avtab.h

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/*
 * An access vector table (avtab) is a hash table
 * of access vectors and transition types indexed
 * by a type pair and a class.  An access vector
 * table is used to represent the type enforcement
 * tables.
 *
 *  Author : Stephen Smalley, <[email protected]>
 */

/* Updated: Frank Mayer <[email protected]> and Karl MacMillan <[email protected]>
 *
 *  Added conditional policy language extensions
 *
 * Copyright (C) 2003 Tresys Technology, LLC
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, version 2.
 *
 * Updated: Yuichi Nakamura <[email protected]>
 *  Tuned number of hash slots for avtab to reduce memory usage
 */
#ifndef _SS_AVTAB_H_
#define _SS_AVTAB_H_

struct avtab_key {
    u16 source_type;    /* source type */
    u16 target_type;    /* target type */
    u16 target_class;   /* target object class */
#define AVTAB_ALLOWED       0x0001
#define AVTAB_AUDITALLOW    0x0002
#define AVTAB_AUDITDENY     0x0004
#define AVTAB_AV        (AVTAB_ALLOWED | AVTAB_AUDITALLOW | AVTAB_AUDITDENY)
#define AVTAB_TRANSITION    0x0010
#define AVTAB_MEMBER        0x0020
#define AVTAB_CHANGE        0x0040
#define AVTAB_TYPE      (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE)
#define AVTAB_ENABLED_OLD   0x80000000 /* reserved for used in cond_avtab */
#define AVTAB_ENABLED       0x8000 /* reserved for used in cond_avtab */
    u16 specified;  /* what field is specified */
};

struct avtab_datum {
    u32 data; /* access vector or type value */
};

struct avtab_node {
    struct avtab_key key;
    struct avtab_datum datum;
    struct avtab_node *next;
};

struct avtab {
    struct avtab_node **htable;
    u32 nel;    /* number of elements */
    u32 nslot;      /* number of hash slots */
    u16 mask;       /* mask to compute hash func */

};

int avtab_init(struct avtab *);
int avtab_alloc(struct avtab *, u32);
struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *k);
void avtab_destroy(struct avtab *h);
void avtab_hash_eval(struct avtab *h, char *tag);

struct policydb;
int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
            int (*insert)(struct avtab *a, struct avtab_key *k,
                  struct avtab_datum *d, void *p),
            void *p);

int avtab_read(struct avtab *a, void *fp, struct policydb *pol);
int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp);
int avtab_write(struct policydb *p, struct avtab *a, void *fp);

struct avtab_node *avtab_insert_nonunique(struct avtab *h, struct avtab_key *key,
                      struct avtab_datum *datum);

struct avtab_node *avtab_search_node(struct avtab *h, struct avtab_key *key);

struct avtab_node *avtab_search_node_next(struct avtab_node *node, int specified);

void avtab_cache_init(void);
void avtab_cache_destroy(void);

#define MAX_AVTAB_HASH_BITS 11
#define MAX_AVTAB_HASH_BUCKETS (1 << MAX_AVTAB_HASH_BITS)

#endif  /* _SS_AVTAB_H_ */