Loading...
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/seg6.h>
61#include <net/transp_v6.h>
62#include <net/ip6_route.h>
63#include <net/addrconf.h>
64#include <net/icmp.h>
65#include <net/xfrm.h>
66#include <net/inet_common.h>
67#include <net/dsfield.h>
68#include <net/l3mdev.h>
69
70#include <linux/uaccess.h>
71
72static DEFINE_PER_CPU(struct sock *, ipv6_icmp_sk);
73
74static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
75 u8 type, u8 code, int offset, __be32 info)
76{
77 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
78 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
79 struct net *net = dev_net(skb->dev);
80
81 if (type == ICMPV6_PKT_TOOBIG)
82 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
83 else if (type == NDISC_REDIRECT)
84 ip6_redirect(skb, net, skb->dev->ifindex, 0,
85 sock_net_uid(net, NULL));
86
87 if (!(type & ICMPV6_INFOMSG_MASK))
88 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
89 ping_err(skb, offset, ntohl(info));
90
91 return 0;
92}
93
94static int icmpv6_rcv(struct sk_buff *skb);
95
96static const struct inet6_protocol icmpv6_protocol = {
97 .handler = icmpv6_rcv,
98 .err_handler = icmpv6_err,
99 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
100};
101
102/* Called with BH disabled */
103static struct sock *icmpv6_xmit_lock(struct net *net)
104{
105 struct sock *sk;
106
107 sk = this_cpu_read(ipv6_icmp_sk);
108 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
109 /* This can happen if the output path (f.e. SIT or
110 * ip6ip6 tunnel) signals dst_link_failure() for an
111 * outgoing ICMP6 packet.
112 */
113 return NULL;
114 }
115 sock_net_set(sk, net);
116 return sk;
117}
118
119static void icmpv6_xmit_unlock(struct sock *sk)
120{
121 sock_net_set(sk, &init_net);
122 spin_unlock(&sk->sk_lock.slock);
123}
124
125/*
126 * Figure out, may we reply to this packet with icmp error.
127 *
128 * We do not reply, if:
129 * - it was icmp error message.
130 * - it is truncated, so that it is known, that protocol is ICMPV6
131 * (i.e. in the middle of some exthdr)
132 *
133 * --ANK (980726)
134 */
135
136static bool is_ineligible(const struct sk_buff *skb)
137{
138 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
139 int len = skb->len - ptr;
140 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
141 __be16 frag_off;
142
143 if (len < 0)
144 return true;
145
146 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
147 if (ptr < 0)
148 return false;
149 if (nexthdr == IPPROTO_ICMPV6) {
150 u8 _type, *tp;
151 tp = skb_header_pointer(skb,
152 ptr+offsetof(struct icmp6hdr, icmp6_type),
153 sizeof(_type), &_type);
154
155 /* Based on RFC 8200, Section 4.5 Fragment Header, return
156 * false if this is a fragment packet with no icmp header info.
157 */
158 if (!tp && frag_off != 0)
159 return false;
160 else if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
161 return true;
162 }
163 return false;
164}
165
166static bool icmpv6_mask_allow(struct net *net, int type)
167{
168 if (type > ICMPV6_MSG_MAX)
169 return true;
170
171 /* Limit if icmp type is set in ratemask. */
172 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
173 return true;
174
175 return false;
176}
177
178static bool icmpv6_global_allow(struct net *net, int type)
179{
180 if (icmpv6_mask_allow(net, type))
181 return true;
182
183 if (icmp_global_allow())
184 return true;
185
186 return false;
187}
188
189/*
190 * Check the ICMP output rate limit
191 */
192static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
193 struct flowi6 *fl6)
194{
195 struct net *net = sock_net(sk);
196 struct dst_entry *dst;
197 bool res = false;
198
199 if (icmpv6_mask_allow(net, type))
200 return true;
201
202 /*
203 * Look up the output route.
204 * XXX: perhaps the expire for routing entries cloned by
205 * this lookup should be more aggressive (not longer than timeout).
206 */
207 dst = ip6_route_output(net, sk, fl6);
208 if (dst->error) {
209 IP6_INC_STATS(net, ip6_dst_idev(dst),
210 IPSTATS_MIB_OUTNOROUTES);
211 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
212 res = true;
213 } else {
214 struct rt6_info *rt = (struct rt6_info *)dst;
215 int tmo = net->ipv6.sysctl.icmpv6_time;
216 struct inet_peer *peer;
217
218 /* Give more bandwidth to wider prefixes. */
219 if (rt->rt6i_dst.plen < 128)
220 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
221
222 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
223 res = inet_peer_xrlim_allow(peer, tmo);
224 if (peer)
225 inet_putpeer(peer);
226 }
227 dst_release(dst);
228 return res;
229}
230
231static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type,
232 struct flowi6 *fl6)
233{
234 struct net *net = sock_net(sk);
235 struct dst_entry *dst;
236 bool res = false;
237
238 dst = ip6_route_output(net, sk, fl6);
239 if (!dst->error) {
240 struct rt6_info *rt = (struct rt6_info *)dst;
241 struct in6_addr prefsrc;
242
243 rt6_get_prefsrc(rt, &prefsrc);
244 res = !ipv6_addr_any(&prefsrc);
245 }
246 dst_release(dst);
247 return res;
248}
249
250/*
251 * an inline helper for the "simple" if statement below
252 * checks if parameter problem report is caused by an
253 * unrecognized IPv6 option that has the Option Type
254 * highest-order two bits set to 10
255 */
256
257static bool opt_unrec(struct sk_buff *skb, __u32 offset)
258{
259 u8 _optval, *op;
260
261 offset += skb_network_offset(skb);
262 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
263 if (!op)
264 return true;
265 return (*op & 0xC0) == 0x80;
266}
267
268void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
269 struct icmp6hdr *thdr, int len)
270{
271 struct sk_buff *skb;
272 struct icmp6hdr *icmp6h;
273
274 skb = skb_peek(&sk->sk_write_queue);
275 if (!skb)
276 return;
277
278 icmp6h = icmp6_hdr(skb);
279 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
280 icmp6h->icmp6_cksum = 0;
281
282 if (skb_queue_len(&sk->sk_write_queue) == 1) {
283 skb->csum = csum_partial(icmp6h,
284 sizeof(struct icmp6hdr), skb->csum);
285 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
286 &fl6->daddr,
287 len, fl6->flowi6_proto,
288 skb->csum);
289 } else {
290 __wsum tmp_csum = 0;
291
292 skb_queue_walk(&sk->sk_write_queue, skb) {
293 tmp_csum = csum_add(tmp_csum, skb->csum);
294 }
295
296 tmp_csum = csum_partial(icmp6h,
297 sizeof(struct icmp6hdr), tmp_csum);
298 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
299 &fl6->daddr,
300 len, fl6->flowi6_proto,
301 tmp_csum);
302 }
303 ip6_push_pending_frames(sk);
304}
305
306struct icmpv6_msg {
307 struct sk_buff *skb;
308 int offset;
309 uint8_t type;
310};
311
312static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
313{
314 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
315 struct sk_buff *org_skb = msg->skb;
316 __wsum csum;
317
318 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
319 to, len);
320 skb->csum = csum_block_add(skb->csum, csum, odd);
321 if (!(msg->type & ICMPV6_INFOMSG_MASK))
322 nf_ct_attach(skb, org_skb);
323 return 0;
324}
325
326#if IS_ENABLED(CONFIG_IPV6_MIP6)
327static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt)
328{
329 struct ipv6hdr *iph = ipv6_hdr(skb);
330 struct ipv6_destopt_hao *hao;
331 struct in6_addr tmp;
332 int off;
333
334 if (opt->dsthao) {
335 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
336 if (likely(off >= 0)) {
337 hao = (struct ipv6_destopt_hao *)
338 (skb_network_header(skb) + off);
339 tmp = iph->saddr;
340 iph->saddr = hao->addr;
341 hao->addr = tmp;
342 }
343 }
344}
345#else
346static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {}
347#endif
348
349static struct dst_entry *icmpv6_route_lookup(struct net *net,
350 struct sk_buff *skb,
351 struct sock *sk,
352 struct flowi6 *fl6)
353{
354 struct dst_entry *dst, *dst2;
355 struct flowi6 fl2;
356 int err;
357
358 err = ip6_dst_lookup(net, sk, &dst, fl6);
359 if (err)
360 return ERR_PTR(err);
361
362 /*
363 * We won't send icmp if the destination is known
364 * anycast.
365 */
366 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
367 net_dbg_ratelimited("icmp6_send: acast source\n");
368 dst_release(dst);
369 return ERR_PTR(-EINVAL);
370 }
371
372 /* No need to clone since we're just using its address. */
373 dst2 = dst;
374
375 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
376 if (!IS_ERR(dst)) {
377 if (dst != dst2)
378 return dst;
379 } else {
380 if (PTR_ERR(dst) == -EPERM)
381 dst = NULL;
382 else
383 return dst;
384 }
385
386 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
387 if (err)
388 goto relookup_failed;
389
390 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
391 if (err)
392 goto relookup_failed;
393
394 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
395 if (!IS_ERR(dst2)) {
396 dst_release(dst);
397 dst = dst2;
398 } else {
399 err = PTR_ERR(dst2);
400 if (err == -EPERM) {
401 dst_release(dst);
402 return dst2;
403 } else
404 goto relookup_failed;
405 }
406
407relookup_failed:
408 if (dst)
409 return dst;
410 return ERR_PTR(err);
411}
412
413static struct net_device *icmp6_dev(const struct sk_buff *skb)
414{
415 struct net_device *dev = skb->dev;
416
417 /* for local traffic to local address, skb dev is the loopback
418 * device. Check if there is a dst attached to the skb and if so
419 * get the real device index. Same is needed for replies to a link
420 * local address on a device enslaved to an L3 master device
421 */
422 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
423 const struct rt6_info *rt6 = skb_rt6_info(skb);
424
425 if (rt6)
426 dev = rt6->rt6i_idev->dev;
427 }
428
429 return dev;
430}
431
432static int icmp6_iif(const struct sk_buff *skb)
433{
434 return icmp6_dev(skb)->ifindex;
435}
436
437/*
438 * Send an ICMP message in response to a packet in error
439 */
440void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
441 const struct in6_addr *force_saddr,
442 const struct inet6_skb_parm *parm)
443{
444 struct inet6_dev *idev = NULL;
445 struct ipv6hdr *hdr = ipv6_hdr(skb);
446 struct sock *sk;
447 struct net *net;
448 struct ipv6_pinfo *np;
449 const struct in6_addr *saddr = NULL;
450 struct dst_entry *dst;
451 struct icmp6hdr tmp_hdr;
452 struct flowi6 fl6;
453 struct icmpv6_msg msg;
454 struct ipcm6_cookie ipc6;
455 int iif = 0;
456 int addr_type = 0;
457 int len;
458 u32 mark;
459
460 if ((u8 *)hdr < skb->head ||
461 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
462 return;
463
464 if (!skb->dev)
465 return;
466 net = dev_net(skb->dev);
467 mark = IP6_REPLY_MARK(net, skb->mark);
468 /*
469 * Make sure we respect the rules
470 * i.e. RFC 1885 2.4(e)
471 * Rule (e.1) is enforced by not using icmp6_send
472 * in any code that processes icmp errors.
473 */
474 addr_type = ipv6_addr_type(&hdr->daddr);
475
476 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
477 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
478 saddr = &hdr->daddr;
479
480 /*
481 * Dest addr check
482 */
483
484 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
485 if (type != ICMPV6_PKT_TOOBIG &&
486 !(type == ICMPV6_PARAMPROB &&
487 code == ICMPV6_UNK_OPTION &&
488 (opt_unrec(skb, info))))
489 return;
490
491 saddr = NULL;
492 }
493
494 addr_type = ipv6_addr_type(&hdr->saddr);
495
496 /*
497 * Source addr check
498 */
499
500 if (__ipv6_addr_needs_scope_id(addr_type)) {
501 iif = icmp6_iif(skb);
502 } else {
503 /*
504 * The source device is used for looking up which routing table
505 * to use for sending an ICMP error.
506 */
507 iif = l3mdev_master_ifindex(skb->dev);
508 }
509
510 /*
511 * Must not send error if the source does not uniquely
512 * identify a single node (RFC2463 Section 2.4).
513 * We check unspecified / multicast addresses here,
514 * and anycast addresses will be checked later.
515 */
516 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
517 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
518 &hdr->saddr, &hdr->daddr);
519 return;
520 }
521
522 /*
523 * Never answer to a ICMP packet.
524 */
525 if (is_ineligible(skb)) {
526 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
527 &hdr->saddr, &hdr->daddr);
528 return;
529 }
530
531 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
532 local_bh_disable();
533
534 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
535 if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
536 goto out_bh_enable;
537
538 mip6_addr_swap(skb, parm);
539
540 sk = icmpv6_xmit_lock(net);
541 if (!sk)
542 goto out_bh_enable;
543
544 memset(&fl6, 0, sizeof(fl6));
545 fl6.flowi6_proto = IPPROTO_ICMPV6;
546 fl6.daddr = hdr->saddr;
547 if (force_saddr)
548 saddr = force_saddr;
549 if (saddr) {
550 fl6.saddr = *saddr;
551 } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) {
552 /* select a more meaningful saddr from input if */
553 struct net_device *in_netdev;
554
555 in_netdev = dev_get_by_index(net, parm->iif);
556 if (in_netdev) {
557 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
558 inet6_sk(sk)->srcprefs,
559 &fl6.saddr);
560 dev_put(in_netdev);
561 }
562 }
563 fl6.flowi6_mark = mark;
564 fl6.flowi6_oif = iif;
565 fl6.fl6_icmp_type = type;
566 fl6.fl6_icmp_code = code;
567 fl6.flowi6_uid = sock_net_uid(net, NULL);
568 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
569 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
570
571 np = inet6_sk(sk);
572
573 if (!icmpv6_xrlim_allow(sk, type, &fl6))
574 goto out;
575
576 tmp_hdr.icmp6_type = type;
577 tmp_hdr.icmp6_code = code;
578 tmp_hdr.icmp6_cksum = 0;
579 tmp_hdr.icmp6_pointer = htonl(info);
580
581 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
582 fl6.flowi6_oif = np->mcast_oif;
583 else if (!fl6.flowi6_oif)
584 fl6.flowi6_oif = np->ucast_oif;
585
586 ipcm6_init_sk(&ipc6, np);
587 ipc6.sockc.mark = mark;
588 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
589
590 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
591 if (IS_ERR(dst))
592 goto out;
593
594 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
595
596 msg.skb = skb;
597 msg.offset = skb_network_offset(skb);
598 msg.type = type;
599
600 len = skb->len - msg.offset;
601 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
602 if (len < 0) {
603 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
604 &hdr->saddr, &hdr->daddr);
605 goto out_dst_release;
606 }
607
608 rcu_read_lock();
609 idev = __in6_dev_get(skb->dev);
610
611 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
612 len + sizeof(struct icmp6hdr),
613 sizeof(struct icmp6hdr),
614 &ipc6, &fl6, (struct rt6_info *)dst,
615 MSG_DONTWAIT)) {
616 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
617 ip6_flush_pending_frames(sk);
618 } else {
619 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
620 len + sizeof(struct icmp6hdr));
621 }
622 rcu_read_unlock();
623out_dst_release:
624 dst_release(dst);
625out:
626 icmpv6_xmit_unlock(sk);
627out_bh_enable:
628 local_bh_enable();
629}
630EXPORT_SYMBOL(icmp6_send);
631
632/* Slightly more convenient version of icmp6_send with drop reasons.
633 */
634void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos,
635 enum skb_drop_reason reason)
636{
637 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
638 kfree_skb_reason(skb, reason);
639}
640
641/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
642 * if sufficient data bytes are available
643 * @nhs is the size of the tunnel header(s) :
644 * Either an IPv4 header for SIT encap
645 * an IPv4 header + GRE header for GRE encap
646 */
647int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
648 unsigned int data_len)
649{
650 struct in6_addr temp_saddr;
651 struct rt6_info *rt;
652 struct sk_buff *skb2;
653 u32 info = 0;
654
655 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
656 return 1;
657
658 /* RFC 4884 (partial) support for ICMP extensions */
659 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
660 data_len = 0;
661
662 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
663
664 if (!skb2)
665 return 1;
666
667 skb_dst_drop(skb2);
668 skb_pull(skb2, nhs);
669 skb_reset_network_header(skb2);
670
671 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
672 skb, 0);
673
674 if (rt && rt->dst.dev)
675 skb2->dev = rt->dst.dev;
676
677 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
678
679 if (data_len) {
680 /* RFC 4884 (partial) support :
681 * insert 0 padding at the end, before the extensions
682 */
683 __skb_push(skb2, nhs);
684 skb_reset_network_header(skb2);
685 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
686 memset(skb2->data + data_len - nhs, 0, nhs);
687 /* RFC 4884 4.5 : Length is measured in 64-bit words,
688 * and stored in reserved[0]
689 */
690 info = (data_len/8) << 24;
691 }
692 if (type == ICMP_TIME_EXCEEDED)
693 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
694 info, &temp_saddr, IP6CB(skb2));
695 else
696 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
697 info, &temp_saddr, IP6CB(skb2));
698 if (rt)
699 ip6_rt_put(rt);
700
701 kfree_skb(skb2);
702
703 return 0;
704}
705EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
706
707static void icmpv6_echo_reply(struct sk_buff *skb)
708{
709 struct net *net = dev_net(skb->dev);
710 struct sock *sk;
711 struct inet6_dev *idev;
712 struct ipv6_pinfo *np;
713 const struct in6_addr *saddr = NULL;
714 struct icmp6hdr *icmph = icmp6_hdr(skb);
715 struct icmp6hdr tmp_hdr;
716 struct flowi6 fl6;
717 struct icmpv6_msg msg;
718 struct dst_entry *dst;
719 struct ipcm6_cookie ipc6;
720 u32 mark = IP6_REPLY_MARK(net, skb->mark);
721 bool acast;
722 u8 type;
723
724 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
725 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
726 return;
727
728 saddr = &ipv6_hdr(skb)->daddr;
729
730 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
731 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
732 return;
733
734 if (!ipv6_unicast_destination(skb) &&
735 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
736 saddr = NULL;
737
738 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
739 type = ICMPV6_EXT_ECHO_REPLY;
740 else
741 type = ICMPV6_ECHO_REPLY;
742
743 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
744 tmp_hdr.icmp6_type = type;
745
746 memset(&fl6, 0, sizeof(fl6));
747 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
748 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
749
750 fl6.flowi6_proto = IPPROTO_ICMPV6;
751 fl6.daddr = ipv6_hdr(skb)->saddr;
752 if (saddr)
753 fl6.saddr = *saddr;
754 fl6.flowi6_oif = icmp6_iif(skb);
755 fl6.fl6_icmp_type = type;
756 fl6.flowi6_mark = mark;
757 fl6.flowi6_uid = sock_net_uid(net, NULL);
758 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
759
760 local_bh_disable();
761 sk = icmpv6_xmit_lock(net);
762 if (!sk)
763 goto out_bh_enable;
764 np = inet6_sk(sk);
765
766 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
767 fl6.flowi6_oif = np->mcast_oif;
768 else if (!fl6.flowi6_oif)
769 fl6.flowi6_oif = np->ucast_oif;
770
771 if (ip6_dst_lookup(net, sk, &dst, &fl6))
772 goto out;
773 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
774 if (IS_ERR(dst))
775 goto out;
776
777 /* Check the ratelimit */
778 if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
779 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
780 goto out_dst_release;
781
782 idev = __in6_dev_get(skb->dev);
783
784 msg.skb = skb;
785 msg.offset = 0;
786 msg.type = type;
787
788 ipcm6_init_sk(&ipc6, np);
789 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
790 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
791 ipc6.sockc.mark = mark;
792
793 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
794 if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr))
795 goto out_dst_release;
796
797 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
798 skb->len + sizeof(struct icmp6hdr),
799 sizeof(struct icmp6hdr), &ipc6, &fl6,
800 (struct rt6_info *)dst, MSG_DONTWAIT)) {
801 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
802 ip6_flush_pending_frames(sk);
803 } else {
804 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
805 skb->len + sizeof(struct icmp6hdr));
806 }
807out_dst_release:
808 dst_release(dst);
809out:
810 icmpv6_xmit_unlock(sk);
811out_bh_enable:
812 local_bh_enable();
813}
814
815void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
816{
817 struct inet6_skb_parm *opt = IP6CB(skb);
818 const struct inet6_protocol *ipprot;
819 int inner_offset;
820 __be16 frag_off;
821 u8 nexthdr;
822 struct net *net = dev_net(skb->dev);
823
824 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
825 goto out;
826
827 seg6_icmp_srh(skb, opt);
828
829 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
830 if (ipv6_ext_hdr(nexthdr)) {
831 /* now skip over extension headers */
832 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
833 &nexthdr, &frag_off);
834 if (inner_offset < 0)
835 goto out;
836 } else {
837 inner_offset = sizeof(struct ipv6hdr);
838 }
839
840 /* Checkin header including 8 bytes of inner protocol header. */
841 if (!pskb_may_pull(skb, inner_offset+8))
842 goto out;
843
844 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
845 Without this we will not able f.e. to make source routed
846 pmtu discovery.
847 Corresponding argument (opt) to notifiers is already added.
848 --ANK (980726)
849 */
850
851 ipprot = rcu_dereference(inet6_protos[nexthdr]);
852 if (ipprot && ipprot->err_handler)
853 ipprot->err_handler(skb, opt, type, code, inner_offset, info);
854
855 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
856 return;
857
858out:
859 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
860}
861
862/*
863 * Handle icmp messages
864 */
865
866static int icmpv6_rcv(struct sk_buff *skb)
867{
868 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
869 struct net *net = dev_net(skb->dev);
870 struct net_device *dev = icmp6_dev(skb);
871 struct inet6_dev *idev = __in6_dev_get(dev);
872 const struct in6_addr *saddr, *daddr;
873 struct icmp6hdr *hdr;
874 u8 type;
875
876 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
877 struct sec_path *sp = skb_sec_path(skb);
878 int nh;
879
880 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
881 XFRM_STATE_ICMP)) {
882 reason = SKB_DROP_REASON_XFRM_POLICY;
883 goto drop_no_count;
884 }
885
886 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
887 goto drop_no_count;
888
889 nh = skb_network_offset(skb);
890 skb_set_network_header(skb, sizeof(*hdr));
891
892 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN,
893 skb)) {
894 reason = SKB_DROP_REASON_XFRM_POLICY;
895 goto drop_no_count;
896 }
897
898 skb_set_network_header(skb, nh);
899 }
900
901 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
902
903 saddr = &ipv6_hdr(skb)->saddr;
904 daddr = &ipv6_hdr(skb)->daddr;
905
906 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
907 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
908 saddr, daddr);
909 goto csum_error;
910 }
911
912 if (!pskb_pull(skb, sizeof(*hdr)))
913 goto discard_it;
914
915 hdr = icmp6_hdr(skb);
916
917 type = hdr->icmp6_type;
918
919 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
920
921 switch (type) {
922 case ICMPV6_ECHO_REQUEST:
923 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
924 icmpv6_echo_reply(skb);
925 break;
926 case ICMPV6_EXT_ECHO_REQUEST:
927 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all &&
928 READ_ONCE(net->ipv4.sysctl_icmp_echo_enable_probe))
929 icmpv6_echo_reply(skb);
930 break;
931
932 case ICMPV6_ECHO_REPLY:
933 reason = ping_rcv(skb);
934 break;
935
936 case ICMPV6_EXT_ECHO_REPLY:
937 reason = ping_rcv(skb);
938 break;
939
940 case ICMPV6_PKT_TOOBIG:
941 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
942 standard destination cache. Seems, only "advanced"
943 destination cache will allow to solve this problem
944 --ANK (980726)
945 */
946 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
947 goto discard_it;
948 hdr = icmp6_hdr(skb);
949
950 /* to notify */
951 fallthrough;
952 case ICMPV6_DEST_UNREACH:
953 case ICMPV6_TIME_EXCEED:
954 case ICMPV6_PARAMPROB:
955 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
956 break;
957
958 case NDISC_ROUTER_SOLICITATION:
959 case NDISC_ROUTER_ADVERTISEMENT:
960 case NDISC_NEIGHBOUR_SOLICITATION:
961 case NDISC_NEIGHBOUR_ADVERTISEMENT:
962 case NDISC_REDIRECT:
963 ndisc_rcv(skb);
964 break;
965
966 case ICMPV6_MGM_QUERY:
967 igmp6_event_query(skb);
968 return 0;
969
970 case ICMPV6_MGM_REPORT:
971 igmp6_event_report(skb);
972 return 0;
973
974 case ICMPV6_MGM_REDUCTION:
975 case ICMPV6_NI_QUERY:
976 case ICMPV6_NI_REPLY:
977 case ICMPV6_MLD2_REPORT:
978 case ICMPV6_DHAAD_REQUEST:
979 case ICMPV6_DHAAD_REPLY:
980 case ICMPV6_MOBILE_PREFIX_SOL:
981 case ICMPV6_MOBILE_PREFIX_ADV:
982 break;
983
984 default:
985 /* informational */
986 if (type & ICMPV6_INFOMSG_MASK)
987 break;
988
989 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
990 saddr, daddr);
991
992 /*
993 * error of unknown type.
994 * must pass to upper level
995 */
996
997 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
998 }
999
1000 /* until the v6 path can be better sorted assume failure and
1001 * preserve the status quo behaviour for the rest of the paths to here
1002 */
1003 if (reason)
1004 kfree_skb_reason(skb, reason);
1005 else
1006 consume_skb(skb);
1007
1008 return 0;
1009
1010csum_error:
1011 reason = SKB_DROP_REASON_ICMP_CSUM;
1012 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
1013discard_it:
1014 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
1015drop_no_count:
1016 kfree_skb_reason(skb, reason);
1017 return 0;
1018}
1019
1020void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
1021 u8 type,
1022 const struct in6_addr *saddr,
1023 const struct in6_addr *daddr,
1024 int oif)
1025{
1026 memset(fl6, 0, sizeof(*fl6));
1027 fl6->saddr = *saddr;
1028 fl6->daddr = *daddr;
1029 fl6->flowi6_proto = IPPROTO_ICMPV6;
1030 fl6->fl6_icmp_type = type;
1031 fl6->fl6_icmp_code = 0;
1032 fl6->flowi6_oif = oif;
1033 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1034}
1035
1036int __init icmpv6_init(void)
1037{
1038 struct sock *sk;
1039 int err, i;
1040
1041 for_each_possible_cpu(i) {
1042 err = inet_ctl_sock_create(&sk, PF_INET6,
1043 SOCK_RAW, IPPROTO_ICMPV6, &init_net);
1044 if (err < 0) {
1045 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
1046 err);
1047 return err;
1048 }
1049
1050 per_cpu(ipv6_icmp_sk, i) = sk;
1051
1052 /* Enough space for 2 64K ICMP packets, including
1053 * sk_buff struct overhead.
1054 */
1055 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1056 }
1057
1058 err = -EAGAIN;
1059 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1060 goto fail;
1061
1062 err = inet6_register_icmp_sender(icmp6_send);
1063 if (err)
1064 goto sender_reg_err;
1065 return 0;
1066
1067sender_reg_err:
1068 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1069fail:
1070 pr_err("Failed to register ICMP6 protocol\n");
1071 return err;
1072}
1073
1074void icmpv6_cleanup(void)
1075{
1076 inet6_unregister_icmp_sender(icmp6_send);
1077 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1078}
1079
1080
1081static const struct icmp6_err {
1082 int err;
1083 int fatal;
1084} tab_unreach[] = {
1085 { /* NOROUTE */
1086 .err = ENETUNREACH,
1087 .fatal = 0,
1088 },
1089 { /* ADM_PROHIBITED */
1090 .err = EACCES,
1091 .fatal = 1,
1092 },
1093 { /* Was NOT_NEIGHBOUR, now reserved */
1094 .err = EHOSTUNREACH,
1095 .fatal = 0,
1096 },
1097 { /* ADDR_UNREACH */
1098 .err = EHOSTUNREACH,
1099 .fatal = 0,
1100 },
1101 { /* PORT_UNREACH */
1102 .err = ECONNREFUSED,
1103 .fatal = 1,
1104 },
1105 { /* POLICY_FAIL */
1106 .err = EACCES,
1107 .fatal = 1,
1108 },
1109 { /* REJECT_ROUTE */
1110 .err = EACCES,
1111 .fatal = 1,
1112 },
1113};
1114
1115int icmpv6_err_convert(u8 type, u8 code, int *err)
1116{
1117 int fatal = 0;
1118
1119 *err = EPROTO;
1120
1121 switch (type) {
1122 case ICMPV6_DEST_UNREACH:
1123 fatal = 1;
1124 if (code < ARRAY_SIZE(tab_unreach)) {
1125 *err = tab_unreach[code].err;
1126 fatal = tab_unreach[code].fatal;
1127 }
1128 break;
1129
1130 case ICMPV6_PKT_TOOBIG:
1131 *err = EMSGSIZE;
1132 break;
1133
1134 case ICMPV6_PARAMPROB:
1135 *err = EPROTO;
1136 fatal = 1;
1137 break;
1138
1139 case ICMPV6_TIME_EXCEED:
1140 *err = EHOSTUNREACH;
1141 break;
1142 }
1143
1144 return fatal;
1145}
1146EXPORT_SYMBOL(icmpv6_err_convert);
1147
1148#ifdef CONFIG_SYSCTL
1149static struct ctl_table ipv6_icmp_table_template[] = {
1150 {
1151 .procname = "ratelimit",
1152 .data = &init_net.ipv6.sysctl.icmpv6_time,
1153 .maxlen = sizeof(int),
1154 .mode = 0644,
1155 .proc_handler = proc_dointvec_ms_jiffies,
1156 },
1157 {
1158 .procname = "echo_ignore_all",
1159 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1160 .maxlen = sizeof(u8),
1161 .mode = 0644,
1162 .proc_handler = proc_dou8vec_minmax,
1163 },
1164 {
1165 .procname = "echo_ignore_multicast",
1166 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1167 .maxlen = sizeof(u8),
1168 .mode = 0644,
1169 .proc_handler = proc_dou8vec_minmax,
1170 },
1171 {
1172 .procname = "echo_ignore_anycast",
1173 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1174 .maxlen = sizeof(u8),
1175 .mode = 0644,
1176 .proc_handler = proc_dou8vec_minmax,
1177 },
1178 {
1179 .procname = "ratemask",
1180 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1181 .maxlen = ICMPV6_MSG_MAX + 1,
1182 .mode = 0644,
1183 .proc_handler = proc_do_large_bitmap,
1184 },
1185 { },
1186};
1187
1188struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1189{
1190 struct ctl_table *table;
1191
1192 table = kmemdup(ipv6_icmp_table_template,
1193 sizeof(ipv6_icmp_table_template),
1194 GFP_KERNEL);
1195
1196 if (table) {
1197 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1198 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1199 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1200 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1201 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1202 }
1203 return table;
1204}
1205#endif