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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;
41struct user_namespace;
42
Serge E. Hallyn34867402011-03-23 16:43:17 -070043struct user_namespace *current_user_ns(void);
44
45extern const kernel_cap_t __cap_empty_set;
Serge E. Hallyn34867402011-03-23 16:43:17 -070046extern const kernel_cap_t __cap_init_eff_set;
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048/*
49 * Internal kernel functions only
50 */
Serge E. Hallynb5376772007-10-16 23:31:36 -070051
Andrew Morgane338d262008-02-04 22:29:42 -080052#define CAP_FOR_EACH_U32(__capi) \
Andrew G. Morganca05a992008-05-27 22:05:17 -070053 for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050055/*
56 * CAP_FS_MASK and CAP_NFSD_MASKS:
57 *
58 * The fs mask is all the privileges that fsuid==0 historically meant.
59 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.
60 *
61 * It has never meant setting security.* and trusted.* xattrs.
62 *
63 * We could also define fsmask as follows:
64 * 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions
65 * 2. The security.* and trusted.* xattrs are fs-related MAC permissions
66 */
67
Andrew Morgane338d262008-02-04 22:29:42 -080068# define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050069 | CAP_TO_MASK(CAP_MKNOD) \
Andrew Morgane338d262008-02-04 22:29:42 -080070 | CAP_TO_MASK(CAP_DAC_OVERRIDE) \
71 | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \
72 | CAP_TO_MASK(CAP_FOWNER) \
73 | CAP_TO_MASK(CAP_FSETID))
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Casey Schauflere114e472008-02-04 22:29:50 -080075# define CAP_FS_MASK_B1 (CAP_TO_MASK(CAP_MAC_OVERRIDE))
76
Andrew G. Morganca05a992008-05-27 22:05:17 -070077#if _KERNEL_CAPABILITY_U32S != 2
Andrew Morgane338d262008-02-04 22:29:42 -080078# error Fix up hand-coded capability macro initializers
79#else /* HAND-CODED capability initializers */
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Eric Paris7d8b6c62014-07-23 15:36:26 -040081#define CAP_LAST_U32 ((_KERNEL_CAPABILITY_U32S) - 1)
82#define CAP_LAST_U32_VALID_MASK (CAP_TO_MASK(CAP_LAST_CAP + 1) -1)
83
David Howells25f2ea92008-04-29 20:54:28 +010084# define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }})
Eric Paris7d8b6c62014-07-23 15:36:26 -040085# define CAP_FULL_SET ((kernel_cap_t){{ ~0, CAP_LAST_U32_VALID_MASK }})
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050086# define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
87 | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
88 CAP_FS_MASK_B1 } })
J. Bruce Fields76a67ec2009-03-16 18:34:20 -040089# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
Serge E. Hallyn0ad30b82009-04-13 09:56:14 -050090 | CAP_TO_MASK(CAP_SYS_RESOURCE), \
91 CAP_FS_MASK_B1 } })
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
Andrew G. Morganca05a992008-05-27 22:05:17 -070093#endif /* _KERNEL_CAPABILITY_U32S != 2 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
Andrew Morgane338d262008-02-04 22:29:42 -080095# define cap_clear(c) do { (c) = __cap_empty_set; } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
Andrew Morgane338d262008-02-04 22:29:42 -080097#define cap_raise(c, flag) ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag))
98#define cap_lower(c, flag) ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag))
99#define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag))
100
101#define CAP_BOP_ALL(c, a, b, OP) \
102do { \
103 unsigned __capi; \
104 CAP_FOR_EACH_U32(__capi) { \
105 c.cap[__capi] = a.cap[__capi] OP b.cap[__capi]; \
106 } \
107} while (0)
108
109#define CAP_UOP_ALL(c, a, OP) \
110do { \
111 unsigned __capi; \
112 CAP_FOR_EACH_U32(__capi) { \
113 c.cap[__capi] = OP a.cap[__capi]; \
114 } \
115} while (0)
116
117static inline kernel_cap_t cap_combine(const kernel_cap_t a,
118 const kernel_cap_t b)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
Andrew Morgane338d262008-02-04 22:29:42 -0800120 kernel_cap_t dest;
121 CAP_BOP_ALL(dest, a, b, |);
122 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123}
124
Andrew Morgane338d262008-02-04 22:29:42 -0800125static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
126 const kernel_cap_t b)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127{
Andrew Morgane338d262008-02-04 22:29:42 -0800128 kernel_cap_t dest;
129 CAP_BOP_ALL(dest, a, b, &);
130 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131}
132
Andrew Morgane338d262008-02-04 22:29:42 -0800133static inline kernel_cap_t cap_drop(const kernel_cap_t a,
134 const kernel_cap_t drop)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135{
Andrew Morgane338d262008-02-04 22:29:42 -0800136 kernel_cap_t dest;
137 CAP_BOP_ALL(dest, a, drop, &~);
138 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139}
140
Andrew Morgane338d262008-02-04 22:29:42 -0800141static inline kernel_cap_t cap_invert(const kernel_cap_t c)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
Andrew Morgane338d262008-02-04 22:29:42 -0800143 kernel_cap_t dest;
144 CAP_UOP_ALL(dest, c, ~);
145 return dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146}
147
Andrew Morgane338d262008-02-04 22:29:42 -0800148static inline int cap_isclear(const kernel_cap_t a)
149{
150 unsigned __capi;
151 CAP_FOR_EACH_U32(__capi) {
152 if (a.cap[__capi] != 0)
153 return 0;
154 }
155 return 1;
156}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Eric Paris9d36be72008-11-11 21:48:07 +1100158/*
159 * Check if "a" is a subset of "set".
160 * return 1 if ALL of the capabilities in "a" are also in "set"
161 * cap_issubset(0101, 1111) will return 1
162 * return 0 if ANY of the capabilities in "a" are not in "set"
163 * cap_issubset(1111, 0101) will return 0
164 */
Andrew Morgane338d262008-02-04 22:29:42 -0800165static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
166{
167 kernel_cap_t dest;
168 dest = cap_drop(a, set);
169 return cap_isclear(dest);
170}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
Andrew Morgane338d262008-02-04 22:29:42 -0800172/* Used to decide between falling back on the old suser() or fsuser(). */
173
174static inline int cap_is_fs_cap(int cap)
175{
176 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
177 return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]);
178}
179
180static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)
181{
182 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
183 return cap_drop(a, __cap_fs_set);
184}
185
186static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,
187 const kernel_cap_t permitted)
188{
189 const kernel_cap_t __cap_fs_set = CAP_FS_SET;
190 return cap_combine(a,
191 cap_intersect(permitted, __cap_fs_set));
192}
193
194static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)
195{
196 const kernel_cap_t __cap_fs_set = CAP_NFSD_SET;
197 return cap_drop(a, __cap_fs_set);
198}
199
200static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,
201 const kernel_cap_t permitted)
202{
203 const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET;
204 return cap_combine(a,
205 cap_intersect(permitted, __cap_nfsd_set));
206}
207
Iulia Manda28138932015-04-15 16:16:41 -0700208#ifdef CONFIG_MULTIUSER
Serge E. Hallyn32632452011-03-23 16:43:21 -0700209extern bool has_capability(struct task_struct *t, int cap);
210extern bool has_ns_capability(struct task_struct *t,
211 struct user_namespace *ns, int cap);
212extern bool has_capability_noaudit(struct task_struct *t, int cap);
Eric Paris7b61d642012-01-03 12:25:15 -0500213extern bool has_ns_capability_noaudit(struct task_struct *t,
214 struct user_namespace *ns, int cap);
Serge E. Hallyn34867402011-03-23 16:43:17 -0700215extern bool capable(int cap);
216extern bool ns_capable(struct user_namespace *ns, int cap);
Iulia Manda28138932015-04-15 16:16:41 -0700217#else
218static inline bool has_capability(struct task_struct *t, int cap)
219{
220 return true;
221}
222static inline bool has_ns_capability(struct task_struct *t,
223 struct user_namespace *ns, int cap)
224{
225 return true;
226}
227static inline bool has_capability_noaudit(struct task_struct *t, int cap)
228{
229 return true;
230}
231static inline bool has_ns_capability_noaudit(struct task_struct *t,
232 struct user_namespace *ns, int cap)
233{
234 return true;
235}
236static inline bool capable(int cap)
237{
238 return true;
239}
240static inline bool ns_capable(struct user_namespace *ns, int cap)
241{
242 return true;
243}
244#endif /* CONFIG_MULTIUSER */
Andy Lutomirski23adbe12014-06-10 12:45:42 -0700245extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap);
Linus Torvalds935d8aa2013-04-14 10:06:31 -0700246extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap);
Randy.Dunlapc59ede72006-01-11 12:17:46 -0800247
Eric Paris851f7ff2008-11-11 21:48:14 +1100248/* audit system wants to get cap info from files as well */
Eric Paris851f7ff2008-11-11 21:48:14 +1100249extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);
250
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251#endif /* !_LINUX_CAPABILITY_H */