LXR linux/security/selinux/ss/avtab.h

   1/*
   2 * An access vector table (avtab) is a hash table
   3 * of access vectors and transition types indexed
   4 * by a type pair and a class.  An access vector
   5 * table is used to represent the type enforcement
   6 * tables.
   7 *
   8 *  Author : Stephen Smalley, <sds@epoch.ncsc.mil>
   9 */
  10
  11/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  12 *
  13 *      Added conditional policy language extensions
  14 *
  15 * Copyright (C) 2003 Tresys Technology, LLC
  16 *      This program is free software; you can redistribute it and/or modify
  17 *      it under the terms of the GNU General Public License as published by
  18 *      the Free Software Foundation, version 2.
  19 *
  20 * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
  21 *      Tuned number of hash slots for avtab to reduce memory usage
  22 */
  23#ifndef _SS_AVTAB_H_
  24#define _SS_AVTAB_H_
  25
  26struct avtab_key {
  27        u16 source_type;        /* source type */
  28        u16 target_type;        /* target type */
  29        u16 target_class;       /* target object class */
  30#define AVTAB_ALLOWED     1
  31#define AVTAB_AUDITALLOW  2
  32#define AVTAB_AUDITDENY   4
  33#define AVTAB_AV         (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
  34#define AVTAB_TRANSITION 16
  35#define AVTAB_MEMBER     32
  36#define AVTAB_CHANGE     64
  37#define AVTAB_TYPE       (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
  38#define AVTAB_ENABLED_OLD    0x80000000 /* reserved for used in cond_avtab */
  39#define AVTAB_ENABLED    0x8000 /* reserved for used in cond_avtab */
  40        u16 specified;  /* what field is specified */
  41};
  42
  43struct avtab_datum {
  44        u32 data; /* access vector or type value */
  45};
  46
  47struct avtab_node {
  48        struct avtab_key key;
  49        struct avtab_datum datum;
  50        struct avtab_node *next;
  51};
  52
  53struct avtab {
  54        struct avtab_node **htable;
  55        u32 nel;        /* number of elements */
  56        u32 nslot;      /* number of hash slots */
  57        u16 mask;       /* mask to compute hash func */
  58
  59};
  60
  61int avtab_init(struct avtab *);
  62int avtab_alloc(struct avtab *, u32);
  63struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
  64void avtab_destroy(struct avtab *h);
  65void avtab_hash_eval(struct avtab *h, char *tag);
  66
  67struct policydb;
  68int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
  69                    int (*insert)(struct avtab *a, struct avtab_key *k,
  70                                  struct avtab_datum *d, void *p),
  71                    void *p);
  72
  73int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
  74
  75struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
  76                                          struct avtab_datum *datum);
  77
  78struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
  79
  80struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
  81
  82void avtab_cache_init(void);
  83void avtab_cache_destroy(void);
  84
  85#define MAX_AVTAB_HASH_BITS 13
  86#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
  87#define MAX_AVTAB_HASH_MASK (MAX_AVTAB_HASH_BUCKETS-1)
  88#define MAX_AVTAB_SIZE MAX_AVTAB_HASH_BUCKETS
  89
  90#endif  /* _SS_AVTAB_H_ */
  91
  92