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Commit e8bfdb9d authored by Paul Moore's avatar Paul Moore Committed by James Morris
Browse files

SELinux: Convert the netif code to use ifindex values 



The current SELinux netif code requires the caller have a valid net_device
struct pointer to lookup network interface information.  However, we don't
always have a valid net_device pointer so convert the netif code to use
the ifindex values we always have as part of the sk_buff.  This patch also
removes the default message SID from the network interface record, it is
not being used and therefore is "dead code".

Signed-off-by: default avatarPaul Moore <paul.moore@hp.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 75e22910

security/selinux/hooks.c

+2 −2
Original line number Diff line number Diff line
@@ -3853,7 +3853,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, 
	if (!skb->dev)

		goto out;



	err = sel_netif_sids(skb->dev, &if_sid, NULL);

	err = sel_netif_sid(skb->iif, &if_sid);

	if (err)

		goto out;
@@ -4178,7 +4178,7 @@ static int selinux_ip_postroute_last_compat(struct sock *sk, struct net_device * 


	isec = inode->i_security;

	

	err = sel_netif_sids(dev, &if_sid, NULL);

	err = sel_netif_sid(dev->ifindex, &if_sid);

	if (err)

		goto out;

security/selinux/include/netif.h

+3 −1
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
 * Author: James Morris <jmorris@redhat.com>

 *

 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>

 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.

 *                    Paul Moore, <paul.moore@hp.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2,
@@ -15,7 +17,7 @@ 
#ifndef _SELINUX_NETIF_H_

#define _SELINUX_NETIF_H_



int sel_netif_sids(struct net_device *dev, u32 *if_sid, u32 *msg_sid);

int sel_netif_sid(int ifindex, u32 *sid);



#endif	/* _SELINUX_NETIF_H_ */

security/selinux/include/objsec.h

+2 −3
Original line number Diff line number Diff line
@@ -96,9 +96,8 @@ struct bprm_security_struct { 
};



struct netif_security_struct {

	struct net_device *dev;		/* back pointer */

	u32 if_sid;			/* SID for this interface */

	u32 msg_sid;			/* default SID for messages received on this interface */

	int ifindex;			/* device index */

	u32 sid;			/* SID for this interface */

};



struct sk_security_struct {

security/selinux/include/security.h

+1 −2
Original line number Diff line number Diff line
@@ -77,8 +77,7 @@ int security_get_user_sids(u32 callsid, char *username, 
int security_port_sid(u16 domain, u16 type, u8 protocol, u16 port,

	u32 *out_sid);



int security_netif_sid(char *name, u32 *if_sid,

	u32 *msg_sid);

int security_netif_sid(char *name, u32 *if_sid);



int security_node_sid(u16 domain, void *addr, u32 addrlen,

	u32 *out_sid);

security/selinux/netif.c

+145 −109
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
 * Author: James Morris <jmorris@redhat.com>

 *

 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>

 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.

 *                    Paul Moore <paul.moore@hp.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2,
@@ -29,14 +31,6 @@ 
#define SEL_NETIF_HASH_SIZE	64

#define SEL_NETIF_HASH_MAX	1024



#undef DEBUG



#ifdef DEBUG

#define DEBUGP printk

#else

#define DEBUGP(format, args...)

#endif



struct sel_netif

{

	struct list_head list;
@@ -49,174 +43,217 @@ static LIST_HEAD(sel_netif_list); 
static DEFINE_SPINLOCK(sel_netif_lock);

static struct list_head sel_netif_hash[SEL_NETIF_HASH_SIZE];



static inline u32 sel_netif_hasfn(struct net_device *dev)

/**

 * sel_netif_hashfn - Hashing function for the interface table

 * @ifindex: the network interface

 *

 * Description:

 * This is the hashing function for the network interface table, it returns the

 * bucket number for the given interface.

 *

 */

static inline u32 sel_netif_hashfn(int ifindex)

{

	return (dev->ifindex & (SEL_NETIF_HASH_SIZE - 1));

	return (ifindex & (SEL_NETIF_HASH_SIZE - 1));

}



/*

 * All of the devices should normally fit in the hash, so we optimize

 * for that case.

/**

 * sel_netif_find - Search for an interface record

 * @ifindex: the network interface

 *

 * Description:

 * Search the network interface table and return the record matching @ifindex.

 * If an entry can not be found in the table return NULL.

 *

 */

static inline struct sel_netif *sel_netif_find(struct net_device *dev)

static inline struct sel_netif *sel_netif_find(int ifindex)

{

	struct list_head *pos;

	int idx = sel_netif_hasfn(dev);

	int idx = sel_netif_hashfn(ifindex);

	struct sel_netif *netif;



	__list_for_each_rcu(pos, &sel_netif_hash[idx]) {

		struct sel_netif *netif = list_entry(pos,

		                                     struct sel_netif, list);

		if (likely(netif->nsec.dev == dev))

	list_for_each_entry_rcu(netif, &sel_netif_hash[idx], list)

		/* all of the devices should normally fit in the hash, so we

		 * optimize for that case */

		if (likely(netif->nsec.ifindex == ifindex))

			return netif;

	}



	return NULL;

}



/**

 * sel_netif_insert - Insert a new interface into the table

 * @netif: the new interface record

 *

 * Description:

 * Add a new interface record to the network interface hash table.  Returns

 * zero on success, negative values on failure.

 *

 */

static int sel_netif_insert(struct sel_netif *netif)

{

	int idx, ret = 0;

	int idx;

	

	if (sel_netif_total >= SEL_NETIF_HASH_MAX) {

		ret = -ENOSPC;

		goto out;

	}

	if (sel_netif_total >= SEL_NETIF_HASH_MAX)

		return -ENOSPC;

	

	idx = sel_netif_hasfn(netif->nsec.dev);

	idx = sel_netif_hashfn(netif->nsec.ifindex);

	list_add_rcu(&netif->list, &sel_netif_hash[idx]);

	sel_netif_total++;

out:

	return ret;



	return 0;

}



/**

 * sel_netif_free - Frees an interface entry

 * @p: the entry's RCU field

 *

 * Description:

 * This function is designed to be used as a callback to the call_rcu()

 * function so that memory allocated to a hash table interface entry can be

 * released safely.

 *

 */

static void sel_netif_free(struct rcu_head *p)

{

	struct sel_netif *netif = container_of(p, struct sel_netif, rcu_head);



	DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);

	kfree(netif);

}



/**

 * sel_netif_destroy - Remove an interface record from the table

 * @netif: the existing interface record

 *

 * Description:

 * Remove an existing interface record from the network interface table.

 *

 */

static void sel_netif_destroy(struct sel_netif *netif)

{

	DEBUGP("%s: %s\n", __FUNCTION__, netif->nsec.dev->name);



	list_del_rcu(&netif->list);

	sel_netif_total--;

	call_rcu(&netif->rcu_head, sel_netif_free);

}



static struct sel_netif *sel_netif_lookup(struct net_device *dev)

/**

 * sel_netif_sid_slow - Lookup the SID of a network interface using the policy

 * @ifindex: the network interface

 * @sid: interface SID

 *

 * Description:

 * This function determines the SID of a network interface by quering the

 * security policy.  The result is added to the network interface table to

 * speedup future queries.  Returns zero on success, negative values on

 * failure.

 *

 */

static int sel_netif_sid_slow(int ifindex, u32 *sid)

{

	int ret;

	struct sel_netif *netif, *new;

	struct netif_security_struct *nsec;



	netif = sel_netif_find(dev);

	if (likely(netif != NULL))

		goto out;

	struct sel_netif *netif;

	struct sel_netif *new = NULL;

	struct net_device *dev;



	new = kzalloc(sizeof(*new), GFP_ATOMIC);

	if (!new) {

		netif = ERR_PTR(-ENOMEM);

		goto out;

	}

	/* NOTE: we always use init's network namespace since we don't

	 * currently support containers */



	nsec = &new->nsec;

	dev = dev_get_by_index(&init_net, ifindex);

	if (dev == NULL)

		return -ENOENT;



	ret = security_netif_sid(dev->name, &nsec->if_sid, &nsec->msg_sid);

	if (ret < 0) {

		kfree(new);

		netif = ERR_PTR(ret);

	spin_lock_bh(&sel_netif_lock);

	netif = sel_netif_find(ifindex);

	if (netif != NULL) {

		*sid = netif->nsec.sid;

		ret = 0;

		goto out;

	}



	nsec->dev = dev;

	

	spin_lock_bh(&sel_netif_lock);

	

	netif = sel_netif_find(dev);

	if (netif) {

		spin_unlock_bh(&sel_netif_lock);

		kfree(new);

	new = kzalloc(sizeof(*new), GFP_ATOMIC);

	if (new == NULL) {

		ret = -ENOMEM;

		goto out;

	}

	

	ret = security_netif_sid(dev->name, &new->nsec.sid);

	if (ret != 0)

		goto out;

	new->nsec.ifindex = ifindex;

	ret = sel_netif_insert(new);

	spin_unlock_bh(&sel_netif_lock);

	

	if (ret) {

		kfree(new);

		netif = ERR_PTR(ret);

	if (ret != 0)

		goto out;

	}



	netif = new;

	*sid = new->nsec.sid;



	DEBUGP("new: ifindex=%u name=%s if_sid=%u msg_sid=%u\n", dev->ifindex, dev->name,

	        nsec->if_sid, nsec->msg_sid);

out:

	return netif;

}



static void sel_netif_assign_sids(u32 if_sid_in, u32 msg_sid_in, u32 *if_sid_out, u32 *msg_sid_out)

{

	if (if_sid_out)

		*if_sid_out = if_sid_in;

	if (msg_sid_out)

		*msg_sid_out = msg_sid_in;

}



static int sel_netif_sids_slow(struct net_device *dev, u32 *if_sid, u32 *msg_sid)

{

	int ret = 0;

	u32 tmp_if_sid, tmp_msg_sid;

	

	ret = security_netif_sid(dev->name, &tmp_if_sid, &tmp_msg_sid);

	if (!ret)

		sel_netif_assign_sids(tmp_if_sid, tmp_msg_sid, if_sid, msg_sid);

	spin_unlock_bh(&sel_netif_lock);

	dev_put(dev);

	if (ret != 0)

		kfree(new);

	return ret;

}



int sel_netif_sids(struct net_device *dev, u32 *if_sid, u32 *msg_sid)

/**

 * sel_netif_sid - Lookup the SID of a network interface

 * @ifindex: the network interface

 * @sid: interface SID

 *

 * Description:

 * This function determines the SID of a network interface using the fastest

 * method possible.  First the interface table is queried, but if an entry

 * can't be found then the policy is queried and the result is added to the

 * table to speedup future queries.  Returns zero on success, negative values

 * on failure.

 *

 */

int sel_netif_sid(int ifindex, u32 *sid)

{

	int ret = 0;

	struct sel_netif *netif;



	rcu_read_lock();

	netif = sel_netif_lookup(dev);

	if (IS_ERR(netif)) {

	netif = sel_netif_find(ifindex);

	if (likely(netif != NULL)) {

		*sid = netif->nsec.sid;

		rcu_read_unlock();

		ret = sel_netif_sids_slow(dev, if_sid, msg_sid);

		goto out;

		return 0;

	}

	sel_netif_assign_sids(netif->nsec.if_sid, netif->nsec.msg_sid, if_sid, msg_sid);

	rcu_read_unlock();

out:

	return ret;



	return sel_netif_sid_slow(ifindex, sid);

}



static void sel_netif_kill(struct net_device *dev)

/**

 * sel_netif_kill - Remove an entry from the network interface table

 * @ifindex: the network interface

 *

 * Description:

 * This function removes the entry matching @ifindex from the network interface

 * table if it exists.

 *

 */

static void sel_netif_kill(int ifindex)

{

	struct sel_netif *netif;



	spin_lock_bh(&sel_netif_lock);

	netif = sel_netif_find(dev);

	netif = sel_netif_find(ifindex);

	if (netif)

		sel_netif_destroy(netif);

	spin_unlock_bh(&sel_netif_lock);

}



/**

 * sel_netif_flush - Flush the entire network interface table

 *

 * Description:

 * Remove all entries from the network interface table.

 *

 */

static void sel_netif_flush(void)

{

	int idx;



	spin_lock_bh(&sel_netif_lock);

	for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) {

	struct sel_netif *netif;



	spin_lock_bh(&sel_netif_lock);

	for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++)

		list_for_each_entry(netif, &sel_netif_hash[idx], list)

			sel_netif_destroy(netif);

	}

	spin_unlock_bh(&sel_netif_lock);

}
@@ -239,7 +276,7 @@ static int sel_netif_netdev_notifier_handler(struct notifier_block *this, 
		return NOTIFY_DONE;



	if (event == NETDEV_DOWN)

		sel_netif_kill(dev);

		sel_netif_kill(dev->ifindex);



	return NOTIFY_DONE;

}
@@ -250,10 +287,10 @@ static struct notifier_block sel_netif_netdev_notifier = { 


static __init int sel_netif_init(void)

{

	int i, err = 0;

	int i, err;

	

	if (!selinux_enabled)

		goto out;

		return 0;



	for (i = 0; i < SEL_NETIF_HASH_SIZE; i++)

		INIT_LIST_HEAD(&sel_netif_hash[i]);
@@ -265,7 +302,6 @@ static __init int sel_netif_init(void) 
	if (err)

		panic("avc_add_callback() failed, error %d\n", err);



out:

	return err;

}