freebsd-dev/sys/geom/geom_bsd.c
Alexander Leidinger cb08c2cc83 Add some FEATURE macros for various GEOM classes.
No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.

Sponsored by:	Google Summer of Code 2010
Submitted by:	kibab
Reviewed by:	silence on geom@ during 2 weeks
X-MFC after:	to be determined in last commit with code from this project
2011-02-25 10:24:35 +00:00

703 lines
19 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.
*/
/*
* This is the method for dealing with BSD disklabels. It has been
* extensively (by my standards at least) commented, in the vain hope that
* it will serve as the source in future copy&paste operations.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/endian.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/conf.h>
#include <sys/bio.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/md5.h>
#include <sys/errno.h>
#include <sys/disklabel.h>
#include <sys/gpt.h>
#include <sys/uuid.h>
#include <geom/geom.h>
#include <geom/geom_slice.h>
FEATURE(geom_bsd, "GEOM BSD disklabels support");
#define BSD_CLASS_NAME "BSD"
#define ALPHA_LABEL_OFFSET 64
#define HISTORIC_LABEL_OFFSET 512
#define LABELSIZE (148 + 16 * MAXPARTITIONS)
static void g_bsd_hotwrite(void *arg, int flag);
/*
* Our private data about one instance. All the rest is handled by the
* slice code and stored in its softc, so this is just the stuff
* specific to BSD disklabels.
*/
struct g_bsd_softc {
off_t labeloffset;
off_t mbroffset;
off_t rawoffset;
struct disklabel ondisk;
u_char label[LABELSIZE];
u_char labelsum[16];
};
/*
* Modify our slicer to match proposed disklabel, if possible.
* This is where we make sure we don't do something stupid.
*/
static int
g_bsd_modify(struct g_geom *gp, u_char *label)
{
int i, error;
struct partition *ppp;
struct g_slicer *gsp;
struct g_consumer *cp;
struct g_bsd_softc *ms;
u_int secsize, u;
off_t rawoffset, o;
struct disklabel dl;
MD5_CTX md5sum;
g_topology_assert();
gsp = gp->softc;
ms = gsp->softc;
error = bsd_disklabel_le_dec(label, &dl, MAXPARTITIONS);
if (error) {
return (error);
}
/* Get dimensions of our device. */
cp = LIST_FIRST(&gp->consumer);
secsize = cp->provider->sectorsize;
/* ... or a smaller sector size. */
if (dl.d_secsize < secsize) {
return (EINVAL);
}
/* ... or a non-multiple sector size. */
if (dl.d_secsize % secsize != 0) {
return (EINVAL);
}
/* Historical braindamage... */
rawoffset = (off_t)dl.d_partitions[RAW_PART].p_offset * dl.d_secsize;
for (i = 0; i < dl.d_npartitions; i++) {
ppp = &dl.d_partitions[i];
if (ppp->p_size == 0)
continue;
o = (off_t)ppp->p_offset * dl.d_secsize;
if (o < rawoffset)
rawoffset = 0;
}
if (rawoffset != 0 && (off_t)rawoffset != ms->mbroffset)
printf("WARNING: %s expected rawoffset %jd, found %jd\n",
gp->name,
(intmax_t)ms->mbroffset/dl.d_secsize,
(intmax_t)rawoffset/dl.d_secsize);
/* Don't munge open partitions. */
for (i = 0; i < dl.d_npartitions; i++) {
ppp = &dl.d_partitions[i];
o = (off_t)ppp->p_offset * dl.d_secsize;
if (o == 0)
o = rawoffset;
error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
o - rawoffset,
(off_t)ppp->p_size * dl.d_secsize,
dl.d_secsize,
"%s%c", gp->name, 'a' + i);
if (error)
return (error);
}
/* Look good, go for it... */
for (u = 0; u < gsp->nslice; u++) {
ppp = &dl.d_partitions[u];
o = (off_t)ppp->p_offset * dl.d_secsize;
if (o == 0)
o = rawoffset;
g_slice_config(gp, u, G_SLICE_CONFIG_SET,
o - rawoffset,
(off_t)ppp->p_size * dl.d_secsize,
dl.d_secsize,
"%s%c", gp->name, 'a' + u);
}
/* Update our softc */
ms->ondisk = dl;
if (label != ms->label)
bcopy(label, ms->label, LABELSIZE);
ms->rawoffset = rawoffset;
/*
* In order to avoid recursively attaching to the same
* on-disk label (it's usually visible through the 'c'
* partition) we calculate an MD5 and ask if other BSD's
* below us love that label. If they do, we don't.
*/
MD5Init(&md5sum);
MD5Update(&md5sum, ms->label, sizeof(ms->label));
MD5Final(ms->labelsum, &md5sum);
return (0);
}
/*
* This is an internal helper function, called multiple times from the taste
* function to try to locate a disklabel on the disk. More civilized formats
* will not need this, as there is only one possible place on disk to look
* for the magic spot.
*/
static int
g_bsd_try(struct g_geom *gp, 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;
/*
* We need to read entire aligned sectors, and we assume that the
* disklabel does not span sectors, so one sector is enough.
*/
secoff = offset % secsize;
buf = g_read_data(cp, offset - secoff, secsize, NULL);
if (buf == NULL)
return (ENOENT);
/* Decode into our native format. */
dl = &ms->ondisk;
error = bsd_disklabel_le_dec(buf + secoff, dl, MAXPARTITIONS);
if (!error)
bcopy(buf + secoff, ms->label, LABELSIZE);
/* Remember to free the buffer g_read_data() gave us. */
g_free(buf);
ms->labeloffset = offset;
return (error);
}
/*
* This function writes the current label to disk, possibly updating
* the alpha SRM checksum.
*/
static int
g_bsd_writelabel(struct g_geom *gp, u_char *bootcode)
{
off_t secoff;
u_int secsize;
struct g_consumer *cp;
struct g_slicer *gsp;
struct g_bsd_softc *ms;
u_char *buf;
uint64_t sum;
int error, i;
gsp = gp->softc;
ms = gsp->softc;
cp = LIST_FIRST(&gp->consumer);
/* Get sector size, we need it to read data. */
secsize = cp->provider->sectorsize;
secoff = ms->labeloffset % secsize;
if (bootcode == NULL) {
buf = g_read_data(cp, ms->labeloffset - secoff, secsize, &error);
if (buf == NULL)
return (error);
bcopy(ms->label, buf + secoff, sizeof(ms->label));
} else {
buf = bootcode;
bcopy(ms->label, buf + ms->labeloffset, sizeof(ms->label));
}
if (ms->labeloffset == ALPHA_LABEL_OFFSET) {
sum = 0;
for (i = 0; i < 63; i++)
sum += le64dec(buf + i * 8);
le64enc(buf + 504, sum);
}
if (bootcode == NULL) {
error = g_write_data(cp, ms->labeloffset - secoff, buf, secsize);
g_free(buf);
} else {
error = g_write_data(cp, 0, bootcode, BBSIZE);
}
return(error);
}
/*
* If the user tries to overwrite our disklabel through an open partition
* or via a magicwrite config call, we end up here and try to prevent
* footshooting as best we can.
*/
static void
g_bsd_hotwrite(void *arg, int flag)
{
struct bio *bp;
struct g_geom *gp;
struct g_slicer *gsp;
struct g_slice *gsl;
struct g_bsd_softc *ms;
u_char *p;
int error;
g_topology_assert();
/*
* We should never get canceled, because that would amount to a removal
* of the geom while there was outstanding I/O requests.
*/
KASSERT(flag != EV_CANCEL, ("g_bsd_hotwrite cancelled"));
bp = arg;
gp = bp->bio_to->geom;
gsp = gp->softc;
ms = gsp->softc;
gsl = &gsp->slices[bp->bio_to->index];
p = (u_char*)bp->bio_data + ms->labeloffset
- (bp->bio_offset + gsl->offset);
error = g_bsd_modify(gp, p);
if (error) {
g_io_deliver(bp, EPERM);
return;
}
g_slice_finish_hot(bp);
}
/*-
* This start routine is only called for non-trivial requests, all the
* trivial ones are handled autonomously by the slice code.
* For requests we handle here, we must call the g_io_deliver() on the
* bio, and return non-zero to indicate to the slice code that we did so.
* This code executes in the "DOWN" I/O path, this means:
* * No sleeping.
* * Don't grab the topology lock.
* * Don't call biowait, g_getattr(), g_setattr() or g_read_data()
*/
static int
g_bsd_ioctl(struct g_provider *pp, u_long cmd, void *data, int fflag, struct thread *td)
{
struct g_geom *gp;
struct g_bsd_softc *ms;
struct g_slicer *gsp;
u_char *label;
int error;
gp = pp->geom;
gsp = gp->softc;
ms = gsp->softc;
switch(cmd) {
case DIOCGDINFO:
/* Return a copy of the disklabel to userland. */
bsd_disklabel_le_dec(ms->label, data, MAXPARTITIONS);
return(0);
case DIOCBSDBB: {
struct g_consumer *cp;
u_char *buf;
void *p;
int error, i;
uint64_t sum;
if (!(fflag & FWRITE))
return (EPERM);
/* The disklabel to set is the ioctl argument. */
buf = g_malloc(BBSIZE, M_WAITOK);
p = *(void **)data;
error = copyin(p, buf, BBSIZE);
if (!error) {
/* XXX: Rude, but supposedly safe */
DROP_GIANT();
g_topology_lock();
/* Validate and modify our slice instance to match. */
error = g_bsd_modify(gp, buf + ms->labeloffset);
if (!error) {
cp = LIST_FIRST(&gp->consumer);
if (ms->labeloffset == ALPHA_LABEL_OFFSET) {
sum = 0;
for (i = 0; i < 63; i++)
sum += le64dec(buf + i * 8);
le64enc(buf + 504, sum);
}
error = g_write_data(cp, 0, buf, BBSIZE);
}
g_topology_unlock();
PICKUP_GIANT();
}
g_free(buf);
return (error);
}
case DIOCSDINFO:
case DIOCWDINFO: {
if (!(fflag & FWRITE))
return (EPERM);
label = g_malloc(LABELSIZE, M_WAITOK);
/* The disklabel to set is the ioctl argument. */
bsd_disklabel_le_enc(label, data);
DROP_GIANT();
g_topology_lock();
/* Validate and modify our slice instance to match. */
error = g_bsd_modify(gp, label);
if (error == 0 && cmd == DIOCWDINFO)
error = g_bsd_writelabel(gp, NULL);
g_topology_unlock();
PICKUP_GIANT();
g_free(label);
return(error);
}
default:
return (ENOIOCTL);
}
}
static int
g_bsd_start(struct bio *bp)
{
struct g_geom *gp;
struct g_bsd_softc *ms;
struct g_slicer *gsp;
gp = bp->bio_to->geom;
gsp = gp->softc;
ms = gsp->softc;
if (bp->bio_cmd == BIO_GETATTR) {
if (g_handleattr(bp, "BSD::labelsum", ms->labelsum,
sizeof(ms->labelsum)))
return (1);
}
return (0);
}
/*
* Dump configuration information in XML format.
* Notice that the function is called once for the geom and once for each
* consumer and provider. We let g_slice_dumpconf() do most of the work.
*/
static void
g_bsd_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
{
struct g_bsd_softc *ms;
struct g_slicer *gsp;
gsp = gp->softc;
ms = gsp->softc;
g_slice_dumpconf(sb, indent, gp, cp, pp);
if (indent != NULL && pp == NULL && cp == NULL) {
sbuf_printf(sb, "%s<labeloffset>%jd</labeloffset>\n",
indent, (intmax_t)ms->labeloffset);
sbuf_printf(sb, "%s<rawoffset>%jd</rawoffset>\n",
indent, (intmax_t)ms->rawoffset);
sbuf_printf(sb, "%s<mbroffset>%jd</mbroffset>\n",
indent, (intmax_t)ms->mbroffset);
} else if (pp != NULL) {
if (indent == NULL)
sbuf_printf(sb, " ty %d",
ms->ondisk.d_partitions[pp->index].p_fstype);
else
sbuf_printf(sb, "%s<type>%d</type>\n", indent,
ms->ondisk.d_partitions[pp->index].p_fstype);
}
}
/*
* The taste function is called from the event-handler, with the topology
* lock already held and a provider to examine. The flags are unused.
*
* If flags == G_TF_NORMAL, the idea is to take a bite of the provider and
* if we find valid, consistent magic on it, build a geom on it.
*
* There may be cases where the operator would like to put a BSD-geom on
* providers which do not meet all of the requirements. This can be done
* by instead passing the G_TF_INSIST flag, which will override these
* checks.
*
* The final flags value is G_TF_TRANSPARENT, which instructs the method
* to put a geom on top of the provider and configure it to be as transparent
* as possible. This is not really relevant to the BSD method and therefore
* not implemented here.
*/
static struct uuid freebsd_slice = GPT_ENT_TYPE_FREEBSD;
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;
int error, i;
struct g_bsd_softc *ms;
u_int secsize;
struct g_slicer *gsp;
u_char hash[16];
MD5_CTX md5sum;
struct uuid uuid;
g_trace(G_T_TOPOLOGY, "bsd_taste(%s,%s)", mp->name, pp->name);
g_topology_assert();
/* We don't implement transparent inserts. */
if (flags == G_TF_TRANSPARENT)
return (NULL);
/*
* BSD labels are a subclass of the general "slicing" topology so
* a lot of the work can be done by the common "slice" code.
* Create a geom with space for MAXPARTITIONS providers, one consumer
* and a softc structure for us. Specify the provider to attach
* the consumer to and our "start" routine for special requests.
* The provider is opened with mode (1,0,0) so we can do reads
* from it.
*/
gp = g_slice_new(mp, MAXPARTITIONS, pp, &cp, &ms,
sizeof(*ms), g_bsd_start);
if (gp == NULL)
return (NULL);
/* Get the geom_slicer softc from the geom. */
gsp = gp->softc;
/*
* The do...while loop here allows us to have multiple escapes
* using a simple "break". This improves code clarity without
* ending up in deep nesting and without using goto or come from.
*/
do {
/*
* If the provider is an MBR we will only auto attach
* to type 165 slices in the G_TF_NORMAL case. We will
* attach to any other type.
*/
error = g_getattr("MBR::type", cp, &i);
if (!error) {
if (i != 165 && flags == G_TF_NORMAL)
break;
error = g_getattr("MBR::offset", cp, &ms->mbroffset);
if (error)
break;
}
/* Same thing if we are inside a PC98 */
error = g_getattr("PC98::type", cp, &i);
if (!error) {
if (i != 0xc494 && flags == G_TF_NORMAL)
break;
error = g_getattr("PC98::offset", cp, &ms->mbroffset);
if (error)
break;
}
/* Same thing if we are inside a GPT */
error = g_getattr("GPT::type", cp, &uuid);
if (!error) {
if (memcmp(&uuid, &freebsd_slice, sizeof(uuid)) != 0 &&
flags == G_TF_NORMAL)
break;
}
/* Get sector size, we need it to read data. */
secsize = cp->provider->sectorsize;
if (secsize < 512)
break;
/* First look for a label at the start of the second sector. */
error = g_bsd_try(gp, gsp, cp, secsize, ms, secsize);
/*
* If sector size is not 512 the label still can be at
* offset 512, not at the start of the second sector. At least
* it's true for labels created by the FreeBSD's bsdlabel(8).
*/
if (error && secsize != HISTORIC_LABEL_OFFSET)
error = g_bsd_try(gp, gsp, cp, secsize, ms,
HISTORIC_LABEL_OFFSET);
/* Next, look for alpha labels */
if (error)
error = g_bsd_try(gp, gsp, cp, secsize, ms,
ALPHA_LABEL_OFFSET);
/* If we didn't find a label, punt. */
if (error)
break;
/*
* In order to avoid recursively attaching to the same
* on-disk label (it's usually visible through the 'c'
* partition) we calculate an MD5 and ask if other BSD's
* below us love that label. If they do, we don't.
*/
MD5Init(&md5sum);
MD5Update(&md5sum, ms->label, sizeof(ms->label));
MD5Final(ms->labelsum, &md5sum);
error = g_getattr("BSD::labelsum", cp, &hash);
if (!error && !bcmp(ms->labelsum, hash, sizeof(hash)))
break;
/*
* Process the found disklabel, and modify our "slice"
* instance to match it, if possible.
*/
error = g_bsd_modify(gp, ms->label);
} while (0);
/* Success or failure, we can close our provider now. */
g_access(cp, -1, 0, 0);
/* If we have configured any providers, return the new geom. */
if (gsp->nprovider > 0) {
g_slice_conf_hot(gp, 0, ms->labeloffset, LABELSIZE,
G_SLICE_HOT_ALLOW, G_SLICE_HOT_DENY, G_SLICE_HOT_CALL);
gsp->hot = g_bsd_hotwrite;
return (gp);
}
/*
* ...else push the "self-destruct" button, by spoiling our own
* consumer. This triggers a call to g_slice_spoiled which will
* dismantle what was setup.
*/
g_slice_spoiled(cp);
return (NULL);
}
struct h0h0 {
struct g_geom *gp;
struct g_bsd_softc *ms;
u_char *label;
int error;
};
static void
g_bsd_callconfig(void *arg, int flag)
{
struct h0h0 *hp;
hp = arg;
hp->error = g_bsd_modify(hp->gp, hp->label);
if (!hp->error)
hp->error = g_bsd_writelabel(hp->gp, NULL);
}
/*
* NB! curthread is user process which GCTL'ed.
*/
static void
g_bsd_config(struct gctl_req *req, struct g_class *mp, char const *verb)
{
u_char *label;
int error;
struct h0h0 h0h0;
struct g_geom *gp;
struct g_slicer *gsp;
struct g_consumer *cp;
struct g_bsd_softc *ms;
g_topology_assert();
gp = gctl_get_geom(req, mp, "geom");
if (gp == NULL)
return;
cp = LIST_FIRST(&gp->consumer);
gsp = gp->softc;
ms = gsp->softc;
if (!strcmp(verb, "read mbroffset")) {
gctl_set_param_err(req, "mbroffset", &ms->mbroffset,
sizeof(ms->mbroffset));
return;
} else if (!strcmp(verb, "write label")) {
label = gctl_get_paraml(req, "label", LABELSIZE);
if (label == NULL)
return;
h0h0.gp = gp;
h0h0.ms = gsp->softc;
h0h0.label = label;
h0h0.error = -1;
/* XXX: Does this reference register with our selfdestruct code ? */
error = g_access(cp, 1, 1, 1);
if (error) {
gctl_error(req, "could not access consumer");
return;
}
g_bsd_callconfig(&h0h0, 0);
error = h0h0.error;
g_access(cp, -1, -1, -1);
} else if (!strcmp(verb, "write bootcode")) {
label = gctl_get_paraml(req, "bootcode", BBSIZE);
if (label == NULL)
return;
/* XXX: Does this reference register with our selfdestruct code ? */
error = g_access(cp, 1, 1, 1);
if (error) {
gctl_error(req, "could not access consumer");
return;
}
error = g_bsd_writelabel(gp, label);
g_access(cp, -1, -1, -1);
} else {
gctl_error(req, "Unknown verb parameter");
}
return;
}
/* Finally, register with GEOM infrastructure. */
static struct g_class g_bsd_class = {
.name = BSD_CLASS_NAME,
.version = G_VERSION,
.taste = g_bsd_taste,
.ctlreq = g_bsd_config,
.dumpconf = g_bsd_dumpconf,
.ioctl = g_bsd_ioctl,
};
DECLARE_GEOM_CLASS(g_bsd_class, g_bsd);