ipv6 addrconf: Allow infinite prefix lifetime.

We need to handle infinite prefix lifetime specially.
With help from original reporter "Bonitch, Joseph"
<Joseph.Bonitch@xerox.com>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8dd9155..3a83557 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1764,14 +1764,16 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
         *      2) Configure prefixes with the auto flag set
         */
 
-       /* 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.
-        */
-       if (valid_lft >= 0x7FFFFFFF/HZ)
+       if (valid_lft == INFINITY_LIFE_TIME)
+               rt_expires = ~0UL;
+       else if (valid_lft >= 0x7FFFFFFF/HZ) {
+               /* 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
+       } else
                rt_expires = valid_lft * HZ;
 
        /*
@@ -1779,7 +1781,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
         * Avoid arithmetic overflow there as well.
         * Overflow can happen only if HZ < USER_HZ.
         */
-       if (HZ < USER_HZ && rt_expires > 0x7FFFFFFF / USER_HZ)
+       if (HZ < USER_HZ && ~rt_expires && rt_expires > 0x7FFFFFFF / USER_HZ)
                rt_expires = 0x7FFFFFFF / USER_HZ;
 
        if (pinfo->onlink) {
@@ -1788,17 +1790,28 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
                                dev->ifindex, 1);
 
                if (rt && ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0)) {
-                       if (rt->rt6i_flags&RTF_EXPIRES) {
-                               if (valid_lft == 0) {
-                                       ip6_del_rt(rt);
-                                       rt = NULL;
-                               } else {
-                                       rt->rt6i_expires = jiffies + rt_expires;
-                               }
+                       /* Autoconf prefix route */
+                       if (valid_lft == 0) {
+                               ip6_del_rt(rt);
+                               rt = NULL;
+                       } else if (~rt_expires) {
+                               /* not infinity */
+                               rt->rt6i_expires = jiffies + rt_expires;
+                               rt->rt6i_flags |= RTF_EXPIRES;
+                       } else {
+                               rt->rt6i_flags &= ~RTF_EXPIRES;
+                               rt->rt6i_expires = 0;
                        }
                } else if (valid_lft) {
+                       int flags = RTF_ADDRCONF | RTF_PREFIX_RT;
+                       clock_t expires = 0;
+                       if (~rt_expires) {
+                               /* not infinity */
+                               flags |= RTF_EXPIRES;
+                               expires = jiffies_to_clock_t(rt_expires);
+                       }
                        addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
-                                             dev, jiffies_to_clock_t(rt_expires), RTF_ADDRCONF|RTF_EXPIRES|RTF_PREFIX_RT);
+                                             dev, expires, flags);
                }
                if (rt)
                        dst_release(&rt->u.dst);
@@ -2021,7 +2034,8 @@ static int inet6_addr_add(struct net *net, int ifindex, struct in6_addr *pfx,
        struct inet6_dev *idev;
        struct net_device *dev;
        int scope;
-       u32 flags = RTF_EXPIRES;
+       u32 flags;
+       clock_t expires;
 
        ASSERT_RTNL();
 
@@ -2041,8 +2055,13 @@ static int inet6_addr_add(struct net *net, int ifindex, struct in6_addr *pfx,
        if (valid_lft == INFINITY_LIFE_TIME) {
                ifa_flags |= IFA_F_PERMANENT;
                flags = 0;
-       } else if (valid_lft >= 0x7FFFFFFF/HZ)
-               valid_lft = 0x7FFFFFFF/HZ;
+               expires = 0;
+       } else {
+               if (valid_lft >= 0x7FFFFFFF/HZ)
+                       valid_lft = 0x7FFFFFFF/HZ;
+               flags = RTF_EXPIRES;
+               expires = jiffies_to_clock_t(valid_lft * HZ);
+       }
 
        if (prefered_lft == 0)
                ifa_flags |= IFA_F_DEPRECATED;
@@ -2060,7 +2079,7 @@ static int inet6_addr_add(struct net *net, int ifindex, struct in6_addr *pfx,
                spin_unlock_bh(&ifp->lock);
 
                addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev,
-                                     jiffies_to_clock_t(valid_lft * HZ), flags);
+                                     expires, flags);
                /*
                 * Note that section 3.1 of RFC 4429 indicates
                 * that the Optimistic flag should not be set for
@@ -3148,7 +3167,8 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
                             u32 prefered_lft, u32 valid_lft)
 {
-       u32 flags = RTF_EXPIRES;
+       u32 flags;
+       clock_t expires;
 
        if (!valid_lft || (prefered_lft > valid_lft))
                return -EINVAL;
@@ -3156,8 +3176,13 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
        if (valid_lft == INFINITY_LIFE_TIME) {
                ifa_flags |= IFA_F_PERMANENT;
                flags = 0;
-       } else if (valid_lft >= 0x7FFFFFFF/HZ)
-               valid_lft = 0x7FFFFFFF/HZ;
+               expires = 0;
+       } else {
+               if (valid_lft >= 0x7FFFFFFF/HZ)
+                       valid_lft = 0x7FFFFFFF/HZ;
+               flags = RTF_EXPIRES;
+               expires = jiffies_to_clock_t(valid_lft * HZ);
+       }
 
        if (prefered_lft == 0)
                ifa_flags |= IFA_F_DEPRECATED;
@@ -3176,7 +3201,7 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u8 ifa_flags,
                ipv6_ifa_notify(0, ifp);
 
        addrconf_prefix_route(&ifp->addr, ifp->prefix_len, ifp->idev->dev,
-                             jiffies_to_clock_t(valid_lft * HZ), flags);
+                             expires, flags);
        addrconf_verify(0);
 
        return 0;

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b45a7c0..b7a4a87 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1106,7 +1106,9 @@ int ip6_route_add(struct fib6_config *cfg)
        }
 
        rt->u.dst.obsolete = -1;
-       rt->rt6i_expires = jiffies + clock_t_to_jiffies(cfg->fc_expires);
+       rt->rt6i_expires = (cfg->fc_flags & RTF_EXPIRES) ?
+                               jiffies + clock_t_to_jiffies(cfg->fc_expires) :
+                               0;
 
        if (cfg->fc_protocol == RTPROT_UNSPEC)
                cfg->fc_protocol = RTPROT_BOOT;