/*
   * NetLabel Kernel API
   *
   * This file defines the kernel API 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@paul-moore.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/init.h>
  #include <linux/types.h>

  #include <linux/slab.h>

  #include <linux/audit.h>

  #include <linux/in.h>
  #include <linux/in6.h>

  #include <net/ip.h>

  #include <net/ipv6.h>

  #include <net/netlabel.h>
  #include <net/cipso_ipv4.h>
  #include <asm/bug.h>

  #include <linux/atomic.h>

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

  #include "netlabel_cipso_v4.h"

  #include "netlabel_user.h"

  #include "netlabel_mgmt.h"

  #include "netlabel_addrlist.h"

  
  /*

   * Configuration Functions
   */
  
  /**
   * netlbl_cfg_map_del - Remove a NetLabel/LSM domain mapping
   * @domain: the domain mapping to remove

   * @family: address family
   * @addr: IP address
   * @mask: IP address mask

   * @audit_info: NetLabel audit information
   *
   * Description:
   * Removes a NetLabel/LSM domain mapping.  A @domain value of NULL causes the
   * default domain mapping to be removed.  Returns zero on success, negative
   * values on failure.
   *
   */

  int netlbl_cfg_map_del(const char *domain,
  		       u16 family,
  		       const void *addr,
  		       const void *mask,
  		       struct netlbl_audit *audit_info)

  {

  	if (addr == NULL && mask == NULL) {
  		return netlbl_domhsh_remove(domain, audit_info);
  	} else if (addr != NULL && mask != NULL) {
  		switch (family) {
  		case AF_INET:
  			return netlbl_domhsh_remove_af4(domain, addr, mask,
  							audit_info);
  		default:
  			return -EPFNOSUPPORT;
  		}
  	} else
  		return -EINVAL;

  }
  
  /**

   * netlbl_cfg_unlbl_map_add - Add a new unlabeled mapping

   * @domain: the domain mapping to add

   * @family: address family
   * @addr: IP address
   * @mask: IP address mask

   * @audit_info: NetLabel audit information
   *
   * Description:
   * Adds a new unlabeled NetLabel/LSM domain mapping.  A @domain value of NULL
   * causes a new default domain mapping to be added.  Returns zero on success,
   * negative values on failure.
   *
   */

  int netlbl_cfg_unlbl_map_add(const char *domain,
  			     u16 family,
  			     const void *addr,
  			     const void *mask,

  			     struct netlbl_audit *audit_info)
  {
  	int ret_val = -ENOMEM;
  	struct netlbl_dom_map *entry;

  	struct netlbl_domaddr_map *addrmap = NULL;
  	struct netlbl_domaddr4_map *map4 = NULL;
  	struct netlbl_domaddr6_map *map6 = NULL;

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

  		return -ENOMEM;

  	if (domain != NULL) {
  		entry->domain = kstrdup(domain, GFP_ATOMIC);
  		if (entry->domain == NULL)

  			goto cfg_unlbl_map_add_failure;
  	}
  
  	if (addr == NULL && mask == NULL)
  		entry->type = NETLBL_NLTYPE_UNLABELED;
  	else if (addr != NULL && mask != NULL) {
  		addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
  		if (addrmap == NULL)
  			goto cfg_unlbl_map_add_failure;
  		INIT_LIST_HEAD(&addrmap->list4);
  		INIT_LIST_HEAD(&addrmap->list6);
  
  		switch (family) {

  		case AF_INET: {
  			const struct in_addr *addr4 = addr;
  			const struct in_addr *mask4 = mask;

  			map4 = kzalloc(sizeof(*map4), GFP_ATOMIC);
  			if (map4 == NULL)
  				goto cfg_unlbl_map_add_failure;
  			map4->type = NETLBL_NLTYPE_UNLABELED;
  			map4->list.addr = addr4->s_addr & mask4->s_addr;
  			map4->list.mask = mask4->s_addr;
  			map4->list.valid = 1;
  			ret_val = netlbl_af4list_add(&map4->list,
  						     &addrmap->list4);
  			if (ret_val != 0)
  				goto cfg_unlbl_map_add_failure;
  			break;

  			}

  #if IS_ENABLED(CONFIG_IPV6)

  		case AF_INET6: {
  			const struct in6_addr *addr6 = addr;
  			const struct in6_addr *mask6 = mask;

  			map6 = kzalloc(sizeof(*map6), GFP_ATOMIC);

  			if (map6 == NULL)

  				goto cfg_unlbl_map_add_failure;
  			map6->type = NETLBL_NLTYPE_UNLABELED;

  			map6->list.addr = *addr6;

  			map6->list.addr.s6_addr32[0] &= mask6->s6_addr32[0];
  			map6->list.addr.s6_addr32[1] &= mask6->s6_addr32[1];
  			map6->list.addr.s6_addr32[2] &= mask6->s6_addr32[2];
  			map6->list.addr.s6_addr32[3] &= mask6->s6_addr32[3];

  			map6->list.mask = *mask6;

  			map6->list.valid = 1;

  			ret_val = netlbl_af6list_add(&map6->list,
  						     &addrmap->list6);

  			if (ret_val != 0)
  				goto cfg_unlbl_map_add_failure;
  			break;

  			}
  #endif /* IPv6 */

  		default:
  			goto cfg_unlbl_map_add_failure;
  			break;
  		}
  
  		entry->type_def.addrsel = addrmap;
  		entry->type = NETLBL_NLTYPE_ADDRSELECT;
  	} else {
  		ret_val = -EINVAL;
  		goto cfg_unlbl_map_add_failure;

  	}

  
  	ret_val = netlbl_domhsh_add(entry, audit_info);
  	if (ret_val != 0)

  		goto cfg_unlbl_map_add_failure;

  
  	return 0;

  cfg_unlbl_map_add_failure:

  	kfree(entry->domain);

  	kfree(entry);

  	kfree(addrmap);
  	kfree(map4);
  	kfree(map6);

  	return ret_val;
  }

  
  /**
   * netlbl_cfg_unlbl_static_add - Adds a new static label
   * @net: network namespace
   * @dev_name: interface name
   * @addr: IP address in network byte order (struct in[6]_addr)
   * @mask: address mask in network byte order (struct in[6]_addr)
   * @family: address family
   * @secid: LSM secid value for the entry
   * @audit_info: NetLabel audit information
   *
   * Description:
   * Adds a new NetLabel static label to be used when protocol provided labels
   * are not present on incoming traffic.  If @dev_name is NULL then the default
   * interface will be used.  Returns zero on success, negative values on failure.
   *
   */
  int netlbl_cfg_unlbl_static_add(struct net *net,
  				const char *dev_name,
  				const void *addr,
  				const void *mask,
  				u16 family,
  				u32 secid,
  				struct netlbl_audit *audit_info)
  {
  	u32 addr_len;
  
  	switch (family) {
  	case AF_INET:
  		addr_len = sizeof(struct in_addr);
  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		addr_len = sizeof(struct in6_addr);
  		break;

  #endif /* IPv6 */

  	default:
  		return -EPFNOSUPPORT;
  	}
  
  	return netlbl_unlhsh_add(net,
  				 dev_name, addr, mask, addr_len,
  				 secid, audit_info);
  }
  
  /**
   * netlbl_cfg_unlbl_static_del - Removes an existing static label
   * @net: network namespace
   * @dev_name: interface name
   * @addr: IP address in network byte order (struct in[6]_addr)
   * @mask: address mask in network byte order (struct in[6]_addr)
   * @family: address family
   * @secid: LSM secid value for the entry
   * @audit_info: NetLabel audit information
   *
   * Description:
   * Removes an existing NetLabel static label used when protocol provided labels
   * are not present on incoming traffic.  If @dev_name is NULL then the default
   * interface will be used.  Returns zero on success, negative values on failure.
   *
   */
  int netlbl_cfg_unlbl_static_del(struct net *net,
  				const char *dev_name,
  				const void *addr,
  				const void *mask,
  				u16 family,
  				struct netlbl_audit *audit_info)
  {
  	u32 addr_len;
  
  	switch (family) {
  	case AF_INET:
  		addr_len = sizeof(struct in_addr);
  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		addr_len = sizeof(struct in6_addr);
  		break;

  #endif /* IPv6 */

  	default:
  		return -EPFNOSUPPORT;
  	}
  
  	return netlbl_unlhsh_remove(net,
  				    dev_name, addr, mask, addr_len,
  				    audit_info);
  }
  
  /**
   * netlbl_cfg_cipsov4_add - Add a new CIPSOv4 DOI definition
   * @doi_def: CIPSO DOI definition
   * @audit_info: NetLabel audit information
   *
   * Description:
   * Add a new CIPSO DOI definition as defined by @doi_def.  Returns zero on
   * success and negative values on failure.
   *
   */
  int netlbl_cfg_cipsov4_add(struct cipso_v4_doi *doi_def,
  			   struct netlbl_audit *audit_info)
  {
  	return cipso_v4_doi_add(doi_def, audit_info);
  }
  
  /**
   * netlbl_cfg_cipsov4_del - Remove an existing CIPSOv4 DOI definition
   * @doi: CIPSO DOI
   * @audit_info: NetLabel audit information
   *
   * Description:
   * Remove an existing CIPSO DOI definition matching @doi.  Returns zero on
   * success and negative values on failure.
   *
   */
  void netlbl_cfg_cipsov4_del(u32 doi, struct netlbl_audit *audit_info)
  {
  	cipso_v4_doi_remove(doi, audit_info);
  }

  /**

   * netlbl_cfg_cipsov4_map_add - Add a new CIPSOv4 DOI mapping
   * @doi: the CIPSO DOI

   * @domain: the domain mapping to add

   * @addr: IP address
   * @mask: IP address mask

   * @audit_info: NetLabel audit information
   *
   * Description:

   * Add a new NetLabel/LSM domain mapping for the given CIPSO DOI to the NetLabel
   * subsystem.  A @domain value of NULL adds a new default domain mapping.
   * Returns zero on success, negative values on failure.

   *
   */

  int netlbl_cfg_cipsov4_map_add(u32 doi,

  			       const char *domain,

  			       const struct in_addr *addr,
  			       const struct in_addr *mask,

  			       struct netlbl_audit *audit_info)
  {
  	int ret_val = -ENOMEM;

  	struct cipso_v4_doi *doi_def;

  	struct netlbl_dom_map *entry;

  	struct netlbl_domaddr_map *addrmap = NULL;
  	struct netlbl_domaddr4_map *addrinfo = NULL;

  	doi_def = cipso_v4_doi_getdef(doi);
  	if (doi_def == NULL)
  		return -ENOENT;

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

  		goto out_entry;

  	if (domain != NULL) {
  		entry->domain = kstrdup(domain, GFP_ATOMIC);
  		if (entry->domain == NULL)

  			goto out_domain;

  	}

  	if (addr == NULL && mask == NULL) {
  		entry->type_def.cipsov4 = doi_def;
  		entry->type = NETLBL_NLTYPE_CIPSOV4;
  	} else if (addr != NULL && mask != NULL) {
  		addrmap = kzalloc(sizeof(*addrmap), GFP_ATOMIC);
  		if (addrmap == NULL)

  			goto out_addrmap;

  		INIT_LIST_HEAD(&addrmap->list4);
  		INIT_LIST_HEAD(&addrmap->list6);
  
  		addrinfo = kzalloc(sizeof(*addrinfo), GFP_ATOMIC);
  		if (addrinfo == NULL)

  			goto out_addrinfo;

  		addrinfo->type_def.cipsov4 = doi_def;
  		addrinfo->type = NETLBL_NLTYPE_CIPSOV4;
  		addrinfo->list.addr = addr->s_addr & mask->s_addr;
  		addrinfo->list.mask = mask->s_addr;
  		addrinfo->list.valid = 1;
  		ret_val = netlbl_af4list_add(&addrinfo->list, &addrmap->list4);
  		if (ret_val != 0)
  			goto cfg_cipsov4_map_add_failure;
  
  		entry->type_def.addrsel = addrmap;
  		entry->type = NETLBL_NLTYPE_ADDRSELECT;
  	} else {
  		ret_val = -EINVAL;

  		goto out_addrmap;

  	}

  	ret_val = netlbl_domhsh_add(entry, audit_info);
  	if (ret_val != 0)

  		goto cfg_cipsov4_map_add_failure;

  	return 0;

  cfg_cipsov4_map_add_failure:

  	kfree(addrinfo);
  out_addrinfo:
  	kfree(addrmap);
  out_addrmap:

  	kfree(entry->domain);

  out_domain:

  	kfree(entry);

  out_entry:
  	cipso_v4_doi_putdef(doi_def);

  	return ret_val;

  }

  /*

   * Security Attribute Functions
   */
  
  /**
   * netlbl_secattr_catmap_walk - Walk a LSM secattr catmap looking for a bit
   * @catmap: the category bitmap
   * @offset: the offset to start searching at, in bits
   *
   * Description:
   * This function walks a LSM secattr category bitmap starting at @offset and
   * returns the spot of the first set bit or -ENOENT if no bits are set.
   *
   */
  int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
  			       u32 offset)
  {
  	struct netlbl_lsm_secattr_catmap *iter = catmap;
  	u32 node_idx;
  	u32 node_bit;
  	NETLBL_CATMAP_MAPTYPE bitmap;
  
  	if (offset > iter->startbit) {
  		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
  			iter = iter->next;
  			if (iter == NULL)
  				return -ENOENT;
  		}
  		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
  		node_bit = offset - iter->startbit -
  			   (NETLBL_CATMAP_MAPSIZE * node_idx);
  	} else {
  		node_idx = 0;
  		node_bit = 0;
  	}
  	bitmap = iter->bitmap[node_idx] >> node_bit;
  
  	for (;;) {
  		if (bitmap != 0) {
  			while ((bitmap & NETLBL_CATMAP_BIT) == 0) {
  				bitmap >>= 1;
  				node_bit++;
  			}
  			return iter->startbit +
  				(NETLBL_CATMAP_MAPSIZE * node_idx) + node_bit;
  		}
  		if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
  			if (iter->next != NULL) {
  				iter = iter->next;
  				node_idx = 0;
  			} else
  				return -ENOENT;
  		}
  		bitmap = iter->bitmap[node_idx];
  		node_bit = 0;
  	}
  
  	return -ENOENT;
  }
  
  /**
   * netlbl_secattr_catmap_walk_rng - Find the end of a string of set bits
   * @catmap: the category bitmap
   * @offset: the offset to start searching at, in bits
   *
   * Description:
   * This function walks a LSM secattr category bitmap starting at @offset and
   * returns the spot of the first cleared bit or -ENOENT if the offset is past
   * the end of the bitmap.
   *
   */
  int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
  				   u32 offset)
  {
  	struct netlbl_lsm_secattr_catmap *iter = catmap;
  	u32 node_idx;
  	u32 node_bit;
  	NETLBL_CATMAP_MAPTYPE bitmask;
  	NETLBL_CATMAP_MAPTYPE bitmap;
  
  	if (offset > iter->startbit) {
  		while (offset >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
  			iter = iter->next;
  			if (iter == NULL)
  				return -ENOENT;
  		}
  		node_idx = (offset - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
  		node_bit = offset - iter->startbit -
  			   (NETLBL_CATMAP_MAPSIZE * node_idx);
  	} else {
  		node_idx = 0;
  		node_bit = 0;
  	}
  	bitmask = NETLBL_CATMAP_BIT << node_bit;
  
  	for (;;) {
  		bitmap = iter->bitmap[node_idx];
  		while (bitmask != 0 && (bitmap & bitmask) != 0) {
  			bitmask <<= 1;
  			node_bit++;
  		}
  
  		if (bitmask != 0)
  			return iter->startbit +
  				(NETLBL_CATMAP_MAPSIZE * node_idx) +
  				node_bit - 1;
  		else if (++node_idx >= NETLBL_CATMAP_MAPCNT) {
  			if (iter->next == NULL)
  				return iter->startbit +	NETLBL_CATMAP_SIZE - 1;
  			iter = iter->next;
  			node_idx = 0;
  		}
  		bitmask = NETLBL_CATMAP_BIT;
  		node_bit = 0;
  	}
  
  	return -ENOENT;
  }
  
  /**
   * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
   * @catmap: the category bitmap
   * @bit: the bit to set
   * @flags: memory allocation flags
   *
   * Description:
   * Set the bit specified by @bit in @catmap.  Returns zero on success,
   * negative values on failure.
   *
   */
  int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
  				 u32 bit,
  				 gfp_t flags)
  {
  	struct netlbl_lsm_secattr_catmap *iter = catmap;
  	u32 node_bit;
  	u32 node_idx;
  
  	while (iter->next != NULL &&
  	       bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
  		iter = iter->next;
  	if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
  		iter->next = netlbl_secattr_catmap_alloc(flags);
  		if (iter->next == NULL)
  			return -ENOMEM;
  		iter = iter->next;
  		iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
  	}
  
  	/* gcc always rounds to zero when doing integer division */
  	node_idx = (bit - iter->startbit) / NETLBL_CATMAP_MAPSIZE;
  	node_bit = bit - iter->startbit - (NETLBL_CATMAP_MAPSIZE * node_idx);
  	iter->bitmap[node_idx] |= NETLBL_CATMAP_BIT << node_bit;
  
  	return 0;
  }
  
  /**
   * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
   * @catmap: the category bitmap
   * @start: the starting bit
   * @end: the last bit in the string
   * @flags: memory allocation flags
   *
   * Description:
   * Set a range of bits, starting at @start and ending with @end.  Returns zero
   * on success, negative values on failure.
   *
   */
  int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
  				 u32 start,
  				 u32 end,
  				 gfp_t flags)
  {
  	int ret_val = 0;
  	struct netlbl_lsm_secattr_catmap *iter = catmap;
  	u32 iter_max_spot;
  	u32 spot;
  
  	/* XXX - This could probably be made a bit faster by combining writes
  	 * to the catmap instead of setting a single bit each time, but for
  	 * right now skipping to the start of the range in the catmap should
  	 * be a nice improvement over calling the individual setbit function
  	 * repeatedly from a loop. */
  
  	while (iter->next != NULL &&
  	       start >= (iter->startbit + NETLBL_CATMAP_SIZE))
  		iter = iter->next;
  	iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
  
  	for (spot = start; spot <= end && ret_val == 0; spot++) {
  		if (spot >= iter_max_spot && iter->next != NULL) {
  			iter = iter->next;
  			iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
  		}

  		ret_val = netlbl_secattr_catmap_setbit(iter, spot, flags);

  	}
  
  	return ret_val;
  }
  
  /*

   * LSM Functions
   */
  
  /**

   * netlbl_enabled - Determine if the NetLabel subsystem is enabled
   *
   * Description:
   * The LSM can use this function to determine if it should use NetLabel
   * security attributes in it's enforcement mechanism.  Currently, NetLabel is
   * considered to be enabled when it's configuration contains a valid setup for
   * at least one labeled protocol (i.e. NetLabel can understand incoming
   * labeled packets of at least one type); otherwise NetLabel is considered to
   * be disabled.
   *
   */
  int netlbl_enabled(void)
  {
  	/* At some point we probably want to expose this mechanism to the user
  	 * as well so that admins can toggle NetLabel regardless of the
  	 * configuration */

  	return (atomic_read(&netlabel_mgmt_protocount) > 0);

  }
  
  /**

   * netlbl_sock_setattr - Label a socket using the correct protocol

   * @sk: the socket to label

   * @family: protocol family

   * @secattr: the security attributes
   *
   * Description:
   * Attach the correct label to the given socket using the security attributes

   * specified in @secattr.  This function requires exclusive access to @sk,
   * which means it either needs to be in the process of being created or locked.

   * Returns zero on success, -EDESTADDRREQ if the domain is configured to use
   * network address selectors (can't blindly label the socket), and negative
   * values on all other failures.

   *
   */

  int netlbl_sock_setattr(struct sock *sk,

  			u16 family,

  			const struct netlbl_lsm_secattr *secattr)

  {

  	int ret_val;

  	struct netlbl_dom_map *dom_entry;
  
  	rcu_read_lock();
  	dom_entry = netlbl_domhsh_getentry(secattr->domain);

  	if (dom_entry == NULL) {
  		ret_val = -ENOENT;

  		goto socket_setattr_return;

  	}
  	switch (family) {
  	case AF_INET:
  		switch (dom_entry->type) {
  		case NETLBL_NLTYPE_ADDRSELECT:
  			ret_val = -EDESTADDRREQ;
  			break;
  		case NETLBL_NLTYPE_CIPSOV4:
  			ret_val = cipso_v4_sock_setattr(sk,
  						    dom_entry->type_def.cipsov4,
  						    secattr);
  			break;
  		case NETLBL_NLTYPE_UNLABELED:
  			ret_val = 0;
  			break;
  		default:
  			ret_val = -ENOENT;
  		}

  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		/* since we don't support any IPv6 labeling protocols right
  		 * now we can optimize everything away until we do */

  		ret_val = 0;
  		break;

  #endif /* IPv6 */

  	default:

  		ret_val = -EPROTONOSUPPORT;

  	}
  
  socket_setattr_return:
  	rcu_read_unlock();
  	return ret_val;
  }
  
  /**

   * netlbl_sock_delattr - Delete all the NetLabel labels on a socket
   * @sk: the socket
   *
   * Description:
   * Remove all the NetLabel labeling from @sk.  The caller is responsible for
   * ensuring that @sk is locked.
   *
   */
  void netlbl_sock_delattr(struct sock *sk)
  {
  	cipso_v4_sock_delattr(sk);
  }
  
  /**

   * netlbl_sock_getattr - Determine the security attributes of a sock
   * @sk: the sock
   * @secattr: the security attributes
   *
   * Description:

   * Examines the given sock to see if any NetLabel style labeling has been

   * applied to the sock, if so it parses the socket label and returns the
   * security attributes in @secattr.  Returns zero on success, negative values
   * on failure.
   *
   */

  int netlbl_sock_getattr(struct sock *sk,
  			struct netlbl_lsm_secattr *secattr)

  {

  	int ret_val;
  
  	switch (sk->sk_family) {
  	case AF_INET:
  		ret_val = cipso_v4_sock_getattr(sk, secattr);
  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		ret_val = -ENOMSG;
  		break;
  #endif /* IPv6 */
  	default:
  		ret_val = -EPROTONOSUPPORT;
  	}
  
  	return ret_val;

  }
  
  /**

   * netlbl_conn_setattr - Label a connected socket using the correct protocol
   * @sk: the socket to label
   * @addr: the destination address
   * @secattr: the security attributes
   *
   * Description:
   * Attach the correct label to the given connected socket using the security
   * attributes specified in @secattr.  The caller is responsible for ensuring
   * that @sk is locked.  Returns zero on success, negative values on failure.
   *
   */
  int netlbl_conn_setattr(struct sock *sk,
  			struct sockaddr *addr,
  			const struct netlbl_lsm_secattr *secattr)
  {
  	int ret_val;
  	struct sockaddr_in *addr4;
  	struct netlbl_domaddr4_map *af4_entry;
  
  	rcu_read_lock();
  	switch (addr->sa_family) {
  	case AF_INET:
  		addr4 = (struct sockaddr_in *)addr;
  		af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
  						       addr4->sin_addr.s_addr);
  		if (af4_entry == NULL) {
  			ret_val = -ENOENT;
  			goto conn_setattr_return;
  		}
  		switch (af4_entry->type) {
  		case NETLBL_NLTYPE_CIPSOV4:
  			ret_val = cipso_v4_sock_setattr(sk,
  						   af4_entry->type_def.cipsov4,
  						   secattr);
  			break;
  		case NETLBL_NLTYPE_UNLABELED:
  			/* just delete the protocols we support for right now
  			 * but we could remove other protocols if needed */
  			cipso_v4_sock_delattr(sk);
  			ret_val = 0;
  			break;
  		default:
  			ret_val = -ENOENT;
  		}
  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		/* since we don't support any IPv6 labeling protocols right
  		 * now we can optimize everything away until we do */
  		ret_val = 0;
  		break;
  #endif /* IPv6 */
  	default:

  		ret_val = -EPROTONOSUPPORT;

  	}
  
  conn_setattr_return:
  	rcu_read_unlock();
  	return ret_val;
  }
  
  /**

   * netlbl_req_setattr - Label a request socket using the correct protocol
   * @req: the request socket to label
   * @secattr: the security attributes
   *
   * Description:
   * Attach the correct label to the given socket using the security attributes
   * specified in @secattr.  Returns zero on success, negative values on failure.
   *
   */
  int netlbl_req_setattr(struct request_sock *req,
  		       const struct netlbl_lsm_secattr *secattr)
  {
  	int ret_val;
  	struct netlbl_dom_map *dom_entry;
  	struct netlbl_domaddr4_map *af4_entry;
  	u32 proto_type;
  	struct cipso_v4_doi *proto_cv4;
  
  	rcu_read_lock();
  	dom_entry = netlbl_domhsh_getentry(secattr->domain);
  	if (dom_entry == NULL) {
  		ret_val = -ENOENT;
  		goto req_setattr_return;
  	}
  	switch (req->rsk_ops->family) {
  	case AF_INET:
  		if (dom_entry->type == NETLBL_NLTYPE_ADDRSELECT) {
  			struct inet_request_sock *req_inet = inet_rsk(req);
  			af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
  							    req_inet->rmt_addr);
  			if (af4_entry == NULL) {
  				ret_val = -ENOENT;
  				goto req_setattr_return;
  			}
  			proto_type = af4_entry->type;
  			proto_cv4 = af4_entry->type_def.cipsov4;
  		} else {
  			proto_type = dom_entry->type;
  			proto_cv4 = dom_entry->type_def.cipsov4;
  		}
  		switch (proto_type) {
  		case NETLBL_NLTYPE_CIPSOV4:
  			ret_val = cipso_v4_req_setattr(req, proto_cv4, secattr);
  			break;
  		case NETLBL_NLTYPE_UNLABELED:
  			/* just delete the protocols we support for right now
  			 * but we could remove other protocols if needed */
  			cipso_v4_req_delattr(req);
  			ret_val = 0;
  			break;
  		default:
  			ret_val = -ENOENT;
  		}
  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		/* since we don't support any IPv6 labeling protocols right
  		 * now we can optimize everything away until we do */
  		ret_val = 0;
  		break;
  #endif /* IPv6 */
  	default:
  		ret_val = -EPROTONOSUPPORT;
  	}
  
  req_setattr_return:
  	rcu_read_unlock();
  	return ret_val;
  }
  
  /**

  * netlbl_req_delattr - Delete all the NetLabel labels on a socket
  * @req: the socket
  *
  * Description:
  * Remove all the NetLabel labeling from @req.
  *
  */
  void netlbl_req_delattr(struct request_sock *req)
  {
  	cipso_v4_req_delattr(req);
  }
  
  /**

   * netlbl_skbuff_setattr - Label a packet using the correct protocol
   * @skb: the packet
   * @family: protocol family
   * @secattr: the security attributes
   *
   * Description:
   * Attach the correct label to the given packet using the security attributes
   * specified in @secattr.  Returns zero on success, negative values on failure.
   *
   */
  int netlbl_skbuff_setattr(struct sk_buff *skb,
  			  u16 family,
  			  const struct netlbl_lsm_secattr *secattr)
  {
  	int ret_val;
  	struct iphdr *hdr4;
  	struct netlbl_domaddr4_map *af4_entry;
  
  	rcu_read_lock();
  	switch (family) {
  	case AF_INET:
  		hdr4 = ip_hdr(skb);
  		af4_entry = netlbl_domhsh_getentry_af4(secattr->domain,
  						       hdr4->daddr);
  		if (af4_entry == NULL) {
  			ret_val = -ENOENT;
  			goto skbuff_setattr_return;
  		}
  		switch (af4_entry->type) {
  		case NETLBL_NLTYPE_CIPSOV4:
  			ret_val = cipso_v4_skbuff_setattr(skb,
  						   af4_entry->type_def.cipsov4,
  						   secattr);
  			break;
  		case NETLBL_NLTYPE_UNLABELED:
  			/* just delete the protocols we support for right now
  			 * but we could remove other protocols if needed */
  			ret_val = cipso_v4_skbuff_delattr(skb);
  			break;
  		default:
  			ret_val = -ENOENT;
  		}
  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		/* since we don't support any IPv6 labeling protocols right
  		 * now we can optimize everything away until we do */
  		ret_val = 0;
  		break;
  #endif /* IPv6 */
  	default:

  		ret_val = -EPROTONOSUPPORT;

  	}
  
  skbuff_setattr_return:
  	rcu_read_unlock();
  	return ret_val;
  }
  
  /**

   * netlbl_skbuff_getattr - Determine the security attributes of a packet
   * @skb: the packet

   * @family: protocol family

   * @secattr: the security attributes
   *
   * Description:
   * Examines the given packet to see if a recognized form of packet labeling
   * is present, if so it parses the packet label and returns the security
   * attributes in @secattr.  Returns zero on success, negative values on
   * failure.
   *
   */
  int netlbl_skbuff_getattr(const struct sk_buff *skb,

  			  u16 family,

  			  struct netlbl_lsm_secattr *secattr)
  {

  	switch (family) {
  	case AF_INET:
  		if (CIPSO_V4_OPTEXIST(skb) &&
  		    cipso_v4_skbuff_getattr(skb, secattr) == 0)
  			return 0;
  		break;

  #if IS_ENABLED(CONFIG_IPV6)

  	case AF_INET6:
  		break;
  #endif /* IPv6 */
  	}

  	return netlbl_unlabel_getattr(skb, family, secattr);

  }
  
  /**
   * netlbl_skbuff_err - Handle a LSM error on a sk_buff
   * @skb: the packet
   * @error: the error code

   * @gateway: true if host is acting as a gateway, false otherwise

   *
   * Description:
   * Deal with a LSM problem when handling the packet in @skb, typically this is
   * a permission denied problem (-EACCES).  The correct action is determined
   * according to the packet's labeling protocol.
   *
   */

  void netlbl_skbuff_err(struct sk_buff *skb, int error, int gateway)

  {
  	if (CIPSO_V4_OPTEXIST(skb))

  		cipso_v4_error(skb, error, gateway);

  }
  
  /**
   * netlbl_cache_invalidate - Invalidate all of the NetLabel protocol caches
   *
   * Description:
   * For all of the NetLabel protocols that support some form of label mapping
   * cache, invalidate the cache.  Returns zero on success, negative values on
   * error.
   *
   */
  void netlbl_cache_invalidate(void)
  {
  	cipso_v4_cache_invalidate();
  }
  
  /**
   * netlbl_cache_add - Add an entry to a NetLabel protocol cache
   * @skb: the packet
   * @secattr: the packet's security attributes
   *
   * Description:
   * Add the LSM security attributes for the given packet to the underlying
   * NetLabel protocol's label mapping cache.  Returns zero on success, negative
   * values on error.
   *
   */
  int netlbl_cache_add(const struct sk_buff *skb,
  		     const struct netlbl_lsm_secattr *secattr)
  {

  	if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)

  		return -ENOMSG;
  
  	if (CIPSO_V4_OPTEXIST(skb))
  		return cipso_v4_cache_add(skb, secattr);
  
  	return -ENOMSG;
  }
  
  /*

   * Protocol Engine Functions
   */
  
  /**
   * netlbl_audit_start - Start an audit message
   * @type: audit message type
   * @audit_info: NetLabel audit information
   *
   * Description:
   * Start an audit message using the type specified in @type and fill the audit
   * message with some fields common to all NetLabel audit messages.  This
   * function should only be used by protocol engines, not LSMs.  Returns a
   * pointer to the audit buffer on success, NULL on failure.
   *
   */
  struct audit_buffer *netlbl_audit_start(int type,
  					struct netlbl_audit *audit_info)
  {
  	return netlbl_audit_start_common(type, audit_info);
  }
  
  /*

   * Setup Functions
   */
  
  /**
   * netlbl_init - Initialize NetLabel
   *
   * Description:
   * Perform the required NetLabel initialization before first use.
   *
   */
  static int __init netlbl_init(void)
  {
  	int ret_val;
  
  	printk(KERN_INFO "NetLabel: Initializing
  ");
  	printk(KERN_INFO "NetLabel:  domain hash size = %u
  ",
  	       (1 << NETLBL_DOMHSH_BITSIZE));
  	printk(KERN_INFO "NetLabel:  protocols ="
  	       " UNLABELED"
  	       " CIPSOv4"
  	       "
  ");
  
  	ret_val = netlbl_domhsh_init(NETLBL_DOMHSH_BITSIZE);
  	if (ret_val != 0)
  		goto init_failure;

  	ret_val = netlbl_unlabel_init(NETLBL_UNLHSH_BITSIZE);
  	if (ret_val != 0)
  		goto init_failure;

  	ret_val = netlbl_netlink_init();
  	if (ret_val != 0)
  		goto init_failure;
  
  	ret_val = netlbl_unlabel_defconf();
  	if (ret_val != 0)
  		goto init_failure;
  	printk(KERN_INFO "NetLabel:  unlabeled traffic allowed by default
  ");
  
  	return 0;
  
  init_failure:
  	panic("NetLabel: failed to initialize properly (%d)
  ", ret_val);
  }
  
  subsys_initcall(netlbl_init);