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(struct dentry *dentry, char *list, size_t list_size, 17 const char *name, size_t name_len, int type) 18 { 19 const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN; 20 const size_t total_len = prefix_len + name_len + 1; 21 22 if (!capable(CAP_SYS_ADMIN)) 23 return 0; 24 25 if (list && total_len <= list_size) { 26 memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len); 27 memcpy(list+prefix_len, name, name_len); 28 list[prefix_len + name_len] = '\0'; 29 } 30 return total_len; 31 } 32 33 static int 34 ext4_xattr_trusted_get(struct dentry *dentry, const char *name, void *buffer, 35 size_t size, int type) 36 { 37 if (strcmp(name, "") == 0) 38 return -EINVAL; 39 return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED, 40 name, buffer, size); 41 } 42 43 static int 44 ext4_xattr_trusted_set(struct dentry *dentry, const char *name, 45 const void *value, size_t size, int flags, int type) 46 { 47 if (strcmp(name, "") == 0) 48 return -EINVAL; 49 return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED, 50 name, value, size, flags); 51 } 52 53 const struct xattr_handler ext4_xattr_trusted_handler = { 54 .prefix = XATTR_TRUSTED_PREFIX, 55 .list = ext4_xattr_trusted_list, 56 .get = ext4_xattr_trusted_get, 57 .set = ext4_xattr_trusted_set, 58 }; 59