glibc/sysdeps/posix/tempname.c
Ulrich Drepper 46c3f8cdb4 Update.
2001-02-26  Paul Eggert  <eggert@twinsun.com>

	Modify mkstemp.c and tempname.c so that they can be used by
	GNU applications on non-glibc platforms.

	* misc/mkstemp.c (__GT_FILE): Define to zero if not defined.

	* sysdeps/posix/tempname.c: Include <config.h> if HAVE_CONFIG_H.
	Include <stddef.h>, <stdint.h>, <string.h> only if
	STDC_HEADERS || _LIBC.
	Include <fcntl.h> only if HAVE_FCNTL_H || _LIBC.
	Include <unistd.h> only if HAVE_UNISTD_H || _LIBC.
	Include <sys/time.h> only if HAVE_SYS_TIME_H || _LIBC.
	(__set_errno): Define this macro if <errno.h> doesn't.
	(P_tmpdir, TMP_MAX, __GT_FILE, __GT_BIGFILE, __GT_DIR, __GT_NOCREATE):
	Define these macros if <stdio.h> doesn't.
	(S_ISDIR, S_IRUSR, S_IWUSR, S_IXUSR):
	Define these macros if <sys/stat.h> doesn't.
	Ignore <sys/stat.h> S_ISDIR if STAT_MACROS_BROKEN.
	(stat64, __getpid, __gettimeofday, __mkdir, __open, __open64,
	lxstat64, __xstat64): Define if not _LIBC.
	(struct_stat64): New macro.
	(direxists, __gen_tempname): Use it, to avoid a
	portability problem with Solaris 8.
	(__secure_getenv): Define if ! (HAVE___SECURE_GETENV || _LIBC).
	(__gen_tempname): Invoke gettimeofday only if
	HAVE_GETTIMEOFDAY || _LIBC; otherwise, fall back on plain "time".
	Use portable macros like S_IRUSR | S_IWUSR rather than nonportable
	octal values like 0600.
2001-02-27 01:59:46 +00:00

298 lines
6.9 KiB
C

/* Copyright (C) 1991-1999, 2000, 2001 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. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <sys/types.h>
#include <assert.h>
#include <errno.h>
#ifndef __set_errno
# define __set_errno(Val) errno = (Val)
#endif
#include <stdio.h>
#ifndef P_tmpdir
# define P_tmpdir "/tmp"
#endif
#ifndef TMP_MAX
# define TMP_MAX 238328
#endif
#ifndef __GT_FILE
# define __GT_FILE 0
# define __GT_BIGFILE 1
# define __GT_DIR 2
# define __GT_NOCREATE 3
#endif
#if STDC_HEADERS || _LIBC
# include <stddef.h>
# include <stdlib.h>
# include <string.h>
#endif
#if HAVE_FCNTL_H || _LIBC
# include <fcntl.h>
#endif
#if HAVE_SYS_TIME_H || _LIBC
# include <sys/time.h>
#endif
#if HAVE_STDINT_H || _LIBC
# include <stdint.h>
#endif
#if HAVE_UNISTD_H || _LIBC
# include <unistd.h>
#endif
#include <sys/stat.h>
#if STAT_MACROS_BROKEN
# undef S_ISDIR
#endif
#if !defined S_ISDIR && defined S_IFDIR
# define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
#endif
#if !S_IRUSR && S_IREAD
# define S_IRUSR S_IREAD
#endif
#if !S_IRUSR
# define S_IRUSR 00400
#endif
#if !S_IWUSR && S_IWRITE
# define S_IWUSR S_IWRITE
#endif
#if !S_IWUSR
# define S_IWUSR 00200
#endif
#if !S_IXUSR && S_IEXEC
# define S_IXUSR S_IEXEC
#endif
#if !S_IXUSR
# define S_IXUSR 00100
#endif
#if _LIBC
# define struct_stat64 struct stat64
#else
# define struct_stat64 struct stat
# define __getpid getpid
# define __gettimeofday gettimeofday
# define __mkdir mkdir
# define __open open
# define __open64 open
# define __lxstat64(version, path, buf) lstat (path, buf)
# define __xstat64(version, path, buf) stat (path, buf)
#endif
#if ! (HAVE___SECURE_GETENV || _LIBC)
# define __secure_getenv getenv
#endif
/* Return nonzero if DIR is an existent directory. */
static int
direxists (const char *dir)
{
struct_stat64 buf;
return __xstat64 (_STAT_VER, 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 $TMPDIR,
P_tmpdir, /tmp that exists. Copies into TMPL a template suitable
for use with mk[s]temp. Will fail (-1) if DIR is non-null and
doesn't exist, none of the searched dirs exists, or there's not
enough space in TMPL. */
int
__path_search (char *tmpl, size_t tmpl_len, const char *dir, const char *pfx,
int try_tmpdir)
{
const char *d;
size_t dlen, plen;
if (!pfx || !pfx[0])
{
pfx = "file";
plen = 4;
}
else
{
plen = strlen (pfx);
if (plen > 5)
plen = 5;
}
if (try_tmpdir)
{
d = __secure_getenv ("TMPDIR");
if (d != NULL && direxists (d))
dir = d;
else if (dir != NULL && direxists (dir))
/* nothing */ ;
else
dir = NULL;
}
if (dir == NULL)
{
if (direxists (P_tmpdir))
dir = P_tmpdir;
else if (strcmp (P_tmpdir, "/tmp") != 0 && direxists ("/tmp"))
dir = "/tmp";
else
{
__set_errno (ENOENT);
return -1;
}
}
dlen = strlen (dir);
while (dlen > 1 && dir[dlen - 1] == '/')
dlen--; /* remove trailing slashes */
/* check we have room for "${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";
/* 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.
We use a clever algorithm to get hard-to-predict names. */
int
__gen_tempname (char *tmpl, int kind)
{
int len;
char *XXXXXX;
static uint64_t value;
uint64_t random_time_bits;
int count, fd = -1;
int save_errno = errno;
struct_stat64 st;
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 more or less random data. */
#if HAVE_GETTIMEOFDAY || _LIBC
{
struct timeval tv;
__gettimeofday (&tv, NULL);
random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
}
#else
random_time_bits = time (NULL);
#endif
value += random_time_bits ^ __getpid ();
for (count = 0; count < TMP_MAX; value += 7777, ++count)
{
uint64_t v = value;
/* Fill in the random bits. */
XXXXXX[0] = letters[v % 62];
v /= 62;
XXXXXX[1] = letters[v % 62];
v /= 62;
XXXXXX[2] = letters[v % 62];
v /= 62;
XXXXXX[3] = letters[v % 62];
v /= 62;
XXXXXX[4] = letters[v % 62];
v /= 62;
XXXXXX[5] = letters[v % 62];
switch (kind)
{
case __GT_FILE:
fd = __open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
break;
case __GT_BIGFILE:
fd = __open64 (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
break;
case __GT_DIR:
fd = __mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);
break;
case __GT_NOCREATE:
/* This case is backward from the other three. __gen_tempname
succeeds if __xstat fails because the name does not exist.
Note the continue to bypass the common logic at the bottom
of the loop. */
if (__lxstat64 (_STAT_VER, tmpl, &st) < 0)
{
if (errno == ENOENT)
{
__set_errno (save_errno);
return 0;
}
else
/* Give up now. */
return -1;
}
continue;
default:
assert (! "invalid KIND in __gen_tempname");
}
if (fd >= 0)
{
__set_errno (save_errno);
return fd;
}
else if (errno != EEXIST)
return -1;
}
/* We got out of the loop because we ran out of combinations to try. */
__set_errno (EEXIST);
return -1;
}