Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / netfilter / xt_RATEEST.c
diff --git a/kernel/net/netfilter/xt_RATEEST.c b/kernel/net/netfilter/xt_RATEEST.c
new file mode 100644 (file)
index 0000000..604df6f
--- /dev/null
@@ -0,0 +1,194 @@
+/*
+ * (C) 2007 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#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 <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_RATEEST.h>
+#include <net/netfilter/xt_rateest.h>
+
+static DEFINE_MUTEX(xt_rateest_mutex);
+
+#define RATEEST_HSIZE  16
+static struct hlist_head rateest_hash[RATEEST_HSIZE] __read_mostly;
+static unsigned int jhash_rnd __read_mostly;
+static bool rnd_inited __read_mostly;
+
+static unsigned int xt_rateest_hash(const char *name)
+{
+       return jhash(name, FIELD_SIZEOF(struct xt_rateest, name), jhash_rnd) &
+              (RATEEST_HSIZE - 1);
+}
+
+static void xt_rateest_hash_insert(struct xt_rateest *est)
+{
+       unsigned int h;
+
+       h = xt_rateest_hash(est->name);
+       hlist_add_head(&est->list, &rateest_hash[h]);
+}
+
+struct xt_rateest *xt_rateest_lookup(const char *name)
+{
+       struct xt_rateest *est;
+       unsigned int h;
+
+       h = xt_rateest_hash(name);
+       mutex_lock(&xt_rateest_mutex);
+       hlist_for_each_entry(est, &rateest_hash[h], list) {
+               if (strcmp(est->name, name) == 0) {
+                       est->refcnt++;
+                       mutex_unlock(&xt_rateest_mutex);
+                       return est;
+               }
+       }
+       mutex_unlock(&xt_rateest_mutex);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(xt_rateest_lookup);
+
+void xt_rateest_put(struct xt_rateest *est)
+{
+       mutex_lock(&xt_rateest_mutex);
+       if (--est->refcnt == 0) {
+               hlist_del(&est->list);
+               gen_kill_estimator(&est->bstats, &est->rstats);
+               /*
+                * gen_estimator est_timer() might access est->lock or bstats,
+                * wait a RCU grace period before freeing 'est'
+                */
+               kfree_rcu(est, rcu);
+       }
+       mutex_unlock(&xt_rateest_mutex);
+}
+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_packed *stats = &info->est->bstats;
+
+       spin_lock_bh(&info->est->lock);
+       stats->bytes += skb->len;
+       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_target_info *info = par->targinfo;
+       struct xt_rateest *est;
+       struct {
+               struct nlattr           opt;
+               struct gnet_estimator   est;
+       } cfg;
+       int ret;
+
+       if (unlikely(!rnd_inited)) {
+               get_random_bytes(&jhash_rnd, sizeof(jhash_rnd));
+               rnd_inited = true;
+       }
+
+       est = xt_rateest_lookup(info->name);
+       if (est) {
+               /*
+                * 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(est);
+                       return -EINVAL;
+               }
+               info->est = est;
+               return 0;
+       }
+
+       ret = -ENOMEM;
+       est = kzalloc(sizeof(*est), GFP_KERNEL);
+       if (!est)
+               goto err1;
+
+       strlcpy(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->rstats,
+                               &est->lock, &cfg.opt);
+       if (ret < 0)
+               goto err2;
+
+       info->est = est;
+       xt_rateest_hash_insert(est);
+       return 0;
+
+err2:
+       kfree(est);
+err1:
+       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(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),
+       .me         = THIS_MODULE,
+};
+
+static int __init xt_rateest_tg_init(void)
+{
+       unsigned int i;
+
+       for (i = 0; i < ARRAY_SIZE(rateest_hash); i++)
+               INIT_HLIST_HEAD(&rateest_hash[i]);
+
+       return xt_register_target(&xt_rateest_tg_reg);
+}
+
+static void __exit xt_rateest_tg_fini(void)
+{
+       xt_unregister_target(&xt_rateest_tg_reg);
+}
+
+
+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);