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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Internet Control Message Protocol (ICMPv6)
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on net/ipv4/icmp.c
10 *
11 * RFC 1885
12 */
13
14/*
15 * Changes:
16 *
17 * Andi Kleen : exception handling
18 * Andi Kleen add rate limits. never reply to a icmp.
19 * add more length checks and other fixes.
20 * yoshfuji : ensure to sent parameter problem for
21 * fragments.
22 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
23 * Randy Dunlap and
24 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
25 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
26 */
27
28#define pr_fmt(fmt) "IPv6: " fmt
29
30#include <linux/module.h>
31#include <linux/errno.h>
32#include <linux/types.h>
33#include <linux/socket.h>
34#include <linux/in.h>
35#include <linux/kernel.h>
36#include <linux/sockios.h>
37#include <linux/net.h>
38#include <linux/skbuff.h>
39#include <linux/init.h>
40#include <linux/netfilter.h>
41#include <linux/slab.h>
42
43#ifdef CONFIG_SYSCTL
44#include <linux/sysctl.h>
45#endif
46
47#include <linux/inet.h>
48#include <linux/netdevice.h>
49#include <linux/icmpv6.h>
50
51#include <net/ip.h>
52#include <net/sock.h>
53
54#include <net/ipv6.h>
55#include <net/ip6_checksum.h>
56#include <net/ping.h>
57#include <net/protocol.h>
58#include <net/raw.h>
59#include <net/rawv6.h>
60#include <net/seg6.h>
61#include <net/transp_v6.h>
62#include <net/ip6_route.h>
63#include <net/addrconf.h>
64#include <net/icmp.h>
65#include <net/xfrm.h>
66#include <net/inet_common.h>
67#include <net/dsfield.h>
68#include <net/l3mdev.h>
69
70#include <linux/uaccess.h>
71
72static DEFINE_PER_CPU(struct sock *, ipv6_icmp_sk);
73
74static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
75 u8 type, u8 code, int offset, __be32 info)
76{
77 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
78 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
79 struct net *net = dev_net(skb->dev);
80
81 if (type == ICMPV6_PKT_TOOBIG)
82 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
83 else if (type == NDISC_REDIRECT)
84 ip6_redirect(skb, net, skb->dev->ifindex, 0,
85 sock_net_uid(net, NULL));
86
87 if (!(type & ICMPV6_INFOMSG_MASK))
88 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
89 ping_err(skb, offset, ntohl(info));
90
91 return 0;
92}
93
94static int icmpv6_rcv(struct sk_buff *skb);
95
96static const struct inet6_protocol icmpv6_protocol = {
97 .handler = icmpv6_rcv,
98 .err_handler = icmpv6_err,
99 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
100};
101
102/* Called with BH disabled */
103static struct sock *icmpv6_xmit_lock(struct net *net)
104{
105 struct sock *sk;
106
107 sk = this_cpu_read(ipv6_icmp_sk);
108 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
109 /* This can happen if the output path (f.e. SIT or
110 * ip6ip6 tunnel) signals dst_link_failure() for an
111 * outgoing ICMP6 packet.
112 */
113 return NULL;
114 }
115 sock_net_set(sk, net);
116 return sk;
117}
118
119static void icmpv6_xmit_unlock(struct sock *sk)
120{
121 sock_net_set(sk, &init_net);
122 spin_unlock(&sk->sk_lock.slock);
123}
124
125/*
126 * Figure out, may we reply to this packet with icmp error.
127 *
128 * We do not reply, if:
129 * - it was icmp error message.
130 * - it is truncated, so that it is known, that protocol is ICMPV6
131 * (i.e. in the middle of some exthdr)
132 *
133 * --ANK (980726)
134 */
135
136static bool is_ineligible(const struct sk_buff *skb)
137{
138 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
139 int len = skb->len - ptr;
140 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
141 __be16 frag_off;
142
143 if (len < 0)
144 return true;
145
146 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
147 if (ptr < 0)
148 return false;
149 if (nexthdr == IPPROTO_ICMPV6) {
150 u8 _type, *tp;
151 tp = skb_header_pointer(skb,
152 ptr+offsetof(struct icmp6hdr, icmp6_type),
153 sizeof(_type), &_type);
154
155 /* Based on RFC 8200, Section 4.5 Fragment Header, return
156 * false if this is a fragment packet with no icmp header info.
157 */
158 if (!tp && frag_off != 0)
159 return false;
160 else if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
161 return true;
162 }
163 return false;
164}
165
166static bool icmpv6_mask_allow(struct net *net, int type)
167{
168 if (type > ICMPV6_MSG_MAX)
169 return true;
170
171 /* Limit if icmp type is set in ratemask. */
172 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
173 return true;
174
175 return false;
176}
177
178static bool icmpv6_global_allow(struct net *net, int type)
179{
180 if (icmpv6_mask_allow(net, type))
181 return true;
182
183 if (icmp_global_allow())
184 return true;
185
186 __ICMP_INC_STATS(net, ICMP_MIB_RATELIMITGLOBAL);
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 if (!res)
229 __ICMP6_INC_STATS(net, ip6_dst_idev(dst),
230 ICMP6_MIB_RATELIMITHOST);
231 dst_release(dst);
232 return res;
233}
234
235static bool icmpv6_rt_has_prefsrc(struct sock *sk, u8 type,
236 struct flowi6 *fl6)
237{
238 struct net *net = sock_net(sk);
239 struct dst_entry *dst;
240 bool res = false;
241
242 dst = ip6_route_output(net, sk, fl6);
243 if (!dst->error) {
244 struct rt6_info *rt = (struct rt6_info *)dst;
245 struct in6_addr prefsrc;
246
247 rt6_get_prefsrc(rt, &prefsrc);
248 res = !ipv6_addr_any(&prefsrc);
249 }
250 dst_release(dst);
251 return res;
252}
253
254/*
255 * an inline helper for the "simple" if statement below
256 * checks if parameter problem report is caused by an
257 * unrecognized IPv6 option that has the Option Type
258 * highest-order two bits set to 10
259 */
260
261static bool opt_unrec(struct sk_buff *skb, __u32 offset)
262{
263 u8 _optval, *op;
264
265 offset += skb_network_offset(skb);
266 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
267 if (!op)
268 return true;
269 return (*op & 0xC0) == 0x80;
270}
271
272void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
273 struct icmp6hdr *thdr, int len)
274{
275 struct sk_buff *skb;
276 struct icmp6hdr *icmp6h;
277
278 skb = skb_peek(&sk->sk_write_queue);
279 if (!skb)
280 return;
281
282 icmp6h = icmp6_hdr(skb);
283 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
284 icmp6h->icmp6_cksum = 0;
285
286 if (skb_queue_len(&sk->sk_write_queue) == 1) {
287 skb->csum = csum_partial(icmp6h,
288 sizeof(struct icmp6hdr), skb->csum);
289 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
290 &fl6->daddr,
291 len, fl6->flowi6_proto,
292 skb->csum);
293 } else {
294 __wsum tmp_csum = 0;
295
296 skb_queue_walk(&sk->sk_write_queue, skb) {
297 tmp_csum = csum_add(tmp_csum, skb->csum);
298 }
299
300 tmp_csum = csum_partial(icmp6h,
301 sizeof(struct icmp6hdr), tmp_csum);
302 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
303 &fl6->daddr,
304 len, fl6->flowi6_proto,
305 tmp_csum);
306 }
307 ip6_push_pending_frames(sk);
308}
309
310struct icmpv6_msg {
311 struct sk_buff *skb;
312 int offset;
313 uint8_t type;
314};
315
316static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
317{
318 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
319 struct sk_buff *org_skb = msg->skb;
320 __wsum csum;
321
322 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
323 to, len);
324 skb->csum = csum_block_add(skb->csum, csum, odd);
325 if (!(msg->type & ICMPV6_INFOMSG_MASK))
326 nf_ct_attach(skb, org_skb);
327 return 0;
328}
329
330#if IS_ENABLED(CONFIG_IPV6_MIP6)
331static void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt)
332{
333 struct ipv6hdr *iph = ipv6_hdr(skb);
334 struct ipv6_destopt_hao *hao;
335 int off;
336
337 if (opt->dsthao) {
338 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
339 if (likely(off >= 0)) {
340 hao = (struct ipv6_destopt_hao *)
341 (skb_network_header(skb) + off);
342 swap(iph->saddr, hao->addr);
343 }
344 }
345}
346#else
347static inline void mip6_addr_swap(struct sk_buff *skb, const struct inet6_skb_parm *opt) {}
348#endif
349
350static struct dst_entry *icmpv6_route_lookup(struct net *net,
351 struct sk_buff *skb,
352 struct sock *sk,
353 struct flowi6 *fl6)
354{
355 struct dst_entry *dst, *dst2;
356 struct flowi6 fl2;
357 int err;
358
359 err = ip6_dst_lookup(net, sk, &dst, fl6);
360 if (err)
361 return ERR_PTR(err);
362
363 /*
364 * We won't send icmp if the destination is known
365 * anycast unless we need to treat anycast as unicast.
366 */
367 if (!READ_ONCE(net->ipv6.sysctl.icmpv6_error_anycast_as_unicast) &&
368 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(net, 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 /* The destination could be an external IP in Ext Hdr (SRv6, RPL, etc.),
428 * and ip6_null_entry could be set to skb if no route is found.
429 */
430 if (rt6 && rt6->rt6i_idev)
431 dev = rt6->rt6i_idev->dev;
432 }
433
434 return dev;
435}
436
437static int icmp6_iif(const struct sk_buff *skb)
438{
439 return icmp6_dev(skb)->ifindex;
440}
441
442/*
443 * Send an ICMP message in response to a packet in error
444 */
445void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
446 const struct in6_addr *force_saddr,
447 const struct inet6_skb_parm *parm)
448{
449 struct inet6_dev *idev = NULL;
450 struct ipv6hdr *hdr = ipv6_hdr(skb);
451 struct sock *sk;
452 struct net *net;
453 struct ipv6_pinfo *np;
454 const struct in6_addr *saddr = NULL;
455 struct dst_entry *dst;
456 struct icmp6hdr tmp_hdr;
457 struct flowi6 fl6;
458 struct icmpv6_msg msg;
459 struct ipcm6_cookie ipc6;
460 int iif = 0;
461 int addr_type = 0;
462 int len;
463 u32 mark;
464
465 if ((u8 *)hdr < skb->head ||
466 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
467 return;
468
469 if (!skb->dev)
470 return;
471 net = dev_net(skb->dev);
472 mark = IP6_REPLY_MARK(net, skb->mark);
473 /*
474 * Make sure we respect the rules
475 * i.e. RFC 1885 2.4(e)
476 * Rule (e.1) is enforced by not using icmp6_send
477 * in any code that processes icmp errors.
478 */
479 addr_type = ipv6_addr_type(&hdr->daddr);
480
481 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
482 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
483 saddr = &hdr->daddr;
484
485 /*
486 * Dest addr check
487 */
488
489 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
490 if (type != ICMPV6_PKT_TOOBIG &&
491 !(type == ICMPV6_PARAMPROB &&
492 code == ICMPV6_UNK_OPTION &&
493 (opt_unrec(skb, info))))
494 return;
495
496 saddr = NULL;
497 }
498
499 addr_type = ipv6_addr_type(&hdr->saddr);
500
501 /*
502 * Source addr check
503 */
504
505 if (__ipv6_addr_needs_scope_id(addr_type)) {
506 iif = icmp6_iif(skb);
507 } else {
508 /*
509 * The source device is used for looking up which routing table
510 * to use for sending an ICMP error.
511 */
512 iif = l3mdev_master_ifindex(skb->dev);
513 }
514
515 /*
516 * Must not send error if the source does not uniquely
517 * identify a single node (RFC2463 Section 2.4).
518 * We check unspecified / multicast addresses here,
519 * and anycast addresses will be checked later.
520 */
521 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
522 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
523 &hdr->saddr, &hdr->daddr);
524 return;
525 }
526
527 /*
528 * Never answer to a ICMP packet.
529 */
530 if (is_ineligible(skb)) {
531 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
532 &hdr->saddr, &hdr->daddr);
533 return;
534 }
535
536 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
537 local_bh_disable();
538
539 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
540 if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
541 goto out_bh_enable;
542
543 mip6_addr_swap(skb, parm);
544
545 sk = icmpv6_xmit_lock(net);
546 if (!sk)
547 goto out_bh_enable;
548
549 memset(&fl6, 0, sizeof(fl6));
550 fl6.flowi6_proto = IPPROTO_ICMPV6;
551 fl6.daddr = hdr->saddr;
552 if (force_saddr)
553 saddr = force_saddr;
554 if (saddr) {
555 fl6.saddr = *saddr;
556 } else if (!icmpv6_rt_has_prefsrc(sk, type, &fl6)) {
557 /* select a more meaningful saddr from input if */
558 struct net_device *in_netdev;
559
560 in_netdev = dev_get_by_index(net, parm->iif);
561 if (in_netdev) {
562 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
563 inet6_sk(sk)->srcprefs,
564 &fl6.saddr);
565 dev_put(in_netdev);
566 }
567 }
568 fl6.flowi6_mark = mark;
569 fl6.flowi6_oif = iif;
570 fl6.fl6_icmp_type = type;
571 fl6.fl6_icmp_code = code;
572 fl6.flowi6_uid = sock_net_uid(net, NULL);
573 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
574 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
575
576 np = inet6_sk(sk);
577
578 if (!icmpv6_xrlim_allow(sk, type, &fl6))
579 goto out;
580
581 tmp_hdr.icmp6_type = type;
582 tmp_hdr.icmp6_code = code;
583 tmp_hdr.icmp6_cksum = 0;
584 tmp_hdr.icmp6_pointer = htonl(info);
585
586 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
587 fl6.flowi6_oif = READ_ONCE(np->mcast_oif);
588 else if (!fl6.flowi6_oif)
589 fl6.flowi6_oif = READ_ONCE(np->ucast_oif);
590
591 ipcm6_init_sk(&ipc6, sk);
592 ipc6.sockc.mark = mark;
593 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
594
595 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
596 if (IS_ERR(dst))
597 goto out;
598
599 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
600
601 msg.skb = skb;
602 msg.offset = skb_network_offset(skb);
603 msg.type = type;
604
605 len = skb->len - msg.offset;
606 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
607 if (len < 0) {
608 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
609 &hdr->saddr, &hdr->daddr);
610 goto out_dst_release;
611 }
612
613 rcu_read_lock();
614 idev = __in6_dev_get(skb->dev);
615
616 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
617 len + sizeof(struct icmp6hdr),
618 sizeof(struct icmp6hdr),
619 &ipc6, &fl6, (struct rt6_info *)dst,
620 MSG_DONTWAIT)) {
621 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
622 ip6_flush_pending_frames(sk);
623 } else {
624 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
625 len + sizeof(struct icmp6hdr));
626 }
627 rcu_read_unlock();
628out_dst_release:
629 dst_release(dst);
630out:
631 icmpv6_xmit_unlock(sk);
632out_bh_enable:
633 local_bh_enable();
634}
635EXPORT_SYMBOL(icmp6_send);
636
637/* Slightly more convenient version of icmp6_send with drop reasons.
638 */
639void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos,
640 enum skb_drop_reason reason)
641{
642 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
643 kfree_skb_reason(skb, reason);
644}
645
646/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
647 * if sufficient data bytes are available
648 * @nhs is the size of the tunnel header(s) :
649 * Either an IPv4 header for SIT encap
650 * an IPv4 header + GRE header for GRE encap
651 */
652int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
653 unsigned int data_len)
654{
655 struct in6_addr temp_saddr;
656 struct rt6_info *rt;
657 struct sk_buff *skb2;
658 u32 info = 0;
659
660 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
661 return 1;
662
663 /* RFC 4884 (partial) support for ICMP extensions */
664 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
665 data_len = 0;
666
667 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
668
669 if (!skb2)
670 return 1;
671
672 skb_dst_drop(skb2);
673 skb_pull(skb2, nhs);
674 skb_reset_network_header(skb2);
675
676 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
677 skb, 0);
678
679 if (rt && rt->dst.dev)
680 skb2->dev = rt->dst.dev;
681
682 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
683
684 if (data_len) {
685 /* RFC 4884 (partial) support :
686 * insert 0 padding at the end, before the extensions
687 */
688 __skb_push(skb2, nhs);
689 skb_reset_network_header(skb2);
690 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
691 memset(skb2->data + data_len - nhs, 0, nhs);
692 /* RFC 4884 4.5 : Length is measured in 64-bit words,
693 * and stored in reserved[0]
694 */
695 info = (data_len/8) << 24;
696 }
697 if (type == ICMP_TIME_EXCEEDED)
698 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
699 info, &temp_saddr, IP6CB(skb2));
700 else
701 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
702 info, &temp_saddr, IP6CB(skb2));
703 if (rt)
704 ip6_rt_put(rt);
705
706 kfree_skb(skb2);
707
708 return 0;
709}
710EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
711
712static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb)
713{
714 struct net *net = dev_net(skb->dev);
715 struct sock *sk;
716 struct inet6_dev *idev;
717 struct ipv6_pinfo *np;
718 const struct in6_addr *saddr = NULL;
719 struct icmp6hdr *icmph = icmp6_hdr(skb);
720 struct icmp6hdr tmp_hdr;
721 struct flowi6 fl6;
722 struct icmpv6_msg msg;
723 struct dst_entry *dst;
724 struct ipcm6_cookie ipc6;
725 u32 mark = IP6_REPLY_MARK(net, skb->mark);
726 SKB_DR(reason);
727 bool acast;
728 u8 type;
729
730 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
731 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
732 return reason;
733
734 saddr = &ipv6_hdr(skb)->daddr;
735
736 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
737 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
738 return reason;
739
740 if (!ipv6_unicast_destination(skb) &&
741 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
742 saddr = NULL;
743
744 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
745 type = ICMPV6_EXT_ECHO_REPLY;
746 else
747 type = ICMPV6_ECHO_REPLY;
748
749 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
750 tmp_hdr.icmp6_type = type;
751
752 memset(&fl6, 0, sizeof(fl6));
753 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
754 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
755
756 fl6.flowi6_proto = IPPROTO_ICMPV6;
757 fl6.daddr = ipv6_hdr(skb)->saddr;
758 if (saddr)
759 fl6.saddr = *saddr;
760 fl6.flowi6_oif = icmp6_iif(skb);
761 fl6.fl6_icmp_type = type;
762 fl6.flowi6_mark = mark;
763 fl6.flowi6_uid = sock_net_uid(net, NULL);
764 security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
765
766 local_bh_disable();
767 sk = icmpv6_xmit_lock(net);
768 if (!sk)
769 goto out_bh_enable;
770 np = inet6_sk(sk);
771
772 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
773 fl6.flowi6_oif = READ_ONCE(np->mcast_oif);
774 else if (!fl6.flowi6_oif)
775 fl6.flowi6_oif = READ_ONCE(np->ucast_oif);
776
777 if (ip6_dst_lookup(net, sk, &dst, &fl6))
778 goto out;
779 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
780 if (IS_ERR(dst))
781 goto out;
782
783 /* Check the ratelimit */
784 if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
785 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
786 goto out_dst_release;
787
788 idev = __in6_dev_get(skb->dev);
789
790 msg.skb = skb;
791 msg.offset = 0;
792 msg.type = type;
793
794 ipcm6_init_sk(&ipc6, sk);
795 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
796 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
797 ipc6.sockc.mark = mark;
798
799 if (icmph->icmp6_type == ICMPV6_EXT_ECHO_REQUEST)
800 if (!icmp_build_probe(skb, (struct icmphdr *)&tmp_hdr))
801 goto out_dst_release;
802
803 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
804 skb->len + sizeof(struct icmp6hdr),
805 sizeof(struct icmp6hdr), &ipc6, &fl6,
806 (struct rt6_info *)dst, MSG_DONTWAIT)) {
807 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
808 ip6_flush_pending_frames(sk);
809 } else {
810 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
811 skb->len + sizeof(struct icmp6hdr));
812 reason = SKB_CONSUMED;
813 }
814out_dst_release:
815 dst_release(dst);
816out:
817 icmpv6_xmit_unlock(sk);
818out_bh_enable:
819 local_bh_enable();
820 return reason;
821}
822
823enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type,
824 u8 code, __be32 info)
825{
826 struct inet6_skb_parm *opt = IP6CB(skb);
827 struct net *net = dev_net(skb->dev);
828 const struct inet6_protocol *ipprot;
829 enum skb_drop_reason reason;
830 int inner_offset;
831 __be16 frag_off;
832 u8 nexthdr;
833
834 reason = pskb_may_pull_reason(skb, sizeof(struct ipv6hdr));
835 if (reason != SKB_NOT_DROPPED_YET)
836 goto out;
837
838 seg6_icmp_srh(skb, opt);
839
840 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
841 if (ipv6_ext_hdr(nexthdr)) {
842 /* now skip over extension headers */
843 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
844 &nexthdr, &frag_off);
845 if (inner_offset < 0) {
846 SKB_DR_SET(reason, IPV6_BAD_EXTHDR);
847 goto out;
848 }
849 } else {
850 inner_offset = sizeof(struct ipv6hdr);
851 }
852
853 /* Checkin header including 8 bytes of inner protocol header. */
854 reason = pskb_may_pull_reason(skb, inner_offset + 8);
855 if (reason != SKB_NOT_DROPPED_YET)
856 goto out;
857
858 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
859 Without this we will not able f.e. to make source routed
860 pmtu discovery.
861 Corresponding argument (opt) to notifiers is already added.
862 --ANK (980726)
863 */
864
865 ipprot = rcu_dereference(inet6_protos[nexthdr]);
866 if (ipprot && ipprot->err_handler)
867 ipprot->err_handler(skb, opt, type, code, inner_offset, info);
868
869 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
870 return SKB_CONSUMED;
871
872out:
873 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
874 return reason;
875}
876
877/*
878 * Handle icmp messages
879 */
880
881static int icmpv6_rcv(struct sk_buff *skb)
882{
883 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
884 struct net *net = dev_net(skb->dev);
885 struct net_device *dev = icmp6_dev(skb);
886 struct inet6_dev *idev = __in6_dev_get(dev);
887 const struct in6_addr *saddr, *daddr;
888 struct icmp6hdr *hdr;
889 u8 type;
890
891 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
892 struct sec_path *sp = skb_sec_path(skb);
893 int nh;
894
895 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
896 XFRM_STATE_ICMP)) {
897 reason = SKB_DROP_REASON_XFRM_POLICY;
898 goto drop_no_count;
899 }
900
901 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
902 goto drop_no_count;
903
904 nh = skb_network_offset(skb);
905 skb_set_network_header(skb, sizeof(*hdr));
906
907 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN,
908 skb)) {
909 reason = SKB_DROP_REASON_XFRM_POLICY;
910 goto drop_no_count;
911 }
912
913 skb_set_network_header(skb, nh);
914 }
915
916 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
917
918 saddr = &ipv6_hdr(skb)->saddr;
919 daddr = &ipv6_hdr(skb)->daddr;
920
921 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
922 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
923 saddr, daddr);
924 goto csum_error;
925 }
926
927 if (!pskb_pull(skb, sizeof(*hdr)))
928 goto discard_it;
929
930 hdr = icmp6_hdr(skb);
931
932 type = hdr->icmp6_type;
933
934 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
935
936 switch (type) {
937 case ICMPV6_ECHO_REQUEST:
938 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
939 reason = icmpv6_echo_reply(skb);
940 break;
941 case ICMPV6_EXT_ECHO_REQUEST:
942 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all &&
943 READ_ONCE(net->ipv4.sysctl_icmp_echo_enable_probe))
944 reason = icmpv6_echo_reply(skb);
945 break;
946
947 case ICMPV6_ECHO_REPLY:
948 reason = ping_rcv(skb);
949 break;
950
951 case ICMPV6_EXT_ECHO_REPLY:
952 reason = ping_rcv(skb);
953 break;
954
955 case ICMPV6_PKT_TOOBIG:
956 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
957 standard destination cache. Seems, only "advanced"
958 destination cache will allow to solve this problem
959 --ANK (980726)
960 */
961 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
962 goto discard_it;
963 hdr = icmp6_hdr(skb);
964
965 /* to notify */
966 fallthrough;
967 case ICMPV6_DEST_UNREACH:
968 case ICMPV6_TIME_EXCEED:
969 case ICMPV6_PARAMPROB:
970 reason = icmpv6_notify(skb, type, hdr->icmp6_code,
971 hdr->icmp6_mtu);
972 break;
973
974 case NDISC_ROUTER_SOLICITATION:
975 case NDISC_ROUTER_ADVERTISEMENT:
976 case NDISC_NEIGHBOUR_SOLICITATION:
977 case NDISC_NEIGHBOUR_ADVERTISEMENT:
978 case NDISC_REDIRECT:
979 reason = ndisc_rcv(skb);
980 break;
981
982 case ICMPV6_MGM_QUERY:
983 igmp6_event_query(skb);
984 return 0;
985
986 case ICMPV6_MGM_REPORT:
987 igmp6_event_report(skb);
988 return 0;
989
990 case ICMPV6_MGM_REDUCTION:
991 case ICMPV6_NI_QUERY:
992 case ICMPV6_NI_REPLY:
993 case ICMPV6_MLD2_REPORT:
994 case ICMPV6_DHAAD_REQUEST:
995 case ICMPV6_DHAAD_REPLY:
996 case ICMPV6_MOBILE_PREFIX_SOL:
997 case ICMPV6_MOBILE_PREFIX_ADV:
998 break;
999
1000 default:
1001 /* informational */
1002 if (type & ICMPV6_INFOMSG_MASK)
1003 break;
1004
1005 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
1006 saddr, daddr);
1007
1008 /*
1009 * error of unknown type.
1010 * must pass to upper level
1011 */
1012
1013 reason = icmpv6_notify(skb, type, hdr->icmp6_code,
1014 hdr->icmp6_mtu);
1015 }
1016
1017 /* until the v6 path can be better sorted assume failure and
1018 * preserve the status quo behaviour for the rest of the paths to here
1019 */
1020 if (reason)
1021 kfree_skb_reason(skb, reason);
1022 else
1023 consume_skb(skb);
1024
1025 return 0;
1026
1027csum_error:
1028 reason = SKB_DROP_REASON_ICMP_CSUM;
1029 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
1030discard_it:
1031 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
1032drop_no_count:
1033 kfree_skb_reason(skb, reason);
1034 return 0;
1035}
1036
1037void icmpv6_flow_init(const struct sock *sk, struct flowi6 *fl6, u8 type,
1038 const struct in6_addr *saddr,
1039 const struct in6_addr *daddr, int oif)
1040{
1041 memset(fl6, 0, sizeof(*fl6));
1042 fl6->saddr = *saddr;
1043 fl6->daddr = *daddr;
1044 fl6->flowi6_proto = IPPROTO_ICMPV6;
1045 fl6->fl6_icmp_type = type;
1046 fl6->fl6_icmp_code = 0;
1047 fl6->flowi6_oif = oif;
1048 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1049}
1050
1051int __init icmpv6_init(void)
1052{
1053 struct sock *sk;
1054 int err, i;
1055
1056 for_each_possible_cpu(i) {
1057 err = inet_ctl_sock_create(&sk, PF_INET6,
1058 SOCK_RAW, IPPROTO_ICMPV6, &init_net);
1059 if (err < 0) {
1060 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
1061 err);
1062 return err;
1063 }
1064
1065 per_cpu(ipv6_icmp_sk, i) = sk;
1066
1067 /* Enough space for 2 64K ICMP packets, including
1068 * sk_buff struct overhead.
1069 */
1070 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1071 }
1072
1073 err = -EAGAIN;
1074 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1075 goto fail;
1076
1077 err = inet6_register_icmp_sender(icmp6_send);
1078 if (err)
1079 goto sender_reg_err;
1080 return 0;
1081
1082sender_reg_err:
1083 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1084fail:
1085 pr_err("Failed to register ICMP6 protocol\n");
1086 return err;
1087}
1088
1089void icmpv6_cleanup(void)
1090{
1091 inet6_unregister_icmp_sender(icmp6_send);
1092 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1093}
1094
1095
1096static const struct icmp6_err {
1097 int err;
1098 int fatal;
1099} tab_unreach[] = {
1100 { /* NOROUTE */
1101 .err = ENETUNREACH,
1102 .fatal = 0,
1103 },
1104 { /* ADM_PROHIBITED */
1105 .err = EACCES,
1106 .fatal = 1,
1107 },
1108 { /* Was NOT_NEIGHBOUR, now reserved */
1109 .err = EHOSTUNREACH,
1110 .fatal = 0,
1111 },
1112 { /* ADDR_UNREACH */
1113 .err = EHOSTUNREACH,
1114 .fatal = 0,
1115 },
1116 { /* PORT_UNREACH */
1117 .err = ECONNREFUSED,
1118 .fatal = 1,
1119 },
1120 { /* POLICY_FAIL */
1121 .err = EACCES,
1122 .fatal = 1,
1123 },
1124 { /* REJECT_ROUTE */
1125 .err = EACCES,
1126 .fatal = 1,
1127 },
1128};
1129
1130int icmpv6_err_convert(u8 type, u8 code, int *err)
1131{
1132 int fatal = 0;
1133
1134 *err = EPROTO;
1135
1136 switch (type) {
1137 case ICMPV6_DEST_UNREACH:
1138 fatal = 1;
1139 if (code < ARRAY_SIZE(tab_unreach)) {
1140 *err = tab_unreach[code].err;
1141 fatal = tab_unreach[code].fatal;
1142 }
1143 break;
1144
1145 case ICMPV6_PKT_TOOBIG:
1146 *err = EMSGSIZE;
1147 break;
1148
1149 case ICMPV6_PARAMPROB:
1150 *err = EPROTO;
1151 fatal = 1;
1152 break;
1153
1154 case ICMPV6_TIME_EXCEED:
1155 *err = EHOSTUNREACH;
1156 break;
1157 }
1158
1159 return fatal;
1160}
1161EXPORT_SYMBOL(icmpv6_err_convert);
1162
1163#ifdef CONFIG_SYSCTL
1164static struct ctl_table ipv6_icmp_table_template[] = {
1165 {
1166 .procname = "ratelimit",
1167 .data = &init_net.ipv6.sysctl.icmpv6_time,
1168 .maxlen = sizeof(int),
1169 .mode = 0644,
1170 .proc_handler = proc_dointvec_ms_jiffies,
1171 },
1172 {
1173 .procname = "echo_ignore_all",
1174 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1175 .maxlen = sizeof(u8),
1176 .mode = 0644,
1177 .proc_handler = proc_dou8vec_minmax,
1178 },
1179 {
1180 .procname = "echo_ignore_multicast",
1181 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1182 .maxlen = sizeof(u8),
1183 .mode = 0644,
1184 .proc_handler = proc_dou8vec_minmax,
1185 },
1186 {
1187 .procname = "echo_ignore_anycast",
1188 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1189 .maxlen = sizeof(u8),
1190 .mode = 0644,
1191 .proc_handler = proc_dou8vec_minmax,
1192 },
1193 {
1194 .procname = "ratemask",
1195 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1196 .maxlen = ICMPV6_MSG_MAX + 1,
1197 .mode = 0644,
1198 .proc_handler = proc_do_large_bitmap,
1199 },
1200 {
1201 .procname = "error_anycast_as_unicast",
1202 .data = &init_net.ipv6.sysctl.icmpv6_error_anycast_as_unicast,
1203 .maxlen = sizeof(u8),
1204 .mode = 0644,
1205 .proc_handler = proc_dou8vec_minmax,
1206 .extra1 = SYSCTL_ZERO,
1207 .extra2 = SYSCTL_ONE,
1208 },
1209 { },
1210};
1211
1212struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1213{
1214 struct ctl_table *table;
1215
1216 table = kmemdup(ipv6_icmp_table_template,
1217 sizeof(ipv6_icmp_table_template),
1218 GFP_KERNEL);
1219
1220 if (table) {
1221 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1222 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1223 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1224 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1225 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1226 table[5].data = &net->ipv6.sysctl.icmpv6_error_anycast_as_unicast;
1227 }
1228 return table;
1229}
1230
1231size_t ipv6_icmp_sysctl_table_size(void)
1232{
1233 return ARRAY_SIZE(ipv6_icmp_table_template);
1234}
1235#endif
1/*
2 * Internet Control Message Protocol (ICMPv6)
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * Based on net/ipv4/icmp.c
9 *
10 * RFC 1885
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18/*
19 * Changes:
20 *
21 * Andi Kleen : exception handling
22 * Andi Kleen add rate limits. never reply to a icmp.
23 * add more length checks and other fixes.
24 * yoshfuji : ensure to sent parameter problem for
25 * fragments.
26 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
27 * Randy Dunlap and
28 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
29 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
30 */
31
32#include <linux/module.h>
33#include <linux/errno.h>
34#include <linux/types.h>
35#include <linux/socket.h>
36#include <linux/in.h>
37#include <linux/kernel.h>
38#include <linux/sockios.h>
39#include <linux/net.h>
40#include <linux/skbuff.h>
41#include <linux/init.h>
42#include <linux/netfilter.h>
43#include <linux/slab.h>
44
45#ifdef CONFIG_SYSCTL
46#include <linux/sysctl.h>
47#endif
48
49#include <linux/inet.h>
50#include <linux/netdevice.h>
51#include <linux/icmpv6.h>
52
53#include <net/ip.h>
54#include <net/sock.h>
55
56#include <net/ipv6.h>
57#include <net/ip6_checksum.h>
58#include <net/protocol.h>
59#include <net/raw.h>
60#include <net/rawv6.h>
61#include <net/transp_v6.h>
62#include <net/ip6_route.h>
63#include <net/addrconf.h>
64#include <net/icmp.h>
65#include <net/xfrm.h>
66#include <net/inet_common.h>
67
68#include <asm/uaccess.h>
69#include <asm/system.h>
70
71/*
72 * The ICMP socket(s). This is the most convenient way to flow control
73 * our ICMP output as well as maintain a clean interface throughout
74 * all layers. All Socketless IP sends will soon be gone.
75 *
76 * On SMP we have one ICMP socket per-cpu.
77 */
78static inline struct sock *icmpv6_sk(struct net *net)
79{
80 return net->ipv6.icmp_sk[smp_processor_id()];
81}
82
83static int icmpv6_rcv(struct sk_buff *skb);
84
85static const struct inet6_protocol icmpv6_protocol = {
86 .handler = icmpv6_rcv,
87 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
88};
89
90static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
91{
92 struct sock *sk;
93
94 local_bh_disable();
95
96 sk = icmpv6_sk(net);
97 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
98 /* This can happen if the output path (f.e. SIT or
99 * ip6ip6 tunnel) signals dst_link_failure() for an
100 * outgoing ICMP6 packet.
101 */
102 local_bh_enable();
103 return NULL;
104 }
105 return sk;
106}
107
108static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
109{
110 spin_unlock_bh(&sk->sk_lock.slock);
111}
112
113/*
114 * Slightly more convenient version of icmpv6_send.
115 */
116void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
117{
118 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
119 kfree_skb(skb);
120}
121
122/*
123 * Figure out, may we reply to this packet with icmp error.
124 *
125 * We do not reply, if:
126 * - it was icmp error message.
127 * - it is truncated, so that it is known, that protocol is ICMPV6
128 * (i.e. in the middle of some exthdr)
129 *
130 * --ANK (980726)
131 */
132
133static int is_ineligible(struct sk_buff *skb)
134{
135 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
136 int len = skb->len - ptr;
137 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
138
139 if (len < 0)
140 return 1;
141
142 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr);
143 if (ptr < 0)
144 return 0;
145 if (nexthdr == IPPROTO_ICMPV6) {
146 u8 _type, *tp;
147 tp = skb_header_pointer(skb,
148 ptr+offsetof(struct icmp6hdr, icmp6_type),
149 sizeof(_type), &_type);
150 if (tp == NULL ||
151 !(*tp & ICMPV6_INFOMSG_MASK))
152 return 1;
153 }
154 return 0;
155}
156
157/*
158 * Check the ICMP output rate limit
159 */
160static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
161 struct flowi6 *fl6)
162{
163 struct dst_entry *dst;
164 struct net *net = sock_net(sk);
165 bool res = false;
166
167 /* Informational messages are not limited. */
168 if (type & ICMPV6_INFOMSG_MASK)
169 return true;
170
171 /* Do not limit pmtu discovery, it would break it. */
172 if (type == ICMPV6_PKT_TOOBIG)
173 return true;
174
175 /*
176 * Look up the output route.
177 * XXX: perhaps the expire for routing entries cloned by
178 * this lookup should be more aggressive (not longer than timeout).
179 */
180 dst = ip6_route_output(net, sk, fl6);
181 if (dst->error) {
182 IP6_INC_STATS(net, ip6_dst_idev(dst),
183 IPSTATS_MIB_OUTNOROUTES);
184 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
185 res = true;
186 } else {
187 struct rt6_info *rt = (struct rt6_info *)dst;
188 int tmo = net->ipv6.sysctl.icmpv6_time;
189
190 /* Give more bandwidth to wider prefixes. */
191 if (rt->rt6i_dst.plen < 128)
192 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
193
194 if (!rt->rt6i_peer)
195 rt6_bind_peer(rt, 1);
196 res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo);
197 }
198 dst_release(dst);
199 return res;
200}
201
202/*
203 * an inline helper for the "simple" if statement below
204 * checks if parameter problem report is caused by an
205 * unrecognized IPv6 option that has the Option Type
206 * highest-order two bits set to 10
207 */
208
209static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset)
210{
211 u8 _optval, *op;
212
213 offset += skb_network_offset(skb);
214 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
215 if (op == NULL)
216 return 1;
217 return (*op & 0xC0) == 0x80;
218}
219
220static int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, struct icmp6hdr *thdr, int len)
221{
222 struct sk_buff *skb;
223 struct icmp6hdr *icmp6h;
224 int err = 0;
225
226 if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
227 goto out;
228
229 icmp6h = icmp6_hdr(skb);
230 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
231 icmp6h->icmp6_cksum = 0;
232
233 if (skb_queue_len(&sk->sk_write_queue) == 1) {
234 skb->csum = csum_partial(icmp6h,
235 sizeof(struct icmp6hdr), skb->csum);
236 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
237 &fl6->daddr,
238 len, fl6->flowi6_proto,
239 skb->csum);
240 } else {
241 __wsum tmp_csum = 0;
242
243 skb_queue_walk(&sk->sk_write_queue, skb) {
244 tmp_csum = csum_add(tmp_csum, skb->csum);
245 }
246
247 tmp_csum = csum_partial(icmp6h,
248 sizeof(struct icmp6hdr), tmp_csum);
249 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
250 &fl6->daddr,
251 len, fl6->flowi6_proto,
252 tmp_csum);
253 }
254 ip6_push_pending_frames(sk);
255out:
256 return err;
257}
258
259struct icmpv6_msg {
260 struct sk_buff *skb;
261 int offset;
262 uint8_t type;
263};
264
265static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
266{
267 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
268 struct sk_buff *org_skb = msg->skb;
269 __wsum csum = 0;
270
271 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
272 to, len, csum);
273 skb->csum = csum_block_add(skb->csum, csum, odd);
274 if (!(msg->type & ICMPV6_INFOMSG_MASK))
275 nf_ct_attach(skb, org_skb);
276 return 0;
277}
278
279#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
280static void mip6_addr_swap(struct sk_buff *skb)
281{
282 struct ipv6hdr *iph = ipv6_hdr(skb);
283 struct inet6_skb_parm *opt = IP6CB(skb);
284 struct ipv6_destopt_hao *hao;
285 struct in6_addr tmp;
286 int off;
287
288 if (opt->dsthao) {
289 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
290 if (likely(off >= 0)) {
291 hao = (struct ipv6_destopt_hao *)
292 (skb_network_header(skb) + off);
293 ipv6_addr_copy(&tmp, &iph->saddr);
294 ipv6_addr_copy(&iph->saddr, &hao->addr);
295 ipv6_addr_copy(&hao->addr, &tmp);
296 }
297 }
298}
299#else
300static inline void mip6_addr_swap(struct sk_buff *skb) {}
301#endif
302
303static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb,
304 struct sock *sk, struct flowi6 *fl6)
305{
306 struct dst_entry *dst, *dst2;
307 struct flowi6 fl2;
308 int err;
309
310 err = ip6_dst_lookup(sk, &dst, fl6);
311 if (err)
312 return ERR_PTR(err);
313
314 /*
315 * We won't send icmp if the destination is known
316 * anycast.
317 */
318 if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) {
319 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n");
320 dst_release(dst);
321 return ERR_PTR(-EINVAL);
322 }
323
324 /* No need to clone since we're just using its address. */
325 dst2 = dst;
326
327 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
328 if (!IS_ERR(dst)) {
329 if (dst != dst2)
330 return dst;
331 } else {
332 if (PTR_ERR(dst) == -EPERM)
333 dst = NULL;
334 else
335 return dst;
336 }
337
338 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
339 if (err)
340 goto relookup_failed;
341
342 err = ip6_dst_lookup(sk, &dst2, &fl2);
343 if (err)
344 goto relookup_failed;
345
346 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
347 if (!IS_ERR(dst2)) {
348 dst_release(dst);
349 dst = dst2;
350 } else {
351 err = PTR_ERR(dst2);
352 if (err == -EPERM) {
353 dst_release(dst);
354 return dst2;
355 } else
356 goto relookup_failed;
357 }
358
359relookup_failed:
360 if (dst)
361 return dst;
362 return ERR_PTR(err);
363}
364
365/*
366 * Send an ICMP message in response to a packet in error
367 */
368void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
369{
370 struct net *net = dev_net(skb->dev);
371 struct inet6_dev *idev = NULL;
372 struct ipv6hdr *hdr = ipv6_hdr(skb);
373 struct sock *sk;
374 struct ipv6_pinfo *np;
375 const struct in6_addr *saddr = NULL;
376 struct dst_entry *dst;
377 struct icmp6hdr tmp_hdr;
378 struct flowi6 fl6;
379 struct icmpv6_msg msg;
380 int iif = 0;
381 int addr_type = 0;
382 int len;
383 int hlimit;
384 int err = 0;
385
386 if ((u8 *)hdr < skb->head ||
387 (skb->network_header + sizeof(*hdr)) > skb->tail)
388 return;
389
390 /*
391 * Make sure we respect the rules
392 * i.e. RFC 1885 2.4(e)
393 * Rule (e.1) is enforced by not using icmpv6_send
394 * in any code that processes icmp errors.
395 */
396 addr_type = ipv6_addr_type(&hdr->daddr);
397
398 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0))
399 saddr = &hdr->daddr;
400
401 /*
402 * Dest addr check
403 */
404
405 if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) {
406 if (type != ICMPV6_PKT_TOOBIG &&
407 !(type == ICMPV6_PARAMPROB &&
408 code == ICMPV6_UNK_OPTION &&
409 (opt_unrec(skb, info))))
410 return;
411
412 saddr = NULL;
413 }
414
415 addr_type = ipv6_addr_type(&hdr->saddr);
416
417 /*
418 * Source addr check
419 */
420
421 if (addr_type & IPV6_ADDR_LINKLOCAL)
422 iif = skb->dev->ifindex;
423
424 /*
425 * Must not send error if the source does not uniquely
426 * identify a single node (RFC2463 Section 2.4).
427 * We check unspecified / multicast addresses here,
428 * and anycast addresses will be checked later.
429 */
430 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
431 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n");
432 return;
433 }
434
435 /*
436 * Never answer to a ICMP packet.
437 */
438 if (is_ineligible(skb)) {
439 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n");
440 return;
441 }
442
443 mip6_addr_swap(skb);
444
445 memset(&fl6, 0, sizeof(fl6));
446 fl6.flowi6_proto = IPPROTO_ICMPV6;
447 ipv6_addr_copy(&fl6.daddr, &hdr->saddr);
448 if (saddr)
449 ipv6_addr_copy(&fl6.saddr, saddr);
450 fl6.flowi6_oif = iif;
451 fl6.fl6_icmp_type = type;
452 fl6.fl6_icmp_code = code;
453 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
454
455 sk = icmpv6_xmit_lock(net);
456 if (sk == NULL)
457 return;
458 np = inet6_sk(sk);
459
460 if (!icmpv6_xrlim_allow(sk, type, &fl6))
461 goto out;
462
463 tmp_hdr.icmp6_type = type;
464 tmp_hdr.icmp6_code = code;
465 tmp_hdr.icmp6_cksum = 0;
466 tmp_hdr.icmp6_pointer = htonl(info);
467
468 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
469 fl6.flowi6_oif = np->mcast_oif;
470
471 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
472 if (IS_ERR(dst))
473 goto out;
474
475 if (ipv6_addr_is_multicast(&fl6.daddr))
476 hlimit = np->mcast_hops;
477 else
478 hlimit = np->hop_limit;
479 if (hlimit < 0)
480 hlimit = ip6_dst_hoplimit(dst);
481
482 msg.skb = skb;
483 msg.offset = skb_network_offset(skb);
484 msg.type = type;
485
486 len = skb->len - msg.offset;
487 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
488 if (len < 0) {
489 LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n");
490 goto out_dst_release;
491 }
492
493 idev = in6_dev_get(skb->dev);
494
495 err = ip6_append_data(sk, icmpv6_getfrag, &msg,
496 len + sizeof(struct icmp6hdr),
497 sizeof(struct icmp6hdr), hlimit,
498 np->tclass, NULL, &fl6, (struct rt6_info*)dst,
499 MSG_DONTWAIT, np->dontfrag);
500 if (err) {
501 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
502 ip6_flush_pending_frames(sk);
503 goto out_put;
504 }
505 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, len + sizeof(struct icmp6hdr));
506
507out_put:
508 if (likely(idev != NULL))
509 in6_dev_put(idev);
510out_dst_release:
511 dst_release(dst);
512out:
513 icmpv6_xmit_unlock(sk);
514}
515
516EXPORT_SYMBOL(icmpv6_send);
517
518static void icmpv6_echo_reply(struct sk_buff *skb)
519{
520 struct net *net = dev_net(skb->dev);
521 struct sock *sk;
522 struct inet6_dev *idev;
523 struct ipv6_pinfo *np;
524 const struct in6_addr *saddr = NULL;
525 struct icmp6hdr *icmph = icmp6_hdr(skb);
526 struct icmp6hdr tmp_hdr;
527 struct flowi6 fl6;
528 struct icmpv6_msg msg;
529 struct dst_entry *dst;
530 int err = 0;
531 int hlimit;
532
533 saddr = &ipv6_hdr(skb)->daddr;
534
535 if (!ipv6_unicast_destination(skb))
536 saddr = NULL;
537
538 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
539 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
540
541 memset(&fl6, 0, sizeof(fl6));
542 fl6.flowi6_proto = IPPROTO_ICMPV6;
543 ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->saddr);
544 if (saddr)
545 ipv6_addr_copy(&fl6.saddr, saddr);
546 fl6.flowi6_oif = skb->dev->ifindex;
547 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
548 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
549
550 sk = icmpv6_xmit_lock(net);
551 if (sk == NULL)
552 return;
553 np = inet6_sk(sk);
554
555 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
556 fl6.flowi6_oif = np->mcast_oif;
557
558 err = ip6_dst_lookup(sk, &dst, &fl6);
559 if (err)
560 goto out;
561 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
562 if (IS_ERR(dst))
563 goto out;
564
565 if (ipv6_addr_is_multicast(&fl6.daddr))
566 hlimit = np->mcast_hops;
567 else
568 hlimit = np->hop_limit;
569 if (hlimit < 0)
570 hlimit = ip6_dst_hoplimit(dst);
571
572 idev = in6_dev_get(skb->dev);
573
574 msg.skb = skb;
575 msg.offset = 0;
576 msg.type = ICMPV6_ECHO_REPLY;
577
578 err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
579 sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6,
580 (struct rt6_info*)dst, MSG_DONTWAIT,
581 np->dontfrag);
582
583 if (err) {
584 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
585 ip6_flush_pending_frames(sk);
586 goto out_put;
587 }
588 err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, skb->len + sizeof(struct icmp6hdr));
589
590out_put:
591 if (likely(idev != NULL))
592 in6_dev_put(idev);
593 dst_release(dst);
594out:
595 icmpv6_xmit_unlock(sk);
596}
597
598static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
599{
600 const struct inet6_protocol *ipprot;
601 int inner_offset;
602 int hash;
603 u8 nexthdr;
604
605 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
606 return;
607
608 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
609 if (ipv6_ext_hdr(nexthdr)) {
610 /* now skip over extension headers */
611 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
612 if (inner_offset<0)
613 return;
614 } else {
615 inner_offset = sizeof(struct ipv6hdr);
616 }
617
618 /* Checkin header including 8 bytes of inner protocol header. */
619 if (!pskb_may_pull(skb, inner_offset+8))
620 return;
621
622 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
623 Without this we will not able f.e. to make source routed
624 pmtu discovery.
625 Corresponding argument (opt) to notifiers is already added.
626 --ANK (980726)
627 */
628
629 hash = nexthdr & (MAX_INET_PROTOS - 1);
630
631 rcu_read_lock();
632 ipprot = rcu_dereference(inet6_protos[hash]);
633 if (ipprot && ipprot->err_handler)
634 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
635 rcu_read_unlock();
636
637 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
638}
639
640/*
641 * Handle icmp messages
642 */
643
644static int icmpv6_rcv(struct sk_buff *skb)
645{
646 struct net_device *dev = skb->dev;
647 struct inet6_dev *idev = __in6_dev_get(dev);
648 const struct in6_addr *saddr, *daddr;
649 const struct ipv6hdr *orig_hdr;
650 struct icmp6hdr *hdr;
651 u8 type;
652
653 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
654 struct sec_path *sp = skb_sec_path(skb);
655 int nh;
656
657 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
658 XFRM_STATE_ICMP))
659 goto drop_no_count;
660
661 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr)))
662 goto drop_no_count;
663
664 nh = skb_network_offset(skb);
665 skb_set_network_header(skb, sizeof(*hdr));
666
667 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
668 goto drop_no_count;
669
670 skb_set_network_header(skb, nh);
671 }
672
673 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
674
675 saddr = &ipv6_hdr(skb)->saddr;
676 daddr = &ipv6_hdr(skb)->daddr;
677
678 /* Perform checksum. */
679 switch (skb->ip_summed) {
680 case CHECKSUM_COMPLETE:
681 if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
682 skb->csum))
683 break;
684 /* fall through */
685 case CHECKSUM_NONE:
686 skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len,
687 IPPROTO_ICMPV6, 0));
688 if (__skb_checksum_complete(skb)) {
689 LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n",
690 saddr, daddr);
691 goto discard_it;
692 }
693 }
694
695 if (!pskb_pull(skb, sizeof(*hdr)))
696 goto discard_it;
697
698 hdr = icmp6_hdr(skb);
699
700 type = hdr->icmp6_type;
701
702 ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
703
704 switch (type) {
705 case ICMPV6_ECHO_REQUEST:
706 icmpv6_echo_reply(skb);
707 break;
708
709 case ICMPV6_ECHO_REPLY:
710 /* we couldn't care less */
711 break;
712
713 case ICMPV6_PKT_TOOBIG:
714 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
715 standard destination cache. Seems, only "advanced"
716 destination cache will allow to solve this problem
717 --ANK (980726)
718 */
719 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
720 goto discard_it;
721 hdr = icmp6_hdr(skb);
722 orig_hdr = (struct ipv6hdr *) (hdr + 1);
723 rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev,
724 ntohl(hdr->icmp6_mtu));
725
726 /*
727 * Drop through to notify
728 */
729
730 case ICMPV6_DEST_UNREACH:
731 case ICMPV6_TIME_EXCEED:
732 case ICMPV6_PARAMPROB:
733 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
734 break;
735
736 case NDISC_ROUTER_SOLICITATION:
737 case NDISC_ROUTER_ADVERTISEMENT:
738 case NDISC_NEIGHBOUR_SOLICITATION:
739 case NDISC_NEIGHBOUR_ADVERTISEMENT:
740 case NDISC_REDIRECT:
741 ndisc_rcv(skb);
742 break;
743
744 case ICMPV6_MGM_QUERY:
745 igmp6_event_query(skb);
746 break;
747
748 case ICMPV6_MGM_REPORT:
749 igmp6_event_report(skb);
750 break;
751
752 case ICMPV6_MGM_REDUCTION:
753 case ICMPV6_NI_QUERY:
754 case ICMPV6_NI_REPLY:
755 case ICMPV6_MLD2_REPORT:
756 case ICMPV6_DHAAD_REQUEST:
757 case ICMPV6_DHAAD_REPLY:
758 case ICMPV6_MOBILE_PREFIX_SOL:
759 case ICMPV6_MOBILE_PREFIX_ADV:
760 break;
761
762 default:
763 LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n");
764
765 /* informational */
766 if (type & ICMPV6_INFOMSG_MASK)
767 break;
768
769 /*
770 * error of unknown type.
771 * must pass to upper level
772 */
773
774 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
775 }
776
777 kfree_skb(skb);
778 return 0;
779
780discard_it:
781 ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
782drop_no_count:
783 kfree_skb(skb);
784 return 0;
785}
786
787void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
788 u8 type,
789 const struct in6_addr *saddr,
790 const struct in6_addr *daddr,
791 int oif)
792{
793 memset(fl6, 0, sizeof(*fl6));
794 ipv6_addr_copy(&fl6->saddr, saddr);
795 ipv6_addr_copy(&fl6->daddr, daddr);
796 fl6->flowi6_proto = IPPROTO_ICMPV6;
797 fl6->fl6_icmp_type = type;
798 fl6->fl6_icmp_code = 0;
799 fl6->flowi6_oif = oif;
800 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
801}
802
803/*
804 * Special lock-class for __icmpv6_sk:
805 */
806static struct lock_class_key icmpv6_socket_sk_dst_lock_key;
807
808static int __net_init icmpv6_sk_init(struct net *net)
809{
810 struct sock *sk;
811 int err, i, j;
812
813 net->ipv6.icmp_sk =
814 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
815 if (net->ipv6.icmp_sk == NULL)
816 return -ENOMEM;
817
818 for_each_possible_cpu(i) {
819 err = inet_ctl_sock_create(&sk, PF_INET6,
820 SOCK_RAW, IPPROTO_ICMPV6, net);
821 if (err < 0) {
822 printk(KERN_ERR
823 "Failed to initialize the ICMP6 control socket "
824 "(err %d).\n",
825 err);
826 goto fail;
827 }
828
829 net->ipv6.icmp_sk[i] = sk;
830
831 /*
832 * Split off their lock-class, because sk->sk_dst_lock
833 * gets used from softirqs, which is safe for
834 * __icmpv6_sk (because those never get directly used
835 * via userspace syscalls), but unsafe for normal sockets.
836 */
837 lockdep_set_class(&sk->sk_dst_lock,
838 &icmpv6_socket_sk_dst_lock_key);
839
840 /* Enough space for 2 64K ICMP packets, including
841 * sk_buff struct overhead.
842 */
843 sk->sk_sndbuf =
844 (2 * ((64 * 1024) + sizeof(struct sk_buff)));
845 }
846 return 0;
847
848 fail:
849 for (j = 0; j < i; j++)
850 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
851 kfree(net->ipv6.icmp_sk);
852 return err;
853}
854
855static void __net_exit icmpv6_sk_exit(struct net *net)
856{
857 int i;
858
859 for_each_possible_cpu(i) {
860 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
861 }
862 kfree(net->ipv6.icmp_sk);
863}
864
865static struct pernet_operations icmpv6_sk_ops = {
866 .init = icmpv6_sk_init,
867 .exit = icmpv6_sk_exit,
868};
869
870int __init icmpv6_init(void)
871{
872 int err;
873
874 err = register_pernet_subsys(&icmpv6_sk_ops);
875 if (err < 0)
876 return err;
877
878 err = -EAGAIN;
879 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
880 goto fail;
881 return 0;
882
883fail:
884 printk(KERN_ERR "Failed to register ICMP6 protocol\n");
885 unregister_pernet_subsys(&icmpv6_sk_ops);
886 return err;
887}
888
889void icmpv6_cleanup(void)
890{
891 unregister_pernet_subsys(&icmpv6_sk_ops);
892 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
893}
894
895
896static const struct icmp6_err {
897 int err;
898 int fatal;
899} tab_unreach[] = {
900 { /* NOROUTE */
901 .err = ENETUNREACH,
902 .fatal = 0,
903 },
904 { /* ADM_PROHIBITED */
905 .err = EACCES,
906 .fatal = 1,
907 },
908 { /* Was NOT_NEIGHBOUR, now reserved */
909 .err = EHOSTUNREACH,
910 .fatal = 0,
911 },
912 { /* ADDR_UNREACH */
913 .err = EHOSTUNREACH,
914 .fatal = 0,
915 },
916 { /* PORT_UNREACH */
917 .err = ECONNREFUSED,
918 .fatal = 1,
919 },
920};
921
922int icmpv6_err_convert(u8 type, u8 code, int *err)
923{
924 int fatal = 0;
925
926 *err = EPROTO;
927
928 switch (type) {
929 case ICMPV6_DEST_UNREACH:
930 fatal = 1;
931 if (code <= ICMPV6_PORT_UNREACH) {
932 *err = tab_unreach[code].err;
933 fatal = tab_unreach[code].fatal;
934 }
935 break;
936
937 case ICMPV6_PKT_TOOBIG:
938 *err = EMSGSIZE;
939 break;
940
941 case ICMPV6_PARAMPROB:
942 *err = EPROTO;
943 fatal = 1;
944 break;
945
946 case ICMPV6_TIME_EXCEED:
947 *err = EHOSTUNREACH;
948 break;
949 }
950
951 return fatal;
952}
953
954EXPORT_SYMBOL(icmpv6_err_convert);
955
956#ifdef CONFIG_SYSCTL
957ctl_table ipv6_icmp_table_template[] = {
958 {
959 .procname = "ratelimit",
960 .data = &init_net.ipv6.sysctl.icmpv6_time,
961 .maxlen = sizeof(int),
962 .mode = 0644,
963 .proc_handler = proc_dointvec_ms_jiffies,
964 },
965 { },
966};
967
968struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
969{
970 struct ctl_table *table;
971
972 table = kmemdup(ipv6_icmp_table_template,
973 sizeof(ipv6_icmp_table_template),
974 GFP_KERNEL);
975
976 if (table)
977 table[0].data = &net->ipv6.sysctl.icmpv6_time;
978
979 return table;
980}
981#endif
982