0808dc8093
Noticed by Jesper Dangaard Brouer Signed-off-by: David S. Miller <davem@davemloft.net>
98 lines
2.6 KiB
C
98 lines
2.6 KiB
C
/*
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* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/ip.h>
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#include <linux/sctp.h>
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#include <net/sctp/checksum.h>
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#include <net/netfilter/nf_nat_protocol.h>
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static u_int16_t nf_sctp_port_rover;
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static bool
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sctp_unique_tuple(struct nf_conntrack_tuple *tuple,
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const struct nf_nat_range *range,
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enum nf_nat_manip_type maniptype,
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const struct nf_conn *ct)
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{
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return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
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&nf_sctp_port_rover);
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}
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static bool
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sctp_manip_pkt(struct sk_buff *skb,
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unsigned int iphdroff,
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const struct nf_conntrack_tuple *tuple,
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enum nf_nat_manip_type maniptype)
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{
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const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
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struct sk_buff *frag;
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sctp_sctphdr_t *hdr;
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unsigned int hdroff = iphdroff + iph->ihl*4;
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__be32 oldip, newip;
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__be32 crc32;
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if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
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return false;
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iph = (struct iphdr *)(skb->data + iphdroff);
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hdr = (struct sctphdr *)(skb->data + hdroff);
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if (maniptype == IP_NAT_MANIP_SRC) {
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/* Get rid of src ip and src pt */
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oldip = iph->saddr;
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newip = tuple->src.u3.ip;
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hdr->source = tuple->src.u.sctp.port;
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} else {
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/* Get rid of dst ip and dst pt */
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oldip = iph->daddr;
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newip = tuple->dst.u3.ip;
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hdr->dest = tuple->dst.u.sctp.port;
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}
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crc32 = sctp_start_cksum((u8 *)hdr, skb_headlen(skb) - hdroff);
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skb_walk_frags(skb, frag)
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crc32 = sctp_update_cksum((u8 *)frag->data, skb_headlen(frag),
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crc32);
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crc32 = sctp_end_cksum(crc32);
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hdr->checksum = crc32;
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return true;
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}
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static const struct nf_nat_protocol nf_nat_protocol_sctp = {
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.protonum = IPPROTO_SCTP,
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.me = THIS_MODULE,
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.manip_pkt = sctp_manip_pkt,
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.in_range = nf_nat_proto_in_range,
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.unique_tuple = sctp_unique_tuple,
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#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
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.range_to_nlattr = nf_nat_proto_range_to_nlattr,
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.nlattr_to_range = nf_nat_proto_nlattr_to_range,
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#endif
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};
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static int __init nf_nat_proto_sctp_init(void)
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{
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return nf_nat_protocol_register(&nf_nat_protocol_sctp);
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}
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static void __exit nf_nat_proto_sctp_exit(void)
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{
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nf_nat_protocol_unregister(&nf_nat_protocol_sctp);
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}
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module_init(nf_nat_proto_sctp_init);
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module_exit(nf_nat_proto_sctp_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("SCTP NAT protocol helper");
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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