xref: /freebsd/sys/geom/eli/g_eli_privacy.c (revision 1603881667360c015f6685131f2f25474fa67a72)
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/geom_dbg.h>
52 #include <geom/eli/g_eli.h>
53 #include <geom/eli/pkcs5v2.h>
54 
55 /*
56  * Code paths:
57  * BIO_READ:
58  *	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
59  * BIO_WRITE:
60  *	g_eli_start -> g_eli_crypto_run -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
61  */
62 
63 MALLOC_DECLARE(M_ELI);
64 
65 /*
66  * Copy data from a (potentially unmapped) bio to a kernelspace buffer.
67  *
68  * The buffer must have at least as much room as bp->bio_length.
69  */
70 static void
71 g_eli_bio_copyin(struct bio *bp, void *kaddr)
72 {
73 	struct uio uio;
74 	struct iovec iov[1];
75 
76 	iov[0].iov_base = kaddr;
77 	iov[0].iov_len = bp->bio_length;
78 	uio.uio_iov = iov;
79 	uio.uio_iovcnt = 1;
80 	uio.uio_offset = 0;
81 	uio.uio_resid = bp->bio_length;
82 	uio.uio_segflg = UIO_SYSSPACE;
83 	uio.uio_rw = UIO_READ;
84 	uiomove_fromphys(bp->bio_ma, bp->bio_ma_offset, bp->bio_length, &uio);
85 }
86 
87 /*
88  * The function is called after we read and decrypt data.
89  *
90  * 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
91  */
92 static int
93 g_eli_crypto_read_done(struct cryptop *crp)
94 {
95 	struct g_eli_softc *sc;
96 	struct bio *bp;
97 
98 	if (crp->crp_etype == EAGAIN) {
99 		if (g_eli_crypto_rerun(crp) == 0)
100 			return (0);
101 	}
102 	bp = (struct bio *)crp->crp_opaque;
103 	bp->bio_inbed++;
104 	if (crp->crp_etype == 0) {
105 		G_ELI_DEBUG(3, "Crypto READ request done (%d/%d).",
106 		    bp->bio_inbed, bp->bio_children);
107 		bp->bio_completed += crp->crp_payload_length;
108 	} else {
109 		G_ELI_DEBUG(1, "Crypto READ request failed (%d/%d) error=%d.",
110 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
111 		if (bp->bio_error == 0)
112 			bp->bio_error = crp->crp_etype;
113 	}
114 	sc = bp->bio_to->geom->softc;
115 	if (sc != NULL && crp->crp_cipher_key != NULL)
116 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
117 	crypto_freereq(crp);
118 	/*
119 	 * Do we have all sectors already?
120 	 */
121 	if (bp->bio_inbed < bp->bio_children)
122 		return (0);
123 
124 	if (bp->bio_error != 0) {
125 		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
126 		    bp->bio_error);
127 		bp->bio_completed = 0;
128 	}
129 	/*
130 	 * Read is finished, send it up.
131 	 */
132 	g_io_deliver(bp, bp->bio_error);
133 	if (sc != NULL)
134 		atomic_subtract_int(&sc->sc_inflight, 1);
135 	return (0);
136 }
137 
138 /*
139  * The function is called after data encryption.
140  *
141  * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
142  */
143 static int
144 g_eli_crypto_write_done(struct cryptop *crp)
145 {
146 	struct g_eli_softc *sc;
147 	struct g_geom *gp;
148 	struct g_consumer *cp;
149 	struct bio *bp, *cbp;
150 
151 	if (crp->crp_etype == EAGAIN) {
152 		if (g_eli_crypto_rerun(crp) == 0)
153 			return (0);
154 	}
155 	bp = (struct bio *)crp->crp_opaque;
156 	bp->bio_inbed++;
157 	if (crp->crp_etype == 0) {
158 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
159 		    bp->bio_inbed, bp->bio_children);
160 	} else {
161 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
162 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
163 		if (bp->bio_error == 0)
164 			bp->bio_error = crp->crp_etype;
165 	}
166 	gp = bp->bio_to->geom;
167 	sc = gp->softc;
168 	if (crp->crp_cipher_key != NULL)
169 		g_eli_key_drop(sc, __DECONST(void *, crp->crp_cipher_key));
170 	crypto_freereq(crp);
171 	/*
172 	 * All sectors are already encrypted?
173 	 */
174 	if (bp->bio_inbed < bp->bio_children)
175 		return (0);
176 	bp->bio_inbed = 0;
177 	bp->bio_children = 1;
178 	cbp = bp->bio_driver1;
179 	bp->bio_driver1 = NULL;
180 	if (bp->bio_error != 0) {
181 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
182 		    bp->bio_error);
183 		free(bp->bio_driver2, M_ELI);
184 		bp->bio_driver2 = NULL;
185 		g_destroy_bio(cbp);
186 		g_io_deliver(bp, bp->bio_error);
187 		atomic_subtract_int(&sc->sc_inflight, 1);
188 		return (0);
189 	}
190 	cbp->bio_data = bp->bio_driver2;
191 	/*
192 	 * Clear BIO_UNMAPPED, which was inherited from where we cloned the bio
193 	 * in g_eli_start, because we manually set bio_data
194 	 */
195 	cbp->bio_flags &= ~BIO_UNMAPPED;
196 	cbp->bio_done = g_eli_write_done;
197 	cp = LIST_FIRST(&gp->consumer);
198 	cbp->bio_to = cp->provider;
199 	G_ELI_LOGREQ(2, cbp, "Sending request.");
200 	/*
201 	 * Send encrypted data to the provider.
202 	 */
203 	g_io_request(cbp, cp);
204 	return (0);
205 }
206 
207 /*
208  * The function is called to read encrypted data.
209  *
210  * 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
211  */
212 void
213 g_eli_crypto_read(struct g_eli_softc *sc, struct bio *bp, boolean_t fromworker)
214 {
215 	struct g_consumer *cp;
216 	struct bio *cbp;
217 
218 	if (!fromworker) {
219 		/*
220 		 * We are not called from the worker thread, so check if
221 		 * device is suspended.
222 		 */
223 		mtx_lock(&sc->sc_queue_mtx);
224 		if (sc->sc_flags & G_ELI_FLAG_SUSPEND) {
225 			/*
226 			 * If device is suspended, we place the request onto
227 			 * the queue, so it can be handled after resume.
228 			 */
229 			G_ELI_DEBUG(0, "device suspended, move onto queue");
230 			bioq_insert_tail(&sc->sc_queue, bp);
231 			mtx_unlock(&sc->sc_queue_mtx);
232 			wakeup(sc);
233 			return;
234 		}
235 		atomic_add_int(&sc->sc_inflight, 1);
236 		mtx_unlock(&sc->sc_queue_mtx);
237 	}
238 	bp->bio_pflags = 0;
239 	bp->bio_driver2 = NULL;
240 	cbp = bp->bio_driver1;
241 	cbp->bio_done = g_eli_read_done;
242 	cp = LIST_FIRST(&sc->sc_geom->consumer);
243 	cbp->bio_to = cp->provider;
244 	G_ELI_LOGREQ(2, cbp, "Sending request.");
245 	/*
246 	 * Read encrypted data from provider.
247 	 */
248 	g_io_request(cbp, cp);
249 }
250 
251 /*
252  * This is the main function responsible for cryptography (ie. communication
253  * with crypto(9) subsystem).
254  *
255  * BIO_READ:
256  *	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
257  * BIO_WRITE:
258  *	g_eli_start -> G_ELI_CRYPTO_RUN -> g_eli_crypto_write_done -> g_io_request -> g_eli_write_done -> g_io_deliver
259  */
260 void
261 g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
262 {
263 	struct g_eli_softc *sc;
264 	struct cryptopq crpq;
265 	struct cryptop *crp;
266 	vm_page_t *pages;
267 	u_int i, nsec, secsize;
268 	off_t dstoff;
269 	u_char *data = NULL;
270 	int error, pages_offset;
271 	bool batch;
272 
273 	G_ELI_LOGREQ(3, bp, "%s", __func__);
274 
275 	bp->bio_pflags = wr->w_number;
276 	sc = wr->w_softc;
277 	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
278 	nsec = bp->bio_length / secsize;
279 
280 	bp->bio_inbed = 0;
281 	bp->bio_children = nsec;
282 
283 	/*
284 	 * If we write the data we cannot destroy current bio_data content,
285 	 * so we need to allocate more memory for encrypted data.
286 	 */
287 	if (bp->bio_cmd == BIO_WRITE) {
288 		data = malloc(bp->bio_length, M_ELI, M_WAITOK);
289 		bp->bio_driver2 = data;
290 		/*
291 		 * This copy could be eliminated by using crypto's output
292 		 * buffer, instead of using a single overwriting buffer.
293 		 */
294 		if ((bp->bio_flags & BIO_UNMAPPED) != 0)
295 			g_eli_bio_copyin(bp, data);
296 		else
297 			bcopy(bp->bio_data, data, bp->bio_length);
298 	} else {
299 		if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
300 			pages = bp->bio_ma;
301 			pages_offset = bp->bio_ma_offset;
302 		} else {
303 			data = bp->bio_data;
304 		}
305 	}
306 
307 	TAILQ_INIT(&crpq);
308 	batch = atomic_load_int(&g_eli_batch) != 0;
309 
310 	for (i = 0, dstoff = bp->bio_offset; i < nsec; i++, dstoff += secsize) {
311 		crp = crypto_getreq(wr->w_sid, M_WAITOK);
312 
313 		if (data) {
314 			crypto_use_buf(crp, data, secsize);
315 			data += secsize;
316 		} else {
317 			MPASS(pages != NULL);
318 			crypto_use_vmpage(crp, pages, secsize, pages_offset);
319 			pages_offset += secsize;
320 			pages += pages_offset >> PAGE_SHIFT;
321 			pages_offset &= PAGE_MASK;
322 		}
323 		crp->crp_opaque = (void *)bp;
324 		if (bp->bio_cmd == BIO_WRITE) {
325 			crp->crp_op = CRYPTO_OP_ENCRYPT;
326 			crp->crp_callback = g_eli_crypto_write_done;
327 		} else /* if (bp->bio_cmd == BIO_READ) */ {
328 			crp->crp_op = CRYPTO_OP_DECRYPT;
329 			crp->crp_callback = g_eli_crypto_read_done;
330 		}
331 		crp->crp_flags = CRYPTO_F_CBIFSYNC;
332 		crp->crp_payload_start = 0;
333 		crp->crp_payload_length = secsize;
334 		if ((sc->sc_flags & G_ELI_FLAG_SINGLE_KEY) == 0) {
335 			crp->crp_cipher_key = g_eli_key_hold(sc, dstoff,
336 			    secsize);
337 		}
338 		if (g_eli_ivlen(sc->sc_ealgo) != 0) {
339 			crp->crp_flags |= CRYPTO_F_IV_SEPARATE;
340 			g_eli_crypto_ivgen(sc, dstoff, crp->crp_iv,
341 			    sizeof(crp->crp_iv));
342 		}
343 
344 		if (batch) {
345 			TAILQ_INSERT_TAIL(&crpq, crp, crp_next);
346 		} else {
347 			error = crypto_dispatch(crp);
348 			KASSERT(error == 0,
349 			    ("crypto_dispatch() failed (error=%d)", error));
350 		}
351 	}
352 
353 	if (batch)
354 		crypto_dispatch_batch(&crpq, 0);
355 }
356