diff options
author | Patrick McHardy <kaber@trash.net> | 2012-08-26 21:14:06 +0400 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-08-30 05:00:14 +0400 |
commit | c7232c9979cba684c50b64c513c4a83c9aa70563 (patch) | |
tree | dbe0fdac62191d85935f5a3dfe815c1b1add60f9 /net/netfilter/nf_nat_proto_dccp.c | |
parent | 051966c0c644a1c96092d4206e00704ade813c9a (diff) | |
download | linux-c7232c9979cba684c50b64c513c4a83c9aa70563.tar.xz |
netfilter: add protocol independent NAT core
Convert the IPv4 NAT implementation to a protocol independent core and
address family specific modules.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter/nf_nat_proto_dccp.c')
-rw-r--r-- | net/netfilter/nf_nat_proto_dccp.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/net/netfilter/nf_nat_proto_dccp.c b/net/netfilter/nf_nat_proto_dccp.c new file mode 100644 index 000000000000..c8be2cdac0bf --- /dev/null +++ b/net/netfilter/nf_nat_proto_dccp.c @@ -0,0 +1,116 @@ +/* + * DCCP NAT protocol helper + * + * Copyright (c) 2005, 2006, 2008 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. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/dccp.h> + +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_nat.h> +#include <net/netfilter/nf_nat_l3proto.h> +#include <net/netfilter/nf_nat_l4proto.h> + +static u_int16_t dccp_port_rover; + +static void +dccp_unique_tuple(const struct nf_nat_l3proto *l3proto, + struct nf_conntrack_tuple *tuple, + const struct nf_nat_range *range, + enum nf_nat_manip_type maniptype, + const struct nf_conn *ct) +{ + nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct, + &dccp_port_rover); +} + +static bool +dccp_manip_pkt(struct sk_buff *skb, + const struct nf_nat_l3proto *l3proto, + unsigned int iphdroff, unsigned int hdroff, + const struct nf_conntrack_tuple *tuple, + enum nf_nat_manip_type maniptype) +{ + struct dccp_hdr *hdr; + __be16 *portptr, oldport, newport; + int hdrsize = 8; /* DCCP connection tracking guarantees this much */ + + if (skb->len >= hdroff + sizeof(struct dccp_hdr)) + hdrsize = sizeof(struct dccp_hdr); + + if (!skb_make_writable(skb, hdroff + hdrsize)) + return false; + + hdr = (struct dccp_hdr *)(skb->data + hdroff); + + if (maniptype == NF_NAT_MANIP_SRC) { + newport = tuple->src.u.dccp.port; + portptr = &hdr->dccph_sport; + } else { + newport = tuple->dst.u.dccp.port; + portptr = &hdr->dccph_dport; + } + + oldport = *portptr; + *portptr = newport; + + if (hdrsize < sizeof(*hdr)) + return true; + + l3proto->csum_update(skb, iphdroff, &hdr->dccph_checksum, + tuple, maniptype); + inet_proto_csum_replace2(&hdr->dccph_checksum, skb, oldport, newport, + 0); + return true; +} + +static const struct nf_nat_l4proto nf_nat_l4proto_dccp = { + .l4proto = IPPROTO_DCCP, + .manip_pkt = dccp_manip_pkt, + .in_range = nf_nat_l4proto_in_range, + .unique_tuple = dccp_unique_tuple, +#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) + .nlattr_to_range = nf_nat_l4proto_nlattr_to_range, +#endif +}; + +static int __init nf_nat_proto_dccp_init(void) +{ + int err; + + err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_dccp); + if (err < 0) + goto err1; + err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_dccp); + if (err < 0) + goto err2; + return 0; + +err2: + nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_dccp); +err1: + return err; +} + +static void __exit nf_nat_proto_dccp_fini(void) +{ + nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_dccp); + nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_dccp); + +} + +module_init(nf_nat_proto_dccp_init); +module_exit(nf_nat_proto_dccp_fini); + +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_DESCRIPTION("DCCP NAT protocol helper"); +MODULE_LICENSE("GPL"); |