1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Portions of this software were developed under sponsorship from Snow 8 * B.V., the Netherlands. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 __FBSDID("$FreeBSD$"); 35 #endif /* not lint */ 36 37 #include "namespace.h" 38 #include <sys/param.h> 39 #include <sys/ioctl.h> 40 41 #include <errno.h> 42 #include <paths.h> 43 #include <stdlib.h> 44 #include "un-namespace.h" 45 46 /* 47 * __isptmaster(): return whether the file descriptor refers to a 48 * pseudo-terminal master device. 49 */ 50 static int 51 __isptmaster(int fildes) 52 { 53 54 if (_ioctl(fildes, TIOCPTMASTER) == 0) 55 return (0); 56 57 if (errno != EBADF) 58 errno = EINVAL; 59 60 return (-1); 61 } 62 63 /* 64 * In our implementation, grantpt() and unlockpt() don't actually have 65 * any use, because PTY's are created on the fly and already have proper 66 * permissions upon creation. 67 * 68 * Just make sure `fildes' actually points to a real PTY master device. 69 */ 70 __strong_reference(__isptmaster, grantpt); 71 __strong_reference(__isptmaster, unlockpt); 72 73 /* 74 * ptsname(): return the pathname of the slave pseudo-terminal device 75 * associated with the specified master. 76 */ 77 char * 78 ptsname(int fildes) 79 { 80 static char pt_slave[sizeof _PATH_DEV + SPECNAMELEN] = _PATH_DEV; 81 char *ret = NULL; 82 83 /* Make sure fildes points to a master device. */ 84 if (__isptmaster(fildes) != 0) 85 goto done; 86 87 if (fdevname_r(fildes, pt_slave + (sizeof _PATH_DEV - 1), 88 sizeof pt_slave - (sizeof _PATH_DEV - 1)) != NULL) 89 ret = pt_slave; 90 91 done: 92 return (ret); 93 } 94