1 /* 2 * linux/fs/ext2/xattr_security.c 3 * Handler for storing security labels as extended attributes. 4 */ 5 6 #include <linux/module.h> 7 #include <linux/slab.h> 8 #include <linux/string.h> 9 #include <linux/fs.h> 10 #include <linux/ext2_fs.h> 11 #include <linux/security.h> 12 #include "xattr.h" 13 14 static size_t 15 ext2_xattr_security_list(struct dentry *dentry, char *list, size_t list_size, 16 const char *name, size_t name_len, int type) 17 { 18 const int prefix_len = XATTR_SECURITY_PREFIX_LEN; 19 const size_t total_len = prefix_len + name_len + 1; 20 21 if (list && total_len <= list_size) { 22 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len); 23 memcpy(list+prefix_len, name, name_len); 24 list[prefix_len + name_len] = '\0'; 25 } 26 return total_len; 27 } 28 29 static int 30 ext2_xattr_security_get(struct dentry *dentry, const char *name, 31 void *buffer, size_t size, int type) 32 { 33 if (strcmp(name, "") == 0) 34 return -EINVAL; 35 return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name, 36 buffer, size); 37 } 38 39 static int 40 ext2_xattr_security_set(struct dentry *dentry, const char *name, 41 const void *value, size_t size, int flags, int type) 42 { 43 if (strcmp(name, "") == 0) 44 return -EINVAL; 45 return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name, 46 value, size, flags); 47 } 48 49 int 50 ext2_init_security(struct inode *inode, struct inode *dir, 51 const struct qstr *qstr) 52 { 53 int err; 54 size_t len; 55 void *value; 56 char *name; 57 58 err = security_inode_init_security(inode, dir, qstr, &name, &value, &len); 59 if (err) { 60 if (err == -EOPNOTSUPP) 61 return 0; 62 return err; 63 } 64 err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY, 65 name, value, len, 0); 66 kfree(name); 67 kfree(value); 68 return err; 69 } 70 71 const struct xattr_handler ext2_xattr_security_handler = { 72 .prefix = XATTR_SECURITY_PREFIX, 73 .list = ext2_xattr_security_list, 74 .get = ext2_xattr_security_get, 75 .set = ext2_xattr_security_set, 76 }; 77