openbsd-compat/mktemp.c

   1 /* THIS FILE HAS BEEN MODIFIED FROM THE ORIGINAL OPENBSD SOURCE */
   2 /* Changes: Removed mktemp */
   3
   4 /*      $OpenBSD: mktemp.c,v 1.19 2005/08/08 08:05:36 espie Exp $ */
   5 /*
   6  * Copyright (c) 1987, 1993
   7  *      The Regents of the University of California.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. 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 /* OPENBSD ORIGINAL: lib/libc/stdio/mktemp.c */
  35
  36 #include "includes.h"
  37
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40
  41 #include <fcntl.h>
  42 #include <ctype.h>
  43 #include <errno.h>
  44 #include <unistd.h>
  45
  46 #if !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP)
  47
  48 static int _gettemp(char *, int *, int, int);
  49
  50 int
  51 mkstemps(char *path, int slen)
  52 {
  53         int fd;
  54
  55         return (_gettemp(path, &fd, 0, slen) ? fd : -1);
  56 }
  57
  58 int
  59 mkstemp(char *path)
  60 {
  61         int fd;
  62
  63         return (_gettemp(path, &fd, 0, 0) ? fd : -1);
  64 }
  65
  66 char *
  67 mkdtemp(char *path)
  68 {
  69         return(_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
  70 }
  71
  72 static int
  73 _gettemp(path, doopen, domkdir, slen)
  74         char *path;
  75         register int *doopen;
  76         int domkdir;
  77         int slen;
  78 {
  79         register char *start, *trv, *suffp;
  80         struct stat sbuf;
  81         int rval;
  82         pid_t pid;
  83
  84         if (doopen && domkdir) {
  85                 errno = EINVAL;
  86                 return(0);
  87         }
  88
  89         for (trv = path; *trv; ++trv)
  90                 ;
  91         trv -= slen;
  92         suffp = trv;
  93         --trv;
  94         if (trv < path) {
  95                 errno = EINVAL;
  96                 return (0);
  97         }
  98         pid = getpid();
  99         while (trv >= path && *trv == 'X' && pid != 0) {
 100                 *trv-- = (pid % 10) + '0';
 101                 pid /= 10;
 102         }
 103         while (trv >= path && *trv == 'X') {
 104                 char c;
 105
 106                 pid = (arc4random() & 0xffff) % (26+26);
 107                 if (pid < 26)
 108                         c = pid + 'A';
 109                 else
 110                         c = (pid - 26) + 'a';
 111                 *trv-- = c;
 112         }
 113         start = trv + 1;
 114
 115         /*
 116          * check the target directory; if you have six X's and it
 117          * doesn't exist this runs for a *very* long time.
 118          */
 119         if (doopen || domkdir) {
 120                 for (;; --trv) {
 121                         if (trv <= path)
 122                                 break;
 123                         if (*trv == '/') {
 124                                 *trv = '\0';
 125                                 rval = stat(path, &sbuf);
 126                                 *trv = '/';
 127                                 if (rval != 0)
 128                                         return(0);
 129                                 if (!S_ISDIR(sbuf.st_mode)) {
 130                                         errno = ENOTDIR;
 131                                         return(0);
 132                                 }
 133                                 break;
 134                         }
 135                 }
 136         }
 137
 138         for (;;) {
 139                 if (doopen) {
 140                         if ((*doopen =
 141                             open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
 142                                 return(1);
 143                         if (errno != EEXIST)
 144                                 return(0);
 145                 } else if (domkdir) {
 146                         if (mkdir(path, 0700) == 0)
 147                                 return(1);
 148                         if (errno != EEXIST)
 149                                 return(0);
 150                 } else if (lstat(path, &sbuf))
 151                         return(errno == ENOENT ? 1 : 0);
 152
 153                 /* tricky little algorithm for backward compatibility */
 154                 for (trv = start;;) {
 155                         if (!*trv)
 156                                 return (0);
 157                         if (*trv == 'Z') {
 158                                 if (trv == suffp)
 159                                         return (0);
 160                                 *trv++ = 'a';
 161                         } else {
 162                                 if (isdigit(*trv))
 163                                         *trv = 'a';
 164                                 else if (*trv == 'z')   /* inc from z to A */
 165                                         *trv = 'A';
 166                                 else {
 167                                         if (trv == suffp)
 168                                                 return (0);
 169                                         ++*trv;
 170                                 }
 171                                 break;
 172                         }
 173                 }
 174         }
 175         /*NOTREACHED*/
 176 }
 177
 178 #endif /* !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP) */