addrconf.c

linux 内核源代码

}

void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
{
	struct prefix_info *pinfo;
	__u32 valid_lft;
	__u32 prefered_lft;
	int addr_type;
	unsigned long rt_expires;
	struct inet6_dev *in6_dev;

	pinfo = (struct prefix_info *) opt;

	if (len < sizeof(struct prefix_info)) {
		ADBG(("addrconf: prefix option too short\n"));
		return;
	}

	/*
	 *	Validation checks ([ADDRCONF], page 19)
	 */

	addr_type = ipv6_addr_type(&pinfo->prefix);

	if (addr_type & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL))
		return;

	valid_lft = ntohl(pinfo->valid);
	prefered_lft = ntohl(pinfo->prefered);

	if (prefered_lft > valid_lft) {
		if (net_ratelimit())
			printk(KERN_WARNING "addrconf: prefix option has invalid lifetime\n");
		return;
	}

	in6_dev = in6_dev_get(dev);

	if (in6_dev == NULL) {
		if (net_ratelimit())
			printk(KERN_DEBUG "addrconf: device %s not configured\n", dev->name);
		return;
	}

	/*
	 *	Two things going on here:
	 *	1) Add routes for on-link prefixes
	 *	2) Configure prefixes with the auto flag set
	 */

	/* Avoid arithmetic overflow. Really, we could
	   save rt_expires in seconds, likely valid_lft,
	   but it would require division in fib gc, that it
	   not good.
	 */
	if (valid_lft >= 0x7FFFFFFF/HZ)
		rt_expires = 0x7FFFFFFF - (0x7FFFFFFF % HZ);
	else
		rt_expires = valid_lft * HZ;

	/*
	 * We convert this (in jiffies) to clock_t later.
	 * Avoid arithmetic overflow there as well.
	 * Overflow can happen only if HZ < USER_HZ.
	 */
	if (HZ < USER_HZ && rt_expires > 0x7FFFFFFF / USER_HZ)
		rt_expires = 0x7FFFFFFF / USER_HZ;

	if (pinfo->onlink) {
		struct rt6_info *rt;
		rt = rt6_lookup(&pinfo->prefix, NULL, dev->ifindex, 1);

		if (rt && ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0)) {
			if (rt->rt6i_flags&RTF_EXPIRES) {
				if (valid_lft == 0) {
					ip6_del_rt(rt);
					rt = NULL;
				} else {
					rt->rt6i_expires = jiffies + rt_expires;
				}
			}
		} else if (valid_lft) {
			addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
					      dev, jiffies_to_clock_t(rt_expires), RTF_ADDRCONF|RTF_EXPIRES|RTF_PREFIX_RT);
		}
		if (rt)
			dst_release(&rt->u.dst);
	}

	/* Try to figure out our local address for this prefix */

	if (pinfo->autoconf && in6_dev->cnf.autoconf) {
		struct inet6_ifaddr * ifp;
		struct in6_addr addr;
		int create = 0, update_lft = 0;

		if (pinfo->prefix_len == 64) {
			memcpy(&addr, &pinfo->prefix, 8);
			if (ipv6_generate_eui64(addr.s6_addr + 8, dev) &&
			    ipv6_inherit_eui64(addr.s6_addr + 8, in6_dev)) {
				in6_dev_put(in6_dev);
				return;
			}
			goto ok;
		}
		if (net_ratelimit())
			printk(KERN_DEBUG "IPv6 addrconf: prefix with wrong length %d\n",
			       pinfo->prefix_len);
		in6_dev_put(in6_dev);
		return;

ok:

		ifp = ipv6_get_ifaddr(&addr, dev, 1);

		if (ifp == NULL && valid_lft) {
			int max_addresses = in6_dev->cnf.max_addresses;
			u32 addr_flags = 0;

#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
			if (in6_dev->cnf.optimistic_dad &&
			    !ipv6_devconf.forwarding)
				addr_flags = IFA_F_OPTIMISTIC;
#endif

			/* Do not allow to create too much of autoconfigured
			 * addresses; this would be too easy way to crash kernel.
			 */
			if (!max_addresses ||
			    ipv6_count_addresses(in6_dev) < max_addresses)
				ifp = ipv6_add_addr(in6_dev, &addr, pinfo->prefix_len,
						    addr_type&IPV6_ADDR_SCOPE_MASK,
						    addr_flags);

			if (!ifp || IS_ERR(ifp)) {
				in6_dev_put(in6_dev);
				return;
			}

			update_lft = create = 1;
			ifp->cstamp = jiffies;
			addrconf_dad_start(ifp, RTF_ADDRCONF|RTF_PREFIX_RT);
		}

		if (ifp) {
			int flags;
			unsigned long now;
#ifdef CONFIG_IPV6_PRIVACY
			struct inet6_ifaddr *ift;
#endif
			u32 stored_lft;

			/* update lifetime (RFC2462 5.5.3 e) */
			spin_lock(&ifp->lock);
			now = jiffies;
			if (ifp->valid_lft > (now - ifp->tstamp) / HZ)
				stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ;
			else
				stored_lft = 0;
			if (!update_lft && stored_lft) {
				if (valid_lft > MIN_VALID_LIFETIME ||
				    valid_lft > stored_lft)
					update_lft = 1;
				else if (stored_lft <= MIN_VALID_LIFETIME) {
					/* valid_lft <= stored_lft is always true */
					/* XXX: IPsec */
					update_lft = 0;
				} else {
					valid_lft = MIN_VALID_LIFETIME;
					if (valid_lft < prefered_lft)
						prefered_lft = valid_lft;
					update_lft = 1;
				}
			}

			if (update_lft) {
				ifp->valid_lft = valid_lft;
				ifp->prefered_lft = prefered_lft;
				ifp->tstamp = now;
				flags = ifp->flags;
				ifp->flags &= ~IFA_F_DEPRECATED;
				spin_unlock(&ifp->lock);

				if (!(flags&IFA_F_TENTATIVE))
					ipv6_ifa_notify(0, ifp);
			} else
				spin_unlock(&ifp->lock);

#ifdef CONFIG_IPV6_PRIVACY
			read_lock_bh(&in6_dev->lock);
			/* update all temporary addresses in the list */
			for (ift=in6_dev->tempaddr_list; ift; ift=ift->tmp_next) {
				/*
				 * When adjusting the lifetimes of an existing
				 * temporary address, only lower the lifetimes.
				 * Implementations must not increase the
				 * lifetimes of an existing temporary address
				 * when processing a Prefix Information Option.
				 */
				spin_lock(&ift->lock);
				flags = ift->flags;
				if (ift->valid_lft > valid_lft &&
				    ift->valid_lft - valid_lft > (jiffies - ift->tstamp) / HZ)
					ift->valid_lft = valid_lft + (jiffies - ift->tstamp) / HZ;
				if (ift->prefered_lft > prefered_lft &&
				    ift->prefered_lft - prefered_lft > (jiffies - ift->tstamp) / HZ)
					ift->prefered_lft = prefered_lft + (jiffies - ift->tstamp) / HZ;
				spin_unlock(&ift->lock);
				if (!(flags&IFA_F_TENTATIVE))
					ipv6_ifa_notify(0, ift);
			}

			if (create && in6_dev->cnf.use_tempaddr > 0) {
				/*
				 * When a new public address is created as described in [ADDRCONF],
				 * also create a new temporary address.
				 */
				read_unlock_bh(&in6_dev->lock);
				ipv6_create_tempaddr(ifp, NULL);
			} else {
				read_unlock_bh(&in6_dev->lock);
			}
#endif
			in6_ifa_put(ifp);
			addrconf_verify(0);
		}
	}
	inet6_prefix_notify(RTM_NEWPREFIX, in6_dev, pinfo);
	in6_dev_put(in6_dev);
}

/*
 *	Set destination address.
 *	Special case for SIT interfaces where we create a new "virtual"
 *	device.
 */
int addrconf_set_dstaddr(void __user *arg)
{
	struct in6_ifreq ireq;
	struct net_device *dev;
	int err = -EINVAL;

	rtnl_lock();

	err = -EFAULT;
	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
		goto err_exit;

	dev = __dev_get_by_index(&init_net, ireq.ifr6_ifindex);

	err = -ENODEV;
	if (dev == NULL)
		goto err_exit;

#if defined(CONFIG_IPV6_SIT) || defined(CONFIG_IPV6_SIT_MODULE)
	if (dev->type == ARPHRD_SIT) {
		struct ifreq ifr;
		mm_segment_t	oldfs;
		struct ip_tunnel_parm p;

		err = -EADDRNOTAVAIL;
		if (!(ipv6_addr_type(&ireq.ifr6_addr) & IPV6_ADDR_COMPATv4))
			goto err_exit;

		memset(&p, 0, sizeof(p));
		p.iph.daddr = ireq.ifr6_addr.s6_addr32[3];
		p.iph.saddr = 0;
		p.iph.version = 4;
		p.iph.ihl = 5;
		p.iph.protocol = IPPROTO_IPV6;
		p.iph.ttl = 64;
		ifr.ifr_ifru.ifru_data = (void __user *)&p;

		oldfs = get_fs(); set_fs(KERNEL_DS);
		err = dev->do_ioctl(dev, &ifr, SIOCADDTUNNEL);
		set_fs(oldfs);

		if (err == 0) {
			err = -ENOBUFS;
			if ((dev = __dev_get_by_name(&init_net, p.name)) == NULL)
				goto err_exit;
			err = dev_open(dev);
		}
	}
#endif

err_exit:
	rtnl_unlock();
	return err;
}

/*
 *	Manual configuration of address on an interface
 */
static int inet6_addr_add(int ifindex, struct in6_addr *pfx, int plen,
			  __u8 ifa_flags, __u32 prefered_lft, __u32 valid_lft)
{
	struct inet6_ifaddr *ifp;
	struct inet6_dev *idev;
	struct net_device *dev;
	int scope;
	u32 flags = RTF_EXPIRES;

	ASSERT_RTNL();

	/* check the lifetime */
	if (!valid_lft || prefered_lft > valid_lft)
		return -EINVAL;

	if ((dev = __dev_get_by_index(&init_net, ifindex)) == NULL)
		return -ENODEV;

	if ((idev = addrconf_add_dev(dev)) == NULL)
		return -ENOBUFS;

	scope = ipv6_addr_scope(pfx);

	if (valid_lft == INFINITY_LIFE_TIME) {
		ifa_flags |= IFA_F_PERMANENT;
		flags = 0;
	} else if (valid_lft >= 0x7FFFFFFF/HZ)
		valid_lft = 0x7FFFFFFF/HZ;

	if (prefered_lft == 0)
		ifa_flags |= IFA_F_DEPRECATED;
	else if ((prefered_lft >= 0x7FFFFFFF/HZ) &&
		 (prefered_lft != INFINITY_LIFE_TIME))
		prefered_lft = 0x7FFFFFFF/HZ;

	ifp = ipv6_add_addr(idev, pfx, plen, scope, ifa_flags);

	if (!IS_ERR(ifp)) {
		spin_lock_bh(&ifp->lock);
		ifp->valid_lft = valid_lft;
		ifp->prefered_lft = prefered_lft;
		ifp->tstamp = jiffies;
		spin_unlock_bh(&ifp->lock);

		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev,
				      jiffies_to_clock_t(valid_lft * HZ), flags);
		/*
		 * Note that section 3.1 of RFC 4429 indicates
		 * that the Optimistic flag should not be set for
		 * manually configured addresses
		 */
		addrconf_dad_start(ifp, 0);
		in6_ifa_put(ifp);
		addrconf_verify(0);
		return 0;
	}

	return PTR_ERR(ifp);
}

static int inet6_addr_del(int ifindex, struct in6_addr *pfx, int plen)
{
	struct inet6_ifaddr *ifp;
	struct inet6_dev *idev;
	struct net_device *dev;

	if ((dev = __dev_get_by_index(&init_net, ifindex)) == NULL)
		return -ENODEV;

	if ((idev = __in6_dev_get(dev)) == NULL)
		return -ENXIO;

	read_lock_bh(&idev->lock);
	for (ifp = idev->addr_list; ifp; ifp=ifp->if_next) {
		if (ifp->prefix_len == plen &&
		    ipv6_addr_equal(pfx, &ifp->addr)) {
			in6_ifa_hold(ifp);
			read_unlock_bh(&idev->lock);

			ipv6_del_addr(ifp);

			/* If the last address is deleted administratively,
			   disable IPv6 on this interface.
			 */
			if (idev->addr_list == NULL)
				addrconf_ifdown(idev->dev, 1);
			return 0;
		}
	}
	read_unlock_bh(&idev->lock);
	return -EADDRNOTAVAIL;
}


int addrconf_add_ifaddr(void __user *arg)
{
	struct in6_ifreq ireq;
	int err;

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
		return -EFAULT;

	rtnl_lock();
	err = inet6_addr_add(ireq.ifr6_ifindex, &ireq.ifr6_addr, ireq.ifr6_prefixlen,
			     IFA_F_PERMANENT, INFINITY_LIFE_TIME, INFINITY_LIFE_TIME);
	rtnl_unlock();
	return err;
}

int addrconf_del_ifaddr(void __user *arg)
{
	struct in6_ifreq ireq;
	int err;

	if (!capable(CAP_NET_ADMIN))
		return -EPERM;

	if (copy_from_user(&ireq, arg, sizeof(struct in6_ifreq)))
		return -EFAULT;

	rtnl_lock();
	err = inet6_addr_del(ireq.ifr6_ifindex, &ireq.ifr6_addr, ireq.ifr6_prefixlen);
	rtnl_unlock();
	return err;
}

#if defined(CONFIG_IPV6_SIT) || defined(CONFIG_IPV6_SIT_MODULE)
static void sit_add_v4_addrs(struct inet6_dev *idev)
{
	struct inet6_ifaddr * ifp;
	struct in6_addr addr;
	struct net_device *dev;
	int scope;

	ASSERT_RTNL();

	memset(&addr, 0, sizeof(struct in6_addr));
	memcpy(&addr.s6_addr32[3], idev->dev->dev_addr, 4);

	if (idev->dev->flags&IFF_POINTOPOINT) {
		addr.s6_addr32[0] = htonl(0xfe800000);
		scope = IFA_LINK;
	} else {
		scope = IPV6_ADDR_COMPATv4;
	}

	if (addr.s6_addr32[3]) {
		ifp = ipv6_add_addr(idev, &addr, 128, scope, IFA_F_PERMANENT);
		if (!IS_ERR(ifp)) {
			spin_lock_bh(&ifp->lock);
			ifp->flags &= ~IFA_F_TENTATIVE;
			spin_unlock_bh(&ifp->lock);
			ipv6_ifa_notify(RTM_NEWADDR, ifp);
			in6_ifa_put(ifp);
		}
		return;
	}

	for_each_netdev(&init_net, dev) {
		struct in_device * in_dev = __in_dev_get_rtnl(dev);
		if (in_dev && (dev->flags & IFF_UP)) {
			struct in_ifaddr * ifa;

			int flag = scope;

			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
				int plen;

				addr.s6_addr32[3] = ifa->ifa_local;

				if (ifa->ifa_scope == RT_SCOPE_LINK)
					continue;
				if (ifa->ifa_scope >= RT_SCOPE_HOST) {
					if (idev->dev->flags&IFF_POINTOPOINT)
						continue;
					flag |= IFA_HOST;
				}
				if (idev->dev->flags&IFF_POINTOPOINT)
					plen = 64;
				else
					plen = 96;

				ifp = ipv6_add_addr(idev, &addr, plen, flag,
						    IFA_F_PERMANENT);
				if (!IS_ERR(ifp)) {
					spin_lock_bh(&ifp->lock);
					ifp->flags &= ~IFA_F_TENTATIVE;
					spin_unlock_bh(&ifp->lock);
					ipv6_ifa_notify(RTM_NEWADDR, ifp);
					in6_ifa_put(ifp);
				}
			}
		}
	}
}
#endif

static void init_loopback(struct net_device *dev)
{
	struct inet6_dev  *idev;
	struct inet6_ifaddr * ifp;

	/* ::1 */

	ASSERT_RTNL();

	if ((idev = ipv6_find_idev(dev)) == NULL) {
		printk(KERN_DEBUG "init loopback: add_dev failed\n");
		return;
	}

	ifp = ipv6_add_addr(idev, &in6addr_loopback, 128, IFA_HOST, IFA_F_PERMANENT);
	if (!IS_ERR(ifp)) {
		spin_lock_bh(&ifp->lock);
		ifp->flags &= ~IFA_F_TENTATIVE;
		spin_unlock_bh(&ifp->lock);
		ipv6_ifa_notify(RTM_NEWADDR, ifp);
		in6_ifa_put(ifp);
	}
}

static void addrconf_add_linklocal(struct inet6_dev *idev, struct in6_addr *addr)
{
	struct inet6_ifaddr * ifp;
	u32 addr_flags = IFA_F_PERMANENT;

#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
	if (idev->cnf.optimistic_dad &&
	    !ipv6_devconf.forwarding)
		addr_flags |= IFA_F_OPTIMISTIC;
#endif


	ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, addr_flags);
	if (!IS_ERR(ifp)) {
		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, idev->dev, 0, 0);
		addrconf_dad_start(ifp, 0);
		in6_ifa_put(ifp);
	}
}

static void addrconf_dev_config(struct net_device *dev)
{