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/* Copyright (C) 1991,92,93,94,95,96,97,98,99 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* March 11, 2002 Manuel Novoa III
*
* Modify code to remove dependency on libgcc long long arith support funcs.
*/
/* June 6, 2004 Erik Andersen
*
* Don't use brain damaged getpid() based randomness.
*/
/* April 15, 2005 Mike Frysinger
*
* Use brain damaged getpid() if real random fails.
*/
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include "tempname.h"
/* Return nonzero if DIR is an existent directory. */
static int direxists (const char *dir)
{
struct stat buf;
return stat(dir, &buf) == 0 && S_ISDIR (buf.st_mode);
}
/* Path search algorithm, for tmpnam, tmpfile, etc. If DIR is
non-null and exists, uses it; otherwise uses the first of $TMPDIR,
P_tmpdir, /tmp that exists. Copies into TMPL a template suitable
for use with mk[s]temp. Will fail (-1) if DIR is non-null and
doesn't exist, none of the searched dirs exists, or there's not
enough space in TMPL. */
int __path_search (char *tmpl, size_t tmpl_len, const char *dir,
const char *pfx, int try_tmpdir)
{
//const char *d;
size_t dlen, plen;
if (!pfx || !pfx[0])
{
pfx = "file";
plen = 4;
}
else
{
plen = strlen (pfx);
if (plen > 5)
plen = 5;
}
/* Disable support for $TMPDIR */
#if 0
if (try_tmpdir)
{
d = __secure_getenv ("TMPDIR");
if (d != NULL && direxists (d))
dir = d;
else if (dir != NULL && direxists (dir))
/* nothing */ ;
else
dir = NULL;
}
#endif
if (dir == NULL)
{
if (direxists (P_tmpdir))
dir = P_tmpdir;
else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
dir = "/tmp";
else
{
__set_errno (ENOENT);
return -1;
}
}
dlen = strlen (dir);
while (dlen > 1 && dir[dlen - 1] == '/')
dlen--; /* remove trailing slashes */
/* check we have room for "${dir}/${pfx}XXXXXX\0" */
if (tmpl_len < dlen + 1 + plen + 6 + 1)
{
__set_errno (EINVAL);
return -1;
}
sprintf (tmpl, "%.*s/%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
return 0;
}
/* These are the characters used in temporary filenames. */
static const char letters[] =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
static unsigned int fillrand(unsigned char *buf, unsigned int len)
{
int fd;
unsigned int result = -1;
fd = open("/dev/urandom", O_RDONLY);
if (fd < 0) {
fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
}
if (fd >= 0) {
result = read(fd, buf, len);
close(fd);
}
return result;
}
static void brain_damaged_fillrand(unsigned char *buf, unsigned int len)
{
int i, k;
struct timeval tv;
uint32_t high, low, rh;
static uint64_t value;
gettimeofday(&tv, NULL);
value += ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid();
low = value & UINT32_MAX;
high = value >> 32;
for (i = 0; i < len; ++i) {
rh = high % 62;
high /= 62;
#define L ((UINT32_MAX % 62 + 1) % 62)
k = (low % 62) + (L * rh);
#undef L
#define H ((UINT32_MAX / 62) + ((UINT32_MAX % 62 + 1) / 62))
low = (low / 62) + (H * rh) + (k / 62);
#undef H
k %= 62;
buf[i] = letters[k];
}
}
/* Generate a temporary file name based on TMPL. TMPL must match the
rules for mk[s]temp (i.e. end in "XXXXXX"). The name constructed
does not exist at the time of the call to __gen_tempname. TMPL is
overwritten with the result.
KIND may be one of:
__GT_NOCREATE: simply verify that the name does not exist
at the time of the call.
__GT_FILE: create the file using open(O_CREAT|O_EXCL)
and return a read-write fd. The file is mode 0600.
__GT_BIGFILE: same as __GT_FILE but use open64().
__GT_DIR: create a directory, which will be mode 0700.
*/
int __gen_tempname (char *tmpl, int kind)
{
char *XXXXXX;
unsigned int k;
int len, i, count, fd, save_errno = errno;
unsigned char randomness[6];
len = strlen (tmpl);
if (len < 6 || strcmp (&tmpl[len - 6], "XXXXXX"))
{
__set_errno (EINVAL);
return -1;
}
/* This is where the Xs start. */
XXXXXX = &tmpl[len - 6];
/* Get some random data. */
if (fillrand(randomness, sizeof(randomness)) != sizeof(randomness)) {
/* if random device nodes failed us, lets use the braindamaged ver */
brain_damaged_fillrand(randomness, sizeof(randomness));
}
for (i = 0 ; i < sizeof(randomness) ; i++) {
k = ((randomness[i]) % 62);
XXXXXX[i] = letters[k];
}
for (count = 0; count < TMP_MAX; ++count)
{
switch(kind) {
case __GT_NOCREATE:
{
struct stat st;
if (stat (tmpl, &st) < 0)
{
if (errno == ENOENT)
{
__set_errno (save_errno);
return 0;
}
else
/* Give up now. */
return -1;
}
else
continue;
}
case __GT_FILE:
fd = open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
break;
#if defined __UCLIBC_HAS_LFS__
case __GT_BIGFILE:
fd = open64 (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
break;
#endif
case __GT_DIR:
fd = mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
break;
default:
fd = -1;
assert (! "invalid KIND in __gen_tempname");
}
if (fd >= 0) {
__set_errno (save_errno);
return fd;
}
else if (errno != EEXIST)
/* Any other error will apply also to other names we might
try, and there are 2^32 or so of them, so give up now. */
return -1;
}
/* We got out of the loop because we ran out of combinations to try. */
__set_errno (EEXIST);
return -1;
}
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