Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f9324952 authored by Fernando Fernandez Mancera's avatar Fernando Fernandez Mancera Committed by Pablo Neira Ayuso
Browse files

netfilter: nfnetlink_osf: extract nfnetlink_subsystem code from xt_osf.c 



Move nfnetlink osf subsystem from xt_osf.c to standalone module so we can
reuse it from the new nft_ost extension.

Signed-off-by: default avatarFernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent f6b7b5f4

include/uapi/linux/netfilter/nf_osf.h

+11 −0
Original line number Diff line number Diff line
@@ -70,6 +70,8 @@ struct nf_osf_nlmsg { 
	struct tcphdr			tcp;

};



extern struct list_head nf_osf_fingers[2];



/* Defines for IANA option kinds */

enum iana_options {

	OSFOPT_EOL = 0,		/* End of options */
@@ -94,4 +96,13 @@ enum nf_osf_attr_type { 
	OSF_ATTR_MAX,

};



/*

 * Add/remove fingerprint from the kernel.

 */

enum nf_osf_msg_types {

	OSF_MSG_ADD,

	OSF_MSG_REMOVE,

	OSF_MSG_MAX,

};



#endif /* _NF_OSF_H */

include/uapi/linux/netfilter/xt_osf.h

+1 −8
Original line number Diff line number Diff line
@@ -47,13 +47,6 @@ 
#define xt_osf_nlmsg		nf_osf_nlmsg



#define xt_osf_attr_type	nf_osf_attr_type

/*

 * Add/remove fingerprint from the kernel.

 */

enum xt_osf_msg_types {

	OSF_MSG_ADD,

	OSF_MSG_REMOVE,

	OSF_MSG_MAX,

};

#define xt_osf_msg_types	nf_osf_msg_types



#endif				/* _XT_OSF_H */

net/netfilter/nfnetlink_osf.c

+154 −0
Original line number Diff line number Diff line
@@ -20,6 +20,13 @@ 
#include <net/netfilter/nf_log.h>

#include <linux/netfilter/nf_osf.h>



/*

 * Indexed by dont-fragment bit.

 * It is the only constant value in the fingerprint.

 */

struct list_head nf_osf_fingers[2];

EXPORT_SYMBOL_GPL(nf_osf_fingers);



static inline int nf_osf_ttl(const struct sk_buff *skb,

			     int ttl_check, unsigned char f_ttl)

{
@@ -279,4 +286,151 @@ const char *nf_osf_find(const struct sk_buff *skb, 
}

EXPORT_SYMBOL_GPL(nf_osf_find);



static const struct nla_policy nfnl_osf_policy[OSF_ATTR_MAX + 1] = {

	[OSF_ATTR_FINGER]	= { .len = sizeof(struct nf_osf_user_finger) },

};



static int nfnl_osf_add_callback(struct net *net, struct sock *ctnl,

				 struct sk_buff *skb, const struct nlmsghdr *nlh,

				 const struct nlattr * const osf_attrs[],

				 struct netlink_ext_ack *extack)

{

	struct nf_osf_user_finger *f;

	struct nf_osf_finger *kf = NULL, *sf;

	int err = 0;



	if (!capable(CAP_NET_ADMIN))

		return -EPERM;



	if (!osf_attrs[OSF_ATTR_FINGER])

		return -EINVAL;



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

		return -EINVAL;



	f = nla_data(osf_attrs[OSF_ATTR_FINGER]);



	kf = kmalloc(sizeof(struct nf_osf_finger), GFP_KERNEL);

	if (!kf)

		return -ENOMEM;



	memcpy(&kf->finger, f, sizeof(struct nf_osf_user_finger));



	list_for_each_entry(sf, &nf_osf_fingers[!!f->df], finger_entry) {

		if (memcmp(&sf->finger, f, sizeof(struct nf_osf_user_finger)))

			continue;



		kfree(kf);

		kf = NULL;



		if (nlh->nlmsg_flags & NLM_F_EXCL)

			err = -EEXIST;

		break;

	}



	/*

	 * We are protected by nfnl mutex.

	 */

	if (kf)

		list_add_tail_rcu(&kf->finger_entry, &nf_osf_fingers[!!f->df]);



	return err;

}



static int nfnl_osf_remove_callback(struct net *net, struct sock *ctnl,

				    struct sk_buff *skb,

				    const struct nlmsghdr *nlh,

				    const struct nlattr * const osf_attrs[],

				    struct netlink_ext_ack *extack)

{

	struct nf_osf_user_finger *f;

	struct nf_osf_finger *sf;

	int err = -ENOENT;



	if (!capable(CAP_NET_ADMIN))

		return -EPERM;



	if (!osf_attrs[OSF_ATTR_FINGER])

		return -EINVAL;



	f = nla_data(osf_attrs[OSF_ATTR_FINGER]);



	list_for_each_entry(sf, &nf_osf_fingers[!!f->df], finger_entry) {

		if (memcmp(&sf->finger, f, sizeof(struct nf_osf_user_finger)))

			continue;



		/*

		 * We are protected by nfnl mutex.

		 */

		list_del_rcu(&sf->finger_entry);

		kfree_rcu(sf, rcu_head);



		err = 0;

		break;

	}



	return err;

}



static const struct nfnl_callback nfnl_osf_callbacks[OSF_MSG_MAX] = {

	[OSF_MSG_ADD]	= {

		.call		= nfnl_osf_add_callback,

		.attr_count	= OSF_ATTR_MAX,

		.policy		= nfnl_osf_policy,

	},

	[OSF_MSG_REMOVE]	= {

		.call		= nfnl_osf_remove_callback,

		.attr_count	= OSF_ATTR_MAX,

		.policy		= nfnl_osf_policy,

	},

};



static const struct nfnetlink_subsystem nfnl_osf_subsys = {

	.name			= "osf",

	.subsys_id		= NFNL_SUBSYS_OSF,

	.cb_count		= OSF_MSG_MAX,

	.cb			= nfnl_osf_callbacks,

};



static int __init nfnl_osf_init(void)

{

	int err = -EINVAL;

	int i;



	for (i = 0; i < ARRAY_SIZE(nf_osf_fingers); ++i)

		INIT_LIST_HEAD(&nf_osf_fingers[i]);



	err = nfnetlink_subsys_register(&nfnl_osf_subsys);

	if (err < 0) {

		pr_err("Failed to register OSF nsfnetlink helper (%d)\n", err);

		goto err_out_exit;

	}

	return 0;



err_out_exit:

	return err;

}



static void __exit nfnl_osf_fini(void)

{

	struct nf_osf_finger *f;

	int i;



	nfnetlink_subsys_unregister(&nfnl_osf_subsys);



	rcu_read_lock();

	for (i = 0; i < ARRAY_SIZE(nf_osf_fingers); ++i) {

		list_for_each_entry_rcu(f, &nf_osf_fingers[i], finger_entry) {

			list_del_rcu(&f->finger_entry);

			kfree_rcu(f, rcu_head);

		}

	}

	rcu_read_unlock();



	rcu_barrier();

}



module_init(nfnl_osf_init);

module_exit(nfnl_osf_fini);



MODULE_LICENSE("GPL");

net/netfilter/xt_osf.c

+3 −146
Original line number Diff line number Diff line
@@ -37,118 +37,6 @@ 
#include <net/netfilter/nf_log.h>

#include <linux/netfilter/xt_osf.h>



/*

 * Indexed by dont-fragment bit.

 * It is the only constant value in the fingerprint.

 */

static struct list_head xt_osf_fingers[2];



static const struct nla_policy xt_osf_policy[OSF_ATTR_MAX + 1] = {

	[OSF_ATTR_FINGER]	= { .len = sizeof(struct xt_osf_user_finger) },

};



static int xt_osf_add_callback(struct net *net, struct sock *ctnl,

			       struct sk_buff *skb, const struct nlmsghdr *nlh,

			       const struct nlattr * const osf_attrs[],

			       struct netlink_ext_ack *extack)

{

	struct xt_osf_user_finger *f;

	struct xt_osf_finger *kf = NULL, *sf;

	int err = 0;



	if (!capable(CAP_NET_ADMIN))

		return -EPERM;



	if (!osf_attrs[OSF_ATTR_FINGER])

		return -EINVAL;



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

		return -EINVAL;



	f = nla_data(osf_attrs[OSF_ATTR_FINGER]);



	kf = kmalloc(sizeof(struct xt_osf_finger), GFP_KERNEL);

	if (!kf)

		return -ENOMEM;



	memcpy(&kf->finger, f, sizeof(struct xt_osf_user_finger));



	list_for_each_entry(sf, &xt_osf_fingers[!!f->df], finger_entry) {

		if (memcmp(&sf->finger, f, sizeof(struct xt_osf_user_finger)))

			continue;



		kfree(kf);

		kf = NULL;



		if (nlh->nlmsg_flags & NLM_F_EXCL)

			err = -EEXIST;

		break;

	}



	/*

	 * We are protected by nfnl mutex.

	 */

	if (kf)

		list_add_tail_rcu(&kf->finger_entry, &xt_osf_fingers[!!f->df]);



	return err;

}



static int xt_osf_remove_callback(struct net *net, struct sock *ctnl,

				  struct sk_buff *skb,

				  const struct nlmsghdr *nlh,

				  const struct nlattr * const osf_attrs[],

				  struct netlink_ext_ack *extack)

{

	struct xt_osf_user_finger *f;

	struct xt_osf_finger *sf;

	int err = -ENOENT;



	if (!capable(CAP_NET_ADMIN))

		return -EPERM;



	if (!osf_attrs[OSF_ATTR_FINGER])

		return -EINVAL;



	f = nla_data(osf_attrs[OSF_ATTR_FINGER]);



	list_for_each_entry(sf, &xt_osf_fingers[!!f->df], finger_entry) {

		if (memcmp(&sf->finger, f, sizeof(struct xt_osf_user_finger)))

			continue;



		/*

		 * We are protected by nfnl mutex.

		 */

		list_del_rcu(&sf->finger_entry);

		kfree_rcu(sf, rcu_head);



		err = 0;

		break;

	}



	return err;

}



static const struct nfnl_callback xt_osf_nfnetlink_callbacks[OSF_MSG_MAX] = {

	[OSF_MSG_ADD]	= {

		.call		= xt_osf_add_callback,

		.attr_count	= OSF_ATTR_MAX,

		.policy		= xt_osf_policy,

	},

	[OSF_MSG_REMOVE]	= {

		.call		= xt_osf_remove_callback,

		.attr_count	= OSF_ATTR_MAX,

		.policy		= xt_osf_policy,

	},

};



static const struct nfnetlink_subsystem xt_osf_nfnetlink = {

	.name			= "osf",

	.subsys_id		= NFNL_SUBSYS_OSF,

	.cb_count		= OSF_MSG_MAX,

	.cb			= xt_osf_nfnetlink_callbacks,

};



static bool

xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p)

{
@@ -159,7 +47,7 @@ xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p) 
		return false;



	return nf_osf_match(skb, xt_family(p), xt_hooknum(p), xt_in(p),

			    xt_out(p), info, net, xt_osf_fingers);

			    xt_out(p), info, net, nf_osf_fingers);

}



static struct xt_match xt_osf_match = {
@@ -177,52 +65,21 @@ static struct xt_match xt_osf_match = { 


static int __init xt_osf_init(void)

{

	int err = -EINVAL;

	int i;



	for (i=0; i<ARRAY_SIZE(xt_osf_fingers); ++i)

		INIT_LIST_HEAD(&xt_osf_fingers[i]);



	err = nfnetlink_subsys_register(&xt_osf_nfnetlink);

	if (err < 0) {

		pr_err("Failed to register OSF nsfnetlink helper (%d)\n", err);

		goto err_out_exit;

	}

	int err;



	err = xt_register_match(&xt_osf_match);

	if (err) {

		pr_err("Failed to register OS fingerprint "

		       "matching module (%d)\n", err);

		goto err_out_remove;

		return err;

	}



	return 0;



err_out_remove:

	nfnetlink_subsys_unregister(&xt_osf_nfnetlink);

err_out_exit:

	return err;

}



static void __exit xt_osf_fini(void)

{

	struct xt_osf_finger *f;

	int i;



	nfnetlink_subsys_unregister(&xt_osf_nfnetlink);

	xt_unregister_match(&xt_osf_match);



	rcu_read_lock();

	for (i=0; i<ARRAY_SIZE(xt_osf_fingers); ++i) {



		list_for_each_entry_rcu(f, &xt_osf_fingers[i], finger_entry) {

			list_del_rcu(&f->finger_entry);

			kfree_rcu(f, rcu_head);

		}

	}

	rcu_read_unlock();



	rcu_barrier();

}



module_init(xt_osf_init);