[NETFILTER]: x_tables: add RATEEST target
Add new rate estimator target (using gen_estimator). In combination with
the rateest match (next patch) this can be used for load-based multipath
routing.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
new file mode 100644
index 0000000..c008883
--- /dev/null
+++ b/net/netfilter/xt_RATEEST.c
@@ -0,0 +1,204 @@
+/*
+ * (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 <net/gen_stats.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 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;
+ struct hlist_node *n;
+ unsigned int h;
+
+ h = xt_rateest_hash(name);
+ mutex_lock(&xt_rateest_mutex);
+ hlist_for_each_entry(est, n, &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);
+ kfree(est);
+ }
+ mutex_unlock(&xt_rateest_mutex);
+}
+EXPORT_SYMBOL_GPL(xt_rateest_put);
+
+static unsigned int
+xt_rateest_tg(struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const struct xt_target *target,
+ const void *targinfo)
+{
+ const struct xt_rateest_target_info *info = targinfo;
+ struct gnet_stats_basic *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 bool
+xt_rateest_tg_checkentry(const char *tablename,
+ const void *entry,
+ const struct xt_target *target,
+ void *targinfo,
+ unsigned int hook_mask)
+{
+ struct xt_rateest_target_info *info = (void *)targinfo;
+ struct xt_rateest *est;
+ struct {
+ struct rtattr opt;
+ struct gnet_estimator est;
+ } cfg;
+
+ 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 false;
+ }
+ info->est = est;
+ return true;
+ }
+
+ 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.rta_len = RTA_LENGTH(sizeof(cfg.est));
+ cfg.opt.rta_type = TCA_STATS_RATE_EST;
+ cfg.est.interval = info->interval;
+ cfg.est.ewma_log = info->ewma_log;
+
+ if (gen_new_estimator(&est->bstats, &est->rstats, &est->lock,
+ &cfg.opt) < 0)
+ goto err2;
+
+ info->est = est;
+ xt_rateest_hash_insert(est);
+
+ return true;
+
+err2:
+ kfree(est);
+err1:
+ return false;
+}
+
+static void xt_rateest_tg_destroy(const struct xt_target *target,
+ void *targinfo)
+{
+ struct xt_rateest_target_info *info = targinfo;
+
+ xt_rateest_put(info->est);
+}
+
+static struct xt_target xt_rateest_target[] __read_mostly = {
+ {
+ .family = AF_INET,
+ .name = "RATEEST",
+ .target = xt_rateest_tg,
+ .checkentry = xt_rateest_tg_checkentry,
+ .destroy = xt_rateest_tg_destroy,
+ .targetsize = sizeof(struct xt_rateest_target_info),
+ .me = THIS_MODULE,
+ },
+ {
+ .family = AF_INET6,
+ .name = "RATEEST",
+ .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]);
+
+ get_random_bytes(&jhash_rnd, sizeof(jhash_rnd));
+ return xt_register_targets(xt_rateest_target,
+ ARRAY_SIZE(xt_rateest_target));
+}
+
+static void __exit xt_rateest_tg_fini(void)
+{
+ xt_unregister_targets(xt_rateest_target, ARRAY_SIZE(xt_rateest_target));
+}
+
+
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("xtables rate estimator");
+MODULE_ALIAS("ipt_RATEEST");
+MODULE_ALIAS("ip6t_RATEEST");
+module_init(xt_rateest_tg_init);
+module_exit(xt_rateest_tg_fini);