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v4.17
 
   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 *	Alexey I. Froloff		:	RFC6106 (DNSSL) support
  19 *	Pierre Ynard			:	export userland ND options
  20 *						through netlink (RDNSS support)
  21 *	Lars Fenneberg			:	fixed MTU setting on receipt
  22 *						of an RA.
  23 *	Janos Farkas			:	kmalloc failure checks
  24 *	Alexey Kuznetsov		:	state machine reworked
  25 *						and moved to net/core.
  26 *	Pekka Savola			:	RFC2461 validation
  27 *	YOSHIFUJI Hideaki @USAGI	:	Verify ND options properly
  28 */
  29
  30#define pr_fmt(fmt) "ICMPv6: " fmt
  31
  32#include <linux/module.h>
  33#include <linux/errno.h>
  34#include <linux/types.h>
  35#include <linux/socket.h>
  36#include <linux/sockios.h>
  37#include <linux/sched.h>
  38#include <linux/net.h>
  39#include <linux/in6.h>
  40#include <linux/route.h>
  41#include <linux/init.h>
  42#include <linux/rcupdate.h>
  43#include <linux/slab.h>
  44#ifdef CONFIG_SYSCTL
  45#include <linux/sysctl.h>
  46#endif
  47
  48#include <linux/if_addr.h>
  49#include <linux/if_ether.h>
  50#include <linux/if_arp.h>
  51#include <linux/ipv6.h>
  52#include <linux/icmpv6.h>
  53#include <linux/jhash.h>
  54
  55#include <net/sock.h>
  56#include <net/snmp.h>
  57
  58#include <net/ipv6.h>
  59#include <net/protocol.h>
  60#include <net/ndisc.h>
  61#include <net/ip6_route.h>
  62#include <net/addrconf.h>
  63#include <net/icmp.h>
  64
  65#include <net/netlink.h>
  66#include <linux/rtnetlink.h>
  67
  68#include <net/flow.h>
  69#include <net/ip6_checksum.h>
  70#include <net/inet_common.h>
  71#include <linux/proc_fs.h>
  72
  73#include <linux/netfilter.h>
  74#include <linux/netfilter_ipv6.h>
  75
  76static u32 ndisc_hash(const void *pkey,
  77		      const struct net_device *dev,
  78		      __u32 *hash_rnd);
  79static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
 
 
  80static int ndisc_constructor(struct neighbour *neigh);
  81static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  82static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  83static int pndisc_constructor(struct pneigh_entry *n);
  84static void pndisc_destructor(struct pneigh_entry *n);
  85static void pndisc_redo(struct sk_buff *skb);
 
  86
  87static const struct neigh_ops ndisc_generic_ops = {
  88	.family =		AF_INET6,
  89	.solicit =		ndisc_solicit,
  90	.error_report =		ndisc_error_report,
  91	.output =		neigh_resolve_output,
  92	.connected_output =	neigh_connected_output,
  93};
  94
  95static const struct neigh_ops ndisc_hh_ops = {
  96	.family =		AF_INET6,
  97	.solicit =		ndisc_solicit,
  98	.error_report =		ndisc_error_report,
  99	.output =		neigh_resolve_output,
 100	.connected_output =	neigh_resolve_output,
 101};
 102
 103
 104static const struct neigh_ops ndisc_direct_ops = {
 105	.family =		AF_INET6,
 106	.output =		neigh_direct_output,
 107	.connected_output =	neigh_direct_output,
 108};
 109
 110struct neigh_table nd_tbl = {
 111	.family =	AF_INET6,
 112	.key_len =	sizeof(struct in6_addr),
 113	.protocol =	cpu_to_be16(ETH_P_IPV6),
 114	.hash =		ndisc_hash,
 115	.key_eq =	ndisc_key_eq,
 116	.constructor =	ndisc_constructor,
 117	.pconstructor =	pndisc_constructor,
 118	.pdestructor =	pndisc_destructor,
 119	.proxy_redo =	pndisc_redo,
 
 
 120	.id =		"ndisc_cache",
 121	.parms = {
 122		.tbl			= &nd_tbl,
 123		.reachable_time		= ND_REACHABLE_TIME,
 124		.data = {
 125			[NEIGH_VAR_MCAST_PROBES] = 3,
 126			[NEIGH_VAR_UCAST_PROBES] = 3,
 127			[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
 128			[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
 129			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
 
 130			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 131			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 132			[NEIGH_VAR_PROXY_QLEN] = 64,
 133			[NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
 134			[NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
 135		},
 136	},
 137	.gc_interval =	  30 * HZ,
 138	.gc_thresh1 =	 128,
 139	.gc_thresh2 =	 512,
 140	.gc_thresh3 =	1024,
 141};
 142EXPORT_SYMBOL_GPL(nd_tbl);
 143
 144void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 145			      int data_len, int pad)
 146{
 147	int space = __ndisc_opt_addr_space(data_len, pad);
 148	u8 *opt = skb_put(skb, space);
 149
 150	opt[0] = type;
 151	opt[1] = space>>3;
 152
 153	memset(opt + 2, 0, pad);
 154	opt   += pad;
 155	space -= pad;
 156
 157	memcpy(opt+2, data, data_len);
 158	data_len += 2;
 159	opt += data_len;
 160	space -= data_len;
 161	if (space > 0)
 162		memset(opt, 0, space);
 163}
 164EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
 165
 166static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
 167					  void *data, u8 icmp6_type)
 168{
 169	__ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
 170				 ndisc_addr_option_pad(skb->dev->type));
 171	ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
 172}
 173
 174static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
 175						   void *ha,
 176						   const u8 *ops_data)
 177{
 178	ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
 179	ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
 180}
 181
 182static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 183					    struct nd_opt_hdr *end)
 184{
 185	int type;
 186	if (!cur || !end || cur >= end)
 187		return NULL;
 188	type = cur->nd_opt_type;
 189	do {
 190		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 191	} while (cur < end && cur->nd_opt_type != type);
 192	return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 193}
 194
 195static inline int ndisc_is_useropt(const struct net_device *dev,
 196				   struct nd_opt_hdr *opt)
 197{
 198	return opt->nd_opt_type == ND_OPT_RDNSS ||
 199		opt->nd_opt_type == ND_OPT_DNSSL ||
 
 
 200		ndisc_ops_is_useropt(dev, opt->nd_opt_type);
 201}
 202
 203static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
 204					     struct nd_opt_hdr *cur,
 205					     struct nd_opt_hdr *end)
 206{
 207	if (!cur || !end || cur >= end)
 208		return NULL;
 209	do {
 210		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 211	} while (cur < end && !ndisc_is_useropt(dev, cur));
 212	return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
 213}
 214
 215struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 216					  u8 *opt, int opt_len,
 217					  struct ndisc_options *ndopts)
 218{
 219	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 220
 221	if (!nd_opt || opt_len < 0 || !ndopts)
 222		return NULL;
 223	memset(ndopts, 0, sizeof(*ndopts));
 224	while (opt_len) {
 225		int l;
 226		if (opt_len < sizeof(struct nd_opt_hdr))
 227			return NULL;
 228		l = nd_opt->nd_opt_len << 3;
 229		if (opt_len < l || l == 0)
 230			return NULL;
 231		if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
 232			goto next_opt;
 233		switch (nd_opt->nd_opt_type) {
 234		case ND_OPT_SOURCE_LL_ADDR:
 235		case ND_OPT_TARGET_LL_ADDR:
 236		case ND_OPT_MTU:
 237		case ND_OPT_NONCE:
 238		case ND_OPT_REDIRECT_HDR:
 239			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 240				ND_PRINTK(2, warn,
 241					  "%s: duplicated ND6 option found: type=%d\n",
 242					  __func__, nd_opt->nd_opt_type);
 243			} else {
 244				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 245			}
 246			break;
 247		case ND_OPT_PREFIX_INFO:
 248			ndopts->nd_opts_pi_end = nd_opt;
 249			if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 250				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 251			break;
 252#ifdef CONFIG_IPV6_ROUTE_INFO
 253		case ND_OPT_ROUTE_INFO:
 254			ndopts->nd_opts_ri_end = nd_opt;
 255			if (!ndopts->nd_opts_ri)
 256				ndopts->nd_opts_ri = nd_opt;
 257			break;
 258#endif
 259		default:
 260			if (ndisc_is_useropt(dev, nd_opt)) {
 261				ndopts->nd_useropts_end = nd_opt;
 262				if (!ndopts->nd_useropts)
 263					ndopts->nd_useropts = nd_opt;
 264			} else {
 265				/*
 266				 * Unknown options must be silently ignored,
 267				 * to accommodate future extension to the
 268				 * protocol.
 269				 */
 270				ND_PRINTK(2, notice,
 271					  "%s: ignored unsupported option; type=%d, len=%d\n",
 272					  __func__,
 273					  nd_opt->nd_opt_type,
 274					  nd_opt->nd_opt_len);
 275			}
 276		}
 277next_opt:
 278		opt_len -= l;
 279		nd_opt = ((void *)nd_opt) + l;
 280	}
 281	return ndopts;
 282}
 283
 284int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 285{
 286	switch (dev->type) {
 287	case ARPHRD_ETHER:
 288	case ARPHRD_IEEE802:	/* Not sure. Check it later. --ANK */
 289	case ARPHRD_FDDI:
 290		ipv6_eth_mc_map(addr, buf);
 291		return 0;
 292	case ARPHRD_ARCNET:
 293		ipv6_arcnet_mc_map(addr, buf);
 294		return 0;
 295	case ARPHRD_INFINIBAND:
 296		ipv6_ib_mc_map(addr, dev->broadcast, buf);
 297		return 0;
 298	case ARPHRD_IPGRE:
 299		return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 300	default:
 301		if (dir) {
 302			memcpy(buf, dev->broadcast, dev->addr_len);
 303			return 0;
 304		}
 305	}
 306	return -EINVAL;
 307}
 308EXPORT_SYMBOL(ndisc_mc_map);
 309
 310static u32 ndisc_hash(const void *pkey,
 311		      const struct net_device *dev,
 312		      __u32 *hash_rnd)
 313{
 314	return ndisc_hashfn(pkey, dev, hash_rnd);
 315}
 316
 317static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
 318{
 319	return neigh_key_eq128(n, pkey);
 320}
 321
 322static int ndisc_constructor(struct neighbour *neigh)
 323{
 324	struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
 325	struct net_device *dev = neigh->dev;
 326	struct inet6_dev *in6_dev;
 327	struct neigh_parms *parms;
 328	bool is_multicast = ipv6_addr_is_multicast(addr);
 329
 330	in6_dev = in6_dev_get(dev);
 331	if (!in6_dev) {
 332		return -EINVAL;
 333	}
 334
 335	parms = in6_dev->nd_parms;
 336	__neigh_parms_put(neigh->parms);
 337	neigh->parms = neigh_parms_clone(parms);
 338
 339	neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 340	if (!dev->header_ops) {
 341		neigh->nud_state = NUD_NOARP;
 342		neigh->ops = &ndisc_direct_ops;
 343		neigh->output = neigh_direct_output;
 344	} else {
 345		if (is_multicast) {
 346			neigh->nud_state = NUD_NOARP;
 347			ndisc_mc_map(addr, neigh->ha, dev, 1);
 348		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 349			neigh->nud_state = NUD_NOARP;
 350			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 351			if (dev->flags&IFF_LOOPBACK)
 352				neigh->type = RTN_LOCAL;
 353		} else if (dev->flags&IFF_POINTOPOINT) {
 354			neigh->nud_state = NUD_NOARP;
 355			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 356		}
 357		if (dev->header_ops->cache)
 358			neigh->ops = &ndisc_hh_ops;
 359		else
 360			neigh->ops = &ndisc_generic_ops;
 361		if (neigh->nud_state&NUD_VALID)
 362			neigh->output = neigh->ops->connected_output;
 363		else
 364			neigh->output = neigh->ops->output;
 365	}
 366	in6_dev_put(in6_dev);
 367	return 0;
 368}
 369
 370static int pndisc_constructor(struct pneigh_entry *n)
 371{
 372	struct in6_addr *addr = (struct in6_addr *)&n->key;
 373	struct in6_addr maddr;
 374	struct net_device *dev = n->dev;
 375
 376	if (!dev || !__in6_dev_get(dev))
 377		return -EINVAL;
 378	addrconf_addr_solict_mult(addr, &maddr);
 379	ipv6_dev_mc_inc(dev, &maddr);
 380	return 0;
 381}
 382
 383static void pndisc_destructor(struct pneigh_entry *n)
 384{
 385	struct in6_addr *addr = (struct in6_addr *)&n->key;
 386	struct in6_addr maddr;
 387	struct net_device *dev = n->dev;
 388
 389	if (!dev || !__in6_dev_get(dev))
 390		return;
 391	addrconf_addr_solict_mult(addr, &maddr);
 392	ipv6_dev_mc_dec(dev, &maddr);
 393}
 394
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 395static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 396				       int len)
 397{
 398	int hlen = LL_RESERVED_SPACE(dev);
 399	int tlen = dev->needed_tailroom;
 400	struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
 401	struct sk_buff *skb;
 402
 403	skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
 404	if (!skb) {
 405		ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
 406			  __func__);
 407		return NULL;
 408	}
 409
 410	skb->protocol = htons(ETH_P_IPV6);
 411	skb->dev = dev;
 412
 413	skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
 414	skb_reset_transport_header(skb);
 415
 416	/* Manually assign socket ownership as we avoid calling
 417	 * sock_alloc_send_pskb() to bypass wmem buffer limits
 418	 */
 419	skb_set_owner_w(skb, sk);
 420
 421	return skb;
 422}
 423
 424static void ip6_nd_hdr(struct sk_buff *skb,
 425		       const struct in6_addr *saddr,
 426		       const struct in6_addr *daddr,
 427		       int hop_limit, int len)
 428{
 429	struct ipv6hdr *hdr;
 430	struct inet6_dev *idev;
 431	unsigned tclass;
 432
 433	rcu_read_lock();
 434	idev = __in6_dev_get(skb->dev);
 435	tclass = idev ? idev->cnf.ndisc_tclass : 0;
 436	rcu_read_unlock();
 437
 438	skb_push(skb, sizeof(*hdr));
 439	skb_reset_network_header(skb);
 440	hdr = ipv6_hdr(skb);
 441
 442	ip6_flow_hdr(hdr, tclass, 0);
 443
 444	hdr->payload_len = htons(len);
 445	hdr->nexthdr = IPPROTO_ICMPV6;
 446	hdr->hop_limit = hop_limit;
 447
 448	hdr->saddr = *saddr;
 449	hdr->daddr = *daddr;
 450}
 451
 452static void ndisc_send_skb(struct sk_buff *skb,
 453			   const struct in6_addr *daddr,
 454			   const struct in6_addr *saddr)
 455{
 456	struct dst_entry *dst = skb_dst(skb);
 457	struct net *net = dev_net(skb->dev);
 458	struct sock *sk = net->ipv6.ndisc_sk;
 459	struct inet6_dev *idev;
 460	int err;
 461	struct icmp6hdr *icmp6h = icmp6_hdr(skb);
 462	u8 type;
 463
 464	type = icmp6h->icmp6_type;
 465
 466	if (!dst) {
 467		struct flowi6 fl6;
 468		int oif = skb->dev->ifindex;
 469
 470		icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
 471		dst = icmp6_dst_alloc(skb->dev, &fl6);
 472		if (IS_ERR(dst)) {
 473			kfree_skb(skb);
 474			return;
 475		}
 476
 477		skb_dst_set(skb, dst);
 478	}
 479
 480	icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
 481					      IPPROTO_ICMPV6,
 482					      csum_partial(icmp6h,
 483							   skb->len, 0));
 484
 485	ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
 486
 487	rcu_read_lock();
 488	idev = __in6_dev_get(dst->dev);
 489	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 490
 491	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
 492		      net, sk, skb, NULL, dst->dev,
 493		      dst_output);
 494	if (!err) {
 495		ICMP6MSGOUT_INC_STATS(net, idev, type);
 496		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 497	}
 498
 499	rcu_read_unlock();
 500}
 
 501
 502void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 503		   const struct in6_addr *solicited_addr,
 504		   bool router, bool solicited, bool override, bool inc_opt)
 505{
 506	struct sk_buff *skb;
 507	struct in6_addr tmpaddr;
 508	struct inet6_ifaddr *ifp;
 509	const struct in6_addr *src_addr;
 510	struct nd_msg *msg;
 511	int optlen = 0;
 512
 513	/* for anycast or proxy, solicited_addr != src_addr */
 514	ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 515	if (ifp) {
 516		src_addr = solicited_addr;
 517		if (ifp->flags & IFA_F_OPTIMISTIC)
 518			override = false;
 519		inc_opt |= ifp->idev->cnf.force_tllao;
 520		in6_ifa_put(ifp);
 521	} else {
 522		if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 523				       inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 524				       &tmpaddr))
 525			return;
 526		src_addr = &tmpaddr;
 527	}
 528
 529	if (!dev->addr_len)
 530		inc_opt = false;
 531	if (inc_opt)
 532		optlen += ndisc_opt_addr_space(dev,
 533					       NDISC_NEIGHBOUR_ADVERTISEMENT);
 534
 535	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 536	if (!skb)
 537		return;
 538
 539	msg = skb_put(skb, sizeof(*msg));
 540	*msg = (struct nd_msg) {
 541		.icmph = {
 542			.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 543			.icmp6_router = router,
 544			.icmp6_solicited = solicited,
 545			.icmp6_override = override,
 546		},
 547		.target = *solicited_addr,
 548	};
 549
 550	if (inc_opt)
 551		ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 552				       dev->dev_addr,
 553				       NDISC_NEIGHBOUR_ADVERTISEMENT);
 554
 555	ndisc_send_skb(skb, daddr, src_addr);
 556}
 557
 558static void ndisc_send_unsol_na(struct net_device *dev)
 559{
 560	struct inet6_dev *idev;
 561	struct inet6_ifaddr *ifa;
 562
 563	idev = in6_dev_get(dev);
 564	if (!idev)
 565		return;
 566
 567	read_lock_bh(&idev->lock);
 568	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 569		/* skip tentative addresses until dad completes */
 570		if (ifa->flags & IFA_F_TENTATIVE &&
 571		    !(ifa->flags & IFA_F_OPTIMISTIC))
 572			continue;
 573
 574		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
 575			      /*router=*/ !!idev->cnf.forwarding,
 576			      /*solicited=*/ false, /*override=*/ true,
 577			      /*inc_opt=*/ true);
 578	}
 579	read_unlock_bh(&idev->lock);
 580
 581	in6_dev_put(idev);
 582}
 583
 584void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 585		   const struct in6_addr *daddr, const struct in6_addr *saddr,
 586		   u64 nonce)
 587{
 588	struct sk_buff *skb;
 589	struct in6_addr addr_buf;
 590	int inc_opt = dev->addr_len;
 591	int optlen = 0;
 592	struct nd_msg *msg;
 
 593
 594	if (!saddr) {
 595		if (ipv6_get_lladdr(dev, &addr_buf,
 596				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 597			return;
 598		saddr = &addr_buf;
 599	}
 600
 601	if (ipv6_addr_any(saddr))
 602		inc_opt = false;
 603	if (inc_opt)
 604		optlen += ndisc_opt_addr_space(dev,
 605					       NDISC_NEIGHBOUR_SOLICITATION);
 606	if (nonce != 0)
 607		optlen += 8;
 608
 609	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 610	if (!skb)
 611		return;
 612
 613	msg = skb_put(skb, sizeof(*msg));
 614	*msg = (struct nd_msg) {
 615		.icmph = {
 616			.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 617		},
 618		.target = *solicit,
 619	};
 620
 621	if (inc_opt)
 622		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 623				       dev->dev_addr,
 624				       NDISC_NEIGHBOUR_SOLICITATION);
 625	if (nonce != 0) {
 626		u8 *opt = skb_put(skb, 8);
 627
 628		opt[0] = ND_OPT_NONCE;
 629		opt[1] = 8 >> 3;
 630		memcpy(opt + 2, &nonce, 6);
 631	}
 632
 633	ndisc_send_skb(skb, daddr, saddr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 634}
 635
 636void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 637		   const struct in6_addr *daddr)
 638{
 639	struct sk_buff *skb;
 640	struct rs_msg *msg;
 641	int send_sllao = dev->addr_len;
 642	int optlen = 0;
 643
 644#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 645	/*
 646	 * According to section 2.2 of RFC 4429, we must not
 647	 * send router solicitations with a sllao from
 648	 * optimistic addresses, but we may send the solicitation
 649	 * if we don't include the sllao.  So here we check
 650	 * if our address is optimistic, and if so, we
 651	 * suppress the inclusion of the sllao.
 652	 */
 653	if (send_sllao) {
 654		struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 655							   dev, 1);
 656		if (ifp) {
 657			if (ifp->flags & IFA_F_OPTIMISTIC)  {
 658				send_sllao = 0;
 659			}
 660			in6_ifa_put(ifp);
 661		} else {
 662			send_sllao = 0;
 663		}
 664	}
 665#endif
 666	if (send_sllao)
 667		optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
 668
 669	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 670	if (!skb)
 671		return;
 672
 673	msg = skb_put(skb, sizeof(*msg));
 674	*msg = (struct rs_msg) {
 675		.icmph = {
 676			.icmp6_type = NDISC_ROUTER_SOLICITATION,
 677		},
 678	};
 679
 680	if (send_sllao)
 681		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 682				       dev->dev_addr,
 683				       NDISC_ROUTER_SOLICITATION);
 684
 685	ndisc_send_skb(skb, daddr, saddr);
 686}
 687
 688
 689static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 690{
 691	/*
 692	 *	"The sender MUST return an ICMP
 693	 *	 destination unreachable"
 694	 */
 695	dst_link_failure(skb);
 696	kfree_skb(skb);
 697}
 698
 699/* Called with locked neigh: either read or both */
 700
 701static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 702{
 703	struct in6_addr *saddr = NULL;
 704	struct in6_addr mcaddr;
 705	struct net_device *dev = neigh->dev;
 706	struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 707	int probes = atomic_read(&neigh->probes);
 708
 709	if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
 710					   dev, false, 1,
 711					   IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
 712		saddr = &ipv6_hdr(skb)->saddr;
 713	probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
 714	if (probes < 0) {
 715		if (!(neigh->nud_state & NUD_VALID)) {
 716			ND_PRINTK(1, dbg,
 717				  "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
 718				  __func__, target);
 719		}
 720		ndisc_send_ns(dev, target, target, saddr, 0);
 721	} else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
 722		neigh_app_ns(neigh);
 723	} else {
 724		addrconf_addr_solict_mult(target, &mcaddr);
 725		ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
 726	}
 727}
 728
 729static int pndisc_is_router(const void *pkey,
 730			    struct net_device *dev)
 731{
 732	struct pneigh_entry *n;
 733	int ret = -1;
 734
 735	read_lock_bh(&nd_tbl.lock);
 736	n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 737	if (n)
 738		ret = !!(n->flags & NTF_ROUTER);
 739	read_unlock_bh(&nd_tbl.lock);
 740
 741	return ret;
 742}
 743
 744void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 745		  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 746		  struct ndisc_options *ndopts)
 747{
 748	neigh_update(neigh, lladdr, new, flags, 0);
 749	/* report ndisc ops about neighbour update */
 750	ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
 751}
 752
 753static void ndisc_recv_ns(struct sk_buff *skb)
 754{
 755	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 756	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 757	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 758	u8 *lladdr = NULL;
 759	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 760				    offsetof(struct nd_msg, opt));
 761	struct ndisc_options ndopts;
 762	struct net_device *dev = skb->dev;
 763	struct inet6_ifaddr *ifp;
 764	struct inet6_dev *idev = NULL;
 765	struct neighbour *neigh;
 766	int dad = ipv6_addr_any(saddr);
 767	bool inc;
 768	int is_router = -1;
 769	u64 nonce = 0;
 770
 771	if (skb->len < sizeof(struct nd_msg)) {
 772		ND_PRINTK(2, warn, "NS: packet too short\n");
 773		return;
 774	}
 775
 776	if (ipv6_addr_is_multicast(&msg->target)) {
 777		ND_PRINTK(2, warn, "NS: multicast target address\n");
 778		return;
 779	}
 780
 781	/*
 782	 * RFC2461 7.1.1:
 783	 * DAD has to be destined for solicited node multicast address.
 784	 */
 785	if (dad && !ipv6_addr_is_solict_mult(daddr)) {
 786		ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
 787		return;
 788	}
 789
 790	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 791		ND_PRINTK(2, warn, "NS: invalid ND options\n");
 792		return;
 793	}
 794
 795	if (ndopts.nd_opts_src_lladdr) {
 796		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 797		if (!lladdr) {
 798			ND_PRINTK(2, warn,
 799				  "NS: invalid link-layer address length\n");
 800			return;
 801		}
 802
 803		/* RFC2461 7.1.1:
 804		 *	If the IP source address is the unspecified address,
 805		 *	there MUST NOT be source link-layer address option
 806		 *	in the message.
 807		 */
 808		if (dad) {
 809			ND_PRINTK(2, warn,
 810				  "NS: bad DAD packet (link-layer address option)\n");
 811			return;
 812		}
 813	}
 814	if (ndopts.nd_opts_nonce)
 815		memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
 816
 817	inc = ipv6_addr_is_multicast(daddr);
 818
 819	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 820	if (ifp) {
 821have_ifp:
 822		if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 823			if (dad) {
 824				if (nonce != 0 && ifp->dad_nonce == nonce) {
 825					u8 *np = (u8 *)&nonce;
 826					/* Matching nonce if looped back */
 827					ND_PRINTK(2, notice,
 828						  "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
 829						  ifp->idev->dev->name,
 830						  &ifp->addr, np);
 831					goto out;
 832				}
 833				/*
 834				 * We are colliding with another node
 835				 * who is doing DAD
 836				 * so fail our DAD process
 837				 */
 838				addrconf_dad_failure(skb, ifp);
 839				return;
 840			} else {
 841				/*
 842				 * This is not a dad solicitation.
 843				 * If we are an optimistic node,
 844				 * we should respond.
 845				 * Otherwise, we should ignore it.
 846				 */
 847				if (!(ifp->flags & IFA_F_OPTIMISTIC))
 848					goto out;
 849			}
 850		}
 851
 852		idev = ifp->idev;
 853	} else {
 854		struct net *net = dev_net(dev);
 855
 856		/* perhaps an address on the master device */
 857		if (netif_is_l3_slave(dev)) {
 858			struct net_device *mdev;
 859
 860			mdev = netdev_master_upper_dev_get_rcu(dev);
 861			if (mdev) {
 862				ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
 863				if (ifp)
 864					goto have_ifp;
 865			}
 866		}
 867
 868		idev = in6_dev_get(dev);
 869		if (!idev) {
 870			/* XXX: count this drop? */
 871			return;
 872		}
 873
 874		if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 875		    (idev->cnf.forwarding &&
 876		     (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 877		     (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 878			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 879			    skb->pkt_type != PACKET_HOST &&
 880			    inc &&
 881			    NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
 882				/*
 883				 * for anycast or proxy,
 884				 * sender should delay its response
 885				 * by a random time between 0 and
 886				 * MAX_ANYCAST_DELAY_TIME seconds.
 887				 * (RFC2461) -- yoshfuji
 888				 */
 889				struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 890				if (n)
 891					pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 892				goto out;
 893			}
 894		} else
 895			goto out;
 896	}
 897
 898	if (is_router < 0)
 899		is_router = idev->cnf.forwarding;
 900
 901	if (dad) {
 902		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
 903			      !!is_router, false, (ifp != NULL), true);
 904		goto out;
 905	}
 906
 907	if (inc)
 908		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 909	else
 910		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 911
 912	/*
 913	 *	update / create cache entry
 914	 *	for the source address
 915	 */
 916	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 917			       !inc || lladdr || !dev->addr_len);
 918	if (neigh)
 919		ndisc_update(dev, neigh, lladdr, NUD_STALE,
 920			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 921			     NEIGH_UPDATE_F_OVERRIDE,
 922			     NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
 923	if (neigh || !dev->header_ops) {
 924		ndisc_send_na(dev, saddr, &msg->target, !!is_router,
 925			      true, (ifp != NULL && inc), inc);
 926		if (neigh)
 927			neigh_release(neigh);
 928	}
 929
 930out:
 931	if (ifp)
 932		in6_ifa_put(ifp);
 933	else
 934		in6_dev_put(idev);
 935}
 936
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 937static void ndisc_recv_na(struct sk_buff *skb)
 938{
 939	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 940	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 941	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 942	u8 *lladdr = NULL;
 943	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 944				    offsetof(struct nd_msg, opt));
 945	struct ndisc_options ndopts;
 946	struct net_device *dev = skb->dev;
 947	struct inet6_dev *idev = __in6_dev_get(dev);
 948	struct inet6_ifaddr *ifp;
 949	struct neighbour *neigh;
 
 950
 951	if (skb->len < sizeof(struct nd_msg)) {
 952		ND_PRINTK(2, warn, "NA: packet too short\n");
 953		return;
 954	}
 955
 956	if (ipv6_addr_is_multicast(&msg->target)) {
 957		ND_PRINTK(2, warn, "NA: target address is multicast\n");
 958		return;
 959	}
 960
 961	if (ipv6_addr_is_multicast(daddr) &&
 962	    msg->icmph.icmp6_solicited) {
 963		ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
 964		return;
 965	}
 966
 967	/* For some 802.11 wireless deployments (and possibly other networks),
 968	 * there will be a NA proxy and unsolicitd packets are attacks
 969	 * and thus should not be accepted.
 
 970	 */
 971	if (!msg->icmph.icmp6_solicited && idev &&
 972	    idev->cnf.drop_unsolicited_na)
 973		return;
 974
 975	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 976		ND_PRINTK(2, warn, "NS: invalid ND option\n");
 977		return;
 978	}
 979	if (ndopts.nd_opts_tgt_lladdr) {
 980		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 981		if (!lladdr) {
 982			ND_PRINTK(2, warn,
 983				  "NA: invalid link-layer address length\n");
 984			return;
 985		}
 986	}
 987	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 988	if (ifp) {
 989		if (skb->pkt_type != PACKET_LOOPBACK
 990		    && (ifp->flags & IFA_F_TENTATIVE)) {
 991				addrconf_dad_failure(skb, ifp);
 992				return;
 993		}
 994		/* What should we make now? The advertisement
 995		   is invalid, but ndisc specs say nothing
 996		   about it. It could be misconfiguration, or
 997		   an smart proxy agent tries to help us :-)
 998
 999		   We should not print the error if NA has been
1000		   received from loopback - it is just our own
1001		   unsolicited advertisement.
1002		 */
1003		if (skb->pkt_type != PACKET_LOOPBACK)
1004			ND_PRINTK(1, warn,
1005				  "NA: %pM advertised our address %pI6c on %s!\n",
1006				  eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1007		in6_ifa_put(ifp);
1008		return;
1009	}
 
1010	neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1011
1012	if (neigh) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1013		u8 old_flags = neigh->flags;
1014		struct net *net = dev_net(dev);
1015
1016		if (neigh->nud_state & NUD_FAILED)
1017			goto out;
1018
1019		/*
1020		 * Don't update the neighbor cache entry on a proxy NA from
1021		 * ourselves because either the proxied node is off link or it
1022		 * has already sent a NA to us.
1023		 */
1024		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1025		    net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1026		    pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1027			/* XXX: idev->cnf.proxy_ndp */
1028			goto out;
1029		}
1030
1031		ndisc_update(dev, neigh, lladdr,
1032			     msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1033			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1034			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1035			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1036			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1037			     NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1038
1039		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1040			/*
1041			 * Change: router to host
1042			 */
1043			rt6_clean_tohost(dev_net(dev),  saddr);
1044		}
1045
1046out:
1047		neigh_release(neigh);
1048	}
1049}
1050
1051static void ndisc_recv_rs(struct sk_buff *skb)
1052{
1053	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1054	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1055	struct neighbour *neigh;
1056	struct inet6_dev *idev;
1057	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1058	struct ndisc_options ndopts;
1059	u8 *lladdr = NULL;
1060
1061	if (skb->len < sizeof(*rs_msg))
1062		return;
1063
1064	idev = __in6_dev_get(skb->dev);
1065	if (!idev) {
1066		ND_PRINTK(1, err, "RS: can't find in6 device\n");
1067		return;
1068	}
1069
1070	/* Don't accept RS if we're not in router mode */
1071	if (!idev->cnf.forwarding)
1072		goto out;
1073
1074	/*
1075	 * Don't update NCE if src = ::;
1076	 * this implies that the source node has no ip address assigned yet.
1077	 */
1078	if (ipv6_addr_any(saddr))
1079		goto out;
1080
1081	/* Parse ND options */
1082	if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1083		ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1084		goto out;
1085	}
1086
1087	if (ndopts.nd_opts_src_lladdr) {
1088		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1089					     skb->dev);
1090		if (!lladdr)
1091			goto out;
1092	}
1093
1094	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1095	if (neigh) {
1096		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1097			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1098			     NEIGH_UPDATE_F_OVERRIDE|
1099			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1100			     NDISC_ROUTER_SOLICITATION, &ndopts);
1101		neigh_release(neigh);
1102	}
1103out:
1104	return;
1105}
1106
1107static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1108{
1109	struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1110	struct sk_buff *skb;
1111	struct nlmsghdr *nlh;
1112	struct nduseroptmsg *ndmsg;
1113	struct net *net = dev_net(ra->dev);
1114	int err;
1115	int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1116				    + (opt->nd_opt_len << 3));
1117	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1118
1119	skb = nlmsg_new(msg_size, GFP_ATOMIC);
1120	if (!skb) {
1121		err = -ENOBUFS;
1122		goto errout;
1123	}
1124
1125	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1126	if (!nlh) {
1127		goto nla_put_failure;
1128	}
1129
1130	ndmsg = nlmsg_data(nlh);
1131	ndmsg->nduseropt_family = AF_INET6;
1132	ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1133	ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1134	ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1135	ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1136
1137	memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1138
1139	if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1140		goto nla_put_failure;
1141	nlmsg_end(skb, nlh);
1142
1143	rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1144	return;
1145
1146nla_put_failure:
1147	nlmsg_free(skb);
1148	err = -EMSGSIZE;
1149errout:
1150	rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1151}
1152
1153static void ndisc_router_discovery(struct sk_buff *skb)
1154{
1155	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1156	struct neighbour *neigh = NULL;
1157	struct inet6_dev *in6_dev;
1158	struct rt6_info *rt = NULL;
 
 
1159	int lifetime;
1160	struct ndisc_options ndopts;
1161	int optlen;
1162	unsigned int pref = 0;
1163	__u32 old_if_flags;
1164	bool send_ifinfo_notify = false;
1165
1166	__u8 *opt = (__u8 *)(ra_msg + 1);
1167
1168	optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1169		sizeof(struct ra_msg);
1170
1171	ND_PRINTK(2, info,
1172		  "RA: %s, dev: %s\n",
1173		  __func__, skb->dev->name);
1174	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1175		ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1176		return;
1177	}
1178	if (optlen < 0) {
1179		ND_PRINTK(2, warn, "RA: packet too short\n");
1180		return;
1181	}
1182
1183#ifdef CONFIG_IPV6_NDISC_NODETYPE
1184	if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1185		ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1186		return;
1187	}
1188#endif
1189
1190	/*
1191	 *	set the RA_RECV flag in the interface
1192	 */
1193
1194	in6_dev = __in6_dev_get(skb->dev);
1195	if (!in6_dev) {
1196		ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1197			  skb->dev->name);
1198		return;
1199	}
1200
1201	if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1202		ND_PRINTK(2, warn, "RA: invalid ND options\n");
1203		return;
1204	}
1205
1206	if (!ipv6_accept_ra(in6_dev)) {
1207		ND_PRINTK(2, info,
1208			  "RA: %s, did not accept ra for dev: %s\n",
1209			  __func__, skb->dev->name);
1210		goto skip_linkparms;
1211	}
1212
1213#ifdef CONFIG_IPV6_NDISC_NODETYPE
1214	/* skip link-specific parameters from interior routers */
1215	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1216		ND_PRINTK(2, info,
1217			  "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1218			  __func__, skb->dev->name);
1219		goto skip_linkparms;
1220	}
1221#endif
1222
1223	if (in6_dev->if_flags & IF_RS_SENT) {
1224		/*
1225		 *	flag that an RA was received after an RS was sent
1226		 *	out on this interface.
1227		 */
1228		in6_dev->if_flags |= IF_RA_RCVD;
1229	}
1230
1231	/*
1232	 * Remember the managed/otherconf flags from most recently
1233	 * received RA message (RFC 2462) -- yoshfuji
1234	 */
1235	old_if_flags = in6_dev->if_flags;
1236	in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1237				IF_RA_OTHERCONF)) |
1238				(ra_msg->icmph.icmp6_addrconf_managed ?
1239					IF_RA_MANAGED : 0) |
1240				(ra_msg->icmph.icmp6_addrconf_other ?
1241					IF_RA_OTHERCONF : 0);
1242
1243	if (old_if_flags != in6_dev->if_flags)
1244		send_ifinfo_notify = true;
1245
1246	if (!in6_dev->cnf.accept_ra_defrtr) {
1247		ND_PRINTK(2, info,
1248			  "RA: %s, defrtr is false for dev: %s\n",
1249			  __func__, skb->dev->name);
1250		goto skip_defrtr;
1251	}
1252
1253	/* Do not accept RA with source-addr found on local machine unless
1254	 * accept_ra_from_local is set to true.
1255	 */
 
1256	if (!in6_dev->cnf.accept_ra_from_local &&
1257	    ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1258			  in6_dev->dev, 0)) {
1259		ND_PRINTK(2, info,
1260			  "RA from local address detected on dev: %s: default router ignored\n",
1261			  skb->dev->name);
1262		goto skip_defrtr;
1263	}
1264
1265	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1266
1267#ifdef CONFIG_IPV6_ROUTER_PREF
1268	pref = ra_msg->icmph.icmp6_router_pref;
1269	/* 10b is handled as if it were 00b (medium) */
1270	if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1271	    !in6_dev->cnf.accept_ra_rtr_pref)
1272		pref = ICMPV6_ROUTER_PREF_MEDIUM;
1273#endif
1274
1275	rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1276
1277	if (rt) {
1278		neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
 
 
1279		if (!neigh) {
1280			ND_PRINTK(0, err,
1281				  "RA: %s got default router without neighbour\n",
1282				  __func__);
1283			ip6_rt_put(rt);
1284			return;
1285		}
1286	}
1287	if (rt && lifetime == 0) {
1288		ip6_del_rt(rt);
 
 
 
1289		rt = NULL;
1290	}
1291
1292	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, for dev: %s\n",
1293		  rt, lifetime, skb->dev->name);
1294	if (!rt && lifetime) {
1295		ND_PRINTK(3, info, "RA: adding default router\n");
1296
1297		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
 
 
 
 
1298		if (!rt) {
1299			ND_PRINTK(0, err,
1300				  "RA: %s failed to add default route\n",
1301				  __func__);
1302			return;
1303		}
1304
1305		neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
 
 
1306		if (!neigh) {
1307			ND_PRINTK(0, err,
1308				  "RA: %s got default router without neighbour\n",
1309				  __func__);
1310			ip6_rt_put(rt);
1311			return;
1312		}
1313		neigh->flags |= NTF_ROUTER;
1314	} else if (rt) {
1315		rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 
 
 
 
1316	}
1317
1318	if (rt)
1319		rt6_set_expires(rt, jiffies + (HZ * lifetime));
1320	if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1321	    ra_msg->icmph.icmp6_hop_limit) {
1322		if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1323			in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1324			if (rt)
1325				dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1326					       ra_msg->icmph.icmp6_hop_limit);
1327		} else {
1328			ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1329		}
1330	}
1331
1332skip_defrtr:
1333
1334	/*
1335	 *	Update Reachable Time and Retrans Timer
1336	 */
1337
1338	if (in6_dev->nd_parms) {
1339		unsigned long rtime = ntohl(ra_msg->retrans_timer);
1340
1341		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1342			rtime = (rtime*HZ)/1000;
1343			if (rtime < HZ/10)
1344				rtime = HZ/10;
1345			NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1346			in6_dev->tstamp = jiffies;
1347			send_ifinfo_notify = true;
1348		}
1349
1350		rtime = ntohl(ra_msg->reachable_time);
1351		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1352			rtime = (rtime*HZ)/1000;
1353
1354			if (rtime < HZ/10)
1355				rtime = HZ/10;
1356
1357			if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1358				NEIGH_VAR_SET(in6_dev->nd_parms,
1359					      BASE_REACHABLE_TIME, rtime);
1360				NEIGH_VAR_SET(in6_dev->nd_parms,
1361					      GC_STALETIME, 3 * rtime);
1362				in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1363				in6_dev->tstamp = jiffies;
1364				send_ifinfo_notify = true;
1365			}
1366		}
1367	}
1368
1369	/*
1370	 *	Send a notify if RA changed managed/otherconf flags or timer settings
1371	 */
1372	if (send_ifinfo_notify)
1373		inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1374
1375skip_linkparms:
1376
1377	/*
1378	 *	Process options.
1379	 */
1380
1381	if (!neigh)
1382		neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1383				       skb->dev, 1);
1384	if (neigh) {
1385		u8 *lladdr = NULL;
1386		if (ndopts.nd_opts_src_lladdr) {
1387			lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1388						     skb->dev);
1389			if (!lladdr) {
1390				ND_PRINTK(2, warn,
1391					  "RA: invalid link-layer address length\n");
1392				goto out;
1393			}
1394		}
1395		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1396			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1397			     NEIGH_UPDATE_F_OVERRIDE|
1398			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1399			     NEIGH_UPDATE_F_ISROUTER,
1400			     NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1401	}
1402
1403	if (!ipv6_accept_ra(in6_dev)) {
1404		ND_PRINTK(2, info,
1405			  "RA: %s, accept_ra is false for dev: %s\n",
1406			  __func__, skb->dev->name);
1407		goto out;
1408	}
1409
1410#ifdef CONFIG_IPV6_ROUTE_INFO
1411	if (!in6_dev->cnf.accept_ra_from_local &&
1412	    ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1413			  in6_dev->dev, 0)) {
1414		ND_PRINTK(2, info,
1415			  "RA from local address detected on dev: %s: router info ignored.\n",
1416			  skb->dev->name);
1417		goto skip_routeinfo;
1418	}
1419
1420	if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1421		struct nd_opt_hdr *p;
1422		for (p = ndopts.nd_opts_ri;
1423		     p;
1424		     p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1425			struct route_info *ri = (struct route_info *)p;
1426#ifdef CONFIG_IPV6_NDISC_NODETYPE
1427			if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1428			    ri->prefix_len == 0)
1429				continue;
1430#endif
1431			if (ri->prefix_len == 0 &&
1432			    !in6_dev->cnf.accept_ra_defrtr)
1433				continue;
1434			if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1435				continue;
1436			if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1437				continue;
1438			rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1439				      &ipv6_hdr(skb)->saddr);
1440		}
1441	}
1442
1443skip_routeinfo:
1444#endif
1445
1446#ifdef CONFIG_IPV6_NDISC_NODETYPE
1447	/* skip link-specific ndopts from interior routers */
1448	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1449		ND_PRINTK(2, info,
1450			  "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1451			  __func__, skb->dev->name);
1452		goto out;
1453	}
1454#endif
1455
1456	if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1457		struct nd_opt_hdr *p;
1458		for (p = ndopts.nd_opts_pi;
1459		     p;
1460		     p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1461			addrconf_prefix_rcv(skb->dev, (u8 *)p,
1462					    (p->nd_opt_len) << 3,
1463					    ndopts.nd_opts_src_lladdr != NULL);
1464		}
1465	}
1466
1467	if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1468		__be32 n;
1469		u32 mtu;
1470
1471		memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1472		mtu = ntohl(n);
1473
 
 
 
 
 
1474		if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1475			ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1476		} else if (in6_dev->cnf.mtu6 != mtu) {
1477			in6_dev->cnf.mtu6 = mtu;
1478
1479			if (rt)
1480				dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1481
1482			rt6_mtu_change(skb->dev, mtu);
1483		}
1484	}
1485
1486	if (ndopts.nd_useropts) {
1487		struct nd_opt_hdr *p;
1488		for (p = ndopts.nd_useropts;
1489		     p;
1490		     p = ndisc_next_useropt(skb->dev, p,
1491					    ndopts.nd_useropts_end)) {
1492			ndisc_ra_useropt(skb, p);
1493		}
1494	}
1495
1496	if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1497		ND_PRINTK(2, warn, "RA: invalid RA options\n");
1498	}
1499out:
1500	ip6_rt_put(rt);
 
 
 
 
 
 
1501	if (neigh)
1502		neigh_release(neigh);
1503}
1504
1505static void ndisc_redirect_rcv(struct sk_buff *skb)
1506{
1507	u8 *hdr;
1508	struct ndisc_options ndopts;
1509	struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1510	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1511				    offsetof(struct rd_msg, opt));
1512
1513#ifdef CONFIG_IPV6_NDISC_NODETYPE
1514	switch (skb->ndisc_nodetype) {
1515	case NDISC_NODETYPE_HOST:
1516	case NDISC_NODETYPE_NODEFAULT:
1517		ND_PRINTK(2, warn,
1518			  "Redirect: from host or unauthorized router\n");
1519		return;
1520	}
1521#endif
1522
1523	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1524		ND_PRINTK(2, warn,
1525			  "Redirect: source address is not link-local\n");
1526		return;
1527	}
1528
1529	if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1530		return;
1531
1532	if (!ndopts.nd_opts_rh) {
1533		ip6_redirect_no_header(skb, dev_net(skb->dev),
1534					skb->dev->ifindex, 0);
1535		return;
1536	}
1537
1538	hdr = (u8 *)ndopts.nd_opts_rh;
1539	hdr += 8;
1540	if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1541		return;
1542
1543	icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1544}
1545
1546static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1547					   struct sk_buff *orig_skb,
1548					   int rd_len)
1549{
1550	u8 *opt = skb_put(skb, rd_len);
1551
1552	memset(opt, 0, 8);
1553	*(opt++) = ND_OPT_REDIRECT_HDR;
1554	*(opt++) = (rd_len >> 3);
1555	opt += 6;
1556
1557	skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1558		      rd_len - 8);
1559}
1560
1561void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1562{
1563	struct net_device *dev = skb->dev;
1564	struct net *net = dev_net(dev);
1565	struct sock *sk = net->ipv6.ndisc_sk;
1566	int optlen = 0;
1567	struct inet_peer *peer;
1568	struct sk_buff *buff;
1569	struct rd_msg *msg;
1570	struct in6_addr saddr_buf;
1571	struct rt6_info *rt;
1572	struct dst_entry *dst;
1573	struct flowi6 fl6;
1574	int rd_len;
1575	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1576	   ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1577	bool ret;
1578
 
 
 
 
 
 
1579	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1580		ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1581			  dev->name);
1582		return;
1583	}
1584
1585	if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1586	    ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1587		ND_PRINTK(2, warn,
1588			  "Redirect: target address is not link-local unicast\n");
1589		return;
1590	}
1591
1592	icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1593			 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1594
1595	dst = ip6_route_output(net, NULL, &fl6);
1596	if (dst->error) {
1597		dst_release(dst);
1598		return;
1599	}
1600	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1601	if (IS_ERR(dst))
1602		return;
1603
1604	rt = (struct rt6_info *) dst;
1605
1606	if (rt->rt6i_flags & RTF_GATEWAY) {
1607		ND_PRINTK(2, warn,
1608			  "Redirect: destination is not a neighbour\n");
1609		goto release;
1610	}
1611	peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1612	ret = inet_peer_xrlim_allow(peer, 1*HZ);
1613	if (peer)
1614		inet_putpeer(peer);
1615	if (!ret)
1616		goto release;
1617
1618	if (dev->addr_len) {
1619		struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1620		if (!neigh) {
1621			ND_PRINTK(2, warn,
1622				  "Redirect: no neigh for target address\n");
1623			goto release;
1624		}
1625
1626		read_lock_bh(&neigh->lock);
1627		if (neigh->nud_state & NUD_VALID) {
1628			memcpy(ha_buf, neigh->ha, dev->addr_len);
1629			read_unlock_bh(&neigh->lock);
1630			ha = ha_buf;
1631			optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1632								ops_data_buf,
1633								&ops_data);
1634		} else
1635			read_unlock_bh(&neigh->lock);
1636
1637		neigh_release(neigh);
1638	}
1639
1640	rd_len = min_t(unsigned int,
1641		       IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1642		       skb->len + 8);
1643	rd_len &= ~0x7;
1644	optlen += rd_len;
1645
1646	buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1647	if (!buff)
1648		goto release;
1649
1650	msg = skb_put(buff, sizeof(*msg));
1651	*msg = (struct rd_msg) {
1652		.icmph = {
1653			.icmp6_type = NDISC_REDIRECT,
1654		},
1655		.target = *target,
1656		.dest = ipv6_hdr(skb)->daddr,
1657	};
1658
1659	/*
1660	 *	include target_address option
1661	 */
1662
1663	if (ha)
1664		ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1665
1666	/*
1667	 *	build redirect option and copy skb over to the new packet.
1668	 */
1669
1670	if (rd_len)
1671		ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1672
1673	skb_dst_set(buff, dst);
1674	ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1675	return;
1676
1677release:
1678	dst_release(dst);
1679}
1680
1681static void pndisc_redo(struct sk_buff *skb)
1682{
1683	ndisc_recv_ns(skb);
1684	kfree_skb(skb);
1685}
1686
 
 
 
 
 
1687static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1688{
1689	struct inet6_dev *idev = __in6_dev_get(skb->dev);
1690
1691	if (!idev)
1692		return true;
1693	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1694	    idev->cnf.suppress_frag_ndisc) {
1695		net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1696		return true;
1697	}
1698	return false;
1699}
1700
1701int ndisc_rcv(struct sk_buff *skb)
1702{
1703	struct nd_msg *msg;
1704
1705	if (ndisc_suppress_frag_ndisc(skb))
1706		return 0;
1707
1708	if (skb_linearize(skb))
1709		return 0;
1710
1711	msg = (struct nd_msg *)skb_transport_header(skb);
1712
1713	__skb_push(skb, skb->data - skb_transport_header(skb));
1714
1715	if (ipv6_hdr(skb)->hop_limit != 255) {
1716		ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1717			  ipv6_hdr(skb)->hop_limit);
1718		return 0;
1719	}
1720
1721	if (msg->icmph.icmp6_code != 0) {
1722		ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1723			  msg->icmph.icmp6_code);
1724		return 0;
1725	}
1726
1727	memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1728
1729	switch (msg->icmph.icmp6_type) {
1730	case NDISC_NEIGHBOUR_SOLICITATION:
 
1731		ndisc_recv_ns(skb);
1732		break;
1733
1734	case NDISC_NEIGHBOUR_ADVERTISEMENT:
1735		ndisc_recv_na(skb);
1736		break;
1737
1738	case NDISC_ROUTER_SOLICITATION:
1739		ndisc_recv_rs(skb);
1740		break;
1741
1742	case NDISC_ROUTER_ADVERTISEMENT:
1743		ndisc_router_discovery(skb);
1744		break;
1745
1746	case NDISC_REDIRECT:
1747		ndisc_redirect_rcv(skb);
1748		break;
1749	}
1750
1751	return 0;
1752}
1753
1754static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1755{
1756	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1757	struct netdev_notifier_change_info *change_info;
1758	struct net *net = dev_net(dev);
1759	struct inet6_dev *idev;
 
1760
1761	switch (event) {
1762	case NETDEV_CHANGEADDR:
1763		neigh_changeaddr(&nd_tbl, dev);
1764		fib6_run_gc(0, net, false);
1765		/* fallthrough */
1766	case NETDEV_UP:
1767		idev = in6_dev_get(dev);
1768		if (!idev)
1769			break;
1770		if (idev->cnf.ndisc_notify ||
1771		    net->ipv6.devconf_all->ndisc_notify)
1772			ndisc_send_unsol_na(dev);
1773		in6_dev_put(idev);
1774		break;
1775	case NETDEV_CHANGE:
 
 
 
 
 
 
 
 
 
1776		change_info = ptr;
1777		if (change_info->flags_changed & IFF_NOARP)
1778			neigh_changeaddr(&nd_tbl, dev);
 
 
1779		break;
1780	case NETDEV_DOWN:
1781		neigh_ifdown(&nd_tbl, dev);
1782		fib6_run_gc(0, net, false);
1783		break;
1784	case NETDEV_NOTIFY_PEERS:
1785		ndisc_send_unsol_na(dev);
1786		break;
1787	default:
1788		break;
1789	}
1790
1791	return NOTIFY_DONE;
1792}
1793
1794static struct notifier_block ndisc_netdev_notifier = {
1795	.notifier_call = ndisc_netdev_event,
1796	.priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1797};
1798
1799#ifdef CONFIG_SYSCTL
1800static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1801					 const char *func, const char *dev_name)
1802{
1803	static char warncomm[TASK_COMM_LEN];
1804	static int warned;
1805	if (strcmp(warncomm, current->comm) && warned < 5) {
1806		strcpy(warncomm, current->comm);
1807		pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1808			warncomm, func,
1809			dev_name, ctl->procname,
1810			dev_name, ctl->procname);
1811		warned++;
1812	}
1813}
1814
1815int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
 
1816{
1817	struct net_device *dev = ctl->extra1;
1818	struct inet6_dev *idev;
1819	int ret;
1820
1821	if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1822	    (strcmp(ctl->procname, "base_reachable_time") == 0))
1823		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1824
1825	if (strcmp(ctl->procname, "retrans_time") == 0)
1826		ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1827
1828	else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1829		ret = neigh_proc_dointvec_jiffies(ctl, write,
1830						  buffer, lenp, ppos);
1831
1832	else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1833		 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1834		ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1835						     buffer, lenp, ppos);
1836	else
1837		ret = -1;
1838
1839	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1840		if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1841			idev->nd_parms->reachable_time =
1842					neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1843		idev->tstamp = jiffies;
1844		inet6_ifinfo_notify(RTM_NEWLINK, idev);
1845		in6_dev_put(idev);
1846	}
1847	return ret;
1848}
1849
1850
1851#endif
1852
1853static int __net_init ndisc_net_init(struct net *net)
1854{
1855	struct ipv6_pinfo *np;
1856	struct sock *sk;
1857	int err;
1858
1859	err = inet_ctl_sock_create(&sk, PF_INET6,
1860				   SOCK_RAW, IPPROTO_ICMPV6, net);
1861	if (err < 0) {
1862		ND_PRINTK(0, err,
1863			  "NDISC: Failed to initialize the control socket (err %d)\n",
1864			  err);
1865		return err;
1866	}
1867
1868	net->ipv6.ndisc_sk = sk;
1869
1870	np = inet6_sk(sk);
1871	np->hop_limit = 255;
1872	/* Do not loopback ndisc messages */
1873	np->mc_loop = 0;
1874
1875	return 0;
1876}
1877
1878static void __net_exit ndisc_net_exit(struct net *net)
1879{
1880	inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1881}
1882
1883static struct pernet_operations ndisc_net_ops = {
1884	.init = ndisc_net_init,
1885	.exit = ndisc_net_exit,
1886};
1887
1888int __init ndisc_init(void)
1889{
1890	int err;
1891
1892	err = register_pernet_subsys(&ndisc_net_ops);
1893	if (err)
1894		return err;
1895	/*
1896	 * Initialize the neighbour table
1897	 */
1898	neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1899
1900#ifdef CONFIG_SYSCTL
1901	err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1902				    ndisc_ifinfo_sysctl_change);
1903	if (err)
1904		goto out_unregister_pernet;
1905out:
1906#endif
1907	return err;
1908
1909#ifdef CONFIG_SYSCTL
1910out_unregister_pernet:
1911	unregister_pernet_subsys(&ndisc_net_ops);
1912	goto out;
1913#endif
1914}
1915
1916int __init ndisc_late_init(void)
1917{
1918	return register_netdevice_notifier(&ndisc_netdev_notifier);
1919}
1920
1921void ndisc_late_cleanup(void)
1922{
1923	unregister_netdevice_notifier(&ndisc_netdev_notifier);
1924}
1925
1926void ndisc_cleanup(void)
1927{
1928#ifdef CONFIG_SYSCTL
1929	neigh_sysctl_unregister(&nd_tbl.parms);
1930#endif
1931	neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1932	unregister_pernet_subsys(&ndisc_net_ops);
1933}
v6.2
   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);
  84static int ndisc_is_multicast(const void *pkey);
  85
  86static const struct neigh_ops ndisc_generic_ops = {
  87	.family =		AF_INET6,
  88	.solicit =		ndisc_solicit,
  89	.error_report =		ndisc_error_report,
  90	.output =		neigh_resolve_output,
  91	.connected_output =	neigh_connected_output,
  92};
  93
  94static const struct neigh_ops ndisc_hh_ops = {
  95	.family =		AF_INET6,
  96	.solicit =		ndisc_solicit,
  97	.error_report =		ndisc_error_report,
  98	.output =		neigh_resolve_output,
  99	.connected_output =	neigh_resolve_output,
 100};
 101
 102
 103static const struct neigh_ops ndisc_direct_ops = {
 104	.family =		AF_INET6,
 105	.output =		neigh_direct_output,
 106	.connected_output =	neigh_direct_output,
 107};
 108
 109struct neigh_table nd_tbl = {
 110	.family =	AF_INET6,
 111	.key_len =	sizeof(struct in6_addr),
 112	.protocol =	cpu_to_be16(ETH_P_IPV6),
 113	.hash =		ndisc_hash,
 114	.key_eq =	ndisc_key_eq,
 115	.constructor =	ndisc_constructor,
 116	.pconstructor =	pndisc_constructor,
 117	.pdestructor =	pndisc_destructor,
 118	.proxy_redo =	pndisc_redo,
 119	.is_multicast =	ndisc_is_multicast,
 120	.allow_add  =   ndisc_allow_add,
 121	.id =		"ndisc_cache",
 122	.parms = {
 123		.tbl			= &nd_tbl,
 124		.reachable_time		= ND_REACHABLE_TIME,
 125		.data = {
 126			[NEIGH_VAR_MCAST_PROBES] = 3,
 127			[NEIGH_VAR_UCAST_PROBES] = 3,
 128			[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
 129			[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
 130			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
 131			[NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ,
 132			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 133			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 134			[NEIGH_VAR_PROXY_QLEN] = 64,
 135			[NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
 136			[NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
 137		},
 138	},
 139	.gc_interval =	  30 * HZ,
 140	.gc_thresh1 =	 128,
 141	.gc_thresh2 =	 512,
 142	.gc_thresh3 =	1024,
 143};
 144EXPORT_SYMBOL_GPL(nd_tbl);
 145
 146void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data,
 147			      int data_len, int pad)
 148{
 149	int space = __ndisc_opt_addr_space(data_len, pad);
 150	u8 *opt = skb_put(skb, space);
 151
 152	opt[0] = type;
 153	opt[1] = space>>3;
 154
 155	memset(opt + 2, 0, pad);
 156	opt   += pad;
 157	space -= pad;
 158
 159	memcpy(opt+2, data, data_len);
 160	data_len += 2;
 161	opt += data_len;
 162	space -= data_len;
 163	if (space > 0)
 164		memset(opt, 0, space);
 165}
 166EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
 167
 168static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
 169					  const void *data, u8 icmp6_type)
 170{
 171	__ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
 172				 ndisc_addr_option_pad(skb->dev->type));
 173	ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
 174}
 175
 176static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
 177						   void *ha,
 178						   const u8 *ops_data)
 179{
 180	ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
 181	ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
 182}
 183
 184static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 185					    struct nd_opt_hdr *end)
 186{
 187	int type;
 188	if (!cur || !end || cur >= end)
 189		return NULL;
 190	type = cur->nd_opt_type;
 191	do {
 192		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 193	} while (cur < end && cur->nd_opt_type != type);
 194	return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 195}
 196
 197static inline int ndisc_is_useropt(const struct net_device *dev,
 198				   struct nd_opt_hdr *opt)
 199{
 200	return opt->nd_opt_type == ND_OPT_RDNSS ||
 201		opt->nd_opt_type == ND_OPT_DNSSL ||
 202		opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
 203		opt->nd_opt_type == ND_OPT_PREF64 ||
 204		ndisc_ops_is_useropt(dev, opt->nd_opt_type);
 205}
 206
 207static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
 208					     struct nd_opt_hdr *cur,
 209					     struct nd_opt_hdr *end)
 210{
 211	if (!cur || !end || cur >= end)
 212		return NULL;
 213	do {
 214		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 215	} while (cur < end && !ndisc_is_useropt(dev, cur));
 216	return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
 217}
 218
 219struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 220					  u8 *opt, int opt_len,
 221					  struct ndisc_options *ndopts)
 222{
 223	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 224
 225	if (!nd_opt || opt_len < 0 || !ndopts)
 226		return NULL;
 227	memset(ndopts, 0, sizeof(*ndopts));
 228	while (opt_len) {
 229		int l;
 230		if (opt_len < sizeof(struct nd_opt_hdr))
 231			return NULL;
 232		l = nd_opt->nd_opt_len << 3;
 233		if (opt_len < l || l == 0)
 234			return NULL;
 235		if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
 236			goto next_opt;
 237		switch (nd_opt->nd_opt_type) {
 238		case ND_OPT_SOURCE_LL_ADDR:
 239		case ND_OPT_TARGET_LL_ADDR:
 240		case ND_OPT_MTU:
 241		case ND_OPT_NONCE:
 242		case ND_OPT_REDIRECT_HDR:
 243			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 244				ND_PRINTK(2, warn,
 245					  "%s: duplicated ND6 option found: type=%d\n",
 246					  __func__, nd_opt->nd_opt_type);
 247			} else {
 248				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 249			}
 250			break;
 251		case ND_OPT_PREFIX_INFO:
 252			ndopts->nd_opts_pi_end = nd_opt;
 253			if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 254				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 255			break;
 256#ifdef CONFIG_IPV6_ROUTE_INFO
 257		case ND_OPT_ROUTE_INFO:
 258			ndopts->nd_opts_ri_end = nd_opt;
 259			if (!ndopts->nd_opts_ri)
 260				ndopts->nd_opts_ri = nd_opt;
 261			break;
 262#endif
 263		default:
 264			if (ndisc_is_useropt(dev, nd_opt)) {
 265				ndopts->nd_useropts_end = nd_opt;
 266				if (!ndopts->nd_useropts)
 267					ndopts->nd_useropts = nd_opt;
 268			} else {
 269				/*
 270				 * Unknown options must be silently ignored,
 271				 * to accommodate future extension to the
 272				 * protocol.
 273				 */
 274				ND_PRINTK(2, notice,
 275					  "%s: ignored unsupported option; type=%d, len=%d\n",
 276					  __func__,
 277					  nd_opt->nd_opt_type,
 278					  nd_opt->nd_opt_len);
 279			}
 280		}
 281next_opt:
 282		opt_len -= l;
 283		nd_opt = ((void *)nd_opt) + l;
 284	}
 285	return ndopts;
 286}
 287
 288int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 289{
 290	switch (dev->type) {
 291	case ARPHRD_ETHER:
 292	case ARPHRD_IEEE802:	/* Not sure. Check it later. --ANK */
 293	case ARPHRD_FDDI:
 294		ipv6_eth_mc_map(addr, buf);
 295		return 0;
 296	case ARPHRD_ARCNET:
 297		ipv6_arcnet_mc_map(addr, buf);
 298		return 0;
 299	case ARPHRD_INFINIBAND:
 300		ipv6_ib_mc_map(addr, dev->broadcast, buf);
 301		return 0;
 302	case ARPHRD_IPGRE:
 303		return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 304	default:
 305		if (dir) {
 306			memcpy(buf, dev->broadcast, dev->addr_len);
 307			return 0;
 308		}
 309	}
 310	return -EINVAL;
 311}
 312EXPORT_SYMBOL(ndisc_mc_map);
 313
 314static u32 ndisc_hash(const void *pkey,
 315		      const struct net_device *dev,
 316		      __u32 *hash_rnd)
 317{
 318	return ndisc_hashfn(pkey, dev, hash_rnd);
 319}
 320
 321static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
 322{
 323	return neigh_key_eq128(n, pkey);
 324}
 325
 326static int ndisc_constructor(struct neighbour *neigh)
 327{
 328	struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
 329	struct net_device *dev = neigh->dev;
 330	struct inet6_dev *in6_dev;
 331	struct neigh_parms *parms;
 332	bool is_multicast = ipv6_addr_is_multicast(addr);
 333
 334	in6_dev = in6_dev_get(dev);
 335	if (!in6_dev) {
 336		return -EINVAL;
 337	}
 338
 339	parms = in6_dev->nd_parms;
 340	__neigh_parms_put(neigh->parms);
 341	neigh->parms = neigh_parms_clone(parms);
 342
 343	neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 344	if (!dev->header_ops) {
 345		neigh->nud_state = NUD_NOARP;
 346		neigh->ops = &ndisc_direct_ops;
 347		neigh->output = neigh_direct_output;
 348	} else {
 349		if (is_multicast) {
 350			neigh->nud_state = NUD_NOARP;
 351			ndisc_mc_map(addr, neigh->ha, dev, 1);
 352		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 353			neigh->nud_state = NUD_NOARP;
 354			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 355			if (dev->flags&IFF_LOOPBACK)
 356				neigh->type = RTN_LOCAL;
 357		} else if (dev->flags&IFF_POINTOPOINT) {
 358			neigh->nud_state = NUD_NOARP;
 359			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 360		}
 361		if (dev->header_ops->cache)
 362			neigh->ops = &ndisc_hh_ops;
 363		else
 364			neigh->ops = &ndisc_generic_ops;
 365		if (neigh->nud_state&NUD_VALID)
 366			neigh->output = neigh->ops->connected_output;
 367		else
 368			neigh->output = neigh->ops->output;
 369	}
 370	in6_dev_put(in6_dev);
 371	return 0;
 372}
 373
 374static int pndisc_constructor(struct pneigh_entry *n)
 375{
 376	struct in6_addr *addr = (struct in6_addr *)&n->key;
 377	struct in6_addr maddr;
 378	struct net_device *dev = n->dev;
 379
 380	if (!dev || !__in6_dev_get(dev))
 381		return -EINVAL;
 382	addrconf_addr_solict_mult(addr, &maddr);
 383	ipv6_dev_mc_inc(dev, &maddr);
 384	return 0;
 385}
 386
 387static void pndisc_destructor(struct pneigh_entry *n)
 388{
 389	struct in6_addr *addr = (struct in6_addr *)&n->key;
 390	struct in6_addr maddr;
 391	struct net_device *dev = n->dev;
 392
 393	if (!dev || !__in6_dev_get(dev))
 394		return;
 395	addrconf_addr_solict_mult(addr, &maddr);
 396	ipv6_dev_mc_dec(dev, &maddr);
 397}
 398
 399/* called with rtnl held */
 400static bool ndisc_allow_add(const struct net_device *dev,
 401			    struct netlink_ext_ack *extack)
 402{
 403	struct inet6_dev *idev = __in6_dev_get(dev);
 404
 405	if (!idev || idev->cnf.disable_ipv6) {
 406		NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
 407		return false;
 408	}
 409
 410	return true;
 411}
 412
 413static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 414				       int len)
 415{
 416	int hlen = LL_RESERVED_SPACE(dev);
 417	int tlen = dev->needed_tailroom;
 418	struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
 419	struct sk_buff *skb;
 420
 421	skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
 422	if (!skb) {
 423		ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
 424			  __func__);
 425		return NULL;
 426	}
 427
 428	skb->protocol = htons(ETH_P_IPV6);
 429	skb->dev = dev;
 430
 431	skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
 432	skb_reset_transport_header(skb);
 433
 434	/* Manually assign socket ownership as we avoid calling
 435	 * sock_alloc_send_pskb() to bypass wmem buffer limits
 436	 */
 437	skb_set_owner_w(skb, sk);
 438
 439	return skb;
 440}
 441
 442static void ip6_nd_hdr(struct sk_buff *skb,
 443		       const struct in6_addr *saddr,
 444		       const struct in6_addr *daddr,
 445		       int hop_limit, int len)
 446{
 447	struct ipv6hdr *hdr;
 448	struct inet6_dev *idev;
 449	unsigned tclass;
 450
 451	rcu_read_lock();
 452	idev = __in6_dev_get(skb->dev);
 453	tclass = idev ? idev->cnf.ndisc_tclass : 0;
 454	rcu_read_unlock();
 455
 456	skb_push(skb, sizeof(*hdr));
 457	skb_reset_network_header(skb);
 458	hdr = ipv6_hdr(skb);
 459
 460	ip6_flow_hdr(hdr, tclass, 0);
 461
 462	hdr->payload_len = htons(len);
 463	hdr->nexthdr = IPPROTO_ICMPV6;
 464	hdr->hop_limit = hop_limit;
 465
 466	hdr->saddr = *saddr;
 467	hdr->daddr = *daddr;
 468}
 469
 470void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
 471		    const struct in6_addr *saddr)
 
 472{
 473	struct dst_entry *dst = skb_dst(skb);
 474	struct net *net = dev_net(skb->dev);
 475	struct sock *sk = net->ipv6.ndisc_sk;
 476	struct inet6_dev *idev;
 477	int err;
 478	struct icmp6hdr *icmp6h = icmp6_hdr(skb);
 479	u8 type;
 480
 481	type = icmp6h->icmp6_type;
 482
 483	if (!dst) {
 484		struct flowi6 fl6;
 485		int oif = skb->dev->ifindex;
 486
 487		icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
 488		dst = icmp6_dst_alloc(skb->dev, &fl6);
 489		if (IS_ERR(dst)) {
 490			kfree_skb(skb);
 491			return;
 492		}
 493
 494		skb_dst_set(skb, dst);
 495	}
 496
 497	icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
 498					      IPPROTO_ICMPV6,
 499					      csum_partial(icmp6h,
 500							   skb->len, 0));
 501
 502	ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
 503
 504	rcu_read_lock();
 505	idev = __in6_dev_get(dst->dev);
 506	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 507
 508	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
 509		      net, sk, skb, NULL, dst->dev,
 510		      dst_output);
 511	if (!err) {
 512		ICMP6MSGOUT_INC_STATS(net, idev, type);
 513		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 514	}
 515
 516	rcu_read_unlock();
 517}
 518EXPORT_SYMBOL(ndisc_send_skb);
 519
 520void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 521		   const struct in6_addr *solicited_addr,
 522		   bool router, bool solicited, bool override, bool inc_opt)
 523{
 524	struct sk_buff *skb;
 525	struct in6_addr tmpaddr;
 526	struct inet6_ifaddr *ifp;
 527	const struct in6_addr *src_addr;
 528	struct nd_msg *msg;
 529	int optlen = 0;
 530
 531	/* for anycast or proxy, solicited_addr != src_addr */
 532	ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 533	if (ifp) {
 534		src_addr = solicited_addr;
 535		if (ifp->flags & IFA_F_OPTIMISTIC)
 536			override = false;
 537		inc_opt |= ifp->idev->cnf.force_tllao;
 538		in6_ifa_put(ifp);
 539	} else {
 540		if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 541				       inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 542				       &tmpaddr))
 543			return;
 544		src_addr = &tmpaddr;
 545	}
 546
 547	if (!dev->addr_len)
 548		inc_opt = false;
 549	if (inc_opt)
 550		optlen += ndisc_opt_addr_space(dev,
 551					       NDISC_NEIGHBOUR_ADVERTISEMENT);
 552
 553	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 554	if (!skb)
 555		return;
 556
 557	msg = skb_put(skb, sizeof(*msg));
 558	*msg = (struct nd_msg) {
 559		.icmph = {
 560			.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 561			.icmp6_router = router,
 562			.icmp6_solicited = solicited,
 563			.icmp6_override = override,
 564		},
 565		.target = *solicited_addr,
 566	};
 567
 568	if (inc_opt)
 569		ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 570				       dev->dev_addr,
 571				       NDISC_NEIGHBOUR_ADVERTISEMENT);
 572
 573	ndisc_send_skb(skb, daddr, src_addr);
 574}
 575
 576static void ndisc_send_unsol_na(struct net_device *dev)
 577{
 578	struct inet6_dev *idev;
 579	struct inet6_ifaddr *ifa;
 580
 581	idev = in6_dev_get(dev);
 582	if (!idev)
 583		return;
 584
 585	read_lock_bh(&idev->lock);
 586	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 587		/* skip tentative addresses until dad completes */
 588		if (ifa->flags & IFA_F_TENTATIVE &&
 589		    !(ifa->flags & IFA_F_OPTIMISTIC))
 590			continue;
 591
 592		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
 593			      /*router=*/ !!idev->cnf.forwarding,
 594			      /*solicited=*/ false, /*override=*/ true,
 595			      /*inc_opt=*/ true);
 596	}
 597	read_unlock_bh(&idev->lock);
 598
 599	in6_dev_put(idev);
 600}
 601
 602struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
 603				const struct in6_addr *saddr, u64 nonce)
 
 604{
 
 
 605	int inc_opt = dev->addr_len;
 606	struct sk_buff *skb;
 607	struct nd_msg *msg;
 608	int optlen = 0;
 609
 610	if (!saddr)
 611		return NULL;
 
 
 
 
 612
 613	if (ipv6_addr_any(saddr))
 614		inc_opt = false;
 615	if (inc_opt)
 616		optlen += ndisc_opt_addr_space(dev,
 617					       NDISC_NEIGHBOUR_SOLICITATION);
 618	if (nonce != 0)
 619		optlen += 8;
 620
 621	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 622	if (!skb)
 623		return NULL;
 624
 625	msg = skb_put(skb, sizeof(*msg));
 626	*msg = (struct nd_msg) {
 627		.icmph = {
 628			.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 629		},
 630		.target = *solicit,
 631	};
 632
 633	if (inc_opt)
 634		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 635				       dev->dev_addr,
 636				       NDISC_NEIGHBOUR_SOLICITATION);
 637	if (nonce != 0) {
 638		u8 *opt = skb_put(skb, 8);
 639
 640		opt[0] = ND_OPT_NONCE;
 641		opt[1] = 8 >> 3;
 642		memcpy(opt + 2, &nonce, 6);
 643	}
 644
 645	return skb;
 646}
 647EXPORT_SYMBOL(ndisc_ns_create);
 648
 649void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 650		   const struct in6_addr *daddr, const struct in6_addr *saddr,
 651		   u64 nonce)
 652{
 653	struct in6_addr addr_buf;
 654	struct sk_buff *skb;
 655
 656	if (!saddr) {
 657		if (ipv6_get_lladdr(dev, &addr_buf,
 658				    (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
 659			return;
 660		saddr = &addr_buf;
 661	}
 662
 663	skb = ndisc_ns_create(dev, solicit, saddr, nonce);
 664
 665	if (skb)
 666		ndisc_send_skb(skb, daddr, saddr);
 667}
 668
 669void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 670		   const struct in6_addr *daddr)
 671{
 672	struct sk_buff *skb;
 673	struct rs_msg *msg;
 674	int send_sllao = dev->addr_len;
 675	int optlen = 0;
 676
 677#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 678	/*
 679	 * According to section 2.2 of RFC 4429, we must not
 680	 * send router solicitations with a sllao from
 681	 * optimistic addresses, but we may send the solicitation
 682	 * if we don't include the sllao.  So here we check
 683	 * if our address is optimistic, and if so, we
 684	 * suppress the inclusion of the sllao.
 685	 */
 686	if (send_sllao) {
 687		struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 688							   dev, 1);
 689		if (ifp) {
 690			if (ifp->flags & IFA_F_OPTIMISTIC)  {
 691				send_sllao = 0;
 692			}
 693			in6_ifa_put(ifp);
 694		} else {
 695			send_sllao = 0;
 696		}
 697	}
 698#endif
 699	if (send_sllao)
 700		optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
 701
 702	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 703	if (!skb)
 704		return;
 705
 706	msg = skb_put(skb, sizeof(*msg));
 707	*msg = (struct rs_msg) {
 708		.icmph = {
 709			.icmp6_type = NDISC_ROUTER_SOLICITATION,
 710		},
 711	};
 712
 713	if (send_sllao)
 714		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 715				       dev->dev_addr,
 716				       NDISC_ROUTER_SOLICITATION);
 717
 718	ndisc_send_skb(skb, daddr, saddr);
 719}
 720
 721
 722static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 723{
 724	/*
 725	 *	"The sender MUST return an ICMP
 726	 *	 destination unreachable"
 727	 */
 728	dst_link_failure(skb);
 729	kfree_skb(skb);
 730}
 731
 732/* Called with locked neigh: either read or both */
 733
 734static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 735{
 736	struct in6_addr *saddr = NULL;
 737	struct in6_addr mcaddr;
 738	struct net_device *dev = neigh->dev;
 739	struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 740	int probes = atomic_read(&neigh->probes);
 741
 742	if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
 743					   dev, false, 1,
 744					   IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
 745		saddr = &ipv6_hdr(skb)->saddr;
 746	probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
 747	if (probes < 0) {
 748		if (!(neigh->nud_state & NUD_VALID)) {
 749			ND_PRINTK(1, dbg,
 750				  "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
 751				  __func__, target);
 752		}
 753		ndisc_send_ns(dev, target, target, saddr, 0);
 754	} else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
 755		neigh_app_ns(neigh);
 756	} else {
 757		addrconf_addr_solict_mult(target, &mcaddr);
 758		ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
 759	}
 760}
 761
 762static int pndisc_is_router(const void *pkey,
 763			    struct net_device *dev)
 764{
 765	struct pneigh_entry *n;
 766	int ret = -1;
 767
 768	read_lock_bh(&nd_tbl.lock);
 769	n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 770	if (n)
 771		ret = !!(n->flags & NTF_ROUTER);
 772	read_unlock_bh(&nd_tbl.lock);
 773
 774	return ret;
 775}
 776
 777void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 778		  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 779		  struct ndisc_options *ndopts)
 780{
 781	neigh_update(neigh, lladdr, new, flags, 0);
 782	/* report ndisc ops about neighbour update */
 783	ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
 784}
 785
 786static void ndisc_recv_ns(struct sk_buff *skb)
 787{
 788	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 789	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 790	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 791	u8 *lladdr = NULL;
 792	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 793				    offsetof(struct nd_msg, opt));
 794	struct ndisc_options ndopts;
 795	struct net_device *dev = skb->dev;
 796	struct inet6_ifaddr *ifp;
 797	struct inet6_dev *idev = NULL;
 798	struct neighbour *neigh;
 799	int dad = ipv6_addr_any(saddr);
 800	bool inc;
 801	int is_router = -1;
 802	u64 nonce = 0;
 803
 804	if (skb->len < sizeof(struct nd_msg)) {
 805		ND_PRINTK(2, warn, "NS: packet too short\n");
 806		return;
 807	}
 808
 809	if (ipv6_addr_is_multicast(&msg->target)) {
 810		ND_PRINTK(2, warn, "NS: multicast target address\n");
 811		return;
 812	}
 813
 814	/*
 815	 * RFC2461 7.1.1:
 816	 * DAD has to be destined for solicited node multicast address.
 817	 */
 818	if (dad && !ipv6_addr_is_solict_mult(daddr)) {
 819		ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
 820		return;
 821	}
 822
 823	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
 824		ND_PRINTK(2, warn, "NS: invalid ND options\n");
 825		return;
 826	}
 827
 828	if (ndopts.nd_opts_src_lladdr) {
 829		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 830		if (!lladdr) {
 831			ND_PRINTK(2, warn,
 832				  "NS: invalid link-layer address length\n");
 833			return;
 834		}
 835
 836		/* RFC2461 7.1.1:
 837		 *	If the IP source address is the unspecified address,
 838		 *	there MUST NOT be source link-layer address option
 839		 *	in the message.
 840		 */
 841		if (dad) {
 842			ND_PRINTK(2, warn,
 843				  "NS: bad DAD packet (link-layer address option)\n");
 844			return;
 845		}
 846	}
 847	if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
 848		memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
 849
 850	inc = ipv6_addr_is_multicast(daddr);
 851
 852	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 853	if (ifp) {
 854have_ifp:
 855		if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 856			if (dad) {
 857				if (nonce != 0 && ifp->dad_nonce == nonce) {
 858					u8 *np = (u8 *)&nonce;
 859					/* Matching nonce if looped back */
 860					ND_PRINTK(2, notice,
 861						  "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
 862						  ifp->idev->dev->name,
 863						  &ifp->addr, np);
 864					goto out;
 865				}
 866				/*
 867				 * We are colliding with another node
 868				 * who is doing DAD
 869				 * so fail our DAD process
 870				 */
 871				addrconf_dad_failure(skb, ifp);
 872				return;
 873			} else {
 874				/*
 875				 * This is not a dad solicitation.
 876				 * If we are an optimistic node,
 877				 * we should respond.
 878				 * Otherwise, we should ignore it.
 879				 */
 880				if (!(ifp->flags & IFA_F_OPTIMISTIC))
 881					goto out;
 882			}
 883		}
 884
 885		idev = ifp->idev;
 886	} else {
 887		struct net *net = dev_net(dev);
 888
 889		/* perhaps an address on the master device */
 890		if (netif_is_l3_slave(dev)) {
 891			struct net_device *mdev;
 892
 893			mdev = netdev_master_upper_dev_get_rcu(dev);
 894			if (mdev) {
 895				ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
 896				if (ifp)
 897					goto have_ifp;
 898			}
 899		}
 900
 901		idev = in6_dev_get(dev);
 902		if (!idev) {
 903			/* XXX: count this drop? */
 904			return;
 905		}
 906
 907		if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 908		    (idev->cnf.forwarding &&
 909		     (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 910		     (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 911			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 912			    skb->pkt_type != PACKET_HOST &&
 913			    inc &&
 914			    NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
 915				/*
 916				 * for anycast or proxy,
 917				 * sender should delay its response
 918				 * by a random time between 0 and
 919				 * MAX_ANYCAST_DELAY_TIME seconds.
 920				 * (RFC2461) -- yoshfuji
 921				 */
 922				struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 923				if (n)
 924					pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 925				goto out;
 926			}
 927		} else
 928			goto out;
 929	}
 930
 931	if (is_router < 0)
 932		is_router = idev->cnf.forwarding;
 933
 934	if (dad) {
 935		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
 936			      !!is_router, false, (ifp != NULL), true);
 937		goto out;
 938	}
 939
 940	if (inc)
 941		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 942	else
 943		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 944
 945	/*
 946	 *	update / create cache entry
 947	 *	for the source address
 948	 */
 949	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 950			       !inc || lladdr || !dev->addr_len);
 951	if (neigh)
 952		ndisc_update(dev, neigh, lladdr, NUD_STALE,
 953			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 954			     NEIGH_UPDATE_F_OVERRIDE,
 955			     NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
 956	if (neigh || !dev->header_ops) {
 957		ndisc_send_na(dev, saddr, &msg->target, !!is_router,
 958			      true, (ifp != NULL && inc), inc);
 959		if (neigh)
 960			neigh_release(neigh);
 961	}
 962
 963out:
 964	if (ifp)
 965		in6_ifa_put(ifp);
 966	else
 967		in6_dev_put(idev);
 968}
 969
 970static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
 971{
 972	struct inet6_dev *idev = __in6_dev_get(dev);
 973
 974	switch (idev->cnf.accept_untracked_na) {
 975	case 0: /* Don't accept untracked na (absent in neighbor cache) */
 976		return 0;
 977	case 1: /* Create new entries from na if currently untracked */
 978		return 1;
 979	case 2: /* Create new entries from untracked na only if saddr is in the
 980		 * same subnet as an address configured on the interface that
 981		 * received the na
 982		 */
 983		return !!ipv6_chk_prefix(saddr, dev);
 984	default:
 985		return 0;
 986	}
 987}
 988
 989static void ndisc_recv_na(struct sk_buff *skb)
 990{
 991	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 992	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 993	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 994	u8 *lladdr = NULL;
 995	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 996				    offsetof(struct nd_msg, opt));
 997	struct ndisc_options ndopts;
 998	struct net_device *dev = skb->dev;
 999	struct inet6_dev *idev = __in6_dev_get(dev);
1000	struct inet6_ifaddr *ifp;
1001	struct neighbour *neigh;
1002	u8 new_state;
1003
1004	if (skb->len < sizeof(struct nd_msg)) {
1005		ND_PRINTK(2, warn, "NA: packet too short\n");
1006		return;
1007	}
1008
1009	if (ipv6_addr_is_multicast(&msg->target)) {
1010		ND_PRINTK(2, warn, "NA: target address is multicast\n");
1011		return;
1012	}
1013
1014	if (ipv6_addr_is_multicast(daddr) &&
1015	    msg->icmph.icmp6_solicited) {
1016		ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
1017		return;
1018	}
1019
1020	/* For some 802.11 wireless deployments (and possibly other networks),
1021	 * there will be a NA proxy and unsolicitd packets are attacks
1022	 * and thus should not be accepted.
1023	 * drop_unsolicited_na takes precedence over accept_untracked_na
1024	 */
1025	if (!msg->icmph.icmp6_solicited && idev &&
1026	    idev->cnf.drop_unsolicited_na)
1027		return;
1028
1029	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
1030		ND_PRINTK(2, warn, "NS: invalid ND option\n");
1031		return;
1032	}
1033	if (ndopts.nd_opts_tgt_lladdr) {
1034		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1035		if (!lladdr) {
1036			ND_PRINTK(2, warn,
1037				  "NA: invalid link-layer address length\n");
1038			return;
1039		}
1040	}
1041	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1042	if (ifp) {
1043		if (skb->pkt_type != PACKET_LOOPBACK
1044		    && (ifp->flags & IFA_F_TENTATIVE)) {
1045				addrconf_dad_failure(skb, ifp);
1046				return;
1047		}
1048		/* What should we make now? The advertisement
1049		   is invalid, but ndisc specs say nothing
1050		   about it. It could be misconfiguration, or
1051		   an smart proxy agent tries to help us :-)
1052
1053		   We should not print the error if NA has been
1054		   received from loopback - it is just our own
1055		   unsolicited advertisement.
1056		 */
1057		if (skb->pkt_type != PACKET_LOOPBACK)
1058			ND_PRINTK(1, warn,
1059				  "NA: %pM advertised our address %pI6c on %s!\n",
1060				  eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1061		in6_ifa_put(ifp);
1062		return;
1063	}
1064
1065	neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1066
1067	/* RFC 9131 updates original Neighbour Discovery RFC 4861.
1068	 * NAs with Target LL Address option without a corresponding
1069	 * entry in the neighbour cache can now create a STALE neighbour
1070	 * cache entry on routers.
1071	 *
1072	 *   entry accept  fwding  solicited        behaviour
1073	 * ------- ------  ------  ---------    ----------------------
1074	 * present      X       X         0     Set state to STALE
1075	 * present      X       X         1     Set state to REACHABLE
1076	 *  absent      0       X         X     Do nothing
1077	 *  absent      1       0         X     Do nothing
1078	 *  absent      1       1         X     Add a new STALE entry
1079	 *
1080	 * Note that we don't do a (daddr == all-routers-mcast) check.
1081	 */
1082	new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1083	if (!neigh && lladdr && idev && idev->cnf.forwarding) {
1084		if (accept_untracked_na(dev, saddr)) {
1085			neigh = neigh_create(&nd_tbl, &msg->target, dev);
1086			new_state = NUD_STALE;
1087		}
1088	}
1089
1090	if (neigh && !IS_ERR(neigh)) {
1091		u8 old_flags = neigh->flags;
1092		struct net *net = dev_net(dev);
1093
1094		if (neigh->nud_state & NUD_FAILED)
1095			goto out;
1096
1097		/*
1098		 * Don't update the neighbor cache entry on a proxy NA from
1099		 * ourselves because either the proxied node is off link or it
1100		 * has already sent a NA to us.
1101		 */
1102		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1103		    net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1104		    pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1105			/* XXX: idev->cnf.proxy_ndp */
1106			goto out;
1107		}
1108
1109		ndisc_update(dev, neigh, lladdr,
1110			     new_state,
1111			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1112			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1113			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1114			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1115			     NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1116
1117		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1118			/*
1119			 * Change: router to host
1120			 */
1121			rt6_clean_tohost(dev_net(dev),  saddr);
1122		}
1123
1124out:
1125		neigh_release(neigh);
1126	}
1127}
1128
1129static void ndisc_recv_rs(struct sk_buff *skb)
1130{
1131	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1132	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1133	struct neighbour *neigh;
1134	struct inet6_dev *idev;
1135	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1136	struct ndisc_options ndopts;
1137	u8 *lladdr = NULL;
1138
1139	if (skb->len < sizeof(*rs_msg))
1140		return;
1141
1142	idev = __in6_dev_get(skb->dev);
1143	if (!idev) {
1144		ND_PRINTK(1, err, "RS: can't find in6 device\n");
1145		return;
1146	}
1147
1148	/* Don't accept RS if we're not in router mode */
1149	if (!idev->cnf.forwarding)
1150		goto out;
1151
1152	/*
1153	 * Don't update NCE if src = ::;
1154	 * this implies that the source node has no ip address assigned yet.
1155	 */
1156	if (ipv6_addr_any(saddr))
1157		goto out;
1158
1159	/* Parse ND options */
1160	if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1161		ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1162		goto out;
1163	}
1164
1165	if (ndopts.nd_opts_src_lladdr) {
1166		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1167					     skb->dev);
1168		if (!lladdr)
1169			goto out;
1170	}
1171
1172	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1173	if (neigh) {
1174		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1175			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1176			     NEIGH_UPDATE_F_OVERRIDE|
1177			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1178			     NDISC_ROUTER_SOLICITATION, &ndopts);
1179		neigh_release(neigh);
1180	}
1181out:
1182	return;
1183}
1184
1185static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1186{
1187	struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1188	struct sk_buff *skb;
1189	struct nlmsghdr *nlh;
1190	struct nduseroptmsg *ndmsg;
1191	struct net *net = dev_net(ra->dev);
1192	int err;
1193	int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1194				    + (opt->nd_opt_len << 3));
1195	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1196
1197	skb = nlmsg_new(msg_size, GFP_ATOMIC);
1198	if (!skb) {
1199		err = -ENOBUFS;
1200		goto errout;
1201	}
1202
1203	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1204	if (!nlh) {
1205		goto nla_put_failure;
1206	}
1207
1208	ndmsg = nlmsg_data(nlh);
1209	ndmsg->nduseropt_family = AF_INET6;
1210	ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1211	ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1212	ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1213	ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1214
1215	memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1216
1217	if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1218		goto nla_put_failure;
1219	nlmsg_end(skb, nlh);
1220
1221	rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1222	return;
1223
1224nla_put_failure:
1225	nlmsg_free(skb);
1226	err = -EMSGSIZE;
1227errout:
1228	rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1229}
1230
1231static void ndisc_router_discovery(struct sk_buff *skb)
1232{
1233	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1234	struct neighbour *neigh = NULL;
1235	struct inet6_dev *in6_dev;
1236	struct fib6_info *rt = NULL;
1237	u32 defrtr_usr_metric;
1238	struct net *net;
1239	int lifetime;
1240	struct ndisc_options ndopts;
1241	int optlen;
1242	unsigned int pref = 0;
1243	__u32 old_if_flags;
1244	bool send_ifinfo_notify = false;
1245
1246	__u8 *opt = (__u8 *)(ra_msg + 1);
1247
1248	optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1249		sizeof(struct ra_msg);
1250
1251	ND_PRINTK(2, info,
1252		  "RA: %s, dev: %s\n",
1253		  __func__, skb->dev->name);
1254	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1255		ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1256		return;
1257	}
1258	if (optlen < 0) {
1259		ND_PRINTK(2, warn, "RA: packet too short\n");
1260		return;
1261	}
1262
1263#ifdef CONFIG_IPV6_NDISC_NODETYPE
1264	if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1265		ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1266		return;
1267	}
1268#endif
1269
1270	/*
1271	 *	set the RA_RECV flag in the interface
1272	 */
1273
1274	in6_dev = __in6_dev_get(skb->dev);
1275	if (!in6_dev) {
1276		ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1277			  skb->dev->name);
1278		return;
1279	}
1280
1281	if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1282		ND_PRINTK(2, warn, "RA: invalid ND options\n");
1283		return;
1284	}
1285
1286	if (!ipv6_accept_ra(in6_dev)) {
1287		ND_PRINTK(2, info,
1288			  "RA: %s, did not accept ra for dev: %s\n",
1289			  __func__, skb->dev->name);
1290		goto skip_linkparms;
1291	}
1292
1293#ifdef CONFIG_IPV6_NDISC_NODETYPE
1294	/* skip link-specific parameters from interior routers */
1295	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1296		ND_PRINTK(2, info,
1297			  "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1298			  __func__, skb->dev->name);
1299		goto skip_linkparms;
1300	}
1301#endif
1302
1303	if (in6_dev->if_flags & IF_RS_SENT) {
1304		/*
1305		 *	flag that an RA was received after an RS was sent
1306		 *	out on this interface.
1307		 */
1308		in6_dev->if_flags |= IF_RA_RCVD;
1309	}
1310
1311	/*
1312	 * Remember the managed/otherconf flags from most recently
1313	 * received RA message (RFC 2462) -- yoshfuji
1314	 */
1315	old_if_flags = in6_dev->if_flags;
1316	in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1317				IF_RA_OTHERCONF)) |
1318				(ra_msg->icmph.icmp6_addrconf_managed ?
1319					IF_RA_MANAGED : 0) |
1320				(ra_msg->icmph.icmp6_addrconf_other ?
1321					IF_RA_OTHERCONF : 0);
1322
1323	if (old_if_flags != in6_dev->if_flags)
1324		send_ifinfo_notify = true;
1325
1326	if (!in6_dev->cnf.accept_ra_defrtr) {
1327		ND_PRINTK(2, info,
1328			  "RA: %s, defrtr is false for dev: %s\n",
1329			  __func__, skb->dev->name);
1330		goto skip_defrtr;
1331	}
1332
1333	/* Do not accept RA with source-addr found on local machine unless
1334	 * accept_ra_from_local is set to true.
1335	 */
1336	net = dev_net(in6_dev->dev);
1337	if (!in6_dev->cnf.accept_ra_from_local &&
1338	    ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
 
1339		ND_PRINTK(2, info,
1340			  "RA from local address detected on dev: %s: default router ignored\n",
1341			  skb->dev->name);
1342		goto skip_defrtr;
1343	}
1344
1345	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1346
1347#ifdef CONFIG_IPV6_ROUTER_PREF
1348	pref = ra_msg->icmph.icmp6_router_pref;
1349	/* 10b is handled as if it were 00b (medium) */
1350	if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1351	    !in6_dev->cnf.accept_ra_rtr_pref)
1352		pref = ICMPV6_ROUTER_PREF_MEDIUM;
1353#endif
1354	/* routes added from RAs do not use nexthop objects */
1355	rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
 
1356	if (rt) {
1357		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1358					 rt->fib6_nh->fib_nh_dev, NULL,
1359					  &ipv6_hdr(skb)->saddr);
1360		if (!neigh) {
1361			ND_PRINTK(0, err,
1362				  "RA: %s got default router without neighbour\n",
1363				  __func__);
1364			fib6_info_release(rt);
1365			return;
1366		}
1367	}
1368	/* Set default route metric as specified by user */
1369	defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1370	/* delete the route if lifetime is 0 or if metric needs change */
1371	if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1372		ip6_del_rt(net, rt, false);
1373		rt = NULL;
1374	}
1375
1376	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, metric: %d, for dev: %s\n",
1377		  rt, lifetime, defrtr_usr_metric, skb->dev->name);
1378	if (!rt && lifetime) {
1379		ND_PRINTK(3, info, "RA: adding default router\n");
1380
1381		if (neigh)
1382			neigh_release(neigh);
1383
1384		rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1385					 skb->dev, pref, defrtr_usr_metric);
1386		if (!rt) {
1387			ND_PRINTK(0, err,
1388				  "RA: %s failed to add default route\n",
1389				  __func__);
1390			return;
1391		}
1392
1393		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1394					 rt->fib6_nh->fib_nh_dev, NULL,
1395					  &ipv6_hdr(skb)->saddr);
1396		if (!neigh) {
1397			ND_PRINTK(0, err,
1398				  "RA: %s got default router without neighbour\n",
1399				  __func__);
1400			fib6_info_release(rt);
1401			return;
1402		}
1403		neigh->flags |= NTF_ROUTER;
1404	} else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1405		struct nl_info nlinfo = {
1406			.nl_net = net,
1407		};
1408		rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1409		inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
1410	}
1411
1412	if (rt)
1413		fib6_set_expires(rt, jiffies + (HZ * lifetime));
1414	if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1415	    ra_msg->icmph.icmp6_hop_limit) {
1416		if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1417			in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1418			fib6_metric_set(rt, RTAX_HOPLIMIT,
1419					ra_msg->icmph.icmp6_hop_limit);
 
1420		} else {
1421			ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1422		}
1423	}
1424
1425skip_defrtr:
1426
1427	/*
1428	 *	Update Reachable Time and Retrans Timer
1429	 */
1430
1431	if (in6_dev->nd_parms) {
1432		unsigned long rtime = ntohl(ra_msg->retrans_timer);
1433
1434		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1435			rtime = (rtime*HZ)/1000;
1436			if (rtime < HZ/100)
1437				rtime = HZ/100;
1438			NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1439			in6_dev->tstamp = jiffies;
1440			send_ifinfo_notify = true;
1441		}
1442
1443		rtime = ntohl(ra_msg->reachable_time);
1444		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1445			rtime = (rtime*HZ)/1000;
1446
1447			if (rtime < HZ/10)
1448				rtime = HZ/10;
1449
1450			if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1451				NEIGH_VAR_SET(in6_dev->nd_parms,
1452					      BASE_REACHABLE_TIME, rtime);
1453				NEIGH_VAR_SET(in6_dev->nd_parms,
1454					      GC_STALETIME, 3 * rtime);
1455				in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1456				in6_dev->tstamp = jiffies;
1457				send_ifinfo_notify = true;
1458			}
1459		}
1460	}
1461
 
 
 
 
 
 
1462skip_linkparms:
1463
1464	/*
1465	 *	Process options.
1466	 */
1467
1468	if (!neigh)
1469		neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1470				       skb->dev, 1);
1471	if (neigh) {
1472		u8 *lladdr = NULL;
1473		if (ndopts.nd_opts_src_lladdr) {
1474			lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1475						     skb->dev);
1476			if (!lladdr) {
1477				ND_PRINTK(2, warn,
1478					  "RA: invalid link-layer address length\n");
1479				goto out;
1480			}
1481		}
1482		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1483			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1484			     NEIGH_UPDATE_F_OVERRIDE|
1485			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1486			     NEIGH_UPDATE_F_ISROUTER,
1487			     NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1488	}
1489
1490	if (!ipv6_accept_ra(in6_dev)) {
1491		ND_PRINTK(2, info,
1492			  "RA: %s, accept_ra is false for dev: %s\n",
1493			  __func__, skb->dev->name);
1494		goto out;
1495	}
1496
1497#ifdef CONFIG_IPV6_ROUTE_INFO
1498	if (!in6_dev->cnf.accept_ra_from_local &&
1499	    ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1500			  in6_dev->dev, 0)) {
1501		ND_PRINTK(2, info,
1502			  "RA from local address detected on dev: %s: router info ignored.\n",
1503			  skb->dev->name);
1504		goto skip_routeinfo;
1505	}
1506
1507	if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1508		struct nd_opt_hdr *p;
1509		for (p = ndopts.nd_opts_ri;
1510		     p;
1511		     p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1512			struct route_info *ri = (struct route_info *)p;
1513#ifdef CONFIG_IPV6_NDISC_NODETYPE
1514			if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1515			    ri->prefix_len == 0)
1516				continue;
1517#endif
1518			if (ri->prefix_len == 0 &&
1519			    !in6_dev->cnf.accept_ra_defrtr)
1520				continue;
1521			if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1522				continue;
1523			if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1524				continue;
1525			rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1526				      &ipv6_hdr(skb)->saddr);
1527		}
1528	}
1529
1530skip_routeinfo:
1531#endif
1532
1533#ifdef CONFIG_IPV6_NDISC_NODETYPE
1534	/* skip link-specific ndopts from interior routers */
1535	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1536		ND_PRINTK(2, info,
1537			  "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1538			  __func__, skb->dev->name);
1539		goto out;
1540	}
1541#endif
1542
1543	if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1544		struct nd_opt_hdr *p;
1545		for (p = ndopts.nd_opts_pi;
1546		     p;
1547		     p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1548			addrconf_prefix_rcv(skb->dev, (u8 *)p,
1549					    (p->nd_opt_len) << 3,
1550					    ndopts.nd_opts_src_lladdr != NULL);
1551		}
1552	}
1553
1554	if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1555		__be32 n;
1556		u32 mtu;
1557
1558		memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1559		mtu = ntohl(n);
1560
1561		if (in6_dev->ra_mtu != mtu) {
1562			in6_dev->ra_mtu = mtu;
1563			send_ifinfo_notify = true;
1564		}
1565
1566		if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1567			ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1568		} else if (in6_dev->cnf.mtu6 != mtu) {
1569			in6_dev->cnf.mtu6 = mtu;
1570			fib6_metric_set(rt, RTAX_MTU, mtu);
 
 
 
1571			rt6_mtu_change(skb->dev, mtu);
1572		}
1573	}
1574
1575	if (ndopts.nd_useropts) {
1576		struct nd_opt_hdr *p;
1577		for (p = ndopts.nd_useropts;
1578		     p;
1579		     p = ndisc_next_useropt(skb->dev, p,
1580					    ndopts.nd_useropts_end)) {
1581			ndisc_ra_useropt(skb, p);
1582		}
1583	}
1584
1585	if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1586		ND_PRINTK(2, warn, "RA: invalid RA options\n");
1587	}
1588out:
1589	/* Send a notify if RA changed managed/otherconf flags or
1590	 * timer settings or ra_mtu value
1591	 */
1592	if (send_ifinfo_notify)
1593		inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1594
1595	fib6_info_release(rt);
1596	if (neigh)
1597		neigh_release(neigh);
1598}
1599
1600static void ndisc_redirect_rcv(struct sk_buff *skb)
1601{
1602	u8 *hdr;
1603	struct ndisc_options ndopts;
1604	struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1605	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1606				    offsetof(struct rd_msg, opt));
1607
1608#ifdef CONFIG_IPV6_NDISC_NODETYPE
1609	switch (skb->ndisc_nodetype) {
1610	case NDISC_NODETYPE_HOST:
1611	case NDISC_NODETYPE_NODEFAULT:
1612		ND_PRINTK(2, warn,
1613			  "Redirect: from host or unauthorized router\n");
1614		return;
1615	}
1616#endif
1617
1618	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1619		ND_PRINTK(2, warn,
1620			  "Redirect: source address is not link-local\n");
1621		return;
1622	}
1623
1624	if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1625		return;
1626
1627	if (!ndopts.nd_opts_rh) {
1628		ip6_redirect_no_header(skb, dev_net(skb->dev),
1629					skb->dev->ifindex);
1630		return;
1631	}
1632
1633	hdr = (u8 *)ndopts.nd_opts_rh;
1634	hdr += 8;
1635	if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1636		return;
1637
1638	icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1639}
1640
1641static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1642					   struct sk_buff *orig_skb,
1643					   int rd_len)
1644{
1645	u8 *opt = skb_put(skb, rd_len);
1646
1647	memset(opt, 0, 8);
1648	*(opt++) = ND_OPT_REDIRECT_HDR;
1649	*(opt++) = (rd_len >> 3);
1650	opt += 6;
1651
1652	skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1653		      rd_len - 8);
1654}
1655
1656void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1657{
1658	struct net_device *dev = skb->dev;
1659	struct net *net = dev_net(dev);
1660	struct sock *sk = net->ipv6.ndisc_sk;
1661	int optlen = 0;
1662	struct inet_peer *peer;
1663	struct sk_buff *buff;
1664	struct rd_msg *msg;
1665	struct in6_addr saddr_buf;
1666	struct rt6_info *rt;
1667	struct dst_entry *dst;
1668	struct flowi6 fl6;
1669	int rd_len;
1670	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1671	   ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1672	bool ret;
1673
1674	if (netif_is_l3_master(skb->dev)) {
1675		dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1676		if (!dev)
1677			return;
1678	}
1679
1680	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1681		ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1682			  dev->name);
1683		return;
1684	}
1685
1686	if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1687	    ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1688		ND_PRINTK(2, warn,
1689			  "Redirect: target address is not link-local unicast\n");
1690		return;
1691	}
1692
1693	icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1694			 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1695
1696	dst = ip6_route_output(net, NULL, &fl6);
1697	if (dst->error) {
1698		dst_release(dst);
1699		return;
1700	}
1701	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1702	if (IS_ERR(dst))
1703		return;
1704
1705	rt = (struct rt6_info *) dst;
1706
1707	if (rt->rt6i_flags & RTF_GATEWAY) {
1708		ND_PRINTK(2, warn,
1709			  "Redirect: destination is not a neighbour\n");
1710		goto release;
1711	}
1712	peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1713	ret = inet_peer_xrlim_allow(peer, 1*HZ);
1714	if (peer)
1715		inet_putpeer(peer);
1716	if (!ret)
1717		goto release;
1718
1719	if (dev->addr_len) {
1720		struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1721		if (!neigh) {
1722			ND_PRINTK(2, warn,
1723				  "Redirect: no neigh for target address\n");
1724			goto release;
1725		}
1726
1727		read_lock_bh(&neigh->lock);
1728		if (neigh->nud_state & NUD_VALID) {
1729			memcpy(ha_buf, neigh->ha, dev->addr_len);
1730			read_unlock_bh(&neigh->lock);
1731			ha = ha_buf;
1732			optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1733								ops_data_buf,
1734								&ops_data);
1735		} else
1736			read_unlock_bh(&neigh->lock);
1737
1738		neigh_release(neigh);
1739	}
1740
1741	rd_len = min_t(unsigned int,
1742		       IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1743		       skb->len + 8);
1744	rd_len &= ~0x7;
1745	optlen += rd_len;
1746
1747	buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1748	if (!buff)
1749		goto release;
1750
1751	msg = skb_put(buff, sizeof(*msg));
1752	*msg = (struct rd_msg) {
1753		.icmph = {
1754			.icmp6_type = NDISC_REDIRECT,
1755		},
1756		.target = *target,
1757		.dest = ipv6_hdr(skb)->daddr,
1758	};
1759
1760	/*
1761	 *	include target_address option
1762	 */
1763
1764	if (ha)
1765		ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1766
1767	/*
1768	 *	build redirect option and copy skb over to the new packet.
1769	 */
1770
1771	if (rd_len)
1772		ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1773
1774	skb_dst_set(buff, dst);
1775	ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1776	return;
1777
1778release:
1779	dst_release(dst);
1780}
1781
1782static void pndisc_redo(struct sk_buff *skb)
1783{
1784	ndisc_recv_ns(skb);
1785	kfree_skb(skb);
1786}
1787
1788static int ndisc_is_multicast(const void *pkey)
1789{
1790	return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1791}
1792
1793static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1794{
1795	struct inet6_dev *idev = __in6_dev_get(skb->dev);
1796
1797	if (!idev)
1798		return true;
1799	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1800	    idev->cnf.suppress_frag_ndisc) {
1801		net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1802		return true;
1803	}
1804	return false;
1805}
1806
1807int ndisc_rcv(struct sk_buff *skb)
1808{
1809	struct nd_msg *msg;
1810
1811	if (ndisc_suppress_frag_ndisc(skb))
1812		return 0;
1813
1814	if (skb_linearize(skb))
1815		return 0;
1816
1817	msg = (struct nd_msg *)skb_transport_header(skb);
1818
1819	__skb_push(skb, skb->data - skb_transport_header(skb));
1820
1821	if (ipv6_hdr(skb)->hop_limit != 255) {
1822		ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1823			  ipv6_hdr(skb)->hop_limit);
1824		return 0;
1825	}
1826
1827	if (msg->icmph.icmp6_code != 0) {
1828		ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1829			  msg->icmph.icmp6_code);
1830		return 0;
1831	}
1832
 
 
1833	switch (msg->icmph.icmp6_type) {
1834	case NDISC_NEIGHBOUR_SOLICITATION:
1835		memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1836		ndisc_recv_ns(skb);
1837		break;
1838
1839	case NDISC_NEIGHBOUR_ADVERTISEMENT:
1840		ndisc_recv_na(skb);
1841		break;
1842
1843	case NDISC_ROUTER_SOLICITATION:
1844		ndisc_recv_rs(skb);
1845		break;
1846
1847	case NDISC_ROUTER_ADVERTISEMENT:
1848		ndisc_router_discovery(skb);
1849		break;
1850
1851	case NDISC_REDIRECT:
1852		ndisc_redirect_rcv(skb);
1853		break;
1854	}
1855
1856	return 0;
1857}
1858
1859static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1860{
1861	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1862	struct netdev_notifier_change_info *change_info;
1863	struct net *net = dev_net(dev);
1864	struct inet6_dev *idev;
1865	bool evict_nocarrier;
1866
1867	switch (event) {
1868	case NETDEV_CHANGEADDR:
1869		neigh_changeaddr(&nd_tbl, dev);
1870		fib6_run_gc(0, net, false);
1871		fallthrough;
1872	case NETDEV_UP:
1873		idev = in6_dev_get(dev);
1874		if (!idev)
1875			break;
1876		if (idev->cnf.ndisc_notify ||
1877		    net->ipv6.devconf_all->ndisc_notify)
1878			ndisc_send_unsol_na(dev);
1879		in6_dev_put(idev);
1880		break;
1881	case NETDEV_CHANGE:
1882		idev = in6_dev_get(dev);
1883		if (!idev)
1884			evict_nocarrier = true;
1885		else {
1886			evict_nocarrier = idev->cnf.ndisc_evict_nocarrier &&
1887					  net->ipv6.devconf_all->ndisc_evict_nocarrier;
1888			in6_dev_put(idev);
1889		}
1890
1891		change_info = ptr;
1892		if (change_info->flags_changed & IFF_NOARP)
1893			neigh_changeaddr(&nd_tbl, dev);
1894		if (evict_nocarrier && !netif_carrier_ok(dev))
1895			neigh_carrier_down(&nd_tbl, dev);
1896		break;
1897	case NETDEV_DOWN:
1898		neigh_ifdown(&nd_tbl, dev);
1899		fib6_run_gc(0, net, false);
1900		break;
1901	case NETDEV_NOTIFY_PEERS:
1902		ndisc_send_unsol_na(dev);
1903		break;
1904	default:
1905		break;
1906	}
1907
1908	return NOTIFY_DONE;
1909}
1910
1911static struct notifier_block ndisc_netdev_notifier = {
1912	.notifier_call = ndisc_netdev_event,
1913	.priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1914};
1915
1916#ifdef CONFIG_SYSCTL
1917static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1918					 const char *func, const char *dev_name)
1919{
1920	static char warncomm[TASK_COMM_LEN];
1921	static int warned;
1922	if (strcmp(warncomm, current->comm) && warned < 5) {
1923		strcpy(warncomm, current->comm);
1924		pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1925			warncomm, func,
1926			dev_name, ctl->procname,
1927			dev_name, ctl->procname);
1928		warned++;
1929	}
1930}
1931
1932int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1933		size_t *lenp, loff_t *ppos)
1934{
1935	struct net_device *dev = ctl->extra1;
1936	struct inet6_dev *idev;
1937	int ret;
1938
1939	if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1940	    (strcmp(ctl->procname, "base_reachable_time") == 0))
1941		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1942
1943	if (strcmp(ctl->procname, "retrans_time") == 0)
1944		ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1945
1946	else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1947		ret = neigh_proc_dointvec_jiffies(ctl, write,
1948						  buffer, lenp, ppos);
1949
1950	else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1951		 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1952		ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1953						     buffer, lenp, ppos);
1954	else
1955		ret = -1;
1956
1957	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1958		if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1959			idev->nd_parms->reachable_time =
1960					neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1961		idev->tstamp = jiffies;
1962		inet6_ifinfo_notify(RTM_NEWLINK, idev);
1963		in6_dev_put(idev);
1964	}
1965	return ret;
1966}
1967
1968
1969#endif
1970
1971static int __net_init ndisc_net_init(struct net *net)
1972{
1973	struct ipv6_pinfo *np;
1974	struct sock *sk;
1975	int err;
1976
1977	err = inet_ctl_sock_create(&sk, PF_INET6,
1978				   SOCK_RAW, IPPROTO_ICMPV6, net);
1979	if (err < 0) {
1980		ND_PRINTK(0, err,
1981			  "NDISC: Failed to initialize the control socket (err %d)\n",
1982			  err);
1983		return err;
1984	}
1985
1986	net->ipv6.ndisc_sk = sk;
1987
1988	np = inet6_sk(sk);
1989	np->hop_limit = 255;
1990	/* Do not loopback ndisc messages */
1991	np->mc_loop = 0;
1992
1993	return 0;
1994}
1995
1996static void __net_exit ndisc_net_exit(struct net *net)
1997{
1998	inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1999}
2000
2001static struct pernet_operations ndisc_net_ops = {
2002	.init = ndisc_net_init,
2003	.exit = ndisc_net_exit,
2004};
2005
2006int __init ndisc_init(void)
2007{
2008	int err;
2009
2010	err = register_pernet_subsys(&ndisc_net_ops);
2011	if (err)
2012		return err;
2013	/*
2014	 * Initialize the neighbour table
2015	 */
2016	neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
2017
2018#ifdef CONFIG_SYSCTL
2019	err = neigh_sysctl_register(NULL, &nd_tbl.parms,
2020				    ndisc_ifinfo_sysctl_change);
2021	if (err)
2022		goto out_unregister_pernet;
2023out:
2024#endif
2025	return err;
2026
2027#ifdef CONFIG_SYSCTL
2028out_unregister_pernet:
2029	unregister_pernet_subsys(&ndisc_net_ops);
2030	goto out;
2031#endif
2032}
2033
2034int __init ndisc_late_init(void)
2035{
2036	return register_netdevice_notifier(&ndisc_netdev_notifier);
2037}
2038
2039void ndisc_late_cleanup(void)
2040{
2041	unregister_netdevice_notifier(&ndisc_netdev_notifier);
2042}
2043
2044void ndisc_cleanup(void)
2045{
2046#ifdef CONFIG_SYSCTL
2047	neigh_sysctl_unregister(&nd_tbl.parms);
2048#endif
2049	neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
2050	unregister_pernet_subsys(&ndisc_net_ops);
2051}