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
  26 struct 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
  43 struct avtab_datum {
  44         u32 data; /* access vector or type value */
  45 };
  46
  47 struct avtab_node {
  48         struct avtab_key key;
  49         struct avtab_datum datum;
  50         struct avtab_node *next;
  51 };
  52
  53 struct 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
  61 int avtab_init(struct avtab *);
  62 int avtab_alloc(struct avtab *, u32);
  63 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
  64 void avtab_destroy(struct avtab *h);
  65 void avtab_hash_eval(struct avtab *h, char *tag);
  66
  67 struct policydb;
  68 int 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
  73 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
  74
  75 struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
  76                                           struct avtab_datum *datum);
  77
  78 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
  79
  80 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
  81
  82 void avtab_cache_init(void);
  83 void 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