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@tycho.nsa.gov>
   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 "security.h"
  27#include <linux/flex_array.h>
  28
  29struct avtab_key {
  30        u16 source_type;        /* source type */
  31        u16 target_type;        /* target type */
  32        u16 target_class;       /* target object class */
  33#define AVTAB_ALLOWED           0x0001
  34#define AVTAB_AUDITALLOW        0x0002
  35#define AVTAB_AUDITDENY         0x0004
  36#define AVTAB_AV                (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
  37#define AVTAB_TRANSITION        0x0010
  38#define AVTAB_MEMBER            0x0020
  39#define AVTAB_CHANGE            0x0040
  40#define AVTAB_TYPE              (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
  41/* extended permissions */
  42#define AVTAB_XPERMS_ALLOWED    0x0100
  43#define AVTAB_XPERMS_AUDITALLOW 0x0200
  44#define AVTAB_XPERMS_DONTAUDIT  0x0400
  45#define AVTAB_XPERMS            (AVTAB_XPERMS_ALLOWED | \
  46                                AVTAB_XPERMS_AUDITALLOW | \
  47                                AVTAB_XPERMS_DONTAUDIT)
  48#define AVTAB_ENABLED_OLD   0x80000000 /* reserved for used in cond_avtab */
  49#define AVTAB_ENABLED           0x8000 /* reserved for used in cond_avtab */
  50        u16 specified;  /* what field is specified */
  51};
  52
  53/*
  54 * For operations that require more than the 32 permissions provided by the avc
  55 * extended permissions may be used to provide 256 bits of permissions.
  56 */
  57struct avtab_extended_perms {
  58/* These are not flags. All 256 values may be used */
  59#define AVTAB_XPERMS_IOCTLFUNCTION      0x01
  60#define AVTAB_XPERMS_IOCTLDRIVER        0x02
  61        /* extension of the avtab_key specified */
  62        u8 specified; /* ioctl, netfilter, ... */
  63        /*
  64         * if 256 bits is not adequate as is often the case with ioctls, then
  65         * multiple extended perms may be used and the driver field
  66         * specifies which permissions are included.
  67         */
  68        u8 driver;
  69        /* 256 bits of permissions */
  70        struct extended_perms_data perms;
  71};
  72
  73struct avtab_datum {
  74        union {
  75                u32 data; /* access vector or type value */
  76                struct avtab_extended_perms *xperms;
  77        } u;
  78};
  79
  80struct avtab_node {
  81        struct avtab_key key;
  82        struct avtab_datum datum;
  83        struct avtab_node *next;
  84};
  85
  86struct avtab {
  87        struct flex_array *htable;
  88        u32 nel;        /* number of elements */
  89        u32 nslot;      /* number of hash slots */
  90        u32 mask;       /* mask to compute hash func */
  91
  92};
  93
  94int avtab_init(struct avtab *);
  95int avtab_alloc(struct avtab *, u32);
  96struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
  97void avtab_destroy(struct avtab *h);
  98void avtab_hash_eval(struct avtab *h, char *tag);
  99
 100struct policydb;
 101int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
 102                    int (*insert)(struct avtab *a, struct avtab_key *k,
 103                                  struct avtab_datum *d, void *p),
 104                    void *p);
 105
 106int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
 107int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
 108int avtab_write(struct policydb *p, struct avtab *a, void *fp);
 109
 110struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
 111                                          struct avtab_datum *datum);
 112
 113struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
 114
 115struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
 116
 117void avtab_cache_init(void);
 118void avtab_cache_destroy(void);
 119
 120#define MAX_AVTAB_HASH_BITS 16
 121#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
 122
 123#endif  /* _SS_AVTAB_H_ */
 124
 125