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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This is <linux/capability.h>
3 *
Serge E. Hallynb5376772007-10-16 23:31:36 -07004 * Andrew G. Morgan <morgan@kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * 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 *
GeunSik Limbcf56442009-06-16 10:26:25 +020010 * ftp://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/
Serge E. Hallynb5376772007-10-16 23:31:36 -070011 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#ifndef _LINUX_CAPABILITY_H
13#define _LINUX_CAPABILITY_H
14
David Howells607ca462012-10-13 10:46:48 +010015#include <uapi/linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Andrew G. Morganca05a992008-05-27 22:05:17 -070017
18#define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3
19#define _KERNEL_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Jaswinder Singh Rajput9fa91d92009-01-30 20:39:30 +053021extern int file_caps_enabled;
Jaswinder Singh Rajput9fa91d92009-01-30 20:39:30 +053022
Linus Torvalds1da177e2005-04-16 15:20:36 -070023typedef struct kernel_cap_struct {
Andrew G. Morganca05a992008-05-27 22:05:17 -070024 __u32 cap[_KERNEL_CAPABILITY_U32S];
Linus Torvalds1da177e2005-04-16 15:20:36 -070025} kernel_cap_t;
26
Eric Parisc0b00442008-11-11 21:48:10 +110027/* exact same as vfs_cap_data but in cpu endian and always filled completely */
28struct cpu_vfs_cap_data {
29 __u32 magic_etc;
30 kernel_cap_t permitted;
31 kernel_cap_t inheritable;
32};
33
Andrew Morgane338d262008-02-04 22:29:42 -080034#define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct))
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t))
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Linus Torvalds935d8aa2013-04-14 10:06:31 -070038struct file;
Eric W. Biederman1a48e2a2011-11-14 16:24:06 -080039struct inode;
Serge E. Hallyn34867402011-03-23 16:43:17 -070040struct dentry;
Alexey Dobriyandb3f6002016-08-02 14:03:36 -070041struct task_struct;
Serge E. Hallyn34867402011-03-23 16:43:17 -070042struct user_namespace;
43
Serge E. Hallyn34867402011-03-23 16:43:17 -070044extern const kernel_cap_t __cap_empty_set;
Serge E. Hallyn34867402011-03-23 16:43:17 -070045extern const kernel_cap_t __cap_init_eff_set;
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047/*
48 * Internal kernel functions only
49 */
Serge E. Hallynb5376772007-10-16 23:31:36 -070050
Andrew Morgane338d262008-02-04 22:29:42 -080051#define CAP_FOR_EACH_U32(__capi) \
Andrew G. Morganca05a992008-05-27 22:05:17 -070052 for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050054/*
55 * CAP_FS_MASK and CAP_NFSD_MASKS:
56 *
57 * The fs mask is all the privileges that fsuid==0 historically meant.
58 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.
59 *
60 * It has never meant setting security.* and trusted.* xattrs.
61 *
62 * We could also define fsmask as follows:
63 * 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions
64 * 2. The security.* and trusted.* xattrs are fs-related MAC permissions
65 */
66
Andrew Morgane338d262008-02-04 22:29:42 -080067# define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050068 | CAP_TO_MASK(CAP_MKNOD) \
Andrew Morgane338d262008-02-04 22:29:42 -080069 | CAP_TO_MASK(CAP_DAC_OVERRIDE) \
70 | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \
71 | CAP_TO_MASK(CAP_FOWNER) \
72 | CAP_TO_MASK(CAP_FSETID))
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Casey Schauflere114e472008-02-04 22:29:50 -080074# define CAP_FS_MASK_B1 (CAP_TO_MASK(CAP_MAC_OVERRIDE))
75
Andrew G. Morganca05a992008-05-27 22:05:17 -070076#if _KERNEL_CAPABILITY_U32S != 2
Andrew Morgane338d262008-02-04 22:29:42 -080077# error Fix up hand-coded capability macro initializers
78#else /* HAND-CODED capability initializers */
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Eric Paris7d8b6c62014-07-23 15:36:26 -040080#define CAP_LAST_U32 ((_KERNEL_CAPABILITY_U32S) - 1)
81#define CAP_LAST_U32_VALID_MASK (CAP_TO_MASK(CAP_LAST_CAP + 1) -1)
82
David Howells25f2ea92008-04-29 20:54:28 +010083# define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }})
Eric Paris7d8b6c62014-07-23 15:36:26 -040084# define CAP_FULL_SET ((kernel_cap_t){{ ~0, CAP_LAST_U32_VALID_MASK }})
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050085# define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
86 | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
87 CAP_FS_MASK_B1 } })
J. Bruce Fields76a67ec2009-03-16 18:34:20 -040088# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050089 | CAP_TO_MASK(CAP_SYS_RESOURCE), \
90 CAP_FS_MASK_B1 } })
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
Andrew G. Morganca05a992008-05-27 22:05:17 -070092#endif /* _KERNEL_CAPABILITY_U32S != 2 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
Andrew Morgane338d262008-02-04 22:29:42 -080094# define cap_clear(c) do { (c) = __cap_empty_set; } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Andrew Morgane338d262008-02-04 22:29:42 -080096#define cap_raise(c, flag) ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag))
97#define cap_lower(c, flag) ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag))
98#define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag))
99
100#define CAP_BOP_ALL(c, a, b, OP) \
101do { \
102 unsigned __capi; \
103 CAP_FOR_EACH_U32(__capi) { \
104 c.cap[__capi] = a.cap[__capi] OP b.cap[__capi]; \
105 } \
106} while (0)
107
108#define CAP_UOP_ALL(c, a, OP) \
109do { \
110 unsigned __capi; \
111 CAP_FOR_EACH_U32(__capi) { \
112 c.cap[__capi] = OP a.cap[__capi]; \
113 } \
114} while (0)
115
116static inline kernel_cap_t cap_combine(const kernel_cap_t a,
117 const kernel_cap_t b)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118{
Andrew Morgane338d262008-02-04 22:29:42 -0800119 kernel_cap_t dest;
120 CAP_BOP_ALL(dest, a, b, |);
121 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122}
123
Andrew Morgane338d262008-02-04 22:29:42 -0800124static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
125 const kernel_cap_t b)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126{
Andrew Morgane338d262008-02-04 22:29:42 -0800127 kernel_cap_t dest;
128 CAP_BOP_ALL(dest, a, b, &);
129 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130}
131
Andrew Morgane338d262008-02-04 22:29:42 -0800132static inline kernel_cap_t cap_drop(const kernel_cap_t a,
133 const kernel_cap_t drop)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134{
Andrew Morgane338d262008-02-04 22:29:42 -0800135 kernel_cap_t dest;
136 CAP_BOP_ALL(dest, a, drop, &~);
137 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138}
139
Andrew Morgane338d262008-02-04 22:29:42 -0800140static inline kernel_cap_t cap_invert(const kernel_cap_t c)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141{
Andrew Morgane338d262008-02-04 22:29:42 -0800142 kernel_cap_t dest;
143 CAP_UOP_ALL(dest, c, ~);
144 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145}
146
Yaowei Baie42852bf2015-11-17 15:25:24 +0800147static inline bool cap_isclear(const kernel_cap_t a)
Andrew Morgane338d262008-02-04 22:29:42 -0800148{
149 unsigned __capi;
150 CAP_FOR_EACH_U32(__capi) {
151 if (a.cap[__capi] != 0)
Yaowei Baie42852bf2015-11-17 15:25:24 +0800152 return false;
Andrew Morgane338d262008-02-04 22:29:42 -0800153 }
Yaowei Baie42852bf2015-11-17 15:25:24 +0800154 return true;
Andrew Morgane338d262008-02-04 22:29:42 -0800155}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
Eric Paris9d36be72008-11-11 21:48:07 +1100157/*
158 * Check if "a" is a subset of "set".
Yaowei Baie42852bf2015-11-17 15:25:24 +0800159 * return true if ALL of the capabilities in "a" are also in "set"
160 * cap_issubset(0101, 1111) will return true
161 * return false if ANY of the capabilities in "a" are not in "set"
162 * cap_issubset(1111, 0101) will return false
Eric Paris9d36be72008-11-11 21:48:07 +1100163 */
Yaowei Baie42852bf2015-11-17 15:25:24 +0800164static inline bool cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
Andrew Morgane338d262008-02-04 22:29:42 -0800165{
166 kernel_cap_t dest;
167 dest = cap_drop(a, set);
168 return cap_isclear(dest);
169}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Andrew Morgane338d262008-02-04 22:29:42 -0800171/* Used to decide between falling back on the old suser() or fsuser(). */
172
Andrew Morgane338d262008-02-04 22:29:42 -0800173static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)
174{
175 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
176 return cap_drop(a, __cap_fs_set);
177}
178
179static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,
180 const kernel_cap_t permitted)
181{
182 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
183 return cap_combine(a,
184 cap_intersect(permitted, __cap_fs_set));
185}
186
187static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)
188{
189 const kernel_cap_t __cap_fs_set = CAP_NFSD_SET;
190 return cap_drop(a, __cap_fs_set);
191}
192
193static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,
194 const kernel_cap_t permitted)
195{
196 const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET;
197 return cap_combine(a,
198 cap_intersect(permitted, __cap_nfsd_set));
199}
200
Iulia Manda28138932015-04-15 16:16:41 -0700201#ifdef CONFIG_MULTIUSER
Serge E. Hallyn32632452011-03-23 16:43:21 -0700202extern bool has_capability(struct task_struct *t, int cap);
203extern bool has_ns_capability(struct task_struct *t,
204 struct user_namespace *ns, int cap);
205extern bool has_capability_noaudit(struct task_struct *t, int cap);
Eric Paris7b61d642012-01-03 12:25:15 -0500206extern bool has_ns_capability_noaudit(struct task_struct *t,
207 struct user_namespace *ns, int cap);
Serge E. Hallyn34867402011-03-23 16:43:17 -0700208extern bool capable(int cap);
209extern bool ns_capable(struct user_namespace *ns, int cap);
Tyler Hicks98f368e2016-06-02 23:43:21 -0500210extern bool ns_capable_noaudit(struct user_namespace *ns, int cap);
Iulia Manda28138932015-04-15 16:16:41 -0700211#else
212static inline bool has_capability(struct task_struct *t, int cap)
213{
214 return true;
215}
216static inline bool has_ns_capability(struct task_struct *t,
217 struct user_namespace *ns, int cap)
218{
219 return true;
220}
221static inline bool has_capability_noaudit(struct task_struct *t, int cap)
222{
223 return true;
224}
225static inline bool has_ns_capability_noaudit(struct task_struct *t,
226 struct user_namespace *ns, int cap)
227{
228 return true;
229}
230static inline bool capable(int cap)
231{
232 return true;
233}
234static inline bool ns_capable(struct user_namespace *ns, int cap)
235{
236 return true;
237}
Tyler Hicks98f368e2016-06-02 23:43:21 -0500238static inline bool ns_capable_noaudit(struct user_namespace *ns, int cap)
239{
240 return true;
241}
Iulia Manda28138932015-04-15 16:16:41 -0700242#endif /* CONFIG_MULTIUSER */
Andy Lutomirski23adbe12014-06-10 12:45:42 -0700243extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap);
Linus Torvalds935d8aa2013-04-14 10:06:31 -0700244extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap);
Randy.Dunlapc59ede72006-01-11 12:17:46 -0800245
Eric Paris851f7ff2008-11-11 21:48:14 +1100246/* audit system wants to get cap info from files as well */
Eric Paris851f7ff2008-11-11 21:48:14 +1100247extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249#endif /* !_LINUX_CAPABILITY_H */