1 /* $NetBSD: gettemp.c,v 1.17 2014/01/21 19:09:48 seanb Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #if HAVE_NBTOOL_CONFIG_H 33 #include "nbtool_config.h" 34 #endif 35 36 #if !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP 37 38 #include <sys/cdefs.h> 39 #if defined(LIBC_SCCS) && !defined(lint) 40 #if 0 41 static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93"; 42 #else 43 __RCSID("$NetBSD: gettemp.c,v 1.17 2014/01/21 19:09:48 seanb Exp $"); 44 #endif 45 #endif /* LIBC_SCCS and not lint */ 46 47 #include <sys/types.h> 48 #include <sys/stat.h> 49 50 #include <assert.h> 51 #include <ctype.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <unistd.h> 57 58 #if HAVE_NBTOOL_CONFIG_H 59 #define GETTEMP __nbcompat_gettemp 60 #else 61 #include "reentrant.h" 62 #include "local.h" 63 #define GETTEMP __gettemp 64 #endif 65 66 int 67 GETTEMP(char *path, int *doopen, int domkdir) 68 { 69 char *start, *trv; 70 struct stat sbuf; 71 u_int pid; 72 73 /* To guarantee multiple calls generate unique names even if 74 the file is not created. 676 different possibilities with 7 75 or more X's, 26 with 6 or less. */ 76 static char xtra[2] = "aa"; 77 int xcnt = 0; 78 79 _DIAGASSERT(path != NULL); 80 /* doopen may be NULL */ 81 82 pid = getpid(); 83 84 /* Move to end of path and count trailing X's. */ 85 for (trv = path; *trv; ++trv) 86 if (*trv == 'X') 87 xcnt++; 88 else 89 xcnt = 0; 90 91 /* Use at least one from xtra. Use 2 if more than 6 X's. */ 92 if (xcnt > 0) { 93 *--trv = xtra[0]; 94 xcnt--; 95 } 96 if (xcnt > 5) { 97 *--trv = xtra[1]; 98 xcnt--; 99 } 100 101 /* Set remaining X's to pid digits with 0's to the left. */ 102 for (; xcnt > 0; xcnt--) { 103 *--trv = (pid % 10) + '0'; 104 pid /= 10; 105 } 106 107 /* update xtra for next call. */ 108 if (xtra[0] != 'z') 109 xtra[0]++; 110 else { 111 xtra[0] = 'a'; 112 if (xtra[1] != 'z') 113 xtra[1]++; 114 else 115 xtra[1] = 'a'; 116 } 117 118 /* 119 * check the target directory; if you have six X's and it 120 * doesn't exist this runs for a *very* long time. 121 */ 122 for (start = trv + 1;; --trv) { 123 if (trv <= path) 124 break; 125 if (*trv == '/') { 126 int e; 127 *trv = '\0'; 128 e = stat(path, &sbuf); 129 *trv = '/'; 130 if (e == -1) 131 return doopen == NULL && !domkdir; 132 if (!S_ISDIR(sbuf.st_mode)) { 133 errno = ENOTDIR; 134 return doopen == NULL && !domkdir; 135 } 136 break; 137 } 138 } 139 140 for (;;) { 141 if (doopen) { 142 if ((*doopen = 143 open(path, O_CREAT | O_EXCL | O_RDWR, 0600)) >= 0) 144 return 1; 145 if (errno != EEXIST) 146 return 0; 147 } else if (domkdir) { 148 if (mkdir(path, 0700) >= 0) 149 return 1; 150 if (errno != EEXIST) 151 return 0; 152 } else if (lstat(path, &sbuf)) 153 return errno == ENOENT ? 1 : 0; 154 155 /* tricky little algorithm for backward compatibility */ 156 for (trv = start;;) { 157 if (!*trv) 158 return 0; 159 if (*trv == 'z') 160 *trv++ = 'a'; 161 else { 162 if (isdigit((unsigned char)*trv)) 163 *trv = 'a'; 164 else 165 ++*trv; 166 break; 167 } 168 } 169 } 170 /*NOTREACHED*/ 171 } 172 173 #endif /* !HAVE_NBTOOL_CONFIG_H || !HAVE_MKSTEMP || !HAVE_MKDTEMP */ 174