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Revert "netfilter: xt_quota: fix the behavior of xt_quota module" 

This reverts commit e9837e55b0.

When talking to Maze and Chenbo, we agreed to keep this back by now
due to problems in the ruleset listing path with 32-bit arches.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
hifive-unleashed-5.1
Pablo Neira Ayuso 2018-10-19 11:48:24 +02:00
parent 468c041cff
commit af510ebd89
2 changed files with 35 additions and 26 deletions
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8
include/uapi/linux/netfilter/xt_quota.h
View File

@ -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 */

53
net/netfilter/xt_quota.c
View File

@ -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;
}
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_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;
}
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,
};