ndisc.c 41.5 KB
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/*
 *	Neighbour Discovery for IPv6
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 *	Linux INET6 implementation
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 *
 *	Authors:
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 *	Pedro Roque		<roque@di.fc.ul.pt>
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 *	Mike Shaver		<shaver@ingenia.com>
 *
 *	This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

/*
 *	Changes:
 *
 *	Lars Fenneberg			:	fixed MTU setting on receipt
 *						of an RA.
 *
 *	Janos Farkas			:	kmalloc failure checks
 *	Alexey Kuznetsov		:	state machine reworked
 *						and moved to net/core.
 *	Pekka Savola			:	RFC2461 validation
 *	YOSHIFUJI Hideaki @USAGI	:	Verify ND options properly
 */

/* Set to 3 to get tracing... */
#define ND_DEBUG 1

#define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0)
#define ND_NOPRINTK(x...) do { ; } while(0)
#define ND_PRINTK0 ND_PRINTK
#define ND_PRINTK1 ND_NOPRINTK
#define ND_PRINTK2 ND_NOPRINTK
#define ND_PRINTK3 ND_NOPRINTK
#if ND_DEBUG >= 1
#undef ND_PRINTK1
#define ND_PRINTK1 ND_PRINTK
#endif
#if ND_DEBUG >= 2
#undef ND_PRINTK2
#define ND_PRINTK2 ND_PRINTK
#endif
#if ND_DEBUG >= 3
#undef ND_PRINTK3
#define ND_PRINTK3 ND_PRINTK
#endif

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/sched.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/route.h>
#include <linux/init.h>
#include <linux/rcupdate.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif

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#include <linux/if_addr.h>
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#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/jhash.h>

#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/ndisc.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/icmp.h>

#include <net/flow.h>
#include <net/ip6_checksum.h>
#include <linux/proc_fs.h>

#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>

static struct socket *ndisc_socket;

static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
static int ndisc_constructor(struct neighbour *neigh);
static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
static int pndisc_constructor(struct pneigh_entry *n);
static void pndisc_destructor(struct pneigh_entry *n);
static void pndisc_redo(struct sk_buff *skb);

static struct neigh_ops ndisc_generic_ops = {
	.family =		AF_INET6,
	.solicit =		ndisc_solicit,
	.error_report =		ndisc_error_report,
	.output =		neigh_resolve_output,
	.connected_output =	neigh_connected_output,
	.hh_output =		dev_queue_xmit,
	.queue_xmit =		dev_queue_xmit,
};

static struct neigh_ops ndisc_hh_ops = {
	.family =		AF_INET6,
	.solicit =		ndisc_solicit,
	.error_report =		ndisc_error_report,
	.output =		neigh_resolve_output,
	.connected_output =	neigh_resolve_output,
	.hh_output =		dev_queue_xmit,
	.queue_xmit =		dev_queue_xmit,
};


static struct neigh_ops ndisc_direct_ops = {
	.family =		AF_INET6,
	.output =		dev_queue_xmit,
	.connected_output =	dev_queue_xmit,
	.hh_output =		dev_queue_xmit,
	.queue_xmit =		dev_queue_xmit,
};

struct neigh_table nd_tbl = {
	.family =	AF_INET6,
	.entry_size =	sizeof(struct neighbour) + sizeof(struct in6_addr),
	.key_len =	sizeof(struct in6_addr),
	.hash =		ndisc_hash,
	.constructor =	ndisc_constructor,
	.pconstructor =	pndisc_constructor,
	.pdestructor =	pndisc_destructor,
	.proxy_redo =	pndisc_redo,
	.id =		"ndisc_cache",
	.parms = {
		.tbl =			&nd_tbl,
		.base_reachable_time =	30 * HZ,
		.retrans_time =	 1 * HZ,
		.gc_staletime =	60 * HZ,
		.reachable_time =		30 * HZ,
		.delay_probe_time =	 5 * HZ,
		.queue_len =		 3,
		.ucast_probes =	 3,
		.mcast_probes =	 3,
		.anycast_delay =	 1 * HZ,
		.proxy_delay =		(8 * HZ) / 10,
		.proxy_qlen =		64,
	},
	.gc_interval =	  30 * HZ,
	.gc_thresh1 =	 128,
	.gc_thresh2 =	 512,
	.gc_thresh3 =	1024,
};

/* ND options */
struct ndisc_options {
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	struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
#ifdef CONFIG_IPV6_ROUTE_INFO
	struct nd_opt_hdr *nd_opts_ri;
	struct nd_opt_hdr *nd_opts_ri_end;
#endif
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};

#define nd_opts_src_lladdr	nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
#define nd_opts_tgt_lladdr	nd_opt_array[ND_OPT_TARGET_LL_ADDR]
#define nd_opts_pi		nd_opt_array[ND_OPT_PREFIX_INFO]
#define nd_opts_pi_end		nd_opt_array[__ND_OPT_PREFIX_INFO_END]
#define nd_opts_rh		nd_opt_array[ND_OPT_REDIRECT_HDR]
#define nd_opts_mtu		nd_opt_array[ND_OPT_MTU]

#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)

/*
 * Return the padding between the option length and the start of the
 * link addr.  Currently only IP-over-InfiniBand needs this, although
 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
 * also need a pad of 2.
 */
static int ndisc_addr_option_pad(unsigned short type)
{
	switch (type) {
	case ARPHRD_INFINIBAND: return 2;
	default:                return 0;
	}
}

static inline int ndisc_opt_addr_space(struct net_device *dev)
{
	return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type));
}

static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len,
				  unsigned short addr_type)
{
	int space = NDISC_OPT_SPACE(data_len);
	int pad   = ndisc_addr_option_pad(addr_type);

	opt[0] = type;
	opt[1] = space>>3;

	memset(opt + 2, 0, pad);
	opt   += pad;
	space -= pad;

	memcpy(opt+2, data, data_len);
	data_len += 2;
	opt += data_len;
	if ((space -= data_len) > 0)
		memset(opt, 0, space);
	return opt + space;
}

static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
					    struct nd_opt_hdr *end)
{
	int type;
	if (!cur || !end || cur >= end)
		return NULL;
	type = cur->nd_opt_type;
	do {
		cur = ((void *)cur) + (cur->nd_opt_len << 3);
	} while(cur < end && cur->nd_opt_type != type);
	return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
}

static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
						 struct ndisc_options *ndopts)
{
	struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;

	if (!nd_opt || opt_len < 0 || !ndopts)
		return NULL;
	memset(ndopts, 0, sizeof(*ndopts));
	while (opt_len) {
		int l;
		if (opt_len < sizeof(struct nd_opt_hdr))
			return NULL;
		l = nd_opt->nd_opt_len << 3;
		if (opt_len < l || l == 0)
			return NULL;
		switch (nd_opt->nd_opt_type) {
		case ND_OPT_SOURCE_LL_ADDR:
		case ND_OPT_TARGET_LL_ADDR:
		case ND_OPT_MTU:
		case ND_OPT_REDIRECT_HDR:
			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
				ND_PRINTK2(KERN_WARNING
					   "%s(): duplicated ND6 option found: type=%d\n",
					   __FUNCTION__,
					   nd_opt->nd_opt_type);
			} else {
				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
			}
			break;
		case ND_OPT_PREFIX_INFO:
			ndopts->nd_opts_pi_end = nd_opt;
			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0)
				ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
			break;
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#ifdef CONFIG_IPV6_ROUTE_INFO
		case ND_OPT_ROUTE_INFO:
			ndopts->nd_opts_ri_end = nd_opt;
			if (!ndopts->nd_opts_ri)
				ndopts->nd_opts_ri = nd_opt;
			break;
#endif
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		default:
			/*
			 * Unknown options must be silently ignored,
			 * to accommodate future extension to the protocol.
			 */
			ND_PRINTK2(KERN_NOTICE
				   "%s(): ignored unsupported option; type=%d, len=%d\n",
				   __FUNCTION__,
				   nd_opt->nd_opt_type, nd_opt->nd_opt_len);
		}
		opt_len -= l;
		nd_opt = ((void *)nd_opt) + l;
	}
	return ndopts;
}

static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
				      struct net_device *dev)
{
	u8 *lladdr = (u8 *)(p + 1);
	int lladdrlen = p->nd_opt_len << 3;
	int prepad = ndisc_addr_option_pad(dev->type);
	if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad))
		return NULL;
	return (lladdr + prepad);
}

int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
{
	switch (dev->type) {
	case ARPHRD_ETHER:
	case ARPHRD_IEEE802:	/* Not sure. Check it later. --ANK */
	case ARPHRD_FDDI:
		ipv6_eth_mc_map(addr, buf);
		return 0;
	case ARPHRD_IEEE802_TR:
		ipv6_tr_mc_map(addr,buf);
		return 0;
	case ARPHRD_ARCNET:
		ipv6_arcnet_mc_map(addr, buf);
		return 0;
	case ARPHRD_INFINIBAND:
		ipv6_ib_mc_map(addr, buf);
		return 0;
	default:
		if (dir) {
			memcpy(buf, dev->broadcast, dev->addr_len);
			return 0;
		}
	}
	return -EINVAL;
}

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EXPORT_SYMBOL(ndisc_mc_map);

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static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
{
	const u32 *p32 = pkey;
	u32 addr_hash, i;

	addr_hash = 0;
	for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++)
		addr_hash ^= *p32++;

	return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd);
}

static int ndisc_constructor(struct neighbour *neigh)
{
	struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
	struct net_device *dev = neigh->dev;
	struct inet6_dev *in6_dev;
	struct neigh_parms *parms;
	int is_multicast = ipv6_addr_is_multicast(addr);

	rcu_read_lock();
	in6_dev = in6_dev_get(dev);
	if (in6_dev == NULL) {
		rcu_read_unlock();
		return -EINVAL;
	}

	parms = in6_dev->nd_parms;
	__neigh_parms_put(neigh->parms);
	neigh->parms = neigh_parms_clone(parms);
	rcu_read_unlock();

	neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
	if (dev->hard_header == NULL) {
		neigh->nud_state = NUD_NOARP;
		neigh->ops = &ndisc_direct_ops;
		neigh->output = neigh->ops->queue_xmit;
	} else {
		if (is_multicast) {
			neigh->nud_state = NUD_NOARP;
			ndisc_mc_map(addr, neigh->ha, dev, 1);
		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
			neigh->nud_state = NUD_NOARP;
			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
			if (dev->flags&IFF_LOOPBACK)
				neigh->type = RTN_LOCAL;
		} else if (dev->flags&IFF_POINTOPOINT) {
			neigh->nud_state = NUD_NOARP;
			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
		}
		if (dev->hard_header_cache)
			neigh->ops = &ndisc_hh_ops;
		else
			neigh->ops = &ndisc_generic_ops;
		if (neigh->nud_state&NUD_VALID)
			neigh->output = neigh->ops->connected_output;
		else
			neigh->output = neigh->ops->output;
	}
	in6_dev_put(in6_dev);
	return 0;
}

static int pndisc_constructor(struct pneigh_entry *n)
{
	struct in6_addr *addr = (struct in6_addr*)&n->key;
	struct in6_addr maddr;
	struct net_device *dev = n->dev;

	if (dev == NULL || __in6_dev_get(dev) == NULL)
		return -EINVAL;
	addrconf_addr_solict_mult(addr, &maddr);
	ipv6_dev_mc_inc(dev, &maddr);
	return 0;
}

static void pndisc_destructor(struct pneigh_entry *n)
{
	struct in6_addr *addr = (struct in6_addr*)&n->key;
	struct in6_addr maddr;
	struct net_device *dev = n->dev;

	if (dev == NULL || __in6_dev_get(dev) == NULL)
		return;
	addrconf_addr_solict_mult(addr, &maddr);
	ipv6_dev_mc_dec(dev, &maddr);
}

/*
 *	Send a Neighbour Advertisement
 */

static inline void ndisc_flow_init(struct flowi *fl, u8 type,
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			    struct in6_addr *saddr, struct in6_addr *daddr,
			    int oif)
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{
	memset(fl, 0, sizeof(*fl));
	ipv6_addr_copy(&fl->fl6_src, saddr);
	ipv6_addr_copy(&fl->fl6_dst, daddr);
	fl->proto	 	= IPPROTO_ICMPV6;
	fl->fl_icmp_type	= type;
	fl->fl_icmp_code	= 0;
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	fl->oif			= oif;
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	security_sk_classify_flow(ndisc_socket->sk, fl);
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}

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static void __ndisc_send(struct net_device *dev,
			 struct neighbour *neigh,
			 struct in6_addr *daddr, struct in6_addr *saddr,
			 struct icmp6hdr *icmp6h, struct in6_addr *target,
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			 int llinfo)
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{
	struct flowi fl;
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	struct dst_entry *dst;
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	struct sock *sk = ndisc_socket->sk;
	struct sk_buff *skb;
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	struct icmp6hdr *hdr;
	struct inet6_dev *idev;
	int len;
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	int err;
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	u8 *opt, type;

	type = icmp6h->icmp6_type;
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	ndisc_flow_init(&fl, type, saddr, daddr,
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			dev->ifindex);
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	dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
	if (!dst)
		return;

	err = xfrm_lookup(&dst, &fl, NULL, 0);
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	if (err < 0)
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		return;

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	if (!dev->addr_len)
		llinfo = 0;

	len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
	if (llinfo)
		len += ndisc_opt_addr_space(dev);
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	skb = sock_alloc_send_skb(sk,
				  (MAX_HEADER + sizeof(struct ipv6hdr) +
				   len + LL_RESERVED_SPACE(dev)),
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				  1, &err);
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	if (!skb) {
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		ND_PRINTK0(KERN_ERR
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			   "ICMPv6 ND: %s() failed to allocate an skb.\n",
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			   __FUNCTION__);
		dst_release(dst);
		return;
	}

	skb_reserve(skb, LL_RESERVED_SPACE(dev));
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	ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
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	skb->transport_header = skb->tail;
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	skb_put(skb, len);
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	hdr = (struct icmp6hdr *)skb_transport_header(skb);
	memcpy(hdr, icmp6h, sizeof(*hdr));
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	opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
	if (target) {
		ipv6_addr_copy((struct in6_addr *)opt, target);
		opt += sizeof(*target);
	}
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	if (llinfo)
		ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
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				       dev->addr_len, dev->type);

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	hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
					   IPPROTO_ICMPV6,
					   csum_partial((__u8 *) hdr,
							len, 0));
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	skb->dst = dst;
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	idev = in6_dev_get(dst->dev);
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	IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
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	err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
	if (!err) {
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		ICMP6MSGOUT_INC_STATS(idev, type);
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		ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
	}

	if (likely(idev != NULL))
		in6_dev_put(idev);
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}
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static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
		   struct in6_addr *daddr, struct in6_addr *solicited_addr,
		   int router, int solicited, int override, int inc_opt)
{
	struct in6_addr tmpaddr;
	struct inet6_ifaddr *ifp;
	struct in6_addr *src_addr;
	struct icmp6hdr icmp6h = {
		.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
	};

	/* for anycast or proxy, solicited_addr != src_addr */
	ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
	if (ifp) {
		src_addr = solicited_addr;
		if (ifp->flags & IFA_F_OPTIMISTIC)
			override = 0;
		in6_ifa_put(ifp);
	} else {
		if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
			return;
		src_addr = &tmpaddr;
	}

	icmp6h.icmp6_router = router;
	icmp6h.icmp6_solicited = solicited;
	icmp6h.icmp6_override = override;

	__ndisc_send(dev, neigh, daddr, src_addr,
		     &icmp6h, solicited_addr,
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		     inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
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}

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void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
		   struct in6_addr *solicit,
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		   struct in6_addr *daddr, struct in6_addr *saddr)
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{
	struct in6_addr addr_buf;
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	struct icmp6hdr icmp6h = {
		.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
	};
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	if (saddr == NULL) {
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		if (ipv6_get_lladdr(dev, &addr_buf,
				   (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
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			return;
		saddr = &addr_buf;
	}

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	__ndisc_send(dev, neigh, daddr, saddr,
		     &icmp6h, solicit,
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		     !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
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}

void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
		   struct in6_addr *daddr)
{
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	struct icmp6hdr icmp6h = {
		.icmp6_type = NDISC_ROUTER_SOLICITATION,
	};
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	int send_sllao = dev->addr_len;

#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
	/*
	 * According to section 2.2 of RFC 4429, we must not
	 * send router solicitations with a sllao from
	 * optimistic addresses, but we may send the solicitation
	 * if we don't include the sllao.  So here we check
	 * if our address is optimistic, and if so, we
	 * supress the inclusion of the sllao.
	 */
	if (send_sllao) {
589
		struct inet6_ifaddr *ifp = ipv6_get_ifaddr(saddr, dev, 1);
590 591
		if (ifp) {
			if (ifp->flags & IFA_F_OPTIMISTIC)  {
592
				send_sllao = 0;
593
			}
594
			in6_ifa_put(ifp);
595 596 597 598 599
		} else {
			send_sllao = 0;
		}
	}
#endif
600 601
	__ndisc_send(dev, NULL, daddr, saddr,
		     &icmp6h, NULL,
602
		     send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
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}
604

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static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
{
	/*
	 *	"The sender MUST return an ICMP
	 *	 destination unreachable"
	 */
	dst_link_failure(skb);
	kfree_skb(skb);
}

/* Called with locked neigh: either read or both */

static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
{
	struct in6_addr *saddr = NULL;
	struct in6_addr mcaddr;
	struct net_device *dev = neigh->dev;
	struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
	int probes = atomic_read(&neigh->probes);

626 627
	if (skb && ipv6_chk_addr(&ipv6_hdr(skb)->saddr, dev, 1))
		saddr = &ipv6_hdr(skb)->saddr;
L
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628 629 630 631 632

	if ((probes -= neigh->parms->ucast_probes) < 0) {
		if (!(neigh->nud_state & NUD_VALID)) {
			ND_PRINTK1(KERN_DEBUG
				   "%s(): trying to ucast probe in NUD_INVALID: "
J
Joe Perches 已提交
633
				   NIP6_FMT "\n",
L
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634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649
				   __FUNCTION__,
				   NIP6(*target));
		}
		ndisc_send_ns(dev, neigh, target, target, saddr);
	} else if ((probes -= neigh->parms->app_probes) < 0) {
#ifdef CONFIG_ARPD
		neigh_app_ns(neigh);
#endif
	} else {
		addrconf_addr_solict_mult(target, &mcaddr);
		ndisc_send_ns(dev, NULL, target, &mcaddr, saddr);
	}
}

static void ndisc_recv_ns(struct sk_buff *skb)
{
650
	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
651 652
	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
	struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
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653
	u8 *lladdr = NULL;
654 655
	u32 ndoptlen = skb->tail - (skb->transport_header +
				    offsetof(struct nd_msg, opt));
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	struct ndisc_options ndopts;
	struct net_device *dev = skb->dev;
	struct inet6_ifaddr *ifp;
	struct inet6_dev *idev = NULL;
	struct neighbour *neigh;
661
	struct pneigh_entry *pneigh = NULL;
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662 663
	int dad = ipv6_addr_any(saddr);
	int inc;
664
	int is_router;
L
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665 666

	if (ipv6_addr_is_multicast(&msg->target)) {
667
		ND_PRINTK2(KERN_WARNING
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			   "ICMPv6 NS: multicast target address");
		return;
	}

	/*
	 * RFC2461 7.1.1:
	 * DAD has to be destined for solicited node multicast address.
	 */
	if (dad &&
	    !(daddr->s6_addr32[0] == htonl(0xff020000) &&
	      daddr->s6_addr32[1] == htonl(0x00000000) &&
	      daddr->s6_addr32[2] == htonl(0x00000001) &&
	      daddr->s6_addr [12] == 0xff )) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 NS: bad DAD packet (wrong destination)\n");
		return;
	}

	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
687
		ND_PRINTK2(KERN_WARNING
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			   "ICMPv6 NS: invalid ND options\n");
		return;
	}

	if (ndopts.nd_opts_src_lladdr) {
		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
		if (!lladdr) {
			ND_PRINTK2(KERN_WARNING
				   "ICMPv6 NS: invalid link-layer address length\n");
			return;
		}

		/* RFC2461 7.1.1:
701 702
		 *	If the IP source address is the unspecified address,
		 *	there MUST NOT be source link-layer address option
L
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		 *	in the message.
		 */
		if (dad) {
706
			ND_PRINTK2(KERN_WARNING
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				   "ICMPv6 NS: bad DAD packet (link-layer address option)\n");
			return;
		}
	}

	inc = ipv6_addr_is_multicast(daddr);

	if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
715 716 717 718

		if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
			if (dad) {
				if (dev->type == ARPHRD_IEEE802_TR) {
719 720
					const unsigned char *sadr;
					sadr = skb_mac_header(skb);
721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737
					if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
					    sadr[9] == dev->dev_addr[1] &&
					    sadr[10] == dev->dev_addr[2] &&
					    sadr[11] == dev->dev_addr[3] &&
					    sadr[12] == dev->dev_addr[4] &&
					    sadr[13] == dev->dev_addr[5]) {
						/* looped-back to us */
						goto out;
					}
				}

				/*
				 * We are colliding with another node
				 * who is doing DAD
				 * so fail our DAD process
				 */
				addrconf_dad_failure(ifp);
738
				return;
739 740 741 742 743 744 745 746
			} else {
				/*
				 * This is not a dad solicitation.
				 * If we are an optimistic node,
				 * we should respond.
				 * Otherwise, we should ignore it.
				 */
				if (!(ifp->flags & IFA_F_OPTIMISTIC))
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747 748 749 750 751 752 753 754 755 756 757 758 759
					goto out;
			}
		}

		idev = ifp->idev;
	} else {
		idev = in6_dev_get(dev);
		if (!idev) {
			/* XXX: count this drop? */
			return;
		}

		if (ipv6_chk_acast_addr(dev, &msg->target) ||
760
		    (idev->cnf.forwarding &&
761
		     (ipv6_devconf.proxy_ndp || idev->cnf.proxy_ndp) &&
762 763
		     (pneigh = pneigh_lookup(&nd_tbl,
					     &msg->target, dev, 0)) != NULL)) {
764
			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
L
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			    skb->pkt_type != PACKET_HOST &&
			    inc != 0 &&
			    idev->nd_parms->proxy_delay != 0) {
				/*
				 * for anycast or proxy,
770 771
				 * sender should delay its response
				 * by a random time between 0 and
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772 773 774 775 776 777 778 779 780 781 782 783
				 * MAX_ANYCAST_DELAY_TIME seconds.
				 * (RFC2461) -- yoshfuji
				 */
				struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
				if (n)
					pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
				goto out;
			}
		} else
			goto out;
	}

784
	is_router = !!(pneigh ? pneigh->flags & NTF_ROUTER : idev->cnf.forwarding);
785

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	if (dad) {
		struct in6_addr maddr;

		ipv6_addr_all_nodes(&maddr);
		ndisc_send_na(dev, NULL, &maddr, &msg->target,
791
			      is_router, 0, (ifp != NULL), 1);
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		goto out;
	}

	if (inc)
		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
	else
		NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);

800
	/*
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	 *	update / create cache entry
	 *	for the source address
	 */
	neigh = __neigh_lookup(&nd_tbl, saddr, dev,
			       !inc || lladdr || !dev->addr_len);
	if (neigh)
807
		neigh_update(neigh, lladdr, NUD_STALE,
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808 809 810 811
			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
			     NEIGH_UPDATE_F_OVERRIDE);
	if (neigh || !dev->hard_header) {
		ndisc_send_na(dev, neigh, saddr, &msg->target,
812
			      is_router,
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813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828
			      1, (ifp != NULL && inc), inc);
		if (neigh)
			neigh_release(neigh);
	}

out:
	if (ifp)
		in6_ifa_put(ifp);
	else
		in6_dev_put(idev);

	return;
}

static void ndisc_recv_na(struct sk_buff *skb)
{
829
	struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
830 831
	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
	struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
L
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832
	u8 *lladdr = NULL;
833 834
	u32 ndoptlen = skb->tail - (skb->transport_header +
				    offsetof(struct nd_msg, opt));
L
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835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857
	struct ndisc_options ndopts;
	struct net_device *dev = skb->dev;
	struct inet6_ifaddr *ifp;
	struct neighbour *neigh;

	if (skb->len < sizeof(struct nd_msg)) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 NA: packet too short\n");
		return;
	}

	if (ipv6_addr_is_multicast(&msg->target)) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 NA: target address is multicast.\n");
		return;
	}

	if (ipv6_addr_is_multicast(daddr) &&
	    msg->icmph.icmp6_solicited) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 NA: solicited NA is multicasted.\n");
		return;
	}
858

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859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895
	if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 NS: invalid ND option\n");
		return;
	}
	if (ndopts.nd_opts_tgt_lladdr) {
		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
		if (!lladdr) {
			ND_PRINTK2(KERN_WARNING
				   "ICMPv6 NA: invalid link-layer address length\n");
			return;
		}
	}
	if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1))) {
		if (ifp->flags & IFA_F_TENTATIVE) {
			addrconf_dad_failure(ifp);
			return;
		}
		/* What should we make now? The advertisement
		   is invalid, but ndisc specs say nothing
		   about it. It could be misconfiguration, or
		   an smart proxy agent tries to help us :-)
		 */
		ND_PRINTK1(KERN_WARNING
			   "ICMPv6 NA: someone advertises our address on %s!\n",
			   ifp->idev->dev->name);
		in6_ifa_put(ifp);
		return;
	}
	neigh = neigh_lookup(&nd_tbl, &msg->target, dev);

	if (neigh) {
		u8 old_flags = neigh->flags;

		if (neigh->nud_state & NUD_FAILED)
			goto out;

896 897 898 899 900 901
		/*
		 * Don't update the neighbor cache entry on a proxy NA from
		 * ourselves because either the proxied node is off link or it
		 * has already sent a NA to us.
		 */
		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
902 903 904
		    ipv6_devconf.forwarding && ipv6_devconf.proxy_ndp &&
		    pneigh_lookup(&nd_tbl, &msg->target, dev, 0)) {
			/* XXX: idev->cnf.prixy_ndp */
905
			goto out;
906
		}
907

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908 909 910 911 912 913 914 915 916 917 918 919 920 921
		neigh_update(neigh, lladdr,
			     msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
			     (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
			     (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0));

		if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
			/*
			 * Change: router to host
			 */
			struct rt6_info *rt;
			rt = rt6_get_dflt_router(saddr, dev);
			if (rt)
922
				ip6_del_rt(rt);
L
Linus Torvalds 已提交
923 924 925 926 927 928 929 930 931
		}

out:
		neigh_release(neigh);
	}
}

static void ndisc_recv_rs(struct sk_buff *skb)
{
932
	struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
L
Linus Torvalds 已提交
933 934 935
	unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
	struct neighbour *neigh;
	struct inet6_dev *idev;
936
	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
L
Linus Torvalds 已提交
937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988
	struct ndisc_options ndopts;
	u8 *lladdr = NULL;

	if (skb->len < sizeof(*rs_msg))
		return;

	idev = in6_dev_get(skb->dev);
	if (!idev) {
		if (net_ratelimit())
			ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
		return;
	}

	/* Don't accept RS if we're not in router mode */
	if (!idev->cnf.forwarding)
		goto out;

	/*
	 * Don't update NCE if src = ::;
	 * this implies that the source node has no ip address assigned yet.
	 */
	if (ipv6_addr_any(saddr))
		goto out;

	/* Parse ND options */
	if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) {
		if (net_ratelimit())
			ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n");
		goto out;
	}

	if (ndopts.nd_opts_src_lladdr) {
		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
					     skb->dev);
		if (!lladdr)
			goto out;
	}

	neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
	if (neigh) {
		neigh_update(neigh, lladdr, NUD_STALE,
			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
			     NEIGH_UPDATE_F_OVERRIDE|
			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER);
		neigh_release(neigh);
	}
out:
	in6_dev_put(idev);
}

static void ndisc_router_discovery(struct sk_buff *skb)
{
989
	struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
L
Linus Torvalds 已提交
990 991
	struct neighbour *neigh = NULL;
	struct inet6_dev *in6_dev;
992
	struct rt6_info *rt = NULL;
L
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993 994 995
	int lifetime;
	struct ndisc_options ndopts;
	int optlen;
996
	unsigned int pref = 0;
L
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997 998 999

	__u8 * opt = (__u8 *)(ra_msg + 1);

1000
	optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
L
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1001

1002
	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
L
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1003 1004 1005 1006 1007
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 RA: source address is not link-local.\n");
		return;
	}
	if (optlen < 0) {
1008
		ND_PRINTK2(KERN_WARNING
L
Linus Torvalds 已提交
1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
			   "ICMPv6 RA: packet too short\n");
		return;
	}

	/*
	 *	set the RA_RECV flag in the interface
	 */

	in6_dev = in6_dev_get(skb->dev);
	if (in6_dev == NULL) {
		ND_PRINTK0(KERN_ERR
			   "ICMPv6 RA: can't find inet6 device for %s.\n",
			   skb->dev->name);
		return;
	}
	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) {
		in6_dev_put(in6_dev);
		return;
	}

	if (!ndisc_parse_options(opt, optlen, &ndopts)) {
		in6_dev_put(in6_dev);
		ND_PRINTK2(KERN_WARNING
			   "ICMP6 RA: invalid ND options\n");
		return;
	}

	if (in6_dev->if_flags & IF_RS_SENT) {
		/*
		 *	flag that an RA was received after an RS was sent
		 *	out on this interface.
		 */
		in6_dev->if_flags |= IF_RA_RCVD;
	}

	/*
	 * Remember the managed/otherconf flags from most recently
	 * received RA message (RFC 2462) -- yoshfuji
	 */
	in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
				IF_RA_OTHERCONF)) |
				(ra_msg->icmph.icmp6_addrconf_managed ?
					IF_RA_MANAGED : 0) |
				(ra_msg->icmph.icmp6_addrconf_other ?
					IF_RA_OTHERCONF : 0);

1055 1056 1057
	if (!in6_dev->cnf.accept_ra_defrtr)
		goto skip_defrtr;

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1058 1059
	lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);

1060 1061 1062
#ifdef CONFIG_IPV6_ROUTER_PREF
	pref = ra_msg->icmph.icmp6_router_pref;
	/* 10b is handled as if it were 00b (medium) */
1063
	if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1064
	    !in6_dev->cnf.accept_ra_rtr_pref)
1065 1066 1067
		pref = ICMPV6_ROUTER_PREF_MEDIUM;
#endif

1068
	rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev);
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1069 1070 1071 1072 1073 1074

	if (rt)
		neigh = rt->rt6i_nexthop;

	if (rt && lifetime == 0) {
		neigh_clone(neigh);
1075
		ip6_del_rt(rt);
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1076 1077 1078 1079 1080 1081 1082
		rt = NULL;
	}

	if (rt == NULL && lifetime) {
		ND_PRINTK3(KERN_DEBUG
			   "ICMPv6 RA: adding default router.\n");

1083
		rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref);
L
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1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101
		if (rt == NULL) {
			ND_PRINTK0(KERN_ERR
				   "ICMPv6 RA: %s() failed to add default route.\n",
				   __FUNCTION__);
			in6_dev_put(in6_dev);
			return;
		}

		neigh = rt->rt6i_nexthop;
		if (neigh == NULL) {
			ND_PRINTK0(KERN_ERR
				   "ICMPv6 RA: %s() got default router without neighbour.\n",
				   __FUNCTION__);
			dst_release(&rt->u.dst);
			in6_dev_put(in6_dev);
			return;
		}
		neigh->flags |= NTF_ROUTER;
1102 1103
	} else if (rt) {
		rt->rt6i_flags |= (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
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1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114
	}

	if (rt)
		rt->rt6i_expires = jiffies + (HZ * lifetime);

	if (ra_msg->icmph.icmp6_hop_limit) {
		in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
		if (rt)
			rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
	}

1115 1116
skip_defrtr:

L
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1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
	/*
	 *	Update Reachable Time and Retrans Timer
	 */

	if (in6_dev->nd_parms) {
		unsigned long rtime = ntohl(ra_msg->retrans_timer);

		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
			rtime = (rtime*HZ)/1000;
			if (rtime < HZ/10)
				rtime = HZ/10;
			in6_dev->nd_parms->retrans_time = rtime;
			in6_dev->tstamp = jiffies;
			inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
		}

		rtime = ntohl(ra_msg->reachable_time);
		if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
			rtime = (rtime*HZ)/1000;

			if (rtime < HZ/10)
				rtime = HZ/10;

			if (rtime != in6_dev->nd_parms->base_reachable_time) {
				in6_dev->nd_parms->base_reachable_time = rtime;
				in6_dev->nd_parms->gc_staletime = 3 * rtime;
				in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
				in6_dev->tstamp = jiffies;
				inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
			}
		}
	}

	/*
	 *	Process options.
	 */

	if (!neigh)
1155
		neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
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				       skb->dev, 1);
	if (neigh) {
		u8 *lladdr = NULL;
		if (ndopts.nd_opts_src_lladdr) {
			lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
						     skb->dev);
			if (!lladdr) {
				ND_PRINTK2(KERN_WARNING
					   "ICMPv6 RA: invalid link-layer address length\n");
				goto out;
			}
		}
		neigh_update(neigh, lladdr, NUD_STALE,
			     NEIGH_UPDATE_F_WEAK_OVERRIDE|
			     NEIGH_UPDATE_F_OVERRIDE|
			     NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
			     NEIGH_UPDATE_F_ISROUTER);
	}

1175
#ifdef CONFIG_IPV6_ROUTE_INFO
1176
	if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1177 1178 1179 1180
		struct nd_opt_hdr *p;
		for (p = ndopts.nd_opts_ri;
		     p;
		     p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1181 1182
			if (((struct route_info *)p)->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
				continue;
1183
			rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3,
1184
				      &ipv6_hdr(skb)->saddr);
1185 1186 1187 1188
		}
	}
#endif

1189
	if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
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		struct nd_opt_hdr *p;
		for (p = ndopts.nd_opts_pi;
		     p;
		     p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
			addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
		}
	}

	if (ndopts.nd_opts_mtu) {
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		__be32 n;
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		u32 mtu;

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		memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
		mtu = ntohl(n);
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		if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
			ND_PRINTK2(KERN_WARNING
				   "ICMPv6 RA: invalid mtu: %d\n",
				   mtu);
		} else if (in6_dev->cnf.mtu6 != mtu) {
			in6_dev->cnf.mtu6 = mtu;

			if (rt)
				rt->u.dst.metrics[RTAX_MTU-1] = mtu;

			rt6_mtu_change(skb->dev, mtu);
		}
	}
1218

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	if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 RA: invalid RA options");
	}
out:
	if (rt)
		dst_release(&rt->u.dst);
	else if (neigh)
		neigh_release(neigh);
	in6_dev_put(in6_dev);
}

static void ndisc_redirect_rcv(struct sk_buff *skb)
{
	struct inet6_dev *in6_dev;
	struct icmp6hdr *icmph;
	struct in6_addr *dest;
	struct in6_addr *target;	/* new first hop to destination */
	struct neighbour *neigh;
	int on_link = 0;
	struct ndisc_options ndopts;
	int optlen;
	u8 *lladdr = NULL;

1243
	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
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		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 Redirect: source address is not link-local.\n");
		return;
	}

1249
	optlen = skb->tail - skb->transport_header;
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	optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);

	if (optlen < 0) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 Redirect: packet too short\n");
		return;
	}

1258
	icmph = icmp6_hdr(skb);
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	target = (struct in6_addr *) (icmph + 1);
	dest = target + 1;

	if (ipv6_addr_is_multicast(dest)) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 Redirect: destination address is multicast.\n");
		return;
	}

	if (ipv6_addr_equal(dest, target)) {
		on_link = 1;
1270 1271
	} else if (ipv6_addr_type(target) !=
		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1272
		ND_PRINTK2(KERN_WARNING
1273
			   "ICMPv6 Redirect: target address is not link-local unicast.\n");
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		return;
	}

	in6_dev = in6_dev_get(skb->dev);
	if (!in6_dev)
		return;
	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
		in6_dev_put(in6_dev);
		return;
	}

1285
	/* RFC2461 8.1:
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	 *	The IP source address of the Redirect MUST be the same as the current
	 *	first-hop router for the specified ICMP Destination Address.
	 */
1289

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	if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 Redirect: invalid ND options\n");
		in6_dev_put(in6_dev);
		return;
	}
	if (ndopts.nd_opts_tgt_lladdr) {
		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
					     skb->dev);
		if (!lladdr) {
			ND_PRINTK2(KERN_WARNING
				   "ICMPv6 Redirect: invalid link-layer address length\n");
			in6_dev_put(in6_dev);
			return;
		}
	}

	neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
	if (neigh) {
1309 1310
		rt6_redirect(dest, &ipv6_hdr(skb)->daddr,
			     &ipv6_hdr(skb)->saddr, neigh, lladdr,
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			     on_link);
		neigh_release(neigh);
	}
	in6_dev_put(in6_dev);
}

void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
			 struct in6_addr *target)
{
	struct sock *sk = ndisc_socket->sk;
	int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
	struct sk_buff *buff;
	struct icmp6hdr *icmph;
	struct in6_addr saddr_buf;
	struct in6_addr *addrp;
	struct net_device *dev;
	struct rt6_info *rt;
	struct dst_entry *dst;
	struct inet6_dev *idev;
	struct flowi fl;
	u8 *opt;
	int rd_len;
	int err;
	int hlen;
	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;

	dev = skb->dev;

1339
	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
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		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 Redirect: no link-local address on %s\n",
			   dev->name);
1343 1344
		return;
	}
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1346
	if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1347
	    ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1348
		ND_PRINTK2(KERN_WARNING
1349
			"ICMPv6 Redirect: target address is not link-local unicast.\n");
1350 1351 1352
		return;
	}

1353
	ndisc_flow_init(&fl, NDISC_REDIRECT, &saddr_buf, &ipv6_hdr(skb)->saddr,
1354
			dev->ifindex);
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	dst = ip6_route_output(NULL, &fl);
	if (dst == NULL)
		return;

	err = xfrm_lookup(&dst, &fl, NULL, 0);
1361
	if (err)
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		return;

	rt = (struct rt6_info *) dst;

	if (rt->rt6i_flags & RTF_GATEWAY) {
		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 Redirect: destination is not a neighbour.\n");
		dst_release(dst);
		return;
	}
	if (!xrlim_allow(dst, 1*HZ)) {
		dst_release(dst);
		return;
	}

	if (dev->addr_len) {
		read_lock_bh(&neigh->lock);
		if (neigh->nud_state & NUD_VALID) {
			memcpy(ha_buf, neigh->ha, dev->addr_len);
			read_unlock_bh(&neigh->lock);
			ha = ha_buf;
			len += ndisc_opt_addr_space(dev);
		} else
			read_unlock_bh(&neigh->lock);
	}

	rd_len = min_t(unsigned int,
		     IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
	rd_len &= ~0x7;
	len += rd_len;

1393 1394 1395
	buff = sock_alloc_send_skb(sk,
				   (MAX_HEADER + sizeof(struct ipv6hdr) +
				    len + LL_RESERVED_SPACE(dev)),
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				   1, &err);
	if (buff == NULL) {
		ND_PRINTK0(KERN_ERR
			   "ICMPv6 Redirect: %s() failed to allocate an skb.\n",
			   __FUNCTION__);
		dst_release(dst);
		return;
	}

	hlen = 0;

	skb_reserve(buff, LL_RESERVED_SPACE(dev));
1408
	ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
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		   IPPROTO_ICMPV6, len);

1411
	skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
1412 1413
	skb_put(buff, len);
	icmph = icmp6_hdr(buff);
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	memset(icmph, 0, sizeof(struct icmp6hdr));
	icmph->icmp6_type = NDISC_REDIRECT;

	/*
	 *	copy target and destination addresses
	 */

	addrp = (struct in6_addr *)(icmph + 1);
	ipv6_addr_copy(addrp, target);
	addrp++;
1425
	ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr);
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	opt = (u8*) (addrp + 1);

	/*
	 *	include target_address option
	 */

	if (ha)
		opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha,
					     dev->addr_len, dev->type);

	/*
	 *	build redirect option and copy skb over to the new packet.
	 */

1441
	memset(opt, 0, 8);
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	*(opt++) = ND_OPT_REDIRECT_HDR;
	*(opt++) = (rd_len >> 3);
	opt += 6;

1446
	memcpy(opt, ipv6_hdr(skb), rd_len - 8);
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1448
	icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
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					     len, IPPROTO_ICMPV6,
					     csum_partial((u8 *) icmph, len, 0));

	buff->dst = dst;
	idev = in6_dev_get(dst->dev);
1454
	IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
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	err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, buff, NULL, dst->dev, dst_output);
	if (!err) {
1457
		ICMP6MSGOUT_INC_STATS(idev, NDISC_REDIRECT);
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		ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
	}

	if (likely(idev != NULL))
		in6_dev_put(idev);
}

static void pndisc_redo(struct sk_buff *skb)
{
1467
	ndisc_recv_ns(skb);
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	kfree_skb(skb);
}

int ndisc_rcv(struct sk_buff *skb)
{
	struct nd_msg *msg;

	if (!pskb_may_pull(skb, skb->len))
		return 0;

1478
	msg = (struct nd_msg *)skb_transport_header(skb);
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1480
	__skb_push(skb, skb->data - skb_transport_header(skb));
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1482
	if (ipv6_hdr(skb)->hop_limit != 255) {
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		ND_PRINTK2(KERN_WARNING
			   "ICMPv6 NDISC: invalid hop-limit: %d\n",
1485
			   ipv6_hdr(skb)->hop_limit);
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		return 0;
	}

	if (msg->icmph.icmp6_code != 0) {
1490
		ND_PRINTK2(KERN_WARNING
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			   "ICMPv6 NDISC: invalid ICMPv6 code: %d\n",
			   msg->icmph.icmp6_code);
		return 0;
	}

1496 1497
	memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));

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	switch (msg->icmph.icmp6_type) {
	case NDISC_NEIGHBOUR_SOLICITATION:
		ndisc_recv_ns(skb);
		break;

	case NDISC_NEIGHBOUR_ADVERTISEMENT:
		ndisc_recv_na(skb);
		break;

	case NDISC_ROUTER_SOLICITATION:
		ndisc_recv_rs(skb);
		break;

	case NDISC_ROUTER_ADVERTISEMENT:
		ndisc_router_discovery(skb);
		break;

	case NDISC_REDIRECT:
		ndisc_redirect_rcv(skb);
		break;
1518
	}
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	return 0;
}

static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;

1527 1528 1529
	if (dev->nd_net != &init_net)
		return NOTIFY_DONE;

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	switch (event) {
	case NETDEV_CHANGEADDR:
		neigh_changeaddr(&nd_tbl, dev);
		fib6_run_gc(~0UL);
		break;
	case NETDEV_DOWN:
		neigh_ifdown(&nd_tbl, dev);
		fib6_run_gc(~0UL);
		break;
	default:
		break;
	}

	return NOTIFY_DONE;
}

static struct notifier_block ndisc_netdev_notifier = {
	.notifier_call = ndisc_netdev_event,
};

#ifdef CONFIG_SYSCTL
static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
					 const char *func, const char *dev_name)
{
	static char warncomm[TASK_COMM_LEN];
	static int warned;
	if (strcmp(warncomm, current->comm) && warned < 5) {
		strcpy(warncomm, current->comm);
		printk(KERN_WARNING
			"process `%s' is using deprecated sysctl (%s) "
			"net.ipv6.neigh.%s.%s; "
			"Use net.ipv6.neigh.%s.%s_ms "
			"instead.\n",
			warncomm, func,
			dev_name, ctl->procname,
			dev_name, ctl->procname);
		warned++;
	}
}

int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct net_device *dev = ctl->extra1;
	struct inet6_dev *idev;
	int ret;

	if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
	    ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
		ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");

	switch (ctl->ctl_name) {
	case NET_NEIGH_RETRANS_TIME:
		ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
		break;
	case NET_NEIGH_REACHABLE_TIME:
		ret = proc_dointvec_jiffies(ctl, write,
					    filp, buffer, lenp, ppos);
		break;
	case NET_NEIGH_RETRANS_TIME_MS:
	case NET_NEIGH_REACHABLE_TIME_MS:
		ret = proc_dointvec_ms_jiffies(ctl, write,
					       filp, buffer, lenp, ppos);
		break;
	default:
		ret = -1;
	}

	if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
		if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
		    ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
			idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
		idev->tstamp = jiffies;
		inet6_ifinfo_notify(RTM_NEWLINK, idev);
		in6_dev_put(idev);
	}
	return ret;
}

static int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl, int __user *name,
					int nlen, void __user *oldval,
					size_t __user *oldlenp,
1611
					void __user *newval, size_t newlen)
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{
	struct net_device *dev = ctl->extra1;
	struct inet6_dev *idev;
	int ret;

	if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME ||
	    ctl->ctl_name == NET_NEIGH_REACHABLE_TIME)
		ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default");

	switch (ctl->ctl_name) {
	case NET_NEIGH_REACHABLE_TIME:
		ret = sysctl_jiffies(ctl, name, nlen,
1624
				     oldval, oldlenp, newval, newlen);
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		break;
	case NET_NEIGH_RETRANS_TIME_MS:
	case NET_NEIGH_REACHABLE_TIME_MS:
		 ret = sysctl_ms_jiffies(ctl, name, nlen,
1629
					 oldval, oldlenp, newval, newlen);
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		 break;
	default:
		ret = 0;
	}

	if (newval && newlen && ret > 0 &&
	    dev && (idev = in6_dev_get(dev)) != NULL) {
		if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME ||
		    ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS)
			idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time);
		idev->tstamp = jiffies;
		inet6_ifinfo_notify(RTM_NEWLINK, idev);
		in6_dev_put(idev);
	}

	return ret;
}

#endif

int __init ndisc_init(struct net_proto_family *ops)
{
	struct ipv6_pinfo *np;
	struct sock *sk;
1654
	int err;
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	err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, &ndisc_socket);
	if (err < 0) {
		ND_PRINTK0(KERN_ERR
1659
			   "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n",
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			   err);
		ndisc_socket = NULL; /* For safety. */
		return err;
	}

	sk = ndisc_socket->sk;
	np = inet6_sk(sk);
	sk->sk_allocation = GFP_ATOMIC;
	np->hop_limit = 255;
	/* Do not loopback ndisc messages */
	np->mc_loop = 0;
	sk->sk_prot->unhash(sk);

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	/*
	 * Initialize the neighbour table
	 */

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	neigh_table_init(&nd_tbl);

#ifdef CONFIG_SYSCTL
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	neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH,
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			      "ipv6",
			      &ndisc_ifinfo_sysctl_change,
			      &ndisc_ifinfo_sysctl_strategy);
#endif

	register_netdevice_notifier(&ndisc_netdev_notifier);
	return 0;
}

void ndisc_cleanup(void)
{
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	unregister_netdevice_notifier(&ndisc_netdev_notifier);
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#ifdef CONFIG_SYSCTL
	neigh_sysctl_unregister(&nd_tbl.parms);
#endif
	neigh_table_clear(&nd_tbl);
	sock_release(ndisc_socket);
	ndisc_socket = NULL; /* For safety. */
}