1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2008 Ed Schouten <[email protected]>
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 <string.h>
45 #include "un-namespace.h"
46
47 /*
48 * __isptmaster(): return whether the file descriptor refers to a
49 * pseudo-terminal master device.
50 */
51 static int
__isptmaster(int fildes)52 __isptmaster(int fildes)
53 {
54
55 if (_ioctl(fildes, TIOCPTMASTER) == 0)
56 return (0);
57
58 if (errno != EBADF)
59 errno = EINVAL;
60
61 return (-1);
62 }
63
64 /*
65 * In our implementation, grantpt() and unlockpt() don't actually have
66 * any use, because PTY's are created on the fly and already have proper
67 * permissions upon creation.
68 *
69 * Just make sure `fildes' actually points to a real PTY master device.
70 */
71 __strong_reference(__isptmaster, grantpt);
72 __strong_reference(__isptmaster, unlockpt);
73
74 /*
75 * ptsname_r(): return the pathname of the slave pseudo-terminal device
76 * associated with the specified master.
77 */
78 int
__ptsname_r(int fildes,char * buffer,size_t buflen)79 __ptsname_r(int fildes, char *buffer, size_t buflen)
80 {
81
82 if (buflen <= sizeof(_PATH_DEV)) {
83 errno = ERANGE;
84 return (-1);
85 }
86
87 /* Make sure fildes points to a master device. */
88 if (__isptmaster(fildes) != 0)
89 return (-1);
90
91 memcpy(buffer, _PATH_DEV, sizeof(_PATH_DEV));
92 buffer += sizeof(_PATH_DEV) - 1;
93 buflen -= sizeof(_PATH_DEV) - 1;
94
95 if (fdevname_r(fildes, buffer, buflen) == NULL) {
96 if (errno == EINVAL)
97 errno = ERANGE;
98 return (-1);
99 }
100
101 return (0);
102 }
103
104 __strong_reference(__ptsname_r, ptsname_r);
105
106 /*
107 * ptsname(): return the pathname of the slave pseudo-terminal device
108 * associated with the specified master.
109 */
110 char *
ptsname(int fildes)111 ptsname(int fildes)
112 {
113 static char pt_slave[sizeof(_PATH_DEV) + SPECNAMELEN];
114
115 if (__ptsname_r(fildes, pt_slave, sizeof(pt_slave)) == 0)
116 return (pt_slave);
117
118 return (NULL);
119 }
120