linux/security/selinux/ss/avtab.h
Stephen Smalley cf7b6c0205 selinux: increase avtab max buckets
Now that we can safely increase the avtab max buckets without
triggering high order allocations and have a hash function that
will make better use of the larger number of buckets, increase
the max buckets to 2^16.

Original:
101421 entries and 2048/2048 buckets used, longest chain length 374

With new hash function:
101421 entries and 2048/2048 buckets used, longest chain length 81

With increased max buckets:
101421 entries and 31078/32768 buckets used, longest chain length 12

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-04-06 20:16:23 -04:00

94 lines
2.9 KiB
C

/*
* An access vector table (avtab) is a hash table
* of access vectors and transition types indexed
* by a type pair and a class. An access vector
* table is used to represent the type enforcement
* tables.
*
* Author : Stephen Smalley, <sds@epoch.ncsc.mil>
*/
/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
*
* Added conditional policy language extensions
*
* Copyright (C) 2003 Tresys Technology, LLC
* 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, version 2.
*
* Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
* Tuned number of hash slots for avtab to reduce memory usage
*/
#ifndef _SS_AVTAB_H_
#define _SS_AVTAB_H_
#include <linux/flex_array.h>
struct avtab_key {
u16 source_type; /* source type */
u16 target_type; /* target type */
u16 target_class; /* target object class */
#define AVTAB_ALLOWED 0x0001
#define AVTAB_AUDITALLOW 0x0002
#define AVTAB_AUDITDENY 0x0004
#define AVTAB_AV (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
#define AVTAB_TRANSITION 0x0010
#define AVTAB_MEMBER 0x0020
#define AVTAB_CHANGE 0x0040
#define AVTAB_TYPE (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
#define AVTAB_ENABLED_OLD 0x80000000 /* reserved for used in cond_avtab */
#define AVTAB_ENABLED 0x8000 /* reserved for used in cond_avtab */
u16 specified; /* what field is specified */
};
struct avtab_datum {
u32 data; /* access vector or type value */
};
struct avtab_node {
struct avtab_key key;
struct avtab_datum datum;
struct avtab_node *next;
};
struct avtab {
struct flex_array *htable;
u32 nel; /* number of elements */
u32 nslot; /* number of hash slots */
u32 mask; /* mask to compute hash func */
};
int avtab_init(struct avtab *);
int avtab_alloc(struct avtab *, u32);
struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
void avtab_destroy(struct avtab *h);
void avtab_hash_eval(struct avtab *h, char *tag);
struct policydb;
int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
int (*insert)(struct avtab *a, struct avtab_key *k,
struct avtab_datum *d, void *p),
void *p);
int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
int avtab_write(struct policydb *p, struct avtab *a, void *fp);
struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
struct avtab_datum *datum);
struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
void avtab_cache_init(void);
void avtab_cache_destroy(void);
#define MAX_AVTAB_HASH_BITS 16
#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
#endif /* _SS_AVTAB_H_ */