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/module.h> 9 #include <linux/string.h> 10 #include <linux/capability.h> 11 #include <linux/fs.h> 12 #include "ext4_jbd2.h" 13 #include "ext4.h" 14 #include "xattr.h" 15 16 static size_t 17 ext4_xattr_trusted_list(struct dentry *dentry, char *list, size_t list_size, 18 const char *name, size_t name_len, int type) 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(struct dentry *dentry, const char *name, void *buffer, 36 size_t size, int type) 37 { 38 if (strcmp(name, "") == 0) 39 return -EINVAL; 40 return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED, 41 name, buffer, size); 42 } 43 44 static int 45 ext4_xattr_trusted_set(struct dentry *dentry, const char *name, 46 const void *value, size_t size, int flags, int type) 47 { 48 if (strcmp(name, "") == 0) 49 return -EINVAL; 50 return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED, 51 name, value, size, flags); 52 } 53 54 const struct xattr_handler ext4_xattr_trusted_handler = { 55 .prefix = XATTR_TRUSTED_PREFIX, 56 .list = ext4_xattr_trusted_list, 57 .get = ext4_xattr_trusted_get, 58 .set = ext4_xattr_trusted_set, 59 }; 60