From 4910a087996e637adc50f955eccf114307f8fab7 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Thu, 20 Mar 2008 15:15:57 +0100 Subject: [PATCH] [NETFILTER]: nf_nat: add DCCP protocol support Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/Kconfig | 5 ++ net/ipv4/netfilter/Makefile | 1 + net/ipv4/netfilter/nf_nat_proto_dccp.c | 108 +++++++++++++++++++++++++++++++++ net/ipv4/netfilter/nf_nat_standalone.c | 6 +- 4 files changed, 118 insertions(+), 2 deletions(-) create mode 100644 net/ipv4/netfilter/nf_nat_proto_dccp.c diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index c5bd284..fde3eac 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -241,6 +241,11 @@ config NF_NAT_SNMP_BASIC # '&&' (6) # # (6) Returns the result of min(/expr/, /expr/). +config NF_NAT_PROTO_DCCP + tristate + depends on NF_NAT && NF_CT_PROTO_DCCP + default NF_NAT && NF_CT_PROTO_DCCP + config NF_NAT_PROTO_GRE tristate depends on NF_NAT && NF_CT_PROTO_GRE diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index 332f46f..74d8dbd 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o # NAT protocols (nf_nat) +obj-$(CONFIG_NF_NAT_PROTO_DCCP) += nf_nat_proto_dccp.o obj-$(CONFIG_NF_NAT_PROTO_GRE) += nf_nat_proto_gre.o obj-$(CONFIG_NF_NAT_PROTO_UDPLITE) += nf_nat_proto_udplite.o diff --git a/net/ipv4/netfilter/nf_nat_proto_dccp.c b/net/ipv4/netfilter/nf_nat_proto_dccp.c new file mode 100644 index 0000000..12b51b3 --- /dev/null +++ b/net/ipv4/netfilter/nf_nat_proto_dccp.c @@ -0,0 +1,108 @@ +/* + * DCCP NAT protocol helper + * + * Copyright (c) 2005, 2006. 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 + +#include +#include +#include + +static u_int16_t dccp_port_rover; + +static int +dccp_unique_tuple(struct nf_conntrack_tuple *tuple, + const struct nf_nat_range *range, + enum nf_nat_manip_type maniptype, + const struct nf_conn *ct) +{ + return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct, + &dccp_port_rover); +} + +static int +dccp_manip_pkt(struct sk_buff *skb, + unsigned int iphdroff, + const struct nf_conntrack_tuple *tuple, + enum nf_nat_manip_type maniptype) +{ + struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff); + struct dccp_hdr *hdr; + unsigned int hdroff = iphdroff + iph->ihl * 4; + __be32 oldip, newip; + __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 0; + + iph = (struct iphdr *)(skb->data + iphdroff); + hdr = (struct dccp_hdr *)(skb->data + hdroff); + + if (maniptype == IP_NAT_MANIP_SRC) { + oldip = iph->saddr; + newip = tuple->src.u3.ip; + newport = tuple->src.u.dccp.port; + portptr = &hdr->dccph_sport; + } else { + oldip = iph->daddr; + newip = tuple->dst.u3.ip; + newport = tuple->dst.u.dccp.port; + portptr = &hdr->dccph_dport; + } + + oldport = *portptr; + *portptr = newport; + + if (hdrsize < sizeof(*hdr)) + return 1; + + inet_proto_csum_replace4(&hdr->dccph_checksum, skb, oldip, newip, 1); + inet_proto_csum_replace2(&hdr->dccph_checksum, skb, oldport, newport, + 0); + return 1; +} + +static const struct nf_nat_protocol nf_nat_protocol_dccp = { + .protonum = IPPROTO_DCCP, + .me = THIS_MODULE, + .manip_pkt = dccp_manip_pkt, + .in_range = nf_nat_proto_in_range, + .unique_tuple = dccp_unique_tuple, +#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) + .range_to_nlattr = nf_nat_proto_range_to_nlattr, + .nlattr_to_range = nf_nat_proto_nlattr_to_range, +#endif +}; + +static int __init nf_nat_proto_dccp_init(void) +{ + return nf_nat_protocol_register(&nf_nat_protocol_dccp); +} + +static void __exit nf_nat_proto_dccp_fini(void) +{ + nf_nat_protocol_unregister(&nf_nat_protocol_dccp); +} + +module_init(nf_nat_proto_dccp_init); +module_exit(nf_nat_proto_dccp_fini); + +MODULE_AUTHOR("Patrick McHardy "); +MODULE_DESCRIPTION("DCCP NAT protocol helper"); +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c index dc316b9..b759ffa 100644 --- a/net/ipv4/netfilter/nf_nat_standalone.c +++ b/net/ipv4/netfilter/nf_nat_standalone.c @@ -51,7 +51,8 @@ static void nat_decode_session(struct sk_buff *skb, struct flowi *fl) fl->fl4_dst = t->dst.u3.ip; if (t->dst.protonum == IPPROTO_TCP || t->dst.protonum == IPPROTO_UDP || - t->dst.protonum == IPPROTO_UDPLITE) + t->dst.protonum == IPPROTO_UDPLITE || + t->dst.protonum == IPPROTO_DCCP) fl->fl_ip_dport = t->dst.u.tcp.port; } @@ -61,7 +62,8 @@ static void nat_decode_session(struct sk_buff *skb, struct flowi *fl) fl->fl4_src = t->src.u3.ip; if (t->dst.protonum == IPPROTO_TCP || t->dst.protonum == IPPROTO_UDP || - t->dst.protonum == IPPROTO_UDPLITE) + t->dst.protonum == IPPROTO_UDPLITE || + t->dst.protonum == IPPROTO_DCCP) fl->fl_ip_sport = t->src.u.tcp.port; } } -- 1.8.2.3