1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 File: linux/xattr.h 4 5 Extended attributes handling. 6 7 Copyright (C) 2001 by Andreas Gruenbacher <[email protected]> 8 Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved. 9 Copyright (c) 2004 Red Hat, Inc., James Morris <[email protected]> 10 */ 11 #ifndef _LINUX_XATTR_H 12 #define _LINUX_XATTR_H 13 14 15 #include <linux/slab.h> 16 #include <linux/types.h> 17 #include <linux/spinlock.h> 18 #include <linux/mm.h> 19 #include <uapi/linux/xattr.h> 20 21 struct inode; 22 struct dentry; 23 24 /* 25 * struct xattr_handler: When @name is set, match attributes with exactly that 26 * name. When @prefix is set instead, match attributes with that prefix and 27 * with a non-empty suffix. 28 */ 29 struct xattr_handler { 30 const char *name; 31 const char *prefix; 32 int flags; /* fs private flags */ 33 bool (*list)(struct dentry *dentry); 34 int (*get)(const struct xattr_handler *, struct dentry *dentry, 35 struct inode *inode, const char *name, void *buffer, 36 size_t size); 37 int (*set)(const struct xattr_handler *, 38 struct user_namespace *mnt_userns, struct dentry *dentry, 39 struct inode *inode, const char *name, const void *buffer, 40 size_t size, int flags); 41 }; 42 43 const char *xattr_full_name(const struct xattr_handler *, const char *); 44 45 struct xattr { 46 const char *name; 47 void *value; 48 size_t value_len; 49 }; 50 51 ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t); 52 ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t); 53 ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); 54 int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int); 55 int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int); 56 int __vfs_setxattr_locked(struct dentry *, const char *, const void *, size_t, int, struct inode **); 57 int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int); 58 int __vfs_removexattr(struct dentry *, const char *); 59 int __vfs_removexattr_locked(struct dentry *, const char *, struct inode **); 60 int vfs_removexattr(struct dentry *, const char *); 61 62 ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size); 63 ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name, 64 char **xattr_value, size_t size, gfp_t flags); 65 66 int xattr_supported_namespace(struct inode *inode, const char *prefix); 67 68 static inline const char *xattr_prefix(const struct xattr_handler *handler) 69 { 70 return handler->prefix ?: handler->name; 71 } 72 73 struct simple_xattrs { 74 struct list_head head; 75 spinlock_t lock; 76 }; 77 78 struct simple_xattr { 79 struct list_head list; 80 char *name; 81 size_t size; 82 char value[]; 83 }; 84 85 /* 86 * initialize the simple_xattrs structure 87 */ 88 static inline void simple_xattrs_init(struct simple_xattrs *xattrs) 89 { 90 INIT_LIST_HEAD(&xattrs->head); 91 spin_lock_init(&xattrs->lock); 92 } 93 94 /* 95 * free all the xattrs 96 */ 97 static inline void simple_xattrs_free(struct simple_xattrs *xattrs) 98 { 99 struct simple_xattr *xattr, *node; 100 101 list_for_each_entry_safe(xattr, node, &xattrs->head, list) { 102 kfree(xattr->name); 103 kvfree(xattr); 104 } 105 } 106 107 struct simple_xattr *simple_xattr_alloc(const void *value, size_t size); 108 int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, 109 void *buffer, size_t size); 110 int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, 111 const void *value, size_t size, int flags, 112 ssize_t *removed_size); 113 ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer, 114 size_t size); 115 void simple_xattr_list_add(struct simple_xattrs *xattrs, 116 struct simple_xattr *new_xattr); 117 118 #endif /* _LINUX_XATTR_H */ 119