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xt_IDLETIMER:

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Add new netlink msg type for IDLETIMER.

Send notifications when the label becomes active after an idle period.
Send netlink message notifications in addition to sysfs notifications.

Change-Id: I31677ef00c94b5f82c8457e5bf9e5e584c23c523
Signed-off-by: Ashish Sharma <ashishsharma@google.com>
This commit is contained in:
Ashish Sharma 2012-03-29 13:02:27 -07:00 committed by JP Abgrall
parent 4991496393
commit beb914e987
3 changed files with 107 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
include/linux/netfilter/xt_IDLETIMER.h
View File

@ -4,6 +4,7 @@
* Header file for Xtables timer target module.
*
* 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
@ -32,12 +33,19 @@
#include <linux/types.h>
#define MAX_IDLETIMER_LABEL_SIZE 28
#define NLMSG_MAX_SIZE 64
#define NL_EVENT_TYPE_INACTIVE 0
#define NL_EVENT_TYPE_ACTIVE 1
struct idletimer_tg_info {
__u32 timeout;
char label[MAX_IDLETIMER_LABEL_SIZE];
/* Use netlink messages for notification in addition to sysfs */
__u8 send_nl_msg;
/* for kernel module internal use only */
struct idletimer_tg *timer __attribute__((aligned(8)));
};

1
include/linux/netlink.h
View File

@ -25,6 +25,7 @@
#define NETLINK_SCSITRANSPORT 18 /* SCSI Transports */
#define NETLINK_ECRYPTFS 19
#define NETLINK_RDMA 20
#define NETLINK_IDLETIMER 21
#define MAX_LINKS 32

105
net/netfilter/xt_IDLETIMER.c
View File

@ -5,6 +5,7 @@
* After timer expires a kevent will be sent.
*
* Copyright (C) 2004, 2010 Nokia Corporation
*
* Written by Timo Teras <ext-timo.teras@nokia.com>
*
* Converted to x_tables and reworked for upstream inclusion
@ -36,10 +37,15 @@
#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_IDLETIMER.h>
#include <linux/netlink.h>
#include <linux/kdev_t.h>
#include <linux/kobject.h>
#include <linux/skbuff.h>
#include <linux/workqueue.h>
#include <linux/sysfs.h>
#include <net/net_namespace.h>
static struct sock *nl_sk;
struct idletimer_tg_attr {
struct attribute attr;
@ -56,6 +62,8 @@ struct idletimer_tg {
struct idletimer_tg_attr attr;
unsigned int refcnt;
bool send_nl_msg;
bool active;
};
static LIST_HEAD(idletimer_tg_list);
@ -63,6 +71,46 @@ static DEFINE_MUTEX(list_mutex);
static struct kobject *idletimer_tg_kobj;
static void notify_netlink(const char *iface, struct idletimer_tg *timer)
{
struct sk_buff *log_skb;
size_t size;
struct nlmsghdr *nlh;
char str[NLMSG_MAX_SIZE];
int event_type, res;
size = NLMSG_SPACE(NLMSG_MAX_SIZE);
size = max(size, (size_t)NLMSG_GOODSIZE);
log_skb = alloc_skb(size, GFP_ATOMIC);
if (!log_skb) {
pr_err("xt_cannot alloc skb for logging\n");
return;
}
event_type = timer->active ? NL_EVENT_TYPE_ACTIVE
: NL_EVENT_TYPE_INACTIVE;
res = snprintf(str, NLMSG_MAX_SIZE, "%s %s\n", iface,
timer->active ? "ACTIVE" : "INACTIVE");
if (NLMSG_MAX_SIZE <= res)
goto nlmsg_failure;
/* NLMSG_PUT() uses "goto nlmsg_failure" */
nlh = NLMSG_PUT(log_skb, /*pid*/0, /*seq*/0, event_type,
/* Size of message */NLMSG_MAX_SIZE);
strncpy(NLMSG_DATA(nlh), str, MAX_IDLETIMER_LABEL_SIZE);
NETLINK_CB(log_skb).dst_group = 1;
netlink_broadcast(nl_sk, log_skb, 0, 1, GFP_ATOMIC);
pr_debug("putting nlmsg: %s", str);
return;
nlmsg_failure: /* Used within NLMSG_PUT() */
consume_skb(log_skb);
pr_debug("Failed nlmsg_put\n");
}
static
struct idletimer_tg *__idletimer_tg_find_by_label(const char *label)
{
@ -83,6 +131,7 @@ static ssize_t idletimer_tg_show(struct kobject *kobj, struct attribute *attr,
{
struct idletimer_tg *timer;
unsigned long expires = 0;
unsigned long now = jiffies;
mutex_lock(&list_mutex);
@ -92,11 +141,15 @@ static ssize_t idletimer_tg_show(struct kobject *kobj, struct attribute *attr,
mutex_unlock(&list_mutex);
if (time_after(expires, jiffies))
if (time_after(expires, now))
return sprintf(buf, "%u\n",
jiffies_to_msecs(expires - jiffies) / 1000);
jiffies_to_msecs(expires - now) / 1000);
return sprintf(buf, "0\n");
if (timer->send_nl_msg)
return sprintf(buf, "0 %d\n",
jiffies_to_msecs(now - expires) / 1000);
else
return sprintf(buf, "0\n");
}
static void idletimer_tg_work(struct work_struct *work)
@ -105,6 +158,9 @@ static void idletimer_tg_work(struct work_struct *work)
work);
sysfs_notify(idletimer_tg_kobj, NULL, timer->attr.attr.name);
if (timer->send_nl_msg)
notify_netlink(timer->attr.attr.name, timer);
}
static void idletimer_tg_expired(unsigned long data)
@ -113,6 +169,7 @@ static void idletimer_tg_expired(unsigned long data)
pr_debug("timer %s expired\n", timer->attr.attr.name);
timer->active = false;
schedule_work(&timer->work);
}
@ -147,6 +204,8 @@ static int idletimer_tg_create(struct idletimer_tg_info *info)
setup_timer(&info->timer->timer, idletimer_tg_expired,
(unsigned long) info->timer);
info->timer->refcnt = 1;
info->timer->send_nl_msg = (info->send_nl_msg == 0) ? false : true;
info->timer->active = true;
mod_timer(&info->timer->timer,
msecs_to_jiffies(info->timeout * 1000) + jiffies);
@ -170,14 +229,24 @@ static unsigned int idletimer_tg_target(struct sk_buff *skb,
const struct xt_action_param *par)
{
const struct idletimer_tg_info *info = par->targinfo;
unsigned long now = jiffies;
pr_debug("resetting timer %s, timeout period %u\n",
info->label, info->timeout);
BUG_ON(!info->timer);
info->timer->active = true;
if (time_before(info->timer->timer.expires, now)) {
schedule_work(&info->timer->work);
pr_debug("Starting timer %s (Expired, Jiffies): %lu, %lu\n",
info->label, info->timer->timer.expires, now);
}
/* TODO: Avoid modifying timers on each packet */
mod_timer(&info->timer->timer,
msecs_to_jiffies(info->timeout * 1000) + jiffies);
msecs_to_jiffies(info->timeout * 1000) + now);
return XT_CONTINUE;
}
@ -186,8 +255,9 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
{
struct idletimer_tg_info *info = par->targinfo;
int ret;
unsigned long now = jiffies;
pr_debug("checkentry targinfo%s\n", info->label);
pr_debug("checkentry targinfo %s\n", info->label);
if (info->timeout == 0) {
pr_debug("timeout value is zero\n");
@ -206,8 +276,17 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
info->timer = __idletimer_tg_find_by_label(info->label);
if (info->timer) {
info->timer->refcnt++;
info->timer->active = true;
if (time_before(info->timer->timer.expires, now)) {
schedule_work(&info->timer->work);
pr_debug("Starting Checkentry timer"
"(Expired, Jiffies): %lu, %lu\n",
info->timer->timer.expires, now);
}
mod_timer(&info->timer->timer,
msecs_to_jiffies(info->timeout * 1000) + jiffies);
msecs_to_jiffies(info->timeout * 1000) + now);
pr_debug("increased refcnt of timer %s to %u\n",
info->label, info->timer->refcnt);
@ -221,6 +300,7 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
}
mutex_unlock(&list_mutex);
return 0;
}
@ -242,7 +322,7 @@ static void idletimer_tg_destroy(const struct xt_tgdtor_param *par)
kfree(info->timer);
} else {
pr_debug("decreased refcnt of timer %s to %u\n",
info->label, info->timer->refcnt);
info->label, info->timer->refcnt);
}
mutex_unlock(&list_mutex);
@ -250,6 +330,7 @@ static void idletimer_tg_destroy(const struct xt_tgdtor_param *par)
static struct xt_target idletimer_tg __read_mostly = {
.name = "IDLETIMER",
.revision = 1,
.family = NFPROTO_UNSPEC,
.target = idletimer_tg_target,
.targetsize = sizeof(struct idletimer_tg_info),
@ -289,6 +370,15 @@ static int __init idletimer_tg_init(void)
goto out_dev;
}
nl_sk = netlink_kernel_create(&init_net,
NETLINK_IDLETIMER, 1, NULL,
NULL, THIS_MODULE);
if (!nl_sk) {
pr_err("Failed to create netlink socket\n");
return -ENOMEM;
}
return 0;
out_dev:
device_destroy(idletimer_tg_class, MKDEV(0, 0));
@ -315,3 +405,4 @@ MODULE_DESCRIPTION("Xtables: idle time monitor");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("ipt_IDLETIMER");
MODULE_ALIAS("ip6t_IDLETIMER");
MODULE_ALIAS("arpt_IDLETIMER");