xref: /freebsd/sys/geom/eli/g_eli_privacy.c (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/linker.h>
36 #include <sys/module.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/bio.h>
40 #include <sys/sysctl.h>
41 #include <sys/malloc.h>
42 #include <sys/kthread.h>
43 #include <sys/proc.h>
44 #include <sys/sched.h>
45 #include <sys/smp.h>
46 #include <sys/vnode.h>
47 
48 #include <vm/uma.h>
49 
50 #include <geom/geom.h>
51 #include <geom/eli/g_eli.h>
52 #include <geom/eli/pkcs5v2.h>
53 
54 /*
55  * Code paths:
56  * BIO_READ:
57  *	g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
58  * BIO_WRITE:
59  *	g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
60  */
61 
62 MALLOC_DECLARE(M_ELI);
63 
64 /*
65  * The function is called after we read and decrypt data.
66  *
67  * g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> G_ELI_CRYPTO_READ_DONE -> g_io_deliver
68  */
69 static int
70 g_eli_crypto_read_done(struct cryptop *crp)
71 {
72 	struct g_eli_softc *sc;
73 	struct bio *bp;
74 
75 	if (crp->crp_etype == EAGAIN) {
76 		if (g_eli_crypto_rerun(crp) == 0)
77 			return (0);
78 	}
79 	bp = (struct bio *)crp->crp_opaque;
80 	bp->bio_inbed++;
81 	if (crp->crp_etype == 0) {
82 		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
83 		    bp->bio_inbed, bp->bio_children);
84 		bp->bio_completed += crp->crp_olen;
85 	} else {
86 		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
87 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
88 		if (bp->bio_error == 0)
89 			bp->bio_error = crp->crp_etype;
90 	}
91 	sc = bp->bio_to->geom->softc;
92 	if (sc != NULL)
93 		g_eli_key_drop(sc, crp->crp_desc->crd_key);
94 	/*
95 	 * Do we have all sectors already?
96 	 */
97 	if (bp->bio_inbed < bp->bio_children)
98 		return (0);
99 	free(bp->bio_driver2, M_ELI);
100 	bp->bio_driver2 = NULL;
101 	if (bp->bio_error != 0) {
102 		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
103 		    bp->bio_error);
104 		bp->bio_completed = 0;
105 	}
106 	/*
107 	 * Read is finished, send it up.
108 	 */
109 	g_io_deliver(bp, bp->bio_error);
110 	if (sc != NULL)
111 		atomic_subtract_int(&sc->sc_inflight, 1);
112 	return (0);
113 }
114 
115 /*
116  * The function is called after data encryption.
117  *
118  * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
119  */
120 static int
121 g_eli_crypto_write_done(struct cryptop *crp)
122 {
123 	struct g_eli_softc *sc;
124 	struct g_geom *gp;
125 	struct g_consumer *cp;
126 	struct bio *bp, *cbp;
127 
128 	if (crp->crp_etype == EAGAIN) {
129 		if (g_eli_crypto_rerun(crp) == 0)
130 			return (0);
131 	}
132 	bp = (struct bio *)crp->crp_opaque;
133 	bp->bio_inbed++;
134 	if (crp->crp_etype == 0) {
135 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
136 		    bp->bio_inbed, bp->bio_children);
137 	} else {
138 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
139 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
140 		if (bp->bio_error == 0)
141 			bp->bio_error = crp->crp_etype;
142 	}
143 	gp = bp->bio_to->geom;
144 	sc = gp->softc;
145 	g_eli_key_drop(sc, crp->crp_desc->crd_key);
146 	/*
147 	 * All sectors are already encrypted?
148 	 */
149 	if (bp->bio_inbed < bp->bio_children)
150 		return (0);
151 	bp->bio_inbed = 0;
152 	bp->bio_children = 1;
153 	cbp = bp->bio_driver1;
154 	bp->bio_driver1 = NULL;
155 	if (bp->bio_error != 0) {
156 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
157 		    bp->bio_error);
158 		free(bp->bio_driver2, M_ELI);
159 		bp->bio_driver2 = NULL;
160 		g_destroy_bio(cbp);
161 		g_io_deliver(bp, bp->bio_error);
162 		atomic_subtract_int(&sc->sc_inflight, 1);
163 		return (0);
164 	}
165 	cbp->bio_data = bp->bio_driver2;
166 	cbp->bio_done = g_eli_write_done;
167 	cp = LIST_FIRST(&gp->consumer);
168 	cbp->bio_to = cp->provider;
169 	G_ELI_LOGREQ(2, cbp, "Sending request.");
170 	/*
171 	 * Send encrypted data to the provider.
172 	 */
173 	g_io_request(cbp, cp);
174 	return (0);
175 }
176 
177 /*
178  * The function is called to read encrypted data.
179  *
180  * g_eli_start -> G_ELI_CRYPTO_READ -> g_io_request -> g_eli_read_done -> g_eli_crypto_run -> g_eli_crypto_read_done -> g_io_deliver
181  */
182 void
183 g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
184 {
185 	struct g_consumer *cp;
186 	struct bio *cbp;
187 
188 	if (!fromworker) {
189 		/*
190 		 * We are not called from the worker thread, so check if
191 		 * device is suspended.
192 		 */
193 		mtx_lock(&sc->sc_queue_mtx);
194 		if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
195 			/*
196 			 * If device is suspended, we place the request onto
197 			 * the queue, so it can be handled after resume.
198 			 */
199 			G_ELI_DEBUG(0, "device suspended, move onto queue");
200 			bioq_insert_tail(&sc->sc_queue, bp);
201 			mtx_unlock(&sc->sc_queue_mtx);
202 			wakeup(sc);
203 			return;
204 		}
205 		atomic_add_int(&sc->sc_inflight, 1);
206 		mtx_unlock(&sc->sc_queue_mtx);
207 	}
208 	bp->bio_pflags = 0;
209 	bp->bio_driver2 = NULL;
210 	cbp = bp->bio_driver1;
211 	cbp->bio_done = g_eli_read_done;
212 	cp = LIST_FIRST(&sc->sc_geom->consumer);
213 	cbp->bio_to = cp->provider;
214 	G_ELI_LOGREQ(2, cbp, "Sending request.");
215 	/*
216 	 * Read encrypted data from provider.
217 	 */
218 	g_io_request(cbp, cp);
219 }
220 
221 /*
222  * This is the main function responsible for cryptography (ie. communication
223  * with crypto(9) subsystem).
224  *
225  * BIO_READ:
226  *	g_eli_start -> g_eli_crypto_read -> g_io_request -> g_eli_read_done -> G_ELI_CRYPTO_RUN -> g_eli_crypto_read_done -> g_io_deliver
227  * BIO_WRITE:
228  *	g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
229  */
230 void
231 g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
232 {
233 	struct g_eli_softc *sc;
234 	struct cryptop *crp;
235 	struct cryptodesc *crd;
236 	u_int i, nsec, secsize;
237 	off_t dstoff;
238 	size_t size;
239 	u_char *p, *data;
240 	int error;
241 
242 	G_ELI_LOGREQ(3, bp, "%s", __func__);
243 
244 	bp->bio_pflags = wr->w_number;
245 	sc = wr->w_softc;
246 	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
247 	nsec = bp->bio_length / secsize;
248 
249 	/*
250 	 * Calculate how much memory do we need.
251 	 * We need separate crypto operation for every single sector.
252 	 * It is much faster to calculate total amount of needed memory here and
253 	 * do the allocation once instead of allocating memory in pieces (many,
254 	 * many pieces).
255 	 */
256 	size = sizeof(*crp) * nsec;
257 	size += sizeof(*crd) * nsec;
258 	/*
259 	 * If we write the data we cannot destroy current bio_data content,
260 	 * so we need to allocate more memory for encrypted data.
261 	 */
262 	if (bp->bio_cmd == BIO_WRITE)
263 		size += bp->bio_length;
264 	p = malloc(size, M_ELI, M_WAITOK);
265 
266 	bp->bio_inbed = 0;
267 	bp->bio_children = nsec;
268 	bp->bio_driver2 = p;
269 
270 	if (bp->bio_cmd == BIO_READ)
271 		data = bp->bio_data;
272 	else {
273 		data = p;
274 		p += bp->bio_length;
275 		bcopy(bp->bio_data, data, bp->bio_length);
276 	}
277 
278 	for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
279 		crp = (struct cryptop *)p;	p += sizeof(*crp);
280 		crd = (struct cryptodesc *)p;	p += sizeof(*crd);
281 
282 		crp->crp_session = wr->w_sid;
283 		crp->crp_ilen = secsize;
284 		crp->crp_olen = secsize;
285 		crp->crp_opaque = (void *)bp;
286 		crp->crp_buf = (void *)data;
287 		data += secsize;
288 		if (bp->bio_cmd == BIO_WRITE)
289 			crp->crp_callback = g_eli_crypto_write_done;
290 		else /* if (bp->bio_cmd == BIO_READ) */
291 			crp->crp_callback = g_eli_crypto_read_done;
292 		crp->crp_flags = CRYPTO_F_CBIFSYNC;
293 		if (g_eli_batch)
294 			crp->crp_flags |= CRYPTO_F_BATCH;
295 		crp->crp_desc = crd;
296 
297 		crd->crd_skip = 0;
298 		crd->crd_len = secsize;
299 		crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
300 		if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) == 0)
301 			crd->crd_flags |= CRD_F_KEY_EXPLICIT;
302 		if (bp->bio_cmd == BIO_WRITE)
303 			crd->crd_flags |= CRD_F_ENCRYPT;
304 		crd->crd_alg = sc->sc_ealgo;
305 		crd->crd_key = g_eli_key_hold(sc, dstoff, secsize);
306 		crd->crd_klen = sc->sc_ekeylen;
307 		if (sc->sc_ealgo == CRYPTO_AES_XTS)
308 			crd->crd_klen <<= 1;
309 		g_eli_crypto_ivgen(sc, dstoff, crd->crd_iv,
310 		    sizeof(crd->crd_iv));
311 		crd->crd_next = NULL;
312 
313 		crp->crp_etype = 0;
314 		error = crypto_dispatch(crp);
315 		KASSERT(error == 0, ("crypto_dispatch() failed (error=%d)",
316 		    error));
317 	}
318 }
319