1 /* $NetBSD: pty.c,v 1.8 1997/06/29 18:44:09 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)pty.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: pty.c,v 1.8 1997/06/29 18:44:09 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <sys/types.h> 46 #include <sys/stat.h> 47 #include <sys/ioctl.h> 48 #include <fcntl.h> 49 #include <termios.h> 50 #include <errno.h> 51 #include <unistd.h> 52 #include <stdio.h> 53 #include <string.h> 54 #include <grp.h> 55 #include <util.h> 56 57 #ifdef i386 58 /* PCVT conflicts with ttyv*. */ 59 #define TTY_LETTERS "pqrstuwxyzPQRST" 60 #else 61 #define TTY_LETTERS "pqrstuvwxyzPQRST" 62 #endif 63 64 int 65 openpty(amaster, aslave, name, termp, winp) 66 int *amaster, *aslave; 67 char *name; 68 struct termios *termp; 69 struct winsize *winp; 70 { 71 static char line[] = "/dev/XtyXX"; 72 register const char *cp1, *cp2; 73 register int master, slave, ttygid; 74 struct group *gr; 75 76 if ((gr = getgrnam("tty")) != NULL) 77 ttygid = gr->gr_gid; 78 else 79 ttygid = -1; 80 81 line[5] = 'p'; 82 for (cp1 = TTY_LETTERS; *cp1; cp1++) { 83 line[8] = *cp1; 84 for (cp2 = "0123456789abcdef"; *cp2; cp2++) { 85 line[9] = *cp2; 86 if ((master = open(line, O_RDWR, 0)) == -1) { 87 if (errno == ENOENT) 88 return (-1); /* out of ptys */ 89 } else { 90 line[5] = 't'; 91 (void) chown(line, getuid(), ttygid); 92 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 93 (void) revoke(line); 94 if ((slave = open(line, O_RDWR, 0)) != -1) { 95 *amaster = master; 96 *aslave = slave; 97 if (name) 98 strcpy(name, line); 99 if (termp) 100 (void) tcsetattr(slave, 101 TCSAFLUSH, termp); 102 if (winp) 103 (void) ioctl(slave, TIOCSWINSZ, 104 (char *)winp); 105 return (0); 106 } 107 (void) close(master); 108 line[5] = 'p'; 109 } 110 } 111 } 112 errno = ENOENT; /* out of ptys */ 113 return (-1); 114 } 115 116 pid_t 117 forkpty(amaster, name, termp, winp) 118 int *amaster; 119 char *name; 120 struct termios *termp; 121 struct winsize *winp; 122 { 123 int master, slave; 124 pid_t pid; 125 126 if (openpty(&master, &slave, name, termp, winp) == -1) 127 return (-1); 128 switch (pid = fork()) { 129 case -1: 130 return (-1); 131 case 0: 132 /* 133 * child 134 */ 135 (void) close(master); 136 login_tty(slave); 137 return (0); 138 } 139 /* 140 * parent 141 */ 142 *amaster = master; 143 (void) close(slave); 144 return (pid); 145 } 146