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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)pty.c 8.3 (Berkeley) 5/16/94 30 * $FreeBSD: src/lib/libutil/pty.c,v 1.10 1999/08/28 00:05:51 peter Exp $ 31 * $DragonFly: src/lib/libutil/pty.c,v 1.6 2007/12/30 13:44:33 matthias Exp $ 32 */ 33 34 #include <sys/types.h> 35 #include <sys/ioctl.h> 36 #include <sys/stat.h> 37 38 #include <errno.h> 39 #include <fcntl.h> 40 #include <grp.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <termios.h> 44 #include <unistd.h> 45 46 #include "libutil.h" 47 48 int 49 openpty(int *amaster, int *aslave, char *name, struct termios *termp, 50 struct winsize *winp) 51 { 52 char line[] = "/dev/ptyXX"; 53 const char *cp1, *cp2; 54 int master, slave, ttygid; 55 struct group *gr; 56 57 if ((gr = getgrnam("tty")) != NULL) 58 ttygid = gr->gr_gid; 59 else 60 ttygid = -1; 61 62 for (cp1 = "pqrsPQRS"; *cp1; cp1++) { 63 line[8] = *cp1; 64 for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) { 65 line[5] = 'p'; 66 line[9] = *cp2; 67 if ((master = open(line, O_RDWR, 0)) == -1) { 68 if (errno == ENOENT) 69 return (-1); /* out of ptys */ 70 } else { 71 line[5] = 't'; 72 (void) chown(line, getuid(), ttygid); 73 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 74 (void) revoke(line); 75 if ((slave = open(line, O_RDWR, 0)) != -1) { 76 *amaster = master; 77 *aslave = slave; 78 if (name) 79 strcpy(name, line); 80 if (termp) 81 (void) tcsetattr(slave, 82 TCSAFLUSH, termp); 83 if (winp) 84 (void) ioctl(slave, TIOCSWINSZ, 85 (char *)winp); 86 return (0); 87 } 88 (void) close(master); 89 } 90 } 91 } 92 errno = ENOENT; /* out of ptys */ 93 return (-1); 94 } 95 96 int 97 forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp) 98 { 99 int master, slave, pid; 100 101 if (openpty(&master, &slave, name, termp, winp) == -1) 102 return (-1); 103 switch (pid = fork()) { 104 case -1: 105 return (-1); 106 case 0: 107 /* 108 * child 109 */ 110 (void) close(master); 111 login_tty(slave); 112 return (0); 113 } 114 /* 115 * parent 116 */ 117 *amaster = master; 118 (void) close(slave); 119 return (pid); 120 } 121