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author | 2012-08-26 19:14:06 +0200 | |
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committer | 2012-08-30 03:00:14 +0200 | |
commit | c7232c9979cba684c50b64c513c4a83c9aa70563 (patch) | |
tree | dbe0fdac62191d85935f5a3dfe815c1b1add60f9 /net/netfilter/nf_nat_proto_udplite.c | |
parent | netfilter: nf_nat: add protoff argument to packet mangling functions (diff) | |
download | linux-c7232c9979cba684c50b64c513c4a83c9aa70563.tar.gz linux-c7232c9979cba684c50b64c513c4a83c9aa70563.tar.bz2 linux-c7232c9979cba684c50b64c513c4a83c9aa70563.zip |
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_udplite.c')
-rw-r--r-- | net/netfilter/nf_nat_proto_udplite.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/net/netfilter/nf_nat_proto_udplite.c b/net/netfilter/nf_nat_proto_udplite.c new file mode 100644 index 000000000000..776a0d1317b1 --- /dev/null +++ b/net/netfilter/nf_nat_proto_udplite.c @@ -0,0 +1,106 @@ +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> + * (C) 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/types.h> +#include <linux/init.h> +#include <linux/udp.h> + +#include <linux/netfilter.h> +#include <linux/module.h> +#include <net/netfilter/nf_nat.h> +#include <net/netfilter/nf_nat_l3proto.h> +#include <net/netfilter/nf_nat_l4proto.h> + +static u16 udplite_port_rover; + +static void +udplite_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, + &udplite_port_rover); +} + +static bool +udplite_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 udphdr *hdr; + __be16 *portptr, newport; + + if (!skb_make_writable(skb, hdroff + sizeof(*hdr))) + return false; + + hdr = (struct udphdr *)(skb->data + hdroff); + + if (maniptype == NF_NAT_MANIP_SRC) { + /* Get rid of source port */ + newport = tuple->src.u.udp.port; + portptr = &hdr->source; + } else { + /* Get rid of dst port */ + newport = tuple->dst.u.udp.port; + portptr = &hdr->dest; + } + + l3proto->csum_update(skb, iphdroff, &hdr->check, tuple, maniptype); + inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, 0); + if (!hdr->check) + hdr->check = CSUM_MANGLED_0; + + *portptr = newport; + return true; +} + +static const struct nf_nat_l4proto nf_nat_l4proto_udplite = { + .l4proto = IPPROTO_UDPLITE, + .manip_pkt = udplite_manip_pkt, + .in_range = nf_nat_l4proto_in_range, + .unique_tuple = udplite_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_udplite_init(void) +{ + int err; + + err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_udplite); + if (err < 0) + goto err1; + err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_udplite); + if (err < 0) + goto err2; + return 0; + +err2: + nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite); +err1: + return err; +} + +static void __exit nf_nat_proto_udplite_fini(void) +{ + nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_udplite); + nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_udplite); +} + +module_init(nf_nat_proto_udplite_init); +module_exit(nf_nat_proto_udplite_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("UDP-Lite NAT protocol helper"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |