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, or new object type */
  76         u32 tclass;             /* process class, or new object class */
  77         u32 new_role;           /* new role */
  78         struct role_trans *next;
  79 };
  80
  81 struct filename_trans {
  82         u32 stype;              /* current process */
  83         u32 ttype;              /* parent dir context */
  84         u16 tclass;             /* class of new object */
  85         const char *name;       /* last path component */
  86 };
  87
  88 struct filename_trans_datum {
  89         u32 otype;              /* expected of new object */
  90 };
  91
  92 struct role_allow {
  93         u32 role;               /* current role */
  94         u32 new_role;           /* new role */
  95         struct role_allow *next;
  96 };
  97
  98 /* Type attributes */
  99 struct type_datum {
 100         u32 value;              /* internal type value */
 101         u32 bounds;             /* boundary of type */
 102         unsigned char primary;  /* primary name? */
 103         unsigned char attribute;/* attribute ?*/
 104 };
 105
 106 /* User attributes */
 107 struct user_datum {
 108         u32 value;                      /* internal user value */
 109         u32 bounds;                     /* bounds of user */
 110         struct ebitmap roles;           /* set of authorized roles for user */
 111         struct mls_range range;         /* MLS range (min - max) for user */
 112         struct mls_level dfltlevel;     /* default login MLS level for user */
 113 };
 114
 115
 116 /* Sensitivity attributes */
 117 struct level_datum {
 118         struct mls_level *level;        /* sensitivity and associated categories */
 119         unsigned char isalias;  /* is this sensitivity an alias for another? */
 120 };
 121
 122 /* Category attributes */
 123 struct cat_datum {
 124         u32 value;              /* internal category bit + 1 */
 125         unsigned char isalias;  /* is this category an alias for another? */
 126 };
 127
 128 struct range_trans {
 129         u32 source_type;
 130         u32 target_type;
 131         u32 target_class;
 132 };
 133
 134 /* Boolean data type */
 135 struct cond_bool_datum {
 136         __u32 value;            /* internal type value */
 137         int state;
 138 };
 139
 140 struct cond_node;
 141
 142 /*
 143  * The configuration data includes security contexts for
 144  * initial SIDs, unlabeled file systems, TCP and UDP port numbers,
 145  * network interfaces, and nodes.  This structure stores the
 146  * relevant data for one such entry.  Entries of the same kind
 147  * (e.g. all initial SIDs) are linked together into a list.
 148  */
 149 struct ocontext {
 150         union {
 151                 char *name;     /* name of initial SID, fs, netif, fstype, path */
 152                 struct {
 153                         u8 protocol;
 154                         u16 low_port;
 155                         u16 high_port;
 156                 } port;         /* TCP or UDP port information */
 157                 struct {
 158                         u32 addr;
 159                         u32 mask;
 160                 } node;         /* node information */
 161                 struct {
 162                         u32 addr[4];
 163                         u32 mask[4];
 164                 } node6;        /* IPv6 node information */
 165         } u;
 166         union {
 167                 u32 sclass;  /* security class for genfs */
 168                 u32 behavior;  /* labeling behavior for fs_use */
 169         } v;
 170         struct context context[2];      /* security context(s) */
 171         u32 sid[2];     /* SID(s) */
 172         struct ocontext *next;
 173 };
 174
 175 struct genfs {
 176         char *fstype;
 177         struct ocontext *head;
 178         struct genfs *next;
 179 };
 180
 181 /* symbol table array indices */
 182 #define SYM_COMMONS 0
 183 #define SYM_CLASSES 1
 184 #define SYM_ROLES   2
 185 #define SYM_TYPES   3
 186 #define SYM_USERS   4
 187 #define SYM_BOOLS   5
 188 #define SYM_LEVELS  6
 189 #define SYM_CATS    7
 190 #define SYM_NUM     8
 191
 192 /* object context array indices */
 193 #define OCON_ISID  0    /* initial SIDs */
 194 #define OCON_FS    1    /* unlabeled file systems */
 195 #define OCON_PORT  2    /* TCP and UDP port numbers */
 196 #define OCON_NETIF 3    /* network interfaces */
 197 #define OCON_NODE  4    /* nodes */
 198 #define OCON_FSUSE 5    /* fs_use */
 199 #define OCON_NODE6 6    /* IPv6 nodes */
 200 #define OCON_NUM   7
 201
 202 /* The policy database */
 203 struct policydb {
 204         int mls_enabled;
 205
 206         /* symbol tables */
 207         struct symtab symtab[SYM_NUM];
 208 #define p_commons symtab[SYM_COMMONS]
 209 #define p_classes symtab[SYM_CLASSES]
 210 #define p_roles symtab[SYM_ROLES]
 211 #define p_types symtab[SYM_TYPES]
 212 #define p_users symtab[SYM_USERS]
 213 #define p_bools symtab[SYM_BOOLS]
 214 #define p_levels symtab[SYM_LEVELS]
 215 #define p_cats symtab[SYM_CATS]
 216
 217         /* symbol names indexed by (value - 1) */
 218         struct flex_array *sym_val_to_name[SYM_NUM];
 219
 220         /* class, role, and user attributes indexed by (value - 1) */
 221         struct class_datum **class_val_to_struct;
 222         struct role_datum **role_val_to_struct;
 223         struct user_datum **user_val_to_struct;
 224         struct flex_array *type_val_to_struct_array;
 225
 226         /* type enforcement access vectors and transitions */
 227         struct avtab te_avtab;
 228
 229         /* role transitions */
 230         struct role_trans *role_tr;
 231
 232         /* file transitions with the last path component */
 233         /* quickly exclude lookups when parent ttype has no rules */
 234         struct ebitmap filename_trans_ttypes;
 235         /* actual set of filename_trans rules */
 236         struct hashtab *filename_trans;
 237
 238         /* bools indexed by (value - 1) */
 239         struct cond_bool_datum **bool_val_to_struct;
 240         /* type enforcement conditional access vectors and transitions */
 241         struct avtab te_cond_avtab;
 242         /* linked list indexing te_cond_avtab by conditional */
 243         struct cond_node *cond_list;
 244
 245         /* role allows */
 246         struct role_allow *role_allow;
 247
 248         /* security contexts of initial SIDs, unlabeled file systems,
 249            TCP or UDP port numbers, network interfaces and nodes */
 250         struct ocontext *ocontexts[OCON_NUM];
 251
 252         /* security contexts for files in filesystems that cannot support
 253            a persistent label mapping or use another
 254            fixed labeling behavior. */
 255         struct genfs *genfs;
 256
 257         /* range transitions table (range_trans_key -> mls_range) */
 258         struct hashtab *range_tr;
 259
 260         /* type -> attribute reverse mapping */
 261         struct flex_array *type_attr_map_array;
 262
 263         struct ebitmap policycaps;
 264
 265         struct ebitmap permissive_map;
 266
 267         /* length of this policy when it was loaded */
 268         size_t len;
 269
 270         unsigned int policyvers;
 271
 272         unsigned int reject_unknown : 1;
 273         unsigned int allow_unknown : 1;
 274
 275         u16 process_class;
 276         u32 process_trans_perms;
 277 };
 278
 279 extern void policydb_destroy(struct policydb *p);
 280 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
 281 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
 282 extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
 283 extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
 284 extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
 285 extern int policydb_read(struct policydb *p, void *fp);
 286 extern int policydb_write(struct policydb *p, void *fp);
 287
 288 #define PERM_SYMTAB_SIZE 32
 289
 290 #define POLICYDB_CONFIG_MLS    1
 291
 292 /* the config flags related to unknown classes/perms are bits 2 and 3 */
 293 #define REJECT_UNKNOWN  0x00000002
 294 #define ALLOW_UNKNOWN   0x00000004
 295
 296 #define OBJECT_R "object_r"
 297 #define OBJECT_R_VAL 1
 298
 299 #define POLICYDB_MAGIC SELINUX_MAGIC
 300 #define POLICYDB_STRING "SE Linux"
 301
 302 struct policy_file {
 303         char *data;
 304         size_t len;
 305 };
 306
 307 struct policy_data {
 308         struct policydb *p;
 309         void *fp;
 310 };
 311
 312 static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
 313 {
 314         if (bytes > fp->len)
 315                 return -EINVAL;
 316
 317         memcpy(buf, fp->data, bytes);
 318         fp->data += bytes;
 319         fp->len -= bytes;
 320         return 0;
 321 }
 322
 323 static inline int put_entry(const void *buf, size_t bytes, int num, struct policy_file *fp)
 324 {
 325         size_t len = bytes * num;
 326
 327         memcpy(fp->data, buf, len);
 328         fp->data += len;
 329         fp->len -= len;
 330
 331         return 0;
 332 }
 333
 334 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
 335 {
 336         struct flex_array *fa = p->sym_val_to_name[sym_num];
 337
 338         return flex_array_get_ptr(fa, element_nr);
 339 }
 340
 341 extern u16 string_to_security_class(struct policydb *p, const char *name);
 342 extern u32 string_to_av_perm(struct policydb *p, u16 tclass, const char *name);
 343
 344 #endif  /* _SS_POLICYDB_H_ */
 345