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. 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 #define UNIX98_PTYS 1 49 50 int 51 openpty(int *amaster, int *aslave, char *name, struct termios *termp, 52 struct winsize *winp) 53 { 54 char line[] = "/dev/ptyXX"; 55 const char *cp1, *cp2; 56 int master, slave, ttygid; 57 struct group *gr; 58 const char *slave_name; 59 60 if ((gr = getgrnam("tty")) != NULL) 61 ttygid = gr->gr_gid; 62 else 63 ttygid = -1; 64 65 #ifdef UNIX98_PTYS 66 master = posix_openpt(O_RDWR|O_NOCTTY); 67 if (master == -1) 68 goto fallback; 69 70 if (grantpt(master) != 0) { 71 close(master); 72 goto fallback; 73 } 74 75 if (unlockpt(master) != 0) { 76 close(master); 77 goto fallback; 78 } 79 80 slave_name = ptsname(master); 81 if (slave_name == NULL) { 82 close(master); 83 goto fallback; 84 } 85 86 slave = open(slave_name, O_RDWR); 87 if (slave == -1) { 88 close(master); 89 goto fallback; 90 } 91 92 *amaster = master; 93 *aslave = slave; 94 95 if (name) 96 strcpy(name, slave_name); 97 if (termp) 98 tcsetattr(slave, TCSAFLUSH, termp); 99 if (winp) 100 ioctl(slave, TIOCSWINSZ, (char *)winp); 101 102 return (0); 103 104 fallback: 105 #endif 106 107 for (cp1 = "pqrsPQRS"; *cp1; cp1++) { 108 line[8] = *cp1; 109 for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) { 110 line[5] = 'p'; 111 line[9] = *cp2; 112 if ((master = open(line, O_RDWR, 0)) == -1) { 113 if (errno == ENOENT) 114 return (-1); /* out of ptys */ 115 } else { 116 line[5] = 't'; 117 (void) chown(line, getuid(), ttygid); 118 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 119 (void) revoke(line); 120 if ((slave = open(line, O_RDWR, 0)) != -1) { 121 *amaster = master; 122 *aslave = slave; 123 if (name) 124 strcpy(name, line); 125 if (termp) 126 (void) tcsetattr(slave, 127 TCSAFLUSH, termp); 128 if (winp) 129 (void) ioctl(slave, TIOCSWINSZ, 130 (char *)winp); 131 return (0); 132 } 133 (void) close(master); 134 } 135 } 136 } 137 errno = ENOENT; /* out of ptys */ 138 return (-1); 139 } 140 141 int 142 forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp) 143 { 144 int master, slave, pid; 145 146 if (openpty(&master, &slave, name, termp, winp) == -1) 147 return (-1); 148 switch (pid = fork()) { 149 case -1: 150 return (-1); 151 case 0: 152 /* 153 * child 154 */ 155 (void) close(master); 156 login_tty(slave); 157 return (0); 158 } 159 /* 160 * parent 161 */ 162 *amaster = master; 163 (void) close(slave); 164 return (pid); 165 } 166