2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2002 Poul-Henning Kamp
5 * Copyright (c) 2002 Networks Associates Technology, Inc.
8 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
9 * and NAI Labs, the Security Research Division of Network Associates, Inc.
10 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
11 * DARPA CHATS research program.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. The names of the authors may not be used to endorse or promote
22 * products derived from this software without specific prior written
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * This is the method for dealing with BSD disklabels. It has been
40 * extensively (by my standards at least) commented, in the vain hope that
41 * it will serve as the source in future copy&paste operations.
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
47 #include <sys/param.h>
48 #include <sys/endian.h>
49 #include <sys/systm.h>
50 #include <sys/sysctl.h>
51 #include <sys/kernel.h>
52 #include <sys/fcntl.h>
55 #include <sys/malloc.h>
57 #include <sys/mutex.h>
59 #include <sys/errno.h>
60 #include <sys/disklabel.h>
65 #include <geom/geom.h>
66 #include <geom/geom_slice.h>
68 FEATURE(geom_bsd, "GEOM BSD disklabels support");
70 #define BSD_CLASS_NAME "BSD"
72 #define ALPHA_LABEL_OFFSET 64
73 #define HISTORIC_LABEL_OFFSET 512
75 #define LABELSIZE (148 + 16 * MAXPARTITIONS)
77 static int g_bsd_once;
79 static void g_bsd_hotwrite(void *arg, int flag);
81 * Our private data about one instance. All the rest is handled by the
82 * slice code and stored in its softc, so this is just the stuff
83 * specific to BSD disklabels.
89 struct disklabel ondisk;
90 u_char label[LABELSIZE];
95 * Modify our slicer to match proposed disklabel, if possible.
96 * This is where we make sure we don't do something stupid.
99 g_bsd_modify(struct g_geom *gp, u_char *label)
102 struct partition *ppp;
103 struct g_slicer *gsp;
104 struct g_consumer *cp;
105 struct g_bsd_softc *ms;
115 error = bsd_disklabel_le_dec(label, &dl, MAXPARTITIONS);
120 /* Get dimensions of our device. */
121 cp = LIST_FIRST(&gp->consumer);
122 secsize = cp->provider->sectorsize;
124 /* ... or a smaller sector size. */
125 if (dl.d_secsize < secsize) {
129 /* ... or a non-multiple sector size. */
130 if (dl.d_secsize % secsize != 0) {
134 /* Historical braindamage... */
135 rawoffset = (off_t)dl.d_partitions[RAW_PART].p_offset * dl.d_secsize;
137 for (i = 0; i < dl.d_npartitions; i++) {
138 ppp = &dl.d_partitions[i];
139 if (ppp->p_size == 0)
141 o = (off_t)ppp->p_offset * dl.d_secsize;
147 if (rawoffset != 0 && (off_t)rawoffset != ms->mbroffset)
148 printf("WARNING: %s expected rawoffset %jd, found %jd\n",
150 (intmax_t)ms->mbroffset/dl.d_secsize,
151 (intmax_t)rawoffset/dl.d_secsize);
153 /* Don't munge open partitions. */
154 for (i = 0; i < dl.d_npartitions; i++) {
155 ppp = &dl.d_partitions[i];
157 o = (off_t)ppp->p_offset * dl.d_secsize;
160 error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
162 (off_t)ppp->p_size * dl.d_secsize,
164 "%s%c", gp->name, 'a' + i);
169 /* Look good, go for it... */
170 for (u = 0; u < gsp->nslice; u++) {
171 ppp = &dl.d_partitions[u];
172 o = (off_t)ppp->p_offset * dl.d_secsize;
175 g_slice_config(gp, u, G_SLICE_CONFIG_SET,
177 (off_t)ppp->p_size * dl.d_secsize,
179 "%s%c", gp->name, 'a' + u);
182 /* Update our softc */
184 if (label != ms->label)
185 bcopy(label, ms->label, LABELSIZE);
186 ms->rawoffset = rawoffset;
189 * In order to avoid recursively attaching to the same
190 * on-disk label (it's usually visible through the 'c'
191 * partition) we calculate an MD5 and ask if other BSD's
192 * below us love that label. If they do, we don't.
195 MD5Update(&md5sum, ms->label, sizeof(ms->label));
196 MD5Final(ms->labelsum, &md5sum);
202 * This is an internal helper function, called multiple times from the taste
203 * function to try to locate a disklabel on the disk. More civilized formats
204 * will not need this, as there is only one possible place on disk to look
205 * for the magic spot.
209 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)
213 struct disklabel *dl;
217 * We need to read entire aligned sectors, and we assume that the
218 * disklabel does not span sectors, so one sector is enough.
220 secoff = offset % secsize;
221 buf = g_read_data(cp, offset - secoff, secsize, NULL);
225 /* Decode into our native format. */
227 error = bsd_disklabel_le_dec(buf + secoff, dl, MAXPARTITIONS);
229 bcopy(buf + secoff, ms->label, LABELSIZE);
231 /* Remember to free the buffer g_read_data() gave us. */
234 ms->labeloffset = offset;
239 * This function writes the current label to disk, possibly updating
240 * the alpha SRM checksum.
244 g_bsd_writelabel(struct g_geom *gp, u_char *bootcode)
248 struct g_consumer *cp;
249 struct g_slicer *gsp;
250 struct g_bsd_softc *ms;
257 cp = LIST_FIRST(&gp->consumer);
258 /* Get sector size, we need it to read data. */
259 secsize = cp->provider->sectorsize;
260 secoff = ms->labeloffset % secsize;
261 if (bootcode == NULL) {
262 buf = g_read_data(cp, ms->labeloffset - secoff, secsize, &error);
265 bcopy(ms->label, buf + secoff, sizeof(ms->label));
268 bcopy(ms->label, buf + ms->labeloffset, sizeof(ms->label));
270 if (ms->labeloffset == ALPHA_LABEL_OFFSET) {
272 for (i = 0; i < 63; i++)
273 sum += le64dec(buf + i * 8);
274 le64enc(buf + 504, sum);
276 if (bootcode == NULL) {
277 error = g_write_data(cp, ms->labeloffset - secoff, buf, secsize);
280 error = g_write_data(cp, 0, bootcode, BBSIZE);
286 * If the user tries to overwrite our disklabel through an open partition
287 * or via a magicwrite config call, we end up here and try to prevent
288 * footshooting as best we can.
291 g_bsd_hotwrite(void *arg, int flag)
295 struct g_slicer *gsp;
297 struct g_bsd_softc *ms;
303 * We should never get canceled, because that would amount to a removal
304 * of the geom while there was outstanding I/O requests.
306 KASSERT(flag != EV_CANCEL, ("g_bsd_hotwrite cancelled"));
308 gp = bp->bio_to->geom;
311 gsl = &gsp->slices[bp->bio_to->index];
312 p = (u_char*)bp->bio_data + ms->labeloffset -
313 (bp->bio_offset + gsl->offset);
314 error = g_bsd_modify(gp, p);
316 g_io_deliver(bp, EPERM);
319 g_slice_finish_hot(bp);
323 g_bsd_start(struct bio *bp)
326 struct g_bsd_softc *ms;
327 struct g_slicer *gsp;
329 gp = bp->bio_to->geom;
332 if (bp->bio_cmd == BIO_GETATTR) {
333 if (g_handleattr(bp, "BSD::labelsum", ms->labelsum,
334 sizeof(ms->labelsum)))
341 * Dump configuration information in XML format.
342 * Notice that the function is called once for the geom and once for each
343 * consumer and provider. We let g_slice_dumpconf() do most of the work.
346 g_bsd_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp)
348 struct g_bsd_softc *ms;
349 struct g_slicer *gsp;
353 g_slice_dumpconf(sb, indent, gp, cp, pp);
354 if (indent != NULL && pp == NULL && cp == NULL) {
355 sbuf_printf(sb, "%s<labeloffset>%jd</labeloffset>\n",
356 indent, (intmax_t)ms->labeloffset);
357 sbuf_printf(sb, "%s<rawoffset>%jd</rawoffset>\n",
358 indent, (intmax_t)ms->rawoffset);
359 sbuf_printf(sb, "%s<mbroffset>%jd</mbroffset>\n",
360 indent, (intmax_t)ms->mbroffset);
361 } else if (pp != NULL) {
363 sbuf_printf(sb, " ty %d",
364 ms->ondisk.d_partitions[pp->index].p_fstype);
366 sbuf_printf(sb, "%s<type>%d</type>\n", indent,
367 ms->ondisk.d_partitions[pp->index].p_fstype);
372 * The taste function is called from the event-handler, with the topology
373 * lock already held and a provider to examine. The flags are unused.
375 * If flags == G_TF_NORMAL, the idea is to take a bite of the provider and
376 * if we find valid, consistent magic on it, build a geom on it.
378 * There may be cases where the operator would like to put a BSD-geom on
379 * providers which do not meet all of the requirements. This can be done
380 * by instead passing the G_TF_INSIST flag, which will override these
383 * The final flags value is G_TF_TRANSPARENT, which instructs the method
384 * to put a geom on top of the provider and configure it to be as transparent
385 * as possible. This is not really relevant to the BSD method and therefore
386 * not implemented here.
389 static struct uuid freebsd_slice = GPT_ENT_TYPE_FREEBSD;
391 static struct g_geom *
392 g_bsd_taste(struct g_class *mp, struct g_provider *pp, int flags)
395 struct g_consumer *cp;
397 struct g_bsd_softc *ms;
399 struct g_slicer *gsp;
404 g_trace(G_T_TOPOLOGY, "bsd_taste(%s,%s)", mp->name, pp->name);
407 /* We don't implement transparent inserts. */
408 if (flags == G_TF_TRANSPARENT)
412 * BSD labels are a subclass of the general "slicing" topology so
413 * a lot of the work can be done by the common "slice" code.
414 * Create a geom with space for MAXPARTITIONS providers, one consumer
415 * and a softc structure for us. Specify the provider to attach
416 * the consumer to and our "start" routine for special requests.
417 * The provider is opened with mode (1,0,0) so we can do reads
420 gp = g_slice_new(mp, MAXPARTITIONS, pp, &cp, &ms,
421 sizeof(*ms), g_bsd_start);
425 /* Get the geom_slicer softc from the geom. */
429 * The do...while loop here allows us to have multiple escapes
430 * using a simple "break". This improves code clarity without
431 * ending up in deep nesting and without using goto or come from.
435 * If the provider is an MBR we will only auto attach
436 * to type 165 slices in the G_TF_NORMAL case. We will
437 * attach to any other type.
439 error = g_getattr("MBR::type", cp, &i);
441 if (i != 165 && flags == G_TF_NORMAL)
443 error = g_getattr("MBR::offset", cp, &ms->mbroffset);
448 /* Same thing if we are inside a GPT */
449 error = g_getattr("GPT::type", cp, &uuid);
451 if (memcmp(&uuid, &freebsd_slice, sizeof(uuid)) != 0 &&
452 flags == G_TF_NORMAL)
456 /* Get sector size, we need it to read data. */
457 secsize = cp->provider->sectorsize;
461 /* First look for a label at the start of the second sector. */
462 error = g_bsd_try(gp, gsp, cp, secsize, ms, secsize);
465 * If sector size is not 512 the label still can be at
466 * offset 512, not at the start of the second sector. At least
467 * it's true for labels created by the FreeBSD's bsdlabel(8).
469 if (error && secsize != HISTORIC_LABEL_OFFSET)
470 error = g_bsd_try(gp, gsp, cp, secsize, ms,
471 HISTORIC_LABEL_OFFSET);
473 /* Next, look for alpha labels */
475 error = g_bsd_try(gp, gsp, cp, secsize, ms,
478 /* If we didn't find a label, punt. */
483 * In order to avoid recursively attaching to the same
484 * on-disk label (it's usually visible through the 'c'
485 * partition) we calculate an MD5 and ask if other BSD's
486 * below us love that label. If they do, we don't.
489 MD5Update(&md5sum, ms->label, sizeof(ms->label));
490 MD5Final(ms->labelsum, &md5sum);
492 error = g_getattr("BSD::labelsum", cp, &hash);
493 if (!error && !bcmp(ms->labelsum, hash, sizeof(hash)))
497 * Process the found disklabel, and modify our "slice"
498 * instance to match it, if possible.
500 error = g_bsd_modify(gp, ms->label);
503 /* Success or failure, we can close our provider now. */
504 g_access(cp, -1, 0, 0);
506 /* If we have configured any providers, return the new geom. */
507 if (gsp->nprovider > 0) {
508 g_slice_conf_hot(gp, 0, ms->labeloffset, LABELSIZE,
509 G_SLICE_HOT_ALLOW, G_SLICE_HOT_DENY, G_SLICE_HOT_CALL);
510 gsp->hot = g_bsd_hotwrite;
514 "WARNING: geom_bsd (geom %s) is deprecated, "
515 "use gpart instead.\n", gp->name);
520 * ...else push the "self-destruct" button, by spoiling our own
521 * consumer. This triggers a call to g_slice_spoiled which will
522 * dismantle what was setup.
530 struct g_bsd_softc *ms;
536 g_bsd_callconfig(void *arg, int flag)
541 hp->error = g_bsd_modify(hp->gp, hp->label);
543 hp->error = g_bsd_writelabel(hp->gp, NULL);
547 * NB! curthread is user process which GCTL'ed.
550 g_bsd_config(struct gctl_req *req, struct g_class *mp, char const *verb)
556 struct g_slicer *gsp;
557 struct g_consumer *cp;
558 struct g_bsd_softc *ms;
561 gp = gctl_get_geom(req, mp, "geom");
564 cp = LIST_FIRST(&gp->consumer);
567 if (!strcmp(verb, "read mbroffset")) {
568 gctl_set_param_err(req, "mbroffset", &ms->mbroffset,
569 sizeof(ms->mbroffset));
571 } else if (!strcmp(verb, "write label")) {
572 label = gctl_get_paraml(req, "label", LABELSIZE);
576 h0h0.ms = gsp->softc;
579 /* XXX: Does this reference register with our selfdestruct code ? */
580 error = g_access(cp, 1, 1, 1);
582 gctl_error(req, "could not access consumer");
585 g_bsd_callconfig(&h0h0, 0);
587 g_access(cp, -1, -1, -1);
588 } else if (!strcmp(verb, "write bootcode")) {
589 label = gctl_get_paraml(req, "bootcode", BBSIZE);
592 /* XXX: Does this reference register with our selfdestruct code ? */
593 error = g_access(cp, 1, 1, 1);
595 gctl_error(req, "could not access consumer");
598 error = g_bsd_writelabel(gp, label);
599 g_access(cp, -1, -1, -1);
601 gctl_error(req, "Unknown verb parameter");
607 /* Finally, register with GEOM infrastructure. */
608 static struct g_class g_bsd_class = {
609 .name = BSD_CLASS_NAME,
610 .version = G_VERSION,
611 .taste = g_bsd_taste,
612 .ctlreq = g_bsd_config,
613 .dumpconf = g_bsd_dumpconf,
616 DECLARE_GEOM_CLASS(g_bsd_class, g_bsd);
617 MODULE_VERSION(geom_bsd, 0);