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