include/linux/xattr.h

   1 /*
   2   File: linux/xattr.h
   3
   4   Extended attributes handling.
   5
   6   Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
   7   Copyright (c) 2001-2002 Silicon Graphics, Inc.  All Rights Reserved.
   8   Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
   9 */
  10 #ifndef _LINUX_XATTR_H
  11 #define _LINUX_XATTR_H
  12
  13 #define XATTR_CREATE    0x1     /* set value, fail if attr already exists */
  14 #define XATTR_REPLACE   0x2     /* set value, fail if attr does not exist */
  15
  16 /* Namespaces */
  17 #define XATTR_OS2_PREFIX "os2."
  18 #define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)
  19
  20 #define XATTR_SECURITY_PREFIX   "security."
  21 #define XATTR_SECURITY_PREFIX_LEN (sizeof (XATTR_SECURITY_PREFIX) - 1)
  22
  23 #define XATTR_SYSTEM_PREFIX "system."
  24 #define XATTR_SYSTEM_PREFIX_LEN (sizeof (XATTR_SYSTEM_PREFIX) - 1)
  25
  26 #define XATTR_TRUSTED_PREFIX "trusted."
  27 #define XATTR_TRUSTED_PREFIX_LEN (sizeof (XATTR_TRUSTED_PREFIX) - 1)
  28
  29 #define XATTR_USER_PREFIX "user."
  30 #define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)
  31
  32 /* Security namespace */
  33 #define XATTR_EVM_SUFFIX "evm"
  34 #define XATTR_NAME_EVM XATTR_SECURITY_PREFIX XATTR_EVM_SUFFIX
  35
  36 #define XATTR_IMA_SUFFIX "ima"
  37 #define XATTR_NAME_IMA XATTR_SECURITY_PREFIX XATTR_IMA_SUFFIX
  38
  39 #define XATTR_SELINUX_SUFFIX "selinux"
  40 #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
  41
  42 #define XATTR_SMACK_SUFFIX "SMACK64"
  43 #define XATTR_SMACK_IPIN "SMACK64IPIN"
  44 #define XATTR_SMACK_IPOUT "SMACK64IPOUT"
  45 #define XATTR_SMACK_EXEC "SMACK64EXEC"
  46 #define XATTR_SMACK_TRANSMUTE "SMACK64TRANSMUTE"
  47 #define XATTR_SMACK_MMAP "SMACK64MMAP"
  48 #define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX
  49 #define XATTR_NAME_SMACKIPIN    XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN
  50 #define XATTR_NAME_SMACKIPOUT   XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT
  51 #define XATTR_NAME_SMACKEXEC    XATTR_SECURITY_PREFIX XATTR_SMACK_EXEC
  52 #define XATTR_NAME_SMACKTRANSMUTE XATTR_SECURITY_PREFIX XATTR_SMACK_TRANSMUTE
  53 #define XATTR_NAME_SMACKMMAP XATTR_SECURITY_PREFIX XATTR_SMACK_MMAP
  54
  55 #define XATTR_CAPS_SUFFIX "capability"
  56 #define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX
  57
  58 #define XATTR_POSIX_ACL_ACCESS  "posix_acl_access"
  59 #define XATTR_NAME_POSIX_ACL_ACCESS XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_ACCESS
  60 #define XATTR_POSIX_ACL_DEFAULT  "posix_acl_default"
  61 #define XATTR_NAME_POSIX_ACL_DEFAULT XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_DEFAULT
  62
  63 #ifdef  __KERNEL__
  64
  65 #include <linux/slab.h>
  66 #include <linux/types.h>
  67 #include <linux/spinlock.h>
  68
  69 struct inode;
  70 struct dentry;
  71
  72 struct xattr_handler {
  73         const char *prefix;
  74         int flags;      /* fs private flags passed back to the handlers */
  75         size_t (*list)(struct dentry *dentry, char *list, size_t list_size,
  76                        const char *name, size_t name_len, int handler_flags);
  77         int (*get)(struct dentry *dentry, const char *name, void *buffer,
  78                    size_t size, int handler_flags);
  79         int (*set)(struct dentry *dentry, const char *name, const void *buffer,
  80                    size_t size, int flags, int handler_flags);
  81 };
  82
  83 struct xattr {
  84         char *name;
  85         void *value;
  86         size_t value_len;
  87 };
  88
  89 ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
  90 ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
  91 ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
  92 int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
  93 int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
  94 int vfs_removexattr(struct dentry *, const char *);
  95
  96 ssize_t generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size);
  97 ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
  98 int generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags);
  99 int generic_removexattr(struct dentry *dentry, const char *name);
 100 ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
 101                            char **xattr_value, size_t size, gfp_t flags);
 102 int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
 103                   const char *value, size_t size, gfp_t flags);
 104
 105 struct simple_xattrs {
 106         struct list_head head;
 107         spinlock_t lock;
 108 };
 109
 110 struct simple_xattr {
 111         struct list_head list;
 112         char *name;
 113         size_t size;
 114         char value[0];
 115 };
 116
 117 /*
 118  * initialize the simple_xattrs structure
 119  */
 120 static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
 121 {
 122         INIT_LIST_HEAD(&xattrs->head);
 123         spin_lock_init(&xattrs->lock);
 124 }
 125
 126 /*
 127  * free all the xattrs
 128  */
 129 static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
 130 {
 131         struct simple_xattr *xattr, *node;
 132
 133         list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
 134                 kfree(xattr->name);
 135                 kfree(xattr);
 136         }
 137 }
 138
 139 struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
 140 int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
 141                      void *buffer, size_t size);
 142 int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
 143                      const void *value, size_t size, int flags);
 144 int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name);
 145 ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
 146                           size_t size);
 147 void simple_xattr_list_add(struct simple_xattrs *xattrs,
 148                            struct simple_xattr *new_xattr);
 149
 150 #endif  /*  __KERNEL__  */
 151
 152 #endif  /* _LINUX_XATTR_H */