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 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)pty.c 8.3 (Berkeley) 5/16/94"; 36 #endif 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/types.h> 40 #include <sys/ioctl.h> 41 #include <sys/stat.h> 42 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <grp.h> 46 #include <libutil.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <termios.h> 50 #include <unistd.h> 51 52 int __use_pts(void); 53 54 static int 55 new_openpty(int *amaster, int *aslave, char *name, struct termios *termp, 56 struct winsize *winp) 57 { 58 int master, slave; 59 60 master = posix_openpt(O_RDWR); 61 if (master == -1) 62 return (-1); 63 64 if (grantpt(master) == -1) { 65 close(master); 66 return (-1); 67 } 68 69 slave = open(ptsname(master), O_RDWR); 70 if (slave == -1) { 71 close(master); 72 return (-1); 73 } 74 75 if (unlockpt(master) == -1) { 76 close(master); 77 close(slave); 78 return (-1); 79 } 80 81 *amaster = master; 82 *aslave = slave; 83 84 if (name) 85 strcpy(name, ptsname(master)); 86 if (termp) 87 tcsetattr(slave, TCSAFLUSH, termp); 88 if (winp) 89 ioctl(slave, TIOCSWINSZ, (char *)winp); 90 91 return (0); 92 } 93 94 int 95 openpty(int *amaster, int *aslave, char *name, struct termios *termp, struct winsize *winp) 96 { 97 char line[] = "/dev/ptyXX"; 98 const char *cp1, *cp2; 99 int master, slave, ttygid; 100 struct group *gr; 101 102 if (__use_pts()) 103 return (new_openpty(amaster, aslave, name, termp, winp)); 104 105 if ((gr = getgrnam("tty")) != NULL) 106 ttygid = gr->gr_gid; 107 else 108 ttygid = -1; 109 110 for (cp1 = "pqrsPQRS"; *cp1; cp1++) { 111 line[8] = *cp1; 112 for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) { 113 line[5] = 'p'; 114 line[9] = *cp2; 115 if ((master = open(line, O_RDWR, 0)) == -1) { 116 if (errno == ENOENT) 117 break; /* try the next pty group */ 118 } else { 119 line[5] = 't'; 120 (void) chown(line, getuid(), ttygid); 121 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 122 (void) revoke(line); 123 if ((slave = open(line, O_RDWR, 0)) != -1) { 124 *amaster = master; 125 *aslave = slave; 126 if (name) 127 strcpy(name, line); 128 if (termp) 129 (void) tcsetattr(slave, 130 TCSAFLUSH, termp); 131 if (winp) 132 (void) ioctl(slave, TIOCSWINSZ, 133 (char *)winp); 134 return (0); 135 } 136 (void) close(master); 137 } 138 } 139 } 140 errno = ENOENT; /* out of ptys */ 141 return (-1); 142 } 143 144 int 145 forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp) 146 { 147 int master, slave, pid; 148 149 if (openpty(&master, &slave, name, termp, winp) == -1) 150 return (-1); 151 switch (pid = fork()) { 152 case -1: 153 return (-1); 154 case 0: 155 /* 156 * child 157 */ 158 (void) close(master); 159 login_tty(slave); 160 return (0); 161 } 162 /* 163 * parent 164 */ 165 *amaster = master; 166 (void) close(slave); 167 return (pid); 168 } 169