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Commit 4bed72e4 authored by YOSHIFUJI Hideaki's avatar YOSHIFUJI Hideaki
Browse files

[IPV6] ADDRCONF: Allow longer lifetime on 64bit archs. 



- Allow longer lifetimes (>= 0x7fffffff/HZ) on 64bit archs
  by using unsigned long.
- Shadow this arithmetic overflow workaround by introducing
  helper functions: addrconf_timeout_fixup() and
  addrconf_finite_timeout().

Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
parent baa2bfb8

include/net/addrconf.h

+22 −0
Original line number Diff line number Diff line
@@ -94,6 +94,28 @@ extern void addrconf_join_solict(struct net_device *dev, 
extern void			addrconf_leave_solict(struct inet6_dev *idev,

					struct in6_addr *addr);



static inline unsigned long addrconf_timeout_fixup(u32 timeout,

						    unsigned unit)

{

	if (timeout == 0xffffffff)

		return ~0UL;



	/*

	 * Avoid arithmetic overflow.

	 * Assuming unit is constant and non-zero, this "if" statement

	 * will go away on 64bit archs.

	 */

	if (0xfffffffe > LONG_MAX / unit && timeout > LONG_MAX / unit)

		return LONG_MAX / unit;



	return timeout;

}



static inline int addrconf_finite_timeout(unsigned long timeout)

{

	return ~timeout;

}



/*

 *	IPv6 Address Label subsystem (addrlabel.c)

 */

net/ipv6/addrconf.c

+50 −47
Original line number Diff line number Diff line
@@ -731,8 +731,13 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) 
						onlink = -1;



					spin_lock(&ifa->lock);

					lifetime = min_t(unsigned long,

							 ifa->valid_lft, 0x7fffffffUL/HZ);



					lifetime = addrconf_timeout_fixup(ifa->valid_lft, HZ);

					/*

					 * Note: Because this address is

					 * not permanent, lifetime <

					 * LONG_MAX / HZ here.

					 */

					if (time_before(expires,

							ifa->tstamp + lifetime * HZ))

						expires = ifa->tstamp + lifetime * HZ;
@@ -1722,7 +1727,6 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len) 
	__u32 valid_lft;

	__u32 prefered_lft;

	int addr_type;

	unsigned long rt_expires;

	struct inet6_dev *in6_dev;



	pinfo = (struct prefix_info *) opt;
@@ -1764,28 +1768,23 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len) 
	 *	2) Configure prefixes with the auto flag set

	 */



	if (valid_lft == INFINITY_LIFE_TIME)

		rt_expires = ~0UL;

	else if (valid_lft >= 0x7FFFFFFF/HZ) {

	if (pinfo->onlink) {

		struct rt6_info *rt;

		unsigned long rt_expires;



		/* 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.

		 */

		rt_expires = 0x7FFFFFFF - (0x7FFFFFFF % HZ);

	} else

		rt_expires = valid_lft * HZ;

		if (HZ > USER_HZ)

			rt_expires = addrconf_timeout_fixup(valid_lft, HZ);

		else

			rt_expires = addrconf_timeout_fixup(valid_lft, USER_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 && rt_expires > 0x7FFFFFFF / USER_HZ)

		rt_expires = 0x7FFFFFFF / USER_HZ;

		if (addrconf_finite_timeout(rt_expires))

			rt_expires *= HZ;



	if (pinfo->onlink) {

		struct rt6_info *rt;

		rt = rt6_lookup(dev_net(dev), &pinfo->prefix, NULL,

				dev->ifindex, 1);
@@ -1794,7 +1793,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len) 
			if (valid_lft == 0) {

				ip6_del_rt(rt);

				rt = NULL;

			} else if (~rt_expires) {

			} else if (addrconf_finite_timeout(rt_expires)) {

				/* not infinity */

				rt->rt6i_expires = jiffies + rt_expires;

				rt->rt6i_flags |= RTF_EXPIRES;
@@ -1803,9 +1802,9 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len) 
				rt->rt6i_expires = 0;

			}

		} else if (valid_lft) {

			int flags = RTF_ADDRCONF | RTF_PREFIX_RT;

			clock_t expires = 0;

			if (~rt_expires) {

			int flags = RTF_ADDRCONF | RTF_PREFIX_RT;

			if (addrconf_finite_timeout(rt_expires)) {

				/* not infinity */

				flags |= RTF_EXPIRES;

				expires = jiffies_to_clock_t(rt_expires);
@@ -2036,6 +2035,7 @@ static int inet6_addr_add(struct net *net, int ifindex, struct in6_addr *pfx, 
	int scope;

	u32 flags;

	clock_t expires;

	unsigned long timeout;



	ASSERT_RTNL();
@@ -2055,22 +2055,23 @@ static int inet6_addr_add(struct net *net, int ifindex, struct in6_addr *pfx, 


	scope = ipv6_addr_scope(pfx);



	if (valid_lft == INFINITY_LIFE_TIME) {

		ifa_flags |= IFA_F_PERMANENT;

		flags = 0;

		expires = 0;

	} else {

		if (valid_lft >= 0x7FFFFFFF/HZ)

			valid_lft = 0x7FFFFFFF/HZ;

	timeout = addrconf_timeout_fixup(valid_lft, HZ);

	if (addrconf_finite_timeout(timeout)) {

		expires = jiffies_to_clock_t(timeout * HZ);

		valid_lft = timeout;

		flags = RTF_EXPIRES;

		expires = jiffies_to_clock_t(valid_lft * HZ);

	} else {

		expires = 0;

		flags = 0;

		ifa_flags |= IFA_F_PERMANENT;

	}



	if (prefered_lft == 0)

	timeout = addrconf_timeout_fixup(prefered_lft, HZ);

	if (addrconf_finite_timeout(timeout)) {

		if (timeout == 0)

			ifa_flags |= IFA_F_DEPRECATED;

	else if ((prefered_lft >= 0x7FFFFFFF/HZ) &&

		 (prefered_lft != INFINITY_LIFE_TIME))

		prefered_lft = 0x7FFFFFFF/HZ;

		prefered_lft = timeout;

	}



	ifp = ipv6_add_addr(idev, pfx, plen, scope, ifa_flags);
@@ -3175,26 +3176,28 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags, 
{

	u32 flags;

	clock_t expires;

	unsigned long timeout;



	if (!valid_lft || (prefered_lft > valid_lft))

		return -EINVAL;



	if (valid_lft == INFINITY_LIFE_TIME) {

		ifa_flags |= IFA_F_PERMANENT;

		flags = 0;

		expires = 0;

	} else {

		if (valid_lft >= 0x7FFFFFFF/HZ)

			valid_lft = 0x7FFFFFFF/HZ;

	timeout = addrconf_timeout_fixup(valid_lft, HZ);

	if (addrconf_finite_timeout(timeout)) {

		expires = jiffies_to_clock_t(timeout * HZ);

		valid_lft = timeout;

		flags = RTF_EXPIRES;

		expires = jiffies_to_clock_t(valid_lft * HZ);

	} else {

		expires = 0;

		flags = 0;

		ifa_flags |= IFA_F_PERMANENT;

	}



	if (prefered_lft == 0)

	timeout = addrconf_timeout_fixup(prefered_lft, HZ);

	if (addrconf_finite_timeout(timeout)) {

		if (timeout == 0)

			ifa_flags |= IFA_F_DEPRECATED;

	else if ((prefered_lft >= 0x7FFFFFFF/HZ) &&

		 (prefered_lft != INFINITY_LIFE_TIME))

		prefered_lft = 0x7FFFFFFF/HZ;

		prefered_lft = timeout;

	}



	spin_lock_bh(&ifp->lock);

	ifp->flags = (ifp->flags & ~(IFA_F_DEPRECATED | IFA_F_PERMANENT | IFA_F_NODAD | IFA_F_HOMEADDRESS)) | ifa_flags;

net/ipv6/route.c

+3 −9
Original line number Diff line number Diff line
@@ -446,7 +446,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 
	struct route_info *rinfo = (struct route_info *) opt;

	struct in6_addr prefix_buf, *prefix;

	unsigned int pref;

	u32 lifetime;

	unsigned long lifetime;

	struct rt6_info *rt;



	if (len < sizeof(struct route_info)) {
@@ -472,13 +472,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 
	if (pref == ICMPV6_ROUTER_PREF_INVALID)

		pref = ICMPV6_ROUTER_PREF_MEDIUM;



	lifetime = ntohl(rinfo->lifetime);

	if (lifetime == 0xffffffff) {

		/* infinity */

	} else if (lifetime > 0x7fffffff/HZ - 1) {

		/* Avoid arithmetic overflow */

		lifetime = 0x7fffffff/HZ - 1;

	}

	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);



	if (rinfo->length == 3)

		prefix = (struct in6_addr *)rinfo->prefix;
@@ -506,7 +500,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 
				 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);



	if (rt) {

		if (lifetime == 0xffffffff) {

		if (!addrconf_finite_timeout(lifetime)) {

			rt->rt6i_flags &= ~RTF_EXPIRES;

		} else {

			rt->rt6i_expires = jiffies + HZ * lifetime;