include/linux/capability.h

   1 /*
   2  * This is <linux/capability.h>
   3  *
   4  * Andrew G. Morgan <morgan@kernel.org>
   5  * Alexander Kjeldaas <astor@guardian.no>
   6  * with help from Aleph1, Roland Buresund and Andrew Main.
   7  *
   8  * See here for the libcap library ("POSIX draft" compliance):
   9  *
  10  * ftp://linux.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/
  11  */
  12
  13 #ifndef _LINUX_CAPABILITY_H
  14 #define _LINUX_CAPABILITY_H
  15
  16 #include <linux/types.h>
  17
  18 struct task_struct;
  19
  20 /* User-level do most of the mapping between kernel and user
  21    capabilities based on the version tag given by the kernel. The
  22    kernel might be somewhat backwards compatible, but don't bet on
  23    it. */
  24
  25 /* Note, cap_t, is defined by POSIX (draft) to be an "opaque" pointer to
  26    a set of three capability sets.  The transposition of 3*the
  27    following structure to such a composite is better handled in a user
  28    library since the draft standard requires the use of malloc/free
  29    etc.. */
  30
  31 #define _LINUX_CAPABILITY_VERSION_1  0x19980330
  32 #define _LINUX_CAPABILITY_U32S_1     1
  33
  34 #define _LINUX_CAPABILITY_VERSION_2  0x20071026
  35 #define _LINUX_CAPABILITY_U32S_2     2
  36
  37 #define _LINUX_CAPABILITY_VERSION    _LINUX_CAPABILITY_VERSION_2
  38 #define _LINUX_CAPABILITY_U32S       _LINUX_CAPABILITY_U32S_2
  39
  40 typedef struct __user_cap_header_struct {
  41         __u32 version;
  42         int pid;
  43 } __user *cap_user_header_t;
  44
  45 typedef struct __user_cap_data_struct {
  46         __u32 effective;
  47         __u32 permitted;
  48         __u32 inheritable;
  49 } __user *cap_user_data_t;
  50
  51
  52 #define XATTR_CAPS_SUFFIX "capability"
  53 #define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX
  54
  55 #define VFS_CAP_REVISION_MASK   0xFF000000
  56 #define VFS_CAP_FLAGS_MASK      ~VFS_CAP_REVISION_MASK
  57 #define VFS_CAP_FLAGS_EFFECTIVE 0x000001
  58
  59 #define VFS_CAP_REVISION_1      0x01000000
  60 #define VFS_CAP_U32_1           1
  61 #define XATTR_CAPS_SZ_1         (sizeof(__le32)*(1 + 2*VFS_CAP_U32_1))
  62
  63 #define VFS_CAP_REVISION_2      0x02000000
  64 #define VFS_CAP_U32_2           2
  65 #define XATTR_CAPS_SZ_2         (sizeof(__le32)*(1 + 2*VFS_CAP_U32_2))
  66
  67 #define XATTR_CAPS_SZ           XATTR_CAPS_SZ_2
  68 #define VFS_CAP_U32             VFS_CAP_U32_2
  69 #define VFS_CAP_REVISION        VFS_CAP_REVISION_2
  70
  71
  72 struct vfs_cap_data {
  73         __le32 magic_etc;            /* Little endian */
  74         struct {
  75                 __le32 permitted;    /* Little endian */
  76                 __le32 inheritable;  /* Little endian */
  77         } data[VFS_CAP_U32];
  78 };
  79
  80 #ifdef __KERNEL__
  81
  82 typedef struct kernel_cap_struct {
  83         __u32 cap[_LINUX_CAPABILITY_U32S];
  84 } kernel_cap_t;
  85
  86 #define _USER_CAP_HEADER_SIZE  (sizeof(struct __user_cap_header_struct))
  87 #define _KERNEL_CAP_T_SIZE     (sizeof(kernel_cap_t))
  88
  89 #endif
  90
  91
  92 /**
  93  ** POSIX-draft defined capabilities.
  94  **/
  95
  96 /* In a system with the [_POSIX_CHOWN_RESTRICTED] option defined, this
  97    overrides the restriction of changing file ownership and group
  98    ownership. */
  99
 100 #define CAP_CHOWN            0
 101
 102 /* Override all DAC access, including ACL execute access if
 103    [_POSIX_ACL] is defined. Excluding DAC access covered by
 104    CAP_LINUX_IMMUTABLE. */
 105
 106 #define CAP_DAC_OVERRIDE     1
 107
 108 /* Overrides all DAC restrictions regarding read and search on files
 109    and directories, including ACL restrictions if [_POSIX_ACL] is
 110    defined. Excluding DAC access covered by CAP_LINUX_IMMUTABLE. */
 111
 112 #define CAP_DAC_READ_SEARCH  2
 113
 114 /* Overrides all restrictions about allowed operations on files, where
 115    file owner ID must be equal to the user ID, except where CAP_FSETID
 116    is applicable. It doesn't override MAC and DAC restrictions. */
 117
 118 #define CAP_FOWNER           3
 119
 120 /* Overrides the following restrictions that the effective user ID
 121    shall match the file owner ID when setting the S_ISUID and S_ISGID
 122    bits on that file; that the effective group ID (or one of the
 123    supplementary group IDs) shall match the file owner ID when setting
 124    the S_ISGID bit on that file; that the S_ISUID and S_ISGID bits are
 125    cleared on successful return from chown(2) (not implemented). */
 126
 127 #define CAP_FSETID           4
 128
 129 /* Overrides the restriction that the real or effective user ID of a
 130    process sending a signal must match the real or effective user ID
 131    of the process receiving the signal. */
 132
 133 #define CAP_KILL             5
 134
 135 /* Allows setgid(2) manipulation */
 136 /* Allows setgroups(2) */
 137 /* Allows forged gids on socket credentials passing. */
 138
 139 #define CAP_SETGID           6
 140
 141 /* Allows set*uid(2) manipulation (including fsuid). */
 142 /* Allows forged pids on socket credentials passing. */
 143
 144 #define CAP_SETUID           7
 145
 146
 147 /**
 148  ** Linux-specific capabilities
 149  **/
 150
 151 /* Without VFS support for capabilities:
 152  *   Transfer any capability in your permitted set to any pid,
 153  *   remove any capability in your permitted set from any pid
 154  * With VFS support for capabilities (neither of above, but)
 155  *   Add any capability to the current process' inheritable set
 156  */
 157
 158 #define CAP_SETPCAP          8
 159
 160 /* Allow modification of S_IMMUTABLE and S_APPEND file attributes */
 161
 162 #define CAP_LINUX_IMMUTABLE  9
 163
 164 /* Allows binding to TCP/UDP sockets below 1024 */
 165 /* Allows binding to ATM VCIs below 32 */
 166
 167 #define CAP_NET_BIND_SERVICE 10
 168
 169 /* Allow broadcasting, listen to multicast */
 170
 171 #define CAP_NET_BROADCAST    11
 172
 173 /* Allow interface configuration */
 174 /* Allow administration of IP firewall, masquerading and accounting */
 175 /* Allow setting debug option on sockets */
 176 /* Allow modification of routing tables */
 177 /* Allow setting arbitrary process / process group ownership on
 178    sockets */
 179 /* Allow binding to any address for transparent proxying */
 180 /* Allow setting TOS (type of service) */
 181 /* Allow setting promiscuous mode */
 182 /* Allow clearing driver statistics */
 183 /* Allow multicasting */
 184 /* Allow read/write of device-specific registers */
 185 /* Allow activation of ATM control sockets */
 186
 187 #define CAP_NET_ADMIN        12
 188
 189 /* Allow use of RAW sockets */
 190 /* Allow use of PACKET sockets */
 191
 192 #define CAP_NET_RAW          13
 193
 194 /* Allow locking of shared memory segments */
 195 /* Allow mlock and mlockall (which doesn't really have anything to do
 196    with IPC) */
 197
 198 #define CAP_IPC_LOCK         14
 199
 200 /* Override IPC ownership checks */
 201
 202 #define CAP_IPC_OWNER        15
 203
 204 /* Insert and remove kernel modules - modify kernel without limit */
 205 /* Modify cap_bset */
 206 #define CAP_SYS_MODULE       16
 207
 208 /* Allow ioperm/iopl access */
 209 /* Allow sending USB messages to any device via /proc/bus/usb */
 210
 211 #define CAP_SYS_RAWIO        17
 212
 213 /* Allow use of chroot() */
 214
 215 #define CAP_SYS_CHROOT       18
 216
 217 /* Allow ptrace() of any process */
 218
 219 #define CAP_SYS_PTRACE       19
 220
 221 /* Allow configuration of process accounting */
 222
 223 #define CAP_SYS_PACCT        20
 224
 225 /* Allow configuration of the secure attention key */
 226 /* Allow administration of the random device */
 227 /* Allow examination and configuration of disk quotas */
 228 /* Allow configuring the kernel's syslog (printk behaviour) */
 229 /* Allow setting the domainname */
 230 /* Allow setting the hostname */
 231 /* Allow calling bdflush() */
 232 /* Allow mount() and umount(), setting up new smb connection */
 233 /* Allow some autofs root ioctls */
 234 /* Allow nfsservctl */
 235 /* Allow VM86_REQUEST_IRQ */
 236 /* Allow to read/write pci config on alpha */
 237 /* Allow irix_prctl on mips (setstacksize) */
 238 /* Allow flushing all cache on m68k (sys_cacheflush) */
 239 /* Allow removing semaphores */
 240 /* Used instead of CAP_CHOWN to "chown" IPC message queues, semaphores
 241    and shared memory */
 242 /* Allow locking/unlocking of shared memory segment */
 243 /* Allow turning swap on/off */
 244 /* Allow forged pids on socket credentials passing */
 245 /* Allow setting readahead and flushing buffers on block devices */
 246 /* Allow setting geometry in floppy driver */
 247 /* Allow turning DMA on/off in xd driver */
 248 /* Allow administration of md devices (mostly the above, but some
 249    extra ioctls) */
 250 /* Allow tuning the ide driver */
 251 /* Allow access to the nvram device */
 252 /* Allow administration of apm_bios, serial and bttv (TV) device */
 253 /* Allow manufacturer commands in isdn CAPI support driver */
 254 /* Allow reading non-standardized portions of pci configuration space */
 255 /* Allow DDI debug ioctl on sbpcd driver */
 256 /* Allow setting up serial ports */
 257 /* Allow sending raw qic-117 commands */
 258 /* Allow enabling/disabling tagged queuing on SCSI controllers and sending
 259    arbitrary SCSI commands */
 260 /* Allow setting encryption key on loopback filesystem */
 261 /* Allow setting zone reclaim policy */
 262
 263 #define CAP_SYS_ADMIN        21
 264
 265 /* Allow use of reboot() */
 266
 267 #define CAP_SYS_BOOT         22
 268
 269 /* Allow raising priority and setting priority on other (different
 270    UID) processes */
 271 /* Allow use of FIFO and round-robin (realtime) scheduling on own
 272    processes and setting the scheduling algorithm used by another
 273    process. */
 274 /* Allow setting cpu affinity on other processes */
 275
 276 #define CAP_SYS_NICE         23
 277
 278 /* Override resource limits. Set resource limits. */
 279 /* Override quota limits. */
 280 /* Override reserved space on ext2 filesystem */
 281 /* Modify data journaling mode on ext3 filesystem (uses journaling
 282    resources) */
 283 /* NOTE: ext2 honors fsuid when checking for resource overrides, so
 284    you can override using fsuid too */
 285 /* Override size restrictions on IPC message queues */
 286 /* Allow more than 64hz interrupts from the real-time clock */
 287 /* Override max number of consoles on console allocation */
 288 /* Override max number of keymaps */
 289
 290 #define CAP_SYS_RESOURCE     24
 291
 292 /* Allow manipulation of system clock */
 293 /* Allow irix_stime on mips */
 294 /* Allow setting the real-time clock */
 295
 296 #define CAP_SYS_TIME         25
 297
 298 /* Allow configuration of tty devices */
 299 /* Allow vhangup() of tty */
 300
 301 #define CAP_SYS_TTY_CONFIG   26
 302
 303 /* Allow the privileged aspects of mknod() */
 304
 305 #define CAP_MKNOD            27
 306
 307 /* Allow taking of leases on files */
 308
 309 #define CAP_LEASE            28
 310
 311 #define CAP_AUDIT_WRITE      29
 312
 313 #define CAP_AUDIT_CONTROL    30
 314
 315 #define CAP_SETFCAP          31
 316
 317 /*
 318  * Bit location of each capability (used by user-space library and kernel)
 319  */
 320
 321 #define CAP_TO_INDEX(x)     ((x) >> 5)        /* 1 << 5 == bits in __u32 */
 322 #define CAP_TO_MASK(x)      (1 << ((x) & 31)) /* mask for indexed __u32 */
 323
 324 #ifdef __KERNEL__
 325
 326 /*
 327  * Internal kernel functions only
 328  */
 329
 330 #define CAP_FOR_EACH_U32(__capi)  \
 331         for (__capi = 0; __capi < _LINUX_CAPABILITY_U32S; ++__capi)
 332
 333 # define CAP_FS_MASK_B0     (CAP_TO_MASK(CAP_CHOWN)             \
 334                             | CAP_TO_MASK(CAP_DAC_OVERRIDE)     \
 335                             | CAP_TO_MASK(CAP_DAC_READ_SEARCH)  \
 336                             | CAP_TO_MASK(CAP_FOWNER)           \
 337                             | CAP_TO_MASK(CAP_FSETID))
 338
 339 #if _LINUX_CAPABILITY_U32S != 2
 340 # error Fix up hand-coded capability macro initializers
 341 #else /* HAND-CODED capability initializers */
 342
 343 # define CAP_EMPTY_SET    {{ 0, 0 }}
 344 # define CAP_FULL_SET     {{ ~0, ~0 }}
 345 # define CAP_INIT_EFF_SET {{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }}
 346 # define CAP_FS_SET       {{ CAP_FS_MASK_B0, 0 }}
 347 # define CAP_NFSD_SET     {{ CAP_FS_MASK_B0|CAP_TO_MASK(CAP_SYS_RESOURCE), 0 }}
 348
 349 #endif /* _LINUX_CAPABILITY_U32S != 2 */
 350
 351 #define CAP_INIT_INH_SET    CAP_EMPTY_SET
 352
 353 # define cap_clear(c)         do { (c) = __cap_empty_set; } while (0)
 354 # define cap_set_full(c)      do { (c) = __cap_full_set; } while (0)
 355 # define cap_set_init_eff(c)  do { (c) = __cap_init_eff_set; } while (0)
 356
 357 #define cap_raise(c, flag)  ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag))
 358 #define cap_lower(c, flag)  ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag))
 359 #define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag))
 360
 361 #define CAP_BOP_ALL(c, a, b, OP)                                    \
 362 do {                                                                \
 363         unsigned __capi;                                            \
 364         CAP_FOR_EACH_U32(__capi) {                                  \
 365                 c.cap[__capi] = a.cap[__capi] OP b.cap[__capi];     \
 366         }                                                           \
 367 } while (0)
 368
 369 #define CAP_UOP_ALL(c, a, OP)                                       \
 370 do {                                                                \
 371         unsigned __capi;                                            \
 372         CAP_FOR_EACH_U32(__capi) {                                  \
 373                 c.cap[__capi] = OP a.cap[__capi];                   \
 374         }                                                           \
 375 } while (0)
 376
 377 static inline kernel_cap_t cap_combine(const kernel_cap_t a,
 378                                        const kernel_cap_t b)
 379 {
 380         kernel_cap_t dest;
 381         CAP_BOP_ALL(dest, a, b, |);
 382         return dest;
 383 }
 384
 385 static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
 386                                          const kernel_cap_t b)
 387 {
 388         kernel_cap_t dest;
 389         CAP_BOP_ALL(dest, a, b, &);
 390         return dest;
 391 }
 392
 393 static inline kernel_cap_t cap_drop(const kernel_cap_t a,
 394                                     const kernel_cap_t drop)
 395 {
 396         kernel_cap_t dest;
 397         CAP_BOP_ALL(dest, a, drop, &~);
 398         return dest;
 399 }
 400
 401 static inline kernel_cap_t cap_invert(const kernel_cap_t c)
 402 {
 403         kernel_cap_t dest;
 404         CAP_UOP_ALL(dest, c, ~);
 405         return dest;
 406 }
 407
 408 static inline int cap_isclear(const kernel_cap_t a)
 409 {
 410         unsigned __capi;
 411         CAP_FOR_EACH_U32(__capi) {
 412                 if (a.cap[__capi] != 0)
 413                         return 0;
 414         }
 415         return 1;
 416 }
 417
 418 static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
 419 {
 420         kernel_cap_t dest;
 421         dest = cap_drop(a, set);
 422         return cap_isclear(dest);
 423 }
 424
 425 /* Used to decide between falling back on the old suser() or fsuser(). */
 426
 427 static inline int cap_is_fs_cap(int cap)
 428 {
 429         const kernel_cap_t __cap_fs_set = CAP_FS_SET;
 430         return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]);
 431 }
 432
 433 static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)
 434 {
 435         const kernel_cap_t __cap_fs_set = CAP_FS_SET;
 436         return cap_drop(a, __cap_fs_set);
 437 }
 438
 439 static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,
 440                                             const kernel_cap_t permitted)
 441 {
 442         const kernel_cap_t __cap_fs_set = CAP_FS_SET;
 443         return cap_combine(a,
 444                            cap_intersect(permitted, __cap_fs_set));
 445 }
 446
 447 static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)
 448 {
 449         const kernel_cap_t __cap_fs_set = CAP_NFSD_SET;
 450         return cap_drop(a, __cap_fs_set);
 451 }
 452
 453 static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,
 454                                               const kernel_cap_t permitted)
 455 {
 456         const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET;
 457         return cap_combine(a,
 458                            cap_intersect(permitted, __cap_nfsd_set));
 459 }
 460
 461 extern const kernel_cap_t __cap_empty_set;
 462 extern const kernel_cap_t __cap_full_set;
 463 extern const kernel_cap_t __cap_init_eff_set;
 464
 465 int capable(int cap);
 466 int __capable(struct task_struct *t, int cap);
 467
 468 #endif /* __KERNEL__ */
 469
 470 #endif /* !_LINUX_CAPABILITY_H */