linux/security/selinux/ibpkey.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Pkey table
 *
 * SELinux must keep a mapping of Infinband PKEYs to labels/SIDs.  This
 * mapping is maintained as part of the normal policy but a fast cache is
 * needed to reduce the lookup overhead.
 *
 * This code is heavily based on the "netif" and "netport" concept originally
 * developed by
 * James Morris <[email protected]> and
 * Paul Moore <[email protected]>
 *   (see security/selinux/netif.c and security/selinux/netport.c for more
 *   information)
 */

/*
 * (c) Mellanox Technologies, 2016
 */

#include <linux/types.h>
#include <linux/rcupdate.h>
#include <linux/list.h>
#include <linux/spinlock.h>

#include "ibpkey.h"
#include "objsec.h"

#define SEL_PKEY_HASH_SIZE …
#define SEL_PKEY_HASH_BKT_LIMIT …

struct sel_ib_pkey_bkt { … };

struct sel_ib_pkey { … };

static DEFINE_SPINLOCK(sel_ib_pkey_lock);
static struct sel_ib_pkey_bkt sel_ib_pkey_hash[SEL_PKEY_HASH_SIZE];

/**
 * sel_ib_pkey_hashfn - Hashing function for the pkey table
 * @pkey: pkey number
 *
 * Description:
 * This is the hashing function for the pkey table, it returns the bucket
 * number for the given pkey.
 *
 */
static unsigned int sel_ib_pkey_hashfn(u16 pkey)
{ … }

/**
 * sel_ib_pkey_find - Search for a pkey record
 * @subnet_prefix: subnet_prefix
 * @pkey_num: pkey_num
 *
 * Description:
 * Search the pkey table and return the matching record.  If an entry
 * can not be found in the table return NULL.
 *
 */
static struct sel_ib_pkey *sel_ib_pkey_find(u64 subnet_prefix, u16 pkey_num)
{ … }

/**
 * sel_ib_pkey_insert - Insert a new pkey into the table
 * @pkey: the new pkey record
 *
 * Description:
 * Add a new pkey record to the hash table.
 *
 */
static void sel_ib_pkey_insert(struct sel_ib_pkey *pkey)
{ … }

/**
 * sel_ib_pkey_sid_slow - Lookup the SID of a pkey using the policy
 * @subnet_prefix: subnet prefix
 * @pkey_num: pkey number
 * @sid: pkey SID
 *
 * Description:
 * This function determines the SID of a pkey by querying the security
 * policy.  The result is added to the pkey table to speedup future
 * queries.  Returns zero on success, negative values on failure.
 *
 */
static int sel_ib_pkey_sid_slow(u64 subnet_prefix, u16 pkey_num, u32 *sid)
{ … }

/**
 * sel_ib_pkey_sid - Lookup the SID of a PKEY
 * @subnet_prefix: subnet_prefix
 * @pkey_num: pkey number
 * @sid: pkey SID
 *
 * Description:
 * This function determines the SID of a PKEY using the fastest method
 * possible.  First the pkey table is queried, but if an entry can't be found
 * then the policy is queried and the result is added to the table to speedup
 * future queries.  Returns zero on success, negative values on failure.
 *
 */
int sel_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *sid)
{ … }

/**
 * sel_ib_pkey_flush - Flush the entire pkey table
 *
 * Description:
 * Remove all entries from the pkey table
 *
 */
void sel_ib_pkey_flush(void)
{ … }

static __init int sel_ib_pkey_init(void)
{ … }

subsys_initcall(sel_ib_pkey_init);