1 files changed, 91 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/arptable_filter.c b/net/ipv4/netfilter/arptable_filter.c
new file mode 100644
index 000000000..78cd5ee24
--- /dev/null
+++ b/net/ipv4/netfilter/arptable_filter.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Filtering ARP tables module.
+ *
+ * Copyright (C) 2002 David S. Miller (davem@redhat.com)
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_arp/arp_tables.h>
+#include <linux/slab.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
+MODULE_DESCRIPTION("arptables filter table");
+
+#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
+			   (1 << NF_ARP_FORWARD))
+
+static const struct xt_table packet_filter = {
+	.name		= "filter",
+	.valid_hooks	= FILTER_VALID_HOOKS,
+	.me		= THIS_MODULE,
+	.af		= NFPROTO_ARP,
+	.priority	= NF_IP_PRI_FILTER,
+};
+
+static struct nf_hook_ops *arpfilter_ops __read_mostly;
+
+static int arptable_filter_table_init(struct net *net)
+{
+	struct arpt_replace *repl;
+	int err;
+
+	repl = arpt_alloc_initial_table(&packet_filter);
+	if (repl == NULL)
+		return -ENOMEM;
+	err = arpt_register_table(net, &packet_filter, repl, arpfilter_ops);
+	kfree(repl);
+	return err;
+}
+
+static void __net_exit arptable_filter_net_pre_exit(struct net *net)
+{
+	arpt_unregister_table_pre_exit(net, "filter");
+}
+
+static void __net_exit arptable_filter_net_exit(struct net *net)
+{
+	arpt_unregister_table(net, "filter");
+}
+
+static struct pernet_operations arptable_filter_net_ops = {
+	.exit = arptable_filter_net_exit,
+	.pre_exit = arptable_filter_net_pre_exit,
+};
+
+static int __init arptable_filter_init(void)
+{
+	int ret = xt_register_template(&packet_filter,
+				       arptable_filter_table_init);
+
+	if (ret < 0)
+		return ret;
+
+	arpfilter_ops = xt_hook_ops_alloc(&packet_filter, arpt_do_table);
+	if (IS_ERR(arpfilter_ops)) {
+		xt_unregister_template(&packet_filter);
+		return PTR_ERR(arpfilter_ops);
+	}
+
+	ret = register_pernet_subsys(&arptable_filter_net_ops);
+	if (ret < 0) {
+		xt_unregister_template(&packet_filter);
+		kfree(arpfilter_ops);
+		return ret;
+	}
+
+	return ret;
+}
+
+static void __exit arptable_filter_fini(void)
+{
+	unregister_pernet_subsys(&arptable_filter_net_ops);
+	xt_unregister_template(&packet_filter);
+	kfree(arpfilter_ops);
+}
+
+module_init(arptable_filter_init);
+module_exit(arptable_filter_fini);