xref: /freebsd/sys/geom/shsec/g_shsec.c (revision ccfd87fe2ac0e2e6aeb1911a7d7cce6712a8564f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/bio.h>
39 #include <sys/sbuf.h>
40 #include <sys/sysctl.h>
41 #include <sys/malloc.h>
42 #include <vm/uma.h>
43 #include <geom/geom.h>
44 #include <geom/geom_dbg.h>
45 #include <geom/shsec/g_shsec.h>
46 
47 FEATURE(geom_shsec, "GEOM shared secret device support");
48 
49 static MALLOC_DEFINE(M_SHSEC, "shsec_data", "GEOM_SHSEC Data");
50 
51 static uma_zone_t g_shsec_zone;
52 
53 static int g_shsec_destroy(struct g_shsec_softc *sc, boolean_t force);
54 static int g_shsec_destroy_geom(struct gctl_req *req, struct g_class *mp,
55     struct g_geom *gp);
56 
57 static g_taste_t g_shsec_taste;
58 static g_ctl_req_t g_shsec_config;
59 static g_dumpconf_t g_shsec_dumpconf;
60 static g_init_t g_shsec_init;
61 static g_fini_t g_shsec_fini;
62 
63 struct g_class g_shsec_class = {
64 	.name = G_SHSEC_CLASS_NAME,
65 	.version = G_VERSION,
66 	.ctlreq = g_shsec_config,
67 	.taste = g_shsec_taste,
68 	.destroy_geom = g_shsec_destroy_geom,
69 	.init = g_shsec_init,
70 	.fini = g_shsec_fini
71 };
72 
73 SYSCTL_DECL(_kern_geom);
74 static SYSCTL_NODE(_kern_geom, OID_AUTO, shsec, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
75     "GEOM_SHSEC stuff");
76 static u_int g_shsec_debug;
77 SYSCTL_UINT(_kern_geom_shsec, OID_AUTO, debug, CTLFLAG_RWTUN, &g_shsec_debug, 0,
78     "Debug level");
79 static u_long g_shsec_maxmem;
80 SYSCTL_ULONG(_kern_geom_shsec, OID_AUTO, maxmem,
81     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &g_shsec_maxmem,
82     0, "Maximum memory that can be allocated for I/O (in bytes)");
83 static u_int g_shsec_alloc_failed = 0;
84 SYSCTL_UINT(_kern_geom_shsec, OID_AUTO, alloc_failed, CTLFLAG_RD,
85     &g_shsec_alloc_failed, 0, "How many times I/O allocation failed");
86 
87 /*
88  * Greatest Common Divisor.
89  */
90 static u_int
91 gcd(u_int a, u_int b)
92 {
93 	u_int c;
94 
95 	while (b != 0) {
96 		c = a;
97 		a = b;
98 		b = (c % b);
99 	}
100 	return (a);
101 }
102 
103 /*
104  * Least Common Multiple.
105  */
106 static u_int
107 lcm(u_int a, u_int b)
108 {
109 
110 	return ((a * b) / gcd(a, b));
111 }
112 
113 static void
114 g_shsec_init(struct g_class *mp __unused)
115 {
116 
117 	g_shsec_maxmem = maxphys * 100;
118 	TUNABLE_ULONG_FETCH("kern.geom.shsec.maxmem,", &g_shsec_maxmem);
119 	g_shsec_zone = uma_zcreate("g_shsec_zone", maxphys, NULL, NULL, NULL,
120 	    NULL, 0, 0);
121 	g_shsec_maxmem -= g_shsec_maxmem % maxphys;
122 	uma_zone_set_max(g_shsec_zone, g_shsec_maxmem / maxphys);
123 }
124 
125 static void
126 g_shsec_fini(struct g_class *mp __unused)
127 {
128 
129 	uma_zdestroy(g_shsec_zone);
130 }
131 
132 /*
133  * Return the number of valid disks.
134  */
135 static u_int
136 g_shsec_nvalid(struct g_shsec_softc *sc)
137 {
138 	u_int i, no;
139 
140 	no = 0;
141 	for (i = 0; i < sc->sc_ndisks; i++) {
142 		if (sc->sc_disks[i] != NULL)
143 			no++;
144 	}
145 
146 	return (no);
147 }
148 
149 static void
150 g_shsec_remove_disk(struct g_consumer *cp)
151 {
152 	struct g_shsec_softc *sc;
153 	u_int no;
154 
155 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
156 	sc = (struct g_shsec_softc *)cp->private;
157 	KASSERT(sc != NULL, ("NULL sc in %s.", __func__));
158 	no = cp->index;
159 
160 	G_SHSEC_DEBUG(0, "Disk %s removed from %s.", cp->provider->name,
161 	    sc->sc_name);
162 
163 	sc->sc_disks[no] = NULL;
164 	if (sc->sc_provider != NULL) {
165 		g_wither_provider(sc->sc_provider, ENXIO);
166 		sc->sc_provider = NULL;
167 		G_SHSEC_DEBUG(0, "Device %s removed.", sc->sc_name);
168 	}
169 
170 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
171 		return;
172 	g_detach(cp);
173 	g_destroy_consumer(cp);
174 }
175 
176 static void
177 g_shsec_orphan(struct g_consumer *cp)
178 {
179 	struct g_shsec_softc *sc;
180 	struct g_geom *gp;
181 
182 	g_topology_assert();
183 	gp = cp->geom;
184 	sc = gp->softc;
185 	if (sc == NULL)
186 		return;
187 
188 	g_shsec_remove_disk(cp);
189 	/* If there are no valid disks anymore, remove device. */
190 	if (LIST_EMPTY(&gp->consumer))
191 		g_shsec_destroy(sc, 1);
192 }
193 
194 static int
195 g_shsec_access(struct g_provider *pp, int dr, int dw, int de)
196 {
197 	struct g_consumer *cp1, *cp2, *tmp;
198 	struct g_shsec_softc *sc;
199 	struct g_geom *gp;
200 	int error;
201 
202 	gp = pp->geom;
203 	sc = gp->softc;
204 
205 	/* On first open, grab an extra "exclusive" bit */
206 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
207 		de++;
208 	/* ... and let go of it on last close */
209 	if ((pp->acr + dr) == 0 && (pp->acw + dw) == 0 && (pp->ace + de) == 0)
210 		de--;
211 
212 	error = ENXIO;
213 	LIST_FOREACH_SAFE(cp1, &gp->consumer, consumer, tmp) {
214 		error = g_access(cp1, dr, dw, de);
215 		if (error != 0)
216 			goto fail;
217 		if (cp1->acr == 0 && cp1->acw == 0 && cp1->ace == 0 &&
218 		    cp1->flags & G_CF_ORPHAN) {
219 			g_detach(cp1);
220 			g_destroy_consumer(cp1);
221 		}
222 	}
223 
224 	/* If there are no valid disks anymore, remove device. */
225 	if (LIST_EMPTY(&gp->consumer))
226 		g_shsec_destroy(sc, 1);
227 
228 	return (error);
229 
230 fail:
231 	/* If we fail here, backout all previous changes. */
232 	LIST_FOREACH(cp2, &gp->consumer, consumer) {
233 		if (cp1 == cp2)
234 			break;
235 		g_access(cp2, -dr, -dw, -de);
236 	}
237 	return (error);
238 }
239 
240 static void
241 g_shsec_xor1(uint32_t *src, uint32_t *dst, ssize_t len)
242 {
243 
244 	for (; len > 0; len -= sizeof(uint32_t), dst++)
245 		*dst = *dst ^ *src++;
246 	KASSERT(len == 0, ("len != 0 (len=%zd)", len));
247 }
248 
249 static void
250 g_shsec_done(struct bio *bp)
251 {
252 	struct bio *pbp;
253 
254 	pbp = bp->bio_parent;
255 	if (bp->bio_error == 0)
256 		G_SHSEC_LOGREQ(2, bp, "Request done.");
257 	else {
258 		G_SHSEC_LOGREQ(0, bp, "Request failed (error=%d).",
259 		    bp->bio_error);
260 		if (pbp->bio_error == 0)
261 			pbp->bio_error = bp->bio_error;
262 	}
263 	if (pbp->bio_cmd == BIO_READ) {
264 		if ((pbp->bio_pflags & G_SHSEC_BFLAG_FIRST) != 0) {
265 			bcopy(bp->bio_data, pbp->bio_data, pbp->bio_length);
266 			pbp->bio_pflags = 0;
267 		} else {
268 			g_shsec_xor1((uint32_t *)bp->bio_data,
269 			    (uint32_t *)pbp->bio_data,
270 			    (ssize_t)pbp->bio_length);
271 		}
272 	}
273 	if (bp->bio_data != NULL) {
274 		explicit_bzero(bp->bio_data, bp->bio_length);
275 		uma_zfree(g_shsec_zone, bp->bio_data);
276 	}
277 	g_destroy_bio(bp);
278 	pbp->bio_inbed++;
279 	if (pbp->bio_children == pbp->bio_inbed) {
280 		pbp->bio_completed = pbp->bio_length;
281 		g_io_deliver(pbp, pbp->bio_error);
282 	}
283 }
284 
285 static void
286 g_shsec_xor2(uint32_t *rand, uint32_t *dst, ssize_t len)
287 {
288 
289 	for (; len > 0; len -= sizeof(uint32_t), dst++) {
290 		*rand = arc4random();
291 		*dst = *dst ^ *rand++;
292 	}
293 	KASSERT(len == 0, ("len != 0 (len=%zd)", len));
294 }
295 
296 static void
297 g_shsec_start(struct bio *bp)
298 {
299 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
300 	struct g_shsec_softc *sc;
301 	struct bio *cbp;
302 	uint32_t *dst;
303 	ssize_t len;
304 	u_int no;
305 	int error;
306 
307 	sc = bp->bio_to->geom->softc;
308 	/*
309 	 * If sc == NULL, provider's error should be set and g_shsec_start()
310 	 * should not be called at all.
311 	 */
312 	KASSERT(sc != NULL,
313 	    ("Provider's error should be set (error=%d)(device=%s).",
314 	    bp->bio_to->error, bp->bio_to->name));
315 
316 	G_SHSEC_LOGREQ(2, bp, "Request received.");
317 
318 	switch (bp->bio_cmd) {
319 	case BIO_READ:
320 	case BIO_WRITE:
321 	case BIO_FLUSH:
322 	case BIO_SPEEDUP:
323 		/*
324 		 * Only those requests are supported.
325 		 */
326 		break;
327 	case BIO_DELETE:
328 	case BIO_GETATTR:
329 		/* To which provider it should be delivered? */
330 	default:
331 		g_io_deliver(bp, EOPNOTSUPP);
332 		return;
333 	}
334 
335 	/*
336 	 * Allocate all bios first and calculate XOR.
337 	 */
338 	dst = NULL;
339 	len = bp->bio_length;
340 	if (bp->bio_cmd == BIO_READ)
341 		bp->bio_pflags = G_SHSEC_BFLAG_FIRST;
342 	for (no = 0; no < sc->sc_ndisks; no++) {
343 		cbp = g_clone_bio(bp);
344 		if (cbp == NULL) {
345 			error = ENOMEM;
346 			goto failure;
347 		}
348 		TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
349 
350 		/*
351 		 * Fill in the component buf structure.
352 		 */
353 		cbp->bio_done = g_shsec_done;
354 		cbp->bio_caller2 = sc->sc_disks[no];
355 		if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) {
356 			cbp->bio_data = uma_zalloc(g_shsec_zone, M_NOWAIT);
357 			if (cbp->bio_data == NULL) {
358 				g_shsec_alloc_failed++;
359 				error = ENOMEM;
360 				goto failure;
361 			}
362 			if (bp->bio_cmd == BIO_WRITE) {
363 				if (no == 0) {
364 					dst = (uint32_t *)cbp->bio_data;
365 					bcopy(bp->bio_data, dst, len);
366 				} else {
367 					g_shsec_xor2((uint32_t *)cbp->bio_data,
368 					    dst, len);
369 				}
370 			}
371 		}
372 	}
373 	/*
374 	 * Fire off all allocated requests!
375 	 */
376 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
377 		struct g_consumer *cp;
378 
379 		TAILQ_REMOVE(&queue, cbp, bio_queue);
380 		cp = cbp->bio_caller2;
381 		cbp->bio_caller2 = NULL;
382 		cbp->bio_to = cp->provider;
383 		G_SHSEC_LOGREQ(2, cbp, "Sending request.");
384 		g_io_request(cbp, cp);
385 	}
386 	return;
387 failure:
388 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
389 		TAILQ_REMOVE(&queue, cbp, bio_queue);
390 		bp->bio_children--;
391 		if (cbp->bio_data != NULL) {
392 			explicit_bzero(cbp->bio_data, cbp->bio_length);
393 			uma_zfree(g_shsec_zone, cbp->bio_data);
394 		}
395 		g_destroy_bio(cbp);
396 	}
397 	if (bp->bio_error == 0)
398 		bp->bio_error = error;
399 	g_io_deliver(bp, bp->bio_error);
400 }
401 
402 static void
403 g_shsec_check_and_run(struct g_shsec_softc *sc)
404 {
405 	off_t mediasize, ms;
406 	u_int no, sectorsize = 0;
407 
408 	if (g_shsec_nvalid(sc) != sc->sc_ndisks)
409 		return;
410 
411 	sc->sc_provider = g_new_providerf(sc->sc_geom, "shsec/%s", sc->sc_name);
412 	/*
413 	 * Find the smallest disk.
414 	 */
415 	mediasize = sc->sc_disks[0]->provider->mediasize;
416 	mediasize -= sc->sc_disks[0]->provider->sectorsize;
417 	sectorsize = sc->sc_disks[0]->provider->sectorsize;
418 	for (no = 1; no < sc->sc_ndisks; no++) {
419 		ms = sc->sc_disks[no]->provider->mediasize;
420 		ms -= sc->sc_disks[no]->provider->sectorsize;
421 		if (ms < mediasize)
422 			mediasize = ms;
423 		sectorsize = lcm(sectorsize,
424 		    sc->sc_disks[no]->provider->sectorsize);
425 	}
426 	sc->sc_provider->sectorsize = sectorsize;
427 	sc->sc_provider->mediasize = mediasize;
428 	g_error_provider(sc->sc_provider, 0);
429 
430 	G_SHSEC_DEBUG(0, "Device %s activated.", sc->sc_name);
431 }
432 
433 static int
434 g_shsec_read_metadata(struct g_consumer *cp, struct g_shsec_metadata *md)
435 {
436 	struct g_provider *pp;
437 	u_char *buf;
438 	int error;
439 
440 	g_topology_assert();
441 
442 	error = g_access(cp, 1, 0, 0);
443 	if (error != 0)
444 		return (error);
445 	pp = cp->provider;
446 	g_topology_unlock();
447 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
448 	    &error);
449 	g_topology_lock();
450 	g_access(cp, -1, 0, 0);
451 	if (buf == NULL)
452 		return (error);
453 
454 	/* Decode metadata. */
455 	shsec_metadata_decode(buf, md);
456 	g_free(buf);
457 
458 	return (0);
459 }
460 
461 /*
462  * Add disk to given device.
463  */
464 static int
465 g_shsec_add_disk(struct g_shsec_softc *sc, struct g_provider *pp, u_int no)
466 {
467 	struct g_consumer *cp, *fcp;
468 	struct g_geom *gp;
469 	struct g_shsec_metadata md;
470 	int error;
471 
472 	/* Metadata corrupted? */
473 	if (no >= sc->sc_ndisks)
474 		return (EINVAL);
475 
476 	/* Check if disk is not already attached. */
477 	if (sc->sc_disks[no] != NULL)
478 		return (EEXIST);
479 
480 	gp = sc->sc_geom;
481 	fcp = LIST_FIRST(&gp->consumer);
482 
483 	cp = g_new_consumer(gp);
484 	error = g_attach(cp, pp);
485 	if (error != 0) {
486 		g_destroy_consumer(cp);
487 		return (error);
488 	}
489 
490 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0)) {
491 		error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
492 		if (error != 0) {
493 			g_detach(cp);
494 			g_destroy_consumer(cp);
495 			return (error);
496 		}
497 	}
498 
499 	/* Reread metadata. */
500 	error = g_shsec_read_metadata(cp, &md);
501 	if (error != 0)
502 		goto fail;
503 
504 	if (strcmp(md.md_magic, G_SHSEC_MAGIC) != 0 ||
505 	    strcmp(md.md_name, sc->sc_name) != 0 || md.md_id != sc->sc_id) {
506 		G_SHSEC_DEBUG(0, "Metadata on %s changed.", pp->name);
507 		goto fail;
508 	}
509 
510 	cp->private = sc;
511 	cp->index = no;
512 	sc->sc_disks[no] = cp;
513 
514 	G_SHSEC_DEBUG(0, "Disk %s attached to %s.", pp->name, sc->sc_name);
515 
516 	g_shsec_check_and_run(sc);
517 
518 	return (0);
519 fail:
520 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0))
521 		g_access(cp, -fcp->acr, -fcp->acw, -fcp->ace);
522 	g_detach(cp);
523 	g_destroy_consumer(cp);
524 	return (error);
525 }
526 
527 static struct g_geom *
528 g_shsec_create(struct g_class *mp, const struct g_shsec_metadata *md)
529 {
530 	struct g_shsec_softc *sc;
531 	struct g_geom *gp;
532 	u_int no;
533 
534 	G_SHSEC_DEBUG(1, "Creating device %s (id=%u).", md->md_name, md->md_id);
535 
536 	/* Two disks is minimum. */
537 	if (md->md_all < 2) {
538 		G_SHSEC_DEBUG(0, "Too few disks defined for %s.", md->md_name);
539 		return (NULL);
540 	}
541 
542 	/* Check for duplicate unit */
543 	LIST_FOREACH(gp, &mp->geom, geom) {
544 		sc = gp->softc;
545 		if (sc != NULL && strcmp(sc->sc_name, md->md_name) == 0) {
546 			G_SHSEC_DEBUG(0, "Device %s already configured.",
547 			    sc->sc_name);
548 			return (NULL);
549 		}
550 	}
551 	gp = g_new_geomf(mp, "%s", md->md_name);
552 	sc = malloc(sizeof(*sc), M_SHSEC, M_WAITOK | M_ZERO);
553 	gp->start = g_shsec_start;
554 	gp->spoiled = g_shsec_orphan;
555 	gp->orphan = g_shsec_orphan;
556 	gp->access = g_shsec_access;
557 	gp->dumpconf = g_shsec_dumpconf;
558 
559 	sc->sc_id = md->md_id;
560 	sc->sc_ndisks = md->md_all;
561 	sc->sc_disks = malloc(sizeof(struct g_consumer *) * sc->sc_ndisks,
562 	    M_SHSEC, M_WAITOK | M_ZERO);
563 	for (no = 0; no < sc->sc_ndisks; no++)
564 		sc->sc_disks[no] = NULL;
565 
566 	gp->softc = sc;
567 	sc->sc_geom = gp;
568 	sc->sc_provider = NULL;
569 
570 	G_SHSEC_DEBUG(0, "Device %s created (id=%u).", sc->sc_name, sc->sc_id);
571 
572 	return (gp);
573 }
574 
575 static int
576 g_shsec_destroy(struct g_shsec_softc *sc, boolean_t force)
577 {
578 	struct g_provider *pp;
579 	struct g_geom *gp;
580 	u_int no;
581 
582 	g_topology_assert();
583 
584 	if (sc == NULL)
585 		return (ENXIO);
586 
587 	pp = sc->sc_provider;
588 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
589 		if (force) {
590 			G_SHSEC_DEBUG(0, "Device %s is still open, so it "
591 			    "can't be definitely removed.", pp->name);
592 		} else {
593 			G_SHSEC_DEBUG(1,
594 			    "Device %s is still open (r%dw%de%d).", pp->name,
595 			    pp->acr, pp->acw, pp->ace);
596 			return (EBUSY);
597 		}
598 	}
599 
600 	for (no = 0; no < sc->sc_ndisks; no++) {
601 		if (sc->sc_disks[no] != NULL)
602 			g_shsec_remove_disk(sc->sc_disks[no]);
603 	}
604 
605 	gp = sc->sc_geom;
606 	gp->softc = NULL;
607 	KASSERT(sc->sc_provider == NULL, ("Provider still exists? (device=%s)",
608 	    gp->name));
609 	free(sc->sc_disks, M_SHSEC);
610 	free(sc, M_SHSEC);
611 
612 	pp = LIST_FIRST(&gp->provider);
613 	if (pp == NULL || (pp->acr == 0 && pp->acw == 0 && pp->ace == 0))
614 		G_SHSEC_DEBUG(0, "Device %s destroyed.", gp->name);
615 
616 	g_wither_geom(gp, ENXIO);
617 
618 	return (0);
619 }
620 
621 static int
622 g_shsec_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
623     struct g_geom *gp)
624 {
625 	struct g_shsec_softc *sc;
626 
627 	sc = gp->softc;
628 	return (g_shsec_destroy(sc, 0));
629 }
630 
631 static struct g_geom *
632 g_shsec_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
633 {
634 	struct g_shsec_metadata md;
635 	struct g_shsec_softc *sc;
636 	struct g_consumer *cp;
637 	struct g_geom *gp;
638 	int error;
639 
640 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
641 	g_topology_assert();
642 
643 	/* Skip providers that are already open for writing. */
644 	if (pp->acw > 0)
645 		return (NULL);
646 
647 	G_SHSEC_DEBUG(3, "Tasting %s.", pp->name);
648 
649 	gp = g_new_geomf(mp, "shsec:taste");
650 	gp->start = g_shsec_start;
651 	gp->access = g_shsec_access;
652 	gp->orphan = g_shsec_orphan;
653 	cp = g_new_consumer(gp);
654 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
655 	error = g_attach(cp, pp);
656 	if (error == 0) {
657 		error = g_shsec_read_metadata(cp, &md);
658 		g_detach(cp);
659 	}
660 	g_destroy_consumer(cp);
661 	g_destroy_geom(gp);
662 	if (error != 0)
663 		return (NULL);
664 	gp = NULL;
665 
666 	if (strcmp(md.md_magic, G_SHSEC_MAGIC) != 0)
667 		return (NULL);
668 	if (md.md_version > G_SHSEC_VERSION) {
669 		G_SHSEC_DEBUG(0, "Kernel module is too old to handle %s.\n",
670 		    pp->name);
671 		return (NULL);
672 	}
673 	/*
674 	 * Backward compatibility:
675 	 */
676 	/* There was no md_provsize field in earlier versions of metadata. */
677 	if (md.md_version < 1)
678 		md.md_provsize = pp->mediasize;
679 
680 	if (md.md_provider[0] != '\0' &&
681 	    !g_compare_names(md.md_provider, pp->name))
682 		return (NULL);
683 	if (md.md_provsize != pp->mediasize)
684 		return (NULL);
685 
686 	/*
687 	 * Let's check if device already exists.
688 	 */
689 	sc = NULL;
690 	LIST_FOREACH(gp, &mp->geom, geom) {
691 		sc = gp->softc;
692 		if (sc == NULL)
693 			continue;
694 		if (strcmp(md.md_name, sc->sc_name) != 0)
695 			continue;
696 		if (md.md_id != sc->sc_id)
697 			continue;
698 		break;
699 	}
700 	if (gp != NULL) {
701 		G_SHSEC_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
702 		error = g_shsec_add_disk(sc, pp, md.md_no);
703 		if (error != 0) {
704 			G_SHSEC_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
705 			    pp->name, gp->name, error);
706 			return (NULL);
707 		}
708 	} else {
709 		gp = g_shsec_create(mp, &md);
710 		if (gp == NULL) {
711 			G_SHSEC_DEBUG(0, "Cannot create device %s.", md.md_name);
712 			return (NULL);
713 		}
714 		sc = gp->softc;
715 		G_SHSEC_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
716 		error = g_shsec_add_disk(sc, pp, md.md_no);
717 		if (error != 0) {
718 			G_SHSEC_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
719 			    pp->name, gp->name, error);
720 			g_shsec_destroy(sc, 1);
721 			return (NULL);
722 		}
723 	}
724 	return (gp);
725 }
726 
727 static struct g_shsec_softc *
728 g_shsec_find_device(struct g_class *mp, const char *name)
729 {
730 	struct g_shsec_softc *sc;
731 	struct g_geom *gp;
732 
733 	LIST_FOREACH(gp, &mp->geom, geom) {
734 		sc = gp->softc;
735 		if (sc == NULL)
736 			continue;
737 		if (strcmp(sc->sc_name, name) == 0)
738 			return (sc);
739 	}
740 	return (NULL);
741 }
742 
743 static void
744 g_shsec_ctl_destroy(struct gctl_req *req, struct g_class *mp)
745 {
746 	struct g_shsec_softc *sc;
747 	int *force, *nargs, error;
748 	const char *name;
749 	char param[16];
750 	u_int i;
751 
752 	g_topology_assert();
753 
754 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
755 	if (nargs == NULL) {
756 		gctl_error(req, "No '%s' argument.", "nargs");
757 		return;
758 	}
759 	if (*nargs <= 0) {
760 		gctl_error(req, "Missing device(s).");
761 		return;
762 	}
763 	force = gctl_get_paraml(req, "force", sizeof(*force));
764 	if (force == NULL) {
765 		gctl_error(req, "No '%s' argument.", "force");
766 		return;
767 	}
768 
769 	for (i = 0; i < (u_int)*nargs; i++) {
770 		snprintf(param, sizeof(param), "arg%u", i);
771 		name = gctl_get_asciiparam(req, param);
772 		if (name == NULL) {
773 			gctl_error(req, "No 'arg%u' argument.", i);
774 			return;
775 		}
776 		sc = g_shsec_find_device(mp, name);
777 		if (sc == NULL) {
778 			gctl_error(req, "No such device: %s.", name);
779 			return;
780 		}
781 		error = g_shsec_destroy(sc, *force);
782 		if (error != 0) {
783 			gctl_error(req, "Cannot destroy device %s (error=%d).",
784 			    sc->sc_name, error);
785 			return;
786 		}
787 	}
788 }
789 
790 static void
791 g_shsec_config(struct gctl_req *req, struct g_class *mp, const char *verb)
792 {
793 	uint32_t *version;
794 
795 	g_topology_assert();
796 
797 	version = gctl_get_paraml(req, "version", sizeof(*version));
798 	if (version == NULL) {
799 		gctl_error(req, "No '%s' argument.", "version");
800 		return;
801 	}
802 	if (*version != G_SHSEC_VERSION) {
803 		gctl_error(req, "Userland and kernel parts are out of sync.");
804 		return;
805 	}
806 
807 	if (strcmp(verb, "stop") == 0) {
808 		g_shsec_ctl_destroy(req, mp);
809 		return;
810 	}
811 
812 	gctl_error(req, "Unknown verb.");
813 }
814 
815 static void
816 g_shsec_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
817     struct g_consumer *cp, struct g_provider *pp)
818 {
819 	struct g_shsec_softc *sc;
820 
821 	sc = gp->softc;
822 	if (sc == NULL)
823 		return;
824 	if (pp != NULL) {
825 		/* Nothing here. */
826 	} else if (cp != NULL) {
827 		sbuf_printf(sb, "%s<Number>%u</Number>\n", indent,
828 		    (u_int)cp->index);
829 	} else {
830 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
831 		sbuf_printf(sb, "%s<Status>Total=%u, Online=%u</Status>\n",
832 		    indent, sc->sc_ndisks, g_shsec_nvalid(sc));
833 		sbuf_printf(sb, "%s<State>", indent);
834 		if (sc->sc_provider != NULL && sc->sc_provider->error == 0)
835 			sbuf_printf(sb, "UP");
836 		else
837 			sbuf_printf(sb, "DOWN");
838 		sbuf_printf(sb, "</State>\n");
839 	}
840 }
841 
842 DECLARE_GEOM_CLASS(g_shsec_class, g_shsec);
843 MODULE_VERSION(geom_shsec, 0);
844