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src/sys/msdosfs/msdosfs_conv.c

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/* $OpenBSD: msdosfs_conv.c,v 1.22 2024/09/12 09:07:28 claudio Exp $ */
/* $NetBSD: msdosfs_conv.c,v 1.24 1997/10/17 11:23:54 ws Exp $ */
/*-
* Copyright (C) 1995, 1997 Wolfgang Solfrank.
* Copyright (C) 1995, 1997 TooLs GmbH.
* All rights reserved.
* Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
/*
* System include files.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/kernel.h> /* defines tz */
#include <sys/dirent.h>
#include <sys/vnode.h>
#include <sys/lock.h>
/*
* MSDOSFS include files.
*/
#include <msdosfs/direntry.h>
#include <msdosfs/denode.h>
/*
* Days in each month in a regular year.
*/
const u_short regyear[] = {
31, 28, 31, 30, 31, 30,
31, 31, 30, 31, 30, 31
};
/*
* Days in each month in a leap year.
*/
const u_short leapyear[] = {
31, 29, 31, 30, 31, 30,
31, 31, 30, 31, 30, 31
};
/*
* Variables used to remember parts of the last time conversion. Maybe we
* can avoid a full conversion.
*/
time_t lasttime;
uint32_t lastday;
u_short lastddate;
u_short lastdtime;
/*
* Convert the unix version of time to dos's idea of time to be used in
* file timestamps. The passed in unix time is assumed to be in GMT.
*/
void
unix2dostime(struct timespec *tsp, u_int16_t *ddp, u_int16_t *dtp, u_int8_t *dhp)
{
time_t t;
uint32_t days;
uint32_t inc;
uint32_t year;
uint32_t month;
const u_short *months;
/*
* If the time from the last conversion is the same as now, then
* skip the computations and use the saved result.
*/
t = tsp->tv_sec;
t &= ~1;
/*
* Before 1/1/1980 there is only a timeless void. After 12/31/2107
* there is only Cthulhu.
*/
#define DOSEPOCH 315532800LL
#define DOSENDTIME 4354775999LL
if (t < DOSEPOCH || t > DOSENDTIME)
t = DOSEPOCH;
if (lasttime != t) {
lasttime = t;
lastdtime = (((t / 2) % 30) << DT_2SECONDS_SHIFT)
+ (((t / 60) % 60) << DT_MINUTES_SHIFT)
+ (((t / 3600) % 24) << DT_HOURS_SHIFT);
/*
* If the number of days since 1970 is the same as the last
* time we did the computation then skip all this leap year
* and month stuff.
*/
days = t / (24 * 60 * 60);
if (days != lastday) {
lastday = days;
for (year = 1970;; year++) {
inc = year & 0x03 ? 365 : 366;
if (days < inc)
break;
days -= inc;
}
months = year & 0x03 ? regyear : leapyear;
for (month = 0; month < 12; month++) {
if (days < months[month])
break;
days -= months[month];
}
lastddate = ((days + 1) << DD_DAY_SHIFT)
+ ((month + 1) << DD_MONTH_SHIFT);
/*
* Remember dos's idea of time is relative to 1980.
* unix's is relative to 1970. If somehow we get a
* time before 1980 then don't give totally crazy
* results.
*/
if (year > 1980)
lastddate += (year - 1980) << DD_YEAR_SHIFT;
}
}
if (dtp != NULL)
*dtp = lastdtime;
if (dhp != NULL)
*dhp = (tsp->tv_sec & 1) * 100 + tsp->tv_nsec / 10000000;
*ddp = lastddate;
}
/*
* The number of seconds between Jan 1, 1970 and Jan 1, 1980. In that
* interval there were 8 regular years and 2 leap years.
*/
#define SECONDSTO1980 (((8 * 365) + (2 * 366)) * (24 * 60 * 60))
u_short lastdosdate;
uint32_t lastseconds;
/*
* Convert from dos' idea of time to unix'. This will probably only be
* called from the stat(), and fstat() system calls and so probably need
* not be too efficient.
*/
void
dos2unixtime(u_int dd, u_int dt, u_int dh, struct timespec *tsp)
{
uint32_t seconds;
uint32_t m, month;
uint32_t y, year;
uint32_t days;
const u_short *months;
if (dd == 0) {
/*
* Uninitialized field, return the epoch.
*/
tsp->tv_sec = 0;
tsp->tv_nsec = 0;
return;
}
seconds = ((dt & DT_2SECONDS_MASK) >> DT_2SECONDS_SHIFT) * 2
+ ((dt & DT_MINUTES_MASK) >> DT_MINUTES_SHIFT) * 60
+ ((dt & DT_HOURS_MASK) >> DT_HOURS_SHIFT) * 3600
+ dh / 100;
/*
* If the year, month, and day from the last conversion are the
* same then use the saved value.
*/
if (lastdosdate != dd) {
lastdosdate = dd;
days = 0;
year = (dd & DD_YEAR_MASK) >> DD_YEAR_SHIFT;
for (y = 0; y < year; y++)
days += y & 0x03 ? 365 : 366;
months = year & 0x03 ? regyear : leapyear;
/*
* Prevent going from 0 to 0xffffffff in the following
* loop.
*/
month = (dd & DD_MONTH_MASK) >> DD_MONTH_SHIFT;
if (month == 0) {
printf("dos2unixtime(): month value out of range (%u)\n",
month);
month = 1;
}
for (m = 0; m < month - 1; m++)
days += months[m];
days += ((dd & DD_DAY_MASK) >> DD_DAY_SHIFT) - 1;
lastseconds = (days * 24 * 60 * 60) + SECONDSTO1980;
}
tsp->tv_sec = seconds + lastseconds;
tsp->tv_nsec = (dh % 100) * 10000000;
}
static const u_char
unix2dos[256] = {
0, 0, 0, 0, 0, 0, 0, 0, /* 00-07 */
0, 0, 0, 0, 0, 0, 0, 0, /* 08-0f */
0, 0, 0, 0, 0, 0, 0, 0, /* 10-17 */
0, 0, 0, 0, 0, 0, 0, 0, /* 18-1f */
0, 0x21, 0, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
0x28, 0x29, 0, 0, 0, 0x2d, 0, 0, /* 28-2f */
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
0x38, 0x39, 0, 0, 0, 0, 0, 0, /* 38-3f */
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 40-47 */
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 48-4f */
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 50-57 */
0x58, 0x59, 0x5a, 0, 0, 0, 0x5e, 0x5f, /* 58-5f */
0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 60-67 */
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 68-6f */
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 70-77 */
0x58, 0x59, 0x5a, 0x7b, 0, 0x7d, 0x7e, 0, /* 78-7f */
0, 0, 0, 0, 0, 0, 0, 0, /* 80-87 */
0, 0, 0, 0, 0, 0, 0, 0, /* 88-8f */
0, 0, 0, 0, 0, 0, 0, 0, /* 90-97 */
0, 0, 0, 0, 0, 0, 0, 0, /* 98-9f */
0, 0xad, 0xbd, 0x9c, 0xcf, 0xbe, 0xdd, 0xf5, /* a0-a7 */
0xf9, 0xb8, 0xa6, 0xae, 0xaa, 0xf0, 0xa9, 0xee, /* a8-af */
0xf8, 0xf1, 0xfd, 0xfc, 0xef, 0xe6, 0xf4, 0xfa, /* b0-b7 */
0xf7, 0xfb, 0xa7, 0xaf, 0xac, 0xab, 0xf3, 0xa8, /* b8-bf */
0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* c0-c7 */
0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* c8-cf */
0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0x9e, /* d0-d7 */
0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0xe1, /* d8-df */
0xb7, 0xb5, 0xb6, 0xc7, 0x8e, 0x8f, 0x92, 0x80, /* e0-e7 */
0xd4, 0x90, 0xd2, 0xd3, 0xde, 0xd6, 0xd7, 0xd8, /* e8-ef */
0xd1, 0xa5, 0xe3, 0xe0, 0xe2, 0xe5, 0x99, 0xf6, /* f0-f7 */
0x9d, 0xeb, 0xe9, 0xea, 0x9a, 0xed, 0xe8, 0x98, /* f8-ff */
};
static const u_char
dos2unix[256] = {
0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 00-07 */
0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 08-0f */
0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 10-17 */
0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, /* 18-1f */
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x3f, /* 28-2f */
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 38-3f */
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, /* 40-47 */
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, /* 48-4f */
0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, /* 50-57 */
0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 58-5f */
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 60-67 */
0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 68-6f */
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 70-77 */
0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 78-7f */
0xc7, 0xfc, 0xe9, 0xe2, 0xe4, 0xe0, 0xe5, 0xe7, /* 80-87 */
0xea, 0xeb, 0xe8, 0xef, 0xee, 0xec, 0xc4, 0xc5, /* 88-8f */
0xc9, 0xe6, 0xc6, 0xf4, 0xf6, 0xf2, 0xfb, 0xf9, /* 90-97 */
0xff, 0xd6, 0xdc, 0xf8, 0xa3, 0xd8, 0xd7, 0x3f, /* 98-9f */
0xe1, 0xed, 0xf3, 0xfa, 0xf1, 0xd1, 0xaa, 0xba, /* a0-a7 */
0xbf, 0xae, 0xac, 0xbd, 0xbc, 0xa1, 0xab, 0xbb, /* a8-af */
0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0xc1, 0xc2, 0xc0, /* b0-b7 */
0xa9, 0x3f, 0x3f, 0x3f, 0x3f, 0xa2, 0xa5, 0x3f, /* b8-bf */
0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0xe3, 0xc3, /* c0-c7 */
0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0xa4, /* c8-cf */
0xf0, 0xd0, 0xca, 0xcb, 0xc8, 0x3f, 0xcd, 0xce, /* d0-d7 */
0xcf, 0x3f, 0x3f, 0x3f, 0x3f, 0xa6, 0xcc, 0x3f, /* d8-df */
0xd3, 0xdf, 0xd4, 0xd2, 0xf5, 0xd5, 0xb5, 0xfe, /* e0-e7 */
0xde, 0xda, 0xdb, 0xd9, 0xfd, 0xdd, 0xaf, 0x3f, /* e8-ef */
0xad, 0xb1, 0x3f, 0xbe, 0xb6, 0xa7, 0xf7, 0xb8, /* f0-f7 */
0xb0, 0xa8, 0xb7, 0xb9, 0xb3, 0xb2, 0x3f, 0x3f, /* f8-ff */
};
static const u_char
u2l[256] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 00-07 */
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 08-0f */
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 10-17 */
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 18-1f */
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, /* 20-27 */
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x3f, /* 28-2f */
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, /* 30-37 */
0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, /* 38-3f */
0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 40-47 */
0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 48-4f */
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 50-57 */
0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, /* 58-5f */
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, /* 60-67 */
0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, /* 68-6f */
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, /* 70-77 */
0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, /* 78-7f */
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 80-87 */
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 88-8f */
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, /* 90-97 */
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 98-9f */
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, /* a0-a7 */
0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, /* a8-af */
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, /* b0-b7 */
0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, /* b8-bf */
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* c0-c7 */
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* c8-cf */
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xd7, /* d0-d7 */
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xdf, /* d8-df */
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, /* e0-e7 */
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, /* e8-ef */
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, /* f0-f7 */
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* f8-ff */
};
/*
* DOS filenames are made of 2 parts, the name part and the extension part.
* The name part is 8 characters long and the extension part is 3
* characters long. They may contain trailing blanks if the name or
* extension are not long enough to fill their respective fields.
*/
/*
* Convert a DOS filename to a unix filename. And, return the number of
* characters in the resulting unix filename excluding the terminating
* null.
*/
int
dos2unixfn(u_char dn[11], u_char *un, int lower)
{
int i;
int thislong = 1;
u_char c;
/*
* If first char of the filename is SLOT_E5 (0x05), then the real
* first char of the filename should be 0xe5. But, they couldn't
* just have a 0xe5 mean 0xe5 because that is used to mean a freed
* directory slot. Another dos quirk.
*/
if (*dn == SLOT_E5)
c = dos2unix[0xe5];
else
c = dos2unix[*dn];
*un++ = lower ? u2l[c] : c;
dn++;
/*
* Copy the name portion into the unix filename string.
*/
for (i = 1; i < 8 && *dn != ' '; i++) {
c = dos2unix[*dn++];
*un++ = lower ? u2l[c] : c;
thislong++;
}
dn += 8 - i;
/*
* Now, if there is an extension then put in a period and copy in
* the extension.
*/
if (*dn != ' ') {
*un++ = '.';
thislong++;
for (i = 0; i < 3 && *dn != ' '; i++) {
c = dos2unix[*dn++];
*un++ = lower ? u2l[c] : c;
thislong++;
}
}
*un++ = 0;
return (thislong);
}
/*
* Convert a unix filename to a DOS filename according to Win95 rules.
* If applicable and gen is not 0, it is inserted into the converted
* filename as a generation number.
* Returns
* 0 if name couldn't be converted
* 1 if the converted name is the same as the original
* (no long filename entry necessary for Win95)
* 2 if conversion was successful
* 3 if conversion was successful and generation number was inserted
*/
int
unix2dosfn(u_char *un, u_char dn[11], int unlen, u_int gen)
{
int i, j, l;
int conv = 1;
u_char *cp, *dp, *dp1;
u_char gentext[6];
/*
* Fill the dos filename string with blanks. These are DOS's pad
* characters.
*/
for (i = 0; i < 11; i++)
dn[i] = ' ';
/*
* The filenames "." and ".." are handled specially, since they
* don't follow dos filename rules.
*/
if (un[0] == '.' && unlen == 1) {
dn[0] = '.';
return gen <= 1;
}
if (un[0] == '.' && un[1] == '.' && unlen == 2) {
dn[0] = '.';
dn[1] = '.';
return gen <= 1;
}
/*
* Filenames with only blanks and dots are not allowed!
*/
for (cp = un, i = unlen; --i >= 0; cp++)
if (*cp != ' ' && *cp != '.')
break;
if (i < 0)
return 0;
/*
* Now find the extension
* Note: dot as first char doesn't start extension
* and trailing dots and blanks are ignored
*/
dp = dp1 = 0;
for (cp = un + 1, i = unlen - 1; --i >= 0;) {
switch (*cp++) {
case '.':
if (!dp1)
dp1 = cp;
break;
case ' ':
break;
default:
if (dp1)
dp = dp1;
dp1 = 0;
break;
}
}
/*
* Now convert it
*/
if (dp) {
if (dp1)
l = dp1 - dp;
else
l = unlen - (dp - un);
for (i = 0, j = 8; i < l && j < 11; i++, j++) {
if (dp[i] != (dn[j] = unix2dos[dp[i]])
&& conv != 3)
conv = 2;
if (!dn[j]) {
conv = 3;
dn[j--] = ' ';
}
}
if (i < l)
conv = 3;
dp--;
} else {
for (dp = cp; *--dp == ' ' || *dp == '.';)
;
dp++;
}
/*
* Now convert the rest of the name
*/
for (i = j = 0; un < dp && j < 8; i++, j++, un++) {
if (*un != (dn[j] = unix2dos[*un])
&& conv != 3)
conv = 2;
if (!dn[j]) {
conv = 3;
dn[j--] = ' ';
}
}
if (un < dp)
conv = 3;
/*
* If we didn't have any chars in filename,
* generate a default
*/
if (!j)
dn[0] = '_';
/*
* The first character cannot be E5,
* because that means a deleted entry
*/
if (dn[0] == 0xe5)
dn[0] = SLOT_E5;
/*
* If there wasn't any char dropped,
* there is no place for generation numbers
*/
if (conv != 3) {
if (gen > 1)
return 0;
return conv;
}
/*
* Now insert the generation number into the filename part
*/
for (cp = gentext + sizeof(gentext); cp > gentext && gen; gen /= 10)
*--cp = gen % 10 + '0';
if (gen)
return 0;
for (i = 8; dn[--i] == ' ';)
;
if (gentext + sizeof(gentext) - cp + 1 > 8 - i)
i = 8 - (gentext + sizeof(gentext) - cp + 1);
dn[i++] = '~';
while (cp < gentext + sizeof(gentext))
dn[i++] = *cp++;
return 3;
}
/*
* Create a Win95 long name directory entry
* Note: assumes that the filename is valid,
* i.e. doesn't consist solely of blanks and dots
*/
int
unix2winfn(u_char *un, int unlen, struct winentry *wep, int cnt, int chksum)
{
u_int8_t *cp;
int i;
/*
* Drop trailing blanks and dots
*/
for (cp = un + unlen; *--cp == ' ' || *cp == '.'; unlen--)
;
un += (cnt - 1) * WIN_CHARS;
unlen -= (cnt - 1) * WIN_CHARS;
/*
* Initialize winentry to some useful default
*/
for (cp = (u_int8_t *)wep, i = sizeof(*wep); --i >= 0; *cp++ = 0xff)
;
wep->weCnt = cnt;
wep->weAttributes = ATTR_WIN95;
wep->weReserved1 = 0;
wep->weChksum = chksum;
wep->weReserved2 = 0;
/*
* Now convert the filename parts
*/
for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
if (--unlen < 0)
goto done;
*cp++ = *un++;
*cp++ = 0;
}
for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
if (--unlen < 0)
goto done;
*cp++ = *un++;
*cp++ = 0;
}
for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
if (--unlen < 0)
goto done;
*cp++ = *un++;
*cp++ = 0;
}
if (!unlen)
wep->weCnt |= WIN_LAST;
return unlen;
done:
*cp++ = 0;
*cp++ = 0;
wep->weCnt |= WIN_LAST;
return 0;
}
/*
* Compare our filename to the one in the Win95 entry
* Returns the checksum or -1 if no match
*/
int
winChkName(u_char *un, int unlen, struct winentry *wep, int chksum)
{
u_int8_t *cp;
int i;
/*
* First compare checksums
*/
if (wep->weCnt&WIN_LAST)
chksum = wep->weChksum;
else if (chksum != wep->weChksum)
chksum = -1;
if (chksum == -1)
return -1;
/*
* Offset of this entry
*/
i = ((wep->weCnt&WIN_CNT) - 1) * WIN_CHARS;
if ((unlen -= i) <= 0)
return -1;
un += i;
if ((wep->weCnt&WIN_LAST) && unlen > WIN_CHARS)
return -1;
/*
* Compare the name parts
*/
for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
if (--unlen < 0) {
if (!*cp++ && !*cp)
return chksum;
return -1;
}
if (u2l[*cp++] != u2l[*un++] || *cp++)
return -1;
}
for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
if (--unlen < 0) {
if (!*cp++ && !*cp)
return chksum;
return -1;
}
if (u2l[*cp++] != u2l[*un++] || *cp++)
return -1;
}
for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
if (--unlen < 0) {
if (!*cp++ && !*cp)
return chksum;
return -1;
}
if (u2l[*cp++] != u2l[*un++] || *cp++)
return -1;
}
return chksum;
}
/*
* Convert Win95 filename to dirbuf.
* Returns the checksum or -1 if impossible
*/
int
win2unixfn(struct winentry *wep, struct dirent *dp, int chksum)
{
u_int8_t *cp;
u_int8_t *np, *ep = dp->d_name + WIN_MAXLEN;
int i;
if ((wep->weCnt&WIN_CNT) > howmany(WIN_MAXLEN, WIN_CHARS)
|| !(wep->weCnt&WIN_CNT))
return -1;
/*
* First compare checksums
*/
if (wep->weCnt&WIN_LAST) {
chksum = wep->weChksum;
/*
* This works even though d_namlen is one byte!
*/
dp->d_namlen = (wep->weCnt&WIN_CNT) * WIN_CHARS;
} else if (chksum != wep->weChksum)
chksum = -1;
if (chksum == -1)
return -1;
/*
* Offset of this entry
*/
i = ((wep->weCnt&WIN_CNT) - 1) * WIN_CHARS;
np = (u_int8_t *)dp->d_name + i;
/*
* Convert the name parts
*/
for (cp = wep->wePart1, i = sizeof(wep->wePart1)/2; --i >= 0;) {
switch (*np++ = *cp++) {
case 0:
dp->d_namlen -= sizeof(wep->wePart2)/2
+ sizeof(wep->wePart3)/2 + i + 1;
return chksum;
case '/':
np[-1] = 0;
return -1;
}
/*
* The size comparison should result in the compiler
* optimizing the whole if away
*/
if (WIN_MAXLEN % WIN_CHARS < sizeof(wep->wePart1) / 2
&& np > ep) {
np[-1] = 0;
return -1;
}
if (*cp++)
return -1;
}
for (cp = wep->wePart2, i = sizeof(wep->wePart2)/2; --i >= 0;) {
switch (*np++ = *cp++) {
case 0:
dp->d_namlen -= sizeof(wep->wePart3)/2 + i + 1;
return chksum;
case '/':
np[-1] = 0;
return -1;
}
/*
* The size comparisons should be optimized away
*/
if (WIN_MAXLEN % WIN_CHARS >= sizeof(wep->wePart1) / 2
&& WIN_MAXLEN % WIN_CHARS < (sizeof(wep->wePart1) + sizeof(wep->wePart2)) / 2
&& np > ep) {
np[-1] = 0;
return -1;
}
if (*cp++)
return -1;
}
for (cp = wep->wePart3, i = sizeof(wep->wePart3)/2; --i >= 0;) {
switch (*np++ = *cp++) {
case 0:
dp->d_namlen -= i + 1;
return chksum;
case '/':
np[-1] = 0;
return -1;
}
/*
* See above
*/
if (WIN_MAXLEN % WIN_CHARS >= (sizeof(wep->wePart1) + sizeof(wep->wePart2)) / 2
&& np > ep) {
np[-1] = 0;
return -1;
}
if (*cp++)
return -1;
}
return chksum;
}
/*
* Compute the checksum of a DOS filename for Win95 use
*/
u_int8_t
winChksum(u_int8_t *name)
{
int i;
u_int8_t s;
for (s = 0, i = 11; --i >= 0; s += *name++)
s = (s << 7)|(s >> 1);
return s;
}
/*
* Determine the number of slots necessary for Win95 names
*/
int
winSlotCnt(u_char *un, int unlen)
{
for (un += unlen; unlen > 0; unlen--)
if (*--un != ' ' && *un != '.')
break;
if (unlen > WIN_MAXLEN)
return 0;
return howmany(unlen, WIN_CHARS);
}
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