Commit e0fdb694 authored by Paul Eggert's avatar Paul Eggert

Fix some minor races in hosts lacking mkostemp.

Gnulib's emulation of mkostemp doesn't have races that Emacs's does.
* configure.ac (mkostemp): Remove check for this function;
gnulib does the check now.
(mkstemp): Remove check for this no-longer-used function.
* lib/mkostemp.c, lib/secure_getenv.c, lib/tempname.c, lib/tempname.h:
* m4/mkostemp.m4, m4/secure_getenv.m4, m4/tempname.m4:
New files, copied from Gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* admin/merge-gnulib (GNULIB_MODULES): Add mkostemp.
* lib-src/movemail.c (main):
* lib-src/update-game-score.c (write_scores):
Use mkostemp (which now works on all platforms, due to changes
in the portability layer) rather than mktemp (which has a race)
or mkstemp (which we no longer bother with).
* src/callproc.c (create_temp_file):
* src/filelock.c (create_lock_file):
Assume mkostemp, since it's now provided by Gnulib.

Fixes: debbugs:15015
parent 484ab239
2013-08-04 Paul Eggert <eggert@cs.ucla.edu>
Fix some minor races in hosts lacking mkostemp (Bug#15015).
Gnulib's emulation of mkostemp doesn't have races that Emacs's does.
* configure.ac (mkostemp): Remove check for this function;
gnulib does the check now.
(mkstemp): Remove check for this no-longer-used function.
* lib/mkostemp.c, lib/secure_getenv.c, lib/tempname.c, lib/tempname.h:
* m4/mkostemp.m4, m4/secure_getenv.m4, m4/tempname.m4:
New files, copied from Gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
2013-07-29 Michael Albinus <michael.albinus@gmx.de>
* INSTALL (DETAILED BUILDING AND INSTALLATION): Add
......
2013-08-04 Paul Eggert <eggert@cs.ucla.edu>
Fix some minor races in hosts lacking mkostemp (Bug#15015).
* merge-gnulib (GNULIB_MODULES): Add mkostemp.
2013-07-12 Glenn Morris <rgm@gnu.org>
* admin.el (manual-style-string): Use non-abbreviated url.
......
......@@ -32,7 +32,7 @@ GNULIB_MODULES='
fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync
getloadavg getopt-gnu gettime gettimeofday
intprops largefile lstat
manywarnings memrchr mktime
manywarnings memrchr mkostemp mktime
pipe2 pselect pthread_sigmask putenv qacl readlink readlinkat
sig2str socklen stat-time stdalign stdarg stdbool stdio
strftime strtoimax strtoumax symlink sys_stat
......
......@@ -3277,7 +3277,7 @@ select getpagesize setlocale \
getrlimit setrlimit shutdown getaddrinfo \
strsignal setitimer \
sendto recvfrom getsockname getpeername getifaddrs freeifaddrs \
gai_strerror mkostemp mkstemp getline getdelim sync \
gai_strerror getline getdelim sync \
difftime posix_memalign \
getpwent endpwent getgrent endgrent \
touchlock \
......
2013-08-04 Paul Eggert <eggert@cs.ucla.edu>
Fix some minor races in hosts lacking mkostemp (Bug#15015).
* movemail.c (main):
* update-game-score.c (write_scores):
Use mkostemp (which now works on all platforms, due to changes
in the portability layer) rather than mktemp (which has a race)
or mkstemp (which we no longer bother with).
2013-07-10 Paul Eggert <eggert@cs.ucla.edu>
Port to C89.
......
......@@ -304,24 +304,13 @@ main (int argc, char **argv)
memcpy (tempname, inname, inname_dirlen);
strcpy (tempname + inname_dirlen, "EXXXXXX");
#ifdef HAVE_MKSTEMP
desc = mkstemp (tempname);
#else
mktemp (tempname);
if (!*tempname)
desc = -1;
else
{
unlink (tempname);
desc = open (tempname, O_WRONLY | O_CREAT | O_EXCL, 0600);
}
#endif
desc = mkostemp (tempname, 0);
if (desc < 0)
{
int mkstemp_errno = errno;
int mkostemp_errno = errno;
error ("error while creating what would become the lock file",
0, 0);
errno = mkstemp_errno;
errno = mkostemp_errno;
pfatal_with_name (tempname);
}
close (desc);
......
......@@ -383,6 +383,7 @@ sort_scores (struct score_entry *scores, int count, int reverse)
static int
write_scores (const char *filename, const struct score_entry *scores, int count)
{
int fd;
FILE *f;
int i;
char *tempfile = malloc (strlen (filename) + strlen (".tempXXXXXX") + 1);
......@@ -390,12 +391,11 @@ write_scores (const char *filename, const struct score_entry *scores, int count)
return -1;
strcpy (tempfile, filename);
strcat (tempfile, ".tempXXXXXX");
#ifdef HAVE_MKSTEMP
if (mkstemp (tempfile) < 0
#else
if (mktemp (tempfile) != tempfile
#endif
|| !(f = fopen (tempfile, "w")))
fd = mkostemp (tempfile, 0);
if (fd < 0)
return -1;
f = fdopen (fd, "w");
if (! f)
return -1;
for (i = 0; i < count; i++)
if (fprintf (f, "%ld %s %s\n", scores[i].score, scores[i].username,
......
......@@ -21,7 +21,7 @@
# the same distribution terms as the rest of that program.
#
# Generated by gnulib-tool.
# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync getloadavg getopt-gnu gettime gettimeofday intprops largefile lstat manywarnings memrchr mktime pipe2 pselect pthread_sigmask putenv qacl readlink readlinkat sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings
# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode fstatat fsync getloadavg getopt-gnu gettime gettimeofday intprops largefile lstat manywarnings memrchr mkostemp mktime pipe2 pselect pthread_sigmask putenv qacl readlink readlinkat sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings
MOSTLYCLEANFILES += core *.stackdump
......@@ -560,6 +560,15 @@ EXTRA_libgnu_a_SOURCES += memrchr.c
## end gnulib module memrchr
## begin gnulib module mkostemp
EXTRA_DIST += mkostemp.c
EXTRA_libgnu_a_SOURCES += mkostemp.c
## end gnulib module mkostemp
## begin gnulib module mktime
......@@ -657,6 +666,17 @@ EXTRA_DIST += root-uid.h
## end gnulib module root-uid
## begin gnulib module secure_getenv
if gl_GNULIB_ENABLED_secure_getenv
endif
EXTRA_DIST += secure_getenv.c
EXTRA_libgnu_a_SOURCES += secure_getenv.c
## end gnulib module secure_getenv
## begin gnulib module sig2str
......@@ -1480,6 +1500,16 @@ EXTRA_DIST += sys_time.in.h
## end gnulib module sys_time
## begin gnulib module tempname
if gl_GNULIB_ENABLED_tempname
libgnu_a_SOURCES += tempname.c
endif
EXTRA_DIST += tempname.h
## end gnulib module tempname
## begin gnulib module time
BUILT_SOURCES += time.h
......
/* Copyright (C) 1998-1999, 2001, 2005-2007, 2009-2013 Free Software
Foundation, Inc.
This file is derived from the one in the GNU C Library.
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/>. */
#if !_LIBC
# include <config.h>
#endif
#include <stdlib.h>
#if !_LIBC
# include "tempname.h"
# define __gen_tempname gen_tempname
# ifndef __GTFILE
# define __GT_FILE GT_FILE
# endif
#endif
#include <stdio.h>
#ifndef __GT_FILE
# define __GT_FILE 0
#endif
/* Generate a unique temporary file name from XTEMPLATE.
The last six characters of XTEMPLATE must be "XXXXXX";
they are replaced with a string that makes the file name unique.
Then open the file and return a fd. */
int
mkostemp (char *xtemplate, int flags)
{
return __gen_tempname (xtemplate, 0, flags, __GT_FILE);
}
/* Look up an environment variable more securely.
Copyright 2013 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/>. */
#include <config.h>
#include <stdlib.h>
#if !HAVE___SECURE_GETENV
# if HAVE_ISSETUGID
# include <unistd.h>
# else
# undef issetugid
# define issetugid() 1
# endif
#endif
char *
secure_getenv (char const *name)
{
#if HAVE___SECURE_GETENV
return __secure_getenv (name);
#else
if (issetugid ())
return 0;
return getenv (name);
#endif
}
/* tempname.c - generate the name of a temporary file.
Copyright (C) 1991-2003, 2005-2007, 2009-2013 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_DIR 1
# define __GT_NOCREATE 2
#endif
#if !_LIBC && (GT_FILE != __GT_FILE || GT_DIR != __GT_DIR \
|| GT_NOCREATE != __GT_NOCREATE)
# error report this to bug-gnulib@gnu.org
#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
#else
# define struct_stat64 struct stat
# define __gen_tempname gen_tempname
# define __getpid getpid
# define __gettimeofday gettimeofday
# define __mkdir mkdir
# define __open open
# define __lxstat64(version, file, buf) lstat (file, buf)
# define __secure_getenv secure_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", possibly with a suffix).
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_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 suffixlen, int flags, 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 of 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 + suffixlen || memcmp (&tmpl[len - 6 - suffixlen], "XXXXXX", 6))
{
__set_errno (EINVAL);
return -1;
}
/* This is where the Xs start. */
XXXXXX = &tmpl[len - 6 - suffixlen];
/* 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 = __open (tmpl,
(flags & ~O_ACCMODE)
| 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");
abort ();
}
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;
}
/* Create a temporary file or directory.
Copyright (C) 2006, 2009-2013 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/>. */
/* header written by Eric Blake */
#ifndef GL_TEMPNAME_H
# define GL_TEMPNAME_H
# include <stdio.h>
# ifdef __GT_FILE
# define GT_FILE __GT_FILE
# define GT_DIR __GT_DIR
# define GT_NOCREATE __GT_NOCREATE
# else
# define GT_FILE 0
# define GT_DIR 1
# define GT_NOCREATE 2
# endif
/* Generate a temporary file name based on TMPL. TMPL must match the
rules for mk[s]temp (i.e. end in "XXXXXX", possibly with a suffix).
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 a large file using open(O_CREAT|O_EXCL)
and return a read-write fd. The file is mode 0600.
GT_DIR: create a directory, which will be mode 0700.
We use a clever algorithm to get hard-to-predict names. */
extern int gen_tempname (char *tmpl, int suffixlen, int flags, int kind);
#endif /* GL_TEMPNAME_H */
<
......@@ -89,6 +89,7 @@ AC_DEFUN([gl_EARLY],
# Code from module lstat:
# Code from module manywarnings:
# Code from module memrchr:
# Code from module mkostemp:
# Code from module mktime:
# Code from module multiarch:
# Code from module nocrash:
......@@ -102,6 +103,7 @@ AC_DEFUN([gl_EARLY],
# Code from module readlink:
# Code from module readlinkat:
# Code from module root-uid:
# Code from module secure_getenv:
# Code from module sig2str:
# Code from module signal-h:
# Code from module snippet/_Noreturn:
......@@ -134,6 +136,7 @@ AC_DEFUN([gl_EARLY],
# Code from module sys_select:
# Code from module sys_stat:
# Code from module sys_time:
# Code from module tempname:
# Code from module time:
# Code from module time_r:
# Code from module timer-time:
......@@ -274,6 +277,13 @@ AC_DEFUN([gl_INIT],
gl_PREREQ_MEMRCHR
fi
gl_STRING_MODULE_INDICATOR([memrchr])
gl_FUNC_MKOSTEMP
if test $HAVE_MKOSTEMP = 0; then
AC_LIBOBJ([mkostemp])
gl_PREREQ_MKOSTEMP
fi
gl_MODULE_INDICATOR([mkostemp])
gl_STDLIB_MODULE_INDICATOR([mkostemp])
gl_FUNC_MKTIME
if test $REPLACE_MKTIME = 1; then
AC_LIBOBJ([mktime])
......@@ -381,9 +391,11 @@ AC_DEFUN([gl_INIT],
gl_gnulib_enabled_03e0aaad4cb89ca757653bd367a6ccb7=false
gl_gnulib_enabled_pathmax=false
gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=false
gl_gnulib_enabled_secure_getenv=false
gl_gnulib_enabled_stat=false
gl_gnulib_enabled_strtoll=false
gl_gnulib_enabled_strtoull=false
gl_gnulib_enabled_tempname=false
gl_gnulib_enabled_682e609604ccaac6be382e4ee3a4eaec=false
func_gl_gnulib_m4code_260941c0e5dc67ec9e87d1fb321c300b ()
{
......@@ -485,6 +497,18 @@ AC_DEFUN([gl_INIT],
gl_gnulib_enabled_6099e9737f757db36c47fa9d9f02e88c=true
fi
}
func_gl_gnulib_m4code_secure_getenv ()
{