From 469a150b7426d4c4b0663d6fa7dfaa0cd0b4448e Mon Sep 17 00:00:00 2001
From: Bhavya Sokke Mallikarjunappa <bsokke@codeaurora.org>
Date: Fri, 20 Jun 2014 17:17:17 -0700
Subject: netfilter: xtables: hardidletimer target implementation

This patch implements a hardidletimer 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_hardidletimer/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)

Compared to xt_IDLETIMER, xt_HARDIDLETIMER can send notifications when CPU
is in suspend too, to notify the timer expiry

Change-Id: I1723d44e02df864d63da7550766ea7d763076de2
Signed-off-by: Bhavya Sokke Mallikarjunappa <bsokke@codeaurora.org>
---
 include/uapi/linux/netfilter/xt_HARDIDLETIMER.h | 55 +++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 include/uapi/linux/netfilter/xt_HARDIDLETIMER.h

(limited to 'include/uapi')

diff --git a/include/uapi/linux/netfilter/xt_HARDIDLETIMER.h b/include/uapi/linux/netfilter/xt_HARDIDLETIMER.h
new file mode 100644
index 000000000000..58ff60899cd2
--- /dev/null
+++ b/include/uapi/linux/netfilter/xt_HARDIDLETIMER.h
@@ -0,0 +1,55 @@
+/*
+ * linux/include/linux/netfilter/xt_HARDIDLETIMER.h
+ *
+ * Header file for Xtables timer target module.
+ *
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * Copyright (C) 2004, 2010 Nokia Corporation
+ *
+ * Written by Timo Teras <ext-timo.teras@nokia.com>
+ *
+ * Converted to x_tables and forward-ported to 2.6.34
+ * by Luciano Coelho <luciano.coelho@nokia.com>
+ *
+ * Contact: Luciano Coelho <luciano.coelho@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef _XT_HARDIDLETIMER_H
+#define _XT_HARDIDLETIMER_H
+
+#include <linux/types.h>
+
+#define MAX_HARDIDLETIMER_LABEL_SIZE 28
+#define NLMSG_MAX_SIZE 64
+
+#define NL_EVENT_TYPE_INACTIVE 0
+#define NL_EVENT_TYPE_ACTIVE 1
+
+struct hardidletimer_tg_info {
+	__u32 timeout;
+
+	char label[MAX_HARDIDLETIMER_LABEL_SIZE];
+
+	/* Use netlink messages for notification in addition to sysfs */
+	__u8 send_nl_msg;
+
+	/* for kernel module internal use only */
+	struct hardidletimer_tg *timer __attribute__((aligned(8)));
+};
+
+#endif
-- 
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