xref: /freebsd/sys/geom/eli/g_eli_privacy.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
32 #include <sys/linker.h>
33 #include <sys/module.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/bio.h>
37 #include <sys/sysctl.h>
38 #include <sys/kthread.h>
39 #include <sys/proc.h>
40 #include <sys/sched.h>
41 #include <sys/smp.h>
42 #include <sys/vnode.h>
43 
44 #include <vm/uma.h>
45 
46 #include <geom/geom.h>
47 #include <geom/geom_dbg.h>
48 #include <geom/eli/g_eli.h>
49 #include <geom/eli/pkcs5v2.h>
50 
51 /*
52  * Code paths:
53  * BIO_READ:
54  *	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
55  * BIO_WRITE:
56  *	g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
57  */
58 
59 /*
60  * Copy data from a (potentially unmapped) bio to a kernelspace buffer.
61  *
62  * The buffer must have at least as much room as bp->bio_length.
63  */
64 static void
65 g_eli_bio_copyin(struct bio *bp, void *kaddr)
66 {
67 	struct uio uio;
68 	struct iovec iov[1];
69 
70 	iov[0].iov_base = kaddr;
71 	iov[0].iov_len = bp->bio_length;
72 	uio.uio_iov = iov;
73 	uio.uio_iovcnt = 1;
74 	uio.uio_offset = 0;
75 	uio.uio_resid = bp->bio_length;
76 	uio.uio_segflg = UIO_SYSSPACE;
77 	uio.uio_rw = UIO_READ;
78 	uiomove_fromphys(bp->bio_ma, bp->bio_ma_offset, bp->bio_length, &uio);
79 }
80 
81 /*
82  * The function is called after we read and decrypt data.
83  *
84  * 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
85  */
86 static int
87 g_eli_crypto_read_done(struct cryptop *crp)
88 {
89 	struct g_eli_softc *sc;
90 	struct bio *bp;
91 
92 	if (crp->crp_etype == EAGAIN) {
93 		if (g_eli_crypto_rerun(crp) == 0)
94 			return (0);
95 	}
96 	bp = (struct bio *)crp->crp_opaque;
97 	bp->bio_inbed++;
98 	if (crp->crp_etype == 0) {
99 		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
100 		    bp->bio_inbed, bp->bio_children);
101 		bp->bio_completed += crp->crp_payload_length;
102 	} else {
103 		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
104 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
105 		if (bp->bio_error == 0)
106 			bp->bio_error = crp->crp_etype;
107 	}
108 	sc = bp->bio_to->geom->softc;
109 	if (sc != NULL && crp->crp_cipher_key != NULL)
110 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
111 	crypto_freereq(crp);
112 	/*
113 	 * Do we have all sectors already?
114 	 */
115 	if (bp->bio_inbed < bp->bio_children)
116 		return (0);
117 
118 	if (bp->bio_error != 0) {
119 		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
120 		    bp->bio_error);
121 		bp->bio_completed = 0;
122 	}
123 	/*
124 	 * Read is finished, send it up.
125 	 */
126 	g_io_deliver(bp, bp->bio_error);
127 	if (sc != NULL)
128 		atomic_subtract_int(&sc->sc_inflight, 1);
129 	return (0);
130 }
131 
132 /*
133  * The function is called after data encryption.
134  *
135  * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
136  */
137 static int
138 g_eli_crypto_write_done(struct cryptop *crp)
139 {
140 	struct g_eli_softc *sc;
141 	struct g_geom *gp;
142 	struct g_consumer *cp;
143 	struct bio *bp, *cbp;
144 
145 	if (crp->crp_etype == EAGAIN) {
146 		if (g_eli_crypto_rerun(crp) == 0)
147 			return (0);
148 	}
149 	bp = (struct bio *)crp->crp_opaque;
150 	bp->bio_inbed++;
151 	if (crp->crp_etype == 0) {
152 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
153 		    bp->bio_inbed, bp->bio_children);
154 	} else {
155 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
156 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
157 		if (bp->bio_error == 0)
158 			bp->bio_error = crp->crp_etype;
159 	}
160 	gp = bp->bio_to->geom;
161 	sc = gp->softc;
162 	if (crp->crp_cipher_key != NULL)
163 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
164 	crypto_freereq(crp);
165 	/*
166 	 * All sectors are already encrypted?
167 	 */
168 	if (bp->bio_inbed < bp->bio_children)
169 		return (0);
170 	bp->bio_inbed = 0;
171 	bp->bio_children = 1;
172 	cbp = bp->bio_driver1;
173 	bp->bio_driver1 = NULL;
174 	if (bp->bio_error != 0) {
175 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
176 		    bp->bio_error);
177 		g_eli_free_data(bp);
178 		g_destroy_bio(cbp);
179 		g_io_deliver(bp, bp->bio_error);
180 		atomic_subtract_int(&sc->sc_inflight, 1);
181 		return (0);
182 	}
183 	cbp->bio_data = bp->bio_driver2;
184 	/*
185 	 * Clear BIO_UNMAPPED, which was inherited from where we cloned the bio
186 	 * in g_eli_start, because we manually set bio_data
187 	 */
188 	cbp->bio_flags &= ~BIO_UNMAPPED;
189 	cbp->bio_done = g_eli_write_done;
190 	cp = LIST_FIRST(&gp->consumer);
191 	cbp->bio_to = cp->provider;
192 	G_ELI_LOGREQ(2, cbp, "Sending request.");
193 	/*
194 	 * Send encrypted data to the provider.
195 	 */
196 	g_io_request(cbp, cp);
197 	return (0);
198 }
199 
200 /*
201  * The function is called to read encrypted data.
202  *
203  * 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
204  */
205 void
206 g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
207 {
208 	struct g_consumer *cp;
209 	struct bio *cbp;
210 
211 	if (!fromworker) {
212 		/*
213 		 * We are not called from the worker thread, so check if
214 		 * device is suspended.
215 		 */
216 		mtx_lock(&sc->sc_queue_mtx);
217 		if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
218 			/*
219 			 * If device is suspended, we place the request onto
220 			 * the queue, so it can be handled after resume.
221 			 */
222 			G_ELI_DEBUG(0, "device suspended, move onto queue");
223 			bioq_insert_tail(&sc->sc_queue, bp);
224 			mtx_unlock(&sc->sc_queue_mtx);
225 			wakeup(sc);
226 			return;
227 		}
228 		atomic_add_int(&sc->sc_inflight, 1);
229 		mtx_unlock(&sc->sc_queue_mtx);
230 	}
231 	G_ELI_SETWORKER(bp->bio_pflags, 0);
232 	bp->bio_driver2 = NULL;
233 	cbp = bp->bio_driver1;
234 	cbp->bio_done = g_eli_read_done;
235 	cp = LIST_FIRST(&sc->sc_geom->consumer);
236 	cbp->bio_to = cp->provider;
237 	G_ELI_LOGREQ(2, cbp, "Sending request.");
238 	/*
239 	 * Read encrypted data from provider.
240 	 */
241 	g_io_request(cbp, cp);
242 }
243 
244 /*
245  * This is the main function responsible for cryptography (ie. communication
246  * with crypto(9) subsystem).
247  *
248  * BIO_READ:
249  *	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
250  * BIO_WRITE:
251  *	g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
252  */
253 void
254 g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
255 {
256 	struct g_eli_softc *sc;
257 	struct cryptopq crpq;
258 	struct cryptop *crp;
259 	vm_page_t *pages;
260 	u_int i, nsec, secsize;
261 	off_t dstoff;
262 	u_char *data = NULL;
263 	int error __diagused, pages_offset;
264 	bool batch;
265 
266 	G_ELI_LOGREQ(3, bp, "%s", __func__);
267 
268 	G_ELI_SETWORKER(bp->bio_pflags, wr->w_number);
269 	sc = wr->w_softc;
270 	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
271 	nsec = bp->bio_length / secsize;
272 
273 	bp->bio_inbed = 0;
274 	bp->bio_children = nsec;
275 
276 	/*
277 	 * If we write the data we cannot destroy current bio_data content,
278 	 * so we need to allocate more memory for encrypted data.
279 	 */
280 	if (bp->bio_cmd == BIO_WRITE) {
281 		if (!g_eli_alloc_data(bp, bp->bio_length)) {
282 			G_ELI_LOGREQ(0, bp, "Crypto request failed (ENOMEM).");
283 			if (bp->bio_driver1 != NULL) {
284 				g_destroy_bio(bp->bio_driver1);
285 				bp->bio_driver1 = NULL;
286 			}
287 			bp->bio_error = ENOMEM;
288 			g_io_deliver(bp, bp->bio_error);
289 			if (sc != NULL)
290 				atomic_subtract_int(&sc->sc_inflight, 1);
291 			return;
292 		}
293 		data = bp->bio_driver2;
294 		/*
295 		 * This copy could be eliminated by using crypto's output
296 		 * buffer, instead of using a single overwriting buffer.
297 		 */
298 		if ((bp->bio_flags & BIO_UNMAPPED) != 0)
299 			g_eli_bio_copyin(bp, data);
300 		else
301 			bcopy(bp->bio_data, data, bp->bio_length);
302 	} else {
303 		if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
304 			pages = bp->bio_ma;
305 			pages_offset = bp->bio_ma_offset;
306 		} else {
307 			data = bp->bio_data;
308 		}
309 	}
310 
311 	TAILQ_INIT(&crpq);
312 	batch = atomic_load_int(&g_eli_batch) != 0;
313 
314 	for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
315 		crp = crypto_getreq(wr->w_sid, M_WAITOK);
316 
317 		if (data) {
318 			crypto_use_buf(crp, data, secsize);
319 			data += secsize;
320 		} else {
321 			MPASS(pages != NULL);
322 			crypto_use_vmpage(crp, pages, secsize, pages_offset);
323 			pages_offset += secsize;
324 			pages += pages_offset >> PAGE_SHIFT;
325 			pages_offset &= PAGE_MASK;
326 		}
327 		crp->crp_opaque = (void *)bp;
328 		if (bp->bio_cmd == BIO_WRITE) {
329 			crp->crp_op = CRYPTO_OP_ENCRYPT;
330 			crp->crp_callback = g_eli_crypto_write_done;
331 		} else /* if (bp->bio_cmd == BIO_READ) */ {
332 			crp->crp_op = CRYPTO_OP_DECRYPT;
333 			crp->crp_callback = g_eli_crypto_read_done;
334 		}
335 		crp->crp_flags = CRYPTO_F_CBIFSYNC;
336 		crp->crp_payload_start = 0;
337 		crp->crp_payload_length = secsize;
338 		if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) == 0) {
339 			crp->crp_cipher_key = g_eli_key_hold(sc, dstoff,
340 			    secsize);
341 		}
342 		if (g_eli_ivlen(sc->sc_ealgo) != 0) {
343 			crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
344 			g_eli_crypto_ivgen(sc, dstoff, crp->crp_iv,
345 			    sizeof(crp->crp_iv));
346 		}
347 
348 		if (batch) {
349 			TAILQ_INSERT_TAIL(&crpq, crp, crp_next);
350 		} else {
351 			error = crypto_dispatch(crp);
352 			KASSERT(error == 0,
353 			    ("crypto_dispatch() failed (error=%d)", error));
354 		}
355 	}
356 
357 	if (batch)
358 		crypto_dispatch_batch(&crpq, 0);
359 }
360