1 files changed, 31 insertions, 4 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8c1e86afbbf..43b3c9f89c1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1916,8 +1916,32 @@ ok:
                                         update_lft = 1;
                                 else if (stored_lft <= MIN_VALID_LIFETIME) {
                                         /* valid_lft <= stored_lft is always true */
-                                        /* XXX: IPsec */
-                                        update_lft = 0;
+                                        /*
+                                         * RFC 4862 Section 5.5.3e:
+                                         * "Note that the preferred lifetime of
+                                         *  the corresponding address is always
+                                         *  reset to the Preferred Lifetime in
+                                         *  the received Prefix Information
+                                         *  option, regardless of whether the
+                                         *  valid lifetime is also reset or
+                                         *  ignored."
+                                         *
+                                         *  So if the preferred lifetime in
+                                         *  this advertisement is different
+                                         *  than what we have stored, but the
+                                         *  valid lifetime is invalid, just
+                                         *  reset prefered_lft.
+                                         *
+                                         *  We must set the valid lifetime
+                                         *  to the stored lifetime since we'll
+                                         *  be updating the timestamp below,
+                                         *  else we'll set it back to the
+                                         *  minumum.
+                                         */
+                                        if (prefered_lft != ifp->prefered_lft) {
+                                                valid_lft = stored_lft;
+                                                update_lft = 1;
+                                        }
                                 } else {
                                         valid_lft = MIN_VALID_LIFETIME;
                                         if (valid_lft < prefered_lft)
@@ -3085,7 +3109,7 @@ restart:
                                 spin_unlock(&ifp->lock);
                                 continue;
                         } else if (age >= ifp->prefered_lft) {
-                                /* jiffies - ifp->tsamp > age >= ifp->prefered_lft */
+                                /* jiffies - ifp->tstamp > age >= ifp->prefered_lft */
                                 int deprecate = 0;
 
                                 if (!(ifp->flags&IFA_F_DEPRECATED)) {
@@ -3362,7 +3386,10 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
                 valid = ifa->valid_lft;
                 if (preferred != INFINITY_LIFE_TIME) {
                         long tval = (jiffies - ifa->tstamp)/HZ;
-                        preferred -= tval;
+                        if (preferred > tval)
+                                preferred -= tval;
+                        else
+                                preferred = 0;
                         if (valid != INFINITY_LIFE_TIME)
                                 valid -= tval;
                 }