diff options
Diffstat (limited to '')
-rw-r--r-- | net/netfilter/nf_nat_tftp.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/net/netfilter/nf_nat_tftp.c b/net/netfilter/nf_nat_tftp.c new file mode 100644 index 000000000..1a591132d --- /dev/null +++ b/net/netfilter/nf_nat_tftp.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu> + */ + +#include <linux/module.h> +#include <linux/udp.h> + +#include <net/netfilter/nf_conntrack_helper.h> +#include <net/netfilter/nf_conntrack_expect.h> +#include <net/netfilter/nf_nat_helper.h> +#include <linux/netfilter/nf_conntrack_tftp.h> + +#define NAT_HELPER_NAME "tftp" + +MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>"); +MODULE_DESCRIPTION("TFTP NAT helper"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NF_NAT_HELPER(NAT_HELPER_NAME); + +static struct nf_conntrack_nat_helper nat_helper_tftp = + NF_CT_NAT_HELPER_INIT(NAT_HELPER_NAME); + +static unsigned int help(struct sk_buff *skb, + enum ip_conntrack_info ctinfo, + struct nf_conntrack_expect *exp) +{ + const 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_ct_expect_related(exp, 0) != 0) { + nf_ct_helper_log(skb, exp->master, "cannot add expectation"); + return NF_DROP; + } + return NF_ACCEPT; +} + +static void __exit nf_nat_tftp_fini(void) +{ + nf_nat_helper_unregister(&nat_helper_tftp); + RCU_INIT_POINTER(nf_nat_tftp_hook, NULL); + synchronize_rcu(); +} + +static int __init nf_nat_tftp_init(void) +{ + BUG_ON(nf_nat_tftp_hook != NULL); + nf_nat_helper_register(&nat_helper_tftp); + RCU_INIT_POINTER(nf_nat_tftp_hook, help); + return 0; +} + +module_init(nf_nat_tftp_init); +module_exit(nf_nat_tftp_fini); |