1 /* 2 * linux/fs/ext2/xattr_user.c 3 * Handler for extended user attributes. 4 * 5 * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org> 6 */ 7 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/string.h> 11 #include "ext2.h" 12 #include "xattr.h" 13 14 #define XATTR_USER_PREFIX "user." 15 16 static size_t 17 ext2_xattr_user_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 = sizeof(XATTR_USER_PREFIX)-1; 21 const size_t total_len = prefix_len + name_len + 1; 22 23 if (!test_opt(inode->i_sb, XATTR_USER)) 24 return 0; 25 26 if (list && total_len <= list_size) { 27 memcpy(list, XATTR_USER_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 ext2_xattr_user_get(struct inode *inode, const char *name, 36 void *buffer, size_t size) 37 { 38 int error; 39 40 if (strcmp(name, "") == 0) 41 return -EINVAL; 42 if (!test_opt(inode->i_sb, XATTR_USER)) 43 return -EOPNOTSUPP; 44 error = permission(inode, MAY_READ, NULL); 45 if (error) 46 return error; 47 48 return ext2_xattr_get(inode, EXT2_XATTR_INDEX_USER, name, buffer, size); 49 } 50 51 static int 52 ext2_xattr_user_set(struct inode *inode, const char *name, 53 const void *value, size_t size, int flags) 54 { 55 int error; 56 57 if (strcmp(name, "") == 0) 58 return -EINVAL; 59 if (!test_opt(inode->i_sb, XATTR_USER)) 60 return -EOPNOTSUPP; 61 if ( !S_ISREG(inode->i_mode) && 62 (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX)) 63 return -EPERM; 64 error = permission(inode, MAY_WRITE, NULL); 65 if (error) 66 return error; 67 68 return ext2_xattr_set(inode, EXT2_XATTR_INDEX_USER, name, 69 value, size, flags); 70 } 71 72 struct xattr_handler ext2_xattr_user_handler = { 73 .prefix = XATTR_USER_PREFIX, 74 .list = ext2_xattr_user_list, 75 .get = ext2_xattr_user_get, 76 .set = ext2_xattr_user_set, 77 }; 78