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Diffstat (limited to 'net/netlabel/netlabel_domainhash.c')
-rw-r--r--net/netlabel/netlabel_domainhash.c513
1 files changed, 513 insertions, 0 deletions
diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c
new file mode 100644
index 000000000000..5bb3fad4a115
--- /dev/null
+++ b/net/netlabel/netlabel_domainhash.c
@@ -0,0 +1,513 @@
+/*
+ * 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.moore@hp.com>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ *
+ * 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/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <net/netlabel.h>
+#include <net/cipso_ipv4.h>
+#include <asm/bug.h>
+
+#include "netlabel_mgmt.h"
+#include "netlabel_domainhash.h"
+
+struct netlbl_domhsh_tbl {
+ struct list_head *tbl;
+ u32 size;
+};
+
+/* Domain hash table */
+/* XXX - updates should be so rare that having one spinlock for the entire
+ * hash table should be okay */
+DEFINE_SPINLOCK(netlbl_domhsh_lock);
+static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
+
+/* Default domain mapping */
+DEFINE_SPINLOCK(netlbl_domhsh_def_lock);
+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;
+
+ ptr = container_of(entry, struct netlbl_dom_map, rcu);
+ 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 responsibile for
+ * calling the rcu_read_[un]lock() functions.
+ *
+ */
+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 & (rcu_dereference(netlbl_domhsh)->size - 1);
+}
+
+/**
+ * netlbl_domhsh_search - 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 found, otherwise NULL is returned. If @def is non-zero and a
+ * match is not found in the domain hash table the default mapping is returned
+ * if it exists. The caller is responsibile for the rcu hash table locks
+ * (i.e. the caller much call rcu_read_[un]lock()).
+ *
+ */
+static struct netlbl_dom_map *netlbl_domhsh_search(const char *domain, u32 def)
+{
+ u32 bkt;
+ struct netlbl_dom_map *iter;
+
+ if (domain != NULL) {
+ bkt = netlbl_domhsh_hash(domain);
+ list_for_each_entry_rcu(iter, &netlbl_domhsh->tbl[bkt], list)
+ if (iter->valid && strcmp(iter->domain, domain) == 0)
+ return iter;
+ }
+
+ if (def != 0) {
+ iter = rcu_dereference(netlbl_domhsh_def);
+ if (iter != NULL && iter->valid)
+ return iter;
+ }
+
+ return NULL;
+}
+
+/*
+ * 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 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]);
+
+ rcu_read_lock();
+ spin_lock(&netlbl_domhsh_lock);
+ rcu_assign_pointer(netlbl_domhsh, hsh_tbl);
+ spin_unlock(&netlbl_domhsh_lock);
+ rcu_read_unlock();
+
+ return 0;
+}
+
+/**
+ * netlbl_domhsh_add - Adds a entry to the domain hash table
+ * @entry: the entry to add
+ *
+ * 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)
+{
+ int ret_val;
+ u32 bkt;
+
+ switch (entry->type) {
+ case NETLBL_NLTYPE_UNLABELED:
+ ret_val = 0;
+ break;
+ case NETLBL_NLTYPE_CIPSOV4:
+ ret_val = cipso_v4_doi_domhsh_add(entry->type_def.cipsov4,
+ entry->domain);
+ break;
+ default:
+ return -EINVAL;
+ }
+ if (ret_val != 0)
+ return ret_val;
+
+ entry->valid = 1;
+ INIT_RCU_HEAD(&entry->rcu);
+
+ ret_val = 0;
+ rcu_read_lock();
+ if (entry->domain != NULL) {
+ bkt = netlbl_domhsh_hash(entry->domain);
+ spin_lock(&netlbl_domhsh_lock);
+ if (netlbl_domhsh_search(entry->domain, 0) == NULL)
+ list_add_tail_rcu(&entry->list,
+ &netlbl_domhsh->tbl[bkt]);
+ else
+ ret_val = -EEXIST;
+ spin_unlock(&netlbl_domhsh_lock);
+ } else if (entry->domain == NULL) {
+ INIT_LIST_HEAD(&entry->list);
+ spin_lock(&netlbl_domhsh_def_lock);
+ if (rcu_dereference(netlbl_domhsh_def) == NULL)
+ rcu_assign_pointer(netlbl_domhsh_def, entry);
+ else
+ ret_val = -EEXIST;
+ spin_unlock(&netlbl_domhsh_def_lock);
+ } else
+ ret_val = -EINVAL;
+ rcu_read_unlock();
+
+ if (ret_val != 0) {
+ switch (entry->type) {
+ case NETLBL_NLTYPE_CIPSOV4:
+ if (cipso_v4_doi_domhsh_remove(entry->type_def.cipsov4,
+ entry->domain) != 0)
+ BUG();
+ break;
+ }
+ }
+
+ return ret_val;
+}
+
+/**
+ * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
+ * @entry: the entry to add
+ *
+ * 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)
+{
+ return netlbl_domhsh_add(entry);
+}
+
+/**
+ * netlbl_domhsh_remove - Removes an entry from the domain hash table
+ * @domain: the domain to remove
+ *
+ * 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)
+{
+ int ret_val = -ENOENT;
+ struct netlbl_dom_map *entry;
+
+ rcu_read_lock();
+ if (domain != NULL)
+ entry = netlbl_domhsh_search(domain, 0);
+ else
+ entry = netlbl_domhsh_search(domain, 1);
+ if (entry == NULL)
+ goto remove_return;
+ switch (entry->type) {
+ case NETLBL_NLTYPE_UNLABELED:
+ break;
+ case NETLBL_NLTYPE_CIPSOV4:
+ ret_val = cipso_v4_doi_domhsh_remove(entry->type_def.cipsov4,
+ entry->domain);
+ if (ret_val != 0)
+ goto remove_return;
+ break;
+ }
+ ret_val = 0;
+ if (entry != rcu_dereference(netlbl_domhsh_def)) {
+ spin_lock(&netlbl_domhsh_lock);
+ if (entry->valid) {
+ entry->valid = 0;
+ list_del_rcu(&entry->list);
+ } else
+ ret_val = -ENOENT;
+ spin_unlock(&netlbl_domhsh_lock);
+ } else {
+ spin_lock(&netlbl_domhsh_def_lock);
+ if (entry->valid) {
+ entry->valid = 0;
+ rcu_assign_pointer(netlbl_domhsh_def, NULL);
+ } else
+ ret_val = -ENOENT;
+ spin_unlock(&netlbl_domhsh_def_lock);
+ }
+ if (ret_val == 0)
+ call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
+
+remove_return:
+ rcu_read_unlock();
+ return ret_val;
+}
+
+/**
+ * netlbl_domhsh_remove_default - Removes the default entry from the table
+ *
+ * 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(void)
+{
+ return netlbl_domhsh_remove(NULL);
+}
+
+/**
+ * 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 responsibile
+ * for ensuring that rcu_read_[un]lock() is called.
+ *
+ */
+struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
+{
+ return netlbl_domhsh_search(domain, 1);
+}
+
+/**
+ * netlbl_domhsh_dump - Dump the domain hash table into a sk_buff
+ *
+ * Description:
+ * Dump the domain hash table into a buffer suitable for returning to an
+ * application in response to a NetLabel management DOMAIN message. This
+ * function may fail if another process is growing the hash table at the same
+ * time. The returned sk_buff has room at the front of the sk_buff for
+ * @headroom bytes. See netlabel.h for the DOMAIN message format. Returns a
+ * pointer to a sk_buff on success, NULL on error.
+ *
+ */
+struct sk_buff *netlbl_domhsh_dump(size_t headroom)
+{
+ struct sk_buff *skb = NULL;
+ ssize_t buf_len;
+ u32 bkt_iter;
+ u32 dom_cnt = 0;
+ struct netlbl_domhsh_tbl *hsh_tbl;
+ struct netlbl_dom_map *list_iter;
+ ssize_t tmp_len;
+
+ buf_len = NETLBL_LEN_U32;
+ rcu_read_lock();
+ hsh_tbl = rcu_dereference(netlbl_domhsh);
+ for (bkt_iter = 0; bkt_iter < hsh_tbl->size; bkt_iter++)
+ list_for_each_entry_rcu(list_iter,
+ &hsh_tbl->tbl[bkt_iter], list) {
+ buf_len += NETLBL_LEN_U32 +
+ nla_total_size(strlen(list_iter->domain) + 1);
+ switch (list_iter->type) {
+ case NETLBL_NLTYPE_UNLABELED:
+ break;
+ case NETLBL_NLTYPE_CIPSOV4:
+ buf_len += 2 * NETLBL_LEN_U32;
+ break;
+ }
+ dom_cnt++;
+ }
+
+ skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
+ if (skb == NULL)
+ goto dump_failure;
+
+ if (nla_put_u32(skb, NLA_U32, dom_cnt) != 0)
+ goto dump_failure;
+ buf_len -= NETLBL_LEN_U32;
+ hsh_tbl = rcu_dereference(netlbl_domhsh);
+ for (bkt_iter = 0; bkt_iter < hsh_tbl->size; bkt_iter++)
+ list_for_each_entry_rcu(list_iter,
+ &hsh_tbl->tbl[bkt_iter], list) {
+ tmp_len = nla_total_size(strlen(list_iter->domain) +
+ 1);
+ if (buf_len < NETLBL_LEN_U32 + tmp_len)
+ goto dump_failure;
+ if (nla_put_string(skb,
+ NLA_STRING,
+ list_iter->domain) != 0)
+ goto dump_failure;
+ if (nla_put_u32(skb, NLA_U32, list_iter->type) != 0)
+ goto dump_failure;
+ buf_len -= NETLBL_LEN_U32 + tmp_len;
+ switch (list_iter->type) {
+ case NETLBL_NLTYPE_UNLABELED:
+ break;
+ case NETLBL_NLTYPE_CIPSOV4:
+ if (buf_len < 2 * NETLBL_LEN_U32)
+ goto dump_failure;
+ if (nla_put_u32(skb,
+ NLA_U32,
+ list_iter->type_def.cipsov4->type) != 0)
+ goto dump_failure;
+ if (nla_put_u32(skb,
+ NLA_U32,
+ list_iter->type_def.cipsov4->doi) != 0)
+ goto dump_failure;
+ buf_len -= 2 * NETLBL_LEN_U32;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return skb;
+
+dump_failure:
+ rcu_read_unlock();
+ kfree_skb(skb);
+ return NULL;
+}
+
+/**
+ * netlbl_domhsh_dump_default - Dump the default domain mapping into a sk_buff
+ *
+ * Description:
+ * Dump the default domain mapping into a buffer suitable for returning to an
+ * application in response to a NetLabel management DEFDOMAIN message. This
+ * function may fail if another process is changing the default domain mapping
+ * at the same time. The returned sk_buff has room at the front of the
+ * skb_buff for @headroom bytes. See netlabel.h for the DEFDOMAIN message
+ * format. Returns a pointer to a sk_buff on success, NULL on error.
+ *
+ */
+struct sk_buff *netlbl_domhsh_dump_default(size_t headroom)
+{
+ struct sk_buff *skb;
+ ssize_t buf_len;
+ struct netlbl_dom_map *entry;
+
+ buf_len = NETLBL_LEN_U32;
+ rcu_read_lock();
+ entry = rcu_dereference(netlbl_domhsh_def);
+ if (entry != NULL)
+ switch (entry->type) {
+ case NETLBL_NLTYPE_UNLABELED:
+ break;
+ case NETLBL_NLTYPE_CIPSOV4:
+ buf_len += 2 * NETLBL_LEN_U32;
+ break;
+ }
+
+ skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
+ if (skb == NULL)
+ goto dump_default_failure;
+
+ if (entry != rcu_dereference(netlbl_domhsh_def))
+ goto dump_default_failure;
+ if (entry != NULL) {
+ if (nla_put_u32(skb, NLA_U32, entry->type) != 0)
+ goto dump_default_failure;
+ buf_len -= NETLBL_LEN_U32;
+ switch (entry->type) {
+ case NETLBL_NLTYPE_UNLABELED:
+ break;
+ case NETLBL_NLTYPE_CIPSOV4:
+ if (buf_len < 2 * NETLBL_LEN_U32)
+ goto dump_default_failure;
+ if (nla_put_u32(skb,
+ NLA_U32,
+ entry->type_def.cipsov4->type) != 0)
+ goto dump_default_failure;
+ if (nla_put_u32(skb,
+ NLA_U32,
+ entry->type_def.cipsov4->doi) != 0)
+ goto dump_default_failure;
+ buf_len -= 2 * NETLBL_LEN_U32;
+ break;
+ }
+ } else
+ nla_put_u32(skb, NLA_U32, NETLBL_NLTYPE_NONE);
+ rcu_read_unlock();
+
+ return skb;
+
+dump_default_failure:
+ rcu_read_unlock();
+ kfree_skb(skb);
+ return NULL;
+}