
701 fl6.flowi6_mark = mark;
702 fl6.flowi6_uid = sock_net_uid(net, NULL);
703 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
704
705 local_bh_disable();
706 sk = icmpv6_xmit_lock(net);
707 if (!sk)
708 goto out_bh_enable;
709 sk->sk_mark = mark;
710 np = inet6_sk(sk);
711
712 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
713 fl6.flowi6_oif = np->mcast_oif;
714 else if (!fl6.flowi6_oif)
715 fl6.flowi6_oif = np->ucast_oif;
716
717 if (ip6_dst_lookup(net, sk, &dst, &fl6))
718 goto out;
719 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
720 if (IS_ERR(dst))
721 goto out;
722
723 idev = __in6_dev_get(skb->dev);
724
725 msg.skb = skb;
726 msg.offset = 0;
727 msg.type = ICMPV6_ECHO_REPLY;
728
729 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
730 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
731 ipc6.dontfrag = np->dontfrag;
732 ipc6.opt = NULL;
733
734 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
735 skb->len + sizeof(struct icmp6hdr),
736 sizeof(struct icmp6hdr), &ipc6, &fl6,
737 (struct rt6_info *)dst, MSG_DONTWAIT,
738 &sockc_unused)) {
739 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
740 ip6_flush_pending_frames(sk);
741 } else {
742 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
743 skb->len + sizeof(struct icmp6hdr));
744 }
745 dst_release(dst);
746out:
747 icmpv6_xmit_unlock(sk);
748out_bh_enable:
749 local_bh_enable();
750}
751
752void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
753{
754 const struct inet6_protocol *ipprot;
755 int inner_offset;
756 __be16 frag_off;
757 u8 nexthdr;
758 struct net *net = dev_net(skb->dev);
759
760 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
761 goto out;
762
763 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
764 if (ipv6_ext_hdr(nexthdr)) {
765 /* now skip over extension headers */
766 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
767 &nexthdr, &frag_off);
768 if (inner_offset < 0)
769 goto out;
770 } else {
771 inner_offset = sizeof(struct ipv6hdr);
772 }
773
774 /* Checkin header including 8 bytes of inner protocol header. */
775 if (!pskb_may_pull(skb, inner_offset+8))
776 goto out;
777
778 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
779 Without this we will not able f.e. to make source routed
780 pmtu discovery.
781 Corresponding argument (opt) to notifiers is already added.
782 --ANK (980726)
783 */
784
785 ipprot = rcu_dereference(inet6_protos[nexthdr]);
786 if (ipprot && ipprot->err_handler)
787 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
788
789 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
790 return;
791
792out:
793 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
794}
795
796/*
797 * Handle icmp messages
798 */
799
800static int icmpv6_rcv(struct sk_buff *skb)
801{
802 struct net_device *dev = skb->dev;
803 struct inet6_dev *idev = __in6_dev_get(dev);
804 const struct in6_addr *saddr, *daddr;
805 struct icmp6hdr *hdr;
806 u8 type;
807 bool success = false;
808
809 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
810 struct sec_path *sp = skb_sec_path(skb);
811 int nh;
812
813 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
814 XFRM_STATE_ICMP))
815 goto drop_no_count;
816
817 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
818 goto drop_no_count;
819
820 nh = skb_network_offset(skb);
821 skb_set_network_header(skb, sizeof(*hdr));
822
823 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
824 goto drop_no_count;
825
826 skb_set_network_header(skb, nh);
827 }
828
829 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
830
831 saddr = &ipv6_hdr(skb)->saddr;
832 daddr = &ipv6_hdr(skb)->daddr;
833
834 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
835 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
836 saddr, daddr);
837 goto csum_error;
838 }
839
840 if (!pskb_pull(skb, sizeof(*hdr)))
841 goto discard_it;
842
843 hdr = icmp6_hdr(skb);
844
845 type = hdr->icmp6_type;
846
847 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
848
849 switch (type) {
850 case ICMPV6_ECHO_REQUEST:
851 icmpv6_echo_reply(skb);
852 break;
853
854 case ICMPV6_ECHO_REPLY:
855 success = ping_rcv(skb);
856 break;
857
858 case ICMPV6_PKT_TOOBIG:
859 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
860 standard destination cache. Seems, only "advanced"
861 destination cache will allow to solve this problem
862 --ANK (980726)
863 */
864 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
865 goto discard_it;
866 hdr = icmp6_hdr(skb);
867
868 /* to notify */
869 /* fall through */
870 case ICMPV6_DEST_UNREACH:
871 case ICMPV6_TIME_EXCEED:
872 case ICMPV6_PARAMPROB:
873 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
874 break;
875
876 case NDISC_ROUTER_SOLICITATION:
877 case NDISC_ROUTER_ADVERTISEMENT:
878 case NDISC_NEIGHBOUR_SOLICITATION:
879 case NDISC_NEIGHBOUR_ADVERTISEMENT:
880 case NDISC_REDIRECT:
881 ndisc_rcv(skb);
882 break;
883
884 case ICMPV6_MGM_QUERY:
885 igmp6_event_query(skb);
886 break;
887
888 case ICMPV6_MGM_REPORT:
889 igmp6_event_report(skb);
890 break;
891
892 case ICMPV6_MGM_REDUCTION:
893 case ICMPV6_NI_QUERY:
894 case ICMPV6_NI_REPLY:
895 case ICMPV6_MLD2_REPORT:
896 case ICMPV6_DHAAD_REQUEST:
897 case ICMPV6_DHAAD_REPLY:
898 case ICMPV6_MOBILE_PREFIX_SOL:
899 case ICMPV6_MOBILE_PREFIX_ADV:
900 break;
901
902 default:
903 /* informational */
904 if (type & ICMPV6_INFOMSG_MASK)
905 break;
906
907 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
908 saddr, daddr);
909
910 /*
911 * error of unknown type.
912 * must pass to upper level
913 */
914
915 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
916 }
917
918 /* until the v6 path can be better sorted assume failure and
919 * preserve the status quo behaviour for the rest of the paths to here
920 */
921 if (success)
922 consume_skb(skb);
923 else
924 kfree_skb(skb);
925
926 return 0;
927
928csum_error:
929 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
930discard_it:
931 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
932drop_no_count:
933 kfree_skb(skb);
934 return 0;
935}
936
937void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
938 u8 type,
939 const struct in6_addr *saddr,
940 const struct in6_addr *daddr,
941 int oif)
942{
943 memset(fl6, 0, sizeof(*fl6));
944 fl6->saddr = *saddr;
945 fl6->daddr = *daddr;
946 fl6->flowi6_proto = IPPROTO_ICMPV6;
947 fl6->fl6_icmp_type = type;
948 fl6->fl6_icmp_code = 0;
949 fl6->flowi6_oif = oif;
950 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
951}
952
953static int __net_init icmpv6_sk_init(struct net *net)
954{
955 struct sock *sk;
956 int err, i, j;
957
958 net->ipv6.icmp_sk =
959 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
960 if (!net->ipv6.icmp_sk)
961 return -ENOMEM;
962
963 for_each_possible_cpu(i) {
964 err = inet_ctl_sock_create(&sk, PF_INET6,
965 SOCK_RAW, IPPROTO_ICMPV6, net);
966 if (err < 0) {
967 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
968 err);
969 goto fail;
970 }
971
972 net->ipv6.icmp_sk[i] = sk;
973
974 /* Enough space for 2 64K ICMP packets, including
975 * sk_buff struct overhead.
976 */
977 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
978 }
979 return 0;
980
981 fail:
982 for (j = 0; j < i; j++)
983 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
984 kfree(net->ipv6.icmp_sk);
985 return err;
986}
987
988static void __net_exit icmpv6_sk_exit(struct net *net)
989{
990 int i;
991
992 for_each_possible_cpu(i) {
993 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
994 }
995 kfree(net->ipv6.icmp_sk);
996}
997
998static struct pernet_operations icmpv6_sk_ops = {
999 .init = icmpv6_sk_init,
1000 .exit = icmpv6_sk_exit,
1001};
1002
1003int __init icmpv6_init(void)
1004{
1005 int err;
1006
1007 err = register_pernet_subsys(&icmpv6_sk_ops);
1008 if (err < 0)
1009 return err;
1010
1011 err = -EAGAIN;
1012 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1013 goto fail;
1014
1015 err = inet6_register_icmp_sender(icmp6_send);
1016 if (err)
1017 goto sender_reg_err;
1018 return 0;
1019
1020sender_reg_err:
1021 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1022fail:
1023 pr_err("Failed to register ICMP6 protocol\n");
1024 unregister_pernet_subsys(&icmpv6_sk_ops);
1025 return err;
1026}
1027
1028void icmpv6_cleanup(void)
1029{
1030 inet6_unregister_icmp_sender(icmp6_send);
1031 unregister_pernet_subsys(&icmpv6_sk_ops);
1032 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1033}
1034
1035
1036static const struct icmp6_err {
1037 int err;
1038 int fatal;
1039} tab_unreach[] = {
1040 { /* NOROUTE */
1041 .err = ENETUNREACH,
1042 .fatal = 0,
1043 },
1044 { /* ADM_PROHIBITED */
1045 .err = EACCES,
1046 .fatal = 1,
1047 },
1048 { /* Was NOT_NEIGHBOUR, now reserved */
1049 .err = EHOSTUNREACH,
1050 .fatal = 0,
1051 },
1052 { /* ADDR_UNREACH */
1053 .err = EHOSTUNREACH,
1054 .fatal = 0,
1055 },
1056 { /* PORT_UNREACH */
1057 .err = ECONNREFUSED,
1058 .fatal = 1,
1059 },
1060 { /* POLICY_FAIL */
1061 .err = EACCES,
1062 .fatal = 1,
1063 },
1064 { /* REJECT_ROUTE */
1065 .err = EACCES,
1066 .fatal = 1,
1067 },
1068};
1069
1070int icmpv6_err_convert(u8 type, u8 code, int *err)
1071{
1072 int fatal = 0;
1073
1074 *err = EPROTO;
1075
1076 switch (type) {
1077 case ICMPV6_DEST_UNREACH:
1078 fatal = 1;
1079 if (code < ARRAY_SIZE(tab_unreach)) {
1080 *err = tab_unreach[code].err;
1081 fatal = tab_unreach[code].fatal;
1082 }
1083 break;
1084
1085 case ICMPV6_PKT_TOOBIG:
1086 *err = EMSGSIZE;
1087 break;
1088
1089 case ICMPV6_PARAMPROB:
1090 *err = EPROTO;
1091 fatal = 1;
1092 break;
1093
1094 case ICMPV6_TIME_EXCEED:
1095 *err = EHOSTUNREACH;
1096 break;
1097 }
1098
1099 return fatal;
1100}
1101EXPORT_SYMBOL(icmpv6_err_convert);
1102
1103#ifdef CONFIG_SYSCTL
1104static struct ctl_table ipv6_icmp_table_template[] = {
1105 {
1106 .procname = "ratelimit",
1107 .data = &init_net.ipv6.sysctl.icmpv6_time,
1108 .maxlen = sizeof(int),
1109 .mode = 0644,
1110 .proc_handler = proc_dointvec_ms_jiffies,
1111 },
1112 { },
1113};
1114
1115struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1116{
1117 struct ctl_table *table;
1118
1119 table = kmemdup(ipv6_icmp_table_template,
1120 sizeof(ipv6_icmp_table_template),
1121 GFP_KERNEL);
1122
1123 if (table)
1124 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1125
1126 return table;
1127}
1128#endif
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Internet Control Message Protocol (ICMPv6)
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on net/ipv4/icmp.c
10 *
11 * RFC 1885
12 */
13
14/*
15 * Changes:
16 *
17 * Andi Kleen : exception handling
18 * Andi Kleen add rate limits. never reply to a icmp.
19 * add more length checks and other fixes.
20 * yoshfuji : ensure to sent parameter problem for
21 * fragments.
22 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
23 * Randy Dunlap and
24 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
25 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
26 */
27
28#define pr_fmt(fmt) "IPv6: " fmt
29
30#include <linux/module.h>
31#include <linux/errno.h>
32#include <linux/types.h>
33#include <linux/socket.h>
34#include <linux/in.h>
35#include <linux/kernel.h>
36#include <linux/sockios.h>
37#include <linux/net.h>
38#include <linux/skbuff.h>
39#include <linux/init.h>
40#include <linux/netfilter.h>
41#include <linux/slab.h>
42
43#ifdef CONFIG_SYSCTL
44#include <linux/sysctl.h>
45#endif
46
47#include <linux/inet.h>
48#include <linux/netdevice.h>
49#include <linux/icmpv6.h>
50
51#include <net/ip.h>
52#include <net/sock.h>
53
54#include <net/ipv6.h>
55#include <net/ip6_checksum.h>
56#include <net/ping.h>
57#include <net/protocol.h>
58#include <net/raw.h>
59#include <net/rawv6.h>
60#include <net/transp_v6.h>
61#include <net/ip6_route.h>
62#include <net/addrconf.h>
63#include <net/icmp.h>
64#include <net/xfrm.h>
65#include <net/inet_common.h>
66#include <net/dsfield.h>
67#include <net/l3mdev.h>
68
69#include <linux/uaccess.h>
70
71/*
72 * The ICMP socket(s). This is the most convenient way to flow control
73 * our ICMP output as well as maintain a clean interface throughout
74 * all layers. All Socketless IP sends will soon be gone.
75 *
76 * On SMP we have one ICMP socket per-cpu.
77 */
78static struct sock *icmpv6_sk(struct net *net)
79{
80 return this_cpu_read(*net->ipv6.icmp_sk);
81}
82
83static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
84 u8 type, u8 code, int offset, __be32 info)
85{
86 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
87 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
88 struct net *net = dev_net(skb->dev);
89
90 if (type == ICMPV6_PKT_TOOBIG)
91 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
92 else if (type == NDISC_REDIRECT)
93 ip6_redirect(skb, net, skb->dev->ifindex, 0,
94 sock_net_uid(net, NULL));
95
96 if (!(type & ICMPV6_INFOMSG_MASK))
97 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
98 ping_err(skb, offset, ntohl(info));
99
100 return 0;
101}
102
103static int icmpv6_rcv(struct sk_buff *skb);
104
105static const struct inet6_protocol icmpv6_protocol = {
106 .handler = icmpv6_rcv,
107 .err_handler = icmpv6_err,
108 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
109};
110
111/* Called with BH disabled */
112static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
113{
114 struct sock *sk;
115
116 sk = icmpv6_sk(net);
117 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
118 /* This can happen if the output path (f.e. SIT or
119 * ip6ip6 tunnel) signals dst_link_failure() for an
120 * outgoing ICMP6 packet.
121 */
122 return NULL;
123 }
124 return sk;
125}
126
127static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
128{
129 spin_unlock(&sk->sk_lock.slock);
130}
131
132/*
133 * Figure out, may we reply to this packet with icmp error.
134 *
135 * We do not reply, if:
136 * - it was icmp error message.
137 * - it is truncated, so that it is known, that protocol is ICMPV6
138 * (i.e. in the middle of some exthdr)
139 *
140 * --ANK (980726)
141 */
142
143static bool is_ineligible(const struct sk_buff *skb)
144{
145 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
146 int len = skb->len - ptr;
147 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
148 __be16 frag_off;
149
150 if (len < 0)
151 return true;
152
153 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
154 if (ptr < 0)
155 return false;
156 if (nexthdr == IPPROTO_ICMPV6) {
157 u8 _type, *tp;
158 tp = skb_header_pointer(skb,
159 ptr+offsetof(struct icmp6hdr, icmp6_type),
160 sizeof(_type), &_type);
161 if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
162 return true;
163 }
164 return false;
165}
166
167static bool icmpv6_mask_allow(struct net *net, int type)
168{
169 if (type > ICMPV6_MSG_MAX)
170 return true;
171
172 /* Limit if icmp type is set in ratemask. */
173 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
174 return true;
175
176 return false;
177}
178
179static bool icmpv6_global_allow(struct net *net, int type)
180{
181 if (icmpv6_mask_allow(net, type))
182 return true;
183
184 if (icmp_global_allow())
185 return true;
186
187 return false;
188}
189
190/*
191 * Check the ICMP output rate limit
192 */
193static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
194 struct flowi6 *fl6)
195{
196 struct net *net = sock_net(sk);
197 struct dst_entry *dst;
198 bool res = false;
199
200 if (icmpv6_mask_allow(net, type))
201 return true;
202
203 /*
204 * Look up the output route.
205 * XXX: perhaps the expire for routing entries cloned by
206 * this lookup should be more aggressive (not longer than timeout).
207 */
208 dst = ip6_route_output(net, sk, fl6);
209 if (dst->error) {
210 IP6_INC_STATS(net, ip6_dst_idev(dst),
211 IPSTATS_MIB_OUTNOROUTES);
212 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
213 res = true;
214 } else {
215 struct rt6_info *rt = (struct rt6_info *)dst;
216 int tmo = net->ipv6.sysctl.icmpv6_time;
217 struct inet_peer *peer;
218
219 /* Give more bandwidth to wider prefixes. */
220 if (rt->rt6i_dst.plen < 128)
221 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
222
223 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
224 res = inet_peer_xrlim_allow(peer, tmo);
225 if (peer)
226 inet_putpeer(peer);
227 }
228 dst_release(dst);
229 return res;
230}
231
232static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type,
233 struct flowi6 *fl6)
234{
235 struct net *net = sock_net(sk);
236 struct dst_entry *dst;
237 bool res = false;
238
239 dst = ip6_route_output(net, sk, fl6);
240 if (!dst->error) {
241 struct rt6_info *rt = (struct rt6_info *)dst;
242 struct in6_addr prefsrc;
243
244 rt6_get_prefsrc(rt, &prefsrc);
245 res = !ipv6_addr_any(&prefsrc);
246 }
247 dst_release(dst);
248 return res;
249}
250
251/*
252 * an inline helper for the "simple" if statement below
253 * checks if parameter problem report is caused by an
254 * unrecognized IPv6 option that has the Option Type
255 * highest-order two bits set to 10
256 */
257
258static bool opt_unrec(struct sk_buff *skb, __u32 offset)
259{
260 u8 _optval, *op;
261
262 offset += skb_network_offset(skb);
263 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
264 if (!op)
265 return true;
266 return (*op & 0xC0) == 0x80;
267}
268
269void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
270 struct icmp6hdr *thdr, int len)
271{
272 struct sk_buff *skb;
273 struct icmp6hdr *icmp6h;
274
275 skb = skb_peek(&sk->sk_write_queue);
276 if (!skb)
277 return;
278
279 icmp6h = icmp6_hdr(skb);
280 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
281 icmp6h->icmp6_cksum = 0;
282
283 if (skb_queue_len(&sk->sk_write_queue) == 1) {
284 skb->csum = csum_partial(icmp6h,
285 sizeof(struct icmp6hdr), skb->csum);
286 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
287 &fl6->daddr,
288 len, fl6->flowi6_proto,
289 skb->csum);
290 } else {
291 __wsum tmp_csum = 0;
292
293 skb_queue_walk(&sk->sk_write_queue, skb) {
294 tmp_csum = csum_add(tmp_csum, skb->csum);
295 }
296
297 tmp_csum = csum_partial(icmp6h,
298 sizeof(struct icmp6hdr), tmp_csum);
299 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
300 &fl6->daddr,
301 len, fl6->flowi6_proto,
302 tmp_csum);
303 }
304 ip6_push_pending_frames(sk);
305}
306
307struct icmpv6_msg {
308 struct sk_buff *skb;
309 int offset;
310 uint8_t type;
311};
312
313static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
314{
315 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
316 struct sk_buff *org_skb = msg->skb;
317 __wsum csum = 0;
318
319 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
320 to, len, csum);
321 skb->csum = csum_block_add(skb->csum, csum, odd);
322 if (!(msg->type & ICMPV6_INFOMSG_MASK))
323 nf_ct_attach(skb, org_skb);
324 return 0;
325}
326
327#if IS_ENABLED(CONFIG_IPV6_MIP6)
328static void mip6_addr_swap(struct sk_buff *skb)
329{
330 struct ipv6hdr *iph = ipv6_hdr(skb);
331 struct inet6_skb_parm *opt = IP6CB(skb);
332 struct ipv6_destopt_hao *hao;
333 struct in6_addr tmp;
334 int off;
335
336 if (opt->dsthao) {
337 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
338 if (likely(off >= 0)) {
339 hao = (struct ipv6_destopt_hao *)
340 (skb_network_header(skb) + off);
341 tmp = iph->saddr;
342 iph->saddr = hao->addr;
343 hao->addr = tmp;
344 }
345 }
346}
347#else
348static inline void mip6_addr_swap(struct sk_buff *skb) {}
349#endif
350
351static struct dst_entry *icmpv6_route_lookup(struct net *net,
352 struct sk_buff *skb,
353 struct sock *sk,
354 struct flowi6 *fl6)
355{
356 struct dst_entry *dst, *dst2;
357 struct flowi6 fl2;
358 int err;
359
360 err = ip6_dst_lookup(net, sk, &dst, fl6);
361 if (err)
362 return ERR_PTR(err);
363
364 /*
365 * We won't send icmp if the destination is known
366 * anycast.
367 */
368 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
369 net_dbg_ratelimited("icmp6_send: acast source\n");
370 dst_release(dst);
371 return ERR_PTR(-EINVAL);
372 }
373
374 /* No need to clone since we're just using its address. */
375 dst2 = dst;
376
377 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
378 if (!IS_ERR(dst)) {
379 if (dst != dst2)
380 return dst;
381 } else {
382 if (PTR_ERR(dst) == -EPERM)
383 dst = NULL;
384 else
385 return dst;
386 }
387
388 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
389 if (err)
390 goto relookup_failed;
391
392 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
393 if (err)
394 goto relookup_failed;
395
396 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
397 if (!IS_ERR(dst2)) {
398 dst_release(dst);
399 dst = dst2;
400 } else {
401 err = PTR_ERR(dst2);
402 if (err == -EPERM) {
403 dst_release(dst);
404 return dst2;
405 } else
406 goto relookup_failed;
407 }
408
409relookup_failed:
410 if (dst)
411 return dst;
412 return ERR_PTR(err);
413}
414
415static struct net_device *icmp6_dev(const struct sk_buff *skb)
416{
417 struct net_device *dev = skb->dev;
418
419 /* for local traffic to local address, skb dev is the loopback
420 * device. Check if there is a dst attached to the skb and if so
421 * get the real device index. Same is needed for replies to a link
422 * local address on a device enslaved to an L3 master device
423 */
424 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
425 const struct rt6_info *rt6 = skb_rt6_info(skb);
426
427 if (rt6)
428 dev = rt6->rt6i_idev->dev;
429 }
430
431 return dev;
432}
433
434static int icmp6_iif(const struct sk_buff *skb)
435{
436 return icmp6_dev(skb)->ifindex;
437}
438
439/*
440 * Send an ICMP message in response to a packet in error
441 */
442void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
443 const struct in6_addr *force_saddr)
444{
445 struct inet6_dev *idev = NULL;
446 struct ipv6hdr *hdr = ipv6_hdr(skb);
447 struct sock *sk;
448 struct net *net;
449 struct ipv6_pinfo *np;
450 const struct in6_addr *saddr = NULL;
451 struct dst_entry *dst;
452 struct icmp6hdr tmp_hdr;
453 struct flowi6 fl6;
454 struct icmpv6_msg msg;
455 struct ipcm6_cookie ipc6;
456 int iif = 0;
457 int addr_type = 0;
458 int len;
459 u32 mark;
460
461 if ((u8 *)hdr < skb->head ||
462 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
463 return;
464
465 if (!skb->dev)
466 return;
467 net = dev_net(skb->dev);
468 mark = IP6_REPLY_MARK(net, skb->mark);
469 /*
470 * Make sure we respect the rules
471 * i.e. RFC 1885 2.4(e)
472 * Rule (e.1) is enforced by not using icmp6_send
473 * in any code that processes icmp errors.
474 */
475 addr_type = ipv6_addr_type(&hdr->daddr);
476
477 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
478 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
479 saddr = &hdr->daddr;
480
481 /*
482 * Dest addr check
483 */
484
485 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
486 if (type != ICMPV6_PKT_TOOBIG &&
487 !(type == ICMPV6_PARAMPROB &&
488 code == ICMPV6_UNK_OPTION &&
489 (opt_unrec(skb, info))))
490 return;
491
492 saddr = NULL;
493 }
494
495 addr_type = ipv6_addr_type(&hdr->saddr);
496
497 /*
498 * Source addr check
499 */
500
501 if (__ipv6_addr_needs_scope_id(addr_type)) {
502 iif = icmp6_iif(skb);
503 } else {
504 dst = skb_dst(skb);
505 iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
506 }
507
508 /*
509 * Must not send error if the source does not uniquely
510 * identify a single node (RFC2463 Section 2.4).
511 * We check unspecified / multicast addresses here,
512 * and anycast addresses will be checked later.
513 */
514 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
515 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
516 &hdr->saddr, &hdr->daddr);
517 return;
518 }
519
520 /*
521 * Never answer to a ICMP packet.
522 */
523 if (is_ineligible(skb)) {
524 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
525 &hdr->saddr, &hdr->daddr);
526 return;
527 }
528
529 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
530 local_bh_disable();
531
532 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
533 if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
534 goto out_bh_enable;
535
536 mip6_addr_swap(skb);
537
538 sk = icmpv6_xmit_lock(net);
539 if (!sk)
540 goto out_bh_enable;
541
542 memset(&fl6, 0, sizeof(fl6));
543 fl6.flowi6_proto = IPPROTO_ICMPV6;
544 fl6.daddr = hdr->saddr;
545 if (force_saddr)
546 saddr = force_saddr;
547 if (saddr) {
548 fl6.saddr = *saddr;
549 } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) {
550 /* select a more meaningful saddr from input if */
551 struct net_device *in_netdev;
552
553 in_netdev = dev_get_by_index(net, IP6CB(skb)->iif);
554 if (in_netdev) {
555 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
556 inet6_sk(sk)->srcprefs,
557 &fl6.saddr);
558 dev_put(in_netdev);
559 }
560 }
561 fl6.flowi6_mark = mark;
562 fl6.flowi6_oif = iif;
563 fl6.fl6_icmp_type = type;
564 fl6.fl6_icmp_code = code;
565 fl6.flowi6_uid = sock_net_uid(net, NULL);
566 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
567 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
568
569 np = inet6_sk(sk);
570
571 if (!icmpv6_xrlim_allow(sk, type, &fl6))
572 goto out;
573
574 tmp_hdr.icmp6_type = type;
575 tmp_hdr.icmp6_code = code;
576 tmp_hdr.icmp6_cksum = 0;
577 tmp_hdr.icmp6_pointer = htonl(info);
578
579 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
580 fl6.flowi6_oif = np->mcast_oif;
581 else if (!fl6.flowi6_oif)
582 fl6.flowi6_oif = np->ucast_oif;
583
584 ipcm6_init_sk(&ipc6, np);
585 ipc6.sockc.mark = mark;
586 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
587
588 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
589 if (IS_ERR(dst))
590 goto out;
591
592 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
593
594 msg.skb = skb;
595 msg.offset = skb_network_offset(skb);
596 msg.type = type;
597
598 len = skb->len - msg.offset;
599 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
600 if (len < 0) {
601 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
602 &hdr->saddr, &hdr->daddr);
603 goto out_dst_release;
604 }
605
606 rcu_read_lock();
607 idev = __in6_dev_get(skb->dev);
608
609 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
610 len + sizeof(struct icmp6hdr),
611 sizeof(struct icmp6hdr),
612 &ipc6, &fl6, (struct rt6_info *)dst,
613 MSG_DONTWAIT)) {
614 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
615 ip6_flush_pending_frames(sk);
616 } else {
617 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
618 len + sizeof(struct icmp6hdr));
619 }
620 rcu_read_unlock();
621out_dst_release:
622 dst_release(dst);
623out:
624 icmpv6_xmit_unlock(sk);
625out_bh_enable:
626 local_bh_enable();
627}
628EXPORT_SYMBOL(icmp6_send);
629
630/* Slightly more convenient version of icmp6_send.
631 */
632void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
633{
634 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
635 kfree_skb(skb);
636}
637
638/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
639 * if sufficient data bytes are available
640 * @nhs is the size of the tunnel header(s) :
641 * Either an IPv4 header for SIT encap
642 * an IPv4 header + GRE header for GRE encap
643 */
644int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
645 unsigned int data_len)
646{
647 struct in6_addr temp_saddr;
648 struct rt6_info *rt;
649 struct sk_buff *skb2;
650 u32 info = 0;
651
652 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
653 return 1;
654
655 /* RFC 4884 (partial) support for ICMP extensions */
656 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
657 data_len = 0;
658
659 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
660
661 if (!skb2)
662 return 1;
663
664 skb_dst_drop(skb2);
665 skb_pull(skb2, nhs);
666 skb_reset_network_header(skb2);
667
668 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
669 skb, 0);
670
671 if (rt && rt->dst.dev)
672 skb2->dev = rt->dst.dev;
673
674 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
675
676 if (data_len) {
677 /* RFC 4884 (partial) support :
678 * insert 0 padding at the end, before the extensions
679 */
680 __skb_push(skb2, nhs);
681 skb_reset_network_header(skb2);
682 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
683 memset(skb2->data + data_len - nhs, 0, nhs);
684 /* RFC 4884 4.5 : Length is measured in 64-bit words,
685 * and stored in reserved[0]
686 */
687 info = (data_len/8) << 24;
688 }
689 if (type == ICMP_TIME_EXCEEDED)
690 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
691 info, &temp_saddr);
692 else
693 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
694 info, &temp_saddr);
695 if (rt)
696 ip6_rt_put(rt);
697
698 kfree_skb(skb2);
699
700 return 0;
701}
702EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
703
704static void icmpv6_echo_reply(struct sk_buff *skb)
705{
706 struct net *net = dev_net(skb->dev);
707 struct sock *sk;
708 struct inet6_dev *idev;
709 struct ipv6_pinfo *np;
710 const struct in6_addr *saddr = NULL;
711 struct icmp6hdr *icmph = icmp6_hdr(skb);
712 struct icmp6hdr tmp_hdr;
713 struct flowi6 fl6;
714 struct icmpv6_msg msg;
715 struct dst_entry *dst;
716 struct ipcm6_cookie ipc6;
717 u32 mark = IP6_REPLY_MARK(net, skb->mark);
718 bool acast;
719
720 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
721 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
722 return;
723
724 saddr = &ipv6_hdr(skb)->daddr;
725
726 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
727 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
728 return;
729
730 if (!ipv6_unicast_destination(skb) &&
731 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
732 saddr = NULL;
733
734 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
735 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
736
737 memset(&fl6, 0, sizeof(fl6));
738 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
739 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
740
741 fl6.flowi6_proto = IPPROTO_ICMPV6;
742 fl6.daddr = ipv6_hdr(skb)->saddr;
743 if (saddr)
744 fl6.saddr = *saddr;
745 fl6.flowi6_oif = icmp6_iif(skb);
746 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
747 fl6.flowi6_mark = mark;
748 fl6.flowi6_uid = sock_net_uid(net, NULL);
749 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
750
751 local_bh_disable();
752 sk = icmpv6_xmit_lock(net);
753 if (!sk)
754 goto out_bh_enable;
755 np = inet6_sk(sk);
756
757 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
758 fl6.flowi6_oif = np->mcast_oif;
759 else if (!fl6.flowi6_oif)
760 fl6.flowi6_oif = np->ucast_oif;
761
762 if (ip6_dst_lookup(net, sk, &dst, &fl6))
763 goto out;
764 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
765 if (IS_ERR(dst))
766 goto out;
767
768 /* Check the ratelimit */
769 if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
770 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
771 goto out_dst_release;
772
773 idev = __in6_dev_get(skb->dev);
774
775 msg.skb = skb;
776 msg.offset = 0;
777 msg.type = ICMPV6_ECHO_REPLY;
778
779 ipcm6_init_sk(&ipc6, np);
780 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
781 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
782 ipc6.sockc.mark = mark;
783
784 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
785 skb->len + sizeof(struct icmp6hdr),
786 sizeof(struct icmp6hdr), &ipc6, &fl6,
787 (struct rt6_info *)dst, MSG_DONTWAIT)) {
788 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
789 ip6_flush_pending_frames(sk);
790 } else {
791 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
792 skb->len + sizeof(struct icmp6hdr));
793 }
794out_dst_release:
795 dst_release(dst);
796out:
797 icmpv6_xmit_unlock(sk);
798out_bh_enable:
799 local_bh_enable();
800}
801
802void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
803{
804 const struct inet6_protocol *ipprot;
805 int inner_offset;
806 __be16 frag_off;
807 u8 nexthdr;
808 struct net *net = dev_net(skb->dev);
809
810 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
811 goto out;
812
813 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
814 if (ipv6_ext_hdr(nexthdr)) {
815 /* now skip over extension headers */
816 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
817 &nexthdr, &frag_off);
818 if (inner_offset < 0)
819 goto out;
820 } else {
821 inner_offset = sizeof(struct ipv6hdr);
822 }
823
824 /* Checkin header including 8 bytes of inner protocol header. */
825 if (!pskb_may_pull(skb, inner_offset+8))
826 goto out;
827
828 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
829 Without this we will not able f.e. to make source routed
830 pmtu discovery.
831 Corresponding argument (opt) to notifiers is already added.
832 --ANK (980726)
833 */
834
835 ipprot = rcu_dereference(inet6_protos[nexthdr]);
836 if (ipprot && ipprot->err_handler)
837 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
838
839 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
840 return;
841
842out:
843 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
844}
845
846/*
847 * Handle icmp messages
848 */
849
850static int icmpv6_rcv(struct sk_buff *skb)
851{
852 struct net *net = dev_net(skb->dev);
853 struct net_device *dev = icmp6_dev(skb);
854 struct inet6_dev *idev = __in6_dev_get(dev);
855 const struct in6_addr *saddr, *daddr;
856 struct icmp6hdr *hdr;
857 u8 type;
858 bool success = false;
859
860 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
861 struct sec_path *sp = skb_sec_path(skb);
862 int nh;
863
864 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
865 XFRM_STATE_ICMP))
866 goto drop_no_count;
867
868 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
869 goto drop_no_count;
870
871 nh = skb_network_offset(skb);
872 skb_set_network_header(skb, sizeof(*hdr));
873
874 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
875 goto drop_no_count;
876
877 skb_set_network_header(skb, nh);
878 }
879
880 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
881
882 saddr = &ipv6_hdr(skb)->saddr;
883 daddr = &ipv6_hdr(skb)->daddr;
884
885 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
886 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
887 saddr, daddr);
888 goto csum_error;
889 }
890
891 if (!pskb_pull(skb, sizeof(*hdr)))
892 goto discard_it;
893
894 hdr = icmp6_hdr(skb);
895
896 type = hdr->icmp6_type;
897
898 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
899
900 switch (type) {
901 case ICMPV6_ECHO_REQUEST:
902 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
903 icmpv6_echo_reply(skb);
904 break;
905
906 case ICMPV6_ECHO_REPLY:
907 success = ping_rcv(skb);
908 break;
909
910 case ICMPV6_PKT_TOOBIG:
911 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
912 standard destination cache. Seems, only "advanced"
913 destination cache will allow to solve this problem
914 --ANK (980726)
915 */
916 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
917 goto discard_it;
918 hdr = icmp6_hdr(skb);
919
920 /* to notify */
921 fallthrough;
922 case ICMPV6_DEST_UNREACH:
923 case ICMPV6_TIME_EXCEED:
924 case ICMPV6_PARAMPROB:
925 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
926 break;
927
928 case NDISC_ROUTER_SOLICITATION:
929 case NDISC_ROUTER_ADVERTISEMENT:
930 case NDISC_NEIGHBOUR_SOLICITATION:
931 case NDISC_NEIGHBOUR_ADVERTISEMENT:
932 case NDISC_REDIRECT:
933 ndisc_rcv(skb);
934 break;
935
936 case ICMPV6_MGM_QUERY:
937 igmp6_event_query(skb);
938 break;
939
940 case ICMPV6_MGM_REPORT:
941 igmp6_event_report(skb);
942 break;
943
944 case ICMPV6_MGM_REDUCTION:
945 case ICMPV6_NI_QUERY:
946 case ICMPV6_NI_REPLY:
947 case ICMPV6_MLD2_REPORT:
948 case ICMPV6_DHAAD_REQUEST:
949 case ICMPV6_DHAAD_REPLY:
950 case ICMPV6_MOBILE_PREFIX_SOL:
951 case ICMPV6_MOBILE_PREFIX_ADV:
952 break;
953
954 default:
955 /* informational */
956 if (type & ICMPV6_INFOMSG_MASK)
957 break;
958
959 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
960 saddr, daddr);
961
962 /*
963 * error of unknown type.
964 * must pass to upper level
965 */
966
967 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
968 }
969
970 /* until the v6 path can be better sorted assume failure and
971 * preserve the status quo behaviour for the rest of the paths to here
972 */
973 if (success)
974 consume_skb(skb);
975 else
976 kfree_skb(skb);
977
978 return 0;
979
980csum_error:
981 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
982discard_it:
983 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
984drop_no_count:
985 kfree_skb(skb);
986 return 0;
987}
988
989void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
990 u8 type,
991 const struct in6_addr *saddr,
992 const struct in6_addr *daddr,
993 int oif)
994{
995 memset(fl6, 0, sizeof(*fl6));
996 fl6->saddr = *saddr;
997 fl6->daddr = *daddr;
998 fl6->flowi6_proto = IPPROTO_ICMPV6;
999 fl6->fl6_icmp_type = type;
1000 fl6->fl6_icmp_code = 0;
1001 fl6->flowi6_oif = oif;
1002 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
1003}
1004
1005static void __net_exit icmpv6_sk_exit(struct net *net)
1006{
1007 int i;
1008
1009 for_each_possible_cpu(i)
1010 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv6.icmp_sk, i));
1011 free_percpu(net->ipv6.icmp_sk);
1012}
1013
1014static int __net_init icmpv6_sk_init(struct net *net)
1015{
1016 struct sock *sk;
1017 int err, i;
1018
1019 net->ipv6.icmp_sk = alloc_percpu(struct sock *);
1020 if (!net->ipv6.icmp_sk)
1021 return -ENOMEM;
1022
1023 for_each_possible_cpu(i) {
1024 err = inet_ctl_sock_create(&sk, PF_INET6,
1025 SOCK_RAW, IPPROTO_ICMPV6, net);
1026 if (err < 0) {
1027 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
1028 err);
1029 goto fail;
1030 }
1031
1032 *per_cpu_ptr(net->ipv6.icmp_sk, i) = sk;
1033
1034 /* Enough space for 2 64K ICMP packets, including
1035 * sk_buff struct overhead.
1036 */
1037 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1038 }
1039 return 0;
1040
1041 fail:
1042 icmpv6_sk_exit(net);
1043 return err;
1044}
1045
1046static struct pernet_operations icmpv6_sk_ops = {
1047 .init = icmpv6_sk_init,
1048 .exit = icmpv6_sk_exit,
1049};
1050
1051int __init icmpv6_init(void)
1052{
1053 int err;
1054
1055 err = register_pernet_subsys(&icmpv6_sk_ops);
1056 if (err < 0)
1057 return err;
1058
1059 err = -EAGAIN;
1060 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1061 goto fail;
1062
1063 err = inet6_register_icmp_sender(icmp6_send);
1064 if (err)
1065 goto sender_reg_err;
1066 return 0;
1067
1068sender_reg_err:
1069 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1070fail:
1071 pr_err("Failed to register ICMP6 protocol\n");
1072 unregister_pernet_subsys(&icmpv6_sk_ops);
1073 return err;
1074}
1075
1076void icmpv6_cleanup(void)
1077{
1078 inet6_unregister_icmp_sender(icmp6_send);
1079 unregister_pernet_subsys(&icmpv6_sk_ops);
1080 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1081}
1082
1083
1084static const struct icmp6_err {
1085 int err;
1086 int fatal;
1087} tab_unreach[] = {
1088 { /* NOROUTE */
1089 .err = ENETUNREACH,
1090 .fatal = 0,
1091 },
1092 { /* ADM_PROHIBITED */
1093 .err = EACCES,
1094 .fatal = 1,
1095 },
1096 { /* Was NOT_NEIGHBOUR, now reserved */
1097 .err = EHOSTUNREACH,
1098 .fatal = 0,
1099 },
1100 { /* ADDR_UNREACH */
1101 .err = EHOSTUNREACH,
1102 .fatal = 0,
1103 },
1104 { /* PORT_UNREACH */
1105 .err = ECONNREFUSED,
1106 .fatal = 1,
1107 },
1108 { /* POLICY_FAIL */
1109 .err = EACCES,
1110 .fatal = 1,
1111 },
1112 { /* REJECT_ROUTE */
1113 .err = EACCES,
1114 .fatal = 1,
1115 },
1116};
1117
1118int icmpv6_err_convert(u8 type, u8 code, int *err)
1119{
1120 int fatal = 0;
1121
1122 *err = EPROTO;
1123
1124 switch (type) {
1125 case ICMPV6_DEST_UNREACH:
1126 fatal = 1;
1127 if (code < ARRAY_SIZE(tab_unreach)) {
1128 *err = tab_unreach[code].err;
1129 fatal = tab_unreach[code].fatal;
1130 }
1131 break;
1132
1133 case ICMPV6_PKT_TOOBIG:
1134 *err = EMSGSIZE;
1135 break;
1136
1137 case ICMPV6_PARAMPROB:
1138 *err = EPROTO;
1139 fatal = 1;
1140 break;
1141
1142 case ICMPV6_TIME_EXCEED:
1143 *err = EHOSTUNREACH;
1144 break;
1145 }
1146
1147 return fatal;
1148}
1149EXPORT_SYMBOL(icmpv6_err_convert);
1150
1151#ifdef CONFIG_SYSCTL
1152static struct ctl_table ipv6_icmp_table_template[] = {
1153 {
1154 .procname = "ratelimit",
1155 .data = &init_net.ipv6.sysctl.icmpv6_time,
1156 .maxlen = sizeof(int),
1157 .mode = 0644,
1158 .proc_handler = proc_dointvec_ms_jiffies,
1159 },
1160 {
1161 .procname = "echo_ignore_all",
1162 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1163 .maxlen = sizeof(int),
1164 .mode = 0644,
1165 .proc_handler = proc_dointvec,
1166 },
1167 {
1168 .procname = "echo_ignore_multicast",
1169 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1170 .maxlen = sizeof(int),
1171 .mode = 0644,
1172 .proc_handler = proc_dointvec,
1173 },
1174 {
1175 .procname = "echo_ignore_anycast",
1176 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1177 .maxlen = sizeof(int),
1178 .mode = 0644,
1179 .proc_handler = proc_dointvec,
1180 },
1181 {
1182 .procname = "ratemask",
1183 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1184 .maxlen = ICMPV6_MSG_MAX + 1,
1185 .mode = 0644,
1186 .proc_handler = proc_do_large_bitmap,
1187 },
1188 { },
1189};
1190
1191struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1192{
1193 struct ctl_table *table;
1194
1195 table = kmemdup(ipv6_icmp_table_template,
1196 sizeof(ipv6_icmp_table_template),
1197 GFP_KERNEL);
1198
1199 if (table) {
1200 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1201 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1202 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1203 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1204 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1205 }
1206 return table;
1207}
1208#endif