addrconf.c

linux 内核源代码

			} else {
				if (hiscore.attrs & IPV6_SADDR_SCORE_OIF)
					continue;
			}

			/* Rule 6: Prefer matching label */
			if (hiscore.rule < 6) {
				if (ipv6_saddr_label(&ifa_result->addr, hiscore.addr_type) == daddr_label)
					hiscore.attrs |= IPV6_SADDR_SCORE_LABEL;
				hiscore.rule++;
			}
			if (ipv6_saddr_label(&ifa->addr, score.addr_type) == daddr_label) {
				score.attrs |= IPV6_SADDR_SCORE_LABEL;
				if (!(hiscore.attrs & IPV6_SADDR_SCORE_LABEL)) {
					score.rule = 6;
					goto record_it;
				}
			} else {
				if (hiscore.attrs & IPV6_SADDR_SCORE_LABEL)
					continue;
			}

#ifdef CONFIG_IPV6_PRIVACY
			/* Rule 7: Prefer public address
			 * Note: prefer temprary address if use_tempaddr >= 2
			 */
			if (hiscore.rule < 7) {
				if ((!(ifa_result->flags & IFA_F_TEMPORARY)) ^
				    (ifa_result->idev->cnf.use_tempaddr >= 2))
					hiscore.attrs |= IPV6_SADDR_SCORE_PRIVACY;
				hiscore.rule++;
			}
			if ((!(ifa->flags & IFA_F_TEMPORARY)) ^
			    (ifa->idev->cnf.use_tempaddr >= 2)) {
				score.attrs |= IPV6_SADDR_SCORE_PRIVACY;
				if (!(hiscore.attrs & IPV6_SADDR_SCORE_PRIVACY)) {
					score.rule = 7;
					goto record_it;
				}
			} else {
				if (hiscore.attrs & IPV6_SADDR_SCORE_PRIVACY)
					continue;
			}
#else
			if (hiscore.rule < 7)
				hiscore.rule++;
#endif
			/* Rule 8: Use longest matching prefix */
			if (hiscore.rule < 8) {
				hiscore.matchlen = ipv6_addr_diff(&ifa_result->addr, daddr);
				hiscore.rule++;
			}
			score.matchlen = ipv6_addr_diff(&ifa->addr, daddr);
			if (score.matchlen > hiscore.matchlen) {
				score.rule = 8;
				goto record_it;
			}
#if 0
			else if (score.matchlen < hiscore.matchlen)
				continue;
#endif

			/* Final Rule: choose first available one */
			continue;
record_it:
			if (ifa_result)
				in6_ifa_put(ifa_result);
			in6_ifa_hold(ifa);
			ifa_result = ifa;
			hiscore = score;
		}
		read_unlock_bh(&idev->lock);
	}
	rcu_read_unlock();
	read_unlock(&dev_base_lock);

	if (!ifa_result)
		return -EADDRNOTAVAIL;

	ipv6_addr_copy(saddr, &ifa_result->addr);
	in6_ifa_put(ifa_result);
	return 0;
}


int ipv6_get_saddr(struct dst_entry *dst,
		   struct in6_addr *daddr, struct in6_addr *saddr)
{
	return ipv6_dev_get_saddr(dst ? ip6_dst_idev(dst)->dev : NULL, daddr, saddr);
}

EXPORT_SYMBOL(ipv6_get_saddr);

int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr,
		    unsigned char banned_flags)
{
	struct inet6_dev *idev;
	int err = -EADDRNOTAVAIL;

	rcu_read_lock();
	if ((idev = __in6_dev_get(dev)) != NULL) {
		struct inet6_ifaddr *ifp;

		read_lock_bh(&idev->lock);
		for (ifp=idev->addr_list; ifp; ifp=ifp->if_next) {
			if (ifp->scope == IFA_LINK && !(ifp->flags & banned_flags)) {
				ipv6_addr_copy(addr, &ifp->addr);
				err = 0;
				break;
			}
		}
		read_unlock_bh(&idev->lock);
	}
	rcu_read_unlock();
	return err;
}

static int ipv6_count_addresses(struct inet6_dev *idev)
{
	int cnt = 0;
	struct inet6_ifaddr *ifp;

	read_lock_bh(&idev->lock);
	for (ifp=idev->addr_list; ifp; ifp=ifp->if_next)
		cnt++;
	read_unlock_bh(&idev->lock);
	return cnt;
}

int ipv6_chk_addr(struct in6_addr *addr, struct net_device *dev, int strict)
{
	struct inet6_ifaddr * ifp;
	u8 hash = ipv6_addr_hash(addr);

	read_lock_bh(&addrconf_hash_lock);
	for(ifp = inet6_addr_lst[hash]; ifp; ifp=ifp->lst_next) {
		if (ipv6_addr_equal(&ifp->addr, addr) &&
		    !(ifp->flags&IFA_F_TENTATIVE)) {
			if (dev == NULL || ifp->idev->dev == dev ||
			    !(ifp->scope&(IFA_LINK|IFA_HOST) || strict))
				break;
		}
	}
	read_unlock_bh(&addrconf_hash_lock);
	return ifp != NULL;
}

EXPORT_SYMBOL(ipv6_chk_addr);

static
int ipv6_chk_same_addr(const struct in6_addr *addr, struct net_device *dev)
{
	struct inet6_ifaddr * ifp;
	u8 hash = ipv6_addr_hash(addr);

	for(ifp = inet6_addr_lst[hash]; ifp; ifp=ifp->lst_next) {
		if (ipv6_addr_equal(&ifp->addr, addr)) {
			if (dev == NULL || ifp->idev->dev == dev)
				break;
		}
	}
	return ifp != NULL;
}

struct inet6_ifaddr * ipv6_get_ifaddr(struct in6_addr *addr, struct net_device *dev, int strict)
{
	struct inet6_ifaddr * ifp;
	u8 hash = ipv6_addr_hash(addr);

	read_lock_bh(&addrconf_hash_lock);
	for(ifp = inet6_addr_lst[hash]; ifp; ifp=ifp->lst_next) {
		if (ipv6_addr_equal(&ifp->addr, addr)) {
			if (dev == NULL || ifp->idev->dev == dev ||
			    !(ifp->scope&(IFA_LINK|IFA_HOST) || strict)) {
				in6_ifa_hold(ifp);
				break;
			}
		}
	}
	read_unlock_bh(&addrconf_hash_lock);

	return ifp;
}

int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
{
	const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
	__be32 sk_rcv_saddr = inet_sk(sk)->rcv_saddr;
	__be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
	int sk_ipv6only = ipv6_only_sock(sk);
	int sk2_ipv6only = inet_v6_ipv6only(sk2);
	int addr_type = ipv6_addr_type(sk_rcv_saddr6);
	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;

	if (!sk2_rcv_saddr && !sk_ipv6only)
		return 1;

	if (addr_type2 == IPV6_ADDR_ANY &&
	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
		return 1;

	if (addr_type == IPV6_ADDR_ANY &&
	    !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
		return 1;

	if (sk2_rcv_saddr6 &&
	    ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
		return 1;

	if (addr_type == IPV6_ADDR_MAPPED &&
	    !sk2_ipv6only &&
	    (!sk2_rcv_saddr || !sk_rcv_saddr || sk_rcv_saddr == sk2_rcv_saddr))
		return 1;

	return 0;
}

/* Gets referenced address, destroys ifaddr */

static void addrconf_dad_stop(struct inet6_ifaddr *ifp)
{
	if (ifp->flags&IFA_F_PERMANENT) {
		spin_lock_bh(&ifp->lock);
		addrconf_del_timer(ifp);
		ifp->flags |= IFA_F_TENTATIVE;
		spin_unlock_bh(&ifp->lock);
		in6_ifa_put(ifp);
#ifdef CONFIG_IPV6_PRIVACY
	} else if (ifp->flags&IFA_F_TEMPORARY) {
		struct inet6_ifaddr *ifpub;
		spin_lock_bh(&ifp->lock);
		ifpub = ifp->ifpub;
		if (ifpub) {
			in6_ifa_hold(ifpub);
			spin_unlock_bh(&ifp->lock);
			ipv6_create_tempaddr(ifpub, ifp);
			in6_ifa_put(ifpub);
		} else {
			spin_unlock_bh(&ifp->lock);
		}
		ipv6_del_addr(ifp);
#endif
	} else
		ipv6_del_addr(ifp);
}

void addrconf_dad_failure(struct inet6_ifaddr *ifp)
{
	if (net_ratelimit())
		printk(KERN_INFO "%s: duplicate address detected!\n", ifp->idev->dev->name);
	addrconf_dad_stop(ifp);
}

/* Join to solicited addr multicast group. */

void addrconf_join_solict(struct net_device *dev, struct in6_addr *addr)
{
	struct in6_addr maddr;

	if (dev->flags&(IFF_LOOPBACK|IFF_NOARP))
		return;

	addrconf_addr_solict_mult(addr, &maddr);
	ipv6_dev_mc_inc(dev, &maddr);
}

void addrconf_leave_solict(struct inet6_dev *idev, struct in6_addr *addr)
{
	struct in6_addr maddr;

	if (idev->dev->flags&(IFF_LOOPBACK|IFF_NOARP))
		return;

	addrconf_addr_solict_mult(addr, &maddr);
	__ipv6_dev_mc_dec(idev, &maddr);
}

static void addrconf_join_anycast(struct inet6_ifaddr *ifp)
{
	struct in6_addr addr;
	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
	if (ipv6_addr_any(&addr))
		return;
	ipv6_dev_ac_inc(ifp->idev->dev, &addr);
}

static void addrconf_leave_anycast(struct inet6_ifaddr *ifp)
{
	struct in6_addr addr;
	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
	if (ipv6_addr_any(&addr))
		return;
	__ipv6_dev_ac_dec(ifp->idev, &addr);
}

static int addrconf_ifid_eui48(u8 *eui, struct net_device *dev)
{
	if (dev->addr_len != ETH_ALEN)
		return -1;
	memcpy(eui, dev->dev_addr, 3);
	memcpy(eui + 5, dev->dev_addr + 3, 3);

	/*
	 * The zSeries OSA network cards can be shared among various
	 * OS instances, but the OSA cards have only one MAC address.
	 * This leads to duplicate address conflicts in conjunction
	 * with IPv6 if more than one instance uses the same card.
	 *
	 * The driver for these cards can deliver a unique 16-bit
	 * identifier for each instance sharing the same card.  It is
	 * placed instead of 0xFFFE in the interface identifier.  The
	 * "u" bit of the interface identifier is not inverted in this
	 * case.  Hence the resulting interface identifier has local
	 * scope according to RFC2373.
	 */
	if (dev->dev_id) {
		eui[3] = (dev->dev_id >> 8) & 0xFF;
		eui[4] = dev->dev_id & 0xFF;
	} else {
		eui[3] = 0xFF;
		eui[4] = 0xFE;
		eui[0] ^= 2;
	}
	return 0;
}

static int addrconf_ifid_arcnet(u8 *eui, struct net_device *dev)
{
	/* XXX: inherit EUI-64 from other interface -- yoshfuji */
	if (dev->addr_len != ARCNET_ALEN)
		return -1;
	memset(eui, 0, 7);
	eui[7] = *(u8*)dev->dev_addr;
	return 0;
}

static int addrconf_ifid_infiniband(u8 *eui, struct net_device *dev)
{
	if (dev->addr_len != INFINIBAND_ALEN)
		return -1;
	memcpy(eui, dev->dev_addr + 12, 8);
	eui[0] |= 2;
	return 0;
}

static int ipv6_generate_eui64(u8 *eui, struct net_device *dev)
{
	switch (dev->type) {
	case ARPHRD_ETHER:
	case ARPHRD_FDDI:
	case ARPHRD_IEEE802_TR:
		return addrconf_ifid_eui48(eui, dev);
	case ARPHRD_ARCNET:
		return addrconf_ifid_arcnet(eui, dev);
	case ARPHRD_INFINIBAND:
		return addrconf_ifid_infiniband(eui, dev);
	}
	return -1;
}

static int ipv6_inherit_eui64(u8 *eui, struct inet6_dev *idev)
{
	int err = -1;
	struct inet6_ifaddr *ifp;

	read_lock_bh(&idev->lock);
	for (ifp=idev->addr_list; ifp; ifp=ifp->if_next) {
		if (ifp->scope == IFA_LINK && !(ifp->flags&IFA_F_TENTATIVE)) {
			memcpy(eui, ifp->addr.s6_addr+8, 8);
			err = 0;
			break;
		}
	}
	read_unlock_bh(&idev->lock);
	return err;
}

#ifdef CONFIG_IPV6_PRIVACY
/* (re)generation of randomized interface identifier (RFC 3041 3.2, 3.5) */
static int __ipv6_regen_rndid(struct inet6_dev *idev)
{
regen:
	get_random_bytes(idev->rndid, sizeof(idev->rndid));
	idev->rndid[0] &= ~0x02;

	/*
	 * <draft-ietf-ipngwg-temp-addresses-v2-00.txt>:
	 * check if generated address is not inappropriate
	 *
	 *  - Reserved subnet anycast (RFC 2526)
	 *	11111101 11....11 1xxxxxxx
	 *  - ISATAP (draft-ietf-ngtrans-isatap-13.txt) 5.1
	 *	00-00-5E-FE-xx-xx-xx-xx
	 *  - value 0
	 *  - XXX: already assigned to an address on the device
	 */
	if (idev->rndid[0] == 0xfd &&
	    (idev->rndid[1]&idev->rndid[2]&idev->rndid[3]&idev->rndid[4]&idev->rndid[5]&idev->rndid[6]) == 0xff &&
	    (idev->rndid[7]&0x80))
		goto regen;
	if ((idev->rndid[0]|idev->rndid[1]) == 0) {
		if (idev->rndid[2] == 0x5e && idev->rndid[3] == 0xfe)
			goto regen;
		if ((idev->rndid[2]|idev->rndid[3]|idev->rndid[4]|idev->rndid[5]|idev->rndid[6]|idev->rndid[7]) == 0x00)
			goto regen;
	}

	return 0;
}

static void ipv6_regen_rndid(unsigned long data)
{
	struct inet6_dev *idev = (struct inet6_dev *) data;
	unsigned long expires;

	rcu_read_lock_bh();
	write_lock_bh(&idev->lock);

	if (idev->dead)
		goto out;

	if (__ipv6_regen_rndid(idev) < 0)
		goto out;

	expires = jiffies +
		idev->cnf.temp_prefered_lft * HZ -
		idev->cnf.regen_max_retry * idev->cnf.dad_transmits * idev->nd_parms->retrans_time - desync_factor;
	if (time_before(expires, jiffies)) {
		printk(KERN_WARNING
			"ipv6_regen_rndid(): too short regeneration interval; timer disabled for %s.\n",
			idev->dev->name);
		goto out;
	}

	if (!mod_timer(&idev->regen_timer, expires))
		in6_dev_hold(idev);

out:
	write_unlock_bh(&idev->lock);
	rcu_read_unlock_bh();
	in6_dev_put(idev);
}

static int __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr) {
	int ret = 0;

	if (tmpaddr && memcmp(idev->rndid, &tmpaddr->s6_addr[8], 8) == 0)
		ret = __ipv6_regen_rndid(idev);
	return ret;
}
#endif

/*
 *	Add prefix route.
 */

static void
addrconf_prefix_route(struct in6_addr *pfx, int plen, struct net_device *dev,
		      unsigned long expires, u32 flags)
{
	struct fib6_config cfg = {
		.fc_table = RT6_TABLE_PREFIX,
		.fc_metric = IP6_RT_PRIO_ADDRCONF,
		.fc_ifindex = dev->ifindex,
		.fc_expires = expires,
		.fc_dst_len = plen,
		.fc_flags = RTF_UP | flags,
	};

	ipv6_addr_copy(&cfg.fc_dst, pfx);

	/* Prevent useless cloning on PtP SIT.
	   This thing is done here expecting that the whole
	   class of non-broadcast devices need not cloning.
	 */
#if defined(CONFIG_IPV6_SIT) || defined(CONFIG_IPV6_SIT_MODULE)
	if (dev->type == ARPHRD_SIT && (dev->flags & IFF_POINTOPOINT))
		cfg.fc_flags |= RTF_NONEXTHOP;
#endif

	ip6_route_add(&cfg);
}

/* Create "default" multicast route to the interface */

static void addrconf_add_mroute(struct net_device *dev)
{
	struct fib6_config cfg = {
		.fc_table = RT6_TABLE_LOCAL,
		.fc_metric = IP6_RT_PRIO_ADDRCONF,
		.fc_ifindex = dev->ifindex,
		.fc_dst_len = 8,
		.fc_flags = RTF_UP,
	};

	ipv6_addr_set(&cfg.fc_dst, htonl(0xFF000000), 0, 0, 0);

	ip6_route_add(&cfg);
}

#if defined(CONFIG_IPV6_SIT) || defined(CONFIG_IPV6_SIT_MODULE)
static void sit_route_add(struct net_device *dev)
{
	struct fib6_config cfg = {
		.fc_table = RT6_TABLE_MAIN,
		.fc_metric = IP6_RT_PRIO_ADDRCONF,
		.fc_ifindex = dev->ifindex,
		.fc_dst_len = 96,
		.fc_flags = RTF_UP | RTF_NONEXTHOP,
	};

	/* prefix length - 96 bits "::d.d.d.d" */
	ip6_route_add(&cfg);
}
#endif

static void addrconf_add_lroute(struct net_device *dev)
{
	struct in6_addr addr;

	ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
	addrconf_prefix_route(&addr, 64, dev, 0, 0);
}

static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
{
	struct inet6_dev *idev;

	ASSERT_RTNL();

	if ((idev = ipv6_find_idev(dev)) == NULL)
		return NULL;

	/* Add default multicast route */
	addrconf_add_mroute(dev);

	/* Add link local route */
	addrconf_add_lroute(dev);
	return idev;