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