[NETFILTER]: Add ctnetlink subsystem

Add ctnetlink subsystem for userspace-access to ip_conntrack table.
This allows reading and updating of existing entries, as well as
creating new ones (and new expect's) via nfnetlink.

Please note the 'strange' byte order: nfattr (tag+length) are in host
byte order, while the payload is always guaranteed to be in network
byte order.  This allows a simple userspace process to encapsulate netlink
messages into arch-independent udp packets by just processing/swapping the
headers and not knowing anything about the actual payload.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 2 deletions

diff --git a/net/ipv4/netfilter/ip_nat_proto_icmp.c b/net/ipv4/netfilter/ip_nat_proto_icmp.c
index 6596c9ee165..38fdfc2093c 100644
--- a/net/ipv4/netfilter/ip_nat_proto_icmp.c
+++ b/net/ipv4/netfilter/ip_nat_proto_icmp.c
@@ -107,10 +107,15 @@ icmp_print_range(char *buffer, const struct ip_nat_range *range)
 }
 
 struct ip_nat_protocol ip_nat_protocol_icmp
-= { "ICMP", IPPROTO_ICMP,
+= { "ICMP", IPPROTO_ICMP, THIS_MODULE,
     icmp_manip_pkt,
     icmp_in_range,
     icmp_unique_tuple,
     icmp_print,
-    icmp_print_range
+    icmp_print_range,
+#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
+    defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
+    ip_nat_port_range_to_nfattr,
+    ip_nat_port_nfattr_to_range,
+#endif
 };