diff options
| -rw-r--r-- | include/linux/netfilter/xt_statistic.h | 32 | ||||
| -rw-r--r-- | net/netfilter/Kconfig | 6 | ||||
| -rw-r--r-- | net/netfilter/Makefile | 1 | ||||
| -rw-r--r-- | net/netfilter/xt_statistic.c | 112 |
4 files changed, 151 insertions, 0 deletions
diff --git a/include/linux/netfilter/xt_statistic.h b/include/linux/netfilter/xt_statistic.h new file mode 100644 index 00000000000..c344e9916e2 --- /dev/null +++ b/include/linux/netfilter/xt_statistic.h @@ -0,0 +1,32 @@ +#ifndef _XT_STATISTIC_H +#define _XT_STATISTIC_H + +enum xt_statistic_mode { + XT_STATISTIC_MODE_RANDOM, + XT_STATISTIC_MODE_NTH, + __XT_STATISTIC_MODE_MAX +}; +#define XT_STATISTIC_MODE_MAX (__XT_STATISTIC_MODE_MAX - 1) + +enum xt_statistic_flags { + XT_STATISTIC_INVERT = 0x1, +}; +#define XT_STATISTIC_MASK 0x1 + +struct xt_statistic_info { + u_int16_t mode; + u_int16_t flags; + union { + struct { + u_int32_t probability; + } random; + struct { + u_int32_t every; + u_int32_t packet; + u_int32_t count; + } nth; + } u; + struct xt_statistic_info *master __attribute__((aligned(8))); +}; + +#endif /* _XT_STATISTIC_H */ diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 5543c7b7453..85a7e177025 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -375,6 +375,12 @@ config NETFILTER_XT_MATCH_STATE To compile it as a module, choose M here. If unsure, say N. +config NETFILTER_XT_MATCH_STATISTIC + tristate '"statistic" match support' + depends on NETFILTER_XTABLES + help + statistic module + config NETFILTER_XT_MATCH_STRING tristate '"string" match support' depends on NETFILTER_XTABLES diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 4b6a6ea0737..df1da25f40d 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -48,6 +48,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_QUOTA) += xt_quota.o obj-$(CONFIG_NETFILTER_XT_MATCH_REALM) += xt_realm.o obj-$(CONFIG_NETFILTER_XT_MATCH_SCTP) += xt_sctp.o obj-$(CONFIG_NETFILTER_XT_MATCH_STATE) += xt_state.o +obj-$(CONFIG_NETFILTER_XT_MATCH_STATISTIC) += xt_statistic.o obj-$(CONFIG_NETFILTER_XT_MATCH_STRING) += xt_string.o obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o obj-$(CONFIG_NETFILTER_XT_MATCH_PHYSDEV) += xt_physdev.o diff --git a/net/netfilter/xt_statistic.c b/net/netfilter/xt_statistic.c new file mode 100644 index 00000000000..de1037f5859 --- /dev/null +++ b/net/netfilter/xt_statistic.c @@ -0,0 +1,112 @@ +/* + * Copyright (c) 2006 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. + * + * Based on ipt_random and ipt_nth by Fabrice MARIE <fabrice@netfilter.org>. + */ + +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/skbuff.h> +#include <linux/net.h> + +#include <linux/netfilter/xt_statistic.h> +#include <linux/netfilter/x_tables.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_DESCRIPTION("xtables statistical match module"); +MODULE_ALIAS("ipt_statistic"); +MODULE_ALIAS("ip6t_statistic"); + +static DEFINE_SPINLOCK(nth_lock); + +static int +match(const struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + const struct xt_match *match, const void *matchinfo, + int offset, unsigned int protoff, int *hotdrop) +{ + struct xt_statistic_info *info = (struct xt_statistic_info *)matchinfo; + int ret = info->flags & XT_STATISTIC_INVERT ? 1 : 0; + + switch (info->mode) { + case XT_STATISTIC_MODE_RANDOM: + if ((net_random() & 0x7FFFFFFF) < info->u.random.probability) + ret ^= 1; + break; + case XT_STATISTIC_MODE_NTH: + info = info->master; + spin_lock_bh(&nth_lock); + if (info->u.nth.count++ == info->u.nth.every) { + info->u.nth.count = 0; + ret ^= 1; + } + spin_unlock_bh(&nth_lock); + break; + } + + return ret; +} + +static int +checkentry(const char *tablename, const void *entry, + const struct xt_match *match, void *matchinfo, + unsigned int matchsize, unsigned int hook_mask) +{ + struct xt_statistic_info *info = (struct xt_statistic_info *)matchinfo; + + if (info->mode > XT_STATISTIC_MODE_MAX || + info->flags & ~XT_STATISTIC_MASK) + return 0; + info->master = info; + return 1; +} + +static struct xt_match statistic_match = { + .name = "statistic", + .match = match, + .matchsize = sizeof(struct xt_statistic_info), + .checkentry = checkentry, + .family = AF_INET, + .me = THIS_MODULE, +}; + +static struct xt_match statistic_match6 = { + .name = "statistic", + .match = match, + .matchsize = sizeof(struct xt_statistic_info), + .checkentry = checkentry, + .family = AF_INET6, + .me = THIS_MODULE, +}; + +static int __init xt_statistic_init(void) +{ + int ret; + + ret = xt_register_match(&statistic_match); + if (ret) + goto err1; + + ret = xt_register_match(&statistic_match6); + if (ret) + goto err2; + return ret; +err2: + xt_unregister_match(&statistic_match); +err1: + return ret; +} + +static void __exit xt_statistic_fini(void) +{ + xt_unregister_match(&statistic_match6); + xt_unregister_match(&statistic_match); +} + +module_init(xt_statistic_init); +module_exit(xt_statistic_fini); |