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Commit ae243bee authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: ctnetlink: add CTA_HELP_INFO attribute 



This attribute can be used to modify and to dump the internal
protocol information.

Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 8c88f87c

include/linux/netfilter/nfnetlink_conntrack.h

+1 −0
Original line number Diff line number Diff line
@@ -191,6 +191,7 @@ enum ctattr_expect_nat { 
enum ctattr_help {

	CTA_HELP_UNSPEC,

	CTA_HELP_NAME,

	CTA_HELP_INFO,

	__CTA_HELP_MAX

};

#define CTA_HELP_MAX (__CTA_HELP_MAX - 1)

include/net/netfilter/nf_conntrack_helper.h

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ struct nf_conntrack_helper { 


	void (*destroy)(struct nf_conn *ct);



	int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);

	int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);

	unsigned int expect_class_max;

};

net/netfilter/nf_conntrack_netlink.c

+18 −5
Original line number Diff line number Diff line
@@ -902,7 +902,8 @@ static const struct nla_policy help_nla_policy[CTA_HELP_MAX+1] = { 
};



static inline int

ctnetlink_parse_help(const struct nlattr *attr, char **helper_name)

ctnetlink_parse_help(const struct nlattr *attr, char **helper_name,

		     struct nlattr **helpinfo)

{

	struct nlattr *tb[CTA_HELP_MAX+1];
@@ -913,6 +914,9 @@ ctnetlink_parse_help(const struct nlattr *attr, char **helper_name) 


	*helper_name = nla_data(tb[CTA_HELP_NAME]);



	if (tb[CTA_HELP_INFO])

		*helpinfo = tb[CTA_HELP_INFO];



	return 0;

}
@@ -1173,13 +1177,14 @@ ctnetlink_change_helper(struct nf_conn *ct, const struct nlattr * const cda[]) 
	struct nf_conntrack_helper *helper;

	struct nf_conn_help *help = nfct_help(ct);

	char *helpname = NULL;

	struct nlattr *helpinfo = NULL;

	int err;



	/* don't change helper of sibling connections */

	if (ct->master)

		return -EBUSY;



	err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);

	err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);

	if (err < 0)

		return err;
@@ -1214,8 +1219,12 @@ ctnetlink_change_helper(struct nf_conn *ct, const struct nlattr * const cda[]) 
	}



	if (help) {

		if (help->helper == helper)

		if (help->helper == helper) {

			/* update private helper data if allowed. */

			if (helper->from_nlattr && helpinfo)

				helper->from_nlattr(helpinfo, ct);

			return 0;

		}

		if (help->helper)

			return -EBUSY;

		/* need to zero data of old helper */
@@ -1411,8 +1420,9 @@ ctnetlink_create_conntrack(struct net *net, u16 zone, 
	rcu_read_lock();

 	if (cda[CTA_HELP]) {

		char *helpname = NULL;

		struct nlattr *helpinfo = NULL;



 		err = ctnetlink_parse_help(cda[CTA_HELP], &helpname);

		err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);

 		if (err < 0)

			goto err2;
@@ -1446,6 +1456,9 @@ ctnetlink_create_conntrack(struct net *net, u16 zone, 
				err = -ENOMEM;

				goto err2;

			}

			/* set private helper data if allowed. */

			if (helper->from_nlattr && helpinfo)

				helper->from_nlattr(helpinfo, ct);



			/* not in hash table yet so not strictly necessary */

			RCU_INIT_POINTER(help->helper, helper);