xref: /freebsd/sys/geom/eli/g_eli_privacy.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/kthread.h>
42 #include <sys/proc.h>
43 #include <sys/sched.h>
44 #include <sys/smp.h>
45 #include <sys/vnode.h>
46 
47 #include <vm/uma.h>
48 
49 #include <geom/geom.h>
50 #include <geom/geom_dbg.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 /*
63  * Copy data from a (potentially unmapped) bio to a kernelspace buffer.
64  *
65  * The buffer must have at least as much room as bp->bio_length.
66  */
67 static void
68 g_eli_bio_copyin(struct bio *bp, void *kaddr)
69 {
70 	struct uio uio;
71 	struct iovec iov[1];
72 
73 	iov[0].iov_base = kaddr;
74 	iov[0].iov_len = bp->bio_length;
75 	uio.uio_iov = iov;
76 	uio.uio_iovcnt = 1;
77 	uio.uio_offset = 0;
78 	uio.uio_resid = bp->bio_length;
79 	uio.uio_segflg = UIO_SYSSPACE;
80 	uio.uio_rw = UIO_READ;
81 	uiomove_fromphys(bp->bio_ma, bp->bio_ma_offset, bp->bio_length, &uio);
82 }
83 
84 /*
85  * The function is called after we read and decrypt data.
86  *
87  * 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
88  */
89 static int
90 g_eli_crypto_read_done(struct cryptop *crp)
91 {
92 	struct g_eli_softc *sc;
93 	struct bio *bp;
94 
95 	if (crp->crp_etype == EAGAIN) {
96 		if (g_eli_crypto_rerun(crp) == 0)
97 			return (0);
98 	}
99 	bp = (struct bio *)crp->crp_opaque;
100 	bp->bio_inbed++;
101 	if (crp->crp_etype == 0) {
102 		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
103 		    bp->bio_inbed, bp->bio_children);
104 		bp->bio_completed += crp->crp_payload_length;
105 	} else {
106 		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
107 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
108 		if (bp->bio_error == 0)
109 			bp->bio_error = crp->crp_etype;
110 	}
111 	sc = bp->bio_to->geom->softc;
112 	if (sc != NULL && crp->crp_cipher_key != NULL)
113 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
114 	crypto_freereq(crp);
115 	/*
116 	 * Do we have all sectors already?
117 	 */
118 	if (bp->bio_inbed < bp->bio_children)
119 		return (0);
120 
121 	if (bp->bio_error != 0) {
122 		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
123 		    bp->bio_error);
124 		bp->bio_completed = 0;
125 	}
126 	/*
127 	 * Read is finished, send it up.
128 	 */
129 	g_io_deliver(bp, bp->bio_error);
130 	if (sc != NULL)
131 		atomic_subtract_int(&sc->sc_inflight, 1);
132 	return (0);
133 }
134 
135 /*
136  * The function is called after data encryption.
137  *
138  * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
139  */
140 static int
141 g_eli_crypto_write_done(struct cryptop *crp)
142 {
143 	struct g_eli_softc *sc;
144 	struct g_geom *gp;
145 	struct g_consumer *cp;
146 	struct bio *bp, *cbp;
147 
148 	if (crp->crp_etype == EAGAIN) {
149 		if (g_eli_crypto_rerun(crp) == 0)
150 			return (0);
151 	}
152 	bp = (struct bio *)crp->crp_opaque;
153 	bp->bio_inbed++;
154 	if (crp->crp_etype == 0) {
155 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
156 		    bp->bio_inbed, bp->bio_children);
157 	} else {
158 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
159 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
160 		if (bp->bio_error == 0)
161 			bp->bio_error = crp->crp_etype;
162 	}
163 	gp = bp->bio_to->geom;
164 	sc = gp->softc;
165 	if (crp->crp_cipher_key != NULL)
166 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
167 	crypto_freereq(crp);
168 	/*
169 	 * All sectors are already encrypted?
170 	 */
171 	if (bp->bio_inbed < bp->bio_children)
172 		return (0);
173 	bp->bio_inbed = 0;
174 	bp->bio_children = 1;
175 	cbp = bp->bio_driver1;
176 	bp->bio_driver1 = NULL;
177 	if (bp->bio_error != 0) {
178 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
179 		    bp->bio_error);
180 		g_eli_free_data(bp);
181 		g_destroy_bio(cbp);
182 		g_io_deliver(bp, bp->bio_error);
183 		atomic_subtract_int(&sc->sc_inflight, 1);
184 		return (0);
185 	}
186 	cbp->bio_data = bp->bio_driver2;
187 	/*
188 	 * Clear BIO_UNMAPPED, which was inherited from where we cloned the bio
189 	 * in g_eli_start, because we manually set bio_data
190 	 */
191 	cbp->bio_flags &= ~BIO_UNMAPPED;
192 	cbp->bio_done = g_eli_write_done;
193 	cp = LIST_FIRST(&gp->consumer);
194 	cbp->bio_to = cp->provider;
195 	G_ELI_LOGREQ(2, cbp, "Sending request.");
196 	/*
197 	 * Send encrypted data to the provider.
198 	 */
199 	g_io_request(cbp, cp);
200 	return (0);
201 }
202 
203 /*
204  * The function is called to read encrypted data.
205  *
206  * 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
207  */
208 void
209 g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
210 {
211 	struct g_consumer *cp;
212 	struct bio *cbp;
213 
214 	if (!fromworker) {
215 		/*
216 		 * We are not called from the worker thread, so check if
217 		 * device is suspended.
218 		 */
219 		mtx_lock(&sc->sc_queue_mtx);
220 		if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
221 			/*
222 			 * If device is suspended, we place the request onto
223 			 * the queue, so it can be handled after resume.
224 			 */
225 			G_ELI_DEBUG(0, "device suspended, move onto queue");
226 			bioq_insert_tail(&sc->sc_queue, bp);
227 			mtx_unlock(&sc->sc_queue_mtx);
228 			wakeup(sc);
229 			return;
230 		}
231 		atomic_add_int(&sc->sc_inflight, 1);
232 		mtx_unlock(&sc->sc_queue_mtx);
233 	}
234 	G_ELI_SETWORKER(bp->bio_pflags, 0);
235 	bp->bio_driver2 = NULL;
236 	cbp = bp->bio_driver1;
237 	cbp->bio_done = g_eli_read_done;
238 	cp = LIST_FIRST(&sc->sc_geom->consumer);
239 	cbp->bio_to = cp->provider;
240 	G_ELI_LOGREQ(2, cbp, "Sending request.");
241 	/*
242 	 * Read encrypted data from provider.
243 	 */
244 	g_io_request(cbp, cp);
245 }
246 
247 /*
248  * This is the main function responsible for cryptography (ie. communication
249  * with crypto(9) subsystem).
250  *
251  * BIO_READ:
252  *	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
253  * BIO_WRITE:
254  *	g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
255  */
256 void
257 g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
258 {
259 	struct g_eli_softc *sc;
260 	struct cryptopq crpq;
261 	struct cryptop *crp;
262 	vm_page_t *pages;
263 	u_int i, nsec, secsize;
264 	off_t dstoff;
265 	u_char *data = NULL;
266 	int error __diagused, pages_offset;
267 	bool batch;
268 
269 	G_ELI_LOGREQ(3, bp, "%s", __func__);
270 
271 	G_ELI_SETWORKER(bp->bio_pflags, wr->w_number);
272 	sc = wr->w_softc;
273 	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
274 	nsec = bp->bio_length / secsize;
275 
276 	bp->bio_inbed = 0;
277 	bp->bio_children = nsec;
278 
279 	/*
280 	 * If we write the data we cannot destroy current bio_data content,
281 	 * so we need to allocate more memory for encrypted data.
282 	 */
283 	if (bp->bio_cmd == BIO_WRITE) {
284 		if (!g_eli_alloc_data(bp, bp->bio_length)) {
285 			G_ELI_LOGREQ(0, bp, "Crypto request failed (ENOMEM).");
286 			if (bp->bio_driver1 != NULL) {
287 				g_destroy_bio(bp->bio_driver1);
288 				bp->bio_driver1 = NULL;
289 			}
290 			bp->bio_error = ENOMEM;
291 			g_io_deliver(bp, bp->bio_error);
292 			if (sc != NULL)
293 				atomic_subtract_int(&sc->sc_inflight, 1);
294 			return;
295 		}
296 		data = bp->bio_driver2;
297 		/*
298 		 * This copy could be eliminated by using crypto's output
299 		 * buffer, instead of using a single overwriting buffer.
300 		 */
301 		if ((bp->bio_flags & BIO_UNMAPPED) != 0)
302 			g_eli_bio_copyin(bp, data);
303 		else
304 			bcopy(bp->bio_data, data, bp->bio_length);
305 	} else {
306 		if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
307 			pages = bp->bio_ma;
308 			pages_offset = bp->bio_ma_offset;
309 		} else {
310 			data = bp->bio_data;
311 		}
312 	}
313 
314 	TAILQ_INIT(&crpq);
315 	batch = atomic_load_int(&g_eli_batch) != 0;
316 
317 	for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
318 		crp = crypto_getreq(wr->w_sid, M_WAITOK);
319 
320 		if (data) {
321 			crypto_use_buf(crp, data, secsize);
322 			data += secsize;
323 		} else {
324 			MPASS(pages != NULL);
325 			crypto_use_vmpage(crp, pages, secsize, pages_offset);
326 			pages_offset += secsize;
327 			pages += pages_offset >> PAGE_SHIFT;
328 			pages_offset &= PAGE_MASK;
329 		}
330 		crp->crp_opaque = (void *)bp;
331 		if (bp->bio_cmd == BIO_WRITE) {
332 			crp->crp_op = CRYPTO_OP_ENCRYPT;
333 			crp->crp_callback = g_eli_crypto_write_done;
334 		} else /* if (bp->bio_cmd == BIO_READ) */ {
335 			crp->crp_op = CRYPTO_OP_DECRYPT;
336 			crp->crp_callback = g_eli_crypto_read_done;
337 		}
338 		crp->crp_flags = CRYPTO_F_CBIFSYNC;
339 		crp->crp_payload_start = 0;
340 		crp->crp_payload_length = secsize;
341 		if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) == 0) {
342 			crp->crp_cipher_key = g_eli_key_hold(sc, dstoff,
343 			    secsize);
344 		}
345 		if (g_eli_ivlen(sc->sc_ealgo) != 0) {
346 			crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
347 			g_eli_crypto_ivgen(sc, dstoff, crp->crp_iv,
348 			    sizeof(crp->crp_iv));
349 		}
350 
351 		if (batch) {
352 			TAILQ_INSERT_TAIL(&crpq, crp, crp_next);
353 		} else {
354 			error = crypto_dispatch(crp);
355 			KASSERT(error == 0,
356 			    ("crypto_dispatch() failed (error=%d)", error));
357 		}
358 	}
359 
360 	if (batch)
361 		crypto_dispatch_batch(&crpq, 0);
362 }
363