xref: /netbsd-src/sys/dev/cgd.c (revision a6f3f22f245acb8ee3bbf6871d7dce989204fa97)
1 /* $NetBSD: cgd.c,v 1.104 2015/08/27 05:51:50 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 1.104 2015/08/27 05:51:50 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 
110 static int	cgd_ioctl_set(struct cgd_softc *, void *, struct lwp *);
111 static int	cgd_ioctl_clr(struct cgd_softc *, struct lwp *);
112 static int	cgd_ioctl_get(dev_t, void *, struct lwp *);
113 static int	cgdinit(struct cgd_softc *, const char *, struct vnode *,
114 			struct lwp *);
115 static void	cgd_cipher(struct cgd_softc *, void *, void *,
116 			   size_t, daddr_t, size_t, int);
117 
118 static struct dkdriver cgddkdriver = {
119         .d_minphys  = minphys,
120         .d_open = cgdopen,
121         .d_close = cgdclose,
122         .d_strategy = cgdstrategy,
123         .d_iosize = NULL,
124         .d_diskstart = cgd_diskstart,
125         .d_dumpblocks = NULL,
126         .d_lastclose = NULL
127 };
128 
129 CFATTACH_DECL3_NEW(cgd, sizeof(struct cgd_softc),
130     cgd_match, cgd_attach, cgd_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN);
131 extern struct cfdriver cgd_cd;
132 
133 /* DIAGNOSTIC and DEBUG definitions */
134 
135 #if defined(CGDDEBUG) && !defined(DEBUG)
136 #define DEBUG
137 #endif
138 
139 #ifdef DEBUG
140 int cgddebug = 0;
141 
142 #define CGDB_FOLLOW	0x1
143 #define CGDB_IO	0x2
144 #define CGDB_CRYPTO	0x4
145 
146 #define IFDEBUG(x,y)		if (cgddebug & (x)) y
147 #define DPRINTF(x,y)		IFDEBUG(x, printf y)
148 #define DPRINTF_FOLLOW(y)	DPRINTF(CGDB_FOLLOW, y)
149 
150 static void	hexprint(const char *, void *, int);
151 
152 #else
153 #define IFDEBUG(x,y)
154 #define DPRINTF(x,y)
155 #define DPRINTF_FOLLOW(y)
156 #endif
157 
158 #ifdef DIAGNOSTIC
159 #define DIAGPANIC(x)		panic x
160 #define DIAGCONDPANIC(x,y)	if (x) panic y
161 #else
162 #define DIAGPANIC(x)
163 #define DIAGCONDPANIC(x,y)
164 #endif
165 
166 /* Global variables */
167 
168 /* Utility Functions */
169 
170 #define CGDUNIT(x)		DISKUNIT(x)
171 #define GETCGD_SOFTC(_cs, x)	if (!((_cs) = getcgd_softc(x))) return ENXIO
172 
173 /* The code */
174 
175 static struct cgd_softc *
176 getcgd_softc(dev_t dev)
177 {
178 	int	unit = CGDUNIT(dev);
179 	struct cgd_softc *sc;
180 
181 	DPRINTF_FOLLOW(("getcgd_softc(0x%"PRIx64"): unit = %d\n", dev, unit));
182 
183 	sc = device_lookup_private(&cgd_cd, unit);
184 	if (sc == NULL)
185 		sc = cgd_spawn(unit);
186 	return sc;
187 }
188 
189 static int
190 cgd_match(device_t self, cfdata_t cfdata, void *aux)
191 {
192 
193 	return 1;
194 }
195 
196 static void
197 cgd_attach(device_t parent, device_t self, void *aux)
198 {
199 	struct cgd_softc *sc = device_private(self);
200 
201 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_BIO);
202 	dk_init(&sc->sc_dksc, self, DKTYPE_CGD);
203 	disk_init(&sc->sc_dksc.sc_dkdev, sc->sc_dksc.sc_xname, &cgddkdriver);
204 
205 	if (!pmf_device_register(self, NULL, NULL))
206 		aprint_error_dev(self, "unable to register power management hooks\n");
207 }
208 
209 
210 static int
211 cgd_detach(device_t self, int flags)
212 {
213 	int ret;
214 	const int pmask = 1 << RAW_PART;
215 	struct cgd_softc *sc = device_private(self);
216 	struct dk_softc *dksc = &sc->sc_dksc;
217 
218 	if (DK_BUSY(dksc, pmask))
219 		return EBUSY;
220 
221 	if (DK_ATTACHED(dksc) &&
222 	    (ret = cgd_ioctl_clr(sc, curlwp)) != 0)
223 		return ret;
224 
225 	disk_destroy(&dksc->sc_dkdev);
226 	mutex_destroy(&sc->sc_lock);
227 
228 	return 0;
229 }
230 
231 void
232 cgdattach(int num)
233 {
234 	int error;
235 
236 	error = config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
237 	if (error != 0)
238 		aprint_error("%s: unable to register cfattach\n",
239 		    cgd_cd.cd_name);
240 }
241 
242 static struct cgd_softc *
243 cgd_spawn(int unit)
244 {
245 	cfdata_t cf;
246 
247 	cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
248 	cf->cf_name = cgd_cd.cd_name;
249 	cf->cf_atname = cgd_cd.cd_name;
250 	cf->cf_unit = unit;
251 	cf->cf_fstate = FSTATE_STAR;
252 
253 	return device_private(config_attach_pseudo(cf));
254 }
255 
256 static int
257 cgd_destroy(device_t dev)
258 {
259 	int error;
260 	cfdata_t cf;
261 
262 	cf = device_cfdata(dev);
263 	error = config_detach(dev, DETACH_QUIET);
264 	if (error)
265 		return error;
266 	free(cf, M_DEVBUF);
267 	return 0;
268 }
269 
270 static int
271 cgdopen(dev_t dev, int flags, int fmt, struct lwp *l)
272 {
273 	struct	cgd_softc *cs;
274 
275 	DPRINTF_FOLLOW(("cgdopen(0x%"PRIx64", %d)\n", dev, flags));
276 	GETCGD_SOFTC(cs, dev);
277 	return dk_open(&cs->sc_dksc, dev, flags, fmt, l);
278 }
279 
280 static int
281 cgdclose(dev_t dev, int flags, int fmt, struct lwp *l)
282 {
283 	int error;
284 	struct	cgd_softc *cs;
285 	struct	dk_softc *dksc;
286 
287 	DPRINTF_FOLLOW(("cgdclose(0x%"PRIx64", %d)\n", dev, flags));
288 	GETCGD_SOFTC(cs, dev);
289 	dksc = &cs->sc_dksc;
290 	if ((error =  dk_close(dksc, dev, flags, fmt, l)) != 0)
291 		return error;
292 
293 	if (!DK_ATTACHED(dksc)) {
294 		if ((error = cgd_destroy(cs->sc_dksc.sc_dev)) != 0) {
295 			aprint_error_dev(dksc->sc_dev,
296 			    "unable to detach instance\n");
297 			return error;
298 		}
299 	}
300 	return 0;
301 }
302 
303 static void
304 cgdstrategy(struct buf *bp)
305 {
306 	struct	cgd_softc *cs = getcgd_softc(bp->b_dev);
307 
308 	DPRINTF_FOLLOW(("cgdstrategy(%p): b_bcount = %ld\n", bp,
309 	    (long)bp->b_bcount));
310 
311 	/*
312 	 * Reject unaligned writes.  We can encrypt and decrypt only
313 	 * complete disk sectors, and we let the ciphers require their
314 	 * buffers to be aligned to 32-bit boundaries.
315 	 */
316 	if (bp->b_blkno < 0 ||
317 	    (bp->b_bcount % DEV_BSIZE) != 0 ||
318 	    ((uintptr_t)bp->b_data & 3) != 0) {
319 		bp->b_error = EINVAL;
320 		bp->b_resid = bp->b_bcount;
321 		biodone(bp);
322 		return;
323 	}
324 
325 	/* XXXrcd: Should we test for (cs != NULL)? */
326 	dk_strategy(&cs->sc_dksc, bp);
327 	return;
328 }
329 
330 static int
331 cgdsize(dev_t dev)
332 {
333 	struct cgd_softc *cs = getcgd_softc(dev);
334 
335 	DPRINTF_FOLLOW(("cgdsize(0x%"PRIx64")\n", dev));
336 	if (!cs)
337 		return -1;
338 	return dk_size(&cs->sc_dksc, dev);
339 }
340 
341 /*
342  * cgd_{get,put}data are functions that deal with getting a buffer
343  * for the new encrypted data.  We have a buffer per device so that
344  * we can ensure that we can always have a transaction in flight.
345  * We use this buffer first so that we have one less piece of
346  * malloc'ed data at any given point.
347  */
348 
349 static void *
350 cgd_getdata(struct dk_softc *dksc, unsigned long size)
351 {
352 	struct	cgd_softc *cs = (struct cgd_softc *)dksc;
353 	void *	data = NULL;
354 
355 	mutex_enter(&cs->sc_lock);
356 	if (cs->sc_data_used == 0) {
357 		cs->sc_data_used = 1;
358 		data = cs->sc_data;
359 	}
360 	mutex_exit(&cs->sc_lock);
361 
362 	if (data)
363 		return data;
364 
365 	return malloc(size, M_DEVBUF, M_NOWAIT);
366 }
367 
368 static void
369 cgd_putdata(struct dk_softc *dksc, void *data)
370 {
371 	struct	cgd_softc *cs = (struct cgd_softc *)dksc;
372 
373 	if (data == cs->sc_data) {
374 		mutex_enter(&cs->sc_lock);
375 		cs->sc_data_used = 0;
376 		mutex_exit(&cs->sc_lock);
377 	} else {
378 		free(data, M_DEVBUF);
379 	}
380 }
381 
382 static int
383 cgd_diskstart(device_t dev, struct buf *bp)
384 {
385 	struct	cgd_softc *cs = device_private(dev);
386 	struct	dk_softc *dksc = &cs->sc_dksc;
387 	struct	buf *nbp;
388 	void *	addr;
389 	void *	newaddr;
390 	daddr_t	bn;
391 	struct	vnode *vp;
392 
393 	DPRINTF_FOLLOW(("cgd_diskstart(%p, %p)\n", dksc, bp));
394 
395 	bn = bp->b_rawblkno;
396 
397 	/*
398 	 * We attempt to allocate all of our resources up front, so that
399 	 * we can fail quickly if they are unavailable.
400 	 */
401 	nbp = getiobuf(cs->sc_tvn, false);
402 	if (nbp == NULL)
403 		return EAGAIN;
404 
405 	/*
406 	 * If we are writing, then we need to encrypt the outgoing
407 	 * block into a new block of memory.
408 	 */
409 	newaddr = addr = bp->b_data;
410 	if ((bp->b_flags & B_READ) == 0) {
411 		newaddr = cgd_getdata(dksc, bp->b_bcount);
412 		if (!newaddr) {
413 			putiobuf(nbp);
414 			return EAGAIN;
415 		}
416 		cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn,
417 		    DEV_BSIZE, CGD_CIPHER_ENCRYPT);
418 	}
419 
420 	nbp->b_data = newaddr;
421 	nbp->b_flags = bp->b_flags;
422 	nbp->b_oflags = bp->b_oflags;
423 	nbp->b_cflags = bp->b_cflags;
424 	nbp->b_iodone = cgdiodone;
425 	nbp->b_proc = bp->b_proc;
426 	nbp->b_blkno = bn;
427 	nbp->b_bcount = bp->b_bcount;
428 	nbp->b_private = bp;
429 
430 	BIO_COPYPRIO(nbp, bp);
431 
432 	if ((nbp->b_flags & B_READ) == 0) {
433 		vp = nbp->b_vp;
434 		mutex_enter(vp->v_interlock);
435 		vp->v_numoutput++;
436 		mutex_exit(vp->v_interlock);
437 	}
438 	VOP_STRATEGY(cs->sc_tvn, nbp);
439 
440 	return 0;
441 }
442 
443 static void
444 cgdiodone(struct buf *nbp)
445 {
446 	struct	buf *obp = nbp->b_private;
447 	struct	cgd_softc *cs = getcgd_softc(obp->b_dev);
448 	struct	dk_softc *dksc = &cs->sc_dksc;
449 
450 	KDASSERT(cs);
451 
452 	DPRINTF_FOLLOW(("cgdiodone(%p)\n", nbp));
453 	DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %d resid %d\n",
454 	    obp, obp->b_bcount, obp->b_resid));
455 	DPRINTF(CGDB_IO, (" dev 0x%"PRIx64", nbp %p bn %" PRId64 " addr %p bcnt %d\n",
456 	    nbp->b_dev, nbp, nbp->b_blkno, nbp->b_data,
457 	    nbp->b_bcount));
458 	if (nbp->b_error != 0) {
459 		obp->b_error = nbp->b_error;
460 		DPRINTF(CGDB_IO, ("%s: error %d\n", dksc->sc_xname,
461 		    obp->b_error));
462 	}
463 
464 	/* Perform the decryption if we are reading.
465 	 *
466 	 * Note: use the blocknumber from nbp, since it is what
467 	 *       we used to encrypt the blocks.
468 	 */
469 
470 	if (nbp->b_flags & B_READ)
471 		cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount,
472 		    nbp->b_blkno, DEV_BSIZE, CGD_CIPHER_DECRYPT);
473 
474 	/* If we allocated memory, free it now... */
475 	if (nbp->b_data != obp->b_data)
476 		cgd_putdata(dksc, nbp->b_data);
477 
478 	putiobuf(nbp);
479 
480 	/* Request is complete for whatever reason */
481 	obp->b_resid = 0;
482 	if (obp->b_error != 0)
483 		obp->b_resid = obp->b_bcount;
484 
485 	dk_done(dksc, obp);
486 	dk_start(dksc, NULL);
487 }
488 
489 /* XXX: we should probably put these into dksubr.c, mostly */
490 static int
491 cgdread(dev_t dev, struct uio *uio, int flags)
492 {
493 	struct	cgd_softc *cs;
494 	struct	dk_softc *dksc;
495 
496 	DPRINTF_FOLLOW(("cgdread(0x%llx, %p, %d)\n",
497 	    (unsigned long long)dev, uio, flags));
498 	GETCGD_SOFTC(cs, dev);
499 	dksc = &cs->sc_dksc;
500 	if (!DK_ATTACHED(dksc))
501 		return ENXIO;
502 	return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio);
503 }
504 
505 /* XXX: we should probably put these into dksubr.c, mostly */
506 static int
507 cgdwrite(dev_t dev, struct uio *uio, int flags)
508 {
509 	struct	cgd_softc *cs;
510 	struct	dk_softc *dksc;
511 
512 	DPRINTF_FOLLOW(("cgdwrite(0x%"PRIx64", %p, %d)\n", dev, uio, flags));
513 	GETCGD_SOFTC(cs, dev);
514 	dksc = &cs->sc_dksc;
515 	if (!DK_ATTACHED(dksc))
516 		return ENXIO;
517 	return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio);
518 }
519 
520 static int
521 cgdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
522 {
523 	struct	cgd_softc *cs;
524 	struct	dk_softc *dksc;
525 	int	part = DISKPART(dev);
526 	int	pmask = 1 << part;
527 
528 	DPRINTF_FOLLOW(("cgdioctl(0x%"PRIx64", %ld, %p, %d, %p)\n",
529 	    dev, cmd, data, flag, l));
530 
531 	switch (cmd) {
532 	case CGDIOCGET:
533 		return cgd_ioctl_get(dev, data, l);
534 	case CGDIOCSET:
535 	case CGDIOCCLR:
536 		if ((flag & FWRITE) == 0)
537 			return EBADF;
538 		/* FALLTHROUGH */
539 	default:
540 		GETCGD_SOFTC(cs, dev);
541 		dksc = &cs->sc_dksc;
542 		break;
543 	}
544 
545 	switch (cmd) {
546 	case CGDIOCSET:
547 		if (DK_ATTACHED(dksc))
548 			return EBUSY;
549 		return cgd_ioctl_set(cs, data, l);
550 	case CGDIOCCLR:
551 		if (DK_BUSY(&cs->sc_dksc, pmask))
552 			return EBUSY;
553 		return cgd_ioctl_clr(cs, l);
554 	case DIOCCACHESYNC:
555 		/*
556 		 * XXX Do we really need to care about having a writable
557 		 * file descriptor here?
558 		 */
559 		if ((flag & FWRITE) == 0)
560 			return (EBADF);
561 
562 		/*
563 		 * We pass this call down to the underlying disk.
564 		 */
565 		return VOP_IOCTL(cs->sc_tvn, cmd, data, flag, l->l_cred);
566 	case DIOCGSTRATEGY:
567 	case DIOCSSTRATEGY:
568 		if (!DK_ATTACHED(dksc))
569 			return ENOENT;
570 		/*FALLTHROUGH*/
571 	default:
572 		return dk_ioctl(dksc, dev, cmd, data, flag, l);
573 	case CGDIOCGET:
574 		KASSERT(0);
575 		return EINVAL;
576 	}
577 }
578 
579 static int
580 cgddump(dev_t dev, daddr_t blkno, void *va, size_t size)
581 {
582 	struct	cgd_softc *cs;
583 
584 	DPRINTF_FOLLOW(("cgddump(0x%"PRIx64", %" PRId64 ", %p, %lu)\n",
585 	    dev, blkno, va, (unsigned long)size));
586 	GETCGD_SOFTC(cs, dev);
587 	return dk_dump(&cs->sc_dksc, dev, blkno, va, size);
588 }
589 
590 /*
591  * XXXrcd:
592  *  for now we hardcode the maximum key length.
593  */
594 #define MAX_KEYSIZE	1024
595 
596 static const struct {
597 	const char *n;
598 	int v;
599 	int d;
600 } encblkno[] = {
601 	{ "encblkno",  CGD_CIPHER_CBC_ENCBLKNO8, 1 },
602 	{ "encblkno8", CGD_CIPHER_CBC_ENCBLKNO8, 1 },
603 	{ "encblkno1", CGD_CIPHER_CBC_ENCBLKNO1, 8 },
604 };
605 
606 /* ARGSUSED */
607 static int
608 cgd_ioctl_set(struct cgd_softc *cs, void *data, struct lwp *l)
609 {
610 	struct	 cgd_ioctl *ci = data;
611 	struct	 vnode *vp;
612 	int	 ret;
613 	size_t	 i;
614 	size_t	 keybytes;			/* key length in bytes */
615 	const char *cp;
616 	struct pathbuf *pb;
617 	char	 *inbuf;
618 	struct dk_softc *dksc = &cs->sc_dksc;
619 
620 	cp = ci->ci_disk;
621 
622 	ret = pathbuf_copyin(ci->ci_disk, &pb);
623 	if (ret != 0) {
624 		return ret;
625 	}
626 	ret = dk_lookup(pb, l, &vp);
627 	pathbuf_destroy(pb);
628 	if (ret != 0) {
629 		return ret;
630 	}
631 
632 	inbuf = malloc(MAX_KEYSIZE, M_TEMP, M_WAITOK);
633 
634 	if ((ret = cgdinit(cs, cp, vp, l)) != 0)
635 		goto bail;
636 
637 	(void)memset(inbuf, 0, MAX_KEYSIZE);
638 	ret = copyinstr(ci->ci_alg, inbuf, 256, NULL);
639 	if (ret)
640 		goto bail;
641 	cs->sc_cfuncs = cryptfuncs_find(inbuf);
642 	if (!cs->sc_cfuncs) {
643 		ret = EINVAL;
644 		goto bail;
645 	}
646 
647 	(void)memset(inbuf, 0, MAX_KEYSIZE);
648 	ret = copyinstr(ci->ci_ivmethod, inbuf, MAX_KEYSIZE, NULL);
649 	if (ret)
650 		goto bail;
651 
652 	for (i = 0; i < __arraycount(encblkno); i++)
653 		if (strcmp(encblkno[i].n, inbuf) == 0)
654 			break;
655 
656 	if (i == __arraycount(encblkno)) {
657 		ret = EINVAL;
658 		goto bail;
659 	}
660 
661 	keybytes = ci->ci_keylen / 8 + 1;
662 	if (keybytes > MAX_KEYSIZE) {
663 		ret = EINVAL;
664 		goto bail;
665 	}
666 
667 	(void)memset(inbuf, 0, MAX_KEYSIZE);
668 	ret = copyin(ci->ci_key, inbuf, keybytes);
669 	if (ret)
670 		goto bail;
671 
672 	cs->sc_cdata.cf_blocksize = ci->ci_blocksize;
673 	cs->sc_cdata.cf_mode = encblkno[i].v;
674 	cs->sc_cdata.cf_keylen = ci->ci_keylen;
675 	cs->sc_cdata.cf_priv = cs->sc_cfuncs->cf_init(ci->ci_keylen, inbuf,
676 	    &cs->sc_cdata.cf_blocksize);
677 	if (cs->sc_cdata.cf_blocksize > CGD_MAXBLOCKSIZE) {
678 	    log(LOG_WARNING, "cgd: Disallowed cipher with blocksize %zu > %u\n",
679 		cs->sc_cdata.cf_blocksize, CGD_MAXBLOCKSIZE);
680 	    cs->sc_cdata.cf_priv = NULL;
681 	}
682 
683 	/*
684 	 * The blocksize is supposed to be in bytes. Unfortunately originally
685 	 * it was expressed in bits. For compatibility we maintain encblkno
686 	 * and encblkno8.
687 	 */
688 	cs->sc_cdata.cf_blocksize /= encblkno[i].d;
689 	(void)explicit_memset(inbuf, 0, MAX_KEYSIZE);
690 	if (!cs->sc_cdata.cf_priv) {
691 		ret = EINVAL;		/* XXX is this the right error? */
692 		goto bail;
693 	}
694 	free(inbuf, M_TEMP);
695 
696 	bufq_alloc(&dksc->sc_bufq, "fcfs", 0);
697 
698 	cs->sc_data = malloc(MAXPHYS, M_DEVBUF, M_WAITOK);
699 	cs->sc_data_used = 0;
700 
701 	/* Attach the disk. */
702 	dk_attach(dksc);
703 	disk_attach(&dksc->sc_dkdev);
704 
705 	disk_set_info(dksc->sc_dev, &dksc->sc_dkdev, NULL);
706 
707 	/* Try and read the disklabel. */
708 	dk_getdisklabel(dksc, 0 /* XXX ? (cause of PR 41704) */);
709 
710 	/* Discover wedges on this disk. */
711 	dkwedge_discover(&dksc->sc_dkdev);
712 
713 	return 0;
714 
715 bail:
716 	free(inbuf, M_TEMP);
717 	(void)vn_close(vp, FREAD|FWRITE, l->l_cred);
718 	return ret;
719 }
720 
721 /* ARGSUSED */
722 static int
723 cgd_ioctl_clr(struct cgd_softc *cs, struct lwp *l)
724 {
725 	struct	dk_softc *dksc = &cs->sc_dksc;
726 
727 	if (!DK_ATTACHED(dksc))
728 		return ENXIO;
729 
730 	/* Delete all of our wedges. */
731 	dkwedge_delall(&dksc->sc_dkdev);
732 
733 	/* Kill off any queued buffers. */
734 	dk_drain(dksc);
735 	bufq_free(dksc->sc_bufq);
736 
737 	(void)vn_close(cs->sc_tvn, FREAD|FWRITE, l->l_cred);
738 	cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv);
739 	free(cs->sc_tpath, M_DEVBUF);
740 	free(cs->sc_data, M_DEVBUF);
741 	cs->sc_data_used = 0;
742 	dk_detach(dksc);
743 	disk_detach(&dksc->sc_dkdev);
744 
745 	return 0;
746 }
747 
748 static int
749 cgd_ioctl_get(dev_t dev, void *data, struct lwp *l)
750 {
751 	struct cgd_softc *cs = getcgd_softc(dev);
752 	struct cgd_user *cgu;
753 	int unit;
754 	struct	dk_softc *dksc = &cs->sc_dksc;
755 
756 	unit = CGDUNIT(dev);
757 	cgu = (struct cgd_user *)data;
758 
759 	DPRINTF_FOLLOW(("cgd_ioctl_get(0x%"PRIx64", %d, %p, %p)\n",
760 			   dev, unit, data, l));
761 
762 	if (cgu->cgu_unit == -1)
763 		cgu->cgu_unit = unit;
764 
765 	if (cgu->cgu_unit < 0)
766 		return EINVAL;	/* XXX: should this be ENXIO? */
767 
768 	cs = device_lookup_private(&cgd_cd, unit);
769 	if (cs == NULL || !DK_ATTACHED(dksc)) {
770 		cgu->cgu_dev = 0;
771 		cgu->cgu_alg[0] = '\0';
772 		cgu->cgu_blocksize = 0;
773 		cgu->cgu_mode = 0;
774 		cgu->cgu_keylen = 0;
775 	}
776 	else {
777 		cgu->cgu_dev = cs->sc_tdev;
778 		strlcpy(cgu->cgu_alg, cs->sc_cfuncs->cf_name,
779 		    sizeof(cgu->cgu_alg));
780 		cgu->cgu_blocksize = cs->sc_cdata.cf_blocksize;
781 		cgu->cgu_mode = cs->sc_cdata.cf_mode;
782 		cgu->cgu_keylen = cs->sc_cdata.cf_keylen;
783 	}
784 	return 0;
785 }
786 
787 static int
788 cgdinit(struct cgd_softc *cs, const char *cpath, struct vnode *vp,
789 	struct lwp *l)
790 {
791 	struct	disk_geom *dg;
792 	int	ret;
793 	char	*tmppath;
794 	uint64_t psize;
795 	unsigned secsize;
796 	struct dk_softc *dksc = &cs->sc_dksc;
797 
798 	cs->sc_tvn = vp;
799 	cs->sc_tpath = NULL;
800 
801 	tmppath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
802 	ret = copyinstr(cpath, tmppath, MAXPATHLEN, &cs->sc_tpathlen);
803 	if (ret)
804 		goto bail;
805 	cs->sc_tpath = malloc(cs->sc_tpathlen, M_DEVBUF, M_WAITOK);
806 	memcpy(cs->sc_tpath, tmppath, cs->sc_tpathlen);
807 
808 	cs->sc_tdev = vp->v_rdev;
809 
810 	if ((ret = getdisksize(vp, &psize, &secsize)) != 0)
811 		goto bail;
812 
813 	if (psize == 0) {
814 		ret = ENODEV;
815 		goto bail;
816 	}
817 
818 	/*
819 	 * XXX here we should probe the underlying device.  If we
820 	 *     are accessing a partition of type RAW_PART, then
821 	 *     we should populate our initial geometry with the
822 	 *     geometry that we discover from the device.
823 	 */
824 	dg = &dksc->sc_dkdev.dk_geom;
825 	memset(dg, 0, sizeof(*dg));
826 	dg->dg_secperunit = psize;
827 	// XXX: Inherit?
828 	dg->dg_secsize = DEV_BSIZE;
829 	dg->dg_ntracks = 1;
830 	dg->dg_nsectors = 1024 * (1024 / dg->dg_secsize);
831 	dg->dg_ncylinders = dg->dg_secperunit / dg->dg_nsectors;
832 
833 bail:
834 	free(tmppath, M_TEMP);
835 	if (ret && cs->sc_tpath)
836 		free(cs->sc_tpath, M_DEVBUF);
837 	return ret;
838 }
839 
840 /*
841  * Our generic cipher entry point.  This takes care of the
842  * IV mode and passes off the work to the specific cipher.
843  * We implement here the IV method ``encrypted block
844  * number''.
845  *
846  * For the encryption case, we accomplish this by setting
847  * up a struct uio where the first iovec of the source is
848  * the blocknumber and the first iovec of the dest is a
849  * sink.  We then call the cipher with an IV of zero, and
850  * the right thing happens.
851  *
852  * For the decryption case, we use the same basic mechanism
853  * for symmetry, but we encrypt the block number in the
854  * first iovec.
855  *
856  * We mainly do this to avoid requiring the definition of
857  * an ECB mode.
858  *
859  * XXXrcd: for now we rely on our own crypto framework defined
860  *         in dev/cgd_crypto.c.  This will change when we
861  *         get a generic kernel crypto framework.
862  */
863 
864 static void
865 blkno2blkno_buf(char *sbuf, daddr_t blkno)
866 {
867 	int	i;
868 
869 	/* Set up the blkno in blkno_buf, here we do not care much
870 	 * about the final layout of the information as long as we
871 	 * can guarantee that each sector will have a different IV
872 	 * and that the endianness of the machine will not affect
873 	 * the representation that we have chosen.
874 	 *
875 	 * We choose this representation, because it does not rely
876 	 * on the size of buf (which is the blocksize of the cipher),
877 	 * but allows daddr_t to grow without breaking existing
878 	 * disks.
879 	 *
880 	 * Note that blkno2blkno_buf does not take a size as input,
881 	 * and hence must be called on a pre-zeroed buffer of length
882 	 * greater than or equal to sizeof(daddr_t).
883 	 */
884 	for (i=0; i < sizeof(daddr_t); i++) {
885 		*sbuf++ = blkno & 0xff;
886 		blkno >>= 8;
887 	}
888 }
889 
890 static void
891 cgd_cipher(struct cgd_softc *cs, void *dstv, void *srcv,
892     size_t len, daddr_t blkno, size_t secsize, int dir)
893 {
894 	char		*dst = dstv;
895 	char 		*src = srcv;
896 	cfunc_cipher	*cipher = cs->sc_cfuncs->cf_cipher;
897 	struct uio	dstuio;
898 	struct uio	srcuio;
899 	struct iovec	dstiov[2];
900 	struct iovec	srciov[2];
901 	size_t		blocksize = cs->sc_cdata.cf_blocksize;
902 	char		sink[CGD_MAXBLOCKSIZE];
903 	char		zero_iv[CGD_MAXBLOCKSIZE];
904 	char		blkno_buf[CGD_MAXBLOCKSIZE];
905 
906 	DPRINTF_FOLLOW(("cgd_cipher() dir=%d\n", dir));
907 
908 	DIAGCONDPANIC(len % blocksize != 0,
909 	    ("cgd_cipher: len %% blocksize != 0"));
910 
911 	/* ensure that sizeof(daddr_t) <= blocksize (for encblkno IVing) */
912 	DIAGCONDPANIC(sizeof(daddr_t) > blocksize,
913 	    ("cgd_cipher: sizeof(daddr_t) > blocksize"));
914 
915 	memset(zero_iv, 0x0, blocksize);
916 
917 	dstuio.uio_iov = dstiov;
918 	dstuio.uio_iovcnt = 2;
919 
920 	srcuio.uio_iov = srciov;
921 	srcuio.uio_iovcnt = 2;
922 
923 	dstiov[0].iov_base = sink;
924 	dstiov[0].iov_len  = blocksize;
925 	srciov[0].iov_base = blkno_buf;
926 	srciov[0].iov_len  = blocksize;
927 	dstiov[1].iov_len  = secsize;
928 	srciov[1].iov_len  = secsize;
929 
930 	for (; len > 0; len -= secsize) {
931 		dstiov[1].iov_base = dst;
932 		srciov[1].iov_base = src;
933 
934 		memset(blkno_buf, 0x0, blocksize);
935 		blkno2blkno_buf(blkno_buf, blkno);
936 		if (dir == CGD_CIPHER_DECRYPT) {
937 			dstuio.uio_iovcnt = 1;
938 			srcuio.uio_iovcnt = 1;
939 			IFDEBUG(CGDB_CRYPTO, hexprint("step 0: blkno_buf",
940 			    blkno_buf, blocksize));
941 			cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio,
942 			    zero_iv, CGD_CIPHER_ENCRYPT);
943 			memcpy(blkno_buf, sink, blocksize);
944 			dstuio.uio_iovcnt = 2;
945 			srcuio.uio_iovcnt = 2;
946 		}
947 
948 		IFDEBUG(CGDB_CRYPTO, hexprint("step 1: blkno_buf",
949 		    blkno_buf, blocksize));
950 		cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, dir);
951 		IFDEBUG(CGDB_CRYPTO, hexprint("step 2: sink",
952 		    sink, blocksize));
953 
954 		dst += secsize;
955 		src += secsize;
956 		blkno++;
957 	}
958 }
959 
960 #ifdef DEBUG
961 static void
962 hexprint(const char *start, void *buf, int len)
963 {
964 	char	*c = buf;
965 
966 	DIAGCONDPANIC(len < 0, ("hexprint: called with len < 0"));
967 	printf("%s: len=%06d 0x", start, len);
968 	while (len--)
969 		printf("%02x", (unsigned char) *c++);
970 }
971 #endif
972 
973 MODULE(MODULE_CLASS_DRIVER, cgd, "dk_subr");
974 
975 #ifdef _MODULE
976 CFDRIVER_DECL(cgd, DV_DISK, NULL);
977 #endif
978 
979 static int
980 cgd_modcmd(modcmd_t cmd, void *arg)
981 {
982 	int error = 0;
983 
984 #ifdef _MODULE
985 	devmajor_t bmajor = -1, cmajor = -1;
986 #endif
987 
988 	switch (cmd) {
989 	case MODULE_CMD_INIT:
990 #ifdef _MODULE
991 		error = config_cfdriver_attach(&cgd_cd);
992 		if (error)
993 			break;
994 
995 		error = config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
996 	        if (error) {
997 			config_cfdriver_detach(&cgd_cd);
998 			aprint_error("%s: unable to register cfattach\n",
999 			    cgd_cd.cd_name);
1000 			break;
1001 		}
1002 
1003 		error = devsw_attach("cgd", &cgd_bdevsw, &bmajor,
1004 		    &cgd_cdevsw, &cmajor);
1005 		if (error) {
1006 			config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
1007 			config_cfdriver_detach(&cgd_cd);
1008 			break;
1009 		}
1010 #endif
1011 		break;
1012 
1013 	case MODULE_CMD_FINI:
1014 #ifdef _MODULE
1015 		error = config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
1016 		if (error)
1017 			break;
1018 		config_cfdriver_detach(&cgd_cd);
1019 		devsw_detach(&cgd_bdevsw, &cgd_cdevsw);
1020 #endif
1021 		break;
1022 
1023 	case MODULE_CMD_STAT:
1024 		return ENOTTY;
1025 
1026 	default:
1027 		return ENOTTY;
1028 	}
1029 
1030 	return error;
1031 }
1032