1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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 #ifndef lint
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 <stdlib.h>
42 #include <string.h>
43 #include "un-namespace.h"
44
45 /*
46 * __isptmaster(): return whether the file descriptor refers to a
47 * pseudo-terminal master device.
48 */
49 static int
__isptmaster(int fildes)50 __isptmaster(int fildes)
51 {
52
53 if (_ioctl(fildes, TIOCPTMASTER) == 0)
54 return (0);
55
56 if (errno != EBADF)
57 errno = EINVAL;
58
59 return (-1);
60 }
61
62 /*
63 * In our implementation, grantpt() and unlockpt() don't actually have
64 * any use, because PTY's are created on the fly and already have proper
65 * permissions upon creation.
66 *
67 * Just make sure `fildes' actually points to a real PTY master device.
68 */
69 __strong_reference(__isptmaster, grantpt);
70 __strong_reference(__isptmaster, unlockpt);
71
72 /*
73 * ptsname_r(): return the pathname of the slave pseudo-terminal device
74 * associated with the specified master.
75 */
76 int
__ptsname_r(int fildes,char * buffer,size_t buflen)77 __ptsname_r(int fildes, char *buffer, size_t buflen)
78 {
79
80 if (buflen <= sizeof(_PATH_DEV)) {
81 errno = ERANGE;
82 return (-1);
83 }
84
85 /* Make sure fildes points to a master device. */
86 if (__isptmaster(fildes) != 0)
87 return (-1);
88
89 memcpy(buffer, _PATH_DEV, sizeof(_PATH_DEV));
90 buffer += sizeof(_PATH_DEV) - 1;
91 buflen -= sizeof(_PATH_DEV) - 1;
92
93 if (fdevname_r(fildes, buffer, buflen) == NULL) {
94 if (errno == EINVAL)
95 errno = ERANGE;
96 return (-1);
97 }
98
99 return (0);
100 }
101
102 __strong_reference(__ptsname_r, ptsname_r);
103
104 /*
105 * ptsname(): return the pathname of the slave pseudo-terminal device
106 * associated with the specified master.
107 */
108 char *
ptsname(int fildes)109 ptsname(int fildes)
110 {
111 static char pt_slave[sizeof(_PATH_DEV) + SPECNAMELEN];
112
113 if (__ptsname_r(fildes, pt_slave, sizeof(pt_slave)) == 0)
114 return (pt_slave);
115
116 return (NULL);
117 }
118