crypto/openssh-3.8.1p1/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 #ifdef HAVE_CYGWIN
  44 #define open binary_open
  45 extern int binary_open();
  46 #endif
  47
  48 static int _gettemp(char *, int *, int, int);
  49
  50 int
  51 mkstemps(path, slen)
  52         char *path;
  53         int slen;
  54 {
  55         int fd;
  56
  57         return (_gettemp(path, &fd, 0, slen) ? fd : -1);
  58 }
  59
  60 int
  61 mkstemp(path)
  62         char *path;
  63 {
  64         int fd;
  65
  66         return (_gettemp(path, &fd, 0, 0) ? fd : -1);
  67 }
  68
  69 char *
  70 mkdtemp(path)
  71         char *path;
  72 {
  73         return(_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL);
  74 }
  75
  76 static int
  77 _gettemp(path, doopen, domkdir, slen)
  78         char *path;
  79         register int *doopen;
  80         int domkdir;
  81         int slen;
  82 {
  83         register char *start, *trv, *suffp;
  84         struct stat sbuf;
  85         int rval;
  86         pid_t pid;
  87
  88         if (doopen && domkdir) {
  89                 errno = EINVAL;
  90                 return(0);
  91         }
  92
  93         for (trv = path; *trv; ++trv)
  94                 ;
  95         trv -= slen;
  96         suffp = trv;
  97         --trv;
  98         if (trv < path) {
  99                 errno = EINVAL;
 100                 return (0);
 101         }
 102         pid = getpid();
 103         while (trv >= path && *trv == 'X' && pid != 0) {
 104                 *trv-- = (pid % 10) + '0';
 105                 pid /= 10;
 106         }
 107         while (trv >= path && *trv == 'X') {
 108                 char c;
 109
 110                 pid = (arc4random() & 0xffff) % (26+26);
 111                 if (pid < 26)
 112                         c = pid + 'A';
 113                 else
 114                         c = (pid - 26) + 'a';
 115                 *trv-- = c;
 116         }
 117         start = trv + 1;
 118
 119         /*
 120          * check the target directory; if you have six X's and it
 121          * doesn't exist this runs for a *very* long time.
 122          */
 123         if (doopen || domkdir) {
 124                 for (;; --trv) {
 125                         if (trv <= path)
 126                                 break;
 127                         if (*trv == '/') {
 128                                 *trv = '\0';
 129                                 rval = stat(path, &sbuf);
 130                                 *trv = '/';
 131                                 if (rval != 0)
 132                                         return(0);
 133                                 if (!S_ISDIR(sbuf.st_mode)) {
 134                                         errno = ENOTDIR;
 135                                         return(0);
 136                                 }
 137                                 break;
 138                         }
 139                 }
 140         }
 141
 142         for (;;) {
 143                 if (doopen) {
 144                         if ((*doopen =
 145                             open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
 146                                 return(1);
 147                         if (errno != EEXIST)
 148                                 return(0);
 149                 } else if (domkdir) {
 150                         if (mkdir(path, 0700) == 0)
 151                                 return(1);
 152                         if (errno != EEXIST)
 153                                 return(0);
 154                 } else if (lstat(path, &sbuf))
 155                         return(errno == ENOENT ? 1 : 0);
 156
 157                 /* tricky little algorithm for backward compatibility */
 158                 for (trv = start;;) {
 159                         if (!*trv)
 160                                 return (0);
 161                         if (*trv == 'Z') {
 162                                 if (trv == suffp)
 163                                         return (0);
 164                                 *trv++ = 'a';
 165                         } else {
 166                                 if (isdigit(*trv))
 167                                         *trv = 'a';
 168                                 else if (*trv == 'z')   /* inc from z to A */
 169                                         *trv = 'A';
 170                                 else {
 171                                         if (trv == suffp)
 172                                                 return (0);
 173                                         ++*trv;
 174                                 }
 175                                 break;
 176                         }
 177                 }
 178         }
 179         /*NOTREACHED*/
 180 }
 181
 182 #endif /* !defined(HAVE_MKDTEMP) || defined(HAVE_STRICT_MKSTEMP) */