ffb733c650
Testing revealed a problem with the NetLabel cache where a cached entry could be freed while in use by the LSM layer causing an oops and other problems. This patch fixes that problem by introducing a reference counter to the cache entry so that it is only freed when it is no longer in use. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
255 lines
6.4 KiB
C
255 lines
6.4 KiB
C
/*
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* NetLabel Kernel API
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*
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* This file defines the kernel API for the NetLabel system. The NetLabel
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* system manages static and dynamic label mappings for network protocols such
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* as CIPSO and RIPSO.
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*
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* Author: Paul Moore <paul.moore@hp.com>
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*
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*/
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/*
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* (c) Copyright Hewlett-Packard Development Company, L.P., 2006
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/init.h>
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#include <linux/types.h>
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#include <net/ip.h>
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#include <net/netlabel.h>
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#include <net/cipso_ipv4.h>
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#include <asm/bug.h>
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#include "netlabel_domainhash.h"
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#include "netlabel_unlabeled.h"
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#include "netlabel_user.h"
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/*
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* LSM Functions
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*/
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/**
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* netlbl_socket_setattr - Label a socket using the correct protocol
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* @sock: the socket to label
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* @secattr: the security attributes
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*
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* Description:
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* Attach the correct label to the given socket using the security attributes
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* specified in @secattr. This function requires exclusive access to
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* @sock->sk, which means it either needs to be in the process of being
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* created or locked via lock_sock(sock->sk). Returns zero on success,
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* negative values on failure.
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*
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*/
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int netlbl_socket_setattr(const struct socket *sock,
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const struct netlbl_lsm_secattr *secattr)
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{
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int ret_val = -ENOENT;
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struct netlbl_dom_map *dom_entry;
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rcu_read_lock();
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dom_entry = netlbl_domhsh_getentry(secattr->domain);
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if (dom_entry == NULL)
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goto socket_setattr_return;
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switch (dom_entry->type) {
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case NETLBL_NLTYPE_CIPSOV4:
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ret_val = cipso_v4_socket_setattr(sock,
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dom_entry->type_def.cipsov4,
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secattr);
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break;
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case NETLBL_NLTYPE_UNLABELED:
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ret_val = 0;
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break;
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default:
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ret_val = -ENOENT;
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}
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socket_setattr_return:
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rcu_read_unlock();
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return ret_val;
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}
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/**
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* netlbl_sock_getattr - Determine the security attributes of a sock
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* @sk: the sock
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* @secattr: the security attributes
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*
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* Description:
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* Examines the given sock to see any NetLabel style labeling has been
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* applied to the sock, if so it parses the socket label and returns the
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* security attributes in @secattr. Returns zero on success, negative values
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* on failure.
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*
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*/
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int netlbl_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
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{
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int ret_val;
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ret_val = cipso_v4_sock_getattr(sk, secattr);
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if (ret_val == 0)
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return 0;
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return netlbl_unlabel_getattr(secattr);
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}
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/**
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* netlbl_socket_getattr - Determine the security attributes of a socket
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* @sock: the socket
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* @secattr: the security attributes
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*
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* Description:
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* Examines the given socket to see any NetLabel style labeling has been
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* applied to the socket, if so it parses the socket label and returns the
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* security attributes in @secattr. Returns zero on success, negative values
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* on failure.
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*
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*/
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int netlbl_socket_getattr(const struct socket *sock,
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struct netlbl_lsm_secattr *secattr)
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{
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int ret_val;
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ret_val = cipso_v4_socket_getattr(sock, secattr);
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if (ret_val == 0)
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return 0;
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return netlbl_unlabel_getattr(secattr);
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}
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/**
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* netlbl_skbuff_getattr - Determine the security attributes of a packet
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* @skb: the packet
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* @secattr: the security attributes
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*
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* Description:
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* Examines the given packet to see if a recognized form of packet labeling
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* is present, if so it parses the packet label and returns the security
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* attributes in @secattr. Returns zero on success, negative values on
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* failure.
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*
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*/
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int netlbl_skbuff_getattr(const struct sk_buff *skb,
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struct netlbl_lsm_secattr *secattr)
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{
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int ret_val;
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ret_val = cipso_v4_skbuff_getattr(skb, secattr);
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if (ret_val == 0)
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return 0;
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return netlbl_unlabel_getattr(secattr);
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}
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/**
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* netlbl_skbuff_err - Handle a LSM error on a sk_buff
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* @skb: the packet
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* @error: the error code
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*
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* Description:
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* Deal with a LSM problem when handling the packet in @skb, typically this is
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* a permission denied problem (-EACCES). The correct action is determined
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* according to the packet's labeling protocol.
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*
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*/
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void netlbl_skbuff_err(struct sk_buff *skb, int error)
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{
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if (CIPSO_V4_OPTEXIST(skb))
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cipso_v4_error(skb, error, 0);
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}
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/**
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* netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
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*
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* Description:
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* For all of the NetLabel protocols that support some form of label mapping
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* cache, invalidate the cache. Returns zero on success, negative values on
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* error.
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*
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*/
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void netlbl_cache_invalidate(void)
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{
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cipso_v4_cache_invalidate();
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}
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/**
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* netlbl_cache_add - Add an entry to a NetLabel protocol cache
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* @skb: the packet
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* @secattr: the packet's security attributes
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*
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* Description:
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* Add the LSM security attributes for the given packet to the underlying
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* NetLabel protocol's label mapping cache. Returns zero on success, negative
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* values on error.
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*
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*/
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int netlbl_cache_add(const struct sk_buff *skb,
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const struct netlbl_lsm_secattr *secattr)
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{
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if (secattr->cache == NULL)
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return -ENOMSG;
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if (CIPSO_V4_OPTEXIST(skb))
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return cipso_v4_cache_add(skb, secattr);
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return -ENOMSG;
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}
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/*
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* Setup Functions
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*/
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/**
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* netlbl_init - Initialize NetLabel
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*
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* Description:
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* Perform the required NetLabel initialization before first use.
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*
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*/
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static int __init netlbl_init(void)
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{
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int ret_val;
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printk(KERN_INFO "NetLabel: Initializing\n");
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printk(KERN_INFO "NetLabel: domain hash size = %u\n",
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(1 << NETLBL_DOMHSH_BITSIZE));
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printk(KERN_INFO "NetLabel: protocols ="
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" UNLABELED"
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" CIPSOv4"
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"\n");
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ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
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if (ret_val != 0)
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goto init_failure;
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ret_val = netlbl_netlink_init();
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if (ret_val != 0)
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goto init_failure;
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ret_val = netlbl_unlabel_defconf();
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if (ret_val != 0)
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goto init_failure;
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printk(KERN_INFO "NetLabel: unlabeled traffic allowed by default\n");
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return 0;
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init_failure:
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panic("NetLabel: failed to initialize properly (%d)\n", ret_val);
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}
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subsys_initcall(netlbl_init);
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