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v3.15
 
   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
  72#include <asm/uaccess.h>
  73
  74/*
  75 *	The ICMP socket(s). This is the most convenient way to flow control
  76 *	our ICMP output as well as maintain a clean interface throughout
  77 *	all layers. All Socketless IP sends will soon be gone.
  78 *
  79 *	On SMP we have one ICMP socket per-cpu.
  80 */
  81static inline struct sock *icmpv6_sk(struct net *net)
  82{
  83	return net->ipv6.icmp_sk[smp_processor_id()];
  84}
  85
  86static void icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
  87		       u8 type, u8 code, int offset, __be32 info)
  88{
  89	/* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */
  90	struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset);
  91	struct net *net = dev_net(skb->dev);
  92
  93	if (type == ICMPV6_PKT_TOOBIG)
  94		ip6_update_pmtu(skb, net, info, 0, 0);
  95	else if (type == NDISC_REDIRECT)
  96		ip6_redirect(skb, net, skb->dev->ifindex, 0);
 
  97
  98	if (!(type & ICMPV6_INFOMSG_MASK))
  99		if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST)
 100			ping_err(skb, offset, info);
 
 
 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
 
 111static __inline__ struct sock *icmpv6_xmit_lock(struct net *net)
 112{
 113	struct sock *sk;
 114
 115	local_bh_disable();
 116
 117	sk = icmpv6_sk(net);
 118	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
 119		/* This can happen if the output path (f.e. SIT or
 120		 * ip6ip6 tunnel) signals dst_link_failure() for an
 121		 * outgoing ICMP6 packet.
 122		 */
 123		local_bh_enable();
 124		return NULL;
 125	}
 126	return sk;
 127}
 128
 129static __inline__ void icmpv6_xmit_unlock(struct sock *sk)
 130{
 131	spin_unlock_bh(&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 == NULL ||
 164		    !(*tp & ICMPV6_INFOMSG_MASK))
 165			return true;
 166	}
 167	return false;
 168}
 169
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 170/*
 171 * Check the ICMP output rate limit
 172 */
 173static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
 174				      struct flowi6 *fl6)
 175{
 176	struct dst_entry *dst;
 177	struct net *net = sock_net(sk);
 
 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		struct inet_peer *peer;
 203
 204		/* Give more bandwidth to wider prefixes. */
 205		if (rt->rt6i_dst.plen < 128)
 206			tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
 207
 208		peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
 209		res = inet_peer_xrlim_allow(peer, tmo);
 210		if (peer)
 211			inet_putpeer(peer);
 212	}
 213	dst_release(dst);
 214	return res;
 215}
 216
 217/*
 218 *	an inline helper for the "simple" if statement below
 219 *	checks if parameter problem report is caused by an
 220 *	unrecognized IPv6 option that has the Option Type
 221 *	highest-order two bits set to 10
 222 */
 223
 224static bool opt_unrec(struct sk_buff *skb, __u32 offset)
 225{
 226	u8 _optval, *op;
 227
 228	offset += skb_network_offset(skb);
 229	op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval);
 230	if (op == NULL)
 231		return true;
 232	return (*op & 0xC0) == 0x80;
 233}
 234
 235int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,
 236			       struct icmp6hdr *thdr, int len)
 237{
 238	struct sk_buff *skb;
 239	struct icmp6hdr *icmp6h;
 240	int err = 0;
 241
 242	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
 243		goto out;
 
 244
 245	icmp6h = icmp6_hdr(skb);
 246	memcpy(icmp6h, thdr, sizeof(struct icmp6hdr));
 247	icmp6h->icmp6_cksum = 0;
 248
 249	if (skb_queue_len(&sk->sk_write_queue) == 1) {
 250		skb->csum = csum_partial(icmp6h,
 251					sizeof(struct icmp6hdr), skb->csum);
 252		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
 253						      &fl6->daddr,
 254						      len, fl6->flowi6_proto,
 255						      skb->csum);
 256	} else {
 257		__wsum tmp_csum = 0;
 258
 259		skb_queue_walk(&sk->sk_write_queue, skb) {
 260			tmp_csum = csum_add(tmp_csum, skb->csum);
 261		}
 262
 263		tmp_csum = csum_partial(icmp6h,
 264					sizeof(struct icmp6hdr), tmp_csum);
 265		icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr,
 266						      &fl6->daddr,
 267						      len, fl6->flowi6_proto,
 268						      tmp_csum);
 269	}
 270	ip6_push_pending_frames(sk);
 271out:
 272	return err;
 273}
 274
 275struct icmpv6_msg {
 276	struct sk_buff	*skb;
 277	int		offset;
 278	uint8_t		type;
 279};
 280
 281static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
 282{
 283	struct icmpv6_msg *msg = (struct icmpv6_msg *) from;
 284	struct sk_buff *org_skb = msg->skb;
 285	__wsum csum = 0;
 286
 287	csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset,
 288				      to, len, csum);
 289	skb->csum = csum_block_add(skb->csum, csum, odd);
 290	if (!(msg->type & ICMPV6_INFOMSG_MASK))
 291		nf_ct_attach(skb, org_skb);
 292	return 0;
 293}
 294
 295#if IS_ENABLED(CONFIG_IPV6_MIP6)
 296static void mip6_addr_swap(struct sk_buff *skb)
 297{
 298	struct ipv6hdr *iph = ipv6_hdr(skb);
 299	struct inet6_skb_parm *opt = IP6CB(skb);
 300	struct ipv6_destopt_hao *hao;
 301	struct in6_addr tmp;
 302	int off;
 303
 304	if (opt->dsthao) {
 305		off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
 306		if (likely(off >= 0)) {
 307			hao = (struct ipv6_destopt_hao *)
 308					(skb_network_header(skb) + off);
 309			tmp = iph->saddr;
 310			iph->saddr = hao->addr;
 311			hao->addr = tmp;
 312		}
 313	}
 314}
 315#else
 316static inline void mip6_addr_swap(struct sk_buff *skb) {}
 317#endif
 318
 319static struct dst_entry *icmpv6_route_lookup(struct net *net,
 320					     struct sk_buff *skb,
 321					     struct sock *sk,
 322					     struct flowi6 *fl6)
 323{
 324	struct dst_entry *dst, *dst2;
 325	struct flowi6 fl2;
 326	int err;
 327
 328	err = ip6_dst_lookup(sk, &dst, fl6);
 329	if (err)
 330		return ERR_PTR(err);
 331
 332	/*
 333	 * We won't send icmp if the destination is known
 334	 * anycast.
 335	 */
 336	if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) {
 337		LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: acast source\n");
 338		dst_release(dst);
 339		return ERR_PTR(-EINVAL);
 340	}
 341
 342	/* No need to clone since we're just using its address. */
 343	dst2 = dst;
 344
 345	dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0);
 346	if (!IS_ERR(dst)) {
 347		if (dst != dst2)
 348			return dst;
 349	} else {
 350		if (PTR_ERR(dst) == -EPERM)
 351			dst = NULL;
 352		else
 353			return dst;
 354	}
 355
 356	err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6);
 357	if (err)
 358		goto relookup_failed;
 359
 360	err = ip6_dst_lookup(sk, &dst2, &fl2);
 361	if (err)
 362		goto relookup_failed;
 363
 364	dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP);
 365	if (!IS_ERR(dst2)) {
 366		dst_release(dst);
 367		dst = dst2;
 368	} else {
 369		err = PTR_ERR(dst2);
 370		if (err == -EPERM) {
 371			dst_release(dst);
 372			return dst2;
 373		} else
 374			goto relookup_failed;
 375	}
 376
 377relookup_failed:
 378	if (dst)
 379		return dst;
 380	return ERR_PTR(err);
 381}
 382
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 383/*
 384 *	Send an ICMP message in response to a packet in error
 385 */
 386static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
 
 387{
 388	struct net *net = dev_net(skb->dev);
 389	struct inet6_dev *idev = NULL;
 390	struct ipv6hdr *hdr = ipv6_hdr(skb);
 391	struct sock *sk;
 
 392	struct ipv6_pinfo *np;
 393	const struct in6_addr *saddr = NULL;
 394	struct dst_entry *dst;
 395	struct icmp6hdr tmp_hdr;
 396	struct flowi6 fl6;
 397	struct icmpv6_msg msg;
 
 398	int iif = 0;
 399	int addr_type = 0;
 400	int len;
 401	int hlimit;
 402	int err = 0;
 403
 404	if ((u8 *)hdr < skb->head ||
 405	    (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb))
 406		return;
 407
 
 
 
 
 408	/*
 409	 *	Make sure we respect the rules
 410	 *	i.e. RFC 1885 2.4(e)
 411	 *	Rule (e.1) is enforced by not using icmp6_send
 412	 *	in any code that processes icmp errors.
 413	 */
 414	addr_type = ipv6_addr_type(&hdr->daddr);
 415
 416	if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) ||
 417	    ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr))
 418		saddr = &hdr->daddr;
 419
 420	/*
 421	 *	Dest addr check
 422	 */
 423
 424	if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) {
 425		if (type != ICMPV6_PKT_TOOBIG &&
 426		    !(type == ICMPV6_PARAMPROB &&
 427		      code == ICMPV6_UNK_OPTION &&
 428		      (opt_unrec(skb, info))))
 429			return;
 430
 431		saddr = NULL;
 432	}
 433
 434	addr_type = ipv6_addr_type(&hdr->saddr);
 435
 436	/*
 437	 *	Source addr check
 438	 */
 439
 440	if (__ipv6_addr_needs_scope_id(addr_type))
 441		iif = skb->dev->ifindex;
 
 
 
 
 442
 443	/*
 444	 *	Must not send error if the source does not uniquely
 445	 *	identify a single node (RFC2463 Section 2.4).
 446	 *	We check unspecified / multicast addresses here,
 447	 *	and anycast addresses will be checked later.
 448	 */
 449	if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) {
 450		LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: addr_any/mcast source\n");
 
 451		return;
 452	}
 453
 454	/*
 455	 *	Never answer to a ICMP packet.
 456	 */
 457	if (is_ineligible(skb)) {
 458		LIMIT_NETDEBUG(KERN_DEBUG "icmp6_send: no reply to icmp error\n");
 
 459		return;
 460	}
 461
 
 
 
 
 
 
 
 462	mip6_addr_swap(skb);
 463
 464	memset(&fl6, 0, sizeof(fl6));
 465	fl6.flowi6_proto = IPPROTO_ICMPV6;
 466	fl6.daddr = hdr->saddr;
 
 
 467	if (saddr)
 468		fl6.saddr = *saddr;
 
 469	fl6.flowi6_oif = iif;
 470	fl6.fl6_icmp_type = type;
 471	fl6.fl6_icmp_code = code;
 
 
 472	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 473
 474	sk = icmpv6_xmit_lock(net);
 475	if (sk == NULL)
 476		return;
 
 
 477	np = inet6_sk(sk);
 478
 479	if (!icmpv6_xrlim_allow(sk, type, &fl6))
 480		goto out;
 481
 482	tmp_hdr.icmp6_type = type;
 483	tmp_hdr.icmp6_code = code;
 484	tmp_hdr.icmp6_cksum = 0;
 485	tmp_hdr.icmp6_pointer = htonl(info);
 486
 487	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 488		fl6.flowi6_oif = np->mcast_oif;
 489	else if (!fl6.flowi6_oif)
 490		fl6.flowi6_oif = np->ucast_oif;
 491
 
 
 
 492	dst = icmpv6_route_lookup(net, skb, sk, &fl6);
 493	if (IS_ERR(dst))
 494		goto out;
 495
 496	if (ipv6_addr_is_multicast(&fl6.daddr))
 497		hlimit = np->mcast_hops;
 498	else
 499		hlimit = np->hop_limit;
 500	if (hlimit < 0)
 501		hlimit = ip6_dst_hoplimit(dst);
 502
 503	msg.skb = skb;
 504	msg.offset = skb_network_offset(skb);
 505	msg.type = type;
 506
 507	len = skb->len - msg.offset;
 508	len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr));
 509	if (len < 0) {
 510		LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n");
 
 511		goto out_dst_release;
 512	}
 513
 514	rcu_read_lock();
 515	idev = __in6_dev_get(skb->dev);
 516
 517	err = ip6_append_data(sk, icmpv6_getfrag, &msg,
 518			      len + sizeof(struct icmp6hdr),
 519			      sizeof(struct icmp6hdr), hlimit,
 520			      np->tclass, NULL, &fl6, (struct rt6_info *)dst,
 521			      MSG_DONTWAIT, np->dontfrag);
 522	if (err) {
 523		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
 524		ip6_flush_pending_frames(sk);
 525	} else {
 526		err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 527						 len + sizeof(struct icmp6hdr));
 528	}
 529	rcu_read_unlock();
 530out_dst_release:
 531	dst_release(dst);
 532out:
 533	icmpv6_xmit_unlock(sk);
 
 
 534}
 535
 536/* Slightly more convenient version of icmp6_send.
 537 */
 538void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
 539{
 540	icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
 541	kfree_skb(skb);
 542}
 543
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 544static void icmpv6_echo_reply(struct sk_buff *skb)
 545{
 546	struct net *net = dev_net(skb->dev);
 547	struct sock *sk;
 548	struct inet6_dev *idev;
 549	struct ipv6_pinfo *np;
 550	const struct in6_addr *saddr = NULL;
 551	struct icmp6hdr *icmph = icmp6_hdr(skb);
 552	struct icmp6hdr tmp_hdr;
 553	struct flowi6 fl6;
 554	struct icmpv6_msg msg;
 555	struct dst_entry *dst;
 556	int err = 0;
 557	int hlimit;
 558	u8 tclass;
 
 
 
 
 559
 560	saddr = &ipv6_hdr(skb)->daddr;
 561
 
 
 
 
 562	if (!ipv6_unicast_destination(skb) &&
 563	    !(net->ipv6.sysctl.anycast_src_echo_reply &&
 564	      ipv6_anycast_destination(skb)))
 565		saddr = NULL;
 566
 567	memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr));
 568	tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY;
 569
 570	memset(&fl6, 0, sizeof(fl6));
 
 
 
 571	fl6.flowi6_proto = IPPROTO_ICMPV6;
 572	fl6.daddr = ipv6_hdr(skb)->saddr;
 573	if (saddr)
 574		fl6.saddr = *saddr;
 575	fl6.flowi6_oif = skb->dev->ifindex;
 576	fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
 
 
 577	security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));
 578
 
 579	sk = icmpv6_xmit_lock(net);
 580	if (sk == NULL)
 581		return;
 
 582	np = inet6_sk(sk);
 583
 584	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 585		fl6.flowi6_oif = np->mcast_oif;
 586	else if (!fl6.flowi6_oif)
 587		fl6.flowi6_oif = np->ucast_oif;
 588
 589	err = ip6_dst_lookup(sk, &dst, &fl6);
 590	if (err)
 591		goto out;
 592	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
 593	if (IS_ERR(dst))
 594		goto out;
 595
 596	if (ipv6_addr_is_multicast(&fl6.daddr))
 597		hlimit = np->mcast_hops;
 598	else
 599		hlimit = np->hop_limit;
 600	if (hlimit < 0)
 601		hlimit = ip6_dst_hoplimit(dst);
 602
 603	idev = __in6_dev_get(skb->dev);
 604
 605	msg.skb = skb;
 606	msg.offset = 0;
 607	msg.type = ICMPV6_ECHO_REPLY;
 608
 609	tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 610	err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
 611				sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl6,
 612				(struct rt6_info *)dst, MSG_DONTWAIT,
 613				np->dontfrag);
 614
 615	if (err) {
 616		ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
 
 617		ip6_flush_pending_frames(sk);
 618	} else {
 619		err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
 620						 skb->len + sizeof(struct icmp6hdr));
 621	}
 
 622	dst_release(dst);
 623out:
 624	icmpv6_xmit_unlock(sk);
 
 
 625}
 626
 627void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info)
 628{
 629	const struct inet6_protocol *ipprot;
 630	int inner_offset;
 631	__be16 frag_off;
 632	u8 nexthdr;
 
 633
 634	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 635		return;
 636
 637	nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr;
 638	if (ipv6_ext_hdr(nexthdr)) {
 639		/* now skip over extension headers */
 640		inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
 641						&nexthdr, &frag_off);
 642		if (inner_offset<0)
 643			return;
 644	} else {
 645		inner_offset = sizeof(struct ipv6hdr);
 646	}
 647
 648	/* Checkin header including 8 bytes of inner protocol header. */
 649	if (!pskb_may_pull(skb, inner_offset+8))
 650		return;
 651
 652	/* BUGGG_FUTURE: we should try to parse exthdrs in this packet.
 653	   Without this we will not able f.e. to make source routed
 654	   pmtu discovery.
 655	   Corresponding argument (opt) to notifiers is already added.
 656	   --ANK (980726)
 657	 */
 658
 659	rcu_read_lock();
 660	ipprot = rcu_dereference(inet6_protos[nexthdr]);
 661	if (ipprot && ipprot->err_handler)
 662		ipprot->err_handler(skb, NULL, type, code, inner_offset, info);
 663	rcu_read_unlock();
 664
 665	raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info);
 
 
 
 
 666}
 667
 668/*
 669 *	Handle icmp messages
 670 */
 671
 672static int icmpv6_rcv(struct sk_buff *skb)
 673{
 674	struct net_device *dev = skb->dev;
 
 675	struct inet6_dev *idev = __in6_dev_get(dev);
 676	const struct in6_addr *saddr, *daddr;
 677	struct icmp6hdr *hdr;
 678	u8 type;
 
 679
 680	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 681		struct sec_path *sp = skb_sec_path(skb);
 682		int nh;
 683
 684		if (!(sp && sp->xvec[sp->len - 1]->props.flags &
 685				 XFRM_STATE_ICMP))
 686			goto drop_no_count;
 687
 688		if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr)))
 689			goto drop_no_count;
 690
 691		nh = skb_network_offset(skb);
 692		skb_set_network_header(skb, sizeof(*hdr));
 693
 694		if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
 695			goto drop_no_count;
 696
 697		skb_set_network_header(skb, nh);
 698	}
 699
 700	ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS);
 701
 702	saddr = &ipv6_hdr(skb)->saddr;
 703	daddr = &ipv6_hdr(skb)->daddr;
 704
 705	/* Perform checksum. */
 706	switch (skb->ip_summed) {
 707	case CHECKSUM_COMPLETE:
 708		if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6,
 709				     skb->csum))
 710			break;
 711		/* fall through */
 712	case CHECKSUM_NONE:
 713		skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len,
 714					     IPPROTO_ICMPV6, 0));
 715		if (__skb_checksum_complete(skb)) {
 716			LIMIT_NETDEBUG(KERN_DEBUG
 717				       "ICMPv6 checksum failed [%pI6c > %pI6c]\n",
 718				       saddr, daddr);
 719			goto csum_error;
 720		}
 721	}
 722
 723	if (!pskb_pull(skb, sizeof(*hdr)))
 724		goto discard_it;
 725
 726	hdr = icmp6_hdr(skb);
 727
 728	type = hdr->icmp6_type;
 729
 730	ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type);
 731
 732	switch (type) {
 733	case ICMPV6_ECHO_REQUEST:
 734		icmpv6_echo_reply(skb);
 
 735		break;
 736
 737	case ICMPV6_ECHO_REPLY:
 738		ping_rcv(skb);
 739		break;
 740
 741	case ICMPV6_PKT_TOOBIG:
 742		/* BUGGG_FUTURE: if packet contains rthdr, we cannot update
 743		   standard destination cache. Seems, only "advanced"
 744		   destination cache will allow to solve this problem
 745		   --ANK (980726)
 746		 */
 747		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 748			goto discard_it;
 749		hdr = icmp6_hdr(skb);
 750
 751		/*
 752		 *	Drop through to notify
 753		 */
 754
 755	case ICMPV6_DEST_UNREACH:
 756	case ICMPV6_TIME_EXCEED:
 757	case ICMPV6_PARAMPROB:
 758		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 759		break;
 760
 761	case NDISC_ROUTER_SOLICITATION:
 762	case NDISC_ROUTER_ADVERTISEMENT:
 763	case NDISC_NEIGHBOUR_SOLICITATION:
 764	case NDISC_NEIGHBOUR_ADVERTISEMENT:
 765	case NDISC_REDIRECT:
 766		ndisc_rcv(skb);
 767		break;
 768
 769	case ICMPV6_MGM_QUERY:
 770		igmp6_event_query(skb);
 771		break;
 772
 773	case ICMPV6_MGM_REPORT:
 774		igmp6_event_report(skb);
 775		break;
 776
 777	case ICMPV6_MGM_REDUCTION:
 778	case ICMPV6_NI_QUERY:
 779	case ICMPV6_NI_REPLY:
 780	case ICMPV6_MLD2_REPORT:
 781	case ICMPV6_DHAAD_REQUEST:
 782	case ICMPV6_DHAAD_REPLY:
 783	case ICMPV6_MOBILE_PREFIX_SOL:
 784	case ICMPV6_MOBILE_PREFIX_ADV:
 785		break;
 786
 787	default:
 788		LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n");
 789
 790		/* informational */
 791		if (type & ICMPV6_INFOMSG_MASK)
 792			break;
 793
 
 
 
 794		/*
 795		 * error of unknown type.
 796		 * must pass to upper level
 797		 */
 798
 799		icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu);
 800	}
 801
 802	kfree_skb(skb);
 
 
 
 
 
 
 
 803	return 0;
 804
 805csum_error:
 806	ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS);
 807discard_it:
 808	ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS);
 809drop_no_count:
 810	kfree_skb(skb);
 811	return 0;
 812}
 813
 814void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
 815		      u8 type,
 816		      const struct in6_addr *saddr,
 817		      const struct in6_addr *daddr,
 818		      int oif)
 819{
 820	memset(fl6, 0, sizeof(*fl6));
 821	fl6->saddr = *saddr;
 822	fl6->daddr = *daddr;
 823	fl6->flowi6_proto 	= IPPROTO_ICMPV6;
 824	fl6->fl6_icmp_type	= type;
 825	fl6->fl6_icmp_code	= 0;
 826	fl6->flowi6_oif		= oif;
 827	security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 828}
 829
 830/*
 831 * Special lock-class for __icmpv6_sk:
 832 */
 833static struct lock_class_key icmpv6_socket_sk_dst_lock_key;
 
 
 
 
 834
 835static int __net_init icmpv6_sk_init(struct net *net)
 836{
 837	struct sock *sk;
 838	int err, i, j;
 839
 840	net->ipv6.icmp_sk =
 841		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
 842	if (net->ipv6.icmp_sk == NULL)
 843		return -ENOMEM;
 844
 845	for_each_possible_cpu(i) {
 846		err = inet_ctl_sock_create(&sk, PF_INET6,
 847					   SOCK_RAW, IPPROTO_ICMPV6, net);
 848		if (err < 0) {
 849			pr_err("Failed to initialize the ICMP6 control socket (err %d)\n",
 850			       err);
 851			goto fail;
 852		}
 853
 854		net->ipv6.icmp_sk[i] = sk;
 855
 856		/*
 857		 * Split off their lock-class, because sk->sk_dst_lock
 858		 * gets used from softirqs, which is safe for
 859		 * __icmpv6_sk (because those never get directly used
 860		 * via userspace syscalls), but unsafe for normal sockets.
 861		 */
 862		lockdep_set_class(&sk->sk_dst_lock,
 863				  &icmpv6_socket_sk_dst_lock_key);
 864
 865		/* Enough space for 2 64K ICMP packets, including
 866		 * sk_buff struct overhead.
 867		 */
 868		sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
 869	}
 870	return 0;
 871
 872 fail:
 873	for (j = 0; j < i; j++)
 874		inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]);
 875	kfree(net->ipv6.icmp_sk);
 876	return err;
 877}
 878
 879static void __net_exit icmpv6_sk_exit(struct net *net)
 880{
 881	int i;
 882
 883	for_each_possible_cpu(i) {
 884		inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]);
 885	}
 886	kfree(net->ipv6.icmp_sk);
 887}
 888
 889static struct pernet_operations icmpv6_sk_ops = {
 890       .init = icmpv6_sk_init,
 891       .exit = icmpv6_sk_exit,
 892};
 893
 894int __init icmpv6_init(void)
 895{
 896	int err;
 897
 898	err = register_pernet_subsys(&icmpv6_sk_ops);
 899	if (err < 0)
 900		return err;
 901
 902	err = -EAGAIN;
 903	if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
 904		goto fail;
 905
 906	err = inet6_register_icmp_sender(icmp6_send);
 907	if (err)
 908		goto sender_reg_err;
 909	return 0;
 910
 911sender_reg_err:
 912	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 913fail:
 914	pr_err("Failed to register ICMP6 protocol\n");
 915	unregister_pernet_subsys(&icmpv6_sk_ops);
 916	return err;
 917}
 918
 919void icmpv6_cleanup(void)
 920{
 921	inet6_unregister_icmp_sender(icmp6_send);
 922	unregister_pernet_subsys(&icmpv6_sk_ops);
 923	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 924}
 925
 926
 927static const struct icmp6_err {
 928	int err;
 929	int fatal;
 930} tab_unreach[] = {
 931	{	/* NOROUTE */
 932		.err	= ENETUNREACH,
 933		.fatal	= 0,
 934	},
 935	{	/* ADM_PROHIBITED */
 936		.err	= EACCES,
 937		.fatal	= 1,
 938	},
 939	{	/* Was NOT_NEIGHBOUR, now reserved */
 940		.err	= EHOSTUNREACH,
 941		.fatal	= 0,
 942	},
 943	{	/* ADDR_UNREACH	*/
 944		.err	= EHOSTUNREACH,
 945		.fatal	= 0,
 946	},
 947	{	/* PORT_UNREACH	*/
 948		.err	= ECONNREFUSED,
 949		.fatal	= 1,
 950	},
 951	{	/* POLICY_FAIL */
 952		.err	= EACCES,
 953		.fatal	= 1,
 954	},
 955	{	/* REJECT_ROUTE	*/
 956		.err	= EACCES,
 957		.fatal	= 1,
 958	},
 959};
 960
 961int icmpv6_err_convert(u8 type, u8 code, int *err)
 962{
 963	int fatal = 0;
 964
 965	*err = EPROTO;
 966
 967	switch (type) {
 968	case ICMPV6_DEST_UNREACH:
 969		fatal = 1;
 970		if (code < ARRAY_SIZE(tab_unreach)) {
 971			*err  = tab_unreach[code].err;
 972			fatal = tab_unreach[code].fatal;
 973		}
 974		break;
 975
 976	case ICMPV6_PKT_TOOBIG:
 977		*err = EMSGSIZE;
 978		break;
 979
 980	case ICMPV6_PARAMPROB:
 981		*err = EPROTO;
 982		fatal = 1;
 983		break;
 984
 985	case ICMPV6_TIME_EXCEED:
 986		*err = EHOSTUNREACH;
 987		break;
 988	}
 989
 990	return fatal;
 991}
 992EXPORT_SYMBOL(icmpv6_err_convert);
 993
 994#ifdef CONFIG_SYSCTL
 995static struct ctl_table ipv6_icmp_table_template[] = {
 996	{
 997		.procname	= "ratelimit",
 998		.data		= &init_net.ipv6.sysctl.icmpv6_time,
 999		.maxlen		= sizeof(int),
1000		.mode		= 0644,
1001		.proc_handler	= proc_dointvec_ms_jiffies,
1002	},
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1003	{ },
1004};
1005
1006struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
1007{
1008	struct ctl_table *table;
1009
1010	table = kmemdup(ipv6_icmp_table_template,
1011			sizeof(ipv6_icmp_table_template),
1012			GFP_KERNEL);
1013
1014	if (table)
1015		table[0].data = &net->ipv6.sysctl.icmpv6_time;
1016
 
 
 
 
1017	return table;
1018}
1019#endif
1020
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