/*
   * NetLabel Unlabeled Support
   *
   * This file defines functions for dealing with unlabeled packets for the
   * NetLabel system.  The NetLabel system manages static and dynamic label
   * mappings for network protocols such as CIPSO and RIPSO.
   *
   * Author: Paul Moore <paul.moore@hp.com>
   *
   */
  
  /*

   * (c) Copyright Hewlett-Packard Development Company, L.P., 2006 - 2008

   *
   * This program is free software;  you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY;  without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   * the GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program;  if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   *
   */
  
  #include <linux/types.h>

  #include <linux/rcupdate.h>

  #include <linux/list.h>
  #include <linux/spinlock.h>
  #include <linux/socket.h>
  #include <linux/string.h>
  #include <linux/skbuff.h>

  #include <linux/audit.h>

  #include <linux/in.h>
  #include <linux/in6.h>
  #include <linux/ip.h>
  #include <linux/ipv6.h>
  #include <linux/notifier.h>
  #include <linux/netdevice.h>
  #include <linux/security.h>

  #include <net/sock.h>
  #include <net/netlink.h>
  #include <net/genetlink.h>

  #include <net/ip.h>
  #include <net/ipv6.h>
  #include <net/net_namespace.h>

  #include <net/netlabel.h>
  #include <asm/bug.h>

  #include <asm/atomic.h>

  
  #include "netlabel_user.h"

  #include "netlabel_addrlist.h"

  #include "netlabel_domainhash.h"
  #include "netlabel_unlabeled.h"

  #include "netlabel_mgmt.h"
  
  /* NOTE: at present we always use init's network namespace since we don't
   *       presently support different namespaces even though the majority of
   *       the functions in this file are "namespace safe" */
  
  /* The unlabeled connection hash table which we use to map network interfaces
   * and addresses of unlabeled packets to a user specified secid value for the
   * LSM.  The hash table is used to lookup the network interface entry
   * (struct netlbl_unlhsh_iface) and then the interface entry is used to
   * lookup an IP address match from an ordered list.  If a network interface
   * match can not be found in the hash table then the default entry
   * (netlbl_unlhsh_def) is used.  The IP address entry list
   * (struct netlbl_unlhsh_addr) is ordered such that the entries with a
   * larger netmask come first.
   */
  struct netlbl_unlhsh_tbl {
  	struct list_head *tbl;
  	u32 size;
  };

  #define netlbl_unlhsh_addr4_entry(iter) \
  	container_of(iter, struct netlbl_unlhsh_addr4, list)

  struct netlbl_unlhsh_addr4 {

  	u32 secid;

  	struct netlbl_af4list list;

  	struct rcu_head rcu;
  };

  #define netlbl_unlhsh_addr6_entry(iter) \
  	container_of(iter, struct netlbl_unlhsh_addr6, list)

  struct netlbl_unlhsh_addr6 {

  	u32 secid;

  	struct netlbl_af6list list;

  	struct rcu_head rcu;
  };
  struct netlbl_unlhsh_iface {
  	int ifindex;
  	struct list_head addr4_list;
  	struct list_head addr6_list;
  
  	u32 valid;
  	struct list_head list;
  	struct rcu_head rcu;
  };
  
  /* Argument struct for netlbl_unlhsh_walk() */
  struct netlbl_unlhsh_walk_arg {
  	struct netlink_callback *nl_cb;
  	struct sk_buff *skb;
  	u32 seq;
  };
  
  /* Unlabeled connection hash table */
  /* updates should be so rare that having one spinlock for the entire
   * hash table should be okay */
  static DEFINE_SPINLOCK(netlbl_unlhsh_lock);
  static struct netlbl_unlhsh_tbl *netlbl_unlhsh = NULL;
  static struct netlbl_unlhsh_iface *netlbl_unlhsh_def = NULL;

  
  /* Accept unlabeled packets flag */

  static u8 netlabel_unlabel_acceptflg = 0;

  /* NetLabel Generic NETLINK unlabeled family */

  static struct genl_family netlbl_unlabel_gnl_family = {
  	.id = GENL_ID_GENERATE,
  	.hdrsize = 0,
  	.name = NETLBL_NLTYPE_UNLABELED_NAME,
  	.version = NETLBL_PROTO_VERSION,

  	.maxattr = NLBL_UNLABEL_A_MAX,

  };

  /* NetLabel Netlink attribute policy */

  static const struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {

  	[NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },

  	[NLBL_UNLABEL_A_IPV6ADDR] = { .type = NLA_BINARY,
  				      .len = sizeof(struct in6_addr) },
  	[NLBL_UNLABEL_A_IPV6MASK] = { .type = NLA_BINARY,
  				      .len = sizeof(struct in6_addr) },
  	[NLBL_UNLABEL_A_IPV4ADDR] = { .type = NLA_BINARY,
  				      .len = sizeof(struct in_addr) },
  	[NLBL_UNLABEL_A_IPV4MASK] = { .type = NLA_BINARY,
  				      .len = sizeof(struct in_addr) },
  	[NLBL_UNLABEL_A_IFACE] = { .type = NLA_NUL_STRING,
  				   .len = IFNAMSIZ - 1 },
  	[NLBL_UNLABEL_A_SECCTX] = { .type = NLA_BINARY }

  };

  
  /*

   * Unlabeled Connection Hash Table Functions
   */
  
  /**
   * netlbl_unlhsh_free_addr4 - Frees an IPv4 address entry from the hash table
   * @entry: 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 address entry can be
   * released safely.
   *
   */
  static void netlbl_unlhsh_free_addr4(struct rcu_head *entry)
  {
  	struct netlbl_unlhsh_addr4 *ptr;
  
  	ptr = container_of(entry, struct netlbl_unlhsh_addr4, rcu);
  	kfree(ptr);
  }
  
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  /**
   * netlbl_unlhsh_free_addr6 - Frees an IPv6 address entry from the hash table
   * @entry: 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 address entry can be
   * released safely.
   *
   */
  static void netlbl_unlhsh_free_addr6(struct rcu_head *entry)
  {
  	struct netlbl_unlhsh_addr6 *ptr;
  
  	ptr = container_of(entry, struct netlbl_unlhsh_addr6, rcu);
  	kfree(ptr);
  }
  #endif /* IPv6 */
  
  /**
   * netlbl_unlhsh_free_iface - Frees an interface entry from the hash table
   * @entry: 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.  It is important to note that this function does not free
   * the IPv4 and IPv6 address lists contained as part of an interface entry.  It
   * is up to the rest of the code to make sure an interface entry is only freed
   * once it's address lists are empty.
   *
   */
  static void netlbl_unlhsh_free_iface(struct rcu_head *entry)
  {
  	struct netlbl_unlhsh_iface *iface;

  	struct netlbl_af4list *iter4;
  	struct netlbl_af4list *tmp4;
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	struct netlbl_af6list *iter6;
  	struct netlbl_af6list *tmp6;
  #endif /* IPv6 */

  
  	iface = container_of(entry, struct netlbl_unlhsh_iface, rcu);
  
  	/* no need for locks here since we are the only one with access to this
  	 * structure */

  	netlbl_af4list_foreach_safe(iter4, tmp4, &iface->addr4_list) {
  		netlbl_af4list_remove_entry(iter4);
  		kfree(netlbl_unlhsh_addr4_entry(iter4));
  	}
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	netlbl_af6list_foreach_safe(iter6, tmp6, &iface->addr6_list) {
  		netlbl_af6list_remove_entry(iter6);
  		kfree(netlbl_unlhsh_addr6_entry(iter6));
  	}
  #endif /* IPv6 */

  	kfree(iface);
  }
  
  /**
   * netlbl_unlhsh_hash - Hashing function for the hash table
   * @ifindex: the network interface/device to hash
   *
   * Description:
   * This is the hashing function for the unlabeled hash table, it returns the
   * bucket number for the given device/interface.  The caller is responsible for
   * calling the rcu_read_[un]lock() functions.
   *
   */
  static u32 netlbl_unlhsh_hash(int ifindex)
  {
  	/* this is taken _almost_ directly from
  	 * security/selinux/netif.c:sel_netif_hasfn() as they do pretty much
  	 * the same thing */
  	return ifindex & (rcu_dereference(netlbl_unlhsh)->size - 1);
  }
  
  /**

   * netlbl_unlhsh_search_iface - Search for a matching interface entry
   * @ifindex: the network interface
   *
   * Description:
   * Searches the unlabeled connection hash table and returns a pointer to the
   * interface entry which matches @ifindex, otherwise NULL is returned.  The
   * caller is responsible for calling the rcu_read_[un]lock() functions.
   *
   */
  static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex)
  {
  	u32 bkt;

  	struct list_head *bkt_list;

  	struct netlbl_unlhsh_iface *iter;
  
  	bkt = netlbl_unlhsh_hash(ifindex);

  	bkt_list = &rcu_dereference(netlbl_unlhsh)->tbl[bkt];
  	list_for_each_entry_rcu(iter, bkt_list, list)

  		if (iter->valid && iter->ifindex == ifindex)
  			return iter;
  
  	return NULL;
  }
  
  /**
   * netlbl_unlhsh_search_iface_def - Search for a matching interface entry
   * @ifindex: the network interface
   *
   * Description:
   * Searches the unlabeled connection hash table and returns a pointer to the
   * interface entry which matches @ifindex.  If an exact match can not be found
   * and there is a valid default entry, the default entry is returned, otherwise
   * NULL is returned.  The caller is responsible for calling the
   * rcu_read_[un]lock() functions.
   *
   */
  static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface_def(int ifindex)
  {
  	struct netlbl_unlhsh_iface *entry;
  
  	entry = netlbl_unlhsh_search_iface(ifindex);
  	if (entry != NULL)
  		return entry;
  
  	entry = rcu_dereference(netlbl_unlhsh_def);
  	if (entry != NULL && entry->valid)
  		return entry;
  
  	return NULL;
  }
  
  /**
   * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table
   * @iface: the associated interface entry
   * @addr: IPv4 address in network byte order
   * @mask: IPv4 address mask in network byte order
   * @secid: LSM secid value for entry
   *
   * Description:
   * Add a new address entry into the unlabeled connection hash table using the
   * interface entry specified by @iface.  On success zero is returned, otherwise
   * a negative value is returned.  The caller is responsible for calling the
   * rcu_read_[un]lock() functions.
   *

   */

  static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface,
  				   const struct in_addr *addr,
  				   const struct in_addr *mask,
  				   u32 secid)
  {

  	int ret_val;

  	struct netlbl_unlhsh_addr4 *entry;

  
  	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
  	if (entry == NULL)
  		return -ENOMEM;

  	entry->list.addr = addr->s_addr & mask->s_addr;
  	entry->list.mask = mask->s_addr;
  	entry->list.valid = 1;

  	INIT_RCU_HEAD(&entry->rcu);

  	entry->secid = secid;

  
  	spin_lock(&netlbl_unlhsh_lock);

  	ret_val = netlbl_af4list_add(&entry->list, &iface->addr4_list);

  	spin_unlock(&netlbl_unlhsh_lock);

  
  	if (ret_val != 0)
  		kfree(entry);
  	return ret_val;

  }
  
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  /**
   * netlbl_unlhsh_add_addr6 - Add a new IPv6 address entry to the hash table
   * @iface: the associated interface entry
   * @addr: IPv6 address in network byte order
   * @mask: IPv6 address mask in network byte order
   * @secid: LSM secid value for entry
   *
   * Description:
   * Add a new address entry into the unlabeled connection hash table using the
   * interface entry specified by @iface.  On success zero is returned, otherwise
   * a negative value is returned.  The caller is responsible for calling the
   * rcu_read_[un]lock() functions.
   *
   */
  static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface,
  				   const struct in6_addr *addr,
  				   const struct in6_addr *mask,
  				   u32 secid)
  {

  	int ret_val;

  	struct netlbl_unlhsh_addr6 *entry;

  
  	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
  	if (entry == NULL)
  		return -ENOMEM;

  	ipv6_addr_copy(&entry->list.addr, addr);
  	entry->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
  	entry->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
  	entry->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
  	entry->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
  	ipv6_addr_copy(&entry->list.mask, mask);
  	entry->list.valid = 1;

  	INIT_RCU_HEAD(&entry->rcu);

  	entry->secid = secid;

  
  	spin_lock(&netlbl_unlhsh_lock);

  	ret_val = netlbl_af6list_add(&entry->list, &iface->addr6_list);

  	spin_unlock(&netlbl_unlhsh_lock);

  
  	if (ret_val != 0)
  		kfree(entry);

  	return 0;
  }
  #endif /* IPv6 */
  
  /**
   * netlbl_unlhsh_add_iface - Adds a new interface entry to the hash table
   * @ifindex: network interface
   *
   * Description:
   * Add a new, empty, interface entry into the unlabeled connection hash table.
   * On success a pointer to the new interface entry is returned, on failure NULL
   * is returned.  The caller is responsible for calling the rcu_read_[un]lock()
   * functions.
   *
   */
  static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex)
  {
  	u32 bkt;
  	struct netlbl_unlhsh_iface *iface;
  
  	iface = kzalloc(sizeof(*iface), GFP_ATOMIC);
  	if (iface == NULL)
  		return NULL;
  
  	iface->ifindex = ifindex;
  	INIT_LIST_HEAD(&iface->addr4_list);
  	INIT_LIST_HEAD(&iface->addr6_list);
  	iface->valid = 1;
  	INIT_RCU_HEAD(&iface->rcu);
  
  	spin_lock(&netlbl_unlhsh_lock);
  	if (ifindex > 0) {
  		bkt = netlbl_unlhsh_hash(ifindex);
  		if (netlbl_unlhsh_search_iface(ifindex) != NULL)
  			goto add_iface_failure;
  		list_add_tail_rcu(&iface->list,
  				  &rcu_dereference(netlbl_unlhsh)->tbl[bkt]);
  	} else {
  		INIT_LIST_HEAD(&iface->list);
  		if (rcu_dereference(netlbl_unlhsh_def) != NULL)
  			goto add_iface_failure;
  		rcu_assign_pointer(netlbl_unlhsh_def, iface);
  	}
  	spin_unlock(&netlbl_unlhsh_lock);
  
  	return iface;
  
  add_iface_failure:
  	spin_unlock(&netlbl_unlhsh_lock);
  	kfree(iface);
  	return NULL;
  }
  
  /**
   * netlbl_unlhsh_add - Adds a new entry to the unlabeled connection hash table
   * @net: network namespace
   * @dev_name: interface name
   * @addr: IP address in network byte order
   * @mask: address mask in network byte order
   * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)
   * @secid: LSM secid value for the entry

   * @audit_info: NetLabel audit information

   *
   * Description:
   * Adds a new entry to the unlabeled connection hash table.  Returns zero on
   * success, negative values on failure.
   *
   */

  int netlbl_unlhsh_add(struct net *net,
  		      const char *dev_name,
  		      const void *addr,
  		      const void *mask,
  		      u32 addr_len,
  		      u32 secid,
  		      struct netlbl_audit *audit_info)

  {
  	int ret_val;
  	int ifindex;
  	struct net_device *dev;
  	struct netlbl_unlhsh_iface *iface;

  	struct audit_buffer *audit_buf = NULL;
  	char *secctx = NULL;
  	u32 secctx_len;

  
  	if (addr_len != sizeof(struct in_addr) &&
  	    addr_len != sizeof(struct in6_addr))
  		return -EINVAL;
  
  	rcu_read_lock();
  	if (dev_name != NULL) {
  		dev = dev_get_by_name(net, dev_name);
  		if (dev == NULL) {
  			ret_val = -ENODEV;
  			goto unlhsh_add_return;
  		}
  		ifindex = dev->ifindex;
  		dev_put(dev);
  		iface = netlbl_unlhsh_search_iface(ifindex);
  	} else {
  		ifindex = 0;
  		iface = rcu_dereference(netlbl_unlhsh_def);
  	}
  	if (iface == NULL) {
  		iface = netlbl_unlhsh_add_iface(ifindex);
  		if (iface == NULL) {
  			ret_val = -ENOMEM;
  			goto unlhsh_add_return;
  		}
  	}

  	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCADD,
  					      audit_info);

  	switch (addr_len) {

  	case sizeof(struct in_addr): {
  		struct in_addr *addr4, *mask4;

  		addr4 = (struct in_addr *)addr;
  		mask4 = (struct in_addr *)mask;
  		ret_val = netlbl_unlhsh_add_addr4(iface, addr4, mask4, secid);
  		if (audit_buf != NULL)

  			netlbl_af4list_audit_addr(audit_buf, 1,
  						  dev_name,
  						  addr4->s_addr,
  						  mask4->s_addr);

  		break;

  	}

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

  	case sizeof(struct in6_addr): {
  		struct in6_addr *addr6, *mask6;

  		addr6 = (struct in6_addr *)addr;
  		mask6 = (struct in6_addr *)mask;
  		ret_val = netlbl_unlhsh_add_addr6(iface, addr6, mask6, secid);
  		if (audit_buf != NULL)

  			netlbl_af6list_audit_addr(audit_buf, 1,
  						  dev_name,
  						  addr6, mask6);

  		break;

  	}

  #endif /* IPv6 */
  	default:
  		ret_val = -EINVAL;
  	}
  	if (ret_val == 0)
  		atomic_inc(&netlabel_mgmt_protocount);
  
  unlhsh_add_return:
  	rcu_read_unlock();

  	if (audit_buf != NULL) {
  		if (security_secid_to_secctx(secid,
  					     &secctx,
  					     &secctx_len) == 0) {
  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
  			security_release_secctx(secctx, secctx_len);
  		}
  		audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
  		audit_log_end(audit_buf);
  	}

  	return ret_val;
  }
  
  /**
   * netlbl_unlhsh_remove_addr4 - Remove an IPv4 address entry

   * @net: network namespace

   * @iface: interface entry
   * @addr: IP address
   * @mask: IP address mask

   * @audit_info: NetLabel audit information

   *
   * Description:
   * Remove an IP address entry from the unlabeled connection hash table.
   * Returns zero on success, negative values on failure.  The caller is
   * responsible for calling the rcu_read_[un]lock() functions.
   *
   */

  static int netlbl_unlhsh_remove_addr4(struct net *net,
  				      struct netlbl_unlhsh_iface *iface,

  				      const struct in_addr *addr,

  				      const struct in_addr *mask,
  				      struct netlbl_audit *audit_info)

  {

  	struct netlbl_af4list *list_entry;

  	struct netlbl_unlhsh_addr4 *entry;

  	struct audit_buffer *audit_buf;

  	struct net_device *dev;

  	char *secctx;

  	u32 secctx_len;

  
  	spin_lock(&netlbl_unlhsh_lock);

  	list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
  					   &iface->addr4_list);

  	spin_unlock(&netlbl_unlhsh_lock);

  	if (list_entry != NULL)
  		entry = netlbl_unlhsh_addr4_entry(list_entry);
  	else

  		entry = NULL;

  	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
  					      audit_info);
  	if (audit_buf != NULL) {
  		dev = dev_get_by_index(net, iface->ifindex);

  		netlbl_af4list_audit_addr(audit_buf, 1,
  					  (dev != NULL ? dev->name : NULL),
  					  addr->s_addr, mask->s_addr);

  		if (dev != NULL)
  			dev_put(dev);

  		if (entry != NULL &&
  		    security_secid_to_secctx(entry->secid,
  					     &secctx, &secctx_len) == 0) {

  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
  			security_release_secctx(secctx, secctx_len);
  		}

  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);

  		audit_log_end(audit_buf);
  	}

  	if (entry == NULL)
  		return -ENOENT;
  
  	call_rcu(&entry->rcu, netlbl_unlhsh_free_addr4);
  	return 0;

  }
  
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  /**
   * netlbl_unlhsh_remove_addr6 - Remove an IPv6 address entry

   * @net: network namespace

   * @iface: interface entry
   * @addr: IP address
   * @mask: IP address mask

   * @audit_info: NetLabel audit information

   *
   * Description:
   * Remove an IP address entry from the unlabeled connection hash table.
   * Returns zero on success, negative values on failure.  The caller is
   * responsible for calling the rcu_read_[un]lock() functions.
   *
   */

  static int netlbl_unlhsh_remove_addr6(struct net *net,
  				      struct netlbl_unlhsh_iface *iface,

  				      const struct in6_addr *addr,

  				      const struct in6_addr *mask,
  				      struct netlbl_audit *audit_info)

  {

  	struct netlbl_af6list *list_entry;

  	struct netlbl_unlhsh_addr6 *entry;

  	struct audit_buffer *audit_buf;

  	struct net_device *dev;

  	char *secctx;

  	u32 secctx_len;

  
  	spin_lock(&netlbl_unlhsh_lock);

  	list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);

  	spin_unlock(&netlbl_unlhsh_lock);

  	if (list_entry != NULL)
  		entry = netlbl_unlhsh_addr6_entry(list_entry);
  	else

  		entry = NULL;

  	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_STCDEL,
  					      audit_info);
  	if (audit_buf != NULL) {
  		dev = dev_get_by_index(net, iface->ifindex);

  		netlbl_af6list_audit_addr(audit_buf, 1,
  					  (dev != NULL ? dev->name : NULL),
  					  addr, mask);

  		if (dev != NULL)
  			dev_put(dev);

  		if (entry != NULL &&
  		    security_secid_to_secctx(entry->secid,
  					     &secctx, &secctx_len) == 0) {

  			audit_log_format(audit_buf, " sec_obj=%s", secctx);
  			security_release_secctx(secctx, secctx_len);
  		}

  		audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);

  		audit_log_end(audit_buf);
  	}

  	if (entry == NULL)
  		return -ENOENT;
  
  	call_rcu(&entry->rcu, netlbl_unlhsh_free_addr6);
  	return 0;

  }
  #endif /* IPv6 */
  
  /**
   * netlbl_unlhsh_condremove_iface - Remove an interface entry
   * @iface: the interface entry
   *
   * Description:
   * Remove an interface entry from the unlabeled connection hash table if it is
   * empty.  An interface entry is considered to be empty if there are no
   * address entries assigned to it.
   *
   */
  static void netlbl_unlhsh_condremove_iface(struct netlbl_unlhsh_iface *iface)
  {

  	struct netlbl_af4list *iter4;
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	struct netlbl_af6list *iter6;
  #endif /* IPv6 */

  
  	spin_lock(&netlbl_unlhsh_lock);

  	netlbl_af4list_foreach_rcu(iter4, &iface->addr4_list)
  		goto unlhsh_condremove_failure;
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	netlbl_af6list_foreach_rcu(iter6, &iface->addr6_list)
  		goto unlhsh_condremove_failure;
  #endif /* IPv6 */

  	iface->valid = 0;
  	if (iface->ifindex > 0)
  		list_del_rcu(&iface->list);
  	else
  		rcu_assign_pointer(netlbl_unlhsh_def, NULL);
  	spin_unlock(&netlbl_unlhsh_lock);
  
  	call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
  	return;
  
  unlhsh_condremove_failure:
  	spin_unlock(&netlbl_unlhsh_lock);
  	return;
  }
  
  /**
   * netlbl_unlhsh_remove - Remove an entry from the unlabeled hash table
   * @net: network namespace
   * @dev_name: interface name
   * @addr: IP address in network byte order
   * @mask: address mask in network byte order
   * @addr_len: length of address/mask (4 for IPv4, 16 for IPv6)

   * @audit_info: NetLabel audit information

   *
   * Description:
   * Removes and existing entry from the unlabeled connection hash table.
   * Returns zero on success, negative values on failure.
   *
   */

  int netlbl_unlhsh_remove(struct net *net,
  			 const char *dev_name,
  			 const void *addr,
  			 const void *mask,
  			 u32 addr_len,
  			 struct netlbl_audit *audit_info)

  {
  	int ret_val;
  	struct net_device *dev;
  	struct netlbl_unlhsh_iface *iface;
  
  	if (addr_len != sizeof(struct in_addr) &&
  	    addr_len != sizeof(struct in6_addr))
  		return -EINVAL;
  
  	rcu_read_lock();
  	if (dev_name != NULL) {
  		dev = dev_get_by_name(net, dev_name);
  		if (dev == NULL) {
  			ret_val = -ENODEV;
  			goto unlhsh_remove_return;
  		}
  		iface = netlbl_unlhsh_search_iface(dev->ifindex);
  		dev_put(dev);
  	} else
  		iface = rcu_dereference(netlbl_unlhsh_def);
  	if (iface == NULL) {
  		ret_val = -ENOENT;
  		goto unlhsh_remove_return;
  	}
  	switch (addr_len) {
  	case sizeof(struct in_addr):

  		ret_val = netlbl_unlhsh_remove_addr4(net,
  						     iface, addr, mask,
  						     audit_info);

  		break;
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	case sizeof(struct in6_addr):

  		ret_val = netlbl_unlhsh_remove_addr6(net,
  						     iface, addr, mask,
  						     audit_info);

  		break;
  #endif /* IPv6 */
  	default:
  		ret_val = -EINVAL;
  	}
  	if (ret_val == 0) {
  		netlbl_unlhsh_condremove_iface(iface);
  		atomic_dec(&netlabel_mgmt_protocount);
  	}
  
  unlhsh_remove_return:
  	rcu_read_unlock();
  	return ret_val;
  }
  
  /*
   * General Helper Functions
   */
  
  /**
   * netlbl_unlhsh_netdev_handler - Network device notification handler
   * @this: notifier block
   * @event: the event
   * @ptr: the network device (cast to void)
   *
   * Description:
   * Handle network device events, although at present all we care about is a
   * network device going away.  In the case of a device going away we clear any
   * related entries from the unlabeled connection hash table.
   *
   */
  static int netlbl_unlhsh_netdev_handler(struct notifier_block *this,
  					unsigned long event,
  					void *ptr)
  {
  	struct net_device *dev = ptr;
  	struct netlbl_unlhsh_iface *iface = NULL;

  	if (!net_eq(dev_net(dev), &init_net))

  		return NOTIFY_DONE;
  
  	/* XXX - should this be a check for NETDEV_DOWN or _UNREGISTER? */
  	if (event == NETDEV_DOWN) {
  		spin_lock(&netlbl_unlhsh_lock);
  		iface = netlbl_unlhsh_search_iface(dev->ifindex);
  		if (iface != NULL && iface->valid) {
  			iface->valid = 0;
  			list_del_rcu(&iface->list);
  		} else
  			iface = NULL;
  		spin_unlock(&netlbl_unlhsh_lock);
  	}
  
  	if (iface != NULL)
  		call_rcu(&iface->rcu, netlbl_unlhsh_free_iface);
  
  	return NOTIFY_DONE;
  }

  
  /**
   * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
   * @value: desired value

   * @audit_info: NetLabel audit information

   *
   * Description:
   * Set the value of the unlabeled accept flag to @value.
   *
   */

  static void netlbl_unlabel_acceptflg_set(u8 value,
  					 struct netlbl_audit *audit_info)

  {

  	struct audit_buffer *audit_buf;
  	u8 old_val;

  	old_val = netlabel_unlabel_acceptflg;

  	netlabel_unlabel_acceptflg = value;

  	audit_buf = netlbl_audit_start_common(AUDIT_MAC_UNLBL_ALLOW,
  					      audit_info);

  	if (audit_buf != NULL) {
  		audit_log_format(audit_buf,
  				 " unlbl_accept=%u old=%u", value, old_val);
  		audit_log_end(audit_buf);
  	}

  }

  /**
   * netlbl_unlabel_addrinfo_get - Get the IPv4/6 address information
   * @info: the Generic NETLINK info block
   * @addr: the IP address
   * @mask: the IP address mask
   * @len: the address length
   *
   * Description:
   * Examine the Generic NETLINK message and extract the IP address information.
   * Returns zero on success, negative values on failure.
   *
   */
  static int netlbl_unlabel_addrinfo_get(struct genl_info *info,
  				       void **addr,
  				       void **mask,
  				       u32 *len)
  {
  	u32 addr_len;
  
  	if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR]) {
  		addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
  		if (addr_len != sizeof(struct in_addr) &&
  		    addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK]))
  			return -EINVAL;
  		*len = addr_len;
  		*addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]);
  		*mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV4MASK]);
  		return 0;
  	} else if (info->attrs[NLBL_UNLABEL_A_IPV6ADDR]) {
  		addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
  		if (addr_len != sizeof(struct in6_addr) &&
  		    addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV6MASK]))
  			return -EINVAL;
  		*len = addr_len;
  		*addr = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6ADDR]);
  		*mask = nla_data(info->attrs[NLBL_UNLABEL_A_IPV6MASK]);
  		return 0;
  	}
  
  	return -EINVAL;
  }

  /*

   * NetLabel Command Handlers
   */
  
  /**
   * netlbl_unlabel_accept - Handle an ACCEPT message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated ACCEPT message and set the accept flag accordingly.
   * Returns zero on success, negative values on failure.
   *
   */
  static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
  {

  	u8 value;

  	struct netlbl_audit audit_info;

  	if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
  		value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);

  		if (value == 1 || value == 0) {

  			netlbl_netlink_auditinfo(skb, &audit_info);
  			netlbl_unlabel_acceptflg_set(value, &audit_info);

  			return 0;

  		}
  	}

  	return -EINVAL;

  }
  
  /**
   * netlbl_unlabel_list - Handle a LIST message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated LIST message and respond with the current status.
   * Returns zero on success, negative values on failure.
   *
   */
  static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
  {

  	int ret_val = -EINVAL;

  	struct sk_buff *ans_skb;

  	void *data;

  	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

  	if (ans_skb == NULL)
  		goto list_failure;

  	data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
  				 0, NLBL_UNLABEL_C_LIST);

  	if (data == NULL) {
  		ret_val = -ENOMEM;

  		goto list_failure;

  	}

  	ret_val = nla_put_u8(ans_skb,
  			     NLBL_UNLABEL_A_ACPTFLG,

  			     netlabel_unlabel_acceptflg);

  	if (ret_val != 0)
  		goto list_failure;

  	genlmsg_end(ans_skb, data);

  	return genlmsg_reply(ans_skb, info);

  
  list_failure:

  	kfree_skb(ans_skb);

  	return ret_val;
  }

  /**
   * netlbl_unlabel_staticadd - Handle a STATICADD message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated STATICADD message and add a new unlabeled
   * connection entry to the hash table.  Returns zero on success, negative
   * values on failure.
   *
   */
  static int netlbl_unlabel_staticadd(struct sk_buff *skb,
  				    struct genl_info *info)
  {
  	int ret_val;
  	char *dev_name;
  	void *addr;
  	void *mask;
  	u32 addr_len;
  	u32 secid;

  	struct netlbl_audit audit_info;

  
  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
  	 * single entry.  However, allow users to create two entries, one each
  	 * for IPv4 and IPv4, with the same LSM security context which should
  	 * achieve the same result. */
  	if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
  	    !info->attrs[NLBL_UNLABEL_A_IFACE] ||
  	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
  	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
  		return -EINVAL;

  	netlbl_netlink_auditinfo(skb, &audit_info);

  	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
  	if (ret_val != 0)
  		return ret_val;
  	dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);
  	ret_val = security_secctx_to_secid(
  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
  				  &secid);
  	if (ret_val != 0)
  		return ret_val;
  
  	return netlbl_unlhsh_add(&init_net,

  				 dev_name, addr, mask, addr_len, secid,
  				 &audit_info);

  }
  
  /**
   * netlbl_unlabel_staticadddef - Handle a STATICADDDEF message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated STATICADDDEF message and add a new default
   * unlabeled connection entry.  Returns zero on success, negative values on
   * failure.
   *
   */
  static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
  				       struct genl_info *info)
  {
  	int ret_val;
  	void *addr;
  	void *mask;
  	u32 addr_len;
  	u32 secid;

  	struct netlbl_audit audit_info;

  
  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
  	 * single entry.  However, allow users to create two entries, one each
  	 * for IPv4 and IPv6, with the same LSM security context which should
  	 * achieve the same result. */
  	if (!info->attrs[NLBL_UNLABEL_A_SECCTX] ||
  	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
  	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
  		return -EINVAL;

  	netlbl_netlink_auditinfo(skb, &audit_info);

  	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
  	if (ret_val != 0)
  		return ret_val;
  	ret_val = security_secctx_to_secid(
  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
  				  &secid);
  	if (ret_val != 0)
  		return ret_val;

  	return netlbl_unlhsh_add(&init_net,
  				 NULL, addr, mask, addr_len, secid,
  				 &audit_info);

  }
  
  /**
   * netlbl_unlabel_staticremove - Handle a STATICREMOVE message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated STATICREMOVE message and remove the specified
   * unlabeled connection entry.  Returns zero on success, negative values on
   * failure.
   *
   */
  static int netlbl_unlabel_staticremove(struct sk_buff *skb,
  				       struct genl_info *info)
  {
  	int ret_val;
  	char *dev_name;
  	void *addr;
  	void *mask;
  	u32 addr_len;

  	struct netlbl_audit audit_info;

  
  	/* See the note in netlbl_unlabel_staticadd() about not allowing both
  	 * IPv4 and IPv6 in the same entry. */
  	if (!info->attrs[NLBL_UNLABEL_A_IFACE] ||
  	    !((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
  	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
  		return -EINVAL;

  	netlbl_netlink_auditinfo(skb, &audit_info);

  	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
  	if (ret_val != 0)
  		return ret_val;
  	dev_name = nla_data(info->attrs[NLBL_UNLABEL_A_IFACE]);

  	return netlbl_unlhsh_remove(&init_net,
  				    dev_name, addr, mask, addr_len,
  				    &audit_info);

  }
  
  /**
   * netlbl_unlabel_staticremovedef - Handle a STATICREMOVEDEF message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated STATICREMOVEDEF message and remove the default
   * unlabeled connection entry.  Returns zero on success, negative values on
   * failure.
   *
   */
  static int netlbl_unlabel_staticremovedef(struct sk_buff *skb,
  					  struct genl_info *info)
  {
  	int ret_val;
  	void *addr;
  	void *mask;
  	u32 addr_len;

  	struct netlbl_audit audit_info;

  
  	/* See the note in netlbl_unlabel_staticadd() about not allowing both
  	 * IPv4 and IPv6 in the same entry. */
  	if (!((!info->attrs[NLBL_UNLABEL_A_IPV4ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV4MASK]) ^
  	      (!info->attrs[NLBL_UNLABEL_A_IPV6ADDR] ||
  	       !info->attrs[NLBL_UNLABEL_A_IPV6MASK])))
  		return -EINVAL;

  	netlbl_netlink_auditinfo(skb, &audit_info);

  	ret_val = netlbl_unlabel_addrinfo_get(info, &addr, &mask, &addr_len);
  	if (ret_val != 0)
  		return ret_val;

  	return netlbl_unlhsh_remove(&init_net,
  				    NULL, addr, mask, addr_len,
  				    &audit_info);

  }
  
  
  /**
   * netlbl_unlabel_staticlist_gen - Generate messages for STATICLIST[DEF]
   * @cmd: command/message
   * @iface: the interface entry
   * @addr4: the IPv4 address entry
   * @addr6: the IPv6 address entry
   * @arg: the netlbl_unlhsh_walk_arg structure
   *
   * Description:
   * This function is designed to be used to generate a response for a
   * STATICLIST or STATICLISTDEF message.  When called either @addr4 or @addr6
   * can be specified, not both, the other unspecified entry should be set to
   * NULL by the caller.  Returns the size of the message on success, negative
   * values on failure.
   *
   */
  static int netlbl_unlabel_staticlist_gen(u32 cmd,
  				       const struct netlbl_unlhsh_iface *iface,
  				       const struct netlbl_unlhsh_addr4 *addr4,
  				       const struct netlbl_unlhsh_addr6 *addr6,
  				       void *arg)
  {
  	int ret_val = -ENOMEM;
  	struct netlbl_unlhsh_walk_arg *cb_arg = arg;
  	struct net_device *dev;
  	void *data;
  	u32 secid;
  	char *secctx;
  	u32 secctx_len;
  
  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
  			   cb_arg->seq, &netlbl_unlabel_gnl_family,
  			   NLM_F_MULTI, cmd);
  	if (data == NULL)
  		goto list_cb_failure;
  
  	if (iface->ifindex > 0) {
  		dev = dev_get_by_index(&init_net, iface->ifindex);

  		if (!dev) {
  			ret_val = -ENODEV;
  			goto list_cb_failure;
  		}

  		ret_val = nla_put_string(cb_arg->skb,
  					 NLBL_UNLABEL_A_IFACE, dev->name);
  		dev_put(dev);
  		if (ret_val != 0)
  			goto list_cb_failure;
  	}
  
  	if (addr4) {
  		struct in_addr addr_struct;

  		addr_struct.s_addr = addr4->list.addr;

  		ret_val = nla_put(cb_arg->skb,
  				  NLBL_UNLABEL_A_IPV4ADDR,
  				  sizeof(struct in_addr),
  				  &addr_struct);
  		if (ret_val != 0)
  			goto list_cb_failure;

  		addr_struct.s_addr = addr4->list.mask;

  		ret_val = nla_put(cb_arg->skb,
  				  NLBL_UNLABEL_A_IPV4MASK,
  				  sizeof(struct in_addr),
  				  &addr_struct);
  		if (ret_val != 0)
  			goto list_cb_failure;
  
  		secid = addr4->secid;
  	} else {
  		ret_val = nla_put(cb_arg->skb,
  				  NLBL_UNLABEL_A_IPV6ADDR,
  				  sizeof(struct in6_addr),

  				  &addr6->list.addr);

  		if (ret_val != 0)
  			goto list_cb_failure;
  
  		ret_val = nla_put(cb_arg->skb,
  				  NLBL_UNLABEL_A_IPV6MASK,
  				  sizeof(struct in6_addr),

  				  &addr6->list.mask);

  		if (ret_val != 0)
  			goto list_cb_failure;
  
  		secid = addr6->secid;
  	}
  
  	ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
  	if (ret_val != 0)
  		goto list_cb_failure;
  	ret_val = nla_put(cb_arg->skb,
  			  NLBL_UNLABEL_A_SECCTX,
  			  secctx_len,
  			  secctx);
  	security_release_secctx(secctx, secctx_len);
  	if (ret_val != 0)
  		goto list_cb_failure;
  
  	cb_arg->seq++;
  	return genlmsg_end(cb_arg->skb, data);
  
  list_cb_failure:
  	genlmsg_cancel(cb_arg->skb, data);
  	return ret_val;
  }
  
  /**
   * netlbl_unlabel_staticlist - Handle a STATICLIST message
   * @skb: the NETLINK buffer
   * @cb: the NETLINK callback
   *
   * Description:
   * Process a user generated STATICLIST message and dump the unlabeled
   * connection hash table in a form suitable for use in a kernel generated
   * STATICLIST message.  Returns the length of @skb.
   *
   */
  static int netlbl_unlabel_staticlist(struct sk_buff *skb,
  				     struct netlink_callback *cb)
  {
  	struct netlbl_unlhsh_walk_arg cb_arg;
  	u32 skip_bkt = cb->args[0];
  	u32 skip_chain = cb->args[1];
  	u32 skip_addr4 = cb->args[2];
  	u32 skip_addr6 = cb->args[3];
  	u32 iter_bkt;
  	u32 iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0;
  	struct netlbl_unlhsh_iface *iface;

  	struct list_head *iter_list;

  	struct netlbl_af4list *addr4;
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	struct netlbl_af6list *addr6;
  #endif

  
  	cb_arg.nl_cb = cb;
  	cb_arg.skb = skb;
  	cb_arg.seq = cb->nlh->nlmsg_seq;
  
  	rcu_read_lock();
  	for (iter_bkt = skip_bkt;
  	     iter_bkt < rcu_dereference(netlbl_unlhsh)->size;
  	     iter_bkt++, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0) {

  		iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt];
  		list_for_each_entry_rcu(iface, iter_list, list) {

  			if (!iface->valid ||
  			    iter_chain++ < skip_chain)
  				continue;

  			netlbl_af4list_foreach_rcu(addr4,
  						   &iface->addr4_list) {
  				if (iter_addr4++ < skip_addr4)

  					continue;
  				if (netlbl_unlabel_staticlist_gen(

  					      NLBL_UNLABEL_C_STATICLIST,
  					      iface,
  					      netlbl_unlhsh_addr4_entry(addr4),
  					      NULL,
  					      &cb_arg) < 0) {

  					iter_addr4--;
  					iter_chain--;
  					goto unlabel_staticlist_return;
  				}
  			}

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  			netlbl_af6list_foreach_rcu(addr6,
  						   &iface->addr6_list) {
  				if (iter_addr6++ < skip_addr6)

  					continue;
  				if (netlbl_unlabel_staticlist_gen(

  					      NLBL_UNLABEL_C_STATICLIST,
  					      iface,
  					      NULL,
  					      netlbl_unlhsh_addr6_entry(addr6),
  					      &cb_arg) < 0) {

  					iter_addr6--;
  					iter_chain--;
  					goto unlabel_staticlist_return;
  				}
  			}

  #endif /* IPv6 */

  		}
  	}
  
  unlabel_staticlist_return:
  	rcu_read_unlock();
  	cb->args[0] = skip_bkt;
  	cb->args[1] = skip_chain;
  	cb->args[2] = skip_addr4;
  	cb->args[3] = skip_addr6;
  	return skb->len;
  }
  
  /**
   * netlbl_unlabel_staticlistdef - Handle a STATICLISTDEF message
   * @skb: the NETLINK buffer
   * @cb: the NETLINK callback
   *
   * Description:
   * Process a user generated STATICLISTDEF message and dump the default
   * unlabeled connection entry in a form suitable for use in a kernel generated
   * STATICLISTDEF message.  Returns the length of @skb.
   *
   */
  static int netlbl_unlabel_staticlistdef(struct sk_buff *skb,
  					struct netlink_callback *cb)
  {
  	struct netlbl_unlhsh_walk_arg cb_arg;
  	struct netlbl_unlhsh_iface *iface;
  	u32 skip_addr4 = cb->args[0];
  	u32 skip_addr6 = cb->args[1];

  	u32 iter_addr4 = 0;
  	struct netlbl_af4list *addr4;
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	u32 iter_addr6 = 0;
  	struct netlbl_af6list *addr6;
  #endif

  
  	cb_arg.nl_cb = cb;
  	cb_arg.skb = skb;
  	cb_arg.seq = cb->nlh->nlmsg_seq;
  
  	rcu_read_lock();
  	iface = rcu_dereference(netlbl_unlhsh_def);
  	if (iface == NULL || !iface->valid)
  		goto unlabel_staticlistdef_return;

  	netlbl_af4list_foreach_rcu(addr4, &iface->addr4_list) {
  		if (iter_addr4++ < skip_addr4)

  			continue;
  		if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,

  					      iface,
  					      netlbl_unlhsh_addr4_entry(addr4),
  					      NULL,
  					      &cb_arg) < 0) {

  			iter_addr4--;
  			goto unlabel_staticlistdef_return;
  		}
  	}

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  	netlbl_af6list_foreach_rcu(addr6, &iface->addr6_list) {
  		if (iter_addr6++ < skip_addr6)

  			continue;
  		if (netlbl_unlabel_staticlist_gen(NLBL_UNLABEL_C_STATICLISTDEF,

  					      iface,
  					      NULL,
  					      netlbl_unlhsh_addr6_entry(addr6),
  					      &cb_arg) < 0) {

  			iter_addr6--;
  			goto unlabel_staticlistdef_return;
  		}
  	}

  #endif /* IPv6 */

  
  unlabel_staticlistdef_return:
  	rcu_read_unlock();
  	cb->args[0] = skip_addr4;
  	cb->args[1] = skip_addr6;
  	return skb->len;
  }

  
  /*
   * NetLabel Generic NETLINK Command Definitions
   */

  static struct genl_ops netlbl_unlabel_genl_ops[] = {
  	{

  	.cmd = NLBL_UNLABEL_C_STATICADD,
  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_unlabel_genl_policy,
  	.doit = netlbl_unlabel_staticadd,
  	.dumpit = NULL,

  	},
  	{

  	.cmd = NLBL_UNLABEL_C_STATICREMOVE,
  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_unlabel_genl_policy,
  	.doit = netlbl_unlabel_staticremove,
  	.dumpit = NULL,

  	},
  	{

  	.cmd = NLBL_UNLABEL_C_STATICLIST,
  	.flags = 0,
  	.policy = netlbl_unlabel_genl_policy,
  	.doit = NULL,
  	.dumpit = netlbl_unlabel_staticlist,

  	},
  	{

  	.cmd = NLBL_UNLABEL_C_STATICADDDEF,
  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_unlabel_genl_policy,
  	.doit = netlbl_unlabel_staticadddef,
  	.dumpit = NULL,

  	},
  	{

  	.cmd = NLBL_UNLABEL_C_STATICREMOVEDEF,
  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_unlabel_genl_policy,
  	.doit = netlbl_unlabel_staticremovedef,
  	.dumpit = NULL,

  	},
  	{

  	.cmd = NLBL_UNLABEL_C_STATICLISTDEF,
  	.flags = 0,
  	.policy = netlbl_unlabel_genl_policy,
  	.doit = NULL,
  	.dumpit = netlbl_unlabel_staticlistdef,

  	},
  	{

  	.cmd = NLBL_UNLABEL_C_ACCEPT,

  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_unlabel_genl_policy,

  	.doit = netlbl_unlabel_accept,
  	.dumpit = NULL,

  	},
  	{

  	.cmd = NLBL_UNLABEL_C_LIST,
  	.flags = 0,

  	.policy = netlbl_unlabel_genl_policy,

  	.doit = netlbl_unlabel_list,
  	.dumpit = NULL,

  	},

  };

  /*
   * NetLabel Generic NETLINK Protocol Functions
   */
  
  /**
   * netlbl_unlabel_genl_init - Register the Unlabeled NetLabel component
   *
   * Description:
   * Register the unlabeled packet NetLabel component with the Generic NETLINK
   * mechanism.  Returns zero on success, negative values on failure.
   *
   */

  int __init netlbl_unlabel_genl_init(void)

  {

  	return genl_register_family_with_ops(&netlbl_unlabel_gnl_family,
  		netlbl_unlabel_genl_ops, ARRAY_SIZE(netlbl_unlabel_genl_ops));

  }
  
  /*
   * NetLabel KAPI Hooks
   */

  static struct notifier_block netlbl_unlhsh_netdev_notifier = {
  	.notifier_call = netlbl_unlhsh_netdev_handler,
  };
  
  /**
   * netlbl_unlabel_init - Initialize the unlabeled connection hash table
   * @size: the number of bits to use for the hash buckets
   *
   * Description:
   * Initializes the unlabeled connection hash table and registers a network
   * device notification handler.  This function should only be called by the
   * NetLabel subsystem itself during initialization.  Returns zero on success,
   * non-zero values on error.
   *
   */

  int __init netlbl_unlabel_init(u32 size)

  {
  	u32 iter;
  	struct netlbl_unlhsh_tbl *hsh_tbl;
  
  	if (size == 0)
  		return -EINVAL;
  
  	hsh_tbl = kmalloc(sizeof(*hsh_tbl), GFP_KERNEL);
  	if (hsh_tbl == NULL)
  		return -ENOMEM;
  	hsh_tbl->size = 1 << size;
  	hsh_tbl->tbl = kcalloc(hsh_tbl->size,
  			       sizeof(struct list_head),
  			       GFP_KERNEL);
  	if (hsh_tbl->tbl == NULL) {
  		kfree(hsh_tbl);
  		return -ENOMEM;
  	}
  	for (iter = 0; iter < hsh_tbl->size; iter++)
  		INIT_LIST_HEAD(&hsh_tbl->tbl[iter]);
  
  	rcu_read_lock();
  	spin_lock(&netlbl_unlhsh_lock);
  	rcu_assign_pointer(netlbl_unlhsh, hsh_tbl);
  	spin_unlock(&netlbl_unlhsh_lock);
  	rcu_read_unlock();
  
  	register_netdevice_notifier(&netlbl_unlhsh_netdev_notifier);
  
  	return 0;
  }

  /**
   * netlbl_unlabel_getattr - Get the security attributes for an unlabled packet

   * @skb: the packet
   * @family: protocol family

   * @secattr: the security attributes
   *
   * Description:
   * Determine the security attributes, if any, for an unlabled packet and return
   * them in @secattr.  Returns zero on success and negative values on failure.
   *
   */

  int netlbl_unlabel_getattr(const struct sk_buff *skb,
  			   u16 family,
  			   struct netlbl_lsm_secattr *secattr)

  {

  	struct netlbl_unlhsh_iface *iface;
  
  	rcu_read_lock();
  	iface = netlbl_unlhsh_search_iface_def(skb->iif);
  	if (iface == NULL)
  		goto unlabel_getattr_nolabel;
  	switch (family) {

  	case PF_INET: {
  		struct iphdr *hdr4;

  		struct netlbl_af4list *addr4;

  		hdr4 = ip_hdr(skb);

  		addr4 = netlbl_af4list_search(hdr4->saddr,
  					      &iface->addr4_list);

  		if (addr4 == NULL)
  			goto unlabel_getattr_nolabel;

  		secattr->attr.secid = netlbl_unlhsh_addr4_entry(addr4)->secid;

  		break;

  	}

  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

  	case PF_INET6: {
  		struct ipv6hdr *hdr6;

  		struct netlbl_af6list *addr6;

  		hdr6 = ipv6_hdr(skb);

  		addr6 = netlbl_af6list_search(&hdr6->saddr,
  					      &iface->addr6_list);

  		if (addr6 == NULL)
  			goto unlabel_getattr_nolabel;

  		secattr->attr.secid = netlbl_unlhsh_addr6_entry(addr6)->secid;

  		break;

  	}

  #endif /* IPv6 */
  	default:
  		goto unlabel_getattr_nolabel;
  	}
  	rcu_read_unlock();
  
  	secattr->flags |= NETLBL_SECATTR_SECID;
  	secattr->type = NETLBL_NLTYPE_UNLABELED;
  	return 0;
  
  unlabel_getattr_nolabel:
  	rcu_read_unlock();

  	if (netlabel_unlabel_acceptflg == 0)
  		return -ENOMSG;

  	secattr->type = NETLBL_NLTYPE_UNLABELED;

  	return 0;

  }
  
  /**
   * netlbl_unlabel_defconf - Set the default config to allow unlabeled packets
   *
   * Description:
   * Set the default NetLabel configuration to allow incoming unlabeled packets
   * and to send unlabeled network traffic by default.
   *
   */

  int __init netlbl_unlabel_defconf(void)

  {
  	int ret_val;
  	struct netlbl_dom_map *entry;

  	struct netlbl_audit audit_info;

  	/* Only the kernel is allowed to call this function and the only time
  	 * it is called is at bootup before the audit subsystem is reporting
  	 * messages so don't worry to much about these values. */
  	security_task_getsecid(current, &audit_info.secid);
  	audit_info.loginuid = 0;

  	audit_info.sessionid = 0;

  
  	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  	if (entry == NULL)
  		return -ENOMEM;
  	entry->type = NETLBL_NLTYPE_UNLABELED;

  	ret_val = netlbl_domhsh_add_default(entry, &audit_info);

  	if (ret_val != 0)
  		return ret_val;

  	netlbl_unlabel_acceptflg_set(1, &audit_info);

  
  	return 0;
  }