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v4.6
 
   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_arp.h>
  50#include <linux/ipv6.h>
  51#include <linux/icmpv6.h>
  52#include <linux/jhash.h>
  53
  54#include <net/sock.h>
  55#include <net/snmp.h>
  56
  57#include <net/ipv6.h>
  58#include <net/protocol.h>
  59#include <net/ndisc.h>
  60#include <net/ip6_route.h>
  61#include <net/addrconf.h>
  62#include <net/icmp.h>
  63
  64#include <net/netlink.h>
  65#include <linux/rtnetlink.h>
  66
  67#include <net/flow.h>
  68#include <net/ip6_checksum.h>
  69#include <net/inet_common.h>
  70#include <net/l3mdev.h>
  71#include <linux/proc_fs.h>
  72
  73#include <linux/netfilter.h>
  74#include <linux/netfilter_ipv6.h>
  75
  76/* Set to 3 to get tracing... */
  77#define ND_DEBUG 1
  78
  79#define ND_PRINTK(val, level, fmt, ...)				\
  80do {								\
  81	if (val <= ND_DEBUG)					\
  82		net_##level##_ratelimited(fmt, ##__VA_ARGS__);	\
  83} while (0)
  84
  85static u32 ndisc_hash(const void *pkey,
  86		      const struct net_device *dev,
  87		      __u32 *hash_rnd);
  88static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
 
 
  89static int ndisc_constructor(struct neighbour *neigh);
  90static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
  91static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
  92static int pndisc_constructor(struct pneigh_entry *n);
  93static void pndisc_destructor(struct pneigh_entry *n);
  94static void pndisc_redo(struct sk_buff *skb);
 
  95
  96static const struct neigh_ops ndisc_generic_ops = {
  97	.family =		AF_INET6,
  98	.solicit =		ndisc_solicit,
  99	.error_report =		ndisc_error_report,
 100	.output =		neigh_resolve_output,
 101	.connected_output =	neigh_connected_output,
 102};
 103
 104static const struct neigh_ops ndisc_hh_ops = {
 105	.family =		AF_INET6,
 106	.solicit =		ndisc_solicit,
 107	.error_report =		ndisc_error_report,
 108	.output =		neigh_resolve_output,
 109	.connected_output =	neigh_resolve_output,
 110};
 111
 112
 113static const struct neigh_ops ndisc_direct_ops = {
 114	.family =		AF_INET6,
 115	.output =		neigh_direct_output,
 116	.connected_output =	neigh_direct_output,
 117};
 118
 119struct neigh_table nd_tbl = {
 120	.family =	AF_INET6,
 121	.key_len =	sizeof(struct in6_addr),
 122	.protocol =	cpu_to_be16(ETH_P_IPV6),
 123	.hash =		ndisc_hash,
 124	.key_eq =	ndisc_key_eq,
 125	.constructor =	ndisc_constructor,
 126	.pconstructor =	pndisc_constructor,
 127	.pdestructor =	pndisc_destructor,
 128	.proxy_redo =	pndisc_redo,
 
 
 129	.id =		"ndisc_cache",
 130	.parms = {
 131		.tbl			= &nd_tbl,
 132		.reachable_time		= ND_REACHABLE_TIME,
 133		.data = {
 134			[NEIGH_VAR_MCAST_PROBES] = 3,
 135			[NEIGH_VAR_UCAST_PROBES] = 3,
 136			[NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
 137			[NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
 138			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
 
 139			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 140			[NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024,
 141			[NEIGH_VAR_PROXY_QLEN] = 64,
 142			[NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
 143			[NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
 144		},
 145	},
 146	.gc_interval =	  30 * HZ,
 147	.gc_thresh1 =	 128,
 148	.gc_thresh2 =	 512,
 149	.gc_thresh3 =	1024,
 150};
 151EXPORT_SYMBOL_GPL(nd_tbl);
 152
 153static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data)
 
 154{
 155	int pad   = ndisc_addr_option_pad(skb->dev->type);
 156	int data_len = skb->dev->addr_len;
 157	int space = ndisc_opt_addr_space(skb->dev);
 158	u8 *opt = skb_put(skb, space);
 159
 160	opt[0] = type;
 161	opt[1] = space>>3;
 162
 163	memset(opt + 2, 0, pad);
 164	opt   += pad;
 165	space -= pad;
 166
 167	memcpy(opt+2, data, data_len);
 168	data_len += 2;
 169	opt += data_len;
 170	space -= data_len;
 171	if (space > 0)
 172		memset(opt, 0, space);
 173}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 174
 175static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
 176					    struct nd_opt_hdr *end)
 177{
 178	int type;
 179	if (!cur || !end || cur >= end)
 180		return NULL;
 181	type = cur->nd_opt_type;
 182	do {
 183		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 184	} while (cur < end && cur->nd_opt_type != type);
 185	return cur <= end && cur->nd_opt_type == type ? cur : NULL;
 186}
 187
 188static inline int ndisc_is_useropt(struct nd_opt_hdr *opt)
 
 189{
 190	return opt->nd_opt_type == ND_OPT_RDNSS ||
 191		opt->nd_opt_type == ND_OPT_DNSSL;
 
 
 
 
 192}
 193
 194static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur,
 
 195					     struct nd_opt_hdr *end)
 196{
 197	if (!cur || !end || cur >= end)
 198		return NULL;
 199	do {
 200		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 201	} while (cur < end && !ndisc_is_useropt(cur));
 202	return cur <= end && ndisc_is_useropt(cur) ? cur : NULL;
 203}
 204
 205struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
 
 206					  struct ndisc_options *ndopts)
 207{
 208	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 209
 210	if (!nd_opt || opt_len < 0 || !ndopts)
 211		return NULL;
 212	memset(ndopts, 0, sizeof(*ndopts));
 213	while (opt_len) {
 
 214		int l;
 215		if (opt_len < sizeof(struct nd_opt_hdr))
 216			return NULL;
 217		l = nd_opt->nd_opt_len << 3;
 218		if (opt_len < l || l == 0)
 219			return NULL;
 
 
 220		switch (nd_opt->nd_opt_type) {
 221		case ND_OPT_SOURCE_LL_ADDR:
 222		case ND_OPT_TARGET_LL_ADDR:
 223		case ND_OPT_MTU:
 
 224		case ND_OPT_REDIRECT_HDR:
 225			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 226				ND_PRINTK(2, warn,
 227					  "%s: duplicated ND6 option found: type=%d\n",
 228					  __func__, nd_opt->nd_opt_type);
 229			} else {
 230				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 231			}
 232			break;
 233		case ND_OPT_PREFIX_INFO:
 234			ndopts->nd_opts_pi_end = nd_opt;
 235			if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 236				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 237			break;
 238#ifdef CONFIG_IPV6_ROUTE_INFO
 239		case ND_OPT_ROUTE_INFO:
 240			ndopts->nd_opts_ri_end = nd_opt;
 241			if (!ndopts->nd_opts_ri)
 242				ndopts->nd_opts_ri = nd_opt;
 243			break;
 244#endif
 245		default:
 246			if (ndisc_is_useropt(nd_opt)) {
 247				ndopts->nd_useropts_end = nd_opt;
 248				if (!ndopts->nd_useropts)
 249					ndopts->nd_useropts = nd_opt;
 250			} else {
 251				/*
 252				 * Unknown options must be silently ignored,
 253				 * to accommodate future extension to the
 254				 * protocol.
 255				 */
 256				ND_PRINTK(2, notice,
 257					  "%s: ignored unsupported option; type=%d, len=%d\n",
 258					  __func__,
 259					  nd_opt->nd_opt_type,
 260					  nd_opt->nd_opt_len);
 261			}
 262		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 263		opt_len -= l;
 264		nd_opt = ((void *)nd_opt) + l;
 265	}
 266	return ndopts;
 267}
 268
 269int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 270{
 271	switch (dev->type) {
 272	case ARPHRD_ETHER:
 273	case ARPHRD_IEEE802:	/* Not sure. Check it later. --ANK */
 274	case ARPHRD_FDDI:
 275		ipv6_eth_mc_map(addr, buf);
 276		return 0;
 277	case ARPHRD_ARCNET:
 278		ipv6_arcnet_mc_map(addr, buf);
 279		return 0;
 280	case ARPHRD_INFINIBAND:
 281		ipv6_ib_mc_map(addr, dev->broadcast, buf);
 282		return 0;
 283	case ARPHRD_IPGRE:
 284		return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 285	default:
 286		if (dir) {
 287			memcpy(buf, dev->broadcast, dev->addr_len);
 288			return 0;
 289		}
 290	}
 291	return -EINVAL;
 292}
 293EXPORT_SYMBOL(ndisc_mc_map);
 294
 295static u32 ndisc_hash(const void *pkey,
 296		      const struct net_device *dev,
 297		      __u32 *hash_rnd)
 298{
 299	return ndisc_hashfn(pkey, dev, hash_rnd);
 300}
 301
 302static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
 303{
 304	return neigh_key_eq128(n, pkey);
 305}
 306
 307static int ndisc_constructor(struct neighbour *neigh)
 308{
 309	struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
 310	struct net_device *dev = neigh->dev;
 311	struct inet6_dev *in6_dev;
 312	struct neigh_parms *parms;
 313	bool is_multicast = ipv6_addr_is_multicast(addr);
 314
 315	in6_dev = in6_dev_get(dev);
 316	if (!in6_dev) {
 317		return -EINVAL;
 318	}
 319
 320	parms = in6_dev->nd_parms;
 321	__neigh_parms_put(neigh->parms);
 322	neigh->parms = neigh_parms_clone(parms);
 323
 324	neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 325	if (!dev->header_ops) {
 326		neigh->nud_state = NUD_NOARP;
 327		neigh->ops = &ndisc_direct_ops;
 328		neigh->output = neigh_direct_output;
 329	} else {
 330		if (is_multicast) {
 331			neigh->nud_state = NUD_NOARP;
 332			ndisc_mc_map(addr, neigh->ha, dev, 1);
 333		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 334			neigh->nud_state = NUD_NOARP;
 335			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 336			if (dev->flags&IFF_LOOPBACK)
 337				neigh->type = RTN_LOCAL;
 338		} else if (dev->flags&IFF_POINTOPOINT) {
 339			neigh->nud_state = NUD_NOARP;
 340			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 341		}
 342		if (dev->header_ops->cache)
 343			neigh->ops = &ndisc_hh_ops;
 344		else
 345			neigh->ops = &ndisc_generic_ops;
 346		if (neigh->nud_state&NUD_VALID)
 347			neigh->output = neigh->ops->connected_output;
 348		else
 349			neigh->output = neigh->ops->output;
 350	}
 351	in6_dev_put(in6_dev);
 352	return 0;
 353}
 354
 355static int pndisc_constructor(struct pneigh_entry *n)
 356{
 357	struct in6_addr *addr = (struct in6_addr *)&n->key;
 358	struct in6_addr maddr;
 359	struct net_device *dev = n->dev;
 360
 361	if (!dev || !__in6_dev_get(dev))
 362		return -EINVAL;
 363	addrconf_addr_solict_mult(addr, &maddr);
 364	ipv6_dev_mc_inc(dev, &maddr);
 365	return 0;
 366}
 367
 368static void pndisc_destructor(struct pneigh_entry *n)
 369{
 370	struct in6_addr *addr = (struct in6_addr *)&n->key;
 371	struct in6_addr maddr;
 372	struct net_device *dev = n->dev;
 373
 374	if (!dev || !__in6_dev_get(dev))
 375		return;
 376	addrconf_addr_solict_mult(addr, &maddr);
 377	ipv6_dev_mc_dec(dev, &maddr);
 378}
 379
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 380static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 381				       int len)
 382{
 383	int hlen = LL_RESERVED_SPACE(dev);
 384	int tlen = dev->needed_tailroom;
 385	struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
 386	struct sk_buff *skb;
 387
 388	skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
 389	if (!skb) {
 390		ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
 391			  __func__);
 392		return NULL;
 393	}
 394
 395	skb->protocol = htons(ETH_P_IPV6);
 396	skb->dev = dev;
 397
 398	skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
 399	skb_reset_transport_header(skb);
 400
 401	/* Manually assign socket ownership as we avoid calling
 402	 * sock_alloc_send_pskb() to bypass wmem buffer limits
 403	 */
 404	skb_set_owner_w(skb, sk);
 
 
 405
 406	return skb;
 407}
 408
 409static void ip6_nd_hdr(struct sk_buff *skb,
 410		       const struct in6_addr *saddr,
 411		       const struct in6_addr *daddr,
 412		       int hop_limit, int len)
 413{
 414	struct ipv6hdr *hdr;
 
 
 
 
 
 
 
 415
 416	skb_push(skb, sizeof(*hdr));
 417	skb_reset_network_header(skb);
 418	hdr = ipv6_hdr(skb);
 419
 420	ip6_flow_hdr(hdr, 0, 0);
 421
 422	hdr->payload_len = htons(len);
 423	hdr->nexthdr = IPPROTO_ICMPV6;
 424	hdr->hop_limit = hop_limit;
 425
 426	hdr->saddr = *saddr;
 427	hdr->daddr = *daddr;
 428}
 429
 430static void ndisc_send_skb(struct sk_buff *skb,
 431			   const struct in6_addr *daddr,
 432			   const struct in6_addr *saddr)
 433{
 
 434	struct dst_entry *dst = skb_dst(skb);
 435	struct net *net = dev_net(skb->dev);
 436	struct sock *sk = net->ipv6.ndisc_sk;
 437	struct inet6_dev *idev;
 
 
 438	int err;
 439	struct icmp6hdr *icmp6h = icmp6_hdr(skb);
 440	u8 type;
 441
 442	type = icmp6h->icmp6_type;
 443
 
 
 
 
 444	if (!dst) {
 445		struct flowi6 fl6;
 446		int oif = l3mdev_fib_oif(skb->dev);
 447
 448		icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
 449		if (oif != skb->dev->ifindex)
 450			fl6.flowi6_flags |= FLOWI_FLAG_L3MDEV_SRC;
 451		dst = icmp6_dst_alloc(skb->dev, &fl6);
 452		if (IS_ERR(dst)) {
 
 453			kfree_skb(skb);
 454			return;
 455		}
 456
 457		skb_dst_set(skb, dst);
 458	}
 459
 460	icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
 461					      IPPROTO_ICMPV6,
 462					      csum_partial(icmp6h,
 463							   skb->len, 0));
 464
 465	ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
 466
 467	rcu_read_lock();
 468	idev = __in6_dev_get(dst->dev);
 469	IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 470
 471	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
 472		      net, sk, skb, NULL, dst->dev,
 473		      dst_output);
 474	if (!err) {
 475		ICMP6MSGOUT_INC_STATS(net, idev, type);
 476		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 477	}
 478
 479	rcu_read_unlock();
 480}
 
 481
 482void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 483		   const struct in6_addr *solicited_addr,
 484		   bool router, bool solicited, bool override, bool inc_opt)
 485{
 486	struct sk_buff *skb;
 487	struct in6_addr tmpaddr;
 488	struct inet6_ifaddr *ifp;
 489	const struct in6_addr *src_addr;
 490	struct nd_msg *msg;
 491	int optlen = 0;
 492
 493	/* for anycast or proxy, solicited_addr != src_addr */
 494	ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 495	if (ifp) {
 496		src_addr = solicited_addr;
 497		if (ifp->flags & IFA_F_OPTIMISTIC)
 498			override = false;
 499		inc_opt |= ifp->idev->cnf.force_tllao;
 500		in6_ifa_put(ifp);
 501	} else {
 502		if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 503				       inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 504				       &tmpaddr))
 505			return;
 506		src_addr = &tmpaddr;
 507	}
 508
 509	if (!dev->addr_len)
 510		inc_opt = 0;
 511	if (inc_opt)
 512		optlen += ndisc_opt_addr_space(dev);
 
 513
 514	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 515	if (!skb)
 516		return;
 517
 518	msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
 519	*msg = (struct nd_msg) {
 520		.icmph = {
 521			.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 522			.icmp6_router = router,
 523			.icmp6_solicited = solicited,
 524			.icmp6_override = override,
 525		},
 526		.target = *solicited_addr,
 527	};
 528
 529	if (inc_opt)
 530		ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 531				       dev->dev_addr);
 532
 533
 534	ndisc_send_skb(skb, daddr, src_addr);
 535}
 536
 537static void ndisc_send_unsol_na(struct net_device *dev)
 538{
 539	struct inet6_dev *idev;
 540	struct inet6_ifaddr *ifa;
 541
 542	idev = in6_dev_get(dev);
 543	if (!idev)
 544		return;
 545
 546	read_lock_bh(&idev->lock);
 547	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 
 
 
 
 
 548		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
 549			      /*router=*/ !!idev->cnf.forwarding,
 550			      /*solicited=*/ false, /*override=*/ true,
 551			      /*inc_opt=*/ true);
 552	}
 553	read_unlock_bh(&idev->lock);
 554
 555	in6_dev_put(idev);
 556}
 557
 558void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 559		   const struct in6_addr *daddr, const struct in6_addr *saddr)
 560{
 561	struct sk_buff *skb;
 562	struct in6_addr addr_buf;
 563	int inc_opt = dev->addr_len;
 564	int optlen = 0;
 565	struct nd_msg *msg;
 
 566
 567	if (!saddr) {
 568		if (ipv6_get_lladdr(dev, &addr_buf,
 569				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
 570			return;
 571		saddr = &addr_buf;
 572	}
 573
 574	if (ipv6_addr_any(saddr))
 575		inc_opt = false;
 576	if (inc_opt)
 577		optlen += ndisc_opt_addr_space(dev);
 
 
 
 578
 579	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 580	if (!skb)
 581		return;
 582
 583	msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
 584	*msg = (struct nd_msg) {
 585		.icmph = {
 586			.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 587		},
 588		.target = *solicit,
 589	};
 590
 591	if (inc_opt)
 592		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 593				       dev->dev_addr);
 
 
 
 
 
 
 
 
 594
 595	ndisc_send_skb(skb, daddr, saddr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 596}
 597
 598void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 599		   const struct in6_addr *daddr)
 600{
 601	struct sk_buff *skb;
 602	struct rs_msg *msg;
 603	int send_sllao = dev->addr_len;
 604	int optlen = 0;
 605
 606#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 607	/*
 608	 * According to section 2.2 of RFC 4429, we must not
 609	 * send router solicitations with a sllao from
 610	 * optimistic addresses, but we may send the solicitation
 611	 * if we don't include the sllao.  So here we check
 612	 * if our address is optimistic, and if so, we
 613	 * suppress the inclusion of the sllao.
 614	 */
 615	if (send_sllao) {
 616		struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 617							   dev, 1);
 618		if (ifp) {
 619			if (ifp->flags & IFA_F_OPTIMISTIC)  {
 620				send_sllao = 0;
 621			}
 622			in6_ifa_put(ifp);
 623		} else {
 624			send_sllao = 0;
 625		}
 626	}
 627#endif
 628	if (send_sllao)
 629		optlen += ndisc_opt_addr_space(dev);
 630
 631	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 632	if (!skb)
 633		return;
 634
 635	msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
 636	*msg = (struct rs_msg) {
 637		.icmph = {
 638			.icmp6_type = NDISC_ROUTER_SOLICITATION,
 639		},
 640	};
 641
 642	if (send_sllao)
 643		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 644				       dev->dev_addr);
 
 645
 646	ndisc_send_skb(skb, daddr, saddr);
 647}
 648
 649
 650static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 651{
 652	/*
 653	 *	"The sender MUST return an ICMP
 654	 *	 destination unreachable"
 655	 */
 656	dst_link_failure(skb);
 657	kfree_skb(skb);
 658}
 659
 660/* Called with locked neigh: either read or both */
 661
 662static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 663{
 664	struct in6_addr *saddr = NULL;
 665	struct in6_addr mcaddr;
 666	struct net_device *dev = neigh->dev;
 667	struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 668	int probes = atomic_read(&neigh->probes);
 669
 670	if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
 671					   dev, 1,
 672					   IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
 673		saddr = &ipv6_hdr(skb)->saddr;
 674	probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
 675	if (probes < 0) {
 676		if (!(neigh->nud_state & NUD_VALID)) {
 677			ND_PRINTK(1, dbg,
 678				  "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
 679				  __func__, target);
 680		}
 681		ndisc_send_ns(dev, target, target, saddr);
 682	} else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
 683		neigh_app_ns(neigh);
 684	} else {
 685		addrconf_addr_solict_mult(target, &mcaddr);
 686		ndisc_send_ns(dev, target, &mcaddr, saddr);
 687	}
 688}
 689
 690static int pndisc_is_router(const void *pkey,
 691			    struct net_device *dev)
 692{
 693	struct pneigh_entry *n;
 694	int ret = -1;
 695
 696	read_lock_bh(&nd_tbl.lock);
 697	n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 698	if (n)
 699		ret = !!(n->flags & NTF_ROUTER);
 700	read_unlock_bh(&nd_tbl.lock);
 701
 702	return ret;
 703}
 704
 705static void ndisc_recv_ns(struct sk_buff *skb)
 
 
 
 
 
 
 
 
 
 706{
 707	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 708	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 709	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 710	u8 *lladdr = NULL;
 711	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 712				    offsetof(struct nd_msg, opt));
 713	struct ndisc_options ndopts;
 714	struct net_device *dev = skb->dev;
 715	struct inet6_ifaddr *ifp;
 716	struct inet6_dev *idev = NULL;
 717	struct neighbour *neigh;
 718	int dad = ipv6_addr_any(saddr);
 719	bool inc;
 720	int is_router = -1;
 
 
 
 721
 722	if (skb->len < sizeof(struct nd_msg)) {
 723		ND_PRINTK(2, warn, "NS: packet too short\n");
 724		return;
 725	}
 726
 727	if (ipv6_addr_is_multicast(&msg->target)) {
 728		ND_PRINTK(2, warn, "NS: multicast target address\n");
 729		return;
 730	}
 731
 732	/*
 733	 * RFC2461 7.1.1:
 734	 * DAD has to be destined for solicited node multicast address.
 735	 */
 736	if (dad && !ipv6_addr_is_solict_mult(daddr)) {
 737		ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
 738		return;
 739	}
 740
 741	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 742		ND_PRINTK(2, warn, "NS: invalid ND options\n");
 743		return;
 744	}
 745
 746	if (ndopts.nd_opts_src_lladdr) {
 747		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 748		if (!lladdr) {
 749			ND_PRINTK(2, warn,
 750				  "NS: invalid link-layer address length\n");
 751			return;
 752		}
 753
 754		/* RFC2461 7.1.1:
 755		 *	If the IP source address is the unspecified address,
 756		 *	there MUST NOT be source link-layer address option
 757		 *	in the message.
 758		 */
 759		if (dad) {
 760			ND_PRINTK(2, warn,
 761				  "NS: bad DAD packet (link-layer address option)\n");
 762			return;
 763		}
 764	}
 
 
 765
 766	inc = ipv6_addr_is_multicast(daddr);
 767
 768	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 769	if (ifp) {
 770have_ifp:
 771		if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 772			if (dad) {
 
 
 
 
 
 
 
 
 
 773				/*
 774				 * We are colliding with another node
 775				 * who is doing DAD
 776				 * so fail our DAD process
 777				 */
 778				addrconf_dad_failure(ifp);
 779				return;
 780			} else {
 781				/*
 782				 * This is not a dad solicitation.
 783				 * If we are an optimistic node,
 784				 * we should respond.
 785				 * Otherwise, we should ignore it.
 786				 */
 787				if (!(ifp->flags & IFA_F_OPTIMISTIC))
 788					goto out;
 789			}
 790		}
 791
 792		idev = ifp->idev;
 793	} else {
 794		struct net *net = dev_net(dev);
 795
 796		/* perhaps an address on the master device */
 797		if (netif_is_l3_slave(dev)) {
 798			struct net_device *mdev;
 799
 800			mdev = netdev_master_upper_dev_get_rcu(dev);
 801			if (mdev) {
 802				ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
 803				if (ifp)
 804					goto have_ifp;
 805			}
 806		}
 807
 808		idev = in6_dev_get(dev);
 809		if (!idev) {
 810			/* XXX: count this drop? */
 811			return;
 812		}
 813
 814		if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 815		    (idev->cnf.forwarding &&
 816		     (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
 
 817		     (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 818			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 819			    skb->pkt_type != PACKET_HOST &&
 820			    inc &&
 821			    NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
 822				/*
 823				 * for anycast or proxy,
 824				 * sender should delay its response
 825				 * by a random time between 0 and
 826				 * MAX_ANYCAST_DELAY_TIME seconds.
 827				 * (RFC2461) -- yoshfuji
 828				 */
 829				struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 830				if (n)
 831					pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 832				goto out;
 833			}
 834		} else
 
 835			goto out;
 
 836	}
 837
 838	if (is_router < 0)
 839		is_router = idev->cnf.forwarding;
 840
 841	if (dad) {
 842		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
 843			      !!is_router, false, (ifp != NULL), true);
 844		goto out;
 845	}
 846
 847	if (inc)
 848		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 849	else
 850		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 851
 852	/*
 853	 *	update / create cache entry
 854	 *	for the source address
 855	 */
 856	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 857			       !inc || lladdr || !dev->addr_len);
 858	if (neigh)
 859		neigh_update(neigh, lladdr, NUD_STALE,
 860			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 861			     NEIGH_UPDATE_F_OVERRIDE);
 
 862	if (neigh || !dev->header_ops) {
 863		ndisc_send_na(dev, saddr, &msg->target, !!is_router,
 864			      true, (ifp != NULL && inc), inc);
 865		if (neigh)
 866			neigh_release(neigh);
 
 867	}
 868
 869out:
 870	if (ifp)
 871		in6_ifa_put(ifp);
 872	else
 873		in6_dev_put(idev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 874}
 875
 876static void ndisc_recv_na(struct sk_buff *skb)
 877{
 878	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 879	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 880	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 881	u8 *lladdr = NULL;
 882	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 883				    offsetof(struct nd_msg, opt));
 884	struct ndisc_options ndopts;
 885	struct net_device *dev = skb->dev;
 886	struct inet6_dev *idev = __in6_dev_get(dev);
 887	struct inet6_ifaddr *ifp;
 888	struct neighbour *neigh;
 
 
 889
 890	if (skb->len < sizeof(struct nd_msg)) {
 891		ND_PRINTK(2, warn, "NA: packet too short\n");
 892		return;
 893	}
 894
 895	if (ipv6_addr_is_multicast(&msg->target)) {
 896		ND_PRINTK(2, warn, "NA: target address is multicast\n");
 897		return;
 898	}
 899
 900	if (ipv6_addr_is_multicast(daddr) &&
 901	    msg->icmph.icmp6_solicited) {
 902		ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
 903		return;
 904	}
 905
 906	/* For some 802.11 wireless deployments (and possibly other networks),
 907	 * there will be a NA proxy and unsolicitd packets are attacks
 908	 * and thus should not be accepted.
 
 909	 */
 910	if (!msg->icmph.icmp6_solicited && idev &&
 911	    idev->cnf.drop_unsolicited_na)
 912		return;
 
 
 
 913
 914	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
 915		ND_PRINTK(2, warn, "NS: invalid ND option\n");
 916		return;
 917	}
 918	if (ndopts.nd_opts_tgt_lladdr) {
 919		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 920		if (!lladdr) {
 921			ND_PRINTK(2, warn,
 922				  "NA: invalid link-layer address length\n");
 923			return;
 924		}
 925	}
 926	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 927	if (ifp) {
 928		if (skb->pkt_type != PACKET_LOOPBACK
 929		    && (ifp->flags & IFA_F_TENTATIVE)) {
 930				addrconf_dad_failure(ifp);
 931				return;
 932		}
 933		/* What should we make now? The advertisement
 934		   is invalid, but ndisc specs say nothing
 935		   about it. It could be misconfiguration, or
 936		   an smart proxy agent tries to help us :-)
 937
 938		   We should not print the error if NA has been
 939		   received from loopback - it is just our own
 940		   unsolicited advertisement.
 941		 */
 942		if (skb->pkt_type != PACKET_LOOPBACK)
 943			ND_PRINTK(1, warn,
 944				  "NA: someone advertises our address %pI6 on %s!\n",
 945				  &ifp->addr, ifp->idev->dev->name);
 946		in6_ifa_put(ifp);
 947		return;
 948	}
 
 949	neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
 950
 951	if (neigh) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 952		u8 old_flags = neigh->flags;
 953		struct net *net = dev_net(dev);
 954
 955		if (neigh->nud_state & NUD_FAILED)
 956			goto out;
 957
 958		/*
 959		 * Don't update the neighbor cache entry on a proxy NA from
 960		 * ourselves because either the proxied node is off link or it
 961		 * has already sent a NA to us.
 962		 */
 963		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
 964		    net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
 
 965		    pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
 966			/* XXX: idev->cnf.proxy_ndp */
 967			goto out;
 968		}
 969
 970		neigh_update(neigh, lladdr,
 971			     msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
 972			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 973			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
 974			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
 975			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));
 
 976
 977		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
 978			/*
 979			 * Change: router to host
 980			 */
 981			rt6_clean_tohost(dev_net(dev),  saddr);
 982		}
 983
 984out:
 985		neigh_release(neigh);
 986	}
 
 987}
 988
 989static void ndisc_recv_rs(struct sk_buff *skb)
 990{
 991	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
 992	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
 993	struct neighbour *neigh;
 994	struct inet6_dev *idev;
 995	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 996	struct ndisc_options ndopts;
 997	u8 *lladdr = NULL;
 
 998
 999	if (skb->len < sizeof(*rs_msg))
1000		return;
1001
1002	idev = __in6_dev_get(skb->dev);
1003	if (!idev) {
1004		ND_PRINTK(1, err, "RS: can't find in6 device\n");
1005		return;
1006	}
1007
1008	/* Don't accept RS if we're not in router mode */
1009	if (!idev->cnf.forwarding)
1010		goto out;
1011
1012	/*
1013	 * Don't update NCE if src = ::;
1014	 * this implies that the source node has no ip address assigned yet.
1015	 */
1016	if (ipv6_addr_any(saddr))
1017		goto out;
1018
1019	/* Parse ND options */
1020	if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
1021		ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1022		goto out;
1023	}
1024
1025	if (ndopts.nd_opts_src_lladdr) {
1026		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1027					     skb->dev);
1028		if (!lladdr)
1029			goto out;
1030	}
1031
1032	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1033	if (neigh) {
1034		neigh_update(neigh, lladdr, NUD_STALE,
1035			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1036			     NEIGH_UPDATE_F_OVERRIDE|
1037			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
 
1038		neigh_release(neigh);
 
1039	}
1040out:
1041	return;
1042}
1043
1044static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1045{
1046	struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1047	struct sk_buff *skb;
1048	struct nlmsghdr *nlh;
1049	struct nduseroptmsg *ndmsg;
1050	struct net *net = dev_net(ra->dev);
1051	int err;
1052	int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1053				    + (opt->nd_opt_len << 3));
1054	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1055
1056	skb = nlmsg_new(msg_size, GFP_ATOMIC);
1057	if (!skb) {
1058		err = -ENOBUFS;
1059		goto errout;
1060	}
1061
1062	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1063	if (!nlh) {
1064		goto nla_put_failure;
1065	}
1066
1067	ndmsg = nlmsg_data(nlh);
1068	ndmsg->nduseropt_family = AF_INET6;
1069	ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1070	ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1071	ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1072	ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1073
1074	memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1075
1076	if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1077		goto nla_put_failure;
1078	nlmsg_end(skb, nlh);
1079
1080	rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1081	return;
1082
1083nla_put_failure:
1084	nlmsg_free(skb);
1085	err = -EMSGSIZE;
1086errout:
1087	rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1088}
1089
1090static void ndisc_router_discovery(struct sk_buff *skb)
1091{
1092	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
 
1093	struct neighbour *neigh = NULL;
1094	struct inet6_dev *in6_dev;
1095	struct rt6_info *rt = NULL;
1096	int lifetime;
1097	struct ndisc_options ndopts;
1098	int optlen;
 
 
 
1099	unsigned int pref = 0;
1100	__u32 old_if_flags;
1101	bool send_ifinfo_notify = false;
 
 
 
1102
1103	__u8 *opt = (__u8 *)(ra_msg + 1);
1104
1105	optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1106		sizeof(struct ra_msg);
1107
1108	ND_PRINTK(2, info,
1109		  "RA: %s, dev: %s\n",
1110		  __func__, skb->dev->name);
1111	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1112		ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1113		return;
1114	}
1115	if (optlen < 0) {
1116		ND_PRINTK(2, warn, "RA: packet too short\n");
1117		return;
1118	}
 
 
1119
1120#ifdef CONFIG_IPV6_NDISC_NODETYPE
1121	if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1122		ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1123		return;
1124	}
1125#endif
1126
1127	/*
1128	 *	set the RA_RECV flag in the interface
1129	 */
1130
1131	in6_dev = __in6_dev_get(skb->dev);
1132	if (!in6_dev) {
1133		ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1134			  skb->dev->name);
1135		return;
1136	}
1137
1138	if (!ndisc_parse_options(opt, optlen, &ndopts)) {
1139		ND_PRINTK(2, warn, "RA: invalid ND options\n");
1140		return;
1141	}
1142
1143	if (!ipv6_accept_ra(in6_dev)) {
1144		ND_PRINTK(2, info,
1145			  "RA: %s, did not accept ra for dev: %s\n",
1146			  __func__, skb->dev->name);
1147		goto skip_linkparms;
1148	}
1149
1150#ifdef CONFIG_IPV6_NDISC_NODETYPE
1151	/* skip link-specific parameters from interior routers */
1152	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1153		ND_PRINTK(2, info,
1154			  "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1155			  __func__, skb->dev->name);
1156		goto skip_linkparms;
1157	}
1158#endif
1159
1160	if (in6_dev->if_flags & IF_RS_SENT) {
1161		/*
1162		 *	flag that an RA was received after an RS was sent
1163		 *	out on this interface.
1164		 */
1165		in6_dev->if_flags |= IF_RA_RCVD;
1166	}
1167
1168	/*
1169	 * Remember the managed/otherconf flags from most recently
1170	 * received RA message (RFC 2462) -- yoshfuji
1171	 */
1172	old_if_flags = in6_dev->if_flags;
1173	in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1174				IF_RA_OTHERCONF)) |
1175				(ra_msg->icmph.icmp6_addrconf_managed ?
1176					IF_RA_MANAGED : 0) |
1177				(ra_msg->icmph.icmp6_addrconf_other ?
1178					IF_RA_OTHERCONF : 0);
1179
1180	if (old_if_flags != in6_dev->if_flags)
1181		send_ifinfo_notify = true;
1182
1183	if (!in6_dev->cnf.accept_ra_defrtr) {
1184		ND_PRINTK(2, info,
1185			  "RA: %s, defrtr is false for dev: %s\n",
1186			  __func__, skb->dev->name);
1187		goto skip_defrtr;
1188	}
1189
 
 
 
 
 
 
 
 
 
1190	/* Do not accept RA with source-addr found on local machine unless
1191	 * accept_ra_from_local is set to true.
1192	 */
1193	if (!in6_dev->cnf.accept_ra_from_local &&
1194	    ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1195			  in6_dev->dev, 0)) {
1196		ND_PRINTK(2, info,
1197			  "RA from local address detected on dev: %s: default router ignored\n",
1198			  skb->dev->name);
1199		goto skip_defrtr;
1200	}
1201
1202	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1203
1204#ifdef CONFIG_IPV6_ROUTER_PREF
1205	pref = ra_msg->icmph.icmp6_router_pref;
1206	/* 10b is handled as if it were 00b (medium) */
1207	if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1208	    !in6_dev->cnf.accept_ra_rtr_pref)
1209		pref = ICMPV6_ROUTER_PREF_MEDIUM;
1210#endif
1211
1212	rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
1213
1214	if (rt) {
1215		neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
 
 
1216		if (!neigh) {
1217			ND_PRINTK(0, err,
1218				  "RA: %s got default router without neighbour\n",
1219				  __func__);
1220			ip6_rt_put(rt);
1221			return;
1222		}
1223	}
1224	if (rt && lifetime == 0) {
1225		ip6_del_rt(rt);
 
 
 
1226		rt = NULL;
1227	}
1228
1229	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, for dev: %s\n",
1230		  rt, lifetime, skb->dev->name);
1231	if (!rt && lifetime) {
1232		ND_PRINTK(3, info, "RA: adding default router\n");
1233
1234		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
 
 
 
 
 
1235		if (!rt) {
1236			ND_PRINTK(0, err,
1237				  "RA: %s failed to add default route\n",
1238				  __func__);
1239			return;
1240		}
1241
1242		neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr);
 
 
1243		if (!neigh) {
1244			ND_PRINTK(0, err,
1245				  "RA: %s got default router without neighbour\n",
1246				  __func__);
1247			ip6_rt_put(rt);
1248			return;
1249		}
1250		neigh->flags |= NTF_ROUTER;
1251	} else if (rt) {
1252		rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
 
 
 
 
1253	}
1254
1255	if (rt)
1256		rt6_set_expires(rt, jiffies + (HZ * lifetime));
1257	if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
 
 
 
 
 
 
 
1258	    ra_msg->icmph.icmp6_hop_limit) {
1259		if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1260			in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1261			if (rt)
1262				dst_metric_set(&rt->dst, RTAX_HOPLIMIT,
1263					       ra_msg->icmph.icmp6_hop_limit);
 
1264		} else {
1265			ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1266		}
1267	}
1268
1269skip_defrtr:
1270
1271	/*
1272	 *	Update Reachable Time and Retrans Timer
1273	 */
1274
1275	if (in6_dev->nd_parms) {
1276		unsigned long rtime = ntohl(ra_msg->retrans_timer);
1277
1278		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1279			rtime = (rtime*HZ)/1000;
1280			if (rtime < HZ/10)
1281				rtime = HZ/10;
1282			NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1283			in6_dev->tstamp = jiffies;
1284			send_ifinfo_notify = true;
1285		}
1286
1287		rtime = ntohl(ra_msg->reachable_time);
1288		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1289			rtime = (rtime*HZ)/1000;
1290
1291			if (rtime < HZ/10)
1292				rtime = HZ/10;
1293
1294			if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1295				NEIGH_VAR_SET(in6_dev->nd_parms,
1296					      BASE_REACHABLE_TIME, rtime);
1297				NEIGH_VAR_SET(in6_dev->nd_parms,
1298					      GC_STALETIME, 3 * rtime);
1299				in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1300				in6_dev->tstamp = jiffies;
1301				send_ifinfo_notify = true;
1302			}
1303		}
1304	}
1305
1306	/*
1307	 *	Send a notify if RA changed managed/otherconf flags or timer settings
1308	 */
1309	if (send_ifinfo_notify)
1310		inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1311
1312skip_linkparms:
1313
1314	/*
1315	 *	Process options.
1316	 */
1317
1318	if (!neigh)
1319		neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1320				       skb->dev, 1);
1321	if (neigh) {
1322		u8 *lladdr = NULL;
1323		if (ndopts.nd_opts_src_lladdr) {
1324			lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1325						     skb->dev);
1326			if (!lladdr) {
1327				ND_PRINTK(2, warn,
1328					  "RA: invalid link-layer address length\n");
1329				goto out;
1330			}
1331		}
1332		neigh_update(neigh, lladdr, NUD_STALE,
1333			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1334			     NEIGH_UPDATE_F_OVERRIDE|
1335			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1336			     NEIGH_UPDATE_F_ISROUTER);
 
 
1337	}
1338
1339	if (!ipv6_accept_ra(in6_dev)) {
1340		ND_PRINTK(2, info,
1341			  "RA: %s, accept_ra is false for dev: %s\n",
1342			  __func__, skb->dev->name);
1343		goto out;
1344	}
1345
1346#ifdef CONFIG_IPV6_ROUTE_INFO
1347	if (!in6_dev->cnf.accept_ra_from_local &&
1348	    ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1349			  in6_dev->dev, 0)) {
1350		ND_PRINTK(2, info,
1351			  "RA from local address detected on dev: %s: router info ignored.\n",
1352			  skb->dev->name);
1353		goto skip_routeinfo;
1354	}
1355
1356	if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1357		struct nd_opt_hdr *p;
1358		for (p = ndopts.nd_opts_ri;
1359		     p;
1360		     p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1361			struct route_info *ri = (struct route_info *)p;
1362#ifdef CONFIG_IPV6_NDISC_NODETYPE
1363			if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1364			    ri->prefix_len == 0)
1365				continue;
1366#endif
1367			if (ri->prefix_len == 0 &&
1368			    !in6_dev->cnf.accept_ra_defrtr)
 
 
 
1369				continue;
1370			if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
 
 
1371				continue;
1372			rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1373				      &ipv6_hdr(skb)->saddr);
1374		}
1375	}
1376
1377skip_routeinfo:
1378#endif
1379
1380#ifdef CONFIG_IPV6_NDISC_NODETYPE
1381	/* skip link-specific ndopts from interior routers */
1382	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1383		ND_PRINTK(2, info,
1384			  "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1385			  __func__, skb->dev->name);
1386		goto out;
1387	}
1388#endif
1389
1390	if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1391		struct nd_opt_hdr *p;
1392		for (p = ndopts.nd_opts_pi;
1393		     p;
1394		     p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1395			addrconf_prefix_rcv(skb->dev, (u8 *)p,
1396					    (p->nd_opt_len) << 3,
1397					    ndopts.nd_opts_src_lladdr != NULL);
1398		}
1399	}
1400
1401	if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1402		__be32 n;
1403		u32 mtu;
1404
1405		memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1406		mtu = ntohl(n);
1407
 
 
 
 
 
1408		if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1409			ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1410		} else if (in6_dev->cnf.mtu6 != mtu) {
1411			in6_dev->cnf.mtu6 = mtu;
1412
1413			if (rt)
1414				dst_metric_set(&rt->dst, RTAX_MTU, mtu);
1415
1416			rt6_mtu_change(skb->dev, mtu);
1417		}
1418	}
1419
1420	if (ndopts.nd_useropts) {
1421		struct nd_opt_hdr *p;
1422		for (p = ndopts.nd_useropts;
1423		     p;
1424		     p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) {
 
1425			ndisc_ra_useropt(skb, p);
1426		}
1427	}
1428
1429	if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1430		ND_PRINTK(2, warn, "RA: invalid RA options\n");
1431	}
1432out:
1433	ip6_rt_put(rt);
 
 
 
 
 
 
1434	if (neigh)
1435		neigh_release(neigh);
 
1436}
1437
1438static void ndisc_redirect_rcv(struct sk_buff *skb)
1439{
1440	u8 *hdr;
1441	struct ndisc_options ndopts;
1442	struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1443	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1444				    offsetof(struct rd_msg, opt));
 
 
 
1445
1446#ifdef CONFIG_IPV6_NDISC_NODETYPE
1447	switch (skb->ndisc_nodetype) {
1448	case NDISC_NODETYPE_HOST:
1449	case NDISC_NODETYPE_NODEFAULT:
1450		ND_PRINTK(2, warn,
1451			  "Redirect: from host or unauthorized router\n");
1452		return;
1453	}
1454#endif
1455
1456	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1457		ND_PRINTK(2, warn,
1458			  "Redirect: source address is not link-local\n");
1459		return;
1460	}
1461
1462	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts))
1463		return;
1464
1465	if (!ndopts.nd_opts_rh) {
1466		ip6_redirect_no_header(skb, dev_net(skb->dev),
1467					skb->dev->ifindex, 0);
1468		return;
1469	}
1470
1471	hdr = (u8 *)ndopts.nd_opts_rh;
1472	hdr += 8;
1473	if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1474		return;
1475
1476	icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1477}
1478
1479static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1480					   struct sk_buff *orig_skb,
1481					   int rd_len)
1482{
1483	u8 *opt = skb_put(skb, rd_len);
1484
1485	memset(opt, 0, 8);
1486	*(opt++) = ND_OPT_REDIRECT_HDR;
1487	*(opt++) = (rd_len >> 3);
1488	opt += 6;
1489
1490	memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
 
1491}
1492
1493void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1494{
1495	struct net_device *dev = skb->dev;
1496	struct net *net = dev_net(dev);
1497	struct sock *sk = net->ipv6.ndisc_sk;
1498	int optlen = 0;
1499	struct inet_peer *peer;
1500	struct sk_buff *buff;
1501	struct rd_msg *msg;
1502	struct in6_addr saddr_buf;
1503	struct rt6_info *rt;
1504	struct dst_entry *dst;
1505	struct flowi6 fl6;
1506	int rd_len;
1507	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
1508	int oif = l3mdev_fib_oif(dev);
1509	bool ret;
1510
 
 
 
 
 
 
1511	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1512		ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1513			  dev->name);
1514		return;
1515	}
1516
1517	if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1518	    ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1519		ND_PRINTK(2, warn,
1520			  "Redirect: target address is not link-local unicast\n");
1521		return;
1522	}
1523
1524	icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1525			 &saddr_buf, &ipv6_hdr(skb)->saddr, oif);
1526
1527	if (oif != skb->dev->ifindex)
1528		fl6.flowi6_flags |= FLOWI_FLAG_L3MDEV_SRC;
1529
1530	dst = ip6_route_output(net, NULL, &fl6);
1531	if (dst->error) {
1532		dst_release(dst);
1533		return;
1534	}
1535	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1536	if (IS_ERR(dst))
1537		return;
1538
1539	rt = (struct rt6_info *) dst;
1540
1541	if (rt->rt6i_flags & RTF_GATEWAY) {
1542		ND_PRINTK(2, warn,
1543			  "Redirect: destination is not a neighbour\n");
1544		goto release;
1545	}
1546	peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
 
 
1547	ret = inet_peer_xrlim_allow(peer, 1*HZ);
1548	if (peer)
1549		inet_putpeer(peer);
1550	if (!ret)
1551		goto release;
1552
1553	if (dev->addr_len) {
1554		struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1555		if (!neigh) {
1556			ND_PRINTK(2, warn,
1557				  "Redirect: no neigh for target address\n");
1558			goto release;
1559		}
1560
1561		read_lock_bh(&neigh->lock);
1562		if (neigh->nud_state & NUD_VALID) {
1563			memcpy(ha_buf, neigh->ha, dev->addr_len);
1564			read_unlock_bh(&neigh->lock);
1565			ha = ha_buf;
1566			optlen += ndisc_opt_addr_space(dev);
 
 
1567		} else
1568			read_unlock_bh(&neigh->lock);
1569
1570		neigh_release(neigh);
1571	}
1572
1573	rd_len = min_t(unsigned int,
1574		       IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1575		       skb->len + 8);
1576	rd_len &= ~0x7;
1577	optlen += rd_len;
1578
1579	buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1580	if (!buff)
1581		goto release;
1582
1583	msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
1584	*msg = (struct rd_msg) {
1585		.icmph = {
1586			.icmp6_type = NDISC_REDIRECT,
1587		},
1588		.target = *target,
1589		.dest = ipv6_hdr(skb)->daddr,
1590	};
1591
1592	/*
1593	 *	include target_address option
1594	 */
1595
1596	if (ha)
1597		ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha);
1598
1599	/*
1600	 *	build redirect option and copy skb over to the new packet.
1601	 */
1602
1603	if (rd_len)
1604		ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1605
1606	skb_dst_set(buff, dst);
1607	ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1608	return;
1609
1610release:
1611	dst_release(dst);
1612}
1613
1614static void pndisc_redo(struct sk_buff *skb)
1615{
1616	ndisc_recv_ns(skb);
1617	kfree_skb(skb);
 
 
 
 
 
 
1618}
1619
1620static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1621{
1622	struct inet6_dev *idev = __in6_dev_get(skb->dev);
1623
1624	if (!idev)
1625		return true;
1626	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1627	    idev->cnf.suppress_frag_ndisc) {
1628		net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1629		return true;
1630	}
1631	return false;
1632}
1633
1634int ndisc_rcv(struct sk_buff *skb)
1635{
1636	struct nd_msg *msg;
 
1637
1638	if (ndisc_suppress_frag_ndisc(skb))
1639		return 0;
1640
1641	if (skb_linearize(skb))
1642		return 0;
1643
1644	msg = (struct nd_msg *)skb_transport_header(skb);
1645
1646	__skb_push(skb, skb->data - skb_transport_header(skb));
1647
1648	if (ipv6_hdr(skb)->hop_limit != 255) {
1649		ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1650			  ipv6_hdr(skb)->hop_limit);
1651		return 0;
1652	}
1653
1654	if (msg->icmph.icmp6_code != 0) {
1655		ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1656			  msg->icmph.icmp6_code);
1657		return 0;
1658	}
1659
1660	memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1661
1662	switch (msg->icmph.icmp6_type) {
1663	case NDISC_NEIGHBOUR_SOLICITATION:
1664		ndisc_recv_ns(skb);
 
1665		break;
1666
1667	case NDISC_NEIGHBOUR_ADVERTISEMENT:
1668		ndisc_recv_na(skb);
1669		break;
1670
1671	case NDISC_ROUTER_SOLICITATION:
1672		ndisc_recv_rs(skb);
1673		break;
1674
1675	case NDISC_ROUTER_ADVERTISEMENT:
1676		ndisc_router_discovery(skb);
1677		break;
1678
1679	case NDISC_REDIRECT:
1680		ndisc_redirect_rcv(skb);
1681		break;
1682	}
1683
1684	return 0;
1685}
1686
1687static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1688{
1689	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1690	struct netdev_notifier_change_info *change_info;
1691	struct net *net = dev_net(dev);
1692	struct inet6_dev *idev;
 
1693
1694	switch (event) {
1695	case NETDEV_CHANGEADDR:
1696		neigh_changeaddr(&nd_tbl, dev);
1697		fib6_run_gc(0, net, false);
 
 
1698		idev = in6_dev_get(dev);
1699		if (!idev)
1700			break;
1701		if (idev->cnf.ndisc_notify)
 
1702			ndisc_send_unsol_na(dev);
1703		in6_dev_put(idev);
1704		break;
1705	case NETDEV_CHANGE:
 
 
 
 
 
 
 
 
 
1706		change_info = ptr;
1707		if (change_info->flags_changed & IFF_NOARP)
1708			neigh_changeaddr(&nd_tbl, dev);
 
 
1709		break;
1710	case NETDEV_DOWN:
1711		neigh_ifdown(&nd_tbl, dev);
1712		fib6_run_gc(0, net, false);
1713		break;
1714	case NETDEV_NOTIFY_PEERS:
1715		ndisc_send_unsol_na(dev);
1716		break;
1717	default:
1718		break;
1719	}
1720
1721	return NOTIFY_DONE;
1722}
1723
1724static struct notifier_block ndisc_netdev_notifier = {
1725	.notifier_call = ndisc_netdev_event,
 
1726};
1727
1728#ifdef CONFIG_SYSCTL
1729static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1730					 const char *func, const char *dev_name)
1731{
1732	static char warncomm[TASK_COMM_LEN];
1733	static int warned;
1734	if (strcmp(warncomm, current->comm) && warned < 5) {
1735		strcpy(warncomm, current->comm);
1736		pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1737			warncomm, func,
1738			dev_name, ctl->procname,
1739			dev_name, ctl->procname);
1740		warned++;
1741	}
1742}
1743
1744int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
 
1745{
1746	struct net_device *dev = ctl->extra1;
1747	struct inet6_dev *idev;
1748	int ret;
1749
1750	if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1751	    (strcmp(ctl->procname, "base_reachable_time") == 0))
1752		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1753
1754	if (strcmp(ctl->procname, "retrans_time") == 0)
1755		ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1756
1757	else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1758		ret = neigh_proc_dointvec_jiffies(ctl, write,
1759						  buffer, lenp, ppos);
1760
1761	else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1762		 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1763		ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1764						     buffer, lenp, ppos);
1765	else
1766		ret = -1;
1767
1768	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1769		if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1770			idev->nd_parms->reachable_time =
1771					neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1772		idev->tstamp = jiffies;
1773		inet6_ifinfo_notify(RTM_NEWLINK, idev);
1774		in6_dev_put(idev);
1775	}
1776	return ret;
1777}
1778
1779
1780#endif
1781
1782static int __net_init ndisc_net_init(struct net *net)
1783{
1784	struct ipv6_pinfo *np;
1785	struct sock *sk;
1786	int err;
1787
1788	err = inet_ctl_sock_create(&sk, PF_INET6,
1789				   SOCK_RAW, IPPROTO_ICMPV6, net);
1790	if (err < 0) {
1791		ND_PRINTK(0, err,
1792			  "NDISC: Failed to initialize the control socket (err %d)\n",
1793			  err);
1794		return err;
1795	}
1796
1797	net->ipv6.ndisc_sk = sk;
1798
1799	np = inet6_sk(sk);
1800	np->hop_limit = 255;
1801	/* Do not loopback ndisc messages */
1802	np->mc_loop = 0;
1803
1804	return 0;
1805}
1806
1807static void __net_exit ndisc_net_exit(struct net *net)
1808{
1809	inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1810}
1811
1812static struct pernet_operations ndisc_net_ops = {
1813	.init = ndisc_net_init,
1814	.exit = ndisc_net_exit,
1815};
1816
1817int __init ndisc_init(void)
1818{
1819	int err;
1820
1821	err = register_pernet_subsys(&ndisc_net_ops);
1822	if (err)
1823		return err;
1824	/*
1825	 * Initialize the neighbour table
1826	 */
1827	neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1828
1829#ifdef CONFIG_SYSCTL
1830	err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1831				    ndisc_ifinfo_sysctl_change);
1832	if (err)
1833		goto out_unregister_pernet;
1834out:
1835#endif
1836	return err;
1837
1838#ifdef CONFIG_SYSCTL
1839out_unregister_pernet:
1840	unregister_pernet_subsys(&ndisc_net_ops);
1841	goto out;
1842#endif
1843}
1844
1845int __init ndisc_late_init(void)
1846{
1847	return register_netdevice_notifier(&ndisc_netdev_notifier);
1848}
1849
1850void ndisc_late_cleanup(void)
1851{
1852	unregister_netdevice_notifier(&ndisc_netdev_notifier);
1853}
1854
1855void ndisc_cleanup(void)
1856{
1857#ifdef CONFIG_SYSCTL
1858	neigh_sysctl_unregister(&nd_tbl.parms);
1859#endif
1860	neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1861	unregister_pernet_subsys(&ndisc_net_ops);
1862}
v6.13.7
   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_PREFIX_INFO ||
 201		opt->nd_opt_type == ND_OPT_RDNSS ||
 202		opt->nd_opt_type == ND_OPT_DNSSL ||
 203		opt->nd_opt_type == ND_OPT_6CO ||
 204		opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
 205		opt->nd_opt_type == ND_OPT_PREF64;
 206}
 207
 208static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
 209					     struct nd_opt_hdr *cur,
 210					     struct nd_opt_hdr *end)
 211{
 212	if (!cur || !end || cur >= end)
 213		return NULL;
 214	do {
 215		cur = ((void *)cur) + (cur->nd_opt_len << 3);
 216	} while (cur < end && !ndisc_is_useropt(dev, cur));
 217	return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
 218}
 219
 220struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 221					  u8 *opt, int opt_len,
 222					  struct ndisc_options *ndopts)
 223{
 224	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
 225
 226	if (!nd_opt || opt_len < 0 || !ndopts)
 227		return NULL;
 228	memset(ndopts, 0, sizeof(*ndopts));
 229	while (opt_len) {
 230		bool unknown = false;
 231		int l;
 232		if (opt_len < sizeof(struct nd_opt_hdr))
 233			return NULL;
 234		l = nd_opt->nd_opt_len << 3;
 235		if (opt_len < l || l == 0)
 236			return NULL;
 237		if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
 238			goto next_opt;
 239		switch (nd_opt->nd_opt_type) {
 240		case ND_OPT_SOURCE_LL_ADDR:
 241		case ND_OPT_TARGET_LL_ADDR:
 242		case ND_OPT_MTU:
 243		case ND_OPT_NONCE:
 244		case ND_OPT_REDIRECT_HDR:
 245			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
 246				ND_PRINTK(2, warn,
 247					  "%s: duplicated ND6 option found: type=%d\n",
 248					  __func__, nd_opt->nd_opt_type);
 249			} else {
 250				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 251			}
 252			break;
 253		case ND_OPT_PREFIX_INFO:
 254			ndopts->nd_opts_pi_end = nd_opt;
 255			if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
 256				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
 257			break;
 258#ifdef CONFIG_IPV6_ROUTE_INFO
 259		case ND_OPT_ROUTE_INFO:
 260			ndopts->nd_opts_ri_end = nd_opt;
 261			if (!ndopts->nd_opts_ri)
 262				ndopts->nd_opts_ri = nd_opt;
 263			break;
 264#endif
 265		default:
 266			unknown = true;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 267		}
 268		if (ndisc_is_useropt(dev, nd_opt)) {
 269			ndopts->nd_useropts_end = nd_opt;
 270			if (!ndopts->nd_useropts)
 271				ndopts->nd_useropts = nd_opt;
 272		} else if (unknown) {
 273			/*
 274			 * Unknown options must be silently ignored,
 275			 * to accommodate future extension to the
 276			 * protocol.
 277			 */
 278			ND_PRINTK(2, notice,
 279				  "%s: ignored unsupported option; type=%d, len=%d\n",
 280				  __func__,
 281				  nd_opt->nd_opt_type,
 282				  nd_opt->nd_opt_len);
 283		}
 284next_opt:
 285		opt_len -= l;
 286		nd_opt = ((void *)nd_opt) + l;
 287	}
 288	return ndopts;
 289}
 290
 291int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
 292{
 293	switch (dev->type) {
 294	case ARPHRD_ETHER:
 295	case ARPHRD_IEEE802:	/* Not sure. Check it later. --ANK */
 296	case ARPHRD_FDDI:
 297		ipv6_eth_mc_map(addr, buf);
 298		return 0;
 299	case ARPHRD_ARCNET:
 300		ipv6_arcnet_mc_map(addr, buf);
 301		return 0;
 302	case ARPHRD_INFINIBAND:
 303		ipv6_ib_mc_map(addr, dev->broadcast, buf);
 304		return 0;
 305	case ARPHRD_IPGRE:
 306		return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
 307	default:
 308		if (dir) {
 309			memcpy(buf, dev->broadcast, dev->addr_len);
 310			return 0;
 311		}
 312	}
 313	return -EINVAL;
 314}
 315EXPORT_SYMBOL(ndisc_mc_map);
 316
 317static u32 ndisc_hash(const void *pkey,
 318		      const struct net_device *dev,
 319		      __u32 *hash_rnd)
 320{
 321	return ndisc_hashfn(pkey, dev, hash_rnd);
 322}
 323
 324static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
 325{
 326	return neigh_key_eq128(n, pkey);
 327}
 328
 329static int ndisc_constructor(struct neighbour *neigh)
 330{
 331	struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
 332	struct net_device *dev = neigh->dev;
 333	struct inet6_dev *in6_dev;
 334	struct neigh_parms *parms;
 335	bool is_multicast = ipv6_addr_is_multicast(addr);
 336
 337	in6_dev = in6_dev_get(dev);
 338	if (!in6_dev) {
 339		return -EINVAL;
 340	}
 341
 342	parms = in6_dev->nd_parms;
 343	__neigh_parms_put(neigh->parms);
 344	neigh->parms = neigh_parms_clone(parms);
 345
 346	neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
 347	if (!dev->header_ops) {
 348		neigh->nud_state = NUD_NOARP;
 349		neigh->ops = &ndisc_direct_ops;
 350		neigh->output = neigh_direct_output;
 351	} else {
 352		if (is_multicast) {
 353			neigh->nud_state = NUD_NOARP;
 354			ndisc_mc_map(addr, neigh->ha, dev, 1);
 355		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
 356			neigh->nud_state = NUD_NOARP;
 357			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
 358			if (dev->flags&IFF_LOOPBACK)
 359				neigh->type = RTN_LOCAL;
 360		} else if (dev->flags&IFF_POINTOPOINT) {
 361			neigh->nud_state = NUD_NOARP;
 362			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 363		}
 364		if (dev->header_ops->cache)
 365			neigh->ops = &ndisc_hh_ops;
 366		else
 367			neigh->ops = &ndisc_generic_ops;
 368		if (neigh->nud_state&NUD_VALID)
 369			neigh->output = neigh->ops->connected_output;
 370		else
 371			neigh->output = neigh->ops->output;
 372	}
 373	in6_dev_put(in6_dev);
 374	return 0;
 375}
 376
 377static int pndisc_constructor(struct pneigh_entry *n)
 378{
 379	struct in6_addr *addr = (struct in6_addr *)&n->key;
 380	struct in6_addr maddr;
 381	struct net_device *dev = n->dev;
 382
 383	if (!dev || !__in6_dev_get(dev))
 384		return -EINVAL;
 385	addrconf_addr_solict_mult(addr, &maddr);
 386	ipv6_dev_mc_inc(dev, &maddr);
 387	return 0;
 388}
 389
 390static void pndisc_destructor(struct pneigh_entry *n)
 391{
 392	struct in6_addr *addr = (struct in6_addr *)&n->key;
 393	struct in6_addr maddr;
 394	struct net_device *dev = n->dev;
 395
 396	if (!dev || !__in6_dev_get(dev))
 397		return;
 398	addrconf_addr_solict_mult(addr, &maddr);
 399	ipv6_dev_mc_dec(dev, &maddr);
 400}
 401
 402/* called with rtnl held */
 403static bool ndisc_allow_add(const struct net_device *dev,
 404			    struct netlink_ext_ack *extack)
 405{
 406	struct inet6_dev *idev = __in6_dev_get(dev);
 407
 408	if (!idev || idev->cnf.disable_ipv6) {
 409		NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
 410		return false;
 411	}
 412
 413	return true;
 414}
 415
 416static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 417				       int len)
 418{
 419	int hlen = LL_RESERVED_SPACE(dev);
 420	int tlen = dev->needed_tailroom;
 
 421	struct sk_buff *skb;
 422
 423	skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
 424	if (!skb)
 
 
 425		return NULL;
 
 426
 427	skb->protocol = htons(ETH_P_IPV6);
 428	skb->dev = dev;
 429
 430	skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
 431	skb_reset_transport_header(skb);
 432
 433	/* Manually assign socket ownership as we avoid calling
 434	 * sock_alloc_send_pskb() to bypass wmem buffer limits
 435	 */
 436	rcu_read_lock();
 437	skb_set_owner_w(skb, dev_net_rcu(dev)->ipv6.ndisc_sk);
 438	rcu_read_unlock();
 439
 440	return skb;
 441}
 442
 443static void ip6_nd_hdr(struct sk_buff *skb,
 444		       const struct in6_addr *saddr,
 445		       const struct in6_addr *daddr,
 446		       int hop_limit, int len)
 447{
 448	struct ipv6hdr *hdr;
 449	struct inet6_dev *idev;
 450	unsigned tclass;
 451
 452	rcu_read_lock();
 453	idev = __in6_dev_get(skb->dev);
 454	tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0;
 455	rcu_read_unlock();
 456
 457	skb_push(skb, sizeof(*hdr));
 458	skb_reset_network_header(skb);
 459	hdr = ipv6_hdr(skb);
 460
 461	ip6_flow_hdr(hdr, tclass, 0);
 462
 463	hdr->payload_len = htons(len);
 464	hdr->nexthdr = IPPROTO_ICMPV6;
 465	hdr->hop_limit = hop_limit;
 466
 467	hdr->saddr = *saddr;
 468	hdr->daddr = *daddr;
 469}
 470
 471void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
 472		    const struct in6_addr *saddr)
 
 473{
 474	struct icmp6hdr *icmp6h = icmp6_hdr(skb);
 475	struct dst_entry *dst = skb_dst(skb);
 
 
 476	struct inet6_dev *idev;
 477	struct net *net;
 478	struct sock *sk;
 479	int err;
 
 480	u8 type;
 481
 482	type = icmp6h->icmp6_type;
 483
 484	rcu_read_lock();
 485
 486	net = dev_net_rcu(skb->dev);
 487	sk = net->ipv6.ndisc_sk;
 488	if (!dst) {
 489		struct flowi6 fl6;
 490		int oif = skb->dev->ifindex;
 491
 492		icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
 
 
 493		dst = icmp6_dst_alloc(skb->dev, &fl6);
 494		if (IS_ERR(dst)) {
 495			rcu_read_unlock();
 496			kfree_skb(skb);
 497			return;
 498		}
 499
 500		skb_dst_set(skb, dst);
 501	}
 502
 503	icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
 504					      IPPROTO_ICMPV6,
 505					      csum_partial(icmp6h,
 506							   skb->len, 0));
 507
 508	ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len);
 509
 
 510	idev = __in6_dev_get(dst->dev);
 511	IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
 512
 513	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
 514		      net, sk, skb, NULL, dst->dev,
 515		      dst_output);
 516	if (!err) {
 517		ICMP6MSGOUT_INC_STATS(net, idev, type);
 518		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 519	}
 520
 521	rcu_read_unlock();
 522}
 523EXPORT_SYMBOL(ndisc_send_skb);
 524
 525void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 526		   const struct in6_addr *solicited_addr,
 527		   bool router, bool solicited, bool override, bool inc_opt)
 528{
 529	struct sk_buff *skb;
 530	struct in6_addr tmpaddr;
 531	struct inet6_ifaddr *ifp;
 532	const struct in6_addr *src_addr;
 533	struct nd_msg *msg;
 534	int optlen = 0;
 535
 536	/* for anycast or proxy, solicited_addr != src_addr */
 537	ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
 538	if (ifp) {
 539		src_addr = solicited_addr;
 540		if (ifp->flags & IFA_F_OPTIMISTIC)
 541			override = false;
 542		inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao);
 543		in6_ifa_put(ifp);
 544	} else {
 545		if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
 546				       inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
 547				       &tmpaddr))
 548			return;
 549		src_addr = &tmpaddr;
 550	}
 551
 552	if (!dev->addr_len)
 553		inc_opt = false;
 554	if (inc_opt)
 555		optlen += ndisc_opt_addr_space(dev,
 556					       NDISC_NEIGHBOUR_ADVERTISEMENT);
 557
 558	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 559	if (!skb)
 560		return;
 561
 562	msg = skb_put(skb, sizeof(*msg));
 563	*msg = (struct nd_msg) {
 564		.icmph = {
 565			.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
 566			.icmp6_router = router,
 567			.icmp6_solicited = solicited,
 568			.icmp6_override = override,
 569		},
 570		.target = *solicited_addr,
 571	};
 572
 573	if (inc_opt)
 574		ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
 575				       dev->dev_addr,
 576				       NDISC_NEIGHBOUR_ADVERTISEMENT);
 577
 578	ndisc_send_skb(skb, daddr, src_addr);
 579}
 580
 581static void ndisc_send_unsol_na(struct net_device *dev)
 582{
 583	struct inet6_dev *idev;
 584	struct inet6_ifaddr *ifa;
 585
 586	idev = in6_dev_get(dev);
 587	if (!idev)
 588		return;
 589
 590	read_lock_bh(&idev->lock);
 591	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 592		/* skip tentative addresses until dad completes */
 593		if (ifa->flags & IFA_F_TENTATIVE &&
 594		    !(ifa->flags & IFA_F_OPTIMISTIC))
 595			continue;
 596
 597		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
 598			      /*router=*/ !!idev->cnf.forwarding,
 599			      /*solicited=*/ false, /*override=*/ true,
 600			      /*inc_opt=*/ true);
 601	}
 602	read_unlock_bh(&idev->lock);
 603
 604	in6_dev_put(idev);
 605}
 606
 607struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
 608				const struct in6_addr *saddr, u64 nonce)
 609{
 
 
 610	int inc_opt = dev->addr_len;
 611	struct sk_buff *skb;
 612	struct nd_msg *msg;
 613	int optlen = 0;
 614
 615	if (!saddr)
 616		return NULL;
 
 
 
 
 617
 618	if (ipv6_addr_any(saddr))
 619		inc_opt = false;
 620	if (inc_opt)
 621		optlen += ndisc_opt_addr_space(dev,
 622					       NDISC_NEIGHBOUR_SOLICITATION);
 623	if (nonce != 0)
 624		optlen += 8;
 625
 626	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 627	if (!skb)
 628		return NULL;
 629
 630	msg = skb_put(skb, sizeof(*msg));
 631	*msg = (struct nd_msg) {
 632		.icmph = {
 633			.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
 634		},
 635		.target = *solicit,
 636	};
 637
 638	if (inc_opt)
 639		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 640				       dev->dev_addr,
 641				       NDISC_NEIGHBOUR_SOLICITATION);
 642	if (nonce != 0) {
 643		u8 *opt = skb_put(skb, 8);
 644
 645		opt[0] = ND_OPT_NONCE;
 646		opt[1] = 8 >> 3;
 647		memcpy(opt + 2, &nonce, 6);
 648	}
 649
 650	return skb;
 651}
 652EXPORT_SYMBOL(ndisc_ns_create);
 653
 654void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 655		   const struct in6_addr *daddr, const struct in6_addr *saddr,
 656		   u64 nonce)
 657{
 658	struct in6_addr addr_buf;
 659	struct sk_buff *skb;
 660
 661	if (!saddr) {
 662		if (ipv6_get_lladdr(dev, &addr_buf,
 663				    (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
 664			return;
 665		saddr = &addr_buf;
 666	}
 667
 668	skb = ndisc_ns_create(dev, solicit, saddr, nonce);
 669
 670	if (skb)
 671		ndisc_send_skb(skb, daddr, saddr);
 672}
 673
 674void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 675		   const struct in6_addr *daddr)
 676{
 677	struct sk_buff *skb;
 678	struct rs_msg *msg;
 679	int send_sllao = dev->addr_len;
 680	int optlen = 0;
 681
 682#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 683	/*
 684	 * According to section 2.2 of RFC 4429, we must not
 685	 * send router solicitations with a sllao from
 686	 * optimistic addresses, but we may send the solicitation
 687	 * if we don't include the sllao.  So here we check
 688	 * if our address is optimistic, and if so, we
 689	 * suppress the inclusion of the sllao.
 690	 */
 691	if (send_sllao) {
 692		struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
 693							   dev, 1);
 694		if (ifp) {
 695			if (ifp->flags & IFA_F_OPTIMISTIC)  {
 696				send_sllao = 0;
 697			}
 698			in6_ifa_put(ifp);
 699		} else {
 700			send_sllao = 0;
 701		}
 702	}
 703#endif
 704	if (send_sllao)
 705		optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
 706
 707	skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
 708	if (!skb)
 709		return;
 710
 711	msg = skb_put(skb, sizeof(*msg));
 712	*msg = (struct rs_msg) {
 713		.icmph = {
 714			.icmp6_type = NDISC_ROUTER_SOLICITATION,
 715		},
 716	};
 717
 718	if (send_sllao)
 719		ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
 720				       dev->dev_addr,
 721				       NDISC_ROUTER_SOLICITATION);
 722
 723	ndisc_send_skb(skb, daddr, saddr);
 724}
 725
 726
 727static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
 728{
 729	/*
 730	 *	"The sender MUST return an ICMP
 731	 *	 destination unreachable"
 732	 */
 733	dst_link_failure(skb);
 734	kfree_skb(skb);
 735}
 736
 737/* Called with locked neigh: either read or both */
 738
 739static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
 740{
 741	struct in6_addr *saddr = NULL;
 742	struct in6_addr mcaddr;
 743	struct net_device *dev = neigh->dev;
 744	struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
 745	int probes = atomic_read(&neigh->probes);
 746
 747	if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
 748					   dev, false, 1,
 749					   IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
 750		saddr = &ipv6_hdr(skb)->saddr;
 751	probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
 752	if (probes < 0) {
 753		if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) {
 754			ND_PRINTK(1, dbg,
 755				  "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
 756				  __func__, target);
 757		}
 758		ndisc_send_ns(dev, target, target, saddr, 0);
 759	} else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
 760		neigh_app_ns(neigh);
 761	} else {
 762		addrconf_addr_solict_mult(target, &mcaddr);
 763		ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
 764	}
 765}
 766
 767static int pndisc_is_router(const void *pkey,
 768			    struct net_device *dev)
 769{
 770	struct pneigh_entry *n;
 771	int ret = -1;
 772
 773	read_lock_bh(&nd_tbl.lock);
 774	n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
 775	if (n)
 776		ret = !!(n->flags & NTF_ROUTER);
 777	read_unlock_bh(&nd_tbl.lock);
 778
 779	return ret;
 780}
 781
 782void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 783		  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 784		  struct ndisc_options *ndopts)
 785{
 786	neigh_update(neigh, lladdr, new, flags, 0);
 787	/* report ndisc ops about neighbour update */
 788	ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
 789}
 790
 791static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
 792{
 793	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 794	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 795	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 796	u8 *lladdr = NULL;
 797	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
 798				    offsetof(struct nd_msg, opt));
 799	struct ndisc_options ndopts;
 800	struct net_device *dev = skb->dev;
 801	struct inet6_ifaddr *ifp;
 802	struct inet6_dev *idev = NULL;
 803	struct neighbour *neigh;
 804	int dad = ipv6_addr_any(saddr);
 
 805	int is_router = -1;
 806	SKB_DR(reason);
 807	u64 nonce = 0;
 808	bool inc;
 809
 810	if (skb->len < sizeof(struct nd_msg))
 811		return SKB_DROP_REASON_PKT_TOO_SMALL;
 
 
 812
 813	if (ipv6_addr_is_multicast(&msg->target)) {
 814		ND_PRINTK(2, warn, "NS: multicast target address\n");
 815		return reason;
 816	}
 817
 818	/*
 819	 * RFC2461 7.1.1:
 820	 * DAD has to be destined for solicited node multicast address.
 821	 */
 822	if (dad && !ipv6_addr_is_solict_mult(daddr)) {
 823		ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
 824		return reason;
 825	}
 826
 827	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
 828		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
 
 
 829
 830	if (ndopts.nd_opts_src_lladdr) {
 831		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
 832		if (!lladdr) {
 833			ND_PRINTK(2, warn,
 834				  "NS: invalid link-layer address length\n");
 835			return reason;
 836		}
 837
 838		/* RFC2461 7.1.1:
 839		 *	If the IP source address is the unspecified address,
 840		 *	there MUST NOT be source link-layer address option
 841		 *	in the message.
 842		 */
 843		if (dad) {
 844			ND_PRINTK(2, warn,
 845				  "NS: bad DAD packet (link-layer address option)\n");
 846			return reason;
 847		}
 848	}
 849	if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
 850		memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
 851
 852	inc = ipv6_addr_is_multicast(daddr);
 853
 854	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
 855	if (ifp) {
 856have_ifp:
 857		if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
 858			if (dad) {
 859				if (nonce != 0 && ifp->dad_nonce == nonce) {
 860					u8 *np = (u8 *)&nonce;
 861					/* Matching nonce if looped back */
 862					ND_PRINTK(2, notice,
 863						  "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
 864						  ifp->idev->dev->name,
 865						  &ifp->addr, np);
 866					goto out;
 867				}
 868				/*
 869				 * We are colliding with another node
 870				 * who is doing DAD
 871				 * so fail our DAD process
 872				 */
 873				addrconf_dad_failure(skb, ifp);
 874				return reason;
 875			} else {
 876				/*
 877				 * This is not a dad solicitation.
 878				 * If we are an optimistic node,
 879				 * we should respond.
 880				 * Otherwise, we should ignore it.
 881				 */
 882				if (!(ifp->flags & IFA_F_OPTIMISTIC))
 883					goto out;
 884			}
 885		}
 886
 887		idev = ifp->idev;
 888	} else {
 889		struct net *net = dev_net(dev);
 890
 891		/* perhaps an address on the master device */
 892		if (netif_is_l3_slave(dev)) {
 893			struct net_device *mdev;
 894
 895			mdev = netdev_master_upper_dev_get_rcu(dev);
 896			if (mdev) {
 897				ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
 898				if (ifp)
 899					goto have_ifp;
 900			}
 901		}
 902
 903		idev = in6_dev_get(dev);
 904		if (!idev) {
 905			/* XXX: count this drop? */
 906			return reason;
 907		}
 908
 909		if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 910		    (READ_ONCE(idev->cnf.forwarding) &&
 911		     (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) ||
 912		      READ_ONCE(idev->cnf.proxy_ndp)) &&
 913		     (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 914			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 915			    skb->pkt_type != PACKET_HOST &&
 916			    inc &&
 917			    NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
 918				/*
 919				 * for anycast or proxy,
 920				 * sender should delay its response
 921				 * by a random time between 0 and
 922				 * MAX_ANYCAST_DELAY_TIME seconds.
 923				 * (RFC2461) -- yoshfuji
 924				 */
 925				struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
 926				if (n)
 927					pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
 928				goto out;
 929			}
 930		} else {
 931			SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST);
 932			goto out;
 933		}
 934	}
 935
 936	if (is_router < 0)
 937		is_router = READ_ONCE(idev->cnf.forwarding);
 938
 939	if (dad) {
 940		ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
 941			      !!is_router, false, (ifp != NULL), true);
 942		goto out;
 943	}
 944
 945	if (inc)
 946		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
 947	else
 948		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
 949
 950	/*
 951	 *	update / create cache entry
 952	 *	for the source address
 953	 */
 954	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
 955			       !inc || lladdr || !dev->addr_len);
 956	if (neigh)
 957		ndisc_update(dev, neigh, lladdr, NUD_STALE,
 958			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
 959			     NEIGH_UPDATE_F_OVERRIDE,
 960			     NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
 961	if (neigh || !dev->header_ops) {
 962		ndisc_send_na(dev, saddr, &msg->target, !!is_router,
 963			      true, (ifp != NULL && inc), inc);
 964		if (neigh)
 965			neigh_release(neigh);
 966		reason = SKB_CONSUMED;
 967	}
 968
 969out:
 970	if (ifp)
 971		in6_ifa_put(ifp);
 972	else
 973		in6_dev_put(idev);
 974	return reason;
 975}
 976
 977static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
 978{
 979	struct inet6_dev *idev = __in6_dev_get(dev);
 980
 981	switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
 982	case 0: /* Don't accept untracked na (absent in neighbor cache) */
 983		return 0;
 984	case 1: /* Create new entries from na if currently untracked */
 985		return 1;
 986	case 2: /* Create new entries from untracked na only if saddr is in the
 987		 * same subnet as an address configured on the interface that
 988		 * received the na
 989		 */
 990		return !!ipv6_chk_prefix(saddr, dev);
 991	default:
 992		return 0;
 993	}
 994}
 995
 996static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
 997{
 998	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
 999	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1000	const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
1001	u8 *lladdr = NULL;
1002	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1003				    offsetof(struct nd_msg, opt));
1004	struct ndisc_options ndopts;
1005	struct net_device *dev = skb->dev;
1006	struct inet6_dev *idev = __in6_dev_get(dev);
1007	struct inet6_ifaddr *ifp;
1008	struct neighbour *neigh;
1009	SKB_DR(reason);
1010	u8 new_state;
1011
1012	if (skb->len < sizeof(struct nd_msg))
1013		return SKB_DROP_REASON_PKT_TOO_SMALL;
 
 
1014
1015	if (ipv6_addr_is_multicast(&msg->target)) {
1016		ND_PRINTK(2, warn, "NA: target address is multicast\n");
1017		return reason;
1018	}
1019
1020	if (ipv6_addr_is_multicast(daddr) &&
1021	    msg->icmph.icmp6_solicited) {
1022		ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
1023		return reason;
1024	}
1025
1026	/* For some 802.11 wireless deployments (and possibly other networks),
1027	 * there will be a NA proxy and unsolicitd packets are attacks
1028	 * and thus should not be accepted.
1029	 * drop_unsolicited_na takes precedence over accept_untracked_na
1030	 */
1031	if (!msg->icmph.icmp6_solicited && idev &&
1032	    READ_ONCE(idev->cnf.drop_unsolicited_na))
1033		return reason;
1034
1035	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
1036		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1037
 
 
 
 
1038	if (ndopts.nd_opts_tgt_lladdr) {
1039		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1040		if (!lladdr) {
1041			ND_PRINTK(2, warn,
1042				  "NA: invalid link-layer address length\n");
1043			return reason;
1044		}
1045	}
1046	ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1047	if (ifp) {
1048		if (skb->pkt_type != PACKET_LOOPBACK
1049		    && (ifp->flags & IFA_F_TENTATIVE)) {
1050				addrconf_dad_failure(skb, ifp);
1051				return reason;
1052		}
1053		/* What should we make now? The advertisement
1054		   is invalid, but ndisc specs say nothing
1055		   about it. It could be misconfiguration, or
1056		   an smart proxy agent tries to help us :-)
1057
1058		   We should not print the error if NA has been
1059		   received from loopback - it is just our own
1060		   unsolicited advertisement.
1061		 */
1062		if (skb->pkt_type != PACKET_LOOPBACK)
1063			ND_PRINTK(1, warn,
1064				  "NA: %pM advertised our address %pI6c on %s!\n",
1065				  eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1066		in6_ifa_put(ifp);
1067		return reason;
1068	}
1069
1070	neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1071
1072	/* RFC 9131 updates original Neighbour Discovery RFC 4861.
1073	 * NAs with Target LL Address option without a corresponding
1074	 * entry in the neighbour cache can now create a STALE neighbour
1075	 * cache entry on routers.
1076	 *
1077	 *   entry accept  fwding  solicited        behaviour
1078	 * ------- ------  ------  ---------    ----------------------
1079	 * present      X       X         0     Set state to STALE
1080	 * present      X       X         1     Set state to REACHABLE
1081	 *  absent      0       X         X     Do nothing
1082	 *  absent      1       0         X     Do nothing
1083	 *  absent      1       1         X     Add a new STALE entry
1084	 *
1085	 * Note that we don't do a (daddr == all-routers-mcast) check.
1086	 */
1087	new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1088	if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) {
1089		if (accept_untracked_na(dev, saddr)) {
1090			neigh = neigh_create(&nd_tbl, &msg->target, dev);
1091			new_state = NUD_STALE;
1092		}
1093	}
1094
1095	if (neigh && !IS_ERR(neigh)) {
1096		u8 old_flags = neigh->flags;
1097		struct net *net = dev_net(dev);
1098
1099		if (READ_ONCE(neigh->nud_state) & NUD_FAILED)
1100			goto out;
1101
1102		/*
1103		 * Don't update the neighbor cache entry on a proxy NA from
1104		 * ourselves because either the proxied node is off link or it
1105		 * has already sent a NA to us.
1106		 */
1107		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1108		    READ_ONCE(net->ipv6.devconf_all->forwarding) &&
1109		    READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
1110		    pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1111			/* XXX: idev->cnf.proxy_ndp */
1112			goto out;
1113		}
1114
1115		ndisc_update(dev, neigh, lladdr,
1116			     new_state,
1117			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1118			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1119			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1120			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1121			     NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1122
1123		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1124			/*
1125			 * Change: router to host
1126			 */
1127			rt6_clean_tohost(dev_net(dev),  saddr);
1128		}
1129		reason = SKB_CONSUMED;
1130out:
1131		neigh_release(neigh);
1132	}
1133	return reason;
1134}
1135
1136static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
1137{
1138	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1139	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1140	struct neighbour *neigh;
1141	struct inet6_dev *idev;
1142	const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1143	struct ndisc_options ndopts;
1144	u8 *lladdr = NULL;
1145	SKB_DR(reason);
1146
1147	if (skb->len < sizeof(*rs_msg))
1148		return SKB_DROP_REASON_PKT_TOO_SMALL;
1149
1150	idev = __in6_dev_get(skb->dev);
1151	if (!idev) {
1152		ND_PRINTK(1, err, "RS: can't find in6 device\n");
1153		return reason;
1154	}
1155
1156	/* Don't accept RS if we're not in router mode */
1157	if (!READ_ONCE(idev->cnf.forwarding))
1158		goto out;
1159
1160	/*
1161	 * Don't update NCE if src = ::;
1162	 * this implies that the source node has no ip address assigned yet.
1163	 */
1164	if (ipv6_addr_any(saddr))
1165		goto out;
1166
1167	/* Parse ND options */
1168	if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts))
1169		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
 
 
1170
1171	if (ndopts.nd_opts_src_lladdr) {
1172		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1173					     skb->dev);
1174		if (!lladdr)
1175			goto out;
1176	}
1177
1178	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1179	if (neigh) {
1180		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1181			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1182			     NEIGH_UPDATE_F_OVERRIDE|
1183			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1184			     NDISC_ROUTER_SOLICITATION, &ndopts);
1185		neigh_release(neigh);
1186		reason = SKB_CONSUMED;
1187	}
1188out:
1189	return reason;
1190}
1191
1192static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1193{
1194	struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1195	struct sk_buff *skb;
1196	struct nlmsghdr *nlh;
1197	struct nduseroptmsg *ndmsg;
1198	struct net *net = dev_net(ra->dev);
1199	int err;
1200	int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1201				    + (opt->nd_opt_len << 3));
1202	size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1203
1204	skb = nlmsg_new(msg_size, GFP_ATOMIC);
1205	if (!skb) {
1206		err = -ENOBUFS;
1207		goto errout;
1208	}
1209
1210	nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1211	if (!nlh) {
1212		goto nla_put_failure;
1213	}
1214
1215	ndmsg = nlmsg_data(nlh);
1216	ndmsg->nduseropt_family = AF_INET6;
1217	ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1218	ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1219	ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1220	ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1221
1222	memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1223
1224	if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1225		goto nla_put_failure;
1226	nlmsg_end(skb, nlh);
1227
1228	rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1229	return;
1230
1231nla_put_failure:
1232	nlmsg_free(skb);
1233	err = -EMSGSIZE;
1234errout:
1235	rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1236}
1237
1238static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
1239{
1240	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1241	bool send_ifinfo_notify = false;
1242	struct neighbour *neigh = NULL;
 
 
 
1243	struct ndisc_options ndopts;
1244	struct fib6_info *rt = NULL;
1245	struct inet6_dev *in6_dev;
1246	struct fib6_table *table;
1247	u32 defrtr_usr_metric;
1248	unsigned int pref = 0;
1249	__u32 old_if_flags;
1250	struct net *net;
1251	SKB_DR(reason);
1252	int lifetime;
1253	int optlen;
1254
1255	__u8 *opt = (__u8 *)(ra_msg + 1);
1256
1257	optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1258		sizeof(struct ra_msg);
1259
1260	ND_PRINTK(2, info,
1261		  "RA: %s, dev: %s\n",
1262		  __func__, skb->dev->name);
1263	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1264		ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1265		return reason;
 
 
 
 
1266	}
1267	if (optlen < 0)
1268		return SKB_DROP_REASON_PKT_TOO_SMALL;
1269
1270#ifdef CONFIG_IPV6_NDISC_NODETYPE
1271	if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1272		ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1273		return reason;
1274	}
1275#endif
1276
 
 
 
 
1277	in6_dev = __in6_dev_get(skb->dev);
1278	if (!in6_dev) {
1279		ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1280			  skb->dev->name);
1281		return reason;
1282	}
1283
1284	if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
1285		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
 
 
1286
1287	if (!ipv6_accept_ra(in6_dev)) {
1288		ND_PRINTK(2, info,
1289			  "RA: %s, did not accept ra for dev: %s\n",
1290			  __func__, skb->dev->name);
1291		goto skip_linkparms;
1292	}
1293
1294#ifdef CONFIG_IPV6_NDISC_NODETYPE
1295	/* skip link-specific parameters from interior routers */
1296	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1297		ND_PRINTK(2, info,
1298			  "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1299			  __func__, skb->dev->name);
1300		goto skip_linkparms;
1301	}
1302#endif
1303
1304	if (in6_dev->if_flags & IF_RS_SENT) {
1305		/*
1306		 *	flag that an RA was received after an RS was sent
1307		 *	out on this interface.
1308		 */
1309		in6_dev->if_flags |= IF_RA_RCVD;
1310	}
1311
1312	/*
1313	 * Remember the managed/otherconf flags from most recently
1314	 * received RA message (RFC 2462) -- yoshfuji
1315	 */
1316	old_if_flags = in6_dev->if_flags;
1317	in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1318				IF_RA_OTHERCONF)) |
1319				(ra_msg->icmph.icmp6_addrconf_managed ?
1320					IF_RA_MANAGED : 0) |
1321				(ra_msg->icmph.icmp6_addrconf_other ?
1322					IF_RA_OTHERCONF : 0);
1323
1324	if (old_if_flags != in6_dev->if_flags)
1325		send_ifinfo_notify = true;
1326
1327	if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) {
1328		ND_PRINTK(2, info,
1329			  "RA: %s, defrtr is false for dev: %s\n",
1330			  __func__, skb->dev->name);
1331		goto skip_defrtr;
1332	}
1333
1334	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1335	if (lifetime != 0 &&
1336	    lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) {
1337		ND_PRINTK(2, info,
1338			  "RA: router lifetime (%ds) is too short: %s\n",
1339			  lifetime, skb->dev->name);
1340		goto skip_defrtr;
1341	}
1342
1343	/* Do not accept RA with source-addr found on local machine unless
1344	 * accept_ra_from_local is set to true.
1345	 */
1346	net = dev_net(in6_dev->dev);
1347	if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1348	    ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1349		ND_PRINTK(2, info,
1350			  "RA from local address detected on dev: %s: default router ignored\n",
1351			  skb->dev->name);
1352		goto skip_defrtr;
1353	}
1354
 
 
1355#ifdef CONFIG_IPV6_ROUTER_PREF
1356	pref = ra_msg->icmph.icmp6_router_pref;
1357	/* 10b is handled as if it were 00b (medium) */
1358	if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1359	    !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref))
1360		pref = ICMPV6_ROUTER_PREF_MEDIUM;
1361#endif
1362	/* routes added from RAs do not use nexthop objects */
1363	rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
 
1364	if (rt) {
1365		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1366					 rt->fib6_nh->fib_nh_dev, NULL,
1367					  &ipv6_hdr(skb)->saddr);
1368		if (!neigh) {
1369			ND_PRINTK(0, err,
1370				  "RA: %s got default router without neighbour\n",
1371				  __func__);
1372			fib6_info_release(rt);
1373			return reason;
1374		}
1375	}
1376	/* Set default route metric as specified by user */
1377	defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1378	/* delete the route if lifetime is 0 or if metric needs change */
1379	if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1380		ip6_del_rt(net, rt, false);
1381		rt = NULL;
1382	}
1383
1384	ND_PRINTK(3, info, "RA: rt: %p  lifetime: %d, metric: %d, for dev: %s\n",
1385		  rt, lifetime, defrtr_usr_metric, skb->dev->name);
1386	if (!rt && lifetime) {
1387		ND_PRINTK(3, info, "RA: adding default router\n");
1388
1389		if (neigh)
1390			neigh_release(neigh);
1391
1392		rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1393					 skb->dev, pref, defrtr_usr_metric,
1394					 lifetime);
1395		if (!rt) {
1396			ND_PRINTK(0, err,
1397				  "RA: %s failed to add default route\n",
1398				  __func__);
1399			return reason;
1400		}
1401
1402		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1403					 rt->fib6_nh->fib_nh_dev, NULL,
1404					  &ipv6_hdr(skb)->saddr);
1405		if (!neigh) {
1406			ND_PRINTK(0, err,
1407				  "RA: %s got default router without neighbour\n",
1408				  __func__);
1409			fib6_info_release(rt);
1410			return reason;
1411		}
1412		neigh->flags |= NTF_ROUTER;
1413	} else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1414		struct nl_info nlinfo = {
1415			.nl_net = net,
1416		};
1417		rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1418		inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
1419	}
1420
1421	if (rt) {
1422		table = rt->fib6_table;
1423		spin_lock_bh(&table->tb6_lock);
1424
1425		fib6_set_expires(rt, jiffies + (HZ * lifetime));
1426		fib6_add_gc_list(rt);
1427
1428		spin_unlock_bh(&table->tb6_lock);
1429	}
1430	if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 &&
1431	    ra_msg->icmph.icmp6_hop_limit) {
1432		if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <=
1433		    ra_msg->icmph.icmp6_hop_limit) {
1434			WRITE_ONCE(in6_dev->cnf.hop_limit,
1435				   ra_msg->icmph.icmp6_hop_limit);
1436			fib6_metric_set(rt, RTAX_HOPLIMIT,
1437					ra_msg->icmph.icmp6_hop_limit);
1438		} else {
1439			ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1440		}
1441	}
1442
1443skip_defrtr:
1444
1445	/*
1446	 *	Update Reachable Time and Retrans Timer
1447	 */
1448
1449	if (in6_dev->nd_parms) {
1450		unsigned long rtime = ntohl(ra_msg->retrans_timer);
1451
1452		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1453			rtime = (rtime*HZ)/1000;
1454			if (rtime < HZ/100)
1455				rtime = HZ/100;
1456			NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1457			in6_dev->tstamp = jiffies;
1458			send_ifinfo_notify = true;
1459		}
1460
1461		rtime = ntohl(ra_msg->reachable_time);
1462		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1463			rtime = (rtime*HZ)/1000;
1464
1465			if (rtime < HZ/10)
1466				rtime = HZ/10;
1467
1468			if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1469				NEIGH_VAR_SET(in6_dev->nd_parms,
1470					      BASE_REACHABLE_TIME, rtime);
1471				NEIGH_VAR_SET(in6_dev->nd_parms,
1472					      GC_STALETIME, 3 * rtime);
1473				in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1474				in6_dev->tstamp = jiffies;
1475				send_ifinfo_notify = true;
1476			}
1477		}
1478	}
1479
 
 
 
 
 
 
1480skip_linkparms:
1481
1482	/*
1483	 *	Process options.
1484	 */
1485
1486	if (!neigh)
1487		neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1488				       skb->dev, 1);
1489	if (neigh) {
1490		u8 *lladdr = NULL;
1491		if (ndopts.nd_opts_src_lladdr) {
1492			lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1493						     skb->dev);
1494			if (!lladdr) {
1495				ND_PRINTK(2, warn,
1496					  "RA: invalid link-layer address length\n");
1497				goto out;
1498			}
1499		}
1500		ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1501			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1502			     NEIGH_UPDATE_F_OVERRIDE|
1503			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1504			     NEIGH_UPDATE_F_ISROUTER,
1505			     NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1506		reason = SKB_CONSUMED;
1507	}
1508
1509	if (!ipv6_accept_ra(in6_dev)) {
1510		ND_PRINTK(2, info,
1511			  "RA: %s, accept_ra is false for dev: %s\n",
1512			  __func__, skb->dev->name);
1513		goto out;
1514	}
1515
1516#ifdef CONFIG_IPV6_ROUTE_INFO
1517	if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1518	    ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1519			  in6_dev->dev, 0)) {
1520		ND_PRINTK(2, info,
1521			  "RA from local address detected on dev: %s: router info ignored.\n",
1522			  skb->dev->name);
1523		goto skip_routeinfo;
1524	}
1525
1526	if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) {
1527		struct nd_opt_hdr *p;
1528		for (p = ndopts.nd_opts_ri;
1529		     p;
1530		     p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1531			struct route_info *ri = (struct route_info *)p;
1532#ifdef CONFIG_IPV6_NDISC_NODETYPE
1533			if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1534			    ri->prefix_len == 0)
1535				continue;
1536#endif
1537			if (ri->prefix_len == 0 &&
1538			    !READ_ONCE(in6_dev->cnf.accept_ra_defrtr))
1539				continue;
1540			if (ri->lifetime != 0 &&
1541			    ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft))
1542				continue;
1543			if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen))
1544				continue;
1545			if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen))
1546				continue;
1547			rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1548				      &ipv6_hdr(skb)->saddr);
1549		}
1550	}
1551
1552skip_routeinfo:
1553#endif
1554
1555#ifdef CONFIG_IPV6_NDISC_NODETYPE
1556	/* skip link-specific ndopts from interior routers */
1557	if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1558		ND_PRINTK(2, info,
1559			  "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1560			  __func__, skb->dev->name);
1561		goto out;
1562	}
1563#endif
1564
1565	if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) {
1566		struct nd_opt_hdr *p;
1567		for (p = ndopts.nd_opts_pi;
1568		     p;
1569		     p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1570			addrconf_prefix_rcv(skb->dev, (u8 *)p,
1571					    (p->nd_opt_len) << 3,
1572					    ndopts.nd_opts_src_lladdr != NULL);
1573		}
1574	}
1575
1576	if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) {
1577		__be32 n;
1578		u32 mtu;
1579
1580		memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1581		mtu = ntohl(n);
1582
1583		if (in6_dev->ra_mtu != mtu) {
1584			in6_dev->ra_mtu = mtu;
1585			send_ifinfo_notify = true;
1586		}
1587
1588		if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1589			ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1590		} else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) {
1591			WRITE_ONCE(in6_dev->cnf.mtu6, mtu);
1592			fib6_metric_set(rt, RTAX_MTU, mtu);
 
 
 
1593			rt6_mtu_change(skb->dev, mtu);
1594		}
1595	}
1596
1597	if (ndopts.nd_useropts) {
1598		struct nd_opt_hdr *p;
1599		for (p = ndopts.nd_useropts;
1600		     p;
1601		     p = ndisc_next_useropt(skb->dev, p,
1602					    ndopts.nd_useropts_end)) {
1603			ndisc_ra_useropt(skb, p);
1604		}
1605	}
1606
1607	if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1608		ND_PRINTK(2, warn, "RA: invalid RA options\n");
1609	}
1610out:
1611	/* Send a notify if RA changed managed/otherconf flags or
1612	 * timer settings or ra_mtu value
1613	 */
1614	if (send_ifinfo_notify)
1615		inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1616
1617	fib6_info_release(rt);
1618	if (neigh)
1619		neigh_release(neigh);
1620	return reason;
1621}
1622
1623static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
1624{
 
 
1625	struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1626	u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1627				    offsetof(struct rd_msg, opt));
1628	struct ndisc_options ndopts;
1629	SKB_DR(reason);
1630	u8 *hdr;
1631
1632#ifdef CONFIG_IPV6_NDISC_NODETYPE
1633	switch (skb->ndisc_nodetype) {
1634	case NDISC_NODETYPE_HOST:
1635	case NDISC_NODETYPE_NODEFAULT:
1636		ND_PRINTK(2, warn,
1637			  "Redirect: from host or unauthorized router\n");
1638		return reason;
1639	}
1640#endif
1641
1642	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1643		ND_PRINTK(2, warn,
1644			  "Redirect: source address is not link-local\n");
1645		return reason;
1646	}
1647
1648	if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1649		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1650
1651	if (!ndopts.nd_opts_rh) {
1652		ip6_redirect_no_header(skb, dev_net(skb->dev),
1653					skb->dev->ifindex);
1654		return reason;
1655	}
1656
1657	hdr = (u8 *)ndopts.nd_opts_rh;
1658	hdr += 8;
1659	if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1660		return SKB_DROP_REASON_PKT_TOO_SMALL;
1661
1662	return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1663}
1664
1665static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1666					   struct sk_buff *orig_skb,
1667					   int rd_len)
1668{
1669	u8 *opt = skb_put(skb, rd_len);
1670
1671	memset(opt, 0, 8);
1672	*(opt++) = ND_OPT_REDIRECT_HDR;
1673	*(opt++) = (rd_len >> 3);
1674	opt += 6;
1675
1676	skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1677		      rd_len - 8);
1678}
1679
1680void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1681{
1682	struct net_device *dev = skb->dev;
1683	struct net *net = dev_net(dev);
1684	struct sock *sk = net->ipv6.ndisc_sk;
1685	int optlen = 0;
1686	struct inet_peer *peer;
1687	struct sk_buff *buff;
1688	struct rd_msg *msg;
1689	struct in6_addr saddr_buf;
1690	struct rt6_info *rt;
1691	struct dst_entry *dst;
1692	struct flowi6 fl6;
1693	int rd_len;
1694	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1695	   ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1696	bool ret;
1697
1698	if (netif_is_l3_master(skb->dev)) {
1699		dev = dev_get_by_index_rcu(dev_net(skb->dev), IPCB(skb)->iif);
1700		if (!dev)
1701			return;
1702	}
1703
1704	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1705		ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1706			  dev->name);
1707		return;
1708	}
1709
1710	if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1711	    ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1712		ND_PRINTK(2, warn,
1713			  "Redirect: target address is not link-local unicast\n");
1714		return;
1715	}
1716
1717	icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1718			 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
 
 
 
1719
1720	dst = ip6_route_output(net, NULL, &fl6);
1721	if (dst->error) {
1722		dst_release(dst);
1723		return;
1724	}
1725	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1726	if (IS_ERR(dst))
1727		return;
1728
1729	rt = dst_rt6_info(dst);
1730
1731	if (rt->rt6i_flags & RTF_GATEWAY) {
1732		ND_PRINTK(2, warn,
1733			  "Redirect: destination is not a neighbour\n");
1734		goto release;
1735	}
1736
1737	rcu_read_lock();
1738	peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr);
1739	ret = inet_peer_xrlim_allow(peer, 1*HZ);
1740	rcu_read_unlock();
1741
1742	if (!ret)
1743		goto release;
1744
1745	if (dev->addr_len) {
1746		struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1747		if (!neigh) {
1748			ND_PRINTK(2, warn,
1749				  "Redirect: no neigh for target address\n");
1750			goto release;
1751		}
1752
1753		read_lock_bh(&neigh->lock);
1754		if (neigh->nud_state & NUD_VALID) {
1755			memcpy(ha_buf, neigh->ha, dev->addr_len);
1756			read_unlock_bh(&neigh->lock);
1757			ha = ha_buf;
1758			optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1759								ops_data_buf,
1760								&ops_data);
1761		} else
1762			read_unlock_bh(&neigh->lock);
1763
1764		neigh_release(neigh);
1765	}
1766
1767	rd_len = min_t(unsigned int,
1768		       IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1769		       skb->len + 8);
1770	rd_len &= ~0x7;
1771	optlen += rd_len;
1772
1773	buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1774	if (!buff)
1775		goto release;
1776
1777	msg = skb_put(buff, sizeof(*msg));
1778	*msg = (struct rd_msg) {
1779		.icmph = {
1780			.icmp6_type = NDISC_REDIRECT,
1781		},
1782		.target = *target,
1783		.dest = ipv6_hdr(skb)->daddr,
1784	};
1785
1786	/*
1787	 *	include target_address option
1788	 */
1789
1790	if (ha)
1791		ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1792
1793	/*
1794	 *	build redirect option and copy skb over to the new packet.
1795	 */
1796
1797	if (rd_len)
1798		ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1799
1800	skb_dst_set(buff, dst);
1801	ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1802	return;
1803
1804release:
1805	dst_release(dst);
1806}
1807
1808static void pndisc_redo(struct sk_buff *skb)
1809{
1810	enum skb_drop_reason reason = ndisc_recv_ns(skb);
1811
1812	kfree_skb_reason(skb, reason);
1813}
1814
1815static int ndisc_is_multicast(const void *pkey)
1816{
1817	return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1818}
1819
1820static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1821{
1822	struct inet6_dev *idev = __in6_dev_get(skb->dev);
1823
1824	if (!idev)
1825		return true;
1826	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1827	    READ_ONCE(idev->cnf.suppress_frag_ndisc)) {
1828		net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1829		return true;
1830	}
1831	return false;
1832}
1833
1834enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
1835{
1836	struct nd_msg *msg;
1837	SKB_DR(reason);
1838
1839	if (ndisc_suppress_frag_ndisc(skb))
1840		return SKB_DROP_REASON_IPV6_NDISC_FRAG;
1841
1842	if (skb_linearize(skb))
1843		return SKB_DROP_REASON_NOMEM;
1844
1845	msg = (struct nd_msg *)skb_transport_header(skb);
1846
1847	__skb_push(skb, skb->data - skb_transport_header(skb));
1848
1849	if (ipv6_hdr(skb)->hop_limit != 255) {
1850		ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1851			  ipv6_hdr(skb)->hop_limit);
1852		return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT;
1853	}
1854
1855	if (msg->icmph.icmp6_code != 0) {
1856		ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1857			  msg->icmph.icmp6_code);
1858		return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE;
1859	}
1860
 
 
1861	switch (msg->icmph.icmp6_type) {
1862	case NDISC_NEIGHBOUR_SOLICITATION:
1863		memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1864		reason = ndisc_recv_ns(skb);
1865		break;
1866
1867	case NDISC_NEIGHBOUR_ADVERTISEMENT:
1868		reason = ndisc_recv_na(skb);
1869		break;
1870
1871	case NDISC_ROUTER_SOLICITATION:
1872		reason = ndisc_recv_rs(skb);
1873		break;
1874
1875	case NDISC_ROUTER_ADVERTISEMENT:
1876		reason = ndisc_router_discovery(skb);
1877		break;
1878
1879	case NDISC_REDIRECT:
1880		reason = ndisc_redirect_rcv(skb);
1881		break;
1882	}
1883
1884	return reason;
1885}
1886
1887static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1888{
1889	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1890	struct netdev_notifier_change_info *change_info;
1891	struct net *net = dev_net(dev);
1892	struct inet6_dev *idev;
1893	bool evict_nocarrier;
1894
1895	switch (event) {
1896	case NETDEV_CHANGEADDR:
1897		neigh_changeaddr(&nd_tbl, dev);
1898		fib6_run_gc(0, net, false);
1899		fallthrough;
1900	case NETDEV_UP:
1901		idev = in6_dev_get(dev);
1902		if (!idev)
1903			break;
1904		if (READ_ONCE(idev->cnf.ndisc_notify) ||
1905		    READ_ONCE(net->ipv6.devconf_all->ndisc_notify))
1906			ndisc_send_unsol_na(dev);
1907		in6_dev_put(idev);
1908		break;
1909	case NETDEV_CHANGE:
1910		idev = in6_dev_get(dev);
1911		if (!idev)
1912			evict_nocarrier = true;
1913		else {
1914			evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) &&
1915					  READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier);
1916			in6_dev_put(idev);
1917		}
1918
1919		change_info = ptr;
1920		if (change_info->flags_changed & IFF_NOARP)
1921			neigh_changeaddr(&nd_tbl, dev);
1922		if (evict_nocarrier && !netif_carrier_ok(dev))
1923			neigh_carrier_down(&nd_tbl, dev);
1924		break;
1925	case NETDEV_DOWN:
1926		neigh_ifdown(&nd_tbl, dev);
1927		fib6_run_gc(0, net, false);
1928		break;
1929	case NETDEV_NOTIFY_PEERS:
1930		ndisc_send_unsol_na(dev);
1931		break;
1932	default:
1933		break;
1934	}
1935
1936	return NOTIFY_DONE;
1937}
1938
1939static struct notifier_block ndisc_netdev_notifier = {
1940	.notifier_call = ndisc_netdev_event,
1941	.priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1942};
1943
1944#ifdef CONFIG_SYSCTL
1945static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl,
1946					 const char *func, const char *dev_name)
1947{
1948	static char warncomm[TASK_COMM_LEN];
1949	static int warned;
1950	if (strcmp(warncomm, current->comm) && warned < 5) {
1951		strscpy(warncomm, current->comm);
1952		pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1953			warncomm, func,
1954			dev_name, ctl->procname,
1955			dev_name, ctl->procname);
1956		warned++;
1957	}
1958}
1959
1960int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer,
1961		size_t *lenp, loff_t *ppos)
1962{
1963	struct net_device *dev = ctl->extra1;
1964	struct inet6_dev *idev;
1965	int ret;
1966
1967	if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1968	    (strcmp(ctl->procname, "base_reachable_time") == 0))
1969		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1970
1971	if (strcmp(ctl->procname, "retrans_time") == 0)
1972		ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1973
1974	else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1975		ret = neigh_proc_dointvec_jiffies(ctl, write,
1976						  buffer, lenp, ppos);
1977
1978	else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1979		 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1980		ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1981						     buffer, lenp, ppos);
1982	else
1983		ret = -1;
1984
1985	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1986		if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1987			idev->nd_parms->reachable_time =
1988					neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1989		WRITE_ONCE(idev->tstamp, jiffies);
1990		inet6_ifinfo_notify(RTM_NEWLINK, idev);
1991		in6_dev_put(idev);
1992	}
1993	return ret;
1994}
1995
1996
1997#endif
1998
1999static int __net_init ndisc_net_init(struct net *net)
2000{
2001	struct ipv6_pinfo *np;
2002	struct sock *sk;
2003	int err;
2004
2005	err = inet_ctl_sock_create(&sk, PF_INET6,
2006				   SOCK_RAW, IPPROTO_ICMPV6, net);
2007	if (err < 0) {
2008		ND_PRINTK(0, err,
2009			  "NDISC: Failed to initialize the control socket (err %d)\n",
2010			  err);
2011		return err;
2012	}
2013
2014	net->ipv6.ndisc_sk = sk;
2015
2016	np = inet6_sk(sk);
2017	np->hop_limit = 255;
2018	/* Do not loopback ndisc messages */
2019	inet6_clear_bit(MC6_LOOP, sk);
2020
2021	return 0;
2022}
2023
2024static void __net_exit ndisc_net_exit(struct net *net)
2025{
2026	inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
2027}
2028
2029static struct pernet_operations ndisc_net_ops = {
2030	.init = ndisc_net_init,
2031	.exit = ndisc_net_exit,
2032};
2033
2034int __init ndisc_init(void)
2035{
2036	int err;
2037
2038	err = register_pernet_subsys(&ndisc_net_ops);
2039	if (err)
2040		return err;
2041	/*
2042	 * Initialize the neighbour table
2043	 */
2044	neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
2045
2046#ifdef CONFIG_SYSCTL
2047	err = neigh_sysctl_register(NULL, &nd_tbl.parms,
2048				    ndisc_ifinfo_sysctl_change);
2049	if (err)
2050		goto out_unregister_pernet;
2051out:
2052#endif
2053	return err;
2054
2055#ifdef CONFIG_SYSCTL
2056out_unregister_pernet:
2057	unregister_pernet_subsys(&ndisc_net_ops);
2058	goto out;
2059#endif
2060}
2061
2062int __init ndisc_late_init(void)
2063{
2064	return register_netdevice_notifier(&ndisc_netdev_notifier);
2065}
2066
2067void ndisc_late_cleanup(void)
2068{
2069	unregister_netdevice_notifier(&ndisc_netdev_notifier);
2070}
2071
2072void ndisc_cleanup(void)
2073{
2074#ifdef CONFIG_SYSCTL
2075	neigh_sysctl_unregister(&nd_tbl.parms);
2076#endif
2077	neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
2078	unregister_pernet_subsys(&ndisc_net_ops);
2079}