1 /* $OpenBSD: tempnam.c,v 1.19 2015/08/31 02:53:57 guenther Exp $ */ 2 /* 3 * Copyright (c) 1988, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <errno.h> 32 #include <limits.h> 33 #include <paths.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 __warn_references(tempnam, 40 "warning: tempnam() possibly used unsafely; consider using mkstemp()"); 41 42 char * 43 tempnam(const char *dir, const char *pfx) 44 { 45 int sverrno, len; 46 char *f, *name; 47 48 if (!(name = malloc(PATH_MAX))) 49 return(NULL); 50 51 if (!pfx) 52 pfx = "tmp."; 53 54 if (issetugid() == 0 && (f = getenv("TMPDIR")) && *f != '\0') { 55 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f, 56 f[strlen(f) - 1] == '/' ? "" : "/", pfx); 57 if (len < 0 || len >= PATH_MAX) { 58 errno = ENAMETOOLONG; 59 goto fail; 60 } 61 if ((f = _mktemp(name))) 62 return(f); 63 } 64 65 if (dir != NULL) { 66 f = *dir ? (char *)dir : "."; 67 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f, 68 f[strlen(f) - 1] == '/' ? "" : "/", pfx); 69 if (len < 0 || len >= PATH_MAX) { 70 errno = ENAMETOOLONG; 71 goto fail; 72 } 73 if ((f = _mktemp(name))) 74 return(f); 75 } 76 77 f = P_tmpdir; 78 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx); 79 if (len < 0 || len >= PATH_MAX) { 80 errno = ENAMETOOLONG; 81 goto fail; 82 } 83 if ((f = _mktemp(name))) 84 return(f); 85 86 f = _PATH_TMP; 87 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx); 88 if (len < 0 || len >= PATH_MAX) { 89 errno = ENAMETOOLONG; 90 goto fail; 91 } 92 if ((f = _mktemp(name))) 93 return(f); 94 95 fail: 96 sverrno = errno; 97 free(name); 98 errno = sverrno; 99 return(NULL); 100 } 101
