addrconf.c

嵌入式系统设计与实验教材二源码linux内核移植与编译

			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 *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 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] = __constant_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 (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 (dev = dev_base; dev != NULL; dev = dev->next) {
		struct in_device * in_dev = __in_dev_get(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 = 10;
				else
					plen = 96;

				ifp = ipv6_add_addr(idev, &addr, plen, flag,
						    IFA_F_PERMANENT);
				if (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 init_loopback(struct net_device *dev)
{
	struct in6_addr addr;
	struct inet6_dev  *idev;
	struct inet6_ifaddr * ifp;

	/* ::1 */

	ASSERT_RTNL();

	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;
	}

	ifp = ipv6_add_addr(idev, &addr, 128, IFA_HOST, IFA_F_PERMANENT);
	if (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;

	ifp = ipv6_add_addr(idev, addr, 10, IFA_LINK, IFA_F_PERMANENT);
	if (ifp) {
		addrconf_dad_start(ifp);
		in6_ifa_put(ifp);
	}
}

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

	ASSERT_RTNL();

	if ((dev->type != ARPHRD_ETHER) && 
	    (dev->type != ARPHRD_FDDI) &&
	    (dev->type != ARPHRD_IEEE802_TR)) {
		/* Alas, we support only Ethernet autoconfiguration. */
		return;
	}

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

	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);
}

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

	ASSERT_RTNL();

	/* 
	 * 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 net_device *dev;

	dev = (struct net_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;
		};
		break;

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

			if ((idev = __in6_dev_get(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.
		 */
		addrconf_ifdown(dev, event != NETDEV_DOWN);
		break;
	case NETDEV_CHANGE:
		break;
	};

	return NOTIFY_OK;
}

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

	ASSERT_RTNL();

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

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

	/* Step 1: remove reference to ipv6 device from parent device.
	           Do not dev_put!
	 */
	if (how == 1) {
		write_lock_bh(&addrconf_lock);
		dev->ip6_ptr = NULL;
		idev->dead = 1;
		write_unlock_bh(&addrconf_lock);
	}

	/* Step 2: clear hash table */
	for (i=0; i<IN6_ADDR_HSIZE; i++) {
		bifa = &inet6_addr_lst[i];

		write_lock_bh(&addrconf_hash_lock);
		while ((ifa = *bifa) != NULL) {
			if (ifa->idev == idev) {
				*bifa = ifa->lst_next;
				ifa->lst_next = NULL;
				addrconf_del_timer(ifa);
				in6_ifa_put(ifa);
				continue;
			}
			bifa = &ifa->lst_next;
		}
		write_unlock_bh(&addrconf_hash_lock);
	}

	/* Step 3: clear address list */

	write_lock_bh(&idev->lock);
	while ((ifa = idev->addr_list) != NULL) {
		idev->addr_list = ifa->if_next;
		ifa->if_next = NULL;
		ifa->dead = 1;
		addrconf_del_timer(ifa);
		write_unlock_bh(&idev->lock);

		ipv6_ifa_notify(RTM_DELADDR, ifa);
		in6_ifa_put(ifa);

		write_lock_bh(&idev->lock);
	}
	write_unlock_bh(&idev->lock);

	/* Step 4: Discard multicast list */

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

	/* Shot the device (if unregistered) */

	if (how == 1) {
		neigh_parms_release(&nd_tbl, idev->nd_parms);
#ifdef CONFIG_SYSCTL
		addrconf_sysctl_unregister(&idev->cnf);
#endif
		in6_dev_put(idev);
	}
	return 0;
}

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

	if (ifp->idev->cnf.forwarding)
		goto out;

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

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

		/* The wait after the last probe can be shorter */
		addrconf_mod_timer(ifp, AC_RS,
				   (ifp->probes == ifp->idev->cnf.rtr_solicits) ?
				   ifp->idev->cnf.rtr_solicit_delay :
				   ifp->idev->cnf.rtr_solicit_interval);
		spin_unlock(&ifp->lock);

		ipv6_addr_all_routers(&all_routers);

		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &all_routers);
	} else {
		struct in6_rtmsg rtmsg;

		spin_unlock(&ifp->lock);

		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);

		rtmsg.rtmsg_ifindex = ifp->idev->dev->ifindex;

		ip6_route_add(&rtmsg);
	}

out:
	in6_ifa_put(ifp);
}

/*
 *	Duplicate Address Detection
 */
static void addrconf_dad_start(struct inet6_ifaddr *ifp)
{
	struct net_device *dev;
	unsigned long rand_num;

	dev = ifp->idev->dev;

	addrconf_join_solict(dev, &ifp->addr);

	if (ifp->prefix_len != 128 && (ifp->flags&IFA_F_PERMANENT))
		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev, 0, RTF_ADDRCONF);

	net_srandom(ifp->addr.s6_addr32[3]);
	rand_num = net_random() % (ifp->idev->cnf.rtr_solicit_delay ? : 1);

	spin_lock_bh(&ifp->lock);

	if (dev->flags&(IFF_NOARP|IFF_LOOPBACK) ||
	    !(ifp->flags&IFA_F_TENTATIVE)) {
		ifp->flags &= ~IFA_F_TENTATIVE;
		spin_unlock_bh(&ifp->lock);

		addrconf_dad_completed(ifp);
		return;
	}

	ifp->probes = ifp->idev->cnf.dad_transmits;
	addrconf_mod_timer(ifp, AC_DAD, rand_num);

	spin_unlock_bh(&ifp->lock);
}

static void addrconf_dad_timer(unsigned long data)
{
	struct inet6_ifaddr *ifp = (struct inet6_ifaddr *) data;
	struct in6_addr unspec;
	struct in6_addr mcaddr;

	spin_lock_bh(&ifp->lock);
	if (ifp->probes == 0) {
		/*
		 * DAD was successful
		 */

		ifp->flags &= ~IFA_F_TENTATIVE;
		spin_unlock_bh(&ifp->lock);

		addrconf_dad_completed(ifp);

		in6_ifa_put(ifp);
		return;
	}

	ifp->probes--;
	addrconf_mod_timer(ifp, AC_DAD, ifp->idev->nd_parms->retrans_time);
	spin_unlock_bh(&ifp->lock);

	/* send a neighbour solicitation for our addr */
	memset(&unspec, 0, sizeof(unspec));
	addrconf_addr_solict_mult(&ifp->addr, &mcaddr);
	ndisc_send_ns(ifp->idev->dev, NULL, &ifp->addr, &mcaddr, &unspec);

	in6_ifa_put(ifp);
}

static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
{
	struct net_device *	dev = ifp->idev->dev;

	/*
	 *	Configure the address for reception. Now it is valid.
	 */

	ipv6_ifa_notify(RTM_NEWADDR, ifp);

	/* If added prefix is link local and forwarding is off,
	   start sending router solicitations.
	 */

	if (ifp->idev->cnf.forwarding == 0 &&
	    (dev->flags&IFF_LOOPBACK) == 0 &&
	    (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)) {
		struct in6_addr all_routers;

		ipv6_addr_all_routers(&all_routers);

		/*
		 *	If a host as already performed a random delay
		 *	[...] as part of DAD [...] there is no need
		 *	to delay again before sending the first RS
		 */
		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &all_routers);

		spin_lock_bh(&ifp->lock);
		ifp->probes = 1;
		ifp->idev->if_flags |= IF_RS_SENT;
		addrconf_mod_timer(ifp, AC_RS, ifp->idev->cnf.rtr_solicit_interval);
		spin_unlock_bh(&ifp->lock);
	}
}

#ifdef CONFIG_PROC_FS
static int iface_proc_info(char *buffer, char **start, off_t offset,
			   int length)
{
	struct inet6_ifaddr *ifp;
	int i;
	int len = 0;
	off_t pos=0;
	off_t begin=0;

	for (i=0; i < IN6_ADDR_HSIZE; i++) {
		read_lock_bh(&addrconf_hash_lock);
		for (ifp=inet6_addr_lst[i]; ifp; ifp=ifp->lst_next) {
			int j;

			for (j=0; j<16; j++) {
				sprintf(buffer + len, "%02x",
					ifp->addr.s6_addr[j]);
				len += 2;
			}

			len += sprintf(buffer + len,
				       " %02x %02x %02x %02x %8s\n",
				       ifp->idev->dev->ifindex,