ANDROID: netfilter: xt_IDLETIMER: time-stamp and suspend/resume handling.
Message notifications contains an additional timestamp field in nano seconds.
The expiry time for the timers are modified during suspend/resume.
If timer was supposed to expire while the system is suspended then a
notification is sent when it resumes with the timestamp of the scheduled expiry.
Removes the race condition for multiple work scheduled.
Bug: 13247811
Change-Id: I752c5b00225fe7085482819f975cc0eb5af89bff
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
[AmitP: Folded following android-4.9 commit changes into this patch
13e257eaa624 ("nf: Remove compilation error caused by e8430cbed3ef15fdb1ac26cfd020e010aa5f1c35")]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
This commit is contained in:
Ruchi Kandoi
Amit Pundir
parent
1b292cb952
commit
5044acd317
1 changed files with 152 additions and 18 deletions
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@ -42,6 +42,11 @@
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#include <linux/skbuff.h>
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#include <linux/workqueue.h>
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#include <linux/sysfs.h>
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#include <linux/rtc.h>
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#include <linux/time.h>
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#include <linux/math64.h>
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#include <linux/suspend.h>
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#include <linux/notifier.h>
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#include <net/net_namespace.h>
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struct idletimer_tg_attr {
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@ -58,22 +63,65 @@ struct idletimer_tg {
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struct kobject *kobj;
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struct idletimer_tg_attr attr;
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struct timespec delayed_timer_trigger;
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struct timespec last_modified_timer;
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struct timespec last_suspend_time;
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struct notifier_block pm_nb;
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int timeout;
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unsigned int refcnt;
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bool work_pending;
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bool send_nl_msg;
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bool active;
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};
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static LIST_HEAD(idletimer_tg_list);
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static DEFINE_MUTEX(list_mutex);
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static DEFINE_SPINLOCK(timestamp_lock);
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static struct kobject *idletimer_tg_kobj;
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static bool check_for_delayed_trigger(struct idletimer_tg *timer,
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struct timespec *ts)
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{
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bool state;
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struct timespec temp;
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spin_lock_bh(×tamp_lock);
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timer->work_pending = false;
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if ((ts->tv_sec - timer->last_modified_timer.tv_sec) > timer->timeout ||
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timer->delayed_timer_trigger.tv_sec != 0) {
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state = false;
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temp.tv_sec = timer->timeout;
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temp.tv_nsec = 0;
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if (timer->delayed_timer_trigger.tv_sec != 0) {
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temp = timespec_add(timer->delayed_timer_trigger, temp);
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ts->tv_sec = temp.tv_sec;
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ts->tv_nsec = temp.tv_nsec;
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timer->delayed_timer_trigger.tv_sec = 0;
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timer->work_pending = true;
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schedule_work(&timer->work);
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} else {
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temp = timespec_add(timer->last_modified_timer, temp);
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ts->tv_sec = temp.tv_sec;
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ts->tv_nsec = temp.tv_nsec;
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}
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} else {
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state = timer->active;
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}
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spin_unlock_bh(×tamp_lock);
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return state;
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}
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static void notify_netlink_uevent(const char *iface, struct idletimer_tg *timer)
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{
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char iface_msg[NLMSG_MAX_SIZE];
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char state_msg[NLMSG_MAX_SIZE];
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char *envp[] = { iface_msg, state_msg, NULL };
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char timestamp_msg[NLMSG_MAX_SIZE];
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char *envp[] = { iface_msg, state_msg, timestamp_msg, NULL };
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int res;
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struct timespec ts;
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uint64_t time_ns;
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bool state;
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res = snprintf(iface_msg, NLMSG_MAX_SIZE, "INTERFACE=%s",
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iface);
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@ -81,12 +129,24 @@ static void notify_netlink_uevent(const char *iface, struct idletimer_tg *timer)
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pr_err("message too long (%d)", res);
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return;
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}
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get_monotonic_boottime(&ts);
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state = check_for_delayed_trigger(timer, &ts);
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res = snprintf(state_msg, NLMSG_MAX_SIZE, "STATE=%s",
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timer->active ? "active" : "inactive");
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state ? "active" : "inactive");
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if (NLMSG_MAX_SIZE <= res) {
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pr_err("message too long (%d)", res);
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return;
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}
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time_ns = timespec_to_ns(&ts);
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res = snprintf(timestamp_msg, NLMSG_MAX_SIZE, "TIME_NS=%llu", time_ns);
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if (NLMSG_MAX_SIZE <= res) {
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timestamp_msg[0] = '\0';
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pr_err("message too long (%d)", res);
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}
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pr_debug("putting nlmsg: <%s> <%s>\n", iface_msg, state_msg);
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kobject_uevent_env(idletimer_tg_kobj, KOBJ_CHANGE, envp);
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return;
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@ -151,9 +211,55 @@ static void idletimer_tg_expired(struct timer_list *t)
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struct idletimer_tg *timer = from_timer(timer, t, timer);
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pr_debug("timer %s expired\n", timer->attr.attr.name);
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spin_lock_bh(×tamp_lock);
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timer->active = false;
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timer->work_pending = true;
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schedule_work(&timer->work);
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spin_unlock_bh(×tamp_lock);
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}
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static int idletimer_resume(struct notifier_block *notifier,
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unsigned long pm_event, void *unused)
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{
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struct timespec ts;
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unsigned long time_diff, now = jiffies;
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struct idletimer_tg *timer = container_of(notifier,
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struct idletimer_tg, pm_nb);
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if (!timer)
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return NOTIFY_DONE;
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switch (pm_event) {
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case PM_SUSPEND_PREPARE:
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get_monotonic_boottime(&timer->last_suspend_time);
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break;
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case PM_POST_SUSPEND:
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spin_lock_bh(×tamp_lock);
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if (!timer->active) {
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spin_unlock_bh(×tamp_lock);
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break;
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}
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/* since jiffies are not updated when suspended now represents
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* the time it would have suspended */
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if (time_after(timer->timer.expires, now)) {
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get_monotonic_boottime(&ts);
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ts = timespec_sub(ts, timer->last_suspend_time);
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time_diff = timespec_to_jiffies(&ts);
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if (timer->timer.expires > (time_diff + now)) {
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mod_timer_pending(&timer->timer,
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(timer->timer.expires - time_diff));
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} else {
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del_timer(&timer->timer);
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timer->timer.expires = 0;
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timer->active = false;
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timer->work_pending = true;
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schedule_work(&timer->work);
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}
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}
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spin_unlock_bh(×tamp_lock);
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break;
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default:
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break;
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}
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return NOTIFY_DONE;
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}
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static int idletimer_tg_create(struct idletimer_tg_info *info)
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@ -187,6 +293,18 @@ static int idletimer_tg_create(struct idletimer_tg_info *info)
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info->timer->refcnt = 1;
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info->timer->send_nl_msg = (info->send_nl_msg == 0) ? false : true;
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info->timer->active = true;
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info->timer->timeout = info->timeout;
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info->timer->delayed_timer_trigger.tv_sec = 0;
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info->timer->delayed_timer_trigger.tv_nsec = 0;
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info->timer->work_pending = false;
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get_monotonic_boottime(&info->timer->last_modified_timer);
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info->timer->pm_nb.notifier_call = idletimer_resume;
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ret = register_pm_notifier(&info->timer->pm_nb);
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if (ret)
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printk(KERN_WARNING "[%s] Failed to register pm notifier %d\n",
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__func__, ret);
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INIT_WORK(&info->timer->work, idletimer_tg_work);
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@ -203,6 +321,34 @@ static int idletimer_tg_create(struct idletimer_tg_info *info)
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return ret;
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}
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static void reset_timer(const struct idletimer_tg_info *info)
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{
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unsigned long now = jiffies;
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struct idletimer_tg *timer = info->timer;
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bool timer_prev;
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spin_lock_bh(×tamp_lock);
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timer_prev = timer->active;
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timer->active = true;
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/* timer_prev is used to guard overflow problem in time_before*/
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if (!timer_prev || time_before(timer->timer.expires, now)) {
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pr_debug("Starting Checkentry timer (Expired, Jiffies): %lu, %lu\n",
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timer->timer.expires, now);
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/* checks if there is a pending inactive notification*/
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if (timer->work_pending)
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timer->delayed_timer_trigger = timer->last_modified_timer;
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else {
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timer->work_pending = true;
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schedule_work(&timer->work);
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}
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}
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get_monotonic_boottime(&timer->last_modified_timer);
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mod_timer(&timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + now);
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spin_unlock_bh(×tamp_lock);
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}
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/*
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* The actual xt_tables plugin.
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*/
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@ -226,9 +372,7 @@ static unsigned int idletimer_tg_target(struct sk_buff *skb,
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}
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/* TODO: Avoid modifying timers on each packet */
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + now);
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reset_timer(info);
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return XT_CONTINUE;
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}
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@ -236,7 +380,6 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
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{
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struct idletimer_tg_info *info = par->targinfo;
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int ret;
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unsigned long now = jiffies;
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pr_debug("checkentry targinfo %s\n", info->label);
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@ -260,17 +403,7 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par)
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info->timer = __idletimer_tg_find_by_label(info->label);
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if (info->timer) {
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info->timer->refcnt++;
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info->timer->active = true;
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if (time_before(info->timer->timer.expires, now)) {
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schedule_work(&info->timer->work);
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pr_debug("Starting Checkentry timer (Expired, Jiffies): %lu, %lu\n",
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info->timer->timer.expires, now);
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}
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mod_timer(&info->timer->timer,
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msecs_to_jiffies(info->timeout * 1000) + now);
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reset_timer(info);
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pr_debug("increased refcnt of timer %s to %u\n",
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info->label, info->timer->refcnt);
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} else {
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@ -302,6 +435,7 @@ static void idletimer_tg_destroy(const struct xt_tgdtor_param *par)
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del_timer_sync(&info->timer->timer);
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cancel_work_sync(&info->timer->work);
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sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr);
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unregister_pm_notifier(&info->timer->pm_nb);
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kfree(info->timer->attr.attr.name);
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kfree(info->timer);
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} else {
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