diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
---|---|---|
committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /net/netfilter/xt_quota.c |
Initial import
Diffstat (limited to 'net/netfilter/xt_quota.c')
-rw-r--r-- | net/netfilter/xt_quota.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/net/netfilter/xt_quota.c b/net/netfilter/xt_quota.c new file mode 100644 index 000000000..44c8eb4c9 --- /dev/null +++ b/net/netfilter/xt_quota.c @@ -0,0 +1,90 @@ +/* + * netfilter module to enforce network quotas + * + * Sam Johnston <samj@samj.net> + */ +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include <linux/netfilter/x_tables.h> +#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"); +MODULE_ALIAS("ipt_quota"); +MODULE_ALIAS("ip6t_quota"); + +static bool +quota_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + struct xt_quota_info *q = (void *)par->matchinfo; + struct xt_quota_priv *priv = q->master; + bool ret = q->flags & XT_QUOTA_INVERT; + + 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; + + if (q->flags & ~XT_QUOTA_MASK) + return -EINVAL; + + 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), + .me = THIS_MODULE, +}; + +static int __init quota_mt_init(void) +{ + return xt_register_match("a_mt_reg); +} + +static void __exit quota_mt_exit(void) +{ + xt_unregister_match("a_mt_reg); +} + +module_init(quota_mt_init); +module_exit(quota_mt_exit); |