File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c
new file mode 100644
index 0000000..f0cb92f
--- /dev/null
+++ b/net/netlabel/netlabel_domainhash.c
@@ -0,0 +1,790 @@
+/*
+ * NetLabel Domain Hash Table
+ *
+ * This file manages the domain hash table that NetLabel uses to determine
+ * which network labeling protocol to use for a given domain.  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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/rculist.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/audit.h>
+#include <linux/slab.h>
+#include <net/netlabel.h>
+#include <net/cipso_ipv4.h>
+#include <asm/bug.h>
+
+#include "netlabel_mgmt.h"
+#include "netlabel_addrlist.h"
+#include "netlabel_domainhash.h"
+#include "netlabel_user.h"
+
+struct netlbl_domhsh_tbl {
+	struct list_head *tbl;
+	u32 size;
+};
+
+/* Domain hash table */
+/* updates should be so rare that having one spinlock for the entire hash table
+ * should be okay */
+static DEFINE_SPINLOCK(netlbl_domhsh_lock);
+#define netlbl_domhsh_rcu_deref(p) \
+	rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
+static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
+static struct netlbl_dom_map *netlbl_domhsh_def = NULL;
+
+/*
+ * Domain Hash Table Helper Functions
+ */
+
+/**
+ * netlbl_domhsh_free_entry - Frees a domain hash table entry
+ * @entry: the entry's RCU field
+ *
+ * Description:
+ * This function is designed to be used as a callback to the call_rcu()
+ * function so that the memory allocated to a hash table entry can be released
+ * safely.
+ *
+ */
+static void netlbl_domhsh_free_entry(struct rcu_head *entry)
+{
+	struct netlbl_dom_map *ptr;
+	struct netlbl_af4list *iter4;
+	struct netlbl_af4list *tmp4;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct netlbl_af6list *iter6;
+	struct netlbl_af6list *tmp6;
+#endif /* IPv6 */
+
+	ptr = container_of(entry, struct netlbl_dom_map, rcu);
+	if (ptr->def.type == NETLBL_NLTYPE_ADDRSELECT) {
+		netlbl_af4list_foreach_safe(iter4, tmp4,
+					    &ptr->def.addrsel->list4) {
+			netlbl_af4list_remove_entry(iter4);
+			kfree(netlbl_domhsh_addr4_entry(iter4));
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		netlbl_af6list_foreach_safe(iter6, tmp6,
+					    &ptr->def.addrsel->list6) {
+			netlbl_af6list_remove_entry(iter6);
+			kfree(netlbl_domhsh_addr6_entry(iter6));
+		}
+#endif /* IPv6 */
+	}
+	kfree(ptr->domain);
+	kfree(ptr);
+}
+
+/**
+ * netlbl_domhsh_hash - Hashing function for the domain hash table
+ * @domain: the domain name to hash
+ *
+ * Description:
+ * This is the hashing function for the domain hash table, it returns the
+ * correct bucket number for the domain.  The caller is responsible for
+ * ensuring that the hash table is protected with either a RCU read lock or the
+ * hash table lock.
+ *
+ */
+static u32 netlbl_domhsh_hash(const char *key)
+{
+	u32 iter;
+	u32 val;
+	u32 len;
+
+	/* This is taken (with slight modification) from
+	 * security/selinux/ss/symtab.c:symhash() */
+
+	for (iter = 0, val = 0, len = strlen(key); iter < len; iter++)
+		val = (val << 4 | (val >> (8 * sizeof(u32) - 4))) ^ key[iter];
+	return val & (netlbl_domhsh_rcu_deref(netlbl_domhsh)->size - 1);
+}
+
+/**
+ * netlbl_domhsh_search - Search for a domain entry
+ * @domain: the domain
+ *
+ * Description:
+ * Searches the domain hash table and returns a pointer to the hash table
+ * entry if found, otherwise NULL is returned.  The caller is responsible for
+ * ensuring that the hash table is protected with either a RCU read lock or the
+ * hash table lock.
+ *
+ */
+static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain)
+{
+	u32 bkt;
+	struct list_head *bkt_list;
+	struct netlbl_dom_map *iter;
+
+	if (domain != NULL) {
+		bkt = netlbl_domhsh_hash(domain);
+		bkt_list = &netlbl_domhsh_rcu_deref(netlbl_domhsh)->tbl[bkt];
+		list_for_each_entry_rcu(iter, bkt_list, list)
+			if (iter->valid && strcmp(iter->domain, domain) == 0)
+				return iter;
+	}
+
+	return NULL;
+}
+
+/**
+ * netlbl_domhsh_search_def - Search for a domain entry
+ * @domain: the domain
+ * @def: return default if no match is found
+ *
+ * Description:
+ * Searches the domain hash table and returns a pointer to the hash table
+ * entry if an exact match is found, if an exact match is not present in the
+ * hash table then the default entry is returned if valid otherwise NULL is
+ * returned.  The caller is responsible ensuring that the hash table is
+ * protected with either a RCU read lock or the hash table lock.
+ *
+ */
+static struct netlbl_dom_map *netlbl_domhsh_search_def(const char *domain)
+{
+	struct netlbl_dom_map *entry;
+
+	entry = netlbl_domhsh_search(domain);
+	if (entry == NULL) {
+		entry = netlbl_domhsh_rcu_deref(netlbl_domhsh_def);
+		if (entry != NULL && !entry->valid)
+			entry = NULL;
+	}
+
+	return entry;
+}
+
+/**
+ * netlbl_domhsh_audit_add - Generate an audit entry for an add event
+ * @entry: the entry being added
+ * @addr4: the IPv4 address information
+ * @addr6: the IPv6 address information
+ * @result: the result code
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Generate an audit record for adding a new NetLabel/LSM mapping entry with
+ * the given information.  Caller is responsible for holding the necessary
+ * locks.
+ *
+ */
+static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry,
+				    struct netlbl_af4list *addr4,
+				    struct netlbl_af6list *addr6,
+				    int result,
+				    struct netlbl_audit *audit_info)
+{
+	struct audit_buffer *audit_buf;
+	struct cipso_v4_doi *cipsov4 = NULL;
+	u32 type;
+
+	audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
+	if (audit_buf != NULL) {
+		audit_log_format(audit_buf, " nlbl_domain=%s",
+				 entry->domain ? entry->domain : "(default)");
+		if (addr4 != NULL) {
+			struct netlbl_domaddr4_map *map4;
+			map4 = netlbl_domhsh_addr4_entry(addr4);
+			type = map4->def.type;
+			cipsov4 = map4->def.cipso;
+			netlbl_af4list_audit_addr(audit_buf, 0, NULL,
+						  addr4->addr, addr4->mask);
+#if IS_ENABLED(CONFIG_IPV6)
+		} else if (addr6 != NULL) {
+			struct netlbl_domaddr6_map *map6;
+			map6 = netlbl_domhsh_addr6_entry(addr6);
+			type = map6->def.type;
+			netlbl_af6list_audit_addr(audit_buf, 0, NULL,
+						  &addr6->addr, &addr6->mask);
+#endif /* IPv6 */
+		} else {
+			type = entry->def.type;
+			cipsov4 = entry->def.cipso;
+		}
+		switch (type) {
+		case NETLBL_NLTYPE_UNLABELED:
+			audit_log_format(audit_buf, " nlbl_protocol=unlbl");
+			break;
+		case NETLBL_NLTYPE_CIPSOV4:
+			BUG_ON(cipsov4 == NULL);
+			audit_log_format(audit_buf,
+					 " nlbl_protocol=cipsov4 cipso_doi=%u",
+					 cipsov4->doi);
+			break;
+		}
+		audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0);
+		audit_log_end(audit_buf);
+	}
+}
+
+/**
+ * netlbl_domhsh_validate - Validate a new domain mapping entry
+ * @entry: the entry to validate
+ *
+ * This function validates the new domain mapping entry to ensure that it is
+ * a valid entry.  Returns zero on success, negative values on failure.
+ *
+ */
+static int netlbl_domhsh_validate(const struct netlbl_dom_map *entry)
+{
+	struct netlbl_af4list *iter4;
+	struct netlbl_domaddr4_map *map4;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct netlbl_af6list *iter6;
+	struct netlbl_domaddr6_map *map6;
+#endif /* IPv6 */
+
+	if (entry == NULL)
+		return -EINVAL;
+
+	switch (entry->def.type) {
+	case NETLBL_NLTYPE_UNLABELED:
+		if (entry->def.cipso != NULL || entry->def.addrsel != NULL)
+			return -EINVAL;
+		break;
+	case NETLBL_NLTYPE_CIPSOV4:
+		if (entry->def.cipso == NULL)
+			return -EINVAL;
+		break;
+	case NETLBL_NLTYPE_ADDRSELECT:
+		netlbl_af4list_foreach(iter4, &entry->def.addrsel->list4) {
+			map4 = netlbl_domhsh_addr4_entry(iter4);
+			switch (map4->def.type) {
+			case NETLBL_NLTYPE_UNLABELED:
+				if (map4->def.cipso != NULL)
+					return -EINVAL;
+				break;
+			case NETLBL_NLTYPE_CIPSOV4:
+				if (map4->def.cipso == NULL)
+					return -EINVAL;
+				break;
+			default:
+				return -EINVAL;
+			}
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		netlbl_af6list_foreach(iter6, &entry->def.addrsel->list6) {
+			map6 = netlbl_domhsh_addr6_entry(iter6);
+			switch (map6->def.type) {
+			case NETLBL_NLTYPE_UNLABELED:
+				break;
+			default:
+				return -EINVAL;
+			}
+		}
+#endif /* IPv6 */
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Domain Hash Table Functions
+ */
+
+/**
+ * netlbl_domhsh_init - Init for the domain hash
+ * @size: the number of bits to use for the hash buckets
+ *
+ * Description:
+ * Initializes the domain hash table, should be called only by
+ * netlbl_user_init() during initialization.  Returns zero on success, non-zero
+ * values on error.
+ *
+ */
+int __init netlbl_domhsh_init(u32 size)
+{
+	u32 iter;
+	struct netlbl_domhsh_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]);
+
+	spin_lock(&netlbl_domhsh_lock);
+	rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
+	spin_unlock(&netlbl_domhsh_lock);
+
+	return 0;
+}
+
+/**
+ * netlbl_domhsh_add - Adds a entry to the domain hash table
+ * @entry: the entry to add
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Adds a new entry to the domain hash table and handles any updates to the
+ * lower level protocol handler (i.e. CIPSO).  Returns zero on success,
+ * negative on failure.
+ *
+ */
+int netlbl_domhsh_add(struct netlbl_dom_map *entry,
+		      struct netlbl_audit *audit_info)
+{
+	int ret_val = 0;
+	struct netlbl_dom_map *entry_old;
+	struct netlbl_af4list *iter4;
+	struct netlbl_af4list *tmp4;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct netlbl_af6list *iter6;
+	struct netlbl_af6list *tmp6;
+#endif /* IPv6 */
+
+	ret_val = netlbl_domhsh_validate(entry);
+	if (ret_val != 0)
+		return ret_val;
+
+	/* XXX - we can remove this RCU read lock as the spinlock protects the
+	 *       entire function, but before we do we need to fixup the
+	 *       netlbl_af[4,6]list RCU functions to do "the right thing" with
+	 *       respect to rcu_dereference() when only a spinlock is held. */
+	rcu_read_lock();
+	spin_lock(&netlbl_domhsh_lock);
+	if (entry->domain != NULL)
+		entry_old = netlbl_domhsh_search(entry->domain);
+	else
+		entry_old = netlbl_domhsh_search_def(entry->domain);
+	if (entry_old == NULL) {
+		entry->valid = 1;
+
+		if (entry->domain != NULL) {
+			u32 bkt = netlbl_domhsh_hash(entry->domain);
+			list_add_tail_rcu(&entry->list,
+				    &rcu_dereference(netlbl_domhsh)->tbl[bkt]);
+		} else {
+			INIT_LIST_HEAD(&entry->list);
+			rcu_assign_pointer(netlbl_domhsh_def, entry);
+		}
+
+		if (entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
+			netlbl_af4list_foreach_rcu(iter4,
+						   &entry->def.addrsel->list4)
+				netlbl_domhsh_audit_add(entry, iter4, NULL,
+							ret_val, audit_info);
+#if IS_ENABLED(CONFIG_IPV6)
+			netlbl_af6list_foreach_rcu(iter6,
+						   &entry->def.addrsel->list6)
+				netlbl_domhsh_audit_add(entry, NULL, iter6,
+							ret_val, audit_info);
+#endif /* IPv6 */
+		} else
+			netlbl_domhsh_audit_add(entry, NULL, NULL,
+						ret_val, audit_info);
+	} else if (entry_old->def.type == NETLBL_NLTYPE_ADDRSELECT &&
+		   entry->def.type == NETLBL_NLTYPE_ADDRSELECT) {
+		struct list_head *old_list4;
+		struct list_head *old_list6;
+
+		old_list4 = &entry_old->def.addrsel->list4;
+		old_list6 = &entry_old->def.addrsel->list6;
+
+		/* we only allow the addition of address selectors if all of
+		 * the selectors do not exist in the existing domain map */
+		netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4)
+			if (netlbl_af4list_search_exact(iter4->addr,
+							iter4->mask,
+							old_list4)) {
+				ret_val = -EEXIST;
+				goto add_return;
+			}
+#if IS_ENABLED(CONFIG_IPV6)
+		netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6)
+			if (netlbl_af6list_search_exact(&iter6->addr,
+							&iter6->mask,
+							old_list6)) {
+				ret_val = -EEXIST;
+				goto add_return;
+			}
+#endif /* IPv6 */
+
+		netlbl_af4list_foreach_safe(iter4, tmp4,
+					    &entry->def.addrsel->list4) {
+			netlbl_af4list_remove_entry(iter4);
+			iter4->valid = 1;
+			ret_val = netlbl_af4list_add(iter4, old_list4);
+			netlbl_domhsh_audit_add(entry_old, iter4, NULL,
+						ret_val, audit_info);
+			if (ret_val != 0)
+				goto add_return;
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		netlbl_af6list_foreach_safe(iter6, tmp6,
+					    &entry->def.addrsel->list6) {
+			netlbl_af6list_remove_entry(iter6);
+			iter6->valid = 1;
+			ret_val = netlbl_af6list_add(iter6, old_list6);
+			netlbl_domhsh_audit_add(entry_old, NULL, iter6,
+						ret_val, audit_info);
+			if (ret_val != 0)
+				goto add_return;
+		}
+#endif /* IPv6 */
+	} else
+		ret_val = -EINVAL;
+
+add_return:
+	spin_unlock(&netlbl_domhsh_lock);
+	rcu_read_unlock();
+	return ret_val;
+}
+
+/**
+ * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
+ * @entry: the entry to add
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Adds a new default entry to the domain hash table and handles any updates
+ * to the lower level protocol handler (i.e. CIPSO).  Returns zero on success,
+ * negative on failure.
+ *
+ */
+int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
+			      struct netlbl_audit *audit_info)
+{
+	return netlbl_domhsh_add(entry, audit_info);
+}
+
+/**
+ * netlbl_domhsh_remove_entry - Removes a given entry from the domain table
+ * @entry: the entry to remove
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Removes an entry from the domain hash table and handles any updates to the
+ * lower level protocol handler (i.e. CIPSO).  Caller is responsible for
+ * ensuring that the RCU read lock is held.  Returns zero on success, negative
+ * on failure.
+ *
+ */
+int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry,
+			       struct netlbl_audit *audit_info)
+{
+	int ret_val = 0;
+	struct audit_buffer *audit_buf;
+
+	if (entry == NULL)
+		return -ENOENT;
+
+	spin_lock(&netlbl_domhsh_lock);
+	if (entry->valid) {
+		entry->valid = 0;
+		if (entry != rcu_dereference(netlbl_domhsh_def))
+			list_del_rcu(&entry->list);
+		else
+			RCU_INIT_POINTER(netlbl_domhsh_def, NULL);
+	} else
+		ret_val = -ENOENT;
+	spin_unlock(&netlbl_domhsh_lock);
+
+	audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
+	if (audit_buf != NULL) {
+		audit_log_format(audit_buf,
+				 " nlbl_domain=%s res=%u",
+				 entry->domain ? entry->domain : "(default)",
+				 ret_val == 0 ? 1 : 0);
+		audit_log_end(audit_buf);
+	}
+
+	if (ret_val == 0) {
+		struct netlbl_af4list *iter4;
+		struct netlbl_domaddr4_map *map4;
+
+		switch (entry->def.type) {
+		case NETLBL_NLTYPE_ADDRSELECT:
+			netlbl_af4list_foreach_rcu(iter4,
+					     &entry->def.addrsel->list4) {
+				map4 = netlbl_domhsh_addr4_entry(iter4);
+				cipso_v4_doi_putdef(map4->def.cipso);
+			}
+			/* no need to check the IPv6 list since we currently
+			 * support only unlabeled protocols for IPv6 */
+			break;
+		case NETLBL_NLTYPE_CIPSOV4:
+			cipso_v4_doi_putdef(entry->def.cipso);
+			break;
+		}
+		call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
+	}
+
+	return ret_val;
+}
+
+/**
+ * netlbl_domhsh_remove_af4 - Removes an address selector entry
+ * @domain: the domain
+ * @addr: IPv4 address
+ * @mask: IPv4 address mask
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Removes an individual address selector from a domain mapping and potentially
+ * the entire mapping if it is empty.  Returns zero on success, negative values
+ * on failure.
+ *
+ */
+int netlbl_domhsh_remove_af4(const char *domain,
+			     const struct in_addr *addr,
+			     const struct in_addr *mask,
+			     struct netlbl_audit *audit_info)
+{
+	struct netlbl_dom_map *entry_map;
+	struct netlbl_af4list *entry_addr;
+	struct netlbl_af4list *iter4;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct netlbl_af6list *iter6;
+#endif /* IPv6 */
+	struct netlbl_domaddr4_map *entry;
+
+	rcu_read_lock();
+
+	if (domain)
+		entry_map = netlbl_domhsh_search(domain);
+	else
+		entry_map = netlbl_domhsh_search_def(domain);
+	if (entry_map == NULL ||
+	    entry_map->def.type != NETLBL_NLTYPE_ADDRSELECT)
+		goto remove_af4_failure;
+
+	spin_lock(&netlbl_domhsh_lock);
+	entry_addr = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
+					   &entry_map->def.addrsel->list4);
+	spin_unlock(&netlbl_domhsh_lock);
+
+	if (entry_addr == NULL)
+		goto remove_af4_failure;
+	netlbl_af4list_foreach_rcu(iter4, &entry_map->def.addrsel->list4)
+		goto remove_af4_single_addr;
+#if IS_ENABLED(CONFIG_IPV6)
+	netlbl_af6list_foreach_rcu(iter6, &entry_map->def.addrsel->list6)
+		goto remove_af4_single_addr;
+#endif /* IPv6 */
+	/* the domain mapping is empty so remove it from the mapping table */
+	netlbl_domhsh_remove_entry(entry_map, audit_info);
+
+remove_af4_single_addr:
+	rcu_read_unlock();
+	/* yick, we can't use call_rcu here because we don't have a rcu head
+	 * pointer but hopefully this should be a rare case so the pause
+	 * shouldn't be a problem */
+	synchronize_rcu();
+	entry = netlbl_domhsh_addr4_entry(entry_addr);
+	cipso_v4_doi_putdef(entry->def.cipso);
+	kfree(entry);
+	return 0;
+
+remove_af4_failure:
+	rcu_read_unlock();
+	return -ENOENT;
+}
+
+/**
+ * netlbl_domhsh_remove - Removes an entry from the domain hash table
+ * @domain: the domain to remove
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Removes an entry from the domain hash table and handles any updates to the
+ * lower level protocol handler (i.e. CIPSO).  Returns zero on success,
+ * negative on failure.
+ *
+ */
+int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info)
+{
+	int ret_val;
+	struct netlbl_dom_map *entry;
+
+	rcu_read_lock();
+	if (domain)
+		entry = netlbl_domhsh_search(domain);
+	else
+		entry = netlbl_domhsh_search_def(domain);
+	ret_val = netlbl_domhsh_remove_entry(entry, audit_info);
+	rcu_read_unlock();
+
+	return ret_val;
+}
+
+/**
+ * netlbl_domhsh_remove_default - Removes the default entry from the table
+ * @audit_info: NetLabel audit information
+ *
+ * Description:
+ * Removes/resets the default entry for the domain hash table and handles any
+ * updates to the lower level protocol handler (i.e. CIPSO).  Returns zero on
+ * success, non-zero on failure.
+ *
+ */
+int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info)
+{
+	return netlbl_domhsh_remove(NULL, audit_info);
+}
+
+/**
+ * netlbl_domhsh_getentry - Get an entry from the domain hash table
+ * @domain: the domain name to search for
+ *
+ * Description:
+ * Look through the domain hash table searching for an entry to match @domain,
+ * return a pointer to a copy of the entry or NULL.  The caller is responsible
+ * for ensuring that rcu_read_[un]lock() is called.
+ *
+ */
+struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
+{
+	return netlbl_domhsh_search_def(domain);
+}
+
+/**
+ * netlbl_domhsh_getentry_af4 - Get an entry from the domain hash table
+ * @domain: the domain name to search for
+ * @addr: the IP address to search for
+ *
+ * Description:
+ * Look through the domain hash table searching for an entry to match @domain
+ * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
+ * responsible for ensuring that rcu_read_[un]lock() is called.
+ *
+ */
+struct netlbl_dommap_def *netlbl_domhsh_getentry_af4(const char *domain,
+						     __be32 addr)
+{
+	struct netlbl_dom_map *dom_iter;
+	struct netlbl_af4list *addr_iter;
+
+	dom_iter = netlbl_domhsh_search_def(domain);
+	if (dom_iter == NULL)
+		return NULL;
+
+	if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
+		return &dom_iter->def;
+	addr_iter = netlbl_af4list_search(addr, &dom_iter->def.addrsel->list4);
+	if (addr_iter == NULL)
+		return NULL;
+	return &(netlbl_domhsh_addr4_entry(addr_iter)->def);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/**
+ * netlbl_domhsh_getentry_af6 - Get an entry from the domain hash table
+ * @domain: the domain name to search for
+ * @addr: the IP address to search for
+ *
+ * Description:
+ * Look through the domain hash table searching for an entry to match @domain
+ * and @addr, return a pointer to a copy of the entry or NULL.  The caller is
+ * responsible for ensuring that rcu_read_[un]lock() is called.
+ *
+ */
+struct netlbl_dommap_def *netlbl_domhsh_getentry_af6(const char *domain,
+						   const struct in6_addr *addr)
+{
+	struct netlbl_dom_map *dom_iter;
+	struct netlbl_af6list *addr_iter;
+
+	dom_iter = netlbl_domhsh_search_def(domain);
+	if (dom_iter == NULL)
+		return NULL;
+
+	if (dom_iter->def.type != NETLBL_NLTYPE_ADDRSELECT)
+		return &dom_iter->def;
+	addr_iter = netlbl_af6list_search(addr, &dom_iter->def.addrsel->list6);
+	if (addr_iter == NULL)
+		return NULL;
+	return &(netlbl_domhsh_addr6_entry(addr_iter)->def);
+}
+#endif /* IPv6 */
+
+/**
+ * netlbl_domhsh_walk - Iterate through the domain mapping hash table
+ * @skip_bkt: the number of buckets to skip at the start
+ * @skip_chain: the number of entries to skip in the first iterated bucket
+ * @callback: callback for each entry
+ * @cb_arg: argument for the callback function
+ *
+ * Description:
+ * Interate over the domain mapping hash table, skipping the first @skip_bkt
+ * buckets and @skip_chain entries.  For each entry in the table call
+ * @callback, if @callback returns a negative value stop 'walking' through the
+ * table and return.  Updates the values in @skip_bkt and @skip_chain on
+ * return.  Returns zero on success, negative values on failure.
+ *
+ */
+int netlbl_domhsh_walk(u32 *skip_bkt,
+		     u32 *skip_chain,
+		     int (*callback) (struct netlbl_dom_map *entry, void *arg),
+		     void *cb_arg)
+{
+	int ret_val = -ENOENT;
+	u32 iter_bkt;
+	struct list_head *iter_list;
+	struct netlbl_dom_map *iter_entry;
+	u32 chain_cnt = 0;
+
+	rcu_read_lock();
+	for (iter_bkt = *skip_bkt;
+	     iter_bkt < rcu_dereference(netlbl_domhsh)->size;
+	     iter_bkt++, chain_cnt = 0) {
+		iter_list = &rcu_dereference(netlbl_domhsh)->tbl[iter_bkt];
+		list_for_each_entry_rcu(iter_entry, iter_list, list)
+			if (iter_entry->valid) {
+				if (chain_cnt++ < *skip_chain)
+					continue;
+				ret_val = callback(iter_entry, cb_arg);
+				if (ret_val < 0) {
+					chain_cnt--;
+					goto walk_return;
+				}
+			}
+	}
+
+walk_return:
+	rcu_read_unlock();
+	*skip_bkt = iter_bkt;
+	*skip_chain = chain_cnt;
+	return ret_val;
+}