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 const char *slavename; 59 int master, slave; 60 61 master = posix_openpt(O_RDWR); 62 if (master == -1) 63 return (-1); 64 65 if (grantpt(master) == -1) { 66 close(master); 67 return (-1); 68 } 69 70 slavename = ptsname(master); 71 if (slavename == NULL) { 72 close(master); 73 return (-1); 74 } 75 76 if (revoke(slavename) == -1) { 77 close(master); 78 return (-1); 79 } 80 81 slave = open(slavename, O_RDWR); 82 if (slave == -1) { 83 close(master); 84 return (-1); 85 } 86 87 if (unlockpt(master) == -1) { 88 close(master); 89 close(slave); 90 return (-1); 91 } 92 93 *amaster = master; 94 *aslave = slave; 95 96 if (name) 97 strcpy(name, ptsname(master)); 98 if (termp) 99 tcsetattr(slave, TCSAFLUSH, termp); 100 if (winp) 101 ioctl(slave, TIOCSWINSZ, (char *)winp); 102 103 return (0); 104 } 105 106 int 107 openpty(int *amaster, int *aslave, char *name, struct termios *termp, struct winsize *winp) 108 { 109 char line[] = "/dev/ptyXX"; 110 const char *cp1, *cp2; 111 int master, slave, ttygid; 112 struct group *gr; 113 114 if (__use_pts()) 115 return (new_openpty(amaster, aslave, name, termp, winp)); 116 117 if ((gr = getgrnam("tty")) != NULL) 118 ttygid = gr->gr_gid; 119 else 120 ttygid = -1; 121 122 for (cp1 = "pqrsPQRSlmnoLMNO"; *cp1; cp1++) { 123 line[8] = *cp1; 124 for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) { 125 line[5] = 'p'; 126 line[9] = *cp2; 127 if ((master = open(line, O_RDWR, 0)) == -1) { 128 if (errno == ENOENT) 129 break; /* try the next pty group */ 130 } else { 131 line[5] = 't'; 132 (void) chown(line, getuid(), ttygid); 133 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP); 134 (void) revoke(line); 135 if ((slave = open(line, O_RDWR, 0)) != -1) { 136 *amaster = master; 137 *aslave = slave; 138 if (name) 139 strcpy(name, line); 140 if (termp) 141 (void) tcsetattr(slave, 142 TCSAFLUSH, termp); 143 if (winp) 144 (void) ioctl(slave, TIOCSWINSZ, 145 (char *)winp); 146 return (0); 147 } 148 (void) close(master); 149 } 150 } 151 } 152 errno = ENOENT; /* out of ptys */ 153 return (-1); 154 } 155 156 int 157 forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp) 158 { 159 int master, slave, pid; 160 161 if (openpty(&master, &slave, name, termp, winp) == -1) 162 return (-1); 163 switch (pid = fork()) { 164 case -1: 165 return (-1); 166 case 0: 167 /* 168 * child 169 */ 170 (void) close(master); 171 login_tty(slave); 172 return (0); 173 } 174 /* 175 * parent 176 */ 177 *amaster = master; 178 (void) close(slave); 179 return (pid); 180 } 181