freebsd-src/lib/libstand/cd9660.c
2005-10-18 13:35:08 +00:00

589 lines
15 KiB
C

/* $NetBSD: cd9660.c,v 1.5 1997/06/26 19:11:33 drochner Exp $ */
/*
* Copyright (C) 1996 Wolfgang Solfrank.
* Copyright (C) 1996 TooLs GmbH.
* All rights reserved.
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Stand-alone ISO9660 file reading package.
*
* Note: This doesn't support Rock Ridge extensions, extended attributes,
* blocksizes other than 2048 bytes, multi-extent files, etc.
*/
#include <sys/param.h>
#include <string.h>
#include <sys/dirent.h>
#include <isofs/cd9660/iso.h>
#include <isofs/cd9660/cd9660_rrip.h>
#include "stand.h"
#define SUSP_CONTINUATION "CE"
#define SUSP_PRESENT "SP"
#define SUSP_STOP "ST"
#define SUSP_EXTREF "ER"
#define RRIP_NAME "NM"
typedef struct {
ISO_SUSP_HEADER h;
u_char signature [ISODCL ( 5, 6)];
u_char len_skp [ISODCL ( 7, 7)]; /* 711 */
} ISO_SUSP_PRESENT;
static int buf_read_file(struct open_file *f, char **buf_p,
size_t *size_p);
static int cd9660_open(const char *path, struct open_file *f);
static int cd9660_close(struct open_file *f);
static int cd9660_read(struct open_file *f, void *buf, size_t size,
size_t *resid);
static int cd9660_write(struct open_file *f, void *buf, size_t size,
size_t *resid);
static off_t cd9660_seek(struct open_file *f, off_t offset, int where);
static int cd9660_stat(struct open_file *f, struct stat *sb);
static int cd9660_readdir(struct open_file *f, struct dirent *d);
static int dirmatch(struct open_file *f, const char *path,
struct iso_directory_record *dp, int use_rrip, int lenskip);
static int rrip_check(struct open_file *f, struct iso_directory_record *dp,
int *lenskip);
static char *rrip_lookup_name(struct open_file *f,
struct iso_directory_record *dp, int lenskip, size_t *len);
static ISO_SUSP_HEADER *susp_lookup_record(struct open_file *f,
const char *identifier, struct iso_directory_record *dp,
int lenskip);
struct fs_ops cd9660_fsops = {
"cd9660",
cd9660_open,
cd9660_close,
cd9660_read,
cd9660_write,
cd9660_seek,
cd9660_stat,
cd9660_readdir
};
#define F_ISDIR 0x0001 /* Directory */
#define F_ROOTDIR 0x0002 /* Root directory */
#define F_RR 0x0004 /* Rock Ridge on this volume */
struct file {
int f_flags; /* file flags */
off_t f_off; /* Current offset within file */
daddr_t f_bno; /* Starting block number */
off_t f_size; /* Size of file */
daddr_t f_buf_blkno; /* block number of data block */
char *f_buf; /* buffer for data block */
int f_susp_skip; /* len_skip for SUSP records */
};
struct ptable_ent {
char namlen [ISODCL( 1, 1)]; /* 711 */
char extlen [ISODCL( 2, 2)]; /* 711 */
char block [ISODCL( 3, 6)]; /* 732 */
char parent [ISODCL( 7, 8)]; /* 722 */
char name [1];
};
#define PTFIXSZ 8
#define PTSIZE(pp) roundup(PTFIXSZ + isonum_711((pp)->namlen), 2)
#define cdb2devb(bno) ((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE)
static ISO_SUSP_HEADER *
susp_lookup_record(struct open_file *f, const char *identifier,
struct iso_directory_record *dp, int lenskip)
{
static char susp_buffer[ISO_DEFAULT_BLOCK_SIZE];
ISO_SUSP_HEADER *sh;
ISO_RRIP_CONT *shc;
char *p, *end;
int error;
size_t read;
p = dp->name + isonum_711(dp->name_len) + lenskip;
/* Names of even length have a padding byte after the name. */
if ((isonum_711(dp->name_len) & 1) == 0)
p++;
end = (char *)dp + isonum_711(dp->length);
while (p + 3 < end) {
sh = (ISO_SUSP_HEADER *)p;
if (bcmp(sh->type, identifier, 2) == 0)
return (sh);
if (bcmp(sh->type, SUSP_STOP, 2) == 0)
return (NULL);
if (bcmp(sh->type, SUSP_CONTINUATION, 2) == 0) {
shc = (ISO_RRIP_CONT *)sh;
error = f->f_dev->dv_strategy(f->f_devdata, F_READ,
cdb2devb(isonum_733(shc->location)),
ISO_DEFAULT_BLOCK_SIZE, susp_buffer, &read);
/* Bail if it fails. */
if (error != 0 || read != ISO_DEFAULT_BLOCK_SIZE)
return (NULL);
p = susp_buffer + isonum_733(shc->offset);
end = p + isonum_733(shc->length);
} else
/* Ignore this record and skip to the next. */
p += isonum_711(sh->length);
}
return (NULL);
}
static char *
rrip_lookup_name(struct open_file *f, struct iso_directory_record *dp,
int lenskip, size_t *len)
{
ISO_RRIP_ALTNAME *p;
if (len == NULL)
return (NULL);
p = (ISO_RRIP_ALTNAME *)susp_lookup_record(f, RRIP_NAME, dp, lenskip);
if (p == NULL)
return (NULL);
switch (*p->flags) {
case ISO_SUSP_CFLAG_CURRENT:
*len = 1;
return (".");
case ISO_SUSP_CFLAG_PARENT:
*len = 2;
return ("..");
case 0:
*len = isonum_711(p->h.length) - 5;
return ((char *)p + 5);
default:
/*
* We don't handle hostnames or continued names as they are
* too hard, so just bail and use the default name.
*/
return (NULL);
}
}
static int
rrip_check(struct open_file *f, struct iso_directory_record *dp, int *lenskip)
{
ISO_SUSP_PRESENT *sp;
ISO_RRIP_EXTREF *er;
char *p;
/* First, see if we can find a SP field. */
p = dp->name + isonum_711(dp->name_len);
if (p > (char *)dp + isonum_711(dp->length))
return (0);
sp = (ISO_SUSP_PRESENT *)p;
if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0)
return (0);
if (isonum_711(sp->h.length) != sizeof(ISO_SUSP_PRESENT))
return (0);
if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef)
return (0);
*lenskip = isonum_711(sp->len_skp);
/*
* Now look for an ER field. If RRIP is present, then there must
* be at least one of these. It would be more pedantic to walk
* through the list of fields looking for a Rock Ridge ER field.
*/
er = (ISO_RRIP_EXTREF *)susp_lookup_record(f, SUSP_EXTREF, dp, 0);
if (er == NULL)
return (0);
return (1);
}
static int
dirmatch(struct open_file *f, const char *path, struct iso_directory_record *dp,
int use_rrip, int lenskip)
{
size_t len;
char *cp;
int i, icase;
if (use_rrip)
cp = rrip_lookup_name(f, dp, lenskip, &len);
else
cp = NULL;
if (cp == NULL) {
len = isonum_711(dp->name_len);
cp = dp->name;
icase = 1;
} else
icase = 0;
for (i = len; --i >= 0; path++, cp++) {
if (!*path || *path == '/')
break;
if (*path == *cp)
continue;
if (!icase && toupper(*path) == *cp)
continue;
return 0;
}
if (*path && *path != '/')
return 0;
/*
* Allow stripping of trailing dots and the version number.
* Note that this will find the first instead of the last version
* of a file.
*/
if (i >= 0 && (*cp == ';' || *cp == '.')) {
/* This is to prevent matching of numeric extensions */
if (*cp == '.' && cp[1] != ';')
return 0;
while (--i >= 0)
if (*++cp != ';' && (*cp < '0' || *cp > '9'))
return 0;
}
return 1;
}
static int
cd9660_open(const char *path, struct open_file *f)
{
struct file *fp = 0;
void *buf;
struct iso_primary_descriptor *vd;
size_t buf_size, read, dsize, off;
daddr_t bno, boff;
struct iso_directory_record rec;
struct iso_directory_record *dp = 0;
int rc, first, use_rrip, lenskip;
/* First find the volume descriptor */
buf = malloc(buf_size = ISO_DEFAULT_BLOCK_SIZE);
vd = buf;
for (bno = 16;; bno++) {
twiddle();
rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
ISO_DEFAULT_BLOCK_SIZE, buf, &read);
if (rc)
goto out;
if (read != ISO_DEFAULT_BLOCK_SIZE) {
rc = EIO;
goto out;
}
rc = EINVAL;
if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0)
goto out;
if (isonum_711(vd->type) == ISO_VD_END)
goto out;
if (isonum_711(vd->type) == ISO_VD_PRIMARY)
break;
}
if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE)
goto out;
rec = *(struct iso_directory_record *) vd->root_directory_record;
if (*path == '/') path++; /* eat leading '/' */
first = 1;
use_rrip = 0;
while (*path) {
bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
dsize = isonum_733(rec.size);
off = 0;
boff = 0;
while (off < dsize) {
if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) {
twiddle();
rc = f->f_dev->dv_strategy
(f->f_devdata, F_READ,
cdb2devb(bno + boff),
ISO_DEFAULT_BLOCK_SIZE,
buf, &read);
if (rc)
goto out;
if (read != ISO_DEFAULT_BLOCK_SIZE) {
rc = EIO;
goto out;
}
boff++;
dp = (struct iso_directory_record *) buf;
}
if (isonum_711(dp->length) == 0) {
/* skip to next block, if any */
off = boff * ISO_DEFAULT_BLOCK_SIZE;
continue;
}
/* See if RRIP is in use. */
if (first)
use_rrip = rrip_check(f, dp, &lenskip);
if (dirmatch(f, path, dp, use_rrip,
first ? 0 : lenskip)) {
first = 0;
break;
} else
first = 0;
dp = (struct iso_directory_record *)
((char *) dp + isonum_711(dp->length));
off += isonum_711(dp->length);
}
if (off >= dsize) {
rc = ENOENT;
goto out;
}
rec = *dp;
while (*path && *path != '/') /* look for next component */
path++;
if (*path) path++; /* skip '/' */
}
/* allocate file system specific data structure */
fp = malloc(sizeof(struct file));
bzero(fp, sizeof(struct file));
f->f_fsdata = (void *)fp;
if ((isonum_711(rec.flags) & 2) != 0) {
fp->f_flags = F_ISDIR;
}
if (first) {
fp->f_flags |= F_ROOTDIR;
/* Check for Rock Ridge since we didn't in the loop above. */
bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
twiddle();
rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
ISO_DEFAULT_BLOCK_SIZE, buf, &read);
if (rc)
goto out;
if (read != ISO_DEFAULT_BLOCK_SIZE) {
rc = EIO;
goto out;
}
dp = (struct iso_directory_record *)buf;
use_rrip = rrip_check(f, dp, &lenskip);
}
if (use_rrip) {
fp->f_flags |= F_RR;
fp->f_susp_skip = lenskip;
}
fp->f_off = 0;
fp->f_bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
fp->f_size = isonum_733(rec.size);
free(buf);
return 0;
out:
if (fp)
free(fp);
free(buf);
return rc;
}
static int
cd9660_close(struct open_file *f)
{
struct file *fp = (struct file *)f->f_fsdata;
f->f_fsdata = 0;
free(fp);
return 0;
}
static int
buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
{
struct file *fp = (struct file *)f->f_fsdata;
daddr_t blkno, blkoff;
int rc = 0;
size_t read;
blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE + fp->f_bno;
blkoff = fp->f_off % ISO_DEFAULT_BLOCK_SIZE;
if (blkno != fp->f_buf_blkno) {
if (fp->f_buf == (char *)0)
fp->f_buf = malloc(ISO_DEFAULT_BLOCK_SIZE);
twiddle();
rc = f->f_dev->dv_strategy(f->f_devdata, F_READ,
cdb2devb(blkno), ISO_DEFAULT_BLOCK_SIZE, fp->f_buf, &read);
if (rc)
return (rc);
if (read != ISO_DEFAULT_BLOCK_SIZE)
return (EIO);
fp->f_buf_blkno = blkno;
}
*buf_p = fp->f_buf + blkoff;
*size_p = ISO_DEFAULT_BLOCK_SIZE - blkoff;
if (*size_p > fp->f_size - fp->f_off)
*size_p = fp->f_size - fp->f_off;
return (rc);
}
static int
cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
{
struct file *fp = (struct file *)f->f_fsdata;
char *buf, *addr;
size_t buf_size, csize;
int rc = 0;
addr = start;
while (size) {
if (fp->f_off < 0 || fp->f_off >= fp->f_size)
break;
rc = buf_read_file(f, &buf, &buf_size);
if (rc)
break;
csize = size > buf_size ? buf_size : size;
bcopy(buf, addr, csize);
fp->f_off += csize;
addr += csize;
size -= csize;
}
if (resid)
*resid = size;
return (rc);
}
static int
cd9660_readdir(struct open_file *f, struct dirent *d)
{
struct file *fp = (struct file *)f->f_fsdata;
struct iso_directory_record *ep;
size_t buf_size, reclen, namelen;
int error = 0;
int lenskip;
char *buf, *name;
again:
if (fp->f_off >= fp->f_size)
return (ENOENT);
error = buf_read_file(f, &buf, &buf_size);
if (error)
return (error);
ep = (struct iso_directory_record *)buf;
if (isonum_711(ep->length) == 0) {
daddr_t blkno;
/* skip to next block, if any */
blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE;
fp->f_off = (blkno + 1) * ISO_DEFAULT_BLOCK_SIZE;
goto again;
}
if (fp->f_flags & F_RR) {
if (fp->f_flags & F_ROOTDIR && fp->f_off == 0)
lenskip = 0;
else
lenskip = fp->f_susp_skip;
name = rrip_lookup_name(f, ep, lenskip, &namelen);
} else
name = NULL;
if (name == NULL) {
namelen = isonum_711(ep->name_len);
name = ep->name;
if (namelen == 1) {
if (ep->name[0] == 0)
name = ".";
else if (ep->name[0] == 1) {
namelen = 2;
name = "..";
}
}
}
reclen = sizeof(struct dirent) - (MAXNAMLEN+1) + namelen + 1;
reclen = (reclen + 3) & ~3;
d->d_fileno = isonum_733(ep->extent);
d->d_reclen = reclen;
if (isonum_711(ep->flags) & 2)
d->d_type = DT_DIR;
else
d->d_type = DT_REG;
d->d_namlen = namelen;
bcopy(name, d->d_name, d->d_namlen);
d->d_name[d->d_namlen] = 0;
fp->f_off += isonum_711(ep->length);
return (0);
}
static int
cd9660_write(struct open_file *f, void *start, size_t size, size_t *resid)
{
return EROFS;
}
static off_t
cd9660_seek(struct open_file *f, off_t offset, int where)
{
struct file *fp = (struct file *)f->f_fsdata;
switch (where) {
case SEEK_SET:
fp->f_off = offset;
break;
case SEEK_CUR:
fp->f_off += offset;
break;
case SEEK_END:
fp->f_off = fp->f_size - offset;
break;
default:
return -1;
}
return fp->f_off;
}
static int
cd9660_stat(struct open_file *f, struct stat *sb)
{
struct file *fp = (struct file *)f->f_fsdata;
/* only important stuff */
sb->st_mode = S_IRUSR | S_IRGRP | S_IROTH;
if (fp->f_flags & F_ISDIR)
sb->st_mode |= S_IFDIR;
else
sb->st_mode |= S_IFREG;
sb->st_uid = sb->st_gid = 0;
sb->st_size = fp->f_size;
return 0;
}