Subversion Repositories or1k

/* Copyright (C) 1991,92,93,94,95,96,97,98,99 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.  */

/* March 11, 2002       Manuel Novoa III

 *

 * Modify code to remove dependency on libgcc long long arith support funcs.

 */

#include <stddef.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#include <assert.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/time.h>

#include "tempname.h"

/* Return nonzero if DIR is an existent directory.  */

static int direxists (const char *dir)

{

    struct stat buf;

    return stat(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 0

    if (try_tmpdir)

    {

        d = __secure_getenv ("TMPDIR");

        if (d != NULL && direxists (d))

            dir = d;

        else if (dir != NULL && direxists (dir))

            /* nothing */ ;

        else

            dir = NULL;

    }

#endif  

    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)

{

    char *XXXXXX;

    struct timeval tv;

    uint32_t high, low, rh;

    unsigned int k;

    int len, i, count, fd, save_errno = errno;

    static uint64_t value; /* Do not initialize this,

                              or lock it for multi-threaded

                              apps -- the messier the better */

    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.  */

    gettimeofday (&tv, NULL);

    value += ((uint64_t) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();

    for (count = 0; count < TMP_MAX; value += 7777, ++count)

    {

        low = value & UINT32_MAX;

        high = value >> 32;

        for (i = 0 ; i < 6 ; i++) {

            rh = high % 62;

            high /= 62;

#define L ((UINT32_MAX % 62 + 1) % 62)

            k = (low % 62) + (L * rh);

#undef L

#define H ((UINT32_MAX / 62) + ((UINT32_MAX % 62 + 1) / 62))

            low = (low / 62) + (H * rh) + (k / 62);

#undef H

            k %= 62;

            XXXXXX[i] = letters[k];

        }

        switch(kind) {

            case __GT_NOCREATE:

                {

                    struct stat st;

                    if (stat (tmpl, &st) < 0)

                    {

                        if (errno == ENOENT)

                        {

                            __set_errno (save_errno);

                            return 0;

                        }

                        else

                            /* Give up now. */

                            return -1;

                    }

                    else

                        continue;

                }

            case __GT_FILE:

                fd = open (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);

                break;

#if defined __UCLIBC_HAS_LFS__

            case __GT_BIGFILE:

                fd = open64 (tmpl, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);

                break;

#endif

            case __GT_DIR:

                fd = mkdir (tmpl, S_IRUSR | S_IWUSR | S_IXUSR);

                break;

            default:

                fd = -1;

                assert (! "invalid KIND in __gen_tempname");

        }

        if (fd >= 0) {

            __set_errno (save_errno);

            return fd;

        }

        else if (errno != EEXIST)

            /* Any other error will apply also to other names we might

               try, and there are 2^32 or so of them, so give up now. */

            return -1;

    }

    /* We got out of the loop because we ran out of combinations to try.  */

    __set_errno (EEXIST);

    return -1;

}