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, 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, 0) ? fd : -1); 59 } 60 61 int 62 mkostemps(char *path, int slen, int oflags) 63 { 64 int fd; 65 66 return (_gettemp(path, &fd, 0, slen, oflags) ? fd : -1); 67 } 68 69 int 70 mkstemp(char *path) 71 { 72 int fd; 73 74 return (_gettemp(path, &fd, 0, 0, 0) ? fd : -1); 75 } 76 77 int 78 mkostemp(char *path, int oflags) 79 { 80 int fd; 81 82 return (_gettemp(path, &fd, 0, 0, oflags) ? fd : -1); 83 } 84 85 char * 86 mkdtemp(char *path) 87 { 88 return (_gettemp(path, NULL, 1, 0, 0) ? path : NULL); 89 } 90 91 char * 92 _mktemp(char *path) 93 { 94 return (_gettemp(path, NULL, 0, 0, 0) ? path : NULL); 95 } 96 97 __warn_references(mktemp, 98 "warning: mktemp() possibly used unsafely; consider using mkstemp()"); 99 100 char * 101 mktemp(char *path) 102 { 103 return (_mktemp(path)); 104 } 105 106 static int 107 _gettemp(char *path, int *doopen, int domkdir, int slen, int oflags) 108 { 109 char *start, *trv, *suffp, *carryp; 110 char *pad; 111 struct stat sbuf; 112 int rval; 113 uint32_t rand; 114 char carrybuf[MAXPATHLEN]; 115 116 if ((oflags & ~(O_APPEND | O_DIRECT | O_SHLOCK | 117 O_EXLOCK | O_SYNC | O_CLOEXEC)) != 0) { 118 errno = EINVAL; 119 return (0); 120 } 121 if ((doopen != NULL && domkdir) || slen < 0) { 122 errno = EINVAL; 123 return (0); 124 } 125 126 for (trv = path; *trv != '\0'; ++trv) 127 ; 128 trv -= slen; 129 suffp = trv; 130 --trv; 131 if (trv < path || NULL != strchr(suffp, '/')) { 132 errno = EINVAL; 133 return (0); 134 } 135 136 /* Fill space with random characters */ 137 while (trv >= path && *trv == 'X') { 138 rand = arc4random_uniform(sizeof(padchar) - 1); 139 *trv-- = padchar[rand]; 140 } 141 start = trv + 1; 142 143 /* save first combination of random characters */ 144 memcpy(carrybuf, start, suffp - start); 145 146 /* 147 * check the target directory. 148 */ 149 if (doopen != NULL || domkdir) { 150 for (; trv > path; --trv) { 151 if (*trv == '/') { 152 *trv = '\0'; 153 rval = stat(path, &sbuf); 154 *trv = '/'; 155 if (rval != 0) 156 return (0); 157 if (!S_ISDIR(sbuf.st_mode)) { 158 errno = ENOTDIR; 159 return (0); 160 } 161 break; 162 } 163 } 164 } 165 166 for (;;) { 167 if (doopen) { 168 if ((*doopen = 169 _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 170 return (1); 171 if (errno != EEXIST) 172 return (0); 173 } else if (domkdir) { 174 if (mkdir(path, 0700) == 0) 175 return (1); 176 if (errno != EEXIST) 177 return (0); 178 } else if (lstat(path, &sbuf)) 179 return (errno == ENOENT); 180 181 /* If we have a collision, cycle through the space of filenames */ 182 for (trv = start, carryp = carrybuf;;) { 183 /* have we tried all possible permutations? */ 184 if (trv == suffp) 185 return (0); /* yes - exit with EEXIST */ 186 pad = strchr(padchar, *trv); 187 if (pad == NULL) { 188 /* this should never happen */ 189 errno = EIO; 190 return (0); 191 } 192 /* increment character */ 193 *trv = (*++pad == '\0') ? padchar[0] : *pad; 194 /* carry to next position? */ 195 if (*trv == *carryp) { 196 /* increment position and loop */ 197 ++trv; 198 ++carryp; 199 } else { 200 /* try with new name */ 201 break; 202 } 203 } 204 } 205 /*NOTREACHED*/ 206 } 207