policydb.h

xen虚拟机源代码安装包

/*
 * A policy database (policydb) specifies the
 * configuration data for the security policy.
 *
 * Author : Stephen Smalley, <[e-mail]>
 */

/*
 * Updated: Trusted Computer Solutions, Inc. <[e-mail]>
 *
 *    Support for enhanced MLS infrastructure.
 *
 * Updated: Frank Mayer <[e-mail]> and Karl MacMillan <[e-mail]>
 *
 *     Added conditional policy language extensions
 *
 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
 * Copyright (C) 2003 - 2004 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.
 */

/* Ported to Xen 3.0, George Coker, <[e-mail]> */

#ifndef _SS_POLICYDB_H_
#define _SS_POLICYDB_H_

#include "symtab.h"
#include "avtab.h"
#include "sidtab.h"
#include "context.h"
#include "constraint.h"

/*
 * A datum type is defined for each kind of symbol
 * in the configuration data:  individual permissions,
 * common prefixes for access vectors, classes,
 * users, roles, types, sensitivities, categories, etc.
 */

/* Permission attributes */
struct perm_datum {
    u32 value;        /* permission bit + 1 */
};

/* Attributes of a common prefix for access vectors */
struct common_datum {
    u32 value;            /* internal common value */
    struct symtab permissions;    /* common permissions */
};

/* Class attributes */
struct class_datum {
    u32 value;            /* class value */
    char *comkey;            /* common name */
    struct common_datum *comdatum;    /* common datum */
    struct symtab permissions;    /* class-specific permission symbol table */
    struct constraint_node *constraints;    /* constraints on class permissions */
    struct constraint_node *validatetrans;    /* special transition rules */
};

/* Role attributes */
struct role_datum {
    u32 value;            /* internal role value */
    struct ebitmap dominates;    /* set of roles dominated by this role */
    struct ebitmap types;        /* set of authorized types for role */
};

struct role_trans {
    u32 role;        /* current role */
    u32 type;        /* program executable type */
    u32 new_role;        /* new role */
    struct role_trans *next;
};

struct role_allow {
    u32 role;        /* current role */
    u32 new_role;        /* new role */
    struct role_allow *next;
};

/* Type attributes */
struct type_datum {
    u32 value;        /* internal type value */
    unsigned char primary;    /* primary name? */
};

/* User attributes */
struct user_datum {
    u32 value;            /* internal user value */
    struct ebitmap roles;        /* set of authorized roles for user */
    struct mls_range range;        /* MLS range (min - max) for user */
    struct mls_level dfltlevel;    /* default login MLS level for user */
};


/* Sensitivity attributes */
struct level_datum {
    struct mls_level *level;    /* sensitivity and associated categories */
    unsigned char isalias;    /* is this sensitivity an alias for another? */
};

/* Category attributes */
struct cat_datum {
    u32 value;        /* internal category bit + 1 */
    unsigned char isalias;  /* is this category an alias for another? */
};

struct range_trans {
    u32 dom;            /* current process domain */
    u32 type;            /* program executable type */
    struct mls_range range;        /* new range */
    struct range_trans *next;
};

/* Boolean data type */
struct cond_bool_datum {
    __u32 value;        /* internal type value */
    int state;
};

struct cond_node;

/*
 * The configuration data includes security contexts for
 * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
 * network interfaces, and nodes.  This structure stores the
 * relevant data for one such entry.  Entries of the same kind
 * (e.g. all initial SIDs) are linked together into a list.
 */
struct ocontext {
    union {
        char *name;    /* name of initial SID, fs, netif, fstype, path */
        int pirq;
        int virq;
        int vcpu;
        u32 ioport;
        unsigned long iomem;
    } u;
    struct context context[2];    /* security context(s) */
    u32 sid[2];    /* SID(s) */
    struct ocontext *next;
};

/* symbol table array indices */
#define SYM_COMMONS 0
#define SYM_CLASSES 1
#define SYM_ROLES   2
#define SYM_TYPES   3
#define SYM_USERS   4
#define SYM_BOOLS   5
#define SYM_LEVELS  6
#define SYM_CATS    7
#define SYM_NUM     8

/* object context array indices */
#define OCON_ISID    0    /* initial SIDs */
#define OCON_PIRQ    1    /* physical irqs */
#define OCON_VIRQ    2    /* virtual irqs */
#define OCON_VCPU    3    /* virtual cpus */
#define OCON_IOPORT  4    /* io ports */
#define OCON_IOMEM   5    /* io memory */
#define OCON_DUMMY   6
#define OCON_NUM     7

/* The policy database */
struct policydb {
    /* symbol tables */
    struct symtab symtab[SYM_NUM];
#define p_commons symtab[SYM_COMMONS]
#define p_classes symtab[SYM_CLASSES]
#define p_roles symtab[SYM_ROLES]
#define p_types symtab[SYM_TYPES]
#define p_users symtab[SYM_USERS]
#define p_bools symtab[SYM_BOOLS]
#define p_levels symtab[SYM_LEVELS]
#define p_cats symtab[SYM_CATS]

    /* symbol names indexed by (value - 1) */
    char **sym_val_to_name[SYM_NUM];
#define p_common_val_to_name sym_val_to_name[SYM_COMMONS]
#define p_class_val_to_name sym_val_to_name[SYM_CLASSES]
#define p_role_val_to_name sym_val_to_name[SYM_ROLES]
#define p_type_val_to_name sym_val_to_name[SYM_TYPES]
#define p_user_val_to_name sym_val_to_name[SYM_USERS]
#define p_bool_val_to_name sym_val_to_name[SYM_BOOLS]
#define p_sens_val_to_name sym_val_to_name[SYM_LEVELS]
#define p_cat_val_to_name sym_val_to_name[SYM_CATS]

    /* class, role, and user attributes indexed by (value - 1) */
    struct class_datum **class_val_to_struct;
    struct role_datum **role_val_to_struct;
    struct user_datum **user_val_to_struct;

    /* type enforcement access vectors and transitions */
    struct avtab te_avtab;

    /* role transitions */
    struct role_trans *role_tr;

    /* bools indexed by (value - 1) */
    struct cond_bool_datum **bool_val_to_struct;
    /* type enforcement conditional access vectors and transitions */
    struct avtab te_cond_avtab;
    /* linked list indexing te_cond_avtab by conditional */
    struct cond_node* cond_list;

    /* role allows */
    struct role_allow *role_allow;

    /* security contexts of initial SIDs, unlabeled file systems,
       TCP or UDP port numbers, network interfaces and nodes */
    struct ocontext *ocontexts[OCON_NUM];

    /* range transitions */
    struct range_trans *range_tr;

    /* type -> attribute reverse mapping */
    struct ebitmap *type_attr_map;

    unsigned int policyvers;
};

extern void policydb_destroy(struct policydb *p);
extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
extern int policydb_context_isvalid(struct policydb *p, struct context *c);
extern int policydb_read(struct policydb *p, void *fp);

#define PERM_SYMTAB_SIZE 32

#define POLICYDB_CONFIG_MLS    1

#define OBJECT_R "object_r"
#define OBJECT_R_VAL 1

#define POLICYDB_MAGIC FLASK_MAGIC
#define POLICYDB_STRING "SE Linux"

struct policy_file {
    char *data;
    size_t len;
};

static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
{
    if ( bytes > fp->len )
        return -EINVAL;

    memcpy(buf, fp->data, bytes);
    fp->data += bytes;
    fp->len -= bytes;
    return 0;
}

#endif    /* _SS_POLICYDB_H_ */