1 /*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)pty.c 5.6 (Berkeley) 5/10/91";
36 #endif /* LIBC_SCCS and not lint */
37
38 #include <sys/cdefs.h>
39 #include <sys/types.h>
40 #include <sys/stat.h>
41 #include <sys/ioctl.h>
42 #include <fcntl.h>
43 #include <termios.h>
44 #include <errno.h>
45 #include <unistd.h>
46 #include <stdio.h>
47 #include <string.h>
48 #include <grp.h>
49
openpty(amaster,aslave,name,termp,winp)50 openpty(amaster, aslave, name, termp, winp)
51 int *amaster, *aslave;
52 char *name;
53 struct termios *termp;
54 struct winsize *winp;
55 {
56 static char line[] = "/dev/ptyXX";
57 register const char *cp1, *cp2;
58 register int master, slave, ttygid;
59 struct group *gr;
60
61 if ((gr = getgrnam("tty")) != NULL)
62 ttygid = gr->gr_gid;
63 else
64 ttygid = -1;
65
66 for (cp1 = "pqrs"; *cp1; cp1++) {
67 line[8] = *cp1;
68 for (cp2 = "0123456789abcdef"; *cp2; cp2++) {
69 line[9] = *cp2;
70 if ((master = open(line, O_RDWR, 0)) == -1) {
71 if (errno == ENOENT)
72 return (-1); /* out of ptys */
73 } else {
74 line[5] = 't';
75 (void) chown(line, getuid(), ttygid);
76 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP);
77 (void) revoke(line);
78 if ((slave = open(line, O_RDWR, 0)) != -1) {
79 *amaster = master;
80 *aslave = slave;
81 if (name)
82 strcpy(name, line);
83 if (termp)
84 (void) tcsetattr(slave,
85 TCSAFLUSH, termp);
86 if (winp)
87 (void) ioctl(slave, TIOCSWINSZ,
88 (char *)winp);
89 return (0);
90 }
91 (void) close(master);
92 line[5] = 'p';
93 }
94 }
95 }
96 errno = ENOENT; /* out of ptys */
97 return (-1);
98 }
99
forkpty(amaster,name,termp,winp)100 forkpty(amaster, name, termp, winp)
101 int *amaster;
102 char *name;
103 struct termios *termp;
104 struct winsize *winp;
105 {
106 int master, slave, pid;
107
108 if (openpty(&master, &slave, name, termp, winp) == -1)
109 return (-1);
110 switch (pid = fork()) {
111 case -1:
112 return (-1);
113 case 0:
114 /*
115 * child
116 */
117 (void) close(master);
118 login_tty(slave);
119 return (0);
120 }
121 /*
122 * parent
123 */
124 *amaster = master;
125 (void) close(slave);
126 return (pid);
127 }
128