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 * 4. 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 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 32 #endif /* LIBC_SCCS and not lint */ 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include "namespace.h" 37 #include <sys/param.h> 38 #include <sys/stat.h> 39 #include <fcntl.h> 40 #include <errno.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <ctype.h> 45 #include <unistd.h> 46 #include "un-namespace.h" 47 48 char *_mktemp(char *); 49 50 static int _gettemp(char *, int *, int, int); 51 52 static const unsigned char padchar[] = 53 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 54 55 int 56 mkstemps(path, slen) 57 char *path; 58 int slen; 59 { 60 int fd; 61 62 return (_gettemp(path, &fd, 0, slen) ? fd : -1); 63 } 64 65 int 66 mkstemp(path) 67 char *path; 68 { 69 int fd; 70 71 return (_gettemp(path, &fd, 0, 0) ? fd : -1); 72 } 73 74 char * 75 mkdtemp(path) 76 char *path; 77 { 78 return (_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL); 79 } 80 81 char * 82 _mktemp(path) 83 char *path; 84 { 85 return (_gettemp(path, (int *)NULL, 0, 0) ? path : (char *)NULL); 86 } 87 88 __warn_references(mktemp, 89 "warning: mktemp() possibly used unsafely; consider using mkstemp()"); 90 91 char * 92 mktemp(path) 93 char *path; 94 { 95 return (_mktemp(path)); 96 } 97 98 static int 99 _gettemp(path, doopen, domkdir, slen) 100 char *path; 101 int *doopen; 102 int domkdir; 103 int slen; 104 { 105 char *start, *trv, *suffp, *carryp; 106 char *pad; 107 struct stat sbuf; 108 int rval; 109 uint32_t rand; 110 char carrybuf[MAXPATHLEN]; 111 112 if ((doopen != NULL && domkdir) || slen < 0) { 113 errno = EINVAL; 114 return (0); 115 } 116 117 for (trv = path; *trv != '\0'; ++trv) 118 ; 119 if (trv - path >= MAXPATHLEN) { 120 errno = ENAMETOOLONG; 121 return (0); 122 } 123 trv -= slen; 124 suffp = trv; 125 --trv; 126 if (trv < path || NULL != strchr(suffp, '/')) { 127 errno = EINVAL; 128 return (0); 129 } 130 131 /* Fill space with random characters */ 132 while (trv >= path && *trv == 'X') { 133 rand = arc4random_uniform(sizeof(padchar) - 1); 134 *trv-- = padchar[rand]; 135 } 136 start = trv + 1; 137 138 /* save first combination of random characters */ 139 memcpy(carrybuf, start, suffp - start); 140 141 /* 142 * check the target directory. 143 */ 144 if (doopen != NULL || domkdir) { 145 for (; trv > path; --trv) { 146 if (*trv == '/') { 147 *trv = '\0'; 148 rval = stat(path, &sbuf); 149 *trv = '/'; 150 if (rval != 0) 151 return (0); 152 if (!S_ISDIR(sbuf.st_mode)) { 153 errno = ENOTDIR; 154 return (0); 155 } 156 break; 157 } 158 } 159 } 160 161 for (;;) { 162 if (doopen) { 163 if ((*doopen = 164 _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 165 return (1); 166 if (errno != EEXIST) 167 return (0); 168 } else if (domkdir) { 169 if (mkdir(path, 0700) == 0) 170 return (1); 171 if (errno != EEXIST) 172 return (0); 173 } else if (lstat(path, &sbuf)) 174 return (errno == ENOENT); 175 176 /* If we have a collision, cycle through the space of filenames */ 177 for (trv = start, carryp = carrybuf;;) { 178 /* have we tried all possible permutations? */ 179 if (trv == suffp) 180 return (0); /* yes - exit with EEXIST */ 181 pad = strchr(padchar, *trv); 182 if (pad == NULL) { 183 /* this should never happen */ 184 errno = EIO; 185 return (0); 186 } 187 /* increment character */ 188 *trv = (*++pad == '\0') ? padchar[0] : *pad; 189 /* carry to next position? */ 190 if (*trv == *carryp) { 191 /* increment position and loop */ 192 ++trv; 193 ++carryp; 194 } else { 195 /* try with new name */ 196 break; 197 } 198 } 199 } 200 /*NOTREACHED*/ 201 } 202