xref: /netbsd-src/sys/dev/cgd.c (revision 7f21db1c0118155e0dd40b75182e30c589d9f63e)
1 /* $NetBSD: cgd.c,v 1.69 2010/01/23 18:31:04 bouyer 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 1.69 2010/01/23 18:31:04 bouyer 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/pool.h>
44 #include <sys/ioctl.h>
45 #include <sys/device.h>
46 #include <sys/disk.h>
47 #include <sys/disklabel.h>
48 #include <sys/fcntl.h>
49 #include <sys/vnode.h>
50 #include <sys/conf.h>
51 #include <sys/syslog.h>
52 
53 #include <dev/dkvar.h>
54 #include <dev/cgdvar.h>
55 
56 /* Entry Point Functions */
57 
58 void	cgdattach(int);
59 
60 static dev_type_open(cgdopen);
61 static dev_type_close(cgdclose);
62 static dev_type_read(cgdread);
63 static dev_type_write(cgdwrite);
64 static dev_type_ioctl(cgdioctl);
65 static dev_type_strategy(cgdstrategy);
66 static dev_type_dump(cgddump);
67 static dev_type_size(cgdsize);
68 
69 const struct bdevsw cgd_bdevsw = {
70 	cgdopen, cgdclose, cgdstrategy, cgdioctl,
71 	cgddump, cgdsize, D_DISK
72 };
73 
74 const struct cdevsw cgd_cdevsw = {
75 	cgdopen, cgdclose, cgdread, cgdwrite, cgdioctl,
76 	nostop, notty, nopoll, nommap, nokqfilter, D_DISK
77 };
78 
79 static int cgd_match(device_t, cfdata_t, void *);
80 static void cgd_attach(device_t, device_t, void *);
81 static int cgd_detach(device_t, int);
82 static struct cgd_softc	*cgd_spawn(int);
83 static int cgd_destroy(device_t);
84 
85 /* Internal Functions */
86 
87 static int	cgdstart(struct dk_softc *, struct buf *);
88 static void	cgdiodone(struct buf *);
89 
90 static int	cgd_ioctl_set(struct cgd_softc *, void *, struct lwp *);
91 static int	cgd_ioctl_clr(struct cgd_softc *, struct lwp *);
92 static int	cgdinit(struct cgd_softc *, const char *, struct vnode *,
93 			struct lwp *);
94 static void	cgd_cipher(struct cgd_softc *, void *, void *,
95 			   size_t, daddr_t, size_t, int);
96 
97 /* Pseudo-disk Interface */
98 
99 static struct dk_intf the_dkintf = {
100 	DTYPE_CGD,
101 	"cgd",
102 	cgdopen,
103 	cgdclose,
104 	cgdstrategy,
105 	cgdstart,
106 };
107 static struct dk_intf *di = &the_dkintf;
108 
109 static struct dkdriver cgddkdriver = {
110 	.d_strategy = cgdstrategy,
111 	.d_minphys = minphys,
112 };
113 
114 CFATTACH_DECL3_NEW(cgd, sizeof(struct cgd_softc),
115     cgd_match, cgd_attach, cgd_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN);
116 extern struct cfdriver cgd_cd;
117 
118 /* DIAGNOSTIC and DEBUG definitions */
119 
120 #if defined(CGDDEBUG) && !defined(DEBUG)
121 #define DEBUG
122 #endif
123 
124 #ifdef DEBUG
125 int cgddebug = 0;
126 
127 #define CGDB_FOLLOW	0x1
128 #define CGDB_IO	0x2
129 #define CGDB_CRYPTO	0x4
130 
131 #define IFDEBUG(x,y)		if (cgddebug & (x)) y
132 #define DPRINTF(x,y)		IFDEBUG(x, printf y)
133 #define DPRINTF_FOLLOW(y)	DPRINTF(CGDB_FOLLOW, y)
134 
135 static void	hexprint(const char *, void *, int);
136 
137 #else
138 #define IFDEBUG(x,y)
139 #define DPRINTF(x,y)
140 #define DPRINTF_FOLLOW(y)
141 #endif
142 
143 #ifdef DIAGNOSTIC
144 #define DIAGPANIC(x)		panic x
145 #define DIAGCONDPANIC(x,y)	if (x) panic y
146 #else
147 #define DIAGPANIC(x)
148 #define DIAGCONDPANIC(x,y)
149 #endif
150 
151 /* Global variables */
152 
153 /* Utility Functions */
154 
155 #define CGDUNIT(x)		DISKUNIT(x)
156 #define GETCGD_SOFTC(_cs, x)	if (!((_cs) = getcgd_softc(x))) return ENXIO
157 
158 /* The code */
159 
160 static struct cgd_softc *
161 getcgd_softc(dev_t dev)
162 {
163 	int	unit = CGDUNIT(dev);
164 	struct cgd_softc *sc;
165 
166 	DPRINTF_FOLLOW(("getcgd_softc(0x%"PRIx64"): unit = %d\n", dev, unit));
167 
168 	sc = device_lookup_private(&cgd_cd, unit);
169 	if (sc == NULL)
170 		sc = cgd_spawn(unit);
171 	return sc;
172 }
173 
174 static int
175 cgd_match(device_t self, cfdata_t cfdata, void *aux)
176 {
177 
178 	return 1;
179 }
180 
181 static void
182 cgd_attach(device_t parent, device_t self, void *aux)
183 {
184 	struct cgd_softc *sc = device_private(self);
185 
186 	sc->sc_dev = self;
187 	simple_lock_init(&sc->sc_slock);
188 	dk_sc_init(&sc->sc_dksc, sc, device_xname(sc->sc_dev));
189 	disk_init(&sc->sc_dksc.sc_dkdev, sc->sc_dksc.sc_xname, &cgddkdriver);
190 }
191 
192 
193 static int
194 cgd_detach(device_t self, int flags)
195 {
196 	int ret;
197 	const int pmask = 1 << RAW_PART;
198 	struct cgd_softc *sc = device_private(self);
199 	struct dk_softc *dksc = &sc->sc_dksc;
200 
201 	if (DK_BUSY(dksc, pmask))
202 		return EBUSY;
203 
204 	if ((dksc->sc_flags & DKF_INITED) != 0 &&
205 	    (ret = cgd_ioctl_clr(sc, curlwp)) != 0)
206 		return ret;
207 
208 	disk_destroy(&dksc->sc_dkdev);
209 
210 	return 0;
211 }
212 
213 void
214 cgdattach(int num)
215 {
216 	int error;
217 
218 	error = config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
219 	if (error != 0)
220 		aprint_error("%s: unable to register cfattach\n",
221 		    cgd_cd.cd_name);
222 }
223 
224 static struct cgd_softc *
225 cgd_spawn(int unit)
226 {
227 	cfdata_t cf;
228 
229 	cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
230 	cf->cf_name = cgd_cd.cd_name;
231 	cf->cf_atname = cgd_cd.cd_name;
232 	cf->cf_unit = unit;
233 	cf->cf_fstate = FSTATE_STAR;
234 
235 	return device_private(config_attach_pseudo(cf));
236 }
237 
238 static int
239 cgd_destroy(device_t dev)
240 {
241 	int error;
242 	cfdata_t cf;
243 
244 	cf = device_cfdata(dev);
245 	error = config_detach(dev, DETACH_QUIET);
246 	if (error)
247 		return error;
248 	free(cf, M_DEVBUF);
249 	return 0;
250 }
251 
252 static int
253 cgdopen(dev_t dev, int flags, int fmt, struct lwp *l)
254 {
255 	struct	cgd_softc *cs;
256 
257 	DPRINTF_FOLLOW(("cgdopen(0x%"PRIx64", %d)\n", dev, flags));
258 	GETCGD_SOFTC(cs, dev);
259 	return dk_open(di, &cs->sc_dksc, dev, flags, fmt, l);
260 }
261 
262 static int
263 cgdclose(dev_t dev, int flags, int fmt, struct lwp *l)
264 {
265 	int error;
266 	struct	cgd_softc *cs;
267 	struct	dk_softc *dksc;
268 
269 	DPRINTF_FOLLOW(("cgdclose(0x%"PRIx64", %d)\n", dev, flags));
270 	GETCGD_SOFTC(cs, dev);
271 	dksc = &cs->sc_dksc;
272 	if ((error =  dk_close(di, dksc, dev, flags, fmt, l)) != 0)
273 		return error;
274 
275 	if ((dksc->sc_flags & DKF_INITED) == 0) {
276 		if ((error = cgd_destroy(cs->sc_dev)) != 0) {
277 			aprint_error_dev(cs->sc_dev,
278 			    "unable to detach instance\n");
279 			return error;
280 		}
281 	}
282 	return 0;
283 }
284 
285 static void
286 cgdstrategy(struct buf *bp)
287 {
288 	struct	cgd_softc *cs = getcgd_softc(bp->b_dev);
289 
290 	DPRINTF_FOLLOW(("cgdstrategy(%p): b_bcount = %ld\n", bp,
291 	    (long)bp->b_bcount));
292 	/* XXXrcd: Should we test for (cs != NULL)? */
293 	dk_strategy(di, &cs->sc_dksc, bp);
294 	return;
295 }
296 
297 static int
298 cgdsize(dev_t dev)
299 {
300 	struct cgd_softc *cs = getcgd_softc(dev);
301 
302 	DPRINTF_FOLLOW(("cgdsize(0x%"PRIx64")\n", dev));
303 	if (!cs)
304 		return -1;
305 	return dk_size(di, &cs->sc_dksc, dev);
306 }
307 
308 /*
309  * cgd_{get,put}data are functions that deal with getting a buffer
310  * for the new encrypted data.  We have a buffer per device so that
311  * we can ensure that we can always have a transaction in flight.
312  * We use this buffer first so that we have one less piece of
313  * malloc'ed data at any given point.
314  */
315 
316 static void *
317 cgd_getdata(struct dk_softc *dksc, unsigned long size)
318 {
319 	struct	cgd_softc *cs =dksc->sc_osc;
320 	void *	data = NULL;
321 
322 	simple_lock(&cs->sc_slock);
323 	if (cs->sc_data_used == 0) {
324 		cs->sc_data_used = 1;
325 		data = cs->sc_data;
326 	}
327 	simple_unlock(&cs->sc_slock);
328 
329 	if (data)
330 		return data;
331 
332 	return malloc(size, M_DEVBUF, M_NOWAIT);
333 }
334 
335 static void
336 cgd_putdata(struct dk_softc *dksc, void *data)
337 {
338 	struct	cgd_softc *cs =dksc->sc_osc;
339 
340 	if (data == cs->sc_data) {
341 		simple_lock(&cs->sc_slock);
342 		cs->sc_data_used = 0;
343 		simple_unlock(&cs->sc_slock);
344 	} else {
345 		free(data, M_DEVBUF);
346 	}
347 }
348 
349 static int
350 cgdstart(struct dk_softc *dksc, struct buf *bp)
351 {
352 	struct	cgd_softc *cs = dksc->sc_osc;
353 	struct	buf *nbp;
354 	void *	addr;
355 	void *	newaddr;
356 	daddr_t	bn;
357 	struct	vnode *vp;
358 
359 	DPRINTF_FOLLOW(("cgdstart(%p, %p)\n", dksc, bp));
360 	disk_busy(&dksc->sc_dkdev); /* XXX: put in dksubr.c */
361 
362 	bn = bp->b_rawblkno;
363 
364 	/*
365 	 * We attempt to allocate all of our resources up front, so that
366 	 * we can fail quickly if they are unavailable.
367 	 */
368 
369 	nbp = getiobuf(cs->sc_tvn, false);
370 	if (nbp == NULL) {
371 		disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ));
372 		return -1;
373 	}
374 
375 	/*
376 	 * If we are writing, then we need to encrypt the outgoing
377 	 * block into a new block of memory.  If we fail, then we
378 	 * return an error and let the dksubr framework deal with it.
379 	 */
380 	newaddr = addr = bp->b_data;
381 	if ((bp->b_flags & B_READ) == 0) {
382 		newaddr = cgd_getdata(dksc, bp->b_bcount);
383 		if (!newaddr) {
384 			putiobuf(nbp);
385 			disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ));
386 			return -1;
387 		}
388 		cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn,
389 		    DEV_BSIZE, CGD_CIPHER_ENCRYPT);
390 	}
391 
392 	nbp->b_data = newaddr;
393 	nbp->b_flags = bp->b_flags;
394 	nbp->b_oflags = bp->b_oflags;
395 	nbp->b_cflags = bp->b_cflags;
396 	nbp->b_iodone = cgdiodone;
397 	nbp->b_proc = bp->b_proc;
398 	nbp->b_blkno = bn;
399 	nbp->b_bcount = bp->b_bcount;
400 	nbp->b_private = bp;
401 
402 	BIO_COPYPRIO(nbp, bp);
403 
404 	if ((nbp->b_flags & B_READ) == 0) {
405 		vp = nbp->b_vp;
406 		mutex_enter(&vp->v_interlock);
407 		vp->v_numoutput++;
408 		mutex_exit(&vp->v_interlock);
409 	}
410 	VOP_STRATEGY(cs->sc_tvn, nbp);
411 	return 0;
412 }
413 
414 static void
415 cgdiodone(struct buf *nbp)
416 {
417 	struct	buf *obp = nbp->b_private;
418 	struct	cgd_softc *cs = getcgd_softc(obp->b_dev);
419 	struct	dk_softc *dksc = &cs->sc_dksc;
420 	int s;
421 
422 	KDASSERT(cs);
423 
424 	DPRINTF_FOLLOW(("cgdiodone(%p)\n", nbp));
425 	DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %d resid %d\n",
426 	    obp, obp->b_bcount, obp->b_resid));
427 	DPRINTF(CGDB_IO, (" dev 0x%"PRIx64", nbp %p bn %" PRId64 " addr %p bcnt %d\n",
428 	    nbp->b_dev, nbp, nbp->b_blkno, nbp->b_data,
429 	    nbp->b_bcount));
430 	if (nbp->b_error != 0) {
431 		obp->b_error = nbp->b_error;
432 		DPRINTF(CGDB_IO, ("%s: error %d\n", dksc->sc_xname,
433 		    obp->b_error));
434 	}
435 
436 	/* Perform the decryption if we are reading.
437 	 *
438 	 * Note: use the blocknumber from nbp, since it is what
439 	 *       we used to encrypt the blocks.
440 	 */
441 
442 	if (nbp->b_flags & B_READ)
443 		cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount,
444 		    nbp->b_blkno, DEV_BSIZE, CGD_CIPHER_DECRYPT);
445 
446 	/* If we allocated memory, free it now... */
447 	if (nbp->b_data != obp->b_data)
448 		cgd_putdata(dksc, nbp->b_data);
449 
450 	putiobuf(nbp);
451 
452 	/* Request is complete for whatever reason */
453 	obp->b_resid = 0;
454 	if (obp->b_error != 0)
455 		obp->b_resid = obp->b_bcount;
456 	s = splbio();
457 	disk_unbusy(&dksc->sc_dkdev, obp->b_bcount - obp->b_resid,
458 	    (obp->b_flags & B_READ));
459 	biodone(obp);
460 	dk_iodone(di, dksc);
461 	splx(s);
462 }
463 
464 /* XXX: we should probably put these into dksubr.c, mostly */
465 static int
466 cgdread(dev_t dev, struct uio *uio, int flags)
467 {
468 	struct	cgd_softc *cs;
469 	struct	dk_softc *dksc;
470 
471 	DPRINTF_FOLLOW(("cgdread(0x%llx, %p, %d)\n",
472 	    (unsigned long long)dev, uio, flags));
473 	GETCGD_SOFTC(cs, dev);
474 	dksc = &cs->sc_dksc;
475 	if ((dksc->sc_flags & DKF_INITED) == 0)
476 		return ENXIO;
477 	return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio);
478 }
479 
480 /* XXX: we should probably put these into dksubr.c, mostly */
481 static int
482 cgdwrite(dev_t dev, struct uio *uio, int flags)
483 {
484 	struct	cgd_softc *cs;
485 	struct	dk_softc *dksc;
486 
487 	DPRINTF_FOLLOW(("cgdwrite(0x%"PRIx64", %p, %d)\n", dev, uio, flags));
488 	GETCGD_SOFTC(cs, dev);
489 	dksc = &cs->sc_dksc;
490 	if ((dksc->sc_flags & DKF_INITED) == 0)
491 		return ENXIO;
492 	return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio);
493 }
494 
495 static int
496 cgdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
497 {
498 	struct	cgd_softc *cs;
499 	struct	dk_softc *dksc;
500 	struct	disk *dk;
501 	int	part = DISKPART(dev);
502 	int	pmask = 1 << part;
503 
504 	DPRINTF_FOLLOW(("cgdioctl(0x%"PRIx64", %ld, %p, %d, %p)\n",
505 	    dev, cmd, data, flag, l));
506 	GETCGD_SOFTC(cs, dev);
507 	dksc = &cs->sc_dksc;
508 	dk = &dksc->sc_dkdev;
509 	switch (cmd) {
510 	case CGDIOCSET:
511 	case CGDIOCCLR:
512 		if ((flag & FWRITE) == 0)
513 			return EBADF;
514 	}
515 
516 	switch (cmd) {
517 	case CGDIOCSET:
518 		if (dksc->sc_flags & DKF_INITED)
519 			return EBUSY;
520 		return cgd_ioctl_set(cs, data, l);
521 	case CGDIOCCLR:
522 		if (DK_BUSY(&cs->sc_dksc, pmask))
523 			return EBUSY;
524 		return cgd_ioctl_clr(cs, l);
525 	case DIOCCACHESYNC:
526 		/*
527 		 * XXX Do we really need to care about having a writable
528 		 * file descriptor here?
529 		 */
530 		if ((flag & FWRITE) == 0)
531 			return (EBADF);
532 
533 		/*
534 		 * We pass this call down to the underlying disk.
535 		 */
536 		return VOP_IOCTL(cs->sc_tvn, cmd, data, flag, l->l_cred);
537 	default:
538 		return dk_ioctl(di, dksc, dev, cmd, data, flag, l);
539 	}
540 }
541 
542 static int
543 cgddump(dev_t dev, daddr_t blkno, void *va, size_t size)
544 {
545 	struct	cgd_softc *cs;
546 
547 	DPRINTF_FOLLOW(("cgddump(0x%"PRIx64", %" PRId64 ", %p, %lu)\n",
548 	    dev, blkno, va, (unsigned long)size));
549 	GETCGD_SOFTC(cs, dev);
550 	return dk_dump(di, &cs->sc_dksc, dev, blkno, va, size);
551 }
552 
553 /*
554  * XXXrcd:
555  *  for now we hardcode the maximum key length.
556  */
557 #define MAX_KEYSIZE	1024
558 
559 static const struct {
560 	const char *n;
561 	int v;
562 	int d;
563 } encblkno[] = {
564 	{ "encblkno",  CGD_CIPHER_CBC_ENCBLKNO8, 1 },
565 	{ "encblkno8", CGD_CIPHER_CBC_ENCBLKNO8, 1 },
566 	{ "encblkno1", CGD_CIPHER_CBC_ENCBLKNO1, 8 },
567 };
568 
569 /* ARGSUSED */
570 static int
571 cgd_ioctl_set(struct cgd_softc *cs, void *data, struct lwp *l)
572 {
573 	struct	 cgd_ioctl *ci = data;
574 	struct	 vnode *vp;
575 	int	 ret;
576 	size_t	 i;
577 	size_t	 keybytes;			/* key length in bytes */
578 	const char *cp;
579 	char	 *inbuf;
580 
581 	cp = ci->ci_disk;
582 	if ((ret = dk_lookup(cp, l, &vp, UIO_USERSPACE)) != 0)
583 		return ret;
584 
585 	inbuf = malloc(MAX_KEYSIZE, M_TEMP, M_WAITOK);
586 
587 	if ((ret = cgdinit(cs, cp, vp, l)) != 0)
588 		goto bail;
589 
590 	(void)memset(inbuf, 0, MAX_KEYSIZE);
591 	ret = copyinstr(ci->ci_alg, inbuf, 256, NULL);
592 	if (ret)
593 		goto bail;
594 	cs->sc_cfuncs = cryptfuncs_find(inbuf);
595 	if (!cs->sc_cfuncs) {
596 		ret = EINVAL;
597 		goto bail;
598 	}
599 
600 	(void)memset(inbuf, 0, MAX_KEYSIZE);
601 	ret = copyinstr(ci->ci_ivmethod, inbuf, MAX_KEYSIZE, NULL);
602 	if (ret)
603 		goto bail;
604 
605 	for (i = 0; i < __arraycount(encblkno); i++)
606 		if (strcmp(encblkno[i].n, inbuf) == 0)
607 			break;
608 
609 	if (i == __arraycount(encblkno)) {
610 		ret = EINVAL;
611 		goto bail;
612 	}
613 
614 	keybytes = ci->ci_keylen / 8 + 1;
615 	if (keybytes > MAX_KEYSIZE) {
616 		ret = EINVAL;
617 		goto bail;
618 	}
619 
620 	(void)memset(inbuf, 0, MAX_KEYSIZE);
621 	ret = copyin(ci->ci_key, inbuf, keybytes);
622 	if (ret)
623 		goto bail;
624 
625 	cs->sc_cdata.cf_blocksize = ci->ci_blocksize;
626 	cs->sc_cdata.cf_mode = encblkno[i].v;
627 	cs->sc_cdata.cf_priv = cs->sc_cfuncs->cf_init(ci->ci_keylen, inbuf,
628 	    &cs->sc_cdata.cf_blocksize);
629 	if (cs->sc_cdata.cf_blocksize > CGD_MAXBLOCKSIZE) {
630 	    log(LOG_WARNING, "cgd: Disallowed cipher with blocksize %zu > %u\n",
631 		cs->sc_cdata.cf_blocksize, CGD_MAXBLOCKSIZE);
632 	    cs->sc_cdata.cf_priv = NULL;
633 	}
634 
635 	/*
636 	 * The blocksize is supposed to be in bytes. Unfortunately originally
637 	 * it was expressed in bits. For compatibility we maintain encblkno
638 	 * and encblkno8.
639 	 */
640 	cs->sc_cdata.cf_blocksize /= encblkno[i].d;
641 	(void)memset(inbuf, 0, MAX_KEYSIZE);
642 	if (!cs->sc_cdata.cf_priv) {
643 		ret = EINVAL;		/* XXX is this the right error? */
644 		goto bail;
645 	}
646 	free(inbuf, M_TEMP);
647 
648 	bufq_alloc(&cs->sc_dksc.sc_bufq, "fcfs", 0);
649 
650 	cs->sc_data = malloc(MAXPHYS, M_DEVBUF, M_WAITOK);
651 	cs->sc_data_used = 0;
652 
653 	cs->sc_dksc.sc_flags |= DKF_INITED;
654 
655 	/* Attach the disk. */
656 	disk_attach(&cs->sc_dksc.sc_dkdev);
657 
658 	/* Try and read the disklabel. */
659 	dk_getdisklabel(di, &cs->sc_dksc, 0 /* XXX ? (cause of PR 41704) */);
660 
661 	/* Discover wedges on this disk. */
662 	dkwedge_discover(&cs->sc_dksc.sc_dkdev);
663 
664 	return 0;
665 
666 bail:
667 	free(inbuf, M_TEMP);
668 	(void)vn_close(vp, FREAD|FWRITE, l->l_cred);
669 	return ret;
670 }
671 
672 /* ARGSUSED */
673 static int
674 cgd_ioctl_clr(struct cgd_softc *cs, struct lwp *l)
675 {
676 	int	s;
677 	struct	dk_softc *dksc;
678 
679 	dksc = &cs->sc_dksc;
680 
681 	if ((dksc->sc_flags & DKF_INITED) == 0)
682 		return ENXIO;
683 
684 	/* Delete all of our wedges. */
685 	dkwedge_delall(&cs->sc_dksc.sc_dkdev);
686 
687 	/* Kill off any queued buffers. */
688 	s = splbio();
689 	bufq_drain(cs->sc_dksc.sc_bufq);
690 	splx(s);
691 	bufq_free(cs->sc_dksc.sc_bufq);
692 
693 	(void)vn_close(cs->sc_tvn, FREAD|FWRITE, l->l_cred);
694 	cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv);
695 	free(cs->sc_tpath, M_DEVBUF);
696 	free(cs->sc_data, M_DEVBUF);
697 	cs->sc_data_used = 0;
698 	cs->sc_dksc.sc_flags &= ~DKF_INITED;
699 	disk_detach(&cs->sc_dksc.sc_dkdev);
700 
701 	return 0;
702 }
703 
704 static int
705 getsize(struct lwp *l, struct vnode *vp, size_t *size)
706 {
707 	struct partinfo dpart;
708 	struct dkwedge_info dkw;
709 	int ret;
710 
711 	if ((ret = VOP_IOCTL(vp, DIOCGWEDGEINFO, &dkw, FREAD,
712 	    l->l_cred)) == 0) {
713 		*size = dkw.dkw_size;
714 		return 0;
715 	}
716 
717 	if ((ret = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, l->l_cred)) == 0) {
718 		*size = dpart.part->p_size;
719 		return 0;
720 	}
721 
722 	return ret;
723 }
724 
725 
726 static int
727 cgdinit(struct cgd_softc *cs, const char *cpath, struct vnode *vp,
728 	struct lwp *l)
729 {
730 	struct	dk_geom *pdg;
731 	struct	vattr va;
732 	size_t	size;
733 	int	ret;
734 	char	*tmppath;
735 
736 	cs->sc_dksc.sc_size = 0;
737 	cs->sc_tvn = vp;
738 	cs->sc_tpath = NULL;
739 
740 	tmppath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
741 	ret = copyinstr(cpath, tmppath, MAXPATHLEN, &cs->sc_tpathlen);
742 	if (ret)
743 		goto bail;
744 	cs->sc_tpath = malloc(cs->sc_tpathlen, M_DEVBUF, M_WAITOK);
745 	memcpy(cs->sc_tpath, tmppath, cs->sc_tpathlen);
746 
747 	if ((ret = VOP_GETATTR(vp, &va, l->l_cred)) != 0)
748 		goto bail;
749 
750 	cs->sc_tdev = va.va_rdev;
751 
752 	if ((ret = getsize(l, vp, &size)) != 0)
753 		goto bail;
754 
755 	if (!size) {
756 		ret = ENODEV;
757 		goto bail;
758 	}
759 
760 	cs->sc_dksc.sc_size = size;
761 
762 	/*
763 	 * XXX here we should probe the underlying device.  If we
764 	 *     are accessing a partition of type RAW_PART, then
765 	 *     we should populate our initial geometry with the
766 	 *     geometry that we discover from the device.
767 	 */
768 	pdg = &cs->sc_dksc.sc_geom;
769 	pdg->pdg_secsize = DEV_BSIZE;
770 	pdg->pdg_ntracks = 1;
771 	pdg->pdg_nsectors = 1024 * (1024 / pdg->pdg_secsize);
772 	pdg->pdg_ncylinders = cs->sc_dksc.sc_size / pdg->pdg_nsectors;
773 
774 bail:
775 	free(tmppath, M_TEMP);
776 	if (ret && cs->sc_tpath)
777 		free(cs->sc_tpath, M_DEVBUF);
778 	return ret;
779 }
780 
781 /*
782  * Our generic cipher entry point.  This takes care of the
783  * IV mode and passes off the work to the specific cipher.
784  * We implement here the IV method ``encrypted block
785  * number''.
786  *
787  * For the encryption case, we accomplish this by setting
788  * up a struct uio where the first iovec of the source is
789  * the blocknumber and the first iovec of the dest is a
790  * sink.  We then call the cipher with an IV of zero, and
791  * the right thing happens.
792  *
793  * For the decryption case, we use the same basic mechanism
794  * for symmetry, but we encrypt the block number in the
795  * first iovec.
796  *
797  * We mainly do this to avoid requiring the definition of
798  * an ECB mode.
799  *
800  * XXXrcd: for now we rely on our own crypto framework defined
801  *         in dev/cgd_crypto.c.  This will change when we
802  *         get a generic kernel crypto framework.
803  */
804 
805 static void
806 blkno2blkno_buf(char *sbuf, daddr_t blkno)
807 {
808 	int	i;
809 
810 	/* Set up the blkno in blkno_buf, here we do not care much
811 	 * about the final layout of the information as long as we
812 	 * can guarantee that each sector will have a different IV
813 	 * and that the endianness of the machine will not affect
814 	 * the representation that we have chosen.
815 	 *
816 	 * We choose this representation, because it does not rely
817 	 * on the size of buf (which is the blocksize of the cipher),
818 	 * but allows daddr_t to grow without breaking existing
819 	 * disks.
820 	 *
821 	 * Note that blkno2blkno_buf does not take a size as input,
822 	 * and hence must be called on a pre-zeroed buffer of length
823 	 * greater than or equal to sizeof(daddr_t).
824 	 */
825 	for (i=0; i < sizeof(daddr_t); i++) {
826 		*sbuf++ = blkno & 0xff;
827 		blkno >>= 8;
828 	}
829 }
830 
831 static void
832 cgd_cipher(struct cgd_softc *cs, void *dstv, void *srcv,
833     size_t len, daddr_t blkno, size_t secsize, int dir)
834 {
835 	char		*dst = dstv;
836 	char 		*src = srcv;
837 	cfunc_cipher	*cipher = cs->sc_cfuncs->cf_cipher;
838 	struct uio	dstuio;
839 	struct uio	srcuio;
840 	struct iovec	dstiov[2];
841 	struct iovec	srciov[2];
842 	size_t		blocksize = cs->sc_cdata.cf_blocksize;
843 	char		sink[CGD_MAXBLOCKSIZE];
844 	char		zero_iv[CGD_MAXBLOCKSIZE];
845 	char		blkno_buf[CGD_MAXBLOCKSIZE];
846 
847 	DPRINTF_FOLLOW(("cgd_cipher() dir=%d\n", dir));
848 
849 	DIAGCONDPANIC(len % blocksize != 0,
850 	    ("cgd_cipher: len %% blocksize != 0"));
851 
852 	/* ensure that sizeof(daddr_t) <= blocksize (for encblkno IVing) */
853 	DIAGCONDPANIC(sizeof(daddr_t) > blocksize,
854 	    ("cgd_cipher: sizeof(daddr_t) > blocksize"));
855 
856 	memset(zero_iv, 0x0, blocksize);
857 
858 	dstuio.uio_iov = dstiov;
859 	dstuio.uio_iovcnt = 2;
860 
861 	srcuio.uio_iov = srciov;
862 	srcuio.uio_iovcnt = 2;
863 
864 	dstiov[0].iov_base = sink;
865 	dstiov[0].iov_len  = blocksize;
866 	srciov[0].iov_base = blkno_buf;
867 	srciov[0].iov_len  = blocksize;
868 	dstiov[1].iov_len  = secsize;
869 	srciov[1].iov_len  = secsize;
870 
871 	for (; len > 0; len -= secsize) {
872 		dstiov[1].iov_base = dst;
873 		srciov[1].iov_base = src;
874 
875 		memset(blkno_buf, 0x0, blocksize);
876 		blkno2blkno_buf(blkno_buf, blkno);
877 		if (dir == CGD_CIPHER_DECRYPT) {
878 			dstuio.uio_iovcnt = 1;
879 			srcuio.uio_iovcnt = 1;
880 			IFDEBUG(CGDB_CRYPTO, hexprint("step 0: blkno_buf",
881 			    blkno_buf, blocksize));
882 			cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio,
883 			    zero_iv, CGD_CIPHER_ENCRYPT);
884 			memcpy(blkno_buf, sink, blocksize);
885 			dstuio.uio_iovcnt = 2;
886 			srcuio.uio_iovcnt = 2;
887 		}
888 
889 		IFDEBUG(CGDB_CRYPTO, hexprint("step 1: blkno_buf",
890 		    blkno_buf, blocksize));
891 		cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, dir);
892 		IFDEBUG(CGDB_CRYPTO, hexprint("step 2: sink",
893 		    sink, blocksize));
894 
895 		dst += secsize;
896 		src += secsize;
897 		blkno++;
898 	}
899 }
900 
901 #ifdef DEBUG
902 static void
903 hexprint(const char *start, void *buf, int len)
904 {
905 	char	*c = buf;
906 
907 	DIAGCONDPANIC(len < 0, ("hexprint: called with len < 0"));
908 	printf("%s: len=%06d 0x", start, len);
909 	while (len--)
910 		printf("%02x", (unsigned char) *c++);
911 }
912 #endif
913 
914 #ifdef _MODULE
915 
916 #include <sys/module.h>
917 
918 MODULE(MODULE_CLASS_DRIVER, cgd, NULL);
919 CFDRIVER_DECL(cgd, DV_DISK, NULL);
920 
921 static int
922 cgd_modcmd(modcmd_t cmd, void *arg)
923 {
924 	int bmajor = -1, cmajor = -1,  error = 0;
925 
926 	switch (cmd) {
927 	case MODULE_CMD_INIT:
928 		error = config_cfdriver_attach(&cgd_cd);
929 		if (error)
930 			break;
931 
932 		error = config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
933 	        if (error) {
934 			config_cfdriver_detach(&cgd_cd);
935 			aprint_error("%s: unable to register cfattach\n",
936 			    cgd_cd.cd_name);
937 			break;
938 		}
939 
940 		error = devsw_attach("cgd", &cgd_bdevsw, &bmajor,
941 		    &cgd_cdevsw, &cmajor);
942 		if (error) {
943 			config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
944 			config_cfdriver_detach(&cgd_cd);
945 			break;
946 		}
947 
948 		break;
949 
950 	case MODULE_CMD_FINI:
951 		error = config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
952 		if (error)
953 			break;
954 		config_cfdriver_detach(&cgd_cd);
955 		devsw_detach(&cgd_bdevsw, &cgd_cdevsw);
956 		break;
957 
958 	case MODULE_CMD_STAT:
959 		return ENOTTY;
960 
961 	default:
962 		return ENOTTY;
963 	}
964 
965 	return error;
966 }
967 
968 #endif
969