diff mbox

[3.8,009/133] ipv6: Avoid unnecessary temporary addresses being generated

Message ID 1398197671-12786-10-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa April 22, 2014, 8:12 p.m. UTC 
3.8.13.22 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Heiner Kallweit <heiner.kallweit@web.de>

[ Upstream commit ecab67015ef6e3f3635551dcc9971cf363cc1cd5 ]

tmp_prefered_lft is an offset to ifp->tstamp, not now. Therefore
age needs to be added to the condition.

Age calculation in ipv6_create_tempaddr is different from the one
in addrconf_verify and doesn't consider ADDRCONF_TIMER_FUZZ_MINUS.
This can cause age in ipv6_create_tempaddr to be less than the one
in addrconf_verify and therefore unnecessary temporary address to
be generated.
Use age calculation as in addrconf_modify to avoid this.

Signed-off-by: Heiner Kallweit <heiner.kallweit@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 net/ipv6/addrconf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index e169782..c724838 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1033,8 +1033,11 @@  retry:
 	 * Lifetime is greater than REGEN_ADVANCE time units.  In particular,
 	 * an implementation must not create a temporary address with a zero
 	 * Preferred Lifetime.
+	 * Use age calculation as in addrconf_verify to avoid unnecessary
+	 * temporary addresses being generated.
 	 */
-	if (tmp_prefered_lft <= regen_advance) {
+	age = (now - tmp_tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;
+	if (tmp_prefered_lft <= regen_advance + age) {
 		in6_ifa_put(ifp);
 		in6_dev_put(idev);
 		ret = -1;