1 /*- 2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Portions of this software were developed under sponsorship from Snow 6 * B.V., the Netherlands. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 #ifndef lint 32 __FBSDID("$FreeBSD$"); 33 #endif /* not lint */ 34 35 #include "namespace.h" 36 #include <sys/param.h> 37 #include <sys/ioctl.h> 38 39 #include <errno.h> 40 #include <paths.h> 41 #include "un-namespace.h" 42 43 /* 44 * __isptmaster(): return whether the file descriptor refers to a 45 * pseudo-terminal master device. 46 */ 47 static int 48 __isptmaster(int fildes) 49 { 50 51 if (_ioctl(fildes, TIOCPTMASTER) == 0) 52 return (0); 53 54 if (errno != EBADF) 55 errno = EINVAL; 56 57 return (-1); 58 } 59 60 /* 61 * In our implementation, grantpt() and unlockpt() don't actually have 62 * any use, because PTY's are created on the fly and already have proper 63 * permissions upon creation. 64 * 65 * Just make sure `fildes' actually points to a real PTY master device. 66 */ 67 __strong_reference(__isptmaster, grantpt); 68 __strong_reference(__isptmaster, unlockpt); 69 70 /* 71 * ptsname(): return the pathname of the slave pseudo-terminal device 72 * associated with the specified master. 73 */ 74 char * 75 ptsname(int fildes) 76 { 77 static char pt_slave[sizeof _PATH_DEV + SPECNAMELEN] = _PATH_DEV; 78 struct fiodgname_arg fgn; 79 char *ret = NULL; 80 int sverrno = errno; 81 82 /* Make sure fildes points to a master device. */ 83 if (__isptmaster(fildes) != 0) 84 goto done; 85 86 /* Obtain the device name through FIODGNAME. */ 87 fgn.len = sizeof pt_slave - (sizeof _PATH_DEV - 1); 88 fgn.buf = pt_slave + (sizeof _PATH_DEV - 1); 89 if (_ioctl(fildes, FIODGNAME, &fgn) == 0) 90 ret = pt_slave; 91 92 done: /* Make sure ptsname() does not overwrite errno. */ 93 errno = sverrno; 94 return (ret); 95 } 96