xref: /illumos-gate/usr/src/uts/common/fs/zfs/skein_zfs.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://opensource.org/licenses/CDDL-1.0.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2013 Saso Kiselkov.  All rights reserved.
23  * Copyright (c) 2016 by Delphix. All rights reserved.
24  */
25 #include <sys/zfs_context.h>
26 #include <sys/zio.h>
27 #include <sys/skein.h>
28 #include <sys/abd.h>
29 
30 static int
31 skein_incremental(void *buf, size_t size, void *arg)
32 {
33 	Skein_512_Ctxt_t *ctx = arg;
34 	(void) Skein_512_Update(ctx, buf, size);
35 	return (0);
36 }
37 
38 /*
39  * Computes a native 256-bit skein MAC checksum. Please note that this
40  * function requires the presence of a ctx_template that should be allocated
41  * using abd_checksum_skein_tmpl_init.
42  */
43 /*ARGSUSED*/
44 void
45 abd_checksum_skein_native(abd_t *abd, uint64_t size,
46     const void *ctx_template, zio_cksum_t *zcp)
47 {
48 	Skein_512_Ctxt_t	ctx;
49 
50 	ASSERT(ctx_template != NULL);
51 	bcopy(ctx_template, &ctx, sizeof (ctx));
52 	(void) abd_iterate_func(abd, 0, size, skein_incremental, &ctx);
53 	(void) Skein_512_Final(&ctx, (uint8_t *)zcp);
54 	bzero(&ctx, sizeof (ctx));
55 }
56 
57 /*
58  * Byteswapped version of abd_checksum_skein_native. This just invokes
59  * the native checksum function and byteswaps the resulting checksum (since
60  * skein is internally endian-insensitive).
61  */
62 void
63 abd_checksum_skein_byteswap(abd_t *abd, uint64_t size,
64     const void *ctx_template, zio_cksum_t *zcp)
65 {
66 	zio_cksum_t	tmp;
67 
68 	abd_checksum_skein_native(abd, size, ctx_template, &tmp);
69 	zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
70 	zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
71 	zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
72 	zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
73 }
74 
75 /*
76  * Allocates a skein MAC template suitable for using in skein MAC checksum
77  * computations and returns a pointer to it.
78  */
79 void *
80 abd_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
81 {
82 	Skein_512_Ctxt_t	*ctx;
83 
84 	ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
85 	(void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
86 	    salt->zcs_bytes, sizeof (salt->zcs_bytes));
87 	return (ctx);
88 }
89 
90 /*
91  * Frees a skein context template previously allocated using
92  * abd_checksum_skein_tmpl_init.
93  */
94 void
95 abd_checksum_skein_tmpl_free(void *ctx_template)
96 {
97 	Skein_512_Ctxt_t	*ctx = ctx_template;
98 
99 	bzero(ctx, sizeof (*ctx));
100 	kmem_free(ctx, sizeof (*ctx));
101 }
102