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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 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_REVISION_SHIFT 24
57#define VFS_CAP_FLAGS_MASK ~VFS_CAP_REVISION_MASK
58#define VFS_CAP_FLAGS_EFFECTIVE 0x000001
59
60#define VFS_CAP_REVISION_1 0x01000000
61#define VFS_CAP_U32_1 1
62#define XATTR_CAPS_SZ_1 (sizeof(__le32)*(1 + 2*VFS_CAP_U32_1))
63
64#define VFS_CAP_REVISION_2 0x02000000
65#define VFS_CAP_U32_2 2
66#define XATTR_CAPS_SZ_2 (sizeof(__le32)*(1 + 2*VFS_CAP_U32_2))
67
68#define XATTR_CAPS_SZ XATTR_CAPS_SZ_2
69#define VFS_CAP_U32 VFS_CAP_U32_2
70#define VFS_CAP_REVISION VFS_CAP_REVISION_2
71
72struct 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#ifndef __KERNEL__
81
82/*
83 * Backwardly compatible definition for source code - trapped in a
84 * 32-bit world. If you find you need this, please consider using
85 * libcap to untrap yourself...
86 */
87#define _LINUX_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_1
88#define _LINUX_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_1
89
90#else
91
92#define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3
93#define _KERNEL_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3
94
95extern int file_caps_enabled;
96
97typedef struct kernel_cap_struct {
98 __u32 cap[_KERNEL_CAPABILITY_U32S];
99} kernel_cap_t;
100
101/* exact same as vfs_cap_data but in cpu endian and always filled completely */
102struct cpu_vfs_cap_data {
103 __u32 magic_etc;
104 kernel_cap_t permitted;
105 kernel_cap_t inheritable;
106};
107
108#define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct))
109#define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t))
110
111#endif
112
113
114/**
115 ** POSIX-draft defined capabilities.
116 **/
117
118/* In a system with the [_POSIX_CHOWN_RESTRICTED] option defined, this
119 overrides the restriction of changing file ownership and group
120 ownership. */
121
122#define CAP_CHOWN 0
123
124/* Override all DAC access, including ACL execute access if
125 [_POSIX_ACL] is defined. Excluding DAC access covered by
126 CAP_LINUX_IMMUTABLE. */
127
128#define CAP_DAC_OVERRIDE 1
129
130/* Overrides all DAC restrictions regarding read and search on files
131 and directories, including ACL restrictions if [_POSIX_ACL] is
132 defined. Excluding DAC access covered by CAP_LINUX_IMMUTABLE. */
133
134#define CAP_DAC_READ_SEARCH 2
135
136/* Overrides all restrictions about allowed operations on files, where
137 file owner ID must be equal to the user ID, except where CAP_FSETID
138 is applicable. It doesn't override MAC and DAC restrictions. */
139
140#define CAP_FOWNER 3
141
142/* Overrides the following restrictions that the effective user ID
143 shall match the file owner ID when setting the S_ISUID and S_ISGID
144 bits on that file; that the effective group ID (or one of the
145 supplementary group IDs) shall match the file owner ID when setting
146 the S_ISGID bit on that file; that the S_ISUID and S_ISGID bits are
147 cleared on successful return from chown(2) (not implemented). */
148
149#define CAP_FSETID 4
150
151/* Overrides the restriction that the real or effective user ID of a
152 process sending a signal must match the real or effective user ID
153 of the process receiving the signal. */
154
155#define CAP_KILL 5
156
157/* Allows setgid(2) manipulation */
158/* Allows setgroups(2) */
159/* Allows forged gids on socket credentials passing. */
160
161#define CAP_SETGID 6
162
163/* Allows set*uid(2) manipulation (including fsuid). */
164/* Allows forged pids on socket credentials passing. */
165
166#define CAP_SETUID 7
167
168
169/**
170 ** Linux-specific capabilities
171 **/
172
173/* Without VFS support for capabilities:
174 * Transfer any capability in your permitted set to any pid,
175 * remove any capability in your permitted set from any pid
176 * With VFS support for capabilities (neither of above, but)
177 * Add any capability from current's capability bounding set
178 * to the current process' inheritable set
179 * Allow taking bits out of capability bounding set
180 * Allow modification of the securebits for a process
181 */
182
183#define CAP_SETPCAP 8
184
185/* Allow modification of S_IMMUTABLE and S_APPEND file attributes */
186
187#define CAP_LINUX_IMMUTABLE 9
188
189/* Allows binding to TCP/UDP sockets below 1024 */
190/* Allows binding to ATM VCIs below 32 */
191
192#define CAP_NET_BIND_SERVICE 10
193
194/* Allow broadcasting, listen to multicast */
195
196#define CAP_NET_BROADCAST 11
197
198/* Allow interface configuration */
199/* Allow administration of IP firewall, masquerading and accounting */
200/* Allow setting debug option on sockets */
201/* Allow modification of routing tables */
202/* Allow setting arbitrary process / process group ownership on
203 sockets */
204/* Allow binding to any address for transparent proxying */
205/* Allow setting TOS (type of service) */
206/* Allow setting promiscuous mode */
207/* Allow clearing driver statistics */
208/* Allow multicasting */
209/* Allow read/write of device-specific registers */
210/* Allow activation of ATM control sockets */
211
212#define CAP_NET_ADMIN 12
213
214/* Allow use of RAW sockets */
215/* Allow use of PACKET sockets */
216
217#define CAP_NET_RAW 13
218
219/* Allow locking of shared memory segments */
220/* Allow mlock and mlockall (which doesn't really have anything to do
221 with IPC) */
222
223#define CAP_IPC_LOCK 14
224
225/* Override IPC ownership checks */
226
227#define CAP_IPC_OWNER 15
228
229/* Insert and remove kernel modules - modify kernel without limit */
230#define CAP_SYS_MODULE 16
231
232/* Allow ioperm/iopl access */
233/* Allow sending USB messages to any device via /proc/bus/usb */
234
235#define CAP_SYS_RAWIO 17
236
237/* Allow use of chroot() */
238
239#define CAP_SYS_CHROOT 18
240
241/* Allow ptrace() of any process */
242
243#define CAP_SYS_PTRACE 19
244
245/* Allow configuration of process accounting */
246
247#define CAP_SYS_PACCT 20
248
249/* Allow configuration of the secure attention key */
250/* Allow administration of the random device */
251/* Allow examination and configuration of disk quotas */
252/* Allow configuring the kernel's syslog (printk behaviour) */
253/* Allow setting the domainname */
254/* Allow setting the hostname */
255/* Allow calling bdflush() */
256/* Allow mount() and umount(), setting up new smb connection */
257/* Allow some autofs root ioctls */
258/* Allow nfsservctl */
259/* Allow VM86_REQUEST_IRQ */
260/* Allow to read/write pci config on alpha */
261/* Allow irix_prctl on mips (setstacksize) */
262/* Allow flushing all cache on m68k (sys_cacheflush) */
263/* Allow removing semaphores */
264/* Used instead of CAP_CHOWN to "chown" IPC message queues, semaphores
265 and shared memory */
266/* Allow locking/unlocking of shared memory segment */
267/* Allow turning swap on/off */
268/* Allow forged pids on socket credentials passing */
269/* Allow setting readahead and flushing buffers on block devices */
270/* Allow setting geometry in floppy driver */
271/* Allow turning DMA on/off in xd driver */
272/* Allow administration of md devices (mostly the above, but some
273 extra ioctls) */
274/* Allow tuning the ide driver */
275/* Allow access to the nvram device */
276/* Allow administration of apm_bios, serial and bttv (TV) device */
277/* Allow manufacturer commands in isdn CAPI support driver */
278/* Allow reading non-standardized portions of pci configuration space */
279/* Allow DDI debug ioctl on sbpcd driver */
280/* Allow setting up serial ports */
281/* Allow sending raw qic-117 commands */
282/* Allow enabling/disabling tagged queuing on SCSI controllers and sending
283 arbitrary SCSI commands */
284/* Allow setting encryption key on loopback filesystem */
285/* Allow setting zone reclaim policy */
286
287#define CAP_SYS_ADMIN 21
288
289/* Allow use of reboot() */
290
291#define CAP_SYS_BOOT 22
292
293/* Allow raising priority and setting priority on other (different
294 UID) processes */
295/* Allow use of FIFO and round-robin (realtime) scheduling on own
296 processes and setting the scheduling algorithm used by another
297 process. */
298/* Allow setting cpu affinity on other processes */
299
300#define CAP_SYS_NICE 23
301
302/* Override resource limits. Set resource limits. */
303/* Override quota limits. */
304/* Override reserved space on ext2 filesystem */
305/* Modify data journaling mode on ext3 filesystem (uses journaling
306 resources) */
307/* NOTE: ext2 honors fsuid when checking for resource overrides, so
308 you can override using fsuid too */
309/* Override size restrictions on IPC message queues */
310/* Allow more than 64hz interrupts from the real-time clock */
311/* Override max number of consoles on console allocation */
312/* Override max number of keymaps */
313
314#define CAP_SYS_RESOURCE 24
315
316/* Allow manipulation of system clock */
317/* Allow irix_stime on mips */
318/* Allow setting the real-time clock */
319
320#define CAP_SYS_TIME 25
321
322/* Allow configuration of tty devices */
323/* Allow vhangup() of tty */
324
325#define CAP_SYS_TTY_CONFIG 26
326
327/* Allow the privileged aspects of mknod() */
328
329#define CAP_MKNOD 27
330
331/* Allow taking of leases on files */
332
333#define CAP_LEASE 28
334
335#define CAP_AUDIT_WRITE 29
336
337#define CAP_AUDIT_CONTROL 30
338
339#define CAP_SETFCAP 31
340
341/* Override MAC access.
342 The base kernel enforces no MAC policy.
343 An LSM may enforce a MAC policy, and if it does and it chooses
344 to implement capability based overrides of that policy, this is
345 the capability it should use to do so. */
346
347#define CAP_MAC_OVERRIDE 32
348
349/* Allow MAC configuration or state changes.
350 The base kernel requires no MAC configuration.
351 An LSM may enforce a MAC policy, and if it does and it chooses
352 to implement capability based checks on modifications to that
353 policy or the data required to maintain it, this is the
354 capability it should use to do so. */
355
356#define CAP_MAC_ADMIN 33
357
358#define CAP_LAST_CAP CAP_MAC_ADMIN
359
360#define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)
361
362/*
363 * Bit location of each capability (used by user-space library and kernel)
364 */
365
366#define CAP_TO_INDEX(x) ((x) >> 5) /* 1 << 5 == bits in __u32 */
367#define CAP_TO_MASK(x) (1 << ((x) & 31)) /* mask for indexed __u32 */
368
369#ifdef __KERNEL__
370
371/*
372 * Internal kernel functions only
373 */
374
375#define CAP_FOR_EACH_U32(__capi) \
376 for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)
377
378/*
379 * CAP_FS_MASK and CAP_NFSD_MASKS:
380 *
381 * The fs mask is all the privileges that fsuid==0 historically meant.
382 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.
383 *
384 * It has never meant setting security.* and trusted.* xattrs.
385 *
386 * We could also define fsmask as follows:
387 * 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions
388 * 2. The security.* and trusted.* xattrs are fs-related MAC permissions
389 */
390
391# define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \
392 | CAP_TO_MASK(CAP_MKNOD) \
393 | CAP_TO_MASK(CAP_DAC_OVERRIDE) \
394 | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \
395 | CAP_TO_MASK(CAP_FOWNER) \
396 | CAP_TO_MASK(CAP_FSETID))
397
398# define CAP_FS_MASK_B1 (CAP_TO_MASK(CAP_MAC_OVERRIDE))
399
400#if _KERNEL_CAPABILITY_U32S != 2
401# error Fix up hand-coded capability macro initializers
402#else /* HAND-CODED capability initializers */
403
404# define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }})
405# define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }})
406# define CAP_INIT_EFF_SET ((kernel_cap_t){{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }})
407# define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
408 | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
409 CAP_FS_MASK_B1 } })
410# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
411 | CAP_TO_MASK(CAP_SYS_RESOURCE), \
412 CAP_FS_MASK_B1 } })
413
414#endif /* _KERNEL_CAPABILITY_U32S != 2 */
415
416#define CAP_INIT_INH_SET CAP_EMPTY_SET
417
418# define cap_clear(c) do { (c) = __cap_empty_set; } while (0)
419# define cap_set_full(c) do { (c) = __cap_full_set; } while (0)
420# define cap_set_init_eff(c) do { (c) = __cap_init_eff_set; } while (0)
421
422#define cap_raise(c, flag) ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag))
423#define cap_lower(c, flag) ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag))
424#define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag))
425
426#define CAP_BOP_ALL(c, a, b, OP) \
427do { \
428 unsigned __capi; \
429 CAP_FOR_EACH_U32(__capi) { \
430 c.cap[__capi] = a.cap[__capi] OP b.cap[__capi]; \
431 } \
432} while (0)
433
434#define CAP_UOP_ALL(c, a, OP) \
435do { \
436 unsigned __capi; \
437 CAP_FOR_EACH_U32(__capi) { \
438 c.cap[__capi] = OP a.cap[__capi]; \
439 } \
440} while (0)
441
442static inline kernel_cap_t cap_combine(const kernel_cap_t a,
443 const kernel_cap_t b)
444{
445 kernel_cap_t dest;
446 CAP_BOP_ALL(dest, a, b, |);
447 return dest;
448}
449
450static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
451 const kernel_cap_t b)
452{
453 kernel_cap_t dest;
454 CAP_BOP_ALL(dest, a, b, &);
455 return dest;
456}
457
458static inline kernel_cap_t cap_drop(const kernel_cap_t a,
459 const kernel_cap_t drop)
460{
461 kernel_cap_t dest;
462 CAP_BOP_ALL(dest, a, drop, &~);
463 return dest;
464}
465
466static inline kernel_cap_t cap_invert(const kernel_cap_t c)
467{
468 kernel_cap_t dest;
469 CAP_UOP_ALL(dest, c, ~);
470 return dest;
471}
472
473static inline int cap_isclear(const kernel_cap_t a)
474{
475 unsigned __capi;
476 CAP_FOR_EACH_U32(__capi) {
477 if (a.cap[__capi] != 0)
478 return 0;
479 }
480 return 1;
481}
482
483/*
484 * Check if "a" is a subset of "set".
485 * return 1 if ALL of the capabilities in "a" are also in "set"
486 * cap_issubset(0101, 1111) will return 1
487 * return 0 if ANY of the capabilities in "a" are not in "set"
488 * cap_issubset(1111, 0101) will return 0
489 */
490static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
491{
492 kernel_cap_t dest;
493 dest = cap_drop(a, set);
494 return cap_isclear(dest);
495}
496
497/* Used to decide between falling back on the old suser() or fsuser(). */
498
499static inline int cap_is_fs_cap(int cap)
500{
501 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
502 return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]);
503}
504
505static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)
506{
507 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
508 return cap_drop(a, __cap_fs_set);
509}
510
511static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,
512 const kernel_cap_t permitted)
513{
514 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
515 return cap_combine(a,
516 cap_intersect(permitted, __cap_fs_set));
517}
518
519static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)
520{
521 const kernel_cap_t __cap_fs_set = CAP_NFSD_SET;
522 return cap_drop(a, __cap_fs_set);
523}
524
525static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,
526 const kernel_cap_t permitted)
527{
528 const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET;
529 return cap_combine(a,
530 cap_intersect(permitted, __cap_nfsd_set));
531}
532
533extern const kernel_cap_t __cap_empty_set;
534extern const kernel_cap_t __cap_full_set;
535extern const kernel_cap_t __cap_init_eff_set;
536
537/**
538 * has_capability - Determine if a task has a superior capability available
539 * @t: The task in question
540 * @cap: The capability to be tested for
541 *
542 * Return true if the specified task has the given superior capability
543 * currently in effect, false if not.
544 *
545 * Note that this does not set PF_SUPERPRIV on the task.
546 */
547#define has_capability(t, cap) (security_real_capable((t), (cap)) == 0)
548
549/**
550 * has_capability_noaudit - Determine if a task has a superior capability available (unaudited)
551 * @t: The task in question
552 * @cap: The capability to be tested for
553 *
554 * Return true if the specified task has the given superior capability
555 * currently in effect, false if not, but don't write an audit message for the
556 * check.
557 *
558 * Note that this does not set PF_SUPERPRIV on the task.
559 */
560#define has_capability_noaudit(t, cap) \
561 (security_real_capable_noaudit((t), (cap)) == 0)
562
563extern int capable(int cap);
564
565/* audit system wants to get cap info from files as well */
566struct dentry;
567extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);
568
569#endif /* __KERNEL__ */
570
571#endif /* !_LINUX_CAPABILITY_H */