+++ /dev/null
-/* tempname.c - generate the name of a temporary file.
-
- Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- 2000, 2001, 2002, 2003, 2005, 2006, 2007 Free Software Foundation,
- Inc.
-
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
-
- This program 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 General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
-
-/* Extracted from glibc sysdeps/posix/tempname.c. See also tmpdir.c. */
-
-#if !_LIBC
-# include <config.h>
-# include "tempname.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
-
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <fcntl.h>
-#include <sys/time.h>
-#include <stdint.h>
-#include <unistd.h>
-
-#include <sys/stat.h>
-
-#if _LIBC
-# define struct_stat64 struct stat64
-# define small_open __open
-# define large_open __open64
-#else
-# define struct_stat64 struct stat
-# define small_open open
-# define large_open open
-# define __gen_tempname gen_tempname
-# define __getpid getpid
-# define __gettimeofday gettimeofday
-# define __mkdir mkdir
-# define __lxstat64(version, file, buf) lstat (file, buf)
-# define __xstat64(version, file, buf) stat (file, 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
-
-#if _LIBC
-/* 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;
-}
-#endif /* _LIBC */
-
-/* These are the characters used in temporary file names. */
-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. */
-#define 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. */
-#if ATTEMPTS_MIN < TMP_MAX
- unsigned int attempts = TMP_MAX;
-#else
- unsigned int attempts = ATTEMPTS_MIN;
-#endif
-
- 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
- {
- struct timeval tv;
- __gettimeofday (&tv, NULL);
- random_time_bits = ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec;
- }
-#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 = small_open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
- break;
-
- case __GT_BIGFILE:
- fd = large_open (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;
-}
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