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>

1 files changed, 49 insertions, 24 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8dd9155502b5..3a835578fd1c 100644
--- 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;