android_kernel_xiaomi_sm8350/net/netlabel/netlabel_domainhash.c
Paul Moore 63c4168874 netlabel: Add network address selectors to the NetLabel/LSM domain mapping
This patch extends the NetLabel traffic labeling capabilities to individual
packets based not only on the LSM domain but the by the destination address
as well.  The changes here only affect the core NetLabel infrastructre,
changes to the NetLabel KAPI and individial protocol engines are also
required but are split out into a different patch to ease review.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:32 -04:00

655 lines
18 KiB
C

/*
* 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, 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/rculist.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/audit.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 */
/* XXX - updates should be so rare that having one spinlock for the entire
* hash table should be okay */
static DEFINE_SPINLOCK(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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
struct netlbl_af6list *iter6;
struct netlbl_af6list *tmp6;
#endif /* IPv6 */
ptr = container_of(entry, struct netlbl_dom_map, rcu);
if (ptr->type == NETLBL_NLTYPE_ADDRSELECT) {
netlbl_af4list_foreach_safe(iter4, tmp4,
&ptr->type_def.addrsel->list4) {
netlbl_af4list_remove_entry(iter4);
kfree(netlbl_domhsh_addr4_entry(iter4));
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
netlbl_af6list_foreach_safe(iter6, tmp6,
&ptr->type_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 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
*
* Description:
* Searches the domain hash table and returns a pointer to the hash table
* entry if found, otherwise NULL is returned. 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 bkt;
struct list_head *bkt_list;
struct netlbl_dom_map *iter;
if (domain != NULL) {
bkt = netlbl_domhsh_hash(domain);
bkt_list = &rcu_dereference(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 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_def(const char *domain)
{
struct netlbl_dom_map *entry;
entry = netlbl_domhsh_search(domain);
if (entry == NULL) {
entry = rcu_dereference(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 responsibile 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->type;
cipsov4 = map4->type_def.cipsov4;
netlbl_af4list_audit_addr(audit_buf, 0, NULL,
addr4->addr, addr4->mask);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
} else if (addr6 != NULL) {
struct netlbl_domaddr6_map *map6;
map6 = netlbl_domhsh_addr6_entry(addr6);
type = map6->type;
netlbl_af6list_audit_addr(audit_buf, 0, NULL,
&addr6->addr, &addr6->mask);
#endif /* IPv6 */
} else {
type = entry->type;
cipsov4 = entry->type_def.cipsov4;
}
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);
}
}
/*
* 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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
struct netlbl_af6list *iter6;
struct netlbl_af6list *tmp6;
#endif /* IPv6 */
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;
INIT_RCU_HEAD(&entry->rcu);
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->type == NETLBL_NLTYPE_ADDRSELECT) {
netlbl_af4list_foreach_rcu(iter4,
&entry->type_def.addrsel->list4)
netlbl_domhsh_audit_add(entry, iter4, NULL,
ret_val, audit_info);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
netlbl_af6list_foreach_rcu(iter6,
&entry->type_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->type == NETLBL_NLTYPE_ADDRSELECT &&
entry->type == NETLBL_NLTYPE_ADDRSELECT) {
struct list_head *old_list4;
struct list_head *old_list6;
old_list4 = &entry_old->type_def.addrsel->list4;
old_list6 = &entry_old->type_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->type_def.addrsel->list4)
if (netlbl_af4list_search_exact(iter4->addr,
iter4->mask,
old_list4)) {
ret_val = -EEXIST;
goto add_return;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
netlbl_af6list_foreach_rcu(iter6,
&entry->type_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->type_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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
netlbl_af6list_foreach_safe(iter6, tmp6,
&entry->type_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_assign_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->type) {
case NETLBL_NLTYPE_ADDRSELECT:
netlbl_af4list_foreach_rcu(iter4,
&entry->type_def.addrsel->list4) {
map4 = netlbl_domhsh_addr4_entry(iter4);
cipso_v4_doi_putdef(map4->type_def.cipsov4);
}
/* 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->type_def.cipsov4);
break;
}
call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
}
return ret_val;
}
/**
* 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 responsibile
* 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_domaddr4_map *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->type != NETLBL_NLTYPE_ADDRSELECT)
return NULL;
addr_iter = netlbl_af4list_search(addr,
&dom_iter->type_def.addrsel->list4);
if (addr_iter == NULL)
return NULL;
return netlbl_domhsh_addr4_entry(addr_iter);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
/**
* 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_domaddr6_map *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->type != NETLBL_NLTYPE_ADDRSELECT)
return NULL;
addr_iter = netlbl_af6list_search(addr,
&dom_iter->type_def.addrsel->list6);
if (addr_iter == NULL)
return NULL;
return netlbl_domhsh_addr6_entry(addr_iter);
}
#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 succcess, 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;
}