1 /* $OpenBSD: tempnam.c,v 1.17 2013/09/30 12:02:35 millert 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 extern char *_mktemp(char *); 43 44 char * 45 tempnam(const char *dir, const char *pfx) 46 { 47 int sverrno, len; 48 char *f, *name; 49 50 if (!(name = malloc(PATH_MAX))) 51 return(NULL); 52 53 if (!pfx) 54 pfx = "tmp."; 55 56 if (issetugid() == 0 && (f = getenv("TMPDIR")) && *f != '\0') { 57 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f, 58 f[strlen(f) - 1] == '/' ? "" : "/", pfx); 59 if (len < 0 || len >= PATH_MAX) { 60 errno = ENAMETOOLONG; 61 return(NULL); 62 } 63 if ((f = _mktemp(name))) 64 return(f); 65 } 66 67 if (dir != NULL) { 68 f = *dir ? (char *)dir : "."; 69 len = snprintf(name, PATH_MAX, "%s%s%sXXXXXXXXXX", f, 70 f[strlen(f) - 1] == '/' ? "" : "/", pfx); 71 if (len < 0 || len >= PATH_MAX) { 72 errno = ENAMETOOLONG; 73 return(NULL); 74 } 75 if ((f = _mktemp(name))) 76 return(f); 77 } 78 79 f = P_tmpdir; 80 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx); 81 if (len < 0 || len >= PATH_MAX) { 82 errno = ENAMETOOLONG; 83 return(NULL); 84 } 85 if ((f = _mktemp(name))) 86 return(f); 87 88 f = _PATH_TMP; 89 len = snprintf(name, PATH_MAX, "%s%sXXXXXXXXX", f, pfx); 90 if (len < 0 || len >= PATH_MAX) { 91 errno = ENAMETOOLONG; 92 return(NULL); 93 } 94 if ((f = _mktemp(name))) 95 return(f); 96 97 sverrno = errno; 98 free(name); 99 errno = sverrno; 100 return(NULL); 101 } 102
