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 * @(#)pty.c 8.3 (Berkeley) 5/16/94 34 * $FreeBSD: src/lib/libutil/pty.c,v 1.10 1999/08/28 00:05:51 peter Exp $ 35 * $DragonFly: src/lib/libutil/pty.c,v 1.5 2005/03/04 05:22:57 cpressey Exp $ 36 */ 37 38 #include <sys/types.h> 39 #include <sys/ioctl.h> 40 #include <sys/stat.h> 41 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <grp.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <termios.h> 48 #include <unistd.h> 49 50 #include "libutil.h" 51 52 int 53 openpty(int *amaster, int *aslave, char *name, struct termios *termp, 54 struct winsize *winp) 55 { 56 char line[] = "/dev/ptyXX"; 57 const char *cp1, *cp2; 58 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 = "pqrsPQRS"; *cp1; cp1++) { 67 line[8] = *cp1; 68 for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) { 69 line[5] = 'p'; 70 line[9] = *cp2; 71 if ((master = open(line, O_RDWR, 0)) == -1) { 72 if (errno == ENOENT) 73 return (-1); /* out of ptys */ 74 } else { 75 line[5] = 't'; 76 (void) chown(line, getuid(), ttygid); 77 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 78 (void) revoke(line); 79 if ((slave = open(line, O_RDWR, 0)) != -1) { 80 *amaster = master; 81 *aslave = slave; 82 if (name) 83 strcpy(name, line); 84 if (termp) 85 (void) tcsetattr(slave, 86 TCSAFLUSH, termp); 87 if (winp) 88 (void) ioctl(slave, TIOCSWINSZ, 89 (char *)winp); 90 return (0); 91 } 92 (void) close(master); 93 } 94 } 95 } 96 errno = ENOENT; /* out of ptys */ 97 return (-1); 98 } 99 100 int 101 forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp) 102 { 103 int master, slave, pid; 104 105 if (openpty(&master, &slave, name, termp, winp) == -1) 106 return (-1); 107 switch (pid = fork()) { 108 case -1: 109 return (-1); 110 case 0: 111 /* 112 * child 113 */ 114 (void) close(master); 115 login_tty(slave); 116 return (0); 117 } 118 /* 119 * parent 120 */ 121 *amaster = master; 122 (void) close(slave); 123 return (pid); 124 } 125