[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>
diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
new file mode 100644
index 0000000..f43ec18
--- /dev/null
+++ b/net/ipv4/netfilter/ip_conntrack_netlink.c
@@ -0,0 +1,1588 @@
+/* Connection tracking via netlink socket. Allows for user space
+ * protocol helpers and general trouble making from userspace.
+ *
+ * (C) 2001 by Jay Schulist <jschlst@samba.org>
+ * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2003 by Patrick Mchardy <kaber@trash.net>
+ * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
+ *
+ * I've reworked this stuff to use attributes instead of conntrack 
+ * structures. 5.44 am. I need more tea. --pablo 05/07/11.
+ *
+ * Initial connection tracking via netlink development funded and 
+ * generally made possible by Network Robots, Inc. (www.networkrobots.com)
+ *
+ * Further development of this code funded by Astaro AG (http://www.astaro.com)
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/errno.h>
+#include <linux/netlink.h>
+#include <linux/spinlock.h>
+#include <linux/notifier.h>
+#include <linux/rtnetlink.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_conntrack_core.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_protocol.h>
+#include <linux/netfilter_ipv4/ip_nat_protocol.h>
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+MODULE_LICENSE("GPL");
+
+static char __initdata version[] = "0.90";
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+
+static inline int
+ctnetlink_dump_tuples_proto(struct sk_buff *skb, 
+			    const struct ip_conntrack_tuple *tuple)
+{
+	struct ip_conntrack_protocol *proto;
+
+	NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);
+
+	proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
+	if (proto && proto->tuple_to_nfattr)
+		return proto->tuple_to_nfattr(skb, tuple);
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_dump_tuples(struct sk_buff *skb, 
+		      const struct ip_conntrack_tuple *tuple)
+{
+	struct nfattr *nest_parms;
+	
+	nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);
+	NFA_PUT(skb, CTA_IP_V4_SRC, sizeof(u_int32_t), &tuple->src.ip);
+	NFA_PUT(skb, CTA_IP_V4_DST, sizeof(u_int32_t), &tuple->dst.ip);
+	NFA_NEST_END(skb, nest_parms);
+
+	nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
+	ctnetlink_dump_tuples_proto(skb, tuple);
+	NFA_NEST_END(skb, nest_parms);
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_dump_status(struct sk_buff *skb, const struct ip_conntrack *ct)
+{
+	u_int32_t status = htonl((u_int32_t) ct->status);
+	NFA_PUT(skb, CTA_STATUS, sizeof(status), &status);
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_dump_timeout(struct sk_buff *skb, const struct ip_conntrack *ct)
+{
+	long timeout_l = ct->timeout.expires - jiffies;
+	u_int32_t timeout;
+
+	if (timeout_l < 0)
+		timeout = 0;
+	else
+		timeout = htonl(timeout_l / HZ);
+	
+	NFA_PUT(skb, CTA_TIMEOUT, sizeof(timeout), &timeout);
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_dump_protoinfo(struct sk_buff *skb, const struct ip_conntrack *ct)
+{
+	struct ip_conntrack_protocol *proto = ip_conntrack_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
+
+	struct nfattr *nest_proto;
+	int ret;
+	
+	if (!proto || !proto->to_nfattr)
+		return 0;
+	
+	nest_proto = NFA_NEST(skb, CTA_PROTOINFO);
+
+	ret = proto->to_nfattr(skb, nest_proto, ct);
+
+	ip_conntrack_proto_put(proto);
+
+	NFA_NEST_END(skb, nest_proto);
+
+	return ret;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct ip_conntrack *ct)
+{
+	struct nfattr *nest_helper;
+
+	if (!ct->helper)
+		return 0;
+		
+	nest_helper = NFA_NEST(skb, CTA_HELP);
+	NFA_PUT(skb, CTA_HELP_NAME, CTA_HELP_MAXNAMESIZE, &ct->helper->name);
+
+	if (ct->helper->to_nfattr)
+		ct->helper->to_nfattr(skb, ct);
+
+	NFA_NEST_END(skb, nest_helper);
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+#ifdef CONFIG_IP_NF_CT_ACCT
+static inline int
+ctnetlink_dump_counters(struct sk_buff *skb, const struct ip_conntrack *ct,
+			enum ip_conntrack_dir dir)
+{
+	enum ctattr_type type = dir ? CTA_COUNTERS_REPLY: CTA_COUNTERS_ORIG;
+	struct nfattr *nest_count = NFA_NEST(skb, type);
+	u_int64_t tmp;
+
+	tmp = cpu_to_be64(ct->counters[dir].packets);
+	NFA_PUT(skb, CTA_COUNTERS_PACKETS, sizeof(u_int64_t), &tmp);
+
+	tmp = cpu_to_be64(ct->counters[dir].bytes);
+	NFA_PUT(skb, CTA_COUNTERS_BYTES, sizeof(u_int64_t), &tmp);
+
+	NFA_NEST_END(skb, nest_count);
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+#else
+#define ctnetlink_dump_counters(a, b, c) (0)
+#endif
+
+#ifdef CONFIG_IP_NF_CONNTRACK_MARK
+static inline int
+ctnetlink_dump_mark(struct sk_buff *skb, const struct ip_conntrack *ct)
+{
+	u_int32_t mark = htonl(ct->mark);
+
+	NFA_PUT(skb, CTA_MARK, sizeof(u_int32_t), &mark);
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+#else
+#define ctnetlink_dump_mark(a, b) (0)
+#endif
+
+static inline int
+ctnetlink_dump_id(struct sk_buff *skb, const struct ip_conntrack *ct)
+{
+	u_int32_t id = htonl(ct->id);
+	NFA_PUT(skb, CTA_ID, sizeof(u_int32_t), &id);
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_dump_use(struct sk_buff *skb, const struct ip_conntrack *ct)
+{
+	unsigned int use = htonl(atomic_read(&ct->ct_general.use));
+	
+	NFA_PUT(skb, CTA_USE, sizeof(u_int32_t), &use);
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+#define tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
+
+static int
+ctnetlink_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
+		    int event, int nowait, 
+		    const struct ip_conntrack *ct)
+{
+	struct nlmsghdr *nlh;
+	struct nfgenmsg *nfmsg;
+	struct nfattr *nest_parms;
+	unsigned char *b;
+
+	b = skb->tail;
+
+	event |= NFNL_SUBSYS_CTNETLINK << 8;
+	nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
+	nfmsg  = NLMSG_DATA(nlh);
+
+	nlh->nlmsg_flags    = (nowait && pid) ? NLM_F_MULTI : 0;
+	nfmsg->nfgen_family = AF_INET;
+	nfmsg->version      = NFNETLINK_V0;
+	nfmsg->res_id	    = 0;
+
+	nest_parms = NFA_NEST(skb, CTA_TUPLE_ORIG);
+	if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
+		goto nfattr_failure;
+	NFA_NEST_END(skb, nest_parms);
+	
+	nest_parms = NFA_NEST(skb, CTA_TUPLE_REPLY);
+	if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_REPLY)) < 0)
+		goto nfattr_failure;
+	NFA_NEST_END(skb, nest_parms);
+
+	if (ctnetlink_dump_status(skb, ct) < 0 ||
+	    ctnetlink_dump_timeout(skb, ct) < 0 ||
+	    ctnetlink_dump_counters(skb, ct, IP_CT_DIR_ORIGINAL) < 0 ||
+	    ctnetlink_dump_counters(skb, ct, IP_CT_DIR_REPLY) < 0 ||
+	    ctnetlink_dump_protoinfo(skb, ct) < 0 ||
+	    ctnetlink_dump_helpinfo(skb, ct) < 0 ||
+	    ctnetlink_dump_mark(skb, ct) < 0 ||
+	    ctnetlink_dump_id(skb, ct) < 0 ||
+	    ctnetlink_dump_use(skb, ct) < 0)
+		goto nfattr_failure;
+
+	nlh->nlmsg_len = skb->tail - b;
+	return skb->len;
+
+nlmsg_failure:
+nfattr_failure:
+	skb_trim(skb, b - skb->data);
+	return -1;
+}
+
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+static int ctnetlink_conntrack_event(struct notifier_block *this,
+                                     unsigned long events, void *ptr)
+{
+	struct nlmsghdr *nlh;
+	struct nfgenmsg *nfmsg;
+	struct nfattr *nest_parms;
+	struct ip_conntrack *ct = (struct ip_conntrack *)ptr;
+	struct sk_buff *skb;
+	unsigned int type;
+	unsigned char *b;
+	unsigned int flags = 0, groups;
+
+	/* ignore our fake conntrack entry */
+	if (ct == &ip_conntrack_untracked)
+		return NOTIFY_DONE;
+
+	if (events & IPCT_DESTROY) {
+		type = IPCTNL_MSG_CT_DELETE;
+		groups = NF_NETLINK_CONNTRACK_DESTROY;
+		goto alloc_skb;
+	}
+	if (events & (IPCT_NEW | IPCT_RELATED)) {
+		type = IPCTNL_MSG_CT_NEW;
+		flags = NLM_F_CREATE|NLM_F_EXCL;
+		/* dump everything */
+		events = ~0UL;
+		groups = NF_NETLINK_CONNTRACK_NEW;
+		goto alloc_skb;
+	}
+	if (events & (IPCT_STATUS |
+		      IPCT_PROTOINFO |
+		      IPCT_HELPER |
+		      IPCT_HELPINFO |
+		      IPCT_NATINFO)) {
+		type = IPCTNL_MSG_CT_NEW;
+		groups = NF_NETLINK_CONNTRACK_UPDATE;
+		goto alloc_skb;
+	} 
+	
+	return NOTIFY_DONE;
+
+alloc_skb:
+  /* FIXME: Check if there are any listeners before, don't hurt performance */
+	
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb)
+		return NOTIFY_DONE;
+
+	b = skb->tail;
+
+	type |= NFNL_SUBSYS_CTNETLINK << 8;
+	nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
+	nfmsg = NLMSG_DATA(nlh);
+
+	nlh->nlmsg_flags    = flags;
+	nfmsg->nfgen_family = AF_INET;
+	nfmsg->version	= NFNETLINK_V0;
+	nfmsg->res_id	= 0;
+
+	nest_parms = NFA_NEST(skb, CTA_TUPLE_ORIG);
+	if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
+		goto nfattr_failure;
+	NFA_NEST_END(skb, nest_parms);
+	
+	nest_parms = NFA_NEST(skb, CTA_TUPLE_REPLY);
+	if (ctnetlink_dump_tuples(skb, tuple(ct, IP_CT_DIR_REPLY)) < 0)
+		goto nfattr_failure;
+	NFA_NEST_END(skb, nest_parms);
+	
+	/* NAT stuff is now a status flag */
+	if ((events & IPCT_STATUS || events & IPCT_NATINFO)
+	    && ctnetlink_dump_status(skb, ct) < 0)
+		goto nfattr_failure;
+	if (events & IPCT_REFRESH
+	    && ctnetlink_dump_timeout(skb, ct) < 0)
+		goto nfattr_failure;
+	if (events & IPCT_PROTOINFO
+	    && ctnetlink_dump_protoinfo(skb, ct) < 0)
+		goto nfattr_failure;
+	if (events & IPCT_HELPINFO
+	    && ctnetlink_dump_helpinfo(skb, ct) < 0)
+		goto nfattr_failure;
+
+	if (ctnetlink_dump_counters(skb, ct, IP_CT_DIR_ORIGINAL) < 0 ||
+	    ctnetlink_dump_counters(skb, ct, IP_CT_DIR_REPLY) < 0)
+		goto nfattr_failure;
+
+	nlh->nlmsg_len = skb->tail - b;
+	nfnetlink_send(skb, 0, groups, 0);
+	return NOTIFY_DONE;
+
+nlmsg_failure:
+nfattr_failure:
+	kfree_skb(skb);
+	return NOTIFY_DONE;
+}
+#endif /* CONFIG_IP_NF_CONNTRACK_EVENTS */
+
+static int ctnetlink_done(struct netlink_callback *cb)
+{
+	DEBUGP("entered %s\n", __FUNCTION__);
+	return 0;
+}
+
+static int
+ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ip_conntrack *ct = NULL;
+	struct ip_conntrack_tuple_hash *h;
+	struct list_head *i;
+	u_int32_t *id = (u_int32_t *) &cb->args[1];
+
+	DEBUGP("entered %s, last bucket=%lu id=%u\n", __FUNCTION__, 
+			cb->args[0], *id);
+
+	read_lock_bh(&ip_conntrack_lock);
+	for (; cb->args[0] < ip_conntrack_htable_size; cb->args[0]++, *id = 0) {
+		list_for_each(i, &ip_conntrack_hash[cb->args[0]]) {
+			h = (struct ip_conntrack_tuple_hash *) i;
+			if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
+				continue;
+			ct = tuplehash_to_ctrack(h);
+			if (ct->id <= *id)
+				continue;
+			if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid,
+		                        	cb->nlh->nlmsg_seq,
+						IPCTNL_MSG_CT_NEW,
+						1, ct) < 0)
+				goto out;
+			*id = ct->id;
+		}
+	}
+out:	
+	read_unlock_bh(&ip_conntrack_lock);
+
+	DEBUGP("leaving, last bucket=%lu id=%u\n", cb->args[0], *id);
+
+	return skb->len;
+}
+
+#ifdef CONFIG_IP_NF_CT_ACCT
+static int
+ctnetlink_dump_table_w(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ip_conntrack *ct = NULL;
+	struct ip_conntrack_tuple_hash *h;
+	struct list_head *i;
+	u_int32_t *id = (u_int32_t *) &cb->args[1];
+
+	DEBUGP("entered %s, last bucket=%u id=%u\n", __FUNCTION__, 
+			cb->args[0], *id);
+
+	write_lock_bh(&ip_conntrack_lock);
+	for (; cb->args[0] < ip_conntrack_htable_size; cb->args[0]++, *id = 0) {
+		list_for_each(i, &ip_conntrack_hash[cb->args[0]]) {
+			h = (struct ip_conntrack_tuple_hash *) i;
+			if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
+				continue;
+			ct = tuplehash_to_ctrack(h);
+			if (ct->id <= *id)
+				continue;
+			if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid,
+		                        	cb->nlh->nlmsg_seq,
+						IPCTNL_MSG_CT_NEW,
+						1, ct) < 0)
+				goto out;
+			*id = ct->id;
+
+			memset(&ct->counters, 0, sizeof(ct->counters));
+		}
+	}
+out:	
+	write_unlock_bh(&ip_conntrack_lock);
+
+	DEBUGP("leaving, last bucket=%lu id=%u\n", cb->args[0], *id);
+
+	return skb->len;
+}
+#endif
+
+static const int cta_min_ip[CTA_IP_MAX] = {
+	[CTA_IP_V4_SRC-1]	= sizeof(u_int32_t),
+	[CTA_IP_V4_DST-1]	= sizeof(u_int32_t),
+};
+
+static inline int
+ctnetlink_parse_tuple_ip(struct nfattr *attr, struct ip_conntrack_tuple *tuple)
+{
+	struct nfattr *tb[CTA_IP_MAX];
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	memset(tb, 0, CTA_IP_MAX * sizeof(tb));
+	
+	if (nfattr_parse_nested(tb, CTA_IP_MAX, attr) < 0)
+		goto nfattr_failure;
+
+	if (nfattr_bad_size(tb, CTA_IP_MAX, cta_min_ip))
+		return -EINVAL;
+
+	if (!tb[CTA_IP_V4_SRC-1])
+		return -EINVAL;
+	tuple->src.ip = *(u_int32_t *)NFA_DATA(tb[CTA_IP_V4_SRC-1]);
+
+	if (!tb[CTA_IP_V4_DST-1])
+		return -EINVAL;
+	tuple->dst.ip = *(u_int32_t *)NFA_DATA(tb[CTA_IP_V4_DST-1]);
+
+	DEBUGP("leaving\n");
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static const int cta_min_proto[CTA_PROTO_MAX] = {
+	[CTA_PROTO_NUM-1]	= sizeof(u_int16_t),
+	[CTA_PROTO_SRC_PORT-1]	= sizeof(u_int16_t),
+	[CTA_PROTO_DST_PORT-1]	= sizeof(u_int16_t),
+	[CTA_PROTO_ICMP_TYPE-1]	= sizeof(u_int8_t),
+	[CTA_PROTO_ICMP_CODE-1]	= sizeof(u_int8_t),
+	[CTA_PROTO_ICMP_ID-1]	= sizeof(u_int16_t),
+};
+
+static inline int
+ctnetlink_parse_tuple_proto(struct nfattr *attr, 
+			    struct ip_conntrack_tuple *tuple)
+{
+	struct nfattr *tb[CTA_PROTO_MAX];
+	struct ip_conntrack_protocol *proto;
+	int ret = 0;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	memset(tb, 0, CTA_PROTO_MAX * sizeof(tb));
+	
+	if (nfattr_parse_nested(tb, CTA_PROTO_MAX, attr) < 0)
+		goto nfattr_failure;
+
+	if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
+		return -EINVAL;
+
+	if (!tb[CTA_PROTO_NUM-1])
+		return -EINVAL;
+	tuple->dst.protonum = *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_NUM-1]);
+
+	proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
+
+	if (likely(proto && proto->nfattr_to_tuple)) {
+		ret = proto->nfattr_to_tuple(tb, tuple);
+		ip_conntrack_proto_put(proto);
+	}
+	
+	return ret;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_parse_tuple(struct nfattr *cda[], struct ip_conntrack_tuple *tuple,
+		      enum ctattr_tuple type)
+{
+	struct nfattr *tb[CTA_TUPLE_MAX];
+	int err;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	memset(tb, 0, CTA_TUPLE_MAX * sizeof(tb));
+	memset(tuple, 0, sizeof(*tuple));
+
+	if (nfattr_parse_nested(tb, CTA_TUPLE_MAX, cda[type-1]) < 0)
+		goto nfattr_failure;
+
+	if (!tb[CTA_TUPLE_IP-1])
+		return -EINVAL;
+
+	err = ctnetlink_parse_tuple_ip(tb[CTA_TUPLE_IP-1], tuple);
+	if (err < 0)
+		return err;
+
+	if (!tb[CTA_TUPLE_PROTO-1])
+		return -EINVAL;
+
+	err = ctnetlink_parse_tuple_proto(tb[CTA_TUPLE_PROTO-1], tuple);
+	if (err < 0)
+		return err;
+
+	/* orig and expect tuples get DIR_ORIGINAL */
+	if (type == CTA_TUPLE_REPLY)
+		tuple->dst.dir = IP_CT_DIR_REPLY;
+	else
+		tuple->dst.dir = IP_CT_DIR_ORIGINAL;
+
+	DUMP_TUPLE(tuple);
+
+	DEBUGP("leaving\n");
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+static const int cta_min_protonat[CTA_PROTONAT_MAX] = {
+	[CTA_PROTONAT_PORT_MIN-1]	= sizeof(u_int16_t),
+	[CTA_PROTONAT_PORT_MAX-1]	= sizeof(u_int16_t),
+};
+
+static int ctnetlink_parse_nat_proto(struct nfattr *attr,
+				     const struct ip_conntrack *ct,
+				     struct ip_nat_range *range)
+{
+	struct nfattr *tb[CTA_PROTONAT_MAX];
+	struct ip_nat_protocol *npt;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	memset(tb, 0, CTA_PROTONAT_MAX * sizeof(tb));
+
+	if (nfattr_parse_nested(tb, CTA_PROTONAT_MAX, attr) < 0)
+		goto nfattr_failure;
+
+	if (nfattr_bad_size(tb, CTA_PROTONAT_MAX, cta_min_protonat))
+		goto nfattr_failure;
+
+	npt = ip_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
+	if (!npt)
+		return 0;
+
+	if (!npt->nfattr_to_range) {
+		ip_nat_proto_put(npt);
+		return 0;
+	}
+
+	/* nfattr_to_range returns 1 if it parsed, 0 if not, neg. on error */
+	if (npt->nfattr_to_range(tb, range) > 0)
+		range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
+
+	ip_nat_proto_put(npt);
+
+	DEBUGP("leaving\n");
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static inline int
+ctnetlink_parse_nat(struct nfattr *cda[],
+		    const struct ip_conntrack *ct, struct ip_nat_range *range)
+{
+	struct nfattr *tb[CTA_NAT_MAX];
+	int err;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	memset(tb, 0, CTA_NAT_MAX * sizeof(tb));
+	memset(range, 0, sizeof(*range));
+	
+	if (nfattr_parse_nested(tb, CTA_NAT_MAX, cda[CTA_NAT-1]) < 0)
+		goto nfattr_failure;
+
+	if (tb[CTA_NAT_MINIP-1])
+		range->min_ip = *(u_int32_t *)NFA_DATA(tb[CTA_NAT_MINIP-1]);
+
+	if (!tb[CTA_NAT_MAXIP-1])
+		range->max_ip = range->min_ip;
+	else
+		range->max_ip = *(u_int32_t *)NFA_DATA(tb[CTA_NAT_MAXIP-1]);
+
+	if (range->min_ip)
+		range->flags |= IP_NAT_RANGE_MAP_IPS;
+
+	if (!tb[CTA_NAT_PROTO-1])
+		return 0;
+
+	err = ctnetlink_parse_nat_proto(tb[CTA_NAT_PROTO-1], ct, range);
+	if (err < 0)
+		return err;
+
+	DEBUGP("leaving\n");
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+#endif
+
+static inline int
+ctnetlink_parse_help(struct nfattr *attr, char **helper_name)
+{
+	struct nfattr *tb[CTA_HELP_MAX];
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+	memset(tb, 0, CTA_HELP_MAX * sizeof(tb));
+
+	if (nfattr_parse_nested(tb, CTA_HELP_MAX, attr) < 0)
+		goto nfattr_failure;
+
+	if (!tb[CTA_HELP_NAME-1])
+		return -EINVAL;
+
+	*helper_name = NFA_DATA(tb[CTA_HELP_NAME-1]);
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}
+
+static int
+ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb, 
+			struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
+{
+	struct ip_conntrack_tuple_hash *h;
+	struct ip_conntrack_tuple tuple;
+	struct ip_conntrack *ct;
+	int err = 0;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	if (cda[CTA_TUPLE_ORIG-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG);
+	else if (cda[CTA_TUPLE_REPLY-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY);
+	else {
+		/* Flush the whole table */
+		ip_conntrack_flush();
+		return 0;
+	}
+
+	if (err < 0)
+		return err;
+
+	h = ip_conntrack_find_get(&tuple, NULL);
+	if (!h) {
+		DEBUGP("tuple not found in conntrack hash\n");
+		return -ENOENT;
+	}
+
+	ct = tuplehash_to_ctrack(h);
+	
+	if (cda[CTA_ID-1]) {
+		u_int32_t id = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_ID-1]));
+		if (ct->id != id) {
+			ip_conntrack_put(ct);
+			return -ENOENT;
+		}
+	}	
+	if (del_timer(&ct->timeout)) {
+		ip_conntrack_put(ct);
+		ct->timeout.function((unsigned long)ct);
+		return 0;
+	}
+	ip_conntrack_put(ct);
+	DEBUGP("leaving\n");
+
+	return 0;
+}
+
+static int
+ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb, 
+			struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
+{
+	struct ip_conntrack_tuple_hash *h;
+	struct ip_conntrack_tuple tuple;
+	struct ip_conntrack *ct;
+	struct sk_buff *skb2 = NULL;
+	int err = 0;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	if (nlh->nlmsg_flags & NLM_F_DUMP) {
+		struct nfgenmsg *msg = NLMSG_DATA(nlh);
+		u32 rlen;
+
+		if (msg->nfgen_family != AF_INET)
+			return -EAFNOSUPPORT;
+
+		if (NFNL_MSG_TYPE(nlh->nlmsg_type) ==
+					IPCTNL_MSG_CT_GET_CTRZERO) {
+#ifdef CONFIG_IP_NF_CT_ACCT
+			if ((*errp = netlink_dump_start(ctnl, skb, nlh,
+						ctnetlink_dump_table_w,
+						ctnetlink_done)) != 0)
+				return -EINVAL;
+#else
+			return -ENOTSUPP;
+#endif
+		} else {
+			if ((*errp = netlink_dump_start(ctnl, skb, nlh,
+		      		                        ctnetlink_dump_table,
+		                                	ctnetlink_done)) != 0)
+			return -EINVAL;
+		}
+
+		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
+		if (rlen > skb->len)
+			rlen = skb->len;
+		skb_pull(skb, rlen);
+		return 0;
+	}
+
+	if (cda[CTA_TUPLE_ORIG-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG);
+	else if (cda[CTA_TUPLE_REPLY-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY);
+	else
+		return -EINVAL;
+
+	if (err < 0)
+		return err;
+
+	h = ip_conntrack_find_get(&tuple, NULL);
+	if (!h) {
+		DEBUGP("tuple not found in conntrack hash");
+		return -ENOENT;
+	}
+	DEBUGP("tuple found\n");
+	ct = tuplehash_to_ctrack(h);
+
+	err = -ENOMEM;
+	skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb2) {
+		ip_conntrack_put(ct);
+		return -ENOMEM;
+	}
+	NETLINK_CB(skb2).dst_pid = NETLINK_CB(skb).pid;
+
+	err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).pid, nlh->nlmsg_seq, 
+				  IPCTNL_MSG_CT_NEW, 1, ct);
+	ip_conntrack_put(ct);
+	if (err <= 0)
+		goto out;
+
+	err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);
+	if (err < 0)
+		goto out;
+
+	DEBUGP("leaving\n");
+	return 0;
+
+out:
+	if (skb2)
+		kfree_skb(skb2);
+	return -1;
+}
+
+static inline int
+ctnetlink_change_status(struct ip_conntrack *ct, struct nfattr *cda[])
+{
+	unsigned long d, status = *(u_int32_t *)NFA_DATA(cda[CTA_STATUS-1]);
+	d = ct->status ^ status;
+
+	if (d & (IPS_EXPECTED|IPS_CONFIRMED|IPS_DYING))
+		/* unchangeable */
+		return -EINVAL;
+	
+	if (d & IPS_SEEN_REPLY && !(status & IPS_SEEN_REPLY))
+		/* SEEN_REPLY bit can only be set */
+		return -EINVAL;
+
+	
+	if (d & IPS_ASSURED && !(status & IPS_ASSURED))
+		/* ASSURED bit can only be set */
+		return -EINVAL;
+
+	if (cda[CTA_NAT-1]) {
+#ifndef CONFIG_IP_NF_NAT_NEEDED
+		return -EINVAL;
+#else
+		unsigned int hooknum;
+		struct ip_nat_range range;
+
+		if (ctnetlink_parse_nat(cda, ct, &range) < 0)
+			return -EINVAL;
+
+		DEBUGP("NAT: %u.%u.%u.%u-%u.%u.%u.%u:%u-%u\n", 
+		       NIPQUAD(range.min_ip), NIPQUAD(range.max_ip),
+		       htons(range.min.all), htons(range.max.all));
+		
+		/* This is tricky but it works. ip_nat_setup_info needs the
+		 * hook number as parameter, so let's do the correct 
+		 * conversion and run away */
+		if (status & IPS_SRC_NAT_DONE)
+			hooknum = NF_IP_POST_ROUTING; /* IP_NAT_MANIP_SRC */
+		else if (status & IPS_DST_NAT_DONE)
+			hooknum = NF_IP_PRE_ROUTING;  /* IP_NAT_MANIP_DST */
+		else 
+			return -EINVAL; /* Missing NAT flags */
+
+		DEBUGP("NAT status: %lu\n", 
+		       status & (IPS_NAT_MASK | IPS_NAT_DONE_MASK));
+		
+		if (ip_nat_initialized(ct, hooknum))
+			return -EEXIST;
+		ip_nat_setup_info(ct, &range, hooknum);
+
+                DEBUGP("NAT status after setup_info: %lu\n",
+                       ct->status & (IPS_NAT_MASK | IPS_NAT_DONE_MASK));
+#endif
+	}
+
+	/* Be careful here, modifying NAT bits can screw up things,
+	 * so don't let users modify them directly if they don't pass
+	 * ip_nat_range. */
+	ct->status |= status & ~(IPS_NAT_DONE_MASK | IPS_NAT_MASK);
+	return 0;
+}
+
+
+static inline int
+ctnetlink_change_helper(struct ip_conntrack *ct, struct nfattr *cda[])
+{
+	struct ip_conntrack_helper *helper;
+	char *helpname;
+	int err;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	/* don't change helper of sibling connections */
+	if (ct->master)
+		return -EINVAL;
+
+	err = ctnetlink_parse_help(cda[CTA_HELP-1], &helpname);
+	if (err < 0)
+		return err;
+
+	helper = __ip_conntrack_helper_find_byname(helpname);
+	if (!helper) {
+		if (!strcmp(helpname, ""))
+			helper = NULL;
+		else
+			return -EINVAL;
+	}
+
+	if (ct->helper) {
+		if (!helper) {
+			/* we had a helper before ... */
+			ip_ct_remove_expectations(ct);
+			ct->helper = NULL;
+		} else {
+			/* need to zero data of old helper */
+			memset(&ct->help, 0, sizeof(ct->help));
+		}
+	}
+	
+	ct->helper = helper;
+
+	return 0;
+}
+
+static inline int
+ctnetlink_change_timeout(struct ip_conntrack *ct, struct nfattr *cda[])
+{
+	u_int32_t timeout = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_TIMEOUT-1]));
+	
+	if (!del_timer(&ct->timeout))
+		return -ETIME;
+
+	ct->timeout.expires = jiffies + timeout * HZ;
+	add_timer(&ct->timeout);
+
+	return 0;
+}
+
+static int
+ctnetlink_change_conntrack(struct ip_conntrack *ct, struct nfattr *cda[])
+{
+	int err;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	if (cda[CTA_HELP-1]) {
+		err = ctnetlink_change_helper(ct, cda);
+		if (err < 0)
+			return err;
+	}
+
+	if (cda[CTA_TIMEOUT-1]) {
+		err = ctnetlink_change_timeout(ct, cda);
+		if (err < 0)
+			return err;
+	}
+
+	if (cda[CTA_STATUS-1]) {
+		err = ctnetlink_change_status(ct, cda);
+		if (err < 0)
+			return err;
+	}
+
+	DEBUGP("all done\n");
+	return 0;
+}
+
+static int
+ctnetlink_create_conntrack(struct nfattr *cda[], 
+			   struct ip_conntrack_tuple *otuple,
+			   struct ip_conntrack_tuple *rtuple)
+{
+	struct ip_conntrack *ct;
+	int err = -EINVAL;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	ct = ip_conntrack_alloc(otuple, rtuple);
+	if (ct == NULL || IS_ERR(ct))
+		return -ENOMEM;	
+
+	if (!cda[CTA_TIMEOUT-1])
+		goto err;
+	ct->timeout.expires = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_TIMEOUT-1]));
+
+	ct->timeout.expires = jiffies + ct->timeout.expires * HZ;
+	ct->status |= IPS_CONFIRMED;
+
+	err = ctnetlink_change_status(ct, cda);
+	if (err < 0)
+		goto err;
+
+	ct->helper = ip_conntrack_helper_find_get(rtuple);
+
+	add_timer(&ct->timeout);
+	ip_conntrack_hash_insert(ct);
+
+	if (ct->helper)
+		ip_conntrack_helper_put(ct->helper);
+
+	DEBUGP("conntrack with id %u inserted\n", ct->id);
+	return 0;
+
+err:	
+	ip_conntrack_free(ct);
+	return err;
+}
+
+static int 
+ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb, 
+			struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
+{
+	struct ip_conntrack_tuple otuple, rtuple;
+	struct ip_conntrack_tuple_hash *h = NULL;
+	int err = 0;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	if (cda[CTA_TUPLE_ORIG-1]) {
+		err = ctnetlink_parse_tuple(cda, &otuple, CTA_TUPLE_ORIG);
+		if (err < 0)
+			return err;
+	}
+
+	if (cda[CTA_TUPLE_REPLY-1]) {
+		err = ctnetlink_parse_tuple(cda, &rtuple, CTA_TUPLE_REPLY);
+		if (err < 0)
+			return err;
+	}
+
+	write_lock_bh(&ip_conntrack_lock);
+	if (cda[CTA_TUPLE_ORIG-1])
+		h = __ip_conntrack_find(&otuple, NULL);
+	else if (cda[CTA_TUPLE_REPLY-1])
+		h = __ip_conntrack_find(&rtuple, NULL);
+
+	if (h == NULL) {
+		write_unlock_bh(&ip_conntrack_lock);
+		DEBUGP("no such conntrack, create new\n");
+		err = -ENOENT;
+		if (nlh->nlmsg_flags & NLM_F_CREATE)
+			err = ctnetlink_create_conntrack(cda, &otuple, &rtuple);
+		goto out_unlock;
+	} else {
+		/* we only allow nat config for new conntracks */
+		if (cda[CTA_NAT-1]) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
+	}
+
+	/* We manipulate the conntrack inside the global conntrack table lock,
+	 * so there's no need to increase the refcount */
+	DEBUGP("conntrack found\n");
+	err = -EEXIST;
+	if (!(nlh->nlmsg_flags & NLM_F_EXCL))
+		err = ctnetlink_change_conntrack(tuplehash_to_ctrack(h), cda);
+
+out_unlock:
+	write_unlock_bh(&ip_conntrack_lock);
+	return err;
+}
+
+/*********************************************************************** 
+ * EXPECT 
+ ***********************************************************************/ 
+
+static inline int
+ctnetlink_exp_dump_tuple(struct sk_buff *skb,
+			 const struct ip_conntrack_tuple *tuple,
+			 enum ctattr_expect type)
+{
+	struct nfattr *nest_parms = NFA_NEST(skb, type);
+	
+	if (ctnetlink_dump_tuples(skb, tuple) < 0)
+		goto nfattr_failure;
+
+	NFA_NEST_END(skb, nest_parms);
+
+	return 0;
+
+nfattr_failure:
+	return -1;
+}			
+
+static inline int
+ctnetlink_exp_dump_expect(struct sk_buff *skb,
+                          const struct ip_conntrack_expect *exp)
+{
+	u_int32_t timeout = htonl((exp->timeout.expires - jiffies) / HZ);
+	u_int32_t id = htonl(exp->id);
+	struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT);
+
+	if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)
+		goto nfattr_failure;
+	if (ctnetlink_exp_dump_tuple(skb, &exp->mask, CTA_EXPECT_MASK) < 0)
+		goto nfattr_failure;
+	
+	NFA_PUT(skb, CTA_EXPECT_TIMEOUT, sizeof(timeout), &timeout);
+	NFA_PUT(skb, CTA_EXPECT_ID, sizeof(u_int32_t), &id);
+	NFA_NEST_END(skb, nest_parms);
+
+	return 0;
+	
+nfattr_failure:
+	return -1;
+}
+
+static int
+ctnetlink_exp_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
+		    int event, 
+		    int nowait, 
+		    const struct ip_conntrack_expect *exp)
+{
+	struct nlmsghdr *nlh;
+	struct nfgenmsg *nfmsg;
+	unsigned char *b;
+
+	b = skb->tail;
+
+	event |= NFNL_SUBSYS_CTNETLINK_EXP << 8;
+	nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
+	nfmsg  = NLMSG_DATA(nlh);
+
+	nlh->nlmsg_flags    = (nowait && pid) ? NLM_F_MULTI : 0;
+	nfmsg->nfgen_family = AF_INET;
+	nfmsg->version	    = NFNETLINK_V0;
+	nfmsg->res_id	    = 0;
+
+	if (ctnetlink_exp_dump_expect(skb, exp) < 0)
+		goto nfattr_failure;
+
+	nlh->nlmsg_len = skb->tail - b;
+	return skb->len;
+
+nlmsg_failure:
+nfattr_failure:
+	skb_trim(skb, b - skb->data);
+	return -1;
+}
+
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+static int ctnetlink_expect_event(struct notifier_block *this,
+				  unsigned long events, void *ptr)
+{
+	struct nlmsghdr *nlh;
+	struct nfgenmsg *nfmsg;
+	struct ip_conntrack_expect *exp = (struct ip_conntrack_expect *)ptr;
+	struct sk_buff *skb;
+	unsigned int type;
+	unsigned char *b;
+	int flags = 0;
+	u16 proto;
+
+	if (events & IPEXP_NEW) {
+		type = IPCTNL_MSG_EXP_NEW;
+		flags = NLM_F_CREATE|NLM_F_EXCL;
+	} else
+		return NOTIFY_DONE;
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb)
+		return NOTIFY_DONE;
+
+	b = skb->tail;
+
+	type |= NFNL_SUBSYS_CTNETLINK << 8;
+	nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
+	nfmsg = NLMSG_DATA(nlh);
+
+	nlh->nlmsg_flags    = flags;
+	nfmsg->nfgen_family = AF_INET;
+	nfmsg->version	    = NFNETLINK_V0;
+	nfmsg->res_id	    = 0;
+
+	if (ctnetlink_exp_dump_expect(skb, exp) < 0)
+		goto nfattr_failure;
+
+	nlh->nlmsg_len = skb->tail - b;
+	proto = exp->tuple.dst.protonum;
+	nfnetlink_send(skb, 0, NF_NETLINK_CONNTRACK_EXP_NEW, 0);
+	return NOTIFY_DONE;
+
+nlmsg_failure:
+nfattr_failure:
+	kfree_skb(skb);
+	return NOTIFY_DONE;
+}
+#endif
+
+static int
+ctnetlink_exp_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ip_conntrack_expect *exp = NULL;
+	struct list_head *i;
+	u_int32_t *id = (u_int32_t *) &cb->args[0];
+
+	DEBUGP("entered %s, last id=%llu\n", __FUNCTION__, *id);
+
+	read_lock_bh(&ip_conntrack_lock);
+	list_for_each(i, &ip_conntrack_expect_list) {
+		exp = (struct ip_conntrack_expect *) i;
+		if (exp->id <= *id)
+			continue;
+		if (ctnetlink_exp_fill_info(skb, NETLINK_CB(cb->skb).pid,
+					    cb->nlh->nlmsg_seq,
+					    IPCTNL_MSG_EXP_NEW,
+					    1, exp) < 0)
+			goto out;
+		*id = exp->id;
+	}
+out:	
+	read_unlock_bh(&ip_conntrack_lock);
+
+	DEBUGP("leaving, last id=%llu\n", *id);
+
+	return skb->len;
+}
+
+static int
+ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb, 
+		     struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
+{
+	struct ip_conntrack_tuple tuple;
+	struct ip_conntrack_expect *exp;
+	struct sk_buff *skb2;
+	int err = 0;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	if (nlh->nlmsg_flags & NLM_F_DUMP) {
+		struct nfgenmsg *msg = NLMSG_DATA(nlh);
+		u32 rlen;
+
+		if (msg->nfgen_family != AF_INET)
+			return -EAFNOSUPPORT;
+
+		if ((*errp = netlink_dump_start(ctnl, skb, nlh,
+		    				ctnetlink_exp_dump_table,
+						ctnetlink_done)) != 0)
+			return -EINVAL;
+		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
+		if (rlen > skb->len)
+			rlen = skb->len;
+		skb_pull(skb, rlen);
+		return 0;
+	}
+
+	if (cda[CTA_TUPLE_ORIG-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG);
+	else if (cda[CTA_TUPLE_REPLY-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY);
+	else
+		return -EINVAL;
+
+	if (err < 0)
+		return err;
+
+	exp = ip_conntrack_expect_find_get(&tuple);
+	if (!exp)
+		return -ENOENT;
+
+	err = -ENOMEM;
+	skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb2)
+		goto out;
+	NETLINK_CB(skb2).dst_pid = NETLINK_CB(skb).pid;
+	
+	err = ctnetlink_exp_fill_info(skb2, NETLINK_CB(skb).pid, 
+				      nlh->nlmsg_seq, IPCTNL_MSG_EXP_NEW,
+				      1, exp);
+	if (err <= 0)
+		goto out;
+
+	ip_conntrack_expect_put(exp);
+
+	err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);
+	if (err < 0)
+		goto free;
+
+	return err;
+
+out:
+	ip_conntrack_expect_put(exp);
+free:
+	if (skb2)
+		kfree_skb(skb2);
+	return err;
+}
+
+static int
+ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb, 
+		     struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
+{
+	struct ip_conntrack_expect *exp, *tmp;
+	struct ip_conntrack_tuple tuple;
+	struct ip_conntrack_helper *h;
+	int err;
+
+	/* delete by tuple needs either orig or reply tuple */
+	if (cda[CTA_TUPLE_ORIG-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG);
+	else if (cda[CTA_TUPLE_REPLY-1])
+		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY);
+	else if (cda[CTA_HELP_NAME-1]) {
+		char *name = NFA_DATA(cda[CTA_HELP_NAME-1]);
+
+		/* delete all expectations for this helper */
+		write_lock_bh(&ip_conntrack_lock);
+		h = __ip_conntrack_helper_find_byname(name);
+		if (!h) {
+			write_unlock_bh(&ip_conntrack_lock);
+			return -EINVAL;
+		}
+		list_for_each_entry_safe(exp, tmp, &ip_conntrack_expect_list,
+					 list) {
+			if (exp->master->helper == h 
+			    && del_timer(&exp->timeout))
+				__ip_ct_expect_unlink_destroy(exp);
+		}
+		write_unlock(&ip_conntrack_lock);
+		return 0;
+	} else {
+		/* This basically means we have to flush everything*/
+		write_lock_bh(&ip_conntrack_lock);
+		list_for_each_entry_safe(exp, tmp, &ip_conntrack_expect_list,
+					 list) {
+			if (del_timer(&exp->timeout))
+				__ip_ct_expect_unlink_destroy(exp);
+		}
+		write_unlock_bh(&ip_conntrack_lock);
+		return 0;
+	}
+
+	if (err < 0)
+		return err;
+
+	/* bump usage count to 2 */
+	exp = ip_conntrack_expect_find_get(&tuple);
+	if (!exp)
+		return -ENOENT;
+
+	if (cda[CTA_EXPECT_ID-1]) {
+		u_int32_t id = *(u_int32_t *)NFA_DATA(cda[CTA_EXPECT_ID-1]);
+		if (exp->id != ntohl(id)) {
+			ip_conntrack_expect_put(exp);
+			return -ENOENT;
+		}
+	}
+
+	/* after list removal, usage count == 1 */
+	ip_conntrack_unexpect_related(exp);
+	/* have to put what we 'get' above. after this line usage count == 0 */
+	ip_conntrack_expect_put(exp);
+
+	return 0;
+}
+static int
+ctnetlink_change_expect(struct ip_conntrack_expect *x, struct nfattr *cda[])
+{
+	return -EOPNOTSUPP;
+}
+
+static int
+ctnetlink_create_expect(struct nfattr *cda[])
+{
+	struct ip_conntrack_tuple tuple, mask, master_tuple;
+	struct ip_conntrack_tuple_hash *h = NULL;
+	struct ip_conntrack_expect *exp;
+	struct ip_conntrack *ct;
+	int err = 0;
+
+	DEBUGP("entered %s\n", __FUNCTION__);
+
+	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE);
+	if (err < 0)
+		return err;
+	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASK);
+	if (err < 0)
+		return err;
+
+	if (cda[CTA_TUPLE_ORIG-1])
+		err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_TUPLE_ORIG);
+	else if (cda[CTA_TUPLE_REPLY-1])
+		err = ctnetlink_parse_tuple(cda, &master_tuple, 
+					    CTA_TUPLE_REPLY);
+	else
+		return -EINVAL;
+
+	if (err < 0)
+		return err;
+
+	/* Look for master conntrack of this expectation */
+	h = ip_conntrack_find_get(&master_tuple, NULL);
+	if (!h)
+		return -ENOENT;
+	ct = tuplehash_to_ctrack(h);
+
+	if (!ct->helper) {
+		/* such conntrack hasn't got any helper, abort */
+		err = -EINVAL;
+		goto out;
+	}
+
+	exp = ip_conntrack_expect_alloc(ct);
+	if (!exp) {
+		err = -ENOMEM;
+		goto out;
+	}
+	
+	exp->expectfn = NULL;
+	exp->master = ct;
+	memcpy(&exp->tuple, &tuple, sizeof(struct ip_conntrack_tuple));
+	memcpy(&exp->mask, &mask, sizeof(struct ip_conntrack_tuple));
+
+	err = ip_conntrack_expect_related(exp);
+	ip_conntrack_expect_put(exp);
+
+out:	
+	ip_conntrack_put(tuplehash_to_ctrack(h));
+	return err;
+}
+
+static int
+ctnetlink_new_expect(struct sock *ctnl, struct sk_buff *skb,
+		     struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)
+{
+	struct ip_conntrack_tuple tuple;
+	struct ip_conntrack_expect *exp;
+	int err = 0;
+
+	DEBUGP("entered %s\n", __FUNCTION__);	
+
+	if (!cda[CTA_EXPECT_TUPLE-1] || !cda[CTA_EXPECT_MASK-1])
+		return -EINVAL;
+
+	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE);
+	if (err < 0)
+		return err;
+
+	write_lock_bh(&ip_conntrack_lock);
+	exp = __ip_conntrack_expect_find(&tuple);
+
+	if (!exp) {
+		write_unlock_bh(&ip_conntrack_lock);
+		err = -ENOENT;
+		if (nlh->nlmsg_flags & NLM_F_CREATE)
+			err = ctnetlink_create_expect(cda);
+		return err;
+	}
+
+	err = -EEXIST;
+	if (!(nlh->nlmsg_flags & NLM_F_EXCL))
+		err = ctnetlink_change_expect(exp, cda);
+	write_unlock_bh(&ip_conntrack_lock);
+
+	DEBUGP("leaving\n");
+	
+	return err;
+}
+
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+static struct notifier_block ctnl_notifier = {
+	.notifier_call	= ctnetlink_conntrack_event,
+};
+
+static struct notifier_block ctnl_notifier_exp = {
+	.notifier_call	= ctnetlink_expect_event,
+};
+#endif
+
+static struct nfnl_callback ctnl_cb[IPCTNL_MSG_MAX] = {
+	[IPCTNL_MSG_CT_NEW]		= { .call = ctnetlink_new_conntrack,
+					    .cap_required = CAP_NET_ADMIN },
+	[IPCTNL_MSG_CT_GET] 		= { .call = ctnetlink_get_conntrack,
+					    .cap_required = CAP_NET_ADMIN },
+	[IPCTNL_MSG_CT_DELETE]  	= { .call = ctnetlink_del_conntrack,
+					    .cap_required = CAP_NET_ADMIN },
+	[IPCTNL_MSG_CT_GET_CTRZERO] 	= { .call = ctnetlink_get_conntrack,
+					    .cap_required = CAP_NET_ADMIN },
+};
+
+static struct nfnl_callback ctnl_exp_cb[IPCTNL_MSG_MAX] = {
+	[IPCTNL_MSG_EXP_GET]		= { .call = ctnetlink_get_expect,
+					    .cap_required = CAP_NET_ADMIN },
+	[IPCTNL_MSG_EXP_NEW]		= { .call = ctnetlink_new_expect,
+					    .cap_required = CAP_NET_ADMIN },
+	[IPCTNL_MSG_EXP_DELETE]		= { .call = ctnetlink_del_expect,
+					    .cap_required = CAP_NET_ADMIN },
+};
+
+static struct nfnetlink_subsystem ctnl_subsys = {
+	.name				= "conntrack",
+	.subsys_id			= NFNL_SUBSYS_CTNETLINK,
+	.cb_count			= IPCTNL_MSG_MAX,
+	.attr_count			= CTA_MAX,
+	.cb				= ctnl_cb,
+};
+
+static struct nfnetlink_subsystem ctnl_exp_subsys = {
+	.name				= "conntrack_expect",
+	.subsys_id			= NFNL_SUBSYS_CTNETLINK_EXP,
+	.cb_count			= IPCTNL_MSG_EXP_MAX,
+	.attr_count			= CTA_MAX,
+	.cb				= ctnl_exp_cb,
+};
+
+static int __init ctnetlink_init(void)
+{
+	int ret;
+
+	printk("ctnetlink v%s: registering with nfnetlink.\n", version);
+	ret = nfnetlink_subsys_register(&ctnl_subsys);
+	if (ret < 0) {
+		printk("ctnetlink_init: cannot register with nfnetlink.\n");
+		goto err_out;
+	}
+
+	ret = nfnetlink_subsys_register(&ctnl_exp_subsys);
+	if (ret < 0) {
+		printk("ctnetlink_init: cannot register exp with nfnetlink.\n");
+		goto err_unreg_subsys;
+	}
+
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+	ret = ip_conntrack_register_notifier(&ctnl_notifier);
+	if (ret < 0) {
+		printk("ctnetlink_init: cannot register notifier.\n");
+		goto err_unreg_exp_subsys;
+	}
+
+	ret = ip_conntrack_expect_register_notifier(&ctnl_notifier_exp);
+	if (ret < 0) {
+		printk("ctnetlink_init: cannot expect register notifier.\n");
+		goto err_unreg_notifier;
+	}
+#endif
+
+	return 0;
+
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+err_unreg_notifier:
+	ip_conntrack_unregister_notifier(&ctnl_notifier);
+err_unreg_exp_subsys:
+	nfnetlink_subsys_unregister(&ctnl_exp_subsys);
+#endif
+err_unreg_subsys:
+	nfnetlink_subsys_unregister(&ctnl_subsys);
+err_out:
+	return ret;
+}
+
+static void __exit ctnetlink_exit(void)
+{
+	printk("ctnetlink: unregistering from nfnetlink.\n");
+
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+	ip_conntrack_unregister_notifier(&ctnl_notifier_exp);
+	ip_conntrack_unregister_notifier(&ctnl_notifier);
+#endif
+
+	nfnetlink_subsys_unregister(&ctnl_exp_subsys);
+	nfnetlink_subsys_unregister(&ctnl_subsys);
+	return;
+}
+
+module_init(ctnetlink_init);
+module_exit(ctnetlink_exit);