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 <linux/ext4_jbd2.h> 13 #include <linux/ext4_fs.h> 14 #include "xattr.h" 15 16 #define XATTR_TRUSTED_PREFIX "trusted." 17 18 static size_t 19 ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size, 20 const char *name, size_t name_len) 21 { 22 const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1; 23 const size_t total_len = prefix_len + name_len + 1; 24 25 if (!capable(CAP_SYS_ADMIN)) 26 return 0; 27 28 if (list && total_len <= list_size) { 29 memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len); 30 memcpy(list+prefix_len, name, name_len); 31 list[prefix_len + name_len] = '\0'; 32 } 33 return total_len; 34 } 35 36 static int 37 ext4_xattr_trusted_get(struct inode *inode, const char *name, 38 void *buffer, size_t size) 39 { 40 if (strcmp(name, "") == 0) 41 return -EINVAL; 42 return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name, 43 buffer, size); 44 } 45 46 static int 47 ext4_xattr_trusted_set(struct inode *inode, 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(inode, EXT4_XATTR_INDEX_TRUSTED, name, 53 value, size, flags); 54 } 55 56 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