1 /* $NetBSD: pty.c,v 1.22 2004/05/27 03:12:48 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993, 1994 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)pty.c 8.3 (Berkeley) 5/16/94"; 36 #else 37 __RCSID("$NetBSD: pty.c,v 1.22 2004/05/27 03:12:48 christos Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/types.h> 42 #include <sys/ioctl.h> 43 #include <sys/stat.h> 44 45 #include <assert.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <grp.h> 49 #include <stdio.h> 50 #include <string.h> 51 #include <termios.h> 52 #include <unistd.h> 53 #include <util.h> 54 55 /* 56 * XXX: `v' removed until no ports are using console devices which use ttyv0 57 */ 58 #define TTY_LETTERS "pqrstuwxyzPQRST" 59 #define TTY_OLD_SUFFIX "0123456789abcdef" 60 #define TTY_NEW_SUFFIX "ghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" 61 62 int 63 openpty(int *amaster, int *aslave, char *name, struct termios *termp, 64 struct winsize *winp) 65 { 66 static char line[] = "/dev/XtyXX"; 67 const char *cp1, *cp2, *cp, *linep; 68 int master, slave; 69 gid_t ttygid; 70 struct group *gr; 71 72 _DIAGASSERT(amaster != NULL); 73 _DIAGASSERT(aslave != NULL); 74 /* name may be NULL */ 75 /* termp may be NULL */ 76 /* winp may be NULL */ 77 78 if ((master = open("/dev/ptm", O_RDWR)) != -1) { 79 struct ptmget pt; 80 if (ioctl(master, TIOCPTMGET, &pt) != -1) { 81 (void)close(master); 82 master = pt.cfd; 83 slave = pt.sfd; 84 linep = pt.sn; 85 goto gotit; 86 } 87 } 88 89 if ((gr = getgrnam("tty")) != NULL) 90 ttygid = gr->gr_gid; 91 else 92 ttygid = (gid_t) -1; 93 94 for (cp1 = TTY_LETTERS; *cp1; cp1++) { 95 line[8] = *cp1; 96 for (cp = cp2 = TTY_OLD_SUFFIX TTY_NEW_SUFFIX; *cp2; cp2++) { 97 line[5] = 'p'; 98 line[9] = *cp2; 99 if ((master = open(line, O_RDWR, 0)) == -1) { 100 if (errno == ENOENT) { 101 if (cp2 - cp + 1 < sizeof(TTY_OLD_SUFFIX)) 102 return (-1); /* out of ptys */ 103 else 104 break; 105 } 106 } else { 107 line[5] = 't'; 108 (void) chown(line, getuid(), ttygid); 109 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 110 (void) revoke(line); 111 linep = line; 112 if ((slave = open(line, O_RDWR, 0)) != -1) { 113 gotit: 114 *amaster = master; 115 *aslave = slave; 116 if (name) 117 strcpy(name, linep); 118 if (termp) 119 (void) tcsetattr(slave, 120 TCSAFLUSH, termp); 121 if (winp) 122 (void) ioctl(slave, TIOCSWINSZ, 123 winp); 124 return (0); 125 } 126 (void) close(master); 127 } 128 } 129 } 130 errno = ENOENT; /* out of ptys */ 131 return (-1); 132 } 133 134 pid_t 135 forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp) 136 { 137 int master, slave; 138 pid_t pid; 139 140 _DIAGASSERT(amaster != NULL); 141 /* name may be NULL */ 142 /* termp may be NULL */ 143 /* winp may be NULL */ 144 145 if (openpty(&master, &slave, name, termp, winp) == -1) 146 return (-1); 147 switch (pid = fork()) { 148 case -1: 149 return (-1); 150 case 0: 151 /* 152 * child 153 */ 154 (void) close(master); 155 login_tty(slave); 156 return (0); 157 } 158 /* 159 * parent 160 */ 161 *amaster = master; 162 (void) close(slave); 163 return (pid); 164 } 165