From c7232c9979cba684c50b64c513c4a83c9aa70563 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sun, 26 Aug 2012 19:14:06 +0200 Subject: 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 --- net/netfilter/nf_nat_proto_sctp.c | 103 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 net/netfilter/nf_nat_proto_sctp.c (limited to 'net/netfilter/nf_nat_proto_sctp.c') diff --git a/net/netfilter/nf_nat_proto_sctp.c b/net/netfilter/nf_nat_proto_sctp.c new file mode 100644 index 000000000000..e64faa5ca893 --- /dev/null +++ b/net/netfilter/nf_nat_proto_sctp.c @@ -0,0 +1,103 @@ +/* + * Copyright (c) 2008 Patrick McHardy + * + * 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 +#include +#include +#include +#include + +#include + +static u_int16_t nf_sctp_port_rover; + +static void +sctp_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, + &nf_sctp_port_rover); +} + +static bool +sctp_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 sk_buff *frag; + sctp_sctphdr_t *hdr; + __be32 crc32; + + if (!skb_make_writable(skb, hdroff + sizeof(*hdr))) + return false; + + hdr = (struct sctphdr *)(skb->data + hdroff); + + if (maniptype == NF_NAT_MANIP_SRC) { + /* Get rid of src port */ + hdr->source = tuple->src.u.sctp.port; + } else { + /* Get rid of dst port */ + hdr->dest = tuple->dst.u.sctp.port; + } + + crc32 = sctp_start_cksum((u8 *)hdr, skb_headlen(skb) - hdroff); + skb_walk_frags(skb, frag) + crc32 = sctp_update_cksum((u8 *)frag->data, skb_headlen(frag), + crc32); + crc32 = sctp_end_cksum(crc32); + hdr->checksum = crc32; + + return true; +} + +static const struct nf_nat_l4proto nf_nat_l4proto_sctp = { + .l4proto = IPPROTO_SCTP, + .manip_pkt = sctp_manip_pkt, + .in_range = nf_nat_l4proto_in_range, + .unique_tuple = sctp_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_sctp_init(void) +{ + int err; + + err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_sctp); + if (err < 0) + goto err1; + err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_sctp); + if (err < 0) + goto err2; + return 0; + +err2: + nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_sctp); +err1: + return err; +} + +static void __exit nf_nat_proto_sctp_exit(void) +{ + nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_sctp); + nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_sctp); +} + +module_init(nf_nat_proto_sctp_init); +module_exit(nf_nat_proto_sctp_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("SCTP NAT protocol helper"); +MODULE_AUTHOR("Patrick McHardy "); -- cgit v1.2.3