diff --git a/include/uapi/linux/netfilter/xt_IDLETIMER.h b/include/uapi/linux/netfilter/xt_IDLETIMER.h index 3c586a19baea..434e6506abaa 100644 --- a/include/uapi/linux/netfilter/xt_IDLETIMER.h +++ b/include/uapi/linux/netfilter/xt_IDLETIMER.h @@ -1,4 +1,3 @@ -/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ /* * linux/include/linux/netfilter/xt_IDLETIMER.h * @@ -33,6 +32,7 @@ #include #define MAX_IDLETIMER_LABEL_SIZE 28 +#define XT_IDLETIMER_ALARM 0x01 struct idletimer_tg_info { __u32 timeout; @@ -43,4 +43,14 @@ struct idletimer_tg_info { struct idletimer_tg *timer __attribute__((aligned(8))); }; +struct idletimer_tg_info_v1 { + __u32 timeout; + + char label[MAX_IDLETIMER_LABEL_SIZE]; + + __u8 timer_type; + + /* for kernel module internal use only */ + struct idletimer_tg *timer __attribute__((aligned(8))); +}; #endif diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c index f56d3ed93e56..d620bbf13b30 100644 --- a/net/netfilter/xt_IDLETIMER.c +++ b/net/netfilter/xt_IDLETIMER.c @@ -18,6 +18,7 @@ #include #include +#include #include #include #include @@ -30,6 +31,7 @@ struct idletimer_tg { struct list_head entry; + struct alarm alarm; struct timer_list timer; struct work_struct work; @@ -37,6 +39,7 @@ struct idletimer_tg { struct device_attribute attr; unsigned int refcnt; + u8 timer_type; }; static LIST_HEAD(idletimer_tg_list); @@ -62,20 +65,30 @@ static ssize_t idletimer_tg_show(struct device *dev, { struct idletimer_tg *timer; unsigned long expires = 0; + struct timespec64 ktimespec = {}; + long time_diff = 0; mutex_lock(&list_mutex); timer = __idletimer_tg_find_by_label(attr->attr.name); - if (timer) + if (timer) { + if (timer->timer_type & XT_IDLETIMER_ALARM) { + ktime_t expires_alarm = alarm_expires_remaining(&timer->alarm); + ktimespec = ktime_to_timespec64(expires_alarm); + time_diff = ktimespec.tv_sec; + } else { expires = timer->timer.expires; + time_diff = jiffies_to_msecs( + expires - jiffies) / 1000; + } + } mutex_unlock(&list_mutex); - if (time_after(expires, jiffies)) - return sprintf(buf, "%u\n", - jiffies_to_msecs(expires - jiffies) / 1000); + if (time_after(expires, jiffies) || ktimespec.tv_sec > 0) + return snprintf(buf, PAGE_SIZE, "%ld\n", time_diff); - return sprintf(buf, "0\n"); + return snprintf(buf, PAGE_SIZE, "0\n"); } static void idletimer_tg_work(struct work_struct *work) @@ -95,6 +108,16 @@ static void idletimer_tg_expired(struct timer_list *t) schedule_work(&timer->work); } +static enum alarmtimer_restart idletimer_tg_alarmproc(struct alarm *alarm, + ktime_t now) +{ + struct idletimer_tg *timer = alarm->data; + + pr_debug("alarm %s expired\n", timer->attr.attr.name); + schedule_work(&timer->work); + return ALARMTIMER_NORESTART; +} + static int idletimer_check_sysfs_name(const char *name, unsigned int size) { int ret; @@ -160,6 +183,68 @@ static int idletimer_tg_create(struct idletimer_tg_info *info) return ret; } +static int idletimer_tg_create_v1(struct idletimer_tg_info_v1 *info) +{ + int ret; + + info->timer = kmalloc(sizeof(*info->timer), GFP_KERNEL); + if (!info->timer) { + ret = -ENOMEM; + goto out; + } + + ret = idletimer_check_sysfs_name(info->label, sizeof(info->label)); + if (ret < 0) + goto out_free_timer; + + sysfs_attr_init(&info->timer->attr.attr); + info->timer->attr.attr.name = kstrdup(info->label, GFP_KERNEL); + if (!info->timer->attr.attr.name) { + ret = -ENOMEM; + goto out_free_timer; + } + info->timer->attr.attr.mode = 0444; + info->timer->attr.show = idletimer_tg_show; + + ret = sysfs_create_file(idletimer_tg_kobj, &info->timer->attr.attr); + if (ret < 0) { + pr_debug("couldn't add file to sysfs"); + goto out_free_attr; + } + + /* notify userspace */ + kobject_uevent(idletimer_tg_kobj,KOBJ_ADD); + + list_add(&info->timer->entry, &idletimer_tg_list); + pr_debug("timer type value is %u", info->timer_type); + info->timer->timer_type = info->timer_type; + info->timer->refcnt = 1; + + INIT_WORK(&info->timer->work, idletimer_tg_work); + + if (info->timer->timer_type & XT_IDLETIMER_ALARM) { + ktime_t tout; + alarm_init(&info->timer->alarm, ALARM_BOOTTIME, + idletimer_tg_alarmproc); + info->timer->alarm.data = info->timer; + tout = ktime_set(info->timeout, 0); + alarm_start_relative(&info->timer->alarm, tout); + } else { + timer_setup(&info->timer->timer, idletimer_tg_expired, 0); + mod_timer(&info->timer->timer, + msecs_to_jiffies(info->timeout * 1000) + jiffies); + } + + return 0; + +out_free_attr: + kfree(info->timer->attr.attr.name); +out_free_timer: + kfree(info->timer); +out: + return ret; +} + /* * The actual xt_tables plugin. */ @@ -177,13 +262,30 @@ static unsigned int idletimer_tg_target(struct sk_buff *skb, return XT_CONTINUE; } -static int idletimer_tg_checkentry(const struct xt_tgchk_param *par) +/* + * The actual xt_tables plugin. + */ +static unsigned int idletimer_tg_target_v1(struct sk_buff *skb, + const struct xt_action_param *par) { - struct idletimer_tg_info *info = par->targinfo; - int ret; + const struct idletimer_tg_info_v1 *info = par->targinfo; - pr_debug("checkentry targinfo%s\n", info->label); + pr_debug("resetting timer %s, timeout period %u\n", + info->label, info->timeout); + if (info->timer->timer_type & XT_IDLETIMER_ALARM) { + ktime_t tout = ktime_set(info->timeout, 0); + alarm_start_relative(&info->timer->alarm, tout); + } else { + mod_timer(&info->timer->timer, + msecs_to_jiffies(info->timeout * 1000) + jiffies); + } + + return XT_CONTINUE; +} + +static int idletimer_tg_helper(struct idletimer_tg_info *info) +{ if (info->timeout == 0) { pr_debug("timeout value is zero\n"); return -EINVAL; @@ -198,7 +300,23 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par) pr_debug("label is empty or not nul-terminated\n"); return -EINVAL; } + return 0; +} + +static int idletimer_tg_checkentry(const struct xt_tgchk_param *par) +{ + struct idletimer_tg_info *info = par->targinfo; + int ret; + + pr_debug("checkentry targinfo%s\n", info->label); + + ret = idletimer_tg_helper(info); + if(ret < 0) + { + pr_debug("checkentry helper return invalid\n"); + return -EINVAL; + } mutex_lock(&list_mutex); info->timer = __idletimer_tg_find_by_label(info->label); @@ -222,6 +340,65 @@ static int idletimer_tg_checkentry(const struct xt_tgchk_param *par) return 0; } +static int idletimer_tg_checkentry_v1(const struct xt_tgchk_param *par) +{ + struct idletimer_tg_info_v1 *info = par->targinfo; + int ret; + + pr_debug("checkentry targinfo%s\n", info->label); + + ret = idletimer_tg_helper((struct idletimer_tg_info *)info); + if(ret < 0) + { + pr_debug("checkentry helper return invalid\n"); + return -EINVAL; + } + + if (info->timer_type > XT_IDLETIMER_ALARM) { + pr_debug("invalid value for timer type\n"); + return -EINVAL; + } + + mutex_lock(&list_mutex); + + info->timer = __idletimer_tg_find_by_label(info->label); + if (info->timer) { + if (info->timer->timer_type != info->timer_type) { + pr_debug("Adding/Replacing rule with same label and different timer type is not allowed\n"); + mutex_unlock(&list_mutex); + return -EINVAL; + } + + info->timer->refcnt++; + if (info->timer_type & XT_IDLETIMER_ALARM) { + /* calculate remaining expiry time */ + ktime_t tout = alarm_expires_remaining(&info->timer->alarm); + struct timespec64 ktimespec = ktime_to_timespec64(tout); + + if (ktimespec.tv_sec > 0) { + pr_debug("time_expiry_remaining %lld\n", + ktimespec.tv_sec); + alarm_start_relative(&info->timer->alarm, tout); + } + } else { + mod_timer(&info->timer->timer, + msecs_to_jiffies(info->timeout * 1000) + jiffies); + } + pr_debug("increased refcnt of timer %s to %u\n", + info->label, info->timer->refcnt); + } else { + ret = idletimer_tg_create_v1(info); + if (ret < 0) { + pr_debug("failed to create timer\n"); + mutex_unlock(&list_mutex); + return ret; + } + } + + mutex_unlock(&list_mutex); + return 0; +} + static void idletimer_tg_destroy(const struct xt_tgdtor_param *par) { const struct idletimer_tg_info *info = par->targinfo; @@ -247,7 +424,38 @@ static void idletimer_tg_destroy(const struct xt_tgdtor_param *par) mutex_unlock(&list_mutex); } -static struct xt_target idletimer_tg __read_mostly = { +static void idletimer_tg_destroy_v1(const struct xt_tgdtor_param *par) +{ + const struct idletimer_tg_info_v1 *info = par->targinfo; + + pr_debug("destroy targinfo %s\n", info->label); + + mutex_lock(&list_mutex); + + if (--info->timer->refcnt == 0) { + pr_debug("deleting timer %s\n", info->label); + + list_del(&info->timer->entry); + if (info->timer->timer_type & XT_IDLETIMER_ALARM) { + alarm_cancel(&info->timer->alarm); + } else { + del_timer_sync(&info->timer->timer); + } + cancel_work_sync(&info->timer->work); + sysfs_remove_file(idletimer_tg_kobj, &info->timer->attr.attr); + kfree(info->timer->attr.attr.name); + kfree(info->timer); + } else { + pr_debug("decreased refcnt of timer %s to %u\n", + info->label, info->timer->refcnt); + } + + mutex_unlock(&list_mutex); +} + + +static struct xt_target idletimer_tg[] __read_mostly = { + { .name = "IDLETIMER", .family = NFPROTO_UNSPEC, .target = idletimer_tg_target, @@ -256,6 +464,20 @@ static struct xt_target idletimer_tg __read_mostly = { .checkentry = idletimer_tg_checkentry, .destroy = idletimer_tg_destroy, .me = THIS_MODULE, + }, + { + .name = "IDLETIMER", + .family = NFPROTO_UNSPEC, + .revision = 1, + .target = idletimer_tg_target_v1, + .targetsize = sizeof(struct idletimer_tg_info_v1), + .usersize = offsetof(struct idletimer_tg_info_v1, timer), + .checkentry = idletimer_tg_checkentry_v1, + .destroy = idletimer_tg_destroy_v1, + .me = THIS_MODULE, + }, + + }; static struct class *idletimer_tg_class; @@ -283,7 +505,8 @@ static int __init idletimer_tg_init(void) idletimer_tg_kobj = &idletimer_tg_device->kobj; - err = xt_register_target(&idletimer_tg); + err = xt_register_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg)); + if (err < 0) { pr_debug("couldn't register xt target\n"); goto out_dev; @@ -300,7 +523,7 @@ static int __init idletimer_tg_init(void) static void __exit idletimer_tg_exit(void) { - xt_unregister_target(&idletimer_tg); + xt_unregister_targets(idletimer_tg, ARRAY_SIZE(idletimer_tg)); device_destroy(idletimer_tg_class, MKDEV(0, 0)); class_destroy(idletimer_tg_class);