1 // SPDX-License-Identifier: GPL-2.0 2 #include "reiserfs.h" 3 #include <linux/errno.h> 4 #include <linux/fs.h> 5 #include <linux/pagemap.h> 6 #include <linux/xattr.h> 7 #include <linux/slab.h> 8 #include "xattr.h" 9 #include <linux/security.h> 10 #include <linux/uaccess.h> 11 12 static int 13 security_get(const struct xattr_handler *handler, struct dentry *unused, 14 struct inode *inode, const char *name, void *buffer, size_t size) 15 { 16 if (IS_PRIVATE(inode)) 17 return -EPERM; 18 19 return reiserfs_xattr_get(inode, xattr_full_name(handler, name), 20 buffer, size); 21 } 22 23 static int 24 security_set(const struct xattr_handler *handler, struct dentry *unused, 25 struct inode *inode, const char *name, const void *buffer, 26 size_t size, int flags) 27 { 28 if (IS_PRIVATE(inode)) 29 return -EPERM; 30 31 return reiserfs_xattr_set(inode, 32 xattr_full_name(handler, name), 33 buffer, size, flags); 34 } 35 36 static bool security_list(struct dentry *dentry) 37 { 38 return !IS_PRIVATE(d_inode(dentry)); 39 } 40 41 /* Initializes the security context for a new inode and returns the number 42 * of blocks needed for the transaction. If successful, reiserfs_security 43 * must be released using reiserfs_security_free when the caller is done. */ 44 int reiserfs_security_init(struct inode *dir, struct inode *inode, 45 const struct qstr *qstr, 46 struct reiserfs_security_handle *sec) 47 { 48 int blocks = 0; 49 int error; 50 51 sec->name = NULL; 52 53 /* Don't add selinux attributes on xattrs - they'll never get used */ 54 if (IS_PRIVATE(dir)) 55 return 0; 56 57 error = security_old_inode_init_security(inode, dir, qstr, &sec->name, 58 &sec->value, &sec->length); 59 if (error) { 60 if (error == -EOPNOTSUPP) 61 error = 0; 62 63 sec->name = NULL; 64 sec->value = NULL; 65 sec->length = 0; 66 return error; 67 } 68 69 if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) { 70 blocks = reiserfs_xattr_jcreate_nblocks(inode) + 71 reiserfs_xattr_nblocks(inode, sec->length); 72 /* We don't want to count the directories twice if we have 73 * a default ACL. */ 74 REISERFS_I(inode)->i_flags |= i_has_xattr_dir; 75 } 76 return blocks; 77 } 78 79 int reiserfs_security_write(struct reiserfs_transaction_handle *th, 80 struct inode *inode, 81 struct reiserfs_security_handle *sec) 82 { 83 int error; 84 if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX)) 85 return -EINVAL; 86 87 error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value, 88 sec->length, XATTR_CREATE); 89 if (error == -ENODATA || error == -EOPNOTSUPP) 90 error = 0; 91 92 return error; 93 } 94 95 void reiserfs_security_free(struct reiserfs_security_handle *sec) 96 { 97 kfree(sec->name); 98 kfree(sec->value); 99 sec->name = NULL; 100 sec->value = NULL; 101 } 102 103 const struct xattr_handler reiserfs_xattr_security_handler = { 104 .prefix = XATTR_SECURITY_PREFIX, 105 .get = security_get, 106 .set = security_set, 107 .list = security_list, 108 }; 109