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 <linux/mm.h> 19 #include <linux/user_namespace.h> 20 #include <uapi/linux/xattr.h> 21 22 struct inode; 23 struct dentry; 24 25 static inline bool is_posix_acl_xattr(const char *name) 26 { 27 return (strcmp(name, XATTR_NAME_POSIX_ACL_ACCESS) == 0) || 28 (strcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0); 29 } 30 31 /* 32 * struct xattr_handler: When @name is set, match attributes with exactly that 33 * name. When @prefix is set instead, match attributes with that prefix and 34 * with a non-empty suffix. 35 */ 36 struct xattr_handler { 37 const char *name; 38 const char *prefix; 39 int flags; /* fs private flags */ 40 bool (*list)(struct dentry *dentry); 41 int (*get)(const struct xattr_handler *, struct dentry *dentry, 42 struct inode *inode, const char *name, void *buffer, 43 size_t size); 44 int (*set)(const struct xattr_handler *, 45 struct mnt_idmap *idmap, struct dentry *dentry, 46 struct inode *inode, const char *name, const void *buffer, 47 size_t size, int flags); 48 }; 49 50 const char *xattr_full_name(const struct xattr_handler *, const char *); 51 52 struct xattr { 53 const char *name; 54 void *value; 55 size_t value_len; 56 }; 57 58 ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t); 59 ssize_t vfs_getxattr(struct mnt_idmap *, struct dentry *, const char *, 60 void *, size_t); 61 ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size); 62 int __vfs_setxattr(struct mnt_idmap *, struct dentry *, struct inode *, 63 const char *, const void *, size_t, int); 64 int __vfs_setxattr_noperm(struct mnt_idmap *, struct dentry *, 65 const char *, const void *, size_t, int); 66 int __vfs_setxattr_locked(struct mnt_idmap *, struct dentry *, 67 const char *, const void *, size_t, int, 68 struct inode **); 69 int vfs_setxattr(struct mnt_idmap *, struct dentry *, const char *, 70 const void *, size_t, int); 71 int __vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *); 72 int __vfs_removexattr_locked(struct mnt_idmap *, struct dentry *, 73 const char *, struct inode **); 74 int vfs_removexattr(struct mnt_idmap *, struct dentry *, const char *); 75 76 ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size); 77 int vfs_getxattr_alloc(struct mnt_idmap *idmap, 78 struct dentry *dentry, const char *name, 79 char **xattr_value, size_t size, gfp_t flags); 80 81 int xattr_supported_namespace(struct inode *inode, const char *prefix); 82 83 static inline const char *xattr_prefix(const struct xattr_handler *handler) 84 { 85 return handler->prefix ?: handler->name; 86 } 87 88 struct simple_xattrs { 89 struct rb_root rb_root; 90 rwlock_t lock; 91 }; 92 93 struct simple_xattr { 94 struct rb_node rb_node; 95 char *name; 96 size_t size; 97 char value[]; 98 }; 99 100 void simple_xattrs_init(struct simple_xattrs *xattrs); 101 void simple_xattrs_free(struct simple_xattrs *xattrs); 102 struct simple_xattr *simple_xattr_alloc(const void *value, size_t size); 103 int simple_xattr_get(struct simple_xattrs *xattrs, const char *name, 104 void *buffer, size_t size); 105 int simple_xattr_set(struct simple_xattrs *xattrs, const char *name, 106 const void *value, size_t size, int flags, 107 ssize_t *removed_size); 108 ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, 109 char *buffer, size_t size); 110 void simple_xattr_add(struct simple_xattrs *xattrs, 111 struct simple_xattr *new_xattr); 112 113 #endif /* _LINUX_XATTR_H */ 114