xref: /netbsd-src/sys/dev/cgd.c (revision d909946ca08dceb44d7d0f22ec9488679695d976)
1 /* $NetBSD: cgd.c,v 1.110 2016/08/05 08:24:46 pgoyette 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 1.110 2016/08/05 08:24:46 pgoyette 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 = getcgd_softc(bp->b_dev);
309 	struct	dk_softc *dksc = &cs->sc_dksc;
310 	struct	disk_geom *dg = &dksc->sc_dkdev.dk_geom;
311 
312 	DPRINTF_FOLLOW(("cgdstrategy(%p): b_bcount = %ld\n", bp,
313 	    (long)bp->b_bcount));
314 
315 	/*
316 	 * Reject unaligned writes.  We can encrypt and decrypt only
317 	 * complete disk sectors, and we let the ciphers require their
318 	 * buffers to be aligned to 32-bit boundaries.
319 	 */
320 	if (bp->b_blkno < 0 ||
321 	    (bp->b_bcount % dg->dg_secsize) != 0 ||
322 	    ((uintptr_t)bp->b_data & 3) != 0) {
323 		bp->b_error = EINVAL;
324 		bp->b_resid = bp->b_bcount;
325 		biodone(bp);
326 		return;
327 	}
328 
329 	/* XXXrcd: Should we test for (cs != NULL)? */
330 	dk_strategy(&cs->sc_dksc, bp);
331 	return;
332 }
333 
334 static int
335 cgdsize(dev_t dev)
336 {
337 	struct cgd_softc *cs = getcgd_softc(dev);
338 
339 	DPRINTF_FOLLOW(("cgdsize(0x%"PRIx64")\n", dev));
340 	if (!cs)
341 		return -1;
342 	return dk_size(&cs->sc_dksc, dev);
343 }
344 
345 /*
346  * cgd_{get,put}data are functions that deal with getting a buffer
347  * for the new encrypted data.  We have a buffer per device so that
348  * we can ensure that we can always have a transaction in flight.
349  * We use this buffer first so that we have one less piece of
350  * malloc'ed data at any given point.
351  */
352 
353 static void *
354 cgd_getdata(struct dk_softc *dksc, unsigned long size)
355 {
356 	struct	cgd_softc *cs = (struct cgd_softc *)dksc;
357 	void *	data = NULL;
358 
359 	mutex_enter(&cs->sc_lock);
360 	if (cs->sc_data_used == 0) {
361 		cs->sc_data_used = 1;
362 		data = cs->sc_data;
363 	}
364 	mutex_exit(&cs->sc_lock);
365 
366 	if (data)
367 		return data;
368 
369 	return malloc(size, M_DEVBUF, M_NOWAIT);
370 }
371 
372 static void
373 cgd_putdata(struct dk_softc *dksc, void *data)
374 {
375 	struct	cgd_softc *cs = (struct cgd_softc *)dksc;
376 
377 	if (data == cs->sc_data) {
378 		mutex_enter(&cs->sc_lock);
379 		cs->sc_data_used = 0;
380 		mutex_exit(&cs->sc_lock);
381 	} else {
382 		free(data, M_DEVBUF);
383 	}
384 }
385 
386 static int
387 cgd_diskstart(device_t dev, struct buf *bp)
388 {
389 	struct	cgd_softc *cs = device_private(dev);
390 	struct	dk_softc *dksc = &cs->sc_dksc;
391 	struct	disk_geom *dg = &dksc->sc_dkdev.dk_geom;
392 	struct	buf *nbp;
393 	void *	addr;
394 	void *	newaddr;
395 	daddr_t	bn;
396 	struct	vnode *vp;
397 
398 	DPRINTF_FOLLOW(("cgd_diskstart(%p, %p)\n", dksc, bp));
399 
400 	bn = bp->b_rawblkno;
401 
402 	/*
403 	 * We attempt to allocate all of our resources up front, so that
404 	 * we can fail quickly if they are unavailable.
405 	 */
406 	nbp = getiobuf(cs->sc_tvn, false);
407 	if (nbp == NULL)
408 		return EAGAIN;
409 
410 	/*
411 	 * If we are writing, then we need to encrypt the outgoing
412 	 * block into a new block of memory.
413 	 */
414 	newaddr = addr = bp->b_data;
415 	if ((bp->b_flags & B_READ) == 0) {
416 		newaddr = cgd_getdata(dksc, bp->b_bcount);
417 		if (!newaddr) {
418 			putiobuf(nbp);
419 			return EAGAIN;
420 		}
421 		cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn,
422 		    dg->dg_secsize, CGD_CIPHER_ENCRYPT);
423 	}
424 
425 	nbp->b_data = newaddr;
426 	nbp->b_flags = bp->b_flags;
427 	nbp->b_oflags = bp->b_oflags;
428 	nbp->b_cflags = bp->b_cflags;
429 	nbp->b_iodone = cgdiodone;
430 	nbp->b_proc = bp->b_proc;
431 	nbp->b_blkno = btodb(bn * dg->dg_secsize);
432 	nbp->b_bcount = bp->b_bcount;
433 	nbp->b_private = bp;
434 
435 	BIO_COPYPRIO(nbp, bp);
436 
437 	if ((nbp->b_flags & B_READ) == 0) {
438 		vp = nbp->b_vp;
439 		mutex_enter(vp->v_interlock);
440 		vp->v_numoutput++;
441 		mutex_exit(vp->v_interlock);
442 	}
443 	VOP_STRATEGY(cs->sc_tvn, nbp);
444 
445 	return 0;
446 }
447 
448 static void
449 cgdiodone(struct buf *nbp)
450 {
451 	struct	buf *obp = nbp->b_private;
452 	struct	cgd_softc *cs = getcgd_softc(obp->b_dev);
453 	struct	dk_softc *dksc = &cs->sc_dksc;
454 	struct	disk_geom *dg = &dksc->sc_dkdev.dk_geom;
455 	daddr_t	bn;
456 
457 	KDASSERT(cs);
458 
459 	DPRINTF_FOLLOW(("cgdiodone(%p)\n", nbp));
460 	DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %d resid %d\n",
461 	    obp, obp->b_bcount, obp->b_resid));
462 	DPRINTF(CGDB_IO, (" dev 0x%"PRIx64", nbp %p bn %" PRId64
463 	    " addr %p bcnt %d\n", nbp->b_dev, nbp, nbp->b_blkno, nbp->b_data,
464 		nbp->b_bcount));
465 	if (nbp->b_error != 0) {
466 		obp->b_error = nbp->b_error;
467 		DPRINTF(CGDB_IO, ("%s: error %d\n", dksc->sc_xname,
468 		    obp->b_error));
469 	}
470 
471 	/* Perform the decryption if we are reading.
472 	 *
473 	 * Note: use the blocknumber from nbp, since it is what
474 	 *       we used to encrypt the blocks.
475 	 */
476 
477 	if (nbp->b_flags & B_READ) {
478 		bn = dbtob(nbp->b_blkno) / dg->dg_secsize;
479 		cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount,
480 		    bn, dg->dg_secsize, CGD_CIPHER_DECRYPT);
481 	}
482 
483 	/* If we allocated memory, free it now... */
484 	if (nbp->b_data != obp->b_data)
485 		cgd_putdata(dksc, nbp->b_data);
486 
487 	putiobuf(nbp);
488 
489 	/* Request is complete for whatever reason */
490 	obp->b_resid = 0;
491 	if (obp->b_error != 0)
492 		obp->b_resid = obp->b_bcount;
493 
494 	dk_done(dksc, obp);
495 	dk_start(dksc, NULL);
496 }
497 
498 static int
499 cgd_dumpblocks(device_t dev, void *va, daddr_t blkno, int nblk)
500 {
501 	struct cgd_softc *sc = device_private(dev);
502 	struct dk_softc *dksc = &sc->sc_dksc;
503 	struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;
504 	size_t nbytes, blksize;
505 	void *buf;
506 	int error;
507 
508 	/*
509 	 * dk_dump gives us units of disklabel sectors.  Everything
510 	 * else in cgd uses units of diskgeom sectors.  These had
511 	 * better agree; otherwise we need to figure out how to convert
512 	 * between them.
513 	 */
514 	KASSERTMSG((dg->dg_secsize == dksc->sc_dkdev.dk_label->d_secsize),
515 	    "diskgeom secsize %"PRIu32" != disklabel secsize %"PRIu32,
516 	    dg->dg_secsize, dksc->sc_dkdev.dk_label->d_secsize);
517 	blksize = dg->dg_secsize;
518 
519 	/*
520 	 * Compute the number of bytes in this request, which dk_dump
521 	 * has `helpfully' converted to a number of blocks for us.
522 	 */
523 	nbytes = nblk*blksize;
524 
525 	/* Try to acquire a buffer to store the ciphertext.  */
526 	buf = cgd_getdata(dksc, nbytes);
527 	if (buf == NULL)
528 		/* Out of memory: give up.  */
529 		return ENOMEM;
530 
531 	/* Encrypt the caller's data into the temporary buffer.  */
532 	cgd_cipher(sc, buf, va, nbytes, blkno, blksize, CGD_CIPHER_ENCRYPT);
533 
534 	/* Pass it on to the underlying disk device.  */
535 	error = bdev_dump(sc->sc_tdev, blkno, buf, nbytes);
536 
537 	/* Release the buffer.  */
538 	cgd_putdata(dksc, buf);
539 
540 	/* Return any error from the underlying disk device.  */
541 	return error;
542 }
543 
544 /* XXX: we should probably put these into dksubr.c, mostly */
545 static int
546 cgdread(dev_t dev, struct uio *uio, int flags)
547 {
548 	struct	cgd_softc *cs;
549 	struct	dk_softc *dksc;
550 
551 	DPRINTF_FOLLOW(("cgdread(0x%llx, %p, %d)\n",
552 	    (unsigned long long)dev, uio, flags));
553 	GETCGD_SOFTC(cs, dev);
554 	dksc = &cs->sc_dksc;
555 	if (!DK_ATTACHED(dksc))
556 		return ENXIO;
557 	return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio);
558 }
559 
560 /* XXX: we should probably put these into dksubr.c, mostly */
561 static int
562 cgdwrite(dev_t dev, struct uio *uio, int flags)
563 {
564 	struct	cgd_softc *cs;
565 	struct	dk_softc *dksc;
566 
567 	DPRINTF_FOLLOW(("cgdwrite(0x%"PRIx64", %p, %d)\n", dev, uio, flags));
568 	GETCGD_SOFTC(cs, dev);
569 	dksc = &cs->sc_dksc;
570 	if (!DK_ATTACHED(dksc))
571 		return ENXIO;
572 	return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio);
573 }
574 
575 static int
576 cgdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
577 {
578 	struct	cgd_softc *cs;
579 	struct	dk_softc *dksc;
580 	int	part = DISKPART(dev);
581 	int	pmask = 1 << part;
582 
583 	DPRINTF_FOLLOW(("cgdioctl(0x%"PRIx64", %ld, %p, %d, %p)\n",
584 	    dev, cmd, data, flag, l));
585 
586 	switch (cmd) {
587 	case CGDIOCGET:
588 		return cgd_ioctl_get(dev, data, l);
589 	case CGDIOCSET:
590 	case CGDIOCCLR:
591 		if ((flag & FWRITE) == 0)
592 			return EBADF;
593 		/* FALLTHROUGH */
594 	default:
595 		GETCGD_SOFTC(cs, dev);
596 		dksc = &cs->sc_dksc;
597 		break;
598 	}
599 
600 	switch (cmd) {
601 	case CGDIOCSET:
602 		if (DK_ATTACHED(dksc))
603 			return EBUSY;
604 		return cgd_ioctl_set(cs, data, l);
605 	case CGDIOCCLR:
606 		if (DK_BUSY(&cs->sc_dksc, pmask))
607 			return EBUSY;
608 		return cgd_ioctl_clr(cs, l);
609 	case DIOCCACHESYNC:
610 		/*
611 		 * XXX Do we really need to care about having a writable
612 		 * file descriptor here?
613 		 */
614 		if ((flag & FWRITE) == 0)
615 			return (EBADF);
616 
617 		/*
618 		 * We pass this call down to the underlying disk.
619 		 */
620 		return VOP_IOCTL(cs->sc_tvn, cmd, data, flag, l->l_cred);
621 	case DIOCGSTRATEGY:
622 	case DIOCSSTRATEGY:
623 		if (!DK_ATTACHED(dksc))
624 			return ENOENT;
625 		/*FALLTHROUGH*/
626 	default:
627 		return dk_ioctl(dksc, dev, cmd, data, flag, l);
628 	case CGDIOCGET:
629 		KASSERT(0);
630 		return EINVAL;
631 	}
632 }
633 
634 static int
635 cgddump(dev_t dev, daddr_t blkno, void *va, size_t size)
636 {
637 	struct	cgd_softc *cs;
638 
639 	DPRINTF_FOLLOW(("cgddump(0x%"PRIx64", %" PRId64 ", %p, %lu)\n",
640 	    dev, blkno, va, (unsigned long)size));
641 	GETCGD_SOFTC(cs, dev);
642 	return dk_dump(&cs->sc_dksc, dev, blkno, va, size);
643 }
644 
645 /*
646  * XXXrcd:
647  *  for now we hardcode the maximum key length.
648  */
649 #define MAX_KEYSIZE	1024
650 
651 static const struct {
652 	const char *n;
653 	int v;
654 	int d;
655 } encblkno[] = {
656 	{ "encblkno",  CGD_CIPHER_CBC_ENCBLKNO8, 1 },
657 	{ "encblkno8", CGD_CIPHER_CBC_ENCBLKNO8, 1 },
658 	{ "encblkno1", CGD_CIPHER_CBC_ENCBLKNO1, 8 },
659 };
660 
661 /* ARGSUSED */
662 static int
663 cgd_ioctl_set(struct cgd_softc *cs, void *data, struct lwp *l)
664 {
665 	struct	 cgd_ioctl *ci = data;
666 	struct	 vnode *vp;
667 	int	 ret;
668 	size_t	 i;
669 	size_t	 keybytes;			/* key length in bytes */
670 	const char *cp;
671 	struct pathbuf *pb;
672 	char	 *inbuf;
673 	struct dk_softc *dksc = &cs->sc_dksc;
674 
675 	cp = ci->ci_disk;
676 
677 	ret = pathbuf_copyin(ci->ci_disk, &pb);
678 	if (ret != 0) {
679 		return ret;
680 	}
681 	ret = dk_lookup(pb, l, &vp);
682 	pathbuf_destroy(pb);
683 	if (ret != 0) {
684 		return ret;
685 	}
686 
687 	inbuf = malloc(MAX_KEYSIZE, M_TEMP, M_WAITOK);
688 
689 	if ((ret = cgdinit(cs, cp, vp, l)) != 0)
690 		goto bail;
691 
692 	(void)memset(inbuf, 0, MAX_KEYSIZE);
693 	ret = copyinstr(ci->ci_alg, inbuf, 256, NULL);
694 	if (ret)
695 		goto bail;
696 	cs->sc_cfuncs = cryptfuncs_find(inbuf);
697 	if (!cs->sc_cfuncs) {
698 		ret = EINVAL;
699 		goto bail;
700 	}
701 
702 	(void)memset(inbuf, 0, MAX_KEYSIZE);
703 	ret = copyinstr(ci->ci_ivmethod, inbuf, MAX_KEYSIZE, NULL);
704 	if (ret)
705 		goto bail;
706 
707 	for (i = 0; i < __arraycount(encblkno); i++)
708 		if (strcmp(encblkno[i].n, inbuf) == 0)
709 			break;
710 
711 	if (i == __arraycount(encblkno)) {
712 		ret = EINVAL;
713 		goto bail;
714 	}
715 
716 	keybytes = ci->ci_keylen / 8 + 1;
717 	if (keybytes > MAX_KEYSIZE) {
718 		ret = EINVAL;
719 		goto bail;
720 	}
721 
722 	(void)memset(inbuf, 0, MAX_KEYSIZE);
723 	ret = copyin(ci->ci_key, inbuf, keybytes);
724 	if (ret)
725 		goto bail;
726 
727 	cs->sc_cdata.cf_blocksize = ci->ci_blocksize;
728 	cs->sc_cdata.cf_mode = encblkno[i].v;
729 	cs->sc_cdata.cf_keylen = ci->ci_keylen;
730 	cs->sc_cdata.cf_priv = cs->sc_cfuncs->cf_init(ci->ci_keylen, inbuf,
731 	    &cs->sc_cdata.cf_blocksize);
732 	if (cs->sc_cdata.cf_blocksize > CGD_MAXBLOCKSIZE) {
733 	    log(LOG_WARNING, "cgd: Disallowed cipher with blocksize %zu > %u\n",
734 		cs->sc_cdata.cf_blocksize, CGD_MAXBLOCKSIZE);
735 	    cs->sc_cdata.cf_priv = NULL;
736 	}
737 
738 	/*
739 	 * The blocksize is supposed to be in bytes. Unfortunately originally
740 	 * it was expressed in bits. For compatibility we maintain encblkno
741 	 * and encblkno8.
742 	 */
743 	cs->sc_cdata.cf_blocksize /= encblkno[i].d;
744 	(void)explicit_memset(inbuf, 0, MAX_KEYSIZE);
745 	if (!cs->sc_cdata.cf_priv) {
746 		ret = EINVAL;		/* XXX is this the right error? */
747 		goto bail;
748 	}
749 	free(inbuf, M_TEMP);
750 
751 	bufq_alloc(&dksc->sc_bufq, "fcfs", 0);
752 
753 	cs->sc_data = malloc(MAXPHYS, M_DEVBUF, M_WAITOK);
754 	cs->sc_data_used = 0;
755 
756 	/* Attach the disk. */
757 	dk_attach(dksc);
758 	disk_attach(&dksc->sc_dkdev);
759 
760 	disk_set_info(dksc->sc_dev, &dksc->sc_dkdev, NULL);
761 
762 	/* Discover wedges on this disk. */
763 	dkwedge_discover(&dksc->sc_dkdev);
764 
765 	return 0;
766 
767 bail:
768 	free(inbuf, M_TEMP);
769 	(void)vn_close(vp, FREAD|FWRITE, l->l_cred);
770 	return ret;
771 }
772 
773 /* ARGSUSED */
774 static int
775 cgd_ioctl_clr(struct cgd_softc *cs, struct lwp *l)
776 {
777 	struct	dk_softc *dksc = &cs->sc_dksc;
778 
779 	if (!DK_ATTACHED(dksc))
780 		return ENXIO;
781 
782 	/* Delete all of our wedges. */
783 	dkwedge_delall(&dksc->sc_dkdev);
784 
785 	/* Kill off any queued buffers. */
786 	dk_drain(dksc);
787 	bufq_free(dksc->sc_bufq);
788 
789 	(void)vn_close(cs->sc_tvn, FREAD|FWRITE, l->l_cred);
790 	cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv);
791 	free(cs->sc_tpath, M_DEVBUF);
792 	free(cs->sc_data, M_DEVBUF);
793 	cs->sc_data_used = 0;
794 	dk_detach(dksc);
795 	disk_detach(&dksc->sc_dkdev);
796 
797 	return 0;
798 }
799 
800 static int
801 cgd_ioctl_get(dev_t dev, void *data, struct lwp *l)
802 {
803 	struct cgd_softc *cs = getcgd_softc(dev);
804 	struct cgd_user *cgu;
805 	int unit;
806 	struct	dk_softc *dksc = &cs->sc_dksc;
807 
808 	unit = CGDUNIT(dev);
809 	cgu = (struct cgd_user *)data;
810 
811 	DPRINTF_FOLLOW(("cgd_ioctl_get(0x%"PRIx64", %d, %p, %p)\n",
812 			   dev, unit, data, l));
813 
814 	if (cgu->cgu_unit == -1)
815 		cgu->cgu_unit = unit;
816 
817 	if (cgu->cgu_unit < 0)
818 		return EINVAL;	/* XXX: should this be ENXIO? */
819 
820 	cs = device_lookup_private(&cgd_cd, unit);
821 	if (cs == NULL || !DK_ATTACHED(dksc)) {
822 		cgu->cgu_dev = 0;
823 		cgu->cgu_alg[0] = '\0';
824 		cgu->cgu_blocksize = 0;
825 		cgu->cgu_mode = 0;
826 		cgu->cgu_keylen = 0;
827 	}
828 	else {
829 		cgu->cgu_dev = cs->sc_tdev;
830 		strlcpy(cgu->cgu_alg, cs->sc_cfuncs->cf_name,
831 		    sizeof(cgu->cgu_alg));
832 		cgu->cgu_blocksize = cs->sc_cdata.cf_blocksize;
833 		cgu->cgu_mode = cs->sc_cdata.cf_mode;
834 		cgu->cgu_keylen = cs->sc_cdata.cf_keylen;
835 	}
836 	return 0;
837 }
838 
839 static int
840 cgdinit(struct cgd_softc *cs, const char *cpath, struct vnode *vp,
841 	struct lwp *l)
842 {
843 	struct	disk_geom *dg;
844 	int	ret;
845 	char	*tmppath;
846 	uint64_t psize;
847 	unsigned secsize;
848 	struct dk_softc *dksc = &cs->sc_dksc;
849 
850 	cs->sc_tvn = vp;
851 	cs->sc_tpath = NULL;
852 
853 	tmppath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
854 	ret = copyinstr(cpath, tmppath, MAXPATHLEN, &cs->sc_tpathlen);
855 	if (ret)
856 		goto bail;
857 	cs->sc_tpath = malloc(cs->sc_tpathlen, M_DEVBUF, M_WAITOK);
858 	memcpy(cs->sc_tpath, tmppath, cs->sc_tpathlen);
859 
860 	cs->sc_tdev = vp->v_rdev;
861 
862 	if ((ret = getdisksize(vp, &psize, &secsize)) != 0)
863 		goto bail;
864 
865 	if (psize == 0) {
866 		ret = ENODEV;
867 		goto bail;
868 	}
869 
870 	/*
871 	 * XXX here we should probe the underlying device.  If we
872 	 *     are accessing a partition of type RAW_PART, then
873 	 *     we should populate our initial geometry with the
874 	 *     geometry that we discover from the device.
875 	 */
876 	dg = &dksc->sc_dkdev.dk_geom;
877 	memset(dg, 0, sizeof(*dg));
878 	dg->dg_secperunit = psize;
879 	dg->dg_secsize = secsize;
880 	dg->dg_ntracks = 1;
881 	dg->dg_nsectors = 1024 * 1024 / dg->dg_secsize;
882 	dg->dg_ncylinders = dg->dg_secperunit / dg->dg_nsectors;
883 
884 bail:
885 	free(tmppath, M_TEMP);
886 	if (ret && cs->sc_tpath)
887 		free(cs->sc_tpath, M_DEVBUF);
888 	return ret;
889 }
890 
891 /*
892  * Our generic cipher entry point.  This takes care of the
893  * IV mode and passes off the work to the specific cipher.
894  * We implement here the IV method ``encrypted block
895  * number''.
896  *
897  * For the encryption case, we accomplish this by setting
898  * up a struct uio where the first iovec of the source is
899  * the blocknumber and the first iovec of the dest is a
900  * sink.  We then call the cipher with an IV of zero, and
901  * the right thing happens.
902  *
903  * For the decryption case, we use the same basic mechanism
904  * for symmetry, but we encrypt the block number in the
905  * first iovec.
906  *
907  * We mainly do this to avoid requiring the definition of
908  * an ECB mode.
909  *
910  * XXXrcd: for now we rely on our own crypto framework defined
911  *         in dev/cgd_crypto.c.  This will change when we
912  *         get a generic kernel crypto framework.
913  */
914 
915 static void
916 blkno2blkno_buf(char *sbuf, daddr_t blkno)
917 {
918 	int	i;
919 
920 	/* Set up the blkno in blkno_buf, here we do not care much
921 	 * about the final layout of the information as long as we
922 	 * can guarantee that each sector will have a different IV
923 	 * and that the endianness of the machine will not affect
924 	 * the representation that we have chosen.
925 	 *
926 	 * We choose this representation, because it does not rely
927 	 * on the size of buf (which is the blocksize of the cipher),
928 	 * but allows daddr_t to grow without breaking existing
929 	 * disks.
930 	 *
931 	 * Note that blkno2blkno_buf does not take a size as input,
932 	 * and hence must be called on a pre-zeroed buffer of length
933 	 * greater than or equal to sizeof(daddr_t).
934 	 */
935 	for (i=0; i < sizeof(daddr_t); i++) {
936 		*sbuf++ = blkno & 0xff;
937 		blkno >>= 8;
938 	}
939 }
940 
941 static void
942 cgd_cipher(struct cgd_softc *cs, void *dstv, void *srcv,
943     size_t len, daddr_t blkno, size_t secsize, int dir)
944 {
945 	char		*dst = dstv;
946 	char 		*src = srcv;
947 	cfunc_cipher	*cipher = cs->sc_cfuncs->cf_cipher;
948 	struct uio	dstuio;
949 	struct uio	srcuio;
950 	struct iovec	dstiov[2];
951 	struct iovec	srciov[2];
952 	size_t		blocksize = cs->sc_cdata.cf_blocksize;
953 	size_t		todo;
954 	char		sink[CGD_MAXBLOCKSIZE];
955 	char		zero_iv[CGD_MAXBLOCKSIZE];
956 	char		blkno_buf[CGD_MAXBLOCKSIZE];
957 
958 	DPRINTF_FOLLOW(("cgd_cipher() dir=%d\n", dir));
959 
960 	DIAGCONDPANIC(len % blocksize != 0,
961 	    ("cgd_cipher: len %% blocksize != 0"));
962 
963 	/* ensure that sizeof(daddr_t) <= blocksize (for encblkno IVing) */
964 	DIAGCONDPANIC(sizeof(daddr_t) > blocksize,
965 	    ("cgd_cipher: sizeof(daddr_t) > blocksize"));
966 
967 	memset(zero_iv, 0x0, blocksize);
968 
969 	dstuio.uio_iov = dstiov;
970 	dstuio.uio_iovcnt = 2;
971 
972 	srcuio.uio_iov = srciov;
973 	srcuio.uio_iovcnt = 2;
974 
975 	dstiov[0].iov_base = sink;
976 	dstiov[0].iov_len  = blocksize;
977 	srciov[0].iov_base = blkno_buf;
978 	srciov[0].iov_len  = blocksize;
979 
980 	for (; len > 0; len -= todo) {
981 		todo = MIN(len, secsize);
982 
983 		dstiov[1].iov_base = dst;
984 		srciov[1].iov_base = src;
985 		dstiov[1].iov_len  = todo;
986 		srciov[1].iov_len  = todo;
987 
988 		memset(blkno_buf, 0x0, blocksize);
989 		blkno2blkno_buf(blkno_buf, blkno);
990 		if (dir == CGD_CIPHER_DECRYPT) {
991 			dstuio.uio_iovcnt = 1;
992 			srcuio.uio_iovcnt = 1;
993 			IFDEBUG(CGDB_CRYPTO, hexprint("step 0: blkno_buf",
994 			    blkno_buf, blocksize));
995 			cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio,
996 			    zero_iv, CGD_CIPHER_ENCRYPT);
997 			memcpy(blkno_buf, sink, blocksize);
998 			dstuio.uio_iovcnt = 2;
999 			srcuio.uio_iovcnt = 2;
1000 		}
1001 
1002 		IFDEBUG(CGDB_CRYPTO, hexprint("step 1: blkno_buf",
1003 		    blkno_buf, blocksize));
1004 		cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, dir);
1005 		IFDEBUG(CGDB_CRYPTO, hexprint("step 2: sink",
1006 		    sink, blocksize));
1007 
1008 		dst += todo;
1009 		src += todo;
1010 		blkno++;
1011 	}
1012 }
1013 
1014 #ifdef DEBUG
1015 static void
1016 hexprint(const char *start, void *buf, int len)
1017 {
1018 	char	*c = buf;
1019 
1020 	DIAGCONDPANIC(len < 0, ("hexprint: called with len < 0"));
1021 	printf("%s: len=%06d 0x", start, len);
1022 	while (len--)
1023 		printf("%02x", (unsigned char) *c++);
1024 }
1025 #endif
1026 
1027 MODULE(MODULE_CLASS_DRIVER, cgd, "dk_subr");
1028 
1029 #ifdef _MODULE
1030 CFDRIVER_DECL(cgd, DV_DISK, NULL);
1031 
1032 devmajor_t cgd_bmajor = -1, cgd_cmajor = -1;
1033 #endif
1034 
1035 static int
1036 cgd_modcmd(modcmd_t cmd, void *arg)
1037 {
1038 	int error = 0;
1039 
1040 	switch (cmd) {
1041 	case MODULE_CMD_INIT:
1042 #ifdef _MODULE
1043 		error = config_cfdriver_attach(&cgd_cd);
1044 		if (error)
1045 			break;
1046 
1047 		error = config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
1048 	        if (error) {
1049 			config_cfdriver_detach(&cgd_cd);
1050 			aprint_error("%s: unable to register cfattach for"
1051 			    "%s, error %d\n", __func__, cgd_cd.cd_name, error);
1052 			break;
1053 		}
1054 		/*
1055 		 * Attach the {b,c}devsw's
1056 		 */
1057 		error = devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
1058 		    &cgd_cdevsw, &cgd_cmajor);
1059 
1060 		/*
1061 		 * If devsw_attach fails, remove from autoconf database
1062 		 */
1063 		if (error) {
1064 			config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
1065 			config_cfdriver_detach(&cgd_cd);
1066 			aprint_error("%s: unable to attach %s devsw, "
1067 			    "error %d", __func__, cgd_cd.cd_name, error);
1068 			break;
1069 		}
1070 #endif
1071 		break;
1072 
1073 	case MODULE_CMD_FINI:
1074 #ifdef _MODULE
1075 		/*
1076 		 * Remove {b,c}devsw's
1077 		 */
1078 		devsw_detach(&cgd_bdevsw, &cgd_cdevsw);
1079 
1080 		/*
1081 		 * Now remove device from autoconf database
1082 		 */
1083 		error = config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
1084 		if (error) {
1085 			(void)devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
1086 			    &cgd_cdevsw, &cgd_cmajor);
1087 			aprint_error("%s: failed to detach %s cfattach, "
1088 			    "error %d\n", __func__, cgd_cd.cd_name, error);
1089  			break;
1090 		}
1091 		error = config_cfdriver_detach(&cgd_cd);
1092 		if (error) {
1093 			(void)config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
1094 			(void)devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
1095 			    &cgd_cdevsw, &cgd_cmajor);
1096 			aprint_error("%s: failed to detach %s cfdriver, "
1097 			    "error %d\n", __func__, cgd_cd.cd_name, error);
1098 			break;
1099 		}
1100 #endif
1101 		break;
1102 
1103 	case MODULE_CMD_STAT:
1104 		error = ENOTTY;
1105 		break;
1106 	default:
1107 		error = ENOTTY;
1108 		break;
1109 	}
1110 
1111 	return error;
1112 }
1113