1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 File: linux/posix_acl.h 4 5 (C) 2002 Andreas Gruenbacher, <[email protected]> 6 */ 7 8 9 #ifndef __LINUX_POSIX_ACL_H 10 #define __LINUX_POSIX_ACL_H 11 12 #include <linux/bug.h> 13 #include <linux/slab.h> 14 #include <linux/rcupdate.h> 15 #include <linux/refcount.h> 16 #include <uapi/linux/posix_acl.h> 17 18 struct user_namespace; 19 20 struct posix_acl_entry { 21 short e_tag; 22 unsigned short e_perm; 23 union { 24 kuid_t e_uid; 25 kgid_t e_gid; 26 }; 27 }; 28 29 struct posix_acl { 30 /* New members MUST be added within the struct_group() macro below. */ 31 struct_group_tagged(posix_acl_hdr, hdr, 32 refcount_t a_refcount; 33 unsigned int a_count; 34 struct rcu_head a_rcu; 35 ); 36 struct posix_acl_entry a_entries[] __counted_by(a_count); 37 }; 38 static_assert(offsetof(struct posix_acl, a_entries) == sizeof(struct posix_acl_hdr), 39 "struct member likely outside of struct_group_tagged()"); 40 41 #define FOREACH_ACL_ENTRY(pa, acl, pe) \ 42 for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++) 43 44 45 /* 46 * Duplicate an ACL handle. 47 */ 48 static inline struct posix_acl * 49 posix_acl_dup(struct posix_acl *acl) 50 { 51 if (acl) 52 refcount_inc(&acl->a_refcount); 53 return acl; 54 } 55 56 /* 57 * Free an ACL handle. 58 */ 59 static inline void 60 posix_acl_release(struct posix_acl *acl) 61 { 62 if (acl && refcount_dec_and_test(&acl->a_refcount)) 63 kfree_rcu(acl, a_rcu); 64 } 65 66 67 /* posix_acl.c */ 68 69 extern void posix_acl_init(struct posix_acl *, int); 70 extern struct posix_acl *posix_acl_alloc(unsigned int count, gfp_t flags); 71 extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t); 72 extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *); 73 extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *); 74 extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t); 75 76 extern struct posix_acl *get_posix_acl(struct inode *, int); 77 int set_posix_acl(struct mnt_idmap *, struct dentry *, int, 78 struct posix_acl *); 79 80 struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type); 81 struct posix_acl *posix_acl_clone(const struct posix_acl *acl, gfp_t flags); 82 83 #ifdef CONFIG_FS_POSIX_ACL 84 int posix_acl_chmod(struct mnt_idmap *, struct dentry *, umode_t); 85 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **, 86 struct posix_acl **); 87 int posix_acl_update_mode(struct mnt_idmap *, struct inode *, umode_t *, 88 struct posix_acl **); 89 90 int simple_set_acl(struct mnt_idmap *, struct dentry *, 91 struct posix_acl *, int); 92 extern int simple_acl_create(struct inode *, struct inode *); 93 94 struct posix_acl *get_cached_acl(struct inode *inode, int type); 95 void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl); 96 void forget_cached_acl(struct inode *inode, int type); 97 void forget_all_cached_acls(struct inode *inode); 98 int posix_acl_valid(struct user_namespace *, const struct posix_acl *); 99 int posix_acl_permission(struct mnt_idmap *, struct inode *, 100 const struct posix_acl *, int); 101 102 static inline void cache_no_acl(struct inode *inode) 103 { 104 inode->i_acl = NULL; 105 inode->i_default_acl = NULL; 106 } 107 108 int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, 109 const char *acl_name, struct posix_acl *kacl); 110 struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap, 111 struct dentry *dentry, const char *acl_name); 112 int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry, 113 const char *acl_name); 114 int posix_acl_listxattr(struct inode *inode, char **buffer, 115 ssize_t *remaining_size); 116 #else 117 static inline int posix_acl_chmod(struct mnt_idmap *idmap, 118 struct dentry *dentry, umode_t mode) 119 { 120 return 0; 121 } 122 123 #define simple_set_acl NULL 124 125 static inline int simple_acl_create(struct inode *dir, struct inode *inode) 126 { 127 return 0; 128 } 129 static inline void cache_no_acl(struct inode *inode) 130 { 131 } 132 133 static inline int posix_acl_create(struct inode *inode, umode_t *mode, 134 struct posix_acl **default_acl, struct posix_acl **acl) 135 { 136 *default_acl = *acl = NULL; 137 return 0; 138 } 139 140 static inline void forget_all_cached_acls(struct inode *inode) 141 { 142 } 143 144 static inline int vfs_set_acl(struct mnt_idmap *idmap, 145 struct dentry *dentry, const char *name, 146 struct posix_acl *acl) 147 { 148 return -EOPNOTSUPP; 149 } 150 151 static inline struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap, 152 struct dentry *dentry, 153 const char *acl_name) 154 { 155 return ERR_PTR(-EOPNOTSUPP); 156 } 157 158 static inline int vfs_remove_acl(struct mnt_idmap *idmap, 159 struct dentry *dentry, const char *acl_name) 160 { 161 return -EOPNOTSUPP; 162 } 163 static inline int posix_acl_listxattr(struct inode *inode, char **buffer, 164 ssize_t *remaining_size) 165 { 166 return 0; 167 } 168 #endif /* CONFIG_FS_POSIX_ACL */ 169 170 struct posix_acl *get_inode_acl(struct inode *inode, int type); 171 172 #endif /* __LINUX_POSIX_ACL_H */ 173