1 /* 2 * This is <linux/capability.h> 3 * 4 * Andrew G. Morgan <morgan (at) kernel.org> 5 * Alexander Kjeldaas <astor (at) 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://www.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 /* deprecated - use v3 */ 35 #define _LINUX_CAPABILITY_U32S_2 2 36 37 #define _LINUX_CAPABILITY_VERSION_3 0x20080522 38 #define _LINUX_CAPABILITY_U32S_3 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 VFS_CAP_REVISION_MASK 0xFF000000 53 #define VFS_CAP_REVISION_SHIFT 24 54 #define VFS_CAP_FLAGS_MASK ~VFS_CAP_REVISION_MASK 55 #define VFS_CAP_FLAGS_EFFECTIVE 0x000001 56 57 #define VFS_CAP_REVISION_1 0x01000000 58 #define VFS_CAP_U32_1 1 59 #define XATTR_CAPS_SZ_1 (sizeof(__le32)*(1 + 2*VFS_CAP_U32_1)) 60 61 #define VFS_CAP_REVISION_2 0x02000000 62 #define VFS_CAP_U32_2 2 63 #define XATTR_CAPS_SZ_2 (sizeof(__le32)*(1 + 2*VFS_CAP_U32_2)) 64 65 #define XATTR_CAPS_SZ XATTR_CAPS_SZ_2 66 #define VFS_CAP_U32 VFS_CAP_U32_2 67 #define VFS_CAP_REVISION VFS_CAP_REVISION_2 68 69 struct vfs_cap_data { 70 __le32 magic_etc; /* Little endian */ 71 struct { 72 __le32 permitted; /* Little endian */ 73 __le32 inheritable; /* Little endian */ 74 } data[VFS_CAP_U32]; 75 }; 76 77 #ifndef __KERNEL__ 78 79 /* 80 * Backwardly compatible definition for source code - trapped in a 81 * 32-bit world. If you find you need this, please consider using 82 * libcap to untrap yourself... 83 */ 84 #define _LINUX_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_1 85 #define _LINUX_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_1 86 87 #else 88 89 #define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3 90 #define _KERNEL_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3 91 92 extern int file_caps_enabled; 93 94 typedef struct kernel_cap_struct { 95 __u32 cap[_KERNEL_CAPABILITY_U32S]; 96 } kernel_cap_t; 97 98 /* exact same as vfs_cap_data but in cpu endian and always filled completely */ 99 struct cpu_vfs_cap_data { 100 __u32 magic_etc; 101 kernel_cap_t permitted; 102 kernel_cap_t inheritable; 103 }; 104 105 #define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct)) 106 #define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t)) 107 108 #endif 109 110 111 /** 112 ** POSIX-draft defined capabilities. 113 **/ 114 115 /* In a system with the [_POSIX_CHOWN_RESTRICTED] option defined, this 116 overrides the restriction of changing file ownership and group 117 ownership. */ 118 119 #define CAP_CHOWN 0 120 121 /* Override all DAC access, including ACL execute access if 122 [_POSIX_ACL] is defined. Excluding DAC access covered by 123 CAP_LINUX_IMMUTABLE. */ 124 125 #define CAP_DAC_OVERRIDE 1 126 127 /* Overrides all DAC restrictions regarding read and search on files 128 and directories, including ACL restrictions if [_POSIX_ACL] is 129 defined. Excluding DAC access covered by CAP_LINUX_IMMUTABLE. */ 130 131 #define CAP_DAC_READ_SEARCH 2 132 133 /* Overrides all restrictions about allowed operations on files, where 134 file owner ID must be equal to the user ID, except where CAP_FSETID 135 is applicable. It doesn't override MAC and DAC restrictions. */ 136 137 #define CAP_FOWNER 3 138 139 /* Overrides the following restrictions that the effective user ID 140 shall match the file owner ID when setting the S_ISUID and S_ISGID 141 bits on that file; that the effective group ID (or one of the 142 supplementary group IDs) shall match the file owner ID when setting 143 the S_ISGID bit on that file; that the S_ISUID and S_ISGID bits are 144 cleared on successful return from chown(2) (not implemented). */ 145 146 #define CAP_FSETID 4 147 148 /* Overrides the restriction that the real or effective user ID of a 149 process sending a signal must match the real or effective user ID 150 of the process receiving the signal. */ 151 152 #define CAP_KILL 5 153 154 /* Allows setgid(2) manipulation */ 155 /* Allows setgroups(2) */ 156 /* Allows forged gids on socket credentials passing. */ 157 158 #define CAP_SETGID 6 159 160 /* Allows set*uid(2) manipulation (including fsuid). */ 161 /* Allows forged pids on socket credentials passing. */ 162 163 #define CAP_SETUID 7 164 165 166 /** 167 ** Linux-specific capabilities 168 **/ 169 170 /* Without VFS support for capabilities: 171 * Transfer any capability in your permitted set to any pid, 172 * remove any capability in your permitted set from any pid 173 * With VFS support for capabilities (neither of above, but) 174 * Add any capability from current's capability bounding set 175 * to the current process' inheritable set 176 * Allow taking bits out of capability bounding set 177 * Allow modification of the securebits for a process 178 */ 179 180 #define CAP_SETPCAP 8 181 182 /* Allow modification of S_IMMUTABLE and S_APPEND file attributes */ 183 184 #define CAP_LINUX_IMMUTABLE 9 185 186 /* Allows binding to TCP/UDP sockets below 1024 */ 187 /* Allows binding to ATM VCIs below 32 */ 188 189 #define CAP_NET_BIND_SERVICE 10 190 191 /* Allow broadcasting, listen to multicast */ 192 193 #define CAP_NET_BROADCAST 11 194 195 /* Allow interface configuration */ 196 /* Allow administration of IP firewall, masquerading and accounting */ 197 /* Allow setting debug option on sockets */ 198 /* Allow modification of routing tables */ 199 /* Allow setting arbitrary process / process group ownership on 200 sockets */ 201 /* Allow binding to any address for transparent proxying */ 202 /* Allow setting TOS (type of service) */ 203 /* Allow setting promiscuous mode */ 204 /* Allow clearing driver statistics */ 205 /* Allow multicasting */ 206 /* Allow read/write of device-specific registers */ 207 /* Allow activation of ATM control sockets */ 208 209 #define CAP_NET_ADMIN 12 210 211 /* Allow use of RAW sockets */ 212 /* Allow use of PACKET sockets */ 213 214 #define CAP_NET_RAW 13 215 216 /* Allow locking of shared memory segments */ 217 /* Allow mlock and mlockall (which doesn't really have anything to do 218 with IPC) */ 219 220 #define CAP_IPC_LOCK 14 221 222 /* Override IPC ownership checks */ 223 224 #define CAP_IPC_OWNER 15 225 226 /* Insert and remove kernel modules - modify kernel without limit */ 227 #define CAP_SYS_MODULE 16 228 229 /* Allow ioperm/iopl access */ 230 /* Allow sending USB messages to any device via /proc/bus/usb */ 231 232 #define CAP_SYS_RAWIO 17 233 234 /* Allow use of chroot() */ 235 236 #define CAP_SYS_CHROOT 18 237 238 /* Allow ptrace() of any process */ 239 240 #define CAP_SYS_PTRACE 19 241 242 /* Allow configuration of process accounting */ 243 244 #define CAP_SYS_PACCT 20 245 246 /* Allow configuration of the secure attention key */ 247 /* Allow administration of the random device */ 248 /* Allow examination and configuration of disk quotas */ 249 /* Allow setting the domainname */ 250 /* Allow setting the hostname */ 251 /* Allow calling bdflush() */ 252 /* Allow mount() and umount(), setting up new smb connection */ 253 /* Allow some autofs root ioctls */ 254 /* Allow nfsservctl */ 255 /* Allow VM86_REQUEST_IRQ */ 256 /* Allow to read/write pci config on alpha */ 257 /* Allow irix_prctl on mips (setstacksize) */ 258 /* Allow flushing all cache on m68k (sys_cacheflush) */ 259 /* Allow removing semaphores */ 260 /* Used instead of CAP_CHOWN to "chown" IPC message queues, semaphores 261 and shared memory */ 262 /* Allow locking/unlocking of shared memory segment */ 263 /* Allow turning swap on/off */ 264 /* Allow forged pids on socket credentials passing */ 265 /* Allow setting readahead and flushing buffers on block devices */ 266 /* Allow setting geometry in floppy driver */ 267 /* Allow turning DMA on/off in xd driver */ 268 /* Allow administration of md devices (mostly the above, but some 269 extra ioctls) */ 270 /* Allow tuning the ide driver */ 271 /* Allow access to the nvram device */ 272 /* Allow administration of apm_bios, serial and bttv (TV) device */ 273 /* Allow manufacturer commands in isdn CAPI support driver */ 274 /* Allow reading non-standardized portions of pci configuration space */ 275 /* Allow DDI debug ioctl on sbpcd driver */ 276 /* Allow setting up serial ports */ 277 /* Allow sending raw qic-117 commands */ 278 /* Allow enabling/disabling tagged queuing on SCSI controllers and sending 279 arbitrary SCSI commands */ 280 /* Allow setting encryption key on loopback filesystem */ 281 /* Allow setting zone reclaim policy */ 282 283 #define CAP_SYS_ADMIN 21 284 285 /* Allow use of reboot() */ 286 287 #define CAP_SYS_BOOT 22 288 289 /* Allow raising priority and setting priority on other (different 290 UID) processes */ 291 /* Allow use of FIFO and round-robin (realtime) scheduling on own 292 processes and setting the scheduling algorithm used by another 293 process. */ 294 /* Allow setting cpu affinity on other processes */ 295 296 #define CAP_SYS_NICE 23 297 298 /* Override resource limits. Set resource limits. */ 299 /* Override quota limits. */ 300 /* Override reserved space on ext2 filesystem */ 301 /* Modify data journaling mode on ext3 filesystem (uses journaling 302 resources) */ 303 /* NOTE: ext2 honors fsuid when checking for resource overrides, so 304 you can override using fsuid too */ 305 /* Override size restrictions on IPC message queues */ 306 /* Allow more than 64hz interrupts from the real-time clock */ 307 /* Override max number of consoles on console allocation */ 308 /* Override max number of keymaps */ 309 310 #define CAP_SYS_RESOURCE 24 311 312 /* Allow manipulation of system clock */ 313 /* Allow irix_stime on mips */ 314 /* Allow setting the real-time clock */ 315 316 #define CAP_SYS_TIME 25 317 318 /* Allow configuration of tty devices */ 319 /* Allow vhangup() of tty */ 320 321 #define CAP_SYS_TTY_CONFIG 26 322 323 /* Allow the privileged aspects of mknod() */ 324 325 #define CAP_MKNOD 27 326 327 /* Allow taking of leases on files */ 328 329 #define CAP_LEASE 28 330 331 #define CAP_AUDIT_WRITE 29 332 333 #define CAP_AUDIT_CONTROL 30 334 335 #define CAP_SETFCAP 31 336 337 /* Override MAC access. 338 The base kernel enforces no MAC policy. 339 An LSM may enforce a MAC policy, and if it does and it chooses 340 to implement capability based overrides of that policy, this is 341 the capability it should use to do so. */ 342 343 #define CAP_MAC_OVERRIDE 32 344 345 /* Allow MAC configuration or state changes. 346 The base kernel requires no MAC configuration. 347 An LSM may enforce a MAC policy, and if it does and it chooses 348 to implement capability based checks on modifications to that 349 policy or the data required to maintain it, this is the 350 capability it should use to do so. */ 351 352 #define CAP_MAC_ADMIN 33 353 354 /* Allow configuring the kernel's syslog (printk behaviour) */ 355 356 #define CAP_SYSLOG 34 357 358 /* Allow triggering something that will wake the system */ 359 360 #define CAP_WAKE_ALARM 35 361 362 363 #define CAP_LAST_CAP CAP_WAKE_ALARM 364 365 #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) 366 367 /* 368 * Bit location of each capability (used by user-space library and kernel) 369 */ 370 371 #define CAP_TO_INDEX(x) ((x) >> 5) /* 1 << 5 == bits in __u32 */ 372 #define CAP_TO_MASK(x) (1 << ((x) & 31)) /* mask for indexed __u32 */ 373 374 #ifdef __KERNEL__ 375 376 struct dentry; 377 struct user_namespace; 378 379 struct user_namespace *current_user_ns(void); 380 381 extern const kernel_cap_t __cap_empty_set; 382 extern const kernel_cap_t __cap_full_set; 383 extern const kernel_cap_t __cap_init_eff_set; 384 385 /* 386 * Internal kernel functions only 387 */ 388 389 #define CAP_FOR_EACH_U32(__capi) \ 390 for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi) 391 392 /* 393 * CAP_FS_MASK and CAP_NFSD_MASKS: 394 * 395 * The fs mask is all the privileges that fsuid==0 historically meant. 396 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE. 397 * 398 * It has never meant setting security.* and trusted.* xattrs. 399 * 400 * We could also define fsmask as follows: 401 * 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions 402 * 2. The security.* and trusted.* xattrs are fs-related MAC permissions 403 */ 404 405 # define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \ 406 | CAP_TO_MASK(CAP_MKNOD) \ 407 | CAP_TO_MASK(CAP_DAC_OVERRIDE) \ 408 | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \ 409 | CAP_TO_MASK(CAP_FOWNER) \ 410 | CAP_TO_MASK(CAP_FSETID)) 411 412 # define CAP_FS_MASK_B1 (CAP_TO_MASK(CAP_MAC_OVERRIDE)) 413 414 #if _KERNEL_CAPABILITY_U32S != 2 415 # error Fix up hand-coded capability macro initializers 416 #else /* HAND-CODED capability initializers */ 417 418 # define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }}) 419 # define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }}) 420 # define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \ 421 | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \ 422 CAP_FS_MASK_B1 } }) 423 # define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \ 424 | CAP_TO_MASK(CAP_SYS_RESOURCE), \ 425 CAP_FS_MASK_B1 } }) 426 427 #endif /* _KERNEL_CAPABILITY_U32S != 2 */ 428 429 # define cap_clear(c) do { (c) = __cap_empty_set; } while (0) 430 431 #define cap_raise(c, flag) ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag)) 432 #define cap_lower(c, flag) ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag)) 433 #define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag)) 434 435 #define CAP_BOP_ALL(c, a, b, OP) \ 436 do { \ 437 unsigned __capi; \ 438 CAP_FOR_EACH_U32(__capi) { \ 439 c.cap[__capi] = a.cap[__capi] OP b.cap[__capi]; \ 440 } \ 441 } while (0) 442 443 #define CAP_UOP_ALL(c, a, OP) \ 444 do { \ 445 unsigned __capi; \ 446 CAP_FOR_EACH_U32(__capi) { \ 447 c.cap[__capi] = OP a.cap[__capi]; \ 448 } \ 449 } while (0) 450 451 static inline kernel_cap_t cap_combine(const kernel_cap_t a, 452 const kernel_cap_t b) 453 { 454 kernel_cap_t dest; 455 CAP_BOP_ALL(dest, a, b, |); 456 return dest; 457 } 458 459 static inline kernel_cap_t cap_intersect(const kernel_cap_t a, 460 const kernel_cap_t b) 461 { 462 kernel_cap_t dest; 463 CAP_BOP_ALL(dest, a, b, &); 464 return dest; 465 } 466 467 static inline kernel_cap_t cap_drop(const kernel_cap_t a, 468 const kernel_cap_t drop) 469 { 470 kernel_cap_t dest; 471 CAP_BOP_ALL(dest, a, drop, &~); 472 return dest; 473 } 474 475 static inline kernel_cap_t cap_invert(const kernel_cap_t c) 476 { 477 kernel_cap_t dest; 478 CAP_UOP_ALL(dest, c, ~); 479 return dest; 480 } 481 482 static inline int cap_isclear(const kernel_cap_t a) 483 { 484 unsigned __capi; 485 CAP_FOR_EACH_U32(__capi) { 486 if (a.cap[__capi] != 0) 487 return 0; 488 } 489 return 1; 490 } 491 492 /* 493 * Check if "a" is a subset of "set". 494 * return 1 if ALL of the capabilities in "a" are also in "set" 495 * cap_issubset(0101, 1111) will return 1 496 * return 0 if ANY of the capabilities in "a" are not in "set" 497 * cap_issubset(1111, 0101) will return 0 498 */ 499 static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set) 500 { 501 kernel_cap_t dest; 502 dest = cap_drop(a, set); 503 return cap_isclear(dest); 504 } 505 506 /* Used to decide between falling back on the old suser() or fsuser(). */ 507 508 static inline int cap_is_fs_cap(int cap) 509 { 510 const kernel_cap_t __cap_fs_set = CAP_FS_SET; 511 return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]); 512 } 513 514 static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a) 515 { 516 const kernel_cap_t __cap_fs_set = CAP_FS_SET; 517 return cap_drop(a, __cap_fs_set); 518 } 519 520 static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a, 521 const kernel_cap_t permitted) 522 { 523 const kernel_cap_t __cap_fs_set = CAP_FS_SET; 524 return cap_combine(a, 525 cap_intersect(permitted, __cap_fs_set)); 526 } 527 528 static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a) 529 { 530 const kernel_cap_t __cap_fs_set = CAP_NFSD_SET; 531 return cap_drop(a, __cap_fs_set); 532 } 533 534 static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a, 535 const kernel_cap_t permitted) 536 { 537 const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET; 538 return cap_combine(a, 539 cap_intersect(permitted, __cap_nfsd_set)); 540 } 541 542 extern bool has_capability(struct task_struct *t, int cap); 543 extern bool has_ns_capability(struct task_struct *t, 544 struct user_namespace *ns, int cap); 545 extern bool has_capability_noaudit(struct task_struct *t, int cap); 546 extern bool capable(int cap); 547 extern bool ns_capable(struct user_namespace *ns, int cap); 548 extern bool task_ns_capable(struct task_struct *t, int cap); 549 extern bool nsown_capable(int cap); 550 551 /* audit system wants to get cap info from files as well */ 552 extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); 553 554 #endif /* __KERNEL__ */ 555 556 #endif /* !_LINUX_CAPABILITY_H */ 557
