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 "security.h"
  27 #include <linux/flex_array.h>
  28
  29 struct 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  */
  57 struct 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
  73 struct avtab_datum {
  74         union {
  75                 u32 data; /* access vector or type value */
  76                 struct avtab_extended_perms *xperms;
  77         } u;
  78 };
  79
  80 struct avtab_node {
  81         struct avtab_key key;
  82         struct avtab_datum datum;
  83         struct avtab_node *next;
  84 };
  85
  86 struct 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
  94 int avtab_init(struct avtab *);
  95 int avtab_alloc(struct avtab *, u32);
  96 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
  97 void avtab_destroy(struct avtab *h);
  98 void avtab_hash_eval(struct avtab *h, char *tag);
  99
 100 struct policydb;
 101 int 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
 106 int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
 107 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
 108 int avtab_write(struct policydb *p, struct avtab *a, void *fp);
 109
 110 struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
 111                                           struct avtab_datum *datum);
 112
 113 struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);
 114
 115 struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);
 116
 117 void avtab_cache_init(void);
 118 void 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