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         struct rcu_head         a_rcu;
  32         unsigned int            a_count;
  33         struct posix_acl_entry  a_entries[];
  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(int, gfp_t);
  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 extern int set_posix_acl(struct user_namespace *, struct inode *, int,
  73                          struct posix_acl *);
  74
  75 #ifdef CONFIG_FS_POSIX_ACL
  76 int posix_acl_chmod(struct user_namespace *, struct inode *, umode_t);
  77 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
  78                 struct posix_acl **);
  79 int posix_acl_update_mode(struct user_namespace *, struct inode *, umode_t *,
  80                           struct posix_acl **);
  81
  82 extern int simple_set_acl(struct user_namespace *, struct inode *,
  83                           struct posix_acl *, int);
  84 extern int simple_acl_create(struct inode *, struct inode *);
  85
  86 struct posix_acl *get_cached_acl(struct inode *inode, int type);
  87 struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
  88 void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
  89 void forget_cached_acl(struct inode *inode, int type);
  90 void forget_all_cached_acls(struct inode *inode);
  91 int posix_acl_valid(struct user_namespace *, const struct posix_acl *);
  92 int posix_acl_permission(struct user_namespace *, struct inode *,
  93                          const struct posix_acl *, int);
  94
  95 static inline void cache_no_acl(struct inode *inode)
  96 {
  97         inode->i_acl = NULL;
  98         inode->i_default_acl = NULL;
  99 }
 100 #else
 101 static inline int posix_acl_chmod(struct user_namespace *mnt_userns,
 102                                   struct inode *inode, umode_t mode)
 103 {
 104         return 0;
 105 }
 106
 107 #define simple_set_acl          NULL
 108
 109 static inline int simple_acl_create(struct inode *dir, struct inode *inode)
 110 {
 111         return 0;
 112 }
 113 static inline void cache_no_acl(struct inode *inode)
 114 {
 115 }
 116
 117 static inline int posix_acl_create(struct inode *inode, umode_t *mode,
 118                 struct posix_acl **default_acl, struct posix_acl **acl)
 119 {
 120         *default_acl = *acl = NULL;
 121         return 0;
 122 }
 123
 124 static inline void forget_all_cached_acls(struct inode *inode)
 125 {
 126 }
 127 #endif /* CONFIG_FS_POSIX_ACL */
 128
 129 struct posix_acl *get_acl(struct inode *inode, int type);
 130
 131 #endif  /* __LINUX_POSIX_ACL_H */