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 };
  64
  65 /* Role attributes */
  66 struct role_datum {
  67         u32 value;                      /* internal role value */
  68         u32 bounds;                     /* boundary of role */
  69         struct ebitmap dominates;       /* set of roles dominated by this role */
  70         struct ebitmap types;           /* set of authorized types for role */
  71 };
  72
  73 struct role_trans {
  74         u32 role;               /* current role */
  75         u32 type;               /* program executable type */
  76         u32 new_role;           /* new role */
  77         struct role_trans *next;
  78 };
  79
  80 struct role_allow {
  81         u32 role;               /* current role */
  82         u32 new_role;           /* new role */
  83         struct role_allow *next;
  84 };
  85
  86 /* Type attributes */
  87 struct type_datum {
  88         u32 value;              /* internal type value */
  89         u32 bounds;             /* boundary of type */
  90         unsigned char primary;  /* primary name? */
  91         unsigned char attribute;/* attribute ?*/
  92 };
  93
  94 /* User attributes */
  95 struct user_datum {
  96         u32 value;                      /* internal user value */
  97         u32 bounds;                     /* bounds of user */
  98         struct ebitmap roles;           /* set of authorized roles for user */
  99         struct mls_range range;         /* MLS range (min - max) for user */
 100         struct mls_level dfltlevel;     /* default login MLS level for user */
 101 };
 102
 103
 104 /* Sensitivity attributes */
 105 struct level_datum {
 106         struct mls_level *level;        /* sensitivity and associated categories */
 107         unsigned char isalias;  /* is this sensitivity an alias for another? */
 108 };
 109
 110 /* Category attributes */
 111 struct cat_datum {
 112         u32 value;              /* internal category bit + 1 */
 113         unsigned char isalias;  /* is this category an alias for another? */
 114 };
 115
 116 struct range_trans {
 117         u32 source_type;
 118         u32 target_type;
 119         u32 target_class;
 120 };
 121
 122 /* Boolean data type */
 123 struct cond_bool_datum {
 124         __u32 value;            /* internal type value */
 125         int state;
 126 };
 127
 128 struct cond_node;
 129
 130 /*
 131  * The configuration data includes security contexts for
 132  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
 133  * network interfaces, and nodes.  This structure stores the
 134  * relevant data for one such entry.  Entries of the same kind
 135  * (e.g. all initial SIDs) are linked together into a list.
 136  */
 137 struct ocontext {
 138         union {
 139                 char *name;     /* name of initial SID, fs, netif, fstype, path */
 140                 struct {
 141                         u8 protocol;
 142                         u16 low_port;
 143                         u16 high_port;
 144                 } port;         /* TCP or UDP port information */
 145                 struct {
 146                         u32 addr;
 147                         u32 mask;
 148                 } node;         /* node information */
 149                 struct {
 150                         u32 addr[4];
 151                         u32 mask[4];
 152                 } node6;        /* IPv6 node information */
 153         } u;
 154         union {
 155                 u32 sclass;  /* security class for genfs */
 156                 u32 behavior;  /* labeling behavior for fs_use */
 157         } v;
 158         struct context context[2];      /* security context(s) */
 159         u32 sid[2];     /* SID(s) */
 160         struct ocontext *next;
 161 };
 162
 163 struct genfs {
 164         char *fstype;
 165         struct ocontext *head;
 166         struct genfs *next;
 167 };
 168
 169 /* symbol table array indices */
 170 #define SYM_COMMONS 0
 171 #define SYM_CLASSES 1
 172 #define SYM_ROLES   2
 173 #define SYM_TYPES   3
 174 #define SYM_USERS   4
 175 #define SYM_BOOLS   5
 176 #define SYM_LEVELS  6
 177 #define SYM_CATS    7
 178 #define SYM_NUM     8
 179
 180 /* object context array indices */
 181 #define OCON_ISID  0    /* initial SIDs */
 182 #define OCON_FS    1    /* unlabeled file systems */
 183 #define OCON_PORT  2    /* TCP and UDP port numbers */
 184 #define OCON_NETIF 3    /* network interfaces */
 185 #define OCON_NODE  4    /* nodes */
 186 #define OCON_FSUSE 5    /* fs_use */
 187 #define OCON_NODE6 6    /* IPv6 nodes */
 188 #define OCON_NUM   7
 189
 190 /* The policy database */
 191 struct policydb {
 192         int mls_enabled;
 193
 194         /* symbol tables */
 195         struct symtab symtab[SYM_NUM];
 196 #define p_commons symtab[SYM_COMMONS]
 197 #define p_classes symtab[SYM_CLASSES]
 198 #define p_roles symtab[SYM_ROLES]
 199 #define p_types symtab[SYM_TYPES]
 200 #define p_users symtab[SYM_USERS]
 201 #define p_bools symtab[SYM_BOOLS]
 202 #define p_levels symtab[SYM_LEVELS]
 203 #define p_cats symtab[SYM_CATS]
 204
 205         /* symbol names indexed by (value - 1) */
 206         struct flex_array *sym_val_to_name[SYM_NUM];
 207
 208         /* class, role, and user attributes indexed by (value - 1) */
 209         struct class_datum **class_val_to_struct;
 210         struct role_datum **role_val_to_struct;
 211         struct user_datum **user_val_to_struct;
 212         struct flex_array *type_val_to_struct_array;
 213
 214         /* type enforcement access vectors and transitions */
 215         struct avtab te_avtab;
 216
 217         /* role transitions */
 218         struct role_trans *role_tr;
 219
 220         /* bools indexed by (value - 1) */
 221         struct cond_bool_datum **bool_val_to_struct;
 222         /* type enforcement conditional access vectors and transitions */
 223         struct avtab te_cond_avtab;
 224         /* linked list indexing te_cond_avtab by conditional */
 225         struct cond_node *cond_list;
 226
 227         /* role allows */
 228         struct role_allow *role_allow;
 229
 230         /* security contexts of initial SIDs, unlabeled file systems,
 231            TCP or UDP port numbers, network interfaces and nodes */
 232         struct ocontext *ocontexts[OCON_NUM];
 233
 234         /* security contexts for files in filesystems that cannot support
 235            a persistent label mapping or use another
 236            fixed labeling behavior. */
 237         struct genfs *genfs;
 238
 239         /* range transitions table (range_trans_key -> mls_range) */
 240         struct hashtab *range_tr;
 241
 242         /* type -> attribute reverse mapping */
 243         struct flex_array *type_attr_map_array;
 244
 245         struct ebitmap policycaps;
 246
 247         struct ebitmap permissive_map;
 248
 249         /* length of this policy when it was loaded */
 250         size_t len;
 251
 252         unsigned int policyvers;
 253
 254         unsigned int reject_unknown : 1;
 255         unsigned int allow_unknown : 1;
 256
 257         u16 process_class;
 258         u32 process_trans_perms;
 259 };
 260
 261 extern void policydb_destroy(struct policydb *p);
 262 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
 263 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
 264 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
 265 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
 266 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
 267 extern int policydb_read(struct policydb *p, void *fp);
 268 extern int policydb_write(struct policydb *p, void *fp);
 269
 270 #define PERM_SYMTAB_SIZE 32
 271
 272 #define POLICYDB_CONFIG_MLS    1
 273
 274 /* the config flags related to unknown classes/perms are bits 2 and 3 */
 275 #define REJECT_UNKNOWN  0x00000002
 276 #define ALLOW_UNKNOWN   0x00000004
 277
 278 #define OBJECT_R "object_r"
 279 #define OBJECT_R_VAL 1
 280
 281 #define POLICYDB_MAGIC SELINUX_MAGIC
 282 #define POLICYDB_STRING "SE Linux"
 283
 284 struct policy_file {
 285         char *data;
 286         size_t len;
 287 };
 288
 289 struct policy_data {
 290         struct policydb *p;
 291         void *fp;
 292 };
 293
 294 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
 295 {
 296         if (bytes > fp->len)
 297                 return -EINVAL;
 298
 299         memcpy(buf, fp->data, bytes);
 300         fp->data += bytes;
 301         fp->len -= bytes;
 302         return 0;
 303 }
 304
 305 static inline int put_entry(void *buf, size_t bytes, int num, struct policy_file *fp)
 306 {
 307         size_t len = bytes * num;
 308
 309         memcpy(fp->data, buf, len);
 310         fp->data += len;
 311         fp->len -= len;
 312
 313         return 0;
 314 }
 315
 316 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
 317 {
 318         struct flex_array *fa = p->sym_val_to_name[sym_num];
 319
 320         return flex_array_get_ptr(fa, element_nr);
 321 }
 322
 323 extern u16 string_to_security_class(struct policydb *p, const char *name);
 324 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
 325
 326 #endif  /* _SS_POLICYDB_H_ */
 327