[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: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
This commit is contained in:
YOSHIFUJI Hideaki
parent
baa2bfb8ae
commit
4bed72e4f5
3 changed files with 75 additions and 56 deletions
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@ -94,6 +94,28 @@ extern void addrconf_join_solict(struct net_device *dev,
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extern void addrconf_leave_solict(struct inet6_dev *idev,
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struct in6_addr *addr);
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static inline unsigned long addrconf_timeout_fixup(u32 timeout,
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unsigned unit)
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{
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if (timeout == 0xffffffff)
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return ~0UL;
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/*
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* Avoid arithmetic overflow.
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* Assuming unit is constant and non-zero, this "if" statement
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* will go away on 64bit archs.
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*/
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if (0xfffffffe > LONG_MAX / unit && timeout > LONG_MAX / unit)
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return LONG_MAX / unit;
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return timeout;
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}
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static inline int addrconf_finite_timeout(unsigned long timeout)
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{
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return ~timeout;
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}
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/*
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* IPv6 Address Label subsystem (addrlabel.c)
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*/
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@ -731,8 +731,13 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
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onlink = -1;
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spin_lock(&ifa->lock);
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lifetime = min_t(unsigned long,
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ifa->valid_lft, 0x7fffffffUL/HZ);
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lifetime = addrconf_timeout_fixup(ifa->valid_lft, HZ);
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/*
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* Note: Because this address is
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* not permanent, lifetime <
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* LONG_MAX / HZ here.
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*/
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if (time_before(expires,
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ifa->tstamp + lifetime * HZ))
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expires = ifa->tstamp + lifetime * HZ;
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@ -1722,7 +1727,6 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
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__u32 valid_lft;
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__u32 prefered_lft;
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int addr_type;
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unsigned long rt_expires;
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struct inet6_dev *in6_dev;
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pinfo = (struct prefix_info *) opt;
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@ -1764,28 +1768,23 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
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* 2) Configure prefixes with the auto flag set
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*/
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if (valid_lft == INFINITY_LIFE_TIME)
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rt_expires = ~0UL;
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else if (valid_lft >= 0x7FFFFFFF/HZ) {
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if (pinfo->onlink) {
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struct rt6_info *rt;
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unsigned long rt_expires;
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/* Avoid arithmetic overflow. Really, we could
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* save rt_expires in seconds, likely valid_lft,
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* but it would require division in fib gc, that it
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* not good.
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*/
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rt_expires = 0x7FFFFFFF - (0x7FFFFFFF % HZ);
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} else
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rt_expires = valid_lft * HZ;
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if (HZ > USER_HZ)
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rt_expires = addrconf_timeout_fixup(valid_lft, HZ);
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else
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rt_expires = addrconf_timeout_fixup(valid_lft, USER_HZ);
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/*
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* We convert this (in jiffies) to clock_t later.
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* Avoid arithmetic overflow there as well.
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* Overflow can happen only if HZ < USER_HZ.
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*/
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if (HZ < USER_HZ && ~rt_expires && rt_expires > 0x7FFFFFFF / USER_HZ)
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rt_expires = 0x7FFFFFFF / USER_HZ;
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if (addrconf_finite_timeout(rt_expires))
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rt_expires *= HZ;
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if (pinfo->onlink) {
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struct rt6_info *rt;
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rt = rt6_lookup(dev_net(dev), &pinfo->prefix, NULL,
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dev->ifindex, 1);
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@ -1794,7 +1793,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
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if (valid_lft == 0) {
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ip6_del_rt(rt);
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rt = NULL;
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} else if (~rt_expires) {
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} else if (addrconf_finite_timeout(rt_expires)) {
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/* not infinity */
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rt->rt6i_expires = jiffies + rt_expires;
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rt->rt6i_flags |= RTF_EXPIRES;
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@ -1803,9 +1802,9 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
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rt->rt6i_expires = 0;
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}
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} else if (valid_lft) {
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int flags = RTF_ADDRCONF | RTF_PREFIX_RT;
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clock_t expires = 0;
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if (~rt_expires) {
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int flags = RTF_ADDRCONF | RTF_PREFIX_RT;
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if (addrconf_finite_timeout(rt_expires)) {
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/* not infinity */
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flags |= RTF_EXPIRES;
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expires = jiffies_to_clock_t(rt_expires);
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@ -2036,6 +2035,7 @@ static int inet6_addr_add(struct net *net, int ifindex, struct in6_addr *pfx,
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int scope;
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u32 flags;
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clock_t expires;
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unsigned long timeout;
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ASSERT_RTNL();
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@ -2055,22 +2055,23 @@ static int inet6_addr_add(struct net *net, int ifindex, struct in6_addr *pfx,
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scope = ipv6_addr_scope(pfx);
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if (valid_lft == INFINITY_LIFE_TIME) {
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ifa_flags |= IFA_F_PERMANENT;
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flags = 0;
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expires = 0;
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} else {
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if (valid_lft >= 0x7FFFFFFF/HZ)
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valid_lft = 0x7FFFFFFF/HZ;
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timeout = addrconf_timeout_fixup(valid_lft, HZ);
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if (addrconf_finite_timeout(timeout)) {
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expires = jiffies_to_clock_t(timeout * HZ);
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valid_lft = timeout;
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flags = RTF_EXPIRES;
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expires = jiffies_to_clock_t(valid_lft * HZ);
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} else {
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expires = 0;
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flags = 0;
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ifa_flags |= IFA_F_PERMANENT;
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}
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if (prefered_lft == 0)
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ifa_flags |= IFA_F_DEPRECATED;
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else if ((prefered_lft >= 0x7FFFFFFF/HZ) &&
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(prefered_lft != INFINITY_LIFE_TIME))
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prefered_lft = 0x7FFFFFFF/HZ;
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timeout = addrconf_timeout_fixup(prefered_lft, HZ);
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if (addrconf_finite_timeout(timeout)) {
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if (timeout == 0)
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ifa_flags |= IFA_F_DEPRECATED;
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prefered_lft = timeout;
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}
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ifp = ipv6_add_addr(idev, pfx, plen, scope, ifa_flags);
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@ -3175,26 +3176,28 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
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{
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u32 flags;
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clock_t expires;
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unsigned long timeout;
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if (!valid_lft || (prefered_lft > valid_lft))
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return -EINVAL;
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if (valid_lft == INFINITY_LIFE_TIME) {
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ifa_flags |= IFA_F_PERMANENT;
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flags = 0;
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expires = 0;
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} else {
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if (valid_lft >= 0x7FFFFFFF/HZ)
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valid_lft = 0x7FFFFFFF/HZ;
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timeout = addrconf_timeout_fixup(valid_lft, HZ);
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if (addrconf_finite_timeout(timeout)) {
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expires = jiffies_to_clock_t(timeout * HZ);
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valid_lft = timeout;
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flags = RTF_EXPIRES;
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expires = jiffies_to_clock_t(valid_lft * HZ);
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} else {
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expires = 0;
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flags = 0;
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ifa_flags |= IFA_F_PERMANENT;
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}
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if (prefered_lft == 0)
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ifa_flags |= IFA_F_DEPRECATED;
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else if ((prefered_lft >= 0x7FFFFFFF/HZ) &&
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(prefered_lft != INFINITY_LIFE_TIME))
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prefered_lft = 0x7FFFFFFF/HZ;
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timeout = addrconf_timeout_fixup(prefered_lft, HZ);
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if (addrconf_finite_timeout(timeout)) {
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if (timeout == 0)
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ifa_flags |= IFA_F_DEPRECATED;
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prefered_lft = timeout;
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}
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spin_lock_bh(&ifp->lock);
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ifp->flags = (ifp->flags & ~(IFA_F_DEPRECATED | IFA_F_PERMANENT | IFA_F_NODAD | IFA_F_HOMEADDRESS)) | ifa_flags;
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@ -446,7 +446,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
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struct route_info *rinfo = (struct route_info *) opt;
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struct in6_addr prefix_buf, *prefix;
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unsigned int pref;
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u32 lifetime;
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unsigned long lifetime;
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struct rt6_info *rt;
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if (len < sizeof(struct route_info)) {
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@ -472,13 +472,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
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if (pref == ICMPV6_ROUTER_PREF_INVALID)
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pref = ICMPV6_ROUTER_PREF_MEDIUM;
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lifetime = ntohl(rinfo->lifetime);
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if (lifetime == 0xffffffff) {
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/* infinity */
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} else if (lifetime > 0x7fffffff/HZ - 1) {
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/* Avoid arithmetic overflow */
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lifetime = 0x7fffffff/HZ - 1;
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}
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lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
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if (rinfo->length == 3)
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prefix = (struct in6_addr *)rinfo->prefix;
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@ -506,7 +500,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
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(rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
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if (rt) {
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if (lifetime == 0xffffffff) {
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if (!addrconf_finite_timeout(lifetime)) {
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rt->rt6i_flags &= ~RTF_EXPIRES;
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} else {
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rt->rt6i_expires = jiffies + HZ * lifetime;
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