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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)mktemp.c 8.1 (Berkeley) 6/4/93 30 * $FreeBSD: src/lib/libc/stdio/mktemp.c,v 1.31 2008/07/28 21:18:59 jhb Exp $ 31 * $DragonFly: src/lib/libc/stdio/mktemp.c,v 1.7 2005/11/20 11:07:30 swildner Exp $ 32 */ 33 34 #include "namespace.h" 35 #include <sys/param.h> 36 #include <sys/stat.h> 37 #include <fcntl.h> 38 #include <errno.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <ctype.h> 43 #include <unistd.h> 44 #include "un-namespace.h" 45 46 char *_mktemp(char *); 47 48 static int _gettemp(char *, int *, int, int); 49 50 static const unsigned char padchar[] = 51 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 52 53 int 54 mkstemps(char *path, int slen) 55 { 56 int fd; 57 58 return (_gettemp(path, &fd, 0, slen) ? fd : -1); 59 } 60 61 int 62 mkstemp(char *path) 63 { 64 int fd; 65 66 return (_gettemp(path, &fd, 0, 0) ? fd : -1); 67 } 68 69 char * 70 mkdtemp(char *path) 71 { 72 return (_gettemp(path, NULL, 1, 0) ? path : NULL); 73 } 74 75 char * 76 _mktemp(char *path) 77 { 78 return (_gettemp(path, NULL, 0, 0) ? path : NULL); 79 } 80 81 __warn_references(mktemp, 82 "warning: mktemp() possibly used unsafely; consider using mkstemp()"); 83 84 char * 85 mktemp(char *path) 86 { 87 return (_mktemp(path)); 88 } 89 90 static int 91 _gettemp(char *path, int *doopen, int domkdir, int slen) 92 { 93 char *start, *trv, *suffp, *carryp; 94 char *pad; 95 struct stat sbuf; 96 int rval; 97 uint32_t rand; 98 char carrybuf[MAXPATHLEN]; 99 100 if ((doopen != NULL && domkdir) || slen < 0) { 101 errno = EINVAL; 102 return (0); 103 } 104 105 for (trv = path; *trv != '\0'; ++trv) 106 ; 107 trv -= slen; 108 suffp = trv; 109 --trv; 110 if (trv < path || NULL != strchr(suffp, '/')) { 111 errno = EINVAL; 112 return (0); 113 } 114 115 /* Fill space with random characters */ 116 while (trv >= path && *trv == 'X') { 117 rand = arc4random_uniform(sizeof(padchar) - 1); 118 *trv-- = padchar[rand]; 119 } 120 start = trv + 1; 121 122 /* save first combination of random characters */ 123 memcpy(carrybuf, start, suffp - start); 124 125 /* 126 * check the target directory. 127 */ 128 if (doopen != NULL || domkdir) { 129 for (; trv > path; --trv) { 130 if (*trv == '/') { 131 *trv = '\0'; 132 rval = stat(path, &sbuf); 133 *trv = '/'; 134 if (rval != 0) 135 return (0); 136 if (!S_ISDIR(sbuf.st_mode)) { 137 errno = ENOTDIR; 138 return (0); 139 } 140 break; 141 } 142 } 143 } 144 145 for (;;) { 146 if (doopen) { 147 if ((*doopen = 148 _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 149 return (1); 150 if (errno != EEXIST) 151 return (0); 152 } else if (domkdir) { 153 if (mkdir(path, 0700) == 0) 154 return (1); 155 if (errno != EEXIST) 156 return (0); 157 } else if (lstat(path, &sbuf)) 158 return (errno == ENOENT); 159 160 /* If we have a collision, cycle through the space of filenames */ 161 for (trv = start, carryp = carrybuf;;) { 162 /* have we tried all possible permutations? */ 163 if (trv == suffp) 164 return (0); /* yes - exit with EEXIST */ 165 pad = strchr(padchar, *trv); 166 if (pad == NULL) { 167 /* this should never happen */ 168 errno = EIO; 169 return (0); 170 } 171 /* increment character */ 172 *trv = (*++pad == '\0') ? padchar[0] : *pad; 173 /* carry to next position? */ 174 if (*trv == *carryp) { 175 /* increment position and loop */ 176 ++trv; 177 ++carryp; 178 } else { 179 /* try with new name */ 180 break; 181 } 182 } 183 } 184 /*NOTREACHED*/ 185 } 186