/*
 * A policy database (policydb) specifies the
 * configuration data for the security policy.
 *
 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
 */

/*
 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
 *
 *      Support for enhanced MLS infrastructure.
 *
 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
 *
 *      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;

/*
 * type set preserves data needed to determine constraint info from
 * policy source. This is not used by the kernel policy but allows
 * utilities such as audit2allow to determine constraint denials.
 */
struct type_set {
        struct ebitmap types;
        struct ebitmap negset;
        u32 flags;
};

/*
 * 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_ */