From: Ruchi Kandoi Date: Tue, 25 Mar 2014 23:43:28 +0000 (-0700) Subject: ANDROID: netfilter: xt_IDLETIMER: time-stamp and suspend/resume handling. X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=9a741d176df1e0fff440fb4a30e7635052cc7073;p=android-x86%2Fkernel.git 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 [AmitP: Folded following android-4.9 commit changes into this patch 13e257eaa624 ("nf: Remove compilation error caused by e8430cbed3ef15fdb1ac26cfd020e010aa5f1c35")] Signed-off-by: Amit Pundir --- diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c index c76e5d4b088a..25a021a9d8ef 100644 --- a/net/netfilter/xt_IDLETIMER.c +++ b/net/netfilter/xt_IDLETIMER.c @@ -42,6 +42,11 @@ #include #include #include +#include +#include +#include +#include +#include #include struct idletimer_tg_attr { @@ -58,22 +63,65 @@ struct idletimer_tg { struct kobject *kobj; struct idletimer_tg_attr attr; + struct timespec delayed_timer_trigger; + struct timespec last_modified_timer; + struct timespec last_suspend_time; + struct notifier_block pm_nb; + + int timeout; unsigned int refcnt; + bool work_pending; bool send_nl_msg; bool active; }; static LIST_HEAD(idletimer_tg_list); static DEFINE_MUTEX(list_mutex); +static DEFINE_SPINLOCK(timestamp_lock); static struct kobject *idletimer_tg_kobj; +static bool check_for_delayed_trigger(struct idletimer_tg *timer, + struct timespec *ts) +{ + bool state; + struct timespec temp; + spin_lock_bh(×tamp_lock); + timer->work_pending = false; + if ((ts->tv_sec - timer->last_modified_timer.tv_sec) > timer->timeout || + timer->delayed_timer_trigger.tv_sec != 0) { + state = false; + temp.tv_sec = timer->timeout; + temp.tv_nsec = 0; + if (timer->delayed_timer_trigger.tv_sec != 0) { + temp = timespec_add(timer->delayed_timer_trigger, temp); + ts->tv_sec = temp.tv_sec; + ts->tv_nsec = temp.tv_nsec; + timer->delayed_timer_trigger.tv_sec = 0; + timer->work_pending = true; + schedule_work(&timer->work); + } else { + temp = timespec_add(timer->last_modified_timer, temp); + ts->tv_sec = temp.tv_sec; + ts->tv_nsec = temp.tv_nsec; + } + } else { + state = timer->active; + } + spin_unlock_bh(×tamp_lock); + return state; +} + static void notify_netlink_uevent(const char *iface, struct idletimer_tg *timer) { char iface_msg[NLMSG_MAX_SIZE]; char state_msg[NLMSG_MAX_SIZE]; - char *envp[] = { iface_msg, state_msg, NULL }; + char timestamp_msg[NLMSG_MAX_SIZE]; + char *envp[] = { iface_msg, state_msg, timestamp_msg, NULL }; int res; + struct timespec ts; + uint64_t time_ns; + bool state; res = snprintf(iface_msg, NLMSG_MAX_SIZE, "INTERFACE=%s", iface); @@ -81,12 +129,24 @@ static void notify_netlink_uevent(const char *iface, struct idletimer_tg *timer) pr_err("message too long (%d)", res); return; } + + get_monotonic_boottime(&ts); + state = check_for_delayed_trigger(timer, &ts); res = snprintf(state_msg, NLMSG_MAX_SIZE, "STATE=%s", - timer->active ? "active" : "inactive"); + state ? "active" : "inactive"); + if (NLMSG_MAX_SIZE <= res) { pr_err("message too long (%d)", res); return; } + + time_ns = timespec_to_ns(&ts); + res = snprintf(timestamp_msg, NLMSG_MAX_SIZE, "TIME_NS=%llu", time_ns); + if (NLMSG_MAX_SIZE <= res) { + timestamp_msg[0] = '\0'; + pr_err("message too long (%d)", res); + } + pr_debug("putting nlmsg: <%s> <%s>\n", iface_msg, state_msg); kobject_uevent_env(idletimer_tg_kobj, KOBJ_CHANGE, envp); return; @@ -151,9 +211,55 @@ static void idletimer_tg_expired(struct timer_list *t) struct idletimer_tg *timer = from_timer(timer, t, timer); pr_debug("timer %s expired\n", timer->attr.attr.name); - + spin_lock_bh(×tamp_lock); timer->active = false; + timer->work_pending = true; schedule_work(&timer->work); + spin_unlock_bh(×tamp_lock); +} + +static int idletimer_resume(struct notifier_block *notifier, + unsigned long pm_event, void *unused) +{ + struct timespec ts; + unsigned long time_diff, now = jiffies; + struct idletimer_tg *timer = container_of(notifier, + struct idletimer_tg, pm_nb); + if (!timer) + return NOTIFY_DONE; + switch (pm_event) { + case PM_SUSPEND_PREPARE: + get_monotonic_boottime(&timer->last_suspend_time); + break; + case PM_POST_SUSPEND: + spin_lock_bh(×tamp_lock); + if (!timer->active) { + spin_unlock_bh(×tamp_lock); + break; + } + /* since jiffies are not updated when suspended now represents + * the time it would have suspended */ + if (time_after(timer->timer.expires, now)) { + get_monotonic_boottime(&ts); + ts = timespec_sub(ts, timer->last_suspend_time); + time_diff = timespec_to_jiffies(&ts); + if (timer->timer.expires > (time_diff + now)) { + mod_timer_pending(&timer->timer, + (timer->timer.expires - time_diff)); + } else { + del_timer(&timer->timer); + timer->timer.expires = 0; + timer->active = false; + timer->work_pending = true; + schedule_work(&timer->work); + } + } + spin_unlock_bh(×tamp_lock); + break; + default: + break; + } + return NOTIFY_DONE; } static int idletimer_tg_create(struct idletimer_tg_info *info) @@ -187,6 +293,18 @@ static int idletimer_tg_create(struct idletimer_tg_info *info) info->timer->refcnt = 1; info->timer->send_nl_msg = (info->send_nl_msg == 0) ? false : true; info->timer->active = true; + info->timer->timeout = info->timeout; + + info->timer->delayed_timer_trigger.tv_sec = 0; + info->timer->delayed_timer_trigger.tv_nsec = 0; + info->timer->work_pending = false; + get_monotonic_boottime(&info->timer->last_modified_timer); + + info->timer->pm_nb.notifier_call = idletimer_resume; + ret = register_pm_notifier(&info->timer->pm_nb); + if (ret) + printk(KERN_WARNING "[%s] Failed to register pm notifier %d\n", + __func__, ret); INIT_WORK(&info->timer->work, idletimer_tg_work); @@ -203,6 +321,34 @@ out: return ret; } +static void reset_timer(const struct idletimer_tg_info *info) +{ + unsigned long now = jiffies; + struct idletimer_tg *timer = info->timer; + bool timer_prev; + + spin_lock_bh(×tamp_lock); + timer_prev = timer->active; + timer->active = true; + /* timer_prev is used to guard overflow problem in time_before*/ + if (!timer_prev || time_before(timer->timer.expires, now)) { + pr_debug("Starting Checkentry timer (Expired, Jiffies): %lu, %lu\n", + timer->timer.expires, now); + /* checks if there is a pending inactive notification*/ + if (timer->work_pending) + timer->delayed_timer_trigger = timer->last_modified_timer; + else { + timer->work_pending = true; + schedule_work(&timer->work); + } + } + + get_monotonic_boottime(&timer->last_modified_timer); + mod_timer(&timer->timer, + msecs_to_jiffies(info->timeout * 1000) + now); + spin_unlock_bh(×tamp_lock); +} + /* * The actual xt_tables plugin. */ @@ -226,9 +372,7 @@ static unsigned int idletimer_tg_target(struct sk_buff *skb, } /* TODO: Avoid modifying timers on each packet */ - mod_timer(&info->timer->timer, - msecs_to_jiffies(info->timeout * 1000) + now); - + reset_timer(info); return XT_CONTINUE; } @@ -236,7 +380,6 @@ 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); @@ -260,17 +403,7 @@ 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) + now); - + reset_timer(info); pr_debug("increased refcnt of timer %s to %u\n", info->label, info->timer->refcnt); } else { @@ -302,6 +435,7 @@ static void idletimer_tg_destroy(const struct xt_tgdtor_param *par) del_timer_sync(&info->timer->timer); cancel_work_sync(&info->timer->work); sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr); + unregister_pm_notifier(&info->timer->pm_nb); kfree(info->timer->attr.attr.name); kfree(info->timer); } else {