1 #include "reiserfs.h" 2 #include <linux/errno.h> 3 #include <linux/fs.h> 4 #include <linux/pagemap.h> 5 #include <linux/xattr.h> 6 #include <linux/slab.h> 7 #include "xattr.h" 8 #include <linux/security.h> 9 #include <linux/uaccess.h> 10 11 static int 12 security_get(const struct xattr_handler *handler, struct dentry *dentry, 13 const char *name, void *buffer, size_t size) 14 { 15 if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX)) 16 return -EINVAL; 17 18 if (IS_PRIVATE(d_inode(dentry))) 19 return -EPERM; 20 21 return reiserfs_xattr_get(d_inode(dentry), name, buffer, size); 22 } 23 24 static int 25 security_set(const struct xattr_handler *handler, struct dentry *dentry, 26 const char *name, const void *buffer, size_t size, int flags) 27 { 28 if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX)) 29 return -EINVAL; 30 31 if (IS_PRIVATE(d_inode(dentry))) 32 return -EPERM; 33 34 return reiserfs_xattr_set(d_inode(dentry), name, buffer, size, flags); 35 } 36 37 static size_t security_list(const struct xattr_handler *handler, 38 struct dentry *dentry, char *list, size_t list_len, 39 const char *name, size_t namelen) 40 { 41 const size_t len = namelen + 1; 42 43 if (IS_PRIVATE(d_inode(dentry))) 44 return 0; 45 46 if (list && len <= list_len) { 47 memcpy(list, name, namelen); 48 list[namelen] = '\0'; 49 } 50 51 return len; 52 } 53 54 /* Initializes the security context for a new inode and returns the number 55 * of blocks needed for the transaction. If successful, reiserfs_security 56 * must be released using reiserfs_security_free when the caller is done. */ 57 int reiserfs_security_init(struct inode *dir, struct inode *inode, 58 const struct qstr *qstr, 59 struct reiserfs_security_handle *sec) 60 { 61 int blocks = 0; 62 int error; 63 64 sec->name = NULL; 65 66 /* Don't add selinux attributes on xattrs - they'll never get used */ 67 if (IS_PRIVATE(dir)) 68 return 0; 69 70 error = security_old_inode_init_security(inode, dir, qstr, &sec->name, 71 &sec->value, &sec->length); 72 if (error) { 73 if (error == -EOPNOTSUPP) 74 error = 0; 75 76 sec->name = NULL; 77 sec->value = NULL; 78 sec->length = 0; 79 return error; 80 } 81 82 if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) { 83 blocks = reiserfs_xattr_jcreate_nblocks(inode) + 84 reiserfs_xattr_nblocks(inode, sec->length); 85 /* We don't want to count the directories twice if we have 86 * a default ACL. */ 87 REISERFS_I(inode)->i_flags |= i_has_xattr_dir; 88 } 89 return blocks; 90 } 91 92 int reiserfs_security_write(struct reiserfs_transaction_handle *th, 93 struct inode *inode, 94 struct reiserfs_security_handle *sec) 95 { 96 int error; 97 if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX)) 98 return -EINVAL; 99 100 error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value, 101 sec->length, XATTR_CREATE); 102 if (error == -ENODATA || error == -EOPNOTSUPP) 103 error = 0; 104 105 return error; 106 } 107 108 void reiserfs_security_free(struct reiserfs_security_handle *sec) 109 { 110 kfree(sec->name); 111 kfree(sec->value); 112 sec->name = NULL; 113 sec->value = NULL; 114 } 115 116 const struct xattr_handler reiserfs_xattr_security_handler = { 117 .prefix = XATTR_SECURITY_PREFIX, 118 .get = security_get, 119 .set = security_set, 120 .list = security_list, 121 }; 122