FreeBSD/Linux Kernel Cross Reference
sys/dev/cgd.c
1 /* $NetBSD: cgd.c,v 1.22.2.2 2005/04/06 11:58:58 tron 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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: cgd.c,v 1.22.2.2 2005/04/06 11:58:58 tron Exp $");
41
42 #include <sys/types.h>
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/proc.h>
46 #include <sys/errno.h>
47 #include <sys/buf.h>
48 #include <sys/bufq.h>
49 #include <sys/malloc.h>
50 #include <sys/pool.h>
51 #include <sys/ioctl.h>
52 #include <sys/device.h>
53 #include <sys/disk.h>
54 #include <sys/disklabel.h>
55 #include <sys/fcntl.h>
56 #include <sys/vnode.h>
57 #include <sys/lock.h>
58 #include <sys/conf.h>
59
60 #include <dev/dkvar.h>
61 #include <dev/cgdvar.h>
62
63 /* Entry Point Functions */
64
65 void cgdattach(int);
66
67 static dev_type_open(cgdopen);
68 static dev_type_close(cgdclose);
69 static dev_type_read(cgdread);
70 static dev_type_write(cgdwrite);
71 static dev_type_ioctl(cgdioctl);
72 static dev_type_strategy(cgdstrategy);
73 static dev_type_dump(cgddump);
74 static dev_type_size(cgdsize);
75
76 const struct bdevsw cgd_bdevsw = {
77 cgdopen, cgdclose, cgdstrategy, cgdioctl,
78 cgddump, cgdsize, D_DISK
79 };
80
81 const struct cdevsw cgd_cdevsw = {
82 cgdopen, cgdclose, cgdread, cgdwrite, cgdioctl,
83 nostop, notty, nopoll, nommap, nokqfilter, D_DISK
84 };
85
86 /* Internal Functions */
87
88 static int cgdstart(struct dk_softc *, struct buf *);
89 static void cgdiodone(struct buf *);
90
91 static int cgd_ioctl_set(struct cgd_softc *, void *, struct proc *);
92 static int cgd_ioctl_clr(struct cgd_softc *, void *, struct proc *);
93 static int cgdinit(struct cgd_softc *, char *, struct vnode *,
94 struct proc *);
95 static void cgd_cipher(struct cgd_softc *, caddr_t, caddr_t,
96 size_t, daddr_t, size_t, int);
97
98 /* Pseudo-disk Interface */
99
100 static struct dk_intf the_dkintf = {
101 DTYPE_CGD,
102 "cgd",
103 cgdopen,
104 cgdclose,
105 cgdstrategy,
106 cgdstart,
107 };
108 static struct dk_intf *di = &the_dkintf;
109
110 /* DIAGNOSTIC and DEBUG definitions */
111
112 #if defined(CGDDEBUG) && !defined(DEBUG)
113 #define DEBUG
114 #endif
115
116 #ifdef DEBUG
117 int cgddebug = 0;
118
119 #define CGDB_FOLLOW 0x1
120 #define CGDB_IO 0x2
121 #define CGDB_CRYPTO 0x4
122
123 #define IFDEBUG(x,y) if (cgddebug & (x)) y
124 #define DPRINTF(x,y) IFDEBUG(x, printf y)
125 #define DPRINTF_FOLLOW(y) DPRINTF(CGDB_FOLLOW, y)
126
127 static void hexprint(char *, void *, int);
128
129 #else
130 #define IFDEBUG(x,y)
131 #define DPRINTF(x,y)
132 #define DPRINTF_FOLLOW(y)
133 #endif
134
135 #ifdef DIAGNOSTIC
136 #define DIAGPANIC(x) panic x
137 #define DIAGCONDPANIC(x,y) if (x) panic y
138 #else
139 #define DIAGPANIC(x)
140 #define DIAGCONDPANIC(x,y)
141 #endif
142
143 /* Global variables */
144
145 struct cgd_softc *cgd_softc;
146 int numcgd = 0;
147
148 /* Utility Functions */
149
150 #define CGDUNIT(x) DISKUNIT(x)
151 #define GETCGD_SOFTC(_cs, x) if (!((_cs) = getcgd_softc(x))) return ENXIO
152
153 static struct cgd_softc *
154 getcgd_softc(dev_t dev)
155 {
156 int unit = CGDUNIT(dev);
157
158 DPRINTF_FOLLOW(("getcgd_softc(0x%x): unit = %d\n", dev, unit));
159 if (unit >= numcgd)
160 return NULL;
161 return &cgd_softc[unit];
162 }
163
164 /* The code */
165
166 static void
167 cgdsoftc_init(struct cgd_softc *cs, int num)
168 {
169 char buf[DK_XNAME_SIZE];
170
171 memset(cs, 0x0, sizeof(*cs));
172 snprintf(buf, DK_XNAME_SIZE, "cgd%d", num);
173 simple_lock_init(&cs->sc_slock);
174 dk_sc_init(&cs->sc_dksc, cs, buf);
175 }
176
177 void
178 cgdattach(int num)
179 {
180 int i;
181
182 DPRINTF_FOLLOW(("cgdattach(%d)\n", num));
183 if (num <= 0) {
184 DIAGPANIC(("cgdattach: count <= 0"));
185 return;
186 }
187
188 cgd_softc = (void *)malloc(num * sizeof(*cgd_softc), M_DEVBUF, M_NOWAIT);
189 if (!cgd_softc) {
190 printf("WARNING: unable to malloc(9) memory for crypt disks\n");
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 proc *p)
202 {
203 struct cgd_softc *cs;
204
205 DPRINTF_FOLLOW(("cgdopen(%d, %d)\n", dev, flags));
206 GETCGD_SOFTC(cs, dev);
207 return dk_open(di, &cs->sc_dksc, dev, flags, fmt, p);
208 }
209
210 static int
211 cgdclose(dev_t dev, int flags, int fmt, struct proc *p)
212 {
213 struct cgd_softc *cs;
214
215 DPRINTF_FOLLOW(("cgdclose(%d, %d)\n", dev, flags));
216 GETCGD_SOFTC(cs, dev);
217 return dk_close(di, &cs->sc_dksc, dev, flags, fmt, p);
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(%d)\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 caddr_t 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, caddr_t 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 struct partition *pp;
290 caddr_t addr;
291 caddr_t newaddr;
292 daddr_t bn;
293 int s;
294
295 DPRINTF_FOLLOW(("cgdstart(%p, %p)\n", dksc, bp));
296 disk_busy(&dksc->sc_dkdev); /* XXX: put in dksubr.c */
297
298 /* XXXrcd:
299 * Translate partition relative blocks to absolute blocks,
300 * this probably belongs (somehow) in dksubr.c, since it
301 * is independant of the underlying code... This will require
302 * that the interface be expanded slightly, though.
303 */
304 bn = bp->b_blkno;
305 if (DISKPART(bp->b_dev) != RAW_PART) {
306 pp = &cs->sc_dksc.sc_dkdev.dk_label->d_partitions[DISKPART(bp->b_dev)];
307 bn += pp->p_offset;
308 }
309
310 /*
311 * We attempt to allocate all of our resources up front, so that
312 * we can fail quickly if they are unavailable.
313 */
314
315 s = splbio();
316 nbp = pool_get(&bufpool, PR_NOWAIT);
317 splx(s);
318 if (nbp == NULL) {
319 disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ));
320 return -1;
321 }
322
323 /*
324 * If we are writing, then we need to encrypt the outgoing
325 * block into a new block of memory. If we fail, then we
326 * return an error and let the dksubr framework deal with it.
327 */
328 newaddr = addr = bp->b_data;
329 if ((bp->b_flags & B_READ) == 0) {
330 newaddr = cgd_getdata(dksc, bp->b_bcount);
331 if (!newaddr) {
332 s = splbio();
333 pool_put(&bufpool, nbp);
334 splx(s);
335 disk_unbusy(&dksc->sc_dkdev, 0, (bp->b_flags & B_READ));
336 return -1;
337 }
338 cgd_cipher(cs, newaddr, addr, bp->b_bcount, bn,
339 DEV_BSIZE, CGD_CIPHER_ENCRYPT);
340 }
341
342 BUF_INIT(nbp);
343 nbp->b_data = newaddr;
344 nbp->b_flags = bp->b_flags | B_CALL;
345 nbp->b_iodone = cgdiodone;
346 nbp->b_proc = bp->b_proc;
347 nbp->b_blkno = bn;
348 nbp->b_vp = cs->sc_tvn;
349 nbp->b_bcount = bp->b_bcount;
350 nbp->b_private = bp;
351
352 BIO_COPYPRIO(nbp, bp);
353
354 if ((nbp->b_flags & B_READ) == 0) {
355 V_INCR_NUMOUTPUT(nbp->b_vp);
356 }
357 VOP_STRATEGY(cs->sc_tvn, nbp);
358 return 0;
359 }
360
361 /* expected to be called at splbio() */
362 static void
363 cgdiodone(struct buf *nbp)
364 {
365 struct buf *obp = nbp->b_private;
366 struct cgd_softc *cs = getcgd_softc(obp->b_dev);
367 struct dk_softc *dksc = &cs->sc_dksc;
368
369 KDASSERT(cs);
370
371 DPRINTF_FOLLOW(("cgdiodone(%p)\n", nbp));
372 DPRINTF(CGDB_IO, ("cgdiodone: bp %p bcount %d resid %d\n",
373 obp, obp->b_bcount, obp->b_resid));
374 DPRINTF(CGDB_IO, (" dev 0x%x, nbp %p bn %" PRId64 " addr %p bcnt %d\n",
375 nbp->b_dev, nbp, nbp->b_blkno, nbp->b_data,
376 nbp->b_bcount));
377 if (nbp->b_flags & B_ERROR) {
378 obp->b_flags |= B_ERROR;
379 obp->b_error = nbp->b_error ? nbp->b_error : EIO;
380
381 printf("%s: error %d\n", dksc->sc_xname, obp->b_error);
382 }
383
384 /* Perform the decryption if we are reading.
385 *
386 * Note: use the blocknumber from nbp, since it is what
387 * we used to encrypt the blocks.
388 */
389
390 if (nbp->b_flags & B_READ)
391 cgd_cipher(cs, obp->b_data, obp->b_data, obp->b_bcount,
392 nbp->b_blkno, DEV_BSIZE, CGD_CIPHER_DECRYPT);
393
394 /* If we allocated memory, free it now... */
395 if (nbp->b_data != obp->b_data)
396 cgd_putdata(dksc, nbp->b_data);
397
398 pool_put(&bufpool, nbp);
399
400 /* Request is complete for whatever reason */
401 obp->b_resid = 0;
402 if (obp->b_flags & B_ERROR)
403 obp->b_resid = obp->b_bcount;
404 disk_unbusy(&dksc->sc_dkdev, obp->b_bcount - obp->b_resid,
405 (obp->b_flags & B_READ));
406 biodone(obp);
407 dk_iodone(di, dksc);
408 }
409
410 /* XXX: we should probably put these into dksubr.c, mostly */
411 static int
412 cgdread(dev_t dev, struct uio *uio, int flags)
413 {
414 struct cgd_softc *cs;
415 struct dk_softc *dksc;
416
417 DPRINTF_FOLLOW(("cgdread(%d, %p, %d)\n", dev, uio, flags));
418 GETCGD_SOFTC(cs, dev);
419 dksc = &cs->sc_dksc;
420 if ((dksc->sc_flags & DKF_INITED) == 0)
421 return ENXIO;
422 return physio(cgdstrategy, NULL, dev, B_READ, minphys, uio);
423 }
424
425 /* XXX: we should probably put these into dksubr.c, mostly */
426 static int
427 cgdwrite(dev_t dev, struct uio *uio, int flags)
428 {
429 struct cgd_softc *cs;
430 struct dk_softc *dksc;
431
432 DPRINTF_FOLLOW(("cgdwrite(%d, %p, %d)\n", dev, uio, flags));
433 GETCGD_SOFTC(cs, dev);
434 dksc = &cs->sc_dksc;
435 if ((dksc->sc_flags & DKF_INITED) == 0)
436 return ENXIO;
437 return physio(cgdstrategy, NULL, dev, B_WRITE, minphys, uio);
438 }
439
440 static int
441 cgdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
442 {
443 struct cgd_softc *cs;
444 struct dk_softc *dksc;
445 int ret;
446 int part = DISKPART(dev);
447 int pmask = 1 << part;
448
449 DPRINTF_FOLLOW(("cgdioctl(%d, %ld, %p, %d, %p)\n",
450 dev, cmd, data, flag, p));
451 GETCGD_SOFTC(cs, dev);
452 dksc = &cs->sc_dksc;
453 switch (cmd) {
454 case CGDIOCSET:
455 case CGDIOCCLR:
456 if ((flag & FWRITE) == 0)
457 return EBADF;
458 }
459
460 if ((ret = lockmgr(&dksc->sc_lock, LK_EXCLUSIVE, NULL)) != 0)
461 return ret;
462
463 switch (cmd) {
464 case CGDIOCSET:
465 if (dksc->sc_flags & DKF_INITED)
466 ret = EBUSY;
467 else
468 ret = cgd_ioctl_set(cs, data, p);
469 break;
470 case CGDIOCCLR:
471 if (!(dksc->sc_flags & DKF_INITED)) {
472 ret = ENXIO;
473 break;
474 }
475 if (DK_BUSY(&cs->sc_dksc, pmask)) {
476 ret = EBUSY;
477 break;
478 }
479 ret = cgd_ioctl_clr(cs, data, p);
480 break;
481 default:
482 ret = dk_ioctl(di, dksc, dev, cmd, data, flag, p);
483 break;
484 }
485
486 lockmgr(&dksc->sc_lock, LK_RELEASE, NULL);
487 return ret;
488 }
489
490 static int
491 cgddump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
492 {
493 struct cgd_softc *cs;
494
495 DPRINTF_FOLLOW(("cgddump(%d, %" PRId64 ", %p, %lu)\n", dev, blkno, va,
496 (unsigned long)size));
497 GETCGD_SOFTC(cs, dev);
498 return dk_dump(di, &cs->sc_dksc, dev, blkno, va, size);
499 }
500
501 /*
502 * XXXrcd:
503 * for now we hardcode the maximum key length.
504 */
505 #define MAX_KEYSIZE 1024
506
507 /* ARGSUSED */
508 static int
509 cgd_ioctl_set(struct cgd_softc *cs, void *data, struct proc *p)
510 {
511 struct cgd_ioctl *ci = data;
512 struct vnode *vp;
513 int ret;
514 int keybytes; /* key length in bytes */
515 char *cp;
516 char inbuf[MAX_KEYSIZE];
517
518 cp = ci->ci_disk;
519 if ((ret = dk_lookup(cp, p, &vp)) != 0)
520 return ret;
521
522 if ((ret = cgdinit(cs, cp, vp, p)) != 0)
523 goto bail;
524
525 memset(inbuf, 0x0, sizeof(inbuf));
526 ret = copyinstr(ci->ci_alg, inbuf, 256, NULL);
527 if (ret)
528 goto bail;
529 cs->sc_cfuncs = cryptfuncs_find(inbuf);
530 if (!cs->sc_cfuncs) {
531 ret = EINVAL;
532 goto bail;
533 }
534
535 /* right now we only support encblkno, so hard-code it */
536 memset(inbuf, 0x0, sizeof(inbuf));
537 ret = copyinstr(ci->ci_ivmethod, inbuf, sizeof(inbuf), NULL);
538 if (ret)
539 goto bail;
540 if (strcmp("encblkno", inbuf)) {
541 ret = EINVAL;
542 goto bail;
543 }
544
545 keybytes = ci->ci_keylen / 8 + 1;
546 if (keybytes > MAX_KEYSIZE) {
547 ret = EINVAL;
548 goto bail;
549 }
550 memset(inbuf, 0x0, sizeof(inbuf));
551 ret = copyin(ci->ci_key, inbuf, keybytes);
552 if (ret)
553 goto bail;
554
555 cs->sc_cdata.cf_blocksize = ci->ci_blocksize;
556 cs->sc_cdata.cf_mode = CGD_CIPHER_CBC_ENCBLKNO;
557 cs->sc_cdata.cf_priv = cs->sc_cfuncs->cf_init(ci->ci_keylen, inbuf,
558 &cs->sc_cdata.cf_blocksize);
559 memset(inbuf, 0x0, sizeof(inbuf));
560 if (!cs->sc_cdata.cf_priv) {
561 printf("cgd: unable to initialize cipher\n");
562 ret = EINVAL; /* XXX is this the right error? */
563 goto bail;
564 }
565
566 bufq_alloc(&cs->sc_dksc.sc_bufq, BUFQ_FCFS);
567
568 cs->sc_data = malloc(MAXPHYS, M_DEVBUF, M_WAITOK);
569 cs->sc_data_used = 0;
570
571 cs->sc_dksc.sc_flags |= DKF_INITED;
572
573 /* Attach the disk. */
574 disk_attach(&cs->sc_dksc.sc_dkdev);
575
576 /* Try and read the disklabel. */
577 dk_getdisklabel(di, &cs->sc_dksc, 0 /* XXX ? */);
578
579 return 0;
580
581 bail:
582 (void)vn_close(vp, FREAD|FWRITE, p->p_ucred, p);
583 return ret;
584 }
585
586 /* ARGSUSED */
587 static int
588 cgd_ioctl_clr(struct cgd_softc *cs, void *data, struct proc *p)
589 {
590 int s;
591
592 /* Kill off any queued buffers. */
593 s = splbio();
594 bufq_drain(&cs->sc_dksc.sc_bufq);
595 splx(s);
596 bufq_free(&cs->sc_dksc.sc_bufq);
597
598 (void)vn_close(cs->sc_tvn, FREAD|FWRITE, p->p_ucred, p);
599 cs->sc_cfuncs->cf_destroy(cs->sc_cdata.cf_priv);
600 free(cs->sc_tpath, M_DEVBUF);
601 free(cs->sc_data, M_DEVBUF);
602 cs->sc_data_used = 0;
603 cs->sc_dksc.sc_flags &= ~DKF_INITED;
604 disk_detach(&cs->sc_dksc.sc_dkdev);
605
606 return 0;
607 }
608
609 static int
610 cgdinit(struct cgd_softc *cs, char *cpath, struct vnode *vp,
611 struct proc *p)
612 {
613 struct dk_geom *pdg;
614 struct partinfo dpart;
615 struct vattr va;
616 size_t size;
617 int maxsecsize = 0;
618 int ret;
619 char tmppath[MAXPATHLEN];
620
621 cs->sc_dksc.sc_size = 0;
622 cs->sc_tvn = vp;
623
624 memset(tmppath, 0x0, sizeof(tmppath));
625 ret = copyinstr(cpath, tmppath, MAXPATHLEN, &cs->sc_tpathlen);
626 if (ret)
627 goto bail;
628 cs->sc_tpath = malloc(cs->sc_tpathlen, M_DEVBUF, M_WAITOK);
629 memcpy(cs->sc_tpath, tmppath, cs->sc_tpathlen);
630
631 if ((ret = VOP_GETATTR(vp, &va, p->p_ucred, p)) != 0)
632 goto bail;
633
634 cs->sc_tdev = va.va_rdev;
635
636 ret = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, p->p_ucred, p);
637 if (ret)
638 goto bail;
639
640 maxsecsize =
641 ((dpart.disklab->d_secsize > maxsecsize) ?
642 dpart.disklab->d_secsize : maxsecsize);
643 size = dpart.part->p_size;
644
645 if (!size) {
646 ret = ENODEV;
647 goto bail;
648 }
649
650 cs->sc_dksc.sc_size = size;
651
652 /*
653 * XXX here we should probe the underlying device. If we
654 * are accessing a partition of type RAW_PART, then
655 * we should populate our initial geometry with the
656 * geometry that we discover from the device.
657 */
658 pdg = &cs->sc_dksc.sc_geom;
659 pdg->pdg_secsize = DEV_BSIZE;
660 pdg->pdg_ntracks = 1;
661 pdg->pdg_nsectors = 1024 * (1024 / pdg->pdg_secsize);
662 pdg->pdg_ncylinders = cs->sc_dksc.sc_size / pdg->pdg_nsectors;
663
664 bail:
665 if (ret && cs->sc_tpath)
666 free(cs->sc_tpath, M_DEVBUF);
667 return ret;
668 }
669
670 /*
671 * Our generic cipher entry point. This takes care of the
672 * IV mode and passes off the work to the specific cipher.
673 * We implement here the IV method ``encrypted block
674 * number''.
675 *
676 * For the encryption case, we accomplish this by setting
677 * up a struct uio where the first iovec of the source is
678 * the blocknumber and the first iovec of the dest is a
679 * sink. We then call the cipher with an IV of zero, and
680 * the right thing happens.
681 *
682 * For the decryption case, we use the same basic mechanism
683 * for symmetry, but we encrypt the block number in the
684 * first iovec.
685 *
686 * We mainly do this to avoid requiring the definition of
687 * an ECB mode.
688 *
689 * XXXrcd: for now we rely on our own crypto framework defined
690 * in dev/cgd_crypto.c. This will change when we
691 * get a generic kernel crypto framework.
692 */
693
694 static void
695 blkno2blkno_buf(char *buf, daddr_t blkno)
696 {
697 int i;
698
699 /* Set up the blkno in blkno_buf, here we do not care much
700 * about the final layout of the information as long as we
701 * can guarantee that each sector will have a different IV
702 * and that the endianness of the machine will not affect
703 * the representation that we have chosen.
704 *
705 * We choose this representation, because it does not rely
706 * on the size of buf (which is the blocksize of the cipher),
707 * but allows daddr_t to grow without breaking existing
708 * disks.
709 *
710 * Note that blkno2blkno_buf does not take a size as input,
711 * and hence must be called on a pre-zeroed buffer of length
712 * greater than or equal to sizeof(daddr_t).
713 */
714 for (i=0; i < sizeof(daddr_t); i++) {
715 *buf++ = blkno & 0xff;
716 blkno >>= 8;
717 }
718 }
719
720 static void
721 cgd_cipher(struct cgd_softc *cs, caddr_t dst, caddr_t src,
722 size_t len, daddr_t blkno, size_t secsize, int dir)
723 {
724 cfunc_cipher *cipher = cs->sc_cfuncs->cf_cipher;
725 struct uio dstuio;
726 struct uio srcuio;
727 struct iovec dstiov[2];
728 struct iovec srciov[2];
729 int blocksize = cs->sc_cdata.cf_blocksize;
730 char sink[blocksize];
731 char zero_iv[blocksize];
732 char blkno_buf[blocksize];
733
734 DPRINTF_FOLLOW(("cgd_cipher() dir=%d\n", dir));
735
736 DIAGCONDPANIC(len % blocksize != 0,
737 ("cgd_cipher: len %% blocksize != 0"));
738
739 /* ensure that sizeof(daddr_t) <= blocksize (for encblkno IVing) */
740 DIAGCONDPANIC(sizeof(daddr_t) > blocksize,
741 ("cgd_cipher: sizeof(daddr_t) > blocksize"));
742
743 memset(zero_iv, 0x0, sizeof(zero_iv));
744
745 dstuio.uio_iov = dstiov;
746 dstuio.uio_iovcnt = 2;
747
748 srcuio.uio_iov = srciov;
749 srcuio.uio_iovcnt = 2;
750
751 dstiov[0].iov_base = sink;
752 dstiov[0].iov_len = blocksize;
753 srciov[0].iov_base = blkno_buf;
754 srciov[0].iov_len = blocksize;
755 dstiov[1].iov_len = secsize;
756 srciov[1].iov_len = secsize;
757
758 for (; len > 0; len -= secsize) {
759 dstiov[1].iov_base = dst;
760 srciov[1].iov_base = src;
761
762 memset(blkno_buf, 0x0, sizeof(blkno_buf));
763 blkno2blkno_buf(blkno_buf, blkno);
764 if (dir == CGD_CIPHER_DECRYPT) {
765 dstuio.uio_iovcnt = 1;
766 srcuio.uio_iovcnt = 1;
767 IFDEBUG(CGDB_CRYPTO, hexprint("step 0: blkno_buf",
768 blkno_buf, sizeof(blkno_buf)));
769 cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio,
770 zero_iv, CGD_CIPHER_ENCRYPT);
771 memcpy(blkno_buf, sink, blocksize);
772 dstuio.uio_iovcnt = 2;
773 srcuio.uio_iovcnt = 2;
774 }
775
776 IFDEBUG(CGDB_CRYPTO, hexprint("step 1: blkno_buf",
777 blkno_buf, sizeof(blkno_buf)));
778 cipher(cs->sc_cdata.cf_priv, &dstuio, &srcuio, zero_iv, dir);
779 IFDEBUG(CGDB_CRYPTO, hexprint("step 2: sink",
780 sink, sizeof(sink)));
781
782 dst += secsize;
783 src += secsize;
784 blkno++;
785 }
786 }
787
788 #ifdef DEBUG
789 static void
790 hexprint(char *start, void *buf, int len)
791 {
792 char *c = buf;
793
794 DIAGCONDPANIC(len < 0, ("hexprint: called with len < 0"));
795 printf("%s: len=%06d 0x", start, len);
796 while (len--)
797 printf("%02x", (unsigned) *c++);
798 }
799 #endif
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