xref: /netbsd-src/sys/dev/cgd.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /* $NetBSD: cgd.c,v 1.64 2009/11/10 20:39:36 christos 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 1.64 2009/11/10 20:39:36 christos 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 /* Internal Functions */
80 
81 static int	cgdstart(struct dk_softc *, struct buf *);
82 static void	cgdiodone(struct buf *);
83 
84 static int	cgd_ioctl_set(struct cgd_softc *, void *, struct lwp *);
85 static int	cgd_ioctl_clr(struct cgd_softc *, void *, struct lwp *);
86 static int	cgdinit(struct cgd_softc *, const char *, struct vnode *,
87 			struct lwp *);
88 static void	cgd_cipher(struct cgd_softc *, void *, void *,
89 			   size_t, daddr_t, size_t, int);
90 
91 /* Pseudo-disk Interface */
92 
93 static struct dk_intf the_dkintf = {
94 	DTYPE_CGD,
95 	"cgd",
96 	cgdopen,
97 	cgdclose,
98 	cgdstrategy,
99 	cgdstart,
100 };
101 static struct dk_intf *di = &the_dkintf;
102 
103 static struct dkdriver cgddkdriver = {
104 	.d_strategy = cgdstrategy,
105 	.d_minphys = minphys,
106 };
107 
108 /* DIAGNOSTIC and DEBUG definitions */
109 
110 #if defined(CGDDEBUG) && !defined(DEBUG)
111 #define DEBUG
112 #endif
113 
114 #ifdef DEBUG
115 int cgddebug = 0;
116 
117 #define CGDB_FOLLOW	0x1
118 #define CGDB_IO	0x2
119 #define CGDB_CRYPTO	0x4
120 
121 #define IFDEBUG(x,y)		if (cgddebug & (x)) y
122 #define DPRINTF(x,y)		IFDEBUG(x, printf y)
123 #define DPRINTF_FOLLOW(y)	DPRINTF(CGDB_FOLLOW, y)
124 
125 static void	hexprint(const char *, void *, int);
126 
127 #else
128 #define IFDEBUG(x,y)
129 #define DPRINTF(x,y)
130 #define DPRINTF_FOLLOW(y)
131 #endif
132 
133 #ifdef DIAGNOSTIC
134 #define DIAGPANIC(x)		panic x
135 #define DIAGCONDPANIC(x,y)	if (x) panic y
136 #else
137 #define DIAGPANIC(x)
138 #define DIAGCONDPANIC(x,y)
139 #endif
140 
141 /* Global variables */
142 
143 struct	cgd_softc *cgd_softc;
144 int	numcgd = 0;
145 
146 /* Utility Functions */
147 
148 #define CGDUNIT(x)		DISKUNIT(x)
149 #define GETCGD_SOFTC(_cs, x)	if (!((_cs) = getcgd_softc(x))) return ENXIO
150 
151 static struct cgd_softc *
152 getcgd_softc(dev_t dev)
153 {
154 	int	unit = CGDUNIT(dev);
155 
156 	DPRINTF_FOLLOW(("getcgd_softc(0x%"PRIx64"): unit = %d\n", dev, unit));
157 	if (unit >= numcgd)
158 		return NULL;
159 	return &cgd_softc[unit];
160 }
161 
162 /* The code */
163 
164 static void
165 cgdsoftc_init(struct cgd_softc *cs, int num)
166 {
167 	char	sbuf[DK_XNAME_SIZE];
168 
169 	memset(cs, 0x0, sizeof(*cs));
170 	snprintf(sbuf, DK_XNAME_SIZE, "cgd%d", num);
171 	simple_lock_init(&cs->sc_slock);
172 	dk_sc_init(&cs->sc_dksc, cs, sbuf);
173 	disk_init(&cs->sc_dksc.sc_dkdev, cs->sc_dksc.sc_xname, &cgddkdriver);
174 }
175 
176 void
177 cgdattach(int num)
178 {
179 	int	i;
180 
181 	DPRINTF_FOLLOW(("cgdattach(%d)\n", num));
182 	if (num <= 0) {
183 		DIAGPANIC(("cgdattach: count <= 0"));
184 		return;
185 	}
186 
187 	cgd_softc = malloc(num * sizeof(*cgd_softc), M_DEVBUF, M_NOWAIT);
188 	if (!cgd_softc) {
189 		DPRINTF_FOLLOW(("WARNING: unable to malloc(9) memory for %d "
190 		    "crypt disks\n", num));
191 		DIAGPANIC(("cgdattach: cannot malloc(9) enough memory"));
192 		return;
193 	}
194 
195 	numcgd = num;
196 	for (i = 0; i < num; i++)
197 		cgdsoftc_init(&cgd_softc[i], i);
198 }
199 
200 static int
201 cgdopen(dev_t dev, int flags, int fmt, struct lwp *l)
202 {
203 	struct	cgd_softc *cs;
204 
205 	DPRINTF_FOLLOW(("cgdopen(0x%"PRIx64", %d)\n", dev, flags));
206 	GETCGD_SOFTC(cs, dev);
207 	return dk_open(di, &cs->sc_dksc, dev, flags, fmt, l);
208 }
209 
210 static int
211 cgdclose(dev_t dev, int flags, int fmt, struct lwp *l)
212 {
213 	struct	cgd_softc *cs;
214 
215 	DPRINTF_FOLLOW(("cgdclose(0x%"PRIx64", %d)\n", dev, flags));
216 	GETCGD_SOFTC(cs, dev);
217 	return dk_close(di, &cs->sc_dksc, dev, flags, fmt, l);
218 }
219 
220 static void
221 cgdstrategy(struct buf *bp)
222 {
223 	struct	cgd_softc *cs = getcgd_softc(bp->b_dev);
224 
225 	DPRINTF_FOLLOW(("cgdstrategy(%p): b_bcount = %ld\n", bp,
226 	    (long)bp->b_bcount));
227 	/* XXXrcd: Should we test for (cs != NULL)? */
228 	dk_strategy(di, &cs->sc_dksc, bp);
229 	return;
230 }
231 
232 static int
233 cgdsize(dev_t dev)
234 {
235 	struct cgd_softc *cs = getcgd_softc(dev);
236 
237 	DPRINTF_FOLLOW(("cgdsize(0x%"PRIx64")\n", dev));
238 	if (!cs)
239 		return -1;
240 	return dk_size(di, &cs->sc_dksc, dev);
241 }
242 
243 /*
244  * cgd_{get,put}data are functions that deal with getting a buffer
245  * for the new encrypted data.  We have a buffer per device so that
246  * we can ensure that we can always have a transaction in flight.
247  * We use this buffer first so that we have one less piece of
248  * malloc'ed data at any given point.
249  */
250 
251 static void *
252 cgd_getdata(struct dk_softc *dksc, unsigned long size)
253 {
254 	struct	cgd_softc *cs =dksc->sc_osc;
255 	void *	data = NULL;
256 
257 	simple_lock(&cs->sc_slock);
258 	if (cs->sc_data_used == 0) {
259 		cs->sc_data_used = 1;
260 		data = cs->sc_data;
261 	}
262 	simple_unlock(&cs->sc_slock);
263 
264 	if (data)
265 		return data;
266 
267 	return malloc(size, M_DEVBUF, M_NOWAIT);
268 }
269 
270 static void
271 cgd_putdata(struct dk_softc *dksc, void *data)
272 {
273 	struct	cgd_softc *cs =dksc->sc_osc;
274 
275 	if (data == cs->sc_data) {
276 		simple_lock(&cs->sc_slock);
277 		cs->sc_data_used = 0;
278 		simple_unlock(&cs->sc_slock);
279 	} else {
280 		free(data, M_DEVBUF);
281 	}
282 }
283 
284 static int
285 cgdstart(struct dk_softc *dksc, struct buf *bp)
286 {
287 	struct	cgd_softc *cs = dksc->sc_osc;
288 	struct	buf *nbp;
289 	void *	addr;
290 	void *	newaddr;
291 	daddr_t	bn;
292 	struct	vnode *vp;
293 
294 	DPRINTF_FOLLOW(("cgdstart(%p, %p)\n", dksc, bp));
295 	disk_busy(&dksc->sc_dkdev); /* XXX: put in dksubr.c */
296 
297 	bn = bp->b_rawblkno;
298 
299 	/*
300 	 * We attempt to allocate all of our resources up front, so that
301 	 * we can fail quickly if they are unavailable.
302 	 */
303 
304 	nbp = getiobuf(cs->sc_tvn, false);
305 	if (nbp == NULL) {
306 		disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ));
307 		return -1;
308 	}
309 
310 	/*
311 	 * If we are writing, then we need to encrypt the outgoing
312 	 * block into a new block of memory.  If we fail, then we
313 	 * return an error and let the dksubr framework deal with it.
314 	 */
315 	newaddr = addr = bp->b_data;
316 	if ((bp->b_flags & B_READ) == 0) {
317 		newaddr = cgd_getdata(dksc, bp->b_bcount);
318 		if (!newaddr) {
319 			putiobuf(nbp);
320 			disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ));
321 			return -1;
322 		}
323 		cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn,
324 		    DEV_BSIZE, CGD_CIPHER_ENCRYPT);
325 	}
326 
327 	nbp->b_data = newaddr;
328 	nbp->b_flags = bp->b_flags;
329 	nbp->b_oflags = bp->b_oflags;
330 	nbp->b_cflags = bp->b_cflags;
331 	nbp->b_iodone = cgdiodone;
332 	nbp->b_proc = bp->b_proc;
333 	nbp->b_blkno = bn;
334 	nbp->b_bcount = bp->b_bcount;
335 	nbp->b_private = bp;
336 
337 	BIO_COPYPRIO(nbp, bp);
338 
339 	if ((nbp->b_flags & B_READ) == 0) {
340 		vp = nbp->b_vp;
341 		mutex_enter(&vp->v_interlock);
342 		vp->v_numoutput++;
343 		mutex_exit(&vp->v_interlock);
344 	}
345 	VOP_STRATEGY(cs->sc_tvn, nbp);
346 	return 0;
347 }
348 
349 /* expected to be called at splbio() */
350 static void
351 cgdiodone(struct buf *nbp)
352 {
353 	struct	buf *obp = nbp->b_private;
354 	struct	cgd_softc *cs = getcgd_softc(obp->b_dev);
355 	struct	dk_softc *dksc = &cs->sc_dksc;
356 
357 	KDASSERT(cs);
358 
359 	DPRINTF_FOLLOW(("cgdiodone(%p)\n", nbp));
360 	DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %d resid %d\n",
361 	    obp, obp->b_bcount, obp->b_resid));
362 	DPRINTF(CGDB_IO, (" dev 0x%"PRIx64", nbp %p bn %" PRId64 " addr %p bcnt %d\n",
363 	    nbp->b_dev, nbp, nbp->b_blkno, nbp->b_data,
364 	    nbp->b_bcount));
365 	if (nbp->b_error != 0) {
366 		obp->b_error = nbp->b_error;
367 		DPRINTF(CGDB_IO, ("%s: error %d\n", dksc->sc_xname,
368 		    obp->b_error));
369 	}
370 
371 	/* Perform the decryption if we are reading.
372 	 *
373 	 * Note: use the blocknumber from nbp, since it is what
374 	 *       we used to encrypt the blocks.
375 	 */
376 
377 	if (nbp->b_flags & B_READ)
378 		cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount,
379 		    nbp->b_blkno, DEV_BSIZE, CGD_CIPHER_DECRYPT);
380 
381 	/* If we allocated memory, free it now... */
382 	if (nbp->b_data != obp->b_data)
383 		cgd_putdata(dksc, nbp->b_data);
384 
385 	putiobuf(nbp);
386 
387 	/* Request is complete for whatever reason */
388 	obp->b_resid = 0;
389 	if (obp->b_error != 0)
390 		obp->b_resid = obp->b_bcount;
391 	disk_unbusy(&dksc->sc_dkdev, obp->b_bcount - obp->b_resid,
392 	    (obp->b_flags & B_READ));
393 	biodone(obp);
394 	dk_iodone(di, dksc);
395 }
396 
397 /* XXX: we should probably put these into dksubr.c, mostly */
398 static int
399 cgdread(dev_t dev, struct uio *uio, int flags)
400 {
401 	struct	cgd_softc *cs;
402 	struct	dk_softc *dksc;
403 
404 	DPRINTF_FOLLOW(("cgdread(0x%llx, %p, %d)\n",
405 	    (unsigned long long)dev, uio, flags));
406 	GETCGD_SOFTC(cs, dev);
407 	dksc = &cs->sc_dksc;
408 	if ((dksc->sc_flags & DKF_INITED) == 0)
409 		return ENXIO;
410 	return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio);
411 }
412 
413 /* XXX: we should probably put these into dksubr.c, mostly */
414 static int
415 cgdwrite(dev_t dev, struct uio *uio, int flags)
416 {
417 	struct	cgd_softc *cs;
418 	struct	dk_softc *dksc;
419 
420 	DPRINTF_FOLLOW(("cgdwrite(0x%"PRIx64", %p, %d)\n", dev, uio, flags));
421 	GETCGD_SOFTC(cs, dev);
422 	dksc = &cs->sc_dksc;
423 	if ((dksc->sc_flags & DKF_INITED) == 0)
424 		return ENXIO;
425 	return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio);
426 }
427 
428 static int
429 cgdioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
430 {
431 	struct	cgd_softc *cs;
432 	struct	dk_softc *dksc;
433 	struct	disk *dk;
434 	int	ret;
435 	int	part = DISKPART(dev);
436 	int	pmask = 1 << part;
437 
438 	DPRINTF_FOLLOW(("cgdioctl(0x%"PRIx64", %ld, %p, %d, %p)\n",
439 	    dev, cmd, data, flag, l));
440 	GETCGD_SOFTC(cs, dev);
441 	dksc = &cs->sc_dksc;
442 	dk = &dksc->sc_dkdev;
443 	switch (cmd) {
444 	case CGDIOCSET:
445 	case CGDIOCCLR:
446 		if ((flag & FWRITE) == 0)
447 			return EBADF;
448 	}
449 
450 	switch (cmd) {
451 	case CGDIOCSET:
452 		if (dksc->sc_flags & DKF_INITED)
453 			ret = EBUSY;
454 		else
455 			ret = cgd_ioctl_set(cs, data, l);
456 		break;
457 	case CGDIOCCLR:
458 		if (!(dksc->sc_flags & DKF_INITED)) {
459 			ret = ENXIO;
460 			break;
461 		}
462 		if (DK_BUSY(&cs->sc_dksc, pmask)) {
463 			ret = EBUSY;
464 			break;
465 		}
466 		ret = cgd_ioctl_clr(cs, data, l);
467 		break;
468 
469 	case DIOCCACHESYNC:
470 		/*
471 		 * XXX Do we really need to care about having a writable
472 		 * file descriptor here?
473 		 */
474 		if ((flag & FWRITE) == 0)
475 			return (EBADF);
476 
477 		/*
478 		 * We pass this call down to the underlying disk.
479 		 */
480 		ret = VOP_IOCTL(cs->sc_tvn, cmd, data, flag, l->l_cred);
481 		break;
482 
483 	default:
484 		ret = dk_ioctl(di, dksc, dev, cmd, data, flag, l);
485 		break;
486 	}
487 
488 	return ret;
489 }
490 
491 static int
492 cgddump(dev_t dev, daddr_t blkno, void *va, size_t size)
493 {
494 	struct	cgd_softc *cs;
495 
496 	DPRINTF_FOLLOW(("cgddump(0x%"PRIx64", %" PRId64 ", %p, %lu)\n",
497 	    dev, blkno, va, (unsigned long)size));
498 	GETCGD_SOFTC(cs, dev);
499 	return dk_dump(di, &cs->sc_dksc, dev, blkno, va, size);
500 }
501 
502 /*
503  * XXXrcd:
504  *  for now we hardcode the maximum key length.
505  */
506 #define MAX_KEYSIZE	1024
507 
508 static const struct {
509 	const char *n;
510 	int v;
511 	int d;
512 } encblkno[] = {
513 	{ "encblkno",  CGD_CIPHER_CBC_ENCBLKNO8, 1 },
514 	{ "encblkno8", CGD_CIPHER_CBC_ENCBLKNO8, 1 },
515 	{ "encblkno1", CGD_CIPHER_CBC_ENCBLKNO1, 8 },
516 };
517 
518 /* ARGSUSED */
519 static int
520 cgd_ioctl_set(struct cgd_softc *cs, void *data, struct lwp *l)
521 {
522 	struct	 cgd_ioctl *ci = data;
523 	struct	 vnode *vp;
524 	int	 ret;
525 	size_t	 i;
526 	size_t	 keybytes;			/* key length in bytes */
527 	const char *cp;
528 	char	 *inbuf;
529 
530 	cp = ci->ci_disk;
531 	if ((ret = dk_lookup(cp, l, &vp, UIO_USERSPACE)) != 0)
532 		return ret;
533 
534 	inbuf = malloc(MAX_KEYSIZE, M_TEMP, M_WAITOK);
535 
536 	if ((ret = cgdinit(cs, cp, vp, l)) != 0)
537 		goto bail;
538 
539 	(void)memset(inbuf, 0, MAX_KEYSIZE);
540 	ret = copyinstr(ci->ci_alg, inbuf, 256, NULL);
541 	if (ret)
542 		goto bail;
543 	cs->sc_cfuncs = cryptfuncs_find(inbuf);
544 	if (!cs->sc_cfuncs) {
545 		ret = EINVAL;
546 		goto bail;
547 	}
548 
549 	(void)memset(inbuf, 0, MAX_KEYSIZE);
550 	ret = copyinstr(ci->ci_ivmethod, inbuf, MAX_KEYSIZE, NULL);
551 	if (ret)
552 		goto bail;
553 
554 	for (i = 0; i < __arraycount(encblkno); i++)
555 		if (strcmp(encblkno[i].n, inbuf) == 0)
556 			break;
557 
558 	if (i == __arraycount(encblkno)) {
559 		ret = EINVAL;
560 		goto bail;
561 	}
562 
563 	keybytes = ci->ci_keylen / 8 + 1;
564 	if (keybytes > MAX_KEYSIZE) {
565 		ret = EINVAL;
566 		goto bail;
567 	}
568 
569 	(void)memset(inbuf, 0, MAX_KEYSIZE);
570 	ret = copyin(ci->ci_key, inbuf, keybytes);
571 	if (ret)
572 		goto bail;
573 
574 	cs->sc_cdata.cf_blocksize = ci->ci_blocksize;
575 	cs->sc_cdata.cf_mode = encblkno[i].v;
576 	cs->sc_cdata.cf_priv = cs->sc_cfuncs->cf_init(ci->ci_keylen, inbuf,
577 	    &cs->sc_cdata.cf_blocksize);
578 	if (cs->sc_cdata.cf_blocksize > CGD_MAXBLOCKSIZE) {
579 	    log(LOG_WARNING, "cgd: Disallowed cipher with blocksize %zu > %u\n",
580 		cs->sc_cdata.cf_blocksize, CGD_MAXBLOCKSIZE);
581 	    cs->sc_cdata.cf_priv = NULL;
582 	}
583 
584 	/*
585 	 * The blocksize is supposed to be in bytes. Unfortunately originally
586 	 * it was expressed in bits. For compatibility we maintain encblkno
587 	 * and encblkno8.
588 	 */
589 	cs->sc_cdata.cf_blocksize /= encblkno[i].d;
590 	(void)memset(inbuf, 0, MAX_KEYSIZE);
591 	if (!cs->sc_cdata.cf_priv) {
592 		ret = EINVAL;		/* XXX is this the right error? */
593 		goto bail;
594 	}
595 	free(inbuf, M_TEMP);
596 
597 	bufq_alloc(&cs->sc_dksc.sc_bufq, "fcfs", 0);
598 
599 	cs->sc_data = malloc(MAXPHYS, M_DEVBUF, M_WAITOK);
600 	cs->sc_data_used = 0;
601 
602 	cs->sc_dksc.sc_flags |= DKF_INITED;
603 
604 	/* Attach the disk. */
605 	disk_attach(&cs->sc_dksc.sc_dkdev);
606 
607 	/* Try and read the disklabel. */
608 	dk_getdisklabel(di, &cs->sc_dksc, 0 /* XXX ? */);
609 
610 	/* Discover wedges on this disk. */
611 	dkwedge_discover(&cs->sc_dksc.sc_dkdev);
612 
613 	return 0;
614 
615 bail:
616 	free(inbuf, M_TEMP);
617 	(void)vn_close(vp, FREAD|FWRITE, l->l_cred);
618 	return ret;
619 }
620 
621 /* ARGSUSED */
622 static int
623 cgd_ioctl_clr(struct cgd_softc *cs, void *data, struct lwp *l)
624 {
625 	int	s;
626 
627 	/* Delete all of our wedges. */
628 	dkwedge_delall(&cs->sc_dksc.sc_dkdev);
629 
630 	/* Kill off any queued buffers. */
631 	s = splbio();
632 	bufq_drain(cs->sc_dksc.sc_bufq);
633 	splx(s);
634 	bufq_free(cs->sc_dksc.sc_bufq);
635 
636 	(void)vn_close(cs->sc_tvn, FREAD|FWRITE, l->l_cred);
637 	cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv);
638 	free(cs->sc_tpath, M_DEVBUF);
639 	free(cs->sc_data, M_DEVBUF);
640 	cs->sc_data_used = 0;
641 	cs->sc_dksc.sc_flags &= ~DKF_INITED;
642 	disk_detach(&cs->sc_dksc.sc_dkdev);
643 
644 	return 0;
645 }
646 
647 static int
648 getsize(struct lwp *l, struct vnode *vp, size_t *size)
649 {
650 	struct partinfo dpart;
651 	struct dkwedge_info dkw;
652 	int ret;
653 
654 	if ((ret = VOP_IOCTL(vp, DIOCGWEDGEINFO, &dkw, FREAD,
655 	    l->l_cred)) == 0) {
656 		*size = dkw.dkw_size;
657 		return 0;
658 	}
659 
660 	if ((ret = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, l->l_cred)) == 0) {
661 		*size = dpart.part->p_size;
662 		return 0;
663 	}
664 
665 	return ret;
666 }
667 
668 
669 static int
670 cgdinit(struct cgd_softc *cs, const char *cpath, struct vnode *vp,
671 	struct lwp *l)
672 {
673 	struct	dk_geom *pdg;
674 	struct	vattr va;
675 	size_t	size;
676 	int	ret;
677 	char	*tmppath;
678 
679 	cs->sc_dksc.sc_size = 0;
680 	cs->sc_tvn = vp;
681 	cs->sc_tpath = NULL;
682 
683 	tmppath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
684 	ret = copyinstr(cpath, tmppath, MAXPATHLEN, &cs->sc_tpathlen);
685 	if (ret)
686 		goto bail;
687 	cs->sc_tpath = malloc(cs->sc_tpathlen, M_DEVBUF, M_WAITOK);
688 	memcpy(cs->sc_tpath, tmppath, cs->sc_tpathlen);
689 
690 	if ((ret = VOP_GETATTR(vp, &va, l->l_cred)) != 0)
691 		goto bail;
692 
693 	cs->sc_tdev = va.va_rdev;
694 
695 	if ((ret = getsize(l, vp, &size)) != 0)
696 		goto bail;
697 
698 	if (!size) {
699 		ret = ENODEV;
700 		goto bail;
701 	}
702 
703 	cs->sc_dksc.sc_size = size;
704 
705 	/*
706 	 * XXX here we should probe the underlying device.  If we
707 	 *     are accessing a partition of type RAW_PART, then
708 	 *     we should populate our initial geometry with the
709 	 *     geometry that we discover from the device.
710 	 */
711 	pdg = &cs->sc_dksc.sc_geom;
712 	pdg->pdg_secsize = DEV_BSIZE;
713 	pdg->pdg_ntracks = 1;
714 	pdg->pdg_nsectors = 1024 * (1024 / pdg->pdg_secsize);
715 	pdg->pdg_ncylinders = cs->sc_dksc.sc_size / pdg->pdg_nsectors;
716 
717 bail:
718 	free(tmppath, M_TEMP);
719 	if (ret && cs->sc_tpath)
720 		free(cs->sc_tpath, M_DEVBUF);
721 	return ret;
722 }
723 
724 /*
725  * Our generic cipher entry point.  This takes care of the
726  * IV mode and passes off the work to the specific cipher.
727  * We implement here the IV method ``encrypted block
728  * number''.
729  *
730  * For the encryption case, we accomplish this by setting
731  * up a struct uio where the first iovec of the source is
732  * the blocknumber and the first iovec of the dest is a
733  * sink.  We then call the cipher with an IV of zero, and
734  * the right thing happens.
735  *
736  * For the decryption case, we use the same basic mechanism
737  * for symmetry, but we encrypt the block number in the
738  * first iovec.
739  *
740  * We mainly do this to avoid requiring the definition of
741  * an ECB mode.
742  *
743  * XXXrcd: for now we rely on our own crypto framework defined
744  *         in dev/cgd_crypto.c.  This will change when we
745  *         get a generic kernel crypto framework.
746  */
747 
748 static void
749 blkno2blkno_buf(char *sbuf, daddr_t blkno)
750 {
751 	int	i;
752 
753 	/* Set up the blkno in blkno_buf, here we do not care much
754 	 * about the final layout of the information as long as we
755 	 * can guarantee that each sector will have a different IV
756 	 * and that the endianness of the machine will not affect
757 	 * the representation that we have chosen.
758 	 *
759 	 * We choose this representation, because it does not rely
760 	 * on the size of buf (which is the blocksize of the cipher),
761 	 * but allows daddr_t to grow without breaking existing
762 	 * disks.
763 	 *
764 	 * Note that blkno2blkno_buf does not take a size as input,
765 	 * and hence must be called on a pre-zeroed buffer of length
766 	 * greater than or equal to sizeof(daddr_t).
767 	 */
768 	for (i=0; i < sizeof(daddr_t); i++) {
769 		*sbuf++ = blkno & 0xff;
770 		blkno >>= 8;
771 	}
772 }
773 
774 static void
775 cgd_cipher(struct cgd_softc *cs, void *dstv, void *srcv,
776     size_t len, daddr_t blkno, size_t secsize, int dir)
777 {
778 	char		*dst = dstv;
779 	char 		*src = srcv;
780 	cfunc_cipher	*cipher = cs->sc_cfuncs->cf_cipher;
781 	struct uio	dstuio;
782 	struct uio	srcuio;
783 	struct iovec	dstiov[2];
784 	struct iovec	srciov[2];
785 	size_t		blocksize = cs->sc_cdata.cf_blocksize;
786 	char		sink[CGD_MAXBLOCKSIZE];
787 	char		zero_iv[CGD_MAXBLOCKSIZE];
788 	char		blkno_buf[CGD_MAXBLOCKSIZE];
789 
790 	DPRINTF_FOLLOW(("cgd_cipher() dir=%d\n", dir));
791 
792 	DIAGCONDPANIC(len % blocksize != 0,
793 	    ("cgd_cipher: len %% blocksize != 0"));
794 
795 	/* ensure that sizeof(daddr_t) <= blocksize (for encblkno IVing) */
796 	DIAGCONDPANIC(sizeof(daddr_t) > blocksize,
797 	    ("cgd_cipher: sizeof(daddr_t) > blocksize"));
798 
799 	memset(zero_iv, 0x0, blocksize);
800 
801 	dstuio.uio_iov = dstiov;
802 	dstuio.uio_iovcnt = 2;
803 
804 	srcuio.uio_iov = srciov;
805 	srcuio.uio_iovcnt = 2;
806 
807 	dstiov[0].iov_base = sink;
808 	dstiov[0].iov_len  = blocksize;
809 	srciov[0].iov_base = blkno_buf;
810 	srciov[0].iov_len  = blocksize;
811 	dstiov[1].iov_len  = secsize;
812 	srciov[1].iov_len  = secsize;
813 
814 	for (; len > 0; len -= secsize) {
815 		dstiov[1].iov_base = dst;
816 		srciov[1].iov_base = src;
817 
818 		memset(blkno_buf, 0x0, blocksize);
819 		blkno2blkno_buf(blkno_buf, blkno);
820 		if (dir == CGD_CIPHER_DECRYPT) {
821 			dstuio.uio_iovcnt = 1;
822 			srcuio.uio_iovcnt = 1;
823 			IFDEBUG(CGDB_CRYPTO, hexprint("step 0: blkno_buf",
824 			    blkno_buf, blocksize));
825 			cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio,
826 			    zero_iv, CGD_CIPHER_ENCRYPT);
827 			memcpy(blkno_buf, sink, blocksize);
828 			dstuio.uio_iovcnt = 2;
829 			srcuio.uio_iovcnt = 2;
830 		}
831 
832 		IFDEBUG(CGDB_CRYPTO, hexprint("step 1: blkno_buf",
833 		    blkno_buf, blocksize));
834 		cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, dir);
835 		IFDEBUG(CGDB_CRYPTO, hexprint("step 2: sink",
836 		    sink, blocksize));
837 
838 		dst += secsize;
839 		src += secsize;
840 		blkno++;
841 	}
842 }
843 
844 #ifdef DEBUG
845 static void
846 hexprint(const char *start, void *buf, int len)
847 {
848 	char	*c = buf;
849 
850 	DIAGCONDPANIC(len < 0, ("hexprint: called with len < 0"));
851 	printf("%s: len=%06d 0x", start, len);
852 	while (len--)
853 		printf("%02x", (unsigned char) *c++);
854 }
855 #endif
856 
857 #ifdef _MODULE
858 
859 #include <sys/module.h>
860 
861 MODULE(MODULE_CLASS_DRIVER, cgd, NULL);
862 
863 static int
864 cgd_modcmd(modcmd_t cmd, void *arg)
865 {
866 	int bmajor = -1, cmajor = -1,  error = 0;
867 
868 	switch (cmd) {
869 	case MODULE_CMD_INIT:
870 		cgdattach(4);
871 
872 		return devsw_attach("cgd", &cgd_bdevsw, &bmajor,
873 		    &cgd_cdevsw, &cmajor);
874 		break;
875 
876 	case MODULE_CMD_FINI:
877 		return devsw_detach(&cgd_bdevsw, &cgd_cdevsw);
878 		break;
879 
880 	case MODULE_CMD_STAT:
881 		return ENOTTY;
882 
883 	default:
884 		return ENOTTY;
885 	}
886 
887 	return error;
888 }
889 
890 #endif
891