newlib-cygwin/winsup/cygwin/mktemp.cc

169 lines
4.0 KiB
C++

/* mktemp.cc: mktemp functions
This file is adapted for Cygwin from FreeBSD.
See the copyright at the bottom of this file. */
#include "winsup.h"
#include "cygerrno.h"
#include <fcntl.h>
#include <unistd.h>
static int _gettemp(char *, int *, int);
static uint32_t arc4random ();
static const char padchar[] =
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
extern "C" int
mkstemp(char *path)
{
int fd;
return _gettemp(path, &fd, 0) ? fd : -1;
}
extern "C" char *
mkdtemp(char *path)
{
return _gettemp(path, NULL, 1) ? path : NULL;
}
extern "C" char *
mktemp(char *path)
{
return _gettemp(path, NULL, 0) ? path : (char *) NULL;
}
static int
_gettemp(char *path, int *doopen, int domkdir)
{
char *start, *trv, *suffp;
char *pad;
if (doopen && domkdir)
{
set_errno (EINVAL);
return 0;
}
suffp = trv = strchr (path, '\0');
if (--trv < path)
{
set_errno (EINVAL);
return 0;
}
/* Fill space with random characters */
while (trv >= path && *trv == 'X')
{
uint32_t rand = arc4random () % (sizeof (padchar) - 1);
*trv-- = padchar[rand];
}
start = trv + 1;
/*
* check the target directory.
*/
struct __stat64 sbuf;
if (doopen != NULL || domkdir)
{
for (; trv > path; trv--)
{
if (*trv == '/')
{
*trv = '\0';
int rval = stat64 (path, &sbuf);
*trv = '/';
if (rval != 0)
return 0;
if (!S_ISDIR (sbuf.st_mode))
{
set_errno (ENOTDIR);
return 0;
}
break;
}
}
}
for (;;)
{
if (doopen)
{
if ((*doopen = open (path, O_CREAT | O_EXCL | O_RDWR | O_BINARY,
S_IRUSR | S_IWUSR)) >= 0)
return 1;
if (errno != EEXIST)
return 0;
}
else if (domkdir)
{
if (mkdir (path, 0700) == 0)
return 1;
if (errno != EEXIST)
return 0;
}
else if (lstat64 (path, &sbuf))
return errno == ENOENT;
/* If we have a collision, cycle through the space of filenames */
for (trv = start;;)
{
if (*trv == '\0' || trv == suffp)
return 0;
pad = strchr (padchar, *trv);
if (pad == NULL || *++pad == '\0')
*trv++ = padchar[0];
else
{
*trv++ = *pad;
break;
}
}
}
/*NOTREACHED*/
}
static uint32_t
arc4random ()
{
union
{
uint32_t rand;
char buf[sizeof (int) / 8];
} r;
int fd = open ("/dev/urandom", O_RDONLY);
read (fd, r.buf, 4);
close (fd);
return r.rand;
}
/*
* Copyright (c) 1987, 1993
* 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.
*/