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/* $OpenBSD: mktemp.c,v 1.38 2015/09/13 08:31:47 guenther Exp $ */ |
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/* |
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* Copyright (c) 1996-1998, 2008 Theo de Raadt |
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* Copyright (c) 1997, 2008-2009 Todd C. Miller |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <limits.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <ctype.h> |
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#include <unistd.h> |
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#define MKTEMP_NAME 0 |
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#define MKTEMP_FILE 1 |
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#define MKTEMP_DIR 2 |
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#define TEMPCHARS "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" |
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#define NUM_CHARS (sizeof(TEMPCHARS) - 1) |
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#define MIN_X 6 |
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#define MKOTEMP_FLAGS (O_APPEND | O_CLOEXEC | O_DSYNC | O_RSYNC | O_SYNC) |
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#ifndef nitems |
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#define nitems(_a) (sizeof((_a)) / sizeof((_a)[0])) |
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#endif |
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static int |
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mktemp_internal(char *path, int slen, int mode, int flags) |
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{ |
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char *start, *cp, *ep; |
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const char tempchars[] = TEMPCHARS; |
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unsigned int tries; |
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struct stat sb; |
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size_t len; |
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int fd; |
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len = strlen(path); |
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if (len < MIN_X || slen < 0 || (size_t)slen > len - MIN_X) { |
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errno = EINVAL; |
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return(-1); |
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} |
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ep = path + len - slen; |
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for (start = ep; start > path && start[-1] == 'X'; start--) |
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; |
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if (ep - start < MIN_X) { |
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errno = EINVAL; |
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return(-1); |
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} |
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if (flags & ~MKOTEMP_FLAGS) { |
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errno = EINVAL; |
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return(-1); |
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} |
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flags |= O_CREAT | O_EXCL | O_RDWR; |
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tries = INT_MAX; |
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do { |
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cp = start; |
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do { |
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unsigned short rbuf[16]; |
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unsigned int i; |
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/* |
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* Avoid lots of arc4random() calls by using |
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* a buffer sized for up to 16 Xs at a time. |
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*/ |
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arc4random_buf(rbuf, sizeof(rbuf)); |
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for (i = 0; i < nitems(rbuf) && cp != ep; i++) |
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*cp++ = tempchars[rbuf[i] % NUM_CHARS]; |
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} while (cp != ep); |
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switch (mode) { |
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case MKTEMP_NAME: |
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if (lstat(path, &sb) != 0) |
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return(errno == ENOENT ? 0 : -1); |
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break; |
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case MKTEMP_FILE: |
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fd = open(path, flags, S_IRUSR|S_IWUSR); |
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if (fd != -1 || errno != EEXIST) |
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return(fd); |
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break; |
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case MKTEMP_DIR: |
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if (mkdir(path, S_IRUSR|S_IWUSR|S_IXUSR) == 0) |
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return(0); |
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if (errno != EEXIST) |
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return(-1); |
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break; |
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} |
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} while (--tries); |
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errno = EEXIST; |
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return(-1); |
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} |
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char * |
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_mktemp(char *path) |
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{ |
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if (mktemp_internal(path, 0, MKTEMP_NAME, 0) == -1) |
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return(NULL); |
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return(path); |
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} |
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__warn_references(mktemp, |
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"warning: mktemp() possibly used unsafely; consider using mkstemp()"); |
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char * |
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mktemp(char *path) |
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{ |
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return(_mktemp(path)); |
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} |
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int |
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mkostemps(char *path, int slen, int flags) |
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{ |
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return(mktemp_internal(path, slen, MKTEMP_FILE, flags)); |
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} |
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int |
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mkstemp(char *path) |
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{ |
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return(mktemp_internal(path, 0, MKTEMP_FILE, 0)); |
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} |
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DEF_WEAK(mkstemp); |
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int |
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mkostemp(char *path, int flags) |
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{ |
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return(mktemp_internal(path, 0, MKTEMP_FILE, flags)); |
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} |
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DEF_WEAK(mkostemp); |
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int |
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mkstemps(char *path, int slen) |
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{ |
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return(mktemp_internal(path, slen, MKTEMP_FILE, 0)); |
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} |
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char * |
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mkdtemp(char *path) |
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{ |
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int error; |
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error = mktemp_internal(path, 0, MKTEMP_DIR, 0); |
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return(error ? NULL : path); |
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} |