[NETFILTER]: nf_conntrack/nf_nat: add TFTP helper port
Add IPv4 and IPv6 capable nf_conntrack port of the TFTP conntrack/NAT helper.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/nf_nat_tftp.c b/net/ipv4/netfilter/nf_nat_tftp.c
new file mode 100644
index 0000000..2566b79
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_tftp.c
@@ -0,0 +1,52 @@
+/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
+ *
+ * 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/moduleparam.h>
+#include <linux/udp.h>
+
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_tftp.h>
+
+MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
+MODULE_DESCRIPTION("TFTP NAT helper");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_nat_tftp");
+
+static unsigned int help(struct sk_buff **pskb,
+ enum ip_conntrack_info ctinfo,
+ struct nf_conntrack_expect *exp)
+{
+ struct nf_conn *ct = exp->master;
+
+ exp->saved_proto.udp.port
+ = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;
+ exp->dir = IP_CT_DIR_REPLY;
+ exp->expectfn = nf_nat_follow_master;
+ if (nf_conntrack_expect_related(exp) != 0)
+ return NF_DROP;
+ return NF_ACCEPT;
+}
+
+static void __exit nf_nat_tftp_fini(void)
+{
+ rcu_assign_pointer(nf_nat_tftp_hook, NULL);
+ synchronize_rcu();
+}
+
+static int __init nf_nat_tftp_init(void)
+{
+ BUG_ON(rcu_dereference(nf_nat_tftp_hook));
+ rcu_assign_pointer(nf_nat_tftp_hook, help);
+ return 0;
+}
+
+module_init(nf_nat_tftp_init);
+module_exit(nf_nat_tftp_fini);