[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/include/linux/netfilter/Kbuild b/include/linux/netfilter/Kbuild
index 1e69002..707a158 100644 (file)
--- a/include/linux/netfilter/Kbuild
+++ b/include/linux/netfilter/Kbuild
@@ -10,6 +10,7 @@ header-y += xt_DSCP.h
 header-y += xt_MARK.h
 header-y += xt_NFLOG.h
 header-y += xt_NFQUEUE.h
+header-y += xt_RATEEST.h
 header-y += xt_SECMARK.h
 header-y += xt_TCPMSS.h
 header-y += xt_comment.h

diff --git a/include/linux/netfilter/xt_RATEEST.h b/include/linux/netfilter/xt_RATEEST.h
new file mode 100644 (file)
index 0000000..670f2e4
--- /dev/null
+++ b/include/linux/netfilter/xt_RATEEST.h
@@ -0,0 +1,11 @@
+#ifndef _XT_RATEEST_TARGET_H
+#define _XT_RATEEST_TARGET_H
+
+struct xt_rateest_target_info {
+       char                    name[IFNAMSIZ];
+       int8_t                  interval;
+       u_int8_t                ewma_log;
+       struct xt_rateest       *est __attribute__((aligned(8)));
+};
+
+#endif /* _XT_RATEEST_TARGET_H */

diff --git a/include/net/netfilter/xt_rateest.h b/include/net/netfilter/xt_rateest.h
new file mode 100644 (file)
index 0000000..65d594d
--- /dev/null
+++ b/include/net/netfilter/xt_rateest.h
@@ -0,0 +1,17 @@
+#ifndef _XT_RATEEST_H
+#define _XT_RATEEST_H
+
+struct xt_rateest {
+       struct hlist_node               list;
+       char                            name[IFNAMSIZ];
+       unsigned int                    refcnt;
+       spinlock_t                      lock;
+       struct gnet_estimator           params;
+       struct gnet_stats_rate_est      rstats;
+       struct gnet_stats_basic         bstats;
+};
+
+extern struct xt_rateest *xt_rateest_lookup(const char *name);
+extern void xt_rateest_put(struct xt_rateest *est);
+
+#endif /* _XT_RATEEST_H */

diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 7bde631..22d1f10 100644 (file)
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -357,6 +357,16 @@ config NETFILTER_XT_TARGET_NOTRACK
          If you want to compile it as a module, say M here and read
          <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 
+config NETFILTER_XT_TARGET_RATEEST
+       tristate '"RATEEST" target support'
+       depends on NETFILTER_XTABLES
+       help
+         This option adds a `RATEEST' target, which allows to measure
+         rates similar to TC estimators. The `rateest' match can be
+         used to match on the measured rates.
+
+         To compile it as a module, choose M here.  If unsure, say N.
+
 config NETFILTER_XT_TARGET_TRACE
        tristate  '"TRACE" target support'
        depends on NETFILTER_XTABLES

diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 28f59a3..413afaa 100644 (file)
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_MARK) += xt_MARK.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_RATEEST) += xt_RATEEST.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
 obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o

diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
new file mode 100644 (file)
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);