addrconf.c

ipv6地址转换器

}

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

	ipv6_addr_set(&addr,  __constant_htonl(0xFE800000), 0, 0, 0);
	addrconf_prefix_route(&addr, 10, dev, 0, RTF_ADDRCONF);
}

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

	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;
}

void addrconf_prefix_rcv(struct device *dev, u8 *opt, int len)
{
	struct prefix_info *pinfo;
	struct rt6_info *rt;
	__u32 valid_lft;
	__u32 prefered_lft;
	int addr_type;
	unsigned long rt_expires;
	struct inet6_dev *in6_dev = ipv6_get_idev(dev);

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

	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) {
		printk(KERN_WARNING "addrconf: prefix option has invalid lifetime\n");
		return;
	}

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

	/* Avoid arithemtic 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 = 0;
	else
		rt_expires = jiffies + valid_lft * HZ;

	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 (pinfo->onlink == 0 || valid_lft == 0) {
				ip6_del_rt(rt);
			} else {
				rt->rt6i_expires = rt_expires;
			}
		}
	} else if (pinfo->onlink && valid_lft) {
		addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
				      dev, rt_expires, RTF_ADDRCONF|RTF_EXPIRES);
	}
	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 plen;

		plen = pinfo->prefix_len >> 3;

#ifdef CONFIG_IPV6_EUI64
		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))
				return;
			goto ok;
		}
#endif
#ifndef CONFIG_IPV6_NO_PB
		if (pinfo->prefix_len == ((sizeof(struct in6_addr) - dev->addr_len)<<3)) {
			memcpy(&addr, &pinfo->prefix, plen);
			memcpy(addr.s6_addr + plen, dev->dev_addr,
			       dev->addr_len);
			goto ok;
		}
#endif
		printk(KERN_DEBUG "IPv6 addrconf: prefix with wrong length %d\n", pinfo->prefix_len);
		return;

ok:
		ifp = ipv6_chk_addr(&addr, dev, 1);

		if ((ifp == NULL || (ifp->flags&ADDR_INVALID)) && valid_lft) {

			if (ifp == NULL)
				ifp = ipv6_add_addr(in6_dev, &addr, addr_type & IPV6_ADDR_SCOPE_MASK);

			if (ifp == NULL)
				return;

			ifp->prefix_len = pinfo->prefix_len;

			addrconf_dad_start(ifp);
		}

		if (ifp && valid_lft == 0) {
			ipv6_del_addr(ifp);
			ifp = NULL;
		}

		if (ifp) {
			int event = 0;
			ifp->valid_lft = valid_lft;
			ifp->prefered_lft = prefered_lft;
			ifp->tstamp = jiffies;
			if (ifp->flags & ADDR_INVALID)
				event = RTM_NEWADDR;
			ifp->flags &= ~(ADDR_DEPRECATED|ADDR_INVALID);
			ipv6_ifa_notify(event, ifp);
		}
	}
}

/*
 *	Set destination address.
 *	Special case for SIT interfaces where we create a new "virtual"
 *	device.
 */
int addrconf_set_dstaddr(void *arg)
{
	struct in6_ifreq ireq;
	struct 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(ireq.ifr6_ifindex);

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

	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*)&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(p.name)) == NULL)
				goto err_exit;
			err = dev_open(dev);
		}
	}

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)
{
	struct inet6_ifaddr *ifp;
	struct inet6_dev *idev;
	struct device *dev;
	int scope;
	
	if ((dev = dev_get_by_index(ifindex)) == NULL)
		return -ENODEV;
	
	if (!(dev->flags&IFF_UP))
		return -ENETDOWN;

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

	scope = ipv6_addr_scope(pfx);

	addrconf_lock();
	if ((ifp = ipv6_add_addr(idev, pfx, scope)) != NULL) {
		ifp->prefix_len = plen;
		ifp->flags |= ADDR_PERMANENT;
		addrconf_dad_start(ifp);
		addrconf_unlock();
		return 0;
	}
	addrconf_unlock();

	return -ENOBUFS;
}

static int inet6_addr_del(int ifindex, struct in6_addr *pfx, int plen)
{
	struct inet6_ifaddr *ifp;
	struct inet6_dev *idev;
	struct device *dev;
	
	if ((dev = dev_get_by_index(ifindex)) == NULL)
		return -ENODEV;

	if ((idev = ipv6_get_idev(dev)) == NULL)
		return -ENXIO;

	start_bh_atomic();
	for (ifp = idev->addr_list; ifp; ifp=ifp->if_next) {
		if (ifp->prefix_len == plen &&
		    (!memcmp(pfx, &ifp->addr, sizeof(struct in6_addr)))) {
			ipv6_del_addr(ifp);
			end_bh_atomic();

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


int addrconf_add_ifaddr(void *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);
	rtnl_unlock();
	return err;
}

int addrconf_del_ifaddr(void *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;
}

static void sit_add_v4_addrs(struct inet6_dev *idev)
{
	struct inet6_ifaddr * ifp;
	struct in6_addr addr;
	struct device *dev;
	int scope;

	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] = __constant_htonl(0xfe800000);
		scope = IFA_LINK;
	} else {
		scope = IPV6_ADDR_COMPATv4;
	}

	if (addr.s6_addr32[3]) {
		addrconf_lock();
		ifp = ipv6_add_addr(idev, &addr, scope);
		if (ifp) {
			ifp->flags |= ADDR_PERMANENT;
			ifp->prefix_len = 128;
			ipv6_ifa_notify(RTM_NEWADDR, ifp);
		}
		addrconf_unlock();
		return;
	}

        for (dev = dev_base; dev != NULL; dev = dev->next) {
		if (dev->ip_ptr && (dev->flags & IFF_UP)) {
			struct in_device * in_dev = dev->ip_ptr;
			struct in_ifaddr * ifa;

			int flag = scope;

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

				addrconf_lock();
				ifp = ipv6_add_addr(idev, &addr, flag);
				if (ifp) {
					if (idev->dev->flags&IFF_POINTOPOINT)
						ifp->prefix_len = 10;
					else
						ifp->prefix_len = 96;
					ifp->flags |= ADDR_PERMANENT;
					ipv6_ifa_notify(RTM_NEWADDR, ifp);
				}
				addrconf_unlock();
			}
		}
        }
}

static void init_loopback(struct device *dev)
{
	struct in6_addr addr;
	struct inet6_dev  *idev;
	struct inet6_ifaddr * ifp;

	/* ::1 */

	memset(&addr, 0, sizeof(struct in6_addr));
	addr.s6_addr[15] = 1;

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

	addrconf_lock();
	ifp = ipv6_add_addr(idev, &addr, IFA_HOST);

	if (ifp) {
		ifp->flags |= ADDR_PERMANENT;
		ifp->prefix_len = 128;
		ipv6_ifa_notify(RTM_NEWADDR, ifp);
	}
	addrconf_unlock();
}

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

	addrconf_lock();
	ifp = ipv6_add_addr(idev, addr, IFA_LINK);
	if (ifp) {
		ifp->flags = ADDR_PERMANENT;
		ifp->prefix_len = 10;
		addrconf_dad_start(ifp);
	}
	addrconf_unlock();
}

static void addrconf_dev_config(struct device *dev)
{
	struct in6_addr addr;
	struct inet6_dev    * idev;

	if (dev->type != ARPHRD_ETHER) {
		/* Alas, we support only Ethernet autoconfiguration. */
		return;
	}

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

#ifdef CONFIG_IPV6_EUI64
	memset(&addr, 0, sizeof(struct in6_addr));

	addr.s6_addr[0] = 0xFE;
	addr.s6_addr[1] = 0x80;

	if (ipv6_generate_eui64(addr.s6_addr + 8, dev) == 0)
		addrconf_add_linklocal(idev, &addr);
#endif

#ifndef CONFIG_IPV6_NO_PB
	memset(&addr, 0, sizeof(struct in6_addr));

	addr.s6_addr[0] = 0xFE;
	addr.s6_addr[1] = 0x80;

	memcpy(addr.s6_addr + (sizeof(struct in6_addr) - dev->addr_len), 
	       dev->dev_addr, dev->addr_len);
	addrconf_add_linklocal(idev, &addr);
#endif
}

static void addrconf_sit_config(struct device *dev)
{
	struct inet6_dev *idev;

	/* 
	 * Configure the tunnel with one of our IPv4 
	 * addresses... we should configure all of 
	 * our v4 addrs in the tunnel
	 */

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

	sit_add_v4_addrs(idev);

	if (dev->flags&IFF_POINTOPOINT) {
		addrconf_add_mroute(dev);
		addrconf_add_lroute(dev);
	} else
		sit_route_add(dev);
}


int addrconf_notify(struct notifier_block *this, unsigned long event, 
		    void * data)
{
	struct device *dev;

	dev = (struct device *) data;

	switch(event) {
	case NETDEV_UP:
		switch(dev->type) {
		case ARPHRD_SIT:
			addrconf_sit_config(dev);
			break;

		case ARPHRD_LOOPBACK:
			init_loopback(dev);
			break;

		default:
			addrconf_dev_config(dev);
			break;
		};

#ifdef CONFIG_IPV6_NETLINK
		rt6_sndmsg(RTMSG_NEWDEVICE, NULL, NULL, NULL, dev, 0, 0, 0, 0);
#endif
		break;

	case NETDEV_CHANGEMTU:
		if (dev->mtu >= IPV6_MIN_MTU) {
			struct inet6_dev *idev;

			if ((idev = ipv6_get_idev(dev)) == NULL)
				break;
			idev->cnf.mtu6 = dev->mtu;
			rt6_mtu_change(dev, dev->mtu);
			break;
		}

		/* MTU falled under IPV6_MIN_MTU. Stop IPv6 on this interface. */

	case NETDEV_DOWN:
	case NETDEV_UNREGISTER:
		/*
		 *	Remove all addresses from this interface.
		 */
		if (addrconf_ifdown(dev, event != NETDEV_DOWN) == 0) {
#ifdef CONFIG_IPV6_NETLINK
			rt6_sndmsg(RTMSG_DELDEVICE, NULL, NULL, NULL, dev, 0, 0, 0, 0);
#endif
		}

		break;
	case NETDEV_CHANGE:
		break;
	};

	return NOTIFY_OK;
}

static int addrconf_ifdown(struct device *dev, int how)
{
	struct inet6_dev *idev, **bidev;
	struct inet6_ifaddr *ifa, **bifa;
	int i, hash;

	rt6_ifdown(dev);
	neigh_ifdown(&nd_tbl, dev);

	idev = ipv6_get_idev(dev);
	if (idev == NULL)
		return -ENODEV;

	start_bh_atomic();

	/* Discard address list */

	idev->addr_list = NULL;

	/*
	 * Clean addresses hash table
	 */

	for (i=0; i<16; i++) {
		bifa = &inet6_addr_lst[i];

		while ((ifa = *bifa) != NULL) {
			if (ifa->idev == idev) {
				*bifa = ifa->lst_next;
				del_timer(&ifa->timer);
				ipv6_ifa_notify(RTM_DELADDR, ifa);
				kfree(ifa);
				continue;
			}
			bifa = &ifa->lst_next;
		}
	}

	/* Discard multicast list */

	if (how == 1)
		ipv6_mc_destroy_dev(idev);
	else
		ipv6_mc_down(idev);

	/* Delete device from device hash table (if unregistered) */

	if (how == 1) {
		hash = ipv6_devindex_hash(dev->ifindex);

		for (bidev = &inet6_dev_lst[hash]; (idev=*bidev) != NULL; bidev = &idev->next) {
			if (idev->dev == dev) {
				*bidev = idev->next;
				neigh_parms_release(&nd_tbl, idev->nd_parms);
#ifdef CONFIG_SYSCTL
				addrconf_sysctl_unregister(&idev->cnf);
#endif
				kfree(idev);
				break;
			}
		}
	}
	end_bh_atomic();
	return 0;
}


static void addrconf_rs_timer(unsigned long data)
{
	struct inet6_ifaddr *ifp;

	ifp = (struct inet6_ifaddr *) data;

	if (ifp->idev->cnf.forwarding)
		return;

	if (ifp->idev->if_flags & IF_RA_RCVD) {
		/*
		 *	Announcement received after solicitation
		 *	was sent
		 */
		return;
	}

	if (ifp->probes++ <= ifp->idev->cnf.rtr_solicits) {
		struct in6_addr all_routers;

		ipv6_addr_all_routers(&all_routers);

		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &all_routers);
		
		ifp->timer.function = addrconf_rs_timer;
		ifp->timer.expires = (jiffies + 
				      ifp->idev->cnf.rtr_solicit_interval);
		add_timer(&ifp->timer);
	} else {
		struct in6_rtmsg rtmsg;

		printk(KERN_DEBUG "%s: no IPv6 routers present\n",
		       ifp->idev->dev->name);

		memset(&rtmsg, 0, sizeof(struct in6_rtmsg));
		rtmsg.rtmsg_type = RTMSG_NEWROUTE;
		rtmsg.rtmsg_metric = IP6_RT_PRIO_ADDRCONF;
		rtmsg.rtmsg_flags = (RTF_ALLONLINK | RTF_ADDRCONF | 
				     RTF_DEFAULT | RTF_UP);