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-rw-r--r--net/netfilter/Kconfig10
-rw-r--r--net/netfilter/Makefile1
-rw-r--r--net/netfilter/xt_quota.c96
3 files changed, 107 insertions, 0 deletions
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index e2893effdfa..5543c7b7453 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -329,6 +329,16 @@ config NETFILTER_XT_MATCH_PKTTYPE
To compile it as a module, choose M here. If unsure, say N.
+config NETFILTER_XT_MATCH_QUOTA
+ tristate '"quota" match support'
+ depends on NETFILTER_XTABLES
+ help
+ This option adds a `quota' match, which allows to match on a
+ byte counter.
+
+ If you want to compile it as a module, say M here and read
+ <file:Documentation/modules.txt>. If unsure, say `N'.
+
config NETFILTER_XT_MATCH_REALM
tristate '"realm" match support'
depends on NETFILTER_XTABLES
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 95b7e416512..4b6a6ea0737 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_MARK) += xt_mark.o
obj-$(CONFIG_NETFILTER_XT_MATCH_MULTIPORT) += xt_multiport.o
obj-$(CONFIG_NETFILTER_XT_MATCH_POLICY) += xt_policy.o
obj-$(CONFIG_NETFILTER_XT_MATCH_PKTTYPE) += xt_pkttype.o
+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
diff --git a/net/netfilter/xt_quota.c b/net/netfilter/xt_quota.c
new file mode 100644
index 00000000000..4cdba7469dc
--- /dev/null
+++ b/net/netfilter/xt_quota.c
@@ -0,0 +1,96 @@
+/*
+ * netfilter module to enforce network quotas
+ *
+ * Sam Johnston <samj@samj.net>
+ */
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_quota.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sam Johnston <samj@samj.net>");
+
+static DEFINE_SPINLOCK(quota_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_quota_info *q = ((struct xt_quota_info *)matchinfo)->master;
+ int ret = q->flags & XT_QUOTA_INVERT ? 1 : 0;
+
+ spin_lock_bh(&quota_lock);
+ if (q->quota >= skb->len) {
+ q->quota -= skb->len;
+ ret ^= 1;
+ } else {
+ /* we do not allow even small packets from now on */
+ q->quota = 0;
+ }
+ spin_unlock_bh(&quota_lock);
+
+ 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_quota_info *q = (struct xt_quota_info *)matchinfo;
+
+ if (q->flags & ~XT_QUOTA_MASK)
+ return 0;
+ /* For SMP, we only want to use one set of counters. */
+ q->master = q;
+ return 1;
+}
+
+static struct xt_match quota_match = {
+ .name = "quota",
+ .family = AF_INET,
+ .match = match,
+ .matchsize = sizeof(struct xt_quota_info),
+ .checkentry = checkentry,
+ .me = THIS_MODULE
+};
+
+static struct xt_match quota_match6 = {
+ .name = "quota",
+ .family = AF_INET6,
+ .match = match,
+ .matchsize = sizeof(struct xt_quota_info),
+ .checkentry = checkentry,
+ .me = THIS_MODULE
+};
+
+static int __init xt_quota_init(void)
+{
+ int ret;
+
+ ret = xt_register_match(&quota_match);
+ if (ret)
+ goto err1;
+ ret = xt_register_match(&quota_match6);
+ if (ret)
+ goto err2;
+ return ret;
+
+err2:
+ xt_unregister_match(&quota_match);
+err1:
+ return ret;
+}
+
+static void __exit xt_quota_fini(void)
+{
+ xt_unregister_match(&quota_match6);
+ xt_unregister_match(&quota_match);
+}
+
+module_init(xt_quota_init);
+module_exit(xt_quota_fini);