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://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 18struct 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 40typedef struct __user_cap_header_struct { 41 __u32 version; 42 int pid; 43} __user *cap_user_header_t; 44 45typedef 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 69struct 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 92extern int file_caps_enabled; 93 94typedef 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 */ 99struct 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 (also via NET_RAW) */ 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/* Allow binding to any address for transparent proxying (also via NET_ADMIN) */ 214 215#define CAP_NET_RAW 13 216 217/* Allow locking of shared memory segments */ 218/* Allow mlock and mlockall (which doesn't really have anything to do 219 with IPC) */ 220 221#define CAP_IPC_LOCK 14 222 223/* Override IPC ownership checks */ 224 225#define CAP_IPC_OWNER 15 226 227/* Insert and remove kernel modules - modify kernel without limit */ 228#define CAP_SYS_MODULE 16 229 230/* Allow ioperm/iopl access */ 231/* Allow sending USB messages to any device via /proc/bus/usb */ 232 233#define CAP_SYS_RAWIO 17 234 235/* Allow use of chroot() */ 236 237#define CAP_SYS_CHROOT 18 238 239/* Allow ptrace() of any process */ 240 241#define CAP_SYS_PTRACE 19 242 243/* Allow configuration of process accounting */ 244 245#define CAP_SYS_PACCT 20 246 247/* Allow configuration of the secure attention key */ 248/* Allow administration of the random device */ 249/* Allow examination and configuration of disk quotas */ 250/* Allow setting the domainname */ 251/* Allow setting the hostname */ 252/* Allow calling bdflush() */ 253/* Allow mount() and umount(), setting up new smb connection */ 254/* Allow some autofs root ioctls */ 255/* Allow nfsservctl */ 256/* Allow VM86_REQUEST_IRQ */ 257/* Allow to read/write pci config on alpha */ 258/* Allow irix_prctl on mips (setstacksize) */ 259/* Allow flushing all cache on m68k (sys_cacheflush) */ 260/* Allow removing semaphores */ 261/* Used instead of CAP_CHOWN to "chown" IPC message queues, semaphores 262 and shared memory */ 263/* Allow locking/unlocking of shared memory segment */ 264/* Allow turning swap on/off */ 265/* Allow forged pids on socket credentials passing */ 266/* Allow setting readahead and flushing buffers on block devices */ 267/* Allow setting geometry in floppy driver */ 268/* Allow turning DMA on/off in xd driver */ 269/* Allow administration of md devices (mostly the above, but some 270 extra ioctls) */ 271/* Allow tuning the ide driver */ 272/* Allow access to the nvram device */ 273/* Allow administration of apm_bios, serial and bttv (TV) device */ 274/* Allow manufacturer commands in isdn CAPI support driver */ 275/* Allow reading non-standardized portions of pci configuration space */ 276/* Allow DDI debug ioctl on sbpcd driver */ 277/* Allow setting up serial ports */ 278/* Allow sending raw qic-117 commands */ 279/* Allow enabling/disabling tagged queuing on SCSI controllers and sending 280 arbitrary SCSI commands */ 281/* Allow setting encryption key on loopback filesystem */ 282/* Allow setting zone reclaim policy */ 283 284#define CAP_SYS_ADMIN 21 285 286/* Allow use of reboot() */ 287 288#define CAP_SYS_BOOT 22 289 290/* Allow raising priority and setting priority on other (different 291 UID) processes */ 292/* Allow use of FIFO and round-robin (realtime) scheduling on own 293 processes and setting the scheduling algorithm used by another 294 process. */ 295/* Allow setting cpu affinity on other processes */ 296 297#define CAP_SYS_NICE 23 298 299/* Override resource limits. Set resource limits. */ 300/* Override quota limits. */ 301/* Override reserved space on ext2 filesystem */ 302/* Modify data journaling mode on ext3 filesystem (uses journaling 303 resources) */ 304/* NOTE: ext2 honors fsuid when checking for resource overrides, so 305 you can override using fsuid too */ 306/* Override size restrictions on IPC message queues */ 307/* Allow more than 64hz interrupts from the real-time clock */ 308/* Override max number of consoles on console allocation */ 309/* Override max number of keymaps */ 310 311#define CAP_SYS_RESOURCE 24 312 313/* Allow manipulation of system clock */ 314/* Allow irix_stime on mips */ 315/* Allow setting the real-time clock */ 316 317#define CAP_SYS_TIME 25 318 319/* Allow configuration of tty devices */ 320/* Allow vhangup() of tty */ 321 322#define CAP_SYS_TTY_CONFIG 26 323 324/* Allow the privileged aspects of mknod() */ 325 326#define CAP_MKNOD 27 327 328/* Allow taking of leases on files */ 329 330#define CAP_LEASE 28 331 332#define CAP_AUDIT_WRITE 29 333 334#define CAP_AUDIT_CONTROL 30 335 336#define CAP_SETFCAP 31 337 338/* Override MAC access. 339 The base kernel enforces no MAC policy. 340 An LSM may enforce a MAC policy, and if it does and it chooses 341 to implement capability based overrides of that policy, this is 342 the capability it should use to do so. */ 343 344#define CAP_MAC_OVERRIDE 32 345 346/* Allow MAC configuration or state changes. 347 The base kernel requires no MAC configuration. 348 An LSM may enforce a MAC policy, and if it does and it chooses 349 to implement capability based checks on modifications to that 350 policy or the data required to maintain it, this is the 351 capability it should use to do so. */ 352 353#define CAP_MAC_ADMIN 33 354 355/* Allow configuring the kernel's syslog (printk behaviour) */ 356 357#define CAP_SYSLOG 34 358 359/* Allow triggering something that will wake the system */ 360 361#define CAP_WAKE_ALARM 35 362 363/* Allow preventing system suspends while epoll events are pending */ 364 365#define CAP_EPOLLWAKEUP 36 366 367#define CAP_LAST_CAP CAP_EPOLLWAKEUP 368 369#define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) 370 371/* 372 * Bit location of each capability (used by user-space library and kernel) 373 */ 374 375#define CAP_TO_INDEX(x) ((x) >> 5) /* 1 << 5 == bits in __u32 */ 376#define CAP_TO_MASK(x) (1 << ((x) & 31)) /* mask for indexed __u32 */ 377 378#ifdef __KERNEL__ 379 380struct dentry; 381struct user_namespace; 382 383struct user_namespace *current_user_ns(void); 384 385extern const kernel_cap_t __cap_empty_set; 386extern const kernel_cap_t __cap_init_eff_set; 387 388/* 389 * Internal kernel functions only 390 */ 391 392#define CAP_FOR_EACH_U32(__capi) \ 393 for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi) 394 395/* 396 * CAP_FS_MASK and CAP_NFSD_MASKS: 397 * 398 * The fs mask is all the privileges that fsuid==0 historically meant. 399 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE. 400 * 401 * It has never meant setting security.* and trusted.* xattrs. 402 * 403 * We could also define fsmask as follows: 404 * 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions 405 * 2. The security.* and trusted.* xattrs are fs-related MAC permissions 406 */ 407 408# define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \ 409 | CAP_TO_MASK(CAP_MKNOD) \ 410 | CAP_TO_MASK(CAP_DAC_OVERRIDE) \ 411 | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \ 412 | CAP_TO_MASK(CAP_FOWNER) \ 413 | CAP_TO_MASK(CAP_FSETID)) 414 415# define CAP_FS_MASK_B1 (CAP_TO_MASK(CAP_MAC_OVERRIDE)) 416 417#if _KERNEL_CAPABILITY_U32S != 2 418# error Fix up hand-coded capability macro initializers 419#else /* HAND-CODED capability initializers */ 420 421# define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }}) 422# define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }}) 423# define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \ 424 | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \ 425 CAP_FS_MASK_B1 } }) 426# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \ 427 | CAP_TO_MASK(CAP_SYS_RESOURCE), \ 428 CAP_FS_MASK_B1 } }) 429 430#endif /* _KERNEL_CAPABILITY_U32S != 2 */ 431 432# define cap_clear(c) do { (c) = __cap_empty_set; } while (0) 433 434#define cap_raise(c, flag) ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag)) 435#define cap_lower(c, flag) ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag)) 436#define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag)) 437 438#define CAP_BOP_ALL(c, a, b, OP) \ 439do { \ 440 unsigned __capi; \ 441 CAP_FOR_EACH_U32(__capi) { \ 442 c.cap[__capi] = a.cap[__capi] OP b.cap[__capi]; \ 443 } \ 444} while (0) 445 446#define CAP_UOP_ALL(c, a, OP) \ 447do { \ 448 unsigned __capi; \ 449 CAP_FOR_EACH_U32(__capi) { \ 450 c.cap[__capi] = OP a.cap[__capi]; \ 451 } \ 452} while (0) 453 454static inline kernel_cap_t cap_combine(const kernel_cap_t a, 455 const kernel_cap_t b) 456{ 457 kernel_cap_t dest; 458 CAP_BOP_ALL(dest, a, b, |); 459 return dest; 460} 461 462static inline kernel_cap_t cap_intersect(const kernel_cap_t a, 463 const kernel_cap_t b) 464{ 465 kernel_cap_t dest; 466 CAP_BOP_ALL(dest, a, b, &); 467 return dest; 468} 469 470static inline kernel_cap_t cap_drop(const kernel_cap_t a, 471 const kernel_cap_t drop) 472{ 473 kernel_cap_t dest; 474 CAP_BOP_ALL(dest, a, drop, &~); 475 return dest; 476} 477 478static inline kernel_cap_t cap_invert(const kernel_cap_t c) 479{ 480 kernel_cap_t dest; 481 CAP_UOP_ALL(dest, c, ~); 482 return dest; 483} 484 485static inline int cap_isclear(const kernel_cap_t a) 486{ 487 unsigned __capi; 488 CAP_FOR_EACH_U32(__capi) { 489 if (a.cap[__capi] != 0) 490 return 0; 491 } 492 return 1; 493} 494 495/* 496 * Check if "a" is a subset of "set". 497 * return 1 if ALL of the capabilities in "a" are also in "set" 498 * cap_issubset(0101, 1111) will return 1 499 * return 0 if ANY of the capabilities in "a" are not in "set" 500 * cap_issubset(1111, 0101) will return 0 501 */ 502static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set) 503{ 504 kernel_cap_t dest; 505 dest = cap_drop(a, set); 506 return cap_isclear(dest); 507} 508 509/* Used to decide between falling back on the old suser() or fsuser(). */ 510 511static inline int cap_is_fs_cap(int cap) 512{ 513 const kernel_cap_t __cap_fs_set = CAP_FS_SET; 514 return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]); 515} 516 517static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a) 518{ 519 const kernel_cap_t __cap_fs_set = CAP_FS_SET; 520 return cap_drop(a, __cap_fs_set); 521} 522 523static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a, 524 const kernel_cap_t permitted) 525{ 526 const kernel_cap_t __cap_fs_set = CAP_FS_SET; 527 return cap_combine(a, 528 cap_intersect(permitted, __cap_fs_set)); 529} 530 531static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a) 532{ 533 const kernel_cap_t __cap_fs_set = CAP_NFSD_SET; 534 return cap_drop(a, __cap_fs_set); 535} 536 537static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a, 538 const kernel_cap_t permitted) 539{ 540 const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET; 541 return cap_combine(a, 542 cap_intersect(permitted, __cap_nfsd_set)); 543} 544 545extern bool has_capability(struct task_struct *t, int cap); 546extern bool has_ns_capability(struct task_struct *t, 547 struct user_namespace *ns, int cap); 548extern bool has_capability_noaudit(struct task_struct *t, int cap); 549extern bool has_ns_capability_noaudit(struct task_struct *t, 550 struct user_namespace *ns, int cap); 551extern bool capable(int cap); 552extern bool ns_capable(struct user_namespace *ns, int cap); 553extern bool nsown_capable(int cap); 554 555/* audit system wants to get cap info from files as well */ 556extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); 557 558#endif /* __KERNEL__ */ 559 560#endif /* !_LINUX_CAPABILITY_H */ 561