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: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
Paul Moore 2008-01-29 08:38:08 -05:00 committed by James Morris
parent 75e22910cf
commit e8bfdb9d0d
6 changed files with 155 additions and 125 deletions

View File

@ -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;

View File

@ -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_ */

View File

@ -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 {

View File

@ -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);

View File

@ -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;
struct sel_netif *netif;
struct sel_netif *new = NULL;
struct net_device *dev;
netif = sel_netif_find(dev);
if (likely(netif != NULL))
goto out;
new = kzalloc(sizeof(*new), GFP_ATOMIC);
if (!new) {
netif = ERR_PTR(-ENOMEM);
goto out;
}
nsec = &new->nsec;
/* NOTE: we always use init's network namespace since we don't
* currently support containers */
ret = security_netif_sid(dev->name, &nsec->if_sid, &nsec->msg_sid);
if (ret < 0) {
kfree(new);
netif = ERR_PTR(ret);
goto out;
}
dev = dev_get_by_index(&init_net, ifindex);
if (dev == NULL)
return -ENOENT;
nsec->dev = dev;
spin_lock_bh(&sel_netif_lock);
netif = sel_netif_find(dev);
if (netif) {
spin_unlock_bh(&sel_netif_lock);
kfree(new);
netif = sel_netif_find(ifindex);
if (netif != NULL) {
*sid = netif->nsec.sid;
ret = 0;
goto out;
}
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;
}
*sid = new->nsec.sid;
netif = new;
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;
struct sel_netif *netif;
spin_lock_bh(&sel_netif_lock);
for (idx = 0; idx < SEL_NETIF_HASH_SIZE; idx++) {
struct sel_netif *netif;
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;
}

View File

@ -1478,11 +1478,8 @@ out:
* security_netif_sid - Obtain the SID for a network interface.
* @name: interface name
* @if_sid: interface SID
* @msg_sid: default SID for received packets
*/
int security_netif_sid(char *name,
u32 *if_sid,
u32 *msg_sid)
int security_netif_sid(char *name, u32 *if_sid)
{
int rc = 0;
struct ocontext *c;
@ -1510,11 +1507,8 @@ int security_netif_sid(char *name,
goto out;
}
*if_sid = c->sid[0];
*msg_sid = c->sid[1];
} else {
} else
*if_sid = SECINITSID_NETIF;
*msg_sid = SECINITSID_NETMSG;
}
out:
POLICY_RDUNLOCK;