addrconf.c

Linux Kernel 2.6.9 for OMAP1710

/*
 *	IPv6 Address [auto]configuration
 *	Linux INET6 implementation
 *
 *	Authors:
 *	Pedro Roque		<[e-mail]>	
 *	Alexey Kuznetsov	<[e-mail]>
 *
 *	$Id: addrconf.c,v 1.69 2001/10/31 21:55:54 davem Exp $
 *
 *	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:
 *
 *	Janos Farkas			:	delete timer on ifdown
 *	<[e-mail]>
 *	Andi Kleen			:	kill double kfree on module
 *						unload.
 *	Maciej W. Rozycki		:	FDDI support
 *	sekiya@USAGI			:	Don't send too many RS
 *						packets.
 *	yoshfuji@USAGI			:       Fixed interval between DAD
 *						packets.
 *	YOSHIFUJI Hideaki @USAGI	:	improved accuracy of
 *						address validation timer.
 *	YOSHIFUJI Hideaki @USAGI	:	Privacy Extensions (RFC3041)
 *						support.
 *	Yuji SEKIYA @USAGI		:	Don't assign a same IPv6
 *						address on a same interface.
 *	YOSHIFUJI Hideaki @USAGI	:	ARCnet support
 *	YOSHIFUJI Hideaki @USAGI	:	convert /proc/net/if_inet6 to
 *						seq_file.
 */

#include <linux/config.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/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_arcnet.h>
#include <linux/route.h>
#include <linux/inetdevice.h>
#include <linux/init.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
#include <linux/delay.h>
#include <linux/notifier.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/tcp.h>
#include <net/ip.h>
#include <linux/if_tunnel.h>
#include <linux/rtnetlink.h>

#ifdef CONFIG_IPV6_PRIVACY
#include <linux/random.h>
#include <linux/crypto.h>
#include <asm/scatterlist.h>
#endif

#include <asm/uaccess.h>

#include <linux/proc_fs.h>
#include <linux/seq_file.h>

/* Set to 3 to get tracing... */
#define ACONF_DEBUG 2

#if ACONF_DEBUG >= 3
#define ADBG(x) printk x
#else
#define ADBG(x)
#endif

#define	INFINITY_LIFE_TIME	0xFFFFFFFF
#define TIME_DELTA(a,b) ((unsigned long)((long)(a) - (long)(b)))

#ifdef CONFIG_SYSCTL
static void addrconf_sysctl_register(struct inet6_dev *idev, struct ipv6_devconf *p);
static void addrconf_sysctl_unregister(struct ipv6_devconf *p);
#endif

int inet6_dev_count;
int inet6_ifa_count;

#ifdef CONFIG_IPV6_PRIVACY
static int __ipv6_regen_rndid(struct inet6_dev *idev);
static int __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr); 
static void ipv6_regen_rndid(unsigned long data);

static int desync_factor = MAX_DESYNC_FACTOR * HZ;
static struct crypto_tfm *md5_tfm;
static spinlock_t md5_tfm_lock = SPIN_LOCK_UNLOCKED;
#endif

static int ipv6_count_addresses(struct inet6_dev *idev);

/*
 *	Configured unicast address hash table
 */
static struct inet6_ifaddr		*inet6_addr_lst[IN6_ADDR_HSIZE];
static rwlock_t	addrconf_hash_lock = RW_LOCK_UNLOCKED;

/* Protects inet6 devices */
rwlock_t addrconf_lock = RW_LOCK_UNLOCKED;

static void addrconf_verify(unsigned long);

static struct timer_list addr_chk_timer =
			TIMER_INITIALIZER(addrconf_verify, 0, 0);
static spinlock_t addrconf_verify_lock = SPIN_LOCK_UNLOCKED;

static void addrconf_join_anycast(struct inet6_ifaddr *ifp);
static void addrconf_leave_anycast(struct inet6_ifaddr *ifp);

static int addrconf_ifdown(struct net_device *dev, int how);

static void addrconf_dad_start(struct inet6_ifaddr *ifp, int flags);
static void addrconf_dad_timer(unsigned long data);
static void addrconf_dad_completed(struct inet6_ifaddr *ifp);
static void addrconf_rs_timer(unsigned long data);
static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifa);

static void inet6_prefix_notify(int event, struct inet6_dev *idev, 
				struct prefix_info *pinfo);
static int ipv6_chk_same_addr(const struct in6_addr *addr, struct net_device *dev);

static struct notifier_block *inet6addr_chain;

struct ipv6_devconf ipv6_devconf = {
	.forwarding		= 0,
	.hop_limit		= IPV6_DEFAULT_HOPLIMIT,
	.mtu6			= IPV6_MIN_MTU,
	.accept_ra		= 1,
	.accept_redirects	= 1,
	.autoconf		= 1,
	.force_mld_version	= 0,
	.dad_transmits		= 1,
	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
#ifdef CONFIG_IPV6_PRIVACY
	.use_tempaddr 		= 0,
	.temp_valid_lft		= TEMP_VALID_LIFETIME,
	.temp_prefered_lft	= TEMP_PREFERRED_LIFETIME,
	.regen_max_retry	= REGEN_MAX_RETRY,
	.max_desync_factor	= MAX_DESYNC_FACTOR,
#endif
	.max_addresses		= IPV6_MAX_ADDRESSES,
};

static struct ipv6_devconf ipv6_devconf_dflt = {
	.forwarding		= 0,
	.hop_limit		= IPV6_DEFAULT_HOPLIMIT,
	.mtu6			= IPV6_MIN_MTU,
	.accept_ra		= 1,
	.accept_redirects	= 1,
	.autoconf		= 1,
	.dad_transmits		= 1,
	.rtr_solicits		= MAX_RTR_SOLICITATIONS,
	.rtr_solicit_interval	= RTR_SOLICITATION_INTERVAL,
	.rtr_solicit_delay	= MAX_RTR_SOLICITATION_DELAY,
#ifdef CONFIG_IPV6_PRIVACY
	.use_tempaddr		= 0,
	.temp_valid_lft		= TEMP_VALID_LIFETIME,
	.temp_prefered_lft	= TEMP_PREFERRED_LIFETIME,
	.regen_max_retry	= REGEN_MAX_RETRY,
	.max_desync_factor	= MAX_DESYNC_FACTOR,
#endif
	.max_addresses		= IPV6_MAX_ADDRESSES,
};

/* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;

int ipv6_addr_type(const struct in6_addr *addr)
{
	int type;
	u32 st;

	st = addr->s6_addr32[0];

	if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
		type = IPV6_ADDR_MULTICAST;

		switch((st & htonl(0x00FF0000))) {
			case __constant_htonl(0x00010000):
				type |= IPV6_ADDR_LOOPBACK;
				break;

			case __constant_htonl(0x00020000):
				type |= IPV6_ADDR_LINKLOCAL;
				break;

			case __constant_htonl(0x00050000):
				type |= IPV6_ADDR_SITELOCAL;
				break;
		};
		return type;
	}

	type = IPV6_ADDR_UNICAST;

	/* Consider all addresses with the first three bits different of
	   000 and 111 as finished.
	 */
	if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
	    (st & htonl(0xE0000000)) != htonl(0xE0000000))
		return type;
	
	if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
		return (IPV6_ADDR_LINKLOCAL | type);

	if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
		return (IPV6_ADDR_SITELOCAL | type);

	if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
		if (addr->s6_addr32[2] == 0) {
			if (addr->s6_addr32[3] == 0)
				return IPV6_ADDR_ANY;

			if (addr->s6_addr32[3] == htonl(0x00000001))
				return (IPV6_ADDR_LOOPBACK | type);

			return (IPV6_ADDR_COMPATv4 | type);
		}

		if (addr->s6_addr32[2] == htonl(0x0000ffff))
			return IPV6_ADDR_MAPPED;
	}

	st &= htonl(0xFF000000);
	if (st == 0)
		return IPV6_ADDR_RESERVED;
	st &= htonl(0xFE000000);
	if (st == htonl(0x02000000))
		return IPV6_ADDR_RESERVED;	/* for NSAP */
	if (st == htonl(0x04000000))
		return IPV6_ADDR_RESERVED;	/* for IPX */
	return type;
}

static void addrconf_del_timer(struct inet6_ifaddr *ifp)
{
	if (del_timer(&ifp->timer))
		__in6_ifa_put(ifp);
}

enum addrconf_timer_t
{
	AC_NONE,
	AC_DAD,
	AC_RS,
};

static void addrconf_mod_timer(struct inet6_ifaddr *ifp,
			       enum addrconf_timer_t what,
			       unsigned long when)
{
	if (!del_timer(&ifp->timer))
		in6_ifa_hold(ifp);

	switch (what) {
	case AC_DAD:
		ifp->timer.function = addrconf_dad_timer;
		break;
	case AC_RS:
		ifp->timer.function = addrconf_rs_timer;
		break;
	default:;
	}
	ifp->timer.expires = jiffies + when;
	add_timer(&ifp->timer);
}

/* Nobody refers to this device, we may destroy it. */

void in6_dev_finish_destroy(struct inet6_dev *idev)
{
	struct net_device *dev = idev->dev;
	BUG_TRAP(idev->addr_list==NULL);
	BUG_TRAP(idev->mc_list==NULL);
#ifdef NET_REFCNT_DEBUG
	printk(KERN_DEBUG "in6_dev_finish_destroy: %s\n", dev ? dev->name : "NIL");
#endif
	dev_put(dev);
	if (!idev->dead) {
		printk("Freeing alive inet6 device %p\n", idev);
		return;
	}
	snmp6_unregister_dev(idev);
	inet6_dev_count--;
	kfree(idev);
}

static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
{
	struct inet6_dev *ndev;

	ASSERT_RTNL();

	if (dev->mtu < IPV6_MIN_MTU)
		return NULL;

	ndev = kmalloc(sizeof(struct inet6_dev), GFP_KERNEL);

	if (ndev) {
		memset(ndev, 0, sizeof(struct inet6_dev));

		ndev->lock = RW_LOCK_UNLOCKED;
		ndev->dev = dev;
		memcpy(&ndev->cnf, &ipv6_devconf_dflt, sizeof(ndev->cnf));
		ndev->cnf.mtu6 = dev->mtu;
		ndev->cnf.sysctl = NULL;
		ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl);
		if (ndev->nd_parms == NULL) {
			kfree(ndev);
			return NULL;
		}
		inet6_dev_count++;
		/* We refer to the device */
		dev_hold(dev);

		if (snmp6_register_dev(ndev) < 0) {
			ADBG((KERN_WARNING
				"%s(): cannot create /proc/net/dev_snmp6/%s\n",
				__FUNCTION__, dev->name));
			neigh_parms_release(&nd_tbl, ndev->nd_parms);
			ndev->dead = 1;
			in6_dev_finish_destroy(ndev);
			return NULL;
		}

		/* One reference from device.  We must do this before
		 * we invoke __ipv6_regen_rndid().
		 */
		in6_dev_hold(ndev);

#ifdef CONFIG_IPV6_PRIVACY
		get_random_bytes(ndev->rndid, sizeof(ndev->rndid));
		get_random_bytes(ndev->entropy, sizeof(ndev->entropy));
		init_timer(&ndev->regen_timer);
		ndev->regen_timer.function = ipv6_regen_rndid;
		ndev->regen_timer.data = (unsigned long) ndev;
		if ((dev->flags&IFF_LOOPBACK) ||
		    dev->type == ARPHRD_TUNNEL ||
		    dev->type == ARPHRD_SIT) {
			printk(KERN_INFO
				"Disabled Privacy Extensions on device %p(%s)\n",
				dev, dev->name);
			ndev->cnf.use_tempaddr = -1;
		} else {
			in6_dev_hold(ndev);
			ipv6_regen_rndid((unsigned long) ndev);
		}
#endif

		write_lock_bh(&addrconf_lock);
		dev->ip6_ptr = ndev;
		write_unlock_bh(&addrconf_lock);

		ipv6_mc_init_dev(ndev);
		ndev->tstamp = jiffies;
#ifdef CONFIG_SYSCTL
		neigh_sysctl_register(dev, ndev->nd_parms, NET_IPV6, 
			NET_IPV6_NEIGH, "ipv6", &ndisc_ifinfo_sysctl_change);
		addrconf_sysctl_register(ndev, &ndev->cnf);
#endif
	}
	return ndev;
}

static struct inet6_dev * ipv6_find_idev(struct net_device *dev)
{
	struct inet6_dev *idev;

	ASSERT_RTNL();

	if ((idev = __in6_dev_get(dev)) == NULL) {
		if ((idev = ipv6_add_dev(dev)) == NULL)
			return NULL;
	}
	if (dev->flags&IFF_UP)
		ipv6_mc_up(idev);
	return idev;
}

static void dev_forward_change(struct inet6_dev *idev)
{
	struct net_device *dev;
	struct inet6_ifaddr *ifa;
	struct in6_addr addr;

	if (!idev)
		return;
	dev = idev->dev;
	if (dev && (dev->flags & IFF_MULTICAST)) {
		ipv6_addr_all_routers(&addr);
	
		if (idev->cnf.forwarding)
			ipv6_dev_mc_inc(dev, &addr);
		else
			ipv6_dev_mc_dec(dev, &addr);
	}
	for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
		if (idev->cnf.forwarding)
			addrconf_join_anycast(ifa);
		else
			addrconf_leave_anycast(ifa);
	}
}


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

	read_lock(&dev_base_lock);
	for (dev=dev_base; dev; dev=dev->next) {
		read_lock(&addrconf_lock);
		idev = __in6_dev_get(dev);
		if (idev) {
			int changed = (!idev->cnf.forwarding) ^ (!ipv6_devconf.forwarding);
			idev->cnf.forwarding = ipv6_devconf.forwarding;
			if (changed)
				dev_forward_change(idev);
		}
		read_unlock(&addrconf_lock);
	}
	read_unlock(&dev_base_lock);
}


/* Nobody refers to this ifaddr, destroy it */

void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp)
{
	BUG_TRAP(ifp->if_next==NULL);
	BUG_TRAP(ifp->lst_next==NULL);
#ifdef NET_REFCNT_DEBUG
	printk(KERN_DEBUG "inet6_ifa_finish_destroy\n");
#endif

	in6_dev_put(ifp->idev);

	if (del_timer(&ifp->timer))
		printk("Timer is still running, when freeing ifa=%p\n", ifp);

	if (!ifp->dead) {
		printk("Freeing alive inet6 address %p\n", ifp);
		return;
	}
	dst_release(&ifp->rt->u.dst);

	inet6_ifa_count--;
	kfree(ifp);
}

/* On success it returns ifp with increased reference count */

static struct inet6_ifaddr *
ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
	      int scope, unsigned flags)
{
	struct inet6_ifaddr *ifa = NULL;
	struct rt6_info *rt;
	int hash;
	static spinlock_t lock = SPIN_LOCK_UNLOCKED;
	int err = 0;

	spin_lock_bh(&lock);

	/* Ignore adding duplicate addresses on an interface */
	if (ipv6_chk_same_addr(addr, idev->dev)) {
		ADBG(("ipv6_add_addr: already assigned\n"));
		err = -EEXIST;
		goto out;
	}

	ifa = kmalloc(sizeof(struct inet6_ifaddr), GFP_ATOMIC);

	if (ifa == NULL) {
		ADBG(("ipv6_add_addr: malloc failed\n"));
		err = -ENOBUFS;
		goto out;
	}

	rt = addrconf_dst_alloc(idev, addr, 0);
	if (IS_ERR(rt)) {
		err = PTR_ERR(rt);
		goto out;
	}

	memset(ifa, 0, sizeof(struct inet6_ifaddr));
	ipv6_addr_copy(&ifa->addr, addr);

	spin_lock_init(&ifa->lock);
	init_timer(&ifa->timer);
	ifa->timer.data = (unsigned long) ifa;
	ifa->scope = scope;
	ifa->prefix_len = pfxlen;
	ifa->flags = flags | IFA_F_TENTATIVE;
	ifa->cstamp = ifa->tstamp = jiffies;

	read_lock(&addrconf_lock);
	if (idev->dead) {
		read_unlock(&addrconf_lock);
		err = -ENODEV;	/*XXX*/
		goto out;
	}

	inet6_ifa_count++;
	ifa->idev = idev;
	in6_dev_hold(idev);
	/* For caller */
	in6_ifa_hold(ifa);

	/* Add to big hash table */
	hash = ipv6_addr_hash(addr);

	write_lock_bh(&addrconf_hash_lock);
	ifa->lst_next = inet6_addr_lst[hash];
	inet6_addr_lst[hash] = ifa;
	in6_ifa_hold(ifa);