Revert "netfilter: xt_quota: fix the behavior of xt_quota module" (af510ebd) · Commits · 戴 / test

include/uapi/linux/netfilter/xt_quota.h

+3 −5

Original line number	Diff line number	Diff line
		@@ -15,11 +15,9 @@ struct xt_quota_info {
		__u32 flags;
		__u32 pad;
		__aligned_u64 quota;
		#ifdef __KERNEL__
		atomic64_t counter;
		#else
		__aligned_u64 remain;
		#endif

		/* Used internally by the kernel */
		struct xt_quota_priv *master;
		};

		#endif /* _XT_QUOTA_H */

net/netfilter/xt_quota.c

+33 −22

Original line number	Diff line number	Diff line
		@@ -11,6 +11,11 @@
		#include <linux/netfilter/xt_quota.h>
		#include <linux/module.h>

		struct xt_quota_priv {
		spinlock_t lock;
		uint64_t quota;
		};

		MODULE_LICENSE("GPL");
		MODULE_AUTHOR("Sam Johnston <samj@samj.net>");
		MODULE_DESCRIPTION("Xtables: countdown quota match");
		@@ -21,48 +26,54 @@ static bool
		quota_mt(const struct sk_buff skb, struct xt_action_param par)
		{
		struct xt_quota_info q = (void )par->matchinfo;
		u64 current_count = atomic64_read(&q->counter);
		struct xt_quota_priv *priv = q->master;
		bool ret = q->flags & XT_QUOTA_INVERT;
		u64 old_count, new_count;

		do {
		if (current_count == 1)
		return ret;
		if (current_count <= skb->len) {
		atomic64_set(&q->counter, 1);
		return ret;
		spin_lock_bh(&priv->lock);
		if (priv->quota >= skb->len) {
		priv->quota -= skb->len;
		ret = !ret;
		} else {
		/* we do not allow even small packets from now on */
		priv->quota = 0;
		}
		old_count = current_count;
		new_count = current_count - skb->len;
		current_count = atomic64_cmpxchg(&q->counter, old_count,
		new_count);
		} while (current_count != old_count);
		return !ret;
		spin_unlock_bh(&priv->lock);

		return ret;
		}

		static int quota_mt_check(const struct xt_mtchk_param *par)
		{
		struct xt_quota_info *q = par->matchinfo;

		BUILD_BUG_ON(sizeof(atomic64_t) != sizeof(__u64));

		if (q->flags & ~XT_QUOTA_MASK)
		return -EINVAL;
		if (atomic64_read(&q->counter) > q->quota + 1)
		return -ERANGE;

		if (atomic64_read(&q->counter) == 0)
		atomic64_set(&q->counter, q->quota + 1);
		q->master = kmalloc(sizeof(*q->master), GFP_KERNEL);
		if (q->master == NULL)
		return -ENOMEM;

		spin_lock_init(&q->master->lock);
		q->master->quota = q->quota;
		return 0;
		}

		static void quota_mt_destroy(const struct xt_mtdtor_param *par)
		{
		const struct xt_quota_info *q = par->matchinfo;

		kfree(q->master);
		}

		static struct xt_match quota_mt_reg __read_mostly = {
		.name = "quota",
		.revision = 0,
		.family = NFPROTO_UNSPEC,
		.match = quota_mt,
		.checkentry = quota_mt_check,
		.destroy = quota_mt_destroy,
		.matchsize = sizeof(struct xt_quota_info),
		.usersize = offsetof(struct xt_quota_info, master),
		.me = THIS_MODULE,
		};

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