1 /*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. 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 #if 0 36 static char sccsid[] = "@(#)pty.c 8.3 (Berkeley) 5/16/94"; 37 #else 38 static const char rcsid[] = 39 "$Id$"; 40 #endif 41 #endif /* LIBC_SCCS and not lint */ 42 43 #include <sys/types.h> 44 #include <sys/ioctl.h> 45 #include <sys/stat.h> 46 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <grp.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <termios.h> 54 #include <unistd.h> 55 #include <libutil.h> 56 57 int 58 openpty(amaster, aslave, name, termp, winp) 59 int *amaster, *aslave; 60 char *name; 61 struct termios *termp; 62 struct winsize *winp; 63 { 64 static char line[] = "/dev/ptyXX"; 65 register const char *cp1, *cp2; 66 register int master, slave, ttygid; 67 struct group *gr; 68 69 if ((gr = getgrnam("tty")) != NULL) 70 ttygid = gr->gr_gid; 71 else 72 ttygid = -1; 73 74 for (cp1 = "pqrsPQRS"; *cp1; cp1++) { 75 line[8] = *cp1; 76 for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) { 77 line[5] = 'p'; 78 line[9] = *cp2; 79 if ((master = open(line, O_RDWR, 0)) == -1) { 80 if (errno == ENOENT) 81 return (-1); /* out of ptys */ 82 } else { 83 line[5] = 't'; 84 (void) chown(line, getuid(), ttygid); 85 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 86 (void) revoke(line); 87 if ((slave = open(line, O_RDWR, 0)) != -1) { 88 *amaster = master; 89 *aslave = slave; 90 if (name) 91 strcpy(name, line); 92 if (termp) 93 (void) tcsetattr(slave, 94 TCSAFLUSH, termp); 95 if (winp) 96 (void) ioctl(slave, TIOCSWINSZ, 97 (char *)winp); 98 return (0); 99 } 100 (void) close(master); 101 } 102 } 103 } 104 errno = ENOENT; /* out of ptys */ 105 return (-1); 106 } 107 108 int 109 forkpty(amaster, name, termp, winp) 110 int *amaster; 111 char *name; 112 struct termios *termp; 113 struct winsize *winp; 114 { 115 int master, slave, pid; 116 117 if (openpty(&master, &slave, name, termp, winp) == -1) 118 return (-1); 119 switch (pid = fork()) { 120 case -1: 121 return (-1); 122 case 0: 123 /* 124 * child 125 */ 126 (void) close(master); 127 login_tty(slave); 128 return (0); 129 } 130 /* 131 * parent 132 */ 133 *amaster = master; 134 (void) close(slave); 135 return (pid); 136 } 137