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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * This is <linux/capability.h>4 *5 * Andrew G. Morgan <morgan@kernel.org>6 * Alexander Kjeldaas <astor@guardian.no>7 * with help from Aleph1, Roland Buresund and Andrew Main.8 *9 * See here for the libcap library ("POSIX draft" compliance):10 *11 * ftp://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/12 */13#ifndef _LINUX_CAPABILITY_H14#define _LINUX_CAPABILITY_H15 16#include <uapi/linux/capability.h>17#include <linux/uidgid.h>18#include <linux/bits.h>19 20#define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_321 22extern int file_caps_enabled;23 24typedef struct { u64 val; } kernel_cap_t;25 26/* same as vfs_ns_cap_data but in cpu endian and always filled completely */27struct cpu_vfs_cap_data {28 __u32 magic_etc;29 kuid_t rootid;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 37struct file;38struct inode;39struct dentry;40struct task_struct;41struct user_namespace;42struct mnt_idmap;43 44/*45 * CAP_FS_MASK and CAP_NFSD_MASKS:46 *47 * The fs mask is all the privileges that fsuid==0 historically meant.48 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.49 *50 * It has never meant setting security.* and trusted.* xattrs.51 *52 * We could also define fsmask as follows:53 * 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions54 * 2. The security.* and trusted.* xattrs are fs-related MAC permissions55 */56 57# define CAP_FS_MASK (BIT_ULL(CAP_CHOWN) \58 | BIT_ULL(CAP_MKNOD) \59 | BIT_ULL(CAP_DAC_OVERRIDE) \60 | BIT_ULL(CAP_DAC_READ_SEARCH) \61 | BIT_ULL(CAP_FOWNER) \62 | BIT_ULL(CAP_FSETID) \63 | BIT_ULL(CAP_MAC_OVERRIDE))64#define CAP_VALID_MASK (BIT_ULL(CAP_LAST_CAP+1)-1)65 66# define CAP_EMPTY_SET ((kernel_cap_t) { 0 })67# define CAP_FULL_SET ((kernel_cap_t) { CAP_VALID_MASK })68# define CAP_FS_SET ((kernel_cap_t) { CAP_FS_MASK | BIT_ULL(CAP_LINUX_IMMUTABLE) })69# define CAP_NFSD_SET ((kernel_cap_t) { CAP_FS_MASK | BIT_ULL(CAP_SYS_RESOURCE) })70 71# define cap_clear(c) do { (c).val = 0; } while (0)72 73#define cap_raise(c, flag) ((c).val |= BIT_ULL(flag))74#define cap_lower(c, flag) ((c).val &= ~BIT_ULL(flag))75#define cap_raised(c, flag) (((c).val & BIT_ULL(flag)) != 0)76 77static inline kernel_cap_t cap_combine(const kernel_cap_t a,78 const kernel_cap_t b)79{80 return (kernel_cap_t) { a.val | b.val };81}82 83static inline kernel_cap_t cap_intersect(const kernel_cap_t a,84 const kernel_cap_t b)85{86 return (kernel_cap_t) { a.val & b.val };87}88 89static inline kernel_cap_t cap_drop(const kernel_cap_t a,90 const kernel_cap_t drop)91{92 return (kernel_cap_t) { a.val &~ drop.val };93}94 95static inline bool cap_isclear(const kernel_cap_t a)96{97 return !a.val;98}99 100static inline bool cap_isidentical(const kernel_cap_t a, const kernel_cap_t b)101{102 return a.val == b.val;103}104 105/*106 * Check if "a" is a subset of "set".107 * return true if ALL of the capabilities in "a" are also in "set"108 * cap_issubset(0101, 1111) will return true109 * return false if ANY of the capabilities in "a" are not in "set"110 * cap_issubset(1111, 0101) will return false111 */112static inline bool cap_issubset(const kernel_cap_t a, const kernel_cap_t set)113{114 return !(a.val & ~set.val);115}116 117/* Used to decide between falling back on the old suser() or fsuser(). */118 119static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)120{121 return cap_drop(a, CAP_FS_SET);122}123 124static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,125 const kernel_cap_t permitted)126{127 return cap_combine(a, cap_intersect(permitted, CAP_FS_SET));128}129 130static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)131{132 return cap_drop(a, CAP_NFSD_SET);133}134 135static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,136 const kernel_cap_t permitted)137{138 return cap_combine(a, cap_intersect(permitted, CAP_NFSD_SET));139}140 141#ifdef CONFIG_MULTIUSER142extern bool has_capability(struct task_struct *t, int cap);143extern bool has_ns_capability(struct task_struct *t,144 struct user_namespace *ns, int cap);145extern bool has_capability_noaudit(struct task_struct *t, int cap);146extern bool has_ns_capability_noaudit(struct task_struct *t,147 struct user_namespace *ns, int cap);148extern bool capable(int cap);149extern bool ns_capable(struct user_namespace *ns, int cap);150extern bool ns_capable_noaudit(struct user_namespace *ns, int cap);151extern bool ns_capable_setid(struct user_namespace *ns, int cap);152#else153static inline bool has_capability(struct task_struct *t, int cap)154{155 return true;156}157static inline bool has_ns_capability(struct task_struct *t,158 struct user_namespace *ns, int cap)159{160 return true;161}162static inline bool has_capability_noaudit(struct task_struct *t, int cap)163{164 return true;165}166static inline bool has_ns_capability_noaudit(struct task_struct *t,167 struct user_namespace *ns, int cap)168{169 return true;170}171static inline bool capable(int cap)172{173 return true;174}175static inline bool ns_capable(struct user_namespace *ns, int cap)176{177 return true;178}179static inline bool ns_capable_noaudit(struct user_namespace *ns, int cap)180{181 return true;182}183static inline bool ns_capable_setid(struct user_namespace *ns, int cap)184{185 return true;186}187#endif /* CONFIG_MULTIUSER */188bool privileged_wrt_inode_uidgid(struct user_namespace *ns,189 struct mnt_idmap *idmap,190 const struct inode *inode);191bool capable_wrt_inode_uidgid(struct mnt_idmap *idmap,192 const struct inode *inode, int cap);193extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap);194extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns);195static inline bool perfmon_capable(void)196{197 return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN);198}199 200static inline bool bpf_capable(void)201{202 return capable(CAP_BPF) || capable(CAP_SYS_ADMIN);203}204 205static inline bool checkpoint_restore_ns_capable(struct user_namespace *ns)206{207 return ns_capable(ns, CAP_CHECKPOINT_RESTORE) ||208 ns_capable(ns, CAP_SYS_ADMIN);209}210 211/* audit system wants to get cap info from files as well */212int get_vfs_caps_from_disk(struct mnt_idmap *idmap,213 const struct dentry *dentry,214 struct cpu_vfs_cap_data *cpu_caps);215 216int cap_convert_nscap(struct mnt_idmap *idmap, struct dentry *dentry,217 const void **ivalue, size_t size);218 219#endif /* !_LINUX_CAPABILITY_H */220