diff options
Diffstat (limited to 'include/linux/capability.h')
| -rw-r--r-- | include/linux/capability.h | 221 |
1 files changed, 155 insertions, 66 deletions
diff --git a/include/linux/capability.h b/include/linux/capability.h index 7a8d7ade28a0..a934dac672dd 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -23,13 +23,20 @@ struct task_struct; kernel might be somewhat backwards compatible, but don't bet on it. */ -/* XXX - Note, cap_t, is defined by POSIX to be an "opaque" pointer to +/* Note, cap_t, is defined by POSIX (draft) to be an "opaque" pointer to a set of three capability sets. The transposition of 3*the following structure to such a composite is better handled in a user library since the draft standard requires the use of malloc/free etc.. */ -#define _LINUX_CAPABILITY_VERSION 0x19980330 +#define _LINUX_CAPABILITY_VERSION_1 0x19980330 +#define _LINUX_CAPABILITY_U32S_1 1 + +#define _LINUX_CAPABILITY_VERSION_2 0x20071026 +#define _LINUX_CAPABILITY_U32S_2 2 + +#define _LINUX_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_2 +#define _LINUX_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_2 typedef struct __user_cap_header_struct { __u32 version; @@ -42,43 +49,42 @@ typedef struct __user_cap_data_struct { __u32 inheritable; } __user *cap_user_data_t; + #define XATTR_CAPS_SUFFIX "capability" #define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX -#define XATTR_CAPS_SZ (3*sizeof(__le32)) #define VFS_CAP_REVISION_MASK 0xFF000000 +#define VFS_CAP_FLAGS_MASK ~VFS_CAP_REVISION_MASK +#define VFS_CAP_FLAGS_EFFECTIVE 0x000001 + #define VFS_CAP_REVISION_1 0x01000000 +#define VFS_CAP_U32_1 1 +#define XATTR_CAPS_SZ_1 (sizeof(__le32)*(1 + 2*VFS_CAP_U32_1)) -#define VFS_CAP_REVISION VFS_CAP_REVISION_1 +#define VFS_CAP_REVISION_2 0x02000000 +#define VFS_CAP_U32_2 2 +#define XATTR_CAPS_SZ_2 (sizeof(__le32)*(1 + 2*VFS_CAP_U32_2)) + +#define XATTR_CAPS_SZ XATTR_CAPS_SZ_2 +#define VFS_CAP_U32 VFS_CAP_U32_2 +#define VFS_CAP_REVISION VFS_CAP_REVISION_2 -#define VFS_CAP_FLAGS_MASK ~VFS_CAP_REVISION_MASK -#define VFS_CAP_FLAGS_EFFECTIVE 0x000001 struct vfs_cap_data { - __u32 magic_etc; /* Little endian */ + __le32 magic_etc; /* Little endian */ struct { - __u32 permitted; /* Little endian */ - __u32 inheritable; /* Little endian */ - } data[1]; + __le32 permitted; /* Little endian */ + __le32 inheritable; /* Little endian */ + } data[VFS_CAP_U32]; }; #ifdef __KERNEL__ -/* #define STRICT_CAP_T_TYPECHECKS */ - -#ifdef STRICT_CAP_T_TYPECHECKS - typedef struct kernel_cap_struct { - __u32 cap; + __u32 cap[_LINUX_CAPABILITY_U32S]; } kernel_cap_t; -#else - -typedef __u32 kernel_cap_t; - -#endif - -#define _USER_CAP_HEADER_SIZE (2*sizeof(__u32)) +#define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct)) #define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t)) #endif @@ -121,10 +127,6 @@ typedef __u32 kernel_cap_t; #define CAP_FSETID 4 -/* Used to decide between falling back on the old suser() or fsuser(). */ - -#define CAP_FS_MASK 0x1f - /* Overrides the restriction that the real or effective user ID of a process sending a signal must match the real or effective user ID of the process receiving the signal. */ @@ -147,8 +149,12 @@ typedef __u32 kernel_cap_t; ** Linux-specific capabilities **/ -/* Transfer any capability in your permitted set to any pid, - remove any capability in your permitted set from any pid */ +/* Without VFS support for capabilities: + * Transfer any capability in your permitted set to any pid, + * remove any capability in your permitted set from any pid + * With VFS support for capabilities (neither of above, but) + * Add any capability to the current process' inheritable set + */ #define CAP_SETPCAP 8 @@ -309,70 +315,153 @@ typedef __u32 kernel_cap_t; #define CAP_SETFCAP 31 +/* + * Bit location of each capability (used by user-space library and kernel) + */ + +#define CAP_TO_INDEX(x) ((x) >> 5) /* 1 << 5 == bits in __u32 */ +#define CAP_TO_MASK(x) (1 << ((x) & 31)) /* mask for indexed __u32 */ + #ifdef __KERNEL__ /* * Internal kernel functions only */ -#ifdef STRICT_CAP_T_TYPECHECKS +#define CAP_FOR_EACH_U32(__capi) \ + for (__capi = 0; __capi < _LINUX_CAPABILITY_U32S; ++__capi) + +# define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \ + | CAP_TO_MASK(CAP_DAC_OVERRIDE) \ + | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \ + | CAP_TO_MASK(CAP_FOWNER) \ + | CAP_TO_MASK(CAP_FSETID)) + +#if _LINUX_CAPABILITY_U32S != 2 +# error Fix up hand-coded capability macro initializers +#else /* HAND-CODED capability initializers */ + +# define CAP_EMPTY_SET {{ 0, 0 }} +# define CAP_FULL_SET {{ ~0, ~0 }} +# define CAP_INIT_EFF_SET {{ ~CAP_TO_MASK(CAP_SETPCAP), ~0 }} +# define CAP_FS_SET {{ CAP_FS_MASK_B0, 0 }} +# define CAP_NFSD_SET {{ CAP_FS_MASK_B0|CAP_TO_MASK(CAP_SYS_RESOURCE), 0 }} + +#endif /* _LINUX_CAPABILITY_U32S != 2 */ + +#define CAP_INIT_INH_SET CAP_EMPTY_SET + +# define cap_clear(c) do { (c) = __cap_empty_set; } while (0) +# define cap_set_full(c) do { (c) = __cap_full_set; } while (0) +# define cap_set_init_eff(c) do { (c) = __cap_init_eff_set; } while (0) + +#define cap_raise(c, flag) ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag)) +#define cap_lower(c, flag) ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag)) +#define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag)) + +#define CAP_BOP_ALL(c, a, b, OP) \ +do { \ + unsigned __capi; \ + CAP_FOR_EACH_U32(__capi) { \ + c.cap[__capi] = a.cap[__capi] OP b.cap[__capi]; \ + } \ +} while (0) + +#define CAP_UOP_ALL(c, a, OP) \ +do { \ + unsigned __capi; \ + CAP_FOR_EACH_U32(__capi) { \ + c.cap[__capi] = OP a.cap[__capi]; \ + } \ +} while (0) + +static inline kernel_cap_t cap_combine(const kernel_cap_t a, + const kernel_cap_t b) +{ + kernel_cap_t dest; + CAP_BOP_ALL(dest, a, b, |); + return dest; +} -#define to_cap_t(x) { x } -#define cap_t(x) (x).cap +static inline kernel_cap_t cap_intersect(const kernel_cap_t a, + const kernel_cap_t b) +{ + kernel_cap_t dest; + CAP_BOP_ALL(dest, a, b, &); + return dest; +} -#else +static inline kernel_cap_t cap_drop(const kernel_cap_t a, + const kernel_cap_t drop) +{ + kernel_cap_t dest; + CAP_BOP_ALL(dest, a, drop, &~); + return dest; +} -#define to_cap_t(x) (x) -#define cap_t(x) (x) +static inline kernel_cap_t cap_invert(const kernel_cap_t c) +{ + kernel_cap_t dest; + CAP_UOP_ALL(dest, c, ~); + return dest; +} -#endif +static inline int cap_isclear(const kernel_cap_t a) +{ + unsigned __capi; + CAP_FOR_EACH_U32(__capi) { + if (a.cap[__capi] != 0) + return 0; + } + return 1; +} -#define CAP_EMPTY_SET to_cap_t(0) -#define CAP_FULL_SET to_cap_t(~0) -#define CAP_INIT_EFF_SET to_cap_t(~0 & ~CAP_TO_MASK(CAP_SETPCAP)) -#define CAP_INIT_INH_SET to_cap_t(0) +static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set) +{ + kernel_cap_t dest; + dest = cap_drop(a, set); + return cap_isclear(dest); +} -#define CAP_TO_MASK(x) (1 << (x)) -#define cap_raise(c, flag) (cap_t(c) |= CAP_TO_MASK(flag)) -#define cap_lower(c, flag) (cap_t(c) &= ~CAP_TO_MASK(flag)) -#define cap_raised(c, flag) (cap_t(c) & CAP_TO_MASK(flag)) +/* Used to decide between falling back on the old suser() or fsuser(). */ -static inline kernel_cap_t cap_combine(kernel_cap_t a, kernel_cap_t b) +static inline int cap_is_fs_cap(int cap) { - kernel_cap_t dest; - cap_t(dest) = cap_t(a) | cap_t(b); - return dest; + const kernel_cap_t __cap_fs_set = CAP_FS_SET; + return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]); } -static inline kernel_cap_t cap_intersect(kernel_cap_t a, kernel_cap_t b) +static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a) { - kernel_cap_t dest; - cap_t(dest) = cap_t(a) & cap_t(b); - return dest; + const kernel_cap_t __cap_fs_set = CAP_FS_SET; + return cap_drop(a, __cap_fs_set); } -static inline kernel_cap_t cap_drop(kernel_cap_t a, kernel_cap_t drop) +static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a, + const kernel_cap_t permitted) { - kernel_cap_t dest; - cap_t(dest) = cap_t(a) & ~cap_t(drop); - return dest; + const kernel_cap_t __cap_fs_set = CAP_FS_SET; + return cap_combine(a, + cap_intersect(permitted, __cap_fs_set)); } -static inline kernel_cap_t cap_invert(kernel_cap_t c) +static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a) { - kernel_cap_t dest; - cap_t(dest) = ~cap_t(c); - return dest; + const kernel_cap_t __cap_fs_set = CAP_NFSD_SET; + return cap_drop(a, __cap_fs_set); } -#define cap_isclear(c) (!cap_t(c)) -#define cap_issubset(a,set) (!(cap_t(a) & ~cap_t(set))) - -#define cap_clear(c) do { cap_t(c) = 0; } while(0) -#define cap_set_full(c) do { cap_t(c) = ~0; } while(0) -#define cap_mask(c,mask) do { cap_t(c) &= cap_t(mask); } while(0) +static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a, + const kernel_cap_t permitted) +{ + const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET; + return cap_combine(a, + cap_intersect(permitted, __cap_nfsd_set)); +} -#define cap_is_fs_cap(c) (CAP_TO_MASK(c) & CAP_FS_MASK) +extern const kernel_cap_t __cap_empty_set; +extern const kernel_cap_t __cap_full_set; +extern const kernel_cap_t __cap_init_eff_set; int capable(int cap); int __capable(struct task_struct *t, int cap); |
