xref: /freebsd/sys/geom/shsec/g_shsec.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
32 #include <sys/module.h>
33 #include <sys/lock.h>
34 #include <sys/mutex.h>
35 #include <sys/bio.h>
36 #include <sys/sbuf.h>
37 #include <sys/sysctl.h>
38 #include <sys/malloc.h>
39 #include <vm/uma.h>
40 #include <geom/geom.h>
41 #include <geom/geom_dbg.h>
42 #include <geom/shsec/g_shsec.h>
43 
44 FEATURE(geom_shsec, "GEOM shared secret device support");
45 
46 static MALLOC_DEFINE(M_SHSEC, "shsec_data", "GEOM_SHSEC Data");
47 
48 static uma_zone_t g_shsec_zone;
49 
50 static int g_shsec_destroy(struct g_shsec_softc *sc, boolean_t force);
51 static int g_shsec_destroy_geom(struct gctl_req *req, struct g_class *mp,
52     struct g_geom *gp);
53 
54 static g_taste_t g_shsec_taste;
55 static g_ctl_req_t g_shsec_config;
56 static g_dumpconf_t g_shsec_dumpconf;
57 static g_init_t g_shsec_init;
58 static g_fini_t g_shsec_fini;
59 
60 struct g_class g_shsec_class = {
61 	.name = G_SHSEC_CLASS_NAME,
62 	.version = G_VERSION,
63 	.ctlreq = g_shsec_config,
64 	.taste = g_shsec_taste,
65 	.destroy_geom = g_shsec_destroy_geom,
66 	.init = g_shsec_init,
67 	.fini = g_shsec_fini
68 };
69 
70 SYSCTL_DECL(_kern_geom);
71 static SYSCTL_NODE(_kern_geom, OID_AUTO, shsec, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
72     "GEOM_SHSEC stuff");
73 static u_int g_shsec_debug;
74 SYSCTL_UINT(_kern_geom_shsec, OID_AUTO, debug, CTLFLAG_RWTUN, &g_shsec_debug, 0,
75     "Debug level");
76 static u_long g_shsec_maxmem;
77 SYSCTL_ULONG(_kern_geom_shsec, OID_AUTO, maxmem,
78     CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &g_shsec_maxmem,
79     0, "Maximum memory that can be allocated for I/O (in bytes)");
80 static u_int g_shsec_alloc_failed = 0;
81 SYSCTL_UINT(_kern_geom_shsec, OID_AUTO, alloc_failed, CTLFLAG_RD,
82     &g_shsec_alloc_failed, 0, "How many times I/O allocation failed");
83 
84 /*
85  * Greatest Common Divisor.
86  */
87 static u_int
88 gcd(u_int a, u_int b)
89 {
90 	u_int c;
91 
92 	while (b != 0) {
93 		c = a;
94 		a = b;
95 		b = (c % b);
96 	}
97 	return (a);
98 }
99 
100 /*
101  * Least Common Multiple.
102  */
103 static u_int
104 lcm(u_int a, u_int b)
105 {
106 
107 	return ((a * b) / gcd(a, b));
108 }
109 
110 static void
111 g_shsec_init(struct g_class *mp __unused)
112 {
113 
114 	g_shsec_maxmem = maxphys * 100;
115 	TUNABLE_ULONG_FETCH("kern.geom.shsec.maxmem,", &g_shsec_maxmem);
116 	g_shsec_zone = uma_zcreate("g_shsec_zone", maxphys, NULL, NULL, NULL,
117 	    NULL, 0, 0);
118 	g_shsec_maxmem -= g_shsec_maxmem % maxphys;
119 	uma_zone_set_max(g_shsec_zone, g_shsec_maxmem / maxphys);
120 }
121 
122 static void
123 g_shsec_fini(struct g_class *mp __unused)
124 {
125 
126 	uma_zdestroy(g_shsec_zone);
127 }
128 
129 /*
130  * Return the number of valid disks.
131  */
132 static u_int
133 g_shsec_nvalid(struct g_shsec_softc *sc)
134 {
135 	u_int i, no;
136 
137 	no = 0;
138 	for (i = 0; i < sc->sc_ndisks; i++) {
139 		if (sc->sc_disks[i] != NULL)
140 			no++;
141 	}
142 
143 	return (no);
144 }
145 
146 static void
147 g_shsec_remove_disk(struct g_consumer *cp)
148 {
149 	struct g_shsec_softc *sc;
150 	u_int no;
151 
152 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
153 	sc = (struct g_shsec_softc *)cp->private;
154 	KASSERT(sc != NULL, ("NULL sc in %s.", __func__));
155 	no = cp->index;
156 
157 	G_SHSEC_DEBUG(0, "Disk %s removed from %s.", cp->provider->name,
158 	    sc->sc_name);
159 
160 	sc->sc_disks[no] = NULL;
161 	if (sc->sc_provider != NULL) {
162 		g_wither_provider(sc->sc_provider, ENXIO);
163 		sc->sc_provider = NULL;
164 		G_SHSEC_DEBUG(0, "Device %s removed.", sc->sc_name);
165 	}
166 
167 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
168 		return;
169 	g_detach(cp);
170 	g_destroy_consumer(cp);
171 }
172 
173 static void
174 g_shsec_orphan(struct g_consumer *cp)
175 {
176 	struct g_shsec_softc *sc;
177 	struct g_geom *gp;
178 
179 	g_topology_assert();
180 	gp = cp->geom;
181 	sc = gp->softc;
182 	if (sc == NULL)
183 		return;
184 
185 	g_shsec_remove_disk(cp);
186 	/* If there are no valid disks anymore, remove device. */
187 	if (LIST_EMPTY(&gp->consumer))
188 		g_shsec_destroy(sc, 1);
189 }
190 
191 static int
192 g_shsec_access(struct g_provider *pp, int dr, int dw, int de)
193 {
194 	struct g_consumer *cp1, *cp2, *tmp;
195 	struct g_shsec_softc *sc;
196 	struct g_geom *gp;
197 	int error;
198 
199 	gp = pp->geom;
200 	sc = gp->softc;
201 
202 	/* On first open, grab an extra "exclusive" bit */
203 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
204 		de++;
205 	/* ... and let go of it on last close */
206 	if ((pp->acr + dr) == 0 && (pp->acw + dw) == 0 && (pp->ace + de) == 0)
207 		de--;
208 
209 	error = ENXIO;
210 	LIST_FOREACH_SAFE(cp1, &gp->consumer, consumer, tmp) {
211 		error = g_access(cp1, dr, dw, de);
212 		if (error != 0)
213 			goto fail;
214 		if (cp1->acr == 0 && cp1->acw == 0 && cp1->ace == 0 &&
215 		    cp1->flags & G_CF_ORPHAN) {
216 			g_detach(cp1);
217 			g_destroy_consumer(cp1);
218 		}
219 	}
220 
221 	/* If there are no valid disks anymore, remove device. */
222 	if (LIST_EMPTY(&gp->consumer))
223 		g_shsec_destroy(sc, 1);
224 
225 	return (error);
226 
227 fail:
228 	/* If we fail here, backout all previous changes. */
229 	LIST_FOREACH(cp2, &gp->consumer, consumer) {
230 		if (cp1 == cp2)
231 			break;
232 		g_access(cp2, -dr, -dw, -de);
233 	}
234 	return (error);
235 }
236 
237 static void
238 g_shsec_xor1(uint32_t *src, uint32_t *dst, ssize_t len)
239 {
240 
241 	for (; len > 0; len -= sizeof(uint32_t), dst++)
242 		*dst = *dst ^ *src++;
243 	KASSERT(len == 0, ("len != 0 (len=%zd)", len));
244 }
245 
246 static void
247 g_shsec_done(struct bio *bp)
248 {
249 	struct bio *pbp;
250 
251 	pbp = bp->bio_parent;
252 	if (bp->bio_error == 0)
253 		G_SHSEC_LOGREQ(2, bp, "Request done.");
254 	else {
255 		G_SHSEC_LOGREQ(0, bp, "Request failed (error=%d).",
256 		    bp->bio_error);
257 		if (pbp->bio_error == 0)
258 			pbp->bio_error = bp->bio_error;
259 	}
260 	if (pbp->bio_cmd == BIO_READ) {
261 		if ((pbp->bio_pflags & G_SHSEC_BFLAG_FIRST) != 0) {
262 			bcopy(bp->bio_data, pbp->bio_data, pbp->bio_length);
263 			pbp->bio_pflags = 0;
264 		} else {
265 			g_shsec_xor1((uint32_t *)bp->bio_data,
266 			    (uint32_t *)pbp->bio_data,
267 			    (ssize_t)pbp->bio_length);
268 		}
269 	}
270 	if (bp->bio_data != NULL) {
271 		explicit_bzero(bp->bio_data, bp->bio_length);
272 		uma_zfree(g_shsec_zone, bp->bio_data);
273 	}
274 	g_destroy_bio(bp);
275 	pbp->bio_inbed++;
276 	if (pbp->bio_children == pbp->bio_inbed) {
277 		pbp->bio_completed = pbp->bio_length;
278 		g_io_deliver(pbp, pbp->bio_error);
279 	}
280 }
281 
282 static void
283 g_shsec_xor2(uint32_t *rand, uint32_t *dst, ssize_t len)
284 {
285 
286 	for (; len > 0; len -= sizeof(uint32_t), dst++) {
287 		*rand = arc4random();
288 		*dst = *dst ^ *rand++;
289 	}
290 	KASSERT(len == 0, ("len != 0 (len=%zd)", len));
291 }
292 
293 static void
294 g_shsec_start(struct bio *bp)
295 {
296 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
297 	struct g_shsec_softc *sc;
298 	struct bio *cbp;
299 	uint32_t *dst;
300 	ssize_t len;
301 	u_int no;
302 	int error;
303 
304 	sc = bp->bio_to->geom->softc;
305 	/*
306 	 * If sc == NULL, provider's error should be set and g_shsec_start()
307 	 * should not be called at all.
308 	 */
309 	KASSERT(sc != NULL,
310 	    ("Provider's error should be set (error=%d)(device=%s).",
311 	    bp->bio_to->error, bp->bio_to->name));
312 
313 	G_SHSEC_LOGREQ(2, bp, "Request received.");
314 
315 	switch (bp->bio_cmd) {
316 	case BIO_READ:
317 	case BIO_WRITE:
318 	case BIO_FLUSH:
319 	case BIO_SPEEDUP:
320 		/*
321 		 * Only those requests are supported.
322 		 */
323 		break;
324 	case BIO_DELETE:
325 	case BIO_GETATTR:
326 		/* To which provider it should be delivered? */
327 	default:
328 		g_io_deliver(bp, EOPNOTSUPP);
329 		return;
330 	}
331 
332 	/*
333 	 * Allocate all bios first and calculate XOR.
334 	 */
335 	dst = NULL;
336 	len = bp->bio_length;
337 	if (bp->bio_cmd == BIO_READ)
338 		bp->bio_pflags = G_SHSEC_BFLAG_FIRST;
339 	for (no = 0; no < sc->sc_ndisks; no++) {
340 		cbp = g_clone_bio(bp);
341 		if (cbp == NULL) {
342 			error = ENOMEM;
343 			goto failure;
344 		}
345 		TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
346 
347 		/*
348 		 * Fill in the component buf structure.
349 		 */
350 		cbp->bio_done = g_shsec_done;
351 		cbp->bio_caller2 = sc->sc_disks[no];
352 		if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) {
353 			cbp->bio_data = uma_zalloc(g_shsec_zone, M_NOWAIT);
354 			if (cbp->bio_data == NULL) {
355 				g_shsec_alloc_failed++;
356 				error = ENOMEM;
357 				goto failure;
358 			}
359 			if (bp->bio_cmd == BIO_WRITE) {
360 				if (no == 0) {
361 					dst = (uint32_t *)cbp->bio_data;
362 					bcopy(bp->bio_data, dst, len);
363 				} else {
364 					g_shsec_xor2((uint32_t *)cbp->bio_data,
365 					    dst, len);
366 				}
367 			}
368 		}
369 	}
370 	/*
371 	 * Fire off all allocated requests!
372 	 */
373 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
374 		struct g_consumer *cp;
375 
376 		TAILQ_REMOVE(&queue, cbp, bio_queue);
377 		cp = cbp->bio_caller2;
378 		cbp->bio_caller2 = NULL;
379 		cbp->bio_to = cp->provider;
380 		G_SHSEC_LOGREQ(2, cbp, "Sending request.");
381 		g_io_request(cbp, cp);
382 	}
383 	return;
384 failure:
385 	while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
386 		TAILQ_REMOVE(&queue, cbp, bio_queue);
387 		bp->bio_children--;
388 		if (cbp->bio_data != NULL) {
389 			explicit_bzero(cbp->bio_data, cbp->bio_length);
390 			uma_zfree(g_shsec_zone, cbp->bio_data);
391 		}
392 		g_destroy_bio(cbp);
393 	}
394 	if (bp->bio_error == 0)
395 		bp->bio_error = error;
396 	g_io_deliver(bp, bp->bio_error);
397 }
398 
399 static void
400 g_shsec_check_and_run(struct g_shsec_softc *sc)
401 {
402 	off_t mediasize, ms;
403 	u_int no, sectorsize = 0;
404 
405 	if (g_shsec_nvalid(sc) != sc->sc_ndisks)
406 		return;
407 
408 	sc->sc_provider = g_new_providerf(sc->sc_geom, "shsec/%s", sc->sc_name);
409 	/*
410 	 * Find the smallest disk.
411 	 */
412 	mediasize = sc->sc_disks[0]->provider->mediasize;
413 	mediasize -= sc->sc_disks[0]->provider->sectorsize;
414 	sectorsize = sc->sc_disks[0]->provider->sectorsize;
415 	for (no = 1; no < sc->sc_ndisks; no++) {
416 		ms = sc->sc_disks[no]->provider->mediasize;
417 		ms -= sc->sc_disks[no]->provider->sectorsize;
418 		if (ms < mediasize)
419 			mediasize = ms;
420 		sectorsize = lcm(sectorsize,
421 		    sc->sc_disks[no]->provider->sectorsize);
422 	}
423 	sc->sc_provider->sectorsize = sectorsize;
424 	sc->sc_provider->mediasize = mediasize;
425 	g_error_provider(sc->sc_provider, 0);
426 
427 	G_SHSEC_DEBUG(0, "Device %s activated.", sc->sc_name);
428 }
429 
430 static int
431 g_shsec_read_metadata(struct g_consumer *cp, struct g_shsec_metadata *md)
432 {
433 	struct g_provider *pp;
434 	u_char *buf;
435 	int error;
436 
437 	g_topology_assert();
438 
439 	error = g_access(cp, 1, 0, 0);
440 	if (error != 0)
441 		return (error);
442 	pp = cp->provider;
443 	g_topology_unlock();
444 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
445 	    &error);
446 	g_topology_lock();
447 	g_access(cp, -1, 0, 0);
448 	if (buf == NULL)
449 		return (error);
450 
451 	/* Decode metadata. */
452 	shsec_metadata_decode(buf, md);
453 	g_free(buf);
454 
455 	return (0);
456 }
457 
458 /*
459  * Add disk to given device.
460  */
461 static int
462 g_shsec_add_disk(struct g_shsec_softc *sc, struct g_provider *pp, u_int no)
463 {
464 	struct g_consumer *cp, *fcp;
465 	struct g_geom *gp;
466 	struct g_shsec_metadata md;
467 	int error;
468 
469 	/* Metadata corrupted? */
470 	if (no >= sc->sc_ndisks)
471 		return (EINVAL);
472 
473 	/* Check if disk is not already attached. */
474 	if (sc->sc_disks[no] != NULL)
475 		return (EEXIST);
476 
477 	gp = sc->sc_geom;
478 	fcp = LIST_FIRST(&gp->consumer);
479 
480 	cp = g_new_consumer(gp);
481 	error = g_attach(cp, pp);
482 	if (error != 0) {
483 		g_destroy_consumer(cp);
484 		return (error);
485 	}
486 
487 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0)) {
488 		error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
489 		if (error != 0) {
490 			g_detach(cp);
491 			g_destroy_consumer(cp);
492 			return (error);
493 		}
494 	}
495 
496 	/* Reread metadata. */
497 	error = g_shsec_read_metadata(cp, &md);
498 	if (error != 0)
499 		goto fail;
500 
501 	if (strcmp(md.md_magic, G_SHSEC_MAGIC) != 0 ||
502 	    strcmp(md.md_name, sc->sc_name) != 0 || md.md_id != sc->sc_id) {
503 		G_SHSEC_DEBUG(0, "Metadata on %s changed.", pp->name);
504 		goto fail;
505 	}
506 
507 	cp->private = sc;
508 	cp->index = no;
509 	sc->sc_disks[no] = cp;
510 
511 	G_SHSEC_DEBUG(0, "Disk %s attached to %s.", pp->name, sc->sc_name);
512 
513 	g_shsec_check_and_run(sc);
514 
515 	return (0);
516 fail:
517 	if (fcp != NULL && (fcp->acr > 0 || fcp->acw > 0 || fcp->ace > 0))
518 		g_access(cp, -fcp->acr, -fcp->acw, -fcp->ace);
519 	g_detach(cp);
520 	g_destroy_consumer(cp);
521 	return (error);
522 }
523 
524 static struct g_geom *
525 g_shsec_create(struct g_class *mp, const struct g_shsec_metadata *md)
526 {
527 	struct g_shsec_softc *sc;
528 	struct g_geom *gp;
529 	u_int no;
530 
531 	G_SHSEC_DEBUG(1, "Creating device %s (id=%u).", md->md_name, md->md_id);
532 
533 	/* Two disks is minimum. */
534 	if (md->md_all < 2) {
535 		G_SHSEC_DEBUG(0, "Too few disks defined for %s.", md->md_name);
536 		return (NULL);
537 	}
538 
539 	/* Check for duplicate unit */
540 	LIST_FOREACH(gp, &mp->geom, geom) {
541 		sc = gp->softc;
542 		if (sc != NULL && strcmp(sc->sc_name, md->md_name) == 0) {
543 			G_SHSEC_DEBUG(0, "Device %s already configured.",
544 			    sc->sc_name);
545 			return (NULL);
546 		}
547 	}
548 	gp = g_new_geomf(mp, "%s", md->md_name);
549 	sc = malloc(sizeof(*sc), M_SHSEC, M_WAITOK | M_ZERO);
550 	gp->start = g_shsec_start;
551 	gp->spoiled = g_shsec_orphan;
552 	gp->orphan = g_shsec_orphan;
553 	gp->access = g_shsec_access;
554 	gp->dumpconf = g_shsec_dumpconf;
555 
556 	sc->sc_id = md->md_id;
557 	sc->sc_ndisks = md->md_all;
558 	sc->sc_disks = malloc(sizeof(struct g_consumer *) * sc->sc_ndisks,
559 	    M_SHSEC, M_WAITOK | M_ZERO);
560 	for (no = 0; no < sc->sc_ndisks; no++)
561 		sc->sc_disks[no] = NULL;
562 
563 	gp->softc = sc;
564 	sc->sc_geom = gp;
565 	sc->sc_provider = NULL;
566 
567 	G_SHSEC_DEBUG(0, "Device %s created (id=%u).", sc->sc_name, sc->sc_id);
568 
569 	return (gp);
570 }
571 
572 static int
573 g_shsec_destroy(struct g_shsec_softc *sc, boolean_t force)
574 {
575 	struct g_provider *pp;
576 	struct g_geom *gp;
577 	u_int no;
578 
579 	g_topology_assert();
580 
581 	if (sc == NULL)
582 		return (ENXIO);
583 
584 	pp = sc->sc_provider;
585 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
586 		if (force) {
587 			G_SHSEC_DEBUG(0, "Device %s is still open, so it "
588 			    "can't be definitely removed.", pp->name);
589 		} else {
590 			G_SHSEC_DEBUG(1,
591 			    "Device %s is still open (r%dw%de%d).", pp->name,
592 			    pp->acr, pp->acw, pp->ace);
593 			return (EBUSY);
594 		}
595 	}
596 
597 	for (no = 0; no < sc->sc_ndisks; no++) {
598 		if (sc->sc_disks[no] != NULL)
599 			g_shsec_remove_disk(sc->sc_disks[no]);
600 	}
601 
602 	gp = sc->sc_geom;
603 	gp->softc = NULL;
604 	KASSERT(sc->sc_provider == NULL, ("Provider still exists? (device=%s)",
605 	    gp->name));
606 	free(sc->sc_disks, M_SHSEC);
607 	free(sc, M_SHSEC);
608 
609 	pp = LIST_FIRST(&gp->provider);
610 	if (pp == NULL || (pp->acr == 0 && pp->acw == 0 && pp->ace == 0))
611 		G_SHSEC_DEBUG(0, "Device %s destroyed.", gp->name);
612 
613 	g_wither_geom(gp, ENXIO);
614 
615 	return (0);
616 }
617 
618 static int
619 g_shsec_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
620     struct g_geom *gp)
621 {
622 	struct g_shsec_softc *sc;
623 
624 	sc = gp->softc;
625 	return (g_shsec_destroy(sc, 0));
626 }
627 
628 static struct g_geom *
629 g_shsec_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
630 {
631 	struct g_shsec_metadata md;
632 	struct g_shsec_softc *sc;
633 	struct g_consumer *cp;
634 	struct g_geom *gp;
635 	int error;
636 
637 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
638 	g_topology_assert();
639 
640 	/* Skip providers that are already open for writing. */
641 	if (pp->acw > 0)
642 		return (NULL);
643 
644 	G_SHSEC_DEBUG(3, "Tasting %s.", pp->name);
645 
646 	gp = g_new_geomf(mp, "shsec:taste");
647 	gp->start = g_shsec_start;
648 	gp->access = g_shsec_access;
649 	gp->orphan = g_shsec_orphan;
650 	cp = g_new_consumer(gp);
651 	cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
652 	error = g_attach(cp, pp);
653 	if (error == 0) {
654 		error = g_shsec_read_metadata(cp, &md);
655 		g_detach(cp);
656 	}
657 	g_destroy_consumer(cp);
658 	g_destroy_geom(gp);
659 	if (error != 0)
660 		return (NULL);
661 	gp = NULL;
662 
663 	if (strcmp(md.md_magic, G_SHSEC_MAGIC) != 0)
664 		return (NULL);
665 	if (md.md_version > G_SHSEC_VERSION) {
666 		G_SHSEC_DEBUG(0, "Kernel module is too old to handle %s.\n",
667 		    pp->name);
668 		return (NULL);
669 	}
670 	/*
671 	 * Backward compatibility:
672 	 */
673 	/* There was no md_provsize field in earlier versions of metadata. */
674 	if (md.md_version < 1)
675 		md.md_provsize = pp->mediasize;
676 
677 	if (md.md_provider[0] != '\0' &&
678 	    !g_compare_names(md.md_provider, pp->name))
679 		return (NULL);
680 	if (md.md_provsize != pp->mediasize)
681 		return (NULL);
682 
683 	/*
684 	 * Let's check if device already exists.
685 	 */
686 	sc = NULL;
687 	LIST_FOREACH(gp, &mp->geom, geom) {
688 		sc = gp->softc;
689 		if (sc == NULL)
690 			continue;
691 		if (strcmp(md.md_name, sc->sc_name) != 0)
692 			continue;
693 		if (md.md_id != sc->sc_id)
694 			continue;
695 		break;
696 	}
697 	if (gp != NULL) {
698 		G_SHSEC_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
699 		error = g_shsec_add_disk(sc, pp, md.md_no);
700 		if (error != 0) {
701 			G_SHSEC_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
702 			    pp->name, gp->name, error);
703 			return (NULL);
704 		}
705 	} else {
706 		gp = g_shsec_create(mp, &md);
707 		if (gp == NULL) {
708 			G_SHSEC_DEBUG(0, "Cannot create device %s.", md.md_name);
709 			return (NULL);
710 		}
711 		sc = gp->softc;
712 		G_SHSEC_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
713 		error = g_shsec_add_disk(sc, pp, md.md_no);
714 		if (error != 0) {
715 			G_SHSEC_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
716 			    pp->name, gp->name, error);
717 			g_shsec_destroy(sc, 1);
718 			return (NULL);
719 		}
720 	}
721 	return (gp);
722 }
723 
724 static struct g_shsec_softc *
725 g_shsec_find_device(struct g_class *mp, const char *name)
726 {
727 	struct g_shsec_softc *sc;
728 	struct g_geom *gp;
729 
730 	LIST_FOREACH(gp, &mp->geom, geom) {
731 		sc = gp->softc;
732 		if (sc == NULL)
733 			continue;
734 		if (strcmp(sc->sc_name, name) == 0)
735 			return (sc);
736 	}
737 	return (NULL);
738 }
739 
740 static void
741 g_shsec_ctl_destroy(struct gctl_req *req, struct g_class *mp)
742 {
743 	struct g_shsec_softc *sc;
744 	int *force, *nargs, error;
745 	const char *name;
746 	char param[16];
747 	u_int i;
748 
749 	g_topology_assert();
750 
751 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
752 	if (nargs == NULL) {
753 		gctl_error(req, "No '%s' argument.", "nargs");
754 		return;
755 	}
756 	if (*nargs <= 0) {
757 		gctl_error(req, "Missing device(s).");
758 		return;
759 	}
760 	force = gctl_get_paraml(req, "force", sizeof(*force));
761 	if (force == NULL) {
762 		gctl_error(req, "No '%s' argument.", "force");
763 		return;
764 	}
765 
766 	for (i = 0; i < (u_int)*nargs; i++) {
767 		snprintf(param, sizeof(param), "arg%u", i);
768 		name = gctl_get_asciiparam(req, param);
769 		if (name == NULL) {
770 			gctl_error(req, "No 'arg%u' argument.", i);
771 			return;
772 		}
773 		sc = g_shsec_find_device(mp, name);
774 		if (sc == NULL) {
775 			gctl_error(req, "No such device: %s.", name);
776 			return;
777 		}
778 		error = g_shsec_destroy(sc, *force);
779 		if (error != 0) {
780 			gctl_error(req, "Cannot destroy device %s (error=%d).",
781 			    sc->sc_name, error);
782 			return;
783 		}
784 	}
785 }
786 
787 static void
788 g_shsec_config(struct gctl_req *req, struct g_class *mp, const char *verb)
789 {
790 	uint32_t *version;
791 
792 	g_topology_assert();
793 
794 	version = gctl_get_paraml(req, "version", sizeof(*version));
795 	if (version == NULL) {
796 		gctl_error(req, "No '%s' argument.", "version");
797 		return;
798 	}
799 	if (*version != G_SHSEC_VERSION) {
800 		gctl_error(req, "Userland and kernel parts are out of sync.");
801 		return;
802 	}
803 
804 	if (strcmp(verb, "stop") == 0) {
805 		g_shsec_ctl_destroy(req, mp);
806 		return;
807 	}
808 
809 	gctl_error(req, "Unknown verb.");
810 }
811 
812 static void
813 g_shsec_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
814     struct g_consumer *cp, struct g_provider *pp)
815 {
816 	struct g_shsec_softc *sc;
817 
818 	sc = gp->softc;
819 	if (sc == NULL)
820 		return;
821 	if (pp != NULL) {
822 		/* Nothing here. */
823 	} else if (cp != NULL) {
824 		sbuf_printf(sb, "%s<Number>%u</Number>\n", indent,
825 		    (u_int)cp->index);
826 	} else {
827 		sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
828 		sbuf_printf(sb, "%s<Status>Total=%u, Online=%u</Status>\n",
829 		    indent, sc->sc_ndisks, g_shsec_nvalid(sc));
830 		sbuf_printf(sb, "%s<State>", indent);
831 		if (sc->sc_provider != NULL && sc->sc_provider->error == 0)
832 			sbuf_printf(sb, "UP");
833 		else
834 			sbuf_printf(sb, "DOWN");
835 		sbuf_printf(sb, "</State>\n");
836 	}
837 }
838 
839 DECLARE_GEOM_CLASS(g_shsec_class, g_shsec);
840 MODULE_VERSION(geom_shsec, 0);
841