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v3.1
 
   1/*
   2 *	Neighbour Discovery for IPv6
   3 *	Linux INET6 implementation
   4 *
   5 *	Authors:
   6 *	Pedro Roque		<roque@di.fc.ul.pt>
   7 *	Mike Shaver		<shaver@ingenia.com>
   8 *
   9 *	This program is free software; you can redistribute it and/or
  10 *      modify it under the terms of the GNU General Public License
  11 *      as published by the Free Software Foundation; either version
  12 *      2 of the License, or (at your option) any later version.
  13 */
  14
  15/*
  16 *	Changes:
  17 *
 
  18 *	Pierre Ynard			:	export userland ND options
  19 *						through netlink (RDNSS support)
  20 *	Lars Fenneberg			:	fixed MTU setting on receipt
  21 *						of an RA.
  22 *	Janos Farkas			:	kmalloc failure checks
  23 *	Alexey Kuznetsov		:	state machine reworked
  24 *						and moved to net/core.
  25 *	Pekka Savola			:	RFC2461 validation
  26 *	YOSHIFUJI Hideaki @USAGI	:	Verify ND options properly
  27 */
  28
  29/* Set to 3 to get tracing... */
  30#define ND_DEBUG 1
  31
  32#define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
  33#define ND_NOPRINTK(x...) do { ; } while(0)
  34#define ND_PRINTK0 ND_PRINTK
  35#define ND_PRINTK1 ND_NOPRINTK
  36#define ND_PRINTK2 ND_NOPRINTK
  37#define ND_PRINTK3 ND_NOPRINTK
  38#if ND_DEBUG >= 1
  39#undef ND_PRINTK1
  40#define ND_PRINTK1 ND_PRINTK
  41#endif
  42#if ND_DEBUG >= 2
  43#undef ND_PRINTK2
  44#define ND_PRINTK2 ND_PRINTK
  45#endif
  46#if ND_DEBUG >= 3
  47#undef ND_PRINTK3
  48#define ND_PRINTK3 ND_PRINTK
  49#endif
  50
  51#include <linux/module.h>
  52#include <linux/errno.h>
  53#include <linux/types.h>
  54#include <linux/socket.h>
  55#include <linux/sockios.h>
  56#include <linux/sched.h>
  57#include <linux/net.h>
  58#include <linux/in6.h>
  59#include <linux/route.h>
  60#include <linux/init.h>
  61#include <linux/rcupdate.h>
  62#include <linux/slab.h>
  63#ifdef CONFIG_SYSCTL
  64#include <linux/sysctl.h>
  65#endif
  66
  67#include <linux/if_addr.h>
 
  68#include <linux/if_arp.h>
  69#include <linux/ipv6.h>
  70#include <linux/icmpv6.h>
  71#include <linux/jhash.h>
  72
  73#include <net/sock.h>
  74#include <net/snmp.h>
  75
  76#include <net/ipv6.h>
  77#include <net/protocol.h>
  78#include <net/ndisc.h>
  79#include <net/ip6_route.h>
  80#include <net/addrconf.h>
  81#include <net/icmp.h>
  82
  83#include <net/netlink.h>
  84#include <linux/rtnetlink.h>
  85
  86#include <net/flow.h>
  87#include <net/ip6_checksum.h>
  88#include <net/inet_common.h>
  89#include <linux/proc_fs.h>
  90
  91#include <linux/netfilter.h>
  92#include <linux/netfilter_ipv6.h>
  93
  94static u32 ndisc_hash(const void *pkey,
  95		      const struct net_device *dev,
  96		      __u32 rnd);
 
 
 
  97static int ndisc_constructor(struct neighbour *neigh);
  98static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  99static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
 100static int pndisc_constructor(struct pneigh_entry *n);
 101static void pndisc_destructor(struct pneigh_entry *n);
 102static void pndisc_redo(struct sk_buff *skb);
 103
 104static const struct neigh_ops ndisc_generic_ops = {
 105	.family =		AF_INET6,
 106	.solicit =		ndisc_solicit,
 107	.error_report =		ndisc_error_report,
 108	.output =		neigh_resolve_output,
 109	.connected_output =	neigh_connected_output,
 110};
 111
 112static const struct neigh_ops ndisc_hh_ops = {
 113	.family =		AF_INET6,
 114	.solicit =		ndisc_solicit,
 115	.error_report =		ndisc_error_report,
 116	.output =		neigh_resolve_output,
 117	.connected_output =	neigh_resolve_output,
 118};
 119
 120
 121static const struct neigh_ops ndisc_direct_ops = {
 122	.family =		AF_INET6,
 123	.output =		neigh_direct_output,
 124	.connected_output =	neigh_direct_output,
 125};
 126
 127struct neigh_table nd_tbl = {
 128	.family =	AF_INET6,
 129	.entry_size =	sizeof(struct neighbour) + sizeof(struct in6_addr),
 130	.key_len =	sizeof(struct in6_addr),
 
 131	.hash =		ndisc_hash,
 
 132	.constructor =	ndisc_constructor,
 133	.pconstructor =	pndisc_constructor,
 134	.pdestructor =	pndisc_destructor,
 135	.proxy_redo =	pndisc_redo,
 
 136	.id =		"ndisc_cache",
 137	.parms = {
 138		.tbl			= &nd_tbl,
 139		.base_reachable_time	= ND_REACHABLE_TIME,
 140		.retrans_time		= ND_RETRANS_TIMER,
 141		.gc_staletime		= 60 * HZ,
 142		.reachable_time		= ND_REACHABLE_TIME,
 143		.delay_probe_time	= 5 * HZ,
 144		.queue_len		= 3,
 145		.ucast_probes		= 3,
 146		.mcast_probes		= 3,
 147		.anycast_delay		= 1 * HZ,
 148		.proxy_delay		= (8 * HZ) / 10,
 149		.proxy_qlen		= 64,
 
 
 
 
 
 150	},
 151	.gc_interval =	  30 * HZ,
 152	.gc_thresh1 =	 128,
 153	.gc_thresh2 =	 512,
 154	.gc_thresh3 =	1024,
 155};
 
 156
 157/* ND options */
 158struct ndisc_options {
 159	struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 160#ifdef CONFIG_IPV6_ROUTE_INFO
 161	struct nd_opt_hdr *nd_opts_ri;
 162	struct nd_opt_hdr *nd_opts_ri_end;
 163#endif
 164	struct nd_opt_hdr *nd_useropts;
 165	struct nd_opt_hdr *nd_useropts_end;
 166};
 167
 168#define nd_opts_src_lladdr	nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
 169#define nd_opts_tgt_lladdr	nd_opt_array[ND_OPT_TARGET_LL_ADDR]
 170#define nd_opts_pi		nd_opt_array[ND_OPT_PREFIX_INFO]
 171#define nd_opts_pi_end		nd_opt_array[__ND_OPT_PREFIX_INFO_END]
 172#define nd_opts_rh		nd_opt_array[ND_OPT_REDIRECT_HDR]
 173#define nd_opts_mtu		nd_opt_array[ND_OPT_MTU]
 174
 175#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
 176
 177/*
 178 * Return the padding between the option length and the start of the
 179 * link addr.  Currently only IP-over-InfiniBand needs this, although
 180 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 181 * also need a pad of 2.
 182 */
 183static int ndisc_addr_option_pad(unsigned short type)
 184{
 185	switch (type) {
 186	case ARPHRD_INFINIBAND: return 2;
 187	default:                return 0;
 188	}
 189}
 190
 191static inline int ndisc_opt_addr_space(struct net_device *dev)
 192{
 193	return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
 194}
 195
 196static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
 197				  unsigned short addr_type)
 198{
 199	int space = NDISC_OPT_SPACE(data_len);
 200	int pad   = ndisc_addr_option_pad(addr_type);
 201
 202	opt[0] = type;
 203	opt[1] = space>>3;
 204
 205	memset(opt + 2, 0, pad);
 206	opt   += pad;
 207	space -= pad;
 208
 209	memcpy(opt+2, data, data_len);
 210	data_len += 2;
 211	opt += data_len;
 212	if ((space -= data_len) > 0)
 
 213		memset(opt, 0, space);
 214	return opt + space;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 215}
 216
 217static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 218					    struct nd_opt_hdr *end)
 219{
 220	int type;
 221	if (!cur || !end || cur >= end)
 222		return NULL;
 223	type = cur->nd_opt_type;
 224	do {
 225		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 226	} while(cur < end && cur->nd_opt_type != type);
 227	return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 228}
 229
 230static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
 
 231{
 232	return opt->nd_opt_type == ND_OPT_RDNSS;
 
 
 
 
 233}
 234
 235static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
 
 236					     struct nd_opt_hdr *end)
 237{
 238	if (!cur || !end || cur >= end)
 239		return NULL;
 240	do {
 241		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 242	} while(cur < end && !ndisc_is_useropt(cur));
 243	return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
 244}
 245
 246static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 247						 struct ndisc_options *ndopts)
 
 248{
 249	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 250
 251	if (!nd_opt || opt_len < 0 || !ndopts)
 252		return NULL;
 253	memset(ndopts, 0, sizeof(*ndopts));
 254	while (opt_len) {
 255		int l;
 256		if (opt_len < sizeof(struct nd_opt_hdr))
 257			return NULL;
 258		l = nd_opt->nd_opt_len << 3;
 259		if (opt_len < l || l == 0)
 260			return NULL;
 
 
 261		switch (nd_opt->nd_opt_type) {
 262		case ND_OPT_SOURCE_LL_ADDR:
 263		case ND_OPT_TARGET_LL_ADDR:
 264		case ND_OPT_MTU:
 
 265		case ND_OPT_REDIRECT_HDR:
 266			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 267				ND_PRINTK2(KERN_WARNING
 268					   "%s(): duplicated ND6 option found: type=%d\n",
 269					   __func__,
 270					   nd_opt->nd_opt_type);
 271			} else {
 272				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 273			}
 274			break;
 275		case ND_OPT_PREFIX_INFO:
 276			ndopts->nd_opts_pi_end = nd_opt;
 277			if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 278				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 279			break;
 280#ifdef CONFIG_IPV6_ROUTE_INFO
 281		case ND_OPT_ROUTE_INFO:
 282			ndopts->nd_opts_ri_end = nd_opt;
 283			if (!ndopts->nd_opts_ri)
 284				ndopts->nd_opts_ri = nd_opt;
 285			break;
 286#endif
 287		default:
 288			if (ndisc_is_useropt(nd_opt)) {
 289				ndopts->nd_useropts_end = nd_opt;
 290				if (!ndopts->nd_useropts)
 291					ndopts->nd_useropts = nd_opt;
 292			} else {
 293				/*
 294				 * Unknown options must be silently ignored,
 295				 * to accommodate future extension to the
 296				 * protocol.
 297				 */
 298				ND_PRINTK2(KERN_NOTICE
 299					   "%s(): ignored unsupported option; type=%d, len=%d\n",
 300					   __func__,
 301					   nd_opt->nd_opt_type, nd_opt->nd_opt_len);
 
 302			}
 303		}
 
 304		opt_len -= l;
 305		nd_opt = ((void *)nd_opt) + l;
 306	}
 307	return ndopts;
 308}
 309
 310static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 311				      struct net_device *dev)
 312{
 313	u8 *lladdr = (u8 *)(p + 1);
 314	int lladdrlen = p->nd_opt_len << 3;
 315	int prepad = ndisc_addr_option_pad(dev->type);
 316	if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
 317		return NULL;
 318	return lladdr + prepad;
 319}
 320
 321int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 322{
 323	switch (dev->type) {
 324	case ARPHRD_ETHER:
 325	case ARPHRD_IEEE802:	/* Not sure. Check it later. --ANK */
 326	case ARPHRD_FDDI:
 327		ipv6_eth_mc_map(addr, buf);
 328		return 0;
 329	case ARPHRD_IEEE802_TR:
 330		ipv6_tr_mc_map(addr,buf);
 331		return 0;
 332	case ARPHRD_ARCNET:
 333		ipv6_arcnet_mc_map(addr, buf);
 334		return 0;
 335	case ARPHRD_INFINIBAND:
 336		ipv6_ib_mc_map(addr, dev->broadcast, buf);
 337		return 0;
 338	case ARPHRD_IPGRE:
 339		return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 340	default:
 341		if (dir) {
 342			memcpy(buf, dev->broadcast, dev->addr_len);
 343			return 0;
 344		}
 345	}
 346	return -EINVAL;
 347}
 348
 349EXPORT_SYMBOL(ndisc_mc_map);
 350
 351static u32 ndisc_hash(const void *pkey,
 352		      const struct net_device *dev,
 353		      __u32 hash_rnd)
 354{
 355	const u32 *p32 = pkey;
 356	u32 addr_hash, i;
 357
 358	addr_hash = 0;
 359	for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
 360		addr_hash ^= *p32++;
 361
 362	return jhash_2words(addr_hash, dev->ifindex, hash_rnd);
 
 
 363}
 364
 365static int ndisc_constructor(struct neighbour *neigh)
 366{
 367	struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
 368	struct net_device *dev = neigh->dev;
 369	struct inet6_dev *in6_dev;
 370	struct neigh_parms *parms;
 371	int is_multicast = ipv6_addr_is_multicast(addr);
 372
 373	rcu_read_lock();
 374	in6_dev = in6_dev_get(dev);
 375	if (in6_dev == NULL) {
 376		rcu_read_unlock();
 377		return -EINVAL;
 378	}
 379
 380	parms = in6_dev->nd_parms;
 381	__neigh_parms_put(neigh->parms);
 382	neigh->parms = neigh_parms_clone(parms);
 383	rcu_read_unlock();
 384
 385	neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 386	if (!dev->header_ops) {
 387		neigh->nud_state = NUD_NOARP;
 388		neigh->ops = &ndisc_direct_ops;
 389		neigh->output = neigh_direct_output;
 390	} else {
 391		if (is_multicast) {
 392			neigh->nud_state = NUD_NOARP;
 393			ndisc_mc_map(addr, neigh->ha, dev, 1);
 394		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 395			neigh->nud_state = NUD_NOARP;
 396			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 397			if (dev->flags&IFF_LOOPBACK)
 398				neigh->type = RTN_LOCAL;
 399		} else if (dev->flags&IFF_POINTOPOINT) {
 400			neigh->nud_state = NUD_NOARP;
 401			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 402		}
 403		if (dev->header_ops->cache)
 404			neigh->ops = &ndisc_hh_ops;
 405		else
 406			neigh->ops = &ndisc_generic_ops;
 407		if (neigh->nud_state&NUD_VALID)
 408			neigh->output = neigh->ops->connected_output;
 409		else
 410			neigh->output = neigh->ops->output;
 411	}
 412	in6_dev_put(in6_dev);
 413	return 0;
 414}
 415
 416static int pndisc_constructor(struct pneigh_entry *n)
 417{
 418	struct in6_addr *addr = (struct in6_addr*)&n->key;
 419	struct in6_addr maddr;
 420	struct net_device *dev = n->dev;
 421
 422	if (dev == NULL || __in6_dev_get(dev) == NULL)
 423		return -EINVAL;
 424	addrconf_addr_solict_mult(addr, &maddr);
 425	ipv6_dev_mc_inc(dev, &maddr);
 426	return 0;
 427}
 428
 429static void pndisc_destructor(struct pneigh_entry *n)
 430{
 431	struct in6_addr *addr = (struct in6_addr*)&n->key;
 432	struct in6_addr maddr;
 433	struct net_device *dev = n->dev;
 434
 435	if (dev == NULL || __in6_dev_get(dev) == NULL)
 436		return;
 437	addrconf_addr_solict_mult(addr, &maddr);
 438	ipv6_dev_mc_dec(dev, &maddr);
 439}
 440
 441struct sk_buff *ndisc_build_skb(struct net_device *dev,
 442				const struct in6_addr *daddr,
 443				const struct in6_addr *saddr,
 444				struct icmp6hdr *icmp6h,
 445				const struct in6_addr *target,
 446				int llinfo)
 447{
 448	struct net *net = dev_net(dev);
 449	struct sock *sk = net->ipv6.ndisc_sk;
 450	struct sk_buff *skb;
 451	struct icmp6hdr *hdr;
 452	int len;
 453	int err;
 454	u8 *opt;
 455
 456	if (!dev->addr_len)
 457		llinfo = 0;
 
 
 458
 459	len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
 460	if (llinfo)
 461		len += ndisc_opt_addr_space(dev);
 462
 463	skb = sock_alloc_send_skb(sk,
 464				  (MAX_HEADER + sizeof(struct ipv6hdr) +
 465				   len + LL_ALLOCATED_SPACE(dev)),
 466				  1, &err);
 
 
 
 
 467	if (!skb) {
 468		ND_PRINTK0(KERN_ERR
 469			   "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
 470			   __func__, err);
 471		return NULL;
 472	}
 473
 474	skb_reserve(skb, LL_RESERVED_SPACE(dev));
 475	ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 476
 477	skb->transport_header = skb->tail;
 478	skb_put(skb, len);
 479
 480	hdr = (struct icmp6hdr *)skb_transport_header(skb);
 481	memcpy(hdr, icmp6h, sizeof(*hdr));
 
 
 482
 483	opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
 484	if (target) {
 485		ipv6_addr_copy((struct in6_addr *)opt, target);
 486		opt += sizeof(*target);
 487	}
 488
 489	if (llinfo)
 490		ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
 491				       dev->addr_len, dev->type);
 
 
 
 
 
 492
 493	hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
 494					   IPPROTO_ICMPV6,
 495					   csum_partial(hdr,
 496							len, 0));
 497
 498	return skb;
 499}
 
 
 
 500
 501EXPORT_SYMBOL(ndisc_build_skb);
 
 
 
 
 
 
 502
 503void ndisc_send_skb(struct sk_buff *skb,
 504		    struct net_device *dev,
 505		    struct neighbour *neigh,
 506		    const struct in6_addr *daddr,
 507		    const struct in6_addr *saddr,
 508		    struct icmp6hdr *icmp6h)
 509{
 510	struct flowi6 fl6;
 511	struct dst_entry *dst;
 512	struct net *net = dev_net(dev);
 513	struct sock *sk = net->ipv6.ndisc_sk;
 514	struct inet6_dev *idev;
 515	int err;
 
 516	u8 type;
 517
 518	type = icmp6h->icmp6_type;
 519
 520	icmpv6_flow_init(sk, &fl6, type, saddr, daddr, dev->ifindex);
 521
 522	dst = icmp6_dst_alloc(dev, neigh, daddr);
 523	if (!dst) {
 524		kfree_skb(skb);
 525		return;
 526	}
 527
 528	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
 529	if (IS_ERR(dst)) {
 530		kfree_skb(skb);
 531		return;
 
 
 
 
 532	}
 533
 534	skb_dst_set(skb, dst);
 
 
 
 535
 536	idev = in6_dev_get(dst->dev);
 
 
 
 537	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 538
 539	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
 
 540		      dst_output);
 541	if (!err) {
 542		ICMP6MSGOUT_INC_STATS(net, idev, type);
 543		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 544	}
 545
 546	if (likely(idev != NULL))
 547		in6_dev_put(idev);
 548}
 549
 550EXPORT_SYMBOL(ndisc_send_skb);
 551
 552/*
 553 *	Send a Neighbour Discover packet
 554 */
 555static void __ndisc_send(struct net_device *dev,
 556			 struct neighbour *neigh,
 557			 const struct in6_addr *daddr,
 558			 const struct in6_addr *saddr,
 559			 struct icmp6hdr *icmp6h, const struct in6_addr *target,
 560			 int llinfo)
 561{
 562	struct sk_buff *skb;
 563
 564	skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo);
 565	if (!skb)
 566		return;
 567
 568	ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h);
 569}
 570
 571static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
 572			  const struct in6_addr *daddr,
 573			  const struct in6_addr *solicited_addr,
 574			  int router, int solicited, int override, int inc_opt)
 575{
 576	struct in6_addr tmpaddr;
 577	struct inet6_ifaddr *ifp;
 578	const struct in6_addr *src_addr;
 579	struct icmp6hdr icmp6h = {
 580		.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 581	};
 582
 583	/* for anycast or proxy, solicited_addr != src_addr */
 584	ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 585	if (ifp) {
 586		src_addr = solicited_addr;
 587		if (ifp->flags & IFA_F_OPTIMISTIC)
 588			override = 0;
 589		inc_opt |= ifp->idev->cnf.force_tllao;
 590		in6_ifa_put(ifp);
 591	} else {
 592		if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 593				       inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 594				       &tmpaddr))
 595			return;
 596		src_addr = &tmpaddr;
 597	}
 598
 599	icmp6h.icmp6_router = router;
 600	icmp6h.icmp6_solicited = solicited;
 601	icmp6h.icmp6_override = override;
 602
 603	__ndisc_send(dev, neigh, daddr, src_addr,
 604		     &icmp6h, solicited_addr,
 605		     inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 606}
 607
 608static void ndisc_send_unsol_na(struct net_device *dev)
 609{
 610	struct inet6_dev *idev;
 611	struct inet6_ifaddr *ifa;
 612	struct in6_addr mcaddr;
 613
 614	idev = in6_dev_get(dev);
 615	if (!idev)
 616		return;
 617
 618	read_lock_bh(&idev->lock);
 619	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 620		addrconf_addr_solict_mult(&ifa->addr, &mcaddr);
 621		ndisc_send_na(dev, NULL, &mcaddr, &ifa->addr,
 
 
 
 
 622			      /*router=*/ !!idev->cnf.forwarding,
 623			      /*solicited=*/ false, /*override=*/ true,
 624			      /*inc_opt=*/ true);
 625	}
 626	read_unlock_bh(&idev->lock);
 627
 628	in6_dev_put(idev);
 629}
 630
 631void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 632		   const struct in6_addr *solicit,
 633		   const struct in6_addr *daddr, const struct in6_addr *saddr)
 634{
 
 635	struct in6_addr addr_buf;
 636	struct icmp6hdr icmp6h = {
 637		.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 638	};
 639
 640	if (saddr == NULL) {
 641		if (ipv6_get_lladdr(dev, &addr_buf,
 642				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 643			return;
 644		saddr = &addr_buf;
 645	}
 646
 647	__ndisc_send(dev, neigh, daddr, saddr,
 648		     &icmp6h, solicit,
 649		     !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 650}
 651
 652void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 653		   const struct in6_addr *daddr)
 654{
 655	struct icmp6hdr icmp6h = {
 656		.icmp6_type = NDISC_ROUTER_SOLICITATION,
 657	};
 658	int send_sllao = dev->addr_len;
 
 659
 660#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 661	/*
 662	 * According to section 2.2 of RFC 4429, we must not
 663	 * send router solicitations with a sllao from
 664	 * optimistic addresses, but we may send the solicitation
 665	 * if we don't include the sllao.  So here we check
 666	 * if our address is optimistic, and if so, we
 667	 * suppress the inclusion of the sllao.
 668	 */
 669	if (send_sllao) {
 670		struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 671							   dev, 1);
 672		if (ifp) {
 673			if (ifp->flags & IFA_F_OPTIMISTIC)  {
 674				send_sllao = 0;
 675			}
 676			in6_ifa_put(ifp);
 677		} else {
 678			send_sllao = 0;
 679		}
 680	}
 681#endif
 682	__ndisc_send(dev, NULL, daddr, saddr,
 683		     &icmp6h, NULL,
 684		     send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 685}
 686
 687
 688static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 689{
 690	/*
 691	 *	"The sender MUST return an ICMP
 692	 *	 destination unreachable"
 693	 */
 694	dst_link_failure(skb);
 695	kfree_skb(skb);
 696}
 697
 698/* Called with locked neigh: either read or both */
 699
 700static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 701{
 702	struct in6_addr *saddr = NULL;
 703	struct in6_addr mcaddr;
 704	struct net_device *dev = neigh->dev;
 705	struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 706	int probes = atomic_read(&neigh->probes);
 707
 708	if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1))
 
 
 709		saddr = &ipv6_hdr(skb)->saddr;
 710
 711	if ((probes -= neigh->parms->ucast_probes) < 0) {
 712		if (!(neigh->nud_state & NUD_VALID)) {
 713			ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n",
 714				   __func__, target);
 
 715		}
 716		ndisc_send_ns(dev, neigh, target, target, saddr);
 717	} else if ((probes -= neigh->parms->app_probes) < 0) {
 718#ifdef CONFIG_ARPD
 719		neigh_app_ns(neigh);
 720#endif
 721	} else {
 722		addrconf_addr_solict_mult(target, &mcaddr);
 723		ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
 724	}
 725}
 726
 727static int pndisc_is_router(const void *pkey,
 728			    struct net_device *dev)
 729{
 730	struct pneigh_entry *n;
 731	int ret = -1;
 732
 733	read_lock_bh(&nd_tbl.lock);
 734	n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 735	if (n)
 736		ret = !!(n->flags & NTF_ROUTER);
 737	read_unlock_bh(&nd_tbl.lock);
 738
 739	return ret;
 740}
 741
 
 
 
 
 
 
 
 
 
 742static void ndisc_recv_ns(struct sk_buff *skb)
 743{
 744	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 745	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 746	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 747	u8 *lladdr = NULL;
 748	u32 ndoptlen = skb->tail - (skb->transport_header +
 749				    offsetof(struct nd_msg, opt));
 750	struct ndisc_options ndopts;
 751	struct net_device *dev = skb->dev;
 752	struct inet6_ifaddr *ifp;
 753	struct inet6_dev *idev = NULL;
 754	struct neighbour *neigh;
 755	int dad = ipv6_addr_any(saddr);
 756	int inc;
 757	int is_router = -1;
 
 
 
 
 
 
 758
 759	if (ipv6_addr_is_multicast(&msg->target)) {
 760		ND_PRINTK2(KERN_WARNING
 761			   "ICMPv6 NS: multicast target address");
 762		return;
 763	}
 764
 765	/*
 766	 * RFC2461 7.1.1:
 767	 * DAD has to be destined for solicited node multicast address.
 768	 */
 769	if (dad &&
 770	    !(daddr->s6_addr32[0] == htonl(0xff020000) &&
 771	      daddr->s6_addr32[1] == htonl(0x00000000) &&
 772	      daddr->s6_addr32[2] == htonl(0x00000001) &&
 773	      daddr->s6_addr [12] == 0xff )) {
 774		ND_PRINTK2(KERN_WARNING
 775			   "ICMPv6 NS: bad DAD packet (wrong destination)\n");
 776		return;
 777	}
 778
 779	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 780		ND_PRINTK2(KERN_WARNING
 781			   "ICMPv6 NS: invalid ND options\n");
 782		return;
 783	}
 784
 785	if (ndopts.nd_opts_src_lladdr) {
 786		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 787		if (!lladdr) {
 788			ND_PRINTK2(KERN_WARNING
 789				   "ICMPv6 NS: invalid link-layer address length\n");
 790			return;
 791		}
 792
 793		/* RFC2461 7.1.1:
 794		 *	If the IP source address is the unspecified address,
 795		 *	there MUST NOT be source link-layer address option
 796		 *	in the message.
 797		 */
 798		if (dad) {
 799			ND_PRINTK2(KERN_WARNING
 800				   "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
 801			return;
 802		}
 803	}
 
 
 804
 805	inc = ipv6_addr_is_multicast(daddr);
 806
 807	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 808	if (ifp) {
 809
 810		if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 811			if (dad) {
 812				if (dev->type == ARPHRD_IEEE802_TR) {
 813					const unsigned char *sadr;
 814					sadr = skb_mac_header(skb);
 815					if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
 816					    sadr[9] == dev->dev_addr[1] &&
 817					    sadr[10] == dev->dev_addr[2] &&
 818					    sadr[11] == dev->dev_addr[3] &&
 819					    sadr[12] == dev->dev_addr[4] &&
 820					    sadr[13] == dev->dev_addr[5]) {
 821						/* looped-back to us */
 822						goto out;
 823					}
 824				}
 825
 826				/*
 827				 * We are colliding with another node
 828				 * who is doing DAD
 829				 * so fail our DAD process
 830				 */
 831				addrconf_dad_failure(ifp);
 832				return;
 833			} else {
 834				/*
 835				 * This is not a dad solicitation.
 836				 * If we are an optimistic node,
 837				 * we should respond.
 838				 * Otherwise, we should ignore it.
 839				 */
 840				if (!(ifp->flags & IFA_F_OPTIMISTIC))
 841					goto out;
 842			}
 843		}
 844
 845		idev = ifp->idev;
 846	} else {
 847		struct net *net = dev_net(dev);
 848
 
 
 
 
 
 
 
 
 
 
 
 
 849		idev = in6_dev_get(dev);
 850		if (!idev) {
 851			/* XXX: count this drop? */
 852			return;
 853		}
 854
 855		if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 856		    (idev->cnf.forwarding &&
 857		     (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 858		     (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 859			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 860			    skb->pkt_type != PACKET_HOST &&
 861			    inc != 0 &&
 862			    idev->nd_parms->proxy_delay != 0) {
 863				/*
 864				 * for anycast or proxy,
 865				 * sender should delay its response
 866				 * by a random time between 0 and
 867				 * MAX_ANYCAST_DELAY_TIME seconds.
 868				 * (RFC2461) -- yoshfuji
 869				 */
 870				struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 871				if (n)
 872					pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 873				goto out;
 874			}
 875		} else
 876			goto out;
 877	}
 878
 879	if (is_router < 0)
 880		is_router = !!idev->cnf.forwarding;
 881
 882	if (dad) {
 883		ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
 884			      is_router, 0, (ifp != NULL), 1);
 885		goto out;
 886	}
 887
 888	if (inc)
 889		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 890	else
 891		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 892
 893	/*
 894	 *	update / create cache entry
 895	 *	for the source address
 896	 */
 897	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 898			       !inc || lladdr || !dev->addr_len);
 899	if (neigh)
 900		neigh_update(neigh, lladdr, NUD_STALE,
 901			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 902			     NEIGH_UPDATE_F_OVERRIDE);
 
 903	if (neigh || !dev->header_ops) {
 904		ndisc_send_na(dev, neigh, saddr, &msg->target,
 905			      is_router,
 906			      1, (ifp != NULL && inc), inc);
 907		if (neigh)
 908			neigh_release(neigh);
 909	}
 910
 911out:
 912	if (ifp)
 913		in6_ifa_put(ifp);
 914	else
 915		in6_dev_put(idev);
 916}
 917
 918static void ndisc_recv_na(struct sk_buff *skb)
 919{
 920	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 921	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 922	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 923	u8 *lladdr = NULL;
 924	u32 ndoptlen = skb->tail - (skb->transport_header +
 925				    offsetof(struct nd_msg, opt));
 926	struct ndisc_options ndopts;
 927	struct net_device *dev = skb->dev;
 
 928	struct inet6_ifaddr *ifp;
 929	struct neighbour *neigh;
 930
 931	if (skb->len < sizeof(struct nd_msg)) {
 932		ND_PRINTK2(KERN_WARNING
 933			   "ICMPv6 NA: packet too short\n");
 934		return;
 935	}
 936
 937	if (ipv6_addr_is_multicast(&msg->target)) {
 938		ND_PRINTK2(KERN_WARNING
 939			   "ICMPv6 NA: target address is multicast.\n");
 940		return;
 941	}
 942
 943	if (ipv6_addr_is_multicast(daddr) &&
 944	    msg->icmph.icmp6_solicited) {
 945		ND_PRINTK2(KERN_WARNING
 946			   "ICMPv6 NA: solicited NA is multicasted.\n");
 947		return;
 948	}
 949
 950	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 951		ND_PRINTK2(KERN_WARNING
 952			   "ICMPv6 NS: invalid ND option\n");
 
 
 
 
 
 
 
 953		return;
 954	}
 955	if (ndopts.nd_opts_tgt_lladdr) {
 956		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 957		if (!lladdr) {
 958			ND_PRINTK2(KERN_WARNING
 959				   "ICMPv6 NA: invalid link-layer address length\n");
 960			return;
 961		}
 962	}
 963	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 964	if (ifp) {
 965		if (skb->pkt_type != PACKET_LOOPBACK
 966		    && (ifp->flags & IFA_F_TENTATIVE)) {
 967				addrconf_dad_failure(ifp);
 968				return;
 969		}
 970		/* What should we make now? The advertisement
 971		   is invalid, but ndisc specs say nothing
 972		   about it. It could be misconfiguration, or
 973		   an smart proxy agent tries to help us :-)
 974
 975		   We should not print the error if NA has been
 976		   received from loopback - it is just our own
 977		   unsolicited advertisement.
 978		 */
 979		if (skb->pkt_type != PACKET_LOOPBACK)
 980			ND_PRINTK1(KERN_WARNING
 981			   "ICMPv6 NA: someone advertises our address %pI6 on %s!\n",
 982			   &ifp->addr, ifp->idev->dev->name);
 983		in6_ifa_put(ifp);
 984		return;
 985	}
 986	neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
 987
 988	if (neigh) {
 989		u8 old_flags = neigh->flags;
 990		struct net *net = dev_net(dev);
 991
 992		if (neigh->nud_state & NUD_FAILED)
 993			goto out;
 994
 995		/*
 996		 * Don't update the neighbor cache entry on a proxy NA from
 997		 * ourselves because either the proxied node is off link or it
 998		 * has already sent a NA to us.
 999		 */
1000		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1001		    net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1002		    pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1003			/* XXX: idev->cnf.prixy_ndp */
1004			goto out;
1005		}
1006
1007		neigh_update(neigh, lladdr,
1008			     msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1009			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1010			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1011			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1012			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
 
1013
1014		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1015			/*
1016			 * Change: router to host
1017			 */
1018			struct rt6_info *rt;
1019			rt = rt6_get_dflt_router(saddr, dev);
1020			if (rt)
1021				ip6_del_rt(rt);
1022		}
1023
1024out:
1025		neigh_release(neigh);
1026	}
1027}
1028
1029static void ndisc_recv_rs(struct sk_buff *skb)
1030{
1031	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1032	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1033	struct neighbour *neigh;
1034	struct inet6_dev *idev;
1035	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1036	struct ndisc_options ndopts;
1037	u8 *lladdr = NULL;
1038
1039	if (skb->len < sizeof(*rs_msg))
1040		return;
1041
1042	idev = in6_dev_get(skb->dev);
1043	if (!idev) {
1044		if (net_ratelimit())
1045			ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
1046		return;
1047	}
1048
1049	/* Don't accept RS if we're not in router mode */
1050	if (!idev->cnf.forwarding)
1051		goto out;
1052
1053	/*
1054	 * Don't update NCE if src = ::;
1055	 * this implies that the source node has no ip address assigned yet.
1056	 */
1057	if (ipv6_addr_any(saddr))
1058		goto out;
1059
1060	/* Parse ND options */
1061	if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1062		if (net_ratelimit())
1063			ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
1064		goto out;
1065	}
1066
1067	if (ndopts.nd_opts_src_lladdr) {
1068		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1069					     skb->dev);
1070		if (!lladdr)
1071			goto out;
1072	}
1073
1074	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1075	if (neigh) {
1076		neigh_update(neigh, lladdr, NUD_STALE,
1077			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1078			     NEIGH_UPDATE_F_OVERRIDE|
1079			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
 
1080		neigh_release(neigh);
1081	}
1082out:
1083	in6_dev_put(idev);
1084}
1085
1086static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1087{
1088	struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1089	struct sk_buff *skb;
1090	struct nlmsghdr *nlh;
1091	struct nduseroptmsg *ndmsg;
1092	struct net *net = dev_net(ra->dev);
1093	int err;
1094	int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1095				    + (opt->nd_opt_len << 3));
1096	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1097
1098	skb = nlmsg_new(msg_size, GFP_ATOMIC);
1099	if (skb == NULL) {
1100		err = -ENOBUFS;
1101		goto errout;
1102	}
1103
1104	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1105	if (nlh == NULL) {
1106		goto nla_put_failure;
1107	}
1108
1109	ndmsg = nlmsg_data(nlh);
1110	ndmsg->nduseropt_family = AF_INET6;
1111	ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1112	ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1113	ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1114	ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1115
1116	memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1117
1118	NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
1119		&ipv6_hdr(ra)->saddr);
1120	nlmsg_end(skb, nlh);
1121
1122	rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1123	return;
1124
1125nla_put_failure:
1126	nlmsg_free(skb);
1127	err = -EMSGSIZE;
1128errout:
1129	rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1130}
1131
1132static inline int accept_ra(struct inet6_dev *in6_dev)
1133{
1134	/*
1135	 * If forwarding is enabled, RA are not accepted unless the special
1136	 * hybrid mode (accept_ra=2) is enabled.
1137	 */
1138	if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2)
1139		return 0;
1140
1141	return in6_dev->cnf.accept_ra;
1142}
1143
1144static void ndisc_router_discovery(struct sk_buff *skb)
1145{
1146	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1147	struct neighbour *neigh = NULL;
1148	struct inet6_dev *in6_dev;
1149	struct rt6_info *rt = NULL;
 
1150	int lifetime;
1151	struct ndisc_options ndopts;
1152	int optlen;
1153	unsigned int pref = 0;
 
 
1154
1155	__u8 * opt = (__u8 *)(ra_msg + 1);
1156
1157	optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
 
1158
 
 
 
1159	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1160		ND_PRINTK2(KERN_WARNING
1161			   "ICMPv6 RA: source address is not link-local.\n");
1162		return;
1163	}
1164	if (optlen < 0) {
1165		ND_PRINTK2(KERN_WARNING
1166			   "ICMPv6 RA: packet too short\n");
1167		return;
1168	}
1169
1170#ifdef CONFIG_IPV6_NDISC_NODETYPE
1171	if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1172		ND_PRINTK2(KERN_WARNING
1173			   "ICMPv6 RA: from host or unauthorized router\n");
1174		return;
1175	}
1176#endif
1177
1178	/*
1179	 *	set the RA_RECV flag in the interface
1180	 */
1181
1182	in6_dev = in6_dev_get(skb->dev);
1183	if (in6_dev == NULL) {
1184		ND_PRINTK0(KERN_ERR
1185			   "ICMPv6 RA: can't find inet6 device for %s.\n",
1186			   skb->dev->name);
1187		return;
1188	}
1189
1190	if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1191		in6_dev_put(in6_dev);
1192		ND_PRINTK2(KERN_WARNING
1193			   "ICMP6 RA: invalid ND options\n");
1194		return;
1195	}
1196
1197	if (!accept_ra(in6_dev))
 
 
 
1198		goto skip_linkparms;
 
1199
1200#ifdef CONFIG_IPV6_NDISC_NODETYPE
1201	/* skip link-specific parameters from interior routers */
1202	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
 
 
 
1203		goto skip_linkparms;
 
1204#endif
1205
1206	if (in6_dev->if_flags & IF_RS_SENT) {
1207		/*
1208		 *	flag that an RA was received after an RS was sent
1209		 *	out on this interface.
1210		 */
1211		in6_dev->if_flags |= IF_RA_RCVD;
1212	}
1213
1214	/*
1215	 * Remember the managed/otherconf flags from most recently
1216	 * received RA message (RFC 2462) -- yoshfuji
1217	 */
 
1218	in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1219				IF_RA_OTHERCONF)) |
1220				(ra_msg->icmph.icmp6_addrconf_managed ?
1221					IF_RA_MANAGED : 0) |
1222				(ra_msg->icmph.icmp6_addrconf_other ?
1223					IF_RA_OTHERCONF : 0);
1224
1225	if (!in6_dev->cnf.accept_ra_defrtr)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1226		goto skip_defrtr;
 
1227
1228	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1229
1230#ifdef CONFIG_IPV6_ROUTER_PREF
1231	pref = ra_msg->icmph.icmp6_router_pref;
1232	/* 10b is handled as if it were 00b (medium) */
1233	if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1234	    !in6_dev->cnf.accept_ra_rtr_pref)
1235		pref = ICMPV6_ROUTER_PREF_MEDIUM;
1236#endif
1237
1238	rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1239
1240	if (rt)
1241		neigh = dst_get_neighbour(&rt->dst);
1242
 
 
 
 
 
 
 
 
1243	if (rt && lifetime == 0) {
1244		neigh_clone(neigh);
1245		ip6_del_rt(rt);
1246		rt = NULL;
1247	}
1248
1249	if (rt == NULL && lifetime) {
1250		ND_PRINTK3(KERN_DEBUG
1251			   "ICMPv6 RA: adding default router.\n");
1252
1253		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
1254		if (rt == NULL) {
1255			ND_PRINTK0(KERN_ERR
1256				   "ICMPv6 RA: %s() failed to add default route.\n",
1257				   __func__);
1258			in6_dev_put(in6_dev);
 
1259			return;
1260		}
1261
1262		neigh = dst_get_neighbour(&rt->dst);
1263		if (neigh == NULL) {
1264			ND_PRINTK0(KERN_ERR
1265				   "ICMPv6 RA: %s() got default router without neighbour.\n",
1266				   __func__);
1267			dst_release(&rt->dst);
1268			in6_dev_put(in6_dev);
 
1269			return;
1270		}
1271		neigh->flags |= NTF_ROUTER;
1272	} else if (rt) {
1273		rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1274	}
1275
1276	if (rt)
1277		rt->rt6i_expires = jiffies + (HZ * lifetime);
1278
1279	if (ra_msg->icmph.icmp6_hop_limit) {
1280		in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1281		if (rt)
1282			dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1283				       ra_msg->icmph.icmp6_hop_limit);
 
 
 
1284	}
1285
1286skip_defrtr:
1287
1288	/*
1289	 *	Update Reachable Time and Retrans Timer
1290	 */
1291
1292	if (in6_dev->nd_parms) {
1293		unsigned long rtime = ntohl(ra_msg->retrans_timer);
1294
1295		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1296			rtime = (rtime*HZ)/1000;
1297			if (rtime < HZ/10)
1298				rtime = HZ/10;
1299			in6_dev->nd_parms->retrans_time = rtime;
1300			in6_dev->tstamp = jiffies;
1301			inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1302		}
1303
1304		rtime = ntohl(ra_msg->reachable_time);
1305		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1306			rtime = (rtime*HZ)/1000;
1307
1308			if (rtime < HZ/10)
1309				rtime = HZ/10;
1310
1311			if (rtime != in6_dev->nd_parms->base_reachable_time) {
1312				in6_dev->nd_parms->base_reachable_time = rtime;
1313				in6_dev->nd_parms->gc_staletime = 3 * rtime;
 
 
1314				in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1315				in6_dev->tstamp = jiffies;
1316				inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1317			}
1318		}
1319	}
1320
 
 
 
 
 
 
1321skip_linkparms:
1322
1323	/*
1324	 *	Process options.
1325	 */
1326
1327	if (!neigh)
1328		neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1329				       skb->dev, 1);
1330	if (neigh) {
1331		u8 *lladdr = NULL;
1332		if (ndopts.nd_opts_src_lladdr) {
1333			lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1334						     skb->dev);
1335			if (!lladdr) {
1336				ND_PRINTK2(KERN_WARNING
1337					   "ICMPv6 RA: invalid link-layer address length\n");
1338				goto out;
1339			}
1340		}
1341		neigh_update(neigh, lladdr, NUD_STALE,
1342			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1343			     NEIGH_UPDATE_F_OVERRIDE|
1344			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1345			     NEIGH_UPDATE_F_ISROUTER);
 
1346	}
1347
1348	if (!accept_ra(in6_dev))
 
 
 
1349		goto out;
 
1350
1351#ifdef CONFIG_IPV6_ROUTE_INFO
 
 
 
 
 
 
 
 
 
1352	if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1353		struct nd_opt_hdr *p;
1354		for (p = ndopts.nd_opts_ri;
1355		     p;
1356		     p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1357			struct route_info *ri = (struct route_info *)p;
1358#ifdef CONFIG_IPV6_NDISC_NODETYPE
1359			if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1360			    ri->prefix_len == 0)
1361				continue;
1362#endif
 
 
 
 
 
1363			if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1364				continue;
1365			rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1366				      &ipv6_hdr(skb)->saddr);
1367		}
1368	}
 
 
1369#endif
1370
1371#ifdef CONFIG_IPV6_NDISC_NODETYPE
1372	/* skip link-specific ndopts from interior routers */
1373	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT)
 
 
 
1374		goto out;
 
1375#endif
1376
1377	if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1378		struct nd_opt_hdr *p;
1379		for (p = ndopts.nd_opts_pi;
1380		     p;
1381		     p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1382			addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
 
 
1383		}
1384	}
1385
1386	if (ndopts.nd_opts_mtu) {
1387		__be32 n;
1388		u32 mtu;
1389
1390		memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1391		mtu = ntohl(n);
1392
1393		if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1394			ND_PRINTK2(KERN_WARNING
1395				   "ICMPv6 RA: invalid mtu: %d\n",
1396				   mtu);
1397		} else if (in6_dev->cnf.mtu6 != mtu) {
1398			in6_dev->cnf.mtu6 = mtu;
1399
1400			if (rt)
1401				dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1402
1403			rt6_mtu_change(skb->dev, mtu);
1404		}
1405	}
1406
1407	if (ndopts.nd_useropts) {
1408		struct nd_opt_hdr *p;
1409		for (p = ndopts.nd_useropts;
1410		     p;
1411		     p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
 
1412			ndisc_ra_useropt(skb, p);
1413		}
1414	}
1415
1416	if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1417		ND_PRINTK2(KERN_WARNING
1418			   "ICMPv6 RA: invalid RA options");
1419	}
1420out:
1421	if (rt)
1422		dst_release(&rt->dst);
1423	else if (neigh)
1424		neigh_release(neigh);
1425	in6_dev_put(in6_dev);
1426}
1427
1428static void ndisc_redirect_rcv(struct sk_buff *skb)
1429{
1430	struct inet6_dev *in6_dev;
1431	struct icmp6hdr *icmph;
1432	const struct in6_addr *dest;
1433	const struct in6_addr *target;	/* new first hop to destination */
1434	struct neighbour *neigh;
1435	int on_link = 0;
1436	struct ndisc_options ndopts;
1437	int optlen;
1438	u8 *lladdr = NULL;
 
1439
1440#ifdef CONFIG_IPV6_NDISC_NODETYPE
1441	switch (skb->ndisc_nodetype) {
1442	case NDISC_NODETYPE_HOST:
1443	case NDISC_NODETYPE_NODEFAULT:
1444		ND_PRINTK2(KERN_WARNING
1445			   "ICMPv6 Redirect: from host or unauthorized router\n");
1446		return;
1447	}
1448#endif
1449
1450	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1451		ND_PRINTK2(KERN_WARNING
1452			   "ICMPv6 Redirect: source address is not link-local.\n");
1453		return;
1454	}
1455
1456	optlen = skb->tail - skb->transport_header;
1457	optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
1458
1459	if (optlen < 0) {
1460		ND_PRINTK2(KERN_WARNING
1461			   "ICMPv6 Redirect: packet too short\n");
1462		return;
1463	}
1464
1465	icmph = icmp6_hdr(skb);
1466	target = (const struct in6_addr *) (icmph + 1);
1467	dest = target + 1;
1468
1469	if (ipv6_addr_is_multicast(dest)) {
1470		ND_PRINTK2(KERN_WARNING
1471			   "ICMPv6 Redirect: destination address is multicast.\n");
1472		return;
1473	}
1474
1475	if (ipv6_addr_equal(dest, target)) {
1476		on_link = 1;
1477	} else if (ipv6_addr_type(target) !=
1478		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1479		ND_PRINTK2(KERN_WARNING
1480			   "ICMPv6 Redirect: target address is not link-local unicast.\n");
1481		return;
1482	}
1483
1484	in6_dev = in6_dev_get(skb->dev);
1485	if (!in6_dev)
1486		return;
1487	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
1488		in6_dev_put(in6_dev);
1489		return;
1490	}
1491
1492	/* RFC2461 8.1:
1493	 *	The IP source address of the Redirect MUST be the same as the current
1494	 *	first-hop router for the specified ICMP Destination Address.
1495	 */
 
1496
1497	if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
1498		ND_PRINTK2(KERN_WARNING
1499			   "ICMPv6 Redirect: invalid ND options\n");
1500		in6_dev_put(in6_dev);
1501		return;
1502	}
1503	if (ndopts.nd_opts_tgt_lladdr) {
1504		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1505					     skb->dev);
1506		if (!lladdr) {
1507			ND_PRINTK2(KERN_WARNING
1508				   "ICMPv6 Redirect: invalid link-layer address length\n");
1509			in6_dev_put(in6_dev);
1510			return;
1511		}
1512	}
1513
1514	neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
1515	if (neigh) {
1516		rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
1517			     &ipv6_hdr(skb)->saddr, neigh, lladdr,
1518			     on_link);
1519		neigh_release(neigh);
1520	}
1521	in6_dev_put(in6_dev);
1522}
1523
1524void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
1525			 const struct in6_addr *target)
1526{
1527	struct net_device *dev = skb->dev;
1528	struct net *net = dev_net(dev);
1529	struct sock *sk = net->ipv6.ndisc_sk;
1530	int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
 
1531	struct sk_buff *buff;
1532	struct icmp6hdr *icmph;
1533	struct in6_addr saddr_buf;
1534	struct in6_addr *addrp;
1535	struct rt6_info *rt;
1536	struct dst_entry *dst;
1537	struct inet6_dev *idev;
1538	struct flowi6 fl6;
1539	u8 *opt;
1540	int rd_len;
1541	int err;
1542	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
 
 
 
 
 
 
 
1543
1544	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1545		ND_PRINTK2(KERN_WARNING
1546			   "ICMPv6 Redirect: no link-local address on %s\n",
1547			   dev->name);
1548		return;
1549	}
1550
1551	if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1552	    ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1553		ND_PRINTK2(KERN_WARNING
1554			"ICMPv6 Redirect: target address is not link-local unicast.\n");
1555		return;
1556	}
1557
1558	icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1559			 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1560
1561	dst = ip6_route_output(net, NULL, &fl6);
1562	if (dst == NULL)
 
1563		return;
1564
1565	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1566	if (IS_ERR(dst))
1567		return;
1568
1569	rt = (struct rt6_info *) dst;
1570
1571	if (rt->rt6i_flags & RTF_GATEWAY) {
1572		ND_PRINTK2(KERN_WARNING
1573			   "ICMPv6 Redirect: destination is not a neighbour.\n");
1574		goto release;
1575	}
1576	if (!rt->rt6i_peer)
1577		rt6_bind_peer(rt, 1);
1578	if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
 
 
1579		goto release;
1580
1581	if (dev->addr_len) {
 
 
 
 
 
 
 
1582		read_lock_bh(&neigh->lock);
1583		if (neigh->nud_state & NUD_VALID) {
1584			memcpy(ha_buf, neigh->ha, dev->addr_len);
1585			read_unlock_bh(&neigh->lock);
1586			ha = ha_buf;
1587			len += ndisc_opt_addr_space(dev);
 
 
1588		} else
1589			read_unlock_bh(&neigh->lock);
 
 
1590	}
1591
1592	rd_len = min_t(unsigned int,
1593		     IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
 
1594	rd_len &= ~0x7;
1595	len += rd_len;
1596
1597	buff = sock_alloc_send_skb(sk,
1598				   (MAX_HEADER + sizeof(struct ipv6hdr) +
1599				    len + LL_ALLOCATED_SPACE(dev)),
1600				   1, &err);
1601	if (buff == NULL) {
1602		ND_PRINTK0(KERN_ERR
1603			   "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n",
1604			   __func__, err);
1605		goto release;
1606	}
1607
1608	skb_reserve(buff, LL_RESERVED_SPACE(dev));
1609	ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
1610		   IPPROTO_ICMPV6, len);
1611
1612	skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1613	skb_put(buff, len);
1614	icmph = icmp6_hdr(buff);
1615
1616	memset(icmph, 0, sizeof(struct icmp6hdr));
1617	icmph->icmp6_type = NDISC_REDIRECT;
1618
1619	/*
1620	 *	copy target and destination addresses
1621	 */
1622
1623	addrp = (struct in6_addr *)(icmph + 1);
1624	ipv6_addr_copy(addrp, target);
1625	addrp++;
1626	ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
1627
1628	opt = (u8*) (addrp + 1);
 
 
 
 
 
 
 
1629
1630	/*
1631	 *	include target_address option
1632	 */
1633
1634	if (ha)
1635		opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
1636					     dev->addr_len, dev->type);
1637
1638	/*
1639	 *	build redirect option and copy skb over to the new packet.
1640	 */
1641
1642	memset(opt, 0, 8);
1643	*(opt++) = ND_OPT_REDIRECT_HDR;
1644	*(opt++) = (rd_len >> 3);
1645	opt += 6;
1646
1647	memcpy(opt, ipv6_hdr(skb), rd_len - 8);
1648
1649	icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
1650					     len, IPPROTO_ICMPV6,
1651					     csum_partial(icmph, len, 0));
1652
1653	skb_dst_set(buff, dst);
1654	idev = in6_dev_get(dst->dev);
1655	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
1656	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
1657		      dst_output);
1658	if (!err) {
1659		ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT);
1660		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
1661	}
1662
1663	if (likely(idev != NULL))
1664		in6_dev_put(idev);
1665	return;
1666
1667release:
1668	dst_release(dst);
1669}
1670
1671static void pndisc_redo(struct sk_buff *skb)
1672{
1673	ndisc_recv_ns(skb);
1674	kfree_skb(skb);
1675}
1676
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1677int ndisc_rcv(struct sk_buff *skb)
1678{
1679	struct nd_msg *msg;
1680
1681	if (!pskb_may_pull(skb, skb->len))
 
 
 
1682		return 0;
1683
1684	msg = (struct nd_msg *)skb_transport_header(skb);
1685
1686	__skb_push(skb, skb->data - skb_transport_header(skb));
1687
1688	if (ipv6_hdr(skb)->hop_limit != 255) {
1689		ND_PRINTK2(KERN_WARNING
1690			   "ICMPv6 NDISC: invalid hop-limit: %d\n",
1691			   ipv6_hdr(skb)->hop_limit);
1692		return 0;
1693	}
1694
1695	if (msg->icmph.icmp6_code != 0) {
1696		ND_PRINTK2(KERN_WARNING
1697			   "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
1698			   msg->icmph.icmp6_code);
1699		return 0;
1700	}
1701
1702	memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1703
1704	switch (msg->icmph.icmp6_type) {
1705	case NDISC_NEIGHBOUR_SOLICITATION:
 
1706		ndisc_recv_ns(skb);
1707		break;
1708
1709	case NDISC_NEIGHBOUR_ADVERTISEMENT:
1710		ndisc_recv_na(skb);
1711		break;
1712
1713	case NDISC_ROUTER_SOLICITATION:
1714		ndisc_recv_rs(skb);
1715		break;
1716
1717	case NDISC_ROUTER_ADVERTISEMENT:
1718		ndisc_router_discovery(skb);
1719		break;
1720
1721	case NDISC_REDIRECT:
1722		ndisc_redirect_rcv(skb);
1723		break;
1724	}
1725
1726	return 0;
1727}
1728
1729static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1730{
1731	struct net_device *dev = ptr;
 
1732	struct net *net = dev_net(dev);
 
1733
1734	switch (event) {
1735	case NETDEV_CHANGEADDR:
1736		neigh_changeaddr(&nd_tbl, dev);
1737		fib6_run_gc(~0UL, net);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1738		break;
1739	case NETDEV_DOWN:
1740		neigh_ifdown(&nd_tbl, dev);
1741		fib6_run_gc(~0UL, net);
1742		break;
1743	case NETDEV_NOTIFY_PEERS:
1744		ndisc_send_unsol_na(dev);
1745		break;
1746	default:
1747		break;
1748	}
1749
1750	return NOTIFY_DONE;
1751}
1752
1753static struct notifier_block ndisc_netdev_notifier = {
1754	.notifier_call = ndisc_netdev_event,
 
1755};
1756
1757#ifdef CONFIG_SYSCTL
1758static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1759					 const char *func, const char *dev_name)
1760{
1761	static char warncomm[TASK_COMM_LEN];
1762	static int warned;
1763	if (strcmp(warncomm, current->comm) && warned < 5) {
1764		strcpy(warncomm, current->comm);
1765		printk(KERN_WARNING
1766			"process `%s' is using deprecated sysctl (%s) "
1767			"net.ipv6.neigh.%s.%s; "
1768			"Use net.ipv6.neigh.%s.%s_ms "
1769			"instead.\n",
1770			warncomm, func,
1771			dev_name, ctl->procname,
1772			dev_name, ctl->procname);
1773		warned++;
1774	}
1775}
1776
1777int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
 
1778{
1779	struct net_device *dev = ctl->extra1;
1780	struct inet6_dev *idev;
1781	int ret;
1782
1783	if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1784	    (strcmp(ctl->procname, "base_reachable_time") == 0))
1785		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1786
1787	if (strcmp(ctl->procname, "retrans_time") == 0)
1788		ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1789
1790	else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1791		ret = proc_dointvec_jiffies(ctl, write,
1792					    buffer, lenp, ppos);
1793
1794	else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1795		 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1796		ret = proc_dointvec_ms_jiffies(ctl, write,
1797					       buffer, lenp, ppos);
1798	else
1799		ret = -1;
1800
1801	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1802		if (ctl->data == &idev->nd_parms->base_reachable_time)
1803			idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
 
1804		idev->tstamp = jiffies;
1805		inet6_ifinfo_notify(RTM_NEWLINK, idev);
1806		in6_dev_put(idev);
1807	}
1808	return ret;
1809}
1810
1811
1812#endif
1813
1814static int __net_init ndisc_net_init(struct net *net)
1815{
1816	struct ipv6_pinfo *np;
1817	struct sock *sk;
1818	int err;
1819
1820	err = inet_ctl_sock_create(&sk, PF_INET6,
1821				   SOCK_RAW, IPPROTO_ICMPV6, net);
1822	if (err < 0) {
1823		ND_PRINTK0(KERN_ERR
1824			   "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
1825			   err);
1826		return err;
1827	}
1828
1829	net->ipv6.ndisc_sk = sk;
1830
1831	np = inet6_sk(sk);
1832	np->hop_limit = 255;
1833	/* Do not loopback ndisc messages */
1834	np->mc_loop = 0;
1835
1836	return 0;
1837}
1838
1839static void __net_exit ndisc_net_exit(struct net *net)
1840{
1841	inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1842}
1843
1844static struct pernet_operations ndisc_net_ops = {
1845	.init = ndisc_net_init,
1846	.exit = ndisc_net_exit,
1847};
1848
1849int __init ndisc_init(void)
1850{
1851	int err;
1852
1853	err = register_pernet_subsys(&ndisc_net_ops);
1854	if (err)
1855		return err;
1856	/*
1857	 * Initialize the neighbour table
1858	 */
1859	neigh_table_init(&nd_tbl);
1860
1861#ifdef CONFIG_SYSCTL
1862	err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6",
1863				    &ndisc_ifinfo_sysctl_change);
1864	if (err)
1865		goto out_unregister_pernet;
1866#endif
1867	err = register_netdevice_notifier(&ndisc_netdev_notifier);
1868	if (err)
1869		goto out_unregister_sysctl;
1870out:
 
1871	return err;
1872
1873out_unregister_sysctl:
1874#ifdef CONFIG_SYSCTL
1875	neigh_sysctl_unregister(&nd_tbl.parms);
1876out_unregister_pernet:
1877#endif
1878	unregister_pernet_subsys(&ndisc_net_ops);
1879	goto out;
 
1880}
1881
1882void ndisc_cleanup(void)
 
 
 
 
 
1883{
1884	unregister_netdevice_notifier(&ndisc_netdev_notifier);
 
 
 
 
1885#ifdef CONFIG_SYSCTL
1886	neigh_sysctl_unregister(&nd_tbl.parms);
1887#endif
1888	neigh_table_clear(&nd_tbl);
1889	unregister_pernet_subsys(&ndisc_net_ops);
1890}
v5.9
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	Neighbour Discovery for IPv6
   4 *	Linux INET6 implementation
   5 *
   6 *	Authors:
   7 *	Pedro Roque		<roque@di.fc.ul.pt>
   8 *	Mike Shaver		<shaver@ingenia.com>
 
 
 
 
 
   9 */
  10
  11/*
  12 *	Changes:
  13 *
  14 *	Alexey I. Froloff		:	RFC6106 (DNSSL) support
  15 *	Pierre Ynard			:	export userland ND options
  16 *						through netlink (RDNSS support)
  17 *	Lars Fenneberg			:	fixed MTU setting on receipt
  18 *						of an RA.
  19 *	Janos Farkas			:	kmalloc failure checks
  20 *	Alexey Kuznetsov		:	state machine reworked
  21 *						and moved to net/core.
  22 *	Pekka Savola			:	RFC2461 validation
  23 *	YOSHIFUJI Hideaki @USAGI	:	Verify ND options properly
  24 */
  25
  26#define pr_fmt(fmt) "ICMPv6: " fmt
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  27
  28#include <linux/module.h>
  29#include <linux/errno.h>
  30#include <linux/types.h>
  31#include <linux/socket.h>
  32#include <linux/sockios.h>
  33#include <linux/sched.h>
  34#include <linux/net.h>
  35#include <linux/in6.h>
  36#include <linux/route.h>
  37#include <linux/init.h>
  38#include <linux/rcupdate.h>
  39#include <linux/slab.h>
  40#ifdef CONFIG_SYSCTL
  41#include <linux/sysctl.h>
  42#endif
  43
  44#include <linux/if_addr.h>
  45#include <linux/if_ether.h>
  46#include <linux/if_arp.h>
  47#include <linux/ipv6.h>
  48#include <linux/icmpv6.h>
  49#include <linux/jhash.h>
  50
  51#include <net/sock.h>
  52#include <net/snmp.h>
  53
  54#include <net/ipv6.h>
  55#include <net/protocol.h>
  56#include <net/ndisc.h>
  57#include <net/ip6_route.h>
  58#include <net/addrconf.h>
  59#include <net/icmp.h>
  60
  61#include <net/netlink.h>
  62#include <linux/rtnetlink.h>
  63
  64#include <net/flow.h>
  65#include <net/ip6_checksum.h>
  66#include <net/inet_common.h>
  67#include <linux/proc_fs.h>
  68
  69#include <linux/netfilter.h>
  70#include <linux/netfilter_ipv6.h>
  71
  72static u32 ndisc_hash(const void *pkey,
  73		      const struct net_device *dev,
  74		      __u32 *hash_rnd);
  75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
  76static bool ndisc_allow_add(const struct net_device *dev,
  77			    struct netlink_ext_ack *extack);
  78static int ndisc_constructor(struct neighbour *neigh);
  79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  81static int pndisc_constructor(struct pneigh_entry *n);
  82static void pndisc_destructor(struct pneigh_entry *n);
  83static void pndisc_redo(struct sk_buff *skb);
  84
  85static const struct neigh_ops ndisc_generic_ops = {
  86	.family =		AF_INET6,
  87	.solicit =		ndisc_solicit,
  88	.error_report =		ndisc_error_report,
  89	.output =		neigh_resolve_output,
  90	.connected_output =	neigh_connected_output,
  91};
  92
  93static const struct neigh_ops ndisc_hh_ops = {
  94	.family =		AF_INET6,
  95	.solicit =		ndisc_solicit,
  96	.error_report =		ndisc_error_report,
  97	.output =		neigh_resolve_output,
  98	.connected_output =	neigh_resolve_output,
  99};
 100
 101
 102static const struct neigh_ops ndisc_direct_ops = {
 103	.family =		AF_INET6,
 104	.output =		neigh_direct_output,
 105	.connected_output =	neigh_direct_output,
 106};
 107
 108struct neigh_table nd_tbl = {
 109	.family =	AF_INET6,
 
 110	.key_len =	sizeof(struct in6_addr),
 111	.protocol =	cpu_to_be16(ETH_P_IPV6),
 112	.hash =		ndisc_hash,
 113	.key_eq =	ndisc_key_eq,
 114	.constructor =	ndisc_constructor,
 115	.pconstructor =	pndisc_constructor,
 116	.pdestructor =	pndisc_destructor,
 117	.proxy_redo =	pndisc_redo,
 118	.allow_add  =   ndisc_allow_add,
 119	.id =		"ndisc_cache",
 120	.parms = {
 121		.tbl			= &nd_tbl,
 
 
 
 122		.reachable_time		= ND_REACHABLE_TIME,
 123		.data = {
 124			[NEIGH_VAR_MCAST_PROBES] = 3,
 125			[NEIGH_VAR_UCAST_PROBES] = 3,
 126			[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
 127			[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
 128			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
 129			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 130			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 131			[NEIGH_VAR_PROXY_QLEN] = 64,
 132			[NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
 133			[NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
 134		},
 135	},
 136	.gc_interval =	  30 * HZ,
 137	.gc_thresh1 =	 128,
 138	.gc_thresh2 =	 512,
 139	.gc_thresh3 =	1024,
 140};
 141EXPORT_SYMBOL_GPL(nd_tbl);
 142
 143void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 144			      int data_len, int pad)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 145{
 146	int space = __ndisc_opt_addr_space(data_len, pad);
 147	u8 *opt = skb_put(skb, space);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 148
 149	opt[0] = type;
 150	opt[1] = space>>3;
 151
 152	memset(opt + 2, 0, pad);
 153	opt   += pad;
 154	space -= pad;
 155
 156	memcpy(opt+2, data, data_len);
 157	data_len += 2;
 158	opt += data_len;
 159	space -= data_len;
 160	if (space > 0)
 161		memset(opt, 0, space);
 162}
 163EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
 164
 165static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
 166					  void *data, u8 icmp6_type)
 167{
 168	__ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
 169				 ndisc_addr_option_pad(skb->dev->type));
 170	ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
 171}
 172
 173static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
 174						   void *ha,
 175						   const u8 *ops_data)
 176{
 177	ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
 178	ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
 179}
 180
 181static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 182					    struct nd_opt_hdr *end)
 183{
 184	int type;
 185	if (!cur || !end || cur >= end)
 186		return NULL;
 187	type = cur->nd_opt_type;
 188	do {
 189		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 190	} while (cur < end && cur->nd_opt_type != type);
 191	return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 192}
 193
 194static inline int ndisc_is_useropt(const struct net_device *dev,
 195				   struct nd_opt_hdr *opt)
 196{
 197	return opt->nd_opt_type == ND_OPT_RDNSS ||
 198		opt->nd_opt_type == ND_OPT_DNSSL ||
 199		opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
 200		opt->nd_opt_type == ND_OPT_PREF64 ||
 201		ndisc_ops_is_useropt(dev, opt->nd_opt_type);
 202}
 203
 204static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
 205					     struct nd_opt_hdr *cur,
 206					     struct nd_opt_hdr *end)
 207{
 208	if (!cur || !end || cur >= end)
 209		return NULL;
 210	do {
 211		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 212	} while (cur < end && !ndisc_is_useropt(dev, cur));
 213	return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
 214}
 215
 216struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 217					  u8 *opt, int opt_len,
 218					  struct ndisc_options *ndopts)
 219{
 220	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 221
 222	if (!nd_opt || opt_len < 0 || !ndopts)
 223		return NULL;
 224	memset(ndopts, 0, sizeof(*ndopts));
 225	while (opt_len) {
 226		int l;
 227		if (opt_len < sizeof(struct nd_opt_hdr))
 228			return NULL;
 229		l = nd_opt->nd_opt_len << 3;
 230		if (opt_len < l || l == 0)
 231			return NULL;
 232		if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
 233			goto next_opt;
 234		switch (nd_opt->nd_opt_type) {
 235		case ND_OPT_SOURCE_LL_ADDR:
 236		case ND_OPT_TARGET_LL_ADDR:
 237		case ND_OPT_MTU:
 238		case ND_OPT_NONCE:
 239		case ND_OPT_REDIRECT_HDR:
 240			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 241				ND_PRINTK(2, warn,
 242					  "%s: duplicated ND6 option found: type=%d\n",
 243					  __func__, nd_opt->nd_opt_type);
 
 244			} else {
 245				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 246			}
 247			break;
 248		case ND_OPT_PREFIX_INFO:
 249			ndopts->nd_opts_pi_end = nd_opt;
 250			if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 251				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 252			break;
 253#ifdef CONFIG_IPV6_ROUTE_INFO
 254		case ND_OPT_ROUTE_INFO:
 255			ndopts->nd_opts_ri_end = nd_opt;
 256			if (!ndopts->nd_opts_ri)
 257				ndopts->nd_opts_ri = nd_opt;
 258			break;
 259#endif
 260		default:
 261			if (ndisc_is_useropt(dev, nd_opt)) {
 262				ndopts->nd_useropts_end = nd_opt;
 263				if (!ndopts->nd_useropts)
 264					ndopts->nd_useropts = nd_opt;
 265			} else {
 266				/*
 267				 * Unknown options must be silently ignored,
 268				 * to accommodate future extension to the
 269				 * protocol.
 270				 */
 271				ND_PRINTK(2, notice,
 272					  "%s: ignored unsupported option; type=%d, len=%d\n",
 273					  __func__,
 274					  nd_opt->nd_opt_type,
 275					  nd_opt->nd_opt_len);
 276			}
 277		}
 278next_opt:
 279		opt_len -= l;
 280		nd_opt = ((void *)nd_opt) + l;
 281	}
 282	return ndopts;
 283}
 284
 
 
 
 
 
 
 
 
 
 
 
 285int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 286{
 287	switch (dev->type) {
 288	case ARPHRD_ETHER:
 289	case ARPHRD_IEEE802:	/* Not sure. Check it later. --ANK */
 290	case ARPHRD_FDDI:
 291		ipv6_eth_mc_map(addr, buf);
 292		return 0;
 
 
 
 293	case ARPHRD_ARCNET:
 294		ipv6_arcnet_mc_map(addr, buf);
 295		return 0;
 296	case ARPHRD_INFINIBAND:
 297		ipv6_ib_mc_map(addr, dev->broadcast, buf);
 298		return 0;
 299	case ARPHRD_IPGRE:
 300		return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 301	default:
 302		if (dir) {
 303			memcpy(buf, dev->broadcast, dev->addr_len);
 304			return 0;
 305		}
 306	}
 307	return -EINVAL;
 308}
 
 309EXPORT_SYMBOL(ndisc_mc_map);
 310
 311static u32 ndisc_hash(const void *pkey,
 312		      const struct net_device *dev,
 313		      __u32 *hash_rnd)
 314{
 315	return ndisc_hashfn(pkey, dev, hash_rnd);
 316}
 
 
 
 
 317
 318static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
 319{
 320	return neigh_key_eq128(n, pkey);
 321}
 322
 323static int ndisc_constructor(struct neighbour *neigh)
 324{
 325	struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
 326	struct net_device *dev = neigh->dev;
 327	struct inet6_dev *in6_dev;
 328	struct neigh_parms *parms;
 329	bool is_multicast = ipv6_addr_is_multicast(addr);
 330
 
 331	in6_dev = in6_dev_get(dev);
 332	if (!in6_dev) {
 
 333		return -EINVAL;
 334	}
 335
 336	parms = in6_dev->nd_parms;
 337	__neigh_parms_put(neigh->parms);
 338	neigh->parms = neigh_parms_clone(parms);
 
 339
 340	neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 341	if (!dev->header_ops) {
 342		neigh->nud_state = NUD_NOARP;
 343		neigh->ops = &ndisc_direct_ops;
 344		neigh->output = neigh_direct_output;
 345	} else {
 346		if (is_multicast) {
 347			neigh->nud_state = NUD_NOARP;
 348			ndisc_mc_map(addr, neigh->ha, dev, 1);
 349		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 350			neigh->nud_state = NUD_NOARP;
 351			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 352			if (dev->flags&IFF_LOOPBACK)
 353				neigh->type = RTN_LOCAL;
 354		} else if (dev->flags&IFF_POINTOPOINT) {
 355			neigh->nud_state = NUD_NOARP;
 356			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 357		}
 358		if (dev->header_ops->cache)
 359			neigh->ops = &ndisc_hh_ops;
 360		else
 361			neigh->ops = &ndisc_generic_ops;
 362		if (neigh->nud_state&NUD_VALID)
 363			neigh->output = neigh->ops->connected_output;
 364		else
 365			neigh->output = neigh->ops->output;
 366	}
 367	in6_dev_put(in6_dev);
 368	return 0;
 369}
 370
 371static int pndisc_constructor(struct pneigh_entry *n)
 372{
 373	struct in6_addr *addr = (struct in6_addr *)&n->key;
 374	struct in6_addr maddr;
 375	struct net_device *dev = n->dev;
 376
 377	if (!dev || !__in6_dev_get(dev))
 378		return -EINVAL;
 379	addrconf_addr_solict_mult(addr, &maddr);
 380	ipv6_dev_mc_inc(dev, &maddr);
 381	return 0;
 382}
 383
 384static void pndisc_destructor(struct pneigh_entry *n)
 385{
 386	struct in6_addr *addr = (struct in6_addr *)&n->key;
 387	struct in6_addr maddr;
 388	struct net_device *dev = n->dev;
 389
 390	if (!dev || !__in6_dev_get(dev))
 391		return;
 392	addrconf_addr_solict_mult(addr, &maddr);
 393	ipv6_dev_mc_dec(dev, &maddr);
 394}
 395
 396/* called with rtnl held */
 397static bool ndisc_allow_add(const struct net_device *dev,
 398			    struct netlink_ext_ack *extack)
 
 
 
 399{
 400	struct inet6_dev *idev = __in6_dev_get(dev);
 
 
 
 
 
 
 401
 402	if (!idev || idev->cnf.disable_ipv6) {
 403		NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
 404		return false;
 405	}
 406
 407	return true;
 408}
 409
 410static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 411				       int len)
 412{
 413	int hlen = LL_RESERVED_SPACE(dev);
 414	int tlen = dev->needed_tailroom;
 415	struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
 416	struct sk_buff *skb;
 417
 418	skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
 419	if (!skb) {
 420		ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
 421			  __func__);
 
 422		return NULL;
 423	}
 424
 425	skb->protocol = htons(ETH_P_IPV6);
 426	skb->dev = dev;
 427
 428	skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
 429	skb_reset_transport_header(skb);
 430
 431	/* Manually assign socket ownership as we avoid calling
 432	 * sock_alloc_send_pskb() to bypass wmem buffer limits
 433	 */
 434	skb_set_owner_w(skb, sk);
 435
 436	return skb;
 437}
 
 
 
 438
 439static void ip6_nd_hdr(struct sk_buff *skb,
 440		       const struct in6_addr *saddr,
 441		       const struct in6_addr *daddr,
 442		       int hop_limit, int len)
 443{
 444	struct ipv6hdr *hdr;
 445	struct inet6_dev *idev;
 446	unsigned tclass;
 447
 448	rcu_read_lock();
 449	idev = __in6_dev_get(skb->dev);
 450	tclass = idev ? idev->cnf.ndisc_tclass : 0;
 451	rcu_read_unlock();
 452
 453	skb_push(skb, sizeof(*hdr));
 454	skb_reset_network_header(skb);
 455	hdr = ipv6_hdr(skb);
 456
 457	ip6_flow_hdr(hdr, tclass, 0);
 458
 459	hdr->payload_len = htons(len);
 460	hdr->nexthdr = IPPROTO_ICMPV6;
 461	hdr->hop_limit = hop_limit;
 462
 463	hdr->saddr = *saddr;
 464	hdr->daddr = *daddr;
 465}
 466
 467static void ndisc_send_skb(struct sk_buff *skb,
 468			   const struct in6_addr *daddr,
 469			   const struct in6_addr *saddr)
 
 
 
 470{
 471	struct dst_entry *dst = skb_dst(skb);
 472	struct net *net = dev_net(skb->dev);
 
 473	struct sock *sk = net->ipv6.ndisc_sk;
 474	struct inet6_dev *idev;
 475	int err;
 476	struct icmp6hdr *icmp6h = icmp6_hdr(skb);
 477	u8 type;
 478
 479	type = icmp6h->icmp6_type;
 480
 
 
 
 481	if (!dst) {
 482		struct flowi6 fl6;
 483		int oif = skb->dev->ifindex;
 
 484
 485		icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
 486		dst = icmp6_dst_alloc(skb->dev, &fl6);
 487		if (IS_ERR(dst)) {
 488			kfree_skb(skb);
 489			return;
 490		}
 491
 492		skb_dst_set(skb, dst);
 493	}
 494
 495	icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
 496					      IPPROTO_ICMPV6,
 497					      csum_partial(icmp6h,
 498							   skb->len, 0));
 499
 500	ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
 501
 502	rcu_read_lock();
 503	idev = __in6_dev_get(dst->dev);
 504	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 505
 506	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
 507		      net, sk, skb, NULL, dst->dev,
 508		      dst_output);
 509	if (!err) {
 510		ICMP6MSGOUT_INC_STATS(net, idev, type);
 511		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 512	}
 513
 514	rcu_read_unlock();
 
 515}
 516
 517void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 518		   const struct in6_addr *solicited_addr,
 519		   bool router, bool solicited, bool override, bool inc_opt)
 
 
 
 
 
 
 
 
 520{
 521	struct sk_buff *skb;
 
 
 
 
 
 
 
 
 
 
 
 
 
 522	struct in6_addr tmpaddr;
 523	struct inet6_ifaddr *ifp;
 524	const struct in6_addr *src_addr;
 525	struct nd_msg *msg;
 526	int optlen = 0;
 
 527
 528	/* for anycast or proxy, solicited_addr != src_addr */
 529	ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 530	if (ifp) {
 531		src_addr = solicited_addr;
 532		if (ifp->flags & IFA_F_OPTIMISTIC)
 533			override = false;
 534		inc_opt |= ifp->idev->cnf.force_tllao;
 535		in6_ifa_put(ifp);
 536	} else {
 537		if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 538				       inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 539				       &tmpaddr))
 540			return;
 541		src_addr = &tmpaddr;
 542	}
 543
 544	if (!dev->addr_len)
 545		inc_opt = false;
 546	if (inc_opt)
 547		optlen += ndisc_opt_addr_space(dev,
 548					       NDISC_NEIGHBOUR_ADVERTISEMENT);
 549
 550	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 551	if (!skb)
 552		return;
 553
 554	msg = skb_put(skb, sizeof(*msg));
 555	*msg = (struct nd_msg) {
 556		.icmph = {
 557			.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 558			.icmp6_router = router,
 559			.icmp6_solicited = solicited,
 560			.icmp6_override = override,
 561		},
 562		.target = *solicited_addr,
 563	};
 564
 565	if (inc_opt)
 566		ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 567				       dev->dev_addr,
 568				       NDISC_NEIGHBOUR_ADVERTISEMENT);
 569
 570	ndisc_send_skb(skb, daddr, src_addr);
 571}
 572
 573static void ndisc_send_unsol_na(struct net_device *dev)
 574{
 575	struct inet6_dev *idev;
 576	struct inet6_ifaddr *ifa;
 
 577
 578	idev = in6_dev_get(dev);
 579	if (!idev)
 580		return;
 581
 582	read_lock_bh(&idev->lock);
 583	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 584		/* skip tentative addresses until dad completes */
 585		if (ifa->flags & IFA_F_TENTATIVE &&
 586		    !(ifa->flags & IFA_F_OPTIMISTIC))
 587			continue;
 588
 589		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
 590			      /*router=*/ !!idev->cnf.forwarding,
 591			      /*solicited=*/ false, /*override=*/ true,
 592			      /*inc_opt=*/ true);
 593	}
 594	read_unlock_bh(&idev->lock);
 595
 596	in6_dev_put(idev);
 597}
 598
 599void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 600		   const struct in6_addr *daddr, const struct in6_addr *saddr,
 601		   u64 nonce)
 602{
 603	struct sk_buff *skb;
 604	struct in6_addr addr_buf;
 605	int inc_opt = dev->addr_len;
 606	int optlen = 0;
 607	struct nd_msg *msg;
 608
 609	if (!saddr) {
 610		if (ipv6_get_lladdr(dev, &addr_buf,
 611				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 612			return;
 613		saddr = &addr_buf;
 614	}
 615
 616	if (ipv6_addr_any(saddr))
 617		inc_opt = false;
 618	if (inc_opt)
 619		optlen += ndisc_opt_addr_space(dev,
 620					       NDISC_NEIGHBOUR_SOLICITATION);
 621	if (nonce != 0)
 622		optlen += 8;
 623
 624	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 625	if (!skb)
 626		return;
 627
 628	msg = skb_put(skb, sizeof(*msg));
 629	*msg = (struct nd_msg) {
 630		.icmph = {
 631			.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 632		},
 633		.target = *solicit,
 634	};
 635
 636	if (inc_opt)
 637		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 638				       dev->dev_addr,
 639				       NDISC_NEIGHBOUR_SOLICITATION);
 640	if (nonce != 0) {
 641		u8 *opt = skb_put(skb, 8);
 642
 643		opt[0] = ND_OPT_NONCE;
 644		opt[1] = 8 >> 3;
 645		memcpy(opt + 2, &nonce, 6);
 646	}
 647
 648	ndisc_send_skb(skb, daddr, saddr);
 649}
 650
 651void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 652		   const struct in6_addr *daddr)
 653{
 654	struct sk_buff *skb;
 655	struct rs_msg *msg;
 
 656	int send_sllao = dev->addr_len;
 657	int optlen = 0;
 658
 659#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 660	/*
 661	 * According to section 2.2 of RFC 4429, we must not
 662	 * send router solicitations with a sllao from
 663	 * optimistic addresses, but we may send the solicitation
 664	 * if we don't include the sllao.  So here we check
 665	 * if our address is optimistic, and if so, we
 666	 * suppress the inclusion of the sllao.
 667	 */
 668	if (send_sllao) {
 669		struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 670							   dev, 1);
 671		if (ifp) {
 672			if (ifp->flags & IFA_F_OPTIMISTIC)  {
 673				send_sllao = 0;
 674			}
 675			in6_ifa_put(ifp);
 676		} else {
 677			send_sllao = 0;
 678		}
 679	}
 680#endif
 681	if (send_sllao)
 682		optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
 683
 684	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 685	if (!skb)
 686		return;
 687
 688	msg = skb_put(skb, sizeof(*msg));
 689	*msg = (struct rs_msg) {
 690		.icmph = {
 691			.icmp6_type = NDISC_ROUTER_SOLICITATION,
 692		},
 693	};
 694
 695	if (send_sllao)
 696		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 697				       dev->dev_addr,
 698				       NDISC_ROUTER_SOLICITATION);
 699
 700	ndisc_send_skb(skb, daddr, saddr);
 701}
 702
 703
 704static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 705{
 706	/*
 707	 *	"The sender MUST return an ICMP
 708	 *	 destination unreachable"
 709	 */
 710	dst_link_failure(skb);
 711	kfree_skb(skb);
 712}
 713
 714/* Called with locked neigh: either read or both */
 715
 716static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 717{
 718	struct in6_addr *saddr = NULL;
 719	struct in6_addr mcaddr;
 720	struct net_device *dev = neigh->dev;
 721	struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 722	int probes = atomic_read(&neigh->probes);
 723
 724	if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
 725					   dev, false, 1,
 726					   IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
 727		saddr = &ipv6_hdr(skb)->saddr;
 728	probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
 729	if (probes < 0) {
 730		if (!(neigh->nud_state & NUD_VALID)) {
 731			ND_PRINTK(1, dbg,
 732				  "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
 733				  __func__, target);
 734		}
 735		ndisc_send_ns(dev, target, target, saddr, 0);
 736	} else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
 
 737		neigh_app_ns(neigh);
 
 738	} else {
 739		addrconf_addr_solict_mult(target, &mcaddr);
 740		ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
 741	}
 742}
 743
 744static int pndisc_is_router(const void *pkey,
 745			    struct net_device *dev)
 746{
 747	struct pneigh_entry *n;
 748	int ret = -1;
 749
 750	read_lock_bh(&nd_tbl.lock);
 751	n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 752	if (n)
 753		ret = !!(n->flags & NTF_ROUTER);
 754	read_unlock_bh(&nd_tbl.lock);
 755
 756	return ret;
 757}
 758
 759void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 760		  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 761		  struct ndisc_options *ndopts)
 762{
 763	neigh_update(neigh, lladdr, new, flags, 0);
 764	/* report ndisc ops about neighbour update */
 765	ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
 766}
 767
 768static void ndisc_recv_ns(struct sk_buff *skb)
 769{
 770	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 771	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 772	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 773	u8 *lladdr = NULL;
 774	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 775				    offsetof(struct nd_msg, opt));
 776	struct ndisc_options ndopts;
 777	struct net_device *dev = skb->dev;
 778	struct inet6_ifaddr *ifp;
 779	struct inet6_dev *idev = NULL;
 780	struct neighbour *neigh;
 781	int dad = ipv6_addr_any(saddr);
 782	bool inc;
 783	int is_router = -1;
 784	u64 nonce = 0;
 785
 786	if (skb->len < sizeof(struct nd_msg)) {
 787		ND_PRINTK(2, warn, "NS: packet too short\n");
 788		return;
 789	}
 790
 791	if (ipv6_addr_is_multicast(&msg->target)) {
 792		ND_PRINTK(2, warn, "NS: multicast target address\n");
 
 793		return;
 794	}
 795
 796	/*
 797	 * RFC2461 7.1.1:
 798	 * DAD has to be destined for solicited node multicast address.
 799	 */
 800	if (dad && !ipv6_addr_is_solict_mult(daddr)) {
 801		ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
 
 
 
 
 
 802		return;
 803	}
 804
 805	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 806		ND_PRINTK(2, warn, "NS: invalid ND options\n");
 
 807		return;
 808	}
 809
 810	if (ndopts.nd_opts_src_lladdr) {
 811		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 812		if (!lladdr) {
 813			ND_PRINTK(2, warn,
 814				  "NS: invalid link-layer address length\n");
 815			return;
 816		}
 817
 818		/* RFC2461 7.1.1:
 819		 *	If the IP source address is the unspecified address,
 820		 *	there MUST NOT be source link-layer address option
 821		 *	in the message.
 822		 */
 823		if (dad) {
 824			ND_PRINTK(2, warn,
 825				  "NS: bad DAD packet (link-layer address option)\n");
 826			return;
 827		}
 828	}
 829	if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
 830		memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
 831
 832	inc = ipv6_addr_is_multicast(daddr);
 833
 834	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 835	if (ifp) {
 836have_ifp:
 837		if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 838			if (dad) {
 839				if (nonce != 0 && ifp->dad_nonce == nonce) {
 840					u8 *np = (u8 *)&nonce;
 841					/* Matching nonce if looped back */
 842					ND_PRINTK(2, notice,
 843						  "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
 844						  ifp->idev->dev->name,
 845						  &ifp->addr, np);
 846					goto out;
 
 
 
 
 847				}
 
 848				/*
 849				 * We are colliding with another node
 850				 * who is doing DAD
 851				 * so fail our DAD process
 852				 */
 853				addrconf_dad_failure(skb, ifp);
 854				return;
 855			} else {
 856				/*
 857				 * This is not a dad solicitation.
 858				 * If we are an optimistic node,
 859				 * we should respond.
 860				 * Otherwise, we should ignore it.
 861				 */
 862				if (!(ifp->flags & IFA_F_OPTIMISTIC))
 863					goto out;
 864			}
 865		}
 866
 867		idev = ifp->idev;
 868	} else {
 869		struct net *net = dev_net(dev);
 870
 871		/* perhaps an address on the master device */
 872		if (netif_is_l3_slave(dev)) {
 873			struct net_device *mdev;
 874
 875			mdev = netdev_master_upper_dev_get_rcu(dev);
 876			if (mdev) {
 877				ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
 878				if (ifp)
 879					goto have_ifp;
 880			}
 881		}
 882
 883		idev = in6_dev_get(dev);
 884		if (!idev) {
 885			/* XXX: count this drop? */
 886			return;
 887		}
 888
 889		if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 890		    (idev->cnf.forwarding &&
 891		     (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 892		     (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 893			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 894			    skb->pkt_type != PACKET_HOST &&
 895			    inc &&
 896			    NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
 897				/*
 898				 * for anycast or proxy,
 899				 * sender should delay its response
 900				 * by a random time between 0 and
 901				 * MAX_ANYCAST_DELAY_TIME seconds.
 902				 * (RFC2461) -- yoshfuji
 903				 */
 904				struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 905				if (n)
 906					pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 907				goto out;
 908			}
 909		} else
 910			goto out;
 911	}
 912
 913	if (is_router < 0)
 914		is_router = idev->cnf.forwarding;
 915
 916	if (dad) {
 917		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
 918			      !!is_router, false, (ifp != NULL), true);
 919		goto out;
 920	}
 921
 922	if (inc)
 923		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 924	else
 925		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 926
 927	/*
 928	 *	update / create cache entry
 929	 *	for the source address
 930	 */
 931	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 932			       !inc || lladdr || !dev->addr_len);
 933	if (neigh)
 934		ndisc_update(dev, neigh, lladdr, NUD_STALE,
 935			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 936			     NEIGH_UPDATE_F_OVERRIDE,
 937			     NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
 938	if (neigh || !dev->header_ops) {
 939		ndisc_send_na(dev, saddr, &msg->target, !!is_router,
 940			      true, (ifp != NULL && inc), inc);
 
 941		if (neigh)
 942			neigh_release(neigh);
 943	}
 944
 945out:
 946	if (ifp)
 947		in6_ifa_put(ifp);
 948	else
 949		in6_dev_put(idev);
 950}
 951
 952static void ndisc_recv_na(struct sk_buff *skb)
 953{
 954	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 955	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 956	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 957	u8 *lladdr = NULL;
 958	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 959				    offsetof(struct nd_msg, opt));
 960	struct ndisc_options ndopts;
 961	struct net_device *dev = skb->dev;
 962	struct inet6_dev *idev = __in6_dev_get(dev);
 963	struct inet6_ifaddr *ifp;
 964	struct neighbour *neigh;
 965
 966	if (skb->len < sizeof(struct nd_msg)) {
 967		ND_PRINTK(2, warn, "NA: packet too short\n");
 
 968		return;
 969	}
 970
 971	if (ipv6_addr_is_multicast(&msg->target)) {
 972		ND_PRINTK(2, warn, "NA: target address is multicast\n");
 
 973		return;
 974	}
 975
 976	if (ipv6_addr_is_multicast(daddr) &&
 977	    msg->icmph.icmp6_solicited) {
 978		ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
 
 979		return;
 980	}
 981
 982	/* For some 802.11 wireless deployments (and possibly other networks),
 983	 * there will be a NA proxy and unsolicitd packets are attacks
 984	 * and thus should not be accepted.
 985	 */
 986	if (!msg->icmph.icmp6_solicited && idev &&
 987	    idev->cnf.drop_unsolicited_na)
 988		return;
 989
 990	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 991		ND_PRINTK(2, warn, "NS: invalid ND option\n");
 992		return;
 993	}
 994	if (ndopts.nd_opts_tgt_lladdr) {
 995		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 996		if (!lladdr) {
 997			ND_PRINTK(2, warn,
 998				  "NA: invalid link-layer address length\n");
 999			return;
1000		}
1001	}
1002	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1003	if (ifp) {
1004		if (skb->pkt_type != PACKET_LOOPBACK
1005		    && (ifp->flags & IFA_F_TENTATIVE)) {
1006				addrconf_dad_failure(skb, ifp);
1007				return;
1008		}
1009		/* What should we make now? The advertisement
1010		   is invalid, but ndisc specs say nothing
1011		   about it. It could be misconfiguration, or
1012		   an smart proxy agent tries to help us :-)
1013
1014		   We should not print the error if NA has been
1015		   received from loopback - it is just our own
1016		   unsolicited advertisement.
1017		 */
1018		if (skb->pkt_type != PACKET_LOOPBACK)
1019			ND_PRINTK(1, warn,
1020				  "NA: %pM advertised our address %pI6c on %s!\n",
1021				  eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1022		in6_ifa_put(ifp);
1023		return;
1024	}
1025	neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1026
1027	if (neigh) {
1028		u8 old_flags = neigh->flags;
1029		struct net *net = dev_net(dev);
1030
1031		if (neigh->nud_state & NUD_FAILED)
1032			goto out;
1033
1034		/*
1035		 * Don't update the neighbor cache entry on a proxy NA from
1036		 * ourselves because either the proxied node is off link or it
1037		 * has already sent a NA to us.
1038		 */
1039		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1040		    net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1041		    pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1042			/* XXX: idev->cnf.proxy_ndp */
1043			goto out;
1044		}
1045
1046		ndisc_update(dev, neigh, lladdr,
1047			     msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1048			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1049			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1050			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1051			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1052			     NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1053
1054		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1055			/*
1056			 * Change: router to host
1057			 */
1058			rt6_clean_tohost(dev_net(dev),  saddr);
 
 
 
1059		}
1060
1061out:
1062		neigh_release(neigh);
1063	}
1064}
1065
1066static void ndisc_recv_rs(struct sk_buff *skb)
1067{
1068	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1069	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1070	struct neighbour *neigh;
1071	struct inet6_dev *idev;
1072	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1073	struct ndisc_options ndopts;
1074	u8 *lladdr = NULL;
1075
1076	if (skb->len < sizeof(*rs_msg))
1077		return;
1078
1079	idev = __in6_dev_get(skb->dev);
1080	if (!idev) {
1081		ND_PRINTK(1, err, "RS: can't find in6 device\n");
 
1082		return;
1083	}
1084
1085	/* Don't accept RS if we're not in router mode */
1086	if (!idev->cnf.forwarding)
1087		goto out;
1088
1089	/*
1090	 * Don't update NCE if src = ::;
1091	 * this implies that the source node has no ip address assigned yet.
1092	 */
1093	if (ipv6_addr_any(saddr))
1094		goto out;
1095
1096	/* Parse ND options */
1097	if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1098		ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
 
1099		goto out;
1100	}
1101
1102	if (ndopts.nd_opts_src_lladdr) {
1103		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1104					     skb->dev);
1105		if (!lladdr)
1106			goto out;
1107	}
1108
1109	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1110	if (neigh) {
1111		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1112			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1113			     NEIGH_UPDATE_F_OVERRIDE|
1114			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1115			     NDISC_ROUTER_SOLICITATION, &ndopts);
1116		neigh_release(neigh);
1117	}
1118out:
1119	return;
1120}
1121
1122static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1123{
1124	struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1125	struct sk_buff *skb;
1126	struct nlmsghdr *nlh;
1127	struct nduseroptmsg *ndmsg;
1128	struct net *net = dev_net(ra->dev);
1129	int err;
1130	int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1131				    + (opt->nd_opt_len << 3));
1132	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1133
1134	skb = nlmsg_new(msg_size, GFP_ATOMIC);
1135	if (!skb) {
1136		err = -ENOBUFS;
1137		goto errout;
1138	}
1139
1140	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1141	if (!nlh) {
1142		goto nla_put_failure;
1143	}
1144
1145	ndmsg = nlmsg_data(nlh);
1146	ndmsg->nduseropt_family = AF_INET6;
1147	ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1148	ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1149	ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1150	ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1151
1152	memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1153
1154	if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1155		goto nla_put_failure;
1156	nlmsg_end(skb, nlh);
1157
1158	rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1159	return;
1160
1161nla_put_failure:
1162	nlmsg_free(skb);
1163	err = -EMSGSIZE;
1164errout:
1165	rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1166}
1167
 
 
 
 
 
 
 
 
 
 
 
 
1168static void ndisc_router_discovery(struct sk_buff *skb)
1169{
1170	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1171	struct neighbour *neigh = NULL;
1172	struct inet6_dev *in6_dev;
1173	struct fib6_info *rt = NULL;
1174	struct net *net;
1175	int lifetime;
1176	struct ndisc_options ndopts;
1177	int optlen;
1178	unsigned int pref = 0;
1179	__u32 old_if_flags;
1180	bool send_ifinfo_notify = false;
1181
1182	__u8 *opt = (__u8 *)(ra_msg + 1);
1183
1184	optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1185		sizeof(struct ra_msg);
1186
1187	ND_PRINTK(2, info,
1188		  "RA: %s, dev: %s\n",
1189		  __func__, skb->dev->name);
1190	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1191		ND_PRINTK(2, warn, "RA: source address is not link-local\n");
 
1192		return;
1193	}
1194	if (optlen < 0) {
1195		ND_PRINTK(2, warn, "RA: packet too short\n");
 
1196		return;
1197	}
1198
1199#ifdef CONFIG_IPV6_NDISC_NODETYPE
1200	if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1201		ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
 
1202		return;
1203	}
1204#endif
1205
1206	/*
1207	 *	set the RA_RECV flag in the interface
1208	 */
1209
1210	in6_dev = __in6_dev_get(skb->dev);
1211	if (!in6_dev) {
1212		ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1213			  skb->dev->name);
 
1214		return;
1215	}
1216
1217	if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1218		ND_PRINTK(2, warn, "RA: invalid ND options\n");
 
 
1219		return;
1220	}
1221
1222	if (!ipv6_accept_ra(in6_dev)) {
1223		ND_PRINTK(2, info,
1224			  "RA: %s, did not accept ra for dev: %s\n",
1225			  __func__, skb->dev->name);
1226		goto skip_linkparms;
1227	}
1228
1229#ifdef CONFIG_IPV6_NDISC_NODETYPE
1230	/* skip link-specific parameters from interior routers */
1231	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1232		ND_PRINTK(2, info,
1233			  "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1234			  __func__, skb->dev->name);
1235		goto skip_linkparms;
1236	}
1237#endif
1238
1239	if (in6_dev->if_flags & IF_RS_SENT) {
1240		/*
1241		 *	flag that an RA was received after an RS was sent
1242		 *	out on this interface.
1243		 */
1244		in6_dev->if_flags |= IF_RA_RCVD;
1245	}
1246
1247	/*
1248	 * Remember the managed/otherconf flags from most recently
1249	 * received RA message (RFC 2462) -- yoshfuji
1250	 */
1251	old_if_flags = in6_dev->if_flags;
1252	in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1253				IF_RA_OTHERCONF)) |
1254				(ra_msg->icmph.icmp6_addrconf_managed ?
1255					IF_RA_MANAGED : 0) |
1256				(ra_msg->icmph.icmp6_addrconf_other ?
1257					IF_RA_OTHERCONF : 0);
1258
1259	if (old_if_flags != in6_dev->if_flags)
1260		send_ifinfo_notify = true;
1261
1262	if (!in6_dev->cnf.accept_ra_defrtr) {
1263		ND_PRINTK(2, info,
1264			  "RA: %s, defrtr is false for dev: %s\n",
1265			  __func__, skb->dev->name);
1266		goto skip_defrtr;
1267	}
1268
1269	/* Do not accept RA with source-addr found on local machine unless
1270	 * accept_ra_from_local is set to true.
1271	 */
1272	net = dev_net(in6_dev->dev);
1273	if (!in6_dev->cnf.accept_ra_from_local &&
1274	    ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1275		ND_PRINTK(2, info,
1276			  "RA from local address detected on dev: %s: default router ignored\n",
1277			  skb->dev->name);
1278		goto skip_defrtr;
1279	}
1280
1281	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1282
1283#ifdef CONFIG_IPV6_ROUTER_PREF
1284	pref = ra_msg->icmph.icmp6_router_pref;
1285	/* 10b is handled as if it were 00b (medium) */
1286	if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1287	    !in6_dev->cnf.accept_ra_rtr_pref)
1288		pref = ICMPV6_ROUTER_PREF_MEDIUM;
1289#endif
1290	/* routes added from RAs do not use nexthop objects */
1291	rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1292	if (rt) {
1293		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1294					 rt->fib6_nh->fib_nh_dev, NULL,
1295					  &ipv6_hdr(skb)->saddr);
1296		if (!neigh) {
1297			ND_PRINTK(0, err,
1298				  "RA: %s got default router without neighbour\n",
1299				  __func__);
1300			fib6_info_release(rt);
1301			return;
1302		}
1303	}
1304	if (rt && lifetime == 0) {
1305		ip6_del_rt(net, rt, false);
 
1306		rt = NULL;
1307	}
1308
1309	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, for dev: %s\n",
1310		  rt, lifetime, skb->dev->name);
1311	if (!rt && lifetime) {
1312		ND_PRINTK(3, info, "RA: adding default router\n");
1313
1314		rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1315					 skb->dev, pref);
1316		if (!rt) {
1317			ND_PRINTK(0, err,
1318				  "RA: %s failed to add default route\n",
1319				  __func__);
1320			return;
1321		}
1322
1323		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1324					 rt->fib6_nh->fib_nh_dev, NULL,
1325					  &ipv6_hdr(skb)->saddr);
1326		if (!neigh) {
1327			ND_PRINTK(0, err,
1328				  "RA: %s got default router without neighbour\n",
1329				  __func__);
1330			fib6_info_release(rt);
1331			return;
1332		}
1333		neigh->flags |= NTF_ROUTER;
1334	} else if (rt) {
1335		rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1336	}
1337
1338	if (rt)
1339		fib6_set_expires(rt, jiffies + (HZ * lifetime));
1340	if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1341	    ra_msg->icmph.icmp6_hop_limit) {
1342		if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1343			in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1344			fib6_metric_set(rt, RTAX_HOPLIMIT,
1345					ra_msg->icmph.icmp6_hop_limit);
1346		} else {
1347			ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1348		}
1349	}
1350
1351skip_defrtr:
1352
1353	/*
1354	 *	Update Reachable Time and Retrans Timer
1355	 */
1356
1357	if (in6_dev->nd_parms) {
1358		unsigned long rtime = ntohl(ra_msg->retrans_timer);
1359
1360		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1361			rtime = (rtime*HZ)/1000;
1362			if (rtime < HZ/100)
1363				rtime = HZ/100;
1364			NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1365			in6_dev->tstamp = jiffies;
1366			send_ifinfo_notify = true;
1367		}
1368
1369		rtime = ntohl(ra_msg->reachable_time);
1370		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1371			rtime = (rtime*HZ)/1000;
1372
1373			if (rtime < HZ/10)
1374				rtime = HZ/10;
1375
1376			if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1377				NEIGH_VAR_SET(in6_dev->nd_parms,
1378					      BASE_REACHABLE_TIME, rtime);
1379				NEIGH_VAR_SET(in6_dev->nd_parms,
1380					      GC_STALETIME, 3 * rtime);
1381				in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1382				in6_dev->tstamp = jiffies;
1383				send_ifinfo_notify = true;
1384			}
1385		}
1386	}
1387
1388	/*
1389	 *	Send a notify if RA changed managed/otherconf flags or timer settings
1390	 */
1391	if (send_ifinfo_notify)
1392		inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1393
1394skip_linkparms:
1395
1396	/*
1397	 *	Process options.
1398	 */
1399
1400	if (!neigh)
1401		neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1402				       skb->dev, 1);
1403	if (neigh) {
1404		u8 *lladdr = NULL;
1405		if (ndopts.nd_opts_src_lladdr) {
1406			lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1407						     skb->dev);
1408			if (!lladdr) {
1409				ND_PRINTK(2, warn,
1410					  "RA: invalid link-layer address length\n");
1411				goto out;
1412			}
1413		}
1414		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1415			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1416			     NEIGH_UPDATE_F_OVERRIDE|
1417			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1418			     NEIGH_UPDATE_F_ISROUTER,
1419			     NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1420	}
1421
1422	if (!ipv6_accept_ra(in6_dev)) {
1423		ND_PRINTK(2, info,
1424			  "RA: %s, accept_ra is false for dev: %s\n",
1425			  __func__, skb->dev->name);
1426		goto out;
1427	}
1428
1429#ifdef CONFIG_IPV6_ROUTE_INFO
1430	if (!in6_dev->cnf.accept_ra_from_local &&
1431	    ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1432			  in6_dev->dev, 0)) {
1433		ND_PRINTK(2, info,
1434			  "RA from local address detected on dev: %s: router info ignored.\n",
1435			  skb->dev->name);
1436		goto skip_routeinfo;
1437	}
1438
1439	if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1440		struct nd_opt_hdr *p;
1441		for (p = ndopts.nd_opts_ri;
1442		     p;
1443		     p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1444			struct route_info *ri = (struct route_info *)p;
1445#ifdef CONFIG_IPV6_NDISC_NODETYPE
1446			if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1447			    ri->prefix_len == 0)
1448				continue;
1449#endif
1450			if (ri->prefix_len == 0 &&
1451			    !in6_dev->cnf.accept_ra_defrtr)
1452				continue;
1453			if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1454				continue;
1455			if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1456				continue;
1457			rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1458				      &ipv6_hdr(skb)->saddr);
1459		}
1460	}
1461
1462skip_routeinfo:
1463#endif
1464
1465#ifdef CONFIG_IPV6_NDISC_NODETYPE
1466	/* skip link-specific ndopts from interior routers */
1467	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1468		ND_PRINTK(2, info,
1469			  "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1470			  __func__, skb->dev->name);
1471		goto out;
1472	}
1473#endif
1474
1475	if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1476		struct nd_opt_hdr *p;
1477		for (p = ndopts.nd_opts_pi;
1478		     p;
1479		     p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1480			addrconf_prefix_rcv(skb->dev, (u8 *)p,
1481					    (p->nd_opt_len) << 3,
1482					    ndopts.nd_opts_src_lladdr != NULL);
1483		}
1484	}
1485
1486	if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1487		__be32 n;
1488		u32 mtu;
1489
1490		memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1491		mtu = ntohl(n);
1492
1493		if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1494			ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
 
 
1495		} else if (in6_dev->cnf.mtu6 != mtu) {
1496			in6_dev->cnf.mtu6 = mtu;
1497			fib6_metric_set(rt, RTAX_MTU, mtu);
 
 
 
1498			rt6_mtu_change(skb->dev, mtu);
1499		}
1500	}
1501
1502	if (ndopts.nd_useropts) {
1503		struct nd_opt_hdr *p;
1504		for (p = ndopts.nd_useropts;
1505		     p;
1506		     p = ndisc_next_useropt(skb->dev, p,
1507					    ndopts.nd_useropts_end)) {
1508			ndisc_ra_useropt(skb, p);
1509		}
1510	}
1511
1512	if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1513		ND_PRINTK(2, warn, "RA: invalid RA options\n");
 
1514	}
1515out:
1516	fib6_info_release(rt);
1517	if (neigh)
 
1518		neigh_release(neigh);
 
1519}
1520
1521static void ndisc_redirect_rcv(struct sk_buff *skb)
1522{
1523	u8 *hdr;
 
 
 
 
 
1524	struct ndisc_options ndopts;
1525	struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1526	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1527				    offsetof(struct rd_msg, opt));
1528
1529#ifdef CONFIG_IPV6_NDISC_NODETYPE
1530	switch (skb->ndisc_nodetype) {
1531	case NDISC_NODETYPE_HOST:
1532	case NDISC_NODETYPE_NODEFAULT:
1533		ND_PRINTK(2, warn,
1534			  "Redirect: from host or unauthorized router\n");
1535		return;
1536	}
1537#endif
1538
1539	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1540		ND_PRINTK(2, warn,
1541			  "Redirect: source address is not link-local\n");
1542		return;
1543	}
1544
1545	if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
 
 
 
 
 
1546		return;
 
 
 
 
 
1547
1548	if (!ndopts.nd_opts_rh) {
1549		ip6_redirect_no_header(skb, dev_net(skb->dev),
1550					skb->dev->ifindex);
1551		return;
1552	}
1553
1554	hdr = (u8 *)ndopts.nd_opts_rh;
1555	hdr += 8;
1556	if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
 
 
 
1557		return;
 
1558
1559	icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1560}
 
 
 
 
 
1561
1562static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1563					   struct sk_buff *orig_skb,
1564					   int rd_len)
1565{
1566	u8 *opt = skb_put(skb, rd_len);
1567
1568	memset(opt, 0, 8);
1569	*(opt++) = ND_OPT_REDIRECT_HDR;
1570	*(opt++) = (rd_len >> 3);
1571	opt += 6;
 
 
 
 
 
 
 
 
 
 
 
 
1572
1573	skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1574		      rd_len - 8);
 
 
 
 
 
 
1575}
1576
1577void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
 
1578{
1579	struct net_device *dev = skb->dev;
1580	struct net *net = dev_net(dev);
1581	struct sock *sk = net->ipv6.ndisc_sk;
1582	int optlen = 0;
1583	struct inet_peer *peer;
1584	struct sk_buff *buff;
1585	struct rd_msg *msg;
1586	struct in6_addr saddr_buf;
 
1587	struct rt6_info *rt;
1588	struct dst_entry *dst;
 
1589	struct flowi6 fl6;
 
1590	int rd_len;
1591	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1592	   ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1593	bool ret;
1594
1595	if (netif_is_l3_master(skb->dev)) {
1596		dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1597		if (!dev)
1598			return;
1599	}
1600
1601	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1602		ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1603			  dev->name);
 
1604		return;
1605	}
1606
1607	if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1608	    ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1609		ND_PRINTK(2, warn,
1610			  "Redirect: target address is not link-local unicast\n");
1611		return;
1612	}
1613
1614	icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1615			 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1616
1617	dst = ip6_route_output(net, NULL, &fl6);
1618	if (dst->error) {
1619		dst_release(dst);
1620		return;
1621	}
1622	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1623	if (IS_ERR(dst))
1624		return;
1625
1626	rt = (struct rt6_info *) dst;
1627
1628	if (rt->rt6i_flags & RTF_GATEWAY) {
1629		ND_PRINTK(2, warn,
1630			  "Redirect: destination is not a neighbour\n");
1631		goto release;
1632	}
1633	peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1634	ret = inet_peer_xrlim_allow(peer, 1*HZ);
1635	if (peer)
1636		inet_putpeer(peer);
1637	if (!ret)
1638		goto release;
1639
1640	if (dev->addr_len) {
1641		struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1642		if (!neigh) {
1643			ND_PRINTK(2, warn,
1644				  "Redirect: no neigh for target address\n");
1645			goto release;
1646		}
1647
1648		read_lock_bh(&neigh->lock);
1649		if (neigh->nud_state & NUD_VALID) {
1650			memcpy(ha_buf, neigh->ha, dev->addr_len);
1651			read_unlock_bh(&neigh->lock);
1652			ha = ha_buf;
1653			optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1654								ops_data_buf,
1655								&ops_data);
1656		} else
1657			read_unlock_bh(&neigh->lock);
1658
1659		neigh_release(neigh);
1660	}
1661
1662	rd_len = min_t(unsigned int,
1663		       IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1664		       skb->len + 8);
1665	rd_len &= ~0x7;
1666	optlen += rd_len;
1667
1668	buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1669	if (!buff)
 
 
 
 
 
 
1670		goto release;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1671
1672	msg = skb_put(buff, sizeof(*msg));
1673	*msg = (struct rd_msg) {
1674		.icmph = {
1675			.icmp6_type = NDISC_REDIRECT,
1676		},
1677		.target = *target,
1678		.dest = ipv6_hdr(skb)->daddr,
1679	};
1680
1681	/*
1682	 *	include target_address option
1683	 */
1684
1685	if (ha)
1686		ndisc_fill_redirect_addr_option(buff, ha, ops_data);
 
1687
1688	/*
1689	 *	build redirect option and copy skb over to the new packet.
1690	 */
1691
1692	if (rd_len)
1693		ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
 
 
 
 
 
 
 
 
1694
1695	skb_dst_set(buff, dst);
1696	ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
 
 
 
 
 
 
 
 
 
 
1697	return;
1698
1699release:
1700	dst_release(dst);
1701}
1702
1703static void pndisc_redo(struct sk_buff *skb)
1704{
1705	ndisc_recv_ns(skb);
1706	kfree_skb(skb);
1707}
1708
1709static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1710{
1711	struct inet6_dev *idev = __in6_dev_get(skb->dev);
1712
1713	if (!idev)
1714		return true;
1715	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1716	    idev->cnf.suppress_frag_ndisc) {
1717		net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1718		return true;
1719	}
1720	return false;
1721}
1722
1723int ndisc_rcv(struct sk_buff *skb)
1724{
1725	struct nd_msg *msg;
1726
1727	if (ndisc_suppress_frag_ndisc(skb))
1728		return 0;
1729
1730	if (skb_linearize(skb))
1731		return 0;
1732
1733	msg = (struct nd_msg *)skb_transport_header(skb);
1734
1735	__skb_push(skb, skb->data - skb_transport_header(skb));
1736
1737	if (ipv6_hdr(skb)->hop_limit != 255) {
1738		ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1739			  ipv6_hdr(skb)->hop_limit);
 
1740		return 0;
1741	}
1742
1743	if (msg->icmph.icmp6_code != 0) {
1744		ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1745			  msg->icmph.icmp6_code);
 
1746		return 0;
1747	}
1748
 
 
1749	switch (msg->icmph.icmp6_type) {
1750	case NDISC_NEIGHBOUR_SOLICITATION:
1751		memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1752		ndisc_recv_ns(skb);
1753		break;
1754
1755	case NDISC_NEIGHBOUR_ADVERTISEMENT:
1756		ndisc_recv_na(skb);
1757		break;
1758
1759	case NDISC_ROUTER_SOLICITATION:
1760		ndisc_recv_rs(skb);
1761		break;
1762
1763	case NDISC_ROUTER_ADVERTISEMENT:
1764		ndisc_router_discovery(skb);
1765		break;
1766
1767	case NDISC_REDIRECT:
1768		ndisc_redirect_rcv(skb);
1769		break;
1770	}
1771
1772	return 0;
1773}
1774
1775static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1776{
1777	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1778	struct netdev_notifier_change_info *change_info;
1779	struct net *net = dev_net(dev);
1780	struct inet6_dev *idev;
1781
1782	switch (event) {
1783	case NETDEV_CHANGEADDR:
1784		neigh_changeaddr(&nd_tbl, dev);
1785		fib6_run_gc(0, net, false);
1786		fallthrough;
1787	case NETDEV_UP:
1788		idev = in6_dev_get(dev);
1789		if (!idev)
1790			break;
1791		if (idev->cnf.ndisc_notify ||
1792		    net->ipv6.devconf_all->ndisc_notify)
1793			ndisc_send_unsol_na(dev);
1794		in6_dev_put(idev);
1795		break;
1796	case NETDEV_CHANGE:
1797		change_info = ptr;
1798		if (change_info->flags_changed & IFF_NOARP)
1799			neigh_changeaddr(&nd_tbl, dev);
1800		if (!netif_carrier_ok(dev))
1801			neigh_carrier_down(&nd_tbl, dev);
1802		break;
1803	case NETDEV_DOWN:
1804		neigh_ifdown(&nd_tbl, dev);
1805		fib6_run_gc(0, net, false);
1806		break;
1807	case NETDEV_NOTIFY_PEERS:
1808		ndisc_send_unsol_na(dev);
1809		break;
1810	default:
1811		break;
1812	}
1813
1814	return NOTIFY_DONE;
1815}
1816
1817static struct notifier_block ndisc_netdev_notifier = {
1818	.notifier_call = ndisc_netdev_event,
1819	.priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1820};
1821
1822#ifdef CONFIG_SYSCTL
1823static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1824					 const char *func, const char *dev_name)
1825{
1826	static char warncomm[TASK_COMM_LEN];
1827	static int warned;
1828	if (strcmp(warncomm, current->comm) && warned < 5) {
1829		strcpy(warncomm, current->comm);
1830		pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
 
 
 
 
1831			warncomm, func,
1832			dev_name, ctl->procname,
1833			dev_name, ctl->procname);
1834		warned++;
1835	}
1836}
1837
1838int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1839		size_t *lenp, loff_t *ppos)
1840{
1841	struct net_device *dev = ctl->extra1;
1842	struct inet6_dev *idev;
1843	int ret;
1844
1845	if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1846	    (strcmp(ctl->procname, "base_reachable_time") == 0))
1847		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1848
1849	if (strcmp(ctl->procname, "retrans_time") == 0)
1850		ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1851
1852	else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1853		ret = neigh_proc_dointvec_jiffies(ctl, write,
1854						  buffer, lenp, ppos);
1855
1856	else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1857		 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1858		ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1859						     buffer, lenp, ppos);
1860	else
1861		ret = -1;
1862
1863	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1864		if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1865			idev->nd_parms->reachable_time =
1866					neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1867		idev->tstamp = jiffies;
1868		inet6_ifinfo_notify(RTM_NEWLINK, idev);
1869		in6_dev_put(idev);
1870	}
1871	return ret;
1872}
1873
1874
1875#endif
1876
1877static int __net_init ndisc_net_init(struct net *net)
1878{
1879	struct ipv6_pinfo *np;
1880	struct sock *sk;
1881	int err;
1882
1883	err = inet_ctl_sock_create(&sk, PF_INET6,
1884				   SOCK_RAW, IPPROTO_ICMPV6, net);
1885	if (err < 0) {
1886		ND_PRINTK(0, err,
1887			  "NDISC: Failed to initialize the control socket (err %d)\n",
1888			  err);
1889		return err;
1890	}
1891
1892	net->ipv6.ndisc_sk = sk;
1893
1894	np = inet6_sk(sk);
1895	np->hop_limit = 255;
1896	/* Do not loopback ndisc messages */
1897	np->mc_loop = 0;
1898
1899	return 0;
1900}
1901
1902static void __net_exit ndisc_net_exit(struct net *net)
1903{
1904	inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1905}
1906
1907static struct pernet_operations ndisc_net_ops = {
1908	.init = ndisc_net_init,
1909	.exit = ndisc_net_exit,
1910};
1911
1912int __init ndisc_init(void)
1913{
1914	int err;
1915
1916	err = register_pernet_subsys(&ndisc_net_ops);
1917	if (err)
1918		return err;
1919	/*
1920	 * Initialize the neighbour table
1921	 */
1922	neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1923
1924#ifdef CONFIG_SYSCTL
1925	err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1926				    ndisc_ifinfo_sysctl_change);
1927	if (err)
1928		goto out_unregister_pernet;
 
 
 
 
1929out:
1930#endif
1931	return err;
1932
 
1933#ifdef CONFIG_SYSCTL
 
1934out_unregister_pernet:
 
1935	unregister_pernet_subsys(&ndisc_net_ops);
1936	goto out;
1937#endif
1938}
1939
1940int __init ndisc_late_init(void)
1941{
1942	return register_netdevice_notifier(&ndisc_netdev_notifier);
1943}
1944
1945void ndisc_late_cleanup(void)
1946{
1947	unregister_netdevice_notifier(&ndisc_netdev_notifier);
1948}
1949
1950void ndisc_cleanup(void)
1951{
1952#ifdef CONFIG_SYSCTL
1953	neigh_sysctl_unregister(&nd_tbl.parms);
1954#endif
1955	neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1956	unregister_pernet_subsys(&ndisc_net_ops);
1957}