include/linux/posix_acl.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3   File: linux/posix_acl.h
   4
   5   (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   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         refcount_t              a_refcount;
  31         unsigned int            a_count;
  32         struct rcu_head         a_rcu;
  33         struct posix_acl_entry  a_entries[] __counted_by(a_count);
  34 };
  35
  36 #define FOREACH_ACL_ENTRY(pa, acl, pe) \
  37         for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
  38
  39
  40 /*
  41  * Duplicate an ACL handle.
  42  */
  43 static inline struct posix_acl *
  44 posix_acl_dup(struct posix_acl *acl)
  45 {
  46         if (acl)
  47                 refcount_inc(&acl->a_refcount);
  48         return acl;
  49 }
  50
  51 /*
  52  * Free an ACL handle.
  53  */
  54 static inline void
  55 posix_acl_release(struct posix_acl *acl)
  56 {
  57         if (acl && refcount_dec_and_test(&acl->a_refcount))
  58                 kfree_rcu(acl, a_rcu);
  59 }
  60
  61
  62 /* posix_acl.c */
  63
  64 extern void posix_acl_init(struct posix_acl *, int);
  65 extern struct posix_acl *posix_acl_alloc(unsigned int count, gfp_t flags);
  66 extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
  67 extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
  68 extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
  69 extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
  70
  71 extern struct posix_acl *get_posix_acl(struct inode *, int);
  72 int set_posix_acl(struct mnt_idmap *, struct dentry *, int,
  73                   struct posix_acl *);
  74
  75 struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
  76 struct posix_acl *posix_acl_clone(const struct posix_acl *acl, gfp_t flags);
  77
  78 #ifdef CONFIG_FS_POSIX_ACL
  79 int posix_acl_chmod(struct mnt_idmap *, struct dentry *, umode_t);
  80 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
  81                 struct posix_acl **);
  82 int posix_acl_update_mode(struct mnt_idmap *, struct inode *, umode_t *,
  83                           struct posix_acl **);
  84
  85 int simple_set_acl(struct mnt_idmap *, struct dentry *,
  86                    struct posix_acl *, int);
  87 extern int simple_acl_create(struct inode *, struct inode *);
  88
  89 struct posix_acl *get_cached_acl(struct inode *inode, int type);
  90 void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
  91 void forget_cached_acl(struct inode *inode, int type);
  92 void forget_all_cached_acls(struct inode *inode);
  93 int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
  94 int posix_acl_permission(struct mnt_idmap *, struct inode *,
  95                          const struct posix_acl *, int);
  96
  97 static inline void cache_no_acl(struct inode *inode)
  98 {
  99         inode->i_acl = NULL;
 100         inode->i_default_acl = NULL;
 101 }
 102
 103 int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 104                 const char *acl_name, struct posix_acl *kacl);
 105 struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
 106                               struct dentry *dentry, const char *acl_name);
 107 int vfs_remove_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 108                    const char *acl_name);
 109 int posix_acl_listxattr(struct inode *inode, char **buffer,
 110                         ssize_t *remaining_size);
 111 #else
 112 static inline int posix_acl_chmod(struct mnt_idmap *idmap,
 113                                   struct dentry *dentry, umode_t mode)
 114 {
 115         return 0;
 116 }
 117
 118 #define simple_set_acl          NULL
 119
 120 static inline int simple_acl_create(struct inode *dir, struct inode *inode)
 121 {
 122         return 0;
 123 }
 124 static inline void cache_no_acl(struct inode *inode)
 125 {
 126 }
 127
 128 static inline int posix_acl_create(struct inode *inode, umode_t *mode,
 129                 struct posix_acl **default_acl, struct posix_acl **acl)
 130 {
 131         *default_acl = *acl = NULL;
 132         return 0;
 133 }
 134
 135 static inline void forget_all_cached_acls(struct inode *inode)
 136 {
 137 }
 138
 139 static inline int vfs_set_acl(struct mnt_idmap *idmap,
 140                               struct dentry *dentry, const char *name,
 141                               struct posix_acl *acl)
 142 {
 143         return -EOPNOTSUPP;
 144 }
 145
 146 static inline struct posix_acl *vfs_get_acl(struct mnt_idmap *idmap,
 147                                             struct dentry *dentry,
 148                                             const char *acl_name)
 149 {
 150         return ERR_PTR(-EOPNOTSUPP);
 151 }
 152
 153 static inline int vfs_remove_acl(struct mnt_idmap *idmap,
 154                                  struct dentry *dentry, const char *acl_name)
 155 {
 156         return -EOPNOTSUPP;
 157 }
 158 static inline int posix_acl_listxattr(struct inode *inode, char **buffer,
 159                                       ssize_t *remaining_size)
 160 {
 161         return 0;
 162 }
 163 #endif /* CONFIG_FS_POSIX_ACL */
 164
 165 struct posix_acl *get_inode_acl(struct inode *inode, int type);
 166
 167 #endif  /* __LINUX_POSIX_ACL_H */