g_bde.c revision 314327
1/*-
2 * Copyright (c) 2002 Poul-Henning Kamp
3 * Copyright (c) 2002 Networks Associates Technology, Inc.
4 * All rights reserved.
5 *
6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7 * and NAI Labs, the Security Research Division of Network Associates, Inc.
8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9 * DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: stable/10/sys/geom/bde/g_bde.c 314327 2017-02-27 08:27:38Z avg $
33 *
34 */
35
36#include <sys/param.h>
37#include <sys/bio.h>
38#include <sys/lock.h>
39#include <sys/mutex.h>
40#include <sys/malloc.h>
41#include <sys/systm.h>
42#include <sys/kernel.h>
43#include <sys/kthread.h>
44#include <sys/sysctl.h>
45
46#include <crypto/rijndael/rijndael-api-fst.h>
47#include <crypto/sha2/sha512.h>
48#include <geom/geom.h>
49#include <geom/bde/g_bde.h>
50#define BDE_CLASS_NAME "BDE"
51
52FEATURE(geom_bde, "GEOM-based Disk Encryption");
53
54static void
55g_bde_start(struct bio *bp)
56{
57
58	switch (bp->bio_cmd) {
59	case BIO_DELETE:
60	case BIO_READ:
61	case BIO_WRITE:
62		g_bde_start1(bp);
63		break;
64	case BIO_GETATTR:
65		g_io_deliver(bp, EOPNOTSUPP);
66		break;
67	default:
68		g_io_deliver(bp, EOPNOTSUPP);
69		return;
70	}
71	return;
72}
73
74static void
75g_bde_orphan(struct g_consumer *cp)
76{
77	struct g_geom *gp;
78	struct g_provider *pp;
79	struct g_bde_softc *sc;
80
81	g_trace(G_T_TOPOLOGY, "g_bde_orphan(%p/%s)", cp, cp->provider->name);
82	g_topology_assert();
83
84	gp = cp->geom;
85	sc = gp->softc;
86	gp->flags |= G_GEOM_WITHER;
87	LIST_FOREACH(pp, &gp->provider, provider)
88		g_wither_provider(pp, ENXIO);
89	bzero(sc, sizeof(struct g_bde_softc));	/* destroy evidence */
90	return;
91}
92
93static int
94g_bde_access(struct g_provider *pp, int dr, int dw, int de)
95{
96	struct g_geom *gp;
97	struct g_consumer *cp;
98
99	gp = pp->geom;
100	cp = LIST_FIRST(&gp->consumer);
101	if (cp->acr == 0 && cp->acw == 0 && cp->ace == 0) {
102		de++;
103		dr++;
104	}
105	/* ... and let go of it on last close */
106	if ((cp->acr + dr) == 0 && (cp->acw + dw) == 0 && (cp->ace + de) == 1) {
107		de--;
108		dr--;
109	}
110	return (g_access(cp, dr, dw, de));
111}
112
113static void
114g_bde_create_geom(struct gctl_req *req, struct g_class *mp, struct g_provider *pp)
115{
116	struct g_geom *gp;
117	struct g_consumer *cp;
118	struct g_bde_key *kp;
119	int error, i;
120	u_int sectorsize;
121	off_t mediasize;
122	struct g_bde_softc *sc;
123	void *pass;
124	void *key;
125
126	g_trace(G_T_TOPOLOGY, "g_bde_create_geom(%s, %s)", mp->name, pp->name);
127	g_topology_assert();
128	gp = NULL;
129
130
131	gp = g_new_geomf(mp, "%s.bde", pp->name);
132	cp = g_new_consumer(gp);
133	g_attach(cp, pp);
134	error = g_access(cp, 1, 1, 1);
135	if (error) {
136		g_detach(cp);
137		g_destroy_consumer(cp);
138		g_destroy_geom(gp);
139		gctl_error(req, "could not access consumer");
140		return;
141	}
142	pass = NULL;
143	key = NULL;
144	do {
145		pass = gctl_get_param(req, "pass", &i);
146		if (pass == NULL || i != SHA512_DIGEST_LENGTH) {
147			gctl_error(req, "No usable key presented");
148			break;
149		}
150		key = gctl_get_param(req, "key", &i);
151		if (key != NULL && i != 16) {
152			gctl_error(req, "Invalid key presented");
153			break;
154		}
155		sectorsize = cp->provider->sectorsize;
156		mediasize = cp->provider->mediasize;
157		sc = g_malloc(sizeof(struct g_bde_softc), M_WAITOK | M_ZERO);
158		gp->softc = sc;
159		sc->geom = gp;
160		sc->consumer = cp;
161
162		error = g_bde_decrypt_lock(sc, pass, key,
163		    mediasize, sectorsize, NULL);
164		bzero(sc->sha2, sizeof sc->sha2);
165		if (error)
166			break;
167		kp = &sc->key;
168
169		/* Initialize helper-fields */
170		kp->keys_per_sector = kp->sectorsize / G_BDE_SKEYLEN;
171		kp->zone_cont = kp->keys_per_sector * kp->sectorsize;
172		kp->zone_width = kp->zone_cont + kp->sectorsize;
173		kp->media_width = kp->sectorN - kp->sector0 -
174		    G_BDE_MAXKEYS * kp->sectorsize;
175
176		/* Our external parameters */
177		sc->zone_cont = kp->zone_cont;
178		sc->mediasize = g_bde_max_sector(kp);
179		sc->sectorsize = kp->sectorsize;
180
181		TAILQ_INIT(&sc->freelist);
182		TAILQ_INIT(&sc->worklist);
183		mtx_init(&sc->worklist_mutex, "g_bde_worklist", NULL, MTX_DEF);
184		/* XXX: error check */
185		kproc_create(g_bde_worker, gp, &sc->thread, 0, 0,
186			"g_bde %s", gp->name);
187		pp = g_new_providerf(gp, "%s", gp->name);
188		pp->stripesize = kp->zone_cont;
189		pp->stripeoffset = 0;
190		pp->mediasize = sc->mediasize;
191		pp->sectorsize = sc->sectorsize;
192		g_error_provider(pp, 0);
193		break;
194	} while (0);
195	if (pass != NULL)
196		bzero(pass, SHA512_DIGEST_LENGTH);
197	if (key != NULL)
198		bzero(key, 16);
199	if (error == 0)
200		return;
201	g_access(cp, -1, -1, -1);
202	g_detach(cp);
203	g_destroy_consumer(cp);
204	if (gp->softc != NULL)
205		g_free(gp->softc);
206	g_destroy_geom(gp);
207	return;
208}
209
210
211static int
212g_bde_destroy_geom(struct gctl_req *req, struct g_class *mp, struct g_geom *gp)
213{
214	struct g_consumer *cp;
215	struct g_provider *pp;
216	struct g_bde_softc *sc;
217
218	g_trace(G_T_TOPOLOGY, "g_bde_destroy_geom(%s, %s)", mp->name, gp->name);
219	g_topology_assert();
220	/*
221	 * Orderly detachment.
222	 */
223	KASSERT(gp != NULL, ("NULL geom"));
224	pp = LIST_FIRST(&gp->provider);
225	KASSERT(pp != NULL, ("NULL provider"));
226	if (pp->acr > 0 || pp->acw > 0 || pp->ace > 0)
227		return (EBUSY);
228	sc = gp->softc;
229	cp = LIST_FIRST(&gp->consumer);
230	KASSERT(cp != NULL, ("NULL consumer"));
231	sc->dead = 1;
232	wakeup(sc);
233	g_access(cp, -1, -1, -1);
234	g_detach(cp);
235	g_destroy_consumer(cp);
236	while (sc->dead != 2 && !LIST_EMPTY(&pp->consumers))
237		tsleep(sc, PRIBIO, "g_bdedie", hz);
238	mtx_destroy(&sc->worklist_mutex);
239	bzero(&sc->key, sizeof sc->key);
240	g_free(sc);
241	g_wither_geom(gp, ENXIO);
242	return (0);
243}
244
245static void
246g_bde_ctlreq(struct gctl_req *req, struct g_class *mp, char const *verb)
247{
248	struct g_geom *gp;
249	struct g_provider *pp;
250
251	if (!strcmp(verb, "create geom")) {
252		pp = gctl_get_provider(req, "provider");
253		if (pp != NULL)
254			g_bde_create_geom(req, mp, pp);
255	} else if (!strcmp(verb, "destroy geom")) {
256		gp = gctl_get_geom(req, mp, "geom");
257		if (gp != NULL)
258			g_bde_destroy_geom(req, mp, gp);
259	} else {
260		gctl_error(req, "unknown verb");
261	}
262}
263
264static struct g_class g_bde_class	= {
265	.name = BDE_CLASS_NAME,
266	.version = G_VERSION,
267	.destroy_geom = g_bde_destroy_geom,
268	.ctlreq = g_bde_ctlreq,
269	.start = g_bde_start,
270	.orphan = g_bde_orphan,
271	.access = g_bde_access,
272	.spoiled = g_std_spoiled,
273};
274
275DECLARE_GEOM_CLASS(g_bde_class, g_bde);
276