netfilter: xtables: idletimer target implementation
This patch implements an idletimer Xtables target that can be used to
identify when interfaces have been idle for a certain period of time.
Timers are identified by labels and are created when a rule is set with a new
label. The rules also take a timeout value (in seconds) as an option. If
more than one rule uses the same timer label, the timer will be restarted
whenever any of the rules get a hit.
One entry for each timer is created in sysfs. This attribute contains the
timer remaining for the timer to expire. The attributes are located under
the xt_idletimer class:
/sys/class/xt_idletimer/timers/<label>
When the timer expires, the target module sends a sysfs notification to the
userspace, which can then decide what to do (eg. disconnect to save power).
Cc: Timo Teras <timo.teras@iki.fi>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 8593a77..413ed24 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -424,6 +424,18 @@
since you can easily create immortal packets that loop
forever on the network.
+config NETFILTER_XT_TARGET_IDLETIMER
+ tristate "IDLETIMER target support"
+ depends on NETFILTER_ADVANCED
+ help
+
+ This option adds the `IDLETIMER' target. Each matching packet
+ resets the timer associated with label specified when the rule is
+ added. When the timer expires, it triggers a sysfs notification.
+ The remaining time for expiration can be read via sysfs.
+
+ To compile it as a module, choose M here. If unsure, say N.
+
config NETFILTER_XT_TARGET_LED
tristate '"LED" target support'
depends on LEDS_CLASS && LEDS_TRIGGERS
