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 #if 0 36 static char sccsid[] = "@(#)pty.c 8.1 (Berkeley) 6/4/93"; 37 #else 38 static char rcsid[] = "$NetBSD: pty.c,v 1.6 1996/05/15 21:42:33 jtc Exp $"; 39 #endif 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/cdefs.h> 43 #include <sys/types.h> 44 #include <sys/stat.h> 45 #include <sys/ioctl.h> 46 #include <fcntl.h> 47 #include <termios.h> 48 #include <errno.h> 49 #include <unistd.h> 50 #include <stdio.h> 51 #include <string.h> 52 #include <grp.h> 53 #include <util.h> 54 55 #ifdef i386 56 /* PCVT conflicts with ttyv*. */ 57 #define TTY_LETTERS "pqrstuwxyzPQRST" 58 #else 59 #define TTY_LETTERS "pqrstuvwxyzPQRST" 60 #endif 61 62 int 63 openpty(amaster, aslave, name, termp, winp) 64 int *amaster, *aslave; 65 char *name; 66 struct termios *termp; 67 struct winsize *winp; 68 { 69 static char line[] = "/dev/ptyXX"; 70 register const char *cp1, *cp2; 71 register int master, slave, ttygid; 72 struct group *gr; 73 74 if ((gr = getgrnam("tty")) != NULL) 75 ttygid = gr->gr_gid; 76 else 77 ttygid = -1; 78 79 for (cp1 = TTY_LETTERS; *cp1; cp1++) { 80 line[8] = *cp1; 81 for (cp2 = "0123456789abcdef"; *cp2; cp2++) { 82 line[9] = *cp2; 83 if ((master = open(line, O_RDWR, 0)) == -1) { 84 if (errno == ENOENT) 85 return (-1); /* out of ptys */ 86 } else { 87 line[5] = 't'; 88 (void) chown(line, getuid(), ttygid); 89 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 90 (void) revoke(line); 91 if ((slave = open(line, O_RDWR, 0)) != -1) { 92 *amaster = master; 93 *aslave = slave; 94 if (name) 95 strcpy(name, line); 96 if (termp) 97 (void) tcsetattr(slave, 98 TCSAFLUSH, termp); 99 if (winp) 100 (void) ioctl(slave, TIOCSWINSZ, 101 (char *)winp); 102 return (0); 103 } 104 (void) close(master); 105 line[5] = 'p'; 106 } 107 } 108 } 109 errno = ENOENT; /* out of ptys */ 110 return (-1); 111 } 112 113 pid_t 114 forkpty(amaster, name, termp, winp) 115 int *amaster; 116 char *name; 117 struct termios *termp; 118 struct winsize *winp; 119 { 120 int master, slave; 121 pid_t pid; 122 123 if (openpty(&master, &slave, name, termp, winp) == -1) 124 return (-1); 125 switch (pid = fork()) { 126 case -1: 127 return (-1); 128 case 0: 129 /* 130 * child 131 */ 132 (void) close(master); 133 login_tty(slave); 134 return (0); 135 } 136 /* 137 * parent 138 */ 139 *amaster = master; 140 (void) close(slave); 141 return (pid); 142 } 143