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v3.1
 
  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
v5.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	Internet Control Message Protocol (ICMPv6)
   4 *	Linux INET6 implementation
   5 *
   6 *	Authors:
   7 *	Pedro Roque		<roque@di.fc.ul.pt>
   8 *
   9 *	Based on net/ipv4/icmp.c
  10 *
  11 *	RFC 1885
 
 
 
 
 
  12 */
  13
  14/*
  15 *	Changes:
  16 *
  17 *	Andi Kleen		:	exception handling
  18 *	Andi Kleen			add rate limits. never reply to a icmp.
  19 *					add more length checks and other fixes.
  20 *	yoshfuji		:	ensure to sent parameter problem for
  21 *					fragments.
  22 *	YOSHIFUJI Hideaki @USAGI:	added sysctl for icmp rate limit.
  23 *	Randy Dunlap and
  24 *	YOSHIFUJI Hideaki @USAGI:	Per-interface statistics support
  25 *	Kazunori MIYAZAWA @USAGI:       change output process to use ip6_append_data
  26 */
  27
  28#define pr_fmt(fmt) "IPv6: " fmt
  29
  30#include <linux/module.h>
  31#include <linux/errno.h>
  32#include <linux/types.h>
  33#include <linux/socket.h>
  34#include <linux/in.h>
  35#include <linux/kernel.h>
  36#include <linux/sockios.h>
  37#include <linux/net.h>
  38#include <linux/skbuff.h>
  39#include <linux/init.h>
  40#include <linux/netfilter.h>
  41#include <linux/slab.h>
  42
  43#ifdef CONFIG_SYSCTL
  44#include <linux/sysctl.h>
  45#endif
  46
  47#include <linux/inet.h>
  48#include <linux/netdevice.h>
  49#include <linux/icmpv6.h>
  50
  51#include <net/ip.h>
  52#include <net/sock.h>
  53
  54#include <net/ipv6.h>
  55#include <net/ip6_checksum.h>
  56#include <net/ping.h>
  57#include <net/protocol.h>
  58#include <net/raw.h>
  59#include <net/rawv6.h>
  60#include <net/transp_v6.h>
  61#include <net/ip6_route.h>
  62#include <net/addrconf.h>
  63#include <net/icmp.h>
  64#include <net/xfrm.h>
  65#include <net/inet_common.h>
  66#include <net/dsfield.h>
  67#include <net/l3mdev.h>
  68
  69#include <linux/uaccess.h>
 
  70
  71/*
  72 *	The ICMP socket(s). This is the most convenient way to flow control
  73 *	our ICMP output as well as maintain a clean interface throughout
  74 *	all layers. All Socketless IP sends will soon be gone.
  75 *
  76 *	On SMP we have one ICMP socket per-cpu.
  77 */
  78static struct sock *icmpv6_sk(struct net *net)
  79{
  80	return this_cpu_read(*net->ipv6.icmp_sk);
  81}
  82
  83static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
  84		       u8 type, u8 code, int offset, __be32 info)
  85{
  86	/* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
  87	struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
  88	struct net *net = dev_net(skb->dev);
  89
  90	if (type == ICMPV6_PKT_TOOBIG)
  91		ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL));
  92	else if (type == NDISC_REDIRECT)
  93		ip6_redirect(skb, net, skb->dev->ifindex, 0,
  94			     sock_net_uid(net, NULL));
  95
  96	if (!(type & ICMPV6_INFOMSG_MASK))
  97		if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
  98			ping_err(skb, offset, ntohl(info));
  99
 100	return 0;
 101}
 102
 103static int icmpv6_rcv(struct sk_buff *skb);
 104
 105static const struct inet6_protocol icmpv6_protocol = {
 106	.handler	=	icmpv6_rcv,
 107	.err_handler	=	icmpv6_err,
 108	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
 109};
 110
 111/* Called with BH disabled */
 112static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
 113{
 114	struct sock *sk;
 115
 
 
 116	sk = icmpv6_sk(net);
 117	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
 118		/* This can happen if the output path (f.e. SIT or
 119		 * ip6ip6 tunnel) signals dst_link_failure() for an
 120		 * outgoing ICMP6 packet.
 121		 */
 
 122		return NULL;
 123	}
 124	return sk;
 125}
 126
 127static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
 128{
 129	spin_unlock(&sk->sk_lock.slock);
 
 
 
 
 
 
 
 
 
 130}
 131
 132/*
 133 * Figure out, may we reply to this packet with icmp error.
 134 *
 135 * We do not reply, if:
 136 *	- it was icmp error message.
 137 *	- it is truncated, so that it is known, that protocol is ICMPV6
 138 *	  (i.e. in the middle of some exthdr)
 139 *
 140 *	--ANK (980726)
 141 */
 142
 143static bool is_ineligible(const struct sk_buff *skb)
 144{
 145	int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
 146	int len = skb->len - ptr;
 147	__u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 148	__be16 frag_off;
 149
 150	if (len < 0)
 151		return true;
 152
 153	ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
 154	if (ptr < 0)
 155		return false;
 156	if (nexthdr == IPPROTO_ICMPV6) {
 157		u8 _type, *tp;
 158		tp = skb_header_pointer(skb,
 159			ptr+offsetof(struct icmp6hdr, icmp6_type),
 160			sizeof(_type), &_type);
 161		if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
 162			return true;
 
 163	}
 164	return false;
 165}
 166
 167static bool icmpv6_mask_allow(struct net *net, int type)
 168{
 169	if (type > ICMPV6_MSG_MAX)
 170		return true;
 171
 172	/* Limit if icmp type is set in ratemask. */
 173	if (!test_bit(type, net->ipv6.sysctl.icmpv6_ratemask))
 174		return true;
 175
 176	return false;
 177}
 178
 179static bool icmpv6_global_allow(struct net *net, int type)
 180{
 181	if (icmpv6_mask_allow(net, type))
 182		return true;
 183
 184	if (icmp_global_allow())
 185		return true;
 186
 187	return false;
 188}
 189
 190/*
 191 * Check the ICMP output rate limit
 192 */
 193static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
 194			       struct flowi6 *fl6)
 195{
 
 196	struct net *net = sock_net(sk);
 197	struct dst_entry *dst;
 198	bool res = false;
 199
 200	if (icmpv6_mask_allow(net, type))
 
 
 
 
 
 201		return true;
 202
 203	/*
 204	 * Look up the output route.
 205	 * XXX: perhaps the expire for routing entries cloned by
 206	 * this lookup should be more aggressive (not longer than timeout).
 207	 */
 208	dst = ip6_route_output(net, sk, fl6);
 209	if (dst->error) {
 210		IP6_INC_STATS(net, ip6_dst_idev(dst),
 211			      IPSTATS_MIB_OUTNOROUTES);
 212	} else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
 213		res = true;
 214	} else {
 215		struct rt6_info *rt = (struct rt6_info *)dst;
 216		int tmo = net->ipv6.sysctl.icmpv6_time;
 217		struct inet_peer *peer;
 218
 219		/* Give more bandwidth to wider prefixes. */
 220		if (rt->rt6i_dst.plen < 128)
 221			tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
 222
 223		peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
 224		res = inet_peer_xrlim_allow(peer, tmo);
 225		if (peer)
 226			inet_putpeer(peer);
 227	}
 228	dst_release(dst);
 229	return res;
 230}
 231
 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
 239static 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
 250void 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
 288struct icmpv6_msg {
 289	struct sk_buff	*skb;
 290	int		offset;
 291	uint8_t		type;
 292};
 293
 294static 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)
 309static 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
 329static inline void mip6_addr_swap(struct sk_buff *skb) {}
 330#endif
 331
 332static 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
 390relookup_failed:
 391	if (dst)
 392		return dst;
 393	return ERR_PTR(err);
 394}
 395
 396static 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
 415static 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 */
 423static 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	memset(&fl6, 0, sizeof(fl6));
 520	fl6.flowi6_proto = IPPROTO_ICMPV6;
 521	fl6.daddr = hdr->saddr;
 522	if (force_saddr)
 523		saddr = force_saddr;
 524	if (saddr)
 525		fl6.saddr = *saddr;
 526	fl6.flowi6_mark = mark;
 527	fl6.flowi6_oif = iif;
 528	fl6.fl6_icmp_type = type;
 529	fl6.fl6_icmp_code = code;
 530	fl6.flowi6_uid = sock_net_uid(net, NULL);
 531	fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
 532	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 533
 534	sk = icmpv6_xmit_lock(net);
 535	if (!sk)
 536		goto out_bh_enable;
 537
 538	sk->sk_mark = mark;
 539	np = inet6_sk(sk);
 540
 541	if (!icmpv6_xrlim_allow(sk, type, &fl6))
 542		goto out;
 543
 544	tmp_hdr.icmp6_type = type;
 545	tmp_hdr.icmp6_code = code;
 546	tmp_hdr.icmp6_cksum = 0;
 547	tmp_hdr.icmp6_pointer = htonl(info);
 548
 549	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 550		fl6.flowi6_oif = np->mcast_oif;
 551	else if (!fl6.flowi6_oif)
 552		fl6.flowi6_oif = np->ucast_oif;
 553
 554	ipcm6_init_sk(&ipc6, np);
 555	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
 556
 557	dst = icmpv6_route_lookup(net, skb, sk, &fl6);
 558	if (IS_ERR(dst))
 559		goto out;
 560
 561	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 
 
 
 
 
 562
 563	msg.skb = skb;
 564	msg.offset = skb_network_offset(skb);
 565	msg.type = type;
 566
 567	len = skb->len - msg.offset;
 568	len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
 569	if (len < 0) {
 570		net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
 571				    &hdr->saddr, &hdr->daddr);
 572		goto out_dst_release;
 573	}
 574
 575	rcu_read_lock();
 576	idev = __in6_dev_get(skb->dev);
 577
 578	if (ip6_append_data(sk, icmpv6_getfrag, &msg,
 579			    len + sizeof(struct icmp6hdr),
 580			    sizeof(struct icmp6hdr),
 581			    &ipc6, &fl6, (struct rt6_info *)dst,
 582			    MSG_DONTWAIT)) {
 583		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
 
 584		ip6_flush_pending_frames(sk);
 585	} else {
 586		icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 587					   len + sizeof(struct icmp6hdr));
 588	}
 589	rcu_read_unlock();
 
 
 
 
 590out_dst_release:
 591	dst_release(dst);
 592out:
 593	icmpv6_xmit_unlock(sk);
 594out_bh_enable:
 595	local_bh_enable();
 596}
 597
 598/* Slightly more convenient version of icmp6_send.
 599 */
 600void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
 601{
 602	icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
 603	kfree_skb(skb);
 604}
 605
 606/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
 607 * if sufficient data bytes are available
 608 * @nhs is the size of the tunnel header(s) :
 609 *  Either an IPv4 header for SIT encap
 610 *         an IPv4 header + GRE header for GRE encap
 611 */
 612int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
 613			       unsigned int data_len)
 614{
 615	struct in6_addr temp_saddr;
 616	struct rt6_info *rt;
 617	struct sk_buff *skb2;
 618	u32 info = 0;
 619
 620	if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
 621		return 1;
 622
 623	/* RFC 4884 (partial) support for ICMP extensions */
 624	if (data_len < 128 || (data_len & 7) || skb->len < data_len)
 625		data_len = 0;
 626
 627	skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
 628
 629	if (!skb2)
 630		return 1;
 631
 632	skb_dst_drop(skb2);
 633	skb_pull(skb2, nhs);
 634	skb_reset_network_header(skb2);
 635
 636	rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
 637			skb, 0);
 638
 639	if (rt && rt->dst.dev)
 640		skb2->dev = rt->dst.dev;
 641
 642	ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
 643
 644	if (data_len) {
 645		/* RFC 4884 (partial) support :
 646		 * insert 0 padding at the end, before the extensions
 647		 */
 648		__skb_push(skb2, nhs);
 649		skb_reset_network_header(skb2);
 650		memmove(skb2->data, skb2->data + nhs, data_len - nhs);
 651		memset(skb2->data + data_len - nhs, 0, nhs);
 652		/* RFC 4884 4.5 : Length is measured in 64-bit words,
 653		 * and stored in reserved[0]
 654		 */
 655		info = (data_len/8) << 24;
 656	}
 657	if (type == ICMP_TIME_EXCEEDED)
 658		icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 659			   info, &temp_saddr);
 660	else
 661		icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
 662			   info, &temp_saddr);
 663	if (rt)
 664		ip6_rt_put(rt);
 665
 666	kfree_skb(skb2);
 667
 668	return 0;
 669}
 670EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
 671
 672static void icmpv6_echo_reply(struct sk_buff *skb)
 673{
 674	struct net *net = dev_net(skb->dev);
 675	struct sock *sk;
 676	struct inet6_dev *idev;
 677	struct ipv6_pinfo *np;
 678	const struct in6_addr *saddr = NULL;
 679	struct icmp6hdr *icmph = icmp6_hdr(skb);
 680	struct icmp6hdr tmp_hdr;
 681	struct flowi6 fl6;
 682	struct icmpv6_msg msg;
 683	struct dst_entry *dst;
 684	struct ipcm6_cookie ipc6;
 685	u32 mark = IP6_REPLY_MARK(net, skb->mark);
 686	bool acast;
 687
 688	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) &&
 689	    net->ipv6.sysctl.icmpv6_echo_ignore_multicast)
 690		return;
 691
 692	saddr = &ipv6_hdr(skb)->daddr;
 693
 694	acast = ipv6_anycast_destination(skb_dst(skb), saddr);
 695	if (acast && net->ipv6.sysctl.icmpv6_echo_ignore_anycast)
 696		return;
 697
 698	if (!ipv6_unicast_destination(skb) &&
 699	    !(net->ipv6.sysctl.anycast_src_echo_reply && acast))
 700		saddr = NULL;
 701
 702	memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
 703	tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
 704
 705	memset(&fl6, 0, sizeof(fl6));
 706	if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_ICMPV6_ECHO_REPLIES)
 707		fl6.flowlabel = ip6_flowlabel(ipv6_hdr(skb));
 708
 709	fl6.flowi6_proto = IPPROTO_ICMPV6;
 710	fl6.daddr = ipv6_hdr(skb)->saddr;
 711	if (saddr)
 712		fl6.saddr = *saddr;
 713	fl6.flowi6_oif = icmp6_iif(skb);
 714	fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
 715	fl6.flowi6_mark = mark;
 716	fl6.flowi6_uid = sock_net_uid(net, NULL);
 717	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 718
 719	local_bh_disable();
 720	sk = icmpv6_xmit_lock(net);
 721	if (!sk)
 722		goto out_bh_enable;
 723	sk->sk_mark = mark;
 724	np = inet6_sk(sk);
 725
 726	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 727		fl6.flowi6_oif = np->mcast_oif;
 728	else if (!fl6.flowi6_oif)
 729		fl6.flowi6_oif = np->ucast_oif;
 730
 731	if (ip6_dst_lookup(net, sk, &dst, &fl6))
 
 732		goto out;
 733	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
 734	if (IS_ERR(dst))
 735		goto out;
 736
 737	/* Check the ratelimit */
 738	if ((!(skb->dev->flags & IFF_LOOPBACK) && !icmpv6_global_allow(net, ICMPV6_ECHO_REPLY)) ||
 739	    !icmpv6_xrlim_allow(sk, ICMPV6_ECHO_REPLY, &fl6))
 740		goto out_dst_release;
 
 
 741
 742	idev = __in6_dev_get(skb->dev);
 743
 744	msg.skb = skb;
 745	msg.offset = 0;
 746	msg.type = ICMPV6_ECHO_REPLY;
 747
 748	ipcm6_init_sk(&ipc6, np);
 749	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 750	ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 751
 752	if (ip6_append_data(sk, icmpv6_getfrag, &msg,
 753			    skb->len + sizeof(struct icmp6hdr),
 754			    sizeof(struct icmp6hdr), &ipc6, &fl6,
 755			    (struct rt6_info *)dst, MSG_DONTWAIT)) {
 756		__ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
 757		ip6_flush_pending_frames(sk);
 758	} else {
 759		icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 760					   skb->len + sizeof(struct icmp6hdr));
 761	}
 762out_dst_release:
 
 
 
 
 763	dst_release(dst);
 764out:
 765	icmpv6_xmit_unlock(sk);
 766out_bh_enable:
 767	local_bh_enable();
 768}
 769
 770void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 771{
 772	const struct inet6_protocol *ipprot;
 773	int inner_offset;
 774	__be16 frag_off;
 775	u8 nexthdr;
 776	struct net *net = dev_net(skb->dev);
 777
 778	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 779		goto out;
 780
 781	nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
 782	if (ipv6_ext_hdr(nexthdr)) {
 783		/* now skip over extension headers */
 784		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
 785						&nexthdr, &frag_off);
 786		if (inner_offset < 0)
 787			goto out;
 788	} else {
 789		inner_offset = sizeof(struct ipv6hdr);
 790	}
 791
 792	/* Checkin header including 8 bytes of inner protocol header. */
 793	if (!pskb_may_pull(skb, inner_offset+8))
 794		goto out;
 795
 796	/* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
 797	   Without this we will not able f.e. to make source routed
 798	   pmtu discovery.
 799	   Corresponding argument (opt) to notifiers is already added.
 800	   --ANK (980726)
 801	 */
 802
 803	ipprot = rcu_dereference(inet6_protos[nexthdr]);
 
 
 
 804	if (ipprot && ipprot->err_handler)
 805		ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
 
 806
 807	raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
 808	return;
 809
 810out:
 811	__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 812}
 813
 814/*
 815 *	Handle icmp messages
 816 */
 817
 818static int icmpv6_rcv(struct sk_buff *skb)
 819{
 820	struct net *net = dev_net(skb->dev);
 821	struct net_device *dev = icmp6_dev(skb);
 822	struct inet6_dev *idev = __in6_dev_get(dev);
 823	const struct in6_addr *saddr, *daddr;
 
 824	struct icmp6hdr *hdr;
 825	u8 type;
 826	bool success = false;
 827
 828	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 829		struct sec_path *sp = skb_sec_path(skb);
 830		int nh;
 831
 832		if (!(sp && sp->xvec[sp->len - 1]->props.flags &
 833				 XFRM_STATE_ICMP))
 834			goto drop_no_count;
 835
 836		if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
 837			goto drop_no_count;
 838
 839		nh = skb_network_offset(skb);
 840		skb_set_network_header(skb, sizeof(*hdr));
 841
 842		if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
 843			goto drop_no_count;
 844
 845		skb_set_network_header(skb, nh);
 846	}
 847
 848	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
 849
 850	saddr = &ipv6_hdr(skb)->saddr;
 851	daddr = &ipv6_hdr(skb)->daddr;
 852
 853	if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
 854		net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
 855				    saddr, daddr);
 856		goto csum_error;
 
 
 
 
 
 
 
 
 
 
 
 857	}
 858
 859	if (!pskb_pull(skb, sizeof(*hdr)))
 860		goto discard_it;
 861
 862	hdr = icmp6_hdr(skb);
 863
 864	type = hdr->icmp6_type;
 865
 866	ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
 867
 868	switch (type) {
 869	case ICMPV6_ECHO_REQUEST:
 870		if (!net->ipv6.sysctl.icmpv6_echo_ignore_all)
 871			icmpv6_echo_reply(skb);
 872		break;
 873
 874	case ICMPV6_ECHO_REPLY:
 875		success = ping_rcv(skb);
 876		break;
 877
 878	case ICMPV6_PKT_TOOBIG:
 879		/* BUGGG_FUTURE: if packet contains rthdr, we cannot update
 880		   standard destination cache. Seems, only "advanced"
 881		   destination cache will allow to solve this problem
 882		   --ANK (980726)
 883		 */
 884		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 885			goto discard_it;
 886		hdr = icmp6_hdr(skb);
 
 
 
 
 
 
 
 887
 888		/* to notify */
 889		/* fall through */
 890	case ICMPV6_DEST_UNREACH:
 891	case ICMPV6_TIME_EXCEED:
 892	case ICMPV6_PARAMPROB:
 893		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 894		break;
 895
 896	case NDISC_ROUTER_SOLICITATION:
 897	case NDISC_ROUTER_ADVERTISEMENT:
 898	case NDISC_NEIGHBOUR_SOLICITATION:
 899	case NDISC_NEIGHBOUR_ADVERTISEMENT:
 900	case NDISC_REDIRECT:
 901		ndisc_rcv(skb);
 902		break;
 903
 904	case ICMPV6_MGM_QUERY:
 905		igmp6_event_query(skb);
 906		break;
 907
 908	case ICMPV6_MGM_REPORT:
 909		igmp6_event_report(skb);
 910		break;
 911
 912	case ICMPV6_MGM_REDUCTION:
 913	case ICMPV6_NI_QUERY:
 914	case ICMPV6_NI_REPLY:
 915	case ICMPV6_MLD2_REPORT:
 916	case ICMPV6_DHAAD_REQUEST:
 917	case ICMPV6_DHAAD_REPLY:
 918	case ICMPV6_MOBILE_PREFIX_SOL:
 919	case ICMPV6_MOBILE_PREFIX_ADV:
 920		break;
 921
 922	default:
 
 
 923		/* informational */
 924		if (type & ICMPV6_INFOMSG_MASK)
 925			break;
 926
 927		net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
 928				    saddr, daddr);
 929
 930		/*
 931		 * error of unknown type.
 932		 * must pass to upper level
 933		 */
 934
 935		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 936	}
 937
 938	/* until the v6 path can be better sorted assume failure and
 939	 * preserve the status quo behaviour for the rest of the paths to here
 940	 */
 941	if (success)
 942		consume_skb(skb);
 943	else
 944		kfree_skb(skb);
 945
 946	return 0;
 947
 948csum_error:
 949	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
 950discard_it:
 951	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
 952drop_no_count:
 953	kfree_skb(skb);
 954	return 0;
 955}
 956
 957void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
 958		      u8 type,
 959		      const struct in6_addr *saddr,
 960		      const struct in6_addr *daddr,
 961		      int oif)
 962{
 963	memset(fl6, 0, sizeof(*fl6));
 964	fl6->saddr = *saddr;
 965	fl6->daddr = *daddr;
 966	fl6->flowi6_proto	= IPPROTO_ICMPV6;
 967	fl6->fl6_icmp_type	= type;
 968	fl6->fl6_icmp_code	= 0;
 969	fl6->flowi6_oif		= oif;
 970	security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 971}
 972
 973static void __net_exit icmpv6_sk_exit(struct net *net)
 974{
 975	int i;
 976
 977	for_each_possible_cpu(i)
 978		inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv6.icmp_sk, i));
 979	free_percpu(net->ipv6.icmp_sk);
 980}
 981
 982static int __net_init icmpv6_sk_init(struct net *net)
 983{
 984	struct sock *sk;
 985	int err, i;
 986
 987	net->ipv6.icmp_sk = alloc_percpu(struct sock *);
 988	if (!net->ipv6.icmp_sk)
 
 989		return -ENOMEM;
 990
 991	for_each_possible_cpu(i) {
 992		err = inet_ctl_sock_create(&sk, PF_INET6,
 993					   SOCK_RAW, IPPROTO_ICMPV6, net);
 994		if (err < 0) {
 995			pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
 
 
 996			       err);
 997			goto fail;
 998		}
 999
1000		*per_cpu_ptr(net->ipv6.icmp_sk, i) = sk;
 
 
 
 
 
 
 
 
 
1001
1002		/* Enough space for 2 64K ICMP packets, including
1003		 * sk_buff struct overhead.
1004		 */
1005		sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
 
1006	}
1007	return 0;
1008
1009 fail:
1010	icmpv6_sk_exit(net);
 
 
1011	return err;
1012}
1013
 
 
 
 
 
 
 
 
 
 
1014static struct pernet_operations icmpv6_sk_ops = {
1015	.init = icmpv6_sk_init,
1016	.exit = icmpv6_sk_exit,
1017};
1018
1019int __init icmpv6_init(void)
1020{
1021	int err;
1022
1023	err = register_pernet_subsys(&icmpv6_sk_ops);
1024	if (err < 0)
1025		return err;
1026
1027	err = -EAGAIN;
1028	if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1029		goto fail;
1030
1031	err = inet6_register_icmp_sender(icmp6_send);
1032	if (err)
1033		goto sender_reg_err;
1034	return 0;
1035
1036sender_reg_err:
1037	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1038fail:
1039	pr_err("Failed to register ICMP6 protocol\n");
1040	unregister_pernet_subsys(&icmpv6_sk_ops);
1041	return err;
1042}
1043
1044void icmpv6_cleanup(void)
1045{
1046	inet6_unregister_icmp_sender(icmp6_send);
1047	unregister_pernet_subsys(&icmpv6_sk_ops);
1048	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1049}
1050
1051
1052static const struct icmp6_err {
1053	int err;
1054	int fatal;
1055} tab_unreach[] = {
1056	{	/* NOROUTE */
1057		.err	= ENETUNREACH,
1058		.fatal	= 0,
1059	},
1060	{	/* ADM_PROHIBITED */
1061		.err	= EACCES,
1062		.fatal	= 1,
1063	},
1064	{	/* Was NOT_NEIGHBOUR, now reserved */
1065		.err	= EHOSTUNREACH,
1066		.fatal	= 0,
1067	},
1068	{	/* ADDR_UNREACH	*/
1069		.err	= EHOSTUNREACH,
1070		.fatal	= 0,
1071	},
1072	{	/* PORT_UNREACH	*/
1073		.err	= ECONNREFUSED,
1074		.fatal	= 1,
1075	},
1076	{	/* POLICY_FAIL */
1077		.err	= EACCES,
1078		.fatal	= 1,
1079	},
1080	{	/* REJECT_ROUTE	*/
1081		.err	= EACCES,
1082		.fatal	= 1,
1083	},
1084};
1085
1086int icmpv6_err_convert(u8 type, u8 code, int *err)
1087{
1088	int fatal = 0;
1089
1090	*err = EPROTO;
1091
1092	switch (type) {
1093	case ICMPV6_DEST_UNREACH:
1094		fatal = 1;
1095		if (code < ARRAY_SIZE(tab_unreach)) {
1096			*err  = tab_unreach[code].err;
1097			fatal = tab_unreach[code].fatal;
1098		}
1099		break;
1100
1101	case ICMPV6_PKT_TOOBIG:
1102		*err = EMSGSIZE;
1103		break;
1104
1105	case ICMPV6_PARAMPROB:
1106		*err = EPROTO;
1107		fatal = 1;
1108		break;
1109
1110	case ICMPV6_TIME_EXCEED:
1111		*err = EHOSTUNREACH;
1112		break;
1113	}
1114
1115	return fatal;
1116}
 
1117EXPORT_SYMBOL(icmpv6_err_convert);
1118
1119#ifdef CONFIG_SYSCTL
1120static struct ctl_table ipv6_icmp_table_template[] = {
1121	{
1122		.procname	= "ratelimit",
1123		.data		= &init_net.ipv6.sysctl.icmpv6_time,
1124		.maxlen		= sizeof(int),
1125		.mode		= 0644,
1126		.proc_handler	= proc_dointvec_ms_jiffies,
1127	},
1128	{
1129		.procname	= "echo_ignore_all",
1130		.data		= &init_net.ipv6.sysctl.icmpv6_echo_ignore_all,
1131		.maxlen		= sizeof(int),
1132		.mode		= 0644,
1133		.proc_handler = proc_dointvec,
1134	},
1135	{
1136		.procname	= "echo_ignore_multicast",
1137		.data		= &init_net.ipv6.sysctl.icmpv6_echo_ignore_multicast,
1138		.maxlen		= sizeof(int),
1139		.mode		= 0644,
1140		.proc_handler = proc_dointvec,
1141	},
1142	{
1143		.procname	= "echo_ignore_anycast",
1144		.data		= &init_net.ipv6.sysctl.icmpv6_echo_ignore_anycast,
1145		.maxlen		= sizeof(int),
1146		.mode		= 0644,
1147		.proc_handler = proc_dointvec,
1148	},
1149	{
1150		.procname	= "ratemask",
1151		.data		= &init_net.ipv6.sysctl.icmpv6_ratemask_ptr,
1152		.maxlen		= ICMPV6_MSG_MAX + 1,
1153		.mode		= 0644,
1154		.proc_handler = proc_do_large_bitmap,
1155	},
1156	{ },
1157};
1158
1159struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1160{
1161	struct ctl_table *table;
1162
1163	table = kmemdup(ipv6_icmp_table_template,
1164			sizeof(ipv6_icmp_table_template),
1165			GFP_KERNEL);
1166
1167	if (table) {
1168		table[0].data = &net->ipv6.sysctl.icmpv6_time;
1169		table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all;
1170		table[2].data = &net->ipv6.sysctl.icmpv6_echo_ignore_multicast;
1171		table[3].data = &net->ipv6.sysctl.icmpv6_echo_ignore_anycast;
1172		table[4].data = &net->ipv6.sysctl.icmpv6_ratemask_ptr;
1173	}
1174	return table;
1175}
1176#endif