| 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 inode *inode, 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(struct inode *inode, const char *name, |
| 36 | void *buffer, size_t size) |
| 37 | { |
| 38 | if (strcmp(name, "") == 0) |
| 39 | return -EINVAL; |
| 40 | return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name, |
| 41 | buffer, size); |
| 42 | } |
| 43 | |
| 44 | static int |
| 45 | ext4_xattr_trusted_set(struct inode *inode, const char *name, |
| 46 | const void *value, size_t size, int flags) |
| 47 | { |
| 48 | if (strcmp(name, "") == 0) |
| 49 | return -EINVAL; |
| 50 | return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name, |
| 51 | value, size, flags); |
| 52 | } |
| 53 | |
| 54 | 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 | }; |