openbsd-compat/mktemp.c

   1 /* OPENBSD ORIGINAL: lib/libc/stdio/mktemp.c */
   2
   3 /* THIS FILE HAS BEEN MODIFIED FROM THE ORIGINAL OPENBSD SOURCE */
   4 /* Changes: Removed mktemp */
   5
   6 /*
   7  * Copyright (c) 1987, 1993
   8  *      The Regents of the University of California.  All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include "includes.h"
  36
  37 #if !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP)
  38
  39 #if defined(LIBC_SCCS) && !defined(lint)
  40 static char rcsid[] = "$OpenBSD: mktemp.c,v 1.17 2003/06/02 20:18:37 millert Exp $";
  41 #endif /* LIBC_SCCS and not lint */
  42
  43 static int _gettemp(char *, int *, int, int);
  44
  45 int
  46 mkstemps(path, slen)
  47         char *path;
  48         int slen;
  49 {
  50         int fd;
  51
  52         return (_gettemp(path, &fd, 0, slen) ? fd : -1);
  53 }
  54
  55 int
  56 mkstemp(path)
  57         char *path;
  58 {
  59         int fd;
  60
  61         return (_gettemp(path, &fd, 0, 0) ? fd : -1);
  62 }
  63
  64 char *
  65 mkdtemp(path)
  66         char *path;
  67 {
  68         return(_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
  69 }
  70
  71 static int
  72 _gettemp(path, doopen, domkdir, slen)
  73         char *path;
  74         register int *doopen;
  75         int domkdir;
  76         int slen;
  77 {
  78         register char *start, *trv, *suffp;
  79         struct stat sbuf;
  80         int rval;
  81         pid_t pid;
  82
  83         if (doopen && domkdir) {
  84                 errno = EINVAL;
  85                 return(0);
  86         }
  87
  88         for (trv = path; *trv; ++trv)
  89                 ;
  90         trv -= slen;
  91         suffp = trv;
  92         --trv;
  93         if (trv < path) {
  94                 errno = EINVAL;
  95                 return (0);
  96         }
  97         pid = getpid();
  98         while (trv >= path && *trv == 'X' && pid != 0) {
  99                 *trv-- = (pid % 10) + '0';
 100                 pid /= 10;
 101         }
 102         while (trv >= path && *trv == 'X') {
 103                 char c;
 104
 105                 pid = (arc4random() & 0xffff) % (26+26);
 106                 if (pid < 26)
 107                         c = pid + 'A';
 108                 else
 109                         c = (pid - 26) + 'a';
 110                 *trv-- = c;
 111         }
 112         start = trv + 1;
 113
 114         /*
 115          * check the target directory; if you have six X's and it
 116          * doesn't exist this runs for a *very* long time.
 117          */
 118         if (doopen || domkdir) {
 119                 for (;; --trv) {
 120                         if (trv <= path)
 121                                 break;
 122                         if (*trv == '/') {
 123                                 *trv = '\0';
 124                                 rval = stat(path, &sbuf);
 125                                 *trv = '/';
 126                                 if (rval != 0)
 127                                         return(0);
 128                                 if (!S_ISDIR(sbuf.st_mode)) {
 129                                         errno = ENOTDIR;
 130                                         return(0);
 131                                 }
 132                                 break;
 133                         }
 134                 }
 135         }
 136
 137         for (;;) {
 138                 if (doopen) {
 139                         if ((*doopen =
 140                             open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
 141                                 return(1);
 142                         if (errno != EEXIST)
 143                                 return(0);
 144                 } else if (domkdir) {
 145                         if (mkdir(path, 0700) == 0)
 146                                 return(1);
 147                         if (errno != EEXIST)
 148                                 return(0);
 149                 } else if (lstat(path, &sbuf))
 150                         return(errno == ENOENT ? 1 : 0);
 151
 152                 /* tricky little algorithm for backward compatibility */
 153                 for (trv = start;;) {
 154                         if (!*trv)
 155                                 return (0);
 156                         if (*trv == 'Z') {
 157                                 if (trv == suffp)
 158                                         return (0);
 159                                 *trv++ = 'a';
 160                         } else {
 161                                 if (isdigit(*trv))
 162                                         *trv = 'a';
 163                                 else if (*trv == 'z')   /* inc from z to A */
 164                                         *trv = 'A';
 165                                 else {
 166                                         if (trv == suffp)
 167                                                 return (0);
 168                                         ++*trv;
 169                                 }
 170                                 break;
 171                         }
 172                 }
 173         }
 174         /*NOTREACHED*/
 175 }
 176
 177 #endif /* !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP) */