1 /* 2 * linux/fs/ext4/xattr_trusted.c 3 * Handler for trusted extended attributes. 4 * 5 * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org> 6 */ 7 8 #include <linux/string.h> 9 #include <linux/capability.h> 10 #include <linux/fs.h> 11 #include "ext4_jbd2.h" 12 #include "ext4.h" 13 #include "xattr.h" 14 15 static size_t 16 ext4_xattr_trusted_list(const struct xattr_handler *handler, 17 struct dentry *dentry, char *list, size_t list_size, 18 const char *name, size_t name_len) 19 { 20 const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN; 21 const size_t total_len = prefix_len + name_len + 1; 22 23 if (!capable(CAP_SYS_ADMIN)) 24 return 0; 25 26 if (list && total_len <= list_size) { 27 memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len); 28 memcpy(list+prefix_len, name, name_len); 29 list[prefix_len + name_len] = '\0'; 30 } 31 return total_len; 32 } 33 34 static int 35 ext4_xattr_trusted_get(const struct xattr_handler *handler, 36 struct dentry *dentry, const char *name, void *buffer, 37 size_t size) 38 { 39 if (strcmp(name, "") == 0) 40 return -EINVAL; 41 return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED, 42 name, buffer, size); 43 } 44 45 static int 46 ext4_xattr_trusted_set(const struct xattr_handler *handler, 47 struct dentry *dentry, const char *name, 48 const void *value, size_t size, int flags) 49 { 50 if (strcmp(name, "") == 0) 51 return -EINVAL; 52 return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED, 53 name, value, size, flags); 54 } 55 56 const struct xattr_handler ext4_xattr_trusted_handler = { 57 .prefix = XATTR_TRUSTED_PREFIX, 58 .list = ext4_xattr_trusted_list, 59 .get = ext4_xattr_trusted_get, 60 .set = ext4_xattr_trusted_set, 61 }; 62