xref: /netbsd-src/sys/dev/cgd.c (revision f21b7d7f2cbdd5c14b3882c4e8a3d43580d460a6)
1 /* $NetBSD: cgd.c,v 1.111 2016/09/14 23:16:30 mlelstv Exp $ */
2 
3 /*-
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Roland C. Dowdeswell.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: cgd.c,v 1.111 2016/09/14 23:16:30 mlelstv Exp $");
34 
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/proc.h>
39 #include <sys/errno.h>
40 #include <sys/buf.h>
41 #include <sys/bufq.h>
42 #include <sys/malloc.h>
43 #include <sys/module.h>
44 #include <sys/pool.h>
45 #include <sys/ioctl.h>
46 #include <sys/device.h>
47 #include <sys/disk.h>
48 #include <sys/disklabel.h>
49 #include <sys/fcntl.h>
50 #include <sys/namei.h> /* for pathbuf */
51 #include <sys/vnode.h>
52 #include <sys/conf.h>
53 #include <sys/syslog.h>
54 
55 #include <dev/dkvar.h>
56 #include <dev/cgdvar.h>
57 
58 #include <miscfs/specfs/specdev.h> /* for v_rdev */
59 
60 #include "ioconf.h"
61 
62 /* Entry Point Functions */
63 
64 static dev_type_open(cgdopen);
65 static dev_type_close(cgdclose);
66 static dev_type_read(cgdread);
67 static dev_type_write(cgdwrite);
68 static dev_type_ioctl(cgdioctl);
69 static dev_type_strategy(cgdstrategy);
70 static dev_type_dump(cgddump);
71 static dev_type_size(cgdsize);
72 
73 const struct bdevsw cgd_bdevsw = {
74 	.d_open = cgdopen,
75 	.d_close = cgdclose,
76 	.d_strategy = cgdstrategy,
77 	.d_ioctl = cgdioctl,
78 	.d_dump = cgddump,
79 	.d_psize = cgdsize,
80 	.d_discard = nodiscard,
81 	.d_flag = D_DISK
82 };
83 
84 const struct cdevsw cgd_cdevsw = {
85 	.d_open = cgdopen,
86 	.d_close = cgdclose,
87 	.d_read = cgdread,
88 	.d_write = cgdwrite,
89 	.d_ioctl = cgdioctl,
90 	.d_stop = nostop,
91 	.d_tty = notty,
92 	.d_poll = nopoll,
93 	.d_mmap = nommap,
94 	.d_kqfilter = nokqfilter,
95 	.d_discard = nodiscard,
96 	.d_flag = D_DISK
97 };
98 
99 static int cgd_match(device_t, cfdata_t, void *);
100 static void cgd_attach(device_t, device_t, void *);
101 static int cgd_detach(device_t, int);
102 static struct cgd_softc	*cgd_spawn(int);
103 static int cgd_destroy(device_t);
104 
105 /* Internal Functions */
106 
107 static int	cgd_diskstart(device_t, struct buf *);
108 static void	cgdiodone(struct buf *);
109 static int	cgd_dumpblocks(device_t, void *, daddr_t, int);
110 
111 static int	cgd_ioctl_set(struct cgd_softc *, void *, struct lwp *);
112 static int	cgd_ioctl_clr(struct cgd_softc *, struct lwp *);
113 static int	cgd_ioctl_get(dev_t, void *, struct lwp *);
114 static int	cgdinit(struct cgd_softc *, const char *, struct vnode *,
115 			struct lwp *);
116 static void	cgd_cipher(struct cgd_softc *, void *, void *,
117 			   size_t, daddr_t, size_t, int);
118 
119 static struct dkdriver cgddkdriver = {
120         .d_minphys  = minphys,
121         .d_open = cgdopen,
122         .d_close = cgdclose,
123         .d_strategy = cgdstrategy,
124         .d_iosize = NULL,
125         .d_diskstart = cgd_diskstart,
126         .d_dumpblocks = cgd_dumpblocks,
127         .d_lastclose = NULL
128 };
129 
130 CFATTACH_DECL3_NEW(cgd, sizeof(struct cgd_softc),
131     cgd_match, cgd_attach, cgd_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN);
132 extern struct cfdriver cgd_cd;
133 
134 /* DIAGNOSTIC and DEBUG definitions */
135 
136 #if defined(CGDDEBUG) && !defined(DEBUG)
137 #define DEBUG
138 #endif
139 
140 #ifdef DEBUG
141 int cgddebug = 0;
142 
143 #define CGDB_FOLLOW	0x1
144 #define CGDB_IO	0x2
145 #define CGDB_CRYPTO	0x4
146 
147 #define IFDEBUG(x,y)		if (cgddebug & (x)) y
148 #define DPRINTF(x,y)		IFDEBUG(x, printf y)
149 #define DPRINTF_FOLLOW(y)	DPRINTF(CGDB_FOLLOW, y)
150 
151 static void	hexprint(const char *, void *, int);
152 
153 #else
154 #define IFDEBUG(x,y)
155 #define DPRINTF(x,y)
156 #define DPRINTF_FOLLOW(y)
157 #endif
158 
159 #ifdef DIAGNOSTIC
160 #define DIAGPANIC(x)		panic x
161 #define DIAGCONDPANIC(x,y)	if (x) panic y
162 #else
163 #define DIAGPANIC(x)
164 #define DIAGCONDPANIC(x,y)
165 #endif
166 
167 /* Global variables */
168 
169 /* Utility Functions */
170 
171 #define CGDUNIT(x)		DISKUNIT(x)
172 #define GETCGD_SOFTC(_cs, x)	if (!((_cs) = getcgd_softc(x))) return ENXIO
173 
174 /* The code */
175 
176 static struct cgd_softc *
177 getcgd_softc(dev_t dev)
178 {
179 	int	unit = CGDUNIT(dev);
180 	struct cgd_softc *sc;
181 
182 	DPRINTF_FOLLOW(("getcgd_softc(0x%"PRIx64"): unit = %d\n", dev, unit));
183 
184 	sc = device_lookup_private(&cgd_cd, unit);
185 	if (sc == NULL)
186 		sc = cgd_spawn(unit);
187 	return sc;
188 }
189 
190 static int
191 cgd_match(device_t self, cfdata_t cfdata, void *aux)
192 {
193 
194 	return 1;
195 }
196 
197 static void
198 cgd_attach(device_t parent, device_t self, void *aux)
199 {
200 	struct cgd_softc *sc = device_private(self);
201 
202 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_BIO);
203 	dk_init(&sc->sc_dksc, self, DKTYPE_CGD);
204 	disk_init(&sc->sc_dksc.sc_dkdev, sc->sc_dksc.sc_xname, &cgddkdriver);
205 
206 	if (!pmf_device_register(self, NULL, NULL))
207 		aprint_error_dev(self,
208 		    "unable to register power management hooks\n");
209 }
210 
211 
212 static int
213 cgd_detach(device_t self, int flags)
214 {
215 	int ret;
216 	const int pmask = 1 << RAW_PART;
217 	struct cgd_softc *sc = device_private(self);
218 	struct dk_softc *dksc = &sc->sc_dksc;
219 
220 	if (DK_BUSY(dksc, pmask))
221 		return EBUSY;
222 
223 	if (DK_ATTACHED(dksc) &&
224 	    (ret = cgd_ioctl_clr(sc, curlwp)) != 0)
225 		return ret;
226 
227 	disk_destroy(&dksc->sc_dkdev);
228 	mutex_destroy(&sc->sc_lock);
229 
230 	return 0;
231 }
232 
233 void
234 cgdattach(int num)
235 {
236 	int error;
237 
238 	error = config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
239 	if (error != 0)
240 		aprint_error("%s: unable to register cfattach\n",
241 		    cgd_cd.cd_name);
242 }
243 
244 static struct cgd_softc *
245 cgd_spawn(int unit)
246 {
247 	cfdata_t cf;
248 
249 	cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
250 	cf->cf_name = cgd_cd.cd_name;
251 	cf->cf_atname = cgd_cd.cd_name;
252 	cf->cf_unit = unit;
253 	cf->cf_fstate = FSTATE_STAR;
254 
255 	return device_private(config_attach_pseudo(cf));
256 }
257 
258 static int
259 cgd_destroy(device_t dev)
260 {
261 	int error;
262 	cfdata_t cf;
263 
264 	cf = device_cfdata(dev);
265 	error = config_detach(dev, DETACH_QUIET);
266 	if (error)
267 		return error;
268 	free(cf, M_DEVBUF);
269 	return 0;
270 }
271 
272 static int
273 cgdopen(dev_t dev, int flags, int fmt, struct lwp *l)
274 {
275 	struct	cgd_softc *cs;
276 
277 	DPRINTF_FOLLOW(("cgdopen(0x%"PRIx64", %d)\n", dev, flags));
278 	GETCGD_SOFTC(cs, dev);
279 	return dk_open(&cs->sc_dksc, dev, flags, fmt, l);
280 }
281 
282 static int
283 cgdclose(dev_t dev, int flags, int fmt, struct lwp *l)
284 {
285 	int error;
286 	struct	cgd_softc *cs;
287 	struct	dk_softc *dksc;
288 
289 	DPRINTF_FOLLOW(("cgdclose(0x%"PRIx64", %d)\n", dev, flags));
290 	GETCGD_SOFTC(cs, dev);
291 	dksc = &cs->sc_dksc;
292 	if ((error =  dk_close(dksc, dev, flags, fmt, l)) != 0)
293 		return error;
294 
295 	if (!DK_ATTACHED(dksc)) {
296 		if ((error = cgd_destroy(cs->sc_dksc.sc_dev)) != 0) {
297 			aprint_error_dev(dksc->sc_dev,
298 			    "unable to detach instance\n");
299 			return error;
300 		}
301 	}
302 	return 0;
303 }
304 
305 static void
306 cgdstrategy(struct buf *bp)
307 {
308 	struct	cgd_softc *cs;
309 
310 	DPRINTF_FOLLOW(("cgdstrategy(%p): b_bcount = %ld\n", bp,
311 	    (long)bp->b_bcount));
312 
313 	cs = getcgd_softc(bp->b_dev);
314 	if (!cs) {
315 		bp->b_error = ENXIO;
316 		goto bail;
317 	}
318 
319 	/*
320 	 * Reject unaligned writes.
321 	 */
322 	if (((uintptr_t)bp->b_data & 3) != 0) {
323 		bp->b_error = EINVAL;
324 		goto bail;
325 	}
326 
327 	dk_strategy(&cs->sc_dksc, bp);
328 	return;
329 
330 bail:
331 	bp->b_resid = bp->b_bcount;
332 	biodone(bp);
333 	return;
334 }
335 
336 static int
337 cgdsize(dev_t dev)
338 {
339 	struct cgd_softc *cs = getcgd_softc(dev);
340 
341 	DPRINTF_FOLLOW(("cgdsize(0x%"PRIx64")\n", dev));
342 	if (!cs)
343 		return -1;
344 	return dk_size(&cs->sc_dksc, dev);
345 }
346 
347 /*
348  * cgd_{get,put}data are functions that deal with getting a buffer
349  * for the new encrypted data.  We have a buffer per device so that
350  * we can ensure that we can always have a transaction in flight.
351  * We use this buffer first so that we have one less piece of
352  * malloc'ed data at any given point.
353  */
354 
355 static void *
356 cgd_getdata(struct dk_softc *dksc, unsigned long size)
357 {
358 	struct	cgd_softc *cs = (struct cgd_softc *)dksc;
359 	void *	data = NULL;
360 
361 	mutex_enter(&cs->sc_lock);
362 	if (cs->sc_data_used == 0) {
363 		cs->sc_data_used = 1;
364 		data = cs->sc_data;
365 	}
366 	mutex_exit(&cs->sc_lock);
367 
368 	if (data)
369 		return data;
370 
371 	return malloc(size, M_DEVBUF, M_NOWAIT);
372 }
373 
374 static void
375 cgd_putdata(struct dk_softc *dksc, void *data)
376 {
377 	struct	cgd_softc *cs = (struct cgd_softc *)dksc;
378 
379 	if (data == cs->sc_data) {
380 		mutex_enter(&cs->sc_lock);
381 		cs->sc_data_used = 0;
382 		mutex_exit(&cs->sc_lock);
383 	} else {
384 		free(data, M_DEVBUF);
385 	}
386 }
387 
388 static int
389 cgd_diskstart(device_t dev, struct buf *bp)
390 {
391 	struct	cgd_softc *cs = device_private(dev);
392 	struct	dk_softc *dksc = &cs->sc_dksc;
393 	struct	disk_geom *dg = &dksc->sc_dkdev.dk_geom;
394 	struct	buf *nbp;
395 	void *	addr;
396 	void *	newaddr;
397 	daddr_t	bn;
398 	struct	vnode *vp;
399 
400 	DPRINTF_FOLLOW(("cgd_diskstart(%p, %p)\n", dksc, bp));
401 
402 	bn = bp->b_rawblkno;
403 
404 	/*
405 	 * We attempt to allocate all of our resources up front, so that
406 	 * we can fail quickly if they are unavailable.
407 	 */
408 	nbp = getiobuf(cs->sc_tvn, false);
409 	if (nbp == NULL)
410 		return EAGAIN;
411 
412 	/*
413 	 * If we are writing, then we need to encrypt the outgoing
414 	 * block into a new block of memory.
415 	 */
416 	newaddr = addr = bp->b_data;
417 	if ((bp->b_flags & B_READ) == 0) {
418 		newaddr = cgd_getdata(dksc, bp->b_bcount);
419 		if (!newaddr) {
420 			putiobuf(nbp);
421 			return EAGAIN;
422 		}
423 		cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn,
424 		    dg->dg_secsize, CGD_CIPHER_ENCRYPT);
425 	}
426 
427 	nbp->b_data = newaddr;
428 	nbp->b_flags = bp->b_flags;
429 	nbp->b_oflags = bp->b_oflags;
430 	nbp->b_cflags = bp->b_cflags;
431 	nbp->b_iodone = cgdiodone;
432 	nbp->b_proc = bp->b_proc;
433 	nbp->b_blkno = btodb(bn * dg->dg_secsize);
434 	nbp->b_bcount = bp->b_bcount;
435 	nbp->b_private = bp;
436 
437 	BIO_COPYPRIO(nbp, bp);
438 
439 	if ((nbp->b_flags & B_READ) == 0) {
440 		vp = nbp->b_vp;
441 		mutex_enter(vp->v_interlock);
442 		vp->v_numoutput++;
443 		mutex_exit(vp->v_interlock);
444 	}
445 	VOP_STRATEGY(cs->sc_tvn, nbp);
446 
447 	return 0;
448 }
449 
450 static void
451 cgdiodone(struct buf *nbp)
452 {
453 	struct	buf *obp = nbp->b_private;
454 	struct	cgd_softc *cs = getcgd_softc(obp->b_dev);
455 	struct	dk_softc *dksc = &cs->sc_dksc;
456 	struct	disk_geom *dg = &dksc->sc_dkdev.dk_geom;
457 	daddr_t	bn;
458 
459 	KDASSERT(cs);
460 
461 	DPRINTF_FOLLOW(("cgdiodone(%p)\n", nbp));
462 	DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %d resid %d\n",
463 	    obp, obp->b_bcount, obp->b_resid));
464 	DPRINTF(CGDB_IO, (" dev 0x%"PRIx64", nbp %p bn %" PRId64
465 	    " addr %p bcnt %d\n", nbp->b_dev, nbp, nbp->b_blkno, nbp->b_data,
466 		nbp->b_bcount));
467 	if (nbp->b_error != 0) {
468 		obp->b_error = nbp->b_error;
469 		DPRINTF(CGDB_IO, ("%s: error %d\n", dksc->sc_xname,
470 		    obp->b_error));
471 	}
472 
473 	/* Perform the decryption if we are reading.
474 	 *
475 	 * Note: use the blocknumber from nbp, since it is what
476 	 *       we used to encrypt the blocks.
477 	 */
478 
479 	if (nbp->b_flags & B_READ) {
480 		bn = dbtob(nbp->b_blkno) / dg->dg_secsize;
481 		cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount,
482 		    bn, dg->dg_secsize, CGD_CIPHER_DECRYPT);
483 	}
484 
485 	/* If we allocated memory, free it now... */
486 	if (nbp->b_data != obp->b_data)
487 		cgd_putdata(dksc, nbp->b_data);
488 
489 	putiobuf(nbp);
490 
491 	/* Request is complete for whatever reason */
492 	obp->b_resid = 0;
493 	if (obp->b_error != 0)
494 		obp->b_resid = obp->b_bcount;
495 
496 	dk_done(dksc, obp);
497 	dk_start(dksc, NULL);
498 }
499 
500 static int
501 cgd_dumpblocks(device_t dev, void *va, daddr_t blkno, int nblk)
502 {
503 	struct cgd_softc *sc = device_private(dev);
504 	struct dk_softc *dksc = &sc->sc_dksc;
505 	struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;
506 	size_t nbytes, blksize;
507 	void *buf;
508 	int error;
509 
510 	/*
511 	 * dk_dump gives us units of disklabel sectors.  Everything
512 	 * else in cgd uses units of diskgeom sectors.  These had
513 	 * better agree; otherwise we need to figure out how to convert
514 	 * between them.
515 	 */
516 	KASSERTMSG((dg->dg_secsize == dksc->sc_dkdev.dk_label->d_secsize),
517 	    "diskgeom secsize %"PRIu32" != disklabel secsize %"PRIu32,
518 	    dg->dg_secsize, dksc->sc_dkdev.dk_label->d_secsize);
519 	blksize = dg->dg_secsize;
520 
521 	/*
522 	 * Compute the number of bytes in this request, which dk_dump
523 	 * has `helpfully' converted to a number of blocks for us.
524 	 */
525 	nbytes = nblk*blksize;
526 
527 	/* Try to acquire a buffer to store the ciphertext.  */
528 	buf = cgd_getdata(dksc, nbytes);
529 	if (buf == NULL)
530 		/* Out of memory: give up.  */
531 		return ENOMEM;
532 
533 	/* Encrypt the caller's data into the temporary buffer.  */
534 	cgd_cipher(sc, buf, va, nbytes, blkno, blksize, CGD_CIPHER_ENCRYPT);
535 
536 	/* Pass it on to the underlying disk device.  */
537 	error = bdev_dump(sc->sc_tdev, blkno, buf, nbytes);
538 
539 	/* Release the buffer.  */
540 	cgd_putdata(dksc, buf);
541 
542 	/* Return any error from the underlying disk device.  */
543 	return error;
544 }
545 
546 /* XXX: we should probably put these into dksubr.c, mostly */
547 static int
548 cgdread(dev_t dev, struct uio *uio, int flags)
549 {
550 	struct	cgd_softc *cs;
551 	struct	dk_softc *dksc;
552 
553 	DPRINTF_FOLLOW(("cgdread(0x%llx, %p, %d)\n",
554 	    (unsigned long long)dev, uio, flags));
555 	GETCGD_SOFTC(cs, dev);
556 	dksc = &cs->sc_dksc;
557 	if (!DK_ATTACHED(dksc))
558 		return ENXIO;
559 	return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio);
560 }
561 
562 /* XXX: we should probably put these into dksubr.c, mostly */
563 static int
564 cgdwrite(dev_t dev, struct uio *uio, int flags)
565 {
566 	struct	cgd_softc *cs;
567 	struct	dk_softc *dksc;
568 
569 	DPRINTF_FOLLOW(("cgdwrite(0x%"PRIx64", %p, %d)\n", dev, uio, flags));
570 	GETCGD_SOFTC(cs, dev);
571 	dksc = &cs->sc_dksc;
572 	if (!DK_ATTACHED(dksc))
573 		return ENXIO;
574 	return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio);
575 }
576 
577 static int
578 cgdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
579 {
580 	struct	cgd_softc *cs;
581 	struct	dk_softc *dksc;
582 	int	part = DISKPART(dev);
583 	int	pmask = 1 << part;
584 
585 	DPRINTF_FOLLOW(("cgdioctl(0x%"PRIx64", %ld, %p, %d, %p)\n",
586 	    dev, cmd, data, flag, l));
587 
588 	switch (cmd) {
589 	case CGDIOCGET:
590 		return cgd_ioctl_get(dev, data, l);
591 	case CGDIOCSET:
592 	case CGDIOCCLR:
593 		if ((flag & FWRITE) == 0)
594 			return EBADF;
595 		/* FALLTHROUGH */
596 	default:
597 		GETCGD_SOFTC(cs, dev);
598 		dksc = &cs->sc_dksc;
599 		break;
600 	}
601 
602 	switch (cmd) {
603 	case CGDIOCSET:
604 		if (DK_ATTACHED(dksc))
605 			return EBUSY;
606 		return cgd_ioctl_set(cs, data, l);
607 	case CGDIOCCLR:
608 		if (DK_BUSY(&cs->sc_dksc, pmask))
609 			return EBUSY;
610 		return cgd_ioctl_clr(cs, l);
611 	case DIOCCACHESYNC:
612 		/*
613 		 * XXX Do we really need to care about having a writable
614 		 * file descriptor here?
615 		 */
616 		if ((flag & FWRITE) == 0)
617 			return (EBADF);
618 
619 		/*
620 		 * We pass this call down to the underlying disk.
621 		 */
622 		return VOP_IOCTL(cs->sc_tvn, cmd, data, flag, l->l_cred);
623 	case DIOCGSTRATEGY:
624 	case DIOCSSTRATEGY:
625 		if (!DK_ATTACHED(dksc))
626 			return ENOENT;
627 		/*FALLTHROUGH*/
628 	default:
629 		return dk_ioctl(dksc, dev, cmd, data, flag, l);
630 	case CGDIOCGET:
631 		KASSERT(0);
632 		return EINVAL;
633 	}
634 }
635 
636 static int
637 cgddump(dev_t dev, daddr_t blkno, void *va, size_t size)
638 {
639 	struct	cgd_softc *cs;
640 
641 	DPRINTF_FOLLOW(("cgddump(0x%"PRIx64", %" PRId64 ", %p, %lu)\n",
642 	    dev, blkno, va, (unsigned long)size));
643 	GETCGD_SOFTC(cs, dev);
644 	return dk_dump(&cs->sc_dksc, dev, blkno, va, size);
645 }
646 
647 /*
648  * XXXrcd:
649  *  for now we hardcode the maximum key length.
650  */
651 #define MAX_KEYSIZE	1024
652 
653 static const struct {
654 	const char *n;
655 	int v;
656 	int d;
657 } encblkno[] = {
658 	{ "encblkno",  CGD_CIPHER_CBC_ENCBLKNO8, 1 },
659 	{ "encblkno8", CGD_CIPHER_CBC_ENCBLKNO8, 1 },
660 	{ "encblkno1", CGD_CIPHER_CBC_ENCBLKNO1, 8 },
661 };
662 
663 /* ARGSUSED */
664 static int
665 cgd_ioctl_set(struct cgd_softc *cs, void *data, struct lwp *l)
666 {
667 	struct	 cgd_ioctl *ci = data;
668 	struct	 vnode *vp;
669 	int	 ret;
670 	size_t	 i;
671 	size_t	 keybytes;			/* key length in bytes */
672 	const char *cp;
673 	struct pathbuf *pb;
674 	char	 *inbuf;
675 	struct dk_softc *dksc = &cs->sc_dksc;
676 
677 	cp = ci->ci_disk;
678 
679 	ret = pathbuf_copyin(ci->ci_disk, &pb);
680 	if (ret != 0) {
681 		return ret;
682 	}
683 	ret = dk_lookup(pb, l, &vp);
684 	pathbuf_destroy(pb);
685 	if (ret != 0) {
686 		return ret;
687 	}
688 
689 	inbuf = malloc(MAX_KEYSIZE, M_TEMP, M_WAITOK);
690 
691 	if ((ret = cgdinit(cs, cp, vp, l)) != 0)
692 		goto bail;
693 
694 	(void)memset(inbuf, 0, MAX_KEYSIZE);
695 	ret = copyinstr(ci->ci_alg, inbuf, 256, NULL);
696 	if (ret)
697 		goto bail;
698 	cs->sc_cfuncs = cryptfuncs_find(inbuf);
699 	if (!cs->sc_cfuncs) {
700 		ret = EINVAL;
701 		goto bail;
702 	}
703 
704 	(void)memset(inbuf, 0, MAX_KEYSIZE);
705 	ret = copyinstr(ci->ci_ivmethod, inbuf, MAX_KEYSIZE, NULL);
706 	if (ret)
707 		goto bail;
708 
709 	for (i = 0; i < __arraycount(encblkno); i++)
710 		if (strcmp(encblkno[i].n, inbuf) == 0)
711 			break;
712 
713 	if (i == __arraycount(encblkno)) {
714 		ret = EINVAL;
715 		goto bail;
716 	}
717 
718 	keybytes = ci->ci_keylen / 8 + 1;
719 	if (keybytes > MAX_KEYSIZE) {
720 		ret = EINVAL;
721 		goto bail;
722 	}
723 
724 	(void)memset(inbuf, 0, MAX_KEYSIZE);
725 	ret = copyin(ci->ci_key, inbuf, keybytes);
726 	if (ret)
727 		goto bail;
728 
729 	cs->sc_cdata.cf_blocksize = ci->ci_blocksize;
730 	cs->sc_cdata.cf_mode = encblkno[i].v;
731 	cs->sc_cdata.cf_keylen = ci->ci_keylen;
732 	cs->sc_cdata.cf_priv = cs->sc_cfuncs->cf_init(ci->ci_keylen, inbuf,
733 	    &cs->sc_cdata.cf_blocksize);
734 	if (cs->sc_cdata.cf_blocksize > CGD_MAXBLOCKSIZE) {
735 	    log(LOG_WARNING, "cgd: Disallowed cipher with blocksize %zu > %u\n",
736 		cs->sc_cdata.cf_blocksize, CGD_MAXBLOCKSIZE);
737 	    cs->sc_cdata.cf_priv = NULL;
738 	}
739 
740 	/*
741 	 * The blocksize is supposed to be in bytes. Unfortunately originally
742 	 * it was expressed in bits. For compatibility we maintain encblkno
743 	 * and encblkno8.
744 	 */
745 	cs->sc_cdata.cf_blocksize /= encblkno[i].d;
746 	(void)explicit_memset(inbuf, 0, MAX_KEYSIZE);
747 	if (!cs->sc_cdata.cf_priv) {
748 		ret = EINVAL;		/* XXX is this the right error? */
749 		goto bail;
750 	}
751 	free(inbuf, M_TEMP);
752 
753 	bufq_alloc(&dksc->sc_bufq, "fcfs", 0);
754 
755 	cs->sc_data = malloc(MAXPHYS, M_DEVBUF, M_WAITOK);
756 	cs->sc_data_used = 0;
757 
758 	/* Attach the disk. */
759 	dk_attach(dksc);
760 	disk_attach(&dksc->sc_dkdev);
761 
762 	disk_set_info(dksc->sc_dev, &dksc->sc_dkdev, NULL);
763 
764 	/* Discover wedges on this disk. */
765 	dkwedge_discover(&dksc->sc_dkdev);
766 
767 	return 0;
768 
769 bail:
770 	free(inbuf, M_TEMP);
771 	(void)vn_close(vp, FREAD|FWRITE, l->l_cred);
772 	return ret;
773 }
774 
775 /* ARGSUSED */
776 static int
777 cgd_ioctl_clr(struct cgd_softc *cs, struct lwp *l)
778 {
779 	struct	dk_softc *dksc = &cs->sc_dksc;
780 
781 	if (!DK_ATTACHED(dksc))
782 		return ENXIO;
783 
784 	/* Delete all of our wedges. */
785 	dkwedge_delall(&dksc->sc_dkdev);
786 
787 	/* Kill off any queued buffers. */
788 	dk_drain(dksc);
789 	bufq_free(dksc->sc_bufq);
790 
791 	(void)vn_close(cs->sc_tvn, FREAD|FWRITE, l->l_cred);
792 	cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv);
793 	free(cs->sc_tpath, M_DEVBUF);
794 	free(cs->sc_data, M_DEVBUF);
795 	cs->sc_data_used = 0;
796 	dk_detach(dksc);
797 	disk_detach(&dksc->sc_dkdev);
798 
799 	return 0;
800 }
801 
802 static int
803 cgd_ioctl_get(dev_t dev, void *data, struct lwp *l)
804 {
805 	struct cgd_softc *cs = getcgd_softc(dev);
806 	struct cgd_user *cgu;
807 	int unit;
808 	struct	dk_softc *dksc = &cs->sc_dksc;
809 
810 	unit = CGDUNIT(dev);
811 	cgu = (struct cgd_user *)data;
812 
813 	DPRINTF_FOLLOW(("cgd_ioctl_get(0x%"PRIx64", %d, %p, %p)\n",
814 			   dev, unit, data, l));
815 
816 	if (cgu->cgu_unit == -1)
817 		cgu->cgu_unit = unit;
818 
819 	if (cgu->cgu_unit < 0)
820 		return EINVAL;	/* XXX: should this be ENXIO? */
821 
822 	cs = device_lookup_private(&cgd_cd, unit);
823 	if (cs == NULL || !DK_ATTACHED(dksc)) {
824 		cgu->cgu_dev = 0;
825 		cgu->cgu_alg[0] = '\0';
826 		cgu->cgu_blocksize = 0;
827 		cgu->cgu_mode = 0;
828 		cgu->cgu_keylen = 0;
829 	}
830 	else {
831 		cgu->cgu_dev = cs->sc_tdev;
832 		strlcpy(cgu->cgu_alg, cs->sc_cfuncs->cf_name,
833 		    sizeof(cgu->cgu_alg));
834 		cgu->cgu_blocksize = cs->sc_cdata.cf_blocksize;
835 		cgu->cgu_mode = cs->sc_cdata.cf_mode;
836 		cgu->cgu_keylen = cs->sc_cdata.cf_keylen;
837 	}
838 	return 0;
839 }
840 
841 static int
842 cgdinit(struct cgd_softc *cs, const char *cpath, struct vnode *vp,
843 	struct lwp *l)
844 {
845 	struct	disk_geom *dg;
846 	int	ret;
847 	char	*tmppath;
848 	uint64_t psize;
849 	unsigned secsize;
850 	struct dk_softc *dksc = &cs->sc_dksc;
851 
852 	cs->sc_tvn = vp;
853 	cs->sc_tpath = NULL;
854 
855 	tmppath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
856 	ret = copyinstr(cpath, tmppath, MAXPATHLEN, &cs->sc_tpathlen);
857 	if (ret)
858 		goto bail;
859 	cs->sc_tpath = malloc(cs->sc_tpathlen, M_DEVBUF, M_WAITOK);
860 	memcpy(cs->sc_tpath, tmppath, cs->sc_tpathlen);
861 
862 	cs->sc_tdev = vp->v_rdev;
863 
864 	if ((ret = getdisksize(vp, &psize, &secsize)) != 0)
865 		goto bail;
866 
867 	if (psize == 0) {
868 		ret = ENODEV;
869 		goto bail;
870 	}
871 
872 	/*
873 	 * XXX here we should probe the underlying device.  If we
874 	 *     are accessing a partition of type RAW_PART, then
875 	 *     we should populate our initial geometry with the
876 	 *     geometry that we discover from the device.
877 	 */
878 	dg = &dksc->sc_dkdev.dk_geom;
879 	memset(dg, 0, sizeof(*dg));
880 	dg->dg_secperunit = psize;
881 	dg->dg_secsize = secsize;
882 	dg->dg_ntracks = 1;
883 	dg->dg_nsectors = 1024 * 1024 / dg->dg_secsize;
884 	dg->dg_ncylinders = dg->dg_secperunit / dg->dg_nsectors;
885 
886 bail:
887 	free(tmppath, M_TEMP);
888 	if (ret && cs->sc_tpath)
889 		free(cs->sc_tpath, M_DEVBUF);
890 	return ret;
891 }
892 
893 /*
894  * Our generic cipher entry point.  This takes care of the
895  * IV mode and passes off the work to the specific cipher.
896  * We implement here the IV method ``encrypted block
897  * number''.
898  *
899  * For the encryption case, we accomplish this by setting
900  * up a struct uio where the first iovec of the source is
901  * the blocknumber and the first iovec of the dest is a
902  * sink.  We then call the cipher with an IV of zero, and
903  * the right thing happens.
904  *
905  * For the decryption case, we use the same basic mechanism
906  * for symmetry, but we encrypt the block number in the
907  * first iovec.
908  *
909  * We mainly do this to avoid requiring the definition of
910  * an ECB mode.
911  *
912  * XXXrcd: for now we rely on our own crypto framework defined
913  *         in dev/cgd_crypto.c.  This will change when we
914  *         get a generic kernel crypto framework.
915  */
916 
917 static void
918 blkno2blkno_buf(char *sbuf, daddr_t blkno)
919 {
920 	int	i;
921 
922 	/* Set up the blkno in blkno_buf, here we do not care much
923 	 * about the final layout of the information as long as we
924 	 * can guarantee that each sector will have a different IV
925 	 * and that the endianness of the machine will not affect
926 	 * the representation that we have chosen.
927 	 *
928 	 * We choose this representation, because it does not rely
929 	 * on the size of buf (which is the blocksize of the cipher),
930 	 * but allows daddr_t to grow without breaking existing
931 	 * disks.
932 	 *
933 	 * Note that blkno2blkno_buf does not take a size as input,
934 	 * and hence must be called on a pre-zeroed buffer of length
935 	 * greater than or equal to sizeof(daddr_t).
936 	 */
937 	for (i=0; i < sizeof(daddr_t); i++) {
938 		*sbuf++ = blkno & 0xff;
939 		blkno >>= 8;
940 	}
941 }
942 
943 static void
944 cgd_cipher(struct cgd_softc *cs, void *dstv, void *srcv,
945     size_t len, daddr_t blkno, size_t secsize, int dir)
946 {
947 	char		*dst = dstv;
948 	char 		*src = srcv;
949 	cfunc_cipher	*cipher = cs->sc_cfuncs->cf_cipher;
950 	struct uio	dstuio;
951 	struct uio	srcuio;
952 	struct iovec	dstiov[2];
953 	struct iovec	srciov[2];
954 	size_t		blocksize = cs->sc_cdata.cf_blocksize;
955 	size_t		todo;
956 	char		sink[CGD_MAXBLOCKSIZE];
957 	char		zero_iv[CGD_MAXBLOCKSIZE];
958 	char		blkno_buf[CGD_MAXBLOCKSIZE];
959 
960 	DPRINTF_FOLLOW(("cgd_cipher() dir=%d\n", dir));
961 
962 	DIAGCONDPANIC(len % blocksize != 0,
963 	    ("cgd_cipher: len %% blocksize != 0"));
964 
965 	/* ensure that sizeof(daddr_t) <= blocksize (for encblkno IVing) */
966 	DIAGCONDPANIC(sizeof(daddr_t) > blocksize,
967 	    ("cgd_cipher: sizeof(daddr_t) > blocksize"));
968 
969 	memset(zero_iv, 0x0, blocksize);
970 
971 	dstuio.uio_iov = dstiov;
972 	dstuio.uio_iovcnt = 2;
973 
974 	srcuio.uio_iov = srciov;
975 	srcuio.uio_iovcnt = 2;
976 
977 	dstiov[0].iov_base = sink;
978 	dstiov[0].iov_len  = blocksize;
979 	srciov[0].iov_base = blkno_buf;
980 	srciov[0].iov_len  = blocksize;
981 
982 	for (; len > 0; len -= todo) {
983 		todo = MIN(len, secsize);
984 
985 		dstiov[1].iov_base = dst;
986 		srciov[1].iov_base = src;
987 		dstiov[1].iov_len  = todo;
988 		srciov[1].iov_len  = todo;
989 
990 		memset(blkno_buf, 0x0, blocksize);
991 		blkno2blkno_buf(blkno_buf, blkno);
992 		if (dir == CGD_CIPHER_DECRYPT) {
993 			dstuio.uio_iovcnt = 1;
994 			srcuio.uio_iovcnt = 1;
995 			IFDEBUG(CGDB_CRYPTO, hexprint("step 0: blkno_buf",
996 			    blkno_buf, blocksize));
997 			cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio,
998 			    zero_iv, CGD_CIPHER_ENCRYPT);
999 			memcpy(blkno_buf, sink, blocksize);
1000 			dstuio.uio_iovcnt = 2;
1001 			srcuio.uio_iovcnt = 2;
1002 		}
1003 
1004 		IFDEBUG(CGDB_CRYPTO, hexprint("step 1: blkno_buf",
1005 		    blkno_buf, blocksize));
1006 		cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, dir);
1007 		IFDEBUG(CGDB_CRYPTO, hexprint("step 2: sink",
1008 		    sink, blocksize));
1009 
1010 		dst += todo;
1011 		src += todo;
1012 		blkno++;
1013 	}
1014 }
1015 
1016 #ifdef DEBUG
1017 static void
1018 hexprint(const char *start, void *buf, int len)
1019 {
1020 	char	*c = buf;
1021 
1022 	DIAGCONDPANIC(len < 0, ("hexprint: called with len < 0"));
1023 	printf("%s: len=%06d 0x", start, len);
1024 	while (len--)
1025 		printf("%02x", (unsigned char) *c++);
1026 }
1027 #endif
1028 
1029 MODULE(MODULE_CLASS_DRIVER, cgd, "dk_subr");
1030 
1031 #ifdef _MODULE
1032 CFDRIVER_DECL(cgd, DV_DISK, NULL);
1033 
1034 devmajor_t cgd_bmajor = -1, cgd_cmajor = -1;
1035 #endif
1036 
1037 static int
1038 cgd_modcmd(modcmd_t cmd, void *arg)
1039 {
1040 	int error = 0;
1041 
1042 	switch (cmd) {
1043 	case MODULE_CMD_INIT:
1044 #ifdef _MODULE
1045 		error = config_cfdriver_attach(&cgd_cd);
1046 		if (error)
1047 			break;
1048 
1049 		error = config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
1050 	        if (error) {
1051 			config_cfdriver_detach(&cgd_cd);
1052 			aprint_error("%s: unable to register cfattach for"
1053 			    "%s, error %d\n", __func__, cgd_cd.cd_name, error);
1054 			break;
1055 		}
1056 		/*
1057 		 * Attach the {b,c}devsw's
1058 		 */
1059 		error = devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
1060 		    &cgd_cdevsw, &cgd_cmajor);
1061 
1062 		/*
1063 		 * If devsw_attach fails, remove from autoconf database
1064 		 */
1065 		if (error) {
1066 			config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
1067 			config_cfdriver_detach(&cgd_cd);
1068 			aprint_error("%s: unable to attach %s devsw, "
1069 			    "error %d", __func__, cgd_cd.cd_name, error);
1070 			break;
1071 		}
1072 #endif
1073 		break;
1074 
1075 	case MODULE_CMD_FINI:
1076 #ifdef _MODULE
1077 		/*
1078 		 * Remove {b,c}devsw's
1079 		 */
1080 		devsw_detach(&cgd_bdevsw, &cgd_cdevsw);
1081 
1082 		/*
1083 		 * Now remove device from autoconf database
1084 		 */
1085 		error = config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
1086 		if (error) {
1087 			(void)devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
1088 			    &cgd_cdevsw, &cgd_cmajor);
1089 			aprint_error("%s: failed to detach %s cfattach, "
1090 			    "error %d\n", __func__, cgd_cd.cd_name, error);
1091  			break;
1092 		}
1093 		error = config_cfdriver_detach(&cgd_cd);
1094 		if (error) {
1095 			(void)config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
1096 			(void)devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
1097 			    &cgd_cdevsw, &cgd_cmajor);
1098 			aprint_error("%s: failed to detach %s cfdriver, "
1099 			    "error %d\n", __func__, cgd_cd.cd_name, error);
1100 			break;
1101 		}
1102 #endif
1103 		break;
1104 
1105 	case MODULE_CMD_STAT:
1106 		error = ENOTTY;
1107 		break;
1108 	default:
1109 		error = ENOTTY;
1110 		break;
1111 	}
1112 
1113 	return error;
1114 }
1115