1 /*	$NetBSD: cd9660_conversion.c,v 1.4 2007/03/14 14:11:17 christos Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
5  *
6  * Copyright (c) 2005 Daniel Watt, Walter Deignan, Ryan Gabrys, Alan
7  * Perez-Rathke and Ram Vedam.  All rights reserved.
8  *
9  * This code was written by Daniel Watt, Walter Deignan, Ryan Gabrys,
10  * Alan Perez-Rathke and Ram Vedam.
11  *
12  * Redistribution and use in source and binary forms, with or
13  * without modification, are permitted provided that the following
14  * conditions are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above
18  *    copyright notice, this list of conditions and the following
19  *    disclaimer in the documentation and/or other materials provided
20  *    with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY DANIEL WATT, WALTER DEIGNAN, RYAN
23  * GABRYS, ALAN PEREZ-RATHKE AND RAM VEDAM ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26  * DISCLAIMED.  IN NO EVENT SHALL DANIEL WATT, WALTER DEIGNAN, RYAN
27  * GABRYS, ALAN PEREZ-RATHKE AND RAM VEDAM BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
30  * USE,DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
34  * OF SUCH DAMAGE.
35  */
36 #include "cd9660.h"
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 static char cd9660_compute_gm_offset(time_t);
42 
43 #if 0
44 static inline int
45 cd9660_pad_even(length)
46 int length;
47 {
48 	return length + (length & 0x01);
49 }
50 #endif
51 
52 /*
53 * These can probably be implemented using a macro
54 */
55 
56 /* Little endian */
57 void
58 cd9660_721(uint16_t w, unsigned char *twochar)
59 {
60 #if BYTE_ORDER == BIG_ENDIAN
61 	w = bswap16(w);
62 #endif
63 	memcpy(twochar,&w,2);
64 }
65 
66 void
67 cd9660_731(uint32_t w, unsigned char *fourchar)
68 {
69 #if BYTE_ORDER == BIG_ENDIAN
70 	w = bswap32(w);
71 #endif
72 	memcpy(fourchar,&w,4);
73 }
74 
75 /* Big endian */
76 void
77 cd9660_722(uint16_t w, unsigned char *twochar)
78 {
79 #if BYTE_ORDER == LITTLE_ENDIAN
80 	w = bswap16(w);
81 #endif
82 	memcpy(twochar,&w,2);
83 }
84 
85 void
86 cd9660_732(uint32_t w, unsigned char *fourchar)
87 {
88 #if BYTE_ORDER == LITTLE_ENDIAN
89 	w = bswap32(w);
90 #endif
91 	memcpy(fourchar,&w,4);
92 }
93 
94 /**
95 * Convert a dword into a double endian string of eight characters
96 * @param int The double word to convert
97 * @param char* The string to write the both endian double word to - It is assumed this is allocated and at least
98 *		eight characters long
99 */
100 void
101 cd9660_bothendian_dword(uint32_t dw, unsigned char *eightchar)
102 {
103 	uint32_t le, be;
104 #if BYTE_ORDER == LITTLE_ENDIAN
105 	le = dw;
106 	be = bswap32(dw);
107 #endif
108 #if BYTE_ORDER == BIG_ENDIAN
109 	be = dw;
110 	le = bswap32(dw);
111 #endif
112 	memcpy(eightchar, &le, 4);
113 	memcpy((eightchar+4), &be, 4);
114 }
115 
116 /**
117 * Convert a word into a double endian string of four characters
118 * @param int The word to convert
119 * @param char* The string to write the both endian word to - It is assumed this is allocated and at least
120 *		four characters long
121 */
122 void
123 cd9660_bothendian_word(uint16_t dw, unsigned char *fourchar)
124 {
125 	uint16_t le, be;
126 #if BYTE_ORDER == LITTLE_ENDIAN
127 	le = dw;
128 	be = bswap16(dw);
129 #endif
130 #if BYTE_ORDER == BIG_ENDIAN
131 	be = dw;
132 	le = bswap16(dw);
133 #endif
134 	memcpy(fourchar, &le, 2);
135 	memcpy((fourchar+2), &be, 2);
136 }
137 
138 void
139 cd9660_pad_string_spaces(char *str, int len)
140 {
141 	int i;
142 
143 	for (i = 0; i < len; i ++) {
144 		if (str[i] == '\0')
145 			str[i] = 0x20;
146 	}
147 }
148 
149 static char
150 cd9660_compute_gm_offset(time_t tim)
151 {
152 	struct tm t, gm;
153 
154 	(void)localtime_r(&tim, &t);
155 	(void)gmtime_r(&tim, &gm);
156 	gm.tm_year -= t.tm_year;
157 	gm.tm_yday -= t.tm_yday;
158 	gm.tm_hour -= t.tm_hour;
159 	gm.tm_min  -= t.tm_min;
160 	if (gm.tm_year < 0)
161 		gm.tm_yday = -1;
162 	else if (gm.tm_year > 0)
163 		gm.tm_yday = 1;
164 
165 	return (char)(-(gm.tm_min + 60* (24 * gm.tm_yday + gm.tm_hour)) / 15);
166 }
167 
168 /* Long dates: 17 characters */
169 void
170 cd9660_time_8426(unsigned char *buf, time_t tim)
171 {
172 	struct tm t;
173 	char temp[18];
174 
175 	(void)localtime_r(&tim, &t);
176 	(void)snprintf(temp, sizeof(temp), "%04i%02i%02i%02i%02i%02i%02i",
177 		1900+(int)t.tm_year,
178 		(int)t.tm_mon+1,
179 		(int)t.tm_mday,
180 		(int)t.tm_hour,
181 		(int)t.tm_min,
182 		(int)t.tm_sec,
183 		0);
184 	(void)memcpy(buf, temp, 16);
185 	buf[16] = cd9660_compute_gm_offset(tim);
186 }
187 
188 /* Short dates: 7 characters */
189 void
190 cd9660_time_915(unsigned char *buf, time_t tim)
191 {
192 	struct tm t;
193 
194 	(void)localtime_r(&tim, &t);
195 	buf[0] = t.tm_year;
196 	buf[1] = t.tm_mon+1;
197 	buf[2] = t.tm_mday;
198 	buf[3] = t.tm_hour;
199 	buf[4] = t.tm_min;
200 	buf[5] = t.tm_sec;
201 	buf[6] = cd9660_compute_gm_offset(tim);
202 }
203