stdio/FreeBSD/mktemp.c

   1 /*
   2  * Copyright (c) 1987, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)mktemp.c    8.1 (Berkeley) 6/4/93";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/stdio/mktemp.c,v 1.28 2003/02/16 17:29:10 nectar Exp $");
  39
  40 #include "namespace.h"
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <fcntl.h>
  44 #include <errno.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <ctype.h>
  49 #include <unistd.h>
  50 #include "un-namespace.h"
  51
  52 char *_mktemp(char *);
  53
  54 static int _gettemp(char *, int *, int, int);
  55
  56 static const unsigned char padchar[] =
  57 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  58
  59 int
  60 mkstemps(path, slen)
  61         char *path;
  62         int slen;
  63 {
  64         int fd;
  65
  66         return (_gettemp(path, &fd, 0, slen) ? fd : -1);
  67 }
  68
  69 int
  70 mkstemp(path)
  71         char *path;
  72 {
  73         int fd;
  74
  75         return (_gettemp(path, &fd, 0, 0) ? fd : -1);
  76 }
  77
  78 char *
  79 mkdtemp(path)
  80         char *path;
  81 {
  82         return (_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
  83 }
  84
  85 char *
  86 _mktemp(path)
  87         char *path;
  88 {
  89         return (_gettemp(path, (int *)NULL, 0, 0) ? path : (char *)NULL);
  90 }
  91
  92 __warn_references(mktemp,
  93     "warning: mktemp() possibly used unsafely; consider using mkstemp()");
  94
  95 char *
  96 mktemp(path)
  97         char *path;
  98 {
  99         return (_mktemp(path));
 100 }
 101
 102 static int
 103 _gettemp(path, doopen, domkdir, slen)
 104         char *path;
 105         int *doopen;
 106         int domkdir;
 107         int slen;
 108 {
 109         char *start, *trv, *suffp;
 110         char *pad;
 111         struct stat sbuf;
 112         int rval;
 113         uint32_t rand;
 114
 115         if (doopen != NULL && domkdir) {
 116                 errno = EINVAL;
 117                 return (0);
 118         }
 119
 120         for (trv = path; *trv != '\0'; ++trv)
 121                 ;
 122         trv -= slen;
 123         suffp = trv;
 124         --trv;
 125         if (trv < path) {
 126                 errno = EINVAL;
 127                 return (0);
 128         }
 129
 130         /* Fill space with random characters */
 131         while (trv >= path && *trv == 'X') {
 132                 rand = arc4random() % (sizeof(padchar) - 1);
 133                 *trv-- = padchar[rand];
 134         }
 135         start = trv + 1;
 136
 137         /*
 138          * check the target directory.
 139          */
 140         if (doopen != NULL || domkdir) {
 141                 for (; trv > path; --trv) {
 142                         if (*trv == '/') {
 143                                 *trv = '\0';
 144                                 rval = stat(path, &sbuf);
 145                                 *trv = '/';
 146                                 if (rval != 0)
 147                                         return (0);
 148                                 if (!S_ISDIR(sbuf.st_mode)) {
 149                                         errno = ENOTDIR;
 150                                         return (0);
 151                                 }
 152                                 break;
 153                         }
 154                 }
 155         }
 156
 157         for (;;) {
 158                 if (doopen) {
 159                         if ((*doopen =
 160                             _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
 161                                 return (1);
 162                         if (errno != EEXIST)
 163                                 return (0);
 164                 } else if (domkdir) {
 165                         if (mkdir(path, 0700) == 0)
 166                                 return (1);
 167                         if (errno != EEXIST)
 168                                 return (0);
 169                 } else if (lstat(path, &sbuf))
 170                         return (errno == ENOENT);
 171
 172                 /* If we have a collision, cycle through the space of filenames */
 173                 for (trv = start;;) {
 174                         if (*trv == '\0' || trv == suffp)
 175                                 return (0);
 176                         pad = strchr(padchar, *trv);
 177                         if (pad == NULL || *++pad == '\0')
 178                                 *trv++ = padchar[0];
 179                         else {
 180                                 *trv++ = *pad;
 181                                 break;
 182                         }
 183                 }
 184         }
 185         /*NOTREACHED*/
 186 }