[PATCH 1/1] ipv6 addrconf:fix preferred lifetime state-changing behavior while valid_lft is infinity

[yazzep@gmail.com]

From: Yasushi Asano <yasushi.asano@jp.fujitsu.com>

 Fixed a problem with setting the lifetime of an IPv6
 address. When setting preferred_lft to a value not zero or
 infinity, while valid_lft is infinity(0xffffffff) preferred
 lifetime is set to forever and does not update. Therefore
 preferred lifetime never becomes deprecated. valid lifetime
 and preferred lifetime should be set independently, even if
 valid lifetime is infinity, preferred lifetime must expire
 correctly (meaning it must eventually become deprecated)


Signed-off-by: Yasushi Asano <yasushi.asano@jp.fujitsu.com>
---
 net/ipv6/addrconf.c |   34 ++++++++++++++++++++--------------
 1 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3c3425e..17b4097 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -948,18 +948,22 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
 					if (!onlink)
 						onlink = -1;
 
-					spin_lock(&ifa->lock);
-
-					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;
-					spin_unlock(&ifa->lock);
+					if (ifp->valid_lft !=
+						INFINITY_LIFE_TIME) {
+						spin_lock(&ifa->lock);
+
+						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;
+						spin_unlock(&ifa->lock);
+					}
 				}
 			}
 		}
@@ -2415,7 +2419,6 @@ static int inet6_addr_add(struct net *net, int ifindex,
 	} else {
 		expires = 0;
 		flags = 0;
-		ifa_flags |= IFA_F_PERMANENT;
 	}
 
 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);
@@ -3497,8 +3500,12 @@ restart:
 					ifp->flags |= IFA_F_DEPRECATED;
 				}
 
-				if (time_before(ifp->tstamp + ifp->valid_lft * HZ, next))
-					next = ifp->tstamp + ifp->valid_lft * HZ;
+				if (ifp->valid_lft != INFINITY_LIFE_TIME) {
+					if (time_before(ifp->tstamp +
+							ifp->valid_lft * HZ, next))
+						next = ifp->tstamp +
+							ifp->valid_lft * HZ;
+				}
 
 				spin_unlock(&ifp->lock);
 
@@ -3635,7 +3642,6 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 ifa_flags,
 	} else {
 		expires = 0;
 		flags = 0;
-		ifa_flags |= IFA_F_PERMANENT;
 	}
 
 	timeout = addrconf_timeout_fixup(prefered_lft, HZ);