maxwen | 27116ba | 2015-08-14 21:41:28 +0200 | [diff] [blame] | 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 <sys/param.h> |
| 37 | #include <sys/stat.h> |
| 38 | #include <fcntl.h> |
| 39 | #include <errno.h> |
| 40 | #include <stdio.h> |
| 41 | #include <stdlib.h> |
| 42 | #include <string.h> |
| 43 | #include <ctype.h> |
| 44 | #include <unistd.h> |
| 45 | |
| 46 | extern u_int32_t arc4random_uniform(u_int32_t); |
| 47 | #define _open open |
| 48 | |
| 49 | static int _gettemp(char *, int *, int, int); |
| 50 | |
| 51 | static const char padchar[] = |
| 52 | "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; |
| 53 | |
| 54 | static char * |
| 55 | _mktemp(char *path) |
| 56 | { |
| 57 | return (_gettemp(path, (int *)NULL, 0, 0) ? path : (char *)NULL); |
| 58 | } |
| 59 | |
| 60 | char * |
| 61 | bb_mktemp(char *path) |
| 62 | { |
| 63 | return (_mktemp(path)); |
| 64 | } |
| 65 | |
| 66 | static int |
| 67 | _gettemp(char *path, int *doopen, int domkdir, int slen) |
| 68 | { |
| 69 | char *start, *trv, *suffp, *carryp; |
| 70 | char *pad; |
| 71 | struct stat sbuf; |
| 72 | int rval; |
| 73 | uint32_t rand; |
| 74 | char carrybuf[MAXPATHLEN]; |
| 75 | |
| 76 | if ((doopen != NULL && domkdir) || slen < 0) { |
| 77 | errno = EINVAL; |
| 78 | return (0); |
| 79 | } |
| 80 | |
| 81 | for (trv = path; *trv != '\0'; ++trv) |
| 82 | ; |
| 83 | if (trv - path >= MAXPATHLEN) { |
| 84 | errno = ENAMETOOLONG; |
| 85 | return (0); |
| 86 | } |
| 87 | trv -= slen; |
| 88 | suffp = trv; |
| 89 | --trv; |
| 90 | if (trv < path || NULL != strchr(suffp, '/')) { |
| 91 | errno = EINVAL; |
| 92 | return (0); |
| 93 | } |
| 94 | |
| 95 | /* Fill space with random characters */ |
| 96 | while (trv >= path && *trv == 'X') { |
| 97 | rand = arc4random_uniform(sizeof(padchar) - 1); |
| 98 | *trv-- = padchar[rand]; |
| 99 | } |
| 100 | start = trv + 1; |
| 101 | |
| 102 | /* save first combination of random characters */ |
| 103 | memcpy(carrybuf, start, suffp - start); |
| 104 | |
| 105 | /* |
| 106 | * check the target directory. |
| 107 | */ |
| 108 | if (doopen != NULL || domkdir) { |
| 109 | for (; trv > path; --trv) { |
| 110 | if (*trv == '/') { |
| 111 | *trv = '\0'; |
| 112 | rval = stat(path, &sbuf); |
| 113 | *trv = '/'; |
| 114 | if (rval != 0) |
| 115 | return (0); |
| 116 | if (!S_ISDIR(sbuf.st_mode)) { |
| 117 | errno = ENOTDIR; |
| 118 | return (0); |
| 119 | } |
| 120 | break; |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | for (;;) { |
| 126 | if (doopen) { |
| 127 | if ((*doopen = |
| 128 | _open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) |
| 129 | return (1); |
| 130 | if (errno != EEXIST) |
| 131 | return (0); |
| 132 | } else if (domkdir) { |
| 133 | if (mkdir(path, 0700) == 0) |
| 134 | return (1); |
| 135 | if (errno != EEXIST) |
| 136 | return (0); |
| 137 | } else if (lstat(path, &sbuf)) |
| 138 | return (errno == ENOENT); |
| 139 | |
| 140 | /* If we have a collision, cycle through the space of filenames */ |
| 141 | for (trv = start, carryp = carrybuf;;) { |
| 142 | /* have we tried all possible permutations? */ |
| 143 | if (trv == suffp) |
| 144 | return (0); /* yes - exit with EEXIST */ |
| 145 | pad = strchr(padchar, *trv); |
| 146 | if (pad == NULL) { |
| 147 | /* this should never happen */ |
| 148 | errno = EIO; |
| 149 | return (0); |
| 150 | } |
| 151 | /* increment character */ |
| 152 | *trv = (*++pad == '\0') ? padchar[0] : *pad; |
| 153 | /* carry to next position? */ |
| 154 | if (*trv == *carryp) { |
| 155 | /* increment position and loop */ |
| 156 | ++trv; |
| 157 | ++carryp; |
| 158 | } else { |
| 159 | /* try with new name */ |
| 160 | break; |
| 161 | } |
| 162 | } |
| 163 | } |
| 164 | /*NOTREACHED*/ |
| 165 | } |