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dosfs.c revision 1.17.6.1
      1  1.17.6.1       mrg /*	$NetBSD: dosfs.c,v 1.17.6.1 2012/02/18 07:35:35 mrg Exp $	*/
      2       1.1   thorpej 
      3       1.1   thorpej /*
      4       1.1   thorpej  * Copyright (c) 1996, 1998 Robert Nordier
      5       1.1   thorpej  * All rights reserved.
      6       1.1   thorpej  *
      7       1.1   thorpej  * Redistribution and use in source and binary forms, with or without
      8       1.1   thorpej  * modification, are permitted provided that the following conditions
      9       1.1   thorpej  * are met:
     10       1.1   thorpej  * 1. Redistributions of source code must retain the above copyright
     11       1.1   thorpej  *    notice, this list of conditions and the following disclaimer.
     12       1.1   thorpej  * 2. Redistributions in binary form must reproduce the above copyright
     13       1.1   thorpej  *    notice, this list of conditions and the following disclaimer in
     14       1.1   thorpej  *    the documentation and/or other materials provided with the
     15       1.1   thorpej  *    distribution.
     16       1.1   thorpej  *
     17       1.1   thorpej  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
     18       1.1   thorpej  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     19       1.1   thorpej  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     20       1.1   thorpej  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
     21       1.1   thorpej  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     22       1.1   thorpej  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     23       1.1   thorpej  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24       1.1   thorpej  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
     25       1.1   thorpej  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     26       1.1   thorpej  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
     27       1.1   thorpej  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28       1.1   thorpej  */
     29       1.1   thorpej 
     30       1.1   thorpej /*
     31       1.1   thorpej  * Readonly filesystem for Microsoft FAT12/FAT16/FAT32 filesystems,
     32       1.1   thorpej  * also supports VFAT.
     33       1.1   thorpej  */
     34       1.1   thorpej 
     35       1.1   thorpej /*
     36       1.1   thorpej  * XXX DOES NOT SUPPORT:
     37       1.1   thorpej  *
     38       1.1   thorpej  *	LIBSA_FS_SINGLECOMPONENT
     39       1.1   thorpej  */
     40       1.1   thorpej 
     41       1.1   thorpej #include <sys/param.h>
     42       1.1   thorpej 
     43       1.5     veego #include <fs/msdosfs/bpb.h>
     44       1.5     veego #include <fs/msdosfs/direntry.h>
     45       1.1   thorpej 
     46       1.1   thorpej #ifdef _STANDALONE
     47       1.1   thorpej #include <lib/libkern/libkern.h>
     48       1.1   thorpej #else
     49       1.1   thorpej #include <string.h>
     50       1.1   thorpej #include <stddef.h>
     51       1.1   thorpej #endif
     52       1.1   thorpej 
     53       1.1   thorpej #include "stand.h"
     54       1.1   thorpej #include "dosfs.h"
     55       1.1   thorpej 
     56       1.1   thorpej #define SECSIZ  512		/* sector size */
     57       1.1   thorpej #define SSHIFT    9		/* SECSIZ shift */
     58       1.1   thorpej #define DEPSEC   16		/* directory entries per sector */
     59       1.1   thorpej #define DSHIFT    4		/* DEPSEC shift */
     60       1.1   thorpej #define LOCLUS    2		/* lowest cluster number */
     61       1.1   thorpej 
     62       1.1   thorpej typedef union {
     63       1.1   thorpej 	struct direntry de;	/* standard directory entry */
     64       1.1   thorpej 	struct winentry xde;	/* extended directory entry */
     65       1.1   thorpej } DOS_DIR;
     66       1.1   thorpej 
     67       1.1   thorpej typedef struct {
     68       1.1   thorpej 	struct open_file *fd;	/* file descriptor */
     69       1.1   thorpej 	u_char *buf;		/* buffer */
     70       1.1   thorpej 	u_int   bufsec;		/* buffered sector */
     71       1.1   thorpej 	u_int   links;		/* active links to structure */
     72       1.1   thorpej 	u_int   spc;		/* sectors per cluster */
     73       1.1   thorpej 	u_int   bsize;		/* cluster size in bytes */
     74       1.1   thorpej 	u_int   bshift;		/* cluster conversion shift */
     75       1.1   thorpej 	u_int   dirents;	/* root directory entries */
     76       1.1   thorpej 	u_int   spf;		/* sectors per fat */
     77       1.1   thorpej 	u_int   rdcl;		/* root directory start cluster */
     78       1.1   thorpej 	u_int   lsnfat;		/* start of fat */
     79       1.1   thorpej 	u_int   lsndir;		/* start of root dir */
     80       1.1   thorpej 	u_int   lsndta;		/* start of data area */
     81       1.1   thorpej 	u_int   fatsz;		/* FAT entry size */
     82       1.1   thorpej 	u_int   xclus;		/* maximum cluster number */
     83       1.1   thorpej } DOS_FS;
     84       1.1   thorpej 
     85       1.1   thorpej typedef struct {
     86       1.1   thorpej 	DOS_FS *fs;		/* associated filesystem */
     87       1.1   thorpej 	struct direntry de;	/* directory entry */
     88       1.1   thorpej 	u_int   offset;		/* current offset */
     89       1.1   thorpej 	u_int   c;		/* last cluster read */
     90       1.1   thorpej } DOS_FILE;
     91       1.1   thorpej 
     92       1.1   thorpej /* Initial portion of DOS boot sector */
     93       1.1   thorpej typedef struct {
     94       1.1   thorpej 	u_char  jmp[3];		/* usually 80x86 'jmp' opcode */
     95       1.1   thorpej 	u_char  oem[8];		/* OEM name and version */
     96       1.1   thorpej 	struct byte_bpb710 bpb;	/* BPB */
     97       1.1   thorpej } DOS_BS;
     98       1.1   thorpej 
     99       1.1   thorpej /* Supply missing "." and ".." root directory entries */
    100       1.1   thorpej static const char *const dotstr[2] = {".", ".."};
    101       1.2   thorpej static const struct direntry dot[2] = {
    102       1.1   thorpej 	{".       ", "   ", ATTR_DIRECTORY,
    103       1.1   thorpej 		0, 0, {0, 0}, {0, 0}, {0, 0}, {0, 0},
    104       1.1   thorpej 		{0, 0}, {0x21, 0}, {0, 0}, {0, 0, 0, 0}},
    105       1.1   thorpej 
    106       1.1   thorpej 	{"..      ", "   ", ATTR_DIRECTORY,
    107       1.1   thorpej 		0, 0, {0, 0}, {0, 0}, {0, 0}, {0, 0},
    108       1.1   thorpej 		{0, 0}, {0x21, 0}, {0, 0}, {0, 0, 0, 0}}
    109       1.1   thorpej };
    110       1.1   thorpej 
    111       1.1   thorpej /* The usual conversion macros to avoid multiplication and division */
    112       1.1   thorpej #define bytsec(n)      ((n) >> SSHIFT)
    113       1.1   thorpej #define secbyt(s)      ((s) << SSHIFT)
    114       1.1   thorpej #define entsec(e)      ((e) >> DSHIFT)
    115       1.1   thorpej #define bytblk(fs, n)  ((n) >> (fs)->bshift)
    116       1.1   thorpej #define blkbyt(fs, b)  ((b) << (fs)->bshift)
    117       1.1   thorpej #define secblk(fs, s)  ((s) >> ((fs)->bshift - SSHIFT))
    118       1.1   thorpej #define blksec(fs, b)  ((b) << ((fs)->bshift - SSHIFT))
    119       1.1   thorpej 
    120       1.1   thorpej /* Convert cluster number to offset within filesystem */
    121       1.1   thorpej #define blkoff(fs, b) (secbyt((fs)->lsndta) + blkbyt(fs, (b) - LOCLUS))
    122       1.1   thorpej 
    123       1.1   thorpej /* Convert cluster number to logical sector number */
    124       1.1   thorpej #define blklsn(fs, b)  ((fs)->lsndta + blksec(fs, (b) - LOCLUS))
    125       1.1   thorpej 
    126       1.1   thorpej /* Convert cluster number to offset within FAT */
    127       1.1   thorpej #define fatoff(sz, c)  ((sz) == 12 ? (c) + ((c) >> 1) :  \
    128       1.1   thorpej                         (sz) == 16 ? (c) << 1 :          \
    129      1.12     isaki                         (c) << 2)
    130       1.1   thorpej 
    131       1.1   thorpej /* Does cluster number reference a valid data cluster? */
    132       1.1   thorpej #define okclus(fs, c)  ((c) >= LOCLUS && (c) <= (fs)->xclus)
    133       1.1   thorpej 
    134       1.1   thorpej /* Get start cluster from directory entry */
    135       1.8      fvdl #define stclus(sz, de)  ((sz) != 32 ? (u_int)getushort((de)->deStartCluster) : \
    136       1.1   thorpej                          ((u_int)getushort((de)->deHighClust) << 16) |  \
    137      1.12     isaki                          (u_int)getushort((de)->deStartCluster))
    138       1.1   thorpej 
    139       1.1   thorpej static int dosunmount(DOS_FS *);
    140       1.1   thorpej static int parsebs(DOS_FS *, DOS_BS *);
    141       1.2   thorpej static int namede(DOS_FS *, const char *, const struct direntry **);
    142       1.2   thorpej static int lookup(DOS_FS *, u_int, const char *, const struct direntry **);
    143       1.1   thorpej static void cp_xdnm(u_char *, struct winentry *);
    144       1.1   thorpej static void cp_sfn(u_char *, struct direntry *);
    145       1.1   thorpej static off_t fsize(DOS_FS *, struct direntry *);
    146       1.1   thorpej static int fatcnt(DOS_FS *, u_int);
    147       1.1   thorpej static int fatget(DOS_FS *, u_int *);
    148       1.1   thorpej static int fatend(u_int, u_int);
    149       1.1   thorpej static int ioread(DOS_FS *, u_int, void *, u_int);
    150       1.1   thorpej static int iobuf(DOS_FS *, u_int);
    151       1.1   thorpej static int ioget(struct open_file *, u_int, void *, u_int);
    152       1.1   thorpej 
    153      1.13       dsl #define strcasecmp(s1, s2) dos_strcasecmp(s1, s2)
    154      1.13       dsl static int
    155      1.13       dsl strcasecmp(const char *s1, const char *s2)
    156      1.13       dsl {
    157      1.13       dsl 	char c1, c2;
    158      1.13       dsl 	#define TO_UPPER(c) ((c) >= 'a' && (c) <= 'z' ? (c) - ('a' - 'A') : (c))
    159      1.13       dsl 	for (;;) {
    160      1.13       dsl 		c1 = *s1++;
    161      1.13       dsl 		c2 = *s2++;
    162      1.13       dsl 		if (TO_UPPER(c1) != TO_UPPER(c2))
    163      1.13       dsl 			return 1;
    164      1.13       dsl 		if (c1 == 0)
    165      1.13       dsl 			return 0;
    166      1.13       dsl 	}
    167      1.13       dsl 	#undef TO_UPPER
    168      1.13       dsl }
    169      1.13       dsl 
    170       1.1   thorpej /*
    171       1.1   thorpej  * Mount DOS filesystem
    172       1.1   thorpej  */
    173       1.1   thorpej static int
    174      1.12     isaki dos_mount(DOS_FS *fs, struct open_file *fd)
    175       1.1   thorpej {
    176       1.1   thorpej 	int     err;
    177       1.1   thorpej 
    178      1.14  christos 	(void)memset(fs, 0, sizeof(DOS_FS));
    179       1.1   thorpej 	fs->fd = fd;
    180       1.1   thorpej 	if ((err = !(fs->buf = alloc(SECSIZ)) ? errno : 0) ||
    181       1.1   thorpej 	    (err = ioget(fs->fd, 0, fs->buf, 1)) ||
    182      1.12     isaki 	    (err = parsebs(fs, (DOS_BS *)fs->buf))) {
    183       1.1   thorpej 		(void) dosunmount(fs);
    184      1.12     isaki 		return err;
    185       1.1   thorpej 	}
    186       1.1   thorpej 	return 0;
    187       1.1   thorpej }
    188       1.1   thorpej 
    189       1.4      matt #ifndef LIBSA_NO_FS_CLOSE
    190       1.1   thorpej /*
    191       1.1   thorpej  * Unmount mounted filesystem
    192       1.1   thorpej  */
    193       1.1   thorpej static int
    194      1.12     isaki dos_unmount(DOS_FS *fs)
    195       1.1   thorpej {
    196       1.1   thorpej 	int     err;
    197       1.1   thorpej 
    198       1.1   thorpej 	if (fs->links)
    199      1.12     isaki 		return EBUSY;
    200       1.1   thorpej 	if ((err = dosunmount(fs)))
    201      1.12     isaki 		return err;
    202       1.1   thorpej 	return 0;
    203       1.1   thorpej }
    204       1.4      matt #endif
    205       1.1   thorpej 
    206       1.1   thorpej /*
    207       1.1   thorpej  * Common code shared by dos_mount() and dos_unmount()
    208       1.1   thorpej  */
    209       1.1   thorpej static int
    210      1.12     isaki dosunmount(DOS_FS *fs)
    211       1.1   thorpej {
    212       1.1   thorpej 	if (fs->buf)
    213      1.10  christos 		dealloc(fs->buf, SECSIZ);
    214      1.10  christos 	dealloc(fs, sizeof(DOS_FS));
    215      1.12     isaki 	return 0;
    216       1.1   thorpej }
    217       1.1   thorpej 
    218       1.1   thorpej /*
    219       1.1   thorpej  * Open DOS file
    220       1.1   thorpej  */
    221      1.17     joerg __compactcall int
    222       1.7       dsl dosfs_open(const char *path, struct open_file *fd)
    223       1.1   thorpej {
    224       1.2   thorpej 	const struct direntry *de;
    225       1.1   thorpej 	DOS_FILE *f;
    226       1.1   thorpej 	DOS_FS *fs;
    227       1.1   thorpej 	u_int   size, clus;
    228       1.1   thorpej 	int     err = 0;
    229       1.1   thorpej 
    230       1.1   thorpej 	/* Allocate mount structure, associate with open */
    231       1.1   thorpej 	fs = alloc(sizeof(DOS_FS));
    232       1.1   thorpej 
    233       1.1   thorpej 	if ((err = dos_mount(fs, fd)))
    234       1.1   thorpej 		goto out;
    235       1.1   thorpej 
    236       1.1   thorpej 	if ((err = namede(fs, path, &de)))
    237       1.1   thorpej 		goto out;
    238       1.1   thorpej 
    239       1.1   thorpej 	clus = stclus(fs->fatsz, de);
    240       1.1   thorpej 	size = getulong(de->deFileSize);
    241       1.1   thorpej 
    242       1.1   thorpej 	if ((!(de->deAttributes & ATTR_DIRECTORY) && (!clus != !size)) ||
    243       1.1   thorpej 	    ((de->deAttributes & ATTR_DIRECTORY) && size) ||
    244       1.1   thorpej 	    (clus && !okclus(fs, clus))) {
    245       1.1   thorpej 		err = EINVAL;
    246       1.1   thorpej 		goto out;
    247       1.1   thorpej 	}
    248      1.11    dogcow 
    249       1.1   thorpej 	f = alloc(sizeof(DOS_FILE));
    250      1.11    dogcow #ifdef BOOTXX
    251      1.11    dogcow 	/* due to __internal_memset_ causing all sorts of register spillage
    252      1.11    dogcow 	   (and being completely unoptimized for zeroing small amounts of
    253      1.11    dogcow 	   memory), if we hand-initialize the remaining members of f to zero,
    254      1.11    dogcow 	   the code size drops 68 bytes. This makes no sense, admittedly. */
    255      1.11    dogcow 	f->offset = 0;
    256      1.11    dogcow 	f->c = 0;
    257      1.11    dogcow #else
    258      1.14  christos 	(void)memset(f, 0, sizeof(DOS_FILE));
    259      1.11    dogcow #endif
    260       1.1   thorpej 	f->fs = fs;
    261       1.1   thorpej 	fs->links++;
    262       1.1   thorpej 	f->de = *de;
    263      1.12     isaki 	fd->f_fsdata = (void *)f;
    264      1.16        ad 	fsmod = "msdos";
    265       1.1   thorpej 
    266       1.1   thorpej out:
    267      1.12     isaki 	return err;
    268       1.1   thorpej }
    269       1.1   thorpej 
    270       1.1   thorpej /*
    271       1.1   thorpej  * Read from file
    272       1.1   thorpej  */
    273      1.17     joerg __compactcall int
    274      1.12     isaki dosfs_read(struct open_file *fd, void *vbuf, size_t nbyte, size_t *resid)
    275       1.1   thorpej {
    276       1.1   thorpej 	off_t   size;
    277       1.3      matt 	u_int8_t *buf = vbuf;
    278       1.1   thorpej 	u_int   nb, off, clus, c, cnt, n;
    279      1.12     isaki 	DOS_FILE *f = (DOS_FILE *)fd->f_fsdata;
    280       1.1   thorpej 	int     err = 0;
    281       1.1   thorpej 
    282       1.1   thorpej 	nb = (u_int) nbyte;
    283       1.1   thorpej 	if ((size = fsize(f->fs, &f->de)) == -1)
    284       1.1   thorpej 		return EINVAL;
    285       1.1   thorpej 	if (nb > (n = size - f->offset))
    286       1.1   thorpej 		nb = n;
    287       1.1   thorpej 	off = f->offset;
    288       1.1   thorpej 	if ((clus = stclus(f->fs->fatsz, &f->de)))
    289       1.1   thorpej 		off &= f->fs->bsize - 1;
    290       1.1   thorpej 	c = f->c;
    291       1.1   thorpej 	cnt = nb;
    292       1.1   thorpej 	while (cnt) {
    293       1.1   thorpej 		n = 0;
    294       1.1   thorpej 		if (!c) {
    295       1.1   thorpej 			if ((c = clus))
    296       1.1   thorpej 				n = bytblk(f->fs, f->offset);
    297      1.12     isaki 		} else if (!off) {
    298       1.1   thorpej 			n++;
    299      1.12     isaki 		}
    300       1.1   thorpej 		while (n--) {
    301       1.1   thorpej 			if ((err = fatget(f->fs, &c)))
    302       1.1   thorpej 				goto out;
    303       1.1   thorpej 			if (!okclus(f->fs, c)) {
    304       1.1   thorpej 				err = EINVAL;
    305       1.1   thorpej 				goto out;
    306       1.1   thorpej 			}
    307       1.1   thorpej 		}
    308       1.1   thorpej 		if (!clus || (n = f->fs->bsize - off) > cnt)
    309       1.1   thorpej 			n = cnt;
    310       1.1   thorpej 		if ((err = ioread(f->fs, (c ? blkoff(f->fs, c) :
    311       1.1   thorpej 				secbyt(f->fs->lsndir)) + off,
    312       1.1   thorpej 			    buf, n)))
    313       1.1   thorpej 			goto out;
    314       1.1   thorpej 		f->offset += n;
    315       1.1   thorpej 		f->c = c;
    316       1.1   thorpej 		off = 0;
    317       1.1   thorpej 		buf += n;
    318       1.1   thorpej 		cnt -= n;
    319       1.1   thorpej 	}
    320       1.1   thorpej out:
    321       1.1   thorpej 	if (resid)
    322       1.1   thorpej 		*resid = nbyte - nb + cnt;
    323      1.12     isaki 	return err;
    324       1.1   thorpej }
    325       1.1   thorpej 
    326       1.1   thorpej #ifndef LIBSA_NO_FS_WRITE
    327       1.1   thorpej /*
    328       1.1   thorpej  * Not implemented.
    329       1.1   thorpej  */
    330      1.17     joerg __compactcall int
    331       1.1   thorpej dosfs_write(struct open_file *fd, void *start, size_t size, size_t *resid)
    332       1.1   thorpej {
    333       1.1   thorpej 
    334      1.12     isaki 	return EROFS;
    335       1.1   thorpej }
    336       1.1   thorpej #endif /* !LIBSA_NO_FS_WRITE */
    337       1.1   thorpej 
    338       1.1   thorpej #ifndef LIBSA_NO_FS_SEEK
    339       1.1   thorpej /*
    340       1.1   thorpej  * Reposition within file
    341       1.1   thorpej  */
    342      1.17     joerg __compactcall off_t
    343      1.12     isaki dosfs_seek(struct open_file *fd, off_t offset, int whence)
    344       1.1   thorpej {
    345       1.1   thorpej 	off_t   off;
    346       1.1   thorpej 	u_int   size;
    347      1.12     isaki 	DOS_FILE *f = (DOS_FILE *)fd->f_fsdata;
    348       1.1   thorpej 
    349       1.1   thorpej 	size = getulong(f->de.deFileSize);
    350       1.1   thorpej 	switch (whence) {
    351       1.1   thorpej 	case SEEK_SET:
    352       1.1   thorpej 		off = 0;
    353       1.1   thorpej 		break;
    354       1.1   thorpej 	case SEEK_CUR:
    355       1.1   thorpej 		off = f->offset;
    356       1.1   thorpej 		break;
    357       1.1   thorpej 	case SEEK_END:
    358       1.1   thorpej 		off = size;
    359       1.1   thorpej 		break;
    360       1.1   thorpej 	default:
    361      1.12     isaki 		return -1;
    362       1.1   thorpej 	}
    363       1.1   thorpej 	off += offset;
    364       1.1   thorpej 	if (off < 0 || off > size)
    365      1.12     isaki 		return -1;
    366       1.1   thorpej 	f->offset = (u_int) off;
    367       1.1   thorpej 	f->c = 0;
    368      1.12     isaki 	return off;
    369       1.1   thorpej }
    370       1.1   thorpej #endif /* !LIBSA_NO_FS_SEEK */
    371       1.1   thorpej 
    372       1.1   thorpej #ifndef LIBSA_NO_FS_CLOSE
    373       1.1   thorpej /*
    374       1.1   thorpej  * Close open file
    375       1.1   thorpej  */
    376      1.17     joerg __compactcall int
    377      1.12     isaki dosfs_close(struct open_file *fd)
    378       1.1   thorpej {
    379      1.12     isaki 	DOS_FILE *f = (DOS_FILE *)fd->f_fsdata;
    380       1.1   thorpej 	DOS_FS *fs = f->fs;
    381       1.1   thorpej 
    382       1.1   thorpej 	f->fs->links--;
    383      1.10  christos 	dealloc(f, sizeof(DOS_FILE));
    384       1.1   thorpej 	dos_unmount(fs);
    385       1.1   thorpej 	return 0;
    386       1.1   thorpej }
    387       1.1   thorpej #endif /* !LIBSA_NO_FS_CLOSE */
    388       1.1   thorpej 
    389       1.1   thorpej /*
    390       1.1   thorpej  * Return some stat information on a file.
    391       1.1   thorpej  */
    392      1.17     joerg __compactcall int
    393      1.12     isaki dosfs_stat(struct open_file *fd, struct stat *sb)
    394       1.1   thorpej {
    395      1.12     isaki 	DOS_FILE *f = (DOS_FILE *)fd->f_fsdata;
    396       1.1   thorpej 
    397       1.1   thorpej 	/* only important stuff */
    398       1.1   thorpej 	sb->st_mode = (f->de.deAttributes & ATTR_DIRECTORY) ?
    399       1.1   thorpej 	    (S_IFDIR | 0555) : (S_IFREG | 0444);
    400       1.1   thorpej 	sb->st_nlink = 1;
    401       1.1   thorpej 	sb->st_uid = 0;
    402       1.1   thorpej 	sb->st_gid = 0;
    403       1.1   thorpej 	if ((sb->st_size = fsize(f->fs, &f->de)) == -1)
    404       1.1   thorpej 		return EINVAL;
    405      1.12     isaki 	return 0;
    406       1.1   thorpej }
    407       1.1   thorpej 
    408  1.17.6.1       mrg #if defined(LIBSA_ENABLE_LS_OP)
    409  1.17.6.1       mrg __compactcall void
    410  1.17.6.1       mrg dosfs_ls(struct open_file *f, const char *pattern)
    411  1.17.6.1       mrg {
    412  1.17.6.1       mrg 	printf("Currently ls command is unsupported by dosfs\n");
    413  1.17.6.1       mrg 	return;
    414  1.17.6.1       mrg }
    415  1.17.6.1       mrg #endif
    416  1.17.6.1       mrg 
    417       1.1   thorpej /*
    418       1.1   thorpej  * Parse DOS boot sector
    419       1.1   thorpej  */
    420       1.1   thorpej static int
    421      1.12     isaki parsebs(DOS_FS *fs, DOS_BS *bs)
    422       1.1   thorpej {
    423       1.1   thorpej 	u_int   sc;
    424       1.1   thorpej 
    425       1.1   thorpej 	if ((bs->jmp[0] != 0x69 &&
    426       1.1   thorpej 		bs->jmp[0] != 0xe9 &&
    427       1.1   thorpej 		(bs->jmp[0] != 0xeb || bs->jmp[2] != 0x90)) ||
    428       1.1   thorpej 	    bs->bpb.bpbMedia < 0xf0)
    429       1.1   thorpej 		return EINVAL;
    430       1.1   thorpej 	if (getushort(bs->bpb.bpbBytesPerSec) != SECSIZ)
    431       1.1   thorpej 		return EINVAL;
    432       1.1   thorpej 	if (!(fs->spc = bs->bpb.bpbSecPerClust) || fs->spc & (fs->spc - 1))
    433       1.1   thorpej 		return EINVAL;
    434       1.1   thorpej 	fs->bsize = secbyt(fs->spc);
    435       1.1   thorpej 	fs->bshift = ffs(fs->bsize) - 1;
    436       1.1   thorpej 	if ((fs->spf = getushort(bs->bpb.bpbFATsecs))) {
    437       1.1   thorpej 		if (bs->bpb.bpbFATs != 2)
    438       1.1   thorpej 			return EINVAL;
    439       1.1   thorpej 		if (!(fs->dirents = getushort(bs->bpb.bpbRootDirEnts)))
    440       1.1   thorpej 			return EINVAL;
    441       1.1   thorpej 	} else {
    442       1.1   thorpej 		if (!(fs->spf = getulong(bs->bpb.bpbBigFATsecs)))
    443       1.1   thorpej 			return EINVAL;
    444       1.1   thorpej 		if (!bs->bpb.bpbFATs || bs->bpb.bpbFATs > 16)
    445       1.1   thorpej 			return EINVAL;
    446       1.1   thorpej 		if ((fs->rdcl = getulong(bs->bpb.bpbRootClust)) < LOCLUS)
    447       1.1   thorpej 			return EINVAL;
    448       1.1   thorpej 	}
    449       1.1   thorpej 	if (!(fs->lsnfat = getushort(bs->bpb.bpbResSectors)))
    450       1.1   thorpej 		return EINVAL;
    451       1.1   thorpej 	fs->lsndir = fs->lsnfat + fs->spf * bs->bpb.bpbFATs;
    452       1.1   thorpej 	fs->lsndta = fs->lsndir + entsec(fs->dirents);
    453       1.1   thorpej 	if (!(sc = getushort(bs->bpb.bpbSectors)) &&
    454       1.1   thorpej 	    !(sc = getulong(bs->bpb.bpbHugeSectors)))
    455       1.1   thorpej 		return EINVAL;
    456       1.1   thorpej 	if (fs->lsndta > sc)
    457       1.1   thorpej 		return EINVAL;
    458       1.1   thorpej 	if ((fs->xclus = secblk(fs, sc - fs->lsndta) + 1) < LOCLUS)
    459       1.1   thorpej 		return EINVAL;
    460       1.1   thorpej 	fs->fatsz = fs->dirents ? fs->xclus < 0xff6 ? 12 : 16 : 32;
    461       1.1   thorpej 	sc = (secbyt(fs->spf) << 1) / (fs->fatsz >> 2) - 1;
    462       1.1   thorpej 	if (fs->xclus > sc)
    463       1.1   thorpej 		fs->xclus = sc;
    464       1.1   thorpej 	return 0;
    465       1.1   thorpej }
    466       1.1   thorpej 
    467       1.1   thorpej /*
    468       1.1   thorpej  * Return directory entry from path
    469       1.1   thorpej  */
    470       1.1   thorpej static int
    471      1.12     isaki namede(DOS_FS *fs, const char *path, const struct direntry **dep)
    472       1.1   thorpej {
    473       1.1   thorpej 	char    name[256];
    474       1.2   thorpej 	const struct direntry *de;
    475       1.1   thorpej 	char   *s;
    476       1.1   thorpej 	size_t  n;
    477       1.1   thorpej 	int     err;
    478       1.1   thorpej 
    479       1.1   thorpej 	err = 0;
    480       1.1   thorpej 	de = dot;
    481       1.1   thorpej 	if (*path == '/')
    482       1.1   thorpej 		path++;
    483       1.1   thorpej 	while (*path) {
    484       1.1   thorpej 		if (!(s = strchr(path, '/')))
    485       1.1   thorpej 			s = strchr(path, 0);
    486       1.1   thorpej 		if ((n = s - path) > 255)
    487       1.1   thorpej 			return ENAMETOOLONG;
    488       1.1   thorpej 		memcpy(name, path, n);
    489       1.1   thorpej 		name[n] = 0;
    490       1.1   thorpej 		path = s;
    491       1.1   thorpej 		if (!(de->deAttributes & ATTR_DIRECTORY))
    492       1.1   thorpej 			return ENOTDIR;
    493       1.1   thorpej 		if ((err = lookup(fs, stclus(fs->fatsz, de), name, &de)))
    494       1.1   thorpej 			return err;
    495       1.1   thorpej 		if (*path == '/')
    496       1.1   thorpej 			path++;
    497       1.1   thorpej 	}
    498       1.1   thorpej 	*dep = de;
    499       1.1   thorpej 	return 0;
    500       1.1   thorpej }
    501       1.1   thorpej 
    502       1.1   thorpej /*
    503       1.1   thorpej  * Lookup path segment
    504       1.1   thorpej  */
    505       1.1   thorpej static int
    506      1.12     isaki lookup(DOS_FS *fs, u_int clus, const char *name, const struct direntry **dep)
    507       1.1   thorpej {
    508       1.6       scw 	static DOS_DIR *dir = NULL;
    509       1.1   thorpej 	u_char  lfn[261];
    510       1.1   thorpej 	u_char  sfn[13];
    511       1.1   thorpej 	u_int   nsec, lsec, xdn, chk, sec, ent, x;
    512       1.1   thorpej 	int     err = 0, ok, i;
    513       1.1   thorpej 
    514       1.1   thorpej 	if (!clus)
    515       1.1   thorpej 		for (ent = 0; ent < 2; ent++)
    516       1.1   thorpej 			if (!strcasecmp(name, dotstr[ent])) {
    517       1.1   thorpej 				*dep = dot + ent;
    518       1.1   thorpej 				return 0;
    519       1.1   thorpej 			}
    520       1.1   thorpej 
    521       1.6       scw 	if (dir == NULL) {
    522       1.6       scw 		dir = alloc(sizeof(DOS_DIR) * DEPSEC);
    523       1.6       scw 		if (dir == NULL)
    524      1.12     isaki 			return ENOMEM;
    525       1.6       scw 	}
    526       1.1   thorpej 
    527       1.1   thorpej 	if (!clus && fs->fatsz == 32)
    528       1.1   thorpej 		clus = fs->rdcl;
    529       1.1   thorpej 	nsec = !clus ? entsec(fs->dirents) : fs->spc;
    530       1.1   thorpej 	lsec = 0;
    531       1.1   thorpej 	xdn = chk = 0;
    532       1.1   thorpej 	for (;;) {
    533       1.1   thorpej 		if (!clus && !lsec)
    534       1.1   thorpej 			lsec = fs->lsndir;
    535       1.1   thorpej 		else if (okclus(fs, clus))
    536       1.1   thorpej 			lsec = blklsn(fs, clus);
    537       1.1   thorpej 		else {
    538       1.1   thorpej 			err = EINVAL;
    539       1.1   thorpej 			goto out;
    540       1.1   thorpej 		}
    541       1.1   thorpej 		for (sec = 0; sec < nsec; sec++) {
    542       1.1   thorpej 			if ((err = ioget(fs->fd, lsec + sec, dir, 1)))
    543       1.1   thorpej 				goto out;
    544       1.1   thorpej 			for (ent = 0; ent < DEPSEC; ent++) {
    545       1.1   thorpej 				if (!*dir[ent].de.deName) {
    546       1.1   thorpej 					err = ENOENT;
    547       1.1   thorpej 					goto out;
    548       1.1   thorpej 				}
    549       1.1   thorpej 				if (*dir[ent].de.deName != 0xe5) {
    550       1.1   thorpej 					if (dir[ent].de.deAttributes ==
    551       1.1   thorpej 					    ATTR_WIN95) {
    552       1.1   thorpej 						x = dir[ent].xde.weCnt;
    553       1.1   thorpej 						if (x & WIN_LAST ||
    554       1.1   thorpej 						    (x + 1 == xdn &&
    555       1.1   thorpej 						     dir[ent].xde.weChksum ==
    556       1.1   thorpej 						     chk)) {
    557       1.1   thorpej 							if (x & WIN_LAST) {
    558       1.1   thorpej 								chk = dir[ent].xde.weChksum;
    559       1.1   thorpej 								x &= WIN_CNT;
    560       1.1   thorpej 							}
    561       1.1   thorpej 							if (x >= 1 && x <= 20) {
    562       1.1   thorpej 								cp_xdnm(lfn, &dir[ent].xde);
    563       1.1   thorpej 								xdn = x;
    564       1.1   thorpej 								continue;
    565       1.1   thorpej 							}
    566       1.1   thorpej 						}
    567       1.1   thorpej 					} else if (!(dir[ent].de.deAttributes &
    568       1.1   thorpej 						     ATTR_VOLUME)) {
    569       1.1   thorpej 						if ((ok = xdn == 1)) {
    570       1.1   thorpej 							for (x = 0, i = 0;
    571       1.1   thorpej 							     i < 11; i++)
    572       1.1   thorpej 								x = ((((x & 1) << 7) | (x >> 1)) +
    573       1.1   thorpej 								    dir[ent].de.deName[i]) & 0xff;
    574       1.1   thorpej 							ok = chk == x &&
    575      1.12     isaki 							    !strcasecmp(name, (const char *)lfn);
    576       1.1   thorpej 						}
    577       1.1   thorpej 						if (!ok) {
    578       1.1   thorpej 							cp_sfn(sfn, &dir[ent].de);
    579      1.12     isaki 							ok = !strcasecmp(name, (const char *)sfn);
    580       1.1   thorpej 						}
    581       1.1   thorpej 						if (ok) {
    582       1.1   thorpej 							*dep = &dir[ent].de;
    583       1.6       scw 							goto out2;
    584       1.1   thorpej 						}
    585       1.1   thorpej 					}
    586       1.1   thorpej 				}
    587       1.1   thorpej 				xdn = 0;
    588       1.1   thorpej 			}
    589       1.1   thorpej 		}
    590       1.1   thorpej 		if (!clus)
    591       1.1   thorpej 			break;
    592       1.1   thorpej 		if ((err = fatget(fs, &clus)))
    593       1.1   thorpej 			goto out;
    594       1.1   thorpej 		if (fatend(fs->fatsz, clus))
    595       1.1   thorpej 			break;
    596       1.1   thorpej 	}
    597       1.1   thorpej 	err = ENOENT;
    598       1.1   thorpej  out:
    599      1.10  christos 	dealloc(dir, sizeof(DOS_DIR) * DEPSEC);
    600       1.6       scw 	dir = NULL;
    601       1.6       scw  out2:
    602      1.12     isaki 	return err;
    603       1.1   thorpej }
    604       1.1   thorpej 
    605       1.1   thorpej /*
    606       1.1   thorpej  * Copy name from extended directory entry
    607       1.1   thorpej  */
    608       1.1   thorpej static void
    609      1.12     isaki cp_xdnm(u_char *lfn, struct winentry *xde)
    610       1.1   thorpej {
    611       1.1   thorpej 	static const struct {
    612       1.1   thorpej 		u_int   off;
    613       1.1   thorpej 		u_int   dim;
    614       1.1   thorpej 	} ix[3] = {
    615       1.1   thorpej 		{ offsetof(struct winentry, wePart1),
    616       1.1   thorpej 		    sizeof(xde->wePart1) / 2 },
    617       1.1   thorpej 		{ offsetof(struct winentry, wePart2),
    618       1.1   thorpej 		    sizeof(xde->wePart2) / 2 },
    619       1.1   thorpej 		{ offsetof(struct winentry, wePart3),
    620       1.1   thorpej 		    sizeof(xde->wePart3) / 2 }
    621       1.1   thorpej 	};
    622       1.1   thorpej 	u_char *p;
    623       1.1   thorpej 	u_int   n, x, c;
    624       1.1   thorpej 
    625       1.1   thorpej 	lfn += 13 * ((xde->weCnt & WIN_CNT) - 1);
    626       1.1   thorpej 	for (n = 0; n < 3; n++)
    627      1.12     isaki 		for (p = (u_char *)xde + ix[n].off, x = ix[n].dim; x;
    628       1.1   thorpej 		    p += 2, x--) {
    629       1.1   thorpej 			if ((c = getushort(p)) && (c < 32 || c > 127))
    630       1.1   thorpej 				c = '?';
    631       1.1   thorpej 			if (!(*lfn++ = c))
    632       1.1   thorpej 				return;
    633       1.1   thorpej 		}
    634       1.1   thorpej 	if (xde->weCnt & WIN_LAST)
    635       1.1   thorpej 		*lfn = 0;
    636       1.1   thorpej }
    637       1.1   thorpej 
    638       1.1   thorpej /*
    639       1.1   thorpej  * Copy short filename
    640       1.1   thorpej  */
    641       1.1   thorpej static void
    642      1.12     isaki cp_sfn(u_char *sfn, struct direntry *de)
    643       1.1   thorpej {
    644       1.1   thorpej 	u_char *p;
    645       1.1   thorpej 	int     j, i;
    646       1.1   thorpej 
    647       1.1   thorpej 	p = sfn;
    648       1.1   thorpej 	if (*de->deName != ' ') {
    649       1.1   thorpej 		for (j = 7; de->deName[j] == ' '; j--);
    650       1.1   thorpej 		for (i = 0; i <= j; i++)
    651       1.1   thorpej 			*p++ = de->deName[i];
    652       1.1   thorpej 		if (*de->deExtension != ' ') {
    653       1.1   thorpej 			*p++ = '.';
    654       1.1   thorpej 			for (j = 2; de->deExtension[j] == ' '; j--);
    655       1.1   thorpej 			for (i = 0; i <= j; i++)
    656       1.1   thorpej 				*p++ = de->deExtension[i];
    657       1.1   thorpej 		}
    658       1.1   thorpej 	}
    659       1.1   thorpej 	*p = 0;
    660       1.1   thorpej 	if (*sfn == 5)
    661       1.1   thorpej 		*sfn = 0xe5;
    662       1.1   thorpej }
    663       1.1   thorpej 
    664       1.1   thorpej /*
    665       1.1   thorpej  * Return size of file in bytes
    666       1.1   thorpej  */
    667       1.1   thorpej static  off_t
    668      1.12     isaki fsize(DOS_FS *fs, struct direntry *de)
    669       1.1   thorpej {
    670       1.1   thorpej 	u_long  size;
    671       1.1   thorpej 	u_int   c;
    672       1.1   thorpej 	int     n;
    673       1.1   thorpej 
    674       1.1   thorpej 	if (!(size = getulong(de->deFileSize)) &&
    675       1.1   thorpej 	    de->deAttributes & ATTR_DIRECTORY) {
    676      1.12     isaki 		if (!(c = getushort(de->deStartCluster))) {
    677       1.1   thorpej 			size = fs->dirents * sizeof(struct direntry);
    678      1.12     isaki 		} else {
    679       1.1   thorpej 			if ((n = fatcnt(fs, c)) == -1)
    680       1.1   thorpej 				return n;
    681       1.1   thorpej 			size = blkbyt(fs, n);
    682       1.1   thorpej 		}
    683       1.1   thorpej 	}
    684       1.1   thorpej 	return size;
    685       1.1   thorpej }
    686       1.1   thorpej 
    687       1.1   thorpej /*
    688       1.1   thorpej  * Count number of clusters in chain
    689       1.1   thorpej  */
    690       1.1   thorpej static int
    691      1.12     isaki fatcnt(DOS_FS *fs, u_int c)
    692       1.1   thorpej {
    693       1.1   thorpej 	int     n;
    694       1.1   thorpej 
    695       1.1   thorpej 	for (n = 0; okclus(fs, c); n++)
    696       1.1   thorpej 		if (fatget(fs, &c))
    697       1.1   thorpej 			return -1;
    698       1.1   thorpej 	return fatend(fs->fatsz, c) ? n : -1;
    699       1.1   thorpej }
    700       1.1   thorpej 
    701       1.1   thorpej /*
    702       1.1   thorpej  * Get next cluster in cluster chain
    703       1.1   thorpej  */
    704       1.1   thorpej static int
    705      1.12     isaki fatget(DOS_FS *fs, u_int *c)
    706       1.1   thorpej {
    707       1.1   thorpej 	u_char  buf[4];
    708       1.1   thorpej 	u_int   x;
    709       1.1   thorpej 	int     err;
    710       1.1   thorpej 
    711       1.1   thorpej 	err = ioread(fs, secbyt(fs->lsnfat) + fatoff(fs->fatsz, *c), buf,
    712       1.1   thorpej 	    fs->fatsz != 32 ? 2 : 4);
    713       1.1   thorpej 	if (err)
    714       1.1   thorpej 		return err;
    715       1.1   thorpej 	x = fs->fatsz != 32 ? getushort(buf) : getulong(buf);
    716       1.1   thorpej 	*c = fs->fatsz == 12 ? *c & 1 ? x >> 4 : x & 0xfff : x;
    717       1.1   thorpej 	return 0;
    718       1.1   thorpej }
    719       1.1   thorpej 
    720       1.1   thorpej /*
    721       1.1   thorpej  * Is cluster an end-of-chain marker?
    722       1.1   thorpej  */
    723       1.1   thorpej static int
    724       1.1   thorpej fatend(u_int sz, u_int c)
    725       1.1   thorpej {
    726       1.1   thorpej 	return c > (sz == 12 ? 0xff7U : sz == 16 ? 0xfff7U : 0xffffff7);
    727       1.1   thorpej }
    728       1.1   thorpej 
    729       1.1   thorpej /*
    730       1.1   thorpej  * Offset-based I/O primitive
    731       1.1   thorpej  */
    732       1.1   thorpej static int
    733      1.12     isaki ioread(DOS_FS *fs, u_int offset, void *buf, u_int nbyte)
    734       1.1   thorpej {
    735       1.1   thorpej 	char   *s;
    736       1.1   thorpej 	u_int   off, n;
    737       1.1   thorpej 	int     err;
    738       1.1   thorpej 
    739       1.1   thorpej 	s = buf;
    740       1.1   thorpej 	if ((off = offset & (SECSIZ - 1))) {
    741       1.1   thorpej 		offset -= off;
    742       1.1   thorpej 		if ((err = iobuf(fs, bytsec(offset))))
    743       1.1   thorpej 			return err;
    744       1.1   thorpej 		offset += SECSIZ;
    745       1.1   thorpej 		if ((n = SECSIZ - off) > nbyte)
    746       1.1   thorpej 			n = nbyte;
    747       1.1   thorpej 		memcpy(s, fs->buf + off, n);
    748       1.1   thorpej 		s += n;
    749       1.1   thorpej 		nbyte -= n;
    750       1.1   thorpej 	}
    751       1.1   thorpej 	n = nbyte & (SECSIZ - 1);
    752       1.1   thorpej 	if (nbyte -= n) {
    753       1.1   thorpej 		if ((err = ioget(fs->fd, bytsec(offset), s, bytsec(nbyte))))
    754       1.1   thorpej 			return err;
    755       1.1   thorpej 		offset += nbyte;
    756       1.1   thorpej 		s += nbyte;
    757       1.1   thorpej 	}
    758       1.1   thorpej 	if (n) {
    759       1.1   thorpej 		if ((err = iobuf(fs, bytsec(offset))))
    760       1.1   thorpej 			return err;
    761       1.1   thorpej 		memcpy(s, fs->buf, n);
    762       1.1   thorpej 	}
    763       1.1   thorpej 	return 0;
    764       1.1   thorpej }
    765       1.1   thorpej 
    766       1.1   thorpej /*
    767       1.1   thorpej  * Buffered sector-based I/O primitive
    768       1.1   thorpej  */
    769       1.1   thorpej static int
    770      1.12     isaki iobuf(DOS_FS *fs, u_int lsec)
    771       1.1   thorpej {
    772       1.1   thorpej 	int     err;
    773       1.1   thorpej 
    774       1.1   thorpej 	if (fs->bufsec != lsec) {
    775       1.1   thorpej 		if ((err = ioget(fs->fd, lsec, fs->buf, 1)))
    776       1.1   thorpej 			return err;
    777       1.1   thorpej 		fs->bufsec = lsec;
    778       1.1   thorpej 	}
    779       1.1   thorpej 	return 0;
    780       1.1   thorpej }
    781       1.1   thorpej 
    782       1.1   thorpej /*
    783       1.1   thorpej  * Sector-based I/O primitive
    784       1.1   thorpej  */
    785       1.1   thorpej static int
    786      1.12     isaki ioget(struct open_file *fd, u_int lsec, void *buf, u_int nsec)
    787       1.1   thorpej {
    788       1.1   thorpej 	size_t rsize;
    789       1.1   thorpej 	int err;
    790       1.1   thorpej 
    791       1.1   thorpej #ifndef LIBSA_NO_TWIDDLE
    792       1.1   thorpej 	twiddle();
    793       1.1   thorpej #endif
    794       1.1   thorpej 	err = DEV_STRATEGY(fd->f_dev)(fd->f_devdata, F_READ, lsec,
    795       1.1   thorpej 	    secbyt(nsec), buf, &rsize);
    796      1.12     isaki 	return err;
    797       1.1   thorpej }
    798