mirror of
https://github.com/coreutils/coreutils.git
synced 2024-11-26 03:13:42 +08:00
344 lines
8.7 KiB
C
344 lines
8.7 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 Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; 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 <string.h>
|
|
#endif
|
|
|
|
#include <stdlib.h>
|
|
|
|
#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
|
|
|
|
#ifdef _LIBC
|
|
# include <hp-timing.h>
|
|
# if HP_TIMING_AVAIL
|
|
# define RANDOM_BITS(Var) \
|
|
if (__builtin_expect (value == UINT64_C (0), 0)) \
|
|
{ \
|
|
/* If this is the first time this function is used initialize \
|
|
the variable we accumulate the value in to some somewhat \
|
|
random value. If we'd not do this programs at startup time \
|
|
might have a reduced set of possible names, at least on slow \
|
|
machines. */ \
|
|
struct timeval tv; \
|
|
__gettimeofday (&tv, NULL); \
|
|
value = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec; \
|
|
} \
|
|
HP_TIMING_NOW (Var)
|
|
# endif
|
|
#endif
|
|
|
|
/* Use the widest available unsigned type if uint64_t is not
|
|
available. The algorithm below extracts a number less than 62**6
|
|
(approximately 2**35.725) from uint64_t, so ancient hosts where
|
|
uintmax_t is only 32 bits lose about 3.725 bits of randomness,
|
|
which is better than not having mkstemp at all. */
|
|
#if !defined UINT64_MAX && !defined uint64_t
|
|
# define uint64_t uintmax_t
|
|
#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;
|
|
unsigned int count;
|
|
int fd = -1;
|
|
int save_errno = errno;
|
|
struct_stat64 st;
|
|
|
|
/* A lower bound on the number of temporary files to attempt to
|
|
generate. The maximum total number of temporary file names that
|
|
can exist for a given template is 62**6. It should never be
|
|
necessary to try all these combinations. Instead if a reasonable
|
|
number of names is tried (we define reasonable as 62**3) fail to
|
|
give the system administrator the chance to remove the problems. */
|
|
unsigned int attempts_min = 62 * 62 * 62;
|
|
|
|
/* The number of times to attempt to generate a temporary file. To
|
|
conform to POSIX, this must be no smaller than TMP_MAX. */
|
|
unsigned int attempts = attempts_min < TMP_MAX ? TMP_MAX : attempts_min;
|
|
|
|
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. */
|
|
#ifdef RANDOM_BITS
|
|
RANDOM_BITS (random_time_bits);
|
|
#else
|
|
# 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
|
|
#endif
|
|
value += random_time_bits ^ __getpid ();
|
|
|
|
for (count = 0; count < attempts; 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;
|
|
}
|