/* SPDX-License-Identifier: GPL-2.0 */ /* * This is <linux/capability.h> * * Andrew G. Morgan <morgan@kernel.org> * Alexander Kjeldaas <astor@guardian.no> * with help from Aleph1, Roland Buresund and Andrew Main. * * See here for the libcap library ("POSIX draft" compliance): * * ftp://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/ */ #ifndef _LINUX_CAPABILITY_H #define _LINUX_CAPABILITY_H #include <uapi/linux/capability.h> #include <linux/uidgid.h> #define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3 #define _KERNEL_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3 extern int file_caps_enabled; typedef struct kernel_cap_struct { __u32 cap[_KERNEL_CAPABILITY_U32S]; } kernel_cap_t; /* same as vfs_ns_cap_data but in cpu endian and always filled completely */ struct cpu_vfs_cap_data { __u32 magic_etc; kernel_cap_t permitted; kernel_cap_t inheritable; kuid_t rootid; }; #define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct)) #define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t)) struct file; struct inode; struct dentry; struct task_struct; struct user_namespace; extern const kernel_cap_t __cap_empty_set; extern const kernel_cap_t __cap_init_eff_set; /* * Internal kernel functions only */ #define CAP_FOR_EACH_U32(__capi) \ for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi) /* * CAP_FS_MASK and CAP_NFSD_MASKS: * * The fs mask is all the privileges that fsuid==0 historically meant. * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE. * * It has never meant setting security.* and trusted.* xattrs. * * We could also define fsmask as follows: * 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions * 2. The security.* and trusted.* xattrs are fs-related MAC permissions */ # define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \ | CAP_TO_MASK(CAP_MKNOD) \ | CAP_TO_MASK(CAP_DAC_OVERRIDE) \ | CAP_TO_MASK(CAP_DAC_READ_SEARCH) \ | CAP_TO_MASK(CAP_FOWNER) \ | CAP_TO_MASK(CAP_FSETID)) # define CAP_FS_MASK_B1 (CAP_TO_MASK(CAP_MAC_OVERRIDE)) #if _KERNEL_CAPABILITY_U32S != 2 # error Fix up hand-coded capability macro initializers #else /* HAND-CODED capability initializers */ #define CAP_LAST_U32 ((_KERNEL_CAPABILITY_U32S) - 1) #define CAP_LAST_U32_VALID_MASK (CAP_TO_MASK(CAP_LAST_CAP + 1) -1) # define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }}) # define CAP_FULL_SET ((kernel_cap_t){{ ~0, CAP_LAST_U32_VALID_MASK }}) # define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \ | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \ CAP_FS_MASK_B1 } }) # define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \ | CAP_TO_MASK(CAP_SYS_RESOURCE), \ CAP_FS_MASK_B1 } }) #endif /* _KERNEL_CAPABILITY_U32S != 2 */ # define cap_clear(c) do { (c) = __cap_empty_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; } 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; } 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; } static inline kernel_cap_t cap_invert(const kernel_cap_t c) { kernel_cap_t dest; CAP_UOP_ALL(dest, c, ~); return dest; } static inline bool cap_isclear(const kernel_cap_t a) { unsigned __capi; CAP_FOR_EACH_U32(__capi) { if (a.cap[__capi] != 0) return false; } return true; } /* * Check if "a" is a subset of "set". * return true if ALL of the capabilities in "a" are also in "set" * cap_issubset(0101, 1111) will return true * return false if ANY of the capabilities in "a" are not in "set" * cap_issubset(1111, 0101) will return false */ static inline bool 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); } /* Used to decide between falling back on the old suser() or fsuser(). */ static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a) { const kernel_cap_t __cap_fs_set = CAP_FS_SET; return cap_drop(a, __cap_fs_set); } static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a, const kernel_cap_t permitted) { 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_drop_nfsd_set(const kernel_cap_t a) { const kernel_cap_t __cap_fs_set = CAP_NFSD_SET; return cap_drop(a, __cap_fs_set); } 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)); } #ifdef CONFIG_MULTIUSER extern bool has_capability(struct task_struct *t, int cap); extern bool has_ns_capability(struct task_struct *t, struct user_namespace *ns, int cap); extern bool has_capability_noaudit(struct task_struct *t, int cap); extern bool has_ns_capability_noaudit(struct task_struct *t, struct user_namespace *ns, int cap); extern bool capable(int cap); extern bool ns_capable(struct user_namespace *ns, int cap); extern bool ns_capable_noaudit(struct user_namespace *ns, int cap); extern bool ns_capable_setid(struct user_namespace *ns, int cap); #else static inline bool has_capability(struct task_struct *t, int cap) { return true; } static inline bool has_ns_capability(struct task_struct *t, struct user_namespace *ns, int cap) { return true; } static inline bool has_capability_noaudit(struct task_struct *t, int cap) { return true; } static inline bool has_ns_capability_noaudit(struct task_struct *t, struct user_namespace *ns, int cap) { return true; } static inline bool capable(int cap) { return true; } static inline bool ns_capable(struct user_namespace *ns, int cap) { return true; } static inline bool ns_capable_noaudit(struct user_namespace *ns, int cap) { return true; } static inline bool ns_capable_setid(struct user_namespace *ns, int cap) { return true; } #endif /* CONFIG_MULTIUSER */ extern bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct inode *inode); extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap); extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns); static inline bool perfmon_capable(void) { return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN); } static inline bool bpf_capable(void) { return capable(CAP_BPF) || capable(CAP_SYS_ADMIN); } static inline bool checkpoint_restore_ns_capable(struct user_namespace *ns) { return ns_capable(ns, CAP_CHECKPOINT_RESTORE) || ns_capable(ns, CAP_SYS_ADMIN); } /* audit system wants to get cap info from files as well */ extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); extern int cap_convert_nscap(struct dentry *dentry, const void **ivalue, size_t size); #endif /* !_LINUX_CAPABILITY_H */