1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
29 * Copyright 2024 Oxide Computer Company
30 */
31
32 /* Copyright (c) 1988 AT&T */
33 /* All Rights Reserved */
34
35 #pragma weak _ptsname = ptsname
36 #pragma weak _grantpt = grantpt
37 #pragma weak _unlockpt = unlockpt
38
39 #include "lint.h"
40 #include "libc.h"
41 #include "mtlib.h"
42 #include <sys/types.h>
43 #include <signal.h>
44 #include <sys/param.h>
45 #include <sys/mkdev.h>
46 #include <sys/stream.h>
47 #include <sys/stropts.h>
48 #include <sys/wait.h>
49 #include <sys/signal.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <sys/stat.h>
53 #include <sys/ptms.h>
54 #include <string.h>
55 #include <stdlib.h>
56 #include <unistd.h>
57 #include <wait.h>
58 #include <spawn.h>
59 #include <grp.h>
60 #include "tsd.h"
61
62 #define PTSNAME "/dev/pts/" /* slave name */
63 #define PTLEN 32 /* slave name length */
64 #define DEFAULT_TTY_GROUP "tty" /* slave device group owner */
65
66 /*
67 * Check that fd argument is a file descriptor of an opened master.
68 * Do this by sending an ISPTM ioctl message down stream. Ioctl()
69 * will fail if:(1) fd is not a valid file descriptor.(2) the file
70 * represented by fd does not understand ISPTM(not a master device).
71 * If we have a valid master, get its minor number via fstat().
72 * Concatenate it to PTSNAME and return it as the name of the slave
73 * device.
74 */
75 static dev_t
ptsdev(int fd)76 ptsdev(int fd)
77 {
78 struct stat64 status;
79 struct strioctl istr;
80
81 istr.ic_cmd = ISPTM;
82 istr.ic_len = 0;
83 istr.ic_timout = 0;
84 istr.ic_dp = NULL;
85
86 if (ioctl(fd, I_STR, &istr) < 0 || fstat64(fd, &status) < 0)
87 return (NODEV);
88
89 return (minor(status.st_rdev));
90 }
91
92 int
ptsname_r(int fd,char * name,size_t len)93 ptsname_r(int fd, char *name, size_t len)
94 {
95 dev_t dev;
96
97 if (name == NULL)
98 return (EINVAL);
99
100 if ((dev = ptsdev(fd)) == NODEV)
101 return (errno);
102
103 if (snprintf(name, len, "%s%d", PTSNAME, dev) >= len)
104 return (ERANGE);
105
106 /*
107 * This lookup will create the /dev/pts node (if the corresponding pty
108 * exists). POSIX basically never really indicated whether or not
109 * ptsname() was allowed to return errors or not, though we did. If we
110 * played strictly by the book, this should probably be an EINVAL or
111 * ENOTTY return; however, to help someone have a chance of debugging
112 * this if something goes wrong we stick with our traditional behavior
113 * and return a slightly broader errno set. If this causes portability
114 * issues in practice, then it should be changed to just return EINVAL.
115 */
116 if (access(name, F_OK) != 0)
117 return (errno);
118
119 return (0);
120 }
121
122 char *
ptsname(int fd)123 ptsname(int fd)
124 {
125 int ret;
126 char *sname;
127
128 sname = tsdalloc(_T_PTSNAME, PTLEN, NULL);
129 if (sname == NULL)
130 return (NULL);
131
132 if ((ret = ptsname_r(fd, sname, PTLEN)) != 0) {
133 errno = ret;
134 return (NULL);
135 }
136
137 return (sname);
138 }
139
140 /*
141 * Send an ioctl down to the master device requesting the
142 * master/slave pair be unlocked.
143 */
144 int
unlockpt(int fd)145 unlockpt(int fd)
146 {
147 struct strioctl istr;
148
149 istr.ic_cmd = UNLKPT;
150 istr.ic_len = 0;
151 istr.ic_timout = 0;
152 istr.ic_dp = NULL;
153
154 if (ioctl(fd, I_STR, &istr) < 0)
155 return (-1);
156
157 return (0);
158 }
159
160 /*
161 * XPG4v2 requires that open of a slave pseudo terminal device
162 * provides the process with an interface that is identical to
163 * the terminal interface.
164 *
165 * To satisfy this, in strict XPG4v2 mode, this routine also sends
166 * a message down the stream that sets a flag in the kernel module
167 * so that additional actions are performed when opening an
168 * associated slave PTY device. When this happens, modules are
169 * automatically pushed onto the stream to provide terminal
170 * semantics and those modules are then informed that they should
171 * behave in strict XPG4v2 mode which modifies their behaviour. In
172 * particular, in strict XPG4v2 mode, empty blocks will be sent up
173 * the master side of the stream rather than being suppressed.
174 *
175 * Most applications do not expect this behaviour so it is only
176 * enabled for programs compiled in strict XPG4v2 mode (see
177 * stdlib.h).
178 */
179 int
__unlockpt_xpg4(int fd)180 __unlockpt_xpg4(int fd)
181 {
182 int ret;
183
184 if ((ret = unlockpt(fd)) == 0) {
185 struct strioctl istr;
186
187 istr.ic_cmd = PTSSTTY;
188 istr.ic_len = 0;
189 istr.ic_timout = 0;
190 istr.ic_dp = NULL;
191
192 if (ioctl(fd, I_STR, &istr) < 0)
193 ret = -1;
194 }
195
196 return (ret);
197 }
198
199 int
grantpt(int fd)200 grantpt(int fd)
201 {
202 struct strioctl istr;
203 pt_own_t pto;
204 struct group *gr_name;
205
206 /* validate the file descriptor before proceeding */
207 if (ptsdev(fd) == NODEV)
208 return (-1);
209
210 pto.pto_ruid = getuid();
211
212 gr_name = getgrnam(DEFAULT_TTY_GROUP);
213 if (gr_name)
214 pto.pto_rgid = gr_name->gr_gid;
215 else
216 pto.pto_rgid = getgid();
217
218 istr.ic_cmd = OWNERPT;
219 istr.ic_len = sizeof (pt_own_t);
220 istr.ic_timout = 0;
221 istr.ic_dp = (char *)&pto;
222
223 if (ioctl(fd, I_STR, &istr) != 0) {
224 errno = EACCES;
225 return (-1);
226 }
227
228 return (0);
229 }
230
231 /*
232 * Send an ioctl down to the master device requesting the master/slave pair
233 * be assigned to the given zone.
234 */
235 int
zonept(int fd,zoneid_t zoneid)236 zonept(int fd, zoneid_t zoneid)
237 {
238 struct strioctl istr;
239
240 istr.ic_cmd = ZONEPT;
241 istr.ic_len = sizeof (zoneid);
242 istr.ic_timout = 0;
243 istr.ic_dp = (char *)&zoneid;
244
245 if (ioctl(fd, I_STR, &istr) != 0) {
246 return (-1);
247 }
248 return (0);
249 }
250
251
252 /*
253 * added for SUSv3 standard
254 *
255 * Open a pseudo-terminal device. External interface.
256 */
257 int
posix_openpt(int oflag)258 posix_openpt(int oflag)
259 {
260 return (open("/dev/ptmx", oflag));
261 }
262