1 /*- 2 * Copyright (c) 1990, 1993 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 /* from: static char sccsid[] = "@(#)pty.c 8.1 (Berkeley) 6/4/93"; */ 36 static char *rcsid = "$Id: pty.c,v 1.5 1995/06/05 19:44:01 pk Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/cdefs.h> 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <sys/ioctl.h> 43 #include <fcntl.h> 44 #include <termios.h> 45 #include <errno.h> 46 #include <unistd.h> 47 #include <stdio.h> 48 #include <string.h> 49 #include <grp.h> 50 51 int login_tty __P((int)); 52 int openpty __P((int *, int *, char *, struct termios *, struct winsize *)); 53 pid_t forkpty __P((int *, char *, struct termios *, struct winsize *)); 54 55 int 56 openpty(amaster, aslave, name, termp, winp) 57 int *amaster, *aslave; 58 char *name; 59 struct termios *termp; 60 struct winsize *winp; 61 { 62 static char line[] = "/dev/ptyXX"; 63 register const char *cp1, *cp2; 64 register int master, slave, ttygid; 65 struct group *gr; 66 67 if ((gr = getgrnam("tty")) != NULL) 68 ttygid = gr->gr_gid; 69 else 70 ttygid = -1; 71 72 for (cp1 = "pqrstuvwxyzPQRST"; *cp1; cp1++) { 73 line[8] = *cp1; 74 for (cp2 = "0123456789abcdef"; *cp2; cp2++) { 75 line[9] = *cp2; 76 if ((master = open(line, O_RDWR, 0)) == -1) { 77 if (errno == ENOENT) 78 return (-1); /* out of ptys */ 79 } else { 80 line[5] = 't'; 81 (void) chown(line, getuid(), ttygid); 82 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 83 (void) revoke(line); 84 if ((slave = open(line, O_RDWR, 0)) != -1) { 85 *amaster = master; 86 *aslave = slave; 87 if (name) 88 strcpy(name, line); 89 if (termp) 90 (void) tcsetattr(slave, 91 TCSAFLUSH, termp); 92 if (winp) 93 (void) ioctl(slave, TIOCSWINSZ, 94 (char *)winp); 95 return (0); 96 } 97 (void) close(master); 98 line[5] = 'p'; 99 } 100 } 101 } 102 errno = ENOENT; /* out of ptys */ 103 return (-1); 104 } 105 106 pid_t 107 forkpty(amaster, name, termp, winp) 108 int *amaster; 109 char *name; 110 struct termios *termp; 111 struct winsize *winp; 112 { 113 int master, slave; 114 pid_t pid; 115 116 if (openpty(&master, &slave, name, termp, winp) == -1) 117 return (-1); 118 switch (pid = fork()) { 119 case -1: 120 return (-1); 121 case 0: 122 /* 123 * child 124 */ 125 (void) close(master); 126 login_tty(slave); 127 return (0); 128 } 129 /* 130 * parent 131 */ 132 *amaster = master; 133 (void) close(slave); 134 return (pid); 135 } 136