xref: /freebsd/sys/geom/eli/g_eli_privacy.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*-
2  * Copyright (c) 2005-2006 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_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_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 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 	/*
90 	 * Do we have all sectors already?
91 	 */
92 	if (bp->bio_inbed < bp->bio_children)
93 		return (0);
94 	free(bp->bio_driver2, M_ELI);
95 	bp->bio_driver2 = NULL;
96 	if (bp->bio_error != 0) {
97 		G_ELI_LOGREQ(0, bp, "Crypto READ request failed (error=%d).",
98 		    bp->bio_error);
99 		bp->bio_completed = 0;
100 	}
101 	/*
102 	 * Read is finished, send it up.
103 	 */
104 	g_io_deliver(bp, bp->bio_error);
105 	return (0);
106 }
107 
108 /*
109  * The function is called after data encryption.
110  *
111  * g_eli_start -> g_eli_crypto_run -> G_ELI_CRYPTO_WRITE_DONE -> g_io_request -> g_eli_write_done -> g_io_deliver
112  */
113 static int
114 g_eli_crypto_write_done(struct cryptop *crp)
115 {
116 	struct g_geom *gp;
117 	struct g_consumer *cp;
118 	struct bio *bp, *cbp;
119 
120 	if (crp->crp_etype == EAGAIN) {
121 		if (g_eli_crypto_rerun(crp) == 0)
122 			return (0);
123 	}
124 	bp = (struct bio *)crp->crp_opaque;
125 	bp->bio_inbed++;
126 	if (crp->crp_etype == 0) {
127 		G_ELI_DEBUG(3, "Crypto WRITE request done (%d/%d).",
128 		    bp->bio_inbed, bp->bio_children);
129 	} else {
130 		G_ELI_DEBUG(1, "Crypto WRITE request failed (%d/%d) error=%d.",
131 		    bp->bio_inbed, bp->bio_children, crp->crp_etype);
132 		if (bp->bio_error == 0)
133 			bp->bio_error = crp->crp_etype;
134 	}
135 	/*
136 	 * All sectors are already encrypted?
137 	 */
138 	if (bp->bio_inbed < bp->bio_children)
139 		return (0);
140 	bp->bio_inbed = 0;
141 	bp->bio_children = 1;
142 	cbp = bp->bio_driver1;
143 	bp->bio_driver1 = NULL;
144 	if (bp->bio_error != 0) {
145 		G_ELI_LOGREQ(0, bp, "Crypto WRITE request failed (error=%d).",
146 		    bp->bio_error);
147 		free(bp->bio_driver2, M_ELI);
148 		bp->bio_driver2 = NULL;
149 		g_destroy_bio(cbp);
150 		g_io_deliver(bp, bp->bio_error);
151 		return (0);
152 	}
153 	cbp->bio_data = bp->bio_driver2;
154 	cbp->bio_done = g_eli_write_done;
155 	gp = bp->bio_to->geom;
156 	cp = LIST_FIRST(&gp->consumer);
157 	cbp->bio_to = cp->provider;
158 	G_ELI_LOGREQ(2, cbp, "Sending request.");
159 	/*
160 	 * Send encrypted data to the provider.
161 	 */
162 	g_io_request(cbp, cp);
163 	return (0);
164 }
165 
166 /*
167  * This is the main function responsible for cryptography (ie. communication
168  * with crypto(9) subsystem).
169  */
170 void
171 g_eli_crypto_run(struct g_eli_worker *wr, struct bio *bp)
172 {
173 	struct g_eli_softc *sc;
174 	struct cryptop *crp;
175 	struct cryptodesc *crd;
176 	struct uio *uio;
177 	struct iovec *iov;
178 	u_int i, nsec, add, secsize;
179 	int err, error;
180 	size_t size;
181 	u_char *p, *data;
182 
183 	G_ELI_LOGREQ(3, bp, "%s", __func__);
184 
185 	bp->bio_pflags = wr->w_number;
186 	sc = wr->w_softc;
187 	secsize = LIST_FIRST(&sc->sc_geom->provider)->sectorsize;
188 	nsec = bp->bio_length / secsize;
189 
190 	/*
191 	 * Calculate how much memory do we need.
192 	 * We need separate crypto operation for every single sector.
193 	 * It is much faster to calculate total amount of needed memory here and
194 	 * do the allocation once instead of allocating memory in pieces (many,
195 	 * many pieces).
196 	 */
197 	size = sizeof(*crp) * nsec;
198 	size += sizeof(*crd) * nsec;
199 	size += sizeof(*uio) * nsec;
200 	size += sizeof(*iov) * nsec;
201 	/*
202 	 * If we write the data we cannot destroy current bio_data content,
203 	 * so we need to allocate more memory for encrypted data.
204 	 */
205 	if (bp->bio_cmd == BIO_WRITE)
206 		size += bp->bio_length;
207 	p = malloc(size, M_ELI, M_WAITOK);
208 
209 	bp->bio_inbed = 0;
210 	bp->bio_children = nsec;
211 	bp->bio_driver2 = p;
212 
213 	if (bp->bio_cmd == BIO_READ)
214 		data = bp->bio_data;
215 	else {
216 		data = p;
217 		p += bp->bio_length;
218 		bcopy(bp->bio_data, data, bp->bio_length);
219 	}
220 
221 	error = 0;
222 	for (i = 0, add = 0; i < nsec; i++, add += secsize) {
223 		crp = (struct cryptop *)p;	p += sizeof(*crp);
224 		crd = (struct cryptodesc *)p;	p += sizeof(*crd);
225 		uio = (struct uio *)p;		p += sizeof(*uio);
226 		iov = (struct iovec *)p;	p += sizeof(*iov);
227 
228 		iov->iov_len = secsize;
229 		iov->iov_base = data;
230 		data += secsize;
231 
232 		uio->uio_iov = iov;
233 		uio->uio_iovcnt = 1;
234 		uio->uio_segflg = UIO_SYSSPACE;
235 		uio->uio_resid = secsize;
236 
237 		crp->crp_sid = wr->w_sid;
238 		crp->crp_ilen = secsize;
239 		crp->crp_olen = secsize;
240 		crp->crp_opaque = (void *)bp;
241 		crp->crp_buf = (void *)uio;
242 		if (bp->bio_cmd == BIO_WRITE)
243 			crp->crp_callback = g_eli_crypto_write_done;
244 		else /* if (bp->bio_cmd == BIO_READ) */
245 			crp->crp_callback = g_eli_crypto_read_done;
246 		crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_CBIFSYNC | CRYPTO_F_REL;
247 		if (g_eli_batch)
248 			crp->crp_flags |= CRYPTO_F_BATCH;
249 		crp->crp_desc = crd;
250 
251 		crd->crd_skip = 0;
252 		crd->crd_len = secsize;
253 		crd->crd_flags = CRD_F_IV_EXPLICIT | CRD_F_IV_PRESENT;
254 		if (bp->bio_cmd == BIO_WRITE)
255 			crd->crd_flags |= CRD_F_ENCRYPT;
256 		crd->crd_alg = sc->sc_ealgo;
257 		crd->crd_key = sc->sc_ekey;
258 		crd->crd_klen = sc->sc_ekeylen;
259 		g_eli_crypto_ivgen(sc, bp->bio_offset + add, crd->crd_iv,
260 		    sizeof(crd->crd_iv));
261 		crd->crd_next = NULL;
262 
263 		crp->crp_etype = 0;
264 		err = crypto_dispatch(crp);
265 		if (error == 0)
266 			error = err;
267 	}
268 	if (bp->bio_error == 0)
269 		bp->bio_error = error;
270 }
271