g_eli_privacy.c revision 213063
1/*-
2 * Copyright (c) 2005-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/geom/eli/g_eli_privacy.c 213063 2010-09-23 11:23:10Z pjd $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/linker.h>
34#include <sys/module.h>
35#include <sys/lock.h>
36#include <sys/mutex.h>
37#include <sys/bio.h>
38#include <sys/sysctl.h>
39#include <sys/malloc.h>
40#include <sys/kthread.h>
41#include <sys/proc.h>
42#include <sys/sched.h>
43#include <sys/smp.h>
44#include <sys/uio.h>
45#include <sys/vnode.h>
46
47#include <vm/uma.h>
48
49#include <geom/geom.h>
50#include <geom/eli/g_eli.h>
51#include <geom/eli/pkcs5v2.h>
52
53/*
54 * Code paths:
55 * BIO_READ:
56 *	g_eli_start -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
57 * BIO_WRITE:
58 *	g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
59 */
60
61MALLOC_DECLARE(M_ELI);
62
63/*
64 * The function is called after we read and decrypt data.
65 *
66 * g_eli_start -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> G_ELI_CRYPTO_READ_DONE -> g_io_deliver
67 */
68static int
69g_eli_crypto_read_done(struct cryptop *crp)
70{
71	struct bio *bp;
72
73	if (crp->crp_etype == EAGAIN) {
74		if (g_eli_crypto_rerun(crp) == 0)
75			return (0);
76	}
77	bp = (struct bio *)crp->crp_opaque;
78	bp->bio_inbed++;
79	if (crp->crp_etype == 0) {
80		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
81		    bp->bio_inbed, bp->bio_children);
82		bp->bio_completed += crp->crp_olen;
83	} else {
84		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
85		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
86		if (bp->bio_error == 0)
87			bp->bio_error = crp->crp_etype;
88	}
89	/*
90	 * Do we have all sectors already?
91	 */
92	if (bp->bio_inbed < bp->bio_children)
93		return (0);
94	free(bp->bio_driver2, M_ELI);
95	bp->bio_driver2 = NULL;
96	if (bp->bio_error != 0) {
97		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
98		    bp->bio_error);
99		bp->bio_completed = 0;
100	}
101	/*
102	 * Read is finished, send it up.
103	 */
104	g_io_deliver(bp, bp->bio_error);
105	return (0);
106}
107
108/*
109 * The function is called after data encryption.
110 *
111 * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
112 */
113static int
114g_eli_crypto_write_done(struct cryptop *crp)
115{
116	struct g_geom *gp;
117	struct g_consumer *cp;
118	struct bio *bp, *cbp;
119
120	if (crp->crp_etype == EAGAIN) {
121		if (g_eli_crypto_rerun(crp) == 0)
122			return (0);
123	}
124	bp = (struct bio *)crp->crp_opaque;
125	bp->bio_inbed++;
126	if (crp->crp_etype == 0) {
127		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
128		    bp->bio_inbed, bp->bio_children);
129	} else {
130		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
131		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
132		if (bp->bio_error == 0)
133			bp->bio_error = crp->crp_etype;
134	}
135	/*
136	 * All sectors are already encrypted?
137	 */
138	if (bp->bio_inbed < bp->bio_children)
139		return (0);
140	bp->bio_inbed = 0;
141	bp->bio_children = 1;
142	cbp = bp->bio_driver1;
143	bp->bio_driver1 = NULL;
144	if (bp->bio_error != 0) {
145		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
146		    bp->bio_error);
147		free(bp->bio_driver2, M_ELI);
148		bp->bio_driver2 = NULL;
149		g_destroy_bio(cbp);
150		g_io_deliver(bp, bp->bio_error);
151		return (0);
152	}
153	cbp->bio_data = bp->bio_driver2;
154	cbp->bio_done = g_eli_write_done;
155	gp = bp->bio_to->geom;
156	cp = LIST_FIRST(&gp->consumer);
157	cbp->bio_to = cp->provider;
158	G_ELI_LOGREQ(2, cbp, "Sending request.");
159	/*
160	 * Send encrypted data to the provider.
161	 */
162	g_io_request(cbp, cp);
163	return (0);
164}
165
166/*
167 * This is the main function responsible for cryptography (ie. communication
168 * with crypto(9) subsystem).
169 */
170void
171g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
172{
173	struct g_eli_softc *sc;
174	struct cryptop *crp;
175	struct cryptodesc *crd;
176	struct uio *uio;
177	struct iovec *iov;
178	u_int i, nsec, secsize;
179	int err, error;
180	off_t dstoff;
181	size_t size;
182	u_char *p, *data;
183
184	G_ELI_LOGREQ(3, bp, "%s", __func__);
185
186	bp->bio_pflags = wr->w_number;
187	sc = wr->w_softc;
188	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
189	nsec = bp->bio_length / secsize;
190
191	/*
192	 * Calculate how much memory do we need.
193	 * We need separate crypto operation for every single sector.
194	 * It is much faster to calculate total amount of needed memory here and
195	 * do the allocation once instead of allocating memory in pieces (many,
196	 * many pieces).
197	 */
198	size = sizeof(*crp) * nsec;
199	size += sizeof(*crd) * nsec;
200	size += sizeof(*uio) * nsec;
201	size += sizeof(*iov) * nsec;
202	/*
203	 * If we write the data we cannot destroy current bio_data content,
204	 * so we need to allocate more memory for encrypted data.
205	 */
206	if (bp->bio_cmd == BIO_WRITE)
207		size += bp->bio_length;
208	p = malloc(size, M_ELI, M_WAITOK);
209
210	bp->bio_inbed = 0;
211	bp->bio_children = nsec;
212	bp->bio_driver2 = p;
213
214	if (bp->bio_cmd == BIO_READ)
215		data = bp->bio_data;
216	else {
217		data = p;
218		p += bp->bio_length;
219		bcopy(bp->bio_data, data, bp->bio_length);
220	}
221
222	error = 0;
223	for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
224		crp = (struct cryptop *)p;	p += sizeof(*crp);
225		crd = (struct cryptodesc *)p;	p += sizeof(*crd);
226		uio = (struct uio *)p;		p += sizeof(*uio);
227		iov = (struct iovec *)p;	p += sizeof(*iov);
228
229		iov->iov_len = secsize;
230		iov->iov_base = data;
231		data += secsize;
232
233		uio->uio_iov = iov;
234		uio->uio_iovcnt = 1;
235		uio->uio_segflg = UIO_SYSSPACE;
236		uio->uio_resid = secsize;
237
238		crp->crp_sid = wr->w_sid;
239		crp->crp_ilen = secsize;
240		crp->crp_olen = secsize;
241		crp->crp_opaque = (void *)bp;
242		crp->crp_buf = (void *)uio;
243		if (bp->bio_cmd == BIO_WRITE)
244			crp->crp_callback = g_eli_crypto_write_done;
245		else /* if (bp->bio_cmd == BIO_READ) */
246			crp->crp_callback = g_eli_crypto_read_done;
247		crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_CBIFSYNC | CRYPTO_F_REL;
248		if (g_eli_batch)
249			crp->crp_flags |= CRYPTO_F_BATCH;
250		crp->crp_desc = crd;
251
252		crd->crd_skip = 0;
253		crd->crd_len = secsize;
254		crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
255		if (bp->bio_cmd == BIO_WRITE)
256			crd->crd_flags |= CRD_F_ENCRYPT;
257		crd->crd_alg = sc->sc_ealgo;
258		crd->crd_key = sc->sc_ekey;
259		crd->crd_klen = sc->sc_ekeylen;
260		g_eli_crypto_ivgen(sc, dstoff, crd->crd_iv,
261		    sizeof(crd->crd_iv));
262		crd->crd_next = NULL;
263
264		crp->crp_etype = 0;
265		err = crypto_dispatch(crp);
266		if (error == 0)
267			error = err;
268	}
269	if (bp->bio_error == 0)
270		bp->bio_error = error;
271}
272