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, int); 51 52 static const unsigned char padchar[] = 53 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 54 55 int 56 mkostemps(char *path, int slen, int oflags) 57 { 58 int fd; 59 60 return (_gettemp(path, &fd, 0, slen, oflags) ? fd : -1); 61 } 62 63 int 64 mkstemps(char *path, int slen) 65 { 66 int fd; 67 68 return (_gettemp(path, &fd, 0, slen, 0) ? fd : -1); 69 } 70 71 int 72 mkostemp(char *path, int oflags) 73 { 74 int fd; 75 76 return (_gettemp(path, &fd, 0, 0, oflags) ? fd : -1); 77 } 78 79 int 80 mkstemp(char *path) 81 { 82 int fd; 83 84 return (_gettemp(path, &fd, 0, 0, 0) ? fd : -1); 85 } 86 87 char * 88 mkdtemp(char *path) 89 { 90 return (_gettemp(path, (int *)NULL, 1, 0, 0) ? path : (char *)NULL); 91 } 92 93 char * 94 _mktemp(char *path) 95 { 96 return (_gettemp(path, (int *)NULL, 0, 0, 0) ? path : (char *)NULL); 97 } 98 99 __warn_references(mktemp, 100 "warning: mktemp() possibly used unsafely; consider using mkstemp()"); 101 102 char * 103 mktemp(char *path) 104 { 105 return (_mktemp(path)); 106 } 107 108 static int 109 _gettemp(char *path, int *doopen, int domkdir, int slen, int oflags) 110 { 111 char *start, *trv, *suffp, *carryp; 112 char *pad; 113 struct stat sbuf; 114 int rval; 115 uint32_t rand; 116 char carrybuf[MAXPATHLEN]; 117 118 if ((doopen != NULL && domkdir) || slen < 0 || 119 (oflags & ~(O_APPEND | O_DIRECT | O_SHLOCK | O_EXLOCK | O_SYNC | 120 O_CLOEXEC)) != 0) { 121 errno = EINVAL; 122 return (0); 123 } 124 125 for (trv = path; *trv != '\0'; ++trv) 126 ; 127 if (trv - path >= MAXPATHLEN) { 128 errno = ENAMETOOLONG; 129 return (0); 130 } 131 trv -= slen; 132 suffp = trv; 133 --trv; 134 if (trv < path || NULL != strchr(suffp, '/')) { 135 errno = EINVAL; 136 return (0); 137 } 138 139 /* Fill space with random characters */ 140 while (trv >= path && *trv == 'X') { 141 rand = arc4random_uniform(sizeof(padchar) - 1); 142 *trv-- = padchar[rand]; 143 } 144 start = trv + 1; 145 146 /* save first combination of random characters */ 147 memcpy(carrybuf, start, suffp - start); 148 149 /* 150 * check the target directory. 151 */ 152 if (doopen != NULL || domkdir) { 153 for (; trv > path; --trv) { 154 if (*trv == '/') { 155 *trv = '\0'; 156 rval = stat(path, &sbuf); 157 *trv = '/'; 158 if (rval != 0) 159 return (0); 160 if (!S_ISDIR(sbuf.st_mode)) { 161 errno = ENOTDIR; 162 return (0); 163 } 164 break; 165 } 166 } 167 } 168 169 for (;;) { 170 if (doopen) { 171 if ((*doopen = 172 _open(path, O_CREAT|O_EXCL|O_RDWR|oflags, 0600)) >= 173 0) 174 return (1); 175 if (errno != EEXIST) 176 return (0); 177 } else if (domkdir) { 178 if (mkdir(path, 0700) == 0) 179 return (1); 180 if (errno != EEXIST) 181 return (0); 182 } else if (lstat(path, &sbuf)) 183 return (errno == ENOENT); 184 185 /* If we have a collision, cycle through the space of filenames */ 186 for (trv = start, carryp = carrybuf;;) { 187 /* have we tried all possible permutations? */ 188 if (trv == suffp) 189 return (0); /* yes - exit with EEXIST */ 190 pad = strchr(padchar, *trv); 191 if (pad == NULL) { 192 /* this should never happen */ 193 errno = EIO; 194 return (0); 195 } 196 /* increment character */ 197 *trv = (*++pad == '\0') ? padchar[0] : *pad; 198 /* carry to next position? */ 199 if (*trv == *carryp) { 200 /* increment position and loop */ 201 ++trv; 202 ++carryp; 203 } else { 204 /* try with new name */ 205 break; 206 } 207 } 208 } 209 /*NOTREACHED*/ 210 } 211