From 696f4a8042e11f6caf479f729b09dcae2700e541 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sat, 1 Sep 2007 11:33:00 +0200 Subject: Copy from gnulib the parts of tempname that we'll modify. * gl/lib/tempname.c: Copy from gnulib. * gl/lib/tempname.h: Likewise. * gl/modules/tempname: Likewise. Allow GPLv2 on temporarily(?)-imported file from gnulib/libc. * .x-sc_GPL_version: New file. * Makefile.am (EXTRA_DIST): Add .x-sc_GPL_version --- .x-sc_GPL_version | 2 + ChangeLog | 10 ++ gl/lib/tempname.c | 315 ++++++++++++++++++++++++++++++++++++++++++++++++++++ gl/lib/tempname.h | 40 +++++++ gl/modules/tempname | 28 +++++ 5 files changed, 395 insertions(+) create mode 100644 gl/lib/tempname.c create mode 100644 gl/lib/tempname.h create mode 100644 gl/modules/tempname diff --git a/.x-sc_GPL_version b/.x-sc_GPL_version index d496afaad..19bdfd9e9 100644 --- a/.x-sc_GPL_version +++ b/.x-sc_GPL_version @@ -1 +1,3 @@ ^build-aux/check\.mk$ +^gl/lib/tempname\.c$ +^gl/lib/tempname\.h$ diff --git a/ChangeLog b/ChangeLog index 5d6d980b4..fb2ce1695 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2007-10-07 Jim Meyering + + Copy from gnulib the parts of tempname that we'll modify. + * gl/lib/tempname.c: Copy from gnulib. + * gl/lib/tempname.h: Likewise. + * gl/modules/tempname: Likewise. + Allow GPLv2 on temporarily(?)-imported file from gnulib/libc. + * .x-sc_GPL_version: New file. + * Makefile.am (EXTRA_DIST): Add .x-sc_GPL_version + 2007-10-07 Jim Meyering Avoid a pseudo-leak in sort. diff --git a/gl/lib/tempname.c b/gl/lib/tempname.c new file mode 100644 index 000000000..e213600e3 --- /dev/null +++ b/gl/lib/tempname.c @@ -0,0 +1,315 @@ +/* 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 2, 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, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* Extracted from glibc sysdeps/posix/tempname.c. See also tmpdir.c. */ + +#if !_LIBC +# include +# include "tempname.h" +#endif + +#include +#include + +#include +#ifndef __set_errno +# define __set_errno(Val) errno = (Val) +#endif + +#include +#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 +#include +#include + +#include +#include +#include +#include + +#include + +#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 +# 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; +} diff --git a/gl/lib/tempname.h b/gl/lib/tempname.h new file mode 100644 index 000000000..c51fa6942 --- /dev/null +++ b/gl/lib/tempname.h @@ -0,0 +1,40 @@ +/* Create a temporary file or directory. + + Copyright (C) 2006 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 2, 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, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* header written by Eric Blake */ + +/* In gnulib, always prefer large files. GT_FILE maps to + __GT_BIGFILE, not __GT_FILE, for a reason. */ +#define GT_FILE 1 +#define GT_DIR 2 +#define GT_NOCREATE 3 + +/* 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 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 kind); diff --git a/gl/modules/tempname b/gl/modules/tempname new file mode 100644 index 000000000..af689de6f --- /dev/null +++ b/gl/modules/tempname @@ -0,0 +1,28 @@ +Description: +gen_tempname() function: create a private temporary file or directory. + +Files: +lib/tempname.c +lib/tempname.h +m4/tempname.m4 + +Depends-on: +extensions +gettimeofday +stdint +sys_stat +sys_time + +configure.ac: +gl_FUNC_GEN_TEMPNAME + +Makefile.am: + +Include: +"tempname.h" + +License: +LGPL + +Maintainer: +Eric Blake and Jim Meyering -- cgit v1.2.3-54-g00ecf