freebsd-dev/sys/geom/geom_bsd.c
Poul-Henning Kamp 07107de9bc Introduce the concept of "magic spaces", and implement them in most of
the relevant classes.

Some methods may implement various "magic spaces", this is reserved
or magic areas on the disk, set a side for various and sundry purposes.
A good example is the BSD disklabel and boot code on i386 which occupies
a total of four magic spaces: boot1, the disklabel, the padding behind
the disklabel and boot2.  The reason we don't simply tell people to
write the appropriate stuff on the underlying device is that (some of)
the magic spaces might be real-time modifiable.  It is for instance
possible to change a disklabel while partitions are open, provided
the open partitions do not get trampled in the process.

Sponsored by:	DARPA & NAI Labs.
2002-05-21 20:33:49 +00:00

433 lines
12 KiB
C

/*-
* Copyright (c) 2002 Poul-Henning Kamp
* Copyright (c) 2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Poul-Henning Kamp
* and NAI Labs, the Security Research Division of Network Associates, Inc.
* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
* DARPA CHATS research program.
*
* 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. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#ifndef _KERNEL
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>
#include <err.h>
#else
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/bio.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#endif
#include <sys/errno.h>
#include <sys/disklabel.h>
#include <geom/geom.h>
#include <geom/geom_slice.h>
#define BSD_CLASS_NAME "BSD"
struct g_bsd_softc {
off_t labeloffset;
struct disklabel ondisk;
struct disklabel inram;
};
static void
g_bsd_ledec_partition(u_char *ptr, struct partition *d)
{
d->p_size = g_dec_le4(ptr + 0);
d->p_offset = g_dec_le4(ptr + 4);
d->p_fsize = g_dec_le4(ptr + 8);
d->p_fstype = ptr[12];
d->p_frag = ptr[13];
d->p_cpg = g_dec_le2(ptr + 14);
}
static void
g_bsd_ledec_disklabel(u_char *ptr, struct disklabel *d)
{
d->d_magic = g_dec_le4(ptr + 0);
d->d_type = g_dec_le2(ptr + 4);
d->d_subtype = g_dec_le2(ptr + 6);
bcopy(ptr + 8, d->d_typename, 16);
bcopy(d->d_packname, ptr + 24, 16);
d->d_secsize = g_dec_le4(ptr + 40);
d->d_nsectors = g_dec_le4(ptr + 44);
d->d_ntracks = g_dec_le4(ptr + 48);
d->d_ncylinders = g_dec_le4(ptr + 52);
d->d_secpercyl = g_dec_le4(ptr + 56);
d->d_secperunit = g_dec_le4(ptr + 60);
d->d_sparespertrack = g_dec_le2(ptr + 64);
d->d_sparespercyl = g_dec_le2(ptr + 66);
d->d_acylinders = g_dec_le4(ptr + 68);
d->d_rpm = g_dec_le2(ptr + 72);
d->d_interleave = g_dec_le2(ptr + 74);
d->d_trackskew = g_dec_le2(ptr + 76);
d->d_cylskew = g_dec_le2(ptr + 78);
d->d_headswitch = g_dec_le4(ptr + 80);
d->d_trkseek = g_dec_le4(ptr + 84);
d->d_flags = g_dec_le4(ptr + 88);
d->d_drivedata[0] = g_dec_le4(ptr + 92);
d->d_drivedata[1] = g_dec_le4(ptr + 96);
d->d_drivedata[2] = g_dec_le4(ptr + 100);
d->d_drivedata[3] = g_dec_le4(ptr + 104);
d->d_drivedata[4] = g_dec_le4(ptr + 108);
d->d_spare[0] = g_dec_le4(ptr + 112);
d->d_spare[1] = g_dec_le4(ptr + 116);
d->d_spare[2] = g_dec_le4(ptr + 120);
d->d_spare[3] = g_dec_le4(ptr + 124);
d->d_spare[4] = g_dec_le4(ptr + 128);
d->d_magic2 = g_dec_le4(ptr + 132);
d->d_checksum = g_dec_le2(ptr + 136);
d->d_npartitions = g_dec_le2(ptr + 138);
d->d_bbsize = g_dec_le4(ptr + 140);
d->d_sbsize = g_dec_le4(ptr + 144);
g_bsd_ledec_partition(ptr + 148, &d->d_partitions[0]);
g_bsd_ledec_partition(ptr + 164, &d->d_partitions[1]);
g_bsd_ledec_partition(ptr + 180, &d->d_partitions[2]);
g_bsd_ledec_partition(ptr + 196, &d->d_partitions[3]);
g_bsd_ledec_partition(ptr + 212, &d->d_partitions[4]);
g_bsd_ledec_partition(ptr + 228, &d->d_partitions[5]);
g_bsd_ledec_partition(ptr + 244, &d->d_partitions[6]);
g_bsd_ledec_partition(ptr + 260, &d->d_partitions[7]);
}
#if 0
static void
g_bsd_leenc_partition(u_char *ptr, struct partition *d)
{
g_enc_le4(ptr + 0, d->p_size);
g_enc_le4(ptr + 4, d->p_offset);
g_enc_le4(ptr + 8, d->p_fsize);
ptr[12] = d->p_fstype;
ptr[13] = d->p_frag;
g_enc_le2(ptr + 14, d->p_cpg);
}
static void
g_bsd_leenc_disklabel(u_char *ptr, struct disklabel *d)
{
g_enc_le4(ptr + 0, d->d_magic);
g_enc_le2(ptr + 4, d->d_type);
g_enc_le2(ptr + 6, d->d_subtype);
bcopy(d->d_typename, ptr + 8, 16);
bcopy(d->d_packname, ptr + 24, 16);
g_enc_le4(ptr + 40, d->d_secsize);
g_enc_le4(ptr + 44, d->d_nsectors);
g_enc_le4(ptr + 48, d->d_ntracks);
g_enc_le4(ptr + 52, d->d_ncylinders);
g_enc_le4(ptr + 56, d->d_secpercyl);
g_enc_le4(ptr + 60, d->d_secperunit);
g_enc_le2(ptr + 64, d->d_sparespertrack);
g_enc_le2(ptr + 66, d->d_sparespercyl);
g_enc_le4(ptr + 68, d->d_acylinders);
g_enc_le2(ptr + 72, d->d_rpm);
g_enc_le2(ptr + 74, d->d_interleave);
g_enc_le2(ptr + 76, d->d_trackskew);
g_enc_le2(ptr + 78, d->d_cylskew);
g_enc_le4(ptr + 80, d->d_headswitch);
g_enc_le4(ptr + 84, d->d_trkseek);
g_enc_le4(ptr + 88, d->d_flags);
g_enc_le4(ptr + 92, d->d_drivedata[0]);
g_enc_le4(ptr + 96, d->d_drivedata[1]);
g_enc_le4(ptr + 100, d->d_drivedata[2]);
g_enc_le4(ptr + 104, d->d_drivedata[3]);
g_enc_le4(ptr + 108, d->d_drivedata[4]);
g_enc_le4(ptr + 112, d->d_spare[0]);
g_enc_le4(ptr + 116, d->d_spare[1]);
g_enc_le4(ptr + 120, d->d_spare[2]);
g_enc_le4(ptr + 124, d->d_spare[3]);
g_enc_le4(ptr + 128, d->d_spare[4]);
g_enc_le4(ptr + 132, d->d_magic2);
g_enc_le2(ptr + 136, d->d_checksum);
g_enc_le2(ptr + 138, d->d_npartitions);
g_enc_le4(ptr + 140, d->d_bbsize);
g_enc_le4(ptr + 144, d->d_sbsize);
g_bsd_leenc_partition(ptr + 148, &d->d_partitions[0]);
g_bsd_leenc_partition(ptr + 164, &d->d_partitions[1]);
g_bsd_leenc_partition(ptr + 180, &d->d_partitions[2]);
g_bsd_leenc_partition(ptr + 196, &d->d_partitions[3]);
g_bsd_leenc_partition(ptr + 212, &d->d_partitions[4]);
g_bsd_leenc_partition(ptr + 228, &d->d_partitions[5]);
g_bsd_leenc_partition(ptr + 244, &d->d_partitions[6]);
g_bsd_leenc_partition(ptr + 260, &d->d_partitions[7]);
}
#endif
static void
ondisk2inram(struct g_bsd_softc *sc)
{
struct partition *ppp;
unsigned offset;
int i;
sc->inram = sc->ondisk;
offset = sc->inram.d_partitions[RAW_PART].p_offset;
for (i = 0; i < 8; i++) {
ppp = &sc->inram.d_partitions[i];
if (ppp->p_offset >= offset)
ppp->p_offset -= offset;
}
sc->inram.d_checksum = 0;
sc->inram.d_checksum = dkcksum(&sc->inram);
}
/*
* It is rather fortunate that this checksum only covers up to the
* actual end of actual data, otherwise the pointer-screwup in
* alpha architectures would have been much harder to handle.
*/
static int
g_bsd_lesum(struct disklabel *dl, u_char *p)
{
u_char *pe;
uint16_t sum;
pe = p + 148 + 16 * dl->d_npartitions;
sum = 0;
while (p < pe) {
sum ^= g_dec_le2(p);
p += 2;
}
return (sum);
}
static int
g_bsd_try(struct g_slicer *gsp, struct g_consumer *cp, int secsize, struct g_bsd_softc *ms, off_t offset)
{
int error;
u_char *buf;
struct disklabel *dl;
off_t secoff;
dl = &ms->ondisk;
secoff = offset % secsize;
buf = g_read_data(cp, offset - secoff, secsize, &error);
if (buf == NULL || error != 0)
return(ENOENT);
g_bsd_ledec_disklabel(buf + secoff, dl);
if (dl->d_magic == DISKMAGIC &&
dl->d_magic2 == DISKMAGIC &&
g_bsd_lesum(dl, buf + secoff) == 0)
error = 0;
else
error = ENOENT;
g_free(buf);
if (error == 0) {
gsp->frontstuff = 16 * secsize;
ms->labeloffset = offset;
}
return(error);
}
static int
g_bsd_start(struct bio *bp)
{
struct g_geom *gp;
struct g_bsd_softc *ms;
struct g_slicer *gsp;
struct g_ioctl *gio;
gp = bp->bio_to->geom;
gsp = gp->softc;
ms = gsp->softc;
if (strcmp(bp->bio_attribute, "GEOM::ioctl"))
return(0);
else if (bp->bio_length != sizeof *gio)
return(0);
gio = (struct g_ioctl *)bp->bio_data;
if (gio->cmd == DIOCGDINFO) {
bcopy(&ms->inram, gio->data, sizeof ms->inram);
bp->bio_error = 0;
g_io_deliver(bp);
return (1);
}
return (0);
}
static void
g_bsd_dumpconf(struct sbuf *sb, char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
{
struct g_bsd_softc *ms;
struct g_slicer *gsp;
gsp = gp->softc;
ms = gsp->softc;
if (pp == NULL && cp == NULL) {
sbuf_printf(sb, "%s<labeloffset>%lld</labeloffset>\n",
indent, ms->labeloffset);
}
g_slice_dumpconf(sb, indent, gp, cp, pp);
}
static struct g_geom *
g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags)
{
struct g_geom *gp;
struct g_consumer *cp;
struct g_provider *pp2;
int error, i, j, npart;
struct g_bsd_softc *ms;
struct disklabel *dl;
u_int secsize;
u_int fwsectors, fwheads;
off_t mediasize;
struct partition *ppp, *ppr;
struct g_slicer *gsp;
g_trace(G_T_TOPOLOGY, "bsd_taste(%s,%s)", mp->name, pp->name);
g_topology_assert();
if (flags == G_TF_NORMAL &&
!strcmp(pp->geom->class->name, BSD_CLASS_NAME))
return (NULL);
gp = g_slice_new(mp, 8, pp, &cp, &ms, sizeof *ms, g_bsd_start);
if (gp == NULL)
return (NULL);
gsp = gp->softc;
g_topology_unlock();
gp->dumpconf = g_bsd_dumpconf;
npart = 0;
while (1) { /* a trick to allow us to use break */
error = g_getattr("MBR::type", cp, &i);
if (!error && i != 165 && flags == G_TF_NORMAL)
break;
error = g_getattr("GEOM::sectorsize", cp, &secsize);
if (error) {
secsize = 512;
printf("g_bsd_taste: error %d Sectors are %d bytes\n",
error, secsize);
}
error = g_getattr("GEOM::mediasize", cp, &mediasize);
if (error) {
mediasize = 0;
printf("g_error %d Mediasize is %lld bytes\n",
error, (long long)mediasize);
}
error = g_bsd_try(gsp, cp, secsize, ms, secsize);
if (!error) {
g_new_magicspaces(gp, 4);
g_add_magicspace(gp, 0, "boot1", 0, 512, 0);
g_add_magicspace(gp, 1, "label", 512, 276, 0);
g_add_magicspace(gp, 2, "fill0", 748, 236, 0);
g_add_magicspace(gp, 3, "boot2", 1024, 7168, 0);
}
if (error) {
error = g_bsd_try(gsp, cp, secsize, ms, 64);
if (!error) {
g_new_magicspaces(gp, 3);
g_add_magicspace(gp, 0, "fill0", 0, 64, 0);
g_add_magicspace(gp, 1, "label", 64, 276, 0);
g_add_magicspace(gp, 2, "fill1", 340, 172, 0);
}
}
if (error)
break;
dl = &ms->ondisk;
if (bootverbose)
g_hexdump(dl, sizeof(*dl));
if (dl->d_secsize < secsize)
break;
if (dl->d_secsize > secsize)
secsize = dl->d_secsize;
ppr = &dl->d_partitions[2];
for (i = 0; i < 8; i++) {
ppp = &dl->d_partitions[i];
if (ppp->p_size == 0)
continue;
npart++;
pp2 = g_slice_addslice(gp, i,
((off_t)(ppp->p_offset - ppr->p_offset)) << 9ULL,
((off_t)ppp->p_size) << 9ULL,
"%s%c", pp->name, 'a' + i);
g_error_provider(pp2, 0);
}
ondisk2inram(ms);
break;
}
if (npart == 0 && (
(flags == G_TF_INSIST && mediasize != 0) ||
(flags == G_TF_TRANSPARENT))) {
dl = &ms->ondisk;
bzero(dl, sizeof *dl);
dl->d_magic = DISKMAGIC;
dl->d_magic2 = DISKMAGIC;
ppp = &dl->d_partitions[RAW_PART];
ppp->p_offset = 0;
ppp->p_size = mediasize / secsize;
dl->d_npartitions = MAXPARTITIONS;
dl->d_interleave = 1;
dl->d_secsize = secsize;
dl->d_rpm = 3600;
j = sizeof fwsectors;
error = g_io_getattr("GEOM::fwsectors", cp, &j, &fwsectors);
if (error)
dl->d_nsectors = 32;
else
dl->d_nsectors = fwsectors;
error = g_io_getattr("GEOM::fwheads", cp, &j, &fwheads);
if (error)
dl->d_ntracks = 64;
else
dl->d_ntracks = fwheads;
dl->d_secpercyl = dl->d_nsectors * dl->d_ntracks;
dl->d_ncylinders = ppp->p_size / dl->d_secpercyl;
dl->d_secperunit = ppp->p_size;
dl->d_checksum = 0;
dl->d_checksum = dkcksum(dl);
ms->inram = ms->ondisk;
pp2 = g_slice_addslice(gp, RAW_PART,
0, mediasize, "%s%c", pp->name, 'a' + RAW_PART);
g_error_provider(pp2, 0);
npart = 1;
}
g_topology_lock();
error = g_access_rel(cp, -1, 0, 0);
if (npart > 0)
return (gp);
g_std_spoiled(cp);
return (NULL);
}
static struct g_class g_bsd_class = {
BSD_CLASS_NAME,
g_bsd_taste,
NULL,
G_CLASS_INITSTUFF
};
DECLARE_GEOM_CLASS(g_bsd_class, g_bsd);