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mlxsw: spectrum: Add support for getting kvdl occupancy
[linux-2.6/btrfs-unstable.git] / net / ipv6 / icmp.c
blob6ae5dd3f4d0de422ec36d4c25453f5841fd2a51e
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 */
82 static inline struct sock *icmpv6_sk(struct net *net)
83 {
84 return net->ipv6.icmp_sk[smp_processor_id()];
85 }
86
87 static 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
105 static int icmpv6_rcv(struct sk_buff *skb);
106
107 static 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 */
114 static __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
129 static __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
145 static 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
169 static 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
182 static 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 */
196 static 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
242 static 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
253 void 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
291 struct icmpv6_msg {
292 struct sk_buff *skb;
293 int offset;
294 uint8_t type;
295 };
296
297 static 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)
312 static 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
332 static inline void mip6_addr_swap(struct sk_buff *skb) {}
333 #endif
334
335 static 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
393 relookup_failed:
394 if (dst)
395 return dst;
396 return ERR_PTR(err);
397 }
398
399 static 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 */
420 static 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(&fl6, skb);
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();
586 out_dst_release:
587 dst_release(dst);
588 out:
589 icmpv6_xmit_unlock(sk);
590 out_bh_enable:
591 local_bh_enable();
592 }
593
594 /* Slightly more convenient version of icmp6_send.
595 */
596 void 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 */
608 int 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, 0);
633
634 if (rt && rt->dst.dev)
635 skb2->dev = rt->dst.dev;
636
637 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
638
639 if (data_len) {
640 /* RFC 4884 (partial) support :
641 * insert 0 padding at the end, before the extensions
642 */
643 __skb_push(skb2, nhs);
644 skb_reset_network_header(skb2);
645 memmove(skb2->data, skb2->data + nhs, data_len - nhs);
646 memset(skb2->data + data_len - nhs, 0, nhs);
647 /* RFC 4884 4.5 : Length is measured in 64-bit words,
648 * and stored in reserved[0]
649 */
650 info = (data_len/8) << 24;
651 }
652 if (type == ICMP_TIME_EXCEEDED)
653 icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
654 info, &temp_saddr);
655 else
656 icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
657 info, &temp_saddr);
658 if (rt)
659 ip6_rt_put(rt);
660
661 kfree_skb(skb2);
662
663 return 0;
664 }
665 EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
666
667 static void icmpv6_echo_reply(struct sk_buff *skb)
668 {
669 struct net *net = dev_net(skb->dev);
670 struct sock *sk;
671 struct inet6_dev *idev;
672 struct ipv6_pinfo *np;
673 const struct in6_addr *saddr = NULL;
674 struct icmp6hdr *icmph = icmp6_hdr(skb);
675 struct icmp6hdr tmp_hdr;
676 struct flowi6 fl6;
677 struct icmpv6_msg msg;
678 struct dst_entry *dst;
679 struct ipcm6_cookie ipc6;
680 u32 mark = IP6_REPLY_MARK(net, skb->mark);
681 struct sockcm_cookie sockc_unused = {0};
682
683 saddr = &ipv6_hdr(skb)->daddr;
684
685 if (!ipv6_unicast_destination(skb) &&
686 !(net->ipv6.sysctl.anycast_src_echo_reply &&
687 ipv6_anycast_destination(skb_dst(skb), saddr)))
688 saddr = NULL;
689
690 memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
691 tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
692
693 memset(&fl6, 0, sizeof(fl6));
694 fl6.flowi6_proto = IPPROTO_ICMPV6;
695 fl6.daddr = ipv6_hdr(skb)->saddr;
696 if (saddr)
697 fl6.saddr = *saddr;
698 fl6.flowi6_oif = icmp6_iif(skb);
699 fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
700 fl6.flowi6_mark = mark;
701 fl6.flowi6_uid = sock_net_uid(net, NULL);
702 security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
703
704 local_bh_disable();
705 sk = icmpv6_xmit_lock(net);
706 if (!sk)
707 goto out_bh_enable;
708 sk->sk_mark = mark;
709 np = inet6_sk(sk);
710
711 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
712 fl6.flowi6_oif = np->mcast_oif;
713 else if (!fl6.flowi6_oif)
714 fl6.flowi6_oif = np->ucast_oif;
715
716 if (ip6_dst_lookup(net, sk, &dst, &fl6))
717 goto out;
718 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
719 if (IS_ERR(dst))
720 goto out;
721
722 idev = __in6_dev_get(skb->dev);
723
724 msg.skb = skb;
725 msg.offset = 0;
726 msg.type = ICMPV6_ECHO_REPLY;
727
728 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
729 ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
730 ipc6.dontfrag = np->dontfrag;
731 ipc6.opt = NULL;
732
733 if (ip6_append_data(sk, icmpv6_getfrag, &msg,
734 skb->len + sizeof(struct icmp6hdr),
735 sizeof(struct icmp6hdr), &ipc6, &fl6,
736 (struct rt6_info *)dst, MSG_DONTWAIT,
737 &sockc_unused)) {
738 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
739 ip6_flush_pending_frames(sk);
740 } else {
741 icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
742 skb->len + sizeof(struct icmp6hdr));
743 }
744 dst_release(dst);
745 out:
746 icmpv6_xmit_unlock(sk);
747 out_bh_enable:
748 local_bh_enable();
749 }
750
751 void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
752 {
753 const struct inet6_protocol *ipprot;
754 int inner_offset;
755 __be16 frag_off;
756 u8 nexthdr;
757 struct net *net = dev_net(skb->dev);
758
759 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
760 goto out;
761
762 nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
763 if (ipv6_ext_hdr(nexthdr)) {
764 /* now skip over extension headers */
765 inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
766 &nexthdr, &frag_off);
767 if (inner_offset < 0)
768 goto out;
769 } else {
770 inner_offset = sizeof(struct ipv6hdr);
771 }
772
773 /* Checkin header including 8 bytes of inner protocol header. */
774 if (!pskb_may_pull(skb, inner_offset+8))
775 goto out;
776
777 /* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
778 Without this we will not able f.e. to make source routed
779 pmtu discovery.
780 Corresponding argument (opt) to notifiers is already added.
781 --ANK (980726)
782 */
783
784 ipprot = rcu_dereference(inet6_protos[nexthdr]);
785 if (ipprot && ipprot->err_handler)
786 ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
787
788 raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
789 return;
790
791 out:
792 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
793 }
794
795 /*
796 * Handle icmp messages
797 */
798
799 static int icmpv6_rcv(struct sk_buff *skb)
800 {
801 struct net_device *dev = skb->dev;
802 struct inet6_dev *idev = __in6_dev_get(dev);
803 const struct in6_addr *saddr, *daddr;
804 struct icmp6hdr *hdr;
805 u8 type;
806 bool success = false;
807
808 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
809 struct sec_path *sp = skb_sec_path(skb);
810 int nh;
811
812 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
813 XFRM_STATE_ICMP))
814 goto drop_no_count;
815
816 if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
817 goto drop_no_count;
818
819 nh = skb_network_offset(skb);
820 skb_set_network_header(skb, sizeof(*hdr));
821
822 if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
823 goto drop_no_count;
824
825 skb_set_network_header(skb, nh);
826 }
827
828 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
829
830 saddr = &ipv6_hdr(skb)->saddr;
831 daddr = &ipv6_hdr(skb)->daddr;
832
833 if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
834 net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
835 saddr, daddr);
836 goto csum_error;
837 }
838
839 if (!pskb_pull(skb, sizeof(*hdr)))
840 goto discard_it;
841
842 hdr = icmp6_hdr(skb);
843
844 type = hdr->icmp6_type;
845
846 ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
847
848 switch (type) {
849 case ICMPV6_ECHO_REQUEST:
850 icmpv6_echo_reply(skb);
851 break;
852
853 case ICMPV6_ECHO_REPLY:
854 success = ping_rcv(skb);
855 break;
856
857 case ICMPV6_PKT_TOOBIG:
858 /* BUGGG_FUTURE: if packet contains rthdr, we cannot update
859 standard destination cache. Seems, only "advanced"
860 destination cache will allow to solve this problem
861 --ANK (980726)
862 */
863 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
864 goto discard_it;
865 hdr = icmp6_hdr(skb);
866
867 /* to notify */
868 /* fall through */
869 case ICMPV6_DEST_UNREACH:
870 case ICMPV6_TIME_EXCEED:
871 case ICMPV6_PARAMPROB:
872 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
873 break;
874
875 case NDISC_ROUTER_SOLICITATION:
876 case NDISC_ROUTER_ADVERTISEMENT:
877 case NDISC_NEIGHBOUR_SOLICITATION:
878 case NDISC_NEIGHBOUR_ADVERTISEMENT:
879 case NDISC_REDIRECT:
880 ndisc_rcv(skb);
881 break;
882
883 case ICMPV6_MGM_QUERY:
884 igmp6_event_query(skb);
885 break;
886
887 case ICMPV6_MGM_REPORT:
888 igmp6_event_report(skb);
889 break;
890
891 case ICMPV6_MGM_REDUCTION:
892 case ICMPV6_NI_QUERY:
893 case ICMPV6_NI_REPLY:
894 case ICMPV6_MLD2_REPORT:
895 case ICMPV6_DHAAD_REQUEST:
896 case ICMPV6_DHAAD_REPLY:
897 case ICMPV6_MOBILE_PREFIX_SOL:
898 case ICMPV6_MOBILE_PREFIX_ADV:
899 break;
900
901 default:
902 /* informational */
903 if (type & ICMPV6_INFOMSG_MASK)
904 break;
905
906 net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
907 saddr, daddr);
908
909 /*
910 * error of unknown type.
911 * must pass to upper level
912 */
913
914 icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
915 }
916
917 /* until the v6 path can be better sorted assume failure and
918 * preserve the status quo behaviour for the rest of the paths to here
919 */
920 if (success)
921 consume_skb(skb);
922 else
923 kfree_skb(skb);
924
925 return 0;
926
927 csum_error:
928 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
929 discard_it:
930 __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
931 drop_no_count:
932 kfree_skb(skb);
933 return 0;
934 }
935
936 void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
937 u8 type,
938 const struct in6_addr *saddr,
939 const struct in6_addr *daddr,
940 int oif)
941 {
942 memset(fl6, 0, sizeof(*fl6));
943 fl6->saddr = *saddr;
944 fl6->daddr = *daddr;
945 fl6->flowi6_proto = IPPROTO_ICMPV6;
946 fl6->fl6_icmp_type = type;
947 fl6->fl6_icmp_code = 0;
948 fl6->flowi6_oif = oif;
949 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
950 }
951
952 static int __net_init icmpv6_sk_init(struct net *net)
953 {
954 struct sock *sk;
955 int err, i, j;
956
957 net->ipv6.icmp_sk =
958 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
959 if (!net->ipv6.icmp_sk)
960 return -ENOMEM;
961
962 for_each_possible_cpu(i) {
963 err = inet_ctl_sock_create(&sk, PF_INET6,
964 SOCK_RAW, IPPROTO_ICMPV6, net);
965 if (err < 0) {
966 pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
967 err);
968 goto fail;
969 }
970
971 net->ipv6.icmp_sk[i] = sk;
972
973 /* Enough space for 2 64K ICMP packets, including
974 * sk_buff struct overhead.
975 */
976 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
977 }
978 return 0;
979
980 fail:
981 for (j = 0; j < i; j++)
982 inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
983 kfree(net->ipv6.icmp_sk);
984 return err;
985 }
986
987 static void __net_exit icmpv6_sk_exit(struct net *net)
988 {
989 int i;
990
991 for_each_possible_cpu(i) {
992 inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
993 }
994 kfree(net->ipv6.icmp_sk);
995 }
996
997 static struct pernet_operations icmpv6_sk_ops = {
998 .init = icmpv6_sk_init,
999 .exit = icmpv6_sk_exit,
1000 };
1001
1002 int __init icmpv6_init(void)
1003 {
1004 int err;
1005
1006 err = register_pernet_subsys(&icmpv6_sk_ops);
1007 if (err < 0)
1008 return err;
1009
1010 err = -EAGAIN;
1011 if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1012 goto fail;
1013
1014 err = inet6_register_icmp_sender(icmp6_send);
1015 if (err)
1016 goto sender_reg_err;
1017 return 0;
1018
1019 sender_reg_err:
1020 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1021 fail:
1022 pr_err("Failed to register ICMP6 protocol\n");
1023 unregister_pernet_subsys(&icmpv6_sk_ops);
1024 return err;
1025 }
1026
1027 void icmpv6_cleanup(void)
1028 {
1029 inet6_unregister_icmp_sender(icmp6_send);
1030 unregister_pernet_subsys(&icmpv6_sk_ops);
1031 inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1032 }
1033
1034
1035 static const struct icmp6_err {
1036 int err;
1037 int fatal;
1038 } tab_unreach[] = {
1039 { /* NOROUTE */
1040 .err = ENETUNREACH,
1041 .fatal = 0,
1042 },
1043 { /* ADM_PROHIBITED */
1044 .err = EACCES,
1045 .fatal = 1,
1046 },
1047 { /* Was NOT_NEIGHBOUR, now reserved */
1048 .err = EHOSTUNREACH,
1049 .fatal = 0,
1050 },
1051 { /* ADDR_UNREACH */
1052 .err = EHOSTUNREACH,
1053 .fatal = 0,
1054 },
1055 { /* PORT_UNREACH */
1056 .err = ECONNREFUSED,
1057 .fatal = 1,
1058 },
1059 { /* POLICY_FAIL */
1060 .err = EACCES,
1061 .fatal = 1,
1062 },
1063 { /* REJECT_ROUTE */
1064 .err = EACCES,
1065 .fatal = 1,
1066 },
1067 };
1068
1069 int icmpv6_err_convert(u8 type, u8 code, int *err)
1070 {
1071 int fatal = 0;
1072
1073 *err = EPROTO;
1074
1075 switch (type) {
1076 case ICMPV6_DEST_UNREACH:
1077 fatal = 1;
1078 if (code < ARRAY_SIZE(tab_unreach)) {
1079 *err = tab_unreach[code].err;
1080 fatal = tab_unreach[code].fatal;
1081 }
1082 break;
1083
1084 case ICMPV6_PKT_TOOBIG:
1085 *err = EMSGSIZE;
1086 break;
1087
1088 case ICMPV6_PARAMPROB:
1089 *err = EPROTO;
1090 fatal = 1;
1091 break;
1092
1093 case ICMPV6_TIME_EXCEED:
1094 *err = EHOSTUNREACH;
1095 break;
1096 }
1097
1098 return fatal;
1099 }
1100 EXPORT_SYMBOL(icmpv6_err_convert);
1101
1102 #ifdef CONFIG_SYSCTL
1103 static struct ctl_table ipv6_icmp_table_template[] = {
1104 {
1105 .procname = "ratelimit",
1106 .data = &init_net.ipv6.sysctl.icmpv6_time,
1107 .maxlen = sizeof(int),
1108 .mode = 0644,
1109 .proc_handler = proc_dointvec_ms_jiffies,
1110 },
1111 { },
1112 };
1113
1114 struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1115 {
1116 struct ctl_table *table;
1117
1118 table = kmemdup(ipv6_icmp_table_template,
1119 sizeof(ipv6_icmp_table_template),
1120 GFP_KERNEL);
1121
1122 if (table)
1123 table[0].data = &net->ipv6.sysctl.icmpv6_time;
1124
1125 return table;
1126 }
1127 #endif
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