[NETFILTER]: nf_nat: add DCCP protocol support

Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index c5bd2840663b2dea8472d243eef47d409da4be72..fde3eacd196ddecc5a45d87e16d8379b39ab2416 100644 (file)
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -241,6 +241,11 @@ config NF_NAT_SNMP_BASIC
 #           <expr> '&&' <expr>                   (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 332f46fbc756d5f018e4746078300c59f5d538c5..74d8dbdc11202db684d64fe9db65e1c730cffeda 100644 (file)
--- 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 (file)
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 <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/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/dccp.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+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 <kaber@trash.net>");
+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 dc316b9f9b1d2fc4a6447dfa8424ed7c31308c65..b759ffa1098d6637a6539599d245ea89a58523f5 100644 (file)
--- 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;
        }
 }