xref: /freebsd/sys/geom/eli/g_eli_privacy.c (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992)
1 /*-
2  * Copyright (c) 2005-2010 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("$FreeBSD$");
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_eli_crypto_read -> 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 
61 MALLOC_DECLARE(M_ELI);
62 
63 /*
64  * The function is called after we read and decrypt data.
65  *
66  * 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
67  */
68 static int
69 g_eli_crypto_read_done(struct cryptop *crp)
70 {
71 	struct g_eli_softc *sc;
72 	struct bio *bp;
73 
74 	if (crp->crp_etype == EAGAIN) {
75 		if (g_eli_crypto_rerun(crp) == 0)
76 			return (0);
77 	}
78 	bp = (struct bio *)crp->crp_opaque;
79 	bp->bio_inbed++;
80 	if (crp->crp_etype == 0) {
81 		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
82 		    bp->bio_inbed, bp->bio_children);
83 		bp->bio_completed += crp->crp_olen;
84 	} else {
85 		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
86 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
87 		if (bp->bio_error == 0)
88 			bp->bio_error = crp->crp_etype;
89 	}
90 	/*
91 	 * Do we have all sectors already?
92 	 */
93 	if (bp->bio_inbed < bp->bio_children)
94 		return (0);
95 	free(bp->bio_driver2, M_ELI);
96 	bp->bio_driver2 = NULL;
97 	if (bp->bio_error != 0) {
98 		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
99 		    bp->bio_error);
100 		bp->bio_completed = 0;
101 	}
102 	/*
103 	 * Read is finished, send it up.
104 	 */
105 	sc = bp->bio_to->geom->softc;
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 	/*
140 	 * All sectors are already encrypted?
141 	 */
142 	if (bp->bio_inbed < bp->bio_children)
143 		return (0);
144 	bp->bio_inbed = 0;
145 	bp->bio_children = 1;
146 	cbp = bp->bio_driver1;
147 	bp->bio_driver1 = NULL;
148 	gp = bp->bio_to->geom;
149 	if (bp->bio_error != 0) {
150 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
151 		    bp->bio_error);
152 		free(bp->bio_driver2, M_ELI);
153 		bp->bio_driver2 = NULL;
154 		g_destroy_bio(cbp);
155 		sc = gp->softc;
156 		g_io_deliver(bp, bp->bio_error);
157 		atomic_subtract_int(&sc->sc_inflight, 1);
158 		return (0);
159 	}
160 	cbp->bio_data = bp->bio_driver2;
161 	cbp->bio_done = g_eli_write_done;
162 	cp = LIST_FIRST(&gp->consumer);
163 	cbp->bio_to = cp->provider;
164 	G_ELI_LOGREQ(2, cbp, "Sending request.");
165 	/*
166 	 * Send encrypted data to the provider.
167 	 */
168 	g_io_request(cbp, cp);
169 	return (0);
170 }
171 
172 /*
173  * The function is called to read encrypted data.
174  *
175  * 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
176  */
177 void
178 g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
179 {
180 	struct g_consumer *cp;
181 	struct bio *cbp;
182 
183 	if (!fromworker) {
184 		/*
185 		 * We are not called from the worker thread, so check if
186 		 * device is suspended.
187 		 */
188 		mtx_lock(&sc->sc_queue_mtx);
189 		if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
190 			/*
191 			 * If device is suspended, we place the request onto
192 			 * the queue, so it can be handled after resume.
193 			 */
194 			G_ELI_DEBUG(0, "device suspended, move onto queue");
195 			bioq_insert_tail(&sc->sc_queue, bp);
196 			mtx_unlock(&sc->sc_queue_mtx);
197 			wakeup(sc);
198 			return;
199 		}
200 		atomic_add_int(&sc->sc_inflight, 1);
201 		mtx_unlock(&sc->sc_queue_mtx);
202 	}
203 	bp->bio_pflags = 0;
204 	bp->bio_driver2 = NULL;
205 	cbp = bp->bio_driver1;
206 	cbp->bio_done = g_eli_read_done;
207 	cp = LIST_FIRST(&sc->sc_geom->consumer);
208 	cbp->bio_to = cp->provider;
209 	G_ELI_LOGREQ(2, cbp, "Sending request.");
210 	/*
211 	 * Read encrypted data from provider.
212 	 */
213 	g_io_request(cbp, cp);
214 }
215 
216 /*
217  * This is the main function responsible for cryptography (ie. communication
218  * with crypto(9) subsystem).
219  *
220  * BIO_READ:
221  *	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
222  * BIO_WRITE:
223  *	g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
224  */
225 void
226 g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
227 {
228 	struct g_eli_softc *sc;
229 	struct cryptop *crp;
230 	struct cryptodesc *crd;
231 	struct uio *uio;
232 	struct iovec *iov;
233 	u_int i, nsec, secsize;
234 	int err, error;
235 	off_t dstoff;
236 	size_t size;
237 	u_char *p, *data;
238 
239 	G_ELI_LOGREQ(3, bp, "%s", __func__);
240 
241 	bp->bio_pflags = wr->w_number;
242 	sc = wr->w_softc;
243 	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
244 	nsec = bp->bio_length / secsize;
245 
246 	/*
247 	 * Calculate how much memory do we need.
248 	 * We need separate crypto operation for every single sector.
249 	 * It is much faster to calculate total amount of needed memory here and
250 	 * do the allocation once instead of allocating memory in pieces (many,
251 	 * many pieces).
252 	 */
253 	size = sizeof(*crp) * nsec;
254 	size += sizeof(*crd) * nsec;
255 	size += sizeof(*uio) * nsec;
256 	size += sizeof(*iov) * nsec;
257 	/*
258 	 * If we write the data we cannot destroy current bio_data content,
259 	 * so we need to allocate more memory for encrypted data.
260 	 */
261 	if (bp->bio_cmd == BIO_WRITE)
262 		size += bp->bio_length;
263 	p = malloc(size, M_ELI, M_WAITOK);
264 
265 	bp->bio_inbed = 0;
266 	bp->bio_children = nsec;
267 	bp->bio_driver2 = p;
268 
269 	if (bp->bio_cmd == BIO_READ)
270 		data = bp->bio_data;
271 	else {
272 		data = p;
273 		p += bp->bio_length;
274 		bcopy(bp->bio_data, data, bp->bio_length);
275 	}
276 
277 	error = 0;
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 		uio = (struct uio *)p;		p += sizeof(*uio);
282 		iov = (struct iovec *)p;	p += sizeof(*iov);
283 
284 		iov->iov_len = secsize;
285 		iov->iov_base = data;
286 		data += secsize;
287 
288 		uio->uio_iov = iov;
289 		uio->uio_iovcnt = 1;
290 		uio->uio_segflg = UIO_SYSSPACE;
291 		uio->uio_resid = secsize;
292 
293 		crp->crp_sid = wr->w_sid;
294 		crp->crp_ilen = secsize;
295 		crp->crp_olen = secsize;
296 		crp->crp_opaque = (void *)bp;
297 		crp->crp_buf = (void *)uio;
298 		if (bp->bio_cmd == BIO_WRITE)
299 			crp->crp_callback = g_eli_crypto_write_done;
300 		else /* if (bp->bio_cmd == BIO_READ) */
301 			crp->crp_callback = g_eli_crypto_read_done;
302 		crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_CBIFSYNC | CRYPTO_F_REL;
303 		if (g_eli_batch)
304 			crp->crp_flags |= CRYPTO_F_BATCH;
305 		crp->crp_desc = crd;
306 
307 		crd->crd_skip = 0;
308 		crd->crd_len = secsize;
309 		crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
310 		if (sc->sc_nekeys > 1)
311 			crd->crd_flags |= CRD_F_KEY_EXPLICIT;
312 		if (bp->bio_cmd == BIO_WRITE)
313 			crd->crd_flags |= CRD_F_ENCRYPT;
314 		crd->crd_alg = sc->sc_ealgo;
315 		crd->crd_key = g_eli_crypto_key(sc, dstoff, secsize);
316 		crd->crd_klen = sc->sc_ekeylen;
317 		if (sc->sc_ealgo == CRYPTO_AES_XTS)
318 			crd->crd_klen <<= 1;
319 		g_eli_crypto_ivgen(sc, dstoff, crd->crd_iv,
320 		    sizeof(crd->crd_iv));
321 		crd->crd_next = NULL;
322 
323 		crp->crp_etype = 0;
324 		err = crypto_dispatch(crp);
325 		if (error == 0)
326 			error = err;
327 	}
328 	if (bp->bio_error == 0)
329 		bp->bio_error = error;
330 }
331