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ndisc.c
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/*
* Neighbour Discovery for IPv6
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <[email protected]>
* Mike Shaver <[email protected]>
*
* 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
#include <linux/if_addr.h>
#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 {
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
};
#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;
#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
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;
}
EXPORT_SYMBOL(ndisc_mc_map);
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,
struct in6_addr *saddr, struct in6_addr *daddr,
int oif)
{
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;
fl->oif = oif;
security_sk_classify_flow(ndisc_socket->sk, fl);
}
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,
int llinfo, int icmp6_mib_outnd)
{
struct flowi fl;
struct dst_entry *dst;
struct sock *sk = ndisc_socket->sk;
struct sk_buff *skb;
struct icmp6hdr *hdr;
struct inet6_dev *idev;
int len;
int err;
u8 *opt;
ndisc_flow_init(&fl, icmp6h->icmp6_type, saddr, daddr,
dev->ifindex);
dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
if (!dst)
return;
err = xfrm_lookup(&dst, &fl, NULL, 0);
if (err < 0)
return;
if (!dev->addr_len)
llinfo = 0;
len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
if (llinfo)
len += ndisc_opt_addr_space(dev);
skb = sock_alloc_send_skb(sk,
(MAX_HEADER + sizeof(struct ipv6hdr) +
len + LL_RESERVED_SPACE(dev)),
1, &err);
if (!skb) {
ND_PRINTK0(KERN_ERR
"ICMPv6 ND: %s() failed to allocate an skb.\n",
__FUNCTION__);
dst_release(dst);
return;
}
skb_reserve(skb, LL_RESERVED_SPACE(dev));
ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
skb->transport_header = skb->tail;
skb_put(skb, len);
hdr = (struct icmp6hdr *)skb_transport_header(skb);
memcpy(hdr, icmp6h, sizeof(*hdr));
opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
if (target) {
ipv6_addr_copy((struct in6_addr *)opt, target);
opt += sizeof(*target);
}
if (llinfo)
ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
dev->addr_len, dev->type);
hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
IPPROTO_ICMPV6,
csum_partial((__u8 *) hdr,
len, 0));
skb->dst = dst;
idev = in6_dev_get(dst->dev);
IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
if (!err) {
ICMP6_INC_STATS(idev, icmp6_mib_outnd);
ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
}
if (likely(idev != NULL))
in6_dev_put(idev);
}
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,
inc_opt ? ND_OPT_TARGET_LL_ADDR : 0,
ICMP6_MIB_OUTNEIGHBORADVERTISEMENTS);
}
void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
struct in6_addr *solicit,
struct in6_addr *daddr, struct in6_addr *saddr)
{
struct in6_addr addr_buf;
struct icmp6hdr icmp6h = {
.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
};
if (saddr == NULL) {
if (ipv6_get_lladdr(dev, &addr_buf,
(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
return;
saddr = &addr_buf;
}
__ndisc_send(dev, neigh, daddr, saddr,
&icmp6h, solicit,
!ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0,
ICMP6_MIB_OUTNEIGHBORSOLICITS);
}
void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
struct in6_addr *daddr)
{
struct icmp6hdr icmp6h = {
.icmp6_type = NDISC_ROUTER_SOLICITATION,
};
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) {
struct inet6_ifaddr *ifp = ipv6_get_ifaddr(saddr, dev, 1);
if (ifp) {
if (ifp->flags & IFA_F_OPTIMISTIC) {
send_sllao = 0;
}
in6_ifa_put(ifp);
} else {
send_sllao = 0;
}
}
#endif
__ndisc_send(dev, NULL, daddr, saddr,
&icmp6h, NULL,
send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0,
ICMP6_MIB_OUTROUTERSOLICITS);
}
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);
if (skb && ipv6_chk_addr(&ipv6_hdr(skb)->saddr, dev, 1))
saddr = &ipv6_hdr(skb)->saddr;
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: "
NIP6_FMT "\n",
__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)
{
struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
u8 *lladdr = NULL;
u32 ndoptlen = skb->tail - (skb->transport_header +
offsetof(struct nd_msg, opt));
struct ndisc_options ndopts;
struct net_device *dev = skb->dev;
struct inet6_ifaddr *ifp;
struct inet6_dev *idev = NULL;
struct neighbour *neigh;
struct pneigh_entry *pneigh = NULL;
int dad = ipv6_addr_any(saddr);
int inc;
int is_router;
if (ipv6_addr_is_multicast(&msg->target)) {
ND_PRINTK2(KERN_WARNING
"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)) {
ND_PRINTK2(KERN_WARNING
"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:
* If the IP source address is the unspecified address,
* there MUST NOT be source link-layer address option
* in the message.
*/
if (dad) {
ND_PRINTK2(KERN_WARNING
"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) {
if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
if (dad) {
if (dev->type == ARPHRD_IEEE802_TR) {
const unsigned char *sadr;
sadr = skb_mac_header(skb);
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);
goto out;
} 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))
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) ||
(idev->cnf.forwarding &&
(ipv6_devconf.proxy_ndp || idev->cnf.proxy_ndp) &&
(pneigh = pneigh_lookup(&nd_tbl,
&msg->target, dev, 0)) != NULL)) {
if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
skb->pkt_type != PACKET_HOST &&
inc != 0 &&
idev->nd_parms->proxy_delay != 0) {
/*
* for anycast or proxy,
* sender should delay its response
* by a random time between 0 and
* 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;
}
is_router = !!(pneigh ? pneigh->flags & NTF_ROUTER : idev->cnf.forwarding);
if (dad) {
struct in6_addr maddr;
ipv6_addr_all_nodes(&maddr);
ndisc_send_na(dev, NULL, &maddr, &msg->target,
is_router, 0, (ifp != NULL), 1);
goto out;
}
if (inc)
NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
else
NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
/*
* update / create cache entry
* for the source address
*/
neigh = __neigh_lookup(&nd_tbl, saddr, dev,
!inc || lladdr || !dev->addr_len);
if (neigh)
neigh_update(neigh, lladdr, NUD_STALE,
NEIGH_UPDATE_F_WEAK_OVERRIDE|
NEIGH_UPDATE_F_OVERRIDE);
if (neigh || !dev->hard_header) {
ndisc_send_na(dev, neigh, saddr, &msg->target,
is_router,
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)
{
struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
u8 *lladdr = NULL;
u32 ndoptlen = skb->tail - (skb->transport_header +
offsetof(struct nd_msg, opt));
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;
}
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;
/*
* 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) &&
ipv6_devconf.forwarding && ipv6_devconf.proxy_ndp &&
pneigh_lookup(&nd_tbl, &msg->target, dev, 0)) {
/* XXX: idev->cnf.prixy_ndp */
goto out;
}
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)
ip6_del_rt(rt);
}
out:
neigh_release(neigh);
}
}
static void ndisc_recv_rs(struct sk_buff *skb)
{
struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
struct neighbour *neigh;
struct inet6_dev *idev;
struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
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)
{
struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
struct neighbour *neigh = NULL;
struct inet6_dev *in6_dev;
struct rt6_info *rt = NULL;
int lifetime;
struct ndisc_options ndopts;
int optlen;
unsigned int pref = 0;
__u8 * opt = (__u8 *)(ra_msg + 1);