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 #include <linux/flex_array.h>
  27
  28 struct avtab_key {
  29         u16 source_type;        /* source type */
  30         u16 target_type;        /* target type */
  31         u16 target_class;       /* target object class */
  32 #define AVTAB_ALLOWED           0x0001
  33 #define AVTAB_AUDITALLOW        0x0002
  34 #define AVTAB_AUDITDENY         0x0004
  35 #define AVTAB_AV                (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
  36 #define AVTAB_TRANSITION        0x0010
  37 #define AVTAB_MEMBER            0x0020
  38 #define AVTAB_CHANGE            0x0040
  39 #define AVTAB_TYPE              (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
  40 #define AVTAB_ENABLED_OLD   0x80000000 /* reserved for used in cond_avtab */
  41 #define AVTAB_ENABLED           0x8000 /* reserved for used in cond_avtab */
  42         u16 specified;  /* what field is specified */
  43 };
  44
  45 struct avtab_datum {
  46         u32 data; /* access vector or type value */
  47 };
  48
  49 struct avtab_node {
  50         struct avtab_key key;
  51         struct avtab_datum datum;
  52         struct avtab_node *next;
  53 };
  54
  55 struct avtab {
  56         struct flex_array *htable;
  57         u32 nel;        /* number of elements */
  58         u32 nslot;      /* number of hash slots */
  59         u32 mask;       /* mask to compute hash func */
  60
  61 };
  62
  63 int avtab_init(struct avtab *);
  64 int avtab_alloc(struct avtab *, u32);
  65 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
  66 void avtab_destroy(struct avtab *h);
  67 void avtab_hash_eval(struct avtab *h, char *tag);
  68
  69 struct policydb;
  70 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
  71                     int (*insert)(struct avtab *a, struct avtab_key *k,
  72                                   struct avtab_datum *d, void *p),
  73                     void *p);
  74
  75 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
  76 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
  77 int avtab_write(struct policydb *p, struct avtab *a, void *fp);
  78
  79 struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
  80                                           struct avtab_datum *datum);
  81
  82 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
  83
  84 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
  85
  86 void avtab_cache_init(void);
  87 void avtab_cache_destroy(void);
  88
  89 #define MAX_AVTAB_HASH_BITS 16
  90 #define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
  91
  92 #endif  /* _SS_AVTAB_H_ */
  93