Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/include/linux/capability.h

  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 #ifndef _LINUX_CAPABILITY_H
 13 #define _LINUX_CAPABILITY_H
 14 
 15 #include <uapi/linux/capability.h>
 16 
 17 
 18 #define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3
 19 #define _KERNEL_CAPABILITY_U32S    _LINUX_CAPABILITY_U32S_3
 20 
 21 extern int file_caps_enabled;
 22 
 23 typedef struct kernel_cap_struct {
 24         __u32 cap[_KERNEL_CAPABILITY_U32S];
 25 } kernel_cap_t;
 26 
 27 /* exact same as vfs_cap_data but in cpu endian and always filled completely */
 28 struct cpu_vfs_cap_data {
 29         __u32 magic_etc;
 30         kernel_cap_t permitted;
 31         kernel_cap_t inheritable;
 32 };
 33 
 34 #define _USER_CAP_HEADER_SIZE  (sizeof(struct __user_cap_header_struct))
 35 #define _KERNEL_CAP_T_SIZE     (sizeof(kernel_cap_t))
 36 
 37 
 38 struct file;
 39 struct inode;
 40 struct dentry;
 41 struct task_struct;
 42 struct user_namespace;
 43 
 44 extern const kernel_cap_t __cap_empty_set;
 45 extern const kernel_cap_t __cap_init_eff_set;
 46 
 47 /*
 48  * Internal kernel functions only
 49  */
 50 
 51 #define CAP_FOR_EACH_U32(__capi)  \
 52         for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)
 53 
 54 /*
 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 
 67 # define CAP_FS_MASK_B0     (CAP_TO_MASK(CAP_CHOWN)             \
 68                             | CAP_TO_MASK(CAP_MKNOD)            \
 69                             | 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))
 73 
 74 # define CAP_FS_MASK_B1     (CAP_TO_MASK(CAP_MAC_OVERRIDE))
 75 
 76 #if _KERNEL_CAPABILITY_U32S != 2
 77 # error Fix up hand-coded capability macro initializers
 78 #else /* HAND-CODED capability initializers */
 79 
 80 #define CAP_LAST_U32                    ((_KERNEL_CAPABILITY_U32S) - 1)
 81 #define CAP_LAST_U32_VALID_MASK         (CAP_TO_MASK(CAP_LAST_CAP + 1) -1)
 82 
 83 # define CAP_EMPTY_SET    ((kernel_cap_t){{ 0, 0 }})
 84 # define CAP_FULL_SET     ((kernel_cap_t){{ ~0, CAP_LAST_U32_VALID_MASK }})
 85 # define CAP_FS_SET       ((kernel_cap_t){{ CAP_FS_MASK_B0 \
 86                                     | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
 87                                     CAP_FS_MASK_B1 } })
 88 # define CAP_NFSD_SET     ((kernel_cap_t){{ CAP_FS_MASK_B0 \
 89                                     | CAP_TO_MASK(CAP_SYS_RESOURCE), \
 90                                     CAP_FS_MASK_B1 } })
 91 
 92 #endif /* _KERNEL_CAPABILITY_U32S != 2 */
 93 
 94 # define cap_clear(c)         do { (c) = __cap_empty_set; } while (0)
 95 
 96 #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)                                    \
101 do {                                                                \
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)                                       \
109 do {                                                                \
110         unsigned __capi;                                            \
111         CAP_FOR_EACH_U32(__capi) {                                  \
112                 c.cap[__capi] = OP a.cap[__capi];                   \
113         }                                                           \
114 } while (0)
115 
116 static inline kernel_cap_t cap_combine(const kernel_cap_t a,
117                                        const kernel_cap_t b)
118 {
119         kernel_cap_t dest;
120         CAP_BOP_ALL(dest, a, b, |);
121         return dest;
122 }
123 
124 static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
125                                          const kernel_cap_t b)
126 {
127         kernel_cap_t dest;
128         CAP_BOP_ALL(dest, a, b, &);
129         return dest;
130 }
131 
132 static inline kernel_cap_t cap_drop(const kernel_cap_t a,
133                                     const kernel_cap_t drop)
134 {
135         kernel_cap_t dest;
136         CAP_BOP_ALL(dest, a, drop, &~);
137         return dest;
138 }
139 
140 static inline kernel_cap_t cap_invert(const kernel_cap_t c)
141 {
142         kernel_cap_t dest;
143         CAP_UOP_ALL(dest, c, ~);
144         return dest;
145 }
146 
147 static inline bool cap_isclear(const kernel_cap_t a)
148 {
149         unsigned __capi;
150         CAP_FOR_EACH_U32(__capi) {
151                 if (a.cap[__capi] != 0)
152                         return false;
153         }
154         return true;
155 }
156 
157 /*
158  * Check if "a" is a subset of "set".
159  * 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
163  */
164 static inline bool cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
165 {
166         kernel_cap_t dest;
167         dest = cap_drop(a, set);
168         return cap_isclear(dest);
169 }
170 
171 /* Used to decide between falling back on the old suser() or fsuser(). */
172 
173 static 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 
179 static 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 
187 static 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 
193 static 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 
201 #ifdef CONFIG_MULTIUSER
202 extern bool has_capability(struct task_struct *t, int cap);
203 extern bool has_ns_capability(struct task_struct *t,
204                               struct user_namespace *ns, int cap);
205 extern bool has_capability_noaudit(struct task_struct *t, int cap);
206 extern bool has_ns_capability_noaudit(struct task_struct *t,
207                                       struct user_namespace *ns, int cap);
208 extern bool capable(int cap);
209 extern bool ns_capable(struct user_namespace *ns, int cap);
210 extern bool ns_capable_noaudit(struct user_namespace *ns, int cap);
211 #else
212 static inline bool has_capability(struct task_struct *t, int cap)
213 {
214         return true;
215 }
216 static inline bool has_ns_capability(struct task_struct *t,
217                               struct user_namespace *ns, int cap)
218 {
219         return true;
220 }
221 static inline bool has_capability_noaudit(struct task_struct *t, int cap)
222 {
223         return true;
224 }
225 static inline bool has_ns_capability_noaudit(struct task_struct *t,
226                                       struct user_namespace *ns, int cap)
227 {
228         return true;
229 }
230 static inline bool capable(int cap)
231 {
232         return true;
233 }
234 static inline bool ns_capable(struct user_namespace *ns, int cap)
235 {
236         return true;
237 }
238 static inline bool ns_capable_noaudit(struct user_namespace *ns, int cap)
239 {
240         return true;
241 }
242 #endif /* CONFIG_MULTIUSER */
243 extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap);
244 extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap);
245 
246 /* audit system wants to get cap info from files as well */
247 extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);
248 
249 #endif /* !_LINUX_CAPABILITY_H */
250 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us