projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
| Commit | Line | Data |
|---|---|---|
| 4910a087 PM |
1 | /* |
| 2 | * DCCP NAT protocol helper | |
| 3 | * | |
| 4 | * Copyright (c) 2005, 2006. 2008 Patrick McHardy <kaber@trash.net> | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | * | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/kernel.h> | |
| 13 | #include <linux/module.h> | |
| 14 | #include <linux/init.h> | |
| 15 | #include <linux/skbuff.h> | |
| 16 | #include <linux/ip.h> | |
| 17 | #include <linux/dccp.h> | |
| 18 | ||
| 19 | #include <net/netfilter/nf_conntrack.h> | |
| 20 | #include <net/netfilter/nf_nat.h> | |
| 21 | #include <net/netfilter/nf_nat_protocol.h> | |
| 22 | ||
| 23 | static u_int16_t dccp_port_rover; | |
| 24 | ||
| 25 | static int | |
| 26 | dccp_unique_tuple(struct nf_conntrack_tuple *tuple, | |
| 27 | const struct nf_nat_range *range, | |
| 28 | enum nf_nat_manip_type maniptype, | |
| 29 | const struct nf_conn *ct) | |
| 30 | { | |
| 31 | return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct, | |
| 32 | &dccp_port_rover); | |
| 33 | } | |
| 34 | ||
| 35 | static int | |
| 36 | dccp_manip_pkt(struct sk_buff *skb, | |
| 37 | unsigned int iphdroff, | |
| 38 | const struct nf_conntrack_tuple *tuple, | |
| 39 | enum nf_nat_manip_type maniptype) | |
| 40 | { | |
| 41 | struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff); | |
| 42 | struct dccp_hdr *hdr; | |
| 43 | unsigned int hdroff = iphdroff + iph->ihl * 4; | |
| 44 | __be32 oldip, newip; | |
| 45 | __be16 *portptr, oldport, newport; | |
| 46 | int hdrsize = 8; /* DCCP connection tracking guarantees this much */ | |
| 47 | ||
| 48 | if (skb->len >= hdroff + sizeof(struct dccp_hdr)) | |
| 49 | hdrsize = sizeof(struct dccp_hdr); | |
| 50 | ||
| 51 | if (!skb_make_writable(skb, hdroff + hdrsize)) | |
| 52 | return 0; | |
| 53 | ||
| 54 | iph = (struct iphdr *)(skb->data + iphdroff); | |
| 55 | hdr = (struct dccp_hdr *)(skb->data + hdroff); | |
| 56 | ||
| 57 | if (maniptype == IP_NAT_MANIP_SRC) { | |
| 58 | oldip = iph->saddr; | |
| 59 | newip = tuple->src.u3.ip; | |
| 60 | newport = tuple->src.u.dccp.port; | |
| 61 | portptr = &hdr->dccph_sport; | |
| 62 | } else { | |
| 63 | oldip = iph->daddr; | |
| 64 | newip = tuple->dst.u3.ip; | |
| 65 | newport = tuple->dst.u.dccp.port; | |
| 66 | portptr = &hdr->dccph_dport; | |
| 67 | } | |
| 68 | ||
| 69 | oldport = *portptr; | |
| 70 | *portptr = newport; | |
| 71 | ||
| 72 | if (hdrsize < sizeof(*hdr)) | |
| 73 | return 1; | |
| 74 | ||
| 75 | inet_proto_csum_replace4(&hdr->dccph_checksum, skb, oldip, newip, 1); | |
| 76 | inet_proto_csum_replace2(&hdr->dccph_checksum, skb, oldport, newport, | |
| 77 | 0); | |
| 78 | return 1; | |
| 79 | } | |
| 80 | ||
| 81 | static const struct nf_nat_protocol nf_nat_protocol_dccp = { | |
| 82 | .protonum = IPPROTO_DCCP, | |
| 83 | .me = THIS_MODULE, | |
| 84 | .manip_pkt = dccp_manip_pkt, | |
| 85 | .in_range = nf_nat_proto_in_range, | |
| 86 | .unique_tuple = dccp_unique_tuple, | |
| 87 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) | |
| 88 | .range_to_nlattr = nf_nat_proto_range_to_nlattr, | |
| 89 | .nlattr_to_range = nf_nat_proto_nlattr_to_range, | |
| 90 | #endif | |
| 91 | }; | |
| 92 | ||
| 93 | static int __init nf_nat_proto_dccp_init(void) | |
| 94 | { | |
| 95 | return nf_nat_protocol_register(&nf_nat_protocol_dccp); | |
| 96 | } | |
| 97 | ||
| 98 | static void __exit nf_nat_proto_dccp_fini(void) | |
| 99 | { | |
| 100 | nf_nat_protocol_unregister(&nf_nat_protocol_dccp); | |
| 101 | } | |
| 102 | ||
| 103 | module_init(nf_nat_proto_dccp_init); | |
| 104 | module_exit(nf_nat_proto_dccp_fini); | |
| 105 | ||
| 106 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); | |
| 107 | MODULE_DESCRIPTION("DCCP NAT protocol helper"); | |
| 108 | MODULE_LICENSE("GPL"); |