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gpio: rcar: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / net / ipv6 / icmp.c
blob2688f3e8216528a116f90f00d433a331ee0ae983
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Internet Control Message Protocol (ICMPv6)
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on net/ipv4/icmp.c
10 *
11 * RFC 1885
12 */
13
14 /*
15 * Changes:
16 *
17 * Andi Kleen : exception handling
18 * Andi Kleen add rate limits. never reply to a icmp.
19 * add more length checks and other fixes.
20 * yoshfuji : ensure to sent parameter problem for
21 * fragments.
22 * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit.
23 * Randy Dunlap and
24 * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support
25 * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data
26 */
27
28 #define pr_fmt(fmt) "IPv6: " fmt
29
30 #include <linux/module.h>
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/socket.h>
34 #include <linux/in.h>
35 #include <linux/kernel.h>
36 #include <linux/sockios.h>
37 #include <linux/net.h>
38 #include <linux/skbuff.h>
39 #include <linux/init.h>
40 #include <linux/netfilter.h>
41 #include <linux/slab.h>
42
43 #ifdef CONFIG_SYSCTL
44 #include <linux/sysctl.h>
45 #endif
46
47 #include <linux/inet.h>
48 #include <linux/netdevice.h>
49 #include <linux/icmpv6.h>
50
51 #include <net/ip.h>
52 #include <net/sock.h>
53
54 #include <net/ipv6.h>
55 #include <net/ip6_checksum.h>
56 #include <net/ping.h>
57 #include <net/protocol.h>
58 #include <net/raw.h>
59 #include <net/rawv6.h>
60 #include <net/transp_v6.h>
61 #include <net/ip6_route.h>
62 #include <net/addrconf.h>
63 #include <net/icmp.h>
64 #include <net/xfrm.h>
65 #include <net/inet_common.h>
66 #include <net/dsfield.h>
67 #include <net/l3mdev.h>
68
69 #include <linux/uaccess.h>
70
71 /*
72 * The ICMP socket(s). This is the most convenient way to flow control
73 * our ICMP output as well as maintain a clean interface throughout
74 * all layers. All Socketless IP sends will soon be gone.
75 *
76 * On SMP we have one ICMP socket per-cpu.
77 */
78 static struct sock *icmpv6_sk(struct net *net)
79 {
80 return this_cpu_read(*net->ipv6.icmp_sk);
81 }
82
83 static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
84 u8 type, u8 code, int offset, __be32 info)
85 {
86 /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
87 struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
88 struct net *net = dev_net(skb->dev);
89
90 if (type == ICMPV6_PKT_TOOBIG)
91 ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
92 else if (type == NDISC_REDIRECT)
93 ip6_redirect(skb, net, skb->dev->ifindex, 0,
94 sock_net_uid(net, NULL));
95
96 if (!(type & ICMPV6_INFOMSG_MASK))
97 if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
98 ping_err(skb, offset, ntohl(info));
99
100 return 0;
101 }
102
103 static int icmpv6_rcv(struct sk_buff *skb);
104
105 static const struct inet6_protocol icmpv6_protocol = {
106 .handler = icmpv6_rcv,
107 .err_handler = icmpv6_err,
108 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
109 };
110
111 /* Called with BH disabled */
112 static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
113 {
114 struct sock *sk;
115
116 sk = icmpv6_sk(net);
117 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
118 /* This can happen if the output path (f.e. SIT or
119 * ip6ip6 tunnel) signals dst_link_failure() for an
120 * outgoing ICMP6 packet.
121 */
122 return NULL;
123 }
124 return sk;
125 }
126
127 static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
128 {
129 spin_unlock(&sk->sk_lock.slock);
130 }
131
132 /*
133 * Figure out, may we reply to this packet with icmp error.
134 *
135 * We do not reply, if:
136 * - it was icmp error message.
137 * - it is truncated, so that it is known, that protocol is ICMPV6
138 * (i.e. in the middle of some exthdr)
139 *
140 * --ANK (980726)
141 */
142
143 static bool is_ineligible(const struct sk_buff *skb)
144 {
145 int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
146 int len = skb->len - ptr;
147 __u8 nexthdr = ipv6_hdr(skb)->nexthdr;
148 __be16 frag_off;
149
150 if (len < 0)
151 return true;
152
153 ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
154 if (ptr < 0)
155 return false;
156 if (nexthdr == IPPROTO_ICMPV6) {
157 u8 _type, *tp;
158 tp = skb_header_pointer(skb,
159 ptr+offsetof(struct icmp6hdr, icmp6_type),
160 sizeof(_type), &_type);
161 if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
162 return true;
163 }
164 return false;
165 }
166
167 static bool icmpv6_mask_allow(struct net *net, int type)
168 {
169 if (type > ICMPV6_MSG_MAX)
170 return true;
171
172 /* Limit if icmp type is set in ratemask. */
173 if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
174 return true;
175
176 return false;
177 }
178
179 static bool icmpv6_global_allow(struct net *net, int type)
180 {
181 if (icmpv6_mask_allow(net, type))
182 return true;
183
184 if (icmp_global_allow())
185 return true;
186
187 return false;
188 }
189
190 /*
191 * Check the ICMP output rate limit
192 */
193 static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
194 struct flowi6 *fl6)
195 {
196 struct net *net = sock_net(sk);
197 struct dst_entry *dst;
198 bool res = false;
199
200 if (icmpv6_mask_allow(net, type))
201 return true;
202
203 /*
204 * Look up the output route.
205 * XXX: perhaps the expire for routing entries cloned by
206 * this lookup should be more aggressive (not longer than timeout).
207 */
208 dst = ip6_route_output(net, sk, fl6);
209 if (dst->error) {
210 IP6_INC_STATS(net, ip6_dst_idev(dst),
211 IPSTATS_MIB_OUTNOROUTES);
212 } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
213 res = true;
214 } else {
215 struct rt6_info *rt = (struct rt6_info *)dst;
216 int tmo = net->ipv6.sysctl.icmpv6_time;
217 struct inet_peer *peer;
218
219 /* Give more bandwidth to wider prefixes. */
220 if (rt->rt6i_dst.plen < 128)
221 tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
222
223 peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
224 res = inet_peer_xrlim_allow(peer, tmo);
225 if (peer)
226 inet_putpeer(peer);
227 }
228 dst_release(dst);
229 return res;
230 }
231
232 /*
233 * an inline helper for the "simple" if statement below
234 * checks if parameter problem report is caused by an
235 * unrecognized IPv6 option that has the Option Type
236 * highest-order two bits set to 10
237 */
238
239 static bool opt_unrec(struct sk_buff *skb, __u32 offset)
240 {
241 u8 _optval, *op;
242
243 offset += skb_network_offset(skb);
244 op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
245 if (!op)
246 return true;
247 return (*op & 0xC0) == 0x80;
248 }
249
250 void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
251 struct icmp6hdr *thdr, int len)
252 {
253 struct sk_buff *skb;
254 struct icmp6hdr *icmp6h;
255
256 skb = skb_peek(&sk->sk_write_queue);
257 if (!skb)
258 return;
259
260 icmp6h = icmp6_hdr(skb);
261 memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
262 icmp6h->icmp6_cksum = 0;
263
264 if (skb_queue_len(&sk->sk_write_queue) == 1) {
265 skb->csum = csum_partial(icmp6h,
266 sizeof(struct icmp6hdr), skb->csum);
267 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
268 &fl6->daddr,
269 len, fl6->flowi6_proto,
270 skb->csum);
271 } else {
272 __wsum tmp_csum = 0;
273
274 skb_queue_walk(&sk->sk_write_queue, skb) {
275 tmp_csum = csum_add(tmp_csum, skb->csum);
276 }
277
278 tmp_csum = csum_partial(icmp6h,
279 sizeof(struct icmp6hdr), tmp_csum);
280 icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
281 &fl6->daddr,
282 len, fl6->flowi6_proto,
283 tmp_csum);
284 }
285 ip6_push_pending_frames(sk);
286 }
287
288 struct icmpv6_msg {
289 struct sk_buff *skb;
290 int offset;
291 uint8_t type;
292 };
293
294 static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
295 {
296 struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
297 struct sk_buff *org_skb = msg->skb;
298 __wsum csum = 0;
299
300 csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
301 to, len, csum);
302 skb->csum = csum_block_add(skb->csum, csum, odd);
303 if (!(msg->type & ICMPV6_INFOMSG_MASK))
304 nf_ct_attach(skb, org_skb);
305 return 0;
306 }
307
308 #if IS_ENABLED(CONFIG_IPV6_MIP6)
309 static void mip6_addr_swap(struct sk_buff *skb)
310 {
311 struct ipv6hdr *iph = ipv6_hdr(skb);
312 struct inet6_skb_parm *opt = IP6CB(skb);
313 struct ipv6_destopt_hao *hao;
314 struct in6_addr tmp;
315 int off;
316
317 if (opt->dsthao) {
318 off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
319 if (likely(off >= 0)) {
320 hao = (struct ipv6_destopt_hao *)
321 (skb_network_header(skb) + off);
322 tmp = iph->saddr;
323 iph->saddr = hao->addr;
324 hao->addr = tmp;
325 }
326 }
327 }
328 #else
329 static inline void mip6_addr_swap(struct sk_buff *skb) {}
330 #endif
331
332 static struct dst_entry *icmpv6_route_lookup(struct net *net,
333 struct sk_buff *skb,
334 struct sock *sk,
335 struct flowi6 *fl6)
336 {
337 struct dst_entry *dst, *dst2;
338 struct flowi6 fl2;
339 int err;
340
341 err = ip6_dst_lookup(net, sk, &dst, fl6);
342 if (err)
343 return ERR_PTR(err);
344
345 /*
346 * We won't send icmp if the destination is known
347 * anycast.
348 */
349 if (ipv6_anycast_destination(dst, &fl6->daddr)) {
350 net_dbg_ratelimited("icmp6_send: acast source\n");
351 dst_release(dst);
352 return ERR_PTR(-EINVAL);
353 }
354
355 /* No need to clone since we're just using its address. */
356 dst2 = dst;
357
358 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
359 if (!IS_ERR(dst)) {
360 if (dst != dst2)
361 return dst;
362 } else {
363 if (PTR_ERR(dst) == -EPERM)
364 dst = NULL;
365 else
366 return dst;
367 }
368
369 err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
370 if (err)
371 goto relookup_failed;
372
373 err = ip6_dst_lookup(net, sk, &dst2, &fl2);
374 if (err)
375 goto relookup_failed;
376
377 dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
378 if (!IS_ERR(dst2)) {
379 dst_release(dst);
380 dst = dst2;
381 } else {
382 err = PTR_ERR(dst2);
383 if (err == -EPERM) {
384 dst_release(dst);
385 return dst2;
386 } else
387 goto relookup_failed;
388 }
389
390 relookup_failed:
391 if (dst)
392 return dst;
393 return ERR_PTR(err);
394 }
395
396 static struct net_device *icmp6_dev(const struct sk_buff *skb)
397 {
398 struct net_device *dev = skb->dev;
399
400 /* for local traffic to local address, skb dev is the loopback
401 * device. Check if there is a dst attached to the skb and if so
402 * get the real device index. Same is needed for replies to a link
403 * local address on a device enslaved to an L3 master device
404 */
405 if (unlikely(dev->ifindex == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) {
406 const struct rt6_info *rt6 = skb_rt6_info(skb);
407
408 if (rt6)
409 dev = rt6->rt6i_idev->dev;
410 }
411
412 return dev;
413 }
414
415 static int icmp6_iif(const struct sk_buff *skb)
416 {
417 return icmp6_dev(skb)->ifindex;
418 }
419
420 /*
421 * Send an ICMP message in response to a packet in error
422 */
423 static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
424 const struct in6_addr *force_saddr)
425 {
426 struct inet6_dev *idev = NULL;
427 struct ipv6hdr *hdr = ipv6_hdr(skb);
428 struct sock *sk;
429 struct net *net;
430 struct ipv6_pinfo *np;
431 const struct in6_addr *saddr = NULL;
432 struct dst_entry *dst;
433 struct icmp6hdr tmp_hdr;
434 struct flowi6 fl6;
435 struct icmpv6_msg msg;
436 struct ipcm6_cookie ipc6;
437 int iif = 0;
438 int addr_type = 0;
439 int len;
440 u32 mark;
441
442 if ((u8 *)hdr < skb->head ||
443 (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
444 return;
445
446 if (!skb->dev)
447 return;
448 net = dev_net(skb->dev);
449 mark = IP6_REPLY_MARK(net, skb->mark);
450 /*
451 * Make sure we respect the rules
452 * i.e. RFC 1885 2.4(e)
453 * Rule (e.1) is enforced by not using icmp6_send
454 * in any code that processes icmp errors.
455 */
456 addr_type = ipv6_addr_type(&hdr->daddr);
457
458 if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
459 ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
460 saddr = &hdr->daddr;
461
462 /*
463 * Dest addr check
464 */
465
466 if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
467 if (type != ICMPV6_PKT_TOOBIG &&
468 !(type == ICMPV6_PARAMPROB &&
469 code == ICMPV6_UNK_OPTION &&
470 (opt_unrec(skb, info))))
471 return;
472
473 saddr = NULL;
474 }
475
476 addr_type = ipv6_addr_type(&hdr->saddr);
477
478 /*
479 * Source addr check
480 */
481
482 if (__ipv6_addr_needs_scope_id(addr_type)) {
483 iif = icmp6_iif(skb);
484 } else {
485 dst = skb_dst(skb);
486 iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
487 }
488
489 /*
490 * Must not send error if the source does not uniquely
491 * identify a single node (RFC2463 Section 2.4).
492 * We check unspecified / multicast addresses here,
493 * and anycast addresses will be checked later.
494 */
495 if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
496 net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
497 &hdr->saddr, &hdr->daddr);
498 return;
499 }
500
501 /*
502 * Never answer to a ICMP packet.
503 */
504 if (is_ineligible(skb)) {
505 net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
506 &hdr->saddr, &hdr->daddr);
507 return;
508 }
509
510 /* Needed by both icmp_global_allow and icmpv6_xmit_lock */
511 local_bh_disable();
512
513 /* Check global sysctl_icmp_msgs_per_sec ratelimit */
514 if (!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, type))
515 goto out_bh_enable;
516
517 mip6_addr_swap(skb);
518
519 sk = icmpv6_xmit_lock(net);
520 if (!sk)
521 goto out_bh_enable;
522
523 memset(&fl6, 0, sizeof(fl6));
524 fl6.flowi6_proto = IPPROTO_ICMPV6;
525 fl6.daddr = hdr->saddr;
526 if (force_saddr)
527 saddr = force_saddr;
528 if (saddr) {
529 fl6.saddr = *saddr;
530 } else {
531 /* select a more meaningful saddr from input if */
532 struct net_device *in_netdev;
533
534 in_netdev = dev_get_by_index(net, IP6CB(skb)->iif);
535 if (in_netdev) {
536 ipv6_dev_get_saddr(net, in_netdev, &fl6.daddr,
537 inet6_sk(sk)->srcprefs,
538 &fl6.saddr);
539 dev_put(in_netdev);
540 }
541 }
542 fl6.flowi6_mark = mark;
543 fl6.flowi6_oif = iif;
544 fl6.fl6_icmp_type = type;
545 fl6.fl6_icmp_code = code;
546 fl6.flowi6_uid = sock_net_uid(net, NULL);
547 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
548 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
549
550 sk->sk_mark = mark;
551 np = inet6_sk(sk);
552
553 if (!icmpv6_xrlim_allow(sk, type, &fl6))
554 goto out;
555
556 tmp_hdr.icmp6_type = type;
557 tmp_hdr.icmp6_code = code;
558 tmp_hdr.icmp6_cksum = 0;
559 tmp_hdr.icmp6_pointer = htonl(info);
560
561 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
562 fl6.flowi6_oif = np->mcast_oif;
563 else if (!fl6.flowi6_oif)
564 fl6.flowi6_oif = np->ucast_oif;
565
566 ipcm6_init_sk(&ipc6, np);
567 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
568
569 dst = icmpv6_route_lookup(net, skb, sk, &fl6);
570 if (IS_ERR(dst))
571 goto out;
572
573 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
574
575 msg.skb = skb;
576 msg.offset = skb_network_offset(skb);
577 msg.type = type;
578
579 len = skb->len - msg.offset;
580 len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
581 if (len < 0) {
582 net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
583 &hdr->saddr, &hdr->daddr);
584 goto out_dst_release;
585 }
586
587 rcu_read_lock();
588 idev = __in6_dev_get(skb->dev);
589
590 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
591 len + sizeof(struct icmp6hdr),
592 sizeof(struct icmp6hdr),
593 &ipc6, &fl6, (struct rt6_info *)dst,
594 MSG_DONTWAIT)) {
595 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
596 ip6_flush_pending_frames(sk);
597 } else {
598 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
599 len + sizeof(struct icmp6hdr));
600 }
601 rcu_read_unlock();
602 out_dst_release:
603 dst_release(dst);
604 out:
605 icmpv6_xmit_unlock(sk);
606 out_bh_enable:
607 local_bh_enable();
608 }
609
610 /* Slightly more convenient version of icmp6_send.
611 */
612 void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
613 {
614 icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
615 kfree_skb(skb);
616 }
617
618 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
619 * if sufficient data bytes are available
620 * @nhs is the size of the tunnel header(s) :
621 * Either an IPv4 header for SIT encap
622 * an IPv4 header + GRE header for GRE encap
623 */
624 int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
625 unsigned int data_len)
626 {
627 struct in6_addr temp_saddr;
628 struct rt6_info *rt;
629 struct sk_buff *skb2;
630 u32 info = 0;
631
632 if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
633 return 1;
634
635 /* RFC 4884 (partial) support for ICMP extensions */
636 if (data_len < 128 || (data_len & 7) || skb->len < data_len)
637 data_len = 0;
638
639 skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
640
641 if (!skb2)
642 return 1;
643
644 skb_dst_drop(skb2);
645 skb_pull(skb2, nhs);
646 skb_reset_network_header(skb2);
647
648 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
649 skb, 0);
650
651 if (rt && rt->dst.dev)
652 skb2->dev = rt->dst.dev;
653
654 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
655
656 if (data_len) {
657 /* RFC 4884 (partial) support :
658 * insert 0 padding at the end, before the extensions
659 */
660 __skb_push(skb2, nhs);
661 skb_reset_network_header(skb2);
662 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
663 memset(skb2->data + data_len - nhs, 0, nhs);
664 /* RFC 4884 4.5 : Length is measured in 64-bit words,
665 * and stored in reserved[0]
666 */
667 info = (data_len/8) << 24;
668 }
669 if (type == ICMP_TIME_EXCEEDED)
670 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
671 info, &temp_saddr);
672 else
673 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
674 info, &temp_saddr);
675 if (rt)
676 ip6_rt_put(rt);
677
678 kfree_skb(skb2);
679
680 return 0;
681 }
682 EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
683
684 static void icmpv6_echo_reply(struct sk_buff *skb)
685 {
686 struct net *net = dev_net(skb->dev);
687 struct sock *sk;
688 struct inet6_dev *idev;
689 struct ipv6_pinfo *np;
690 const struct in6_addr *saddr = NULL;
691 struct icmp6hdr *icmph = icmp6_hdr(skb);
692 struct icmp6hdr tmp_hdr;
693 struct flowi6 fl6;
694 struct icmpv6_msg msg;
695 struct dst_entry *dst;
696 struct ipcm6_cookie ipc6;
697 u32 mark = IP6_REPLY_MARK(net, skb->mark);
698 bool acast;
699
700 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
701 net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
702 return;
703
704 saddr = &ipv6_hdr(skb)->daddr;
705
706 acast = ipv6_anycast_destination(skb_dst(skb), saddr);
707 if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
708 return;
709
710 if (!ipv6_unicast_destination(skb) &&
711 !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
712 saddr = NULL;
713
714 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
715 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
716
717 memset(&fl6, 0, sizeof(fl6));
718 if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
719 fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
720
721 fl6.flowi6_proto = IPPROTO_ICMPV6;
722 fl6.daddr = ipv6_hdr(skb)->saddr;
723 if (saddr)
724 fl6.saddr = *saddr;
725 fl6.flowi6_oif = icmp6_iif(skb);
726 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
727 fl6.flowi6_mark = mark;
728 fl6.flowi6_uid = sock_net_uid(net, NULL);
729 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
730
731 local_bh_disable();
732 sk = icmpv6_xmit_lock(net);
733 if (!sk)
734 goto out_bh_enable;
735 sk->sk_mark = mark;
736 np = inet6_sk(sk);
737
738 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
739 fl6.flowi6_oif = np->mcast_oif;
740 else if (!fl6.flowi6_oif)
741 fl6.flowi6_oif = np->ucast_oif;
742
743 if (ip6_dst_lookup(net, sk, &dst, &fl6))
744 goto out;
745 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
746 if (IS_ERR(dst))
747 goto out;
748
749 /* Check the ratelimit */
750 if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
751 !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
752 goto out_dst_release;
753
754 idev = __in6_dev_get(skb->dev);
755
756 msg.skb = skb;
757 msg.offset = 0;
758 msg.type = ICMPV6_ECHO_REPLY;
759
760 ipcm6_init_sk(&ipc6, np);
761 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
762 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
763
764 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
765 skb->len + sizeof(struct icmp6hdr),
766 sizeof(struct icmp6hdr), &ipc6, &fl6,
767 (struct rt6_info *)dst, MSG_DONTWAIT)) {
768 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
769 ip6_flush_pending_frames(sk);
770 } else {
771 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
772 skb->len + sizeof(struct icmp6hdr));
773 }
774 out_dst_release:
775 dst_release(dst);
776 out:
777 icmpv6_xmit_unlock(sk);
778 out_bh_enable:
779 local_bh_enable();
780 }
781
782 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
783 {
784 const struct inet6_protocol *ipprot;
785 int inner_offset;
786 __be16 frag_off;
787 u8 nexthdr;
788 struct net *net = dev_net(skb->dev);
789
790 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
791 goto out;
792
793 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
794 if (ipv6_ext_hdr(nexthdr)) {
795 /* now skip over extension headers */
796 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
797 &nexthdr, &frag_off);
798 if (inner_offset < 0)
799 goto out;
800 } else {
801 inner_offset = sizeof(struct ipv6hdr);
802 }
803
804 /* Checkin header including 8 bytes of inner protocol header. */
805 if (!pskb_may_pull(skb, inner_offset+8))
806 goto out;
807
808 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
809 Without this we will not able f.e. to make source routed
810 pmtu discovery.
811 Corresponding argument (opt) to notifiers is already added.
812 --ANK (980726)
813 */
814
815 ipprot = rcu_dereference(inet6_protos[nexthdr]);
816 if (ipprot && ipprot->err_handler)
817 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
818
819 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
820 return;
821
822 out:
823 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
824 }
825
826 /*
827 * Handle icmp messages
828 */
829
830 static int icmpv6_rcv(struct sk_buff *skb)
831 {
832 struct net *net = dev_net(skb->dev);
833 struct net_device *dev = icmp6_dev(skb);
834 struct inet6_dev *idev = __in6_dev_get(dev);
835 const struct in6_addr *saddr, *daddr;
836 struct icmp6hdr *hdr;
837 u8 type;
838 bool success = false;
839
840 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
841 struct sec_path *sp = skb_sec_path(skb);
842 int nh;
843
844 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
845 XFRM_STATE_ICMP))
846 goto drop_no_count;
847
848 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
849 goto drop_no_count;
850
851 nh = skb_network_offset(skb);
852 skb_set_network_header(skb, sizeof(*hdr));
853
854 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
855 goto drop_no_count;
856
857 skb_set_network_header(skb, nh);
858 }
859
860 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
861
862 saddr = &ipv6_hdr(skb)->saddr;
863 daddr = &ipv6_hdr(skb)->daddr;
864
865 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
866 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
867 saddr, daddr);
868 goto csum_error;
869 }
870
871 if (!pskb_pull(skb, sizeof(*hdr)))
872 goto discard_it;
873
874 hdr = icmp6_hdr(skb);
875
876 type = hdr->icmp6_type;
877
878 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
879
880 switch (type) {
881 case ICMPV6_ECHO_REQUEST:
882 if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
883 icmpv6_echo_reply(skb);
884 break;
885
886 case ICMPV6_ECHO_REPLY:
887 success = ping_rcv(skb);
888 break;
889
890 case ICMPV6_PKT_TOOBIG:
891 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
892 standard destination cache. Seems, only "advanced"
893 destination cache will allow to solve this problem
894 --ANK (980726)
895 */
896 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
897 goto discard_it;
898 hdr = icmp6_hdr(skb);
899
900 /* to notify */
901 fallthrough;
902 case ICMPV6_DEST_UNREACH:
903 case ICMPV6_TIME_EXCEED:
904 case ICMPV6_PARAMPROB:
905 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
906 break;
907
908 case NDISC_ROUTER_SOLICITATION:
909 case NDISC_ROUTER_ADVERTISEMENT:
910 case NDISC_NEIGHBOUR_SOLICITATION:
911 case NDISC_NEIGHBOUR_ADVERTISEMENT:
912 case NDISC_REDIRECT:
913 ndisc_rcv(skb);
914 break;
915
916 case ICMPV6_MGM_QUERY:
917 igmp6_event_query(skb);
918 break;
919
920 case ICMPV6_MGM_REPORT:
921 igmp6_event_report(skb);
922 break;
923
924 case ICMPV6_MGM_REDUCTION:
925 case ICMPV6_NI_QUERY:
926 case ICMPV6_NI_REPLY:
927 case ICMPV6_MLD2_REPORT:
928 case ICMPV6_DHAAD_REQUEST:
929 case ICMPV6_DHAAD_REPLY:
930 case ICMPV6_MOBILE_PREFIX_SOL:
931 case ICMPV6_MOBILE_PREFIX_ADV:
932 break;
933
934 default:
935 /* informational */
936 if (type & ICMPV6_INFOMSG_MASK)
937 break;
938
939 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
940 saddr, daddr);
941
942 /*
943 * error of unknown type.
944 * must pass to upper level
945 */
946
947 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
948 }
949
950 /* until the v6 path can be better sorted assume failure and
951 * preserve the status quo behaviour for the rest of the paths to here
952 */
953 if (success)
954 consume_skb(skb);
955 else
956 kfree_skb(skb);
957
958 return 0;
959
960 csum_error:
961 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
962 discard_it:
963 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
964 drop_no_count:
965 kfree_skb(skb);
966 return 0;
967 }
968
969 void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
970 u8 type,
971 const struct in6_addr *saddr,
972 const struct in6_addr *daddr,
973 int oif)
974 {
975 memset(fl6, 0, sizeof(*fl6));
976 fl6->saddr = *saddr;
977 fl6->daddr = *daddr;
978 fl6->flowi6_proto = IPPROTO_ICMPV6;
979 fl6->fl6_icmp_type = type;
980 fl6->fl6_icmp_code = 0;
981 fl6->flowi6_oif = oif;
982 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
983 }
984
985 static void __net_exit icmpv6_sk_exit(struct net *net)
986 {
987 int i;
988
989 for_each_possible_cpu(i)
990 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv6.icmp_sk, i));
991 free_percpu(net->ipv6.icmp_sk);
992 }
993
994 static int __net_init icmpv6_sk_init(struct net *net)
995 {
996 struct sock *sk;
997 int err, i;
998
999 net->ipv6.icmp_sk = alloc_percpu(struct sock *);
1000 if (!net->ipv6.icmp_sk)
1001 return -ENOMEM;
1002
1003 for_each_possible_cpu(i) {
1004 err = inet_ctl_sock_create(&sk, PF_INET6,
1005 SOCK_RAW, IPPROTO_ICMPV6, net);
1006 if (err < 0) {
1007 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
1008 err);
1009 goto fail;
1010 }
1011
1012 *per_cpu_ptr(net->ipv6.icmp_sk, i) = sk;
1013
1014 /* Enough space for 2 64K ICMP packets, including
1015 * sk_buff struct overhead.
1016 */
1017 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1018 }
1019 return 0;
1020
1021 fail:
1022 icmpv6_sk_exit(net);
1023 return err;
1024 }
1025
1026 static struct pernet_operations icmpv6_sk_ops = {
1027 .init = icmpv6_sk_init,
1028 .exit = icmpv6_sk_exit,
1029 };
1030
1031 int __init icmpv6_init(void)
1032 {
1033 int err;
1034
1035 err = register_pernet_subsys(&icmpv6_sk_ops);
1036 if (err < 0)
1037 return err;
1038
1039 err = -EAGAIN;
1040 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1041 goto fail;
1042
1043 err = inet6_register_icmp_sender(icmp6_send);
1044 if (err)
1045 goto sender_reg_err;
1046 return 0;
1047
1048 sender_reg_err:
1049 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1050 fail:
1051 pr_err("Failed to register ICMP6 protocol\n");
1052 unregister_pernet_subsys(&icmpv6_sk_ops);
1053 return err;
1054 }
1055
1056 void icmpv6_cleanup(void)
1057 {
1058 inet6_unregister_icmp_sender(icmp6_send);
1059 unregister_pernet_subsys(&icmpv6_sk_ops);
1060 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1061 }
1062
1063
1064 static const struct icmp6_err {
1065 int err;
1066 int fatal;
1067 } tab_unreach[] = {
1068 { /* NOROUTE */
1069 .err = ENETUNREACH,
1070 .fatal = 0,
1071 },
1072 { /* ADM_PROHIBITED */
1073 .err = EACCES,
1074 .fatal = 1,
1075 },
1076 { /* Was NOT_NEIGHBOUR, now reserved */
1077 .err = EHOSTUNREACH,
1078 .fatal = 0,
1079 },
1080 { /* ADDR_UNREACH */
1081 .err = EHOSTUNREACH,
1082 .fatal = 0,
1083 },
1084 { /* PORT_UNREACH */
1085 .err = ECONNREFUSED,
1086 .fatal = 1,
1087 },
1088 { /* POLICY_FAIL */
1089 .err = EACCES,
1090 .fatal = 1,
1091 },
1092 { /* REJECT_ROUTE */
1093 .err = EACCES,
1094 .fatal = 1,
1095 },
1096 };
1097
1098 int icmpv6_err_convert(u8 type, u8 code, int *err)
1099 {
1100 int fatal = 0;
1101
1102 *err = EPROTO;
1103
1104 switch (type) {
1105 case ICMPV6_DEST_UNREACH:
1106 fatal = 1;
1107 if (code < ARRAY_SIZE(tab_unreach)) {
1108 *err = tab_unreach[code].err;
1109 fatal = tab_unreach[code].fatal;
1110 }
1111 break;
1112
1113 case ICMPV6_PKT_TOOBIG:
1114 *err = EMSGSIZE;
1115 break;
1116
1117 case ICMPV6_PARAMPROB:
1118 *err = EPROTO;
1119 fatal = 1;
1120 break;
1121
1122 case ICMPV6_TIME_EXCEED:
1123 *err = EHOSTUNREACH;
1124 break;
1125 }
1126
1127 return fatal;
1128 }
1129 EXPORT_SYMBOL(icmpv6_err_convert);
1130
1131 #ifdef CONFIG_SYSCTL
1132 static struct ctl_table ipv6_icmp_table_template[] = {
1133 {
1134 .procname = "ratelimit",
1135 .data = &init_net.ipv6.sysctl.icmpv6_time,
1136 .maxlen = sizeof(int),
1137 .mode = 0644,
1138 .proc_handler = proc_dointvec_ms_jiffies,
1139 },
1140 {
1141 .procname = "echo_ignore_all",
1142 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1143 .maxlen = sizeof(int),
1144 .mode = 0644,
1145 .proc_handler = proc_dointvec,
1146 },
1147 {
1148 .procname = "echo_ignore_multicast",
1149 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1150 .maxlen = sizeof(int),
1151 .mode = 0644,
1152 .proc_handler = proc_dointvec,
1153 },
1154 {
1155 .procname = "echo_ignore_anycast",
1156 .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1157 .maxlen = sizeof(int),
1158 .mode = 0644,
1159 .proc_handler = proc_dointvec,
1160 },
1161 {
1162 .procname = "ratemask",
1163 .data = &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1164 .maxlen = ICMPV6_MSG_MAX + 1,
1165 .mode = 0644,
1166 .proc_handler = proc_do_large_bitmap,
1167 },
1168 { },
1169 };
1170
1171 struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1172 {
1173 struct ctl_table *table;
1174
1175 table = kmemdup(ipv6_icmp_table_template,
1176 sizeof(ipv6_icmp_table_template),
1177 GFP_KERNEL);
1178
1179 if (table) {
1180 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1181 table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1182 table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1183 table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1184 table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1185 }
1186 return table;
1187 }
1188 #endif
Linux with added FPC-III support