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 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(char *path, int slen) 57 { 58 int fd; 59 60 return (_gettemp(path, &fd, 0, slen) ? fd : -1); 61 } 62 63 int 64 mkstemp(char *path) 65 { 66 int fd; 67 68 return (_gettemp(path, &fd, 0, 0) ? fd : -1); 69 } 70 71 char * 72 mkdtemp(char *path) 73 { 74 return (_gettemp(path, (int *)NULL, 1, 0) ? path : (char *)NULL); 75 } 76 77 char * 78 _mktemp(char *path) 79 { 80 return (_gettemp(path, (int *)NULL, 0, 0) ? path : (char *)NULL); 81 } 82 83 __warn_references(mktemp, 84 "warning: mktemp() possibly used unsafely; consider using mkstemp()"); 85 86 char * 87 mktemp(char *path) 88 { 89 return (_mktemp(path)); 90 } 91 92 static int 93 _gettemp(char *path, int *doopen, int domkdir, int slen) 94 { 95 char *start, *trv, *suffp, *carryp; 96 char *pad; 97 struct stat sbuf; 98 int rval; 99 uint32_t rand; 100 char carrybuf[MAXPATHLEN]; 101 102 if ((doopen != NULL && domkdir) || slen < 0) { 103 errno = EINVAL; 104 return (0); 105 } 106 107 for (trv = path; *trv != '\0'; ++trv) 108 ; 109 if (trv - path >= MAXPATHLEN) { 110 errno = ENAMETOOLONG; 111 return (0); 112 } 113 trv -= slen; 114 suffp = trv; 115 --trv; 116 if (trv < path || NULL != strchr(suffp, '/')) { 117 errno = EINVAL; 118 return (0); 119 } 120 121 /* Fill space with random characters */ 122 while (trv >= path && *trv == 'X') { 123 rand = arc4random_uniform(sizeof(padchar) - 1); 124 *trv-- = padchar[rand]; 125 } 126 start = trv + 1; 127 128 /* save first combination of random characters */ 129 memcpy(carrybuf, start, suffp - start); 130 131 /* 132 * check the target directory. 133 */ 134 if (doopen != NULL || domkdir) { 135 for (; trv > path; --trv) { 136 if (*trv == '/') { 137 *trv = '\0'; 138 rval = stat(path, &sbuf); 139 *trv = '/'; 140 if (rval != 0) 141 return (0); 142 if (!S_ISDIR(sbuf.st_mode)) { 143 errno = ENOTDIR; 144 return (0); 145 } 146 break; 147 } 148 } 149 } 150 151 for (;;) { 152 if (doopen) { 153 if ((*doopen = 154 _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) 155 return (1); 156 if (errno != EEXIST) 157 return (0); 158 } else if (domkdir) { 159 if (mkdir(path, 0700) == 0) 160 return (1); 161 if (errno != EEXIST) 162 return (0); 163 } else if (lstat(path, &sbuf)) 164 return (errno == ENOENT); 165 166 /* If we have a collision, cycle through the space of filenames */ 167 for (trv = start, carryp = carrybuf;;) { 168 /* have we tried all possible permutations? */ 169 if (trv == suffp) 170 return (0); /* yes - exit with EEXIST */ 171 pad = strchr(padchar, *trv); 172 if (pad == NULL) { 173 /* this should never happen */ 174 errno = EIO; 175 return (0); 176 } 177 /* increment character */ 178 *trv = (*++pad == '\0') ? padchar[0] : *pad; 179 /* carry to next position? */ 180 if (*trv == *carryp) { 181 /* increment position and loop */ 182 ++trv; 183 ++carryp; 184 } else { 185 /* try with new name */ 186 break; 187 } 188 } 189 } 190 /*NOTREACHED*/ 191 } 192