dosfs.c revision 38451
138451Smsmith/* 238451Smsmith * Copyright (c) 1996, 1998 Robert Nordier 338451Smsmith * All rights reserved. 438451Smsmith * 538451Smsmith * Redistribution and use in source and binary forms, with or without 638451Smsmith * modification, are permitted provided that the following conditions 738451Smsmith * are met: 838451Smsmith * 1. Redistributions of source code must retain the above copyright 938451Smsmith * notice, this list of conditions and the following disclaimer. 1038451Smsmith * 2. Redistributions in binary form must reproduce the above copyright 1138451Smsmith * notice, this list of conditions and the following disclaimer in 1238451Smsmith * the documentation and/or other materials provided with the 1338451Smsmith * distribution. 1438451Smsmith * 1538451Smsmith * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS 1638451Smsmith * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 1738451Smsmith * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1838451Smsmith * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY 1938451Smsmith * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2038451Smsmith * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 2138451Smsmith * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 2238451Smsmith * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 2338451Smsmith * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 2438451Smsmith * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 2538451Smsmith * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2638451Smsmith */ 2738451Smsmith 2838451Smsmith/* 2938451Smsmith * Readonly filesystem for Microsoft FAT12/FAT16/FAT32 filesystems, 3038451Smsmith * also supports VFAT. 3138451Smsmith */ 3238451Smsmith 3338451Smsmith#include <sys/types.h> 3438451Smsmith#include <string.h> 3538451Smsmith#include <stddef.h> 3638451Smsmith 3738451Smsmith#include "stand.h" 3838451Smsmith 3938451Smsmith#if 0 4038451Smsmith#include <unistd.h> 4138451Smsmith#include <fcntl.h> 4238451Smsmith#include <stdlib.h> 4338451Smsmith#include <stdio.h> 4438451Smsmith#include <errno.h> 4538451Smsmith#endif 4638451Smsmith 4738451Smsmith#include "dosfs.h" 4838451Smsmith 4938451Smsmith 5038451Smsmithstatic int dos_open(char *path, struct open_file *fd); 5138451Smsmithstatic int dos_close(struct open_file *fd); 5238451Smsmithstatic int dos_read(struct open_file *fd, void *buf, size_t size, size_t *resid); 5338451Smsmithstatic off_t dos_seek(struct open_file *fd, off_t offset, int whence); 5438451Smsmithstatic int dos_stat(struct open_file *fd, struct stat *sb); 5538451Smsmith 5638451Smsmithstruct fs_ops dos_fsops = { 5738451Smsmith "dosfs", dos_open, dos_close, dos_read, null_write, dos_seek, dos_stat 5838451Smsmith}; 5938451Smsmith 6038451Smsmith#define SECSIZ 512 /* sector size */ 6138451Smsmith#define SSHIFT 9 /* SECSIZ shift */ 6238451Smsmith#define DEPSEC 16 /* directory entries per sector */ 6338451Smsmith#define DSHIFT 4 /* DEPSEC shift */ 6438451Smsmith#define LOCLUS 2 /* lowest cluster number */ 6538451Smsmith 6638451Smsmith/* DOS "BIOS Parameter Block" */ 6738451Smsmithtypedef struct { 6838451Smsmith u_char secsiz[2]; /* sector size */ 6938451Smsmith u_char spc; /* sectors per cluster */ 7038451Smsmith u_char ressec[2]; /* reserved sectors */ 7138451Smsmith u_char fats; /* FATs */ 7238451Smsmith u_char dirents[2]; /* root directory entries */ 7338451Smsmith u_char secs[2]; /* total sectors */ 7438451Smsmith u_char media; /* media descriptor */ 7538451Smsmith u_char spf[2]; /* sectors per FAT */ 7638451Smsmith u_char spt[2]; /* sectors per track */ 7738451Smsmith u_char heads[2]; /* drive heads */ 7838451Smsmith u_char hidsec[4]; /* hidden sectors */ 7938451Smsmith u_char lsecs[4]; /* huge sectors */ 8038451Smsmith u_char lspf[4]; /* huge sectors per FAT */ 8138451Smsmith u_char xflg[2]; /* flags */ 8238451Smsmith u_char vers[2]; /* filesystem version */ 8338451Smsmith u_char rdcl[4]; /* root directory start cluster */ 8438451Smsmith u_char infs[2]; /* filesystem info sector */ 8538451Smsmith u_char bkbs[2]; /* backup boot sector */ 8638451Smsmith} DOS_BPB; 8738451Smsmith 8838451Smsmith/* Initial portion of DOS boot sector */ 8938451Smsmithtypedef struct { 9038451Smsmith u_char jmp[3]; /* usually 80x86 'jmp' opcode */ 9138451Smsmith u_char oem[8]; /* OEM name and version */ 9238451Smsmith DOS_BPB bpb; /* BPB */ 9338451Smsmith} DOS_BS; 9438451Smsmith 9538451Smsmith/* Supply missing "." and ".." root directory entries */ 9638451Smsmithstatic const char *const dotstr[2] = {".", ".."}; 9738451Smsmithstatic DOS_DE dot[2] = { 9838451Smsmith {". ", " ", FA_DIR, {0, 0, {0, 0}, {0, 0}, {0, 0}, {0, 0}}, 9938451Smsmith {0, 0}, {0x21, 0}, {0, 0}, {0, 0, 0, 0}}, 10038451Smsmith {".. ", " ", FA_DIR, {0, 0, {0, 0}, {0, 0}, {0, 0}, {0, 0}}, 10138451Smsmith {0, 0}, {0x21, 0}, {0, 0}, {0, 0, 0, 0}} 10238451Smsmith}; 10338451Smsmith 10438451Smsmith/* The usual conversion macros to avoid multiplication and division */ 10538451Smsmith#define bytsec(n) ((n) >> SSHIFT) 10638451Smsmith#define secbyt(s) ((s) << SSHIFT) 10738451Smsmith#define entsec(e) ((e) >> DSHIFT) 10838451Smsmith#define bytblk(fs, n) ((n) >> (fs)->bshift) 10938451Smsmith#define blkbyt(fs, b) ((b) << (fs)->bshift) 11038451Smsmith#define secblk(fs, s) ((s) >> ((fs)->bshift - SSHIFT)) 11138451Smsmith#define blksec(fs, b) ((b) << ((fs)->bshift - SSHIFT)) 11238451Smsmith 11338451Smsmith/* Convert cluster number to offset within filesystem */ 11438451Smsmith#define blkoff(fs, b) (secbyt((fs)->lsndta) + blkbyt(fs, (b) - LOCLUS)) 11538451Smsmith 11638451Smsmith/* Convert cluster number to logical sector number */ 11738451Smsmith#define blklsn(fs, b) ((fs)->lsndta + blksec(fs, (b) - LOCLUS)) 11838451Smsmith 11938451Smsmith/* Convert cluster number to offset within FAT */ 12038451Smsmith#define fatoff(sz, c) ((sz) == 12 ? (c) + ((c) >> 1) : \ 12138451Smsmith (sz) == 16 ? (c) << 1 : \ 12238451Smsmith (c) << 2) 12338451Smsmith 12438451Smsmith/* Does cluster number reference a valid data cluster? */ 12538451Smsmith#define okclus(fs, c) ((c) >= LOCLUS && (c) <= (fs)->xclus) 12638451Smsmith 12738451Smsmith/* Get start cluster from directory entry */ 12838451Smsmith#define stclus(sz, de) ((sz) != 32 ? cv2((de)->clus) : \ 12938451Smsmith ((u_int)cv2((de)->dex.h_clus) << 16) | \ 13038451Smsmith cv2((de)->clus)) 13138451Smsmith 13238451Smsmithstatic int dosunmount(DOS_FS *); 13338451Smsmithstatic int parsebs(DOS_FS *, DOS_BS *); 13438451Smsmithstatic int namede(DOS_FS *, const char *, DOS_DE **); 13538451Smsmithstatic int lookup(DOS_FS *, u_int, const char *, DOS_DE **); 13638451Smsmithstatic void cp_xdnm(u_char *, DOS_XDE *); 13738451Smsmithstatic void cp_sfn(u_char *, DOS_DE *); 13838451Smsmithstatic int fatget(DOS_FS *, u_int *); 13938451Smsmithstatic int fatend(u_int, u_int); 14038451Smsmithstatic int ioread(DOS_FS *, u_int, void *, u_int); 14138451Smsmithstatic int iobuf(DOS_FS *, u_int); 14238451Smsmithstatic int ioget(struct open_file *, u_int, void *, u_int); 14338451Smsmith 14438451Smsmith/* 14538451Smsmith * Mount DOS filesystem 14638451Smsmith */ 14738451Smsmithstatic int 14838451Smsmithdos_mount(DOS_FS *fs, struct open_file *fd) 14938451Smsmith{ 15038451Smsmith int err; 15138451Smsmith 15238451Smsmith bzero(fs, sizeof(DOS_FS)); 15338451Smsmith fs->fd = fd; 15438451Smsmith if ((err = !(fs->buf = alloc(SECSIZ)) ? errno : 0) || 15538451Smsmith (err = ioget(fs->fd, 0, fs->buf, 1)) || 15638451Smsmith (err = parsebs(fs, (DOS_BS *)fs->buf))) { 15738451Smsmith (void)dosunmount(fs); 15838451Smsmith return(err); 15938451Smsmith } 16038451Smsmith return 0; 16138451Smsmith} 16238451Smsmith 16338451Smsmith/* 16438451Smsmith * Unmount mounted filesystem 16538451Smsmith */ 16638451Smsmithstatic int 16738451Smsmithdos_unmount(DOS_FS *fs) 16838451Smsmith{ 16938451Smsmith int err; 17038451Smsmith 17138451Smsmith if (fs->links) 17238451Smsmith return(EBUSY); 17338451Smsmith if ((err = dosunmount(fs))) 17438451Smsmith return(err); 17538451Smsmith return 0; 17638451Smsmith} 17738451Smsmith 17838451Smsmith/* 17938451Smsmith * Common code shared by dos_mount() and dos_unmount() 18038451Smsmith */ 18138451Smsmithstatic int 18238451Smsmithdosunmount(DOS_FS *fs) 18338451Smsmith{ 18438451Smsmith if (fs->buf) 18538451Smsmith free(fs->buf, 0); 18638451Smsmith free(fs, 0); 18738451Smsmith return(0); 18838451Smsmith} 18938451Smsmith 19038451Smsmith/* 19138451Smsmith * Open DOS file 19238451Smsmith */ 19338451Smsmithstatic int 19438451Smsmithdos_open(char *path, struct open_file *fd) 19538451Smsmith{ 19638451Smsmith DOS_DE *de; 19738451Smsmith DOS_FILE *f; 19838451Smsmith DOS_FS *fs; 19938451Smsmith u_int size, clus; 20038451Smsmith int err = 0; 20138451Smsmith 20238451Smsmith /* Allocate mount structure, associate with open */ 20338451Smsmith fs = alloc(sizeof(DOS_FS)); 20438451Smsmith 20538451Smsmith if ((err = dos_mount(fs, fd))) 20638451Smsmith goto out; 20738451Smsmith 20838451Smsmith if ((err = namede(fs, path, &de))) 20938451Smsmith goto out; 21038451Smsmith 21138451Smsmith /* XXX we need to be able to open directories */ 21238451Smsmith if (de->attr & FA_DIR) { 21338451Smsmith err = EISDIR; 21438451Smsmith goto out; 21538451Smsmith } 21638451Smsmith clus = stclus(fs->fatsz, de); 21738451Smsmith size = cv4(de->size); 21838451Smsmith if (!clus ^ !size || (clus && !okclus(fs, clus))) { 21938451Smsmith err = EINVAL; 22038451Smsmith goto out; 22138451Smsmith } 22238451Smsmith f = alloc(sizeof(DOS_FILE)); 22338451Smsmith bzero(f, sizeof(DOS_FILE)); 22438451Smsmith f->fs = fs; 22538451Smsmith fs->links++; 22638451Smsmith f->de = *de; 22738451Smsmith fd->f_fsdata = (void *)f; 22838451Smsmith 22938451Smsmith out: 23038451Smsmith return(err); 23138451Smsmith} 23238451Smsmith 23338451Smsmith/* 23438451Smsmith * Read from file 23538451Smsmith */ 23638451Smsmithstatic int 23738451Smsmithdos_read(struct open_file *fd, void *buf, size_t nbyte, size_t *resid) 23838451Smsmith{ 23938451Smsmith u_int nb, off, clus, c, cnt, n; 24038451Smsmith DOS_FILE *f = (DOS_FILE *)fd->f_fsdata; 24138451Smsmith int err = 0; 24238451Smsmith 24338451Smsmith nb = (u_int)nbyte; 24438451Smsmith if (nb > (n = cv4(f->de.size) - f->offset)) 24538451Smsmith nb = n; 24638451Smsmith off = f->offset; 24738451Smsmith if ((clus = stclus(f->fs->fatsz, &f->de))) 24838451Smsmith off &= f->fs->bsize - 1; 24938451Smsmith c = f->c; 25038451Smsmith cnt = nb; 25138451Smsmith while (cnt) { 25238451Smsmith n = 0; 25338451Smsmith if (!c) { 25438451Smsmith if ((c = clus)) 25538451Smsmith n = bytblk(f->fs, f->offset); 25638451Smsmith } else if (!off) 25738451Smsmith n++; 25838451Smsmith while (n--) { 25938451Smsmith if ((err = fatget(f->fs, &c))) 26038451Smsmith goto out; 26138451Smsmith if (!okclus(f->fs, c)) { 26238451Smsmith err = EINVAL; 26338451Smsmith goto out; 26438451Smsmith } 26538451Smsmith } 26638451Smsmith if (!clus || (n = f->fs->bsize - off) > cnt) 26738451Smsmith n = cnt; 26838451Smsmith if ((err = ioread(f->fs, blkoff(f->fs, c) + off, buf, n))) 26938451Smsmith goto out; 27038451Smsmith f->offset += n; 27138451Smsmith f->c = c; 27238451Smsmith off = 0; 27338451Smsmith buf += n; 27438451Smsmith cnt -= n; 27538451Smsmith } 27638451Smsmith out: 27738451Smsmith if (resid) 27838451Smsmith *resid = cnt; 27938451Smsmith return(err); 28038451Smsmith} 28138451Smsmith 28238451Smsmith/* 28338451Smsmith * Reposition within file 28438451Smsmith */ 28538451Smsmithstatic off_t 28638451Smsmithdos_seek(struct open_file *fd, off_t offset, int whence) 28738451Smsmith{ 28838451Smsmith off_t off; 28938451Smsmith u_int size; 29038451Smsmith DOS_FILE *f = (DOS_FILE *)fd->f_fsdata; 29138451Smsmith 29238451Smsmith size = cv4(f->de.size); 29338451Smsmith switch (whence) { 29438451Smsmith case SEEK_SET: 29538451Smsmith off = 0; 29638451Smsmith break; 29738451Smsmith case SEEK_CUR: 29838451Smsmith off = f->offset; 29938451Smsmith break; 30038451Smsmith case SEEK_END: 30138451Smsmith off = size; 30238451Smsmith break; 30338451Smsmith default: 30438451Smsmith return(-1); 30538451Smsmith } 30638451Smsmith off += offset; 30738451Smsmith if (off < 0 || off > size) 30838451Smsmith return(-1); 30938451Smsmith f->offset = (u_int)off; 31038451Smsmith f->c = 0; 31138451Smsmith return(off); 31238451Smsmith} 31338451Smsmith 31438451Smsmith/* 31538451Smsmith * Close open file 31638451Smsmith */ 31738451Smsmithstatic int 31838451Smsmithdos_close(struct open_file *fd) 31938451Smsmith{ 32038451Smsmith DOS_FILE *f = (DOS_FILE *)fd->f_fsdata; 32138451Smsmith DOS_FS *fs = f->fs; 32238451Smsmith 32338451Smsmith f->fs->links--; 32438451Smsmith free(f, 0); 32538451Smsmith dos_unmount(fs); 32638451Smsmith return 0; 32738451Smsmith} 32838451Smsmith 32938451Smsmith/* 33038451Smsmith * Return some stat information on a file. 33138451Smsmith */ 33238451Smsmithstatic int 33338451Smsmithdos_stat(struct open_file *fd, struct stat *sb) 33438451Smsmith{ 33538451Smsmith DOS_FILE *f = (DOS_FILE *)fd->f_fsdata; 33638451Smsmith 33738451Smsmith /* only important stuff */ 33838451Smsmith sb->st_mode = 0444; 33938451Smsmith sb->st_nlink = 1; 34038451Smsmith sb->st_uid = 0; 34138451Smsmith sb->st_gid = 0; 34238451Smsmith sb->st_size = cv4(f->de.size); 34338451Smsmith return (0); 34438451Smsmith} 34538451Smsmith 34638451Smsmith/* 34738451Smsmith * Parse DOS boot sector 34838451Smsmith */ 34938451Smsmithstatic int 35038451Smsmithparsebs(DOS_FS *fs, DOS_BS *bs) 35138451Smsmith{ 35238451Smsmith u_int sc; 35338451Smsmith 35438451Smsmith if ((bs->jmp[0] != 0x69 && 35538451Smsmith bs->jmp[0] != 0xe9 && 35638451Smsmith (bs->jmp[0] != 0xeb || bs->jmp[2] != 0x90)) || 35738451Smsmith bs->bpb.media < 0xf0) 35838451Smsmith return EINVAL; 35938451Smsmith if (cv2(bs->bpb.secsiz) != SECSIZ) 36038451Smsmith return EINVAL; 36138451Smsmith if (!(fs->spc = bs->bpb.spc) || fs->spc & (fs->spc - 1)) 36238451Smsmith return EINVAL; 36338451Smsmith fs->bsize = secbyt(fs->spc); 36438451Smsmith fs->bshift = ffs(fs->bsize) - 1; 36538451Smsmith if ((fs->spf = cv2(bs->bpb.spf))) { 36638451Smsmith if (bs->bpb.fats != 2) 36738451Smsmith return EINVAL; 36838451Smsmith if (!(fs->dirents = cv2(bs->bpb.dirents))) 36938451Smsmith return EINVAL; 37038451Smsmith } else { 37138451Smsmith if (!(fs->spf = cv4(bs->bpb.lspf))) 37238451Smsmith return EINVAL; 37338451Smsmith if (!bs->bpb.fats || bs->bpb.fats > 16) 37438451Smsmith return EINVAL; 37538451Smsmith if ((fs->rdcl = cv4(bs->bpb.rdcl)) < LOCLUS) 37638451Smsmith return EINVAL; 37738451Smsmith } 37838451Smsmith if (!(fs->lsnfat = cv2(bs->bpb.ressec))) 37938451Smsmith return EINVAL; 38038451Smsmith fs->lsndir = fs->lsnfat + fs->spf * bs->bpb.fats; 38138451Smsmith fs->lsndta = fs->lsndir + entsec(fs->dirents); 38238451Smsmith if (!(sc = cv2(bs->bpb.secs)) && !(sc = cv4(bs->bpb.lsecs))) 38338451Smsmith return EINVAL; 38438451Smsmith if (fs->lsndta > sc) 38538451Smsmith return EINVAL; 38638451Smsmith if ((fs->xclus = secblk(fs, sc - fs->lsndta) + 1) < LOCLUS) 38738451Smsmith return EINVAL; 38838451Smsmith fs->fatsz = fs->dirents ? fs->xclus < 0xff6 ? 12 : 16 : 32; 38938451Smsmith sc = (secbyt(fs->spf) << 1) / (fs->fatsz >> 2) - 1; 39038451Smsmith if (fs->xclus > sc) 39138451Smsmith fs->xclus = sc; 39238451Smsmith return 0; 39338451Smsmith} 39438451Smsmith 39538451Smsmith/* 39638451Smsmith * Return directory entry from path 39738451Smsmith */ 39838451Smsmithstatic int 39938451Smsmithnamede(DOS_FS *fs, const char *path, DOS_DE **dep) 40038451Smsmith{ 40138451Smsmith char name[256]; 40238451Smsmith DOS_DE *de; 40338451Smsmith char *s; 40438451Smsmith size_t n; 40538451Smsmith int err; 40638451Smsmith 40738451Smsmith err = 0; 40838451Smsmith de = dot; 40938451Smsmith if (*path == '/') 41038451Smsmith path++; 41138451Smsmith while (*path) { 41238451Smsmith if (!(s = strchr(path, '/'))) 41338451Smsmith s = strchr(path, 0); 41438451Smsmith if ((n = s - path) > 255) 41538451Smsmith return ENAMETOOLONG; 41638451Smsmith memcpy(name, path, n); 41738451Smsmith name[n] = 0; 41838451Smsmith path = s; 41938451Smsmith if (!(de->attr & FA_DIR)) 42038451Smsmith return ENOTDIR; 42138451Smsmith if ((err = lookup(fs, stclus(fs->fatsz, de), name, &de))) 42238451Smsmith return err; 42338451Smsmith if (*path == '/') 42438451Smsmith path++; 42538451Smsmith } 42638451Smsmith *dep = de; 42738451Smsmith return 0; 42838451Smsmith} 42938451Smsmith 43038451Smsmith/* 43138451Smsmith * Lookup path segment 43238451Smsmith */ 43338451Smsmithstatic int 43438451Smsmithlookup(DOS_FS *fs, u_int clus, const char *name, DOS_DE **dep) 43538451Smsmith{ 43638451Smsmith static DOS_DIR dir[DEPSEC]; 43738451Smsmith u_char lfn[261]; 43838451Smsmith u_char sfn[13]; 43938451Smsmith u_int nsec, lsec, xdn, chk, sec, ent, x; 44038451Smsmith int err, ok, i; 44138451Smsmith 44238451Smsmith if (!clus) 44338451Smsmith for (ent = 0; ent < 2; ent++) 44438451Smsmith if (!strcasecmp(name, dotstr[ent])) { 44538451Smsmith *dep = dot + ent; 44638451Smsmith return 0; 44738451Smsmith } 44838451Smsmith if (!clus && fs->fatsz == 32) 44938451Smsmith clus = fs->rdcl; 45038451Smsmith nsec = !clus ? entsec(fs->dirents) : fs->spc; 45138451Smsmith lsec = 0; 45238451Smsmith xdn = chk = 0; 45338451Smsmith for (;;) { 45438451Smsmith if (!clus && !lsec) 45538451Smsmith lsec = fs->lsndir; 45638451Smsmith else if (okclus(fs, clus)) 45738451Smsmith lsec = blklsn(fs, clus); 45838451Smsmith else 45938451Smsmith return EINVAL; 46038451Smsmith for (sec = 0; sec < nsec; sec++) { 46138451Smsmith if ((err = ioget(fs->fd, lsec + sec, dir, 1))) 46238451Smsmith return err; 46338451Smsmith for (ent = 0; ent < DEPSEC; ent++) { 46438451Smsmith if (!*dir[ent].de.name) 46538451Smsmith return ENOENT; 46638451Smsmith if (*dir[ent].de.name != 0xe5) 46738451Smsmith if ((dir[ent].de.attr & FA_MASK) == FA_XDE) { 46838451Smsmith x = dir[ent].xde.seq; 46938451Smsmith if (x & 0x40 || (x + 1 == xdn && 47038451Smsmith dir[ent].xde.chk == chk)) { 47138451Smsmith if (x & 0x40) { 47238451Smsmith chk = dir[ent].xde.chk; 47338451Smsmith x &= ~0x40; 47438451Smsmith } 47538451Smsmith if (x >= 1 && x <= 20) { 47638451Smsmith cp_xdnm(lfn, &dir[ent].xde); 47738451Smsmith xdn = x; 47838451Smsmith continue; 47938451Smsmith } 48038451Smsmith } 48138451Smsmith } else if (!(dir[ent].de.attr & FA_LABEL)) { 48238451Smsmith if ((ok = xdn == 1)) { 48338451Smsmith for (x = 0, i = 0; i < 11; i++) 48438451Smsmith x = ((((x & 1) << 7) | (x >> 1)) + 48538451Smsmith dir[ent].de.name[i]) & 0xff; 48638451Smsmith ok = chk == x && 48738451Smsmith !strcasecmp(name, (const char *)lfn); 48838451Smsmith } 48938451Smsmith if (!ok) { 49038451Smsmith cp_sfn(sfn, &dir[ent].de); 49138451Smsmith ok = !strcasecmp(name, (const char *)sfn); 49238451Smsmith } 49338451Smsmith if (ok) { 49438451Smsmith *dep = &dir[ent].de; 49538451Smsmith return 0; 49638451Smsmith } 49738451Smsmith } 49838451Smsmith xdn = 0; 49938451Smsmith } 50038451Smsmith } 50138451Smsmith if (!clus) 50238451Smsmith break; 50338451Smsmith if ((err = fatget(fs, &clus))) 50438451Smsmith return err; 50538451Smsmith if (fatend(fs->fatsz, clus)) 50638451Smsmith break; 50738451Smsmith } 50838451Smsmith return ENOENT; 50938451Smsmith} 51038451Smsmith 51138451Smsmith/* 51238451Smsmith * Copy name from extended directory entry 51338451Smsmith */ 51438451Smsmithstatic void 51538451Smsmithcp_xdnm(u_char *lfn, DOS_XDE *xde) 51638451Smsmith{ 51738451Smsmith static struct { 51838451Smsmith u_int off; 51938451Smsmith u_int dim; 52038451Smsmith } ix[3] = { 52138451Smsmith {offsetof(DOS_XDE, name1), sizeof(xde->name1) / 2}, 52238451Smsmith {offsetof(DOS_XDE, name2), sizeof(xde->name2) / 2}, 52338451Smsmith {offsetof(DOS_XDE, name3), sizeof(xde->name3) / 2} 52438451Smsmith }; 52538451Smsmith u_char *p; 52638451Smsmith u_int n, x, c; 52738451Smsmith 52838451Smsmith lfn += 13 * ((xde->seq & ~0x40) - 1); 52938451Smsmith for (n = 0; n < 3; n++) 53038451Smsmith for (p = (u_char *)xde + ix[n].off, x = ix[n].dim; x; 53138451Smsmith p += 2, x--) { 53238451Smsmith if ((c = cv2(p)) && (c < 32 || c > 127)) 53338451Smsmith c = '?'; 53438451Smsmith if (!(*lfn++ = c)) 53538451Smsmith return; 53638451Smsmith } 53738451Smsmith if (xde->seq & 0x40) 53838451Smsmith *lfn = 0; 53938451Smsmith} 54038451Smsmith 54138451Smsmith/* 54238451Smsmith * Copy short filename 54338451Smsmith */ 54438451Smsmithstatic void 54538451Smsmithcp_sfn(u_char *sfn, DOS_DE *de) 54638451Smsmith{ 54738451Smsmith u_char *p; 54838451Smsmith int j, i; 54938451Smsmith 55038451Smsmith p = sfn; 55138451Smsmith if (*de->name != ' ') { 55238451Smsmith for (j = 7; de->name[j] == ' '; j--); 55338451Smsmith for (i = 0; i <= j; i++) 55438451Smsmith *p++ = de->name[i]; 55538451Smsmith if (*de->ext != ' ') { 55638451Smsmith *p++ = '.'; 55738451Smsmith for (j = 2; de->ext[j] == ' '; j--); 55838451Smsmith for (i = 0; i <= j; i++) 55938451Smsmith *p++ = de->ext[i]; 56038451Smsmith } 56138451Smsmith } 56238451Smsmith *p = 0; 56338451Smsmith if (*sfn == 5) 56438451Smsmith *sfn = 0xe5; 56538451Smsmith} 56638451Smsmith 56738451Smsmith/* 56838451Smsmith * Get next cluster in cluster chain 56938451Smsmith */ 57038451Smsmithstatic int 57138451Smsmithfatget(DOS_FS *fs, u_int *c) 57238451Smsmith{ 57338451Smsmith u_char buf[4]; 57438451Smsmith u_int x; 57538451Smsmith int err; 57638451Smsmith 57738451Smsmith err = ioread(fs, secbyt(fs->lsnfat) + fatoff(fs->fatsz, *c), buf, 57838451Smsmith fs->fatsz != 32 ? 2 : 4); 57938451Smsmith if (err) 58038451Smsmith return err; 58138451Smsmith x = fs->fatsz != 32 ? cv2(buf) : cv4(buf); 58238451Smsmith *c = fs->fatsz == 12 ? *c & 1 ? x >> 4 : x & 0xfff : x; 58338451Smsmith return 0; 58438451Smsmith} 58538451Smsmith 58638451Smsmith/* 58738451Smsmith * Is cluster an end-of-chain marker? 58838451Smsmith */ 58938451Smsmithstatic int 59038451Smsmithfatend(u_int sz, u_int c) 59138451Smsmith{ 59238451Smsmith return c > (sz == 12 ? 0xff7U : sz == 16 ? 0xfff7U : 0xffffff7); 59338451Smsmith} 59438451Smsmith 59538451Smsmith/* 59638451Smsmith * Offset-based I/O primitive 59738451Smsmith */ 59838451Smsmithstatic int 59938451Smsmithioread(DOS_FS *fs, u_int offset, void *buf, u_int nbyte) 60038451Smsmith{ 60138451Smsmith char *s; 60238451Smsmith u_int off, n; 60338451Smsmith int err; 60438451Smsmith 60538451Smsmith s = buf; 60638451Smsmith if ((off = offset & (SECSIZ - 1))) { 60738451Smsmith offset -= off; 60838451Smsmith if ((err = iobuf(fs, bytsec(offset)))) 60938451Smsmith return err; 61038451Smsmith offset += SECSIZ; 61138451Smsmith if ((n = SECSIZ - off) > nbyte) 61238451Smsmith n = nbyte; 61338451Smsmith memcpy(s, fs->buf + off, n); 61438451Smsmith s += n; 61538451Smsmith nbyte -= n; 61638451Smsmith } 61738451Smsmith n = nbyte & (SECSIZ - 1); 61838451Smsmith if (nbyte -= n) { 61938451Smsmith if ((err = ioget(fs->fd, bytsec(offset), s, bytsec(nbyte)))) 62038451Smsmith return err; 62138451Smsmith offset += nbyte; 62238451Smsmith s += nbyte; 62338451Smsmith } 62438451Smsmith if (n) { 62538451Smsmith if ((err = iobuf(fs, bytsec(offset)))) 62638451Smsmith return err; 62738451Smsmith memcpy(s, fs->buf, n); 62838451Smsmith } 62938451Smsmith return 0; 63038451Smsmith} 63138451Smsmith 63238451Smsmith/* 63338451Smsmith * Buffered sector-based I/O primitive 63438451Smsmith */ 63538451Smsmithstatic int 63638451Smsmithiobuf(DOS_FS *fs, u_int lsec) 63738451Smsmith{ 63838451Smsmith int err; 63938451Smsmith 64038451Smsmith if (fs->bufsec != lsec) { 64138451Smsmith if ((err = ioget(fs->fd, lsec, fs->buf, 1))) 64238451Smsmith return err; 64338451Smsmith fs->bufsec = lsec; 64438451Smsmith } 64538451Smsmith return 0; 64638451Smsmith} 64738451Smsmith 64838451Smsmith/* 64938451Smsmith * Sector-based I/O primitive 65038451Smsmith */ 65138451Smsmithstatic int 65238451Smsmithioget(struct open_file *fd, u_int lsec, void *buf, u_int nsec) 65338451Smsmith{ 65438451Smsmith int err; 65538451Smsmith 65638451Smsmith if ((err = (fd->f_dev->dv_strategy)(fd->f_devdata, F_READ, lsec, 65738451Smsmith secbyt(nsec), buf, NULL))) 65838451Smsmith return(err); 65938451Smsmith return(0); 66038451Smsmith} 661