policydb.h

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

/*
 * Updated: Trusted Computer Solutions, Inc. <[email protected]>
 *
 *  Support for enhanced MLS infrastructure.
 *
 * Updated: Frank Mayer <[email protected]> and Karl MacMillan <[email protected]>
 *
 *  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.
 */

#ifndef _SS_POLICYDB_H_
#define _SS_POLICYDB_H_

#include <linux/flex_array.h>

#include "symtab.h"
#include "avtab.h"
#include "sidtab.h"
#include "ebitmap.h"
#include "mls_types.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 */
/* Options how a new object user, role, and type should be decided */
#define DEFAULT_SOURCE         1
#define DEFAULT_TARGET         2
    char default_user;
    char default_role;
    char default_type;
/* Options how a new object range should be decided */
#define DEFAULT_SOURCE_LOW     1
#define DEFAULT_SOURCE_HIGH    2
#define DEFAULT_SOURCE_LOW_HIGH        3
#define DEFAULT_TARGET_LOW     4
#define DEFAULT_TARGET_HIGH    5
#define DEFAULT_TARGET_LOW_HIGH        6
    char default_range;
};

/* Role attributes */
struct role_datum {
    u32 value;          /* internal role value */
    u32 bounds;         /* boundary of role */
    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, or new object type */
    u32 tclass;     /* process class, or new object class */
    u32 new_role;       /* new role */
    struct role_trans *next;
};

struct filename_trans {
    u32 stype;      /* current process */
    u32 ttype;      /* parent dir context */
    u16 tclass;     /* class of new object */
    const char *name;   /* last path component */
};

struct filename_trans_datum {
    u32 otype;      /* expected of new object */
};

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 */
    u32 bounds;     /* boundary of type */
    unsigned char primary;  /* primary name? */
    unsigned char attribute;/* attribute ?*/
};

/* User attributes */
struct user_datum {
    u32 value;          /* internal user value */
    u32 bounds;         /* bounds of user */
    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 source_type;
    u32 target_type;
    u32 target_class;
};

/* 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 */
        struct {
            u8 protocol;
            u16 low_port;
            u16 high_port;
        } port;     /* TCP or UDP port information */
        struct {
            u32 addr;
            u32 mask;
        } node;     /* node information */
        struct {
            u32 addr[4];
            u32 mask[4];
        } node6;        /* IPv6 node information */
    } u;
    union {
        u32 sclass;  /* security class for genfs */
        u32 behavior;  /* labeling behavior for fs_use */
    } v;
    struct context context[2];  /* security context(s) */
    u32 sid[2]; /* SID(s) */
    struct ocontext *next;
};

struct genfs {
    char *fstype;
    struct ocontext *head;
    struct genfs *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_FS    1    /* unlabeled file systems */
#define OCON_PORT  2    /* TCP and UDP port numbers */
#define OCON_NETIF 3    /* network interfaces */
#define OCON_NODE  4    /* nodes */
#define OCON_FSUSE 5    /* fs_use */
#define OCON_NODE6 6    /* IPv6 nodes */
#define OCON_NUM   7

/* The policy database */
struct policydb {
    int mls_enabled;

    /* 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) */
    struct flex_array *sym_val_to_name[SYM_NUM];

    /* 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;
    struct flex_array *type_val_to_struct_array;

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

    /* role transitions */
    struct role_trans *role_tr;

    /* file transitions with the last path component */
    /* quickly exclude lookups when parent ttype has no rules */
    struct ebitmap filename_trans_ttypes;
    /* actual set of filename_trans rules */
    struct hashtab *filename_trans;

    /* 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];

    /* security contexts for files in filesystems that cannot support
       a persistent label mapping or use another
       fixed labeling behavior. */
    struct genfs *genfs;

    /* range transitions table (range_trans_key -> mls_range) */
    struct hashtab *range_tr;

    /* type -> attribute reverse mapping */
    struct flex_array *type_attr_map_array;

    struct ebitmap policycaps;

    struct ebitmap permissive_map;

    /* length of this policy when it was loaded */
    size_t len;

    unsigned int policyvers;

    unsigned int reject_unknown : 1;
    unsigned int allow_unknown : 1;

    u16 process_class;
    u32 process_trans_perms;
};

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_class_isvalid(struct policydb *p, unsigned int class);
extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
extern int policydb_read(struct policydb *p, void *fp);
extern int policydb_write(struct policydb *p, void *fp);

#define PERM_SYMTAB_SIZE 32

#define POLICYDB_CONFIG_MLS    1

/* the config flags related to unknown classes/perms are bits 2 and 3 */
#define REJECT_UNKNOWN  0x00000002
#define ALLOW_UNKNOWN   0x00000004

#define OBJECT_R "object_r"
#define OBJECT_R_VAL 1

#define POLICYDB_MAGIC SELINUX_MAGIC
#define POLICYDB_STRING "SE Linux"

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

struct policy_data {
    struct policydb *p;
    void *fp;
};

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;
}

static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
{
    size_t len = bytes * num;

    memcpy(fp->data, buf, len);
    fp->data += len;
    fp->len -= len;

    return 0;
}

static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
{
    struct flex_array *fa = p->sym_val_to_name[sym_num];

    return flex_array_get_ptr(fa, element_nr);
}

extern u16 string_to_security_class(struct policydb *p, const char *name);
extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);

#endif  /* _SS_POLICYDB_H_ */