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