1 /* $NetBSD: gettemp.c,v 1.19 2014/06/19 05:31:15 msaitoh Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include "gettemp.h" 33 34 #if !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: gettemp.c,v 1.19 2014/06/19 05:31:15 msaitoh Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <sys/param.h> 46 #include <fcntl.h> 47 #include <string.h> 48 49 static const unsigned char padchar[] = 50 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 51 52 int 53 GETTEMP(char *path, int *doopen, int domkdir, int slen, int oflags) 54 { 55 char *start, *trv, *suffp, *carryp; 56 char *pad; 57 struct stat sbuf; 58 int rval; 59 uint32_t r; 60 char carrybuf[MAXPATHLEN]; 61 62 _DIAGASSERT(path != NULL); 63 /* doopen may be NULL */ 64 if ((doopen != NULL && domkdir) || slen < 0 || 65 (oflags & ~(O_APPEND | O_DIRECT | O_SHLOCK | O_EXLOCK | O_SYNC | 66 O_CLOEXEC)) != 0) { 67 errno = EINVAL; 68 return 0; 69 } 70 71 for (trv = path; *trv != '\0'; ++trv) 72 continue; 73 74 if (trv - path >= MAXPATHLEN) { 75 errno = ENAMETOOLONG; 76 return 0; 77 } 78 trv -= slen; 79 suffp = trv; 80 --trv; 81 if (trv < path || NULL != strchr(suffp, '/')) { 82 errno = EINVAL; 83 return 0; 84 } 85 86 /* Fill space with random characters */ 87 while (trv >= path && *trv == 'X') { 88 r = arc4random_uniform(sizeof(padchar) - 1); 89 *trv-- = padchar[r]; 90 } 91 start = trv + 1; 92 93 /* save first combination of random characters */ 94 memcpy(carrybuf, start, suffp - start); 95 96 /* 97 * check the target directory. 98 */ 99 if (doopen != NULL || domkdir) { 100 for (; trv > path; --trv) { 101 if (*trv == '/') { 102 *trv = '\0'; 103 rval = stat(path, &sbuf); 104 *trv = '/'; 105 if (rval != 0) 106 return 0; 107 if (!S_ISDIR(sbuf.st_mode)) { 108 errno = ENOTDIR; 109 return 0; 110 } 111 break; 112 } 113 } 114 } 115 116 for (;;) { 117 if (doopen) { 118 if ((*doopen = open(path, O_CREAT|O_EXCL|O_RDWR|oflags, 119 0600)) != -1) 120 return 1; 121 if (errno != EEXIST) 122 return 0; 123 } else if (domkdir) { 124 if (mkdir(path, 0700) != -1) 125 return 1; 126 if (errno != EEXIST) 127 return 0; 128 } else if (lstat(path, &sbuf)) 129 return errno == ENOENT; 130 131 /* 132 * If we have a collision, 133 * cycle through the space of filenames 134 */ 135 for (trv = start, carryp = carrybuf;;) { 136 /* have we tried all possible permutations? */ 137 if (trv == suffp) 138 return 0; /* yes - exit with EEXIST */ 139 pad = strchr((const char *)padchar, *trv); 140 if (pad == NULL) { 141 /* this should never happen */ 142 errno = EIO; 143 return 0; 144 } 145 /* increment character */ 146 *trv = (*++pad == '\0') ? padchar[0] : *pad; 147 /* carry to next position? */ 148 if (*trv == *carryp) { 149 /* increment position and loop */ 150 ++trv; 151 ++carryp; 152 } else { 153 /* try with new name */ 154 break; 155 } 156 } 157 } 158 /*NOTREACHED*/ 159 } 160 161 #endif /* !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */ 162