LXR linux/include/linux/posix

   1/*
   2  File: linux/posix_acl.h
   3
   4  (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
   5*/
   6
   7
   8#ifndef __LINUX_POSIX_ACL_H
   9#define __LINUX_POSIX_ACL_H
  10
  11#include <linux/bug.h>
  12#include <linux/slab.h>
  13#include <linux/rcupdate.h>
  14
  15#define ACL_UNDEFINED_ID        (-1)
  16
  17/* a_type field in acl_user_posix_entry_t */
  18#define ACL_TYPE_ACCESS         (0x8000)
  19#define ACL_TYPE_DEFAULT        (0x4000)
  20
  21/* e_tag entry in struct posix_acl_entry */
  22#define ACL_USER_OBJ            (0x01)
  23#define ACL_USER                (0x02)
  24#define ACL_GROUP_OBJ           (0x04)
  25#define ACL_GROUP               (0x08)
  26#define ACL_MASK                (0x10)
  27#define ACL_OTHER               (0x20)
  28
  29/* permissions in the e_perm field */
  30#define ACL_READ                (0x04)
  31#define ACL_WRITE               (0x02)
  32#define ACL_EXECUTE             (0x01)
  33//#define ACL_ADD               (0x08)
  34//#define ACL_DELETE            (0x10)
  35
  36struct posix_acl_entry {
  37        short                   e_tag;
  38        unsigned short          e_perm;
  39        union {
  40                kuid_t          e_uid;
  41                kgid_t          e_gid;
  42        };
  43};
  44
  45struct posix_acl {
  46        union {
  47                atomic_t                a_refcount;
  48                struct rcu_head         a_rcu;
  49        };
  50        unsigned int            a_count;
  51        struct posix_acl_entry  a_entries[0];
  52};
  53
  54#define FOREACH_ACL_ENTRY(pa, acl, pe) \
  55        for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
  56
  57
  58/*
  59 * Duplicate an ACL handle.
  60 */
  61static inline struct posix_acl *
  62posix_acl_dup(struct posix_acl *acl)
  63{
  64        if (acl)
  65                atomic_inc(&acl->a_refcount);
  66        return acl;
  67}
  68
  69/*
  70 * Free an ACL handle.
  71 */
  72static inline void
  73posix_acl_release(struct posix_acl *acl)
  74{
  75        if (acl && atomic_dec_and_test(&acl->a_refcount))
  76                kfree_rcu(acl, a_rcu);
  77}
  78
  79
  80/* posix_acl.c */
  81
  82extern void posix_acl_init(struct posix_acl *, int);
  83extern struct posix_acl *posix_acl_alloc(int, gfp_t);
  84extern int posix_acl_valid(const struct posix_acl *);
  85extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
  86extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
  87extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
  88extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
  89extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
  90
  91extern struct posix_acl *get_posix_acl(struct inode *, int);
  92extern int set_posix_acl(struct inode *, int, struct posix_acl *);
  93
  94#ifdef CONFIG_FS_POSIX_ACL
  95extern int posix_acl_chmod(struct inode *, umode_t);
  96extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
  97                struct posix_acl **);
  98
  99extern int simple_set_acl(struct inode *, struct posix_acl *, int);
 100extern int simple_acl_create(struct inode *, struct inode *);
 101
 102struct posix_acl **acl_by_type(struct inode *inode, int type);
 103struct posix_acl *get_cached_acl(struct inode *inode, int type);
 104struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type);
 105void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl);
 106void forget_cached_acl(struct inode *inode, int type);
 107void forget_all_cached_acls(struct inode *inode);
 108
 109static inline void cache_no_acl(struct inode *inode)
 110{
 111        inode->i_acl = NULL;
 112        inode->i_default_acl = NULL;
 113}
 114#else
 115static inline int posix_acl_chmod(struct inode *inode, umode_t mode)
 116{
 117        return 0;
 118}
 119
 120#define simple_set_acl          NULL
 121
 122static inline int simple_acl_create(struct inode *dir, struct inode *inode)
 123{
 124        return 0;
 125}
 126static inline void cache_no_acl(struct inode *inode)
 127{
 128}
 129
 130static inline int posix_acl_create(struct inode *inode, umode_t *mode,
 131                struct posix_acl **default_acl, struct posix_acl **acl)
 132{
 133        *default_acl = *acl = NULL;
 134        return 0;
 135}
 136
 137static inline void forget_all_cached_acls(struct inode *inode)
 138{
 139}
 140#endif /* CONFIG_FS_POSIX_ACL */
 141
 142struct posix_acl *get_acl(struct inode *inode, int type);
 143
 144#endif  /* __LINUX_POSIX_ACL_H */
 145