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 <a.gruenbacher@computer.org> 8 Copyright (c) 2001-2002 Silicon Graphics, Inc. All Rights Reserved. 9 Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> 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 <uapi/linux/xattr.h> 19 20 struct inode; 21 struct dentry; 22 23 /* 24 * struct xattr_handler: When @name is set, match attributes with exactly that 25 * name. When @prefix is set instead, match attributes with that prefix and 26 * with a non-empty suffix. 27 */ 28 struct xattr_handler { 29 const char *name; 30 const char *prefix; 31 int flags; /* fs private flags */ 32 bool (*list)(struct dentry *dentry); 33 int (*get)(const struct xattr_handler *, struct dentry *dentry, 34 struct inode *inode, const char *name, void *buffer, 35 size_t size); 36 int (*set)(const struct xattr_handler *, struct dentry *dentry, 37 struct inode *inode, const char *name, const void *buffer, 38 size_t size, int flags); 39 }; 40 41 const char *xattr_full_name(const struct xattr_handler *, const char *); 42 43 struct xattr { 44 const char *name; 45 void *value; 46 size_t value_len; 47 }; 48 49 ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t); 50 ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t); 51 ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); 52 int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int); 53 int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int); 54 int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int); 55 int __vfs_removexattr(struct dentry *, const char *); 56 int vfs_removexattr(struct dentry *, const char *); 57 58 ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size); 59 ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name, 60 char **xattr_value, size_t size, gfp_t flags); 61 62 static inline const char *xattr_prefix(const struct xattr_handler *handler) 63 { 64 return handler->prefix ?: handler->name; 65 } 66 67 struct simple_xattrs { 68 struct list_head head; 69 spinlock_t lock; 70 }; 71 72 struct simple_xattr { 73 struct list_head list; 74 char *name; 75 size_t size; 76 char value[0]; 77 }; 78 79 /* 80 * initialize the simple_xattrs structure 81 */ 82 static inline void simple_xattrs_init(struct simple_xattrs *xattrs) 83 { 84 INIT_LIST_HEAD(&xattrs->head); 85 spin_lock_init(&xattrs->lock); 86 } 87 88 /* 89 * free all the xattrs 90 */ 91 static inline void simple_xattrs_free(struct simple_xattrs *xattrs) 92 { 93 struct simple_xattr *xattr, *node; 94 95 list_for_each_entry_safe(xattr, node, &xattrs->head, list) { 96 kfree(xattr->name); 97 kfree(xattr); 98 } 99 } 100 101 struct simple_xattr *simple_xattr_alloc(const void *value, size_t size); 102 int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, 103 void *buffer, size_t size); 104 int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, 105 const void *value, size_t size, int flags); 106 ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer, 107 size_t size); 108 void simple_xattr_list_add(struct simple_xattrs *xattrs, 109 struct simple_xattr *new_xattr); 110 111 #endif /* _LINUX_XATTR_H */ 112