avtab.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * An access vector table (avtab) is a hash table
  4 * of access vectors and transition types indexed
  5 * by a type pair and a class.  An access vector
  6 * table is used to represent the type enforcement
  7 * tables.
  8 *
  9 *  Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
 10 */
 11
 12/* Updated: Frank Mayer <mayerf@tresys.com> and
 13 *          Karl MacMillan <kmacmillan@tresys.com>
 14 *          Added conditional policy language extensions
 15 *          Copyright (C) 2003 Tresys Technology, LLC
 16 *
 17 * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
 18 *          Tuned number of hash slots for avtab to reduce memory usage
 19 */
 20
 21#ifndef _SS_AVTAB_H_
 22#define _SS_AVTAB_H_
 23
 24#include "security.h"
 25
 26struct 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	 0x0001
 31#define AVTAB_AUDITALLOW 0x0002
 32#define AVTAB_AUDITDENY	 0x0004
 33#define AVTAB_AV	 (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
 34#define AVTAB_TRANSITION 0x0010
 35#define AVTAB_MEMBER	 0x0020
 36#define AVTAB_CHANGE	 0x0040
 37#define AVTAB_TYPE	 (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
 38/* extended permissions */
 39#define AVTAB_XPERMS_ALLOWED	0x0100
 40#define AVTAB_XPERMS_AUDITALLOW 0x0200
 41#define AVTAB_XPERMS_DONTAUDIT	0x0400
 42#define AVTAB_XPERMS                                      \
 43	(AVTAB_XPERMS_ALLOWED | AVTAB_XPERMS_AUDITALLOW | \
 44	 AVTAB_XPERMS_DONTAUDIT)
 45#define AVTAB_ENABLED_OLD 0x80000000 /* reserved for used in cond_avtab */
 46#define AVTAB_ENABLED	  0x8000 /* reserved for used in cond_avtab */
 47	u16 specified; /* what field is specified */
 48};
 49
 50/*
 51 * For operations that require more than the 32 permissions provided by the avc
 52 * extended permissions may be used to provide 256 bits of permissions.
 53 */
 54struct avtab_extended_perms {
 55/* These are not flags. All 256 values may be used */
 56#define AVTAB_XPERMS_IOCTLFUNCTION	0x01
 57#define AVTAB_XPERMS_IOCTLDRIVER	0x02
 58#define AVTAB_XPERMS_NLMSG		0x03
 59	/* extension of the avtab_key specified */
 60	u8 specified; /* ioctl, netfilter, ... */
 61	/*
 62	 * if 256 bits is not adequate as is often the case with ioctls, then
 63	 * multiple extended perms may be used and the driver field
 64	 * specifies which permissions are included.
 65	 */
 66	u8 driver;
 67	/* 256 bits of permissions */
 68	struct extended_perms_data perms;
 69};
 70
 71struct avtab_datum {
 72	union {
 73		u32 data; /* access vector or type value */
 74		struct avtab_extended_perms *xperms;
 75	} u;
 76};
 77
 78struct avtab_node {
 79	struct avtab_key key;
 80	struct avtab_datum datum;
 81	struct avtab_node *next;
 82};
 83
 84struct avtab {
 85	struct avtab_node **htable;
 86	u32 nel; /* number of elements */
 87	u32 nslot; /* number of hash slots */
 88	u32 mask; /* mask to compute hash func */
 89};
 90
 91void avtab_init(struct avtab *h);
 92int avtab_alloc(struct avtab *h, u32 nrules);
 93int avtab_alloc_dup(struct avtab *new, const struct avtab *orig);
 94void avtab_destroy(struct avtab *h);
 95
 96#define MAX_AVTAB_HASH_BITS    16
 97#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)
 98
 99#ifdef CONFIG_SECURITY_SELINUX_DEBUG
100void avtab_hash_eval(struct avtab *h, const char *tag);
101#else
102static inline void avtab_hash_eval(struct avtab *h, const char *tag)
103{
104}
105#endif
106
107struct policydb;
108struct policy_file;
109int avtab_read_item(struct avtab *a, struct policy_file *fp, struct policydb *pol,
110		    int (*insert)(struct avtab *a, const struct avtab_key *k,
111				  const struct avtab_datum *d, void *p),
112		    void *p, bool conditional);
113
114int avtab_read(struct avtab *a, struct policy_file *fp, struct policydb *pol);
115int avtab_write_item(struct policydb *p, const struct avtab_node *cur,
116		     struct policy_file *fp);
117int avtab_write(struct policydb *p, struct avtab *a, struct policy_file *fp);
118
119struct avtab_node *avtab_insert_nonunique(struct avtab *h,
120					  const struct avtab_key *key,
121					  const struct avtab_datum *datum);
122
123struct avtab_node *avtab_search_node(struct avtab *h,
124				     const struct avtab_key *key);
125struct avtab_node *avtab_search_node_next(struct avtab_node *node,
126					  u16 specified);
127
128#endif /* _SS_AVTAB_H_ */