xref: /freebsd/sys/contrib/openzfs/module/zfs/skein_zfs.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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/zio_checksum.h>
28 #include <sys/skein.h>
29 
30 #include <sys/abd.h>
31 
32 static int
33 skein_incremental(void *buf, size_t size, void *arg)
34 {
35 	Skein_512_Ctxt_t *ctx = arg;
36 	(void) Skein_512_Update(ctx, buf, size);
37 	return (0);
38 }
39 /*
40  * Computes a native 256-bit skein MAC checksum. Please note that this
41  * function requires the presence of a ctx_template that should be allocated
42  * using abd_checksum_skein_tmpl_init.
43  */
44 /*ARGSUSED*/
45 void
46 abd_checksum_skein_native(abd_t *abd, uint64_t size,
47     const void *ctx_template, zio_cksum_t *zcp)
48 {
49 	Skein_512_Ctxt_t	ctx;
50 
51 	ASSERT(ctx_template != NULL);
52 	bcopy(ctx_template, &ctx, sizeof (ctx));
53 	(void) abd_iterate_func(abd, 0, size, skein_incremental, &ctx);
54 	(void) Skein_512_Final(&ctx, (uint8_t *)zcp);
55 	bzero(&ctx, sizeof (ctx));
56 }
57 
58 /*
59  * Byteswapped version of abd_checksum_skein_native. This just invokes
60  * the native checksum function and byteswaps the resulting checksum (since
61  * skein is internally endian-insensitive).
62  */
63 void
64 abd_checksum_skein_byteswap(abd_t *abd, uint64_t size,
65     const void *ctx_template, zio_cksum_t *zcp)
66 {
67 	zio_cksum_t	tmp;
68 
69 	abd_checksum_skein_native(abd, size, ctx_template, &tmp);
70 	zcp->zc_word[0] = BSWAP_64(tmp.zc_word[0]);
71 	zcp->zc_word[1] = BSWAP_64(tmp.zc_word[1]);
72 	zcp->zc_word[2] = BSWAP_64(tmp.zc_word[2]);
73 	zcp->zc_word[3] = BSWAP_64(tmp.zc_word[3]);
74 }
75 
76 /*
77  * Allocates a skein MAC template suitable for using in skein MAC checksum
78  * computations and returns a pointer to it.
79  */
80 void *
81 abd_checksum_skein_tmpl_init(const zio_cksum_salt_t *salt)
82 {
83 	Skein_512_Ctxt_t	*ctx;
84 
85 	ctx = kmem_zalloc(sizeof (*ctx), KM_SLEEP);
86 	(void) Skein_512_InitExt(ctx, sizeof (zio_cksum_t) * 8, 0,
87 	    salt->zcs_bytes, sizeof (salt->zcs_bytes));
88 	return (ctx);
89 }
90 
91 /*
92  * Frees a skein context template previously allocated using
93  * zio_checksum_skein_tmpl_init.
94  */
95 void
96 abd_checksum_skein_tmpl_free(void *ctx_template)
97 {
98 	Skein_512_Ctxt_t	*ctx = ctx_template;
99 
100 	bzero(ctx, sizeof (*ctx));
101 	kmem_free(ctx, sizeof (*ctx));
102 }
103