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v4.17
   1/*
   2 *	Internet Control Message Protocol (ICMPv6)
   3 *	Linux INET6 implementation
   4 *
   5 *	Authors:
   6 *	Pedro Roque		<roque@di.fc.ul.pt>
   7 *
   8 *	Based on net/ipv4/icmp.c
   9 *
  10 *	RFC 1885
  11 *
  12 *	This program is free software; you can redistribute it and/or
  13 *      modify it under the terms of the GNU General Public License
  14 *      as published by the Free Software Foundation; either version
  15 *      2 of the License, or (at your option) any later version.
  16 */
  17
  18/*
  19 *	Changes:
  20 *
  21 *	Andi Kleen		:	exception handling
  22 *	Andi Kleen			add rate limits. never reply to a icmp.
  23 *					add more length checks and other fixes.
  24 *	yoshfuji		:	ensure to sent parameter problem for
  25 *					fragments.
  26 *	YOSHIFUJI Hideaki @USAGI:	added sysctl for icmp rate limit.
  27 *	Randy Dunlap and
  28 *	YOSHIFUJI Hideaki @USAGI:	Per-interface statistics support
  29 *	Kazunori MIYAZAWA @USAGI:       change output process to use ip6_append_data
  30 */
  31
  32#define pr_fmt(fmt) "IPv6: " fmt
  33
  34#include <linux/module.h>
  35#include <linux/errno.h>
  36#include <linux/types.h>
  37#include <linux/socket.h>
  38#include <linux/in.h>
  39#include <linux/kernel.h>
  40#include <linux/sockios.h>
  41#include <linux/net.h>
  42#include <linux/skbuff.h>
  43#include <linux/init.h>
  44#include <linux/netfilter.h>
  45#include <linux/slab.h>
  46
  47#ifdef CONFIG_SYSCTL
  48#include <linux/sysctl.h>
  49#endif
  50
  51#include <linux/inet.h>
  52#include <linux/netdevice.h>
  53#include <linux/icmpv6.h>
  54
  55#include <net/ip.h>
  56#include <net/sock.h>
  57
  58#include <net/ipv6.h>
  59#include <net/ip6_checksum.h>
  60#include <net/ping.h>
  61#include <net/protocol.h>
  62#include <net/raw.h>
  63#include <net/rawv6.h>
  64#include <net/transp_v6.h>
  65#include <net/ip6_route.h>
  66#include <net/addrconf.h>
  67#include <net/icmp.h>
  68#include <net/xfrm.h>
  69#include <net/inet_common.h>
  70#include <net/dsfield.h>
  71#include <net/l3mdev.h>
  72
  73#include <linux/uaccess.h>
  74
  75/*
  76 *	The ICMP socket(s). This is the most convenient way to flow control
  77 *	our ICMP output as well as maintain a clean interface throughout
  78 *	all layers. All Socketless IP sends will soon be gone.
  79 *
  80 *	On SMP we have one ICMP socket per-cpu.
  81 */
  82static inline struct sock *icmpv6_sk(struct net *net)
  83{
  84	return net->ipv6.icmp_sk[smp_processor_id()];
  85}
  86
  87static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
  88		       u8 type, u8 code, int offset, __be32 info)
  89{
  90	/* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
  91	struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
  92	struct net *net = dev_net(skb->dev);
  93
  94	if (type == ICMPV6_PKT_TOOBIG)
  95		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
  96	else if (type == NDISC_REDIRECT)
  97		ip6_redirect(skb, net, skb->dev->ifindex, 0,
  98			     sock_net_uid(net, NULL));
  99
 100	if (!(type & ICMPV6_INFOMSG_MASK))
 101		if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
 102			ping_err(skb, offset, ntohl(info));
 103}
 104
 105static int icmpv6_rcv(struct sk_buff *skb);
 106
 107static const struct inet6_protocol icmpv6_protocol = {
 108	.handler	=	icmpv6_rcv,
 109	.err_handler	=	icmpv6_err,
 110	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
 111};
 112
 113/* Called with BH disabled */
 114static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
 115{
 116	struct sock *sk;
 117
 
 
 118	sk = icmpv6_sk(net);
 119	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
 120		/* This can happen if the output path (f.e. SIT or
 121		 * ip6ip6 tunnel) signals dst_link_failure() for an
 122		 * outgoing ICMP6 packet.
 123		 */
 
 124		return NULL;
 125	}
 126	return sk;
 127}
 128
 129static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
 130{
 131	spin_unlock(&sk->sk_lock.slock);
 132}
 133
 134/*
 135 * Figure out, may we reply to this packet with icmp error.
 136 *
 137 * We do not reply, if:
 138 *	- it was icmp error message.
 139 *	- it is truncated, so that it is known, that protocol is ICMPV6
 140 *	  (i.e. in the middle of some exthdr)
 141 *
 142 *	--ANK (980726)
 143 */
 144
 145static bool is_ineligible(const struct sk_buff *skb)
 146{
 147	int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
 148	int len = skb->len - ptr;
 149	__u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 150	__be16 frag_off;
 151
 152	if (len < 0)
 153		return true;
 154
 155	ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
 156	if (ptr < 0)
 157		return false;
 158	if (nexthdr == IPPROTO_ICMPV6) {
 159		u8 _type, *tp;
 160		tp = skb_header_pointer(skb,
 161			ptr+offsetof(struct icmp6hdr, icmp6_type),
 162			sizeof(_type), &_type);
 163		if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
 164			return true;
 165	}
 166	return false;
 167}
 168
 169static bool icmpv6_mask_allow(int type)
 170{
 171	/* Informational messages are not limited. */
 172	if (type & ICMPV6_INFOMSG_MASK)
 173		return true;
 174
 175	/* Do not limit pmtu discovery, it would break it. */
 176	if (type == ICMPV6_PKT_TOOBIG)
 177		return true;
 178
 179	return false;
 180}
 181
 182static bool icmpv6_global_allow(int type)
 183{
 184	if (icmpv6_mask_allow(type))
 185		return true;
 186
 187	if (icmp_global_allow())
 188		return true;
 189
 190	return false;
 191}
 192
 193/*
 194 * Check the ICMP output rate limit
 195 */
 196static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
 197			       struct flowi6 *fl6)
 198{
 199	struct net *net = sock_net(sk);
 200	struct dst_entry *dst;
 201	bool res = false;
 202
 203	if (icmpv6_mask_allow(type))
 
 
 
 
 
 204		return true;
 205
 206	/*
 207	 * Look up the output route.
 208	 * XXX: perhaps the expire for routing entries cloned by
 209	 * this lookup should be more aggressive (not longer than timeout).
 210	 */
 211	dst = ip6_route_output(net, sk, fl6);
 212	if (dst->error) {
 213		IP6_INC_STATS(net, ip6_dst_idev(dst),
 214			      IPSTATS_MIB_OUTNOROUTES);
 215	} else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
 216		res = true;
 217	} else {
 218		struct rt6_info *rt = (struct rt6_info *)dst;
 219		int tmo = net->ipv6.sysctl.icmpv6_time;
 220		struct inet_peer *peer;
 221
 222		/* Give more bandwidth to wider prefixes. */
 223		if (rt->rt6i_dst.plen < 128)
 224			tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
 225
 226		peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1);
 227		res = inet_peer_xrlim_allow(peer, tmo);
 228		if (peer)
 229			inet_putpeer(peer);
 
 
 
 
 
 230	}
 231	dst_release(dst);
 232	return res;
 233}
 234
 235/*
 236 *	an inline helper for the "simple" if statement below
 237 *	checks if parameter problem report is caused by an
 238 *	unrecognized IPv6 option that has the Option Type
 239 *	highest-order two bits set to 10
 240 */
 241
 242static bool opt_unrec(struct sk_buff *skb, __u32 offset)
 243{
 244	u8 _optval, *op;
 245
 246	offset += skb_network_offset(skb);
 247	op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
 248	if (!op)
 249		return true;
 250	return (*op & 0xC0) == 0x80;
 251}
 252
 253void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 254				struct icmp6hdr *thdr, int len)
 255{
 256	struct sk_buff *skb;
 257	struct icmp6hdr *icmp6h;
 
 258
 259	skb = skb_peek(&sk->sk_write_queue);
 260	if (!skb)
 261		return;
 262
 263	icmp6h = icmp6_hdr(skb);
 264	memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
 265	icmp6h->icmp6_cksum = 0;
 266
 267	if (skb_queue_len(&sk->sk_write_queue) == 1) {
 268		skb->csum = csum_partial(icmp6h,
 269					sizeof(struct icmp6hdr), skb->csum);
 270		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
 271						      &fl6->daddr,
 272						      len, fl6->flowi6_proto,
 273						      skb->csum);
 274	} else {
 275		__wsum tmp_csum = 0;
 276
 277		skb_queue_walk(&sk->sk_write_queue, skb) {
 278			tmp_csum = csum_add(tmp_csum, skb->csum);
 279		}
 280
 281		tmp_csum = csum_partial(icmp6h,
 282					sizeof(struct icmp6hdr), tmp_csum);
 283		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
 284						      &fl6->daddr,
 285						      len, fl6->flowi6_proto,
 286						      tmp_csum);
 287	}
 288	ip6_push_pending_frames(sk);
 
 
 289}
 290
 291struct icmpv6_msg {
 292	struct sk_buff	*skb;
 293	int		offset;
 294	uint8_t		type;
 295};
 296
 297static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
 298{
 299	struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
 300	struct sk_buff *org_skb = msg->skb;
 301	__wsum csum = 0;
 302
 303	csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
 304				      to, len, csum);
 305	skb->csum = csum_block_add(skb->csum, csum, odd);
 306	if (!(msg->type & ICMPV6_INFOMSG_MASK))
 307		nf_ct_attach(skb, org_skb);
 308	return 0;
 309}
 310
 311#if IS_ENABLED(CONFIG_IPV6_MIP6)
 312static void mip6_addr_swap(struct sk_buff *skb)
 313{
 314	struct ipv6hdr *iph = ipv6_hdr(skb);
 315	struct inet6_skb_parm *opt = IP6CB(skb);
 316	struct ipv6_destopt_hao *hao;
 317	struct in6_addr tmp;
 318	int off;
 319
 320	if (opt->dsthao) {
 321		off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
 322		if (likely(off >= 0)) {
 323			hao = (struct ipv6_destopt_hao *)
 324					(skb_network_header(skb) + off);
 325			tmp = iph->saddr;
 326			iph->saddr = hao->addr;
 327			hao->addr = tmp;
 328		}
 329	}
 330}
 331#else
 332static inline void mip6_addr_swap(struct sk_buff *skb) {}
 333#endif
 334
 335static struct dst_entry *icmpv6_route_lookup(struct net *net,
 336					     struct sk_buff *skb,
 337					     struct sock *sk,
 338					     struct flowi6 *fl6)
 339{
 340	struct dst_entry *dst, *dst2;
 341	struct flowi6 fl2;
 342	int err;
 343
 344	err = ip6_dst_lookup(net, sk, &dst, fl6);
 345	if (err)
 346		return ERR_PTR(err);
 347
 348	/*
 349	 * We won't send icmp if the destination is known
 350	 * anycast.
 351	 */
 352	if (ipv6_anycast_destination(dst, &fl6->daddr)) {
 353		net_dbg_ratelimited("icmp6_send: acast source\n");
 354		dst_release(dst);
 355		return ERR_PTR(-EINVAL);
 356	}
 357
 358	/* No need to clone since we're just using its address. */
 359	dst2 = dst;
 360
 361	dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
 362	if (!IS_ERR(dst)) {
 363		if (dst != dst2)
 364			return dst;
 365	} else {
 366		if (PTR_ERR(dst) == -EPERM)
 367			dst = NULL;
 368		else
 369			return dst;
 370	}
 371
 372	err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
 373	if (err)
 374		goto relookup_failed;
 375
 376	err = ip6_dst_lookup(net, sk, &dst2, &fl2);
 377	if (err)
 378		goto relookup_failed;
 379
 380	dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
 381	if (!IS_ERR(dst2)) {
 382		dst_release(dst);
 383		dst = dst2;
 384	} else {
 385		err = PTR_ERR(dst2);
 386		if (err == -EPERM) {
 387			dst_release(dst);
 388			return dst2;
 389		} else
 390			goto relookup_failed;
 391	}
 392
 393relookup_failed:
 394	if (dst)
 395		return dst;
 396	return ERR_PTR(err);
 397}
 398
 399static int icmp6_iif(const struct sk_buff *skb)
 400{
 401	int iif = skb->dev->ifindex;
 402
 403	/* for local traffic to local address, skb dev is the loopback
 404	 * device. Check if there is a dst attached to the skb and if so
 405	 * get the real device index.
 406	 */
 407	if (unlikely(iif == LOOPBACK_IFINDEX)) {
 408		const struct rt6_info *rt6 = skb_rt6_info(skb);
 409
 410		if (rt6)
 411			iif = rt6->rt6i_idev->dev->ifindex;
 412	}
 413
 414	return iif;
 415}
 416
 417/*
 418 *	Send an ICMP message in response to a packet in error
 419 */
 420static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
 421		       const struct in6_addr *force_saddr)
 422{
 423	struct net *net = dev_net(skb->dev);
 424	struct inet6_dev *idev = NULL;
 425	struct ipv6hdr *hdr = ipv6_hdr(skb);
 426	struct sock *sk;
 427	struct ipv6_pinfo *np;
 428	const struct in6_addr *saddr = NULL;
 429	struct dst_entry *dst;
 430	struct icmp6hdr tmp_hdr;
 431	struct flowi6 fl6;
 432	struct icmpv6_msg msg;
 433	struct sockcm_cookie sockc_unused = {0};
 434	struct ipcm6_cookie ipc6;
 435	int iif = 0;
 436	int addr_type = 0;
 437	int len;
 
 
 438	u32 mark = IP6_REPLY_MARK(net, skb->mark);
 439
 440	if ((u8 *)hdr < skb->head ||
 441	    (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
 442		return;
 443
 444	/*
 445	 *	Make sure we respect the rules
 446	 *	i.e. RFC 1885 2.4(e)
 447	 *	Rule (e.1) is enforced by not using icmp6_send
 448	 *	in any code that processes icmp errors.
 449	 */
 450	addr_type = ipv6_addr_type(&hdr->daddr);
 451
 452	if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
 453	    ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
 454		saddr = &hdr->daddr;
 455
 456	/*
 457	 *	Dest addr check
 458	 */
 459
 460	if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
 461		if (type != ICMPV6_PKT_TOOBIG &&
 462		    !(type == ICMPV6_PARAMPROB &&
 463		      code == ICMPV6_UNK_OPTION &&
 464		      (opt_unrec(skb, info))))
 465			return;
 466
 467		saddr = NULL;
 468	}
 469
 470	addr_type = ipv6_addr_type(&hdr->saddr);
 471
 472	/*
 473	 *	Source addr check
 474	 */
 475
 476	if (__ipv6_addr_needs_scope_id(addr_type)) {
 477		iif = icmp6_iif(skb);
 478	} else {
 479		dst = skb_dst(skb);
 480		iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev);
 481	}
 482
 483	/*
 484	 *	Must not send error if the source does not uniquely
 485	 *	identify a single node (RFC2463 Section 2.4).
 486	 *	We check unspecified / multicast addresses here,
 487	 *	and anycast addresses will be checked later.
 488	 */
 489	if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
 490		net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
 491				    &hdr->saddr, &hdr->daddr);
 492		return;
 493	}
 494
 495	/*
 496	 *	Never answer to a ICMP packet.
 497	 */
 498	if (is_ineligible(skb)) {
 499		net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
 500				    &hdr->saddr, &hdr->daddr);
 501		return;
 502	}
 503
 504	/* Needed by both icmp_global_allow and icmpv6_xmit_lock */
 505	local_bh_disable();
 506
 507	/* Check global sysctl_icmp_msgs_per_sec ratelimit */
 508	if (!(skb->dev->flags&IFF_LOOPBACK) && !icmpv6_global_allow(type))
 509		goto out_bh_enable;
 510
 511	mip6_addr_swap(skb);
 512
 513	memset(&fl6, 0, sizeof(fl6));
 514	fl6.flowi6_proto = IPPROTO_ICMPV6;
 515	fl6.daddr = hdr->saddr;
 516	if (force_saddr)
 517		saddr = force_saddr;
 518	if (saddr)
 519		fl6.saddr = *saddr;
 520	fl6.flowi6_mark = mark;
 521	fl6.flowi6_oif = iif;
 522	fl6.fl6_icmp_type = type;
 523	fl6.fl6_icmp_code = code;
 524	fl6.flowi6_uid = sock_net_uid(net, NULL);
 525	fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL);
 526	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 527
 528	sk = icmpv6_xmit_lock(net);
 529	if (!sk)
 530		goto out_bh_enable;
 531
 532	sk->sk_mark = mark;
 533	np = inet6_sk(sk);
 534
 535	if (!icmpv6_xrlim_allow(sk, type, &fl6))
 536		goto out;
 537
 538	tmp_hdr.icmp6_type = type;
 539	tmp_hdr.icmp6_code = code;
 540	tmp_hdr.icmp6_cksum = 0;
 541	tmp_hdr.icmp6_pointer = htonl(info);
 542
 543	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 544		fl6.flowi6_oif = np->mcast_oif;
 545	else if (!fl6.flowi6_oif)
 546		fl6.flowi6_oif = np->ucast_oif;
 547
 548	ipc6.tclass = np->tclass;
 549	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
 550
 551	dst = icmpv6_route_lookup(net, skb, sk, &fl6);
 552	if (IS_ERR(dst))
 553		goto out;
 554
 555	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 556	ipc6.dontfrag = np->dontfrag;
 557	ipc6.opt = NULL;
 558
 559	msg.skb = skb;
 560	msg.offset = skb_network_offset(skb);
 561	msg.type = type;
 562
 563	len = skb->len - msg.offset;
 564	len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
 565	if (len < 0) {
 566		net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
 567				    &hdr->saddr, &hdr->daddr);
 568		goto out_dst_release;
 569	}
 570
 571	rcu_read_lock();
 572	idev = __in6_dev_get(skb->dev);
 573
 574	if (ip6_append_data(sk, icmpv6_getfrag, &msg,
 575			    len + sizeof(struct icmp6hdr),
 576			    sizeof(struct icmp6hdr),
 577			    &ipc6, &fl6, (struct rt6_info *)dst,
 578			    MSG_DONTWAIT, &sockc_unused)) {
 
 579		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
 580		ip6_flush_pending_frames(sk);
 581	} else {
 582		icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 583					   len + sizeof(struct icmp6hdr));
 584	}
 585	rcu_read_unlock();
 586out_dst_release:
 587	dst_release(dst);
 588out:
 589	icmpv6_xmit_unlock(sk);
 590out_bh_enable:
 591	local_bh_enable();
 592}
 593
 594/* Slightly more convenient version of icmp6_send.
 595 */
 596void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
 597{
 598	icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
 599	kfree_skb(skb);
 600}
 601
 602/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
 603 * if sufficient data bytes are available
 604 * @nhs is the size of the tunnel header(s) :
 605 *  Either an IPv4 header for SIT encap
 606 *         an IPv4 header + GRE header for GRE encap
 607 */
 608int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
 609			       unsigned int data_len)
 610{
 611	struct in6_addr temp_saddr;
 612	struct rt6_info *rt;
 613	struct sk_buff *skb2;
 614	u32 info = 0;
 615
 616	if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
 617		return 1;
 618
 619	/* RFC 4884 (partial) support for ICMP extensions */
 620	if (data_len < 128 || (data_len & 7) || skb->len < data_len)
 621		data_len = 0;
 622
 623	skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
 624
 625	if (!skb2)
 626		return 1;
 627
 628	skb_dst_drop(skb2);
 629	skb_pull(skb2, nhs);
 630	skb_reset_network_header(skb2);
 631
 632	rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
 633			skb, 0);
 634
 635	if (rt && rt->dst.dev)
 636		skb2->dev = rt->dst.dev;
 637
 638	ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
 639
 640	if (data_len) {
 641		/* RFC 4884 (partial) support :
 642		 * insert 0 padding at the end, before the extensions
 643		 */
 644		__skb_push(skb2, nhs);
 645		skb_reset_network_header(skb2);
 646		memmove(skb2->data, skb2->data + nhs, data_len - nhs);
 647		memset(skb2->data + data_len - nhs, 0, nhs);
 648		/* RFC 4884 4.5 : Length is measured in 64-bit words,
 649		 * and stored in reserved[0]
 650		 */
 651		info = (data_len/8) << 24;
 652	}
 653	if (type == ICMP_TIME_EXCEEDED)
 654		icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
 655			   info, &temp_saddr);
 656	else
 657		icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
 658			   info, &temp_saddr);
 659	if (rt)
 660		ip6_rt_put(rt);
 661
 662	kfree_skb(skb2);
 663
 664	return 0;
 665}
 666EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
 667
 668static void icmpv6_echo_reply(struct sk_buff *skb)
 669{
 670	struct net *net = dev_net(skb->dev);
 671	struct sock *sk;
 672	struct inet6_dev *idev;
 673	struct ipv6_pinfo *np;
 674	const struct in6_addr *saddr = NULL;
 675	struct icmp6hdr *icmph = icmp6_hdr(skb);
 676	struct icmp6hdr tmp_hdr;
 677	struct flowi6 fl6;
 678	struct icmpv6_msg msg;
 679	struct dst_entry *dst;
 680	struct ipcm6_cookie ipc6;
 
 
 681	u32 mark = IP6_REPLY_MARK(net, skb->mark);
 682	struct sockcm_cookie sockc_unused = {0};
 683
 684	saddr = &ipv6_hdr(skb)->daddr;
 685
 686	if (!ipv6_unicast_destination(skb) &&
 687	    !(net->ipv6.sysctl.anycast_src_echo_reply &&
 688	      ipv6_anycast_destination(skb_dst(skb), saddr)))
 689		saddr = NULL;
 690
 691	memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
 692	tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
 693
 694	memset(&fl6, 0, sizeof(fl6));
 695	fl6.flowi6_proto = IPPROTO_ICMPV6;
 696	fl6.daddr = ipv6_hdr(skb)->saddr;
 697	if (saddr)
 698		fl6.saddr = *saddr;
 699	fl6.flowi6_oif = icmp6_iif(skb);
 700	fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
 701	fl6.flowi6_mark = mark;
 702	fl6.flowi6_uid = sock_net_uid(net, NULL);
 703	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 704
 705	local_bh_disable();
 706	sk = icmpv6_xmit_lock(net);
 707	if (!sk)
 708		goto out_bh_enable;
 709	sk->sk_mark = mark;
 710	np = inet6_sk(sk);
 711
 712	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 713		fl6.flowi6_oif = np->mcast_oif;
 714	else if (!fl6.flowi6_oif)
 715		fl6.flowi6_oif = np->ucast_oif;
 716
 717	if (ip6_dst_lookup(net, sk, &dst, &fl6))
 
 718		goto out;
 719	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
 720	if (IS_ERR(dst))
 721		goto out;
 722
 
 
 723	idev = __in6_dev_get(skb->dev);
 724
 725	msg.skb = skb;
 726	msg.offset = 0;
 727	msg.type = ICMPV6_ECHO_REPLY;
 728
 729	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 730	ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 731	ipc6.dontfrag = np->dontfrag;
 732	ipc6.opt = NULL;
 733
 734	if (ip6_append_data(sk, icmpv6_getfrag, &msg,
 735			    skb->len + sizeof(struct icmp6hdr),
 736			    sizeof(struct icmp6hdr), &ipc6, &fl6,
 737			    (struct rt6_info *)dst, MSG_DONTWAIT,
 738			    &sockc_unused)) {
 739		__ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
 740		ip6_flush_pending_frames(sk);
 741	} else {
 742		icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 743					   skb->len + sizeof(struct icmp6hdr));
 744	}
 745	dst_release(dst);
 746out:
 747	icmpv6_xmit_unlock(sk);
 748out_bh_enable:
 749	local_bh_enable();
 750}
 751
 752void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 753{
 754	const struct inet6_protocol *ipprot;
 755	int inner_offset;
 756	__be16 frag_off;
 757	u8 nexthdr;
 758	struct net *net = dev_net(skb->dev);
 759
 760	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 761		goto out;
 762
 763	nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
 764	if (ipv6_ext_hdr(nexthdr)) {
 765		/* now skip over extension headers */
 766		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
 767						&nexthdr, &frag_off);
 768		if (inner_offset < 0)
 769			goto out;
 770	} else {
 771		inner_offset = sizeof(struct ipv6hdr);
 772	}
 773
 774	/* Checkin header including 8 bytes of inner protocol header. */
 775	if (!pskb_may_pull(skb, inner_offset+8))
 776		goto out;
 777
 778	/* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
 779	   Without this we will not able f.e. to make source routed
 780	   pmtu discovery.
 781	   Corresponding argument (opt) to notifiers is already added.
 782	   --ANK (980726)
 783	 */
 784
 785	ipprot = rcu_dereference(inet6_protos[nexthdr]);
 786	if (ipprot && ipprot->err_handler)
 787		ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
 788
 789	raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
 790	return;
 791
 792out:
 793	__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 794}
 795
 796/*
 797 *	Handle icmp messages
 798 */
 799
 800static int icmpv6_rcv(struct sk_buff *skb)
 801{
 802	struct net_device *dev = skb->dev;
 803	struct inet6_dev *idev = __in6_dev_get(dev);
 804	const struct in6_addr *saddr, *daddr;
 805	struct icmp6hdr *hdr;
 806	u8 type;
 807	bool success = false;
 808
 809	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 810		struct sec_path *sp = skb_sec_path(skb);
 811		int nh;
 812
 813		if (!(sp && sp->xvec[sp->len - 1]->props.flags &
 814				 XFRM_STATE_ICMP))
 815			goto drop_no_count;
 816
 817		if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
 818			goto drop_no_count;
 819
 820		nh = skb_network_offset(skb);
 821		skb_set_network_header(skb, sizeof(*hdr));
 822
 823		if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
 824			goto drop_no_count;
 825
 826		skb_set_network_header(skb, nh);
 827	}
 828
 829	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS);
 830
 831	saddr = &ipv6_hdr(skb)->saddr;
 832	daddr = &ipv6_hdr(skb)->daddr;
 833
 834	if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
 835		net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
 836				    saddr, daddr);
 837		goto csum_error;
 838	}
 839
 840	if (!pskb_pull(skb, sizeof(*hdr)))
 841		goto discard_it;
 842
 843	hdr = icmp6_hdr(skb);
 844
 845	type = hdr->icmp6_type;
 846
 847	ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type);
 848
 849	switch (type) {
 850	case ICMPV6_ECHO_REQUEST:
 851		icmpv6_echo_reply(skb);
 852		break;
 853
 854	case ICMPV6_ECHO_REPLY:
 855		success = ping_rcv(skb);
 856		break;
 857
 858	case ICMPV6_PKT_TOOBIG:
 859		/* BUGGG_FUTURE: if packet contains rthdr, we cannot update
 860		   standard destination cache. Seems, only "advanced"
 861		   destination cache will allow to solve this problem
 862		   --ANK (980726)
 863		 */
 864		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 865			goto discard_it;
 866		hdr = icmp6_hdr(skb);
 867
 868		/* to notify */
 869		/* fall through */
 
 
 870	case ICMPV6_DEST_UNREACH:
 871	case ICMPV6_TIME_EXCEED:
 872	case ICMPV6_PARAMPROB:
 873		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 874		break;
 875
 876	case NDISC_ROUTER_SOLICITATION:
 877	case NDISC_ROUTER_ADVERTISEMENT:
 878	case NDISC_NEIGHBOUR_SOLICITATION:
 879	case NDISC_NEIGHBOUR_ADVERTISEMENT:
 880	case NDISC_REDIRECT:
 881		ndisc_rcv(skb);
 882		break;
 883
 884	case ICMPV6_MGM_QUERY:
 885		igmp6_event_query(skb);
 886		break;
 887
 888	case ICMPV6_MGM_REPORT:
 889		igmp6_event_report(skb);
 890		break;
 891
 892	case ICMPV6_MGM_REDUCTION:
 893	case ICMPV6_NI_QUERY:
 894	case ICMPV6_NI_REPLY:
 895	case ICMPV6_MLD2_REPORT:
 896	case ICMPV6_DHAAD_REQUEST:
 897	case ICMPV6_DHAAD_REPLY:
 898	case ICMPV6_MOBILE_PREFIX_SOL:
 899	case ICMPV6_MOBILE_PREFIX_ADV:
 900		break;
 901
 902	default:
 903		/* informational */
 904		if (type & ICMPV6_INFOMSG_MASK)
 905			break;
 906
 907		net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
 908				    saddr, daddr);
 909
 910		/*
 911		 * error of unknown type.
 912		 * must pass to upper level
 913		 */
 914
 915		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 916	}
 917
 918	/* until the v6 path can be better sorted assume failure and
 919	 * preserve the status quo behaviour for the rest of the paths to here
 920	 */
 921	if (success)
 922		consume_skb(skb);
 923	else
 924		kfree_skb(skb);
 925
 926	return 0;
 927
 928csum_error:
 929	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
 930discard_it:
 931	__ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS);
 932drop_no_count:
 933	kfree_skb(skb);
 934	return 0;
 935}
 936
 937void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
 938		      u8 type,
 939		      const struct in6_addr *saddr,
 940		      const struct in6_addr *daddr,
 941		      int oif)
 942{
 943	memset(fl6, 0, sizeof(*fl6));
 944	fl6->saddr = *saddr;
 945	fl6->daddr = *daddr;
 946	fl6->flowi6_proto	= IPPROTO_ICMPV6;
 947	fl6->fl6_icmp_type	= type;
 948	fl6->fl6_icmp_code	= 0;
 949	fl6->flowi6_oif		= oif;
 950	security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 951}
 952
 953static int __net_init icmpv6_sk_init(struct net *net)
 954{
 955	struct sock *sk;
 956	int err, i, j;
 957
 958	net->ipv6.icmp_sk =
 959		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
 960	if (!net->ipv6.icmp_sk)
 961		return -ENOMEM;
 962
 963	for_each_possible_cpu(i) {
 964		err = inet_ctl_sock_create(&sk, PF_INET6,
 965					   SOCK_RAW, IPPROTO_ICMPV6, net);
 966		if (err < 0) {
 967			pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
 968			       err);
 969			goto fail;
 970		}
 971
 972		net->ipv6.icmp_sk[i] = sk;
 973
 974		/* Enough space for 2 64K ICMP packets, including
 975		 * sk_buff struct overhead.
 976		 */
 977		sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
 978	}
 979	return 0;
 980
 981 fail:
 982	for (j = 0; j < i; j++)
 983		inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
 984	kfree(net->ipv6.icmp_sk);
 985	return err;
 986}
 987
 988static void __net_exit icmpv6_sk_exit(struct net *net)
 989{
 990	int i;
 991
 992	for_each_possible_cpu(i) {
 993		inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
 994	}
 995	kfree(net->ipv6.icmp_sk);
 996}
 997
 998static struct pernet_operations icmpv6_sk_ops = {
 999	.init = icmpv6_sk_init,
1000	.exit = icmpv6_sk_exit,
1001};
1002
1003int __init icmpv6_init(void)
1004{
1005	int err;
1006
1007	err = register_pernet_subsys(&icmpv6_sk_ops);
1008	if (err < 0)
1009		return err;
1010
1011	err = -EAGAIN;
1012	if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
1013		goto fail;
1014
1015	err = inet6_register_icmp_sender(icmp6_send);
1016	if (err)
1017		goto sender_reg_err;
1018	return 0;
1019
1020sender_reg_err:
1021	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1022fail:
1023	pr_err("Failed to register ICMP6 protocol\n");
1024	unregister_pernet_subsys(&icmpv6_sk_ops);
1025	return err;
1026}
1027
1028void icmpv6_cleanup(void)
1029{
1030	inet6_unregister_icmp_sender(icmp6_send);
1031	unregister_pernet_subsys(&icmpv6_sk_ops);
1032	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
1033}
1034
1035
1036static const struct icmp6_err {
1037	int err;
1038	int fatal;
1039} tab_unreach[] = {
1040	{	/* NOROUTE */
1041		.err	= ENETUNREACH,
1042		.fatal	= 0,
1043	},
1044	{	/* ADM_PROHIBITED */
1045		.err	= EACCES,
1046		.fatal	= 1,
1047	},
1048	{	/* Was NOT_NEIGHBOUR, now reserved */
1049		.err	= EHOSTUNREACH,
1050		.fatal	= 0,
1051	},
1052	{	/* ADDR_UNREACH	*/
1053		.err	= EHOSTUNREACH,
1054		.fatal	= 0,
1055	},
1056	{	/* PORT_UNREACH	*/
1057		.err	= ECONNREFUSED,
1058		.fatal	= 1,
1059	},
1060	{	/* POLICY_FAIL */
1061		.err	= EACCES,
1062		.fatal	= 1,
1063	},
1064	{	/* REJECT_ROUTE	*/
1065		.err	= EACCES,
1066		.fatal	= 1,
1067	},
1068};
1069
1070int icmpv6_err_convert(u8 type, u8 code, int *err)
1071{
1072	int fatal = 0;
1073
1074	*err = EPROTO;
1075
1076	switch (type) {
1077	case ICMPV6_DEST_UNREACH:
1078		fatal = 1;
1079		if (code < ARRAY_SIZE(tab_unreach)) {
1080			*err  = tab_unreach[code].err;
1081			fatal = tab_unreach[code].fatal;
1082		}
1083		break;
1084
1085	case ICMPV6_PKT_TOOBIG:
1086		*err = EMSGSIZE;
1087		break;
1088
1089	case ICMPV6_PARAMPROB:
1090		*err = EPROTO;
1091		fatal = 1;
1092		break;
1093
1094	case ICMPV6_TIME_EXCEED:
1095		*err = EHOSTUNREACH;
1096		break;
1097	}
1098
1099	return fatal;
1100}
1101EXPORT_SYMBOL(icmpv6_err_convert);
1102
1103#ifdef CONFIG_SYSCTL
1104static struct ctl_table ipv6_icmp_table_template[] = {
1105	{
1106		.procname	= "ratelimit",
1107		.data		= &init_net.ipv6.sysctl.icmpv6_time,
1108		.maxlen		= sizeof(int),
1109		.mode		= 0644,
1110		.proc_handler	= proc_dointvec_ms_jiffies,
1111	},
1112	{ },
1113};
1114
1115struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1116{
1117	struct ctl_table *table;
1118
1119	table = kmemdup(ipv6_icmp_table_template,
1120			sizeof(ipv6_icmp_table_template),
1121			GFP_KERNEL);
1122
1123	if (table)
1124		table[0].data = &net->ipv6.sysctl.icmpv6_time;
1125
1126	return table;
1127}
1128#endif
v4.6
   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 <asm/uaccess.h>
  74
  75/*
  76 *	The ICMP socket(s). This is the most convenient way to flow control
  77 *	our ICMP output as well as maintain a clean interface throughout
  78 *	all layers. All Socketless IP sends will soon be gone.
  79 *
  80 *	On SMP we have one ICMP socket per-cpu.
  81 */
  82static inline struct sock *icmpv6_sk(struct net *net)
  83{
  84	return net->ipv6.icmp_sk[smp_processor_id()];
  85}
  86
  87static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
  88		       u8 type, u8 code, int offset, __be32 info)
  89{
  90	/* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
  91	struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
  92	struct net *net = dev_net(skb->dev);
  93
  94	if (type == ICMPV6_PKT_TOOBIG)
  95		ip6_update_pmtu(skb, net, info, 0, 0);
  96	else if (type == NDISC_REDIRECT)
  97		ip6_redirect(skb, net, skb->dev->ifindex, 0);
 
  98
  99	if (!(type & ICMPV6_INFOMSG_MASK))
 100		if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
 101			ping_err(skb, offset, info);
 102}
 103
 104static int icmpv6_rcv(struct sk_buff *skb);
 105
 106static const struct inet6_protocol icmpv6_protocol = {
 107	.handler	=	icmpv6_rcv,
 108	.err_handler	=	icmpv6_err,
 109	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
 110};
 111
 
 112static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
 113{
 114	struct sock *sk;
 115
 116	local_bh_disable();
 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		local_bh_enable();
 125		return NULL;
 126	}
 127	return sk;
 128}
 129
 130static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
 131{
 132	spin_unlock_bh(&sk->sk_lock.slock);
 133}
 134
 135/*
 136 * Figure out, may we reply to this packet with icmp error.
 137 *
 138 * We do not reply, if:
 139 *	- it was icmp error message.
 140 *	- it is truncated, so that it is known, that protocol is ICMPV6
 141 *	  (i.e. in the middle of some exthdr)
 142 *
 143 *	--ANK (980726)
 144 */
 145
 146static bool is_ineligible(const struct sk_buff *skb)
 147{
 148	int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
 149	int len = skb->len - ptr;
 150	__u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 151	__be16 frag_off;
 152
 153	if (len < 0)
 154		return true;
 155
 156	ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off);
 157	if (ptr < 0)
 158		return false;
 159	if (nexthdr == IPPROTO_ICMPV6) {
 160		u8 _type, *tp;
 161		tp = skb_header_pointer(skb,
 162			ptr+offsetof(struct icmp6hdr, icmp6_type),
 163			sizeof(_type), &_type);
 164		if (!tp || !(*tp & ICMPV6_INFOMSG_MASK))
 165			return true;
 166	}
 167	return false;
 168}
 169
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 170/*
 171 * Check the ICMP output rate limit
 172 */
 173static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
 174			       struct flowi6 *fl6)
 175{
 176	struct net *net = sock_net(sk);
 177	struct dst_entry *dst;
 178	bool res = false;
 179
 180	/* Informational messages are not limited. */
 181	if (type & ICMPV6_INFOMSG_MASK)
 182		return true;
 183
 184	/* Do not limit pmtu discovery, it would break it. */
 185	if (type == ICMPV6_PKT_TOOBIG)
 186		return true;
 187
 188	/*
 189	 * Look up the output route.
 190	 * XXX: perhaps the expire for routing entries cloned by
 191	 * this lookup should be more aggressive (not longer than timeout).
 192	 */
 193	dst = ip6_route_output(net, sk, fl6);
 194	if (dst->error) {
 195		IP6_INC_STATS(net, ip6_dst_idev(dst),
 196			      IPSTATS_MIB_OUTNOROUTES);
 197	} else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
 198		res = true;
 199	} else {
 200		struct rt6_info *rt = (struct rt6_info *)dst;
 201		int tmo = net->ipv6.sysctl.icmpv6_time;
 
 202
 203		/* Give more bandwidth to wider prefixes. */
 204		if (rt->rt6i_dst.plen < 128)
 205			tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
 206
 207		if (icmp_global_allow()) {
 208			struct inet_peer *peer;
 209
 210			peer = inet_getpeer_v6(net->ipv6.peers,
 211					       &fl6->daddr, 1);
 212			res = inet_peer_xrlim_allow(peer, tmo);
 213			if (peer)
 214				inet_putpeer(peer);
 215		}
 216	}
 217	dst_release(dst);
 218	return res;
 219}
 220
 221/*
 222 *	an inline helper for the "simple" if statement below
 223 *	checks if parameter problem report is caused by an
 224 *	unrecognized IPv6 option that has the Option Type
 225 *	highest-order two bits set to 10
 226 */
 227
 228static bool opt_unrec(struct sk_buff *skb, __u32 offset)
 229{
 230	u8 _optval, *op;
 231
 232	offset += skb_network_offset(skb);
 233	op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
 234	if (!op)
 235		return true;
 236	return (*op & 0xC0) == 0x80;
 237}
 238
 239int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 240			       struct icmp6hdr *thdr, int len)
 241{
 242	struct sk_buff *skb;
 243	struct icmp6hdr *icmp6h;
 244	int err = 0;
 245
 246	skb = skb_peek(&sk->sk_write_queue);
 247	if (!skb)
 248		goto out;
 249
 250	icmp6h = icmp6_hdr(skb);
 251	memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
 252	icmp6h->icmp6_cksum = 0;
 253
 254	if (skb_queue_len(&sk->sk_write_queue) == 1) {
 255		skb->csum = csum_partial(icmp6h,
 256					sizeof(struct icmp6hdr), skb->csum);
 257		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
 258						      &fl6->daddr,
 259						      len, fl6->flowi6_proto,
 260						      skb->csum);
 261	} else {
 262		__wsum tmp_csum = 0;
 263
 264		skb_queue_walk(&sk->sk_write_queue, skb) {
 265			tmp_csum = csum_add(tmp_csum, skb->csum);
 266		}
 267
 268		tmp_csum = csum_partial(icmp6h,
 269					sizeof(struct icmp6hdr), tmp_csum);
 270		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
 271						      &fl6->daddr,
 272						      len, fl6->flowi6_proto,
 273						      tmp_csum);
 274	}
 275	ip6_push_pending_frames(sk);
 276out:
 277	return err;
 278}
 279
 280struct icmpv6_msg {
 281	struct sk_buff	*skb;
 282	int		offset;
 283	uint8_t		type;
 284};
 285
 286static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
 287{
 288	struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
 289	struct sk_buff *org_skb = msg->skb;
 290	__wsum csum = 0;
 291
 292	csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
 293				      to, len, csum);
 294	skb->csum = csum_block_add(skb->csum, csum, odd);
 295	if (!(msg->type & ICMPV6_INFOMSG_MASK))
 296		nf_ct_attach(skb, org_skb);
 297	return 0;
 298}
 299
 300#if IS_ENABLED(CONFIG_IPV6_MIP6)
 301static void mip6_addr_swap(struct sk_buff *skb)
 302{
 303	struct ipv6hdr *iph = ipv6_hdr(skb);
 304	struct inet6_skb_parm *opt = IP6CB(skb);
 305	struct ipv6_destopt_hao *hao;
 306	struct in6_addr tmp;
 307	int off;
 308
 309	if (opt->dsthao) {
 310		off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
 311		if (likely(off >= 0)) {
 312			hao = (struct ipv6_destopt_hao *)
 313					(skb_network_header(skb) + off);
 314			tmp = iph->saddr;
 315			iph->saddr = hao->addr;
 316			hao->addr = tmp;
 317		}
 318	}
 319}
 320#else
 321static inline void mip6_addr_swap(struct sk_buff *skb) {}
 322#endif
 323
 324static struct dst_entry *icmpv6_route_lookup(struct net *net,
 325					     struct sk_buff *skb,
 326					     struct sock *sk,
 327					     struct flowi6 *fl6)
 328{
 329	struct dst_entry *dst, *dst2;
 330	struct flowi6 fl2;
 331	int err;
 332
 333	err = ip6_dst_lookup(net, sk, &dst, fl6);
 334	if (err)
 335		return ERR_PTR(err);
 336
 337	/*
 338	 * We won't send icmp if the destination is known
 339	 * anycast.
 340	 */
 341	if (ipv6_anycast_destination(dst, &fl6->daddr)) {
 342		net_dbg_ratelimited("icmp6_send: acast source\n");
 343		dst_release(dst);
 344		return ERR_PTR(-EINVAL);
 345	}
 346
 347	/* No need to clone since we're just using its address. */
 348	dst2 = dst;
 349
 350	dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
 351	if (!IS_ERR(dst)) {
 352		if (dst != dst2)
 353			return dst;
 354	} else {
 355		if (PTR_ERR(dst) == -EPERM)
 356			dst = NULL;
 357		else
 358			return dst;
 359	}
 360
 361	err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
 362	if (err)
 363		goto relookup_failed;
 364
 365	err = ip6_dst_lookup(net, sk, &dst2, &fl2);
 366	if (err)
 367		goto relookup_failed;
 368
 369	dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
 370	if (!IS_ERR(dst2)) {
 371		dst_release(dst);
 372		dst = dst2;
 373	} else {
 374		err = PTR_ERR(dst2);
 375		if (err == -EPERM) {
 376			dst_release(dst);
 377			return dst2;
 378		} else
 379			goto relookup_failed;
 380	}
 381
 382relookup_failed:
 383	if (dst)
 384		return dst;
 385	return ERR_PTR(err);
 386}
 387
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 388/*
 389 *	Send an ICMP message in response to a packet in error
 390 */
 391static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
 
 392{
 393	struct net *net = dev_net(skb->dev);
 394	struct inet6_dev *idev = NULL;
 395	struct ipv6hdr *hdr = ipv6_hdr(skb);
 396	struct sock *sk;
 397	struct ipv6_pinfo *np;
 398	const struct in6_addr *saddr = NULL;
 399	struct dst_entry *dst;
 400	struct icmp6hdr tmp_hdr;
 401	struct flowi6 fl6;
 402	struct icmpv6_msg msg;
 
 
 403	int iif = 0;
 404	int addr_type = 0;
 405	int len;
 406	int hlimit;
 407	int err = 0;
 408	u32 mark = IP6_REPLY_MARK(net, skb->mark);
 409
 410	if ((u8 *)hdr < skb->head ||
 411	    (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
 412		return;
 413
 414	/*
 415	 *	Make sure we respect the rules
 416	 *	i.e. RFC 1885 2.4(e)
 417	 *	Rule (e.1) is enforced by not using icmp6_send
 418	 *	in any code that processes icmp errors.
 419	 */
 420	addr_type = ipv6_addr_type(&hdr->daddr);
 421
 422	if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
 423	    ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
 424		saddr = &hdr->daddr;
 425
 426	/*
 427	 *	Dest addr check
 428	 */
 429
 430	if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) {
 431		if (type != ICMPV6_PKT_TOOBIG &&
 432		    !(type == ICMPV6_PARAMPROB &&
 433		      code == ICMPV6_UNK_OPTION &&
 434		      (opt_unrec(skb, info))))
 435			return;
 436
 437		saddr = NULL;
 438	}
 439
 440	addr_type = ipv6_addr_type(&hdr->saddr);
 441
 442	/*
 443	 *	Source addr check
 444	 */
 445
 446	if (__ipv6_addr_needs_scope_id(addr_type))
 447		iif = skb->dev->ifindex;
 448	else
 449		iif = l3mdev_master_ifindex(skb->dev);
 
 
 450
 451	/*
 452	 *	Must not send error if the source does not uniquely
 453	 *	identify a single node (RFC2463 Section 2.4).
 454	 *	We check unspecified / multicast addresses here,
 455	 *	and anycast addresses will be checked later.
 456	 */
 457	if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
 458		net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n",
 459				    &hdr->saddr, &hdr->daddr);
 460		return;
 461	}
 462
 463	/*
 464	 *	Never answer to a ICMP packet.
 465	 */
 466	if (is_ineligible(skb)) {
 467		net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n",
 468				    &hdr->saddr, &hdr->daddr);
 469		return;
 470	}
 471
 
 
 
 
 
 
 
 472	mip6_addr_swap(skb);
 473
 474	memset(&fl6, 0, sizeof(fl6));
 475	fl6.flowi6_proto = IPPROTO_ICMPV6;
 476	fl6.daddr = hdr->saddr;
 
 
 477	if (saddr)
 478		fl6.saddr = *saddr;
 479	fl6.flowi6_mark = mark;
 480	fl6.flowi6_oif = iif;
 481	fl6.fl6_icmp_type = type;
 482	fl6.fl6_icmp_code = code;
 
 
 483	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 484
 485	sk = icmpv6_xmit_lock(net);
 486	if (!sk)
 487		return;
 
 488	sk->sk_mark = mark;
 489	np = inet6_sk(sk);
 490
 491	if (!icmpv6_xrlim_allow(sk, type, &fl6))
 492		goto out;
 493
 494	tmp_hdr.icmp6_type = type;
 495	tmp_hdr.icmp6_code = code;
 496	tmp_hdr.icmp6_cksum = 0;
 497	tmp_hdr.icmp6_pointer = htonl(info);
 498
 499	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 500		fl6.flowi6_oif = np->mcast_oif;
 501	else if (!fl6.flowi6_oif)
 502		fl6.flowi6_oif = np->ucast_oif;
 503
 
 
 
 504	dst = icmpv6_route_lookup(net, skb, sk, &fl6);
 505	if (IS_ERR(dst))
 506		goto out;
 507
 508	hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 
 
 509
 510	msg.skb = skb;
 511	msg.offset = skb_network_offset(skb);
 512	msg.type = type;
 513
 514	len = skb->len - msg.offset;
 515	len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr));
 516	if (len < 0) {
 517		net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n",
 518				    &hdr->saddr, &hdr->daddr);
 519		goto out_dst_release;
 520	}
 521
 522	rcu_read_lock();
 523	idev = __in6_dev_get(skb->dev);
 524
 525	err = ip6_append_data(sk, icmpv6_getfrag, &msg,
 526			      len + sizeof(struct icmp6hdr),
 527			      sizeof(struct icmp6hdr), hlimit,
 528			      np->tclass, NULL, &fl6, (struct rt6_info *)dst,
 529			      MSG_DONTWAIT, np->dontfrag);
 530	if (err) {
 531		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
 532		ip6_flush_pending_frames(sk);
 533	} else {
 534		err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 535						 len + sizeof(struct icmp6hdr));
 536	}
 537	rcu_read_unlock();
 538out_dst_release:
 539	dst_release(dst);
 540out:
 541	icmpv6_xmit_unlock(sk);
 
 
 542}
 543
 544/* Slightly more convenient version of icmp6_send.
 545 */
 546void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
 547{
 548	icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
 549	kfree_skb(skb);
 550}
 551
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 552static void icmpv6_echo_reply(struct sk_buff *skb)
 553{
 554	struct net *net = dev_net(skb->dev);
 555	struct sock *sk;
 556	struct inet6_dev *idev;
 557	struct ipv6_pinfo *np;
 558	const struct in6_addr *saddr = NULL;
 559	struct icmp6hdr *icmph = icmp6_hdr(skb);
 560	struct icmp6hdr tmp_hdr;
 561	struct flowi6 fl6;
 562	struct icmpv6_msg msg;
 563	struct dst_entry *dst;
 564	int err = 0;
 565	int hlimit;
 566	u8 tclass;
 567	u32 mark = IP6_REPLY_MARK(net, skb->mark);
 
 568
 569	saddr = &ipv6_hdr(skb)->daddr;
 570
 571	if (!ipv6_unicast_destination(skb) &&
 572	    !(net->ipv6.sysctl.anycast_src_echo_reply &&
 573	      ipv6_anycast_destination(skb_dst(skb), saddr)))
 574		saddr = NULL;
 575
 576	memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
 577	tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
 578
 579	memset(&fl6, 0, sizeof(fl6));
 580	fl6.flowi6_proto = IPPROTO_ICMPV6;
 581	fl6.daddr = ipv6_hdr(skb)->saddr;
 582	if (saddr)
 583		fl6.saddr = *saddr;
 584	fl6.flowi6_oif = l3mdev_fib_oif(skb->dev);
 585	fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
 586	fl6.flowi6_mark = mark;
 
 587	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 588
 
 589	sk = icmpv6_xmit_lock(net);
 590	if (!sk)
 591		return;
 592	sk->sk_mark = mark;
 593	np = inet6_sk(sk);
 594
 595	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 596		fl6.flowi6_oif = np->mcast_oif;
 597	else if (!fl6.flowi6_oif)
 598		fl6.flowi6_oif = np->ucast_oif;
 599
 600	err = ip6_dst_lookup(net, sk, &dst, &fl6);
 601	if (err)
 602		goto out;
 603	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
 604	if (IS_ERR(dst))
 605		goto out;
 606
 607	hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 608
 609	idev = __in6_dev_get(skb->dev);
 610
 611	msg.skb = skb;
 612	msg.offset = 0;
 613	msg.type = ICMPV6_ECHO_REPLY;
 614
 615	tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 616	err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
 617				sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl6,
 618				(struct rt6_info *)dst, MSG_DONTWAIT,
 619				np->dontfrag);
 620
 621	if (err) {
 622		ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
 
 
 
 623		ip6_flush_pending_frames(sk);
 624	} else {
 625		err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 626						 skb->len + sizeof(struct icmp6hdr));
 627	}
 628	dst_release(dst);
 629out:
 630	icmpv6_xmit_unlock(sk);
 
 
 631}
 632
 633void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 634{
 635	const struct inet6_protocol *ipprot;
 636	int inner_offset;
 637	__be16 frag_off;
 638	u8 nexthdr;
 639	struct net *net = dev_net(skb->dev);
 640
 641	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 642		goto out;
 643
 644	nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
 645	if (ipv6_ext_hdr(nexthdr)) {
 646		/* now skip over extension headers */
 647		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
 648						&nexthdr, &frag_off);
 649		if (inner_offset < 0)
 650			goto out;
 651	} else {
 652		inner_offset = sizeof(struct ipv6hdr);
 653	}
 654
 655	/* Checkin header including 8 bytes of inner protocol header. */
 656	if (!pskb_may_pull(skb, inner_offset+8))
 657		goto out;
 658
 659	/* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
 660	   Without this we will not able f.e. to make source routed
 661	   pmtu discovery.
 662	   Corresponding argument (opt) to notifiers is already added.
 663	   --ANK (980726)
 664	 */
 665
 666	ipprot = rcu_dereference(inet6_protos[nexthdr]);
 667	if (ipprot && ipprot->err_handler)
 668		ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
 669
 670	raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
 671	return;
 672
 673out:
 674	ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 675}
 676
 677/*
 678 *	Handle icmp messages
 679 */
 680
 681static int icmpv6_rcv(struct sk_buff *skb)
 682{
 683	struct net_device *dev = skb->dev;
 684	struct inet6_dev *idev = __in6_dev_get(dev);
 685	const struct in6_addr *saddr, *daddr;
 686	struct icmp6hdr *hdr;
 687	u8 type;
 688	bool success = false;
 689
 690	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 691		struct sec_path *sp = skb_sec_path(skb);
 692		int nh;
 693
 694		if (!(sp && sp->xvec[sp->len - 1]->props.flags &
 695				 XFRM_STATE_ICMP))
 696			goto drop_no_count;
 697
 698		if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
 699			goto drop_no_count;
 700
 701		nh = skb_network_offset(skb);
 702		skb_set_network_header(skb, sizeof(*hdr));
 703
 704		if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
 705			goto drop_no_count;
 706
 707		skb_set_network_header(skb, nh);
 708	}
 709
 710	ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
 711
 712	saddr = &ipv6_hdr(skb)->saddr;
 713	daddr = &ipv6_hdr(skb)->daddr;
 714
 715	if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) {
 716		net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n",
 717				    saddr, daddr);
 718		goto csum_error;
 719	}
 720
 721	if (!pskb_pull(skb, sizeof(*hdr)))
 722		goto discard_it;
 723
 724	hdr = icmp6_hdr(skb);
 725
 726	type = hdr->icmp6_type;
 727
 728	ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
 729
 730	switch (type) {
 731	case ICMPV6_ECHO_REQUEST:
 732		icmpv6_echo_reply(skb);
 733		break;
 734
 735	case ICMPV6_ECHO_REPLY:
 736		success = ping_rcv(skb);
 737		break;
 738
 739	case ICMPV6_PKT_TOOBIG:
 740		/* BUGGG_FUTURE: if packet contains rthdr, we cannot update
 741		   standard destination cache. Seems, only "advanced"
 742		   destination cache will allow to solve this problem
 743		   --ANK (980726)
 744		 */
 745		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 746			goto discard_it;
 747		hdr = icmp6_hdr(skb);
 748
 749		/*
 750		 *	Drop through to notify
 751		 */
 752
 753	case ICMPV6_DEST_UNREACH:
 754	case ICMPV6_TIME_EXCEED:
 755	case ICMPV6_PARAMPROB:
 756		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 757		break;
 758
 759	case NDISC_ROUTER_SOLICITATION:
 760	case NDISC_ROUTER_ADVERTISEMENT:
 761	case NDISC_NEIGHBOUR_SOLICITATION:
 762	case NDISC_NEIGHBOUR_ADVERTISEMENT:
 763	case NDISC_REDIRECT:
 764		ndisc_rcv(skb);
 765		break;
 766
 767	case ICMPV6_MGM_QUERY:
 768		igmp6_event_query(skb);
 769		break;
 770
 771	case ICMPV6_MGM_REPORT:
 772		igmp6_event_report(skb);
 773		break;
 774
 775	case ICMPV6_MGM_REDUCTION:
 776	case ICMPV6_NI_QUERY:
 777	case ICMPV6_NI_REPLY:
 778	case ICMPV6_MLD2_REPORT:
 779	case ICMPV6_DHAAD_REQUEST:
 780	case ICMPV6_DHAAD_REPLY:
 781	case ICMPV6_MOBILE_PREFIX_SOL:
 782	case ICMPV6_MOBILE_PREFIX_ADV:
 783		break;
 784
 785	default:
 786		/* informational */
 787		if (type & ICMPV6_INFOMSG_MASK)
 788			break;
 789
 790		net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n",
 791				    saddr, daddr);
 792
 793		/*
 794		 * error of unknown type.
 795		 * must pass to upper level
 796		 */
 797
 798		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 799	}
 800
 801	/* until the v6 path can be better sorted assume failure and
 802	 * preserve the status quo behaviour for the rest of the paths to here
 803	 */
 804	if (success)
 805		consume_skb(skb);
 806	else
 807		kfree_skb(skb);
 808
 809	return 0;
 810
 811csum_error:
 812	ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
 813discard_it:
 814	ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
 815drop_no_count:
 816	kfree_skb(skb);
 817	return 0;
 818}
 819
 820void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
 821		      u8 type,
 822		      const struct in6_addr *saddr,
 823		      const struct in6_addr *daddr,
 824		      int oif)
 825{
 826	memset(fl6, 0, sizeof(*fl6));
 827	fl6->saddr = *saddr;
 828	fl6->daddr = *daddr;
 829	fl6->flowi6_proto	= IPPROTO_ICMPV6;
 830	fl6->fl6_icmp_type	= type;
 831	fl6->fl6_icmp_code	= 0;
 832	fl6->flowi6_oif		= oif;
 833	security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 834}
 835
 836static int __net_init icmpv6_sk_init(struct net *net)
 837{
 838	struct sock *sk;
 839	int err, i, j;
 840
 841	net->ipv6.icmp_sk =
 842		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
 843	if (!net->ipv6.icmp_sk)
 844		return -ENOMEM;
 845
 846	for_each_possible_cpu(i) {
 847		err = inet_ctl_sock_create(&sk, PF_INET6,
 848					   SOCK_RAW, IPPROTO_ICMPV6, net);
 849		if (err < 0) {
 850			pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
 851			       err);
 852			goto fail;
 853		}
 854
 855		net->ipv6.icmp_sk[i] = sk;
 856
 857		/* Enough space for 2 64K ICMP packets, including
 858		 * sk_buff struct overhead.
 859		 */
 860		sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
 861	}
 862	return 0;
 863
 864 fail:
 865	for (j = 0; j < i; j++)
 866		inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
 867	kfree(net->ipv6.icmp_sk);
 868	return err;
 869}
 870
 871static void __net_exit icmpv6_sk_exit(struct net *net)
 872{
 873	int i;
 874
 875	for_each_possible_cpu(i) {
 876		inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
 877	}
 878	kfree(net->ipv6.icmp_sk);
 879}
 880
 881static struct pernet_operations icmpv6_sk_ops = {
 882	.init = icmpv6_sk_init,
 883	.exit = icmpv6_sk_exit,
 884};
 885
 886int __init icmpv6_init(void)
 887{
 888	int err;
 889
 890	err = register_pernet_subsys(&icmpv6_sk_ops);
 891	if (err < 0)
 892		return err;
 893
 894	err = -EAGAIN;
 895	if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
 896		goto fail;
 897
 898	err = inet6_register_icmp_sender(icmp6_send);
 899	if (err)
 900		goto sender_reg_err;
 901	return 0;
 902
 903sender_reg_err:
 904	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 905fail:
 906	pr_err("Failed to register ICMP6 protocol\n");
 907	unregister_pernet_subsys(&icmpv6_sk_ops);
 908	return err;
 909}
 910
 911void icmpv6_cleanup(void)
 912{
 913	inet6_unregister_icmp_sender(icmp6_send);
 914	unregister_pernet_subsys(&icmpv6_sk_ops);
 915	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 916}
 917
 918
 919static const struct icmp6_err {
 920	int err;
 921	int fatal;
 922} tab_unreach[] = {
 923	{	/* NOROUTE */
 924		.err	= ENETUNREACH,
 925		.fatal	= 0,
 926	},
 927	{	/* ADM_PROHIBITED */
 928		.err	= EACCES,
 929		.fatal	= 1,
 930	},
 931	{	/* Was NOT_NEIGHBOUR, now reserved */
 932		.err	= EHOSTUNREACH,
 933		.fatal	= 0,
 934	},
 935	{	/* ADDR_UNREACH	*/
 936		.err	= EHOSTUNREACH,
 937		.fatal	= 0,
 938	},
 939	{	/* PORT_UNREACH	*/
 940		.err	= ECONNREFUSED,
 941		.fatal	= 1,
 942	},
 943	{	/* POLICY_FAIL */
 944		.err	= EACCES,
 945		.fatal	= 1,
 946	},
 947	{	/* REJECT_ROUTE	*/
 948		.err	= EACCES,
 949		.fatal	= 1,
 950	},
 951};
 952
 953int icmpv6_err_convert(u8 type, u8 code, int *err)
 954{
 955	int fatal = 0;
 956
 957	*err = EPROTO;
 958
 959	switch (type) {
 960	case ICMPV6_DEST_UNREACH:
 961		fatal = 1;
 962		if (code < ARRAY_SIZE(tab_unreach)) {
 963			*err  = tab_unreach[code].err;
 964			fatal = tab_unreach[code].fatal;
 965		}
 966		break;
 967
 968	case ICMPV6_PKT_TOOBIG:
 969		*err = EMSGSIZE;
 970		break;
 971
 972	case ICMPV6_PARAMPROB:
 973		*err = EPROTO;
 974		fatal = 1;
 975		break;
 976
 977	case ICMPV6_TIME_EXCEED:
 978		*err = EHOSTUNREACH;
 979		break;
 980	}
 981
 982	return fatal;
 983}
 984EXPORT_SYMBOL(icmpv6_err_convert);
 985
 986#ifdef CONFIG_SYSCTL
 987static struct ctl_table ipv6_icmp_table_template[] = {
 988	{
 989		.procname	= "ratelimit",
 990		.data		= &init_net.ipv6.sysctl.icmpv6_time,
 991		.maxlen		= sizeof(int),
 992		.mode		= 0644,
 993		.proc_handler	= proc_dointvec_ms_jiffies,
 994	},
 995	{ },
 996};
 997
 998struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
 999{
1000	struct ctl_table *table;
1001
1002	table = kmemdup(ipv6_icmp_table_template,
1003			sizeof(ipv6_icmp_table_template),
1004			GFP_KERNEL);
1005
1006	if (table)
1007		table[0].data = &net->ipv6.sysctl.icmpv6_time;
1008
1009	return table;
1010}
1011#endif