This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / net / ipv4 / netfilter / ip_conntrack_netlink.c
diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
new file mode 100644 (file)
index 0000000..01bd7ca
--- /dev/null
@@ -0,0 +1,1671 @@
+/* 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) 2005-2006 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/interrupt.h>
+#include <linux/notifier.h>
+
+#include <linux/netfilter.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)
+{
+       int ret = 0;
+       struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_PROTO);
+
+       NFA_PUT(skb, CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);
+
+       if (likely(proto->tuple_to_nfattr))
+               ret = proto->tuple_to_nfattr(skb, tuple);
+       
+       NFA_NEST_END(skb, nest_parms);
+
+       return ret;
+
+nfattr_failure:
+       return -1;
+}
+
+static inline int
+ctnetlink_dump_tuples_ip(struct sk_buff *skb,
+                        const struct ip_conntrack_tuple *tuple)
+{
+       struct nfattr *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);
+
+       return 0;
+
+nfattr_failure:
+       return -1;
+}
+
+static inline int
+ctnetlink_dump_tuples(struct sk_buff *skb,
+                     const struct ip_conntrack_tuple *tuple)
+{
+       int ret;
+       struct ip_conntrack_protocol *proto;
+
+       ret = ctnetlink_dump_tuples_ip(skb, tuple);
+       if (unlikely(ret < 0))
+               return ret;
+
+       proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
+       ret = ctnetlink_dump_tuples_proto(skb, tuple, proto);
+       ip_conntrack_proto_put(proto);
+
+       return ret;
+}
+
+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->to_nfattr) {
+               ip_conntrack_proto_put(proto);
+               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, strlen(ct->helper->name), 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_int32_t tmp;
+
+       tmp = htonl(ct->counters[dir].packets);
+       NFA_PUT(skb, CTA_COUNTERS32_PACKETS, sizeof(u_int32_t), &tmp);
+
+       tmp = htonl(ct->counters[dir].bytes);
+       NFA_PUT(skb, CTA_COUNTERS32_BYTES, sizeof(u_int32_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)
+{
+       u_int32_t 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, group;
+
+       /* ignore our fake conntrack entry */
+       if (ct == &ip_conntrack_untracked)
+               return NOTIFY_DONE;
+
+       if (events & IPCT_DESTROY) {
+               type = IPCTNL_MSG_CT_DELETE;
+               group = NFNLGRP_CONNTRACK_DESTROY;
+       } else if (events & (IPCT_NEW | IPCT_RELATED)) {
+               type = IPCTNL_MSG_CT_NEW;
+               flags = NLM_F_CREATE|NLM_F_EXCL;
+               /* dump everything */
+               events = ~0UL;
+               group = NFNLGRP_CONNTRACK_NEW;
+       } else if (events & (IPCT_STATUS |
+                     IPCT_PROTOINFO |
+                     IPCT_HELPER |
+                     IPCT_HELPINFO |
+                     IPCT_NATINFO)) {
+               type = IPCTNL_MSG_CT_NEW;
+               group = NFNLGRP_CONNTRACK_UPDATE;
+       } else 
+               return NOTIFY_DONE;
+
+       if (!nfnetlink_has_listeners(group))
+               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;
+
+       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, group, 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_prev(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_prev(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 size_t 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__);
+
+       nfattr_parse_nested(tb, CTA_IP_MAX, attr);
+
+       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;
+}
+
+static const size_t cta_min_proto[CTA_PROTO_MAX] = {
+       [CTA_PROTO_NUM-1]       = sizeof(u_int8_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__);
+
+       nfattr_parse_nested(tb, CTA_PROTO_MAX, attr);
+
+       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_int8_t *)NFA_DATA(tb[CTA_PROTO_NUM-1]);
+
+       proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
+
+       if (likely(proto->nfattr_to_tuple))
+               ret = proto->nfattr_to_tuple(tb, tuple);
+       
+       ip_conntrack_proto_put(proto);
+       
+       return ret;
+}
+
+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(tuple, 0, sizeof(*tuple));
+
+       nfattr_parse_nested(tb, CTA_TUPLE_MAX, cda[type-1]);
+
+       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;
+}
+
+#ifdef CONFIG_IP_NF_NAT_NEEDED
+static const size_t 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__);
+
+       nfattr_parse_nested(tb, CTA_PROTONAT_MAX, attr);
+
+       if (nfattr_bad_size(tb, CTA_PROTONAT_MAX, cta_min_protonat))
+               return -EINVAL;
+
+       npt = ip_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
+
+       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;
+}
+
+static const size_t cta_min_nat[CTA_NAT_MAX] = {
+       [CTA_NAT_MINIP-1]       = sizeof(u_int32_t),
+       [CTA_NAT_MAXIP-1]       = sizeof(u_int32_t),
+};
+
+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(range, 0, sizeof(*range));
+       
+       nfattr_parse_nested(tb, CTA_NAT_MAX, cda[CTA_NAT-1]);
+
+       if (nfattr_bad_size(tb, CTA_NAT_MAX, cta_min_nat))
+               return -EINVAL;
+
+       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;
+}
+#endif
+
+static inline int
+ctnetlink_parse_help(struct nfattr *attr, char **helper_name)
+{
+       struct nfattr *tb[CTA_HELP_MAX];
+
+       DEBUGP("entered %s\n", __FUNCTION__);
+
+       nfattr_parse_nested(tb, CTA_HELP_MAX, attr);
+
+       if (!tb[CTA_HELP_NAME-1])
+               return -EINVAL;
+
+       *helper_name = NFA_DATA(tb[CTA_HELP_NAME-1]);
+
+       return 0;
+}
+
+static const size_t cta_min[CTA_MAX] = {
+       [CTA_STATUS-1]          = sizeof(u_int32_t),
+       [CTA_TIMEOUT-1]         = sizeof(u_int32_t),
+       [CTA_MARK-1]            = sizeof(u_int32_t),
+       [CTA_USE-1]             = sizeof(u_int32_t),
+       [CTA_ID-1]              = sizeof(u_int32_t)
+};
+
+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 (nfattr_bad_size(cda, CTA_MAX, cta_min))
+               return -EINVAL;
+
+       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))
+               ct->timeout.function((unsigned long)ct);
+
+       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 (nfattr_bad_size(cda, CTA_MAX, cta_min))
+               return -EINVAL;
+
+       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_KERNEL);
+       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 free;
+
+       err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);
+       if (err < 0)
+               goto out;
+
+       DEBUGP("leaving\n");
+       return 0;
+
+free:
+       kfree_skb(skb2);
+out:
+       return err;
+}
+
+static inline int
+ctnetlink_change_status(struct ip_conntrack *ct, struct nfattr *cda[])
+{
+       unsigned long d;
+       unsigned status = ntohl(*(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, HOOK2MANIP(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 inline int
+ctnetlink_change_protoinfo(struct ip_conntrack *ct, struct nfattr *cda[])
+{
+       struct nfattr *tb[CTA_PROTOINFO_MAX], *attr = cda[CTA_PROTOINFO-1];
+       struct ip_conntrack_protocol *proto;
+       u_int16_t npt = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
+       int err = 0;
+
+       nfattr_parse_nested(tb, CTA_PROTOINFO_MAX, attr);
+
+       proto = ip_conntrack_proto_find_get(npt);
+
+       if (proto->from_nfattr)
+               err = proto->from_nfattr(tb, ct);
+       ip_conntrack_proto_put(proto); 
+
+       return err;
+}
+
+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;
+       }
+
+       if (cda[CTA_PROTOINFO-1]) {
+               err = ctnetlink_change_protoinfo(ct, cda);
+               if (err < 0)
+                       return err;
+       }
+
+#if defined(CONFIG_IP_NF_CONNTRACK_MARK)
+       if (cda[CTA_MARK-1])
+               ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
+#endif
+
+       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;
+
+       if (cda[CTA_PROTOINFO-1]) {
+               err = ctnetlink_change_protoinfo(ct, cda);
+               if (err < 0)
+                       return err;
+       }
+
+#if defined(CONFIG_IP_NF_CONNTRACK_MARK)
+       if (cda[CTA_MARK-1])
+               ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
+#endif
+
+       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 (nfattr_bad_size(cda, CTA_MAX, cta_min))
+               return -EINVAL;
+
+       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);
+               return err;
+       }
+       /* implicit '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_mask(struct sk_buff *skb,
+                       const struct ip_conntrack_tuple *tuple,
+                       const struct ip_conntrack_tuple *mask)
+{
+       int ret;
+       struct ip_conntrack_protocol *proto;
+       struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);
+
+       ret = ctnetlink_dump_tuples_ip(skb, mask);
+       if (unlikely(ret < 0))
+               goto nfattr_failure;
+
+       proto = ip_conntrack_proto_find_get(tuple->dst.protonum);
+       ret = ctnetlink_dump_tuples_proto(skb, mask, proto);
+       ip_conntrack_proto_put(proto);
+       if (unlikely(ret < 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)
+{
+       struct ip_conntrack *master = exp->master;
+       u_int32_t timeout = htonl((exp->timeout.expires - jiffies) / HZ);
+       u_int32_t id = htonl(exp->id);
+
+       if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)
+               goto nfattr_failure;
+       if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)
+               goto nfattr_failure;
+       if (ctnetlink_exp_dump_tuple(skb,
+                                &master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
+                                CTA_EXPECT_MASTER) < 0)
+               goto nfattr_failure;
+       
+       NFA_PUT(skb, CTA_EXPECT_TIMEOUT, sizeof(timeout), &timeout);
+       NFA_PUT(skb, CTA_EXPECT_ID, sizeof(u_int32_t), &id);
+
+       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;
+
+       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_EXP << 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;
+       nfnetlink_send(skb, 0, NFNLGRP_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_prev(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 const size_t cta_min_exp[CTA_EXPECT_MAX] = {
+       [CTA_EXPECT_TIMEOUT-1]          = sizeof(u_int32_t),
+       [CTA_EXPECT_ID-1]               = sizeof(u_int32_t)
+};
+
+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 (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
+               return -EINVAL;
+
+       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_EXPECT_MASTER-1])
+               err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASTER);
+       else
+               return -EINVAL;
+
+       if (err < 0)
+               return err;
+
+       exp = ip_conntrack_expect_find(&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;
+               }
+       }       
+
+       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 free;
+
+       ip_conntrack_expect_put(exp);
+
+       return netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);
+
+free:
+       kfree_skb(skb2);
+out:
+       ip_conntrack_expect_put(exp);
+       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;
+
+       if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
+               return -EINVAL;
+
+       if (cda[CTA_EXPECT_TUPLE-1]) {
+               /* delete a single expect by tuple */
+               err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE);
+               if (err < 0)
+                       return err;
+
+               /* bump usage count to 2 */
+               exp = ip_conntrack_expect_find(&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);
+       } else if (cda[CTA_EXPECT_HELP_NAME-1]) {
+               char *name = NFA_DATA(cda[CTA_EXPECT_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_unlink_expect(exp);
+                               ip_conntrack_expect_put(exp);
+                       }
+               }
+               write_unlock_bh(&ip_conntrack_lock);
+       } 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_unlink_expect(exp);
+                               ip_conntrack_expect_put(exp);
+                       }
+               }
+               write_unlock_bh(&ip_conntrack_lock);
+       }
+
+       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__);
+
+       /* caller guarantees that those three CTA_EXPECT_* exist */
+       err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE);
+       if (err < 0)
+               return err;
+       err = ctnetlink_parse_tuple(cda, &mask, CTA_EXPECT_MASK);
+       if (err < 0)
+               return err;
+       err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_EXPECT_MASTER);
+       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->flags = 0;
+       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 (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))
+               return -EINVAL;
+
+       if (!cda[CTA_EXPECT_TUPLE-1]
+           || !cda[CTA_EXPECT_MASK-1]
+           || !cda[CTA_EXPECT_MASTER-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,
+                                           .attr_count = CTA_MAX, },
+       [IPCTNL_MSG_CT_GET]             = { .call = ctnetlink_get_conntrack,
+                                           .attr_count = CTA_MAX, },
+       [IPCTNL_MSG_CT_DELETE]          = { .call = ctnetlink_del_conntrack,
+                                           .attr_count = CTA_MAX, },
+       [IPCTNL_MSG_CT_GET_CTRZERO]     = { .call = ctnetlink_get_conntrack,
+                                           .attr_count = CTA_MAX, },
+};
+
+static struct nfnl_callback ctnl_exp_cb[IPCTNL_MSG_EXP_MAX] = {
+       [IPCTNL_MSG_EXP_GET]            = { .call = ctnetlink_get_expect,
+                                           .attr_count = CTA_EXPECT_MAX, },
+       [IPCTNL_MSG_EXP_NEW]            = { .call = ctnetlink_new_expect,
+                                           .attr_count = CTA_EXPECT_MAX, },
+       [IPCTNL_MSG_EXP_DELETE]         = { .call = ctnetlink_del_expect,
+                                           .attr_count = CTA_EXPECT_MAX, },
+};
+
+static struct nfnetlink_subsystem ctnl_subsys = {
+       .name                           = "conntrack",
+       .subsys_id                      = NFNL_SUBSYS_CTNETLINK,
+       .cb_count                       = IPCTNL_MSG_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,
+       .cb                             = ctnl_exp_cb,
+};
+
+MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK);
+MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_EXP);
+
+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_expect_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);