security/selinux/ss/policydb.h

   1 /*
   2  * A policy database (policydb) specifies the
   3  * configuration data for the security policy.
   4  *
   5  * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
   6  */
   7
   8 /*
   9  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
  10  *
  11  *      Support for enhanced MLS infrastructure.
  12  *
  13  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  14  *
  15  *      Added conditional policy language extensions
  16  *
  17  * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  18  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  19  *      This program is free software; you can redistribute it and/or modify
  20  *      it under the terms of the GNU General Public License as published by
  21  *      the Free Software Foundation, version 2.
  22  */
  23
  24 #ifndef _SS_POLICYDB_H_
  25 #define _SS_POLICYDB_H_
  26
  27 #include <linux/flex_array.h>
  28
  29 #include "symtab.h"
  30 #include "avtab.h"
  31 #include "sidtab.h"
  32 #include "ebitmap.h"
  33 #include "mls_types.h"
  34 #include "context.h"
  35 #include "constraint.h"
  36
  37 /*
  38  * A datum type is defined for each kind of symbol
  39  * in the configuration data:  individual permissions,
  40  * common prefixes for access vectors, classes,
  41  * users, roles, types, sensitivities, categories, etc.
  42  */
  43
  44 /* Permission attributes */
  45 struct perm_datum {
  46         u32 value;              /* permission bit + 1 */
  47 };
  48
  49 /* Attributes of a common prefix for access vectors */
  50 struct common_datum {
  51         u32 value;                      /* internal common value */
  52         struct symtab permissions;      /* common permissions */
  53 };
  54
  55 /* Class attributes */
  56 struct class_datum {
  57         u32 value;                      /* class value */
  58         char *comkey;                   /* common name */
  59         struct common_datum *comdatum;  /* common datum */
  60         struct symtab permissions;      /* class-specific permission symbol table */
  61         struct constraint_node *constraints;    /* constraints on class permissions */
  62         struct constraint_node *validatetrans;  /* special transition rules */
  63 /* Options how a new object user, role, and type should be decided */
  64 #define DEFAULT_SOURCE         1
  65 #define DEFAULT_TARGET         2
  66         char default_user;
  67         char default_role;
  68         char default_type;
  69 /* Options how a new object range should be decided */
  70 #define DEFAULT_SOURCE_LOW     1
  71 #define DEFAULT_SOURCE_HIGH    2
  72 #define DEFAULT_SOURCE_LOW_HIGH        3
  73 #define DEFAULT_TARGET_LOW     4
  74 #define DEFAULT_TARGET_HIGH    5
  75 #define DEFAULT_TARGET_LOW_HIGH        6
  76         char default_range;
  77 };
  78
  79 /* Role attributes */
  80 struct role_datum {
  81         u32 value;                      /* internal role value */
  82         u32 bounds;                     /* boundary of role */
  83         struct ebitmap dominates;       /* set of roles dominated by this role */
  84         struct ebitmap types;           /* set of authorized types for role */
  85 };
  86
  87 struct role_trans {
  88         u32 role;               /* current role */
  89         u32 type;               /* program executable type, or new object type */
  90         u32 tclass;             /* process class, or new object class */
  91         u32 new_role;           /* new role */
  92         struct role_trans *next;
  93 };
  94
  95 struct filename_trans {
  96         u32 stype;              /* current process */
  97         u32 ttype;              /* parent dir context */
  98         u16 tclass;             /* class of new object */
  99         const char *name;       /* last path component */
 100 };
 101
 102 struct filename_trans_datum {
 103         u32 otype;              /* expected of new object */
 104 };
 105
 106 struct role_allow {
 107         u32 role;               /* current role */
 108         u32 new_role;           /* new role */
 109         struct role_allow *next;
 110 };
 111
 112 /* Type attributes */
 113 struct type_datum {
 114         u32 value;              /* internal type value */
 115         u32 bounds;             /* boundary of type */
 116         unsigned char primary;  /* primary name? */
 117         unsigned char attribute;/* attribute ?*/
 118 };
 119
 120 /* User attributes */
 121 struct user_datum {
 122         u32 value;                      /* internal user value */
 123         u32 bounds;                     /* bounds of user */
 124         struct ebitmap roles;           /* set of authorized roles for user */
 125         struct mls_range range;         /* MLS range (min - max) for user */
 126         struct mls_level dfltlevel;     /* default login MLS level for user */
 127 };
 128
 129
 130 /* Sensitivity attributes */
 131 struct level_datum {
 132         struct mls_level *level;        /* sensitivity and associated categories */
 133         unsigned char isalias;  /* is this sensitivity an alias for another? */
 134 };
 135
 136 /* Category attributes */
 137 struct cat_datum {
 138         u32 value;              /* internal category bit + 1 */
 139         unsigned char isalias;  /* is this category an alias for another? */
 140 };
 141
 142 struct range_trans {
 143         u32 source_type;
 144         u32 target_type;
 145         u32 target_class;
 146 };
 147
 148 /* Boolean data type */
 149 struct cond_bool_datum {
 150         __u32 value;            /* internal type value */
 151         int state;
 152 };
 153
 154 struct cond_node;
 155
 156 /*
 157  * type set preserves data needed to determine constraint info from
 158  * policy source. This is not used by the kernel policy but allows
 159  * utilities such as audit2allow to determine constraint denials.
 160  */
 161 struct type_set {
 162         struct ebitmap types;
 163         struct ebitmap negset;
 164         u32 flags;
 165 };
 166
 167 /*
 168  * The configuration data includes security contexts for
 169  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
 170  * network interfaces, and nodes.  This structure stores the
 171  * relevant data for one such entry.  Entries of the same kind
 172  * (e.g. all initial SIDs) are linked together into a list.
 173  */
 174 struct ocontext {
 175         union {
 176                 char *name;     /* name of initial SID, fs, netif, fstype, path */
 177                 struct {
 178                         u8 protocol;
 179                         u16 low_port;
 180                         u16 high_port;
 181                 } port;         /* TCP or UDP port information */
 182                 struct {
 183                         u32 addr;
 184                         u32 mask;
 185                 } node;         /* node information */
 186                 struct {
 187                         u32 addr[4];
 188                         u32 mask[4];
 189                 } node6;        /* IPv6 node information */
 190         } u;
 191         union {
 192                 u32 sclass;  /* security class for genfs */
 193                 u32 behavior;  /* labeling behavior for fs_use */
 194         } v;
 195         struct context context[2];      /* security context(s) */
 196         u32 sid[2];     /* SID(s) */
 197         struct ocontext *next;
 198 };
 199
 200 struct genfs {
 201         char *fstype;
 202         struct ocontext *head;
 203         struct genfs *next;
 204 };
 205
 206 /* symbol table array indices */
 207 #define SYM_COMMONS 0
 208 #define SYM_CLASSES 1
 209 #define SYM_ROLES   2
 210 #define SYM_TYPES   3
 211 #define SYM_USERS   4
 212 #define SYM_BOOLS   5
 213 #define SYM_LEVELS  6
 214 #define SYM_CATS    7
 215 #define SYM_NUM     8
 216
 217 /* object context array indices */
 218 #define OCON_ISID  0    /* initial SIDs */
 219 #define OCON_FS    1    /* unlabeled file systems */
 220 #define OCON_PORT  2    /* TCP and UDP port numbers */
 221 #define OCON_NETIF 3    /* network interfaces */
 222 #define OCON_NODE  4    /* nodes */
 223 #define OCON_FSUSE 5    /* fs_use */
 224 #define OCON_NODE6 6    /* IPv6 nodes */
 225 #define OCON_NUM   7
 226
 227 /* The policy database */
 228 struct policydb {
 229         int mls_enabled;
 230
 231         /* symbol tables */
 232         struct symtab symtab[SYM_NUM];
 233 #define p_commons symtab[SYM_COMMONS]
 234 #define p_classes symtab[SYM_CLASSES]
 235 #define p_roles symtab[SYM_ROLES]
 236 #define p_types symtab[SYM_TYPES]
 237 #define p_users symtab[SYM_USERS]
 238 #define p_bools symtab[SYM_BOOLS]
 239 #define p_levels symtab[SYM_LEVELS]
 240 #define p_cats symtab[SYM_CATS]
 241
 242         /* symbol names indexed by (value - 1) */
 243         struct flex_array *sym_val_to_name[SYM_NUM];
 244
 245         /* class, role, and user attributes indexed by (value - 1) */
 246         struct class_datum **class_val_to_struct;
 247         struct role_datum **role_val_to_struct;
 248         struct user_datum **user_val_to_struct;
 249         struct flex_array *type_val_to_struct_array;
 250
 251         /* type enforcement access vectors and transitions */
 252         struct avtab te_avtab;
 253
 254         /* role transitions */
 255         struct role_trans *role_tr;
 256
 257         /* file transitions with the last path component */
 258         /* quickly exclude lookups when parent ttype has no rules */
 259         struct ebitmap filename_trans_ttypes;
 260         /* actual set of filename_trans rules */
 261         struct hashtab *filename_trans;
 262
 263         /* bools indexed by (value - 1) */
 264         struct cond_bool_datum **bool_val_to_struct;
 265         /* type enforcement conditional access vectors and transitions */
 266         struct avtab te_cond_avtab;
 267         /* linked list indexing te_cond_avtab by conditional */
 268         struct cond_node *cond_list;
 269
 270         /* role allows */
 271         struct role_allow *role_allow;
 272
 273         /* security contexts of initial SIDs, unlabeled file systems,
 274            TCP or UDP port numbers, network interfaces and nodes */
 275         struct ocontext *ocontexts[OCON_NUM];
 276
 277         /* security contexts for files in filesystems that cannot support
 278            a persistent label mapping or use another
 279            fixed labeling behavior. */
 280         struct genfs *genfs;
 281
 282         /* range transitions table (range_trans_key -> mls_range) */
 283         struct hashtab *range_tr;
 284
 285         /* type -> attribute reverse mapping */
 286         struct flex_array *type_attr_map_array;
 287
 288         struct ebitmap policycaps;
 289
 290         struct ebitmap permissive_map;
 291
 292         /* length of this policy when it was loaded */
 293         size_t len;
 294
 295         unsigned int policyvers;
 296
 297         unsigned int reject_unknown : 1;
 298         unsigned int allow_unknown : 1;
 299
 300         u16 process_class;
 301         u32 process_trans_perms;
 302 };
 303
 304 extern void policydb_destroy(struct policydb *p);
 305 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
 306 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
 307 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
 308 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
 309 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
 310 extern int policydb_read(struct policydb *p, void *fp);
 311 extern int policydb_write(struct policydb *p, void *fp);
 312
 313 #define PERM_SYMTAB_SIZE 32
 314
 315 #define POLICYDB_CONFIG_MLS    1
 316
 317 /* the config flags related to unknown classes/perms are bits 2 and 3 */
 318 #define REJECT_UNKNOWN  0x00000002
 319 #define ALLOW_UNKNOWN   0x00000004
 320
 321 #define OBJECT_R "object_r"
 322 #define OBJECT_R_VAL 1
 323
 324 #define POLICYDB_MAGIC SELINUX_MAGIC
 325 #define POLICYDB_STRING "SE Linux"
 326
 327 struct policy_file {
 328         char *data;
 329         size_t len;
 330 };
 331
 332 struct policy_data {
 333         struct policydb *p;
 334         void *fp;
 335 };
 336
 337 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
 338 {
 339         if (bytes > fp->len)
 340                 return -EINVAL;
 341
 342         memcpy(buf, fp->data, bytes);
 343         fp->data += bytes;
 344         fp->len -= bytes;
 345         return 0;
 346 }
 347
 348 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
 349 {
 350         size_t len = bytes * num;
 351
 352         memcpy(fp->data, buf, len);
 353         fp->data += len;
 354         fp->len -= len;
 355
 356         return 0;
 357 }
 358
 359 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
 360 {
 361         struct flex_array *fa = p->sym_val_to_name[sym_num];
 362
 363         return flex_array_get_ptr(fa, element_nr);
 364 }
 365
 366 extern u16 string_to_security_class(struct policydb *p, const char *name);
 367 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
 368
 369 #endif  /* _SS_POLICYDB_H_ */
 370