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/smp_lock.h> 13 #include <linux/ext4_jbd2.h> 14 #include <linux/ext4_fs.h> 15 #include "xattr.h" 16 17 #define XATTR_TRUSTED_PREFIX "trusted." 18 19 static size_t 20 ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size, 21 const char *name, size_t name_len) 22 { 23 const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1; 24 const size_t total_len = prefix_len + name_len + 1; 25 26 if (!capable(CAP_SYS_ADMIN)) 27 return 0; 28 29 if (list && total_len <= list_size) { 30 memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len); 31 memcpy(list+prefix_len, name, name_len); 32 list[prefix_len + name_len] = '\0'; 33 } 34 return total_len; 35 } 36 37 static int 38 ext4_xattr_trusted_get(struct inode *inode, const char *name, 39 void *buffer, size_t size) 40 { 41 if (strcmp(name, "") == 0) 42 return -EINVAL; 43 return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name, 44 buffer, size); 45 } 46 47 static int 48 ext4_xattr_trusted_set(struct inode *inode, const char *name, 49 const void *value, size_t size, int flags) 50 { 51 if (strcmp(name, "") == 0) 52 return -EINVAL; 53 return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name, 54 value, size, flags); 55 } 56 57 struct xattr_handler ext4_xattr_trusted_handler = { 58 .prefix = XATTR_TRUSTED_PREFIX, 59 .list = ext4_xattr_trusted_list, 60 .get = ext4_xattr_trusted_get, 61 .set = ext4_xattr_trusted_set, 62 }; 63