open.c revision 8fd04b8338ed5093ec2d1e668fa620b7de44c177
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#include "lint.h"
#include <sys/mkdev.h>
#include <limits.h>
#include <stdarg.h>
#include <unistd.h>
#include <strings.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <sys/stropts.h>
#include <sys/stream.h>
#include <sys/ptms.h>
#include <sys/syscall.h>
#include "libc.h"
static int xpg4_fixup(int fd);
static void push_module(int fd);
static int isptsfd(int fd);
static void itoa(int i, char *ptr);
int
__openat(int dfd, const char *path, int oflag, mode_t mode)
{
int fd = syscall(SYS_openat, dfd, path, oflag, mode);
return (xpg4_fixup(fd));
}
int
__open(const char *path, int oflag, mode_t mode)
{
#if defined(_RETAIN_OLD_SYSCALLS)
int fd = syscall(SYS_open, path, oflag, mode);
return (xpg4_fixup(fd));
#else
return (__openat(AT_FDCWD, path, oflag, mode));
#endif
}
#if !defined(_LP64)
int
__openat64(int dfd, const char *path, int oflag, mode_t mode)
{
int fd = syscall(SYS_openat64, dfd, path, oflag, mode);
return (xpg4_fixup(fd));
}
int
__open64(const char *path, int oflag, mode_t mode)
{
#if defined(_RETAIN_OLD_SYSCALLS)
int fd = syscall(SYS_open64, path, oflag, mode);
return (xpg4_fixup(fd));
#else
return (__openat64(AT_FDCWD, path, oflag, mode));
#endif
}
#endif /* !_LP64 */
/*
* XPG4v2 requires that open of a slave pseudo terminal device
* provides the process with an interface that is identical to
* the terminal interface. For a more detailed discussion,
* see bugid 4025044.
*/
static int
xpg4_fixup(int fd)
{
if (libc__xpg4 != 0 && fd >= 0 && isptsfd(fd))
push_module(fd);
return (fd);
}
/*
* Check if the file matches an entry in the /dev/pts directory.
* Be careful to preserve errno.
*/
static int
isptsfd(int fd)
{
char buf[TTYNAME_MAX];
char *str1 = buf;
const char *str2 = "/dev/pts/";
struct stat64 fsb, stb;
int oerrno = errno;
int rval = 0;
if (fstat64(fd, &fsb) == 0 && S_ISCHR(fsb.st_mode)) {
/*
* Do this without strcpy() or strlen(),
* to avoid invoking the dynamic linker.
*/
while (*str2 != '\0')
*str1++ = *str2++;
/*
* Inline version of minor(dev), to avoid the dynamic linker.
*/
itoa(fsb.st_rdev & MAXMIN, str1);
if (stat64(buf, &stb) == 0)
rval = (stb.st_rdev == fsb.st_rdev);
}
errno = oerrno;
return (rval);
}
/*
* Converts a number to a string (null terminated).
*/
static void
itoa(int i, char *ptr)
{
int dig = 0;
int tempi;
tempi = i;
do {
dig++;
tempi /= 10;
} while (tempi);
ptr += dig;
*ptr = '\0';
while (--dig >= 0) {
*(--ptr) = i % 10 + '0';
i /= 10;
}
}
/*
* Push modules to provide tty semantics
*/
static void
push_module(int fd)
{
struct strioctl istr;
int oerrno = errno;
istr.ic_cmd = PTSSTTY;
istr.ic_len = 0;
istr.ic_timout = 0;
istr.ic_dp = NULL;
if (ioctl(fd, I_STR, &istr) != -1) {
(void) ioctl(fd, __I_PUSH_NOCTTY, "ptem");
(void) ioctl(fd, __I_PUSH_NOCTTY, "ldterm");
(void) ioctl(fd, __I_PUSH_NOCTTY, "ttcompat");
istr.ic_cmd = PTSSTTY;
istr.ic_len = 0;
istr.ic_timout = 0;
istr.ic_dp = NULL;
(void) ioctl(fd, I_STR, &istr);
}
errno = oerrno;
}