1 files changed, 233 insertions, 0 deletions
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
new file mode 100644
index 000000000..80f6624e2
--- /dev/null
+++ b/net/netfilter/xt_RATEEST.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * (C) 2007 Patrick McHardy <kaber@trash.net>
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/gen_stats.h>
+#include <linux/jhash.h>
+#include <linux/rtnetlink.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <net/gen_stats.h>
+#include <net/netlink.h>
+#include <net/netns/generic.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_RATEEST.h>
+#include <net/netfilter/xt_rateest.h>
+
+#define RATEEST_HSIZE	16
+
+struct xt_rateest_net {
+	struct mutex hash_lock;
+	struct hlist_head hash[RATEEST_HSIZE];
+};
+
+static unsigned int xt_rateest_id;
+
+static unsigned int jhash_rnd __read_mostly;
+
+static unsigned int xt_rateest_hash(const char *name)
+{
+	return jhash(name, sizeof_field(struct xt_rateest, name), jhash_rnd) &
+	       (RATEEST_HSIZE - 1);
+}
+
+static void xt_rateest_hash_insert(struct xt_rateest_net *xn,
+				   struct xt_rateest *est)
+{
+	unsigned int h;
+
+	h = xt_rateest_hash(est->name);
+	hlist_add_head(&est->list, &xn->hash[h]);
+}
+
+static struct xt_rateest *__xt_rateest_lookup(struct xt_rateest_net *xn,
+					      const char *name)
+{
+	struct xt_rateest *est;
+	unsigned int h;
+
+	h = xt_rateest_hash(name);
+	hlist_for_each_entry(est, &xn->hash[h], list) {
+		if (strcmp(est->name, name) == 0) {
+			est->refcnt++;
+			return est;
+		}
+	}
+
+	return NULL;
+}
+
+struct xt_rateest *xt_rateest_lookup(struct net *net, const char *name)
+{
+	struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
+	struct xt_rateest *est;
+
+	mutex_lock(&xn->hash_lock);
+	est = __xt_rateest_lookup(xn, name);
+	mutex_unlock(&xn->hash_lock);
+	return est;
+}
+EXPORT_SYMBOL_GPL(xt_rateest_lookup);
+
+void xt_rateest_put(struct net *net, struct xt_rateest *est)
+{
+	struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
+
+	mutex_lock(&xn->hash_lock);
+	if (--est->refcnt == 0) {
+		hlist_del(&est->list);
+		gen_kill_estimator(&est->rate_est);
+		/*
+		 * gen_estimator est_timer() might access est->lock or bstats,
+		 * wait a RCU grace period before freeing 'est'
+		 */
+		kfree_rcu(est, rcu);
+	}
+	mutex_unlock(&xn->hash_lock);
+}
+EXPORT_SYMBOL_GPL(xt_rateest_put);
+
+static unsigned int
+xt_rateest_tg(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	const struct xt_rateest_target_info *info = par->targinfo;
+	struct gnet_stats_basic_sync *stats = &info->est->bstats;
+
+	spin_lock_bh(&info->est->lock);
+	u64_stats_add(&stats->bytes, skb->len);
+	u64_stats_inc(&stats->packets);
+	spin_unlock_bh(&info->est->lock);
+
+	return XT_CONTINUE;
+}
+
+static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
+{
+	struct xt_rateest_net *xn = net_generic(par->net, xt_rateest_id);
+	struct xt_rateest_target_info *info = par->targinfo;
+	struct xt_rateest *est;
+	struct {
+		struct nlattr		opt;
+		struct gnet_estimator	est;
+	} cfg;
+	int ret;
+
+	if (strnlen(info->name, sizeof(est->name)) >= sizeof(est->name))
+		return -ENAMETOOLONG;
+
+	net_get_random_once(&jhash_rnd, sizeof(jhash_rnd));
+
+	mutex_lock(&xn->hash_lock);
+	est = __xt_rateest_lookup(xn, info->name);
+	if (est) {
+		mutex_unlock(&xn->hash_lock);
+		/*
+		 * If estimator parameters are specified, they must match the
+		 * existing estimator.
+		 */
+		if ((!info->interval && !info->ewma_log) ||
+		    (info->interval != est->params.interval ||
+		     info->ewma_log != est->params.ewma_log)) {
+			xt_rateest_put(par->net, est);
+			return -EINVAL;
+		}
+		info->est = est;
+		return 0;
+	}
+
+	ret = -ENOMEM;
+	est = kzalloc(sizeof(*est), GFP_KERNEL);
+	if (!est)
+		goto err1;
+
+	gnet_stats_basic_sync_init(&est->bstats);
+	strscpy(est->name, info->name, sizeof(est->name));
+	spin_lock_init(&est->lock);
+	est->refcnt		= 1;
+	est->params.interval	= info->interval;
+	est->params.ewma_log	= info->ewma_log;
+
+	cfg.opt.nla_len		= nla_attr_size(sizeof(cfg.est));
+	cfg.opt.nla_type	= TCA_STATS_RATE_EST;
+	cfg.est.interval	= info->interval;
+	cfg.est.ewma_log	= info->ewma_log;
+
+	ret = gen_new_estimator(&est->bstats, NULL, &est->rate_est,
+				&est->lock, NULL, &cfg.opt);
+	if (ret < 0)
+		goto err2;
+
+	info->est = est;
+	xt_rateest_hash_insert(xn, est);
+	mutex_unlock(&xn->hash_lock);
+	return 0;
+
+err2:
+	kfree(est);
+err1:
+	mutex_unlock(&xn->hash_lock);
+	return ret;
+}
+
+static void xt_rateest_tg_destroy(const struct xt_tgdtor_param *par)
+{
+	struct xt_rateest_target_info *info = par->targinfo;
+
+	xt_rateest_put(par->net, info->est);
+}
+
+static struct xt_target xt_rateest_tg_reg __read_mostly = {
+	.name       = "RATEEST",
+	.revision   = 0,
+	.family     = NFPROTO_UNSPEC,
+	.target     = xt_rateest_tg,
+	.checkentry = xt_rateest_tg_checkentry,
+	.destroy    = xt_rateest_tg_destroy,
+	.targetsize = sizeof(struct xt_rateest_target_info),
+	.usersize   = offsetof(struct xt_rateest_target_info, est),
+	.me         = THIS_MODULE,
+};
+
+static __net_init int xt_rateest_net_init(struct net *net)
+{
+	struct xt_rateest_net *xn = net_generic(net, xt_rateest_id);
+	int i;
+
+	mutex_init(&xn->hash_lock);
+	for (i = 0; i < ARRAY_SIZE(xn->hash); i++)
+		INIT_HLIST_HEAD(&xn->hash[i]);
+	return 0;
+}
+
+static struct pernet_operations xt_rateest_net_ops = {
+	.init = xt_rateest_net_init,
+	.id   = &xt_rateest_id,
+	.size = sizeof(struct xt_rateest_net),
+};
+
+static int __init xt_rateest_tg_init(void)
+{
+	int err = register_pernet_subsys(&xt_rateest_net_ops);
+
+	if (err)
+		return err;
+	return xt_register_target(&xt_rateest_tg_reg);
+}
+
+static void __exit xt_rateest_tg_fini(void)
+{
+	xt_unregister_target(&xt_rateest_tg_reg);
+	unregister_pernet_subsys(&xt_rateest_net_ops);
+}
+
+
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Xtables: packet rate estimator");
+MODULE_ALIAS("ipt_RATEEST");
+MODULE_ALIAS("ip6t_RATEEST");
+module_init(xt_rateest_tg_init);
+module_exit(xt_rateest_tg_fini);