nf_contrack_netlink.c

/* Connection tracking via netlink socket. Allows for user space

 * protocol helpers and general trouble making from userspace.

 *

 * (C) 2001 by Jay Schulist <[email protected]>

 * (C) 2002-2006 by Harald Welte <[email protected]>

 * (C) 2003 by Patrick Mchardy <[email protected]>

 * (C) 2005-2006 by Pablo Neira Ayuso <[email protected]>

 *

 * 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.

 *

 * Derived from ip_conntrack_netlink.c: Port by Pablo Neira Ayuso (05/11/14)

 */



#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 <net/netfilter/nf_conntrack.h>

#include <net/netfilter/nf_conntrack_core.h>

#include <net/netfilter/nf_conntrack_expect.h>

#include <net/netfilter/nf_conntrack_helper.h>

#include <net/netfilter/nf_conntrack_l3proto.h>

#include <net/netfilter/nf_conntrack_l4proto.h>

#include <net/netfilter/nf_conntrack_tuple.h>

#ifdef CONFIG_NF_NAT_NEEDED

#include <net/netfilter/nf_nat_core.h>

#include <net/netfilter/nf_nat_protocol.h>

#endif



#include <linux/netfilter/nfnetlink.h>

#include <linux/netfilter/nfnetlink_conntrack.h>



MODULE_LICENSE("GPL");



static char __initdata version[] = "0.93";



static inline int

ctnetlink_dump_tuples_proto(struct sk_buff *skb,

			    const struct nf_conntrack_tuple *tuple,

			    struct nf_conntrack_l4proto *l4proto)

{

	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(l4proto->tuple_to_nfattr))

		ret = l4proto->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 nf_conntrack_tuple *tuple,

			 struct nf_conntrack_l3proto *l3proto)

{

	int ret = 0;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_TUPLE_IP);



	if (likely(l3proto->tuple_to_nfattr))

		ret = l3proto->tuple_to_nfattr(skb, tuple);



	NFA_NEST_END(skb, nest_parms);



	return ret;



nfattr_failure:

	return -1;

}



static inline int

ctnetlink_dump_tuples(struct sk_buff *skb,

		      const struct nf_conntrack_tuple *tuple)

{

	int ret;

	struct nf_conntrack_l3proto *l3proto;

	struct nf_conntrack_l4proto *l4proto;



	l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);

	ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto);

	nf_ct_l3proto_put(l3proto);



	if (unlikely(ret < 0))

		return ret;



	l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum);

	ret = ctnetlink_dump_tuples_proto(skb, tuple, l4proto);

	nf_ct_l4proto_put(l4proto);



	return ret;

}



static inline int

ctnetlink_dump_status(struct sk_buff *skb, const struct nf_conn *ct)

{

	__be32 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 nf_conn *ct)

{

	long timeout_l = ct->timeout.expires - jiffies;

	__be32 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 nf_conn *ct)

{

	struct nf_conntrack_l4proto *l4proto = nf_ct_l4proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num, ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);

	struct nfattr *nest_proto;

	int ret;



	if (!l4proto->to_nfattr) {

		nf_ct_l4proto_put(l4proto);

		return 0;

	}



	nest_proto = NFA_NEST(skb, CTA_PROTOINFO);



	ret = l4proto->to_nfattr(skb, nest_proto, ct);



	nf_ct_l4proto_put(l4proto);



	NFA_NEST_END(skb, nest_proto);



	return ret;



nfattr_failure:

	nf_ct_l4proto_put(l4proto);

	return -1;

}



static inline int

ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct nf_conn *ct)

{

	struct nfattr *nest_helper;

	const struct nf_conn_help *help = nfct_help(ct);



	if (!help || !help->helper)

		return 0;



	nest_helper = NFA_NEST(skb, CTA_HELP);

	NFA_PUT(skb, CTA_HELP_NAME, strlen(help->helper->name), help->helper->name);



	if (help->helper->to_nfattr)

		help->helper->to_nfattr(skb, ct);



	NFA_NEST_END(skb, nest_helper);



	return 0;



nfattr_failure:

	return -1;

}



#ifdef CONFIG_NF_CT_ACCT

static inline int

ctnetlink_dump_counters(struct sk_buff *skb, const struct nf_conn *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);

	__be32 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_NF_CONNTRACK_MARK

static inline int

ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)

{

	__be32 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 nf_conn *ct)

{

	__be32 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 nf_conn *ct)

{

	__be32 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 nf_conn *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 =

		ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;

	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_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 nf_conn *ct = (struct nf_conn *)ptr;

	struct sk_buff *skb;

	unsigned int type;

	unsigned char *b;

	unsigned int flags = 0, group;



	/* ignore our fake conntrack entry */

	if (ct == &nf_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;

		group = NFNLGRP_CONNTRACK_NEW;

	} else  if (events & (IPCT_STATUS | IPCT_PROTOINFO)) {

		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 = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;

	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 (events & IPCT_DESTROY) {

		if (ctnetlink_dump_counters(skb, ct, IP_CT_DIR_ORIGINAL) < 0 ||

		    ctnetlink_dump_counters(skb, ct, IP_CT_DIR_REPLY) < 0)

			goto nfattr_failure;

	} else {

		if (ctnetlink_dump_status(skb, ct) < 0)

			goto nfattr_failure;



		if (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_HELPER || nfct_help(ct))

		    && ctnetlink_dump_helpinfo(skb, ct) < 0)

			goto nfattr_failure;



#ifdef CONFIG_NF_CONNTRACK_MARK

		if ((events & IPCT_MARK || ct->mark)

		    && ctnetlink_dump_mark(skb, ct) < 0)

			goto nfattr_failure;

#endif



		if (events & IPCT_COUNTER_FILLING &&

		    (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_NF_CONNTRACK_EVENTS */



static int ctnetlink_done(struct netlink_callback *cb)

{

	if (cb->args[1])

		nf_ct_put((struct nf_conn *)cb->args[1]);

	return 0;

}



#define L3PROTO(ct) ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num



static int

ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct nf_conn *ct, *last;

	struct nf_conntrack_tuple_hash *h;

	struct list_head *i;

	struct nfgenmsg *nfmsg = NLMSG_DATA(cb->nlh);

	u_int8_t l3proto = nfmsg->nfgen_family;



	read_lock_bh(&nf_conntrack_lock);

	last = (struct nf_conn *)cb->args[1];

	for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) {

restart:

		list_for_each_prev(i, &nf_conntrack_hash[cb->args[0]]) {

			h = (struct nf_conntrack_tuple_hash *) i;

			if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)

				continue;

			ct = nf_ct_tuplehash_to_ctrack(h);

			/* Dump entries of a given L3 protocol number.

			 * If it is not specified, ie. l3proto == 0,

			 * then dump everything. */

			if (l3proto && L3PROTO(ct) != l3proto)

				continue;

			if (cb->args[1]) {

				if (ct != last)

					continue;

				cb->args[1] = 0;

			}

			if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid,

						cb->nlh->nlmsg_seq,

						IPCTNL_MSG_CT_NEW,

						1, ct) < 0) {

				nf_conntrack_get(&ct->ct_general);

				cb->args[1] = (unsigned long)ct;

				goto out;

			}

#ifdef CONFIG_NF_CT_ACCT

			if (NFNL_MSG_TYPE(cb->nlh->nlmsg_type) ==

						IPCTNL_MSG_CT_GET_CTRZERO)

				memset(&ct->counters, 0, sizeof(ct->counters));

#endif

		}

		if (cb->args[1]) {

			cb->args[1] = 0;

			goto restart;

		}

	}

out:

	read_unlock_bh(&nf_conntrack_lock);

	if (last)

		nf_ct_put(last);



	return skb->len;

}



static inline int

ctnetlink_parse_tuple_ip(struct nfattr *attr, struct nf_conntrack_tuple *tuple)

{

	struct nfattr *tb[CTA_IP_MAX];

	struct nf_conntrack_l3proto *l3proto;

	int ret = 0;



	nfattr_parse_nested(tb, CTA_IP_MAX, attr);



	l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);



	if (likely(l3proto->nfattr_to_tuple))

		ret = l3proto->nfattr_to_tuple(tb, tuple);



	nf_ct_l3proto_put(l3proto);



	return ret;

}



static const size_t cta_min_proto[CTA_PROTO_MAX] = {

	[CTA_PROTO_NUM-1]	= sizeof(u_int8_t),

};



static inline int

ctnetlink_parse_tuple_proto(struct nfattr *attr,

			    struct nf_conntrack_tuple *tuple)

{

	struct nfattr *tb[CTA_PROTO_MAX];

	struct nf_conntrack_l4proto *l4proto;

	int ret = 0;



	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]);



	l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum);



	if (likely(l4proto->nfattr_to_tuple))

		ret = l4proto->nfattr_to_tuple(tb, tuple);



	nf_ct_l4proto_put(l4proto);



	return ret;

}



static inline int

ctnetlink_parse_tuple(struct nfattr *cda[], struct nf_conntrack_tuple *tuple,

		      enum ctattr_tuple type, u_int8_t l3num)

{

	struct nfattr *tb[CTA_TUPLE_MAX];

	int err;



	memset(tuple, 0, sizeof(*tuple));



	nfattr_parse_nested(tb, CTA_TUPLE_MAX, cda[type-1]);



	if (!tb[CTA_TUPLE_IP-1])

		return -EINVAL;



	tuple->src.l3num = l3num;



	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;



	return 0;

}



#ifdef CONFIG_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 nfnetlink_parse_nat_proto(struct nfattr *attr,

				     const struct nf_conn *ct,

				     struct nf_nat_range *range)

{

	struct nfattr *tb[CTA_PROTONAT_MAX];

	struct nf_nat_protocol *npt;



	nfattr_parse_nested(tb, CTA_PROTONAT_MAX, attr);



	if (nfattr_bad_size(tb, CTA_PROTONAT_MAX, cta_min_protonat))

		return -EINVAL;



	npt = nf_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);



	if (!npt->nfattr_to_range) {

		nf_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;



	nf_nat_proto_put(npt);



	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

nfnetlink_parse_nat(struct nfattr *nat,

		    const struct nf_conn *ct, struct nf_nat_range *range)

{

	struct nfattr *tb[CTA_NAT_MAX];

	int err;



	memset(range, 0, sizeof(*range));



	nfattr_parse_nested(tb, CTA_NAT_MAX, nat);



	if (nfattr_bad_size(tb, CTA_NAT_MAX, cta_min_nat))

		return -EINVAL;



	if (tb[CTA_NAT_MINIP-1])

		range->min_ip = *(__be32 *)NFA_DATA(tb[CTA_NAT_MINIP-1]);



	if (!tb[CTA_NAT_MAXIP-1])

		range->max_ip = range->min_ip;

	else

		range->max_ip = *(__be32 *)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 = nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO-1], ct, range);

	if (err < 0)

		return err;



	return 0;

}

#endif



static inline int

ctnetlink_parse_help(struct nfattr *attr, char **helper_name)

{

	struct nfattr *tb[CTA_HELP_MAX];



	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 nf_conntrack_tuple_hash *h;

	struct nf_conntrack_tuple tuple;

	struct nf_conn *ct;

	struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);

	u_int8_t u3 = nfmsg->nfgen_family;

	int err = 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, u3);

	else if (cda[CTA_TUPLE_REPLY-1])

		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY, u3);

	else {

		/* Flush the whole table */

		nf_conntrack_flush();

		return 0;

	}



	if (err < 0)

		return err;



	h = nf_conntrack_find_get(&tuple, NULL);

	if (!h)

		return -ENOENT;



	ct = nf_ct_tuplehash_to_ctrack(h);



	if (cda[CTA_ID-1]) {

		u_int32_t id = ntohl(*(__be32 *)NFA_DATA(cda[CTA_ID-1]));

		if (ct->id != id) {

			nf_ct_put(ct);

			return -ENOENT;

		}

	}

	if (del_timer(&ct->timeout))

		ct->timeout.function((unsigned long)ct);



	nf_ct_put(ct);



	return 0;

}



static int

ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,

			struct nlmsghdr *nlh, struct nfattr *cda[], int *errp)

{

	struct nf_conntrack_tuple_hash *h;

	struct nf_conntrack_tuple tuple;

	struct nf_conn *ct;

	struct sk_buff *skb2 = NULL;

	struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);

	u_int8_t u3 = nfmsg->nfgen_family;

	int err = 0;



	if (nlh->nlmsg_flags & NLM_F_DUMP) {

		u32 rlen;



#ifndef CONFIG_NF_CT_ACCT

		if (NFNL_MSG_TYPE(nlh->nlmsg_type) == IPCTNL_MSG_CT_GET_CTRZERO)

			return -ENOTSUPP;

#endif

		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, u3);

	else if (cda[CTA_TUPLE_REPLY-1])

		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY, u3);

	else

		return -EINVAL;



	if (err < 0)

		return err;



	h = nf_conntrack_find_get(&tuple, NULL);

	if (!h)

		return -ENOENT;



	ct = nf_ct_tuplehash_to_ctrack(h);



	err = -ENOMEM;

	skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb2) {

		nf_ct_put(ct);

		return -ENOMEM;

	}



	err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).pid, nlh->nlmsg_seq,

				  IPCTNL_MSG_CT_NEW, 1, ct);

	nf_ct_put(ct);

	if (err <= 0)

		goto free;



	err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);

	if (err < 0)

		goto out;



	return 0;



free:

	kfree_skb(skb2);

out:

	return err;

}



static inline int

ctnetlink_change_status(struct nf_conn *ct, struct nfattr *cda[])

{

	unsigned long d;

	unsigned int status = ntohl(*(__be32 *)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_SRC-1] || cda[CTA_NAT_DST-1]) {

#ifndef CONFIG_NF_NAT_NEEDED

		return -EINVAL;

#else

		struct nf_nat_range range;



		if (cda[CTA_NAT_DST-1]) {

			if (nfnetlink_parse_nat(cda[CTA_NAT_DST-1], ct,

						&range) < 0)

				return -EINVAL;

			if (nf_nat_initialized(ct,

					       HOOK2MANIP(NF_IP_PRE_ROUTING)))

				return -EEXIST;

			nf_nat_setup_info(ct, &range, NF_IP_PRE_ROUTING);

		}

		if (cda[CTA_NAT_SRC-1]) {

			if (nfnetlink_parse_nat(cda[CTA_NAT_SRC-1], ct,

						&range) < 0)

				return -EINVAL;

			if (nf_nat_initialized(ct,

					       HOOK2MANIP(NF_IP_POST_ROUTING)))

				return -EEXIST;

			nf_nat_setup_info(ct, &range, NF_IP_POST_ROUTING);

		}

#endif

	}



	/* Be careful here, modifying NAT bits can screw up things,

	 * so don't let users modify them directly if they don't pass

	 * nf_nat_range. */

	ct->status |= status & ~(IPS_NAT_DONE_MASK | IPS_NAT_MASK);

	return 0;

}





static inline int

ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[])

{

	struct nf_conntrack_helper *helper;

	struct nf_conn_help *help = nfct_help(ct);

	char *helpname;

	int err;



	if (!help) {

		/* FIXME: we need to reallocate and rehash */

		return -EBUSY;

	}



	/* 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 = __nf_conntrack_helper_find_byname(helpname);

	if (!helper) {

		if (!strcmp(helpname, ""))

			helper = NULL;

		else

			return -EINVAL;

	}



	if (help->helper) {

		if (!helper) {

			/* we had a helper before ... */

			nf_ct_remove_expectations(ct);

			help->helper = NULL;

		} else {

			/* need to zero data of old helper */

			memset(&help->help, 0, sizeof(help->help));

		}

	}



	help->helper = helper;



	return 0;

}



static inline int

ctnetlink_change_timeout(struct nf_conn *ct, struct nfattr *cda[])

{

	u_int32_t timeout = ntohl(*(__be32 *)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 nf_conn *ct, struct nfattr *cda[])

{

	struct nfattr *tb[CTA_PROTOINFO_MAX], *attr = cda[CTA_PROTOINFO-1];

	struct nf_conntrack_l4proto *l4proto;

	u_int16_t npt = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;

	u_int16_t l3num = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;

	int err = 0;



	nfattr_parse_nested(tb, CTA_PROTOINFO_MAX, attr);



	l4proto = nf_ct_l4proto_find_get(l3num, npt);



	if (l4proto->from_nfattr)

		err = l4proto->from_nfattr(tb, ct);

	nf_ct_l4proto_put(l4proto);



	return err;

}



static int

ctnetlink_change_conntrack(struct nf_conn *ct, struct nfattr *cda[])

{

	int err;



	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_NF_CONNTRACK_MARK)

	if (cda[CTA_MARK-1])

		ct->mark = ntohl(*(__be32 *)NFA_DATA(cda[CTA_MARK-1]));

#endif



	return 0;

}



static int

ctnetlink_create_conntrack(struct nfattr *cda[],

			   struct nf_conntrack_tuple *otuple,

			   struct nf_conntrack_tuple *rtuple)

{

	struct nf_conn *ct;

	int err = -EINVAL;

	struct nf_conn_help *help;



	ct = nf_conntrack_alloc(otuple, rtuple);

	if (ct == NULL || IS_ERR(ct))

		return -ENOMEM;



	if (!cda[CTA_TIMEOUT-1])

		goto err;

	ct->timeout.expires = ntohl(*(__be32 *)NFA_DATA(cda[CTA_TIMEOUT-1]));



	ct->timeout.expires = jiffies + ct->timeout.expires * HZ;

	ct->status |= IPS_CONFIRMED;



	if (cda[CTA_STATUS-1]) {

		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)

			goto err;

	}



#if defined(CONFIG_NF_CONNTRACK_MARK)

	if (cda[CTA_MARK-1])

		ct->mark = ntohl(*(__be32 *)NFA_DATA(cda[CTA_MARK-1]));

#endif



	help = nfct_help(ct);

	if (help)

		help->helper = nf_ct_helper_find_get(rtuple);



	add_timer(&ct->timeout);

	nf_conntrack_hash_insert(ct);



	if (help && help->helper)

		nf_ct_helper_put(help->helper);



	return 0;



err:

	nf_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 nf_conntrack_tuple otuple, rtuple;

	struct nf_conntrack_tuple_hash *h = NULL;

	struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);

	u_int8_t u3 = nfmsg->nfgen_family;

	int err = 0;



	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, u3);

		if (err < 0)

			return err;

	}



	if (cda[CTA_TUPLE_REPLY-1]) {

		err = ctnetlink_parse_tuple(cda, &rtuple, CTA_TUPLE_REPLY, u3);

		if (err < 0)

			return err;

	}



	write_lock_bh(&nf_conntrack_lock);

	if (cda[CTA_TUPLE_ORIG-1])

		h = __nf_conntrack_find(&otuple, NULL);

	else if (cda[CTA_TUPLE_REPLY-1])

		h = __nf_conntrack_find(&rtuple, NULL);



	if (h == NULL) {

		write_unlock_bh(&nf_conntrack_lock);

		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_SRC-1] || cda[CTA_NAT_DST-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 */

	err = -EEXIST;

	if (!(nlh->nlmsg_flags & NLM_F_EXCL))

		err = ctnetlink_change_conntrack(nf_ct_tuplehash_to_ctrack(h), cda);



out_unlock:

	write_unlock_bh(&nf_conntrack_lock);

	return err;

}



/***********************************************************************

 * EXPECT

 ***********************************************************************/



static inline int

ctnetlink_exp_dump_tuple(struct sk_buff *skb,

			 const struct nf_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 nf_conntrack_tuple *tuple,

			const struct nf_conntrack_tuple *mask)

{

	int ret;

	struct nf_conntrack_l3proto *l3proto;

	struct nf_conntrack_l4proto *l4proto;

	struct nfattr *nest_parms = NFA_NEST(skb, CTA_EXPECT_MASK);



	l3proto = nf_ct_l3proto_find_get(tuple->src.l3num);

	ret = ctnetlink_dump_tuples_ip(skb, mask, l3proto);

	nf_ct_l3proto_put(l3proto);



	if (unlikely(ret < 0))

		goto nfattr_failure;



	l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum);

	ret = ctnetlink_dump_tuples_proto(skb, mask, l4proto);

	nf_ct_l4proto_put(l4proto);

	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 nf_conntrack_expect *exp)

{

	struct nf_conn *master = exp->master;

	__be32 timeout = htonl((exp->timeout.expires - jiffies) / HZ);

	__be32 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 nf_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 = exp->tuple.src.l3num;

	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_NF_CONNTRACK_EVENTS

static int ctnetlink_expect_event(struct notifier_block *this,

				  unsigned long events, void *ptr)

{

	struct nlmsghdr *nlh;

	struct nfgenmsg *nfmsg;

	struct nf_conntrack_expect *exp = (struct nf_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;



	if (!nfnetlink_has_listeners(NFNLGRP_CONNTRACK_EXP_NEW))

		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 = exp->tuple.src.l3num;

	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 nf_conntrack_expect *exp = NULL;

	struct list_head *i;

	u_int32_t *id = (u_int32_t *) &cb->args[0];

	struct nfgenmsg *nfmsg = NLMSG_DATA(cb->nlh);

	u_int8_t l3proto = nfmsg->nfgen_family;



	read_lock_bh(&nf_conntrack_lock);

	list_for_each_prev(i, &nf_conntrack_expect_list) {

		exp = (struct nf_conntrack_expect *) i;

		if (l3proto && exp->tuple.src.l3num != l3proto)

			continue;

		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(&nf_conntrack_lock);



	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 nf_conntrack_tuple tuple;

	struct nf_conntrack_expect *exp;

	struct sk_buff *skb2;

	struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);

	u_int8_t u3 = nfmsg->nfgen_family;

	int err = 0;



	if (nfattr_bad_size(cda, CTA_EXPECT_MAX, cta_min_exp))

		return -EINVAL;



	if (nlh->nlmsg_flags & NLM_F_DUMP) {

		u32 rlen;



		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, u3);

	else

		return -EINVAL;



	if (err < 0)

		return err;



	exp = nf_conntrack_expect_find_get(&tuple);

	if (!exp)

		return -ENOENT;



	if (cda[CTA_EXPECT_ID-1]) {

		__be32 id = *(__be32 *)NFA_DATA(cda[CTA_EXPECT_ID-1]);

		if (exp->id != ntohl(id)) {

			nf_conntrack_expect_put(exp);

			return -ENOENT;

		}

	}



	err = -ENOMEM;

	skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);

	if (!skb2)

		goto out;



	err = ctnetlink_exp_fill_info(skb2, NETLINK_CB(skb).pid,

				      nlh->nlmsg_seq, IPCTNL_MSG_EXP_NEW,

				      1, exp);

	if (err <= 0)

		goto free;



	nf_conntrack_expect_put(exp);



	return netlink_unicast(ctnl, skb2, NETLINK_CB(skb).pid, MSG_DONTWAIT);



free:

	kfree_skb(skb2);

out:

	nf_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 nf_conntrack_expect *exp, *tmp;

	struct nf_conntrack_tuple tuple;

	struct nf_conntrack_helper *h;

	struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);

	u_int8_t u3 = nfmsg->nfgen_family;

	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, u3);

		if (err < 0)

			return err;



		/* bump usage count to 2 */

		exp = nf_conntrack_expect_find_get(&tuple);

		if (!exp)

			return -ENOENT;



		if (cda[CTA_EXPECT_ID-1]) {

			__be32 id = *(__be32 *)NFA_DATA(cda[CTA_EXPECT_ID-1]);

			if (exp->id != ntohl(id)) {

				nf_conntrack_expect_put(exp);

				return -ENOENT;

			}

		}



		/* after list removal, usage count == 1 */

		nf_conntrack_unexpect_related(exp);

		/* have to put what we 'get' above.

		 * after this line usage count == 0 */

		nf_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(&nf_conntrack_lock);

		h = __nf_conntrack_helper_find_byname(name);

		if (!h) {

			write_unlock_bh(&nf_conntrack_lock);

			return -EINVAL;

		}

		list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list,

					 list) {

			struct nf_conn_help *m_help = nfct_help(exp->master);

			if (m_help->helper == h

			    && del_timer(&exp->timeout)) {

				nf_ct_unlink_expect(exp);

				nf_conntrack_expect_put(exp);

			}

		}

		write_unlock_bh(&nf_conntrack_lock);

	} else {

		/* This basically means we have to flush everything*/

		write_lock_bh(&nf_conntrack_lock);

		list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list,

					 list) {

			if (del_timer(&exp->timeout)) {

				nf_ct_unlink_expect(exp);

				nf_conntrack_expect_put(exp);

			}

		}

		write_unlock_bh(&nf_conntrack_lock);

	}



	return 0;

}

static int

ctnetlink_change_expect(struct nf_conntrack_expect *x, struct nfattr *cda[])

{

	return -EOPNOTSUPP;

}



static int

ctnetlink_create_expect(struct nfattr *cda[], u_int8_t u3)

{

	struct nf_conntrack_tuple tuple, mask, master_tuple;

	struct nf_conntrack_tuple_hash *h = NULL;

	struct nf_conntrack_expect *exp;

	struct nf_conn *ct;

	struct nf_conn_help *help;

	int err = 0;



	/* caller guarantees that those three CTA_EXPECT_* exist */

	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);

	if (err < 0)

		return err;

	err = ctnetlink_parse_tuple(cda, &mask, CTA_EXPECT_MASK, u3);

	if (err < 0)

		return err;

	err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_EXPECT_MASTER, u3);

	if (err < 0)

		return err;



	/* Look for master conntrack of this expectation */

	h = nf_conntrack_find_get(&master_tuple, NULL);

	if (!h)

		return -ENOENT;

	ct = nf_ct_tuplehash_to_ctrack(h);

	help = nfct_help(ct);



	if (!help || !help->helper) {

		/* such conntrack hasn't got any helper, abort */

		err = -EINVAL;

		goto out;

	}



	exp = nf_conntrack_expect_alloc(ct);

	if (!exp) {

		err = -ENOMEM;

		goto out;

	}



	exp->expectfn = NULL;

	exp->flags = 0;

	exp->master = ct;

	exp->helper = NULL;

	memcpy(&exp->tuple, &tuple, sizeof(struct nf_conntrack_tuple));

	memcpy(&exp->mask, &mask, sizeof(struct nf_conntrack_tuple));



	err = nf_conntrack_expect_related(exp);

	nf_conntrack_expect_put(exp);



out:

	nf_ct_put(nf_ct_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 nf_conntrack_tuple tuple;

	struct nf_conntrack_expect *exp;

	struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);

	u_int8_t u3 = nfmsg->nfgen_family;

	int err = 0;



	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, u3);

	if (err < 0)

		return err;



	write_lock_bh(&nf_conntrack_lock);

	exp = __nf_conntrack_expect_find(&tuple);



	if (!exp) {

		write_unlock_bh(&nf_conntrack_lock);

		err = -ENOENT;

		if (nlh->nlmsg_flags & NLM_F_CREATE)

			err = ctnetlink_create_expect(cda, u3);

		return err;

	}



	err = -EEXIST;

	if (!(nlh->nlmsg_flags & NLM_F_EXCL))

		err = ctnetlink_change_expect(exp, cda);

	write_unlock_bh(&nf_conntrack_lock);



	return err;

}



#ifdef CONFIG_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("ip_conntrack_netlink");

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_NF_CONNTRACK_EVENTS

	ret = nf_conntrack_register_notifier(&ctnl_notifier);

	if (ret < 0) {

		printk("ctnetlink_init: cannot register notifier.\n");

		goto err_unreg_exp_subsys;

	}



	ret = nf_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_NF_CONNTRACK_EVENTS

err_unreg_notifier:

	nf_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_NF_CONNTRACK_EVENTS

	nf_conntrack_expect_unregister_notifier(&ctnl_notifier_exp);

	nf_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);

  

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