xref: /freebsd/sys/geom/eli/g_eli_privacy.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /*-
2  * Copyright (c) 2005-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
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("$FreeBSD$");
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/vnode.h>
45 
46 #include <vm/uma.h>
47 
48 #include <geom/geom.h>
49 #include <geom/eli/g_eli.h>
50 #include <geom/eli/pkcs5v2.h>
51 
52 /*
53  * Code paths:
54  * BIO_READ:
55  *	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
56  * BIO_WRITE:
57  *	g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
58  */
59 
60 MALLOC_DECLARE(M_ELI);
61 
62 /*
63  * The function is called after we read and decrypt data.
64  *
65  * 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
66  */
67 static int
68 g_eli_crypto_read_done(struct cryptop *crp)
69 {
70 	struct g_eli_softc *sc;
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 	sc = bp->bio_to->geom->softc;
90 	g_eli_key_drop(sc, crp->crp_desc->crd_key);
91 	/*
92 	 * Do we have all sectors already?
93 	 */
94 	if (bp->bio_inbed < bp->bio_children)
95 		return (0);
96 	free(bp->bio_driver2, M_ELI);
97 	bp->bio_driver2 = NULL;
98 	if (bp->bio_error != 0) {
99 		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
100 		    bp->bio_error);
101 		bp->bio_completed = 0;
102 	}
103 	/*
104 	 * Read is finished, send it up.
105 	 */
106 	g_io_deliver(bp, bp->bio_error);
107 	atomic_subtract_int(&sc->sc_inflight, 1);
108 	return (0);
109 }
110 
111 /*
112  * The function is called after data encryption.
113  *
114  * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
115  */
116 static int
117 g_eli_crypto_write_done(struct cryptop *crp)
118 {
119 	struct g_eli_softc *sc;
120 	struct g_geom *gp;
121 	struct g_consumer *cp;
122 	struct bio *bp, *cbp;
123 
124 	if (crp->crp_etype == EAGAIN) {
125 		if (g_eli_crypto_rerun(crp) == 0)
126 			return (0);
127 	}
128 	bp = (struct bio *)crp->crp_opaque;
129 	bp->bio_inbed++;
130 	if (crp->crp_etype == 0) {
131 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
132 		    bp->bio_inbed, bp->bio_children);
133 	} else {
134 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
135 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
136 		if (bp->bio_error == 0)
137 			bp->bio_error = crp->crp_etype;
138 	}
139 	gp = bp->bio_to->geom;
140 	sc = gp->softc;
141 	g_eli_key_drop(sc, crp->crp_desc->crd_key);
142 	/*
143 	 * All sectors are already encrypted?
144 	 */
145 	if (bp->bio_inbed < bp->bio_children)
146 		return (0);
147 	bp->bio_inbed = 0;
148 	bp->bio_children = 1;
149 	cbp = bp->bio_driver1;
150 	bp->bio_driver1 = NULL;
151 	if (bp->bio_error != 0) {
152 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
153 		    bp->bio_error);
154 		free(bp->bio_driver2, M_ELI);
155 		bp->bio_driver2 = NULL;
156 		g_destroy_bio(cbp);
157 		g_io_deliver(bp, bp->bio_error);
158 		atomic_subtract_int(&sc->sc_inflight, 1);
159 		return (0);
160 	}
161 	cbp->bio_data = bp->bio_driver2;
162 	cbp->bio_done = g_eli_write_done;
163 	cp = LIST_FIRST(&gp->consumer);
164 	cbp->bio_to = cp->provider;
165 	G_ELI_LOGREQ(2, cbp, "Sending request.");
166 	/*
167 	 * Send encrypted data to the provider.
168 	 */
169 	g_io_request(cbp, cp);
170 	return (0);
171 }
172 
173 /*
174  * The function is called to read encrypted data.
175  *
176  * 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
177  */
178 void
179 g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
180 {
181 	struct g_consumer *cp;
182 	struct bio *cbp;
183 
184 	if (!fromworker) {
185 		/*
186 		 * We are not called from the worker thread, so check if
187 		 * device is suspended.
188 		 */
189 		mtx_lock(&sc->sc_queue_mtx);
190 		if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
191 			/*
192 			 * If device is suspended, we place the request onto
193 			 * the queue, so it can be handled after resume.
194 			 */
195 			G_ELI_DEBUG(0, "device suspended, move onto queue");
196 			bioq_insert_tail(&sc->sc_queue, bp);
197 			mtx_unlock(&sc->sc_queue_mtx);
198 			wakeup(sc);
199 			return;
200 		}
201 		atomic_add_int(&sc->sc_inflight, 1);
202 		mtx_unlock(&sc->sc_queue_mtx);
203 	}
204 	bp->bio_pflags = 0;
205 	bp->bio_driver2 = NULL;
206 	cbp = bp->bio_driver1;
207 	cbp->bio_done = g_eli_read_done;
208 	cp = LIST_FIRST(&sc->sc_geom->consumer);
209 	cbp->bio_to = cp->provider;
210 	G_ELI_LOGREQ(2, cbp, "Sending request.");
211 	/*
212 	 * Read encrypted data from provider.
213 	 */
214 	g_io_request(cbp, cp);
215 }
216 
217 /*
218  * This is the main function responsible for cryptography (ie. communication
219  * with crypto(9) subsystem).
220  *
221  * BIO_READ:
222  *	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
223  * BIO_WRITE:
224  *	g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
225  */
226 void
227 g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
228 {
229 	struct g_eli_softc *sc;
230 	struct cryptop *crp;
231 	struct cryptodesc *crd;
232 	u_int i, nsec, secsize;
233 	int err, error;
234 	off_t dstoff;
235 	size_t size;
236 	u_char *p, *data;
237 
238 	G_ELI_LOGREQ(3, bp, "%s", __func__);
239 
240 	bp->bio_pflags = wr->w_number;
241 	sc = wr->w_softc;
242 	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
243 	nsec = bp->bio_length / secsize;
244 
245 	/*
246 	 * Calculate how much memory do we need.
247 	 * We need separate crypto operation for every single sector.
248 	 * It is much faster to calculate total amount of needed memory here and
249 	 * do the allocation once instead of allocating memory in pieces (many,
250 	 * many pieces).
251 	 */
252 	size = sizeof(*crp) * nsec;
253 	size += sizeof(*crd) * nsec;
254 	/*
255 	 * If we write the data we cannot destroy current bio_data content,
256 	 * so we need to allocate more memory for encrypted data.
257 	 */
258 	if (bp->bio_cmd == BIO_WRITE)
259 		size += bp->bio_length;
260 	p = malloc(size, M_ELI, M_WAITOK);
261 
262 	bp->bio_inbed = 0;
263 	bp->bio_children = nsec;
264 	bp->bio_driver2 = p;
265 
266 	if (bp->bio_cmd == BIO_READ)
267 		data = bp->bio_data;
268 	else {
269 		data = p;
270 		p += bp->bio_length;
271 		bcopy(bp->bio_data, data, bp->bio_length);
272 	}
273 
274 	error = 0;
275 	for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
276 		crp = (struct cryptop *)p;	p += sizeof(*crp);
277 		crd = (struct cryptodesc *)p;	p += sizeof(*crd);
278 
279 		crp->crp_sid = wr->w_sid;
280 		crp->crp_ilen = secsize;
281 		crp->crp_olen = secsize;
282 		crp->crp_opaque = (void *)bp;
283 		crp->crp_buf = (void *)data;
284 		data += secsize;
285 		if (bp->bio_cmd == BIO_WRITE)
286 			crp->crp_callback = g_eli_crypto_write_done;
287 		else /* if (bp->bio_cmd == BIO_READ) */
288 			crp->crp_callback = g_eli_crypto_read_done;
289 		crp->crp_flags = CRYPTO_F_CBIFSYNC | CRYPTO_F_REL;
290 		if (g_eli_batch)
291 			crp->crp_flags |= CRYPTO_F_BATCH;
292 		crp->crp_desc = crd;
293 
294 		crd->crd_skip = 0;
295 		crd->crd_len = secsize;
296 		crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
297 		if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) == 0)
298 			crd->crd_flags |= CRD_F_KEY_EXPLICIT;
299 		if (bp->bio_cmd == BIO_WRITE)
300 			crd->crd_flags |= CRD_F_ENCRYPT;
301 		crd->crd_alg = sc->sc_ealgo;
302 		crd->crd_key = g_eli_key_hold(sc, dstoff, secsize);
303 		crd->crd_klen = sc->sc_ekeylen;
304 		if (sc->sc_ealgo == CRYPTO_AES_XTS)
305 			crd->crd_klen <<= 1;
306 		g_eli_crypto_ivgen(sc, dstoff, crd->crd_iv,
307 		    sizeof(crd->crd_iv));
308 		crd->crd_next = NULL;
309 
310 		crp->crp_etype = 0;
311 		err = crypto_dispatch(crp);
312 		if (error == 0)
313 			error = err;
314 	}
315 	if (bp->bio_error == 0)
316 		bp->bio_error = error;
317 }
318