freebsd-nq/lib/libutil/pty.c
2007-01-09 01:02:06 +00:00

169 lines
4.2 KiB
C

/*-
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)pty.c 8.3 (Berkeley) 5/16/94";
#endif
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <libutil.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
int __use_pts(void);
static int
new_openpty(int *amaster, int *aslave, char *name, struct termios *termp,
struct winsize *winp)
{
int master, slave;
master = posix_openpt(O_RDWR);
if (master == -1)
return (-1);
if (grantpt(master) == -1) {
close(master);
return (-1);
}
slave = open(ptsname(master), O_RDWR);
if (slave == -1) {
close(master);
return (-1);
}
if (unlockpt(master) == -1) {
close(master);
close(slave);
return (-1);
}
*amaster = master;
*aslave = slave;
if (name)
strcpy(name, ptsname(master));
if (termp)
tcsetattr(slave, TCSAFLUSH, termp);
if (winp)
ioctl(slave, TIOCSWINSZ, (char *)winp);
return (0);
}
int
openpty(int *amaster, int *aslave, char *name, struct termios *termp, struct winsize *winp)
{
char line[] = "/dev/ptyXX";
const char *cp1, *cp2;
int master, slave, ttygid;
struct group *gr;
if (__use_pts())
return (new_openpty(amaster, aslave, name, termp, winp));
if ((gr = getgrnam("tty")) != NULL)
ttygid = gr->gr_gid;
else
ttygid = -1;
for (cp1 = "pqrsPQRS"; *cp1; cp1++) {
line[8] = *cp1;
for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) {
line[5] = 'p';
line[9] = *cp2;
if ((master = open(line, O_RDWR, 0)) == -1) {
if (errno == ENOENT)
break; /* try the next pty group */
} else {
line[5] = 't';
(void) chown(line, getuid(), ttygid);
(void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP);
(void) revoke(line);
if ((slave = open(line, O_RDWR, 0)) != -1) {
*amaster = master;
*aslave = slave;
if (name)
strcpy(name, line);
if (termp)
(void) tcsetattr(slave,
TCSAFLUSH, termp);
if (winp)
(void) ioctl(slave, TIOCSWINSZ,
(char *)winp);
return (0);
}
(void) close(master);
}
}
}
errno = ENOENT; /* out of ptys */
return (-1);
}
int
forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp)
{
int master, slave, pid;
if (openpty(&master, &slave, name, termp, winp) == -1)
return (-1);
switch (pid = fork()) {
case -1:
return (-1);
case 0:
/*
* child
*/
(void) close(master);
login_tty(slave);
return (0);
}
/*
* parent
*/
*amaster = master;
(void) close(slave);
return (pid);
}